494 research outputs found
A characterization of box -integral binary clutters
Let Q6 denote the port of the dual Fano matroid F*7 and let Q7 denote the clutter consisting of the circuits of the Fano matroid F7 that contain a given element. Let be a binary clutter on E and let d = 2 be an integer. We prove that all the vertices of the polytope {x E+ | x(C) = 1 for C } n {x | a = x = b} are -integral, for any -integral a, b, if and only if does not have Q6 or Q7 as a minor. This includes the class of ports of regular matroids. Applications to graphs are presented, extending a result from Laurent and Pojiak [7]
Mixed-integer vertex covers on bipartite graphs
Let be the edge-node incidence matrix of a bipartite graph
\n, be a subset of the nodes of , and be a vector such
\nthat is integral. We consider the following mixed-integer set:
\n X(G, b, I) = {x : Ax ≥ b, x ≥ 0, x_i integer for all i ∈ I}.
\nWe characterize conv in its original space. That is, we describe a matrix such that conv(X(G, b, I)) = {x : Cx ≥ d}. This
\nis accomplished by computing the projection onto the space of the -variables of an extended formulation, given in [1], for .
\nWe then give a polynomial-time algorithm for the separation problem for conv, thus showing that the problem of optimizing a linear
\nfunction over the set is solvable in polynomial time.
\
Claw-free t-perfect graphs can be recognised in polynomial time
A graph is called t-perfect if its stable set polytope is defined by
non-negativity, edge and odd-cycle inequalities. We show that it can be decided
in polynomial time whether a given claw-free graph is t-perfect
Intracellular vesicle trafficking plays an essential role in mitochondrial quality control
The Drosophila gene products Bet1, Slh, and CG10144, predicted to function in intracellular vesicle trafficking, were previously found to be essential for mitochondrial nucleoid maintenance. Here we show that Slh and Bet1 cooperate to maintain mitochondrial functions. In their absence, mitochondrial content, membrane potential, and respiration became abnormal, accompanied by mitochondrial proteotoxic stress, but without direct effects on mtDNA. Immunocytochemistry showed that both Slh and Bet1 are localized at the Golgi, together with a proportion of Rab5-positive vesicles. Some Bet1, as well as a tiny amount of Slh, cofractionated with highly purified mitochondria, while live-cell imaging showed coincidence of fluorescently tagged Bet1 with most Lysotracker-positive and a small proportion of Mitotracker-positive structures. This three-way association was disrupted in cells knocked down for Slh, although colocalized lysosomal and mitochondrial signals were still seen. Neither Slh nor Bet1 was required for global mitophagy or endocytosis, but prolonged Slh knockdown resulted in G2 growth arrest, with increased cell diameter. These effects were shared with knockdown of betaCOP but not of CG1044, Snap24, or Syntaxin6. Our findings implicate vesicle sorting at the cis-Golgi in mitochondrial quality control.Peer reviewe
Perturbation-based balance training: Principles, mechanisms and implementation in clinical practice
Since the mid-2000s, perturbation-based balance training has been gaining interest as an efficient and effective way to prevent falls in older adults. It has been suggested that this task-specific training approach may present a paradigm shift in fall prevention. In this review, we discuss key concepts and common issues and questions regarding perturbation-based balance training. In doing so, we aim to provide a comprehensive synthesis of the current evidence on the mechanisms, feasibility and efficacy of perturbation-based balance training for researchers and practitioners. We address this in two sections: “Principles and Mechanisms” and “Implementation in Practice.” In the first section, definitions, task-specificity, adaptation and retention mechanisms and the dose-response relationship are discussed. In the second section, issues related to safety, anxiety, evidence in clinical populations (e.g., Parkinson's disease, stroke), technology and training devices are discussed. Perturbation-based balance training is a promising approach to fall prevention. However, several fundamental and applied aspects of the approach need to be further investigated before it can be widely implemented in clinical practice
Context matters! The relationship between mother-reported family nutrition climate, general parenting, food parenting practices and children’s BMI
Background: Efforts to explain children’s nutrition behavior or weight often involve investigating the parent-child relationship, typically studying the associations between food parenting practices (FPPs) and child outcomes. However, these behaviors are embedded in a broader system: general parenting (GP, the general emotional climate at home), and the family health climate (an aspect of the broader family system in the context of health). In the current study, we combined the parent-child measures of parenting (FPPs and GP) and the nutritional dimension of the family health climate (family nutrition climate, FNC) to get a broader view of how these concepts are interrelated. The current study had two aims: predicting FPPs using GP and FNC as predictor variables, and investigating the relationship between FPPs and children’s weight in different groups of parents, based on low and high GP and FNC scores.
Methods: We collected cross-sectional data via an online survey panel. Mothers of 267 children aged 5–12 years filled out a questionnaire assessing demographics (e.g., children’s weight and height), GP, FPPs, and FNC. Bivariate correlation coefficients were calculated between all constructs. Structural equation modeling was performed to test the hypothesized relationships between GP, FNC and FPPs. Hereafter, different groups of parents were identified, using median split, based on a low or high score on GP or a low or high score on FNC. Bivariate correlation coefficients were calculated between FPPs and children’s BMI z-score for these different groups.
Results: GP and FNC were consistently positively correlated (all r’s ≥.177), and both concepts were positively associated with healthy FPPs (all r’s ≥.214). In families with a positive context (i.e. scoring high on GP and on FNC), healthy FPPs were associated with lower BMI z-scores of the children (r -.229). This association was not found for children with a more negative family context.
Conclusions: FNC and GP are valuable additional concepts to investigate relationships between FPPs and child outcomes. We recommend that more studies, next to investigating the parent-child system, include a measure of the broader family system, in order to get a broader view of the mechanisms explaining child health behaviors and weight status
TUGAS SEORANG PEMADU GAMBAR (SWITCHER) DI ACARA KABAR AWAN PT.TERANG ABADI TELEVISI
Beragamnya program acara yang tayang di Televisi menimbulkan
persaingan yang sangat ketat di dalam dunia Televisi. Setiap stasiun Televisi
memiliki berbagai format tayangan dan tayangan unggulan. Sehingga setiap stasiun
TV menginginkan program acara unggulannya memegang ratting tertinggi di antara
program-program acara yang lain.
Namun di balik kesuksesan suatu tayangan televisi tidak bisa dilepaskan
dari peran seorang pemadu gambar atau lebih dikenal dengan switcher yang bertugas
untuk memadukan stock gambar yang ada sehingga bisa menjadi deretan gambar
yang baik sehingga enak untuk di tonton.Oleh sebab itu, penulis ingin mengangkat
tentang peran pemadu gambar yang berperan cukup besar dalam menentukan
kesuksesan tayangan acara televisi Dalam hal ini penulis menampilkan beberapa
sudut pandang, seperti bagaimana memadukan gambar yang baik dan benar dari
kamera dan computer grafis sehingga sesuai hasil yang diinginkan.
Suatu proses memadukan stock shot gambar yang ada menjadi deretan gambar
yang bagus bukan merupakan hal yang mudah butuh ketelitian dan ketekunan untuk
bisa memilih dan meletakkan gambar sesuai dengan alur sehingga tercipta alur atau
deretan gambar yang baik. Begitu pula yang dilakukan seorang pemadu gambar di
TATV. Yang notabenenya bertugas ganda sebagai Instalasi Video Menjadi suatu
hal yang menurut penulis begitu sangat menarik untuk diketahui buat penulis sendiri
maupun buat masyarakat
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