Publications

seasonal dynamics of pneumocystis carinii in the field vole, microtus agrestis, and in the common shrew, sorex araneus, in finland.	seasonal dynamics of pneumocystis carinii in the field vole, microtus agrestis, and in the common shrew, sorex araneus, were investigated in southern and central finland by microscopical examination of methenamine silver-stained tissue sections. in both host species at both localities the number of p. carinii cyst forms was highest in late autumn (november). in s. araneus, prevalence was higher than in m. agrestis during all seasons. none of the animals was heavily infected or apparently ill, an ...	1999	10070655
immunocytochemical study of parafollicular (c) cells of the thyroid in some wild rodents.	studies were done on 3 wild species of rodents: field voles (microtus agrestis, linnaeus 1761), bank voles (clethrionomys glareolus, schreber 1780), and forest mice (apodemus flavicollis, melchior 1834). immunocytochemical reactions were used to detect calcitonin (ct), calcitonin gene-related peptide (cgrp), neuron-specific enolase (nse), chromogranin a (cga) in the thyroid parafollicular (c) cells in all species examined. antisera to human ct, rat cgrp, bovine cga, rat nse and human nse give pr ...	1999	10332521
cowpox: reservoir hosts and geographic range.	it is generally accepted that the reservoir hosts of cowpox virus are wild rodents, although direct evidence for this is lacking for much of the virus's geographic range. here, through a combination of serology and pcr, we demonstrate conclusively that the main hosts in great britain are bank voles, wood mice and short-tailed field voles. however, we also suggest that wood mice may not be able to maintain infection alone, explaining the absence of cowpox from ireland where voles are generally no ...	1999	10459650
disease patterns in field and bank vole populations during a cyclic decline in central finland.	declining field vole (microtus agrestis) and bank vole (clethrionomys glareolus) populations were sampled (117 field voles and 34 bank voles) in south-central finland during the winter of 1988-89. the last surviving field voles were caught in april and bank voles in february. a subsample (16) of the april field voles were taken live to the laboratory for immunosuppression. the histopathology of the main internal organs and the presence of aerobic bacteria and certain parasites were studied. in t ...	2000	10670697
genetic and morphological heterogeneity in small rodent whipworms in southwestern europe: characterization of trichuris muris and description of trichuris arvicolae n. sp. (nematoda: trichuridae).	genetic and morphological variability of whipworms trichuris roederer, 1761 (nematoda: trichuridae), parasites of small rodents in southwestern europe, was studied. isozyme patterns of natural populations of nematodes parasitizing rodent species of the muridae (apodemus sylvaticus, apodemus flavicollis, mus musculus) and arvicolidae (clethrionomys glareolus, microtus agrestis, microtus arvalis) were analyzed at 6 putative loci. two diagnostic loci were found in t. muris from muridae and from arv ...	2000	10864238
effect of long-term cold exposure on antioxidant enzyme activities in a small mammal.	aerobic organisms continually face exposure to reactive oxygen species (ros) and many have evolved sophisticated antioxidant systems to effectively remove them. any increase in ros production or weakening in this defense system may ultimately lead to oxidative stress and cellular damage. we investigated whether long-term cold exposure, which is known to lead to an elevation in metabolic rate, increased the activities of the ros-scavenging enzymes, catalase (cat), selenium-dependent glutathione p ...	2000	10889458
role of small mammals in the persistence of louping-ill virus: field survey and tick co-feeding studies.	louping-ill (li) is a tick-borne viral disease of red grouse, lagopus lagopus scoticus lath. (tetraonidae: galliformes), and sheep, ovis aries l. (bovidae: artiodactyla), that causes economic loss to upland farms and sporting estates. unvaccinated sheep, grouse and mountain hares, lepus timidus l. (leporidae: lagomorpha), are known to transmit li virus, whereas red deer, cenrus elaphus l. (cervidae: artiodactyla), and rabbits, oryctolagus cuniculus l. (leporidae: lagomorpha), do not. however, th ...	2000	11016435
hypothalamo-neurohypophysial magnocellular neuroendocrine system of field voles after acute heat or cold stress.	hypothalamo-neurohypophysial magnocellular neuroendocrine system (h-nh mc nes) of field voles was described in normal conditions and after acute heat or cold stress. 60 mature males of field voles were used for examinations after 2 weeks of adaptation to stable conditions of laboratory keeping. 10 animals were the controls. another group of 25 field voles were subjected to sudden cold of -15 degrees c for 3 hours. the third group of 25 field voles were subjected to sudden heat of +32 degrees c f ...	2000	11712427
differences in the meiotic pairing behavior of gonosomal heterochromatin between female and male microtus agrestis: implications for the mechanism of heterochromatin amplification on the x and y.	it is generally thought that pairing and recombination between the x and y chromosome in eutherian mammals is important for the occurrence of normal meiotic division and the production of functional gametes. microtus agrestis is one of the examples whose giant and heterochromatin-rich sex chromosomes fail to establish a durable association at any stage of the first meiotic division in males. in contrast, in females, synapsis starts in the euchromatic short arm and pairing progresses unidirection ...	2000	11173866
can non-shivering thermogenesis in brown adipose tissue following na injection be quantified by changes in overlying surface temperatures using infrared thermography?	we aimed to investigate whether infra red thermography (irt) can be used to measure and quantify non-shivering thermogenesis (nst) in the short-tailed field vole microtus agrestis, by directly comparing it with a standard method, i.e. metabolic response following noradrenaline injection (na). mean skin surface temperature overlying brown adipose tissue (bat) depot was 0.82 degrees c higher than mean surface temperature that did not overly bat. the difference in temperature increased by 1.26 degr ...	2001	11163923
[comparison observation on the mature alveolar of echinococcus sibiricensis and echinococcus multilocularis in the experimentally infected white mice].	the alveolar echinococcus is one of the most dangerous worm parasites in man. rausch and schiller reported a new species, echinococcus sibiricensis n. sp. from arctic fox, alpex logopus, on st. lawrence island of alaska, usa. according to the view of vogel, the sibiricensis form is only a geographical race or subspecies of europe echinococcus multilocularis. so far, the two names, echinococcus multiocularis multilocularis and echinococcus multilocularis sibiricensis, existed in many references a ...	2001	12549203
generation of periodic waves by landscape features in cyclic predator-prey systems.	the vast majority of models for spatial dynamics of natural populations assume a homogeneous physical environment. however, in practice, dispersing organisms may encounter landscape features that significantly inhibit their movement. we use mathematical modelling to investigate the effect of such landscape features on cyclic predator-prey populations. we show that when appropriate boundary conditions are applied at the edge of the obstacle, a pattern of periodic travelling waves develops, moving ...	2002	11886619
comparison of glycoprotein hormone alpha-subunits of laboratory animals.	the common alpha-subunit of glycoprotein hormones (cgalpha) is a core protein shared by follicle-stimulating hormone (fsh), luteinizing hormone (lh), and thyroid-stimulating hormone (tsh). in order to obtain a molecular basis for an efficient superovulation technique applicable to a wide range of animal species and to discuss the phylogenetic aspect based on molecules related to the reproductive system, we determined cdna sequences of cgalpha in seven laboratory animals: the guinea pig, mongolia ...	2002	12112597
rodent host specificity of european hantaviruses: evidence of puumala virus interspecific spillover.	in order to investigate rodent host specificity of european hantaviruses, experimental infection of colonized and wild-trapped rodents was performed. in addition to the natural rodent reservoir, clethrionomys glareolus, puumala hantavirus (puuv) could infect colonized microtus agrestis and lemmus sibiricus, but not syrian hamsters or balb/c mice. neither c. glareolus, nor m. agrestis, could be readily infected by tula hantavirus (tulv). wild-trapped apodemus flavicollis and a. agrarius, the natu ...	2002	12376967
copy and paste: the impact of a new non-l1 retroposon on the gonosomal heterochromatin of microtus agrestis.	mobile elements are most abundant in the mammalian genome, comprising at least 40-50% of the dna. they are differentiated into two most prominent families: the line elements, which are preferentially located in the g-bands, and sines, which are clustered in the r-bands. we report here a novel mammalian non-l1-retroposon, which invaded the genome of microtus agrestis in a very short time from an evolutionary viewpoint. no relevant sequence homology could be demonstrated to known sequences in the ...	2002	12438796
the lateral enamel lamina--component of tooth primordia in selected mammalian species.	the lateral enamel lamina (lel) is a part of the enamel organ, which is probably not involved in tooth formation. it represents, besides the "stalk" of the tooth primordium, a second interconnection between enamel organ and oral epithelium or vestibular lamina. we detected the lel in the sheep (ovis aries), the dolphin (stenella attenuata), and the vole (microtus agrestis) by light microscopy and computer-aided three-dimensional reconstruction. the lel could be found in cap to bell stage tooth p ...	2002	12494916
[quantitative investigation of reproduction of condensed chromatin of sex chromosomes during trophoblast cell polyploidization and endoreduplication in the east european field vole microtus rossiaemeridionalis].	simultaneous measurement of dna content in cell nuclei and condensed chromatin bodies formed by heterochromatized regions of sex chromosomes (gonosomal chromatin bodies, gcb) has been performed in two trophoblast cell populations of the east-european field vole microtus rossiaemeridionalis, namely in the proliferative population of trophoblast cells of the junctional zone of placenta and in the secondary giant trophoblast cells. one or two gonosomal chromatin bodies have been observed in trophob ...	2002	12506668
mycobacterium microti infection (vole tuberculosis) in wild rodent populations.	mycobacterium microti (vole tuberculosis) infections in small wild mammals were first described more than 60 years ago in several populations in great britain. few studies of vole tuberculosis have been undertaken since then, and little is known about the relationship between m. microti isolates originating from different populations or at different times or of the prevalence of this infection in wild rodent populations, despite human cases of m. microti infections being increasingly reported. i ...	2002	12202566
demographic, mechanistic and density-dependent determinants of population growth rate: a case study in an avian predator.	identifying the determinants of population growth rate is a central topic in population ecology. three approaches (demographic, mechanistic and density-dependent) used historically to describe the determinants of population growth rate are here compared and combined for an avian predator, the barn owl (tyto alba). the owl population remained approximately stable (r approximately 0) throughout the period from 1979 to 1991. there was no evidence of density dependence as assessed by goodness of fit ...	2002	12396509
genetic evidence for tula virus in microtus arvalis and microtus agrestis populations in croatia.	to determine the threat of hantavirus infection to u.s. forces, small mammals were sampled from training areas within croatia. of the 152 samples, 20 were positive for tula virus (tul), 12 common voles (microtus arvalis) and eight field voles (microtus agrestis). sequences from m. agrestis were found in five and sequences from m. arvalis were found in six of seven sequence groups. the high percentage of the same tul sequences in m. agrestis and m. arvalis suggests the co-occurrence of this virus ...	2002	12656127
the consequences of acute cold exposure on protein oxidation and proteasome activity in short-tailed field voles, microtus agrestis.	during cold exposure, animals upregulate their metabolism and food intake, potentially exposing them to elevated reactive oxygen species (ros) production and oxidative damage. we investigated whether acute cold (7 +/- 3 degrees c) exposure (1, 10, or 100 h duration) affected protein oxidation and proteasome activity, when compared to warm controls (22 +/- 3 degrees c), in a small mammal model, the short-tailed field vole microtus agrestis. protein carbonyls and the chymotrypsin-like proteasome a ...	2002	12106821
antioxidant enzyme activities, lipid peroxidation, and dna oxidative damage: the effects of short-term voluntary wheel running.	we examined the effect of voluntary exercise on antioxidant enzyme activities (catalase, glutathione peroxidase, superoxide dismutase) in skeletal muscle (hind- and forelimb) and heart of a model small mammal species: short-tailed field vole microtus agrestis. in addition, dna oxidation was determined in lymphocytes and hepatocytes using the comet assay and lipid peroxidation estimated in hindlimb muscle by measurement of thiobarbituric-acid-reactive substances. voles (approximately 6 weeks old) ...	2002	12054476
dynamics and trophic interactions of small rodents: landscape or regional effects on spatial variation?	geographically varying rodent dynamics may be due to specific landscape effects or to regional variation. two common vole species (clethrionomys glareolus and microtus agrestis), their main predators and their impact on some important food items were monitored in sweden on forest clearcuts in two different landscape types, situated in two different regions with different climatic conditions. censuses, with 10-16 clearcuts in each landscape and both landscapes in the two regions, were designed to ...	2002	28547149
changes in individual quality during a 3-year population cycle of voles.	in small mammal populations with multiannual oscillations in density, the occurrence of large individuals in the peak phase (the "chitty effect") is a typical feature, but mechanisms behind this phenomenon have remained unclear. we analysed long-term data sets collected in western finland between 1984 and 1992 to: (1) find out how the body size and body condition of voles (microtus agrestis, m. rossiaemeridionalis, clethrionomys glareolus) and shrews (sorex araneus) was associated with the 3-yea ...	2002	28547147
bisphenol a affects endocrine physiology and biotransformation enzyme activities of the field vole (microtus agrestis).	bisphenol a (bpa), an environmental estrogen, was given subcutaneously for 4 days to 48 field voles at three doses (10, 50, or 250 mg kg(-1) day(-1)). plasma sex steroids, thyroxine, weight-regulatory hormones, and liver biotransformation enzymes were determined. there was no mortality in the control group but the mortality in the bpa-exposed animals was significant. bpa increased the plasma testosterone concentrations at 250 mg bpa kg(-1) day(-1). the plasma ghrelin levels measured from pooled ...	2002	12030774
choice of voles among genotypes of birch seedlings: its relationship with seedling quality and preference of insects.	selective feeding by herbivores on establishing seedlings has been suggested to affect genotype frequencies in several plant populations. the existence of genotypes susceptible to herbivores calls for an explanation in such populations. in the present study we assessed the choice of multiple herbivores, field voles (microtus agrestis) and insects, among genotypes of silver birch (betula pendula) representing variation occurring in a naturally regenerated stand. we examined how food choice of vol ...	2002	28547050
proliferating cell nuclear antigen (pcna) expression in tooth primordia in the field vole (microtus agrestis, rodentia).	cell proliferation in developing tooth germs has been studied particularly using bromodeoxyuridine (brdu) incorporation into growing tooth primordia and by counting and three-dimensional (3d) reconstruction of mitoses in serial sections of developing teeth. pcna has been proposed as an alternative marker of proliferation activity. the aim of our study was to detect immunohistochemically locations of pcna-positive cells in developing tooth germs of microtus agrestis (rodentia). pcna expression co ...	2002	12489149
phylogeography of field voles (microtus agrestis) in eurasia inferred from mitochondrial dna sequences.	in a distribution-wide phylogeographic survey of the field vole (microtus agrestis), 75 specimens from 56 localities across eurasia were examined for dna sequence variation along the whole 1140 base pair (bp) mitochondrial (mt) cytochrome b gene. the species is subdivided into three main mtdna phylogeographic groups - western, eastern and southern - with largely allopatric distributions. the western phylogeographical group is found in west and central europe and spread most probably from a glaci ...	2002	12453244
resting and daily energy expenditures of free-living field voles are positively correlated but reflect extrinsic rather than intrinsic effects.	resting metabolic rates at thermoneutral (rmrts) are unexpectedly variable. one explanation is that high rmrts intrinsically potentiate a greater total daily energy expenditure (dee), but recent work has suggested that dee is extrinsically defined by the environment, which independently affects rmrt. this extrinsic effect could occur because expenditure is forced upwards in poor habitats or enabled to rise in good habitats. we provide here an intraspecific test for an association between rmrt an ...	2003	14615588
quantitative investigation of reproduction of gonosomal condensed chromatin during trophoblast cell polyploidization and endoreduplication in the east-european field vole microtus rossiaemeridionalis.	simultaneous determinations of dna content in cell nuclei and condensed chromatin bodies formed by heterochromatized regions of sex chromosomes (gonosomal chromatin bodies, gcb) have been performed in two trophoblast cell populations of the east-european field vole microtus rossiaemeridionalis: in the proliferative population of trophoblast cells of the junctional zone of placenta and in the secondary giant trophoblast cells. one or two gcbs have been observed in trophoblast cell nuclei of all e ...	2003	12725646
phytosterols affect endocrinology and metabolism of the field vole (microtus agrestis).	phytosterols or plant sterols (ps) enter the ecosystem via pulp mill effluents. they are also consumed by the general population of developed countries in natural remedies and margarines to lower elevated serum cholesterol levels. this study screened the endocrine and enzymatic parameters of the field vole (microtus agrestis) for the effects of subchronic ps exposure at three doses (0, 5, or 50 mg of ps kg(-1) day(-1)). ps at 5 or 50 mg kg(-1) day(-1) decreased the relative liver weight of the v ...	2003	12563026
[amino acid composition of blood proteins of field voles (microtus oeconomus pall.), living in different radioecological conditions].		2003	4780543
[seasonal and age variations in the skeletal dose of radiation due to incorporated strontium 90 in field voles under natural conditions].		2003	5608542
two-year study of examination of blood from wild rodents for the presence of antiborrelian antibodies.	the aim of our work was to find the positivity rate of antibodrrelian antibodies (igg) in wild-living rodents in a locality situated in north moravia, czech republic. results of a survey for heart rinses (172) and sera (2) antibodies to borrelia burgdorferi sensu lato (s.l.) from 6 species of 174 wild rodents from the northern part of the czech republic are presented. samples were obtained in 2001-2002 at one locality (studenka, 49 degrees 44', 18 degrees 05'). host samples included yellow-necke ...	2003	14677912
bartonella infection in sylvatic small mammals of central sweden.	sylvatic small mammals were captured in rural habitats near uppsala, sweden, to measure the prevalence of bartonella infections, characterize bacterial isolates and identify their host range, and increase our understanding of host-pathogen ecology. during 7 nights of trapping at 3 localities, 236 small mammals were captured (trap success 30%). bartonella were isolated from bloods of apodemus flavicollis (19 of 110 tested), apodemus sylvaticus (6/25), clethrionomys glareolus (9/60), microtus agre ...	2003	12613756
the wood mouse is a natural host for murid herpesvirus 4.	infection of laboratory mice by the murid herpesvirus 4 (mhv-4) is a much studied model system for gammaherpesvirus pathogenesis. little, however, is known about its natural host range, epidemiology and pathogenesis outside the laboratory. we have studied mhv-4 infection in free-living murids in the uk. using a combination of serology and pcr analysis, we found that mhv-4 was endemic in wood mice (apodemus sylvaticus) but not in two species of voles (clethrionomys glareolus, microtus agrestis). ...	2003	12533706
exposure of small mammals, in particular the wood mouse apodemus sylvaticus, to pesticide seed treatments.	field exposure of small mammals to fungicide-treated wheat seed was investigated over three weeks following drilling on fields near york, united kingdom. seed consumption by small mammals trapped on and immediately adjacent to the drilled fields was quantified by measuring the amount of seed in the stomach. in addition, exposure to one seed-treatment, fluquinconazole, was quantified by measuring residues of the fungicide in the stomach, liver, and intestine. the wood mouse, apodemus sylvaticus, ...	2003	12729225
low levels of nucleotide diversity in mammalian y chromosomes.	sex chromosomes provide a useful context for the study of the relative importance of evolutionary forces affecting genetic diversity. the human y chromosome shows levels of nucleotide diversity 20% that of autosomes, which is significantly less than expected when differences in effective population size and sex-specific mutation rates are taken into account. to study the generality of low levels of y chromosome variability in mammalian genomes, we investigated nucleotide diversity in intron sequ ...	2004	14595096
a striated muscle on the hard palate of rodents and rabbits.	summary a striated muscle of the hard palate has been previously described in some rodents and rabbits. it is not termed in the official veterinary anatomical nomenclature. the aim of this work was to verify the existence of this muscle. heads of the golden hamster (mesocricetus auratus), the guinea pig (cavia aperea f. porcellus), the laboratory rat (rattus norvegicus var. alba), the field vole (microtus agrestis) and the domestic rabbit (oryctolagus cuniculus f. domesticus) have been dissected ...	2004	15027950
zoonotic reservoir of babesia microti in poland.	babesiosis is as one of the emerging human and animal diseases transmitted by ticks. it is caused intraerythrocytic parasites of the genus babesia. current evidence of human babesiosis suggests that the majority of cases are involved by babesia divergens and babesia microti piroplasms. as zoonotic reservoir of b. microti serve small mammals--insectivores and rodents. the occurrence of this parasite in natural environment in poland is documented for various regions, in the wide range of mammal ho ...	2004	15787199
sex-biased maternal investment in voles: importance of environmental conditions.	adaptive bias in sex allocation is traditionally proposed to be related to the condition of mothers as well as to the unequal fitness values of produced sexes. a positive relationship between mother condition and investment into male offspring is often predicted. this relationship was also recently found to depend on environmental conditions. we studied these causalities experimentally using a design where winter food supply was manipulated in eight outdoor-enclosed populations of field voles mi ...	2004	15306337
apoptosis distribution in the first molar tooth germ of the field vole (microtus agrestis).	apoptosis represents an important process in organ and tissue morphogenesis and remodeling during embryonic development. a role for apoptosis in shape formation of developing teeth has been suggested. the field vole is a useful model for comparative studies in odontogenesis, particularly because of its contrasting molar morphogenesis when compared to the mouse. however, little is known concerning apoptosis in tooth development of this species. morphological (cellular and nuclear alterations) and ...	2004	15385152
identification of bartonella species in rodents, shrews and cats in denmark: detection of two b. henselae variants, one in cats and the other in the long-tailed field mouse.	small mammals and stray cats were trapped in two areas of north zealand, denmark, and their blood cultured for hemotrophic bacteria. bacterial isolates were recovered in pure culture and subjected to 16s rdna gene sequencing. bartonella species were isolated from five mammalian species: b. grahamii from microtus agrestis (field vole) and apodemus flavicollis (yellow-necked field mouse); b. taylorii from m. agrestis, a. flavicollis and a. sylvaticus (long-tailed field mouse); b. tribocorum from a ...	2004	15511270
disease dynamics in cyclic populations of field voles (microtus agrestis): cowpox virus and vole tuberculosis (mycobacterium microti).	the possible role of pathogens in rodent population cycles has been largely neglected since elton's 'epidemic hypothesis' of 1931. to revisit this question, 12 adjacent, cyclic but out-of-phase populations of field voles (microtus agrestis) in north east england were studied and the initial results are presented here. the prevalences of antibodies to cowpox virus and of clinical signs of mycobacterium microti infection (vole tuberculosis) showed delayed (not direct) density dependence (with a la ...	2004	15255106
origin and developmental fate of vestigial tooth primordia in the upper diastema of the field vole (microtus agrestis, rodentia).	odontogenesis in voles is a convenient model to test hypotheses on tooth development generated from investigations in the mouse. similar to other rodents, the functional dentition of the vole includes a toothless diastema. at its mesial end, a vestigial tooth bud has been found in the upper jaw of vole embryos. the aim of this study was to analyse the developmental dynamics of vestigial tooth structures in the upper diastema of the field vole and to compare it with the situation in the mouse.	2004	15748693
[anoplura of rodents (rodentia) in northern poland].	anoplura of rodents (rodentia) in northern poland. above 100 rodents belonging to 6 species (clethrionomys glareolus, microtus agrestis, m. arvalis, apodemus flavicollis, a. sylvaticus, mus musculus) caught in the various habitations were examined. the parasites found represented three species of anoplura: hoplopleura acanthopus, h. affinis and polyplax serrata. h. acanthopus appeard to be the most common parasite; it was found in all examined hosts, while mostly on the bank vole.	2004	16859044
optimal body size and energy expenditure during winter: why are voles smaller in declining populations?	winter is energetically challenging for small herbivores because of greater energy requirements for thermogenesis at a time when little energy is available. we formulated a model predicting optimal wintering body size, accounting for the scaling of both energy expenditure and assimilation to body size, and the trade-off between survival benefits of a large size and avoiding survival costs of foraging. the model predicts that if the energy cost of maintaining a given body mass differs between env ...	2004	15026979
a highly divergent mitochondrial dna lineage of microtus agrestis in southern europe.	the mediterranean peninsulas constitute important areas for endemism and intraspecific variation, and are likely places for cryptic biodiversity. we assessed the phylogeographic pattern of field voles (microtus agrestis) in southern and central europe by sequence analysis of a 385-bp fragment of the mitochondrial cytochrome b gene in 74 specimens from 44 localities. the majority of samples consisted of skulls collected from owl pellets. the data revealed a highly distinct cytochrome b lineage in ...	2004	14666134
[a study of dna depolyploidization and depolytenization of the heterochromatized gonosomal chromatin bodies in the secondary giant trophoblast cells of the field vole microtus rossiaemeridionalis using cytophotometry].	a study was made of the distribution of the heterochromatized gonosomal chromatin bodies (gcb) material in the course of nuclear fragmentation of secondary giant trophoblast cells resulting in polykaryocyte formation at the late stage of their differentiation. a simultaneous dna cytophotometry in gcbs and nuclear fragments showed a progressive gcb dna content decrease proportional to that of dna content in nuclear fragments. dna contents in the nuclear fragments corresponded to 2c, 4c and 8c. in ...	2005	16711385
effect of photoperiod on body mass, food intake and body composition in the field vole, microtus agrestis.	many small mammals respond to seasonal changes in photoperiod by altering body mass and adiposity. these animals may provide valuable models for understanding the regulation of energy balance. here, we present data on the field vole (microtus agrestis) - a previously uncharacterised example of photoperiod-induced changes in body mass. we examined the effect of increased day length on body mass, food intake, apparent digestive efficiency, body composition, de novo lipogenesis and fatty acid compo ...	2005	15671345
whole-genome chromosome distribution during nuclear fragmentation of giant trophoblast cells of microtus rossiaemeridionalis studied with the use of gonosomal chromatin arrangement.	gonosomal chromatin bodies (gcbs), i.e. blocks of condensed chromatin consisting of heterochromatized region of the sex chromosomes of the field vole m. rossiaemeridionalis, were used as a natural interphase chromosome marker in order to clarify the regularities of gcb rearrangement during nuclear fragmentation of secondary giant trophoblast cells (sgtcs) at the end of their differentiation. cytophotometrical measurements of dna content in the nuclei, nuclear fragments and simultaneously in the ...	2005	16314124
apoptosis-related factors (fas receptor, fas ligand, fadd) in early tooth development of the field vole (microtus agrestis).	fas (cd95/apo-1) belongs to the tnf receptor (tnfr) family. fas ligand binding followed by fas-receptor oligomerisation leads to formation of a death-inducing signal complex starting with recruitment of the fas-adapter protein (fadd). components of this initiation complex (fas, fas-l, fadd) were correlated with apoptotic cells, detected by specific dna fragmentation and morphological criteria. apoptotic cells can be detected throughout the embryonic development of molar teeth. restricted temporo ...	2005	15721145
trypanosomes, fleas and field voles: ecological dynamics of a host-vector--parasite interaction.	to investigate the prevalence of a flea-borne protozoan (trypanosoma (herpetosoma) microti) in its field vole (microtus agrestis) host, we monitored over a 2-year period a range of intrinsic and extrinsic parameters pertaining to host demographics, infection status and vector (flea) prevalence. generalized linear mixed modelling was used to analyse patterns of both flea and trypanosome occurrence. overall, males of all sizes and ages were more likely to be infested with fleas than their female c ...	2005	16178357
analysis of sex-linked sequences supports a new mammal species in europe.	european mammals have been the focus of particularly detailed taxonomic studies by traditional morphological methods. however, dna analyses have the potential to reveal additional, cryptic species. we describe two highly divergent evolutionary lineages within a small eurasian mammal, the field vole (microtus agrestis). we show that the two lineages can be detected not only with maternally (mitochondrial dna), but also with paternally (y chromosome) and biparentally (x chromosome) inherited dna s ...	2005	15910324
predator-induced synchrony in population oscillations of coexisting small mammal species.	comprehensive analyses of long-term (1977-2003) small-mammal abundance data from western finland showed that populations of microtus voles (field voles m. agrestis and sibling voles m. rossiaemeridionalis) voles, bank (clethrionomys glareolus) and common shrews (sorex araneus) fluctuated synchronously in 3 year population cycles. time-series analyses indicated that interspecific synchrony is influenced strongly by density-dependent processes. synchrony among microtus and bank voles appeared addi ...	2005	15695211
relationship between vestibular lamina, dental lamina, and the developing oral vestibule in the upper jaw of the field vole (microtus agrestis, rodentia).	formation of the oral vestibule is ignored in most studies on tooth development, although dental and vestibular lamina are closely related to each other. knowledge about morphogenetic processes shaping the oral vestibule is missing almost completely. the aim of this study was to assess the developmental relationship between dental and vestibular lamina as well as formation of the oral vestibule in the upper jaw of the field vole (microtus agrestis), a small rodent representing an attractive mode ...	2005	16025539
sheep grazing and rodent populations: evidence of negative interactions from a landscape scale experiment.	inter-specific competition, facilitation and predation influence herbivore assemblages, but no study has experimentally explored the interactions between large ungulates and small rodents. in a fully replicated, landscape scale experiment, we manipulated densities of domestic sheep in mountain pastures in norway. we then determined population growth and densities of rodents by live trapping in each of the areas with different sheep densities. we found that the (summer) population growth rate and ...	2005	15726430
caspase 3 activation in the primary enamel knot of developing molar tooth.	mammalian teeth develop during embryogenesis as epithelio-mesenchymal organs. the primary enamel knot is considered as a signaling center in tooth morphogenesis. after tooth bell formation, this epithelial structure undergoes apoptosis. activation of caspase 3 represents a crucial step in the intracellular death machinery. procaspase 3 and caspase 3 molecules were localized in the primary enamel knot of the field vole using immunohistochemistry. different fixation procedures in cryopreserved and ...	2006	15910164
sympatric ixodes trianguliceps and ixodes ricinus ticks feeding on field voles (microtus agrestis): potential for increased risk of anaplasma phagocytophilum in the united kingdom?	the importance of wild rodents as reservoirs of zoonotic tick-borne pathogens is considered low in the united kingdom because, in studies to date, those parasitized by exophilic ixodes ricinus ticks carry almost exclusively larvae and thus have a minor role in transmission cycles. in a cross-sectional study, 11 (6.7%) of 163 field voles (microtus agrestis) captured at field sites in northern england were pcr-positive for anaplasma phagocytophilum. the voles were found to act as hosts for both la ...	2006	17187576
proliferation and apoptosis in early molar morphogenesis-- voles as models in odontogenesis.	proliferation and apoptosis play crucial roles in the development of multicellular organisms. their precise balance is necessary for tissue homeostasis throughout life. the developing dentition is a suitable model to study proliferation and apoptosis during embryogenesis, but the corresponding studies have been carried out principally in the mouse. the present study aimed to examine proliferation and apoptosis in the vole (microtus sp., rodentia) during the early morphogenesis of the first upper ...	2006	16586349
diabetes and myocarditis in voles and lemmings at cyclic peak densities--induced by ljungan virus?	although it is well-documented from theoretical studies that pathogens have the capacity to generate cycles, the occurrence and role of pathogens and disease have been poorly empirically studied in cyclic voles and lemmings. in screening for the occurrence of disease in cyclic vole and lemming populations, we found that a high proportion of live-trapped clethrionomys glareolus, c. rufocanus, microtus agrestis and lemmus lemmus at high collective peak density, shortly before the decline, suffered ...	2006	16868760
intraspecific competition, growth, chemistry, and susceptibility to voles in seedlings of betula pendula.	we studied the effects of the intensity of intraspecific competition, as indicated by seedling density, and competitive success within populations, as indicated by seedling size, on the secondary chemistry of the stems of silver birch seedlings and their palatability to field voles. we found that the size of seedlings and their total phenolic concentrations were inversely related to stand density. voles, however, did not discriminate between seedlings grown at the densities studied. variation in ...	2006	17001532
cowpox virus infection in natural field vole microtus agrestis populations: delayed density dependence and individual risk.	1. little is known about the dynamics of pathogen (microparasite) infection in wildlife populations, and less still about sources of variation in the risk of infection. here we present the first detailed analysis of such variation. 2. cowpox virus is an endemic sublethal pathogen circulating in populations of wild rodents. cowpox prevalence was monitored longitudinally for 2 years, in populations of field voles exhibiting multiannual cycles of density in kielder forest, uk. 3. the probability th ...	2006	17032374
a role for vector-independent transmission in rodent trypanosome infection?	within host-pathogen systems where vector-borne transmission is the primary route of infection, little or no attention has been paid to the relative importance of secondary or alternative routes of transmission. here, by contrast, we report the results from a controlled longitudinal field-scale experiment in which the prevalence of fleas (siphonaptera) was manipulated and the occurrence and distribution of a flea-borne protozoan (trypanosoma (herpetosoma) microti) in a natural field vole (microt ...	2006	16876803
vole population cycles in northern and southern europe: is there a need for different explanations for single pattern?	1. students of population cycles in small rodents in fennoscandia have accumulated support for the predation hypothesis, which states that the gradient in cycle length and amplitude running from southern to northern fennoscandia reflects the relative influence of specialist and generalist predators on vole dynamics, itself modulated by the presence of snow cover. the hypothesized role of snow cover is to isolate linked specialist predators, primarily the least weasel, mustela n. nivalis l. and t ...	2006	16637987
delayed density-dependent season length alone can lead to rodent population cycles.	studies of cyclic microtine populations (voles and lemmings) have suggested a relationship between the previous year's population density and the subsequent timing of the onset of reproduction by overwintered breeding females. no studies have explored the importance of this relationship in the generation of population cycles. here we mathematically examine the implications of variation in reproductive season length caused by delayed density-dependent changes in its start date. we demonstrate tha ...	2006	16671013
changes over time in the spatiotemporal dynamics of cyclic populations of field voles (microtus agrestis l.).	we demonstrate changes over time in the spatial and temporal dynamics of an herbivorous small rodent by analyzing time series of population densities obtained at 21 locations on clear cuts within a coniferous forest in britain from 1984 to 2004. changes had taken place in the amplitude, periodicity, and synchrony of cycles and density-dependent feedback on population growth rates. evidence for the presence of a unidirectional traveling wave in rodent abundance was strong near the beginning of th ...	2006	16671000
incomplete sister chromatid separation of long chromosome arms.	chromosome segregation ensures the equal partitioning of chromosomes at mitosis. however, long chromosome arms may pose a problem for complete sister chromatid separation. in this paper we report on the analysis of cell division in primary cells from field vole microtus agrestis, a species with 52 chromosomes including two giant sex chromosomes. dual chromosome painting with probes specific for the x and the y chromosomes showed that these long chromosomes are prone to mis-segregate, producing d ...	2006	17021850
artificial reproduction of the yangtze field vole: in vitro embryo development and fertilization with fresh and freeze-thawed sperm.	several research groups are using the yangtze field vole as a model for studying schistosome infection, but relatively little is known about the species's reproductive physiology. the authors examined the vole's in vivo and in vitro embryonic development as well as the efficacy of in vitro fertilization using either fresh or cryopreserved sperm to breed these rodents.	2006	16943792
experimental demonstration of the antiherbivore effects of silica in grasses: impacts on foliage digestibility and vole growth rates.	the impact of plant-based factors on the population dynamics of mammalian herbivores has been the subject of much debate in ecology, but the role of antiherbivore defences in grasses has received relatively little attention. silica has been proposed as the primary defence in grasses and is thought to lead to increased abrasiveness of foliage so deterring feeding, as well as reducing foliage digestibility and herbivore performance. however, at present there is little direct experimental evidence ...	2006	16928631
photoperiod regulates leptin sensitivity in field voles, microtus agrestis.	we have previously shown that cold-acclimated (8 degrees c) male field voles (microtus agrestis) transferred from short (sd, 8:16 h l:d) to long photoperiod (ld, 16:8 h l:d) exhibit increases in body mass, adiposity and food intake. to assess whether these increases were associated with decreased leptin sensitivity, we infused ld and sd voles with physiological doses of murine leptin (or saline) delivered peripherally for 7 days via mini-osmotic pumps. measurements were made of body mass (weight ...	2006	16402185
regulation of body mass and adiposity in the field vole, microtus agrestis: a model of leptin resistance.	adult mammals are typically highly resistant to perturbations in their energy balance. in obese humans, however, this control appears to be lost. apart from a few exceptional cases, this loss of control occurs despite appropriate levels of circulating leptin -- suggesting that elevated adiposity may be a consequence of failure to respond to the leptin signal: leptin resistance. when cold-acclimated male field voles (microtus agrestis) are transferred from short (sd, 8 h light) to long (ld, 16 h ...	2007	17283227
costs of coexistence along a gradient of competitor densities: an experiment with arvicoline rodents.	1. costs of coexistence for species with indirect resource competition usually increase monotonically with competitor numbers. very little is known though about the shape of the cost function for species with direct interference competition. 2. here we report the results of an experiment with two vole species in artificial coexistence in large enclosures, where density of the dominant competitor species (microtus agrestis) was manipulated. experimental populations of the subordinate vole species ...	2007	17184354
altered expression of socs3 in the hypothalamic arcuate nucleus during seasonal body mass changes in the field vole, microtus agrestis.	we have previously shown that cold-acclimated (8 degrees c) male field voles (microtus agrestis) transferred from short day (sd, 8 h light) to long day (ld, 16 h light) photoperiod exhibit an increase in body mass lasting 4 weeks, after which they stabilise at a new plateau approximately 7.5 g (24.8%) higher than animals maintained in sd. by infusing voles with exogenous leptin, we have also demonstrated that sd voles respond to the hormone by reducing body mass and food intake, whereas ld anima ...	2007	17214870
ultradian rhythms and the nutritional importance of caecotrophy in captive brandt's voles (lasiopodomys brandtii).	ingestion of soft faeces derived from caecal contents, caecotrophy, in herbivorous small mammals is considered an adaptation to the metabolic disadvantage of small body size, especially when feeding on diets of low quality. we investigated daily activity patterns in captive brandt's voles (lasiopodomys brandtii), including feeding, locomotion, caecotrophy, and defaecation, by continuous 24 h visual observation; and estimated the contribution of soft faeces ingestion (caecotrophy) to intake of pr ...	2007	17211665
contrasting dynamics of bartonella spp. in cyclic field vole populations: the impact of vector and host dynamics.	many zoonotic disease agents are transmitted between hosts by arthropod vectors, including fleas, but few empirical studies of host-vector-microparasite dynamics have investigated the relative importance of hosts and vectors. this study investigates the dynamics of 4 closely related bartonella species and their flea vectors in cyclic populations of field voles (microtus agrestis) over 3 years. the probability of flea infestation was positively related to field vole density 12 months previously i ...	2007	17096870
dioxin exposure in contaminated sawmill area: the use of molar teeth and bone of bank vole (clethrionomys glareolus) and field vole (microtus agrestis) as biomarkers.	developmental disorders of teeth are among the most sensitive targets of polychlorinated dibenzo-p-dioxin and -furan (pcdd/f) exposure. in rats, 2,3,7,8-tetrachlorodibenzo-p-dioxin (tcdd) reduces dose-dependently the size of molars, most severely the third lower molars. dioxins also have effects on developing bone, including altered bone mineral density as well as reduced bending breaking force and stiffness. the aim of this study was to evaluate the use of the third lower molar and long bones a ...	2007	17335869
chromosomal evolution of arvicolinae (cricetidae, rodentia). i. the genome homology of tundra vole, field vole, mouse and golden hamster revealed by comparative chromosome painting.	cross-species chromosome painting has become the mainstay of comparative cytogenetic and chromosome evolution studies. here we have made a set of chromosomal painting probes for the field vole (microtus agrestis) by dop-pcr amplification of flow-sorted chromosomes. together with painting probes of golden hamster (mesocricetus auratus) and mouse (mus musculus), the field vole probes have been hybridized onto the metaphases of the tundra vole (microtus oeconomus). a comparative chromosome map betw ...	2007	17497247
chromosomal evolution of arvicolinae (cricetidae, rodentia). ii. the genome homology of two mole voles (genus ellobius), the field vole and golden hamster revealed by comparative chromosome painting.	using cross-species chromosome painting, we have carried out a comprehensive comparison of the karyotypes of two ellobius species with unusual sex determination systems: the transcaucasian mole vole, ellobius lutescens (2n = 17, x in both sexes), and the northern mole vole, ellobius talpinus (2n = 54, xx in both sexes). both ellobius species have highly rearranged karyotypes. the chromosomal paints from the field vole (microtus agrestis) detected, in total, 34 and 32 homologous autosomal regions ...	2007	17924201
prevalence of toxoplasma gondii in small mammals from the ardennes region, france.	serum samples from 218 small mammals trapped in forest and grassland in the ardennes region (north-eastern france) were tested for antibodies to toxoplasma gondii. using the modified agglutination test, positive results were found in 4/92 apodemus sp., 3/64 clethrionomys glareolus, 0/26 microtus agrestis, 0/4 micromys minutus, 3/5 sorex sp., 2/9 arvicola terrestris, and 7/18 talpa europaea. toxoplasma gondii was not isolated from the heart of seropositive individuals after bioassay in mice. sero ...	2007	18303774
sensitivity to assumptions in models of generalist predation on a cyclic prey.	ecological theory predicts that generalist predators should damp or suppress long-term periodic fluctuations (cycles) in their prey populations and depress their average densities. however, the magnitude of these impacts is likely to vary depending on the availability of alternative prey species and the nature of ecological mechanisms driving the prey cycles. these multispecies effects can be modeled explicitly if parameterized functions relating prey consumption to prey abundance, and realistic ...	2007	18027760
a new whipworm from arvicolid rodents, trichuris arvicolae feliu et al., 2000, in the helminth fauna of poland.	during the parasitological examination of wild rodents from the vicinity of wrocław a single whipworm female was isolated from a field vole microtus agrestis. the nematode was determined as trichuris arvicolae. this is the first report of this parasite in poland.	2007	18441882
bovine tuberculosis infection in wild mammals in the south-west region of england: a survey of prevalence and a semi-quantitative assessment of the relative risks to cattle.	in the united kingdom, badgers are implicated in the transmission of mycobacterium bovis to cattle, but little information is available on the potential role of other wild mammals. this paper presents the results of the largest systematic uk survey of m. bovis infection in other wild mammals. mammal carcasses (4715) from throughout the south-west region of england were subjected to a systematic post mortem examination, microbiological culture of tissues and spoligotyping of isolates. infection w ...	2007	16434219
cowpox virus infection in natural field vole microtus agrestis populations: significant negative impacts on survival.	1. cowpox virus is an endemic virus circulating in populations of wild rodents. it has been implicated as a potential cause of population cycles in field voles microtus agrestis l., in britain, owing to a delayed density-dependent pattern in prevalence, but its impact on field vole demographic parameters is unknown. this study tests the hypothesis that wild field voles infected with cowpox virus have a lower probability of survival than uninfected individuals. 2. the effect of cowpox virus infec ...	2008	18177331
consumption of grass endophytes alters the ultraviolet spectrum of vole urine.	fungal endophytes of grasses are known to benefit their hosts directly by increasing resistance to herbivores through mycotoxins. we propose and test assumptions of a novel hypothesis according to which fungal endophytes of grasses may benefit their hosts also indirectly by increasing the conspicuousness of a mammalian herbivore, the field vole (microtus agrestis), to its avian predators by enhancing the ultraviolet visibility of vole urine. we found that field voles feeding on endophyte-infecte ...	2008	18274778
parasite interactions in natural populations: insights from longitudinal data.	the physiological and immunological state of an animal can be influenced by current infections and infection history. consequently, both ongoing and previous infections can affect host susceptibility to another parasite, the biology of the subsequent infection (e.g. infection length) and the impact of infection on host morbidity (pathology). in natural populations, most animals will be infected by a succession of different parasites throughout the course of their lives, with probably frequent co ...	2008	18474121
prion protein amino acid determinants of differential susceptibility and molecular feature of prion strains in mice and voles.	the bank vole is a rodent susceptible to different prion strains from humans and various animal species. we analyzed the transmission features of different prions in a panel of seven rodent species which showed various degrees of phylogenetic affinity and specific prion protein (prp) sequence divergences in order to investigate the basis of vole susceptibility in comparison to other rodent models. at first, we found a differential susceptibility of bank and field voles compared to c57bl/6 and wo ...	2008	18654630
disease effects on reproduction can cause population cycles in seasonal environments.	1. recent studies of rodent populations have demonstrated that certain parasites can cause juveniles to delay maturation until the next reproductive season. furthermore, a variety of parasites may share the same host, and evidence is beginning to accumulate showing nonindependent effects of different infections. 2. we investigated the consequences for host population dynamics of a disease-induced period of no reproduction, and a chronic reduction in fecundity following recovery from infection (s ...	2008	18005128
tuberculosis (mycobacterium microti) in wild field vole populations.	vole tuberculosis (tb; mycobacterium microti) is an understudied endemic infection. despite progressing slowly, it causes severe clinical pathology and overt symptoms in its rodent host. tb was monitored for 2 years in wild field voles in kielder forest, uk. the prevalence of characteristic cutaneous tb lesions was monitored longitudinally at 4 sites, with individuals live-trapped and repeatedly monitored. a prevalence of 5.2% of individuals with lesions was recorded (n=2791). in a cross-section ...	2008	18005472
relative importance of ixodes ricinus and ixodes trianguliceps as vectors for anaplasma phagocytophilum and babesia microti in field vole (microtus agrestis) populations.	the importance of ixodes ricinus in the transmission of tick-borne pathogens is well recognized in the united kingdom and across europe. however, the role of coexisting ixodes species, such as the widely distributed species ixodes trianguliceps, as alternative vectors for these pathogens has received little attention. this study aimed to assess the relative importance of i. ricinus and i. trianguliceps in the transmission of anaplasma phagocytophilum and babesia microti among united kingdom fiel ...	2008	18820068
fine structure of the mandibular gland in japanese field vole (microtus montebelli).	the mandibular glands of the japanese field vole were examined by light microscopy, and transmission and scanning electron microscopies. the acinar cells contained light and coarse secretory granules, and reacted with pas and stained slightly with ab; they were considered to be seromucous in nature. the acinar epithelium was composed of light and dark cells containing many secretory granules. the intercalated duct cells consisted of light cells possessing a few dense granules. a few cytoplasmic ...	2008	3542536
voles on small islands: effects of food limitation and alien predation.	ecosystems of three trophic levels may be bottom-up (by food-plant availability) and/or top-down (by predators) limited. top-down control might be of greater consequence when the predation impact comes from an alien predator. we conducted a replicated two-factor experiment with field voles (microtus agrestis) during 2004-2005 on small islands of the outer archipelago of the baltic sea, south-west finland, manipulating both predation impact by introduced american mink (mustela vison) and winter f ...	2008	18607635
the dynamics of health in wild field vole populations: a haematological perspective.	1. pathogens have been proposed as potentially important drivers of population dynamics, but while a few studies have investigated the impact of specific pathogens, the wealth of information provided by general indices of health has hardly been exploited. by evaluating haematological parameters in wild populations, our knowledge of the dynamics of health and infection may be better understood. 2. here, haematological dynamics in natural populations of field voles are investigated to determine en ...	2008	18564292
are silica defences in grasses driving vole population cycles?	understanding the factors that drive species population dynamics is fundamental to biology. cyclic populations of microtine rodents have been the most intensively studied to date, yet there remains great uncertainty over the mechanisms determining the dynamics of most of these populations. for one such population, we present preliminary evidence for a novel mechanism by which herbivore-induced reductions in plant quality alter herbivore life-history parameters and subsequent population growth. w ...	2008	18482904
poor condition and infection: a vicious circle in natural populations.	pathogens may be important for host population dynamics, as they can be a proximate cause of morbidity and mortality. infection dynamics, in turn, may be dependent on the underlying condition of hosts. there is a clear potential for synergy between infection and condition: poor condition predisposes to host infections, which further reduce condition and so on. to provide empirical data that support this notion, we measured haematological indicators of infection (neutrophils and monocytes) and co ...	2008	18448414
azurocytes in wild field voles: factors associated with their occurrence.	the occurrence of azurocytes (az), a type of leukocyte unique to voles and previously described for three microtus species, is now reported in microtus agrestis. the goal of this study was to shed new light on the possible function and significance of these cells and on how they play a role in the natural history of rodent species. individuals from three vole populations were sampled monthly for 2 years. a hemogram was produced for each individual, and az counts estimated. the counts of az were ...	2008	18704584
the impact of experimentally elevated energy expenditure on oxidative stress and lifespan in the short-tailed field vole microtus agrestis.	life-history theory assumes that animal life histories are a consequence of trade-offs between current activities and future reproductive performance or survival, because resource supply is limited. empirical evidence for such trade-offs in the wild are common, yet investigations of the underlying mechanisms are rare. life-history trade-offs may have both physiological and ecological mediated costs. one hypothesized physiological mechanism is that elevated energy metabolism may increase reactive ...	2008	18467297
predation and fragmentation portrayed in the statistical structure of prey time series.	statistical autoregressive analyses of direct and delayed density dependence are widespread in ecological research. the models suggest that changes in ecological factors affecting density dependence, like predation and landscape heterogeneity are directly portrayed in the first and second order autoregressive parameters, and the models are therefore used to decipher complex biological patterns. however, independent tests of model predictions are complicated by the inherent variability of natural ...	2009	19419539
endopolyploidization and the interstitial invasion of the supergiant trophoblast cells of the field vole microtus rossiaemeridionalis.	the supergiant trophoblast cells characteristic of vole placenta prove to be highly invasive being found at the boundary of the decidualized endometrium and myometrium. their size (100 microm and higher) suggests them to be highly polyploid, though their ploidy was not determined by now. we performed determination of the ploidy level of the supergiant trophoblast cells (sugt) in order to verify whether the highly polyploid trophoblast cells are capable of deep intrauterine invasion. anti-cytoker ...	2009	19329135
the effects of spatial and temporal heterogeneity on the population dynamics of four animal species in a danish landscape.	variation in carrying capacity and population return rates is generally ignored in traditional studies of population dynamics. variation is hard to study in the field because of difficulties controlling the environment in order to obtain statistical replicates, and because of the scale and expense of experimenting on populations. there may also be ethical issues. to circumvent these problems we used detailed simulations of the simultaneous behaviours of interacting animals in an accurate facsimi ...	2009	19549327