Uniform Mixing and Association Schemes

We consider continuous-time quantum walks on distance-regular graphs of small diameter. Using results about the existence of complex Hadamard matrices in association schemes, we determine which of these graphs have quantum walks that admit uniform mixing. First we apply a result due to Chan to show that the only strongly regular graphs that admit instantaneous uniform mixing are the Paley graph of order nine and certain graphs corresponding to regular symmetric Hadamard matrices with constant diagonal. Next we prove that if uniform mixing occurs on a bipartite graph X with n vertices, then n is divisible by four. We also prove that if X is bipartite and regular, then n is the sum of two integer squares. Our work on bipartite graphs implies that uniform mixing does not occur on C_{2m} for m >= 3. Using a result of Haagerup, we show that uniform mixing does not occur on C_p for any prime p such that p >= 5. In contrast to this result, we see that epsilon-uniform mixing occurs on C_p for all primes p.Comment: 23 page

Climate Change\u27s Free Rider Problem: Why We Must Relinquish Freedom to Become Free

Despite the increasing urgency of climate change, countries continue to struggle to cooperate on even modest solutions. Of international accords that are successfully ratified, agreed-upon commitments are mostly hortatory and vague, succeeding only in engendering a fragmented, voluntary compliance scheme. Unsurprisingly, decades of tepid climate action and procrastination have begotten a staggering emissions gap for the world to close by 2030—requiring a collective greenhouse gas reduction of about fifty percent to limit global warming to the 1.5°C benchmark. Yet, global greenhouse emissions have generally risen, not fallen in the last decade, with 2018 marking a record high despite pledges made in compliance with the celebrated 2015 Paris Agreement. In short, international models of climate cooperation thus far have descriptively been unequal to the task of securing adequate global climate action. Once we recognize and agree that global warming cannot go unaddressed, the conclusion follows that change, perhaps of a radical nature, is required. This Article argues that decades of insufficient international cooperation militate against tweaking current models, and instead proposes a blueprint for a concrete, market-driven compliance scheme that, importantly, would be operative without a world government or divestment of individual sovereignty

Stress, Social Problem Solving, and Irritable Bowel Syndrome: A Cross-Lagged Panel Design Investigation of Interactive Influences

The current study examined the interplay of three key variables: stress, maladaptive social problem-solving (SPS), and Irritable Bowel Syndrome (IBS) symptom severity. According to SPS theory, SPS is the self-directed cognitive and behavioral process by which individuals attempt to manage real-life problems or stressful situations. There are two main types of SPS: adaptive or maladaptive (D’Zurilla & Chang, 1995). Individuals who have adaptive SPS tendencies tend to view problems in an optimistic light; they perceive problems as solvable challenges and opportunities for personal growth. On the other hand, individuals who have maladaptive SPS tendencies often see problems as threatening and unsolvable, and they generally exhibit an impulsive or careless problem-solving style, or an avoidant style such as ignoring problems. D’Zurilla and Nezu (2001) assert that the connection among stress, SPS, and adjustment is best understood by examining their relational/problem-solving model of stress and wellbeing. The relational/problem-solving model of stress and wellbeing suggests that risk factors such as increased stress or problems, maladaptive problem-solving ability, and decreased wellbeing form transactional relationships that interact with one another and evolve with time (D’Zurilla & Nezu, 2001). This model has been supported by a substantial number of studies that demonstrate links between maladaptive SPS and a wide range of psychological problems such as depression and anxiety (Anderson et al., 2009; Chang & D’Zurilla, 1996; Kant et al., 1997; Siu & Shek, 2010; Wilson, Bushnell, Rickwood, Caputi, & Thomas, 2011) and physical health problems such as non-cardiac chest pain, asthma, and migraines (Eskin et al., 2013; Nezu, Nezu, & Jain, 2008; Witty, Heppner, Bernard, & Thoreson, 2001). Although the relational/problem-solving model of wellbeing has been tested with several psychological and physical health problems, it had yet to be tested with IBS, which is one of the most common disorders diagnosed in primary care and gastroenterology settings (Mayer, 2008). IBS is characterized by a cluster of potentially debilitating symptoms that can include chronic abdominal pain and cramping, bloating, gas, irregular bowel patterns (i.e., diarrhea, constipation, or watery stools), and uncomfortable sensations of incomplete evacuation. IBS has no clear etiology or mechanism to explain dysfunction, but the biopsychosocial perspective is the predominant approach for understanding IBS (Kennedy et al., 2012; Tanaka et al., 2011). The biopsychosocial perspective links biological, psychological, and social factors to the onset, severity, and course of IBS (Pletikosić & Tkalčić, 2013; van Tilburg et al., 2013). IBS is often referred to as the “brain-gut disorder” due to the notion that bidirectional relationships exist between the mind (i.e., psychological factors) and the body (i.e., physiological factors), and that individuals with IBS have dysregulation of the communication between the “brain” and the “gut” (Kennedy et al., 2012). For example, individuals who have maladaptive cognitive appraisals might tell themselves: “I can’t handle this” in stressful situations, which, in turn, increases their level of stress. The increased stress leads them to engage in maladaptive SPS which adversely impacts their ability to cope with their environment, and this may result in an increase in the severity of their gastrointestinal symptoms (Kennedy et al., 2012). The current study’s evaluation of the relational/problem-solving model of stress and wellbeing with IBS contributed to the body of research that has established relationships between stress and SPS (Bell & D’Zurilla, 2009) and stress and IBS symptoms (Dancey et al., 1995). Consequently, the current study examined the interplay amongst stress, maladaptive SPS, and IBS using this model. Results supported all of the testable hypotheses, providing evidence for previously established connections between stress and maladaptive SPS, and stress and IBS. This investigation also contributed to the SPS literature in two major ways: it used a longitudinal design in a research area dominated by cross-sectional studies, and it also found support for a previously unexplored association between IBS and maladaptive SPS

La evaluación de los progresos en el área musical de alumnos de segundo ciclo de enseñanza básica a través del juego

111 p. La siguiente tesis no es autorizada por el autor para su difusión en formato digitalTodo proceso de enseñanza-aprendizaje precisa de una evaluación. Se evalúa el accionar, se evalúa a los alumnos e incluso se les pide que se auto-evalúen y que co-evalúen. ¿Por qué se hace esto? Se hace porque la evaluación cumple un rol trascendental dentro del quehacer educativo, por lo tanto es necesario e importante que se le considere como tal. En el siguiente informe se busca plasmar la importancia que tiene la evaluación dentro del proceso de enseñanza-aprendizaje y entregar una propuesta de herramienta evaluativa para el área de música, en base al uso de diferentes juegos creados específicamente con esa finalidad, y de esta forma hacer de este un acto natural y cercano para nuestros alumnos, lejos del estrés que produce una evaluación de corte tradicional. Este trabajo considera diversas temáticas de la educación, desde la didáctica hasta la evaluación, y como estas pueden llegar a confluir en el uso del juego como herramienta didáctica de la evaluación. Los resultados de esta investigación se obtuvieron mediante la observación y validación de los juegos que se crearon con ese propósito, por medio de tablas de validez de constructo y contenido respectivamente

Exploring Spatial and Temporal Variation Within Reservoir Food Webs: Predictions for Fish Assemblages

In the limnetic zones of small, highly productive reservoirs, young-of-year (YOY) gizzard shad (Dorosoma cepedianum) or threadfin shad (D. petenense) (henceforth, shad) often attain high densities during spring. Environmental factors facilitating early growth and survival of shad plus potential interspecific competition for zooplankton may reduce growth and survival of YOY bluegill (Lepomis macrochirus), another common species in reservoirs. We hypothesized that fewer YOY bluegill moving from the limnetic zone to the littoral zone in late spring probably slows or prevents the ontogenetic switch to piscivory by YOY largemouth bass (Micropterus salmoides), reducing their oversummer growth, overwinter survival, and hence recruitment to their second year. To determine whether shad and bluegill abundances indeed vary inversely in reservoirs, we quantified densities of YOY shad and bluegill in four reservoirs across several years (1987-1994; N = 22 reservoir-years). To assess how YOY bluegill abundance influenced the ontogenetic dietary switch to fish by largemouth bass, we conducted experiments with differing levels of realism and control (4-m2 littoral cages, 4.5-m2 outdoor pools, and 0.33-m2 laboratory aquaria). In reservoirs, peak YOY bluegill density declined weakly in the limnetic zone but strongly in the littoral zone when peak limnetic YOY Dorosoma spp. exceeded 10 individuals/m3. In pools and aquaria, largemouth bass grew more rapidly at ≥3 than at zero bluegill per largemouth bass. Using known temperatures and largemouth bass growth in a bioenergetics model, we discovered that YOY largemouth bass in pools and aquaria ate ≤65% of their maximum daily consumption potential (in grams of wet mass) at ≥6 bluegill per largemouth bass. In cages, largemouth bass consumed only 40% of their maximum and grew less at bluegill abundances similar to those in pools and aquaria, probably because dense vegetation and depletion of bluegill inhibited predatory success. In reservoirs with abundant shad, reduced littoral bluegill density likely compromises first-year growth and recruitment of largemouth bass. However, variable abiotic and biotic factors may modify YOY bluegill abundance and hence invalidate our predictions for largemouth bass recruitment success. To better predict fish community structure and develop management actions for reservoir ecosystems, multi-scale experimentation should be combined with whole-system manipulations (e.g., via adaptive management) to bound these variable interactions.This research was funded by National Science Foundation grants DEB 9407859 and DEB 9107173 to R. A. Stein and Federal Aid in Sport Fish Restoration Project F-69-P, administered jointly by the U.S. Fish and Wildlife Service and the Ohio Division of Wildlife. A National Science Foundation-sponsored, Research Experiences for Undergraduates supplement to DEB 9107173 supported N. S. Donovan during part of this research. J. E. Garvey was supported by a Presidential Fellowship from The Ohio State University

Translating science fiction in a CAT tool:machine translation and segmentation settings

There is increasing interest in machine assistance for literary translation, but research on how computer-assisted translation (CAT) tools and machine translation (MT) combine in the translation of literature is still incipient, especially for non-Europeanlanguages. This article presents two exploratory studies where English-to-Chinese translators used neural MT to translate science fiction short stories in Trados Studio. One of the studies compares post-editing with a ‘no MT’ condition. The other examinestwo ways of presenting the texts on screen for post-editing, namely by segmenting them into paragraphs or into sentences. We collected the data with the Qualititivity plugin for Trados Studio and describe a method for analysing data collected with this plugin through the translation process research database of the Center for Research in Translation and Translation Technology (CRITT). While post-editing required less technical effort, we did not find MT to be appreciably timesaving. Paragraph segmentation was associated with less post-editing effort on average, though with high translator variability. We discuss the results in the light of broader concepts, such as status-quo bias, and call for more research on the different ways in which MT may assist literary translation, including its use for comparison purposes or, as mentioned by a participant, for ‘inspiration’

Functional Blockade of E-Selectin in Tumor-Associated Vessels Enhances Anti-Tumor Effect of Doxorubicin in Breast Cancer

Chemotherapy is a mainstay of treatment for solid tumors. However, little is known about how therapy-induced immune cell infiltration may affect therapy response. We found substantial CD45+ immune cell density adjacent to E-selectin expressing inflamed vessels in doxorubicin (DOX)-treated residual human breast tumors. While CD45 level was significantly elevated in DOX-treated wildtype mice, it remained unchanged in DOX-treated tumors from E-selectin null mice. Similarly, intravenous administration of anti-E-selectin aptamer (ESTA) resulted in a significant reduction in CD45+ immune cell density in DOX-treated residual tumors, which coincided with a delay in tumor growth and lung metastasis in MMTV-pyMT mice. Additionally, both tumor infiltrating T-lymphocytes and tumor associated-macrophages were skewed towards TH2 in DOX-treated residual breast tumors; however, ESTA suppressed these changes. This study suggests that DOX treatment instigates de novo intratumoral infiltration of immune cells through E-selectin, and functional blockade of E-selectin may reduce residual tumor burden as well as metastasis through suppression of TH2 shift