bluuebunny/crossref_metadata_2025 huggingface dataset:
Leucine-rich repeat kinase 2 and alpha-synuclein: intersecting pathways in the pathogenesis of Parkinson's disease?
Authors: Greggio Elisa , Bisaglia Marco , Civiero Laura , Bubacco Luigi
Published: February 2011

Although Parkinson's disease (PD) is generally a sporadic neurological disorder, the discovery of monogenic, hereditable forms of the disease has been crucial in delineating the molecular pathways that lead to this pathology. Genes responsible for familial PD can be ascribed to two categories based both on their mode of inheritance and their suggested biological function. Mutations inparkin,PINK1andDJ-1cause of recessive Parkinsonism, with a variable pathology often lacking the characteristic Lewy bodies (LBs) in the surviving neurons. Intriguingly, recent findings highlight a converging role of all these genes in mitochondria function, suggesting a common molecular pathway for recessive Parkinsonism. Mutations in a second group of genes, encoding alpha-synuclein (α-syn) and LRRK2, are transmitted in a dominant fashion and generally lead to LB pathology, with α-syn being the major component of these proteinaceous aggregates. In experimental systems, overexpression of mutant proteins is toxic, as predicted for dominant mutations, but the normal function of both proteins is still elusive. The fact that α-syn is heavily phosphorylated in LBs and that LRRK2 is a protein kinase, suggests that a link, not necessarily direct, exists between the two. What are the experimental data supporting a common molecular pathway for dominant PD genes? Do α-syn and LRRK2 target common molecules? Does LRRK2 act upstream of α-syn? In this review we will try to address these of questions based on the recent findings available in the literature.
Integration of lipidomics and transcriptomics data towards a systems biology model of sphingolipid metabolism
Authors: Gupta Shakti , Maurya Mano R , Merrill Jr Alfred H , Glass Christopher K , Subramaniam Shankar
Published: February 2011

Background

Sphingolipids play important roles in cell structure and function as well as in the pathophysiology of many diseases. Many of the intermediates of sphingolipid biosynthesis are highly bioactive and sometimes have antagonistic activities, for example, ceramide promotes apoptosis whereas sphingosine-1-phosphate can inhibit apoptosis and induce cell growth; therefore, quantification of the metabolites and modeling of the sphingolipid network is imperative for an understanding of sphingolipid biology.

Results

In this direction, the LIPID MAPS Consortium is developing methods to quantitate the sphingolipid metabolites in mammalian cells and is investigating their application to studies of the activation of the RAW264.7 macrophage cell by a chemically defined endotoxin, Kdo2-Lipid A. Herein, we describe a model for the C16-branch of sphingolipid metabolism (i.e., for ceramides with palmitate as the N-acyl-linked fatty acid, which is selected because it is a major subspecies for all categories of complex sphingolipids in RAW264.7 cells) integrating lipidomics and transcriptomics data and using a two-step matrix-based approach to estimate the rate constants from experimental data. The rate constants obtained from the first step are further refined using generalized constrained nonlinear optimization. The resulting model fits the experimental data for all species. The robustness of the model is validated through parametric sensitivity analysis.

Conclusions

A quantitative model of the sphigolipid pathway is developed by integrating metabolomics and transcriptomics data with legacy knowledge. The model could be used to design experimental studies of how genetic and pharmacological perturbations alter the flux through this important lipid biosynthetic pathway.
Unsuspected pulmonary alveolar proteinosis in a patient with acquired immunodeficiency syndrome: a case report
Authors: Tejwani Dimple , DeLaCruz Angel E , Niazi Masooma , Diaz-Fuentes Gilda
Published: February 2011

Introduction

Diffuse lung infiltrates are a common finding in patients with acquired immunodeficiency syndrome and causes range from infectious processes to malignancies or interstitial lung diseases. Pulmonary alveolar proteinosis is a rare pulmonary disorder rarely reported in patients infected with human immunodeficiency virus. Secondary pulmonary alveolar proteinosis is associated with conditions involving functional impairment or reduced numbers of alveolar macrophages. It can be caused by hematologic malignancies, inhalation of toxic dust, fumes or gases, infectious or pharmacologic immunosuppression, or lysinuric protein intolerance.

Case presentation

A 42-year-old African American man infected with human immunodeficiency virus was admitted with chronic respiratory symptoms and diffuse pulmonary infiltrates. Chest computed tomography revealed bilateral spontaneous pneumothoraces, for which he required bilateral chest tubes. Initial laboratory investigations did not reveal any contributory conditions. Histological examination of a lung biopsy taken during video-assisted thoracoscopy showed pulmonary alveolar proteinosis concurrent with cytomegalovirus pneumonitis. After ganciclovir treatment, our patient showed radiologic and clinical improvement.

Conclusion

The differential diagnosis for patients with immunosuppression and lung infiltrates requires extensive investigations. As pulmonary alveolar proteinosis is rare, the diagnosis can be easily missed. Our case highlights the importance of invasive investigations and histology in the management of patients infected with human immunodeficiency virus and pulmonary disease who do not respond to empiric therapy.
Budd-Chiari syndrome in a 25-year-old woman with Behçet's disease: a case report and review of the literature
Authors: Carvalho Daniela T , Oikawa Fernando T , Matsuda Nilce M , Évora Paulo RB , Yamada Alice T
Published: February 2011

Introduction

The risk that patients with Behçet's disease will develop thrombotic complications has been previously described. Although it is distributed worldwide, Behçet's disease is rare in the Americas and Europe. Even though the pathogenic mechanisms of vascular complications of Budd-Chiari syndrome in patients with Behçet's disease are unknown, severe vascular complications of Budd-Chiari syndrome associated with Behçet's disease seem to affect mainly young men.

The risk that patients with Behçet's disease will develop thrombotic complications has been previously described. Although it is distributed worldwide, Behçet's disease is rare in the Americas and Europe. Even though the pathogenic mechanisms of vascular complications of Budd-Chiari syndrome in patients with Behçet's disease are unknown, severe vascular complications of Budd-Chiari syndrome associated with Behçet's disease seem to affect mainly young men.

Case presentation

We report a case of Budd-Chiari syndrome, a severe vascular complication that developed in a 25-year-old Afro-Brazilian woman with Behçet's disease.

Conclusion

Severe vascular complications of Budd-Chiari syndrome in patients with Behçet's disease are much more common in young adult male patients; we present a rare case of Budd-Chiari syndrome in a young Afro-Brazilian woman with Behçet's disease.
Increased interleukin-23 receptor+T cells in peripheral blood mononuclear cells of patients with systemic lupus erythematosus
Authors: Puwipirom Hathaipat , Hirankarn Nattiya , Sodsai Pimpayao , Avihingsanon Yingyos , Wongpiyabovorn Jongkonnee , Palaga Tanapat
Published: February 2011

Introduction

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by production of autoantibodies and immune complex deposition in various organs. Aberrations in the T lymphocyte compartment and dysregulated cytokine production are key features of SLE pathogenesis and disease progression. Recently, the role of the interleukin (IL)-17/IL-23 axis in the pathogenesis of SLE has been reported. IL-23 and IL-23R are essential for expansion of pathogenic IL-17-producing T lymphocytes and have been shown to be important in the pathogenesis of lupus in animal models.

Methods

In this study, the expression of IL-23R and IL-17 in CD4+ and CD8+ T lymphocytes in peripheral blood mononuclear cells (PBMCs) of SLE patients and control subjects were examined by flow cytometry. Twenty-nine SLE patients and 10 control subjects were recruited in this study. Patients were divided into active and inactive groups based on the SLE disease activity index (SLEDAI). As another disease control population, five psoriatic patients were recruited in this study.

Results

Percentages of both IL23R+ CD4+ and IL-23R+ CD8+ T cell subsets were significantly higher in freshly isolated PBMCs from both groups of SLE patients compared to control subjects (P = 0.0021 and P = 0.0006, respectively). In addition, this difference was maintained after ex vivo stimulation with plate-bound anti-CD3/CD28 antibodies (P = 0.007 and P = 0.0019, respectively). When the fold increase in IL-17+ T cells after ex vivo stimulation for three days was compared between patients and controls, SLE patients exhibited significantly higher increases in CD4+ IL-17+ and CD8+ IL-17+ T cells, suggesting that PBMCs from SLE patients promoted the expansion of IL-17-producing T cells upon stimulation more vigorously than control PBMCs. These trends were not observed in psoriasis patients. The correlations between IL-23R+ T cells and IL-17+ T cells and IL-23R+ CD8+ T cells and SLEDAI scores in patients were also found to be statistically significant.

Conclusions

The results of our study confirmed the relevance of the IL-23/IL-17 axis in the pathogenesis of SLE and further highlighted the importance of IL-23R+ T cell subsets in this autoimmune disease.
Quantitative shear wave ultrasound elastography: initial experience in solid breast masses
Authors: Evans Andrew , Whelehan Patsy , Thomson Kim , McLean Denis , Brauer Katrin , Purdie Colin , Jordan Lee , Baker Lee , Thompson Alastair
Published: February 2011

Introduction

Shear wave elastography is a new method of obtaining quantitative tissue elasticity data during breast ultrasound examinations. The aims of this study were (1) to determine the reproducibility of shear wave elastography (2) to correlate the elasticity values of a series of solid breast masses with histological findings and (3) to compare shear wave elastography with greyscale ultrasound for benign/malignant classification.

Methods

Using the Aixplorer® ultrasound system (SuperSonic Imagine, Aix en Provence, France), 53 solid breast lesions were identified in 52 consecutive patients. Two orthogonal elastography images were obtained of each lesion. Observers noted the mean elasticity values in regions of interest (ROI) placed over the stiffest areas on the two elastography images and a mean value was calculated for each lesion. A sub-set of 15 patients had two elastography images obtained by an additional operator. Reproducibility of observations was assessed between (1) two observers analysing the same pair of images and (2) findings from two pairs of images of the same lesion taken by two different operators. All lesions were subjected to percutaneous biopsy. Elastography measurements were correlated with histology results. After preliminary experience with 10 patients a mean elasticity cut off value of 50 kilopascals (kPa) was selected for benign/malignant differentiation. Greyscale images were classified according to the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS). BI-RADS categories 1-3 were taken as benign while BI-RADS categories 4 and 5 were classified as malignant.

Results

Twenty-three benign lesions and 30 cancers were diagnosed on histology. Measurement of mean elasticity yielded an intraclass correlation coefficient of 0.99 for two observers assessing the same pairs of elastography images. Analysis of images taken by two independent operators gave an intraclass correlation coefficient of 0.80. Shear wave elastography versus greyscale BI-RADS performance figures were sensitivity: 97% vs 87%, specificity: 83% vs 78%, positive predictive value (PPV): 88% vs 84%, negative predictive value (NPV): 95% vs 82% and accuracy: 91% vs 83% respectively. These differences were not statistically significant.

Conclusions

Shear wave elastography gives quantitative and reproducible information on solid breast lesions with diagnostic accuracy at least as good as greyscale ultrasound with BI-RADS classification.
Inactivation of FBXW7/hCDC4-β expression by promoter hypermethylation is associated with favorable prognosis in primary breast cancer
Authors: Akhoondi Shahab , Lindström Linda , Widschwendter Martin , Corcoran Martin , Bergh Jonas , Spruck Charles , Grandér Dan , Sangfelt Olle
Published: February 2011

Introduction

Mutational inactivation of the FBXW7/hCDC4 tumor suppressor gene (TSG) is common in many cancer types, but infrequent in breast cancers. This study investigates the presence and impact of FBXW7/hCDC4 promoter methylation in breast cancer.

Methods

FBXW7/hCDC4-β expression and promoter methylation was assessed in 161 tumors from two independent breast cancer cohorts. Associations between methylation status and clinicopathologic characteristics were assessed by Fisher's exact test. Survival was analyzed using the Kaplan-Meier method in addition to modeling the risk by use of a multivariate proportional hazard (Cox) model adjusting for possible confounders of survival.

Results

Methylation of the promoter and loss of mRNA expression was found both in cell lines and primary tumors (43% and 51%, respectively). Using Cox modeling, a trend was found towards decreased hazard ratio (HR) for death in women with methylation of FBXW7/hCDC4-β in both cohorts (HR 0.53 (95% CI 0.23 to 1.23) and HR 0.50 (95% CI 0.23 to 1.08), respectively), despite an association between methylation and high-grade tumors (P = 0.017). Interestingly, in subgroups of patients whose tumors are p53 mutated or lymph-node positive, promoter methylation identified patients with significantly improved survival (P = 0.048 and P = 0.017, respectively).

Conclusions

We demonstrate an alternative mechanism for inactivation of the TSG FBXW7/hCDC4, namely promoter specific methylation. Importantly, in breast cancer, methylation of FBXW7/hCDC4-β is related to favorable prognosis despite its association with poorly differentiated tumors. Future work may define whether FBXW7/hCDC4 methylation is a biomarker of the response to chemotherapy and a target for epigenetic modulation therapy.
Intravenous magnesium sulphate for aneurysmal subarachnoid hemorrhage: an updated systemic review and meta-analysis
Authors: Wong George KC , Boet Ronald , Poon Wai S , Chan Matthew TV , Gin Tony , Ng Stephanie CP , Zee Benny CY
Published: February 2011

Introduction

Previous meta-analyses of magnesium sulphate infusion in the treatment of aneurysmal subarachnoid hemorrhage (SAH) have become outdated due to recently published clinical trials. Our aim was thus to perform an up-to-date systemic review and meta-analysis of published data on the use of magnesium sulphate infusion in aneurysmal SAH patients.

Methods

A systemic review and meta-analysis of the literature was carried out on published randomized controlled clinical trials that investigated the efficacy of magnesium sulphate infusion in aneurysmal SAH patients. The results were analyzed with regard to delayed cerebral ischemia (DCI), delayed cerebral infarction, and favorable neurological outcomes at three and six months. The risks of bias were assessed using the Jadad criteria, with a Jadad score >3 indicating a lower such risk. Meta-analyses are presented in terms of relative risk (RR) with 95% confidence intervals (CIs).

Results

Six eligible studies with 875 patients were reviewed. The pooled RR for DCI was 0.87 (95% CI, 0.36 to 2.09; P = 0.75). That for delayed cerebral infarction was 0.58 (95% CI, 0.35 to 0.97; P = 0.04), although this result did not persist if only randomized clinical trials with a lower risk of bias were included (RR 0.61, 95% CI, 0.31 to 1.22; P = 0.17). The pooled RR for a favorable outcome at three months was 1.14 (95% CI, 0.99 to 1.31; P = 0.07), and that for a favorable outcome at six months was 1.08 (95% CI, 0.94 to 1.24; P = 0.29).

Conclusions

The present findings do not lend support to a beneficial effect of magnesium sulphate infusion on delayed cerebral infarction. The reduction in DCI and improvement in the clinical outcomes of aneurysmal SAH patients following magnesium sulphate infusion observed in previous pilot studies are not confirmed, although a beneficial effect cannot be ruled out because of sample size limitation.
MM-ChIP enables integrative analysis of cross-platform and between-laboratory ChIP-chip or ChIP-seq data
Authors: Chen Yiwen , Meyer Clifford A , Liu Tao , Li Wei , Liu Jun S , Liu Xiaole Shirley
Published: February 2011

The ChIP-chip and ChIP-seq techniques enable genome-wide mapping of in vivo protein-DNA interactions and chromatin states. The cross-platform and between-laboratory variation poses a challenge to the comparison and integration of results from different ChIP experiments. We describe a novel method, MM-ChIP, which integrates information from cross-platform and between-laboratory ChIP-chip or ChIP-seq datasets. It improves both the sensitivity and the specificity of detecting ChIP-enriched regions, and is a useful meta-analysis tool for driving discoveries from multiple data sources.
The role of codon selection in regulation of translation efficiency deduced from synthetic libraries
Authors: Navon Sivan , Pilpel Yitzhak
Published: February 2011

Background

Translation efficiency is affected by a diversity of parameters, including secondary structure of the transcript and its codon usage. Here we examine the effects of codon usage on translation efficiency by re-analysis of previously constructed synthetic expression libraries in Escherichia coli.

Results

We define the region in a gene that takes the longest time to translate as the bottleneck. We found that localization of the bottleneck at the beginning of a transcript promoted a high level of expression, especially if the computed dwell time of the ribosome within this region was sufficiently long. The location and translation time of the bottleneck were not correlated with the cost of expression, approximated by the fitness of the host cell, yet utilization of specific codons was. Particularly, enhanced usage of the codons UCA and CAU was correlated with increased cost of production, potentially due to sequestration of their corresponding rare tRNAs.

Conclusions

The distribution of codons along the genes appears to affect translation efficiency, consistent with analysis of natural genes. This study demonstrates how synthetic biology complements bioinformatics by providing a set-up for well controlled experiments in biology.
Physical and Psychosocial Recovery in the Year After Primary Treatment of Breast Cancer
Authors: Ganz Patricia A. , Kwan Lorna , Stanton Annette L. , Bower Julienne E. , Belin Thomas R.
Published: February 2011

Purpose

The 2000 National Institutes of Health Consensus Conference on Adjuvant Therapy of Breast Cancer recommended chemotherapy for all women with invasive cancer greater than 1 centimeter. Studies of long-term breast cancer survivors have found poorer quality of life (QOL) in women who received adjuvant chemotherapy. The aim of this article is to characterize physical and psychosocial recovery as a function of chemotherapy receipt in the year after medical treatment completion.

Patients and Methods

Prospective longitudinal survey data (RAND SF-36 and Breast Cancer Prevention Trial [BCPT] Symptom Scales) collected from 558 women with breast cancer enrolled on the Moving Beyond Cancer (MBC) psychoeducational intervention trial were compared according to receipt of chemotherapy. MBC study enrollment occurred within 4 weeks after the end of primary treatment (eg, surgery, chemotherapy, radiation). Self-report questionnaire data collected at enrollment and at 2, 6, and 12 months thereafter were examined, controlling for intervention and with propensity score adjustment for imbalance of covariates. Outcome analyses were carried out by fitting linear mixed models by using SAS PROC MIXED.

Results

Longitudinal SF-36 scale scores did not differ by chemotherapy treatment exposure, and both groups improved significantly (P < .01) in the year after primary treatment ended. However, adjuvant chemotherapy treatment was associated with significantly more severe physical symptoms, including musculoskeletal pain (P = .01), vaginal problems (P < .01), weight problems (P = .01), and nausea (P = .03).

Conclusion

Physical and psychosocial functioning improved significantly after breast cancer treatment, independent of receipt of adjuvant chemotherapy. Women who received chemotherapy experienced more severe and persistent physical symptoms that should be more effectively managed as part of survivorship care.
Phase I/II Study of Pemetrexed With or Without ABT-751 in Advanced or Metastatic Non–Small-Cell Lung Cancer
Authors: Rudin Charles M. , Mauer Ann , Smakal Martin , Juergens Rosalyn , Spelda Stanislav , Wertheim Michael , Coates Andrew , McKeegan Evelyn , Ansell Peter , Zhou Xiangdong , Qian Jane , Pradhan Rajendra , Dowell Barry , Krivoshik Andrew , Gordon Gary
Published: February 2011

Purpose

ABT-751 is an antimitotic and vascular disrupting agent with potent preclinical anticancer activity. We conducted a phase I and randomized double-blind phase II study of pemetrexed with ABT-751 or placebo in patients with recurrent advanced or metastatic non–small-cell lung cancer (NSCLC).

Methods

One hundred seventy-one patients received intravenous pemetrexed 500 mg/m2 day 1 and oral ABT-751 or placebo days 1 to 14 of 21-day cycles. The primary end point was progression-free survival (PFS). Secondary end point included overall survival (OS); pharmacokinetic and pharmacodynamic parameters were also analyzed.

Results

The recommended phase II dose of ABT-751 with pemetrexed is 200 mg. Fatigue, constipation, anemia, nausea, and diarrhea were the most common toxicities in both study arms. No pharmacokinetic interactions were observed. Median PFS in the ABT-751 arm was 2.3 months versus 1.9 for placebo (P = .819, log-rank) for the intention-to-treat population. However, differences in PFS (P = .112, log-rank) and OS (P = .034, log-rank; median 3.3 v 8.1 months) favoring ABT-751 were seen in the squamous NSCLC subgroup. Baseline circulating tumor cell concentrations were predictive of improved OS (P = .013). Changes from baseline of greater than 20% in plasma levels of placenta growth factor (P = .056), squamous cell carcinoma antigen (P = .03), and cytokeratin 19 fragment antigen 21-1 (P = .01) were markers best associated with improved OS.

Conclusion

Addition of ABT-751 to pemetrexed is well-tolerated, but does not improve outcome in unselected patients with recurrent NSCLC. ABT-751 may have therapeutic potential in squamous NSCLC. Exploratory cellular and molecular analyses in this study identified biomarkers that may correlate with survival.
Features Predicting Sentinel Lymph Node Positivity in Merkel Cell Carcinoma
Authors: Schwartz Jennifer L. , Griffith Kent A. , Lowe Lori , Wong Sandra L. , McLean Scott A. , Fullen Douglas R. , Lao Christopher D. , Hayman James A. , Bradford Carol R. , Rees Riley S. , Johnson Timothy M. , Bichakjian Christopher K.
Published: February 2011

Purpose

Merkel cell carcinoma (MCC) is a relatively rare, potentially aggressive cutaneous malignancy. We examined the clinical and histologic features of primary MCC that may correlate with the probability of a positive sentinel lymph node (SLN).

Methods

Ninety-five patients with MCC who underwent SLN biopsy at the University of Michigan were identified. SLN biopsy was performed on 97 primary tumors, and an SLN was identified in 93 instances. These were reviewed for clinical and histologic features and associated SLN positivity. Univariate associations between these characteristics and a positive SLN were tested for by using either the χ2 or the Fisher's exact test. A backward elimination algorithm was used to help create a best multiple variable model to explain a positive SLN.

Results

SLN positivity was significantly associated with the clinical size of the lesion, greatest horizontal histologic dimension, tumor thickness, mitotic rate, and histologic growth pattern. Two competing multivariate models were generated to predict a positive SLN. The histologic growth pattern was present in both models and combined with either tumor thickness or mitotic rate.

Conclusion

Increasing clinical size, increasing tumor thickness, increasing mitotic rate, and infiltrative tumor growth pattern were significantly associated with a greater likelihood of a positive SLN. By using the growth pattern and tumor thickness model, no subgroup of patients was predicted to have a lower than 15% to 20% likelihood of a positive SLN. This suggests that all patients presenting with MCC without clinical evidence of regional lymph node disease should be considered for SLN biopsy.
Cooperative activity of noggin and gremlin 1 in axial skeleton development
Authors: Stafford David A. , Brunet Lisa J. , Khokha Mustafa K. , Economides Aris N. , Harland Richard M.
Published: February 2011

Inductive signals from adjacent tissues initiate differentiation within the somite. In this study, we used mouse embryos mutant for the BMP antagonists noggin (Nog) and gremlin 1 (Grem1) to characterize the effects of BMP signaling on the specification of the sclerotome. We confirmed reduction of Pax1 and Pax9 expression in Nog mutants, but found that Nog;Grem1 double mutants completely fail to initiate sclerotome development. Furthermore, Nog mutants that also lack one allele of Grem1 exhibit a dramatic reduction in axial skeleton relative to animals mutant for Nog alone. By contrast, Pax3, Myf5 and Lbx1 expression indicates that dermomyotome induction occurs in Nog;Grem1 double mutants. Neither conditional Bmpr1a mutation nor treatment with the BMP type I receptor inhibitor dorsomorphin expands sclerotome marker expression, suggesting that BMP antagonists do not have an instructive function in sclerotome specification. Instead, we hypothesize that Nog- and Grem1-mediated inhibition of BMP is permissive for hedgehog (Hh) signal-mediated sclerotome specification. In support of this model, we found that culturing Nog;Grem1 double-mutant embryos with dorsomorphin restores sclerotome, whereas Pax1 expression in smoothened (Smo) mutants is not rescued, suggesting that inhibition of BMP is insufficient to induce sclerotome in the absence of Hh signaling. Confirming the dominant inhibitory effect of BMP signaling, Pax1 expression cannot be rescued in Nog;Grem1 double mutants by forced activation of Smo. We conclude that Nog and Grem1 cooperate to maintain a BMP signaling-free zone that is a crucial prerequisite for Hh-mediated sclerotome induction.
β-Catenin specifies the endomesoderm and defines the posterior organizer of the hemichordate Saccoglossus kowalevskii
Authors: Darras Sébastien , Gerhart John , Terasaki Mark , Kirschner Marc , Lowe Christopher J.
Published: February 2011

The canonical Wnt/β-catenin pathway is a key regulator of body plan organization and axis formation in metazoans, being involved in germ layer specification, posterior growth and patterning of the anteroposterior axis. Results from animals spanning a wide phylogenetic range suggest that a unifying function of β-catenin in metazoans is to define the posterior/vegetal part of the embryo. Although the specification of vegetal territories (endoderm) by β-catenin has been demonstrated in distantly related animals (cnidarians, a protostome, echinoderms and ascidians), the definition of the posterior part of the embryo is well supported only for vertebrates and planarians. To gain insights into β-catenin functions during deuterostome evolution, we have studied the early development of the direct developing hemichordate Saccoglossus kowalevskii. We show that the zygote is polarized after fertilization along the animal-vegetal axis by cytoplasmic rearrangements resembling the ascidian vegetal contraction. This early asymmetry is translated into nuclear accumulation of β-catenin at the vegetal pole, which is necessary and sufficient to specify endomesoderm. We show that endomesoderm specification is crucial for anteroposterior axis establishment in the ectoderm. The endomesoderm secretes as yet unidentified signals that posteriorize the ectoderm, which would otherwise adopt an anterior fate. Our results point to a conserved function at the base of deuterostomes for β-catenin in germ layer specification and to a causal link in the definition of the posterior part of the embryonic ectoderm by way of activating posteriorizing endomesodermal factors. Consequently, the definition of the vegetal and the posterior regions of the embryo by β-catenin should be distinguished and carefully re-examined.
Quantification of aerodynamically induced noise and vibration-induced noise in a suction unit
Authors: Prezelj J , Čudina M
Published: February 2011

Noise, generated by a centrifugal blower, can be divided according to its origin, into aerodynamically induced noise and vibration-induced noise. The contribution of the individual noise source to the total emitted noise is hard to determine, but it is crucial for the design of noise reduction measures. In order to reduce the noise of the centrifugal blower in a broad range of operating conditions, an identification of noise sources needs to be performed. An analysis of the most important noise origin in a centrifugal blower presented in this article was performed by measurements of the transfer function between noise and vibration, under different types of excitation. From the analyses one can conclude that the dominant noise source of a centrifugal blower can be attributed to the aerodynamically generated noise which exceeds the vibration-induced noise for more than 10 dB in a broad frequency range.
A New Concept for Disruption Management in Airline Operations Control
Authors: Castro A J M , Oliveira E
Published: February 2011

The Airline Operations Control Centre (AOCC) of an airline company is the organization responsible for monitoring and solving operational problems. It includes teams of human experts specialized in solving problems related with aircrafts, crewmembers, and passengers, in a process called disruption management or operations recovery. In this article, the authors propose a new concept for disruption management in this domain. The organization of the AOCC is represented by a multi-agent system (MAS), where roles that correspond to the most frequent tasks that could benefit from a cooperative approach, are performed by intelligent agents. The human experts, represented by agents that are able to interact with them, are part of this AOCC-MAS supervising the system and taking the final decision from the solutions proposed by the AOCC-MAS. The authors show the architecture of this AOCC-MAS, including the main costs involved and details about how the system takes decisions. They tested the concept, using several real airline crew-related problems and using four methods: human experts (traditional way), the AOCC-MAS with and without using quality-costs, and the integrated approach presented in this article. The results are presented and discussed.
100 Years of the American Economic Review: The Top 20 Articles
Authors: Arrow Kenneth J , Bernheim B. Douglas , Feldstein Martin S , McFadden Daniel L , Poterba James M , Solow Robert M
Published: February 2011

This paper presents a list of the top 20 articles published in the American Economic Review during its first 100 years. This list was assembled in honor of the AER's one-hundredth anniversary by a group of distinguished economists at the request of AER's editor. A brief description accompanies the citations of each article.
Is Tiger Woods Loss Averse? Persistent Bias in the Face of Experience, Competition, and High Stakes
Authors: Pope Devin G , Schweitzer Maurice E
Published: February 2011

Although experimental studies have documented systematic decision errors, many leading scholars believe that experience, competition, and large stakes will reliably extinguish biases. We test for the presence of a fundamental bias, loss aversion, in a high-stakes context: professional golfers' performance on the PGA Tour. Golf provides a natural setting to test for loss aversion because golfers are rewarded for the total number of strokes they take during a tournament, yet each individual hole has a salient reference point, par. We analyze over 2.5 million putts using precise laser measurements and find evidence that even the best golfers—including Tiger Woods—show evidence of loss aversion. (JEL D03, D81, L83).
The Effect of Female Education on Fertility and Infant Health: Evidence from School Entry Policies Using Exact Date of Birth
Authors: McCrary Justin , Royer Heather
Published: February 2011

This paper uses age-at-school-entry policies to identify the effect of female education on fertility and infant health. We focus on sharp contrasts in schooling, fertility, and infant health between women born just before and after the school entry date. School entry policies affect female education and the quality of a woman's mate and have generally small, but possibly heterogeneous, effects on fertility and infant health. We argue that school entry policies manipulate primarily the education of young women at risk of dropping out of school. (JEL I12, I21, J13, J16)
The Economic History of the American Economic Review: A Century's Explosion of Economics Research
Authors: Margo Robert A
Published: February 2011

Written in celebration of the 100th anniversary of the American Economic Review, this paper recounts the history of the journal. The recounting has an analytic core that sees the American Economic Association as an organization supplying goods and services to its members, one of which is the Review. Early in its history the Review was a multipurpose publication with highly disparate content. Over time the economics profession expanded and more economics research was produced, primarily in the form of journal articles. Editors accommodated this shift by allocating more resources to the refereeing and editing process and more space to research papers. (JEL A14, B19, B29)
Risk factors for delayed HIV diagnosis at the hospital of tropical diseases in Ho Chi Minh City, Vietnam
Authors: Nhac-Vu H-T , Giard M , Phong N-D , Vanhems P
Published: February 2011

The objective was to identify factors associated with delayed diagnosis of HIV infection in Vietnam, defined as having a CD4 cell count of <200/mm3 at the time of the first positive test. Data were collected retrospectively from the medical records of HIV-infected outpatients who received their initial care at the Hospital for Tropical Diseases in Ho Chi Minh City between July 2004 and August 2005. Among the 204 included patients, 58.3% had a delayed diagnosis. Independent factors associated with a delayed diagnosis were male gender (adjusted odds ratio [AOR] = 2.10; 95% confidence interval [CI] = 1.03–4.41) and having an opportunistic infection at the time of the first positive HIV test (AOR = 3.07; 95% CI = 1.71–5.53). Counselling for early HIV screening is important in populations at risk of infection. Facilitating access to care should be reinforced for symptomatic patients.
Cervical screening uptake in immunocompromised women in Waikato, New Zealand
Authors: Lim E J , Morgan J , Fielding R
Published: February 2011

A one-year retrospective case study was undertaken of cervical cytology in two cohorts of immunocompromised women: those with HIV infection or renal transplants in the Waikato region of New Zealand. Uptake of cervical screening in the two groups was compared with national guidelines. The results showed that HIV patients' uptake was close to the national recommendation for annual cytology (84% had a smear in 18 months); they were more likely to have cytology performed in an HIV-related care setting. Renal transplant patients had lower uptake (56% in 18 months), a finding similar to internationally reported data. Local discussions of these results identified potential influencing factors, which included inadequate dissemination of updated guidelines and inadequate documentation of immunocompromised health status on the national cervical screening programme database. This audit supports including cervical cytology as part of an annual review in all immunocompromised patients.
Reactive Sorption on Functional Furan Resins
Authors: Rodriguez Ruben J.S. , Hernández Carlos , da Silva Victor Teixeira
Published: February 2011

The immobilization of different substrates by specific interactions with insoluble functional supports has developed into quite an active research topic. In the present work, the interaction of two furanic resins obtained by acid catalysis from furfuraldehyde and furfuraldehyde–dimethylketone was studied at 0 °C and 30 °C. Both resins adsorbed ca. 10−3 mol of ammonia at these temperatures and the adsorption process was characterized by a long period before equilibrium was attained, with the corresponding data being fitted by the Freundlich adsorption model. The structures of the resins were characterized using Fourier-transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. Through the use of temperature-programmed desorption coupled with mass spectrometry (TPD–MS), it was possible to infer that ammonia adsorption modified the original chemical structure of the resins to yield imine structures as a result of the reaction of ammonia with the existing more reactive carbonyl groups.
Removal of Copper(II) Ions from Aqueous Solution Using Alkali-Treated Kenaf Core Fibres
Authors: Sajab Mohd Shaiful , Chia Chin-Hua , Zakaria Sarani , Jani S. Mohd , Khiew P.S. , Chiu W.S.
Published: February 2011

In this study, the sorption of Cu(II) ions from aqueous solution onto NaOH-treated kenaf core fibres was investigated. The kenaf core fibres were milled into different sizes and treated with NaOH before being used to investigate their efficiency in removing Cu(II) ions from aqueous solutions. Sorption studies were performed at a pH value of 5. Sorption of the Cu(II) ions increased and the sorption yield decreased with increasing initial Cu(II) ion concentration. The sorption data were correlated with the Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherms. The values of the correlation coefficients obtained indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich and D–R isotherms. Kenaf core fibres with fibre sizes in the range 150–300 μm possessed the highest sorption capacity. The calculated parameters of the isotherms suggest that the uptake of Cu(II) ions occurred at the homogeneous active sites on the surfaces of the kenaf core fibres.
Digging it out of the Dirt: Ben Hogan, Deliberate Practice and the Secret
Authors: Jenkins Simon
Published: February 2011

The purpose of this article is to use Anders Ericsson's theory of deliberate practice to examine the way in which the legendary golfer Ben Hogan worked on his game. Of particular importance in Hogan working on his game was overcoming a destructive hook shot, which he attributed to what became known as “Hogan's Secret”. It is argued that the Secret can be understood in terms of Hogan developing a more integrated understanding of his golf swing.
Indirect Aggression and Victimization are Positively Associated in Emerging Adulthood: The Psychological Functioning of Indirect Aggressors and Victims
Authors: Leenaars Lindsey , Lester David
Published: February 2011

A study of 106 undergraduate students found that scores on measures of indirect aggression, both as aggressors and as victims, given to separate respondents, were associated with scores on measures of anger discomfort, silencing the self, and subscales of the Buss and Durkee Hostility Inventory (1957). A second study, of 113 undergraduate students, found that scores on the measures of indirect aggression (as aggressor and as victim, with both scales given to each respondent) were positively associated, indicating that aggressors are often victims. Scores on both measures of indirect aggression were positively associated with scores on measures of silencing the self.
Perspectives on Identity, Disclosure, and the Campus Environment Among African American Gay and Bisexual Men at One Historically Black College
Authors: Patton Lori D.
Published: February 2011

This qualitative study examined how 6 African American men at one historically Black college made meaning of their gay or bisexual identity, made decisions about to whom they disclosed this identity, and how their sexual identity experiences were mediated given the context of the campus environment. The findings suggest although this particular HBCU (historically Black college and university) provided the participants an overall supportive and uplifting environment, they experienced challenges with publicly expressing their sexual identities. Implications and recommendations for future research and practice are offered.
Conceptualizing the Engaging Bystander Approach to Sexual Violence Prevention on College Campuses
Authors: McMahon Sarah , Postmus Judy L. , Koenick Ruth Anne
Published: February 2011

Bystander intervention offers promise as a sexual violence prevention tool for student affairs administrators on college campuses, but the conceptualization and definition of the approach is in its infancy and needs further development. In an effort to emphasize the potential role of bystanders in the primary prevention of sexual violence, we put forth the "engaging bystander approach" (EBA). We discuss how EBA can be used to address primary prevention and present updated versions of Banyard, Plante, and Moynihan's (2005) Bystander Attitude Scale and Bystander Behavior Scale. We then present the results from a quantitative study with 951 undergraduate students that used the updated scales to assess the willingness of incoming college students to engage in primary prevention bystander behaviors. We conclude with implications for future studies and for sexual violence prevention programs on college campuses.
Student-Generated Protective Behaviors to Avert Severe Harm Due to High-Risk Alcohol Consumption
Authors: Smith Sandi W. , LaPlante Carolyn , Wibert Wilma Novales , Mayer Alex , Atkin Charles K. , Klein Katherine , Glazer Edward , Martell Dennis
Published: February 2011

High-risk alcohol consumption is a significant problem on college campuses that many students see as a rite of passage in their development into adulthood. Developing effective prevention campaigns designed to lessen or avert the risks associated with alcohol consumption entails understanding how students perceive harmful consequences as well as the ways they protect themselves while drinking. This study used survey research to determine what undergraduate students perceived to be the most severe alcohol-related harms and the protective behaviors that they thought would be effective at averting those harms. Results showed that students saw forced sex as the most severe alcohol-related harm, and the most commonly described protective behavior was personal responsibility. Implications of these findings for campus-focused health communication strategists and directions for future research are discussed.
Exposure to Effective Instruction and College Student Persistence: A Multi-Institutional Replication and Extension
Authors: Pascarella Ernest T. , Salisbury Mark H. , Blaich Charles
Published: February 2011

This study analyzed a multi-institutional and longitudinal data set to determine the impact of exposure to effective instruction on first-year persistence—defined as reenrolling for the second year of college at the same institution. Net of important confounding influences, exposure to effective instruction significantly increased the likelihood that the student would reenroll for the second year of college. The effect was mediated primarily through student satisfaction with the quality of the overall educational experience at the institution. These findings have implications for the role of the classroom experience in student persistence in higher education.
Assessing Students' Spiritual and Religious Qualities
Authors: Astin Alexander W. , Astin Helen S. , Lindholm Jennifer A.
Published: February 2011

This paper describes a comprehensive set of 12 new measures for studying undergraduate students' spiritual and religious development. The three measures of spirituality, four measures of "spiritually related" qualities, and five measures of religiousness demonstrate satisfactory reliability, robustness, and both concurrent and predictive validity. It is hoped that these new measures can not only provide researchers with some new tools for tracking important aspects of student development that have so far received very little attention in the higher education literature, but also provide new insights for practitioners who are working to implement a more holistic approach to enhancing the undergraduate experience.
To What Degree Are Croatian and Serbian the Same Language?: Evidence from a Translation Study
Authors: Bailyn John Frederick
Published: February 2011

This article reports on the results of an experimental translation study conducted in 2008 in which 16 adult native speakers of the Croatian variant of Bosnian-Croatian-Serbian (BCS) were asked to translate nine texts from the Serbian BCS variant into their native Croatian variant in order to test the extent to which Croatian and Serbian do or do not employ distinct linguistic devices. The results show, on the basis of a statistical comparison of the purely grammatical building blocks in the original texts and their translations, that the Croatian and Serbian variants of BCS have essentially identical linguistic systems across all levels of language structure. In particular, we find that the phonological and syntactic systems are essentially identical and that over 98% of derivational and inflectional morphology tokens are identical. Lexically, the open classes show a difference of less than 10% of tokens, whereas the closed grammatical classes show identity in over 95% of cases.
On the Distribution of - kolwiek 'ever' in Polish Free Relatives
Authors: Citko Barbara
Published: February 2011

This paper analyzes the distribution of the particle - kolwiek 'ever' in Polish free relatives. The empirical observation it builds on concerns the obligatory presence of - kolwiek in complex free relatives. I argue against accounts that reduce this requirement to purely semantic considerations and propose a syntactic account instead. This account rests on independently motivated claims about the structure of Polish noun phrases and the positive setting of the DP Parameter for Polish. The crucial innovation lies in the structure proposed for wh -phrases in free relatives; I argue that such wh -phrases have a more complex internal structure than wh -phrases in questions, in that they require the topmost head inside the nominal projection, the Q head, to be filled by an overt element in order to support the maximality operator associated with the interpretation of free relatives.
Palatalized Labials in Polish Dialects: An Evolutionary Perspective
Authors: Czaplicki Bartłomiej
Published: February 2011

Two types of explanations for typological asymmetries are in current use: synchronic, which rely on phonological filters that make learners more receptive to some patterns than others (e.g., markedness), and diachronic, which appeal to phonetically systematic errors that arise in the transmission of the speech signal. This paper provides a diachronic account of palatalized labials in standard and dialectal Polish. It is shown that the weak perceptibility of the palatal element in a specific phonetic context is a good predictor of depalatalization and that dissimilation arises whenever a phonetic signal can be interpreted in a non-unique manner. The Polish data exemplify three sources of natural sound change: (i) neutralization of perceptually weak contrasts, (ii) phonological reanalysis of ambiguous signals, and (iii) change in the frequency of phonetic variants. Sound change is shown to be non-deterministic and non-optimizing. There is no role for markedness in this account.