bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impaired Reproduction of Histamine Deficient (histidine‐decarboxylase Knockout) Mice is Caused Predominantly by a Decreased Male Mating Behavior
Authors: Pár Gabriella , Szekeres‐Barthó Júlia , Buzás Edit , Pap Erna , Falus András 
Published: July 2003

PROBLEM: Histamine induces a Th2 shift. As successful allopregnancy is characterized by a peripheral Th2 dominance, we investigated the role of histamine in reproduction.METHOD OF STUDY: HDC knockout (HDC−/−) or wild‐type (HDC+/+) mice kept on histamine‐deficient or normal diet were mated. Appearance of vaginal plugs indicated day 0.5 of pregnancy. On day 10.5 uteri were inspected. Splenic IFN‐γ production and cytotoxic activity were determined.RESULTS: In HDC+/+ or HDC−/− females on normal diet, plugs appeared between 3 and 6 days. In 80% of the (HDC−/−)/(HDC−/−) matings on histamine‐deficient diet, no vaginal plugs were observed for more than 1 month. After replacing males with the wild type, plugs appeared within 3 days. In HDC−/− mice, litter size was lower than in HDC+/+ animals. Cytotoxicity and IFN‐γ production were significantly increased in non‐pregnant histamine‐deficient mice, but not in pregnant mice.CONCLUSION: Histamine affects male mating behavior, but is not indispensable for successful pregnancy.
Immunization of Naïve Mice with Mouse Laminin‐1 Affected Pregnancy Outcome in a Mouse Model
Authors: Matalon Shelly Tartakover , Blank Miri , Matsuura Eiji , Inagaki Junko , Nomizu Motoyoshi , Levi Yair , Koike Takao , Shere Yaniv , Ornoy Asher , Shoenfeld Yehuda 
Published: July 2003

PROBLEM: Laminins have important roles during placental and embryonic development. The aim of our study was to determine if active immunization of mice with laminin‐1 could elicit an autoimmune response, and induce features of reproductive failure.METHOD OF STUDY: BALB/c mice were immunized with mouse laminin‐1. Autoantibodies to laminin‐1 were measured by enzyme‐linked immunosorbent assay. Pregnant mice were killed on day 14 of pregnancy and examined for pregnancy outcome.RESULTS: Mice immunized with laminin‐1 developed elevated levels of anti‐laminin‐1 auto‐antibodies contrary to the control group. A higher fetal resorption rate was found in the laminin‐1 immunized group (23.8%) compared with that of the control group (12.2%), and was even higher in the subgroup of those animals with very high levels of anti‐laminin‐1 (P < 0.01). Laminin‐1 immunized mice also had lower fetal and placental weights.CONCLUSIONS: Active immunization with laminin‐1 followed by elevated circulating anti‐laminin‐1 antibodies results in reproductive failure manifested by a higher fetal resorption rate.
Effects of Sera from Infertile Women with Sperm Immobilizing Antibodies on Fertilization and Embryo Development In Vitro in Mice
Authors: Taneichi Akiyo , Shibahara Hiroaki , Takahashi Kazuko , Sasaki Shino , Kikuchi Kumiko , Sato Ikuo , Yoshizawa Midori 
Published: July 2003

PROBLEM: This study was performed to investigate if patients’ sera with anti‐human sperm antibodies show inhibitory effects on in vitro fertilization (IVF) and embryo development in mice.METHOD OF STUDY: Patients’ sera were collected from eight infertile women having sperm immobilizing antibodies and 17 infertile women without the antibodies. Male ICR mice and female F1 mice (BALB/c X C57BL/6J) were used. In mouse IVF, pre‐incubated sperm were cultured in the medium containing patient's serum with or without sperm immobilizing antibodies, or bovine serum albumin (BSA) as a control. The fertilization rates and the incidences of blastocyst formation were compared.RESULTS: A mouse sperm immobilization test was established. Five (62.5%) of eight serum samples with sperm immobilizing antibodies and nine (52.9%) of 17 serum samples without the antibodies showed sperm immobilizing activities in mice. There was no significant difference between the two groups. Five sera with sperm immobilizing activities in human and mice, and five sera without sperm immobilizing activities in human or mice were used for the further experiments. The fertilization rates in BSA, patient's serum with sperm immobilizing antibodies, and that without the antibodies were 82.5% (746/904), 43.6% (508/1165), and 64.5% (669/1037), respectively. There were significant differences between the groups. The incidences of blastocyst formation were 59.9% (447/746), 31.7% (161/508), and 47.7% (319/669), respectively. There were also significant differences between the groups.CONCLUSIONS: Some of the patient's serum with and without sperm immobilizing antibodies could immobilize sperm with complement. However, as compared with control, sera with sperm immobilizing activities against human and mouse sperm significantly blocked IVF and inhibited embryo development in mice. Further studies are required to investigate the mechanisms of the blocking effects of antisperm antibodies on fertilization and embryo development using the mouse model.
Germ Cell Apoptosis in Autoimmune Orchitis: Involvement of the Fas–FasL System
Authors: Theas Susana , Rival Claudia , Lustig Livia 
Published: July 2003

PROBLEM: The aim of this study was to determine the mechanism of germ cell death in experimental autoimmune orchitis (EAO) and the involvement of the Fas–FasL system in this process.METHOD OF STUDY: The EAO was induced in rats by immunization with testis homogenate and adjuvants. Apoptosis was studied by light microscopy, in situ end labeling of apoptotic DNA and DNA fragmentation techniques. Fas, FasL and caspase 3 expression was detected by immunohistochemistry.RESULTS: In rats with orchitis the number of Fas+ and FasL+ apoptotic germ cells increased from day 50, when the lesion develops, to 150 days, and correlates with the degree of testicular damage. Most spermatocytes expressing Fas were apoptotic. Many Fas+ germ cells were also immunoreactive for FasL. Moreover, these cells also expressed caspase 3.CONCLUSIONS: In rats with EAO germ cell death occurs through an apoptotic mechanism preceding germ cell sloughing. Immunohistochemical data suggest that the Fas–FasL system mediates germ cell apoptosis in an autocrine and/or paracrine way.
Effect of harvest date on the chemical composition and nutritive value of Cerastium holosteoides
Authors: Kramberger B. , Klemenčič S. 
Published: July 2003

Abstract Cerastium holosteoides is a short‐lived plant often found in small proportions on dry and mesotropic semi‐natural, species‐rich grassland communities. To obtain more information about its nutritive value, two experiments on Arrhenatheretum elatioris grassland were carried out to examine the effect of harvest date on in vitro organic matter digestibility (IVOMD), neutral‐detergent fibre (NDF), acid‐detergent fibre (ADF), acid‐detergent lignin (ADL), estimated net energy for lactation (NEL) and crude protein (CP) concentrations of C. holosteoides, and selection of this plant by dairy cows grazing on semi‐natural grassland. C. holosteoides starts flowering in spring and continuously develops new flowers on new branches throughout the summer. Harvests were made in relation to particular growth stages of Dactylis glomerata present in the sward: (A) tillering; (B) stem elongation; (C) ear emergence; (D) flowering; and (E) ripening.Chemical composition and nutritive value were evaluated in 1998 and 1999. With advancing maturity, IVOMD of C. holosteoides decreased from 0·771 at growth stage A to 0·485 at growth stage E. At the same time, CP concentration decreased from 153 to 69 g kg−1 dry matter (DM) and estimated NEL concentration from 6·00 to 4·07 MJ kg−1 DM. With advancing maturity, there was a significant increase in NDF, ADF and ADL concentrations. In the summer harvest season, C. holosteoides contained significantly higher NDF, ADF and ADL concentrations, lower NEL concentration and had a lower IVOMD value than in the spring. Differences between years were also found for IVOMD and for NDF, ADF, ADL and NEL concentrations.In a grazing experiment in the year 1999, at growth stage B, Simmental cows grazed an A. elatioris sward in which the main species was D. glomerata (0·092), and the proportion of C. holosteoides was 0·034. C. holosteoides was, on average, grazed by cows to the same relative extent as other species in the sward.
The effect of concentrate feed level on the response of lactating dairy cows to a constant proportion of fodder beet inclusion in a grass silage‐based diet
Authors: Ferris C. P. , Patterson D. C. , Gordon F. J. , Kilpatrick D. J. 
Published: July 2003

Abstract The effects of level of concentrate supplementation on the response of dairy cows to grass silage‐based diets containing a constant proportion of fodder beet were examined. Forty Holstein‐Friesian dairy cows of mixed parity were used in a 2 × 5 factorial design experiment. Two basal diet types [grass silage alone or grass silage mixed with fodder beet in a 70:30 dry matter (DM) ratio] were offered ad libitum, and the effects of five levels of concentrate supplementation (mean = 3·0, 5·3, 7·5, 9·8 and 12·0 kg DM per cow d−1) were examined. Concentrate supplements were offered via an out‐of‐parlour feeding system. These treatments were examined in a three‐period (period length = 4 weeks) partially balanced changeover design experiment.Fodder beet inclusion had no significant effect on the estimated metabolizable energy (ME) concentration of the ration (P > 0·001). Total DM intake, estimated ME intake, milk yield, milk protein content and milk energy output all showed significant linear increases with increasing level of concentrate inclusion (P < 0·001) while, in addition, milk yield and milk energy output exhibited a significant quadratic increase (P < 0·01). The inclusion of fodder beet in the diet reduced silage DM intake (P < 0·01) but resulted in an increase in total DM intake and estimated ME intake (P < 0·001). However, inclusion of fodder beet had no significant effect on milk yield (P > 0·05), while increasing milk protein content and milk energy output (P ≤ 0·05). Milk energy output, as a proportion of estimated ME intake, was significantly (P < 0·001) reduced by fodder beet inclusion (0·44 vs. 0·38).Despite large increases in estimated ME intake with the inclusion of fodder beet at all levels of concentrate supplementation, milk energy output responses were small, resulting in an overall reduction in the efficiency of conversion of ME intake into milk energy output. An increased partitioning of dietary ME intake to tissue gain is suggested as the most likely explanation for the observations made.
Behavioural responses to habitat patch boundaries restrict dispersal and generate emigration–patch area relationships in fragmented landscapes
Authors: Schtickzelle Nicolas , Baguette Michel 
Published: July 2003

SummaryWe studied the consequences of behaviour at habitat patch boundaries on dispersal for the bog fritillary butterflyProclossiana eunomiaEsper in two networks of habitat differing in fragmentation and matrix quality. We tested for differences in responses to patch boundaries according to the fragmentation level of the network by analysing movement paths of adult butterflies.Butterflies systematically engaged in U‐turns when they reached a boundary in the fragmented network while they crossed over boundaries in more than 40% of boundary encounters in the continuous one.We applied the Virtual Migration model (Hanski, Alho & Moilanen 2000) to capture–mark–recapture data collected in both networks. The model indicated (i) a lower dispersal rate and (ii) a lower survival during dispersal in the fragmented network. This latter difference is likely to be the key biological process leading to behavioural avoidance of patch boundary crossings.On the basis of this behavioural difference, we designed an individual‐based simulation model to explore the relationship between patch area, boundary permeability and emigration rate.Predictions of the model fitted observed results of the effect of patch area on emigration rate according to fragmentation: butterflies are more likely to leave small patches than large ones in fragmented landscapes (where patch boundary permeability is low), while this relationship disappears in more continuous landscapes (where patch boundary permeability is high).
Density‐dependent mortality is mediated by foraging activity for prey fish in whole‐lake experiments
Authors: Biro Peter A. , Post John R. , Parkinson Eric A. 
Published: July 2003

SummaryWhereas the effects of density‐dependent growth and survival on population dynamics are well‐known, mechanisms that give rise to density dependence in animal populations are not well understood. We tested the hypothesis that the trade‐off between growth and mortality rates is mediated by foraging activity and habitat use. Thus, if depletion of food by prey is density‐dependent, and leads to greater foraging activity and risky habitat use, then visibility and encounter rates with predators must also increase.We tested this hypothesis by experimentally manipulating the density of young rainbow trout (Oncorhynchus mykiss) at risk of cannibalism, in a replicated single‐factor experiment using eight small lakes, during an entire growing season.We found no evidence for density‐dependent depletion of daphnid food in the nearshore refuge where most age‐0 trout resided. Nonetheless, the proportion of time spent moving by individual age‐0 trout, the proportion of individuals continuously active, and use of deeper habitats was greater in high density populations than in low density populations. Differences in food abundance among lakes had no effect on measures of activity or habitat use.Mortality of age‐0 trout over the growing season was higher in high density populations, and in lakes with lower daphnid food abundance. Therefore, population‐level mortality of age‐0 trout is linked to greater activity and use of risky habitats by individuals at high densities. We suspect that food resources were depleted at small spatial and temporal scales not detected by our plankton sampling in the high density treatment, because food‐dependent activity and habitat use by age‐0 trout occurs in our lakes when food abundance is experimentally manipulated (Biro, Post & Parkinson, in press).
How predictable are aphid population responses to elevated CO2?
Authors: Newman J. A. , Gibson D. J. , Parsons A. J. , Thornley J. H. M. 
Published: July 2003

SummaryExperiments investigating the population responses of aphids to CO2 enrichment have yielded results suggesting that aphid populations will be both larger under elevated CO2 and that they will be smaller under elevated CO2. Most studies have failed to reject the null hypothesis of no difference in population sizes due to atmospheric CO2 concentration. This diversity of results has led some investigators to conclude that aphid responses are not general, and that every aphid–plant interaction may be unique and unpredictable a priori. We use a single, general, mathematical model to consider the population responses of cereal aphids to grass grown under different CO2 concentrations.The model shows that it is possible to explain any of the three observed results: larger populations, smaller populations, or no difference, and that which of these three outcomes arises may depend critically on the interaction between aphid nitrogen requirements and the nitrogen fertility of the soil. The model also shows that the qualitative results will depend on how sensitive the aphid species is to increases in its own density. Past studies have shown that aphids increase their production of winged offspring in response to increasing aphid density. The model predicts that, in general, aphid species that have lower nitrogen requirements and that are less sensitive to their own density will be more likely to have larger populations in elevated CO2 compared to ambient CO2.Differences between aphid species (and clones) in their nitrogen requirements and the strength of their density‐dependent response have not been widely reported in the literature. Also, the nitrogen fertility of the soil has rarely been manipulated in experiments on aphid responses to rising CO2 levels. The model suggests that the diversity of population responses of aphids may be both understandable and predictable in the context of such an interaction.
Transience, dispersal and survival rates in newt patchy populations
Authors: Perret Nadège , Pradel Roger , Miaud Claude , Grolet Odile , Joly Pierre 
Published: July 2003

SummaryThis work aims to illustrating how it is possible to measure different modalities of adult dispersal in two subdivided populations of the alpine newt (Triturus alpestris). Recent developments in capture–mark–recapture methods make it possible to estimate transience rates from individuals captured only once. In the context of subdivided newt populations, transience is assumed to express nomadic behaviour that contribute to breeding dispersal. Skeletochronology and recaptures within each pond system also made it possible to estimate emigration rates and local dispersal.Two subdivided populations of alpine newts were monitored over 4 and 5 years, respectively. Whereas population A is suspected to have been established for more than 100 years, population B was monitored when colonizing a newly created archipelago of ponds.Transience was detected in each population at similar rates (37% in population A and 35% in the population B). Annual apparent survival rates were estimated as 82% in population A vs. 33% in population B. Similarity of age structures between populations leads us to consider such low survival rates in population B as resulting from emigration. Emigration was thus negligible in population A and was estimated to reach 57·3% in population B. Conversely, high local dispersal (movements within a pond system) was detected in population A, but not in population B.Even though the causation of dispersal in newts (genetic polymorphism vs. phenotypic plasticity) remains unexplored, our study succeeded in identifying several dispersal components that could result from different selective pressures (habitat heterogeneity at different temporal scales). Experimental approaches are needed to investigate the causative bases of these traits.
Effects of climate variability on the temporal population dynamics of southern fulmars
Authors: Jenouvrier Stephanie , Barbraud Christophe , Weimerskirch Henri 
Published: July 2003

SummaryEcological and population processes are affected by large‐scale climatic fluctuations, and top predators such as seabirds can provide an integrative view on the consequences of environmental variability on ecosystems. Here, we examine the dynamics of a southern fulmar population in Antarctica over a 39‐year period and evaluate the impact of environmental variability on the life history traits of this top predator species.Between 1963 and 2002, the number of breeding pairs fluctuated between seven and 53 in relation to variations in sea ice concentration, and increased overall (annual growth rate: 1·0035). Breeding performance tended to be lower in years with low sea ice concentration. The proportion of birds attempting to breed varied strongly from one year to the next despite the birds were alive, indicating strong environmental forcing on the decision to breed. The number of new local recruits and immigrants was correlated highly with the number of local breeders, and capture probabilities were positively related to the breeding population size. Local recruitment, number of local breeders and proportion of birds attempting to breed were lower when sea ice concentration during summer was low.Adult survival between 1964 and 2002 was on average 0·923 ± 0·006, and decreased during years with high sea surface temperature and low sea ice concentration.Modelled population growth rate, estimated using matrix models, of the population was 0·9728, a difference of 3·6% compared to the observed rate of increase. This discrepancy is due probably to the immigration rate (3 ± 3%).Demographic parameters were affected by sea ice concentration and sea surface temperature anomalies, probably through an impact on krill availability, the main prey of southern fulmars. During warm anomalies, birds skip breeding probably because the food availability was low and limiting for the highly energy demanding reproductive activities.We also emphasize that demographic parameters were very low during the period 1975–80 and showed a higher variability after 1980, which could be interpreted in the context of a regime shift. Our study indicates that the southern fulmar population dynamics may be very susceptible to environmental variability. Further long‐lasting warm anomalies are likely to affect negatively their populations.
Population regulation in group‐living birds: predictive models of the Seychelles warbler
Authors: Ridley Jo , Komdeur Jan , Sutherland William J. 
Published: July 2003

SummaryA major challenge for population ecology is to predict population responses to novel conditions, such as habitat loss. This frequently involves understanding dispersal decisions, in terms of their consequences for fitness. However, this approach requires detailed data, and is thus often inappropriate for urgent problems on poorly known species. This may be resolved by developing a predictive framework based on well‐studied species, for applying to those that are less well understood.Population size, group sizes and habitat occupancy of the Seychelles warbler (Acrocephalus sechellensis) can be predicted by determining the evolutionary stable dispersal strategy. For densities near to demographic equilibrium, regulation results from the combined effects of non‐breeding and use of sink habitats.In the Seychelles warbler, resident male non‐breeders compete for breeding vacancies on neighbouring territories. The resulting kin competition is a key process for predicting the observed balance between regulation by non‐breeding and regulation by sink use. Family groups, in which offspring delay dispersal, hoping to fill a vacancy on a local territory, are common among group‐living species. This suggests that kin competition may frequently play a central role in the population regulation of socially complex species.Although all the model variants considered are complex, predictions are shown to be insensitive to a range of simplifications, illustrating that, despite significant evolutionary import at the individual level, some behaviour can be unimportant when considering population level questions. Identifying which behavioural strategies have significant demographic consequences is key to the further development of population models based on fitness maximizing behaviour.