bluuebunny/crossref_metadata_2025_split huggingface dataset:
The design of complex sexual traits in male barn swallows: associations between signal attributes
Authors: Garamszegi L. Z. , Hegyi G. , Heylen D. , Ninni P. , De Lope F. , Eens M. , Møller A. P. 
Published: May 2006

Abstract
Variation in the expression of sexually selected traits among individuals is widely investigated on the premise that these traits evolved to signal male quality. Significant repeatabilities of sexual signals and their associations with condition, mating success, survivorship and age may be the signatures of sexual selection. However, little is known about the relationship between these sexual attributes. Here we studied 28 acoustic and visual traits in the barn swallow, Hirundo rustica, that may potentially function in sexual selection. Based on effect sizes calculated at the between-individual level, we assessed the relationship between repeatability, condition-dependence, attractiveness, age-dependence and viability indicator value of sexual traits using sexual signals as the units of analyses. Those traits that showed high within-year repeatability also showed high between-year repeatability, indicating that between-individual variation is consistent within and among seasons. In addition, age-dependence of traits, probably causing between-year variation, was negatively related to between-year repeatability. Condition-dependence was negatively correlated with effect sizes for the extent to which traits predicted viability. Therefore, traits that are positively related to immediate condition are those that are negatively related to survival, which may be the signature of a trade-off between current and future reproductive success ultimately reflecting signal reliability. No other significant relationship was found between trait attributes. We conclude that multiple sexual signals reflect different aspects of male quality in the barn swallow.
Exploring the evolution of environmental sex determination, especially in reptiles
Authors: Janzen F. J. , Phillips P. C. 
Published: May 2006

Abstract
Environmental sex determination has been documented in a variety of organisms for many decades and the adaptive significance of this unusual sex-determining mechanism has been clarified empirically in most cases. In contrast, temperature-dependent sex determination (TSD) in amniote vertebrates, first noted 40 years ago in a lizard, has defied a general satisfactory evolutionary explanation despite considerable research effort. After briefly reviewing relevant theory and prior empirical work, we draw attention to recent comparative analyses that illuminate the evolutionary history of TSD in amniote vertebrates and point to clear avenues for future research on this challenging topic. To that end, we then highlight the latest empirical findings in lizards and turtles, as well as promising experimental results from a model organism, that portend an exciting future of progress in finally elucidating the evolutionary cause(s) and significance of TSD.
Thermal evolution of pre-adult life history traits, geometric size and shape, and developmental stability in Drosophila subobscura
Authors: Santos M. , Brites D. , Laayouni H. 
Published: May 2006

Abstract
Replicated lines of Drosophila subobscura originating from a large outbred stock collected at the estimated Chilean epicentre (Puerto Montt) of the original New World invasion were allowed to evolve under controlled conditions of larval crowding for 3.5 years at three temperature levels (13, 18 and 22 °C). Several pre-adult life history traits (development time, survival and competitive ability), adult life history related traits (wing size, wing shape and wing-aspect ratio), and wing size and shape asymmetries were measured at the three temperatures. Cold-adapted (13 °C) populations evolved longer development times and showed lower survival at the highest developmental temperature. No divergence for wing size was detected following adaptation to temperature extremes (13 and 22 °C), in agreement with earlier observations, but wing shape changes were obvious as a result of both thermal adaptation and development at different temperatures. However, the evolutionary trends observed for the wing-aspect ratio were inconsistent with an adaptive hypothesis. There was some indication that wing shape asymmetry has evolutionarily increased in warm-adapted populations, which suggests that there is additive genetic variation for fluctuating asymmetry and that it can evolve under rapid environmental changes caused by thermal stress. Overall, our results cast strong doubts on the hypothesis that body size itself is the target of selection, and suggest that pre-adult life history traits are more closely related to thermal adaptation.
Spatial patterns and environmental factors affecting the presence of Melampsorella caryophyllacearum infections in an Abies alba forest in NE Spain
Authors: Solla A. , Camarero J. J. 
Published: May 2006

SummaryThe presence of trunk swellings caused by the rust fungus Melampsorella caryophyllacearum was systematically surveyed in an Abies alba forest (Irati, NE Spain), using 1237 circular plots (diameter = 18 m). The relationship between fungal presence and several abiotic (aspect, elevation, distance to the nearest river and slope) and biotic factors (basal area of A. alba and/or Fagus sylvatica, shrub, fern and herb cover) was assessed through correlation and ordination analyses. Additionally, the spatial pattern of the presence of diseased trees was described using Ripley's K function. Southern‐aspect plots had a significantly lower presence of diseased trees than plots‐oriented north, east and west. Plots with diseased trees were located at a significantly lower elevation, and at a shorter distance to the river than plots without infections. Plots with diseased trees had almost twice the average A. alba basal area, and less average F. sylvatica basal area than plots without diseased trees. However, similar mean values of slope and shrub, fern and herb cover were found in both types of plots. The disease showed spatial aggregation in patches with a mean radius of ca. 900 m. The implications of the results for disease management are discussed.
Defence reactions of developing somatic embryos of Algerian fir (Abies numidica)
Authors: Vooková B. , Hřib J. , Kormu?ák A. , Adamec V. 
Published: May 2006

SummaryDefence reactions of embryonal suspensor mass (ESM), precotyledonary, cotyledonary and desiccated cotyledonary somatic embryos of Abies numidica were tested by dual cultures with Phaeolus schweinitzii. Defence reactions were expressed at a very early stage of somatic embryo development. Both ESM and early somatic embryos inhibited mycelial growth, but the strongest defence was shown by the precotyledonary somatic embryos. The cotyledonary and desiccated cotyledonary embryos also showed defence reactions but with less intensity. Eight major components of soluble proteins, already present in the ESM, increased in concentration during subsequent developmental stages. Synthesis of two low‐molecular components of 6 and 3 kDa appeared in desiccated embryos. Probable regulation of defence reactions by auxins in early somatic embryos, as well as by abscisic acid content and storage proteins in subsequent developmental stages, is discussed.
Calcium‐excess causes subclinical changes of bone growth in Beagles but not in Foxhound‐crossbred dogs, as measured in X‐rays
Authors: Dobenecker B. , Kasbeitzer N. , Flinspach S. , Köstlin R. , Matis U. , Kienzle E. 
Published: May 2006

SummaryNumerous investigations and reports have covered the potential negative effects of an excess of calcium (Ca) in the skeletal development of young dogs. However, it still remains unclear why not all puppies, particularly of larger breeds, develop clinical signs of skeletal disorders after an overexposure to Ca. This trial with the small Beagle breed and a larger Foxhound‐crossbred dog (with an adult weight of around 35 kg) investigated the effects of Ca‐excess on parameters of bone growth. The employed small breed is known for its chondrodystrophic predispositions, no such data are reported for the slender hound‐type Foxhound‐crossbred dogs. The Ca‐supply had no influence on weight development and general health of the dogs. The measurements of bone lengths and widths in X‐rays of the forearm of Beagles and Foxhound‐crossbred dogs at 6 weeks of age, and again after a period of overexposure to Ca at about 27 weeks of age, revealed a growth‐reducing influence only in Beagles, without influence on clinical parameters of skeletal health.
Subacute effects of moderate feed loads of isolated Fusarium toxin deoxynivalenol on selected parameters of metabolism in weaned growing piglets
Authors: Drochner W. , Schollenberger M. , Götz S. , Lauber U. , Tafaj M. , Piepho H.‐P. 
Published: May 2006

SummaryIn 36 female weaned piglets, the effect of different dosages (0, 300, 600 and 1200 μg/kg feed) of isolated, pure Fusarium toxin deoxynivalenol (DON) was examined during a period of 8 weeks. Standardised trial conditions were provided. Pigs were fed restrictively to allow a complete feed intake of all animals. Parameters of liver integrity, haematological data and blood concentrations of some selected metabolic components of energy and protein metabolism were examined weekly. Enzyme aspartate aminotransferase was affected subclinically by age and significantly by dosage, which was proved by Wald F‐test. Some additional enzymes, for instance alanine aminotransferase, gamma glutamyl transferase, glutamate dehydrogenase and sorbit dehydrogenase, showed no clear systematic effect. Urea and glucose in the blood were inter‐related. Depending on DON load with increasing glucose concentrations, the urea level declined. Albumin and total protein in serum showed no significant DON‐related effect. Haemoglobin in blood was found to be significantly affected by DON, which was proved by the Wald F‐test, where the effect was more pronounced with 600 μg DON/kg diet compared to 1 200 μg DON/kg. An obvious DON‐related affection of liver, N‐metabolism and stimulation of haematopoiesis depending on dosage and time is discussed.
The influence of dietary conjugated linoleic acid on blood serum and colostrum immunoglobulin G concentration in female goats before and after parturition
Authors: Castro N. , Capote J. , Martín D. , Argüello A. 
Published: May 2006

SummaryThe effects on blood serum and colostrum immunoglobulin G (IgG) levels from including conjugated linoleic acid (CLA) in the diet were evaluated in goats. In experiment 1, 20 goats were allotted into two groups; the CLA group received 20 g/kg of dry matter of CLA 60 and the control group received 0 g/kg of CLA 60, from the third month of gestation until partum. Blood samples were taken every 2 weeks from 1 day before CLA inclusion to partum. From partum until 96 hours, blood and colostrum samples were taken every 24 h. Before partum, IgG serum blood levels were 15.6 and 9.4 mg/ml (CLA and control, respectively); the time effect was statistically significant. After partum (96 h), the effect of CLA dietary inclusion was statistically significant.
The ethic of care development: A longitudinal study of moral reasoning among practical‐nursing, social‐work and law‐enforcement students
Authors: JUUJÄRVI SOILE 
Published: May 2006

The study investigated changes in care‐based moral reasoning, in the context of justice development over the 2‐year period among practical‐nursing, bachelor‐degree social‐work and law‐enforcement students (N = 59). Main measures were Skoe's Ethic of Care Interview and Colby et al.'s Moral Judgment Interview. Of the participants 34% progressed in care reasoning, and 48% in justice reasoning. Social‐work and nursing students progressed in care reasoning, and all groups progressed in justice reasoning. One participant (1.7%) regressed in care reasoning. Care and justice reasoning were parallel in terms of internal consistency, and they were positively related to each other. Findings suggest that care reasoning follows a developmental sequence, involving three main and two transitional levels, as suggested by Gilligan (1982). Main levels include self‐concern (Level 1), caring for others (Level 2), and balanced caring for self and others (Level 3).
The French Riots: Questioning Spaces of Surveillance and Sovereignty
Authors: Ossman Susan , Terrio Susan 
Published: May 2006

ABSTRACTThis paper examines the riots in France in late 2005 in terms of how they lead to a reconceptualization of the spaces of danger, culture, territory, and sovereignty. It traces a brief history of danger zones and immigration, noting how these two terms have increasingly overlapped. We analyse key discursive formations ‐ legal, political, social scientific, and media ‐ whose explanation for the emergence of the “immigrant” delinquent is linked to what is identified as a culture of poverty. They provide a sustained examination of recent legal reforms of juvenile law as well as judicial practices within the juvenile justice system to show the systematic exclusionary practices of what is claimed to be a colour blind republican system. They reveal a consensus across the political spectrum and among police, prosecutors, investigating magistrates, and new security experts on the need to privilege accountability, restitution, and retribution in the treatment of juvenile offenders. We present evidence from interviews and ethnographic observation among youths of all backgrounds. Ironically, while the children of immigrants seek to claim a voice in the national community, their peers from more privileged social milieu express increasing distance from national concerns, seeking to lead lives as Europeans or global citizens. We end by arguing that this needs to be taken into account in any analysis of frustrated and disenfranchised suburban youths. A transnational or supra‐national sociology that accounts for the itineraries of immigrants of all kinds must be developed.
The October Riots in France: A Failed Immigration Policy or the Empire Strikes Back?
Authors: Haddad Yvonne Yazbeck , Balz Michael J. 
Published: May 2006

ABSTRACTIn October 2005, the predominately Arab‐immigrant suburbs of Paris, Lyon, Lille and other French cities erupted in riots by socially alienated teenagers, many of them second‐ or third‐generation immigrants. For many French observers, it was a painful reminder that France's immigration policy had, quite bluntly, failed. The grand French ideal of égalité, the equality of all citizens of the Republic, itself a by‐product of France's colonial past, demonstrated its incompatibility with twenty‐first century reality.The French immigration experience is markedly different than those of other European countries, as France's is tainted by colonial history, republican idealism, a rigidly centralized government structure, and deep‐seeded traditions of xenophobia. Indeed, the nineteenth century French policy of the mission civilicatrice (civilizing mission) still influences French policy toward its immigrants today: rather than accept cultural differences, the French government demands that all its citizens adhere to a rigid and exclusive “French” identity.As such, the children of the generation of immigrants that the French government actively brought to France to fuel its post‐war expansion now find themselves unemployed and socially marginalized. Government social structures meant to ease the disparity between social classes, such as public housing and education, generally do more to aggravate problems than to solve them; public housing is woefully inadequate and the education structure institutionalizes the poor quality of schools in immigrant communities. Despite this generally poor outlook, the French have recently made some progress toward better integration of their immigrant communities, though these efforts are generally met with wide‐spread demagogic and populist opposition.
Retirement Return Migration from Sweden
Authors: Klinthäll Martin 
Published: May 2006

ABSTRACTThis study deals with return migration among immigrants in Sweden who are between 51 and 80 years old. An important question regards the impact of retirement on return migration. Some circumstances connected to the withdrawal from the labour market suggest an increased propensity to return, such as the transition from a wage income to a pension, which weakens the link between place of residence and income. In addition, patterns of return migration at the end of working life may indicate whether or not temporary migration is a planned strategy. It is found that when reaching the age of 65, the legal retirement age in Sweden, the probability of return migration increases, in particular for men. The effect of retirement is immediate; the probability of return migration declines again beyond the age of 65, indicating a conscious plan to return to the home country when the labour market career is over.Furthermore, immigrants who receive early retirement compensation have a considerably higher probability of return migration compared to those who are not retired. These clear “retirement effects” show that return migration can be an important ingredient in the welfare optimization strategies of migrants. When it comes to income selectivity, the analysis shows that there is a positive selection, something that is expected when migrants are target savers with a temporary migration strategy.
Effects of variability in prey abundance on reproduction and foraging in chinstrap penguins (Pygoscelis antarctica)
Authors: Croll D. A. , Demer D. A. , Hewitt R. P. , Jansen J. K. , Goebel M. E. , Tershy B. R. 
Published: May 2006

AbstractLife‐history theory predicts that adults of long‐lived species such as seabirds should optimally balance investment in current and future offspring. However, when trying to optimize investment in offspring provisioning, the most energetically costly component of seabird parental care, adults need to contend with large interannual fluctuations in prey availability and hence the cost of chick provisioning. Adults faced with this uncertainty can mechanistically balance parental care by adopting a strategy somewhere along the continuum between maintaining constant investment in foraging effort between years and letting chick provisioning fluctuate or holding chick provisioning constant and varying investment in foraging effort. Using ship‐based hydroacoustic assessment of prey, time‐depth recorders attached to penguins and land‐based observations at the breeding colony, we examined how foraging and reproductive effort in breeding chinstrap penguins Pygoscelis antarctica responded to interannual variation in the abundance of Antarctic krill Euphausia superba in the vicinity of Seal Island, South Shetland Islands, 1990–1992. Regional measures of krill density varied by a factor of 2.5 (47.0, 23.8 and 61.2 g m−2 in 1990, 1991 and 1992, respectively) and was correlated with annual measures of breeding adult body weight and reproductive performance (breeding population size, duration of chick rearing, chick growth, breeding success and fledgling weight). In contrast, measures of penguin foraging effort (dive depth, dive duration, number of trips day−1, trip duration, number of dives trip−1 and dive rate) did not differ between years. We conclude that chinstrap penguins reduce reproductive success rather than increase foraging effort in response to decreases in prey abundance in a manner consistent with predictions of life‐history strategies for long‐lived seabirds.
Cozumel Island fox (Urocyon sp.) dwarfism and possible divergence history based on subfossil bones
Authors: Gompper M. E. , Petrites A. E. , Lyman R. L. 
Published: May 2006

AbstractArcheological evidence indicates that a dwarf fox (Urocyon sp.) has inhabited Cozumel Island, Mexico at least since the arrival of Mayan peoples, but no taxonomic descriptions or morphological assessments of the animal exist. A recent field study indicates that this fox is on the verge of extinction and therefore it is critical to describe the population. Because no skins or complete skulls of the Cozumel fox exist in museum collections, we examined subfossils collected during archeological excavations of the human‐waste middens of Mayans who inhabited the island c. 1500–500 years before present. Measurements of 37 bones from a minimum of 12 adult individuals suggest that this animal is diminutive (the body size was c. 60–80% of mainland specimens), similar to other Carnivora from Cozumel that are recognized as distinct species. Estimated rates of character differentiation for mainland and island foxes under a range of possible divergence periods (1000–130 000 years) suggest that the Cozumel fox population has been isolated for a minimum of 5000–13 000 years, and perhaps far longer. Colonization of the island by Urocyon therefore likely predates the colonization of Cozumel by humans.
Embryonic stem cell‐derived neuron models of Parkinson's disease exhibit delayed neuronal death
Authors: Yamashita Hiroshi , Nakamura Takeshi , Takahashi Tetsuya , Nagano Yoshito , Hiji Masanori , Hirabayashi Takahiro , Amano Taku , Yagi Takeshi , Sakai Norio , Kohriyama Tatsuo , Matsumoto Masayasu 
Published: May 2006

AbstractEstablishment of a Parkinson's disease (PD) neuron model was attempted with mouse embryonic stem (ES) cells. ES cell lines over‐expressing mouse nuclear receptor‐related 1 (Nurr1), together with human wild‐type and alanine 30 → proline (A30P) and alanine 53 → threonine (A53T) mutant α‐synuclein were established and subjected to differentiation into dopaminergic neurons. The ES cell‐derived dopaminergic neurons expressing wild‐type or mutant α‐synuclein exhibited the fundamental characteristics consistent with dopaminergic neurons in the substantia nigra. The ES cell‐derived PD model neurons exhibited increased susceptibility to oxidative stress, proteasome inhibition, and mitochondrial inhibition. Cell viability of PD model neurons and the control neurons was similar until 28 days after differentiation. Nonetheless, after that time, PD model neurons gradually began to undergo neuronal death over the course of 1 month, showing cytoplasmic aggregate formation and an increase of insoluble α‐synuclein protein. Such delayed neuronal death was observed in a mutant α‐synuclein protein level‐dependent manner, which was slightly inhibited by a c‐jun N‐terminal kinase inhibitor and a caspase inhibitor. Such cell death was not observed when the same ES cell lines were differentiated into oligodendrocytes. The ES cell‐derived PD model neurons are considered as prospective candidates for a new prototype modelling PD that would allow better investigation of the underlying neurodegenerative pathophysiology.