This textbook is a readable introduction to lexicology and corpus linguistics. Starting with a survey of lexicology - the study of words - written by eminent linguist M. A. K. Halliday, the book ...looks at the basic issues in defining and understanding the word as a unit of language. It examines the history of lexicology, the evolution of dictionaries, and recent developments in lexicology. Colin Yallop takes this survey of lexicology further, to examine the relationship between words and meaning, etymology, prescription, language as social phenomenon and translation. In the second half of the textbook Wolfgang Teubert (one of the biggest names in Corpus Linguistics) and Anna Cermakova take lexicology into the field of corpus linguistics, introducing the key concepts in corpus linguistics and providing a brief history. This section expands the study of language and shows how corpus linguistics can advance our study of words and meaning, the benefits of studying the corpora, and how to meaning can best be conceptualised. Lexicology and Corpus Linguistics introduces the complicated field of corpus linguistics through lexicology.;In so doing it explains the roots of corpus linguistics in easy to understand terms, and shows how lexicology can be advanced into other modes of linguistics. The book contains a glossary and suggestions for further reading, and will be useful to students trying to get a grasp on both subjects.
Objective/Background Carotid endarterectomy (CEA) prevents future stroke, but this benefit depends on detection and control of high peri-operative risk factors. In symptomatic patients, diastolic ...hypertension has been causally related to procedural stroke following CEA. The aim was to identify risk factors causing peri-procedural stroke in asymptomatic patients and to relate these to timing of surgery and mechanism of stroke. Methods In the first Asymptomatic Carotid Surgery Trial (ACST-1), 3,120 patients with severe asymptomatic carotid stenosis were randomly assigned to CEA plus medical therapy or to medical therapy alone. In 1,425 patients having their allocated surgery, baseline patient characteristics were analysed to identify factors associated with peri-procedural (< 30 days) stroke or death. Multivariate analysis was performed on risk factors with a p value < .3 from univariate analysis. Event timing and mechanism of stroke were analysed using chi-square tests. Results A total of 36 strokes (27 ischaemic, four haemorrhagic, five unknown type) and six other deaths occurred during the peri-procedural period, resulting in a stroke/death rate of 2.9% (42/1,425). Diastolic blood pressure at randomisation was the only significant risk factor in univariate analysis (odds ratio OR 1.34 per 10 mmHg, 95% confidence interval CI 1.04–1.72; p = .02) and this remained so in multivariate analysis when corrected for sex, age, lipid lowering therapy, and prior infarcts or symptoms (OR 1.34, 95% CI 1.05–1.72; p = .02). In patients with diastolic hypertension (> 90 mmHg) most strokes occurred during the procedure (67% vs. 20%; p = .02). Conclusion In ACST-1, diastolic blood pressure was the only independent risk factor associated with peri-procedural stroke or death. While the underlying mechanisms of the association between lower diastolic blood pressure and peri-procedural risk remain unclear, good pre-operative control of blood pressure may improve procedural outcome of carotid surgery in asymptomatic patients.
The geochemistry of Cd in seawater has attracted significant attention owing to the nutrient‐like properties of this element. Recent culturing studies have demonstrated that Cd is a biologically ...important trace metal that plays a role in the sequestration of inorganic carbon. This conclusion is supported by recent isotope data for Cd dissolved in seawater and incorporated in cultured phytoplankton. These results show that plankton features isotopically light Cd while Cd‐depleted surface waters typically exhibit complimentary heavy Cd isotope compositions. Seawater samples from below 900 m depth display a uniform and intermediate isotope composition of ε114/110Cd = +3.3 ± 0.5. This study investigates whether ferromanganese (Fe‐Mn) crusts are robust archives of deep water Cd isotope compositions. To this end, Cd isotope data were obtained for the recent growth surfaces of 15 Fe‐Mn crusts from the Atlantic, Pacific, Indian, and Southern oceans and two USGS Fe‐Mn reference nodules using double spike multiple collector inductively coupled plasma mass spectrometry. The Fe‐Mn crusts yield a mean ε114/110Cd of +3.2 ± 0.4 (2 SE, n = 14). Data for all but one of the samples are identical, within the analytical uncertainty of ±1.1ε114/110Cd (2 SD), to the mean deep water Cd isotope value. This indicates that Fe‐Mn crusts record seawater Cd isotope compositions without significant isotope fractionation. A single sample from the Southern Ocean exhibits a light Cd isotope composition of ε114/110Cd = 0.2 ± 1.1. The origin of this signature is unclear, but it may reflect variations in deep water Cd isotope compositions related to differences in surface water Cd utilization or long‐term changes in seawater ε114/110Cd. The results suggest that time series analyses of Fe‐Mn crusts may be utilized to study changes in marine Cd utilization.
The
16O,
17O and
18O abundances of howardites, eucrites, and diogenites have been used to assign them to a single ‘HED’ parent body, thought to be asteroid 4 Vesta. We report the first evidence of ...oxygen isotopic heterogeneity among HED meteorites indicating incompletely mixed sources. New high-precision oxygen isotope measurements of 34 HED meteorites reveal that most have the same Δ
17O′, consistent with a very rapid early history of large-scale mixing on Vesta. However, howardites are on average very slightly enriched in
16O, whereas Ibitira, Caldera, Pasamonte, and ALHA78132 are
16O-depleted compared to other investigated eucrites. The Δ
17O′ of Ibitira is completely different from all other HEDs measured. Some of the results for eucrites and diogenites can be explained by partial melting and rapid mixing of the interior of Vesta. Others require a separate parent body or indicate that parts of the outer layer of Vesta retained some primary isotopic heterogeneity. The oxygen isotopic composition of howardites provides an upper limit for the amount of admixed carbonaceous chondritic material into the HED parent body regolith.
Bistable epigenetic switches are fundamental for cell fate determination in unicellular and multicellular organisms. Regulatory proteins associated with bistable switches are often present in low ...numbers and subject to molecular noise. It is becoming clear that noise in gene expression can influence cell fate. Although the origins and consequences of noise have been studied, the stochastic and transient nature of RNA errors during transcription has not been considered in the origin or modeling of noise nor has the capacity for such transient errors in information transfer to generate heritable phenotypic change been discussed. We used a classic bistable memory module to monitor and capture transient RNA errors: the lac operon of Escherichia coli comprises an autocatalytic positive feedback loop producing a heritable all-or-none epigenetic switch that is sensitive to molecular noise. Using single-cell analysis, we show that the frequency of epigenetic switching from one expression state to the other is increased when the fidelity of RNA transcription is decreased due to error-prone RNA polymerases or to the absence of auxiliary RNA fidelity factors GreA and GreB (functional analogues of eukaryotic TFIIS). Therefore, transcription infidelity contributes to molecular noise and can effect heritable phenotypic change in genetically identical cells in the same environment. Whereas DNA errors allow genetic space to be explored, RNA errors may allow epigenetic or expression space to be sampled. Thus, RNA infidelity should also be considered in the heritable origin of altered or aberrant cell behaviour.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A practical, one-pot, two-step catalytic method is described for the synthesis of 2,5-diformylfuran (DFF) from fructose via dehydration to 5-(hydroxymethyl)furfural (HMF), followed by in situ ...catalytic air-oxidation.
Understanding the biogeochemical cycle of magnesium (Mg) is not only crucial for terrestrial ecology, as this element is a key nutrient for plants, but also for quantifying chemical weathering fluxes ...of Mg and associated atmospheric CO2 consumption, requiring distinction of biotic from abiotic contributions to Mg fluxes exported to the hydrosphere. Here, Mg isotope compositions are reported for parent basalt, bulk soils, clay fractions, exchangeable Mg, seasonal soil solutions, and vegetation for five types of volcanic soils in Iceland in order to improve the understanding of sources and processes controlling Mg supply to vegetation and export to the hydrosphere. Bulk soils (δ26Mg=−0.40±0.11‰) are isotopically similar to the parent basalt (δ26Mg=−0.31‰), whereas clay fractions (δ26Mg=−0.62±0.12‰), exchangeable Mg (δ26Mg=−0.75±0.14‰), and soil solutions (δ26Mg=−0.89±0.16‰) are all isotopically lighter than the basalt. These compositions can be explained by a combination of mixing and isotope fractionation processes on the soil exchange complex. Successive adsorption–desorption of heavy Mg isotopes leads to the preferential loss of heavy Mg from the soil profile, leaving soils with light Mg isotope compositions relative to the parent basalt. Additionally, external contributions from sea spray and organic matter decomposition result in a mixture of Mg sources on the soil exchange complex. Vegetation preferentially takes up heavy Mg from the soil exchange complex (Δ26Mgplant-exch=+0.50±0.09‰), and changes in δ26Mg in vegetation reflect changes in bioavailable Mg sources in soils. This study highlights the major role of Mg retention on the soil exchange complex amongst the factors controlling Mg isotope variations in soils and soil solutions, and demonstrates that Mg isotopes provide a valuable tool for monitoring biotic and abiotic contributions of Mg that is bioavailable for plants and is exported to the hydrosphere.
Spontaneous DNA breaks instigate genomic changes that fuel cancer and evolution, yet direct quantification of double-strand breaks (DSBs) has been limited. Predominant sources of spontaneous DSBs ...remain elusive. We report synthetic technology for quantifying DSBs using fluorescent-protein fusions of double-strand DNA end-binding protein, Gam of bacteriophage Mu. In Escherichia coli GamGFP forms foci at chromosomal DSBs and pinpoints their subgenomic locations. Spontaneous DSBs occur mostly one per cell, and correspond with generations, supporting replicative models for spontaneous breakage, and providing the first true breakage rates. In mammalian cells GamGFP-labels laser-induced DSBs antagonized by end-binding protein Ku; co-localizes incompletely with DSB marker 53BP1 suggesting superior DSB-specificity; blocks resection; and demonstrates DNA breakage via APOBEC3A cytosine deaminase. We demonstrate directly that some spontaneous DSBs occur outside of S phase. The data illuminate spontaneous DNA breakage in E. coli and human cells and illustrate the versatility of fluorescent-Gam for interrogation of DSBs in living cells. DOI:http://dx.doi.org/10.7554/eLife.01222.001.
Immunohistochemical (IHC) staining of formalin-fixed and paraffin-embedded tissues (FFPE) is widely used in diagnostic surgical pathology. All anatomical and surgical pathologists use IHC to confirm ...cancer cell type and possible origin of metastatic cancer of unknown primary site. What kinds of improvements in IHC are needed to boost and strengthen the use of IHC in future diagnostic pathology practice? The aim of this perspective is to suggest that continuing reliance on immunohistochemistry in cancer diagnosis, search and validation of biomarkers for predictive and prognostic studies and utility in cancer treatment selection means that minimum IHC data sets including "normalization methods" for IHC scoring, use of relative protein expression levels, use of protein functional pathways and modifications and protein cell type specificity may be needed when markers are proposed for use in diagnostic pathology. Furthermore evidence based methods (EBM), minimum criteria for diagnostic accuracy (STARD), will help in selecting antibodies for use in diagnostic pathology. In the near future, quantitative methods of proteomics, quantitative real-time polymerase chain reaction (qRT-PCR) and the use of high-throughput genomics for diagnosis and predictive decisions may become preferred tools in medicine.
Lexicology Halliday, M. A. K; Yallop, Colin; Halliday, M A K
2007, 2007-03-08
eBook
This readable introductory textbook presents a concise survey of lexicology. The first section of the book is a survey of the study of words, providing students with an overview of basic issues in ...defining and understanding the word as a unit of language. This section also examines the history of lexicology, the evolution of dictionaries and recent developments in the field. The second section extends this study of lexicology into the relationship between words and meaning, etymology, prescription, language as social phenomenon and translation. Lexicology: A Short Introduction will be of interest to undergraduate students of linguistics.
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