A Distributed Pipeline for Scalable, Deconflicted Formation Flying

Reliance on external localization infrastructure and centralized coordination are main limiting factors for formation flying of vehicles in large numbers and in unprepared environments. While solutions using onboard localization address the dependency on external infrastructure, the associated coordination strategies typically lack collision avoidance and scalability. To address these shortcomings, we present a unified pipeline with onboard localization and a distributed, collision-free motion planning strategy that scales to a large number of vehicles. Since distributed collision avoidance strategies are known to result in gridlock, we also present a decentralized task assignment solution to deconflict vehicles. We experimentally validate our pipeline in simulation and hardware. The results show that our approach for solving the optimization problem associated with motion planning gives solutions within seconds in cases where general purpose solvers fail due to high complexity. In addition, our lightweight assignment strategy leads to successful and quicker formation convergence in 96-100% of all trials, whereas indefinite gridlocks occur without it for 33-50% of trials. By enabling large-scale, deconflicted coordination, this pipeline should help pave the way for anytime, anywhere deployment of aerial swarms.Comment: 8 main pages, 1 additional page, accepted to RA-L and IROS'2

A randomised clinical trial of ultrasound guided cannulation of difficult fistulae for dialysis access

Background: Arteriovenous fistulae (AVF) are preferred for dialysis access but require accurate cannulation for effective dialysis. Evidence supports improvements in cannulation and complication rates using ultrasound guidance (USG) in cannulating other sites. This mixed methods, randomised controlled trial aimed to assess effects of USG during AVF cannulation.Methods: Participants with difficult to cannulate AVF had each cannulation event randomised to USG or standard technique (no USG). The primary outcome was the incidence and number of additional needle passes. Secondary outcomes included: the incidence and number of additional skin punctures; time to achieve two needle cannulation; pain associated with cannulation; local complications. Qualitative outcomes were assessed using patient and staff questionnaires.Results: 32 participants had 346 cannulation events randomised (170 to USG and 176 to standard cannulation). USG resulted in a significant reduction in additional needle passes (72 vs 99 p=0.007) and additional skin punctures (10 vs 25 p=0.016.) but prolonged time to cannulation (p>0.001). There was no difference in pain score (p=0.705) or complications between groups. Questionnaires demonstrated that USG cannulation is acceptable to patients and staff. Conclusion: USG cannulation of AVF is more accurate and no more painful than non-image guided cannulation, but prolonged time to cannulation. Some of the excess time involved may be due to the trial being performed early in cannulating staff’s learning curve with the USG technique. Further work to elucidate which patients gain most benefit from USG cannulation and the effect of USG on cannulation complications and AVF patency is warranted

Extracorporeal Shockwave for Intermittent Claudication and Quality of Life: A Randomized Clinical Trial

Importance Intermittent lower limb claudication limits function and quality of life. Supervised exercise programs are not readily available, and a noninvasive alternative is needed.Objective To assess extracorporeal corporeal shockwave therapy in improving quality of life in patients with claudication.Design, Setting, and Participants In this double-blind, placebo-controlled randomized clinical trial, patients in the outpatient setting at a single tertiary center for vascular surgery were randomized in a 1:1 ratio to extracorporeal shockwave therapy or placebo therapy with no shockwaves delivered. Recruitment was between June 2015 and January 2020, with 12-week follow-up ending in March 2020. A convenience sample of patients with claudication and conservative treatment requirements who refused or were unable to participate in supervised exercise were eligible. Patients receiving anticoagulation therapy or with an active cancer were excluded. Of 522 patients screened, 389 were eligible, 138 were enrolled, and 110 completed follow-up and were included in the primary analysis. Statistical analysis was completed by May 2021.Intervention In the intervention group, patients received 100 impulses of 0.1mJ/mm/cm2 in an area of the gastrocnemius muscle 3 times weekly for 3 weeks. The steps for treatment were replicated for the control group without delivering the treatment.Main Outcomes and Measures The primary outcome was the Physical Functioning domain of the 36-item Short-Form Quality of Life Questionnaire at 12-week follow-up. Secondary outcomes included walking distances, ankle brachial pressure index, and other quality-of-life measures.Results Of 138 patients recruited and randomized, 92 (67%) were male, and the mean (SD) age of the study population was 67 (9.6) years. The intervention group had a significantly higher physical function score at 12 weeks (estimated median difference 3.8; 95% CI, 0.0-7.7; P = .03). However, this significance did not remain when adjusting for covariates. At 12 weeks, the intervention group had significantly longer pain-free and maximum walking distances (pain-free estimated median difference, 34.1, 95% CI, 11.4-56.8; P = .004; maximum estimated median difference, 51.4; 95% CI, 10.7-86.5; P = .01).Conclusions and Relevance To our knowledge, this is the first double-blind, placebo-controlled, randomized clinical trial to consider extracorporeal shockwave therapy for the management of intermittent claudication. It demonstrated efficacy for walking distances, may have a positive effect on quality of life, and may provide a safe, noninvasive alternative therapy for patients with intermittent claudication

A Glimpse at Quasar Host Galaxy Far-UV Emission, Using DLAs as Natural Coronagraphs

In merger-driven models of massive galaxy evolution, the luminous quasar phase is expected to be accompanied by vigorous star formation in quasar host galaxies. In this paper, we use high column density Damped Lyman Alpha (DLA) systems along quasar sight lines as natural coronagraphs to directly study the far-UV (FUV) radiation from the host galaxies of luminous background quasars. We have stacked the spectra of $\sim$2,000 DLA systems (N_HI>10^{20.6} cm^{-2}) with a median absorption redshift = 2.6 selected from quasars observed in the SDSS-III Baryon Oscillation Spectroscopic Survey. We detect residual flux in the dark troughs of the composite DLA spectra. The level of this residual flux significantly exceeds systematic errors in the SDSS fiber sky subtraction; furthermore, the residual flux is strongly correlated with the continuum luminosity of the background quasar, while uncorrelated with DLA column density or metallicity. We conclude that the flux could be associated with the average FUV radiation from the background quasar host galaxies (with medium redshift < z > = 3.1) that is not blocked by the intervening DLA. Assuming all of the detected flux originates from quasar hosts, for the highest quasar luminosity bin (= 2.5x 10^{13} L_sun), the host galaxy has a FUV intensity of 1.5 +/- 0.2 x 10^{40} erg s^{-1} A^{-1}; this corresponds to an unobscured UV star formation rate of 9 M_sun/yr.Comment: 15 pages, 10 figures, Accepted for publication in Ap

A pilot feasibility randomised clinical trial comparing dialkylcarbamoylchloride-coated dressings versus standard care for the primary prevention of surgical site infection

A surgical site infection (SSI) may occur in up to 30% of procedures and results in significant morbidity and mortality. We aimed to assess the feasibility of conducting a randomised controlled trial (RCT) examining the use of dialkylcarbamoylchloride (DACC)-impregnated dressings, which bind bacteria at the wound bed, in the prevention of SSI in primarily closed incisional wounds. This pilot RCT recruited patients undergoing clean or clean-contaminated vascular surgery. Participants were randomised intraoperatively on a 1:1 basis to either a DACC-coated dressing or a control dressing. Outcomes were divided into feasibility and clinical outcomes. The primary clinical outcome was SSI at 30 days (assessed using Centers for Disease Control criteria and Additional treatment, Serous discharge, Erythema, Purulent exudate, Separation of the deep tissues, Isolation of bacteria and duration of inpatient Stay scoring methods). This study recruited 144 patients in 12 months at a median rate of 10 per month. Eligibility was 73% and recruitment 60%. At 30 days, there was a 36.9% relative risk reduction in the DACC-coated arm (16.22% versus 25.71%, odds ratio 0.559, P = 0.161). The number needed to treat was 11 patients. A large-scale RCT is both achievable and desirable given the relative risk reduction shown in this study. Further work is needed to improve the study protocol and involve more centres in a full-scale RCT

A glimpse at quasar host galaxy Far-UV emission using damped Lyα's as natural coronagraphs

In merger-driven models of massive galaxy evolution, the luminous quasar phase is expected to be accompanied by vigorous star formation in quasar host galaxies. In this paper, we use high column density damped Lyα (DLA) systems along quasar sight lines

The Edinburgh claudication questionnaire has poor diagnostic accuracy in people with intermittent claudication

Background The screening and diagnosis of intermittent claudication is a challenging process and often relies on the expertise of specialist vascular clinicians. We sought to investigate the diagnostic performance of the Edinburgh Claudication Questionnaire (ECQ) as a screening tool for referrals of suspected intermittent claudication from primary to secondary care. Method Prospectively, 100 referrals from primary care with a stated diagnosis or query regarding intermittent claudication were recruited. All participants who completed the ECQ, underwent an anklebrachial pressure index (ABPI) assessment and treadmill exercise testing. Outcomes of the ECQ were compared to clinical diagnoses of intermittent claudication. Results The ECQ had a sensitivity of 46.8% (95% CI: 27–65%), specificity of 63.2% (95% CI: 43–82%) and accuracy of 53.0% (95% CI: 43–63%). The diagnostic performance was not changed by combining the ECQ with a positive ABPI or post-exercise ABPI outcome for PAD. Conclusion The ECQ had a poor diagnostic performance in this cohort. Considering the results found here and in other recent studies, the utility of the ECQ as a screening tool and epidemiological survey tool must be questioned. Novel, low-resource diagnostic tools are needed in this population

Seeds morpho-colourimetric analysis as complementary method to molecular characterization of melon diversity

[EN] Melon has undergone an intense process of selection and crossbreeding, resulting in many landraces distributed all over Europe, Africa and Asia. Due to this huge variability, the systematic position of this taxon has been reviewed many times in the last two decades. The goal of this article is to compare the phenotypic characterization achieved by seed features with the molecular analysis on melon genotypes. A set of 124 accessions of Cucurnis melo has been selected for molecular and morpho-colourimetric analyses plus an additional selection of accessions of Cucumis sativus, Citrullus lanatus and Citrullus colocynthis used to highlight seed morphology distances among genus and species. Genotyping was performed on the basis of 211 polymorphic SNPs and was executed using the iPLEX (R) Gold MassARRAY Sequenom technology. A total of 137 parameters were specifically designed to evaluate seed colour, size, shape and texture. Both molecular and seed morpho-colourimetrical analyses confirm the existence of two melon subspecies while an intermediate group has also been found. A non random allelic distribution in SNPs located in specific genomic regions suggests that some of these regions may account for a part of the observed variation in seed size. Six major groups of varieties can be discriminated on the basis on seed traits. (C) 2015 Elsevier B.V. All rights reserved.The Italian University and Research Ministry (MIUR) financed the Ph.D. scholarship (Diego Sabato, Univeristy of Cagliari), making this research possible. Molecular analysis was carried out with contributions of the PLANT KKBE project PIM2010PKB-00691 and the complementary grant from the Generalitat Valenciana ACOMP/2013/141.Sabato, D.; Esteras Gómez, C.; Grillo, O.; Picó Sirvent, MB.; Bacchetta, G. (2015). Seeds morpho-colourimetric analysis as complementary method to molecular characterization of melon diversity. Scientia Horticulturae. 192:441-452. https://doi.org/10.1016/j.scienta.2015.06.006S44145219

MRI of Auto-Transplantation of Bone Marrow-Derived Stem-Progenitor Cells for Potential Repair of Injured Arteries

This study was to validate the feasibility of using clinical 3.0T MRI to monitor the migration of autotransplanted bone marrow (BM)-derived stem-progenitor cells (SPC) to the injured arteries of near-human sized swine for potential cell-based arterial repair.The study was divided into two phases. For in vitro evaluation, BM cells were extracted from the iliac crests of 13 domestic pigs and then labeled with a T2 contrast agent, Feridex, and/or a fluorescent tissue marker, PKH26. The viability, the proliferation efficiency and the efficacies of Feridex and/or PKH26 labeling were determined. For in vivo validation, the 13 pigs underwent endovascular balloon-mediated intimal damages of the iliofemoral arteries. The labeled or un-labeled BM cells were autotransplanted back to the same pig from which the BM cells were extracted. Approximately three weeks post-cell transplantation, 3.0T T2-weighted MRI was performed to detect Feridex-created signal voids of the transplanted BM cells in the injured iliofemoral arteries, which was confirmed by subsequent histologic correlation.Of the in vitro study, the viability of dual-labeled BM cells was 95-98%. The proliferation efficiencies of dual-labeled BM cells were not significantly different compared to those of non-labeled cells. The efficacies of Feridex- and PKH26 labeling were 90% and 100%, respectively. Of the in vivo study, 3.0T MRI detected the auto-transplanted BM cells migrated to the injured arteries, which was confirmed by histologic examinations.This study demonstrates the capability of using clinical 3.0T MRI to monitor the auto-transplantation of BM cells that migrate to the injured arteries of large animals, which may provide a useful MRI technique to monitor cell-based arterial repair

Helios Expression Is a Marker of T Cell Activation and Proliferation

Foxp3+ T-regulatory cells (Tregs) normally serve to attenuate immune responses and are key to maintenance of immune homeostasis. Over the past decade, Treg cells have become a major focus of research for many groups, and various functional subsets have been characterized. Recently, the Ikaros family member, Helios, was reported as a marker to discriminate naturally occurring, thymic-derived Tregs from those peripherally induced from naïve CD4+ T cells. We investigated Helios expression in murine and human T cells under resting or activating conditions, using well-characterized molecules of naïve/effector/memory phenotypes, as well as a set of Treg-associated markers. We found that Helios-negative T cells are enriched for naïve T cell phenotypes and vice versa. Moreover, Helios can be induced during T cell activation and proliferation, but regresses in the same cells under resting conditions. We demonstrated comparable findings using human and murine CD4+Foxp3+ Tregs, as well as in CD4+ and CD8+ T cells. Since Helios expression is associated with T cell activation and cellular division, regardless of the cell subset involved, it does not appear suitable as a marker to distinguish natural and induced Treg cells