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Polytene chromosomes of an Indian Himalayan black fly Simulium (Nevermannia) praelargum (Diptera:Simuliidae)

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Current Zoology 2010年第4期56卷 437-444页

作者： Willie HENRY Subrata Kumar DEY Rakesh varma Sachin THAPA William S PROCUNIER RG. Department of Zoology Darjeeling Government College Darjeeling West Bengal 734101 India School of Biotechnology West Bengal University of TechnologyBF-142 Sector 1Salt Lake City Kolkata 700064 West Bengal India Consultant North Bay Ontario P1B 5W6 Canada

High quality polytene chromosome maps （n=3） of a Himalayan Simuliid Simulium praelargum Datta, 1973 are presented and represent the first cytological description of a taxon found in the feuerborni group, subgenus Nevermannia. Polytene chromosomes one （I） and two （II） are metacentric, chromosome three （III） is submetacentric with the length of each chromosome occupying 37.25 %, 31.36 % and 31.34 % of the total complement length, respectively. Typical simuliid diagnostic intergeneric chromosomal markers are found within the polytene complement of this species. The nucleolar organizer （N.O.） is found at the base of the short arm of chromosome one （IS）, the Ring of Balbiani （R.B.）, double bubble （D.B.） and triad occur in the short arm of chromosome two （IIS）, the Parabalbiani Ring （EB.） and grey band （gb） occur in the long arm of chromosome two （IIL） and the Blister （BL） and Capsule （Ca） occur in the short arm of chromosome three （IIIS）.Terminal bands at the end of IIIS are heterochromatinized and present atypically with respect to other simuliid fauna. Populations studied so far are unique among the Simuliidae in that they exhibit chromosome structural monomorphism. These high resolution polytene chromosome maps will form the basis for future cytological characterization and phylogenetic comparisons amongst members of the feuerborni group

关键词： Black fly Feuerborni group Simulium praelargum Polytene chromosome maps Monomorphism

Superconductivity in the cuprates： Deduction of mechanism for d-wave pairing through analysis of ARPES

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Frontiers of physics 2011年第4期6卷 440-449页

作者： Han-Yong Choi Chandra M. varma Xing-jiang Zhou Department of Physics and Institute for Basic Science Research Sung Kyun Kwan University Suwon 440-746 Korea Department of Physics and Astronomy University of California Riverside California 92521 USA National Laboratory for Superconductivity Institute of Physics Chinese Academy of Sciences Beijing 100190 China

In the Eliashberg integral equations for d-wave superconductivity, two different functions （α2F）n（ω, θ） and （α2F）p,d（ω） determine, respectively, the ＂normal＂ self-energy and the ＂pairing＂ self-energy, w is the frequency of fluctuations scattering the fermions whose momentum is near the Fermi-surface and makes an angle θ to a chosen axis. We present a quantitative analysis of the high-resolution laser based Angle Resolved Photoemission Spectroscopy （ARPES） data on a slightly under doped cuprate compound Bi2212 and use the Eliashberg equations to deduce the w and dependence of （α2F）n（ω, θ） for T just above Tc and below Tc. Besides its detailed w dependence, we find the remarkable result that this function is nearly independent of θ between the （π; π）-direction and 25 degrees from it, except for the dependence of the cut-off energy on 8. Assuming that the same fluctuations determine both the normal and the pairing self-energy, we ask what theories give the function （α2F）p,d（ω） required for the d-wave pairing instability at high temperatures as well as the deduced （α2F）n（θ, w）. We show that the deduced （α2F）n（θ, w） can only be obtained from antiferromagnetic （AFM） fluctuations if their correlation length is smaller than a lattice constant. Using （α2F）p,d（W） consistent with such a correlation length and the symmetry of matrix-elements scatter- ing fermions by AFM fluctuations, we calculate Tc and show that AFM fluctuations are excluded as the pairing mechanism for d-wave superconductivity in cuprates. We also consider the quantumcritical fluctuations derived microscopically as the fluctuations of the observed loop-current order discovered in the under-doped cuprates, and which lead to the marginal Fermi-liquid properties in the normal state. We show that their frequency dependence and the momentum dependence of their matrix-elements to scatter fermions are consistent with the θ and w dependence of the deduced （α2F）n（ω, θ）. The pairing kernel （α2F）p,d（W） calculated using

关键词： high temperature superconductivity mechanisms of superconductivity

Spectral narratives of microstructural restyling and their controls on hydrocarbon generation potential from coal

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International Journal of Coal Science & Technology 2023年第3期10卷 167-189页

作者： Tushar Adsul Santanu Ghosh Anwita Ojha Sudip Bhattacharyya Atul Kumar varma Coal Geology and Organic Petrology Laboratory Department of Applied GeologyIndian Institute of Technology(Indian School of Mines)DhanbadJharkhand 826004India Department of Geology Mizoram UniversityAizawlMizoram 796004India Specialized Coal Petrography Laboratory Natural Energy ResourcesMission II-BGeological Survey of IndiaDK-6Sector-IlSalt Lake CityKolkataWest Bengal 700091India

The low to medium-rank Tertiary coals from Meghalaya,India,are explored for the first time for their comprehensive micro-structural characterization using the FTIR and Raman ***,results from these coals are compared with the Permian medium and high-rank coals to understand the microstructural restyling during coalification and its controls on hydrocarbon *** coal samples are grouped based on the mean random vitrinite reflectance values to record the transformations in spectral attributes with increasing coal *** aliphatic carbon and the apparent aromaticity respond sharply to the first coalification jump(R:0.50%)during low to medium-rank transition and anchizonal metamorphism of the high-rank ***,the Raman band intensity ratio changes during the first coalification jump but remains invari-able in the medium-rank coals and turns subtle again during the onset of pregraphitization in high-rank coals,revealing a polynomial trend with the coal *** Rock-Eval hydrogen index and genetic potential also decline sharply at the first coalification ***,an attempt to comprehend the coal microstructural controls on the hydrocarbon poten-tial reveals that the Tertiary coals comprise highly reactive aliphatic functionalities in the type I-S kerogen,along with the low paleotemperature(74.59-112.28℃)may signify their potential to generate early-mature ***,the presence of type II-II admixed kerogen,a lesser abundance of reactive moieties,and overall moderate paleotemperature(91.93-142.52℃)of the Permian medium-rank coals may imply their mixed hydrocarbon ***,anchizonal metamorphism,polycondensed aromatic microstructure,and high values of paleotemperature(~334.25 to~366.79℃)of the high-rank coals indicate a negligible potential of producing any hydrocarbons.

关键词： Early mature oil generation Meghalaya high-sulfur coal Type II-S kerogen Microstructural ordering Coalification jump Hydrocarbon generation potential

Swarm Optimization and Machine Learning for Android Malware Detection

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Computers, Materials & Continua 2022年第12期73卷 6327-6345页

作者： K.Santosh Jhansi P.Ravi Kiran varma Sujata Chakravarty Centurion University of Technology and Management ParalakhemundiOdishaIndia Maharaj Vijayaram Gajapathi Raj College of Engineering VizianagaramIndia Centurion University of Technology and Management BhubaneswarOdishaIndia

Malware Security Intelligence constitutes the analysis of applications and their associated metadata for possible security *** Programming Interfaces(API)calls contain valuable information that can help with malware *** malware analysis with reduced feature space helps for the efficient identification of *** goal of this research is to find the most informative features of API calls to improve the android malware detection *** swarm optimization methods,viz.,Ant Lion Optimization(ALO),Cuckoo Search Optimization(CSO),and Firefly Optimization(FO)are applied to API calls using auto-encoders for identification of most influential *** nature-inspired wrapperbased algorithms are evaluated using well-known Machine Learning(ML)classifiers such as Linear Regression(LR),Decision Tree(DT),Random Forest(RF),K-Nearest Neighbor(KNN)&SupportVector Machine(SVM).A hybrid Artificial Neuronal Classifier(ANC)is proposed for improving the classification of android *** experimental results yielded an accuracy of 98.87%with just seven features out of hundred API call features,i.e.,a massive 93%of data optimization.

关键词： Android malware API calls auto-encoders ant lion optimization cuckoo search optimization firefly optimization artificial neural networks artificial neuronal classifier

A systematic survey on deep learning and machine learning approaches of fake news detection in the pre-and post-COVID-19 pandemic

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International Journal of Intelligent Computing and Cybernetics 2021年第4期14卷 617-646页

作者： Rajshree varma Yugandhara Verma Priya Vijayvargiya Prathamesh P.Churi Computer Engineering Narsee Monjee Institute of Management and Higher StudiesMumbaiIndia

Purpose-The rapid advancement of technology in online communication and fingertip access to the Internet has resulted in the expedited dissemination of fake news to engage a global audience at a low cost by news channels,freelance reporters and *** the coronavirus disease 2019(COVID-19)pandemic,individuals are inflicted with these false and potentially harmful claims and stories,which may harm the vaccination *** studies reveal that the human ability to detect deception is only slightly better than chance;therefore,there is a growing need for serious consideration for developing automated strategies to combat fake news that traverses these platforms at an alarming *** paper systematically reviews the existing fake news detection technologies by exploring various machine learning and deep learning techniques pre-and post-pandemic,which has never been done before to the best of the authors’***/methodology/approach-The detailed literature review on fake news detection is divided into three major *** authors searched papers no later than 2017 on fake news detection approaches on deep learning andmachine *** paperswere initially searched through theGoogle scholar platform,and they have been scrutinized for *** authors kept“Scopus”and“Web of Science”as quality indexing *** research gaps and available databases,data pre-processing,feature extraction techniques and evaluationmethods for current fake news detection technologies have been explored,illustrating them using tables,charts and ***-The paper is dissected into two approaches,namely machine learning and deep learning,to present a better understanding and a clear ***,the authors present a viewpoint on which approach is better and future research trends,issues and challenges for researchers,given the relevance and urgency of a detailed and thorough analysis of existing *** paper also delves into fake new detec

关键词： Fake news detection Machine learning Deep learning Artificial intelligence Natural language processing COVID-19 Social media Misinformation

Size of atrial septal defect after balloon atrial septostomy does not correlate with immediate improvement in oxygenation

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World Journal of Pediatric Surgery 2021年第1期4卷 21-24页

作者： Kartik Sehgal Kunal Sehgal Suraj varma Monash University MelbourneVictoriaAustralia Monash University ClaytonVictoriaAustralia Monash Heart Monash HealthClaytonVictoriaAustralia

Objective Transposition of great arteries is a common cyanotic heart *** atrial septostomy aims to improve circulatory mixing and *** studies have combined infants with intact ventricular septum and those with ventricular septal ***,the septostomy was performed much later after *** objectives were to ascertain any correlation between the atrial septal defect size and oxygenation,before and after septostomy,as well the change in parameters pre-post *** We performed an audit of the last 10 years of clinical and echocardiographic data(2010-2020)for infants with transposition of great arteries with intact ventricular septum.A pediatric cardiologist,masked to clinical data,reviewed the *** Our study of 25 infants with transposition of great arteries with intact ventricular septum noted that the procedure was performed at a median[interquartile range(IQR)]of 3(2,4)hours after *** was administered to the majority of infants[20/25(80%)].While significant increases in partial pressure of oxygen(24±5 vs 40±6 mmHg,p<0.001)and preductal oxygen saturations(67%±18%vs 81%±11%,p=0.003)were noted,and while the atrial septal defect increased in size from 1.8±0.6 vs 4.8±0.7 mm(p<0.001),no correlation was noted between atrial septal defect size and oxygen *** In our study of infants with transposition of great arteries and intact ventricular septum managed with balloon atrial septostomy,no correlation was noted between the atrial septal defect size and oxygen *** vascular resistance and pulmonary blood flow may be important physiological variables determining oxygenation.

关键词： balloon atrial septal

Can propensity score matching replace randomized controlled trials?

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World Journal of Methodology 2024年第1期14卷 58-70页

作者： Matthias Yi Quan Liau En Qi Toh Shamir Muhamed Surya varma Selvakumar Vishalkumar Girishchandra Shelat Lee Kong Chian School of Medicine Nanyang Technological UniversitySingapore 308232Singapore Department of General Surgery Tan Tock Seng HospitalSingapore 308433Singapore Surgical Science Training Centre Tan Tock Seng HospitalSingapore 308433Singapore

Randomized controlled trials(RCTs)have long been recognized as the gold standard for establishing causal relationships in clinical *** that,various limitations of RCTs prevent its widespread implementation,ranging from the ethicality of withholding potentially-lifesaving treatment from a group to relatively poor external validity due to stringent inclusion criteria,amongst ***,with the introduction of propensity score matching(PSM)as a retrospective statistical tool,new frontiers in establishing causation in clinical research were opened *** predicts treatment effects using observational data from existing sources such as registries or electronic health records,to create a matched sample of participants who received or did not receive the intervention based on their propensity scores,which takes into account characteristics such as age,gender and *** its retrospective nature and its use of observational data from existing sources,PSM circumvents the aforementioned ethical issues faced by *** of RCTs exclude elderly,pregnant women and young children;thus,evidence of therapy efficacy is rarely proven by robust clinical research for this *** the other hand,by matching study patient characteristics to that of the population of interest,including the elderly,pregnant women and young children,PSM allows for generalization of results to the wider population and hence greatly increases the external *** of replacing RCTs with PSM,the synergistic integration of PSM into RCTs stands to provide better research outcomes with both methods complementing each *** example,in an RCT investigating the impact of mannitol on outcomes among participants of the Intensive Blood Pressure Reduction in Acute Cerebral Hemorrhage Trial,the baseline characteristics of comorbidities and current medications between treatment and control arms were significantly different despite the randomization ***,PS

关键词： Propensity score matching Randomized controlled trials Randomization Clinical practice Validity Ethics

Pathophysiology of constipation in the older adult

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World Journal of Gastroenterology 2008年第17期14卷 2631-2638页

作者： G Lindsay McCrea Christine Miaskowski Nancy A Stotts Liz Macera Madhulika G varma Departments of Physiological Nursing University of California Department of Surgery University of California

This review provides information on the definition of constipation, normal continence and defecation and a description of the pathophysiologic mechanisms of constipation. In addition, changes in the anatomy and physiology of the lower gastrointestinal tract associated with aging that may contribute to constipation are described. MEDLINE (1966-2007) and CINAHL (1980-2007) were searched. The following MeSH terms were used: constipation/etiology OR constipation/ physiology OR constipation/physiopathology) AND (age factors OR aged OR older OR 80 and over OR middle age). Constipation is not well defined in the literature. While self-reported constipation increases with age, findings from a limited number of clinical studies that utilized objective measures do not support this association. Dysmotility and pelvic floor dysfunction are important mechanisms associated with constipation. Changes in GI function associated with aging appear to be relatively subtle based on a limited amount of conflicting data. Additional research is warranted on the effects of aging on GI function, as well as on the timing of these changes.

关键词： Constipation Mechanisms Functional consti-pation, Dysmotility, Older adults Pelvic floor dysfunction,Gastrointestinal tract

Forming-Induced Residual Stress and Material Properties of Roll-Formed High-Strength Steels

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Automotive Innovation 2020年第3期3卷 210-220页

作者： Yong Sun VladimirLuzin Yixin Duan Rameshkumar varma Lei Shi Matthias Weiss Institute for Frontier Materials(IFM) Deakin UniversityGeelongVIC3216Australia School of Mechanical and Mining Engineering The University of QueenslandSt LuciaBrisbaneQLD 4072Australia Australian Nuclear Science and Technology Organization(ANSTO) Lucas HeightsNSW2234Australia School of Engineering The University of NewcastleCallaghanNSW2308Australia Research Institute Baoshan Iron&SteelCo.Ltd.Shanghai 201900China

Martensitic steels are widely used in the automotive lightweight application but less understood in aspects of post-forming material *** steels show good ductility in roll forming but occasionally experience delayed(hydrogen)fracture issues,which are believed to be due to the formation of localized residual stress and a reduced product of strength and *** characterize the effect of roll forming process on the formation of residual stress and material properties variation of martensitic steel components,this paper investigates the forming-induced longitudinal residual stress and material property variation in a roll-formed high-strength MS1180 automotive rocker *** finite element analysis results for residual stress are validated by neutron diffraction *** numerical model is used to analyze the full evolution of residual stress during the roll forming process and the effect on material properties with major focus on the product of strength and *** is found that the flower design,in particular the overbending stages,play a significant role in the formation of residual stress and the change in material *** product of strength and elongation is significantly reduced across the profile,in particular in the *** achieved understanding will assist researchers comprehend the material properties of roll-formed component and therefore assist future studies aimed at preventing the occurrence of hydrogen fracture.

关键词： Roll forming Advancedhigh-strengthsteels Martensiticsteels Forming-inducedresidualstress Neutrondiffractionmethod Productofstrengthandelongation