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Phytoplankton abundance and community structure in the Antarctic polar frontal region during austral summer of 2009

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Chinese Journal of Oceanology and Limnology 2013年第1期31卷 21-30页

作者： SHRAMIK Patil rahul mohan SUHAS Shetye SAHINA Gazi National Centre for Antarctic and Ocean Research

The Antarctic polar front region in the Southern Ocean is known to be most productive. We studied the phytoplankton community structure in the Indian sector at this frontal location during late austral summer (February, 2009) onboard R/V Akademic Boris Petrov. We used the phytoplankton and microheterotrophs abundance, as also the associated physico-chemical parameters to explain the low phytoplankton abundance in the study region. This study emphasizes the shift of phytoplankton, from large (>10 μm) to small (10 μm) phytoplankton abundance during the late austral summer. This study highlights the highly productive polar front nevertheless becomes a region of low phytoplankton abundance, due to community shifts towards pico-phytoplankton (<10 μm) during late austral summer.

关键词： Southern Ocean polar front diatom ciliate dinoflagellate

Contrasting Productivity and Redox Potential in Arabian Sea and Bay of Bengal

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Journal of Earth Science 2014年第2期25卷 366-370页

作者： Suhas S Shetye Maruthadu Sudhakar rahul mohan Babula Jena National Centre for Antarctic & Ocean Research Ministry of Earth Sciences

Understanding the past and present changes is critical for evaluating the future climatic changes. In order to understand the paleoproductivity and depositional environments of Northern In- dian Ocean, two sediment cores were collected, one each from the Arabian Sea （lat. 16°51.40′N and long. 71°54.37′E, water depth 803 m） and the Bay of Bengal （lat. 13°05.35′N and long. 91°28.21′E, wa- ter depth 3 054 m）. The surface seawater samples indicate higherpCO2 values in Arabian Sea as com- pared to the Bay of Bengal. The sediment organic carbon variations along with sedimentological and other geochemical parameters were studied. Sediment organic carbon varied from 0.5%--4.7% and 0.3%-1.22% in Arabian Sea and the Bay of Bengal, respectively. In Arabian Sea, low productivity, oxic conditions and less intense southwest monsoon prevailed during the deglacial period, whereas productivity has increased from last 16 kyr to the modern age. In the Bay of Bengal, organic carbon decreased from the Last Glacial Maxima （LGM） to the modern age, indicating higher productivity in the past as compared to modern age. Fe was associated with organic carbon in the Bay of Bengal and increased during LGM, showing similar trend to that of organic carbon, indicating that Fe may be the limiting factor for the growth of phytoplankton in the Bay of Bengal in the modern age. In the Bay of Bengal, Mn is enriched during modern age and is depleted during LGM, whereas chromium showed the opposite trend indicating anoxic conditions during the LGM, whereas in Arabian Sea the trends are opposite to the Bay of Bengal.

关键词： paleoproductivity geochemical deglacial organic carbon.

Secondary Calcification of Planktic Foraminifera from the Indian Sector of Southern Ocean

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Acta Geologica Sinica(English Edition) 2015年第1期89卷 27-37页

作者： rahul mohan Suhas S.SHETYE Manish TIWARI Narayanpillai ANILKUMAR National Centre for Antarctic and Ocean Research National Institute of Oceanography

This study focused on planktic foraminifera in plankton tows and surface sediments from the western Indian sector of Southern Ocean in order to evaluate the potential foraminiferal secondary calcification and/or dissolution in the sediment. It is found that the symbiotic foraminiferal species are abundant in the subtropical region, whereas non-symbiotic species dominate in the sub-Antarctic and polar frontal regions. The distribution of the symbiotic and non-symbiotic foraminiferal species is controlled by temperature, salinity, light, nutrients and phytoplankton biomass. There is also a lateral southern extent in abundance of planktic foraminifera from surface sediments to plankton tows. The shell weights of the planktic foraminifera N. pachyderma, G. bulloides and G. ruber within the surface sediments are on an average heavier by 27%, 34% and 40% respectively than shells of the same size within the plankton tows, indicative of secondary calcification. The planktic foraminiferal isotopes show the presence of heavier isotopes in the surface sediment foraminifera as compared to plankton tows, thus confirming secondary calcification. Secondary calcification in G. ruber occurs in the euphotic zone, whereas in case of N. pachyderma and G. builoides it is at deeper depths. We also observed a decrease in the shell spines in surface sediment foraminifera as compared to plankton tows, indicative of the morphological changes that foraminifera underwent during gametogenesis.

关键词： Southern Ocean foraminifera climate change stable isotopes shell weight

Variability of Nonionellina labradorica Dawson in Surface Sediments from Kongsfjorden,West Spitsbergen

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Acta Geologica Sinica(English Edition) 2011年第3期85卷 549-558页

作者： Suhas SHETYE rahul mohan Sunil Kumar SHUKLA Sudhakar MARUTHADU Rasik RAVINDRA National Centre for Antarctic and Ocean Research Goa India Ministry of Earth Sciences New Delhi India

Kongsfjorden is a fjord in Spitsbergen（Svalbard archipelago）that lies adjacent to both Arctic and Atlantic water masses and is therefore a suitable site to understand the effects of climate change on *** decipher the effect of the lateral advection of transformed Atlantic water （TAW）within the fjord,spatial variations of foraminiferal tests,their test size variations and stable isotopic composition（δ^（13）C andδ^（18）O）in the surface sediments were *** organic carbon and textural analyses were also carried *** dominant benthic foraminifera included Nonionellina labradorica,Elphidium excavatum,Cassidulina reniforme,Quinqueloculina stalkeri and Islandiella *** labradorica was the predominant species in the outer fjord,whereas Elphidium excavatum and Cassidulina reniforme were dominant in the inner *** organic carbon and the test size of Nonionellina labradorica within the fjord were highly correlated（r=0.97）and both showed a decreasing trend towards the inner *** on the distribution and abundance of Nonionellina labradorica as well as temperature profiles,we suggest that there was little or no major change in the lateral advection of TAW within the fjord in the immediate past.

关键词： West Spitsbergen Current Kongsfjorden Nonionellina labradorica grain size organic carbon stable isotopes temperature

EXECUTER2 modulates the EXECUTER1 signalosome through its singlet oxygen-dependent oxidation

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Molecular Plant 2022年第3期15卷 438-453页

作者： Vivek Dogra rahul mohan Singh Mengping Li Mingyue Li Somesh Singh Chanhong Kim Shanghai Center for Plant Stress Biology CAS Center for Excellence in Molecular Plant SciencesChinese Academy of SciencesShanghai 200032China University of the Chinese Academy of Sciences Beijing 100049China Present address:Biotechnology Division CSIR-Institute of Himalayan Bioresource TechnologyPalampur 176061India

Oxidative post-translational modifications of specific chloroplast proteins contribute to the initiation of retrograde *** Arabidopsis thaliana EXECUTER1(EX1)protein,a chloroplast-localized singlet oxygen(^(1)O_(2))sensor,undergoes tryptophan(Trp)643 oxidation by^(1)O_(2),a chloroplast-derived and light-dependent reactive oxygen *** indole side chain of Trp is vulnerable to^(1)O_(2),leading to the generation of oxidized Trp variants and priming EX1 for degradation by a membrane-bound FtsH *** perception of^(1)O_(2)via Trp643 oxidation and subsequent EX1 proteolysis facilitate chloroplast-to-nucleus retrograde *** this study,we discovered that the EX1-like protein EX2 also undergoes^(1)O_(2)-dependent Trp530 oxidation and FtsH-dependent turnover,which attenuates^(1)O_(2)signaling by decelerating EX1-Trp643 oxidation and subsequent EX1 *** with this finding,the loss of EX2 function reinforces EX1-dependent retrograde signaling by accelerating EX1-Trp643 oxidation and subsequent EX1 proteolysis,whereas overexpression of EX2 produces molecular phenotypes opposite to those observed in the loss-of-function mutants of ***,phylogenetic analysis suggests that EX2 may have emerged evolutionarily to attenuate the sensitivity of EX1 toward^(1)O_(2).Collectively,these results suggest that EX2 functions as a negative regulator of the EX1 signalosome through its own^(1)O_(2)-dependent oxidation,providing a new mechanistic insight into the regulation of EX1-mediated^(1)O_(2)signaling.

关键词： EXECUTER1 EXECUTER2 singlet oxygen retrograde signaling Trp oxidation FtsH protease

Enhancement of Solar PV Panel Efficiency Using Double Integral Sliding Mode MPPT Control

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Tsinghua Science and Technology 2024年第1期29卷 271-283页

作者： Immadisetty rahul Raju Hariharan Department of Electrical and Electronics Engineering Saveetha School of EngineeringSaveetha Institute of Medical and Technical Sciences(SIMATS)Chennai 602105India

The extraction of maximum power from the solar panels,using the sliding mode control scheme,becomes popular for partial weather atmospheric conditions due to its effective dynamic duty cycle ***,the sliding mode control scheme was sophisticated with single integral and double integral sliding mode control scheme,which offer enhanced maximum power extraction and support enhanced solar panel efficiency in partial weather *** operation of the sliding mode control scheme depends on the selection of a sliding surface selection based on the atmospheric weather condition,which enables the effective sliding duty cycle ratio operation for the DC/DC boost *** duty cycle ratio of the sliding mode control resembles the usual dynamic behavior to achieve enhanced efficiency compared to the various maximum power point tracking(MPPT)*** major limitation of the sliding mode control scheme is to achieve the steady state voltage error of the solar panel in minimum settling time *** single integral sliding mode control scheme achieves the expected steady state voltage error limit but fails to achieve minimum settling time ***,the single integral sliding mode control is extended to a double integral sliding mode control scheme to achieve both steady state voltage error limits within the minimum settling time *** double integral sliding mode control scheme allows us to obtain the higher sliding surface duty cycle ratio which acts as the input signal to the boost *** activates the enhanced stable and reliable system operation,and nullifies the lacuna of maximum solar panel efficiency under partial weather ***,this paper aims to present the design and performance operation of the double integral sliding mode(DISM)MPPT control *** validate the performance analysis of the proposed DISM MPPT control scheme,the MATLAB/Simulink model is designed and ***,the performance analysis of the pr

关键词： maximum power point tracking(MPPT)schemes sliding mode controller(SMC) double integral sliding mode controller(DISMC) pulse width modulation(PWM) photovoltaic(PV)system

Maximum correntropy-based pseudolinear Kalman filter for passive bearings-only target tracking

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Control Theory and Technology 2024年第2期22卷 269-281页

作者： Asfia Urooj rahul Radhakrishnan Department of Electrical Engineering SVNITSuratGujarat395007India Department of Electrical Engineering NIT CalicutKozhikodeKerala673601India

This paper proposes a new approach for solving the bearings-only target tracking (BoT) problem by introducing a maximum correntropy criterion to the pseudolinear Kalman filter (PLKF). PLKF has been a popular choice for solving BoT problems owing to the reduced computational complexity. However, the coupling between the measurement vector and pseudolinear noise causes bias in PLKF. To address this issue, a bias-compensated PLKF (BC-PLKF) under the assumption of Gaussian noise was formulated. However, this assumption may not be valid in most practical cases. Therefore, a bias-compensated PLKF with maximum correntropy criterion is introduced, resulting in two new filters: maximum correntropy pseudolinear Kalman filter (MC-PLKF) and maximum correntropy bias-compensated pseudolinear Kalman filter (MC-BC-PLKF). To demonstrate the performance of the proposed estimators, a comparative analysis assuming large outliers in the process and measurement model of 2D BoT is conducted. These large outliers are modeled as non-Gaussian noises with diverse noise distributions that combine Gaussian and Laplacian noises. The simulation results are validated using root mean square error (RMSE), average RMSE (ARMSE), percentage of track loss and bias norm. Compared to PLKF and BC-PLKF, all the proposed maximum correntropy-based filters (MC-PLKF and MC-BC-PLKF) performed with superior estimation accuracy.

关键词： Bearings-only target tracking Pseudolinear Kalman filter Maximum correntropy criterion Non-Gaussian noise

Covalent Bond Based Android Malware Detection Using Permission and System Call Pairs

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Computers, Materials & Continua 2024年第3期78卷 4283-4301页

作者： rahul Gupta Kapil Sharma R.K.Garg Department of Information Technology Delhi Technological UniversityNew Delhi110042India Department of Mechanical Engineering Deenbandhu Chhotu Ram University of Science and TechnologyMurthal131039India

The prevalence of smartphones is deeply embedded in modern society,impacting various aspects of our *** versatility and functionalities have fundamentally changed how we communicate,work,seek entertainment,and access *** the many smartphones available,those operating on the Android platform dominate,being the most widely used *** widespread adoption of the Android OS has significantly contributed to increased malware attacks targeting the Android ecosystem in recent ***,there is an urgent need to develop new methods for detecting Android *** literature contains numerous works related to Android malware *** far as our understanding extends,we are the first ones to identify dangerous combinations of permissions and system calls to uncover malicious behavior in Android *** introduce a novel methodology that pairs permissions and system calls to distinguish between benign and malicious *** approach combines the advantages of static and dynamic analysis,offering a more comprehensive understanding of an application’s *** establish covalent bonds between permissions and system calls to assess their combined *** introduce a novel technique to determine these pairs’Covalent Bond Strength *** pair is assigned two scores,one for malicious behavior and another for benign *** scores serve as the basis for classifying applications as benign or *** correlating permissions with system calls,the study enables a detailed examination of how an app utilizes its requested permissions,aiding in differentiating legitimate and potentially harmful *** comprehensive analysis provides a robust framework for Android malware detection,marking a significant contribution to the *** results of our experiments demonstrate a remarkable overall accuracy of 97.5%,surpassing various state-of-the-art detection techniques proposed in the current literature.

关键词： Android malware android security hybrid analysis permission and system call pairs

Assessment of public perspectives and barriers towards dengue preventive practices using the Health Belief Model in Puducherry,India:A cross-sectional study

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Asian Pacific Journal of Tropical Medicine 2024年第8期17卷 358-368,I0001页

作者： Dharani Govindasamy Gnanasekaran Vijalakashmi Balakrishnan Vijayakumar Arya rahul Indian Council of Medical Research-Vector Control Research Centre Deapartment of Health ResearchMinistry of Health and Family WelfareGovernment of IndiaPuducherryIndia

Objective:To assess the perspectives and barriers towards dengue preventive practices among the residents of Puducherry,***:A cross-sectional survey was conducted in 300 households in Puducherry,using a population-proportionate(7:3)distribution from urban and rural areas by grid *** adult interview per household was conducted and the participants were selected using a KISH grid.A semi-structured questionnaire based on the Health Belief Model(HBM)with additional questions on knowledge assessment was *** was assessed based on the correctness of answers and the HBM scores were calculated on a 5-point Likert *** were categorized based on the median score under each *** regression was used for adjusted analysis and models were built to predict the performances in each ***:Four percent of the participants lacked basic knowledge regarding dengue *** 208(69.3%)participants did not consider themselves at risk of contracting dengue within the next year,majority perceived dengue as a disease with low *** 49.3%(148)were skeptical about the benefit of time and money spent on dengue *** government efforts were stated as the major barrier(47.0%)and frequent reminders(142,47.3%)as the major cue to *** above 50 years(aOR 1.78,95%CI 1.04-3.06,P=0.037)and rural locality(aOR 2.68,95%CI 1.52-4.71,P=0.001)were found to be significantly associated with poor knowledge *** participants had a significantly higher chance to perceive low susceptibility as compared to the rural counterparts(aOR 1.74,95%CI 1.05-2.9,P=0.03).Participants with less than a high school education had low perceived benefits(aOR 2.46,95%CI 1.52-3.96,P<0.001)and low self-efficacy scores(aOR 2.66,95%CI 1.61-4.39,P<0.001).Conclusions:This study identifies key gaps in dengue prevention,including low perceived susceptibility,mild disease perception,limited knowledge of breeding sites,and overrelian

关键词： Dengue Public perspectives Prevention Barriers Health belief model