1,799 research outputs found

    Occupations at risk and organizational well-being: an empirical test of a Job Insecurity Integrated Model

    Get PDF
    One of the more visible effects of the societal changes is the increased feelings of uncertainty in the workforce. In fact, job insecurity represents a crucial occupational risk factor and a major job stressor that has negative consequences on both organizational well-being and individual health. Many studies have focused on the consequences about the fear and the perception of losing the job as a whole (called quantitative job insecurity), while more recently research has begun to examine more extensively the worries and the perceptions of losing valued job features (called qualitative job insecurity). The vast majority of the studies, however, have investigated the effects of quantitative and qualitative job insecurity separately. In this paper, we proposed the Job Insecurity Integrated Model aimed to examine the effects of quantitative job insecurity and qualitative job insecurity on their short-term and long-term outcomes. This model was empirically tested in two independent studies, hypothesizing that qualitative job insecurity mediated the effects of quantitative job insecurity on different outcomes, such as work engagement and organizational identification (Study 1), and job satisfaction, commitment, psychological stress and turnover intention (Study 2). Study 1 was conducted on 329 employees in private firms, while Study 2 on 278 employees in both public sector and private firms. Results robustly showed that qualitative job insecurity totally mediated the effects of quantitative on all the considered outcomes. By showing that the effects of quantitative job insecurity on its outcomes passed through qualitative job insecurity, the Job Insecurity Integrated Model contributes to clarifying previous findings in job insecurity research and puts forward a framework that could profitably produce new investigations with important theoretical and practical implications

    Audio Features Affected by Music Expressiveness

    Full text link
    Within a Music Information Retrieval perspective, the goal of the study presented here is to investigate the impact on sound features of the musician's affective intention, namely when trying to intentionally convey emotional contents via expressiveness. A preliminary experiment has been performed involving 1010 tuba players. The recordings have been analysed by extracting a variety of features, which have been subsequently evaluated by combining both classic and machine learning statistical techniques. Results are reported and discussed.Comment: Submitted to ACM SIGIR Conference on Research and Development in Information Retrieval (SIGIR 2016), Pisa, Italy, July 17-21, 201

    Young australian adults’ reactions to viewing personalised uv photoaged photographs

    Get PDF
    Background: Despite two nationwide sun-protection awareness campaigns, young Australian adults continue to sunbathe. Since their primary motivation for tanning is appearance enhancement, it may well be that campaigns that highlight the negative effects of tanning on appearance are more effective than campaigns that emphasise the health risks associated with sun exposure.Aims: This study aims to explore young adults’ reactions to viewing a photoaged photograph of the sun damage already visible in their facial image.Methods: Semi-structured interviews were conducted with seven females and three males aged 20-30 years. The interview transcripts were transcribed verbatim and were then subjected to Interpretive Phenomenological Analysis (IPA).Results: Three themes and eight sub-themes emerged from the analysis. Collectively they revealed that participants’ fear-based reaction to their photoaged photographs triggered in them feelings of unattractiveness, which in turn motivated them to change to their existing sun-tanning behaviours.Conclusion: Although media-popularised representations of suntanned skin being the desired norm were identified as a barrier to skin-protective behavioural change, personalised ultraviolet (UV) photoaged photographs, when accompanied by an explanation of the skin damage that unprotected ultraviolet radiation (UVR) exposure causes, were effective in changing young adults’ sun-tanning intentions. Hence, a need exists for positive non-tanning appearance-related messages to be incorporated into sun exposure education campaigns

    A quantum measurement of the spin direction

    Get PDF
    We give a first physical model for the quantum measurement of the spin direction. It is an Arthurs-Kelly model that involves a kind of magnetic-dipole interaction of the spin with three modes of radiation. We show that in a limit of infinite squeezing of radiation the optimal POVM for the measurement of the spin direction is achieved for spin 1/2

    Augmented GNSS Differential Corrections Minimum Mean Square Error Estimation Sensitivity to Spatial Correlation Modeling Errors

    Get PDF
    Railway signaling is a safety system that has evolved over the last couple of centuries towards autonomous functionality. Recently, great effort is being devoted inthis ïŹeld, towards the use and exploitation of Global Navigation Satellite System (GNSS)signals and GNSS augmentation systems in view of lower railway track equipments andmaintenance costs, that is a priority to sustain the investments for modernizing the local andregional lines most of which lack automatic train protection systems and are still manuallyoperated. The objective of this paper is to assess the sensitivity of the Linear Minimum MeanSquare Error (LMMSE) algorithm to modeling errors in the spatial correlation function thatcharacterizes true pseudorange Differential Corrections (DCs). This study is inspired bythe railway application; however, it applies to all transportation systems, including the roadsector, that need to be complemented by an augmentation system in order to deliver accurateand reliable positioning with integrity speciïŹcations. A vector of noisy pseudorange DCmeasurements are simulated, assuming a Gauss-Markov model with a decay rate parameterinversely proportional to the correlation distance that exists between two points of a certainenvironment. The LMMSE algorithm is applied on this vector to estimate the true DC, andthe estimation error is compared to the noise added during simulation. The results show thatfor large enough correlation distance to Reference Stations (RSs) distance separation ratiovalues, the LMMSE brings considerable advantage in terms of estimation error accuracy and precision. Conversely, the LMMSE algorithm may deteriorate the quality of the DCmeasurements whenever the ratio falls below a certain threshold

    Stability Analysis of the Serchio River Flood Plain Embankments (Tuscany, Italy)

    Get PDF
    Following the geotechnical characterization of 30 km long flood - plain embankments of the Serchio River (Tuscany – Italy), a number of numerical analyses have been carried out. The embankments have been constructed since the XVIII century and have experienced several failures in the years (the last in December 2009). The geotechnical characterization of the river embankments and the 2009 flood are described in a companion paper in this Conference. This paper shows the results of numerical analyses that have been carried out for various purposes. More specifically, the numerical analyses were carried out a) to clarify the causes of the December 2009 failures, b) to design appropriate repair of the failures and retrofit of the embankments in proximity of the failures (about 6 km) and c) to identify the most risk areas considering the whole extension of the embankments (30 km). The limit equilibrium method was used to assess the stability of the embankments under steady state flow conditions (areas close to the failures). For this analysis three different types of commercial software were used. The stability analyses were carried out using the Bishop simplified method with circular sliding surfaces. The different codes indicated very similar failure surfaces corresponding to the minimum (meaningful) values of the global safety factor. Some differences on the values of the global safety factor were observed by comparing the results obtained from the three codes. More specifically, the analyses results show that, for the selected cross sections, the safety factors are rather small and approaching to unity, if the seepage forces are not considered. In the case of steady state flow, safety factor drastically reduces becoming lower than one. This result apparently contradicts the fact that the considered embankments are standing up since centuries and failures occurred only in the occasion of floods. The FEM analysis (PLAXIS Flow) shows that the safety margins of the considered sections, in absence of filtration, are assigned to the partial saturation of the embankment. Unfortunately, an appropriate characterization of the material under conditions of partial saturation was not available. Therefore, the FEM analyses were also aimed at determining the necessary time to approach the steady state flow conditions. For the case under consideration it was estimated that 10 days are necessary to approach the steady state flow conditions. This time is apparently much longer than the duration of the longest flood event (few hours). From the above it is possible to conclude that the hypothesis of permanent flow is generally too cautious. Anyway for the failures under consideration, that have occurred with the concurrence of various adverse factors like the melting of the snow because of a sudden temperature increase and the contemporary long raining period (two consecutive floods), it is reasonable to assume that the permanent flow conditions were probably reached. In addition to the numerical analyses, evidences of the considered event and the susceptibility of the analyzed soil to piping phenomena have also been considered to find out all the possible causes and to design in an appropriate way both repair of the failures and retrofitting of the surrounding areas. Assessment of the most risky areas, considering the whole extension of the embankments (30 km), has been carried out following expeditious criteria which were based on the embankment geometry and the mechanical soil characteristics

    Geotechnical Characterization of the Flood Plain Embankments of the Serchio River (Tuscany, Italy)

    Get PDF
    The flood plain embankments of the Serchio river have been constructed since the XVIII century and construction details are not known. These embankments have experienced failures several times during their life (last in December 2009). After the last event a detailed geotechnical investigation has been carried out. This paper discusses the necessary criteria for a cost – effective campaign considering the total length of the embankments (30 km) and the requested level of detail. In fact levee failure, although it is of limited extension, causes the achievement of the ultimate limit state of the entire embankment system. The campaign, in addition to laboratory tests, included boreholes, CPTu, permeability tests, 2D geo-electric tomography and 15 tests performed by the use of the continuous core drilling system. This last has proved to be a very useful tool for obtaining the more accurate evaluation of the in situ soil density (as confirmed by CPTu results). CPTu test, economical and expeditious, has proved to be an indispensable tool for delineating soil stratigraphy. In fact, their results combined with the borehole logs and laboratory testing provide extensive information. Geo-electric investigations can be very useful to highlight anomalies and heterogeneities in the cross section. Eventually, it is worthwhile to stress that embankments have generally a height of less than 4 m and a width between 1.2 and 3 m. This has restricted the investigation tools that could be used in this peculiar case

    The role of blood clot in guided bone regeneration: Biological considerations and clinical applications with titanium foil

    Get PDF
    In Guided Bone Regeneration (GBR) materials and techniques are essential to achieve the expected results. Thanks to their properties, blood clots induce bone healing, maturation, differenti-ation and organization. The preferred material to protect the clot in Guided Bone Regeneration is the titanium foil, as it can be shaped according to the bone defect. Furthermore, its exposition in the oral cavity does not impair the procedure. We report on five clinical cases in order to explain the management of blood clots in combination with titanium foil barriers in different clinical settings. Besides being the best choice to protect the clot, the titanium foil represents an excellent barrier that is useful in GBR due to its biocompatibility, handling, and mechanical strength properties. The clot alone is the best natural scaffold to obtain the ideal bone quality and avoid the persistence of not-resorbed granules of filler materials in the newly regenerated bone. Even though clot contraction still needs to be improved, as it impacts the volume of the regenerated bone, future studies in GBR should be inspired by the clot and its fundamental properties

    Spatial extent of recent vertical tectonic motions misured in NE Sicily coastal area. Insights from marine geology and coastal geomorphology studies.

    Get PDF
    Vertical position of sea-level, pointed out by related deposits and morphologies, provide useful markers to estimate tectonic uplift rates. For the Holocene very high uplift rates are misured in the northeast Sicily coast (Antonioli et al., 2009). This study compare vertical tectonic movements and marine geology data in the coastal sector between Capo d\u2019Orlando and Brolo (NE Sicily); tectonic lineaments show different trends both onland (Nigro & Sulli, 1995) and offshore (Nicolich et al.,1982) and also the morphological response follow closely this difference. The geomorphologic survey provided data on Holocene uplift rates. We studied an archaeological ancient quarry of grinding wheels for oil that has been found in the Capo d\u2019Orlando inshore (Scicchitano et al., 2011). They present semi submerged circular holes in Stilo-Capo d\u2019Orlando deposits (Carbone et al., 1998). The tectonic uplift was evaluated as the difference between the observed local paleo-sea level position and the predicted sea-level curve for the same locality (Lambeck et al., 2011). The resulting uplift rates is 0.36 mm/yr (Scicchitano et al., 2011). In this area we studied also the Brolo stack. It is a metamorphic rocks emerging at 450 m from the coastline. The study led to discovery a fossils-bearing conglomerate in protected trays at 3.5 m a.s.l.. Radiocarbon analysis on a gastropod, gave us an age of 4965 years +-70 cal BP. If we compare this data with the predicted local sea level curves (Lambeck et al., 2011), we obtain an uplift rate about 1.5 mm/yr (Lo Presti et al., 2010), which is higher than that calculated in the study of archaeological rest. A detailed study of Brolo sector show us different morphological coastline position of Brolo plain. A picture of the year 1847 shows the coastline about 200 m landward. In Brolo coastal plain we have also found a Spondylus at -6 m b.s.l. We wait for the radiocarbon dating which allows us to have a new uplift rate data. The analysis of marine geology data (Multibeam) evidenced structures connected to different faults systems, such as the submarine canyons that are the continuation of river beds. Multibeam data evidenced also tilted NE-ward submerged surfaces, indicating existing structural movements, interesting only restricted areas. So, very different uplift rates in the Holocene in very close areas distant only about 10 kilometers: both 0.36 mm/yr (Scicchitano et al. 2011) and 1.5 mm/yr (Lo Presti et al. 2010), and morphobathymetric data (tilted surfaces), evidence the important role of active tectonic lineaments. Seismic reflection profiles support this assumption, showing the metamorphic basement strongly dissected by high-angle faults, which at place determines the occurrence of emergent rock bodies (e.g. the Brolo stack). All this suggesting the occurrence of \u201crestricted regions\u201d in the coastal-marine sector with different geological behavior as response to prominent tectonic releasing bands, determining their horizontal and vertical movements
    • 

    corecore