Combining spore germination and heat inactivation to decontaminate materials contaminated with Bacillus anthracis spores.

AIMS: To add a spore germination step in order to reduce decontamination temperature and time requirements compared to the current hot, humid air decontamination parameters, which are 75-80°C, ≥72 h, 70-90% RH, down to ≤60°C and ≤24 h total decontamination time. METHODS AND RESULTS: Bacillus anthracis spore germination with l-alanine+inosine+calcium dipicolinate (CaDPA) was quantified at 0-40°C, several time points and spore concentrations of 5-9 log10 per ml. Germination efficiency at 0-40°C was >99% at <8 log10 spores per ml. The temperature optimum was 20°C. Germination efficiency was significantly higher but slower at 0°C compared to ≥30°C at ≥8 log10 spores per ml. A single germinant application followed by 60°C, 1-h treatment consistently inactivated >2 log10 (>99%) of spores. However, a repeat application of germinant was needed to achieve the objective of ≥6 log10 spore inactivation out of a 7 log10 challenge (≥99·9999%) for ≤24 h total decontamination time for nylon and aircraft performance coating. CONCLUSIONS: l-alanine+inosine+CaDPA stimulated germination across wide temperature and spore concentration ranges. SIGNIFICANCE AND IMPACT OF THE STUDY: Germination expands the scope of spore decontamination to include materials from any industry sector that can be sprayed with an aqueous germinant solution.

Amodal completion of acoustic signals by a nonhuman primate.

Evidence of amodal completion exists for both visual and auditory stimuli in humans. The importance of this mechanism in forming stable representations of sensory information suggests that it may be common among multiple modalities and species. Here we show that a species of nonhuman primate amodally completes biologically meaningful acoustic stimuli, which provides evidence that the neural mechanism mediating this aspect of auditory perception is shared among primates, and perhaps other taxonomic groups as well.

Genomic amplification of MET with boundaries within fragile site FRA7G and upregulation of MET pathways in esophageal adenocarcinoma.

Esophageal adenocarcinoma (EA) is characterized by a poor prognosis making the identification of clinically targetable proteins essential for improving patient outcome. We report the involvement of multiple alterations of the MET pathway in EA development and progression. Microarray analysis of Barrett's metaplasia, dysplasia, and EA revealed overexpression of the MET oncogene in EAs but only those with MET gene amplification. STS-amplification mapping revealed that the boundary of the MET amplicon in these EAs is defined by fragile site FRA7G. We also identified an amplicon at 11p13 that resulted in amplification and overexpression of CD44, a gene involved in MET autophosphorylation upon HGF stimulation. Tissue microarrays with phospho-MET-specific antibodies demonstrated a uniformly high abundance of MET activation in primary EA and cells metastatic to lymph nodes but to a lesser extent in a subset of metaplastic and dysplastic Barrett's samples. Increased expression of multiple genes in the MET pathway associated with invasive growth, for example, many MMPs and osteopontin, also was found in EAs. Treatment of EA-derived cell lines with geldanamycin, an inhibitor for tyrosine kinases including MET receptor kinase, reduced cell migration and induced EA cell apoptosis. The data indicate that upregulation of the MET pathway may contribute to the poor outcome of EA patients and that therapeutic agents targeting this pathway may help improve patient survival.

Student doctors and women in labor: attitudes and expectations.

OBJECTIVE: To compare the attitudes and expectations that obstetric patients and medical students bring to the student-patient relationship in intrapartum care. METHODS: Written questionnaires were distributed to obstetric patients who had students assist in their labor and delivery care and to medical students who had completed their clinical clerkship year. Responses of 222 patients and 67 students were analyzed for differences in expectations of student participation and assessment of skills. RESULTS: Responses of medical students and patients were significantly different in all attitudes and expectations studied. One hundred thirty-six (61%) patients compared with 27 (40%) students identified the patients' wish to contribute to the education of students as the most important reason for agreeing to student participation. All patients felt that student participation should be requested rather than assigned, with 194 (87%) patients but only 30 (45%) students wishing to have the student absent from the room at the time of the request. Mean ratings of different student skills tended to be higher from patients (1.3-1.8 on a seven-point Likert scale) than from the students themselves (range 1.6-2.4). Although students' expectations of participation in patient care were high, patients indicated expectations of fairly low levels of student involvement in communication, examination, labor support, and procedures. CONCLUSION: Students have high expectations for their active involvement in intrapartum care and tend to under-estimate the sense of altruism that motivates patients to allow student participation. Patients have low expectations of levels of student participation in their care, but are overall quite satisfied with the skills of the students. These differences highlight the need for the development of educational objectives that clarify student roles in clinical clerkships and the process of informed consent for student participation.

Obstetric patients who select and those who refuse medical students' participation in their care.

PURPOSE: To assess attitudes and expectations of obstetric patients toward the involvement of medical students in their care. METHOD: At the Medical Center Hospital of Vermont in 1991, questionnaire responses were collected from 222 obstetric patients who had been assisted by clerkship students from the University of Vermont College of Medicine and 78 patients who had refused the participation of students. The responses were analyzed for differences in demographic backgrounds, prior hospital experiences, and general expectations of student involvement, using chi-square, two-tailed t-tests and analysis of variance. RESULTS: Both groups of respondents consisted primarily of young, well-educated, married women, who appear to have made their decisions about student participation by balancing their personal needs and their sense of altruism. For example, 61% of those who had refused the participation of students ranked the desire for privacy as their primary reason, whereas 73% of those who had accepted student participation ranked as their primary reason the desire to contribute to a student's education. Although both groups of patients expected the students to perform few clinical procedures, the patients who had refused student participation expected the students to be more involved in patient care than did the patients who had allowed participation. Of the 25% of the patients who had had students involved in prior pregnancy care, those who had currently refused student participation had less positive views of prior student care. CONCLUSION: Patients' needs for privacy, past experiences with student care, and expectations of student performance should be considered to ensure the respectful incorporation of student involvement in obstetric care.

Mutagenicity induced by lyophilization or storage of urine from isoniazid-treated rats.

Urine collected during 24 h after treatment of rats with 90--550 mg/kg isonicotinic acid hydrazide (isoniazid, INH) was after lyophilization, mutagenic for Salmonella typhimurium TA1535. Urine collected directly from bladders of INH-treated rats was not mutagenic, and solutions of INH in water or urine became mutagenic only after lyophilization. In the absence of lyophilization, sterile urine from INH-treated rats became mutagenic after 8--14 days' storage at room temperature.

Mutagenic effect of nialamide on Salmonella typhimurium.

The mutagenicity of an antidepressant drug, nialamide, was studied with Salmonella typhimurium TA1535-8. Nialamied was mutagenic for strain TA1535 in the absence of rat liver extracts.

Pore-scale modeling of saturated permeabilities in random sphere packings.

We use two pore-scale approaches, lattice-Boltzmann (LB) and pore-network modeling, to simulate single-phase flow in simulated sphere packings that vary in porosity and sphere-size distribution. For both modeling approaches, we determine the size of the representative elementary volume with respect to the permeability. Permeabilities obtained by LB modeling agree well with Rumpf and Gupte's experiments in sphere packings for small Reynolds numbers. The LB simulations agree well with the empirical Ergun equation for intermediate but not for small Reynolds numbers. We suggest a modified form of Ergun's equation to describe both low and intermediate Reynolds number flows. The pore-network simulations agree well with predictions from the effective-medium approximation but underestimate the permeability due to the simplified representation of the porous media. Based on LB simulations in packings with log-normal sphere-size distributions, we suggest a permeability relation with respect to the porosity, as well as the mean and standard deviation of the sphere diameter.

Psychosocial characteristics of preschool siblings of handicapped and nonhandicapped children.

This project examined psychosocial characteristics of 24 preschool-aged siblings of handicapped children in relation to a control group of 22 siblings of nonhandicapped children. Subjects were matched on family size and income, sibling age, birth order, sex, age spacing, and marital status of their parents. Results indicated no statistically significant differences between groups of children on measures of perceived self-competence and acceptance, understanding of developmental disabilities, empathy, and child care responsibility. Significant group differences were found where brothers of handicapped children were rated by their mothers as being more depressed and aggressive than brothers of nonhandicapped control children. Sisters of handicapped children were rated by mothers as being more aggressive than sisters of nonhandicapped children. Sisters of handicapped children and brothers of nonhandicapped children had significantly fewer privileges and more restrictions on their home activities than other groups. Results are discussed in relation to previous research on older siblings of handicapped children and the general literature on family stress and childhood disability and disease. The importance of examining sibling functioning via multiple measures of child behavior is stressed.

What mentally retarded and nonretarded children expect of one another.

Twenty mentally retarded students and nonretarded students matched for chronological age (n = 20) or mental age (n = 16) made judgments about children described as having or not having learning problems. Results showed that students had both positive and negative stereotyped expectations about these children and that there were few differences between the expectations of retarded and nonretarded students. Students' responses to stereotype questions 11 to 18 months later revealed few changes in their stereotypes and no significant differences between stability of retarded and nonretarded students' stereotypes. Results suggest that understanding social relations between retarded and nonretarded children requires consideration of the expectations of both groups.

Preschool siblings of handicapped children: interactions with mothers, brothers, and sisters.

The purpose of this investigation was to examine similarities and differences between young (aged 3 years to 6 years 9 months) siblings of handicapped and nonhandicapped children in their behavioral interactions with their mothers, brothers, and sisters. Behavior of mothers toward the different groups of children also was examined. Results revealed few differences between sibling groups in the quantity or quality of their interactions with family members. In comparison to the matched control children, siblings of handicapped children engaged in more parallel play and social play, and were more nurturing but no more likely to interact aggressively or to be commanding or directive with their brothers or sisters. Mothers in the experimental group were found to target significantly more nurturant behaviors toward their children compared to control mothers and were significantly more likely to deliver commands, directives, and reprimands to siblings of handicapped children than to any other child. Results are discussed in terms of their correspondence to previous observational and interview research.

Decreased myosin phosphatase target subunit 1(MYPT1) phosphorylation via attenuated rho kinase and zipper-interacting kinase activities in edematous intestinal smooth muscle.

BACKGROUND: Intestinal edema development after trauma resuscitation inhibits intestinal motility which results in ileus, preventing enteral feeding and compromising patient outcome. We have shown previously that decreased intestinal motility is associated with decreased smooth muscle myosin light chain (MLC) phosphorylation. The purpose of the present study was to investigate the mechanism of edema-induced decreases in MLC in a rodent model of intestinal edema. METHODS: Intestinal edema was induced by a combination of resuscitation fluid administration and mesenteric venous hypertension. Sham operated animals served as controls. Contractile activity and alterations in the regulation of MLC including the regulation of MLC kinase (MLCK) and MLC phosphatase (MLCP) were measured. KEY RESULTS: Contraction amplitude and basal tone were significantly decreased in edematous intestinal smooth muscle compared with non-edematous tissue. Calcium sensitivity was also decreased in edematous tissue compared with non-edematous intestinal smooth muscle. Although inhibition of MLCK decreased contractile activity significantly less in edematous tissue compared with non-edematous tissue, MLCK activity in tissue lysates was not significantly different. Phosphorylation of MYPT was significantly lower in edematous tissue compared with non-edematous tissue. In addition, activities of both rho kinase and zipper-interacting kinase were significantly lower in edematous tissue. CONCLUSIONS & INFERENCES: We conclude from these data that interstitial intestinal edema inhibits MLC phosphorylation predominantly by decreasing inhibitory phosphorylation of the MLC targeting subunit (MYPT1) of MLC phosphatase via decreased ROCK and ZIPK activities, resulting in more MLC phosphatase activity.

Cosolvent flushing for the remediation of PAHs from former manufactured gas plants.

Cosolvent flushing is a technique that has been proposed for the removal of hydrophobic organic contaminants in the subsurface. Cosolvents have been shown to dramatically increase the solubility of such compounds compared to the aqueous solubility; however, limited data are available on the effectiveness of cosolvents for field-contaminated media. In this work, we examine cosolvent flushing for the removal of polycyclic aromatic hydrocarbons (PAHs) in soil from a former manufactured gas plant (FMGP). Batch studies confirmed that the relationship between the soil-cosolvent partitioning coefficient (K(i)) and the volume fraction of cosolvent (f(c)) followed a standard log-linear equation. Using methanol at an fc of 0.95, column studies were conducted at varying length scales, ranging from 11.9 to 110 cm. Removal of PAH compounds was determined as a function of pore volumes (PVs) of cosolvent flushed. Despite using a high f(c), rate and chromatographic effects were observed in all the columns. PAH effluent concentrations were modeled using a common two-site sorption model. Model fits were improved by using MeOH breakthrough curves to determine fitted dispersion coefficients. Fitted mass-transfer rates were two to three orders of magnitude lower than predicted values based on published data using artificially contaminated sands.

Dense, viscous brine behavior in heterogeneous porous medium systems.

The behavior of dense, viscous calcium bromide brine solutions used to remediate systems contaminated with dense nonaqueous phase liquids (DNAPLs) is considered in laboratory and field porous medium systems. The density and viscosity of brine solutions are experimentally investigated and functional forms fit over a wide range of mass fractions. A density of 1.7 times, and a corresponding viscosity of 6.3 times, that of water is obtained at a calcium bromide mass fraction of 0.53. A three-dimensional laboratory cell is used to investigate the establishment, persistence, and rate of removal of a stratified dense brine layer in a controlled system. Results from a field-scale experiment performed at the Dover National Test Site are used to investigate the ability to establish and maintain a dense brine layer as a component of a DNAPL recovery strategy, and to recover the brine at sufficiently high mass fractions to support the economical reuse of the brine. The results of both laboratory and field experiments show that a dense brine layer can be established, maintained, and recovered to a significant extent. Regions of unstable density profiles are shown to develop and persist in the field-scale experiment, which we attribute to regions of low hydraulic conductivity. The saturated-unsaturated, variable-density groundwater flow simulation code SUTRA is modified to describe the system of interest, and used to compare simulations to experimental observations and to investigate certain unobserved aspects of these complex systems. The model results show that the standard model formulation is not appropriate for capturing the behavior of sharp density gradients observed during the dense brine experiments.

Dense non-aqueous phase liquids at former manufactured gas plants: challenges to modeling and remediation.

The remediation of dense non-aqueous phase liquids (DNAPLs) in porous media continues to be one of the most challenging problems facing environmental scientists and engineers. Of all the environmentally relevant DNAPLs, tars in the subsurface at former manufactured gas plants (FMGPs) pose one of the biggest challenges due to their complex chemical composition and tendency to alter wettability. To further our understanding of these complex materials, we consulted historic documentation to evaluate the impact of gas manufacturing on the composition and physicochemical nature of the resulting tars. In the recent literature, most work to date has been focused in a relatively narrow portion of the expected range of tar materials, which has yielded a bias toward samples of relatively low viscosity and density. In this work, we consider the dissolution and movement of tars in the subsurface, models used to predict these phenomena, and approaches used for remediation. We also explore the open issues and detail important gaps in our fundamental understanding of these extraordinarily complex systems that must be resolved to reach a mature level of understanding.

An Analysis of Polynomial Chaos Approximations for Modeling Single-Fluid-Phase Flow in Porous Medium Systems.

We examine a variety of polynomial-chaos-motivated approximations to a stochastic form of a steady state groundwater flow model. We consider approaches for truncating the infinite dimensional problem and producing decoupled systems. We discuss conditions under which such decoupling is possible and show that to generalize the known decoupling by numerical cubature, it would be necessary to find new multivariate cubature rules. Finally, we use the acceleration of Monte Carlo to compare the quality of polynomial models obtained for all approaches and find that in general the methods considered are more efficient than Monte Carlo for the relatively small domains considered in this work. A curse of dimensionality in the series expansion of the log-normal stochastic random field used to represent hydraulic conductivity provides a significant impediment to efficient approximations for large domains for all methods considered in this work, other than the Monte Carlo method.

Unscheduled DNA synthesis in human leucocytes after a fish (amine source) meal with or without salad (nitrite source).

Increased unscheduled DNA synthesis (UDS) was observed previously in leucocytes from human volunteers after various meals containing nitrite from cured meats and vegetables. To explore further the role of ingested nitrite, UDS response was measured in human leucocytes after a meal of bread, butter and cod fish alone (amine source) or bread, butter and cod fish plus a salad of lettuce, radish and spinach (nitrite source). A cross-over design was used so that all subjects (10 male, 10 female) were tested after both meals. Salad (nitrite source) had no effect on the level of UDS after the meal; however, UDS increased after the meal with or without salad for trial 1, but decreased for trial 2. The difference between trials could not be accounted for by sources of variation such as differences between individuals or experimental technique. The factor(s) responsible for this significant difference between trials must be associated with the non-salad components of the meal.

Effects of saccharin and urine on the decomposition of N-nitrosomethylurea.

Addition of either saccharin or rat urine to aqueous N-methyl-N-nitrosourea (MNU) caused concentration-dependent loss of the ultraviolet absorption of MNU. The shapes of the absorption spectra of the residual MNU products were different and characteristic of either saccharin (flat-sided) or urine (symmetrical) as reaction matrix. In the presence of urine from rats fed 2.5% saccharin in the diet, the flat-sided curve characteristic of MNU-saccharin products was always observed. Further, the half-life of the MNU products in urine from saccharin-treated rats was shorter than the half-life observed in control urine, suggesting that saccharin ingestion might alter both the nature and rate of MNU decomposition in vivo. A molecular hypothesis for the mechanism of the MNU/saccharin interaction is proposed.

High school students' attitudes and actions toward "slow learners".

The relationship between high school students' attitudes and their involvement in their school's peer-tutoring program for "slow learners" was examined. Predictions about how attitudes would be related to behavior were derived from theories about attitude-behavior consistency. Results showed, as predicted, that students' attitudes toward people who receive tutoring were unrelated to their peer-tutoring behavior, whereas there was a trend for their attitudes toward their own tutees to predict whether they met with their tutees. Consistent with Ajzen and Fishbein's (1973) theory, however, the best predictor of peer-tutoring behavior was students' intentions to tutor. Moreover, both intentions and behavior were correlated with students' attitudes toward this behavior. These results were interpreted as demonstrating the value of using an empirical validated theoretical approach to predicting behavior toward slow learners.

Multiple acoustic features underlie vocal signal recognition in tamarins: antiphonal calling experiments.

We examine which acoustic features are relevant for recognition of the cotton-top tamarin (Saguinus oedipus) combination long-call. This vocalization, emitted by both males and females, functions in maintaining group cohesion, territory defense and mate attraction. Using the tamarins' natural antiphonal vocal response to hearing a combination long-call as the primary measure of recognition, we presented subjects with synthetic exemplars of combination long-calls in which we manipulated across one of three acoustic dimensions: frequency, time and amplitude. Results indicated that although acoustic features in the frequency and time domains are important for combination long-call recognition, the changes in amplitude within and between syllables are not. Furthermore, while the fundamental frequency appears to be the used to encode information about the frequency contour, the temporal information is derived from the harmonics. Overall, these results suggest that tamarins use a specific suite of acoustic features for combination long-call recognition.