323 research outputs found

    A fractal-based fibre for ultra-high throughput optical probes

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    A core component of all scanning near-field optical microscopy (SNOM) systems is the optical probe, which has evolved greatly but still represents the limiting component for the system. Here, we introduce a new type of optical probe, based on a Fractal Fibre which is a special class of photonic crystal fibre (PCF), to directly address the issue of increasing the optical throughput in SNOM probes. Optical measurements through the Fractal Fibre probes have shown superior power levels to that of conventional SNOM probes. The results presented in this paper suggest that a novel fibre design is critical in order to maximize the potential of the SNOM

    Pteridine modulation of lead inhibition of uroporphyrinogen synthesis in erythroid precursor cells

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    The role of nutritional factors on heme synthesis and their influence on the development of anemia in the bone marrow during lead exposure is unclear. Previous reports suggested that pteridines could regulate the formation of uroporphyrinogen, a step midway along the heme synthetic pathway. Studies were undertaken to determine if pteridines could modulate lead inhibition of uroporphyrinogen synthesis in erythroid precursor cells. Pteroylpolyglutamates of various glutamate chain lengths were tested for the ability to protect against lead inhibition of uroporphyrinogen I (URO) synthase prepared from murine erythroleukemia cells (MELC). Pteroylpentaglutamate, the major endogenous polyglutamate form by chain length found to be present in MELC, afforded rapid and specific protection of URO synthase against lead inhibition. MELC are expected to be a useful in vitro model for studying the role of endogenous folates on uroporphyrinogen synthesis and heme formation in erythroid precursor cells following lead exposure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28691/1/0000511.pd

    Negative emotions in informal feedback: The benefits of disappointment and drawbacks of anger

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    Using the emotions as social information (EASI) model, this study investigated the emotional, attitudinal and behavioral reactions to failure feedback by manipulating negative emotional displays (angry, disappointed or none) and the position level and relational distance of the feedback source. Undergraduate students (N = 260) responded to an organizational failure feedback vignette and completed a subsequent performance task. Results demonstrated that guilt was the complementary emotional experience following displays of disappointment, while reciprocal anger followed displays of anger. These emotional reactions served as important mediators between the emotional displays paired with the feedback message and participant responses of social behaviors, creative task performance and perceptions of the feedback source. In addition, our findings indicated that negative emotions can have positive organizational and interpersonal outcomes. Guilt in response to disappointed displays resulted in beneficial behaviors and attitudes, while anger in response to angry displays was socially detrimental. The emotion displayed during feedback provision also served as a consistent contextual factor that did not interact with the position level or relational distance of the feedback source to impact behavioral and attitudinal reactions. Overall, this study indicates that discrete negative emotions have unique social-functional properties that require further investigation.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Alphabetic Letter Identification: Effects of perceivability, similarity, and bias

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    The legibility of the letters in the Latin alphabet has been measured numerous times since the beginning of\ud experimental psychology. To identify the theoretical mechanisms attributed to letter identification, we report\ud a comprehensive review of literature, spanning more than a century. This review revealed that identification\ud accuracy has frequently been attributed to a subset of three common sources: perceivability, bias, and simi-\ud larity. However, simultaneous estimates of these values have rarely (if ever) been performed. We present the\ud results of two new experiments which allow for the simultaneous estimation of these factors, and examine\ud how the shape of a visual mask impacts each of them, as inferred through a new statistical model. Results showed that the shape and identity of the mask impacted the inferred perceivability, bias, and similarity space of a letter set, but that there were aspects of similarity that were robust to the choice of mask. The results illustrate how the psychological concepts of perceivability, bias, and similarity can be estimated simultaneously, and how each make powerful contributions to visual letter identification

    Reproducibility of the NEPTUNE descriptor-based scoring system on whole-slide images and histologic and ultrastructural digital images

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    The multicenter Nephrotic Syndrome Study Network (NEPTUNE) digital pathology scoring system employs a novel and comprehensive methodology to document pathologic features from whole-slide images, immunofluorescence and ultrastructural digital images. To estimate inter- and intra-reader concordance of this descriptor-based approach, data from 12 pathologists (eight NEPTUNE and four non-NEPTUNE) with experience from training to 30 years were collected. A descriptor reference manual was generated and a webinar-based protocol for consensus/cross-training implemented. Intra-reader concordance for 51 glomerular descriptors was evaluated on jpeg images by seven NEPTUNE pathologists scoring 131 glomeruli three times (Tests I, II, and III), each test following a consensus webinar review. Inter-reader concordance of glomerular descriptors was evaluated in 315 glomeruli by all pathologists; interstitial fibrosis and tubular atrophy (244 cases, whole-slide images) and four ultrastructural podocyte descriptors (178 cases, jpeg images) were evaluated once by six and five pathologists, respectively. Cohen’s kappa for inter-reader concordance for 48/51 glomerular descriptors with sufficient observations was moderate (0.40<kappa ≤0.60) for 17 and good (0.60<kappa ≤0.80) for 8, for 52% with moderate or better kappas. Clustering of glomerular descriptors based on similar pathologic features improved concordance. Concordance was independent of years of experience, and increased with webinar cross-training. Excellent concordance was achieved for interstitial fibrosis and tubular atrophy. Moderate-to-excellent concordance was achieved for all ultrastructural podocyte descriptors, with good-to-excellent concordance for descriptors commonly used in clinical practice, foot process effacement, and microvillous transformation. NEPTUNE digital pathology scoring system enables novel morphologic profiling of renal structures. For all histologic and ultrastructural descriptors tested with sufficient observations, moderate-to-excellent concordance was seen for 31/54 (57%). Descriptors not sufficiently represented will require further testing. This study proffers the NEPTUNE digital pathology scoring system as a model for standardization of renal biopsy interpretation extendable outside the NEPTUNE consortium, enabling international collaborations

    The Role of Perceived University Support in the Formation of Students' Entrepreneurial Intention

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    Entrepreneurship education is central to student entrepreneurship. Previous research has attempted to understand the role of entrepreneurship education in the formation of students' entrepreneurial intention and behavior, albeit in an isolated manner. Universities can support entrepreneurship in many ways, but it is important to measure students' perception of the support that they receive in order to understand the extent of such support and its impact on students. The current study proposed and tested an integrative, multiperspective framework. We have hypothesized that the three dimensions of university support, that is, perceived educational support, concept development support, and business development support, together with institutional support, shape students' entrepreneurial self-efficacy. In turn, entrepreneurial self-efficacy and individual motivations constitute the fundamental elements of the intention to start a business. A sample of 805 university students took part in the study and data were analyzed using structural equation modeling. Our findings showed that perceived educational support exerted the highest influence on entrepreneurial self-efficacy, followed by concept development support, business development support, and institutional support. Self-efficacy in turn had a significant effect on entrepreneurial intention. Individual motivations such as self-realization, recognition, and role had an additional impact on intention. However, intention was not related to financial success, innovation, and independence. The findings suggest that a holistic perspective provides a more meaningful understanding of the role of perceived university support in the formation of students' entrepreneurial intention. Theoretical and practical implications are discussed

    A whole-cell biosensor for the detection of gold

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    Geochemical exploration for gold (Au) is becoming increasingly important to the mining industry. Current processes for Au analyses require sampling materials to be taken from often remote localities. Samples are then transported to a laboratory equipped with suitable analytical facilities, such as Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) or Instrumental Neutron Activation Analysis (INAA). Determining the concentration of Au in samples may take several weeks, leading to long delays in exploration campaigns. Hence, a method for the on-site analysis of Au, such as a biosensor, will greatly benefit the exploration industry. The golTSB genes from Salmonella enterica serovar typhimurium are selectively induced by Au(I/III)-complexes. In the present study, the golTSB operon with a reporter gene, lacZ, was introduced into Escherichia coli. The induction of golTSB::lacZ with Au(I/III)-complexes was tested using a colorimetric β-galactosidase and an electrochemical assay. Measurements of the β-galactosidase activity for concentrations of both Au(I)- and Au(III)-complexes ranging from 0.1 to 5 µM (equivalent to 20 to 1000 ng g⁻¹ or parts-per-billion (ppb)) were accurately quantified. When testing the ability of the biosensor to detect Au(I/III)-complexes(aq) in the presence of other metal ions (Ag(I), Cu(II), Fe(III), Ni(II), Co(II), Zn, As(III), Pb(II), Sb(III) or Bi(III)), cross-reactivity was observed, i.e. the amount of Au measured was either under- or over-estimated. To assess if the biosensor would work with natural samples, soils with different physiochemical properties were spiked with Au-complexes. Subsequently, a selective extraction using 1 M thiosulfate was applied to extract the Au. The results showed that Au could be measured in these extracts with the same accuracy as ICP-MS (P<0.05). This demonstrates that by combining selective extraction with the biosensor system the concentration of Au can be accurately measured, down to a quantification limit of 20 ppb (0.1 µM) and a detection limit of 2 ppb (0.01 µM).Carla M. Zammit, Davide Quaranta, Shane Gibson, Anita J. Zaitouna, Christine Ta, Joël Brugger, Rebecca Y. Lai, Gregor Grass, Frank Reit

    Quality of life and psychosocial wellbeing in youth with neuromuscular disorders who are wheelchair Users: A systematic review

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    Objective: To investigate quality of life (QoL) and psychosocial wellbeing in youth with Neuromuscular Disorders (NMD) who are wheelchair users. Data Sources: Medline, Embase, CINAHL and PsycINFO (January 2004 to April 2016) and reference lists of retrieved full-text papers. Study Selection: Peer-reviewed studies were included when data describing self-reported QoL and psychosocial wellbeing could be separately understood for those using wheelchairs and aged 12-22 years old. 2058 records were independently screened and potentially eligible papers were obtained and examined by all reviewers. Twelve observational and three qualitative studies met the inclusion criteria. Data Extraction: Population representativeness, measurement tools and outcomes, where possible with comparison groups. Two reviewers independently appraised studies for risk of bias to internal validity and generalisability. Data Synthesis: Heterogeneity of measurement and reporting precluded meta-analysis. Data were cross-sectional only. Compared to same age typically developing peers, physical QoL was scored consistently and significantly lower in youth with NMD, whilst psychosocial QoL was not. Psychosocial QoL was highest in youth non-ambulant since early childhood and in those recruited via single tertiary specialist clinics. Mental health and social participation could not be compared to same age populations. Conclusions: Despite low physical QoL, psychosocial QoL in youth with NMD appeared comparable to same age peers. The psychosocial wellbeing of younger adolescents on degenerative disease trajectories appeared most compromised, though the longitudinal impacts of growing up with NMD on mental health and social participation are unknown. Interpretation was hampered by poor description of participant age, gender and physical ability, lack of population based recruitment strategies and inconsistent use of age appropriate measures. Understanding of self-reported QoL and psychosocial wellbeing in youth with NMD transitioning to adulthood is limited

    Corporate Entrepreneurship:From Structures to Mindset

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    Corporate entrepreneurship dispersed throughout an organization and leveraging the entrepreneurial potential of all its employees bears significant benefits for those organizations that embrace it. However, it appears more difficult to instill and requires strong investment in the development of human capital and entrepreneurial mindset among the employees and across the organization. In this chapter, we discuss the essence of corporate entrepreneurship mindset and show that across an organization, there might be different entrepreneurial mindsets that correspond to different people, opportunities, and contexts. Although different, they all lead to enactment of entrepreneurial projects. This chapter, thus, contributes to the discussion regarding the nature of corporate entrepreneurial mindsets, and their development and stimulation within an organization, from both academic and practical view
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