2,371 research outputs found
Implementation of digital pheromones in PSO accelerated by commodity Graphics Hardware
In this paper, a model for Graphics Processing Unit (GPU) implementation of Particle Swarm Optimization (PSO) using digital pheromones to coordinate swarms within ndimensional design spaces is presented. Previous work by the authors demonstrated the capability of digital pheromones within PSO for searching n-dimensional design spaces with improved accuracy, efficiency and reliability in both serial and parallel computing environments using traditional CPUs. Modern GPUs have proven to outperform the number of floating point operations when compared to CPUs through inherent data parallel architecture and higher bandwidth capabilities. The advent of programmable graphics hardware in the recent times further provided a suitable platform for scientific computing particularly in the field of design optimization. However, the data parallel architecture of GPUs requires a specialized formulation for leveraging its computational capabilities. When the objective function computations are appropriately formulated for GPUs, it is theorized that the solution efficiency (speed) can be significantly increased while maintaining solution accuracy. The development of this method together with a number of multi-modal unconstrained test problems are tested and presented in this paper
Molecular and mass spectroscopic analysis of isotopically labeled organic residues
Experimental studies aimed at understanding the evolution of complex organic molecules on interstellar grains were performed. The photolysis of frozen gas mixtures of various compositions containing H2O, CO, NH3, and CH4 was studied. These species were chosen because of their astrophysical importance as deducted from observational as well as theoretical studies of ice mantles on interstellar grains. These ultraviolet photolyzed ices were warmed up in order to produce refractory organic molecules like the ones formed in molecular clouds when the icy mantles are being irradiated and warmed up either by a nearby stellar source or impulsive heating. The laboratory studies give estimates of the efficiency of production of such organic material under interstellar conditions. It is shown that the gradual carbonization of organic mantles in the diffuse cloud phase leads to higher and higher visual absorptivity - yellow residues become brown in the laboratory. The obtained results can be applied to explaining the organic components of comets and their relevance to the origin of life
Report of the International Society of Hypertension (ISH) Hypertension Teaching Seminar organized by the ISH Africa Regional Advisory Group: Maputo, Mozambique, 2016
The International Society of Hypertension (ISH), in fulfilment of its mission of promoting hypertension control and prevention and also of advancing knowledge globally, organizes hypertension teaching seminars or ‘summer schools’ worldwide through the ISH Regional Advisory Groups. In Africa, seven of such seminars have been organized. This is a report of the eighth seminar held in Maputo, Mozambique, April, 2016. The seminar was attended by over 65 participants from 11 African countries. The Faculty consisted of 11 international hypertension experts. The eighth African hypertension seminar was a great success as confirmed by a pre- and post-test questionnaire
Effectiveness and Acceptability of a Mobile Phone Text Messaging Intervention to Improve Blood Pressure Control (TEXT4BP) among Patients with Hypertension in Nepal: A Feasibility Randomised Controlled Trial
Background: Uncontrolled blood pressure (BP) is the leading cause of preventable deaths in low- and middle-income countries. mHealth interventions, such as mobile phone text messaging, are a promising tool to improve BP control, but research on feasibility and effectiveness in resource-limited settings remains limited. Objective: This feasibility study assessed the effectiveness and acceptability of a mobile phone text messaging intervention (TEXT4BP) to improve BP control and treatment adherence among patients with hypertension in Nepal. Methods: The TEXT4BP study was a two-arm, parallel-group, unblinded, randomised controlled pilot trial that included 200 participants (1:1) (mean age: 50.5 years, 44.5% women) with hypertension at a tertiary referral hospital in Kathmandu, Nepal. Patients in the intervention arm (n = 100) received text messages three times per week for three months. The control arm (n = 100) received standard care. The COM-B model informed contextual co-designed text messages. Primary outcomes were change in BP and medication adherence at three months. Secondary outcomes included BP control, medication adherence self-efficacy and knowledge of hypertension. A nested qualitative study assessed the acceptability of the intervention. Results: At three months, the intervention group had greater reductions in systolic and diastolic BP vs usual care [-7.09/-5.86 (p ≤ 0.003) vs -0.77/-1.35 (p ≥ 0.28) mmHg] [adjusted difference: systolic β = -6.50 (95% CI, -12.6; -0.33) and diastolic BP β = -4.60 (95% CI, -8.16; -1.04)], coupled with a greater proportion achieving target BP (70% vs 48%, p = 0.006). The intervention arm showed an improvement in compliance to antihypertensive therapy (p < 0.001), medication adherence (p < 0.001), medication adherence self-efficacy (p = 0.023) and knowledge on hypertension and its treatment (p = 0.013). Participants expressed a high rate of acceptability and desire to continue the TEXT4BP intervention. Conclusion: The TEXT4BP study provides promising evidence that text messaging intervention is feasible, acceptable, and effective to improve BP control in low-resource settings
Is it time to reappraise blood pressure thresholds and targets? Statement from the international society of hypertension - a global perspective
No abstract available
A New Galactic 6cm Formaldehyde Maser
We report the detection of a new H2CO maser in the massive star forming
region G23.71-0.20 (IRAS 18324-0820), i.e., the fifth region in the Galaxy
where H2CO maser emission has been found. The new H2CO maser is located toward
a compact HII region, and is coincident in velocity and position with 6.7 GHz
methanol masers and with an IR source as revealed by Spitzer/IRAC GLIMPSE data.
The coincidence with an IR source and 6.7 GHz methanol masers suggests that the
maser is in close proximity to an embedded massive protostar. Thus, the
detection of H2CO maser emission toward G23.71-0.20 supports the trend that
H2CO 6cm masers trace molecular material very near young massive stellar
objects.Comment: Accepted for publication in The Astrophysical Journal Letter
Orbiting Resonances and Bound States in Molecular Scattering
A family of orbiting resonances in molecular scattering is globally described
by using a single pole moving in the complex angular momentum plane. The
extrapolation of this pole at negative energies gives the location of the bound
states. Then a single pole trajectory, that connects a rotational band of bound
states and orbiting resonances, is obtained. These complex angular momentum
singularities are derived through a geometrical theory of the orbiting. The
downward crossing of the phase-shifts through pi/2, due to the repulsive region
of the molecular potential, is estimated by using a simple hard-core model.
Some remarks about the difference between diffracted rays and orbiting are also
given.Comment: 18 pages, 3 figures, to appear in Physical Review
Methanol masers : Reliable tracers of the early stages of high-mass star formation
The GLIMPSE and MSX surveys have been used to examine the mid-infrared
properties of a statistically complete sample of 6.7 GHz methanol masers. The
GLIMPSE point sources associated with methanol masers are clearly distinguished
from the majority, typically having extremely red mid-infrared colors, similar
to those expected of low-mass class 0 young stellar objects. The intensity of
the GLIMPSE sources associated with methanol masers is typically 4 magnitudes
brighter at 8.0 micron than at 3.6 micron. Targeted searches towards GLIMPSE
point sources with [3.6]-[4.5] > 1.3 and an 8.0 micron magnitude less than 10
will detect more than 80% of class II methanol masers. Many of the methanol
masers are associated with sources within infrared dark clouds (IRDC) which are
believed to mark regions where high-mass star formation is in its very early
stages. The presence of class II methanol masers in a significant fraction of
IRDC suggests that high-mass star formation is common in these regions.
Different maser species are thought to trace different evolutionary phases of
the high-mass star formation process. Comparison of the properties of the
GLIMPSE sources associated with class II methanol masers and other maser
species shows interesting trends, consistent with class I methanol masers
tracing a generally earlier evolutionary phase and OH masers tracing a later
evolutionary phase.Comment: 45 pages, 19 figures, accepted for publication in Ap
Acceptability of a mHealth strategy for hypertension management in a low-income and middle-income country setting: A formative qualitative study among patients and healthcare providers
Background Understanding contextual needs and preferences is important for a successful design and effective outcome of a mHealth strategy. Objectives This formative study aimed to explore the perspectives of patients and providers on the acceptability of a mHealth (text message) strategy and elicit preferred features of a mHealth strategy for hypertension management. Design A qualitative study was conducted using in-depth interviews and focus group discussions guided by the technology acceptance model. Setting The study was conducted at primary healthcare facilities and at a tertiary level referral hospital in Kathmandu, Nepal. Participants A total of 61 participants, patients with hypertension (n=41), their family members (n=5), healthcare workers (n=11) and key informants (n=4) were included. We purposively recruited patients with hypertension aged 30–70 who attended the selected healthcare facilities to obtain maximum variation based on their age, sex and literacy. Results The respondents perceived the mHealth strategy to be useful as it would reinforce medication compliance and behaviour change. Participants valued the trustworthiness of information from health authorities that could be delivered privately. Some implementation challenges were identified including a lack of technical manpower, resources for software development, gaps in recording a patient’s essential information and digital illiteracy. Solutions proposed were having system-level preparedness for recording the patient’s details, establishing a separate technical department in the hospital and involving a family member to assist illiterate/ elderly patients. In addition, participants preferred text messages in the local language, containing comprehensive contextual content (disease, treatment, cultural foods and misconceptions) delivered at regular intervals (2–3 times/ week) preferably in the morning or evening. Conclusions We found that a simple text messaging strategy was acceptable for hypertension management in this low/middle-income country setting. However, meticulous planning must address the needs of a diverse range of participants to ensure the mHealth strategy is acceptable to wider groups
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