Globally, little evidence exists on transmission patterns of COVID-19. Recommendations to prevent infection include appropriate and frequent handwashing plus physical and social distancing. We ...conducted an exploratory observational study to assess compliance with these recommendations in selected transportation stations in Ghana. A one-hour audit of 45 public transport stations in the Greater Accra region was carried out between 27th and 29th March 2020. Using an adapted World Health Organization (WHO) hand hygiene assessment scale, the availability and use of handwashing facilities, social distancing, and ongoing public education on COVID-19 prevention measures were assessed, weighted and scored to determine the level of compliance of stations. Compliance with recommendations was categorized as "inadequate" "basic", "intermediate" and "advanced", based on the overall score. Majority (80%) of stations in Accra have at least one Veronica Bucket with flowing water and soap, but the number of washing places at each station is not adequate. Only a small minority (18%) of stations were communicating the need to wash hands frequently and appropriately, and to practice social/physical distancing while at the station. In most stations (95%), hand washing practice was either not observed, or only infrequently. Almost all stations (93%) did not have alcohol-based hand sanitizers available for public use, while social distancing was rarely practiced (only 2%). In over 90% of the stations, face masks were either not worn or only worn by a few passengers. Compliance with COVID-19 prevention measures was inadequate in 13 stations, basic in 16 stations, intermediate in 7 stations, and advanced in 9 stations. Compliance with COVID-19 prevention measures in public transportation stations in the Greater Accra region remains a challenge. Awareness creation should aim to elevate COVID-19 risk perception of transportation operators and clients. Transport operators and stations need support and guidance to enforce hand washing and social distancing.
In the past decade, semiconducting carbon nanotube thin films have been recognized as contending materials for wide-ranging applications in electronics, energy, and sensing. In particular, ...improvements in large-area flexible electronics have been achieved through independent advances in postgrowth processing to resolve metallic versus semiconducting carbon nanotube heterogeneity, in improved gate dielectrics, and in self-assembly processes. Moreover, controlled tuning of specific device components has afforded fundamental probes of the trade-offs between materials properties and device performance metrics. Nevertheless, carbon nanotube transistor performance suitable for real-world applications awaits understanding-based progress in the integration of independently pioneered device components. We achieve this here by integrating high-purity semiconducting carbon nanotube films with a custom-designed hybrid inorganic–organic gate dielectric. This synergistic combination of materials circumvents conventional design trade-offs, resulting in concurrent advances in several transistor performance metrics such as transconductance (6.5 μS/μm), intrinsic field-effect mobility (147 cm2/(V s)), subthreshold swing (150 mV/decade), and on/off ratio (5 × 105), while also achieving hysteresis-free operation in ambient conditions.
Reflecting on one's positionality as a researcher is a critical element in qualitative studies. While there are various qualitative studies on the meaning of and the way positionality affects ...qualitative research practice, this research note examines the phenomenon as it applies to the author's doctoral study. Drawing from a collection of research memoirs, the research note presents the author's conceptualisation of personal positionality in the study, based on nationality, personal values, work experience, age and gender. The note details the author's multiple identity shifts throughout the study. Potential challenges and opportunities of knowing one's positionality together with the effects of positionality on the participants, the researcher as well as the research process are highlighted. It concludes that positionality among qualitative researchers is characterised by fluidity, instability and continued shifts as opposed to it being a constant form of researcher identity.
While graphene has attracted significant attention from the research community due to its high charge carrier mobility, important issues remain unresolved that prevent its widespread use in ...technologically significant applications such as digital electronics. For example, the chemical inertness of graphene hinders integration with other materials, and the lack of a bandgap implies poor switching characteristics in transistors. The formation of ordered organic monolayers on graphene has the potential to address each of these challenges. In particular, functional groups incorporated into the constituent molecules enable tailored chemical reactivity, while molecular-scale ordering within the monolayer provides sub-2 nm templates with the potential to tune the electronic band structure of graphene via quantum confinement effects. Toward these ends, we report here the formation of well-defined one-dimensional organic nanostructures on epitaxial graphene via the self-assembly of 10,12-pentacosadiynoic acid (PCDA) in ultrahigh vacuum (UHV). Molecular resolution UHV scanning tunneling microscopy (STM) images confirm the one-dimensional ordering of the as-deposited PCDA monolayer and show domain boundaries with symmetry consistent with the underlying graphene lattice. In an effort to further stabilize the monolayer, in situ ultraviolet photopolymerization induces covalent bonding between neighboring PCDA molecules in a manner that maintains one-dimensional ordering as verified by UHV STM and ambient atomic force microscopy (AFM). Further quantitative insights into these experimental observations are provided by semiempirical quantum chemistry calculations that compare the molecular structure before and after photopolymerization.
The development of high-performance graphene-based nanoelectronics requires the integration of ultrathin and pinhole-free high-k dielectric films with graphene at the wafer scale. Here, we ...demonstrate that self-assembled monolayers of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) act as effective organic seeding layers for atomic layer deposition (ALD) of HfO2 and Al2O3 on epitaxial graphene on SiC(0001). The PTCDA is deposited via sublimation in ultrahigh vacuum and shown to be highly ordered with low defect density by molecular-resolution scanning tunneling microscopy. Whereas identical ALD conditions lead to incomplete and rough dielectric deposition on bare graphene, the chemical functionality provided by the PTCDA seeding layer yields highly uniform and conformal films. The morphology and chemistry of the dielectric films are characterized by atomic force microscopy, ellipsometry, cross-sectional scanning electron microscopy, and X-ray photoelectron spectroscopy, while high-resolution X-ray reflectivity measurements indicate that the underlying graphene remains intact following ALD. Using the PTCDA seeding layer, metal-oxide-graphene capacitors fabricated with a 3 nm Al2O3 and 10 nm HfO2 dielectric stack show high capacitance values of ∼700 nF/cm2 and low leakage currents of ∼5 × 10–9 A/cm2 at 1 V applied bias. These results demonstrate the viability of sublimated organic self-assembled monolayers as seeding layers for high-k dielectric films in graphene-based nanoelectronics.
The full potential of graphene in integrated circuits can only be realized with a reliable ultrathin high-κ top-gate dielectric. Here, we report the first statistical analysis of the breakdown ...characteristics of dielectrics on graphene, which allows the simultaneous optimization of gate capacitance and the key parameters that describe large-area uniformity and dielectric strength. In particular, vertically heterogeneous and laterally homogeneous Al2O3 and HfO2 stacks grown via atomic-layer deposition and seeded by a molecularly thin perylene-3,4,9,10-tetracarboxylic dianhydride organic monolayer exhibit high uniformities (Weibull shape parameter β > 25) and large breakdown strengths (Weibull scale parameter, E BD > 7 MV/cm) that are comparable to control dielectrics grown on Si substrates.
•Eyewash stations are important safety equipment characterized by long water age.•Significant increases in microbial contamination were detected in eyewash stations.•Eyewash stations may serve as ...potential sources of pathogen exposure.•Proper eyewash flushing was effective in reducing microbial contamination.
Emergency eyewash stations are important safety equipment characterized by long water age. Significant increases in microbial contamination were detected in eyewash stations with water ages longer than 1 day. Enterobacter and Mycobacterium were identified in high abundance in eyewash stations with prolonged water age, suggesting eyewash stations as potential sources of pathogen exposure. Proper eyewash flushing was shown to be an effective practice to mitigate risks of exposure to microbial contaminants from eyewash use.
Zoos are required to maintain a high standard of animal welfare, and this can be assessed using a combination of resource-based and animal-based indices usually divided into behavioural indicators, ...physiological indicators and clinical/pathological signs. Modern animal welfare assessments should aim to encompass positive affective states and the indicators that are useful in assessing these are discussed. When developing factors to be scored for each species, there is huge variability in the available information about the natural biology for some zoo species and even less information concerning those animals in captivity. Wild baselines are not always the most accurate indicator of what is right for an animal in captivity, which makes the identification of factors to include within species-specific welfare assessment even more challenging. When planning a welfare strategy for any species, it is important that the full range of their biological requirements and needs are considered, but this can be challenging for some zoo species and it is not possible to define a "one size fits all" welfare strategy. The different approaches for welfare assessment are reviewed, including the development of the Animal Welfare Assessment Grid which offers an evidence-based tool for continual welfare assessment, using technology where appropriate, to facilitate decision making and lead to improvements in the animals' quality of life.
•In 2018, about 8,883,931 and 12,566,478 children aged under 5 years old in Nigeria had not received routine DTP1 and MCV1, respectively.•MCV and DTP zero-dose prevalence shared similar patterns, ...with highest prevalence districts concentrated in the northeast and northwest but also found elsewhere.•Measles incidence, though mitigated by campaigns, is related to subnational routine MCV1 coverage.•Residual zero-dose prevalence following vaccination campaigns should be analysed and reported.•Targeted campaigns or routine immunization interventions in higher zero-dose prevalence districts are needed to reduce disease risk.
Geographically precise identification and targeting of populations at risk of vaccine-preventable diseases has gained renewed attention within the global health community over the last few years. District level estimates of vaccination coverage and corresponding zero-dose prevalence constitute a potentially useful evidence base to evaluate the performance of vaccination strategies. These estimates are also valuable for identifying missed communities, hence enabling targeted interventions and better resource allocation. Here, we fit Bayesian geostatistical models to map the routine coverage of the first doses of diphtheria-tetanus-pertussis vaccine (DTP1) and measles-containing vaccine (MCV1) and corresponding zero-dose estimates in Nigeria at 1x1 km resolution and the district level using geospatial data sets. We also map MCV1 coverage before and after the 2019 measles vaccination campaign in the northern states to further explore variations in routine vaccine coverage and to evaluate the effectiveness of both routine immunization (RI) and campaigns in reaching zero-dose children. Additionally, we map the spatial distributions of reported measles cases during 2018 to 2020 and explore their relationships with MCV zero-dose prevalence to highlight the public health implications of varying performance of vaccination strategies across the country. Our analysis revealed strong similarities between the spatial distributions of DTP and MCV zero dose prevalence, with districts with the highest prevalence concentrated mostly in the northwest and the northeast, but also in other areas such as Lagos state and the Federal Capital Territory. Although the 2019 campaign reduced MCV zero-dose prevalence substantially in the north, pockets of vulnerabilities remained in areas that had among the highest prevalence prior to the campaign. Importantly, we found strong correlations between measles case counts and MCV RI zero-dose estimates, which provides a strong indication that measles incidence in the country is mostly affected by RI coverage. Our analyses reveal an urgent and highly significant need to strengthen the country’s RI program as a longer-term measure for disease control, whilst ensuring effective campaigns in the short term.
Objectives
The study examined the relations between parent–child interaction in the first year of life to toddlers’ language skills at age 2 years for a sample of children reared in poverty; of ...specific interest was testing the Family Stress Model, which proposes that the conditions of poverty influence children’s language skills through caregiver well-being (e.g., distress, depression) and interaction dysregulation.
Methods
Participants were from the Kids in Columbus Study, a birth-cohort study of children born to urban families experiencing material hardship. Caregiver questionnaires were collected when the child was 4–7 months to document poverty conditions (maternal hardship, institutional resources), caregiver well-being (depression, distress), and dysregulation in parent–child interactions. The Bayley-III assessed receptive and expressive language skills when the children were 2 years.
Results
On average, receptive language skills were nearly
1 SD
below the normative mean. Path models showed a significant effect of caregiver-child dysregulated interactions on toddlers’ language skills, and an indirect effect of maternal distress on parent–child interactions and, in turn, toddlers’ language skills.
Conclusions for Practice
This study confirmed the theoretical Family Stress Model as a viable representation of the effects of poverty on the language skills of toddlers reared in homes experiencing socioeconomic disadvantage.
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