bluuebunny/crossref_metadata_2025 huggingface dataset:
Network patterns and social architecture in Massively Multiplayer Online Games: Mapping the social world of EverQuest II
Authors: Shen Cuihua
Published: June 2013

This paper presents a critical examination of the social interactions among Massively Multiplayer Online Game (MMOG) participants. Drawing on the conceptual framework of “third places” and prior empirical studies, this study aims to map the social world of a popular MMOG, EverQuest II, primarily relying on unobtrusively collected behavioral server logs. Analysis of network patterns revealed that the social architecture of the world was quite effective in shaping the structure of interaction, as the involvement in various social networks was influenced by class choice and character level. However, sociability among players was quite diffuse, with a sizable number of players opting to play solo despite the built-in mechanisms that encourage collaborative play.
Damage localization map using electromechanical impedance spectrums and inverse distance weighting interpolation: Experimental validation on thin composite structures
Authors: Cherrier Olivier , Selva Pierre , Pommier-Budinger Valérie , Lachaud Frédéric , Morlier Joseph
Published: June 2013

Piezoelectric sensors are widely used for structure health monitoring technique. In particular, electromechanical impedance techniques give simple and low-cost solutions for detecting damage in composite structures. The purpose of the method proposed in this article is to generate a damage localization map based on both indicators computed from electromechanical impedance spectrums and inverse distance weighting interpolation. The weights for the interpolation have a physical sense and are computed according to an exponential law of the measured attenuation of acoustic waves. One of the main advantages of the method, so-called data-driven method, is that only experimental data are used as inputs for our algorithm. It does not rely on any model. The proposed method has been validated on both one-dimensional and two-dimensional composite structures.
A computational framework for life-cycle management of wind turbines incorporating structural health monitoring
Authors: Smarsly Kay , Hartmann Dietrich , Law Kincho H
Published: June 2013

The integration of structural health monitoring into life-cycle management strategies can help facilitating a reliable operation of wind turbines and reducing the life-cycle costs significantly. This article presents a life-cycle management framework for online monitoring and performance assessment of wind turbines, enabling optimum maintenance and inspection planning at minimum associated life-cycle costs. Incorporating continuously updated monitoring data (i.e. structural, environmental, and operational data), the framework allows capturing and understanding the actual wind turbine condition and, hence, reduces uncertainty in structural responses as well as load effects acting on the structure. As will be shown in this article, the framework integrates a variety of heterogeneous hardware and software components, including sensors and data acquisition units, server systems, Internet-enabled user interfaces as well as finite element models for system identification, and a multiagent system for self-detecting sensor malfunctions. To validate its capabilities and to demonstrate its practicability, the framework is deployed for continuous monitoring and life-cycle management of a 500-kW wind turbine. Remote life-cycle analyses of the monitored wind turbine are conducted, and case studies are presented investigating both the structural performance and the operational efficiency of the wind turbine.
Cause of a rare acute renal insufficiency: Rupture aortocaval fistula
Authors: Simsek Erdal , Caliskan Aytac , Tutun Ufuk , Sahin Serpil
Published: June 2013

Introduction

Abdominal aortic aneurysms can be complicated by some conditions and aortocaval fistula is one of them. Aortocaval fistula is an unusual entity.

Case Report

A male patient was admitted to the hospital for abdominal pain and leg oedema of three days duration. In addition, severe anuria was also noted. We determined a fistula from the right lateral wall of aneurysm to the distal of vena cava inferior. The aortocaval fistula was closed with pledged-reinforced 4/0 polypropylene suture in the aneurysmal wall. At the postoperative 10th day, he was discharged with normal renal function.

Discussion

After a long-term untreated fistula, right-sided heart failure, acute renal and hepatic insufficiency, deep vein thrombosis and pulmonary thrombo-embolism can be seen in these patients. Increased venous pressure should be the reason for decreased arterial flow results in renal insufficiency. Emergency intervention in these patients saves the patient’s life as well as prevents irreversible organ failure.
Data collection in cancer clinical trials: Too much of a good thing?
Authors: O’Leary Erin , Seow Hsien , Julian Jim , Levine Mark , Pond Gregory R
Published: June 2013

Background

Substantial staff time and costs are incurred in the collection of data for cancer clinical trials. Anecdotal experience suggests that much of these data are never used in the analysis or reporting of a trial.

Purpose

To quantify data items collected in cancer clinical trials and calculate what percentage is used in subsequent published manuscripts.

Methods

Cancer clinical trials completed by the Ontario Clinical Oncology Group (OCOG) between 2003 and 2012 and the corresponding primary outcome publication were identified. The number of data items collected on each trial’s case report form (CRF) was counted and sorted into 18 categories including eligibility, baseline characteristics, medical history, toxicity, and recurrence. The data items were then counted within the corresponding published manuscripts to determine percent of data used overall and within each section.

Results

In all, 8 trials, with 9 corresponding publications, were evaluated. The CRF analysis revealed that the total collected items per subject ranged from 186 to 1035 per trial with a median of 599. Across all the publications, a median of 96 data items (18%) were reported in each manuscript, ranging from 11% to 27% per trial. In 8 of the 18 categories, 4% or less of collected data items were used.

Limitations

The number of trials reviewed is small and were conducted from a single clinical trial coordinating centre. The main outcome of the number of data items used in the published manuscript is a surrogate for trial information considered valuable by investigators. Some data may be deemed important by investigators but not included in manuscripts.

Conclusions

In this analysis of publications from 8 clinical trials, a small amount of data collected was ultimately used in peer-reviewed journal manuscripts. A large amount of data collected in cancer trials appears to go unused and could be omitted from CRFs, thus simplifying data collection and improving trial efficiency.
The impact of early endoscopic lesions on the clinical course of patients following ileocolonic resection for Crohn’s disease: A 5‐year prospective cohort study
Authors: Yamamoto Takayuki , Bamba Takuya , Umegae Satoru , Matsumoto Koichi
Published: June 2013

Background

Early endoscopic lesions following resection for Crohn’s disease (CD) are often observed. Currently, the relationship between this endoscopic observation and subsequent occurrence of CD lesions or recurrence is not understood well, but should be valuable in the context of predicting CD course. This prospective study was to investigate the impact of early endoscopic lesions on future clinical recurrence rates following ileocolonic resection for CD.

Methods

Forty patients who had maintained clinical remission, CD activity index (CDAI) <150 with mesalazine during 6 months after ileocolonic resection for CD were included. At 6 months after surgery, ileocolonoscopy was performed, and the endoscopic activity score at the proximal site of the anastomosis was determined according to Rutgeerts. All patients were regularly monitored for 5 years, and clinical recurrence was defined as CDAI ≥ 150. Corticosteroids, immunosuppressants, or biological agents were not given unless there was clinical recurrence.

Results

At 6 months after surgery, the endoscopic scores were i0 or i1 in 27 patients, i2 in seven patients, i3 in four patients, and i4 in two patients. During the following 5 years, the clinical recurrence occurred in three (11%) patients with endoscopic score of i0 or i1, four (57%) patients with i2 score, three (75%) patients with i3 score, and two (100%) patients with i4 score, showing a significant positive correlation (p  = 0.001) between the endoscopic severity of the proximal site of the anastomosis at 6 months after surgery and the clinical recurrence rate during the following 5 years.

Conclusions

The assessment of endoscopic lesions at the proximal site of the anastomosis appeared to be valuable for predicting subsequent clinical recurrence after ileocolonic resection for CD. Further studies in larger cohorts of patients are warranted to strengthen our findings.
Loci of Causality and Orientation in Occupational and Educational Choices
Authors: Friberg Kalervo
Published: June 2013

A student self-determination profile of occupational and educational choices was examined through the concepts of Locus of Causality and Locus of Orientation. Research questions associated with respondents’ certainty of occupation and orientation to vocational education were answered. The tested hypotheses were as follows: (a) Independence, initiative, self-guidance, choice of discussion forums, and gender are related to certainty of future occupation choice and choice of vocational education; (b) certainty of occupation relates to choosing vocational education; (c) negatively biased media lessens interest in vocational education; and (d) vocational education choices are related to gender. A survey of ninth-grade students in Finnish comprehensive school was conducted after implementation of a work-orientation program defined in the national comprehensive school curriculum. At the local school system level, 649 subjects of the mean ages of 16.0 years participated in an Internet survey in two school districts in southwestern Finland in 2008. The variables were inserted in Linear Multiple Regression Analysis in IBM SPSS. The means of vocational school choice and certainty of occupation, and vocational school choice and negative media image were compared in SPSS means. An independent-samples t test for vocational school choice and sex was conducted. Statistically significant regression models of loci of orientation and locus of causality were found. The more the respondents were certain of their occupation choice, the more they expressed their secondary education orientation to be vocational school. When students discussed their choices less at home, their orientation to vocational education weakened. A negative media image was not associated with vocational school choice in this data. The measured means for girls’ and boys’ orientations to vocational school did not show statistically significant differences.
Knowledge, attitudes, and behaviors regarding HIV among first time attenders of voluntary counseling and testing services in Italy
Authors: Di Giuseppe Gabriella , Sessa Alessandra , Mollo Silvana , Corbisiero Natascia , Angelillo Italo F ,   The Collaborative Working Group
Published: June 2013

Background

This study assess knowledge, attitudes, and practices regarding Human Immunodeficiency Virus (HIV) testing and counseling services and the predictor characteristics of these outcomes among individuals who presented for the first time to Voluntary Counseling and Testing (VCT) public services.

Methods

A sample of 244 subjects in the geographic area of Naples (Italy) received a self-administered anonymous questionnaire about socio-demographic characteristics, knowledge, attitudes relating to HIV infection, and practices relating to access to VCT service.

Results

Only 25% correctly identified the main modes of transmission and the main preventative measures of HIV and this knowledge was significantly higher in who had had more than one sexual partner and have not always used a condom during the intercourse in the last year, in those who have received information about HIV/AIDS through physician, and in those who have received middle school or lower educational level. The perceived risk of contracting HIV/AIDS was significantly higher in respondents of lower age, in those who perceived a better personal health status, and in those unmarried. Only 20.9% reported that they had received the HIV test and males and those who visited a physician or participated in preventive activities about HIV/AIDS were significantly more likely to have had an HIV test.

Conclusions

This study supports the need to disseminate information and interventions to this population.
Comparison of Xpert MTB/RIF with ProbeTec ET DTB and COBAS TaqMan MTB for direct detection of M. tuberculosis complex in respiratory specimens
Authors: Antonenka Uladzimir , Hofmann-Thiel Sabine , Turaev Laziz , Esenalieva Ainura , Abdulloeva Mokhonim , Sahalchyk Evgeni , Alnour Tarig , Hoffmann Harald
Published: June 2013

Background

Nucleic acid amplification assays allow for the rapid and accurate detection of Mycobacterium tuberculosis (MTB) directly in clinical specimens thereby facilitating diagnosis of tuberculosis (TB). With the fully automated Xpert MTB/RIF system (Cepheid) an innovative solution of TB diagnostics has been launched. We performed a direct head-to-head comparison of Xpert MTB/RIF with two widely used commercial assays, ProbeTec ET DTB (DTB) (Becton-Dickinson) and COBAS TaqMan MTB (CTM-MTB) (Roche).

Methods

121 pre-characterized respiratory specimens (68 culture-positive for MTB complex, 24 culture-positive for non-tuberculous mycobacteria and 29 culture-negative) taken from our frozen specimen bank were tested for the presence of MTB complex by the three assays.

Results

Among culture-positive samples (n = 68), overall sensitivity for detection of MTB complex was 74.6%, 73.8%, and 79.1% for Xpert MTB/RIF, CTM-MTB, and DTB, respectively. Within the subgroup of smear-negative TB samples (n = 51) sensitivity was 68% for Xpert MTB/RIF and CTM-MTB and 72% for DTB. Among smear-positive TB samples (n = 17), all (100%) were detected by DTB and 94.1% and 93.3% by Xpert MTB/RIF and CTM-MTB, respectively. Specificity was best for CTM-MTB (100%) and lowest for Xpert MTB/RIF (96.2%) due to misidentification of two NTM samples as MTB complex. CTM-MTB yielded the highest rate of invalid results (4.1%) (0.8% by Xpert MTB/RIF and DTB, respectively).

Conclusions

The direct comparison of Xpert MTB/RIF with CTM-MTB and DTB yielded similar overall performance data. Whereas DTB was slightly superior to Xpert MTB/RIF in terms of sensitivity, at least in the sample collection tested here, CTM-MTB performed best in terms of specificity.
Pharmacogenetic predictors of nausea and vomiting of pregnancy severity and response to antiemetic therapy: a pilot study
Authors: Lehmann Amalia S , Renbarger Jamie L , McCormick Catherine L , Topletz Ariel R , Rouse Carrie , Haas David M
Published: June 2013

Background

Nausea and vomiting of pregnancy (NVP) is a common condition. The objective of this study was to evaluate the association between response to antiemetics in the treatment of NVP and genetic polymorphisms in the serotonin receptor subunit genes HTR3A and HTR3B.

Methods

Pregnant women ≥18 years of age with NVP starting antiemetic therapy with promethazine, prochlorperazine, metoclopramide, or ondansetron at ≤ 16 weeks gestational age were eligible. The study recruited 29 women with complete data and sampling who returned for their one week follow-up and were genotyped for HTR3A and HTR3B polymorphisms. Severity of NVP was captured (using Pregnancy Unique Quantification of Emesis (PUQE) and Quality of Life (QOL) tools) upon enrollment and after one week of antiemetic therapy. These measures were correlated with pharmacogenetic variability.

Results

Subjects with genotype associated with high serotonin affinity of the 5-HT3B receptor (rs1176744, CC) required more antiemetic medications (p < 0.001) than other subjects. Those with genotypes associated with increased expression of the 5-HT3A receptor subunit (rs1062613, CT or TT) had worse final PUQE scores (p = 0.01) than other subjects while rs3782025 variants carriers had significantly better initial (p = 0.02) and final (p = 0.02) PUQE scores than other subjects.

Conclusions

HTR3B and HTR3A gene variants may contribute to variability in response to antiemetic therapy for NVP.
Prevalence of metabolic syndrome among urban community residents in China
Authors: Wang Guang-Rong , Li Li , Pan Yi-Hui , Tian Guo-Dong , Lin Wan-Long , Li Zhe , Chen Zheng-Yi , Gong You-Long , Kikano George E , Stange Kurt C , Ni Ke-Liang , Berger Nathan A
Published: June 2013

Background

Metabolic risk factors and abnormalities such as obesity and hypertension are rapidly rising among the Chinese population following China’s tremendous economic growth and widespread westernization of lifestyle in recent decades. Limited information is available about the current burden of metabolic syndrome (MetS) in China.

Methods

We analyzed data on metabolic risk factors among 22,457 adults aged ≥ 32 years participating in the “Zhabei Health 2020” survey (2009–2010), a cross-sectional study of a representative sample of community residents in Zhabei District. We defined MetS using Chinese-specific cut-off points for central obesity according to consensus criteria recently endorsed by several international and national organizations in defining MetS in different populations worldwide. We used a multiple logistic regression model to assess the associations of potential risk factors with MetS.

Results

The unadjusted prevalence of the MetS was 35.1% for men and 32.5% for women according to the consensus criteria for Chinese. The prevalence increased progressively from 12.1% among participants aged 32–45 years to 45.4% among those aged ≥ 75 years. Age, smoking, family history of diabetes, and education are significantly associated with risk of MetS.

Conclusions

The MetS is highly prevalent and has reached epidemic proportion in Chinese urban adult community residents.
The effects of 8 weeks of whey or rice protein supplementation on body composition and exercise performance
Authors: Joy Jordan M , Lowery Ryan P , Wilson Jacob M , Purpura Martin , De Souza Eduardo O , Wilson Stephanie MC , Kalman Douglas S , Dudeck Joshua E , Jäger Ralf
Published: June 2013

Background

Consumption of moderate amounts of animal-derived protein has been shown to differently influence skeletal muscle hypertrophy during resistance training when compared with nitrogenous and isoenergetic amounts of plant-based protein administered in small to moderate doses. Therefore, the purpose of the study was to determine if the post-exercise consumption of rice protein isolate could increase recovery and elicit adequate changes in body composition compared to equally dosed whey protein isolate if given in large, isocaloric doses.

Methods

24 college-aged, resistance trained males were recruited for this study. Subjects were randomly and equally divided into two groups, either consuming 48 g of rice or whey protein isolate (isocaloric and isonitrogenous) on training days. Subjects trained 3 days per week for 8 weeks as a part of a daily undulating periodized resistance-training program. The rice and whey protein supplements were consumed immediately following exercise. Ratings of perceived recovery, soreness, and readiness to train were recorded prior to and following the first training session. Ultrasonography determined muscle thickness, dual emission x-ray absorptiometry determined body composition, and bench press and leg press for upper and lower body strength were recorded during weeks 0, 4, and 8. An ANOVA model was used to measure group, time, and group by time interactions. If any main effects were observed, a Tukey post-hoc was employed to locate where differences occurred.

Results

No detectable differences were present in psychometric scores of perceived recovery, soreness, or readiness to train (p > 0.05). Significant time effects were observed in which lean body mass, muscle mass, strength and power all increased and fat mass decreased; however, no condition by time interactions were observed (p > 0.05).

Conclusion

Both whey and rice protein isolate administration post resistance exercise improved indices of body composition and exercise performance; however, there were no differences between the two groups.
Daily consumption of a synbiotic yogurt decreases energy intake but does not improve gastrointestinal transit time: a double-blind, randomized, crossover study in healthy adults
Authors: Tulk Hilary M F , Blonski Diane C , Murch Lauren A , Duncan Alison M , Wright Amanda J
Published: June 2013

Objective

Probiotic and synbiotic products are widely marketed to healthy individuals, although potential benefits for these individuals are rarely studied. This study investigated the effect of daily consumption of a synbiotic yogurt on gastrointestinal (GI) function in a sample of healthy adults.

Subjects/Methods

In a randomized crossover double-blind study, 65 healthy adults consumed 200 g/day of yogurt with (synbiotic) or without (control) added probiotics (Bifidobacterium lactisBb12,Lactobacillus acidophilusLa5, Lactobacillus caseiCRL431) and 4 g inulin for two 15-day treatment periods, each preceded by a 6-week washout period. GI transit time (GTT), duration of colour (DOC), GI symptoms and dietary intake were assessed and analyzed using repeated measures ANOVA, including PRE-treatment GTT as a covariate. Participants were grouped as short GTT (STT, n = 50, ≤32.7 h) or long GTT (LTT, n = 15, >32.7 h) based on their PRE-treatment GTT assessment.

Results

POST-treatment GTT and DOC were not different between synbiotic and control, and did not change from PRE-treatment, within the STT or LTT groups. There were no changes in GI symptom ratings, indicating that both yogurts were well tolerated. In STT, energy, fat and protein intakes were decreased from baseline with synbiotic (p = 0.055, p = 0.059 and p = 0.005, respectively) and dietary fibre intake was higher POST-treatment with synbiotic versus control (p = 0.0002). In LTT, decreases in energy and fat intakes with synbiotic were not significant (p = 0.14 and p = 0.18, respectively) and there were no differences in dietary fibre intake.

Conclusion

Consuming 200 g/day of synbiotic yogurt did not significantly alter GTT in healthy adults, but was well tolerated and helped to reduce overall energy intake.
Structural, optical, and magnetic studies of manganese-doped zinc oxide hierarchical microspheres by self-assembly of nanoparticles
Authors: Hao Yao-Ming , Lou Shi-Yun , Zhou Shao-Min , Yuan Rui-Jian , Zhu Gong-Yu , Li Ning
Published: June 2013

In this study, a series of manganese [Mn]-doped zinc oxide [ZnO] hierarchical microspheres [HMSs] are prepared by hydrothermal method only using zinc acetate and manganese acetate as precursors and ethylene glycol as solvent. X-ray diffraction indicates that all of the as-obtained samples including the highest Mn (7 mol%) in the crystal lattice of ZnO have a pure phase (hexagonal wurtzite structure). A broad Raman spectrum from as-synthesized doping samples ranges from 500 to 600 cm-1, revealing the successful doping of paramagnetic Mn2+ ions in the host ZnO. Optical absorption analysis of the samples exhibits a blueshift in the absorption band edge with increasing dopant concentration, and corresponding photoluminescence spectra show that Mn doping suppresses both near-band edge UV emission and defect-related blue emission. In particular, magnetic measurements confirm robust room-temperature ferromagnetic behavior with a high Curie temperature exceeding 400 K, signifying that the as-formed Mn-doped ZnO HMSs will have immense potential in spintronic devices and spin-based electronic technologies.
Fabrication of a form- and size-variable microcellular-polymer-stabilized metal nanocomposite using supercritical foaming and impregnation for catalytic hydrogenation
Authors: Liao Weisheng , Wu Ben-Zen , Nian Hungchi , Chen Hsiang-Yu , Yu Jya-Jyun , Chiu KongHwa
Published: June 2013

This article presents the fabrication of size-controllable and shape-flexible microcellular high-density polyethylene-stabilized palladium nanoparticles (Pd/m-HDPE) using supercritical foaming, followed by supercritical impregnation. These nanomaterials are investigated for use as heterogeneous hydrogenation catalysts of biphenyls in supercritical carbon dioxide with no significant surface and inner mass transfer resistance. The morphology of the Pd/m-HDPE is examined using scanning electron microscopy images of the pores inside Pd/m-HDPE catalysts and transmission electron microscopy images of the Pd particles confined in an HDPE structure. This nanocomposite simplifies industrial design and operation. These Pd/m-HDPE catalysts can be recycled easily and reused without complex recovery and cleaning procedures.
Nonlinear vibration behavior of graphene resonators and their applications in sensitive mass detection
Authors: Dai Mai Duc , Kim Chang-Wan , Eom Kilho
Published: June 2013

Graphene has received significant attention due to its excellent mechanical properties, which has resulted in the emergence of graphene-based nano-electro-mechanical system such as nanoresonators. The nonlinear vibration of a graphene resonator and its application to mass sensing (based on nonlinear oscillation) have been poorly studied, although a graphene resonator is able to easily reach the nonlinear vibration. In this work, we have studied the nonlinear vibration of a graphene resonator driven by a geometric nonlinear effect due to an edge-clamped boundary condition using a continuum elastic model such as a plate model. We have shown that an in-plane tension can play a role in modulating the nonlinearity of a resonance for a graphene. It has been found that the detection sensitivity of a graphene resonator can be improved by using nonlinear vibration induced by an actuation force-driven geometric nonlinear effect. It is also shown that an in-plane tension can control the detection sensitivity of a graphene resonator that operates both harmonic and nonlinear oscillation regimes. Our study suggests the design principles of a graphene resonator as a mass sensor for developing a novel detection scheme using graphene-based nonlinear oscillators.
Charge transport along proton wires
Authors: Karahka Markus Leopold , Kreuzer Hans Jürgen
Published: June 2013

Using density functional theory we look at the quantum mechanics of charge transport along water wires both with free ends and donor/acceptor terminated. With the intermediate geometries in the DFT iterations we can follow the charge transfer mechanism and also construct the energy landscape explicitly. It shows activation barriers when a proton is transferred from one water molecule to the next. This, together with snapshots of intermediate geometries, leads to a justification and further elucidation of the Grotthuss mechanism and the Bjerrum effect. The charge transfer times and the conductivity of the proton wire are obtained in agreement with experimental results.
3D hand tracking using Kalman filter in depth space
Authors: Park Sangheon , Yu Sunjin , Kim Joongrock , Kim Sungjin , Lee Sangyoun
Published: June 2013

Hand gestures are an important type of natural language used in many research areas such as human-computer interaction and computer vision. Hand gestures recognition requires the prior determination of the hand position through detection and tracking. One of the most efficient strategies for hand tracking is to use 2D visual information such as color and shape. However, visual-sensor-based hand tracking methods are very sensitive when tracking is performed under variable light conditions. Also, as hand movements are made in 3D space, the recognition performance of hand gestures using 2D information is inherently limited. In this article, we propose a novel real-time 3D hand tracking method in depth space using a 3D depth sensor and employing Kalman filter. We detect hand candidates using motion clusters and predefined wave motion, and track hand locations using Kalman filter. To verify the effectiveness of the proposed method, we compare the performance of the proposed method with the visual-based method. Experimental results show that the performance of the proposed method out performs visual-based method.
Macondo crude oil from the Deepwater Horizon oil spill disrupts specific developmental processes during zebrafish embryogenesis
Authors: de Soysa T Yvanka , Ulrich Allison , Friedrich Timo , Pite Danielle , Compton Shannon L , Ok Deborah , Bernardos Rebecca L , Downes Gerald B , Hsieh Shizuka , Stein Rachael , Lagdameo M Caterina , Halvorsen Katherine , Kesich Lydia-Rose , Barresi Michael JF
Published: June 2013

Background

The Deepwater Horizon disaster was the largest marine oil spill in history, and total vertical exposure of oil to the water column suggests it could impact an enormous diversity of ecosystems. The most vulnerable organisms are those encountering these pollutants during their early life stages. Water-soluble components of crude oil and specific polycyclic aromatic hydrocarbons have been shown to cause defects in cardiovascular and craniofacial development in a variety of teleost species, but the developmental origins of these defects have yet to be determined. We have adopted zebrafish, Danio rerio, as a model to test whether water accumulated fractions (WAF) of the Deepwater Horizon oil could impact specific embryonic developmental processes. While not a native species to the Gulf waters, the developmental biology of zebrafish has been well characterized and makes it a powerful model system to reveal the cellular and molecular mechanisms behind Macondo crude toxicity.

Results

WAF of Macondo crude oil sampled during the oil spill was used to treat zebrafish throughout embryonic and larval development. Our results indicate that the Macondo crude oil causes a variety of significant defects in zebrafish embryogenesis, but these defects have specific developmental origins. WAF treatments caused defects in craniofacial development and circulatory function similar to previous reports, but we extend these results to show they are likely derived from an earlier defect in neural crest cell development. Moreover, we demonstrate that exposure to WAFs causes a variety of novel deformations in specific developmental processes, including programmed cell death, locomotor behavior, sensory and motor axon pathfinding, somitogenesis and muscle patterning. Interestingly, the severity of cell death and muscle phenotypes decreased over several months of repeated analysis, which was correlated with a rapid drop-off in the aromatic and alkane hydrocarbon components of the oil.

Conclusions

Whether these teratogenic effects are unique to the oil from the Deepwater Horizon oil spill or generalizable for most crude oil types remains to be determined. This work establishes a model for further investigation into the molecular mechanisms behind crude oil mediated deformations. In addition, due to the high conservation of genetic and cellular processes between zebrafish and other vertebrates, our work also provides a platform for more focused assessment of the impact that the Deepwater Horizon oil spill has had on the early life stages of native fish species in the Gulf of Mexico and the Atlantic Ocean.
Nutraceutical agents with anti-inflammatory properties prevent dietary saturated-fat induced disturbances in blood–brain barrier function in wild-type mice
Authors: Takechi Ryusuke , Pallebage-Gamarallage Menuka M , Lam Virginie , Giles Corey , Mamo John C
Published: June 2013

Background

Emerging evidence suggests that disturbances in the blood–brain barrier (BBB) may be pivotal to the pathogenesis and pathology of vascular-based neurodegenerative disorders. Studies suggest that heightened systemic and central inflammations are associated with BBB dysfunction. This study investigated the effect of the anti-inflammatory nutraceuticals garlic extract-aged (GEA), alpha lipoic acid (ALA), niacin, and nicotinamide (NA) in a murine dietary-induced model of BBB dysfunction.

Methods

C57BL/6 mice were fed a diet enriched in saturated fatty acids (SFA, 40% fat of total energy) for nine months to induce systemic inflammation and BBB disturbances. Nutraceutical treatment groups included the provision of either GEA, ALA, niacin or NA in the positive control SFA-group and in low-fat fed controls. Brain parenchymal extravasation of plasma derived immunoglobulin G (IgG) and large macromolecules (apolipoprotein (apo) B lipoproteins) measured by quantitative immunofluorescent microscopy, were used as markers of disturbed BBB integrity. Parenchymal glial fibrillar acidic protein (GFAP) and cyclooxygenase-2 (COX-2) were considered in the context of surrogate markers of neurovascular inflammation and oxidative stress. Total anti-oxidant status and glutathione reductase activity were determined in plasma.

Results

Brain parenchymal abundance of IgG and apoB lipoproteins was markedly exaggerated in mice maintained on the SFA diet concomitant with significantly increased GFAP and COX-2, and reduced systemic anti-oxidative status. The nutraceutical GEA, ALA, niacin, and NA completely prevented the SFA-induced disturbances of BBB and normalized the measures of neurovascular inflammation and oxidative stress.

Conclusions

The anti-inflammatory nutraceutical agents GEA, ALA, niacin, or NA are potent inhibitors of dietary fat-induced disturbances of BBB induced by systemic inflammations.
Skeletal muscle pathology of infantile Pompe disease during long-term enzyme replacement therapy
Authors: Prater Sean N , Patel Trusha T , Buckley Anne F , Mandel Hanna , Vlodavski Eugene , Banugaria Suhrad G , Feeney Erin J , Raben Nina , Kishnani Priya S
Published: June 2013

Background

Pompe disease is an autosomal recessive metabolic neuromuscular disorder caused by a deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA). It has long been believed that the underlying pathology leading to tissue damage is caused by the enlargement and rupture of glycogen-filled lysosomes. Recent studies have also implicated autophagy, an intracellular lysosome-dependent degradation system, in the disease pathogenesis. In this study, we characterize the long-term impact of enzyme replacement therapy (ERT) with recombinant human GAA (rhGAA) on lysosomal glycogen accumulation and autophagy in some of the oldest survivors with classic infantile Pompe disease (IPD).

Methods

Muscle biopsies from 8 [4 female, 4 male; 6 cross-reactive immunologic material (CRIM)-positive, 2 CRIM-negative] patients with a confirmed diagnosis of classic IPD were examined using standard histopathological approaches. In addition, muscle biopsies were evaluated by immunostaining for lysosomal marker (lysosomal-associated membrane protein-2; LAMP2), autophagosomal marker (microtubule-associated protein 1 light chain 3; LC3), and acid and alkaline ATPases. All patients received rhGAA by infusion at cumulative biweekly doses of 20–40 mg/kg.

Results

Median age at diagnosis of classic IPD was 3.4 months (range: 0 to 6.5 months; n = 8). At the time of muscle biopsy, the patients’ ages ranged from 1 to 103 months and ERT duration ranged from 0 (i.e., baseline, pre-ERT) to 96 months. The response to therapy varied considerably among the patients: some patients demonstrated motor gains while others experienced deterioration of motor function, either with or without a period of initial clinical benefit. Skeletal muscle pathology included fiber destruction, lysosomal vacuolation, and autophagic abnormalities (i.e., buildup), particularly in fibers with minimal lysosomal enlargement. Overall, the pathology reflected clinical status.

Conclusions

This is the first study to investigate the impact of rhGAA ERT on lysosomal glycogen accumulation and autophagic buildup in patients with classic IPD beyond 18 months of treatment. Our findings indicate that ERT does not fully halt or reverse the underlying skeletal muscle pathology in IPD. The best outcomes were observed in the two patients who began therapy early, namely at 0.5 and 1.1 months of age.
Sergentomyia schwetzi is not a competent vector for Leishmania donovani and other Leishmania species pathogenic to humans
Authors: Sadlova Jovana , Dvorak Vit , Seblova Veronika , Warburg Alon , Votypka Jan , Volf Petr
Published: June 2013

Background

Sand fly species of the genus Sergentomyia are proven vectors of reptilian Leishmania that are non-pathogenic to humans. However, a consideration of the role of Sergentomyia spp. in the circulation of mammalian leishmaniasis appears repeatedly in the literature and the possibility of Leishmania transmission to humans remains unclear. Here we studied the susceptibility of colonized Sergentomyia schwetzi to Leishmania donovani and two other Leishmania species pathogenic to humans: L. infantum and L. major.

Methods

Females of laboratory-reared S. schwetzi were infected by cultured Leishmania spp. by feeding through a chicken membrane, dissected at different time intervals post bloodmeal and examined by light microscopy for the abundance and location of infections.

Results

All three Leishmania species produced heavy late stage infections in Lutzomyia longipalpis or Phlebotomus duboscqi sand flies used as positive controls. In contrast, none of them completed their developmental cycle in Sergentomyia females; Leishmania promastigotes developed within the bloodmeal enclosed by the peritrophic matrix (PM) but were defecated together with the blood remnants, failing to establish a midgut infection. In S. schwetzi, the PM persisted significantly longer than in L. longipalpis and it was degraded almost simultaneously with defecation. Therefore, Leishmania transformation from procyclic to long nectomonad forms was delayed and parasites did not attach to the midgut epithelium.

Conclusions

Sergentomyia schwetzi is refractory to human Leishmania species and the data indicate that the crucial aspect of the refractoriness is the relative timing of defecation versus PM degradation.
Impacts of gambling problems on partners: partners’ interpretations
Authors: Holdsworth Louise , Nuske Elaine , Tiyce Margaret , Hing Nerilee
Published: June 2013

Partners can be especially vulnerable to the negative effects of gambling problems, but little research has sought to understand partners’ experiences from their own unique perspectives. This qualitative interpretive study explored the impacts of gambling problems on partners. In-depth interviews were conducted with 18 partners and ex-partners of people with gambling problems to understand their experiences of gambling problems from their perspectives. The findings showed that partners experienced a wide range of negative effects, especially on their financial security, their emotional, mental and physical health, and on their relationships. The financial impacts of gambling problems on partners were substantial and far-reaching. Some partners were forced to take up extra employment to cover household expenses and pay off gambling-related debts. Others lost their savings, homes, belongings and established ways of life. While these impacts were extensive, partners also experienced a range of emotional impacts that were equally devastating. Their gambling partner’s lies, dishonesty and concealment of problems and gambling behaviour created considerable distress, loss of trust and a sense of betrayal. These experiences undermined these partners’ sense of self-identity, and created additional conflicts within their relationships. Along with accumulating mental and physical health impacts, these challenges lead to separation and/or divorce for many participants. These findings point to the need for greater understanding of partners’ experiences and public health initiatives that protect partners and their families from the harmful effects of gambling problems.
The urine output definition of acute kidney injury is too liberal
Authors: Md Ralib Azrina , Pickering John W , Shaw Geoffrey M , Endre Zoltán H
Published: June 2013

Introduction

The urine output criterion of 0.5 ml/kg/hour for 6 hours for acute kidney injury (AKI) has not been prospectively validated. Urine output criteria for AKI (AKIUO) as predictors of in-hospital mortality or dialysis need were compared.

Methods

All admissions to a general ICU were prospectively screened for 12 months and hourly urine output analysed in collection intervals between 1 and 12 hours. Prediction of the composite of mortality or dialysis by urine output was analysed in increments of 0.1 ml/kg/hour from 0.1 to 1 ml/kg/hour and the optimal threshold for each collection interval determined. AKICr was defined as an increase in plasma creatinine ≥26.5 μmol/l within 48 hours or ≥50% from baseline.

Results

Of 725 admissions, 72% had either AKICr or AKIUO or both. AKIUO (33.7%) alone was more frequent than AKICr (11.0%) alone (P <0.0001). A 6-hour urine output collection threshold of 0.3 ml/kg/hour was associated with a stepped increase in in-hospital mortality or dialysis (from 10% above to 30% less than 0.3 ml/kg/hour). Hazard ratios for in-hospital mortality and 1-year mortality were 2.25 (1.40 to 3.61) and 2.15 (1.47 to 3.15) respectively after adjustment for age, body weight, severity of illness, fluid balance, and vasopressor use. In contrast, after adjustment AKIUO was not associated with in-hospital mortality or 1-year mortality. The optimal urine output threshold was linearly related to duration of urine collection (r2 = 0.93).

Conclusions

A 6-hour urine output threshold of 0.3 ml/kg/hour best associated with mortality and dialysis, and was independently predictive of both hospital mortality and 1-year mortality. This suggests that the current AKI urine output definition is too liberally defined. Shorter urine collection intervals may be used to define AKI using lower urine output thresholds.
Cardiac ischemia in patients with septic shock randomized to vasopressin or norepinephrine
Authors: Mehta Sangeeta , Granton John , Gordon Anthony C , Cook Deborah J , Lapinsky Stephen , Newton Gary , Bandayrel Kris , Little Anjuli , Siau Chuin , Ayers Dieter , Singer Joel , Lee Terry CK , Walley Keith R , Storms Michelle , Cooper D James , Holmes Cheryl L , Hebert Paul , Presneill Jeffrey , Russell James A ,   for the Vasopressin and Septic Shock Trial (VASST) Investigators
Published: June 2013

Introduction

Cardiac troponins are sensitive and specific biomarkers of myocardial necrosis. We evaluated troponin, CK, and ECG abnormalities in patients with septic shock and compared the effect of vasopressin (VP) versus norepinephrine (NE) on troponin, CK, and ECGs.

Methods

This was a prospective substudy of a randomized trial. Adults with septic shock randomly received, blinded, a low-dose infusion of VP (0.01 to 0.03 U/min) or NE (5 to 15 μg/min) in addition to open-label vasopressors, titrated to maintain a mean blood pressure of 65 to 75 mm Hg. Troponin I/T, CK, and CK-MB were measured, and 12-lead ECGs were recorded before study drug, and 6 hours, 2 days, and 4 days after study-drug initiation. Two physician readers, blinded to patient data and drug, independently interpreted ECGs.

Results

We enrolled 121 patients (median age, 63.9 years (interquartile range (IQR), 51.1 to 75.3), mean APACHE II 28.6 (SD 7.7)): 65 in the VP group and 56 in the NE group. At the four time points, 26%, 36%, 32%, and 21% of patients had troponin elevations, respectively. Baseline characteristics and outcomes were similar between patients with positive versus negative troponin levels. Troponin and CK levels and rates of ischemic ECG changes were similar in the VP and the NE groups. In multivariable analysis, only APACHE II was associated with 28-day mortality (OR, 1.07; 95% CI, 1.01 to 1.14; P = 0.033).

Conclusions

Troponin elevation is common in adults with septic shock. We observed no significant differences in troponin, CK, and ECGs in patients treated with vasopressin and norepinephrine. Troponin elevation was not an independent predictor of mortality.

Trial registration

Controlled-trials.com ISRCTN94845869
Diaphragm weakness in mechanically ventilated critically ill patients
Authors: Supinski Gerald S , Ann Callahan Leigh
Published: June 2013

Introduction

Studies indicate that mechanically ventilated patients develop significant diaphragm muscle weakness, but the etiology of weakness and its clinical impact remain incompletely understood. We assessed diaphragm strength in mechanically ventilated medical ICU patients, correlated the development of diaphragm weakness with multiple clinical parameters, and examined the relationship between the level of diaphragm weakness and patient outcomes.

Methods

Transdiaphragmatic twitch pressure (PdiTw) in response to bilateral magnetic stimulation of the phrenic nerves was measured. Diaphragm weakness was correlated with the presence of infection, blood urea nitrogen, albumin, and glucose levels. The relationship of diaphragm strength to patient outcomes, including mortality and the duration of mechanical ventilation for successfully weaned patients, was also assessed.

Results

We found that infection is a major risk factor for diaphragm weakness in mechanically ventilated medical ICU patients. Outcomes for patients with severe diaphragm weakness (PdiTw <10 cmH2O) were poor, with a markedly increased mortality (49%) compared to patients with PdiTw ≥10 cmH2O (7% mortality, P = 0.022). In addition, survivors with PdiTw <10 cmH2O required a significantly longer duration of mechanical ventilation (12.3 ± 1.7 days) than those with PdiTw ≥10 cmH2O (5.5 ± 2.0 days, P = 0.016).

Conclusions

Infection is a major cause of severe diaphragm weakness in mechanically ventilated patients. Moreover, diaphragm weakness is an important determinant of poor outcomes in this patient population.
Why do Laplace-domain waveform inversions yield long-wavelength results?
Authors: Ha Wansoo , Shin Changsoo
Published: June 2013

Laplace-domain inversions generate long-wavelength velocity models from synthetic and field data sets, unlike full-waveform inversions in the time or frequency domain. By examining the gradient directions of Laplace-domain inversions, we explain why they result in long-wavelength velocity models. The gradient direction of the inversion is calculated by multiplying the virtual source and the back-propagated wavefield. The virtual source has long-wavelength features because it is the product of the smooth forward-modeled wavefield and the partial derivative of the impedance matrix, which depends on the long-wavelength initial velocity used in the inversion. The back-propagated wavefield exhibits mild variations, except for near the receiver, in spite of the short-wavelength components in the residual. The smooth back-propagated wavefield results from the low-wavenumber pass-filtering effects of Laplace-domain Green’s function, which attenuates the high-wavenumber components of the residuals more rapidly than the low-wavenumber components. Accordingly, the gradient direction and the inversion results are smooth. Examples of inverting field data acquired in the Gulf of Mexico exhibit long-wavelength gradients and confirm the generation of long-wavelength velocity models by Laplace-domain inversion. The inversion of moving-average filtered data without short-wavelength features shows that the Laplace-domain inversion is not greatly affected by the high-wavenumber components in the field data.