5,483 research outputs found

    Wage differentials across economic sectors in the Colombian formal labour market: evidence from a survey of firms

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    The existence of wage differentials across sectors is a widely observed phenomenon. This paper provides new elements to understand inter and intra-sectoral wage differentials in Colombia by analysing a wage setting survey of 1305 firms and emphasizing the role of firm characteristics. The results from the descriptive analysis of the survey confirm the existence of substantial wage differentials across sectors and occupational positions in the country. We found positive wage differentials, with respect to the average of the economy for the different occupational groups, in electricity, gas, water and mining, financial services and manufacturing and strong negative wage differentials in agriculture, forestry and fishing. When analysing wage differential within each occupational group, higher wage dispersion is observed in the case of managers, followed by professionals. The lower wage dispersion for the least qualified jobs could be associated with the existence of a minimum wage in the country. In addition, we estimate cross section models for each occupational group and sector to account for the importance of firm characteristics in explaining wage differentials.Wage differentials, survey of firms, labour market, cross section estimation. Classification JEL: J30, J31, C21

    Influence of SiO2, TiO2 and Fe2O3 nanoparticles on the properties of fly ash blended cement mortars

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    This study explores the effects of different types of nanoparticles, namely nano-SiO2 (NS), nano-TiO2 (NT), and nano-Fe2O3 (NF) on the fresh properties, mechanical properties, and microstructure of cement mortar containing fly ash as a supplementary cementitious material. These nanoparticles existed in powder form and were incorporated into the mortar at the dosages of 1%, 3%, and 5% wt.% of cement. Also, fly ash has been added into in mortars with a constant dosage of 30% wt.% of cement. Compressive and flexural strength tests were performed to evaluate the mechanical properties of the mortar specimens with different nanoparticles at three curing ages, 7, 14, and 28 days. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) tests were conducted to study the microstructure and the hydration products of the mortars. To elucidate the effects of nanoparticles on the binder phase, additional experiments were performed on accompanying cement pastes: nanoindentation and open porosity measurements. The study shows that, if added in appropriate amounts, all nanoparticles investigated can result in significantly improved mechanical properties compared to the reference materials. However, exceeding of the optimal concentration results in clustering of the nanoparticles and reduces the mechanical properties of the composites, which is accompanied with increasing the porosity. This study provides guidelines for further improvement of concretes with blended cements through use of nanoparticles

    Can Clinical and Surgical Parameters Be Combined to Predict How Long It Will Take a Tibia Fracture to Heal? A Prospective Multicentre Observational Study: The FRACTING Study

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    Healing of tibia fractures occurs over a wide time range of months, with a number of risk factors contributing to prolonged healing. In this prospective, multicentre, observational study, we investigated the capability of FRACTING (tibia FRACTure prediction healING days) score, calculated soon after tibia fracture treatment, to predict healing time. Methods: The study included 363 patients. Information on patient health, fracture morphology, and surgical treatment adopted were combined to calculate the FRACTING score. Fractures were considered healed when the patient was able to fully weight-bear without pain. Results: 319 fractures (88%) healed within 12 months from treatment. Forty-four fractures healed after 12 months or underwent a second surgery. FRACTING score positively correlated with days to healing: r = 0.63 (p < 0.0001). Average score value was 7.3 ± 2.5; ROC analysis showed strong reliability of the score in separating patients healing before versus after 6 months: AUC = 0.823. Conclusions: This study shows that the FRACTING score can be employed both to predict months needed for fracture healing and to identify immediately after treatment patients at risk of prolonged healing. In patients with high score values, new pharmacological and nonpharmacological treatments to enhance osteogenesis could be tested selectively, which may finally result in reduced disability time and health cost savings

    Graying Incarcerated Persons and Education Programs in Nigerian Correctional Centre

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    Correctional education programs are rehabilitation programs designed for incarcerated persons in Nigerian correctional institutions. However, getting the graying incarcerated persons to participate in education programs becomes quite challenging. This study investigates graying incarcerated persons and education programs in one correctional centre. Data were collected qualitatively from fifteen (15) incarcerated individuals aged 60 years and above using semi-structured interviews. Thematic analysis was employed in analyzing the data generated for the study. Findings show that there are no available education programs for graying incarcerated individuals. The study also revealed that designing education programs in such a way that it will accommodate the needs of the graying population will alleviate or soothe this category of prisoners. The study, therefore, recommends that education programs should be inclusive of different populations of incarcerated persons, especially the graying ones. Social workers have roles to play in alleviating the problems faced by graying incarcerated persons

    An inhomogeneous and anisotropic constitutive model of human dentin

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    Dentin constitutes the major part of human tooth. It is composed of a large number of tubules with both variational radii and radially parallel pattern. In addition, peritubular dentin surrounds each tubule lumen and has a higher elastic modulus than the matrix of dentin, i.e. intertubular dentin. Considering the above microstructural characteristics, a micromechanics model is used in this paper to evaluate the overall elastic properties of dentin. Five independent effective elastic parameters in transverse isotropic elasticity matrix can be expressed analytically by the material parameters of peri- and intertubular dentin and the volume fraction of tubules. To determine the effectivity of this theoretical model, a finite element (FE) model simulating a longitudinal tooth slice in moir!e fringe testing of Wang and Weiner (J. Biomech. 31 (1998) 135) was performed. Furthermore, the FE model was developed incorporate modeling of variation of tubule’s diameter and softer characteristic of intertubular dentin near the dentin–enamel junction and around the pulp chamber. It turned out that the isoline figure of longitudinal displacement by FE calculation has very similar patterns to the moir!e fringe results. However, the FE results of displacement by traditional stress–strain models which regard dentin as a homogeneous and isotropic material show an obviously different strain distributions as compared to published moir!e fringes results. Thus the inhomogeneous and anisotropic model developed in this paper more accurately reflects the true physical nature of human dentin

    First application of Markov chain Monte Carlo-based Bayesian data analysis to the Doppler-shift attenuation method

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    Motivated primarily by the large uncertainties in the thermonuclear rate of the 30P(p,γ)31S reaction that limit our understanding of classical novae, we carried out lifetime measurements of 31S excited states using the Doppler Shift Lifetimes (DSL2) facility at the TRIUMF Isotope Separator and Accelerator (ISAC-II) facility. The 31S excited states were populated by the 3He(32S,α)31S reaction. The deexcitation γ rays were detected by a clover-type high-purity germanium detector in coincidence with the α particles detected by a silicon detector telescope. We have applied modern Markov chain Monte Carlo-based Bayesian statistical techniques to perform lineshape analyses of Doppler-shift attenuation method γ-ray data for the first time. We have determined the lifetimes of the two lowest-lying 31S excited states. First experimental upper limits on the lifetimes of four higher-lying states have been obtained. The experimental results were compared to shell-model calculations using five universal sd-shell Hamiltonians. Evidence for γ rays originating from the astrophysically important Jπ=3/2+, 260-keV 30P(p,γ)31S resonance with an excitation energy of Ex=6390.2(7) keV in 31S has also been observed, although strong constraints on the lifetime will require better statistics
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