bluuebunny/crossref_metadata_2025 huggingface dataset:
Micronutrients (Other than iron) and Helicobacter pylori Infection: A Systematic Review
Authors: Lahner Edith , Persechino Severino , Annibale Bruno
Published: January 2012

Background:  Many micronutrients depend on a healthy stomach for absorption. Helicobacter pylori chronic gastritis may alter gastric physiology affecting homeostasis of vitamins and minerals.

Objectives:  Systematic review to assess whether H. pylori infection is associated with reduced micronutrient levels (other than iron) in the plasma or gastric juice and whether low micronutrient levels are modified by eradication treatment.

Method:  Medline was searched for relevant publications from inception to June 2010. Studies describing micronutrient levels in H. pylori‐infected and not‐infected adults and/or the effect of eradication treatment on micronutrient levels were included.

Findings:  Fifty‐two publications were selected: 46 investigated the association between H. pylori infection and reduced micronutrient levels and 14 the effect of eradication treatment on micronutrient levels. Sixty‐four studies investigated vitamins (23 ascorbic acid, four ß‐carotene, 21 cobalamin, 11 folate, and five α‐tocopherol) and 10 addressed minerals (one calcium, one copper, one magnesium, one phosphorus, three selenium, and three zinc). Pooled standardized mean differences in micronutrient levels showed positive associations with H. pylori infection for ascorbic acid (gastric juice, −1.087) and cobalamin (−0.744), and a positive effect of eradication treatment, which increased ascorbic acid in the gastric juice (−1.408) and serum cobalamin (−1.910). No significant association between infection and low folate levels was observed. Meta‐analyses for other micronutrients were not performed owing to insufficient data.

Conclusions:  Meta‐analyses indicate that H. pylori infection is associated with reduced levels of ascorbic acid and cobalamin, supported by the positive effect of eradication treatment. For other micronutrients, further studies are needed.
Arginine 66 Residue of Fur is Required for the Regulatory Function of this Protein in the Acid Adaptation Mechanism of Helicobacter pylori
Authors: Toledo Héctor , Villafaena Carlos , Valenzuela Manuel , López‐Solís Remigio
Published: January 2012

Background:  Helicobacter pylori colonizes the gastric mucosa and must survive the acid pH of that environment. Like other enteric bacterial pathogens, including Salmonella enterica, H. pylori develops an acid tolerance response that is dependent on the function of the transcriptional regulator protein Fur.

Objective:  To explore by site‐directed mutagenesis whether two particular amino acid residues in the amino acid sequence of the H. pylori Fur protein, arginine 66 and histidine 99, are involved in the acid response mechanism in this bacterium.

Materials and Methods:  Complementation assays in Escherichia coli H1780 (fur null mutant) both with plasmids carrying the H. pylori fur gene bearing substitution mutations R66A or H99A or R66A/H99A and with the H. pylori Fur‐R66A mutant were conducted. Wild‐type and mutated Fur proteins from H. pylori were assayed by using the fiu::lacZ reporter gene in the E. coli H1780 heterologous system at various pH and iron concentrations.

Results:  Both bacterial growth and repression of the reporter gene were impaired under acid conditions in E. coli H1780 complemented with pUC19‐fur‐R66A. Also, in the H. pylori Fur‐R66 strain bacterial growth and speA gene expression were impaired under acid conditions.

Conclusions:  Arginine 66 but not histidine 99 in H. pylori Fur is required for the regulatory function of the Fur protein in the acid adaptation mechanism of the bacterium.
Mucoid Helicobacter pylori Isolates with Fast Growth under Microaerobic and Aerobic Conditions
Authors: Siavoshi Farideh , Saniee Parastoo , Atabakhsh Mojgan , Pedramnia Shahrzad , Tavakolian Atefeh , Mirzaei Masoumeh
Published: January 2012

Background:  Helicobacter pylori is microaerobic and turns into coccoid under aerobic conditions. In this study, two mucoid strains, A and D, were isolated from gastric biopsies which grew well on blood agar after 24‐hour incubation under aerobic as well as microaerobic conditions. The aim of this study was to identify these strains and compare their growth under aerobic and microaerobic conditions with that of control H. pylori.

Materials and Methods:  The two isolates A and D were identified as H. pylori according to microscopic morphology, urease, catalase and oxidase tests. Their growth under humidified aerobic and microaerobic conditions was compared with that of control H. pylori which grew only under microaerobic conditions. They were further identified by amplification of 16S rRNA, vacA alleles, cagA and ureAB genes by PCR. Their susceptibility to current antimicrobials was also examined.

Results:  The strains A and D produced mucoid colonies under aerobic and microaerobic conditions after 24‐hour, exhibiting the typical spiral morphology of H. pylori. The results of urease, catalase and oxidase tests were positive. Sequencing of amplified products showed 99–100% homology with those of the reference H. pylori strains in GenBank. Both strains exhibited resistance to the high concentrations of antimicrobials.

Conclusions:  This study reports the isolation of two mucoid strains of H. pylori with confluent growth under aerobic and microaerobic conditions. It appears that production of exopolysaccharide (EXP) could serve as a physical barrier to reduce oxygen diffusion into the bacterial cell and uptake of antibiotics. EXP protected the mucoid H. pylori isolates against stressful conditions, the result of which could be persistence of bacterial infection in the stomach.
The Use of AlbuMAX II® as a Blood or Serum Alternative for the Culture of Helicobacter pylori
Authors: Hutton Melanie L. , Kaparakis‐Liaskos Maria , Ferrero Richard L.
Published: January 2012

Background:  Growth of Helicobacter pyloriin vitro depends on supplementation of the medium with blood or serum. However, these supplements often require frozen storage and can show batch‐to‐batch variation, resulting in differences in bacterial growth. In this study, we introduce the use of a commercially available, lipid‐rich supplement called AlbuMAX II® (Gibco BRL, Grand Island, NY, USA) for use as a serum/blood replacement for H. pylori culture.

Materials and Methods:  The growth of H. pylori on solid and liquid media was examined by comparing growth after supplementation with horse blood, fetal calf serum, β‐cyclodextrin or AlbuMAX II® (Gibco BRL). Human gastric adenocarcinoma (AGS) cellular responses to H. pylori were measured by NF‐κB luciferase assays and IL‐8 ELISA.

Results:  We show that the growth of H. pylori on both solid and liquid media containing AlbuMAX II® (Gibco BRL) were comparable to levels obtained on blood agar or liquid media supplemented with serum. Growth was consistently higher in media supplemented with AlbuMAX II® (Gibco BRL) than media containing β‐cyclodextrin. Furthermore, bacteria grown in AlbuMAX II® (Gibco BRL) induced proinflammatory responses in AGS cells.

Conclusions:  AlbuMAX II® (Gibco BRL) can be used as a serum/blood replacement for the cultivation of H. pylori in solid and liquid media. This medium could be useful for an improved understanding of H. pylori metabolism or for antigen production. Furthermore, AlbuMAX II® (Gibco BRL) may be suitable for use in remote locations, particularly in areas where frozen storage of serum may be a problem.
Contra Fraser on Feminism and Neoliberalism
Authors: Funk Nanette
Published: January 2012

This article is a critical examination of Nancy Fraser's contrast of early second‐wave feminism and contemporary global feminism in “Feminism, Capitalism and the Cunning of History,” (Fraser 2009). Fraser contrasts emancipatory early second‐wave feminism, strongly critical of capitalism, with feminism in the age of neoliberalism as being in a “dangerous liaison” with neoliberalism. I argue that Fraser's historical account of 1970s mainstream second‐wave feminism is inaccurate, that it was not generally anti‐capitalist, critical of the welfare system, or challenging the priority of paid labor. I claim Fraser mistakenly takes a minority feminist position as mainstream. I further argue that Fraser's account of feminism today echoes arguments from James Petras and Henry Veltmeyer (2001) to Hester Eisenstein (2009), but such arguments ignore contemporary feminist minority positions. I challenge Fraser's arguments that feminism legitimates neoliberalism to women, that women's NGOs are simply service‐providers enabling the state to withdraw services, and that criticisms of microcredit lending programs can be generalized into criticisms of women's feminism and women's NGOs today. I argue that these claims are vast over‐generalizations and ignore countertrends. I give empirical evidence to support my objections by considering women's activities in post‐communist European countries, which Fraser discusses.
Shorting Restrictions: Revisiting the 1930s
Authors: Jones Charles M.
Published: January 2012

Several events in the 1930s made shorting more difficult or impossible in the United States. In 1931, the NYSE banned shorting for two days and later prohibited shorting on a downtick. In 1932, brokers needed written authorization before lending a customer's shares, and the U.S. Senate released a list of the biggest short sellers. In 1938, the tick test was tightened. Short interest and securities lending data indicate that each event made shorting more difficult. Average returns associated with the events are significantly positive, consistent with disagreement models. Liquidity is also affected. Recent U.S. regulatory changes echo these earlier restrictions.
Sovereign CDS Spreads, Volatility, and Liquidity: Evidence from 2010 German Short Sale Ban
Authors: Pu Xiaoling , Zhang Jianing
Published: January 2012

The paper examines global impact of 2010 German short sale ban on sovereign credit default swap (CDS) spreads, volatility, and liquidity across 54 countries. We find that CDS spreads continue rising after the ban in the debt crisis region, which suggests that the short selling ban is incapable of suppressing soaring borrowing costs in these countries. However, we find that the ban helps stabilize the CDS market by reducing CDS volatility. The reduction in CDS volatility is greater in the eurozone than that in the non‐eurozone. Furthermore, we find that the CDS market liquidity has been impaired during the ban for the PIIGS (Portugal, Ireland, Italy, Greece, and Spain) countries. In contrast, there are no dramatic changes in the market liquidity for non‐PIIGS eurozone and non‐eurozone samples. The findings suggest that the short sale ban is ineffective to reduce sovereign borrowing costs in the debt crisis region if the underlying economy has not been significantly improved.
The Changes of Fourier Transform Infrared Spectrum in Rat Brain*
Authors: Ke Yong , Li Yang , Wang Zhen‐Yuan
Published: January 2012

Abstract:  Estimation of the time since death (postmortem interval [PMI]) is one of the most difficult problems in forensic investigations, and many methods currently are utilized to estimate the PMI. The goal of this study was to investigate the changes of attenuated total reflection‐Fourier transform infrared (ATR‐FTIR) spectra of rat brain from postmortem time 0–144 h. The intensity ratios of major absorbance bands were examined (I1066/I1392, I1168/I1392, I1234/I1454, I1301/I1392, I1647/I2956, I2921/I2850, and I1647/I1539). The spectra of rat brain displayed prominent changes with increasing PMI. The band at 2871 and 1737 per cm became weak with the time increasing and even disappeared at postmortem 96 and 72 h, respectively. A close linear correlation was shown between the relative absorption intensity and the PMI, and the I1234/I1454 offered a stronger correlation (r = 0.973). Our results indicate that ATR‐FTIR spectroscopy may be a useful technique for estimating the PMI.
Dilated cardiomyopathy in a spider monkey (Ateles paniscus)
Authors: Koenhemsi Lora , Gönül Remzi , Erdoğan Özge , Sennazli Gülbin , Uysal Abdulkadir
Published: January 2012

Background  A spider monkey with severe dyspnea was referred to our clinic.

Methods and Results  Radiographs revealed an enlarged cardiac silhouette. Ventricular tachycardia and ST segment depression were also diagnosed after an ECG. These findings coupled with the postmortem examination confirmed dilatative cardiomyopathy.

Conclusions  This case is worthy of presentation since dilatative cardiomyopathy has been rarely encountered in spider monkeys.
Surgical Management of Ischemic Priapism
Authors: Burnett Arthur L.
Published: January 2012

Introduction

Surgery is a mainstay in the management of ischemic priapism. The surgical armamentarium for this condition has recently been expanded with the introduction of several innovative procedures.

Aim

To review surgical procedures offered in the treatment of ischemic priapism and present a rational framework for their use.

Methods

Medline searches through July 2010 were conducted using the terms priapism, surgery, shunt, and prosthesis.

Main Outcome Measure

Expert opinion was based on review of the medical literature related to this subject matter.

Results

A host of surgical procedures exist to address the genital complications of both acute presentations of ischemic priapism and its non-acute pathologic sequelae, which include penile deformities and erectile dysfunction. For the former, the intervention is used principally in an emergent context with the intention to relieve the acute pathologic effects of the condition and preserve erectile function. For the latter, the intervention is aimed generally toward restoring anatomic normalcy and the functional ability to perform sexual intercourse. A rational framework for surgical management, based on the circumstances of the clinical presentation, is described.

Conclusions

The surgical management for ischemic priapism has evolved with the application of a host of surgical procedures. These procedures address acute and non-acute genital complications of the condition and are intended to retain or restore sexual ability effectively and safely. They can be applied using a rational clinical management framework.
Groundwater Biofilm Dynamics Grown In Situ Along a Nutrient Gradient
Authors: Williamson Wendy M. , Close Murray E. , Leonard Margaret M. , Webber Judith B. , Lin Susan
Published: January 2012

This paper describes the in situ response of groundwater biofilms in an alluvial gravel aquifer system on the Canterbury Plains, New Zealand. Biofilms were developed on aquifer gravel, encased in fine mesh bags and suspended in protective columns in monitoring wells for at least 20 weeks. Four sites were selected in the same groundwater system where previous analyses indicated a gradient of increasing nitrate down the hydraulic gradient from Sites 1 to 4. Measurements during the current study classified the groundwater as oligotrophic. Biofilm responses to the nutrient gradients were assessed using bioassays, with biomass determined using protein and cellular and nucleic acid staining and biofilm activity using enzyme assays for lipid, carbohydrate, phosphate metabolism, and cell viability. In general, biofilm activity decreased as nitrate levels increased from Sites 1 to 4, with the opposite relationship for carbon and phosphorus concentrations. These results showed that the groundwater system supported biofilm growth and that the upper catchment supported efficient and productive biofilms (high ratio of activity per unit biomass).
Green tea polyphenol epigallocatechin‐3‐gallate enhances 5‐fluorouracil‐induced cell growth inhibition of hepatocellular carcinoma cells
Authors: Yang Xue‐Wei , Wang Xiao‐Li , Cao Liang‐Qi , Jiang Xiao‐Feng , Peng He‐Ping , Lin Shao‐Mang , Xue Ping , Chen De
Published: January 2012

Aim:  5‐Fluorouracil (5‐FU) is one of the most commonly used chemotherapeutic drugs. Resistance to 5‐FU is a major cause of chemotherapy failure in advanced‐stage hepatocellular carcinoma (HCC). Green tea polyphenol Epigallocatechin‐3‐gallate (EGCG) plays a critical role in growth inhibition and apoptotic induction in HCC cell lines. The aim of this study is to investigate whether EGCG can enhance 5‐FU‐induced cell growth inhibition and to explore its potential mechanisms.

Methods:  3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay was used to evaluate cell growth. Western blotting analysis was performed to detect the proteins expression in Hep3B cells. Small interfering RNA was used to suppress cyclooxygenase‐2 (COX‐2) expression. Furthermore, enzyme linked immunosorbent assay was used to test the prostaglandin E2 (PGE2) production in cell cultures.

Results:  Epigallocatechin‐3‐gallate augmented the anti‐tumor effect of 5‐FU in Hep3B cells. Significant difference was observed between the treated groups and the control group (P < 0.05). EGCG (its concentrations at over 5 µmol/L) combined with 5‐FU presented a synergic effect. Furthermore, the combination of EGCG and 5‐FU abrogated the COX‐2 overexpression and PGE2 secretion induced by 5‐FU. The upregulation of COX‐2 expression decreased the phosphorylation of Akt (Thr308) expression. These appeared to be followed by the AMPK hyperactivation.

Conclusion:  Epigallocatechin‐3‐gallate sensitizes HCC cells to 5‐FU antitumor activity, and the combination of EGCG and 5‐FU exhibits synergism in chemo‐resistant cancer cells. The results suggest potential novel therapies for the treatment of advanced‐stage liver cancer.
Toward Time-Dependent Robustness Metrics
Authors: Du Xiaoping
Published: January 2012

Quality characteristics are often treated as constants in robust design, while many of them actually vary over time. It is desirable to define new robustness metrics for time-dependent quality characteristics. This work shows that using the static robustness metrics for time-dependent quality characteristics may lead to erroneous design results. We then propose criteria of new robustness metrics for time-dependent quality characteristics. Instead of using an expected point quality loss over the time period of interest, we use the expectation of the maximal quality loss over the time period to quantify the robustness for time-dependent quality characteristics. Through a four-bar function generator mechanism synthesis, we demonstrate that the new robustness metrics can capture the full information of robustness of a time-dependent quality characteristic over a time interval. The new robustness metrics can then be used as objective functions for time-dependent robust design optimization.
NEW: Network-Enabled Wisdom in Biology, Medicine, and Health Care
Authors: Schadt Eric E. , Björkegren Johan L. M.
Published: January 2012

Multidimensional networks are required to model human physiology in general and to identify key drivers of pathology in individual patients.
Synthesis of Mixed Rb‐Zn Ferrites by Novel Solution Combustion Method and Investigation on Their Microstructural Properties
Authors: Gupta Manik , Randhawa Balwinder S.
Published: January 2012

Microstructural studies have been made on mixed rubidium nanoferrites of varying compositions, that is,
Rb0.5−x/2ZnxMn0.05Fe2.45−x/2O4 prepared by solution combustion method from stoichiometric aqueous solutions of metal nitrates and ethylene glycol. The combustion method is rapid and approach direct conversion from the molecular mixture of precursor solution to the fine nanoparticles of oxide product. The ferrites obtained have been characterized by powder XRD, transmission electron microscopy, and EDXRF studies. Powder X‐ray diffraction analysis shows the formation of single‐phase structure. The lattice parameter “a” has been found to increase with increasing Zn content. Both theoretical and experimental densities show a decreasing trend with decrease in molecular weight. The calculated value of the porosity has been found to be quite low which is a characteristic requirement of good‐quality ferrite materials. TEM micrographs indicate the formation of nanosized ferrite particles which is in agreement with the size calculated from XRD data.
Acculturative Stress and School Belonging Among Latino Youth
Authors: Roche Cathy , Kuperminc Gabriel P.
Published: January 2012

Dimensions of acculturative stress and their implications for school belonging and achievement were examined among 199 Latino middle-school students. The proposed model hypothesized that school belonging would mediate the association between acculturative stress dimensions and low school achievement. Eighty percent youth of the sample were immigrants, 73% had Mexican origins, 57% were girls, and the mean age of the participants was 13.6 years. A factor analysis yielded two dimensions of acculturative stress: discrimination stress and immigration-related stress. Immigration-related stress was associated with age of immigration, but discrimination stress was not. Findings supported the hypothesis that lack of school belonging may be a mechanism by which discrimination stress, but not immigration-related stress, decreases school performance among Latino youth.
Dilemmas, diagnosis and de-stigmatization: Parental perspectives on the diagnosis of autism spectrum disorders
Authors: Russell Ginny , Norwich Brahm
Published: January 2012

Many children who display autistic behaviours at clinical levels do not receive a formal diagnosis. This study used qualitative methods to examine parental influence in pursuing or avoiding a diagnosis of autism spectrum disorder (ASD). The aim was to explore the function of ASD diagnosis for parents, and examine whether a diagnosis affected how parents perceived ASD. Seventeen parents participated in in-depth semi-structured interviews, which were analyzed using thematic and grounded theory approaches. Data analysis revealed dilemmas faced by parents: whether to act to retain the ‘normal’ status of the child or to ‘normalize’ the child through diagnosis and subsequent remediation. Parents who had received an ASD diagnosis for their children became proactive in trying to reduce stigmatization of ASD more widely, and in some cases actively advocating ASD diagnosis to other parents. Thus their actions may make it more likely that others will opt for diagnosis in the future.
The construction of ethnic identity: Insights from identity process theory
Authors: Jaspal Rusi , Cinnirella Marco
Published: January 2012

Ethnicity has received much empirical and theoretical attention in the social sciences. Yet, it has scarcely been explored in terms of its relationship with the motivational principles of identity. Here it is argued that there is much heuristic and predictive value in applying identity process theory (IPT), a socio-psychological model of identity threat, to the substantive literature on ethnicity. The paper explores the potential psychological benefits of ethnic identification. Key theoretical strands from anthropology and sociology, such as the ‘relational self’ in ethnic identification, are discussed in relation to IPT. The intergroup dimension of ethnic identification is explored through the discussion of ethnic ‘boundaries’. Finally, the paper discusses the construct of ‘hybridization’ in relation to social psychology. This paper attempts to reconcile psychological and sociological perspectives on ethnic identification, advocating a multi-methodological approach. Key theoretical points are outlined in the form of testable hypotheses which are open to empirical exploration.
Possible role of EMID2 on nasal polyps pathogenesis in Korean asthma patients
Authors: Pasaje Charisse Flerida Arnejo , Bae Joon Seol , Park Byung-Lae , Cheong Hyun Sub , Kim Jeong-Hyun , Jang An-Soo , Uh Soo-Taek , Park Choon-Sik , Shin Hyoung Doo
Published: January 2012

Background

Since subepithelial fibrosis and protruded extracellular matrix are among the histological characteristics of polyps, the emilin/multimerin domain-containing protein 2 (EMID2) gene is speculated to be involved in the presence of nasal polyps in asthma and aspirin-hypersensitive patients.

Methods

To investigate the association between EMID2 and nasal polyposis, 49 single-nucleotide polymorphisms (SNPs) were genotyped in 467 asthmatics of Korean ancestry who were stratified further into 114 aspirin exacerbated respiratory disease (AERD) and 353 aspirin-tolerant asthma (ATA) subgroups. From pairwise comparison of the genotyped polymorphisms, 14 major haplotypes (frequency > 0.05) were inferred and selected for association analysis. Differences in the frequency distribution of EMID2 variations between polyp-positive cases and polyp-negative controls were determined using logistic analyses.

Results

Initially, 13 EMID2 variants were significantly associated with the presence of nasal polyps in the overall asthma group (P = 0.0008-0.05, OR = 0.54-1.32 using various modes of genetic inheritance). Although association signals from 12 variants disappeared after multiple testing corrections, the relationship between EMID2_BL1_ht2 and nasal polyposis remained significant via a codominant mechanism (P

corr
= 0.03). On the other hand, the nominal associations observed between the genetic variants tested for the presence of nasal polyps in AERD (P = 0.003-0.05, OR = 0.25-1.82) and ATA (P = 0.01-0.04, OR = 0.46-10.96) subgroups disappeared after multiple comparisons, suggesting lack of associations.

Conclusions

These preliminary findings suggest that EMID2_BL1_ht2 may be a susceptibility marker of inflammation of the nasal passages among Korean asthma patients.
Active living neighborhoods: is neighborhood walkability a key element for Belgian adolescents?
Authors: De Meester Femke , Van Dyck Delfien , De Bourdeaudhuij Ilse , Deforche Benedicte , Sallis James F , Cardon Greet
Published: January 2012

Background

In adult research, neighborhood walkability has been acknowledged as an important construct among the built environmental correlates of physical activity. Research into this association has only recently been extended to adolescents and the current empirical evidence is not consistent. This study investigated whether neighborhood walkability and neighborhood socioeconomic status (SES) are associated with physical activity among Belgian adolescents and whether the association between neighborhood walkability and physical activity is moderated by neighborhood SES and gender.

Methods

In Ghent (Belgium), 32 neighborhoods were selected based on GIS-based walkability and SES derived from census data. In total, 637 adolescents (aged 13-15 year, 49.6% male) participated in the study. Physical activity was assessed using accelerometers and the Flemish Physical Activity Questionnaire. To analyze the associations between neighborhood walkability, neighborhood SES and individual physical activity, multivariate multi-level regression analyses were conducted.

Results

Only in low-SES neighborhoods, neighborhood walkability was positively associated with accelerometer-based moderate to vigorous physical activity and the average activity level expressed in counts/minute. For active transport to and from school, cycling for transport during leisure time and sport during leisure time no association with neighborhood walkability nor, with neighborhood SES was found. For walking for transport during leisure time a negative association with neighborhood SES was found. Gender did not moderate the associations of neighborhood walkability and SES with adolescent physical activity.

Conclusions

Neighborhood walkability was related to accelerometer-based physical activity only among adolescent boys and girls living in low-SES neighborhoods. The relation of built environment to adolescent physical activity may depend on the context.
Rician nonlocal means denoising for MR images using nonparametric principal component analysis
Authors: Kim Dong Wook , Kim Chansoo , Kim Dong Hee , Lim Dong Hoon
Published: January 2012

Denoising is always a challenging problem in magnetic resonance imaging (MRI) and is important for clinical diagnosis and computerized analysis, such as tissue classification and segmentation. The noise in MRI has a Rician distribution. Unlike additive Gaussian noise, Rician noise is signal dependent, and separating the signal from the noise is a difficult task. In this paper, we propose a useful alternative of the nonlocal mean (NLM) filter that uses nonparametric principal component analysis (NPCA) for Rician noise reduction in MR images. This alternative is called the NPCA-NLM filter, and it results in improved accuracy and computational performance. We present an applicable method for estimating smoothing kernel width parameters for a much larger set of images and demonstrate that the number of principal components for NPCA is robust to variations in the noise as well as in images. Finally, we investigate the performance of the proposed filter with the standard NLM filter and the PCA-NLM filter on MR images corrupted with various levels of Rician noise. The experimental results indicate that the NPCA-NLM filter is the most robust to variations in images, and shows good performance at all noise levels tested.
Solid angles and the impact of receiver-array geometry on microseismic moment-tensor inversion
Authors: Eaton David W. , Forouhideh Farshid
Published: January 2012

Seismic moment tensors provide a concise mathematical representation of point sources that can be used to characterize microseismic focal mechanisms. After correction for propagation effects, the six independent components of a moment tensor can be found by least-squares inversion based on P- and/or S-waveform (or spectral) amplitudes observed at different directions from the source. Using synthetic waveform data, we investigated geometrical factors that affect the reliability of such inversions. We demonstrated that the solid angle subtended by the receiver array, as viewed from the source location, plays a fundamental role in the stability of the inversion. In particular, the condition number of the generalized inverse scales approximately inversely with the solid angle, implying that for a solid angle of zero (as is the case for a single vertical borehole) the inversion is ill-conditioned. The presence of random noise alsohas a significant effect on the inversion results; our results showed that the signal-to-noise ratio (S/N) for reliable inversion scales approximately as the square root of the condition number. Taken together with geometrical considerations, we found that a [Formula: see text] is generally needed to obtain reliable inversion results for the full moment tensor under certain microseismic acquisition scenarios that include dual observation wells or surface star pattern. Our numerical tests indicated that least-squares moment-tensor solutions obtained under nonideal conditions are biased toward limited regions of the full parameter space. In particular, random noise introduces a bias toward volumetric source types, whereas ill-conditioned inversions may exhibit bias toward poorly resolved eigenvector(s) of the inversion matrix. Possible strategies to improve the reliability of moment-tensor inversion include ensuring a nonzero solid-angle aperture by using multiple observation wells, and/or incorporating other types of data such as a priori knowledge of fracture orientation.
The Effects of Deleterious Mutations on Evolution at Linked Sites
Authors: Charlesworth Brian
Published: January 2012

The process of evolution at a given site in the genome can be influenced by the action of selection at other sites, especially when these are closely linked to it. Such selection reduces the effective population size experienced by the site in question (the Hill–Robertson effect), reducing the level of variability and the efficacy of selection. In particular, deleterious variants are continually being produced by mutation and then eliminated by selection at sites throughout the genome. The resulting reduction in variability at linked neutral or nearly neutral sites can be predicted from the theory of background selection, which assumes that deleterious mutations have such large effects that their behavior in the population is effectively deterministic. More weakly selected mutations can accumulate by Muller’s ratchet after a shutdown of recombination, as in an evolving Y chromosome. Many functionally significant sites are probably so weakly selected that Hill–Robertson interference undermines the effective strength of selection upon them, when recombination is rare or absent. This leads to large departures from deterministic equilibrium and smaller effects on linked neutral sites than under background selection or Muller’s ratchet. Evidence is discussed that is consistent with the action of these processes in shaping genome-wide patterns of variation and evolution.
Pediatric Self-management: A Framework for Research, Practice, and Policy
Authors: Modi Avani C. , Pai Ahna L. , Hommel Kevin A. , Hood Korey K. , Cortina Sandra , Hilliard Marisa E. , Guilfoyle Shanna M. , Gray Wendy N. , Drotar Dennis
Published: January 2012

Self-management of chronic pediatric conditions is a formidable challenge for patients, families, and clinicians, with research demonstrating a high prevalence of poor self-management and nonadherence across pediatric conditions. Nevertheless, effective self-management is necessary to maximize treatment efficacy and clinical outcomes and to reduce unnecessary health care utilization and costs. However, this complex behavior is poorly understood as a result of insufficient definitions, reliance on condition-specific and/or adult models of self-management, failure to consider the multitude of factors that influence patient self-management behavior, and lack of synthesis of research, clinical practice, and policy implications. To address this need, we present a comprehensive conceptual model of pediatric self-management that articulates the individual, family, community, and health care system level influences that impact self-management behavior through cognitive, emotional, and social processes. This model further describes the relationship among self-management, adherence, and outcomes at both the patient and system level. Implications for research, clinical practice, and health care policy concerning pediatric chronic care are emphasized with a particular focus on modifiable influences, evidence-based targets for intervention, and the role of clinicians in the provision of self-management support. We anticipate that this unified conceptual approach will equip stakeholders in pediatric health care to (1) develop evidence-based interventions to improve self-management, (2) design programs aimed at preventing the development of poor self-management behaviors, and (3) inform health care policy that will ultimately improve the health and psychosocial outcomes of children with chronic conditions.
Drinking Frequency as a Brief Screen for Adolescent Alcohol Problems
Authors: Chung Tammy , Smith Gregory T. , Donovan John E. , Windle Michael , Faden Vivian B. , Chen Chiung M. , Martin Christopher S.
Published: January 2012

OBJECTIVE:

Routine alcohol screening of adolescents in pediatric settings is recommended, and could be facilitated by a very brief empirically validated alcohol screen based on alcohol consumption. This study used national sample data to test the screening performance of 3 alcohol consumption items (ie, frequency of use in the past year, quantity per occasion, frequency of heavy episodic drinking) in identifying youth with alcohol-related problems.

METHODS:

Data were from youth aged 12 to 18 participating in the annual National Survey on Drug Use and Health from 2000 to 2007. The screening performance of 3 alcohol consumption items was tested, by age and gender, against 2 outcomes: any Diagnostic and Statistical Manual, Fourth Edition alcohol use disorder symptom (“moderate”-risk outcome), and a diagnosis of Diagnostic and Statistical Manual, Fourth Edition alcohol dependence (“high”-risk outcome).

RESULTS:

Prevalence of the 2 outcomes increased with age: any alcohol use disorder symptom ranged from 1.4% to 29.2%; alcohol dependence ranged from 0.2% to 5.3%. Frequency of drinking had higher sensitivity and specificity in identifying both outcomes, compared with quantity per occasion and heavy episodic drinking frequency. For both outcomes, results indicate the utility of similar cut points for drinking frequency for males and females at each age. Age-specific frequency cut points, however, are recommended for both moderate- and high-risk outcomes to maximize screening performance.

CONCLUSIONS:

Drinking frequency provides an empirically supported brief screen to efficiently identify youth with alcohol-related problems.
Modern radiotherapy after breast-conserving surgery
Authors: Polgár Csaba , Major Tibor , Fodor János
Published: January 2012

In the last four decades breast-conserving surgery followed by whole breast irradiation has become the standard of care for the treatment of early-stage (0-I-II) breast carcinoma. With the advent of breast-screening, incidence of breast carcinomas with more favorable prognostic characteristics has increased significantly. This change in the prognostic profile of newly diagnosed breast cancers opened a new horizon for clinical research seeking for individual risk-adapted protocols of breast cancer radiotherapy. Several groups have been tested the efficacy of accelerated (partial or whole) breast irradiation, which has become the new treatment paradigm in the radiotherapy of early-stage breast cancers. Furthermore, others have attempted to identify subgroups of patients for whom radiotherapy after breast-conserving surgery could be safely omitted. Recently molecular gene expression assays have emerged as promising prognostic and predictive markers for local recurrence. This article reviews the results of these studies focusing on individual risk-adapted radiotherapy after breast-conserving surgery for patients with early-stage breast carcinoma. Orv. Hetil., 2012, 153, 45–55.
Species Diversity of Carp, Cyprinus Carpio (Cypriniformes, Cyprinidae), Parasites in Some Cultivation Regions
Authors: Davydov O. , Lysenko V. , Kurovskaya L.
Published: January 2012

Species Diversity of Carp, Cyprinus Carpio (Cypriniformes, Cyprinidae), Parasites in Some Cultivation Regions

Zoogeographical comparison for species diversity of carp parasites in different cultivation regions including aquatic ecosystems of Ukraine, Uzbekistan, Russia, and Vietnam was carried out. Totally, 160 parasitic species were recorded in carp within these regions. Parasitic species with direct and complex life cycles important in epizootic, veterinary, and health areas were registered.
Cancer statistics, 2012
Authors: Siegel Rebecca , Naishadham Deepa , Jemal Ahmedin
Published: January 2012

Each year, the American Cancer Society estimates the numbers of new cancer cases and deaths expected in the United States in the current year and compiles the most recent data on cancer incidence, mortality, and survival based on incidence data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries and mortality data from the National Center for Health Statistics. A total of 1,638,910 new cancer cases and 577,190 deaths from cancer are projected to occur in the United States in 2012. During the most recent 5 years for which there are data (2004‐2008), overall cancer incidence rates declined slightly in men (by 0.6% per year) and were stable in women, while cancer death rates decreased by 1.8% per year in men and by 1.6% per year in women. Over the past 10 years of available data (1999‐2008), cancer death rates have declined by more than 1% per year in men and women of every racial/ethnic group with the exception of American Indians/Alaska Natives, among whom rates have remained stable. The most rapid declines in death rates occurred among African American and Hispanic men (2.4% and 2.3% per year, respectively). Death rates continue to decline for all 4 major cancer sites (lung, colorectum, breast, and prostate), with lung cancer accounting for almost 40% of the total decline in men and breast cancer accounting for 34% of the total decline in women. The reduction in overall cancer death rates since 1990 in men and 1991 in women translates to the avoidance of about 1,024,400 deaths from cancer. Further progress can be accelerated by applying existing cancer control knowledge across all segments of the population, with an emphasis on those groups in the lowest socioeconomic bracket. CA Cancer J Clin 2012. © 2012 American Cancer Society.
An Emerging Problem in Clinical Practice: How to Approach Acute Psychosis
Authors: Markoula Sofia , Chatzistefanidis Dimitrios , Konitsiotis Spyridon , Kyritsis Athanassios P.
Published: January 2012

Limbic encephalitis (LE) is rare, presents with memory impairment, seizures and behavioral disorder. We present a 44-year-old female with an agitation-depressive disorder associated with delusions and hallucinations, admitted to our hospital with the diagnosis of psychosis. A computed tomography (CT) scan of the brain and lumbar puncture on admission were normal. Because of clinical deterioration and addition of seizures in the clinical picture, further workup with serum and repeat cerebrospinal fluid studies, magnetic resonance imaging (MRI), and electroencephalogram disclosed a lesion in the left medial temporal lobe consistent with LE. The patient was treated symptomatically with antidepressive, antipsychotic and anticonvulsant drugs. Aggressive diagnostic tests for the presence of an occult cancer were negative. An 8-year follow up has not revealed a tumor to support a paraneoplasmatic origin of LE. This case, initially diagnosed and treated as psychosis, is a case of non-paraneoplasmatic, non-infective LE, probably caused by an autoimmune mechanism.
The Concentration-Compactness Principle in the Calculus of Variations. The limit case, Part 1
Authors: Lions Pierre-Louis
Published: January 2012

After the study made in the locally compact case for variational problems with some translation invariance, we investigate here the variational problems (with constraints) for example in

\mathbb R^N

where the invariance of

\mathbb R^N

by the group of dilatations creates some possible loss of compactness. This is for example the case for all the problems associated with the determination of extremal functions in functional inequalities (like for example the Sobolev inequalities). We show here how the concentration-compactness principle has to be modified in order to be able to treat this class of problems and we present applications to Functional Analysis, Mathematical Physics, Differential Geometry and Harmonic Analysis.
Closed system isolation and scalable expansion of human placental mesenchymal stem cells
Authors: Timmins N.E. , Kiel M. , Günther M. , Heazlewood C. , Doran M.R. , Brooke G. , Atkinson K.
Published: January 2012

Mesenchymal stem cells (MSC) are emerging as a leading cellular therapy for a number of diseases. However, for such treatments to become available as a routine therapeutic option, efficient and cost‐effective means for industrial manufacture of MSC are required. At present, clinical grade MSC are manufactured through a process of manual cell culture in specialized cGMP facilities. This process is open, extremely labor intensive, costly, and impractical for anything more than a small number of patients. While it has been shown that MSC can be cultivated in stirred bioreactor systems using microcarriers, providing a route to process scale‐up, the degree of numerical expansion achieved has generally been limited. Furthermore, little attention has been given to the issue of primary cell isolation from complex tissues such as placenta. In this article we describe the initial development of a closed process for bulk isolation of MSC from human placenta, and subsequent cultivation on microcarriers in scalable single‐use bioreactor systems. Based on our initial data, we estimate that a single placenta may be sufficient to produce over 7,000 doses of therapeutic MSC using a large‐scale process. Biotechnol. Bioeng. 2012; 109:1817–1826. © 2012 Wiley Periodicals, Inc.
The effect of surface charge property on Escherichia coli initial adhesion and subsequent biofilm formation
Authors: Terada Akihiko , Okuyama Keisuke , Nishikawa Megumi , Tsuneda Satoshi , Hosomi Masaaki
Published: January 2012

Polyethylene (PE) sheets were modified by radiation‐induced graft polymerization (RIGP) of an epoxy‐group containing monomer glycidyl methacrylate (GMA). The epoxy group of GMA was opened by introducing sodium sulfite (SS) and diethylamine (DEA) as representatives of negatively and positively charged functional groups, respectively. These modified surfaces by RIGP, termed GMA, SS, and DEA sheets, were investigated to elucidate their effects on initial adhesion and subsequent biofilm formation of Escherichia coli. Initial adhesion test revealed that E. coli density and viability were governed by sheet surface electrostatic property: E. coli cell density on the DEA sheet was 23 times higher than that on the SS sheet after 8 h incubation. The viability of E. coli cells dramatically decreased after contact with the DEA sheet, but remained high on the SS sheet. E. coli biofilm structure on the DEA sheet was dense, homogeneous, and uniform, with biomass higher than that of the GMA and SS sheets by factors of 14.0 and 37.5, respectively. On the contrary, biofilm structure on the SS sheet was sparse, heterogeneous, and mushroom‐shaped. More than 40% of E. coli biofilm on the DEA sheet was retained under a high liquid shear force condition (5,000 s−1), whereas 97% and 100% of biofilms on the GMA and SS sheets were sloughed, indicating that E. coli biofilm robustness depends on surface charge property of the substratum. This suggests that substratum surface fabrication by RIGP may enhance or suppress biofilm formation, a finding with potentially important practical implications. Biotechnol. Bioeng. 2012; 109:1745–1754. © 2012 Wiley Periodicals, Inc.
A sensitive capillary GC‐MS method for analysis of topiramate from plasma obtained from single‐dose studies
Authors: Conway Jeannine M. , Birnbaum Angela K. , Marino Susan E. , Cloyd James C. , Remmel Rory P.
Published: January 2012

Topiramate (Topamax®) is an antiepileptic medication used as adjunctive and monotherapy in patients with epilepsy and for migraine prophylaxis. A GC‐MS assay was developed that was capable of detecting topiramate plasma concentrations following a single rectal or oral dose administration. Topiramate plasma samples were prepared by solid‐phase extraction and were quantified by GC‐MS analysis. The topiramate standard curves were split from 0.1 to 4 µg/mL and from 4 to 40 µg/mL in order to give a more accurate determination of the topiramate concentration. The accuracy of the standards ranged from 94.6 to 107.3% and the precision (%CV) ranged from 1.0 to 5.3% for both curves at all concentrations. The %CV for quality controls was <7.6%. The assay is both accurate and precise and will be used to complete future pharmacokinetic studies. Copyright © 2012 John Wiley & Sons, Ltd.