10,177 research outputs found
Strategies to reduce mortality from bacterial sepsis in adults in developing countries
No full textCitation: Cheng, A. C. et al. (2008). 'Strategies to reduce mortality from bacterial sepsis in adults in developing countries', PLoS Medicine, 5(8), e175. [Available at http://medicine.plosjournals.org]. © 2008 Cheng et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Hundreds of variants clustered in genomic loci and biological pathways affect human height
No full textMost common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits(1), but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait(2,3). The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P<0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways
Discursive constructions of medical students identities in informal course-based online discussions
No full textThis is an Accepted Manuscript of an article published by Taylor & Francis in Education as Change on 25 September 2009, available online: http://www.tandfonline.com/10.1080/16823200809487191.Studies into student identity have tended to focus on formal academic writing for assessment purposes. However, this is beginning to change with a shifting academic and semiotic landscape. More and more tertiary institutions are making use of the writing opportunities afforded by the online environment. Online forums are popular as they promote interaction and discussion among students. This change in the academic landscape has allowed for new approaches to studying the discursive constructions of student identity. Using critical discourse analysis, this paper explores how students construct their identities in informal course-based online discussions in Higher Education. It focuses on the various discourses medical students draw on and the language of online communication in identity construction. By providing a site for students to interact with each other, these online discussions provide for a more active curriculum where students are involved in the meaning-making process
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
The last deglaciation in Italy: timing and pattern from a precisely dated stalagmite
No full textThe last deglaciation (Termination I, T-I) was the most recent global-scale climate transition. It involved a drastic temperature increase guiding massive melting of ice sheets, with a concurrent reorganization of inter- and intrahemispherical atmospheric and ocean circulation patterns.
T-I lasted ~3.0 ka (ka = kiloyears before present) in Greenland (NGRIP, 2007), although it was not a linear process. A rapid temperature increase at 14.6±0.3 ka (Bølling-Allerød, BA) was followed by a return towards glacial-like conditions (12.2±0.3 ka, Younger Dryas, YD), before the last warming that led to the Holocene (11.7±0.1 ka). Other secondary climate oscillations characterized T-I too (Cheng et al., 2020). Some of these intra-deglaciation global warmings were particularly rapid, at times occurring at centennial or even decadal timescale. This provides an interesting comparison with the current climate change.
Yet, it is not clear how T-I-related dynamics occurring at the polar regions and/or in the oceans impacted terrestrial environment at mid latitudes, in terms of rainfall and temperature variation and related environmental and ecological changes. This is especially true for the Mediterranean area, considering that its climate is connected – and controlled – by processes occurring in the Atlantic and Arctic. In Italy, T-I records of adequate chronological resolution are virtually absent.
We here present a novel speleothem record from Sant’Angelo Cave (SA1, Ostuni, Apulia) spanning from 47.7±0.1 to 8.9±0.9 ka. In the period from ~20 to ~10 ka, multiple U-Th datings (n=22) resulted in a final age model with an average uncertainty of <0.3 ka and a resolution of ~25 years. Climate proxies (δ18O, n=1045) were anchored to this chronology. The reliability of SA1-δ18O in recording palaeoclimate information was ascertained by a statistically grounded inter-cave replication test with a recently published speleothem record from a nearby site (Columbu et al., 2020). The interpretation of SA1 allows to: 1) accurately and precisely constrain, for the first time in Italy, the timing of the T-I climate pattern; 2) evaluate the impact of BA, YD and Holocene inception in southern Italy, as well as other associated events, especially in terms of rainfall variability; and 3) understand the spatio-temporal relation between the Atlantic/Greenland domain, the Mediterranean realm and monsoonal areas throughout the deglaciation. We discuss this new record within the framework of previous regional studies based on glacial (NGRIP, 2007), marine (Martrat et al., 2007) and continental proxies (Allen et al., 1999; Cheng et al., 2016), with the aim of providing a better comprehension of the timing and structure of T-I in Italy and, by extension, of the central and western Mediterranean area.
Allen J.R.M., Brandt U., Brauer A., Hubbertens H.W., Huntley B., Keller J., Kraml M., Meckeen A., Mingram J., Negendank J.F.W., Nowaczyk N.R., Oberhansli H., Watts W.A., Wulf S. & Zolitschka B. (1999) - Rapid environmental changes in southern Europe during the last glacial period. Science, 400, 740-743.
Cheng H., Edwards R.L., Sinha A., Spötl C., Yi L., Chen S., Kelly M., Kathayat G., Wang X. & Li X. (2016) - The Asian monsoon over the past 640,000 years and ice age terminations. Nature, 534, 640.
Cheng H., Zhang H., Spötl C., Baker J., et al. (2020) - Timing and structure of the Younger Dryas event and its underlying climate dynamics. Proceedings of the National Academy of Sciences, 117, 23408-23417.
Columbu A., Chiarini V., Spötl C., Benazzi S., Hellstrom J., Cheng H. & De Waele J. (2020) - Speleothem record attests to stable environmental conditions during Neanderthal-Modern Human turnover in Southern Italy. Nature Ecology & Evolution, 4, 1188-1195.
Martrat B., Grimalt J.O., Shackleton N.J., de Abreu L., Hutterli M.A. & Stocker T.F. (2007) - Four climate cycles of recurring deep and surface water destabilizations on the Iberian margin. Science, 317, 502-507.
NGRIP, North Greenland Ice Core Project Members. (2004) - High-resolution record of Northern Hemisphere climate extending into the last interglacial period. Nature, 431, 147-151
Litsea szechuanica C. K. Allen 1941
No full textLitsea szechuanica C.K.Allen (1941: 18). Type:— CHINA. Sichuan [Szechuan]: Dujiangyang [Kuan Hsien], Qingcheng Shan [Chien- Cheng Shan], elev. ca. 1000 m, 4 April 1938, C. S. Fan & Class 139 (holotype A00041741). Paratypes in CQNM: CHINA. Sichuan: Emei Shan [Mt. Omei], Fuhu temple, 15 April 1932, T. T . Yü 282 (CQNM0015776, CQNM0015777); 19 April 1932, T. T . Yü 418 (CQNM0015778, CQNM0004227, IBK00007707, IBSC0060684, PE00028982). ≡ Litsea moupinensis var. szechuanica (C.K.Allen) Yen C.Yang & P.H.Huang in Yang et al. (1978: 47). Note: —When describing Litsea szechuanica, Allen (1941) cited 14 gatherings collected from Shaanxi, Sichuan and Yunnan as paratypes. When reducing it to a variety of L. moupinensis, Yang & al. (1978) excluded the gathering G. Fenzel 507 from Shaanxi on which they described the new species Litsea tsinlingensis Yen C.Yang & P.H.Huang in Yang et al. (1978: 46), and noted that H. T. Tsai 55967 from Yunnan was misidentified for Lindera communis Hemsl. in Forbes & Hemsley (1891: 387). Yang et al. (1978) also stated that the gathering T. T. Yü 705 from Emei Shan is Litsea veitchiana Gamble in Sargent (1914: 76), and F. T. Wang 23151 is L. moupinensis Lecomte (1913: 84).Published as part of Chen, Feng & He, Hai, 2022, The historical relics in Chongqing Natural History Museum: An annotated checklist of original materials for 37 names of Chinese seed plants, pp. 38-52 in Phytotaxa 530 (1) on page 42, DOI: 10.11646/phytotaxa.530.1.3, http://zenodo.org/record/582393
Synthesis, Electrochemistry, and Electrogenerated Chemiluminescence of Azide-BTA, a D-A-pi-A-D Species with Benzothiadiazole and N,N-Diphenylaniline, and Its Nanoparticles
No full textSeabed foraging by Antarctic krill: Implications for stock assessment, bentho-pelagic coupling, and the vertical transfer of iron
No full textA compilation of more than 30 studies shows that adult Antarctic krill (Euphausia superba) may frequent benthic habitats year-round, in shelf as well as oceanic waters and throughout their circumpolar range. Net and acoustic data from the Scotia Sea show that in summer 2-20% of the population reside at depths between 200 and 2000 m, and that large aggregations can form above the seabed. Local differences in the vertical distribution of krill indicate that reduced feeding success in surface waters, either due to predator encounter or food shortage, might initiate such deep migrations and results in benthic feeding. Fatty acid and microscopic analyses of stomach content confirm two different foraging habitats for Antarctic krill: the upper ocean, where fresh phytoplankton is the main food source, and deeper water or the seabed, where detritus and copepods are consumed. Krill caught in upper waters retain signals of benthic feeding, suggesting frequent and dynamic exchange between surface and seabed. Krill contained up to 260 nmol iron per stomach when returning from seabed feeding. About 5% of this iron is labile, i.e., potentially available to phytoplankton. Due to their large biomass, frequent benthic feeding, and acidic digestion of particulate iron, krill might facilitate an input of new iron to Southern Ocean surface waters. Deep migrations and foraging at the seabed are significant parts of krill ecology, and the vertical fluxes involved in this behavior are important for the coupling of benthic and pelagic food webs and their elemental repositories
sj-docx-1-vrd-10.1177_24741264221126061 – Supplemental material for Intravitreal Nesvacumab (Anti-Angiopoietin-2) Plus Aflibercept in Neovascular AMD: Phase 2 ONYX Randomized Trial
No full textSupplemental material, sj-docx-1-vrd-10.1177_24741264221126061 for Intravitreal Nesvacumab (Anti-Angiopoietin-2) Plus Aflibercept in Neovascular AMD: Phase 2 ONYX Randomized Trial by Jeffrey S. Heier, Allen C. Ho, David S. Boyer, Karl Csaky, Robert Vitti, Lorah Perlee, Karen W. Chu, Friedrich Asmus, Sergio Leal, Oliver Zeitz, Yenchieh Cheng, Thomas Schmelter and David M. Brown in Journal of VitreoRetinal Diseases</p
Healthcare-associated infections in Australia : time for national surveillance
No full textAbstract Objective. Healthcare-associated infection (HAI) surveillance programs are critical for infection prevention. Australia does not have a comprehensive national HAI surveillance program. The purpose of this paper is to provide an overview of established international and Australian statewide HAI surveillance programs and recommend a pathway for the development of a national HAI surveillance program in Australia. Methods. This study examined existing HAI surveillance programs through a literature review, a review of HAI surveillance program documentation, such as websites, surveillance manuals and data reports and direct contact with program representatives. Results. Evidence from international programs demonstrates national HAI surveillance reduces the incidence of HAIs. However, the current status of HAI surveillance activity in Australian states is disparate, variation between programs is not well understood, and the quality of data currently used to compose national HAI rates is uncertain. Conclusions. There is a need to develop a well-structured, evidence-based national HAI program in Australia to meet the increasing demand for validated reliable national HAI data. Such a program could be leveraged off the work of existing Australian and international programs
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