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Oxygen isotope-salinity relation in an Arctic fjord(Kongsfjorden):Implications to hydrographic variability

Geoscience Frontiers 2018年第6期9卷 1937-1943页

作者： manish tiwari Siddhesh Nagoji Vikash Kumar Shubham Tripathi Padmasini Behera National Centre for Polar&Ocean Research Vasco-da-GamaGoa 403804India

The global warming leads to a large freshwater influx into the Arctic Ocean, which has adverse implications to the sea-ice dynamics, ocean circulation, and acidification. The relationship between oxygen isotope ratio(δ^(18)O) and salinity(S) is helpful in exploring various hydrographic processes related to the freshwater influx and is also required to accurately determine past salinity variability using oxygen isotope ratio of the carbonates. In view of this, systematic measurements of δ^(18)O and salinity of water from an Arctic fjord(Kongsfjorden) were carried out during the summer season of 2013. Until now, the relationships between δ^(18)O and salinity from such fjords were based on a limited number of samples collected during a very short span of time and thus may not accurately represent the long-term conditions prevailing in the fjord. The present study determines a more representative δ^(18)O-salinity relationship as water samples from different depths and location over a long period were systematically collected. The water samples were collected from four different locations at different depths along the axis of the fjord representing the inner and outer fjords. The inner stations(1-8 and 1-6) exhibit lowerδ^(18)O values than the outer stations(1-1 and 1-3), which indicate the higher influence of freshwater from glacial melting in the inner stations. The δ^(18)O-salinity relationship from the inner and outer fjords yield a slope of 0.54(r^2 = 0.67, n = 56) and 0.39(r^2 = 0.66, n = 68), respectively. The δ^(18)O of freshwater influx in the fjord is estimated at-18.4‰, which is close to the widely accepted freshwater-δ^(18)O value of the Arctic basin. The δ^(18)O of glacial discharge, which is the largest source of freshwater influx to the fjord, is estimated at ca.-21.0‰, which will be useful for future freshwater budget calculations.

关键词： Arctic Fjord Oxygen isotopes Salinity Freshwater Melting

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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

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Chalcogenide photonic crystal fiber for ultraflat mid-infrared supercontinuum generation

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Chinese Optics Letters 2016年第12期14卷 141-145页

作者： Sandeep Vyas Takasumi Tanabe manish tiwari Ghanshyam Singh Department of ECE Vivekananda Institute of Technology (East) Department of EEE Keio University Department of ECE Manipal University Department of ECE Malaviya National Institute of Technology

In this Letter, we numerically simulate the generation of a 1–15 μm mid-infrared supercontinuum（SC） from a highly nonlinear Ge_（11.5）As24Se_（64.5）-based photonic crystal fiber（PCF）. This ultra-broadband SC is achieved in a100 mm long PCF pumped using 85 fs laser pulses operated at 3.1 μm and a peak pulse power of 3 k W. The proposed design offers a flat dispersion profile with two zero dispersion wavelengths. This broad and flat dispersion profile of the Ge_（11.5）As24Se_（64.5）PCF, combined with the high nonlinearity（2474 W-1km-1）, generates an ultra-broadband SC.

关键词： photonic pumped operated broadband nonlinearity numerically soliton silica pumping pitch

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A Survey on the Stability of 2-D Discrete Systems Described by Fornasini-Marchesini Second Model

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Circuits and Systems 2012年第1期3卷 17-22页

作者： manish tiwari Amit Dhawan 不详

A key issue of practical importance in the two-dimensional (2-D) discrete system is stability analysis. Linear state-space models describing 2-D discrete systems have been proposed by several researchers. A popular model, called Forna- sini-Marchesini (FM) second model was proposed by Fornasini and Marchesini in 1978. The aim of this paper is to present a survey of the existing literature on the stability of FM second model.

关键词： 2-D Discrete Systems FM Second Model Asymptotic Stability Lyapunov Methods

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Robust Suboptimal Guaranteed Cost Control for 2-D Discrete Systems Described by Fornasini-Marchesini First Model

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Journal of Signal and Information Processing 2012年第2期3卷 252-258页

作者： manish tiwari Amit Dhawan Electronics and Communication Engineering Department Motilal Nehru National Institute of Technology Allahabad India.

This paper considers the guaranteed cost control problem for a class of two-dimensional (2-D) uncertain discrete systems described by the Fornasini-Marchesini (FM) first model with norm-bounded uncertainties. New linear matrix inequality (LMI) based characterizations are presented for the existence of static-state feedback guaranteed cost controller which guarantees not only the asymptotic stability of closed loop systems, but also an adequate performance bound over all the admissible parameter uncertainties. Moreover, a convex optimization problem is formulated to select the suboptimal guaranteed cost controller which minimizes the upper bound of the closed-loop cost function.

关键词： Guaranteed Cost Control Linear Matrix Inequality Lyapunov Methods Robust Stability 2-D Discrete Systems Uncertain Systems

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Supplementation of L-ascorbic acid improves the in vitro development of buffalo(Bubalus bubalis)embryos and alters the expression of apoptosis-related genes

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Asian pacific Journal of Reproduction 2021年第1期10卷 36-42页

作者： Mayank Roshan Diksha Dua Ankur Sharma manish tiwari Manoj Kumar Singh Suresh Kumar Singla Prabhat Palta Radhay Sham Manik Manmohan Singh Chauhan Embryo Biotechnology Lab Animal Biotechnology CentreICAR-National Dairy Research InstituteKarnalIndia

Objective:To study the effect of L-ascorbic acid supplementation on the in vitro development of buffalo embryos and evaluate the relative mRNA abundance of some pro-apoptotic,anti-apoptotic,and embryonic development-related ***:In experiment 1,we evaluated the effect of the addition of 0(control),50,and 100μM L-ascorbic acid to the in vitro maturation medium on the developmental competence in terms of blastocyst rate and relative mRNA abundance of some pro-apoptotic(BAX,BID),anti-apoptotic(BCL-XL,MCL1),and embryonic development(GDF9,BMP15)related *** on the results,we chose 50μM as the suitable dose of L-ascorbic acid for the subsequent *** further evaluated the blastocyst rates following the addition of 50μM L-ascorbic acid to the in vitro culture medium(experiment 2),and in vitro maturation and in vitro culture media(experiment 3).In all three experiments,the maturation and culture media devoid of L-ascorbic acid served as the control ***:The blastocyst rate after adding 50μM L-ascorbic acid to the in vitro maturation medium was significantly higher than the control group(P<0.05),whereas 100μM L-ascorbic acid exhibited a negative effect on the blastocyst *** blastocyst rates for embryos cultured in 50μM L-ascorbic acid in the in vitro culture medium alone and both in vitro maturation and in vitro culture media were significantly higher than their corresponding control groups(P<0.05).The relative mRNA abundance of BAX significantly decreased in blastocysts produced after the addition of 50μM L-ascorbic acid as compared with the control group(P<0.05),whereas,for MCL1,it significantly decreased in blastocysts produced after the addition of 100μM L-ascorbic acid(P<0.05).Conclusions:The supplementation of 50μM L-ascorbic acid to in vitro maturation and in vitro culture media supports in vitro embryonic development in buffaloes by improving developmental competence and altering the expression of apoptosis-related genes.

关键词： Buffalo Blastocyst In vitro embryo production L-ascorbic acid Oocyte

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In vivo miniature robots for natural orifice surgery:State of the art and future perspectives

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World Journal of Gastrointestinal Surgery 2010年第6期2卷 217-223页

作者： manish M tiwari Jason F Reynoso Amy C Lehman Albert W Tsang Shane M Farritor Dmitry Oleynikov Department of Surgery University of Nebraska Medical Center985126 Nebraska Medical Center OmahaNE 68198-5126United States Department of Mechanical Engineering University of Nebraska-LincolnN104 Scott Engineering CenterLincolnNE 68588-0656United States

Natural orifice translumenal endoscopic surgery(NOTES) is the integration of laparoscopic minimally invasive surgery techniques with endoscopic *** the advances in NOTES technology,the approach presents several unique instrumentation and techniquespecific *** ? exible endoscopy platforms for NOTES have several drawbacks including limited stability,triangulation and dexterity,and lack of adequate visualization,suggesting the need for new and improved instrumentation for this *** of the current focus is on the development of flexible endoscopy platforms that incorporate robotic *** alternative approach to access the abdominal viscera for either a laparoscopic or NOTES procedure is the use of small robotic devices that can be implanted in an intracorporeal ***,independent,miniature robots can be simultaneously inserted into the abdominal cavity to provide a robotic platform for NOTES *** capabilities of the robots include imaging,retraction,tissue and organ manipulation,and precise maneuverability in the abdominal *** a platform affords several advantages including enhanced visualization,better surgical dexterity and improved triangulation for *** review discusses the current status and future perspectives of this novel miniature robotics platform for the NOTES *** these technologies are still in pre-clinical development,a miniature robotics platform provides a unique method for addressing the limitations of minimally invasive surgery,and NOTES in particular.

关键词： Robotic surgery In vivo robots Natural orifice surgery Robotic surgical platforms

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Cloning ＆ sequence identification of Hsp27 gene and expression analysis of the protein on thermal stress in Lucilia cuprina

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Insect Science 2016年第4期23卷 555-568页

作者： manish K. Singh Pramod K. tiwari Center for Genomics Molecular & Human Genetics Jiwaji University Gwafior 474011 Cytogenetics Laboratory Department of Zoology Banaras Hindu University Varanasi 221005 India

Hsp27, a highly conserved small molecular weight heat shock protein, is widely known to be developmentally regulated and heat inducible. Its role in thermotolerance is also implicated. This study is a sequel of our earlier studies to understand the molecular organization of heat shock genes/proteins and their role in development and thermal adaptation in a sheep pest, Lucilia cuprina （blowfly）, which exhibits unusually high adaptability to a variety of environmental stresses, including heat and chemicals. In this report our aim was to understand the evolutionary relationship of Lucilia hsp27 gene/protein with those of other species and its role in thermal adaptation. We sequence characterized the Lchsp27 gene （coding region） and analyzed its expression in various larval and adult tissues under normal as well as heat shock conditions. The nucleotide sequence analysis of 678 bps long-coding region of Lchsp27 exhibited closest evolutionary proximity with Drosophila （90.09%）, which belongs to the same order, Diptera. Heat shock caused significant en- hancement in the expression ofLchsp27 gene in all the larval and adult tissues examined, however, in a tissue specific manner. Significantly, in Malpighian tubules, while the heatinduced level ofhsp27 transcript （mRNA） appeared increased as compared to control, the protein level remained unaltered and nuclear localized. We infer that Lchsp27 may have significant role in the maintenance of cellular homeostasis, particularly, during summer months, when the fly remains exposed to high heat in its natural habitat.

关键词： heat shock protein Hsp27 Lucilia cuprina thermal stress

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Prediction of significant hyperbilirubinemia in term neonates by early non-invasive bilirubin measurement

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World Journal of Pediatrics 2017年第3期13卷 222-227页

作者： manish Jain Akash Bang Anju tiwari Shuchi Jain Department of Pediatrics MGIMSSevagramWardha MaharashtraIndia Department of Obstetrics&Gynecology MGIMSSevagramWardha MaharashtraIndia

Background:Neonatal jaundice is a common *** evaluated the utility and best cut-off values of 24-and 48-hour transcutaneous bilirubin indices (TcBI) in predicting subsequent significant hyperbilirubinemia and evaluated various associated maternal and fetal risk ***:TcBI at 24 and 48 hours and serum bilirubin levels at 72 hours of age were obtained for healthy,term,appropriate for gestational age *** with prematurity,birth weight 17 mg/dL after 72 hours of life and various cut-offs,and were evaluated by calculating sensitivity,specificity and predictive ***:Of 500 newborns,4.6% had significant hyperbilirubinemia,27% had TcBI (mg/dL) <5 at 24 hours,and 27.4% had TeBI <8 at 48 *** of them had subsequent hyperbilirubinemia (100% negative predictive value).The percentage of newborns with subsequent hyperbilirubinemia increased from 3.4% to 13.2% as their 24-hour TcBI increased from 6 to above 9 mg/dL and from 4.2% to 7.4% as their 48-hour TcBI increased from 8 to above 11 mg/*** best cut-off value was TcBI (mg/dL) 7 (odd ratio=4.86,95% confidence interval:1.66-15.22) at 24 hours and 10 (odd ratio=2.87,95% confidence interval:1.04-8.29) at 48 *** under the receiver operating characteristic curve for 24-and 48-hour measurements was 0.750 and 0.715,*** premature rupture of membranes,deep transverse arrest,post-date pregnancy,and fetal distress were significant risk factors for ***:Twenty-four and 48-hour TcB indices are good predictors of subsequent ***-four-hour TcBI had better predictive abili

关键词： hyperbilirubinemia neonate transcutaneous bilirubin

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