bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hayfields enhance colony size of the Barn SwallowHirundo rusticain northern Italy
Authors: SICURELLA BEATRICE , CAPRIOLI MANUELA , ROMANO ANDREA , ROMANO MARIA , RUBOLINI DIEGO , SAINO NICOLA , AMBROSINI ROBERTO 
Published: June 2013

SummaryThe widespread decline of farmland birds is a major issue of biological conservation in European countries. The Barn SwallowHirundo rusticais a flagship species for farmland bird conservation owing to its aesthetic and cultural value and to the sharp decline observed in several populations. Based on a long-term monitoring project of a population in a protected area of Northern Italy, we documented a dramatic decline of 56.6% between 1999 and 2011, corresponding to a decrease of 6.59% each year. We also showed that colonies were on average larger in farms with livestock than those without livestock, and that colony size increased with increasing extent of hayfields within 200 m from the colony in farms without livestock, but not in those with livestock. Hayfield extent at greater distances did not influence population size or trend. Cessation of livestock farming therefore determined a decline in local colonies, but this decline may be buffered by an increase in hayfield extent within 200 m from the farm. However, variation in the ecological features of breeding sites explained only a fraction of the observed population decline, suggesting that ecological conditions during migration and wintering may be crucial in affecting population trends. Mean hatching date of first broods advanced in recent years, but less so in farms with, than without, livestock. Independently of year, mean hatching date advanced more in farms with greater extent of hayfields within 200 m of the colony. Reproductive success, measured as the mean number of fledged offspring per nest, declined significantly with hatching date, but was not affected by hayfield extent. Conversely, nestling quality, in terms of body mass and feather development, improved with increasing extent of hayfields around the colony, particularly in late-hatched first clutches. Our findings suggest that conservation strategies for this declining species should include both the maintenance of livestock farming and the enlargement of hayfields close to breeding colonies, particularly in farms where livestock farming has ceased.
Longevity insurance markets and Money's worth ratios in Korea
Authors: LEE KYONGHEE 
Published: June 2013

AbstractThe rare annuitization, thin immediate annuity market, and date limitation have prevented the attempts to analyze the longevity insurance market in Korea. The purpose of this paper is to examine the relative value of Korean annuity rates to theoretical ones and to provide a new evidence on the function of the voluntary annuity market in terms of the money's worth ratio (MWR). Our results show that the immediate annuity market in Korea is reasonably efficient. For example, the money's worth ratio of an immediate annuity of a 10-year guarantee period for a 65-year-old male is estimated to be about 0.8 with the general population mortality rate, while it improves to 0.9 with the annuitant mortality table. Average MWR is similar to that of other countries with thin annuity market, which show that annuitants in Korea pay a comparable cost to that in other countries.
The effect of differing intensities of acute cycling on preadolescent academic achievement
Authors: Duncan Michael , Johnson Andrew 
Published: June 2013

AbstractThe present study examined the effects of differing intensity levels of acute exercise on preadolescent academic ability. In a repeated measures design, 18 preadolescent participants (mean age±S.D.=9.8±1.4 years: 9 male and 9 female) completed the Wide Range Achievement Test (WRAT 4) following 20 minutes of rest, 20‐minutes on a cycling ergometer at 50% maximal heart rate reserve (HRR), and 20‐minutes on a cycling ergometer at 75% HRR on separate days. Exercise was found to improve spelling irrespective of intensity level. Moderate levels of exercise improved reading although the effect of high levels of intensity is less clear. Both intensity levels impaired arithmetic, whilst sentence comprehension was unaffected. These findings further support the past research that indicates acute bouts of exercise can selectively improve cognition in preadolescent children. However, the present study finds no support for the notion that increasing the intensity of exercise accentuates benefits.
Effects of maternal age and mass on foraging behaviour and foraging success in the northern elephant seal
Authors: Hassrick Jason L. , Crocker Daniel E. , Costa Daniel P. 
Published: June 2013

SummaryAnimals that show indeterminate growth and put relatively constant proportions of stored body reserves towards annual reproductive effort are confronted with a problem of meeting ever‐increasing energetic demands in unpredictable environments.We examined how intrinsic traits, mass and age, as well as extrinsic environmental features impact diving and movement behaviour in a marine capital breeder, the northern elephant seal,Mirounga angustirostris. We assessed the impact of this behavioural variation on foraging success, measured as energy gained at sea.We used principal component analysis to reduce behavioural variables into three principal components that described time in foraging zones (PC1), foraging distance (PC2) and bout structure of dive shapes (PC3).Both intrinsic traits and extrinsic environmental features influenced behaviour and foraging success. Body mass was the sole predictor of residence time in foraging zones (PC1), which, in turn, was the strongest behavioural predictor of foraging efficiency and success over the short postbreeding season. Foraging distance (PC2) significantly varied with year. Since foraging distance is an index of the horizontal and vertical distances seals travel while foraging, we suggest that it was impacted by inter‐annual variation in marine prey distribution. Age had a negligible impact on most aspects of behaviour, except for the structure of dive shapes on the postmoult foraging trip.All principal components significantly impacted rates of energy gain for postbreeding foraging trips when maternal body stores must be recovered quickly before returning to shore to moult. Age impacted the bout structure of dives in pregnant females in a way that influenced success, suggesting a role for previous experience during the long postmoult foraging migration.Strong impacts of body mass on diving ability, foraging success and reproductive effort suggest a proximate mechanism for trade‐offs in the cost of reproduction. Mass lost to current investment in offspring impacts a mother's ability to accrue resources for future offspring.
Contrasting effects of plant inter‐ and intraspecific variation on community‐level trait measures along an environmental gradient
Authors: Kichenin Emilie , Wardle David A. , Peltzer Duane A. , Morse Chris W. , Freschet Grégoire T. 
Published: June 2013

Summary

Despite widespread focus on interspecific variation in trait‐based ecology, there is growing evidence that intraspecific trait variability can play a fundamental role in plant community responses to environmental change and community assembly.

Here, we quantify the strength and direction of inter‐ and intraspecific plant community trait responses along a 900 m elevation gradient spanning alpine and subalpine plant communities in southern New Zealand. We measured five commonly used leaf traits (i.e. dry matter content, N and P concentrations, leaf area and specific leaf area) on all 31 dominant and subordinate species recorded along the gradient, and examined their species‐specific and community‐level responses to elevation using both abundance‐weighted and nonweighted averages of trait values.

By decomposing the variance of community‐level measures of these traits across the gradient, we showed that the contribution of interspecific variation to the response of plant assemblages to elevation was stronger than that of intraspecific variation, for all traits except specific leaf area. Further, the relative contributions of interspecific effects were greater when abundance‐weighted rather than nonweighted measures were used. We also observed contrasting intraspecific trait responses to the gradient among species (particularly for leaf N and P concentrations), and found both positive and negative covariation between inter‐ and intraspecific effects on community‐level trait values.

The weak community‐average trait responses to elevation, as found for specific leaf area (SLA) and leaf N and P concentrations, resulted from strong but opposing responses among vs. within species, which are not typically accounted for in species‐based measures of plant community responses. For instance, increasing elevation (and associated factors such as a decrease in soil nutrient availability) favoured the dominance of species with relatively high leaf nutrient concentrations while simultaneously triggering an intraspecific decrease in the leaf nutrient concentrations of these species.

The context dependency of positive and negative covariation between inter‐ and intraspecific trait variability, and the species‐specific nature of intraspecific shifts in functional trait values, reveal highly complex plastic responses of plants to environmental changes, and highlights the need for greater consideration of the role that intraspecific variation plays in community‐level processes.
Foraging currencies, metabolism and behavioural routines
Authors: Houston Alasdair I. , McNamara John M. 
Published: June 2013

SummaryA fundamental issue in foraging theory is whether it is possible to find a simple currency that characterizes foraging behaviour. If such a currency exists, then it is tempting to argue that the selective forces that have shaped the evolution of foraging behaviour have been understood.We review previous work on currencies for the foraging behaviour of an animal that maximizes total energy gained. In many circumstances, it is optimal to maximize a suitably modified form of efficiency.We show how energy gain, predation and damage can be combined in a single currency based on reproductive value.We draw attention to the idea that hard work may have an adverse effect on an animal's condition. We develop a model of optimal foraging over a day when a forager's state consists of its energy reserves and its condition. Optimal foraging behaviour in our model depends on energy reserves, condition and time of day. The pattern of optimal behaviour depends strongly on assumptions about the probability that the forager is killed by a predator.If condition is important, no simple currency characterizes foraging behaviour, but behaviour can be understood in terms of the maximization of reproductive value. It may be optimal to adopt a foraging option that results in a rate of energy expenditure that is less than the rate associated with maximizing efficiency.
The distribution of below‐ground traits is explained by intrinsic species differences and intraspecific plasticity in response to root neighbours
Authors: Valverde‐Barrantes Oscar J. , Smemo Kurt A. , Feinstein Larry M. , Kershner Mark W. , Blackwood Christopher B. 
Published: June 2013

Summary

Large variation in tree root architecture and morphology has been reported for temperate forest communities. However, it is not clear whether this variation represents adaptation of species to specific soil properties, alternative resource acquisition strategies among co‐occurring species, or canalized traits without a strong impact on the success of individuals in different environments. Here, our goal was to test these alternative hypotheses and quantify how community‐aggregated and intraspecific root trait variations are explained by biotic versus abiotic mechanisms in a temperate deciduous forest.

We conducted our study in an Acer‐Fagus‐dominated forest in north‐east Ohio, USA. Using molecular barcoding techniques, we identified 738 root systems belonging to 14 tree species. We measured seven functional root traits related to root architecture and morphology at the species and community‐aggregated levels.

Although we found significant relationships between soil resource gradients and root trait distributions, intrinsic differences between coexisting species were more important than soil factors in explaining the distribution of root traits in the community. Additionally, root trait variation at the species level was also influenced by the presence of other species within cores.

Community‐aggregated variation was more influenced by the combination of species present than soil properties in each sample, suggesting that biotic interactions play an important role in controlling community root trait distribution.

Synthesis. We propose that root trait differentiation between coexisting species is the result of inherent differences between species and plasticity‐mediated responses to neighbours. Hence, the large variation in root traits reported in temperate forest seems to reflect alternative evolutionary pathways that allow individuals to exploit distinct niches in relatively close proximity.
Photoperiod length paces the temporal orchestration of cell cycle and carbon‐nitrogen metabolism in Crocosphaera watsonii
Authors: Dron Anthony , Rabouille Sophie , Claquin Pascal , Talec Amélie , Raimbault Virginie , Sciandra Antoine 
Published: June 2013

SummaryWe analysed the effect of photoperiod length (PPL) (16:8 and 8:16 h of light–dark regime, named long and short PPL, respectively) on the temporal orchestration of the two antagonistic, carbon and nitrogen acquisitions in the unicellular, diazotrophic cyanobacterium Crocosphaera watsonii strain WH8501 growing diazotrophically. Carbon and nitrogen metabolism were monitored at high frequency, and their patterns were compared with the cell cycle progression. The oxygen‐sensitive N2 fixation process occurred mainly during the dark period, where photosynthesis cannot take place, inducing a light–dark cycle of cellular C : N ratio. Examination of circadian patterns in the cell cycle revealed that cell division occurred during the midlight period, (8 h and 4 h into the light in the long and short PPL conditions, respectively), thus timely separated from the energy‐intensive diazotrophic process. Results consistently show a nearly 5 h time lag between the end of cell division and the onset of N2 fixation. Shorter PPLs affected DNA compaction of C. watsonii cells and also led to a decrease in the cell division rate. Therefore, PPL paces the growth of C. watsonii: a long PPL enhances cell division while a short PPL favours somatic growth (biomass production) with higher carbon and nitrogen cell contents.
The Gac/Rsm and cyclic‐di‐GMP signalling networks coordinately regulate iron uptake in Pseudomonas aeruginosa
Authors: Frangipani Emanuela , Visaggio Daniela , Heeb Stephan , Kaever Volkhard , Cámara Miguel , Visca Paolo , Imperi Francesco 
Published: June 2013

SummaryPseudomonas aeruginosa is a versatile bacterial pathogen capable of occupying diverse ecological niches. To cope with iron limitation, P. aeruginosa secretes two siderophores, pyoverdine and pyochelin, whose ability to deliver iron to the cell is crucial for biofilm formation and pathogenicity. In this study, we describe a link between iron uptake and the Gac/Rsm system, a conserved signal transducing pathway of P. aeruginosa that controls the production of extracellular products and virulence factors, as well as the switch from planktonic to biofilm lifestyle. We have observed that pyoverdine and pyochelin production in P. aeruginosa is strongly dependent on the activation state of the Gac/Rsm pathway, which controls siderophore regulatory and biosynthetic genes at the transcriptional level, in a manner that does not involve regulation of ferric uptake regulator (Fur) expression. Gac/Rsm‐mediated regulation of iron uptake genes appears to be conserved in different P. aeruginosa strains. Further experiments led to propose that the Gac/Rsm system regulates siderophore production through modulation of the intracellular levels of the second messenger c‐di‐GMP, indicating that the c‐di‐GMP and the Gac/Rsm regulatory networks essential for biofilm formation can also coordinately control iron uptake in P. aeruginosa.
Metabolic flexibility of enigmatic SAR324 revealed through metagenomics and metatranscriptomics
Authors: Sheik Cody S. , Jain Sunit , Dick Gregory J. 
Published: June 2013

SummaryChemolithotrophy is a pervasive metabolic lifestyle for microorganisms in the dark ocean. The SAR324 group of Deltaproteobacteria is ubiquitous in the ocean and has been implicated in sulfur oxidation and carbon fixation, but also contains genomic signatures of C1 utilization and heterotrophy. Here, we reconstructed the metagenome and metatranscriptome of a population of SAR324 from a hydrothermal plume and surrounding waters in the deep Gulf of California to gain insight into the genetic capability and transcriptional dynamics of this enigmatic group. SAR324's metabolism is signified by genes that encode a novel particulate hydrocarbon monooxygenase (pHMO), degradation pathways for corresponding alcohols and short‐chain fatty acids, dissimilatory sulfur oxidation, formate dehydrogenase (FDH) and a nitrite reductase (NirK). Transcripts of the pHMO, NirK, FDH and transporters for exogenous carbon and amino acid uptake were highly abundant in plume waters. Sulfur oxidation genes were also abundant in the plume metatranscriptome, indicating SAR324 may also utilize reduced sulfur species in hydrothermal fluids. These results suggest that aspects of SAR324's versatile metabolism (lithotrophy, heterotrophy and alkane oxidation) operate simultaneously, and may explain SAR324's ubiquity in the deep Gulf of California and in the global marine biosphere.
A carbon responsive G‐protein coupled receptor modulates broad developmental and genetic networks in the entomopathogenic fungus, Beauveria bassiana
Authors: Ying Sheng‐Hua , Feng Ming‐Guang , Keyhani Nemat O. 
Published: June 2013

SummaryIn fungi, G‐protein coupled receptors (GPCRs) link ligand/nutrient sensing to growth, mating, developmental/life‐stage activation and pathogenesis. A GPCR was characterized from the entomopathogenic fungus, Beauveria bassiana (BbGPCR3), which links nutrient sensing to stress response and development. ΔBbGPCR3 mutants grew slower on various carbohydrates and displayed increased sensitivity to osmotic, oxidative and cell wall stresses. Gene expression profiling revealed a set of heat‐shock and antioxidant factors that failed to be induced under oxidative stress and aberrant regulation of compatible solute‐forming enzymes and cell wall biosynthesis/remodelling proteins in ΔBbGPCR3 after osmotic stress. Glucose‐specific developmental defects included reduced (> 90%) conidiation and reduced dimorphic transition to the production of yeast‐like blastospores, effects suppressed in media containing trehalose or glycerol, but not by addition of cyclic AMP. Insect bioassays revealed reduced virulence in topical assays but no effect in intrahaemoceol injection assays, indicating that BbGPCR3 was important in sensing signals during the initial interaction with the host but dispensable for post‐penetration events. Comparative gene expression profiling of ΔBbGPCR3 mutants grown in glucose media compared with wild‐type/glucose and ΔBbGPCR3/trehalose grown cells revealed sets of genes misregulated and recovered, respectively. These data link BbGPCR3 to broad developmental and genetic networks that include the major MAP kinase pathways.
Capillary electrophoresis–mass spectrometry reveals the distribution of carbon metabolites during nitrogen starvation in Synechocystis sp. PCC 6803
Authors: Osanai Takashi , Oikawa Akira , Shirai Tomokazu , Kuwahara Ayuko , Iijima Hiroko , Tanaka Kan , Ikeuchi Masahiko , Kondo Akihiko , Saito Kazuki , Hirai Masami Yokota 
Published: June 2013

SummaryNitrogen availability is one of the most important factors for the survival of cyanobacteria. Previous studies on Synechocystis revealed a contradictory situation with regard to metabolism during nitrogen starvation; that is, glycogen accumulated even though the expressions of sugar catabolic genes were widely upregulated. Here, we conducted transcript and metabolomic analyses using capillary electrophoresis–mass spectrometry on Synechocystis sp. PCC 6803 under nitrogen starvation. The levels of some tricarboxylic acid cycle intermediates (succinate, malate and fumarate) were greatly increased by nitrogen deprivation. Purine and pyrimidine nucleotides were markedly downregulated under nitrogen depletion. The levels of 19 amino acids changed under nitrogen deprivation, especially those of amino acids synthesized from pyruvate and phosphoenolpyruvate, which showed marked increases. Liquid chromatography–mass spectrometry analysis demonstrated that the amount of NADPH and the NADPH/NADH ratio decreased under nitrogen depletion. These data demonstrate that there are increases in not only glycogen but also in metabolites downstream of sugar catabolism in Synechocystis sp. PCC 6803 under nitrogen starvation, resolving the contradiction between glycogen accumulation and induction of sugar catabolic gene expression in this unicellular cyanobacterium.
Fertiliser Subsidies and Smallholder Commercial Fertiliser Purchases: Crowding Out, Leakage and Policy Implications for Zambia
Authors: Mason Nicole M. , Jayne Thomas S. 
Published: June 2013

AbstractFertiliser intended for government subsidy programmes is sometimes diverted and sold to farmers at or near market prices. Failure to account for such ‘leakage’ can upwardly bias econometric estimates of the effect of government fertiliser subsidy programmes on total fertiliser use. This paper extends the framework used in earlier studies on the crowding in/crowding out effects of subsidised fertiliser on commercial fertiliser purchases to account for leakage, and then applies it to the case of Zambia. Results suggest that each additional kg of subsidised fertiliser injected into the system increases total fertiliser use by 0.54 kg. Without controlling for leakage, the estimate would have been 0.87, an overestimate of 61%.
Total lunchtime fast food purchases were lower in sodium and saturated fat when nutritionally promoted fast foods were ordered instead of traditional fast foods: A pilot study
Authors: Antoniolli Rachel E. , Atkinson Louise F. , Palmer Michelle A. 
Published: June 2013

AbstractAimThe aim of the study was to compare sodium and saturated fat contents of lunchtime fast food orders containing regular items with those containing items promoted for nutritional attributes (e.g. Subway sandwiches containing 6 g fat or less, McDonald's Heart Foundation Tick approved range).MethodsIn March–April 2010, 907 McDonald's and Subway lunchtime customers (aged 25(16–84) years, 59% M, 73% response rate) in Queensland, Australia were surveyed. Sodium and saturated fat contents of orders were calculated using information from company websites. Independent samples t‐ and chi‐squared tests were used to assess whether orders including nutritionally promoted fast foods contained less sodium and saturated fat, and a chi‐squared test to compare the proportion of customers at each store whose orders exceeded the daily sodium upper limit (2300 mg).ResultsProportionately more customers ordering nutritionally promoted fast foods (n = 24) ordered meals containing ≤1300 mg sodium and ≤6 g saturated fat (83% and 92%, respectively) than those ordering regular fast foods (n = 883, 33% and 24%, respectively, P < 0.02). One‐quarter (24%) of orders—all selected from the regular menu—exceeded the daily sodium upper limit. Proportionately more orders from Subway (40%) exceeded the daily sodium upper limit than from McDonald's (5%, P < 0.001).ConclusionsLunchtime fast food orders may contain less sodium and saturated fat when nutritionally promoted foods are selected. Reformulating all fast foods may be warranted given that fast foods contain high levels of sodium and saturated fat, and nutritionally promoted fast foods may represent only a small proportion of lunchtime choices.