1,680 research outputs found

    Discordance Between Mitochondrial and Nuclear Contact Zones Within Antelope Ground Squirrels (Ammospermophilus)

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    A common biogeographic pattern found in many co-distributed species along the Baja California peninsula is the genetic divergence in the Vizcaíno Desert. This separation is hypothesized to have been caused by a mid-peninsular seaway that formed during the late Miocene-middle Pleistocene and later dried, allowing contact again between formerly isolated populations. Previous phylogeographic studies on the antelope ground squirrel (Ammospermophilus leucurus) show a mitochondrial DNA break through the middle of the peninsula. We investigated whether (1) the mitochondrial pattern of divergence and secondary contact between the northern and southern Ammospermophilus clades are consistent with results from genome-wide nuclear data and (2) whether genetic admixture is occurring. One hundred thirty-three samples were collected spanning from the northwest US south into the Baja California peninsula and pooled using ddRADseq protocol. Our nuclear DNA analyses show a 335 km divergence between the two contact zones and low levels of admixture. Several individuals belonging to the southern clade have a northern mitochondrial haplotype, suggesting introgression. This introgression and lack of admixture suggests that there may have been ancestral hybridization between the now reproductively isolated populations.No embargoAcademic Major: Zoolog

    Faith-Based Counseling Versus Traditional Psychotherapy: A Phenomenological Evaluation of African American Protestant Experiences

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    This phenomenological study was designed to evaluate the experiences of African American Christian adult clients within traditional psychotherapy and faith-based counseling settings. Research has shown various therapist/counselor identities affect Christian African American clients, and that Christians as well as African Americans have historically been less likely to pursue traditional psychotherapy for a variety of reasons. Participants were six African American Christian adult participants (three traditional psychotherapy participants and three faith-based counseling participants). All participants were asked open-ended questions about their experiences in traditional psychotherapy or faith-based counseling. In addition, they were asked to evaluate several aspects of their therapy/counseling experience on a scale of 1–10: (a) their overall experience within traditional psychotherapy/counseling, (b) the overall effectiveness of their therapist/counselor, and (c) how effectively they thought their therapist/counselor was in their ability to address faith-related content or concerns. To provide context for this study, a literature review was conducted on the history of psychology, the demographics of psychotherapy, the potential impact of psychotherapy on African American clients, and potential gaps in faith-based training among mental health providers. In addition, this study considered additional factors that may influence the traditional psychotherapy/counseling experiences of African American clients. These included barriers to access of care and the underutilization of mental health services among African Americans, the overall health disparities affecting African American people, working alliance factors, the impact of the Black Church on African American life, and the common reliance on faith as a means of coping. This project also considered 2 current research on community-based interventions and culturally sensitive and acceptable means of seeking care for African Americans. Results showed that though all African American Christian participants acknowledged benefits of therapy (across both types), there was an inherent secondary gain for African American Christian clients paired with faith-based therapists/counselors

    Cytokinesis and Dbf2

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    During cell division, the cytoplasm must be divided between the parent and daughter cell. The Mitotic Exit Network (MEN) is a signaling pathway that allows a dividing cell to exit mitosis and complete cytokinesis. Obf2 is a MEN protein kinase in yeast, which provides a simplified model for studying this conserved pathway. By regulating Dbf2s\u27 activity through phosphorylation mutants, its effect on cytokinesis can be studied. Cells were viewed under a microscope, to visualize division errors. Yeast cells that fail to complete cytokinesis will form chains, as the budding daughter cells fail to separate from their parents. Chains of 3 or more cells were considered to exhibit cell separation defects. Cells were also treated with Zymolyase, an enzyme that breaks down yeast cells walls, to determine that chain formation was a result of cytokinetic errors, and not the cell being unable to form the bud scar and close the cell wall. Additionally, new mutant strains were developed by transforming yeast cell lines using bacterial plasmids with Dbf2 mutant alleles. This information is relevant to human health. Dbf2 is a member of the Ndr kinase family. Its human homologue plays a role in the Hippo tumor suppressor pathway. Thus, mutations in this gene can lead to cancer. By studying the impact of mutations and phosphorylation in a simplified system, the overall mechanism can be better understood

    Evaluation of Pt, Ni, and Ni–Mo electrocatalysts for hydrogen evolution on crystalline Si electrodes

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    The dark electrocatalytic and light photocathodic hydrogen evolution properties of Ni, Ni–Mo alloys, and Pt on Si electrodes have been measured, to assess the viability of earth-abundant electrocatalysts for integrated, semiconductor coupled fuel formation. In the dark, the activities of these catalysts deposited on degenerately doped p^+-Si electrodes increased in the order Ni < Ni–Mo ≤ Pt. Ni–Mo deposited on degenerately doped Si microwires exhibited activity that was very similar to that of Pt deposited by metal evaporation on planar Si electrodes. Under 100 mW cm^(−2) of Air Mass 1.5 solar simulation, the energy conversion efficiencies of p-type Si/catalyst photoelectrodes ranged from 0.2–1%, and increased in the order Ni ≈ Ni–Mo < Pt, due to somewhat lower photovoltages and photocurrents for p-Si/Ni–Mo relative to p-Si/Ni and p-Si/Pt photoelectrodes. Deposition of the catalysts onto microwire arrays resulted in higher apparent catalytic activities and similar photoelectrode efficiencies than were observed on planar p-Si photocathodes, despite lower light absorption by p-Si in the microwire structures

    Big Hole (41TV2161): Two Stratigraphically Isolated Middle Holocene Components in Travis County, Texas Volume I

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    During April and May 2006, an archeological team from the Cultural Resources Section of the Planning, Permitting and Licensing Practice of TRC Environmental Corporation’s (TRC) Austin office conducted geoarcheological documentation and data recovery excavations at prehistoric site 41TV2161 (CSJ: 0440-06-006). Investigations were restricted to a 70 centimeter (cm) thick target zone between ca. 220 and 290 cm below surface (bs) on the western side of site 41TV2161 – the Big Hole site in eastern Travis County, Texas. This cultural investigation was necessary under the requirements of Section 106 of the National Historic Preservation Act (NHPA), the implementing regulations of 36CRF Part 800 and the Antiquities Code of Texas (Texas Natural Resource Code, Title 9, Chapter 191 as amended) to recover a sample of the significant cultural materials prior to destruction by planned construction of State Highway 130 (SH 130). The latter by a private construction firm – Lone Star Infrastructure. This necessary data recovery was for Texas Department of Transportation (TxDOT), Environmental (ENV) Affairs Division under a Scientific Services Contract No. 577XXSA003 (Work Authorization No. 57701SA003). Over the years since the original award, multiple work authorizations between TxDOT and TRC were implemented and completed towards specific aspects of the analyses and reporting. The final analyses and report were conducted under contract 57-3XXSA004 (Work Authorization 57-311SA004). All work was under Texas Antiquities Committee Permit No. 4064 issued by the Texas Historical Commission (THC) to J. Michael Quigg. Initially, an archeological crew from Hicks & Company encountered site 41TV2161 during an intensive cultural resource inventory conducted south of Pearce Lane along the planned construction zone of SH 130 in the fall of 2005. Following the initial site discovery, archeologists expanded their investigations to the west across the SH 130 right-of-way, and completed excavation of 10 backhoe trenches, 13 shovel tests, and 11 test units at site 41TV2161. The investigations encountered at least seven buried cultural features and 1,034 artifacts, some in relatively good context. The survey and testing report to TxDOT presented their findings and recommendations (Campbell et al. 2006). The ENV Affairs Division of TxDOT and the THC reviewed the initial findings and recommendations, and determined site 41TV2161 was eligible for listing on the National Register of Historic Places and as State Antiquities Landmark as the proposed roadway development was to directly impact this important site and further excavations were required. Subsequently, TRC archeologists led by Paul Matchen (Project Archeologist) and J. Michael Quigg (Principal Investigator) initiated data recovery excavations through the mechanical-removal of between 220 and 250 cm of sediment from a 30-by-40 meter (m) block area (roughly 3,000 m3). This was conducted to allow hand-excavations to start just above the deeply buried, roughly 70 cm thick targeted zone of cultural material. Mechanical stripping by Lone Star Infrastructure staff created a large hole with an irregular bottom that varied between 220 and 260 cmbs. To locate specific areas to initiate hand-excavations within the mechanically stripped area, a geophysical survey that employed ground penetrating radar (GPR) was conducted by Tiffany Osburn then with Geo-Marine in Plano, Texas. Over a dozen electronic anomalies were detected through the GPR investigation. Following processing, data filtering, and assessment, Osburn identified and ranked the anomalies for investigation. The highest ranked anomalies (1 through 8) were thought to have the greatest potential to represent cultural features. Anomalies 1 through 6 were selected and targeted through hand-excavations of 1-by-1 m units that formed continuous excavation blocks of various sizes. Blocks were designated A, B, C, D, E, and F. The type, nature, quantity, and context of encountered cultural materials in each block led the direction and expansion of each excavation block as needed. In total, TRC archeologists hand-excavated 38.5 m3 (150 m2) from a vertically narrow target zone within this deep, multicomponent and stratified prehistoric site. Hand-excavation in the two largest Blocks, B and D (51 m2 and 62 m2 respectively), revealed two vertically separate cultural components between roughly 220 and 290 cmbs. The younger component was restricted to Block B and yielded a Bell/Andice point and point base, plus a complete Big Sandy point. These points were associated with at least eight small burned rock features, one cluster of ground stone tools, limited quantities of lithic debitage, few formal chipped and ground stone tools, and a rare vertebrate faunal assemblage. Roughly 20 to 25 cm below the Bell/Andice component in Block B and across Block D was a component identified by a single corner-notched Martindale dart point. This point was associated with a scattered burned rocks, three charcoal stained hearth features, scattered animal, bird, and fish bones, mussel shells, and less than a dozen formal chipped and ground stone tools. Both identified components contained cultural materials in good stratigraphic context with high spatial integrity. Significant, both were radiocarbon dated by multiple charcoal samples to a narrow 200-year period between 5250 and 5450 B.P. during the middle Holocene. With exception of the well-preserved faunal assemblages, perishable materials were poorly preserved in the moist silty clay loam. Charcoal lacked structure and was reduced to dark stains. Microfossils (e.g., phytoliths and starch gains) were present, although in very limited numbers and deteriorated conditions. The four much smaller Blocks (A, C, E, and F) yielded various quantities of cultural material and features, but these blocks also lacked sufficient charcoal dates and diagnostic artifacts Those artifacts and samples were left unassigned and analyzed separately from the Bell/Andice and Martindale components. The two well-defined components in Blocks B and D are the focus of this technical report. The components provide very significant data towards understanding rare and poorly understood hunter-gatherer populations during late stages of the Altithermal climate period. This final report builds upon the interim report submitted to TxDOT (Quigg et al. 2007) that briefly described the methods, excavations, preliminary findings, initial results from six feasibility studies, and proposed an initial research design for data analyses. Context and integrity of the cultural materials in the two identified components was excellent. This rare circumstance combined with detailed artifact analyses, solid documentation of their ages through multiple radiocarbon dates, and multidisciplinary approach to analyses, allowed significant insights and contributions concerning the two populations involved. Results provide a greater understanding of human behaviors during a rarely identified time in Texas Prehistory. The cultural materials and various collected samples were temporarily curated at TRC’s Austin laboratory. Following completion of analyses and acceptance of this final report, the artifacts, paper records, photographs, and electronic database were permanently curated at the Center for Archaeological Studies (CAS) at Texas State University in San Marcos

    Non-interference for deterministic interactive programs

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    We consider the problem of defining an appropriate notion of non-interference (NI) for deterministic interactive programs. Previous work on the security of interactive programs by O'Neill, Clarkson and Chong (CSFW 2006) builds on earlier ideas due to Wittbold and Johnson (Symposium on Security and Privacy 1990), and argues for a notion of NI defined in terms of strategies modelling the behaviour of users. We show that, for deterministic interactive programs, it is not necessary to consider strategies and that a simple stream model of the users' behaviour is sufficient. The key technical result is that, for deterministic programs, stream-based NI implies the apparently more general strategy-based NI (in fact we consider a wider class of strategies than those of O'Neill et al). We give our results in terms of a simple notion of Input-Output Labelled Transition System, thus allowing application of the results to a large class of deterministic interactive programming languages

    The work environment disability-adjusted life year for use with life cycle assessment: a methodological approach

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    BACKGROUND: Life cycle assessment (LCA) is a systems-based method used to determine potential impacts to the environment associated with a product throughout its life cycle. Conclusions from LCA studies can be applied to support decisions regarding product design or public policy, therefore, all relevant inputs (e.g., raw materials, energy) and outputs (e.g., emissions, waste) to the product system should be evaluated to estimate impacts. Currently, work-related impacts are not routinely considered in LCA. The objectives of this paper are: 1) introduce the work environment disability-adjusted life year (WE-DALY), one portion of a characterization factor used to express the magnitude of impacts to human health attributable to work-related exposures to workplace hazards; 2) outline the methods for calculating the WE-DALY; 3) demonstrate the calculation; and 4) highlight strengths and weaknesses of the methodological approach. METHODS: The concept of the WE-DALY and the methodological approach to its calculation is grounded in the World Health Organization’s disability-adjusted life year (DALY). Like the DALY, the WE-DALY equation considers the years of life lost due to premature mortality and the years of life lived with disability outcomes to estimate the total number of years of healthy life lost in a population. The equation requires input in the form of the number of fatal and nonfatal injuries and illnesses that occur in the industries relevant to the product system evaluated in the LCA study, the age of the worker at the time of the fatal or nonfatal injury or illness, the severity of the injury or illness, and the duration of time lived with the outcomes of the injury or illness. RESULTS: The methodological approach for the WE-DALY requires data from various sources, multi-step instructions to determine each variable used in the WE-DALY equation, and assumptions based on professional opinion. CONCLUSIONS: Results support the use of the WE-DALY in a characterization factor in LCA. Integrating occupational health into LCA studies will provide opportunities to prevent shifting of impacts between the work environment and the environment external to the workplace and co-optimize human health, to include worker health, and environmental health
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