The DARWIN observatory is a proposed next-generation experiment with 40 tonnes of liquid xenon as an active target in a time projection chamber. To study challenges related to the construction and ...operation of a multi-tonne scale detector, we have designed and constructed a vertical, full-scale demonstrator for the DARWIN experiment at the University of Zurich. Here, we present the first results from a several-months run with
343
kg
of xenon and electron drift lifetime and transport measurements with a
53
cm
tall purity monitor immersed in the cryogenic liquid. After
88
days
of continuous purification, the electron lifetime reached a value of
(
664
±
23
)
μ
s
. We measured the drift velocity of electrons for electric fields in the range (25–75) V/cm, and found values consistent with previous measurements. We also calculated the longitudinal diffusion constant of the electron cloud in the same field range, and compared with previous data, as well as with predictions from an empirical model.
To investigate the physical properties of commercially available multipurpose soft contact lens solutions in Ghana.
pH (Kelilong ICL-099 pH meter, China), osmolality (OSMOMAT 3000, GONOTEC, Germany), ...surface tension (Sigma 700 Tensiometer, Sweden), and viscosity (CFOC-200 Viscometer, Cannon Company, USA) of various soft contact lens multipurpose solutions (MPS) were measured in triplicates at room temperature. Viscosity measurements were also taken at 34 °C ocular surface temperature. The solutions examined were Opti-Free Replenish (OFR), Trufresh (TF), Avizor (AV), Freshlook (FL), and Refresh (RF).
Several solutions were largely hypo-osmotic in the range of 108–231 mOsm/kg, the exception being Avizor, which had osmolality values that were closer to human tears (301 ± 0.58 mOsm/kg). The range of pH values of the solutions (6.33–8.24, mean (SD) = 7.53 ± 0.18) fell within the reported tolerable range for the ocular surface (6.20–9.00). Surface tension values ranged from 35.86 to 42.27 mNm with a mean of 38.49 ± 2.32 mNm. The average viscosity of most solutions at room temperature (25 °C) was 1.44 ± 0.49 cP with a range of 1.04–2.15 cP. Significantly lower values ranging from 0.79 to 1.58 cP were obtained at ocular surface temperature (34 °C), p = 0.0001).
The physical properties of many of the solutions used as MPS in Ghana are markedly variable. Nevertheless, pH, surface tension, and viscosity fall within the acceptable limits of ocular physiological tolerance; except for osmolality, which majority were outside the reported tolerable range for the ocular surface. This information may partly explain the reason some patients exhibit strong preferences for certain care systems and should aid clinical decision-making when prescribing eye care systems to patients.
•We evaluated the physical properties of multipurpose soft contact lens solutions in Ghana.•There were unique variations in the physical properties of the tested solutions.•Many solutions exhibited hypo-osmotic values outside the range for the ocular surface.•However, viscosity, pH, and surface tension were within acceptable eye ranges.•Findings offer evidence to guide patient preferences in prescribing eye care systems.
Posttraumatic Stress Disorder (PTSD) impacts both individual and relational functioning. Veteran couples are at increased risk of relationship distress due to military stressors such as deployment, ...family reintegration, and traumatic stress. Although both Cognitive-Behavioral Conjoint Therapy (CBCT) and its brief version (bCBCT) consistently have large effects on reducing PTSD symptoms, these treatments have more variable effects on relational outcomes. Given the impact of relationship functioning on the overall health of veterans, improving the effect of PTSD treatments on relationship functioning is an essential area of research. One promising path is the role of MDMA (3,4-methylenedioxymethamphetamine)-assisted therapy in augmenting the relational impact of established therapeutic interventions such as bCBCT.
This is a single site, open-label study assessing the preliminary efficacy, safety, and acceptability of MDMA-assisted therapy in combination with bCBCT in 8 veterans with PTSD and their intimate partners (N = 16). Therapy teams trained in bCBCT and MDMA-assisted therapy will deliver bCBCT combined with two MDMA sessions and two couple emotion focused integration sessions. PTSD symptom severity and relationship functioning outcomes will be evaluated.
This is the first study to examine the efficacy of MDMA-assisted bCBCT for improving PTSD and relationship functioning among a sample of U.S. military veterans and their partners. This project could provide an opportunity to pilot a scalable model of treating PTSD within the Veterans Affairs healthcare system and leverage the benefits of MDMA for veterans with PTSD, as well as the downstream benefits to their partner on both individual and relationship functioning. ClinicalTrials.gov Identifier: NCT05979844.
Women in their reproductive years make up about 50% of all HIV-positive persons globally. These women, just as their HIV-negative counterparts, wield the right to procreate. However, HIV infection ...and lack of appropriate information on reproductive options may negatively impact women's procreative decision-making. This study assessed fertility intentions of HIV-positive women receiving antiretroviral therapy (ART) in southern Ghana. Quantitative methods were used to collect data from HIV-positive women receiving ART at four treatment centers. HIV-positive aged 18-49 years, and receiving ART were selected using systematic random sampling technique. Three hundred eighteen women were interviewed after informed consent. We used univariate analysis to generate descriptive tabulations for key variables. Bivariate analysis and logistic regression modeling respectively produced unadjusted and adjusted associations between background attributes of respondents and their childbearing decision-making. All analyses were performed using IBM SPSS Statistics for Windows, Version 20.0. Irrespective of age, reproductive history, and duration of HIV diagnosis, 46% of the women were desirous of procreating. The bivariate level analysis shows that women in their late reproductive ages (30-39 years) had the strongest desire to procreate (p < 0.001). After controlling for a number of covariates, primiparous and secundiparious women were about twice as likely to desire children (aOR = 2.553; 95% CI 1.480-4.401), and so were women aged 30-39 years (aOR = 2.149; 95% CI 1.202-3.843). Of 54% women who do not wish to procreate, achievement of desired family size (64.3%) was more popular a reason than fear of vertical transmission of HIV (7.5%), poor health status (5%), and pregnancy-related complications (1.6%).
We report on a blinded analysis of low-energy electronic recoil data from the first science run of the XENONnT dark matter experiment. Novel subsystems and the increased 5.9 ton liquid xenon target ...reduced the background in the (1, 30) keV search region to (15.8±1.3) events/(ton×year×keV), the lowest ever achieved in a dark matter detector and ∼5 times lower than in XENON1T. With an exposure of 1.16 ton-years, we observe no excess above background and set stringent new limits on solar axions, an enhanced neutrino magnetic moment, and bosonic dark matter.
Delayed single- and few-electron emissions plague dual-phase time projection chambers, limiting their potential to search for light-mass dark matter. This paper examines the origins of these events ...in the XENON1T experiment. Characterization of the intensity of delayed electron backgrounds shows that the resulting emissions are correlated, in time and position, with high-energy events and can effectively be vetoed. In this work we extend previous S2-only analyses down to a single electron. From this analysis, after removing the correlated backgrounds, we observe rates <30 events/(electron×kg×day) in the region of interest spanning 1 to 5 electrons. We derive 90% confidence upper limits for dark matter-electron scattering, first direct limits on the electric dipole, magnetic dipole, and anapole interactions, and bosonic dark matter models, where we exclude new parameter space for dark photons and solar dark photons.
Recharge estimation is important to the effective development and management of groundwater resources, since it forms the basis for assigning abstraction rates. This study applied the water table ...fluctuation method and chloride mass balance approach to estimate groundwater recharge in the Densu basin, identified as the most problematic and vulnerable catchment in Ghana, using chloride and water level data from 10 monitoring wells. In general, the results revealed seasonal and spatial variation in groundwater recharge in the basin, with a north-south decreasing trend. The chloride mass balance approach and water level fluctuation method revealed average groundwater recharge of 70 mm and 62 mm/year respectively. With the total groundwater abstraction in the basin estimated to be only 8% of the annual recharge rate, the potential for groundwater use in the basin is great, granted adequate water quality assessment supports the useable quantity available in the basin.
•Recharge is crucial to the overall management of groundwater resources in any area.•Recharge was estimated using the water table fluctuations and chloride mass balance.•The variation in the recharge estimates increases spatially from south to north of the basin.•There is a huge potential for increased abstraction of groundwater for multi-purpose use in the basin.
Abstract
The DARWIN observatory is a proposed next-generation experiment to search for particle dark matter and for the neutrinoless double beta decay of
$$^{136}$$
136
Xe. Out of its 50 t total ...natural xenon inventory, 40 t will be the active target of a time projection chamber which thus contains about 3.6 t of
$$^{136}$$
136
Xe. Here, we show that its projected half-life sensitivity is
$$2.4\times {10}^{27}\,{\hbox {year}}$$
2.4
×
10
27
year
, using a fiducial volume of 5 t of natural xenon and 10 year of operation with a background rate of less than 0.2 events/(t
$$\cdot $$
·
year) in the energy region of interest. This sensitivity is based on a detailed Monte Carlo simulation study of the background and event topologies in the large, homogeneous target. DARWIN will be comparable in its science reach to dedicated double beta decay experiments using xenon enriched in
$$^{136}$$
136
Xe.
We detail the sensitivity of the proposed liquid xenon DARWIN observatory to solar neutrinos via elastic electron scattering. We find that DARWIN will have the potential to measure the fluxes of five ...solar neutrino components:
pp
,
7
Be,
13
N,
15
O and
pep
. The precision of the
13
N,
15
O and
pep
components is hindered by the double-beta decay of
136
Xe and, thus, would benefit from a depleted target. A high-statistics observation of
pp
neutrinos would allow us to infer the values of the electroweak mixing angle,
sin
2
θ
w
, and the electron-type neutrino survival probability,
P
ee
, in the electron recoil energy region from a few keV up to 200 keV for the first time, with relative precision of 5% and 4%, respectively, with 10 live years of data and a 30 tonne fiducial volume. An observation of
pp
and
7
Be neutrinos would constrain the neutrino-inferred solar luminosity down to 0.2%. A combination of all flux measurements would distinguish between the high- (GS98) and low-metallicity (AGS09) solar models with 2.1–2.5
σ
significance, independent of external measurements from other experiments or a measurement of
8
B neutrinos through coherent elastic neutrino-nucleus scattering in DARWIN. Finally, we demonstrate that with a depleted target DARWIN may be sensitive to the neutrino capture process of
131
Xe.
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