2,598 research outputs found

    Impact of antenna correlation on the performance of partial relay selection

    Get PDF
    Antenna correlation is generally viewed as an obstacle to realize the desired performance of a wireless system. In this article, we investigate the performance of partial relay selection in the presence of antenna correlation. We consider both channel state information (csi)-assisted and fixed gain amplify-and-forward (AF) relay schemes. The source and the destination are equipped with multiple antennas communicating via the best first hop signal-to-noise ratio (SNR) relay. We derived the closed form expression for outage probability, average symbol error rate (SER) for both schemes. Further, an exact expression is derived for the ergodic capacity in the csi-assisted relay case and an approximated expression is considered for the fixed gain case. Moreover, we provide simple asymptotic results and show that the diversity order of the system remains unchanged with the effect of antenna correlation for both types of relay schemes

    Case Report: Pheochromocytoma and Synchronous Neuroblastoma in a Family With Hereditary Pheochromocytoma Associated With a MAX Deleterious Variant

    Get PDF
    Introduction: Pheochromocytomas are rare catecholamine-producing neuroendocrine tumours arising from chromaffin cells of the adrenal medulla or extra-adrenal sympathetic paraganglia. Recent studies have indicated that up to 40% of pheochromocytomas could be attributable to an inherited germline variant in an increasing list of susceptibility genes. Germline variants of the MYC-associated factor (MAX) gene have been associated with familial pheochromocytomas and paragangliomas with an autosomal dominant pattern of inheritance, a median age at onset of 33 years and an overall frequency estimated at 1.9%. We describe a deleterious MAX variant associated with hereditary pheochromocytoma in a family with four affected individuals. Case presentation: The first patient presented with bilateral pheochromocytoma in 1995; genetic testing was proposed to his oldest son, when he was diagnosed with a bilateral pheochromocytoma with a synchronous neuroblastoma. Upon the identification of the MAX variant c.97C>T, p.(Arg33Ter), in the latter individual, his two siblings and their father were tested and the same variant was identified in all of them. Both siblings were subsequently diagnosed with pheochromocytoma (one of them bilateral) and choose to remain on active surveillance before they were submitted to adrenalectomy. All the tumours secreted predominantly norepinephrine, accordingly to the typical biochemical phenotype ascribed to variants in the MAX gene. Conclusion: This case series is, to our knowledge, the one with the largest number of individuals with hereditary pheochromocytoma with a deleterious MAX variant in the same family. It is also the first case with a synchronous pheochromocytoma and neuroblastoma in carriers of a MAX deleterious variant. This report draws attention to some ill-defined features of pheochromocytoma and other malignancies associated with a MAX variant and highlights the importance of understanding the genotype-phenotype correlation in hereditary pheochromocytoma and the impact of oriented genetic testing to detect, survey and treat patients and kindreds at risk

    Generating real-world evidence on the quality use, benefits and safety of medicines in australia: History, challenges and a roadmap for the future

    Full text link
    Australia spends more than $20 billion annually on medicines, delivering significant health benefits for the population. However, inappropriate prescribing and medicine use also result in harm to individuals and populations, and waste of precious health resources. Medication data linked with other routine collections enable evidence generation in pharmacoepidemiology; the science of quantifying the use, effectiveness and safety of medicines in real-world clinical practice. This review details the history of medicines policy and data access in Australia, the strengths of existing data sources, and the infrastructure and governance enabling and impeding evidence generation in the field. Currently, substantial gaps persist with respect to cohesive, contemporary linked data sources supporting quality use of medicines, effectiveness and safety research; exemplified by Aus-tralia’s limited capacity to contribute to the global effort in real-world studies of vaccine and dis-ease-modifying treatments for COVID-19. We propose a roadmap to bolster the discipline, and population health more broadly, underpinned by a distinct capability governing and streamlining access to linked data assets for accredited researchers. Robust real-world evidence generation requires current data roadblocks to be remedied as a matter of urgency to deliver efficient and equitable health care and improve the health and well-being of all Australians

    Innovative Metallic Microfluidic Device for Intensified Biodiesel Production

    Get PDF
    We present a strategy for intensified biodiesel production in a novel metallic microdevice. Additive manufacturing using Selective Laser Melting (SLM) was employed to build the metallic device consisting of multiple micro reactors monolithically integrated with multiple micro heat exchangers. This device allows high conversion rate of biodiesel production with concomitant use of the rejected heat from external source to enhance the reaction temperature and, thereby, its output. The biodiesel production was carried out using soybean oil, ethanol and NaOH as the catalyst. The influences of the reaction temperature and the residence time in the biodiesel production was examined. Biodiesel yield increased with the reaction temperature and a rate of conversion of 99.6% was achieved with a reactor residence time of less than 35 seconds. The work opens up a pathway to exploit waste heat to intensify biodiesel production and contribute significantly to global sustainability

    Algorithms for Cut Problems on Trees

    Full text link
    We study the {\sc multicut on trees} and the {\sc generalized multiway Cut on trees} problems. For the {\sc multicut on trees} problem, we present a parameterized algorithm that runs in time O(ρk)O^{*}(\rho^k), where ρ=2+11.555\rho = \sqrt{\sqrt{2} + 1} \approx 1.555 is the positive root of the polynomial x42x21x^4-2x^2-1. This improves the current-best algorithm of Chen et al. that runs in time O(1.619k)O^{*}(1.619^k). For the {\sc generalized multiway cut on trees} problem, we show that this problem is solvable in polynomial time if the number of terminal sets is fixed; this answers an open question posed in a recent paper by Liu and Zhang. By reducing the {\sc generalized multiway cut on trees} problem to the {\sc multicut on trees} problem, our results give a parameterized algorithm that solves the {\sc generalized multiway cut on trees} problem in time O(ρk)O^{*}(\rho^k), where ρ=2+11.555\rho = \sqrt{\sqrt{2} + 1} \approx 1.555 time

    Drought impact on forest carbon dynamics and fluxes in Amazonia

    Get PDF
    In 2005 and 2010 the Amazon basin experienced two strong droughts, driven by shifts in the tropical hydrological regime possibly associated with global climate change, as predicted by some global models. Tree mortality increased after the 2005 drought, and regional atmospheric inversion modelling showed basin-wide decreases in CO2 uptake in 2010 compared with 2011 (ref. 5). But the response of tropical forest carbon cycling to these droughts is not fully understood and there has been no detailed multi-site investigation in situ. Here we use several years of data from a network of thirteen 1-ha forest plots spread throughout South America, where each component of net primary production (NPP), autotrophic respiration and heterotrophic respiration is measured separately, to develop a better mechanistic understanding of the impact of the 2010 drought on the Amazon forest. We find that total NPP remained constant throughout the drought. However, towards the end of the drought, autotrophic respiration, especially in roots and stems, declined significantly compared with measurements in 2009 made in the absence of drought, with extended decreases in autotrophic respiration in the three driest plots. In the year after the drought, total NPP remained constant but the allocation of carbon shifted towards canopy NPP and away from fine-root NPP. Both leaf-level and plot-level measurements indicate that severe drought suppresses photosynthesis. Scaling these measurements to the entire Amazon basin with rainfall data, we estimate that drought suppressed Amazon-wide photosynthesis in 2010 by 0.38 petagrams of carbon (0.23-0.53 petagrams of carbon). Overall, we find that during this drought, instead of reducing total NPP, trees prioritized growth by reducing autotrophic respiration that was unrelated to growth. This suggests that trees decrease investment in tissue maintenance and defence, in line with eco-evolutionary theories that trees are competitively disadvantaged in the absence of growth. We propose that weakened maintenance and defence investment may, in turn, cause the increase in post-drought tree mortality observed at our plots.Gordon and Betty Moore FoundationNatural Environment Research Council (NERC)EU FP7 Amazalert (282664) projectEU FP7GEOCARBON (283080) projectNational Council for Scientific and Technological Development (CNPq, Brazil)ARC - fellowship awardERC - Advanced Investigator AwardRoyal Society - Wolfson Research Merit AwardJackson FoundationJohn Fell Fun

    Reducing the clique and chromatic number via edge contractions and vertex deletions.

    Get PDF
    We consider the following problem: can a certain graph parameter of some given graph G be reduced by at least d, for some integer d, via at most k graph operations from some specified set S, for some given integer k? As graph parameters we take the chromatic number and the clique number. We let the set S consist of either an edge contraction or a vertex deletion. As all these problems are NP-complete for general graphs even if d is fixed, we restrict the input graph G to some special graph class. We continue a line of research that considers these problems for subclasses of perfect graphs, but our main results are full classifications, from a computational complexity point of view, for graph classes characterized by forbidding a single induced connected subgraph H

    Trend analysis of the quality indicators for the Brazilian cervical cancer screening programme by region and state from 2006 to 2013

    Get PDF
    Quality indicators for the Brazilian cervical cancer screening programme can provide a perspective on its effectiveness in Brazilian macro-regions and states. The aim of this study was to perform a trend analysis of the cervical cancer screening program's quality indicators, according to Brazilian regions and states, from 2006 to 2013.(undefined)info:eu-repo/semantics/publishedVersio

    Relationship between craving and personality in treatment-seeking women with substance-related disorders

    Get PDF
    BACKGROUND: Individual differences may impact susceptibility to addiction. The impact of personality features on drug craving, however, has not been studied, particularly in women. METHODS: Ninety-five treatment-seeking women with substance dependence, abstinent for at least 5 and no more than 21 days, were investigated regarding the correlation between personality factors and craving. Personality was assessed using the Temperament and Character Inventory (TCI), the NEO Personality Inventory Revised (NEO-PI-R), and the Barratt Impulsiveness Scale version 11 (BIS-11). Cravings were assessed through the Pennsylvania Craving Scale (PCS), and the Craving Questionnaire (CQ). Anxiety and depressive symptomatology were also recorded. RESULTS: Craving scores were positively correlated with depression and negatively correlated with number of days abstinent from substance use. Also, craving scores were positively associated with the novelty-seeking factor from the TCI and the total score on the BIS-11, and negatively associated with the conscientiousness and agreeableness facets of the NEO-PI-R. CONCLUSION: Findings suggest that personality features, particularly impulsiveness, can be important predictors of craving in women, which has important implications for treatment planning
    corecore