Birth of Two Chimeric Genes in the Hominidae Lineage

Science  16 Feb 2001:
Vol. 291, Issue 5507, pp. 1293-1297
DOI: 10.1126/science.1057284

How genes with newly characterized functions originate remains a fundamental question. PMCHL1 and PMCHL2, two chimeric genes derived from the melanin-concentrating hormone (MCH) gene, offer an opportunity to examine such an issue in the human lineage. Detailed structural, expression, and phylogenetic analysis showed that the PMCHL1 gene was created near 25 million years ago (Ma) by a complex mechanism of exon shuffling through retrotransposition of an antisense MCH messenger RNA coupled to de novo creation of splice sites. PMCHL2 arose 5 to 10 Ma by an event of duplication involving a large chromosomal region encompassing the PMCHL1 locus. The RNA expression patterns of those chimeric genes suggest that they have been submitted to strong regulatory constraints during primate evolution.

Processes of exon shuffling, retrotransposition, and gene duplication have been suggested to lead to creation of newly found genes with specific expression characteristics and to fixation of advantageous novelties by acquisition of functional constraints (1, 2). However, because of the rapid sequence divergence characteristic of previously unknown genes, the study of the origin of a gene in detail requires the discovery of a young gene, and in particular one that has retained important features of its early stages (3, 4). Because of their recent history, two human chimeric genes, PMCHL1 andPMCHL2, open an unprecedented way to analyze the molecular mechanisms of gene remodeling and selection of functions that have operated during the late stages of primate evolution.

The PMCHL genes were named pro-MCH–like 1 and 2 genes (PMCHL1 and PMCHL2) on the basis of partial identity to the MCH gene (5). The humanMCH gene maps on chromosome 12q23 and encodes a neuropeptide precursor, whereas PMCHL1 and PMCHL2 are located onto human chromosome 5p14 and 5q13, respectively, and correspond to 5′-end truncated versions of the MCH gene (6). In previous studies, we revealed that thePMCHL genes arose recently during primate evolution by a first event of truncation/transposition from the ancestral chromosome 12 to the ancestral chromosome 5p about 25 to 30 Ma, i.e., before divergence of the Cercopithecoidae. This was followed by a second duplication event, which operated in the Hominidaelineage about 5 to 10 Ma and which distributed the two genes on each side of the chromosome 5 centromere (7). Both unspliced sense and antisense transcripts from the PMCHL1gene but not the PMCHL2 gene have been observed in different areas of the developing human brain (8, 9). A puzzling issue concerns the relation between their recent emergence and their putative function or, more precisely, whether thePMCHL genes are functional genes not previously characterized or inactive pseudogenes. This made it crucial to further study the structure, expression, and early molecular evolution of thePMCHL genes.

The focus on the molecular mechanisms responsible for the emergence ofMCH-derived sequences onto human chromosome 5 had first come from parallel studies on the regulation of MCH gene expression undertaken in our laboratory. Recently in human and rodents, we showed two classes of antisense RNAs complementary to theMCH gene (10): (i) spliced-variant mRNAs complementary in their 3′ end to the MCH gene, encoding newly found DNA/RNA binding proteins, and (ii) short noncoding unspliced RNAs that overlap only the coding part of the MCHgene (MCH exons II and III) and initiate at cap site CS3-5 (Fig. 1A). This transcriptional unit was named AROM for antisense-RNA-overlapping-MCH gene (10). Concurrently, our analysis of the structure of thePMCHL genes revealed the presence of a stretch of A at the end of the MCH-derived portion that exactly coincidates with one of the polyadenylation [poly(A)] sites found within theAROM gene, polyA(b) (Fig. 1A). This led to the conclusion that a MCH-derived sequence likely was inserted in the ancestral chromosome 5p by an event of retrotransposition of anAROM messenger RNA, incidentally strongly expressed in testis (10), as depicted in Fig. 1B.

Figure 1

(A) Extent of the homology between the MCH/AROM locus on 12q24 and the PMCHLloci on 5p14/5q13. The MCH/AROM and PMCHLexon structure given here are based on Borsu et al.(10) and Viale et al. (9), respectively. MCH- and PMCHL-derived exons are marked with roman numerals, and AROM exons are in arabic numerals. Dotted lines define the limits of the 12q24 sequence which was retrotransposed onto chromosome 5 during primate evolution. The position of the region of homology and exon-intron nomenclature are as previously described (9). Inverted black triangles correspond to AROM polyadenylation sites [poly A (a, b, or c)]. Arrows (CS1 and CS2) and the thick black line (CS3-5) represent the AROM cap sites (CS) (10). Percent homology between the MCH/AROM and PMCHLloci are also indicated. AAAA illustrates the poly(A) tail found to the end of the retrotransposed sequence: (A)11 on 5p14 and (A)14 on 5q13. GenBank accession numbers are as follows: PMCHL1, AF238382; PMCHL2, AF238383;MCH, M57703; and AROM, AF303035. (B) Proposed model for the emergence of MCH-derived sequence onto chromosome 5p. (a) An AROM mRNA initiating in the CS3-5 region and ending at poly A (b) polyadenylation site was retrotransposed onto the equivalent of chromosome 5p at the time ofCatarrhini divergence 25 to 30 Ma. (b) After this first event or concurrent to it, an Alu sequence was inserted in intron A and a fragment corresponding to the 3′ end of the retrotransposed mRNA (part of exon II-intron A-Alu) was broken and transposed to the downstream insertion site. This led to the PMCHL gene versions observed in Cercopithecoidea andHominoidea.

By combining “in silico” (through computer modeling) screening [BLAST search of GenBank against many databases in the Web site of the National Center for Biotechnology Information of the National Institutes of Health (11)] and direct sequencing of bacterial artificial chromosome (BAC) clones specific to the chromosomal regions 5p14 and 5q13 (12), the genomic structure of the PMCHL genes was further compared. According to the Web survey, several expressed sequence tags (ESTs) were found in two categories: (i) 3′ cDNA clone IMAGE ah92f11.s1 and qf54b04.x1, which are parts of PMCHL1 spliced sense transcripts and (ii) 3′ cDNA clone IMAGE qf66aO4.x1, al54h4.s1, and al47h07.s1, corresponding to parts of PMCHL2unspliced antisense transcripts and indicating that the regulation of the expression of the PMCHL genes was far more complex than previously thought (9). Structural analysis of those genes was refined by using rapid amplification of cDNA ends and polymerase chain reaction (RACE-PCR) and reverse transcriptase–PCR (RT-PCR) (13) in conjunction with the genomic analysis.

As shown in Fig. 2A, we revealedPMCHL1/PMCHL2 gene expression in human testis and established the precise 5′ and 3′ ends of the sense and antisensePMCHL1 RNA unspliced products previously described in different areas of the human brain (9). We also found in human fetal brain and in human adult testis several classes of alternative spliced mRNAs (Fig. 2B). This suggested that on both loci,MCH-derived, retrotransposed sequences recruited a group of downstream exons and introns into their transcription units thereby creating previously unknown genes with a chimeric structure. The existence of such an impressive variety of PMCHL1 andPMCHL2 transcripts resulted from the use of four polyadenylation sites (A1-A4) and a tissue-specific modulation of alternative splicing (Fig. 2B). Several cap sites were also found on the basis of RACE-PCR experiments. PMCHL2 cap sites were mainly located from 500 base pairs (bp) to more than 2 kb upstream to the insertion site, whereas PMCHL1 cap sites were found 500-bp upstream as well as 50- to 100-bp downstream to the insertion site. However, because of the complex population of mRNAs in all the tissues analyzed, it was not possible to assign a precise cap site to each class of mRNAs. Even though we cannot exclude artifactual pausing of the reverse transcriptase during synthesis of the cDNA products, this suggests that alternative splicing coupled to different starting points of transcription is probably a mechanism that allows the cell to generate a “wide repertoire” of PMCHL genes transcripts.

Figure 2

Schematic representation of the PMCHLtranscripts and potentially functional ORFs. (A) Sense and antisense unspliced mRNA products. (B) Alternatively spliced transcripts. Dotted lines delineate the chromosome 12 recruited region. The genomic organization of the transcription units is indicated in each case. The exons are boxed in gray and numbered in arabic numerals. Exon x′ illustrates alternative 3′ splice donor sites. 4′t and 4′b are tissue-specific 3′ splice donor sites; T is for testis and FB is for fetal brain. White stripes at the 5′ end of the RNAs indicate that a unique precise cap site was not assigned to these populations of mRNAs. The gene- and tissue-specificities of expression are indicated for each class of RNA: 5p and 5q are for PMCHL1 and PMCHL2transcription units, respectively. Polyadenylation sites are represented by small dark bars (A1-A4, As1, As2). Canonical polyadenylation signals AATAAA were found a few bases upstream to the sites of poly(A) addition (A1, As1 and As2). Putative polyadenylation signals ATTAAA were also found to be located 29 and 17 bases 5′ to the A2 and A3 sites of poly(A) addition, respectively, and a GATAAA signal was found 40 bases 5′ to the A4 site. Although nonconventional, ATTAAA and GATAAA have been previously noted to serve as polyadenylation signal sequences (5, 22,28). Black lines indicate the extent of the potentially functional ORFs. Upper black lines are ORFs specific of thePMCHL1 transcripts (5p locus) and down below black lines are ORFs specific of the PMCHL2 transcripts (5q locus). The translation of DNA sequences to protein sequences was conducted in the Web site of NCBI of the NIH (

The longest open reading frames (ORFs) initiated from an ATG codon in a reasonable translation initiation context (14) were deduced from the mRNA sequences obtained by RACE-PCR and RT-PCR. Two major classes of ORFs (≥33 amino acids) were found regardless of the alternative splicing pattern (bracketed in Fig. 2): (i) ORFs encoded by exon 1 and intron A (unspliced RNAs) and exon 1/exon 2/exon 2′ (spliced RNAs) exhibit a strong similarity with pro-MCH, and (ii) ORFs encoded by exons 4 to 5a and 5b display no sequence similarity with known proteins. No ORF of large length could be found for antisense RNAs. We previously demonstrated that sense unspliced PMCHL1transcripts may produce a nuclear localization signal (NLS)–containing protein deduced from ORF 1 sequence (Fig. 2A) in an in vitro translation assay and in transfected Cos cells (9). Direct proofs of the translational ability of the spliced mRNA products described here are still lacking. However, that both PMCHL1 and PMCHL2 are specifically and differentially regulated in testis and that only PMCHL1 is expressed in human fetal as well as newborn and adult brains (9) (Fig. 2) is consistent with the conclusion that those newly originated genetic elements are transcriptionally active and tightly regulated genes.

To determine whether the divergent expression patterns ofPMCHL1 and PMCHL2 could be explained by a different genomic environment in the flanking regions, we expanded our comparative analysis of the genomic structure of the PMCHLgenes. The nucleotide sequence of the PMCHL1 andPMCHL2 genomic regions over 17-kb revealed similar genomic environments with strong sequence identity (98%) between the 5p14 and 5q13 loci. To further delineate the extent of the region duplicated on both arms of chromosome 5, we performed fluorescent in situ hybridization (FISH) analysis on human metaphase chromosomes with several BAC clones bearing the PMCHL1 locus and extending more than 100-kb both 5′ and 3′ to this gene (namely 2303C18, 344I3, 283L20, and 811M22) (Fig. 3A). All those clones displayed the same hybridization patterns with strong cross-hybridization on both arms of the human chromosome 5 at bands 5p14 and 5q13 (Fig. 3B). This showed that the event of duplication that took place 5 to 10 Ma involved a large region of ancestral 5p14 encompassing several hundreds of kilobases. However, further studies are required to delineate the particular environment of cis-regulatory elements driving the striking tissue-specific expression of bothPMCHL genes.

Figure 3

(A) Genomic structural organization of the PMCHL genes. 15.4-kb of genomic sequence from both PMCHL loci was obtained by direct sequencing (both forward and reverse strands) of the 5p14-specific 283L20 and the 5q13-specific 484D2 BAC clones bearing the PMCHL1 andPMCHL2 loci, respectively (12). Dashed line represents the 1.6-kb unsequenced part of intron C. Arrows indicate BAC clone ends (not drawn to scale), and the lines represent the extent of the clones. Their localization and orientation were determined by in silico screening ( BAC clones in red were used for in situ hybridization analysis on metaphase chromosomes. All the clones described in this study come from the CIT-HSP BAC library. Blue boxes correspond to interspersed repeated sequences (same orientation thatPMCHL genes, light blue; opposite orientation, dark blue). a, LINE/L2; b, SINE/MIR-LINE/L2; c, SINE/Alu; d, LTR/THE-1B; e, SINE/Alu; f, MER91A; g, SINE/MIR; h, LINE/L1MA8; i, SINE/MIR-LINE/L1M1; j, LTR/ERVL-LINE/L1MA9; k, SINE/Alu; and l, LTR/MLT1E2. GenBank accession numbers are as follows:PMCHL1, AY08405 and PMCHL2, AY08406 (29). (B) FISH on human chromosomes with the chromosome 5p–specific BAC clone 283L20 (left) and 811M22 (right). (C) FISH of the same mouse metaphase with the chromosome 5p–specific BAC clone 811M22 (left) and a whole-chromosome painting (WCP) probe for mouse chromosome MMU15 (right). FISH was performed as previously described (15) on metaphase chromosomes from human peripheral blood lymphocytes and from mouse SV22-CD cell line. Fluorescent images were captured using a high-resolution cooled charge-coupled device (CCD) camera C4880 (Hamamatsu). Image acquisition, processing, and analysis were performed using the Vysis software package (Quips SmartCapture FISH).

As we suggested above, the source of the 5′ exons was identified as a retrotransposed sequence originated from the MCH/AROM locus. However, the origin of 3′ exons remained unclear. We examined several hypotheses concerning the origin of these non–MCH-derivedPMCHL exons: (i) these exons might be part or duplicate of an unrelated previously existing gene, supporting the concept of exon shuffling or, alternatively, (ii) these exons might originate from a unique genomic sequence that fortuitously evolved as a standard intron-exon structure and regulatory sequences for PMCHL.

To study the early molecular evolution of the PMCHLtranscription units, we first performed a FISH analysis (15) on mouse metaphase chromosomes with BAC clones surrounding the area of insertion of the MCH-derived sequences (namely 2303C18, 344I3, and 811M22) (Fig. 3A). Only the 811M22 BAC clone, bearing the 3′ PMCHL exons but not the 5′-transposed portion of the gene, displayed a clear unique hybridization signal. This signal was found onto the pericentromeric region of the mouse chromosome 15 (Fig. 3C). After comparing this result with the mapping data found in the “Mendelian Inheritance of Man gene map” and “mouse to human homology region map” databases (16), we propose that the transposed MCHsequence was inserted in a region close to the site of evolutionary rearrangement that disrupted the conserved synteny relationship with the mouse Mus musculus genome from MMU13 to MMU15. Furthermore, probes bearing the 3′ exons did not reveal cross-hybridization signal on mouse and primates [this study, (7)] and these exonic sequences did not display any similarity to any sequence of the GenBank database except the IMAGE cDNA clones previously cited. This ruled out the hypothesis that the 3′ exons might be a duplicate of an unrelated previously existing gene. However, this does not exclude that the retrotransposed sequence may have been inserted in a pre-existing gene on 5p.

To test this alternative, the phylogeny of the PMCHLintronic and exonic sequences was analyzed. We attempted to amplify the corresponding region from DNA samples from nine species of primates and from mouse by using the set of primers used to amplify intronic and exonic sequences of human genomic DNA (17). Several PCR products of the same size as those obtained from human DNA were obtained from seven primate species [Pan troglodytes (PTR),Pan paniscus (PAN), Pongo pygmaeus (PPY),Hylobates lar (HLA), Cercopithecus hamlyni (CHA),Papio papio (PAP), Cebus capucinus (CCA)]. All of the amplified products obtained from anthropoids were sequenced and compared with the human DNA sequence.

The comparative phylogenetic analysis of the PMCHLintron-exon boundaries (Fig. 4) revealed that consensus sequences at the 5′ donor splice site and in the 3′ acceptor splice site of the PMCHL1 intron A (intron Bv, Fig. 1A) were conserved in all the primates, suggesting existence of a functional constraint. Similarly, strong conservation of sequences was noted at the intron B and C boundaries. In contrast, a splice donor site in intron D was created in Cercopithecoidae (CHA) as a result of a C to T substitution at nucleotide +2. Alternative splice acceptor sites for exon 5a and exon 5b were also created by nucleotide substitution, GA to AG in Hylobatidae (HLA) and G to A at nucleotide +1 in Cercopithecoidae (PAP and CHA), respectively. Furthermore, poly(A) signals PS2 and PS3 corresponding to the poly(A) addition sites A2 and A3 (Fig. 2B) were also found to be the sites of mutations. Interestingly, a C nucleotide was found at nucleotide +3 of PS2 in CHA and PAP but not CCA, suggesting that this mutation arose specifically in the Cercopithecidae (Fig. 4). Furthermore, HLA possess the same ATTAAA sequences as the ones found in human, whereas CCA, PAP, and CHA have GA and TC at nucleotides +3 and +4 in PS3 (Fig. 4). Therefore, these results are consistent with the hypothesis that the 3′ part of the PMCHL transcription unit evolved from noncoding DNA in a common ancestor of Hominoids as a result of the creation of standard intron-exon boundaries and poly(A) signals that have been conserved in humans.

Figure 4

Phylogenetic analysis of the intron-exon boundaries and poly(A) signals of the PMCHL gene. Exonic nucleotidic sequences are in uppercase letters, and intronic nucleotidic sequences are in lowercase. The most extended consensus sequences at the 5′ splice donor site and 3′ splice acceptor site are indicated. The nearly invariant dinucleotides GT/AG at the extreme 5′ (donor) and 3′ (acceptor) ends of the introns are in bold characters. Dashes indicate identity to the human sequence. Sequence differences at the consensus sites are in gray. Sequences are arranged according to the evolutionary lineage. Intron C does not possess a canonical functional 5′ donor end; it has TT instead of GT dinucleotide. GenBank accession numbers are as follows: PAN sequences,AY008414, AY008423, and AY008426; PTR sequences, AY008416,AY008418, AY008424, AY008429, and AY008433; PPY sequences, AY008415,AY008419, AY008422, and AY008425; HLA sequences, AY008417, AY008420,AY008421, AY008427, and AY008432; CHA sequences, AY008428 andAY008430; CCA sequence, AY008431.

In CHA and PAP, which do not carry functional splice sites, we succeeded in amplifying only a small part of AROM/MCHretrotransposed sequence from the genomic DNA. In addition, a strong divergence of PMCHL1 sequence was noted in these species reflecting weak selective constraint (18). The similar exon structure of the PMCHL genes found in HSA, PAN, PTR, PPY, and HLA together with the divergence of sequence of the retrotransposedAROM/MCH sequences in the Cercopithecoidaeindicates that there was a relatively short time between the first insertion event and the subsequent mutation events leading to the recruitment of intronic and exonic components into a functional transcription unit and the speciation. As expected for emerging functions, the underlying genes were likely to undergo fast divergence until they gained stronger physiological constraints. This strongly suggests that the PMCHL gene was conserved inHominidae due to the acquisition of some constraints, probably an emerging role in primates.

Our results reveal the molecular, genetic, and evolutionary mechanisms that participated in the origin of two chimeric functional genesPMCHL1 and PMCHL2 in the Hominidaelineage (Fig. 5). Taken together, our data on the tissue-specific expression and the conserved features of thePMCHL genes suggest that their mRNA or protein have been “exapted” into a functional role [i.e., co-opted into a variant or newly characterized function (19)] in the primate lineage. The identification of the many processes in genome evolution have shown that de novo generation of building blocks—single genes or gene segments coding for protein domains—seems to be rare. Instead, genome novelty was mainly built by modification, duplication, and functional changes of the available blocks by processes of gene duplication, exon shuffling, or retrotransposition of genes (3, 20–24). In the context of human genome evolution, the previously unknown mechanism of transcript fusion of the adjacent Kua and Uev genes was recently proposed to create a chimeric Kua-Uev mRNA and the cognate fused protein (25, 26). However, in the case we described the recruited portion fused to theAROM/MCH-derived sequences was shown to have originated from a unique noncoding sequence. Moreover, the complex structure and evolutionary history ofPMCHL encompass several phenomena pointing to an important role for introns in the origin of newly characterized genes, as the exon theory of gene has suggested (27): (i) emergence of the 5′ exons by an event of duplication of a 5′-end truncated part of the MCH gene via a process of retrotransposition of an antisense MCH mRNA; (ii) creation of 3′ exons from a unique noncoding genomic sequence that fortuitously evolved as a standard intron-exon structure and polyadenylation signal sequences; (iii) alternative transcriptional initiation and splicing processes, further complicated by the presence of antisense RNAs; and (iv) a nested gene encoding unspliced mRNAs products. In the context of genome research, the existence of such gene structures poses a particular dilemna in the perspectives of prediction of exons from genome sequence data. In fact, the complex gene structure of thePMCHL loci, as described here, was not predicted from the genome sequence and exon prediction programs (GRAIL, Fex, Hexon, MZEF, Genemark, Genefinder, Fgene, Polyah).

Figure 5

Proposed model for the emergence of the chimeric PMCHL1 and PMCHL2 genes during primate evolution. A MCH-derived sequence has originated onto chromosome 5p by a complex event of retrotransposition (detailed inFig. 1B) at the time of Catarrhini divergence 25 to 30 Ma. Intron-exon boundaries and poly(A) signals were created by subsequent mutation processes before the divergence of Hylobatidae, 15 to 20 Ma, leading to the chimeric gene structure observed in theHominoidae. A last event of duplication involving a large region of ancestral 5p14 encompassing several hundreds of kb has led to the distribution of PMCHL1 andPMCHL2 on each side of the chromosome 5 centromere. This operated in the Hominidae lineage, about 5 to 10 Ma. Exons based on mRNA characterized in human are boxed in gray or white and marked with arabic numerals. The brackets indicate consensus alternative splice acceptor site for exons 4 and 5b. Polyadenylation sites are represented by small dark bars. Arabic numerals in gray indicate the location of unique noncoding sequences that gave rise to exons. Dashed lines indicates that the MCH-derived sequence was absent inPlatyrrhini.

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Coccinellidae+ Coccinellidae (/ˌkɒksɪˈnɛlɪdaɪ/) is a widespread family of small beetles ranging from 0.8 to 18 mm (0.0315 to 0.708 inches).
Coccinellinae+ The Coccinellinae are a subfamily of ladybirds in the family Coccinellidae.

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Redirect-multi|3|Ladybird|Ladybug|Lady beetle|Ladybird (disambiguation)

''Coccinella magnifica+''
Latreille+, 1807
* Chilocorinae+ Mulsant+, 1846
* Coccidulinae+ Mulsant, 1846
* Coccinellinae+ Latreille, 1807
* Epilachninae+ Mulsant, 1846
* Hyperaspidinae+ Duverger, 1989
* Microweiseinae+ Leng, 1920
* Scymninae+ Mulsant, 1846
* Sticholotidinae+ Weise, 1901

'''Coccinellidae''' () is a widespread family+ of small beetle+s ranging from 0.8 to 18 mm (0.0315 to 0.708 inches). They are commonly yellow, orange, or red with small black spots on their wing covers+, with black legs, heads and antennae+. However such colour patterns vary greatly. For example, a minority of species, such as ''Vibidia duodecimguttata+'', a twelve-spotted species, have whitish spots on a brown background. Coccinellids are found worldwide, with over 6,000 species described.

Coccinellids are known as '''ladybugs''' in North America, and '''ladybirds''' in other areas. Entomologists+ widely prefer the names '''ladybird beetles''' or '''lady beetles''' as these insects+ are not classified as true bugs+.

The majority of coccinellid species are generally considered useful insects, because many species prey on herbivorous homoptera+ns such as aphid+s or scale insect+s, which are agricultural pests. Many coccinellids lay their eggs directly in aphid and scale insect colonies in order to ensure their larvae have an immediate food source. However, some species do have unwelcome effects; among these, the most prominent are of the subfamily+ Epilachninae+, which are herbivorous themselves. Usually, epilachnines are only mild agricultural pests, eating the leaves of grain, potatoes, beans, and various other crops, but their numbers can increase explosively in years when their natural enemies, such as parasitoid+ wasps that attack their eggs, are few. In such situations, they can do major crop damage. They occur in practically all the major crop-producing regions of temperate and tropical countries.

The name ''coccinellids'' is derived from the Latin word ''coccineus'' meaning "scarlet". The name "ladybird" originated in Britain where the insects became known as "Our Lady's bird" or the Lady beetle. Mary+ (Our Lady) was often depicted wearing a red cloak in early paintings, and the spots of the seven-spot ladybird (the most common in Europe) were said to symbolise her seven joys+ and seven sorrows+. In the United States, the name was adapted to "ladybug". Common names in other European languages have the same association, for example, the German name ''Marienkäfer'' translates to Marybeetle.

Most coccinellids have oval, dome-shaped bodies with six short legs. Depending on the species, they can have spots, stripes, or no markings at all. Seven-spotted coccinellids are red or orange with three spots on each side and one in the middle; they have a black head with white patches on each side.

As well as the usual yellow and deep red colourings, many coccinellid species are mostly, or entirely, black, dark grey, gray, or brown, and may be difficult for an entomologist/nonentomologists to recognise as coccinellids at all. Conversely, non-entomologists might easily mistake many other small beetles for coccinellids. For example, the tortoise beetle+s, like the ladybird beetles, look similar because they are shaped so that they can cling to a flat surface so closely that ants and many other enemies cannot grip them.

Non-entomologists are prone to misidentify a wide variety of beetle species in other families as "ladybirds", i.e. coccinellids. Beetles are particularly prone to such misidentification if they are spotted in red, orange or yellow and black. Examples include the much larger scarabaeid+ grapevine beetles+ and spotted species of the Chrysomelidae+, Melyridae+ and others. Conversely, laymen may fail to identify unmarked species of Coccinellidae as "ladybirds". Other beetles that have a defensive hemispherical shape, like that of the Coccinellidae (for example the Cassidinae+), also are often taken for ladybirds.

A common myth, totally unfounded, is that the number of spots on the insect's back indicates its age. In fact, the underlying pattern and colouration are determined by the species and genetics of the beetle, and develop as the insect matures. In some species its appearance is fixed by the time it emerges from its pupa+, though in most it may take some days for the colour of the adult beetle to mature and stabilise. Generally, the mature colour tends to be fuller and darker than the colour of the callow+.

Coccinellids are best known as predator+s of Sternorrhyncha+ such as aphids+ and scale insects+, but the range of prey species that various Coccinellidae may attack is much wider. A genus of small black ladybirds, ''Stethorus'', presents one example of predation on non-Sternorrhyncha; they specialise in mites as prey, notably ''Tetranychus+'' spider mites. ''Stethorus'' species accordingly are important in certain examples of biological control+.Hodek, Ivo; Honek, A. ; van Emden, Helmut F. Ecology and Behaviour of the Ladybird Beetles. Publisher: Wiley-Blackwell 2012. ISBN 978-1405184229

Various larger species of Coccinellidae attack caterpillars and other beetle larvae. Several genera feed on various insects or their eggs; for example, ''Coleomegilla''+ species are significant predators of the eggs and larvae of moths such as species of Spodoptera+ and the Plutellidae+. Larvae and eggs of ladybirds+, either their own or of other species, can also be important food resources when alternative prey are scarce. As a family, the Coccinellidae used to be regarded as purely carnivorous, but they are now known to be far more omnivorous than previously thought, both as a family and in individual species; examination of gut contents of apparently specialist predators commonly yield residues of pollen and other plant materials. Besides the prey they favour, most predatory coccinellids include other items in their diets, including honeydew, pollen, plant sap, nectar, and various fungi. The significance of such nonprey items in their diets is still under investigation and discussion.Almeida, Lúcia M. ; Corrêa, Geovan H. Giorgi, José A. ; Grossi, Paschoal C. New record of predatory ladybird beetle (Coleoptera, Coccinellidae) feeding on extrafloral nectaries. Revista Brasileira de Entomologia 55(3): 447–450, setembro, 2011

Apart from the generalist aphid and scale predators and incidental substances of botanical origin, many Coccinellidae do favour or even specialise in certain prey types. This makes some of them particularly valuable as agents in biological control programmes. Determination of specialisation need not be a trivial matter, though; for example the larva of the Vedalia ladybird ''Rodolia cardinalis+'' is a specialist predator on a few species of Monophlebidae+, in particular ''Icerya purchasi+'', which is the most notorious of the cottony cushion scale species. However, the adult ''R. cardinalis'' can subsist for some months on a wider range of insects plus some nectar.

Certain species of coccinellids are thought to lay extra infertile eggs with the fertile eggs, apparently to provide a backup food source for the larvae when they hatch. The ratio of infertile to fertile eggs increases with scarcity of food at the time of egg laying. Such a strategy amounts to the production of trophic egg+s.

Some species in the subfamily Epilachninae+ are herbivore+s, and can be very destructive agricultural pest+s (e.g., the Mexican bean beetle+). Again, in the subfamily Coccinellinae, members of the tribe Halyziini and the genus ''Tythaspis'' are mycophagous+.

While predatory species are often used as biological control+ agents, introduced species of coccinellids are not necessarily benign. Species such as ''Harmonia axyridis+'' or ''Coccinella septempunctata+'' in North America outcompete and displace native coccinellids and become pests themselves.

The main predators of coccinellids are usually birds, but they are also the prey of frogs, wasps, spiders, and dragonflies. The bright colours of many coccinellids discourage some potential predators from making a meal of them. This phenomenon, called aposematism+, works because predators learn by experience to associate certain prey phenotype+s with a bad taste. A further defence, known as "reflex bleeding+", exists in which an alkaloid toxin is exuded through the joints of the exoskeleton, triggered by mechanical stimulation (such as by predator attack) in both larval and adult beetles, deterring feeding.

Coccinellids in temperate regions enter diapause+ during the winter, so they often are among the first insects to appear in the spring. Some species (e.g., ''Hippodamia convergens+'') gather into groups and move to higher elevations, such as a mountain, to enter diapause.

Predatory coccinellids are usually found on plants which harbour their prey. They lay their eggs near their prey, to increase the likelihood the larvae will find the prey easily. In ''Harmonia axyridis'', eggs hatch in three to four days from clutches numbering from a few to several dozen. Depending on resource availability, the larvae pass through four instar+s over 10–14 days, after which pupa+tion occurs. After a teneral+ period of several days, the adults become reproductively active and are able to reproduce again, although they may become reproductively quiescent if eclosing+ late in the season. Total life span is one to two years on average.

In the United States, coccinellids usually begin to appear indoors in the autumn when they leave their summer feeding sites in fields, forests, and yards and search out places to spend the winter. Typically, when temperatures warm to the mid-60s F (around 18 °C) in the late afternoon, following a period of cooler weather, they will swarm onto or into buildings illuminated by the sun. Swarms of coccinellids fly to buildings in September through November depending on location and weather conditions. Homes or other buildings near fields or woods are particularly prone to infestation.

After an abnormally long period of hot, dry weather in the summer of 1976 in the UK+, a marked increase in the aphid population was followed by a "plague" of ladybirds, with many reports of people being bitten as the supply of aphids dwindled.

The presence of coccinellids in grape harvests can cause ladybird taint+ in wines produced from the grapes.

''Harmonia axyridis+'' (the harlequin ladybird) is an example of how an animal might be partly welcome and partly harmful. It was introduced into North America from Asia in 1916 to control aphids, but is now the most common species, outcompeting many of the native species. It has since spread to much of western Europe, reaching the UK in 2004. It has become something of a domestic and agricultural pest in some regions, and gives cause for ecological concern. It similarly has turned up in parts of Africa, where it has proved variously unwelcome, perhaps most prominently in vine-related crops.

The atlas ''Ladybirds (Coccinellidae) of Britain and Ireland'' published in 2011 showed a decline of more than 20% in native species due to environmental changes and competition from foreign invaders. The distribution maps, compiled over a 20-year period with help from thousands of volunteers, showed a decline in the numbers of the common 10-spot and 14-spot ladybirds and a number of other species, including the 11-spot, 22-spot, cream-spot, water and hieroglyphic ladybirds, ''Coccidula rufa, Rhyzobius litura'' and ''Nephus redtenbacheri''. Conversely, increases were seen in the numbers of harlequin, orange, pine, and 24-spot ladybirds, as well as ''Rhyzobius chrysomeloides''. The kidney spot ladybird was recorded in Scotland for the first time in recent years, and the 13-spot was found to have recolonised Cornwall+, Devon+, and the New Forest+. The most commonly recorded species was the 7-spot, closely followed by the Asian harlequin — an invader that arrived from continental Europe in 2003 after being introduced to control pests. An 'explosion' in the number of orange ladybirds, which feed on mildew, is thought to have been due to the warmer, damper conditions that now prevail in parts of England.

File:Ladybug among ants - 2013-4-18 - Alberta Canada.webm|HD video of a ladybird near an anthill

File:Scymnus sp - 2012-10-16.webm|thumbtime=0:39|A brownish ''Scymnus'' sp. (tribe Scymnini)

Coccinellids are, and have been for very many years, an insect of interest and favour for children. The insects had many regional names (now mostly disused) in English, such as variations on Bishop-Barnaby (Norfolk+ and Suffolk dialect+) – Barnabee, Burnabee, the Bishop-that-burneth, and bishy bishy barnabee. The etymology is unclear, but it may be from St. Barnabas' feast in June, when the insect appears, or a corruption of "Bishop-that-burneth", from the fiery elytra+ of the beetles.

The ladybird was immortalised in the popular children's nursery rhyme+ ''Ladybird, Ladybird+'':

Ladybird, ladybird, fly away home

Your house is on fire and your children are gone

All except one, and that's Little Anne

For she has crept under the warming pan+.

This poem has its counterpart in German as ''Marienwürmchen,'' collected in ''Des Knaben Wunderhorn+'', and set to music by Robert Schumann+ as Op. 79, No. 13.

There is also a Polish+ nursery rhyme+, "Little Ladybirds' Anthem", of which a part ("fly to the sky, little ladybird, bring me a piece of bread") became a saying:

Mała Biedroneczka siedem kropek miała,

Na zielonej łące wesoło fruwała.

Złapał ją pajączek w swoją pajęczynę

- uratuję Cię Biedronko, a ty mi coś przynieś.

Biedroneczko leć do nieba, przynieś mi kawałek chleba.

Little ladybird had seven dots,

She was flying over a green meadow.

A little spider caught her in its spiderweb

Fly to the sky, little ladybird, bring me a piece of bread.

Many cultures consider coccinellids lucky and have nursery rhymes or local names for the insects that reflect this. For instance, the Turkish name for the insect is ''uğur böceği'', literally meaning "good luck bug". In many countries, including Russia, Turkey, and Italy, the sight of a coccinellid is either a call to make a wish or a sign that a wish will soon be granted.

In Christian areas, coccinellids are often associated with the Virgin Mary+ and the name that the insect bears in the various languages of Europe+ corresponds to this. Though historically many European languages referenced Freyja+, the fertility+ goddess+ of Norse mythology+, in the names, the Virgin Mary has now largely supplanted her, so that, for example, ''freyjuhœna'' (Old Norse+) and ''Frouehenge'' have been changed into ''marihøne'' (Norwegian+) and ''Marienkäfer'' (German+), which corresponds with Our Lady+'s bird. Sometimes, the insect is referred to as belonging directly to God (Irish+ ''bóín Dé'', Polish+ ''boża krówka'', all meaning "God's [little] cow"). In Dutch+ it is called ''lieveheersbeestje'', meaning "little animal of our Good Lord".

In both Hebrew+ and Yiddish+, it is called "Moshe Rabbenu+'s (i.e. Moses's) little cow" or "little horse", apparently an adaptation from Slavic languages. Occasionally, it is called "little Messiah+".''Born to Kvetch'', Michael Wex+, St. Martin's Press, New York, 2005, ISBN 0-312-30741-1.

The bold colours and simple shapes have led to use as a logo+ for a wide range of organisations and companies, including:
* Ladybird Books+ (owned by Pearson PLC+)
* Ladybird range of children's clothing sold by former and Woolworth's+ chain store in the UK
* Polish supermarket chain Biedronka+
* Atmel AVR+ Studio software logo
* Software development firm Axosoft+
* Symbol of the Swedish People's Party of Finland+
* Symbol of the Pestalozzi International Village+ charity
* Symbol of the Croatian Lottery+
* The ladybird street tile (pictured) is a symbol against senseless violence+ in the Netherlands, and is often placed on the sites of deadly crimes.

In addition, it has been chosen as:
* US state insect+ of Delaware+, Massachusetts+, New Hampshire+, New York+, Ohio+, and Tennessee+, though only New York has selected a species native to the United States+ (''Coccinella novemnotata+''); the other states have all adopted an invasive European species (''Coccinella septempunctata+'').
* An "official national mascot" for Alpha Sigma Alpha+, a national sorority+ in the United States
* An "official national mascot" for Swing Phi Swing Social Fellowship Inc.+®, a national non-profit sisterhood in the United States
* The mascot of Candanchú+, a ski resort situated near the town of Canfranc+ in the High Aragon+ of the western Pyrenees+ (Province of Huesca+, Spain)

* Ongoing North American Ladybeetle Survey and Citizen Science Project based at Cornell University - Submit Photos
* Cornell University's ''Guide to natural enemies in North America''
* In: Hodek I., Honěk A., van Emden H.F. (2012) Ecology and Behaviour of the Ladybird Beetles (Coccinellidae). John Wiley and Sons Ltd. pp. 526–531.
* on the UF / IFAS+ Featured Creatures website.
* on the UF / IFAS+ Featured Creatures website.

Authority control:


Krammer 1997      Category: Asymmetrical biraphid
TYPE SPECIES: Encyonopsis cesatii Krammer

Image Credit: Loren Bahls

CLASS: Bacillariophyceae
  ORDER: Cymbellales
    FAMILY: Cymbellaceae

  1. Valves naviculoid, slight apical asymmetry
  2. Areolae round or transapically elongate
  3. Striae radiate or parallel at the apices
  4. Proximal raphe ends deflected dorsally
  5. Distal raphe fissures deflected ventrally

Valves are naviculoid and slightly dorsiventral, symmetric to the transapical axis and asymmetric to the apical axis. The raphe is centrally located. Areolae in the striae are round or oblong and oriented with their long axes parallel to the transapical axis. Transapical striae are radiate near the valve center and radiate or parallel near the apices. Proximal raphe ends are deflected toward the dorsal margin. Distal raphe fissures are deflected ventrally. Stigmata and apical pore fields are absent.

Encyonopsis is distinguished from Kurtkrammeria by the orientation of the striae at the valve apices, by the shape and orientation of the areolae, and by other features observed in SEM. In Encyonopsis species, areolae are round or elongate in a transapical direction. In Kurtkrammeria, areolae are slit-like or crescent shaped with the long axis oriented apically. In Encyonopsis, the terminal striae are radiate or parallel; in Kurtkrammeria, terminal striae are convergent. Stigmata and apical pore fields may be present in Kurtkrammeria, but they are absent in Encyonopsis.

Cite This Page:
Bahls, L. (2015). Encyonopsis. In Diatoms of the United States. Retrieved August 26, 2016, from http://westerndiatoms.colorado.edu/taxa/genus/Encyonopsis

Contributor: Loren Bahls - December 2015
Reviewer: Sarah Spaulding - December 2015

November 8th, 2015 - Change in circumscription

The concept of the genus Encyonopsis was changed to become more narrow as of this date. The genus Kurtkrammeria was recognized and established as a new genus. Formerly, Encyonopsis included the broader definition.


What is Glossitis?: Types, Causes and Symptoms

Everything You Need to Know About Glossitis

What Is Glossitis?

Glossitis refers to inflammation of the tongue. The condition causes the tongue to swell in size, change in color, and develop a smooth appearance on the surface. The tongue is the small, muscular organ in the mouth that helps you chew and swallow food. It also helps with your speech.

Glossitis can cause the small bumps on the surface of the tongue called the papillae to disappear. Your papillae play a role in how you eat. They contain thousands of tiny sensors called taste buds.

Severe tongue inflammations that result in swelling and redness can cause pain and change the way you eat or speak.

The Types of Glossitis

 Type 1

There are several different types of glossitis:

Acute Glossitis

Acute glossitis is an inflammation of the tongue that appears suddenly, and it often has severe symptoms. This type of glossitis typically develops during an allergic reaction.

Chronic Glossitis

Chronic glossitis is an inflammation of the tongue that continues to recur. This type may begin as a symptom of another health condition.

Idiopathic Glossitis

Idiopathic glossitis, also known as Hunter’s glossitis, affects the muscles of the tongue. In this condition, a significant amount of papillae can be lost. The cause of idiopathic glossitis is unknown.

Atrophic Glossitis

Atrophic glossitis occurs when a large number of papillae are lost, resulting in changes to the tongue’s color and texture. This type of glossitis typically turns the tongue dark red.

What Causes Glossitis?

A number of factors can cause inflammation of the tongue, including:

Allergic Reactions

Allergic reactions to medications, food, and other potential irritants may aggravate the papillae and the muscle tissues of the tongue. Potential irritants include toothpaste and certain types of medications that treat high blood pressure.

Certain diseases that affect your immune system may attack the tongue’s muscles and papillae. Herpes simplex, a virus that causes cold sores and blisters around the mouth, may contribute to swelling and pain in the tongue.

Low Iron Levels

An inadequate amount of iron in the blood can trigger glossitis. Iron regulates cell growth by helping your body make red blood cells. Red blood cells carry oxygen to your organs, tissues, and muscles. Low levels of iron in the blood may result in low levels of myoglobin. Myoglobin is a protein in red blood cells that’s important for muscle health, including the tongue’s muscle tissue.

Dry Mouth

Dry mouth is caused by a lack of saliva, which may be due to a salivary gland disorder or overall dehydration. You need saliva to keep your tongue moist.

Mouth Trauma

Trauma caused by injuries to the mouth can affect the condition of your tongue. Inflammation may occur as a result of cuts and burns on the tongue or of dental appliances placed on your teeth, such as braces.

Who Is at Risk for Glossitis?

Risk Factors

You may be at risk for tongue inflammation if you:

  • have a mouth injury
  • eat spicy foods
  • wear braces or dentures that irritate your tongue
  • have herpes
  • have low iron levels
  • have dry mouth
  • have food allergies
  • have an immune system disorder

What Are the Symptoms of Glossitis?

Your symptoms may vary depending on the cause of the inflammation. In general, however, you can experience the following symptoms:

  • pain or tenderness in the tongue
  • swelling of the tongue
  • change in the color of your tongue
  • an inability to speak, eat, or swallow
  • loss of papillae on the surface of your tongue

How Is Glossitis Diagnosed?

You may see your dentist or doctor for an assessment of your condition. They’ll examine your mouth to check for abnormal bumps and blisters on your tongue, gums, and soft tissues of your mouth. Samples of your saliva and blood may also be taken and sent to a laboratory for further examination.

How Is Glossitis Treated?

Treatment for glossitis typically includes a combination of medications and home remedies.

Antibiotics and other medications that get rid of infections may be prescribed if bacteria are present in your mouth or body. Your doctor may also prescribe corticosteroids, such as prednisone, to reduce the redness and soreness.

Home Care

Brushing and flossing your teeth several times a day may improve the health of your tongue, gums, and teeth. This can help relieve the symptoms associated with glossitis and prevent the condition from happening again.

What Can Be Expected in the Long Term?

In most cases, glossitis goes away with medication. Treatment may be more successful if you avoid foods that cause inflammation of the tongue. Practicing proper oral hygiene may also help reduce or prevent further problems. Speak with your doctor if your symptoms don’t improve with treatment or continue to occur.

Call 911 or go to the hospital right away if your tongue becomes severely swollen and begins to block your airway. This may be a sign of a more serious condition.

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What is 'Strong Form Efficiency'

Strong form efficiency is the strongest version of market efficiency and states that all information in a market, whether public or private, is accounted for in a stock's price. Practitioners of strong form efficiency believe that not even insider information can give an investor an advantage. This degree of market efficiency implies that profits exceeding normal returns cannot be made, regardless of the amount of research or information investors have access to.

BREAKING DOWN 'Strong Form Efficiency'

Strong form efficiency is a component of the efficient market hypothesis and is considered part of the random walk theory. Strong form efficiency states that securities prices, and therefore the overall market, are not random and are influenced by past events. This efficiency is at the opposite end of weak form efficiency, which states that past events have no effect on current securities prices and price movements.

The idea behind strong form efficiency was pioneered by Princeton economics professor Burton G. Malkiel in his 1973 book "A Random Walk Down Wall Street." The book championed two forms of the random walk theory. The form that explains strong form efficiency states that it is impossible to consistently outperform the market due to the fact that all information, both public and proprietary, is reflected in current market prices, and it is therefore impossible to earn long-term abnormal returns.

Example of Strong Form Efficiency

Most examples of strong form efficiency include some sort of insider information. This is because strong form efficiency is the only part of the efficient market hypothesis that takes into account proprietary information. However, the efficiency theory states that contrary to popular belief, harboring some sort of inside information won't help an investor earn high returns in the market.

Let's say, for example, that the CTO of a public technology company believes that his company will begin to lose customers and revenues. After the internal rollout of a new product feature to beta testers, the CTO's fears are confirmed and he knows that the official rollout will be a flop. This would be considered insider information.

The CTO decides to take up a short position on his own company, effectively betting against the stock price movement. If the stock price declines, he is poised to profit, and vice versa. However, much to the CTO's chagrin, when the product feature is released to the public, the stock price is unaffected and does not decline, even though customers are not happy. The market would be considered to be strong form efficient because even the insider information of the product flop was already priced into the stock. The CTO would lose money in this situation.

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  4. Efficiency

    A level of performance that describes a process that uses the ...
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  6. Allocational Efficiency

    A characteristic of an efficient market in which capital is allocated ...
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Publicat 10 Feb 2014 | Reactualizat 10 Mar 2014 | Expiră 14 Mar 2014

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Candidatul ideal

As Piping Designer you have fairly broad and challenging tasks. You are responsible for making all possible detail- and plant drawings. You are able to independently create isometrics from P&ID’s and take care of Material Take-Off (MTO). You are able to handle a large workload and able to achieve a high rate of production (“bulk work of ISO production). Of course you are also able to check and evaluate the information from other disciplines within the organization, and also from clients or suppliers. You will supervise junior designers and drafters if necessary. You are able to take on site measurements and sketches.

Descrierea jobului

Description of Tasks

- Conduct necessary fieldwork inclusive of walk downs of current systems, locate tie-ins and measuring;
- Prepare piping design sketches as required by drafting personnel;
- Check piping drawings developed by drafting personnel;
- Ensure performance of staff members is in compliance with established project standards;
- Complete isometric drawings and piping layout as needed;
- Ensure to complete pipe component and run detailed drawings as necessary;
- Review project parameters related to piping requirements;
- Develop preliminary Bills of Materials with respect to piping design;
- Administer technically to outsource function as required;
- Interpret and administer various Pipe Material and options;
- Provide assistance to sales and contracts for proposals.

Job Requirements

- You need at least a degree in Mechanical Engineering on the Secondary Vocational level (in The Netherlands: MBO level degree), supplemented by a minimum of 5 to 10 years relevant work experience as Designer within a professional engineering environment;
- You have knowledge of the international codes , standards and regulations and discipline related software;
- You have extensive experience within the oil, gas, (petro)chemical and/or tank terminal industries, mostly with onshore projects;
- Extensive experience with AutoCAD 2D is a demand;
- Experience with Bentley Autoplant 3D is a preference;
- Personal characteristics you stand for are: quality, customer orientation, flexibility, discipline, teamwork and stress resistance;
- You are able to communicate in and handle the English language fluently in writing, reading and speaking;
- You are in the possession of a valid “Basic Elements of Safety” (VCA Basic) certificate or “Elements of safety for Operational Supervisors” (VCA VOL) certificate, or are willing to get this certificate on short notice after taking an exam in English.

Employer Location

- Netherlands

• Datele de identificare ale tuturor companiilor care publica anunturi de recrutare pe sunt verificate de consultantii nostri. nu influenteaza, insa, procesul de recrutare desfasurat de catre companii.

• Analizati cu atentie informatiile din cadrul anunturilor de recrutare! Daca aveti dubii in privinta veridicitatii anumitor date sau in cazul unor solicitari suplimentare ale angajatorilor (trimiterea de documente personale, sume de bani etc.), va rugam sa ne scrieti la


Species Composition

Species Composition

Species composition refers to the contribution of each plant species to the vegetation. Botanical composition is another term used to describe species composition. Species composition is generally expressed as a percent, so that all species components add up to 100%.

Species composition can be expressed on either an individual species basis, or by species groups that are defined according to the objectives of the inventory or monitoring program (eg., Aristida spp., perennial forage grasses, etc.).

Species composition is a commonly determined attribute in rangeland inventory and monitoring. It is regarded as an important indicator of ecological and management processes at a site.

Ecological indicators - species composition provides the essential description of the character of the vegetation at a site. Certain images are readily understood when major species are mentioned, eg., pinon (Pinus sp.) - juniper (Juniperus sp.) woodland, and other common species are also presumed to be present as one becomes familiar with the vegetation. These distinctions form the basis of rangeland mapping and the delineation of range site boundaries.

The relative contribution of a species also signifies its dominance in the vegetation and its ability to capture resources. Slightly different inferences of competitive ability are suggested if species composition is expressed on the basis of cover, density, or biomass measurements.

Management indicators - most objectives in rangeland management are directly concerned with the assessment or manipulation of species composition. For example, carrying capacity is influenced by the relative abundance of desirable forage species at a site. Wildlife habitat is also influenced by the relative contribution of various species that provide sources of shelter and food. Species composition is used to determine range condition and range trend, which are valuable tools to judge the impact of previous management and guide future decisions.

Special Considerations for Species Composition Sampling

Here is a critical issue to be considered when designing sampling protocols to determine species composition:

Methods to Determine Species Composition

Species composition is generally determined by sampling methods based on assessing the contribution of individual species or species groups in sample units. This section describes methods commonly used to determine species composition.

References and Further Reading

Barbour, M.G., Burk, J.H., and W.D. Pitts. 1987. Terrestrial plant ecology. Benjamin Cummins Publishing Co, Menlo Park, CA. 2nd ed. pp. 191-193.

Bureau of Land Management. 1996. Sampling Vegetation Attributes. Interagency Technical Reference, BLM/RS/ST-96/002+1730. pp. 28-29.

Society for Range Management. 1989. A Glossary of Terms Used in Range Management. Society for Range Management, Denver, CO. 3rd ed. p.13.


Buzz: Back from the ER, a wounded Ariad spurs a fresh round of takeover rumors

Market rumors about a possible biotech buyout are usually triggered by research and marketing success. In Ariad's case, mere survival sufficed.

The Mail in the U.K.--never known as the most reliable source of market information--reports that a pair of sizable local players, GlaxoSmithKline ($GSK) and Shire ($SHPG), has been fishing for a possible deal. But it's Eli Lilly ($LLY) that appears to be the lead potential bidder, according to the market rumors, which regardless of their source pushed up the stock price ($ARIA) by 10% this morning.

The Mail somehow manages to overlook Ariad's near-death experience in recent months, with questions about safety issues surrounding their drug Iclusig (ponatinib) boiling up into a crisis and forcing the withdrawal of the leukemia drug in the U.S. The stock price slumped, the company restructured, laying off a big chunk of its workforce. And then the FDA relented, allowing a revised label that tailored the population to patients to a genetically defined group who didn't respond to anything else that's available.

Ariad shares jumped a bit on the new label, though they remain far, far below the pre-October crisis highs. Its market cap sits at about $1.25 billion. That price makes the company easily obtainable, but if the rumors are even remotely true, why would Lilly--or Shire or GSK--buy it?

Lilly in particular has experienced a series of challenges on the oncology side of its R&D efforts. It has two high-profile cancer drugs in the late-stage pipeline, ramucirumab and necitumumab. Ramucirumab looks promising for stomach cancer, but flunked out for the more lucrative breast cancer indication. And while necitumumab scored a win for lung cancer, researchers have also been plagued by concerns over blood clots, the same issue that threatens to scuttle Iclusig.

Would another troubled cancer product offer significant help for a pharma giant headed into a trough year after losing control of its big franchises for Zyprexa and Cymbalta? Eli Lilly badly needs new products to flesh out a dwindling portfolio. But it hasn't done many deals, insisting that the internal pipeline could provide all the new products it needs for a turnaround.

Lilly's last significant buyout was for Amyvid, an imaging agent without a market after Medicare refused to cover its use. Any deal for Ariad would have to be very advantageous if Lilly wants to avoid a fresh round of scoffing.

- here's the story from The Mail


Second Language Studies | Topics Second Language Studies
S600 | 26854 | Dekydtspotter, L

Topic:  Problems of Learning.  This course investigates a basic
problem of knowledge: To what extent do second language learners
acquire knowledge of structures that are not licensed by their native
grammar? Generally, we will focus on the gap between the information
provided by the input and the state of knowledge that the learner
develops (both cases where knowledge seems to far
exceed the information provided by input and cases where acquisition
seems plodding). We will investigate the following notions: the
poverty of the stimulus problem, the underdetermination problem, the
projection problem, and related paradoxes. We will consider a typology
of poverty of the stimulus argumentation in L2 acquisition and the
centrality of a learnability discussion in L2 work. We will examine
types of explanations that various schools of thought have provided or
suggested about the relationship between
input and learner?s internal systems. Students will be developing
their own research around a central learning problem under the
guidance of the instructor.


McCain For President?

Obama For President?

Does Gerrymandering Cause Polarization?

Joe Lieberman in Polarized America

Corrections to the Hard Cover Edition of Polarized America

Polarized America: The Dance of Ideology and Unequal Riches

(June 2006, MIT Press)

Nolan McCarty, Keith T. Poole, and Howard Rosenthal

Political polarization, income inequality, and immigration have all increased dramatically in the United States over the past three decades. The increases have followed an equally dramatic decline in these three social indicators over the first seven decades of the twentieth century. The pattern in the social indicators has been matched by a pattern in public policies with regard to taxation of high incomes and estates and with regard to minimum wage policy. We seek to identify the forces that have led to this observation of a social turn about in American society, with a primary focus on political polarization.

Our primary evidence of political polarization comes from analysis of the voting patterns of members of the U.S. House of Representatives and Senate. Based on estimates of legislator ideal points (Poole and Rosenthal 1997 and McCarty, Poole, and Rosenthal 1997), we find that the average positions of Democratic and Republican legislators have diverged markedly since the mid-1970s. This increased polarization took place following a fifty-year blurring of partisan divisions. This turning point occurs almost exactly the same time that income inequality begins to grow after a long decline and the full effects of immigration policy liberalization are beginning to be felt.

Some direct causes of polarization can be ruled out rather quickly. The consequences of one person, one vote decisions and redistricting can be ruled out since the Senate, as well as the House of Representatives, has polarized. The shift to a Republican South can be ruled out since the North has also polarized. Primary elections can be ruled out since polarization actually decreased once primaries became widespread.

In additional to our focus on the polarization of elected office-holders, we look at patterns of polarization among economic elites. By examining campaign contributions, we find very high levels of polarized giving. While some billionaires clearly spread their contributions to both parties to buy access, increasing numbers concentrate their largess on the ideological extremes. This polarized campaign giving, coupled with the emergence of the soft money loophole has arguably contributed to the ideological extremism of political parties and elected officials.

Finally, we also examine polarization among the electorate. While it is fairly clear that the views of most citizens have not become more extreme, those with strong partisan identifications have (DiMaggio, et al., Fiorina). Consistent with other findings (King, Jacobson), we find that partisans are more likely to apply ideological labels to themselves and a declining number of them call themselves moderate. Strong party identifiers are the most likely to define politics and ideological terms while the differences in the ideological self-placements of Republicans and Democrats have grown dramatically since the 1980s. Given Bartels findings that partisanship has become a better predict of vote choice, this polarization of partisans has contributed to much more ideological voting behavior.

We also find that the polarization of the electorate has increasingly taken place along economic or class lines. Unlike the patterns of the 1950s and 1960s, upper income citizens are more likely to identify with and vote for Republicans than are lower income voters. However, we find that class polarization is most likely a result of the ideological shift of the Republican Party towards a more economic libertarian position. This shift to the right was aided by a number of social, political, and economic factors. First, as American society has become wealthier on average, a larger segment of society prefers to self-insure rather than depend on government social programs. Such voters have become more attracted to the Republicans and their agenda for an Ownership Society. Second, due to patterns of immigration and incarceration, members of lower income groups are less likely to be part of the electorate. This has the effect of moving the median income voter closer to the mean income citizen, reducing the demand for redistribution (Romer, Meltzer and Richard). Third, middle-income voters in the so-called Red states increasingly sympathize with Republican positions on social, cultural, and religious issues (e.g. Franks). The Republican advantage on these issues has mitigated any loss of votes that might have been associated with their shift on economic issues. Finally, the emergence of a class-based, two-party system in the United States has benefited the Republicans and mirrored the patterns of economic polarization found in other regions.

Finally, we examine the policy consequences of the fall and rise of political polarization. The separation of powers makes it difficult to generate coalitions large enough to produce policy change even when opinion shifts. We exploit this observation to get some leverage in disentangling the effects of political, economic, and social policies. For much of the period when polarization fell, immigration policy was restrictive and unchanged while income and estate taxes, defined in nominal terms, became more onerous. For the period since the onset of renewed polarization, we find strong evidence that gridlock has resulted in a less activist federal government. The passage of new laws has been curtailed due to the increasing difficulty of generating the requisite bipartisan coalitions. The effects on social and tax policy have been especially dramatic as real minimum wages have fallen, welfare devolved to the states, and tax rates have diminished. We also show how polarized politics has affected administrative and judicial politics.

(Of related interest! Note the Patterns. Added, July 2011)

For further information about McCarty, Poole, and Rosenthal's work on Polarization see:

The Next Big Issue: Inequality in America, by Godfrey Hodgson

Interview of Nolan McCarty by The American Prospect

The Decline and Rise of Party Polarization in Congress During the 20th Century

Growing Apart: The Mathematical Evidence for Congress' Growing Polarization, by Jordan Ellenberg
(Note that the links to voteview.uh.edu should be pooleandrosenthal.com. The pages are still on the website.)

Party Polarization: 1879 - 2015


John Buridan on Self-Reference: Chapter Eight of Buridan's Sophismata, with a translation, an introduction and a philosophical commentary by G.E. Hughes (New York: Cambridge University Press, 1982), xi + 233 pp.

Alfred J. Freddoso
University of Notre Dame

This is an excellent book, a paradigm of its genre. In Chapter Eight of the Sophismata Buridan proposes his highly sophisticated solutions to a wide variety of alethic (Liar-type), epistemic and pragmatic paradoxes involving self-reference. Hughes' almost equally impressive contribution consists of no less than (i) a clear and penetrating introduction (pp. 1-37), (ii) a new (albeit non-critical) edition of the Latin text along with a facing English translation that is unfailingly accurate and smooth (pp. 38-129), (iii) notes to the Latin text (pp. 131-139), and (iv) a painstaking and philosophically illuminating commentary (pp. 141-227). The work as a whole has been fashioned with great care and obviously represents a labor of love as well as of scholarship on Hughes' part. (For confirmation of this last point, consult the final note on p. 139.)

The epistemic paradoxes are probably the deepest, while the pragmatic paradoxes are undoubtedly the most entertaining. Here, however, I will confine my brief remarks to Buridan's distinctive resolution of the alethic paradoxes. Since the issues raised by these paradoxes are, in Hughes' words, "profound, complicated and ramified," I can do little more in a short review than scratch the surface. Accordingly, I will be content to describe Buridan's strategy in rough outline and then to focus on a limited, though significant, problem which both Buridan and Hughes have, I think, neglected to face up to. (Unless the context indicates otherwise, I will be using the term 'proposition' in the way that Buridan uses the Latin 'propositio', viz., to refer to contingently existing sentence-tokens.1)

Almost all the gifted 20th century philosophers who have thought deeply about problematic propositions (sophisms) such as

    (A) (A) is false
    (B) (C) is false

    (C) (B) is true

/78/ have held that they are neither true nor false. That is to say, these philosophers have accepted the prima facie compelling claim that such sophisms are true or false only if they are both true and false. Buridan demurs. (A), (B), (C) and their ilk are, he contends, one and all false and not true.2

To buttress this contention, he must refute the seemingly powerful arguments for the claim that if the sophisms in question are false, then they are true as well. I will look at two such arguments, each centering about (A).

Consider, first, the following chain of reasoning purporting to take us from (A)'s falsity to its truth:

    (1) (A) is false. (assumption)
    (2) If (A) is false, then there is something for which (A)'s subject-term ('(A)') and its predicate-term ('false') both supposit (or, on a Fregean account: then the thing denoted by (A)'s subject-term satisfies the concept expressed by its predicate-term).3 (premise)
    (3) So there is something for which (A)'s subject-term and predicate-term both supposit. (1,2)
    (4) But a (singular) proposition is true if and only if there is something for which its subject-term and predicate-term both supposit. (premise)
    (5) So (A) is true. (3,4)

Buridan retorts that, contrary to appearances as well as to the common opinion of philosophers, (4) is false. The reason is that its right-hand side (or the Fregean equivalent thereof) embodies only a necessary and not a sufficient condition for the truth of a singular proposition.

This claim, needless to say, cries out for elaboration and defense. Let 'N is P' be a schema representing singular propositions, with 'N' and 'P' serving to represent the subject- and predicate-terms, respectively. To oversimplify just a bit, on Buridan's showing a complete account of the semantic truth conditions of singular propositions will look like this:

    (T) 'N is P' is true if and only if

      (i) there is something for which both 'N' and 'P' supposit in the proposition 'N is P'; and
      (ii) '"N is P" is true' is true.

('"N is P" is true' constitutes what Hughes calls the 'implied proposition'.4)

Ordinarily, conditions (i) and (ii) are both satisfied if either is. For instance, given that the propositions 'Socrates is sitting' and '"Socrates is sitting" is true' both exist, the former is true if and only if the latter is also true. That is why it is so easy for us to slip into thinking that condition (i) is sufficient by itself. According to Buridan, however, it is precisely in the case of certain self-referential propositions (e.g., (A)) /79/ that condition (i) is satisfied without condition (ii) also being satisfied. For even though there is something, viz. (A) itself, for which '(A)' and 'false' both supposit, the implied proposition, viz. '"(A) is false" is true', is nonetheless false--as is shown, Buridan asserts, by the standard arguments for (A)'s falsity. (Hughes presents two such arguments on p. 24.)

Now this appeal to the standard arguments for (A)'s falsity has all the appearances of being question-begging. After all, the champion of the argument expressed by (1)-(5) will reject the standard arguments for (A)'s falsity precisely because he has what he takes to be a sound argument showing that (A) is false only if it is also true. That is, the argument captured by (1)-(5) is meant to be at least an indirect response to the standard arguments for (A)'s falsity. So Buridan's invocation of the latter to undermine the former seems clearly to be dialectically improper. Hughes, however, is evidently not sensitive to this particular criticism of Buridan. (See pp. 24-25 for the relevant discussion.)

The very same criticism applies to Buridan's treatment of the second argument from (A)'s falsity to its truth. This argument is found in the Eleventh Sophism (see p. 89) and is almost identical to the argument which Hughes considers on pp. 25-27. To understand this argument we must have a decent grasp of what Hughes calls the 'principle of truth-entailment'. I will try to state it as clearly and accurately as I can. Let S be a schematic letter which takes propositions as substitutions, and let [S] represent a proper name of the proposition substituted for S. Then, according to Buridan, the following is true for any such substitution:

    (PTE) Necessarily, if S and [the proposition] [S] exists, then [the proposition] [S] is true.

So, for instance, it follows from (PTE) that if Socrates is sitting and the proposition 'Socrates is sitting' exists, then the proposition 'Socrates is sitting' is true.

(Since on Buridan's view propositions are contingently existing sentence-tokens, it is entirely possible that the first conjunct of the antecedent of a substitution instance of (PTE) should be true without the second conjunct being true. Suppose, for instance, that Socrates were sitting but that no propositions existed. In that case Socrates would be sitting even though the proposition 'Socrates is sitting' would not exist and hence would not be true. Indeed, some propositions are such that it is impossible for them to satisfy the antecedent of (PTE). Consider the proposition 'There are no negative propositions'. It is impossible that there should be no negative propositions and yet that the proposition 'There are no negative propositions' should exist. In such a case, the relevant substitution instance of (PTE) is true by virtue of having an impossible antecedent.)

(PTE), I think we can agree, has an aura of truth about it. But now consider the following argument:

    (6) (A) is false. (assumption)
    (7) If (A) is false, then (A) exists. (premise) /80/
    (8) So (A) exists. (6,7)
    (9) But necessarily, if (A) is false and (A) exists, then (A) is true. (PTE)
    (10) So (A) is true. (6,8,9)

Buridan responds here by rejecting the claim that (10) follows from (6), (8) and (9), on the grounds that far from being a true and innocuous non-self-referential statement about the sophism (as is (6)), the first conjunct of the antecedent of (9) in fact just is the sophism--and the sophism, of course, is false and not true. Hughes gives a more complicated, disjunctive response to the argument discussed on pp. 25-27, a response calculated to work regardless of whether or not the first conjunct of the antecedent of (9) is taken to be the sophism. But, as before, both Buridan and Hughes presuppose (i) that the sophism is false and (ii) that this claim about the sophism can justifiably be used to undermine the attempt to derive the sophism's truth from its falsity. And, again as before, neither Buridan nor Hughes seems to exhibit any qualms about the dialectical propriety of this tactic.

How might Buridan and his followers respond here? Perhaps they could plausibly claim that they are not obliged to provide a non-question-begging answer to the two arguments laid out above. More concretely, they might insist that because their proposal for handling the sophisms in question stands alone in preserving the principle of bivalence, it automatically wins out over its competitors as long as it can be shown to be merely consistent. So, they might continue, the objection pressed above rests on a mistaken picture of the dialectical milieu in which the debate between Buridan and Hughes, on the one hand, and their opponents, on the other hand, is taking place.

I am willing to concede that this line of response shows some promise, though it obviously raises further questions that must be addressed forthrightly. For instance, those who, unlike Buridan, distinguish sharply between sentence-tokens and propositions might well hesitate to attribute such overriding significance to the preservation of sentential (as opposed to propositional) bivalence. Indeed, one who reflects upon the matter carefully might find it intuitively more evident that neither (B) nor (C) above expresses a proposition than that bivalence holds for all syntactically well-formed sentence-tokens. It would be interesting to have Hughes' thoughts on this matter.

In any case, it is fitting that Buridan, properly packaged and interpreted, should be able to contribute, in propria persona as it were, to the lively contemporary discussion of self-reference. Hughes tells us that his main concern has been "to make Buridan's ideas accessible to present day philosophical readers for the sake of their inherent importance." In this he has succeeded admirably.

1. To be exact, Buridan takes a proposition to be a meaningful sentence-token that is spoken or written or (in the case of the mental language) thought with assertive intent.

2. Philosophers who hold that the sophisms in question are neither true nor false /81/ fall into two broad classes. Included in the first class are those who deny that the sophisms are (or express) propositions and hence deny that they have truth-values at all. The second class comprises those who affirm that the sophisms are propositional and thus that they have truth-values, but who deny that they have classical truth-values. The latter group of philosophers (at least) must, of course, still contend with the so-called 'strengthened liar', e.g.,

    (D) (D) is either false or neither true nor false.

(D), it seems, is true if false, false if true, and true if neither true nor false. On Buridan's theory, by contrast, (D) is simply false, and so it poses no new problems not already posed by (A), (B) and (C).

3. I will not bother to restate (3), (4) or (T) below in Fregean terms. But it is important to see that Buridan's resolution of the alethic paradoxes in no way depends upon his preference for a two-name account of predication over a function-argument account.

4. Condition (ii) could also be stated as follows: There is something for which both '"N is P"' and 'true' supposit in the proposition '"N is P" is true'.