bluuebunny/crossref_metadata_2025 huggingface dataset:
Burden of rotavirus gastroenteritis in children <5 years of age in Greece: hospital-based prospective surveillance (2008–2010)
Authors: Konstantopoulos Andreas , Tragiannidis Athanasios , Fouzas Sotirios , Kavaliotis Ioannis , Tsiatsou Olga , Michailidou Elisa , Spanaki Ariana , Mantagos Stefanos , Kafetzis Dimitris , Papaevangelou Vana , Gopala Kusuma , Holl Katsiaryna
Published: December 2013

Objectives

This study describes the epidemiology of rotavirus (RV) gastroenteritis (GE) disease following the introduction of RV vaccination in Greece in 2006.

Design

A prospective hospital-based surveillance.

Setting

A multicentre study was conducted at six hospitals in Greece between July 2008 and March 2010. The hospitals selected served 70% of the paediatric population in Greece.

Participants

Children aged <5 years who visited the emergency rooms (ERs) or hospitalised with acute GE or acquired acute GE 48 h after hospitalisation and with a confirmed RV-positive stool test were enrolled.

Primary and secondary outcome measures

The occurrence of RVGE among all acute GE ER visits and hospitalisations and the occurrence of nosocomial RVGE are reported with 95% exact CI. Age-specific proportions of RVGE, seasonality and prevalence of RV genotypes were estimated. Incidence rates of nosocomial acute GE and RVGE are expressed in terms of 1000 children-years with 95% exact Poisson CI. Median duration of hospitalisation and prolongation of hospitalisation due to nosocomial RVGE were reported.

Results

RVGE proportions were 10.7% (95% CI 5.5% to 18.3%) and 23.8% (95% CI 20.0% to 28.0%) of acute GE ER visits and hospitalisations, respectively; and 21.6% (95% CI 9.8% to 38.2%) of nosocomial acute GE cases. The majority of RVGE cases occurred in children aged <24 months (53%). RV infection peaked between December and May (31.4%). The most common RV genotypes were G4 (59.6%) and P[8] (75.2%). The median duration of RVGE hospitalisation was 4 days (range 1–10 days). Incidence of nosocomial RVGE was 0.3 (95% CI 0.2 to 0.7)/1000 children-years. The median prolongation of hospitalisation due to nosocomial RVGE was 5 days (range 4–7 days).

Conclusions

Our analysis report low proportions of RVGE among acute GE cases in Greece which may be attributable to available RV vaccination in Greece. Future impact/effectiveness studies are necessary to confirm this finding.

Clinical Trial Registration

NCT00751686.
Polytobacco use and multiple-product smoking among a random community sample of African-American adults
Authors: Corral Irma , Landrine Hope , Simms Denise Adams , Bess Jukelia J
Published: December 2013

Objectives

Little is known about polytobacco use among African-American adults. This study is the first to explore this among a random, statewide, community sample of African-American adults.

Setting

Community-based sampling obtained a random, household-probability sample of African-American adults from California, surveyed door to door in randomly selected census tracts statewide.

Participants

Participants were a statewide, random-household sample of N=2118 African-American adults from California who completed a survey on past 30-day smoking of cigarettes, blunts, bidis, kreteks, cigarillos, marijuana and cigars.

Results

Almost half (49.3%) of the African-American cigarette-smokers and 14.9% of the cigarette non-smokers had smoked at least one non-cigarette product in the past 30 days. Smokers had a substantial prevalence of smoking cigarillos (28.7%) and blunts (27.7%). Logistic regressions revealed that the odds of smoking most of the non-cigarette products were higher for cigarette smokers and men, inversely related to age, and unrelated to socioeconomic status. However, smoking of blunts, bidis and kreteks was not predicted by cigarette smoking.

Conclusions

Smoking of cigarillos (eg,Phillies,Black & Mild) and blunts may be prevalent among African-American cigarette-smokers and non-smokers alike, but such products are not examined in most population-level smoking research. Smoking of these products should be included in surveillance studies, in cancer prevention programmes and in healthcare provider-assessment of smoking, and addressed in smoking cessation programmes as well.
Maternal post-traumatic stress disorder, depression and alcohol dependence and child behaviour outcomes in mother–child dyads infected with HIV: a longitudinal study
Authors: Nöthling Jani , Martin Cherie L , Laughton Barbara , Cotton Mark F , Seedat Soraya
Published: December 2013

Objectives

HIV and psychiatric disorders are prevalent and often concurrent. Childbearing women are at an increased risk for both HIV and psychiatric disorders, specifically depression and post-traumatic stress disorder (PTSD). Poor mental health in the peripartum period has adverse effects on infant development and behaviour. Few studies have investigated the relationship between maternal PTSD and child behaviour outcomes in an HIV vertically infected sample. The aim of this study was to investigate whether maternal postpartum trauma exposure and PTSD were risk factors for child behaviour problems. In addition, maternal depression, alcohol abuse and functional disability were explored as cofactors.

Setting

The study was conducted in Cape Town, South Africa.

Participants

70 mother–child dyads infected with HIV were selected from a group of participants recruited from community health centres.

Design

The study followed a longitudinal design. Five measures were used to assess maternal trauma exposure, PTSD, depression, alcohol abuse and functional disability at 12 months postpartum: Life Events Checklist (LEC), Harvard Trauma Scale (HTS), Alcohol Use Disorders Identification Test (AUDIT), Center for Epidemiological Studies Depression (CESD) Scale and the Sheehan Disability Scale (SDS). Child behaviour was assessed at 42 months with the Child Behaviour Checklist (CBCL).

Results

The rate of maternal disorder was high with 50% scoring above the cut-off for depression, 22.9% for PTSD and 7% for alcohol abuse. Half of the children scored within the clinical range for problematic behaviour. Children of mothers with depression were significantly more likely to display total behaviour problems than children of mothers without depression. Maternal PTSD had the greatest explanatory power for child behaviour problems, although it did not significantly predict child outcomes.

Conclusions

This study highlights the importance of identifying and managing maternal PTSD and depression in mothers of children infected with HIV. The relationship between maternal PTSD and child behaviour warrants further investigation.
Medical students’ knowledge, attitudes and perceptions towards contraceptive use and counselling: a cross-sectional survey in Maharashtra, India
Authors: Hogmark Sara , Klingberg-Allvin Marie , Gemzell-Danielsson Kristina , Ohlsson Hannes , Essén Birgitta
Published: December 2013

Objectives

This study aimed to investigate the knowledge, attitudes and perceptions towards contraceptive use and counselling among medical students in Maharashtra, India.

Setting

Considerable global maternal mortality and morbidity could be avoided through the use of effective contraception. In India, contraception services are frequently unavailable or there are obstacles to obtaining modern, reversible contraceptives.

Participants

A cross-sectional descriptive study using a self-administered questionnaire was conducted among 1996 medical students in their fifth year of study at 27 medical colleges in the state of Maharashtra, India. Descriptive and analytical statistics interpreted the survey instrument and significant results were presented with 95% CI.

Results

Respondents expressed a desire to provide contraceptive services. A few students had experienced training in abortion care. There were misconceptions about modern contraceptive methods and the impact of sex education. Attitudes towards contraception were mainly positive, premarital counselling was supported and the influence of traditional values and negative provider attitudes on services was recognised. Gender, area of upbringing and type of medical college did not change the results.

Conclusions

Despite mostly positive attitudes towards modern contraceptives, sex education and family planning counselling, medical students in Maharashtra have misconceptions about modern methods of contraception. Preservice and in-service training in contraceptive counselling should be implemented in order to increase women's access to evidence-based maternal healthcare services.
High curvature of the internal carotid artery is associated with the presence of intracranial aneurysms
Authors: Lauric Alexandra , Safain Mina G , Hippelheuser James , Malek Adel M
Published: December 2013

Objective

Aneurysm formation in locations not involving vascular bifurcations has not been thoroughly analyzed. This study evaluated the relationship between the degree of vessel curvature and the presence of intracranial sidewall aneurysms of the internal carotid artery (ICA).

Methods

Catheter-based 3D-rotational angiographic volumes and demographic data were available for 130 ICAs. Mean and peak curvatures were evaluated for the intracranial ICA (50 mm caudal from ICA bifurcation) and for its distal segment (from ICA bifurcation to carotid siphon). Four ICA groups, statistically matched for age, were identified: non-aneurysmal women (n=33) and men (n=25), aneurysmal women (n=58) and men (n=14). Univariate and multivariate analyses were employed to evaluate statistical performance.

Results

Aneurysmal ICAs had significantly higher mean curvatures than non-aneurysmal ICAs in both the intracranial (p<0.001) and the distal ICA (p<0.001) for both genders. Peak curvature was significantly higher in aneurysmal versus non-aneurysmal men (p=0.008) but not in aneurysmal versus non-aneurysmal women (p=0.12). Mean curvature in non-aneurysmal ICAs was lower in men than in women but higher in aneurysmal ICAs in men than in women. In multivariate analysis, curvature was highly correlated with aneurysm presence but was independent of age, hypertension, hypercholesterolemia and smoking status.

Conclusions

The presence of a sidewall aneurysm on the ICA is associated with high curvature in both genders. High curvature of the intracranial ICA, as well as of the distal segment, may indicate a higher risk for aneurysm formation. Non-aneurysmal ICAs are less curved in men than in women, which may explain the gender predisposition to aneurysm formation.
OVERVIEW OF THE STUDY OF COMPLEX SHAPES OF FLUID MEMBRANES, THE HELFRICH MODEL AND NEW APPLICATIONS
Authors: OU-YANG Z. C. , TU Z. C.
Published: December 2013

Some progresses in shape problems following the Helfrich model are reported. Based on the Helfrich model, we have predicted not only the exact solution for discoidal shape of red blood cells but also a special kind of toroidal vesicle with the ratio of two generation radii being [Formula: see text]. The Helfrich model can also be extended to investigate the complex structures in other soft matters such as the formation of focal conic domains in smectic liquid crystal, the tube-to-sphere transition in peptide nanostructures, and icosahedral configuration of small virus capsids.
GLOBAL CLF STABILIZATION OF SYSTEMS WITH POINT-DISSIPATIVE FREE DYNAMICS VIA ADMISSIBLE CONTROLS: CHAOS CONTROL OF A CHUA'S SYSTEM
Authors: SOLÍS-DAUN JULIO
Published: December 2013

The aim of this paper is to address the global asymptotic stabilization (GAS) of the class of affine control systems which are open-loop point-dissipatives (have compact global attractors), that include some chaotic systems (e.g. Lorenz, Chen, smooth Chua), via admissible (bounded and regular) feedback controls. The existence of the global attractor for the free dynamics, whose overestimation is achieved by a Lyapunov function V(x), allows us to use V(x) as a basis to obtain a control Lyapunov function (CLF) in order to apply our control design method (entailed from Artstein and Sontag's CLF-stabilization approach) developed for the GAS of affine control systems via admissible feedback controls. We illustrate the results with the chaos control of a smooth (cubic) Chua's system via admissible feedback controls.
NUMERICAL SIMULATION OF FRACTIONAL BIOHEAT EQUATION IN HYPERTHERMIA TREATMENT
Authors: DAMOR R. S. , KUMAR SUSHIL , SHUKLA A. K.
Published: December 2013

This paper deals with the study of fractional bioheat equation for hyperthermia treatment in cancer therapy with external electromagnetic (EM) heating. Time fractional derivative is considered as Caputo fractional derivative of order α ∈ (0, 1]. Numerical solution is obtained by implicit finite difference method. The effect of anomalous diffusion in tissue has been studied. The temperature profile and thermal damage over the entire affected region are obtained for different values of α.
FINITE ELEMENT MODEL TO STUDY THE MECHANICS OF CALCIUM REGULATION IN OOCYTE
Authors: PANDAY SUNIL , PARDASANI KAMAL RAJ
Published: December 2013

At various stages of fertilization specific spatial and temporal patterns of Ca 2+ are required for oocyte maturation. It is crucial to understand the mechanics of Ca 2+ regulation in cytosol of oocytes, in order to have better understanding of fertilization process. In this paper, a finite element model of cytosolic calcium regulation in oocyte has been developed for a two-dimensional unsteady state case. The model incorporates the important biophysical processes like diffusion, reaction, leak from endoplasmic recticulum (ER), efflux from cytosol to ER via sarco-ER calcium adenosine triphosphate (SERCA) pumps, buffers and sodium calcium exchanger. Appropriate boundary conditions have been framed. The effect of source, buffer, sodium calcium exchanger, etc. on spatial and temporal patterns of calcium in oocyte have been studied with the help of numerical results.
AN AUTOMATIC METHOD FOR THE DESIGN OF MULTIDIMENSIONAL SCHEMAS FROM OBJECT ORIENTED DATABASES
Authors: HACHAICHI YASSER , FEKI JAMEL
Published: December 2013

A data warehouse (DW) is a large data repository system designed for decision-making purposes. Its design relies on a specific model called multidimensional. This multidimensional model supports analyses of huge volumes of data that trace the enterprise's activities over time. Several design methods were proposed to build multidimensional schemas from either the relational data model or the entity-relationship data model. Almost all proposals that treated the object-oriented data model assume the presence of the data source UML class-diagram. However, in practice, either such a diagram does not exist or is obsolete due to multiple changes/evolutions of the information system. Furthermore, these few proposals require an intense manual intervention of the designer, which requires a high expertise both in the DW domain and in the object database domain. To overcome these disadvantages, this work proposes an automatic DW schema design method starting from an object database (schema and its instances). This method applies a set of extraction rules to identify multidimensional concepts and to generate star schemas. It is defined for the standard ODMG model and, thus, can be adapted with slight changes for other object database models. In addition, its extraction rules have the merit of being independent of the domain semantics. Furthermore, they automatically generate schemas classified according to their analytical potential; this classification helps the DW designer in selecting the most relevant schemas among the generated ones. Finally, being automatic, our method is supported by a toolset that also prepares for the automatic generation of the Extract Transform and Load procedures used to load the DW.
ROBUST ESTIMATION AND FORECASTING OF THE CAPITAL ASSET PRICING MODEL
Authors: BIAN GUORUI , McALEER MICHAEL , WONG WING-KEUNG
Published: December 2013

In this paper, we develop a modified maximum likelihood (MML) estimator for the multiple linear regression model with underlying student t distribution. We obtain the closed form of the estimators, derive the asymptotic properties, and demonstrate that the MML estimator is more appropriate for estimating the parameters of the Capital Asset Pricing Model (CAPM) by comparing its performance with least squares estimators (LSE) on the monthly returns of US portfolios. The empirical results reveal that the MML estimators are more efficient than LSE in terms of the relative efficiency of one-step-ahead forecast mean square error in small samples.
A Formulation and Heuristic Approach to Task Allocation and Routing of UAVs under Limited Communication
Authors: Sabo Chelsea , Kingston Derek , Cohen Kelly
Published: December 2013

Unmanned Air Vehicle (UAV) teams are anticipated to provide surveillance support through algorithms, software, and automation. It is desirable to have algorithms that compute effective and efficient routes for multiple UAVs across a variety of missions. These algorithms must be realizable, practical, and account for uncertainties. In surveillance missions, UAVs act as mobile wireless communication nodes in a larger, underlying network consisting of targets where information is to be collected and base stations where information is to be delivered. The role of UAVs in these networks has primarily been to maintain or improve connectivity while undervaluing routing efficiency. Moreover, many current routing strategies for UAVs ignore communication constraints even though neglecting communication can lead to suboptimal tour designs. Generating algorithms for autonomous vehicles that work effectively despite these communication restrictions is key for the future of UAV surveillance missions. A solution is offered here based on a variation of the traditional vehicle routing problem and a simple communication model. In this work, the new routing formulation is defined, analyzed, and a heuristic approach is motivated and described. Simulation results show that the heuristic algorithm gives near-optimal results in real time, allowing it to be used for large problem sizes and extended to dynamic scenarios.
Intracellular Ca2+ oscillations generated via the Ca2+-sensing receptor are mediated by negative feedback by PKCα at Thr888
Authors: Young Steven H. , Rey Osvaldo , Sinnett-Smith James , Rozengurt Enrique
Published: December 2013

To clarify the mechanism(s) underlying intracellular Ca2+ concentration ([Ca2+]i) oscillations induced by an elevation in extracellular Ca2+ concentration ([Ca2+]e) via the extracellular Ca2+-sensing receptor (CaR), we analyzed the pattern of [Ca2+]i response in multiple (2,303) individual HEK-293 cells transfected with the human CaR. An increase in the [Ca2+]e from 1.5 to 3 mM produced oscillatory fluctuations in [Ca2+]i in 70% of the cell population. To determine the role of PKC in the generation of [Ca2+]i oscillations, cells were exposed to increasing concentrations (0.5–5 μM) of the preferential PKC inhibitor Ro-31-8220 before stimulation by extracellular Ca2+. Ro-31-8220 at 3–5 μM completely eliminated the [Ca2+]e-evoked [Ca2+]i oscillations and transformed the pattern to a peak and sustained plateau response. Treatment with other broad PKC inhibitors, including GFI or Gö6983, produced an identical response. Similarly, treatment with Ro-31-8220 or GFI eliminated [Ca2+]e-evoked [Ca2+]i oscillations in colon-derived SW-480 cells expressing the CaR. Treatment with inhibitors targeting classic PKCs, including Gö6976 and Ro-32-0432 as well as small interfering RNA-mediated knockdown of PKCα, strikingly reduced the proportion of cell displaying [Ca2+]e-evoked [Ca2+]i oscillations. Furthermore, none of the cells analyzed expressing a CaR mutant in which the major PKC phosphorylation site Thr888 was converted to alanine (CaRT888A) showed [Ca2+]i oscillations after CaR activation. Our results show that [Ca2+]i oscillations induced by activation of the CaR in response to an increase in extracellular Ca2+ or exposure to the calcimimetic R-568 result from negative feedback involving PKCα-mediated phosphorylation of the CaR at Thr888.
Secreted Frizzled-related protein 2 as a target in antifibrotic therapeutic intervention
Authors: Mastri Michalis , Shah Zaeem , Hsieh Karin , Wang Xiaowen , Wooldridge Bailey , Martin Sean , Suzuki Gen , Lee Techung
Published: December 2013

Progressive fibrosis is a pathological hallmark of many chronic diseases responsible for organ failure. Although there is currently no therapy on the market that specifically targets fibrosis, the dynamic fibrogenic process is known to be regulated by multiple soluble mediators that may be therapeutically intervened. The failing hamster heart exhibits marked fibrosis and increased expression of secreted Frizzled-related protein 2 (sFRP2) amenable to reversal by mesenchymal stem cell (MSC) therapy. Given the previous demonstration that sFRP2-null mice subjected to myocardial infarction exhibited reduced fibrosis and improved function, we tested whether antibody-based sFRP2 blockade might counteract the fibrogenic pathway and repair cardiac injury. Cardiomyopathic hamsters were injected intraperitoneally twice a week each with 20 μg of sFRP2 antibody. Echocardiography, histology, and biochemical analyses were performed after 1 mo. sFRP2 antibody increased left ventricular ejection fraction from 40 ± 1.2 to 49 ± 6.5%, whereas saline and IgG control exhibited a further decline to 37 ± 0.9 and 31 ± 3.2%, respectively. Functional improvement is associated with a ∼50% reduction in myocardial fibrosis, ∼65% decrease in apoptosis, and ∼75% increase in wall thickness. Consistent with attenuated fibrosis, both MSC therapy and sFRP2 antibody administration significantly increased the activity of myocardial matrix metalloproteinase-2. Gene expression analysis of the hamster heart and cultured fibroblasts identified Axin2 as a downstream target, the expression of which was activated by sFRP2 but inhibited by therapeutic intervention. sFRP2 blockade also increased myocardial levels of VEGF and hepatocyte growth factor (HGF) along with increased angiogenesis. These findings highlight the pathogenic effect of dysregulated sFRP2, which may be specifically targeted for antifibrotic therapy.
miR-23a is decreased during muscle atrophy by a mechanism that includes calcineurin signaling and exosome-mediated export
Authors: Hudson Matthew B. , Woodworth-Hobbs Myra E. , Zheng Bin , Rahnert Jill A. , Blount Mitsi A. , Gooch Jennifer L. , Searles Charles D. , Price S. Russ
Published: December 2013

Skeletal muscle atrophy is prevalent in chronic diseases, and microRNAs (miRs) may play a key role in the wasting process. miR-23a was previously shown to inhibit the expression of atrogin-1 and muscle RING-finger protein-1 (MuRF1) in muscle. It also was reported to be regulated by cytoplasmic nuclear factor of activated T cells 3 (NFATc3) in cardiomyocytes. The objective of this study was to determine if miR-23a is regulated during muscle atrophy and to evaluate the relationship between calcineurin (Cn)/NFAT signaling and miR-23a expression in skeletal muscle cells during atrophy. miR-23a was decreased in the gastrocnemius of rats with acute streptozotocin-induced diabetes, a condition known to increase atrogin-1 and MuRF1 expression and cause atrophy. Treatment of C2C12 myotubes with dexamethasone (Dex) for 48 h also reduced miR-23a as well as RCAN1.4 mRNA, which is transcriptionally regulated by NFAT. NFATc3 nuclear localization and the amount of miR-23a decreased rapidly within 1 h of Dex administration, suggesting a link between Cn signaling and miR-23a. The level of miR-23a was lower in primary myotubes from mice lacking the α- or β-isoform of the CnA catalytic subunit than wild-type mice. Dex did not further suppress miR-23a in myotubes from Cn-deficient mice. Overexpression of CnAβ in C2C12 myotubes prevented Dex-induced suppression of miR-23a. Finally, miR-23a was present in exosomes isolated from the media of C2C12 myotubes, and Dex increased its exosomal abundance. Dex did not alter the number of exosomes released into the media. We conclude that atrophy-inducing conditions downregulate miR-23a in muscle by mechanisms involving attenuated Cn/NFAT signaling and selective packaging into exosomes.
Orexigenic response to tail pinch: role of brain NPY1 and corticotropin releasing factor receptors
Authors: Goebel-Stengel Miriam , Stengel Andreas , Wang Lixin , Taché Yvette
Published: December 2013

Tail pinch stimulates food intake in rats. We investigated brain mechanisms of this response and the influence of repeated exposure. Sprague-Dawley rats received acute (5 min) or repeated (5 min/day for 14 days) tail pinch using a padded clip. Acute tail pinch increased 5-min food intake compared with control (0.92 ± 0.2 vs. 0.03 ± 0.01 g, P < 0.01). This response was inhibited by 76% by intracerebroventricular injection of BIBP-3226, a neuropeptide Y1 (NPY1) receptor antagonist, increased by 48% by astressin-B, a corticotropin-releasing factor (CRF) receptor antagonist, and not modified by S-406-028, a somatostatin subtype 2 antagonist. After the 5-min tail pinch without food, blood glucose rose by 21% ( P < 0.01) while changes in plasma acyl ghrelin (+41%) and adrenocorticotropic hormone (+37%) were not significant. Two tail pinches (45 min apart) activate pontine and hindbrain catecholaminergic and hypothalamic paraventricular CRF neurons. After 14 days of repeated tail pinch, the 5-min orexigenic response was not significantly different from days 2 to 11 but reduced by 50% thereafter ( P < 0.001). Simultaneously, the 5-min fecal pellet output increased during the last 5 days compared with the first 5 days (+58%, P < 0.05). At day 14, the body weight gain was reduced by 22%, with a 99% inhibition of fat gain and a 25% reduction in lean mass ( P < 0.05). The orexigenic response to acute 5-min tail pinch is likely to involve the activation of brain NPY1 signaling, whereas that of CRF tends to dampen the acute response and may contribute to increased defecation and decreased body weight gain induced by repeated tail pinch.
Extracellular fetal hemoglobin induces increases in glomerular permeability: inhibition with α1-microglobulin and tempol
Authors: Sverrisson Kristinn , Axelsson Josefin , Rippe Anna , Gram Magnus , Åkerström Bo , Hansson Stefan R. , Rippe Bengt
Published: December 2013

Extracellular fetal hemoglobin (HbF) and adult hemoglobin (HbA) are proinflammatory and generate ROS. Increased plasma levels of extracellular HbF have recently been reported to occur in early preeclampsia. α1-Microglobulin (A1M) is a physiological heme-binding protein and radical scavenger that has been shown to counteract vascular permeability increases induced by HbA in the perfused placenta. The present study was performed to investigate whether HbF and HbA will increase glomerular permeability in vivo and to test whether A1M and tempol, a ROS scavenger, can prevent their effects. Anesthetized Wistar rats were continuously infused intravenously with either HbA, HbF, or cyano-inactivated HbF together with FITC-Ficoll-70/400, inulin, and51Cr-labeled EDTA for 2 h. Plasma samples and urine samples (left ureter) were taken repeatedly and analyzed by high-performance size exclusion chromatography to assess glomerular sieving coefficients for Ficoll of radius 10–80 Å. In separate experiments, A1M or tempol was given before and during Hb infusions. Extracellular HbF caused rapid, transient increases in glomerular permeability to large Ficoll molecules (50–80Å), contrary to the effects of HbA and cyano-inactivated HbF. For HbF, glomerular sieving coefficients for Ficoll of radius 60Å increased from 3.85 ± 0.85 × 10−5to 2.60 ± 0.96 × 10−4at 15 min, changes that were abrogated by tempol and reduced by A1M. In conclusion, our data demonstrate that extracellular HbF, infused systemically, can acutely increase glomerular permeability through inducing oxidative stress.
ENaC activity is increased in isolated, split-open cortical collecting ducts from protein kinase Cα knockout mice
Authors: Bao Hui-Fang , Thai Tiffany L. , Yue Qiang , Ma He-Ping , Eaton Amity F. , Cai Hui , Klein Janet D. , Sands Jeff M. , Eaton Douglas C.
Published: December 2013

The epithelial Na channel (ENaC) is negatively regulated by protein kinase C (PKC) as shown using PKC activators in a cell culture model. To determine whether PKCα influences ENaC activity in vivo, we examined the regulation of ENaC in renal tubules from PKCα−/−mice. Cortical collecting ducts were dissected and split open, and the exposed principal cells were subjected to cell-attached patch clamp. In the absence of PKCα, the open probability ( Po) of ENaC was increased three-fold vs. wild-type SV129 mice (0.52 ± 0.04 vs. 0.17 ± 0.02). The number of channels per patch was also increased. Using confocal microscopy, we observed an increase in membrane localization of α-, β-, and γ-subunits of ENaC in principal cells in the cortical collecting ducts of PKCα−/−mice compared with wild-type mice. To confirm this increase, one kidney from each animal was perfused with biotin, and membrane protein was pulled down with streptavidin. The nonbiotinylated kidney was used to assess total protein. While total ENaC protein did not change in PKCα−/−mice, membrane localization of all the ENaC subunits was increased. The increase in membrane ENaC could be explained by the observation that ERK1/2 phosphorylation was decreased in the knockout mice. These results imply a reduction in ENaC membrane accumulation and Poby PKCα in vivo. The PKC-mediated increase in ENaC activity was associated with an increase in blood pressure in knockout mice fed a high-salt diet.
COX2 inhibition during nephrogenic period induces ANG II hypertension and sex-dependent changes in renal function during aging
Authors: Reverte Virginia , Tapia Antonio , Loria Analia , Salazar Francisco , Llinas M. Teresa , Salazar F. Javier
Published: December 2013

This study was performed to test the hypothesis that ANG II contributes to the hypertension and renal functional alterations induced by a decrease of COX2 activity during the nephrogenic period. It was also examined whether renal functional reserve and renal response to volume overload and high sodium intake are reduced in 3–4- and 9–11-mo-old male and female rats treated with vehicle or a COX2 inhibitor during nephrogenic period (COX2np). Our data show that this COX2 inhibition induces an ANG II-dependent hypertension that is similar in male and female rats. Renal functional reserve is reduced in COX2np-treated rats since their renal response to an increase in plasma amino acids levels is abolished, and their renal ability to eliminate a sodium load is impaired ( P < 0.05). This reduction in renal excretory ability is similar in both sexes during aging but does not induce the development of a sodium-sensitive hypertension. However, the prolonged high-sodium intake at 9–11 mo of age leads to a greater proteinuria in male than in female (114 ± 12 μg/min vs. 72 ± 8 μg/min; P < 0.05) COX2np-treated rats. Renal hemodynamic sensitivity to acute increments in ANG II is unaltered in both sexes and at both ages in COX2np-treated rats. In summary, these results indicate that the reduction of COX2 activity during nephrogenic period programs for the development of an ANG II-dependent hypertension, reduces renal functional reserve to a similar extent in both sexes, and increases proteinuria in males but not in females when there is a prolonged increment in sodium intake.
Neuromodulation of evoked muscle potentials induced by epidural spinal-cord stimulation in paralyzed individuals
Authors: Sayenko Dimitry G. , Angeli Claudia , Harkema Susan J. , Edgerton V. Reggie , Gerasimenko Yury P.
Published: December 2013

Epidural stimulation (ES) of the lumbosacral spinal cord has been used to facilitate standing and voluntary movement after clinically motor-complete spinal-cord injury. It seems of importance to examine how the epidurally evoked potentials are modulated in the spinal circuitry and projected to various motor pools. We hypothesized that chronically implanted electrode arrays over the lumbosacral spinal cord can be used to assess functionally spinal circuitry linked to specific motor pools. The purpose of this study was to investigate the functional and topographic organization of compound evoked potentials induced by the stimulation. Three individuals with complete motor paralysis of the lower limbs participated in the study. The evoked potentials to epidural spinal stimulation were investigated after surgery in a supine position and in one participant, during both supine and standing, with body weight load of 60%. The stimulation was delivered with intensity from 0.5 to 10 V at a frequency of 2 Hz. Recruitment curves of evoked potentials in knee and ankle muscles were collected at three localized and two wide-field stimulation configurations. Epidural electrical stimulation of rostral and caudal areas of lumbar spinal cord resulted in a selective topographical recruitment of proximal and distal leg muscles, as revealed by both magnitude and thresholds of the evoked potentials. ES activated both afferent and efferent pathways. The components of neural pathways that can mediate motor-evoked potentials were highly dependent on the stimulation parameters and sensory conditions, suggesting a weight-bearing-induced reorganization of the spinal circuitries.
Low-frequency stimulation evokes serotonin release in the nucleus accumbens and induces long-term depression via production of endocannabinoid
Authors: Burattini Costanza , Battistini Giulia , Tamagnini Francesco , Aicardi Giorgio
Published: December 2013

The nucleus accumbens (NAc), a major component of the mesolimbic system, is involved in the mediation of reinforcing and addictive properties of many dependence-producing drugs. Glutamatergic synapses within the NAc can express plasticity, including a form of endocannabinoid (eCB)-long-term depression (LTD). Recent evidences demonstrate cross talk between eCB signaling pathways and those of other receptor systems, including serotonin (5-HT); the extensive colocalization of CB1 and 5-HT receptors within the NAc suggests the potential for interplay between them. In the present study, we found that 20-min low-frequency (4 Hz) stimulation (LFS-4Hz) of glutamatergic afferences in rat brain slices induces a novel form of eCB-LTD in the NAc core, which requires 5-HT2 and CB1 receptor activation and L-type voltage-gated Ca2+ channel opening. Moreover, we found that exogenous 5-HT application (5 μM, 20 min) induces an analogous LTD (5-HT-LTD) at the same synapses, requiring the activation of the same receptors and the opening of the same Ca2+ channels; LFS-4Hz-LTD and 5-HT-LTD were mutually occlusive. Present results suggest that LFS-4Hz induces the release of 5-HT, which acts at 5-HT2 postsynaptic receptors, increasing Ca2+ influx through L-type voltage-gated channels and 2-arachidonoylglycerol production and release; the eCB travels retrogradely and binds to presynaptic CB1 receptors, causing a long-lasting decrease of glutamate release, resulting in LTD. These observations might be helpful to understand the neurophysiological mechanisms underlying drug addiction, major depression, and other psychiatric disorders characterized by dysfunction of 5-HT neurotransmission in the NAc.
Low-frequency stimulation induces long-term depression and slow onset long-term potentiation at perforant path-dentate gyrus synapses in vivo
Authors: Gonzalez Jossina , Morales Isaiah S. , Villarreal Desiree M. , Derrick Brian E.
Published: December 2013

The expression of homosynaptic long-term depression (LTD) is thought to mediate a crucial role in sustaining memory function. Our in vivo investigations of LTD expression at lateral (LPP) and medial perforant path (MPP) synapses in the dentate gyrus (DG) corroborate prior demonstrations that PP-DG LTD is difficult to induce in intact animals. In freely moving animals, LTD expression occurred inconsistently among LPP-DG and MPP-DG responses. Interestingly, following acute electrode implantation in anesthetized rats, low-frequency stimulation (LFS; 900 pulses, 1 Hz) promotes slow-onset LTP at both MPP-DG and LPP-DG synapses that utilize distinct induction mechanisms. Systemic administration of the N-methyl-d-aspartate (NMDA) receptor antagonist (+/−)-cyclopiperidine-6-piperiperenzine (CPP; 10 mg/kg) 90 min before LFS selectively blocked MPP-DG but not LPP-DG slow onset LTP, suggesting MPP-DG synapses express a NMDA receptor-dependent slow onset LTP whereas LPP-DG slow onset LTP induction is NMDA receptor independent. In experiments where paired-pulse LFS (900 paired pulses, 200-ms paired-pulse interval) was used to induce LTD, paired-pulse LFS of the LPP resulted in rapid onset LTP of DG responses, whereas paired-pulse LFS of the MPP induced slow onset LTP of DG responses. Although LTD observations were very rare following acute electrode implantation in anesthetized rats, LPP-DG LTD was demonstrated in some anesthetized rats with previously implanted electrodes. Together, our data indicate in vivo PP-DG LTD expression is an inconsistent phenomenon that is primarily observed in recovered animals, suggesting perturbation of the dentate through surgery-related tissue trauma influences both LTD incidence and LTP induction at PP-DG synapses in vivo.
Optimizing of Iterative Turbo Equalizer for Underwater Sensor Communication
Authors: Jung Ji Won , Kim Ki Man
Published: December 2013

We presented an iterative turbo equalization to cope with intersymbol interference induced by reflection of sea level and sea bottom for underwater sensor communication channel. Iterative turbo equalizer consists of inner codes and outer codes; we employ decision feedback equalizer as an outer code and turbo codes as an inner code. Equalizer and decoder are connected through the interleaving and deinterleaving that update each other's information repeatedly. At the receiver side, we resort to powerful turbo equalization algorithms that iteratively exchange probabilistic information between inner decoder and outer decoder, thereby reducing the error rates significantly. Furthermore, we expand iterative turbo equalizer techniques for single-input-single-output (SISO) system to multiple-input-multiple-output (MIMO) system in order to increase data rates for underwater sensor communication channel. Based on experimental channel response, we confirmed that the performance is improved as iteration number is increased. The performance is improved by 3.5 [dB] compared to noniteration for SISO channel and by 1 [dB] for MIMO channel, respectively. We also decided that optimal iterations are 3. Very important for a successful decoding is the channel estimation, which is also discussed.
Improvement and Simulation of an Autonomous Time Synchronization Algorithm for a Layered Satellite Constellation
Authors: Huang Feijiang , Lu Xiaochun , Liu Guangcan , Sun Liping , Sheng Wang , Wang Yingde
Published: December 2013

Autonomous time synchronization for satellite constellations is a key technology to establish a constellation system time without the use of a ground station. The characteristics of satellite visibility time for layered satellite constellations containing geostationary earth orbit (GEO), inclined geosynchronous orbit (IGSO), and medium earth orbit (MEO) satellites are simulated by establishing a visible satellite model. Based on the satellite visible simulation results for a layered constellation, this study investigates the autonomous time synchronization algorithm that corresponds to the layered constellation structure, analyzes the main error of the time synchronization algorithm, and proposes methods to improve the characteristics of satellite movement in the constellation. This study uses an improved two-way time synchronization algorithm for autonomous time synchronization in the GEO-MEO satellite layer of a layered satellite constellation. The simulation results show that in a condition with simulation errors, the time synchronization precision of this improved algorithm can be controlled within 5 ns and used in high-precision autonomous time synchronization between layered satellite constellations.
Auricular Acupressure to Improve Menstrual Pain and Menstrual Distress and Heart Rate Variability for Primary Dysmenorrhea in Youth with Stress
Authors: Wang Yu-Jen , Hsu Chin-Che , Yeh Mei-Ling , Lin Jaung-Geng
Published: December 2013

Background. Dysmenorrhea and accompanying symptoms can have a negative impact on academic achievement, physical activity and functioning, and quality of life. Unfortunately, stress increases the sensitivity and severity of pain, activating sympathetic responses while inhibiting parasympathetic responses.Objective. This study used objective, physiological measurements to evaluate the effects of auricular acupressure on menstrual pain and menstrual distress in young college students with primary dysmenorrhea across two menstrual cycles. The aim was to determine if significant differences could be detected between the intervention and follow-up phases after controlling life stress.Design. A one-group experimental research design was used, and repeated measurements and followups were done. Thirty-two women completed questionnaires and physiological parameters were measured.Results. Significant differences between the intervention and follow-up phases were found for high frequency (HF) and blood pressure on day 1 and no significant differences in menstrual pain and menstrual distress, heart rate variability, low frequency (LF), LF/HF ratio, or heart rate.Conclusion. Auricular acupressure effectively increases parasympathetic activity to maintain autonomic function homeostasis in young women with primary dysmenorrhea and may have a value in alleviating menstrual pain and menstrual distress in a high-stress life. Future studies should consider stress, stimulus dose of auricular acupressure, severity of menstrual pain, and a longitudinal research design.
Optimization Controller for Mechatronic Sun Tracking System to Improve Performance
Authors: Engin Mustafa , Engin Dilşad
Published: December 2013

An embedded system that contains hardware and software was developed for two-axis solar tracking system to improve photovoltaic panel utilization. The hardware section of the embedded system consists of a 32-bit ARM core microcontroller, motor driver circuits, a motion control unit, pyranometer, GPS receiver, and an anemometer. The real-time control algorithm enables the solar tracker to operate automatically without external control as a stand-alone system, combining the advantages of the open-loop and the closed-loop control methods. The pyranometer is employed to continuously send radiation data to the controller if the measured radiation is above the lower radiation limit the photovoltaic panel can generate power, guaranteeing the solar tracking process to be highly efficient. The anemometer is utilized in the system to ensure that the solar tracking procedure halts under high wind speed conditions to protect the entire system. Latitude, longitude, altitude, date, and real-time clock data are provided by GPS receiver. The algorithm calculates solar time using astronomical equations with GPS data and converts it to pulse-width modulated motor control signal. The overall objective of this study is to develop a control algorithm that improves performance and reliability of the two-axis solar tracker, focusing on optimization of the controller board, drive hardware, and software.
Effects of Inflow Mach Number and Step Height on Supersonic Flows over a Backward-Facing Step
Authors: Liu Haixu , Wang Bing , Guo Yincheng , Zhang Huiqiang , Lin Wenyi
Published: December 2013

The backward-facing step is practically implicated in many devices, encountering the massive separation flows. In the present study, simulations of supersonic flow over a backward-facing step have been carried out employing both RANS and LES. The simulated results are validated against the experimental data. The results of RANS and LES show a good comparison with the experimental results. Different inflow Mach numbers and expansion ratios are also investigated. The reattachment length decreases with the increase of inflow Mach number. The duct height has a great effect on the flow patterns. The present conclusions are helpful to understand the physics in supersonic separation flows and also provide theory basis for engineering applications.
Robust Vessel Segmentation in Fundus Images
Authors: Budai A. , Bock R. , Maier A. , Hornegger J. , Michelson G.
Published: December 2013

One of the most common modalities to examine the human eye is the eye-fundus photograph. The evaluation of fundus photographs is carried out by medical experts during time-consuming visual inspection. Our aim is to accelerate this process using computer aided diagnosis. As a first step, it is necessary to segment structures in the images for tissue differentiation. As the eye is the only organ, where the vasculature can be imaged in an in vivo and noninterventional way without using expensive scanners, the vessel tree is one of the most interesting and important structures to analyze. The quality and resolution of fundus images are rapidly increasing. Thus, segmentation methods need to be adapted to the new challenges of high resolutions. In this paper, we present a method to reduce calculation time, achieve high accuracy, and increase sensitivity compared to the originalFrangimethod. This method contains approaches to avoid potential problems like specular reflexes of thick vessels. The proposed method is evaluated using theSTAREandDRIVEdatabases and we propose a new high resolution fundus database to compare it to the state-of-the-art algorithms. The results show an average accuracy above 94% and low computational needs. This outperforms state-of-the-art methods.
Robust and Passive Constrained Fuzzy Control for Discrete Fuzzy Systems with Multiplicative Noises and Interval Time Delay
Authors: Chang Wen-Jer , Ku Cheung-Chieh , Fu Zong-Guo
Published: December 2013

The passive fuzzy control for discrete-time uncertain Takagi-Sugeno (T-S) fuzzy models with multiplicative noises and time delay is investigated subject to robust asymptotical stability. Applying Jensen’s inequality and free-weighting matrix technique, less conservative sufficient conditions are derived via choosing Lyapunov function to analyze and synthesize the robust asymptotical stability and passivity of closed-loop system. The derived conditions are not strictly linear matrix inequality (LMI) problems, thus the cone complementarity technique is employed to propose a suboptimal technique to solve the proposed nonstrictly LMI problems. An algorithm is developed in this paper to design the fuzzy controller which can be accomplished by state-feedback scheme or output-feedback scheme. Finally, numerical examples are provided to demonstrate the feasibility and applicability of the proposed fuzzy controller design technique.
Fish Tank Granuloma Caused byMycobacterium marinumin Two Aquarists: Two Case Reports
Authors: Slany Michal , Jezek Petr , Bodnarova Monika
Published: December 2013

Mycobacterium marinum, the cause of chronic systemic infections in fish, occasionally causes granulomatous skin and soft tissue lesions in humans. Cutaneous mycobacterial infection in two patients owing to unusual circumstances is presented in this report. The first patient was infected through improper hygienic behavior, while infection in the second patient was previously misdiagnosed as rheumatoid arthritis and treated with methylprednisolone for a period of three months, which resulted in a rare systemic spread ofM. marinuminto the bones of the hand, testis, and epididymis. Simultaneously, screening for possible sources ofM. marinuminfection in patients' aquaria revealed positive fish harboring VNTR profiles identical to those obtained for clinical isolates from patients.