DCP-SLAM: Distributed Collaborative Partial Swarm SLAM for Efficient Navigation of Autonomous Robots.

Collaborative robots represent an evolution in the field of swarm robotics that is pervasive in modern industrial undertakings from manufacturing to exploration. Though there has been much work on path planning for autonomous robots employing floor plans, energy-efficient navigation of autonomous robots in unknown environments is gaining traction. This work presents a novel methodology of low-overhead collaborative sensing, run-time mapping and localization, and navigation for robot swarms. The aim is to optimize energy consumption for the swarm as a whole rather than individual robots. An energy- and information-aware management algorithm is proposed to optimize the time and energy required for a swarm of autonomous robots to move from a launch area to the predefined destination. This is achieved by modifying the classical Partial Swarm SLAM technique, whereby sections of objects discovered by different members of the swarm are stitched together and broadcast to members of the swarm. Thus, a follower can find the shortest path to the destination while avoiding even far away obstacles in an efficient manner. The proposed algorithm reduces the energy consumption of the swarm as a whole due to the fact that the leading robots sense and discover respective optimal paths and share their discoveries with the followers. The simulation results show that the robots effectively re-optimized the previous solution while sharing necessary information within the swarm. Furthermore, the efficiency of the proposed scheme is shown via comparative results, i.e., reducing traveling distance by 13% for individual robots and up to 11% for the swarm as a whole in the performed experiments.

Swarm formation morphing for congestion-aware collision avoidance.

The focus of this work is to present a novel methodology for optimal distribution of a swarm formation on either side of an obstacle, when evading the obstacle, to avoid overpopulation on the sides to reduce the agents' waiting delays, resulting in a reduced overall mission time and lower energy consumption. To handle this, the problem is divided into two main parts: 1) the disturbance phase: how to morph the formation optimally to avoid the obstacle in the least possible time in the situation at hand, and 2) the convergence phase: how to optimally resume the intended formation shape once the threat of potential collision has been eliminated. For the first problem, we develop a methodology which tests different formation morphing combinations and finds the optimal one, by utilizing trajectory, velocity, and coordinate information, to bypass the obstacle. For the second problem, we utilize thin-plate splines (TPS) inspired temperature function minimization method to bring the agents back from the distorted formation into the desired formation in an optimal manner, after collision avoidance has been successfully performed. Experimental results show that, in the considered test scenario, the proposed approach results in substantial energy savings as compared with the traditional methods.

Sex differences in the mortality rate for coronavirus disease 2019 compared to other causes of death.

Men are more likely than women to die due to coronavirus disease 2019 (COVID-19). This paper sets out to examine whether the magnitude of the sex differences in the COVID-19 mortality rate are unusual when compared to other common causes of death. In doing so, we aim to provide evidence as to whether the causal pathways for the sex differences in the mortality rate of COVID-19 likely differ from those for other causes of death. We found that sex differences in the age-standardized COVID-19 mortality rate were substantially larger than for the age-standardized all-cause mortality rate and most other common causes of death. These differences were especially large in the oldest age groups. ONE SENTENCE SUMMARY: The sex difference in the mortality rate of coronavirus disease 2019 is substantially larger than for other common causes of death.

Perioperative impact of sleep apnea in a high-volume specialty practice with a strong focus on regional anesthesia: a database analysis.

BACKGROUND AND OBJECTIVES: Obstructive sleep apnea (OSA) is a risk factor for adverse postoperative outcome and perioperative professional societies recommend the use of regional anesthesia to minimize perioperative detriment. We studied the impact of OSA on postoperative complications in a high-volume orthopedic surgery practice, with a strong focus on regional anesthesia. METHODS: After Institutional Review Board approval, 41 766 cases of primary total hip and knee arthroplasties (THAs/TKAs) from 2005 to 2014 were extracted from institutional data of the Hospital for Special Surgery (approximately 5000 THAs and 5000 TKAs annually, of which around 90% under neuraxial anesthesia).The main effect was OSA (identified by the International Classification of Diseases, ninth revision codes); outcomes of interest were cardiac, pulmonary, gastrointestinal, renal/genitourinary, thromboembolic complications, delirium, and prolonged length of stay (LOS). Multivariable logistic regression models provided ORs, corresponding 95% CIs, and p values. RESULTS: Overall, OSA was seen in 6.3% (n=1332) of patients with THA and 9.1% (n=1896) of patients with TKA. After adjustment for relevant covariates, OSA was significantly associated with 87% (OR 1.87, 95% CI 1.51 to 2.30), 52% (OR 1.52, 95% CI 1.13 to 2.04), and 44% (OR 1.44,95% CI 1.31 to 1.57) increased odds for pulmonary gastrointestinal complications, and prolonged LOS, respectively. The odds for other outcomes remained unaltered by OSA diagnosis. CONCLUSION: We showed that, even in a setting with almost universal regional anesthesia use, OSA was associated with increased odds for prolonged LOS, and pulmonary and gastrointestinal complications. This puts forward the question of how effective regional anesthesia is in mitigating postoperative complications in patients with OSA.

Surveilling the Potential for Precision Medicine-driven PD-1/PD-L1-targeted Therapy in HNSCC.

Immunotherapy is becoming an accepted treatment modality for many patients with cancer and is now approved for use in platinum-refractory recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). Despite these successes, a minority of patients with HNSCC receiving immunotherapy respond to treatment, and few undergo a complete response. Thus, there is a critical need to identify mechanisms regulating immune checkpoints in HNSCC such that one can predict who will benefit, and so novel combination strategies can be developed for non-responders. Here, we review the immunotherapy and molecular genetics literature to describe what is known about immune checkpoints in common genetic subsets of HNSCC. We highlight several highly recurrent genetic lesions that may serve as biomarkers or targets for combination immunotherapy in HNSCC.

Body weight lower limits of fetal postmortem MRI at 1.5 T.

OBJECTIVE: To evaluate the diagnostic yield of postmortem magnetic resonance imaging (PM-MRI) compared with conventional autopsy in fetuses of early gestational age and low body weight. METHODS: Fetuses of < 31 weeks' gestation that underwent 1.5-T PM-MRI and conventional autopsy were included. The findings of PM-MRI and conventional autopsy were reported blinded to each other. The reports of conventional autopsy and PM-MRI for each organ system (cardiovascular, neurological, abdominal, non-cardiac thoracic and musculoskeletal) were classified as either diagnostic or non-diagnostic. The likelihood of a non-diagnostic examination by PM-MRI was calculated according to fetal gestational age and body weight. RESULTS: Full datasets were examined of 204 fetuses, with mean gestational age of 20.95 ± 3.82 weeks (range, 12.0-30.7 weeks) and body-weight range of 15.9-1872 g. Body weight was the most significant predictor of diagnostic yield of PM-MRI. There was 95% confidence that 90% of fetuses will show diagnostic images by PM-MRI for all five organ systems when fetal body weight is ≥ 535 g, but < 50% of fetuses will have all five systems diagnostic on PM-MRI when body weight is < 122 g. CONCLUSION: PM-MRI is highly likely to provide adequate diagnostic images for fetuses with a body weight > 500 g. Below this weight, the diagnostic yield of standard 1.5-T PM-MRI decreases significantly. These data should help inform parents and clinicians on the suitability of performing PM-MRI in fetuses with low body weight. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Increased uptake on 99mTc bone scintigraphy in a case of tumoral calcinosis in a child.

Tumoral calcinosis is an idiopathic condition resulting in the periarticular deposition of calcium crystals and salts in soft tissues. It is rare in children, and even rarer in idiopathic form. We present a case of a 2-year-old female with tumoral calcinosis in the supraclavicular region, and, in particular, focus on the pertinent radiological findings with radiography, MRI and bone scintigraphy.

Hyperbaric oxygen and dental extractions in irradiated patients: short- and long-term outcomes.

PURPOSE: Mandibular osteoradionecrosis (ORN) can occur in patients post-radiation therapy. This study assessed the incidence of ORN in the setting of adjunctive hyperbaric oxygen therapy (HBO2) and sought to identify risk factors that may predispose to its development. METHODS: A retrospective chart review was completed on patients with a history of radiation therapy to the head and neck who underwent HBO2 prior to and immediately following dental extractions between January 1, 1995, and December 31, 2005, in the hyperbaric medicine unit. RESULTS: The incidence of ORN in 40 patients immediately following completion of HBO was 0%. Available follow-up longer than six months after completion of HBO2 on 19 of these patients showed an incidence of ORN increased to 15.8%. None of the considered risk factors for development of ORN reach statistical significance. CONCLUSION: The incidence of ORN at the completion of HBO2 was less than previously reported incidences between 1.5%-4.2%. However, long-term follow-up indicated a much higher incidence of 15.8%. The difference in incidence of ORN immediately upon completion of HBO2 approximately two weeks after dental extractions compared to that at least six months later identifies a need for more long-term follow-up of these patients following their dental extractions.

Flow cytometric analysis of different adhesion molecules expression on circulating CD14- and CD64- human dendritic cell precursors.

Blood dendritic cell precursors (DCps) are identified as mononuclear leukocytes expressing HLA-DR but lacking the characteristic antigens associated with T cells (CD3), NK cells (CD16 and CD56) and B cells (CD 19). Dendritic cell precursors are distinguished from monocytes by their lack of expression of CD64 rather than of CD14. This study investigated whether CD14- DCps differed from CD64-DCps, which were predominantly CD14+, in their expression of five well-characterised adhesion molecules. There were significantly fewer cells expressing CD11b, CD18 and CD29 in the CD64-DCp population compared with CD14- DCps, and this CD64- DCp subpopulation also had a lower expression of CD11b and CD18. Our results suggest that the two DC precursor subpopulations may differ from one another in their binding characteristics to blood vessel walls and to other leukocytes.

Treatment of children with steroid refractory idiopathic nephrotic syndrome: the Kuwaiti experience.

Data on the treatment and outcome of Kuwaiti children with steroid refractory idiopathic glomerulonephritis (SRIGN), i.e. nephrotic syndrome who failed an eight-week course of prednisone, were collected retrospectively from the records of children attending the two renal centers of Kuwait between January 1, 1990 to December 31, 1996. During those seven years, a total of 34 Kuwaiti children were diagnosed to have SRIGN. Histologically, 22 (65%) of those patients had minimal change, 5 (15%) focal segmental GN, 2 (6%) non-IgA mesangioproliferative GN and one membranous GN. Twenty-two patients had manifested frequent relapses, six were steroid-dependent and six were steroid-resistant. Treatment options were in the following order: (a) small maintenance-dose of corticosteroids (< 0.5 mg/kg/alternate days); (b) cyclophosphamide and or chlorambucil for a single eight week-course or eight then 12 week courses (c) cyclosporin A for three months. The response to therapy was as follows: nine children were cured with low-dose corticosteroids; 17 with chlorambucil and/or cyclophosphamide; and five with cyclosporin A. At the end of study, only three children failed such drug therapy, two of who had focal segmental glomerulosclerosis.

Kawasaki disease: clustering in infants and pre-school children in Kuwait.

We report five children who presented within a 2-month period and who all fulfilled at least four of the five criteria essential for the diagnosis of Kawasaki disease. They were three girls and two boys aged between 5 months and 3 years. Two of them had atypical presentations; one mimicked infectious mononucleosis and the other had severe abdominal pain and was later found to have hydrops of the gall bladder. Although treatment was started within the 1st 10 days of the illness, echocardiographic changes were found in three cases: one had myocarditis and the other two showed in the coronary arteries. The occurrence of five cases in such as short period of time is similar to the clusterings of Kawasaki disease reported in Japan and the USA, and strongly suggests the presence of a causative infectious agent.

The effect of artificial photoperiod at the end of the breeding season on plasma testosterone concentrations in stallions.

Testosterone concentrations in stallions showed a seasonal trend with peak concentrations in the spring (April and May in Britain) and lowest concentrations in the period from December to February. The effect on this pattern of changing the length of the photoperiod at the end of the normal breeding season (mid-summer's day) was studied in 2 experiments. In the first experiment artificial illumination was organised from 21 June to mimic the effect of transfer to a southern hemisphere spring and summer, that is short days becoming longer. The stallions had low concentrations of testosterone in February and high concentrations in April. Concentrations in July, August and September were extremely low with a return to high values in late November/early December. In the second experiment, illumination was maintained at the equivalent of a 16 1/2-hour day from 21 June to mid December. These stallions had high testosterone concentrations in April, after which they fell until August, later rising to a maximum in October. These results are discussed in relation to transfer of stallions between the northern and southern hemispheres.

Adrenal-testis interaction in the stallion.

The authors describe the short and long term effects of synthetic adrenocorticotrophin and of cortisol on peripheral plasma testosterone concentrations in 2 stallions. A single injection of either hormone temporarily raised plasma testosterone concentrations but repeated injection (twice daily for 5 days) depressed plasma testosterone concentrations. Cessation of treatment was followed by a rise in plasma testosterone to concentrations higher than those in the pretreatment period. These findings are briefly discussed.