53 research outputs found

    Abundances of Iron-Binding Photosynthetic and Nitrogen-Fixing Proteins of Trichodesmium Both in Culture and In Situ from the North Atlantic

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    Marine cyanobacteria of the genus Trichodesmium occur throughout the oligotrophic tropical and subtropical oceans, where they can dominate the diazotrophic community in regions with high inputs of the trace metal iron (Fe). Iron is necessary for the functionality of enzymes involved in the processes of both photosynthesis and nitrogen fixation. We combined laboratory and field-based quantifications of the absolute concentrations of key enzymes involved in both photosynthesis and nitrogen fixation to determine how Trichodesmium allocates resources to these processes. We determined that protein level responses of Trichodesmium to iron-starvation involve down-regulation of the nitrogen fixation apparatus. In contrast, the photosynthetic apparatus is largely maintained, although re-arrangements do occur, including accumulation of the iron-stress-induced chlorophyll-binding protein IsiA. Data from natural populations of Trichodesmium spp. collected in the North Atlantic demonstrated a protein profile similar to iron-starved Trichodesmium in culture, suggestive of acclimation towards a minimal iron requirement even within an oceanic region receiving a high iron-flux. Estimates of cellular metabolic iron requirements are consistent with the availability of this trace metal playing a major role in restricting the biomass and activity of Trichodesmium throughout much of the subtropical ocean

    Honey, a Gift from Nature to Health and Beauty: A Review

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    Benefits of honey are contributed by the composition of its elements such as glucose, fructose, glucose oxidase, vitamins and phenolic compounds. For health, honey can be used to treat wounds due to the antibacterial activity conferred by the hydrogen peroxide produced by glucose oxidase in honey. Anti-inflammatory, anti-oxidant, deodorizing and tissue regeneration activities in honey also help in the wound healing process. It can also be an alternative sweetener for diabetic patients to ensure compliance to a healthy diet. Moreover, honey exerts several effects such as lowering low density lipids and increasing high density lipids, thus reducing risk of atherosclerosis. In terms of beauty, honey can be used on skin and hair. It moisturizes skin through its natural humectant properties contributed by high contents of fructose and glucose. Honey treats acne on the skin due to its antibacterial activity, anti-inflammatory action and tissue repair. The hair can benefit from honey in such a way that the hair has abundance, and becomes easier to comb. However, there have not been as many studies regarding the use of honey in skin in comparison to its use for health. Therefore, future studies on honey could research its use, action and benefits in both cosmetics and dermatology

    Transgenerational effects of maternal sexual interactions in seed beetles

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    Mating often bears large costs to females, especially in species with high levels of sexual conflict over mating rates. Given the direct costs to females associated with multiple mating, which include reductions in lifespan and lifetime reproductive success, past research focused on identifying potential indirect benefits (through increases in offspring fitness) that females may accrue. Far less attention has, however, been devoted to understanding how costs of sexual interactions to females may extend across generations. Hence, little is known about the transgenerational implications of variation in mating rates, or the net consequences of maternal sexual activities across generations. Using the seed beetle, Callosobruchus maculatus, a model system for the study of sexual conflict, we investigate the effects of mating with multiple males versus a single male, and tease apart effects due to sexual harassment and those due to mating per se, over three generations. A multigenerational analysis indicated that females that were exposed to ongoing sexual harassment and who also were permitted to mate with multiple males showed no difference in net fitness compared to females that mated just once without ongoing harassment. Intriguingly, however, females that were continually harassed, but permitted to mate just once, suffered a severe decline in net fitness compared to females that were singly (not harassed) or multiply mated (harassed, but potentially gaining benefits via mating with multiple males). Overall, the enhanced fitness in multiply mated compared to harassed females may indicate that multiple mating confers transgenerational benefits. These benefits may counteract, but do not exceed (i.e., we found no difference between singly and multiply mated females), the large transgenerational costs of harassment. Our study highlights the importance of examining transgenerational effects from an inclusive (looking at both indirect benefits but also costs) perspective, and the need to investigate transgenerational effects across several generations if we are to fully understand the consequences of sexual interactions, sexual conflict evolution, and the interplay of sexual conflict and multi-generational costs and benefits

    Agrobacterium-mediated transformation of Sclerotinia sclerotiorum

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    Ascospores from the phytopathogenic fungus Sclerotinia sclerotiorum were transformed to hygromycin B resistance by cocultivation with Agrobacterium tumefaciens. Transformed spores germinated and grew on PDA supplemented with 100 ug/ml hygromycin B. The presence of mitotically stable hph gene integration at random sites in the genome was confirmed by PCR and Southern blot analysis. A transformation frequency of 8105 was achieved in five separate experiments. This study is the first report of success co-cultivating A. tumefaciens with S. sclerotiorum. This report of a reproducible Agrobacterium-mediated transformation method should allow the development of T-DNA tagging as a system for insertional mutagenesis in S. sclerotiorum and provide a simple and reliable method for genetic manipulation

    The management of acne vulgaris in primary care: a cohort study of consulting and prescribing patterns using the Clinical Practice Research Datalink.

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    Background Effective management of acne vulgaris in primary care involves support (usually provided over a number of consultations) and prescription of effective treatments. However, consulting and prescribing patterns for acne in primary care are not well described. Objectives To describe the rate of primary-care consultations and follow-up consultations; prescribing patterns, including overall use of acne-related medications (ARMs); and initial and follow-up prescription for acne vulgaris in the U.K. Methods U.K. primary-care acne consultations and prescriptions for ARMs were identified in the Clinical Practice Research Datalink. Annual consultation rates (between 2004 and 2013) by age and sex, new consultations and consultations in the subsequent year were calculated, along with prescribing trends – during a new consultation and over the subsequent 90 days and year – using the number of registered patients as the denominator. Results Two-thirds (66.1%) of patients who had a new acne consultation had no further acne consultations in the subsequent year. Overall 26.7%, 24.9%, and 23.6% and 2.8% of patients were prescribed no ARM, an oral antibiotic, a topical antibiotic or an oral plus topical antibiotic, respectively, during a new acne consultation. In total 60.1% and 38.6% of patients prescribed an ARM received no further ARM prescriptions in the following 90 days and 1 year, respectively, despite most prescriptions being for 2 months or less. Prescribing rates for lymecycline and topical combined clindamycin and benzoyl peroxide increased substantially between 2004 and 2013. There were no important changes in consultation rates between 2004 and 2013. Conclusions These data suggest that patients with acne are receiving a suboptimal initial choice of ARMs, longitudinal care and prescribing.</p

    Another twist on nitrogenases

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