Caddo Lake Archaeology: Phase I of Archaeological Investigations Along Harrison Bayou, Harrison County, Texas

An important part of the mission of the Caddo Lake Institute, Inc. and its Caddo Lake Scholars Program is the preservation and protection of the unique and irreplaceable cultural heritage of Caddo Lake and its bioregion, the Big Cypress Bayou watershed. The archaeology team of the Scholars Program is meeting these objectives with the initiation of the Harrison Bayou project by: (a) offering archaeological education and training of teachers, students, and potential mentors, (b) through fieldwork and research, identifying, assessing, and designating archaeological, historical, and cultural resources of the Caddo Lake bioregion, and ( c) formulating and implementing strategies for protecting the bioregion\u27s significant cultural resources

Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.Comment: 15 pages, 3 figure

Wilson-Donaldson Stoneware Kiln Site (41DN19)

In July 1998, personnel from Archeological & Environmental Consultants volunteered one day to assist the Denton County Historical Commission in their investigation of the 1850-1880 Wilson-Donaldson stoneware kiln (41DN19) near Sharon Lake, Bryant Branch, and Hickory Creek in the upper Trinity River basin a few miles south-southeast of Denton, Texas. This is one of a number of 19th century stoneware potteries making saltglazed and natural clay slip vessels in Denton County, including the Cranston Pottery (41DN16), Roark Pottery (41DN18), Lambert Pottery (41DN74), and Serran Pottery (41DN75), all sites listed on the National register of Historic Places. The kiln and associated archaeological deposits were in an area being proposed for private development, and it was considered imperative that as much archaeological information be gathered from the site before it was disturbed or destroyed; subsequently, the main kiln at the site (Feature 1) was dismantled—hopefully to be reconstructed in the future—while the remainder of the archaeological deposits were destroyed and removed. During our short foray to the site, we produced a map of the various features at the site, including stoneware kilns, sherd waster piles, clay pits, and traces of structural remains in the vicinity of the other features. Drawings of the plan and vertical profile of Feature 1 were also completed at that time, along with surface collections of stoneware sherds from several features, supplemented with a few shovel tests to assess the character of the archaeological deposits and the excavation of a single 50 x 50 cm unit in the Feature 3 waster pile. In our work, we limited the recovery of artifacts to diagnostic rim sherds from the different vessel forms represented at the kiln, as well to any identified kiln furniture. The stoneware sherds at the Wilson-Donaldson kiln are almost exclusively exterior salt-glazed jars, jugs, churns, and bowls. About 61 percent of the sherds we collected are from ca. 1840-1860 salt-glazed vessels that have a dry interior surface. Interior and exterior salt-glazed sherds are rare (3 percent) in the assemblage, but they are associated with pre-1860 stoneware manufacture. Thirty-six percent are sherds from saltglazed vessels with a natural clay slip interior. It is likely that these vessels were made between 1860-1880, based on Lebo’s (1987:Tables 8-9 and 8- 10) seriation of stoneware interior and exterior glaze types and combinations. One sherd (0.5 percent) has a natural clay slip on both interior and exterior surfaces, and is most likely from a vessel made between 1860-1880, although examples are known from pre-1860 contexts. The Wilson-Donaldson kiln also manufactured clay elbow pipes along with stoneware vessels. None were recovered in our limited work at the site

Getting from A to IRB : Developing an Institutional Review Board at a Historically Black University

Shaw University, the oldest historically black college or university in the southern USA, recently partnered with the University of North Carolina at Chapel Hill, a major research institution in North Carolina, to further develop Shaw’s research infrastructure. One aim of the partnership involved establishing a human research ethics committee and an accompanying administrative structure and research ethics education program. This paper describes the process of developing an entire human research protection program de novo through collaboration with and mentoring by the members of the human research protection program at a nearby major research institution. This paper provides a detailed description of the aims, procedures, accomplishments, and challenges involved in such a project, which may serve as a useful model for other primarily teaching institutions wishing to develop research infrastructure and ethical capacity

Three water restriction schedules used in rodent behavioral tasks transiently impair growth and differentially evoke a stress hormone response without causing dehydration

Water restriction is commonly used to motivate rodents to perform behavioral tasks; however, its effects on hydration and stress hormone levels are unknown. Here, we report daily body weight and bi-weekly packed red blood cell volume and corticosterone in adult male rats across 80 days for three commonly used water restriction schedules. We also assessed renal adaptation to water restriction using post-mortem histological evaluation of renal medulla. A control group received ad libitum water. After one week of water restriction, rats on all restriction schedules resumed similar levels of growth relative to the control group. Normal hydration was observed, and water restriction did not drive renal adaptation. An intermittent restriction schedule was associated with an increase in corticosterone relative to the control group. However, intermittent restriction evokes a stress response which could affect behavioral and neurobiological results. Our results also suggest that stable motivation in behavioral tasks may only be achieved after one week of restriction.Peer reviewe

Beyond Tryptophan Synthase: Identification of Genes That Contribute to Chlamydia trachomatis Survival during Gamma Interferon-Induced Persistence and Reactivation

Chlamydia trachomatis can enter a viable but nonculturable state in vitro termed persistence. A common feature of C. trachomatis persistence models is that reticulate bodies fail to divide and make few infectious progeny until the persistence-inducing stressor is removed. One model of persistence that has relevance to human disease involves tryptophan limitation mediated by the host enzyme indoleamine 2,3-dioxygenase, which converts l-tryptophan to N-formylkynurenine. Genital C. trachomatis strains can counter tryptophan limitation because they encode a tryptophan-synthesizing enzyme. Tryptophan synthase is the only enzyme that has been confirmed to play a role in interferon gamma (IFN-γ)-induced persistence, although profound changes in chlamydial physiology and gene expression occur in the presence of persistence-inducing stressors. Thus, we screened a population of mutagenized C. trachomatis strains for mutants that failed to reactivate from IFN-γ-induced persistence. Six mutants were identified, and the mutations linked to the persistence phenotype in three of these were successfully mapped. One mutant had a missense mutation in tryptophan synthase; however, this mutant behaved differently from previously described synthase null mutants. Two hypothetical genes of unknown function, ctl0225 and ctl0694, were also identified and may be involved in amino acid transport and DNA damage repair, respectively. Our results indicate that C. trachomatis utilizes functionally diverse genes to mediate survival during and reactivation from persistence in HeLa cells

Redefining noradrenergic neuromodulation of behavior : impacts of a modular locus coeruleus architecture

Peer reviewe