bluuebunny/crossref_metadata_2025 huggingface dataset:
Depression and the Health Care Experiences of Medicare Beneficiaries
Authors: Martino Steven C. , Elliott Marc N. , Kanouse David E. , Farley Donna O. , Burkhart Q. , Hays Ron D.
Published: July 2011

Objectives. To compare health care experiences of Medicare beneficiaries with and without symptoms of depression and investigate the role of patient confidence in shaping these experiences.

Data Sources. Data came from the 2009 CAHPS Medicare 4.0 Fee‐for‐Service (FFS) Survey, which was fielded to a national probability sample of 298,492 FFS Medicare beneficiaries.

Study Design. Linear regression was used to model associations of depression with four global ratings and three composite measures of health care and to test whether beneficiaries' confidence in their ability to recognize the need for care mediates these associations.

Principal Findings. Beneficiaries with depressive symptoms reported worse experiences with care across the full range of patient experience covered by the CAHPS survey. Depressive symptoms were associated with decreased patient confidence and decreased confidence was in turn associated with poorer reports of care.

Conclusions. Our study highlights depressive symptoms as a risk factor for poorer experiences of health care and highlights depressed patients' confidence in recognizing their need for care and for designing programs to improve the health care of this population.
Hepatitis D virus‐specific cytokine responses in patients with chronic hepatitis delta before and during interferon alfa‐treatment
Authors: Grabowski Jan , Yurdaydìn Cihan , Zachou Kalliopi , Buggisch Peter , Hofmann Wolf P. , Jaroszewicz Jerzy , Schlaphoff Verena , Manns Michael P. , Cornberg Markus , Wedemeyer Heiner ,   the HIDIT‐1 study group
Published: July 2011

Background: Hepatitis delta is caused by infection with the hepatitis D virus (HDV) and is considered the most severe form of viral hepatitis. Treatment options for hepatitis delta are limited, with only 25% of patients responding to interferon (IFN)‐alfa‐based therapies. The role of the adaptive immune system in controlling HDV infection during spontaneous or treatment‐induced viral clearance is not well understood.

Methods: We studied HDV‐specific cytokine production of peripheral blood mononuclear cells stimulated with HDV peptide pools as well as serum cytokine levels in well‐characterized patients with chronic HDV infection before and during pegylated‐interferon‐alfa±adefovir therapy.

Results: Hepatitis D virus‐specific interleukin (IL)‐2, IFN‐γ‐, interferon‐inducible protein‐10 and IL‐10‐responses were detectable in 53%, 35%, 65% and 6% of hepatitis delta patients. HDV‐specific IFN‐γ responses tended to be more common in patients with low HDV viral loads. HDV‐specific cytokine responses declined during pegylated (PEG)‐IFNa therapy and patterns of changes were associated with the treatment response. Serum cytokine levels also showed distinct changes during PEG‐IFNa treatment.

Conclusion: We suggest that cellular HDV‐specific immune responses contribute to the control of HDV infection and that cytokine responses may indicate response to type‐I‐IFN‐based antiviral therapy of hepatitis delta.
A comparative evaluation of rotation thromboelastometry and standard coagulation tests in hemodilution‐induced coagulation changes after cardiac surgery
Authors: Ogawa Satoru , Szlam Fania , Chen Edward P. , Nishimura Takashi , Kim Heezoo , Roback John D. , Levy Jerrold H. , Tanaka Kenichi A.
Published: July 2011

BACKGROUND: Coagulopathy after cardiopulmonary bypass (CPB) is caused by multiple perturbations in cellular and humoral elements of coagulation. A timely and comprehensive method to evaluate hemostasis would be helpful in the management of bleeding patients after CPB. The assessment of whole blood coagulation using rotation thromboelastometry (ROTEM) was compared to coagulation tests routinely performed during cardiac surgery.

STUDY DESIGN AND METHODS: Blood was obtained from 26 patients undergoing CPB surgery at baseline, at 60 minutes on CPB, at the end of CPB, and on admission to intensive care unit. ROTEM tests (extrinsically activated [EXTEM], intrinsically activated [INTEM], specific clot formation [FIBTEM]), prothrombin time, activated partial thromboplastin time, platelet (PLT) count, fibrinogen, prothrombin level, antithrombin level, and thrombin generation (TG) measurement were performed.

RESULTS: We observed strong correlations between FIBTEM‐amplitude at 10 minutes (A10) and fibrinogen level (r = 0.87; p < 0.001) and between EXTEM/ INTEM‐A10 variables and PLT count (r = 0.72 and 0.67, respectively; p < 0.001). Receiver operating characteristic analysis demonstrated that EXTEM‐A10 and INTEM‐A10 are predictive of thrombocytopenia below 80 × 109/L (area under the curve [AUC], 0.83 and 0.82, respectively), and FIBTEM‐A10 was highly predictive of fibrinogen level below 200 mg/dL (AUC, 0.96). There were only weak correlations found between TG peak and clot formation time of EXTEM or INTEM (r = 0.30 and 0.29, respectively; p < 0.05).

CONCLUSION: ROTEM variables demonstrated clinically relevant correlations with PLT counts and fibrinogen levels. In particular, decreasing levels of fibrinogen can be quickly determined (<15‐20 min) using FIBTEM.
A Broad Symmetry Criterion for Nonparametric Validity of Parametrically Based Tests in Randomized Trials
Authors: Shinohara Russell T. , Frangakis Constantine E. , Lyketsos Constantine G.
Published: July 2011

Summary Pilot phases of a randomized clinical trial often suggest that a parametric model may be an accurate description of the trial’s longitudinal trajectories. However, parametric models are often not used for fear that they may invalidate tests of null hypotheses of equality between the experimental groups. Existing work has shown that when, for some types of data, certain parametric models are used, the validity for testing the null is preserved even if the parametric models are incorrect. Here, we provide a broader and easier to check characterization of parametric models that can be used to (i) preserve nonparametric validity of testing the null hypothesis, i.e., even when the models are incorrect, and (ii) increase power compared to the non‐ or semiparametric bounds when the models are close to correct. We demonstrate our results in a clinical trial of depression in Alzheimer’s patients.
Mechanical and Electrical Properties of Multiwalled CNT‐Alumina Nanocomposites Prepared by a Sequential Two‐Step Processing of Ultrasonic Spray Pyrolysis and Spark Plasma Sintering
Authors: Lee Kyubock , Mo Chan Bin , Park Seung Bin , Hong Soon Hyung
Published: July 2011

The high tensile strength and electrical conductivity as well as high aspect ratio of carbon nanotube (CNT) are known to effectively improve the brittleness and electrical properties of ceramic materials; however, the agglomeration of CNTs during in the synthetic process and the poor interfacial bonding between CNTs and matrix materials still present challenges. Herein, multiwalled carbon nanotube (MWNT)‐alumina composites were prepared, with homogeneously dispersed MWNTs in an alumina matrix, using a sequential two‐step process via ultrasonic spray pyrolysis followed by a spark plasma sintering process. To mix these two materials at the molecular level, MWNT‐alumina composites were prepared using a precursor solution containing Al ions instead of solid aluminum oxide particles as the starting material. The agglomeration of MWNTs at high concentration, which is a main obstacle to solution processing, was minimized using ultrasonic spray pyrolysis. The dc conductivity of pure α‐alumina, possessing substantial insulating properties, was increased to 12.2 S/m by incorporating 2.48 wt% of MWNTs with a low percolation threshold under 0.18 wt%. With the same amount of MWNT, the fracture toughness of the composite was increased 2.5 times. The improved electrical and mechanical properties of the composites are discussed based on the microstructural characteristics of the composites.
Hydrothermal Synthesis of Nanosized Na0.5Bi0.5TiO3
Authors: Šetinc Tina , Spreitzer Matjaž , Logar Manca , Suvorov Danilo
Published: July 2011

The synthesis of sodium bismuth titanate Na0.5Bi0.5TiO3 (NBT) was studied using the hydrothermal treatment of TiO2 (anatase) and Bi(NO3)3·5H2O in a highly concentrated NaOH solution. The process parameters such as the alkaline conditions, the temperature, the reaction time, and the concentration, as well as the influence of the Bi/Ti ratio and microwave heating were investigated in detail. The as‐prepared NBT powders were characterized by X‐ray powder diffraction, transmission electron microscopy, energy‐dispersive spectrometry, and inductively coupled plasma atomic emission spectrometry. The results show that secondary sodium titanate phases formed along with the NBT phase in the initial stage of the reaction. Their stability was susceptible to the treatment conditions and the Bi/Ti ratio. Pure and well crystallized NBT nanoparticles were obtained after 48 h of reaction time at 200°C, 12M NaOH, 0.1M Bi(NO3)3·5H2O and a stoichiometric amount of TiO2 relative to the Bi precursor. A chemical analysis of the powders showed a slight sodium deficiency and bismuth surplus with respect to their nominal composition, i.e., Na:Bi:Ti = 0.47 ± 0.02:0.53 ± 0.02:1.00 ± 0.04. The obtained NBT particles were 50–100 nm in size and exhibited great potential for further integration in composite thin films.
Surface Modification and Microstructure Design of Alumina Ceramics
Authors: Liu Zifeng , Shao Shuqing , Hu Xiaozhi , Wang Xin
Published: July 2011

Microstructures and properties of alumina ceramics are sensitive to sintering additives, and commercially available ready‐to‐press alumina powders may not contain required sintering additives for specific applications. We show a simple and practical way of microstructure design of alumina ceramics made from the commercial powders through surface modification. The method utilizes the micro‐porous feature of an alumina green body pre‐sintered at 1000°C, and deposits ultra‐low‐density sintering additive slips onto the micro‐porous substrate. The surface microstructures can be refined if an ultra‐low‐density MgO or SiO2 slip is deposited onto the substrate, whereas a TiO2 slip leads to coarser and extended grain structures. TiO2/MgO, SiO2/MgO, and TiO2/SiO2 combinations have also been tested, so that various surface modifications can be achieved.
Electric Current Pulse Activated 6H→3C Transformation in Silicon Carbide Compacts
Authors: Limeng Liu , Feng Ye , Yu Zhou
Published: July 2011

6H‐SiC powder mixed with Si3N4, Al2O3, Y2O3, and AlN was sintered in a spark plasma sintering (SPS) equipment. The 6H→3C SiC transformation was concerned. Research results indicated the polytype transformation completed in less than 30 s by imposing a 14 458 W (6.2 V, 2332 A) transitory DC current at 1700°C upon cooling down from 2000°C. The fast transformation kinetic and the significant 3C‐SiC grain growth accompanying the phase transformation were suspected to be correlated with the pulsed SPS direct current.
Preparation and Characterization of Lanthanum Strontium Manganite Thin Films by Metal‐Organic Chemical Liquid Deposition
Authors: Chen Ying , Zhu Junyu , Zhang Shuai , Dong Xianlin , Lei Xiuyun , Tang Xiaodong , Wang Genshui
Published: July 2011

Lanthanum strontium manganite La0.7Sr0.3MnO3 thin films have been grown successfully on Si(001) by metal‐organic chemical liquid deposition technique using acetate as the starting materials, and acetic acid and deionized water as the solvent. Crack free, low surface roughness, preferential orientation films with a large MR over a wide temperature range were obtained, which make them very interesting as spin source in Si‐based technology. The effects of the high magnetic field and temperature on the electrical, magnetic, and magneto‐transport performance were investigated. The relationship between the thermal annealing conditions, microstructure, and the physical properties of the present films were discussed.
Prevalence of Trichomonas vaginalis Infection in Symptomatic Adolescent Females Presenting to a Pediatric Emergency Department
Authors: Goyal Monika , Hayes Katie , McGowan Karin L. , Fein Joel A. , Mollen Cynthia
Published: July 2011

ACADEMIC EMERGENCY MEDICINE 2011; 18:763–766 © 2011 by the Society for Academic Emergency Medicine

Objectives:  Adolescent females are disproportionately affected by sexually transmitted infections (STIs). Although Trichomonas vaginalis (TV) has been declared the most common nonviral STI, TV testing is not routinely conducted in the emergency department (ED), and when it is performed, insensitive testing methods are often used. Therefore, this study sought to determine the prevalence of TV and factors associated with TV infection among symptomatic adolescent females presenting to a pediatric ED.

Methods:  This was a prospective prevalence study of female patients ages 14 to 19 years presenting to a pediatric ED with lower abdominal pain and/or genitourinary (GU) complaints. Patients were tested for TV, Neisseria gonorrhoeae (GC), and Chlamydia trachomatis (CT).

Results:  Of the 276 patients who met inclusion criteria, 203 underwent TV testing; prevalence was 9.9% (95% confidence interval [CI] = 5.7% to 14.0%). Assuming all eligible patients who did not have TV testing were not infected with TV, sensitivity analysis revealed a minimum TV prevalence of 7.2% (95% CI = 4.2% to 10.3%). The overall prevalence of any STI was 22.5% (95% CI = 17.5% to 27.4%), with CT being the most prevalent (19.7%; 95% CI = 14.5 to 24.9). Aside from vaginal discharge (odds ratio [OR] = 3.7; 95% CI = 1.1 to 11.3), there were no other factors significantly associated with TV infection.

Conclusions:  A substantial proportion of adolescent females presenting to a pediatric ED with lower abdominal or GU symptoms had TV infection. TV testing should be considered as part of the evaluation of adolescent females presenting to the ED with lower abdominal, urinary, or vaginal complaints.
Early Career Academic Productivity Among Emergency Physicians With R01 Grant Funding
Authors: Scott Van Epps J. , Younger John G.
Published: July 2011

ACADEMIC EMERGENCY MEDICINE 2011; 18:759–762 © 2011 by the Society for Academic Emergency Medicine

Objectives:  The objective was to describe the early academic career activities of emergency physician (EP) scientists with recent Research Project Grant Program (R01) grant funding from the National Institutes of Health (NIH).

Methods:  The curricula vitae of all EP scientists in the United States currently funded by the NIH were analyzed for evidence of advanced research training and frequency and type of publication and grant writing. Each investigator was surveyed for demographic features and estimation of protected time during their early career development.

Results:  Eighteen investigators were identified. The median length of time from completion of residency to receipt of their first R01 grant was 11 years (interquartile range [IQR] = 11 to 15 years), and the median age of investigators at the time of this award was 43 years (IQR = 39 to 47 years). At the time of their award, researchers were publishing five peer‐reviewed manuscripts a year (IQR = 1 to 8 manuscripts) and had already received considerable external funding. Ninety‐four percent of those studied had pursued a research fellowship, an advanced degree, or an NIH K‐award following residency.

Conclusions:  For EPs, receipt of an R01 from the NIH requires more than a decade of work following the completion of training. This period is characterized by pursuit of advanced research training, active and accelerating publication and collaboration, and acquisition of smaller extramural grants.
Electrocardiogram Findings in Emergency Department Patients with Syncope
Authors: Quinn James , McDermott Daniel
Published: July 2011

ACADEMIC EMERGENCY MEDICINE 2011; 18:714–718 © 2011 by the Society for Academic Emergency Medicine

Objectives:  To determine the sensitivity and specificity of the San Francisco Syncope Rule (SFSR) electrocardiogram (ECG) criteria for determining cardiac outcomes and to define the specific ECG findings that are the most important in patients with syncope.

Methods:  A consecutive cohort of emergency department (ED) patients with syncope or near syncope was considered. The treating emergency physicians assessed 50 predictor variables, including an ECG and rhythm assessment. For the ECG assessment, the physicians were asked to categorize the ECG as normal or abnormal based on any changes that were old or new. They also did a separate rhythm assessment and could use any of the ECGs or available monitoring strips, including prehospital strips, when making this assessment. All patients were followed up to determine a broad composite study outcome. The final ECG criterion for the SFSR was any nonsinus rhythm or new ECG changes. In this specific study, the initial assessments in the database were used to determine only cardiac‐related outcomes (arrhythmia, myocardial infarction, structural, sudden death) based on set criteria, and the authors determined the sensitivity and specificity of the ECG criteria for cardiac outcomes only. All ECGs classified as “abnormal” by the study criteria were compared to the official cardiology reading to determine specific findings on the ECG. Univariate and multivariate analysis were used to determine important specific ECG and rhythm findings.

Results:  A total of 684 consecutive patients were considered, with 218 having positive ECG criteria and 42 (6%) having important cardiac outcomes. ECG criteria predicted 36 of 42 patients with cardiac outcomes, with a sensitivity of 86% (95% confidence interval [CI] = 71% to 94%), a specificity of 70% (95% CI = 66% to 74%), and a negative predictive value of 99% (95% CI = 97% to 99%). Regarding specific ECG findings, any nonsinus rhythm from any source and any left bundle conduction problem (i.e., any left bundle branch block, left anterior fascicular block, left posterior fascicular block, or QRS widening) were 2.5 and 3.5 times more likely associated with significant cardiac outcomes.

Conclusions:  The ECG criteria from the SFSR are relatively simple, and if used correctly can help predict which patients are at risk of cardiac outcomes. Furthermore, any left bundle branch block conduction problems or any nonsinus rhythms found during the ED stay should be especially concerning for physicians caring for patients presenting with syncope.
Intracolonial differences in gut bacterial community between worker and soldier castes of Coptotermes formosanus
Authors: Xiang Hui , Xie Lei , Zhang Jun , Long Yan‐Hua , Liu Ning , Huang Yong‐Ping , Wang Qian
Published: July 2011

Abstract  The establishment of symbiotic relationships with intestinal microorganisms enables termites to thrive on recalcitrant substrates such as cellulose and wood. A termite colony is composed of several different castes which have distinct feeding habits. The soldiers, for example, cannot feed by themselves and depend on workers, who feed them with digested or semi‐digested foods. To investigate the influence of feeding habits on the bacterial symbionts, a comparative study of gut bacteria between worker and soldier castes of the termite Coptotermes formosanus was conducted. The bacterial communities of both castes were investigated using denaturing gradient gel electrophoresis (DGGE) and clonal analysis of 16S ribosomal DNA (rDNA). Both methods indicated Bacteroidetes was the common predominant group; the common dominant phylotype was affiliated with a reported uncultured Bacteroidetes phylotype (BCf1–03). There were significant differences in Bacteroidetes and Spirochaetes between two castes. Compared to the gut bacteria of workers, those of soldiers were lower in abundance and diversity of Bacteroidetes and slightly higher in Spirochaetes. Two phylotypes (W8, W11) affiliated to Bacteroidetes and two (W26, W29) affiliated to Spirochaetes were exclusively found in the DGGE profile of the worker caste. Bacteroidetes are assumed to be involved in fermentation of sugars and nitrogenous compounds as well as degradation of uric acid. Spirochaetes are supposed to aid in the functions of acetogenesis and N2‐fixation. The different feeding habits between workers and soldiers of C. formosanus may explain the observed differences in the gut bacterial community.
No shallow talk: Cryptic strategy in the vocal communication of Blainville's beaked whales
Authors: Aguilar de Soto Natacha , Madsen Peter T. , Tyack Peter , Arranz Patricia , Marrero Jacobo , Fais Andrea , Revelli Eletta , Johnson Mark
Published: July 2011

Abstract

Communicating animals must balance fitness benefits against the costs of signaling, such as increased predation risk. Cetaceans communicate mainly with sound and near‐surface vocalizations can place signalers at risk from shallow‐diving top‐predators with acute hearing such as killer whales. Beaked whales are deep divers living in small cohesive groups with little social defense from predation. Little if anything is known about their acoustic communication. Here, eight Blainville's beaked whales were studied with suction cup attached DTags to provide the first report on social communication as a function of diving behavior for any of the 21 ziphiid species. Tagged whales produced two previously unrecorded signals with apparent communicative functions: (1) fast series of ultrasonic frequency modulated clicks (rasps) were recorded from six individuals, and (2) harmonically rich short whistles with a mean fundamental frequency of 12 kHz were recorded from one whale at up to 900 m depth, the deepest whistles recorded from a marine mammal. Blainville's were silent 80% of the time, whenever shallower than 170 m depth and during the prolonged (19 min) silent ascents from vocal dives. This behavior limits the ability of shallow‐diving predators to track Blainville's acoustically and may provide a striking example of the evolutionary influence of the risk of predation on animal communication.
Defining bottlenose dolphin (Tursiops truncatus) stocks based on environmental, physical, and behavioral characteristics
Authors: Toth Jacalyn L. , Hohn Aleta A. , Able Kenneth W. , Gorgone Antoinette M.
Published: July 2011

Abstract

The population structure of bottlenose dolphins, Tursiops truncatus, along the U.S. Atlantic coast has recently been redefined from one homogenous population into five coastal stocks. Local studies indicate even finer structure, primarily based on isolation of dolphins inhabiting estuaries. We identified population structuring of non‐estuarine coastal bottlenose dolphins during a study in New Jersey, the northern range along the Atlantic Coast. Using photo‐identification and distribution survey results, an analysis identified two major clusters of individuals significantly separated by five variables (distance from shoreline, group size, occurrence of the barnacle Xenobalanus globicipitis, avoidance behavior, and individual coloration). Sightings assigned to cluster 1 occurred in nearshore shallow waters (0–1.9 km, x̄= 3.5 m), and those assigned to cluster 2 occurred further offshore in deeper waters (1.9–6 km, x̄= 9.5 m). Only eight of 194 individuals (4%) were identified in both regions. Collectively, this suggests an occurrence of two stocks that are spatially, physically, and behaviorally distinguishable over a small distance. These results indicate that complexity in Tursiops population structure is not limited to latitudinal gradients or barriers created by estuarine habitats, but also by partitioning of habitat as a function of distance from shore and depth over small distances.
The behavioral context of common dolphin (Delphinus sp.) vocalizations
Authors: Henderson E. E. , Hildebrand J. A. , Smith M. H. , Falcone E. A.
Published: July 2011

Abstract

Correlations between surface behavior and concurrent underwater vocalizations were modeled for common dolphins (Delphinus spp.) in the Southern California Bight (SCB) over multiple field seasons. Clicks, pulsed calls, and whistles were examined, with a total of 50 call features identified. Call features were used to classify behavior using random forest decision trees, with rates of correct classification reaching 80.6% for fast travel, 84.6% for moderate travel, 59.8% for slow travel, and 58% for foraging behavior. Common dolphins spent most of their time traveling. The highest number of clicks, pulsed calls, and complex whistles were produced during fast travel. In contrast, during foraging there were few pulsed calls and whistles produced, and the whistles were simple with narrow bandwidths and few harmonics. Behavior and vocalization patterns suggest nocturnal foraging in offshore waters as the primary feeding strategy. Group size and spacing were strongly correlated with behavior and rates of calling, with higher call rates in dispersed traveling groups and lower call rates in loosely aggregated foraging groups. These results demonstrate that surface behavior can be classified using vocalization data, which builds the framework for behavioral studies of common dolphins using passive acoustic monitoring techniques.
Estimating the carrying capacity of French Frigate Shoals for the endangered Hawaiian monk seal using Ecopath with Ecosim
Authors: Parrish Frank A. , Howell Evan A. , Antonelis George A. , Iverson Sara J. , Littnan Charles L. , Parrish James D. , Polovina Jeffrey J.
Published: July 2011

Abstract

The carrying capacity of the French Frigate Shoals (FFS) region for the endangered Hawaiian monk seal was appraised using an updated version of the original FFS Ecopath model (Polovina 1984). Model parameters were updated using recent literature, and data from surveys of the seal population and its bottom‐associated prey. Together they produced a static mass balance model for 1998 when the prey surveys began. The Ecopath‐estimated monk seal biomass was 0.0045 t/km2, which was in close agreement with the biomass calculated from monk seal field beach counts (0.0046 t/km2). Model simulations through time were done in Ecosim using the Ecopath balanced model and included fisheries data time series from 1998 to 2008. Monk seal biomass declined concurrently with decreases in benthic bottomfish biomass, which were influenced by large‐scale changes in the environment of the North Pacific. This model scenario was extended from 2010, when the last permitted fishery in the Northwestern Hawaiian Islands was closed, through to 2040, assuming a constant environmental signal. Model results for this time period did not show a recovery of monk seals that exceeded the initial 1998 model biomass levels, highlighting the importance of including environmental variability in estimates of monk seals recovery at FFS.
Stable carbon and nitrogen isotope ratios in muscle and epidermis of arctic whales
Authors: Horstmann‐Dehn Larissa , Follmann Erich H. , Rosa Cheryl , Zelensky Gennady , George Craig
Published: July 2011

Abstract

Collection of minimally invasive biopsy samples has become an important method to establish normal stable isotopes reference ranges in various wildlife species. Baseline data enhance the understanding of feeding ecology, habitat use, and potential food limitation in apparently healthy, free‐ranging cetaceans. Epidermis and muscle were collected from subsistence‐hunted northern Alaskan bowhead (n= 133 epidermis/134 muscle) and beluga whales (n= 42/49) and subsistence‐hunted Russian gray whales (n= 25/17). Additional samples were obtained from gray whales stranded in California (n= 18/11) during mortality events (1999, 2000). Both δ15N and δ13C are trophic position and benthic/pelagic feeding indicators, respectively, in muscle and epidermis. Epidermis is generally enriched in 15N over muscle, while epidermal 13C is more depleted. Lipid extraction does not alter δ15N in either tissue, but affects epidermal δ13C. Nitrogen‐15 is enriched in muscle, but not epidermis of stranded compared to subsistence‐hunted gray whales, indicating probable protein catabolism and nutritional stress in stranded whales. Similarly, epidermal δ13C of harvested whales is lower than in stranded whales, suggesting depleted lipid stores and/or food limitation in stranded animals. Epidermal isotope signatures are similar in both present‐day bowheads and in an ancient sample from the Northern Bering Sea region. Although only one specimen, this suggests trophic level of the ancient whale compares to modern bowheads after a millennium.
Self‐Regulation in Early Childhood: Improving Conceptual Clarity and Developing Ecologically Valid Measures
Authors: McClelland Megan M. , Cameron Claire E.
Published: July 2011

Abstract— Children’s ability to direct their attention and behavior to learning tasks provides a foundation for healthy social and academic development in early schooling. Although an explosion of research on this topic has occurred in recent years, the field has been hindered by a lack of conceptual clarity, as well as debate over underlying components and their significance in predicting school success. In addition, few measures tap these skills as children move into formal schooling. This article describes the aspects of self‐regulation that are most important for early school success. It then discusses methodological challenges in reliably and validly assessing these skills in young children and describes recent advances in direct measures of self‐regulation that are reliable and ecologically valid and that predict children’s school success. It concludes by summarizing critical issues in the study of self‐regulation in school contexts and discussing next steps.
Linking Students’ Emotions and Academic Achievement: When and Why Emotions Matter
Authors: Valiente Carlos , Swanson Jodi , Eisenberg Nancy
Published: July 2011

Abstract—  Few studies include associations of emotions, or of individual differences in emotionality, to academic competence, and there are virtually no empirical data on when or why relations exist (or do not exist). The few studies of emotion and achievement have largely focused on anxiety, but there has been scant theoretical and empirical attention devoted to the treatment of other emotions. It is suggested that considering the moderated and indirect effects of students’ emotions on their academic functioning may provide an understanding of whether and under what circumstances emotions are related to achievement. This article briefly reviews findings linking situational and dispositional negative or positive emotions to academic achievement and suggests that researchers can learn much about relations between emotions and achievement by considering the potential moderating role of effortful control, as well as considering the mediating roles that cognitive processes, motivational mechanisms, and classroom relationships play in linking emotions and achievement.
Plastic Instabilities in Spherical Vessels for Static and Dynamic Loading
Authors: Duffey T. A.
Published: July 2011

Significant changes were made in design limits for pressurized vessels in the 2007 version of the ASME code (Sec. VIII, Div. 3) and 2008 and 2009 Addenda, and these are now a part of the 2010 code. There is now a local damage-mechanics based strain-exhaustion limit, including the well-known global plastic collapse limit. Moreover, Code Case 2564 (Sec. VIII, Div. 3) has recently been approved to address impulsively loaded vessels. It is the purpose of this paper to investigate the plastic collapse limit as it applies to dynamically loaded spherical vessels. Plastic instabilities that could potentially develop in spherical shells under symmetric loading conditions are examined for a variety of plastic constitutive relations. First, literature survey of both static and dynamic instabilities associated with spherical shells is presented. Then, a general plastic instability condition for spherical shells subjected to displacement-controlled and short-duration dynamic pressure loading is given. This instability condition is evaluated for six plastic and viscoplastic constitutive relations. The role of strain rate sensitivity on the instability point is investigated. Conclusions of this work are that there are two fundamental types of instabilities associated with failure of spherical shells. In the case of impulsively loaded vessels, where the pulse duration is short compared with the fundamental period of the structure, one instability type is found not to occur in the absence of static internal pressure. Moreover, it is found that the specific role of strain rate sensitivity on the instability strain depends on the form of the constitutive relation assumed.
Sequence and Structural Convergence of Broad and Potent HIV Antibodies That Mimic CD4 Binding
Authors: Scheid Johannes F. , Mouquet Hugo , Ueberheide Beatrix , Diskin Ron , Klein Florian , Oliveira Thiago Y. K. , Pietzsch John , Fenyo David , Abadir Alexander , Velinzon Klara , Hurley Arlene , Myung Sunnie , Boulad Farid , Poignard Pascal , Burton Dennis R. , Pereyra Florencia , Ho David D. , Walker Bruce D. , Seaman Michael S. , Bjorkman Pamela J. , Chait Brian T. , Nussenzweig Michel C.
Published: July 2011

Anti-HIV broadly neutralizing antibodies with similar specificities and modes of binding were found in multiple HIV-infected individuals.
A framework for engaging physicians in quality and safety
Authors: Taitz Jonathan M , Lee Thomas H , Sequist Thomas D
Published: July 2011

Background

Physicians should be engaged in quality-improvement activities to make the systems in which they work safer and more reliable. However, many physicians are still unable to contribute to patient safety initiatives that lead to safer, high-quality care for their patients.

Objective

To survey 10 high-performing hospitals in the USA to determine how they engage their physicians in quality and safety.

Design

Qualitative study that used site visits and a semistructured 20-question interview.

Setting

Ten high-performing US hospitals were chosen from the 2010 US News and World Report Best Hospitals and the Leapfrog Group on Patient Safety.

Participants

Forty two interviews were conducted with forty-six quality leaders including CEO's, Chief Medical Officers, Vice Presidents for Quality and Safety and physicians.

Measurements

Site visits and in-person interviews were conducted during 2010–2011. The interviews were transcribed and coded using the constant comparative method for further analysis by the team.

Results

The authors developed a six-point framework for physician engagement in quality and safety as a constellation of the best strategies being used across the country. The framework consists of engaged leadership, a physician compact, appropriate compensation, realignment of financial incentives, data plus enablers and promotion.

Limitation

The qualitative design and the small number of hospitals surveyed mean that the results may not be generalisable.

Conclusion

There remain many ongoing barriers to physician engagement in quality and safety. Some high-performing hospitals in the USA have made significant improvements in engaging their physicians in quality and safety. The proposed framework can assist organisations in the development of strategies to engage physicians in quality-and-safety activities.
The Penumbra Stroke System: a technical review
Authors: Yoo Albert J , Frei Don , Tateshima Satoshi , Turk Aquilla S , Hui Ferdinand K , Brook Allan L , Heck Don V , Hirsch Joshua A
Published: July 2011

Major ischemic strokes secondary to proximal artery occlusions are responsible for significant morbidity and mortality. Owing to extensive clot burden, these strokes are poorly responsive to intravenous tissue plasminogen activator. The introduction of endovascular therapy, particularly mechanical devices, has resulted in markedly improved recanalization rates of large vessel occlusions. With increasing experience with the Penumbra Stroke System and the 054 reperfusion catheter, there has been further improvement in TIMI 2 and 3 revascularization rates with faster times to vessel opening. The aim of this technical review is to convey various tips and tricks learnt from this experience.
Prescribing errors in hospital inpatients: a three-centre study of their prevalence, types and causes
Authors: Franklin Bryony Dean , Reynolds Matthew , Shebl Nada Atef , Burnett Susan , Jacklin Ann
Published: July 2011

Aim

To compare the prevalence and causes of prescribing errors in newly written medication orders and how quickly they were rectified, in three NHS organisations.

Methods

Errors in newly written inpatient and discharge medication orders were recorded in Spring/Summer 2009 by ward pharmacists on medical admissions and surgical wards, as well as the number of erroneous doses administered (or omitted) before errors were corrected. Logistic regression analysis was used to explore the effects of ward (nested within organisation) and clinical specialty, and whether the pharmacist had checked the patient’s medication history during data collection. Causes were explored using semistructured interviews with key informants.

Results

Overall, 1025 prescribing errors were identified in 974 of 6605 medication orders (14.7%, 95% confidence interval (CI) 13.8% to 15.6%). A mean of 0.9 doses were administered (or omitted) before each error was corrected (range 0–11), with differences between specialties and organisations. The error rate on medical admissions wards (16.3%) was significantly higher than that on surgical wards (12.2%), but this was accounted for by the higher proportion of prescribing being on admission, where omission of patients' usual medication was often identified. There were significant differences among wards (and organisations). Contributing factors included lack of feedback on errors, poor documentation and communication of prescribing decisions, and lack of information about patients' medication histories from primary care.

Conclusions

There were variations among wards, organisations and specialties in error rates and how quickly they were rectified. Exploring reasons for differences between organisations may be useful in identifying best practice and potential solutions.
Role of climate and invasive species in structuring trout distributions in the interior Columbia River Basin, USA
Authors: Wenger Seth J. , Isaak Daniel J. , Dunham Jason B. , Fausch Kurt D. , Luce Charles H. , Neville Helen M. , Rieman Bruce E. , Young Michael K. , Nagel David E. , Horan Dona L. , Chandler Gwynne L.
Published: July 2011

Recent and projected climate warming trends have prompted interest in impacts on coldwater fishes. We examined the role of climate (temperature and flow regime) relative to geomorphology and land use in determining the observed distributions of three trout species in the interior Columbia River Basin, USA. We considered two native species, cutthroat trout ( Oncorhynchus clarkii ) and bull trout ( Salvelinus confluentus ), as well as nonnative brook trout ( Salvelinus fontinalis ). We also examined the response of the native species to the presence of brook trout. Analyses were conducted using multilevel logistic regression applied to a geographically broad database of 4165 fish surveys. The results indicated that bull trout distributions were strongly related to climatic factors, and more weakly related to the presence of brook trout and geomorphic variables. Cutthroat trout distributions were weakly related to climate but strongly related to the presence of brook trout. Brook trout distributions were related to both climate and geomorphic variables, including proximity to unconfined valley bottoms. We conclude that brook trout and bull trout are likely to be adversely affected by climate warming, whereas cutthroat trout may be less sensitive. The results illustrate the importance of considering species interactions and flow regime alongside temperature in understanding climate effects on fish.
Relative importance of size-based competitive ability and degree of niche overlap in inter-cohort competition of Atlantic salmon (Salmo salar) juveniles
Authors: Einum Sigurd , Kvingedal Eli
Published: July 2011

The competitive effect of older cohorts on younger cohorts may strengthen with increasing size differences owing to increasing differences in competitive abilities. Alternatively, it may weaken owing to increasing partitioning of resources as a result of ontogenetic niche shifts. Here, we test this by creating spatial variation in densities of one size class of overyearling Atlantic salmon ( Salmo salar ) and assess the effects on two size classes of young-of-the-year (YOY). The positive relationship between growth of overyearlings and final body size of YOY (a proxy for their growth) was steeper for the larger size class of YOY than for the smaller size class, which would be expected if the degree of niche overlap between two cohorts depended on their size difference. The negative relationship between overyearling density and YOY body size was also steeper for the larger size class (at least for body mass), suggesting that effects of body size differences on relative competitive abilities appear to be of less importance than the effects on degree of niche overlap. YOY should thus experience relatively less competition from older cohorts in rapidly growing populations, and this may also apply to many other fish species with ontogenetic niche shifts.
Effects of flow fluctuations on habitat use and survival of age-0 rainbow trout (Oncorhynchus mykiss) in a large, regulated river1This article is a companion to Korman et al. 2011, published this issue.
Authors: Korman Josh , Walters Carl , Martell S.J.D. , Pine W.E. , Dutterer Andrew
Published: July 2011

We evaluated effects of reduced hourly variation in flow from Glen Canyon Dam on survival of age-0 rainbow trout ( Oncorhynchus mykiss ) in the Colorado River, Arizona, USA, based on monthly abundance estimates. The proportion of the age-0 population in low-angle shorelines, which are potentially more sensitive to flow variability, declined from 70% in June to 20% in November as fish grew and made an ontogenetic habitat shift to deeper habitat. Average daily instantaneous mortality between August and September was 0.008 units lower in years when there was no change in the minimum flow compared with years when there was a sudden 50% reduction in the minimum flow. However, mortality was 0.006 units higher during the fall when there was no hourly variation in flow compared with years when flows fluctuated. As a result of these opposing patterns, 3-month age-0 survival across steady (0.31) and unsteady (0.28) flow regimes were very similar. While additional replication is required to strengthen inferences about effects of steadier flows, we demonstrate the utility of early life history monitoring for evaluating effects of flow management on fish populations in regulated rivers.
Describing population dynamics for early life stages of rainbow trout (Oncorhynchus mykiss) using a stock synthesis model1This article is a companion to Korman et al. 2011, published this issue.
Authors: Korman Josh , Martell S.J.D. , Walters Carl
Published: July 2011

A stock synthesis model was used to assess effects of experimental flows on early life stages of nonnative rainbow trout ( Oncorhynchus mykiss ) in the Colorado River below Glen Canyon Dam (Arizona, USA). The model estimated time-varying survival rates while correcting for entry of new recruits to the age-0 population and changes in vulnerability to capture associated with growth and ontogenetic habitat shifts. A controlled flood, designed in part to enhance native fish habitat, led to an 11-fold increase in early survival rates (fertilization to ~1 month from emergence) of weekly cohorts of trout fertilized after the flood. Effects of increased flow fluctuations during incubation, designed to reduce trout abundance, were not apparent. Age-0 mortality between August and September was over twofold higher in years when there was a 50% reduction in the minimum flow compared with years when flow was stable. There was strong support for models that simulated an ontogenetic shift to deeper habitat in four of five study years. The integration of detailed field information in a stock synthesis model to describe early life history dynamics is a valuable approach that can be applied in a wide range of systems.
CALCULATION OF BULK VISCOSITY OF QCD AT ZERO TEMPERATURE AND FINITE CHEMICAL POTENTIAL
Authors: WANG MING-MIN , JIANG YU , WANG BIN , SUN WEI-MIN , ZONG HONG-SHI
Published: July 2011

In this paper, based on Kubo's formula and the QCD low energy theorem, we propose a direct formula for calculating the bulk viscosity of QCD at finite chemical potential μ and zero temperature. According to this formula, the bulk viscosity at finite μ is totally determined by the dressed quark propagator at finite μ. We then use a dynamical, confining Dyson–Schwinger equation model of QCD to calculate the bulk viscosity at finite μ. It is found that no sharp peak behavior of the bulk viscosity at finite μ is observed, which is quite different from that of the bulk viscosity at finite temperature.
PSEUDODUALITY IN SUPERSYMMETRIC SIGMA MODELS ON SYMMETRIC SPACES
Authors: SARISAMAN MUSTAFA
Published: July 2011

We discuss the target space pseudoduality in supersymmetric sigma models on symmetric spaces using two different methods, orthonormal coframe and component expansion. These two methods yield similar results to the classical cases with the exception that commuting bracket relations in classical case turn out to be anticommuting ones because of the appearance of Grassmann numbers. In component expansion method it is understood that constraint relations in case of non-mixing pseudoduality are the remnants of mixing pseudoduality. Once mixing terms are included in the pseudoduality relations, the constraint relations disappear.
ELECTRONIC AND MAGNETIC STRUCTURE OF THE HIGH PRESSURE PHASE OF Li2CuO2
Authors: LI ZHI , TSE JOHN S. , YOU SHUJIE , JIN C. Q. , IITAKA TOSHIAKI
Published: July 2011

The magnetic and electronic structure of monoclinic phase Li 2 CuO 2 under high pressure is studied by first principle with GGA+U calculations. It is shown that the C-type antiferromagnetic state of the ambient structure is maintained in the monoclinic high pressure phase. This is due to the preservation of the ferromagnetic CuO 2 chains in the structure. It is expected that the weak interchain antiferromagnetic interaction can easily disrupt by finite temperature, and the magnetocrystalline anisotropy in this insulator is extremely weak.
Online Learning Indicators
Authors: Burk Erlan
Published: July 2011

Presented are 11 issues that indicators of necessary course design. The Absence of one or more indicators in an online class can create difficulty for students and, in turn, cause learning to suffer. The result is an unsuccessful online learning experience.
Book Review: 'Game Frame' by Aaron Dignan
Authors: Silvers Aaron
Published: July 2011

What if your business could be a game? If you've ever asked yourself this question, you should be reading Aaron Dignan's "Game Frame." Dignan takes a practical focus on behavioral games and presents common-sense reasons why we need to start focusing more on games.
The networking philosopher's problem
Authors: Rexford Jennifer
Published: July 2011

While computer networking is an exciting research field, we are far from having a clear understanding of the core concepts and questions that define our discipline. This position paper, a summary of a talk I gave at the CoNext'10 Student Workshop, captures my current frustrations and hopes about the field.
Message from the workshop on the future of social networking
Authors: Yoneki Eiko , Crowcroft Jon , Lio' Pietro , Walton Neil , Vojnovic Milan , Whitaker Roger
Published: July 2011

Electronic social networks are a relatively new pervasive phenomenon that has changed the way in which we communicate and interact. They are now supporting new applications, leading to new trends and posing new challenges. The workshop titled "Future of Social Networking: Experts from Industry and Academia" took place in Cambridge on November 18, 2010 to expose how the future of social networking may develop and be exploited in new technologies and systems. We provide a summary of this event and some observations on the key outcomes.