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Hippocampal stem cells:so they are multipotent!

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Journal of Molecular Cell Biology 2011年第5期3卷 270-272页

作者： Verdon taylor Centre for Stem Cell Biology Department of Biomedical ScienceUniversity of SheffieldWestern BankSheffield S102TNUK Department of Molecular Embryology Max Planck Institute of Immunobiology and EpigeneticsStubeweg 51Freiburg D-79108Germany

Although neurogenesis continues throughout life in the mammalian brain,the issue of whether the stem cells that drive the process in vivo are self-renewing and multipotent remains *** a recent landmark paper by Bonaguidi et al.(2011)published in Cell,the authors provide clonal evidence that neural stem cells in the dentate gyrus of the adult hippocampus are indeed multipotent and undergo symmetric cell divisions.

关键词： al. potent stem

Heterotrophic ammonium removal characteristics of an aerobic heterotrophic nitrifying-denitrifying bacterium, Providencia rettgeri YL

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Journal of Environmental Sciences 2009年第10期21卷 1336-1341页

作者： taylor Shauna M School of Environmental Science and Engineering Shanghai Jiao Tong University

Bacterium Providencia rettgeri YL was found to exhibit an unusual ability to heterotrophically nitrify and aerobically denitrify various concentrations of ammonium （NH4^＋-N）. In order to further understand its removal ability, several experiments were conducted to identify the growth and ammonium removal response at different carbon to nitrogen （C/N） mass ratios, shaking speeds, temperatures, ammonium concentrations and to qualitatively verify the production of nitrogen gas using gas chromatography techniques. Results showed that under optimum conditions （C/N 10, 30℃, 120 r/min）, YL can significantly remove low and high concentrations of ammonium within 12 to 48 h of growth, respectively. The nitrification products hydroxylamine （NHzOH）, nitrite （NO2^-） and nitrate （NO3^-） as well as the denitrification product, nitrogen gas （N2）, were detected under completely aerobic conditions.

关键词： Providencia rettgeri YL heterotrophic ammonium removal aerobic denitrification

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The Moon

Acta Geochimica 2016年第1期35卷 1-13页

作者： ross taylor australian national university CanberraAustralia

Recent geochemical and geophysical data from the Moon enable a revision of earlier interpretations regarding lunar origin, structure and bulk composition. Earth and Moon show many similarities among their isotopic compositions, but they have evolved in totally dissimilar ways, probably related to the deficiency of water and volatile elements in the Moon as well as the vast differences in size and internal pressure. Some global geochemical differences from the Earth such as volatile depletion based on K/U ratios have been established. However, all current lunar samples come from differentiated regions, making the establishment of a bulk composition more reliant on bulk geophysical properties or isotopic similarities; it remains unclear how the latter arose or relate to whole Moon composition. The lack of fractionation effects among the refractory and super-refractory elements indicates that the proto-lunar material seems unlikely to have been vaporized while the presence of volatile elements may place lower limits on proto-lunar temperatures. The apparent lack of geochemical evidence of an impacting body enables other possible impactors, such as comets, to be considered. Although the origin of the Moon remains currently unknown, it is generally believed that the Moon originated as the result of a giant impact on the Earth.

关键词： Lunar origin Grand tack model Apollo Volatite elements

Practical Approaches to Risk Assessment

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Biomedical and Environmental Sciences 2001年第1期14卷 14-20页

作者： SIMON BROOKE-taylor AustraliaNewZealandFoodAuthority

he importance of using risk assessment in developing food regulations is growing with the globalization of our food supply. The World Trade Organization has entrenched the principles of science based risk assessment in the Agreement on Sanitary and Phytosanitary Measures. The relevant international organization for food standards, the Codex Alimentarius Commission, recognises risk analysis, and its component parts risk assessment, risk management and risk communication, as the basis for scientific decision making. Risk assessment comprises two activities: hazard evaluation; and exposure estimation. A hazard may be chemical, microbiological or nutritional in origin. The practical application of risk assessment in Australia is illustrated in this presentation by four examples involving: (1) food additives, (2) microbiological safety of imported raw milk cheeses, (3) genetically modified foods and (4) imported food inspection.

关键词： risk assessment World Trade Organization practical application risk communication food inspection risk analysis principles of food supply raw milk

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Prime gradient noise

Computational Visual Media 2021年第3期7卷 349-362页

作者： Sheldon taylor Owen Sharpe Jiju Peethambaran Graphics&Spatial Computing Lab Dept.of Math&CSSaint Mary’s UniversityHailifaxNSCanadaB3H3C3

Procedural noise functions are fundamental tools in computer graphics used for synthesizing virtual geometry and texture ***,a procedural noise function should be compact,aperiodic,parameterized,and randomly *** lattice noise functions such as Perlin noise,however,exhibit periodicity due to the axial correlation induced while hashing the lattice vertices to the *** this paper,we introduce a parameterized lattice noise called prime gradient noise(PGN)that minimizes discernible periodicity in the noise while enhancing the algorithmic *** utilizes prime gradients,a set of random unit vectors constructed from subsets of prime numbers plotted in polar coordinate *** map axial indices of lattice vertices to prime gradients,PGN employs Szudzik pairing,a bijection F:N2→*** of Szudzik pairing functions are used in higher *** the core of PGN is the ability to parameterize noise generation though prime sequence offsetting which facilitates the creation of fractal noise with varying levels of heterogeneity ranging from homogeneous to hybrid multifractals.A comparative spectral analysis of the proposed noise with other noises including lattice noises show that PGN significantly reduces axial correlation and hence,periodicity in the noise *** demonstrate the utility of the proposed noise function with several examples in procedural modeling,parameterized pattern synthesis,and solid texturing.

关键词： procedural noise procedural texture Perlin noise prime numbers

Dynamic transcriptional programs define distinct mammalian cortical lineages

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Neural Regeneration Research 2024年第2期19卷 387-389页

作者： Tanzila Mukhtar Verdon taylor Department of Biomedicine University of BaselBaselSwitzerland Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research University of CaliforniaSan FranciscoCAUSA

The cerebral cortex is composed of billions of neurons and glia that are generated sequentially during *** cells are generated in an organized fashion during *** early stages of brain development,neural stem cells(NSC... 详细信息

关键词： cortex cerebral development

Species diversity in restoration plantings: Important factors for increasing the diversity of threatened tree species in the restoration of the Araucaria forest ecosystem

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Plant Diversity 2019年第2期41卷 84-93页

作者： taylor E.Shaw School of Biological Sciences University of East Anglia Norwich Research Park

The Araucaria forest ecosystem in southern Brazil is highly threatened: less than one percent of the original forest remains, and what is left is a fragmented agro-mosaic of mostly early-to-late secondary forest patches among high-yield agriculture and timber monocultures. Forest restoration initiatives in this region aim to restore degraded areas, however the limited number of species used in restoration projects represents a missed opportunity for species-rich plantings. High diversity plantings represent a larger number of functional groups and provide a targeted conservation strategy for the high number of threatened species within this ecosystem. This study interviewed nurseries(Ns) and restoration practitioners(RPs) in Parana and Santa Catarina states to identify what species are being cultivated and planted, and what factors are driving the species selection process. An average of 20 species were reportedly used in restoration plantings, most of which are common, widespread species. Baseline data confirms that Ns and RPs have disproportionately low occurrences of threatened species in their inventories and plantings, supporting findings from previous research. Questionnaire responses reveal that opportunities for seed acquisition are an extremely important factor in order for nurseries to increase their diversity of cultivated species. Results also suggest that facilitating speciesrich plantings for restoration practitioners would only be feasible if it did not increase the time required to complete planting projects, as it would minimize their ability to keep costs low. This study proposes solutions for increasing the number of species used in restoration practicedsuch as developing a comprehensive species list, fostering knowledge-sharing between actors, creating seed sharing programs, and increasing coordination of planting projects. Long-term strategies involve complimenting traditional ex situ approaches with emerging inter-situ and quasi in situ conserv

关键词： Restoration Araucaria forest Threatened species Nurseries Restoration practitioners Decision-making

The capsid revolution

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Journal of Molecular Cell Biology 2023年第11期15卷 1-11页

作者： Ian A.taylor Ariberto Fassati Macromolecular Structure Laboratory The Francis Crick InstituteLondon NW11ATUK Division of Infection and Immunity University College LondonLondon WC1E 6JFUK Institute of Immunity and Transplantation University College LondonLondon NW32PPUK

Lenacapavir,targeting the human immunodeficiency virus type-1(HIV-1)capsid,is the first-in-class antiretroviral drug recently approved for clinical *** development of Lenacapavir is attributed to the remarkable progress in our understanding of the capsid protein made during the last few *** little more than a component of the virus shell to be shed early during infection,the capsid has been found to be a key player in the HIV-1 life cycle by interacting with multiple host factors,entering the nucleus,and directing ***,we describe the key advances that led to this‘capsid revolution’.

关键词： HIV-1 capsid CPSF6 Lenacapavir integration IP6 nucleus reverse transcription

Revisiting taxonomy,morphological evolution,and fossil calibration strategies in Chloranthaceae

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Journal of Systematics and Evolution 2011年第4期49卷 315-329页

作者： Alexandre ANTONELLI taylor S.FEILD Gothenburg Botanical Garden and Department of Plant and Environmental Sciences University of Gothenburg Department of Ecology and Evolutionary Biology University of Tennessee

Chloranthaceae is one of the earliest diverging angiosperm families and is comprised of approximately 75 species in four genera (Chloranthus,Sarcandra,Ascarina,and Hedyosmum).This family has received considerable attention because of its seemingly primitive morphology,disjunct tropical distribution in Asia and America,and extensive fossil record from the Early *** the present study,we reconstructed the phylogeny of Chloran- thaceae based on a combined dataset of three plastid DNA regions and 56 *** then estimated divergence times in the family using two relaxed molecular clock methods (BEAST and penalized likelihood).We focused on testing the influence of fossil taxa in calibrating the molecular phylogeny,and on assessing the current taxonomy of the family in light of the phylogenetic *** results indicate that most intrageneric divisions within Asca-rina and Hedyosmum are not *** results from the dating analysis suggest that the Hedyosmum-like fossil Asteropollis represents a stem lineage of Hedyosmum,as has been suggested previously from morphological *** contrast,our results indicate that the Chloranthus-like fossil Chloranthistemon,previously suggested on morphological grounds to be a stem relative of Chloranthus,may,instead,belong to the branch leading to the clade Chloranthus + *** median crown ages of Chloranthus,Sarcandra,Ascarina,and Hedyosmum estimated in the BEAST analysis were 26.3,9.5,31.0 and 45.8 million years ago (Ma),respectively,whereas the divergence between Chloranthus and Sarcandra,the splitting of Ascarina with the former two genera,and Hedyos- mum separating from the three genera were estimated to 63.8,95.7 and 111.1 *** present study sheds further light on the temporal evolution of Chloranthaceae and exemplifies how molecular dating analyses may be used to explore alternative phylogenetic placements of fossil taxa.

关键词： angiosperm evolution Asteropollis Chloranthaceae Chloranthistemon molecular dating phylogeny.