Contingent time off to increase verbal behavior: A case report.

Describes the case of a withdrawn adolescent male outpatient at a mental health clinic who was instructed to record his own verbal behavior. Consequences were implemented to increase the frequency of verbal responses. S "earned" his way out of the clinic by increasing his verbal behavior to an established criterion performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Validity of the 16 PF and the MMPI in a mental hospital setting.

Administered the MMPI and 16 PF to 201 15-60 yr. old new admissions to a state mental hospital. Correlations between the 2 sets of scale scores were examined directly and by factor analysis. 3 common factors appeared to be represented to some extent in both instruments. The 16 PF appeared weak in the measurement of the more serious kinds of psychopathology, and had strongest loadings in a common factor identified with the validity scales of the MMPI. The 16 PF was found to measure 3 higher-order factors of personality not represented in the MMPI, but they do not appear highly relevant for assessment in a disturbed mental hospital population. Numerous significant relationships to psychiatrically relevant background variables were identified in analyses of profiles derived from both instruments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fracture toughness: A rationalization of the role of microstructure in an α-β titanium alloy

The role of microstructure in affecting fracture toughness is examined by considering how microstructure affects the formation of a critical increment of crack extension leading to catastrophic fracture. It is proposed that this critical increment of crack extension occurs by void formation ahead of the main crack and growth back to it. Factors affecting void nucleation and void growth are, therefore, examined in this connection. Published data on the Ti-5.25Al-5.5V-0.9Fe-0.5Cu alloy are used for this purpose. In equiaxed(E) α structure voids nucleate at Eα/agedβ matrix interfaces for both tensile and fracture toughness tests. Although the interparticle spacing, A, is four times more effective than priorβ grain size,D _β, in controlling void growth rate,G _L, in a tensile test,D _β is at least five times more effective in controlling fracture toughness. For Widmanstätten plus grain boundary (W + GB) α structures there are marked similarities betweenG _Lbehavior as a function of GBa thickness, J, and the contribution of J to fracture toughness. These similarities have led to the proposal that the increase in fracture toughness, ΔK_Q, with increasingl is due to blunting of the crack tip, and the plateau in ΔK_Q which follows, with increasingl, is due to a balance between blunting and sharpening processes. Blunting occurs by crack penetration into GBα. The sharpening occurs by void formation and growth along GBα/agedβ interfaces back to the main crack.     

Observation room windows.

Presents general criteria for observation room windows. Various glazing materials available for proper lighting and the typical transmission and reflection characteristics of each, acoustical factors relating to sound control, and general design considerations are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The aging behavior of orthorhombic marten site in Ti-6-2-4-6

In Ti-6-2-4-6 alloys, beta transforms to orthorhombic martensite when quenched from a temperature of 1188 or above, X-ray analysis showed that aging at 773 or 873 gradually reduces the degree of orthorhombicity until a hexagonal structure equivalent to alpha, but having the morphological characteristics of the prior martensite, is produced. The orthorhombicity is reduced by solute rejection to beta which forms as particles both homogeneously and heterogeneously within the martensitic structure. The structure at maximum hardness is a fine distribution of Burger’s oriented beta particles in a matrix of martensite of greatly reduced orthorhombicity. Overaging appears to occur as a result of coarsening of the homogeneous beta particles. It is shown that aging at temperatures from 873 to 1083 K results in growth of one particular varient of the beta which is located at the interface between twin related regions composing a martensite lath. This beta along with similarly oriented beta at lath interfaces forms a continuous beta matrix by a gradual growth process. It is shown that this matrix has the identical orientation and shape of the original beta grain prior to quenching. A mechanism is proposed to account for this “memory effect”.     

Retention of antioxidants in polyethylene by silane coupling agents

Antioxidant additives in polyethylene films have been shown to diffuse to the surface where they are subsequently lost, exposing the polymer to oxidation. Compatibility of antioxidants with polyethylene may be increased by use of silane coupling agents. In this study, three approaches to antioxidant modification are examined: (1) bonding antioxidant directly to silicon, (2) coupling the silane to an antioxidant hydroxyl function, and (3) dissolving antioxidants in silanes. All three approaches are shown to be effective in reducing antioxidant loss by diffusion.     

Prediction of the structures of proteins with the UNRES force field, including dynamic formation and breaking of disulfide bonds

The presence of disulfide bonds is essential for maintaining the structure and function of many proteins. The disulfide bonds are usually formed dynamically during folding. This process is not accounted for in present algorithms for protein-structure prediction, which either deduce the possible positions of disulfide bonds only after the structure is formed or assume fixed disulfide bonds during the course of simulated folding. In this work, the conformational space annealing (CSA) method and the UNRES united-residue force field were extended to treat dynamic formation of disulfide bonds. A harmonic potential is imposed on the distance between disulfide-bonded cysteine side-chain centroids to describe the energetics of bond distortion and an energy gain of 5.5 kcal/mol is added for disulfide-bond formation. Formation, breaking and rearrangement of disulfide bonds are included in the CSA search by introducing appropriate operations; the search can also be carried out with a fixed disulfide-bond arrangement. The algorithm was applied to four proteins: 1EI0 (alpha), 1NKL (alpha), 1L1I (beta-helix) and 1ED0 (alpha + beta). For 1EI0, a low-energy structure with correct fold was obtained both in the runs without and with disulfide bonds; however, it was obtained as the lowest in energy only with the native disulfide-bond arrangement. For the other proteins studied, structures with the correct fold were obtained as the lowest (1NKL and 1L1I) or low-energy structures (1ED0) only in runs with disulfide bonds, although the final disulfide-bond arrangement was non-native. The results demonstrate that, by including the possibility of formation of disulfide bonds, the predictive power of the UNRES force field is enhanced, even though the disulfide-bond potential introduced here rarely produces disulfide bonds in native positions. To the best of our knowledge, this is the first algorithm for energy-based prediction of the structure of disulfide-bonded proteins without any assumption as to the positions of native disulfides or human intervention. Directions for improving the potentials and the search method are suggested.     

Recent changes in platinum group element concentrations and osmium isotopic composition in sediments from an urban lake

Automobile catalyst emissions have resulted in the occurrence of elevated Pt, Pd, and Rh concentration in the urban and roadside environment. We investigate the chronology of platinum group elements (PGE) accumulation in dated sediments from an urban lake near Boston, MA. Chronological profiles demonstrate that Pt, Pd, and Rh concentrations increased following the introduction in catalysts with accumulation rates 6-16 times larger in 1992-2002 than prior to the introduction of catalysts. Ratios of these elements closely match their ratios in catalysts, providing further evidence of an automobile source. Iridium and Ru accumulation in sediments also increased following the introduction of catalysts, and while past Os contamination is associated with leather tanning, recent changes in the isotopic composition of Os indicate another anthropogenic source for this element. The PGE have similar geochemical properties and are difficult to separate from one another, and therefore, we suggest that automobile catalyst emissions also result in increasing environmental concentrations of Ir, Ru, and Os, which occur as impurities in catalysts. An automobile catalyst source of Ir and Os is supported by elevated concentrations of these elements in a tunnel dust sample.     

Extracellular recordings from patterned neuronal networks using planar microelectrode arrays

Neuronal cell networks have been reconstructed on planar microelectrode arrays (MEAs) from dissociated hippocampal pyramidal neurons. Microcontact printing (microCP) and a photoresist-liftoff method were used to selectively localize poly-L-lysine (PLL) on the surface of MEAs. Haptotaxis led to the organization of the neurons into networks localized adjacent to microelectrodes. Various grids of PLL with 2-25-microm-wide lines spaced by 50-200 microm with 15-25-microm nodes at intersection points were used to guide cell body attachment and neurite outgrowth. Bursting activity with spike amplitude attenuation was observed, and multichannel recordings detected instances of coincident firing activity. Finally, we present here an extracellular recording from a approximately 2 microm bundle of guided neurites.