bluuebunny/crossref_metadata_2025_split huggingface dataset:
Climate change, breeding date and nestling diet: how temperature differentially affects seasonal changes in pied flycatcher diet depending on habitat variation
Authors: Burger Claudia , Belskii Eugen , Eeva Tapio , Laaksonen Toni , Mägi Marko , Mänd Raivo , Qvarnström Anna , Slagsvold Tore , Veen Thor , Visser Marcel E. , Wiebe Karen L. , Wiley Chris , Wright Jonathan , Both Christiaan 
Published: February 2012

Summary1. Climate warming has led to shifts in the seasonal timing of species. These shifts can differ across trophic levels, and as a result, predator phenology can get out of synchrony with prey phenology. This can have major consequences for predators such as population declines owing to low reproductive success. However, such trophic interactions are likely to differ between habitats, resulting in differential susceptibility of populations to increases in spring temperatures. A mismatch between breeding phenology and food abundance might be mitigated by dietary changes, but few studies have investigated this phenomenon. Here, we present data on nestling diets of nine different populations of pied flycatchers Ficedula hypoleuca, across their breeding range. This species has been shown to adjust its breeding phenology to local climate change, but sometimes insufficiently relative to the phenology of their presumed major prey: Lepidoptera larvae. In spring, such larvae have a pronounced peak in oak habitats, but to a much lesser extent in coniferous and other deciduous habitats.2. We found strong seasonal declines in the proportions of caterpillars in the diet only for oak habitats, and not for the other forest types. The seasonal decline in oak habitats was most strongly observed in warmer years, indicating that potential mismatches were stronger in warmer years. However, in coniferous and other habitats, no such effect of spring temperature was found.3. Chicks reached somewhat higher weights in broods provided with higher proportions of caterpillars, supporting the notion that caterpillars are an important food source and that the temporal match with the caterpillar peak may represent an important component of reproductive success.4. We suggest that pied flycatchers breeding in oak habitats have greater need to adjust timing of breeding to rising spring temperatures, because of the strong seasonality in their food. Such between‐habitat differences can have important consequences for population dynamics and should be taken into account in studies on phenotypic plasticity and adaptation to climate change.
Sowing the seeds of algebraic generalization: designing epistemic affordances for an intelligent microworld
Authors: Mavrikis M. , Noss R. , Hoyles C. , Geraniou E. 
Published: February 2012

AbstractThis paper describes the design of a mathematical microworld to tackle the persistent difficulties that secondary school students have with the idea of algebraic generalization, which is a key stumbling block in secondary‐school mathematics classrooms. Our focus is to characterize algebraic ways of thinking and to design both affordances of the system as well as suitable tasks and pedagogies that provide a substrate of activity and experience for the teaching and learning of algebraic generalizations. Using as reference illustrative cases of 12 to 13‐year‐old students' interaction with the microworld, we demonstrate the strong interplay between epistemology and the design of the microworld and draw conclusions regarding its potential to support the development of algebraic ways of thinking.
Supporting self‐regulated learning in computer‐based learning environments: systematic review of effects of scaffolding in the domain of science education
Authors: Devolder A. , van Braak J. , Tondeur J. 
Published: February 2012

AbstractDespite the widespread assumption that students require scaffolding support for self‐regulated learning (SRL) processes in computer‐based learning environments (CBLEs), there is little clarity as to which types of scaffolds are most effective. This study offers a literature review covering the various scaffolds that support SRL processes in the domain of science education. Effective scaffolds are categorized and discussed according to the different areas and phases of SRL. The results reveal that most studies on scaffolding processes focus on cognition, whereas few focus on the non‐cognitive areas of SRL. In the field of cognition, prompts appear to be the most effective scaffolds, especially for processes during the control phase. This review also shows that studies have paid little attention to scaffold designs, learner characteristics, or various task characteristics, despite the fact that these variables have been found to have a significant influence. We conclude with the implications of our results on future design and research in the field of SRL using CBLEs.
Diversification of egg‐deposition behaviours and the evolution of male parental care in darters (Teleostei: Percidae: Etheostomatinae)
Authors: KELLY N. B. , NEAR T. J. , ALONZO S. H. 
Published: February 2012

AbstractMale‐only care is the most frequent parental care behaviour in teleost fishes, but little is known about its evolutionary origins and patterns of diversity in species‐rich lineages. Darters are a clade of North American freshwater fishes that contain both nonparental care species and species with male‐only care. In darters, paternal care takes the form of egg‐guarding and other egg‐tending behaviours that are dependent on the female mode of egg deposition. Male care has been hypothesized to evolve independently in darters at least three times, and it has been thought to be irreversible. We investigated the diversification of egg‐deposition behaviours and the evolution of complex male care using published descriptions of darter reproductive behaviours and a multilocus molecular phylogeny that included all 146 species for which reproductive behaviours are known. We find support for two origins of male‐only care behaviour. One origin of paternal care occurred relatively early in the radiation of Etheostoma and is characteristic of a recently discovered clade, Goneaperca. The other origin of male‐only care occurred much more recently in a derived clade of Nothonotus. Our analyses of character diversification demonstrate reversals from care to noncare and multiple transitions between egg‐deposition behaviours that are not associated with parental care.
Accuracies of estimated breeding values from ordinary genetic evaluations do not reflect the correlation between true and estimated breeding values in selected populations
Authors: Bijma P. 
Published: February 2012

SummaryThe accuracy of estimated breeding values (EBVs) is an important parameter in livestock genetic improvement. It is used to calculate response to selection and to express the credibility of individual EBVs. Although it is well‐known that selection reduces accuracy, this effect is not well‐studied and accuracies from genetic evaluations are not adjusted for selection. This work investigates the effect of selection on accuracy of EBVs estimated using best linear unbiased predictors. Results show that accuracies in a selected population may be considerably smaller than the ordinary accuracy from genetic evaluation. Accuracy of the parent average is dramatically reduced by selection, up to a factor of three. Expressions for equilibrium accuracies in selected populations are presented and depend only on the unselected accuracy and the intensity of selection. Thus, schemes with the same unselected accuracy and intensity of selection also have the same equilibrium accuracy and response to selection. At the same unselected accuracy, therefore, schemes based on between‐family information do not show greater reduction in response and accuracy because of the Bulmer effect. An example shows that benefit of genomic selection may be underestimated when the effect of selection on accuracy is ignored. Finally, this work argues that the SE of an EBV and the correlation between true and EBVs are different things, and that accuracies should not be adjusted for selection when they primarily serve to indicate the SEs of EBVs.
Occurrence of mycotoxins in Polish animal feed in years 2006–2009
Authors: Grajewski J. , Błajet‐Kosicka A. , Twarużek M. , Kosicki R. 
Published: February 2012

SummaryWe performed a 4‐year survey (2006–2009, 1255 samples) of fungal secondary metabolites in feed material (cereal and corn grains) and feedstuffs (silages, mixed feeds). Five major mycotoxin groups were studied, including aflatoxins (AF), ochratoxin A (OTA), trichothecenes [deoxynivalenol (DON), nivalenol (NIV), T‐2 toxin, HT‐2 toxin], zearalenone (ZEA) and fumonisins (FUM). The metabolites were identified using HPLC methods with fluorescent, UV and MS/MS detection. Both immunoaffinity and SPE columns were used for sample preparation. In eleven samples, the concentration of several mycotoxins exceeded the recommended guidelines for feedstuffs. DON was detected at the highest concentration in the majority of analysed samples (cereal grains, silages and mixed feeds, maximum values ranged from 409 to 14 470 ng/g). Corn grains also contained other Fusarium toxins (FUM) at maximum levels ranging from 435 to 9409 ng/g. The highest averagepositive concentration of the other trichothecenes (NIV, T‐2 and HT‐2 toxins) was <5.0–139 ng/g. ZEA was found at the highest concentration in corn grains and silages (maximum values ranging from 292 to 603 ng/g and 116 to 1150 ng/g, respectively). The highest averagepositive concentration and the maximum level of OTA were detected in cereal grains (33.0 ng/g in 2009 and 760 ng/g in 2007, respectively). Less than 7% of the 557 samples were contaminated with AF at low levels (maximum of 0.61 ng/g). Our results support the need for further monitoring of mycotoxins in Polish feedstuffs and their components.
Definition of glaucoma: clinical and experimental concepts
Authors: Casson Robert J , Chidlow Glyn , Wood John PM , Crowston Jonathan G , Goldberg Ivan 
Published: February 2012

AbstractGlaucoma is a term describing a group of ocular disorders with multi‐factorial etiology united by a clinically characteristic intraocular pressure‐associated optic neuropathy. It is not a single entity and is sometimes referred to in the plural as the glaucomas. All forms are potentially progressive and can lead to blindness. The diverse conditions that comprise glaucoma are united by a clinically characteristic optic neuropathy: glaucomatous optic neuropathy (GON). Evidence suggests that the primary site of neurological injury is at the optic nerve head. This fact enables the conditions to be grouped, irrespective of the causal mechanism(s). The term experimental glaucoma implies model resemblance to the human condition. We propose that ‘experimental glaucoma’ be restricted to animal models with demonstrable features of GON and/or evidence of a primary axonopathy at the optic nerve head. A fundamental inadequacy in this framework is any reference to the pathogenesis of GON, which remains unclear.
New HIV diagnosis after occupational exposure screening: the importance of reporting needlestick injuries
Authors: Upjohn L. M. , Stuart R. L. , Korman T. M. , Woolley I. J. 
Published: February 2012

AbstractWe describe three new diagnosis of HIV infection as a direct result of testing following occupational exposures (NSIs) in a low‐prevalence setting. In each case the finding was unexpected. Our series provides a reminder of the importance of prompt reporting of NSIs by healthcare workers, access to rapid HIV testing and post‐exposure prophylaxis with antiretrovirals to prevent transmission.
Adenocarcinoma metastatic to the uterine cervix: A case series
Authors: Pérez‐Montiel Delia , Serrano‐Olvera Alberto , Salazar Luz Calderón , Cetina‐Pérez Lucely , Candelaria Myrna , Coronel Jaime , Herrera Montalvo Luis Alonso , Cantú de León David 
Published: February 2012

AbstractAims:  The objectives of this report are, first, to describe the clinical behavior of cases of carcinoma metastatic to the uterine cervix treated at our institution in order to carry out a systematic review to establish the behavioral patterns of the most frequent metastases to the cervix and, second, to generate guidelines for their diagnosis and treatment.Methods:  At the National Institute of Cancer of Mexico (INCan), we performed a review of the clinical files with a diagnosis of malignant neoplasm metastatic to the uterine cervix between 1990 and 2009. For a systematic review, we conducted a PubMed search between the years 1970 and 2009 of case reports and series of cases of patients with metastatic gastric, breast, ovarian and colorectal cancer. We analyzed each report individually and extracted the patients' clinical data from our cases and reports, including the primary tumor, cervical metastases and survival rates.Results:  There were 10 cases of tumors metastatic to the uterine cervix. Metastasis was documented in one‐half of the patients during follow up, with two of these cases having the cervix as the only site. We included the following reports in the systematic review: 13 reports of gastric‐associated cancer, 30 related to breast cancer, nine with ovarian‐associated cancer and 10 related to colorectal cancer.Conclusions:  Metastatic cervical activity is an infrequent event. The prognosis of survival is poor in the presence of gastric or ovarian cancer and cervical metastases.
Heterogeneity in sex differences in the metabolic syndrome in Dutch white, Surinamese African and South Asian populations
Authors: Agyemang C. , van Valkengoed I. G. , van den Born B. J. , Bhopal R. , Stronks K. 
Published: February 2012

Diabet. Med. 29, 1159‐1164 (2012)AbstractAim  To determine whether sex differences in the prevalence of the metabolic syndrome and its components differ among different ethnic groups.Methods  A random sample of non‐institutionalized adults aged 35–60 years in Amsterdam, the Netherlands (white Dutch men n = 242, women n = 244; African‐Surinamese men n = 193, women n = 399, Hindustani‐Surinamese men n = 149, women n = 186). The metabolic syndrome was defined according to the International Diabetes Federation criteria.Results  In all ethnic groups, the prevalence of central obesity and reduced HDL cholesterol were higher in women than in men, but the prevalence of elevated blood pressure, fasting glucose and triglycerides were lower in women than in men. However, the magnitude of the differences varied. The sex differences in the prevalence of central obesity and reduced HDL cholesterol were particularly larger in ethnic minority groups, especially in African‐Surinamese than in white Dutch. After adjustment for education, smoking, alcohol intake and physical activity, the prevalence of the metabolic syndrome was lower in white Dutch women than in white Dutch men (adjusted prevalence ratio 0.70, 95% CI 0.52–0.94). By contrast, the prevalence of the metabolic syndrome was higher in African‐Surinamese women than in African‐Surinamese men (adjusted prevalence ratio 1.56, 95% CI 1.12–2.18). Among Hindustani‐Surinamese, men and women had a similar prevalence of the metabolic syndrome (adjusted prevalence ratio 1.00, 95% CI 0.76–1.31).Conclusions  Our findings suggest different patterns in sex differences in the metabolic syndrome among the ethnic groups. The relatively high prevalence of central obesity in African‐Surinamese women may underlie their higher prevalence of the metabolic syndrome. Strategies to improve metabolic profiles among African‐Surinamese and white Dutch people need to take sex differences into account.
Commercial discourses, gentrification and citizens’ protest: The linguistic landscape of Prenzlauer Berg, Berlin1
Authors: Papen Uta 
Published: February 2012

Since reunification in 1990, Prenzlauer Berg, located in the former East Berlin, has turned from a cheap and neglected area into a popular middle‐class neighbourhood. The area's new character is reflected in its linguistic landscape. These days the signs of posh shops and trendy bars adorn its streets. But alternative views are noticeable too. Graffiti is present even on the most expensively refurbished buildings and residents put up slogans to protest against their flats being refurbished and sold to new owners. This case study of the changing graphic environment of Prenzlauer Berg shows that, despite the strong influence of commercial discourses, the public space remains an area of contestation between civil society, private businesses and the state. The particular approach to linguistic landscape I developed combines textual and visual analysis with interviews with sign producers. This has enabled me to show how the linguistic landscape both reflects as well as shapes social change and urban development in Berlin since reunification.Seit der Wende ist der Prenzlauer Berg, zu DDR Zeiten vernachlässigt und heruntergekommen, zu einem der beliebtesten Stadtteile des neuen Berlins geworden. Der neue Charakter des Kiez, sichtbar an seinen renovierten Häusern und steigenden Mietpreisen, lässt sich auch anhand seiner sprachlichen Landschaft (linguistic landscape) erkennen. Heutzutage bestimmen die aufwendig gestalteten Schilder teurer Geschäfter und schicker Bars Prenzlauer Bergs Strassenbild. Es gibt aber auch andere Stimmen. Bewohner von Häusern, die an Investoren verkauft wurden und denen nun gesteigerte Mieten drohen, protestieren mit Plakaten gegen die Politik der Ankäufer. Fast keine der neu gestrichenen Fassaden ist frei von Graffiti und überall findet man Poster, die zu Demonstrationen und Unterschriftenaktionen aufforden. Ausgehend von Fotografien und Interviews mit den Autoren von Schildern, Plakaten und Transparenten zeigt der vorliegende Artikel, dass der öffentliche Raum – die Strasse – trotz der Dominanz kommerziellen Diskurse, ein Bereich bleibt, in dem Staat, private Inverstoren und bürgerliche Gesellschaft aufeinander treffen und ihre – oftmals im Konflikt zueinander stehenden – Meinungen zum Ausdruck bringen. [German]
The Identification of a Mixture of First‐Order Binary Markov Chains*
Authors: Browning Martin , Carro Jesus M. 
Published: February 2012

AbstractLet S be the number of components in a finite discrete mixing distribution. We prove that the number of waves of panel being greater than or equal to 2S is a sufficient condition for global identification of a dynamic binary choice model in which all the parameters are heterogeneous. This model results in a mixture of S binary first‐order Markov Chains.
Geobiological constraints on Earth system sensitivity to CO2 during the Cretaceous and Cenozoic
Authors: ROYER D. L. , PAGANI M. , BEERLING D. J. 
Published: February 2012

AbstractEarth system climate sensitivity (ESS) is the long‐term (>103 year) response of global surface temperature to doubled CO2 that integrates fast and slow climate feedbacks. ESS has energy policy implications because global temperatures are not expected to decline appreciably for at least 103 year, even if anthropogenic greenhouse gas emissions drop to zero. We report provisional ESS estimates of 3 °C or higher for some of the Cretaceous and Cenozoic based on paleo‐reconstructions of CO2 and temperature. These estimates are generally higher than climate sensitivities simulated from global climate models for the same ancient periods (approximately 3 °C). Climate models probably do not capture the full suite of positive climate feedbacks that amplify global temperatures during some globally warm periods, as well as other characteristic features of warm climates such as low meridional temperature gradients. These absent feedbacks may be related to clouds, trace greenhouse gases (GHGs), seasonal snow cover, and/or vegetation, especially in polar regions. Better characterization and quantification of these feedbacks is a priority given the current accumulation of atmospheric GHGs.
Lifting the lid on GPCRs: the role of extracellular loops
Authors: Wheatley M , Wootten D , Conner MT , Simms J , Kendrick R , Logan RT , Poyner DR , Barwell J 
Published: February 2012

GPCRs exhibit a common architecture of seven transmembrane helices (TMs) linked by intracellular loops and extracellular loops (ECLs). Given their peripheral location to the site of G‐protein interaction, it might be assumed that ECL segments merely link the important TMs within the helical bundle of the receptor. However, compelling evidence has emerged in recent years revealing a critical role for ECLs in many fundamental aspects of GPCR function, which supported by recent GPCR crystal structures has provided mechanistic insights. This review will present current understanding of the key roles of ECLs in ligand binding, activation and regulation of both family A and family B GPCRs.LINKED ARTICLES This article is part of a themed section on the Molecular Pharmacology of G Protein‐Coupled Receptors (GPCRs). To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue‐6. To view the 2010 themed section on the same topic visit http://onlinelibrary.wiley.com/doi/10.1111/bph.2010.159.issue‐5/issuetoc
Ketamine‐induced ventricular structural, sympathetic and electrophysiological remodelling: pathological consequences and protective effects of metoprolol
Authors: Li Y , Shi J , Yang BF , Liu L , Han CL , Li WM , Dong DL , Pan ZW , Liu GZ , Geng JQ , Sheng L , Tan XY , Sun DH , Gong ZH , Gong YT 
Published: February 2012

BACKGROUND AND PURPOSE Growing evidence suggests that long‐term abuse of ketamine does harm the heart and increases the risk of sudden death. The present study was performed to explore the cardiotoxicity of ketamine and the protective effects of metoprolol.EXPERIMENTAL APPROACH Rats and rabbits were divided into control, ketamine, metoprolol alone and ketamine plus metoprolol groups. Ketamine (40 mg·kg−1·day−1, i.p.) and metoprolol (20 mg·kg−1·day−1, p.o.) were administered continuously for 12 weeks in rats and 8 weeks in rabbits. Cardiac function, electrophysiological disturbances, cardiac collagen, cardiomyocte apoptosis and the remodelling‐related proteins were evaluated.KEY RESULTS Rabbits treated with ketamine showed decreased left ventricular ejection fraction, slowed ventricular conduction velocity and increased susceptibility to ventricular arrhythmia. Metoprolol prevented these pathophysiological alterations. In ketamine‐treated rats, cardiac collagen volume fraction and apoptotic cell number were higher than those of control animals; these effects were prevented by co‐administration of metoprolol. Consistently, the expressions of poly (ADP‐ribose) polymerases‐1, apoptosis‐inducing factor and NF‐κB‐light‐chain‐enhancer of activated B cells were all increased after ketamine treatment and sharply reduced after metoprolol administration. Moreover, ketamine enhanced sympathetic sprouting, manifested as increased growth‐associated protein 43 and tyrosine TH expression. These effects of ketamine were prevented by metoprolol.CONCLUSIONS AND IMPLICATIONS Chronic treatment with ketamine caused significant ventricular myocardial apoptosis, fibrosis and sympathetic sprouting, which altered the electrophysiological properties of the heart and increased its susceptibility to malignant arrhythmia that may lead to sudden cardiac death. Metoprolol prevented the cardiotoxicity of ketamine, indicating a promising new therapeutic strategy.