1.1. Common carp (Cyprinus carpio) exposed to experimental temperatures of 12, 18, 24, 30 or 36°C for a 4-week period were used to investigate the effect of temperature acclimation on the frequency of opercular movement (FOM), growth and cytochrome c oxidase (CCO) activity in heart, liver and muscle.
2.2. An exponential relationship between FOM and temperature after the first week (1010 =1.76) disappeared after the second week.
3.3. The initially high FOM at temperatures of 30 or 36°C and the low FOM at 18 or 12°C changed over 4 weeks to approach the FOM of fish at 24°C.
4.4. This change in the relationship of FOM to temperature from highly dependent to independent appeared to be thermal compensation.
5.5. Heart and liver CCO activities were significantly affected by temperature, with the lowest activity at the approximate optimum temperature for growth, 24°C.
6.6. Highest CCO activities for heart and liver occurred at both the highest and lowest temperatures.
7.7. Among the three tissues, heart CCO activity was generally the highest and most affected by acclimation temperature.
8.8. Muscle tissue had the lowest CCO activity and was unaffected by temperature.
9.9. The high CCO activity at a cold acclimation of temperature 12°C was probably due to thermal compensation and the high activity at 36°C may have been a result of thermal stress.
1.1. A total of 541 pigeons from 3 populations was tested for the ability of nocturnal homing over increasing distances from 1 to 33 km.
2.2. Nocturnal homing over 20 km was an individual characteristic found only in a fraction of pigeons in a loft (30–35%). Its expression was not affected by variables influencing diurnal homing performance such as age, experience and breeding status.
3.3. This particular ability is likely to reflect superior navigational abilities related to non-visual orientation mechanisms.
4.4. The ability for nocturnal homing is probably genetically dependent: offspring from good nocturnal homers performed significantly better than offspring from poor homers.
1.1. The weight and energy content of sloughed skins of 92 individual snakes of 22 different species in three families were measured.
2.2. Weight and total energy content of shed skins were highly correlated with body weight.
3.3. The heat of combustion (kJ/g) of sloughed skins varied significantly among families and was higher in species having unkeeled scales than in those with keeled scales.
4.4. The presence of keels significantly affected weight of skins, even when skin weight is adjusted for covariance with body weight.
5.5. Neither body weight nor ambient temperature significantly affected the heat of combustion of sloughed skins.
6.6. The energy content of shed skin, expressed as a proportion of daily metabolism, decreased with ambient temperature, but the effect is minimized in large snakes.
7.7. Small snakes expended relatively less energy in sloughed skins than large snakes when the expenditure is expressed in terms of total daily metabolized energy.
1.1. Brain trehalase specific activity and trehalosemia were measured during the end of the developmental life cycle in non-diapausing and diapausing insects.
2.2. During non-diapausing development, trehalosemia reached maximum values at the beginning of pupal life. Then a constant decrease was observed up to the end of adult life.
3.3. The specific activity of brain trehalase was maximum when the insects were in active feeding periods, minimum activity appearing during moulting phases.
4.4. During diapausing development, trehalosemia was very high at the beginning of pupal life, particularly when insects were exposed to wintering conditions.
5.5. When diapause was broken, trehalosemia fell, announcing adult emergence.
6.6. Brain trehalase activity showed the same qualitative variations as in non-diapausing larvae, but with rather lower values.
7.7. During pupal life, brain trehalase activity decreased markedly during the long period necessary to obtain diapause breakdown.
8.8. Wintering conditions allow a progressive increase of brain trehalase activity, which preceded the fall of trehalosemia.
1.1. Ependymins are unique, highly divergent secretory proteins of the fish endomeninx. Thus far, no homologous sequences have been characterized in mammals.
2.2. Soluble ependymins are the predominant constituents of the cerebrospinal fluid of many teleost fish. A bound form of these glycoproteins is associated with the extracellular matrix probably with collagen fibrils. The latter may be the functional form of ependymins.
3.3. Ependymins bind Ca2+ via N-linked sialic acid residues leading to a conformational transition.
4.4. The molecular function of ependymins seems to be related to cell contact phenomena involving the extracellular matrix. For example, adhesive or anti-adhesive interactions may possibly influence ingrowing axons.
1.1. Communication is so essential to the living state at all its different levels of organization, from the cell organelle to the population, that in my opinion life could be defined as follows: Death ensues when the ability to communicate at the highest level of organization of the biological system under consideration is irreversibly lost.
2.2. The most primitive means of communication in the first cell which appeared on earth may have been ionic/electrical in nature. In the course of Evolution, a variety of additional means of communication have been generated.
3.3. Communication by whatever means requires gradients together with energy acquired from the environment.
4.4. “Life” might not have originated earlier than the moment that the first ionic gradient was actively established over the limiting membrane of the first cell. It may not be excluded that the ability to drive an ionic flux through itself, this implying polarity, was a second essential prerequisite for the living state to arise.
5.5. The formation of the primitive, polarized and order bringing cytoskeleton may have been as important as that of nucleic acids for the living state to arise and to acquire its full asset of means of communication.
6.6. “Life” may have originated many times in the primordial conditions before an ionically/electrically compartmentalized and polarized aggregate finally achieved orderly division and multiplication. Only then did the long term life traits for perpetuating a population and for generating diversity come into play.
7.7. If the proposed definition is correct, it follows that the term “life” implies flexibility because the ability to communicate depends on the steepness and the nature of the gradients: “life” presents itself in many forms and gradations.
8.8. The definition given under 1. or, more practically, “life: the ability to communicate” may bring more unity in all the different meanings which the different disciplines studying “life” intuitively attribute to their study object.
1.1. Plasma prolactin levels did not differ significantly between groups of birds collected at different times during the first year of life.
2.2. In adult males and females, highest plasma prolactin concentrations were evident in June (20.7 ± 7.8 and 20.4 ± 4.4 ng/ml respectively), probably associated with the incubation of eggs and rearing of young in the nest, whereas plasma prolactin levels in adult males and females collected at other times of the year were relatively stable and did not differ significantly between groups.
3.3. With the exception of the adults sampled in June, the prolactin levels in the adults were in the same range as those in the embryo gosling and yearling Snow Geese.
4.4. The concentrations of fat in both mature and immature birds was not related to the plasma prolactin concentration; maximal concentrations of carcass fat were observed during the northerly migration whereas maximum concentrations of prolactin were observed at the end of incubation when fat deposits were depleted.
This paper comments on: Low, B. S., Alexander, R. D., and Noonan, K.M. Human hips, breast, and buttocks: Is fat deceptive? Ethology and Sociobiology 8: 249-247, 1987. In it I argue that:
1.1. Sexual selection has probably not been the most important selection pressure on
2.female human body shape.
3.2. Male humans in different cultures find different aspects of the female body attractive
4.and therefore are unlikely to have exerted consistent directional sexual selection on
5.the female body.
6.3. Breast size is not correlated with lactation success.
7.4. Visible hip width is not correlated with parturition success.
8.5. Women would lower their fitness if they tried to deceive men about their internal
9.pelvic dimensions.
10.6. There are many alternative hypothesis to explain the existence of fat onwomen's
1.1. The present work deals with the effect of feeding hornets on moderate amounts of theophylline and allopurinol.
2.2. The median survival time of hornets fed on allopurinol was greater than that of hornets fed on theophylline, while that of a control group fed on sugar solution alone was between the two drug-fed groups.
3.3. The controlled-diet hornets, which were kept in the groups of 10, lived longer than hornets in groups of 20 or 40.
4.4. Those fed on theophylline usually did not eat proteins, niether did they build cells, lay eggs nor engage in any social activity. They behaved rather like queen hornets during the winter diapause.
5.5. Hornets fed on allopurinol built less cells and combs than did the controls. They were very aggressive, produced fewer eggs, attended less brood than did the controls and fed intensively on proteins (partly through cannibalism).
1.1. Homeostasis, or the maintenance of a constant internal environment, in invertebrate organisms decreases the dependence of these organisms on the vagaries of the external environment.
2.2. The evolution of physiological processes influencing homeostatic conditions begins with the organism being totally dependent upon the external environment, passing through a series of intermediate stages during which fluctuation in a given internal parameter occur, proceeding finally to a condition where the internal environment is constant and independent of the external environment.
3.3. A hypothetical scheme for the possible evolutionary pathway of osmotic and ionic regulation in aquatic invertebrates was developed in an attempt to follow the process of homeostasis in these organisms.
4.4. Primitive marine cells developed mechanisms to regulate the ionic composition of the cytoplasm probably in association with the need for volume regulation.
5.5. The development of a body wall separated an internal body fluid from the external sea-water and the ionic composition of the body fluids was initially maintained slightly different from that of the sea-water by essentially passive means.
6.6. The addition of excretory organs, which arose initially through an inpushing of the body wall, brought about the ability for osmoregulation.
7.7. Homeostatic mechanisms must be in place before an organism can move from one environment to another.
1.1. The chemistry and function of Dufour's gland secretions of two carpenter bees were studied.
2.2. Dufour's gland of Proxylocopa olivieri, a ground nesting bee, produces long chain hydrocarbons that are utilized to line its brood cells and are mixed with its bee bread.
3.3. Dufour's gland secretion of Xylocopa sulcatipes, on the other hand, is dominated by ethyl eicosanoate and ethyl docosanoate accompanied by the corresponding methyl esters and high boiling hydrocarbons.
4.4. This wood nesting bee apparently does not use Dufour's gland secretion to line its nest.
5.5. The relationship between the respective chemistry and function of Dufour's gland secretion and the nesting ecology of the two bees is discussed.
1.1. The role of the visceral nerve in mediating the changes in heart rate associated with different behavioral patterns was investigated in Megalobulimus sanctipauli.
2.2. The results of acute and chronic denervation experiments indicate that the visceral nerve has no excitatory or inhibitory tonic action on the heart of snails retracted into the shell, nor does it account for the increase in heart rate associated with the locomotion and feeding behaviors.
3.3. These changes in heart rate are, probably, indirect effects of increased activity such as an increase in venous return.
4.4. The visceral nerve is responsible for approximately 3/4 of the increase in heart rate associated with the first minute of extrusion.
5.5. The small increase in heart rate observed in denervated animals is probably caused by an increase in venous return generated by muscle activity that forces the head and food out of the shell.
1.1. Size and composition of sagittal otoliths from red drum, Sciaenops ocellatus (Sciaenidae), reared at various constant temperatures were compared with otoliths from wild-caught fish.
2.2. Uncoupling of otolith growth and somatic growth in laboratory-reared fish was evident in otolith length, area, volume, weight, density, and organic fraction.
3.3. Fish grown at low temperatures had significantly smaller and less dense otoliths having a greater organic content than fish of the same size grown at higher temperatures.
4.4. Changes in inorganic elements were poorly related to temperature in laboratory-reared fish.
5.5. The effect of temperature on otolith elemental composition was small relative to the effects of age and its associated physiological changes.
1.1. The effect of prepuberal gonadectomy of Sprague-Dawley/NIH/HAN rats on cytoplasmic 17β-hydroxysteroid dehydrogenase was examined on day 30, 45, 60, 75, 90 and 105 of life.
2.2. The activity in male rats was not significantly affected by gonadectomy, whereas the activity in females showed an age-dependent oestrogen dependency.
3.3. This age-dependent oestrogen dependency could also be demonstrated in 5α-dihydrotestosterone treated intact females.
4.4. Cytoplasmic 17β-hydroxysteroid dehydrogenase activity of female Chbb:THOM rats also showed an age-dependent oestrogen dependency, whereas the enzyme activity of male rats of this strain showed a distinct androgen dependency absent in Sprague-Dawley/NIH/HAN rats.
5.5. On the basis of previous investigations it is concluded that the androgen dependency of the enzyme activity of male Chbb:THOM rats has been bred into this strain in the period 1974–1977.
