bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the Genetic Determinants of Cardiovascular Disease Using Candidate Genes and Meta‐analysis of Association Studies
Authors: Casas Juan P. , Cooper Jackie , Miller George J. , Hingorani Aroon D. , Humphries Steve E. 
Published: March 2006

SummaryCoronary artery disease (CAD) has a polygenic basis, and identification of CAD susceptibility genes has the potential to aid the development of new treatments and enhance prediction of disease risk. Thus far, the strategy has firstly been to choose “candidate” genes coding for important “rate‐limiting” proteins in the homeostatic systems involved in maintaining cardiovascular health; secondly to identify common variants in these candidate genes; thirdly to carry out genotyping and statistical analysis using genetic association studies; and finally to test the functional effects of the identified variants in vitro and in vivo. However, lack of reproducibility of genetic association studies has led to uncertainty about the nature and number of genes involved. In part this is because many of the studies conducted have not been adequately powered to detect small risk effects, or to permit adequate exploration of gene‐gene or gene‐environment interactions in a robust manner. Spurious positive and negative associations due to type I and type II statistical errors are likely to co‐exist with real associations in the published literature. By utilising all available data to increase statistical power, meta‐analysis of genetic association studies is increasingly being used to identify genotypic risk with a greater degree of precision. Though potentially powerful, this approach may be prone to publication bias. Therefore, very large genetic association studies will also be required to identify risk genes for CAD. This review lays out the framework for the candidate gene approach for CAD and illustrates this with published results from a UK prospective study of 3000 middle‐aged men.
A survey of Cryptosporidium species in Skomer bank voles (Clethrionomys glareolus skomerensis)
Authors: Bull S. A. , Chalmers R. M. , Sturdee A. P. , Healing T. D. 
Published: February 2006

AbstractA survey of Skomer voles (Clethrionomys glareolus skomerensis) conducted in August of 1994 and 1995 discovered that 51% of live‐trapped animals were positive for Cryptosporidium species (Coccidia). Of the positive animals, 85% were shedding C. muris in their faeces, 5%C. parvum and 10% apparently both parasite species. On the U.K. mainland, the prevalence of Cryptosporidium in the bank vole (Clethrionomys glareolus) is a quarter of that on Skomer and the species normally found is C. parvum. Interest in C. parvum stems from the often severe diarrhoeal disease cryptosporidiosis which it can cause in humans and livestock. The parasite occupies the gastro‐intestinal tract and is transmitted between hosts by the faecal‐oral route. It has been suggested that wild rodents may be an important reservoir of infection by C. parvum for livestock. However, on Skomer island, C. muris, which is rarely found in livestock, is the dominant species infecting voles.
Static biting in lizards: functional morphology of the temporal ligaments
Authors: Herrel A. , Aerts P. , De Vree D. 
Published: February 2006

AbstractIn lizards, the basic lepidosaurian bauplan of the skull is modified by the reduction of one or more skull elements such as the lower temporal bar (e.g. iguanids), the upper temporal bar (e.g. varanids) and the postorbital bar (e.g. geckos). Skull modifications in Plocederma stellio, Uromastix acanthinurus, Corucia zebrata and Tiliqua scincoides are restricted to the reduction of the lower temporal arcade (the plesiomorph condition for lizards; i.e. possessing a ‘basic’ skull). In spite of the potential mobility (streptostyly) of the quadrate, none of these species shows streptostylic movements during the static power phase of biting. It is assumed that the temporal ligaments fulfil the role of the lower temporal arcade in stabilizing the quadrate. This function is supported by the results of mathematical simulations, which demonstrate that static biting loads the ligament in tension. Apparently, these basic lizard skulls show a shift of the attachment site of the temporal ligament from the quadrate to the lower jaw. This does not affect its quadrate‐stabilizing function. However, analyses of forces occurring in the quadratomandibular joint suggest that skull configurations with a jugomandibular ligament confine the possible orientations of the joint forces to a narrow range, more aligned with the quadrate. In this way, optimization of the joint morphology to resist loads imposed by biting might more easily be reached. This is assumed to be important for lizards with a robust skull built for forceful biting.
Persistence of passerine ectoparasites on the diederik cuckoo Chrysococcyx caprius
Authors: Lindholm Anna K. , Venter Gert J. , Ueckermann Edward A. 
Published: February 2006

AbstractUsing the African diederik cuckoo Chrysococcyx caprius and four sympatric passerine foster species in the subfamily Ploceinae, we show that nestling cuckoos are infested by feather lice and mites derived from the ectoparasite fauna typical of the foster species. Adult cuckoos had five species of lice and mites normally found on ploceines, which demonstrates that these ectoparasites are able to survive on foreign hosts. This is the first record of persistence of passerine ectoparasites on a cuckoo. Adult diederik cuckoos also harboured four species of mites and lice specific to cuckoos; since these were not detected on nestlings, cuckoo‐specific lice and mites apparently transfer to cuckoos after they leave the nest. Contrary to prediction, ectoparasites with a life cycle involving a permanent association with their host (feather mites and lice) were more likely to transfer to cuckoo nestlings than ectoparasites which spend part of their life cycle away from their host (haematophagous mites and phoretic skin mites). New host records are established for the lice genera Brueelia, Cuculoecus, Machaerilaemus, Myrsidea, Philopterus as well as for the mite species Microlichus americanus, Ornithonyssus bursa, Ornithocheyla megaphallos, Pellonyssus reedi, Pteronyssoides passeris, Pternonyssus glossifer, Trouessartia baupi, T. carpi, Xolalges plocei, X. scaurus and the mite genus Passeroptes.
WINNER TAKES ALL? SOCIAL CONTROL OF REPRODUCTION IN CO‐OPERATIVE BREEDERS
Authors: Cotgreave Peter 
Published: February 2006

AbstractWhy would a female animal forego her opportunity to pass on her own genes into the next generation and, instead, help to raise somebody else's young? One potential answer comes in the form of kin‐selection. If the youngsters she helps to raise are related to her, then they will share some of her genes, and it may pay to invest in them rather than attempting to breed herself.
Evidence for female‐biased dispersal in North American porcupines (Erethizon dorsatum)
Authors: Sweitzer R. A. , Berger J. 
Published: February 2006

AbstractAlthough sex biases in natal dispersal are well known among birds and mammals, female‐biased dispersal in polygynous mammals is rare. North American porcupines are polygynous and recent evidence suggests that natal dispersal in this species may be female‐biased. We used data on disappearances, immigration, and reproductive behaviours to characterize natal dispersal and examine the extent to which inbreeding avoidance may motivate natal dispersal in porcupines. We predicted that, if female porcupines were the predominant dispersers, rates of disappearance and immigration would be higher for females than for males. Also, if females disperse to avoid mating with fathers, then the mean age of females at first conception should be less than the mean residence time of adult males. Population data suggested that natal dispersal was female‐biased because a higher proportion of females (31%) disappeared than males (11%), and 78% of 18 immigrants observed in the population were females. Data on pregnancies indicated that female age at first conception (≊25 months) was less than the mean residence time of adult males (≊26 months), suggesting that female porcupines may disperse to avoid incestuous matings with fathers. Little is known regarding potential resource competition between mothers and offspring, or on how philopatric males avoid mating with their mothers. Additional data are needed in these areas to interpret dispersal tendencies in porcupines.
The acquisition of host‐specific feather lice by common cuckoos (Cuculus canorus)
Authors: Brooke M. de L. , Nakamura Hiroshi 
Published: February 2006

AbstractThis study addresses the question of how three species of flightless feather lice (Phthiraptera) specific to a brood parasitic bird, the common cuckoo (Cuculus canorus), are transmitted from one cuckoo generation to the next in the absence of any direct contact between parent and young. None of 21 cuckoo nestlings examined shortly before fledging carried cuckoo lice; nor were any lice found in 19 nests in which cuckoos had laid. Cuckoos returning to Japan for their first breeding season were as likely to be lousy as, and carried similar louse loads to, older birds. These field observations are consistent with data arising from examination of museum skins from European breeding areas and from African wintering areas, and it is concluded that cuckoos acquire their lice between leaving the nest in summer and returning to the breeding grounds the following spring. This acquisition probably occurs via direct body‐to‐body contact between cuckoos, a supposition bolstered by some observations.
Spent females of deepwater squid Galiteuthis glacialis under the ice at the surface of the Weddell Sea (Antarctic)
Authors: Nesis K. N. , Nigmatullin Ch. M. , Nikitina I. V. 
Published: February 2006

AbstractTwo large (dorsal mantle length 42.5 and 47.5 cm), mated spent females of circum‐Antarctic bathypelagic cranchiid squid Galiteuthis glacialis were caught early in March 1992 at the surface of the ice hole in the western Weddell Sea over depths 1915‐1920 m by the team of the U.S.A.‐Russian Ice Station Weddell‐I. The structure of the reproductive system of adult females is described for the first time in detail.Both were gelatinous, devoid of tentacles, with empty or almost empty stomachs. The empty spermatangia (sperm reservoirs of spermatophores) 30‐35 mm in length were distributed in the mantle tissues parallel to the mantle surface and to each other in the dorso‐anterior part of the mantle: 13 in one female, parallel to the body axis, and 20 in the other, parallel (13) or perpendicular (7) to the body axis. In the latter case, they represented probably two mating events. The spermatangia lay nearer to the inner than the outer mantle side and opened by a round window on the inner side; the skin with chromatophores above them remained intact. The spermatozoa had one flagellum and rod‐like heads, length 5.0‐5.3 μm, width 1.2‐1.5 μm. The most characteristic features are: a very simple type of blood vessel branching making each micro‐gonad currant‐like, not grape‐like; a very compact disposition of oviducal, nidamental glands and gill, forming a united complex located on both sides of the mantle cavity; and an ovary connected by mesentery along all its length with the continuation of the stomach from the caecum to the end of the gastrogenital ligament. Only immature degenerating trophoplasmatic oocytes, length 0.9‐1.4, av. 1.0‐1.2 mm, were contained in ovaries; only one mature egg (length 3.3 mm, width 2.4‐2.5 mm) was found in each female. The absence of oocytes <0.9 mm and 1.5‐3.2 mm indicates that the maturation of oocytes proceeds rather synchronously, one large portion of eggs (some tens of thousands) matures in a short time while others degenerate. The residual fecundity is assessed to be approximately 20,000 eggs.It is hypothesized that mating occurs shortly before spawning and that mature males do not undergo gelatinous degeneration and do not lose tentacles. Spermatophores are placed on the inner side of the female's mantle with the aid of the male's tentacles and/or arms (less probably by the penis), but the exact mode of implantation is unclear. Spawning probably occurs at depths of adult habitat (approx. 500–2500m), may be multiportional but short; the exhausted female loses neutral buoyancy, rises to the surface and dies. Rising to the surface after spawning is a common feature of females of many meso‐ and bathypelagic squids undergoing gelatinous degeneration during maturation (Onychoteuthidae, Gonatidae, Histio‐teuthidae, Cranchiidae, etc.) and may explain the common occurrence of large deep‐water squids in the stomachs of seabirds, including those incapable of diving, and marine mammals.
Variations in harbour seal Phoca vitulina diet and dive‐depths in relation to foraging habitat
Authors: Tollit D. J. , Black A. D. , Thompson P. M. , Mackay A. , Corpe H. M. , Wilson B. , Van Parijs S. M. , Grellier K. , Parlane S. 
Published: February 2006

AbstractWe use information on the at‐sea distribution of radio‐tagged seals to identify the summer foraging areas used by 31 harbour seals from two different haul‐out sites in the Moray Firth, N.E. Scotland. We then determine whether seals tend to occur over particular sediment types or water depths as hypothesized by Härkönen (1987b), and assess whether local geographical variations in diet composition can be related to local differences in available foraging habitat.The majority of seals foraged within 30 km of their haul‐out site, consequently there was broad overlap between the foraging areas used by animals from the same site, but little overlap in the areas used by seals from different sites. Most seals foraged in water depths of 10‐50 m with mainly sandy sea‐bed sediments. Data on the distribution of dive depths of five seals which were fitted with time‐depth‐recorders indicated that seals were generally diving on, or close to, the sea‐bed. Occasional pelagic dives between the more common benthic dives were also observed. Between‐site differences in the seals' use of different water depths and sea‐bed sediments suggest that local geographical variations in diet were related to local differences in foraging habitats, but that habitat use also differed between individual seals.
Population dynamics, sexual activity, and reproduction failure in the fat dormouse (Myoxus glis)
Authors: Bieber C. 
Published: February 2006

AbstractPopulation ecology and reproduction of the fat dormouse (Myoxus glis L.) were studied in central Germany in the years 1992 and 1993. Animals were captured in wooden live‐traps twice a month, during trapping periods lasting three days each, and marked individually by tattooing. Demographic results show that, in three subpopulations, population structure differed extremely between 1992 and 1993. In 1992, more adult than subadult dormice occurred in the study area and the reverse was found in 1993. Subadults emerged from hibernation a little before or together with adult dormice. Adult males emerged significantly earlier than adult females. After a year with good reproductive success (1992), a total lack of reproduction was observed in 1993. Juvenile dormice were neither found in traps nor in nest‐boxes. The assessment of gonadal states indicated that all males (adult and subadult) remained in a state of testicular regression throughout the year 1993. Also, no female was found lactating. Reproductive failure coincided with a lack of food resources in the autumn of 1993 (e.g. fruits of oaks and beeches). Body mass changes imply high energy expenditure prior to mating in adult males. It seems likely that males in years with low food availability do not invest energy in reproduction.
Morphological and pelage characteristics of wild living cats in Scotland: implications for defining the ‘wildcat’
Authors: Daniels M. J. , Balharry D. , Hirst D. , Kitchener A. C. , Aspinall R. J. 
Published: February 2006

AbstractThe indigenous wildcat, Felis silvestris Schreber, 1775, and the introduced domestic cat, F. catus L., have been sympatric in Britain for more than 2000 years. As a result of interbreeding, any distinction between these two forms has become obscured, although a range of morphological criteria (pelage patterns, body measurements, gut lengths, skull morphometrics) and genetic techniques (immunological distances, electrophoresis, DNA hybridization) have been used previously to distinguish between them.A sample of 333 wild‐living cats in Scotland was assessed for coloration and markings of pelage, standard body measurements and weights, and (for carcasses only) limb bone lengths, intestine lengths, and skull measurements. These cats were also classified as wildcat, hybrid, or domestic cat according to traditional pelage criteria.Multivariate analyses on these variables, for adult cats, failed to show any clearly distinct groups. When each of the variables was analysed separately, only the distribution of limb bone and intestine length measurements suggested the possibility that two groups might exist. Group 1 cats had short intestines and long limb bones. Group 2 consisted of cats with long intestines and short limb bones. Although the characteristics defining cats in Group 1 were similar to those traditionally associated with wildcats, they exhibited a much broader range of pelage and coloration than traditionally described.The groups exhibited a degree of geographical separation. The distribution of Group 1 cats was found to be related to certain environmental variables, namely mean annual temperature and land with poor potential for forestry and agriculture, suggesting that there may be a biological basis for the separation. The implications of these results on the identification and taxonomy of the wildcat are significant. The concept of the wildcat and the domestic cat as separate species can be challenged. The paper highlights the complexity and difficulties for conventional taxonomy when used as a means for distinguishing between a wild type and its domesticated form where there is interbreeding.
A comparison of the gross morphology and micro‐anatomy of the foot pads in two fossorial and two climbing rodents (Mammalia)
Authors: Haffner Marianne 
Published: February 2006

AbstractThe foot pads of five rodents were studied by means of gross morphology and histology. The secretory portions of the glands are placed caudad to the openings of the ducts in species that mostly walk on the ground. This way the secretions are pressed out during walking by rolling on the foot pads craniad. In climbing species, the secretory portions are placed underneath the openings of the ducts and lead to secretion delivery during climbing by grasping. With their small and flat pads with few glands, digging species have a rather smooth and dry volar aspect to work in a shovel‐like way. In contrast, climbing species have large and soft foot pads with a lot of glands. The thickness of the cornified layer is positively correlated with the density of glands and increases strikingly from digging to climbing species. Although scent production is possible for these glands, this points to a function of the secretions in connection with the cornified layer. In climbing species, the secretions of glands can moisten the skin and thereby heighten the friction between volar and climbing surface to prevent the animal from slipping. The density of glands per unit of surface is doubled in the ridged skin of Muscardinus avellanarius in comparison with the coned skin in Micromys minutus. While M. minutus mainly climbs by grasping stalks of reed and can tighten the grip by increasing the grasping force, M. avellanarius often climbs by pressing the volar aspect on to the bark, whereby friction is increased by the moistened skin.
Effects of digestion, putrefaction, and taxidermy processes onDidelphis albiventrishair morphology
Authors: Quadros J. , Monteiro‐Filho E. L. A. 
Published: February 2006

AbstractHair morphology has been studied and applied in several subjects, such as food quality control, archaeology, criminology, and ecology. Although medullar and scale patterns of hair structure are well known for a variety of mammal species, the effects of hazardous conditions on the internal and external morphology of hair are not known. In the present work, white‐eared opossum (Didelphis albiventris) hairs were submitted to taxidermy, digestion, and putrefaction processes, and afterwards their structure was compared to control hairs, under the scanning electron microscope and light microscope. The results obtained indicate that the processes tested do not cause damage to the medullar and scale patterns of the opossum's hairs. In conclusion, based on the experiments withD. albiventrishairs, it is possible to compare hairs from museum collections or freshly collected hairs to hairs found in scats, gut contents, pellets, or other sources.
Condition and fecundity of translocated rock‐dwelling cichlid fish in Lake Malawi
Authors: Munthali S. M. , Ribbink A. J. 
Published: February 2006

AbstractThe condition factor and fecundity of the translocated rock‐dwelling cichlid fish, Cynotilapia afra, Pseudotropheus callainos, and Pseudotropheus tropheops‘red cheek’ at Thumbi West Island, southern Lake Malawi, were compared with those at their sites of origin, in the north of the lake. The guiding hypothesis was that these species, having originated from a region of the lake which is generally poor in nutrients, and been introduced to an area richer in nutrients, would be in better condition and more fecund there than at their sites of origin. That seemed to be the case. P. callainos and P. tropheops‘red cheek’ had significantly higher condition factors and fecundity indices at Thumbi West Island than at their sites of origin. However, both condition factor and fecundity of all the species studied fluctuated seasonally. The major peaks in condition factor coincided with either the wind‐induced lake upwelling from June to August, or the rains. Major peaks in fecundity occurred at the end of the rainy season, between February and April, or at the end of the upwelling period between September and October. The translocated species began to breed at a smaller size at their sites of origin in the north than at Thumbi West Island, probably as an adaptive response to a poor nutrient regime in the north.The increase in population of some translocated species can be partly attributed to their improved condition and fecundity due to enhanced nutrient availability at the site where they have been introduced. This may have negative implications for the native taxa, more particularly as competition for breeding space is rife among the rock‐dwelling cichlids of Lake Malawi.