748 research outputs found

    Heterogeneous Swarms for Maritime Dynamic Target Search and Tracking

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    Current strategies employed for maritime target search and tracking are primarily based on the use of agents following a predetermined path to perform a systematic sweep of a search area. Recently, dynamic Particle Swarm Optimization (PSO) algorithms have been used together with swarming multi-robot systems (MRS), giving search and tracking solutions the added properties of robustness, scalability, and flexibility. Swarming MRS also give the end-user the opportunity to incrementally upgrade the robotic system, inevitably leading to the use of heterogeneous swarming MRS. However, such systems have not been well studied and incorporating upgraded agents into a swarm may result in degraded mission performances. In this paper, we propose a PSO-based strategy using a topological k-nearest neighbor graph with tunable exploration and exploitation dynamics with an adaptive repulsion parameter. This strategy is implemented within a simulated swarm of 50 agents with varying proportions of fast agents tracking a target represented by a fictitious binary function. Through these simulations, we are able to demonstrate an increase in the swarm's collective response level and target tracking performance by substituting in a proportion of fast buoys.Comment: Accepted for IEEE/MTS OCEANS 2020, Singapor

    Concurrent chemotherapy (carboplatin, paclitaxel, etoposide) and involved-field radiotherapy in limited stage small cell lung cancer: a Dutch multicenter phase II study

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    To improve the prognosis of limited stage small cell lung cancer (LS-SCLC) the addition of concurrent thoracic radiotherapy to a platinum-containing regimen is important. In the Netherlands, we initiated a multicenter, phase II study, of the combination of four cycles of carboplatin (AUC 5), paclitaxel (200 mg m−2) and etoposide (2 × 50 mg orally for 5 days) combined with 45 Gy (daily fractions of 1.8 Gy). The radiation was given to the involved field and concurrently with the second and third chemotherapy cycle. Patients with a partial or complete response received prophylactic cranial irradiation to a dose of 30 Gy. From January 1999 to December 2001, 37 of the 38 patients with LS-SCLC entered were eligible for toxicity analysis and response. Grade 3 and 4 haematological toxicity occurred in 57% (21/37) with febrile neutropenia in 24% (9/37). There were no treatment-related deaths or other grade 4 toxicity. Grade 3 toxicities were oesophagitis (27%), radiation pneumonitis (6%), anorexia (14%), nausea (16%), dyspnea (19%) and lethargy (22%). The objective response rate was 92% (95% confidence interval (CI) 80–98%) with a median survival time of 19.5 months (95% CI 12.8–29.2). The 1-, 2- and 5-year survival rate was 70, 47 and 27%, respectively. In field local recurrences occurred in six patients. Distant metastases were observed in 19 patients of which 13 in the brain. This study indicates that combination chemotherapy with concurrent involved-field radiation therapy is an effective treatment for LS-SCLC. Despite PCI, the brain remained the most important site of recurrence

    Forging Links between Human Mental Retardation–Associated CNVs and Mouse Gene Knockout Models

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    Rare copy number variants (CNVs) are frequently associated with common neurological disorders such as mental retardation (MR; learning disability), autism, and schizophrenia. CNV screening in clinical practice is limited because pathological CNVs cannot be distinguished routinely from benign CNVs, and because genes underlying patients' phenotypes remain largely unknown. Here, we present a novel, statistically robust approach that forges links between 148 MR–associated CNVs and phenotypes from ∼5,000 mouse gene knockout experiments. These CNVs were found to be significantly enriched in two classes of genes, those whose mouse orthologues, when disrupted, result in either abnormal axon or dopaminergic neuron morphologies. Additional enrichments highlighted correspondences between relevant mouse phenotypes and secondary presentations such as brain abnormality, cleft palate, and seizures. The strength of these phenotype enrichments (>100% increases) greatly exceeded molecular annotations (<30% increases) and allowed the identification of 78 genes that may contribute to MR and associated phenotypes. This study is the first to demonstrate how the power of mouse knockout data can be systematically exploited to better understand genetically heterogeneous neurological disorders

    Characterization of the Antibiotic Compound No. 70 Produced by Streptomyces sp. IMV-70

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    We describe the actinomycete strain IMV-70 isolated from the soils of Kazakhstan, which produces potent antibiotics with high levels of antibacterial activity. After the research of its morphological, chemotaxonomic, and cultural characteristics, the strain with potential to be developed further as a novel class of antibiotics with chemotherapeutics potential was identified as Streptomyces sp. IMV-70. In the process of fermentation, the strain Streptomyces spp. IMV-70 produces the antibiotic no. 70, which was isolated from the culture broth by extraction with organic solvents. Antibiotic compound no. 70 was purified and separated into individual components by HPLC, TLC, and column chromatography methods. The main component of the compound is the antibiotic 70-A, which was found to be identical to the peptolide etamycin A. Two other antibiotics 70-B and 70-C have never been described and therefore are new antibiotics. The physical-chemical and biological characteristics of these preparations were described and further researched. Determination of the optimal growth conditions to cultivate actinomycete-producer strain IMV-70 and development of methods to isolate, purify, and accumulate preparations of the new antibiotic no. 70 enable us to research further the potential of this new class of antibiotics

    Mobster: Accurate detection of mobile element insertions in next generation sequencing data

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    Mobile elements are major drivers in changing genomic architecture and can cause disease. The detection of mobile elements is hindered due to the low mappability of their highly repetitive sequences. We have developed an algorithm, called Mobster, to detect non-reference mobile element insertions in next generation sequencing data from both whole genome and whole exome studies. Mobster uses discordant read pairs and clipped reads in combination with consensus sequences of known active mobile elements. Mobster has a low false discovery rate and high recall rate for both L1 and Alu elements. Mobster is available at http://sourceforge.net/projects/mobster. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13059-014-0488-x) contains supplementary material, which is available to authorized users

    Long-term quality of life and cost-effectiveness of treatment of partial thickness burns: A randomized controlled trial comparing enzyme alginogel vs silver sulfadiazine (FLAM study)

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    The clinical effectiveness and scar quality of the randomized controlled trial comparing enzyme alginogel with silver sulfadiazine (SSD) for treatment of partial thickness burns were previously reported. Enzyme alginogel did not lead to faster wound healing (primary outcome) or less scar formation. In the current study, the health-related quality of life (HRQoL), costs, and cost-effectiveness of enzyme alginogel compared with SSD in the treatment of partial thickness burns were studied. HRQoL was evaluated using the Burn Specific Health Scale-Brief (BSHS-B) and the EQ-5D-5L questionnaire 1 week before discharge and at 3, 6, and 12 months postburn. Costs were studied from a societal perspective (health care and nonhealth-care costs) for a follow-up period of 1 year. A cost-effectiveness analysis was performed using cost-effectiveness acceptability curves and comparing differences in societal costs and Quality Adjusted Life Years (QALYs) at 1 year postburn. Forty-one patients were analyzed in the enzyme alginogel group and 48 patients in the SSD group. None o

    General practitioners’ perspectives on campaigns to promote rapid help-seeking behaviour at the onset of rheumatoid arthritis

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    Objective. To explore general practitioners’ (GPs’ ) perspectives on public health campaigns to encourage people with the early symptoms of rheumatoid arthritis (RA) to seek medical help rapidly. Design. Nineteen GPs participated in four semistructured focus groups. Focus groups were audio-recorded, transcribed verbatim, and analysed using thematic analysis. Results. GPs recognised the need for the early treatment of RA and identified that facilitating appropriate access to care was important. However, not all held the view that a delay in help seeking was a clinically significant issue. Furthermore, many were concerned that the early symptoms of RA were often non-specific, and that current knowledge about the nature of symptoms at disease onset was inadequate to inform the content of a help-seeking campaign. They argued that a campaign might not be able to specifically target those who need to present urgently. Poorly designed campaigns were suggested to have a negative impact on GPs’ workloads, and would “clog up” the referral pathway for genuine cases of RA. Conclusions. GPs were supportive of strategies to improve access to Rheumatological care and increase public awareness of RA symptoms. However, they have identified important issues that need to be considered in developing a public health campaign that forms part of an overall strategy to reduce time to treatment for patients with new onset RA. This study highlights the value of gaining GPs’ perspectives before launching health promotion campaigns

    Mixed exciton–charge-transfer states in photosystem II: Stark spectroscopy on site–directed mutants

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    AbstractWe investigated the electronic structure of the photosystem II reaction center (PSII RC) in relation to the light-induced charge separation process using Stark spectroscopy on a series of site-directed PSII RC mutants from the cyanobacterium Synechocystis sp. PCC 6803. The site-directed mutations modify the protein environment of the cofactors involved in charge separation (PD1, PD2, ChlD1, and PheD1). The results demonstrate that at least two different exciton states are mixed with charge-transfer (CT) states, yielding exciton states with CT character: (PD2δ+PD1δ−ChlD1)∗673nm and (ChlD1δ+PheD1δ−)∗681nm (where the subscript indicates the wavelength of the electronic transition). Moreover, the CT state PD2+PD1− acquires excited-state character due to its mixing with an exciton state, producing (PD2+PD1−)δ∗684nm. We conclude that the states that initiate charge separation are mixed exciton-CT states, and that the degree of mixing between exciton and CT states determines the efficiency of charge separation. In addition, the results reveal that the pigment-protein interactions fine-tune the energy of the exciton and CT states, and hence the mixing between these states. This mixing ultimately controls the selection and efficiency of a specific charge separation pathway, and highlights the capacity of the protein environment to control the functionality of the PSII RC complex

    Mental status and health-related quality of life in an elderly population 15 years after limited cerebral ischaemia

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    BACKGROUND: Stroke has a major impact on survivors. Our study was designed to describe the mental status and health-related quality of life (HRQoL) in long-term survivors of TIA or minor ischaemic stroke (MIS) and evaluate associations of mental and physical factors with HR-QoL. METHODS: A random sample of the 10-year survivors of the Dutch TI
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