Emotional and sensory focus as mediators of dental pain among patients differing in desired and felt dental control.

Giving patients instructions to focus on sensory (vs emotional) stimuli during a root canal procedure significantly reduced self-reported pain, but only among patients who were classified as having strong desire for control and low felt control in dental situations. Among patients with low felt control and low desire for control, sensory-focus instructions produced greater pain reports than did emotion-focus instructions. Finally, high desire–low felt patients reported higher levels of expected pain before treatment than did other patient subgroups. These data suggested limiting conditions for H. Leventhal's (1982) theory of emotion and supported the idea that desire for control might moderate the effects of perceived control. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On mind &; Turing’s machines

Turing’s notion of human computability is exactly right not only for obtaining a negative solution of Hilbert’s Entscheidungsproblem that is conclusive, but also for achieving a precise characterization of formal systems that is needed for the general formulation of the incompleteness theorems. The broad intellectual context reaches back to Leibniz and requires a focus on mechanical procedures; these procedures are to be carried out by human computers without invoking higher cognitive capacities. The question whether there are strictly broader notions of effectiveness has of course been asked for both cognitive and physical processes. I address this question not in any general way, but rather by focusing on aspects of mathematical reasoning that transcend mechanical procedures.Section 1 discusses Gödel’s perspective on mechanical computability as articulated in his [193?], where he drew a dramatic conclusion from the undecidability of certain Diophantine propositions, namely, that mathematicians cannot be replaced by machines. That theme is taken up in the Gibbs Lecture of 1951; Gödel argues there in greater detail that the human mind infinitely surpasses the powers of any finite machine. An analysis of the argument is presented in Section 2 under the heading Beyond calculation. Section 3 is entitled Beyond discipline and gives Turing’s view of intelligent machinery; it is devoted to the seemingly sharp conflict between Gödel’s and Turing’s views on mind. Their deeper disagreement really concerns the nature of machines, and I’ll end with some brief remarks on (supra-) mechanical devices in Section 4.     

Deep levels in p- and n-type InGaAsN for high-efficiency multi-junction III–V solar cells

DLTS measurements have been performed on InGaAsN. Four hole traps have been identified in 1.05 eV, p-type InGaAsN and the removal of a midgap trap (0.5 eV) during annealing has been correlated with improved bulk material properties. Improvements in MOCVD growth conditions resulted in a reduction of trap density in 1.05 eV, p-type InGaAsN. Increased indium and nitrogen composition has been correlated with higher defect concentrations in p-type InGaAsN. Two electron traps have been identified in 1.15 eV, n-type InGaAsN and annealing was found to reduce the density of the shallow electron trap.     

Mesenteric cysts: rare cause of abdominal pain

For about two years a now 47-year-old woman had been suffering from heartburn, diarrhoea and constipation, at times also abdominal colic and a pressure sensation in the right lower abdomen. Physical examination and biochemical tests were according to age, except for an raised erythrocyte sedimentation rate of 25/50 mm. Ultrasound revealed an intraperitoneal echo-free multi-chambered structure, 11 x 5 x 2 cm, with dorsally increased echo density and smooth entry echo, apparently arising from the mesentery. Computed tomography confirmed these findings and at laparoscopy a cyst, 12 x 8 x 5 cm, was identified. It was filled with yellow clear fluid and arose from the mesentery of the ascending colon. The cyst was scooped out surgically. Histological examination showed a single-layered mesothelial coat. The postoperative course was unremarkable. At re-examination 8 months later the patient had remained symptom-free.     

Specific inhibition of granzyme B by parainfluenza virus type 3

T-cell-mediated cytotoxicity is an important means of defense against viral pathogens; however, several viruses possess mechanisms to disrupt cytotoxicity, thereby allowing them to avoid immune clearance. These viruses have been shown to inhibit cytotoxicity by interfering with the capacity of T lymphocytes to specifically recognize infected cells. An alternative mechanism for virally induced cytotoxic dysfunction is identified in this report. We show that parainfluenza virus type 3, a negative-stranded RNA virus, can inhibit cytotoxicity by causing a defect in the cytotoxic effector apparatus. This defect is identified as a selective inhibition of granzyme B mRNA.     

Scanning force microscopy studies of GaAs films grown on offcut Ge substrates

The surface morphology of GaAs films grown on offcut Ge substrates is studied using a scanning force microscope (SFM). We investigated the effects of the Ge buffer layer, growth temperature, film thickness, and prelayer on the GaAs surface morphology. The starting Ge substrates are offcut 6° toward the [110] direction to minimize single steps on the substrates before molecular beam epitaxial film growth. We find that comparing with GaAs samples grown without Ge buffer layers or with unannealed Ge buffer layers, samples with annealed Ge buffer layers are much smoother and contain no antiphase boundaries (APBs) on the surface. For thick (≥1 μm) GaAs films with an annealed Ge buffer layer, the surfaces display crosshatch lines and elongated mounds (along , which are associated with the substrate offcut direction. As the film thickness increases, the crosshatch lines become shorter, denser and rougher, and the mounds grow bigger (an indication of GaAs homoepitaxial growth). We conclude that annealed Ge buffer layers are crucial for growing high quality GaAs films with few APBs generated during the growth. In addition, under optimal conditions, different prelayers make little difference for thick GaAs films with annealed Ge buffer layers.     

Anti-phase domain-free growth of GaAs on offcut (001) Ge wafers by molecular beam epitaxy with suppressed Ge outdiffusion

The nucleation and growth of GaAs films on offcut (001) Ge wafers by solid source molecular beam epitaxy (MBE) is investigated, with the objective of establishing nucleation conditions which reproducibly yield GaAs films which are free of antiphase domains (APDs) and which have suppressed Ge outdiffusion into the GaAs layer. The nucleation process is monitored by in-situ reflection high energy electron diffraction and Auger electron spectroscopy. Several nucleation variables are studied, including the state of the initial Ge surface (single-domain 2×1 or mixed-domain 2×1:1×2), the initial prelayer (As, Ga, or mixed), and the initial GaAs growth temperature (350 or 500°C). Conditions are identified which simultaneously produce APD-free GaAs layers several microns in thickness on Ge wafers with undetectable Ge outdiffusion and with surface roughness equivalent to that of GaAs/GaAs homoepitaxy. APD-free material is obtained using either As or Ga nucleation layers, with the GaAs domain dependent upon the initial exposure chemical species. Key growth steps for APD-free GaAs/Ge growth by solid source MBE include an epitaxial Ge buffer deposited in the MBE chamber to bury carbon contamination from the underlying Ge wafer, an anneal of the Ge buffer at 640°C to generate a predominantly double atomic-height stepped surface, and nucleation of GaAs growth by a ten monolayer migration enhanced epitaxy step initiated with either pure As or Ga. We identify this last step as being responsible for blocking Ge outdiffusion to below 10¹⁵ cm⁻³ within 0.5 microns of the GaAs/Ge interface.     

A new concept in vegetable oil refining automation

Journal of the American Oil Chemists' Society -