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Bacterial Exofactors Modulate Biofilm Growth and Resistivity to Antimicrobial Drugs

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Advances in Microbiology 2024年第1期14卷 11-24页

作者： Van Nguyen^# Bea Penaredondo^# Girdhari Rijal Department of Medical Laboratory Sciences Public Health and Nutrition Science College of Health Sciences Tarleton State University A Member of Texas A & M University System Fort Worth Texas USA

Some bacteria have the ability to co-exist, proliferate and survive in a multicellular community, biofilm. Each participating bacteria can form its colonies and encases itself by a self-produced insoluble extracellular matrix substance (EPS). Microcolonies within biofilm are held together by interactions and bonding of the substances present in the EPS with their separation from the water channels. Similar to insoluble EPS, bacterial microcolonies release soluble exofactors that have direct impacts on the survivability, growth and antibacterial resistivity of other microcolonies made of single- or multi-species bacteria in the same biofilm. How the exofactors of microcolonies of one-type bacteria impact on microcolonies of other-type bacteria is still unclear. We studied about the role of exofactors released from Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, which are common biofilm-forming pathogenic bacteria. Exofactors facilitate to transform the microenvironment where bacteria can acquire alternative lifestyle with a long survival period and resistivity to certain antimicrobial drugs.

关键词： Biofilm Exofactors Antimicrobial Drugs Growth Extracellular Matrix Substance Microcolonies

Investigating Stability Properties for Transition Metal Carbonate Precursors Using Universal Cluster Expansion Technique(UNCLE)as Cathodes for Li-Ion Batteries

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材料科学与工程（中英文A版） 2024年第1期14卷 26-33页

作者： Mogahabo Tebogo Morukuladi N.L.Lethole M.C.Masedi N.N.Ngoepe P.E.Ngoepe Materials Modelling Centre University of LimpopoPrivate Bag x1106Sovenga 0727South Africa Department of Physics University of Fort HareAlice 5700South Africa

The universal cluster expansion technique was used in this study to determine the binary phase diagrams for the transition metal carbonate precursors MCO3(M:Mn,Ni,Co).The use of mixed cathode materials in lithium-ion batteries such as NMC(Ni,Mn and Co)formulations,is a strategic approach to optimize performance,enhance safety and address cost and environmental considerations in the rapidly evolving field of energy *** study focuses on the cost issue related to lithium ion batteries by investigating the manganese rich NMC since manganese is more abundant and *** doped MnCO3 with nickel and doped MnCO3 with cobalt then ran cluster expansion calculations to generate binary *** binary phase diagrams generated indicated that doping MnCO3 with nickel favours the Mn-rich side,while doping MnCO3 with cobalt favours 50%Mn-rich and 50%*** further extracted the most stable structures from both binary diagrams and determined their electronic,mechanical and vibrational stabilities using DFT(density functional theory)calculations within the LDA(local gradient approximation)with Hubbard parameter(U).The electronic properties revealed that both materials are semiconductors due to their narrow energy band gap obtained while the mechanical properties showed that structures are mechanically stable since their necessary conditions for trigonal and triclinic systems were satisfied.

关键词： Binary phase diagrams mechanical properties electronic conductivity phonon dispersion curves.

Correlation Analysis of Energy Consumption of Agricultural Rotorcraft

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Computers, Materials & Continua 2022年第5期71卷 3179-3192页

作者： Lihua Zhu Zhijian Xu Yu Wang Cheire Cheng School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China Department of Electrical and Electronic Engineering Colorado State UniversityFort CollinsUSA

With the rapid development of unmanned aerial vehicle technology,unmanned aerial vehicles(UAVs)have been widely used in the field of agricultural plant *** with fuel-driven UAVs,electrically driven rotorcrafts have many advantages such as lower cost,simpler operation,good maneuverability and cleaner power,which them popular in the plant ***,electrical rotorcrafts still face battery problems in actual operation,which limits its working time and *** at this issue,this paper studied the influence of rotorcraft flight parameters on energy consumption through series of carefully designed flight *** of all,the linear motion experiments have been designed that the rotorcraft was made to perform speed tests and acceleration test with the speed varied from 2∼9 m/***,the turning maneuver experiments are carried out under the different circular routes,a rotorcraft was made to conduct successive steering maneuvers at a certain speed of 2 m/*** the collected tests data,the relation of the energy consumption and the flight dynamic parameter are analyzed through correlation analysis,and the test results of different pairs of experiments have been *** research results of this paper would encourage the agricultural rotorcraft to make less maneuvers during operation,which can also provide practical experience and data support for subsequent optimization of flight parameters and reduction of energy consumption.

关键词： Plant protection UAV energy consumption correlation analysis flight speed flight maneuver

Control Policy Learning Design for Vehicle Urban Positioning via BeiDou Navigation

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Journal of Systems Science & Complexity 2024年第1期37卷 114-135页

作者： QIN Yahang ZHANG Chengye CHEN Ci XIE Shengli LEWIS Frank L School of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong Key Laboratory of IoT Information Technology Guangzhou 510006China. Center for Intelligent Batch Manufacturing Based on IoT Technology Key Laboratory of Intelligent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint Laboratory for Smart Discrete Manufacturing Guangzhou 510006China Key Laboratory of Intelligent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a learning-based control policy design for point-to-point vehicle positioning in the urban environment via BeiDou *** navigating in urban canyons,the multipath effect is a kind of interference that causes the navigation signal to drift and thus imposes severe impacts on vehicle localization due to the reflection and diffraction of the BeiDou ***,the authors formulated the navigation control system with unknown vehicle dynamics into an optimal control-seeking problem through a linear discrete-time system,and the point-to-point localization control is modeled and handled by leveraging off-policy reinforcement learning for feedback *** proposed learning-based design guarantees optimality with prescribed performance and also stabilizes the closed-loop navigation system,without the full knowledge of the vehicle *** is seen that the proposed method can withstand the impact of the multipath effect while satisfying the prescribed convergence rate.A case study demonstrates that the proposed algorithms effectively drive the vehicle to a desired setpoint under the multipath effect introduced by actual experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation multipath effect prescribed convergence rate reinforcement learning urban localization.

Synthesis and measurement of structural and magnetic properties of K-doped LaCoO_3 perovskite materials

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Rare Metals 2010年第5期29卷 491-500页

作者： Manjunath B.Bellakki C.Madhu Tobias Greindl Sandeep Kohli Patrick McCurdy V.Manivannan Department of Mechanical Engineering Colorado State UniversityFort CollinsColoradoUSA Department of Chemistry Colorado State UniversityFort CollinsColoradoUSA

Polycrystalline La1-xKxCoO3 （0≤ x ≤ 0.2） rare earth cobaltates have been synthesized by a solution combustion method using glycine as a fuel. The synthesized ceramic materials were characterized by powder X-ray diffraction （XRD）, scanning electron microscopy （SEM）, Fourier transform infrared spectroscopy （FTIR）, and magnetic measurements and studied for physical properties, such as photoeatalytic activity. FTIR measurements in conjunction with XRD showed that phases beyond 10% K doping are accompanied by small amounts of impurities. Chemical titrations show the presence of Co^4＋ and account for the Co^3＋-Co^4＋ mixed-valency of the system. The parent LaCoO3 shows spin-glass transition at low temperatures, whereas doped samples show transition from spin-glass behavior to paramagnetic ordering on progressive doping of K. ＂Mixed-conductor＂ nature of these ceramics positions them as viable candidates for solid oxide fuel cell （SOFC） applications.

关键词： ceramic materials combustion synthesis X-ray diffraction magnetic properties structural properties

Seasonal influence of freshwater discharge on spatio-temporal variations in primary productivity, sea surface temperature, and euphotic zone depth in the northern Bay of Bengal

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Acta Oceanologica Sinica 2024年第6期43卷 1-14页

作者： Hafez Ahmad Felix Jose Md.Simul Bhuyan Md.Nazrul Islam Padmanava Dash Geosystems Research Institute/Department of Geosciences Mississippi State UniversityStarkville 39759USA Department of Oceanography University of ChittagongChittagong 4331Bangladesh Department of Marine&Earth Sciences Florida Gulf Coast UniversityFort Myers 33965USA Bangladesh Oceanographic Research Institute Cox’s Bazar 4730Bangladesh Faculty of Marine Sciences&Fisheries Institute of Marine SciencesUniversity of ChittagongChittagong 4331Bangladesh Department of Geography and Environment Jahangirnagar UniversityDhaka 1342Bangladesh Department of Geosciences Mississippi State UniversityStarkville 39759USA

Ocean productivity is the foundation of marine food web,which continuously removes atmospheric carbon dioxide and supports life at sea and on ***-temporal variability of net primary productivity(NPP),sea surface temperature(SST),sea surface salinity(SSS),mixed layer depth(MLD),and euphotic zone depth(EZD) in the northern B ay of Bengal(BoB) during three monsoon seasons were examined in this study based on remote sensing data for the period 2005 to *** compare the NPP distribution between the coastal zones and open BoB,the study area was divided into five zones(Z1-Z5).Results suggest that most productive zones Z2 and Zl are located at the head bay area and are directly influenced by freshwater discharge together with riverine sediment and nutrient *** Z1-Z5,the NPP ranges from 5 315.38 mg/(m^(2)·d) to 346.7 mg/(m^(2)·d)(carbon,since then the same).The highest monthly average NPP of 5 315.38 mg/(m^(2)·d) in February and 5 039.36 mg/(m^(2)·d) in June were observed from Z2,while the lowest monthly average of 346.72 mg/(m^(2)·d) was observed in March from Z4,which is an oceanic *** values vary from 6-154 m for the study area,and it has an inverse correlation with NPP *** is deeper during the summer season and shallower during the wintertime,with a corresponding increase in *** the year,monthly SST shows slight fluctuation for the entire study area,and statistical analysis shows a significant correlation among NPP,and EZD,overall positive between NPP and MLD,whereas no significant correlation among SSS,and SST for the northern ***-term trends in SST and productivity were significantly po sitive in head bay zones but negatively productive in the open *** findings in this study on the distribution of NPP,SST,SSS,MLD,and EZD and their seasonal variability in five different zones of BoB can be used to further improve the management of marine resources and overall environmental condition in response to clim

关键词： chlorophyll a sea surface temperature euphotic zone depth primary productivity Ganges-Brahmaputra ocean color Bay of Bengal monsoon

How will climate change affect the potential distribution of Eurasian tree sparrows Passer montanus in North America？

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Current Zoology 2011年第5期57卷 648-654页

作者： Jim GRAHAM Catherine JARNEVICH Nick YOUNG Greg NEWMAN Thomas STOHLGREN Natural Resource Ecology Laboratory Colorado State University Fort Collins CO 80523-1499 USA fort collins Science Center U.S. Geological Survey 2150 Centre Ave. Building C Fort Collins CO 80526 USA

Habitat suitability models have been used to predict the present and future potential distribution of a variety of species. Eurasian tree sparrowsPasser montanus, native to Eurasia, have established populations in other parts of the world. In North America, their current distribution is limited to a relatively small region around its original introduction to St. Louis, Missouri. We combined data from the Global Biodiversity Information Facility with current and future climate data to create habitat suitability models using Maxent for this species. Under projected climate change scenarios, our models show that the distribution and range of the Eurasian tree sparrow could increase as far as the Pacific Northwest and Newfoundland. This is potentially important information for prioritizing the management and control of this non-native species.

关键词：气候变化影响树麻雀北美生境适宜性生物多样性西北太平洋欧亚大陆电流分布

Scaling diode-pumped, high energy picosecond lasers to kilowatt average powers

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High Power Laser Science and Engineering 2018年第1期6卷 67-75页

作者： Brendan A.Reagan Cory Baumgarten Elzbieta Jankowska Han Chi Herman Bravo Kristian Dehne Michael Pedicone Liang Yin Hanchen Wang Carmen S.Menoni Jorge J.Rocca Department of Electrical and Computer Engineering Colorado State University Fort Collins CO 80523 USA XUV Lasers Inc. PO Box 273251 Fort Collins CO 80527 USA Department of Physics Colorado State University Fort Collins CO 80523 USA

Recent results in the development of diode-driven high energy, high repetition rate, picosecond lasers, including the demonstration of a cryogenic Yb:YAG active mirror amplifier that produces 1.5 J pulses at 500 Hz repetition rate(0.75 kW average power) are reviewed. These pulses are compressed resulting in the generation of ~5 ps duration,1 J pulses with 0.5 kW average power. A full characterization of this high power cryogenic amplifier, including atwavelength interferometry of the active region under >1 kW average power pump conditions, is presented. An initial demonstration of operation at 1 kW average power(1 J, 1 k Hz) is reported.

关键词： advanced laser technology and applications diode-pumped solid-state laser and applications high power laser high power laser related laser components laser amplifiers

Applications of GSTARS Computer Models for Solving River and Reservoir Sedimentation Problems

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Transactions of Tianjin University 2008年第4期14卷 235-247页

作者： YANG Chih Ted Colorado State University Fort Collins

GSTARS (Generalized Sediment Transport model for Alluvial River Simulation) is a series of computer models developed by the U.S. Bureau of Reclamation while the author was employed by that agency. The stream tube concept is used in all GSTARS models which allow us to solve one-dimensional equations for each stream tube independently and obtain semi-two-dimensional variation of the hydraulic conditions along and across stream tubes for rivers and reservoirs. Sedi-ment transport, scour, and deposition processes are simulated along each stream tube independently to give us a semi-three-dimensional variation of the bed geometry. Most sediment transport computer models assume that channel width is given and cannot change during the simulation process. GSTARS models apply the theory of minimum stream power to the determination of optimum channel width and channel geometry. The concepts of channel side stability, and active, inactive, and armoring layers are used in all GSTARS models for realistic long-term simulation and prediction of the scour and deposition processes in rivers and *** models have been applied in many countries for solving a wide range of river and reservoir sedimentation problems. Case studies will be used to illustrate the applications of GSTARS computer models.

关键词：水库河流土砂流送计算机模型