bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of bicarbonate as a pH buffer and electron sink in microbial dechlorination of chloroethenes
Authors: Delgado Anca G , Parameswaran Prathap , Fajardo-Williams Devyn , Halden Rolf U , Krajmalnik-Brown Rosa 
Published: September 2012

AbstractBackgroundBuffering to achieve pH control is crucial for successful trichloroethene (TCE) anaerobic bioremediation. Bicarbonate (HCO3−) is the natural buffer in groundwater and the buffer of choice in the laboratory and at contaminated sites undergoing biological treatment with organohalide respiring microorganisms. However, HCO3−also serves as the electron acceptor for hydrogenotrophic methanogens and hydrogenotrophic homoacetogens, two microbial groups competing with organohalide respirers for hydrogen (H2). We studied the effect of HCO3−as a buffering agent and the effect of HCO3−-consuming reactions in a range of concentrations (2.5-30 mM) with an initial pH of 7.5 in H2-fed TCE reductively dechlorinating communities containingDehalococcoides, hydrogenotrophic methanogens, and hydrogenotrophic homoacetogens.ResultsRate differences in TCE dechlorination were observed as a result of added varying HCO3−concentrations due to H2-fed electrons channeled towards methanogenesis and homoacetogenesis and pH increases (up to 8.7) from biological HCO3−consumption. Significantly faster dechlorination rates were noted at all HCO3−concentrations tested when the pH buffering was improved by providing 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) as an additional buffer. Electron balances and quantitative PCR revealed that methanogenesis was the main electron sink when the initial HCO3−concentrations were 2.5 and 5 mM, while homoacetogenesis was the dominant process and sink when 10 and 30 mM HCO3−were provided initially.ConclusionsOur study reveals that HCO3−is an important variable for bioremediation of chloroethenes as it has a prominent role as an electron acceptor for methanogenesis and homoacetogenesis. It also illustrates the changes in rates and extent of reductive dechlorination resulting from the combined effect of electron donor competition stimulated by HCO3−and the changes in pH exerted by methanogens and homoacetogens.
Social determinants of sex differences in disability among older adults: a multi-country decomposition analysis using the World Health Survey
Authors: Hosseinpoor Ahmad Reza , Stewart Williams Jennifer , Jann Ben , Kowal Paul , Officer Alana , Posarac Aleksandra , Chatterji Somnath 
Published: September 2012

Abstract

Introduction
Women represent a growing proportion of older people and experience increasing disability in their longer lives. Using a universally agreed definition of disability based on the International Classification of Functioning, Disability and Health, this paper examines how, apart from age, social and economic factors contribute to disability differences between older men and women.

Methods
World Health Survey data were analyzed from 57 countries drawn from all income groups defined by the World Bank. The final sample comprises 63638 respondents aged 50 and older (28568 males and 35070 females). Item Response Theory was applied to derive a measure of disability which ensured cross country comparability. Individuals with scores at or above a threshold score were those who experienced significant difficulty in their everyday lives, irrespective of the underlying etiology. The population was then divided into “disabled” vs. “not disabled”. We firstly computed disability prevalence for males and females by socio-demographic factors, secondly used multiple logistic regression to estimate the adjusted effects of each social determinant on disability for males and females, and thirdly used a variant of the Blinder-Oaxaca decomposition technique to partition the measured inequality in disability between males and females into the “explained” part that arises because of differences between males and females in terms of age and social and economic characteristics, and an “unexplained” part attributed to the differential effects of these characteristics.

Results
Prevalence of disability among women compared with men aged 50+ years was 40.1% vs. 23.8%. Lower levels of education and economic status are associated with disability in women and men. Approximately 45% of the sex inequality in disability can be attributed to differences in the distribution of socio-demographic factors. Approximately 55% of the inequality results from differences in the effects of the determinants.

Conclusions
There is an urgent need for data and methodologies that can identify how social, biological and other factors separately contribute to the health decrements facing men and women as they age. This study highlights the need for action to address social structures and institutional practices that impact unfairly on the health of older men and women.
Rice UBC13, a candidate housekeeping gene, is required for K63-linked polyubiquitination and tolerance to DNA damage
Authors: Zang Yuepeng , Wang Qian , Xue Chenyu , Li Mengnan , Wen Rui , Xiao Wei 
Published: September 2012

Abstract
While plant growth and reproduction is dependent on sunlight, UV irradiation from sunlight is one of the major genotoxic stresses that threaten plant survival and genome stability. In addition, many environmental chemicals can also damage the plant genome. In yeast and mammalian cells protection against the above genome instability is provided by an error-free DNA-damage tolerance (DDT) pathway, which is dependent on Ubc13-mediated K63-linked polyubiquitination of the proliferating cell nuclear antigen (PCNA). In this study, we isolated the UBC13 gene from rice and characterized its functions. Expression of OsUBC13 can protect a yeast ubc13 null mutant against spontaneous and environmental DNA damage. Furthermore, OsUbc13 physically interacts with human Ubc13 partners Mms2 and Uev1A, and catalyzes K63 polyubiquitination in vitro. These observations collectively suggest that the K63 polyubiquitination is conserved in rice, and that OsUBC13 may be involved in DDT and other cellular processes. In addition, OsUBC13 is constitutively expressed at a high level even under various stress conditions, suggesting that it is a housekeeping gene.
Fetal Glucocorticoid Synthesis Is Required for Development of Fetal Adrenal Medulla and Hypothalamus Feedback Suppression
Authors: Huang Chen-Che Jeff , Shih Meng-Chun Monica , Hsu Nai-Chi , Chien Yu , Chung Bon-chu 
Published: September 2012

AbstractDuring pregnancy, fetal glucocorticoid is derived from both maternal supply and fetal secretion. We have created mice with a disruption of the Cyp11a1 gene resulting in loss of fetal steroid secretion but preserving the maternal supply. Cyp11a1null embryos have appreciable although lower amounts of circulating corticosterone, the major mouse glucocorticoid, suggesting that transplacental corticosterone is a major source of corticosterone in fetal circulation. These embryos thus provide a means to examine the effect of fetal glucocorticoids. The adrenal in Cyp11a1 null embryos was disorganized with abnormal mitochondria and oil accumulation. The adrenal medullary cells did not express phenylethanolamine N-methyltransferase and synthesized no epinephrine. Cyp11a1 null embryos had decreased diencephalon Hsd11b1, increased diencephalon Crh, and increased pituitary Pomc expression, leading to higher adrenocorticotropin level in the plasma. These data indicate blunted feedback suppression despite reasonable amounts of circulating corticosterone. Thus, the corticosterone synthesized in situ by the fetus is required for negative feedback suppression of the hypothalamus-pituitary-adrenal axis and for catecholamine synthesis in adrenal medulla.
Vitamin D Receptor Activation Induces Peptide YY Transcription in Pancreatic Islets
Authors: Choi Mihwa , Ozeki Jun , Hashizume Masami , Kato Shigeaki , Ishihara Hisamitsu , Makishima Makoto 
Published: September 2012

AbstractPeptide YY (PYY) is a peptide hormone secreted from L cells in the intestine after food intake and regulates appetite and intestinal function. PYY is also expressed in the pancreas, but the mechanisms of regulation of pancreatic PYY expression have not been elucidated. The vitamin D receptor (VDR) is a nuclear receptor for the active form of vitamin D3 and regulates numerous physiological processes. Because VDR is expressed in the pancreas, we investigated the role of pancreatic VDR activation and found that Pyy is a VDR target gene in the mouse pancreas. Treatment of mice with 1α-hydroxyvitamin D3 increased plasma PYY levels. VDR activation increased mRNA and protein expression of PYY in the pancreatic islets of mice and pancreatic endocrine cell lines but did not change intestinal PYY expression. 1α-Hydroxyvitamin D3-dependent induction of pancreatic and plasma PYY was abolished in VDR-null mice. We identified a functional vitamin D-responsive element in the mouse Pyy promoter using chromatin immunoprecipitation assay, EMSA, and luciferase promoter assay. Thus, Pyy is a tissue-specific VDR target gene. The pancreatic VDR-PYY pathway may mediate a regulatory function of vitamin D in the neuroendocrine system.
17β-Estradiol and Progesterone Regulate Expression of β-Amyloid Clearance Factors in Primary Neuron Cultures and Female Rat Brain
Authors: Jayaraman Anusha , Carroll Jenna C. , Morgan Todd E. , Lin Sharon , Zhao Liqin , Arimoto Jason M. , Murphy M. Paul , Beckett Tina L. , Finch Caleb E. , Brinton Roberta Diaz , Pike Christian J. 
Published: September 2012

AbstractThe accumulation of β-amyloid protein (Aβ) is a key risk factor in the development of Alzheimer's disease. The ovarian sex steroid hormones 17β-estradiol (E2) and progesterone (P4) have been shown to regulate Aβ accumulation, although the underlying mechanism(s) remain to be fully elucidated. In this study, we investigate the effects of E2 and P4 treatment on the expression levels of Aβ clearance factors including insulin-degrading enzyme, neprilysin, endothelin-converting enzyme 1 and 2, angiotensin-converting enzyme, and transthyretin, both in primary neuron cultures and female rat brains. Our results show that E2 and P4 affect the expression levels of several Aβ clearance factors in dose- and time-dependent manners. Most notably, expression of insulin-degrading enzyme is significantly increased by both hormones in cultured neurons and in vivo and is inversely associated with the soluble Aβ levels in vivo. These findings further define sex steroid hormone actions involved in regulation of Aβ, a relationship potentially important to therapeutic approaches aimed at reducing risk of Alzheimer's disease.
Ghrelin Receptor Expression and Colocalization with Anterior Pituitary Hormones Using a GHSR-GFP Mouse Line
Authors: Reichenbach Alex , Steyn Frederik J. , Sleeman Mark W. , Andrews Zane B. 
Published: September 2012

Abstract
Ghrelin is the endogenous ligand for the GH secretagogue receptor (GHSR) and robustly stimulates GH release from the anterior pituitary gland. Ghrelin also regulates the secretion of anterior pituitary hormones including TSH, LH, prolactin (PRL), and ACTH. However, the relative contribution of a direct action at the GHSR in the anterior pituitary gland vs. an indirect action at the GHSR in the hypothalamus remains undefined. We used a novel GHSR-enhanced green fluorescent protein (eGFP) reporter mouse to quantify GHSR coexpression with GH, TSH, LH, PRL, and ACTH anterior pituitary cells in males vs. females and in chow-fed or calorie-restricted (CR) mice. GHSR-eGFP-expressing cells were only observed in anterior pituitary. The number of GHSR-eGFP-expressing cells was higher in male compared with females, and CR did not affect the GHSR-eGFP cell number. Double staining revealed 77% of somatotrophs expressed GHSR-eGFP in both males and females. Nineteen percent and 12.6% of corticotrophs, 21% and 9% of lactotrophs, 18% and 19% of gonadotrophs, and 3% and 9% of males and females, respectively, expressed GHSR-eGFP. CR increased the number of TSH cells, but suppressed the number of lactotrophs and gonadotrophs, expressing GHSR-eGFP compared with controls. These studies support a robust stimulatory action of ghrelin via the GHSR on GH secretion and identify a previously unknown sexual dimorphism in the GHSR expression in the anterior pituitary. CR affects GHSR-eGFP expression on lactotrophs, gonadotrophs, and thyrotrophs, which may mediate reproductive function and energy metabolism during periods of negative energy balance. The low to moderate expression of GHSR-eGFP suggests that ghrelin plays a minor direct role on remaining anterior pituitary cells.
The Effect of a Short Sprint on Postexercise Whole-Body Glucose Production and Utilization Rates in Individuals with Type 1 Diabetes Mellitus
Authors: Fahey A. J. , Paramalingam N. , Davey R. J. , Davis E. A. , Jones T. W. , Fournier P. A. 
Published: September 2012

Context:
Recently we showed that a 10-sec maximal sprint effort performed before or after moderate intensity exercise can prevent early hypoglycemia during recovery in individuals with type 1 diabetes mellitus (T1DM). However, the mechanisms underlying this protective effect of sprinting are still unknown.

Objective:
The objective of the study was to test the hypothesis that short duration sprinting increases blood glucose levels via a disproportionate increase in glucose rate of appearance (Ra) relative to glucose rate of disappearance (Rd).

Subjects and Experimental Design:
Eight T1DM participants were subjected to a euglycemic-euinsulinemic clamp and, together with nondiabetic participants, were infused with [6,6-2H]glucose before sprinting for 10 sec and allowed to recover for 2 h.

Results:
In response to sprinting, blood glucose levels increased by 1.2 ± 0.2 mmol/liter (P &lt; 0.05) within 30 min of recovery in T1DM participants and remained stable afterward, whereas glycemia rose by only 0.40 ± 0.05 mmol/liter in the nondiabetic group. During recovery, glucose Ra did not change in both groups (P &gt; 0.05), but glucose Rd in the nondiabetic and diabetic participants fell rapidly after exercise before returning within 30 min to preexercise levels. After sprinting, the levels of plasma epinephrine, norepinephrine, and GH rose transiently in both experimental groups (P &lt; 0.05).

Conclusion:
A sprint as short as 10 sec can increase plasma glucose levels in nondiabetic and T1DM individuals, with this rise resulting from a transient decline in glucose Rd rather than from a disproportionate rise in glucose Ra relative to glucose Rd as reported with intense aerobic exercise.
Magnesium Supplementation Does Not Affect Blood Calcium Level in Treated Hypoparathyroid Patients
Authors: Lubi Maire , Tammiksaar Kaia , Matjus Svetlana , Vasar Eero , Volke Vallo 
Published: September 2012

Context:
Magnesium is involved in the homeostasis of calcium metabolism, and magnesium deficiency may lead to clinically significant hypocalcemia. We have had two cases in our department in which treated hypoparathyroid patients with stable calcium levels developed hypercalcemia in conjunction with supplementary magnesium use. To our knowledge, there has been no prospective study looking at the effect of supplementary magnesium on calcium homeostasis in hypoparathyroid patients.

Objective:
The aim of this pilot study was to evaluate whether magnesium treatment affects plasma calcium levels in hypoparathyroid patients.

Design and Setting:
We conducted a prospective, two-phase, uncontrolled treatment trial at a referral center of endocrine disorders.

Participants:
We enrolled treated (calcium + vitamin D analog) hypoparathyroid patients with normal plasma magnesium levels.

Intervention:
Three weeks of treatment with oral magnesium (350 mg/d) were followed by 2 wk off treatment.

Measures:
We compared the plasma ionized calcium level after 3 wk of treatment to the pretreatment value. Plasma calcium, phosphate, magnesium, and creatinine levels were measured before treatment, after 3 wk on magnesium, and 2 wk after stopping magnesium treatment.

Results:
Ten patients completed the trial. Supplementary treatment with magnesium for 3 wk did not change calcium levels in these patients. Magnesium supplementation induced a small but statistically significant increase in the plasma magnesium level, but levels of phosphate and creatinine remained stable.

Conclusions:
Magnesium supplementation did not influence plasma calcium levels in treated hypoparathyroid patients.
What Fortune Can Do to a Minim
Authors: Zayaruznaya Anna 
Published: September 2012

AbstractAmong the numerous references to music in the writings of poet, composer, and Burgundian chronicler Jean Molinet, none is more puzzling than a passage from his Roman de la rose moralisé (ca. 1500) that describes the misadventures of a note—a minim—fallen victim to Fortune. As it rides her wheel, it becomes a maxima and then a minim again, while its pitch is raised, then lowered. Another passage linking Fortune with transposition and mensural change occurs in Molinet's Petit traictié soubz obscure poetrie. Both stories are exempla divorced from their immediate contexts, raising the possibility that Molinet may have been influenced by specific musical compositions related to Fortune. Aspects of notational usage and cantus-firmus manipulation in the Fortuna desperata masses of Jacob Obrecht and Josquin des Prez make these works—especially the latter—likely influences for Molinet's strange digressions. And Molinet's exempla, insofar as they can help clarify previously misinterpreted aspects of both works, are an important early example of musical hermeneutics. The difficult relationship between Molinet's musical stories and the ostensibly sacred texts from which they digress also offers insight into the devotional functions of secular mass models.
Dancing the Future, Performing the Past: Isadora Duncan and Wagnerism in the American Imagination
Authors: Simonson Mary 
Published: September 2012

AbstractDuring the first two decades of the twentieth century, dancer Isadora Duncan (1877–1927) regularly appeared on concert hall and opera house stages in New York and other American cities. Audiences were taken with her striking persona and nontraditional conception of dance, and impressed by her success in Europe. Duncan's artistic, intellectual, and personal self-association with Richard Wagner—a mythological being in the contemporary American imagination—also captured the attention of many audience members. Duncan danced to excerpts from Tristan und Isolde, Parsifal, and other works while rejecting Wagner's conception of dance; she borrowed language and ideological formulations from his writings while dismissing his aesthetic theories. The American Wagner cult has long been associated with the Gilded Age and conductor Anton Seidl (1850–1898). Isadora Duncan's American performances demonstrate that American Wagnerism persisted well into the twentieth century, albeit in a different form. Conjuring herself as a rebellious disciple of Wagner, Duncan modeled a second generation of American Wagnerism that combined contemporary cultural debates and early modernist aesthetics with strains of Wagner's art and ideologies.
A Novel Approach for Choosing Summary Statistics in Approximate Bayesian Computation
Authors: Aeschbacher Simon , Beaumont Mark A , Futschik Andreas 
Published: September 2012

AbstractThe choice of summary statistics is a crucial step in approximate Bayesian computation (ABC). Since statistics are often not sufficient, this choice involves a trade-off between loss of information and reduction of dimensionality. The latter may increase the efficiency of ABC. Here, we propose an approach for choosing summary statistics based on boosting, a technique from the machine-learning literature. We consider different types of boosting and compare them to partial least-squares regression as an alternative. To mitigate the lack of sufficiency, we also propose an approach for choosing summary statistics locally, in the putative neighborhood of the true parameter value. We study a demographic model motivated by the reintroduction of Alpine ibex (Capra ibex) into the Swiss Alps. The parameters of interest are the mean and standard deviation across microsatellites of the scaled ancestral mutation rate (θanc = 4Neu) and the proportion of males obtaining access to matings per breeding season (ω). By simulation, we assess the properties of the posterior distribution obtained with the various methods. According to our criteria, ABC with summary statistics chosen locally via boosting with the L2-loss performs best. Applying that method to the ibex data, we estimate θ^anc≈1.288 and find that most of the variation across loci of the ancestral mutation rate u is between 7.7 × 10−4 and 3.5 × 10−3 per locus per generation. The proportion of males with access to matings is estimated as ω^≈0.21, which is in good agreement with recent independent estimates.
Limited Evidence for Classic Selective Sweeps in African Populations
Authors: Granka Julie M , Henn Brenna M , Gignoux Christopher R , Kidd Jeffrey M , Bustamante Carlos D , Feldman Marcus W 
Published: September 2012

AbstractWhile hundreds of loci have been identified as reflecting strong-positive selection in human populations, connections between candidate loci and specific selective pressures often remain obscure. This study investigates broader patterns of selection in African populations, which are underrepresented despite their potential to offer key insights into human adaptation. We scan for hard selective sweeps using several haplotype and allele-frequency statistics with a data set of nearly 500,000 genome-wide single-nucleotide polymorphisms in 12 highly diverged African populations that span a range of environments and subsistence strategies. We find that positive selection does not appear to be a strong determinant of allele-frequency differentiation among these African populations. Haplotype statistics do identify putatively selected regions that are shared across African populations. However, as assessed by extensive simulations, patterns of haplotype sharing between African populations follow neutral expectations and suggest that tails of the empirical distributions contain false-positive signals. After highlighting several genomic regions where positive selection can be inferred with higher confidence, we use a novel method to identify biological functions enriched among populations’ empirical tail genomic windows, such as immune response in agricultural groups. In general, however, it seems that current methods for selection scans are poorly suited to populations that, like the African populations in this study, are affected by ascertainment bias and have low levels of linkage disequilibrium, possibly old selective sweeps, and potentially reduced phasing accuracy. Additionally, population history can confound the interpretation of selection statistics, suggesting that greater care is needed in attributing broad genetic patterns to human adaptation.