•Automated thermostat system controlled pavement heating and solar thermal collection.•In clear sky conditions, the HP-ETCs collected an average daily power of 2.7 kW.•Average solar heating operation ...raised stored fluid temperature 11.3 °C in 7 h.•SWHS provided adequate energy to maintain above freezing slab surface temperature.
In this paper, a solar water heating system (SWHS) with heat-pipe evacuated tube collectors (HP-ETC) is experimentally evaluated as a hydronic heated pavement system heat source. Outdoor testing in Fayetteville, Arkansas was performed over the 2017–2018 winter season. The data collected in this study were used to evaluate pavement heating and snow-melting performance. A dual automated thermostat heating system was incorporated to (1) control pavement heating operation to maintain an anti-icing surface temperature (2 °C), and (2) control direct fluid heat transfer from the HP-ETC to the storage tank. Results showed that the SWHS with HP-ETC provided adequate thermal energy to maintain two 3.05 m × 1.22 m × 0.13 m concrete slab surfaces above freezing temperature. During a 6 h man-made snowfall test, the pavement maintained a snow-free surface. The maximum storage tank fluid temperature recorded was 74.0 °C during the test period. In clear sky conditions, the HP-ETC collected an average daily power of 2.7 kW.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPUK, ZAGLJ, ZRSKP
This paper explores how individual characteristics and national-level variables affect perceptions toward whether individual success depends on luck and connections or hard work. Drawing on five ...waves of World Values Survey (WVS) data on more than 175,000 respondents in 85 countries, we find that demographic factors and socioeconomic variables such as age, gender, income, and employment status are strongly associated with an individual's view on luck versus hard work. For example, women are more likely to view luck as the primary factor determining success in the long run. In addition, individuals in countries with better macroeconomic conditions measured by GDP per capita and its growth rate seem to associate success more with luck than with hard work compared to individuals in other countries. Our results from multilevel ordered logistic regressions also suggest that differences in personal traits account for approximately 90% of the variations in respondents' perceptions observed in our sample. The remaining 10% is due to differences in various country-level traits other than our GDP controls.
Full text
Available for:
BFBNIB, IZUM, KILJ, NUK, PILJ, SAZU, UL, UM, UPUK
Compared to women, South African men are less likely to know their HIV status (78% vs. 89%), have suppressed viral loads (82% vs. 90%), or access HIV prevention services. To achieve epidemic control ...where heterosexual sexual behavior drives transmission, interventions to improve the uptake of HIV testing services (HTS) and prevention services must also target cis-gendered, heterosexual men. There is limited understanding of these men's needs and wants with regards to accessing pre-exposure prophylaxis (PrEP).
Adult men (≥ 18 years) from a peri-urban community in Buffalo City Municipality were offered community-based HTS. Those who received a negative HIV test result were offered community-based, same-day oral PrEP initiation. Men initiating PrEP were invited to participate in a study exploring men's HIV prevention needs and reasons for initiating PrEP. An in-depth interview guide, developed using the Network-Individual-Resources model (NIRM), explored men's perceived HIV acquisition risk, prevention needs, and preferences for PrEP initiation. Interviews were conducted by a trained interviewer in isiXhosa or English, audio-recorded and transcribed. Thematic analysis was used, guided by the NIRM to generate findings.
Twenty-two men (age range 18-57 years) initiated PrEP and consented to study participation. Men reported elevated HIV acquisition risk associated with alcohol use and condom-less sex with multiple partners as facilitators driving PrEP initiation. They anticipated social support from family members, their main sexual partner and close friends for their PrEP use, and discussed other men as important sources of support for PrEP initiation. Nearly all men expressed positive views of people using PrEP. Participants believed HIV testing would be a barrier for men interested in accessing PrEP. Men recommended that access to PrEP be convenient, rapid, and community-based (i.e., not clinic-based).
Self-perceived risk for HIV acquisition was a major facilitator for men's PrEP initiation. Although men expressed positive perceptions of PrEP users, they noted that HIV testing may be a barrier to PrEP initiation. Finally, men recommended convenient access points to facilitate PrEP initiation and sustained use. Gender-responsive interventions tailored to men's needs, wants, and voices will facilitate their uptake of HIV prevention services, and help to end the HIV epidemic.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Snow and ice pose a significant risk for aircraft ground operation safety. Ploughing and chemical treatment are used for snow removal, but yield long-term detrimental impacts to the airfield ...infrastructure and environment. A proof-of-concept airfield heated pavement system (AHPS) prototype using near-surface embedded heat wire for pavement anti-icing is presented in this paper. Surface-embedded wires were used to study heat performance and energy warranted to maintain above-freezing slab surface temperatures. This approach concentrated heat energy to the pavement surface. Testing this AHPS prototype contained the following objectives: (1) optimise surface-embedded heat wire configuration, (2) investigate surface temperature distribution and (3) summarise system heating performance in outdoor winter conditions. Preliminary laboratory testing used a 150 mm wire spacing in a serpentine configuration. At this spacing, an energy flux of 142 W/m
2
produced a 6°C temperature rise in 6 h in a −14°C freezer chest. Sufficient surface temperature rise was attained in preliminary field-testing during the 2015-2016 winter season using a 213.1-697.5-W/m
2
energy range. Using the presented AHPS prototype, a 25-mm layer of crushed ice melted within 1 h during an experimental ice test.
Full text
Available for:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Plastics are ubiquitous and essential to our society. Unfortunately, they contribute to environmental pollution due to their lack of degradation upon disposal. Here, we describe some model polymers ...that were used to demonstrate controlled degradation under environmental conditions (pH 7). The polymers were made from a 7 : 3 ratio of hydroquinone (
HQA
) and terephthalate (
TPhA
) alkyne derivatives with various amounts of polyethylene glycol (
PEGAz
) and acetal azides (
AAz
). Their structures were determined by
1
H NMR. The ratio of monomer units in the polymers was shown to be similar to the feed ratio. The polymers are amorphous with low glass transition temperatures (
T
g
). Furthermore, the polymer containing 1 : 1 ratio of PEG to acetal units was degraded in pH 5 and 7 buffer solutions over a 3 month period, whereas the polymer with only acetal group degraded at pH 5. Our results show that degradation can be controlled with different amounts of PEG and acetal groups.
Enhanced degradation of acetal-containing polymers in environmental conditions.
Accurate and user-friendly rapid point-of-care diagnostic tests (POCT) are needed to optimize treatment of Neisseria gonorrhoeae, especially in low-resource settings where syndromic management is the ...standard of care for sexually transmitted infections. This study aimed to assess the acceptability and usability of a novel lateral flow assay and portable reader for the point-of-care detection of N. gonorrhoeae infection (NG-LFA). This mixed-methods study was conducted as part of a diagnostic performance and usability evaluation of a prototype NG-LFA for detection of N. gonorrhoeae in symptomatic men and women at primary healthcare facilities in the Buffalo City Metro, South Africa. The Standardized System Usability Scale (SUS) was administered, and in-depth interviews were conducted among healthcare professionals (HCPs) and fieldworkers (FWs) at pre-implementation, initial use and 3- and 6-month study implementation to assess user expectations, practical experience, and future implementation considerations for the NG-LFA. Data collection and analysis was guided by the Health Technology Adoption Framework, including new health technology attributes, learnability, satisfaction, and suitability. The framework was adapted to include perceived durability. A total of 21 HCPs and FWs were trained on the NG-LFA use. SUS scores showed good to excellent acceptability ranging from 78.8-90.6 mean scores between HCPs and FWs across study time points. All transcripts were coded using Dedoose and qualitative findings were organized by learnability, satisfaction, suitability, and durability domains. Usability themes are described for each time point. Initial insecurity dissipated and specimen processing dexterity with novel POCT technology was perfected over time especially amongst FWs through practical learning and easy-to-use instructions (learnability). Participants experienced both positive and negative test results, yielding perceived accuracy and minimal testing challenges overall (satisfaction). By 3- and 6-month use, both HCPs and FWs found the NG-LFA convenient to use in primary health care facilities often faced with space constraints and outlined perceived benefits for patients (suitability and durability). Findings show that the NG-LFA device is acceptable and usable even amongst paraprofessionals. High SUS scores and qualitative findings demonstrate high learnability, ease-of-use and suitability that provide valuable information for first-step scale-up requirements at primary healthcare level. Minor prototype adjustments would enhance robustness and durability aspects.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Organ hypertrophy can result from enlargement of individual cells or from cell proliferation or both. Activating mutations in the serine-threonine kinase Raf cause cardiac hypertrophy and contribute ...to Noonan syndrome in humans. Cardiac-specific expression of activated Raf also causes hypertrophy in Drosophila melanogaster. We found that Yorkie (Yki), a transcriptional coactivator in the Hippo pathway that regulates organ size, is required for Raf-induced cardiac hypertrophy in flies. Although aberrant activation of Yki orthologs stimulates cardiac hyperplasia in mice, cardiac-specific expression of an activated mutant form of Yki in fruit flies caused cardiac hypertrophy without hyperplasia. Knockdown of Yki caused cardiac dilation without loss of cardiomyocytes and prevented Raf-induced cardiac hypertrophy. In flies, Yki-induced cardiac hypertrophy required the TEA domain-containing transcription factor Scalloped, and, in mammalian cells, expression of mouse Raf(L613V), an activated form of Raf with a Noonan syndrome mutation, increased Yki-induced Scalloped activity. Furthermore, overexpression of Tgi (a Tondu domain-containing Scalloped-binding corepressor) in the fly heart abrogated Yki- or Raf-induced cardiac hypertrophy. Thus, crosstalk between Raf and Yki occurs in the heart and can influence Raf-mediated cardiac hypertrophy.
We analyzed data from a cohort of Black and Latino men who have sex with men (MSM) in order to identify correlates of prevalent and incident incarceration, including potential predictors related to ...their status as sexual and gender minorities (SGMs). Baseline and follow-up self-administered survey data were examined from Los Angeles County participants' ages 18-45 years at enrollment who were either HIV negative or living with HIV, but recruited to over represent men who used drugs and men with unsuppressed HIV infection. Multivariable logistic regression models were developed to identify predictors of baseline incarceration history and of incident incarceration over study follow-up among 440 and 338 participants, respectively. Older age, Black race, low socioeconomic status, homelessness, stimulant use, and depression symptoms were associated with baseline incarceration history. The only SGM-related factor associated with baseline incarceration history was having experienced violence based on sexual orientation identity. Just one statistically significant, independent positive predictor of incident incarceration was identified: prior incarceration, whereas having four or more friends that could lend money was a statistically significant protective factor against incident incarceration. Fundamental Cause Theory provides a useful framework to explain identified predictors of incarceration. Addressing poverty, housing instability, inadequate access to health care, and their root causes is critical to reducing incarceration rates in this population, as is expanded access to both diversion and anti-recidivism programs and to evidence-based treatment for stimulant use disorders.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This paper uses GARCH models and daily data to investigate the effect of the Canada – U.S. Free Trade Agreement (CUSFTA) and NAFTA on the volatility of, and the relationship between stock market ...returns and changes in bilateral exchange rates of the member countries. Empirical results indicate that the CUSFTA had a stabilizing effect on the Canadian and U.S. equity markets while increasing the volatility of the CAD/USD exchange rate. NAFTA further reduced the two stock markets’ volatility, however unlike CUSFTA, NAFTA also reduced the volatility of the CAD/USD exchange rate. Additional results indicate that during NAFTA, the Mexican stock market is more volatile than the other stock and bilateral exchange markets. Moreover, the exchange rate of the Mexican peso against both the U.S. and Canadian dollars has been more volatile than the Canadian dollar/US dollar exchange rate. Evidence also suggests that all three stock markets are positively correlated with each other with the U.S. market being much less correlated with the Canadian and Mexican stock markets than the latter two markets are correlated with each other. Evidence found in this paper suggests a negative relationship between the stock and bilateral currency markets that is statistically significant except for the U.S. equity market when paired with an exchange rate that involves the Mexican peso.
South Los Angeles (SPA6), with mostly Black (27.4%) and Latinx (68.2%) residents, has the second highest rates of new HIV diagnoses (31 per 100,000) in Los Angeles County. However, there is limited ...understanding of the HIV testing-to-care continuum among newly diagnosed in this setting. We conducted an exploratory study that analyzed de-identified data, including demographic characteristics and biomedical outcomes, from the electronic medical records of individuals newly diagnosed with HIV from 2016-2020 at the only public safety-net, county-run health department HIV clinic in SPA 6. We used Pearson Chi-square and Fisher's Exact test to explore associations with HIV outcomes and a Kaplan-Meier survival curve to assess the time to linkage to care. A total of 281 patients were identified. The majority (74.1%) presented with a baseline CD4 <500, many of which presented with a CD4<200 (39.2%). We found twice as many newly diagnosed Black individuals in our study population (48.2%) when compared to LAC (23%), despite only accounting for 27.4% of residents in SPA 6. The majority were linked to care within 30 days of positive test and prescribed anti-retroviral therapy. Viral suppression (59.8%) and undetectable VL (52.6%) were achieved within the year following diagnosis, with 9.3% lost to follow-up. Of those who became virally suppressed, 20.7% experienced viral rebound within the year following diagnosis. The large proportion of patients with a baseline CD4 <500 raises concerns about late diagnoses. Despite high rates of linkage to care and ART prescription, achievement of sustained viral suppression remains low with high rates of viral rebound. Longitudinal studies are needed to understand the barriers to early testing, retention in care, and treatment adherence to develop strategies and interventions with community organizations that respond to the unique needs of people living with HIV in South Los Angeles.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
