To see the other types of publications on this topic, follow the link: Risk environments.
Dissertations / Theses on the topic 'Risk environments'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Risk environments.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Hoyes, Thomas W. "Risk homeostasis theory in simulated environments." Thesis, Aston University, 1992. http://publications.aston.ac.uk/10858/.
Full textAbstract:
This thesis has two aims. First, it sets out to develop an alternative methodology for the investigation of risk homeostasis theory (RHT). It is argued that the current methodologies of the pseudo-experimental design and post hoc analysis of road-traffic accident data both have their limitations, and that the newer 'game' type simulation exercises are also, but for different reasons, incapable of testing RHT predictions. The alternative methodology described here is based on the simulation of physical risk with intrinsic reward rather than a 'points pay-off'. The second aim of the thesis is to examine a number of predictions made by RHT through the use of this alternative methodology. Since the pseudo-experimental design and post hoc analysis of road-traffic data are both ill-suited to the investigation of that part of RHT which deals with the role of utility in determining risk-taking behaviour in response to a change in environmental risk, and since the concept of utility is critical to RHT, the methodology reported here is applied to the specific investigation of utility. Attention too is given to the question of which behavioural pathways carry the homeostasis effect, and whether those pathways are 'local' to the nature of the change in environmental risk. It is suggested that investigating RHT through this new methodology holds a number of advantages and should be developed further in an attempt to answer the RHT question. It is suggested too that the methodology allows RHT to be seen in a psychological context, rather than the statistical context that has so far characterised its investigation. The experimental findings reported here are in support of hypotheses derived from RHT and would therefore seem to argue for the importance of the individual and collective target level of risk, as opposed to the level of environmental risk, as the major determinant of accident loss.
2
Priya, Patil G. "Community contextual and environmental determinants of HIV risk in Rakai District, Uganda community risk-environments, individual seroconversion risk, and individual perception of risk /." Available to US Hopkins community, 2003. http://wwwlib.umi.com/dissertations/dlnow/3080742.
Full text
3
Zhang, Su. "Quantitative risk assessment under multi-context environments." Diss., Kansas State University, 2014. http://hdl.handle.net/2097/18634.
Full textAbstract:
Doctor of PhilosophyDepartment of Computing and Information Sciences
Xinming Ou
If you cannot measure it, you cannot improve it. Quantifying security with metrics is important not only because we want to have a scoring system to track our efforts in hardening cyber environments, but also because current labor resources cannot administrate the exponentially enlarged network without a feasible risk prioritization methodology. Unlike height, weight or temperature, risk from vulnerabilities is sophisticated to assess and the assessment is heavily context-dependent. Existing vulnerability assessment methodologies (e.g. CVSS scoring system, etc) mainly focus on the evaluation over intrinsic risk of individual vulnerabilities without taking their contexts into consideration. Vulnerability assessment over network usually output one aggregated metric indicating the security level of each host. However, none of these work captures the severity change of each individual vulnerabilities under different contexts. I have captured a number of such contexts for vulnerability assessment. For example, the correlation of vulnerabilities belonging to the same application should be considered while aggregating their risk scores. At system level, a vulnerability detected on a highly depended library code should be assigned with a higher risk metric than a vulnerability on a rarely used client side application, even when the two have the same intrinsic risk. Similarly at cloud environment, vulnerabilities with higher prevalences deserve more attention. Besides, zero-day vulnerabilities are largely utilized by attackers therefore should not be ignored while assessing the risks. Historical vulnerability information at application level can be used to predict underground risks. To assess vulnerability with a higher accuracy, feasibility, scalability and efficiency, I developed a systematic vulnerability assessment approach under each of these contexts.
4
Myer, Matthew R., and Jason R. Lojka. "On risk: risk and decision making in military combat and training environments." Thesis, Monterey, California. Naval Postgraduate School, 2012. http://hdl.handle.net/10945/27877.
Full textAbstract:
All decisions involve risk; yet the subject is poorly understood and difficult to define. Understanding risk is vital for military leaders that prepare their forces to operate in risky environments against adversaries that seek to impose risk upon their enemies. Furthermore, the decisions of military leaders affect those subordinates under their command and ultimately the will of the nation that has sent them abroad. It is paramount, therefore, that we utilize a decision process to reveal how emotions can affect our judgment. Frequently, cultural forces in the military can result in ill-informed and emotionally biased decisions that are an irresponsible execution of duty. We address this problem by defining the objective components of risk using mathematical concepts then characterizing the nature of risk in different military environments using those concepts. Our approach uses economic principles, game theory, and decision theory to illustrate how calculations of risk should influence decision-making. Objectively defining risk will aid in revealing the subjective components of risk, where the mathematical principles explain both how decisions are effectively made and how to make decisions effectively. Risk in training and risk in combat pose two very different problems; but to be fully understood both environments must be viewed together. This detailed analysis and research aims to create a more informed decision making process and a more sophisticated decision maker.
5
Wall, Tamara. "A content analysis : health and environmental risk factors of children in methamphetamine living environments /." Available to subscribers only, 2008. http://proquest.umi.com/pqdweb?did=1559858731&sid=1&Fmt=2&clientId=1509&RQT=309&VName=PQD.
Full text
6
Pennington, Neil. "Electrical safety in hazardous environments : ignition studies." Thesis, University of Liverpool, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292082.
Full text
7
Krokhmal, Pavlo A. "Risk management techniques for decision making in highly uncertain environments." [Gainesville, Fla.] : University of Florida, 2003. http://purl.fcla.edu/fcla/etd/UFE0001008.
Full text
8
Hoy, Jennifer Susan. "Employee behaviour in social media environments impacting corporate reputational risk." Diss., University of Pretoria, 2012. http://hdl.handle.net/2263/30604.
Full textAbstract:
An employee who has a low level of awareness of how behaviours impact corporate reputation, and access to large online communities, could potentially expose the business to reputational risk. The vast number of individuals on these networks, combined with the low level of skill needed to publish on these sites, has resulted in comments and behaviours being amplified to a much greater audience. Employees and their behaviours represent the reality of the organisation to external stakeholders, and so offer a potential risk for reputational damage.This research used an online survey with Likert scales to test the hypotheses. The survey was sent out to a convenience sample, and then a snowballing technique was used to reach the employees within the identified companies.Managers and employees are equally aware of their impact on corporate reputation; however, they have a difference in opinion on what are acceptable topics to place in the public domain. A breach in the employee-employer psychological contract does not result in an increase in employee‟s willingness to post sensitive information in the public domain and employees are undecided as to how they feel about being prohibited from posting certain information in the public domain as an infringement of their person rights.Dissertation (MBA)--University of Pretoria, 2012.
Gordon Institute of Business Science (GIBS)
unrestricted
9
Sayers, William Keith Paul. "Artificial intelligence techniques for flood risk management in urban environments." Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/21030.
Full textAbstract:
Flooding is an important concern for the UK, as evidenced by the many extreme flooding events in the last decade. Improved flood risk intervention strategies are therefore highly desirable. The application of hydroinformatics tools, and optimisation algorithms in particular, which could provide guidance towards improved intervention strategies, is hindered by the necessity of performing flood modelling in the process of evaluating solutions. Flood modelling is a computationally demanding task; reducing its impact upon the optimisation process would therefore be a significant achievement and of considerable benefit to this research area. In this thesis sophisticated multi-objective optimisation algorithms have been utilised in combination with cutting-edge flood-risk assessment models to identify least-cost and most-benefit flood risk interventions that can be made on a drainage network. Software analysis and optimisation has improved the flood risk model performance. Additionally, artificial neural networks used as feature detectors have been employed as part of a novel development of an optimisation algorithm. This has alleviated the computational time-demands caused by using extremely complex models. The results from testing indicate that the developed algorithm with feature detectors outperforms (given limited computational resources available) a base multi-objective genetic algorithm. It does so in terms of both dominated hypervolume and a modified convergence metric, at each iteration. This indicates both that a shorter run of the algorithm produces a more optimal result than a similar length run of a chosen base algorithm, and also that a full run to complete convergence takes fewer iterations (and therefore less time) with the new algorithm.
10
Määttä, Timo. "Virtual environments in machinery safety analysis /." Espoo [Finland] : VTT Technical Research Centre of Finland, 2003. http://www.vtt.fi/inf/pdf/publications/2003/P516.pdf.
Full textAbstract:
Diss. -- Tampereen teknillinen yliopisto. Thesis (doctoral)--Tampere University of Technology, 2004.Includes bibliographical references (p. 153-170). Myös verkkojulkaisuna. Also available on the World Wide Web.
11
Mills, Alice Rose. "The friendship patterns of adolescent girls from high-risk social environments." Thesis, King's College London (University of London), 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420090.
Full text
12
Fielding, Carolyn Anne Carleton University Dissertation Geography. "Wildlife rabies and urban expansion; environments of risk in Ottawa- Carleton." Ottawa, 1986.
Find full text
13
Maghrabi, Louai. "Novel game theoretic frameworks for security risk assessment in cloud environments." Thesis, Kingston University, 2017. http://eprints.kingston.ac.uk/41956/.
Full text
14
Jaramillo, Gutiérrez Ainhoa. "Gender differences in strategic and risky environments." Doctoral thesis, Universitat Jaume I, 2007. http://hdl.handle.net/10803/10362.
Full textAbstract:
We analyze experimental results obtained from the ultimatum game framed as a situation of salary negotiation. First, we frame ultimatum bargaining as a situation of salary negotiation. Second, we introduce a real task which has to be performed by employee-subjects as a consequence of accepting a given salary. We show that real effort raises salaries. In fact, this result is due to both higher salary offers by employers and higher rejection rates by employees. Besides, we study gender differences in individual decision making under uncertainty using the lottery panel test introduced in Sabater-Grande and Georgantzís (2002). Regarding risk aversion, our results confirm that female subjects are more risk averse than males. Regarding sensitivity to risk, female subjects are less attracted than men by the linear risk premia used in the design of the four panels.
Our evidence suggests that gender and risk-related effects in ultimatum bargaining can and should be disentangled as two separate idiosyncratic dimensions. Specifically, although we confirm the broadly accepted result that females are more risk averse than males, we find that offers made by females are lower than those posted by male subjects. In fact, the gender effect becomes stronger once risk attitudes are accounted for. Gender effects are found to depend also on cultural differences. In sessions with Greek and Spanish subjects we obtain gender differences of the same sign and similar sizes, whereas British females' behavior differs from that of males only in the case of employee subjects and in the opposite direction to the gender effect reported on subjects from the two Mediterranean countries.
15
Tous, Nadal Maria. "MEDICANES: meteorological environments and risk assessment in the present and future climate." Doctoral thesis, Universitat de les Illes Balears, 2015. http://hdl.handle.net/10803/364769.
Full textAbstract:
Medicanes are a rare and physically unique type of Mediterranean cyclone. They
show similarities with tropical cyclones with regard to their development (based on the
thermodynamical disequilibrium between the warm sea and the overlying troposphere)
and the kinematic and thermodynamical properties (medicanes are intense vortices with
a warm core and even a cloud-free-eye). Although medicanes are smaller and the
characteristic wind speeds are lower, the severity of the winds can cause substantial
damage on islands and coastal areas.
The special characteristics of medicanes make their detection di cult: only with high
resolution meteorological analyses and dense maritime observations that task would be
possible. For this reason, an alternative method using satellite images and restricted
criteria about the disturbance symmetry, size and lifespan, has been applied leading to
the detection of 12 medicanes from 1982 to 2003.
To improve the medicane forecast capability or even to assess the potential risk of these
storms in future climates, it is necessary to characterize the special conditions of the
synoptic-scale meteorological environments that are needed for their development and
maintenance. By comparing these environments against the bulk of intense Mediterranean
cyclonic situations, high values of mid-tropospheric relative humidity, signi cant diabatic
contribution to the surface level equivalent potential temperature tendency, and low values
of tropospheric wind shear, are revealed as important parameters involved in medicane
genesis, as in tropical cyclones. An empirical genesis index previously derived for the
tropical regions is also tested in this thesis, and it is revealed as a possible discriminative
parameter of the precursor environments.
Despite their small size, mesoscale runs of medicane situations at moderate horizontal
resolutions (7.5 km) made with MM5 are able to simulate the formation of a subsynoptic
cyclone and the general trajectory of the disturbance, and for most of the cases a
warm-core axi-symmetrical structure becomes evident in the simulations. In addition,
a sensitivity analysis examining the role of the sea surface heat uxes is conducted: latent
and sensible heat uxes from the Mediterranean are switched o during the simulations to explore the e ects of these factors on the medicane trajectories and deepening
rate. Results show di erent roles of the surface heat uxes on medicane properties
(intensi cation and track) depending on their magnitude and spatial distribution over
the Mediterranean Sea. In this way, three distinct evolution patterns have been identi ed
using the database of twelve events.
In the context of the growing concern about how climate change will a ect the number
and intensity of hurricanes, two di erent analysis for medicanes have been conducted
in this thesis: an oriented dynamical downscaling and a direct detection of storms in a
high-resolution global climate model. On one hand, the oriented dynamical downscaling
consists in projecting the previous empirical genesis index into four di erent global climate
models, with spatial resolutions about 200 km, and analyze (simulate) just the areas with
elevated medicane risk values. On the other hand, an independent study using a direct
detection and tracking of warm-core cyclones is applied to a high resolution global climate
model (spatial resolution about 25 km). Both methods predict a decreasing trend in
medicane occurrence, and indicate the south-east of Italy and the Gulf of Lion as the
areas with higher probability of medicane development in future scenarios. With regard
to future changes in medicane intensity, there seems to be signs of an enhanced risk of
violent storms.Els medicanes són un tipus de cicló poc freqüent, i amb certes particularitats, que es dóna al Mediterrani. Els medicanes tenen similituds amb els ciclons tropicals referents al seu desenvolupament (basat en el desequilibri termodinàmic entre mar-atmosfera) i les propietats cinemàtiques i termodinàmiques (els medicanes són vòrtexs intensos amb nucli càlid i, algunes vegades, ns i tot poden tenir un ull lliure de núvols). Malgrat els medicanes són més petits i els seus vents associats són més febles que als ciclons tropicals, la força dels seus vents poden causar importants danys a illes i zones costeres. Les característiques especials dels medicanes fan que la seva detecció sia difícil: sols disposant de dades d'anàlisi meteorològiques a molta alta resolució i una xarxa densa d'observacions marítimes, aquesta tasca es podria dur a terme. Per aquest motiu, en aquesta tesi s'ha utilitzat un mètode alternatiu utilitzant imatges de satèl ·lit i aplicant criteris restrictius basats en la simetria de la pertorbació, la mida i la durada. D'aquesta manera s'han detectat 12 medicanes durant el període comprès des de 1982 a 2003. Una bona caracterització dels ambients meteorològics precursors dels medicanes ens pot ajudar a entendre els mecanismes de gènesi i millorar les prediccions. En aquesta tesi es comparen els valors de diverses variables meteorològiques d'interès en els medicanes amb els ambients d'altres ciclons intensos sobre la Mediterrània. En aquest sentit, valors elevats de la humitat relativa a nivells mitjos, la contribució diabàtica a la tendència local de temperatura potencial equivalent super cial, i valors baixos de la cisalla de vent entre nivells baixos i alts, pareixen paràmetres importants relacionats amb la gènesi dels medicanes, com també ho són dels ciclons tropicals. Un índex empíric de gènesi, provinent d'estudis sobre les regions tropicals, també ha estat avaluat en aquesta tesi i es presenta com un possible paràmetre discriminant dels ambients precursors. Malgrat la mida petita dels medicanes, s'ha comprovat que simulacions amb l'MM5 amb resolucions espacials de 7.5 km poden representar la formació de ciclons subsinòptics i les seves trajectòries, i per a la majoria dels casos també l'estructura simètrica amb nucli càlid. A més, s'ha realitzat una anàlisi de sensitivitat examinant el paper dels uxos de calor en la superfície de la mar: s'han desactivat l'intercanvi de calor latent i sensible sobre la Mediterrània durant les simulacions per estudiar els efectes d'aquests factors sobre les trajectòries i la intensi cació dels medicanes. Els resultats mostren tres patrons de comportament diferents sobre aquestes propietats dels medicanes identi cats prèviament, depenent de la magnitud i la distribució espacial dels uxos. En relació a la creixent preocupació sobre com afectarà el canvi climàtic a la freqüència i intensitat dels huracans, s'han realitzat dues anàlisis independents referent als medicanes: regionalitzacions dinàmiques de manera dirigida, i detecció directa sobre un model climàtic global a alta resolució. Per una part, les regionalitzacions dinàmiques consisteixen en determinar les zones d'alt risc mitjançant l'índex empíric descrit anteriorment i simular sols aquests ambients amb un model de mesoscala (aquest es força amb quatre models climàtics globals de resolucions espacials de l'ordre de 200 km). Per altra part, la detecció directa es realitza sobre un model climàtic global a una resolució aproximada de 25 km. En ambdós casos, els resultats mostren una reducció en la freqüència dels medicanes i assenyalen el sud-est d'Itàlia i el golf de Lleó com les zones amb major probabilitat de desenvolupament de medicanes en escenaris de clima futur. Referent als canvis d'intensitat en el futur, pareix que hi ha indicis d'augment del risc de tempestes violentes.
16
Meagher-Stewart, Donna. "Public health nurses' community development practice with women in high-risk environments." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/NQ63625.pdf.
Full text
17
Velasquez, Nicole Forsgren. "An Examination of Work Practices and Tool Use in High Risk Environments." Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/195045.
Full textAbstract:
This research presents an in-depth investigation and description of a single user group, system administrators. Following an overview of these computing professionals and their complex, risky work environment, system administrator work practices were investigated using data collected from previous experience, interviews, a usability study, and the literature. This research contributes to existing knowledge by presenting an analysis of system administrator work practices and identifying them as broker technicians. As such, many of the findings of this study may apply to other broker technicians. Because the work of system administration is so dependent upon technology and the way sysadmins access and control that technology, investigations of tool use were then studied. Through an analysis of work practices related to tool use, attributes important to system administrator work practices were identified. These attributes fell into two categories: information quality (currency, completeness, accuracy, format, logging, and verification) and system quality (reliability, flexibility, integration, accessibility, speed, scriptability, credibility, situation awareness, and monitoring).This research proposes the use of Wixom and Todd's (2005) integrated user satisfaction model in the context of system administration. This theoretical model provides an opportunity to link the identified characteristics with system administrator beliefs and tool usage. This research contributes to existing knowledge by identifying information and system quality attributes important to system administrators, and empirically testing the modified user satisfaction model in the untested context of system administration. The user satisfaction model was found to be significant and predictive of system administrator tool use behaviors, with two information quality attributes (accuracy and verification) and two system quality attributes (reliability and credibility) significant.
18
Lambird, Kathleen Mairead Hoffman. "Family social environments and risk for eating disorders the emotion processing link /." Diss., Restricted to subscribing institutions, 2006. http://proquest.umi.com/pqdweb?did=1273112911&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Full text
19
Ayton, Benjamin James. "Risk-bounded autonomous information gathering for localization of phenomena in hazardous environments." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/113744.
Full textAbstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Aeronautics and Astronautics, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 147-150).
Exploration of new environments is often conducted in search of some phenomenon of interest. Examples include the search for extreme forms of life in the deep ocean or under the ice on Europa, or localizing resource deposits on the ocean floor. Exploration of all these environments is dangerous because of uncertainty in the environment and poorly characterized disturbances that can damage the exploration vehicle. Autonomous vehicles allows exploration in those environments where it is too dangerous or expensive to send a human-operated craft. Autonomous exploration has been well-studied from the perspective of information maximization, but information gathering has not been considered with the intention of localizing specific phenomena, nor has it been considered in environments where exploration can threaten the vehicle. This thesis addresses both challenges by introducing Risk-Bounded Adaptive Search, which maximizes the number of phenomena located while bounding the probability of mission failure by a user-defined threshold. The first innovation of this thesis is the development of a new information measure that focuses on locating instances of a specific phenomenon. Search for phenomena of interest is framed as a discrete space Markov Decision Process that is solved using forward search and receding horizon planning, with a reward function specified as the information gained about unobserved instances of the phenomenon of interest from measurements. Using this reward function, the number of phenomena located is increased compared to maximizing conventional information, as it steers the agent towards locations where phenomena are thought to exist so they are not bypassed when the belief state is high. The second innovation is a method of applying risk bounds as a function of the expected information gain of a policy over a planning horizon, in contrast to a static bound. This 'Performance-Guided Risk Bounding' system allows an MDP policy to be found that is slightly suboptimal if it has a substantially lower probability of failure, or accept more risk if the reward payoff is large. When applied to information gathering, it allows an autonomous agent to capitalize on high risk and high reward opportunities when they are seen, instead of ignoring them in an effort to conserve risk for the future, when it is ultimately less useful. Since interesting phenomena are often found in risky locations, the ability to take more risk when it is worthwhile results in more phenomena found overall. Finally, a modification to Monte Carlo Tree Search is introduced that implements Performance-Guided Risk Bounding. This allows Risk-Bounded Adaptive Search to be planned in an anytime manner. The output policy is limited to the states that are explored, but risk bounds that scale with the expected information gained over the explored states in the policy are still applied. The resulting policies are shown to converge to the results of forward search, and a few percent differences in phenomena found with an order of magnitude reduction in planning time.
by Benjamin James Ayton.
S.M.
20
Pauley, Wayne A. Jr. "An Empirical Study of Privacy Risk Assessment Methodologies in Cloud Computing Environments." NSUWorks, 2012. http://nsuworks.nova.edu/gscis_etd/271.
Full textAbstract:
Companies offering services on the Internet have led corporations to shift from the high cost of owning and maintaining stand-alone, privately-owned-and-operated infrastructure to a shared infrastructure model. These shared infrastructures are being offered by infrastructure service providers which have subscription, or pay-on-demand, charge models presenting compute and storage resources as a generalized utility. Utility based infrastructures that are run by service providers have been defined as "cloud computing" by the National Institute of Standards and Technology.
In the cloud computing model the concerns of security and privacy protections are exacerbated due to the requirement for an enterprise to allow third parties to own and manage the infrastructure and be custodians of the enterprises information. With this new architectural
model, there are new hybrid governance models designed to support complex and uncertain environments. The cloud also requires a common infrastructure that integrates originally separate
computing silos. Privacy and security policy awareness during provisioning and computing orchestration about data locality across domains and jurisdictions must be able to obey legal and regulatory constraints.
Commercial use of the Internet for electronic commerce has been growing at a phenomenal rate while consumer concern has also risen about the information gathered about them. Concern about privacy of data has been rated as the number one barrier by all industries.
The purpose of this dissertation is to perform an empirical study to determine if existing privacy assessment instruments adequately assess privacy risks when applied to cloud infrastructures. The methodology for determining this is to apply a specific set of privacy risk assessments against a three cloud environments. The assessments are run in the context of a typical web based application deployed against cloud providers that have the five key cloud tenets - on-demand/self-service, broad network access, resource pooling, rapid elasticity, and measured service.
21
Shettler, Lauren C. "Risk and Protective Factors for Adolescent Smoking in Rural versus Urban Environments." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/35134.
Full textAbstract:
Although considerable literature can be found concerning the etiology of cigarette smoking, research suggests that a major gap exists pertaining to predictors of adolescent smoking for rural populations. The purpose of this study is to compare risk and protective factors for adolescents living in rural and urban environments. An ecological framework was used to examine variables from the individual, family, peer, school, and community contexts. The influence of these variables was assessed on a sample of (n=3,166) 8th, 10th, and 12th grade students from Virginia public schools. Linear regression analyses revealed that parental attitudes and best friends' smoking behavior was influential in the smoking behavior of both rural and urban adolescents. School and community level variables were only influential in smoking behavior among the urban adolescents.Master of Science
22
Montelius, Malin. "Chlorine Cycling in Terrestrial Environments." Doctoral thesis, Linköpings universitet, Tema Miljöförändring, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-125913.
Full textAbstract:
Chlorinated organic compounds (Clorg) are produced naturally in soil. Formation and degradation of Clorg affect the chlorine (Cl) cycling in terrestrial environments and chlorine can be retained or released from soil. Cl is known to have the same behaviour as radioactive chlorine-36 (36Cl), a long-lived radioisotope with a half-life of 300,000 years. 36Cl attracts interest because of its presence in radioactive waste, making 36Cl a potential risk for humans and animals due to possible biological uptake. This thesis studies the distribution and cycling of chloride (Cl–) and Clorg in terrestrial environments by using laboratory controlled soil incubation studies and a forest field study. The results show higher amounts of Cl– and Clorg and higher chlorination rates in coniferous forest soils than in pasture and agricultural soils. Tree species is the most important factor regulating Cl– and Clorg levels, whereas geographical location, atmospheric deposition, and soil type are less important. The root zone was the most active site of the chlorination process. Moreover, this thesis confirms that bulk Clorg dechlorination rates are similar to, or higher than, chlorination rates and that there are at least two major Clorg pools, one being dechlorinated quickly and one remarkably slower. While chlorination rates were negatively influenced by nitrogen additions, dechlorination rates, seem unaffected by nitrogen. The results implicate that Cl cycling is highly active in soils and Cl– and Clorg levels result from a dynamic equilibrium between chlorination and dechlorination. Influence of tree species and the rapid and slow cycling of some Cl pools, are critical to consider in studies of Cl in terrestrial environments. This information can be used to better understand Cl in risk-assessment modelling including inorganic and organic 36Cl.Klorerade organiska föreningar (Clorg) bildas naturligt i mark och påverkar klorets kretslopp genom att de stannar kvar längre i marken. Detta stabila klor anses ha samma egenskaper som klor-36, som är en långlivad radioisotop med en halveringstid på 300 000 år. Klor-36 förekommer i olika typer av radioaktivt avfall och om klor-36 sprids i naturen finns det en potentiell risk för människor och djur genom biologiskt upptag. Syftet i denna avhandling är att öka kunskapen om fördelningen och cirkulationen av klorid (Cl-) och Clorg i terrestra miljöer med hjälp av studier i laboratoriemiljö samt en fältstudie i skogsmiljö. Resultaten visar att bildningshastigheten av Clorg är högst i barrskogsjord och rotzonen tycks vara en aktiv plats. Det finns också en större mängd Cl- och Clorg i barrskogsjordar än i betesmark och jordbruksmark. Den mest betydande faktorn som styr halterna av Cl- och Clorg är trädsort, medan geografiskt läge, atmosfäriskt nedfall, och jordmån är av mindre betydelse. Bildning och nedbrytning av Clorg sker med liknande hastigheter, men det tycks finnas två förråd av Clorg i jorden varav ett bryts ner snabbt och ett mer långsamt. Bildningshastigheten av Clorg är lägre i jordar med höga halter av kväve medan nedbrytningshastigheterna inte påverkas av kväve. Slutsatsen från studiernas resultat är att klor i hög grad är aktivt i mark och att Cl- och Clorg halterna bestäms av en dynamisk jämvikt mellan bildning och nedbrytning av Clorg. I studier av klor i terrestra miljöer bör trädsorters inverkan och nedbrytning av olika klorförråd beaktas då det kan ge varierande uppehållstider av Cl- och Clorg i mark. Denna information är viktig vid riskbedömningar av hur radioaktivt klor kan spridas och cirkulera vid en eventuell kärnkraftsolycka.
23
Sundqvist, Erik. "Protection of Non-Volatile Data in IaaS-environments." Thesis, Linköpings universitet, Institutionen för datavetenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-112954.
Full textAbstract:
Infrastructure-as-a-Service (IaaS) cloud solutions continue to experience growth, but many enterprises and organizations are of the opinion that cloud adoption has decreased security in several aspects. This thesis addresses protection of IaaS-environment non- volatile data. A risk analysis is conducted, using the CORAS method, to identify and evaluate risks, and to propose treatments to those risks considered non-acceptable. The complex and distributed nature of an IaaS deployment is investigated to identify di↵erent approaches to data protection using encryption in combination with Trusted Computing principles. Additionally, the outcome of the risk analysis is used to decide the advantages and/or drawbacks of the di↵erent approaches; encryption on the storage host, on the compute host or inside the virtual machine. As a result of this thesis, encryption on the compute host is decided to be most beneficial due to minimal needs for trust, minimal data exposure and key management aspects. At the same time, a high grade of automation can be obtained, retaining usability for cloud consumers without any specific security knowledge. A revisited risk analysis shows that both non- acceptable and acceptable risks are mitigated and partly eliminated, but leaves virtual machine security as an important topic for further research. Along with the risk analysis and treatment proposal, this thesis provides a proof-of-concept implementation using encryption and Trusted Computing on the compute host to protect block storage data in an OpenStack environment. The implementation directly follows the Domain-Based Storage Protection (DBSP) protocol, invented by Ericsson Research and SICS, for key management and attestation of involved hosts.
24
Griffiths, Patrick, and patrick griffiths@rmit edu au. "Confluence and consequence: globalisation, viscosities and transformation of HIV risk environments in Vietnam." RMIT University. Applied Communication, 2006. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20070626.162522.
Full textAbstract:
This thesis shows that illicit drug consumers in Vietnam who administer product via injection are vulnerable actors in a paradoxical global/glocal phenomenon rooted in historical complexities of globalisation. Therefore, responsibility for HIV risks should be shifted upstream from the level of individuals toward institutional processes that manufacture environments of harm. At the global level, the UN Milennium Development Goals do not provide the required level of leadership on HIV prevention for drug injectors. Association between globalisation, opiates and blood-born disease in Vietnam is not new and is inseparable from historical transportation, migration and trade processes. As a key locale in the Cold War, after 1975, and 1979 in particular, Vietnam was 'at distance' from increasing intra-regional trade flows across its western frontiers and northern border. As a consequence, it was hermetically sealed to nearby HIV sub-epidemics unfolding among heroin cons umers. A latent HIV risk environment awaited Vietnam should geopolitical grievances be resolved and it became re-integrated among Mekong sub-regional flows. Neo-liberal financial flows returned to Vietnam in 1993 and the Mekong was spanned in 1994. In 1995 it normalised relations with the United States, joined ASEAN and announced the resurrection of transportation linkages across the northern border with China. Mid-decade, its borders were made more porous at the same time as local opium production was reduced as part of the UN global programme against drugs. Exploiting enhanced trans-boundary mobilities intended for goods, opiate traffickers quickly transformed Vietnam into a transit nation and a marke for high-quality heroin well suited to a youthful population experiencing socio-economic change including new consumerism. Following traditional pathways, a radical transformation in the fluidity of drug consumption environs ensued, enabling more widespread and efficient flows of blood across complex boundari es. Analysis reveals that a spatio-temporal confluence of structural factors has created conditions which enabled this process. These factors are overlapping and they range from global influences, such as the collapse of the USSR, to micro-economic reform such as privatisation and modernisation of the domestic pharmaceutical sector. The transformation in opiate consumption from injecting opium to heroin injecting occurred faster than expert-driven prevention systems responded, even in time and space where this was most forseeable. Although the opiate transformation was highly predictable, there has been a time-lag of almost a decade between risk transformations and policy responses equated with harm reduction principles. The thesis shows that blame for HIV sub-epidemics in Vietnam should not be attributed to vulnerable youths and young adults. Expert-driven economic transition associated with global inegration has manufactured circumstances in which drug availability has risen dramatically at a time when emp loyment growth has been insufficient and a commercial sex industry has expanded. This research confirms the cimportance of new methods of risk environment analyses, particularly in relation to trans-boundary hazards associated with global flows, including trade and human mobilities.
25
Keogh, Blake. "Preemptive Decision Making in Backcountry Skiing| Diversifying Risk Management Strategies in Complex Environments." Thesis, Prescott College, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1583767.
Full textAbstract:
The backcountry skiing population has increased significantly over the past ten years. Current sales of backcountry ski and rescue gear outpace more traditional alpine, telemark, and snowboarding equipment. As higher numbers of people head into avalanche terrain more fatal accidents are occurring, human triggered avalanches being the primary cause of death. In the late 1980s there were an average of 11 avalanche related deaths per year in the United States. That number has risen to an average of 30 over the past five years. Over that time avalanche specific rescue gear has been quick to adapt to the changing needs of backcountry skiers. However, over that same period of time theoretical approaches to risk management have been slow to adjust to the community's changing needs. Consequently, this study examined the preemptive decisions and the risk perceptions skiers held as they prepared to enter Tuckerman Ravine. Results show that 69% of the survey population did not have formal avalanche training. Despite significant technological advances 56% of the survey population did not have everyone in their group carry a beacon, shovel and probe. Fifty-one percent of the survey population strongly disagreed with frequent beacon practice. However, a skier was more likely to practice with their beacon if they had taken a formal avalanche course. Women were less likely to feel as though the trip were a failure if goals were not met. Additionally, the underrepresentation of women in this study (n=4) required an assessment of broader gender disparities within the backcountry skiing community. Quantitative and qualitative results show a lack of female leadership among recreational backcountry skiers. This leadership gap limits mentoring opportunities and decreases accessibility to the community for novice female backcountry skiers. The lack of gender diversification has significant affects on the decision-making process. This study concludes that dual-process cognitive methods and multilayered risk management protocols can increase margins of safety and encourage diverse perspectives within the larger backcountry skiing community. This paper suggests that because backcountry skiing involves the interconnection between complex adaptive systems and complex physical systems skiers should adopt a systems thinking approach to their decision-making processes.
Keywords: Systems thinking, avalanches, dual-process cognition, complexity, preemptive decision making, risk management, female backcountry leadership, risk perception, human triggered avalanches.
26
O'Gorman, Aileen. "Drug problems and social exclusion : the development of heroin careers in risk environments." Thesis, Middlesex University, 2005. http://eprints.mdx.ac.uk/6939/.
Full textAbstract:
The location-specificd rug scenesi dentified in Ireland and the UK in the 1980s indicated that problem drug use had a particular social and spatial focus in urban working-class communities, particularly those affected by unemployment and deprivation. This thesis explores localised drug problems in a number of disadvantaged neighbourhoods of Dublin by locating the perspective and experience of heroin users within the context of the social and economic contexts in which they live and operate. Taking a critical interpretivist methodological approach, the concepts of social exclusion and risk environments are used as heuristic devices for understanding the context in which problematic drug careers develop in marginalised areas. Using a multi-method research design, the study draws on secondary demographic, socioeconomic and policy data to provide a contextual framework of risk environments. The study then explores the development of heroin careers and the lived experience of social exclusion through in-depth qualitative interviews with sixty-one heroin users and an ethnographic study of the five socially excluded Dublin neighbourhoods in which they lived. An inductive analysis of the themes arising from the data describes the interactive dynamics at play in which social and structural processes are seen to both facilitate, and be facilitated by, local drug problems. The multiple and interconnected risks that drug users are seen to encounter at both a micro and macro environmental level contributes to our knowledge of localised drug problems and their relationship with social exclusion, and leads to the development of the concept of a risk environment for drug problems with consequent potential for informing grounded policy interventions.
27
Raghu, Arvind. "Mobile health for cardiovascular disease risk prediction and management in resource constrained environments." Thesis, University of Oxford, 2015. https://ora.ox.ac.uk/objects/uuid:aa9a4ebe-0214-47f5-b20d-cc3b9201fe83.
Full textAbstract:
It is well established that the leading global cause of mortality and morbidity, cardiovascular disease (CVD), is more severe in resource-constrained environments such as rural India (RI). This thesis explores how best to manage CVD risk in RI by using a mobile-based, point-of- care (POC) Clinical Decision Support System (CDSS), SMARThealth, that is designed to assist Accredited Social Health Activists (ASHAs) or minimally trained health workers. The four major focus areas are: (a) Design, development, and large-scale data collection using SMARThealth - an agile development process and user-centred design approach were followed to pilot test the CDSS with 292 participants. Evaluation metrics included system efficiency, end-user variability, usability, and sub-group analysis to identify better or poorly performing ASHAs. An improved version of SMARThealth was used for baseline data collection across 54 villages (62,194 participants) in Andhra Pradesh, India. 9864 (15.8%) of the participants were at high CVD risk. (b) Improvement of the sole CVD risk prediction algorithm for RI, the WHO/ISH CVD risk prediction charts (WHO-ISHc) - the choice of the low information (LI) model or high information (HI) model of WHO-ISHc was statistically significant for CVD risk prediction in RI (p=0.008;X2=7.03) with 155 subjects (or 14.5% of 1066 patients) having different CVD risk scores according to the LI and HI WHO-ISHc. A parsimonious POC test was developed to identify patients for whom risk prediction by the HI and LI WHO/ISHc differ (that is, for whom the assessment of total cholesterol would be beneficial). The POC test showed good discrimination (out-of-sample AUC 0.85 with Random Forests). (c) Assessment of best prediction algorithm for RI - eight highly predictive features of CVD risk were identified based on labelled data, and the resulting model (Model 1) had higher or equal AUCs and log-likelihood scores, and lower Brier scores when compared to a benchmark algorithm. The contribution of age and gender alone offered good discrimination and recalibration of Model 1 for RI was introduced. The lack of recorded end outcomes in RI prompted the use of an unsupervised approach to identify high-risk patients. Clusters of low and high CVD risks were found when K =2, but also clusters with intermediate risk when K =4 offering an alternative approach to identifying groups of high-risk patients. (d) Analysis from a randomised controlled trial evaluation of SMARThealth - preliminary data analysis of 131 high-risk patients during the first year of the randomised controlled trial showed a statistically significant reduction in median blood pressure between the 1st and 5th assessment (p=0.0097). The proportion of patients under treatment for high blood pressure continued to increase throughout.
28
Dai, Chengzhen L. "Multi-site sampling and risk prioritization of antibiotic resistance genes in sewage environments." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/121666.
Full textAbstract:
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Thesis: M. Eng., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2019
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 43-46).
The spread of antibiotic resistance across human and environmental habitats is a global public health challenge. In this study, we investigate the public health relevance of antibiotic resistance found in wastewater by combining metagenomic sequencing of wastewater environments with risk prioritization of resistance genes. We find that many of the genes commonly found in wastewater are not readily present in humans. Ranking antibiotic resistance genes based on their potential pathogenicity and mobility reveals that most of the antibiotic resistance genes in wastewater are not directly clinically relevant. Residential sewage was found to be of greater risk to human health than wastewater treatment plants and can be as risky as hospital effluent. Across countries, we show that differences in antibiotic resistance can, in some cases, resemble differences in antibiotic drug consumption. Finally, we find that the flow of antibiotic resistance genes is influenced by geographical distance and environmental selection.
by Chengzhen L. Dai.
M. Eng.
M.Eng. Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science
29
Alhadab, Mohammad Muflih Salem. "Real and accrual earnings management, regulatory environments, audit quality and IPO failure risk." Thesis, University of Leeds, 2012. http://etheses.whiterose.ac.uk/4876/.
Full textAbstract:
This thesis builds on information asymmetry, agency conflicts and litigation-risk backgrounds to examine real and accrual earnings management activities around Initial Public Offerings (IPOs), mitigating factors (regulators and auditors), and consequences for future performance (stock return and IPO survivability). The IPO event is associated with higher levels of information asymmetry and agency conflicts between insiders and outsiders that are found to provide managers with strong incentives and more flexibility to engage in earnings management activities to maximise their wealth instead of shareholders. Due to the existence of information asymmetry around IPOs, IPO firms hire high quality auditors during the IPO to send positive signals about the offer to outside investors (Titman and Trueman, 1986). The first empirical study (chapter five) of this thesis examines whether different regulatory environments impact the use of real and accrual earnings management around IPOs via an analysis of the heavily regulated Main market of the London Stock Exchange and the more lightly regulated Alternative Investment Market (AIM), and whether these different regulatory burdens (restrictive vs. lighter) have different mechanisms/capabilities to correct stock prices that were inflated by earnings management during the IPO. The results of this study show that IPO firms in the UK manage earnings upward utilizing both real and accrual earnings management around IPOs, and that IPO firms on the lightly regulated AIM market exhibit higher levels of sales-based and accrual-based and a lower level of discretionary expenses-based earnings management than IPO firms on the heavily regulated Main market. Further, the results show that real and accrual earnings management, which take place during the IPO year, have severe negative consequences for post-IPO stock return performance, and that the heavily regulated Main market of the London Stock Exchange has better mechanisms-capabilities to correct stock prices that were inflated by earnings management during the IPO year than the lighter regulated AIM market. audit quality impacts real earnings management activities that occur during the IPO, whether enhanced audit quality impacts managers’ tendency to choose between real and accrual earnings management, and whether enhanced audit quality affects the association between real and accrual earnings management and post-IPO stock return performance. The results show that high quality auditors mitigate real earnings management activities that occur through discretionary expenses-based manipulation during the IPO year, and that IPO firms audited by high quality auditors (big N audit firms) undertake a higher level of sales-based manipulation to avoid the monitoring of discretionary expenses-based and accrual-based manipulations. Further, IPO firms audited by high quality auditors are found to experience a severe decline in post-IPO stock return performance due to the extensive use of sales-based manipulation at the IPO year. Thus, this evidence confirms that high quality auditors impact the relationship between real and accrual earnings management and post-IPO stock return performance. Finally, the third empirical study (chapter seven) explores whether real and accrual earnings management that occur during the IPO year are associated with post-IPO failure and survivability in the subsequent periods. The results show that IPO firms with high levels of real and accrual earnings management during the IPO year have a higher probability of failure in the subsequent period. Further, IPO firms that engage in high levels of real and accrual earnings management during the IPO year have lower survival rates in the post-IPO period. In summary, the main findings of this thesis suggest that real and accrual earnings management activities are utilized by IPO firms, that the level of utilizing these activities is dependent on the regulatory environment and audit quality, and that these activities are negatively associated with future stock performance and post-IPO survivorship. Regulators and audit firms should consider the fact that managers switch between real and accrual earnings management to avoid external monitoring. Further, the greater restriction on discretionary expenses-based and accrual-based manipulation seems to lead managers to engage extensively in sales-based manipulation.
30
Parkin, Stephen George. "The effects of place on health risk : a qualitative study of micro-injecting environments." Thesis, University of Plymouth, 2009. http://hdl.handle.net/10026.1/2149.
Full textAbstract:
This thesis examines the relationship between place and health-risk in the context of injecting drug use; with specific focus upon such practice that is located within public and semi-public locations. The research followed phenomenological and ethnographic traditions; complemented by interview data and the exploratory application of visual methods (photography and video). This qualitative research was therefore designed to articulate the essence of public injecting in an urban setting within the UK and provide more nuanced understandings of the relationship between injecting drug use, health-risk and the socio-physical environments in which drugs are injected. This study focused upon the public injecting experience of 31 individuals and considered their motivations, injecting technique (and associated hygiene) and risk/safety management strategies associated with such drug use. The research was further guided by critical theory for considering the role of structure and agency. More specifically, the agency of public injectors was analysed within the theoretical frameworks advocated by Pierre Bourdieu concerning habitus, capital, field and the logics of practice. A wide range of minor harms and major hazards were identified with participation in public injecting. However, those harms and hazards identified were not necessarily unique to the public injecting phenomenon and may be experiences noted within wider drug-injecting practice. Nevertheless, it is the preparedness of public injectors to risk these harms that opportunities for hazard are increased in public settings. Accordingly, the effect of spatially located injecting drug use (in public/semi-public settings) upon health risk may be summarised as one that, in contemporary contexts, amplifies existing injecting related risk and harm. In Bourdieusian terminology, the logic of practice that ensues from the inter-relationality of habitus and capital, within the field of public injecting, is characterised by a commitment to a doxic attitude of resistance (situated and symbolic). Furthermore, these resistance strategies establish an illusio of harm and hazard that is both embodied and embedded within the logic of practice. Consequently, this thesis provides an empirical assessment of social issues (injecting drug use, place and health) rarely addressed by Bourdieu's key contributions to sociological discourse.
31
O'Hara, M. "Floods, flood damage and flood risk assessment in tropical environments : A Jamaican case study." Thesis, University of Exeter, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.232974.
Full text
32
Suppes, Laura Michele. "Exposures and Risks Associated with Activities and Behaviors in Swimming Pool Environments." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/293495.
Full textAbstract:
Enteric pathogens in pool water can be unintentionally ingested during swimming, increasing the risk of Acute Gastrointestinal Illness. Swimmer activities and behaviors influence pool water ingestion rates, and can be quantified for use in risk assessment. Enteric infection risk estimates help identify data gaps, areas to focus resources, and research needs. Primary objectives of this study were to develop electronic, self-administered "exposure" and "pool operations" questionnaires; to gather swimmer behavior and activity data for use in risk assessment; and to estimate Cryptosporidium parvum infection risk in swimmers. Results were used to identify data gaps and future research needs relative to treated recreational water. To achieve these objectives, 126 swimmers were recruited at four pool sites in Tucson, Arizona, video-taped, and asked to complete a post-swim questionnaire. Forty-six of the 126 swimmers submitted a 24 hr post-swim urine sample for quantifying pool water ingestion. Head submersion frequency and duration and splashes to the face were observed and quantified in video analysis, and activities and behaviors were reported on the exposure questionnaire. Variable data were analyzed for associations with pool water ingestion estimated by urinalysis. Results indicate questionnaires can be self-administered electronically; the exposure questionnaire can be used to estimate ingestion magnitude in place of urinalysis; leisure swimming activities (diving, playing, splashing, wading, sitting) and frequency of face splashes are ingestion exposure factors; and that Cryptosporidium infection risk is greatest among leisure swimmers. Other activities observed and suspected of having associations with ingestion were short submersion durations (<1 sec), and spitting and spouting water. More research and resources focused on improving treated recreational water environments and reducing risks among swimmers are needed. Developing an indicator organism test representative of Cryptosporidium, a monitoring program for treated recreational water, education aimed at leisure swimmer, and routine engineering and administrative controls are recommended. Swimming is a unique activity that can be enjoyed by people of all ages and abilities. Controlling hazards in pool environments reduces Recreational Waterborne Illness risks associated with pool water ingestion and improves the health and safety of swimmers.
33
Chu, Tai-wai David. "Oceanic hazard risk in low-lying areas of Hong Kong." Click to view the E-thesis via HKUTO, 2007. http://sunzi.lib.hku.hk/hkuto/record/B38849355.
Full text
34
Milloy, Michael-John Sheridan. "Harm production : correctional environments, injection drug users and risk of infection with blood-borne pathogens." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/3433.
Full textAbstract:
Background: Analyses of the individual-, social- and structural-level factors promoting
the transmission of HIV and other blood-borne pathogens have consistently identified
exposure to correctional environments, especially for individuals who use injection
drugs (IDU), as a risk factor for infection. The objectives of this project were: to review
the epidemiologic literature on incarceration and HIV infection among IDU, critically
examining evidence presented supporting a causal linkage between imprisonment and
infection; to investigate incarceration experiences in a cohort of active IDU; and to
assess the possible effects of incarceration on the post-release risk environment of
active IDU.
Methods: Longitudinal datasets for quantitative analyses were derived from the
Vancouver Injection Drug User Study (VIDUS) and the Scientific Evaluation of
Supervised Injection (SEOSI), both prospective cohorts of IDU in Vancouver’s
Downtown Eastside neighbourhood. In the first analysis, the prevalence and correlates
of reporting incarceration in the the previous six months were identified in SEOSI using
generalized estimating equations (GEE). In the second analysis, the possible effect of
imprisonment on the prevalence of risk factors for HIV infection was estimated in
VIDUS using linear growth curve analysis.
Results: In the first analysis, 902 individuals interviewed at least once between 1 July
2004 and 30 June 2006 were included. Overall, 423 (46.9%) reported an incarceration
event at some point during the study period. In a multivariate GEE model, recent
incarceration was independently associated with a number of high-risk factors,
including syringe sharing. In the second analysis, 1603 individuals were interviewed at
least once between 1 May 1996 and 31 December 2005 and in cluded. Of these, 147
(9.2%) matched the study criteria and were included as cases; 742 (46.3%) were included
as matched controls. In linear growth curve analyses adjusted for age, gender and
ethnicity, syringe sharing was significantly more common in the incarcerated group (p
= 0.03) after incarceration than in the control group.
Conclusions: Our findings support the existence of a role for incarceration in continued
viral transmission. In response, appropriate harm reduction measures should be
expanded within correctional environments and social, political and legal reforms
enacted to reduce the incidence of imprisonment for individuals who use illicit drugs.
35
Bouanchaud, Paul Alexandre. "Male sex work in China : understanding the HIV risk environments of Shenzhen's migrant money boys." Thesis, London School of Economics and Political Science (University of London), 2014. http://etheses.lse.ac.uk/1065/.
Full textAbstract:
This study contributes to our understanding of the social organisation and lived experience of men in China’s sex industry. It employs a social epidemiological model to analyse the multiple levels of influence on HIV (and other non-HIV) risks to which this highly marginalised group are exposed. It highlights the complex interrelations between different factors influencing the lives of male and transgender sex workers (MSW) in China. It is the first mixed methods study of its kind in the Chinese MSW context. The thesis analyses data collected during five months of fieldwork in Shenzhen, China. Working through a community-based MSW organisation, a participatory approach was taken to study design and data collection. Community advisory boards were organised and used to develop and test study instruments. A structured survey was undertaken with MSW (n=251), with a sub-sample purposely selected for semistructured interviews (n=21). Key informant interviews were conducted with representatives from local and international organisations (n=5). Multiple linear and binary logistic regressions were used for quantitative data analyses, while qualitative data were coded thematically. Both data types are given equal weight throughout the analysis. The thesis demonstrates how China’s recent macro-level social and economic changes, characterised here through the microcosm of life in the city of Shenzhen, interact with the lived experiences of the men in the study, driving their rural-urban migration and contributing to their entry into sex work. The phrase “laugh at poverty, not at prostitution” was used by many of the respondents to explain their decision to sell sex, but this apparently simple idiom belies a more complex reality in which economic factors intersect with social networks, sexual orientation and an escalation in the provision of sexual services. Sex work careers are represented as providing both opportunities (for escaping poverty, expressing sexual identity, and accessing cosmopolitan lifestyles), as well as risks. Risk, understood as a socially constructed phenomenon, refers not only to HIV transmission, but also violence from clients, control by mami (pimps), and entrapment and arrest by the police. Multiple risks and opportunities arise through a range of social and professional interactions between the different actors involved in the industry, necessitating their dynamic management by the MSW. Sex work, HIV and homosexuality alongside migrant identities are highly stigmatised in China, and the active management of these intersecting identities, in part through their sexual practices, allows the MSW in this study to continue in their work without ‘losing face’. The MSW have complex sexual networks of male and female, paid and paying, and non-commercial partners. In exploring their partner concurrency, this complexity is examined, through the lenses of stigma and identity. Local, emic understandings of ‘safe sex’ indicate that while levels of HIV fear are substantial among the MSW, and condom use is commonly discussed, safety and hygiene are frequently conflated, and both are associated with HIV-avoidance. Hygiene, through showering and general cleanliness, is considered an important part of ‘safe sex’ for this group, but also emerges as a metaphor employed to counter the perceived dirtiness of selling sex for some of the MSW. The findings highlight the complexities involved in selling sex for these men. They must actively negotiate their work, risks and identities, while also being subject to unequal power relations and forces largely beyond their control. This thesis aims to present a nuanced account of these dynamic processes.
36
Alt, Jeromy. "The effect of task demand on decision making in dynamic, sport-like virtual environments." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1584015762619272.
Full text
37
Ojemaye, Cecilia Yejide. "Identification and quantification of chemicals of emerging concern (persistence organic and inorganic pollutants) in some selected marine environments of Cape Town, South Africa." University of Western Cape, 2020. http://hdl.handle.net/11394/7697.
Full textAbstract:
Philosophiae Doctor - PhDThe increasing evidence of chemicals of emerging concern (CECs) in water bodies is causing major concern around the world because of their toxicological effects upon humans and aquatic organisms. The release of wastewater to the aquatic environment is most likely to introduce some trace levels of organic contaminants, some of which may be toxic, carcinogenic, or endocrine disruptors, as well as, persistent in the environment. These compounds are often persistent but not regularly monitored because they are mostly still excluded from environmental legislation. Their fate and persistence in the environment are not well understood
38
McMahan, John Benjamin. "Environments Of Risk In A Dynamic Social Landscape: Hurricanes And Disaster On The United States Gulf Coast." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/337288.
Full textAbstract:
Hurricanes pose a challenge for residents and communities of the United States Gulf Coast. The people that live in the region must adapt and respond to these storms, as do the social institutions that provide support during disasters and their aftermath. This is complicated by the longstanding and ongoing relationship between the oil and gas industry and gulf coastal communities, especially as activities associated with oil and gas development alter the local environments and regional landscapes in ways that increase vulnerability. These vulnerabilities layer onto existing social inequalities and make management and protection of regional populations difficult, and complicate recovery efforts. In this dissertation I explore the relationships between people, communities, industry, and social institutions. I trace the recent history of gulf coast storms in the region, emergent and developing strategies for preparation and recovery, and ongoing contention embedded within policy and governance issues. I also consider the complex interaction between social and natural systems, the role of government and support networks in providing assistance, and the locus of responsibility in mitigating vulnerability and providing support, before, during, and after a disaster.
39
De, Waal Caroli. "Dispersal, dormancy, life history and breeding systems of southern African Asteraceae : risk-reducing strategies in unpredictable environments." Thesis, Stellenbosch : Stellenbosch University, 2015. http://hdl.handle.net/10019.1/96736.
Full textAbstract:
Thesis (PhD)--Stellenbosch University, 2015.ENGLISH ABSTRACT: How organisms respond to unpredictable environments is a fundamental question in evolutionary ecology. For example, plants may reduce the risk of reproductive failure by spreading their reproductive effort in space (dispersal) or in time (dormancy, iteroparity). Similarly, different plant breeding systems, (for example the ability to autonomously self-fertilise) may reduce the risk of reproductive failure in environments where pollination in particular is unreliable. Each of these strategies may be affected by selective pressures exerted by heterogeneous abiotic and biotic environments (e.g. unreliable rainfall patterns or range edge habitats). However, there is little theoretical or empirical consensus on how these strategies are related. In Chapter 2, I explore the association between dispersal and breeding system traits and range edge proximity. I show that annual daisies from Namaqualand, South Africa, are characterised by two discreet syndromes: high selfing ability associated with good dispersal and obligate outcrossing associated with lower dispersal, regardless of range position. This chapter illustrates that selection on both breeding system and dispersal traits may act consistently across distribution ranges. Because co-flowering plants often share pollinators, their fecundity is likely affected by changes in pollinator visitation rates or the transfer of conspecific relative to heterospecific pollen. In Chapter 3 I experimentally investigate the effects of con- and heterospecific density and spatial distribution pattern on pollination and fecundity in annual Namaqualand daisies. I show that increasing conspecific density and aggregation enhanced fecundity through increased mate availability and reduced heterospecific interference, independent of pollinator visitation rates. Moreover, I demonstrate the benefits of autonomous selfing when mates are limited and the potential for interspecific pollen transfer is high. In Chapter 4, I examine relative investment in dispersal vs. dormancy in seed heteromorphic Dimorphotheca (Asteraceae) species in relation to life history, rainfall unpredictability and range edge proximity. I show annuals and perennials differ significantly in the relative investment in different dispersal strategies. However, my findings provide little support for theoretical predictions of bet-hedging strategies in unpredictable or range edge habitats. This chapter emphasises the role of local environmental factors on fruit set that may obscure expected patterns across broad climatic gradients. Because of different costs and benefits of dispersal in space and time, we may expect negative patterns of covariation among dispersal and dormancy as alternative risk-reducing strategies. In Chapter 5, I provide evidence for a trade-off between these traits across 27 wind- dispersed daisy species from South Africa. This trade-off did not depend on life history effects, but was inconsistent at different levels of biological organisation. I also show that the effects of life history on spatial and temporal dispersal were inconsistent. Taken together, my research illustrates the importance of simultaneously investigating different risk-reducing strategies, because associations among them are clearly complex and often contradict theoretical expectations. Moreover I show that the effects of life history and phylogenetic relatedness cannot be disregarded. My findings underscore the importance of dispersal in space and time as well as autonomous selfing as risk-reducing responses to unreliable environments.
40
Slater, Andrew James. "High-risk sexual behaviours between men who have sex with men in public sex environments and venues." Thesis, Manchester Metropolitan University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434884.
Full text
41
Sliva, Francisco. "Managing high-risk, technology-intensive companies in heavily regulated environments : two case studies in the nuclear industry." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12726.
Full text
42
Bustillos, Ardaya Alicia [Verfasser]. "Applying Disaster Risk Governance in Dynamic Environments : Case study Rio de Janeiro State, Brazil / Alicia Bustillos Ardaya." Bonn : Universitäts- und Landesbibliothek Bonn, 2021. http://d-nb.info/1235525783/34.
Full text
43
Mueller, Jennifer M. "The Effects of Goal Framing on Auditors' Use of a Decision Aid in Environments of Varied Risk." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/37642.
Full textAbstract:
An auditor performing analytical review must typically diagnose material variances of observed client data from his/her own expectations. The auditor may utilize a decision aid to help in generating potential explanations for a variance; it has, however, the capacity to provide many more explanations than are possible using other means. Under the circumstances of budgetary constraints and limited cognitive load for beginning an information search with these explanations, the auditor may consider the lengthy list and arrive at a more manageable sub-list of the most probable explanations. In doing so, the auditor either eliminates those explanations that are less likely or includes those that are more likely into a reduced list for further consideration. While the goal under either approach is the same-to reduce the list-studies in psychology have shown that those including will reduce the list to a much greater extent than those eliminating. If the auditor begins an information search with this reduced list of explanations, then whether the auditor uses inclusion or elimination may have effectiveness and efficiency implications for the remainder of the analytical review process.
The auditor must also contend with risk in the audit environment, which also may influence the manner in which the auditor reduces the lengthy list of explanations. A risky audit environment is generally related to heightened auditor skepticism and increased audit effort, as predicted by the audit risk model (SAS 47, AICPA 1983). Each of these translates into the desire to pursue a greater number of plausible explanations in a high risk environment than in a low risk environment. Therefore, an auditor would be expected to reduce a decision-aid-provided list of explanations to a lesser degree in a high risk environment than a low risk environment.
The purpose of this dissertation was to investigate the occurrence of a goal framing effect at varied levels of client risk. Using a two-way between subjects design, auditors in this study either eliminated or included explanations from a decision-aid-provided list in a low risk or high risk analytical review setting. As suggested by the goal framing theory, auditors who eliminated concluded with significantly more explanations than those who included. Furthermore, as suggested by the audit risk model, auditors in a high risk environment concluded with significantly more explanations than auditors in a low risk environment.
Because previous auditing literature provides that auditor conservatism, which is heightened in periods of high risk, often mitigates biases and heuristics found in the general decision making or psychology literature, it was also predicted that in the high risk scenario, the influence of high risk in enlarging the set of explanations would overcome the influence of the inclusion goal framing in reducing the set of explanations. No support was found for this interaction.
The results of this study have implications for the implementation of decision aids in practice. This study advises that in various client risk settings, auditors evaluating a lengthy decision-aid-provided list of explanations by inclusion may arrive at a significantly smaller number of explanations than by elimination. Given that the subsequent step of analytical review-information search-is planned according to what the auditor believes are the plausible hypotheses, goal framing may have an impact on the overall efficiency and effectiveness of analytical review, in both high and low risk client scenarios.Ph. D.
44
Zaharescu, Dragos G., Peter S. Hooda, Carmen I. Burghelea, Viktor Polyakov, and Antonio Palanca-Soler. "Climate change enhances the mobilisation of naturally occurring metals in high altitude environments." ELSEVIER SCIENCE BV, 2016. http://hdl.handle.net/10150/615547.
Full textAbstract:
Manmade climate change has expressed a plethora of complex effects on Earth's biogeochemical compartments. Climate change may also affect the mobilisation of natural metal sources, with potential ecological consequences beyond mountains' geographical limits; however, this question has remained largely unexplored. We investigated this by analysing a number of key climatic factors in relationship with trace metal accumulation in the sediment core of a Pyrenean lake. The sediment metal contents showed increasing accumulation trend over time, and their levels varied in step with recent climate change. The findings further revealed that a rise in the elevation of freezing level, a general increase in the frequency of drier periods, changes in the frequency of winter freezing days and a reducing snow cover since the early 1980s, together are responsible for the observed variability and augmented accumulation of trace metals. Our results provide clear evidence of increased mobilisation of natural metal sources - an overlooked effect of climate change on the environment. With further alterations in climate equilibrium predicted over the ensuing decades, it is likely that mountain catchments in metamorphic areas may become significant sources of trace metals, with potentially harmful consequences for the wider environment.
45
Cocks, Adam James. "Testing attentional control theory in novel dynamic environments : the impact of anxiety on perceptual-cognitive and perceptual-motor skills." Thesis, Brunel University, 2016. http://bura.brunel.ac.uk/handle/2438/14689.
Full textAbstract:
The current body of work aims to apply Processing Efficiency Theory (PET) and Attentional Control Theory (ACT) to novel dynamic settings by examining how anxiety influences perceptual-cognitive and perceptual-motor skills. Sporting domains and fall-risk in older adults are studied. Applying ACT to a tennis anticipation paradigm examines whether state anxiety influences processing efficiency and the use of contextual information during anticipation. Processing efficiency was reduced under anxiety, while overall response accuracy was unchanged. Furthermore, skilled performers were seemingly less able to utilise contextual information when anxious. Studies in Chapters 4 and 5 sought to test the predictions of PET and ACT compared with those of Reinvestment Theory (RT) in the field of fall-risk in older adults. In Chapter 4, trait anxiety, alongside increasing dual-task demands, produced processing and motoric inefficiencies through reduced visual planning and mean gait velocity. Furthermore, greater and more variable gait velocity reductions were found in those with higher trait anxiety. By contrast, greater reinvestment levels were associated with poorer visuospatial recall, higher stepping accuracy, plus larger and less variable gait velocity reductions. Chapter 5 further investigates the motoric inefficiencies observed in anxious older adults’ gait. The influences of trait anxiety, movement specific reinvestment, and falls efficacy on body segmental control during adaptive turning are studied. Trait anxiety and falls efficacy were mainly shown to influence differing facets of turning behaviour, though both were associated with greater coupling of body segments (en-bloc rotations), whereas, limited support was offered for RT. Overall, PET and ACT were supported when applied to these new dynamic domains. However, discrepancies are discussed due to testing theoretical hypotheses in more representative environments.
46
Moen, Gjøran. "A Mobile Decision Support System for High Risk Environments : Built Using Heads Up Displays and Intelligent User Interfaces." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for datateknikk og informasjonsvitenskap, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-26753.
Full textAbstract:
This thesis describes the design of a system for decision support on the individual and organizational level, intended for use in military and emergency agencies. The system is intended to contribute to the users' situational awareness and ability to solve given tasks cooperatively.This is achieved by considering the context, such as the user's spatial context and internal mental and physiological states.The system is based on an intelligent agent based user interface and heads up displays (HUD) in the form of wearable off the shelf hardware such as Recon Instruments HUD products.Research in relevant disciplines covering, among other things, themes like physiological responses to psychological states and limitations of human visual perception is used to support design decisions.
47
Geiß, Christian. "Seismic vulnerability assessment of built environments with remote sensing." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2015. http://dx.doi.org/10.18452/17104.
Full textAbstract:
Globale Urbanisierungsprozesse und eine Zunahme der räumlichen Konzentration von exponierten Elementen wie Menschen, Gebäude, Infrastruktur und ökonomische Werte induzieren ein ungekanntes Risiko in erdbebengefährdeten Regionen. Wenn keine Abschwächung des Risikos erfolgt werden dramatische Folgen in der Zukunft erwartet. Diese umfassen eine beispiellose Anzahl an Todesopfer, enorme ökonomische und ökologische Verluste und Ausfälle bezüglich kritischer Infrastruktur und Versorgung etc. Um derartige Gefährdungen abzuschwächen sind detaillierte Informationen über seismisches Risiko notwendig. Die seismische Verwundbarkeit von Siedlungsarealen ist dabei als zentrale, konstituierende Komponente von seismischem Risiko zu berücksichtigen. In diesem Zusammenhang ist es von besonderem Interesse das Verhalten von Gebäudeinventaren unter einem bestimmten Erdbebeneinfluss abschätzen zu können. Das Hauptziel der Arbeit war es maßgeschneiderte Methoden zu entwickeln, die eine Bewertung der seismischen Vulnerabilität von Siedlungsräumen, basierend auf Fernerkundungsdaten, durchführbar machen. Es wurden Methoden aus dem Bereich des maschinellen Lernens adaptiert, um Verwundbarkeitsstufen von Gebäuden und homogenen Siedlungsstrukturen zu bestimmen. Hierfür wurden Merkmale aus Fernerkundungsdaten abgeleitet und mit in situ Informationen verknüpft. Wir verwenden verschiedene Ensembles von Fernerkundungssensoren, um die urbane Morphologie umfassend zu charakterisieren. Empirische Ergebnisse, die für die erdbebengefährdeten Städte Padang (Indonesien) und Istanbul (Türkei) generiert werden konnten, bestätigen die Durchführbarkeit der entwickelten Verfahren. Zukünftige Arbeiten können daran anknüpfen und beispielsweise empirische Erkenntnisse in weiteren Fallstudien anzweifeln, eine Verbesserung der Methodik vornehmen, Konzepte und Ansätze auf andere Sensorsysteme oder Datenquellen übertragen oder Daten und Methoden im Rahmen von holistischen Risikobewertungsstrategien anwenden.Global urbanization processes and increasing spatial concentration of exposed elements such as people, buildings, infrastructure, and economic values in earthquake prone regions induce seismic risk at a uniquely high level. This situation, when left unmitigated, is expected to cause unprecedented death tolls, enormous economic and ecological losses, and critical infrastructure and service failures, etc., in the future. To mitigate those perils requires detailed knowledge about seismic risks. As an important constituent element of seismic risk, the seismic vulnerability of the built environment has to be assessed. In particular, it is crucial to know about the behavior of the building inventory under a certain level of ground shaking. The main goal of the thesis was to develop and evaluate tailored methods and procedures that allow for a viable seismic vulnerability assessment of the built environment with remote sensing data. In particular, methods from the machine learning domain were adapted to estimate vulnerability levels of buildings and homogeneous urban structures based on features derived from remote sensing and by incorporation of in situ knowledge. To this purpose we deploy ensembles of earth observation sensors to exhaustively characterize the urban morphology. Empirical results, obtained for the earthquake prone cities Padang (Indonesia) and Istanbul (Turkey), confirm the viability of the approaches. Overall, this thesis provides some promising results, which show that remote sensing has a high capability to contribute to a rapid screening assessment of the seismic vulnerability of buildings and urban structures. Further work can build upon these results and may challenge empirical findings in further case studies, enhance developed and applied methods, transfer concepts and approaches to other sensor systems and data sources, or apply data and methodologies within integrative and holistic risk assessment strategies.
48
Johnson, Jared A. "A determination of the risk of intentional and unintentional electromagnetic radiation emitters degrading installed components in closed electromagnetic environments." Thesis, Monterey, California: Naval Postgraduate School, 2015. http://hdl.handle.net/10945/45882.
Full textAbstract:
Approved for public release; distribution is unlimitedThis report proposes a method of risk determination that incorporates a loss function and a probability function in order to better enable decision makers in determining the risk of implementing wireless technologies in reverberant enclosed spaces that contain sensitive installed components. There is a constant desire to include new technology into the systems being designed to operate onboard U.S. Naval vessels. One of these technologies is wireless communications. This technology relies on the use of the electromagnetic spectrum in order to transfer information from one point to another. This type of information transfer can be advantageous in various applications. Exposing sensitive electronic components to a time-varying electromagnetic field increases the risk of an electronic upset in those components that will degrade the functionality of installed systems. This risk determination should provide a way to weigh the risk of introducing wireless technologies in enclosed spaces. This risk determination relies on the assumption that at some point there will be enough data collected to properly determine the overall risk to at-risk equipment. Until that occurs, incorporating new methods of shielding and low power technologies is recommended.
49
Chu, Tai-wai David, and 朱大衛. "Oceanic hazard risk in low-lying areas of Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B38849355.
Full text
50
Cunningham, Carlton. "Using Learner Controlled Progress-Based Rewards to Promote Motivation and Achievement of At-Risk Students in Managed Online Learning Environments." NSUWorks, 2011. http://nsuworks.nova.edu/gscis_etd/126.
Full textAbstract:
Technology enhancements of the past two decades have not successfully overcome the problem of low motivation in Kindergarten through Grade 12 (K-12). Motivation and math achievement have been identified as major factors contributing to the high school dropout problem (30-50% in traditional/online programs). The impact of extrinsic rewards on achievement and the dropout problem, however, remains a subject of debate. This dissertation seeks first to address this debate, through an investigation of reward system effectiveness in the blended learning environment, on at-risk students with varied intrinsic motivation factor scores. Next, the dissertation explores the importance of fit between students' reward perceptions and reward values when motivating student progress. To this end, the author has developed a new 6-factor motivation orientation model for students in blended learning environments, and a learner-configurable progress-based reward system (PBR) for Learner Content Management Systems (LCMS) based on this model.
The hypothesized model was tested for fit with a sample of 353 at-risk high school math students in Miami, Florida. The PBR was developed based upon the findings from interviews with subject matter experts and students, factor and regression analyses used to test hypotheses about learner motivation and predict learner progress.
Conclusions from the study informed the design of an integrated PBR. A 6-factor motivation orientation model was found to explain more of the variance (74%) in student motivation than earlier models. Contrary to Deci et al. (1999), hypothesis test results did not confirm adversarial extrinsic rewards/intrinsic motivation relationships. Furthermore, consistent with person-environment fit theory, learners demonstrated superior progress and achievement when extrinsic reward perceptions and values were well aligned.
With critical input from flexible learning theorists, teachers, and students, the emerging PBR design may ultimately be integrated through mobile learning applications and social media, within LCMS solutions such as Blackboard, and systems commonly used in K-12, such as Apex. Although beyond the scope of the dissertation, the emerging Web-based design promises to play an important role in engaging a K-12 Community of Practice (CoP), consisting of telecommunications partners, game developers, retailers, and education stakeholders sharing a significant interest in future innovations that address the dropout problem.