A mild,protective and efficient procedure for grinding coal: cryocrushing

Conventional grinding methods are harsh and produce dramatic changes in coal. When coal, initially at room temperature, is ground in the presence of air, the high localized temperatures produced are known to cause both the production of gases and surface oxidation. These perturbations make meaningful measurements on the product very difficult. A technique that minimizes these effects is the pulverization of coal in liquid nitrogen. Compared with conventional methods, the process is rapid and appears to be less destructive chemically. Electron Spectroscopy for Chemical Analysis (ESCA) measurements support this conclusion. Surface oxidation is significantly reduced by this mild treatment. The method produces more particles below 38 μm than does conventional grinding and these fine particles are less prone to agglomeration.     

Instrumental conditioning of human heart rate during free and controlled respiration

The effect of respiratory constraint on heart rate control was assessed in a biofeedback situation with feedback consisting of changes in both illumination level and intensity of pre-recorded baby's cry. Subjects were reinforced for alternately increasing and decreasing heart rate on each of seven days during which respiration was unconstrained (Phase 1). This phase was followed by eight days when respiration was constrained during training sessions with a control respirator (Phase 2). Seven additional days of training followed in the unconstrained situation (Phase 3). Results indicate that the control of heart rate in biofeedback situations is very closely related to respiratory and other somatic activity. The implication of these findings for the field of visceral control is discussed.     

Age-related disruption of trace but not delay classical conditioning of the rabbit's nictitating membrane response.

16 6-mo-old and 15 36–60 mo old New Zealand albino rabbits underwent classical conditioning of the nictitating membrane response in either a delay conditioning (Exp I) or a trace conditioning (Exp II) paradigm. There was no difference between old and young Ss in the acquisition of the CR in the delay paradigm, nor were there any age-related differences in generalization to the tone CS or in sensitivity to the tone CS or eyeshock UCS. However, in the trace conditioning paradigm, old Ss acquired the CR significantly more slowly than young Ss. Because the same stimulus parameters and the same response were used in both experiments, it is unlikely that age-related differences in trace conditioning were due to stimulus sensitivity, motivation, or fatigue. Results are discussed in terms of how brain changes that accompany aging could differentially affect these 2 types of classical conditioning. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological factors in the prediction of Lyme disease course

We developed methodology for prospective randomized effectiveness studies using a demonstration project at a multispecialty practice, health maintenance organization, and hospital in academic medical center. An operational unit called the effectiveness registry was developed to design and support comparisons of potential practice improvements with standard care. The studies differ from observational effectiveness studies in that they provide long-term follow-up of randomized comparison groups. Physician involvement in data collection is limited. No tests or observations are made other than those required for clinical care. Follow-up and data collection are modeled after tumor registry procedures. Patients who refuse randomization enter the study in whichever treatment arm they choose. The protocol for each study is approved by the institutional review board (IRB) before recruitment begins, and all patients, randomized and nonrandomized, sign an informed consent document. Between its beginning on October 7, 1993 and April 7, 1997, the IRB approved 14 trials. Four were terminated after entering at most a few patients. Recruitment is complete in four trials and continues in six. Randomization was accepted by 74% (596/804) of the patients. Over 800 patients in 10 studies are being followed at least annually. Major peer-reviewed journals have accepted reports of initial findings for two studies. Prospective randomized effectiveness studies are feasible in the multipractice setting and have potential to provide useful and reliable assessment of treatment outcomes. Collaborative arrangements between several institutions are needed to provide larger sample sizes.     

Activation of NMDA and non-NMDA receptors in the caudal ventrolateral medulla dilates the airways

Calpain is a ubiquitous calcium-dependent cysteine protease, whose cytoskeletal protein substrates suggest that it may be important in neuronal differentiation. Lead (Pb2+) is known to substitute for Ca2+ in a variety of intracellular processes, and interferes with the development of hippocampal neurons in vitro. We found that free Pb2+ at 1 nM does not activate calpain in the absence of Ca2+. Pb2+ inhibited the activity of calpain; the degree of calpain inhibition was dependent on an interaction between concentrations of both Ca2+ and Pb2+. In the presence of 1 microM free Ca2+, 10 pM free Pb2+ reduced calpain activity, but in the presence of 100 microM free Ca2+, 1 nM free Pb2+ failed to inhibit calpain. This provides evidence that Pb2+ competes for the Ca2+ binding sites on calpain. In the presence of 40 microM free Ca2+, 1 nM free Pb2+ significantly reduces Vmax without altering Km, suggesting that Pb2+ acts as a noncompetitive inhibitor of calpain. Inhibition of calpain is one mechanism by which Pb2+ may interfere with neuronal development.     

Evaluation of a rapid immunochromatographic test for diagnosis of dengue virus infection

A rapid (<7-min) immunochromatographic test for immunoglobulin M (IgM) and IgG antibodies to dengue viruses was evaluated by using hospital admission and discharge sera from 124 patients. The reference laboratory diagnosis was based on the results of virus isolation, hemagglutination-inhibition assay (HAI), and enzyme immunoassay (EIA). By the standard assays, patients experienced primary dengue virus infection (n = 30), secondary dengue virus infection (n = 48), Japanese encephalitis (JE) virus infection (n = 20), or no flavivirus infection (n = 26). The rapid test demonstrated 100% sensitivity in the diagnosis of dengue virus infection and was able to distinguish between primary and secondary dengue virus infections through the separate determinations of IgM and IgG. For all patients with primary dengue virus infection a positive test for IgM to dengue virus and a negative test for IgG to dengue virus were obtained, whereas for 46 of 48 patients (96%) with secondary dengue virus infection, a positive test for IgG to dengue virus with or without a positive test for IgM to dengue virus was obtained. The remaining two patients with secondary dengue virus infection had positive IgM test results and negative IgG test results. Furthermore, the rapid test was positive for patients confirmed to be infected with different dengue virus serotypes (12 infected with dengue virus serotype 1, 4 infected with dengue virus serotype 2, 3 infected with dengue virus serotype 3, and 2 infected with dengue virus serotype 4). The specificity of the test for nonflavivirus infections was 88% (3 of 26 positive), while for JE virus infections the specificity of the test was only 50% (10 of 20). However, most patients with secondary dengue virus infection were positive for both IgM and IgG antibodies to dengue virus, while no patients with JE virus infection had this profile, so cross-reactivity was only a concern for a small proportion of patients with secondary dengue infections. The rapid test demonstrated a good correlation with the reference EIA and HAI and should be useful for the rapid diagnosis of dengue virus infections.     

PTSD among Israeli former prisoners of war and soldiers with combat stress reaction: a longitudinal study

OBJECTIVE: The aim of this study was to assess the long-term impact of war captivity and combat stress reaction on rates of posttraumatic stress disorder (PTSD) in Israeli veterans of the 1973 Yom Kippur war. METHOD: One hundred sixty-four former prisoners of war (POWs), 112 veterans who had had combat stress reaction, and 184 combat veteran comparison subjects filled out the PTSD Inventory, a self-report scale based on the DSM-III-R criteria for PTSD. The inventory diagnoses past and present PTSD, assesses its intensity, and provides a symptom profile. RESULTS: Thirty-seven percent of the veterans who had had combat stress reaction, 23% of the former POWs, and 14% of the comparison subjects had had diagnosable PTSD at some time in the past. The current rates were 13%, 13%, and 3%, respectively. The results showed different recovery rates over time: almost two-thirds of the veterans with combat stress reaction who had had PTSD in the past recovered, while less than one-half of the POW group showed this improvement. CONCLUSIONS: These findings indicate that small but significant proportions of the POWs and veterans with combat stress reaction were still suffering from PTSD almost two decades after the war. The different recovery rates in the two groups may reflect the differences in duration and severity of stressors, the impact of immediate intervention on long-term adjustment, or both.     

Individual characteristics and children's performance in open and traditional classroom settings.

Assessed the performance of 56 boys and 36 girls with different motivational and cognitive characteristics in 3 "open" and 3 "traditional" 4th-grade classrooms. Cluster analysis of factor scores representing child orientations, motives, and prior achievement produced 6 "types." Three-way analyses of variance investigated the effects of child type, classroom type (open vs traditional), sex of child, and various interactions on several outcome measures, including academic achievement, creativity, inquiry skill, social-educational attitudes, and teacher ratings of children's classroom behavior. Main effects appeared for each of the 3 independent variables, along with several Child * Class interactions. An approach using child types or clusters rather than abstracted dimensions may facilitate further Attribute * Treatment interaction research and applications. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)