199 research outputs found

    An Integrated Approach for Future RAN Architecture

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    A question of continuing control -balancing building quality of housing and building codes

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    The Building Code of Australia seeks to establish &ldquo;nationally consistent, minimum necessary standards of relevant, health, safety (including structural safety and safety from fire), amenity and sustainability objectives efficiently&rdquo;. These goals are laudable &ndash; but where are the goals of quality and maintenance, which are also an essential part of achieving adequate and continuing health and safety for the built environment? Defects such as dampness, settlement and cracking, staining, wood rot, termite damage, rusting, and roof leakage are common enough to suggest that there are still issues with building quality in housing. They are caused by a combination of initial poor workmanship and poor quality materials and latterly by poorly executed or inadequate maintenance. Local architecture, developed over many years of trial and error, produce buildings linked to their climate and local materials (think of the typical &ldquo;Queenslander&rdquo; house). Today&rsquo;s architecture imports technologies and materials from many differing countries and climates &ndash; that are not necessarily suitable for the location, nor is there necessarily the same quality control over the material quality and production. Inappropriate use and inadequate understanding of new materials and techniques can lead to the generation of further defects.Whilst the building code contains provisions for initial-build material quality and workmanship, there is no continuing control over a house over its life span. Reliance is placed on advertising the need, for example, to employ qualified tradespeople; replace batteries in smoke detectors; and other good advice to help maintain housing to a minimum standard. Is this sufficient?Mechanisms to make the transfer of knowledge to those who need to use it &ndash; be it the workforce or the houseowner &ndash; need to be improved. Should the building code be more visual and accessible in it&rsquo;s content? Should the building code include provisions for maintenance? Should the building code require every house to have a &ldquo;users manual&rdquo; &ndash; much like a car? An extensive review of literature identifies the scale of the problem of poor quality housing and highlights some suggested causes &ndash; inadequate knowledge of the BCA by general housebuilders being one. However little work has been done to investigate what could be done to improve the situation. This work suggests that improvements to knowledge transfer would improve the quality of housing and a model of the knowledge transfer process is proposed, identifying those areas where the knowledge flows need to occur that would impact both the builders and users of housing.<br /

    Analisis arus-voltan bagi pengubahsuaian proses fabrikasi sel suria silikon jenis-p ke atas wafer silikon jenis-n

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    Sel suria adalah peranti semikonduktor yang menukar tenaga matahari kepada tenaga elektrik. Sel suria generasi pertama terdiri dari sel suria silikon (Si). Pada masa ini, hampir 90% daripada pasaran pengeluaran fotovolta (PV) adalah berdasarkan wafer Si. Ini disebabkan oleh kecekapan dan ketahanan yang tinggi serta jangka hayat yang lama iaitu selama 30 tahun. Proses pemfabrikasian piawai bagi sel suria Si dimulakan dengan proses pencucian dan penteksturan wafer Si, difusi Fosforus untuk pembentukan pemancar, pembentukan elektrod atas dan bawah melalui proses cetakan skrin dan proses pembakaran yang melengkapkan fabrikasi sel suria. Dalam industri, proses piawai ini dilakukan pada wafer Si jenis-p. Wafer jenis-n pula mempunyai potensi yang tinggi untuk menghasilkan sel suria Si yang berkecekapan tinggi. Namun, proses untuk menghasilkan sel suria silikon atas Si wafer jenis-n melalui proses yang lebih rumit dan lama seperti dua peringkat proses difusi menjadikan wafer jenis-p digunakan secara meluas kerana dapat merendahkan kos pemfabrikasian. Dalam penyelidikan ini, analisis bagi arus-voltan bagi sel suria Si jenis-n yang difabrikasi menggunakan adaptasi proses fabrikasi piawai bagi wafer Si jenis-p akan dibincangkan. Daripada kajian simulasi menggunakan perisian PC1D, didapati bahawa kecekapan bagi sel suria jenis-p dan jenis-n yang difabrikasi dengan kaedah yang sama adalah 19.63% dan 20.16%. Manakala keputusan eksperimen menunjukkan kecekapan sebanyak 9.44% dan 5.51% bagi sel suria jenis-p dan jenis-n

    Genome-Wide Studies Reveal that H3K4me3 Modification in Bivalent Genes Is Dynamically Regulated during the Pluripotent Cell Cycle and Stabilized upon Differentiation

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    Indexación: Web of Science; Scopus.Stem cell phenotypes are reflected by posttranslational histone modifications, and this chromatin-related memory must be mitotically inherited to maintain cell identity through proliferative expansion. In human embryonic stem cells (hESCs), bivalent genes with both activating (H3K4me3) and repressive (H3K27me3) histone modifications are essential to sustain pluripotency. Yet, the molecular mechanisms by which this epigenetic landscape is transferred to progeny cells remain to be established. By mapping genomic enrichment of H3K4me3/H3K27me3 in pure populations of hESCs in G2, mitotic, and G1 phases of the cell cycle, we found striking variations in the levels of H3K4me3 through the G2-M-G1 transition. Analysis of a representative set of bivalent genes revealed that chromatin modifiers involved in H3K4 methylation/demethylation are recruited to bivalent gene promoters in a cell cycle-dependent fashion. Interestingly, bivalent genes enriched with H3K4me3 exclusively during mitosis undergo the strongest upregulation after induction of differentiation. Furthermore, the histone modification signature of genes that remain bivalent in differentiated cells resolves into a cell cycle-independent pattern after lineage commitment. These results establish a new dimension of chromatin regulation important in the maintenance of pluripotencyhttp://mcb.asm.org/content/36/4/61

    Adaptation of Left Ventricular Twist Mechanics in Exercise-Trained Children Is Only Evident after the Adolescent Growth Spurt.

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    The extent of structural cardiac remodeling in response to endurance training is maturity dependent. In adults, this structural adaptation is often associated with the adaptation of left ventricular (LV) twist mechanics. For example, an increase in LV twist often follows an expansion in end-diastolic volume, whereas a reduction in twist may follow a thickening of the LV walls. While structural cardiac remodeling has been shown to be more prominent post-peak height velocity (PHV), it remains to be determined how this maturation-dependent structural remodeling influences LV twist. Therefore, we aimed to (1) compare LV twist mechanics between trained and untrained children pre- and post-PHV and (2) investigate how LV structural variables relate to LV twist mechanics pre- and post-PHV. Left ventricular function and morphology were assessed (echocardiography) in endurance-trained and untrained boys (n = 38 and n = 28, respectively) and girls (n = 39 and n = 34, respectively). Participants were categorized as either pre- or post-PHV using maturity offset to estimate somatic maturation. Pre-PHV, there were no differences in LV twist or torsion between trained and untrained boys (twist: P = .630; torsion: P = .382) or girls (twist: P = .502; torsion: P = .316), and LV twist mechanics were not related with any LV structural variables (P &gt; .05). Post-PHV, LV twist was lower in trained versus untrained boys (P = .004), with torsion lower in trained groups, irrespective of sex (boys: P &lt; .001; girls: P = .017). Moreover, LV torsion was inversely related to LV mass (boys: r = -0.55, P = .001; girls: r = -0.46, P = .003) and end-diastolic volume (boys: r = -0.64, P &lt; .001; girls: r = -0.36, P = .025) in both sexes. A difference in LV twist mechanics between endurance-trained and untrained cohorts is only apparent post-PHV, where structural and functional remodeling were related

    Molecular Characterization of the 16S rRNA Gene of Phytoplasmas Detected in Two Leafhopper Species Associated with Alfalfa Plants Infected with Witches' Broom in Oman

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    Two leafhopper species, Austroagallia avicula and Empoasca sp., were consistently found in alfalfa fields infected with witches’ broom phytoplasma (OmanAlfWB) in the Al-Batinah, Dakhliya, North and South Sharqiya, Muscat, and Al-Bureimi regions of the Sultanate of Oman. Phytoplasmas from both leafhoppers were detected by specific polymerase chain reaction (PCR) amplification of the 16S rRNA gene and the spacer region in direct PCR using P1/P7 primer pairs. Comparative RFLP profiles of the amplified rRNA gene and the spacer region from leafhopper phytoplasmas and from 20 phytoplasma controls yielded patterns referable to phytoplasmas belonging to the peanut witches’ broom group (16SrII group). In particular, extensive RFLP analyses with the endonucleases HpaII, Tru9I, Tsp509I, and RsaI indicated that the phytoplasmas in A. avicula and Empoasca sp. were identical but showed some differences from OmanAlfWB; however, RFLP patterns obtained with TaqI showed the OmanAlfWB and the phytoplasmas from the two leafhoppers to be identical. Direct PCR products amplified from phytoplasma leafhopper DNA using the P1/P7 primer pair were cloned and sequenced yielding 1758 bp and 1755 bp products from A. avicula and Empoasca sp. respectively; the homology of these sequences with OmanAlfWB and papaya yellow crinkle phytoplasmas was more than 98%. A phylogenetic tree based on the 16S rRNA gene and spacer region sequences from 44 phytoplasmas revealed that the phytoplasmas from the leafhoppers clustered with OmanAlfWB, papaya yellow crinkle, and gerbera phyllody phytoplasmas, all belonging to 16SrII group, but were distinct from lime witches’ broom phytoplasma, the most commonly found phytoplasma in the Sultanate of Oman

    The Typhoid Vaccine Acceleration Consortium (TyVAC): Vaccine effectiveness study designs: Accelerating the introduction of typhoid conjugate vaccines and reducing the global burden of enteric fever. Report from a meeting held on 26-27 October 2016, Oxford, UK

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    Typhoid fever is estimated to cause between 11.9–26.9 million infections globally each year with 129,000–216,510 deaths. Access to improved water sources have reduced disease incidence in parts of the world but the use of efficacious vaccines is seen as an important public health tool for countries with a high disease burden. A new generation of Vi typhoid conjugate vaccines (TCVs), licensed for use in young children and expected to provide longer lasting protection than previous vaccines, are now available. The WHO Strategic Advisory Group of Experts on Immunization (SAGE) has convened a working group to review the evidence on TCVs and produce an updated WHO position paper for all typhoid vaccines in 2018 that will inform Gavi, the Vaccine Alliance's future vaccine investment strategies for TCVs. The Typhoid Vaccine Acceleration Consortium (TyVAC) has been formed through a $36.9 million funding program from the Bill & Melinda Gates Foundation to accelerate the introduction of TCVs into Gavi-eligible countries. In October 2016, a meeting was held to initiate planning of TCV effectiveness studies that will provide the data required by policy makers and stakeholders to support decisions on TCV use in countries with a high typhoid burden. Discussion topics included (1) the latest evidence and data gaps in typhoid epidemiology; (2) WHO and Gavi methods and data requirements; (3) data on TCV efficacy; (4) cost effectiveness analysis for TCVs from mathematical models; (5) TCV delivery and effectiveness study design. Specifically, participants were asked to comment on study design in 3 sites for which population-based typhoid surveillance is underway. The conclusion of the meeting was that country-level decision making would best be informed by the respective selected sites in Africa and Asia vaccinating children aged from 9-months to 15-years-old, employing either an individual or cluster randomized design with design influenced by population characteristics, transmission dynamics, and statistical considerations

    International Society of Nephrology Global Kidney Health Atlas: structures, organization, and services for the management of kidney failure in the Middle East

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    Kidney failure is the permanent impairment of kidney function associated with increased morbidity, hospitalization, and requirement for kidney replacement therapy. A total of 11 countries in the Middle East region (84.6) responded to the survey. The prevalence of chronic kidney disease in the region ranged from 5.2 to 10.6, whereas prevalence of treated kidney failure ranged from 152 to 826 per million population. Overall, the incidence of kidney transplantation was highest in Iran (30.9 per million population) and lowest in Oman and the United Arab Emirates (2.2 and 3.0 per million population, respectively). Long-term hemodialysis services were available in all countries, long-term peritoneal dialysis services were available in 9 (69.2) countries, and transplantation services were available in most countries of the region. Public funding covered the costs of nondialysis chronic kidney disease care in two-thirds of countries, and kidney replacement therapy in nearly all countries. More than half of the countries had dialysis registries; however, national noncommunicable disease strategies were lacking in most countries. The Middle East is a region with high burden of kidney disease and needs cost-effective measures through effective health care funding to be available to improve kidney care in the region. Furthermore, well-designed and sustainable health information systems are needed in the region to address current gaps in kidney care in the region. © 2021 International Society of Nephrolog

    Classification of early tuberculosis states to guide research for improved care and prevention: an international Delphi consensus exercise

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    The current active–latent paradigm of tuberculosis largely neglects the documented spectrum of disease. Inconsistency with regard to definitions, terminology, and diagnostic criteria for different tuberculosis states has limited the progress in research and product development that are needed to achieve tuberculosis elimination. We aimed to develop a new framework of classification for tuberculosis that accommodates key disease states but is sufficiently simple to support pragmatic research and implementation. Through an international Delphi exercise that involved 71 participants representing a wide range of disciplines, sectors, income settings, and geographies, consensus was reached on a set of conceptual states, related terminology, and research gaps. The International Consensus for Early TB (ICE-TB) framework distinguishes disease from infection by the presence of macroscopic pathology and defines two subclinical and two clinical tuberculosis states on the basis of reported symptoms or signs of tuberculosis, further differentiated by likely infectiousness. The presence of viable Mycobacterium tuberculosis and an associated host response are prerequisites for all states of infection and disease. Our framework provides a clear direction for tuberculosis research, which will, in time, improve tuberculosis clinical care and elimination policies
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