829 research outputs found

    Philippine municipal fisheries: a review of resources, technology, and socio-economics

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    Small scale fisheries, Sociological aspects, Fishery economics, Fishery management, Philippines,

    Intensified array camera imaging of solid surface combustion aboard the NASA Learjet

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    An intensified array camera was used to image weakly luminous flames spreading over thermally thin paper samples in a low gravity environment aboard the NASA-Lewis Learjet. The aircraft offers 10 to 20 sec of reduced gravity during execution of a Keplerian trajectory and allows the use of instrumentation that is delicate or requires higher electrical power than is available in drop towers. The intensified array camera is a charge intensified device type that responds to light between 400 and 900 nm and has a minimum sensitivity of 10(exp 6) footcandles. The paper sample, either ashless filter paper or a lab wiper, burns inside a sealed chamber which is filled with 21, 18, or 15 pct. oxygen in nitrogen at one atmosphere. The camera views the edge of the paper and its output is recorded on videotape. Flame positions are measured every 0.1 sec to calculate flame spread rates. Comparisons with drop tower data indicate that the flame shapes and spread rates are affected by the residual g level in the aircraft

    Pozzolanic and mechanical properties of Date Palm Seed Ash (Dpsa) concrete

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    This paper presents the findings of a research work conducted on how to improve the mechanical properties of concrete using Date Palm Seed Ash (DPSA) as partial replacement of cement. The DPSA used was obtained by controlled burning of date palm seed in a kiln at a maximum temperature of 630oC for eight hours and air cooled afterwards. The ash obtained was sieved through 75μm sieve and its oxide composition analysed using X-ray fluorescence (XRF) procedures. DoE method of mix design was used to produce concrete ingredients for grade 30N/mm2 giving a water-cement ratio of 0.53. The effect of partial replacement of cement with DPSA on cement paste and concrete using 0, 2.5, 5, 7.5, 10, 15 and 20% DPSA was investigated through consistency and setting times tests, workability test, compressive strength test (at 7, 21, 28 and 56 days curing duration), pozzolanic activity index evaluation and water absorption test. Results show that DPSA has high silicon dioxide (45.50%), aluminum oxide (20.75%) and Iron oxide (7.25%). Findings indicate that the consistency and setting times of cement-DPSA paste increased with increase in the replacement of cement with DPSA. The workability of DPSA concrete decreased with increase in cement replacement. Compressive strength test results show that cement can be replaced with DPSA up to 10% as the compressive strength at 10% replacement is 31.5N/mm2 as against the 31N/mm2 of the normal concrete, at 56 days. The pozzolanic activity index result also show that DPSA concrete meets up the minimum requirement of 75% specified by ASTM C618-15. Also, the water absorption capacity of DPSA concrete at the highest replacement (20%) is 11% less than that at 0%. Keywords: Cement, Compressive strength, Concrete, Date palm seed ash, Partial replacement, Pozzolan

    Modeling Progressive Failure of Bonded Joints Using a Single Joint Finite Element

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90634/1/AIAA-55313-740.pd

    Bidirectional synaptic mechanisms of ocular dominance plasticity in visual cortex

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    As in other mammals with binocular vision, monocular lid suture in mice induces bidirectional plasticity: rapid weakening of responses evoked through the deprived eye followed by delayed strengthening of responses through the open eye. It has been proposed that these bidirectional changes occur through three distinct processes: first, deprived-eye responses rapidly weaken through homosynaptic long-term depression (LTD); second, as the period of deprivation progresses, the modification threshold determining the boundary between synaptic depression and synaptic potentiation becomes lower, favouring potentiation; and third, facilitated by the decreased modification threshold, open-eye responses are strengthened via homosynaptic long-term potentiation (LTP). Of these processes, deprived-eye depression has received the greatest attention, and although several alternative hypotheses are also supported by current research, evidence suggests that α-amino-3- hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor endocytosis through LTD is a key mechanism. The change in modification threshold appears to occur partly through changes in N-methyl-d-aspartate (NMDA) receptor subunit composition, with decreases in the ratio of NR2A to NR2B facilitating potentiation. Although limited research has directly addressed the question of open-eye potentiation, several studies suggest that LTP could account for observed changes in vivo. This review will discuss evidence supporting this three-stage model, along with outstanding issues in the field

    Statistical properties of thermodynamically predicted RNA secondary structures in viral genomes

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    By performing a comprehensive study on 1832 segments of 1212 complete genomes of viruses, we show that in viral genomes the hairpin structures of thermodynamically predicted RNA secondary structures are more abundant than expected under a simple random null hypothesis. The detected hairpin structures of RNA secondary structures are present both in coding and in noncoding regions for the four groups of viruses categorized as dsDNA, dsRNA, ssDNA and ssRNA. For all groups hairpin structures of RNA secondary structures are detected more frequently than expected for a random null hypothesis in noncoding rather than in coding regions. However, potential RNA secondary structures are also present in coding regions of dsDNA group. In fact we detect evolutionary conserved RNA secondary structures in conserved coding and noncoding regions of a large set of complete genomes of dsDNA herpesviruses.Comment: 9 pages, 2 figure

    Analysis of human performance as a measure of mental fatigue

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    In our day to day, we often experience a sense of being tired due to mental or physical workload. Along with that, there is also a feeling of degrading performance, even after the completion of simple tasks. These mental states however, are often not felt consciously or are ignored. This is an attitude that may result in human error, failure, and may lead to potential health problems together with a decrease in quality of life. States of acute mental fatigue may be detected with the close monitoring of certain indicators, such as productivity, performance and health indicators. In this paper, a model and prototype are proposed to detect and monitor acute acute fatigue, based on non-invasive Humancomputer Interaction (HCI). This approach will enable the development of better working environments, with an impact on the quality of life and the work produced.This work was developed in the context of the project CAMCoF - Contextaware Multimodal Communication Framework funded by ERDF - European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT - Funda ção para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project FCOMP-01-0124-FEDER-028980

    Religion and religious education : comparing and contrasting pupils’ and teachers’ views in an English school

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    This publication builds on and develops the English findings of the qualitative study of European teenagers’ perspectives on religion and religious education (Knauth et al. 2008), part of ‘Religion in Education: A contribution to dialogue or a factor of conflict in transforming societies of European countries?’ (REDCo) project. It uses data gathered from 27 pupils, aged 15-16, from a school in a multicultural Northern town in England and compares those findings with data gathered from ten teachers in the humanities faculty of the same school, collected during research for the Warwick REDCo Community of Practice. Comparisons are drawn between the teachers’ and their pupils’ attitudes and values using the same structure as the European study: personal views and experiences of religion, the social dimension of religion, and religious education in school. The discussion offers an analysis of the similarities and differences in worldviews and beliefs which emerged. These include religious commitment/observance differences between the mainly Muslim-heritage pupils and their mainly non-practising Christian-heritage teachers. The research should inform the ways in which the statutory duties to promote community cohesion and equalities can be implemented in schools. It should also facilitate intercultural and interreligious understanding between teachers and the pupils from different ethnic and religious backgrounds

    Global return on investment and cost-effectiveness of WHO's HEAR interventions for hearing loss : a modelling study

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    Background To address the growing prevalence of hearing loss, WHO has identified a compendium of key evidence-based ear and hearing care interventions to be included within countries’ universal health coverage packages. To assess the cost-effectiveness of these interventions and their budgetary effect for countries, we aimed to analyse the investment required to scale up services from baseline to recommended levels, and the return to society for every US1investedinthecompendium.MethodsWedidamodellingstudyusingtheproposedsetofWHOinterventions(summarisedundertheacronymHEAR:hearingscreeningandinterventionfornewbornbabiesandinfants,preschoolandschoolagechildren,olderadults,andadultsathigherriskofhearingloss;eardiseasepreventionandmanagement;accesstotechnologiessuchashearingaids,cochlearimplants,orhearingassistivetechnologies;andrehabilitationserviceprovision),whichspanthelifecourseandincludescreeningandmanagementofhearinglossandrelatedeardiseases,costsandbenefitsforthenationalpopulationcohortsof172countries.Thereturnoninvestmentwasanalysedfortheperiodbetween2020and2030usingthreescenarios:abusinessasusualscenario,aprogressscenariowithascaleupto50FindingsScalingupearandhearingcareinterventionsto901 invested in the compendium. Methods We did a modelling study using the proposed set of WHO interventions (summarised under the acronym HEAR: hearing screening and intervention for newborn babies and infants, pre-school and school-age children, older adults, and adults at higher risk of hearing loss; ear disease prevention and management; access to technologies such as hearing aids, cochlear implants, or hearing assistive technologies; and rehabilitation service provision), which span the life course and include screening and management of hearing loss and related ear diseases, costs and benefits for the national population cohorts of 172 countries. The return on investment was analysed for the period between 2020 and 2030 using three scenarios: a business-as-usual scenario, a progress scenario with a scale-up to 50% of recommended coverage, and an ambitious scenario with scale-up to 90% of recommended coverage. Using data for hearing loss burden from the Global Burden of Disease Study 2019, a transition model with three states (general population, diagnosed, and those who have died) was developed to model the national populations in countries. For the return-on-investment analysis, the monetary value of disability-adjusted life-years (DALYs) averted in addition to productivity gains were compared against the investment required in each scenario. Findings Scaling up ear and hearing care interventions to 90% requires an overall global investment of US238·8 billion over 10 years. Over a 10-year period, this investment promises substantial health gains with more than 130 million DALYs averted. These gains translate to a monetary value of more than US13trillion.Inaddition,investmentinhearingcarewillresultinproductivitybenefitsofmorethanUS1·3 trillion. In addition, investment in hearing care will result in productivity benefits of more than US2 trillion at the global level by 2030. Together, these benefits correspond to a return of nearly US15foreveryUS15 for every US1 invested. Interpretation This is the first-ever global investment case for integrating ear and hearing care interventions in countries’ universal health coverage services. The findings show the economic benefits of investing in this compendium and provide the basis for facilitating the increase of country's health budget for strengthening ear and hearing care services

    Two-species percolation and Scaling theory of the metal-insulator transition in two dimensions

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    Recently, a simple non-interacting-electron model, combining local quantum tunneling via quantum point contacts and global classical percolation, has been introduced in order to describe the observed ``metal-insulator transition'' in two dimensions [1]. Here, based upon that model, a two-species-percolation scaling theory is introduced and compared to the experimental data. The two species in this model are, on one hand, the ``metallic'' point contacts, whose critical energy lies below the Fermi energy, and on the other hand, the insulating quantum point contacts. It is shown that many features of the experiments, such as the exponential dependence of the resistance on temperature on the metallic side, the linear dependence of the exponent on density, the e2/he^2/h scale of the critical resistance, the quenching of the metallic phase by a parallel magnetic field and the non-monotonic dependence of the critical density on a perpendicular magnetic field, can be naturally explained by the model. Moreover, details such as the nonmonotonic dependence of the resistance on temperature or the inflection point of the resistance vs. parallel magnetic are also a natural consequence of the theory. The calculated parallel field dependence of the critical density agrees excellently with experiments, and is used to deduce an experimental value of the confining energy in the vertical direction. It is also shown that the resistance on the ``metallic'' side can decrease with decreasing temperature by an arbitrary factor in the degenerate regime (TEFT\lesssim E_F).Comment: 8 pages, 8 figure
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