2,491 research outputs found

    Male Courtship Behavior and Weapon Trait as Indicators of Indirect Benefit in the Bean Bug, Riptortus pedestris

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    Females prefer male traits that are associated with direct and/or indirect benefits to themselves. Male–male competition also drives evolution of male traits that represent competitive ability. Because female choice and male–male competition rarely act independently, exploring how these two mechanisms interact is necessary for integrative understanding of the evolution of sexually selected traits. Here, we focused on direct and indirect benefits to females from male attractiveness, courtship, and weapon characters in the armed bug Riptortus pedestris. The males use their hind legs to fight other males over territory and perform courtship displays for successful copulation. Females of R. pedestris receive no direct benefit from mating with attractive males. On the other hand, we found that male attractiveness, courtship rate, and weapon size were significantly heritable and that male attractiveness had positive genetic covariances with both courtship rate and weapon traits. Thus, females obtain indirect benefits from mating with attractive males by producing sons with high courtship success rates and high competitive ability. Moreover, it is evident that courtship rate and hind leg length act as evaluative cues of female choice. Therefore, female mate choice and male–male competition may facilitate each other in R. pedestris. This is consistent with current basic concepts of sexual selection

    Measurement of focusing properties for high numerical aperture optics using an automated submicron beamprofiler

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    The focusing properties of three aspheric lenses with numerical aperture (NA) between 0.53 and 0.68 were directly measured using an interferometrically referenced scanning knife-edge beam profiler with sub-micron resolution. The results obtained for two of the three lenses tested were in agreement with paraxial gaussian beam theory. It was also found that the highest NA aspheric lens which was designed for 830nm was not diffraction limited at 633nm. This process was automated using motorized translation stages and provides a direct method for testing the design specifications of high numerical aperture optics.Comment: 6 pages 4 figure

    Polyandry and fitness in female horned flour beetles, Gnatocerus cornutus

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    This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Although polyandry is common, it is often unclear why females mate with multiple males, because although polyandry may provide females with direct or indirect fitness benefits, it can also be costly. Our understanding of polyandry is also restricted by the relative paucity of studies that disentangle the fitness effects of mating more than once with a single male and mating with multiple males. Here we investigated potential benefits and costs of polyandry in the horned beetle, Gnatocerus cornutus, while controlling for the number of matings. We found that female life span was independent of mating frequency, indicating that mating itself is not very costly. However, females that mated more than once laid more eggs and had greater lifetime reproductive success than singly mated females. Because the magnitude of these effects was similar in monandrous and polyandrous females, this improved fertility was due to multiple mating itself, rather than mating with multiple males. However, although polyandrous females produced more attractive sons, these males tended to have smaller mandibles and so may fare less well in male-male competition. The se results indicate that polyandry is relatively cost free, at least in the laboratory, and has direct and indirect benefits to female fitness. However, because the attractive sons produced by polyandrous females may fight less well, the indirect benefits of polyandry will depend on the intensity of male-male competition and how free females are to exert mate choice. Where competition between males is intense, polyandry benefits via son attractiveness may be reduced and perhaps even carry costs to female fitness.This study was supported by a Grant-in-Aid for Scientific Research (KAKENHI 25840157) from Japanese Ministry of Education, Science, Sports and Culture. We thank the Editor and referees for helpful comments which greatly improved the manuscript

    Enteral nutrition in dementia: a systematic review

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    The aim of this systematic review is to evaluate the role of enteral nutrition in dementia. The prevalence of dementia is predicted to rise worldwide partly due to an aging population. People with dementia may experience both cognitive and physical complications that impact on their nutritional intake. Malnutrition and weight loss in dementia correlates with cognitive decline and the progress of the disease. An intervention for long term eating difficulties is the provision of enteral nutrition through a Percutaneous Endoscopic Gastrostomy tube to improve both nutritional parameters and quality of life. Enteral nutrition in dementia has traditionally been discouraged, although further understanding of physical, nutritional and quality of life outcomes are required. The following electronic databases were searched: EBSCO Host, MEDLINE, PubMed, Cochrane Database of Systematic Reviews and Google Scholar for publications from 1st January 2008 and up to and including 1st January 2014. Inclusion criteria included the following outcomes: mortality, aspiration pneumonia, pressure sores, nutritional parameters and quality of life. Each study included separate analysis for patients with a diagnosis of dementia and/or neurological disease. Retrospective and prospective observational studies were included. No differences in mortality were found for patients with dementia, without dementia or other neurological disorders. Risk factors for poor survival included decreased or decreasing serum albumin levels, increasing age or over 80 years and male gender. Evidence regarding pneumonia was limited, although did not impact on mortality. No studies explored pressure sores or quality of life

    Optical cavity with a double-layered cholesteric liquid crystal mirror and its prospective application to solid state laser

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    The authors have fabricated an optical cavity with silver (Ag) and double-layered cholesteric liquid crystal (CLC) mirrors facing each other. This CLC mirror consists of left-handed CLC and right-handed CLC films for high light reflection irrespective of polarization states. A single-mode lasing was observed in dye-doped CLC sandwiched between Ag and double-layered CLC mirrors. The authors also fabricated a flexible solid state device with a spin-coated dye molecular film sandwiched between Ag and double-layered CLC mirrors. Amplified spontaneous emission was observed from the solid state device, suggesting a possible structure for a flexible and tunable solid state laser.open

    Erk5 is a mediator to TGFβ1-induced loss of phenotype and function in human podocytes.

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    Background: Podocytes are highly specialized cells integral to the normal functioning kidney, however, in diabetic nephropathy injury occurs leading to a compromised phenotype and podocyte dysfunction which critically produces podocyte loss with subsequent renal impairment. TGFβ1 holds a major role in the development of diabetic nephropathy. Erk5 is an atypical mitogen-activated protein (MAP) kinase involved in pathways modulating cell survival, proliferation, differentiation, and motility. Accordingly, the role of Erk5 in mediating TGFβ1-induced podocyte damage was investigated. Methods: Conditionally immortalized human podocytes were stimulated with TGFβ1 (2.5 ng/ml); inhibition of Erk5 activation was conducted with the chemical inhibitor BIX02188 (10 μM) directed to the upstream Mek5; inhibition of Alk5 was performed with SB431542 (10 μM); Ras signaling was inhibited with farnesylthiosalicylic acid (10 μM). Intracellular signaling proteins were investigated by western blotting; phenotype was explored by immunofluorescence; proliferation was assessed with a MTS assay; motility was examined with a scratch assay; barrier function was studied using electric cell-substrate impedance sensing; apoptosis was studied with annexin V-FITC flow cytometry. Results: Podocytes expressed Erk5 which was phosphorylated by TGFβ1 via Mek5, whilst not involving Ras. TGFβ1 altered podocyte phenotype by decreasing P-cadherin staining and increasing α-SMA, as well as reducing podocyte barrier function; both were prevented by inhibiting Erk5 phosphorylation with BIX02188. TGFβ1-induced podocyte proliferation was prevented by BIX02188, whereas the induced apoptosis was not. Podocyte motility was reduced by BIX02188 alone and further diminished with TGFβ1 co-incubation. Conclusion: These results describe for the first time the expression of Erk5 in podocytes and identify it as a potential target for the treatment of diabetic renal disease

    MYC-type transcription factors, MYC67 and MYC70, interact with ICE1 and negatively regulate cold tolerance in Arabidopsis

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    The expression of hundreds of genes is induced by low temperatures via a cold signaling pathway. ICE1, a MYC-type transcription factor, plays an important role in the induction of CBF3/DREB1A to control cold-responsive genes and cold tolerance. To elucidate other molecular factors, a yeast 2-hybrid screening was performed. Two MYC-type transcription factors, MYC67 and MYC70, were identified as ICE1-interacting proteins. The myc mutants were more tolerant to freezing temperatures than wild type. CBF3/DREB1A and other cold-responsive genes were up-regulated in the myc mutants. Overexpression of the MYC genes increased the cold sensitivity and down-regulated the expression of cold-responsive genes. The MYC proteins interacted with the cis-elements in the CBF3/DREB1A promoter, probably to interfere interaction between ICE1 and the cis-elements. Taken together, these results demonstrate that MYC67 and MYC70, ICE1 interactors, negatively regulate cold-responsive genes and cold tolerance
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