Surface Circulation and Horizontal Diffusion Processes of the Lower Chesapeake Bay

A Lagrangian method utilizing clusters of four or five buoyed drogues is used to study the surface circulation and horizontal diffusion processes of the lower Chesapeake Bay. The study area encompasses some 160 km2 and includes the area north of Thimble Shoal Channel, southwest of Chesapeake Channel and west of the Chesapeake Bay Bridge and Tunnel. Eleven trials utilizing buoyed drogues were conducted in the time frame February to October, 1979. Four trials were interrupted when buoys entered neighboring channels or dispersed too far for tracking, so that a total of sixteen runs were completed on the eleven trial dates. The runs averaged five hours from drifter drop to recover, with the longest run nine hours. Eulerian surface current and speed data were taken at one at-anchor station over a tidal period of twelve and one-half hours. The surface current, with local wind effect removed, is seen to be rotary, with the direction of rotation clockwise, and tidally dominated. It does not appear to be significantly influenced by, nor an influence on, the bordering channels with their dominant tidally reversing currents. A rotary current is not inconsistent with a tidally dominated wide estuary where Coriolis can be significant. The possibility of Kelvin and Poincare type wave motion is considered. The horizontal diffusivity, as represented by Richardson\u27s neighbor diffusivity concept, appears to confirm the applicability of the 4/3 power law to the study area. The energy dissipation rate is consistent with the results of other investigators. A need is recognized for a comprehensive Lagrangian-Eulerian diffusion/circulation field program that would permit simultaneous measurements of dye diffusion, drogue dispersion, currents, and tidal heights

The behaviour of polymer quenchants

The internationally accepted Wolfson Heat Treatment Centre Engineering Group test was used to evaluate the cooling characteristics of the most popular commercial polymer quenchants: polyalkylene glycols, polyvinylpyrrolidones and polyacrylates. Prototype solutions containing poly(ethyloxazoline) were also examined. Each class of polymer was capable of providing a wide range of cooling rates depending on the product formulation, concentration, temperature, agitation, ageing and contamination. Cooling rates for synthetic quenchants were generally intermediate between those of water and oil. Control techniques, drag-out losses and response to quenching in terms of hardness and residual stress for a plain carbon steel, were also considered. A laboratory scale method for providing a controllable level of forced convection was developed. Test reproducibility was improved by positioning the preheated Wolfson probe 25mm above the geometric centre of a 25mm diameter orifice through which the quenchant was pumped at a velocity of 0.5m/s. On examination, all polymer quenchants were found to operate by the same fundamental mechanism associated with their viscosity and ability to form an insulating polymer-rich-film. The nature of this film, which formed at the vapour/liquid interface during boiling, was dependent on the polymer's solubility characteristics. High molecular weight polymers and high concentration solutions produced thicker, more stable insulating films. Agitation produced thinner more uniform films. Higher molecular weight polymers were more susceptible to degradation, and increased cooling rates, with usage. Polyvinylpyrrolidones can be cross-linked resulting in erratic performance, whilst the anionic character of polyacrylates can lead to control problems. Volatile contaminants tend to decrease the rate of cooling and salts to increase it. Drag-out increases upon raising the molecular weight of the polymer and its solution viscosity. Kinematic viscosity measurements are more effective than refractometer readings for concentration control, although a quench test is the most satisfactory process control method

Pregnancy, prison and perinatal outcomes in New South Wales, Australia: a retrospective cohort study using linked health data

BACKGROUND Studies from the United States and the United Kingdom have found that imprisoned women are less likely to experience poorer maternal and perinatal outcomes than other disadvantaged women. This population-based study used both community controls and women with a history of incarceration as a control group, to investigate whether imprisoned pregnant women in New South Wales, Australia, have improved maternal and perinatal outcomes. METHODS Retrospective cohort study using probabilistic record linkage of routinely collected data from health and corrective services in New South Wales, Australia. Comparison of the maternal and perinatal outcomes of imprisoned pregnant women aged 18-44 years who gave birth between 2000-2006 with women who were (i) imprisoned at a time other than pregnancy, and (ii) community controls. OUTCOMES OF INTEREST onset of labour, method of birth, pre-term birth, low birthweight, Apgar score, resuscitation, neonatal hospital admission, perinatal death. RESULTS Babies born to women who were imprisoned during pregnancy were significantly more likely to be born pre-term, have low birthweight, and be admitted to hospital, compared with community controls. Pregnant prisoners did not have significantly better outcomes than other similarly disadvantaged women (those with a history of imprisonment who were not imprisoned during pregnancy). CONCLUSIONS In contrast to the published literature, we found no evidence that contact with prison health services during pregnancy was a "therapunitive" intervention. We found no association between imprisonment during pregnancy and improved perinatal outcomes for imprisoned women or their neonates. A history of imprisonment remained the strongest predictor of poor perinatal outcomes, reflecting the relative health disadvantage experienced by this population of women.This work was undertaken with funding from the National Health and Medical Research Council of Australia. Project Grant ID 457515

Expatriate Employees’ Perception Of Challenges In Their Work Environment In The Ngo Sector In Nairobi Kenya

This study examined how expatriate employees perceive the challenges in their work environment in the NGO sector in Nairobi, Kenya. The study question was “how do expatriate employees’ workings in the NGOs sector in Kenya perceive the challenges in their work environment?” The study was anchored on person-environment fit theory and the culture shock theory of adaptation to explain the strategies employed by expatriate employees to cope with challenges in their work environment. The research design used was a descriptive survey with a target population of 2394 NGOs based in Nairobi, Kenya. The study sample consisted of 120 expatriates, although only 84 participated in the final study drawn from 60 NGOs. Questionnaires were used to collect the data. Data was analyzed using SPSS. The result showed that expatriate employees working in the Kenyan NGOs respond to challenges in their work environment by finding a fit between the Kenyan culture and that of their countries. However, sometimes there is a big clash between the two cultures which makes it difficult for the expatriates to adjust well. Some have devised some strategies to interact with the locals that have improved their communication skills and ability to work on the assignments. In cases where conversing in the local languages has been a challenge, the expatriates have sought the help of locals as interpreters. Some expatriates accompanied by their families to provide psychological support. The study therefore recommends that since the expatriate employees seem to have integrated well into the Kenya society, they can be a great source of strength to those who are taking up new assignments in this country -Kenya. The future studies could focus on how the extent of expatriate employees ‘adjustment to the conditions in the host country affects their performance. In addition, they are a source of transmission of management ‘know-how’. This makes them a strong pillar as the local employees rely on their explicit knowledge and tacit knowledge to manage the NGOs even after their repatriation

Synthetic cation-selective nanotube: Permeant cations chaperoned by anions

The ability to design ion-selective, synthetic nanotubes which mimic biological ion channels may have significant implications for the future treatment of bacteria, diseases, and as ultrasensitive biosensors. We present the design of a synthetic nanotube made from carbon atoms that selectively allows monovalent cations to move across and rejects all anions. The cation-selective nanotube mimics some of the salient properties of biological ion channels. Before practical nanodevices are successfully fabricated it is vital that proof-of-concept computational studies are performed. With this in mind we use molecular and stochastic dynamics simulations to characterize the dynamics of ion permeation across a single-walled (10, 10), 36 Å long, carbon nanotube terminated with carboxylic acid with an effective radius of 5.08 Å. Although cations encounter a high energy barrier of 7 kT, its height is drastically reduced by a chloride ion in the nanotube. The presence of a chloride ion near the pore entrance thus enables a cation to enter the pore and, once in the pore, it is chaperoned by the resident counterion across the narrow pore. The moment the chaperoned cation transits the pore, the counterion moves back to the entrance to ferry another ion. The synthetic nanotube has a high sodium conductance of 124 pS and shows linear current-voltage and current-concentration profiles. The cation-anion selectivity ratio ranges from 8 to 25, depending on the ionic concentrations in the reservoirs.We acknowledge the support from the National Health and Medical Research Council and the MAWA Trust

Adverse perinatal outcomes in immigrants: A ten-year population-based observational study and assessment of growth charts

Background: Maternity populations are becoming increasingly multiethnic. Conflicting findings exist regarding the risk of adverse perinatal outcomes among immigrant mothers from different world regions and which growth charts are most appropriate for identifying the risk of adverse outcomes. Objective: To evaluate whether infant mortality and morbidity, and the categorisation of infants as small for gestational age or large for gestational age (SGA or LGA) vary by maternal country of birth, and to assess whether the choice of growth chart alters the risk of adverse outcomes in infants categorised as SGA and LGA. Methods: A population cohort of 601 299 singleton infants born in Australia to immigrant mothers was compared with 1.7 million infants born to Australian-born mothers, 2004-2013. Infants were categorised as SGA and LGA according to a descriptive Australian population-based birthweight chart (Australia-2012 reference) and the prescriptive INTERGROWTH-21st growth standard. Propensity score reweighting was used for the analysis. Results: Compared to Australian-born infants, infants of mothers from Africa, Philippines, India, other Asia countries, and the Middle East had between 15.4% and 48.1% elevated risk for stillbirth, preterm delivery, or low Apgar score. The association between SGA and LGA and perinatal mortality varied markedly by growth chart and country of birth. Notably, SGA infants from African-born mothers had a relative risk of perinatal mortality of 6.1 (95% CI 4.3, 6.7) and 17.3 (95% CI 12.0, 25.0) by the descriptive and prescriptive charts, respectively. LGA infants born to Australian-born mothers were associated with a 10% elevated risk of perinatal mortality by the descriptive chart compared to a 15% risk reduction by the prescriptive chart. Conclusions: Country-of-birth-specific variations are becoming increasingly important for providing ethnically appropriate and safe maternity care. Our findings highlight significant variations in risk of adverse perinatal outcomes in immigrant subgroups, and demonstrate how the choice of growth chart alters the quantification of risk associated with being born SGA or LGA

Outcomes of a funding initiative to promote allied health research activity: a qualitative realist evaluation

Providing funding for clinicians to have protected time to undertake research can address a commonly cited barrier to research - lack of time. However, limited research has evaluated the impact or mechanisms of such funding initiatives. In the current economic environment, it is important that funding is used efficiently and judiciously and that mechanisms and contexts that may assist with maximising outcomes of funding initiatives are identified. This study aimed to describe the medium-term outcomes of a funding initiative to promote allied health research activity and to identify the key mechanisms and contexts that facilitated these outcomes.We used a qualitative research design informed by a realist evaluation, to conduct 10 semi-structured interviews with allied health professionals who had participated in a funding initiative 1-3 years ago. Questions explored outcomes, mechanisms and contexts of the funding initiative. Data was thematically coded into context-mechanism-outcome configurations.Medium term outcomes included increased individual research opportunities, influence on team research culture and impact on clinical work/practice. Other outcomes included increased clinician confidence, knowledge and skill, and research outputs. However, some participants still had difficulties progressing research. Four context-mechanism-outcome configurations were identified to explain which contexts and mechanisms produced these outcomes. Examples of contexts included perception of managerial support, undertaking a research-based higher degree and joint applications, while mechanisms included accessing infrastructure and resources as well as individual researcher factors like motivation.Providing funding to allied health professionals to undertake and complete research can lead to important outcomes, including increased research opportunities, capacity and culture, increased research outputs, and changes to clinical practice. Outcomes are influenced by unique contexts and mechanisms and these should be considered in future implementation of similar funding initiatives

Child Health Information in the South East Region

Aims and objectives This project was commissioned by the South East Public Health Observatory to review and map the sources of information available about children and the child health data that are available from routine systems the South East Region. The project had two main components: 1. A review of data collected routine about children, including both local data available from national systems and data collected in local systems. 2. A two-part questionnaire survey to ascertain what data were held locally. The first part sought to identify the people within each PCT in the South East Region who were responsible for specific aspects of children’s services. The second part was to send a questionnaire to the people who were identified, to enquire about the local data they held or used. Results Routinely collected data A number of routine data systems containing data about children were identified and several more were under development. In many cases data from them were not routinely published. Others published data but did not disaggregate the below regional level. The National Congenital Anomaly System publishes data for strategic health authorities, data about children with special education needs are published for local education authorities, and data about maternity care are published by NHS trust. Birth and death registration data are available as individual records and tabulations for primary care trusts for use within the NHS only, although less detailed data are available for electoral wards and local authorities