Search

The commercialization of space has resulted in a significant increase in the frequency of spacecraft, which is adding to the already large number of objects in orbit. Therefore, future and present missions are at risk from space debris. Most of these spacecraft in orbit have very limited means of mitigation control systems. As a result, certain international regulations are imposed to obtain a license for a spacecraft for launch purposes. The necessity of a feasible debris mitigation technique enables future space missions to be safe and sustainable. This review sheds light on the drag augmentation devices such as dragsail, which can provide an effective means for accelerating the deorbiting process during the EOL phase, making space safe and sustainable without the risk of space debris. Keywords: Dragsail, Ballistic coefficient, Deorbit duration, Space debris, Low Earth Orbit

The purpose of this study is to investigate the viability of transcatheter aortic valve replacement (TAVR) for severe symptomatic aortic stenosis (AS) in patients with prior chest radiation therapy (cXRT).Since patients with prior cXRT perform poorly with surgical aortic valve replacement, TAVR can be a viable alternative. However, clinical outcomes after TAVR in this patient population have not been well studied.From the pooled registry of the placement of aortic transcatheter valves II trial, we identified patients with and without prior cXRT who underwent TAVR (n = 64 and 3923, respectively). The primary outcome was a composite of all-cause death and any stroke at 2 years. Time to event analyses were shown as Kaplan-Meier event rates and compared by log-rank testing. Hazard ratios (HRs) were estimated and compared by Cox proportional hazards regression model.There was no significant difference in the primary outcome between the patients with and without prior cXRT (30.7% vs. 27.0%; p = 0.75; HR, 1.08; 95% confidence interval, 0.66-1.77). Rates of myocardial infarction, vascular complications, acute kidney injury, or new pacemaker implant after TAVR were not statistically different between the two groups. The rate of immediate reintervention with a second valve for aortic regurgitation after TAVR was higher among the patients with prior cXRT. However, no further difference was observed during 2 years follow-up after discharge from the index-procedure hospitalization.TAVR is a viable alternative for severe symptomatic AS in patients who had cXRT in the past.

In the present study, an attempt was made to find out the Avifaunal diversity in Swamythoopu salt pan, Kanyakumari, Tamil Nadu, India. The study was carried out using point count methods with 14 points during the study period from Jan 2021 to March 2021. 3158 birds belongs to 39 families of 15 avian orders were observed from the study area. Passeriformes alone accounted for 25 species of birds observed during the study period. The migratory status of the birds in Swamythoopu salt pan revealed that most of the birds were resident (67) and the winter migrants were around 20 species. The greater number of individuals was observed at the S5 site with 411 individuals and the lowest was 117 individuals. Spot-billed Pelican Pelecanus philippensisa “Globally threatened” species were recorded in the study area were considered as “Near threatened” species. Anhinga rufa, Threskiornis melanocephalus Mycteria leucocephala, Plegadis falcinellus, Platalea leucorodia were also documented in the study area.

Ant species are ecologically dominant in most terrestrial ecosystems. The present study deals with the diversity of ants at St. Xavier’s College Campus, Palayamkottai, Tamil Nadu, India. Ants were sampled in four different locations from November, 2019 to February, 2020 with the help of different collection methods such as All-out Search Method (AOSM), baits trap (BT), Hand Collection Method (HCM), and Pitfall trap (PT). A total of eight species of ants belonging to three subfamilies-- Pseudomyrmicinae, Myrmicinae and Formicinae were recorded in the study area. Indices of relative abundance and density are commonly used to assess the status of species. The relative abundance of ant species was calculated. The most dominant subfamily was Myrmicinae (4 genera with 4 species), which is followed by Formicinae (2 genera with 3 species). Pseudomyrmicinae was found in small number (one genus with only one species). The relative abundances of subfamilies Oecophylla smaragdina, Tertaponera rufonigra and Solenopsis geminata were 22.7%, 15.95%, 15.6%, respectively. Keywords: Ants survey, Diversity, Distribution, Species abundance, Formicidae, Species diversity

Environmental and physical stressors such as sunlight, atmospheric temperature, photoperiod, and UV radiation have a significant impact on all living organisms in the aquatic ecosystem, particularly on rocky shores, shallow water bodies, lakes, and ponds. In this study, the freshwater fish Punitus bimaculatus (Bleeker) (Cypriniformes: Cyprinidae) was exposed to solar radiation for 1h to 2h duration during the summer season from March to May (water temperature 40 ºC to 42 ºC). The stress caused by increased water temperature (40 oC to 42 oC) significantly reduced the physiological activities and alter the metabolism of the fish, particularly carbohydrate, protein, and lipid levels in the experimental fish, and also damaged the muscle tissue. The muscle carbohydrate, protein and lipid content of Punitus bimaculatus reduced when exposed at 40 ºC and 42 ºC . This could be due to the stress-induced on the fish to utilize the stored energy in the body. Punitus bimaculatus muscle tissue showed marked degeneration of the epithelium, disappearance of striations, and thickened septal wall. The continual degradation of primary metabolites is vital for tissue maintenance but is also important in allowing animals to adapt to changing environmental conditions, replace denatured or damaged proteins, mobilize amino acids, and allow metabolic regulation.

Background Recent advancements in additive manufacturing have made 3D design a desirable skill in combating the historically slow development of biomedical products. Due to the broad applicability of additive manufacturing to biomedical engineering, 3D design and 3D printing are attractive educational tools for biomedical engineering students. However, due to the multidisciplinary nature of biomedical engineering, finding a suitable spot in the curriculum to teach students basic and application-based skills for 3D manufacturing is difficult. Furthermore, prior training in fundamental 3D design skills may be needed to support the use of application-based supplementary content. Results We designed a SolidWorks Simulations toolkit to complement a sophomore (2nd-year)-level Biomechanics course and distributed this assignment to students with and without prior training in 3D design delivered in an introductory biomedical engineering course. Using short videos, example-based problem solving, and step-by-step tutorials, students completed this as an extra-credit assignment and completed a survey gauging student opinion on SolidWorks and 3D design, confidence in each target skill, and the effectiveness of assignment delivery. The compilation of survey responses suggests that the assignment effectively increased positive responses in student opinion on interest in and likeliness to use SolidWorks in both groups. However, confidence in the target assignment skills was higher in the trained group and fewer problems occurred in operating SolidWorks for trained students. Further, analyzing the distribution of student grades with respect to survey responses suggests that responses had no relationship with initial class grade. Conclusion These data collectively indicate that prior training provided to the students had a positive impact on the effectiveness of the assignment although increases in student opinion on the utility of 3D design were observed in both trained and untrained students. Our work has generated and identified a useful educational supplement to enrich existing biomedical engineering course materials with practical skills.

AimsAdditional randomized clinical trial (RCT) data comparing transcatheter aortic valve implantation (TAVI) with surgical aortic valve replacement (SAVR) is available, including longer term follow-up. A meta-analysis comparing TAVI to SAVR was performed. A pragmatic risk classification was applied, partitioning lower-risk and higher-risk patients.Methods and resultsThe main endpoints were death, strokes, and the composite of death or disabling stroke, occurring at 1 year (early) or after 1 year (later). A random-effects meta-analysis was performed. Eight RCTs with 8698 patients were included. In lower-risk patients, at 1 year, the risk of death was lower after TAVI compared with SAVR [relative risk (RR) 0.67; 95% confidence interval (CI) 0.47 to 0.96, P = 0.031], as was death or disabling stroke (RR 0.68; 95% CI 0.50 to 0.92, P = 0.014). There were no differences in strokes. After 1 year, in lower-risk patients, there were no significant differences in all main outcomes. In higher-risk patients, there were no significant differences in main outcomes. New-onset atrial fibrillation, major bleeding, and acute kidney injury occurred less after TAVI; new pacemakers, vascular complications, and paravalvular leak occurred more after TAVI.ConclusionIn lower-risk patients, there was an early mortality reduction with TAVI, but no differences after later follow-up. There was also an early reduction in the composite of death or disabling stroke, with no difference at later follow-up. There were no significant differences for higher-risk patients. Informed therapy decisions may be more dependent on the temporality of events or secondary endpoints than the long-term occurrence of main clinical outcomes.

BackgroundThere are scarce data regarding the post-mitral transcatheter edge-to-edger repair (TEER) course in different racial groups.ObjectiveTo assess the impact of race on outcomes following TEER for mitral regurgitation (MR).MethodsThis is a single-center, retrospective analysis of consecutive TEER procedures performed during 2013–2020. The primary outcome was the composite of all-cause mortality or heart failure (HF) hospitalizations along the first postprocedural year. Secondary outcomes included individual components of the primary outcome, New York Heart Association (NYHA) class, MR grade, and left ventricular mass index (LVMi).ResultsOut of 964 cases, 751 (77.9%), 88 (9.1%), 68 (7.1%), and 57 (5.9%) were whites, blacks, Asians, and Hispanics, respectively. At baseline, non-whites and blacks were younger and more likely be female, based in lower socioeconomic areas, not fully insured, diagnosed with functional MR, and affected by biventricular dysfunction. Intra-procedurally, more devices were implanted in blacks. At 1-year, non-whites (vs. whites) and blacks (vs. non-blacks or whites) experienced higher cumulative incidence of the primary outcome (32.9% vs. 22.5%, p = 0.002 and 38.6% vs. 23.4% or 22.5%, p = 0.002 or p = 0.001, respectively), which were accounted for by hospitalizations in the functional MR sub-cohort (n = 494). NYHA class improved less among blacks with functional MR. MR severity and LVMi equally regressed in all groups. White race (HR 0.62, 95% CI 0.39–0.99, p = 0.047) and black race (HR 2.07, 95% CI 1.28–3.35, p = 0.003) were independently associated with the primary outcome in functional MR patients only.ConclusionMitral TEER patients of different racial backgrounds exhibit major differences in baseline characteristics. Among those with functional MR, non-whites and blacks also experience a less favorable 1-year clinical outcome.

The Gulf of Guinea (GoG) reports high vulnerability to coastal flooding caused by relative or climate-induced sea level rise, which is an example of how coastal sea level changes remain poorly understood, in contrast to the global and regional average sea levels measured by satellite altimetry missions. The relationship between equatorial Atlantic Ocean variability and the 1° coastal band off the coast of the GoG is investigated at interannual time scales from 29 years from recent altimetric products in order to understand its mitigation to sea level rise in a region where there is no reliable tide gauges data. The study focuses on the (extreme) warm and cold events that occur in both the GoG and the Atlantic Ninos and links them to the well-known Benguela Ninos occurrences that occur off the coast of Angola and Namibia. A correlation between signals observed along the GoG with significant events depicted along the Angola-Namibian coastlines as the extraordinary Equatorial Atlantic Warming in 2010, 2012, and 2021 with the 2019 events depicted as the warmest in the last 40 years, which has never been reported in this region, using both altimetric monthly Sea Level Anomalies and Sea Surface Temperature Anomalies. Interannual SLA along the equatorial domain are systematically analyzed, and it is found that they advance the West African coastal ones by 1 month, supporting the idea that equatorial wave dynamics are responsible for their creation and the northward propagation observed on the SLA attributed mainly to the Kelvin coastal trapped waves., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Purpose This paper aims to apply grey wolf optimizer (GWO) algorithm for steady state analysis of self-excited induction generators (SEIGs) supplying isolated loads. Design/methodology/approach Taking the equivalent circuit of SEIG, the impedances representing the stator, rotor and the connected load are reduced to a single loop impedance in terms of the unknown frequency, magnetizing reactance and core loss resistance for the given rotor speed. This loop impedance is taken as the objective function and minimized using GWO to solve for the unknown parameters. By including the value of the desired voltage as a constraint, the formulated objective function is also extended for estimating the required excitation capacitance. Findings The experimental results obtained on a three phase 415 V, 3.5 kW SEIG and the corresponding predetermined performance characteristics agree closely, thereby validating the proposed GWO method. Moreover, a comparative study of GWO with genetic algorithm and particle swarm optimization techniques reveals that GWO exhibits much quicker convergence of the objective function. Originality/value The important contributions of this paper are as follows: for the first time, GWO has been introduced for the SEIG performance predetermination and computation of the excitation capacitance for attaining the desired terminal voltage for the given load and speed; the predicted performance accuracy is improved by considering the variable core loss of the SEIG; and GWO does not require derivations of lengthy equations for calculating the SEIG performance.

Mitochondria are dynamic organelles that differ significantly in their morphologies across cell types, reflecting specific cellular needs and stages in development. Despite the wide biological significance in disease and in health, delineating mitochondrial morphologies in complex systems remains challenging. Here, we present the Mitochondrial Cellular Phenotype (MitoCellPhe) tool developed for quantifying mitochondrial morphologies and demonstrate its utility in delineating differences in mitochondrial morphologies in a human fibroblast and human induced pluripotent stem cell (hiPSC) line. MitoCellPhe generates 24 parameters, allowing for a comprehensive analysis of mitochondrial structures and importantly allows for quantification to be performed on mitochondria in images containing single cells or clusters of cells. With this tool, we were able to validate previous findings that show networks of mitochondria in healthy fibroblast cell lines and a more fragmented morphology in hiPSCs. Using images generated from control and diseased fibroblasts and hiPSCs, we also demonstrate the efficacy of the toolset in delineating differences in morphologies between healthy and the diseased state in both stem cell (hiPSC) and differentiated fibroblast cells. Our results demonstrate that MitoCellPhe enables high-throughput, sensitive, detailed, and quantitative mitochondrial morphological assessment and thus enables better biological insights into mitochondrial dynamics in health and disease.

Scandinavian journal of trauma, resuscitation and emergency medicine 29(1), 113 (2021). doi:10.1186/s13049-021-00930-1, Published by BioMed Central, London

As per WHO, the pneumococcus causes one million fatalities each year because of their underdeveloped immune systems, children are the most vulnerable to pneumococcal infections. The rise of S. pneumoniae resistance to antibiotics is causing widespread alarm all across the globe. Since the last couple of years, a recently developed technique is being used to overcome resistant pathogens. One of these is the computational subtractive genomics technique, in which the bacterial pathogen full proteins are effectively decreased to a limited amount of probable therapeutic targets. The procedures employed in this strategy are to locate human non-homologs targets, proteins that are vital to the illness producing agent, and participation of the identified proteins in pathogen metabolic pathways that are required for bacterial survival. In this work, we applied computational subtractive genomics on the proteins of the S. pneumonia strain D39 and came up with three cytoplasmic proteins that can serve as a promising candidate for novel drug to control the pathogenicity caused by S. pneumoniae.

ImportanceLong-term follow-up after transcatheter aortic valve replacement (TAVR) is of interest given that longitudinal data on mortality and durability of transcatheter heart valves are limited. The REPRISE III (Repositionable Percutaneous Replacement of Stenotic Aortic Valve Through Implantation of Lotus Valve System—Randomized Clinical Evaluation) randomized clinical trial compared the mechanically expanded Lotus valve with the self-expanding CoreValve/EvolutR TAVR platforms.ObjectiveTo describe the final 5-year outcomes of the REPRISE III trial.Design, Setting, and ParticipantsThis prespecified secondary analysis assessed the final 5-year clinical, functional, and echocardiographic outcomes of 912 patients from the REPRISE III trial, which was conducted at 55 centers in North America, Europe, and Australia between September 22, 2014, and December 24, 2015. Patients had high risk for aortic stenosis or severe or symptomatic aortic stenosis. Data were analyzed from September 22, 2014, to May 21, 2021.InterventionLotus valve or CoreValve/EvolutR TAVR platforms.Main Outcomes and MeasuresValve Academic Research Consortium-2 end points, hemodynamic measures, functional status, and health status were examined through the 5-year follow-up.ResultsA total of 912 patients (mean [SD] age, 82.8 [7.3] years; 463 women [50.8%]) were randomized to either the Lotus valve group (n = 607) or CoreValve/EvolutR group (n = 305), with a baseline Society of Thoracic Surgeons risk score of 6.8%. Clinical follow-up data from the REPRISE III trial were available for 581 patients (95.7%) in the Lotus valve group and 285 patients (93.4%) in the CoreValve/EvolutR group. At 5 years, the cumulative event rate for all-cause mortality was 50.9% in the Lotus valve group vs 52.8% in the CoreValve/EvolutR group (P = .59). Disabling stroke was less frequent with the Lotus valve vs CoreValve/EvolutR (cumulative event rates, 8.3% vs 12.2%; P = .04), whereas the cumulative event rates for overall stroke were similar in both groups (14.1% vs 15.3%; P = .38). Insertion of a new permanent pacemaker (38.9% vs 27.3%; P P = .007) were more common in the Lotus valve group than in the CoreValve/EvolutR group. A smaller proportion of patients who received the Lotus valve experienced valve malpositioning (0% vs 2.6%; P P P 2 vs 1.42 [0.42] cm2; P = .10). After 5 years, the proportion of patients with moderate or greater paravalvular leak was not significantly higher with the CoreValve/EvolutR than with the Lotus valve (1.9% vs 0%; P = .31); however, the proportion of patients with mild paravalvular leak was higher in the CoreValve/EvolutR group compared with the Lotus valve group (23.1% vs 7.8%; P = .006). Long-term, similar improvements in New York Heart Association class and Kansas City Cardiomyopathy Questionnaire score were observed in both groups.Conclusions and RelevanceThe REPRISE III trial found that, at 5 years, the clinical outcomes of the Lotus valve were comparable to those of the CoreValve/EvolutR and that the Lotus valve was safe and effective.Trial RegistrationClinicalTrials.gov Identifier: NCT02202434