Archeological Testing at 41TR170, along the Clear Fork of the Trinity River, Tarrant County, Texas

Archeologists from Geo-Marine, Inc., were subcontracted through Prewitt and Associates, Inc., of Austin to conduct National Register of Historic Places evaluative testing at archeological site 41TR170, located in Tarrant County, Texas. This work (Geo-Marine project number 30353.06.02) was conducted for the Environmental Affairs Division of the Texas Department of Transportation under contract/work authorization 57524SA006. The archeological remains are located on and in the alluvial terrace of the Clear Fork of the Trinity River, within the proposed 130-meter-wide right-of-way of State Highway 121 in southwestern Fort Worth. The work was conducted to comply with Section 106 of the National Historic Preservation Act of 1969, as amended (Public Law 89-665); the Department of Transportation Act of 1966 (Public Law 89-670); and the Antiquities Code of Texas, as incorporated into Title 98, Chapter 191, of the Natural Resources Code of Texas of 1977, as amended. The work was conducted under Texas Antiquities Permit Number 3699 issued by the Texas Historical Commission. A three-stage field tactic was used during the testing of the site. Stage 1, conducted between March 15 and 29, 2005, consisted of archeological monitoring of the mechanical excavation of 28 backhoe trenches, followed by geomorphological field studies of the trench profiles. Trenches were placed both north and south of a relic channel of the Clear Fork of the Trinity River; the present channel was formed in the late 1960s by river-straightening channelization efforts. Efforts were made to ensure archeological sampling of all feature- and artifact-bearing areas previously identified in trenches dug during the 2000 archeological survey. The second stage, which occurred between March 21 and April 29, 2005, involved the manual excavation of 10 test units to depths of 2 meters below surface using standard 10-centimeter-thick levels. The purpose of this phase was to assess the reliability of the backhoe trench monitoring activities and to locate occupation zones worthy of further excavations. The third stage of field investigations was conducted between May 2 and June 3, 2005, and consisted of the mechanical stripping of the overburden above target occupation surfaces and the manual excavation of three block excavations, each 9 square meters, to a depth of 40 centimeters below surface. Upon completion of the fieldwork, a fourth stage comprised a limited analysis to document the nature of the recovered assemblage and to make National Register recommendations about the site, and a final stage was to design a plan for further study or analysis that would then be based on the results of an interim report. The geomorphic investigations, coupled with the processing of eight radiocarbon dates, ascertained that the upper 2 meters of the Clear Fork sediments date to the past 2,900 years. All trenches contained evidence of the regionally dominant West Fork paleosol that is buried under a thin layer of recent alluvium. Beneath the West Fork paleosol were grayish and yellowish clayey strata, and stringers of pea-sized gravels could be correlated to many of the trenches onsite. The substrate for a series of trenches dug into the south edge of the site encountered cemented gravels that likely date to the Pleistocene age. These gravels extend above the Holocene alluvial sediments onsite and provide some minor relief above the floodplain. Although some bioturbation has blurred boundaries between the West Fork paleosol and more recent sediments, the degree of sediment movement is not as pronounced as observed in many other parts of Texas. The excavations generally documented a series of low-density, highly stratified occupations that could not be correlated with any great assurance. The site context and integrity of deposits are generally excellent. Nevertheless, the paucity of remains in most areas is generally insufficient to provide data necessary to address many regional research questions. Site 41TR170 is not unique in this regard, because many sites within the Trinity River basin seem to be short-term specialized logistical extractive activity areas rather than campsites. Two areas of 41TR170, however, seem to be exceptions to low-density, brief occupations and contain a range of features unlike any previously encountered or recorded in the Clear Fork of the Trinity River. In an area located about 60 meters north of the relic river channel, Block 2 exposed part of a deeply buried (180–220 centimeters below surface) ashy zone with abundant charcoal flecks and burned clay daub that occasionally retained impressions of sticks and small posts. Three burned rock features (small pits, scattered rocks, and rock dump concentrations) were found within this ashy zone, but they were not associated with the genesis of the ash. Bone preservation in this zone was good (numbering 121 specimens), but only one stone tool and four pieces of manufacture/maintenance debris were found. Based on the stratigraphic position and the recovery of one unclassified dart point, this feature is possibly Transitional Archaic in affiliation. Indeed, four radiocarbon dates from two features and the top and bottom of the ashy zone reaffirm that the occupation dates between A.D. 540 and 710 (two sigma dates, tree-ring calibrated), and relates to the Transitional Archaic period. The genesis of the thick ashy zone is problematic and not well understood. The radiocarbon dates suggest that the 40-centimeter-thick ashy zone did not develop instantaneously but rather apparently accumulated over a span of about 180 years (ca. 1,270 and 1,450 years ago). Even though a few rock features and some relatively high density of bone are preserved in this ashy sediment, the low density of remains suggests that the deposit cannot be considered an occupation midden. The age range also suggests that this is not a burned architectural structure. The formation process resulting in a 40-centimeter-thick ashy zone remains unknown. In an area almost 150 meters south of the relic channel, an extensive area of burned rock covering at least 12-x-12 meters was encountered. Noncontiguous Blocks 1 and 3 were opened to explore the variability of burned rock features and ascertain the kinds of remains present. The recovery of two dart points (a Trinity and a Yarbrough) at comparable depths of 90 to 130 centimeters below surface suggests that this area along the edge of the Pleistocene gravel terrace was repeatedly occupied during the Late Archaic period. Among the burned rock features revealed in Block 3 was one large incipient burned rock oven with a pit measuring 2.54 meters in diameter surrounded by a discard ring of burned rocks that were only some 20 centimeters thick. Another cluster of burned rock more deeply buried in the sediments suggests multiple occupations. In adjacent Block 1 were two smaller (possible) pit ovens about 1 meter in diameter, an elongated pile of rock stored for reuse, a few rake-off piles or dumps, and one area of fitted burned rock that might have served as a large griddle-like feature. Tools and chipped stone debris were moderately abundant in Block 1, but rare in Block 3. Bone preservation in this area was very poor, although several hundred fragments of scattered freshwater mussel shell were present. Analysis of shell umbos or hinges indicates that about 59 shells were present in Block 1 and only 50 hinges in Block 3; none were concentrated into discrete discard features. The size, density, and morphological variability of the burned rock features are unlike anything previously seen in the Trinity River basin. Four radiocarbon dates from Blocks 1 and 3 suggest that the series of occupations date between A.D. 540 and 780 (2-sigma dates, tree-ring calibrated). Indeed the radiocarbon dates indicate that the activities resulting in the accumulation of dense burned rock features exposed in Blocks 1 and 3 are culturally contemporaneous with the activities occurring in the thick ashy zone located some 170 to 210 meters apart, even though they undoubtedly represent multiple reuse of the area. The two areas may not have been occupied simultaneously, for the low artifact density suggests that comparable groups of people from the Transitional Archaic period made the distinctly different occupational signatures in the two areas. The testing phase of work at 41TR170 has documented considerable variability in feature forms during the Transitional Archaic period for the Trinity River basin. Test probes also strongly suggest that many more burned rock features occur parallel to the Pleistocene gravel terrace. In this regard, the testing has not exhausted the information potential related to the spatial patterning in activities by these people. However, the associated stone, shell, and bone artifact assemblages are relatively meager. Similarly, extensive flotation has failed to find any macrobotanical remains other than a single nutshell and small amounts of wood charcoal. Efforts to retrieve lipids samples from the burned rock feature proved to be successful, but the results were not very helpful in providing insight into the diversity of feature activities. Although examination of more burned rock features may stumble on examples of cooking accidents that preserve ancient foodstuff, the current robust level of testing suggests that the information content from the site is relatively limited. For this reason, even though the site is of considerable interest from a regional perspective, the site seemingly does not have the potential to make further contributions to the knowledge of the region. Thus, site 41TR170 fails to meet the standards of Criterion D or any other significance standard required for assessing National Register eligibility. Site 41TR170 is recommended as not eligible for National Register inclusion, and no further archeological investigations are recommended

Can a microscopic stochastic model explain the emergence of pain cycles in patients?

A stochastic model is here introduced to investigate the molecular mechanisms which trigger the perception of pain. The action of analgesic drug compounds is discussed in a dynamical context, where the competition with inactive species is explicitly accounted for. Finite size effects inevitably perturb the mean-field dynamics: Oscillations in the amount of bound receptors spontaneously manifest, driven by the noise which is intrinsic to the system under scrutiny. These effects are investigated both numerically, via stochastic simulations and analytically, through a large-size expansion. The claim that our findings could provide a consistent interpretative framework to explain the emergence of cyclic behaviors in response to analgesic treatments, is substantiated.Comment: J. Stat. Mech. (Proceedings UPON2008

Fresh and hardened properties of self-compacting concrete modified with lightweight and recycled aggregates

A produção de concretos auto compactáveis de baixa massa específica tornou-se um grande desafio para a engenharia civil, principalmente quanto à dosagem e manutenção das resistências mecânicas. Nesse contexto, o objetivo deste trabalho foi analisar concretos autoadensáveis (CAA) produzidos com agregados leves e reciclados. Fixou-se as dosagens de sílica ativa, pó de pedra, pedrisco, argila expandida e superplastificante, variando-se a porcentagem do resíduo de borracha em 5% e 10%, em substituição ao agregado miúdo. As amostras foram submetidas aos ensaios de espalhamento, viscosidade, habilidade passante, resistências à compressão e à tração por compressão diametral e, massa específica. Verificou-se que os CAA produzidos apresentaram coesão e trabalhabilidade adequados, bem como atendem as condições normativas para uso em peças pré-moldadas e estruturais1117684COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESsem informaçã

Measurement of the parity violating 6S-7S transition amplitude in cesium achieved within 2 \times 10^{-13} atomic-unit accuracy by stimulated-emission detection

We exploit the process of asymmetry amplification by stimulated emission which provides an original method for parity violation (PV) measurements in a highly forbidden atomic transition. The method involves measurements of a chiral, transient, optical gain of a cesium vapor on the 7S-6P_{3/2} transition, probed after it is excited by an intense, linearly polarized, collinear laser, tuned to resonance for one hyperfine line of the forbidden 6S-7S transition in a longitudinal electric field. We report here a 3.5 fold increase, of the one-second-measurement sensitivity, and subsequent reduction by a factor of 3.5 of the statistical accuracy compared with our previous result [J. Gu\'ena et al., Phys. Rev. Lett. 90, 143001 (2003)]. Decisive improvements to the set-up include an increased repetition rate, better extinction of the probe beam at the end of the probe pulse and, for the first time to our knowledge, the following: a polarization-tilt magnifier, quasi-suppression of beam reflections at the cell windows, and a Cs cell with electrically conductive windows. We also present real-time tests of systematic effects, consistency checks on the data, as well as a 1% accurate measurement of the electric field seen by the atoms, from atomic signals. PV measurements performed in seven different vapor cells agree within the statistical error. Our present result is compatible with the more precise Boulder result within our present relative statistical accuracy of 2.6%, corresponding to a 2 \times 10^{-13} atomic-unit uncertainty in E_1^{pv}. Theoretical motivations for further measurements are emphasized and we give a brief overview of a recent proposal that would allow the uncertainty to be reduced to the 0.1% level by creating conditions where asymmetry amplification is much greater.Comment: Article 21 pages, 6 figures, 3 tables Typos, addition of few comments and little more data (1 week) leading to a slight reduction of the error bar Accepted for publication in Phys.Rev.

A new Manifestation of Atomic Parity Violation in Cesium: a Chiral Optical Gain induced by linearly polarized 6S-7S Excitation

We have detected, by using stimulated emission, an Atomic Parity Violation (APV) in the form of a chiral optical gain of a cesium vapor on the 7S - 6P$_{3/2}$ transition,consecutive to linearly polarized 6S-7S excitation. We demonstrate the validity of this detection method of APV, by presenting a 9% accurate measurement of expected sign and magnitude. We underline several advantages of this entirely new approach in which the cylindrical symmetry of the set-up can be fully exploited. Future measurements at the percent level will provide an important cross-check of an existing more precise result obtained by a different method.Comment: 4 pages, 2 figure

Atomic Parity Violation : Principles, Recent Results, Present Motivations

We review the progress made in the determination of the weak charge, Q\_w, of the cesium nucleus which raises the status of Atomic Parity Violation measurements to that of a precision electroweak test. Not only is it necessary to have a precision measurement of the electroweak asymmetry in the highly forbidden 6S-7S transition, but one also needs a precise calibration procedure. The 1999 precision measurement by the Boulder group implied a 2.5 sigma deviation of Q\_w from the theoretical prediction. This triggered many particle physicist suggestions as well as examination by atomic theoretical physicists of several sources of corrections. After about three years the disagreement was removed without appealing to "New Physics". Concurrently, an original experimental approach was developed in our group for more than a decade. It is based on detection by stimulated emission with amplification of the left- right asymmetry. We present our decisive, recent progress together with our latest results. We emphasize the important impact for electroweak theory, of future measurements in cesium possibly pushed to the 0.1% level. Other possible approaches are currently explored in several atoms

Pilares mistos curtos de aço e concreto sob altas temperaturas

The growing demand for knowledge about the effect of high temperatures on structures has stimulated increasing research worldwide. This article presents experimental results for short composite steel and concrete columns subjected to high temperatures in ovens with or without an axial compression load, numerically analyzes the temperature distribution in these columns after 30 and 60 minutes and compares them with experimental results. The models consist of concrete-filled tubes of three different thicknesses and two different diameters, and the concrete fill has conventional properties that remained constant for all of the models. The stress-strain behavior of the composite columns was altered after exposure to high temperatures relative to the same columns at room temperature, which was most evident in the 60-minute tests due to the higher temperatures reached. The computational analysis adopted temperature rise curves that were obtained experimentally.A crescente demanda por conhecimento sobre a ação de altas temperaturas nas estruturas vem impulsionando pesquisas em todo o mundo. Este artigo tem por objetivo apresentar resultados experimentais de pilares mistos curtos de aço e concreto submetidos a altas temperaturas em fornos, com e sem ação de carregamento de compressão centrada, assim como analisar numericamente a distribuição da temperatura nesses pilares, nos tempos de 30 e 60 minutos e compará-los aos resultados experimentais. Os modelos adotados são tubos preenchidos com concreto, com três espessuras e dois diâmetros diferentes para os tubos, e o concreto de preenchimento com propriedades convencionais que se mantiveram constantes para todos os modelos. O comportamento força - deformação dos pilares mistos foi alterado após exposição à altas temperaturas em relação aos mesmos pilares em temperatura ambiente, sendo mais evidente nos ensaios de 60 minutos, os quais atingiram temperaturas mais elevadas. Na análise numérica adotaram-se curvas de elevação de temperatura que foram obtidas experimentalmente.530547Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Osteochondral transplantation using autografts from the upper tibio-fibular joint for the treatment of knee cartilage lesions

Purpose Treatment of large cartilage lesions of the knee in weight-bearing areas is still a controversy and challenging topic. Autologous osteochondral mosaicplasty has proven to be a valid option for treatment but donor site morbidity with most frequently used autografts remains a source of concern. This study aims to assess clinical results and safety profile of autologous osteochondral graft from the upper tibio-fibular joint applied to reconstruct symptomatic osteochondral lesions of the knee. Methods Thirty-one patients (22 men and 9 women) with grade 4 cartilage lesions in the knee were operated by mosaicplasty technique using autologous osteochondral graft from the upper tibio-fibular joint, between 1998 and 2006. Clinical assessment included visual analog scale (VAS) for pain and Lysholm score. All patients were evaluated by MRI pre- and post-operatively regarding joint congruency as good, fair (inferior to 1 mm incongruence), and poor (incongruence higher than 1 mm registered in any frame). Donor zone status was evaluated according to specific protocol considering upper tibio-fibular joint instability, pain, neurological complications, lateral collateral ligament insufficiency, or ankle complaints. Results Mean age at surgery was 30.1 years (SD 12.2). In respect to lesion sites, 22 were located in weight-bearing area of medial femoral condyle, 7 in lateral femoral condyle, 1 in trochlea, and 1 in patella. Mean follow-up was 110.1 months (SD 23.2). Mean area of lesion was 3.3 cm 2 (SD 1.7), and a variable number of cylinders were used, mean 2.5 (SD 1.3). Mean VAS score improved from 47.1 (SD 10.1) to 20.0 (SD 11.5); p = 0.00. Similarly, mean Lysholm score increased from 45.7 (SD 4.5) to 85.3 (SD 7.0); p = 0.00. The level of patient satisfaction was evaluated, and 28 patients declared to be satisfied/very satisfied and would do surgery again, while 3 declared as unsatisfied with the procedure and would not submit to surgery again. These three patients had lower clinical scores and kept complaints related to the original problem but unrelated to donor zone. MRI score significantly improved at 18–24 months comparing with pre-operative (p = 0.004). No radiographic or clinical complications related to donor zone with implication in activity were registered. Conclusions This work corroborates that mosaicplasty technique using autologous osteochondral graft from the upper tibio-fibular joint is effective to treat osteochondral defects in the knee joint. No relevant complications related to donor zone were registered