7,105 research outputs found

    The Prehistoric Sites at Choke Canyon Reservoir, Southern Texas: Results of Phase II Archaeological Investigations

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    Reported in this volume are the results of archaeological investigations at 72 prehistoric sites located in the basin of Choke Canyon Reservoir on the Frio River in Live Oak and McMullen Counties, southern Texas. The sites investigated in this study will be affected in one way or another by a lake formed after construction of Choke Canyon Dam, a project of the United States Bureau of Reclamation CUSBR). The research was sponsored by the USBR as the second and final phase of a two-stage program of archaeological investigations designed to mitigate damage or destruction of cultural resources resulting from dam construction and subsequent long-term inundation of a large area of the Frio River valley. Methods used to study Choke Canyon\u27s prehistoric sites during the Phase II investigation were various types of subsurface excavations, documentation of surface features and characteristics, and collection of artifacts from site surfaces. The people who inhabited the Choke Canyon region in prehistoric times, representing an approximate span of 10,000 years, existed as mobile hunter/gatherer bands. They subsisted by tapping virtually every conceivable source of edible natural food. A full spectrum of animals, from lowly field mice and lizards up to bison and deer, was exploited by various techniques of hunting, trapping, and catching. Large land snails and mussels were sources of meat food that Choke Canyon\u27s prehistoric people could easily gather. Gar, drum, and turtles were taken from local creeks, sloughs, and the river, perhaps using spears, nets, or weirs. Analysis of vertebrate faunal remains, results of which are presented herein, rather conclusively demonstrates that Late Prehistoric people exploited big game species more commonly than did their Archaic period predecessors. Floral products must also have comprised a substantial portion of the foods consumed by Choke Canyon\u27s prehistoric inhabitants. Direct evidence of plant food utilization is nonexistent on the sites. However, the very common occurrence of sandstone manes and metates implies heavy reliance on seeds, nuts, or beans. Also, the tremendous amount of burned rock that accumulated in Archaic components at many sites, often found as very carefully constructed hearth features, suggests that baking or roasting activities were extremely common. Roots, tubers, stalks, and other edible plant parts may have been what was being prepared in these facilities. Diagnostic artifacts recovered from prehistoric sites at Choke Canyon during the various phases of archaeological investigation clearly indicate that the general vicinity witnessed aboriginal activity from Paleo-Indian times up through the early Historic period. Evidence of Paleo-Indian people is limited to surface finds along the valley margin and on high, ancient terrace formations down in the river valley. No in situ subsurface Paleo-Indian components have yet been isolated at Choke Canyon. Where previously the earliest subsurface component known at Choke Canyon dated to the Middle Archaic period (ca. 3400 B.C. to 2400 B.C.), the Phase II excavations led to discovery of an Early Archaic component dating to the period from 5000 B.C. xi to 4000 B.C. While recognizable Paleo-Indian, Early Archaic, and Middle Archaic components are relatively scarce, the Late Archaic and Late Prehistoric periods are amply represented in the prehistoric sites at Choke Canyon. Phase II investigations also produced the first clear indication of an aboriginal component containing evidence of contact with Anglo-Europeans in early historic times. The bulk of cultural, paleobotanical, and vertebrate faunal data representing the prehistory of Choke Canyon indicates that floral and faunal communities and the general climatic regime remained essentially unchanged from at least 4000 B.C. up to the period in historic times when certain livestock and land management practices led to a drastic expansion of brush communities and severe erosion of formerly stable land surfaces

    Auditory Phenotypic Variability in Friedreich's Ataxia Patients

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    Auditory neural impairment is a key clinical feature of Friedreich's Ataxia (FRDA). We aimed to characterize the phenotypical spectrum of the auditory impairment in FRDA in order to facilitate early identification and timely management of auditory impairment in FRDA patients and to explore the relationship between the severity of auditory impairment with genetic variables (the expansion size of GAA trinucleotide repeats, GAA1 and GAA2), when controlled for variables such as disease duration, severity of the disease and cognitive status. Twenty-seven patients with genetically confirmed FRDA underwent baseline audiological assessment (pure-tone audiometry, otoacoustic emissions, auditory brainstem response). Twenty of these patients had additional psychophysical auditory processing evaluation including an auditory temporal processing test (gaps in noise test) and a binaural speech perception test that assesses spatial processing (Listening in Spatialized Noise-Sentences Test). Auditory spatial and auditory temporal processing ability were significantly associated with the repeat length of GAA1. Patients with GAA1 greater than 500 repeats had more severe auditory temporal and spatial processing deficits, leading to poorer speech perception. Furthermore, the spatial processing ability was strongly correlated with the Montreal Cognitive Assessment (MoCA) score. To our knowledge, this is the first study to demonstrate an association between genotype and auditory spatial processing phenotype in patients with FRDA. Auditory temporal processing, neural sound conduction, spatial processing and speech perception were more severely affected in patients with GAA1 greater than 500 repeats. The results of our study may indicate that auditory deprivation plays a role in the development of mild cognitive impairment in FRDA patients

    Has the regulation of non-GAAP disclosures influenced managers' use of aggressive earnings exclusions?

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    The frequency of non-GAAP (“pro forma”) reporting has continued to increase in the U.S. over the last decade despite preliminary evidence that regulatory intervention led to a decline in non-GAAP disclosures. In particular, the Sarbanes-Oxley Act of 2002 (SOX) and Regulation G (2003) impose strict requirements related to the reporting of non-GAAP numbers. More recently, the SEC has renewed its emphasis on non-GAAP reporting and declared it a “fraud risk factor.” Given the SEC’s renewed emphasis on non-GAAP disclosures, we explore the extent to which regulation has curbed potentially misleading disclosures by investigating two measures of aggressive non-GAAP reporting. Consistent with the intent of Congress and the SEC, we find some evidence that managers report adjusted earnings metrics more cautiously in the post-SOX regulatory environment. Specifically, the results suggest that firms reporting non-GAAP earnings in the post-SOX period are less likely to (1) exclude recurring items incremental to those excluded by analysts and (2) use non-GAAP exclusions to meet strategic earnings targets on a non-GAAP basis that they miss based on I/B/E/S actual earnings. However, we also find that some firms exclude specific recurring items aggressively. Overall, the results suggest that while regulation has generally reduced aggressive non-GAAP reporting, some firms continue to disclose non-GAAP earnings numbers that could be misleading in the post-SOX regulatory environment

    Lexical evolution rates by automated stability measure

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    Phylogenetic trees can be reconstructed from the matrix which contains the distances between all pairs of languages in a family. Recently, we proposed a new method which uses normalized Levenshtein distances among words with same meaning and averages on all the items of a given list. Decisions about the number of items in the input lists for language comparison have been debated since the beginning of glottochronology. The point is that words associated to some of the meanings have a rapid lexical evolution. Therefore, a large vocabulary comparison is only apparently more accurate then a smaller one since many of the words do not carry any useful information. In principle, one should find the optimal length of the input lists studying the stability of the different items. In this paper we tackle the problem with an automated methodology only based on our normalized Levenshtein distance. With this approach, the program of an automated reconstruction of languages relationships is completed

    Multiple phosphorylation of the Cdc48/p97 cofactor protein Shp1/p47 occurs upon cell stress in budding yeast

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    The homohexameric p97 complex, composed of Cdc48 subunits in yeast, is a crucial component of protein quality control pathways including ER-associated degradation. The complex acts to segregate protein complexes in an ATP-dependent manner, requiring the engagement of cofactor proteins that determine substrate specificity. The function of different Cdc48 cofactors and how they are regulated remains relatively poorly understood. In this study, we assess the phosphorylation of Cdc48 adaptor proteins, revealing a unique and distinctive phosphorylation pattern of Shp1/p47 that changed in response to TORC1 inhibition. Site-directed mutagenesis confirmed that this pattern corresponded to phosphorylation at residues S108 and S315 of Shp1, with the double-phosphorylated form becoming predominant upon TORC1 inhibition, ER-stress, and oxidative stress. Finally, we assessed candidate kinases and phosphatases responsible for Shp1 phosphorylation and identified two regulators. We found that cells lacking the kinase Mpk1/Slt2 show reduced Shp1 phosphorylation, whereas impaired PP1 phosphatase catalytic subunit (Glc7) activity resulted in increased Shp1 phosphorylation. Overall, these findings identify a phosphoregulation of Shp1 at multiple sites by Mpk1 kinase and PP1 phosphatase upon various stresses

    The ribosome-associated chaperone Zuo1 controls translation upon TORC1 inhibition

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    Protein requirements of eukaryotic cells are ensured by proteostasis, which is mediated by tight control of TORC1 activity. Upon TORC1 inhibition, protein degradation is increased and protein synthesis is reduced through inhibition of translation initiation to maintain cell viability. Here, we show that the ribosome-associated complex (RAC)/Ssb chaperone system, composed of the HSP70 chaperone Ssb and its HSP40 co-chaperone Zuo1, is required to maintain proteostasis and cell viability under TORC1 inhibition in Saccharomyces cerevisiae. In the absence of Zuo1, translation does not decrease in response to the loss of TORC1 activity. A functional interaction between Zuo1 and Ssb is required for proper translational control and proteostasis maintenance upon TORC1 inhibition. Furthermore, we have shown that the rapid degradation of eIF4G following TORC1 inhibition is mediated by autophagy and is prevented in zuo1Δ cells, contributing to decreased survival in these conditions. We found that autophagy is defective in zuo1Δ cells, which impedes eIF4G degradation upon TORC1 inhibition. Our findings identify an essential role for RAC/Ssb in regulating translation in response to changes in TORC1 signalling.</p

    The UK risk assessment scheme for all non-native species

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    1. A pest risk assessment scheme, adapted from the EPPO (European and Mediterranean Plant Protection Organisation) scheme, was developed to assess the risks posed to UK species, habitats and ecosystems by non-native taxa. 2. The scheme provides a structured framework for evaluating the potential for non-native organisms, whether intentional or unintentional introductions, to enter, establish, spread and cause significant impacts in all or part of the UK. Specialist modules permit the relative importance of entry pathways, the vulnerability of receptors and the consequences of policies to be assessed and appropriate risk management options to be selected. Spreadsheets for summarising the level of risk and uncertainty, invasive attributes and economic impact were created. In addition, new methods for quantifying economic impact and summarising risk and uncertainty were explored. 3. Although designed for the UK, the scheme can readily be applied elsewhere

    Observational tests of interstellar methanol formation

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    Context. It has been established that the classical gas-phase production of interstellar methanol (CH3OH) cannot explain observed abundances. Instead it is now generally thought that the main formation path has to be by successive hydrogenation of solid CO on interstellar grain surfaces. Aims: While theoretical models and laboratory experiments show that methanol is efficiently formed from CO on cold grains, our aim is to test this scenario by astronomical observations of gas associated with young stellar objects (YSOs). Methods: We have observed the rotational transition quartets J = 2K - 1K of 12CH3OH and 13CH3OH at 96.7 and 94.4 GHz, respectively, towards a sample of massive YSOs in different stages of evolution. In addition, the J = 1-0 transitions of 12C18O and 13C18O were observed towards some of these sources. We use the 12C/13C ratio to discriminate between gas-phase and grain surface origin: If methanol is formed from CO on grains, the ratios should be similar in CH3OH and CO. If not, the ratio should be higher in CH3OH due to 13C fractionation in cold CO gas. We also estimate the abundance ratios between the nuclear spin types of methanol (E and A). If methanol is formed on grains, this ratio is likely to have been thermalized at the low physical temperature of the grain, and therefore show a relative over-abundance of A-methanol. Results: We show that the 12C/13C isotopic ratio is very similar in gas-phase CH3OH and C18O, on the spatial scale of about 40", towards four YSOs. For two of our sources we find an overabundance of A-methanol as compared to E-methanol, corresponding to nuclear spin temperatures of 10 and 16 K. For the remaining five sources, the methanol E/A ratio is less than unity. Conclusions: While the 12C/13C ratio test is consistent with methanol formation from hydrogenation of CO on grain surfaces, the result of the E/A ratio test is inconclusive
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