228 research outputs found

    Grapevine trunk disease in German viticulture II. Associated fungi occurring on non-Vitis hosts, and first report of Phaeoacremonium angustius

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    Fifteen species of wood colonizing fungi are presented that have been collected from various non-Vitis hosts in the vicinity of vineyards located in southern Palatinate, Germany. Information is provided on their geographic distribution, epidemiology, host range, life strategy, symptoms and diagnosis. Their role as possible pathogens within the complex of grapevine trunk diseases (GTDs) is discussed. The following species are reported for the first time in Germany: Botryosphaeria sarmentorum, Cadophora malorum, Cadophora novi-eboraci, Collophora africana, Collophora hispanica, Cytospora chrysosperma, Diaporthe foeniculina, Dothiorella iberica, and Phaeoacremonium angustius. Diplodia seriata, Diplodia mutila, Dothiorella iberica, Cytospora chrysosperma, and Dothiorella iberica were proven by airborne inoculum, and could be demonstrated throughout the duration of our study, i.e. from March through September. The study points to a possible significance of non-Vitis hosts as additional inoculum source in GTDs. Also, the existence of airborne spores early in the year might be relevant with regard to the pruning period of vines

    Chloroplast-localized 6-phosphogluconate dehydrogenase is critical for maize endosperm starch accumulation

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    Plants have duplicate versions of the oxidative pentose phosphate pathway (oxPPP) enzymes with a subset localized to the chloroplast. The chloroplast oxPPP provides NADPH and pentose sugars for multiple metabolic pathways. This study identified two loss-of-function alleles of the Zea mays (maize) chloroplast-localized oxPPP enzyme 6-phosphogluconate dehydrogenase (6PGDH). These mutations caused a rough endosperm seed phenotype with reduced embryo oil and endosperm starch. Genetic translocation experiments showed that pgd3 has separate, essential roles in both endosperm and embryo development. Endosperm metabolite profiling experiments indicated that pgd3 shifts redox-related metabolites and increases reducing sugars similar to starch-biosynthetis mutants. Heavy isotope-labelling experiments indicates that carbon flux into starch is altered in pgd3 mutants. Labelling experiments with a loss of cytosolic 6PGDH did not affect flux into starch. These results support the known role for plastid-localized oxPPP in oil synthesis and argue that amyloplast-localized oxPPP reactions are integral to endosperm starch accumulation in maize kernels

    Polarization investigation of a tunable high-speed short-wavelength bulk-micromachined MEMS-VCSEL

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    We report the investigation of the state of polarization (SOP) of a tunable vertical-cavity surface-emitting laser (VCSEL) operating near 850 nm with a mode-hop free single-mode tuning range of about 12 nm and an amplitude modulation bandwidth of about 5 GHz. In addition, the effect of a sub-wavelength grating on the device and its influence on the polarization stability and polarization switching has been investigated. The VCSEL with an integrated sub-wavelength grating shows a stable SOP with a polarization mode suppression ratio (PMSR) more than 35 dB during the tuning

    Universal switching of plasmonic signals using optical resonator modes

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    We propose and investigate, both experimentally and theoretically, a novel mechanism for switching and modulating plasmonic signals based on a Fano interference process, which arises from the coupling between a narrow-band optical Fabry–Pérot cavity and a surface plasmon polariton (SPP) source. The SPP wave emitted from the cavity is actively modulated in the vicinity of the cavity resonances by altering the cavity Q-factor and/or resonant frequencies. We experimentally demonstrate dynamic SPP modulation both by mechanical control of the cavity length and all-optically by harnessing the ultrafast nonlinearity of the Au mirrors that form the cavity. An electro-optical modulation scheme is also proposed and numerically illustrated. Dynamic operation of the switch via mechanical means yields a modulation in the SPP coupling efficiency of ~ 80%, while the all-optical control provides an ultrafast modulation with an efficiency of 30% at a rate of ~ 0.6 THz. The experimental observations are supported by both analytical and numerical calculations of the mechanical, all-optical and electro-optical modulation methods

    Using Cognitive Interviewing for the Semantic Enhancement of Multi-Lingual Versions of Personality Questionnaires

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    We discuss the use of cognitive interviewing with bilinguals as an integral part of cross-cultural adaptation of personality questionnaires. The aim is to maximize semantic equivalence to increase the likelihood of items maintaining the intended structure and meaning in the target language. We refer to this part of adaptation as semantic enhancement, and integrate cognitive interviewing within it as a tool for scrutinizing translations, the connotative meaning, and the psychological impact of items across languages. During the adaptation of a work-based personality questionnaire from English to Arabic, Chinese (Mandarin), and Spanish, we cognitively interviewed 12 bilingual participants about 136 items in different languages (17% of all items), of which 67 were changed. A content analysis categorizing the reasons for amending items elicited eleven errors that affect two identified forms of semantic equivalence. We provide the resultant coding scheme as a framework for designing cognitive interviewing protocols and propose a procedure for implementing them. We discuss implications for theory and practic

    Сутність та класифікація ризиків інвестиційної діяльності

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    Наводиться визначення поняттю "ризики інвестиційної діяльності" за рахунок поєднання його сутнісних характеристик, виконано узагальнення класифікації цих ризиків, запропоновано введення нової класифікаційної групи – "корпоративні ризики", які пов'язані з можливістю втрати контролю над підприємством інвестором-акціонером

    New Alloying Systems for Sintered Steels: Critical Aspects of Sintering Behavior

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    Oxygen-sensitive alloying elements such as Mn, Si, and Cr have a high potential for improving the properties of low alloyed sintered steels while reducing the alloying cost. However, it is necessary to find a way for avoiding, or at least minimizing, the oxidation of these elements especially during the early stages of the sintering cycle. In this study Mn, Si, and Cr were introduced in the form of a master alloy powder designed to be mixed with the iron base powder and provide the final composition of the steel during the sintering process. The reduction/oxidation phenomena taking place during the heating stage were studied by thermogravimetry, dilatometry, and mass spectroscopy, using either reducing (H2) or inert (Ar) atmospheres. The results show how the difference in chemical activity between base iron powder and master alloy causes the so called "internal-getter" effect, by which the reduction of less stable iron oxides leads to oxidation of the elements with higher affinity for oxygen. This effect can be somehow minimized when sintering in H2, since the iron oxides are reduced at lower temperatures at which the reactivity of the elements in the master alloy is lower. However, H2 concentration in the processing atmosphere needs to be carefully adapted to the specific composition of the materials being processed in order to minimize decarburization by methane formation during sintering.Höganäs AB Sweden, financial support provided through the Höganäs Chair IVPublicad

    Multi-tier Loyalty Programs to Stimulate Customer Engagement

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    Customers differ in their purchase behavior, profitability, attitude toward the firm, and so on. These differences between customers have led to numerous firms introducing multi-tier loyalty programs. A multi-tier loyalty program explicitly distinguishes between customers by means of hierarchical tiers (e.g. Silver, Gold, Platinum) and assigns customers to different tiers based on their past purchase behavior. Next, customers in different tiers are provided varying levels of tangible rewards and intangible benefits, which are potentially powerful instruments to stimulate customer engagement. In this chapter, we focus on the design and effectiveness of such multi-tier loyalty programs. Building on loyalty program and customer prioritization research, we discuss whether, why, and how multi-tier loyalty programs are effective (or not) in influencing customer behavior, thereby enhancing customer engagement and financial performance

    Variants in the FFAR1 Gene Are Associated with Beta Cell Function

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    The FFAR1 receptor is expressed mainly in pancreatic beta cells and is activated by medium to long chain free fatty acids (FFAs), as well as by thiazolidinediones, resulting in elevated Ca(2+) concentrations and promotion of insulin secretion. These properties suggest that FFAR1 could be a mediator of lipotoxicity and a potential candidate gene for Type 2 diabetes (T2D). We therefore investigated whether variations at the FFAR1 locus are associated with T2D and beta cell function.We re-sequenced the FFAR1 region in 96 subjects (48 healthy and 48 T2D individuals) and found 13 single nucleotide polymorphisms (SNPs) 8 of which were not previously described. Two SNPs located in the upstream region of the FFAR1 gene (rs1978013 and rs1978014) were chosen and genotyped in 1929 patients with T2D and 1405 healthy control subjects. We observed an association of rs1978013 and rs1978014 with insulinogenic index in males (p = 0.024) and females (p = 0.032), respectively. After Bonferroni corrections, no association with T2D was found in the case-control material, however a haplotype consisting of the T-G alleles conferred protection against T2D (p = 0.0010).Variation in the FFAR1 gene may contribute to impaired beta cell function in T2D

    Validation of the conceptual research utilization scale: an application of the standards for educational and psychological testing in healthcare

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    <p>Abstract</p> <p>Background</p> <p>There is a lack of acceptable, reliable, and valid survey instruments to measure conceptual research utilization (CRU). In this study, we investigated the psychometric properties of a newly developed scale (the CRU Scale).</p> <p>Methods</p> <p>We used the <it>Standards for Educational and Psychological Testing </it>as a validation framework to assess four sources of validity evidence: content, response processes, internal structure, and relations to other variables. A panel of nine international research utilization experts performed a formal content validity assessment. To determine response process validity, we conducted a series of one-on-one scale administration sessions with 10 healthcare aides. Internal structure and relations to other variables validity was examined using CRU Scale response data from a sample of 707 healthcare aides working in 30 urban Canadian nursing homes. Principal components analysis and confirmatory factor analyses were conducted to determine internal structure. Relations to other variables were examined using: (1) bivariate correlations; (2) change in mean values of CRU with increasing levels of other kinds of research utilization; and (3) multivariate linear regression.</p> <p>Results</p> <p>Content validity index scores for the five items ranged from 0.55 to 1.00. The principal components analysis predicted a 5-item 1-factor model. This was inconsistent with the findings from the confirmatory factor analysis, which showed best fit for a 4-item 1-factor model. Bivariate associations between CRU and other kinds of research utilization were statistically significant (p < 0.01) for the latent CRU scale score and all five CRU items. The CRU scale score was also shown to be significant predictor of overall research utilization in multivariate linear regression.</p> <p>Conclusions</p> <p>The CRU scale showed acceptable initial psychometric properties with respect to responses from healthcare aides in nursing homes. Based on our validity, reliability, and acceptability analyses, we recommend using a reduced (four-item) version of the CRU scale to yield sound assessments of CRU by healthcare aides. Refinement to the wording of one item is also needed. Planned future research will include: latent scale scoring, identification of variables that predict and are outcomes to conceptual research use, and longitudinal work to determine CRU Scale sensitivity to change.</p
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