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Sex-dependent resilience to extreme drought events: implications for climate change adaptation of a South American endangered tree species

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Ecological Processes 2024年第2期13卷 48-60页

作者： Sergio Piraino Martín ariel Hadad Yanina Antonia Ribas-Fernández Fidel Alejandro Roig Laboratorio de Dendrocronología e Historia Ambiental (IANIGLA CONICET ) Facultad de Ciencias Agrarias Universidad Nacional de Cuyo Laboratorio de Dendrocronología de Zonas áridas (CIGEOBIO CONICET ) Gabinete de Geología Ambiental (INGEO UNSJ) Hémera Centro de Observación de la Tierra Facultad de Ciencias Universidad Mayor

Background Recent changes in climatic trends are resulting in an increased frequency and intensity of extreme events, with unknown effect on ecosystem dynamics in the near future. Extreme drought episodes are recognized as disturbance factors capable of modifying forest dynamics and tree growth. Within this context, dioecious tree species may be impacted by climatic extremes, affecting male/female proportions and, consequently, reproductive processes and species persistence. Therefore, there is an urgent need for species-specific assessments of growth tolerance to extreme dry spells in dioecious tree species, to establish effective conservation strategies for these particular natural resources. Araucaria araucana(araucaria), an endangered dioecious Patagonian tree species, has recently undergone decay and mortality episodes in response to increasing dry climatic conditions. While sex-dependent tolerance to extreme drought episodes has been assessed in the species' humid distribution range, there is still a lack of information on the gender-based resilience of trees growing in the drier environments of the species' *** We reconstructed, through dendrochronological methods, the sex-dependent response of 105 araucaria individuals(55 female and 50 male trees) to five regional extreme dry spells employing a set of different indices. Resistance, recovery period, and average growth reduction of standardized tree-ring growth were examined, analysing the effect of biotic(sex, pre-drought stem tree growth) and abiotic(local climatic conditions before, during, and after extreme climatic episodes) factors on tree *** Sex influences only the species resistance to climatic disturbance, with male individuals showing lower tolerance to extreme drought events. Pre-drought radial growth rates and local meteorological conditions preceding, during, and following extreme dry spells strongly modulated araucaria radial growth resilience regardless of tree s

关键词： Araucaria Climate change Dendrochronology Extreme drought event Resilience

DEM analysis of the influence of stirrer design on die filling with forced powder feeding

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Particuology 2024年第5期88卷 107-115页

作者： Chao Zheng Edward Yost ariel R.Muliadi Nicolin Govender Ling Zhang Chuan-Yu Wu School of Chemistry and Chemical Engineering University of SurreyGuildfordGU2 7XHUnited Kingdom Small Molecule Pharmaceutics GenentechInc.One DNA WaySouth San FranciscoCA94080USA

Die filling is a critical stage during powder compaction,which can significantly affect the product quality and *** this paper,a forced feeder is introduced attempting to improve the filling performance of a lab-scale die filling *** die filling process is analysed with a graphics processing units(GPU)enhanced discrete element method(DEM).Various stirrer designs are assessed for a wide range of process settings(i.e.,stirrer speed,filling speed)to explore their influence on the die filling performance of free-flowing *** results show that die filing with the novel helical-ribbon(i.e.,type D)stirrer design exhibits the highest filling ratio,implying that it is the most robust stirrer design for the feeder configuration ***,die filling performance with the type D stirrer design is a function of the stirrer speed and the filling speed.A positive variation of filling ratio(ηf>0%)can be ensured over the whole range of filling speed by adjusting the stirrer speed(i.e.,increasing the stirrer speed).The approach used in this study can not only help understand how the stirrer design affects the die filling performance but also guide the optimization of feeder system and process settings.

关键词： Discrete element method Die filling Forced feeding Stirrer design GPU computing

Elements of Electromagnetic Matter

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Journal of Modern Physics 2024年第3期15卷 250-270页

作者： Viktor ariel Independent Researcher Modiin Israel

Originally, Maxwell attempted to express his electromagnetic theory using four-dimensional mathematics of quaternions. Maxwell’s equations were later re-written in a three-dimensional real vector form, which is how the theory is presented today. Thus, an interesting question remains whether we can derive electromagnetic equations analytically from the basic mathematical principles of quaternion algebra and calculus, resulting in general and analytic matter equations. This question seems highly intriguing. Previously, we developed a mathematical theory of time using a normed division algebra of real quaternions [1]. In this study, we extend the theory of time by presenting a new analytical derivation of electromagnetic matter equations using the calculus of real quaternions, as originally intended by Maxwell. Therefore, we propose a novel mathematical definition of the quaternion path derivative using the properties of quaternion division. We then apply the quaternion derivative to an external electromagnetic potential and assume that the first quaternion derivative represents the quaternion electromagnetic force. Next, we assume that the second derivative, or quaternion Laplacian operator, applied to an external electromagnetic potential leads to the quaternion electromagnetic current density. The new analytical expressions are similar to the original empirical Maxwell equations, except for an additional scalar electric field, which allows for a novel formulation of Ohm’s conductivity law. We demonstrate that the resulting analytical equations can be written equivalently using either electromagnetic potentials or fields. Finally, we summarize the key postulates and equations of the new electromagnetic matter theory, which were based on normed division algebra and the calculus of quaternions. The resulting theory appears to be a useful analytical enhancement of the original Maxwell equations, and therefore, seems highly comprehensive, logical, and compelling.

关键词： Maxwell’s Equations Relativistic Electrodynamics Quaternion Calculus

Extreme drought triggers parallel shifts in wood anatomical and physiological traits in upper treeline of the Mediterranean Andes

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Ecological Processes 2024年第1期13卷 132-143页

作者： Luiz Santini Jr. Dylan Craven Daigard Ricardo Ortega Rodriguez Manolo Trindade Quintilhan Stephanie Gibson-Carpintero Cristina Aravena Torres Fidel A.Roig ariel A.Mu?oz Alejandro Venegas-Gonzalez Hémera Centro de Observación de la Tierra Universidad Mayor GEMA Center for Genomics Ecology and Environment Universidad Mayor Data Observatory Foundation ANID Technology Center Depart-ment of Forest Sciences ESALQ-University of Sao Paulo Department of Plant Biology Institute of Biology University of Campinas Instituto de Geografía Universidad Nacional Autónoma de México (UNAM) Argentine Institute of Nivology Glaciology and Environmental Sciences(IANIGLA CONICET ) Institute of Geography Pontificia Universidad Católica de Valparaíso Instituto de Ciencias Agroalimentarias Animales y Ambientales (ICA3) Universidad de O'Higgins

Background Treeline ecotones of Mediterranean ecoregions have been affected by the increasing intensity and severity of droughts. Even though the effect of droughts on forest dynamics has been widely documented, knowledge is relatively scarce of how extreme climate episodes affect the hydraulic structure and, therefore, the phys-iology of woody plants. The Mediterranean Andes have experienced an uninterrupted period of drought since 2010, including an extremely dry year in 2019 with approximately 80% rainfall deficit. Here, we investigated shifts in wood anatomical and physiological traits of Kageneckia angustifolia, an endemic treeline species, in response to this drought *** We evaluated the xylem plasticity of three K. angustifolia populations across their natural distribution(31–35° SL) based on anatomical(vessel structure and distribution) and physiological(intrinsic water-use efficiency) variables in the tree rings. We focused on the period 2000–2020 that corresponds to before the megadrought(2000–2007),(ii) megadrought(2008–2018) and(iii) hyperdrought(2019–2020). The variables were annualized and analyzed by linear mixed-effects *** Our results provide insights to the anatomical and physiological mechanisms underlying the resilience of treeline forests to persistent droughts in central Chile. We found that the extreme drought in 2019–2020 triggered shifts in vessel size and frequency that increased hydraulic safety. These significant shifts in vessel traits occurred in parallel with a decrease in pit aperture area and an increase in water-use efficiency, further increasing the resilience of K. angustifolia to extreme drought *** Our results revealed coordinated shifts in vessel size and frequency and water-use efficiency in response to the megadrought, thereby reducing vulnerability to hydraulic failure. The apparent resilience of K. angustifolia to extreme droughts suggests that this adaptation to drought stress may incre

关键词： Dendro-anatomy Kageneckia angustifolia Xylem vulnerability Drought Climate change

利用21CMA射电低频阵聆听来自轴子暗物质的回响（英文）

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Science Bulletin 2024年第19期69卷 2971-2973页

作者： ariel Arza 郭铨武雷杨峤立杨小龙袁强祝斌 Department of Physics and Institute of Theoretical Physics Nanjing Normal University Shanghai Astronomical Observatory Chinese Academy Sciences College of Physics and Optoelectronic Engineering Department of PhysicsJinan University Shanghai Key Laboratory of Space Navigation and Positioning Techniques Key Laboratory of Dark Matter and Space Astronomy Purple Mountain ObservatoryChinese Academy of Sciences School of Astronomy and Space Science University of Science and Technology of China Department of Physics Yantai University

The axion is nowadays one of the leading candidates to compose the dark matter of the universe.A great experimental effort has been performed by the so-called axion haloscopes experiments among others (for complete reviews on updated axion phenomenology,see Ref.[1]).In this paper,we take the new axion dark matter echo idea proposed in Ref.[2].This technique aims to send out of space a powerful beam of electromagnetic radiation in the radio/microwave frequency range and search for the electromagnetic echo produced by stimulated decay of ambient axion dark matter.

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An Assessment on the Impact of Technological Addiction on Workplace Productivity: Case of the Public Sector in Zimbabwe

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World Journal of Engineering and Technology 2024年第3期12卷 635-650页

作者： Nelson Matanana Prosper Tafadzwa Denhere David Chibhoyi Allen Mutumwa Sithole Morgen Noah ariel Mutongoreni Department of Computer Science and Information Systems at Manicaland State University of Applied Sciences Mutare Zimbabwe Department of Human Resources Management at Manicaland State University of Applied Sciences Mutare Zimbabwe Department of Applied Business Sciences at Manicaland State University of Applied Sciences Mutare Zimbabwe

With the increasing integration of technology in modern workplaces, concerns have emerged regarding the addictive nature of technology and its potential consequences on employee productivity. This research aims to investigate the impact of technological addiction on workplace productivity within the public sector of Zimbabwe. The study employed a mixed-methods approach, combining surveys, interviews, and a case study analysis, to examine the prevalence and effects of technological addiction in affecting productivity in the public sector of Zimbabwe. The findings indicate that excessive use of social media, and other digital distractions is a growing concern in the public sector, leading to decreased focus, missed deadlines, and strained teamwork. Factors such as unrestricted internet access, lack of clear usage policies, and inadequate self-regulation contribute to the problem The research outcomes also highlight the need for awareness and interventions to address social media addiction in the workplace, promote healthier technology use, and uphold productivity and employee well-being.

关键词： Technology Addiction Workplace Productivity Technology Public Sector Zimbabwe

Comparative Analysis of Statistical Thickness Models for the Determination of the External Specific Surface and the Surface of the Micropores of Materials: The Case of a Clay Concrete Stabilized Using Sugar Cane Molasses

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Geomaterials 2024年第2期14卷 13-28页

作者： Nice Mfoutou Ngouallat Narcisse Malanda Christ ariel Ceti Malanda Kris Berjovie Maniongui Erman Eloge Nzaba Madila Paul Louzolo-Kimbembe Mechanics Energy and Engineering Laboratory Higher National Polytechnic School Marien Ngouabi University Brazzaville Republic of the Congo National Institute for Research in Engineering Sciences Innovation and Technology (INRSIIT) Brazzaville Republic of the Congo Higher Institute of Architecture Building Planning and Public Works Denis SASSOU N&#8217GUESSO University Kint&#233l&#233 Republic of the Congo Hydrogen Research Institute University of Quebec in Trois Rivieres Quebec Canada Superior Normal School (ENS) Marien Ngouabi University Brazzaville Republic of the Congo

In this work, four empirical models of statistical thickness, namely the models of Harkins and Jura, Hasley, Carbon Black and Jaroniec, were compared in order to determine the textural properties (external surface and surface of micropores) of a clay concrete without molasses and clay concretes stabilized with 8%, 12% and 16% molasses. The results obtained show that Hasley’s model can be used to obtain the external surfaces. However, it does not allow the surface of the micropores to be obtained, and is not suitable for the case of simple clay concrete (without molasses) and for clay concretes stabilized with molasses. The Carbon Black, Jaroniec and Harkins and Jura models can be used for clay concrete and stabilized clay concrete. However, the Carbon Black model is the most relevant for clay concrete and the Harkins and Jura model is for molasses-stabilized clay concrete. These last two models augur well for future research.

关键词： Statistical Thickness Model External Specific Surface Microporous Surface Clay Concrete Molasses

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通用汽车想为车载系统另起炉灶

商业周刊（中文版） 2024年第7期 56-61页

作者： AUSTIN CARR DAVID WELCH ariel DAVIS(图) 汪泽(译) 不详

2024款雪佛兰开拓者EV(Chevrolet Blazer EV)是迈克尔·沃尔德伦(Michael Waldron)拥有过的最漂亮的座驾。他去年11月购买了这辆6.2万美元的电动SUV,深深地迷上了它的“炫红”色彩,丝滑流畅的加速以及豪华的内饰,简洁的显示屏排列在仪... 详细信息

2024款雪佛兰开拓者EV(Chevrolet Blazer EV)是迈克尔·沃尔德伦(Michael Waldron)拥有过的最漂亮的座驾。他去年11月购买了这辆6.2万美元的电动SUV,深深地迷上了它的“炫红”色彩,丝滑流畅的加速以及豪华的内饰,简洁的显示屏排列在仪表盘上。只是少了一样重要事物:苹果公司(Apple)的CarPlay。

关键词：车载系统仪表盘座驾通用汽车内饰 SUV 苹果公司沃尔德

Waveform LiDAR concepts and applications for potential vegetation phenology monitoring and modeling:a comprehensive review

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Geo-Spatial Information Science 2021年第2期24卷 179-200,I0001页

作者： Eric ariel L Salas Agricultural Research Development Program(ARDP) Central State UniversityWilberforceUSA

Researchers continually demonstrated through published literature how LiDAR could create unparalleled measurements of ecosystem structure and forest *** are a number of studies conducted utilizing waveform LiDAR products for terrestrial monitoring,but those that deal specifically with the assessment of space-borne waveform LiDAR for monitoring and modeling of phenology is very *** review highlights the waveform LiDAR system and looks into satellite sensors that could link waveform LiDAR and vegetation phenology,such as the proposed NASA’s Global Ecosystem Dynamics Investigation(GEDI)and the Japanese Experimental Module(JEM)-borne LiDAR sensor named MOLI(Multi-footprint Observation LIDAR and Imager).Further,this work examines the richness and utility of the waveform returns and proposes a spline-function-derived model that could be exploited for estimating the leaf-shooting *** new approach may be utilized for ecosystem-level phenological studies.

关键词： Ecosystems gedi moli phenology vegetation modeling waveform LiDAR