Modeling the distribution of crossovers and interference with mice DNA data

Chiasma and crossover are two related biological processes of great importance in the understanding genetic variation. The study of these processes is straightforward in organisms where all products of meiosis are recovered and can be observed. This is not the case in mammals. Our understanding of these processes depends on our ability to model them. In this study I describe the biological processes that underline chiasma and crossover as well as the two main inference problems associated with these processes: i) in mammals we only recover one of the four products of meiosis and, ii) in general, we do not observe where the crossovers actually happen, but we find an interval containing type-2 censored information. NPML estimate was proposed and used in this work and used to compare chromosome length and chromosome expansion through the crosses.

Packings and coverings of the complete graph with trees

In this thesis, we define the spectrum problem for packings (coverings) of G to be the problem of finding all graphs H such that a maximum G-packing (minimum G- covering) of the complete graph with the leave (excess) graph H exists. The set of achievable leave (excess) graphs in G-packings (G-coverings) of the complete graph is called the spectrum of leave (excess) graphs for G. Then, we consider this problem for trees with up to five edges. We will prove that for any tree T with up to five edges, if the leave graph in a maximum T-packing of the complete graph Kn has i edges, then the spectrum of leave graphs for T is the set of all simple graphs with i edges. In fact, for these T and i and H any simple graph with i edges, we will construct a maximum T-packing of Kn with the leave graph H. We will also show that for any tree T with k ≤ 5 edges, if the excess graph in a minimum T-covering of the complete graph Kn has i edges, then the spectrum of excess graphs for T is the set of all simple graphs and multigraphs with i edges, except for the case that T is a 5-star, for which the graph formed by four multiple edges is not achievable when n = 12.

Toxic metal recovery from spent hydroprocessing catalyst

Spent hydroprocessing catalysts (HPCs) are solid wastes generated in refinery industries and typically contain various hazardous metals, such as Co, Ni, and Mo. These wastes cannot be discharged into the environment due to strict regulations and require proper treatment to remove the hazardous substances. Various options have been proposed and developed for spent catalysts treatment; however, hydrometallurgical processes are considered efficient, cost-effective and environmentally-friendly methods of metal extraction, and have been widely employed for different metal uptake from aqueous leachates of secondary materials. Although there are a large number of studies on hazardous metal extraction from aqueous solutions of various spent catalysts, little information is available on Co, Ni, and Mo removal from spent NiMo hydroprocessing catalysts. In the current study, a solvent extraction process was applied to the spent HPC to specifically remove Co, Ni, and Mo. The spent HPC is dissolved in an acid solution and then the metals are extracted using three different extractants, two of which were aminebased and one which was a quaternary ammonium salt. The main aim of this study was to develop a hydrometallurgical method to remove, and ultimately be able to recover, Co, Ni, and Mo from the spent HPCs produced at the petrochemical plant in Come By Chance, Newfoundland and Labrador. The specific objectives of the study were: (1) characterization of the spent catalyst and the acidic leachate, (2) identifying the most efficient leaching agent to dissolve the metals from the spent catalyst; (3) development of a solvent extraction procedure using the amine-based extractants Alamine308, Alamine336 and the quaternary ammonium salt, Aliquat336 in toluene to remove Co, Ni, and Mo from the spent catalyst; (4) selection of the best reagent for Co, Ni, and Mo extraction based on the required contact time, required extractant concentration, as well as organic:aqueous ratio; and (5) evaluation of the extraction conditions and optimization of the metal extraction process using the Design Expert® software. For the present study, a Central Composite Design (CCD) method was applied as the main method to design the experiments, evaluate the effect of each parameter, provide a statistical model, and optimize the extraction process. Three parameters were considered as the most significant factors affecting the process efficiency: (i) extractant concentration, (ii) the organic:aqueous ratio, and (iii) contact time. Metal extraction efficiencies were calculated based on ICP analysis of the pre- and post–leachates, and the process optimization was conducted with the aid of the Design Expert® software. The obtained results showed that Alamine308 can be considered to be the most effective and suitable extractant for spent HPC examined in the study. Alamine308 is capable of removing all three metals to the maximum amounts. Aliquat336 was found to be not as effective, especially for Ni extraction; however, it is able to separate all of these metals within the first 10 min, unlike Alamine336, which required more than 35 min to do so. Based on the results of this study, a cost-effective and environmentally-friendly solventextraction process was achieved to remove Co, Ni, and Mo from the spent HPCs in a short amount of time and with the low extractant concentration required. This method can be tested and implemented for other hazardous metals from other secondary materials as well. Further investigation may be required; however, the results of this study can be a guide for future research on similar metal extraction processes.

Perceptions of Social Supports and Services for Intimate Partner Violence Victims

Intimate partner violence (IPV) is a complex issue. The present study explored how media exposure to female and male victims of IPV affected participants’ support for both groups. It was hypothesized that female victims would be supported more than male victims and that presenting stimuli that drew attention to male victims would not decrease support for female victims. Participants were presented with one of three posters, drawing attention to male victims, female victims, or both. A questionnaire was then used to assess perceptions of support for IPV victims, which was completed by 121 participants. Results indicated that females were supported more than males and that drawing attention to male victims did not decrease participants’ support for female victims. An exploratory analysis also revealed that women, overall, have high support for all victims, while men’s level of support changed depending on the type of information to which they were exposed.

Crime and prejudice: The influence of appearance on blame amongst perpetrators and victims

Stereotypes based on characteristics such as age, race, and gender influence opinions in a criminal context. Yet, to date research has largely assessed whether perpetrators, rather than victims, are judged differently. Furthermore, although facial features can be a source of unconscious bias, research has failed to assess whether perceptions based on facial features affect the criminal context. To better understand the relationship between stereotypic facial features and gender, and whether this varies across perpetrators and victims, participants were asked to answer questions about an aggravated assault scenario after viewing an image of a person described as the victim or the alleged perpetrator. Images varied in gender and in presence or absence of tattoos or gothic makeup. Participants sympathized with the victim regardless of gender, but discrepancies were stronger if the victim was female than male. Neutral and tattooed faces were judged more harshly than faces with gothic makeup, regardless of gender.

Evaluating Public Knowledge of the NCRMD Defence

The not criminally responsible on account of mental disorder (NCRMD) defence is used when claims can be made that offenders are not responsible for their actions due to symptoms of a mental disorder. Bill C-14, now enacted in Canada, has implemented changes making it more difficult for NCRMD defendants to be released back into the public. This enactment appears to have been primarily due to public perceptions rather than actual knowledge of the defence. Thus it seems important to assess what members of the public actually know about the defence. To assess this, 127 participants completed a survey assessing their knowledge of the illnesses generally involved in the NCRMD defence, crimes committed, and punishments received. On average, only 31.6% of responses were answered within 20% of the factual statistics. Results suggest a general lack of knowledge about the defence and demonstrate why important changes should be based on factual information rather than public opinion.

Effect of Experience on Alibi Generation and Expectation

Members of the general population have high expectations of people who are asked to corroborate an alibi for the suspect of a crime. The general belief is that it is easy to provide an alibi if a person is innocent, and therefore guilt should be assumed when an alibi cannot be provided. The possibility that having to generate an alibi oneself could influence expectations was examined. Additionally, potential changes in opinion after being provided with positive or negative feedback were explored. Results showed a significant difference in expectations based on whether participants were correct or incorrect in identifying the suspect, that is, whether participants were able to provide an alibi. Those who were incorrect had lower expectations of themselves and of others than those who were correct. Making jurors aware of the difficulty in providing an alibi may lead to fairer treatment of suspects who have difficulty providing one.

Exploring the Role of Parental Hearsay when Children Witness a Crime

In cases of potential child abuse, parents may provide hearsay testimony on behalf of a child, retelling events from the child’s perspective. However, according to the limited research that exists, parents may have a negative impact on their child’s memory of an event (Principe, DiPuppo, & Gammel, 2013). In order to gain a better understanding of parental hearsay, parents’ descriptions of information children provided in recorded parent-child discussions were compared to the actual information the children provided in the initial discussion and in a 1-week follow-up interview. Children interviewed by parents were also compared to children interviewed by a trained interviewer. To date, 11 children between the ages of 6-9 years have been assessed. While the current sample size was too small to yield many significant results, graphs and effect sizes suggest there are differences in memory accuracy and completeness between parents and children and across children’s interview condition. Whether hearsay testimony or children’s testimony is preferable may depend on how suggestive the initial parent-child discussion is.

The Self as a Moral Basis: Do Our Own Patterns of Behavior Affect our Moral Attributions?

To determine which actions are morally acceptable, psychologists typically focus on decision making within existing moral paradigms. However, this fails to comment upon individual and social processes, such as attribution, that determine morality. To address these processes, this study had participants respond to morally-charged scenarios by rating the immorality of an actor who did not tip a waiter (n = 125), was partial to infidelity (n = 128), and texted while driving (n = 128). Participants also completed an empathy measure, and provided their own frequency of engaging in certain behaviors, including those featured in the scenarios. Immorality ratings were compared to the participants’ own frequency of the scenario action (hypothesized to lower ratings), as well as empathy and outcome severity (both hypothesized to increase ratings). Findings were assessed in three regressions, one per scenario. Behavioral similarity predicted immorality ratings in each (p ≤ .03), empathy predicted ratings only for not tipping a waiter (p = .04), while outcome severity was un-predictive in each scenario. Theoretical implications, directions for future research, and limitations of the study are discussed.

Lie detection and children: Impact of the mode of presentation

Although a great deal of research has examined lie-detection among adults, little research has examined the differences between audio and visual mediums for deception among children. In the current study participants were presented (n = 42) with recordings of four children, each describing his/her experience of getting glasses. Two of the accounts were truthful, two were fabricated. Half of the participants were presented with videos, half were presented with audio-recordings. Following the presentation of each recording, participants responded to questions regarding the truthfulness of each child’s account. Results showed that when evaluating truth-tellers, participants’ lie-detection accuracy was significantly greater than chance. Within the video condition, non-parents were shown to report significantly more lie-related cues than parents. Several deception cues were shown to be related to lie-detection accuracy.

Greener Alternatives to Selected Organic Oxidation Reactions

The study of green chemistry is dedicated to eliminating or reducing toxic waste. One route to accomplish this goal is to explore alternative reaction conditions and parameters resulting in the development of more benign synthetic routes and reagents. The primary focus of this research is to find optimal reaction conditions for the oxidation of a primary alcohol to an aldehyde. As a case study, the oxidation of benzyl alcohol to benzaldehyde, a common industrial process, was examined. Traditionally carried out using the Jones Reagent, commonly referred to as chromium (IV) oxide or chromium trioxide (CrO3) in sulphuric acid, a great deal of research went into utilizing less toxic reagents, such as MnO2 or KMnO4 supported on a clay base. This research has led to an improvement on these alternatives, using a lithium chloride (LiCl) catalyst in a montmorillonite K10 clay solid phase, together with the oxidizing agent hydrogen peroxide, as even greener alternatives to these traditional oxidizing agents. Experiments were carried out to determine the lifetime of this LiCl/clay system as compared to MnO2 and KMnO4, to investigate its ability to catalyze the oxidation of other aromatic alcohols (such as 4-methoxybenzyl alcohol and diphenylmethanol), and to further improve the system’s adherence to green chemistry principles. Green solvent alternatives were examined by replacing the toluene solvent with dimethylcarbonate (DMC), and reaction conditions were optimized to improve product yield. It was determined that the LiCl/H2O2 system was, in most cases, equally as effective at catalyzing the oxidation of benzyl alcohol to benzaldehyde. Although the catalyst and oxidizing agent eliminated the toxic waste generated from chromium reagents, it offered significant challenges in product isolation, because of an aqueous-organic phase separation.

Modelling the growth of Northern Cod

We develop a body size growth model of Northern cod (Gadus morhua) in Northwest Atlantic Fisheries Organization (NAFO) Divisions 2J3KL during 2009-2013. We use individual length-at-age data from the bottom trawl survey in these divisions during 2009–2013. We use the Von Bertalanffy (VonB) model extended to account for between-individual variations in growth, and variations that may be caused by the methods which fish are caught and sampled for length and age measurements. We assume between-individual variation in growth appears because individuals grow at a different rate (k), and they achieve different maximum sizes (l∞). We also included measurement error in length and age in our model since ignoring these errors can lead to biased estimates of the growth parameters. We use the structural errors-invariables (SEV) approach to estimate individual variation in growth, ageing error variation, and the true age distribution of the fish. Our results shows the existence of individual variation in growth and ME in age. According to the negative log likelihood ratio (NLLR) test, the best model indicated: 1) different growth patterns across divisions and years. 2) Between individual variation in growth is the same for the same division across years. 3) The ME in age and true age distribution are different for each year and division.

Exploring the Process of Meaning-making after Partner Suicide

Meaning-making is increasingly recognized as a fundamental aspect of the grief experience. This study investigated the process of meaning-making in the narratives of individuals whose partners died by suicide, exploring their meaning reconstruction in response to this form of loss. The narratives of users of a public online grief support forum (n = 50) were analyzed using the Meaning of Loss Codebook (Gillies, Neimeyer, & Milman, 2014), which consists of core categories of meaning of loss in response to the death of a loved one. The results indicated that these individuals predominantly experienced negative affect, a lack of understanding associated with the loss, and a longing for their partners. The grief experience of participants in this study was marked by substantial psychological distress and an ongoing struggle to make sense of and find meaning in this type of loss. It is clear that grieving the loss of a partner as a result of suicide presents unique challenges to meaning-making in comparison to other types of loss. Given the importance of this aspect of adjustment to loss, these findings deepen the understanding of this component of grief and inform the provision of support for those grieving a loved one who died by suicide.

MINDREADING: INTROVERSION VERSUS EXTRAVERSION

Theory of mind (also called ‘mindreading’), is the ability to explain and predict others’ behaviour by inferring their mental states, such as their knowledge, beliefs, perceptions and desires. One largely unexplored question in theory of mind research is the relationship between personality and theory of mind abilities in adults. The current study investigated introverts’ and extraverts’ performance on two theory of mind tasks: one task involved judging emotional states from pictures of eyes (RMTE task), and the other involved making judgments about one’s own and others’ visual perspective (AVP task). In both tasks, the personal relevance of the situation was varied to examine whether this factor would differentially affect the performance of introverts and extraverts. There was a significant interaction between personality (introvert vs. extravert) and condition (personal vs. impersonal) in the AVP task, with extraverts performing better in the personal than in the impersonal condition but introverts performing the same in both conditions. In the RMTE task there was no interaction, as all participants performed better in the personal condition regardless of personality. There was also a main effect of personality in the RMTE, with introverts performing better overall than extraverts at judging emotions from eyes. Possible reasons behind these and other observed differences are discussed.