bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anatomical and functional aspects of the nasal mucosal and ophthalmic retia of phocid seals
Authors: FOLKOW L. P. , BLIX A. S. , EIDE T. J. 
Published: March 2009

The anatomy of the nasal conchae with their mucosal vasculature, as well as that of the ophthalmic retia mirabile of grey (Halichoerus grypus) and harp (Phoca groenlandica) seals were investigated by dissection, injection and histological techniques.The highly convoluted nasal conchae had a surface area of approximately 25 cm2.kgw‐1, usually with an air space of less than 1.0 mm between the conchal lamellae. A longitudinally oriented, extensive conchal mucosal rete is supplied caudally by the sphenopalatine artery. A plexus of retial veins runs adjacent to, and in close contact with, the retial arteries. The venous plexus may be drained caudally, primarily by the sphenopalatine/descending palatine veins, and/or rostrally, by the dorsal nasal vein. Microscopical examination revealed that the arterial and venous retial vessels communicate mainly through capillaries, but some arterio‐venous anastomoses were detected in the alar fold region. The nasal conchae provide the means for efficient conservation of heat and water by nasal temporal counter‐current heat exchange. This is due to a thermal gradient, which will exist along the nasal mucosa, as long as the animal is breathing air colder than body temperature. We suggest that the blood usually runs in a counter‐current fashion in the conchal mucosal retia, whereby the temperature gradient along the mucosa may be maintained. Moreover, the steepness of this gradient may be altered by changes in nasal mucosal blood flow so as to control accurately the extent of respiratory heat and water loss. Both species possess a complex ophthalmic rete mirabile. Arterial supply to the rete is by the external ophthalmic artery, while venous drainage may occur by way of several anastomosing veins. The vascular arrangement suggests that counter‐current heat exchange may take place between arterial and venous blood. Such exchange would allow the temperature of the eye to be maintained at a lower level than that of the ophthalmic arterial blood and, hence, reduce heat loss from the large pinniped eyes.
The distribution of faeces by the Spanish lynx (Felis pardina)
Authors: ROBINSON I. H. , DELIBES M. 
Published: March 2009

SummaryThe distribution of faeces of the Spanish lynx was observed in the Biological Reserve of Dofiana during October 1985. Faeces were non‐randomly distributed on tracks through the vegetation, and occurred more frequently than expected beside intersections of deer trails with the tracks.A computer simulation showed that a randomly moving lynx was more likely to encounter faeces when they occurred at intersection points than when they occurred randomly on tracks.I.R. would like to thank Dr J. Castroviejo for permission to work in the Biological Reserve of Dofiana. Thanks are also due to R. Laffitte for help in the field, and to A. Blom for discussions about the work. Dr M. L. Gorman provided useful comments on earlier drafts of this manuscript, as did Dr G. J. Pierce who also gave advice about the computer simulations. The investigation was supported by a grant to I.R. from the Mammal Society and the University of Aberdeen's Skene and Cran bequest funds, and by project No. 944 of CSIC‐CAICYT (Spain).
The influence of riparian vegetation on macroinvertebrate community structure in four Hong Kong streams
Authors: DUDGEON DAVID 
Published: March 2009

The benthic macroinvertebrate communities of four Hong Kong streams with similar water chemistry but differing riparian conditions were investigated. Differences in chlorophylls and detritus standing stocks reflected the degree of shading by riparian vegetation; Tai Po Kau Forest Stream (TPKFS) and Bride's Pool (BP) had an allochthonous food base while autochthonous energy sources were relatively more important in Lam Tsuen River (LTR) and Pui O Stream (POS). The macrobenthos was dominated by aquatic insects and morphospecies richness (excluding Chironomidac) ranged from 70 (POS) to 94 (TPKFS). Differences in total macroinvertebrate abundance across sites were not related to chlorophylls or detritus.Highly significant differences in the morphospecies comprising the most numerous taxa at each site were observed, and TPKS and BP were more similar to each other than to the LTR‐POS pair with respect to top‐ranked taxa. Intraspecific comparisons of the abundance of these taxa revealed significant differences for 23 out of 30 morphospecies. Multiple regression of the abundance of key morphospecies against independent variables (chlorophylls a, b and c, total chlorophyll and detritus) yielded significant best‐fit models for all taxa showing intersite differences in abundance. These data can be interpreted as reflecting the influence of riparian vegetation on stream community structure via an effect on food supply. The results were discussed with reference to the applicability of the River Continuum Concept in the tropics.
Evidence for echolocation in the common shrew, Sorex araneus
Authors: FORSMAN K. A. , MALMQUIST M. G. 
Published: March 2009

In this laboratory experiment it is shown that, like four North American soricid shrew species, the European common shrew Sorex araneus L. is able to use echolocation to identify open and closed tubes at a distance of 200 mm.Three common shrews captured in Sweden were used for the experiments, which were carried out in darkness and within a sound‐proof box. The experimental set‐up eliminated orientation using sight, sound or scent from outside the experimental cage. Echolocation calls consisted of broadband ultrasonic clicks at low sound pressure. These were recorded using an ultrasound detector.The ecological significance of echolocation in shrews is discussed. It is proposed that common shrews use echolocation to locate protective cover, thus minimizing the risk to be taken by, e.g. owls.Echolocation may also be used for detecting obstacles in subterranean tunnels. Hence, echolocation could be of certain importance when abandoned burrows in the periphery of the tunnel system are restored during periods of increasing population densities. Since density peaks in most populations occur regularly each summer, and may reach extreme magnitudes in cyclic populations, the ecological significance of echolocation in shrews may be considerabl.
Succinic dehydrogenase activity in the epidermis ofNatrix piscator during its sloughing cycle
Authors: Mittal A. K. , Singh J. P. N. , Singh S. K. 
Published: March 2009

Succinic dehydrogenase activity, in the epidermis of Nairix piscutor in different stages of sloughing cycle, has been localized using a nitro‐BT technique with appropriate controls. The staining properties of different layers in scale epidermis are similar to the corresponding layers in hinge epidermis.In the stratum germinativum, the layers of undifferentiated epidermal cells in all stages of the sloughing cycle, and in the lacunar tissue of Stages 3,4 and 5, a positive though weak reaction for SDH activity reflects the active metabolic state of the cells in these layers. Loss of SDH activity in Stage 6 indicates an inactive metabolic state of the lacunar tissue cells, corresponding with their disintegration owing to the cessation of nutrients as a result of keratinization of cells in the underlying layers.The Oberhautchen, mesos and alpha layers in all Stages, and the clear layer cells in Stages 5 and 6 (outer epidermal generation), the presumptive Oberhautchen, presumptive mesos layer and presumptive alpha layer in all stages of their differentiation, and the presumptive beta layer in Stages 3 and 4 (inner epidermal generation) all stain purple with nitro‐BT technique even in sections incubated in the medium without the substrate‐succinate. The reaction is inhibited by prior treatment with 0.1 M N‐ethyl maleimide blocking protein‐bound ‐SH groups. This suggests that the reaction is due to the presence of protein‐bound ‐SH groups in these sites. The reduced intensity of reaction in the mature beta layer of the outer epidermal generation, and in the presumptive beta layer in Stages 5 and 6 of the inner epidermal generation, is due to simultaneous loss of their content of ‐SH groups with maturation and keratinization.
Energy requirements of fat sand rats (Psammomys obesus) and their efficiency of utilization of the saltbush Atriplex halimus for maintenance
Authors: Degen A. Allan , Kam M. , Jurgrau Debbie 
Published: March 2009

The fat sand rat (Psammomys obesus; Gerbillinae), a diurnal gerbillid rodent, is herbivorous and able to thrive while consuming only the saltbush Atriplex halimus (Chenopodiaceae), a plant relatively low in energy content and high in ash and water. We measured the basal metabolic rate offat sand rats, their energy requirements in captivity when they were offered only A. halimus, and their efficiency of utilization of this diet for maintenance.Before consuming A. halimus leaves, the fat sand rats scraped off the surface layers with their teeth. This behavioural activity removed 6.4% to 8.5% of the dry matter of the leaf, but increased the gross energy and organic matter content of the leaf by only approximately 3.1%. Basal metabolic rate of the fat sand rats was 167.9 kJ.kg‐O 7s d‐′, approximately 57% of that expected for an eutherian mammal of its body mass, and energy requirements for maintenance, or average daily metabolic rate, were 498.7 kJ.kg‐0′7s d‐′, approximately 90% of that expected for a rodent of its body mass. Dry matter digestibility of the consumed A. halimus averaged 67% and apparent digestible energy and apparent metabolizable energy averaged 65.3% and 63.4% of the gross energy, respectively. The efficiency of utilization of A . halimus for maintenance energy (k,) by the fat sand rats was 0.32 and the heat increment of feeding (HIF) was 0.68. The k, of A. halimus appeared to be low compared to other feeds, and this characteristic plus its low energy value and high water content forced the fat sand rats to consume large quantities of forage for maintenance.It was concluded that although A. halimus has a low energy and high ash content, there are several advantages for fat sand rats consuming mainly this diet. Among them are: (1) it provides a more stable diet throughout the year than do seeds; (2) fat sand rats have no competition for this food resource from other rodents; and (3) their burrows are at the base of the
The chemosensory behaviour of Lithobius forficatus (Myriapoda: Chilopoda). 2. Bioassay and chemistry of the coxal pheromone
Authors: Littlewood P. M. H. 
Published: March 2009

The common brown centipede, Lithobius jorJcatus (L.), releases a sex‐specific pheromone which emanates from distinctive cuticular openings on the coxae of the hind legs‐the coxal pores (Littlewood & Blower, 1987). The pheromone can be isolated from tissue extracts of the coxal organs (surrounding the coxal pores) and from substrata which have been 'marked by male or female L. forjcatus and presented to centipedes in the form of a behavioural bio‐assay.In this paper, further evidence is presented for a centipede pheromone, the chemical components of male and female secretions are separated using Gas Layer Chromatography (GLC), a qualitative chemical analysis is described and the nature of the pheromone is discussed.
The vascularization of the choroid plexus of the lateral ventricle of the turtle Pseudemys scripta elegans (Reptilia)
Authors: Weiger T. , Lametschwandtner A. 
Published: March 2009

The vascularization of the choroid plexus of the lateral ventricle of the turtle (Pseudemys scripta elegans) has been studied by means of vascular corrosion casts and transmission electron microscopy (TEM). A single arterial supply via the choroidal artery and a two‐fold venous drainage was found. By its form the plexus was subdivided into two parts: the body, and numerous villi projecting out of the body. The body consists of large convoluted arteries and veins which are covered by a network of vessels always greater than 15 μm in diameter. The villi are composed of a head consisting of vessels with a diameter of 16–50 μm and a stalk represented by one arteriole and one or two veins, which unite at the base of the stalk. An arteriovenous shunt occurs occasionally at the base of the stalk. By their angioarchitecture, six types of villi can be discerned: simple, club‐shaped, flat, wrinkled, glomus‐like and basket‐like villi. Garland vessels were present around arteries only. In ultrathin sections the vessels of the head of a villus possess a thin endothelium with tentacle‐like flaps which protrude into the lumen and many pinocytotic vesicles. These vessels were surrounded by a very fragmentary basement membrane and a dense layer of collagen fibrils.It is suggested that the different areas in the plexus, i.e. the various villi and the body, represent areas with different physiological functions
Overwintering strategies of the badger, Meles meles, at 57 °N
Authors: Fowler P. A. , Racey P. A. 
Published: March 2009

Over two eight‐month periods (October/November‐May) during successive winters (1983/4 and 1984/5), the body temperatures and activity patterns of captive badgers, Meles meles, living under semi‐natural conditions, were studied at 57 d̀N in Scotland. Temperature‐sensitive radio transmitters and automated telemetry systems provided long‐term records of body temperatures and times badgers were absent from an artificial sett.Badger body temperatures of 28–34 d̀C, significantly below euthermic levels, were recorded between October/November and March each winter, with differences between mean daily maxima and minima varying from 1.6 to 8.9 d̀C. This was associated with a reduction, by up to 90%, in the time that the badgers spent outside their sett in mid‐winter. Body temperatures did not show circadian cyclicity, but from February onwards most locomotor activity occurred between 22:00 and 02:00 GMT. The extent to which activity was concentrated around midnight increased with decreasing night length in spring.The body temperatures of one female badger fell to a nadir of 28 d̀C immediately prior to ovo‐implantation. During post‐implantation gestation, the body temperature of this female rose steadily, but had reached only 34.6 d̀C at parturition.Photoperiod correlated closely with seasonal changes in body temperatures and activity levels, and is suggested as the primary synchronizer of seasonal activity and body temperature cycles. Other environmental variables, particularly ambient temperature and snow‐cover, appeared to act as modulating influences on these cycles.It is postulated that during the winter, when climatic conditions are responsible for a shortage of food and an increase in heat loss, winter lethargy is an adaptation which enables the European badger to maintain energy balance. Reduced activity and confinement within sheltered setts, together with reduced body temperatures, enable the badgers to rely heavily on energy stored in adipose tissue during the autumn.
Reproductive biology of Nilgiri tahr, Hemitragus hylocrius (Mammalia: Bovidae)
Authors: Rice Clifford G. 
Published: March 2009

The reproductive biology of Nilgiri tahr (Hemitragus hylocrius) was studied in Eravikulam National Park, Kerala, India from August 1979 to September 1981.The rutting season occurred during the monsoon (July and August) and the main birth season was January to mid‐February. Gestation was estimated at 179 days.Three females which lost their first young in 1981 conceived 18 to 21 days post‐partum. One female conceived of her second young while the first was 15 days old. The remainder of the individually identified females gave birth to one young (n=40) or none (n=4).Infant mortality was highest during the first two weeks after birth. Young born during the monsoon also had a high mortality rate (0.50/week).Oestrus during the rut was discontinuous in 1980 and 1981. Periods of frequent oestrus corresponded with periods of low rainfall with a mean lag time of 4.9 days.The ultimate factor determining the birth season in Nilgiri tahr appears to be weather. The main birth season is timed so as to minimize thermal stress.Several proximal factors may be important in stimulating reproductive activity. These include photoperiod, temperature, the presence of males in mixed groups, and nutrition. The photoperiod response is unusual in that Nilgiri thar evidently respond to the abrupt decrease in apparent day length associated with the onset of the monsoon.The inverse correlation of rainfall and oestrous activity may have been effected through the sudden decrease in thermal stress on the females or heavy rainfall (5.7 cm/day) masking pheromonal stimulation.The pattern of lactation anoestrus observed in Nilgiri tahr approximates results obtained from some studies of domestic Caprini.Nilgiri tahr females are presumably able to increase their lifetime reproduction by giving birth twice in one year. However, this strategy seemed counterproductive in 1981 as survival was low for second offspring.
Activity and thermoregulation of the snake Natrix maura. 2. A synoptic model of thermal biolgy and the physiological ecology of performance
Authors: Hailey A. , Davies P. M. C. 
Published: March 2009

Biophysical, physiological and behavioral approaches to reptilian thermal biology have been combined in a synoptic model, using data derived from a study of the snake Natrix maura in a Spanish river and in the laboratory. The model investigates the relations between the costs and benefits of physiological performance, body temperature, the season of activity, and the thermal benefits of physiological performance, body temperature, the season of activity, and the thermal environment. The performance variale chosen was aerobic metabolism. The cost associated with high aerobic metabolism at low body temperatures is the energy requirement for maintenance; the benefit is an increased activity season.The cost of maintenance was more sensitive to differences in the level and temperature sensitivity of metabolism than was the benefit of the time for activity. The pattern of performance and body temperature obesrved in N. maura was close to that predicted for maximum efficiency, in terms of the activity season produced per unit of annual maintenance cost. It is noted, however, that animals will be selected for net benefit, and not for efficiency as such.A definition of fitness for the study of the physiological ecology of performance was developed, to take account of the level of performance available during activity, and of selection for net benefit. This definition is: the energy intake above maintenance costs x the probability of survival. It is related to general ecological fitness by considering lifetime strategies of survival and reproduction, and the energy equivalence of offspring. These strategies are the subject of the physiological ecology of allocation, which is thus complementary to that of performance.The following are also discussed: the role of performance in interactions with predators and prey; other possible evolutionary determinants of body temperature; the limitations of different approachs to thermal biology; suitable systems for further study.
Mathematical and biological intermediacy in bone shape. Fourier analysis of cervical and upper thoracic vertebrae in the mouse
Authors: O'Higgins P. , Johnson D. R. , McAndrew T. J. 
Published: March 2009

We have used Fourier transforms and discriminant analysis to look at the shapes of cervical and upper thoracic vertebrae from two pairs of mouse strains and biological intermediates (the F1s) between them. We have also constructed mathematically intermediate shapes and compared mathematical and biological intermediates.Mathematical and biological intermediates did not correspond in any of the 18 cases studied. We suggest that failure in correspondence is due to complex genetical and environmental factors acting on the F1 phenotype, and that multivariate shape inheritance may be modelled in a similar way to univariate inheritance. Both depend on a large number of genetic loci.
Life cycle, production, microdistribution and diet of the damselfly Euphaea decorata (Odonata: Euphaeidae) in a Hong Kong forest stream
Authors: DUDGEON DAVID 
Published: March 2009

Euphaea decorata in Tai Po Kau Forest Stream (Hong Kong) was univoltine. Most recruitment took place in summer, and larval growth proceeded throughout the year. Life‐cycles recorded in 1977–78 and 1978–79 were similar. Annual production estimates, using the removal‐summation, instantaneous growth and size‐frequency methods, were more similar for the 1978–79 generation (ranging from 158.7–174.7; mean 1671 mg dry wt m‐2) than for the 1977–78 generation (93.9‐173‐6; mean 131.7 mg dry wt m‐2). Mean biomass was similar for both generations (ranging from 33.5–33.9 mg dry wt m‐2), and mean P/B ratios were 3.9 1977–78) and 5.0 (1978–79). These are the first estimates of annual production by an Oriental stream insect.Larvae were most abundant at microsites in the middle of the stream. Multiple regression analysis indicated that substratum characteristics were a major determinant of microdistribution. Euphaea decorata apparently favoured poorly‐sorted sediments with highly peaked grain size‐frequency distributions, containing few fine particles.The carnivorous larvae showed ontogenetic changes in diet. Small individuals consumed mainly chironomid (Diptera) larvae; the diet expanded to include (successively) larvae of Ephemeroptera and Trichoptera as E. decorata grew. Seasonal changes in diet were also apparent, although larval diets during spring and summer were similar. There was also considerable overlap between autumn and winter diets. Ontogenetic influences upon prey consumed were not sufficient to account for the observed seasonal differences.
Enzymes in the epidermis of Natrix piscator during its sloughing cycle
Authors: SINGH J. P. N. , MlTTAL A. K. 
Published: March 2009

Acid phosphatase, non‐specific esterase, alkaline phosphatase, monoamine oxidase and true lipase activities, in the epidermis of Natrix piscator in different stages of the sloughing cycle, have been localized using various histochemical techniques.Different layers in scale epidermis have staining properties similar to corresponding layers in hinge epidermis.Acid phosphatase and non‐specific esterase activity in cell layers undergoing keratinization, and the lacunar tissue undergoing disintegration are associated with hydrolytic and catabolic wasting processes involving cell death. The activity of these enzymes in the clear layer is associated with the breaking down of the cementing substance resulting in the separation of clear layer from underlying tissue and facilitating the shedding of old slough.Alkaline phosphatase activity in the stratum germinativum and undifferentiated epidermal cells has been associated with cell proliferation and differentiation. The presence of alkaline phosphatase in the lacunar tissue and clear layer has been correlated with the synthesis of mucopolysaccharides in these layers.Monoamine oxidase and true lipase activity could not be located in the epidermis at any stage of the sloughing cycle.