bluuebunny/crossref_metadata_2025_split huggingface dataset:
AUC: a misleading measure of the performance of predictive distribution models
Authors: Lobo Jorge M. , Jiménez‐Valverde Alberto , Real Raimundo 
Published: October 2007

ABSTRACTThe area under the receiver operating characteristic (ROC) curve, known as the AUC, is currently considered to be the standard method to assess the accuracy of predictive distribution models. It avoids the supposed subjectivity in the threshold selection process, when continuous probability derived scores are converted to a binary presence–absence variable, by summarizing overall model performance over all possible thresholds. In this manuscript we review some of the features of this measure and bring into question its reliability as a comparative measure of accuracy between model results. We do not recommend using AUC for five reasons: (1) it ignores the predicted probability values and the goodness‐of‐fit of the model; (2) it summarises the test performance over regions of the ROC space in which one would rarely operate; (3) it weights omission and commission errors equally; (4) it does not give information about the spatial distribution of model errors; and, most importantly, (5) the total extent to which models are carried out highly influences the rate of well‐predicted absences and the AUC scores.
Woody cover in African savannas: the role of resources, fire and herbivory
Authors: Sankaran Mahesh , Ratnam Jayashree , Hanan Niall 
Published: October 2007

ABSTRACTAim  To determine the functional relationships between, and the relative importance of, different driver variables (mean annual precipitation, soil properties, fire and herbivory) in regulating woody plant cover across broad environmental gradients in African savannas.Location  Savanna grasslands of East, West and Southern Africa.Methods  The dependence of woody cover on mean annual precipitation (MAP), soil properties (texture, nitrogen mineralization potential and total phosphorus), fire regimes, and herbivory (grazer, browser + mixed feeder, and elephant biomass) was determined for 161 savanna sites across Africa using stochastic gradient boosting, a refinement of the regression tree analysis technique.Results  All variables were significant predictors of woody cover, collectively explaining 71% of the variance in our data set. However, their relative importance as regulators of woody cover varied. MAP was the most important predictor, followed by fire return periods, soil characteristics and herbivory regimes. Woody cover showed a strong positive dependence on MAP between 200 and 700 mm, but no dependence on MAP above this threshold when the effects of other predictors were accounted for. Fires served to reduce woody cover below rainfall‐determined levels. Woody cover showed a complex, non‐linear relationship with total soil phosphorus, and was negatively correlated with clay content. There was a strong negative dependence of woody cover on soil nitrogen (N) availability, suggesting that increased N‐deposition may cause shifts in savannas towards more grassy states. Elephants, mixed feeders and browsers had negative effects on woody cover. Grazers, on the other hand, depressed woody cover at low biomass, but favoured woody vegetation when their biomass exceeded a certain threshold.Main conclusions  Our results indicate complex and contrasting relationships between woody cover, rainfall, soil properties and disturbance regimes in savannas, and suggest that future environmental changes such as altered precipitation regimes, N‐enrichment and elevated levels of CO2 are likely to have opposing, and potentially interacting, influences on the tree–grass balance in savannas.
THE ETHICS OF CESAREAN SECTION ON MATERNAL REQUEST: A FEMINIST CRITIQUE OF THE AMERICAN COLLEGE OF OBSTETRICIANS AND GYNECOLOGISTS' POSITION ON PATIENT‐CHOICE SURGERY
Authors: BERGERON VERONIQUE 
Published: October 2007

ABSTRACTIn recent years, the medical establishment has been speaking in favor of women's autonomy in childbirth by advocating cesarean delivery on maternal request (CDMR). This paper offers to look at the ethical dimension of CDMR through a feminist critique of the medicalization of childbirth and its influence on present‐day medical ethics. I claim that the medicalization of childbirth reflects a sexist bias with regard to conceptions of the body and needs to be used with caution when applied to women's reproductive health. I then use this perspective to critically analyze the position of the American College of Obstetricians and Gynecologists (ACOG) on the ethics of decision‐making in patient‐choice surgery. I claim that informed consent cannot be meaningfully exercised unless women are made aware of the sexist underpinnings of the medical model of childbirth and its influence on the ethical reasoning of the American College of Obstetricians and Gynecologists. I also express concern about the effects of normalizing patient‐choice cesarean sections on the choices available to pregnant women using as examples the institutional rules on mandatory cesarean sections for women with a previous cesarean delivery or breech presentation. I conclude with a call for more research into the real cost of convenience in CDMR, particularly as our increasingly strained publicly funded healthcare system would greatly benefit from the de‐medicalization of normal body functions rather than an increased dependence on costly surgical technology.
GENDER‐BASED DISPARITIES EAST/WEST: RETHINKING THE BURDEN OF CARE IN THE UNITED STATES AND TAIWAN
Authors: TONG ROSEMARIE 
Published: October 2007

ABSTRACTWhen feminist bioethicists express concerns about health‐related gender disparities, they raise considerations about justice and gender that traditional bioethicists have either not raised or raised somewhat weakly. In this article, I first provide a feminist analysis of long‐term healthcare by and for women in the United States and women in Taiwan. Next, I make the case that, on average, elderly US and Taiwanese women fare less well in long‐term care contexts than do elderly US and Taiwanese men. Finally, I explore some suggested practical remedies to reduce gender disparities in long‐term care contexts.
IS SEX‐SELECTIVE ABORTION MORALLY JUSTIFIED AND SHOULD IT BE PROHIBITED?
Authors: ROGERS WENDY , BALLANTYNE ANGELA , DRAPER HEATHER 
Published: October 2007

ABSTRACTIn this paper we argue that sex‐selective abortion (SSA) cannot be morally justified and that it should be prohibited. We present two main arguments against SSA. First, we present reasons why the decision for a woman to seek SSA in cultures with strong son‐preference cannot be regarded as autonomous on either a narrow or a broad account of autonomy. Second, we identify serious harms associated with SSA including perpetuation of discrimination against women, disruption to social and familial networks, and increased violence against women. For these reasons, SSA should be prohibited by law, and such laws should be enforced. Finally, we describe additional strategies for decreasing son‐preference. Some of these strategies rely upon highlighting the disadvantages of women becoming scarce, such as lack of brides and daughters‐in‐law to care for elderly parents. We should, however, be cautious not to perpetuate the view that the purpose of women is to be the consorts for, and carers of, men, and the providers of children. Arguments against SSA should be located within a concerted effort to ensure greater, deeper social and cultural equality between the sexes.
The Advent of the Secret Ballot in Britain and France, 1789–1914: From Public Assembly to Private Compartment
Authors: CROOK MALCOLM , CROOK TOM 
Published: October 2007

AbstractThese days the secret ballot is taken for granted and it is often seen as the natural complement of universal, democratic suffrage. Its emergence, however, was just as contested and varied as the franchise and raised similar issues concerning the nature and practice of citizenship. This article focuses on the emergence of the secret ballot in Britain and France, two countries with a long history of parliamentary and local elections. In Britain, the secret ballot was introduced in 1872, while in France, which introduced universal male suffrage in 1848, it was as late as 1913 before envelope and polling booth rendered the vote completely secure. This study documents the varied polling practices employed in both countries prior to the onset of the secret ballot. It also highlights the contentious nature of polling reform. For some, the secret ballot was regarded as a means of safeguarding electoral independence and eliminating corruption. Others, including radicals, argued quite the opposite: that secret voting was an affront to honourable, public‐spirited citizenship. In the end, full secrecy was achieved as part of the broader process of domesticating and disciplining the exercise of a mass franchise.
John T. McNaughton and Vietnam: The Early Years as Assistant Secretary of Defense, 1964–1965
Authors: HARRISON BENJAMIN T. , MOSHER CHRISTOPHER L. 
Published: October 2007

AbstractJohn T. McNaughton is one of the least understood of the major American officials involved in formulating US policy towards the Vietnam War. This article uses a newly discovered journal by McNaughton as well as his private papers to examine the reasons for his opposition to the Vietnam War and to suggest that his perceived image as a ‘hawk’ is inaccurate.
‘King of the Sea’: The Prince of Wales and the Stuart Monarchy, 1648–1649
Authors: KELSEY SEAN 
Published: October 2007

AbstractFrom their outset, the prince of Wales played a politically and symbolically significant part in the English civil wars. But from mid‐1646, with Charles I in the hands of his enemies, primary responsibility for the military and diplomatic aspirations of the House of Stuart devolved almost entirely upon the king's eldest son. Indeed, this essential fact was central to the king's own strategic thinking because he had persuaded himself that his opponents must seek an accommodation with him as long as his successor was at large. The threat posed by the prince became violent reality in 1648 when he commissioned a string of mutinies and rebellions across England and Wales and briefly reasserted royal dominion of the seas. Although his martial and maritime escapades came to nothing, they nevertheless gave the prince his first opportunity to wield the instruments of sovereign power in the exercise of an authority independent of his father's. The second civil war also sharpened the contrast between the prince's freedom of action and the king's hapless captivity. The fortunes of the Stuart monarchy had hit rock bottom, but in the eyes of at least some royalists, an obvious solution had also begun to suggest itself.
Limits of Diplomatic Influence: Brazil versus Britain and the United States, 1886–1894
Authors: SMITH JOSEPH 
Published: October 2007

AbstractThis article uses events in Brazil at the close of the nineteenth century as a case study to investigate how nations on the ‘periphery’ contested the efforts of the great powers to control their behaviour. The article concentrates on Brazil's diplomatic relations with Britain and the United States. It examines the failure of the foreign office to negotiate a commercial treaty to match the reciprocity arrangement concluded between Brazil and the United States in 1891. The set‐back is seen as a reflection of the limits of Britain's diplomatic influence and ability to halt the rising economic influence of the United States, but it also illustrates Brazil's success in pursuing an independent foreign economic policy. This is further illustrated by the Brazilian Naval Revolt (1893–4) during which the representatives of the foreign powers have been usually depicted as exercising a superior role in directing events. This article uses evidence from Brazilian diplomatic archives to argue that the most significant factor in determining the outcome of the revolt was the combination of firmness and skilful diplomacy shown by the Brazilian government of Floriano Peixoto rather than the activities of the foreign powers, including Britain and the United States.
Early stress and chronic methylphenidate cross‐sensitize dopaminergic responses in the adolescent medial prefrontal cortex and nucleus accumbens
Authors: Jezierski Grzegorz , Zehle Stefanie , Bock Joerg , Braun Katharina , Gruss Michael 
Published: October 2007

AbstractMethylphenidate (MP) is widely used to treat attention deficit/hyperactivity disorder in children. However, basic research has been mainly focused on MP treatment in adult, behaviorally normal rodents. Here we analyzed MP‐evoked changes of dopamine (DA) release in the limbic system of juvenile rodents with hyperactive and attention deficit‐like symptoms. Using dual probe in vivo microdialysis, DA levels were quantified in the medial prefrontal cortex and nucleus accumbens of juvenile and adolescent degus (Octodon degus). Acute stress‐ and acute MP‐evoked dopaminergic responses in normal juvenile and adolescent animals were compared with (i) animals showing symptoms of hyperactivity and attention deficits induced by early life stress, i.e. repeated parental separation during the first 3 weeks of life, and (ii) animals chronically treated with MP during pre‐adolescence. Our main results revealed that (i) early life stress and (ii) chronic MP treatment during pre‐adolescence cross‐sensitize limbic dopaminergic functions in adolescent animals. Furthermore, we demonstrated a unique pattern of acute MP‐evoked DA release in the juvenile compared with the adolescent medial prefrontal cortex and nucleus accumbens. Our findings that the functional maturation of dopaminergic limbic function is significantly altered by early life experience, i.e. repeated parental separation and chronic MP treatment, allow novel insights into the etiology of attention deficit/hyperactivity disorder and into the long‐term consequences of MP treatment on brain development.
Adenosine A2A receptors are required for normal BDNF levels and BDNF‐induced potentiation of synaptic transmission in the mouse hippocampus
Authors: Tebano M. T. , Martire A. , Potenza R. L. , Grò C. , Pepponi R. , Armida M. , Domenici M. R. , Schwarzschild M. A. , Chen J. F. , Popoli P. 
Published: October 2007

AbstractBrain‐derived neurotrophic factor (BDNF), a member of neurotrophin family, enhances synaptic transmission and regulates neuronal proliferation and survival. Both BDNF and its tyrosine kinase receptors (TrkB) are highly expressed in the hippocampus, where an interaction with adenosine A2A receptors (A2ARs) has been recently reported. In the present paper, we evaluated the role of A2ARs in mediating functional effects of BDNF in hippocampus using A2AR knock‐out (KO) mice. In hippocampal slices from WT mice, application of BDNF (10 ng/mL) increased the slope of excitatory post‐synaptic field potentials (fEPSPs), an index of synaptic facilitation. This increase of fEPSP slope was abolished by the selective A2A antagonist ZM 241385. Similarly, genetic deletion of the A2ARs abolished BDNF‐induced increase of the fEPSP slope in slices from A2AR KO mice The reduced functional ability of BDNF in A2AR KO mice was correlated with the reduction in hippocampal BDNF levels. In agreement, the pharmacological blockade of A2Rs by systemic ZM 241385 significantly reduced BDNF levels in the hippocampus of normal mice. These results indicate that the tonic activation of A2ARs is required for BDNF‐induced potentiation of synaptic transmission and for sustaining a normal BDNF tone in the hippocampus.
Differential regulation of the NMDA receptor by acute and sub‐chronic phencyclidine administration in the developing rat
Authors: Anastasio Noelle C. , Johnson Kenneth M. 
Published: October 2007

AbstractNeurodegeneration induced by the NMDA receptor antagonist, phencyclidine (PCP), has been used to model the pathogenesis of schizophrenia in the developing rat. Acute and sub‐chronic administration of PCP in perinatal rats results in different patterns of neurodegeneration. The potential role of an alteration in the membrane expression of NMDA receptors in PCP‐induced degeneration is unknown. Acute PCP treatment on postnatal day 7 increased membrane levels of both NMDA receptor subunit 1 (NR1) and NMDA receptor subunit 2B (NR2B) proteins in the frontal cortex; conversely, NR1 and NR2B protein levels in the endoplasmic reticulum fraction were decreased. Acute PCP administration also resulted in increased membrane cortical protein levels of post‐synaptic density‐95, as well as the activation of calpain, which paralleled the observed increase in membrane expression of NR1 and NR2B. Further, administration of the calpain inhibitor, MDL28170, prevented PCP‐induced up‐regulation of NR1 and NR2B. On the other hand, sub‐chronic PCP treatment on postnatal days 7, 9 and 11 caused an increase in NR1 and NR2A expression, which was accompanied by an increase in both NR1 and NR2A in the endoplasmic reticulum fraction. Sub‐chronic PCP administration did not alter levels of post‐synaptic density‐95 and had no effect on activation of calpain. These data suggest that increased trafficking accounts for up‐regulation of cortical NR1/NR2B subunits following acute PCP administration, while increased protein synthesis likely accounts for the increased expression of NR1/NR2A following sub‐chronic PCP treatment of the developing rat. These results are discussed in the context of the differential neurodegeneration caused by acute and subchronic PCP administration in the developing rat brain.
Specificity proteins Sp1 and Sp3 interact with the rat GTP Cyclohydrolase I proximal promoter to regulate transcription
Authors: Chandran Nitya Sarath , Vunnava Prashanthi , Wu Yanning , Kapatos Gregory 
Published: October 2007

AbstractThe role of the proximal promoter GC‐box in regulating basal and cAMP‐dependent GTP Cyclohydrolase I gene transcription was investigated using a variety of cell lines and techniques. These studies show that the GC‐box is composed of a triad of cis‐elements that in vitro bind specificity proteins Sp1 and Sp3. Sp1 and Sp3 were found associated with the native proximal promoter in PC12 cells but were not recruited to the promoter during cAMP‐dependent transcription. Studies using Drosophila SL2 cells showed that Sp3 occupies two sites within the GC‐box and enhances transcription when acting alone and synergistically when combined with nuclear factor‐Y (NF‐Y) and CCAAT/Enhancer‐Binding Protein (C/EBP)β, cognate binding proteins for the adjacent cAMP response element (CRE) and CCAAT‐box cAMP response elements. In contrast, Sp1 bound only one site within the GC‐box and did not enhance transcription unless combined with NF‐Y and C/EBPβ. Studies in SL2 cells also showed that Sp1 and Sp3 do not co‐occupy the GC‐box, and accordingly Sp1 competes for Sp3 binding to repress Sp3‐dependent transcription. In PC12 cells, complete mutation of the GC‐box reduced basal but not cAMP‐dependent transcription, resulting in an overall increase in the cAMP response and demonstrating that formation of this enhanceosome does not require Sp1 or Sp3. Experiments in which the GC‐box was replaced with a Gal4 element and the promoter challenged with Gal4 fusion proteins support this conclusion and a role for Sp3 in maintaining high levels of basal transcription in PC12 cells. Equivalent amounts of Sp1 and Sp3 were found associated with the native proximal promoter in PC12 and Rat2 cells, which differ 10‐fold in basal transcription. Similar levels of methylation of CpG dinucleotides located within the GC‐box were also observed in these two cells lines. These results suggest that Sp1 and Sp3 bound to the GC‐box might help to preserve an open chromatin configuration at the proximal promoter in cells which constitutively express low levels of GTP Cyclohydrolase I.
The glucocorticoid receptor is a co‐regulator of the orphan nuclear receptor Nurr1
Authors: Carpentier Rodolphe , Sacchetti Paola , Ségard Pascaline , Staels Bart , Lefebvre Philippe 
Published: October 2007

AbstractNurr1 (NR4A2) is an atypical nuclear receptor (NR) because of its inability to bind a ligand and to activate transcription following canonical NR rules. An affinity chromatography‐based screen identified the glucocorticoid receptor (GR) as an interactant of Nurr1. The co‐localization of these two NRs in the hippocampus and the substantia nigra, as well as their involvement in similar neurological processes led us to investigate the functional consequences of such a physical interaction. GR interfered with Nurr1 transcriptional activity, and Nurr1 association to GR confers glucocorticoid regulation to this orphan receptor. The N‐terminal domain of Nurr1 interacts directly with GR, whereas several domains of GR can associate to Nurr1. The GR‐mediated increase in Nurr1 transcriptional activity requires the N‐terminal domain of GR, but not a functional DNA binding domain. Finally, SMRT and SRC2, two co‐regulators of GR, modulated the transcriptional activity of the Nurr1‐GR complex, but not that of Nurr1 alone. Our results therefore establish GR as a transcriptional regulator of Nurr1, and open new opportunities in the pharmacological regulation of Nurr1 by glucocorticoids in the CNS.
Transition metal abundances in microbial carbonate: a pilot study based onin situLA‐ICP‐MS analysis
Authors: KAMBER BALZ S. , WEBB GREGORY E. 
Published: October 2007

ABSTRACTThe ability to recognize the former existence of microbes as well as the biological origin of marine precipitates, such as putative microbialites, is crucial for understanding the development and history of early life on Earth. Increasingly, such rocks hold keys to understanding the geochemical evolution of the oceans and linked Earth systems. Vital trace elements previously have received relatively little attention as clues to the origin of carbonate rocks, and low abundance transition elements in particular, have been difficult to analyse in carbonate matrices for technical reasons. We have used laser ablation–inductively coupled plasma–mass spectroscopy for thein situmeasurement of a broad suite of vital transition metals in Late Devonian reefal limestones that contain coeval microbialite (the calcimicrobeRenalcis), stromatoporoid sponge skeleton, early marine cement, and later diagenetic cement. Comparative experiments conducted in two different ion extraction modes determined theoretical detection limits for transition elements on NIST reference material SRM 612. Analyses of NIST glasses SRM 614 and 616 demonstrate accuracy relative to previously published data. On that basis we have identified significant enrichment of the vital elements V, Sn, Cu and Zn within theRenalcis. The stromatoporoid skeleton by contrast is enriched only in V. Earliest cements, which also may have been mediated to some degree by microbial biofilms on the basis of their morphology, show a much smaller degree of enrichment, and later cements show no enrichment, with the exception of Zn, which is concentrated in the latest cement. Fine particulate carbonate sediments (micrite) show variable metal enrichments that are attributable to varying contributions from detrital siliciclastic contamination.Renalciswas also enriched above the sponge and cements in regards to Mn, Cd, Co, and possibly Cr, but at less robust levels. Molybdenum and Sb were found not to be enriched in theRenalcis, and Ni, although clearly very low in concentration, could not be evaluated owing to its high detection limit. We additionally were able to identify specific zones of contamination inRenalcisencountered as the laser drilled deeper into the carbonate. Time resolved analysis allows exclusion of such contaminants from integration into the results. Successful application of the new technique will now allow us to assess metal uptake in ancient carbonates with implications for interpreting the biogenicity of putative microbialites.