Staphylococcus aureus adhesion to different treated titanium surfaces

Staphylococcus aureus is a major pathogen, associated with medical-device related infections. Converting biomaterial surfaces into non-interactive surfaces requires a specific surface/interface design. One approach is to polish the surface, and a second is to coat the surface with an antimicrobial or protein resistant coating. This study showed that polishing a titanium surface or coating titanium with various treatments that decreased the surface's coefficient of friction, had no significant effect on minimising S. aureus adhesion to these surfaces under static conditions in comparison to standard medical grade titanium. The cell promoting coating, TAST, was found to increase the S. aureus density on its surface as expected. The only coating that significantly decreased the density of adhering S. aureus was the titanium surface coated with sodium hyaluronate. Thus such a coating could have potential use as a coating for ostoesynthesis, orthopaedic or dental implants.     

Effect of Grain Size on the Weldability of Cast Alloy 718

Electron beam welding was conducted on cast alloy 718 with varying grain sizes obtained using Microcast (MX™) and conventional cast (CC) techniques. The average value per section of Total Crack Length (Av. TCL) was measured on each cross section and used to represent the material's weldability. It was found for the first time that the grain size had a reduced effect on the weldability of cast alloys, relative to that reported in the literature for wrought alloys; i.e., increased grain size in the range of 90-3000 microns resulted in improved weldability. This was determined to be related to the probability of welds intersecting grain boundaries and causing grain boundary microfissuring. The conclusion from the experimental analysis is corroborated by the use of a Weibull-type analysis to evaluate the probability of a weld microfissure occurring relative to the grain size. As grain size increases, the probability of the weld intersecting the grains is reduced, and thus, the likelihood of microfissuring is reduced. With regard to a single crystal, there are no grain boundaries intercepting the weld (probability = 0), and thus, microfissuring related to constitutional liquation of primary carbides, or segregation of species to grain boundaries would not occur.     

Crisis intervention after the suicide of a teacher.

Educational institutions increasingly are requesting the services of mental health professionals after a suicide has occurred. Although such communities have sustained sudden shock and loss, the contagious quality of suicide results in uncertainty about the most appropriate response. We describe an intervention occurring after the suicide of an elementary school teacher. The intervention included a meeting with faculty, classroom discussions with the students most directly affected, and the availability of the school psychologist for individual meetings. In addition, a memorial service was held at the school. We argue that such a broad, multifaceted response contributes to the healing process and serves to minimize mental health difficulties after such an event. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hazard Rates and Generalized Beta Distributions

This paper considers the behavior of the hazard rates of the Generalized gamma, and beta of the first and second kind. The hazard functions include strictly decreasing, constant, strictly increasing, ? and ? shaped hazard rates. By considering the generalized distributions a unified development for such distributions as beta type 1, beta type 2, Burr types 3 and 12, power, Weibull, gamma, Lomax, Fisk, uniform, Rayleigh, and exponential are included as special cases. The results are conveniently summarized in three figures. The generalized distributions considered in this paper are seen to provide models for all of the different shaped hazard rates mentioned above. This flexibility permits the data to determine the nature of the hazard function without its being inadvertently imposed through the selection of an improper model. For example, the selection of a Weibull distribution permits a decreasing, constant, or increasing hazard rate, but not a ? or ? shaped one. The use of the generalized gamma or either of the generalized beta functions considered in section II does permit realization of these additional shapes for the hazard rate.     

Influence of Tannin on Phaseolus vulgaris Protein Digestibility and Quality

The influence of tannin on protein digestibility and quality of black beans was evaluated using an enzyme-Tetrahymena thermophila bioassay. In vitro digestibility and t-PER (Tetrahymena-based PER) were inversely related to tannin content. Bioavailability, expressed by Tetrahymena growth, of black bean globulin G₁ in the presence of black bean condensed tannins correlated well (r=0.95) with the in vitro digestibility of the protein. Black bean condensed tannins complexed readily with black bean globulin G₁ to form insoluble precipitates from pH 2.0 to pH 8.0. Bean tannin-G₁ precipitates, at tannin-to G₁ ratios of 0.55 or greater, were resistant to pepsin digestion at pH 2.0. Digestion of bean tannin-G₁ precipitates was 69–74% at pH 8.0, using a multienzyme system of trypsin, chymotrypsin and peptidase.     

Concentration dependence ofD,T 1, andT 2 for dilute solutions of3He in solid4He

Measurements of the spin diffusion coefficientD and NMR relaxation timesT ₁ andT ₂ are reported for dilute solutions of³He in solid⁴He at two molar volumes, 20.95 and 20.7 cm³. The weakly interacting impuriton model, for whichD ^–1 is proportional to impurity concentration, is observed only at fractional impurity concentrationx ₃ below 3 × 10^–4. Forx ₃ around 10^–3,T ₁ andT ₂ are controlled by the formation and breakup of³He₂ molecules.     

Neural responses to facial and vocal expressions of fear and disgust

Neuropsychological studies report more impaired responses to facial expressions of fear than disgust in people with amygdala lesions, and vice versa in people with Huntington's disease. Experiments using functional magnetic resonance imaging (fMRI) have confirmed the role of the amygdala in the response to fearful faces and have implicated the anterior insula in the response to facial expressions of disgust. We used fMRI to extend these studies to the perception of fear and disgust from both facial and vocal expressions. Consistent with neuropsychological findings, both types of fearful stimuli activated the amygdala. Facial expressions of disgust activated the anterior insula and the caudate-putamen; vocal expressions of disgust did not significantly activate either of these regions. All four types of stimuli activated the superior temporal gyrus. Our findings therefore (i) support the differential localization of the neural substrates of fear and disgust; (ii) confirm the involvement of the amygdala in the emotion of fear, whether evoked by facial or vocal expressions; (iii) confirm the involvement of the anterior insula and the striatum in reactions to facial expressions of disgust; and (iv) suggest a possible general role for the perception of emotional expressions for the superior temporal gyrus.