407 research outputs found
The integral monodromy of hyperelliptic and trielliptic curves
We compute the \integ/\ell and \integ_\ell monodromy of every irreducible
component of the moduli spaces of hyperelliptic and trielliptic curves. In
particular, we provide a proof that the \integ/\ell monodromy of the moduli
space of hyperelliptic curves of genus is the symplectic group
\sp_{2g}(\integ/\ell). We prove that the \integ/\ell monodromy of the
moduli space of trielliptic curves with signature is the special
unitary group \su_{(r,s)}(\integ/\ell\tensor\integ[\zeta_3])
Novel luminescent materials based on silica doped with an europium(III) complex of 2,6-dihydroxybenzoic acid: the crystal structure of [(nBu4N)2[Eu(2,6-Hdhb)(5)(H2O)(2)]
Novel luminescent materials were prepared by introducing a new Eu3+ complex of 2,6-dihydroxybenzoic acid (2,6-H2dhb) into a silica
gel made by the sol–gel method. The crystal structure of the resulting complex [nBu4N]2[Eu(2,6-Hdhb)5(H2O)2] was determined using
single-crystal X-ray diffraction. The compound was further characterised using FTIR, FT-Raman and elemental analysis. Photoluminescence
measurements were performed for the isolated Eu(III) 2,6-dihydroxybenzoate complex and also for the related silica composite material
Suitability of pesticide risk indicators for less developed countries: a comparison
Pesticide risk indicators provide simple support in the assessment of environmental and health risks
from pesticide use, and can therefore inform policies to foster a sustainable interaction of agriculture
with the environment. For their relative simplicity, indicators may be particularly useful under conditions
of limited data availability and resources, such as in Less Developed Countries (LDCs). However,
indicator complexity can vary significantly, in particular between those that rely on an exposure–toxicity
ratio (ETR) and those that do not. In addition, pesticide risk indicators are usually developed for Western
contexts, which might cause incorrect estimation in LDCs. This study investigated the appropriateness
of seven pesticide risk indicators for use in LDCs, with reference to smallholding agriculture in Colombia.
Seven farm-level indicators, among which 3 relied on an ETR (POCER, EPRIP, PIRI) and 4 on a non-ETR
approach (EIQ, PestScreen, OHRI, Dosemeci et al., 2002), were calculated and then compared by means
of the Spearman rank correlation test. Indicators were also compared with respect to key indicator characteristics,
i.e. user friendliness and ability to represent the system under study. The comparison of the
indicators in terms of the total environmental risk suggests that the indicators not relying on an ETR
approach cannot be used as a reliable proxy for more complex, i.e. ETR, indicators. ETR indicators, when
user-friendly, show a comparative advantage over non-ETR in best combining the need for a relatively
simple tool to be used in contexts of limited data availability and resources, and for a reliable estimation
of environmental risk. Non-ETR indicators remain useful and accessible tools to discriminate between
different pesticides prior to application. Concerning the human health risk, simple algorithms seem more
appropriate for assessing human health risk in LDCs. However, further research on health risk indicators
and their validation under LDC conditions is needed
Upper Pleistocene Stratigraphy, Paleoecology, and Archaeology of the Northern Yukon Interior, Eastern Beringia. I. Bonnet Plume Basin
New stratigraphic and chronometric data show that Bonnet Plume Basin, in northeastern Yukon Territory, was glaciated in late Wisconsinan time rather than during an earlier advance of Laurentide ice. This conclusion has important ramifications not only for the interpretation of all-time glacial limits farther north along the Richardson Mountains but also for non-glaciated basins in the Porcupine drainage to the northwest. The late Wisconsinan glacial episode in Bonnet Plume Basin is here named the Hungry Creek advance after the principal Quaternary section in the basin. Sediments beneath the till at Hungry Creek have produced well-produced pollen, plant macrofossils, insects, and a few vertebrate remains. The plant and invertebrate fossils provide a detailed, if temporally restricted, record of a portion of the mid-Wisconsinan interstadial, while the vertebrate fossils include the oldest Yukon specimen of the Yukon wild ass. Some of the mid-Wisconsinan sediments have also yielded distinctive chert flakes that represent either a previously unreported product of natural fracturing or a by-product of stone tool manufacture by human residents of Bonnet Plume Basin. In addition to presenting new data on these diverse but interrelated topics, this paper serves as an introduction to a series of reports that will treat in turn the Upper Pleistocene record of Bluefish, Old Crow, and Bell basins, respectively. 
Antennas for the detection of radio emission pulses from cosmic-ray induced air showers at the Pierre Auger Observatory
The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna sensor. As the ultra-wideband reception of pulses is not widely discussed in antenna literature, we review the relevant antenna characteristics and enhance theoretical considerations towards the impulse response of antennas including polarization effects and multiple signal reflections. On the basis of the vector effective length we study the transient response characteristics of three candidate antennas in the time domain. Observing the variation of the continuous galactic background intensity we rank the antennas with respect to the noise level added to the galactic signal
Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET
The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR
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Living well with dementia: An exploratory matched analysis of minority ethnic and white people with dementia and carers participating in the IDEAL programme
YesThe increasing heterogeneity of the population of older people is reflected in an increasing number of people with dementia and carers drawn from minority ethnic groups. Data from the IDEAL study are used to compare indices of 'living well' among people with dementia and carers from ethnic minority groups with matched white peers.
We used an exploratory cross-sectional case-control design to compare 'living well' for people with dementia and carers from minority ethnic and white groups. Measures for both groups were quality of life, life satisfaction, wellbeing, loneliness, and social isolation and, for carers, stress, relationship quality, role captivity and caring competence.
The sample of people with dementia consisted of 20 minority ethnic and 60 white participants and for carers 15 and 45 respectively. People with dementia from minority ethnic groups had poorer quality of life (-4.74, 95% CI: -7.98 to -1.50) and higher loneliness (1.72, 95% CI: 0.78-2.66) whilst minority ethnic carers had higher stress (8.17, 95% CI: 1.72-14.63) and role captivity (2.00, 95% CI: 0.43-3.57) and lower relationship quality (-9.86, 95% CI: -14.24 to -5.48) than their white peers.
Our exploratory study suggests that people with dementia from minority ethnic groups experience lower quality of life and carers experience higher stress and role captivity and lower relationship quality than their white peers. Confirmatory research with larger samples is required to facilitate analysis of the experiences of specific minority ethnic groups and examine the factors contributing to these disadvantages.Economic and Social Research Council. National Institute for Health and Care Research. Grant Number: ES/L001853/
Ecosystem-based management for military training, biodiversity, carbon storage and climate resiliency on a complex coastal land/water-scape
The Defense Coastal/Estuarine Research Program (DCERP) was a 10-year multi-investigator project funded by the Department of Defense to improve understanding of ecosystem processes and their interactions with natural and anthropogenic stressors at the Marine Corps Base Camp Lejeune (MCBCL) located in coastal North Carolina. The project was aimed at facilitating ecosystem-based management (EBM) at the MCBCL and other coastal military installations. Because of its scope, interdisciplinary character, and duration, DCERP embodied many of the opportunities and challenges associated with EBM, including the need for explicit goals, system models, long-term perspectives, systems complexity, change inevitability, consideration of humans as ecosystem components, and program adaptability and accountability. We describe key elements of this program, its contributions to coastal EBM, and its relevance as an exemplar of EBM
Drugs and supplements in amateur boxing: pugilistic amateurism and ideologies of performance
This research, which is based on the thoughts and experiences of coaches, athletes, officials and others involved in amateur boxing, explores the use of supplements, recreational and performance-enhancing drugs in the sport. After providing some context through a discussion of ideologies that shape elite sport, some key methodological issues are briefly described. The findings explore the manner in which ideologies of performance are shaped in relation to the notion of 'pugilistic amateurism'. In this way, the paper maps out a theoretical scaffold that can be used to understand the manner in which 'old school' training methods and participation in sport align with 'traditional' understandings of work-class manhood to produce an ideological tension with a win-at-all-costs mentality. This sheds light on the ways that boxing gyms might be understood as havens where drugs use can be resisted at the same times as potentially positive behaviours can be learned
Estimativa da geração de resíduos de equipamentos elétricos e eletrônicos de origem domiciliar: proposição de método e aplicação ao município de São Paulo, São Paulo, Brasil
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