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Bistability and oscillations in co-repressive synthetic microbial consortia

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Frontiers of Electrical and Electronic Engineering in China 2017年第1期5卷 55-66页

作者： Mehdi Sadeghpour Alan Veliz-cuba Gabor Orosz Kresimir Josic Matthew R. Bennett Department of Mechanical Engineering University of Michigan Ann Arbor MI 48109 USA Department of Mathematics University of Dayton Dayton OH 45469 USA Department of Mathematics University of Houston Houston TX 77204 USA Department of Biology and Biochemistry University of Houston Houston TX 77204 USA Department of Biosciences Rice University Houston TX 77251-1892 USA Department of Bioengineering Rice University Houston TX 77251-1892 USA

Background： Synthetic microbial consortia are conglomerations of genetically engineered microbes programmed to cooperatively bring about population-level phenotypes. By coordinating their activity, the constituent strains can display emergent behaviors that are difficult to engineer into isogenic populations. To do so, strains are engineered to communicate with one another through intercellular signaling pathways that depend on cell density. Methods： Here, we used computational modeling to examine how the behavior of synthetic microbial consortia results from the interplay between population dynamics governed by cell growth and internal transcriptional dynamics governed by cell-ceil signaling. Specifically, we examined a synthetic microbial consortium in which two strains each produce signals that down-regulate transcription in the other. Within a single strain this regulatory topology is called a ＂co-repressive toggle switch＂ and can lead to bistability. Results： We found that in co-repressive synthetic microbial consortia the existence and stability of different states depend on population-level dynamics. As the two strains passively compete for space within the colony, their relative fractions fluctuate and thus alter the strengths of intercellular signals. These fluctuations drive the consortium to alternative equilibria. Additionally, if the growth rates of the strains depend on their transcriptional states, an additional feedback loop is created that can generate oscillations. Conclusions： Our findings demonstrate that the dynamics of microbial consortia cannot be predicted from their regulatory topologies alone, but are also determined by interactions between the strains. Therefore, when designing synthetic microbial consortia that use intercellular signaling, one must account for growth variations caused by the production of protein.

关键词： synthetic biology microbial consortia quorum sensing relaxation oscillations

cuba's Revolutionary Foreign Policy Concept

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Contemporary International Relations 2006年第12期16卷 1-10页

作者： Marcos Rodriguez Costa Deputy Foreign Minister of the Republic of cuba

At the invitation of Cui Liru,President of China Institutes of Contemporary International Relations(CICIR),cuban Deputy Foreign Minister Marcos Rodriguez Costa paid a visit to CICIR on November 13,*** are the contents... 详细信息

关键词：古巴外交政策国际关系总统

A method for microbial decontamination of Acanthamoeba cultures using the peritoneal cavity of mice

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Asian Pacific Journal of Tropical Biomedicine 2015年第10期5卷 796-800页

作者： Daniella de Sousa Mendes Moreira Alves Rodrigo Gurgel-Goncalves Patrícia Albuquerque César Augusto cuba-cuba Maria Imaculada Muniz-Junqueira Selma Aparecida Souza Kückelhaus Institute of Tropical Pathology and Public Health Federal University of Goias Laboratory of Medical Parasitology and Vector Biology Pathology University of Brasilia Faculty of Ceilandia University of Brasilia Laboratory of Cellular Immunology Pathology Faculty of Medicine University of Brasilia Area of Morphology Faculty of Medicine University of Brasilia

Objective: To evaluate whether the inoculation of contaminated cultures in the peritoneal cavity of mice could implement decontamination of Acanthamoeba ***: Suspensions of Acanthamoeba, Acanthamoeba polyphaga ATCC 30461, or Acanthamoeba spp. isolated from soil(Un B13 strain) were inoculated in the peritoneal cavity of Swiss mice(n = 24). After 1, 6, 12, or 24 h of exposure the peritoneal cavity was washed and assessed for the presence of bacteria, fungi, and ***: After 1 h of intraperitoneal inoculation at least 97% of the bacteria and 96% of the fungi(P < 0.05) and 99% of the bacteria(P < 0.05) were successfully eliminated from the ATCC 30461 strain and from the soil isolate Un B13 strain, respectively. This method also allowed the recovery of most trophozoites and cysts from both Acanthamoeba cultures at the end of 24 ***: Our data demonstrated that this technique has great potential for decontamination of Acanthamoeba cultures in a short period of time.

关键词： peritoneal fungi contaminated assessed microbial e

Observation of performance measures of STEMI in elderly after implementation of an updated protocol:results from a single center without coronary interventions

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Journal of Geriatric Cardiology 2022年第11期19卷 930-936页

作者： miguel Rodríguez-Ramos General Hospital Camilo Cienfuegos Bartolome Maso and Mirto Streets Sancti SpiritusCuba

As life expectancy increases,heart conditions,and especially acute coronary syndromes(ACS),are becoming a greater health issue.[1-3]Accordingly,the number of elderly patients in registries of myocardial infarction,is increasingly growing.[4,5]However,elderly patients are less likely to be treated with invasive strategy compared to younger patients,despite their intrinsic greater risk.[6,7]Several reports have described how quality initiatives improve treatment of ST elevation myocardial infarction(STEMI).

关键词： coronary STEMI Observation

Experimental culture of non-indigenous Juncus bufonius from King George Island, South Shetland Island, Antarctica

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Advances in Polar Science 2015年第1期26卷 24-29页

作者： Marely cuba-Díaz Eduardo Fuentes Mauricio Rondanelli-Reyes ángela Machuca Departamento Ciencias y Tecnología Vegetal Escuela Ciencias.y Tecnología Universidad de Concepción Campus Los ángeles Juan Antonio Coloma 0201Los ángeles Chile

Juncus bufonius L. （Juncaceae） is recognized by the US Department of Agriculture as a weed or invasive plant. Recently, we reported on 3i bufonius L. var. bufonius associated with the native vascular plants Deschampsia antarctica and Colobanthus quitensis in the environs of the Polish Arctowski Station, King George Island, in the Maritime Antarctica. In this study, we evaluated the developmental stages and morphological characteristics of J. bufonius plants cultivated in controlled conditions beginning with seeds obtained from plants of the Antarctic population. Germination occurred at 3 weeks and the germination percentage was low （22.5%）. The average time between the anthesis and seed formation was 7 weeks, similar to that reported for other species in the Juncaceae. According to data reported in the literature, Antarctic individuals were significantly smaller than their relatives growing in other conditions, except for the number of inflorescences. The morphological characteristics of a species vary according to its distribution and the edaphoclimatic environment where it occur; cosmopolitan plants shuch as J. bufonius also have reduced stature in cold environments. The low percentage germination may have been due to water availability in the plant chamber in which the study was conducted. J. bufonius is intolerant of dry environments, and once it suffers hydric stress its recovery is very low; thus, a moister environment could be beneficial. J. bufonius has become established amongst native vegetation near Arctowski Station and without careful control or eradication; it may have the potential to spread far beyond the site, as has happened with the alien grass Poa annua as human disturbance and climate warming increase.

关键词： Antarctica invasive plants Juncus bufonius (toad rush) non-native species regional warming

Hepatoprotective effects of diethylcarbamazine in acute liver damage induced by carbon tetrachloride in rats

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Acta Pharmacologica Sinica 1994年第6期 17-19+102页

作者： Ricardo GONZALEZ, Odelsa ANCHETA, Marlien MARQUEZ, Sandra RODRIGUEZ (Department of Pharmacology, National Center for Scientific Research, Apartado 6990, Ciudad Habana , cuba )

This research was carried out to determine a potential role of leukotrienes in the acute hepatotoxicity induced by CC14 in rats. An inhibitor of leukotrienes biosynthesis, diethylcarbamazine (DEC, 25 and 50 mg ·kg-1 ip) exerted hepatoprotective effects, decreasing the activity of alanine aminotransfer-ase in serum and the concentration of liver triglycerides. DEC reduced histological damage of liver evidenced by electron microscopy. The hepatoprotective effects of DEC were dose-dependent. The results favor the role of leukotrienes in CC14 hepatotoxicity.

关键词： diethylcarbamazine liver carbon tetrachloride poisoning alanine amino- transferase triglycerides

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生鲜电商转战线下

青年与社会（下） 2018年第10期 34-35页

作者： cuba Libre

生鲜市场是个老生常谈的话题，但生鲜电商市场，却风起云涌得有点意思一最近，一组关于生鲜电商的数据引起了业内的注意：生鲜电商增速已经放缓，2018年的电商增速预期下滑至47．3％一而根据艾媒北极星的数据显示，7月份，排名前五的生... 详细信息

生鲜市场是个老生常谈的话题，但生鲜电商市场，却风起云涌得有点意思一最近，一组关于生鲜电商的数据引起了业内的注意：生鲜电商增速已经放缓，2018年的电商增速预期下滑至47．3％一而根据艾媒北极星的数据显示，7月份，排名前五的生鲜电商APP中，活跃人数环比几乎都有所下滑.

关键词：数据显示北极星 APP 市场

Tectona grandis (Teak Tree) Young Leaf Extract as a Histological Stain

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Journal of Biomedical Science and Engineering 2023年第2期16卷 17-41页

作者： Cecilia Smith-Togobo Adam Abdul Fatau Magalys cuba Lopez Felix Kpor David Larbi Simpong George Osei Yiadom Emmanuel Akomanin Asiamah Department of Medical Laboratory Science School of Health and Allied Sciences University of Health and Allied Sciences Ho Ghana Department of Pathology School of Medicine University of Health and Allied Sciences Ho Ghana Department of Medical Laboratory Science Faculty of Allied Health Sciences University of Cape Coast Cape Coast Ghana

Stains are applied to impart contrast to the tissue and identify particular features of interest. However, the use of synthetic dyes as staining reagents has been associated with significant human health challenges and pollution of the ecosystem. These developments have necessitated a shift towards using natural dyes that are eco-friendlier and readily available. We investigated the staining reaction patterns of teak tree leaves (Tectona grandis) dye extracts and explored their suitability as a cytoplasmic stain in micromorphological assessments. Dye extracts were prepared using acetone, methanol, and ethanol as solvents from air-dried (under shade) teak tree young leaves. The dye extracts were applied as a counterstain and evaluated against eosin in formalin-fixed paraffin-embedded (FFPE) bovine tissue sections at varying concentrations and different staining times. Teak tree leaves (Tectona grandis) dye extracts produced relatively varying staining intensities of reddish-brown cytoplasmic coloration when used on bovine tissue at different concentrations and staining times comparable to eosin and with blue-purple hematoxylin nuclear stain. The present study showed that Tectona grandis leaf dye extracts provide an excellent cytoplasmic staining pattern and can be used as an alternative counterstain in routine H&E staining techniques.

关键词： Histology Cytoplasm Plant Extract Tectona grandis Leaves Formalin-Fixed Paraffin-Embedded Tissues Natural Dye Staining Cytoplasmic Stain Animal Tissues Staining Reaction

First Quantitative Estimates of Carbon Retention by Citrus Groves under cuba’s Conditions

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American Journal of Climate Change 2014年第2期3卷 130-144页

作者： Mayda Betancourt Nelvin Reyes Dalia Vázquez miguel D. Dufoo María E. García Arnaldo álvarez Agroforestry Research Institute Havana Cuba Autonomous University of Querétaro College Center Querétaro Mexico Tropical Fruit Crops Research Institute Havana Cuba

Citrus is one of the major fruit crops in cuba. Its perennial nature, the planted area and the time of productive exploitation turn it into a potential sink of atmospheric carbon. The present study was focused on the obtainment of two models that allow the quantitative estimation of carbon retention by citrus groves. The research was done in two commercial groves: orange [Citrus sinensis (L) Osbeck] cv. “Valencia Late” and grapefruit (Citrus paradisi Macf.) cv. “Marsh Seedless” both on sour orange (Citrus aurantium L.) and planted on a typical red ferralitic soil of Artemisa province. Groves are located at 22°55' North and 82°40' West. cuba’s climate is tropical, seasonally humid, with sea influence and semicontinentality features. Three issues were dealt with: 1) Determination of the total mean quantity of retained carbon by the aerial part of the trees using a destructive sampling method (Pattern Method) to estimate: the total volume of the tree, wood densities and green and dry biomass;2) Determination of the total mean quantity of retained carbon by the aerial part of the trees using two Allometric Methods;and 3) Determination of the most effective Allometric Method to estimate the carbon retention by the aerial part of the trees. From the results, it is concluded that the evaluated methods were effective to reach a first quantitative approximation to carbon retention by citrus groves and under equal conditions, the Allometric Method 2 was more accurate to estimate the Total Carbon Content in “Valencia Late” orange, while for “Marsh Seedless” grapefruit the Allometric Method 1 provided the best estimate.

关键词： Carbon Retention Citrus Allometric Methods Climate Change