Semantic Knowledge Discovery for User Profiling for Location-Based Recommender Systems

This paper introduces a purposed Location-based Recommender System (LBRS) that combines sentiment analysis and topic modelling techniques to improve user profiling for enhancing recommendations of Points of Interest (POIs). Using additional feature extraction, we built user profiles from a Foursquare dataset to evaluate our model and provide recommendations based on user opinions toward venues. Our combined model performed favourably against the baseline models, with an overall improved accuracy of 0.67. The limitations were the use of one dataset and that user profiles were constructed using predicted emotions extracted as features from review data with topic modelling, rather than literal user emotions. Nevertheless, this provides a step forward in user profile and emotion scoring, contributing further to the development of LBRS in the Tourism domain

Evaluating winter precipitation over the western Himalayas in a high-resolution Indian regional reanalysis using multi-source climate datasets

Considerable uncertainties are associated with precipitation characteristics over the western Himalayan region (WHR). These are due to typically small-scale but high intensity storms caused by the complex topography which are under-resolved by a sparse gauge network. Additionally, both satellite and gauge measurements of precipitation remain subject to systematic errors that typically result in underestimation over mountainous terrains. Reanalysis datasets provide a prospective alternative but are limited by their resolution, which has so far been too coarse to properly resolve orographic rainfall. In this study, we evaluate and cross-compare the Indian Monsoon Data Assimilation and Analysis (IMDAA), the first high-resolution (12 km) regional reanalysis over India, against various precipitation products during the winter season over the western Himalayas. We demonstrate the efficiency of IMDAA in representing the characteristics of winter precipitation at seasonal, diurnal and interannual scales, as well as heavy precipitation associated with western disturbances (WDs). IMDAA shows closer agreement to other reanalyses than to gauge-based and satellite products in error and bias analysis. Although depicting higher magnitudes, its fine resolution allows a much closer insight into localized spatial patterns and diurnal cycle, a key advantage over other datasets. Mean winter precipitation over WHR shows a significant decreasing trend in IMDAA, despite no significant trend in the frequency of WDs tracked in either IMDAA or ERA5. The study also exhibits the potential use of IMDAA for characterizing winter atmospheric dynamics, both for climatological studies and during WD activity such as localized valley wind patterns. Overall, these findings highlight the potential utility for IMDAA in carrying out various monitoring and climate change impact assessment studies over the fragile and vulnerable western Himalayan ecosystem

Can strain elastography be used in reclassification of indeterminate breast lesions in BIRADS lexicon?: A prospective study

Purpose: To evaluate the role of strain elastography (SE) in reclassification of indeterminate breast lesions placed under BIRADS 3 and 4 categories by conventional ultrasound (US) parameters so as to recourse biopsy only for suspicious stiffer lesions. Methods: 113 breast lesions in 100 women assigned as BIRADS category 3 and 4 on US parameters were prospectively evaluated by SE followed by histo-pathological examination. Strain ratio (SR) and Elastography Score (ES) were determined for each lesion. The sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated for each modality and diagnostic performance were compared. The best cut-off point was calculated for each of the elastography parameter using the receiver operator curve analysis (ROC). Results: Out of the 113 lesions, 40 were malignant (35.4’) and 73 were benign (64.6’). A statistically significant difference was observed in the AUC for ES and conventional US: 0.98 vs 0.90 (Difference = 0.08, P = 0.02). Elastography parameters were more specific as compared to US (ES-94.5 & SR-93.2’ vs 63’, P < 0.05) with high NPV. SE performed better in BIRADS 4 category lesions. On the basis of elastography parameters, 85’ of BIRADS 4 category lesions were correctly predicted as benign with overall sensitivity, specificity and diagnostic accuracy of elastography being 97’, 84.6’ and 91.9’. Among BIRADS 3 category lesions, 97’ were correctly predicted as benign and 50’ lesions were correctly predicted as malignant with a sensitivity of 50’, specificity of 97.8’ and diagnostic accuracy of 94’. Conclusion: Strain elastography is a useful adjunct to conventional ultrasonography for the assessment of indeterminate breast lesions and may help in avoiding unnecessary follow ups and biopsies. Elastography score is a better parameter as compared to strain ratio

Spondyloarthropathy - Is sacroiliac joint imaging sufficient? A study of 431 patients

Background: Sacroiliac (SI) joint involvement (sacroiliitis) is considered as major criteria for diagnosing Spondyloarthropathy (SpA), although involvement of spine and hip can also occur. The aim of our study was to assess the utility of including sagittal short-tau inversion recovery (STIR) sequence of dorsolumbar spine and coronal STIR/proton density (PD) fat saturated sequence through both hips, to routine SI joint magnetic resonance (MR) imaging protocol, in patients clinically suspected to have SpA. Material and Methods: A retrospective observational study was conducted between February 2013 and February 2018 on clinically suspected SpA patients referred to our department for imaging. The images obtained using this new SI joint protocol were evaluated for findings suggesting SpA diagnosis as per the Assessment of SpondyloArthritis international Society criteria. Other differentials for similar symptoms were also looked for. Results: Of the 431 patients (313 M and 118 F), 255 had features confirming the diagnosis of SpA and 176 had no radiological manifestations of SpA (56 were normal and 120 had other findings to suggest clinical symptoms; e.g., degenerative SpA, Pott’s spine, skeletal metastases, early AVN of hip, cysticercus, iliofemoral impingement). 19/255 patients had normal SI joints but other findings to suggest diagnosis of SpA, e.g. romanus lesions, costovertebritis/costotransversitis, pubic symphysitis, inflammatory hip arthropathy, enthesitis, iliofemoral/trochanteric bursitis. 33/61 patients with chronic sacroiliitis had disease activity in spine or hip. Conclusion: Inclusion of sections through dorsolumbar spine and both hips to routine SI joint protocol, helped in identifying: (a) early disease in 19 patients, who had normal SI joints and may have otherwise been missed with routine only SI joint imaging, (b) additional findings in SpA-related sacroiliitis, (c) disease activity in chronic sacroiliitis, and (d) other causes of low back pain and thus helped in further patient management

Single-Molecule Fluorescence Imaging of DNA Replication Stalling at Sites of Nucleoprotein Complexes

DNA replication in cells occurs on crowded and often damaged template DNA, forming potentially deleterious roadblocks to the progressing replication fork. Numerous tools have been developed to investigate the mechanisms of DNA replication and the fate of stalled replication forks. Here, we describe single-molecule fluorescence imaging methods to visualize processive DNA replication and replication fork stalling at site-specific nucleoprotein complexes. Using dCas9 as a protein barrier and rolling-circle DNA templates, we visualize effective, stable, and site-specific blocking of the Escherichia coli replisome. Additionally, we present a protocol to produce an 18-kb rolling-circle DNA template that provides increased spatial resolution in imaging the interplay between replisomes and roadblocks. These methods can be used to investigate encounters of the replisome with nucleoprotein complexes at the single-molecule level, providing important mechanistic details of replisome stalling and downstream rescue or restart pathways

Insight into Single-Molecule Imaging Techniques for the Study of Prokaryotic Genome Maintenance

Genome maintenance comprises a group of complex and interrelated processes crucial for preserving and safeguarding genetic information within all organisms. Key aspects of genome maintenance involve DNA replication, transcription, recombination, and repair. Improper regulation of these processes could cause genetic changes, potentially leading to antibiotic resistance in bacterial populations. Due to the complexity of these processes, ensemble averaging studies may not provide the level of detail required to capture the full spectrum of molecular behaviors and dynamics of each individual biomolecule. Therefore, researchers have increasingly turned to single-molecule approaches, as these techniques allow for the direct observation and manipulation of individual biomolecules, and offer a level of detail that is unattainable with traditional ensemble methods. In this review, we provide an overview of recent in vitro and in vivo single-molecule imaging approaches employed to study the complex processes involved in prokaryotic genome maintenance. We will first highlight the principles of imaging techniques such as total internal reflection fluorescence microscopy and atomic force microscopy, primarily used for in vitro studies, and highly inclined and laminated optical sheet and super-resolution microscopy, mainly employed in in vivo studies. We then demonstrate how applying these single-molecule techniques has enabled the direct visualization of biological processes such as replication, transcription, DNA repair, and recombination in real time. Finally, we will showcase the results obtained from super-resolution microscopy approaches, which have provided unprecedented insights into the spatial organization of different biomolecules within bacterial organisms

Darier's disease following radiotherapy for carcinoma of cervix

Darier-White disease is due to a defect in the ATP2A2 gene encoding the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase (SERCA2b). We report a case of carcinoma cervix in whom Darier's disease manifested after the initiation of radiation therapy. Conventional cytogenetics on peripheral blood revealed non-clonal constitutional autosomal and X chromosome abnormalities suggesting radiation induced gene toxicity. Occurrence of Darier's disease in our case could be due to treatment induced sustained differentiation in the Darier's affected skin by an unknown mechanism. Late onset or sporadic Darier's disease is the other possibility