检索结果-南通市图书馆

Simulations of a logistic-type model with delays for Chagas disease with insecticide spraying

International journal of Biomathematics 2017年第3期10卷 41-60页

作者： Nofe Al-Asuoad Tyler Pleasant Meir Shillor Hrishikesh Munugala Daniel j. Coffield jr. Anna Maria Spagnuolo Department of Mathematics and Statistics Oakland University Rochester MI 48309 USA Harrison High School MI USA Novi High School Novi MI 48375 USA Mathematics Department University of Michigan-Flint Flint MI 48502 USA

This work studies and numerically simulates a logistic-type model for the dynamics of Chagas disease, which is caused by the parasite T. cruzi and affects millions of humans and domestic mammals throughout rural areas in Central and South America. A basic model for the disease dynamics that includes insecticide spraying was developed in Spagnuolo et al. （2010） [271 and consists of a delay-differential equation for the vectors and three nonlinear ordinary differential equations for the populations of the infected vectors, infected humans and infected domestic mammals. In this work, the vector equation is modified by using a logistic term with zero, one or two delays or time lags. The aim of this study is three-fold： to numerically study the effects of using different numbers of delays on the model behavior; to find if twice yearly insecticide spraying schedules improve vector control; and to study the sensitivity of the system to the delays in the case of two delays, by introducing randomness in the delays. It is found that the vector equation with different number of delays has very different solutions. The ＂best＂ day of spraying is the middle of Spring and twice annual sprayings cause only minor improvements in disease control. Finally, the model is found to be insensitive to the values of the delays, when the delays are randomly distributed within rather narrow intervals or ranges centered on the parameter values used in Coffield et al. （2014） [8].

关键词： Chagas disease logistic equation with delays epidemic dynamics nonlinear dynamical system simulations.

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Factors that impact health-related quality of life in adults with celiac disease:A multicenter study

引用

world journal of Gastroenterology 2008年第1期14卷 46-52页

作者： F Casellas L Rodrigo j López Vivancos S Riestra C Pantiga jS Baudet F junquera V Puig Diví C Abadia M Papo j Gelabert jr Malagelada Digestive System Research Unit Hospital Universitari Vall d' Hebron Barcelona Spain Digestive System Research Unit Hospital Central de Asturias Oviedo Spain Digestive System Research Unit Internal Medicine Department Hospital General de Catalunya Barcelona Spain Digestive System Research Unit Hospital Virgen de la Candelaria Santa Cruz de Tenerife Spain Digestive System Research Unit Corporació Parc Taulí Sabadell Spain Digestive System Research Unit Hospital Joan ⅩⅩⅢ Tarragona Spain Digestive System Research Unit Hospital Verge del Toro Menorca Spain

AIM: To evaluate the factors involved in the impairment of health-related quality of life (HRQOL) in patients with celiac ***: A multicenter, cross-sectional prospective study was performed in patients with celiac disease who completed two HRQOL questionnaires: the gastrointestinal quality of life index (GIQLI) and the EuroQol-5D (EQ).RESULTS: Three hundred and forty patients (163 controlled with a gluten-free diet, and 177 newly diagnosed with a normal diet) were included. The GIQLI score was significantly better in patients on a gluten-free diet (GFD) than in non-treated patients on their usual diet, both in terms of the overall score (3.3 vs 2.7, respectively; P well as on the individual questionnaire dimensions. Both the preference value of the EQ as the visual analogue scale were significantly better in treated than in non-treated patients (0.93 vs 0.72 P with a worse HRQOL score were female gender, failure to adhere to a GFD, and symptomatic ***: In untreated celiac disease, the most important factors that influence patient perception of health are the presence of symptoms and a normal diet. HRQOL improves to levels similar to those described in the general population in celiac disease patients well controlled with a GFD.

关键词： Celiac disease, Health status Quality of life Gluten-free diet

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Reproductive potential of field-collected overwintering boll weevils （Coleoptera： Curculionidae） fed on pollen in the laboratory

引用

Insect Science 2009年第4期16卷 321-327页

作者： S. M. Greenberg G. D. jones j. j. Adamczyk, jr. F. Eischen j. S. Armstrong R. j. Coleman M. Setamou Tong-Xian Liu USDA-ARS-KSARC-BIRU 2413 E. Hwy. 83 Weslaco Texas 78596 APMRU-SPA-ARS-USDA College Station Texas 77845 USDA- ARS-KSA RC-Honey Bee Research Unit Texas A&M University Kingsville Citrus Center Weslaco TX 78596 Department of Entomology Texas AgriLife Research Texas A&M University System Weslaco Texas 78596 USA

The reproductive potential of overwintering boll weevil, Anthonomus grandis grandis （Boheman）, females collected from pheromone traps in September, November and january, fed for 1, 3, and 5 weeks on plant pollens, and then provided cotton squares, was determined in the laboratory at 27 ~ I^C, 65% RH, and a photoperiod 13 ： 11 （L ： D） h. Duration of pollen feeding by overwintering boll weevils did not significantly influence egg and feeding punctures, or puncture ratios （egg to total punctures） for any of the three months of parent weevil collections when provided cotton squares on a daily basis. However, punctures and puncture ratios are significantly different when comparing mean data between months of boll weevil collections. when boll weevils were provided with cotton squares daily, the pre-ovipositional periods of female parents captured in September, November and january were 5, 9 and 14 days, respectively. The rate of eggs by females was significantly lower during November and january than September. Female parents collected in September produced a significantly higher percentage of eggs yielding adult progeny than those collected in November and january. Life table parameters indicated that net reproductive rate （Ro） of boll weevil females collected in September was 1.2- fold higher than those collected in November and 10.7-fold higher than those collected in january. Except for testes size, no differences in male reproductive parameters were observed during the cotton-free period compared with males captured during mid-cotton （june）. The number of oocytes in the ovarioles and the number of ooeytes containing yolk were significantly lower during September, November and january compared with june. The reproductive potential ofoverwintering boll weevil females collected in different months is an important consideration in determining the success of any control strategy.

关键词： Anthonomusgrandisgrandis overwintering boll weevil reproductive pollen

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Can a multistage approach improve individual tree mortality predictions across the complex mixed-species and managed forests of eastern North America?

引用

Forest Ecosystems 2023年第1期10卷 21-30页

作者： Cen Chen john Kershaw jr Aaron weiskittel Elizabeth McGarrigle Center for Research on Sustainable Forests University of MaineOronoME04469USA Faculty of Forestry&Environmental Management University of New BrunswickFrederictonNBE3B 5A3Canada Nova Scotia Department of Natural Resources HalifaxNSB3J 3M8Canada

Tree mortality plays a fundamental role in the dynamics of forest ecosystems,yet it is one of the most difficult phenomena to accurately *** modeling strategies have been developed to improve individual tree mortality *** less explored strategy is the use of a multistage modeling *** improvements from this approach have remained largely *** this study,we developed a novel multistage approach and compared its performance in individual tree mortality predictions with a more conventional approach using an identical individual tree mortality model *** permanent plot data(n=9442)covering the Acadian Region of North America and over multiple decades(1965–2014)were used in this *** results indicated that the model behavior with the multistage approach better depicted the observed mortality and showed a notable improvement over the conventional *** difference between the observed and predicted numbers of dead trees using the multistage approach was much smaller when compared with the conventional *** addition,tree survival probabilities predicted by the multistage approach generally were not significantly different from the observations,whereas the conventional approach consistently underestimated mortality across species and overestimated tree survival probabilities over the large range of DBH in the *** new multistage approach also predictions of zero mortality in individual plots,a result not possible in conventional ***,the new approach was more tolerant of modeling errors because it based estimates on ranked tree mortality rather than error-prone predicted ***,this new multistage approach deserves to be considered and tested in future studies.

关键词： Tree mortality modeling Mortality disaggregation Mixed effect model Annualization Mixed forests

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new species of the genus Xenophrys(Anura:Megophryidae) from northern Thailand

引用

Zoological Research 2019年第6期40卷 564-574页

作者： Yun-He wu Chatmongkon Suwannapoom Nikolay A. Poyarkov,jr. Parinya Paawangkhanant Kai Xu jie-Qiong jin Robert w. Murphy jing Che State Key Laboratory of Genetic Resources and Evolution State Kunming Institute of ZoologyChinese Academy of SciencesKunming Yunnan 650223China Kunming College of Life Science University of the Chinese Academy of SciencesKunming Yunnan 650204China Southeast Asia Biodiversity Research Institute Chinese Academy of SciencesYezin Nay Pyi Taw 05282Myanmar School of Agriculture and Natural Resources University of PhayaoPhayao 56000Thailand Department of Vertebrate Zoology Biological FacultyLomonosov Moscow State UniversityMoscow 119991Russia joint Russian-Vietnamese Tropical Research and Technological Center 63 Nguyen Van Huyen RoadNghia DoCau GiayHanoiVietnam Centre for Biodiversity and Conservation Biology Royal Ontario MuseumToronto M5S 2C6Canada

DEAR EDITOR,Species of Xenophrys are conserved morphologically and live primarily in forests. In Thailand, the genus harbors many cryptic species. Herein we report the collection of specimens from Doi Inthanon, Chiang Mai Province, northern Thailand, which were identified previously as X. minor. Molecular and morphological analyses find that these specimens differ significantly from other known congeners, and therefore we describe a new species. Further, our phylogenetic analyses indicate that X. latidactyla is a junior synonym of X. palpebralespinosa.

关键词： genus Xenophrys Megophryidae Thailand

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Deadlock-free dynamic resource assignment in multi-robot systems with multiple missions:application in wireless sensor networks

引用

控制理论与应用（英文版） 2010年第1期8卷 12-19页

作者： P.M.BALLAL A.C.TRIVEDI V.GIORDANO j.MIRELES jr. F.L.LEwIS Automation & Robotics Research Institute University of Texas at Arlington

In unstructured environments, dynamic resource assignment is required for effective cooperation of robot teams. In some scenarios, robots are in charge of executing multiple missions simultaneously. This creates risks of deadlock due to the presence of shared resources among various missions. The main contribution of this paper is the development of a novel approach that combines the one-step look-ahead deadlock avoidance policy with dynamic resource assignment. The dynamicresource assignment is achieved using greedy resource assignment for multi-mission robot teams in the framework of a matrix-based discrete event controller. Simulation results are presented in MATLAB to discuss in detail the proposed control strategy. The paper also discusses the toolkit developed in LabVIEw which is used to implement this control framework using a suitable example.

关键词： Discrete event systems wireless sensor networks Deadlock avoidance Petri nets

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Survival of boll weevil （Coleoptera： Curculionidae） adults after feeding on pollens from various sources

引用

Insect Science 2007年第6期14卷 503-510页

作者： SHOIL M. GREENBERG GRETCHEN D. jONES FRANK EISCHEN RANDY j. COLEMAN jOHN j. ADAMCZYK, jr. TONG-XIAN LIU MAMOUDOU SETAMOU USDA-ARS KSARC-BIRU Weslaco USDA-ARS APMRU College Station USDA-ARS KSARC-Honey Bee Research Unit Department of Entomology Texas AgriLife Research Texas A&M University System Texas A&M University Kingsville Citrus Center Weslaco Texas USA

The survival of overwintering boll weevil, Anthonomus grandis grandis （Boheman）, adults on non-cotton hosts in the Lower Rio Grande Valley （LRGV） of Texas was examined from 2001 to 2006. The success of the Boll weevil Eradication Program, which was reintroduced into the LRGV in 2005, depends on controlling overwintering boll weevil populations. Laboratory studies were conducted using boll weevil adults that were captured in pheromone traps from September through March. The number of adults captured per trap declined significantly in the field from fall to the beginning of spring （3.5-7.0-fold）. The proportion of trapped males and females did not differ significantly. The mean weight of boll weevil adults captured in September was 13.3 mg, while those of captured adults from November to February were significantly lower and ranged from 6.7 to 7.8 mg. Our results show that boll weevil adults can feed on different plant pollens. The highest longevity occurred when adults were fed almond pollen or mixed pollens （72.6 days and 69.2 days, respectively） and the lowest when they fed on citrus pollen or a non-food source （9.7 days or 7.4 days, respectively）. The highest adult survival occurred on almond and mixed pollens [88.0%-97. 6% after 1st feeding period （10 days）, 78.0%-90.8% after 3rd feeding period （10 days）, 55. 0%-83.6% after 5th feeding period （10 days）, and 15.2%-32.4% after lOth feeding period （10 days）]. The lowest adult survival occurred on citrus pollen [52.0%-56.0% after 1st feeding period （10 days）, 13.3% after 3rd and 5th feeding periods （10 days）, and 0 after 6th feeding period （10 days）]. Pollen feeding is not a behavior restricted to adult boll weevils of a specific sex or physiological state. Understanding how boll weevil adults survive in the absence of cotton is important to ensure ultimate success of eradicating this pest in the subtropics.

关键词： boll weevil Anthonomus grandis grandis Curculionidae subtropics pollen

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Mind-Brain Problem Bose-Einstein Statistics, Temperature, Heat, Entropy God and Other Elementary Particles

引用

journal of Modern Physics 2020年第9期11卷 1330-1360页

作者： walter j. Christensen jr. Physics and Astronomy Department Cal Poly Pomona University Pomona CA USA

The purpose of this research is to apply the Einstein’s principle of relativity to solve the mind-brain problem and to generate all Standard Model Particle masses. Our approach is somewhat analogous to the dualistic idea of Descartes. Instead of a pineal gland, wherein the brain interacts with the mind, we propose during the developmental stages of the human fetus the tiny brain begins to communicate with the smallest structures of spacetime. This interaction occurs as the fetus brain begins to emit thermodynamic low heat energies, which are then absorbed into the smallest structures of spacetime saturating the interstices of the fetus brain. Think of these heat-energies like Morse code instructions. Since these kinds of interaction involve spacetime, with brain matter-energy, and that our main guiding principle is that of relativity, our research resulted in a general relativistic wave equation, wherein the n-valued heat-energies emitted by the brain-field-matrix white-space:normal;">Bwhite-space:normal;">μv, is identified as the energy momentum tensor of general relativity. The spacetime mind-matrix (white-space:normal;">Mwhite-space:normal;">μv) is likewise identified as the Riemannian curvature matrix. Together they form a general relativistic expression given by: Mμwhite-space:normal;">white-space:normal;">v +Pμwhite-space:normal;">white-space:normal;">v M=cBμ

关键词： Mind-Body Problem Thermodynamics Heat Energy General Relativity Particle Mass Problem Hydrogen Spectra Consciousness God Particle Neuro-Fields Spacetime Mind Neuroscience Neurotrophins

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Endophytic and pathogenic fungi of developing cranberry ovaries from flower to mature fruit:diversity and succession

引用

Fungal Diversity 2012年第3期54卷 101-116页

作者： Mariusz Tadych Marshall S.Bergen jennifer johnson-Cicalese james j.Polashock Nicholi Vorsa james F.white jr Department of Plant Biology and Pathology Rutgers University59 Dudley RoadNew BrunswickNJ 08901USA Philip E.Marucci Center for Blueberry and Cranberry Research and Extension Rutgers University125A Lake Oswego RoadChatsworthNJ 08019USA Genetic Improvement of Fruits and Vegetables Laboratory USDA-ARS125A Lake Oswego RoadChatsworthNJ 08019USA

Culturable fungal population diversity and succession was investigated in developing cranberry ovaries of fruit rot-resistant and rot-susceptible cranberry selections,from flower through mature *** were recovered in culture from 1185 of 1338 ovary tissues collected from june to September,yielding 2255 isolates that represented 42 *** the season,species richness varied from 2 to 17 and 2 to 18 in rot-resistant and rotsusceptible selections,respectively,increasing from wk1 to wk10 and then gradually declining to ***-wiener diversity index varied from 0.27 to 2.32 in rotresistant and 0.18 to 2.38 in rot-susceptible,and Pielou’s evenness index varied from 0.11 to 0.63 and 0.06 to 0.64 in rot-resistant and rot-susceptible selections,respectively,confirming that diversity of fungi in developing ovaries was similar among rot-resistant and rot-susceptible selections,but varied among sampling time *** component analysis grouped samples collected at the same sampling time point together regardless of rot susceptibility of the selections,and detected the predominant fungal species associated with each stage of *** changes were observed in populations of endophytic,pathogenic and saprophytic fungi throughout the season as ovaries matured.

关键词： Aetiology Cranberry fruit rot Pathogens Phenology Resistance Vaccinium macrocarpon

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

无机基体聚锑酸^(44)Ti-^(44)Sc发生器

引用

同位素 1992年第1期5卷 24-30页

作者：崔安智 O'Brien H.A.jr. Steinkruger F.j. Taylor.w.A 中国原子能科学研究院北京102413 洛斯-阿拉莫斯国家实验室

经过实验筛选,第一次采用聚锑酸Polyan HT为吸附剂,HCl-(NH_1)_2C_2O_4为淋洗剂,制备了^(14)Ti-^(44)Sc发生器。^(44)Sc对^(44)Ti的分离因子大于10~6,^(44)Sc的回收率为80%左右,柱子可反复淋洗^(44)Sc 200次。

关键词：无机吸附剂聚锑酸钛44 钪44 发生器

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：