2,579 research outputs found

    Determinants of Alcohol, Khat, and Bhang Use in Rural Kenya

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    The study investigated local determinants of substance use in rural Kenya. Over the years, there has been a growing concern over increased use of substances across ages, gender, religious persuasions, and social class in Kenya. It is still unclear what psychosocial individual and/or community factors might be that offer some explanation for the high levels of alcohol and drug use. The study investigated community members’ social status in areas of gender, education, employment, self–esteem, and availability of substances. The sample was comprised of Kenyan rural participants, and included 153 men and 64 women with a mean age of 34.2 years. The participants completed a survey measuring possible psychosocial determinants of alcohol, khat and bhang (i.e., marijuana) use patterns. The sample evidenced high levels of substance use particularly involving the locally available substances (i.e., bottled beer, local brews, chewing khat, smoking bhang). Males in comparison to females were more likely to drink alcohol, chew khat, and smoke bhang. Women compared to men reported higher education and employment status, which were associated with less substance use. Females had higher self-esteem when they did not use bottled beer whereas males had higher self-esteem when they use bottled beer. The implications of these findings are discussed.Keywords: psychosocial determinants, substance use, rural, age, gender, social clas

    Fish oil (n-3 fatty acids) in drug resistant epilepsy: a randomised placebo-controlled crossover study.

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    Backgroundn-3 fatty acids inhibit neuronal excitability and reduce seizures in animal models. High-dose fish oil has been explored in two randomised trials in drug resistant epilepsy with negative results. We performed a phase II randomised controlled crossover trial of low-dose and high-dose fish oil in participants with drug resistant epilepsy to explore whether low-dose or high-dose fish oil reduces seizures or improves cardiovascular health.MethodsRandomised placebo-controlled trial of low-dose and high-dose fish oil versus placebo (corn oil, linoleic acid) in 24 participants with drug resistant epilepsy. A three-period crossover design was utilised lasting 42 weeks, with three 10-week treatment periods and two 6-week washout periods. All participants were randomised in double-blind fashion to receive placebo, high dose or low dose in different sequences. The primary outcome was per cent change in total seizure frequency.FindingsLow-dose fish oil (3 capsules/day, 1080 mg eicosapentaenoic acid+docosahexaenoic acid) was associated with a 33.6% reduction in seizure frequency compared with placebo. Low-dose fish oil was also associated with a mild but significant reduction in blood pressure. High-dose fish oil was no different than placebo in reducing seizures or improving cardiac risk factors.InterpretationIn this phase II randomised crossover trial, low-dose fish oil was effective in reducing seizures compared with placebo. The magnitude of improvement is similar to that of recent antiepileptic drug trials in drug resistant epilepsy (DRE). The results indicate that low-dose fish oil may reduce seizures and improve the health of people with epilepsy. These findings justify a large multicentre randomised trial of low-dose fish oil (n-3 fatty acids <1080 mg/day) in drug resistant epilepsy.Trial registration numberNCT00871377

    Formation and emplacement of the Josephine ophiolite and the Nevadan orogeny in the Klamath Mountains, California-Oregon: U/Pb zircon and ^(40)Ar/^(39)Ar geochronology

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    Cordilleran ophiolites typically occur as basement for accreted terranes. In the Klamath Mountains, ophiolitic terranes were progressively accreted by underthrusting beneath North America. The Josephine ophiolite is the youngest of the Klamath ophiolites and forms the basement for a thick Late Jurassic flysch sequence (Galice Formation). This ophiolite-flysch terrane forms an east dipping thrust sheet sandwiched between older rocks of the Klamath Mountains above and a coeval plutonic-volcanic arc complex below. The outcrop pattern of the roof (Orleans) thrust indicates a minimum displacement of 40 km, and geophysical studies suggest >110 km of displacement. The basal (Madstone Cabin) thrust is associated with an amphibolitic sole and has a minimum displacement of 12 km. A rapid sequence of events, from ophiolite generation to thrust emplacement, has been determined using ^(40)Ar/^(39)Ar and Pb/U geochronology. Ophiolite generation occurred at 162–164 Ma, a thin hemipelagic sequence was deposited from 162 to 157 Ma, and flysch deposition took place between 157 and 150 Ma. Tight age constraints on thrusting and low-grade metamorphism associated with ophiolite emplacement (Nevadan orogeny) are provided by abundant calc-alkaline dikes and plutons ranging in age from 151 to 139 Ma. Deformation and metamorphism related to the Nevadan orogeny appears to have extended from ∌155 to 135 Ma. Most of the crustal shortening took place by thrusting, constrained to have occurred from ∌155 to 150 Ma on both the roof and basal thrusts. Minimum rates of displacement are 2.4 and 3.6 mm/year for the basal and roof thrusts, respectively, but correlations with coeval thrusts yield rates of 8.4 and 22 mm/year (within the range of plate velocities). The high displacement rates and synchronous movement along the basal and roof thrusts suggest that the ophiolite may have behaved as a microplate situated between western North America and an active arc from ∌155 to 150 Ma. A steep thermal gradient was present in the Josephine-Galice thrust sheet from ∌155 to 150 Ma, with amphibolite facies conditions developed along the basal thrust. After accretion of the ophiolite by underthrusting, the ophiolite and overlying flysch underwent low-grade dynamothermal regional metamorphism from 150 to 135 Ma. The upper age limit is tightly constrained by a 135 Ma K-feldspar cooling age, syntectonic plutons as young as 139 Ma, and a Lower Cretaceous angular unconformity. Very rapid exhumation is indicated by the late Valanginian to Hauterivian age (∌130 Ma) of the unconformably overlying strata, suggesting unroofing by extensional tectonics

    Time relations and structural-stratigraphic patterns in ophiolite accretion, west central Klamath Mountains, California

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    New geochronological data and published structural and stratigraphic data show that two distinctly different ophiolitic assemblages formed in general proximity to one another at nearly the same time and were subsequently imbricated along a regional thrust zone. The Josephine ophiolite constitutes a complete oceanic crust and upper mantle sequence which lies within the western Jurassic belt of the Klamath province. Within the study area the Josephine ophiolite was formed by seafloor spreading at about 157 m.y. before present. It was immediately covered by a thin pelagic and hemipelagic sequence which grades into a thick flysch sequence, both of which comprise the Galice Formation. The Galice flysch was derived from volcanic arc and uplifted continental margin orogenic assemblages. A major nonvolcanic source for the Galice flysch appears to have been the western Paleozoic and Triassic belt of the Klamath province exposed to the east. Proximal volcanic arc activity migrated to the site of the Josephine-Galice section by 151 m.y. and is represented by numerous dikes and sills which intrude the ophiolite and Galice Formation. The Preston Peak ophiolite is a polygenetic assemblage consisting of (1) a pre-mid-Jurassic tectonitic peridotite-amphibolite substrate which represents disrupted and unroofed basement of the western Paleozoic and Triassic belt and (2) an upper mafic complex which was intruded through and constructed above the tectonite substrate at about 160 m.y. The mafic complex consists primarily of diabase hypabyssal rocks that are overlain by diabase-clast breccia and hemipelagic deposits. A major arc-plutonic complex was emplaced into the Preston Peak ophiolite in at least two pulses at 153 and 149 m.y. Major phases of this complex consist of wehrlite, gabbro, pyroxene diorite, and hornblende diorite. The Josephine ophiolite is interpreted as the remnants of interarc basin crust. The Preston Peak ophiolite is interpreted as either a primitive remnant arc complex or a rift edge facies for the Josephine interarc basin. The Galice Formation represents a submarine fan complex that was built on juvenile crust of the Josephine basin floor. During the time interval of 153 to 149 m.y. the locus or arc magmatism migrated to an area which included the interarc basin floor and the remnant arc or basin edge. The basin shortly thereafter closed by convergent tectonics during the Nevadan orogeny resulting in the imbrication of the Josephine and Preston Peak ophiolites and their superimposed arc assemblages. The transition from seafloor spreading generation of Josephine ophiolite to its tectonic accretion by convergence and basin closure occurred within 5 to 10 m.y. The process of rifting and ophiolite formation in series with convergence and ophiolite accretion is considered an important mechanism for generating and displacing allocthonous terranes in the Klamath Mountains-Sierra Nevada region, and perhaps throughout the western cordillera

    Scalable, biofunctional, ultra-stable nano- bio- composite materials containing living cells

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    Three-dimensional encapsulation of cells within nanostructured silica gels or matrices enables applications as diverse as biosensors, microbial fuel cells, artificial organs, and vaccines. It also allows study of individual cell behaviors. Recent progress has improved the performance and flexibility of cellular encapsulation, yet there remains a need for robust scalable processes for large format production of cell-encapsulating materials. Here, we detail two novel techniques, that enable the large-scale production of functional Nano-Bio-Composites (NBCs) containing living cells within ordered 3-D lipid/silica nanostructures: 1) thick-casting and 2) spray drying. Furthermore, we detail a third technique for material scaling in which aqueous, silicate-based gel monoliths encapsulate biofunctional yeast or bacteria. Both dry processes are demonstrated to work with multiple cell types and result in dry powders exhibiting a unique combination of properties including: highly ordered 3-D nanostructure, extended lipid fluidity, tunable macro-morphologies and aerodynamic diameters, and unexpectedly high physical strength. Nanoindentation of the encasing nanostructure revealed Young’s modulus and hardness of 13 and 1.4 GPa respectively, which was unexpected considering the low processing conditions. We hypothesized and confirmed that NBC-encapsulated cells would remain viable for extended periods of time under elevated aging conditions. We attribute this due to the high material strength as observed with nanoindentation, which would prevent cell growth and force bacteria into viable but not culturable (VBNC) states. In concordance with the VBNC state, cellular ATP levels remained elevated even over eight months confirming temperature stable, viable cells. However, their ability to undergo resuscitation and enter growth phase greatly decreased with time in the VBNC state. A quantitative method of determining resuscitation frequencies was developed and showed that, after 36 weeks in an NBC-induced VBNC state, less than 1 in 10,000 cells underwent resuscitation. We verify the VBNC phenotype in gel-encapsulated cells by studying cellular RNA expression levels. These latent behaviors are further demonstrated with an in-vivo immunological study in which mice, immunized with NBCs containing the vaccine Bacillus Calmette-GuĂ©rin, were observed to be immunized against a latent form of Tuberculosis. This finding is, in our understanding, the first demonstration of a latent disease-specific live cell immunotherapy. The NBC platform production of industrially scalable quantities of VBNC cells is of interest for research in bacterial persistence and screening of drugs targeting such cells. NBC’s may also enable long-term preservation of living cells for applications in cell-based sensing and the packaging and delivery of live-cell vaccines. Moreover, our methodology represents a novel process for preparing formulations of latent cells in-silico, which could find application in basic cellular research and for the development of a latent-specific vaccine

    Perspectives on e-books and digital textbooks and the way ahead

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    This article presents a range of perspectives on current issues around e-book and textbook supply and consumption in libraries and universities. It is an attempt to provide an analysis of the often-contentious issues arising and also offers an insight into the positions of all the various parties involved. Whilst there might not be agreement or consensus on the causes of issues and the way to proceed, the article attempts to coalesce various perspectives, in the hope of achieving a greater understanding of different stakeholders. Much of the debate in recent years has focused on the situation in the United Kingdom, but similar issues exist in many other countries and an insight into the international perspective is provided. We also offer some commentary on ways forward for both the short and longer term

    Harper, D.J., Hobbs, S.J. & Moore, J. (2011). The ten to five repeated jump test: A new test for evaluation of lower body reactive strength. BASES 2011 Annual Student Conference. Integrations and Innovations: An Interdisciplinary Approach to Sport and Exercise Science. 2011 April 12-13; Chester, United Kingdom. Chester,: The University of Chester; 2011.

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    Reactive strength is generating sharp interest with research and applied practitioners as a measure to monitor an individual’s ability to change quickly (<0.25s) from an eccentric to a concentric contraction (Young, 1995: New Stud Athletics, 10, 88-96). In order to further replicate the rebound qualities exhibited in many sporting activities Lloyd et al. (2009: Journal of Sports Sciences, 27, 1565-1573) used a maximal bi-lateral hopping test performed over five repeated repetitions. However, the ability of this test to detect training induced changes in performance was poor. Analysis of covariance (CV) for the average height obtained was 15%. The authors acknowledged that this greater variability was likely due to difficulties in postural control. The purpose of this study therefore was to refine and develop a methodology for assessment of lower body reactive strength, examine it for test-retest reliability, determine the internal consistency of the test across five trials and, in addition, validate measures using contact mat against those acquired from ground-fixed force plate measures. Sixteen male Super League rugby league players (age, 19.7 + 0.8 years; body mass 88.5 + 12.0 kg; height 177.3 + 6.1m; mean + s) volunteered to participate in the reliability study. An additional group of seven male college academy level rugby league players (age 17.4 + 0.6 years; body mass 81.6 + 16.3 kg) participated in the internal consistency and validity study. All jumps were performed on a mobile contact mat (Smart-jump, Fusion Sport, Australia) with instantaneous feedback on contact time (CT), flight time (FT), peak power output (PPO), impulse (IMP) and the reactive strength index (RSI) collected and displayed via a hand-held PDA (iPAQ, Hewlett Packard, USA). For the validity and internal consistency study the mobile contact mat was positioned directly over a 400 x 600 mm ground-fixed force plate sampling at 500 Hz (Kistler Instruments Ltd., Alton, Hampshire, UK; Model 9281CA). The ten to five repeated jump test (RJT) involved participants performing optimal vertical rebounds (i.e. maximal elevation at each jump) with minimal ground contact (<0.25s) performed for a series of eleven jumps. Participants were instructed to keep their hands on the hips to ensure no contribution from the arms. Further instructions were given to (a) “minimize ground contact time”, (b) “maximize jump height”, (c) “imagine the ground as a hot surface”, and (d) “legs like a stiff spring” (Flanaghan & Comyns, 2008, Strength and Conditioning Journal, 30, 32-38). From the eleven jumps that were recorded the first jump was discarded from the analysis since this did not involve a fast stretch-shortening cycle. From the remaining ten jumps the five jumps with greatest height exhibiting ground contact of less than 0.25s were used for further analysed. The height of these five jumps was then added together to provide a repeated reactive strength score. For the validity study participants performed five trials and for the reliability study two trials were performed on each testing session which were separated by one week. All participants in both studies were given a minimum of one minutes rest between successive trials. Pearson’s correlation coefficient revealed a significant (r=0.897; P=<0.01) level of agreement between the mobile contact mat and force plate for ground contact time. There was a 14.25% change in the mean height from trial 1 to trial 5, however after an 11.55% change between trial 1 and 2 the change between trial 2 to 5 varied from only 0.33 to 1.25%. The average CV across all seven participants in the validity study was 9%. The test-retest reliability results displayed a significant (r=0.782; P=<0.01) relationship between trial 1 and 2. The main finding of the present study was that the CV of the ten to five RJT was found to be 9%. The higher levels of sensitivity in the present protocol compared to Lloyd et al. (2009) can be attributed to the elimination of the lowest 5 jump heights that are likely to have been a result of deficiencies in postural control. Another important finding was that the ten to five RJT was found to gain consistent scores after just 2 trials. Furthermore, the mobile contact mat used in the present study was shown to have a high level of criterion validity in agreement with Lloyd et al. (2009). Consequently, for coaches working with large groups of athletes the ten to five RJT can provide a quick and reliable means of monitoring individual progress and evaluating the success of interventions aimed at developing the reactive strength capabilities of their athletes

    Fabrication of low-cost, large-area prototype Si(Li) detectors for the GAPS experiment

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    A Si(Li) detector fabrication procedure has been developed with the aim of satisfying the unique requirements of the GAPS (General Antiparticle Spectrometer) experiment. Si(Li) detectors are particularly well-suited to the GAPS detection scheme, in which several planes of detectors act as the target to slow and capture an incoming antiparticle into an exotic atom, as well as the spectrometer and tracker to measure the resulting decay X-rays and annihilation products. These detectors must provide the absorption depth, energy resolution, tracking efficiency, and active area necessary for this technique, all within the significant temperature, power, and cost constraints of an Antarctic long-duration balloon flight. We report here on the fabrication and performance of prototype 2"-diameter, 1-1.25 mm-thick, single-strip Si(Li) detectors that provide the necessary X-ray energy resolution of ∌\sim4 keV for a cost per unit area that is far below that of previously-acquired commercial detectors. This fabrication procedure is currently being optimized for the 4"-diameter, 2.5 mm-thick, multi-strip geometry that will be used for the GAPS flight detectors.Comment: Accepted for publication at Nuclear Instrumentation and Methods A, 12 pages, 11 figure
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