The dual-phase xenon time projection chamber (TPC) is a powerful tool for direct-detection experiments searching for WIMP dark matter, other dark matter models, and neutrinoless double-beta decay. ...Successful operation of such a TPC is critically dependent on the ability to hold high electric fields in the bulk liquid, across the liquid surface, and in the gas. Careful design and construction of the electrodes used to establish these fields is therefore required. We present the design and production of the LUX-ZEPLIN (LZ) experiment’s high-voltage electrodes, a set of four woven mesh wire grids. Grid design drivers are discussed, with emphasis placed on design of the electron extraction region. We follow this with a description of the grid production process and a discussion of steps taken to validate the LZ grids prior to integration into the TPC.
Findings from several experimental studies in animals have suggested a protective action of testosterone on kidney function, but hard evidence for such an association in humans is scarce. We examined ...the association between testosterone levels and kidney function among adult men living in super-aged communities.
We conducted cross-sectional study involving residents aged 40-80 years who participated in annual health check-ups in 2 communities. A total of 1031 men were recruited in 2010. Main exposure was salivary testosterone (sT) levels measured using an enzyme-linked immunosorbent assay. Main outcome was estimated glomerular filtration rate (eGFR) determined by age, gender, and serum creatinine levels.
For the 848 participants analyzed, median age and eGFR were 69 years and 69.1 mL/min/1.73 m(2), respectively. On comparison of 90th-percentile sT levels with lower levels, our general linear model with restricted cubic splines showed that lower sT levels were associated with decreased eGFR after adjustment for sociodemographic characteristics, comorbidities, and blood pressure. For example, fifth percentile sT was associated with decreased eGFR, with a difference in eGFR -3.43 mL/min/1.73 m(2) (95% confidence interval, CI -6.02 to -0.84) comparable in magnitude to the reduction in eGFR observed for a 6-year increase in age in our population. The association between low testosterone levels and decreased eGFR remained similar even when analyses were restricted to participants aged over 60 years (734 participants, median age 71 years).
Results from our study indicated that having low testosterone levels was independently associated with reduced eGFR in adult men. Our finding of this association between low testosterone levels and reduced kidney function needs to be corroborated among persons with chronic kidney disease or in a longitudinal study.
The dual-phase xenon time projection chamber (TPC) is a powerful tool for direct-detection experiments searching for WIMP dark matter, other dark matter models, and neutrinoless double-beta decay. ...Successful operation of such a TPC is critically dependent on the ability to hold high electric fields in the bulk liquid, across the liquid surface, and in the gas. Careful design and construction of the electrodes used to establish these fields is therefore required. We present the design and production of the LUX-ZEPLIN (LZ) experiment's high-voltage electrodes, a set of four woven mesh wire grids. Grid design drivers are discussed, with emphasis placed on design of the electron extraction region. We follow this with a description of the grid production process and a discussion of steps taken to validate the LZ grids prior to integration into the TPC.
The dual-phase xenon time projection chamber (TPC) is a powerful tool for direct-detection experiments searching for WIMP dark matter, other dark matter models, and neutrinoless double-beta decay. ...Successful operation of such a TPC is critically dependent on the ability to hold high electric fields in the bulk liquid, across the liquid surface, and in the gas. Careful design and construction of the electrodes used to establish these fields is therefore required. We present the design and production of the LUX-ZEPLIN (LZ) experiment's high-voltage electrodes, a set of four woven mesh wire grids. Grid design drivers are discussed, with emphasis placed on design of the electron extraction region. Here, we follow this with a description of the grid production process and a discussion of steps taken to validate the LZ grids prior to integration into the TPC.
The dual-phase xenon time projection chamber (TPC) is a powerful tool for direct-detection experiments searching for WIMP dark matter, other dark matter models, and neutrinoless double-beta decay. ...Successful operation of such a TPC is critically dependent on the ability to hold high electric fields in the bulk liquid, across the liquid surface, and in the gas. Careful design and construction of the electrodes used to establish these fields is therefore required. We present the design and production of the LUX-ZEPLIN (LZ) experiment's high-voltage electrodes, a set of four woven mesh wire grids. Grid design drivers are discussed, with emphasis placed on design of the electron extraction region. Here, we follow this with a description of the grid production process and a discussion of steps taken to validate the LZ grids prior to integration into the TPC.
Abstract
A key feature of quantum spin liquids is the predicted formation of fractionalized excitations. They are expected to produce changes in the physical response, providing a way to observe the ...quantum spin liquid state
1
. In the honeycomb magnet α-RuCl
3
, a quantum spin liquid has been proposed to explain the behaviour observed on applying an in-plane magnetic field
H
||
. Previous work reported that the thermal Hall conductivity took on a half-integer quantized value and suggested this as a signature of a fractionalized Majorana edge mode predicted to exist in Kitaev quantum spin liquids
2
. However, the temperature and magnetic-field range of the half-quantized signal
2–4
and its association with Majorana edge modes are still under debate
5,6
. Here we present a comprehensive study of the thermal Hall conductivity in α-RuCl
3
showing that approximately half-integer quantization exists in an extended region of the phase diagram, particularly across a plateau-like parameter regime for
H
||
exceeding 10 T and temperature below 6.5 K. At lower fields, the thermal Hall conductivity exhibits correlations with complex anomalies in the longitudinal thermal conductivity and magnetization, and is suppressed by cooling to low temperatures. Our results can be explained by the existence of a topological state in magnetic fields above 10 T.
The exactly solvable Kitaev model of two-dimensional honeycomb magnets has a quantum spin liquid phase characterized by the emergence of fractionalized Majorana fermion excitations. In the ...paramagnetic state of α-RuCl3 at high magnetic fields, a half-integer quantization of thermal Hall conductivity has been reported as a signature of edge currents carried by Majorana fermions, but the bulk nature of this state remains unconfirmed. Here, by measuring the heat capacity for different in-plane rotations of an applied magnetic field, we find strongly angle-dependent low-energy excitations in bulk α-RuCl3. The excitation gap has a sextuple node structure, and the gap amplitude increases with the field, as expected for itinerant Majorana fermions in the Kitaev model. Our thermodynamic observations of the opening and closing of the bulk gap according to the magnetic-field direction fully correspond with changes in the edge transport. Moreover, the behaviour at higher magnetic fields where the quantum thermal Hall effect vanishes is consistent with a nematic quantum spin liquid state with two-fold rotational symmetry.α-RuCl has a quantum magnetic phase that may be a spin liquid hosting Majorana fermion excitations. Heat capacity measurements show an anisotropic dependence on magnetic-field direction, consistent with predictions for the putative spin liquid.
Parkinson’s disease is a degenerative, chronic and progressive disease, characterized by motor dysfunctions. Patients also exhibit non-motor symptoms, such as affective and sleep disorders. Sleep ...disorders can potentiate clinical and neuropathological features and lead to worse prognosis. The goal of this study was to evaluate the effects of sleep deprivation (SD) in mice submitted to a progressive pharmacological model of Parkinsonism (chronic administration with a low dose of reserpine). Male Swiss mice received 20 injections of reserpine (0.1 mg/kg) or vehicle, on alternate days. SD was applied before or during reserpine treatment and was performed by gentle handling for 6 h per day for 10 consecutive days. Animals were submitted to motor and non-motor behavioral assessments and neurochemical evaluations. Locomotion was increased by SD and decreased by reserpine treatment. SD during treatment delayed the onset of catalepsy, but SD prior to treatment potentiated reserpine-induced catalepsy. Thus, although SD induced an apparent beneficial effect on motor parameters, a delayed deleterious effect on alterations induced by reserpine was found. In the object recognition test, both SD and reserpine treatment produced cognitive deficits. In addition, the association between SD and reserpine induced anhedonic-like behavior. Finally, an increase in oxidative stress was found in hippocampus of mice subjected to SD, and tyrosine hydroxylase immunoreactivity was reduced in substantia nigra of reserpine-treated animals. Results point to a possible late effect of SD, aggravating the deficits in mice submitted to the reserpine progressive model of PD.
ABSTRACT
We present the optical transmission spectrum of the hot Jupiter WASP-104b based on one transit observed by the blue and red channels of the Double Spectrograph (DBSP) at the Palomar 200-inch ...telescope and 14 transits observed by the MuSCAT2 four-channel imager at the 1.52-m Telescopio Carlos Sánchez. We also analyse 45 additional K2 transits, after correcting for the flux contamination from a companion star. Together with the transit light curves acquired by DBSP and MuSCAT2, we are able to revise the system parameters and orbital ephemeris, confirming that no transit timing variations exist. Our DBSP and MuSCAT2 combined transmission spectrum reveals an enhanced slope at wavelengths shorter than 630 nm and suggests the presence of a cloud deck at longer wavelengths. While the Bayesian spectral retrieval analyses favour a hazy atmosphere, stellar spot contamination cannot be completely ruled out. Further evidence, from transmission spectroscopy and detailed characterization of the host star’s activity, is required to distinguish the physical origin of the enhanced slope.
Purpose - This study aims to assess and evaluate the disaster management system in Sri Lanka and the capacity of a local community to respond to natural disasters, and to propose a strategy for the ...dissemination of tsunami knowledge while raising public awareness of tsunami disasters.Design methodology approach - The survey focused on three clusters of respondents and different methodologies were adopted to collect data from each group, as follows: residents: questionnaires followed by a structured interview; school children: questionnaires completed under the guidance of a teacher; government officials: questionnaires completed independently by respondents, and followed up with unstructured interviews with officials in charge of disaster related activities.Findings - The results of the survey of residents indicate that; more than 90 percent of residents lacked tsunami knowledge prior to the 2004 tsunami; the main source of information during the disaster was direct information from family and neighbors; school education is important for raising awareness of disaster reduction; and an early warning system is a key requirement for reducing damage in the future. The school surveys reveal that; about 30 percent of school children do not yet understand what causes a tsunami; 90 percent of school children have a keen interest in studying natural disasters; comprehensive disaster education has not been provided; and audio-visual means are thought to be the most effective tool for disaster education. The survey of officials shows that; seminars and drills on natural disaster have not thus far been conducted among general officials other than the military and police; measures need to be developed to safeguard the interests of tourists; and sirens, TV, and radio broadcasts are effective tools for disseminating disaster warnings to residents.Practical implications - Based on the findings of the questionnaire and interview surveys, the following recommendations are proposed for disseminating knowledge and raising public awareness of tsunami disasters: promote disaster education at the school level; implement community-level public awareness programs; enhance information management systems; and improve coordination mechanisms within the disaster management system.Originality value - At present, this is the only study being conducted whose goal is to quantitatively evaluate public awareness of natural disasters and disaster management in Sri Lanka.
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