bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel HIV treatment model using private practitioners in South Africa
Authors: Innes Craig , Hamilton Robin , Hoffmann Christopher J , Hippner Piotr , Fielding Katherine , Grant Alison D , Churchyard Gavin J , Charalambous Salome 
Published: February 2012

ObjectivesThe extent of the HIV epidemic in South Africa may render the public sector capacity inadequate to manage all patients requiring antiretroviral treatment (ART). Private practitioners are an underutilised resource.MethodsThe authors developed a model of care using 72 private practitioners in five provinces in urban and rural areas of South Africa with centralised clinical support, training, pharmacy control and data management. The authors describe the programme, its quality control measures and patient outcomes using a cohort analysis.ResultsBetween January 2005 and December 2008, 9102 individuals were started on ART, 62% female, median age 34 years, median viral load 50 655 copies/ml and median baseline CD4 count 123 cells/μl. Retention (alive and in care) after 12 months was 63% in the 2005 cohort (646 of 1026) and remained similar in the other calendar years, 58%, 68% and 64% in 2006, 2007 and 2008, respectively. After 36 months, retention was 50% and 41% for those enrolled in 2005 and 2006, respectively. The percentage virally suppressed remained similar at 6 months, 82% vs 84%, 84% and 85% from 2005, 2006, 2007 to 2008, respectively, p=0.66; but improved slightly at 12 months, 78% vs 83%, 83% and 84% from 2005 to 2008, p=0.05. At 36 months, it was 84% and 82% for the 2005 and 2006 cohorts, respectively.ConclusionsThe results show that a well-managed private practitioner model can achieve comparable results to public services, although long-term retention needs further evaluation. This model of ART delivery can be used to expand access to ART in areas where the public sector is unable to meet the demand.
INTERMITTENCY AND INTERIOR CRISIS AS ROUTE TO CHAOS IN DYNAMIC WALKING OF TWO BIPED ROBOTS
Authors: GRITLI HASSENE , BELGHITH SAFYA , KHRAEIF NAHLA 
Published: February 2012

Recently, passive and semi-passive dynamic walking has been noticed in researches of biped walking robots. Such biped robots are well-known that they demonstrate only a period-doubling route to chaos while walking down sloped surfaces. In previous researches, such route was shown with respect to a continuous change in some parameter of the biped robot. In this paper, two biped robots are introduced: the passive compass-gait biped robot and the semi-passive torso-driven biped robot. The period-doubling scenario route to chaos is revisited for the first biped as the ground slope changes. Furthermore, we will show through bifurcation diagram that the torso-driven biped exhibits also such route to chaos when the slope angle is varied. For such biped, a modified semi-passive control law is introduced in order to stabilize the torso at some desired position. In this work, we will show through bifurcation diagrams that the dynamic walking of the two biped robots reveals two other routes to chaos namely the intermittency route and the interior crisis route. We will stress that the intermittency is generated via a saddle-node bifurcation where an unstable periodic orbit is created. We will highlight that such event takes place for a Type-I intermittency. However, we will emphasize that the interior crisis event occurs when a collision of the unstable periodic orbit with a weak chaotic attractor happens giving rise to a strong chaotic attractor. In addition, we will explore the intermittent step series induced by the interior crisis and also by the Type-I intermittency. In this study, our analysis on chaos and the routes to chaos will be based, beside bifurcation diagrams, on Lyapunov exponents and fractal (Lyapunov) dimension. These two tools are plotted in the parameter space to classify attractors observed in bifurcation diagrams.
Evaluating Pathogenicity of Rare Variants From Dilated Cardiomyopathy in the Exome Era
Authors: Norton Nadine , Robertson Peggy D. , Rieder Mark J. , Züchner Stephan , Rampersaud Evadnie , Martin Eden , Li Duanxiang , Nickerson Deborah A. , Hershberger Ray E. 
Published: February 2012

Background—
Human exome sequencing is a recently developed tool to aid in the discovery of novel coding variants. Now broadly applied, exome sequencing data sets provide a novel opportunity to evaluate the allele frequencies of previously published pathogenic rare variants.

Methods and Results—

We examined the exome data set from the National Heart, Lung and Blood Institute Exome Sequencing Project and compared this data set with a catalog of 197 previously published rare variants reported as causative of dilated cardiomyopathy (DCM) from familial and sporadic cases. Of these 197, 33 (16.8%) were also present in the Exome Sequencing Project database, raising the question of whether they were uncommon polymorphisms. Supporting functional data has been published for 14 of the 33 (42%), suggesting they are unlikely to be false-positives. The frequencies of these functional variants in the Exome Sequencing Project data set ranged from 0.02 to 1.33% (median 0.04%), which when applied as a cutoff to filter variants in a DCM pedigree identified an additional DCM candidate gene. A greater proportion of sporadic DCM cases had variants that were present in the Exome Sequencing Project data set versus novel variants (ie, not in the Exome Sequencing Project; 44% versus 21%;
P
=0.002), suggesting some of the variants identified as disease causing in sporadic DCM are either false-positives or low penetrance alleles in human populations.

Conclusions—
Rare nonsynonymous variants identified in DCM subjects also present at very low frequencies in public databases are likely relevant for DCM. Allele frequencies >0.04% are of less certain pathogenicity, especially if identified in sporadic cases, although this cutoff should be viewed as preliminary.
Can minimized cardiopulmonary bypass systems be safer?
Authors: Ganushchak YM , Ševerdija EE , Simons AP , van Garsse L , Weerwind PW 
Published: February 2012

Although a growing body of evidence indicates superiority of minimized cardiopulmonary bypass (mCPB) systems over conventional CPB systems, limited venous return can result in severe fluctuations of venous line pressure which can result in gaseous emboli. In this study, we investigated the influence of sub-atmospheric pressures and volume buffer capacity added to the venous line on the generation of gaseous emboli in the mCPB circuit. Two different mCPB systems (MEC - Maquet, n=7 and ECC.O - Sorin, n=8) and a conventional closed cardiopulmonary bypass (cCPB) system (n=12) were clinically evaluated. In the search for a way to increase volume buffer capacity of mCPB systems, we additionally evaluated the ‘Better Bladder’ (BB) in a mock circulation by simulating, repeatedly, decreased venous return while measuring pressure and gaseous embolic activity. Arterial gaseous emboli activity during clinical perfusion with a cCPB system was the lowest in comparison to the mCPB systems (312±465 versus 311±421 with MEC and 1,966±1,782 with ECC.O, counts per 10 minute time interval, respectively; p=0.03). The average volume per bubble in the arterial line was the highest in cases with cCPB (12.5±8.3 nL versus 8.0±4.2 nL with MEC and 4.6±4.8 nL with ECC.O; p=0.04 for both). Significant cross-correlation was obtained at various time offsets from 0 to +35 s between sub-atmospheric pressure in the venous line and gaseous emboli activity in both the venous and arterial lines. The in vitro data showed that incorporation of the BB dampens fluctuations of venous line pressure by approximately 30% and decreases gaseous emboli by up to 85%. In conclusion, fluctuations of sub-atmospheric venous line pressure during kinetic-assisted drainage are related to gaseous emboli. Volume buffer capacity added to the venous line can effectively dampen pressure fluctuations resulting from abrupt changes in venous return and, therefore, can help to increase the safety of minimized cardiopulmonary bypass by reducing gaseous microemboli formation resulting from degassing.
Pressure Cooker Politics: Partisanship and Symbolism in State Certification of Federal Stimulus Funds
Authors: Miller Edward Alan , Blanding David 
Published: February 2012

AbstractTo access funds from the American Recovery and Reinvestment Act (ARRA) of 2009, state governors had to formally certify their intent to do so within 45 days of the law's enactment. All governors eventually certified, but with considerable variation in celerity. This study employs event history techniques to model the probability of certifying the ARRA. It argues that the statute's design combined with economic distress within the states rendered manifest rejection of the law politically infeasible but, for state officials with certain partisan commitments, left open the possibility of symbolic resistance or support in the form of time to certification. State leaders relied on party identification to guide their decisions, resulting in markedly different propensities toward certification for Republican and Democratic governors. Results lend credence to this thesis: States with Republican governors were nearly 60% less likely to certify the ARRA on a given day than states with Democratic governors. This finding suggests that when economic constraints and policy design foreclose actual rejection of a federal law, state policymakers may rely on party labels to register their approbation or disapprobation through other means, including the amount of time taken to accept federal funding.
The embryonic origins of erythropoiesis in mammals
Authors: Baron Margaret H. , Isern Joan , Fraser Stuart T. 
Published: February 2012

AbstractErythroid (red blood) cells are the first cell type to be specified in the postimplantation mammalian embryo and serve highly specialized, essential functions throughout gestation and postnatal life. The existence of 2 developmentally and morphologically distinct erythroid lineages, primitive (embryonic) and definitive (adult), was described for the mammalian embryo more than a century ago. Cells of the primitive erythroid lineage support the transition from rapidly growing embryo to fetus, whereas definitive erythrocytes function during the transition from fetal life to birth and continue to be crucial for a variety of normal physiologic processes. Over the past few years, it has become apparent that the ontogeny and maturation of these lineages are more complex than previously appreciated. In this review, we highlight some common and distinguishing features of the red blood cell lineages and summarize advances in our understanding of how these cells develop and differentiate throughout mammalian ontogeny.
HTreeQA: Using Semi-Perfect Phylogeny Trees in Quantitative Trait Loci Study on Genotype Data
Authors: Zhang Zhaojun , Zhang Xiang , Wang Wei 
Published: February 2012

AbstractWith the advances in high-throughput genotyping technology, the study of quantitative trait loci (QTL) has emerged as a promising tool to understand the genetic basis of complex traits. Methodology development for the study of QTL recently has attracted significant research attention. Local phylogeny-based methods have been demonstrated to be powerful tools for uncovering significant associations between phenotypes and single-nucleotide polymorphism markers. However, most existing methods are designed for homozygous genotypes, and a separate haplotype reconstruction step is often needed to resolve heterozygous genotypes. This approach has limited power to detect nonadditive genetic effects and imposes an extensive computational burden. In this article, we propose a new method, HTreeQA, that uses a tristate semi-perfect phylogeny tree to approximate the perfect phylogeny used in existing methods. The semi-perfect phylogeny trees are used as high-level markers for association study. HTreeQA uses the genotype data as direct input without phasing. HTreeQA can handle complex local population structures. It is suitable for QTL mapping on any mouse populations, including the incipient Collaborative Cross lines. Applied HTreeQA, significant QTLs are found for two phenotypes of the PreCC lines, white head spot and running distance at day 5/6. These findings are consistent with known genes and QTL discovered in independent studies. Simulation studies under three different genetic models show that HTreeQA can detect a wider range of genetic effects and is more efficient than existing phylogeny-based approaches. We also provide rigorous theoretical analysis to show that HTreeQA has a lower error rate than alternative methods.
Accelerating the Inbreeding of Multi-Parental Recombinant Inbred Lines Generated By Sibling Matings
Authors: Welsh Catherine E , McMillan Leonard 
Published: February 2012

Abstract
Inbred model organisms are powerful tools for genetic studies because they provide reproducible genomes for use in mapping and genetic manipulation. Generating inbred lines via sibling matings, however, is a costly undertaking that requires many successive generations of breeding, during which time many lines fail. We evaluated several approaches for accelerating inbreeding, including the systematic use of back-crosses and marker-assisted breeder selection, which we contrasted with randomized sib-matings. Using simulations, we explored several alternative breeder-selection methods and monitored the gain and loss of genetic diversity, measured by the number of recombination-induced founder intervals, as a function of generation. For each approach we simulated 100,000 independent lines to estimate distributions of generations to achieve full-fixation as well as to achieve a mean heterozygosity level equal to 20 generations of randomized sib-mating. Our analyses suggest that the number of generations to fully inbred status can be substantially reduced with minimal impact on genetic diversity through combinations of parental backcrossing and marker-assisted inbreeding. Although simulations do not consider all confounding factors underlying the inbreeding process, such as a loss of fecundity, our models suggest many viable alternatives for accelerating the inbreeding process.
Haplotype Probabilities in Advanced Intercross Populations
Authors: Broman Karl W 
Published: February 2012

Abstract
Advanced intercross populations, in which multiple inbred strains are mated at random for many generations, have the advantage of greater precision of genetic mapping because of the accumulation of recombination events across the multiple generations. Related designs include heterogeneous stock and the diversity outcross population. In this article, I derive the two-locus haplotype probabilities on the autosome and X chromosome with these designs. These haplotype probabilities provide the key quantities for developing hidden Markov models for the treatment of missing genotype information. I further derive the map expansion in these populations, which is the frequency of recombination breakpoints on a random chromosome.
Experiments Probing Fundamental Mechanisms of Energetic Material Initiation and Ignition
Authors: Berg Christopher M. , Brown Kathryn E. , Conner Rusty W. , Fu Yuanxi , Fujiwara Hiroki , Lagutchev Alexei , Shaw William L. , Zheng Xianxu , Dlott Dana D. 
Published: February 2012

ABSTRACTTwo fundamental processes associated with shock compression of energetic materials (EM) are initiation and ignition. Initiation occurs just behind a shock front and ignition occurs anywhere from a few nanoseconds to hundreds of nanoseconds later. Experiments are described that probe the fundamental mechanisms of these processes on relevant length and time scales: picosecond vibrational spectroscopy of nanometer thick layers of energetic materials (EM) with laser-driven shock waves, and nanosecond emission spectroscopy of micrometer thick layers of EM using laser-driven flyer plates.
An Extensive Theoretical Study of the Phonon Conductivity and Thermoelectric Properties of SiGe Alloys
Authors: Thomas Iowerth O. , Srivastava Gyaneshwar P. 
Published: February 2012

ABSTRACTWe present an extensive theoretical study of the phonon conductivity and thermoelectric properties of SiGe alloys. Phonon dispersion relations and group velocities – required for conductivity calculations – are obtained by employing the density-functional-perturbation scheme. The cubic anharmonic potential has been expressed by treating the Gr¨uneisen constant as a semi-adjustable mode-averaged parameter. Calculations are also performed, within the nearly-free-electron approximation, for the temperature variation of the Fermi energy, Seebeck coefficient, electrical conductivity, and electronic polar and bipolar contributions to thermal conductivity. Results are compared with experimental measurements for n-doped pressure-sintered Si0.754Ge0.246 alloy. Using these results, we compare our results for the thermoelectric figure-of-merit with previously reported results based on an empirical approach for phonon conductivity.
The Expert and the Lay Public: Reflections on Influenza A (H1N1) and the Risk Society
Authors: Dupras Charles , Williams-Jones Bryn 
Published: February 2012

Trust between the lay public and scientific experts is a key element to ensuring the efficient implementation of emergency public health measures.In modern risk societies, the management and elimination of risk have become preeminent drivers of public policy. In this context, the protection of public trust is a complex task. Those actors involved in public health decision-making and implementation (e.g., mass vaccination for influenza A virus) are confronted with growing pressures and responsibility to act. However, they also need to accept the limits of their own expertise and recognize the ability of lay publics to understand and be responsible for public health.Such a shared responsibility for risk management, if grounded in participative public debates, can arguably strengthen public trust in public health authorities and interventions.
Investigations of Selected Historically Important Syndromic Outbreaks: Impact and Lessons Learned for Public Health Preparedness and Response
Authors: Goodman Richard A. , Posid Joseph M. , Popovic Tanja 
Published: February 2012

Public health readiness has increased at all jurisdictional levels because of increased sensitivity to threats. Since 2001, with billions of dollars invested to bolster the public health system’s capacity, the public expects that public health will identify the etiology of and respond to events more rapidly. However, when etiologies are unknown at the onset of the investigation but interventions must be implemented, public health practitioners must benefit from past investigations’ lessons to strengthen preparedness for emerging threats. We have identified such potentially actionable lessons learned from historically important public health events that occurred primarily as syndromes for which the etiological agent initially was unknown. Ongoing analysis of investigations can advance our capability to recognize and investigate syndromes and other problems and implement the most appropriate interventions.
Socioeconomic Status and Adolescent Mental Disorders
Authors: McLaughlin Katie A. , Costello E. Jane , Leblanc William , Sampson Nancy A. , Kessler Ronald C. 
Published: February 2012

Objectives. Although previous research has shown that low socioeconomic status (SES) is associated with mental illness, it is unclear which aspects of SES are most important. We investigated this issue by examining associations between 5 aspects of SES and adolescent mental disorders. Methods. Data came from a national survey of US adolescents (n = 6483). Associations among absolute SES (parental income and education), relative SES (relative deprivation, subjective social status), and community level income variation (Gini coefficient) with past-year mental disorders were examined. Results. Subjective social status (mean 0, variance 1) was most consistently associated with mental disorder. Odds ratios with mood, anxiety, substance, and behavior disorders after controlling for other SES indicators were all statistically significant and in the range of 0.7 to 0.8. Associations were strongest for White adolescents. Parent education was associated with low risk for anxiety disorder, relative deprivation with high risk for mood disorder, and the other 2 indicators were associated with none of the disorders considered. Conclusions. Associations between SES and adolescent mental disorders are most directly the result of perceived social status, an aspect of SES that might be more amenable to interventions than objective aspects of SES.
Surveillance for Guillain–Barré Syndrome After Influenza Vaccination Among the Medicare Population, 2009–2010
Authors: Burwen Dale R. , Sandhu Sukhminder K. , MaCurdy Thomas E. , Kelman Jeffrey A. , Gibbs Jonathan M. , Garcia Bruno , Markatou Marianthi , Forshee Richard A. , Izurieta Hector S. , Ball Robert ,   the Safety Surveillance Working Group
Published: February 2012

Objectives. We implemented active surveillance for Guillain–Barré syndrome (GBS) following seasonal or H1N1 influenza vaccination among the Medicare population during the 2009-2010 influenza season. Methods. We used weekly Medicare claims data to monitor vaccinations and subsequent hospitalizations with principal diagnosis code for GBS within 42 days. Group sequential testing assessed whether the observed GBS rate exceeded a critical limit based on the expected rate from 5 previous years adjusted for claims delay. We evaluated the lag between date of service and date of claims availability and used it for adjustment. Results. By July 30, 2010 (after 26 interim surveillance tests), 14.0 million seasonal and 3.3 million H1N1 vaccinations had accrued. Taking into account claims delay appropriately lowered the critical limit during early monitoring. The observed GBS rate was below the critical limit throughout the surveillance. Conclusions. Medicare data contributed rapid safety monitoring among millions of 2009–2010 influenza vaccine recipients. Adjustment for claims delay facilitates early detection of potential safety issues. Although limited by lack of medical record review to confirm cases, this claims-based surveillance did not indicate a statistically significant elevated GBS rate following seasonal or H1N1 influenza vaccination.