3,031 research outputs found
Unethical aspects of homeopathic dentistry
In the last year there has been a great deal of public debate about homeopathy, the system of alternative medicine whose main principles are that like cures like and that potency increases relative to dilution. The House of Commons Select Committee on Science and Technology concluded in November 2009 that there is no evidence base for homeopathy, and agreed with some academic commentators that homeopathy should not be funded by the NHS. While homeopathic doctors and hospitals are quite commonplace, some might be surprised to learn that there are also many homeopathic dentists practising in the UK. This paper examines the statements made by several organisations on behalf of homeopathic dentistry and suggests that they are not entirely ethical and may be in breach of various professional guidelines
A classification scheme for annotating speech acts in a business email corpus
This paper reports on the process of manual annotation of speech acts in a corpus
of business emails, in the context of the PROBE project (PRagmatics of
Business English). The project aims to bring together corpus, computational,
and theoretical linguistics by drawing on the insights made available by the
annotated corpus. The corpus data sheds light on the linguistic and discourse
structures of speech act use in business email communication. This enhanced
linguistic description can be compared to theoretical linguistic representations
of speech act categories to assess how well traditional distinctions relate to
real-world, naturally occurring data. From a computational perspective, the
annotated data is required for the development of an automated speech act tagging
tool. Central to this research is the creation of a high quality, manually
annotated speech act corpus, using an easily interpretable classification
scheme. We discuss the scheme chosen for the project and the training guidelines
given to the annotators, and describe the main challenges identified by the
annotators
NIDIS Carolinas Drought Early Warning Pilot Program
2012 S.C. Water Resources Conference - Exploring Opportunities for Collaborative Water Research, Policy and Managemen
Clay Mineral Cycles Identified by Diffuse Spectral Reflectance in Quaternary Sediments From the Northwind Ridge: Implications for Glacial-Interglacial Sedimentation Patterns in the Arctic Ocean
A Quaternary record of fine-grained sediment composition is used to investigate Arctic Ocean climate variability on glacial-interglacial time scales. Diffuse spectral reflectance data from sediment core P1-92AR-P25 from the Northwind Ridge, north of Alaska, demonstrates cyclic variations in mineralogy. Varimax-rotated R-mode factor analysis of down-core data revealed three major mineralogical assemblages, which were then compared with the content of manganese, a proxy for basin ventilation, and thus glacial-interglacial cycles. Results indicate that factor 1, a smectite + chlorite clay assemblage, was delivered to the core site during interglacials, either by fluvial discharge or sea-ice drift from Siberian rivers or inflow from the Bering Sea. Factor 2, an illite + goethite assemblage, is related to glacial periods, and was probably transported from the Laurentide Ice Sheet by icebergs or meltwater. Factor 3, glauconite, might have been sourced from the North Slope region of Alaska during deglacial intervals, or from dolomites associated with Laurentide iceberg-discharge pulses. The observed variations in sediment source and transport mechanisms arise from glacial-interglacial changes in sea level, the size of the terrestrial ice sheets surrounding the Arctic Ocean, the extent of sea-ice cover and altered atmospheric circulation. The reconstructed glacial-interglacial circulation patterns from the Late Quaternary show some similarity with modern circulation changes presumably related to the monthly- to decadally-fluctuating Arctic Oscillation. However, because the Arctic Oscillation operates on much shorter time scales, further research is necessary to better understand the driving mechanism for the changes observed over glacial-interglacial cycles, and the potential role of ocean-atmospheric interaction
Arctic ice export events and their potential impact on global climate during the late Pleistocene
Ice sheets in the North American Arctic and, to a lesser extent, those in northern Eurasia calved large
quantities of icebergs that drifted through Fram Strait into the Greenland Sea several times during the late
Pleistocene. These icebergs deposited Fe oxide grains (45–250 mm) and coarse lithic clasts >250 mm matched to
specific circum-Arctic sources. Four massive Arctic iceberg export events are identified from the Laurentide and
the Innuitian ice sheets, between 14 and 34 ka (calendar years) in a sediment core from Fram Strait. These
relatively short duration (<1–4 kyr) events contain 3–5 times the background levels of Fe oxide grains. They
began suddenly, as indicated by a steep rise in the number of grains matched to an ice sheet source, suggesting
rapid purges of ice through Fram Strait, due perhaps to collapse of ice sheets. The larger events from the
northwestern Laurentide ice sheet are preceded by events from the Innuitian ice sheet. Despite the chronological
uncertainties, the Arctic export events appear to occur prior to Heinrich events
A pantothenate suxotroph of BCG rxpressing Gag confers enhanced HIV-specific immunogenicity compared to wildtype and perfingolysin expressing strains
In tuberculosis vaccine studies, perfingolysin expressing strains (pfo) of recombinant Mycobacterium bovis (rBCG) have been shown to enhance immunogenicity as compared to wildtype strains whilst pantothenate auxotrophic strains (ΔpanCD) have been shown to be safer and more immunogenic. Our group has recently shown that rBCGΔpanCD expressing HIV-1 Gag is more immunogenic than the wildtype Pasteur strain of BCG in the murine model. In this study, a wild type strain, a ΔpanCDstrain, a pfo strain and a ΔpanCD strain expressing perfringolysin (ΔpanCDpfo) of Danish BCG were used as vectors to express HIV-1 subtype C Gag. Gag specific immune responses induced by a prime with each rBCG-Gag vaccine and boost with modified vaccinia Ankara (MVA) were compared
Magnetic resonance imaging of placentome development in the pregnant Ewe
INTRODUCTION: Novel imaging measurements of placental development are difficult to validate due to the invasive nature of gold-standard procedures. Animal studies have been important in validation of magnetic resonance imaging (MRI) measurements in invasive preclinical studies, as they allow for controlled experiments and analysis of multiple time-points during pregnancy. This study characterises the longitudinal diffusion and perfusion properties of sheep placentomes using MRI, measurements that are required for future validation studies. METHODS: Pregnant ewes were anaesthetised for a MRI session on a 3T scanner. Placental MRI was used to classify placentomes morphologically into three types based on their shape and size at two gestational ages. To validate classification accuracy, placentome type derived from MRI data were compared with placentome categorisation results after delivery. Diffusion-Weighted MRI and T2-relaxometry were used to measure a broad range of biophysical properties of the placentomes. RESULTS: MRI morphological classification results showed consistent gestational age changes in placentome shape, as supported by post-delivery gold standard data. The mean apparent diffusion coefficient was significantly higher at 110 days gestation than at late gestation (~140 days; term, 150 days). Mean T2 was higher at mid gestation (152.2 ± 58.1 ms) compared to late gestation (127.8 ms ± 52.0). Significantly higher perfusion fraction was measured in late gestation placentomes that also had a significantly higher fractional anisotropy when compared to the earlier gestational age. DISCUSSION: We report baseline measurements of techniques common in placental MRI for the sheep placenta. These measurements are essential to support future validation measurements of placental MRI techniques
Multiplicity counting using organic scintillators to distinguish neutron sources: An advanced teaching laboratory
In this advanced instructional laboratory, students explore complex detection
systems and nondestructive assay techniques used in the field of nuclear
physics. After setting up and calibrating a neutron detection system, students
carry out timing and energy deposition analyses of radiation signals. Through
the timing of prompt fission neutron signals, multiplicity counting is used to
carry out a special nuclear material (SNM) nondestructive assay. Our
experimental setup is comprised of eight trans-stilbene organic scintillation
detectors in a well-counter configuration, and measurements are taken on a
spontaneous fission source as well as two ({\alpha},n) sources. By comparing
each source's measured multiplicity distribution, the resulting measurements of
the ({\alpha},n) sources can be distinguished from that of the spontaneous
fission source. Such comparisons prevent the spoofing, i.e., intentional
imitation, of a fission source by an ({\alpha},n) neutron source. This
instructional laboratory is designed for nuclear engineering and physics
students interested in organic scintillators, neutron sources, and
nonproliferation radiation measurement techniques.Comment: 29 pages, 17 figures, pre-proof accepted to AJP, AJP number
AJP22-AR-01524R2 (DOI: 10.1119/5.0139531
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