1,074 research outputs found

    Kannapolis: From Mill Town to Research-Based Economy

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    Kannapolis is a thriving city of 43,115 people located along the 1-85 corridor in the Charlotte region of North Carolina. It began as a mill community in 1906 when J.W. Cannon purchased 808 acres of former cotton fields and began construction of “Cannon’s model mill town,” which ambitiously became known as Kannapolis. In its first year of operation, Cannon built two manufacturing plants and 75 homes for carpenters and construction workers. Shortly thereafter, 75 additional homes were built for the first wave of textile workers who came to the area with the promise of new opportunities. By 1920, the population of the community had grown to 5,027 men, women and children, living in 821 new houses. The mill employees resided in the homes, paying low rental rates and enjoying free maintenance, low cost utilities, free garbage collection, and no taxes

    Photosynthetic Adaptation to Length of Day Is Dependent on S-Sulfocysteine Synthase Activity in the Thylakoid Lumen

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    Abstract Arabidopsis (Arabidopsis thaliana) chloroplasts contain two O-acetyl-serine(thiol)lyase (OASTL) homologs, OAS-B, which is an authentic OASTL, and CS26, which has S-sulfocysteine synthase activity. In contrast with OAS-B, the loss of CS26 function resulted in dramatic phenotypic changes, which were dependent on the light treatment. We have performed a detailed characterization of the photosynthetic and chlorophyll fluorescence parameters in cs26 plants compared with those of wild-type plants under short-day growth conditions (SD) and long-day growth conditions (LD). Under LD, the photosynthetic characterization, which was based on substomatal CO2 concentrations and CO2 concentration in the chloroplast curves, revealed significant reductions in most of the photosynthetic parameters for cs26, which were unchanged under SD. These parameters included net CO2 assimilation rate, mesophyll conductance, and mitochondrial respiration at darkness. The analysis also showed that cs26 under LD required more absorbed quanta per driven electron flux and fixed CO2. The nonphotochemical quenching values suggested that in cs26 plants, the excess electrons that are not used in photochemical reactions may form reactive oxygen species. A photoinhibitory effect was confirmed by the background fluorescence signal values under LD and SD, which were higher in young leaves compared with mature ones under SD. To hypothesize the role of CS26 in relation to the photosynthetic machinery, we addressed its location inside of the chloroplast. The activity determination and localization analyses that were performed using immunoblotting indicated the presence of an active CS26 enzyme exclusively in the thylakoid lumen. This finding was reinforced by the observation of marked alterations in many lumenal proteins in the cs26 mutant compared with the wild type.</jats:p

    Patterns of geohelminth infection, impact of albendazole treatment and re-infection after treatment in schoolchildren from rural KwaZulu-Natal/South-Africa

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    BACKGROUND: Geohelminth infection is a major health problem of children from rural areas of developing countries. In an attempt to reduce this burden, the Department of Health of the province of KwaZulu-Natal (KZN) established in 1998 a programme for helminth control that aimed at regularly treating primary school children for schistosomiasis and intestinal helminths. This article describes the baseline situation and the effect of treatment on geohelminth infection in a rural part of the province. METHODS: Grade 3 schoolchildren from Maputaland in northern KZN were examined for infections with hookworm, Ascaris lumbricoides, and Trichuris trichiura, treated twice with 400 mg albendazole and re-examined several times over one year after the first treatment in order to assess the impact of treatment and patterns of infection and re-infection. RESULTS: The hookworm prevalence in the study population (83.2%) was considerably higher than in other parts of the province whereas T. trichiura and especially A. lumbricoides prevalences (57.2 and 19.4%, respectively) were much lower than elsewhere on the KZN coastal plain. Single dose treatment with albendazole was very effective against hookworm and A. lumbricoides with cure rates (CR) of 78.8 and 96.4% and egg reduction rates (ERR) of 93.2 and 97.7%, respectively. It was exceptionally ineffective against T. trichiura (CR = 12.7%, ERR = 24.8%). Re-infection with hookworm and A. lumbricoides over 29 weeks after treatment was considerable but still well below pre-treatment levels. CONCLUSION: High geohelminth prevalences and re-infection rates in the study population confirm the need for regular treatment of primary school children in the area. The low effectiveness of single course albendazole treatment against T. trichiura infection however demands consideration of alternative treatment approaches

    Seasonal variation of water uptake of a Quercus suber tree in Central Portugal

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    Hydraulic redistribution (HR) is the phenomenon where plant roots transfer water between soil horizons of different water potential. When dry soil is a stronger sink for water loss from the plant than transpiration, water absorbed by roots in wetter soil horizons is transferred toward, and exuded into dry soil via flow reversals through the roots. Reverse flow is a good marker of HR and can serve as a useful tool to study it over the long-term. Seasonal variation of water uptake of a Quercus suber tree was studied from late winter through autumn 2003 at Rio Frio near Lisbon, Portugal. Sap flow was measured in five small shallow roots (diameter of 3–4 cm), 1 to 2 m from the tree trunk and in four azimuths and at different xylem depths at the trunk base, using the heat field deformation method (HFD). The pattern of sap flow differed among lateral roots as soil dried with constant positive flow in three roots and reverse flow in two other roots during the night when transpiration ceased. Rain modified the pattern of flow in these two roots by eliminating reverse flow and substantially increasing water uptake for transpiration during the day. The increase in water uptake in three other roots following rain was not so substantial. In addition, the flux in individual roots was correlated to different degrees with the flux at different radial depths and azimuthal directions in trunk xylem. The flow in outer trunk xylem seemed to be mostly consistent with water movement from surface soil horizons, whereas deep roots seemed to supply water to the whole cross-section of sapwood. When water flow substantially decreased in shallow lateral roots and the outer stem xylem during drought, water flow in the inner sapwood was maintained, presumably due to its direct connection to deep roots. Results also suggest the importance of the sap flow sensor placement, in relation to sinker roots, as to whether lateral roots might be found to exhibit reverse flow during drought. This study is consistent with the dimorphic rooting habit of Quercus suber trees in which deep roots access groundwater to supply superficial roots and the whole tree, when shallow soil layers were dry
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