bluuebunny/crossref_metadata_2025 huggingface dataset:
Habitat relationships of the lizard fauna in the Ramon erosion cirque, Negev Highlands (Israel)
Authors: Shenbrot G. , Krasnov B.
Published: March 2009

Lizards were censused in the Ramon erosion cirque (Central Negev. Israel) in 1994 on 24 one‐ha plots. Fifteen quantitative habitat variables, describing soil and vegetation structure, were measured at 25 points of each plot. Data were analysed to examine a classification of habitat types based on lizard species composition and the sets of environment variables influencing density of each lizard species. Three hundred and fifty three individuals of 14 lizard species were recorded on the sampling plots. Of these species, only one (Acanihodactylus boskianus) was abundant, eight (Plyodactylus gultatus, Stenodactylus sthenodactylus. Mesalina guttulata, M. olivieri, Ophisops elegans, Ablepharus kitaibellii, Chalcides ocellatus, Eumesces schneiderii) were common, and five (Laudukia stellio, Pseudotrapelus sinaitus, Trapelus pallidus, Hemidactylus turcicus, Tropiocolotes steudneri) were rare.

Four main habitat types and two sub‐types were distinguished: wadis among loess hills (I); rock outcrops among loess hills (II); rock outcrops among gravel plains (III); wadis among gravel plains (IVa); open gravel plains (IVb), and sand dunes (IVc). Lizard density and biomass were greatest (15‐19 ind./ha; about 200 g/ha) in IVb, and IVc, and least (3.7 ind./ha; 38 g/ha) in III. Lizard species richness and diversity were low (three species) in IVc and higher and similar (6‐10 species) in all other habitat types.

Among common and abundant species, densities of three (A. boskianus, O. elegans, A. kitaibellii)were highly (30‐60% of density dispersion) affected by habitat variables and densities of six (P. guttatus, S. sthenodactylus, M. guttulata, M. olivieri, C. ocellatus, E. schneiderii) were weakly (13‐30% of dispersion) affected. Densities of S. sthenodactylus, A. boskianus, and M. guttulata were determined mainly by soil structure, of M. olivieri and O. elegans mainly by structure of annual vegetation, and of C. ocellatus, A. kitaibellii, and E. schneiderii mainly by the structure of shrub vegetation. Density of P. guttatus was determined by both soil and annual vegetation structure.
Correlates of testis mass in capybaras (Hydrochaeris hydrochaeris): dominance assurance or sperm production?
Authors: Moreira J. R. , Macdonald D. W. , Clarke J. R.
Published: March 2009

To infer possible functions for the low gonadosomatic index and the high proportion of non‐spermatogenic tissue of capybara testes, we analysed the relationship between testes mass and the size and ratio of the testes compartments and, indirectly, their activities. We found that the testes mass of the capybara is closely associated with the size of androgen‐dependent scent glands and to the proportion of non‐spermatogenic tissue in the testis. We further investigated the associations between variables related to dominance and to sexual characters. The results suggest that dominance in capybaras is more associated with androgen‐dependent scent glands than with sperm production. We suggest that male capybaras compete for dominance with chemical and visual status signalling.
Notes on the morphology of the horns of a new artiodactyl mammal from Cambodia: Pseudonovibos spiralis
Authors: Dioli M.
Published: March 2009

A new species of bovid was discovered recently in Vietnam and Cambodia. At present, only the horns have been collected. A general description of the animal has been given by local hunters. The animal has been known since 1929 but was wrongly classified as an immature female kouprey (Box sauveli). Information gathered so far is incomplete but the bovid has been named Pseudonovibos spiralis, Peter Feiler, 1994a.
Test of Fox's assembly rule for functional groups in lemur communities in Madagascar
Authors: Ganzhorn J. U.
Published: March 2009

This paper examines to what extent an assembly rule designed by Fox for small terrestrial mammal communities is also applicable to communities of arboreal lemurs in Madagascar. This approach extends the testing of Fox's assembly rule to a new biogeographic region and a different phylogenetic radiation. The rule operates on a functional rather than on the taxonomic level. It specifies that: “There is a much higher probability that each species entering a community will be drawn from a different functional group, until each group is represented before the cycle repeats” (Fox, 1987: 201). This rule was tested with lemur communities from 14 sites in evergreen rain forests and nine sites in dry deciduous forests of Madagascar. Lemur species were assigned to one of three different functional groups based on dietary preferences: omnivores, frugivores, folivores. The rule applies almost perfectly to extant lemur communities in evergreen rain forest. Present communities in dry deciduous forests are not ordered as perfectly as communities of the rain forest sites, but they also deviate from random assembly as generated by the null model. Including extinct species of the dry forest ecosystem indicates that the at present unfavoured composition of the lemur community has been derived from a favoured state through extinction of the large folivorous and frugivorous lemur species. In the lemur communities of the eastern Malagasy rain forest, the assembly went through at least four, and in the Holocene dry forest ecosystem through even five, cycles without failing. This assigns considerable significance to the underlying mechanisms (most likely interspecific competition) and indicates that they are still effective in the forests of Madagascar. The dry deciduous forests might have been subject to recent natural and anthropogenic changes which interfere with the operation of these deterministic processes.
Reproductive strategies and the influence of date of birth on growth and sexual development of an aseasonally‐breeding ungulate: Reeves' muntjac (Muntiacus reevesi)
Authors: Chapman Norma G. , Furlong M. , Harris S.
Published: March 2009

Unlike most species of deer, Reeves' muntjac does not have a seasonal reproductive cycle. Births are equally distributed throughout the year and, irrespective of season of birth, females start breeding when they have reached a minimum body weight of about 10 kg. A significantly smaller proportion of females is born in the autumn/winter than the spring/summer, but there is no effect of maternal age or condition on foetal sex ratios for first or subsequent pregnancies. Whilst aseasonal breeding increases female productivity, males are only able to hold territories encompassing the ranges of a number of does for a relatively short period of time. It is argued that for muntjac there is much less inter‐sexual variation in lifetime reproductive success than for seasonally‐breeding polygynous cervids. Hence, although muntjac are sexually dimorphic and polygynous, females do not invest preferentially in male offspring.

Young males can be fertile from 36 weeks of age, when their first antlers are still in velvet. Whilst season of birth has no effect on the rate of sexual development in females, it does for males, with autumn‐born male fawns attaining sexual maturity earliest. This accelerated development occurs in the period following independence from the mother, and there is no evidence of a maternal cost in producing male fawns. Since the canine tusks are the main weapons for intra‐sexual conflict, there could be clear gains in terms of reproductive success for males that attain sexual maturity, adult weight and adult tusk size quickly, even though their first antlers are much smaller than those of older bucks. The hypothesis is presented that, for muntjac, the majority of a male's lifetime reproductive success is achieved relatively early in life when the canine tusks are in pristine condition, and that bucks lose their territories, and associated access to oestrous does, once the canines are broken.
Plasma androgen, social position, and response to GnRH in the marsupial sugar glider Petaurus breviceps (Marsupialia: Petauridae)
Authors: Bradley A. J. , Stoddart D. M.
Published: March 2009

The effect of gonadotrophin‐releasing hormone GnRH on plasma testosterone was examined in male sugar gliders Petaurus breviceps that were judged to occupy either the highest or lowest position in stable colonies consisting of up to four males and two females. Experiments were carried out at a time when breeding occurred in two of the three colonies, as evidenced by the presence of pouch young.

GnRH was either injected i.p. or as a single pulse via the i.v. route. Blood samples were collected using infra‐orbital sinus puncture when GnRH was injected i.p. but samples were collected from the jugular catheter when the GnRH was administered via the i.v. route.

Males that were judged to occupy the lowest position in each colony consistently had basal plasma testosterone concentrations which were lower than males judged to occupy the highest position. After GnRH administration, the plasma testosterone concentration rose markedly in all males, however, the highest plasma testosterone concentrations in a social group were, without exception, found to occur only in socially dominant males.

GnRH challenge of a dominant male from one colony introduced into an unfamiliar colony caused a marked decline both in its basal and stimulated plasma testosterone concentration within 24 hours of introduction. The body weight of the introduced male also decreased markedly.

Analysis of plasma testosterone concentrations in serially collected blood samples following i.v. injection of a single pulse of 10 μg GnRH showed that plasma testosterone concentration reached a peak at approximately 60 minutes after injection and had returned again to pre‐treatment levels after 3h. Both the basal and GnRH‐stimulated plasma testosterone concentrations were higher in the socially dominant males than they were in socially subordinate males.

GnRH injected i.p. into males captured in a wild population caused plasma testosterone concentrations to rise, however, considerable differences were found between males in both the basal and GnRH‐stimulated plasma testosterone concentrations. These differences in basal and stimulated testosterone concentrations are consistent with the sampling of males representing a range of positions in the hierarchy in several different social groups.
A single micropyle in the eggs of the most basal living actinopterygian fish, Polypterus (Actinopterygii, Polypteriformes)
Authors: Bartsch P. , Britz R.
Published: March 2009

Breeding of Polypterus, the most basal living actinopterygian, provided the opportunity to study the surface structure of its eggs with SEM for the first time. The investigation revealed the previously overlooked presence of a micropyle at the animal egg pole, thus rejecting recent textbook belief that the eggs of Polypterus slack a micropyle. Comparison with data for other gnathostomes demonstrates that eggs with a micropyle are a further synapomorphy for Actinopterygii and confirm membership of the Cladistia in that group.
Deviation from the Groundplan: a unique new species of freshwater planarian from South Brazil (Platyhelminthes, Tridadida, Paludicola)
Authors: Sluys R. , Hauser J. , Wirth Q. J.
Published: March 2009

The species Girardia biapertura Sluys, sp. nov. is described from the state of Rio Grande do Sul, Brazil. A unique derived character distinguishes this species from its congeners and all other planarians known to date, namely separate openings of the vasa deferentia at the tip of the penial papilla. Present knowledge on the distribution of Girardia species in Rio Grande do Sul is summarized.
Scent‐marking behaviour in free‐ranging golden‐faced saki monkeys, Pithecia pithecia chrysocephala: sex differences and context
Authors: Setz Eleonore Z. F. , Gaspar Denise de A.
Published: March 2009

Scent‐marking behaviour of golden‐faced saki monkey, Pithecia pithecia chrysocephala, was observed intermittently between 1987 and 1990 for a family group in a Central Amazonian forest fragment. Of 95 scent‐marking events (during 275.5 hours of observation), throat‐and‐chest rubbing accounted for all except one anogenital rubbing. Nine of the throat‐and‐chest markings also involved touching groin with hands and eight markings (including the anogenital), urinating on the marked branch. Marking behaviour is strongly sex related, with the adult male making 88.4% of the markings. Scent‐marking frequency by the adult male increased during breeding periods. Scent‐marking behaviour seems related to courtship, and possibly stimulates sexual behaviour. All regularly marked spots consisted of horizontal branches on commonly travelled routes. Eleven occurred in feeding trees and lianas, but none in sleeping trees. Scent‐marking behaviour in the monkeys studied here was not related to intergroup encounters and probably did not have a territorial function, although it may do so where different groups interact.
Black rats (Rattus rattus) from medieval Mertola (Baixo Alentejo, Portugal)
Authors: Morales A. , Rodríguez J.
Published: March 2009

This paper is about the analysis and interpretation of micromammal samples from archaeological sites while reporting on a black rat assemblage from XIIIthcentury Muslim levels in the city of Mertola. Questions concerning skeletal representation, size plus age estimations and bone fragmentation are discussed from a taphonomic standpoint. It is concluded that the tendency to interpret rodent accumulations in anthropic sites as evidence of preybird activities might be an oversimplification in need of substantial revision.
Comparative studies of the branchial morphology, gill area and gill ultrastructure of some thalassinidean mud‐shrimps (Crustacea: Decapoda: Thalassinidea)
Authors: Astall C. A. , Anderson S. J. , Taylor A. C. , Atkinson R. J. A.
Published: March 2009

The morphology, gill area and branchial formulae of six thalassinidean decapods (Calocaris macandreae, Jaxea nocturna, Callianassa subterranea, Upogebia stellata, U. deltauraandU. pusilla) are reported. Additionally, the rarely‐encounteredAxius stirhynchusreceives brief attention. Gill formulae are presented; the simplest arrangements are found in the Callianassidae and Upogebiidae. The deeper‐burrowing, deposit‐feeding species that are regularly exposed to prolonged periods of hypoxia, i.e.Callianassa subterraneaandJaxea nocturna, had significantly larger gill areas than thalassinideans that occupied more oxygenated burrows (Upogebiaspp.,Calocaris macandreae). The increase in gill area was a result of flattening of the trichobranchiate gill filaments giving rise to a phylloid gill form. It is suggested that the efficiency of gas transfer, and hence diffusing capacity, was enhanced in the phylloid gill by the larger gill area and, because of the reduced cuticle thickness, by the shorter water‐haemolymph diffusion distance. The increased diffusion capacity of the phylloid gill is interpreted as a functional adaptation to the more severe physicochemical burrow water conditions experienced byCallianassa subterraneaandJaxea nocturna.
Genetic and environmental variability of adult size in some stocks of the edible snail, Helix aspersa
Authors: Dupont‐Nivet Mathilde , Guiller Annie , Bonnet Jean‐Claude
Published: March 2009

This paper aims at providing a better knowledge of factors determining body size (especially the importance of heredity) in Helix aspersa Müller.

A preliminary investigation of snails from Maghreb allowed us to show the importance of heredity in the variability of body size and to produce an efficient design for a subsequent reliable estimation of heritabilities. All traits measured (diameter, height and weight) were highly correlated and weight appeared to be the most convenient measure of size.

The second experiment provided 4150 snails born from known individuals among 500 wild snails. Pedigrees were recorded. Weight and diameter revealed high heritabilities (>0.4), which is relevant for commercial selection since variability of both traits was important. The design also revealed a significant non‐genetic maternal effect and also that offspring from pairs where only one animal laid were bigger than offspring from pairs where both animals laid. This surprising observation has to be confirmed and its mechanisms studied.
Morphological correlates of the secondarily symmetrical pes of gekkotan lizards
Authors: Russell A. P. , Bauer A. M. , Laroiya R.
Published: March 2009

Gekkotan lizards, belonging to the family Gekkonidae, especially those that bear subdigital adhesive pads, tend to exhibit a pes that is symmetrical in appearance, rather than the asymmetrical configuration of lizards in general. Such a symmetrical morphology is reminiscent of that of primitive tetrapods, but is secondarily derived within lizards, as shown by way of qualitative assessments and quantitative comparisons of length and angular measurements of the pedal skeleton. The results reveal that trends towards secondary symmetry of the pes, including spreading of the metatarsal rays, relative shortening of the metatarsals, especially the fourth, and of the digits are already present in primitive gekkotans. It thus appears that such trends are precursors to the bearing of subdigital adhesive pads and not modifications to this end. The configuration of subdigital adhesive pads in gekkonoids appears to have resulted from exapting a syndrome of morphological modifications already present in the basal gekkotan stock.
The scaling of skeletal microanatomy in non‐human primates
Authors: Paine R. R. , Godfrey L. R.
Published: March 2009

The study of scale‐correlated changes in the external dimensions and cross‐sectional geometry of primate long bones is fundamental to our understanding of primate limb bone structural adaptation. To date, however, there have been no studies of the effects of mechanical loading on patterns of skeletal scaling at the microstructural level. To remedy this, we analysed patterns of microanatomical scaling in the humeri and femora of 107 adult primates belonging to the families Galagonidae and Cercopithecidae. Seven species were included in our analysis. Proximal, midshaft, and distal sections of humeri and femora of each individual were examined and secondary osteonal and cortical area were measured. Secondary osteonal area scales positively allometrically with cortical cross‐sectional area and with body mass. This pattern holds generally for humeri and femora—both within and across families. However, there are striking dissimilarities in the relative strengths of the allometric coefficients for humeri and femora measured for different families. These distinctions appear to be related to differences in the ways in which fore‐ and hindlimbs are loaded. Such differences highlight the promise of microstructural data and the importance of examining the confounding effects of locomotory behaviour in studies of skeletal scaling.
Mortality rates of mammals
Authors: Sibly R. M. , Collett D. , Promislow D. E. L. , Peacock D. J. , Harvey P. H.
Published: March 2009

Life‐table data of 56 natural populations of mammals were analysed, modelling mortality rate as a three‐phase step function of age (the step model) instead of using the Gompertz model. In the step model, mortality rale is constant in each phase. The phases correspond to juveniles and young and old adults. The age of transition between young and old adults is referred to as the age of senescence. This approach has the advantages that, for the first time, the age of senescence is identified objectively using a robust statistical procedure, and that young adult mortality rates are estimated without bias since no assumption is made about how adult mortality rate changes with age. A further statistical problem solved here that has previously caused difficulty is that of correctly accounting for the different levels of precision in data from different age classes.

Significant changes (P < 0.05) in adult mortality rate with age were found in 27 out of 56 populations. In 23 of these 27 cases, adult mortality rate increased with age. Juvenile mortality rate differed significantly from young adult mortality rate in 21 cases; in 18 of these the rate for juveniles was higher. These results are discussed in relation to earlier analyses, in particular that of Promislow (1991).
Cues by which suspended‐leaf nests of Euryattus (Araneae: Salticidae) females are recognized by conspecific males and by an aggressive‐mimic salticid, Portia fimbriata
Authors: Jackson Robert R. , Li Daiqin , Robertson Marianne B.
Published: March 2009

Females of Euryattus sp. indet, a salticid from Queensland, suspend rolled‐up leaves for nests. Euryattus males respond to conspecific females in nests with vibratory courtship. Portia fimbriata, a sympatric salticid that preys on Euryattus, responds to Euryattus females' nests by mimicking the courtship of Euryattus males. In the laboratory, cues by which potential mates (conspecific males) and potential predators (P. fimbriata females) recognize the nests of Euryattus females are investigated experimentally. Both the position of the leaf in relation to the substratum and the number of threads between the leaf and the substratum appear to be important cues by which both the Euryattus males and P. fimbriata females find nests. In addition, chemical cues from Euryattus females influence conspecific males, but there is no evidence that chemical cues are important to the predator.
Small mammals of a woodland‐savannah ecosystem in Zimbabwe. I. Density and habitat occupancy patterns
Authors: Linzey A. V. , Kesner M. H.
Published: March 2009

Population and habitat occupancy patterns of small mammals in five woodland‐savannah habitats (riverine grassland, miombo, mopane, talus, thicket) were studied at Sengwa Wildlife Research Area in Zimbabwe between July 1992 and July 1993. The study was initiated following a drought year and extended over a year of average rainfall. Fourteen species of small mammals were recorded during mark‐and‐recapture live‐trapping. Populations of most species were low during the 1992 cool dry and hot dry seasons, began increasing during the hot wet season, and attained peak densities during the 1993 cool dry season. The greatest amplitudes of density fluctuations were exhibited by the bush squirrel (Paraxerus cepapi) and the multimammate mouse (Mastomys natalensis). The numbers of habitats occupied by a single species ranged from one to four, although the majority of captures for each species tended to occur in a single habitat. The habitats occupied by an individual species during the season of lowest density was always the same as the one in which it reached its highest density. Temporal variation in density was greatest in riverine grassland and least in talus. Overall low densities during this study may have resulted from a combination of drought and impacts of large mammals on small mammal habitats.
Small mammals of a woodland‐savannah ecosystem in Zimbabwe. II. Community structure
Authors: Linzey A. V. , Kesner M. H.
Published: March 2009

Community characteristics of small mammals in five woodland‐savannah habitats (riverine grassland, miombo, mopane, talus, thicket) were studied at Sengwa Wildlife Research Area in Zimbabwe between July 1992 and July 1993. The study was initiated following a drought year and extended over a year of average rainfall. Fourteen species of small mammals were recorded during mark‐and‐recapture trapping, with the number of species known to occur in a single community ranging from three to nine. Species complements and biomass (g/ha) were lowest during the first portion of the study and peaked during the 1993 cool dry season. Species diversity (H') was lowest in the hot dry season and highest in the cool dry season. Temporal variation in biomass and species diversity was least in talus and greatest in riverine grassland. Communities in talus and thicket were most similar and those in riverine grassland and thicket least similar. In general, these results suggest that woodland‐savannah communities are highly variable and appear to be resource‐limited.
Correlations of red (Cervus elaphus) and roe (Capreolus capreolus) deer densities in Scottish forests with environmental variables
Authors: Latham J. , Staines B. W. , Gorman M. L.
Published: March 2009

The relationship between densities of red and roe deer and a range of environmental variables were investigated. The aim was to assess which factor, or combination of factors, was most associated with, and hence potentially responsible for, variations in densities of deer. Twenty plantation forests throughout Scotland were used as study sites and estimates of deer densities within them were based on dung‐group counts. Using ratios of cull records and local information, 10 forests were selected which were expected to give a wide range of deer densities to aid the correlation exercise. The other 10 were selected randomly from within the geographic range of both species and without expectation of density: this allowed deer densities to be used as predictors of each other in the analyses without any bias that selection on the basis of ratio may have introduced. The variables used in analyses included forest habitat structure, climate, vegetation composition, soil type, culling pressure, and the density of other deer species.

Red deer densities were positively correlated with mean daily temperature (P<0.05) throughout the year and mean daily snow depth (P<0.05) for October through to March, but negatively correlated with mean daily windspeed (P<0.05) for the quarter April to June. Roe deer density was negatively correlated with mean daily rainfall (P<0.05) throughout the year. Red deer density was negatively correlated (P<0.05) with an index of culling pressure, but roe deer density was uncorrelated with this parameter. The actual influence of culling pressure on red deer population density is unclear. Proportions of structural habitats within forests (defined by tree age classes and growth form) were uncorrelated with deer densities, but were secondary predictors of deer density in regression analyses: red deer density was predicted by the proportion of open‐thicket (trees aged 15‐28 years), and roe deer density by the proportion of restocked areas (0‐8 years) and pre‐thicket (9‐14 years). Stepwise multiple regression analyses suggested that high red deer density has an important negative influence on roe deer density (P<0.05), but that the reverse did not hold.

Possible mechanisms by which significantly correlated variables may influence deer densities are discussed. It is suggested that the differential variation of red and roe deer densities across Scotland may be a result of different climatic adaptations and, possibly, an interspecific influence of red deer on roe deer.
The demography of a high‐density badger (Meles meles) population in the west of England
Authors: Rogers L. M. , Cheeseman C. L. , Mallinson P. J. , Clifton‐Hadley R.
Published: March 2009

Data from the longest running capture‐mark‐recapture study of Eurasian badgers, in an undisturbed wild population at Woodchester Park in Gloucestershire, were used to investigate population dynamics. Twenty‐one social groups of badgers occupying an area of 7.3km2 were studied from 1978‐1993. The density increased steadily over the study period, reaching the highest published density known anywhere at 25.3 adults per km2 in 1993, and the average social group size increased to 8.8 adults (S.E. ± 0.85) in 1993. By 1993, 97% of the population trapped was of known age and overall the population consisted of 27% cubs and 73% adults. In addition, the results supported previous studies in that the population had an equal sex ratio as cubs, but became increasingly female biased with age. There was high juvenile mortality, nearly 50% dying in their first year. Between 58 and 90.2% of adult females did not breed each year.
Changes in muscle structure associated with somatic growth in Idiosepius pygmaeus, a small tropical cephalopod
Authors: Pecl G. T. , Moltschaniwskyj N. A.
Published: March 2009

Mantle muscle tissue of Idiosepius pygmaeus was examined to describe changes in structure and organization associated with growth. Growth in I. pygmaeus|DD was a function of both an increase in muscle fibre number and fibre size within muscle blocks. Continuous fibre production over the observed life span of I. pygmaeus was indicated by the presence of very small muscle fibres (< 1.0 μm in diameter) in substantial proportions in all sizes of individuals. Muscle blocks became larger as animals increased in size, although new muscle blocks were generated in all sizes of individuals. Mantle muscle fibres had a maximum size of 11 μm. Therefore, for an individual to continue increasing muscle block sizes, new fibres must be produced. This is further evidence of continuous fibre production throughout the size range of I. pygmaeus examined. The relative rates of muscle fibre generation and fibre growth depended on the size of the animal and position along the mantle (anterior, mid or posterior mantle). The predominance of small fibres and blocks at the anterior end of the mantle suggested that this was the primary growth region. Mitochondriapoor and mitochondria‐rich muscle fibres from small individuals had much larger mitochondrial cores than muscle fibres from larger animals. Changes in the muscle structure are discussed with respect to the metabolic and energetic requirements of I. pygmaeus, and how these may change with growth.
Limiting factors might obscure population regulation of moose (Cervidae:Alces alces) in unproductive boreal forests
Authors: Crête Michel , Courtois Réhaume
Published: March 2009

(1) In the core of the moose range in North America, moose numbers are regulated at a low equilibrium density (∼ 0.4 animal x km‐2) by predation when wolves coexist with a bear species. We hypothesized that top‐down dominance of moose could also occur further north in undisturbed boreal forest where densities generally reach less than 0.1 moose x km‐2.

(2) Summer forage production (leaves of shrubs and trees) averaged only 17 kg x ha‐1in our 3090 km2study area, whereas it ranged between 144 and 241 kg x ha‐1in the core of moose range in the Québec‐Labrador peninsula. Annual production of preferred winter forage (twigs of deciduous shrubs and trees) was also very low in the study area, contrary to that of the evergreen balsam fir, whose availability was comparable to that measured in southern ranges.

(3) Low forage production in the study area was due to a high proportion of outcrops (17%) and open black spruce stands (20%), and to the old age of most forest stands.

(4) Forage had a patchy distribution: production of leaves in the most productive habitat type, deciduous stands, exceeded by 22 times that measured in the coniferous stands. Forage distribution influenced habitat use by moose, which generally showed year‐round preferences for forage‐rich mixed and deciduous stands and resulted in large home ranges.

(5) Balsam fir dominated moose diets in late winter, whereas this plant species represented only 17‐19% of forage consumed further south in the moose range. We hypothesized that heavy consumption of balsam fir negatively affected the energy balance of moose in winter.

(6) Monitored females produced only 78 calves: 100 cows, during three consecutive years. This relatively low rate of calf production could be related to suboptimal nutrition in winter and in summer. We found a significant relationship between snow depth, summer temperature, and lactation rate, an index to cow:calf ratios in autumn. Lactation rate was more strongly related to weather of the preceding year than that of the current one, suggesting that weather had an immediate influence on body reserves of dams, but little impact on calf production until the next year.

(7) Calves experienced high survival, particularly during their first summer of life (90%), in contrast with southern moose populations exposed to higher predation pressure. Annual survival of adult females (87%) exceeded that of males (74%) because the latter were more vulnerable to hunting. Natural mortality was similar in both sexes, 8‐10%. In adults, predation may have been lighter, and other natural mortality causes higher in the study area than in the core of the moose range.

(8) Limiting factors. i.e. climate, drowning, played a greater role in the demography of the study moose population than predation, the suspected regulating factor. Our data set illustrates that regulation may be difficult to detect in unproductive environments, a common situation at the periphery of any species distribution.
Lifetime costs of cerebral palsy
Authors: KRUSE MARIE , MICHELSEN SUSAN ISHØY , FLACHS ESBEN MEULENGRACHT , BRØNNUM‐HANSEN HENRIK , MADSEN METTE , ULDALL PETER
Published: March 2009

This study quantified the lifetime costs of cerebral palsy (CP) in a register‐based setting. It was the first study outside the US to assess the lifetime costs of CP. The lifetime costs attributable to CP were divided into three categories: health care costs, productivity costs, and social costs. The population analysed was retrieved from the Danish Cerebral Palsy Register, which covers the eastern part of the country and has registered about half of the Danish population of individuals with CP since 1950. For this study we analysed 2367 individuals with CP, who were born in 1930 to 2000 and were alive in 2000. The prevalence of CP in eastern Denmark was approximately 1.7 per 1000. Information on productivity and the use of health care was retrieved from registers. The lifetime cost of CP was about €860 000 for men and about €800 000 for women. The largest component was social care costs, particularly during childhood. A sensitivity analysis found that alterations in social care costs had a small effect, whereas lowering the discount rate from 5 to 3 per cent markedly increased total lifetime costs. Discounting decreases the value of costs in the future compared with the present. The high social care costs and productivity costs associated with CP point to a potential gain from labour market interventions that benefit individuals with CP.
Early white‐matter abnormalities of the ventral frontostriatal pathway in fragile X syndrome
Authors: HAAS BRIAN W , BARNEA‐GORALY NAAMA , LIGHTBODY AMY A , PATNAIK SWETAPADMA S , HOEFT FUMIKO , HAZLETT HEATHER , PIVEN JOSEPH , REISS ALLAN L
Published: March 2009

Aim  Fragile X syndrome is associated with cognitive deficits in inhibitory control and with abnormal neuronal morphology and development.

Method  In this study, we used a diffusion tensor imaging (DTI) tractography approach to reconstruct white‐matter fibers in the ventral frontostriatal pathway in young males with fragile X syndrome (n=17; mean age 2y 9mo, SD 7mo, range 1y 7mo–3y 10mo), and two age‐matched comparison groups: (1) typically developing (n=13; mean age 2y 3mo, SD 7mo, range 1y 7mo–3y 6mo) and (2) developmentally delayed (n=8; mean age 3y, SD 4mo, range 2y 9mo–3y 8mo).

Results  We observed that young males with fragile X syndrome exhibited increased density of DTI reconstructed fibers than those in the typically developing (p=0.001) and developmentally delayed (p=0.001) groups. Aberrant white‐matter structure was localized in the left ventral frontostriatal pathway. Greater relative fiber density was found to be associated with lower IQ (Mullen composite scores) in the typically developing group (p=0.008).

Interpretation  These data suggest that diminished or absent fragile X mental retardation 1 protein expression can selectively alter white‐matter anatomy during early brain development and, in particular, neural pathways. The results also point to an early neurobiological marker for an important component of cognitive dysfunction associated with fragile X syndrome.
Brain oxidative stress and selective behaviour of aluminium in specific areas of rat brain: potential effects in a 6‐OHDA‐induced model of Parkinson’s disease
Authors: Sánchez‐Iglesias Sofía , Méndez‐Álvarez Estefanía , Iglesias‐González Javier , Muñoz‐Patiño Ana , Sánchez‐Sellero Inés , Labandeira‐García José Luís , Soto‐Otero Ramón
Published: March 2009

J. Neurochem. (2009) 109, 879–888.

The ability of aluminium to affect the oxidant status of specific areas of the brain (cerebellum, ventral midbrain, cortex, hippocampus, striatum) was investigated in rats intraperitoneally treated with aluminium chloride (10 mg Al3+/kg/day) for 10 days. The potential of aluminium to act as an etiological factor in Parkinson’s disease (PD) was assessed by studying its ability to increase oxidative stress in ventral midbrain and striatum and the striatal dopaminergic neurodegeneration induced by 6‐hydroxydopamine in an experimental model of PD. The results showed that aluminium caused an increase in oxidative stress (TBARS, protein carbonyl content, and protein thiol content) for most of the brain regions studied, which was accompanied by a decrease in the activity of some antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase). However, studies in vitro confirmed the inability of aluminium to affect the activity of those enzymes. The reported effects exhibited a regional‐selective behaviour for all the cerebral structures studied. Aluminium also enhanced the ability of 6‐hydroxydopamine to cause oxidative stress and neurodegeneration in the dopaminergic system, which confirms its potential as a risk factor in the development of PD.
The importance of pre‐thicket conifer plantations for nesting Hen Harriers Circus cyaneus in Ireland
Authors: WILSON MARK W. , IRWIN SANDRA , NORRISS DAVID W. , NEWTON STEPHEN F. , COLLINS KEVIN , KELLY THOMAS C. , O’HALLORAN JOHN
Published: March 2009

Hen Harriers Circus cyaneus are threatened across much of their range and their conservation requires appropriate habitat management. The locations of 148 Hen Harrier nests found in the Republic of Ireland during national breeding surveys in 2000 and 2005 were used to assess nest‐site selection. The distribution of these nests was compared to distributions of randomly located points to investigate selection at the scale of the nest‐site and landscape. The main nesting habitats selected were pre‐thicket stage of first and, particularly, second rotation plantations, mostly of exotic conifers. There was no evidence that the area of post‐closure plantations negatively affected Hen Harrier nest distribution. There was a positive correlation across study areas between changes in numbers of Hen Harrier nests between 2000 and 2005 and changes in the area of pre‐thicket second rotation plantations over the same period. The overall effect of plantation forests on breeding Hen Harriers in Ireland therefore appears to be positive. However, this study did not consider the effects of plantation habitats on breeding success. Improved grassland was strongly avoided as a nesting habitat. Furthermore, after controlling for the influence of nesting habitat on nest location, landscapes with a high percentage cover of improved grassland were also avoided. Further agricultural intensification of grassland in areas where Hen Harriers breed is likely to have a negative impact on this species. These results are required for the development of management strategies for the conservation of this species.
Effects of Surfactant Protein‐A on the Interaction of Pneumocystis murina with its Host at Different Stages of the Infection in Mice
Authors: LINKE MICHAEL J. , ASHBAUGH ALAN A. , KOCH JUDITH V. , LEVIN LINDA , TANAKA REIKO , WALZER PETER D.
Published: March 2009

ABSTRACT. We examined the effects of surfactant protein A (SP‐A), a collectin, on the interaction of Pneumocystis murina with its host at the beginning, early to middle, and late stages of infection. Pneumocystis murina from SP‐A wild‐type (WT) mice inoculated intractracheally into WT mice (WTS‐WTR) adhered well to alveolar macrophages, whereas organisms from SP‐A knockout (KO) mice inoculated into KO mice (KOS‐KOR) did not. Substitution of WT mice as the source of organisms (WTS‐KOR) or recipient host macrophages (KOS‐WTR) restored adherence to that found with WTS‐WTR mice. In contrast, when immunosuppressed KO and WT mice were inoculated with P. murina from a homologous source (KOS‐KOR, WTS‐WTR) or heterologous source (WTS‐KOR, KOS‐WTR) and followed sequentially, WTS‐KOR mice had the highest levels of infection at weeks 3 and 4; these mice also had the highest levels of the chemokine macrophage inflammatory protein‐2 and neutrophils in lavage fluid at week 3. Surfactant protein‐A administered to immunosuppressed KOS‐KOR mice with Pneumocystis pneumonia for 8 wk as a therapeutic agent failed to lower the organism burden. We conclude that SP‐A can correct the host immune defect in the beginning of P. murina infection, but not in the middle or late stages of the infection.
The Microaerophilic Flagellate, Trichomonas vaginalis, Contains Unusual Acyl Lipids but no Detectable Cardiolipin
Authors: GUSCHINA IRINA A. , HARRIS KRISTINA M. , MASKREY BEN , GOLDBERG BURT , LLOYD DAVID , HARWOOD JOHN L.
Published: March 2009

ABSTRACT. Previous lipid analysis of trichomonads has led to controversy as to whether these hydrogenosome‐containing organisms contain cardiolipin (CL), which is a characteristic component of mitochondria. Here we report a careful lipid analysis of the sexually transmitted protist Trichomonas vaginalis. Major lipids were phosphatidylethanolamine (42%) and phosphatidylcholine (20%) with lesser amounts of phosphatidylglycerol (PG) (12%) and non‐polar components. Two unusual lipids, acyl‐PG (8%) and ceramide phosphorylethanolamine (2%), were also significant components. The structures of these lipids were confirmed by tandem mass spectrometry following reverse‐phase high‐performance liquid chromatography. This is the first time ceramide phosphorylethanolamine has been reported in a trichomonad. In contrast, CL (diphosphatidylglycerol) could not be detected either by two‐dimensional thin‐layer chromatography or by mass spectrometry. These data are discussed in relation to the organism's phylogenetic origin as a parasite showing secondary adaptation to microaerobic conditions.
Ultrastructural Study of the Encystation and Excystation Processes in Naegleria sp.
Authors: CHÁVEZ‐MUNGUÍA BIBIANA , OMAÑA‐MOLINA MARITZA , CASTAÑÓN GUADALUPE , BONILLA PATRICIA , GONZÁLEZ‐LÁZARO MÓNICA , HERNÁNDEZ‐MARTÍNEZ DOLORES , SALAZAR‐VILLATORO LIZBETH , ESPARZA‐GARCÍA AMELIA , MARTÍNEZ‐PALOMO ADOLFO , ORTEGA‐PIERRES GUADALUPE
Published: March 2009

ABSTRACT. An important aspect of the biology of Naegleria sp. is the differentiation processes that occur during encystation and excystation. We studied these using both fluorescence and transmission electron microscopy techniques. In the initial stages of encystation, the cisternae of the endoplasmic reticulum became densely filled with a fibrillar material. Vesicles with a similar content that appeared to be derived from the cisternae were also observed in close contact with the plasma membrane. As encystation progressed, the fibrillar material became localized on the surface of the amoeba. An irregular compaction was observed in some areas of the cyst wall, which contained thin extensions of the cyst wall fibrillar material. Completely formed cysts had two to three ostioles, each sealed by an operculum. The operculum contained two areas in which a differential compaction of the fibrillar structure was observed. When excystation was induced, small dense granules (DGs), which were in close contact with fibrillar material were observed in the cyst cytoplasm and in the peritrophic space. During excystation, the more compact component of the operculum moves to enable the pseudopod of the emerging trophozoite to penetrate the ostiole. Vacuoles containing a fibrillar material, probably derived from the cyst wall, were observed in the cytoplasm of the pseudopodia. Our results provide a platform for further studies using biochemical markers to investigate the origin of the cyst wall as well as the role of DGs during excystation in Naegleria.
RXRA gene variations influence Alzheimer's disease risk and cholesterol metabolism
Authors: Kölsch Heike , Lütjohann Dieter , Jessen Frank , Popp Julius , Hentschel Frank , Kelemen Peter , Friedrichs Silvia , Maier T.A. Wolfgang , Heun Reinhard
Published: March 2009

Cholesterol metabolism is altered in Alzheimer's disease (AD). The nuclear hormone receptor Retinoic X Receptor a (RXRa) is a member of the nuclear ligand‐activated transcription factor family. RXRs are key regulators of cholesterol synthesis and thus cholesterol metabolism. We performed a systematic screen for gene variants in the RXRA gene. The effect of these gene variants on the risk of AD was investigated in 405 AD patients (mean age: 74.27 ± 9.37 years; female 78.6%) and 347 controls (mean age: 73.26 ± 8.37 years; female 57.2%). Furthermore, the influence of RXRA gene variants on CSF and plasma levels of cholesterol, lathosterol and 24S‐hydroxycholesterol were evaluated. One of the identified seven SNPs in RXRA influenced AD risk in our single marker analysis (rs3132293: P= 0.006). Haplotype analysis identified a three‐marker haplotype (TGC) consisting of rs3118570, rs1536475 and rs3132293, which decreased the risk of AD (P= 0.009). The single marker rs3132293 (P= 0.026) and the TGC haplotype (P= 0.026) influenced CSF lathosterol levels in non‐demented controls, and cholesterol levels in the combined sample comprising AD patients and controls (Rs3132293: P= 0.050; TGC haplotype: P= 0.035). 24S‐Hydroxycholesterol CSF and plasma levels were also influenced by rs3132293 (CSF: P= 0.004; plasma: P= 0.001) and the TGC haplotype (CSF: P= 0.004; plasma: P= 0.002); this effect was most pronounced in AD patients (rs3132293: CSF: P= 0.009, plasma: P= 0.002; TGC haplotype: CSF: P= 0.019, plasma: P= 0.005). Our results suggest that RXRA gene variants might act as risk factor for AD via an influence on cerebral cholesterol metabolism.
Typical 2‐Cys peroxiredoxins – structures, mechanisms and functions
Authors: Hall Andrea , Karplus P. A. , Poole Leslie B.
Published: March 2009

Peroxiredoxins are abundant cellular antioxidant proteins that help to control intracellular peroxide levels. These proteins may also function, in part, through an evolved sensitivity of some peroxiredoxins towards peroxide‐mediated inactivation in hydrogen peroxide signaling in eukaryotes. This review summarizes recent progress in our understanding of the catalytic and regulatory mechanisms of ‘typical 2‐Cys’ peroxiredoxins and of the biological roles played by these important enzymes in oxidative stress and nonstress‐related cellular signaling. New evidence suggests localized peroxide buildup plays a role in nonstress‐related signaling.