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Global-in-time Uniform Convergence for Linear Hyperbolic-Parabolic Singular Perturbations

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Acta Mathematica Sinica,English Series 2006年第4期22卷 1161-1170页

作者： marina GHISI Massimo GObbINO Universitàdegli Studi di Pisa Dipartimento di Matematicavia M.Buonarroti 256127 PISAItaly Universitàdegli Studi di Pisa Dipartimento di Matematica Applicata "Ulisse Dini"via Bonanno 25/B56126 PISAItaly

We consider the Cauchy problem εu^″ε ＋ δu′ε ＋ Auε = 0, uε（0） = uo, u′ε（0） = ul, where ε 〉 0, δ 〉 0, H is a Hilbert space, and A is a self-adjoint linear non-negative operator on H with dense domain D（A）. We study the convergence of （uε） to the solution of the limit problem ,δu＇＋ Au = 0, u（0） = u0. For initial data （u0, u1） ∈ D（A1/2）× H, we prove global-in-time convergence with respect to strong topologies. Moreover, we estimate the convergence rate in the case where （u0, u1）∈ D（A3/2） ∈ D（A1/2）, and we show that this regularity requirement is sharp for our estimates. We give also an upper bound for ｜u′ε（t）｜ which does not depend on ε.

关键词： Parabolic equations Damped hyperbolic equations Singular perturbations

Will vaccine-derived protective immunity curtail COVID-19 variants in the US?

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Infectious Disease Modelling 2021年第1期6卷 1110-1134页

作者： marina Mancuso Steffen E.Eikenberry Abba b.Gumel Arizona State University School of Mathematical and Statistical SciencesTempeAZ85287USA Department of Mathematics and Applied Mathematics University of PretoriaPretoria0002South Africa

Multiple effective vaccines are currently being deployed to combat the COVID-19 pandemic,and are viewed as the major factor in marked reductions of disease burden in regions with moderate to high vaccination *** effectiveness of COVID-19 vaccination programs is,however,significantly threatened by the emergence of new SARS-COV-2 variants that,in addition to being more transmissible than the wild-type(original)strain,may at least partially evade existing vaccines.A two-strain(one wildtype,one variant)and two-group(vaccinated or otherwise)mechanistic mathematical model is designed and used to assess the impact of the vaccine-induced cross-protective efficacy on the spread the COVID-19 pandemic in the United *** analysis of the model shows that,in the absence of any co-circulating SARS-CoV-2 variant,the vaccine-derived herd immunity threshold needed to eliminate the wild-type strain can be achieved if 59%of the US population is fully-vaccinated with either the Pfizer or Moderna *** threshold increases to 76%if the wild-type strain is co-circulating with the Alpha variant(a SARS-CoV-2 variant that is 56%more transmissible than the wild-type strain).If the wild-type strain is co-circulating with the Delta variant(which is estimated to be 100%more transmissible than the wild-type strain),up to 82%of the US population needs to be vaccinated with either of the aforementioned vaccines to achieve the vaccine-derived herd *** sensitivity analysis of the model reveal the following four parameters as the most influential in driving the value of the reproduction number of the variant strain(hence,COVID-19 dynamics)in the US:(a)the infectiousness of the co-circulating SARS-CoV-2 variant,(b)the proportion of individuals fully vaccinated(using Pfizer or Moderna vaccine)against the wild-type strain,(c)the cross-protective efficacy the vaccines offer against the variant strain and(d)the modification parameter accounting for the reduced infectio

关键词： COVID-19 Vaccine Wild-type Variant Reproduction number Herd immunity

Rickettsia influences thermotolerance in the whitefly bemisia tabaci b biotype

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Insect Science 2011年第1期18卷 57-66页

作者： marina brumin Svetlana Kontsedalov Murad Ghanim Department of Entomology Institute of Plant Protection the Volcani Center Bet Dagan Israel

The whitefly bemisia tabaci harbors Portiera aleyrodidarum, an obligatory symbiotic bacterium, as well as several secondary symbionts, including Rickettsia, Hamiltonella, Wolbachia, Arsenophonus, Cardinium and Fritschea, the function of which is unknown. In Israel, Rickettsia is found in both the b and Q ofb. tabaci biotypes, and while all other secondary symbionts are located in the bacteriomes, Rickettsia can occupy most of the body cavity of the insect. We tested whether Rickettsia influences the biology of b. tabaci and found that exposing a Rickettsia-containing population to increasing temperatures significantly increases its tolerance to heat shock that reached 40~C, compared to a Rickettsia-free population. This increase in tolerance to heat shock was not associated with specific induction of heat-shock protein gene expression; however, it was associated with reduction in Rickettsia numbers as was assessed by quantitative real-time polymerase chain reaction and fluorescence in situ hybridization analyses. To assess the causes for thermotolerance when Rickettsia is reduced, we tested whether its presence is associated with the induction of genes required for thermotolerance. We found that under normal 25℃ rearing temperature, genes associated with response to stress such as cytoskeleton genes are induced in the Rickettsia-containing population. Thus, the presence of Rickettsia in b. tabaci under normal conditions induces the expression of genes required for thermotolerance that under high temperatures indirectly lead to this tolerance.

关键词： cytoskeleton gene expression heat shock symbiont

Levi and Malcev Theorems for Finite-Dimensional Algebras from the Variety Defined by the Identities x^(2)=J(x,y,zu)=0

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Algebra Colloquium 2021年第1期28卷 87-90页

作者： Oscar Guajardo Garza marina Rasskazova Liudmila Sabinina Centro de Investigacion en Ciencias UAEMCuernavacaMexico Omsk State Technical University pr.Mira 11OmskRussia

We study the variety of binary Lie algebras defined by the identities x^(2)=J(x,y,zu)=0,where J(a,b,c)denotes the Jacobian of a,b,*** on previous work by Carrillo,Rasskazova,Sabinina and Grishkov,in the present articl... 详细信息

关键词： Malcev theorem Levi factor splitting algebra binary Lie algebra

Rule-based scheduling of air conditioning using occupancy forecasting

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Energy and AI 2020年第2期2卷 43-53页

作者： marina Dorokhova Christophe ballif Nicolas Wyrsch Photovoltaics and Thin-Film Electronics Laboratory(PV-Lab)Ecole Polytechnique Federale de Lausanne(EPFL) Institute of Microengineering(IMT)Rue de la Maladière 71bNeuchatel 2000Switzerland

Heating,ventilation and air conditioning systems represent considerable potential for energy savings,which can be realized through intelligent occupancy-centered control *** this work,both supervised and unsupervised algorithms to forecast occupancy are proposed with the highest accuracies of 98.3%and 97.6%,*** on their output,a rule-based air conditioning scheduling technique is *** an example,a potential of 15.4%of energy savings is calculated using a dataset collected in a mid-size(4000 m 2)building in Portugal.

关键词： Automation Energy savings HVAC control Occupancy forecasting Thermal comfort

Effect of yttrium on photosynthesis and water relations in young maize plants

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Journal of Rare Earths 2014年第4期32卷 371-378页

作者： Ivana Maksimovi Rudolf Kastori marina Putnik-Deli Milan boriev Faculty of Agriculture University of Novi Sad Department of biology and Ecology Faculty of SciencesUniversity of Novi Sad

Despite an increase in spectrum of industrial applications of yttrium （Y） and the fact that it is widely present in the soils and plants, some of which are agronomically important crops, its effects on plant growth and metabolism are still obscure. Therefore, the aim of this work was to examine the effect of different concentrations of Y on its accumulation and distribution, photosynthetic responses, water relations, free proline concentration and growth of young maize plants. The experiment was done with maize （Zea mays L., hybrid NS-640）, in water cultures, under semi-controlled conditions of a greenhouse. Plants were supplied with half-strength complete Hoagland nutrient solution, to which was added either 0 （control）, 10-5, 10-4 or 10-3 mol/L Y, in the form of Y（NO）3·5H2O. Each variant was set in thirteen replications, with six plants in each replication. Plants were grown for 21 d and they were at the stage of 3 and 4 leaves when they were analyzed. The presence of Y reduced maize growth and photosynthetic performance. Dimensions of stomata significantly decreased while their density significantly increased on both adaxial and abaxial epidermis. Plant height, root length, total leaf area and dry mass also declined. Concentration of photosynthetic pigments （chl a and b and carotenoids） and free proline decreased. Photosynthesis and transpiration were impaired in the presence of Y-their intensities were also reduced, and the same stands for stomatal conductance of water vapor, photosynthetic water use efficiency （WUE） and water content. Although the highest concentration of Y was found in maize roots in each treatment, Y concentration in the second leaf and shoot also significantly increased with an increase in Y concentration in the nutrient solution. Albeit Y concentration was much higher in roots than in shoots, shoot metabolism and growth were much more disrupted. The results demonstrated that young maize plants accumulated significant amount of Y and that th

关键词： yttrium maize photosynthesis water use efficiency rare earths

Genes associated with testicular germ cell tumors and testicular dysgenesis in patients with testicular microlithiasis

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Asian Journal of Andrology 2018年第6期20卷 593-599页

作者： Ilya S Dantsev Evgeniy V Ivkin Aleksey A Tryakin Dmitriy N Godlevski Oleg Yu Latyshev Victoriya V Rudenko Dmitry S Mikhaylenko Vyacheslav b Chernykh Elena A Volodko Aleksey b Okulov Oleg b Loran marina V Nemtsova Russian Medical Academy ef Postgraduate Education Moscow 123995Russia N.N.blokhin Russian Cancer Research Center Moscow 115478Russia Research Centre of Medical Genetics Moscow 115478Russia M.Sechenov First Moscow State Medical University Moscow 119991Russia N.I.Pirogov Russian National Research Medical University Moscow 117997Russia.

Testicular microlithiasis （TM） is one of the symptoms of testicular dysgenesis syndrome （TDS）. TM is particularly interesting as an informative marker of testicular germ cell tumors （TGCTs）. KIT ligand gene （KITLG）, bCL2 antagonist/killer 1 （bAK1）, and sprouty RTK signaling antagonist 4 （SPRY4） genes are associated with a high risk of TGCTs, whereas bone morphogenetic protein 7 gene （bMP7）, transforming growth factor beta receptor 3 gene （TGFbR3）, and homeobox D cluster genes （HOXD） are related to TDS. Using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） analysis, we investigated allele and genotype frequencies for KITLG （rs995030, rs1508595）, SPRY4 （rs4624820, rs6897876）, bAK1 （rs210138）, bMP7 （rs388286）, TGFbR3 （rs12082710）, and HOXD （rs17198432） in 142 TGCT patients, 137 TM patients, and 153 fertile men （control group）. We found significant differences in the KITLG GG_rs995030 genotype in TM （P= 0.01） and TGCT patients （P = 0.0005） compared with the control. We also revealed strong associations between KITLGrs1508595 and TM （G allele, P = 0.003; GG genotype, P= 0.01） and between KITLG_rs1508595 and TGCTs （G allele, P-- 0.0001; GG genotype, P = 0.0007）. Moreover, there was a significant difference in bMP7_rs388286 between the TGCT group and the control （T allele, P = 0.00004; TT genotype, P = 0.00006） and between the TM group and the control （T allele, P= 0.04）. HOXDalso demonstrated a strong association with TGCTs （rs17198432 A allele, P = 0.0001; AA genotype, P = 0.001）. Furthermore, significant differences were found between the TGCT group and the control in the bAK1_rs210138 G allele （P= 0.03） and the GG genotype （P= 0.01）. KITLG and bMP7genes, associated with the development of TGCTs, may also be related to TM. In summary, the KITLG GG_rs995030, GG_rs1508595, bMP7 TT_rs388286, HOXD AA_rs17198432, and bAK1 GG_rs210138 genotypes were associated with a high risk of TGCT development.

关键词： associations genotype high risk testicular dysgenesis syndrome testicular microlithiasis

Inhibition of α-glucosidase activity by N-deoxynojirimycin analogs in several insect phloem sap feeders

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Insect Science 2016年第1期23卷 59-67页

作者： marina Katzman Ya'kobovitz Terry D. butters Ephraim Cohen Department of Entomology Robert H. Smith Faculty of Agriculture Food and Environment The Hebrew University of Jerusalem RehovotIsrael Department of biochemistry University of Oxford Oxford OX1 3QU UK

Secondary metabolites and synthetic iminosugars that structurally resemble monosaccharides are potent inhibitors of a-glucosidase activity. The enzyme is core in cleaving sucrose in phloem feeding insects and it also plays a crucial role of reducing osmotic stress via the formation of oligosaccharides. Inhibition of hydrolysis by iminosug- ars should result in nutritional deficiencies and/or disruption of normal osmoregulation. Deoxynojirimycin （DNJ） and 2 N-alkylated analogs [N-butyl DNJ （Nb-DNJ） and N-nonyl DNJ （NN-DNJ）] were the major iminosugars used throughout the study. The extensive experiments conducted with a-glucosidase of the whitefly bemisia tabaci indicated the competitive nature of inhibition and that the hydrophilic DNJ is a potent inhibitor in com- parison to the more hydrophobic Nb-DNJ and NN-DNJ compounds. The same inhibitory pattern was observed with the psyllid Cacopsylla bidens a-glucosidase. In contrast to the above pattern, enzymes of the aphids, Myzus persicae and Aphis gossypii were more sen- sitive to the hydrophobic iminosugars as compared to DNJ. In vivo experiments in which adult b. tabaci were fed dietary iminosugars, show that the hydrophilic DNJ was far less toxic than the lipophilic Nb-DNJ and NN-DNJ. It is proposed that this pattern is attributed to the better accessibility of the hydrophobic NN-DNJ to the a-glucosidase membrane- bound compartment in the midgut. based on the inhibitory effects of certain polyhydroxy N-alkylated iminosugars, a-glucosidase of phloem feeding hemipterans could serve as an attractive target site for developing novel pest control agents.

关键词： a-glucosidase inhibition bemisia tabaci Cacopsylla bidens iminosugars Myzuspersicae osmoregulation phloem sap feeders

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Current Zoology 2024年第1期70卷 1-12页

作者： Lucia V.Sommaro Juan J.Martinez marina b.Chiappero Andrea R.Steinmann Cristina N.Gardenal JoséW.Priotto Laboratorio de Ecologia Evolutiva y biogeografia Instituto de Ecorregiones Andinas(INECoA)Universidad Nacional de Jujuy-Consejo Nacional de Investigaciones Cientificas y Tecnicas(CONICET)San Salvador de JujuyJujuyArgentina Instituto de Diversidad y Ecologia Animal(IDEA) Consejo Nacional de Investigaciones Cientificas y Técnicas(CONICET)and Universidad Nacionalde CordobaCordobaArgentina Catedra de Genética de Poblaciones y Evolucion Facultad de Ciencias ExactasFisicas y NaturalesUniversidad Nacional de CordobaCordobaArgentina Grupo de Investigaciones en Ecologia Poblacional y Comportamental(GIEPCO) Instituto de Ciencias de la TierraBiodiversidad y Ambiente(ICBiA)Universidad Nacional de Rio Cuarto-Consejo Nacional de Investigaciones Cientificas y Técnicas(CONICET)Rio CuartoCordobaArgentina

The sex-biased dispersal and kinship dynamics are important factors shaping the spatial distribution of individuals and are key parameters affecting a variety of ecological and evolutionary ***,we studied the spatial distribution of related individuals within a population of corn mice Calomys musculinus in a seasonal cycle to infer dispersal *** sampling was carried out from spring 2005 to winter 2006 in field borders of intensively managed *** data from 346 individuals with 9 microsatellites showed spatial genetic structure was weak for males,but not for *** results indicate a complex spatial kinship dynamic of related females across all ***,contrary to our expectations,dispersal distances decrease with the increase of the population ***,male dispersal distances were greater when population abundance increased and thus the availability of active *** disperse greater distances to mate and sire offspring with distant females as a possible inbreeding avoidance *** study shows that *** is capable of much greater scattering distances than previously reported and that dispersal occurs fluidly and without barriers across the *** indirect benefit of dispersal on individual fitness could be related to relaxing the competition in the natal area and increasing the mating *** study highlights the value of combining genetic relatedness,fieldwork observations,and behavioral data to estimate dispersal at a fine geographical scale.

关键词： dispersal distances kinship dynamics microsatellite small mammals spatial autocorrelation