Objectives This thesis is based on 4 papers that were all written with the same intent, which was to describe and demonstrate how epidemiologic concepts and data can serve as a basis for improved validity of probabilistic conclusions in forensic medicine (FM). Conclusions based on probability are common in FM, and the validity of probabilistic conclusions is dependant on their foundation, which is often no more than personal experience. Forensic epidemiology (FE) describes the use and application of epidemiologic methods and data to questions encountered in the practice of FM, as a means of providing an evidence-based foundation, and thus increased validity, for certain types of opinions. The 4 papers comprising this thesis describe 4 unique applications of FE that have the common goal of assessing probabilities associated with evidence gathered during the course of the investigation of traumatic injury and death.   Materials and Methods Paper I used a case study of a fatal traffic crash in which the seat position of the surviving occupant was uncertain as an example for describing a probabilistic approach to the investigation of occupant position in a fatal crash. The methods involved the matching of the occupants’ injuries to the vehicular and crash evidence in order to assess the probability that the surviving occupant was either the driver or passenger of the vehicle at the time of the crash. In the second and third papers, epidemiologic data pertaining to traffic crash-related injuries from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) was used to assess the utility and strength of evidence, such as vehicle deformation and occupant injury of a particular severity and pattern, as a means of assessing the probability of an uncertain issue of interest. The issue of interest in Paper II was the seat position of the occupant at the time of a rollover crash (similar to Paper I), and the association that was investigated was the relationship between the degree of downward roof deformation and likelihood of a serious head and neck injury in the occupant. The analysis was directed at the circumstance in which a vehicle has sustained roof deformation on one side but not the other, and only one of the occupants has sustained a serious head or neck injury. In Paper III the issue of interest was whether an occupant was using a seat belt prior to being ejected from a passenger vehicle, when there was evidence that the seat belt could have unlatched during a crash, and thus it was uncertain whether the occupant was restrained and then ejected after the seat belt unlatched, or unrestrained. Of particular interest was the relative frequency of injury to the upper extremity closest to the side window (the outboard upper extremity [OUE]), as several prior authors have postulated that during ejection when the seat belt has become unlatched the retracting seat belt would invariably cinch around the OUE and cause serious injury. In Paper IV the focus of the analysis was the predictability of the distribution of skull and cervical spine fractures associated with fatal falls as a function of the fall circumstances. Swedish autopsy data were used as the source material for this study. Results In Paper I the indifferent pre-crash probability that the survivor was the driver (0.5) was modified by the evidence to arrive at a post-test odds of 19 to 1 that he was driving. In Paper II NASS-CDS data for 960 (unweighted) occupants of rollover crashes were included in the analysis. The association between downward roof deformation and head and neck injury severity (as represented by a composite numerical value [HNISS] ranging from 1 to 75) was as follows: for each unit increase of the HNISS there were increased odds of 4% that the occupant was exposed to >8 cm of roof crush versus <8 cm; 6% for >15 cm compared to <8 cm, and 11% for >30 cm of roof crush compared to <8 cm. In Paper III NASS-CDS data for 232,931 (weighted) ejected occupants were included in the analysis, with 497 coded as seat belt failures, and 232,434 coded as unbelted. Of the 7 injury types included in the analysis, only OUE and serious head injury were found to have a significant adjusted association with seat belt failure, (OR=3.87, [95% CI 1.2, 13.0] and 3.1, [95% CI 1.0, 9.7], respectively). The results were used to construct a table of post-test probabilities that combined the derived sensitivity and (1 - specificity) rates with a range of pre-crash seat belt use rates so that the results could be used in an investigation of a suspected case of belt latch failure. In Paper IV, the circumstances of 1,008 fatal falls were grouped in 3 categories of increasing fall height; falls occurring at ground level, falls from a height of <3 meters or down stairs, and falls from ≥3 meters. Logistic regression modeling revealed significantly increased odds of skull base and lower cervical fracture in the middle (<3 m) and upper (≥3 m) fall height groups, relative to ground level falls, as follows: (lower cervical <3 m falls, OR = 2.55 [1.32, 4.92]; lower cervical ≥3 m falls, OR = 2.23 [0.98, 5.08]; skull base <3 m falls, OR = 1.82 [1.32, 2.50]; skull base ≥3 m falls, OR = 2.30 [1.55, 3.40]). Additionally, C0-C1 dislocations were strongly related to fall height, with an OR of 8.3 for the injury in a ≥3 m fall versus ground level. Conclusions In this thesis 4 applications of FE methodology were described. In all of the applications epidemiologic data resulting from prior FM investigations were analyzed in order to draw probabilistic conclusions that could be reliably applied to the circumstances of a specific investigation. It is hoped that this thesis will serve to demonstrate the utility of FE in enhancing evidence-based practice in FM.

This project examined the extent to which Nova Scotian adolescents’ counselling needs are being met with respect to physical, sexual, substance use, and psychosocial health by their family physicians. This was accomplished by assessing how well Nova Scotian physicians provide preventative advice consistent with the Guidelines for Adolescent Preventative Services (GAPS). Analyses were performed using pooled data from surveys carried out in 2003 and 2006. Descriptive analyses, Poisson and logistic regression were used to examine associations of sociodemographic characteristics, need, and the presence of school based health centres (SBHCs) with the provision of advice. Advice was not well provided and appeared to be need-driven. Females were significantly more likely to be provided advice and respondent access to a SBHC increased the likelihood of advice being provided. These results have implications for policy and practice, specifically, ways to refine preventative healthcare services for the province’s adolescents to ensure optimal care.

This thesis uses the Canadian Drugs and Alcohol survey conducted in 1994 by Statistics Canada to explore how Agnew’s (1992, 2001, 2006) general strain theory can help to understand drug and alcohol use in Canada. Agnew argues that experiences of strain, which include an array of negative life events, produce a negative emotional response which creates pressure for corrective action. In postulating why certain individuals are more likely to react to strain with deviant behaviour, Agnew (1992, 2001, 2006) emphasizes the importance of variables that condition the effects of strain on deviance. It is argued that people are less likely to respond to strain with deviant coping strategies depending upon their levels of social control, constraint, social support and deviant peers and values (Agnew 1992; Broidy and Agnew 1997; Agnew 2006). Results are very supportive of GST as measures of objective and subjective strains as well measures of the conditioning variables are consistently associated with drug and alcohol use in hypothesized directions; strain measures also tended to interact with conditioning variables in associations with substance use. Hypotheses surrounding gender differences were also supported as females generally scored higher than males on measures argued to protect against the effects of strain and lower on measures argued to encourage deviant coping. Additionally, objective financial strain tended to have a stronger effect on male substance use while subjective strains tended to be more important in the prediction of female substance use. Avenues for further research are discussed including ways to ameliorate the adaptation of GST to gendered substance use patterns. / Thesis (Master, Sociology) -- Queen's University, 2009-08-31 12:12:25.288

Baigiamojo darbo tikslas - išanalizuoti UAB „Vylaista“ logistinę veiklą ir pasiūlyti logistinės veiklos tobulinimo kryptis. / Goal of final Thesis - To analize logistic activities of JSC „Vylaista“ and to offer improvement directions of logistics process.

Tuberculosis (TB) is called a disease of poverty and is the main cause of death from infectious diseases among adults. In 1993 the World Health Organisation (WHO) declared TB to be a global emergency; however there were still approximately 1.4 million deaths due to TB in 2011. This thesis contains a detailed study of the existing literature regarding the global risk factors of TB. The risk factors identified from the literature review search which were also available from the NFHS-3 survey were then analysed to determine how well we could identify respondents who are at high risk of TB. We looked at the stigma and misconceptions people have regarding TB and include detailed reports from the existing literature of how a persons wealth, health, education, nutrition, and HIV status affect how likely the person is to have TB. The difference in the risk factor distribution for the TB and non-TB populations were examined and classification trees, nearest neighbours, and logistic regression models were trialled to determine if it was possible for respondents who were at high risk of TB to be identified. Finally gender-specific statistically likely directed acyclic graphs were created to visualise the most likely associations between the variables.

In a Bayesian framework, prior distributions on a space of nonparametric continuous distributions may be defined using Polya trees. This dissertation addresses statistical problems for which the Polya tree idea can be utilized to provide efficient and practical methodological solutions. One problem considered is the estimation of risks, odds ratios, or other similar measures that are derived by specifying a threshold for an observed continuous variable. It has been previously shown that fitting a linear model to the continuous outcome under the assumption of a logistic error distribution leads to more efficient odds ratio estimates. We will show that deviations from the assumption of logistic error can result in great bias in odds ratio estimates. A one-step approximation to the Savage-Dickey ratio will be presented as a Bayesian test for distributional assumptions in the traditional logistic regression model. The approximation utilizes least-squares estimates in the place of a full Bayesian Markov Chain simulation, and the equivalence of inferences based on the two implementations will be shown. A framework for flexible, semiparametric estimation of risks in the case that the assumption of logistic error is rejected will be proposed. A second application deals with regression scenarios in which residuals are correlated and their distribution evolves over an ordinal covariate such as time. In the context of prediction, such complex error distributions need to be modeled carefully and flexibly. The proposed model introduces dependent, but separate Polya tree priors for each time point, thus pooling information across time points to model gradual changes in distributional shapes. Theoretical properties of the proposed model will be outlined, and its potential predictive advantages in simulated scenarios and real data will be demonstrated.

As intra-industry trade increases in U.S. agricultural and food processing industries, the historical agricultural trade surplus is tightening. In efforts to maintain the trade surplus a focus has shifted towards the promotion of agricultural and processed food exports among small and medium sized firms. This study intends to identify and evaluate the potential for exports among small to medium sized agricultural and food processing firms in Kentucky through a collection of survey data. The objectives of this thesis are to identify the state’s product marketing opportunities and product specifications for international exports while identifying transaction requirements for potential exports. An analysis of the constraints and challenges faced by firms in the decision to export reveals rational behavior Binary logistic regression analysis is used to identify the impact of firm characteristics, perceived marketing conditions and information constraints, and financial aspects on a firm’s decision to export. A second logit regression analyzes the impact on a non-exporting firm’s interest in international marketing opportunities. The lack of international market information, financial constraints, and risk are found to be significant factors in the decision to export and interest in foreign marketing.

"Ginger Rogers did everything Fred Astaire did - only going backwards" Citatet används i flera litteraturer om returlogistik, detta för att ge uttryck åt den anspråkslösa betydelse returlogistik haft inom logistikvärlden, men som idag fått allt större betydelse. Uttrycket grundar sig i det rykte Fred Astaire hade, världens främste dansare. Vad som ofta kom i skymundan var prestationen från hans danspartner Ginger Rogers, trots att hon gjorde samma rörelser, fast baklänges och i högklackat. Det är enkelt, det är snabbt och du behöver inte trängas, fördelarna med e-handel är för konsumenten många, men hur påverkar denna utveckling företagen som bedriver butikerna? Handel av modevaror på internet har de senaste åren ökat markant, men det finns en problematik i att bedöma en produkt utifrån en bild, vilket är en bidragande faktor till att returer ökat avsevärt. Det finns många aktörer på marknaden och deras produktutbud är dessutom förhållandevis lika. Kunden kan därmed enkelt navigera mellan de olika e-handelsbutikerna, allt för att optimera sitt köp och göra en affär där det bästa erbjudandet erhålls. Frågan e-handelsbutikerna bör ställa sig är hur de kan differentiera sig på marknaden för att vara kundens första val. Då både konkurrens och rådande lagstiftning gör att e-handelsbutikerna erbjuder mer eller mindre generösa returregler, har de ett konstant flöde av varor som kommer i retur. Syftet med denna studie är att se hur e-handelsföretagen kan hantera dessa returer och framförallt hur de kan effektivisera sina processer för att minska returer, utan att förlora sina kunder och skada sitt varumärke. Genom en webbaserad enkätundersökning kunde författarna utläsa kundernas åsikter gällande e-handel av kläder och skor. Det framkom i undersökningen att kunderna värderar enkelhet högt och att de räknar med returer som en del av servicen, utan någon extra kostnad. För ett bredare perspektiv har även två intervjuer genomförts, en med ett företag verksam i branschen och en med en e-handelskonsult som arbetar strategiskt med olika e-handelsprojekt. Avslutningsvis menar författarna att e-handelsbutikerna är beroende av sina kunder men inte på bekostnad av deras överlevnad. Företagen bör istället möta sina kunder i olika kanaler och arbeta kontinuerligt med förebyggande åtgärder för att minimera antalet returer. E-handelsbutikerna är inte där idag, men de butiker som vågar ta initiativet att göra förändringar, kommer ha en plats på denna marknad i framtiden. / "Ginger Rogers did everything Fred Astaire did - only going backwards" This quote is used in several literatures about reverse logistic; in order to give expression to the modest significance reverse logistic has had in the logistic world, which today has become increasingly important. The quote has its origin in the reputation Fred Astaire had, the world’s greatest dancer. What often got overshadowed was the performance of his dancing partner Ginger Rogers, even though she did the same movements, but in reverse and in high heels. It’s simple, it’s fast and not crowded, the benefits of e-commerce are for the consumer numerous, but what impact does this has on the companies? Trade of fashion products online has, in recent years increased considerably, but assessing a product based on an image is a pronounced problem, which is a contributing aspect to why returns have increased in the same extent. There are many operators on this market and their product range is relatively equal. Due to this the consumers can easily navigate between e-commerce stores, all to optimize purchases that will fulfil their expectations and needs. The question e-commerce stores should be given is how they can differentiate themselves to be the customer’s first choice. The purpose of this study is to see how e-commerce companies can handle these returns, and especially how they can streamline their processes to reduce returns, without losing their customers and damaging their brand. Through a web-based survey the authors could interpret customer’s opinion regarding e-commerce of clothes and shoes. The outcome of the survey showed that customer value simplicity high but also expect returns as a part of the service, without any major expenses. For a broader perspective two interviews were conducted; one with a company operating on this market and one with an e-commerce consultant who is strategically working with various e-commerce projects.  In conclusion the authors argue that e-commerce stores are dependent on their customers, but not at the expense of its survival. They need to meet their customers in different channels and work preventive to minimize the number of returns. E-commerce stores are not yet there, but those stores that take the initiative to make changes will be an operator who will have a place on this market in the future.

Substance abuse is the overindulgence in and dependence on a drug or chemical leading to detrimental effects on the individual’s health and the welfare of those surrounding him or her. Logistic regression analysis is an important tool used in the analysis of the relationship between various explanatory variables and nominal response variables. The objective of this study is to use this statistical method to determine the factors which are considered to be significant contributors to the use or abuse of substances in school-aged children and also determine what measures can be implemented to minimize their effect. The logistic regression model was used to build models for the three main types of substances used in this study; Tobacco, Alcohol and Drugs and this facilitated the identification of the significant factors which seem to influence their use in children.

Differential item functioning (DIF) occurs when individuals from different groups who have equal levels of a latent trait fail to earn commensurate scores on a testing instrument. Type I error occurs when DIF-detection methods result in unbiased items being excluded from the test while a Type II error occurs when biased items remain on the test after DIF-detection methods have been employed. Both errors create potential issues of injustice amongst examinees and can result in costly and protracted legal action. The purpose of this research was to evaluate two methods for detecting DIF: logistic regression (LR) and Mantel-Haenszel (MH). To accomplish this, meta-analysis was employed to summarize Monte Carlo quantitative studies that used these methods in published and unpublished literature. The criteria employed for comparing these two methods were Type I error rates, the Type I error proportion, which was also the Type I error effect size measure, deviation scores, and power rates. Monte Carlo simulation studies meeting inclusion criteria, with typically 15 Type I error effect sizes per study, were compared to assess how the LR and MH statistical methods function to detect DIF. Studied variables included DIF magnitude, nature of DIF (uniform or non-uniform), number of DIF items, and test length. I found that MH was better at Type I error control while LR was better at controlling Type II error. This study also provides a valuable summary of existing DIF methods and a summary of the types of variables that have been manipulated in DIF simulation studies with LR and MH. Consequently, this meta-analysis can serve as a resource for practitioners to help them choose between LR and MH for DIF detection with regard to Type I and Type II error control, and can provide insight for parameter selection in the design of future Monte Carlo DIF studies.