139 research outputs found

    A global model for the estimation of transport costs

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    This paper presents a model of transport cost determinants that corrects the specification problems observed in the transport cost equations in previous literature. The model includes freight transport supply and demand, as well as infrastructure quality and non-time-varying fixed effects related to the route, the exporting company, its strategy and the product. In addition, when defining the origin-destination routes, the model more appropriately accounts for economies of network and economies of scale. In order to build the database, 583 personal interviews were conducted over the course of 2011 with producing companies that ship goods and with the logistics operators. As a result, 305 routes between the Valencian Community and Europe were identified, from which 6390 observations were obtained. The results show that distance is a determining factor in the cost of transport, notwithstanding the infrastructure coverage and improvements in quality. At the same time, the analysis confirms that transport cost is more sensitive to the degree of competition on the route, the volume of freight on the route and the volume of goods shipped on the route by the exporting company, the configuration of the supply chain, the company strategy and the coverage and quality of transport infrastructure

    Técnicas BIM aplicadas a la reconstrucción virtual del yacimiento arqueológico Mleiha 5 (E.A.U.)

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    El objetivo del siguiente Proyecto Fin de Carrera consiste en definir y describir de forma ordenada, clara y precisa el procedimiento a seguir en el desarrollo de un trabajo mediante técnicas BIM (Building Information Modeling - Modelado de Información de Construcción)con la finalidad añadida de que pueda servir como un protocolo general para los profesionales relacionados con el ámbito de estas materias. Este proyecto se ocupará de las siguientes tareas: 1.-Terminología, normativa, ámbitos de aplicación, metodología y flujo de trabajo empleados en la utilización de técnicas denominadas BIM. 2.- Aplicación sobre el yacimiento arqueológico Mleiha zona 5 situado en Emiratos Árabes Unidos, incluyendo la elaboración de un modelo de reconstrucción virtual de este cementerio y sus antiguos panteones. Para ello contaremos con la topografía y cartografía de la zona, en una superficie aproximada de 1 Hectárea, procedente de un levantamiento a escala 1:200 realizado en Mayo de 2013

    Family firm heterogeneity and tax aggressiveness: A quasi-experimental analysis of the impact of different family generations

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    This paper analyses tax aggressiveness in family firm generations. Moreover, taking into account the heterogeneity in family firms, we check whether the successive generations in control show different tax avoidance behaviour. The empirical evidence, based on the quasi-experiment of the 2012 Spanish thin capitalization rule, reveals that there is a positive relationship between tax aggressiveness and successive generations. Moreover, the founder and second generations follow a similar conservative tax avoidance approach, whereas the third and fourth generations are found to be more tax aggressive

    La agricultura española durante la Segunda República : análisis socio-económico e incidencias de la misma en el estallido de la Guerra civil

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    Tesis Universidad Complutense de Madrid, 1983.Fac. de Ciencias Políticas y SociologíaTRUEProQuestpu

    Effect of transnasal insufflation on sleep disordered breathing in acute stroke: a preliminary study

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    Background and Purpose: Sleep disordered breathing (SDB) is frequent in acute stroke patients and is associated with early neurologic worsening and poor outcome. Although continuous positive airway pressure (CPAP) effectively treats SDB, compliance is low. The objective of the present study was to assess the tolerance and the efficacy of a continuous high-flow-rate air administered through an open nasal cannula (transnasal insufflation, TNI), a less-intrusive method, to treat SDB in acute stroke patients. Methods: Ten patients (age, 56.8 ± 10.7years), with SDB ranging from moderate to severe (apnea-hypopnea index, AHI, >15/h of sleep) and on a standard sleep study at a mean of 4.8 ± 3.7days after ischemic stroke (range, 1-15days), were selected. The night after, they underwent a second sleep study while receiving TNI (18L/min). Results: TNI was well tolerated by all patients. For the entire group, TNI decreased the AHI from 40.4 ± 25.7 to 30.8 ± 25.7/h (p = 0.001) and the oxygen desaturation index >3% from 40.7 ± 28.4 to 31 ± 22.5/h (p = 0.02). All participants except one showed a decrease in AHI. The percentage of slow-wave sleep significantly increased with TNI from 16.7 ± 8.2% to 22.3 ± 7.4% (p = 0.01). There was also a trend toward a reduction in markers of sleep disruption (number of awakenings, arousal index). Conclusions: TNI improves SDB indices, and possibly sleep parameters, in stroke patients. Although these changes are modest, our findings suggest that TNI is a viable treatment alternative to CPAP in patients with SDB in the acute phase of ischemic strok

    Light Kaluza-Klein States in Randall-Sundrum Models with Custodial SU(2)

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    We consider Randall-Sundrum scenarios based on SU(2)_L x SU(2)_R and a discrete parity exchanging L with R. The custodial and parity symmetries can be used to make the tree level contribution to the T parameter and the anomalous couplings of the bottom quark to the Z very small. We show that the resulting quantum numbers typically induce a negative T parameter at one loop that, together with the positive value of the S parameter, restrict considerably these models. There are nevertheless regions of parameter space that successfully reproduce the fit to electroweak precision observables with light Kaluza-Klein excitations accessible at colliders. We consider models of gauge-Higgs unification that implement the custodial and parity symmetries and find that the EW data singles out a very well defined region in parameter space. In this region one typically finds light gauge boson Kaluza-Klein excitations as well as light SU(2)_L singlet, and sometimes also doublet, fermionic states, that mix with the top quark, and may yield interesting signatures at future colliders.Comment: 35 pages, 7 figure

    The effect of continuous positive airway pressure on total cerebral blood flow in healthy awake volunteers

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    Purpose: Continuous positive airway pressure (CPAP) is the gold standard treatment for obstructive sleep apnea. However, the physiologic impact of CPAP on cerebral blood flow (CBF) is not well established. Ultrasound can be used to estimate CBF, but there is no widespread accepted protocol. We studied the physiologic influence of CPAP on CBF using a method integrating arterial diameter and flow velocity (FV) measurements obtained for each vessel supplying blood to the brain. Methods: FV and lumen diameter of the left and right internal carotid, vertebral, and middle cerebral arteries were measured using duplex Doppler ultrasound with and without CPAP at 15cmH2O, applied in a random order. Transcutaneous carbon dioxide (PtcCO2), heart rate (HR), blood pressure (BP), and oxygen saturation were monitored. Results were compared with a theoretical prediction of CBF change based on the effect of partial pressure of carbon dioxide on CBF. Results: Data were obtained from 23 healthy volunteers (mean ± SD; 12 male, age 25.1 ± 2.6years, body mass index 21.8 ± 2.0kg/m2). The mean experimental and theoretical CBF decrease under CPAP was 12.5% (p < 0.001) and 11.9% (p < 0.001), respectively. The difference between experimental and theoretical CBF reduction was not statistically significant (3.84 ± 79ml/min, p = 0.40). There was a significant reduction in PtcCO2 with CPAP (p = <0.001) and a significant increase in mean BP (p = 0.0017). No significant change was observed in SaO2 (p = 0.21) and HR (p = 0.62). Conclusion: Duplex Doppler ultrasound measurements of arterial diameter and FV allow for a noninvasive bedside estimation of CBF. CPAP at 15cmH2O significantly decreased CBF in healthy awake volunteers. This effect appeared to be mediated predominately through the hypocapnic vasoconstriction coinciding with PCO2 level reduction. The results suggest that CPAP should be used cautiously in patients with unstable cerebral hemodynamic

    Hormone Targets for the Treatment of Sleep Disorders in Postmenopausal Women with Schizophrenia: A Narrative Review

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    While the early identification of insomnia in patients with schizophrenia is of clinical relevance, the use of specific compounds to treat insomnia has been studied less in postmenopausal women with schizophrenia. We aimed to explore the effects of melatonin, sex hormones, and raloxifene for the treatment of insomnia in these populations. Although melatonin treatment improved the quality and efficiency of the sleep of patients with schizophrenia, few studies have explored its use in postmenopausal women with schizophrenia. The estrogen and progesterone pathways are dysregulated in major psychiatric disorders, such as in schizophrenia. While, in the context of menopause, a high testosterone-to-estradiol ratio is associated with higher frequencies of depressive symptoms, the effects of estradiol and other sex hormones on sleep disorders in postmenopausal women with schizophrenia has not been sufficiently investigated. Raloxifene, a selective estrogen receptor modulator, has shown positive effects on sleep disorders in postmenopausal women. Future studies should investigate the effectiveness of hormonal compounds on insomnia in postmenopausal women with schizophrenia

    Draft Genome Sequence of the Moderately Halophilic Bacterium Pseudoalteromonas ruthenica Strain CP76

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    Pseudoalteromonas ruthenica strain CP76, isolated from a saltern in Spain, is a moderately halophilic bacterium belonging to the Gammaproteobacteria. Here we report the draft genome sequence, which consists of a 4.0-Mb chromosome, of this strain, which is able to produce the extracellular enzyme haloprotease CPI
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