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Although the frequency stability of a typical TCXO is more than an order of magnitude worse than a precision OCXO, their acceleration sensitivities are often similar. This means that their dynamic stability and phase noise will also be similar since the vibratory performance is determined by the Γ characteristic and the applied acceleration level and is largely independent of the static phase noise and frequency stability. Unless Γ and/or a are extremely small, any random vibration will cause the noise floor of the oscillator to rise. The phase noise degradation that occurs in a 10-MHz TCXO with Γ of 2.5 ppb/g is shown in Fig. 7

Manage Quartz Crystals Under High Vibration, Fig. 7

If it is determined that the acceleration sensitivity of an oscillator must be improved to meet system specifications, there are several approaches that can be considered. If the highest vibration levels come primarily along one axis, it may be possible to mount the oscillator so that the Γ vector is perpendicular to the axis of vibration o that the vibration is applied along the plane of “zero” sensitivity. In some instances, a 10:1 improvement could be realized with this approach. In most real-world applications, however, there is significant vibration present in all axes, so this approach may be of limited benefit.

Special crystal design techniques can be used to reduce the acceleration sensitivity to some degree. Precision SC-cut resonators that employ unique stress relieved mounting structures are available that exhibit acceleration sensitivities as low as 0.2 ppb/g. Other crystals, such as certain rectangular strip-type crystals, can be manufactured with special mountings that achieve sensitivities as low as 0.1 ppb/g with some yield.

Mechanical vibration isolators can be effective in some applications by reducing the vibration energy that is conducted to the oscillator. Isolators act as lowpass filters: attenuating the vibration energy above their natural resonant frequency, but passing all of the energy below said frequency. This frequency is dependent upon the stiffness of the isolator and the weight of the supported assembly. With a small, lightweight assembly such as an oscillator, it is difficult to achieve effective attenuation below a few hundred Hz. And depending upon the “Q” of the structure, the vibration energy is actually amplified near the natural frequency. Care must be taken to ensure sufficient “sway room” to allow for movement of the assembly, especially if excited near the resonant frequency.

Other considerations with mechanical isolators include directional dependence, changes in their stiffness over temperature, additional weight to lower the resonant frequency, and the space required to mount the assembly. A properly designed isolation system can be quite effective in reducing high-frequency vibration energy. However, a system which is not properly designed can actually make performance worse under some conditions.

Even after many years of work, there has been little progress in producing resonators with sensitivities below the low parts in 1010/g level. In order to achieve better performance, some sort of compensation must be used. There are two basic types of compensation: active and passive. Active techniques employ an acceleration-sensitive component such as an accelerometer to sense the applied vibration or acceleration. That signal is then processed with the proper amplification and phase reversal and fed back to the oscillator to cancel the effects of the vibration on the resonator.

This method can be quite effective, producing oscillators with Γ to low parts in 1012/g at lower vibration frequencies. But as the vibration frequencies increase beyond about several hundred Hz, it becomes very difficult to maintain the amplitude and phase linearity required to sustain those levels for cancellation. And adding the required circuitry significantly increases the size and cost of the oscillator.

Manage Quartz Crystals Under High Vibration, Fig. 8

Passive compensation methods employ multiple crystals which are carefully aligned to that their Γ vectors are aligned anti-parallel (pointing in exactly opposite directions). The acceleration-induced positive frequency shift of one resonator is therefore cancelled by a corresponding negative shift from the other resonator. The crystals are connected either in series or in parallel in the oscillator circuit and function as a single composite resonator.

This method has been known for more than 30 years,6 but has historically been difficult to implement due to lack of consistency in the Γ vectors of conventional crystals. Both the magnitude and the direction of Γ must be matched closely if significant cancellation is to occur. Recent advances in small AT-cut strip crystals designed for rugged applications have achieved better consistency in the Γ vector, enabling practical designs that achieve sensitivities in the low parts in 1011/g.7

Passively compensated TCXOs are now available that provide ultralow acceleration sensitivity in all axes. The performance of a passively compensated TCXO is shown in Fig. 8. Even under the same moderate random vibration, as shown in Fig. 6, the vibration induced noise is still below the quiescent phase noise of the oscillator since |Γ| is a very low 0.02 ppb/g or 2 × 10-11/g. Oscillators of this type are being produced to frequencies greater than 100 MHz.8 For applications where operation in the presence of significant vibration is required, this type of passively compensated crystal oscillator may provide the best combination of critical performance for the cost.

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Meanings Are Syntactically Individuated and Found in the Head

Expanding on some of Chomsky’s recently expressed views of meaning in a way that is consistent with his long-held rationalist conception of mind, I show how syntax, broadly conceived, could individuate meanings and provide a science of meanings inside the head. Interpretation becomes a pragmatic matter, although a rationalist account of mind shows how internal meanings guide interpretation and, more generally, language use. In this view of meanings, interpretation, and mind, semantics as usually understood disappears.


Title: Glycolysis and swimming performance in juvenile American alligators
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00066449/00001
 Material Information
Title: Glycolysis and swimming performance in juvenile American alligators
Physical Description: Book
Creator: Gatten, Robert E. Jr.
Congdon, Justin D.
Mazzotti, Frank J.
Fischer, Robert U.
Affiliation: University of North Carolina -- Department of Biology
University of Florida -- Department of Wildlife and Range Science
Publisher: Society for the Study of Amphibians and Reptiles
Publication Date: 1991
General Note: Drawn from Journal of Herpetology, Vol. 25, No. 4, pp. 406-411, 1991
 Record Information
Bibliographic ID: UF00066449
Volume ID: VID00001
Source Institution: University of Florida

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loirnal of 'ol. 25, No. 4, pp 406-411, 1991
Copyrghs for the Shidy of Amphibians and Reptles

Glycolysis and Swimming Performance in
Juvenile American Alligators

'Department of ... .l University of North Carolina, Greensboro, North Carolina 27412, USA,
'Savannah River Ecology Laboratory, Drawer E, Alken, South Carolina 29801, USA, and
'Department of Wildlife and ** Science, Uniersity of Florida, Broward County Extension ( ,;
3245 < '.. .' Avenue, Davie, Florida 33314, USA

ABSTRACT.-Swimming speed of juvenile American alligators increased between 15 and 20 C but not
between 20 and 30 C. Speed declined with time during the 4 min trials. Post-exercise lactate concentration
increased with temperature and with duration of swimming. The rate of lactate formation during exercise
increased with temperature and was higher in the first min of excerise than in the subsequent 3 min. Once
the effects of temperature, body mass, and body length were removed, there was no relationship between
the intensity of glycolysis and the distance covered in 1 min of swimming. In contrast, the alligators that
swam the greatest distance in 4 min had the lowest lactate concentration. Thus, the relationship between
the intensity of glycolysis and distance traveled varies with the duration of exertion in these animals
during induced swimming.

Because crocodilians swim like fish, gallop
like mammals, and exhibit an unusual "high
walk" during routine terrestrial locomotion,
their locomotor behavior and mechanics have
intrigued biologists for many years f ,-
1940; Colbert et al., 1946; Zug, 1974; Fish, 1984;
Turner et al., 1985). It is implicit in such studies
of locomotion that the results seen at the level
of behavior are directly or indirectly traceable
to, and dependent upon, .. .. .. physio-
logical processes. There is ample evidence link-
ing locomotor behavior and locomotor physi-
ology in reptiles and .. -- :.: For example,
species with high locomotor stamina usually
possess a high aerobic capacity whereas species
with low endurance i t exhibit a low rate
of oxygen consumption and a high reliance on

glycolysis during intense exercise (Bennett,
1982; Taigen and Pough, 1985; Gatten et al.,
1992). In spite of our extensive knowledge of
the association between locomotor physiology
and behavior among species of :'-.: or am-
phibians, there is very little evidence to support
the contention that this linkage between phys-
iological capacity and behavioral ability exists
among individuals of a single species. For ex-
ample, individual toads with a high rate of ox-
ygen consumption during exercise did not ex-
hibit better locomotor performance than
individuals with a low aerobic capacity either
in laboratory trials '..- 1988) or in field
tests (Wells and Taigen, 1984; Walton, 1988).
Likewise, there was no direct association be-
tween sprint speed and limb muscle glycolytic

enzyme activity among individual lizards
(Gleeson and Harrison, 1988) or frogs (Marker,
1990). These results are surprising in light of
the generally held belief that behavior is lim-
ited by the capacities of :-- . 1 : .; processes.
During short-term intense exercise, most rep-
tiles rely on glycolysis to provide a major por-
tion of the ATP used by active muscles (Bennett,
1982). For example, during exhaustive exercise
lasting 4.6-7.0 min, juvenile crocodiles, Croco-
.:.::. :.. .. derived 60-80% of the needed ATP
from glycolysis (Wright, 1986). Other studies
with crocodilians indicate that both glycolysis
and aerobic metabolism increase with muscular
S;: ::. (Coulson and Hernandez, 1979; Bennett
et al., 1985; Lewis and Gatten, 1985; Seymour
et al., 1987). In most cases, glycolysis is most
important during the early phase of a bout of
exercise when the respiratory and cardiovas-
cular systems have not yet reached their peak
ability to deliver oxygen to the active muscles
(Gatten, 1985; Wine, 1988). However, even in
:.... :. activities such as .. :... migration
and nest construction, glycolysis may play a
minor role (Congdon and Gatten, 1989). The
ability of juvenile American alligators,,: *
mississippiensis, to escape from aquatic predators
such as fish, turtles, snakes, birds, and conspe-
cifics may well depend on their capacity to uti-
lize glycolysis to power vigorous swimming
shortly after they perceive a predator. There-
fore, in this study we chose to examine the
strength of association between locomotor per-
formance, a behavior that is likely to be of con-
siderable ecological significance, and glycolysis
in a groupofyoung ..... Wehypothesized
that individuals with high locomotor perfor-
mance during intense exercise will be those in-
dividuals with high reliance on glycolysis.

iA i. ; .' eggs were obtained from nests on the
Rockefeller Wildlife Refuge, Grand Chenier,
Louisiana, and transported to the Savannah
River Ecology Laboratory where they were
placed in incubators in moistened vermiculite
at 30 or 34 C until hatching. Juveniles were
maintained in a covered building exposed to
natural variation in photoperiod and tempera-
ture for 10 weeks. Animals from each clutch
were randomly distributed among treatments.
A total of 69 alligators (mean mass = 65.40 g,
range = 38.50-97.67 g; mean snout-vent length
= 13.8 cm, range = 11.1-16.0 cm; mean total
length = 28.8 cm, range = 22.0-34.0 cm) were
used in studies of locomotion at 15, 20, and 30
C. The arena used for these tests was an oval
trough, 920 cm in mean circumference and 32.5
cm wide, with water 8 cm deep. The water was
maintained at 14.8-15.2, 20.0-20.3, or 29.9-30.2

C by circulating it between the trough and ex-
ternal tubs cooled or heated to a constant tem-
perature. Prior to testing animals were kept
overnight in a constant temperature cabinet at
15, 20, or 30 C. Animals were removed individ-
ually from the constant temperature cabinet and
placed in the arena at the starting line. We in-
duced the alligators to swim by prodding them
with a blunt stick and recorded the distance
they had traveled after 1, 2, 3, and 4 min. The
animals swam at the surface of the water with
their limbs pressed against their bodies and with
propulsive force being provided by lateral un-
dulations of the tail. Animals were prodded
whenever their forward movement ceased. Im-
mediately after a stimulus by the blunt stick,
they usually exhibited a brief burst of intense
swimming followed by vigorous, continuous
swimming at the surface. Some animals were
removed from the arena at 1 min whereas others
were observed for the entire 4 min period be-
fore being removed. Upon removal, each ani-
mal was quick-frozen by immersion in liquid
nitrogen. In addition, animals that had been
resting overnight at 20 or 30 C were quickly
removed from the constant temperature cabinet
and frozen to serve as references for the swim-
ming animals.
Frozen animals were analyzed for total body
lactate concentration by homogenizing them in
perchloric acid, centrifuging and filtering the
homogenate, and analyzing the homogenate in
duplicate for lactate by an enzymatic technique
( .... 1974). See Gatten (1987) for details.
Data were analyzed with the General Linear
Models program of SAS (SAS Institute, 1985).
Swimming performance (distance covered in
each minute = speed in cm min ) was initially
assessed by analysis of covariance, with total
body length as the covariate, and temperature
and duration of swimming (1, 2, 3 or 4 min) as
independent variables. This analysis utilized a
repeated-measures design within each temper-
ature because each animal's performance was
measured at four different times. Subsequently,
the relationship between : .f .. ... during
minutes 1, 2, and 3 and performance during
subsequent minutes was analyzed using Spear-
man's rank correlation analysis. Total body lac-
tate data were subjected to analysis of covari-
ance, with body mass as the covariate, and
temperature and duration of swimming as in-
dependent variables. In order to assess the re-
lationship between lactate concentration and
distance covered in I or 4 min of swimming,
the effects of body mass, total body length, and
temperature on post-exercise lactate level and
on distance at 1 or 4 min were computed by
multiple analysis of variance. The differences
between the observed values and those pre-

TABLE 1. Swimming performance of :,' - al-
ligators (in cm min '). Values shown are the mean
distance traveled per minute (=speed) in each of the
four minutes of swimming, adjusted for differences
in body .. . :- .... the 95% confidence intervals. Q,,
values, which indicate the effect of temperature change
on swimming speed, are also shown. Nine animals
were used at each temperature.

Min- Temperature (C) and Q,,
ute 15 Q,, 20 Q, 30
1 717 3.46 1334 1.19 1583
611-823 1087-1581 1292-1874
2 415 3.94 824 1.22 1002
296-534 616-1032 795-1209
3 318 4.26 656 1.05 688
234-402 481-831 525-851
4 227 5.53 534 1.04 555
119-335 379-689 370-740

dicted by the model were then calculated. The
relationships between the residuals for lactate
level and the residuals for distance were then
analyzed and partial correlation coefficients
were calculated. Linear regression was used to
examine the relationship between the 4
in performance during the 4 min trials and the
lactate concentration at the end of 4 min for
each temperature and for all temperatures com-
bined. Statistical significance was declared at P
< 0.05.

Swimming Performance.-The locomotor per-
formance of the ,::,..,. ., as measured by the
distance traveled in each minute, increased with
total body length (F,,a = 8.08, P = C: .-' -- In
general, the distance traveled (adjusted for dif-
ferences in body length) increased with tem-
perature (F,,3 = 25.58, P < 0.0001; Table 1).
However, the effect of temperature was appar-
ent only between 15 and 20 C (P < 0.001); swim-
ming speed did not change between 20 and 30
C (P = 0.2468). This pattern was the same when
data for each minute were analyzed individu-
ally. The distance traveled in each minute de-
creased over the four minutes of swimming (F,,
= 114.12, P < 0.0001; Fig. 1). Furthermore, there
was an interaction between temperature and
the swimming interval (F6,72 = 5.07, P = 0.0002);
this means that the effect of temperature on
performance changed as the animals continued
For all temperatures combined, swimming
distance in any one minute was positively as-
sociated with performance in any subsequent
minute (Spearman's r > 0.65, df = 25, P < 0.0005
in all six comparisons). This means that an al-

------ 30C
---*-- 20C
------ 15C

4 S

Time (min)
FIG. 1. Swimming performance of juvenile alli-
gators during four minute,' ., ,.
Each point indicates the distance covered in a single
minute of swimming. Values shown are means and
95% confidence intervals.

'. that swam well in the first minute was
likely to swim well in subsequent minutes.
However, this relationship varied with tem-
perature. At 15 C, the distance covered in any
one minute interval had no relation to the dis-
tance swum in any subsequent interval (r <
0.49, df = 7, P > 0.18 in all six comparisons).
This lack of an association at 15 C was in part
due to the fact that swimming performance var-
ied less among individuals at this temperature
than at higher temperatures (Fig. 1). For alli-
gators at 20 C, the distance traveled in the first
minute was positively associated with perfor-
mance in the third minute; other positive cor-
relations were between distance in minutes 2
and 3 and in minutes 3 and 4 (Table 2). At 30
C, performance in the first minute had no re-

TABLE 2. Spearman rank correlations between per-
formance in each one minute interval and all sub-
sequent one minute intervals at 20 and 30 C. In each
case N = 9, df = 7.

Tem- Subsequent
perature Minute minute
(C) interval interval r P
20 1 2 0.58 0.0972
1 3 0.72 0.0289
1 4 0.47 0.2039
2 3 0.73 0.0239
2 4 0.45 0.2230
3 4 0.85 0.0041
30 1 2 0.25 0.5215
1 3 0.30 0.4372
1 4 0.22 0.5802
2 3 0.93 0.0005
2 4 0.80 0.0097
3 4 0.75 0.0195

TABLE 3. Lactate concentration of juvenile *ii, *
tors (in Ag g '). Values shown are the mean values
for animals sampled at rest and after one and four
minutes of swimming, adjusted for differences in body
mass, (sample size), and 95% confidence intervals.

Temperature (C)
Minute 15 20 30
0 51 (7) 94 (7)

167 (9) 559 (10)
76-258 474-644

799 (9)

TABLE 4. Rate of lactate formation (pig lactate g
min ) in swimming alligators. Calculations are based
on values in Table 3. Q, values are also shown.

Interval Temperature (C) and Q,,
(min) 15 Qo 20 Q,, 30

116* 19.18 508
35 6.04 86
55* 12.19 192

1.39 705
1.38 119
1.38 265

Based on a resting lactate value of 51 ig g-', determined
at 20 C

4 272 (9) 817 (9) 1155(9) that swam the greatest distance had the lowest
181-363 726-908 1064-1246 lactate concentration (r = -0.62, df = 21, P =
0.0017; Fig. 2). The rate of change in swimming
speed during the 4 min trials was not correlated
on to swimming distance in subsequent with the total body lactate concentration at the
nutes; however, distance traveled in minute end of the trial at any temperature (15 C: r =
ias positively correlated with performance 0.04, df 7, P 9090; 20 C: r 0.31, df
minutes 3 and 4 (Table 2). Likewise at 30 C, 7, P = 0.4177; 30 C: r = -0.40, df = 7, P = 0.2822).
tances in minutes 3 and 4 were positively However, when data for all temperatures were
related (Table 2). The absence of negative pooled, the animals with the steepest decline
: i.. between distances in various in- in swimming speed over the 4 min test were
vals means that there were no animals that the individuals with the highest lactate con-
re good "starters" but poor "finishers," or centration at the end of the trial (r = 0.69, df
e versa. = 25, P < 0.001).
e versa.
-. Lactate concentration of resting DIScussION
gators did not vary with temperature (F,, Perfr ce-The swimming be,
.00, P = 0.3397; Table 3). Active animals had Performance-The swimming be-
igher lactate level than did resting animals havior of the alligators in this study was essen-
44 = 227.54, P < 0.0001). Lactate concentra- tially that described by Manter (1940), Fish
nof swimming ,:... ,: .. increased with body (** i: and Turneretal. (1985). There were brief
ss (F,,, = 6.12, P = 0.0170); thus, body mass intervals of burst swimming interspersed among
s used as a covariate in all subsequent anal- longer periods of intense but steady effort at
. T, i .1 ,. .. ;i .. i ;-. the water surface. Animals sometimes appeared

yse I Ie v x g m
creased with temperature (F.,, = 182.37, P <
0.0001) and was higher for animals ..:......
for 4 min than for those active for only 1 min
(Ff,,4 = 56.17, P < 0.0001). Furthermore, there
was an interaction between temperature and
duration of exercise (F,,, = 5.21, P = 0.0090);
this resulted from the fact that as temperature
increased from 15 to 30 C, the increase in lactate
concentration between 1 and 4 min of swim-
ming became larger.
The rate of lactate formation during swim-
ming increased with temperature, more steeply
between 15 and 20 C than between 20 and 30
C (Table 4). The rate at which lactate accumu-
lated during the first minute of exercise was
3.3-5.9 times that during the subsequent three
minutes (Table 4).
Relation between Performance and Glycolysis.-
Once the effects of body length, body mass, and
temperature were removed, there was no rela-
tionship between lactate concentration and dis-
tance covered in 1 min of swimming (r = -0.01,
df = 22, P = 0.9670). A similar analysis for data
at 4 min of swimming indicated that the animals

400 -

> *
a Sa

O0 -600 0 S00 1200

Residual for Distance (cm)
FiG. 2. The relationship between whole-body lac-
tate concentration and distance covered in juvenile
i. mming for 4 min. The points shown are
the residual values remaining after removal of the
effects of temperature, body mass, and body length.
The linear regression equation is: y = -0.11 0.14x,
r = -0.62, df = 25, P < 0.001.

2 w

= 1

to ventilate their lungs but we recorded no data
on frequency of breathing during the exercise
bouts. Larger: . ...... animals swam faster than
smaller (shorter) ones, which was expected.
Temperature exerted a strong effect on swim-
ming performance between 15 and 20 C but no
effect between 20 and 30 C, a pattern similar to
that found by Turner et al. (1985) for burst speed
in swimming fi:. :
Swimming speed was highest in the first min-
ute of the trials and then decreased over the
subsequent 3 min. In general, animals retained
their rank for swimming speed over the 4 min
trial; the best swimmers in the first minute were
also the best performers in subsequent minutes.
The decline in speed over time was presumably
the result of the accumulation of metabolites of
glycolysis which lead to fatigue in crocodilians
and other vertebrates (Bennett et al., 1985; Sey-
mour et al., 1985, 1987; Nosek et al., 1987). The
speed of our alligators in the first minute of
swimming was only 26-31% of the speed of
those of Turner et al. (1985) that were engaged
in burst swimming lasting only 3-6 sec at the
same temperatures we used. This comparison
between our results and Turner's is complicated
by the fact that his animals had body masses
about 10 times those of ours, and by the fact
that his data were not adjusted for differences
among individuals in body length. Stamina in
swimming crocodiles (Crocodylus porosus) is size-
dependent; animals of less than I kg exhaust in
about 5 min, whereas large adults may not ex-
haust until after 30-50 min of effort (Seymour
et al., :i'-. Thus, studies of locomotor perfor-
mance in crocodilians must always control for
variation in body size among individuals.
-Larger animals had higher post-
exercise whole body lactate levels than smaller
animals. Bennett et al. (1985) report a similar
i,:. .. ..; between body size and blood lac-
tate concentration in crocodiles (Crocodylus po-
rosus) exhausted during capture in the field. In
the present .. -1., large animals swam farther
than smaller ones whereas in the study of Ben-
nett et al. (1985), large animals struggled longer
than smaller ones. Therefore, the high amount
of lactate accumulated in large -.. .. : .' in
comparison with smaller ones, may reflect a
greater cumulative effort and/or a higher tol-
erance for blood acid base disturbance.
The thermal sensitivity of !. !. : between
15 and 20 C during the first minute of exercise
(Qi = 19.18) was much greater than during the
subsequent 3 min (Q0 =- 1.39). The former very
high value is atypical of that for other reptiles
in which Q,o for glycolysis is generally between
1.1 and 1.3 (Bennett, 1982). Likewise, the pat-
tern of an abrupt change in Q,, for glycolysis
between 15-20 C and 20-30 C is most unusual

for reptiles (Gatten, 1985, eq. 1). Furthermore,
the absolute value for the rate of lactate for-
mation found here for animals active for 1 min
at 15 C is only 15% of the comparable value for
squamate reptiles (Gatten, 1985, eq. 1). Togeth-
er, these facts indicate that the ability of juve-
nile i..: ...... to power short-term locomotion
by '.. below 20 C is very low. Glycolysis
at all temperatures during the early portion of
exercise was more intense than during the latter
portion, a pattern typical of other reptiles (Gat-
ten, 1985).
t'.. and Performance.-In spite of the
substantial accumulation of lactate during the
first minute of exercise .. : .- at 20 and 30
C), there was no relationship between post-ex-
ercise lactate level and distance traveled. This
result implies that although active muscles are
generating ATP by glycolysis, the magnitude
of this process is not directly coupled with the
extent of forward movement in the first minute
of exercise. This finding is contrary to our gen-
eral understanding of the importance of gly-
colysis to locomotor performance during short-
term burst exercise in ...., : .. .. and reptiles
(Gatten, 1985). Perhaps the "stress" induced by
the experimental conditions elicited catechol-
amine-induced glycolysis (Coulson and Her-
nandez, : .- in this case, the lactate level at
the end of swimming reflected that due to gly-
colysis in active muscles and that due to hor-
mone-stimulated -1. :. : in the liver.
When the i:. .. ; between lactate con-
centration and performance at 4 min is exam-
ined, the result is that there is an inverse re-
lation between these two variables: the animals
relying least on :.1 I : swim the greatest
distance. Furthermore, the rate of decline in
swimming speed over the 4 min trial was most
pronounced in animals with a high lactate level.
These findings imply that (1) extensive reliance
on glycolysis is detrimental to prolonged lo-
comotion, and (2) the best performers (in terms
of distance covered in 4 min) are those that .
least on .- ' It is possible that a high rate
of glycolysis early in a prolonged bout of ex-
ercise results in levels of glycolytic endproducts
that inhibit aerobic processes, leading to a re-
duction in . locomotor ability. It
would appear that the negative effects of gly-
colytic endproducts on muscle function and/
or blood gas transport outweigh the benefits of
glycolytic ATP generation during 4 min of in-
tense effort in juvenile .:: .. : .. This -:.. ..,.
reinforces the understanding that 1 ..1 : is
most important during the early stages of ex-
ercise in ectothermic vertebrates and that vig-
orous locomotion lasting more than one minute
must be powered largely by aerobic, rather than
anaerobic, pathways.

/. .' -Funding for this research
was provided through contract DE-ACO9-
76SR00-819 between the United States Depart-
ment of 7 - .. and the University of Georgia's
Savannah River Ecology Laboratory; the De-
partment of Biology and Research Council of
the University of North Carolina at Greensboro;
and Oak Ridge Associated Universities Travel
Contracts S-1942 to REG, Jr., and S-3244 to FJM.
We are grateful to R. Wine for technical assis-
tance and D. Ludwig for statistical assistance.

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1987. Activity metabolism of anuran am-
phibians: tolerance to dehydration. Physiol Zool.
--, K. MILLER, AND R. FULL. 1992. Energetics at
rest and during locomotion. In M. E. Feder and W.
W. i ... (eds.), Environmental i. i of
the Amphibians. Univ. Chicago Press, Chicago.
GLEESON, T. T., AND J. M. HARRISON 1988. Muscle
composition and its relation to sprint running in
the lizard Dipsosaurus dorsalis. Amer. J. Physiol.

LEWIS, L. Y., AND R. E GATTEN, JR. 1985. Aerobic
metabolism of American .::- .. .. ms-
sissippiensis, under standard conditions and during
voluntary activity. Comp. Biochem. Physiol. 80A(3):
MANTER, J. R. 1940. The mechanics of swimming in
the ,',. .. J. Exp. Zool. 83:345-358.
MARKER, G. M. 1990. Interindividual variability in
sprint performance, lactate production, and en-
zyme activity in Rana pipiens. Unpubl. MA. Thesis,
Univ. North Carolina, Greensboro. 49 pp.
NOSEK, T. M., K. Y. FENDER, AND R. E. GODT. 1987. It
is diprotonated inorganic phosphate that depress-
es force in skinned skeletal muscle fibers. Science
SAS INSTITUTE. 1985. SAS User's Guide: Statistics.
SAS Institute, Cary, North Carolina. 956 pp.
1985. Blood gas tensions and acid-base regulation
in the salt-water crocodile, Crocodylus porosus, at
rest and after exhaustive exercise. J. Exp. Biol. 118:
FORD. 1987. Effect of capture on the physiology
of Crocodylus porosus. In G . W. Webb, S. C. Mano-
lis, and P. J. Whitehead (eds.), Wildlife Manage-
ment: Crocodiles and *. :,. '.. pp. 253-257. Sur-
rey Beatty and Sons, ( , Norton, New South
Wales, Australia.
TAIGEN, T. L., AND F. H. POUCH. 1985. Metabolic
correlates of anuran behavior. Amer. Zool. 25(4):
1985. Burst swimming of : .. ,. and the effect
of temperature. J. Herpetol. 19(4):450-458.
WALTON, M. 1988. ,: .- :... among metabolic,
locomotory, and field measures of organismal per-
formance in the Fowler's toad (Bufo woodhousei
fowleri. Physiol. Zool. 61(2):107-118.
WELLS, K. D., AND T. L. TAIGEN. 1984. Reproductive
behavior and aerobic capacities of male American
toads (Bufo americanis): is behavior constrained by
S. ...i .. Herpetologica 40(3):292-298.
WINE, R. N. 1988. The effect of temperature on the
anaerobic support of locomotion in Anolis caroh-
nensis and Rana pipiens. Unpubl. M.A. Thesis, Univ.
North Carolina, Greensboro. 56 pp.
WRIGHT, J.C. 1986. Effects of body temperature, mass,
and activity on aerobic and anaerobic metabolism
in juvenile Crocodylus porosus. Physiol. Zool. 59(5):
ZUG, G. R. 1974. Crocodilian an unique
gait for reptiles. Copeia 1974(2):550-552.

Accepted: 7 June 1991.

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weeping lovegrass USDA PLANTS SYMBOL: ERCU2
Eragrostis curvula (Schrad.) Nees
Synonym(s): Boer love grass

Eragrostis curvula is a warm-season, perennial grass that can grow to 4 ft. (1.2 m) tall.
Leaves are arched, 0.11-0.16 in. (3-4 mm) wide, flat, with ciliate ligules. Sheaths have long hairs inside the upper margin and along the collar. Spikelets are nodding, 0.2-0.4 in. (4-10 mm) long, 0.06-0.07 in. (1.5-2 mm) wide and gray-green.
Flower spikelets are elongated, flattened, and have 4 to 13 small flowers. Flowering occurs during early summer and continues through fall.
Seed heads are panicles that contain many tiny seeds. The seed heads can grow from 30-40 in. (0.8-1 m) tall
Ecological Threat
Eragrostis curvula inhabits disturbed places such as roadsides and is native to South Africa. It has been planted for erosion control in the southwestern United States and is also used widely as an ornamental.

Identification, Biology, Control and Management Resources


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The electro-pop duo Cherub is dance music which is one part '80s funk and one part future pop. Jordan Kelley and Jason Huber take the throwback sounds of old drum machines and keyboards and marry them with timeless lyrics. Background guitar and synthesizer add a hint of dance music. Cherub's debut album, 'Man of the Hour,' represents Kelley's songwriting and voice and Huber's guitar skills.


Fluoride Action Network

National Research Council (2006)

NRC’s Findings

The National Research Council’s report concluded that EPA’s safe drinking water standard (4 ppm) for fluoride is unsafe and “should be lowered.” The NRC based this conclusion on its finding that EPA’s 4 ppm standard places a person at increased risk for both tooth damage (severe dental fluorosis) and bone damage (bone fracture). While most of the press coverage of the NRC report focused on NRC’s concerns with teeth and bone, there are many other serious concerns expressed in the NRC report. As evident in the following excerpts, the NRC report lends credence to fluoride’s ability to affect a wide range of systems in the body, particularly the brain and endocrine system. These concerns are further amplified in the NRC’s research recommendations.

To read the NRC’s complete discussion of fluoride’s effect on the brain, click here.

“histopathological changes similar to those traditionally associated with Alzheimer’s disease in people have been seen in rats chronically exposed to AlF.” p.212

“Additional animal studies designed to evaluate reasoning are needed.” p.223

“In summary, evidence of several types indicates that fluoride affects normal endocrine function or response; the effects of the fluoride-induced changes vary in degree and kind in different individuals. Fluoride is therefore an endocrine disruptor in the broad sense of altering normal endocrine function or response, although probably not in the sense of mimicking a normal hormone. The mechanisms of action remain to be worked out and appear to include both direct and indirect mechanisms, for example, direct stimulation or inhibition of hormone secretion by interference with second messenger function, indirect stimulation or inhibition of hormone secretion by effects on things such as calcium balance, and inhibition of peripheral enzymes that are necessary for activation of the normal hormone.” p.266

To read the NRC’s complete discussion of fluoride’s effect on the thyroid, click here.

“several lines of information indicate an effect of fluoride exposure on thyroid function.” p.234

“it is difficult to predict exactly what effects on thyroid function are likely at what concentration of fluoride exposure and under what circumstances.” p.234-5

“Fluoride exposure in humans is associated with elevated TSH concentrations, increased goiter prevalence, and altered T4 and T3 concentrations; similar effects on T4 and T3 are reported in experimental animals..” p.262

“In humans, effects on thyroid function were associated with fluoride exposures of 0.05-0.13 mg/kg/day when iodine intake was adequate and 0.01-0.03 mg/kg/day when iodine intake was inadequate.” p.262-3

“The recent decline in iodine intake in the United States (CDC 2002d; Larsen et al. 2002) could contribute to increased toxicity of fluoride for some individuals.” p.263

“Intake of nutrients such as calcium and iodine often is not reported in studies of fluoride effects. The effects of fluoride on thyroid function, for instance, might depend on whether iodine intake is low, adequate, or high, or whether dietary selenium is adequate.” p.265

“Nevertheless, patients who live in either an artificially fluoridated community or a community where the drinking water naturally contains fluoride at 4 mg/L have all accumulated fluoride in their skeletal systems and potentially have very high fluoride concentrations in their bones. The bone marrow is where immune cells develop and that could affect humoral immunity and the production of antibodies to foreign chemicals.” p.293-4

“bone concentrates fluoride and the blood-borne progenitors could be exposed to exceptionally high fluoride concentrations. Thus, more research needs to be carried out before one can state that drinking water containing fluoride at 4 mg/L has no effect on the immune system.” p.295

“it is important to consider subpopulations that accumulate large concentrations of fluoride in their bones (e.g., renal patients). When bone turnover occurs, the potential exists for immune system cells and stem cells to be exposed to concentrations of fluoride in the interstitial fluids of bone that are higher than would be found in serum. From an immunologic standpoint, individuals who are immunocompromised (e.g., AIDS, transplant, and bone-marrow-replacement patients) could be at greater risk of the immunologic effects of fluoride.” p.302

“Within 250 µm of a site of resorption, it is possible to encounter progenitor cells that give rise to bone, blood, and fat. Thus, one must assume that these cells would be exposed to high concentrations of fluoride. At this time, it is not possible to predict what effect this exposure would have on the functioning of skeletal elements, hematopoiesis, and adipose formation.” p.142

“Available information now indicates a role for aluminum in the interaction of fluoride on the second messenger system; thus, differences in aluminum exposure might explain some of the differences in response to fluoride exposures among individuals and populations.” p.265

“With the increasing prevalence of acid rain, metal ions such as aluminum become more soluble and enter our day-to-day environment; the opportunity for bioactive forms of AlF to exist has increased in the past 100 years. Human exposure to aluminofluorides can occur when a person ingests both a fluoride source (e.g., fluoride in drinking water) and an aluminum source; sources of human exposure to aluminum include drinking water, tea, food residues, infant formula, aluminum-containing antacids or medications, deodorants, cosmetics, and glassware.” p.51

“Further research should include characterization of both the exposure conditions and the physiological conditions (for fluoride and for aluminum or beryllium) under which aluminofluoride and beryllofluoride complexes can be expected to occur in humans as well as the biological effects that could result.” p.52

“Another possible explanation for increased blood lead concentrations which has not been examined is the effect of fluoride intake on calcium metabolism; a review by Goyer (1995) indicates that higher blood and tissue concentrations of lead occur when the diet is low in calcium. Increased fluoride exposure appears to increase the dietary requirement for calcium (see Chapter 8); in addition, the substitution of tap-water based beverages (e.g., soft drinks or reconstituted juices) for dairy products would result in both increased fluoride intake and decreased calcium intake.” p.52

“[G]iven the expected presence of fluoride ion (from any fluoridation source) and silica (native to the water) in any fluoridated tap water, it would be useful to examine what happens when that tap water is used to make acidic beverages or products (commercially or in homes), especially fruit juice from concentrate, tea, and soft drinks. Although neither Urbansky (2002) nor Morris (2004) discusses such beverages, both indicate that at pH < 5, SiF6 2- would be present, so it seems reasonable to expect that some SiF6 2- would be present in acidic beverages but not in the tap water used to prepare the beverages. Consumption rates of these beverages are high for many people, and therefore the possibility of biological effects of SiF62-, as opposed to free fluoride ion, should be examined.” p.53

“A few human studies suggested that high concentrations of fluoride exposure might be associated with alterations in reproductive hormones, effects on fertility, and developmental outcomes, but design limitations make those studies insufficient for risk evaluation.” p.8

“The possible association of cytogenetic effects with fluoride exposure suggests that Down’s syndrome is a biologically plausible outcome of exposure.” p.197

“A reanalysis of data on Down’s syndrome and fluoride by Takahashi (1998) suggested a possible association in children born to young mothers. A case-control study of the incidence of Down’s syndrome in young women and fluoride exposure would be useful for addressing that issue. However, it may be particularly difficult to study the incidence of Down’s syndrome today given increased fetal genetic testing and concerns with confidentiality.” p.204

“The numerous fluoridation studies in the past failed to rigorously test for changes in GI symptoms and there are no studies on drinking water containing fluoride at 4 mg/L in which GI symptoms were carefully documented.” p.269

“GI effects appear to have been rarely evaluated in the fluoride supplement studies that followed the early ones in the 1950s and 1960s.” p.274

“The table suggests that fluoride at 4 mg/L in the drinking water results in approximately 1% of the population experiencing GI symptoms.” p.274

“Whether fluoride activates G proteins in the gut epithelium at very low doses (e.g., from fluoridated water at 4.0 mg/L) and has significant effects on the gut cell chemistry must be examined in biochemical studies.” p.280

“There are a few case reports of GI upset in subjects exposed to drinking water fluoridated at 1 mg/L. Those effects were observed in only a small number of cases, which suggest hypersensitivity. However, the available data are not robust enough to determine whether that is the case.” p.295

“It is possible that a lifetime ingestion of 5-10 mg/day from drinking water containing 4 mg/L might turn out to have long-term effects on the liver, and this should be investigated in future epidemiologic studies.” p.293

“future studies should be directed toward determining whether kidney stone formation is the most sensitive end point on which to base the MCLG.” p.281

“On the basis of studies carried out on people living in regions where there is endemic fluorosis, ingestion of fluoride at 12 mg per day would increase the risk for some people to develop adverse renal effects.” p.281

“Fluoride appears to have the potential to initiate or promote cancers, particularly of the bone, but the evidence to date is tentative and mixed (Tables 10-4 and 10-5). As noted above, osteosarcoma is of particular concern as a potential effect of fluoride because of (1) fluoride deposition in bone, (2) the mitogenic effect of fluoride on bone cells, (3) animal results described above, and (4) pre-1993 publication of some positive, as well as negative, epidemiologic reports on associations of fluoride exposure with osteosarcoma risk.“ p.336

“Because fluoride stimulates osteoblast proliferation, there is a theoretical risk that it might induce a malignant change in the expanding cell population. This has raised concerns that fluoride exposure might be an independent risk factor for new osteosarcomas.” p.134

“Osteosarcoma presents the greatest a priori plausibility as a potential cancer target site because of fluoride’s deposition in bone, the NTP animal study findings of borderline increased osteosarcomas in male rats, and the known mitogenic effect of fluoride on bone cells in culture (see Chapter 5). Principles of cell biology indicate that stimuli for rapid cell division increase the risks for some of the dividing cells to become malignant, either by inducing random transforming events or by unmasking malignant cells that previously were in nondividing states.” p.322

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NamePopularityRelated NamesRelatedNamesakesName DaysWebsitesImagesRatingsComments
Given Name OLIVER
GENDER: Masculine
OTHER SCRIPTS: Оливер (Serbian, Macedonian)
PRONOUNCED: AHL-ə-vər (English), AW-lee-ver (German), O-lee-ver (Finnish)   [key]
Meaning & History

Related Names
DIMINUTIVES: Oli, Ollie (English)
FEMININE FORMS: Olivera (Serbian), Olivera (Croatian), Olivera (Macedonian)
OTHER LANGUAGES: Olivier (Dutch), Olivier (French), Olivér (Hungarian), Oliviero (Italian), Noll (Medieval English), Olivier (Medieval French), Oliwier (Polish)
United States  ranked #19
England and Wales  ranked #1
Canada (BC)  ranked #1
Australia (NSW)  ranked #1
Austria  -
Catalonia  ranked #74
Czech Republic  ranked #33
Denmark  ranked #9
Finland  ranked #5
Hungary  ranked #22
Iceland  ranked #13
Ireland  ranked #40
Italy  ranked #164
Netherlands  ranked #137
New Zealand  ranked #1
Northern Ireland  ranked #6
Norway  ranked #2
Poland  -
Scotland  ranked #2
Spain  ranked #47
Sweden  ranked #7
Switzerland  ranked #75


Medium Voltage Power Cablemedium voltage power cable

Medium voltage power cables are designed for tough elements and a reliable power connection. Whether for temporary power or for permanent function, medium voltage power cable is often required for various applications, including power for instruments, ignition systems, and building structures.

What is Medium Voltage Cable?

What is medium voltage cable? Most simply, medium voltage cables carry a range of electrical current labeled as “medium.” While there is no general census on what definitively constitutes “medium voltage,” NEMA (National Electrical Manufacturers Association) has ratings for medium voltage cables between 600 V and 69 kV. See this link to NEMA’s website for detailed information.

From a contractor’s perspective, however, medium voltage wire is generally thought to range from 2,500 to 35,000 volts of electrical current carrying capacity. Medium voltage cables are used to provide power to a site requiring such a range of electricity.  Medium voltage power cables contain:

Each medium voltage wire component serves a specific function to ensure that the voltage carried by the cable safely conveys the necessary power to its application.

How is Medium Voltage Cable Used?

Medium voltage cables are used to provide power for specific environments and applications. Some applications for medium voltage power cable are:

Depending on the particular type of cable selected, medium voltage power cable can be installed in wet or dry locations, indoors or outdoors, and in raceways or underground ducts.

Types of Medium Voltage Cable

Medium voltage cables are required to provide power in a wide variety of applications. As a result, medium voltage wire requires various construction features, an array of sizes, and materials to safely conduct high voltages of electricity. Medium voltage wire’s construction features include various:

Each of the differences between specification selections is due to the specific needs of the application.

For additional information about choosing the appropriate medium voltage cable for your application refer to Okonite’s engineering handbook linked here.

The Importance of Insulation

The insulation of the cable provides strength and durability for the life of the MV cable.  Insulation is often the conductor’s first line of protection.

In partnership with Okonite, Colorado Wire and Cable provides MV cables with a superior insulation system. Utilizing EPR (Ethylene Propylene Rubber) in direct contact with semiconducting shields, Okonite’s EPR insulation offers arguably the best options for insulated medium voltage power cable in the industry. For an in depth look at Okonite’s EPR insulation system take a peak at this article.

Non-shielded vs. Shielded Medium Voltage Cable

Generally shielded cables provide superior safety, noise reduction, and protection for the cable. For safety purposes, in 2005 the NEC made a change to their regulations concerning non-shielded medium voltage cables. Consequently, any medium voltage cable, with limited exceptions, must have a shield.  See this article outlining the changes to shielding for medium voltage wire.

Medium Voltage Cable Durability

Medium voltage power cable is the most durable power cable for the widest array of applications in commercial, industrial and utility industries. Due to the high voltage stress on the cable, it is essential that the cable is equipped with proper insulation, shielding, and jacketing to both contain the current and protect the cable from the particularities of the environment.


December 16, 2008

Superplumes May Have Shaped The Continents

The giant plumes -- or "superpiles" as Panero calls them -- rise from the bottom of Earth's mantle, just above our planet's core. Each is larger than the continental United States. And each is surrounded by a wall of plates from Earth's crust that have sunk into the mantle.

Computer models have connected the piles to the sunken former plates, but it's currently unclear which one spawned the other, Panero said. Plates sink into the mantle as part of the normal processes that shape the continents. But which came first, the piles or the plates, the researchers simply do not know.

"Do these superpiles organize plate motions, or do plate motions organize the superpiles? I don't know if it's truly a chicken-or-egg kind of question, but the locations of the two piles do seem to be related to where the continents are today, and where the last supercontinent would have been 200 million years ago," she said.

Scientists first proposed the existence of the superpiles more than a decade ago. Earthquakes offer an opportunity to study them, since they slow the seismic waves that pass through them. Scientists combine the seismic data with what they know about Earth's interior to create computer models and learn more.

"That's a problem," Panero said. "We know that the rest of the mantle is always moving. So why are the piles still there?"

But the presence of the superpiles and the location of subducted plates suggest that the two superpiles have likely remained fixed to the Earth's core while the rest of the mantle has churned around them for millions of years.

"Material that is more dense is going to sink to the base of the mantle," Panero said. "It would normally spread out at that point, but in this case we have subducting plates that are coming down from above and keeping the piles contained."

This work was funded by the National Science Foundation.

On the Net:


Foundations of UX: Logic and Content

with Morten Rand-Hendriksen
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Foundations of UX: Logic and Content
Video duration: 0s 1h 45m Beginner

Foundations of UX: Logic and Content looks at how designers, developers, and content creators can use the ancient art of logic and reasoning to improve user experiences and facilitate communication. Morten Rand-Hendriksen looks at the principles of logic, how computer logic and human logic differ, and how these differences can be used to improve communication.

The core idea of logic is to create a system in which communication is clear, precise, and unambiguous, which is (or at least should be) the goal of any website or other communication.

Topics include:
  • How humans communicate
  • Comparing human and computer communication
  • Speaking logically
  • Using logical arguments
  • Understanding the limits of computer logic
  • Formatting information for humans
  • Communicating with logic

- Hi, I'm Morten Rand-Hendriksen and welcome to Foundations of UX Logic and Content. In this course, we're exploring user experience and content creation from a philosophical perspective, with the goal of answering a surprisingly complex question. How do we communicate clearly? Communication is the cornerstone of our civilization and the very essence of the modern information age. So it's surprising to realize we are not the great communicators we imagine ourselves to be.

Misunderstandings, misinterpretations, and flat out miscommunication is as commonplace in our digital meeting places as they are in the real world. With this as our backdrop, we're going to explore logic and how we can use it to create better and more understandable user experiences. In design, as well as content creation. We'll start off by looking at how logic fits into our everyday lives. We'll then look at the principles of logic and get a clear picture of how it works.

We'll look at computer logic and human logic and identify where each of them excel. And finally, we'll explore how to use logic to create better user experiences through better communication. If you've encountered logic before, you may be coming to this course with some trepidation. Fret not, my friend. I am here to make logic both fun and interesting. But more importantly, I'm here to show you how logic can make you a better communicator.

So let's take the next logical step and get cracking with Foundations of UX Logic and Content.

please wait ...


David Sweetnam

Meniscal injuries are one of the commonest problems that I see as an orthopaedic surgeon specialising in knee injuries/problems. The meniscus is perhaps more commonly referred to as the knee ‘cartilage’.

We have all heard of professional sportsmen and women sustaining ‘cartilage injuries’, so it may come as a surprise to know that the majority of my patients tear their cartilage undertaking relatively common day-to-day activities.

For this reason, it often doesn’t occur to the patient or their family doctor that they may have torn a cartilage.

A significant twisting injury sustained whilst playing football or skiing may result in a tear but the day to day action of getting up from sitting on the floor can produce the same result, especially in the older age group. In orthopaedic terms, the phrase “older age group” sadly refers to patients over 30! After this age, the cartilage has already started to turn from a very resilient, tough construct to a more brittle one. It is for this reason that a simple twisting injury can cause a small split within the cartilage.

The meniscus has a very limited capacity to heal by itself because it doesn’t have a blood supply. This means that symptoms from a torn cartilage will often persist long after one would expect other injuries to have healed, leading the patient to seek specialist advice for a pain that doesn’t seem to be “getting better”.

What is the function of the knee cartilages (the knee menisci)?

The three main functions of the menisci are:

   - To act as shock absorbers
   - To provide stability
   - Improve lubrication within the knee

How is a torn cartilage (meniscal tear) diagnosed?

Whilst the story of a classical sporting injury is relatively self-evident, where there has been no specific history of trauma to the knee that you can recall, making the diagnosis can be much more challenging.

Listening to your history is, however, usually very helpful.

* Occasional sharp stabbing pain on either the inside or outside of the knee

* Limitation in the range of motion, particularly deep bending

i.e. kneeling/squatting

* Difficulty climbing stairs due to pain

* Pain on exercising

* Catching/clicking sensation

* A feeling of ‘giving way’/instability

- Fluid present in the knee, known as an “ effusion”

- Marked pain on direct compression of the meniscus along the joint line

- Discomfort when squatting

How can we treat a meniscal tear?

Moreover, when a patient with a known tear has other conditions affecting the knee such as arthritis, surgery is less likely to be successful and this should influence the decision to proceed.

Frequently Asked Questions

How long will I stay in hospital for?

As your operation will be performed in the afternoon, you will be required to stay in hospital for one night.

Will I have stitches?

Yes, you will have a few small sutures, which will be removed in Mr Sweetnam’s clinic after 2 weeks.

How long do I need off work?

You will need to take approximately 4 – 5 days off work.

Will I need crutches?

Can I drive?

Yes, after 48 hours.

Do I need physiotherapy?

You will be given an exercise sheet by the physiotherapists on the ward, you will then need to see a physiotherapist at least once a week for the first few weeks. If you don’t have a physiotherapist, please call Mr Sweetnam’s secretary on 0207 483 5449 who will recommend one in your area.

MENISCAL SURGERY (Arthroscopic partial meniscectomy)

The patient will need to:

- Starve for at least six hours prior to surgery.
- To arrive by midday for afternoon surgery

Some patients leave the evening of the operation whilst others stay until the following morning.

After surgery

The knee is dressed with a woollen bandage overnight and ice should be applied to reduce any swelling the next morning.

You will be patient is encouraged to walk almost immediately the next day, but only for short periods initially.

Any pain is normally controlled with a combination of anti-inflammatory drugs and painkillers . Physiotherapy should start within a few days.

Generally, full recovery takes about six weeks, but most patients can return to work within the first week. However, attempting to do too much to begin with, in my view, can often be a bad thing, irritating the sensitive remnant of the meniscus. It is very important for the knee to be given appropriate care and respect in the early stages.

A rehabilitation   solution tailored to your work commitments


Sacred Texts  Judaism  Index  Previous  Next

Was sich nie und nirgends hat begeben, das allein veraltet nie.

Men craved entertainment in later times as well as in the earlier, only instead of resorting for its subject-matter to what happened under their eyes, they drew from the fountain-head of the past. The events in the ancient history of Israel, which was not only studied, but lived over again daily, stimulated the desire to criticize it. The religious reflections upon nature laid down in the myths of the people, the fairy tales, which have the sole object of pleasing, and the legends, which are the people's verdict upon history--all these were welded into one product. The fancy of the Jewish people was engaged by the past reflected in the Bible, and all its creations wear a Biblical hue for this reason. This explains the peculiar form of the Haggadah.

But what is spontaneously brought forth by the people is often preserved only in the form impressed upon it by the feeling and the thought of the poet, or by the speculations of the learned. Also Jewish legends have rarely been transmitted in their original shape. They have been perpetuated in the form of Midrash, that is, Scriptural exegesis. The teachers of the Haggadah, called Rabbanan d'Aggadta in the Talmud, were no folklorists, from whom a faithful reproduction of legendary material may be expected. Primarily they were homilists, who used legends for didactic purposes, and their main object was to establish a close connection between the Scripture and the creations of the popular fancy, to give the latter a firm basis and secure a long term of life for them.

One of the most important tasks of the modern investigation of the Haggadah is to make a clean separation between the original elements and the later learned additions. Hardly a beginning has been made in this direction. But as long as the task of distinguishing them has not been accomplished, it is impossible to write out the Biblical legends of the Jews without including the supplemental work of scholars in the products of the popular fancy.

In the present work, "The Legends of the Jews," I have made the first attempt to gather from the original sources all Jewish legends, in so far as they refer to Biblical personages and events, and reproduce them with the greatest attainable completeness and accuracy. I use the expression Jewish, rather than Rabbinic, because the sources from which I have levied contributions are not limited to the Rabbinic literature. As I expect to take occasion elsewhere to enter into a description of the sources in detail, the following data must suffice for the present.

The works of the Talmudic Midrashic literature are of the first importance. Covering the period from the second to the fourteenth century, they contain the major part of the Jewish legendary material. Akin to this in content if not always in form is that derived from the Targumim, of which the oldest versions were produced not earlier than the fourth century, and the most recent not later than the tenth. The Midrashic literature has been preserved only in fragmentary form. Many Haggadot not found in our existing collections are quoted by the authors of the Middle Ages. Accordingly, a not inconsiderable number of the legends here printed are taken from medieval Bible commentators and homilists. I was fortunate in being able to avail myself also of fragments of Midrashim of which only manuscript copies are extant.

The works of the older Kabbalah are likewise treasuries of quotations from lost Midrashim, and it was among the Kabbalists, and later among the Hasidim, that new legends arose. The literatures produced in these two circles are therefore of great importance for the present purpose.

Furthermore, Jewish legends can be culled not from the writings of the Synagogue alone; they appear also in those of the Church. Certain Jewish works repudiated by the Synagogue were accepted and mothered by the Church. This is the literature usually denominated apocryphal-pseudepigraphic. From the point of view of legends, the apocryphal books are of subordinate importance, while the pseudepigrapha are of fundamental value. Even quantitatively the latter are an imposing mass. Besides the Greek writings of the Hellenist Jews, they contain Latin, Syrian, Ethiopic, Aramean, Arabic, Persian, and Old Slavic products translated directly or indirectly from Jewish works of Palestinian or Hellenistic origin. The use of these pseudepigrapha requires great caution. Nearly all of them are embellished with Christian interpolations, and in some cases the inserted portions have choked the original form so completely that it is impossible to determine at first sight whether a Jewish or a Christian legend is under examination. I believe, however, that the pseudepigraphic material made use of by me is Jewish beyond the cavil of a doubt, and therefore it could not have been left out of account in a work like the present.

However, in the appreciation of Jewish Legends, it is the Rabbinic writers that should form the point of departure, and not the pseudepigrapha. The former represent the main stream of Jewish thought and feeling, the latter only an undercurrent. If the Synagogue cast out the pseudepigrapha, and the Church adopted them with a great show of favor, these respective attitudes were not determined arbitrarily or by chance. The pseudepigrapha originated in circles that harbored the germs from which Christianity developed later on. The Church could thus appropriate them as her own with just reason.

In the use of some of the apocryphal and pseudepigraphic writings, I found it expedient to quote the English translations of them made by others, in so far as they could be brought into accord with the general style of the book, for which purpose I permitted myself the liberty of slight verbal changes. In particulars, I was guided, naturally, by my own conception of the subject, which the Notes justify in detail.

The luxuriant abundance of the material to be presented made it impossible to give a verbal rendition of each legend. This would have required more than three times the space at my disposal. I can therefore claim completeness for my work only as to content. In form it had to suffer curtailment. When several conflicting versions of the same legend existed, I gave only one in the text, reserving the other one, or the several others, for the Notes, or, when practicable, they were fused into one typical legend, the component parts of which are analyzed in the Notes. In other instances I resorted to the expedient of citing one version in one place and the others in other appropriate places, in furtherance of my aim, to give a smooth presentation of the matter, with as few interruptions to the course of the narrative as possible. For this reason I avoided such transitional phrases as "Some say," "It has been maintained," etc. That my method sometimes separates things that belong together cannot be considered a grave disadvantage, as the Index at the end of the work will present a logical rearrangement of the material for the benefit of the interested student. I also did not hesitate to treat of the same personage in different chapters, as, for instance, many of the legends bearing upon Jacob, those connected with the latter years of the Patriarch, do not appear in the chapter bearing his name, but will be found in the sections devoted to Joseph, for the reason that once the son steps upon the scene, he becomes the central figure, to which the life and deeds of the father are subordinated. Again, in consideration of lack of space the Biblical narratives underlying the legends had to be omitted--surely not a serious omission in a subject with which widespread acquaintance may be presupposed as a matter of course.

As a third consequence of the amplitude of the material, it was thought advisable to divide it into several volumes. The references, the explanations of the sources used, and the interpretations given, and, especially, numerous emendations of the text of the Midrashim and the pseudepigrapha, which determined my conception of the passages so emended, will be found in the last volume, the fourth, which will contain also an Introduction to the History of Jewish Legends, a number of Excursuses, and the Index.

As the first three volumes are in the hands of the printer almost in their entirety, I venture to express the hope that the whole work will appear within measurable time, the parts following each other at short intervals.

NEW YORK, March 24, 1909

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Sound Waves

A wave of sound can be considered as a disturbance that travels through some material called a medium, transporting energy from one location to another. (Henderson) Such waves that seem to be hooked onto one another in a straight line are characterized as mechanical waves. When the first particle is disturbed it then moves the second particle on the line because they are hooked together and touching. Once the second particle starts moving, the third will be disturbed by the second particle's movement and the fourth particle will be disturbed by the third particle's movement and so on. The vibration will be passed on consecutively and the energy that was first introduced in the first particle will move on and on from particle to particle in that medium.

These mechanical waves can best be described as producing longitudinal waves. In a longitudinal wave, the medium would most commonly be the surrounding air particles that vibrate toward a certain direction. The individual particles of the medium will always move in a direction that is parallel to the direction that the energy is being applied. (Kriz) For instance, if someone is talking to another person, the sound waves produced by the vocal chords will move in a direction in which the person is faced. The waves will

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