Seismic behavior of non seismically designed eccentric reinforced concrete beam column joints

Non seismically designed eccentric reinforced concrete beam column joints were extensively used in existing reinforced concrete frame buildings, which were found to be vulnerable to seismic action in many incidences. To provide a fundamental understanding of the seismic performance and failure mechanism of the joints, three 2/3 scale exterior beam column joints with non seismically designed details were cast and tested under reversed cyclic loads simulating earthquake excitation. In this investigation, particular emphasis was given on the effects of the eccentricity between the centerlines of the beam and the column. It is shown that the eccentricity had significant effects on the damage characteristics, shear strength, and displacement ductility of the specimens. In addition, shear deformation and the strain of joint hoops were found to concentrate on the eccentric face of the joint. The results demonstrated that the specimen with an eccentricity of 1/4 column width failed in a brittle manner with premature joint shear failure, while the other specimens with less or no eccentricity failed in a ductile manner with joint shear failure after beam flexural yielding. Test results are compared with those predicted by three seismic design codes and two non seismic design codes. In general, the codes do not accurately predict the shear strength of the eccentric joints with non seismic details

The effects of group decision support systems and task structures on group decision processes and outcomes : an experimental investigation

This research examines whether structures of decision tasks moderate the effects of group decision support systems (GDSS) on patterns of group communication and decision outcomes of decision making groups. This research also examines the relationship between patterns of group communication and decision outcomes. Although prior research has shown that the effects of GDSS on group decision making are not uniformly positive, conditions under which the use of GDSS is appropriate and beneficial are not well understood. The characteristics of the group task are emerging as important variables that are believed to moderate the effects of GDSS on group decision making. Failure to explicitly study the role of group communication in group decision making is another reason why prior research on GDSS has yielded much conflicting evidence. This research seeks to show that the effects of GDSS on decision making processes and outcomes are task structure dependent and the effects of GDSS cannot be evaluated on the basis of outcomes alone; decision processes must also be evaluated in order to understand how decisions are made and why GDSS can improve group outcomes in some situations but provide negative effects in others. A controlled laboratory experiment was conducted with a 2x3 factorial between-subjects design, manipulating two independent variables: levels of support (GDSS support and no support) and task structures (additive, disjunctive and conjunctive). Practising managers were chosen as subjects. Using a personnel recruitment exercise as the experimental task, the structure of the task was manipulated by varying the group members’ role and information distribution. Subjects were either provided with GDSS or with no support. The experiment was administered to the subjects who were participating in a management training course. The discussion records of the decision making process were coded using a coding scheme. Other dependent variables were decision quality, decision time and perceived satisfaction with process and outcome. The research results support the hypothesis that structures of a decision task moderate the effects of GDSS on both the patterns of group communication and decision outcomes of a decision making group. GDSS significantly improve decision quality in disjunctive and conjunctive tasks. GDSS also significantly alter patterns of group communication in disjunctive and conjunctive tasks. However, no significant differences in decision quality and patterns of group communication exist between groups using GDSS and face-to-face groups in additive tasks. The results also show strong relationships between patterns of group communication and decision outcomes. The research provides strong support for the theory that an understanding of how GDSS shape the patterns of group communication is likely to provide an explanation as to why GDSS can improve group outcomes in some situations but fail to perform in others

Structural change and the narrowing gender gap in wages : theory and evidence from Hong Kong

This paper offers a theoretical and empirical analysis on the sources of the narrowing gender gap in wages. Based on some existing literature, the model posits that the narrowing gender gap may be related to women\u27s changing comparative advantage and the gender gap is smaller in occupations in which physical labor is less intensively used. The model implies that when an economy transforms from a manufacturing-oriented economy to service-oriented economy, a woman\u27s productivity relative to a man\u27s will generally increase so that the gender gap narrows. The implications of the theoretica1 analysis are then tested based on one percent random sub-samples of two population censuses. The empirical results support the predictions of the model

Outcomes of patients with Kaposi's sarcoma who start antiretroviral therapy under routine programme conditions in Malawi.

AIDS-associated Kaposi's sarcoma (KS) is the most common AIDS-related malignancy in sub-Saharan Africa, with a generally unfavourable prognosis. We report on six-month and 12-month cohort treatment outcomes of human immunodeficiency virus (HIV)-positive KS patients and HIV-positive non-KS patients treated with antiretroviral therapy (ART) in public sector facilities in Malawi. Data were collected from standardized antiretroviral (ARV) patient master cards and ARV patient registers. Between July and September 2005, 7905 patients started ART-488 (6%) with a diagnosis of KS and 7417 with a non-KS diagnosis. Between January and March 2005, 4580 patients started ART-326 (7%) with a diagnosis of KS and 4254 with a non-KS diagnosis. At six-months and 12-months, significantly fewer KS patients were alive and significantly more had died or defaulted compared to non-KS patients. HIV-positive KS patients on ART in Malawi have worse outcomes than other patients on ART. Methods designed to improve these outcomes must be found

The wheat Lr34 multi-pathogen resistance gene confers resistance to anthracnose and rust in sorghum

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A National Survey of Teachers on Antiretroviral Therapy in Malawi: Access, Retention in Therapy and Survival

BACKGROUND: HIV/AIDS is having a devastating effect on the education sector in sub-Saharan Africa. A national survey was conducted in all public sector and private sector facilities in Malawi providing antiretroviral therapy (ART) to determine the uptake of ART by teachers and their outcomes while on treatment. METHODOLOGY/PRINCIPAL FINDINGS: A retrospective cohort study was carried out based on patient follow-up records from ART Registers and treatment master cards in all 138 ART clinics in Malawi; observations were censored on September 30(th) 2006. By this date, Malawi's 102 public sector and 36 private sector ART clinics had registered a total of 72,328 patients for treatment. Of these, 2,643 (3.7%) were teachers. Adjusting for double-registration caused by clinic transfers, it is estimated that 2,380 individual teachers had ever accessed ART. There were 15% of teachers starting ART in WHO clinical stage 1 or 2 with a CD4-lymphocyte count of <or=250/mm(3) and 85% starting in stage 3 or 4. By 30(th) September 2006, 1,850 teachers were alive on ART (3.5% of all teachers in Malawi). The probability of being alive on ART at 6-months, 12-months, 18-months and 24-months after treatment initiation was 84%, 79%, 75% and 73% respectively. Retention in treatment was better for women (adjusted HR = 1.8) and in those starting ART in WHO Clinical Stage 1 and 2 (adjusted HR = 1.8). CONCLUSION/SIGNIFICANCE: Rapid scale up of ART has allowed 2,380 HIV-positive teachers to access life-prolonging treatment. There is evidence that this intervention can help to mitigate some of the shortages of teaching personnel in resource-poor countries affected by a generalised HIV epidemic

Antiretroviral Therapy in the Malawi Defence Force: Access, Treatment Outcomes and Impact on Mortality

BACKGROUND: HIV/AIDS affects all sectors of the population and the defence forces are not exempt. A national survey was conducted in all public and private sectors in Malawi that provide antiretroviral therapy (ART) to determine the uptake of ART by army personnel, their outcomes while on treatment, and the impact of ART on mortality in the Malawi Defence Force. METHODOLOGY/PRINCIPAL FINDINGS: A retrospective cohort analysis was carried out, collecting data on access and retention on treatment from all 103 public and 38 private sector ART clinics in Malawi, using standardised patient master cards and clinic registers. Observations were censored on December 31(st) 2006. Independent data on mortality trends in army personnel from all causes between 2002 and 2006 were available from army records. By December 31(st) 2006, there were 85,168 patients ever started on ART in both public and private sectors, of whom 547 (0.7%) were army personnel. Of these, 22% started ART in WHO clinical stage 1 or 2 with a CD4-lymphocyte count of <or=250/mm(3) and 78% started in stage 3 or 4. Treatment outcomes of army personnel by December 31(st) 2006 were:-365 (67%) alive and on ART at their registration facility, 98 (18%) transferred out to another facility, 71 (13%) dead, 9 (2%) lost to follow-up, and 4 (<1%) stopped treatment. The probability of being alive on ART at 6-, 12- and 18-months was 89.8%, 83.4% and 78.8% respectively. All-cause mortality in army personnel declined dramatically over the five year period from 2002-2006. CONCLUSION/SIGNIFICANCE: There has been a good access of army personnel to ART during the last five years with excellent outcomes, and this should serve as an example for other defence forces and large companies in the region

The ENIGMA Stroke Recovery Working Group: Big data neuroimaging to study brain–behavior relationships after stroke

The goal of the Enhancing Neuroimaging Genetics through Meta‐Analysis (ENIGMA) Stroke Recovery working group is to understand brain and behavior relationships using well‐powered meta‐ and mega‐analytic approaches. ENIGMA Stroke Recovery has data from over 2,100 stroke patients collected across 39 research studies and 10 countries around the world, comprising the largest multisite retrospective stroke data collaboration to date. This article outlines the efforts taken by the ENIGMA Stroke Recovery working group to develop neuroinformatics protocols and methods to manage multisite stroke brain magnetic resonance imaging, behavioral and demographics data. Specifically, the processes for scalable data intake and preprocessing, multisite data harmonization, and large‐scale stroke lesion analysis are described, and challenges unique to this type of big data collaboration in stroke research are discussed. Finally, future directions and limitations, as well as recommendations for improved data harmonization through prospective data collection and data management, are provided