Active Clustering: Robust and Efficient Hierarchical Clustering using Adaptively Selected Similarities

Hierarchical clustering based on pairwise similarities is a common tool used in a broad range of scientific applications. However, in many problems it may be expensive to obtain or compute similarities between the items to be clustered. This paper investigates the hierarchical clustering of N items based on a small subset of pairwise similarities, significantly less than the complete set of N(N-1)/2 similarities. First, we show that if the intracluster similarities exceed intercluster similarities, then it is possible to correctly determine the hierarchical clustering from as few as 3N log N similarities. We demonstrate this order of magnitude savings in the number of pairwise similarities necessitates sequentially selecting which similarities to obtain in an adaptive fashion, rather than picking them at random. We then propose an active clustering method that is robust to a limited fraction of anomalous similarities, and show how even in the presence of these noisy similarity values we can resolve the hierarchical clustering using only O(N log^2 N) pairwise similarities

Medical students’ evaluation of competency-based and traditionaleducational environment using the Dundee Ready Education Environment Measure

Background:Competency-based medical education (CBME) was introduced in India in 2019 to transform the educational environment. Students’ perspectives are vital to incorporate positive changes and ameliorate shortcomings as important stakeholders. The authors have tried to capture these perceptions in the study. Methods: A cross-sectional study was conducted between August 2020 and May 2021 with randomly selected undergraduate student volunteers at a government medical college in Delhi, India. In all, 50 students were included from the first year enrolled in a competencybased curriculum and 50 from the second year studying a traditional curriculum. The Dundee Ready Education Environment Measure (DREEM) was used to evaluate the perceptions of the educational environments. Results: Perception of learning (PL) showed a more positive response among the first-year students (using CBME) with a mean score of 32.18±6.32 in comparison to the second-year students following the traditional curriculum with a mean score of 29.04±7.29 (P=0.04). Total score, PL, students’ perception of teachers/teaching (PT), and academic self-perception (ASP) (P=0.03,<0.01, 0.02, 0.05 respectively), were higher in day-scholars in comparison to those who stayed in college-based housing (hostellers). Overall, no gender differences were seen. Conclusion: Better PL, a reduction in problem areas, and a favorable environment in day scholars compared to hostellers were all seen in students following the CBME method. Perceptions of the two groups of students concerning support systems and other aspects such as students irritating teachers, cheating, and perceived boredom were different. This analysis of the educational environment can serve as helpful feedback to curriculum designers

Nanocontainers for Self-Healing Coatings on Mild Steel

Mild steel is an important material in construction, automobile, and other engineering applications. Long exposure to a corrosive environment causes damage to the material and makes it less efficient for usage. Various methodologies such as barrier coatings and self-healing coatings are employed to prevent corrosion to occur. To increase the performance of the coatings, modifications are carried out by the addition of corrosion inhibitors into the coating matrix. Direct addition leads to unwanted reactions with the coating matrix and loss of corrosion inhibitor itself. In order to prevent this problem, nanocontainers are used to encapsulate the self-healing agent/corrosion inhibitor. Therefore, recent corrosion prevention methods involve the fabrication of multifunctional coatings using different nanocontainers such as halloysite nanotubes, polymeric microcapsules, layered double hydroxide, etc. loaded with corrosion inhibitors. The release of corrosion inhibitors works on trigger mechanism arising due to change in external stimuli and thus increasing the durability of the coatings

Telescopic Overdenture

Preventive prosthodontics includes procedures that delay or&nbsp;eliminate future prosthodontic problems. Earlier, patients&nbsp;presenting with poor periodontal health, total extraction followed&nbsp;by a complete denture treatment was considered as permanent&nbsp;solution for oral health care but there was no concept of&nbsp;overdentures. Advantages of overdentures are that they prevent&nbsp;residual ridge resorption, provide better stability, retention, good&nbsp;esthetics and proprioception. The aim of this paper is to present&nbsp;a patient with partially edentulous maxillary arch who was&nbsp;rehabilitated with a telescopic overdenture

The New ID Proof: A Case Report of Denture Labeling

Denture labeling is not a new concept in either prosthetic or&nbsp;forensic dentistry and its routine practice has been urged by&nbsp;forensic dentists internationally for many years. Prosthodontistsare playing very important role in forensic dentistry as they are&nbsp;concerned with fabrication of various prostheses which can serve&nbsp;as an important tool for identification. The main objective of this&nbsp;article is to discuss the various methods available for denture&nbsp;marking along with a case report

Network Analysis of Skeletal Muscle During Spaceflight in Male Mice

Context: The unloading associated with spaceflight results in the rapid loss of bone and muscle tissue thereby affecting functionality. These are two of the most concerning physiologic changes that occur in space and could limit long-term occupation in space. Thus, a better understanding of the mechanisms of changes to bone and muscle could lead to development of improved therapies to counteract both spaceflight and terrestrial-based bone and muscle dysfunction.Methods: Here we used a non-biased, stringent, deep sequencing (96 million paired end reads targeting 100 bp read length) assay to examine genomic networks altered by spaceflight in the quadriceps (n=4/group). Specifically, 9 week old C57BL/6 male mice were housed on the International Space Station or at Kennedy Space Center for approximately four weeks (n=10/group). Results: 14,228 genes (70% of whole mouse genome) met the cut-off criteria and the data sets were mapped to an average of ~76% of the whole mouse genome. Of these, 840 genes met the t-test criteria, p\u3c0.05. Canonical networks linked to EIF2 signaling, calcium ion signaling, and oxidative stress response were significantly enriched by the differentially expressed genes. A comprehensive energy deprivation was indicated as functions related to protein synthesis and degradation, lipid synthesis and oxidation, and ATP hydrolysis were inhibited, and mitochondrial dysfunction was activated.Conclusions: This is the first time that skeletal muscle changes have been studied in male mice during spaceflight, and these data add important new findings to changes that occur to the musculoskeletal system in male mice during spaceflight. In orthopaedic trauma, many patients spend prolonged periods non-weight bearing and can experience significant muscle atrophy as a result. The networks analyzed in this work may prove to be targets for future therapies to counter this atrophy

Salmonella in Indian ready-to-cook poultry: antibiotic resistance and molecular characterization

The availability and popularity of processed, ready-to-cook (RTC) poultry products are increasing in India. Though fresh poultry is known to be contaminated with Salmonella, the prevalence of this foodborne pathogen in RTC poultry products is not reported. Eighty-seven chilled and frozen RTC poultry samples of 4 different brands obtained from supermarkets and departmental stores in Mumbai were analyzed for the presence of Salmonella. The prevalence of Salmonella was higher (51%) in chilled RTC samples as compared to the frozen RTC samples (5%). The frozen RTC samples of one brand were free from Salmonella. S. Typhimurium (75.2%) was the most prevalent serovar, followed by S. Enteritidis (23%) and S. Weltevreden (1.7%). A high percentage (81.4%) of the isolates were found to be resistant to 5 or more antibiotics and class 1 integron, which has been shown to confer multi-drug resistance, was detected in 69.9% of the isolates. Multiple antibiotic resistance index of isolates was high (0.6) indicating the indiscriminate use of antibiotics during poultry farming. High genetic diversity was observed among the Salmonella serovars based on Pulsed Field Gel Electrophoresis profiles. Results showed the presence of multi-drug resistant Salmonella serovars in processed, chilled RTC poultry products marketed in Mumbai, India

Analysis of the effects of spaceflight and local administration of thrombopoietin to a femoral defect injury on distal skeletal sites

With increased human presence in space, bone loss and fractures will occur. Thrombopoietin (TPO) is a recently patented bone healing agent. Here, we investigated the systemic effects of TPO on mice subjected to spaceflight and sustaining a bone fracture. Forty, 9-week-old, male, C57BL/6 J were divided into 4 groups: (1) Saline+Earth; (2) TPO + Earth; (3) Saline+Flight; and (4) TPO + Flight (n = 10/group). Saline- and TPO-treated mice underwent a femoral defect surgery, and 20 mice were housed in space ("Flight") and 20 mice on Earth for approximately 4 weeks. With the exception of the calvarium and incisor, positive changes were observed in TPO-treated, spaceflight bones, suggesting TPO may improve osteogenesis in the absence of mechanical loading. Thus, TPO, may serve as a new bone healing agent, and may also improve some skeletal properties of astronauts, which might be extrapolated for patients on Earth with restraint mobilization and/or are incapable of bearing weight on their bones

Meeting Report of the Third Annual Tri-Service Microbiome Consortium Symposium

The Tri-Service Microbiome Consortium (TSMC) was founded to enhance collaboration, coordination, and communication of microbiome research among U.S. Department of Defense (DoD) organizations and to facilitate resource, material and information sharing among consortium members. The 2019 annual symposium was held 22–24 October 2019 at Wright-Patterson Air Force Base in Dayton, OH. Presentations and discussions centered on microbiome-related topics within five broad thematic areas: 1) human microbiomes; 2) transitioning products into Warfighter solutions; 3) environmental microbiomes; 4) engineering microbiomes; and 5) microbiome simulation and characterization. Collectively, the symposium provided an update on the scope of current DoD microbiome research efforts, highlighted innovative research being done in academia and industry that can be leveraged by the DoD, and fostered collaborative opportunities. This report summarizes the presentations and outcomes of the 3rd annual TSMC symposium