392 research outputs found
Towards a Strategy to Fight the Computer Science (Cs) Declining Phenomenon
International audienceEuropean students have give reasons why they reject computer science (CS) as a program of study in higher education [1]. The constant decrease in the number of students choosing to study this subject has had consequences in different European sectors, such as the economic sector or the education sector, among others [2]. Some of the reasons for this rejection are related to the degree of difficulty of the skills that are needed to master CS. This study aims to identify these skills by firstly comparing CS curricula across several European universities and then comparing these curricula with same level programs in other areas of study. It will highlight some misconceptions students have concerning CS programs and will demonstrate that Technology Enhanced Learning (TEL) may have a major role to play in combating the decline of CS professionals by providing dynamic learning environments; where students can acquire the knowledge and skills which are unique to the field of CS
Sensitivity of the lateral flow urine lipoarabinomannan assay in ambulant adults with advanced HIV disease: data from the TB Fast Track study.
BACKGROUND: WHO guidelines recommend the lateral flow urine lipoarabinomannan assay (LF-LAM) for TB diagnosis in hospitalised HIV-positive individuals. The role of LF-LAM among ambulant patients remains less well defined. We investigated the sensitivity of LF-LAM among ambulant HIV-positive adults in primary health clinics in South Africa. METHODS: We enrolled adults (aged â„18 y) with CD4 counts of â€150 cells/mm3 who had not received TB treatment or antiretroviral therapy in the preceding 3 or 6 mo, respectively. Research nurses performed the LF-LAM test on freshly voided urine. Results were compared with a reference standard of positive mycobacterial culture (sputum or urine). RESULTS: Of 1505 (54.5% female; median age 37 y; median CD4 count 73 cells/mm3) participants, 973 (64.7%) had a mycobacterial culture result; 105/973 (10.8%) were positive for Mycobacterium tuberculosis. LF-LAM sensitivity was 41.9% (95% CI 32.3 to 51.9%) and 19.0% (95% CI 12.0 to 27.9%) using grade 1+ and grade 2+ cut-off points, respectively. Sensitivity increased with severe immunosuppression and in the presence of poor prognostic indicators (low haemoglobin, body mass index). CONCLUSIONS: When used as the only TB diagnostic test, LF-LAM sensitivity is suboptimal, particularly using the grade 2+ cut-off. More sensitive tests for TB are needed that can be used in primary care settings
Verbal autopsy-assigned causes of death among adults being investigated for TB in South Africa
Aaron S. Karat - ORCID 0000-0001-9643-664X
https://orcid.org/0000-0001-9643-664XBackground: Adults being investigated for TB in South Africa experience high mortality, yet causes of death
(CoD) are not well defined. We determined CoD in this population using verbal autopsy (VA), and compared
HIV- and TB-associated CoD using physician-certified verbal autopsy (PCVA) and InterVA-4 software.Methods: All contactable consenting caregivers of participants who died during a trial comparing Xpert MTB/
RIF to smear microscopy were interviewed using the WHO VA tool. CoD were assigned using PCVA and
InterVA-4. Kappa statistic (K) and concordance correlation coefficient (CCC) were calculated for comparison.Results: Among 231 deaths, relatives of 137 deceased were interviewed. Of the 137 deceased 76 (55.4%)
were males, median age 41 years (IQR 33â50). PCVA assigned 70 (51.1%) TB immediate CoD (44 [62.8%] pulmonary TB; 26 [37.1%] extra-pulmonary TB); 21 (15.3%) HIV/AIDS-related; and 46 (33.5%) other CoD.
InterVA-4 assigned 48 (35.0%) TB deaths; 49 (35.7%) HIV/AIDS-related deaths; and 40 (29.1%) other CoD.
Agreement between PCVA and InterVA-4 CoD was slight at individual level (K=0.20; 95% CI 0.10â0.30) and
poor at population level (CCC 0.67; 95% CI 0.38â0.99).Conclusions: TB and HIV are leading CoD among adults being investigated for TB. PCVA and InterVA agreement at individual level was slight and poor at population level. VA methodology needs further development
where TB and HIV are common.This work was supported by Bill & Melinda Gates Foundation [Grant Number: OPP1034523] for funding the study.https://doi.org/10.1093/trstmh/trw058110pubpub
On anomalies in classical dynamical systems
The definition of "classical anomaly" is introduced. It describes the
situation in which a purely classical dynamical system which presents both a
lagrangian and a hamiltonian formulation admits symmetries of the action for
which the Noether conserved charges, endorsed with the Poisson bracket
structure, close an algebra which is just the centrally extended version of the
original symmetry algebra. The consistency conditions for this to occur are
derived. Explicit examples are given based on simple two-dimensional models.
Applications of the above scheme and lines of further investigations are
suggested.Comment: arXiv version is already officia
Time to change the way we think about tuberculosis infection prevention and control in health facilities: insights from recent research
In clinical settings where airborne pathogens, such as Mycobacterium tuberculosis, are prevalent, they constitute an important threat to health workers and people accessing healthcare. We report key insights from a 3-year project conducted in primary healthcare clinics in South Africa, alongside other recent tuberculosis infection prevention and control (TB-IPC) research. We discuss the fragmentation of TB-IPC policies and budgets; the characteristics of individuals attending clinics with prevalent pulmonary tuberculosis; clinic congestion and patient flow; clinic design and natural ventilation; and the facility-level determinants of the implementation (or not) of TB-IPC interventions. We present modeling studies that describe the contribution of M. tuberculosis transmission in clinics to the community tuberculosis burden and economic evaluations showing that TB-IPC interventions are highly cost-effective. We argue for a set of changes to TB-IPC, including better coordination of policymaking, clinic decongestion, changes to clinic design and building regulations, and budgeting for enablers to sustain implementation of TB-IPC interventions. Additional research is needed to find the most effective means of improving the implementation of TB-IPC interventions; to develop approaches to screening for prevalent pulmonary tuberculosis that do not rely on symptoms; and to identify groups of patients that can be seen in clinic less frequently
Performance of verbal autopsy methods in estimating HIV-associated mortality among adults in South Africa
Aaron S. Karat - ORCID 0000-0001-9643-664X
https://orcid.org/0000-0001-9643-664XIntroduction Verbal autopsy (VA) can be integrated into civil registration and vital statistics systems, but its accuracy in determining HIV-associated causes of death (CoD) is uncertain. We assessed the sensitivity and specificity of VA questions in determining HIV status and antiretroviral therapy (ART) initiation and compared HIV-associated mortality fractions assigned by different VA interpretation methods.Methods Using the WHO 2012 instrument with added ART
questions, VA was conducted for deaths among adults with
known HIV status (356 HIV positive and 103 HIV negative)
in South Africa. CoD were assigned using physiciancertified VA (PCVA) and computer-coded VA (CCVA)
methods and compared with documented HIV statusResults The sensitivity of VA questions in detecting HIV
status and ART initiation was 84.3% (95% CI 80 to 88) and
91.0% (95% CI 86 to 95); 283/356 (79.5%) HIV-positive
individuals were assigned HIV-associated CoD by PCVA,
166 (46.6%) by InterVA-4.03, 201 (56.5%) by InterVA-5,
and 80 (22.5%) and 289 (81.2%) by SmartVA-Analyze
V.1.1.1 and V.1.2.1. Agreement between PCVA and older
CCVA methods was poor (chance-corrected concordance
[CCC] <0; cause-specific mortality fraction [CSMF]
accuracy â€56%) but better between PCVA and updated
methods (CCC 0.21â0.75; CSMF accuracy 65%â98%).
All methods were specific (specificity 87% to 96%) in
assigning HIV-associated CoD.Conclusion All CCVA interpretation methods
underestimated the HIV-associated mortality fraction
compared with PCVA; InterVA-5 and SmartVA-Analyze
V.1.2.1 performed better than earlier versions. Changes
to VA methods and classification systems are needed to
track progress towards targets for reducing HIV-associated
mortality,This study was funded by a grant from the Bill & Melinda Gates Foundation (OPP1083118).http://dx.doi.org/10.1136/bmjgh-2018-0008333pubpub
âYou have to change your whole lifeâ: a qualitative study of the dynamics of treatment adherence among adults with tuberculosis in the United Kingdom
Karina Kielmann - ORCID: 0000-0001-5519-1658
https://orcid.org/0000-0001-5519-1658Aaron S. Karat - ORCID: 0000-0001-9643-664X
https://orcid.org/0000-0001-9643-664XVoR deposited 2021-04-13.Maintaining adherence to treatment for tuberculosis (TB) is essential if the disease is to be eliminated. As part of formative research to develop an intervention to improve adherence, we documented the lived experiences of adults receiving anti-TB treatment (ATT) in three UK cities and examined how personal, social, and structural circumstances interacted to impact on individualsâ adherence to treatment. Using a topic guide that explored social circumstances and experiences of TB care, we conducted in-depth interviews with 18 adults (six women) who were being or had been treated for TB (patients) and four adults (all women) who were caring for a friend, relative, or partner being treated for TB (caregivers). We analysed transcripts using an adapted framework method that classified factors affecting adherence as personal, social, structural, health systems, or treatment-related. Eleven of 18 patients were born outside the UK (in South, Central, and East Asia, and Eastern and Southern Africa); among the seven who were UK-born, four were Black, Asian, or Minority Ethnic and three were White British. TB and its treatment were often disruptive: in addition to debilitating symptoms and side effects of ATT, participants faced job insecurity, unstable housing, stigma, social isolation, worsening mental health, and damaged relationships. Those who had a strong support network, stable employment, a routine that could easily be adapted, a trusting relationship with their TB team, and clear understanding of the need for treatment reported finding it easier to adhere to ATT. Changes in circumstances sometimes had dramatic effects on an individualâs ability to take ATT; participants described how the impact of certain acute events (e.g., the onset of side effects or fatigue, episodes of stigmatisation, loss of income) were amplified by their timing or through their interaction with other elements of the individualâs life. We suggest that the dynamic and fluctuating nature of these factors necessitates comprehensive and regular review of needs and potential problems, conducted before and during ATT; this, coupled with supportive measures that consider (and seek to mitigate) the influence of social and structural factors, may help improve adherence.This work was supported by the National Institute for Health Research (NIHR) Health Technology Assessment Programme, UK grant number 16/88/06.https://doi.org/10.1016/j.jctube.2021.10023323pubpu
Renormalized Path Integral for the Two-Dimensional Delta-Function Interaction
A path-integral approach for delta-function potentials is presented.
Particular attention is paid to the two-dimensional case, which illustrates the
realization of a quantum anomaly for a scale invariant problem in quantum
mechanics. Our treatment is based on an infinite summation of perturbation
theory that captures the nonperturbative nature of the delta-function bound
state. The well-known singular character of the two-dimensional delta-function
potential is dealt with by considering the renormalized path integral resulting
from a variety of schemes: dimensional, momentum-cutoff, and real-space
regularization. Moreover, compatibility of the bound-state and scattering
sectors is shown.Comment: 26 pages. The paper was significantly expanded and numerous equations
were added for the sake of clarity; the main results and conclusions are
unchange
Effect of a rigid nonpolar solute on the splay, bend elastic constants and on rotational viscosity coefficient of 4-4^\prime -n-octyl-cyanobiphenyl
The effect of a rigid nonpolar non-mesogenic solute, ``biphenyl'' which is
(C_{6}H_{5}-C_{6}H_{5}), on the splay and bend elastic constants and on the
rotational viscosity coefficient of (4,4^{\prime})-n-octyl-cyano biphenyl (8CB)
is reported. The experiments involve the measurement of voltage dependence of
capacitance of a cell filled with the mixture. Anomalous behavior of both
(K_{11}) and (\Delta \epsilon) near the (N-S_{A}) transition have been
observed.Comment: RevTeX - 8 figures. Accepted to be published in Physical Review
- âŠ