Causality in crude oil prices

Crude oil markets witness growing disparity between the quality of crudes supplied and demanded in the market. The market share of low-quality crudes is increasing due to the depletion of old fields and increasing demand. This is unnerving the practitioners and affecting the relevance of the traditional benchmark crudes due to the lack of lower quality benchmarks (Montepeque, 2005). In this article, we apply Granger causality tests to study the price dependence of 32 crudes in order to establish which crudes drive other prices and which ones simply follow general market trends. Our results indicate that some of the old benchmarks are still relevant while others can be disregarded. Our results also interestingly show that the low-quality Mediterranean Russian Urals crude, introduced in the late 1990s, has emerged recently as a significant driver of global prices. © 2011 Taylor & Francis.

Potential causes of ethnic group disparities in infertility:a hospital database study

Introduction - Lower success rates of in vitro fertilisation (IVF) in South East Asian countries compared to Western countries in informal studies and surveys was considered a reflection of variations in methodology and expertise. However, recent studies on the effects of ethnicity on success rates of infertility procedures in western countries have suggested other inherent contributing factors to the ethnic disparity but the evidence evaluating these is lacking. In our study we aim to investigate some of the comorbidities that might cause ethnic disparity to infertility and related procedures from hospital admissions data. Methods - Anonymous hospital admissions data on patients of various ethnic groups with infertility, comorbidities and infertility procedures from multiple hospitals in Birmingham andManchester, UK between 2000 and 2013 were obtained from the local health authority computerised hospital activity analysis register using ICD-10 and OPCS coding systems. Statistical analysis was performed using SPSS version 20.Results Of 522 223 female patients aged 18 and over, there were44 758 (8.4%) patients from South Asian (SA) community. 1156(13.4%) of the 8653 patients coded for infertility were SA, whichis a considerably higher proportion of the background SA population. For IVF procedures, the percentage of SA increased to15.4% (233 of the total 1479 patients). The mean age of SA codedfor infertility (30.6 ± 4.7 SD years versus 32.8 ± 4.9 SD years)and IVF (30.4 ± 4.3 SD years versus 32.7 ± 4.4 SD years) was significantly lower than caucasian patien ts (P < 0.001). A multivariate logistic regression model looking at patients with infertility, accounting for variations in age, showed that SA have significantly higher prevalence of hypothyroidism, obesity andiron-deficiency anaemia compared to caucasians but lower prevalence of endometriosis. Interestingly, psychiatric and psychological conditions diagnoses were seldom registered in infertility patients. Conclusion - Other studies suggest that various cultural, lifestyles, psychosocial and socio-economic factors may explain the disparities in IVF success rates between South Asians and caucasians. The fact that SA infertility and IVF patients, in ou rstudy, were significantly younger than caucasians and that their proportion is considerably higher than the background South Asian population suggests the influence of these factors. A significant psychiatric disease burden in other conditions and low numbers in our data suggest under diagnosis in this group.Despite the limitations of the coding data, from our study, we propose that hypothyroidism, obesity and/or iron-deficiency anaemia should be considered for the ethnic disparity. Further research in this topic is essential to fully investigate the reasons for such ethnic disparities.

Early spatial vision:a view through two eyes

Simple features such as edges are the building blocks of spatial vision, and so I ask: how arevisual features and their properties (location, blur and contrast) derived from the responses ofspatial filters in early vision; how are these elementary visual signals combined across the twoeyes; and when are they not combined? Our psychophysical evidence from blur-matchingexperiments strongly supports a model in which edges are found at the spatial peaks ofresponse of odd-symmetric receptive fields (gradient operators), and their blur B is givenby the spatial scale of the most active operator. This model can explain some surprisingaspects of blur perception: edges look sharper when they are low contrast, and when theirlength is made shorter. Our experiments on binocular fusion of blurred edges show that singlevision is maintained for disparities up to about 2.5*B, followed by diplopia or suppression ofone edge at larger disparities. Edges of opposite polarity never fuse. Fusion may be served bybinocular combination of monocular gradient operators, but that combination - involvingbinocular summation and interocular suppression - is not completely understood.In particular, linear summation (supported by psychophysical and physiological evidence)predicts that fused edges should look more blurred with increasing disparity (up to 2.5*B),but results surprisingly show that edge blur appears constant across all disparities, whetherfused or diplopic. Finally, when edges of very different blur are shown to the left and righteyes fusion may not occur, but perceived blur is not simply given by the sharper edge, nor bythe higher contrast. Instead, it is the ratio of contrast to blur that matters: the edge with theAbstracts 1237steeper gradient dominates perception. The early stages of binocular spatial vision speak thelanguage of luminance gradients.

Binocular summation, binocular fusion and the transition to diplopia

The visual system combines spatial signals from the two eyes to achieve single vision. But if binocular disparity is too large, this perceptual fusion gives way to diplopia. We studied and modelled the processes underlying fusion and the transition to diplopia. The likely basis for fusion is linear summation of inputs onto binocular cortical cells. Previous studies of perceived position, contrast matching and contrast discrimination imply the computation of a dynamicallyweighted sum, where the weights vary with relative contrast. For gratings, perceived contrast was almost constant across all disparities, and this can be modelled by allowing the ocular weights to increase with disparity (Zhou, Georgeson & Hess, 2014). However, when a single Gaussian-blurred edge was shown to each eye perceived blur was invariant with disparity (Georgeson & Wallis, ECVP 2012) – not consistent with linear summation (which predicts that perceived blur increases with disparity). This blur constancy is consistent with a multiplicative form of combination (the contrast-weighted geometric mean) but that is hard to reconcile with the evidence favouring linear combination. We describe a 2-stage spatial filtering model with linear binocular combination and suggest that nonlinear output transduction (eg. ‘half-squaring’) at each stage may account for the blur constancy.

Preimplantation genetic diagnosis: Analysis of gene expression, nuclear DNA and cytoplasmic DNA

Preimplantation genetic diagnosis (PGD) following in vitro fertilization (IVF) offers couples at risk for transmitting genetic disorders the opportunity to identify affected embryos prior to replacement. In particular, embryo gender determination permits screening for X-linked diseases of unknown etiology. Analysis of embryos can be performed by polymerase chain reaction (PCR) amplification of material obtained by micromanipulation. This approach provides an alternative to the termination of an established pregnancy following chorionic villi sampling or amniocentesis. ^ Lately, the focus of preimplantation diagnosis and intervention has been shifting toward an attempt to correct cytoplasmic deficiencies. Accordingly, it is the aim of this investigation to develop methods to permit the examination of single cells or components thereof for clinical evaluation. In an attempt to lay the groundwork for precise therapeutic intervention for age related aneuploidy, transcripts encoding proteins believed to be involved in the proper segregation of chromosomes during human oocyte maturation were examined and quantified. Following fluorescent rapid cycle RT-PCR analysis it was determined that the concentration of cell cycle checkpoint gene transcripts decreases significantly as maternal age increases. Given the well established link between increasing maternal age and the incidence of aneuploidy, these results suggest that the degradation of these messages in aging oocytes may be involved with inappropriate chromosome separation during meiosis. ^ In order to investigate the cause of embryonic rescue observed following clinical cytoplasmic transfer procedures and with the objective of developing a diagnostic tool, mtDNA concentrations in polar bodies and subcellular components were evaluated. First, the typical concentration of mtDNA in human and mouse oocytes was determined by fluorescent rapid cycle PCR. Some disparity was noted between the copy numbers of individual cytoplasmic samples which may limit the use of the current methodology for the clinical assessment of the corresponding oocyte. ^

Three essays on trade and investment

From H. G. Johnson's work (Review of Economic Studies, 1953–54) on tariff retaliation, the questions of whether a country can win a “tariff war” and how or even the broader question of what will affect a country's strategic position in setting bilateral tariff have been tackled in various situations. Although it is widely accepted that a country will have strategic advantages in winning the tariff war if its relative monopoly power is sufficiently large, it is unclear what are the forces behind such power formation. The goal of this research is to provide a unified framework and discuss various forces such as relative country size, absolute advantages and relative advantages simultaneously. In a two-country continuum-of-commodity neoclassical trade model, it is shown that sufficiently large relative country size is a sufficient condition for a country to choose a non-cooperative tariff Nash equilibrium over free trade. It is also shown that technology disparities such as absolute advantage, rate of technology disparity and the distribution of the technology disparity all contribute to a country's strategic position and interact with country size. ^ Leverage effect is usually used to explain the phenomenon of asymmetric volatility in equity returns. However, leverage itself can only account for parts of the asymmetry. In this research, it is shown that stock return volatility is related to firms’ financial status. Financially constrained firms tend to be more sensitive to the return changes. Financial constraint factor explains why some firms tend to be more volatile than others. I found that the financial constraint factor explains the stock return volatility independent of other factors such as firm size, industry affiliation and leverage. Firms’ industry affiliations are shown to be very weak in differentiating volatility. Firm size is proven to be a good factor in distinguishing the different levels of volatility and volatility-return sensitivity. Leverage hypothesis is also partly corroborated and the situation where leverage effect is not applicable is discussed. Finally, I examined the macroeconomic policy's effects on overall market volatility. ^

Comparison of snail density, standing stock, and body size between Caribbean karst wetlands and other freshwater ecosystems

Synthesizing data from multiple studies generates hypotheses about factors that affect the distribution and abundance of species among ecosystems. Snails are dominant herbivores in many freshwater ecosystems, but there is no comprehensive review of snail density, standing stock, or body size among freshwater ecosystems. We compile data on snail density and standing stock, estimate body size with their quotient, and discuss the major pattern that emerges. We report data from 215 freshwater ecosystems taken from 88 studies that we placed into nine categories. Sixty-five studies reported density, seven reported standing stock, and 16 reported both. Despite the breadth of studies, spatial and temporal sampling scales were limited. Researchers used 25 different sampling devices ranging in area from 0.0015 to 2.5 m2. Most ecosystem categories had similar snail densities, standing stocks, and body sizes suggesting snails shared a similar function among ecosystems. Caribbean karst wetlands were a striking exception with much lower density and standing stock, but large body size. Disparity in body size results from the presence of ampullariids in Caribbean karst wetlands suggesting that biogeography affects the distribution of taxa, and in this case size, among aquatic ecosystems. We propose that resource quality explains the disparity in density and standing stock between Caribbean karst wetlands and other categories. Periphyton in Caribbean karst wetlands has high carbon-to-phosphorous ratios and defensive characteristics that inhibit grazers. Unlike many freshwater ecosystems where snails are key grazers, we hypothesize that a microbial loop captures much of the primary production in Caribbean karst wetlands.

An analysis of the factors that influence regional economic development cooperation

This dissertation is a comparative case study of regional cooperation in the field of economic development. In the 21st century global economy, proponents of regionalism have put forth fresh arguments for collective action. A regional approach to economic development activity presents a classic social dilemma: How can local officials collectively improve the economic prospects of a region, and remain autonomous to act in the best interest of the local community? This research examines the role of social capital in overcoming this social dilemma. ^ Three (3) comparable Metropolitan Statistical Areas (MSAs) form the empirical basis of this research. The Houston MSA, the Atlanta MSA and the Miami MSA present distinct variations of regionalized economic development activity. This dissertation seeks to explain this disparity in the dependent variable. The hypothesis is that accrued social capital is crucial to obtaining economic development cooperative agreements.^ This qualitative research utilized secondary demographic and economic databases, survey instruments, interviews, field observations, and a review of legislative and administrative decisions to formulate a clear understanding of the factors influencing the current state of regional economic development cooperation within each region. The study concludes that the legislative and executive decisions of state government exert inordinate influence on the capacity of local officials to cooperate regionally for economic development purposes.^

Comparison of two mentoring programs for at -risk Black adolescents: A traditional one -to -one mentoring program and a school -to -work transitional program

The purposes of this study were: (a) to compare the impact of One-to-One (OTO) mentoring interventions administered in the high school setting, and the workplace of the students who participated in the School-to-Work (STW) transitional program, and (b) to identify how the participants perceived their experience in the OTO mentoring program and the STW transitional program. A qualitative approach was used to identify how participants perceived their mentoring experiences with the STW and OTO mentoring programs by utilizing focus groups and content analysis. A quantitative approach was used to compare the statistical differences of outcomes between the STW and OTO mentoring programs, by utilizing descriptive statistics, independent samples t-tests, chi-square analyses, and logistic regression. The sample was limited to participants in the STW and OTO mentoring programs resulting in 21 participants for the qualitative approach and 114 participants for the quantitative approach. ^ Results from the qualitative approach indicated that focus group participants in the STW program were satisfied with the program and the relationship with their mentors. They also suggested that the STW program be lengthened to include the entire academic year. Participants from the OTO focus group were dissatisfied with their program due to inadequate mentor involvement. Results from the quantitative approach showed that the increase in school attendance for the STW program's at-risk Black male youth was statistically significant compared to the OTO program participants; the STW program participants displayed a better outlook for attending college that was statistically significant compared to those in the OTO program; and the OTO program participants displayed a better outlook for permanent employment compared to those in the STW program. ^ Therefore, this study finds that mentoring can contribute to reducing school absences and high school completion in order for at-risk Black adolescents to attend college. It is recommended that the OTO program be restructured to eliminate the disparity that exists regarding the administration of the STW program and the OTO program. ^

A multimodal and adaptive real-time human -computer interface for peoples with severe motor disability

This dissertation introduces the design of a multimodal, adaptive real-time assistive system as an alternate human computer interface that can be used by individuals with severe motor disabilities. The proposed design is based on the integration of a remote eye-gaze tracking system, voice recognition software, and a virtual keyboard. The methodology relies on a user profile that customizes eye gaze tracking using neural networks. The user profiling feature facilitates the notion of universal access to computing resources for a wide range of applications such as web browsing, email, word processing and editing. ^ The study is significant in terms of the integration of key algorithms to yield an adaptable and multimodal interface. The contributions of this dissertation stem from the following accomplishments: (a) establishment of the data transport mechanism between the eye-gaze system and the host computer yielding to a significantly low failure rate of 0.9%; (b) accurate translation of eye data into cursor movement through congregate steps which conclude with calibrated cursor coordinates using an improved conversion function; resulting in an average reduction of 70% of the disparity between the point of gaze and the actual position of the mouse cursor, compared with initial findings; (c) use of both a moving average and a trained neural network in order to minimize the jitter of the mouse cursor, which yield an average jittering reduction of 35%; (d) introduction of a new mathematical methodology to measure the degree of jittering of the mouse trajectory; (e) embedding an onscreen keyboard to facilitate text entry, and a graphical interface that is used to generate user profiles for system adaptability. ^ The adaptability nature of the interface is achieved through the establishment of user profiles, which may contain the jittering and voice characteristics of a particular user as well as a customized list of the most commonly used words ordered according to the user's preferences: in alphabetical or statistical order. This allows the system to successfully provide the capability of interacting with a computer. Every time any of the sub-system is retrained, the accuracy of the interface response improves even more. ^

Network construction and graph theoretical analysis of functional language networks in pediatric epilepsy

This dissertation introduces a new approach for assessing the effects of pediatric epilepsy on the language connectome. Two novel data-driven network construction approaches are presented. These methods rely on connecting different brain regions using either extent or intensity of language related activations as identified by independent component analysis of fMRI data. An auditory description decision task (ADDT) paradigm was used to activate the language network for 29 patients and 30 controls recruited from three major pediatric hospitals. Empirical evaluations illustrated that pediatric epilepsy can cause, or is associated with, a network efficiency reduction. Patients showed a propensity to inefficiently employ the whole brain network to perform the ADDT language task; on the contrary, controls seemed to efficiently use smaller segregated network components to achieve the same task. To explain the causes of the decreased efficiency, graph theoretical analysis was carried out. The analysis revealed no substantial global network feature differences between the patient and control groups. It also showed that for both subject groups the language network exhibited small-world characteristics; however, the patient's extent of activation network showed a tendency towards more random networks. It was also shown that the intensity of activation network displayed ipsilateral hub reorganization on the local level. The left hemispheric hubs displayed greater centrality values for patients, whereas the right hemispheric hubs displayed greater centrality values for controls. This hub hemispheric disparity was not correlated with a right atypical language laterality found in six patients. Finally it was shown that a multi-level unsupervised clustering scheme based on self-organizing maps, a type of artificial neural network, and k-means was able to fairly and blindly separate the subjects into their respective patient or control groups. The clustering was initiated using the local nodal centrality measurements only. Compared to the extent of activation network, the intensity of activation network clustering demonstrated better precision. This outcome supports the assertion that the local centrality differences presented by the intensity of activation network can be associated with focal epilepsy.^

Perceptions and experiences of intimate partner violence among Hispanic college students

Intimate partner violence (IPV) is recognized as a serious, growing problem on college campuses. IPV rates among college students exceed estimates reported for the general population. Few studies have examined the impact of IPV among the Hispanic college student (HCS) population or explored how HCSs perceive and experience IPV. Focusing on young adults (ages 18 to 25 years), this mixed methods study was designed to explore the perceptions and experiences of IPV focusing on levels of victimization and perpetration in relation to gender role attitudes and beliefs, exposure to parental IPV, acculturation, and religiosity. A sample of 120 HCSs was recruited from two south Florida universities. A subsample of 20 participants was randomly selected to provide qualitative responses. All participants completed a series of questionnaires including a demographic survey, the FPB, CTS2-CA, SASH, ERS and CTS2. Bivariate correlational techniques and multiple regressions were used to analyze data. Marked discrepancy between participants' perceived experience of IPV (N = 120) and their CTS2 responses (n = 116, 96.7%). Only 5% of the participants saw themselves as victims or perpetrators of IPV, yet 66% were victims or 67% were perpetrators of verbal aggression; and 31% were victims or 32.5% were perpetrators of sexual coercion based on their CTS2 scores. Qualitative responses elicited from the subsample of 20 students provided some insight regarding this disparity. There was rejection of traditional stratified gender roles. Few participants indicated that they were religious (20.8%, n = 25). Evidence for the theory of intergenerational transmission of violence was noted. Recall of parental IPV was a significant predictor of level of IPV victimization (β = 0.177, SE = 0.85, p = 0.041). Nursing and social service providers must be cognizant that contributing factors to either victimization and/or perpetration of IPV among college students must be addressed first (i.e., perceptions of IPV), both in acute (i.e., emergency department) and community (i.e., college and university) settings for optimum intervention outcome.

The decolonization of Northwest Community College

In 1996, the authors of the Canadian Royal Commission on Aboriginal Peoples concluded Canadian educational policy had been based on the false assumption of the superiority of European worldviews. The report authors recommended the transformation of curriculum and schools to recognize that European knowledge was not universal. Aboriginal researcher Battiste believes the current system of Canadian education causes Aboriginal children to face cognitive imperialism and cognitive assimilation and that this current practice of cultural racism in Canada makes educational institutions a hostile environment for Aboriginal learners. In order to counter this cultural racism, Battiste calls for the decolonization of education. ^ In 2005, the president of Northwest Community College (NWCC), publicly committed to decolonizing the college in order to address the continuing disparity in educational attainment between Aboriginal and non-Aboriginal learners. Upon the president’s departure in 2010, the employees of NWCC were left to define for themselves the meaning of decolonization. ^ This qualitative study was designed to build a NWCC definition of colonization and decolonization by collecting researcher observations, nine weeks of participant blog postings, and pre and post blog Word survey responses drawn from a purposeful sample of six Aboriginal and six non-Aboriginal NWCC employees selected from staff, instructor and administrator employee groups. The findings revealed NWCC employees held multiple definitions of colonization and decolonization which did not vary between employee groups, or based on participant gender; however, differences were found based on whether the participants were Aboriginal or non-Aboriginal. ^ Both Aboriginal and non-Aboriginal participants thought decolonization was a worthy goal for the college. Aboriginal participants felt hopeful that decolonization would happen in the future and thought decolonization had to do with moving forward to a time when they would be valued, respected, empowered, unashamed, safe, and viewed as equal to non-Aboriginals. Non-Aboriginal participants were unsure if decolonization was possible because it would require going back in time to restore the Aboriginal way of life. When non-Aboriginal participants felt their thoughts were not being valued or they were being associated with colonialism, they felt angry and guarded and were uncomfortable with Aboriginal participants expressing anger towards Colonizers.^

A responsabilidade enunciativa na sentença judicial condenatória

The Textual Analysis of Discourse has its origin in Text Linguistics and it aims at studying the co(n)text meaning production based on the analysis of concrete texts by offering elements to the understanding of the text as a discourse practice throughout the plans or levels of linguistic analysis. In this perspective, we intend to investigate the enunciative responsibility phenomenon in the sentencing court judgment. To do so, we review the theoretical contributions of Textual Analysis of Discourse (ADAM, 2011) and the Enunciative Linguistics from various authors, among them, Rabatel (1998, 2003, 2004, 2005, 2008, 2009, 2010), Nølke (2001, 2005, 2009, 2013), Nølke, Fløttum and Norén (2004), Guentchéva (1994, 1996) and Guentchéva et al. (1994). In this direction, we investigate the enunciative responsibility through a range that comprises the phenomenon from four gradations, each one with a kind of point of view (PoV) and with links that may mark the assumption or the distance from the point of view. Regarding the legal approach of the thesis, our theoretical anchoring follows several authors, among them, Petri (1994), Soto (2001), Alvarez (2002), Alves (2003), Cornu (2005), Albi (2007), Bittar (2010), Asensio and Polanco (2011), López Samaniego (2006), López Montolío and Samaniego (2008), Montolío (2002, 2010, 2011, 2012, 2013), Sterling (2010), Prieto (2013), Lawrence and Rodrigues (2013) and Rodrigues, Passeggi and Silva Neto (2014). Our corpus is composed of 13 sentences from criminal cases arising from the district of Currais Novos-RN, completed in 2012. The results reveal how the judge, from various enunciative instances, builds the court decision, which allowed us to understand the configuration of (non) assumption of enunciative responsibility in the sentencing court judgment discourse genre. In conclusion, we perceive that the discourse units are envisaged or through the assumption, or the non assumption of PoV by the enunciative instances, what guides the producer organization argumentative text and his (her) communicative purposes. With that, the judge creates and/or modifies values and beliefs, induces and/or guides his (her) interlocutor by being able to demonstrate objectivity and/or preventing his (her) face through the mediated constructions or engage through the assumption of the enunciative responsibility of the propositional content of an utterance. In short, we reaffirm our belief that the (non) assumption of the enunciative responsibility configures as an argumentative mechanism strongly marked by the producer of the text with a view to their communicative purposes. The sentence, therefore, is constructed in this game of taking and/or not taking of statements according to argumentative orientation and the objectives of the text producer.

Desenvolvimento regional: um debate sobre as políticas industriais no Rio Grande do Norte

The discussion of economic development emphasizes the emergence of a gradual change of economic structure, which would rise from an agrarian to the industrial stage, and later with a predominant tertiary sector. However, the high Brazilian regional inequality resulted in the coexistence of modern spaces and other arrears. Such disparities are visible not only in economics, but spatial, social and environmental. Although Brazil has gone through changes in the production structure and the location of these activities, space - territorial disparities manifest themselves in a high level of regional heterogeneity. In this context, the Northeast emerged as a region that has historically been characterized by socioeconomic backwardness and the presence of the worst indicators of inequality. The presence of these indicators showing the socioeconomic backwardness of the other fronts region contributes to the priority of action aimed at reverting this regional disparity public policy. The historical account of the development policies of regional studies shows that the state played a pivotal role in ensuring regional planning. Besides the creation of development agencies such as the Northeast Sudene, tax and financial incentives have been widely used strategies in the region to foster greater national integration. However, the use of incentives is much discussed in view of the possible advantages and disadvantages brought by its use. Thus, this study aims to build a theoretical framework tool for building effective public policies for industrialization in the Northeast, specifically in Rio Grande do Norte.