155 research outputs found

    Pendekatan Linear Programming Untuk Persoalan Pemotongan Stok (Pola Pemotongan Satu Dimensi)

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    In this study, one-dimensional cutting pattern is discussed. This includes fulfilling demands for some items with different lengths by cutting some stocks of standard length available. In this problem, the patterns – the way the standard length is cut – is obtained in such an optimal ways that the trim loss becomes as minimum as possible. The decision variables are the amount of the standard lengths cut according to certain patterns. Then the problem is formulated into a linear programming model. Due to very large number of the variables and restriction to integers, the problem is the type of large scale linear integer programming. For simplicity, restriction to integer is dropped. Then the very large number of the variables is handled by considering only the favorable cutting patterns; list of all possibleways in which a standard stock may be cut is not needed. The favorable cutting pattern is then generated by using column generation technique by solving auxiliary problem in the form of a knapsack problem. The integer optimal solution is obtained by rounding it upwar

    Estratégias de comercialização do feijão produzido por agricultores familiares da região Leste de Goiás.

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    A pesquisa teve como objetivo principal identificar as estratégias de comercialização do feijão oriundo da agricultura familiar, assim como a principal safra, as variedades produzidas e o destino dessa produção de feijão.CONAF

    Vulnerable and forgotten: The impact of the COVID-19 pandemic on autism special schools in England

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    The COVID-19 pandemic has caused, and continues to cause, unprecedented disruption in England. The impact of the pandemic on the English education system has been significant, especially for children and young people with special educational needs and disabilities (SEND). While it was encouraging that the educational rights of children and young people with SEND were highlighted during the COVID-19 pandemic, Government decision-making appeared to be centered around the needs of pupils in mainstream schools. In this article, co-authored by an academic researcher and senior leaders from the Pan London Autism Schools Network (PLASN; a collective of special schools in London and the South East of England, catering for pupils on the autistic spectrum), we reflect on the impact of the COVID-19 pandemic on special schools in England. We document and discuss a range of challenges experienced by PLASN schools, including the educational inequalities that were exposed and perpetuated by the COVID-19 pandemic, as well as the manner in which the needs and realities of special schools were overlooked by the Government. We also detail the creative and innovative solutions implemented by PLASN schools to overcome barriers that they encountered. These solutions centered on facilitating holistic approaches to support, ensuring clear and regular communication with families, providing effective support for home learning, and promoting collaborative ways of working; all of which align with good practice principles in autism education more generally, and are essential elements of practice to maintain post-pandemic. We additionally reflect on how the COVID-19 pandemic could be a catalyst for much-needed change to the SEND system: leading to better educational provision, and therefore better outcomes, for pupils with SEND

    Probing nanoscale spatial distribution of plasmonically excited hot carriers

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    表面等离激元(SP)效应可产生远高于热平衡下费米能级能量的热电子-空穴对(热载流子),从而能够引发和促进相关的光电或者化学过程,为在纳米尺度上高效利用光能实现物质和能量转化提供了极为有效的手段,化学化工学院任斌教授课题组利用前期自主发展的电化学针尖增强拉曼光谱技术,通过调控电位开关SP热载流子催化的反应,实现了有效热载流子催化反应区域的纳米分辨成像,使反应区域在实空间的分布可视化。实验上获得了有效热载流子的输运距离,从而证明了能量越高的热载流子越需要在更短的输运距离范围内收集捕获。 该工作在任斌教授和王翔副教授的共同指导下完成。实验主要由化学化工学院已毕业博士生黄声超完成。理论计算主要由电子科学与技术学院的朱锦峰副教授和已毕业硕士生李察微完成。此外,化学化工学院已毕业硕士生赵庆庆、博后何玉韩和胡树等人也参与了部分研究与课题讨论。【Abstract】Surface plasmons (SPs) of metals enable the tight focusing and strong absorption of light to realize an efficient utilization of photons at nanoscale. In particular, the SP-generated hot carriers have emerged as a promising way to efficiently drive photochemical and photoelectric processes under moderate conditions. In situ measuring of the transport process and spatial distribution of hot carriers in real space is crucial to efficiently capture the hot carriers.Here, we use electrochemical tip-enhanced Raman spectroscopy (EC-TERS) to in situmonitor an SP-driven decarboxylation and resolve the spatial distribution of hot carriers with a nanometer spatial resolution. The transport distance of about 20 nm for the reactive hot carriers is obtained from the TERS imaging result. The hot carriers with a higher energy have a shorter transport distance. These conclusions can be guides for the design and arrangement of reactants and devices to efficiently make use of plasmonic hot carriers.The authors acknowledge the financial supports from MOST of China (2016YFA0200601), NSFC (21633005, 21790354, 21503181, 21711530704, U1830116), Natural Science Foundation of Fujian Province (2016J05046), China Postdoctoral Science Foundation (2017M622062) and the Fundamental Research Funds for the Central Universities (20720190010).本研究工作得到了国家自然科学基金委和科技部等的资助和支持

    Val103Ile polymorphism of the melanocortin-4 receptor gene (MC4R) in cancer cachexia

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    <p>Abstract</p> <p>Background</p> <p>At present pathogenic mechanisms of cancer cachexia are poorly understood. Previous evidence in animal models implicates the melanocortin-4 receptor gene (<it>MC4R</it>) in the development of cancer cachexia. In humans, <it>MC4R </it>mutations that lead to an impaired receptor function are associated with obesity; in contrast, the most frequent polymorphism (Val103Ile, rs2229616; heterozygote frequency approximately 2%) was shown to be negatively associated with obesity. We tested if cancer patients that are homo-/heterozygous for the Val103Ile polymorphism are more likely to develop cachexia and/or a loss of appetite than non-carriers of the 103Ile-allele.</p> <p>Methods</p> <p>BMI (body mass index in kg/m<sup>2</sup>) of 509 patients (295 males) with malignant neoplasms was determined; additionally patients were asked about premorbid/pretherapeutical changes of appetite and weight loss. Cachexia was defined as a weight loss of at least 5% prior to initiation of therapy; to fulfil this criterion this weight loss had to occur independently of other plausible reasons; in single cases weight loss was the initial reason for seeing a physician. The average age in years (± SD) was 59.0 ± 14.5 (males: 58.8 ± 14.0, females 59.2 ± 14.0). Blood samples were taken for genotyping of the Val103Ile by PCR- RFLP.</p> <p>Results</p> <p>Most of the patients suffered from lymphoma, leukaemia and gastrointestinal tumours. 107 of the patients (21%) fulfilled our criteria for cancer cachexia. We did not detect association between the Val103Ile polymorphism and cancer cachexia. However, if we exploratively excluded the patients with early leucaemic stages, we detected a trend towards the opposite effect (p < 0.05); heterozygotes for the 103Ile-allele developed cancer cachexia less frequently in comparison to the rest of the study group. Changes of appetite were not associated with the 103Ile-allele carrier status (p > 0.39).</p> <p>Conclusion</p> <p>Heterozygotes for the 103Ile-allele are not more prone to develop cancer cachexia than patients without this allele; possibly, Ile103 carriers might be more resistant to cancer cachexia in patients with solid tumors. Further studies of the melanocortinergic system in cachexia of patients with solid tumors are warranted.</p

    Chlamydial Pre-Infection Protects From Subsequent Herpes Simplex Virus-2 Challenge in a Murine Vaginal Super-Infection Model

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    This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Chlamydia trachomatis and Herpes Simplex Virus-2 (HSV-2) genital tract co-infections have been reported in humans and studied in vitro but the clinical consequences are unknown. Limited epidemiologic evidence suggests that these co-infections could be more severe than single infections of either pathogen, but the host-pathogen interactions during co-infection remain uncharacterized. To determine whether disease progression and/or pathogen shedding differs between singly-infected and super-infected animals, we developed an in vivo super-infection model in which female BALB/c mice were vaginally infected with Chlamydia muridarum (Cm) followed later by HSV-2. Pre-infection with Chlamydia 3 or 9 days prior to HSV-2 super-infection conferred significant protection from HSV-2-induced neurologic disease and significantly reduced viral recovery compared to HSV-2 singlyinfected controls. Neither protection from mortality nor reduced viral recovery were observed when mice were i) super-infected with HSV-2 on day 27 post Cm; ii) infected with UV-irradiated Cm and super-infected with HSV-2; or iii) azithromycin-treated prior to HSV-2 super-infection. Therefore, protection from HSV-2-induced disease requires active infection with viable chlamydiae and is not observed after chlamydial shedding ceases, either naturally or due to antibiotic treatment. Thus, Chlamydia-induced protection is transient and requires the continued presence of chlamydiae or their components. These data demonstrate that chlamydial pre-infection can alter progression of subsequent HSV-2 infection, with implications for HSV-2 transmission from co-infected humans
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