141 research outputs found

    A fast two-stage approach for multi-goal path planning in a fruit tree

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    We consider the problem of planning the motion of a drone equipped with a robotic arm, tasked with bringing its end-effector up to many (150+) targets in a fruit tree; to inspect every piece of fruit, for example. The task is complicated by the intersection of a version of Neighborhood TSP (to find an optimal order and a pose to visit every target), and a robotic motion-planning problem through a planning space that features numerous cavities and narrow passages that confuse common techniques. In this contribution, we present a framework that decomposes the problem into two stages: planning approach paths for every target, and quickly planning between the start points of those approach paths. Then, we compare our approach by simulation to a more straightforward method based on multiquery planning, showing that our approach outperforms it in both time and solution cost

    Parallel Sparse LU Decomposition on a Mesh Network of Transputers

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    A parallel algorithm is presented for the LU decomposition of a general sparse matrix on a distributed-memory MIMD multiprocessor with a square mesh communication network. In the algorithm, matrix elements are assigned to processors according to the grid distribution. Each processor represents the nonzero elements of its part of the matrix by a local, ordered, two-dimensional linked-list data structure. The complexity of important operations on this data structure and on several others is analysed. At each step of the algorithm, a parallel search for a set of m compatible pivot elements is performed. The Markowitz counts of the pivot elements are close to minimum, to preserve the sparsity of the matrix. The pivot elements also satisfy a threshold criterion, to ensure numerical stability. The compatibility of the m pivots enables the simultaneous elimination of m pivot rows and m pivot columns in a rank-m update of the reduced matrix. Experimental results on a network of 400 transputers are presented for a set of test matrices from the Harwell–Boeing sparse matrix collection

    Augmenting neurocognitive remediation therapy to Preventive Cognitive Therapy for partially remitted depressed patients:protocol of a pragmatic multicentre randomised controlled trial

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    Introduction Major depressive disorder (MDD) affects 163 million people globally every year. Individuals who experience subsyndromal depressive symptoms during remission (ie, partial remission of MDD) are especially at risk for a return to a depressive episode within an average of 4 months. Simultaneously, partial remission of MDD is associated with work and (psycho)social impairment and a lower quality of life. Brief psychological interventions such as preventive cognitive therapy (PCT) can reduce depressive symptoms or relapse for patients in partial remission, although achieving full remission with treatment is still a clinical challenge. Treatment might be more effective if cognitive functioning of patients is targeted as well since cognitive problems are the most persisting symptom in partial remission and predict poor treatment response and worse functioning. Studies show that cognitive functioning of patients with (remitted) MDD can be improved by online neurocognitive remediation therapy (oNCRT). Augmenting oNCRT to PCT might improve treatment effects for these patients by strengthening their cognitive functioning alongside a psychological intervention. Methods and analysis This study will examine the effectiveness of augmenting oNCRT to PCT in a pragmatic national multicentre superiority randomised controlled trial. We will include 115 adults partially remitted from MDD with subsyndromal depressive symptoms defined as a Hamilton Depression Rating Scale score between 8 and 15. Participants will be randomly allocated to PCT with oNCRT, or PCT only. Primary outcome measure is the effect on depressive symptomatology over 1 year. Secondary outcomes include time to relapse, cognitive functioning, quality of life and healthcare costs. This first dual approach study of augmenting oNCRT to PCT might facilitate full remission in partially remitted individuals as well as prevent relapse over time. Ethics and dissemination Ethical approval was obtained by Academic Medical Center, Amsterdam. Outcomes will be made publicly available

    Four Work-Ins by Australian Journalists, 1944-80

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    During industrial disputes with employers between 1944 and 1980 the Australian Journalist's Association occasionally turned to the tactic of the work-in, producing wild cat newspapers during strikes in Sydney. These newspapers (The News, and The Clarion) exemplified problematic elements of the work-in as a working-class strategy. While single incident studies of the work-in have been conducted in Australia, the Australian Journalist Association work-ins present a time series of struggle. This time series allows for a broader evaluation of the radical content of the work-in and indicates that the tactic can become systematised, less radical, and less participatory when not connected to a broader generation of workplace radical behaviour by workers. In short: the work-in, much like the strike or go slow, can become a tame cat tactic – it is not inherently transgressive or opposed to capitalist production. Expectedly, the first work-ins were more radical in scope, presenting a newspaper which fully duplicated the commodity produced under capitalist control and in some ways exceeded the scope presented by capitalist organised journalism in both a material and a cultural sense. However, this radical economic potential dissipated by the end of the time series of work-ins. Instead of providing an alternative commodity fit for market, the tactic produced propaganda pieces aimed primarily at the members of the community who would be predisposed to favour the journalist's case. The 1980s Clarion was not a daily newspaper of news, sport, racing, women's interest, classifieds, and general opinion. This change will be explained in terms of human causes such as skills loss, production process causes such as computerisation and wire services, and broader social causes such as the changing role of the newspaper in Australian society.The symposium is organised on behalf of AAHANZBS by the Business and Labour History Group, The University of Sydney, with the financial support of the University’s Faculty of Economics and Business

    Protective Effects of Positive Lysosomal Modulation in Alzheimer's Disease Transgenic Mouse Models

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    Alzheimer's disease (AD) is an age-related neurodegenerative pathology in which defects in proteolytic clearance of amyloid β peptide (Aβ) likely contribute to the progressive nature of the disorder. Lysosomal proteases of the cathepsin family exhibit up-regulation in response to accumulating proteins including Aβ1–42. Here, the lysosomal modulator Z-Phe-Ala-diazomethylketone (PADK) was used to test whether proteolytic activity can be enhanced to reduce the accumulation events in AD mouse models expressing different levels of Aβ pathology. Systemic PADK injections in APPSwInd and APPswe/PS1ΔE9 mice caused 3- to 8-fold increases in cathepsin B protein levels and 3- to 10-fold increases in the enzyme's activity in lysosomal fractions, while neprilysin and insulin-degrading enzyme remained unchanged. Biochemical analyses indicated the modulation predominantly targeted the active mature forms of cathepsin B and markedly changed Rab proteins but not LAMP1, suggesting the involvement of enhanced trafficking. The modulated lysosomal system led to reductions in both Aβ immunostaining as well as Aβx-42 sandwich ELISA measures in APPSwInd mice of 10–11 months. More extensive Aβ deposition in 20-22-month APPswe/PS1ΔE9 mice was also reduced by PADK. Selective ELISAs found that a corresponding production of the less pathogenic Aβ1–38 occurs as Aβ1–42 levels decrease in the mouse models, indicating that PADK treatment leads to Aβ truncation. Associated with Aβ clearance was the elimination of behavioral and synaptic protein deficits evident in the two transgenic models. These findings indicate that pharmacologically-controlled lysosomal modulation reduces Aβ1–42 accumulation, possibly through intracellular truncation that also influences extracellular deposition, and in turn offsets the defects in synaptic composition and cognitive functions. The selective modulation promotes clearance at different levels of Aβ pathology and provides proof-of-principle for small molecule therapeutic development for AD and possibly other protein accumulation disorders

    Clinical characteristics of women captured by extending the definition of severe postpartum haemorrhage with 'refractoriness to treatment': a cohort study

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    Background: The absence of a uniform and clinically relevant definition of severe postpartum haemorrhage hampers comparative studies and optimization of clinical management. The concept of persistent postpartum haemorrhage, based on refractoriness to initial first-line treatment, was proposed as an alternative to common definitions that are either based on estimations of blood loss or transfused units of packed red blood cells (RBC). We compared characteristics and outcomes of women with severe postpartum haemorrhage captured by these three types of definitions. Methods: In this large retrospective cohort study in 61 hospitals in the Netherlands we included 1391 consecutive women with postpartum haemorrhage who received either ≥4 units of RBC or a multicomponent transfusion. Clinical characteristics and outcomes of women with severe postpartum haemorrhage defined as persistent postpartum haemorrhage were compared to definitions based on estimated blood loss or transfused units of RBC within 24 h following birth. Adverse maternal outcome was a composite of maternal mortality, hysterectomy, arterial embolisation and intensive care unit admission. Results: One thousand two hundred sixty out of 1391 women (90.6%) with postpartum haemorrhage fulfilled the definition of persistent postpartum haemorrhage. The majority, 820/1260 (65.1%), fulfilled this definition within 1 h following birth, compared to 819/1391 (58.7%) applying the definition of ≥1 L blood loss and 37/845 (4.4%) applying the definition of ≥4 units of RBC. The definition persistent postpartum haemorrhage captured 430/471 adverse maternal outcomes (91.3%), compared to 471/471 (100%) for ≥1 L blood loss and 383/471 (81.3%) for ≥4 units of RBC. Persistent postpartum haemorrhage did not capture all adverse outcomes because of missing data on timing of initial, first-line treatment. Conclusion: The definition persistent postpartum haemo
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