14,912 research outputs found
A biophysical model for the formation of late Pleistocene valley-fills in the Flinders Ranges of South Australia
No full textThere are scattered remnants of Mesozoic and Cainozoic deposits flanking the arid Flinders Ranges of South Australia but within the massif proper the most widespread Cainozoic deposits are the dominantly silty clay Late Pleistocene valley-fills, the most recent of which accumulated from -35 000 until -15 000 years ago (35-15 ka). Such valley-fills are not accumulating today. The valley-fills have been variously interpreted as fluviatile, lacustrine or wetland deposits. Among the questions raised by these deposits are the respective former roles of winter and summer rainfall, the influence of lower glacial temperatures and evaporation, the contributions from loess, the effect of past variations in atmospheric carbon dioxide on plant cover, the abrupt nature of post-depositional incision, evidence for episodic flooding during the Last Glacial Maximum between -24 ka and -18 ka, the entrapment and reworking of loess slope mantles, and the influence of higher regional ground-water levels. This paper puts forward a simple, speculative and integrated biophysical model that takes into account each of these factors and is able to account for the formation of fine-grained Late Pleistocene valley-fills in this presently arid region.Williams, M A J and Adamson, D
New light on the age of the White Nile
No full textLandsat 5 Thematic Mapper and 7 Enhanced Thematic Mapper imagery reveal lake shorelines in the White Nile valley as far south as lat 10°N. The highest shoreline is at 386 m elevation and was eroded when the White Nile formed a lake as wide as 70 km and >500 km long. Finely laminated green clays laid down on the floor of this lake are overlain by alluvial sands and clays, dated by optically stimulated luminescence as 15 ka to older than 250 ka. The alluvium was deposited during interglacial episodes of stronger summer monsoons and very high White Nile floods. The White Nile paleolake is much older than marine oxygen isotope stage 7 and may have formed ca. 400 ka, during the exceptionally long stage 11 interglacial.Martin A. J. Williams, Donald Adamson, John R. Prescott and Frances M. William
Una interpretación de a-ka-na-jo ( a3-ka-na-jo)
No full textThe author studies the word a-ka-na-jo in the PY Cn 328 tablet and taking into account some factors she proposes αγναιος as the reading of this word.The author studies the word a-ka-na-jo in the PY Cn 328 tablet and taking into account some factors she proposes αγναιος as the reading of this word
Environmental influences over the last 16 ka on compound-specific δ13C variations of leaf wax n-alkanes in the Hani peat deposit from northeast China
No full textCompound-specific carbon isotope ratios (δ13C) of leaf wax n-alkanes (C21-C33 odd carbon numbered n-alkanes) were measured in the Hani peat sequence from northeast China. These data were compared with lipid biomarker compositions to assess changes in local vegetation and paleoclimate for the last 16 ka The δ13C values of n-alkanes range between -36.6 and -30.7‰, showing that the compounds originate from C3 plants. Much larger variations (∼5.4‰) in the n-alkane δ13C values than those of atmospheric CO2 during the last 16 ka (< 0.5‰) indicate that the isotopic values were affected by environmental factors in addition to the postglacial δ13C variations in the atmospheric reservoir. The stratigraphic records of δ13C reveal decoupled fluctuations among the individual n-alkanes, particularly between 15.5 to 11.4 ka. Synchronous excursions in the δ13C offsets among individual n-alkanes (Δδ13C) and lipid biomarker paleoplant proxies (Paq, and C23/C31 and C27/C31) from 14.9 to 13.2 ka and 12.7 to 11.6 ka suggest that vegetational changes are the most likely causes for the decoupled δ13C variations. Parallel fluctuations of the δ13C values of terrestrial higher plant-derived C29 and C31 n-alkanes and the n-alkane average chain-length (ACL) from 11 to 6 ka indicate that the δ13C variations responded to net evaporation changes. Negative shifts in the n-alkane δ13C values coinciding with the ACL decreases at 10.5-9.3 ka and 8.1 ka indicate the short-term onset and fluctuations of the summer monsoon strength in eastern China during the early Holocene
NRF2 and chemoprevention: signaling, epigenetics and role in intestinal carcinogensis
No full textPrevention is better than cure. The carcinogenesis could take as long as 20 to 30 years to develop from initiated cells to malignant tumor, therefore providing us various opportunities to prevent the appearance of tumors with the use of chemopreventive compounds in the early stage. Chemoprevention becomes an increasing important concept and has led to the intense research about the mechanisms of actions of various chemopreventive compounds. They can be generally classified into blocking agents and suppressing agents. The chemopreventive compounds usually prevent or slow progression of cancer by maintaining a low oxidative stress and inflammatory environment in cells. This is brought about by the activation of Nrf2, the key protein being investigated in our lab. In this dissertation, I will be discussing the use of compounds as suppressing agents and blocking agents, how compounds activates Nrf2 signaling, how novel Nrf2 interaction partner IQGAP1 mediates Nrf2-Keap1 signaling axis, how expression level of Nrf2 could be regulated epigenetically, apart from the well-known post-translational control by Keap1-Ubiquitinase-Protesome axis and finally how loss of Nrf2 could enhance intestinal tumorigenesis in Apc(min/+) mice.Ph.D.Includes bibliographical referencesIncludes vitaby Ka Lung Cheun
Nearby fibroblasts' response to multiple acupuncture needle revolutions on fibroblast populated collagen gels
No full textAcupuncture is an ancient Chinese healing practice, and an alternative therapy for alleviating pain and chronic disorders. For over twenty years, research is trying to understand the mechanisms that lead to its therapeutic effect. Our laboratory investigates the cellular and molecular events in the connective tissue that occur by acupuncture needling. An in vitro assay was developed to evaluate some of the potential contributors to acupuncture’s effects using a cellular collagen gel as a loose connective tissue mimic. It was hypothesized besides immediate changes to cells under mechanical loading from an acupuncture needle, there were chemical factors released to nearby cells in acupuncture. This thesis investigates whether mechanically stimulating collagen gels with fibroblasts at different revolutions would release chemical factors to nearby fibroblasts where flow cytometry was used to observe cell proliferation as an indicator. Results reveal mechanically stimulating cellular collagen gels at different revolutions does not cause any changes in cell proliferation to nearby cells. However, dead stained mechanically stimulated cellular collagen gels showed cell death occurs around the acupuncture needle. It is possible there were no effects in cell proliferation because when a cellular collagen gel was needle manipulated, some chemical factors were released into the nearby cells. Then as needle manipulation increased, more chemical factors were released, but restricted by the larger amount of cell death around the needle from the increasing rotation.M.S.Includes bibliographical referencesby Ka Po Ch
Duan wei xia mu xie lei de xin xing he nei DNA fen zi xi tong biao ji zhi jian ding
No full textLeung Ka Chun.Thesis M.Phil. Chinese University of Hong Kong 2013.Includes bibliographical references (leaves 100-110).Abstracts also in Chinese.Title from PDF title page (viewed on 21, September, 2016).Leung Ka Chun
San zhong chao jian dai teng hu dui gao wen de sheng li fan ying ji zhuan lu ti yan jiu
No full textWong, Ka Wing Karen.Thesis M.Phil. Chinese University of Hong Kong 2014.Includes bibliographical references (leaves 143-157).Abstracts also in Chinese.Title from PDF title page (viewed on 30, November, 2016).Wong, Ka Wing Karen
The application of S-band polarimetric radar measurements to Ka-band attenuation prediction
No full textIn September 1993, the National Aeronautics and Space Administration's Advanced Communications Technology Satellite (ACTS) was deployed into a geostationary orbit near 100° W longitude. The ACTS satellite employs two Ka-band beacons, one at 20.185 GHz and another at 27.505 GHz. Impairments due to rain attenuation and tropospheric scintillations will significantly affect new technologies for this spectrum. Heavy rain at Ka-band can easily produce 30 dB of attenuation along the propagation path. Propagation experiments being conducted in seven different climatic zones involve multiyear attenuation measurements along the satellite-earth slant path. Measurements in the B2 climatic zone are made with an ACTS propagation terminal located in northeast Colorado. In order to gain more understanding about the physical processes that are responsible for Ka-band attenuation, the Colorado State University CHILL S-band polarimetric radar is used to take radar measurements along the slant path. The Colorado Front Range experiences a variety of weather conditions throughout the year ranging from upslope rain conditions to winter storms. Four such events measured along the slant path are illustrated in this paper. They include two convective cases and two "bright-band" cases. The S-band polarimetric radar data is used to initialize radar-based attenuation-prediction models, which are applied to the four precipitation events described. The comparisons of predicted attenuation to measured attenuation are quite good. It was also found during the course of the experiment that water droplets standing on the antenna surface can cause appreciable attenuation at Ka-band frequencies. That finding needs to be recognized in future model development and statistical analysis
Higher education in post-Mao china
No full textSince the death of Chairman Mao in 1976, China has embarked upon the Four Modernizations reform programme that has transformed the social, economic and political landscape of the world's most populous nation. Higher education has been ascribed a key supporting role and has itself undergone major reforms. This book looks beyond the articulated goals and accomplishments of the modernization of higher education in China. It delves into the grass roots reality and identifies the true achievements, the unintended outcomes and the major obstacles that still have to be overcome. Incorporating twenty chapters from the new generation of scholars from inside and outside China, Higher Education in Post-Mao China presents in- depth analyses of the impact of educational reforms on tertiary educators, the curriculum, the economic structure, women, and students' values and aspirations. In conveying the Chinese experience of higher education reform over the past two decades, this book makes a major contribution to contemporary sinology and comparative educationpublished_or_final_versionAcknowledgementsAbout the ContributorsAbbreviationsGlossary p435Select Bibliography p443Index p485Pt. 1.The Scope of ReformPt. 2.Enhancing ScholarshipPt. 3.Modernization and the CurriculumPt. 4.Marketization of Higher EducationPt. 5.Women in Chinese Higher EducationPt. 6.Values and AspirationsPt. 7.ConclusionsApp Executive Summary of China: Higher Education Reform. A World Bank Country Study p4171 Editors' Introduction / Michael Agelasto p12 Reforms in the Administration and Financing of Higher Education / Cheng Kai-ming p113 The Strategic Role of Faculty Development and Management / Cao Xiaonan p294 Chinese Scholars and the World Community / Wenhui Zhong p595 Returns to Education - The US/PRC Visiting Scholars Programme - 1978-88 / Michele Shoresman p796 Modernizing Science Through Educating the Elite / Cong Cao p997 Educational Utilitarianism: Where Goes Higher Education? / Liu Yingkai p1218 Modernizing English Language Teacher Education / Bob Adamson p1419 Agricultural Universities: Engines of Rural Development? / Greg Kulander p16510 Higher Adult Education: Redefining Its Roles / Xiao Jin p18911 Stratification Trends in Technical-Professional Higher Education / Vilma Seeberg p21112 Changing Conceptions of Equity and Student Financial Support Policies / Zhang Minxuan p23713 Graduate Employment: From Manpower Planning to the Market Economy / Michael Agelasto p25914 Privatization or Quasi-Marketization? / Mok Ka-ho p28115 Mixed Blessings: Modernizing the Education of Women / Carol C. Fan p29916 Chinese Educational Reforms and Feminist Praxis: On Ideals, Process and Paradigm / Maria Jaschok p32117 Gender Differences in Taiwan's Academe - Implications for the PRC / Chuing Prudence Chou p34518 Is Lei Feng Finally Dead? The Search for Values in a Time of Reform and Transition / Gay Garland Reed p35919 The Limits of Political Loosening: CCP Restraints on Student Behaviour in the Spring of 1989 / Teresa Wright p37520 Editors' Conclusion - The State of Chinese Higher Education Today / Michael Agelasto p39
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