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Habitat fragmentation, vole population fluctuations, and the RoMPA hypothesis: An experimental test using model landscapes

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Integrative Zoology 2016年第6期11卷 469-482页

作者： George o.BATZLI Department of Animal Biology University of IllinoisChampaignIllinoisUSA

Increased habitat fragmentation leads to smaller size of habitat patches and to greater distance between patch*** RoMPA hypothesis(ratio of optimal to marginal patch area)uniquely links vole population fluctuations to the composition of the *** states that as RoMPA decreases(fragmentation increases),vole population fluctuations will increase(including the tendency to display multi-annual cycles in abundance)because decreased proportions of optimal habitat result in greater population declines and longer recovery time after a harsh *** date,only comparative observations in the field have supported the *** paper reports the results of the first experimental test.I used prairie voles,Microtus ochrogaster,and mowed grassland to create model landscapes with 3 levels of RoMPA(high with 25%mowed,medium with 50%mowed and low with 75%mowed).As RoMPA decreased,distances between patches of favorable habitat(high cover)increased owing to a greater proportion of unfavorable(mowed)*** from the first year with intensive live trapping indicated that the preconditions for operation of the hypothesis existed(inversely density dependent emigration and,as RoMPA decreased,increased per capita mortality and decreased per capita movement between optimal patches).Nevertheless,contrary to the prediction of the hypothesis that populations in landscapes with high RoMPA should have the lowest variability,5 years of trapping indicated that variability was lowest with medium *** design of field experiments may never be perfect,but these results indicate that the RoMPA hypothesis needs further rigorous testing.

关键词： experimental landscapes habitat fragmentation Microtus ochrogaster RoMPA hypothesis vole population fluctuations

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Derivation of a segregation-mixing equation for particles in a fluid medium

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Applied Mathematics and Mechanics(English Edition) 2009年第6期30卷 765-770页

作者： Donald o. Besong Department of Numerical Analysis and Computer Science (NADA) Royal Institute of TechnologyS-10044 StockholmSweden

The main purpose of this work is to show that the gravity term of the segregation-mixing equation of fine mono-disperse particles in a fluid can be derived from first-principles （i.e., elementary physics）. our derivation of the gravity-driven flux of particles leads to the simplest case of the Richardson and Zaki correlation. Stokes velocity also naturally appears from the physical parameters of the particles and fluid by means of derivation only. This derivation from first-principle physics has never been presented before. It is applicable in small concentrations of fine particles.

关键词： gravity segregation Kynch batch flux first-principles derivation Burger-type equation

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Growth in Infinite Groups of Infinite Subsets

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Algebra Colloquium 2015年第2期22卷 333-348页

作者： J.o. Button Selwyn College University of Cambridge Cambridge CB3 9DQ UK

Given an infinite group G, we consider the finitely additive invariant measure defined on finite unions of cosets of finite index subgroups. We show that this shares many properties with the size of subsets of a finite group, for instance we can obtain equivalent results on the Ruzsa distance and product free sets. In particular, if G has infinitely many finite index subgroups, then it has subsets S of measure arbitrarily close to 1/2 with square S2 having measure less than 1. We also examine properties of the Ruzsa distance on the set of finite index subgroups of an infinite group, whereupon it becomes a genuine metric.

关键词： group product set, Ruzsa distance

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Geochemical record for the depositional condition and petroleum potential of the Late Cretaceous Mamu Formation in the western flank of Anambra Basin, Nigeria

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Green Energy & Environment 2020年第1期5卷 83-96页

作者： Gbenga o.ogungbesan Taofik AAdedosu Department of Earth Sciences Ladoke Akintola University of TechnologyP.M.B.4000OgbomosoNigeria Department of Chemistry Ladoke Akintola University of TechnologyP.M.B.4000OgbomosoNigeria

Carbonaceous shale exposures of the Late Cretaceous Mamu Formation along Ifon-Uzebba road in western arm(Benin Flank) of Anambra Basin, southwestern Nigeria, were analyzed for bulk organic geochemical, molecular biological and poly-aromatic hydrocarbon(PAH) compositions to investigate the organic matter source, paleo-depositional condition, thermal maturity and petroleum potential of the unit. The bulk organic geochemistry was determined using Leco and Rock-Eval pyrolysis analyses while the biomarkers and PAH compositions were investigated using gas chromatography-mass spectrometer(GC-MS).The bulk organic geochemical parameters of the shale samples showed total organic carbon(ToC)(1.11-6.03 wt%), S2(0.49-11.73 mg HC/g Rock), HI(38-242 mg HC/g ToC) and Tmax(425-435 C) indicating good to excellent hydrocarbon source-rock. Typical HI-Tmax diagram revealed the shale samples mostly in the gas-prone Type Ⅲ kerogen region with few gas and oil-prone Type Ⅱ-Ⅲ kerogen. The investigated biomarkers(n-alkane, isoprenoid, terpane, hopane, sterane) and PAH(alkylnaphthalene, methylphenanthrene and dibenzothiophene) indicated that the carbonaceous shales contain mix contributions of terrestrial and marine organic matter inputs that were deposited in a deltaic to shallow marine settings and preserved under relatively anoxic to suboxic *** maturity parameters computed from Rock-Eval pyrolysis, biomarkers(hopane, sterane) and PAH(alkylnaphthalene, alkylphenanthrene, alkyldibenzothiophene) suggested that these carbonaceous shales in Anambra Basin have entered an early-mature stage for hydrocarbon generation. This is also supported by fluoranthene/pyrene(0.27-1.12), fluoranthene/(fluoranthene + pyrene)(0.21-0.53) ratios and calculated vitrinite reflectance values(0.49-0.63% Ro) indicative that these shales have mostly reached early oil window maturity, thereby having low hydrocarbon source potential.

关键词： Anambra Basin Mamu formation Paleoenvironment Kerogen Thermal maturity

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Metformin treatment of high-fat diet-fed obese male mice restores sperm function and fetal growth,without requiring weight loss

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Asian Journal of Andrology 2020年第6期22卷 560-568页

作者： Nicole o McPherson Michelle Lane Robinson Research Institute School of MedicineUniversity of AdelaideAdelaide 5005Australia Freemasons Foundation Centre for Men's Health University of AdelaideAdelaide 5005Australia Repromed Dulwich 5065Australia Monash IVF Group Melbourne 3000Australia.

Male obesity is associated with subfertility and increased disease risk of *** is unknown if effects can be reversed through pharmacological ***-to 6-week-old C57BL6 male mice were fed control diet(n=10,CD)or high-fat diet(n=20,HFD)for 16 *** fed with a HFD were then allocated to continuation of HFD(n=8)or HFD with metformin 28 mg kg1 day-1(n=8)for 6 *** fed with CD continued on a CD(n=9).Males were mated with fertile C57BL6 females for the assessment of pregnancy and fetal *** motility,spermatozoa and testicular morphology,sperm-zona pellucida binding,sperm reactive oxygen species(RoS)(intracellular[DCFDA],superoxide[MSR],and oxidative DNA lesions[8oHdG]),and mitochondrial membrane potential(JC1)were *** treatment of HFD males improved glucose toleranee(+12%,Pomeostatic Model Assessment of Insulin Resistance(HoMA-IR;-36%,Poccurred in the absenee of a change in body weight or *** treatment of HFD-fed males restored testicular morphology(+33%,Potility(+66%,Pona pellucida binding(+25%,PoS concentrations(-32%,Poxidative DNA lesions(-45%,Po the levels of the CD *** treatment of HFD fathers increased fetal weights and lengths compared with those born to HFD fathers(+8%,Pored to those of fetuses of CD ***-term metformin treatment in men who are obese could be a potential intervention for the treatment of subfertility,without the need for a reduction in body weight/adiposity.

关键词： fertility glucose metabolic syndrome overweight subfertility

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Identification, isolation and characterization of the antifeedant constituent of Clausena anisata against Helicoverpa armigera （Lepidoptera： Noctuidae）

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Insect Science 2009年第3期16卷 247-253页

作者： olufemi o. R. Pitan o. o. Ayelaagbe Hong-Lei Wang Chen-Zhu Wang State Key Laboratory of Integrated Management of Pest insects and Rodents Institute of Zoology Chinese Academy of Sciences BeijingChina Department of Crop Protection University of Agriculture Abeokuta Department of Chemistry University of Ibadan IbadanNigeria

Hexane, petroleum ether, chloroform, ethyl acetate, methanol and water extracts of Clausena anisata [（Willd.） Hook E Ex Benth] leaves and roots were evaluated against Helicoverpa armigera （Hubner） for antifeedant activities. Antifeedant activity was confirmed, and was found to be higher in root extracts than those of the leaf. Chloroform and petroleum ether extracts of the root showed strongest antifeedant activities （DC50s [concentration （C） causing 50% deterrence compared with the control] 0.014% and 0.016% respectively）, and root extracts were fractionated using silica gel column chromatography. one fraction of the chloroform and one of the petroleum ether root extracts was active; and on the basis of mass spectroscopy and ^1H and ^13C nuclear magnetic resonance spectral data, the active compounds in the two fractions were confirmed to be identical, and identified as osthol [2H-1-Benzopyran-2-one, 7-methoxy-8-（3-methyl-2-butenyl）]. The highest concentration of osthol was found in the chloroform root extract. Antifeedant activities of the root extracts, as measured by DC50 values, were highly correlated with their osthol contents. Approximately 99% of the variation in bioactivity of the root extracts could be accounted for by variation in osthol content; osthol therefore, appeared to be an antifeedant component of C. anisata to H. armigera. This may provide a new approach to managing this pest.

关键词： active ingredient antifeedant Clausena anisata Helicoverpa armigera,osthol root

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Thermodynamic second law analysis of magneto-micropolar fluid flow past nonlinear porous media with non-uniform heat source

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Propulsion and Power Research 2020年第3期9卷 281-288页

作者： E.o.Fatunmbi S.o.Salawu Department of Mathematics and Statistics Federal PolytechnicIlaroNigeria Department of Mathematics Landmark UniversityOmu-AranNigeria

This study analyzes the second law of thermodynamic for entropy generation in an irreversible hydromagneto-micropolar flow system with non-homogenous heat *** non-symmetric microstructure fluid flow past a stretching sheet with saturated porous nonlinear media under magnetic field *** the fluid particle deformation,the microstructure is assumed rigid with the viscous suspended *** reduced dimensionless nonlinear formulated model is computationally coded and solved to obtain solutions for the entropy volumetric production,Bejan number and heat transfer magneto-micropolar *** parameter dependent solutions for the flow characteristics and irreversibility processes are plotted and *** is revealed from the study that minimization of entropy generation in a magneto-micropolar flow system is possible by improving the thermodynamic equilibrium with low material variables,viscosity and hysteresis ***,it is seen that the terms that encourage internal heat generation reduces the micropolar fluid viscosity in the system.

关键词： Micropolar Non-Newtonian fluid Entropy generation Stretching sheet Thermodynamic law

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Proactive psychological and psychiatric support of patients with chronic noncommunicable diseases in a randomised trial:a Ukrainian experience

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General Psychiatry 2022年第5期35卷 319-327页

作者： o o Khaustova M V Markova M o Driuchenko A o Burdeinyi Medical Psychology Psychosomatic Medicine and PsychotherapyBogomolets National Medical UniversityKyivUkraine Sexology Psychotherapy and Medical PsychologyKharkiv Medical Academy of Postgraduate EducationKharkivUkraine Uzhhorod National University UzhhorodUkraine Bogomolets National Medical University KyivUkraine

Background Presently, approaches for the early treatment of pathological anxiety in patients with chronic non-communicable diseases are lacking, thus delaying the initiation of symptom management at the early onset of the illness. Proactive psychological and psychiatric support, to alleviate subclinical symptoms of anxiety and to improve the quality of life in patients with chronic non-communicable diseases, is a promising candidate for the role of such *** To investigate and determine the effectiveness of proactive psychological and psychiatric support for alleviating subclinical symptoms of anxiety and improving quality of life, in patients with chronic non-communicable *** The study design was a monocentric randomised controlled trial with parallel groups. The study, involving 193 inpatients with chronic non-communicable diseases, complied with the ethical and deontological norms in accordance with the principles set out in the Declaration of Helsinki. Instruments used in the study included the Hamilton Anxiety Scale (HAM-A) to assess subclinical symptoms, the Scale of Somatic Symptoms and the Chaban Quality of Life Scale. Block randomisation was used to randomise patients to a 2-month-long study group with a proactive counselling psychiatry model care or a control group with standard regulated treatment for chronic non-communicable diseases. The allocation ratio was 1.15:1 owing to the expectancy of a higher percentage of dropout in the intervention *** After 60 days of treatment (T2), there was a statistically significant difference in all clinical parameters between the study and control groups. The median HAM-A value differed between the groups by 4.87 points, with statistically significant lower results in the study group. The comparison of the study group’s scale values on day 1 and day 60 demonstrated statistically significant changes in all three *** our results support existing evidence for the effective

关键词： patients diseases psychiatric

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Irreversibility analysis of unsteady couette flow with variable viscosity

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Journal of Hydrodynamics 2015年第2期27卷 304-310页

作者： EEGUNJoBI A.S. MAKINDE o.D. TSHEHLA M.S. FRANKS o. Department of Mathematics and Statistics Namibia University of Science and Technology Faculty of Military Science Stellenbosch University Faculty of Engineering Built Environment and Information Technology Nelson Mandela Metropolitan University Faculty of Military Science Stellenbosch University

This paper investigates numerically the inherent irreversibility in unsteady generalized Couette flow between two parallel plates with variable viscosity. The nonlinear governing equations are derived from the Navier-Stokes equations and solved numerically using a semi-discretization finite difference method together with the Runge-Kutta-Fehlberg integration scheme. The profiles of velocity and the temperature obtained are used to compute the entropy generation number, Bejan number, skin friction and Nusselt number. The effects of embedded parameters on entire flow structure are presented graphically and discussed quantitatively.

关键词： parallel plates variable viscosity heat transfer Couette flow entropy generation

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Beneficiation Study on a Nigerian Baryte ore for Industrial Use

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Journal of Materials Science & Technology 1997年第1期13卷 76-78页

作者： V. o.Nwoko and o. o. onyemaobi (Dept. of Materials and Metallurgical Engineering, Federal University of Technology, owerri, Nigeria) Dept. of Materials and Metallurgical Engineering Federal University of Technology Owerri Nigeria

Beneficiation study on samples of baryte ore from Azare in the Plateau State of Nigeria was carried out using chemical analysis, atomic absorption spectrophotometric analysis, jigging and magnetic separation. Results show that Azare baryte can profitably be concentrated for use in oil drilling and other industrial purposes. Barium sulphate content in the head ore analyzed, is 98%. Comparison between jigging and magnetic separation shows that jigging produces a more satisfactory result.

关键词： Beneficiation Study on a Nigerian Baryte ore for Industrial Use

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