2,107 research outputs found
Parametric test of a zirconium (4) oxide-polyacrylic acid dual layer hyperfiltration membrane with spacecraft washwater
Performance data consisting of solute rejections and product flux were measured, as dependent on the operation parameters. These parameters and ranges were pressure (500,000 n/m2 to 700,000 n/m2), temperature (74 C to 95 C), velocity (1.6 M/sec to 10 M/sec), and concentration (up to 14x). Tests were carried out on analog washwater. Data presented include rejections of organic materials, ammonia, urea, and an assortment of ions. The membrane used was deposited in situ on a porcelain ceramic substrate
Sexual Hookups via Dating Apps: A Qualitative Study Exploring the Experiences of Black Men Who Have Sex with Men in Florida
Background: Sexual hookups via social media dating apps have been understudied among Black men who have sex with men (BMSM). Purpose: The objective of this qualitative study was to explore the role of dating apps on hookup culture and to describe the sexual experiences among BMSM in Florida. Specifically, this research delves into various sexual hookup themes. Methods: Seventeen semi-structured interviews were conducted with BMSM participants aged 18 to 25 in Florida who self-identified as frequent dating app users. A grounded theory approach was applied to thematically analyze the hookup encounters and the factors that drive these perceptions and experiences among BMSM. QSR NVIVO 12 was used to code, categorize, and collect emergent themes. Results: Three major themes emerged depicting the complexities of hookup culture using social media dating applications among BMSM. 1. Positive hookup experiences were linked to feelings of âno strings attachedâ to some participants, while others associated this positive experience to the use of alcohol and drugs; 2. Negative hookup experiences revolved around miscommunication on sexual roles, catfishing, and disclosure of HIV status; 3. Psychological aspects of hookups were centered on feelings of regret, disbelief, and disgust after a sexual hookup encounter. Discussion: Understanding BMSM hookup culture could aid in the development of prioritized evidence-based interventions for behavioral change to improve safer sexual health encounters among this vulnerable populatio
Hardware Deployment of Hybrid PQC
In this work, we present a small architecture for quantum-safe hybrid key exchange targeting ECDH and SIKE. This is the first known hardware implementation of ECDH/SIKE-based hybrid key exchange in the literature. We propose new ECDH and EdDSA parameter sets defined over the SIKE primes. As a proof-of-concept, we evaluate SIKEX434, a hybrid PQC scheme composed of SIKEp434 and our proposed ECDH scheme X434 over a new, low-footprint architecture. Both schemes utilize the same 434-bit prime to save area. With only 1663 slices on a small Artix-7 device, our SIKE architecture can compute an entire hybrid key exchange in 320 ms. This is the smallest SIKE architecture in the literature. The hybrid SIKEX434 adds approximately 16% communication overhead and 10% latency overhead over SIKEp434. The additional overhead to support multiple primes indicates the need for new standardized ECC parameters for area-efficient designs in the future
Mental health stigma at primary health care centres in Lebanon: qualitative study
Background: Mental health-related stigma is a global public health concern and a major barrier to seeking care. In this study, we explored the role of stigma as a barrier to scaling up mental health services in primary health care (PHC) centres in Lebanon. We focused on the experiences of Healthcare Providers (HCPs) providing services to patients with mental health conditions (MHCs), the views of policy makers, and the perceptions of stigma or discrimination among individuals with MHCs. This study was conducted as part of INDIGO-PRIMARY, a larger multinational stigma reduction programme.
Methods: Semi-structured qualitative interviews (n = 45) were carried out with policy makers (n = 3), PHC management (n = 4), PHC staff (n = 24), and service users (SUs) (n = 14) between August 2018 and September 2019. These interviews explored mental health knowledge, attitudes and behaviour of staff, challenges of providing treatment, and patient outcomes. All interviews were coded using NVivo and a thematic coding framework.
Results: The results of this study are presented under three themes: (1) stigma at PHC level, (2) stigma outside PHC centres, and (3) structural stigma. SUs did not testify to discrimination from HCPs but did describe stigmatising behaviour from their families. Interestingly, at the PHC level, stigma reporting differed among staff according to a power gradient. Nurses and social workers did not explicitly report incidents of stigma but described patients with MHCs as uncooperative, underscoring their internalized negative views on mental health. General practitioners and directors were more outspoken than nurses regarding the challenges faced with mental health patients. Mental health professionals revealed that HCPs still hold implicitly negative views towards patients with MHCs however their attitude has improved recently. Our analysis highlights five layers of stigma affecting SUs.
Conclusion: This qualitative study reveals that stigma was still a key concern that affects patients with MHC. SUs reported experiencing overt stigmatising behaviour in the community but less explicit discrimination in a PHC setting. Our findings emphasise the importance of (1) combatting structural stigma through legal reform, (2) addressing interpersonal stigma, (3) committing PHC management to deliver high quality mental health integrated services, and (4) reducing intrapersonal stigma by building public empathy.
Keywords: Mental health Stigma; Primary health care (PHC); Qualitative researc
Biomechanical and Fluoroscopic Study of a Continuously Expandable Interbody Spacer Concerning Its Role in Insertion Force and Segmental Kinematics
Study Design In vitro cadaveric study. Purpose To compare biomechanical performance, trial and implant insertion, and disc distraction during implant placement, when two interbody devices, an in situ continuously expandable spacer (CES) and a traditional static spacer (SS), were used for transforaminal lumbar interbody fusion. Overview of Literature Severe degenerative disc diseases necessitate surgical management via large spacers to increase the disc space for implants. Next-generation interbody devices that expand in situ minimize insertion forces, optimize fit between vertebral endplates, and limit nerve root retraction. However, the literature lacks characterization of insertion forces as well as details on other parameters of expandable and static spacers. Methods Ten cadaveric segments (L5âS1) were divided into two groups (n=5) and implanted with either CES or SS. Each specimen experienced unconstrained pure moment of ±6 Nm in flexionâextension, lateral bending, and axial rotation to assess the contribution of CES and SS implants in biomechanical performance. Radiographic analysis was performed during trial and implant insertion to measure distraction during spacer insertion at the posterior, central, and anterior disc regions. Pressure sensors measured the force of trial and implant insertion. Results Biomechanical analysis showed no significant differences between CES and SS in all planes of motion. A total 2.6±0.9 strikes were required for expandable spacer trials insertion and 2.6±0.5 strikes for CES insertion. A total of 8.4±3.8 strikes were required to insert SS trials and 4.2±1.6 strikes for SS insertion. The total force per surgery was 330 N for CES and 635 N for SS. Fluoroscopic analysis revealed a significant reduction in distraction during implant insertion at the posterior and anterior disc regions (CES, 0.58 and 0.14 mm; SS, 1.04 and 0.78 mm, respectively). Conclusions Results from the three study arms reveal the potential use of expandable spacers. During implant insertion, CESs provided similar stability, required less insertion force, and significantly reduced over-distraction of the annulus compared with SS
Dwarf Galaxies in CDM, WDM, and SIDM: Disentangling Baryons and Dark Matter Physics
We present a suite of FIRE-2 cosmological zoom-in simulations of isolated
field dwarf galaxies, all with masses of M at , across a range of dark matter models. For the
first time, we compare how both self-interacting dark matter (SIDM) and/or warm
dark matter (WDM) models affect the assembly histories as well as the central
density structure in fully hydrodynamical simulations of dwarfs. Dwarfs with
smaller stellar half-mass radii (r pc) have lower
ratios, reinforcing the idea that smaller dwarfs
may reside in halos that are more massive than is naively expected. The
majority of dwarfs simulated with self-interactions actually experience
contraction of their inner density profiles with the addition of baryons
relative to the cores produced in dark-matter-only runs, though the simulated
dwarfs are always less centrally dense than in CDM. The
Vr relation across all simulations is generally consistent
with observations of Local Field dwarfs, though compact objects such as Tucana
provide a unique challenge. Spatially-resolved rotation curves in the central
regions ( pc) of small dwarfs could provide a way to distinguish between
CDM, WDM, and SIDM, however: at the masses probed in this simulation suite,
cored density profiles in dwarfs with small r values can only originate
from dark matter self-interactions.Comment: 16 pages, 12 figures. V2: matches version accepted by MNRA
Sex differences in the experience of COVID-19 post-traumatic stress symptoms by adults in South Africa
Evaluation of a standard provision versus an autonomy promotive exercise referral programme: rationale and study design
Background
The National Institute of Clinical Excellence in the UK has recommended that the effectiveness of ongoing exercise referral schemes to promote physical activity should be examined in research trials. Recent empirical evidence in health care and physical activity promotion contexts provides a foundation for testing the utility of a Self Determination Theory (SDT) -based exercise referral consultation.
Methods/Design
Design: An exploratory cluster randomised controlled trial comparing standard provision exercise on prescription with a Self Determination Theory-based (SDT) exercise on prescription intervention.
Participants: 347 people referred to the Birmingham Exercise on Prescription scheme between November 2007 and July 2008. The 13 exercise on prescription sites in Birmingham were randomised to current practice (n=7) or to the SDT-based intervention (n=6).
Outcomes measured at 3 and 6-months: Minutes of moderate or vigorous physical activity per week assessed using the 7-day Physical Activity Recall; physical health: blood pressure and weight; health status measured using the Dartmouth CO-OP charts; anxiety and depression measured by the Hospital Anxiety and Depression Scale and vitality measured by the subjective vitality score; motivation and processes of change: perceptions of autonomy support from the advisor, satisfaction of the needs for competence, autonomy, and relatedness via physical activity, and motivational regulations for exercise.
Discussion
This trial will determine whether an exercise referral programme based on Self Determination Theory increases physical activity and other health outcomes compared to a standard programme and will test the underlying SDT-based process model (perceived autonomy support, need satisfaction, motivation regulations, outcomes) via structural equation modelling.
Trial registration
The trial is registered as Current Controlled trials ISRCTN07682833
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