A Decentralized Strategy for Swarm Robots to Manage Spatially Distributed Tasks

Large-scale scenarios such as search-and-rescue operations, agriculture, warehouse, surveillance, and construction consist of multiple tasks to be performed at the same time. These tasks have non-trivial spatial distributions. Robot swarms are envisioned to be efficient, robust, and flexible for such applications. We model this system such that each robot can service a single task at a time; each task requires a specific number of robots, which we refer to as \u27quota\u27; task allocation is instantaneous; and tasks do not have inter- dependencies. This work focuses on distributing robots to spatially distributed tasks of known quotas in an efficient manner. Centralized solutions which guarantee optimality in terms of distance travelled by the swarm exist. Although potentially scalable, they require non-trivial coordination; could be computationally expensive; and may have poor response time when the number of robots, tasks and task quotas increase. For a swarm to efficiently complete tasks with a short response time, a decentralized approach provides better parallelism and scalability than a centralized one. In this work, we study the performance of a weight-based approach which is enhanced to include spatial aspects. In our approach, the robots share a common table that reports the task locations and quotas. Each robot, according to its relative position with respect to task locations, modifies weights for each task and randomly chooses a task to serve. Weights increase for tasks that are closer and have high quota as opposed to tasks which are far away and have low quota. Tasks with higher weights have a higher probability of being selected. This results in each robot having its own set of weights for all tasks. We introduce a distance- bias parameter, which determines how sensitive the system is to relative robot-task locations over task quotas. We focus on evaluating the distance covered by the swarm, number of inter- task switches, and time required to completely allocate all tasks and study the performance of our approach in several sets of simulated experiments

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Haemodynamic and clinical variables after surgical systemic to pulmonary artery shunt placement versus arterial ductal stenting

Background: Transcatheter stenting of the arterial duct is an alternative to surgical systemic to pulmonary artery shunt in neonates with parallel circulation. The current study compares haemodynamic and laboratory values in these patients for the first 48 hours after either intervention. Methods: Neonates with ductal dependent pulmonary blood flow who underwent surgical shunt placement or catheter-based arterial ductal stent placement between January 2013 and January 2022 were identified. Haemodynamic variables included heart rate, blood pressure, near infrared spectroscopy, central venous pressure, vasoactive inotropic score, and arterial saturation. Laboratory variables collected included blood urea nitrogen, serum creatinine, and serum lactate. Variables were collected at baseline, upon post-procedural admission, 6 hours after admission, 12 hours after admission, and 48 hours after admission. Secondary outcomes included post-procedural mechanical ventilation duration, post-procedural hospital length of stay, need for reintervention, need for extracorporeal membrane oxygenation, cardiac arrest, and inpatient mortality. Results: Of the 52 patients included, 38 (73%) underwent shunt placement while 14 (27%) underwent a stent placement. Heart rates, renal oxygen extraction ratio, and cerebral oxygen extraction ratio were significantly lower in the stent group (p = \u3c0.01, 0.01, and \u3c 0.01, respectively).Haemoglobin and vasoactive inotropic scores were significantly lower in the stent group (p = \u3c0.01, \u3c0.01, respectively). The stent group had increased risk for cardiac arrest (p = 0.04). Conclusion: Patients who undergo arterial ductal stent placement have lower heart rates, haemoglobin, renal oxygen extraction ratio, cerebral oxygen extraction ratio, and vasoactive inotropic score in the first 48 hours post-procedure compared to patients with shunt placement

Integrated Molecular Characterization of Testicular Germ Cell Tumors

Summary: We studied 137 primary testicular germ cell tumors (TGCTs) using high-dimensional assays of genomic, epigenomic, transcriptomic, and proteomic features. These tumors exhibited high aneuploidy and a paucity of somatic mutations. Somatic mutation of only three genes achieved significance—KIT, KRAS, and NRAS—exclusively in samples with seminoma components. Integrated analyses identified distinct molecular patterns that characterized the major recognized histologic subtypes of TGCT: seminoma, embryonal carcinoma, yolk sac tumor, and teratoma. Striking differences in global DNA methylation and microRNA expression between histology subtypes highlight a likely role of epigenomic processes in determining histologic fates in TGCTs. We also identified a subset of pure seminomas defined by KIT mutations, increased immune infiltration, globally demethylated DNA, and decreased KRAS copy number. We report potential biomarkers for risk stratification, such as miRNA specifically expressed in teratoma, and others with molecular diagnostic potential, such as CpH (CpA/CpC/CpT) methylation identifying embryonal carcinomas. : Shen et al. identify molecular characteristics that classify testicular germ cell tumor types, including a separate subset of seminomas defined by KIT mutations. This provides a set of candidate biomarkers for risk stratification and potential therapeutic targeting. Keywords: The Cancer Genome Atlas, testicular germ cell tumors, seminoma, nonseminoma, DNA methylation, exome sequencing, KIT, copy number, miR-37