bluuebunny/crossref_metadata_2025_split huggingface dataset:
Marking the Fifth Anniversary of the Landing on Titan: Huygens Fifth Anniversary Meeting; Barcelona, Spain, 13–15 January 2010
Authors: Coustenis Athena , Lebreton Jean‐Pierre , Matson Dennis 
Published: June 2010

On the occasion of the fifth anniversary of the European Space Agency's Huygens probe landing on Saturn's moon Titan (14 January 2005), approximately a hundred international scientists and engineers met at the CosmoCaixa Science Museum, in Spain, to assess what was discovered and what remains to be done by future spacecraft missions to Titan and the Saturnian system. The Huygens probe was deployed from NASA's Cassini spacecraft.Speakers at the meeting pointed out that discoveries from the Cassini‐Huygens mission have shown that Titan is much more interesting than even their wildest expectations more than 20 years ago when the mission was conceived, in the 1980s, several years after the Voyager flybys. Perhaps most stunning are the many similarities between Titan and the Earth. Though there are important differences, when one views the lakes and seas, the fluvial terrain, the sand dunes, and other features through the hazy, nitrogen atmosphere, it calls to mind the geological processes that created analogous features on the Earth. On Titan it has been discovered that frozen water plays the geological role of rock, and liquid methane takes the role of terrestrial water. As Saturn proceeds along its orbit about the Sun, the seasons change on Titan. The seasonal effects on the transport of methane are starting to be seen. A large lake in the south polar region seems to be getting smaller as winter sets in.
High bicarbonate assimilation in the dark by Arctic bacteria
Authors: Alonso-Sáez Laura , Galand Pierre E , Casamayor Emilio O , Pedrós-Alió Carlos , Bertilsson Stefan 
Published: June 2010

Abstract
Although both autotrophic and heterotrophic microorganisms incorporate CO2 in the dark through different metabolic pathways, this process has usually been disregarded in oxic marine environments. We studied the significance and mediators of dark bicarbonate assimilation in dilution cultures inoculated with winter Arctic seawater. At stationary phase, bicarbonate incorporation rates were high (0.5–2.5 μg C L−1 d−1) and correlated with rates of bacterial heterotrophic production, suggesting that most of the incorporation was due to heterotrophs. Accordingly, very few typically chemoautotrophic bacteria were detected by 16S rRNA gene cloning. The genetic analysis of the biotin carboxylase gene accC putatively involved in archaeal CO2 fixation did not yield any archaeal sequence, but amplified a variety of bacterial carboxylases involved in fatty acids biosynthesis, anaplerotic pathways and leucine catabolism. Gammaproteobacteria dominated the seawater cultures (40–70% of cell counts), followed by Betaproteobacteria and Flavobacteria as shown by catalyzed reporter deposition fluorescence in situ hybridization (CARDFISH). Both Beta- and Gammaproteobacteria were active in leucine and bicarbonate uptake, while Flavobacteria did not take up bicarbonate, as measured by microautoradiography combined with CARDFISH. Within Gammaproteobacteria, Pseudoalteromonas-Colwellia and Oleispira were very active in bicarbonate uptake (ca. 30 and 70% of active cells, respectively), while the group Arctic96B-16 did not take up bicarbonate. Our results suggest that, potentially, the incorporation of CO2 can be relevant for the metabolism of specific Arctic heterotrophic phylotypes, promoting the maintenance of their cell activity and/or longer survival under resource depleted conditions.
Active methylotrophs in the sediments of Lonar Lake, a saline and alkaline ecosystem formed by meteor impact
Authors: Antony Chakkiath Paul , Kumaresan Deepak , Ferrando Lucia , Boden Rich , Moussard Hélène , Scavino Ana Fernández , Shouche Yogesh S , Murrell J Colin 
Published: June 2010

Abstract
Lonar Lake is a unique saline and alkaline ecosystem formed by meteor impact in the Deccan basalts in India around 52 000 years ago. To investigate the role of methylotrophy in the cycling of carbon in this unusual environment, stable-isotope probing (SIP) was carried out using the one-carbon compounds methane, methanol and methylamine. Denaturing gradient gel electrophoresis fingerprinting analyses performed with heavy 13C-labelled DNA retrieved from sediment microcosms confirmed the enrichment and labelling of active methylotrophic communities. Clone libraries were constructed using PCR primers targeting 16S rRNA genes and functional genes. Methylomicrobium, Methylophaga and Bacillus spp. were identified as the predominant active methylotrophs in methane, methanol and methylamine SIP microcosms, respectively. Absence of mauA gene amplification in the methylamine SIP heavy fraction also indicated that methylamine metabolism in Lonar Lake sediments may not be mediated by the methylamine dehydrogenase enzyme pathway. Many gene sequences retrieved in this study were not affiliated with extant methanotrophs or methylotrophs. These sequences may represent hitherto uncharacterized novel methylotrophs or heterotrophic organisms that may have been cross-feeding on methylotrophic metabolites or biomass. This study represents an essential first step towards understanding the relevance of methylotrophy in the soda lake sediments of an unusual impact crater structure.
Annual and circadian activity patterns of badgers (Meles meles) in Białowieża Primeval Forest (eastern Poland) compared with other Palaearctic populations
Authors: Kowalczyk Rafał , Jȩdrzejewska Bogumiła , Zalewski Andrzej 
Published: June 2010

AbstractAim  The annual and circadian rhythms and duration of activity of Eurasian badger Meles meles (Linnaeus 1758) were studied in a low‐density population inhabiting the primeval woodland in the European temperate zone. Results were compared with available data from the literature on seasonal changes in body mass and winter inactivity of badgers from across the Palaearctic region.Location  Field work was carried out in Białowieża Primeval Forest, eastern Poland. Biogeographical variation was reviewed based on twenty‐three localities in the Palaearctic region (from Western Europe to Central Siberia).Methods  Thirteen badgers were radio‐collared in 1997–2001. Their circadian activity was sampled by 24‐h sessions of continuous radio‐tracking with location taken at 15‐min intervals. Annual activity was studied by radio‐tracking and inspections of setts. Earthworm (badgers’ main food) biomass was estimated in four types of habitats throughout the year.Results  Badgers were nocturnal with one long bout of activity. Their rhythms of diel activity differed between spring and autumn, and between adult and subadult individuals. On average, badgers emerged from setts at 19:00 hours and returned to them at 03:42 hours. The highest level of activity was recorded between 20:00 and 03:00 hours. Duration of daily activity was, on average, 8.2 h day−1, but varied significantly between seasons. The seasonal changes were inversely related to the abundance of earthworms. Duration of activity also depended on daily temperature, especially in the cold season. In winter, badgers stayed inactive for an average of 96 days per year. In autumn, they built fat reserves and their body mass nearly doubled compared with the spring values.The literature review on annual cycle of activity and body mass changes in Eurasian badgers showed that fat storage and duration of winter sleep strongly depended on climate (best approximated by January mean temperature). In regions with warm climates, badgers were active year round and their body mass changed only slightly, while in regions with severe winters badgers increased their body mass twofold from spring to autumn, and stayed inactive for as long as 6 months per year.Main conclusion  We propose that, in the temperate and boreal zones of the Palaearctic region, the ultimate determinant of biogeographical variation in badgers’ annual activity is the winter shortage of earthworms, which are the main component of badger diet.
On the validity of Bergmann's rule
Authors: Meiri Shai , Dayan Tamar 
Published: June 2010

AbstractAimWe reviewed the occurrence of Bergmann's rule in birds (ninety‐four species) and mammals (149 species), using only studies where statistical significance of the results was tested. We also tested whether studies using different characters as surrogates of body size have a different tendency to conform to Bergmann's rule, whether body size and nest type (in birds) have an influence on the tendency to conform to the rule, and whether sedentary birds conform to the rule more than migratory birds.LocationWorldwide.MethodsWe reviewed published data on geographic and temporal variation in body size, using only studies where the statistical significance of the results was tested. We asked how many species conform to the rule out of all species studied in each order and family.ResultsOver 72% of the birds and 65% of the mammal species follow Bergmann's rule. An overall tendency to follow the rule occurs also within orders and families. Studies using body mass in mammals show the greatest tendency to adhere to Bergmann's rule (linear measurements and dental measurements show a weaker tendency); while in birds, studies using body mass and other surrogates (linear measurements and egg size) show a similar tendency. Birds of different body mass categories exhibit a similar tendency to follow Bergmann's rule, while in mammals the lower body size categories (4–50 and 50–500 g) show a significantly lower tendency to conform to the rule. Sedentary birds tend to conform to Bergmann's rule more than migratory species. Nest type does not affect the tendency to conform to Bergmann's rule.Main conclusions Bergmann's rule is a valid ecological generalization for birds and mammals.
Large‐scale geographical trends in fruit traits of vertebrate‐dispersed temperate plants
Authors: Hampe Arndt 
Published: June 2010

AbstractAim  To assess large‐scale geographical trends in the character of fleshy, vertebrate‐dispersed fruits.Location  Europe between central Sweden and southern Spain.Methods  Analyses of fruit of sixty‐three plant species from twenty‐nine families were compiled from four regional data sets. Four structural and five chemical fruit traits were analysed intraspecifically to control rigorously for phylogenetic lineage effects. Trends were examined in relation to various biological features of the considered species.Results  Contents of soluble carbohydrate and lipids decreased markedly northwards. Fruit diameter and fresh mass peaked at the wettest site, while the pulp water content remained more constant throughout the gradient than any other fruit trait. Ash content, seed number and seed mass did not change, while the nitrogen content showed conflicting trends. No relation was detected between observed variation in fruit traits and fruit type, fruit colour, ripening season, plant growth form, leaf longevity, or geographical distribution of the considered plant species.Main conclusions  Considerable intraspecific variability exists in vertebrate‐dispersed fruits on large geographical scales. Climate presumably affects particularly those traits related to carbon and water gain and storage. Most research on fruit–frugivore interactions has been carried out on small spatial scales and failed to find matchings between frugivore communities and the character of fleshy fruits. I suggest that explicitly addressed large‐scale surveys on the geographical variability of fruits and their disperser assemblages are needed to elucidate their spatial patterns and to determine the extent to which fleshy fruit traits are shaped by animals and/or abiotic factors.
Modelling habitat‐suitability using museum collections: an example with three sympatric Apodemus species from the Alps
Authors: Reutter Brigitte A. , Helfer V. , Hirzel A. H. , Vogel P. 
Published: June 2010

AbstractAim, Location Although the alpine mouse Apodemus alpicola has been given species status since 1989, no distribution map has ever been constructed for this endemic alpine rodent in Switzerland. Based on redetermined museum material and using the Ecological‐Niche Factor Analysis (ENFA), habitat‐suitability maps were computed for A. alpicola, and also for the co‐occurring A. flavicollis and A. sylvaticus.Methods In the particular case of habitat suitability models, classical approaches (GLMs, GAMs, discriminant analysis, etc.) generally require presence and absence data. The presence records provided by museums can clearly give useful information about species distribution and ecology and have already been used for knowledge‐based mapping. In this paper, we apply the ENFA which requires only presence data, to build a habitat‐suitability map of three species of Apodemus on the basis of museum skull collections.Results Interspecific niche comparisons showed that A. alpicola is very specialized concerning habitat selection, meaning that its habitat differs unequivocally from the average conditions in Switzerland, while both A. flavicollis and A. sylvaticus could be considered as ‘generalists’ in the study area.Main conclusions Although an adequate sampling design is the best way to collect ecological data for predictive modelling, this is a time and money consuming process and there are cases where time is simply not available, as for instance with endangered species conservation. On the other hand, museums, herbariums and other similar institutions are treasuring huge presence data sets. By applying the ENFA to such data it is possible to rapidly construct a habitat suitability model. The ENFA method not only provides two key measurements regarding the niche of a species (i.e. marginality and specialization), but also has ecological meaning, and allows the scientist to compare directly the niches of different species.
SOCIAL NETWORKS IN SLOVENIA
Authors: Hlebec Valentina , Filipovič Hrast Maša , Kogovšek Tina 
Published: June 2010

ABSTRACT
The process generally referred to as ‘the transition’ implied a complex set of social changes in Central and Eastern European countries (CEE). On the one hand, there were institutional reforms which were launched to abolish the socialist economic and political systems. On the other hand, the provision of welfare was also affected by ‘transition’. The change could be observed at the institutional level (i.e., through the welfare state) as well as at the social and individual level – in the ways individuals associated, how they perceived new risks and with whom they engaged to confront them. In this article we focus on social support provision from informal sources, i.e., ego-centered social support networks, which are an important foundation for the quality of everyday life. We would like to find out whether changes in the socio-economic system are reflected in and accompanied by changes in social support providers. How have people responded to transition? Did the patterns of support and social support providers change in this period? Consequently, the research question addressed in this article is the following: do the current types of social networks differ from those in the 1980s? We try to answer it by analyzing and comparing the data on social support networks in 1987 and 2002. The data are interpreted in the context of the transition that was happening in Slovenia at the time.
A Poisson model for random multigraphs
Authors: Ranola John M. O. , Ahn Sangtae , Sehl Mary , Smith Desmond J. , Lange Kenneth 
Published: June 2010

AbstractMotivation: Biological networks are often modeled by random graphs. A better modeling vehicle is a multigraph where each pair of nodes is connected by a Poisson number of edges. In the current model, the mean number of edges equals the product of two propensities, one for each node. In this context it is possible to construct a simple and effective algorithm for rapid maximum likelihood estimation of all propensities. Given estimated propensities, it is then possible to test statistically for functionally connected nodes that show an excess of observed edges over expected edges. The model extends readily to directed multigraphs. Here, propensities are replaced by outgoing and incoming propensities.Results: The theory is applied to real data on neuronal connections, interacting genes in radiation hybrids, interacting proteins in a literature curated database, and letter and word pairs in seven Shaskespearean plays.Availability: All data used are fully available online from their respective sites. Source code and software is available from http://code.google.com/p/poisson-multigraph/Contact: klange@ucla.eduSupplementary information: Supplementary data are available at Bioinformatics online.
Homology of SMP domains to the TULIP superfamily of lipid-binding proteins provides a structural basis for lipid exchange between ER and mitochondria
Authors: Kopec Klaus O. , Alva Vikram , Lupas Andrei N. 
Published: June 2010

Abstract
Mitochondria must uptake some phospholipids from the endoplasmic reticulum (ER) for the biogenesis of their membranes. They convert one of these lipids, phosphatidylserine, to phosphatidylethanolamine, which can be re-exported via the ER to all other cellular membranes. The mechanisms underlying these exchanges between ER and mitochondria are poorly understood. Recently, a complex termed ER–mitochondria encounter structure (ERMES) was shown to be necessary for phospholipid exchange in budding yeast. However, it is unclear whether this complex is merely an inter-organelle tether or also the transporter. ERMES consists of four proteins: Mdm10, Mdm34 (Mmm2), Mdm12 and Mmm1, three of which contain the uncharacterized SMP domain common to a number of eukaryotic membrane-associated proteins. Here, we show that the SMP domain belongs to the TULIP superfamily of lipid/hydrophobic ligand-binding domains comprising members of known structure. This relationship suggests that the SMP domains of the ERMES complex mediate lipid exchange between ER and mitochondria.
Contact: andrei.lupas@tuebingen.mpg.de
Supplementary information: Supplementary data are available at Bioinformatics online.
A Gibbs-potential-based formulation for obtaining the response functions for a class of viscoelastic materials
Authors: Rajagopal K. R. , Srinivasa A. R. 
Published: June 2010

In this article, we demonstrate the use of a Gibbs-potential-based formulation as a means for developing a thermodynamically consistent model for a class of viscoelastic fluids of the rate type. Since one cannot always use a formulation based on a Helmholtz potential to model rate-type models, the formulation takes on added significance. The salient features of this approach are the following:
— this approach provides a thermodynamical rationalization of many commonly used models that are developed on purely phenomenological grounds; furthermore, the study provides a framework for generating other classes of models and allows for a relatively straightforward means for the inclusion of thermal effects,
— the approach provides a simple means for including anisotropic effects without the need for directors or other new internal variables, and
— the approach does not use any additional variables (such as conformation tensors or elastic strains measured from stress free configurations) other than the current (or Cauchy) stress, the current mass density and the velocity gradient.
We also show how the entire structure of the theory is obtained from just two scalar functions, the Gibbs potential and the rate of dissipation function.
Mellowing with age: older parents are less responsive to a stressor in a long‐lived seabird
Authors: Heidinger Britt J. , Chastel Olivier , Nisbet Ian C. T. , Ketterson Ellen D. 
Published: June 2010

Summary 1. Reproductive success often increases with age; however the mechanisms underlying this commonly observed pattern are poorly understood. One mechanism that may be important is a set of physiological responses (the stress response) that allows organisms to evade and cope with stressors, but often inhibits reproduction. 2. If older parents respond less strongly to stressors than younger parents, this age‐related difference in the stress response may contribute to the higher reproductive success that often characterizes older parents. 3. Typically the stress response is measured as an increase in plasma glucocorticoid (CORT) concentration, and we have previously reported that stress‐induced CORT levels decline with age in the common tern (Sterna hirundo). Another hormone, prolactin (PRL), has been reported to decrease in response to stressors in breeding birds and is often positively associated with parental behaviour. We predicted that like the CORT stress response, the PRL stress response would also be suppressed with age. 4. To test this prediction, we captured known‐age, incubating common terns ranging in age from 3 to 29 years and measured stress‐induced changes in PRL and CORT levels within the same individuals. 5. We found that PRL levels decreased less rapidly in response to capture and restraint stress in older than in younger parents. In these same birds, we also found that stress‐induced maximum CORT levels decreased with age, which is consistent with what we have previously reported for this species. Measures of PRL and CORT were not, however, correlated within individuals. 6. Taken together, these results support the hypothesis that modulations of both the PRL and CORT stress response are flexible hormonal mechanisms that help to account for the increase in reproductive success that occurs with age.
Effects of agricultural intensification on plant diversity in Mediterranean dryland cereal fields
Authors: José‐María Laura , Armengot Laura , Blanco‐Moreno José M. , Bassa Montserrat , Sans F. Xavier 
Published: June 2010

Summary 1. Agricultural intensification, at field and landscape scales, has caused a decrease in weed richness and changes in species composition. In order to prevent this loss of diversity and develop efficient management regimes, it is important to understand how both aspects of intensification affect plant diversity and the way in which they interact. 2. This study assessed plant diversity at the centre, edges and boundaries of 29 organic and 29 conventional cereal fields distributed in 15 agrarian localities of the NE Iberian Peninsula. We focused on the composition of plant assemblages and on the specific richness at the field level, which was calculated for the whole set of species and for that of characteristic arable weeds. The percentage of arable land together with human settlements was used as a surrogate for landscape complexity and the amount of nitrogen inputs for land‐use intensity. 3. Our results show that both scales of agricultural intensification have a similar negative effect on the total plant species and characteristic arable weed richness, and they also affect plant assemblages. Furthermore, we found no strong interaction between landscape and land‐use intensity for explaining total plant richness. 4. The relative importance of farming intensity and landscape varies depending on the location within the field, which can be attributed to differences in the agricultural impact and limited seed dispersal from adjacent habitats. Management is the main factor in explaining differences among field centres, whereas changes at boundaries are mainly due to landscape characteristics, and at edges both factors are relevant. 5. Synthesis and applications. To preserve agricultural plant diversity it is equally important to prevent agricultural intensification at field and landscape scales. Policies enhancing low‐intensity management techniques, such as organic farming, are the main way to promote diversity inside the fields and will be equally beneficial in simple and complex landscapes for total plant species richness. To maintain diversity within agricultural areas, it is also important to reduce farming intensity at the edges, which would favour characteristic arable weeds and margins’ overall plant diversity.