An Assessment of Roadside Memorial Policy and Road Safety

When a loved one is lost in a crash, mourners often place roadside memorials to help with their grieving process but the placing of memorials has raised many questions about the impact the memorials themselves have on road safety. The two main views are that memorials either reduce road safety by distracting drivers or improve road safety by warning other drivers to proceed carefully. This paper collected and examined data relating to the effects of roadside memorials to allow for better informed policy to improve road safety. Responses to the driver questionnaire revealed that the majority of drivers preferred an "informal allow" policy. Even those strongly opposed to memorial use acknowledged the importance of the memorials for the grieving process. Responses from agencies surveyed indicated that road agencies in Alberta generally do not have a policy. This is largely attributed to the sensitive nature of the subject and the political issues

Effect of Different Median Barriers on Traffic Speed

This study assesses the impact of the types of median barriers installed on the comfort speed of drivers traveling in the median lane. Current guidelines and practices in most jurisdictions across the world assume that the types of barriers used do not have any impact on drivers' choice of speed. However, anecdotal evidence suggests that different drivers react differently to the presence of different types of median barriers due to differences in risk perceptions. If drivers do adapt their behaviors according to the types of barriers installed, then this relationship should be explicitly considered in the selection criteria. A speed study was therefore undertaken at selected sites with different median barriers such as ditch, curb, w-beam, thrie-beam, F-barrier, and F-barrier with chain-link fence. Also, sites were selected in both 70km/h and 80km/h posted speed zones to determine if effects would be consistent across different speeds. By comparing the mean speeds obtained at the barrier sites to those at non barrier sites, consistent differences in comfort speed were found for both speed zones considered. Discussion of implication to road safety and capacity is discussed and some recommendations on future barrier selection are provided

General practice consultation patterns by teenagers and their associations with health risks, needs and attitudes

During the transition from childhood to adulthood young people are vulnerable to relatively unique health problems and risks, whilst also developing personal autonomy, and learning when and how to access health services. This thesis describes three studies, the overall aim of which was to gain a greater understanding of how teenagers use general practice, and to identify those factors that influence this behaviour and ultimate health outcomes. The aim of the first two studies was to identify demographic, health, and attitudinal factors associated with both overall general practice consultation rates and consultation for specific types of condition. The first study involved identifying annual consultation rates and reasons for consultation from the medical records of 836 (94.4%) of 886 teenagers aged 13 to 15 registered with five general practices across the East Midlands, covering the 12 month period prior to the second study. In the second study, 713 (80.5%) of the 886 teenagers from the first study responded to a postal questionnaire survey, carried out between May and August 1997, which explored health concerns, help-seeking behaviour, health related behaviour, use of health services, and attitudes to general practice. The results from each of the first two studies were linked, in order to identify associations between self-reported health status, attitudes and behaviour and recorded consultation behaviour, based on the 678 teenagers for whom complete data sets were available. The median annual consultation rate was two, with 76.1% of teenagers consulting at least once and 23.8% consulting on four or more occasions. Consultation rates increased with age amongst girls, who had significantly higher rates than boys by age 15. Most consultations were for respiratory and skin problems, with consultations for psychological problems being least frequent. Teenagers reported a wide range of health concerns and, whilst general practitioners were identified as the most frequent source of health advice from formal health services, friends and family were cited far more frequently. Although 91.8% of survey respondents rated confidentiality as important, there was no association between attitudes towards confidentiality and actual consultation behaviour. In contrast, teenage girls who expressed concerns about embarrassment were less likely to consult about gynaecological problems and contraception. The third study was a case control study in which the general practice consultation patterns of 240 young women who subsequently became pregnant (having a recorded termination, delivery or miscarriage between January 1995 and January 1998) were compared with those of 719 age-matched controls without a history of pregnancy. Cases were significantly more likely than controls to have consulted in the year prior to conception with 93% of cases consulting at least once and 71% having discussed contraception at some time. Teenagers whose pregnancy ended in a termination were significantly more likely than controls to have received emergency contraception. In conclusion, whilst teenagers have been shown to use general practice for a range of health problems, the results from these studies suggest that there is a need to facilitate access for teenagers with more sensitive problems, and to improve identification and follow-up of those at greatest risk of adverse outcomes

The dynamics of weather-band sea level variations in the Red Sea

© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Regional Studies in Marine Science 24 (2018): 336-342, doi:10.1016/j.rsma.2018.09.006.The variations of sea level over the Red Sea may be divided into three broad categories: tidal, seasonal and weather-band. Our study employs a variety of in situ and satellite-derived data in the first comprehensive examination of the Red Sea water level variations in the weather-band (covering periods of 4–30 days). In the central Red Sea, the range of the weather-band sea level signal is of order 0.7 m, which exceeds the tidal and seasonal sea level ranges. From EOF and correlation analysis, we find that a large fraction of the weather-band sea level variation is due to a single mode of motion that extends over the entire Red Sea. In this mode, the water level rises and falls in unison with an amplitude that declines going southward over the southern Red Sea. The temporal signal of this mode is highly correlated with the along-axis surface wind stress over the southern Red Sea, and is closely reproduced by a simple one-dimensional barotropic model with forcing by the along-axis wind stress. Although this model does not account for the full suite of dynamics affecting weather-band sea level variations in the Red Sea, it may serve as a useful predictive tool. Sea level changes associated with the development and movement of sub-mesoscale features (e.g., eddies and boundary currents) are also shown to contribute to weather-band sea level motions in the Red Sea.The pressure sensor and meteorological buoy data were acquired as part of a program supported by Award Nos. USA00001, USA00002 and KSA00011 made by KAUST to WHOI. The data analysis and modeling work of this study were supported General Commission for Survey (GCS), under a project number RGC/3/1612-01-01 made by Office of Sponsored research (ORS)/KAUST, Kingdom of Saudi Arabia

General practice consultation patterns by teenagers and their associations with health risks, needs and attitudes

During the transition from childhood to adulthood young people are vulnerable to relatively unique health problems and risks, whilst also developing personal autonomy, and learning when and how to access health services. This thesis describes three studies, the overall aim of which was to gain a greater understanding of how teenagers use general practice, and to identify those factors that influence this behaviour and ultimate health outcomes. The aim of the first two studies was to identify demographic, health, and attitudinal factors associated with both overall general practice consultation rates and consultation for specific types of condition. The first study involved identifying annual consultation rates and reasons for consultation from the medical records of 836 (94.4%) of 886 teenagers aged 13 to 15 registered with five general practices across the East Midlands, covering the 12 month period prior to the second study. In the second study, 713 (80.5%) of the 886 teenagers from the first study responded to a postal questionnaire survey, carried out between May and August 1997, which explored health concerns, help-seeking behaviour, health related behaviour, use of health services, and attitudes to general practice. The results from each of the first two studies were linked, in order to identify associations between self-reported health status, attitudes and behaviour and recorded consultation behaviour, based on the 678 teenagers for whom complete data sets were available. The median annual consultation rate was two, with 76.1% of teenagers consulting at least once and 23.8% consulting on four or more occasions. Consultation rates increased with age amongst girls, who had significantly higher rates than boys by age 15. Most consultations were for respiratory and skin problems, with consultations for psychological problems being least frequent. Teenagers reported a wide range of health concerns and, whilst general practitioners were identified as the most frequent source of health advice from formal health services, friends and family were cited far more frequently. Although 91.8% of survey respondents rated confidentiality as important, there was no association between attitudes towards confidentiality and actual consultation behaviour. In contrast, teenage girls who expressed concerns about embarrassment were less likely to consult about gynaecological problems and contraception. The third study was a case control study in which the general practice consultation patterns of 240 young women who subsequently became pregnant (having a recorded termination, delivery or miscarriage between January 1995 and January 1998) were compared with those of 719 age-matched controls without a history of pregnancy. Cases were significantly more likely than controls to have consulted in the year prior to conception with 93% of cases consulting at least once and 71% having discussed contraception at some time. Teenagers whose pregnancy ended in a termination were significantly more likely than controls to have received emergency contraception. In conclusion, whilst teenagers have been shown to use general practice for a range of health problems, the results from these studies suggest that there is a need to facilitate access for teenagers with more sensitive problems, and to improve identification and follow-up of those at greatest risk of adverse outcomes

Modified Mclaren-marsaglia Pseudo-random Number Generator and Stochastic Key Agreement

A discussion of problems in cryptographic applications, with a brief survey of pseudo-random number generators (PRNG) used as synchronous stream ciphers, leads to a discussion of the McClaren-Marsaglia shuffling PRNG, and some means of altering its structure to both provide a more secure PRNG and to provide effective means by which to inject aperiodicity into a modified form of McClaren-Marsaglia. A discussion of two closely related protocols using this modified form of McClaren-Marsaglia as means by which correspondents may agree upon a set of random bits in a manner suitable for use in cryptographic applications is then presented, with implementation in the C programming language of the second protocol. Analysis of the protocols concludes that a reasonable expectation of confidentiality and cryptographic strength in the agreed bit-sequence is obtained.Computer Science Departmen

Metabolomic profiles are gender, disease and time specific in the interleukin-10 gene-deficient mouse model of inflammatory bowel disease.

Metabolomic profiling can be used to study disease-induced changes in inflammatory bowel diseases (IBD). The aim of this study was to investigate the difference in the metabolomic profile of males and females as they developed IBD. Using the IL-10 gene-deficient mouse model of IBD and wild-type mice, urine at age 4, 6, 8, 12, 16, and 20 weeks was collected and analyzed by nuclear magnetic resonance (NMR) spectroscopy. Multivariate data analysis was employed to assess differences in metabolomic profiles that occurred as a consequence of IBD development and severity (at week 20). These changes were contrasted to those that occurred as a consequence of gender. Our results demonstrate that both IL-10 gene-deficient and wild-type mice exhibit gender-related changes in urinary metabolomic profile over time. Some male-female separating metabolites are common to both IL-10 gene-deficient and control wild-type mice and, therefore, appear to be related predominantly to gender maturation. In addition, we were able to identify gender-separating metabolites that are unique for IL-10 gene-deficient and wild-type mice and, therefore, may be indicative of a gender-specific involvement in the development and severity of the intestinal inflammation. The comparison of the gender-separating metabolomic profile from IL-10 gene-deficient mice and wild-type mice during the development of IBD allowed us to identify changes in profile patterns that appear to be imperative in the development of intestinal inflammation, but yet central to gender-related differences in IBD development. The knowledge of metabolomic profile differences by gender and by disease severity has potential clinical implications in the design of both biomarkers of disease as well as the development of optimal therapies

Examination of optimizing information flow in networks

The central role of the Internet and the World-Wide-Web in global communications has refocused much attention on problems involving optimizing information flow through networks. The most basic formulation of the question is called the "max flow" optimization problem: given a set of channels with prescribed capacities that connect a set of nodes in a network, how should the materials or information be distributed among the various routes to maximize the total flow rate from the source to the destination. Theory in linear programming has been well developed to solve the classic max flow problem. Modern contexts have demanded the examination of more complicated variations of the max flow problem to take new factors or constraints into consideration; these changes lead to more difficult problems where linear programming is insufficient. In the workshop we examined models for information flow on networks that considered trade-offs between the overall network utility (or flow rate) and path diversity to ensure balanced usage of all parts of the network (and to ensure stability and robustness against local disruptions in parts of the network). While the linear programming solution of the basic max flow problem cannot handle the current problem, the approaches primal/dual formulation for describing the constrained optimization problem can be applied to the current generation of problems, called network utility maximization (NUM) problems. In particular, primal/dual formulations have been used extensively in studies of such networks. A key feature of the traffic-routing model we are considering is its formulation as an economic system, governed by principles of supply and demand. Considering channel capacities as a commodity of limited supply, we might suspect that a system that regulates traffic via a pricing scheme would assign prices to channels in a manner inversely proportional to their respective capacities. Once an appropriate network optimization problem has been formulated, it remains to solve the optimization problem; this will need to be done numerically, but the process can greatly benefit from simplifications and reductions that follow from analysis of the problem. Ideally the form of the numerical solution scheme can give insight on the design of a distributed algorithm for a Transmission Control Protocol (TCP) that can be directly implemented on the network. At the workshop we considered the optimization problems for two small prototype network topologies: the two-link network and the diamond network. These examples are small enough to be tractable during the workshop, but retain some of the key features relevant to larger networks (competing routes with different capacities from the source to the destination, and routes with overlapping channels, respectively). We have studied a gradient descent method for solving obtaining the optimal solution via the dual problem. The numerical method was implemented in MATLAB and further analysis of the dual problem and properties of the gradient method were carried out. Another thrust of the group's work was in direct simulations of information flow in these small networks via Monte Carlo simulations as a means of directly testing the efficiencies of various allocation strategies