Competing Modes for Crack Initiation from Non-metallic Inclusions and Intrinsic Microstructural Features During Fatigue in a Polycrystalline Nickel-Based Superalloy

Cyclic fatigue experiments in the high and very high cycle fatigue regimes have been performed on a René 88DT polycrystalline nickel-based superalloy. The microstructural configurations that favor early strain localization and fatigue crack initiation at high temperature from 400 °C to 650 °C have been investigated. Competing failure modes are observed in the high to the very high cycle fatigue regime. Fatigue cracks initiate from non-metallic inclusions and from intrinsic internal microstructural features. Interestingly, as stresses are reduced into the very high cycle regime, there is a transition to initiation only at crystallographic facets. At higher stress in the high cycle fatigue regime, a significant fraction of specimens initiate cracks at non-metallic inclusions. This transition is analyzed with regard to microstructural features that favor strain localization and accumulate damage early during cycling.     

Evaluation of "shotgun" proteomics for identification of biological threat agents in complex environmental matrixes: experimental simulations

There is currently a great need for rapid detection and positive identification of biological threat agents, as well as microbial species in general, directly from complex environmental samples. This need is most urgent in the area of homeland security, but also extends into medical, environmental, and agricultural sciences. Mass-spectrometry-based analysis is one of the leading technologies in the field with a diversity of different methodologies for biothreat detection. Over the past few years, "shotgun"proteomics has become one method of choice for the rapid analysis of complex protein mixtures by mass spectrometry. Recently, it was demonstrated that this methodology is capable of distinguishing a target species against a large database of background species from a single-component sample or dual-component mixtures with relatively the same concentration. Here, we examine the potential of shotgun proteomics to analyze a target species in a background of four contaminant species. We tested the capability of a common commercial mass-spectrometry-based shotgun proteomics platform for the detection of the target species (Escherichia coli) at four different concentrations and four different time points of analysis. We also tested the effect of database size on positive identification of the four microbes used in this study by testing a small (13-species) database and a large (261-species) database. The results clearly indicated that this technology could easily identify the target species at 20% in the background mixture at a 60, 120, 180, or 240 min analysis time with the small database. The results also indicated that the target species could easily be identified at 20% or 6% but could not be identified at 0.6% or 0.06% in either a 240 min analysis or a 30 h analysis with the small database. The effects of the large database were severe on the target species where detection above the background at any concentration used in this study was impossible, though the three other microbes used in this study were clearly identified above the background when analyzed with the large database. This study points to the potential application of this technology for biological threat agent detection but highlights many areas of needed research before the technology will be useful in real world samples.     

Perception of the pleasantness and competence of a partner.

An experiment was conducted to test hypotheses derived from Festinger's theory of cognitive dissonance concerning changes in the perception of a partner's pleasantness and competence following the discovery of unpleasant characteristics of the partner. College women who received information indicating their partner for a problem-solving task was very unpleasant rated her as less unpleasant than women who received identical information about someone who was not their partner. Those who received information indicating their partner was very unpleasant rated her as more competent than women who received information indicating their partner had fewer unpleasant characteristics. Whether they had chosen to work with the partner or were assigned had no significant effects on their ratings of her pleasantness or competence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of commitment and certainty upon interest in supporting information.

A field experiment was conducted to test hypotheses derived from a theory concerning interest in information about the relative merits of alternative actions. After college men stated a position on an issue, they indicated their interest in reading articles favoring each side of the issue and also rated how certain they were their position was best. Some were told their position would be publicized, others that it would be kept completely private. In accordance with the hypotheses, when they were publicly committed to a position, the less certain they were it was the best position the more they preferred information supporting the position; when they were not committed, the more certain they were the more they preferred supporting information (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of severity of initiation on liking for a group.

"An experiment was conducted to test the hypothesis that persons who undergo an unpleasant initiation to become members of a group increase their liking for the group; that is, they find the group more attractive than do persons who become members without going through a severe initiation. This hypothesis was derived from Festinger's theory of cognitive dissonance." 3 conditions were employed: reading of "embarrassing material" before a group, mildly embarrassing material to be read, no reading. "The results clearly verified the hypothesis." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preprints Anonymous.

This note proposes a new special interest group of APA members, devoted to preserving and improving APA journals as the medium for scholarly research. We shall consider ways of raising standards for publication, of increasing the journals' hospitality to original ideas and to criticism of accepted ideas, and of shortening the time lag. A tentative name for the group is Preprints Anonymous. Wide circulation of unedited preprints and research reports having become a major means for eroding standards, members are asked to pledge that they will not read any unedited, unsolicited preprint. Exceptions can be made for the work of their own collaborators and colleagues and for genuine requests for criticism prior to publication. Information for those interested in joining the group is included. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Upflow vertical tube evaporation with interface enhancement; pressure drop reduction and heat transfer enhancement by the addition of a surfactant

The heat transfer performance of a series of full-sized, commercial distillation tubes of the double-fluted type was evaluated in an upflow vertical tube evaporator, under process conditions that are realistic for large-plant multiple effect operation. This tube series comprised two of each aluminum-brass tubes, 1O-ft. long and 3-, 2-, 1.5- and 1-in. diameter, tested in parallel pairs. Fresh water and sea water were used as feeds recirculated to the evaporator, with and without the addition of a surfactant for interface enhancement: heat transfer performance was approximately doubled with the larger diameter tubes but the smaller tubes did not respond well. It was concluded that differences in tube diameter can account for the apparent contradictions in the literature, on the basis of our tube pressure drop data. Some conclusions pertinent to the design of multiple-effect vertical tube evaporators are also drawn.     

The diverse patterns of hepatitis A epidemiology in the United States-implications for vaccination strategies

Hepatitis A is the most frequently reported vaccine-preventable disease in the United States. Hepatitis A incidence and risk factors during 1983-1995 were examined among cases reported to the study's Sentinel Counties: Denver County, Colorado; Pierce County, Washington; Jefferson County, Alabama; and Pinellas County, Florida. Of 4897 serologically confirmed cases, 611 patients (13%) were hospitalized and 9 (0.2%) died. The average incidence was 14.7/100, 000 (range, 0.6-100.7/100,000, depending on county and year). The frequency of reported sources of infection varied by county, but the largest single group overall (52%) did not report a source. During 3-year communitywide outbreaks in Denver (1991-1993) and Pierce (1987-1989) Counties, rates increased 4- and 13-fold, respectively, and increased in all age, racial/ethnic, and risk groups. During communitywide outbreaks, hepatitis A is not limited to specific risk groups; sustained nationwide reductions in incidence are more likely to result from routine childhood vaccination than from targeted vaccination of high-risk groups.     

Adsorption of botulinum toxin to activated charcoal with a mouse bioassay

STUDY OBJECTIVE: We evaluated the effectiveness of activated charcoal (AC) in adsorbing Clostridium botulinum type A toxin using a mouse bioassay. DESIGN: Prospective, blinded, randomized, controlled animal study. SETTING: Animal care facility. PARTICIPANTS: One hundred forty Swiss/Webster ND-4 strain mice. INTERVENTION: Food contaminated with type A botulinum toxin was homogenized in a phosphate/gel buffer (pH 6.2). The concentrate was diluted by factors of 1:10, 1:50, and 1:100. AC was added to aliquots of the dilutions to a 20% final concentration. The samples were centrifuged, supernatant was removed, and separate groups of mice were injected intraperitoneally with .5 mL of each dilution (those treated with AC and controls untreated with AC). The animals were then observed over 5 days for signs of botulism. RESULTS: None of the 60 animals injected intraperitoneally with dilutions treated with AC was observed to have any signs of botulism. In contrast, deaths were observed in 10 of 20, 9 of 20 and 4 of 20 mice injected with untreated dilutions of 1:100, 1:50, and 1:10, respectively (P < .004). CONCLUSION: In this model, treatment of botulinum toxin with AC before administration resulted in greatly reduced morbidity and mortality.