2,319 research outputs found
PENGARUH DEBIT ALIRAN TERHADAP SEDIMENTASI DI SUNGAI LEMATANG KABUPATEN LAHAT
Sedimentation that occurred in the Lematang River in Lahat Regency was caused by river bank erosion, construction activities, and household waste brought by the flow discharge. The flow of the Lematang river will certainly affect the amount of sedimentation that will occur in the Lematang river.Based on the test results of the analysis of sediment sample filters, the results obtained d50 = 0.425 mm, and the results of research on the river cross-section with the aim to calculate the volume of base sediment sediment / bed load that occurs by flowing Lematang river flow obtained H = 0.41 m, B = 0 , 41 m, V = 2,650 m / sec.Based on the results of the analysis of the influence of flow discharge on sedimentation in the Lematang River, Lahat Regency, it is known that the type of bed load sediment in the Lematang River is poorly graded sand with large sediment transport carried by the flow discharge in the study segment of 0.022 (m3 / sec) with the duboy's method and 0.0000004 (kg / sec / m) with the shield's method, so the sediment volume for the next one year is 693,792 (m3 / sec) m for the duboy's method and 126,144 (kg / sec / m) for the shield's method
Community knowledge and acceptance of larviciding for malaria control in a rural district of east-central Tanzania
The use of microbial larvicides, a form of larval source management, is a less commonly used malaria control intervention that nonetheless has significant potential as a component of an integrated vector management strategy. We evaluated community acceptability of larviciding in a rural district in east-central Tanzania using data from 962 household surveys, 12 focus group discussions, and 24 in-depth interviews. Most survey respondents trusted in the safety (73.1%) and efficacy of larviciding, both with regards to mosquito control (92.3%) and to reduce malaria infection risk (91.9%). Probing these perceptions using a Likert scale provides a more detailed picture. Focus group participants and key informants were also receptive to larviciding, but stressed the importance of sensitization before its implementation. Overall, 73.4% of survey respondents expressed a willingness to make a nominal household contribution to a larviciding program, a proportion which decreased as the proposed contribution increased. The lower-bound mean willingness to pay is estimated at 2,934 Tanzanian Shillings (approximately US$1.76) per three month period. We present a multivariate probit regression analysis examining factors associated with willingness to pay. Overall, our findings point to a receptive environment in a rural setting in Tanzania for the use of microbial larvicides in malaria control. © 2014 by the authors; licensee MDPI, Basel, Switzerland
Synthesis of ambergris odorant ent-ambrox
A synthesis of the ambergris odorant ent-ambrox starting from (-)-ozic acid is described.1031432
Non-equilibrium Condensation Process in a Holographic Superconductor
We study the non-equilibrium condensation process in a holographic
superconductor. When the temperature T is smaller than a critical temperature
T_c, there are two black hole solutions, the Reissner-Nordstrom-AdS black hole
and a black hole with a scalar hair. In the boundary theory, they can be
regarded as the supercooled normal phase and the superconducting phase,
respectively. We consider perturbations on supercooled Reissner-Nordstrom-AdS
black holes and study their non-linear time evolution to know about physical
phenomena associated with rapidly-cooled superconductors. We find that, for
T<T_c, the initial perturbations grow exponentially and, eventually, spacetimes
approach the hairy black holes. We also clarify how the relaxation process from
a far-from-equilibrium state proceeds in the boundary theory by observing the
time dependence of the superconducting order parameter. Finally, we study the
time evolution of event and apparent horizons and discuss their correspondence
with the entropy of the boundary theory. Our result gives a first step toward
the holographic understanding of the non-equilibrium process in
superconductors.Comment: 20 pages, 7 figure
The information needs of people living with ankylosing spondylitis: a questionnaire survey
<p>BACKGROUND:Today, health care is patient-centred with patients more involved in medical decision making and taking an active role in managing their disease. It is important that patients are appropriately informed about their condition and that their health care needs are met. We examine the information utilisation, sources and needs of people with ankylosing spondylitis (AS).</p>
<p>METHODS: Participants in an existing AS cohort study were asked to complete a postal or online questionnaire containing closed and open-ended questions, regarding their information access and needs. Participants were stratified by age and descriptive statistics were performed using STATA 11, while thematic analysis was performed on open-ended question narratives. Qualitative data was handled in Microsoft Access and explored for emerging themes and patterns of experiences.</p>
<p>RESULTS: Despite 73% of respondents having internet access, only 49% used the internet to access information regarding AS. Even then, this was only infrequently. Only 50% of respondents reported accessing written information about AS, which was obtained mainly in specialist clinics. Women were more likely than men to access information (63% (women) 46% (men)) regardless of the source, while younger patients were more likely to use online sources. The main source of non-written information was the rheumatologist. Overall, the respondents felt there was sufficient information available, but there was a perception that the tone was often too negative. The majority (95%) of people would like to receive a regular newsletter about AS, containing positive practical and local information. Suggestions were also made for more information about AS to be made available to non-specialist medical professionals and the general public.</p>
<p>CONCLUSIONS: There appears to be sufficient information available for people with AS in the UK and this is mostly accessed by younger AS patients. Many patients, particularly men, choose not to access AS information and concerns were raised about its negative tone. Patients still rely on written and verbal information from their specialists. Future initiatives should focus on the delivery of more positive information, targeting younger participants in particular and increasing the awareness in the general population and wider non-specialist medical community.</p>
A magnetically collimated jet from an evolved star
Planetary nebulae often have asymmetric shapes, which could arise due to
collimated jets from evolved stars before evolution to the planetary nebula
phase. The source of jet collimation in these stars is unknown. Magnetic fields
are thought to collimate outflows that are observed in many other astrophysical
sources, such as active galactic nuclei and proto-stars, although hitherto
there are no direct observations of both the magnetic field direction and
strength in any collimated jet. Theoretical models have shown that magnetic
fields could also be the dominant source of collimation of jet in evolved
stars. Here we report measurements of the polarization of water vapour masers
that trace the precessing jet emanating from the asymptotic giant branch star
W43A at 2.6 kpc from the Sun, which is undergoing rapid evolution into a
planetary nebula. The masers occur in two clusters at opposing tips of the
jets, ~1,000 AU from the star. We find direct evidence that the magnetic field
is collimating the jet.Comment: Published in Nature 440 (March 2nd 2006). High-res figures can be
found at http://www.jb.man.ac.uk/~wouter/papers/w43a/w43a.htm
Single-atom imaging of fermions in a quantum-gas microscope
Single-atom-resolved detection in optical lattices using quantum-gas
microscopes has enabled a new generation of experiments in the field of quantum
simulation. Fluorescence imaging of individual atoms has so far been achieved
for bosonic species with optical molasses cooling, whereas detection of
fermionic alkaline atoms in optical lattices by this method has proven more
challenging. Here we demonstrate single-site- and single-atom-resolved
fluorescence imaging of fermionic potassium-40 atoms in a quantum-gas
microscope setup using electromagnetically-induced-transparency cooling. We
detected on average 1000 fluorescence photons from a single atom within 1.5s,
while keeping it close to the vibrational ground state of the optical lattice.
Our results will enable the study of strongly correlated fermionic quantum
systems in optical lattices with resolution at the single-atom level, and give
access to observables such as the local entropy distribution and individual
defects in fermionic Mott insulators or anti-ferromagnetically ordered phases.Comment: 7 pages, 5 figures; Nature Physics, published online 13 July 201
Association between Household Air Pollution Exposure and Chronic Obstructive Pulmonary Disease Outcomes in 13 Low- and Middle-Income Country Settings.
RATIONALE: Forty percent of households worldwide burn biomass fuels for energy, which may be the most important contributor to household air pollution. OBJECTIVES: To examine the association between household air pollution exposure and chronic obstructive pulmonary disease (COPD) outcomes in 13 resource-poor settings. METHODS: We analyzed data from 12,396 adult participants living in 13 resource-poor, population-based settings. Household air pollution exposure was defined as using biomass materials as the primary fuel source in the home. We used multivariable regressions to assess the relationship between household air pollution exposure and COPD outcomes, evaluated for interactions, and conducted sensitivity analyses to test the robustness of our findings. MEASUREMENTS AND MAIN RESULTS: Average age was 54.9 years (44.2-59.6 yr across settings), 48.5% were women (38.3-54.5%), prevalence of household air pollution exposure was 38% (0.5-99.6%), and 8.8% (1.7-15.5%) had COPD. Participants with household air pollution exposure were 41% more likely to have COPD (adjusted odds ratio, 1.41; 95% confidence interval, 1.18-1.68) than those without the exposure, and 13.5% (6.4-20.6%) of COPD prevalence may be caused by household air pollution exposure, compared with 12.4% caused by cigarette smoking. The association between household air pollution exposure and COPD was stronger in women (1.70; 1.24-2.32) than in men (1.21; 0.92-1.58). CONCLUSIONS: Household air pollution exposure was associated with a higher prevalence of COPD, particularly among women, and it is likely a leading population-attributable risk factor for COPD in resource-poor settings
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