96,041 research outputs found
HIV-infected pregnant adolescents and youth : results from a European cohort study
No full textGlobally the HIV epidemic mainly affects young people, particularly young females who are vulnerable to acquisition of HIV as a result of their biological and social susceptibility. Women represent an increasing proportion of newly diagnosed HIV cases in Western and Eastern Europe, reaching 35% and 40%, respectively, in 2004. In the European Collaborative Study (ECS), HIV-infected pregnant women are enrolled and their infants followed-up prospectively. By the end of 2005, 5956 women had enrolled, of whom 1912 (32%) were aged < 25 years at delivery. Enrolments of youth declined in Western European centres from 59% in 1985 to 18% in 2005. In Ukraine, youth enrolments declined from 52% in 2001 to 43% in 2005. Median ages of the young and older sub-cohorts were 22.3 and 29.9 years, respectively. Injecting drug use (IDU) was more common in the older than younger sub-cohorts [42% (n = 1684) vs. 35% (n = 675), p < 0.001]. However, young IDUs were more likely to be currently using injecting drugs than older IDUs (59% vs. 38%, p < 0.001), to report current sharing of injecting equipment (22% vs. 13%, p = 0.001) and to report an IDU sex partner (59% vs. 48%, p < 0.02). Young HIV-infected pregnant women in Europe are a heterogeneous group, possibly less identifiable as being at risk of HIV infection. They will have diverse needs for services during and after pregnancy, including harm reduction services and psychosocial support, in addition to a universal need for prevention of mother-to-child transmission services
Prognosis of epilepsy in newly referred patients: a multicenter prospective study of the effects of monotherapy on the long-term course of epilepsy.
No full textA cohort of 280 previously untreated epilepsy subjects recruited in 14 Italian centers were treated with antiepileptic drug monotherapy and followed for a median period of 48 months to investigate the rates of seizure remission, in general and with reference to various prognostic factors. The cumulative probability of achieving 1-year remission was 62% by 1 year after onset of treatment, 81% by 2 years, 92% by 3 years, and 98% by 5 years. The corresponding figures for 2- and 3-year remission at 5 years were 92 and 78%, respectively. Sixty-two patients (22.1%) had no remission period with monotherapy. Remission rate were significantly lower among patients with two or more seizure types and were inversely correlated to the number of seizures before treatment. The rate of seizure relapses during the first year of follow-up appear to correlate to the risk of developing refractory epileps
Intelligent support for group work in collaborative learning environments
No full textThe delivery of intelligent support for group work is a complex issue in
collaborative learning environments. This particularly pertains to the construction
of effective groups and assessment of collaboration problems. This is because the
composition of groups can be affected by several variables, and various methods
are desirable for ascertaining the existence of different collaboration problems.
Literature has shown that current collaborative learning environments provide
limited or no support for teachers to cope with these tasks. Considering this and the
increasing use of online collaboration, this research aims to explore solutions for
improving the delivery of support for group work in collaborative learning
environments, and thus to simplify how teachers manage collaborative group work.
In this thesis, three aspects were investigated to achieve this goal. The first
aspect emphasises on proposing a novel approach for group formation based on
students‘ learning styles. The novelty and importance of this approach is the
provision of an automatic grouping method that can tailor to individual students‘
characteristics and fit well into the existing collaborative learning environments.
The evaluation activities comprise the development of an add-on tool and an
undergraduate student experiment, which indicate the feasibility and strength of the
proposed approach — being capable of forming diverse groups that tend to perform
more effectively and efficiently than similar groups for conducting group
discussion tasks.
The second focus of this research relates to the identification of major
group collaboration problems and their causes. A nationwide survey was conducted
that reveals a student perspective on the issue, which current literature fails to
adequately address. Based on the findings from the survey, an XML-based
representation was created that provides a unique perspective on the linkages
between the problems and causes identified.
Finally, the focus was then shifted to the proposal of a novel approach for
diagnosing the major collaboration problems identified. The originality and
significance of this approach lies in the provision of various methods for ascertaining the existence of different collaboration problems identified, based on
student interaction data that result from the group work examined. The evaluation
procedure focused on the development of a supporting tool and several
experiments with a test dataset. The results of the evaluation show that the
feasibility and effectiveness are sustained, to a great extent, for the diagnostic
methods addressed.
Besides these main proposals, this research has explored a multi-agent
architecture to unify all the components derived for intelligently managing online
collaborative learning, which suggests an overarching framework providing
context for other parts of this thesis
MRC/BHF Heart Protection Study of cholesterol lowering with simvastatin in 20 536 high-risk individuals: a randomised placebocontrolled trial
No full textBackground: Throughout the usual LDL cholesterol range in Western populations, lower blood concentrations are associated with lower cardiovascular disease risk. In such populations, therefore, reducing LDL cholesterol may reduce the development of vascular disease, largely irrespective of initial cholesterol concentrations. Methods: 20 536 UK adults (aged 40–80 years) with coronary disease, other occlusive arterial disease, or diabetes were randomly allocated to receive 40 mg simvastatin daily (average compliance: 85%) or matching placebo (average non-study statin use: 17%). Analyses are of the first occurrence of particular events, and compare all simvastatin-allocated versus all placebo-allocated participants. These “intention-to-treat” comparisons assess the effects of about two-thirds (85% minus 17%) taking a statin during the scheduled 5-year treatment period, which yielded an average difference in LDL cholesterol of 1·0 mmol/L (about two-thirds of the effect of actual use of 40 mg simvastatin daily). Primary outcomes were mortality (for overall analyses) and fatal or non-fatal vascular events (for subcategory analyses), with subsidiary assessments of cancer and of other major morbidity. Findings: All-cause mortality was significantly reduced (1328 [12·9%] deaths among 10 269 allocated simvastatin versus 1507 [14·7%] among 10 267 allocated placebo; p=0·0003), due to a highly significant 18% (SE 5) proportional reduction in the coronary death rate (587 [5·7%] vs 707 [6·9%]; p=0·0005), a marginally significant reduction in other vascular deaths (194 [1·9%] vs 230 [2·2%]; p=0·07), and a non-significant reduction in non-vascular deaths (547 [5·3%] vs 570 [5·6%]; p=0·4). There were highly significant reductions of about one-quarter in the first event rate for nonfatal myocardial infarction or coronary death (898 [8·7%] vs 1212 [11·8%]; p<0·0001), for non-fatal or fatal stroke (444 [4·3%] vs 585 [5·7%]; p<0·0001), and for coronary or noncoronary revascularisation (939 [9·1%] vs 1205 [11·7%]; p<0·0001). For the first occurrence of any of these major vascular events, there was a definite 24% (SE 3; 95% CI 19–28) reduction in the event rate (2033 [19·8%] vs 2585 [25·2%] affected individuals; p<0·0001). During the first year the reduction in major vascular events was not significant, but subsequently it was highly significant during each separate year. The proportional reduction in the event rate was similar (and significant) in each subcategory of participant studied, including: those without diagnosed coronary disease who had cerebrovascular disease, or had peripheral artery disease, or had diabetes; men and, separately, women; those aged either under or over 70 years at entry; and—most notably—even those who presented with LDL cholesterol below 3·0 mmol/L (116 mg/dL), or total cholesterol below 5·0 mmol/L (193 mg/dL). The benefits of simvastatin were additional to those of other cardioprotective treatments. The annual excess risk of myopathy with this regimen was about 0·01%. There were no significant adverse effects on cancer incidence or on hospitalisation for any other non-vascular cause. Interpretation: Adding simvastatin to existing treatments safely produces substantial additional benefits for a wide range of high-risk patients, irrespective of their initial cholesterol concentrations. Allocation to 40 mg simvastatin daily reduced the rates of myocardial infarction, of stroke, and of revascularisation by about one-quarter. After making allowance for non-compliance, actual use of this regimen would probably reduce these rates by about one-third. Hence, among the many types of high-risk individual studied, 5 years of simvastatin would prevent about 70–100 people per 1000 from suffering at least one of these major vascular events (and longer treatment should produce further benefit). The size of the 5-year benefit depends chiefly on such individuals' overall risk of major vascular events, rather than on their blood lipid concentrations alone
Establishment of the 1st World Health Organization International Standard for Plasmodium falciparum DNA for nucleic acidamplification technique (NAT)-based assays
No full textBackground: In order to harmonize results for the detection and quantification of Plasmodium
falciparum DNA by nucleic acid amplification technique (NAT)-based assays, a World Health
Organization (WHO) collaborative study was performed, evaluating a series of candidate standard
preparations.
Methods: Fourteen laboratories from 10 different countries participated in the collaborative
study. Four candidate preparations based upon blood samples parasitaemic for P. falciparum were
evaluated in the study. Sample AA was lyophilized, whilst samples BB, CC and DD were liquid/
frozen preparations. The candidate standards were tested by each laboratory at a range of dilutions
in four independent assays, using both qualitative and quantitative NAT-based assays. The results
were collated and analysed statistically.
Results: Twenty sets of data were returned from the participating laboratories and used to
determine the mean P. falciparum DNA content for each sample. The mean log10 "equivalents"/ml
were 8.51 for sample AA, 8.45 for sample BB, 8.35 for sample CC, and 5.51 for sample DD. The
freeze-dried preparation AA, was examined by accelerated thermal degradation studies and found
to be highly stable.
Conclusion: On the basis of the collaborative study, the freeze-dried material, AA (NIBSC code
No. 04/176) was established as the 1st WHO International Standard for P. falciparum DNA NATbased
assays and has been assigned a potency of 109 International Units (IU) per ml. Each vial
contains 5 × 108 IU, equivalent to 0.5 ml of material after reconstitution
A Framework for collaborative writing with recording and post-meeting retrieval capabilities
No full textFrom a HCI perspective, elucidating and supporting the context in which collaboration takes place is key to implementing successful collaborative systems. Synchronous collaborative writing usually takes place in contexts involving a “meeting” of some sort. Collaborative writing meetings can be face-to-face or, increasingly, remote Internet-based meetings. The latter presents software developers with the possibility of incorporating multimedia recording and information retrieval capabilities into the collaborative environment. The collaborative writing that ensues can be seen as an activity encompassing asynchronous as well as synchronous aspects. In order for revisions, information retrieval and other forms of post-meeting, asynchronous work to be effectively supported, the synchronous collaborative editor must be able to appropriately detect and record meeting metadata. This paper presents a collaborative editor that supports recording of user actions and explicit metadata production. Design and technical implications of introducing such capabilities are discussed with respect to document segmentation, consistency control, and awareness mechanisms
The UN-SUSTAINABLE Match in HCV Recipients. Evidences from the Italian D-MELD Study on Balancing Donor-Recipient Risk Factors
No full textThe UN-SUSTAINABLE Match in HCV Recipients. Evidences from the Italian D-MELD Study on Balancing Donor-Recipient Risk Factor
SARS-CoV-2 infection and venous thromboembolism after surgery: an international prospective cohort study
No full textSARS-CoV-2 has been associated with an increased rate of venous thromboembolism in critically ill patients. Since surgical patients are already at higher risk of venous thromboembolism than general populations, this study aimed to determine if patients with peri-operative or prior SARS-CoV-2 were at further increased risk of venous thromboembolism. We conducted a planned sub-study and analysis from an international, multicentre, prospective cohort study of elective and emergency patients undergoing surgery during October 2020. Patients from all surgical specialties were included. The primary outcome measure was venous thromboembolism (pulmonary embolism or deep vein thrombosis) within 30 days of surgery. SARS-CoV-2 diagnosis was defined as peri-operative (7 days before to 30 days after surgery); recent (1-6 weeks before surgery); previous (>= 7 weeks before surgery); or none. Information on prophylaxis regimens or pre-operative anti-coagulation for baseline comorbidities was not available. Postoperative venous thromboembolism rate was 0.5% (666/123,591) in patients without SARS-CoV-2; 2.2% (50/2317) in patients with peri-operative SARS-CoV-2; 1.6% (15/953) in patients with recent SARS-CoV-2; and 1.0% (11/1148) in patients with previous SARS-CoV-2. After adjustment for confounding factors, patients with peri-operative (adjusted odds ratio 1.5 (95%CI 1.1-2.0)) and recent SARS-CoV-2 (1.9 (95%CI 1.2-3.3)) remained at higher risk of venous thromboembolism, with a borderline finding in previous SARS-CoV-2 (1.7 (95%CI 0.9-3.0)). Overall, venous thromboembolism was independently associated with 30-day mortality (5.4 (95%CI 4.3-6.7)). In patients with SARS-CoV-2, mortality without venous thromboembolism was 7.4% (319/4342) and with venous thromboembolism was 40.8% (31/76). Patients undergoing surgery with peri-operative or recent SARS-CoV-2 appear to be at increased risk of postoperative venous thromboembolism compared with patients with no history of SARS-CoV-2 infection. Optimal venous thromboembolism prophylaxis and treatment are unknown in this cohort of patients, and these data should be interpreted accordingly
Exploratory talk within collaborative small groups in mathematics
No full textThis report describes one aspect of a wider research study on exploratory talk within collaborative small groups in secondary mathematics lessons. It outlines students’ views of using collaborative activity to learn mathematics. The fuller research study explores the extent to which exploratory talk occurs in collaborative peer groups in secondary mathematics classrooms
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