An adaptive typological approach to psychiatric screening.

Tested the feasibility of an adaptive typological approach to psychiatric screening using 9 MMPI code types as prototypal of more comprehensive systems of differential diagnosis. Ss were 1,350 White adult psychiatric outpatients (over 18 yrs of age) whose intake MMPIs fell within 1 of the 9 selected code types. Each code type was represented by 100 Ss in the developmental sample and 50 Ss in the cross-validational sample. Those 69 items that displayed the highest level of statistical difference in endorsement percentage between 2 and/or among several groups were used as predictor variables in a stepwise multiple discriminant-function analysis. The criterion was code type on the standard form. Results indicate that the percentage of correct classifications (when a case was classified into that code type for which he/she obtained the highest probability) was 61% after 30 items and rose to only 69% after 69 items. A variety of decision rules and cutoff points were applied to the data; all demonstrated (a) the ability to discriminate among the groups after the introduction of only 20–30 items into the stepwise program, and (b) the phenomenon of "diminishing returns" with the introduction of more items. There was a point relatively early in testing (30 items) at which it was possible to eliminate most groups from further consideration and beyond which it was counterproductive to introduce more items if one's aim was a 1st-level molar categorization. Implications for branched adaptive testing are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rapid Annealing in Silicon Transistors

Rapid annealing data after a pulse of reactor neutrons for seven NPN planar transistors at room temperature and the 2N1613 at various temperatures down to dry ice were interpreted in terms of the motion of a single type of mobile defect. An equation was derived for the recombination of the defect with fixed defects in a spherical cluster and the subsequent diffusion of the defect outside the cluster. This treatment leads to an identification of two stages of annealing, with a transition time between stages at room temperature of a few milliseconds. The variation in the transition time with temperature for the 2N1613 is used to derive an activation energy of (0.28 ± 0.02) eV, which agrees, within error, with that for the vacancy in p-type silicon. A calculation of the cluster radius is in reasonable agreement with one-half the primary recoil range.     

Essential nucleotide sequences and secondary structure elements of the hairpin ribozyme

In vitro selection experiments have been used to isolate active variants of the 50 nt hairpin catalytic RNA motif following randomization of individual ribozyme domains and intensive mutagenesis of the ribozyme-substrate complex. Active and inactive variants were characterized by sequencing, analysis of RNA cleavage activity in cis and in trans, and by substrate binding studies. Results precisely define base-pairing requirements for ribozyme helices 3 and 4, and identify eight essential nucleotides (G8, A9, A10, G21, A22, A23, A24 and C25) within the catalytic core of the ribozyme. Activity and substrate binding assays show that point mutations at these eight sites eliminate cleavage activity but do not significantly decrease substrate binding, demonstrating that these bases contribute to catalytic function. The mutation U39C has been isolated from different selection experiments as a second-site suppressor of the down mutants G21U and A43G. Assays of the U39C mutation in the wild-type ribozyme and in a variety of mutant backgrounds show that this variant is a general up mutation. Results from selection experiments involving populations totaling more than 10(10) variants are summarized, and consensus sequences including 16 essential nucleotides and a secondary structure model of four short helices, encompassing 18 bp for the ribozyme-substrate complex are derived.     

The Peyer's patch high endothelial receptor for lymphocytes, the mucosal vascular addressin, is induced on a murine endothelial cell line by tumor necrosis factor-alpha and IL-1

The specificity of lymphocyte homing from the blood into a tissue is determined in part by complementary pairs of adhesion receptors on lymphocytes and endothelial cells termed homing receptors and vascular addressins, respectively. The mucosal vascular addressin involved in lymphocyte homing to Peyer's patches is a 66-kDa glycoprotein, MAdCAM-1. Investigation of the regulation and molecular genetics of MAdCAM-1 have been hampered by the lack of a murine cell line expressing this adhesion molecule. We show herein using indirect immunofluorescence studies that MAdCAM-1 can be induced on a murine endothelial cell line, bEnd.3, by cytokines and LPS. Western blot analysis of MAdCAM-1 purified by affinity column chromatography from TNF-alpha-treated bEnd.3 cells demonstrates a 66-kDa protein that comigrates in SDS-PAGE with the MAdCAM-1 constitutively found on high endothelial venules in murine mesenteric lymph nodes. Comparison of MAdCAM-1 expression on the bEnd.3 cells was made to the expression of adhesion molecules ICAM-1 and VCAM-1. MAdCAM-1 and VCAM-1 are not constitutively expressed on the bEND.3 surface but can be induced in a concentration-dependent manner by LPS, TNF-alpha, and IL-1. ICAM-1 is constitutively expressed on the endothelioma surface and expression is increased by TNF-alpha, IL-1, LPS, and IFN-gamma. Surface expression of MAdCAM-1 peaks 12 to 18 h after exposure to TNF-alpha and remains elevated at 48 h, whereas expression of VCAM-1 peaks at 4 h and inducible ICAM-1 peaks between 4 and 18 h. Interestingly, IFN-gamma has differential effects on expression of these three adhesion receptors. IFN-gamma alone induces VCAM-1 and enhances ICAM-1 expression, but does not induce MAdCAM-1. Furthermore, although, preincubation of bEND.3 cells with IFN-gamma modestly increases the induction of ICAM-1 and VCAM-1 in response to TNF-alpha and IL-1, it dramatically reduces the TNF-alpha, IL-1, and LPS-induced expression of MAdCAM-1. MAdCAM-1 on bEnd.3 cells is functional as the murine T lymphoma TK1, known to bind MAdCAM-1, also binds to TNF-alpha-stimulated endothelioma but not to unstimulated cells. This binding is blocked by the antibodies against MAdCAM-1 and against the alpha 4-chain of its integrin receptor, alpha 4 beta 7, on TK1 cells.(ABSTRACT TRUNCATED AT 400 WORDS)     

LOWER SILURIAN "HOT SHALES" IN JORDAN: A NEW DEPOSITIONAL MODEL

Data are presented from the Batra Formation (also known as the Mudawwara Shale Formation) of a core from well BG‐14 in the Batna el Ghoul area, southern Jordan, which enable a new depositional model to be proposed for the middle Rhuddanian (lower Llandovery, Silurian) “hot shale” which may be applicable to other Arabian and North African “hot shales” of similar stratigraphical age. This “hot shale” probably results from rapid early burial of organic carbon associated with a minor regression during which anoxic bottom conditions were maintained for most, but not all, of the time. Evidence for regression comes from (1) increased sediment grain size within the “hot shale” by comparison with underlying shales; (2) palynological changes including a decrease in acritarch species diversity; an increase in the relative abundance of sphaeromorphs, veryhachiids with three processes and acritarchs with short, simple processes; and a decrease in the relative abundance of acanthomorphs; (3) a positive δ¹³C_org excursion (other Late Ordovician and Silurian positive δ¹³C_org excursions occur during regressions); and (4) very brief intervals of oxygenation (associated with sediment influx) reflected in the preservation of graptolites as three‐dimensional pyrite internal moulds, rather than as flattened periderm. The minor regression reflects a eustatic sea‐level fall, evidence for which has recently been presented from several regions, including Arctic Canada, Bohemia and Scotland. The BG‐14 “hot shale” is shown to be thicker than estimated in previous studies. Previous TOC measurements from the upper part of the “hot shale” were affected by the weathering of overlying strata in the BG‐14 core. ICP‐MS measurements show that uranium content is high in these weathered levels, extending the stratigraphical extent of the “hot shale” interval into the middle Rhuddanian. Depositional models such as that presented here rely on a robust biostratigraphical framework; in the Ordovician and Silurian of Arabia and North Africa, this can be provided by graptolites and chitinozoans.     

Evaluating rock mass disturbance within open-pit excavations using seismic methods: A case study from the Hinkley Point C nuclear power station

Understanding rock strength is essential when undertaking major excavation projects,as accurate assessments ensure both safe and cost-effective engineered slopes.Balancing the cost-safety trade-off becomes more imperative during the construction of critical infrastructure such as nuclear power stations,where key components are built within relatively deep excavations.Designing these engineered slopes is reliant on rock strength models,which are generally parameterised using estimates of rock properties(e.g.unconfined compressive strength,rock disturbance) measured prior to the commencement of works.However,the physical process of excavation weakens the remaining rock mass.Therefore,the model also requires an adjustment for the anticipated rock disturbance.In practice,this parameter is difficult to quantify and as a result it is often poorly constrained.This can have a significant impact on the final design and cost of excavation.We present results from passive and active seismic surveys,which image the extent and degree of disturbance within recently excavated slopes at the construction site of Hinkley Point C nuclear power station.Results from active seismic surveys indicate that the disturbance is primarily confined to 0.5 m from the excavated face.In conjunction,passive monitoring is used to detected seismic events corresponding to fracturing on the cm-scale and event locations are in agreement with 0.5 m of disturbance into the rock face.This suggests rock disturbance at this site is relatively low and occurred during and immediately after the excavation.A ratio of seismic velocities recorded before and after excavations are used to determine the disturbance parameter required for the Hoek-Brown rock failure criterion,and we assess that rock disturbance is low with the magnitude of the disturbance diminishing more quickly than expected into the excavated slope.Seismic methods provide a low-cost and quick method to assess excavation related rock mass disturbance,which can lead to cost reductions in large excavation projects.