2,159 research outputs found
Recommended from our members
Machina ex deos. Successes and challenges of implementing mobile computing technologies for development. The experience of nine Indian village health projects using a project-issued mobile application
As mobile computing technologies become increasingly functional and affordable, global donor and local development organizations find ways to justify and fund their use in grassroots development work. This dissertation asks two questions: (1) In resource-constrained social sector settings, what project features govern and structure use of work-issued mobile devices? And: (2) How do decision-makers adjust to maximize the benefit of newly-introduced devices while minimizing new burdens to the project and project staff? More simply, what variables under social sector projectsâ control might promote successful use of information and communication technologies in development (ICTD) projects? This research represents systematic, qualitative comparison of nine extended deployments of a popular mobile health application, CommCare. Each studied project deployed devices loaded with CommCare to health workers in India as a supportive job aid and/or a data collection tool to help monitor beneficiary populationsâ health status and frontline workersâ work. This dissertation examines the conditions under which these health workers were able and willing to use CommCare devices in their jobs, and whether and how they deviated from the use of those devices prescribed by their supervisors. Primary data for this study come from 62 in-depth, semi-structured interviews, extensive review of project documents, and personal observations from field study in India over six months in 2013. Employing a sociotechnical lens and a principal agent model, my data support expectations that use of CommCare devices would help align community health workersâ behavior with their supervisorsâ organization and mission-related priorities. Use of the devices improved health workersâ professional competence and improved communications, data quality, and data access. These improvements facilitated project supervisorsâ monitoring of health workers and beneficiaries, and fundersâ monitoring of projects. Contradicting expectations, use of CommCare devices also weakened organizational oversight and control through new data challenges and increased health worker autonomy in their personal and professional lives. These dual benefits and challenges ultimately served the overall projectsâ missions.Public Affair
Training the next generation of pluripotent stem cell researchers
Human pluripotent stem cells (PSCs) have the unique properties of being able to proliferate indefinitely in their undifferentiated state and of being able to differentiate into any somatic cell type. These cells are thus posited to be extremely useful for furthering our understanding of both normal and abnormal human development, providing a human cell preparation that can be used to screen for new reagents or therapeutic agents, and generating large numbers of differentiated cells that can be used for transplantation purposes. PSCs in culture have a specific morphology and they express characteristic surface antigens and nuclear transcription factors; thus, PSC culture is very specific and requires a core skill set for successful propagation of these unique cells. Specialized PSC training courses have been extremely valuable in seeding the scientific community with researchers that possess this skill set
Wettability versus roughness of engineering surfaces
Wetting of real engineering surfaces occurs in many industrial applications (liquid coating, lubrication, printing, painting, ...). Forced and natural wetting can be beneficial in many cases, providing lubrication and therefore reducing friction and wear. However the wettability of surfaces can be strongly affected by surface roughness. This influence can be very significant for static and dynamic wetting [1]. In this paper authors experimentally investigate the roughness influence on contact angle measurements and propose a simple model combining Wenzel and Cassie-Baxter theories with simple 2D roughness profile analysis. The modelling approach is applied to real homogeneous anisotropic surfaces, manufactured on a wide range of engineering materials including aluminium alloy, iron alloy, copper, ceramic, plastic (poly-methylmethacrylate: PMMA) and titanium alloy
Behavior of bulk high-temperature superconductors of finite thickness subjected to crossed magnetic fields
Crossed magnetic field effects on bulk high-temperature superconductors have
been studied both experimentally and numerically. The sample geometry
investigated involves finite-size effects along both (crossed) magnetic field
directions. The experiments were carried out on bulk melt-processed Y-Ba-Cu-O
(YBCO) single domains that had been pre-magnetized with the applied field
parallel to their shortest direction (i.e. the c-axis) and then subjected to
several cycles of the application of a transverse magnetic field parallel to
the sample ab plane. The magnetic properties were measured using orthogonal
pick-up coils, a Hall probe placed against the sample surface and
Magneto-Optical Imaging (MOI). We show that all principal features of the
experimental data can be reproduced qualitatively using a two-dimensional
finite-element numerical model based on an E-J power law and in which the
current density flows perpendicularly to the plane within which the two
components of magnetic field are varied. The results of this study suggest that
the suppression of the magnetic moment under the action of a transverse field
can be predicted successfully by ignoring the existence of flux-free
configurations or flux-cutting effects. These investigations show that the
observed decay in magnetization results from the intricate modification of
current distribution within the sample cross-section. It is also shown that the
model does not predict any saturation of the magnetic induction, even after a
large number (~ 100) of transverse field cycles. These features are shown to be
consistent with the experimental data.Comment: 41 pages, 9 figures, accepted in Phys. Rev. B Changes : 8 references
added, a few precisions added, some typos correcte
Decision and Discovery in Defining âDiseaseâ
This version (May 17, 2005) was published in its final form as:
Schwartz PH. Decision and discovery in defining 'disease'. In: Kincaid H, McKitrick J, editors. Establishing medical reality: essays in the metaphysics and epistemology of biomedical science. Dordrecht: Springer; 2007. p. 47-63. http://dx.doi.org/10.1007/1-4020-5216-2_5The debate over how to analyze the concept of disease has often centered on the question of whether to include a reference to values, in particular the âdisvalueâof diseases, or whether to avoid such notions. âNormativists,âsuch as King ([1954], 1981) and Culver and Gert (1982) emphasize the undesirability of diseases, while âNaturalists,â most prominently Christopher Boorse (1977, 1987, 1997), instead require just the presence of biological dysfunction. The debate between normativism and naturalism often deteriorates into stalemate, with each side able to point out significant problems with the other. It starts to look as if neither approach can work. In this paper, I argue that the standoff stems from deeply questionable assumptions that have been used to formulate the opposing positions and guide the debate. In the end, I propose an alternative set of guidelines that offer a more constructive way to devise and compare theories
Will the starless cores in Chamaeleon I and III turn prestellar?
The nearby Chamaeleon molecular cloud complex is a good laboratory to study
the process of low-mass star formation since it consists of three clouds with
very different properties. Cha III does not show any sign of star formation,
while star formation has been very active in Cha I and may already be
finishing. Our goal is to determine whether star formation can proceed in Cha
III, and to compare the results to our recent survey of Cha I. We used the
Large APEX Bolometer Array (LABOCA) to map Cha III in dust continuum emission
at 870 micron. 29 sources are extracted from the map, all of them being
starless. The starless cores are found down to a visual extinction of 1.9 mag,
in marked contrast with other molecular clouds, including Cha I. Apart from
this difference, the Cha III starless cores share very similar properties with
those found in Cha I. At most two sources have a mass larger than the critical
Bonnor-Ebert mass, which suggests that the fraction of prestellar cores is very
low, even lower than in Cha I. Only the most massive sources are candidate
prestellar cores, in agreement with the correlation found earlier in the Pipe
nebula. The mass distribution of the 85 starless cores of Cha I and III that
are not candidate prestellar cores is consistent with a single power law down
to the 90% completeness limit, with an exponent close to the Salpeter value. A
fraction of the starless cores in Cha I and III may still grow in mass and
become gravitationally unstable. Based on predictions of numerical simulations
of turbulent molecular clouds, we estimate that at most 50% and 20% of the
starless cores of Cha I and III, respectively, may form stars. The LABOCA
survey reveals that Cha III, and Cha I to some extent too, is a prime target to
study the formation of prestellar cores, and thus the onset of star formation.
(abridged).Comment: Accepted for publication in A&A. 22 pages, 16 figures, 4 tables. A
version with high-resolution figures is available on request to the first
autho
Efficacy of topical cobalt chelate CTC-96 against adenovirus in a cell culture model and against adenovirus keratoconjunctivitis in a rabbit model
BACKGROUND: Adenovirus (Ad), associated with significant morbidity, has no topical treatment. A leading CTC compound (CTC-96), a Co(III )chelate, was found to have potent in vitro and in vivo antiviral efficacy against herpes viruses. In this study CTC-96 is being tested for possible anti-Adenovirus activity. METHODS: The biological anti-adenovirus activity of CTC-96 in concentrations from 5 to 250 ug/ml, was evaluated initially by viral inactivation (viral exposure to CTC-96 followed by dilution and inoculation of cells), virucidal (viral exposure to CTC-96 and inoculation of cells without dilution) and antiviral (effect of CTC-96 on previously adsorbed virus) plaque assays on HeLa (human cervical carcinoma), A549 (human lung carcinoma) and SIRC (rabbit corneal) cells. After verifying the antiviral activity, New Zealand White rabbits were infected with Ad-5 into: 1) the anterior cul-de-sac scarifying the conjunctiva (Group "C+"); 2) the anterior cul-de-sac scarifying the conjunctiva and cornea (Group "CC+"); 3) the stroma (Group "CI+"). Controls were sham-infected ("C-", "CC-", "CI-"). Other rabbits, after "CC", were treated for 21 days with: 1) placebo, 9x/day ("-"); 2) CTC-96, 50 ug/ml, 9x/day ("50/9"); CTC-96, 50 ug/ml, 6x/day ("50/6"); CTC-96, 25 ug/ml, 6x/day ("25/6"). All animals were monitored via examination and plaque assays. RESULTS: In vitro viral inactivation, virucidal and antiviral assays all demonstrated CTC-96 to be effective against Adenvirus type 5 (ad-5). The in vivo model of Ad keratoconjunctivitis most similar to human disease and producing highest viral yield was "CC". All eyes (6/6) developed acute conjunctivitis. "CI" yielded more stromal involvement (1/6) and iritis (5/6), but lower clinical scores (area Ă severity). Infection via "C" was inconsistent (4/6). Fifty (50) ug/ml was effective against Ad-5 at 6x, 9x dosings while 25 ug/ml (6x) was only marginally effective. CONCLUSION: CTC-96 demonstrated virucidal activity against Ad5 in tissue culture with HeLa, A549 and SIRC cell lines. Animal Model Development: 1) "CC" produced conjunctival infection with occasional keratitis similar to human disease; "CI" yielded primarily stromal involvement; 2) "C" consistently produced neither conjunctivitis nor keratitis. CTC Testing: 1) Conjunctivitis in all eyes; 2) Resolution fastest in "50/9" ("50/9". "50/6" > "25/6" > "-"); 3) Efficacy in "50/6" was not statistically different than "50/9"; 4) Conjunctival severity was lower in treatment groups then controls; 5) Little corneal or intra-ocular changes were noted
The knowledge and expectations of parents about the role of antibiotic treatment in upper respiratory tract infection â a survey among parents attending the primary physician with their sick child
BACKGROUND: Upper respiratory tract infections (URTI) are common. The etiologic factor is usually viral, but many physicians prescribe antibiotics. We aimed to evaluate parents' expectations of and knowledge about the role of antibiotics in childhood URTI. METHODS: The study was conducted in thirteen primary care pediatric clinics. Parents of children aged 3 months to 6 years who attended with URTI symptoms were included when it was the first attendance in the current illness. Questionnaire about the current illness, reasons for attending and expectations from the visit, knowledge about URTI was filled before the visit. RESULTS: In 122 visits the average age was 2.8 ± 1.9 years. The main reasons for the visit were to avoid complications (81%) and to be examined (78%). Expected treatment was: cough suppressants (64%), anti-congestants (57%), paracetamol (56%), natural remedies (53%) and antibiotics (25%). In 28% the child had received antibiotics in past URTI. Only 37% thought that antibiotics would not help in URTI and 27% knew that URTI is a self-limited disease. 61% knew that URTI is a viral disease. Younger parental age and higher education were associated with lower expectations to receive antibiotics (p = 0.01, p < 0.005 respectively). While previous antibiotic treatment (p < 0.001), past perceived complications (p = 0.05) and the thought that antibiotics help in URTI (p < 0.001) were associated with a greater expectation for antibiotics. CONCLUSIONS: A quarter of the parents attending the physician with URTI are expecting to get antibiotics. Predictors were lower education, older parental age, receiving antibiotics in the past and the belief that antibiotics help in URTI
Points to consider in cardiovascular disease risk management among patients with rheumatoid arthritis living in South Africa, an unequal middle income country
ABSTRACT: Background: It is plausible that optimal cardiovascular disease (CVD) risk management differs in patients with rheumatoid arthritis (RA) from low or middle income compared to high income populations. This study aimed at producing evidence-based points to consider for CVD prevention in South African RA patients.
Methods: Five rheumatologists, one cardiologist and one epidemiologist with experience in CVD risk management in RA patients, as well as two patient representatives, two health professionals and one radiologist, one rheumatology fellow and 11 rheumatologists that treat RA patients regularly contributed. Systematic literature searches were performed and the level of evidence was determined according to standard guidelines.
Results: Eighteen points to consider were formulated. These were grouped into 6 categories that comprised overall CVD risk assessment and management (n=4), and specific interventions aimed at reducing CVD risk including RA control with disease modifying anti-rheumatic drugs, glucocorticoids and non-steroidal anti-inflammatory drugs (n=3), lipid lowering agents (n=8), antihypertensive drugs (n=1), low dose aspirin (n=1) and lifestyle modification (n=1). Each point to consider differs partially or completely from recommendations previously reported for CVD risk management in RA patients from high income populations. Currently recommended CVD risk calculators do not reliably identify South African black RA patients with very high-risk atherosclerosis as represented by carotid artery plaque presence on ultrasound.
Conclusions: Our findings indicate that optimal cardiovascular risk management likely differs substantially in RA patients from low or middle income compared to high income populations. There is an urgent need for future multicentre longitudinal studies on CVD risk in black African patients with RA.The first meeting held amongst local Rheumatologists was funded by the South African Arthritis and Rheumatology Association. The studies by Professor GonzĂĄlez-Gay have been supported by grants from âFondo de Investigaciones Sanitariasâ PI06/0024, PS09/00748, PI12/00060, PI15/00525, PI18/00043, and RD12/0009/0013 and RD16/0012 (RIER) from âInstituto de Salud Carlos IIIâ (ISCIII) (Spain), co-funded by FEDER funds
- âŠ