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971.
Research has found that populations with low socioeconomic status (SES) and minority populations have greater access to small corner markets and less access to supermarkets than high-SES and Caucasian populations. This represents a significant difference in the farm-to-fork continuum that these populations experience. This research examined whether differential retail access to foods results in different food safety risks at the retail level for consumers with different demographics. U.S. Census Bureau census tracts with high African American, Asian, Hispanic, Caucasian, low-SES, and high-SES populations were identified in Philadelphia, PA. Approximately 60 retail food establishments were sampled in each census tract category from June 2008 to June 2010. Food samples collected at stores included milk, eggs, lunchmeat, sandwiches, and ready-to-eat (RTE) fresh fruit, greens, and herbs, when available. With the exception of milk and eggs, only food that had been handled and/or prepared at the retail level was sampled. Food samples were tested for temperature, aerobic plate count, coliforms, fecal coliforms, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes. The results indicated that internal egg temperatures were higher in samples from low-SES census tracts than in eggs from Caucasian census tracts, and eggs were more often found unrefrigerated in markets in low-SES and Asian census tracts. Milk samples from markets in Hispanic and low-SES census tracts had higher aerobic plate counts than high-SES census tract samples. Sandwiches from markets in high-SES census tracts had higher coliform counts than sandwiches from markets in all other census tract categories. Markets in Asian census tracts had a higher incidence of fecal coliform contamination on sandwiches than markets in Caucasian census tracts. Fecal coliforms were present in a percentage of RTE greens from markets in all census tracts except African American, with the highest percentages of RTE greens positive for fecal coliforms in low-SES (100%), Asian (71.4%), and Caucasian (45.5%) markets. 相似文献
972.
A retrospective study was made of 200 chronic otitis media patients. Simple chronic otitis media was observed in 76 per cent of cases; the rest were associated with cholesteatoma. In about one third of the patients, the contralateral ear showed some inflammatory middle ear disease as well. The average time lapse between initial symptoms and hospitalization was about 10 years. The events leading to the tympanic perforation were difficult to ascertain, but included probably acute otitis media, possibly external otitis, trauma, and a rather large group (35-40 per cent) of insidious 'essential perforations'. The aetiology of the 'essential perforations' is so far not known, but might be non-inflammatory in nature but related to insufficient middle ear aeration and hypo-pneumatization as well as to what is termed atelectatic ears. The bacteria isolated from chronic otitis media ears (usually gram negative bacteria and staphylococcus aureus) are usually not the types of micro-organisms found in association with any primary or acute otitis media. It is proposed that the bacterial infection encountered in what is termed 'chronic otitis media' is often a secondary infection of a primary perforated tympanic membrane, the perforation originating or persisting in underventilated ears, and having arisen from various causes--some of them as yet unknown. 相似文献
973.
Compulsory sterilization, where jail sentences will be imposed on couples if both partners remain unsterilized after the birth of their 3rd child, will be introduced in India, and it is thought that such a program will fail. Indian officials justify compulsory sterilization on the grounds that the country's survival is at stake. This argument, however, is not self-evident. Coercion entails potential moral and political consequences. Preliminary evidence on the effects of a combination of income redistribution, lowered infant mortality, improved literacy, and readily available family planning services and information show that such "packages," however slow and costly, may make smaller families an attractive alternative to the poorest family. The Indian government seems to be looking for a "short-cut," which will require complicated record keeping and readily available health facilities. If India were ready for the successful introduction of compulsory sterilization, it would also be ready for "development" since much the same structure would be required. 相似文献
974.
Neurogranin/RC3 (Ng), a postsynaptic neuronal protein kinase C (PKC) substrate, binds calmodulin (CaM) at low level of Ca2+. In vitro, rat brain Ng can be oxidized by nitric oxide (NO) donors and by oxidants to form an intramolecular disulfide bond with resulting downward mobility shift on nonreducing SDS-polyacrylamide gel electrophoresis. The oxidized Ng, as compared with the reduced form, is a poorer substrate of PKC but like the PKC-phosphorylated Ng has a lower affinity for CaM than the reduced form. To investigate the physiological relevance of Ng oxidation, we tested the effects of neurotransmitter, N-methyl-D-aspartate (NMDA), NO donors, and other oxidants such as hydrogen peroxide and oxidized glutathione on the oxidation of this protein in rat brain slices. Western blot analysis showed that the NMDA-induced oxidation of Ng was rapid and transient, it reached maximum within 3-5 min and declined to base line in 30 min. The response was dose-dependent (EC50 approximately 100 microM) and could be blocked by NMDA-receptor antagonist 2-amino-5-phosphonovaleric acid and by NO synthase inhibitor NG-nitro-L-arginine methyl ester and NG-monomethyl-L-arginine. Ng was oxidized by NO donors, sodium nitroprusside, S-nitroso-N-acetylpenicillamine, and S-nitrosoglutathione, and H2O2 at concentrations less than 0.5 mM. Oxidation of Ng in brain slices induced by sodium nitroprusside could be reversed by dithiothreitol, ascorbic acid, or reduced glutathione. Reversible oxidation and reduction of Ng were also observed in rat brain extracts, in which oxidation was enhanced by Ca2+ and the oxidized Ng could be reduced by NADPH or reduced glutathione. These results suggest that redox of Ng is involved in the NMDA-mediated signaling pathway and that there are enzymes catalyzing the oxidation and reduction of Ng in the brain. We speculate that the redox state of Ng, similar to the state of phosphorylation of this protein, may regulate the level of CaM, which in turn modulates the activities of CaM-dependent enzymes in the neurons. 相似文献
975.
FGF2 promotes neuronal differentiation in explant cultures of adult and embryonic mouse olfactory epithelium 总被引:1,自引:0,他引:1
KP MacDonald WG Murrell PF Bartlett GR Bushell A Mackay-Sim 《Canadian Metallurgical Quarterly》1996,44(1):27-39
Neurogenesis in the adult olfactory epithelium is highly regulated in vivo. Little is known of the molecular signals which control this process, although contact with the olfactory bulb or with astrocytes has been implicated. Explants of mouse olfactory epithelium were grown in the presence or absence of several peptide growth factors. Basic fibroblast growth factor (FGF2) stimulated differentiation of sensory neurons in adult and embryonic olfactory epithelium. Other growth factors tested were ineffective. FGF2-stimulated neurons were born in vitro and expressed neurofilament, neural cell adhesion molecule, and beta-tubulin. The cells also expressed olfactory marker protein, a marker for mature olfactory sensory neurons in vivo. These bipolar neurons did not express glial fibrillary acidic protein or low-affinity nerve growth factor receptor. These results indicate that neither astrocytes nor olfactory bulb are necessary for differentiation of olfactory sensory neurons in vitro. 相似文献
976.
Ensuring drug safety is of paramount importance to the life sciences industry. It's critical that drugs are able not only to achieve the desired result but also to do so without harmful side effects. By identifying problems as early as possible in the drug discovery and development process, life sciences companies can avoid drug safety sagas, such as a recent example that concerned COX-2 inhibitors. Unfortunately, drug safety problems are often revealed only during clinical trials or occasionally after marketing. These challenges are becoming more acute as medicines are targeted to defined patient populations. The life sciences industry can use semantic Web technologies to integrate data more effectively across all drug discovery and development business units, thereby providing a more supportive environment for the early detection of safety-related issues. Effective integration would enable genomic data and patient profiles to be more easily related to safety, thus providing: 1) a simpler framework for determining risk-benefit for individual patients in particular treatment regimens, 2) a better mechanism to distribute new data relating to safety throughout the organization, and 3) a better decision-making environment to determine which drugs to pursue. Furthermore, semantic Web inferencing capabilities enable an intelligent decision support system or autonomous agent to reason about combined domain-specific and industry-specific knowledge and act on the conclusions drawn from this inferencing process. 相似文献
977.
Alician V Quinlan 《Water research》1984,18(5):561-566
Three assumptions were needed to model whole-cell and cell-extract data showing how pH affects the rate and optimum pH of the first step of nitrification: (1) un-ionized ammonia-N is the substrate; (2) substrate ionization occurs; and (3) ampholytic ionization of only the rate-limiting enzyme-substrate complex, and not the free enzyme, controls the rate of ammonia-N oxidation. The rate was shown to obey a Michaelis-Menten rate law where the apparent maximum-velocity coefficient and the apparent half-saturation coefficient with Vm and Km being the Michaelis-Menten maximum-velocity and half-saturation coefficients, respectively; K1 and K2, the acid dissociation coefficients for the enzyme; K3, the acid dissociation coefficient for aqueous ammonium. The optimum pH (pH0) was shown to decrease almost linearly with the logarithm of total ammonia-N concentration over the concentration range found in natural and domestic-waste waters: for N < ppm total ammonia-N. 相似文献
978.
The paper describes a Computer Aided Software Engineering (CASE) tool to support conceptual database modelling. One popular approach for conceptual database modelling is use of the Entity-Relationship (ER) model. The paper proposes the use of an Enhanced Entity-Relationship (EER) model for conceptual database modelling. This Enhanced Entity-Relationship model extends the Entity-Relationship model by incorporating the generalization/specialization, aggregation and categorization abstractions. The CASE tool, which is based on the Enhanced Entity-Relationship model, is known as the Enhanced Entity-Relationship Diagrammer (EERD). In addition, the CASE tool supports direct visual query and update based on the EERM. 相似文献