626 research outputs found

    Linear angular momentum multiplexing-conceptualization and experimental evaluation with antenna arrays

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    Linear Angular Momentum Multiplexing is a new method for providing highly spectrally efficient short range communication between a transmitter and receiver, where one may move at speed transverse to the propagation. Such applications include rail, vehicle and hyperloop transport systems communicating with fixed infrastructure on the ground. This paper describes how the scientific concept of linear angular momentum multiplexing evolves from orbital angular momentum multiplexing. The essential parameters for implementing this concept are: a long array at least at one of the ends of the link; antenna element radiation characteristics; and the array element spacing relative to the propagation distance. These parameters are also backed by short range measurements carried out at 2.4GHz used to model the Rice fading channel and determine resilience to multipath fading

    Partitioning of Mg, Sr, Ba and U into a subaqueous calcite speleothem

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    The trace-element geochemistry of speleothems is becoming increasingly used for reconstructing palaeoclimate, with a particular emphasis on elements whose concentrations vary according to hydrological conditions at the cave site (e.g. Mg, Sr, Ba and U). An important step in interpreting trace-element abundances is understanding the underlying processes of their incorporation. This includes quantifying the fractionation between the solution and speleothem carbonate via partition coefficients (where the partitioning (D) of element X (DX) is the molar ratio [X/Ca] in the calcite divided by the molar ratio [X/Ca] in the parent water) and evaluating the degree of spatial variability across time-constant speleothem layers. Previous studies of how these elements are incorporated into speleothems have focused primarily on stalagmites and their source waters in natural cave settings, or have used synthetic solutions under cave-analogue laboratory conditions to produce similar dripstones. However, dripstones are not the only speleothem types capable of yielding useful palaeoclimate information. In this study, we investigate the incorporation of Mg, Sr, Ba and U into a subaqueous calcite speleothem (CD3) growing in a natural cave pool in Italy. Pool-water measurements extending back 15 years reveal a remarkably stable geochemical environment owing to the deep cave setting, enabling the calculation of precise solution [X/Ca]. We determine the trace element variability of ‘modern’ subaqueous calcite from a drill core taken through CD3 to derive DMg, DSr, DBa and DU then compare these with published cave, cave-analogue and seawater-analogue studies. The DMg for CD3 is anomalously high (0.042 ± 0.002) compared to previous estimates at similar temperatures (∌8 °C). The DSr (0.100 ± 0.007) is similar to previously reported values, but data from this study as well as those from Tremaine and Froelich (2013) and Day and Henderson (2013) suggest that [Na/Sr] might play an important role in Sr incorporation through the potential for Na to outcompete Sr for calcite non-lattice sites. DBa in CD3 (0.086 ± 0.008) is similar to values derived by Day and Henderson (2013) under cave-analogue conditions, whilst DU (0.013 ± 0.002) is almost an order of magnitude lower, possibly due to the unusually slow speleothem growth rates (<1 ÎŒm a−1), which could expose the crystal surfaces to leaching of uranyl carbonate. Finally, laser-ablation ICP-MS analysis of the upper 7 ÎŒm of CD3, regarded as ‘modern’ for the purposes of this study, reveals considerable heterogeneity, particularly for Sr, Ba and U, which is potentially indicative of compositional zoning. This reinforces the need to conduct 2D mapping and/or multiple laser passes to capture the range of time-equivalent elemental variations prior to palaeoclimate interpretation

    The question of access to the Japanese market

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    This survey focuses on the question of how market structure and different corporate organisational forms might affect access to the Japanese market for industrial goods. The question is how and whether keiretsu corporate structures in Japan constitute an important unofficial barrier in access to the Japanese market for manufactured goods

    Res Medica, Autumn 1961, Volume 3, Number 1

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    TABLE OF CONTENTSPERFUSION: Professor W.A. MackeyABDOMINAL CRISES 1: I.S.R. Sinclair, F.R.C.S.FIBRINOLYSIS AND OCCLUSIVE VASCULAR DISEASE: J.D. Cash, B.Sc., M.B., CH.B.RES MEDICATHE UNBORN CHILD: Professor C.S. RussellTHE USE OF CONTROLS IN THE ASSESSMENT OF CLINICAL EVIDENCE: C.V. Ruckley, M.B., CH.B."THE SLIMY MUD OF WORDS":H.C. Drysdale, M.B., CH.B.THE HARVEIAN ORATION, 1961: Dr. J.K. Slater, O.B.E., M.D.MELANCHOLIA: E.B. Ritson, M.B., CH.B

    Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing

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    Low Sensitivity of BinaxNOW RSV in Infants

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    BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of hospitalization in infants. Early detection of RSV can optimize clinical management and minimize use of antibiotics. BinaxNOW RSV (BN) is a rapid antigen detection test that is widely used. We aimed to validate the sensitivity of BN in hospitalized and nonhospitalized infants against the gold standard of molecular diagnosis. METHODS: We evaluated the performance of BN in infants with acute respiratory tract infections with different degrees of disease severity. Diagnostic accuracy of BN test results were compared with molecular diagnosis as reference standard. RESULTS: One hundred sixty-two respiratory samples from 148 children from October 2017 to February 2019 were studied. Sixty-six (40.7%) samples tested positive for RSV (30 hospitalizations, 31 medically attended episodes not requiring hospitalization, and 5 nonmedically attended episodes). Five of these samples tested positive with BN, leading to an overall sensitivity of BN of 7.6% (95% confidence interval [CI], 3.3%-16.5%) and a specificity of 100% (95% CI, 96.2%-100%). Sensitivity was low in all subgroups. CONCLUSIONS: We found a low sensitivity of BN for point-of-care detection of RSV infection. BinaxNOW RSV should be used and interpreted with caution

    Enhanced climate instability in the North Atlantic and southern Europe during the Last Interglacial

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    Considerable ambiguity remains over the extent and nature of millennial/centennial-scale climate instability during the Last Interglacial (LIG). Here we analyse marine and terrestrial proxies from a deep-sea sediment sequence on the Portuguese Margin and combine results with an intensively dated Italian speleothem record and climate-model experiments. The strongest expression of climate variability occurred during the transitions into and out of the LIG. Our records also document a series of multi-centennial intra-interglacial arid events in southern Europe, coherent with cold water-mass expansions in the North Atlantic. The spatial and temporal fingerprints of these changes indicate a reorganization of ocean surface circulation, consistent with low-intensity disruptions of the Atlantic meridional overturning circulation (AMOC). The amplitude of this LIG variability is greater than that observed in Holocene records. Episodic Greenland ice melt and runoff as a result of excess warmth may have contributed to AMOC weakening and increased climate instability throughout the LIG

    Insights in paediatric virology during the COVID-19 era (Review).

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    The present article provides an overview of the key messages of the topics discussed at the '7th Workshop on Paediatric Virology', which was organised virtually on December 20, 2021 by the Institute of Paediatric Virology, located on the Island of Euboea in Greece. The workshop's plenary lectures were on: i) viral pandemics and epidemics in the ancient Mediterranean; ii) the impact of obesity on the outcome of viral infections in children and adolescents; and iii) COVID-19 and artificial intelligence. Despite the scarcity of evidence from fossils and remnants, viruses have been recognised as significant causes of several epidemics in the ancient Mediterranean. Paediatric obesity, a modifiable critical health risk factor, has been shown to impact on the development, progression and severity of viral infections. Thus, the prevention of paediatric obesity should be included in formulating public health policies and decision-making strategies against emerging global viral threats. During the current COVID-19 pandemic, artificial intelligence has been used to facilitate the identification, monitoring and prevention of SARS-CoV-2. In the future, it will play a fundamental role in the surveillance of epidemic-prone infectious diseases, in the repurposing of older therapies and in the design of novel therapeutic agents against viral infections. The collaboration between different medical specialties and other diverse scientific fields, including archaeology, history, epidemiology, nutritional technologies, mathematics, computer technology, engineering, medical law and ethics is essential for the successful management of paediatric viral infections. The current COVID-19 pandemic has underscored this need, which should be further encouraged in modern medical education
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