52 research outputs found

    Distributed Optimization of Multi-Robot Motion with Time-Energy Criterion

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    This paper is an application of a special case of distributed optimization problem. It is applied on optimizing the motion of multiple robot systems. The problem is decomposed into L subproblems with L being the number of robot systems. This decomposition reduces the problem to solving a single robot problem. The optimization problem is solved via a distributed algorithm, utilizing subgradient method. A global objective function is set as the sum of individual robot objectives in time and energy. Constraints are divided into two sets, namely, robot-individual constraints and robots’ interactions (collision) constraints. The approach is applied for the case of wheeled mobile robots: we are able to generate in parallel for each robot an optimized control input trajectory and then illustrate it in simulation examples

    Comparative analysis of diversity based on morphoagronomic traits and molecular markers in durum wheat under heat stress

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    The objectives of this study were to compare the application and utility of sequence-related amplified polymorphism (SRAP) and target region amplification polymorphism (TRAP) techniques for the analysis of genetic diversity among durum wheat genotypes under heat stress and to compare genetic diversity estimated using molecular markers with morpho-agronomic performance under heat stress. Six durum wheat genotypes were used in this study. They were evaluated phenotypically for heat tolerance. The dendrogram generated from standardized morpho-agronomic data separated the six durum wheat genotypes into three main groups. The dendrogram generated from the standardized morpho-agronomic data separated the six durum wheat genotypes into three clusters, which diverged at similarity index of 0.72. The dendrogram based on SRAP markers differed from that based on TRAP markers. The combined dendrogram (SRAP, TRAP and morpho-agronomic data) agrees better with the grouping of these durum wheat genotypes depending on pedigree and the dendrogram generated by morpho-agronomic data alone.Key words: Durum wheat, genetic diversity, heat tolerance, morpho-agronomic, sequence-related amplified polymorphism (SRAP) markers, target region amplification polymorphism (TRAP) markers

    Bulked segregant analysis to detect quantitative trait loci (QTL) related to heat tolerance at grain filling rate in wheat using simple sequence repeat (SSR) markers

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    The grain-filling rate (GFR) plays an important role in determining grain yield. An F2 population of wheat was developed from a cross between the 2 wheat cultivars, Ksu106 (heat-tolerant) and Yecora Rojo (heat-sensitive). The parents and 205 F2 plants were planted on the 20th of January during the winter season of 2009 to evaluate heat tolerance during the grain-filling period. The sowing date in the present investigation represents the heat stress conditions in Saudi Arabia. Bulked – segregant analyses (BSA) was used in conjunction with simple sequence repeats (SSR) analysis to find markers linked to genes of heat tolerance. Composite interval mapping was used for mapping quantitative trait loci (QTL). The results reveal that 12 SSR markers: Wmc24, Wmc168, Wmc326, Xgwm30, Xgwm456, Wmc25, Wmc44, Wmc94, Wmc161, Wmc273, Wmc327 and Xgwm566 were linked to GFR by QTLs analysis of the F2 population. The results show that regression analysis for the relationship between the 12 markers and the phenotypes of F2 individuals were highly significant. The results demonstrate that SSR markers combined with bulked segregant analysis could be used to identify molecular markers linked to the grain filling rate as an indicator for heat tolerance in wheat.Keywords: Grain filling rate, QTL analysis, SSR marker, whea

    Arabic Speaker-Independent Continuous Automatic Speech Recognition Based on a Phonetically Rich and Balanced Speech Corpus

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    This paper describes and proposes an efficient and effective framework for the design and development of a speaker-independent continuous automatic Arabic speech recognition system based on a phonetically rich and balanced speech corpus. The speech corpus contains a total of 415 sentences recorded by 40 (20 male and 20 female) Arabic native speakers from 11 different Arab countries representing the three major regions (Levant, Gulf, and Africa) in the Arab world. The proposed Arabic speech recognition system is based on the Carnegie Mellon University (CMU) Sphinx tools, and the Cambridge HTK tools were also used at some testing stages. The speech engine uses 3-emitting state Hidden Markov Models (HMM) for tri-phone based acoustic models. Based on experimental analysis of about 7 hours of training speech data, the acoustic model is best using continuous observation’s probability model of 16 Gaussian mixture distributions and the state distributions were tied to 500 senones. The language model contains both bi-grams and tri-grams. For similar speakers but different sentences, the system obtained a word recognition accuracy of 92.67% and 93.88% and a Word Error Rate (WER) of 11.27% and 10.07% with and without diacritical marks respectively. For different speakers with similar sentences, the system obtained a word recognition accuracy of 95.92% and 96.29% and a WER of 5.78% and 5.45% with and without diacritical marks respectively. Whereas different speakers and different sentences, the system obtained a word recognition accuracy of 89.08% and 90.23% and a WER of 15.59% and 14.44% with and without diacritical marks respectively

    Identification of new SSR markers linked to leaf chlorophyll content, flag leaf senescence and cell membrane stability traits in wheat under water stressed condition

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    Segregating F4 families from the cross between drought sensitive (Yecora Rojo) and drought tolerant (Pavon 76) genotypes were made to identify SSR markers linked to leaf chlorophyll content, flag leaf senescence and cell membrane stability traits in wheat (Triticum aestivum L.) under water-stressed condition and to map quantitative trait locus (QTL) for the three physiological traits. The parents and 150 F4 families were evaluated phenotypically for drought tolerance using two irrigation treatments (2500 and 7500 m3/ha). Using 400 SSR primers tested for polymorphism in testing parental and F4 families genotypes, the results revealed that QTL for leaf chlorophyll content, flag leaf senescence and cell membrane stability traits were associated with 12, 5 and 12 SSR markers, respectively and explained phenotypic variation ranged from 6 to 42%. The SSR markers for physiological traits had genetic distances ranged from 12.5 to 25.5 cM. These SSR markers can be further used in breeding programs for drought tolerance in wheat

    HiatoGast 1: an exploring, semiblinded trial establishing a new endoscopical categorisation of axial hiatal hernias

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    Introduction Axial hiatal hernias are a common incidental finding in endoscopical examinations, but reflux symptoms do not necessarily correspond to the presence of hiatal hernias. Diagnosing a reflux disease is difficult due to a leak of existing distinct criteria, especially in order to evaluate a surgical indication. Also a preoperative measurement of the hernia is necessary to choose between surgical options. Methods and analysis We planned a semiblinded trial including a questionnaire and an oesophagogastroduodenoscopy afterwards. While the endoscopy is done, the hiatus oesophagi should be measured in inversion technique under maximum insufflation including length, width and herniated volume. A sample of 210 participants until December 2020 is determined to evaluate the primary endpoint: we look forward to evaluate the anatomical parameters of reflux and non-reflux participants. Ethics and Dissemination The study has been approved by the local ethics committee on 12th February 2019, the data will bei published after closure of inclusion. Trial registration number German Clinical Trials Register (DRKS00016863)

    The impact of surgical experience and frequency of practice on perioperative outcomes in pancreatic surgery

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    Objective We aimed to determine the impact of surgical experience and frequency of practice on perioperative morbidity and mortality in pancreatic surgery. Methods 1281 patients that underwent pancreatic resections from 1993 to 2013 were retrospectively analyzed using logistic regression models. All cases were stratified according to the surgeon’s level of experience, which was based on the number of previously performed pancreatic resections and the extent of received supervision (novice: n  90 / none). Additional stratification was based on the frequency of practice (sporadic: 3 resections > 6 weeks, frequent: 3 resections ≤6 weeks). Results The novice and experienced categories were related to a decreased risk of postoperative pancreatic fistulas (odds ratio [OR] 0.46, 95% confidence interval [CI] 0.26–0.82 and 0.54, 95% CI 0.36–0.82) and in-hospital mortality (OR 0.45, 95% CI 0.17–1.16 and 0.42, 95% CI 0.21–0.83) compared to the intermediate category. Frequent practice was associated with a significantly lower risk of delayed gastric emptying (OR 0.56, 95% CI 0.38–0.83), postpancreatectomy hemorrhage (OR 0.64, 95% CI 0.42–0.98) and in-hospital mortality (OR 0.45, 95% CI 0.24–0.87). Conclusions Our results emphasize the importance of supervision within a pancreatic surgery training program. In addition, our data underline the need of a sufficient patient caseload to ensure frequent practice

    Innate PD-L1 limits T cell–mediated adipose tissue inflammation and ameliorates diet-induced obesity

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    Obesity has become a major health problem in the industrialized world. Immune regulation plays an important role in adipose tissue homeostasis; however, the initial events that shift the balance from a noninflammatory homeostatic environment toward inflammation leading to obesity are poorly understood. Here, we report a role for the costimulatory molecule programmed death-ligand 1 (PD-L1) in the limitation of diet-induced obesity. Functional ablation of PD-L1 on dendritic cells (DCs) using conditional knockout mice increased weight gain and metabolic syndrome during diet-induced obesity, whereas PD-L1 expression on type 2 innate lymphoid cells (ILC2s), T cells, and macrophages was dispensable for obesity control. Using in vitro cocultures, DCs interacted with T cells and ILC2s via the PD-L1:PD-1 axis to inhibit T helper type 1 proliferation and promote type 2 polarization, respectively. A role for PD-L1 in adipose tissue regulation was also shown in humans, with a positive correlation between PD-L1 expression in visceral fat of people with obesity and elevated body weight. Thus, we define a mechanism of adipose tissue homeostasis controlled by the expression of PD-L1 by DCs, which may be a clinically relevant finding with regard to immune-related adverse events during immune checkpoint inhibitor therapy
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