2,127 research outputs found

    Bending properties of finger-jointed Malaysian dark red meranti

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    The mechanical performance of dark red meranti (Shorea spp.) containing structural finger joints was investigated in four-point bending. The influence of variation in density on the bending strength (MOR) and stiffness (MOE) of dark red meranti (DRM) was studied. The effect on these properties of variation in end pressure when bonding was examined. The orientation of finger joints and the effect of cross-sectional area of bonded joints on the bending properties were also investigated. The results of this study indicate a positive relationship between the density and the MOR of DRM specimens. Sufficiently high end pressure is needed to produce strong finger joints. The orientation of finger joints and the changes in cross-sectional area of bonded joints showed no influence on the MOR. The MOE of DRM was not affected by the finger jointing of the pieces. In conclusion, finger-jointed DRM exhibits potential for structural uses, particularly for glulam beams

    Pattern of reading eye movements during monovision contact lens wear in presbyopes

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    Monovision can be used as a method to correct presbyopia with contact lenses (CL) but its effect on reading behavior is still poorly understood. In this study eye movements (EM) were recorded in fifteen presbyopic participants, naïve to monovision, whilst they read arrays of words, non-words, and text passages to assess whether monovision affected their reading. Three conditions were compared, using daily disposable CLs: baseline (near correction in both eyes), conventional monovision (distance correction in the dominant eye, near correction in the non-dominant eye), and crossed monovision (the reversal of conventional monovision). Behavioral measures (reading speed and accuracy) and EM parameters (single fixation duration, number of fixations, dwell time per item, percentage of regressions, and percentage of skipped items) were analyzed. When reading passages, no differences in behavioral and EM measures were seen in any comparison of the three conditions. The number of fixations and dwell time significantly increased for both monovision and crossed monovision with respect to baseline only with word and non-word arrays. It appears that monovision did not appreciably alter visual processing when reading meaningful texts but some limited stress of the EM pattern was observed only with arrays of unrelated or meaningless items under monovision, which require the reader to have more in-depth controlled visual processing

    Lack of association of -607 C/A and -137 G/C polymorphisms in interleukin 18 gene with susceptibility to gout disease in Chinese Han male population

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    To identify association of IL18-607 C/A and -137 G/C polymorphism with susceptibility to gout in Chinese Han male population, We evaluate the genetic contribution of the IL18-607 C/A and -137 G/C polymorphism in 202 gout male patients and 493 gout-free control of Chinese Han population by allele-specific polymerase chain reaction assay. Our results reveal no significant association between the polymorphisms -607C/A and -137G/C in IL18 with gout. Our study might suggest that -607 C/A and -137 G/C polymorphisms in the promoter of IL18 are not associated with susceptibility to gout and thus do not play a major role in the development of gout in the Chinese Han male population

    Classical Effective Field Theory for Weak Ultra Relativistic Scattering

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    Inspired by the problem of Planckian scattering we describe a classical effective field theory for weak ultra relativistic scattering in which field propagation is instantaneous and transverse and the particles' equations of motion localize to the instant of passing. An analogy with the non-relativistic (post-Newtonian) approximation is stressed. The small parameter is identified and power counting rules are established. The theory is applied to reproduce the leading scattering angle for either a scalar interaction field or electro-magnetic or gravitational; to compute some subleading corrections, including the interaction duration; and to allow for non-zero masses. For the gravitational case we present an appropriate decomposition of the gravitational field onto the transverse plane together with its whole non-linear action. On the way we touch upon the relation with the eikonal approximation, some evidence for censorship of quantum gravity, and an algebraic ring structure on 2d Minkowski spacetime.Comment: 29 pages, 2 figures. v4: Duration of interaction is determined in Sec 4 and detailed in App C. Version accepted for publication in JHE

    Phosphorylated c-Src in the nucleus is associated with improved patient outcome in ER-positive breast cancer

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    Elevated c-Src protein expression has been shown in breast cancer and <i>in vitro</i> evidence suggests a role in endocrine resistance. To investigate whether c-Src is involved in endocrine resistance, we examined the expression of both total and activated c-Src in human breast cancer specimens from a cohort of oestrogen receptor (ER)-positive tamoxifen-treated breast cancer patients. Tissue microarray technology was employed to analyse 262 tumour specimens taken before tamoxifen treatment. Immunohistochemistry using total c-Src and activated c-Src antibodies was performed. Kaplan–Meier survival curves were constructed and log-rank test were performed. High level of nuclear activated Src was significantly associated with improved overall survival (<i>P</i>=0.047) and lower recurrence rates on tamoxifen (<i>P</i>=0.02). Improved patient outcome was only seen with activated Src in the nucleus. Nuclear activated Src expression was significantly associated with node-negative disease and a lower NPI (<i>P</i><0.05). On subgroup analysis, only ER-positive/progesterone receptor (PgR)-positive tumours were associated with improved survival (<i>P</i>=0.004). This shows that c-Src activity is increased in breast cancer and that activated Src within the nucleus of ER-positive tumours predicts an improved outcome. In ER/PgR-positive disease, activated Src kinase does not appear to be involved in <i>de novo</i> endocrine resistance. Further study is required in ER-negative breast cancer as this may represent a cohort in which it is associated with poor outcome

    Comparing factors affecting commencement and cessation of betel quid chewing behavior in Taiwanese adults

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    <p>Abstract</p> <p>Background</p> <p>Betel quid is the fourth most common used substance in the world after tobacco, alcohol and caffeine. Although factors related to betel quid chewing or cessation of behaviors were reported previously, few studies simultaneously compared both behaviors in the same population. In addition, it is essential to consider time-to-event concept, since the chance of developing or stopping habit may vary over time. The purpose of this study was to compare the risk factors for commencement and cessation of betel quid chewing behaviors in a time-to-event setting.</p> <p>Methods</p> <p>A stratified multi-stage cluster sampling with selection probabilities proportional to size (PPS) was designed for Taiwanese adults with aged 18 years old and above. Kaplan-Meier estimates and Cox proportional hazard regression models were used to compare and calculate the hazard rate ratios for related factors to commencement or cessation of chewing habits.</p> <p>Results</p> <p>In Taiwan, men had a higher betel quid chewing rate (M: 20.9%, W: 1.2%), but woman chewers had a lower cessation rate (M: 27.5%, W: 12.7%). The hazard rate ratio (HRR) of having chewing habit changed from 4.22 (men vs women) univariately to 1.38 multivariablely, which indicated gender differences were confounded by other factors. In multivariable analysis, the risk factors of gender, education and ethnicity were significantly associated with both starting and cessation of betel quid chewing behavior. The factors of occupation, cigarette smoking and alcohol drinking were only associated with starting habit.</p> <p>Conclusion</p> <p>Commencement or cessation of chewing behavior involves a scenario of time, hence it is preferable to use a time-to-event approach for the comparison. The cessation rates of betel quid chewing were decreasingly associated with the daily consumption of betel quid. Hence, reducing of daily amount in betel quid cessation program may be associated with future stopping habit.</p

    Histone Acetylation-Mediated Regulation of the Hippo Pathway

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    The Hippo pathway is a signaling cascade recently found to play a key role in tumorigenesis therefore understanding the mechanisms that regulate it should open new opportunities for cancer treatment. Available data indicate that this pathway is controlled by signals from cell-cell junctions however the potential role of nuclear regulation has not yet been described. Here we set out to verify this possibility and define putative mechanism(s) by which it might occur. By using a luciferase reporter of the Hippo pathway, we measured the effects of different nuclear targeting drugs and found that chromatin-modifying agents, and to a lesser extent certain DNA damaging drugs, strongly induced activity of the reporter. This effect was not mediated by upstream core components (i.e. Mst, Lats) of the Hippo pathway, but through enhanced levels of the Hippo transducer TAZ. Investigation of the underlying mechanism led to the finding that cancer cell exposure to histone deacetylase inhibitors induced secretion of growth factors and cytokines, which in turn activate Akt and inhibit the GSK3 beta associated protein degradation complex in drug-affected as well as in their neighboring cells. Consequently, expression of EMT genes, cell migration and resistance to therapy were induced. These processes were suppressed by using pyrvinium, a recently described small molecule activator of the GSK 3 beta associated degradation complex. Overall, these findings shed light on a previously unrecognized phenomenon by which certain anti-cancer agents may paradoxically promote tumor progression by facilitating stabilization of the Hippo transducer TAZ and inducing cancer cell migration and resistance to therapy. Pharmacological targeting of the GSK3 beta associated degradation complex may thus represent a unique approach to treat cancer. © 2013 Basu et al

    A Rice Gene of De Novo Origin Negatively Regulates Pathogen-Induced Defense Response

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    How defense genes originated with the evolution of their specific pathogen-responsive traits remains an important problem. It is generally known that a form of duplication can generate new genes, suggesting that a new gene usually evolves from an ancestral gene. However, we show that a new defense gene in plants may evolve by de novo origination, resulting in sophisticated disease-resistant functions in rice. Analyses of gene evolution showed that this new gene, OsDR10, had homologs only in the closest relative, Leersia genus, but not other subfamilies of the grass family; therefore, it is a rice tribe-specific gene that may have originated de novo in the tribe. We further show that this gene may evolve a highly conservative rice-specific function that contributes to the regulation difference between rice and other plant species in response to pathogen infections. Biologic analyses including gene silencing, pathologic analysis, and mutant characterization by transformation showed that the OsDR10-suppressed plants enhanced resistance to a broad spectrum of Xanthomonas oryzae pv. oryzae strains, which cause bacterial blight disease. This enhanced disease resistance was accompanied by increased accumulation of endogenous salicylic acid (SA) and suppressed accumulation of endogenous jasmonic acid (JA) as well as modified expression of a subset of defense-responsive genes functioning both upstream and downstream of SA and JA. These data and analyses provide fresh insights into the new biologic and evolutionary processes of a de novo gene recruited rapidly

    Lead-free piezoelectric K0.5Bi0.5TiO3–Bi(Mg0.5Ti0.5)O3 ceramics with depolarisation temperatures up to ~220 C

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    The properties of K0.5Bi0.5TiO3-rich ceramic solid solutions in the system (1 - x)K0.5Bi0.5TiO3– xBi(Mg0.5Ti0.5)O3 are reported. The highest values of piezoelectric charge coefficient, d33, and field-induced strains are found in compositions located close to a compositional boundary between single-phase tetragonal and mixed tetragonal ? cubic perovskite phases. Maximum d33 values were *150 pC/N for x = 0.03, with positive strains of *0.25 %; the x = 0.04 composition had a d33 * 133 pC/N and strain of 0.35 % (bipolar electric field, 50 kV/ cm, 1 Hz). Depolarisation temperature Td is an important selection criterion for any lead-free piezoelectric for actuator or sensor applications. A Td of *220 C for x = 0.03 is *100 C higher than for the widely reported Na0.5Bi0.5TiO3–BaTiO3 system, yet d33 values and strains are similar, suggesting the new material is worthy of further attention as a lead-free piezoceramic for elevated temperature applications
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