361 research outputs found

    Annotated checklist of Hongkong lichens

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    An annotated checklist of the lichens of Hong Kong, based on all available literature reports and specimens, including those recently collected by the authors, is presented. In total, 261 species are reported, of which 176 are new records for Hong Kong, 132 of which are new for China, 43 are new for East Asia, and 27 are new for Asia. The lichen vegetation is mainly tropical, as is shown by the distribution patterns of the identified species: 53 species are cosmopolitan, 40 northern temperate, 122 pantropical, 17 paleotropical and 29 endemic to tropical East Asia. With regard to substrata, 129 species are corticolous, 148 saxicolous, 17 foliicolous and 19 terricolous. Four species are newly described: Anisomeridium conorostratum Aptroot, A. hydei Aptroot, Caloplaca pulicarioides Aptroot and Placidiopsis poronioides Aptroot. The flora is rather poor in species; for example, no Caliciales have been found. In the past, the numbers of species of several groups such as the Graphidaceae, Heterodermia and Xanthoparmelia have been overestimated, whereas few pyrenocarps have been reported. The flora of wet granitic outcrops is surprisingly well developed in Hong Kong. Although not a single Peltula species was reported before, six species were identified, including one that was previously only known from Africa. In addition, several other cyanophilic genera are present, such as Euopsis, Psorotichia, Pyrenopsis and, most unexpectedly, Vestergrenopsis, each with one species. A comparison between old and recent records shows that many Lobarion species are now extinct. The drastic decline of species of the Lobarion vegetation indicates that air pollution and other habitat disturbances, mainly deforestation, to which these species are very sensitive, are seriously threatening the lichen biodiversity of Hong Kong

    Bryophytes and lichens of Aldabra

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    Aldabra Atoll, in the Republic of Seychelles, lies 450 km to the north of Madagascar and 650 km to the east of the Tanzanian coast of Africa (9o24’S, 46o20’E). It is one of the largest atolls in the world, with four main islands and numerous islets, totalling 97 km2. The underlying limestone is slightly raised, but is generally less than 8 m in elevation, and varies substantially in texture due to erosion. The atoll has been elevated above sea level for at least 80,000 years. Soils are generally shallow and alkaline (Trudgill 1979). The geology and ecology are outlined in Westoll and Stoddart (1971), Stoddart and Westoll (1979), and Stoddart (1984)

    A High Power Hydrogen Target for Parity Violation Experiments

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    Parity-violating electron scattering measurements on hydrogen and deuterium, such as those underway at the Bates and CEBAF laboratories, require luminosities exceeding 103810^{38}cm−2^{-2}s−1^{-1}, resulting in large beam power deposition into cryogenic liquid. Such targets must be able to absorb 500 watts or more with minimal change in target density. A 40~cm long liquid hydrogen target, designed to absorb 500~watts of beam power without boiling, has been developed for the SAMPLE experiment at Bates. In recent tests with 40~μ\muA of incident beam, no evidence was seen for density fluctuations in the target, at a sensitivity level of better than 1\%. A summary of the target design and operational experience will be presented.Comment: 13 pages, 9 postscript figure

    Assessment of food crop farmers indigenous strategies to climate change mitigation and adaptation in Imo State, Nigeria

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    Food crop farmers’ indigenous strategies to climate change mitigation and adaptation in Imo State, Nigeria was analyzed. The specific objectives were to; ascertain food crop farmers’ awareness of climate change; determine the farmers’ perceived effects of climate change on food crop production in the study area; identify the indigenous strategies adopted in climate change mitigation and adaptation as well as identify constraints faced by farmers in mitigating and adapting to climate change in the study area. The study used 2018 survey data from rural farming households which were selected using a random sampling technique. The farmers (65.30%) were aware of climate change effects on crop production. Indigenous strategies used include use of disease resistant varieties (58.33%), livelihood diversification (37.50%) and agro forestry practices (63.89%).The study recommends the establishment of research institutes to investigate successful adaptation and mitigation measures for scaling up and down as well as expansion of agricultural extension advisory services to educate farmers on indigenous strategies to mitigate climate change effect on crop production.Keywords: Perceived, Awareness, Indigenous, Climate Change, Farmer

    Raman spectroscopic analysis of the effect of the lichenicolous fungus Xanthoriicola physciae on its lichen host

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    YesLichenicolous (lichen-dwelling) fungi have been extensively researched taxonomically over many years, and phylogenetically in recent years, but the biology of the relationship between the invading fungus and the lichen host has received limited attention, as has the effects on the chemistry of the host, being difficult to examine in situ. Raman spectroscopy is an established method for the characterization of chemicals in situ, and this technique is applied to a lichenicolous fungus here for the first time. Xanthoriicola physciae occurs in the apothecia of Xanthoria parietina, producing conidia at the hymenium surface. Raman spectroscopy of apothecial sections revealed that parietin and carotenoids were destroyed in infected apothecia. Those compounds protect healthy tissues of the lichen from extreme insolation and their removal may contribute to the deterioration of the apothecia. Scytonemin was also detected, but was most probably derived from associated cyanobacteria. This work shows that Raman spectroscopy has potential for investigating changes in the chemistry of a lichen by an invading lichenicolous fungus.This work was completed while D.L.H. was in receipt of an award from the Ministerio de Economica y Competitividad of Spain (Proyectos CGL 2014-55542-P)

    Ethnicity data collection in the UK: the healthcare professional's perspective

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    The collection of ethnicity data has been demonstrated to be important in healthcare. However, despite recent efforts by the UK government, it remains incomplete and unvalidated. In order to be able to assess inequalities and target resources appropriately, it is essential to have complete and accurate data. This paper examines the reasons for the gaps in ethnicity data based on the perceptions and experiences of the healthcare professionals who are charged with collecting these data. A questionnaire was used to assess perceptions of ethnicity data collection, including any barriers encountered as well as the perceived importance of collecting these data. Respondents were asked whether routine ethnicity data collection was limited to specific disease areas, and approximately what proportion was complete in these areas. There were also questions concerning preferred methods of collection (e.g. self-report). The questionnaire was completed by 30 respondents, who included healthcare managers, clinicians, nurses and other staff working in the healthcare setting. The findings confirmed that the collection of patients’ ethnicity data is deemed important by the healthcare professionals, but showed that there remains uncertainty and unease as to how best to collect these data or how to explain to patients how the data will be used. The majority of healthcare professionals agreed that it was important to record patients’ ethnicity, but no clear rationale was given to staff about the use of these data, and no training was provided on the best way to collect the data.</p

    Quantumgroups in the Higgs Phase

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    In the Higgs phase we may be left with a residual finite symmetry group H of the condensate. The topological interactions between the magnetic- and electric excitations in these so-called discrete H gauge theories are completely described by the Hopf algebra or quantumgroup D(H). In 2+1 dimensional space time we may add a Chern-Simons term to such a model. This deforms the underlying Hopf algebra D(H) into a quasi-Hopf algebra by means of a 3-cocycle H. Consequently, the finite number of physically inequivalent discrete H gauge theories obtained in this way are labelled by the elements of the cohomology group H^3(H,U(1)). We briefly review the above results in these notes. Special attention is given to the Coulomb screening mechanism operational in the Higgs phase. This mechanism screens the Coulomb interactions, but not the Aharonov-Bohm interactions. (Invited talk given by Mark de Wild Propitius at `The III International Conference on Mathematical Physics, String Theory and Quantum Gravity', Alushta, Ukraine, June 13-24, 1993. To be published in Theor. Math. Phys.)Comment: 19 pages in Latex, ITFA-93-3
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