22,479 research outputs found

    Intra-Firm Human Capital Externalities in Tunisia

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    In this case-study, we use matched worker-firm Tunisian data to elicit the roles of intra-firm human capital and modern firm features in worker remunerations. We show that the estimated return to education in wage equations is not modified when replacing in the list of regressors the firm dummies, representing observed and unobserved firm heterogeneity, by the first three factors of a Principal Component Analysis of the observed firm characteristics. These factors can be interpreted as: the activity sector, the intra-firm human capital density and the modernity of the firm. These results constitute an interesting argument in favour of the presence of intra-firm human capital externalities. Moreover, the estimated education coefficient does not change when the three factors are replaced by three surrogate variables, respectively: the textile industry dummy, the intra-firm mean education, and the firm’s age.economic development, rate of returns, human capital, wage differentials, intra-firm knowledge externalities, Tunisia.

    Designing Game Audio Based on Avatar-Centred Subjectivity

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    This chapter explores a selection of practical approaches for designing video game audio based on the subjective perception of a player avatar. The authors discuss several prototype video game systems developed as part of their practice-led research, which provide interactive audio systems that represent the aural experience of a virtual avatar undergoing an altered state of consciousness. Through the discussion of these prototypes, the authors expose a variety of possible approaches for sound design in order to represent the subjective perceptual experiences of a player avatar

    Simulating Auditory Hallucinations in a Video Game: Three Prototype Mechanisms

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    In previous work the authors have proposed the concept of 'ASC Simulation1: including audio-visual installations and experiences, as well as interactive video game systems, which simulate altered states of consciousness (ASCs) such as dreams and hallucinations. Building on the discussion of the authors' previous paper, where a large-scale qualitative study explored the changes to auditory perception that users of various intoxicating substances report, here the authors present three prototype audio mechanisms for simulating hallucinations in a video game. These were designed in the Unity video game engine as an early proof-of-concept. The first mechanism simulates 'selective auditory attention' to different sound sources, by attenuating the amplitude of unattended sources. The second simulates 'enhanced sounds', by adjusting perceived brightness through filtering. The third simulates 'spatial disruptions' to perception, by dislocating sound sources from their virtual acoustic origin in 3D-space, causing them to move in oscillations around a central location. In terms of programming structure, these mechanisms are designed using scripts that are attached to the collection of assets that make up the player character, and in future developments of this type of work we foresee a more advanced, standardised interface that models the senses, emotions and state of consciousness of player avatars

    In-Game Intoxication: Demonstrating the Evaluation of the Audio Experience of Games with a Focus on Altered States of Consciousness

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    In this chapter, we consider a particular method of specifically evaluating the user experience of game audio. To provide a domain of game audio to evaluate, we focus on an increasingly occuring phenomenon in game; that of the altered state of consciousness. Our approach seeks to evaluate user experience of game audio from normal gameplay and gameplay that features altered states. As such, a brief background to person-centered approaches to use experience evaluation is presented and then we provide a detailed description of the method that has been adopted in this chapter: the use of personal construct theory via repertory grid interviews

    Determination of Permittivity of Dielectric Analytes in the Terahertz Frequency Range Using Split Ring Resonator Elements Integrated with On-Chip Waveguide

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    We investigate the use of finite-element simulations as a novel method for determining the dielectric property of target materials in the terahertz (THz) frequency range using split-ring resonator (SRR) sensing elements integrated into a planar Goubau line (PGL) waveguide. Five such SRRs were designed to support resonances at specific target frequencies. The origin of resonance modes was identified by investigating the electric field distribution and surface current modes in each SRR. Red-shifts were found in the resonances upon deposition of overlaid test dielectric layers that saturated for thicknesses above 10 µm. We also confirmed that the SRRs can work as independent sensors by depositing the analyte onto each individually. The relation between the permittivity of the target material and the saturated resonant frequency was obtained in each case, and was used to extract the permittivity of a test dielectric layer at six different frequencies in the range of 200–700 GHz as an example application. Our approach enables the permittivity of small volumes of analytes to be determined at a series of discrete frequencies up to ~1 THz

    Effect of Substrate Etching on Terahertz Metamaterial Resonances and Its Liquid Sensing Applications

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    We investigate the effect of substrate etching on terahertz frequency range metamaterials using finite-element method simulations. A blue shift was found in the metamaterial resonance with increasing substrate etch depth, caused by a decrease in the effective refractive index. The relative contribution of the substrate’s refractive index to the effective refractive index was obtained as a function of the etch depth, finding that the decay length of the electric field magnitude below the LC gap is larger for the etched metamaterials due to their lower effective refractive index. We suggest designs for a terahertz metamaterial liquid sensor utilizing substrate etching which shows a significant enhancement in sensitivity compared to unetched sensors using ethanol as an example analyte. The sensitivity of the liquid sensor was enhanced by up to ~6.7-fold, from 76.4 to 514.5 GHz/RIU, for an ethanol liquid layer with a thickness of 60 μm by the incorporation of a substrate etch depth of 30 µm. Since the region of space close to the metamaterial is the most sensitive, however, we find that for small liquid thicknesses, larger etch depths can act to decrease sensitivity, and provide quantitative estimates of this effect

    Evaluation of a Phosphate Management Protocol to Achieve Optimum Serum Phosphate Levels in Hemodialysis Patients

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    Original article can be found at: http://www.sciencedirect.com/science/journal/10512276 Copyright National Kidney Foundation, Inc. DOI: 10.1053/j.jrn.2008.05.003To evaluate the effectiveness of a protocol designed to optimize serum phosphate levels in patients undergoing regular hemodialysis (HD).Peer reviewe

    Chromosome 9p deletion in clear cell renal cell carcinoma predicts recurrence and survival following surgery

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    BACKGROUND: Wider clinical applications of 9p status in clear cell renal cell carcinoma (ccRCC) are limited owing to the lack of validation and consensus for interphase fluorescent in situ hybridisation (I-FISH) scoring technique. The aim of this study was to analytically validate the applicability of I-FISH in assessing 9p deletion in ccRCC and to clinically assess its long-term prognostic impact following surgical excision of ccRCC. METHODS: Tissue microarrays were constructed from 108 renal cell carcinoma (RCC) tumour paraffin blocks. Interphase fluorescent in situ hybridisation analysis was undertaken based on preset criteria by two independent observers to assess interobserver variability. 9p status in ccRCC tumours was determined and correlated to clinicopathological variables, recurrence-free survival and disease-specific survival. RESULTS: There were 80 ccRCCs with valid 9p scoring and a median follow-up of 95 months. Kappa statistic for interobserver variability was 0.71 (good agreement). 9p deletion was detected in 44% of ccRCCs. 9p loss was associated with higher stage, larger tumours, necrosis, microvascular and renal vein invasion, and higher SSIGN (stage, size, grade and necrosis) score. Patients with 9p-deleted ccRCC were at a higher risk of recurrence (P=0.008) and RCC-specific mortality (P=0.001). On multivariate analysis, 9p deletion was an independent predictor of recurrence (hazard ratio 4.323; P=0.021) and RCC-specific mortality (hazard ratio 4.603; P=0.007). The predictive accuracy of SSIGN score improved from 87.7% to 93.1% by integrating 9p status to the model (P=0.001). CONCLUSIONS: Loss of 9p is associated with aggressive ccRCC and worse prognosis in patients following surgery. Our findings independently confirm the findings of previous reports relying on I-FISH to detect 9p (CDKN2A) deletion
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