On tt-core and self-conjugate (2t−1)(2t-1)-core partitions in arithmetic progressions

We extend recent results of Ono and Raji, relating the number of self-conjugate $7$-core partitions to Hurwitz class numbers. Furthermore, we give a combinatorial explanation for the curious equality $2\operatorname{sc}_7(8n+1) = \operatorname{c}_4(7n+2)$. We also conjecture that an equality of this shape holds if and only if $t=4$, proving the cases $t\in\{2,3,5\}$ and giving partial results for $t>5$

The breakup of East Gondwana : insights from plate modeling, basin analysis, and numerical experiments

During the Early Cretaceous, East Gondwana began to fragment. Due to temporal proximity to the Cretaceous Normal Superchron and a lack of well resolved seafloor fabric, our understanding of this breakup has historically been limited. A new interpretation of the marine magnetic anomalies preserved within the Somali Basin, provides insight into the motions of the East Gondwana from the Late Jurassic through the Early Mesozoic. When combined and compared with magnetic anomaly interpretations from coeval regional basins, the timing of East Gondwana breakup can be constrained to begin at M15n (135.76 Ma). Within the Enderby Basin, East Antarctica, oceanic and thinned continental crust preserve a record of this rifting. Previous works have suggested that a wide (500 km) domain of thinned continental crust exists between the present-day coastline and a regional, high-amplitude, magnetic anomaly. We offer an alternative interpretation of the Enderby Basin crustal structure, where much of this postulated continental crust is instead thin, proto-ocean crust. This interpretation is based on the lack of isostatically observable crustal thinning throughout the domain, as would be expected for rifted continental blocks. Throughout much of this domain, the crust instead appears to be rugged, thin (<6 km), and of relatively constant thickness, resembling oceanic crust formed at ultraslow/slow ridges. The preferred tectonic interpretation is that, immediately after continental breakup, magmatic production/emplacement was low and formed this proto-ocean domain. A later reorganization of the magmatic system allowed for normal ocean crust to form and is manifest today as a change in crustal structure and thickness and corresponding magnetic anomaly. Numerical modeling experiments were undertaken to investigate potential influences on melt production during passive continental extension. Factors determined to favor delayed magmatic emplacement include: an initial cool lithosphere geotherm, thin crust, rapid extension rates, low mantle potential temperature, and strong crustal rheology. If magmatic emplacement is sufficiently delayed, these factors may influence formation of a magma-poor margin and/or proto-ocean domain. In the Enderby Basin, Permo-Triassic rifting in the Lambert Graben appears to have previously thinning the continental crust. This pre-breakup thinning may be ultimately responsible for the later formation of the observed proto-ocean domain during East Gondwana breakup.Geological Science

EMBODIED POLITICAL ECOLOGIES OF HEALTH: A CASE STUDY OF ALCOHOL AND INFECTIOUS DISEASE IN THE UPPER WEST REGION OF GHANA

This research is a case study informed by qualitative methodologies examining perceptions of the misuse of an unregistered gin {akpeteshie), and it\u27s role within the promulgation of hepatitis b in the Upper West Region of Ghana. Four research objectives are addressed: 1) to describe the nature of alcohol use among adults; 2) to explore local perceptions about hepatitis b held by adults in the region; 3) to examine the nature of health accessibility in the region; and, 4) to examine the links between alcohol use and the spread of hepatitis b, including the social­ environmental processes that underwrite these links. Thematic analysis of nine focus groups with residents (n=88) and seven key informant interviews indicate that the relationship between alcohol misuse and hepatitis is underwritten by several factors emerging from the physical environment (i.e. drought, isolation) and the social environment (i.e. changing norms surrounding consumption, desires for coping, poverty)

Insertion of the CXC chemokine ligand 9 (CXCL9) into the mouse hepatitis virus genome results in protection from viral-induced encephalitis and hepatitis.

The role of the CXC chemokine ligand 9 (CXCL9) in host defense following infection with mouse hepatitis virus (MHV) was determined. Inoculation of the central nervous system (CNS) of CXCL9-/- mice with MHV resulted in accelerated and increased mortality compared to wild type mice supporting an important role for CXCL9 in anti-viral defense. In addition, infection of RAG1-/- or CXCL9-/- mice with a recombinant MHV expressing CXCL9 (MHV-CXCL9) resulted in protection from disease that correlated with reduced viral titers within the brain and NK cell-mediated protection in the liver. Survival in MHV-CXCL9-infected CXCL9-/- mice was associated with reduced viral burden within the brain that coincided with increased T cell infiltration. Similarly, viral clearance from the livers of MHV-CXCL9-infected mice was accelerated but independent of increased T cell or NK cell infiltration. These observations indicate that CXCL9 promotes protection from coronavirus-induced neurological and liver disease

Who Benefits from KIPP?

The nation's largest charter management organization is the Knowledge is Power Program (KIPP). KIPP schools are emblematic of the No Excuses approach to public education, a highly standardized and widely replicated charter model that features a long school day, an extended school year, selective teacher hiring, strict behavior norms, and a focus on traditional reading and math skills. No Excuses charter schools are sometimes said to focus on relatively motivated high achievers at the expense of students who are most diffiult to teach, including limited English proficiency (LEP) and special education (SPED) students, as well as students with low baseline achievement levels. We use applicant lotteries to evaluate the impact of KIPP Academy Lynn, a KIPP school in Lynn, Massachusetts that typifies the KIPP approach. Our analysis focuses on special needs students that may be underserved. The results show average achievement gains of 0.36 standard deviations in math and 0.12 standard deviations in reading for each year spent at KIPP Lynn, with the largest gains coming from the LEP, SPED, and low-achievement groups. The average reading gains are driven almost completely by SPED and LEP students, whose reading scores rise by roughly 0.35 standard deviations for each year spent at KIPP Lynn.human capital, charter schools, achievement

An Intrinsic Model for Graphite Oxidation and the Effects of Microstructural Features on Apparent Rate

The very high temperature reactor (VHTR) is the latest generation of high-temperature gas-cooled reactors (HTGR). The VHTR has higher outlet temperatures than a traditional HTGR with outlet temperatures up to 1000 °C. This high outlet temperature permits emissions-free process heat in the form of high-quality steam for high temperature industrial applications. Moreover, the high temperatures of the reactor could potentially be used for hydrogen production from water or high efficiency electrical power production (~50% efficiency of thermal to electrical power conversion). The VHTR is designed to employ helium as its coolant and uses graphite for its neutron moderator and as a key structural component for the core. Graphite is used because of it excellent structural stability at high temperatures, high thermal inertia, and the relatively low cost of its production. Since graphite is a key component to the VHTR, the integrity of the graphite is critically linked to the operable lifetime of the reactor. Thorough characterization of the graphite material used, as well as a complete understanding of the mechanisms behind graphite’s life-limiting phenomena is critical to understanding the limits of safe operation for the VHTR. Graphite is not a new high temperature nuclear material; in fact, it has been used in nuclear reactor designs since the very first reactor went critical in December of 1942. Due to its continued use in reactors, a major focus has been placed on understanding graphite’s long-term degradation in a radiation environment, and thus many of the phenomena responsible for degradation are well known. Unfortunately, graphite is a complicated/complex material in that the properties are highly dependent upon the initial source of carbon, as well as variations in the coke type, size and relative quantities of filler and binder, and the manufacturing process used. Thus, each graphite used for nuclear applications is in some sense a new material with unique properties that must be thoroughly characterized before use in a reactor. This dissertation research is focused on the pre-irradiation characterization of IG-110, PGX, NBG-18, and PCEA commercial graphites, the atomic level defects involved in irradiation induced shrinkage and swelling of these graphite materials, and finally the development of a unified reaction model for the oxidation of all high-purity nuclear graphites with oxygen. While similar characterizations and mechanistic studies have been made, many of the techniques used in this study such as electron energy loss spectroscopy (EELS), image processing and analysis, and filtering of high resolution lattice images were either impractical or unavailable in the past. This dissertation seeks to build on past studies of classical reactor grade graphites and use modern experimental techniques to further our understanding of the specific graphites examined and the underlying mechanism that contribute to graphite degradation. In Chapter Two, microstructural characterization of the filler and binder materials is performed. All grades examined were well graphitized in both the binder and filler, although the spatial domains of crystallites were significantly smaller in the binder. Turbostratic graphite, indicated by an elliptical diffraction pattern, was present in all grades. The microcracks, which are known to contribute to the bulk materials shrinkage and later swelling, were found to vary significantly in size, shape, and quantity with graphite grade. Chapter Three examines the atomic scale defects responsible for irradiation induced swelling and microcrack closure via transmission electron microscopy under electron beam irradiation. Utilization of noise-filtering in the frequency domain of lattice images and videos allowed analysis of the formation of vacancy loops, interstitial loops, and resulting dislocations with unprecedented clarity. The dislocations were observed to undergo positive climb resulting in the formation of extra basal planes. This in addition with the reduction in atomic density evidenced by electron energy loss spectroscopy is believed to be responsible for the graphite swelling in the c-direction and microcrack closure. Using optical microscopy, the macro-scale features of the filler particles and macro-porosity were characterized in Chapter Four. The average size and shape of the two-dimensional cross-sections of the filler particles for each grade was determined. A qualitative trend was found between the aspect ratio of the particles and the degree of alignment of the particle crystallites. To characterize the porosity, image analysis was performed using code written in matlab. Probability densities were determined for the size and shape of the macroporosity. Furthermore, a preferred orientation was observed for all grades characterized. The code for two-dimensional analysis used for the corresponding publication is currently being modified to analyze three-dimensional input data from µX-ray CT scans and will be published in a future journal article. In Chapter Five, the oxidation of NBG-18 nuclear graphite was studied. A reaction model was developed based upon the actual oxygen transfer mechanism for the graphite-oxygen reaction system. The parameters are therefore physically meaningful and directly related to individual elementary reaction rates within the mechanism. The Arrhenius parameters are in excellent agreement with experimental and theoretical measurements of the same elementary reactions. Given the wide variety of high-purity graphite sources used in this literature and excellent agreement between measured and predicted values, the developed intrinsic model should be applicable to all nuclear-grade graphites. Moreover, the model can be extrapolated outside the experimental temperature and pressure range with much larger degrees of certainty due to the relationship of the fitted parameters to the physical reaction mechanism

A GPU-accelerated package for simulation of flow in nanoporous source rocks with many-body dissipative particle dynamics

Mesoscopic simulations of hydrocarbon flow in source shales are challenging, in part due to the heterogeneous shale pores with sizes ranging from a few nanometers to a few micrometers. Additionally, the sub-continuum fluid-fluid and fluid-solid interactions in nano- to micro-scale shale pores, which are physically and chemically sophisticated, must be captured. To address those challenges, we present a GPU-accelerated package for simulation of flow in nano- to micro-pore networks with a many-body dissipative particle dynamics (mDPD) mesoscale model. Based on a fully distributed parallel paradigm, the code offloads all intensive workloads on GPUs. Other advancements, such as smart particle packing and no-slip boundary condition in complex pore geometries, are also implemented for the construction and the simulation of the realistic shale pores from 3D nanometer-resolution stack images. Our code is validated for accuracy and compared against the CPU counterpart for speedup. In our benchmark tests, the code delivers nearly perfect strong scaling and weak scaling (with up to 512 million particles) on up to 512 K20X GPUs on Oak Ridge National Laboratory's (ORNL) Titan supercomputer. Moreover, a single-GPU benchmark on ORNL's SummitDev and IBM's AC922 suggests that the host-to-device NVLink can boost performance over PCIe by a remarkable 40\%. Lastly, we demonstrate, through a flow simulation in realistic shale pores, that the CPU counterpart requires 840 Power9 cores to rival the performance delivered by our package with four V100 GPUs on ORNL's Summit architecture. This simulation package enables quick-turnaround and high-throughput mesoscopic numerical simulations for investigating complex flow phenomena in nano- to micro-porous rocks with realistic pore geometries

Development of a culturally appropriate computer-delivered tailored internet-based health literacy intervention for spanish-dominant hispanics living with HIV

Background: Low health literacy is associated with poor medication adherence in persons with human immunodeficiency virus (HIV), which can lead to poor health outcomes. As linguistic minorities, Spanish-dominant Hispanics (SDH) face challenges such as difficulties in obtaining and understanding accurate information about HIV and its treatment. Traditional health educational methods (e.g., pamphlets, talking) may not be as effective as delivering through alternate venues. Technology-based health information interventions have the potential for being readily available on desktop computers or over the Internet. The purpose of this research was to adapt a theoretically-based computer application (initially developed for English-speaking HIV-positive persons) that will provide linguistically and culturally appropriate tailored health education to Spanish-dominant Hispanics with HIV (HIV¿+¿SDH).MethodsA mixed methods approach using quantitative and qualitative interviews with 25 HIV¿+¿SDH and 5 key informants guided by the Information-Motivation-Behavioral (IMB) Skills model was used to investigate cultural factors influencing medication adherence in HIV¿+¿SDH. We used a triangulation approach to identify major themes within cultural contexts relevant to understanding factors related to motivation to adhere to treatment. From this data we adapted an automated computer-based health literacy intervention to be delivered in Spanish.ResultsCulture-specific motivational factors for treatment adherence in HIV¿+¿SDH persons that emerged from the data were stigma, familismo (family), mood, and social support. Using this data, we developed a culturally and linguistically adapted a tailored intervention that provides information about HIV infection, treatment, and medication related problem solving skills (proven effective in English-speaking populations) that can be delivered using touch-screen computers, tablets, and smartphones to be tested in a future study.ConclusionUsing a theoretically-grounded Internet-based eHealth education intervention that builds on knowledge and also targets core cultural determinants of adherence may prove a highly effective approach to improve health literacy and medication decision-making in this group

Microstructural Characterization of Next Generation Nuclear Graphites

This article reports the microstructural characteristics of various petroleum and pitch based nuclear graphites (IG-110, NBG-18, and PCEA) that are of interest to the next generation nuclear plant program. Bright-field transmission electron microscopy imaging was used to identify and understand the different features constituting the microstructure of nuclear graphite such as the filler particles, microcracks, binder phase, rosette-shaped quinoline insoluble (QI) particles, chaotic structures, and turbostratic graphite phase. The dimensions of microcracks were found to vary from a few nanometers to tens of microns. Furthermore, the microcracks were found to be filled with amorphous carbon of unknown origin. The pitch coke based graphite (NBG-18) was found to contain higher concentration of binder phase constituting QI particles as well as chaotic structures. The turbostratic graphite, present in all of the grades, was identified through their elliptical diffraction patterns. The difference in the microstructure has been analyzed in view of their processing conditions