bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of hatching date on parental care, chick growth, and chick mortality in the chinstrap penguin Pygoscelis antarctica
Authors: Vinuela J. , Moreno J. , Carrascal L. M. , Sanz J. J. , Amat J. A. , Ferrer M. , Belliure J. , Cuervo J.
Published: May 2009

We studied the effect of hatching date on breeding performance (chick growth and mortality) and phenology (creching and fledging ages) of the chinstrap penguin during three years. The year affected every variable considered, probably due to pack‐ice persistence and food availability differences between years. Hatching date had slight or no effect on mortality and early growth, but was negatively correlated with creching age, which, in turn, was positively related to final size. The decision to leave the chicks unguarded does not seem to be based on the condition of the chicks, but on that of adults. Fledging age was negatively correlated with hatching date, and this effect was more marked in the year with poor growth performance. Given the short time available for breeding in Antarctica, there must be conflicting pressures between investing in feeding chicks and advancing the period of premoult resource storage, this explaining the strong relationship between hatching dates and subsequent phenological events (creching and fledging). In this kind of study, it may be important to remove the effect of inter‐year variation before assessing the possible effects of other variables.
The evolution of myrmecophagy and its correlates in poison frogs (Family Dendrobatidae)
Authors: Caldwell Janalee P.
Published: May 2009

Poison frogs (Family Dendrobatidae) are common leaf litter inhabitants of New World tropical rainforests. The name of this group derives from several genera (especiallyDendrobates, Minyobates,andPhyllobates) that are aposematically coloured and have toxic skin to varying degrees. Other species in the family, primarily the genusColostethus,are cryptically coloured and non‐toxic. Recent studies have revealed that the toxic compounds in the skin, which are lipophilic alkaloids, may have a dietary origin. Diets and associated characteristics, prey size, prey number, and niche breadth, of nine species in five genera, three of which have poisonous species, were examined. Interpretation of these characteristics in light of an independently constructed cladogram revealed the inclusion of a high percentage of Formicidae (ants) in the diets of toxic species. Although alkaloids have been reported in several insect groups, more alkaloids are known from ants than any other group. Species in the genusDendrobates, which are poisonous and have many other derived characters, have diets composed of 50–73% ants, whereas percentages of ants used by non‐toxic species in the genusColostethuswas 12–16%. Ants are the major prey category consumed by the five poisonous species considered in this study. In general, frogs separated into two groups. More basal groups with non‐toxic skin and cryptic coloration had diets with low percentages of ants, low numbers of prey per individual, and high niche breadths, indicating inclusion of a broad range of prey categories in their diets. Species with poisonous skin and aposematic coloration had diets with large percentages of ants, large numbers of prey per individual, and low niche breadths, indicating diets with relatively few prey categories. Thus, diet, and the subsequent evolution of uptake systems for alkaloids, may be the primary character that led to the development of toxic skin and permitted aposematism, leading to radiation of poisonous species.
Patterns of intestinal parasitism in the mountain gorillaGorilla gorillain the Bwindi‐Impenetrable Forest, Uganda
Authors: Ashford R. W. , Lawson H. , Butynski T. M. , Reid G. D. F.
Published: May 2009

The intestinal parasite fauna of the mountain gorillas of Bwindi—Impenetrable Forest, Uganda was studied by means of faecal examination and a single post‐mortem. The fauna was remarkably uniform between social groups and individuals, showing only slight differences between age groups; there is no evidence of any interaction between the parasites observed. The only protozoa were entodiniomorph ciliates; amoebae and flagellates were absent. Helminths included a single host‐specific cestode species and at least five nematodes, three of which are hostspecific. The closest relatives of the host‐specific parasites are found in ungulates and paenungulates, not in hosts phylogenetically related to the gorilla.

This unique and specialized parasite fauna deserves to be monitored so that any effects of the habituation of the gorillas for tourism can be assessed.
The scaling of the size and stiffness of primary flight feathers
Authors: Worcester S. E.
Published: May 2009

Birds encompass a large range of body sizes, yet the importance of body size on feather morphology and mechanical properties has not been characterized. In this study, I examined the scaling relationships of primary flight feathers within a phylogenetically diverse sample of avian species varying in body size by nearly three orders of magnitude. I measured the scaling relationships between body mass and feather linear dimensions as well as feather flexural stiffness. The resnlts of an independent contrasts analysis to test the effects of phylogenetic history on the characters measured had no effect on the scaling relationships observed. There was slight, but not significant, positive allometry in the scaling of shaft diameter with respect to feather length across a range of body masses. The scaling of feather length and diameter against body mass was not significantly different from isometry. Flexural stiffness, however, exhibited strong negative allometry. Therefore, larger birds have relatively more flexible feathers than smaller birds. The more flexible primary feathers of large birds may reduce stresses on the wing skeleton during take‐off and landing and also make these feathers less susceptible to mechanical failure. Conversely, the greater flexibility of these feathers may also reduce their capacity to generate aerodynamic lift.
Spacing patterns within populations of a tropical forest rodent, Proechimys semispinosus, on five Panamanian islands
Authors: Adler G. H. , Endries M. , Piotter S.
Published: May 2009

Spacing patterns of adult Proechimys semispinosus (Central American spiny rat) within five island populations in central Panamá were determined by live‐trapping over a one‐year period. Home ranges were described by minimum convex polygons for each individual that had a sufficient number of captures to allow accurate description. Home‐range size was calculated as the area of an individual's polygon. The total area of overlap of each individual's home range with every other consexual's home range was also calculated. Mean home‐range size and overlap were compared among islands and between sexes with two‐way analysis of variance and were related to mean density of adult males and females and island size with linear regression analysis. Home‐range size and overlap were also compared while controlling for density using analysis of covariance.

Home‐range size varied between the sexes but not among islands, with males generally having larger home ranges than females. Home‐range size showed a negative relationship to density, and the difference in home‐range size between the sexes prevailed even after controlling for density. Home‐range overlap varied among islands but not between the sexes. There was no linear relationship between overlap and density, although individuals within two low‐density populations had nearly exclusive home ranges. The high degree of overlap among home ranges within some populations suggests that P. semispinosus do not maintain large exclusive territories. Such territories may be economically indefensible because of the spatial and temporal distribution of resources (i.e. primarily falling fruit). Although theory predicts that spatially patchy and poorly renewable resources promote territoriality, resources in tropical forests of the study area may be randomly or too patchily distributed or ephemeral to permit maintenance of territories that span a large portion of an animal's home range. More detailed study is necessary to reveal finer‐scale patterns of territoriality (e.g. defence of burrows or concentrations of fallen fruit).
Mineralization and wear of mandibular first molars in red deer (Cervus elaphus) of known age
Authors: Kierdorf U. , Becher J.
Published: May 2009

The degree of dental wear was measured in 41 mandibular first molars from red deer of known age (range 2–18 years). The calculated wear indices were positively correlated with age (r= 0.780, P < 0.001). In the same sample, significant (P < 0.001) differences in hardness (determined by microhardness testing) were observed between enamel and coronal dentine as well as between outer and inner enamel and dentine, respectively. In animals belonging to the same age group (three‐year‐olds, n= 11), a negative correlation (r= ‐0.830, P= 0.0016) was found between wear index and maximum mean enamel hardness. In a sample of five specimens from this age group, a negative correlation (r= ‐0.918, P= 0.028) between maximum calcium concentration of enamel (measured by electron microprobing) and wear index was also recorded. We concluded that the intensity of enamel mineralization had a decisive effect on the degree of dental wear. Measuring of enamel hardness and subsequent modification of wear scores or indices is therefore recommended for future studies on the relationship between age and the degree of dental attrition in deer.
Spatial ecology of the European wildcat in a Mediterranean ecosystem: dealing with small radio‐tracking datasets in species conservation
Authors: Monterroso P. , Brito J. C. , Ferreras P. , Alves P. C.
Published: May 2009

Despite some populations of European wildcat Felis silvestris in central Europe are stable or increasing, the Iberian subpopulation is in decline and is listed as ‘vulnerable’. In Portugal, little is known about wildcat populations, making conservation policies extremely difficult to define. Furthermore, the secretive behaviour of these mammals, along with low population densities, make data collection complicated. Thus, it is crucial to develop efficient analytical tools to interpret existing data for this species. In this study, we determine the home‐range size and environmental factors related to wildcat spatial ecology in a Mediterranean ecosystem using a combined analysis of habitat selection and maximum entropy (Maxent) modelling. Simultaneously, we test the feasibility of using radio‐tracking locations to construct an ecologically meaningful distribution model. Six wildcats were captured and tracked. The average home‐range size (MCP95) was 2.28 km2 for females and 13.71 km2 for one male. The Maxent model built from radio‐tracking locations indicated that the abundance of the European rabbit Oryctolagus cuniculus and limited human disturbance were the most important correlates of wildcat presence. Habitat selection analysis revealed that wildcats tend to use scrubland areas significantly more than expected by chance. A mosaic of scrublands and agricultural areas, with a higher proportion of the former, benefits wildcat presence in the study area; however, species distribution is mainly constrained by availability of prey and resting sites. The Maxent model validation with camera‐trapping data indicated that highly adequate model performance. This technique may prove useful for recovering small radio‐tracking datasets as it provides a new alternative for handling data and maximizing the ecological information on a target population, which can then be used for conservation planning.
The Parkinson disease‐associated A30P mutation stabilizes α‐synuclein against proteasomal degradation triggered by heme oxygenase‐1 over‐expression in human neuroblastoma cells
Authors: Song Wei , Patel Amar , Qureshi Hamid Y. , Han Dong , Schipper Hyman M. , Paudel Hemant K.
Published: May 2009

Proteosomal degradation of proteins is one of the major mechanisms of intracellular protein turnover. Failure of the proteosome to degrade misfolded protein is implicated in the accumulation of α‐synuclein in Parkinson’s disease (PD). Heme oxygenase‐1 (HO‐1), an enzyme that converts heme to free iron, carbon monoxide (CO) and biliverdin (bilirubin precursor) is expressed in response to various stressors. HO‐1 is up‐regulated in PD‐ and Alzheimer’s disease‐affected neural tissues. In this study, we found that HO‐1 over‐expression engenders dose‐dependent decreases in α‐synuclein protein levels in human neuroblastoma M17 cells. When over‐expression of HO‐1 was silenced in HO‐1 transfected cells, level of α‐synuclein was restored. Likewise, treatment of HO‐1 over‐expressing cells with the HO‐1 inhibitor, tin mesoporphyrin, the iron chelator deferoxamine or antagonist of CO‐dependent cGMP activation, methylene blue, mitigated the HO‐1‐induced reduction in α‐synuclein levels. Furthermore, when HO‐1 over‐expressing cells were treated with the proteosome inhibitors, lactacystin and MG132, level of α‐synuclein was almost completely restored. In contrast to the effect on α‐synuclein [wild‐type (WT)] levels, HO‐1 over‐expression did not significantly impact PD‐associated α‐synuclein (A30P) levels in these cells. HO‐1 also significantly reduced aggregation of α‐synuclein (WT) but not that of A30P. Our results suggest that HO‐1, which is expressed when neurons are exposed to toxic stimuli capable of inducing protein misfolding, triggers proteosomal degradation of proteins and prevents intracellular accumulation of protein aggregates and inclusions. Resistance to HO‐1 induced proteosomal degradation may render the familial PD‐associated A30P mutation prone to toxic intracellular aggregation.
Well‐being of mothers with children in Finnish low‐income families – the mother’s point of view
Authors: Vuori Anne , Åstedt‐Kurki Päivi
Published: May 2009

Introduction:  Low income correlates with increased health risks. The well‐being of low‐income families has received only limited attention in nursing research and most of the work has focused on unearthing their problems rather than on identifying their strengths. This article describes the well‐being of mothers with children in Finnish low‐income families, from a family health point of view.

Aims:  The aim of this study was to generate description of the well‐being of mothers with children in low‐income families in their everyday life and interpret and understand it from the perspectives of low‐incomes mothers.

Methods:  This study is based on the phenomenological method and the informants consisted of 15 mothers of low‐income families with children. The data were collected in 2004–2005. The mothers were recruited from three municipalities by means of purposive sampling from amongst families in receipt of income support. Ethical approval was obtained.

Findings:  Well‐being appears as a complex and multifaceted phenomenon which, in addition to health, is understood as the opposite of illness and experienced health involves dimensions related to the family’s everyday life and situation. Mothers’ well‐being is described in terms of the flow of everyday life, meaningful family activities, everyday health, the existence of a network of significant others, internal family functioning, the strength received from motherhood and being in the position to influence the well‐being of one’s family.

Conclusions:  The results suggest that for purposes of supporting family well‐being on the family’s own terms, it is important to have a clear understanding of the everyday life of families in different situations and understand the meanings that grow out of their everyday life. This information helps nurses to take into account the social aspect of family health and understand low‐income mothers’ point of health, in different health situations in nursing practice where they meet one another.
Vibration Analysis at Microscale by Talbot Fringe Projection Method1
Authors: Rodriguez‐Vera R. , Genovese K. , Rayas J. A. , Mendoza‐Santoyo F.
Published: May 2009

Abstract:  This work focuses on the implementation of a structured light projection technique for the analysis of the 3D vibration modes of microsamples. The Talbot image of a Ronchi grating is projected onto the sample surface passing through one of the objective tube of a stereomicroscope thus realising a fringe projection system at a micrometric scale. An aluminium cantilever beam PZT‐driven into harmonic vibration served as test sample for investigating the possibility to get the full‐field vibration modes of micro‐objects. An automated Fourier transform analysis of the fringe patterns was performed to obtain the full‐field time‐resolved profile information of the sample at each frame delivered by a high‐speed camera with a micrometric resolution. A straightforward procedure for retrieving resonance frequency for different modes and vibration amplitudes along the whole sample surface was implemented. The great sensitivity and the full‐field capacities of the proposed experimental procedure allow to put in evidence differences between real and theoretical behaviours hence could be extremely useful for designing and testing structural dynamic response of microstructures and micro–electro–mechanical Systems.
Experimental Determination of the Q‐factors of Microcantilevers Coated With Thin Metal Films
Authors: Klempner A. R. , Marinis R. T. , Hefti P. , Pryputniewicz R. J.
Published: May 2009

Abstract:  Microelectromechanical systems (MEMS) are typically fabricated out of materials that are mechanically sound at the microscale, but can be relatively poor electrical conductors. For this reason, areas of MEMS can be coated with various thin metal films to provide electrical pathways. These films, however, may drastically alter mechanical properties of the device. In this paper we investigate how metallization of microcantilevers affects the quality factors, (Q). Using two sets of silicon microcantilevers that are coated with aluminium films from 5 nm to 30 nm thick, on one side and two sides, respectively, the Q‐factors are experimentally determined using the ring‐down method. The ring‐down method entails mechanically exciting the microcantilevers at their fundamental resonance frequency, abruptly stopping the excitation, and then measuring the decay of oscillation amplitude as a function of time. From this ring‐down curve, the Q‐factor of each microcantilever can be determined. Results show that the greater the thickness of the aluminium film, the lower the Q‐factor will be. We also show a significant temperature dependency of the Q‐factor of aluminium coated microcantilevers.
Damage Progression Using Speckle‐Correlation and High‐Speed Imaging for Survivability of Leadfree Packaging Under Shock
Authors: Lall P. , Iyengar D. , Shantaram S. , Panchagade D.
Published: May 2009

Abstract:  In this paper, a methodology to predict failure of electronics under shock and vibration loads has been investigated. Reliability prediction models have been developed using optical feature extraction techniques for 6‐leadfree solder alloy systems. Solder alloy systems investigated include, Sn1Ag0.5Cu, Sn3Ag0.5Cu, Sn0.3Ag0.7Cu, Sn0.3Ag0.7Cu0.1Bi, Sn0.2Ag0.7Cu0.1Bi‐0.1Ni, 96.5Sn3.5Ag. Previously, Digital Image Correlation (DIC) has been used for measurement of thermally‐induced deformation and material characterisation. In this paper, DIC has been used for transient dynamic measurements, and optical feature extraction. Board assemblies have been subjected to shock‐impact in various orientations including the zero‐degree JEDEC drop and the vertical free‐drop. Transient deformation has been measured using both DIC and the strain gages. Measurements have been taken on both the package and the board side of the assemblies. Accuracy of high‐speed optical measurement has been compared with that from discrete strain gages. Package architectures examined include‐flex ball‐grid arrays, tape‐array ball‐grid arrays, and metal lead‐frame packages. Explicit finite‐element models have been developed and correlated with experimental data. Three models were developed: smeared property models: Timoshenko‐beam models: and explicit sub‐models. The potential of damage identification and tracking for various solder alloys has been investigated. Data on the identification of damage proxies for competing failure mechanisms at the copper‐to‐solder, solder‐to‐printed circuit board, and copper‐to‐package substrate has been presented. Design envelopes have been developed based on Statistical Pattern Recognition (SPR). The design‐envelope is intended for component integration to ensure survivability in shock and vibration environments at a user‐specified confidence level.
Does Corporate Transparency Contribute to Efficient Resource Allocation?
Authors: FRANCIS JERE R. , HUANG SHAWN , KHURANA INDER K. , PEREIRA RAYNOLDE
Published: May 2009

This paper examines whether a country's corporate transparency environment, which includes the quality of accounting information, contributes to efficient resource allocation. Based on a cross‐country study of 37 manufacturing industries in 37 countries, we provide three pieces of related evidence. First, we find the contemporaneous correlations in industry growth rates across country pairs are higher when there is a greater level of corporate transparency in the country pairs, after controlling for country‐level economic and financial development. Second, we find the influence of transparency on these correlations is stronger when country pairs are at similar levels of economic development (GDP). Finally, when we control for the level of transparency explained by a country's institutions in place, we find that residual transparency (unexplained by country‐level factors) is associated with industry‐specific growth rates. Taken together, the results are consistent with corporate transparency facilitating the allocation of resources across industry sectors.
Which Microfinance Institutions Are Becoming More Cost Effective with Time? Evidence from a Mixture Model
Authors: CAUDILL STEVEN B. , GROPPER DANIEL M. , HARTARSKA VALENTINA
Published: May 2009

Microfinance institutions (MFIs) play a key role in many developing countries. Utilizing data from Eastern Europe and Central Asia, MFIs are found to generally operate with lower costs the longer they are in operation. Given the differences in operating environments, subsidies, and organizational form, this finding of increasing cost effectiveness may not aptly characterize all MFIs. Estimation of a mixture model reveals that roughly half of the MFIs are able to operate with reduced costs over time, while half do not. Among other things, we find that larger MFIs offering deposits and those receiving lower subsidies operate more cost effectively over time.
Can Affine Term Structure Models Help Us Predict Exchange Rates?
Authors: DE LOS RIOS ANTONIO DIEZ
Published: May 2009

This paper proposes an arbitrage‐free model to extract the information that the term structure of forward premia contains for forecasting future spot exchange rates. Using monthly data on four U.S. dollar bilateral exchange rates, we find evidence that this model provides statistically better forecasts than those produced by a random walk for the British pound and Canadian dollar exchange rates. Negative results for the German mark/Euro and Swiss franc are explained by a rejection of the restrictions imposed by the term structure model.
Information Immobility and the Home Bias Puzzle
Authors: VAN NIEUWERBURGH STIJN , VELDKAMP LAURA
Published: May 2009

Many argue that home bias arises because home investors can predict home asset payoffs more accurately than foreigners can. But why does global information access not eliminate this asymmetry? We model investors, endowed with a small home information advantage, who choose what information to learn before they invest. Surprisingly, even when home investors can learn what foreigners know, they choose not to: Investors profit more from knowing information others do not know. Learning amplifies information asymmetry. The model matches patterns of local and industry bias, foreign investments, portfolio outperformance, and asset prices. Finally, we propose new avenues for empirical research.
Determinants of Vertical Integration: Financial Development and Contracting Costs
Authors: ACEMOGLU DARON , JOHNSON SIMON , MITTON TODD
Published: May 2009

We study the determinants of vertical integration in a new data set of over 750,000 firms from 93 countries. We present a number of theoretical predictions on the interactions between financial development, contracting costs, and the extent of vertical integration. Consistent with these predictions, contracting costs and financial development by themselves appear to have no effect on vertical integration. However, we find greater vertical integration in countries that have both greater contracting costs and greater financial development. We also show that countries with greater contracting costs are more vertically integrated in more capital‐intensive industries.
Eat or Be Eaten: A Theory of Mergers and Firm Size
Authors: GORTON GARY , KAHL MATTHIAS , ROSEN RICHARD J.
Published: May 2009

We propose a theory of mergers that combines managerial merger motives with an industry‐level regime shift that may lead to value‐increasing merger opportunities. Anticipation of these merger opportunities can lead to defensive acquisitions, where managers acquire other firms to avoid losing private benefits if their firms are acquired, or “positioning” acquisitions, where firms position themselves as more attractive takeover targets to earn takeover premia. The identity of acquirers and targets and the profitability of acquisitions depend on the distribution of firm sizes within an industry, among other factors. We find empirical support for some unique predictions of our theory.
Oil Futures Prices in a Production Economy with Investment Constraints
Authors: KOGAN LEONID , LIVDAN DMITRY , YARON AMIR
Published: May 2009

We document a new stylized fact, that the relationship between the volatility of oil futures prices and the slope of the forward curve is nonmonotone and has a V‐shape. This pattern cannot be generated by standard models that emphasize storage. We develop an equilibrium model of oil production in which investment is irreversible and capacity constrained. Investment constraints affect firms' investment decisions and imply that the supply elasticity changes over time. Since demand shocks must be absorbed by changes in prices or changes in supply, time‐varying supply elasticity results in time‐varying volatility of futures prices. Estimating this model, we show it is quantitatively consistent with the V‐shape relationship between the volatility of futures prices and the slope of the forward curve.
IPO Underpricing over the Very Long Run
Authors: CHAMBERS DAVID , DIMSON ELROY
Published: May 2009

A central measure of the efficiency of the Initial Public Offering (IPO) market is the extent to which issues are underpriced. We present new and comprehensive evidence covering British IPOs since World War I. During the period from 1917 to 1945, public offers were underpriced by an average of only 3.80%, as compared to 9.15% in the period from 1946 to 1986, and even more after the U.K. stock market was deregulated in 1986. The post‐WWII rise in underpricing cannot be attributed to changes in firm composition, and occurred in spite of improvements in regulation, disclosure, and the prestige of IPO underwriters.
Bayesian Methods for Examining Hardy–Weinberg Equilibrium
Authors: Wakefield Jon
Published: May 2009

Summary Testing for Hardy–Weinberg equilibrium is ubiquitous and has traditionally been carried out via frequentist approaches. However, the discreteness of the sample space means that uniformity of p‐values under the null cannot be assumed, with enumeration of all possible counts, conditional on the minor allele count, offering a computationally expensive way of p‐value calibration. In addition, the interpretation of the subsequent p‐values, and choice of significance threshold depends critically on sample size, because equilibrium will always be rejected at conventional levels with large sample sizes. We argue for a Bayesian approach using both Bayes factors, and the examination of posterior distributions. We describe simple conjugate approaches, and methods based on importance sampling Monte Carlo. The former are convenient because they yield closed‐form expressions for Bayes factors, which allow their application to a large number of single nucleotide polymorphisms (SNPs), in particular in genome‐wide contexts. We also describe straightforward direct sampling methods for examining posterior distributions of parameters of interest. For large numbers of alleles at a locus we resort to Markov chain Monte Carlo. We discuss a number of possibilities for prior specification, and apply the suggested methods to a number of real datasets.
Bayesian Quantile Regression for Longitudinal Studies with Nonignorable Missing Data
Authors: Yuan Ying , Yin Guosheng
Published: May 2009

Summary We study quantile regression (QR) for longitudinal measurements with nonignorable intermittent missing data and dropout. Compared to conventional mean regression, quantile regression can characterize the entire conditional distribution of the outcome variable, and is more robust to outliers and misspecification of the error distribution. We account for the within‐subject correlation by introducing a ℓ2 penalty in the usual QR check function to shrink the subject‐specific intercepts and slopes toward the common population values. The informative missing data are assumed to be related to the longitudinal outcome process through the shared latent random effects. We assess the performance of the proposed method using simulation studies, and illustrate it with data from a pediatric AIDS clinical trial.
GARP: a key receptor controlling FOXP3 in human regulatory T cells
Authors: Probst‐Kepper M. , Geffers R. , Kröger A. , Viegas N. , Erck C. , Hecht H.‐J. , Lünsdorf H. , Roubin R. , Moharregh‐Khiabani D. , Wagner K. , Ocklenburg F. , Jeron A. , Garritsen H. , Arstila T.P. , Kekäläinen E. , Balling R. , Hauser H. , Buer J. , Weiss S.
Published: May 2009

Recent evidence suggests that regulatory pathways might control sustained high levels of FOXP3 in regulatory CD4+CD25hi T (Treg) cells. Based on transcriptional profiling of ex vivo activated Treg and helper CD4+CD25− T (Th) cells we have identified GARP (glycoprotein‐A repetitions predominant), LGALS3 (lectin, galactoside‐binding, soluble, 3) and LGMN (legumain) as novel genes implicated in human Treg cell function, which are induced upon T‐cell receptor stimulation. Retroviral overexpression of GARP in antigen‐specific Th cells leads to an efficient and stable re‐programming of an effector T cell towards a regulatory T cell, which involves up‐regulation of FOXP3, LGALS3, LGMN and other Treg‐associated markers. In contrast, overexpression of LGALS3 and LGMN enhance FOXP3 and GARP expression, but only partially induced a regulatory phenotype. Lentiviral down‐regulation of GARP in Treg cells significantly impaired the suppressor function and was associated with down‐regulation of FOXP3. Moreover, down‐regulation of FOXP3 resulted in similar phenotypic changes and down‐regulation of GARP. This provides compelling evidence for a GARP‐FOXP3 positive feedback loop and provides a rational molecular basis for the known difference between natural and transforming growth factor‐β induced Treg cells as we show here that the latter do not up‐regulate GARP. In summary, we have identified GARP as a key receptor controlling FOXP3 in Treg cells following T‐cell activation in a positive feedback loop assisted by LGALS3 and LGMN, which represents a promising new system for the therapeutic manipulation of T cells in human disease.
High sensitivity of both sequencing and real‐time PCR analysis of KRAS mutations in colorectal cancer tissue
Authors: Tol Jolien , Dijkstra Jeroen R. , Vink‐Börger Marianne E. , Nagtegaal Iris D. , Punt Cornelis J.A. , Van Krieken Johan H.J.M. , Ligtenberg Marjolijn J.L.
Published: May 2009

The KRAS mutation status predicts the outcome of treatment with epidermal growth factor receptor targeted agents, and therefore the testing for KRAS mutations has become an important diagnostic procedure. To optimize the quality of this test, we compared the results of the two most commonly used KRAS mutation tests, cycle sequencing and a real‐time PCR‐based assay, in DNA extracted from formalin‐fixed paraffin‐embedded (FFPE) colorectal cancer samples of 511 patients. The results were interpreted in the context of the tumour cell percentage and the assay parameters. In 510 samples KRAS mutation status assessment was successful. A KRAS mutation was detected in 201 tumours (39.4%). Sequencing and the real‐time PCR‐based assay generated the same result in 486 samples (95.3%). The sequencing result was considered false positive in one (0.2%) and false negative in nine samples (1.8%). The assay result was considered false positive in six (1.2%) and false negative in seven samples (1.4%). Explanations for discrepant test results were a higher sensitivity of the assay in samples with a low tumour cell percentage, occurrence of mutations that are not covered by the assay and δ Ct values approximating the cut‐off value of the assay. In conclusion, both sequencing and the real‐time PCR‐based assay are reliable tests for KRAS mutation analysis in FFPE colorectal cancer samples, with a sensitivity of 95.5% (95% confidence interval [CI] 91.7–97.9%) and 96.5% (95% CI 93.0–98.6%), respectively. The real‐time PCR based assay is the method of choice in samples with a tumour cell percentage below 30%.
Molecular characterization of CTX‐M‐15‐producing clinical isolates of Escherichia coli reveals the spread of multidrug‐resistant ST131 (O25:H4) and ST964 (O102:H6) strains in Norway
Authors: NASEER UMAER , HALDORSEN BJØRG , TOFTELAND STÅLE , HEGSTAD KRISTIN , SCHEUTZ FLEMMING , SIMONSEN GUNNAR SKOV , SUNDSFJORD ARNFINN ,   THE NORWEGIAN ESBL STUDY GROUP
Published: May 2009

Nationwide, CTX‐M‐producing clinical Escherichia coli isolates from the Norwegian ESBL study in 2003 (n=45) were characterized on strain and plasmid levels. BlaCTX‐M allele typing, characterization of the genetic environment, phylogenetic groups, pulsed field gel electrophoresis (PFGE), serotyping and multilocus sequence typing were performed. Plasmid analysis included S1‐nuclease‐PFGE, polymerase chain reaction‐based replicon typing, plasmid transfer and multidrug resistance profiling. BlaCTX‐M‐15 (n=23; 51%) and blaCTX‐M‐14 (n=11; 24%) were the major alleles of which 18 (78%) and 6 (55%), respectively, were linked to ISEcp1. Thirty‐two isolates were of phylogenetic groups B2 and D. Isolates were of 29 different XbaI‐PFGE‐types including six regional clusters. Twenty‐three different O:H serotypes were found, dominated by O25:H4 (n=9, 20%) and O102:H6 (n=9, 20%). Nineteen different STs were identified, where ST131 (n=9, 20%) and ST964 (n=7, 16%) were dominant. BlaCTX‐M was found on ≥100 kb plasmids (39/45) of 10 different replicons dominated by IncFII (n=39, 87%), FIB (n=20, 44%) and FIA (n=19, 42%). Thirty‐nine isolates (87%) displayed co‐resistance to other classes of antibiotics. A transferable CTX‐M phenotype was observed in 9/14 isolates. This study reveals that the majority of CTX‐M‐15‐expressing strains in Norway are part of the global spread of multidrug‐resistant ST131 and ST‐complex 405, associated with ISEcp1 on transferrable IncFII plasmids.
Egg patterning is not a reliable indicator of intraspecific brood parasitism in the blue tit Cyanistes caeruleus
Authors: Griffith Simon C. , Barr Iain , Sheldon Ben C. , Rowe Louise V. , Burke Terry
Published: May 2009

A recent study reported the incidence of intraspecific brood parasitism (IBP) in the blue tit, based on differences in pigmentation between eggs within clutches and the appearance of multiple eggs within a nest in a single day. Here we present data from another population of blue tits Cyanistes caeruleus in which we show that such evidence is not necessarily indicative of IBP. As in many other studies of birds, we found that the patterning and degree of pigmentation on eggs is individually highly characteristic of a female. As in the previous study of blue tits, a minority of clutches (about 3% of 904 clutches) contained one, two or three eggs that were distinctly different from the other eggs in the clutch, either in size or patterning, but not both. Molecular genetic analyses of parentage in a sample of these clutches with suspected IBP demonstrated unequivocally that all eggs within each clutch had in fact been laid by a single female, in all cases the social parent. We also found no evidence of IBP from paternity analyses of a sample of 3,529 offspring from 427 broods in this population, adding to previous evidence of the absence of IBP in this species. These findings cast doubt on the utility of purely observational approaches to provide evidence of intraspecific brood parasitism; our study suggests that egg morphology and records of laying patterns are inadequate to enable the identification of IBP.
Estimated plant richness pattern across northwest South America provides similar support for the species‐energy and spatial heterogeneity hypotheses
Authors: Jiménez Iván , Distler Trisha , Jørgensen Peter M.
Published: May 2009

Explaining geographic variation in plant species richness at broad spatial scales has long been a major challenge. Many hypotheses have been proposed during the last 200 yr, but recent work has focused on a few major alternatives. Among these, two hypotheses contend that plant species richness reflects 1) variation in energy and water availability among sampling units (the species‐energy hypothesis) and 2) habitat and topographic heterogeneity within sampling units (the spatial heterogeneity hypothesis). We used a large botanical database and regression models to simultaneously confront the predictions from both hypotheses against an estimate of vascular plant richness across northwest South America. This estimate provided similar support for both hypotheses, a result that may be seen as contrasting with the notion that variation in energy and water availability among sampling units is the main determinant of plant species richness. We discuss potential explanations for this apparent discrepancy. Regression models that incorporated the relative contributions of both hypotheses predicted that the highest plant species richness in northwest South America is found in topographically complex areas. In contrast to several of the most recent mapping efforts, lowland Amazonia was predicted to be a plant richness trough in the study region. We suggest that diverging portrayals of plant richness across northwest South America result from differences in estimates of the relative importance of the species‐energy and the spatial heterogeneity hypotheses.
Environmental drivers of beta‐diversity patterns in New‐World birds and mammals
Authors: Melo Adriano S. , Rangel Thiago Fernando L. V. B. , Diniz‐Filho José Alexandre F.
Published: May 2009

Current macroecological research places great emphasis on patterns of species richness (alpha diversity) and the underlying ecological and evolutionary processes involved in their origin and maintenance. However, few studies dealing with continental scales have addressed dissimilarities in species composition among areas (beta diversity). Using data for the occurrence of 3836 bird and 1641 mammal species in 4220 cells covering the New World, we assessed whether broad‐scale macroecological patterns in beta diversity are related to dissimilarities in environmental variables and biotic units. We employed spatial regression and tree regression to model beta diversity. Difference in altitude was the best predictor of beta diversity. Accordingly, the highest beta diversity values were found in mountainous areas, particularly in the Andes, Central America and western North America. Explanatory variables related to transitions between biotic units (biome, ecoregion) were relatively unimportant. Areas that differ in altitude from their surroundings harbor different sets of species, and this may reflect either species adaptation to particular environmental conditions by range shifts, or species divergence by vicariance, or both.
Erythrocyte polymorphisms in five ethnic groups of Northern Côte d’Ivoire
Authors: Santovito A. , Burgarello C. , Cervella P. , Ouattara M. , Caravatti G. A. , Salvarani B. , Delpero M.
Published: May 2009

Distribution of some erythrocyte polymorphisms was investigated in five Northern Côte d’Ivoire ethnic groups. For the ABO blood group system, the frequencies of alleles p, q and r were 0.119, 0.150 and 0.731, respectively, while the frequencies of alleles D and d of the Rh blood group system were 0.726 and 0.274, respectively. These values are consistent with published data, while the high incidence of HbAS genotype could result from microevolutionay trends acting on this relatively small population. No 27‐bp Southeast Asian ovalocytosis gene deletion was found in the sample.
Argentine rangeland quality influences reproduction of yearling pregnant heifers?
Authors: Hidalgo Liliana G. , Cauhépé M. A.
Published: May 2009

The Flooding Pampa natural grasslands are gradually being transformed into croplands to increase the economic returns of ranches. It is therefore becoming necessary for stockmen to increase beef cattle efficiency to compete with crops and to maintain the native grassland and its associated fauna. However, natural grasslands during winter have the lowest content of nutrients of the year. We intend to demonstrate that, with breeding weights of over 65% of cow mature weight, low forage quality of rangelands during winter does not have a negative effect on reproduction. These higher breeding weights were obtained by selecting early born female calves and by grazing annual and cultivated pastures. Pregnant Aberdeen Angus yearling heifers (n = 90) were evaluated using a pregnancy test (May 2005) until the second calving (July 2006). At the beginning of the experiment, yearling heifers with live weight ranging 360–514 kg (mean, 425 kg ± 3.5 SE) were used. Cattle grazed native grasslands (humid mesophytic meadows and humid prairie grasslands) and old mixed pastures. The second pregnancy was high (100%), with the same mean calving date as in the first pregnancy (227 Julian days). Heifers which calved later in the first calving year were early calvers in the second year, resulting in the relatively constant average calving dates across the animals.
Grazing exclusion as a conservation measure in a South Australian temperate native grassland
Authors: Souter Nicholas J. , Milne Tim
Published: May 2009

Many of South Australia's remnant temperate native grasslands are degraded by introduced livestock grazing. As a conservation measure, grazing was excluded from three 50 × 50 m exclosures in grazed native grassland. After 4 years, grazing removal had a noticeable effect on the grassland structure, increasing basal vegetation cover. Grazing removal had no significant effect on either native or exotic species richness, rather differences in richness changed as a result of interannual differences, such as the amount of rainfall that fell in the growing season. The percent cover of the native tussock grass Austrostipa spp. and the introduced annual grass Avena barbata, whilst fluctuating from year to year, both increased following the removal of grazing. Multivariate analyses showed that whilst only interannual differences affected community taxon richness, changes in structure were affected by the interaction between grazing treatment and year. Excluding livestock from a degraded grassland resulted in limited recovery and restoration of these endangered plant associations will require active rehabilitation efforts.
Reduction of rat damage to forage paddy rice stored as round‐baled silage by modifying the storage layout
Authors: Kawamoto Hidenori , Kimura Shoichi , Komatsu Tokushi , Oshibe Akinori , Shimada Takuya
Published: May 2009

We investigated a method for protecting forage paddy rice, stored as wrapped round‐baled silage, from feeding damage caused by rats. We divided 23 bales (diameter of each bale, 50 cm) into two groups. In the control layout group, the bales were placed in close proximity to each other and the top part was covered by a blue plastic sheet in order to produce a masking effect of vertically stacked bales. In the spacious layout group, the bales were placed 20–30 cm apart from each other. The percentage of bales damaged by feeding in the control layout was 80%, while that of bales damaged by feeding in the spacious layout was only 7%. The result suggested that creating open spaces between the stored bales would increase the predation hazard of rats and reduce the damage caused to the silage.
The migration of nearby spirals from the blue to red sequence: AGN feedback or environmental effects?
Authors: Hughes T. M. , Cortese L.
Published: May 2009

We combine ultraviolet to near-infrared photometry with Hi 21cm line observations for a complete volume-limited sample of nearby galaxies in different environments (from isolated galaxies to Virgo cluster members), to study the migration of spirals from the blue to the red sequence. Although our analysis confirms that, in the transition region between the two sequences, a high fraction of spirals host active galactic nuclei (AGN), it clearly shows that late types with quenched star formation are mainly Hi deficient galaxies preferentially found in the Virgo cluster. This not only suggests that environmental effects could play a significant role in driving the migration of local galaxies from the blue sequence, but it also implies that a physical link between AGN feedback and quenching may not be assumed from a correlation between nuclear activity and colour.
The Founding of the Association for Psychological Science: Part 2. The Tipping Point and Early Years
Authors: Cautin Robin L.
Published: May 2009

The founding of the Association for Psychological Science (APS) occurred in the context of longstanding dialectical tensions within organized psychology. It represents the most recent breakaway effort from the American Psychological Association (APA), psychology's parent association in the United States. Beginning in the 1970s, numerous APA committees deliberated the Association's structure, making recommendations designed to appease the various constituencies within the changing organization; all but the last of these proposals were ultimately rejected by the APA Council. In 1987, the Assembly for Scientific and Applied Psychologists (ASAP) formed to encourage APA reorganization, and in early 1988, the APA Council approved a reorganization plan; that plan was, however, rejected by the membership. In August 1988, the ASAP became the APS. The early years of the APS were shaped by challenges and successes that would lay the groundwork for the APS to become a prominent organization in the promotion of scientific psychology. An understanding of these events may provide insight into the nature of organized psychology and its future.
Understanding the Links Between Social Support and Physical Health: A Life-Span Perspective With Emphasis on the Separability of Perceived and Received Support
Authors: Uchino Bert N.
Published: May 2009

Social support has been reliably related to physical health outcomes. However, the conceptual basis of such links needs greater development. In this article, I argue for a life-span perspective on social support and health that takes into account distinct antecedent processes and mechanisms that are related to measures of support over time. Such a view highlights the need to distinguish measures of perceived and received support and its links to more specific diseases (e.g., chronic, acute) and stages of disease development (e.g., incidence). I discuss both the novel implications of these theoretical arguments for research on social support and physical health, as well as the potential intervention approaches that are apparent from this perspective.