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Biophysical warming patterns of an open-top chamber and its short-term influence on a Phragmites wetland ecosystem in China

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China Geology 2023年第4期6卷 594-610页

作者： Xue-yang Yu Si-yuan Ye Li-xin Pei Liu-juan Xie ken W.krauss samantha k.Chapman Hans Brix key Laboratory of Coastal Wetland Biogeosciences Qingdao Institute of Marine GeologyChina Geological SurveyMinistry of Natural ResourcesQingdao 266071China Institute of Marine Science and Technology Shandong UniversityQingdao 266237China Wetland and Aquatic Research Center U.S.Geological SurveyLafayette 70506United States of America Department of Biology Villanova UniversityVillanova 19085United States of America Department of Biology Aarhus UniversityAarhus 8000CDenmark

Passive-warming, open-top chambers(OTCs) are widely applied for studying the effects of future climate warming on coastal wetlands. In this study, a set of six OTCs were established at a Phragmites wetland located in the Yellow River Delta of Dongying City, China. With data collected through online transmission and in-situ sensors, the attributes and patterns of realized OTCs warming are demonstrated.The authors also quantified the preliminary influence of experimental chamber warming on plant traits.OTCs produced an elevated average air temperature of 0.8°C(relative to controls) during the growing season(June to October) of 2018, and soil temperatures actually decreased by 0.54°C at a depth of 5 cm and 0.46°C at a depth of 30 cm in the OTCs. Variations in diel patterns of warming depend greatly on the heat sources of incoming radiation in the daytime versus soil heat flux at night. Warming effects were often larger during instantaneous analyses and influenced OTCs air temperatures from-2.5°C to 8.3°C dependent on various meteorological conditions at any given time, ranging from cooling influences from vertical heat exchange and vegetation to radiation-associated warming. Night-time temperature depressions in the OTCs were due to the low turbulence inside OTCs and changes in surface soilatmosphere heat transfer. Plant shoot density, basal diameter, and biomass of Phragmites decreased by23.2%, 6.3%, and 34.0%, respectively, under experimental warming versus controls, and plant height increased by 4.3%, reflecting less carbon allocation to stem structures as plants in the OTCs experienced simultaneous wind buffering. While these passive-warming OTCs created the desired warming effects both to the atmosphere and soils, pest damages on the plant leaves and lodging within the OTCs were extensive and serious, creating the need to consider control options for these chambers and the replicated OTCs studies underway in other Chinese Phragmites marshes(Panjin and Yancheng).

关键词： Open-top chambers(OTCs)warming Phragmites australis wetland Short-term ecosystem impact Climate warming Soil heat flux Soil-atmosphere heat transfer Ecological geological engineering Hydrogeological engineering Yellow River Delta

A comparison of centrifugation and tangential flow filtration for nanoparticle purification: A case study on acetalated dextran nanoparticles

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Particuology 2020年第3期18卷 189-196页

作者： Nishan k.Shah Ryan Ivone Jie Shen samantha A.Meenach University of Rhode Island College of PharmacyDepartment of Biomedical and Pharmaceutical SciencesKingstonRI 02881USA University of Rhode Island College of EngineeringDepartment of Chemical EngineeringKingstonRI 02881USA

Tangential fiow filtration (TFF) is a purification method commonly used in a multitude of fields,including particle engineering.Currently,there is still a lack of comprehensive understanding of the effects of key TFF parameters on nanoparticle (NP) characteristics (purification outcomes).The present study aimed to investigate the influence of various factors on the characteristics of TFF-purified NP.The most commonly used NP purification method,centrifugation,was studied as a control.A design of experiment approach was implemented to investigate the influence of transmembrane pressure,flow rate,and initial drug loading on NP characteristics using paclitaxel as a model small molecule.Following the determination of optimized TFF parameters,the two purification methods were assessed using other model small molecules (i.***.tacrolimus and resveratrol).The results indicated that the TFF parameters and initial loading of the drug played important roles in the purified NP outcomes.Compared with the centrifugation method,TFF resulted in smaller NP with higher drug loading.TFF was able to circumvent issues associated with conventional centrifugation,while yielding similar results,and can potentially serve as a suitable large-scale purification method for polymeric NP.

关键词： Tangential flow filtration Nanoparticle purification Box-Behnken design Acetalated dextran Drug delivery

Differential Expression of Mature MicroRNAs Involved in Muscle Maintenance of Hibernating Little Brown Bats, Myotis lucifugus: A Model of Muscle Atrophy Resistance

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Genomics, Proteomics & Bioinformatics 2012年第5期10卷 295-301页

作者： samantha F.kornfeld kyle k.Biggar kenneth B.Storey Institute of Biochemistry&Department of Biology Carleton University

Muscle wasting is common in mammals during extended periods of immobility. However, many small hibernating mammals manage to avoid muscle atrophy despite remaining stationary for long periods during hibernation. Recent research has highlighted roles for short non-coding microRNAs （miRNAs） in the regulation of stress tolerance. We proposed that they could also play an important role in muscle maintenance during hibernation. To explore this possibility, a group of 10 miRNAs known to be normally expressed in skeletal muscle of non-hibernating mammals were analyzed by RT-PCR in hibernating little brown bats, Myotis lucifugus. We then compared the expression of these miRNAs in euthermic control bats and bats in torpor. Our results showed that compared to euthermic controls, sig- nificant, albeit modest （1.2-1.6 fold）, increases in transcript expression were observed for eight mature miRNAs, including miR-la-1, miR-29b, miR-181b, miR-15a, miR-20a, miR-206 and miR-128-1, in the pectoral muscle of torpid bats. Conversely, expression of miR-21 decreased by 80% during torpor, while expression of miR-107 remained unaffected. Interestingly, these miRNAs have been either validated or predicted to affect multiple muscle-specific factors, including myostatin, FoxO3a, HDAC4 and SMADT, and are likely involved in the preservation of pectoral muscle mass and functionality during bat hibernation.

关键词： MlicroRNA Hibernation Metabolic rate depression Atrophy Dicer Myostatin

MicroRNA Regulation in Extreme Environments: Differential Expression of MicroRNAs in the Intertidal Snail Littorina littorea During Extended Periods of Freezing and Anoxia

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Genomics, Proteomics & Bioinformatics 2012年第5期10卷 302-309页

作者： kyle k.Biggar samantha F.kornfeld Yulia Maistrovski kenneth B.Storey Institute of Biochemistry&Department of Biology Carleton University

Several recent studies of vertebrate adaptation to environmental stress have suggested roles for microRNAs （miRNAs） in regulating glo- bal suppression of protein synthesis and/or restructuring protein expression patterns. The present study is the first to characterize stress- responsive alterations in the expression of miRNAs during natural freezing or anoxia exposures in an invertebrate species, the intertidal gastropod Littorina littorea. These snails are exposed to anoxia and freezing conditions as their environment constantly fluctuates on both a tidal and seasonal basis. The expression of selected miRNAs that are known to influence the cell cycle, cellular signaling pathways, carbohydrate metabolism and apoptosis was evaluated using RT-PCR. Compared to controls, significant changes in expression were observed for miR-la-1, miR-34a and miR-29b in hepatopancreas and for miR-la-1, miR-34a, miR-133a, miR-125b, miR-29b and miR-2a in foot muscle after freezing exposure at -6 ~C for 24 h （P 〈 0.05）. In addition, in response to anoxia stress for 24 h, significant changes in expression were also observed for miR-la-1, miR-210 and miR-29b in hepatopancreas and for miR-1 a-1, miR-34a, miR-133a, miR-29b and miR-2a in foot muscle （P 〈 0.05）. Moreover, protein expression of Dicer, an enzyme responsible for mature microRNA processing, was increased in foot muscle during freezing and anoxia and in hepatopancreas during freezing. Alterations in expression of these miRNAs in L. littorea tissues may contribute to organismal survival under freezing and anoxia.

关键词： Freeze tolerance Anaerobiosis Metabolic rate depression Periwinkle Marine mollusk

Physics-based modeling of crowd evacuation in the Unity game engine

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International Journal of Modeling, Simulation, and Scientific Computing 2018年第4期9卷 108-138页

作者： Walter Alan Cantrell Mikel D.Petty samantha L.knight Whitney k.Schueler University of Alabama in Huntsville 301 Sparkman Drive OKT N353Huntsville Alabama 35899United States of America

Crowds of people are often found in enclosed or constricted spaces.Evacuation in such situations is usually conducted calmly,but real or perceived danger may trigger panic.In panicked crowds,the interpersonal distance crowd members normally observe is often overwhelmed by the physical pressure of crowd members pushing against each other.That pressure can both slow evacuation and lead to injury or death.Models have been developed to study crowd evacuation in a range of situations.This paper describes the implementation,testing,and validation of a crowd evacuation model using Unity,a commercial computer game engine.A realistic physics-based model of crowd movement that calculates and considers the physical pressure crowd members exert on each other was implemented in Unity.The implemented model was tested under both nonpanicked and panicked scenarios;those tests exhibited known qualitative characteristics of such scenarios.The model was then quantitatively validated by comparing its results to the outcome of an actual evacuation event,the 2003 fire at The Station nightclub in Rhode Island.The implementation and validation show that Unity can be an effective tool for evacuation modeling.

关键词： Crowd modeling crowd movement evacuation modeling game engines Unity.

A novel two-way method for dynamically coupling a hydrodynamic model with a discrete element model(DEM)

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Journal of Hydrodynamics 2018年第5期30卷 966-969页

作者：熊焱 Qiuhua Liang samantha Mahaffey Mohamed Rouainia 王岗 State key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University School of Architecture Building and Civil Engineering Loughborough University School of Engineering Newcastle University

The effect of floating objects has so far been little considered for hazard risk assessment and structure design, despite being an important factor causing structural damage in flood-prone and coastal areas. In this work, a novel two-way method is proposed to fully couple a shock-capturing hydrodynamic model with a discrete element model （DEM） for simulation of complex debris-enriched flow hydrodynamics. After being validated against an idealized analytical test, the new coupled model is used to reproduce flume experiments of floating debris driven by dam-break waves. The numerical results agree satisfactorily with the experimental measurements, demonstrating the model＇s capability and efficiency in simulating complex fluid-debris interactions induced by violent shallow flows.

关键词： Coupled model, discrete element model （DEM） extreme hydraulic conditions floating debris shallow water equations Godunov-type finite volume method

Selective Pb^(2+) removal and electrochemical regeneration of fresh and recycled FeOOH

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Nano Research 2023年第7期16卷 9352-9363页

作者： Lei Wang Lexane Deligniere samantha Husmann Regina Leiner Carsten Bahr Shengjie Zhang Chaochao Dun Matthew M.Montemore Markus Gallei Jeffrey J.Urban Choonsoo kim Volker Presser INM—Leibniz Institute for New Materials Campus D22Saarbrücken 66123Germany Department of Materials Science and Engineering Saarland UniversityCampus D22Saarbrücken 66123Germany Polymer Chemistry Saarland UniversityCampus C42Saarbrücken 66123Germany 4 GEH Wasserchemie GmbH&Co.KGAdolf-Köhne-Straße Osnabrück 49090 Germany Department of Chemical and Biomolecular Engineering Tulane UniversityNew OrleansLA 70118USA The Molecular Foundry Lawrence Berkeley National Laboratory BerkeleyBerkeleyCA 94720USA Saarene-Saarland Center for Energy Materials and Sustainability Campus C42Saarbrücken 66123Germany Department of Environmental Engineering with Institute of Energy/Environment Convergence Technologies Kongju National University1223-24 Cheonan-daeroCheonan-si 31080Republic of Korea Department of Future Convergence Engineering Kongju National University1223-24 Cheonan-daeroCheonan-si 31080Republic of Korea

Heavy metal pollution is a key environmental problem.Selectively extracting heavy metals could accomplish water purification and resource recycling simultaneously.Adsorption is a promising approach with a facile process,adaptability for the broad concentration of feed water,and high selectivity.However,the adsorption method faces challenges in synthesizing highperformance sorbents and regenerating adsorbents effectively.FeOOH is an environmentally friendly sorbent with low-cost production on a large scale.Nevertheless,the selectivity behavior and regeneration of FeOOH are seldom studied.Therefore,we investigated the selectivity of FeOOH in a mixed solution of Co^(2+),Ni^(2+),and Pb^(2+)and proposed to enhance the capacity of FeOOH and regenerate it by using external charges.Without charge,the FeOOH electrode shows a Pb^(2+)uptake capacity of 20 mg/g.After applying a voltage of-0.2/+0.8 V,the uptake capacity increases to a maximum of 42 mg/g and the desorption ratio is 70%-80%.In 35 cycles,FeOOH shows a superior selectivity towards Pb^(2+)compared with Co^(2+)and Ni^(2+),with a purity of 97%±3%in the extracts.The high selectivity is attributed to the lower activation energy for Pb^(2+)sorption.The capacity retentions at the 5^(th)and the 35^(th)cycles are ca.80%and ca.50%,respectively,comparable to the chemical regeneration method.With industrially exhausted granular ferric hydroxide as the electrode material,the system exhibits a Pb^(2+)uptake capacity of 37.4 mg/g with high selectivity.Our work demonstrates the feasibility of regenerating FeOOH by charge and provides a new approach for recycling and upcycling FeOOH sorbent.

关键词： FeOOH electrochemical regeneration selective separation heavy metal ions

Effectiveness of BNT162b2 Vaccine against Critical Covid-19 in Adolescents

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四川生理科学杂志 2021年第10期43卷 1723-1723页

作者： samantha M Olson From the Covid-19 Response Team Centers for Disease Control and Prevention (S.M.O. A.M.P. L.D.Z. A.P.C. M.M.P.) and the Center for Childhood Infections and Vaccines of Children's Healthcare of Atlanta and the Department of Pediatrics Emory University School of Medicine (S.K.) - both in Atlanta the Department of Anesthesiology Critical Care and Pain Medicine Boston Children's Hospital (M.M.N. A.G.R.) and the Departments of Anaesthesia and Pediatrics Harvard Medical School (A.G.R.) - both in Boston the Division of Pediatric Infectious Diseases Department of Pediatrics Vanderbilt University Medical Center Nashville (N.B.H.) the Department of Pediatrics Baylor College of Medicine Immunization Project Texas Children's Hospital Houston (J.A.B. L.C.S.) and the Department of Pediatrics Division of Critical Care Medicine University of Texas Southwestern Children's Medical Center Dallas Dallas (M.M.) the Division of Infectious Diseases Children's Hospital Los Angeles and Departments of Pediatrics and Molecular Microbiology and Immunology University of Southern California Los Angeles (P.S.P.) the Division of Pediatric Hospital Medicine UC San Diego-Rady Children's Hospital San Diego (M.A.C.) the Division of Critical Care Medicine UCSF Benioff Children's Hospital Oakland (N.Z.C.) and the Department of Pediatrics Divisions of Critical Care Medicine and Allergy Immunology and Bone Marrow Transplant University of California San Francisco San Francisco (M.S.Z.) - all in California Section of Pediatric Critical Care Department of Pediatrics Arkansas Children's Hospital Little Rock (K.I.) the Department of Pediatrics University of North Carolina at Chapel Hill Children's Hospital Chapel Hill (T.C.W. S.P.S.) the Department of Pediatrics Section of Critical Care Medicine University of Colorado School of Medicine and Children's Hospital Colorado Aurora (A.B.M.) the Division of Pediatric Critical Care Medicine Medical University of South Carolina Charleston (E.H.M.) the Department of

Background:The increasing incidence of pediatric hospitalizations associated with coronavirus disease 2019(Covid-19)caused by the B.1.617.2(delta)variant of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)in the United States has offered an opportunity to assess the real-world effectiveness of the BNT162b2 messenger RNA vaccine in adolescents between 12 and 18 years of age.Methods:We used a case-control,test-negative design to assess vaccine effectiveness against Covid-19 resulting in hospitalization,admission to an intensive care unit(ICU),the use of life-supporting interventions(mechanical ventilation,vasopressors,and extracorporeal membrane oxygenation),or death.Between July 1 and October 25,2021,we screened admission logs for eligible case patients with laboratory-confirmed Covid-19 at 31 hospitals in 23 states.We estimated vaccine effectiveness by comparing the odds of antecedent full vaccination(two doses of BNT162b2)in case patients as compared with two hospitalbased control groups:patients who had Covid-19-like symptoms but negative results on testing for SARS-CoV-2(test-negative)and patients who did not have Covid-19-like symptoms(syndrome-negative).

关键词： vaccine doses acute

Adaptable physics-based super-resolution for electron backscatter diffraction maps

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npj Computational Materials 2022年第1期8卷 2444-2452页

作者： Devendra k.Jangid Neal R.Brodnik Michael G.Goebel Amil khan SaiSidharth Majeti McLean P.Echlin samantha H.Daly Tresa M.Pollock B.S.Manjunath Electrical and Computer Engineering University California Santa BarbaraSanta Barbara93106-5050CAUSA Mechanical Engineering University California Santa BarbaraSanta Barbara93106-5050CAUSA Computer Science University California Santa BarbaraSanta Barbara93106-5050CAUSA Materials Department University California Santa BarbaraSanta Barbara93106-5050CAUSA

In computer vision,single-image super-resolution(SISR)has been extensively explored using convolutional neural networks(CNNs)on optical images,but images outside this domain,such as those from scientific experiments,are not well investigated.Experimental data is often gathered using non-optical methods,which alters the metrics for image quality.One such example is electron backscatter diffraction(EBSD),a materials characterization technique that maps crystal arrangement in solid materials,which provides insight into processing,structure,and property relationships.We present a broadly adaptable approach for applying state-of-art SISR networks to generate super-resolved EBSD orientation maps.This approach includes quaternion-based orientation recognition,loss functions that consider rotational effects and crystallographic symmetry,and an inference pipeline to convert network output into established visualization formats for EBSD maps.The ability to generate physically accurate,high-resolution EBSD maps with super-resolution enables high-throughput characterization and broadens the capture capabilities for three-dimensional experimental EBSD datasets.

关键词： maps resolution networks