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Switching effect on a two prey-one predator system with strong Allee effect incorporating prey refuge

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International Journal of Biomathematics 2024年第2期17卷 1-50页

作者： Sangeeta saha Guruprasad Samanta Department of Mathematics Indian Institute of Engineering Science and Technology Shibpur Howrah 711103India

In an environment,the food chains are balanced by the prey-predator *** a predator species is provided with more than one prey population,it avails the option of prey switching between prey species according to their ***,prey switching of predators mainly helps to increase the overall growth rate of a predator *** this work,we have proposed a two prey-one predator system where the predator population adopts switching behavior between two prey species at the time of *** the prey population exhibit a strong Allee effect and the predator population is considered to be a generalist *** proposed system is biologically well-defined as the system variables are positive and do not increase abruptly with *** local stability analysis reveals that all the predator-free equilibria are saddle points whereas the prey-free equilibrium is always *** intrinsic growth rates of prey,the strong Allee parameters,and the prey refuge parameters are chosen to be the controlling parameters *** numerical simulation reveals that in absence of one prey,the other prey refuge parameter can change the system dynamics by forming a stable or unstable limit ***,a situation of bi-stability,tri-stability,or even multi-stability of equilibrium points occurs in this *** in presence of the switching effect,the predator chooses prey according to their abundance,so,increasing refuge in one prey population decreases the count of the second prey *** is also observed that the count of predator population reaches a comparatively higher value even if they get one prey population at its fullest quantity and only a portion of other prey ***,in the scarcity of one prey species,switching to the other prey is beneficial for the growth of the predator population.

关键词： Prey-predator model switching effect strong Allee effect prey refuge

On the Geometry of the Anti-canonical Bundle of the Bott–Samelson–Demazure–Hansen Varieties

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1920-1940页

作者： Indranil BISWAS S.Senthamarai KANNAN Pinakinath saha School of Mathematics Tata Institute of Fundamental Research1 Homi Bhabha RoadMumbai 400005India Chennai Mathematical Institute Plot H1SIPCOT IT ParkSiruseriKelambakkam603103India

Let G be a semi-simple simply connected algebraic group over the field C of complex *** T be a maximal torus of G,and let W be the Weyl group of G with respect to *** Z(w,i)be the Bott–Samelson–Demazure–Hansen variety corresponding to a tuple i associated to a reduced expression of an element w∈*** prove that for the tuple i associated to any reduced expression of a minuscule Weyl group element w,the anti-canonical line bundle on Z(w,i)is globally *** consequence,we prove that Z(w,i)is weak *** that G is a simple algebraic group whose type is different from *** S={α1,...,αn}be the set of simple *** w be such that support of w is equal to *** prove that Z(w,i)is Fano for the tuple i associated to any reduced expression of w if and only if w is a Coxeter element and w^(−1)(Σ_(t=1)^(n)αt)∈−S.

关键词： Bott-Samelson-Demazure-Hansen variety Coxeter element anti-canonical line bundle Fano weak Fano

Cosmic implications of the 12C(n, γ)13C reaction: a nuclear astrophysical perspective

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Chinese Physics C 2024年第2期48卷 171-174页

作者： Soumya saha Department of Physics Bidhan Chandra CollegeRishra31G.T.Road(East)Hooghly-712248India Department of Physics University of Calcutta92Acharya Prafulla Chandra RoadKolkata-700009India

We conducted a comprehensive study of the neutron capture cross section of 12C within the relevant astrophysical energy *** rigorous R-matrix analysis,we determined the Maxwellian-averaged cross section to be 11.98±0.25μb at kT=30 *** result is approximately four times higher than the thermal neutron capture cross section estimated in earlier studies assuming the 1/v *** implications of our findings extend to the region of inhomogeneous Big-Bang models in nuclear astrophysics,where understanding the behaviour of neutron capture cross sections plays a crucial role in elucidating the intricate processes that shaped the early universe.

关键词： reaction cross section R-matrix reaction rates spectroscopic factors

Improving Heat Transfer in Parabolic Trough Solar Collectors by Magnetic Nanofluids

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Energy Engineering 2024年第4期121卷 835-848页

作者： Ritesh Singh Abhishek Gupta Akshoy Ranjan Paul Bireswar Paul Suvash C.saha Department of Applied Mechanics Motilal Nehru National Institute of Technology AllahabadPrayagrajIndia Department of Mechanical and Mechatronic Engineering University of Technology SydneySydneyAustralia

A parabolic trough solar collector(PTSC)converts solar radiation into thermal ***,low thermal efficiency of PTSC poses a hindrance to the deployment of solar thermal power *** performance of PTSC is enhanced in this study by incorporating magnetic nanoparticles into the working *** circular receiver pipe,with dimensions of 66 mm diameter,2 mm thickness,and 24 m length,is exposed to uniform temperature and velocity *** working fluid,Therminol-66,is supplemented with Fe3O4 magnetic nanoparticles at concentrations ranging from 1%to 4%.The findings demonstrate that the inclusion of nanoparticles increases the convective heat transfer coefficient(HTC)of the PTSC,with higher nanoparticle volume fractions leading to greater heat transfer but increased pressure *** thermal enhancement factor(TEF)of the PTSC is positively affected by the volume fraction of nanoparticles,both with and without a magnetic ***,the scenario with a 4%nanoparticle volume fraction and a magnetic field strength of 250 G exhibits the highest TEF,indicating superior thermal *** findings offer potential avenues for improving the efficiency of PTSCs in solar thermal plants by introducing magnetic nanoparticles into the working fluid.

关键词： Parabolic trough solar collector(PTSC) magnetic nanofluid(MNF) heat transfer convective heat transfer coefficient(HTC) thermal enhancement factor(TEF)

Effectiveness of hybrid ensemble machine learning models for landslide susceptibility analysis:Evidence from Shimla district of North-west Indian Himalayan region

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Journal of Mountain Science 2024年第7期21卷 2368-2393页

作者： SHARMA Aastha SAJJAD Haroon RAHAMAN Md Hibjur saha Tamal Kanti BHUYAN Nirsobha Department of Geography Faculty of SciencesJamia Millia IslamiaNew Delhi-110025India

The Indian Himalayan region is frequently experiencing climate change-induced ***,landslide susceptibility assessment assumes greater significance for lessening the impact of a landslide *** paper makes an attempt to assess landslide susceptibility in Shimla district of the northwest Indian Himalayan *** examined the effectiveness of random forest(RF),multilayer perceptron(MLP),sequential minimal optimization regression(SMOreg)and bagging ensemble(B-RF,BSMOreg,B-MLP)models.A landslide inventory map comprising 1052 locations of past landslide occurrences was classified into training(70%)and testing(30%)*** site-specific influencing factors were selected by employing a multicollinearity *** relationship between past landslide occurrences and influencing factors was established using the frequency ratio *** effectiveness of machine learning models was verified through performance *** landslide susceptibility maps were validated by the area under the receiver operating characteristic curves(ROC-AUC),accuracy,precision,recall and *** key performance metrics and map validation demonstrated that the BRF model(correlation coefficient:0.988,mean absolute error:0.010,root mean square error:0.058,relative absolute error:2.964,ROC-AUC:0.947,accuracy:0.778,precision:0.819,recall:0.917 and F-1 score:0.865)outperformed the single classifiers and other bagging ensemble models for landslide *** results show that the largest area was found under the very high susceptibility zone(33.87%),followed by the low(27.30%),high(20.68%)and moderate(18.16%)susceptibility *** factors,namely average annual rainfall,slope,lithology,soil texture and earthquake magnitude have been identified as the influencing factors for very high landslide *** texture,lineament density and elevation have been attributed to high and moderate ***,the study calls for devising suitable landslide mitig

关键词： Landslide susceptibility Site-specific factors Machine learning models Hybrid ensemble learning Geospatial techniques Himalayan region

Hydro-uvarovite from Mantle Peridotites of Naga Hills Ophiolite: A Mineral Tracer for Neo-Tethyan Mantle Wedge Metasomatism

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Acta Geologica Sinica(English Edition) 2024年第4期98卷 867-877页

作者： Anisha VERENCAR Abhishek saha Nilanjana SORCAR Sohini GANGULY Pankaj KUMAR Atul Kumar SINGH CSIR-National Institute of Oceanography Dona PaulaGoa 403004India School of Earth Ocean and Atmospheric SciencesGoa UniversityTaleigao PlateauGoa 403206India National Centre for Earth Science Studies ThiruvananthapuramKeralaIndia Inter University Accelerator Centre(IUAC) New Delhi 110067India North-Eastern Hill University ShillongMeghalaya 793022India

Hydrous Cr-bearing uvarovite garnets are rare in natural occurrences and belong to the ugrandite series and exist in binary solid solutions with grossular and andradite garnets. Here, we report the occurrence of hydrous uvarovite garnet having Cr_(2)O_(3) upto 19.66 wt% and CaO of 32.12–35.14 wt% in the serpentinized mantle peridotites of Naga Hills Ophiolite(NHO), India. They occur in association with low-Cr diopsides. They are enriched in LILE(Ba, Sr), LREEs, with fractionating LREE-MREE [avg.(La/Sm)_(N) = 2.16] with flat MREE/HREE patterns [avg.(Sm/Yb)_(N) = 0.95]. Raman spectra indicate the presence of hydroxyl(OH^(–)) peaks from 3500 to 3700 cm^(-1). Relative abundances in fluid mobile elements and their close association with clinopyroxenes are suggestive of the formation of uvarovite garnets through low temperature metasomatic alteration of low-Cr diopsides by hydrothermal slab fluids. The high LREE concentration and absence of Eu anomaly in the garnet further attest to alkaline nature of the transporting slab dehydrated fluid rather the involvement of low-p H solution. The chemical characteristics of the hydroxyl bearing uvarovite hosted by the mantle peridotite of NHO deviate from the classical features of uvarovite garnet, and their origin is attributed to the fluid-induced metasomatism of the sub arc mantle wedge in a suprasubduction zone regime.

关键词： uvarovite hydroxyl metasomatic alteration low-Cr diopsides serpentinization mantle peridotite

Arbuscular mycorrhizal fungi regulate plant mineral nutrient uptake and partitioning in iron ore tailings undergoing eco-engineered pedogenesis

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Pedosphere 2024年第2期34卷 385-398页

作者： Zhen LI Songlin WU Yunjia LIU Qing YI Merinda HALL Narottam saha Junjian WANG Yuanfang HUANG Longbin HUANG College of Land Science and Technology China Agricultural UniversityBeijing 100193China Centre for Mined Land Rehabilitation Sustainable Minerals InstituteThe University of QueenslandBrisbaneQLD 4072Australia Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control School of Environmental Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China

Excess available K and Fe in Fe ore tailings with organic matter amendment and water-deficiencies may restrain plant colonization and growth,which hinders the formation of eco-engineered soil from these tailings for sustainable and cost-effective mine site *** mycorrhizal(AM)fungi are widely demonstrated to assist plant growth under various unfavorable ***,it is still unclear whether AM symbiosis in tailings amended with different types of plant biomass and under different water conditions could overcome the surplus K and Fe stress for plants in Fe ore tailings,and if so,by what ***,host plants(Sorghum *** ***),either colonized or noncolonized by the AM fungi(Glomus spp.),were cultivated in lucerne hay(LH,C:N ratio of 18)-or sugarcane mulch(SM,C:N ratio of 78)-amended Fe ore tailings under well-watered(55%water-holding capacity(WHC)of tailings)or water-deficient(30%WHC of tailings)*** mycorrhizal colonization,plant growth,and mineral elemental uptake and partitioning were *** indicated that AM fungal colonization improved plant growth in tailings amended with plant biomass under water-deficient *** mycorrhizal fungal colonization enhanced plant mineral element uptake,especially P,both in the LH-and SM-amended tailings regardless of water ***,AM symbiosis development restrained the translocation of excess elements(i.e.,K and Fe)from plant roots to shoots,thereby relieving their *** AM fungal roles in P uptake and excess elemental partitioning were greater in LH-amended tailings than in SM-amended *** deficiency weakened AM fungal colonization and functions in terms of mineral element uptake and *** findings highlighted the vital role AM fungi played in regulating plant growth and nutrition status in Fe ore tailings technosol,providing an important basis for involvement of AM fungi in the eco-engineered pedo

关键词： Fe stress fungal symbiosis K stress mine site rehabilitation mycorrhizal colonization plant biomass amendment plant nutrition water deficiency

Dengue hemorrhagic fever with rectus sheath hematoma:A case report

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Asian Pacific Journal of Tropical Medicine 2024年第3期17卷 136-138页

作者： Boudhayan Bhattacharjee Hardik Patel Rucha Karad Vasireddy Teja Agnibho Mondal Soumendra Nath Haldar Bibhuti saha Department of Infectious Diseases and Advanced Microbiology School of Tropical MedicineKolkataIndia

Rationale:Acute pain is a medical emergency that requires prompt abdominal evaluation and ***,a mosquito-borne arboviral infection,can lead to complications such as acute abdominal *** concerns:A 72-year-old hypertensive female presented with high-grade intermittent fever with chills and rigors for four *** was diagnosed with dengue fever(NS1Ag-reactive)the day before admission.A contrast-enhanced computed tomography of the abdomen showed a hematoma along the rectus sheath which was managed conservatively as per surgical ***:Dengue hemorrhagic fever with rectus sheath ***:Blood transfusion and fluid ***:Ten days after discharge,the patient reproted no pain in the right iliac fossa and the size of the hematoma was significantly ***:Although it is rarely seen as a cause of acute abdomen,complaints of adnominal pain should never be ignored in critical or convalescent phase of dengue *** investigations should be promptly conducted as hematoma is often difficult to be diagnosed *** in diagnosis of rectus sheath hematoma can be fatal.

关键词： Dengue fever Rectus sheath hematoma Surgical emergency Acute appendicitis

Are gender inclusiveness and rural transformation interlinked?The case of Bangladesh

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Journal of Integrative Agriculture 2024年第6期23卷 2112-2126页

作者： Maria Fay Rola-Rubzen Mohammad Jahangir Alam Jon Marx Sarmiento Ismat Ara Begum Al Amin Al Abbasi Subrata saha UWA School of Agriculture and Environment The University of Western AustraliaPerth 6009Australia Department of Agribusiness and Marketing Bangladesh Agricultural UniversityMymensingh-2202Bangladesh Department of Agricultural Economics Bangladesh Agricultural UniversityMymensingh-2202Bangladesh

Gender inclusiveness is important in the rural transformation process of Bangladesh as rural women play key roles in both agricultural and non-agricultural *** inclusiveness also leads to gender *** empirically evaluate relationships between rural transformation and gender inclusiveness in *** consider three rural transformation indicators:high-value commodities’share in agricultural output values,non-farm employment’s share in rural labor employment,and non-agricultural GDP’s share in total *** capturing gender inclusiveness include the per capita rural income of males and females,ratio of investments into gender programs,female access to education,access to healthcare,employment participation,land ownership,and asset *** test the effect of the difference in per capita rural income of males and females and the ratio of their incomes and check for the robustness of the gender variables across different model *** 128 district-level observations from 32 districts of Bangladesh across four time periods(2000,2005,2010 and 2016),we use both ordinary least squares and fixed effects panel regression *** find that female land and asset ownership and access to education and healthcare are robust determinants of various stages of rural ***,our results suggest that improving women’s ownership of land and assets and investing in women’s education and healthcare will likely contribute to a more inclusive rural transformation.

关键词： rural transformation Bangladesh gender inclusiveness investments on women