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Cultivating potential:Harnessing plant stem cells for agricultural crop improvement

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Molecular Plant 2024年第1期17卷 50-74页

作者： Penelope Lindsay Kyle w.Swentowsky david Jackson Cold Spring Harbor Laboratory Cold Spring HarborNY 11724USA National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural UniversityWuhanHubei430070China

Meristems are stem cell-containing structures that produce all plant organs and are therefore important targets for crop *** regulators control the balance and rate of cell divisions within the *** these regulators impacts meristem architecture and,as a consequence,plant *** this review,we discuss genes involved in regulating the shoot apical meristem,inflorescence meristem,axillary meristem,root apical meristem,and vascular cambium in *** highlight several examples show.ng how crop breeders have manipulated developmental regulators to modify meristem growth and alter crop traits such as inflorescence size and branching *** transformation techniques are another innovation related to plant meristem research because they make crop genome engineering *** discuss recent advances on plant transformation made possible by studying genes controlling meristem ***,we conclude with discussions about how meristem research can contribute to crop improvement in the coming decades.

关键词： meristem crop improvement plant transformation plant breeding crop yield gene editing

The impact of raw material properties and process conditions on the color of a powdered formulated detergent product

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Particuology 2019年第4期17卷 35-41页

作者： Mohamed S. Manga david willis Nurafiqah M. Ali david w. York School of Chemical and Process Engineering Faculty of Engineering University of Leeds Woodhouse Lane Leeds LS2 9JT United Kingdom

The appearance of deterge nt powder plays an importa nt role in con sumer perception of powder effectiveness for cleaning applications. In this study, we investigated the influence of numerous formulation and processing conditions on product discoloration. Product color was scrutinized using the L*a*b* color space, and in particular, L* and b*. Particle size, the method for introducing the optical brightener, and the raw material grade were very important in con trolling the optical properties of detergent granules. As the particle size decreased, the light reflected to the observer appeared brighter and bluer. This was observed as increased whiteness from L*= 84.03 with a particle size of >841 μm to L*= 90.59 with a particle size of ng the level of impurities found in the raw materials by changing the material source also improved color definition. A key finding is that the optical brightener should be applied by spraying and prepared by dispersion rather than dissolution. This improves the distribution within the granules and increases the whiteness when compared with pouring the brightener into the agglomeration vessel. Additional spray applications highlighted that brightener on the granule surface influenced whiteness more than embedded brightener. In addition, we report on the effects of the drying temperature and mixer impeller speed on powder color.

关键词： Detergent powder Powder processing Powder discoloration Optical brightener Characterization

Factors influencing the establishment of dominance hierarchies of the grey triggerfish Balistes capriscus

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Current Zoology 2010年第1期56卷 18-35页

作者： david w.CLEVELAND Kari L.LAVALLI College of General Studies Division of Natural Sciences & Mathematics Boston University

Unlike other balistids, grey triggerfish Balistes capriscus occur in social groups in subtropical reef assemblages and have been noted to cooperate in capturing large crustacean prey. The objective of this study were to determine the structure of dominance hierarchies of these social groups and the factors that influence hierarchies of wild-caught grey triggerfish in a natu- ralistic setting. From observations of four groups of triggerfish （n = 19 fish） in both dyad and group （4 - 5 fish） settings, we provide a description of triggerfish behaviors and coloration patterns and an explanation of the social context in which suites of behaviors are used by dominant, middle-ranking, and subordinate fish. Sixteen behaviors and nine coloration patterns were noted for grey triggerfish. Grey triggerfish groups form linear hierarchies in both dyads and groups as measured by Landau＇s lndex of Linearity （h = 1.0 for Groups 1, 3, and 4 and h = 0.95 for Group 2 in dyads; h = 1.0 for all groups in group settings）. Dyadic hierarchies, however, were not necessarily good predictors of the hierarchies found in larger group settings, as they only predicted two of the four group hierarchies. Sex played no role in influencing status or behavior. Size had the greatest influence on domi- nance status, with larger fish being more dominant than smaller fish. An individual＇s dominance ranking influenced both body coloration and posture. These results suggest that color patterns and body postures may also be used by observers as an indicator of an individual＇s social status in groups [Current Zoology 56 （1）： 18-35, 2010].

关键词： Grey triggerfish Balistes capriscus Balistids Dominance hierarchies Status Rank Behavior

Transfer RNA-derived small RNAs in plants

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Science China(Life Sciences) 2018年第2期61卷 155-161页

作者： Lei Zhu david w.Ow Zhicheng Dong Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China University of Chinese Academy of Sciences Beijing 100049 China

Rather than random degradation products, the 18 to 40 nucleotides(nt) transfer RNA-derived small RNAs(tsRNAs) are RNA species generated specifically from pre-RNAs or mature tRNAs in archaea, bacteria and eukaryotes. Recent studies from animal systems have shown that tsRNAs are important non-coding RNAs that regulate gene expression at the transcriptional and/or post-transcriptional levels. They are involved in various biological processes, such as cell proliferation, tumor genesis, stress response and intergenerational epigenetic inheritance. In this review, we will summarize the discovery, biogenesis, and function of tsRNAs in higher plants. In addition, analysis on tsRNAs from lower plants is shown.

关键词： tRNA derived-small RNAs tsRNAs biogenesis plant

Response of endemic afroalpine rodents to the removal of livestock grazing pressure

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Current Zoology 2011年第6期57卷 741-750页

作者： Flavie VIAL david w. MACDONALD Daniel T. HAYDON Boyd Orr Centre for Population and Ecosystem Health Institute of Biodiversity Animal Health and Comparative Medicine College of Medical Veterinary and Life Sciences University of Glasgow Glasgow G12 8QQ UK. wildlife Conservation Research Unit Zoology Department University of Oxford The Recanati-Kaplan Centre Tubney House Tubney OX13 5QL UK.

The Bale Mountains of Ethiopia represent the world＇s largest continuous extent of afroalpine habitat. with a peak combined density of over 8000 individuals/km2, the endemic giant mole rat Tachyoryctes macrocephalus, Blick＇s grass rat Arvi- canthis blicki and the brush-furred mouse Lophuromys melanonyx are the dominant wild herbivores within this ecosystem and may be affected by the presence of high densities of domestic livestock. The purpose of this study was to establish whether these endemic rodent populations could respond to the removal of grazing pressure inside three 0.25 hectare livestock exclosures （paired with grazed control plots） and to determine whether such response was mediated through concomitant changes in the vegetation structure. we hypothesised that livestock grazing negatively affects endemic rodent populations through competition or increased predation risk and we predicted an increase in rodent biomass follow.ng the removal of grazing pressure. we found no evidence of rodent populations responding to the removal of livestock after fourteen months. The short-term nature of the ex- perimental design, environmental fluctuations and the ecosystem＇s inherent stochasticity may explain the apparent lack of a sig- nificant response. However, while this study is inconclusive, it emphasises the need for more long-term experimental investiga- tions to assess the effects of domestic grazers on vegetation and on dependent communities. The effects of rapidly increasing livestock numbers in the Bale Mountains will require continued close monitoring of vegetation and endemic animal communities as the afroalpine is altered by external biotic and abiotic forces .

关键词： Afroalpine Bale Mountains Exclosures Livestock grazing Murid rodents

Positron imaging systems for studying particulate, granular and multiphase flows

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Particuology 2012年第2期10卷 146-153页

作者： Thomas w.Leadbeater david J.Parker Joseph Gargiuli Positron Imaging Centre University of BirminghamEdgbastonBirmingham B152TTUKa

The University of Birmingham has pioneered and adapted the use of the medical imaging technique known as positron emission tomography （PET） to the study of particulate, granular and multiphase flows in industrial and physical processes, This paper provides a review of the PET and complimentary positron emission particle tracking （PEPT） techniques and details their application to the study of particulate sys- tems, The current state of the art, recent developments and example results from many of the applications to which these techniques have been applied are highlighted.

关键词： Positron emission particle tracking (PEPT)Particle dynamicsMulti-phase flow measurement

Creep-fatigue lives prediction and sensitivity study of 316H at 550 ℃

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Acta Metallurgica Sinica(English Letters) 2011年第2期24卷 132-140页

作者： Zhichao FAN david J Smith Xuedong CHEN Mike w Spindler Hefei General Machinery Research Institute Hefei 23-0031 China University of Bristol Bristol BS8 1TR UK British Energy Gloucester GL4 3RS UK

In Volume 2/3 of R5 ＂An assessment procedure for the high temperature response of structures＂, the strain based ductility exhaustion method is suggested to calculate the creep damage of stress concentration region, which involves description of creep dwell initial stress, stress drop and creep ductility. Considering lots of uncertainty existed in these assessment, some sensitivity analysis is required in R5 procedure to ensure the conservatism of assessment results. In this paper, laboratory creep-fatigue test data of 316H at 550 ℃ with different loading conditions are selected as a special case to investigate whether the basic R5 approach is conservative, and the different material data combinations of cyclic stress-strain, creep deformation and creep ductility are used to identify those significant parameters affecting the assessment results. The analytical results indicate that the creep deformation model and creep ductility data are more significant to the results comparing with cyclic stress-strain data. If the upper bound of creep deformation law and lower bound of creep ductility data are used to predict their creep-fatigue lives, the degree of conservatism can be as large as a factor of -300, but if the modified creep deformation model and cast specific ductility data are used, very well prediction results can be gained within a factor of ±2.0 although there is slight non-conservatism.

关键词： Creep Fatigue Damage Life prediction Sensitivity study

Origins of perturbations in dayside equatorial ground magnetograms

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Earth and Planetary Physics 2024年第1期8卷 215-221页

作者： Syau-Yun w.Hsieh david G.Sibeck The Johns Hopkins University Applied Physics Laboratory LaurelMarylandUSA NASA Goddard Space Flight Center GreenbeltMarylandUSA

To determine the cause(s)of perturbations seen in dayside equatorial ground magnetograms,we conducted a systematic survey of simultaneous ground-based and geosynchronous satellite-based observations during the 90-day period from December 1,2020 to February 28,*** examined Huancayo ground magnetometer observations from 14:00:00 to 20:00:00 UT each day,during which Huancayo passed through local *** those data we chose perturbation events selected on the basis of large(>20 nT)event amplitude and classified the selected events as responding primarily to solar wind pressure,or to variations in the north/south component of the interplanetary magnetic field(IMF Bz),or perhaps in part to *** results show that an equivalent number of events were identified for each model during this 90-day *** in the lagged solar wind dynamic pressure routinely correspond to nearly simultaneous sudden impulses recorded at both geosynchronous orbit and on the *** in IMF Bz produce erosion signatures at geosynchronous orbit and can correspond to ground events if lag times for reconnection to enhance convection in the magnetosphere are taken into account.

关键词： dayside magnetosphere dayside equatorial ionosphere geosynchronous magnetic field

Therapy of gallstone disease:what it was,what it is,what it will be

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world Journal of Gastrointestinal Pharmacology and Therapeutics 2012年第2期3卷 7-20页

作者： Piero Portincasa Agostino Di Ciaula Leonilde Bonfrate david qh w.ng Department of Biomedical Sciences and Human Oncology Clinica Medica "A.Murri"University of Bari Medical SchoolPiazza Giulio Cesare 11Policlinico70124 BariItaly Division of Internal Medicine Hospital of Bisceglievia Bovio 27970052 Bisceglie (Bari)Italy Division of Gastroenterology and Hepatology Department of Internal MedicineEdward Doisy Research CenterSaint Louis University School of MedicineSt.LouisMO 63104United States

Cholesterol gallstone disease is a common clinical condition influenced by genetic factors,increasing age,female gender,and metabolic *** laparoscopic cholecystectomy is currently considered the gold standard in treating patients with symptomatic gallstones,new perspectives regarding medical therapy of cholelithiasis are currently under discussion,also taking into account the pathogenesis of gallstones,the natural history of the disease and the analysis of the overall costs of therapy.A careful selection of patients may lead to successful nonsurgical therapy in symptomatic subjects with a functioning gallbladder harboring small radiolucent *** classical oral litholysis by ursodeoxycholic acid has been recently paralleled by new experimental observations,suggesting that cholesterol-lowering agents which inhibit cholesterol synthesis (statins) or intestinal cholesterol absorption (ezetimibe),or drugs acting on specific nuclear receptors involved in cholesterol and bile acid homeostasis,might be proposed as additional approaches for treating cholesterol *** this review we discuss old,recent and future perspectives on medical treatment of cholesterol cholelithiasis.

关键词： Gallstones Dissolution therapy Cholecystectomy Bile acids Ezetimibe Statins Gallbladder Bile Nuclear receptors