89 research outputs found

    Einflüsse geschlossener und offener Augen auf die spontane Hirnaktivität im Dunkeln

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    Die Wahl der Ruhebedingung hat einen beträchtlichen Einfluss auf die Interpretation von Hirnaktivierungsstudien. In der Studie, die die beiden Ruhebedingungen Augen-auf und Augen-zu in Dunkelheit miteinander vergleicht, erhält man aufgabenunabhängige Deaktivierungen im visuellen Cortex, die allein durch die Öffnung der Augen induziert werden. Die Ergebnisse dieser Studie legen nahe, dass es zwei verschiedene Lidschluss-abhängige mentale Zustände gibt: einen "interozeptiven" Zustand mit geschlossenen Augen, der durch Aktivität in Arealen, die der Imagination und sensorischen Systemen zugeordnet werden, gekennzeichnet ist; und einen "exterozeptiven" Zustand mit offenen Augen, der durch Aktivierungen in Aufmerksamkeits- und Okulomotorik-Arealen charakterisiert ist. Diese Grundaktivität bestimmter Systeme in einem der beiden Zustände können z. B. bei einer visuellen Hirnaktivierungsstudie dazu führen, dass Aktivierungen, die durch einen tatsächlichen visuellen Reiz ausgelöst werden, unentdeckt bleiben oder geringer ausfallen, wenn man die Ruhebedingung Augen-zu wählt. Diese Hypothese konnte mit der Folgestudie belegt werden. Die Aktivierung des okulomotorischen Systems und die Deaktivierung sensorischer Areale während der Fixationsaufgabe bleiben mit der Ruhebedingung Augen-auf unentdeckt. Daher hat die Wahl der Ruhebedingung tatsächlich einen großen Einfluss auf Entstehung und Interpretation stimulus-induzierter Hirnaktivierungsmuster

    Parameterized Complexity of Weighted Multicut in Trees

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    The \textsc{Edge Multicut} problem is a classical cut problem where given an undirected graph GG, a set of pairs of vertices P\mathcal{P}, and a budget kk, the goal is to determine if there is a set SS of at most kk edges such that for each (s,t)∈P(s,t) \in \mathcal{P}, G−SG-S has no path from ss to tt. \textsc{Edge Multicut} has been relatively recently shown to be fixed-parameter tractable (FPT), parameterized by kk, by Marx and Razgon [SICOMP 2014], and independently by Bousquet et al. [SICOMP 2018]. In the weighted version of the problem, called \textsc{Weighted Edge Multicut} one is additionally given a weight function wt:E(G)→N\texttt{wt} : E(G) \to \mathbb{N} and a weight bound ww, and the goal is to determine if there is a solution of size at most kk and weight at most ww. Both the FPT algorithms for \textsc{Edge Multicut} by Marx et al.\ and Bousquet et al.\ fail to generalize to the weighted setting. In fact, the weighted problem is non-trivial even on trees and determining whether \textsc{Weighted Edge Multicut} on trees is FPT was explicitly posed as an open problem by Bousquet et al.\ [STACS 2009]. In this article, we answer this question positively by designing an algorithm which uses a very recent result by Kim et al.\ [STOC 2022] about directed flow augmentation as subroutine. We also study a variant of this problem where there is no bound on the size of the solution, but the parameter is a structural property of the input, for example, the number of leaves of the tree. We strengthen our results by stating them for the more general vertex deletion version

    Domination and Cut Problems on Chordal Graphs with Bounded Leafage

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    The leafage of a chordal graph GG is the minimum integer â„“\ell such that GG can be realized as an intersection graph of subtrees of a tree with â„“\ell leaves. We consider structural parameterization by the leafage of classical domination and cut problems on chordal graphs. Fomin, Golovach, and Raymond~[ESA~20182018, Algorithmica~20202020] proved, among other things, that \textsc{Dominating Set} on chordal graphs admits an algorithm running in time 2O(â„“2)â‹…nO(1)2^{\mathcal{O}(\ell^2)} \cdot n^{\mathcal{O}(1)}. We present a conceptually much simpler algorithm that runs in time 2O(â„“)â‹…nO(1)2^{\mathcal{O}(\ell)} \cdot n^{\mathcal{O}(1)}. We extend our approach to obtain similar results for \textsc{Connected Dominating Set} and \textsc{Steiner Tree}. We then consider the two classical cut problems \textsc{MultiCut with Undeletable Terminals} and \textsc{Multiway Cut with Undeletable Terminals}. We prove that the former is \textsf{W}[1]-hard when parameterized by the leafage and complement this result by presenting a simple nO(â„“)n^{\mathcal{O}(\ell)}-time algorithm. To our surprise, we find that \textsc{Multiway Cut with Undeletable Terminals} on chordal graphs can be solved, in contrast, in nO(1)n^{\mathcal{O}(1)}-time

    Urinary soluble VCAM-1 is a useful biomarker of disease activity and treatment response in lupus nephritis

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    Introduction: Vascular cell adhesion molecule-1 (VCAM-1) is involved in the progression of glomerular and tubulointerstitial injury in lupus nephritis (LN) and can be easily assessed in urine. The aim of this study was to assess urinary soluble VCAM-1 (uVCAM-1) as a biomarker of disease activity and treatment response in LN. Methods: This prospective study enrolled 62 patients with class III, IV or V LN diagnosed within the last 3 years and divided them in two groups: with and without active nephritis at the inclusion, each group with 31 patients. At each visit, a urine sample was collected for uVCAM-1 evaluation and the nephritis status was assessed. Results: Median uVCAM-1 level was elevated in patients with active compared to inactive LN (P < 0.001). The ROC curve of uVCAM-1 demonstrated an AUC of 0.84 and a cutoff of 47.2 ng/mgCr yielded a good sensitivity (74.2%) and specificity (74.2%) for the diagnosis of active LN. A significant correlation was found between uVCAM-1 level and renal activity scores and traditional biomarkers of LN. The level of uVCAM-1 dropped in patients with active LN who went into remission (P < 0.001), increased in patients who went into activity (P = 0.002) and did not change in patients who remained inactive (P = 0.797). The level of uVCAM-1 peaked during the flare of LN (P < 0.05). Conclusion: The uVCAM-1 is a reliable biomarker that reflects renal disease activity and is useful for monitoring individual patients with lupus nephritis over time

    Greater Engagement in Gender-Sexuality Alliances (GSAs) and GSA Characteristics Predict Youth Empowerment and Reduced Mental Health Concerns

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    Extracurricular groups can promote healthy development, yet the literature has given limited attention to indirect associations between extracurricular involvement and mental health or to sexual and gender minority youth. Among 580 youth (Mage = 15.59, range = 10–20 years) and adult advisors in 38 Gender-Sexuality Alliances (GSAs), multilevel structural equation models showed that greater engagement in GSAs over the school year predicted increased perceived peer validation, self-efficacy to promote social justice, and hope (baseline adjusted). Through increased hope, greater engagement indirectly predicted reduced depressive and anxiety symptoms at the year’s end (baseline adjusted). GSAs whose members had more mental health discussions and more meetings reported reduced mental health concerns. Findings suggest how groups addressing issues of equity and justice improve members’ health

    This other atmosphere: against human resources, Emoji, and devices

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    Frequently humans are invited to engage with modern visual forms: emoji, emoticons, pictograms. Some of these forms are finding their ways into the workplace, understood as augmentations to workplace atmospheres. What has been called the ‘quantified workplace’ requires its workers to log their rates of stress, wellbeing, their subjective sense of productivity on scale of 1-5 or by emoji, in a context in which HR professionals develop a vocabulary of Workforce Analytics, People Analytics, Human Capital Analytics or Talent Analytics, and all this in the context of managing the work environment or its atmosphere. Atmosphere is mood, a compote of emotions. Emotions are a part of a human package characterised as ‘the quantified self’, a self intertwined with - subject to but also compliant with - tracking and archiving. The logical step for managing atmospheres is to track emotions at a granular and largescale level. Through the concept of the digital crowd, rated and self-rating, as well as emotion tracking strategies, the human resource (as worker and consumer) engages in a new politics of the crowd, organised around what political philosopher Jodi Dean calls, affirmatively, ‘secondary visuality’, high circulation communication fusing together speech, writing and image as a new form. This is the visuality of communicative, or social media, capitalism. But to the extent that it is captured by HR, is it an exposure less to crowdsourced democracy, and more a stage in turning the employee into an on-the-shelf item in a digital economy warehouse, assessed by Likert scales? While HR works on new atmospheres of work, what other atmospheres pervade the context of labour, and can these be deployed in the generation of other types of affect, ones that work towards the free association of labour and life

    In Silico Modeling of Immunotherapy and Stroma-Targeting Therapies in Human Colorectal Cancer.

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    Despite the fact that the local immunological microenvironment shapes the prognosis of colorectal cancer, immunotherapy has shown no benefit for the vast majority of colorectal cancer patients. A better understanding of the complex immunological interplay within the microenvironment is required. In this study, we utilized wet lab migration experiments and quantitative histological data of human colorectal cancer tissue samples (n = 20) including tumor cells, lymphocytes, stroma, and necrosis to generate a multiagent spatial model. The resulting data accurately reflected a wide range of situations of successful and failed immune surveillance. Validation of simulated tissue outcomes on an independent set of human colorectal cancer specimens (n = 37) revealed the model recapitulated the spatial layout typically found in human tumors. Stroma slowed down tumor growth in a lymphocyte-deprived environment but promoted immune escape in a lymphocyte-enriched environment. A subgroup of tumors with less stroma and high numbers of immune cells showed high rates of tumor control. These findings were validated using data from colorectal cancer patients (n = 261). Low-density stroma and high lymphocyte levels showed increased overall survival (hazard ratio 0.322, P = 0.0219) as compared with high stroma and high lymphocyte levels. To guide immunotherapy in colorectal cancer, simulation of immunotherapy in preestablished tumors showed that a complex landscape with optimal stroma permeabilization and immune cell activation is able to markedly increase therapy response in silico These results can help guide the rational design of complex therapeutic interventions, which target the colorectal cancer microenvironment. Cancer Res; 77(22); 6442-52. (c)2017 AACR

    CLUH regulates mitochondrial metabolism by controlling translation and decay of target mRNAs

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    Mitochondria are essential organelles that host crucial metabolic pathways and produce adenosine triphosphate. The mitochondrial proteome is heterogeneous among tissues and can dynamically change in response to different metabolic conditions. Although the transcriptional programs that govern mitochondrial biogenesis and respiratory function are well known, posttranscriptional regulatory mechanisms remain unclear. In this study, we show that the cytosolic RNA-binding protein clustered mitochondria homologue (CLUH) regulates the expression of a mitochondrial protein network supporting key metabolic programs required under nutrient deprivation. CLUH exerts its function by controlling the stability and translation of target messenger RNAs. In the absence of Cluh, mitochondria are severely depleted of crucial enzymes involved in catabolic energy-converting pathways. CLUH preserves oxidative mitochondrial function and glucose homeostasis, thus preventing death at the fetal–neonatal transition. In the adult liver, CLUH ensures maximal respiration capacity and the metabolic response to starvation. Our results shed new light on the posttranscriptional mechanisms controlling the expression of mitochondrial proteins and suggest novel strategies to tailor mitochondrial function to physiological and pathological conditions.Peer reviewe
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