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Acorn size and tolerance to seed predators:the multiple roles of acorns as food for seed predators,fruit for dispersal and fuel for growth

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Integrative Zoology 2018年第3期13卷 251-266页

作者： Andrew W.BARTLOW Salvatore JAGOSTA Rachel CURTIS Xianfeng YI Michael ASTEELE Department of Biology and The WIESS Institute for Environmental Science and Sustainability Wilkes UniversityWilkes BarrePennsylvaniaUSA Present address:Department of Biology University of UtahSalt Lake CityUtahUSA Center for Environmental Studies and Department of Biology Virginia Commonwealth UniversityRichmondVirginiaUSA Present address:Department of Veterinary Integrative Biosciences Texas A&M UniversityCollege StationTexasUSA College of Life Sciences Jiangxi Normal UniversityNanchangJiangxiChina.

Fitness of parents and offspring is affected by offspring size.In oaks(Quercus spp.),acorns vary considerably in size across,and within,species.Seed size influences dispersal and establishment of oaks,but it is not known whether size imparts tolerance to seed predators.Here,we examine the relative extent to which cotyledon size serves as both a means for sustaining partial consumption and energy reserves for developing seedlings during early stages of establishment.Acorns of 6 oak species were damaged to simulate acorn predation by vertebrate and invertebrate seed predators.Seedling germination/emergence and growth rates were used to assess seedling performance.We predicted that if cotyledons are important for dispersal,acorns should show tolerance to partial seed consumption.Alternatively,if the cotyledon functions primarily as an energy reserve,damage should significantly influence seedling performance.Acorns of each species germinated and produced seedlings even after removing>50%of the cotyledon.Seed mass explained only some of the variation in performance.Within species,larger acorns performed better than smaller acorns when damaged.Undamaged acorns performed as well or better than damaged acorns.There was no pattern among individual species with increasing amounts of damage.In some species,simulated invertebrate damage resulted in the poorest performance,suggesting alternative strategies of oaks to sustain damage.Large cotyledons in acorns may be important for attracting seed dispersers and sustaining partial damage,while also providing energy to young seedlings.Success of oak establishment may follow from the resilience of acorns to sustain damage at an early stage.

关键词： acorns damage tolerance dispersal Quercus seed size

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Effects of vegetation differences in relocated Utah prairie dog release sites

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Natural Science 2013年第5期5卷 44-49页

作者： Rachel CURTIS Shandra Nicole Frey Department of Wildland Resources Utah State University Logan USA

Utah prairie dogs have been extirpated in 90% of their historical range. Because most of the population occurs on private land, this threatened species is continually in conflict with land-owners due to burrowing. The Utah Division of Wildlife Resources has been relocating Utah prairie dogs from private to public land since the 1970s, but relocations have been largely unsuccessful due to high mortality. Utah prairie dogs were relocated in 2010 and 2011 from the golf course in Cedar City, Utah to two prepared sites near Bryce Canyon National Park, Utah. Vegetation transects were established at each site to determine if there was a correlation between site vegetation composition and structure, and Utah prairie dog survival at relocation sites. The vegetation at the two sites was significantly different. One site had significantly less grass cover, more invasive plant cover, and rockier soils. The sites also had different soil structures and long-term Utah prairie dog retention rates. Newly established burrows were clustered rather than randomly distributed. Utah prairie dogs appeared to avoid placing burrows in areas with tall vegetation and rocky soils. More research is needed to determine how site selection determines longterm retention and colonization of a relocation site.

关键词： Burrows Cynomys Parvidens Relocation Reseeding Utah Prairie Dog Vegetation Composition Vegetation Structure

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The key piece of the airway remodeling puzzle revealed-LIGHT signaling in the lung

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Genes & Diseases 2023年第4期10卷 1131-1132页

作者： Ziyan rachel Chen Jim Hu Programmes in Translational Medicine Research InstituteHospital for Sick ChildrenTorontoOntario M5G 0A4Canada Department of Laboratory Medicine and Pathobiology University of TorontoTorontoOntario M5S 1A8Canada Department of Paediatrics University of TorontoTorontoOntario M5S 1A8Canada

Asthma is a chronic lung disease that primarily affects the lower respiratory tract in more than 300 million people worldwide.Asthma is often triggered by exposure to certain substances or conditions,such as allergens or cold air.The overreaction to the allergens causes inflammation and narrowing of the airway,which leads to episodic or persistent symptoms including shortness of breath,nocturnal cough,chest tightness,and wheezing.

关键词： airway lung inflammation

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Effectiveness of overuse injury prevention programs on upper extremity performance in overhead youth athletes:A systematic review

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Sports Medicine and Health Science 2023年第2期5卷 91-100页

作者： rachel Y.Lau Swarup Mukherjee Physical Education and Sport Science Academic Group National Institute of EducationNanyang Technological University Singapore1 Nanyang Walk637616Singapore

Several targeted upper extremity injury prevention programs have been developed to mitigate the risk of upper extremity overuse injuries among youth athletes in overhead sports;however,their effectiveness on performance outcome measures has not been investigated.This systematic review evaluated the effectiveness of existing upper extremity injury prevention programs that focused on modifying intrinsic risk factors,and performance outcome measures in overhead youth athletes.The secondary aim was to identify the training components of these programs.PubMed,Physiotherapy Evidence Database(PEDro),SPORTDiscus(via EBSCOhost),and Web of Science were searched from January 2000 to November 2020 for studies that implemented training programs or exercises for upper extremity injury prevention among youth athletes in overhead throwing or striking sports.An updated search was conducted from December 2020 to October 2022.A program was deemed effective for a performance outcome measure if significant improvements were observed in the intervention group as compared to the control group.Of the 1394 studies identified,five studies met the inclusion criteria.The effectiveness of the injury prevention programs on the identified performance outcome measures of strength,mobility,and sport-specific measures were 30.4%,28.6%,and 22.2%,respectively.The training components targeted were strength,mobility,and plyometrics.Strength was the most common training component and was also the most widely investigated performance outcome measure.Overall,current upper extremity injury prevention programs seem effective at improving performance outcome measures of strength,mobility,and sport-specific outcomes with training components of strength,mobility and plyometrics.Standardized protocols are required for the measurement and reporting of performance outcomes measures,and the reporting of training components.

关键词： Youth sports Overhead athlete Overuse injury Injury prevention Shoulder Elbow

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Research on Prostate MRI Segmentation with Random Walker and GAN

Research on Prostate MRI Segmentation with Random Walker and...

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作者： Nubwimana rachel 河北工业大学

学位级别：硕士

前列腺癌是男性第二常见的恶性肿瘤,仅次于肺癌,在发达国家的发病率更高。前列腺癌早期可能无症状,病程缓慢,只有在癌症进展时才会出现症状。因此,如果早发现、早诊断、早治疗,治愈率可以大大提高。前列腺癌的诊断和治疗主要采用MRI图... 详细信息

前列腺癌是男性第二常见的恶性肿瘤,仅次于肺癌,在发达国家的发病率更高。前列腺癌早期可能无症状,病程缓慢,只有在癌症进展时才会出现症状。因此,如果早发现、早诊断、早治疗,治愈率可以大大提高。前列腺癌的诊断和治疗主要采用MRI图像检测技术,其中许多问题包括腹部MRI中前列腺的准确性和自动分割,这对临床应用至关重要。目前,大多数现有的前列腺分割方法都是通过一系列的程序进行的,每一步都需要手动经验参数调整,且存在分割效率低和精度低等问题,为此,研究有利于计算机辅助诊断、适用于有限样本图像集的全自动算法是非常有意义的。此外,由于存在腺体边界模糊,分割不足或过度等问题,以及大数据处理的需要,研究前列腺MRI图像分割的深度学习方法非常必要,尤其是生成性对抗网络(GAN)由于其灵活的结构和强大的功能,已逐渐应用于各种图像处理任务。为此,本论文针对上述问题开展了以下工作。(1)基于随机游走算法的前列腺MRI图像分割研究。为解决分割效率低、轮廓不完整、分割泄漏和偏差大等问题,并适应于有限的图像集和全自动处理,提出一种改进的随机游走算法,即多图谱RW进行图像分割,其算法步骤如下:选择具有可见前列腺轮廓的切片,生成其真值(正确的标注值),用于图谱和多图谱生成。在此过程中,真值图像被采样成相同的像素大小和图像大小,然后,所有真值图像被叠加到一个单独的图像空间中。在堆叠过程之后,在该图像空间中生成概率图,并选择两个概率级别来提取内部种子(前景种子)和外部种子(背景种子)。生成的种子被作为随机行走算法的自动种子。通过实验分析,将提出的多图谱RW与图谱RW的和基本RW进行比较,并使用形状相似性进行评估,平均Dice相似系数(DSC)分别为0.72、0.62和0.52,平均Jaccard相似系数(JSC)分别为0.71、0.62和0.54。同样使用距离和体积差进行评估,Hausdorff距离(H)分别为4.87、5.93和5.89,相对体积差(RVD)分别为0.36、0.48和0.57。研究结果表明提出的多图谱RW是切实可行且行之有效的。(2)基于生成对抗网络(GAN)的前列腺MRI图像分割研究。为克服腺体边界模糊,前列腺内组织的异质性导致的分割不足或过度,以及患者或病理学之间的生理差异等问题,并适应于大数据图集处理,提出一种基于端到端深度学习生成对抗网络(GAN)的前列腺分割模式(PGAN),其任务是区分结构分割过程中使用的真值掩模和分割掩模,具有EM距离的生成对抗网络(GAN)进行像素级语义分割。然后将PGAN模式应用于四种不同的GAN结构,即带有基本鉴别器的PGAN、带有早期融合网络的PGAN、带有回归网络的PGAN和带有乘积网络的PGAN。在实验分析中,使用Dice相似系数(DSC)、Jaccard相似系数、相对体积差异(RVD)和Hausdorff距离(H)等多种指标对前列腺分割进行比较,并在一个数据集上进行评估,该数据集包含493个磁共振成像作为训练数据,98个磁共振成像作为实验测试数据。研究结果表明,所提出的带回归网络的PGAN的DSC平均值为0.97,JSC平均值为0.97,RVD平均值为0.01,H平均值为2.93。显然,它优于基本GAN和随机Walker等分割方法,是一种适合大数据处理的分割方法。

关键词：磁共振图像前列腺图像分割随机行走算法生成对抗网络

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The role of copper in enhancing the performance of heteronuclear diatomic catalysts for the electrochemical CO_(2)conversion to C_(1) chemicals

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Journal of Energy Chemistry 2023年第10期85卷 490-500,I0013页

作者： Qi Zhao rachel Crespo-Otero Devis Di Tommaso Department of Chemistry School of Physical and Chemical SciencesQueen Mary University of LondonLondon E14NSUK Department of Chemistry University College LondonLondon WC1H 0AJUK

Diatomic catalysts(DACs)with two adjacent metal atoms supported on graphene can offer diverse functionalities,overcoming the inherent limitations of single atom catalysts(SACs).In this study,density functional theory calculations were conducted to investigate the reactivity of the carbon dioxide(CO_(2))reduction reaction(CO_(2)RR)on metal sites of both DACs and SACs,as well as their synergistic effects on activity and selectivity.Calculation of the Gibbs free energies of CO_(2)RR and associated values of the limiting potentials to generate C_(1) products showed that Cu acts as a promoter rather than an active catalytic centre in the catalytic CO_(2)conversion on heteronuclear DACs(CuN_(4)-MN_(4)),improving the catalytic activity on the other metal compared to the related SAC MN_(4).Cu enhances the initial reduction of CO_(2)by promoting orbital hybridization between the key intermediate*COOH 2p-orbitals and the metals 3d-orbitals around the Fermi level.This degree of hybridization in the DACs CuN_(4)-MN_(4) decreases from Fe to Co,Ni,and Zn.Our work demonstrates how Cu regulates the CO_(2)RR performance of heteronuclear DACs,offering an effective approach to designing practical,stable,and high-performing diatomic catalysts for CO_(2)electroreduction.

关键词： Electrocatalytic CO_(2)reduction Single atom catalysts Diatomic catalysts Graphene Density functional theory calculations

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Forecasting the spread of the COVID-19 pandemic in Kenya using SEIR and ARIMA models

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Infectious Disease Modelling 2022年第2期7卷 179-188页

作者： Joyce Kiarie Samuel Mwalili rachel Mbogo Institute of Mathematical Sciences Strathmore UniversityNairobiKenya School of Mathematical and Physical Sciences Jomo Kenyatta University of Agriculture and TechnologyNairobiKenya

COVID-19,a coronavirus disease 2019,is an ongoing pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).The first case in Kenya was identified on March 13,2020,with the pandemic increasing to about 237,000 confirmed cases and 4,746 deaths by August 2021.We developed an SEIR model forecasting the COVID-19 pandemic in Kenya using an Autoregressive Integrated moving averages(ARIMA)model.The average time difference between the peaks of wave 1 to wave 4 was observed to be about 130 days.The 4th wave was observed to have had the least number of daily cases at the peak.According to the forecasts made for the next 60 days,the pandemic is expected to continue for a while.The 4th wave peaked on August 26,2021(498th day).By October 26,2021(60th day),the average number of daily infections will be 454 new cases and 40 severe cases,which would require hospitalization,and 16 critically ill cases requiring intensive care unit services.The findings of this study are key in developing informed mitigation strategies to ensure that the pandemic is contained and inform the preparedness of policymakers and health care workers.

关键词： ARIMA COVID-19 Infectious disease model Forecasting SEIR Kenya pandemic

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Regulation of enolase activation to promote neural protection and regeneration in spinal cord injury

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Neural Regeneration Research 2023年第7期18卷 1457-1462页

作者： Hannah MMcCoy rachel Polcyn Naren LBanik Azizul Haque Department of Microbiology and Immunology Medical University of South CarolinaCharlestonSCUSA Department of Neurosurgery Medical University of South CarolinaCharlestonSCUSA Ralph H.Johnson Veterans Administration Medical Center CharlestonSCUSA

Spinal cord injury(SCI)is a debilitating condition characterized by damage to the spinal cord resulting in loss of function,mobility,and sensation with no U.S.Food and Drug Administration-approved cure.Enolase,a multifunctional glycolytic enzyme upregulated after SCI,promotes pro-and anti-inflammatory events and regulates functional recovery in SCI.Enolase is normally expressed in the cytosol,but the expression is upregulated at the cell surface following cellular injury,promoting glial cell activation and signal transduction pathway activation.SCI-induced microglia activation triggers pro-inflammatory mediators at the injury site,activating other immune cells and metabolic events,i.e.,Rho-associated kinase,contributing to the neuroinflammation found in SCI.Enolase surface expression also activates cathepsin X,resulting in cleavage of the C-terminal end of neuron-specific enolase(NSE)and non-neuronal enolase(NNE).Fully functional enolase is necessary as NSE/NNE C-terminal proteins activate many neurotrophic processes,i.e.,the plasminogen activation system,phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B,and mitogen-activated protein kinase/extracellular signal-regulated kinase.Studies here suggest an enolase inhibitor,ENOblock,attenuates the activation of Rho-associated kinase,which may decrease glial cell activation and promote functional recovery following SCI.Also,ENOblock inhibits cathepsin X,which may help prevent the cleavage of the neurotrophic C-terminal protein allowing full plasminogen activation and phosphatidylinositol-4,5-bisphosphate 3-kinase/mitogen-activated protein kinase activity.The combined NSE/cathepsin X inhibition may serve as a potential therapeutic strategy for preventing neuroinflammation/degeneration and promoting neural cell regeneration and recovery following SCI.The role of cell membrane-expressed enolase and associated metabolic events should be investigated to determine if the same strategies can be applied to other neurodegenerative diseases.Hence,this review discus

关键词： cathepsin X ENOblock enolase glia mitogen-activated protein kinase/extracellular signal-regulated kinase neurodegeneration neuroinflammation phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B Rho-associated protein kinase spinal cord injury

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Von Hippel-Lindau tumor suppressor pathways&corresponding therapeutics in kidney cancer

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Journal of Genetics and Genomics 2021年第7期48卷 552-559页

作者： Maxwell Shulman rachel Shi Qing Zhang Department of Pathology University of Texas Southwestern Medical CenterDallasTXUSA

The identification and application of the Von Hippel-Lindau(VHL)gene is a seminal breakthrough in kidney cancer research.VHL and its protein p VHL are the root cause of most kidney cancers,and the cascading pathway below them is crucial for understanding hypoxia,in addition to the aforementioned tumorigenesis routes and treatments.We reviewed the history and functions of VHL/pVHL and Hypoxia-inducible factor(HIF),their well-known activities under low-oxygen environments as an E3 ubiquitin ligase and as a transcription factor,respectively,as well as their non-canonical functions revealed recently.Additionally,we discussed how their dysregulation promotes tumorigenesis:beginning with chromosome 3 p-arm(3p)loss/epigenetic methylation,followed by two-allele knockout,before the loss of complimentary tumor suppressor genes leads cells down predictable oncological paths.These different pathways can ultimately determine the grade,outcome,and severity of the deadliest genitourinary cancer.We finished by investigating current and proposed schemes to therapeutically treat clear cell renal cell carcinoma(cc RCC)by manipulating the hypoxic pathway utilizing Vascular Endothelial Growth Factor(VEGF)inhibitors,mammalian target of rapamycin complex 1(mTORC1)inhibitors,small molecule HIF inhibitors,immune checkpoint blockade therapy,and synthetic lethality.

关键词： VHL HIF ccRCC Kidney cancer Hypoxia

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On the effects of spatial resolution on effective distance measurement in digital landscapes

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Ecological Processes 2021年第1期10卷 659-677页

作者： rachel Mundeli Murekatete Takeshi Shirabe KTH Royal Institute of Technology School of Architecture and the Built EnvironmentTeknikringen 10A11428 StockholmSweden University of Rwanda College of Science and TechnologyCentre for Geographic Information Systems and Remote SensingKN 67 Street NyarugengeKigaliRwanda

Background:Connectivity is an important landscape attribute in ecological studies and conservation practices and is often expressed in terms of effective distance.If the cost of movement of an organism over a landscape is effectively represented by a raster surface,effective distances can be equated with the cost-weighted distance of least-cost paths.It is generally recognized that this measure is sensitive to the grid’s cell size,but little is known if it is always sensitive in the same way and to the same degree and if not,what makes it more(or less)sensitive.We conducted computational experiments with both synthetic and real landscape data,in which we generated and analyzed large samples of effective distances measured on cost surfaces of varying cell sizes derived from those data.The particular focus was on the statistical behavior of the ratio—referred to as‘accuracy indicator’—of the effective distance measured on a lower-resolution cost surface to that measured on a higher-resolution cost surface.Results:In the experiment with synthetic cost surfaces,the sample values of the accuracy indicator were generally clustered around 1,but slightly greater with the absence of linear sequences(or barriers)of high-cost or inadmissible cells and smaller with the presence of such sequences.The latter tendency was more dominant,and both tendencies became more pronounced as the difference between the spatial resolutions of the associated cost surfaces increased.When two real satellite images(of different resolutions with fairly large discrepancies)were used as the basis of cost estimation,the variation of the accuracy indicator was found to be substantially large in the vicinity(1500 m)of the source but decreases quickly with an increase in distance from it.Conclusions:Effective distances measured on lower-resolution cost surfaces are generally highly correlated with—and useful predictors of—effective distances measured on higher-resolution cost surfaces.This relationship tends to be weakened when linear barriers to disp

关键词： Landscape connectivity Effective distance Raster-based least-cost path model Accuracy Spatial resolution

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