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Glutamine-released ammonia acts as an unprecedented signaling molecule activating lipid production

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Genes & Diseases 2023年第2期10卷 307-309页

作者： Chunming Cheng scott Kelsey Deliang Guo Department of Radiation Oncology Ohio State Comprehensive Cancer CenterArthur G. James Cancer Hospital and Richard J. Solove Research Instituteand College of Medicine at The Ohio State UniversityColumbusOH 43210USA Center for Cancer Metabolism James Comprehensive Cancer Center at The Ohio State UniversityColumbusOH 43210USA

In healthy humans, ammonia circulates in the bloodstream at a concentration around 11–32 μmol/L. Whether ammonia plays any physiological role has been unknown until a recent report published in Nature Metabolism.1 Ammonia, long thought to be a toxic waste product of amino acid metabolism, needs to be excreted from the human body as urea. Intriguingly, in this paper, Cheng et al1 for the first time reported that ammonia is not a waste product;rather, it is an unprecedented signaling molecule tying glucose and glutamine to lipid production in human cells. This study revealed that ammonia released from glutamine triggers a cascade of cellular processes leading to the activation of lipogenesis machinery for lipid production (Fig. 1). This discovery has major implications for developing treatments for human diseases such as cancers and metabolic syndromes, as dysregulated metabolism is a hallmark of these diseases.

关键词： ammonia metabolism Ammonia

Transaction costs for collaboration in the watershed management of the Cuyahoga River Area of Concern

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Regional Sustainability 2022年第2期3卷 146-156页

作者： scott Daniel HARDY Ohio Sea Grant The Ohio State UniversityColumbus43212USA

This study examines the transaction costs of collaborative watershed management in the Cuyahoga River Area of Concern(AOC)—one of the 43 geographic areas designated by the *** Canada Great Lakes Water Quality Agreement(GLWQA),where significant impairment of beneficial uses has occurred as a result of human *** Cuyahoga River is located in Northeast Ohio,the *** flows through the City of Cleveland before draining into Lake Erie—one of the five Great Lakes of North *** watershed is degraded due to municipal and agricultural discharges,streambank erosion,and contamination from urban and industrial *** research explores how a diverse group of stakeholders convened under the Cuyahoga River AOC Advisory Committee to share information,coordinate activities,agree on activities that restore beneficial uses,and support strategic management *** this study,23 semi-structured interviews with members of the advisory committee were conducted between January 28,2020 and April 20,2020,with follow-up emails and phone calls as needed to corroborate information.A review of research articles and government documents supported the interviews,including United States Environmental Protection Agency(***)and Ohio Environment Production Agency(OEPA)reports on the GLWQA and Cuyahoga River Remedial Action Plans.A third source of data is from direct participant observation at quarterly meetings of the advisory committee during 2017–2020,binational AOC conferences in 2017 and 2019,and other professional events geared towards restoring the Cuyahoga River AOC in 2016–*** of this study include a set of recommendations to help guide group structure and decision-making processes,including(1)employing best available technology to organize AOC events and disseminate information;(2)supporting new members with an orientation and/or mentor to clearly define formal and informal committee rules;(3)assuring equal access to detailed information on managem

关键词： Environmental policy Watershed management Transaction costs Collaboration Sustainability Great Lakes

A generalized ODE susceptible-infectious-susceptible compartmental model with potentially periodic behavior

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Infectious Disease Modelling 2023年第4期8卷 1190-1202页

作者： scott Greenhalgh Anna Dumas Department of Mathematics Siena College515 Loudon RoadLoudonvilleNY12211USA

Differential equation compartmental models are crucial tools for forecasting and analyzing disease *** these models,those dealing with only susceptible and infectious individuals are particularly useful as they offer closed-form expressions for solutions,namely the logistic ***,the logistic equation has limited ability to describe disease trajectories since its solutions must converge monotonically to either the diseasefree or endemic equilibrium,depending on the ***,many diseases exhibit periodic cycles,and thus,do not converge to *** address this limitation,we developed a generalized susceptible-infectious-susceptible compartmental model capable of accurately incorporating the duration of infection distribution and describing both periodic and non-periodic disease *** characterized how our model's parameters influence its behavior and applied the model to predict gonorrhea incidence in the US,using Akaike Information Criteria to inform on its merit relative to the traditional SIS *** significance of our work lies in providing a novel susceptible-infectedsusceptible model whose solutions can have closed-form expressions that may be periodic or non-periodic depending on the *** work thus provides disease modelers with a straightforward way to investigate the potential periodic behavior of many diseases and thereby may aid ongoing efforts to prevent recurrent outbreaks.

关键词： Infectious period Duration of infection Gonorrhea Integral equations Differential equations

A Generic Model to Estimate Wheat LAI over Growing Season Regardless of the Soil-Type Background

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Plant Phenomics 2023年第2期5卷 333-352页

作者： Qiaomin Chen Bangyou Zheng Karine Chenu scott C.Chapman School of Agriculture and Food Sciences The University of QueenslandSt LuciaQLDAustralia Agriculture and Food CSIROQueensland Bioscience PrecinctSt LuciaQLDAustralia The University of Queensland Queensland Alliance for Agriculture and Food InnovationToowoombaQLDAustralia

It is valuable to develop a generic model that can accurately estimate the leaf area index(LAI)of wheat from unmanned aerial vehicle-based multispectral data for diverse soil backgrounds without any ground *** achieve this objective,2 strategies were investigated to improve our existing random forest regression(RFR)model,which was trained with simulations from a radiative transfer model(PROSAIL).The 2 strategies consisted of(a)broadening the reflectance domain of soil background to generate training data and(b)finding an appropriate set of indicators(band reflectance and/or vegetation indices)as inputs of the RFR *** RFR models were tested in diverse soils representing varying soil types in *** analysis indicated that adopting both strategies resulted in a generic model that can provide accurate estimation for wheat LAI and is resistant to changes in soil *** validation on 2 years of field trials,this model achieved high prediction accuracy for LAI over the entire crop cycle(LAI up to 7 m^(2)m^(−2))(root mean square error(RMSE):0.23 to 0.89 m^(2)m^(−2)),including for sparse canopy(LAI less than 0.3 m^(2)m^(−2))grown on different soil types(RMSE:0.02 to 0.25 m^(2)m^(−2)).The model reliably captured the seasonal pattern of LAI dynamics for different treatments in terms of genotypes,plant densities,and water–nitrogen managements(correlation coefficient:0.82 to 0.98).With appropriate adaptations,this framework can be adjusted to any type of sensors to estimate various traits for various species(including but not limited to LAI of wheat)in associated disciplines,e.g.,crop breeding,precision agriculture,etc.

关键词： soil Wheat breeding

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热气球升空

环球科学 2024年第12期 60-61页

作者：斯科特·达特菲尔德彭昶(译) 不详

热气球在天空中翱翔的科学原理很简单:热空气上升。为了利用这个原理,热气球上配备了强劲的燃烧器。当燃烧器启动时,会加热球囊内的空气。空气分子热运动加剧,分子之间的间距随之增大,从而导致球囊内部空气膨胀。由此,我们便得到了比周... 详细信息

热气球在天空中翱翔的科学原理很简单:热空气上升。为了利用这个原理,热气球上配备了强劲的燃烧器。当燃烧器启动时,会加热球囊内的空气。空气分子热运动加剧,分子之间的间距随之增大,从而导致球囊内部空气膨胀。由此,我们便得到了比周围冷空气密度要小的热空气团。

关键词：分子热运动热气球科学原理燃烧器热空气球囊冷空气

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外星也有四季吗?

环球科学 2024年第10期 74-77页

作者：斯科特·达特菲尔德庞玮(译) 不详

每三个月地球就会发生一次季节的轮换,一个月前还是阳光明媚的夏日,一个月后已是寒露渐生的秋天。实际上,太阳系中所有围绕太阳公转的星球,其表面都会呈现规律的季节更迭。地球每365天绕太阳公转一周的同时还沿地轴自转,赤道面与黄道面... 详细信息

每三个月地球就会发生一次季节的轮换,一个月前还是阳光明媚的夏日,一个月后已是寒露渐生的秋天。实际上,太阳系中所有围绕太阳公转的星球,其表面都会呈现规律的季节更迭。地球每365天绕太阳公转一周的同时还沿地轴自转,赤道面与黄道面(地球绕太阳公转的轨道平面)间有一个23.5°的倾角,这个倾角决定了地球围绕太阳公转过程中,阳光照射南北半球的角度是有差异的。

关键词：轨道平面南北半球赤道面黄道面公转阳光照射

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登上最大太阳能船

环球科学 2024年第10期 60-61页

作者：斯科特·达特菲尔德彭昶(译) 不详

在2010年3月,数百人聚集在德国基尔市的一处码头上,一起见证一艘太阳能动力双体船一图图兰星球太阳能号(Turanor Planet Solar)的首次亮相。这艘船在亮相不久后就开启了它的首次环球航行,历时584天,跨越了60022千米,在六个大洲的码头留... 详细信息

在2010年3月,数百人聚集在德国基尔市的一处码头上,一起见证一艘太阳能动力双体船一图图兰星球太阳能号(Turanor Planet Solar)的首次亮相。这艘船在亮相不久后就开启了它的首次环球航行,历时584天,跨越了60022千米,在六个大洲的码头留下了足迹,创造了太阳能动力船的最长航行纪录。这艘双体船没有使用传统的化石能源发动机,而是完全依靠太阳能驱动。船体上层覆盖着的太阳能电池板总面积达537平方米。

关键词：太阳能电池板双体船环球航行太阳能驱动化石能源码头

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深空通信

环球科学 2024年第12期 74-77页

作者：斯科特·达特菲尔德庞玮(译) 不详

科学家如何操控那些进入深空的航天器?目前有数千颗卫星和探测器在太阳系中高速飞行,地面上的科学家是如何与它们通信的呢?这项工作主要由深空网络(DSN)完成,这个由巨型射电望远镜构建起来的探测阵列不间断地监视着宇宙空间,让我们得以... 详细信息

科学家如何操控那些进入深空的航天器?目前有数千颗卫星和探测器在太阳系中高速飞行,地面上的科学家是如何与它们通信的呢?这项工作主要由深空网络(DSN)完成,这个由巨型射电望远镜构建起来的探测阵列不间断地监视着宇宙空间,让我们得以和那些飞离地球的航天器保持联系。

关键词：深空通信深空网络探测阵列探测器航天器宇宙空间太阳系高速飞行

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深入聚变反应堆

环球科学 2024年第10期 46-49页

作者：科特·达特菲尔德常潇川(译) 不详

随着目前世界上最大的托卡马克装置——日本超导先进托卡马克装置(JT-60SA)的启动,人类在核聚变技术领域又朝前迈出了一大步。该托卡马克装置位于日本国立量子科学与技术研究所,可容纳135立方米的等离子体,由欧洲聚变能组织和日本国立... 详细信息

随着目前世界上最大的托卡马克装置——日本超导先进托卡马克装置(JT-60SA)的启动,人类在核聚变技术领域又朝前迈出了一大步。该托卡马克装置位于日本国立量子科学与技术研究所,可容纳135立方米的等离子体,由欧洲聚变能组织和日本国立量子科学与技术研究所合作建造。托卡马克(tokamak)一词是俄语中“磁线圈环形真空室”的首字母缩写。与其他同类装置一样,JT-60SA的目标也是利用核聚变反应释放的能量来供能。为了实现这一点,科学家要把极高温的聚变燃料氢和气注入机器核心的甜甜圈形真空室中。

关键词：托卡马克装置核聚变反应聚变反应堆聚变燃料真空室聚变能同类装置等离子体