Towards the definition of pathogenic microbe

Identification and typing of spoilage and pathogenic microorganisms have become major objectives over the past decade in microbiology. In food, strain typing is necessary to ensure food safety and for linking cases of foodborne infections to suspected items. Recent advances in molecular biology have resulted in the development of numerous DNA-based methods for discrimination among bacterial strains. Here, we present the use of Simple Sequence Repeats (SSR, or Microsatellites) for bacterial typing. SSRs are a class of short DNA sequence motifs that are tandemly repeated at a specific locus. Computer-based screen of the complete genomic DNA sequences of various prokaryotes showed the existence of tens of thousands well distributed SSR tracts. Mono Nucleotides Repeats (MNRs) are the majority of SSR tracts in bacteria, therefore selected MNR loci were analyzed for variation among strains belonging to three bacterial species: Escherichia coli, Listeria monocytogenes and Vibrio cholerae. High levels of polymorphism in the number of repeats was observed. The finding that most of the MNR tracts are variable in bacterial genomes, but stable at the strain level, allows the use of MNRs for bacterial strains identification. The variation in MNR tracts enables the separation between virulent and non-virulent strain groups and further discriminates among bacterial isolates, in the three tested bacterial species. The uncovered MNR polymorphism is important as a genome-wide source of variation, both in practical applications (e.g. rapid strain identification) and in evolutionary studies. This multi-locus MNR strategy could be applied for high throughput bacterial typing by assigning an "identity number" for each strain based on MNR variations. The developed typing technology should include the fingerprint database for large bacterial strain collections and a high throughput scanner. This accurate and rapid tool can have a major role in decreasing the incidences of food-related outbreaks and will contribute to limit epidemics.     

Impact of treated wastewater irrigation on antibiotic resistance in agricultural soils

Antibiotic resistance (AR) is a global phenomenon with severe epidemiological ramifications. Anthropogenically impacted natural aquatic and terrestrial environments can serve as reservoirs of antibiotic resistance genes (ARG), which can be horizontally transferred to human-associated bacteria through water and food webs, and thus contribute to AR proliferation. Treated-wastewater (TWW) irrigation is becoming increasingly prevalent in arid regions of the world, due to growing demand and decline in freshwater supplies. The release of residual antibiotic compounds, AR bacteria, and ARGs from wastewater effluent may result in proliferation of AR in irrigated soil microcosms. The aim of this study was to assess the impact of TWW-irrigation on soil AR bacterial and ARG reservoirs. Tetracycline, erythromycin, sulfonamide, and ciprofloxacin resistance in soil was assessed using standard culture-based isolation methods and culture-independent molecular analysis using quantitative real-time PCR (qPCR). High levels of bacterial antibiotic resistance were detected in both freshwater- and TWW-irrigated soils. Nonetheless, in most of the soils analyzed, AR bacteria and ARG levels in TWW-irrigated soils were on the whole identical (or sometimes even lower) than in the freshwater-irrigated soils, indicating that the high number of resistant bacteria that enter the soils from the TWW are not able to compete or survive in the soil environment and that they do not significantly contribute ARG to soil bacteria. This strongly suggests that the impact of the TWW-associated bacteria on the soil microbiome is on the whole negligible, and that the high levels of AR bacteria and ARGs in both the freshwater- and the TWW-irrigated soils are indicative of native AR associated with the natural soil microbiome.     

Effect of soy addition on microwavable pocket-type flat doughs

Microwavable frozen baked goods are widely used by the food industry. However, the altered heat and mass transfer patterns associated with microwave radiation result in tough and rubbery baked products due to reduced plasticization of the polymers. Ingredients with high water-holding capacity and high content of polar lipids have been shown to enhance gluten plasticization and to improve water retention. Therefore, this study explored the physicochemical changes imparted by microwave baking of pocket-type flat doughs with and without soy added at 10%, 20%, and 26% and compared these to their conventionally baked counterparts. Microwave baking resulted in a soft, rubbery, and tough wheat product with increased "freezable" water. Soy was added to the formulation as a means to improve polymer plasticization. Conventional baking of soy doughs resulted in rubbery and tough products due to changes in water state and mobility (freezable water approximately 15 compared with 7.09 of the control). However, soy reduced the cohesiveness of the microwave baked products reaching the lowest value at 20% soy addition (cohesiveness 0.33 ± 1, comparable to that of the conventionally baked control). These data suggest that reduction of water mobility induced by soy proteins and polar lipids (confirmed by thermogravimetric analysis [TGA] and 1H nuclear magnetic resonance [1H NMR]) possibly plasticized the starch-gluten network of microwave baked soy doughs. Thus, soy was shown to improve the texture of microwave baked pocket-type flat doughs although further formula optimization is warranted. PRACTICAL APPLICATION: Microwavable pocket-type flat doughs are used frequently by the food industry to enrobe meat, vegetable, and sweet items for convenient meal delivery. Microwave heating of such doughs induces the development of crustless products compared to conventionally baked products, resulting in a tough and rubbery texture. Partial substitution of wheat flour with soy, in the form of soy flour and soy milk powder, prevented the deleterious textural changes associated with microwave heating. These results suggest that soy is a functional ingredient for the textural improvement of microwavable pocket-type flat doughs.     

Marital discord and well-being in older adults: Is the association confounded by personality?

The associations between marital discord and multiple measures of well-being (depression, anxiety, life satisfaction, and self-esteem) were evaluated in a population-based sample of 416 couples in which the husband was 65 years or older. Results indicated that greater marital discord was associated with greater depression and lower life satisfaction and self-esteem. Furthermore, the associations between marital discord and well-being remained significant when statistically controlling for the rival explanation of the Big Five personality traits. Finally, there was little evidence for gender differences in the magnitude of the associations between marital discord and well-being. Findings suggest that marital discord is an important correlate of multiple measures of well-being in older individuals and that this association is not confounded by the Big Five personality traits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Epidemiological aspects of inflammatory bowel disease in a north Italian population: a 4-year prospective study

OBJECTIVE: To determine the incidence and clinical characteristics at presentation of inflammatory bowel disease (IBD) in a defined area of north Italy. DESIGN: A 4-year prospective population-based epidemiological study. SETTING: An area in Lombardia defined by the National Health Service scheme with about 294,000 inhabitants, two referral hospitals and 259 general practitioners (GPs). PATIENTS: Subjects presenting to a GP with symptoms compatible with IBD underwent a diagnostic work-up at one of the referral hospitals. Those with ulcerative colitis (UC), Crohn's disease (CD) or indeterminate colitis diagnosed according to a defined protocol were included, as were residents of the area with IBD diagnosed elsewhere. Rigid case ascertainment methods were used. Patients were followed for one year; 125 patients were identified. RESULTS: The patient ascertainment rate was constant over the 4 years; UC was diagnosed in 82 patients, CD in 40, and indeterminate colitis in three. The mean annual incidence of IBD for the whole period was 10.6/10(5) inhabitants (95% confidence limits, 7.2-15.1), 7.0/10(5) for UC (4.3-10.7) and 3.4/10(5) (1.6-6.3) for CD. The mean interval between onset of symptoms and diagnosis was under 6 months. The clinical characteristics of our patients were similar to those of north European and American series. CONCLUSION: The incidence of IBD was higher than previously observed in Italy but was still lower than in some north European countries and in the USA. Our data could be used as a basis for future longitudinal studies and in international comparative investigations.     

A three-dimensional statistical framework for performance measurement of robotic systems

A three-dimensional statistical evaluation framework for performance measurement of robotic systems has been developed. A specific experimental setup has been designed, implemented, and evaluated for different robot characteristics (velocities and target location) and for a specific task. A statistical analysis method to evaluate performance is demonstrated. Results indicate the significance of this methodology since the capabilities and performance of a particular robot depend on actual operating conditions.     

Using a Human Figure Drawing to Elicit Information From Alleged Victims of Child Sexual Abuse.

Ninety 4- to 13-year-old alleged victims of sexual abuse were interviewed by police officers using the National Institute of Child Health and Human Development (NICHD) investigative interview protocol, following which they were shown a human figure drawing and asked a series of questions. The drawing and associated questions elicited an average of 86 new forensically relevant details. They were especially productive with 4- to 7-year-olds, who provided an average of 95 additional details (27% of their total) after the drawing was introduced despite having previously "exhausted" their memories. Information elicited using the drawing may be less accurate, however, because recognition memory prompts predominated, so such drawings should only be introduced late in investigative interviews. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parametric MRI of Water Diffusion in Breast Cancer

Diffusion MRI studies revealed specific morphological and physiological properties of MCF7 tumors implanted in the mammary gland of immunodeficient mice. These tumors mimic the histological and pathophysiological properties of human breast cancer in patients. The experiments were conducted by (1) applying varying diffusion gradient strengths, G_d, from 0 to 20 G/cm and a short diffusion time (t_d = 16 ms) in order to minimize the effect of restriction and exchange of water between the intra- and extracellular compartments, and (2) applying a strong constant gradient and diffusion times up to 96 ms, revealing water restriction and exchange. The normalized signal intensity was plotted against the diffusion weighting factor b , taking into account interaction with the imaging gradients. The curves were analyzed by applying a bi-exponential decay function assuming two exchanging water compartments, with fast and slow diffusion coefficients. The amplitudes and decay constants of the two exponents, a fast and a slow one, were related to the fraction and apparent diffusion coefficients of the extra- and intracellular water, respectively, considering contributions of restriction and exchange. During tumor progression the distribution of the diffusion parameters for the same experimental protocol varied and became less homogeneous. This was predominantly due to variations in the cellularity and increased necrosis. Upon treatment of the tumors with a new anti-estrogenic drug, tamoxifen methiodide, the changes in the diffusion parameters indicated increased cell swelling. Hence, this cytostatic response to treatment was detected before actual cell death was apparent. The potential capacity of diffusion MRI is of high clinical relevance and may help improve the noninvasive diagnosis and followup of treatment of this devastating disease.     

Thermal decomposition of monomethylamine nitrate

Experimental thermal analysis and mass spectrometric results indicate that, when heated, monomethylamine nitrate dissociates to form monomethylamine anMonomethylamine, one of the dissociation products, is a flammable gas. In dry air, at room temperature, its lower limit of flammability is 4.9%. Its auPreventing acid build-up and rust formation is important for the safe handling and transport of monomethylamine nitrate.