A cognitive stress-reduction intervention program for adolescents.

We examined the effectiveness of a cognitive intervention to help adolescents cope with stress and other forms of negative emotional arousal. Through this intervention procedure, youths learned how to identify and monitor stress-promoting cognitions, restructure these cognitions into more adaptive thoughts, use self-instructions to control stress-engendering self-statements, and practice and apply these acquired skills. The youths who received training were compared to a waiting list control group on measures of anxiety, anger, self-esteem, depression, and self-reports of cognitions in hypothetical stress situations. The training group showed significant reductions in levels of anxiety and anger, improvement in self-esteem, and an increase in the number of reported positive cognitions in response to a hypothetical situation. These treatment gains were maintained at a 10-week follow-up. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Anode Interfacial Tuning via Electron‐Blocking/Hole‐Transport Layers and Indium Tin Oxide Surface Treatment in Bulk‐Heterojunction Organic Photovoltaic Cells

The effects of anode/active layer interface modification in bulk‐heterojunction organic photovoltaic (OPV) cells is investigated using poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and/or a hole‐transporting/electron‐blocking blend of 4,4′‐bis[(p‐trichlorosilylpropylphenyl)‐phenylamino]biphenyl (TPDSi₂) and poly[9,9‐dioctylfluorene‐co‐N‐[4‐(3‐methylpropyl)]‐diphenylamine] (TFB) as interfacial layers (IFLs). Current–voltage data in the dark and AM1.5G light show that the TPDSi₂:TFB IFL yields MDMO‐PPV:PCBM OPVs with substantially increased open‐circuit voltage (V_oc), power conversion efficiency, and thermal stability versus devices having no IFL or PEDOT:PSS. Using PEDOT:PSS and TPDSi₂:TFB together in the same cell greatly reduces dark current and produces the highest V_oc (0.91 V) by combining the electron‐blocking effects of both layers. ITO anode pre‐treatment was investigated by X‐ray photoelectron spectroscopy to understand why oxygen plasma, UV ozone, and solvent cleaning markedly affect cell response in combination with each IFL. O₂ plasma and UV ozone treatment most effectively clean the ITO surface and are found most effective in preparing the surface for PEDOT:PSS deposition; UV ozone produces optimum solar cells with the TPDSi₂:TFB IFL. Solvent cleaning leaves significant residual carbon contamination on the ITO and is best followed by O₂ plasma or UV ozone treatment.     

Intergroup relations and group solidarity: Effects of group identification and social beliefs on depersonalized attraction.

An intergroup extension of M. A. Hogg's (1992, 1993) social attraction hypothesis is proposed. Netball teams were investigated with measures assessing the relationship between (a) objective status; (b) "social beliefs" about intergroup status, stability, legitimacy, and permeability; (c) group identification, self-categorization, and prototypicality; (d) interpersonal relations and similarity; (e) depersonalized social attraction; and (f) true personal attraction. As predicted, group-membership based social attraction was directly influenced by self-categorization; indirectly influenced, through self-categorization, by intergroup status and stability beliefs; and uninfluenced by interpersonal relations. Social attraction (related to prototypicality and group identification) was relatively independent of personal attraction (related to similarity and interpersonal variables). Legitimacy, permeability, and the empirical co-occurrence of social and personal attraction in cohesive groups are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low series resistance high-efficiency GaAs/AlGaAs vertical-cavity surface-emitting lasers with continuously graded mirrors grown by MOCVD

GaAs/AlGaAs vertical-cavity top-surface-emitting lasers (VCSELs) with a continuously graded mirror composition have been grown by MOCVD, and planar devices with proton-implant current confinement have been characterized. Continuous grading of the heterointerfaces in the Bragg reflectors eliminated the energy-band discontinuities, thus improving carrier transport and resulting in a substantial reduction in the series resistance and threshold voltage of the laser diodes. These VCSELs have excellent room-temperature CW electrical characteristics, including some of the lowest series resistances, highest power efficiencies and lowest operating voltages ever reported.<>     

Molecular motion in polystyrene-plasticizer systems as studied by dielectric relaxation

The dielectric relaxation behaviour of mixtures of polystyrene with the glass-forming liquids di-n-butyl phthalate, tri-tolyl phosphate and di-octyl phthalate, has been studied over a wide range of compositions. Three distinct dipole relaxation processes are observed, the α process being due to the reorientation of solvent molecules as modified by the polymer molecules in the environment, the α″ process is due to the motion of solvent molecules in cooperation with, and largely determined by, the motion of the polymer molecules, and the α′ process is due to the partial re-orientation of solvent molecules. A comparison is made between the behaviour of these systems and of pure solid dipolar polymers and of supercooled molecular liquids.     

Very low threshold current density room temperature continuous-wavelasing from a single-layer InAs quantum-dot laser

Continuous-wave (CW) lasing operation with a very low threshold current density (J_th=32.5 A/cm²) has been achieved at room temperature by a ridge waveguide quantum-dot (QD) laser containing a single InAs QD layer embedded within a strained InGaAs quantum well (dot-in-well, or DWELL structure). Lasing proceeds via the QD ground state with an emission wavelength of 1.25 μm when the cavity length is longer than 4.2 mm. For a 5-mm long QD laser, CW lasing has been achieved at temperatures as high as 40°C, with a characteristic temperature T₀ of 41 K near room temperature. Lasers with a 20 μm stripe width have a differential slope efficiency of 32% and peak output power of >10 mW per facet (uncoated)     

The still-face effect in Chinese and Canadian 3- to 6-month-old infants

Both green and black tea have been shown to inhibit lung tumorigenesis in laboratory animal experiments. Green tea inhibited N-nitrosodiethylamine-induced lung tumor incidence and multiplicity in female A/J mice when tea was given either during the carcinogen treatment period or during the post-carcinogen treatment period. In a separate tumorigenesis model, both decaffeinated black tea and decaffeinated green tea inhibited 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumor formation. Studies in which tea was administered during different time periods in relation to the NNK suggest that tea can inhibit lung tumorigenesis at both the initiation and promotion stages. The antiproliferative effects of tea may be responsible for these anti-carcinogenic actions. Black tea polyphenol preparations decreased NNK-induced hyperproliferation. Black tea also inhibited the progression of pulmonary adenomas to adenocarcinomas and the formation of spontaneous lung tumors in A/J mice. Growth inhibition by various tea polyphenols has been demonstrated in human lung H661 and H1299 cells. Although inhibition of cell growth and signal transduction pathways by tea components have been demonstrated, the concentrations required to produce the effect are higher than achievable in tissues in vivo. More research is necessary to translate these laboratory results to applications in human chemoprevention.     

Inverting and latching optical logic gates based on the integrationof vertical-cavity surface-emitting lasers and photothyristors

Inverting optical logic gates based on the monolithic integration of a vertical-cavity surface-emitting laser (VCSEL) with a heterojunction photothyristor (PNPN) are described. Logic functions INVERT, NAND, and NOR are experimentally demonstrated for the first time using latchable and cascadable PNPN/VCSEL switches, which can be triggered with very low optical energy, while producing high optical gain and optical contrast. These gates are integrable on a single epitaxial structure to provide multifunctional logic and memory arrays     

Efficient continuous-wave lasing operation of a narrow-stripeoxide-confined GaInNAs-GaAs multiquantum-well laser grown by MOCVD

Efficient continuous-wave lasing operation has been achieved above room temperature by a triple-quantum-well GaInNAs-GaAs laser diode grown on a 6°-misoriented GaAs substrate by MOCVD. Using a planar, oxide-confined, narrow-stripe (8 μm) laser geometry, continuous-wave lasing operation was achieved over a wide range of temperatures up to 57°C. At room temperature, lasing occurs at a wavelength of 1.16 μm, with a high single-facet slope efficiency of 25% and a threshold current density of 1.3 kA/cm²     

Oxide-confined monolithic, multiple-wavelength vertical-cavitysurface-emitting laser arrays with a 40-nm wavelength span

Monolithic, multiple-wavelength, vertical-cavity surface-emitting laser arrays grown by controlling the metal-organic chemical vapor deposition epitaxial growth rate on a patterned substrate, and using selective oxidation for current confinement, have been demonstrated with a periodic, graded wavelength span of 40 nm, Near room-temperature, electrically pumped continuous-wave lasing is achieved over the entire 40-nm range, with uniform threshold currents of 4.5 mA±1.0 mA, and with output powers ranging from 0.4-1.3 mW