Learning Tree Patterns from Example Graphs

This paper investigates the problem of learning tree patterns that return nodes with a given set of labels, from example graphs provided by the user. Example graphs are annotated by the user as being either positive or negative. The goal is then to determine whether there exists a tree pattern returning tuples of nodes with the given labels in each of the positive examples, but in none of the negative examples, and, furthermore, to find one such pattern if it exists. These are called the satisfiability and learning problems, respectively. This paper thoroughly investigates the satisfiability and learning problems in a variety of settings. In particular, we consider example sets that (1) may contain only positive examples, or both positive and negative examples, (2) may contain directed or undirected graphs, and (3) may have multiple occurrences of labels or be uniquely labeled (to some degree). In addition, we consider tree patterns of different types that can allow, or prohibit, wildcard labeled nodes and descendant edges. We also consider two different semantics for mapping tree patterns to graphs. The complexity of satisfiability is determined for the different combinations of settings. For cases in which satisfiability is polynomial, it is also shown that learning is polynomial (This is non-trivial as satisfying patterns may be exponential in size). Finally, the minimal learning problem, i.e., that of finding a minimal-sized satisfying pattern, is studied for cases in which satisfiability is polynomial

School District Student Assignment and Reassignment Policies

<p>This dissertation examines the interplay between school district assignment and reassignment policies and the elementary public school parents select for their children. The sample in all chapters includes the third and fourth grade students in a subset of growing North Carolina school districts from 2003/04 to 2010/11. The data are derived from historical, longitudinal secondary data sources containing student, school, and district records. All chapters employ quantitative longitudinal data analysis methods. Chapter 1 identifies the groups of students who do not comply with their school assignments. Chapter 2 identifies the groups of students who are reassigned to different schools, and to schools of varying quality, when school districts enact reassignment plans. Chapter 3 identifies the groups of students who do not comply with school reassignments. Together, the chapters demonstrate the interplay between residential decisions, school choices, and the resulting educational opportunities of observably different students. Consistent with existing bodies of literature, the findings demonstrate unexplored processes through which advantaged families maintain the most desirable educational opportunities for their children. Policy implications of these findings are also discussed.</p>Dissertatio

Apatite - Cholesterol Agglomerates in Human Atherosclerotic Lesions

The purpose of this study was to examine the ultrastructural relationships of cholesterol crystals and apatite deposits in human atherosclerotic lesions. Segments of human aortic atherosclerotic lesions were obtained at autopsy , fixed in glutaraldehyde and dehydrated without using any organic solvents. The aortic segments were coated with carbon and subjected to various scanning electron microscope analyses. These included secondary electron imaging, back scattering of primary electrons, energy dispersive X-ray analysis of selected spots followed by area mapping of calcium and phosphorus , and cathodoluminescence. The information gathered from scanning of selected areas in the lesions by all the techniques showed that cholesterol crystals and apatite deposits are close to each other, within 10 μm distance or less. Cholesterol crystals are often surrounded by or adjacent to apatite. The results indicate that cholesterol and apatite crystals form closely linked agglomerates in human atherosclerotic lesions. Further studies are needed to determine whether precipitation of calcium and cholesterol are somehow linked during atherosclerotic lesion development

Maximizing Youth Leadership in Out-of-School Time Programs: Six Best Practices from Youth Driven Spaces

This paper aims to provide strategies for youth-serving organizations to maximize opportunities for youth to develop leadership skills within the out-of-school time program context. The sample includes 5 youth-serving agencies who participated in the Youth Driven Spaces initiative led by a Midwest program. Data for this project included observations of youth–adult meetings, field notes from youths’ reflections on key model activities, and interviews with adult staff to identify common challenges and supportive solutions. We identified 6 emergent themes for supporting youth leadership: (a) engage youth in meetings, (b) create opportunities for youth to learn how to be leaders, (c) recognize resistance to youth voice, (d) encourage youth and adults to share constructive feedback, (e) navigate youth–adult boundaries, and (f) practice intentional strategies to retain youth and to onboard new youth and staff. Results provide concrete strategies for practitioners and researchers to empower youth with the skills and resources they need to be effective leader

An Upper Limit on the Albedo of HD 209458b: Direct Imaging Photometry with the MOST Satellite

We present space-based photometry of the transiting exoplanetary system HD 209458 obtained with the MOST (Microvariablity and Oscillations of STars) satellite, spanning 14 days and covering 4 transits and 4 secondary eclipses. The HD 209458 photometry was obtained in MOST's lower-precision Direct Imaging mode, which is used for targets in the brightness range $6.5 < V < 13$. We describe the photometric reduction techniques for this mode of observing, in particular the corrections for stray Earthshine. We do not detect the secondary eclipse in the MOST data, to a limit in depth of 0.053 mmag (1 \sigma). We set a 1 \sigma upper limit on the planet-star flux ratio of 4.88 x 10^-5 corresponding to a geometric albedo upper limit in the MOST bandpass (400 to 700 nm) of 0.25. The corresponding numbers at the 3 \sigma level are 1.34 x 10^-4 and 0.68 respectively. HD 209458b is half as bright as Jupiter in the MOST bandpass. This low geometric albedo value is an important constraint for theoretical models of the HD209458b atmosphere, in particular ruling out the presence of reflective clouds. A second MOST campaign on HD 209458 is expected to be sensitive to an exoplanet albedo as low as 0.13 (1 sigma), if the star does not become more intrinsically variable in the meantime.Comment: 29 pages, 9 figures. Accepted for publication in the Astrophysical Journal (July 2006, v645n1

Effects of swimming in cold water on lipolysis indicators via fibroblast growth factor-21 in male Wistar rats

This study aimed to investigate the effects of swimming in cold water on the release of FGF21 from various tissues and its impact on fat metabolism. Twenty Wistar rats were randomly divided into three groups: untrained (C), trained in thermo-neutral water (TN, 30 °C) and trained in cold water (TC, 15 °C). The training groups swam intervals (2-3 min) until exhaustion, 1 min rest, three days a week for six weeks, with 3-6% bodyweight load. The mRNA expression of variables was determined in white fat tissue (WAT), and FGF21 protein was also measured in the liver, brown fat tissue (BAT), serum, and muscle. The experimental protocols resulted in lower body weight gain, associated with reduced WAT volume; the most remarkable improvement was observed in the TC group. Swimming significantly increased FGF21 protein levels in WAT, BAT, and muscle tissues compared to the C group; substantial increases were in the TC group. Changes in FGF21 were highly correlated with the activation of genes involved in fat metabolisms, such as CPT1, CD36, and HSL, and with glycerol in WAT. The findings indicate a positive correlation between swimming in cold water and the activation of genes involved in fat metabolism, possibly through FGF21 production, which was highly correlated with fat-burning genes

Cardiovascular Programming During and After Diabetic Pregnancy: Role of Placental Dysfunction and IUGR

Intrauterine growth restriction (IUGR) is a condition whereby a fetus is unable to achieve its genetically determined potential size. IUGR is a global health challenge due to high mortality and morbidity amongst affected neonates. It is a multifactorial condition caused by maternal, fetal, placental, and genetic confounders. Babies born of diabetic pregnancies are usually large for gestational age but under certain conditions whereby prolonged uncontrolled hyperglycemia leads to placental dysfunction, the outcome of the pregnancy is an intrauterine growth restricted fetus with clinical features of malnutrition. Placental dysfunction leads to undernutrition and hypoxia, which triggers gene modification in the developing fetus due to fetal adaptation to adverse utero environmental conditions. Thus, in utero genemodification results in future cardiovascular programming in postnatal and adult life. Ongoing research aims to broaden our understanding of the molecular mechanisms and pathological pathways involved in fetal programming due to IUGR. There is a need for the development of effective preventive and therapeutic strategies for the management of growth-restricted infants. Information on the mechanisms involved with in utero epigenetic modification leading to development of cardiovascular disease in adult life will increase our understanding and allow the identification of susceptible individuals as well as the design of targeted prevention strategies. This article aims to systematically review the latest molecular mechanisms involved in the pathogenesis of IUGR in cardiovascular programming. Animal models of IUGR that used nutrient restriction and hypoxia to mimic the clinical conditions in humans of reduced flow of nutrients and oxygen to the fetus will be discussed in terms of cardiac remodeling and epigenetic programming of cardiovascular disease. Experimental evidence of long-term fetal programming due to IUGR will also be included

Evaluation of a Supermarket Environmental Change Intervention: Findings from a Low-Fat Milk Couponing and Educational Marketing Pilot

The purpose of this study was to evaluate a multifaceted, collaborative approach to supermarket environmental change that included in-store couponing and educational marketing to increase low-fat milk purchasing across a 48-store supermarket chain serving predominately Hispanic customers. Point-of-sale (POS) and process data collected during the 16-week program implementation included in-store radio advertising, in-store signage, and POS coupons. POS data were analyzed by the coupon marketing partner, and a chi-square test was conducted to test for significant differences between groups. POS data indicated that 44,050 low-fat milk coupons were issued to traditional full-fat milk purchasing customers with a redemption rate of 5.3%. Of these, 42% became repeat low-fat milk purchasers (i.e., after initial purchase with coupon, customer re-purchased low-fat milk). Results from the chi-square test revealed significant differences in rates of purchase between those who received a coupon (5.87%) and those who did not (4.00%), (χ2 = 8.61, p = .0033). Findings indicate that collaborative public health efforts between retail and marketing partners to engage supermarket customers in a multifaceted yet targeted intervention are feasible and can shift purchasing behaviors towards a healthy alternative. This study has implications for informing future environmental change supermarket strategies

Experimental verification of the treatment of time-dependent flux in circuit quantization

Recent theoretical work has highlighted that quantizing a superconducting circuit in the presence of time-dependent flux $\Phi(t)$ generally produces Hamiltonian terms proportional to $d\Phi/dt$ unless a special allocation of the flux across inductive terms is chosen. Here, we present an experiment probing the effects of a fast flux ramp applied to a heavy-fluxonium circuit. The experiment confirms that na\"ive omission of the $d\Phi/dt$ term leads to theoretical predictions inconsistent with experimental data. Experimental data are fully consistent with recent theory that includes the derivative term or equivalently uses "irrotational variables" that uniquely allocate the flux to properly eliminate the $d\Phi/dt$ term

Identification of tumor-specific Salmonella Typhimurium promoters and their regulatory logic

Conventional cancer therapies are often limited in effectiveness and exhibit strong side effects. Therefore, alternative therapeutic strategies are demanded. The employment of tumor-colonizing bacteria that exert anticancer effects is such a novel approach that attracts increasing attention. For instance, Salmonella enterica serovar Typhimurium has been used in many animal tumor models as well as in first clinical studies. These bacteria exhibit inherent tumoricidal effects. In addition, they can be used to deliver therapeutic agents. However, bacterial expression has to be restricted to the tumor to prevent toxic substances from harming healthy tissue. Therefore, we screened an S. Typhimurium promoter-trap library to identify promoters that exclusively drive gene expression in the cancerous tissue. Twelve elements could be detected that show reporter gene expression in tumors but not in spleen and liver. In addition, a DNA motif was identified that appears to be necessary for tumor specificity. Now, such tumor-specific promoters can be used to safely express therapeutic proteins by tumor-colonizing S. Typhimurium directly in the neoplasi