检索结果-南通市图书馆

Genomic mosaicism of the Brain:Origin,Impact,and utility

在线全文

学校读者我要写书评

暂无评论

Neuroscience Bulletin 2024年第6期40卷 759-776页

作者： Jared H.Graham Johannes C.m.schlachetzki Xiaoxu Yang martin W.Breuss Department of Pediatrics Section of Clinical Genetics and MetabolismUniversity of Colorado School of MedicineAurora80045-2581COUSA Department of Cellular and molecular medicine University of California San DiegoLa Jolla92093-0021San DiegoCAUSA Department of Neurosciences University of California San DiegoLa Jolla92093-0021San DiegoCAUSA Rady Children’s Institute for Genomic medicine San Diego92123CAUSA

Genomic mosaicism describes the phenomenon where some but not all cells within a tissue harbor unique genetic ***,research focused on the impact of genomic mosaicism on clinical phenotype—motivated by its involvement in cancers and overgrowth *** recently,we increasingly shifted towards the plethora of neutral mosaic variants that can act as recorders of cellular lineage and environmental ***,we summarize the current state of the field of genomic mosaicism research with a special emphasis on our current understanding of this phenomenon in brain development and *** the field of genomic mosaicism has a rich history,technological advances in the last decade have changed our approaches and greatly improved our *** will provide current definitions and an overview of contemporary detection approaches for genomic ***,we will discuss the impact and utility of genomic mosaicism.

关键词： Genomics Brain development Brain homeostasis Genomic mosaicism

Atmospheric methane over the Past 2000 Years from a sub-tropical Ice Core, Central Himalayas

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of mountain science 2010年第1期7卷 1-14页

作者： LI Jiule Xu Baiqing YAO Tandong WANG Ninglian Ken macClune Laboratory of Tibetan Environment Changes and Land surface Processes Chinese Academy of Sciences Beijing 100085 China state Key Laboratory of Cryospheric science Chinese Academy of Sciences Lanzhou 730000 China stable Isotope Laboratory Institute ofArctic andAlpine Research University of Colorado Boulder Colorado CO 80303 USA

A high-resolution 2ooo-year methane record has been constructed from an ice core recovered at 7200 m a.s.1, on the Dasuopu Glacier in the central Himalayas. This sub-tropical methane record reveals an increasing trend in the concentration of methane during the industrial era that is similar to observations from polar regions. However, we also observed the differences in the atmospheric methane mixing ratio between this monsoon record and those from polar regions during pre-industrial times. In the time interval o N 1850 A.D., the average methane concentration in the Dasuopu ice core was 782±40 ppbv and the maxim.m.temporal variation exceeded 200 ppbv. The difference gradient of methane concentration in Dasuopu ice core with Greenland and Antarctica cores are 66±40 ppbv and 107±40 ppbv, respectively. This suggests that the tropical latitudes might have acted as a major global methane source in preindustrial times. In addition, the temporal fluctuation of the pre-industrial methane records suggests that monsoon evolution incorporated with high methane emission from south Asia might be responsible for the relatively high methane concentration observed in the Dasuopu ice core around A.D. 800 and A.D. 1600. These results provide a rough understanding of the contribution of tropical methane source to the global methane budget and also the relationship betweenatmospheric methane and climate change.

关键词： climate change ice core air bubble atmospheric methane Dasuopu Glacier centralHimalayas

Contrast Normalization strategies in Brain Tumor Imaging:From Preprocessing to Classification

在线全文

学校读者我要写书评

暂无评论

Computer modeling in Engineering & sciences 2024年第8期140卷 1539-1562页

作者： samar m.Alqhtani Toufique A.soomro Faisal Bin ubaid Ahmed Ali muhammad Irfan Abdullah A.Asiri Department of Information systems College of Computer Science and Information SystemsNajran UniversityNajran61441Saudi Arabia Department of Electronic Engineering The University of LarkanoLarkanaSindh75660Pakistan Computer science Department Sukkur IBA UniversitySukkurSindh65200Pakistan Eletrical Engineering Department Sukkur IBA UniversitySukkurSindh65200Pakistan Electrical Engineering Department College of EngineeringNajran UniversityNajran61441Saudi Arabia radiological sciences Department College of Applied Medical SciencesNajran UniversityNajran61441Saudi Arabia

Cancer-related to the nervous system and brain tumors is a leading cause of mortality in various *** resonance imaging(mRI)and computed tomography(CT)are utilized to capture brain *** plays a crucial role in the diagnosis of brain tumors and the examination of other brain ***,manual assessment of mRI images by radiologists or experts is performed to identify brain tumors and abnormalities in the early stages for timely ***,early diagnosis of brain tumors is intricate,necessitating the use of computerized *** research introduces an innovative approach for the automated segmentation of brain tumors and a framework for classifying different regions of brain *** proposed methods consist of a pipeline with several stages:preprocessing of brain images with noise removal based on Wiener Filtering,enhancing the brain using Principal Component Analysis(PCA)to obtain well-enhanced images,and then segmenting the region of interest using the Fuzzy C-means(FCm)clustering technique in the third *** final step involves classification using the support Vector machine(sVm)*** classifier is applied to various types of brain tumors,such as meningioma and pituitary tumors,utilizing the Contrast-Enhanced magnetic Resonance Imaging(CE-mRI)*** proposed method demonstrates significantly improved contrast and validates the effectiveness of the classification framework,achieving an average sensitivity of 0.974,specificity of 0.976,accuracy of 0.979,and a Dice score(DsC)of ***,this method exhibits a shorter processing time of 0.44 s compared to existing *** performance of this method emphasizes its significance when compared to state-of-the-art methods in terms of sensitivity,specificity,accuracy,and *** enhance the method further in the future,it is feasible to standardize the approach by incorporating a set of classifiers to increase the robustness of the brain classi

关键词： Brain tumor magnetic resonance imaging principal component analysis fuzzy c-clustering support vector machine

Pitting corrosion behavior and corrosion protection performance of cold sprayed double layered noble barrier coating on magnesium-based alloy in chloride containing solutions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of magnesium and Alloys 2023年第9期11卷 3099-3119页

作者： m.Daroonparvar A.Helmer A.m.Ralls m.u.Farooq Khan A.K.Kasar R.K.Gupta m.m.sra s.shao P.L.menezes N.shamsaei National Center for Additive manufacturing Excellence Auburn UniversityAuburnAL 36849USA Department of mechanical Engineering Auburn UniversityAuburnAL 36849USA Department of materials science and Engineering College of EngineeringNorth Carolina State University911 Partners WayRaleighNC 27695USA Department of mechanical Engineering University of Nevada RenoRenoNV 89501USA Department of Nuclear Engineering and radiological sciences University of MichiganAnn ArborMI 48105 USA Department of Chemical and materials Engineering University of Nevada RenoNV 89501USA

Nitrogen processed, cold sprayed commercially pure(CP)-Al coatings on mg-based alloys mostly lack acceptable hardness, wear resistance and most importantly are highly susceptible to localized corrosion in chloride containing solutions. In this research, commercially pure α-Ti top coating having good pitting potential(~1293 mV_(sCE)), high microhardness(HV_(0.025): 263.03) and low wear rate was applied on a CP-Al coated mg-based alloy using high pressure cold spray technology. Potentiodynamic polarization(PDP) curves indicated that the probability of transition from.m.tastable pits to the stable pits for cold spayed(Cs) Al coating is considerably higher compared to that with the Cs Ti top coating(for Ti/Al/mg system). In addition, Cs Ti top coating was in the passivation region in most pH ranges even after 48 h immersion in 3.5 wt% NaCl solution. The stored energy in the Cs Ti top coating(as a passive metal) was presumed to be responsible for the easy passivation. Immersion tests indicated no obvious pits formation on the intact Cs Ti top coating surface and revealed effective corrosion protection performance of the Cs double layered noble barrier coatings on mg alloys in 3.5 wt% NaCl solution even after 264 h.

关键词： Ti coating mg alloys Localized corrosion Passivity Dislocation density Crystallite size

An Internal state Variable model for the Low Temperature Tempering of Low Alloy steels

在线全文

学校读者我要写书评

暂无评论

Journal of shanghai Jiaotong university(science) 2000年第1期5卷 178-184页

作者： mark T. Lusk, Young-Kook Lee, Herng-Jeng Jou, William H. Elliott, Gerard m Ludtka 1.materials science Program, Division of Engineering, colorado school of mines, Golden, CO. u.s. 80401 2.Questek Innovations LCC, 1801 maple Avenue, Evanston, IL, u.s. 602

An internal state variable (IsV) framework is used to predict the rate and degree of strain relaxation associated with the stage I, low temperature tempering of martensite. A single variable tracks the change in volume between the tempered an untempered structures. The rate at which this occurs is taken to be a function of martensite fraction, temperature, degree of tempering, and carbon concentration. Experimental dilatometty data is used to both fit and validate the model.

关键词： Tempering model Quenching Phase Transformations

Genome and clonal hematopoiesis stability contrasts with immune,cfDNA,mitochondrial,and telomere length changes during short duration spaceflight

在线全文

学校读者我要写书评

暂无评论

Precision Clinical medicine 2024年第1期7卷 1-13页

作者： J.sebastian Garcia-medina Karolina sienkiewicz s.Anand Narayanan Eliah G.Overbey Kirill Grigorev Krista A.Ryon marissa Burke Jacqueline Proszynski Braden Tierney Caleb m.schmidt Nuria mencia-Trinchant Remi Klotz Veronica Ortiz Jonathan Foox Christopher Chin Deena Najjar Irina matei Irenaeus Chan Carlos Cruchaga Ashley Kleinman JangKeun Kim Alexander Lucaci Conor Loy Omary mzava Iwijn De Vlaminck Anvita singaraju Lynn E.Taylor Julian C.schmidt michael A.schmidt Kelly Blease Juan moreno Andrew Boddicker Junhua Zhao Bryan Lajoie Andrew Altomare semyon Kruglyak shawn Levy min Yu Duane C.Hassane susan m.Bailey Kelly Bolton Jaime mateus Christopher E.mason Department of Physiology and Biophysics Weill Cornell MedicineCornell UniversityNew YorkNY 10021USA The HRH Prince Alwaleed Bin Talal Bin Abdulaziz Alsaud Institute for Computational Biomedicine Weill Cornell MedicineNew YorkNY 10021USA Department of Immunology Weill Cornell MedicineCornell UniversityNew YorkNY 10021USA Department of stem Cell Biology and Regenerative medicine Keck School of MedicineUniversity of Southern CaliforniaLos AngelesCA 90033USA space Exploration Technologies Corporation HawthomeCA 90250USA sovaris Aerospace BoulderCO 80302USA Advanced Pattern Analysis&Human Performance Group BoulderCO 80302USA Children's Cancer and Blood Foundation Laboratories Departments of Pediatrics and Cell and Developmental BiologyDrukier Institute for Children's HealthMeyer Cancer CenterWeill Cornell MedicineNew YorkNY 10021USA meyer Cancer Center Weill Cornell MedicineNew YorkNY 10065USA Department of Nutrition and Integrative Physiology Florida State UniversityTallahasseeFL 32306USA Department of systems Engineering Colorado State UniversityFort CollinsCO 80523USA Element Biosciences San DiegoCA 10055USA Department of Environmental and radiological health sciences Colorado State UniversityFort CollinsCO 80523USA Cell and molecular Biology Program Colorado State UniversityFort CollinsCO 80523USA BioAstra Inc New YorkNYUSA Washington university st Louis Oncology Division St.LouisMO 63100USA meinig school of Biomedical Engineering Cornell UniversityIthacaNY 14853USA The Feil Family Brain and mind Research Institute Weill Cornell MedicineNY 10021USA WorldQuant Initiative for Quantitative Prediction Weill Cornell MedicineNew YorkNY 10021USA

Background The Inspiration4(I4)mission,the first all-civilian orbital flight mission,investigated the physiological effects of short-duration spaceflight through a multi-omic *** advances,there remains much to learn about human adaptation to spaceflight's unique challenges,including microgravity,immune system perturbations,and radiation *** To provide a detailed genetics analysis of the mission,we collected dried blood spots pre-,during,and post-flight for DNA *** length was measured by quantitative PCR,while whole genome and cfDNA sequencing provided insight into genomic stability and immune adaptations.A robust bioinformatic pipeline was used for data analysis,including variant calling to assess mutational *** Telomere elongation occurred during spaceflight and shortened after return to ***-free DNA analysis revealed increased immune cell signatures *** significant clonal hematopoiesis of indeterminate potential(CHIP)or whole-genome instability was *** long-term gene expression changes across immune cells suggested cellular adaptations to the space environment persisting months *** Our findings provide valuable insights into the physiological consequences of short-duration spaceflight,with telomere dynamics and immune cell gene expression adapting to spaceflight and persisting after return to *** sequencing data will serve as a reference point for studying the early development of CHIP in astronau.s.a. understudied phenomenon as previous studies have focused on career *** study will serve as a reference point for future commercial and non-commercial spaceflight,low Earth orbit(LEO)missions,and deep-space exploration.

关键词： genomes clonal hematopoiesis stability immune mitochondria ribosomes spaceflight

The sensitivity of snowpack sublimation estimates to instrument and measurement uncertainty perturbed in a monte Carlo framework

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Earth science 2018年第4期12卷 728-738页

作者： D.m.HuLTsTRAND s.R.FAssNACHT EAsC-Watershed science Colorado State UniversityFort CollinsCO 80523-1482USA Ess-Watershed science Colorado State UniversityFort CollinsCO 80523-1476USA Cooperative Institute for Research in the Atmosphere Fort CollinsCO 80523-1375USA Geographisches Institut Abt.KartographieGIS &FemerkundungGeorg-August-Universitat Gottingen37077GottingenGermany Natural Resources Ecology Laboratory Fort CollinsCO 80523-1499USA

The bulk aerodynamic flux equation is often used to estimate snowpack sublimation since it requires meteorological measurements at only one height above the snow surface. However, to date the uncertainty of these estimates and the individual input variables and input parameters uncertainty have not been quantified. We modeled sublimation for three (average snowpack in 2005, deep snowpack in 2011, and shallow snowpack in 2012) different water years (October 1 to september 30) at West Glacier Lake watershed within the Glacier Lakes Ecosystem Experiments site in *** performed a monte Carlo analysis to evaluate the sensitivity of modeled sublimation to uncertainties of the input variables and parameters from the bulk aerodynamic flux equation. Input variable time series were uniformly adjusted by a normally distributed random variable with a standard deviation given as follows: 1) the manufacturer’s stated instrument accuracy of 0.3°C for temperature (T), 0.3 m/s for wind speed (uz), 2% for relative humidity (RH), and 1 mb for pressure (P); 2) 0.0093 m for the aerodynamic roughness length (z0) based on z0 profiles calculations from.m.ltiple heights; and 3) 0.08 m for measurement height (z). Often z is held constant; here we used a constant z compared to the ground surface, and subsequently altered z to account for the change in snow depth (ds). The most important source of uncertainty was z0, then RH. Accounting for measurement height as it changed due to snowpack accumulation/ablation was also relevant for deeper snow. snow surface sublimation uncertainties, from this study, are in the range of 1% to 29% for individual input parameter perturbations. The mean cumulative uncertainty was 41% for the three water years with 55%, 37%, and 32% occurring for the wet, average, and low water years. The top three variables (z varying with ds, z0, and RH) accounted for 74% to 84% of the cumulative sublimation uncertainty.

关键词： snow sublimation uncertainty aerodynamic methods

Lions, hyenas and mobs （oh my!）

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Current Zoology 2017年第3期63卷 313-322页

作者： Kenna D.s. LEHmANN Tracy m. mONTGOmERY sarah m. mACLACHLAN Jenna m. PARKERC livia s. sPAGNuOLO Kelsey J. VANDEWETERING Patrick s. BILLs Kay E. HOLEKAmP Department of Integrative Biology Michigan State University 288 Farm Lane Room 203 East Lansing MI 48824 USA Ecology Evolutionary Biology and Behavior Michigan State University 293 Farm Lane Room 103 East Lansing MI 48824 USA Department of Fish Wildlife and Conservation Biology Colorado State University 1474 Campus Delivery Fort Collins CO 80523 USA Conservation Ecology and Environmental Informatics School of Natural Resources and Environment University of Michigan 440 Church St. Ann Arbor MI 48109 USA Institute for Cyber Enabled Research Michigan State University Biomedical & Physical Sciences Building 567 Wilson Road Room 1440 East Lansing MI 48824 USA

understanding the factors that facilitate the emergence of cooperation among organisms is central to the study of social evolution. spotted hyenas Crocuta crocuta frequently cooperate to mob lions Panthera leo, approaching the lions as a tightknit group while vocalizing loudly in an attempt to overwhelm them and drive them away. Whereas cooperative mobbing behavior has been well documented in birds and some m.m.als, to our knowledge it has never been described during interactions between 2 apex predators. using a 27-year dataset, we characterize lion-hyena encoun- ters, assess rates of mobbing behavior observed during these interactions, and inquire whether mobbing results in successful acquisition of food. Lions and hyenas interacted most often at fresh kills, especially as prey size and the number of hyenas present increased. Possession of food at the beginning of an interaction positively affected retention of that food by each predator species. The presence of male lions increased the probability of an interspecific interaction but decreased the likelihood of hyenas obtaining or retaining possession of the food. Hyena mobbing rates were highest at fresh kills, but lower when adult male lions were present. The occurrence of mobbing was predicted by an increase in the number of hyenas present. Whether or not mobbing resulted in acquisition of food from lions was predicted by an increase in the number of mobs formed by the hyenas present, suggesting that cooperation among hyenas enhances their fitness.

关键词： competition cooperation hyena lion mobbing sociality.

A test of two mechanisms proposed to optimize grassland aboveground primary productivity in response to grazing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2012年第4期5卷 357-365页

作者： A.K.Knapp D.L.Hoover J.m.Blair G.Buis D.E.Burkepile A.Chamberlain s.L.collins R.W.s.Fynn K.P.Kirkman m.D.smith D.Blake N.Govender P.O'Neal T.schreck A.Zinn Graduate Degree Program in Ecology and Department of Biology Colorado State UniversityFort CollinsCO 80526USA Division of Biology Kansas State UniversityManhattanKS 66506USA Department of Biological sciences Florida International UniversityNorth MiamiFL 33181USA Department of Biology MSC03-2020University of New MexicoAlbuquerqueNM 87131USA Okavango Research Institute University of BotswanaPrivate Bag 285MaunBotswana school of Biological and Conservation science University of KwaZulu-NatalPrivate Bag X01Scottsville 3209PietermaritzburgSouth Africa Department of Ecology and Evolutionary Biology Yale UniversityNew HavenCT 06520USA scientific services Kruger National ParkPrivate Bag X402Skukuza1350South Africa Department of Ecology and Evolutionary Biology University of CaliforniaIrvineCA 92697USA

Aims mesic grasslands have a long evolutionary history of grazing by large herbivores and as a consequence,grassland species have numerous adaptations allowing them to respond favourably to *** empirical evidence has been equivocal,theory predicts that such adaptations combined with alterations in resources can lead to grazing-induced overcompensation in aboveground net primary production(ANPP;grazed ANPP>ungrazed ANPP)under certain *** tested two specific predictions from ***,overcompensation is more likely to occur in annually burned grasslands because limiting nutrients that would be lost with frequent fires are recycled through grazers and stimulate ***,overcompensation of biomass lost to grazers is more likely to occur in unburned sites where grazing has the greatest effect on increasing light availability through alterations in canopy *** We tested these nutrient versus light-based predictions in grazed grasslands that had been annually burned or protected from fire for>20 *** assessed responses in ANPP to grazing by large ungulates using both permanent and moveable grazing exclosures(252 exclosures from which biomass was harvested from 3192 quadrats)in a 2-year *** sites were located at the Konza Prairie Biological station(KPBs)in North America and at Kruger National Park(KNP)in south *** KPBs,sites were grazed by North American bison whereas in KNP sites were grazed either by a diverse suite of herbivores(*** wildebeest,Burchell’s zebra,African buffalo)or by a single large ungulate(African buffalo).Important Findings We found no evidence for overcompensation in either burned or unburned sites,regardless of grazer ***,there was no support for either mechanism leading to ***,complete compensation of total biomass lost to grazers was the most common response characterizing grazing–ANPP relationships with,in some cases,undercompensation of grass ANPP being of

关键词： aboveground net primary production fire forbs herbivores savanna