Population erosion and population vigor among unicellular organisms.
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The relationship between leisure-time physical activity (LTPA) and cardiovascular disease (CVD) risk factors was analysed based on data of three cross-sectional National Health Surveys, carried out in West Germany between 1984 and 1991. A total of 7663 males and 7722 females, aged 25-69 years, were examined. A self-administered questionnaire was used to assess LTPA which was defined as the mean duration of time (in minutes) spent during the past week on 14 specified sports during the previous 3 months. The mean time for LTPA per week was 102 minutes for males and 70 minutes for females. No significant differences were observed in LTPA mean duration for the three surveys. Younger age and higher social class were strong predictors for greater LTPA. In multiple linear regression models, after adjustment for age and social class, LTPA was significantly associated with lower systolic and diastolic blood pressure (both sexes), total cholesterol (males only), cigarette smoking (males only) and body mass index (females only), and with higher HDL-cholesterol (both sexes). The data suggest that LTPA plays an important role if aiming at reducing CVD risk factors in the general population.
Old trees of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and lodgepole pine (Pinus contorta var. latifolia Engelm.) were studied to determine volume growth patterns in relation to leaf area. Ponderosa pine trees varied in age from 166 to 432 years and were about 77 cm in diameter; lodgepole pine trees varied in age from 250 to 296 years and were about 31 cm in diameter. With the exception of several ponderosa pine trees less than 200 years old, trees of both species had flattened tops, heavy branches, and foliage distribution characteristically found only in the oldest trees. After trees were felled, annual volume increments were determined from crossdated radial increments measured on discs at 4-m height intervals, and leaf areas were determined based on leaf area/branch sapwood area ratios for 1/5 sections of the crown for each tree. In ponderosa pine, three distinct volume growth patterns occurred: (1) a gradual increase in annual volume growth until felling; (2) a more rapid increase in growth to a plateau that persisted for a century or more; and (3) a rapid increase in growth followed by a generally sudden decrease in growth to less than half the earlier rates, and persisting at these lower rates for as long as seven decades. In lodgepole pine, fewer trees exhibited the sudden growth decline observed in ponderosa pine. Most short-term growth variations in ponderosa pine were synchronized among all trees, suggesting a common climatic signal. In lodgepole pine, annual variations in volume growth were slight. Volume growth in the most recent years before felling was weakly correlated with leaf area at the time of felling (r(2) = 0.45 for both species). However, in both species, trees having a high volume growth rate and leaf area at the time of felling had grown slowly when young, whereas trees having low volume growth rate and leaf area at felling grew rapidly when young. Thus a wide range of early and late growth patterns can lead to old-growth conditions in these species. Growth efficiencies (grams of dry matter per m(2) total leaf area) were generally higher for trees having the lowest leaf areas, and in almost all cases were below 100 g m(-2).
The impact of feeding by the western conifer seed bug (Leptoglossus occidentalis Heidemann) on storage reserves of developing seeds of Douglas-fir (Pseudostuga menziesii (Mirb.) Franco) was studied by caging nymphal and adult seed bugs on cones during late-season development, and nymphs on cones during early, mid- and late-season development. Analysis of the major storage reserves of partially damaged seeds revealed that late-season feeding by each life stage and feeding by nymphs at all three stages of cone development significantly reduced the amounts of lipid and buffer-insoluble (crystalloid) protein in seeds at harvest by up to 78 and 97%, respectively. Seeds showing light to moderate damage on radiographs did not exhibit a reduction in the amount of buffer-soluble (matrix) protein. Seeds damaged by feeding during early development compensated in part by continuing to synthesize lipid and crystalloid protein. Light or moderate damage to mature Douglas-fir seeds exposed to L. occidentalis in the laboratory reduced seedling emergence by > 80%, but the seedlings that emerged successfully appeared to suffer no adverse effects when grown under standard nursery conditions.
To clarify the physiological basis of productivity differences among rooted cuttings and seedlings of eucalypt species, relationships between morphology and water relations were examined in 4-month-old seedlings of Eucalyptus grandis W. Hill ex Maiden, E. urophylla S.T. Blake and E. cloeziana F. Muell. and in 4-month-old rooted cuttings of three E. grandis cultivars. Four-month-old seedlings had greater dry weights, lower leaf area/root dry weight (LA/RDW) ratios and lower shoot/root dry weight (S/R) ratios than 4-month-old rooted cuttings. For all cultivars of E. grandis, tall rooted cuttings, as defined by height at age 4 weeks, had greater dry weights by age 4 months and lower LA/RDW and S/R ratios than short rooted cuttings. There were differences in height growth, dry matter productivity and relative shoot and root development among cuttings of different E. grandis cultivars, but these differences were not as great as the differences between short and tall grades of the same cultivar and between seedlings and cuttings. Consistent with the differences in LA/RDW and S/R ratios, seedlings had higher daytime water potentials (Psi(x)) than cuttings, and tall cuttings had higher daytime values of Psi(x) than short cuttings. Differences in Psi(x) were also related to stomatal conductance (g(wv)), which was up to 300% greater in short cuttings than in tall cuttings. Among seedlings, those of E. cloeziana, which had the smallest dry weight at age 4 months, had the highest g(wv), whereas those of E. grandis, which had the greatest dry weight at age 4 months, had the lowest g(wv). Unlike seedlings and the tall cuttings, short cuttings lost turgor when subjected to drought. The differences observed in susceptibility to water stress may account in part for the associated differences in dry matter production. Xylem pressure potential and relative water deficit at zero turgor did not differ significantly among the types of plants studied, which suggests that differences in growth rates were not the result of differences in dehydration tolerance.
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Currently 17 million Americans have diabetes mellitus (DM); 90% of these have type 2 DM. Of these 17 million, 5.9 million remain undiagnosed. The undiagnosed patient with type 2 DM may be asymptomatic for years, while hyperglycemic injury to target organs occurs long before the development of frank diabetes. The prevalence of diabetes among adults is estimated to increase to almost double the present number by 2025. People with diabetes and at risk for diabetes are also at risk for cardiovascular disease. Several investigators have now demonstrated the benefit of controlling blood glucose levels as well as other risk factors in this population to decrease the incidence of microvascular and macrovascular disease. Prevention or delaying the onset of type 2 DM can be accomplished with a program of diet, weight loss, and exercise.
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Specific identifications by immunofluorescence of infecting organisms and lymphoid cells in lymphoid organs and testes of rabbits were compared with the light microscopic appearances of these cells and organs on days 10, 11, 13, and 20 after intratesticular inoculation with Treponema pallidum (Nichols strain). Large numbers of T. pallidum were observed in the interstitial tissues of the testes on days 10 and 11. These numbers had declined markedly by day 13, and by day 20 only rare organisms (estimated as fewer than one to three per cross section) were seen. Organisms were also easily identified in much smaller numbers in the lymph nodes and spleen on days 13 and 20. Disappearance of organisms from the testes were associated with infiltration of large numbers of T cells. Marked follicular and diffuse cortical hyperplasia of the lymph nodes as well as follicular and periarterial hyperplasia of the spleen were observed. Specific immunofluorescence revealed large numbers of T cells in the diffuse cortex of the lymph nodes and the periarteriolar zones of the spleen. There was also a periportal infiltration of T cells in the liver. It is concluded that rabbits infected intratesticularly with T. pallidum mount an intense immune response that effectively eliminates most of the infecting organisms. However, despite this response, surviving T. pallidum may be identified not only at the original site of infection, but also disseminated in lymphoid organs. Normal mechanisms for controlling immune responses apparently shut down the specific response at a time when infecting organisms have not been completely eradicated from the host's tissues.
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A bacterial strain, designated AST4(T), was isolated from activated sludge. The bacterium did not show significant growth on nutrient broth, but growth was clearly stimulated by addition of supernatant from other bacterial cultures. Culture filtrate of a strain related to the genus Sphingomonas in particular increased the cell yield and growth rate of strain AST4(T). Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain AST4(T) is located within the 'Rhodobacter group' in the alpha-3 subclass of Proteobacteria, but is clearly distant from related genera in this group such as Paracoccus, Rhodobacter and Rhodovulum. Strain AST4(T) is a Gram-negative, non-motile, rod-shaped (0.6-0.8x1.3-2.0 micro m) and aerobic bacterium. It was not able to reduce nitrate to nitrite or N(2). No phototrophic growth was observed. Optimal growth occurred at 30 degrees C and pH 6.5-7.5. The dominant cellular fatty acid in the isolate was C(18 : 1)cis11. Ubiquinone-10 was the major respiratory quinone. The G+C content was 64.5 mol% (by HPLC). Based on the phylogenetic and phenotypic traits, the name Catellibacterium nectariphilum gen. nov., sp. nov. is proposed for this isolate; the type strain is AST4(T) (=NBRC 100046(T)=JCM 11959(T)=DSM 15620(T)).
Toll-like receptor 3 (TLR-3) and TLR-9 gene expression and interleukin 6 (IL-6) secretion were studied in corneal cells with components of herpes simplex virus (HSV). Human corneal epithelial cells (HCEs) and primary human corneal fibroblasts (HCRFs) were infected with live HSV or UV-inactivated HSV (UV-HSV), transfected with HSV DNA or treated with HSV-anti-HSV IgG immune complexes. Gene expression of TLR-3 and -9 was analysed by real-time PCR. Supernatants were assayed for IL-6 by ELISA. Incubation of HCEs and HCRFs with live HSV-1, UV-HSV and HSV DNA resulted in augmented TLR-3 and -9 gene expression and IL-6 release. Moreover, infected or transfected HCRFs released greater amounts of IL-6 than did HCEs. As virus is frequently in the form of neutralized virus immune complexes, the ability of these immune complexes to interact with TLRs and trigger IL-6 production was evaluated. Here, it is shown that HSV-anti-HSV IgG complexes were as potent as HSV DNA in their ability to induce IL-6. Treatment of HCRFs transfected with HSV DNA with the TLR-9-inhibitory oligomer iODN, anti-TLR-3 antibody or phosphatidylinositol 3-kinase inhibitor indicated that IL-6 release from HCRFs was mediated by TLR-3 and -9 gene expression. These results demonstrated that neutralized HSV immune complexes were as potent as HSV DNA in enhancing IL-6 release from corneal fibroblasts. These phenomena were mediated via augmented TLR-3 and -9 gene expression.