262 research outputs found
Towards Integrated Perception and Motion Planning with Distributionally Robust Risk Constraints
Safely deploying robots in uncertain and dynamic environments requires a
systematic accounting of various risks, both within and across layers in an
autonomy stack from perception to motion planning and control. Many widely used
motion planning algorithms do not adequately incorporate inherent perception
and prediction uncertainties, often ignoring them altogether or making
questionable assumptions of Gaussianity. We propose a distributionally robust
incremental sampling-based motion planning framework that explicitly and
coherently incorporates perception and prediction uncertainties. We design
output feedback policies and consider moment-based ambiguity sets of
distributions to enforce probabilistic collision avoidance constraints under
the worst-case distribution in the ambiguity set. Our solution approach, called
Output Feedback Distributionally Robust (OFDR-, produces
asymptotically optimal risk-bounded trajectories for robots operating in
dynamic, cluttered, and uncertain environments, explicitly incorporating
mapping and localization error, stochastic process disturbances, unpredictable
obstacle motion, and uncertain obstacle locations. Numerical experiments
illustrate the effectiveness of the proposed algorithm
Aromatic ring cleavage of a β-biphenyl ether dimer catalyzed by lignin peroxidase of phanerochaete chrysosporium
AbstractUnder aerobic conditions homogeneous lignin peroxidase catalyzed the oxidation of 1-(4'-methoxyphenyl)-2-(2″,5′-dimethoxy-4″-phenylphenoxy)-1,3-dihydroxypropane (I) to yield four products: 1-(4'-methoxy-phenyl)-1,2,3-trihydroxypropane (X), 4-[α-hydroxy-α-(4'-methoxyphenyl)-methyl]-1,3-dioxolane-2-one (V), 4-(4'-methoxyphenyl)-5-hydroxymethyl-1,3-dioxolane-2-one (VI) and 5-hydroxy-5-carbomethoxy-4-phenyl-oxol-3-en-2-one (VIII). V, VI and VIII are all products of ring opening reactions. When the reaction was conducted under anaerobic conditions, the substrate was oxidized but no ring-cleaved products were detected. During the oxidation of I, 4 atoms of 18O from 18O2 were incorporated into the lactol product VIII
Computer simulation modeling for prediction of the extent of adoption of shrimp culture technologies (This paper is the part of the Ph.D thesis which got Jawaharlal Nehru Award 2006 for Outstanding Research in Social Sciences
Computer Simulation Modeling was used to Predict/forecast the extent of adoption of Shrimp Culture technologies by
Shrimp farmers. The adoption behaviour of 120 Shrimp farmers was studied for the years ranging from 1997 to 2003 and the
data was used to predict/ forecast the adoption behaviour for the years 2004 to 2020. The forecast values generated by the
Baal Strap Computer Simulation model suggested a gradual increase in the overall extent of adoption from 2004 onwards
which rises to reach a maximum value of 85.81 per cent in 2010. From 2011 onwards the model predicts a gradual decrease in
the overall extent of adoption and continues to show th is trend until in 2020 the overall extent of adoption reaches 80.53 per
cent. Besides, the model generated a goodness-of- fit value of 0.984 7 which indicated that the model explained 98.47 per cent
of the prediction / forecasting of the overall extent of adoption of Shrimp culture technologies
Schistosomiasis and the risk of bladder cancer in Alexandria, Egypt.
The relationship between history of schistosomiasis and bladder cancer risk was investigated using data from a case-control study conducted between January 1994 and July 1996 in Alexandria, Egypt. Cases were 190 subjects with incident, histologically confirmed invasive cancer of the bladder, and controls were 187 subjects admitted to hospital for acute, non-neoplastic, non-urinary tract conditions. Eighty-six cases (45%) vs 69 controls (37%) reported a history of urinary schistosomiasis. The corresponding multivariate odds ratio (OR) of bladder cancer -- after allowance for age, sex, education, smoking, other urinary infections and high-risk occupations -- was 1.72 (95% confidence interval (CI) 1.0-2.9). The ORs were 0.22 (95% CI 0.1-0.4) for intestinal schistosomiasis and 0.32 (95% CI 0.1-1.9) for schistosomiasis of other types. The OR for urinary schistosomiasis was higher in subjects who were younger at first diagnosis (OR of 3.3 for <15 years) and in those with a long time since first diagnosis (OR of 3.0 for > or = 35 years). The ORs were 15.8 for male ever-smokers with a history of urinary schistosomiasis, compared with never-smokers without such a history, and 3.2 for men ever-infected with urinary Schistosoma haematobium and ever-employed in high-risk occupations, compared with those never-infected and with no high-risk occupational history. This study confirms that clinical history of urinary schistosomiasis is significantly, but modestly, associated with increased bladder cancer risk, explaining some 16% of bladder cancer cases in this Egyptian population
Inhibiting ACK1-mediated phosphorylation of C-terminal Src kinase counteracts prostate cancer immune checkpoint blockade resistance
Solid tumours are highly refractory to immune checkpoint blockade (ICB) therapies due to the functional impairment of effector T cells and their inefficient trafficking to tumours. T-cell activation is negatively regulated by C-terminal Src kinase (CSK); however, the exact mechanism remains unknown. Here we show that the conserved oncogenic tyrosine kinase Activated CDC42 kinase 1 (ACK1) is able to phosphorylate CSK at Tyrosine 18 (pY18), which enhances CSK function, constraining T-cell activation. Mice deficient in the Tnk2 gene encoding Ack1, are characterized by diminished CSK Y18-phosphorylation and spontaneous activation of CD
Pleural fluid residue as a diagnostic tool for cytology-negative malignant pleural effusion: A proof-of-concept study
Pleural fluid residue, or macroscopic tissue, circulating freely in the pleural fluid obtained through direct filtration, may carry diagnostic histopathological information. We aimed to determine the histopathological concordance of pleural fluid residue in diagnosing TPE and MPE, compared with conventional pleural biopsy. This was a prospective cohort study of consecutive inpatients with cytology-negative exudative effusion who underwent pleuroscopy and had their initial suctioned pleural fluid filtered for residue samples. Pleural fluid residue demonstrated malignant cells in four out of seven cases of pleural biopsy-confirmed malignancy. Pleural fluid residue has comparable cytomorphology, but reduced cellularity compared with pleural biopsy. No tuberculous histological features were present in the pleural fluid residue samples. In this preliminary study pleural fluid residue provided histopathological information for malignant pleural effusion, but no incremental diagnostic information for tuberculous effusion. However larger and more definitive studies are required to clarify these findings, and to explore the utility and suitability of pleural fluid residue for mutational analysis
Copper effect on the protein composition of photosystem II
The definitive version is available at:
http://www.blackwell-synergy.com/doi/full/10.1111/j.1399-3054.2000.1100419.xWe provide data from in vitro experiments on the polypeptide composition, photosynthetic electron transport and oxygen evolution activity of intact photosystem II (PSII) preparations under Cu(II) toxicity conditions. Low Cu(II) concentrations (Cu(II) per PSII reaction centre unit≤230) that caused around 50% inhibition of variable chlorophyll a fluorescence and oxygen evolution activity did not affect the polypeptide composition of PSII. However, the extrinsic proteins of 33, 24 and 17 kDa of the oxygen-evolving complex of PSII were removed when samples were treated with 300 μM CuCl2 (Cu(II) per PSII reaction centre unit=1 400). The LHCII antenna complex and D1 protein of the reaction centre of PSII were not affected even at these Cu(II) concentrations. The results indicated that the initial inhibition of the PSII electron transport and oxygen-evolving activity induced by the presence of toxic Cu(II) concentrations occurred before the damage of the oxygen-evolving complex. Indeed, more than 50% inhibition could be achieved in conditions where its protein composition and integrity was apparently preserved.This work was supported by the Dirección General de Investigación Científica y Técnica (Grant PB98-1632).Peer reviewe
Age- and Gender-Related Changes in Contractile Properties of Non-Atrophied EDL Muscle
Background: In humans, ageing causes skeletal muscles to become atrophied, weak, and easily fatigued. In rodent studies, ageing has been associated with significant muscle atrophy and changes in the contractile properties of the muscles. However, it is not entirely clear whether these changes in contractile properties can occur before there is significant atrophy, and whether males and females are affected differently. Methods and Results: We investigated various contractile properties of whole isolated fast-twitch EDL muscles from adult (2–6 months-old) and aged (12–22 months-old) male and female mice. Atrophy was not present in the aged mice. Compared with adult mice, EDL muscles of aged mice had significantly lower specific force, longer tetanus relaxation times, and lower fatiguability. In the properties of absolute force and muscle relaxation times, females were affected by ageing to a greater extent than males. Additionally, EDL muscles from a separate group of male mice were subjected to eccentric contractions of 15 % strain, and larger force deficits were found in aged than in adult mice. Conclusion: Our findings provide further insight into the muscle atrophy, weakness and fatiguability experienced by the elderly. We have shown that even in the absence of muscle atrophy, there are definite alterations in the physiological properties of whole fast-twitch muscle from ageing mice, and for some of these properties the alterations are mor
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