192 research outputs found

    International Taxation and Multinational Firm Location Decisions

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    Using a large international firm-level data set, we estimate separate effects of host and parent country taxation on the location decisions of multinational firms. Both types of taxation are estimated to have a negative impact on the location of new foreign subsidiaries. In fact, the impact of parent country taxation is estimated to be relatively large, possibly reflecting its international discriminatory nature. For the cross-section of multinational firms, we find that parent firms tend to be located in countries with a relatively low taxation of foreign-source income. Overall, our results show that parent-country taxation – despite the general possibility of deferral of taxation until income repatriation – is instrumental in shaping the structure of multinational enterprise.corporate taxation, dividend withholding taxation, location decisions

    Identification and quantification of pathogenic helminth eggs using a digital image system

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    AbstractA system was developed to identify and quantify up to seven species of helminth eggs (Ascaris lumbricoides -fertile and unfertile eggs-, Trichuris trichiura, Toxocara canis, Taenia saginata, Hymenolepis nana, Hymenolepis diminuta, and Schistosoma mansoni) in wastewater using different image processing tools and pattern recognition algorithms. The system was developed in three stages. Version one was used to explore the viability of the concept of identifying helminth eggs through an image processing system, while versions 2 and 3 were used to improve its efficiency. The system development was based on the analysis of different properties of helminth eggs in order to discriminate them from other objects in samples processed using the conventional United States Environmental Protection Agency (US EPA) technique to quantify helminth eggs. The system was tested, in its three stages, considering two parameters: specificity (capacity to discriminate between species of helminth eggs and other objects) and sensitivity (capacity to correctly classify and identify the different species of helminth eggs). The final version showed a specificity of 99% while the sensitivity varied between 80 and 90%, depending on the total suspended solids content of the wastewater samples. To achieve such values in samples with total suspended solids (TSS) above 150 mg/L, it is recommended to dilute the concentrated sediment just before taking the images under the microscope. The system allows the helminth eggs most commonly found in wastewater to be reliably and uniformly detected and quantified. In addition, it provides the total number of eggs as well as the individual number by species, and for Ascaris lumbricoides it differentiates whether or not the egg is fertile. The system only requires basically trained technicians to prepare the samples, as for visual identification there is no need for highly trained personnel. The time required to analyze each image is less than a minute. This system could be used in central analytical laboratories providing a remote analysis service

    Scoliosis induced by medullary damage: an experimental study in rabbits

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    To date, there have been no reports of experiments designed to induce scoliosis by direct damage of different areas of the spinal cord. In a series of rabbits with medullary damage, the authors attempted selectively to interrupt the pathways that mediate proprioceptive input. Unilateral lesion of the dorsal column and posterior horn of the spinal cord was performed using three different techniques: coagulation with laser, stereotaxic microcoagulation, and longitudinal electrocoagulation. Of 32 operated rabbits, 17 developed scoliosis, exhibiting clear pathologic damage of the spinal cord. Electrophysiologic study, including EMG and analysis of the tonic -- vibratory reflex, was performed on 10 rabbits with medullary damage (scoliotic and non-scoliotic) and 12 matched controls. The data suggest disturbance of the sensory afferences that control the postural tone and consequent muscular imbalance, expressed as reduced activity in the muscles of the convex side. This work supports the view that loss of proprioceptive neural impulses caused by medullary damage can induce scoliosi

    Transcriptional silencing of the Dickkopfs-3 (Dkk-3) gene by CpG hypermethylation in acute lymphoblastic leukaemia

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    Dkk-3 is a newly characterised mortalisation-related gene and an antagonist of the Wnt oncogenic signalling pathway whose expression is decreased in a variety of cancer cell lines, suggesting that the Dkk-3 gene, located at chromosome 11p15.1, functions as a tumour suppressor gene. Although 11p15 is a ‘hot spot’ for methylation in acute lymphoblastic leukaemia (ALL), the role of Dkk-3 abnormalities has never been evaluated in this disease. We analysed CpG island methylation of the Dkk-3 promoter in six ALL cell lines and 183 ALL patients. We observed Dkk-3 hypermethylation in all cell lines and in cells from 33% (60/183) of ALL patients. Moreover, Dkk-3 methylation was associated with decreased Dkk-3 mRNA expression and this expression was restored after exposure to the demethylating agent 5-AzaC. Clinical features did not differ between hypermethylated and unmethylated patients. Estimated disease-free survival (DFS) and overall survival at 10 and 11 years, respectively, were 49.8 and 45.6% for normal patients and 10.5 and 15.1% for hypermethylated patients (P¼0.001 and 0.09). Multivariate analysis demonstrated that Dkk-3 methylation was an independent prognostic factor predicting DFS (P¼0.0009). Our data suggest that Dkk-3 methylation occurs at an early stage in ALL pathogenesis and probably influences the clinical behaviour of the disease

    Langerhans cell histiocytosis in the maxillofacial area in adults : report of three cases

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    Langerhans cell histiocytosis (LCH) is a disease of unknown etiology, characterized by proliferation of pathological Langerhans cells within different organs. It mainly affects children, but adult cases also occur, with an incidence rate of one to two per million. The head and neck are affected in almost 90% of cases. Diagnosis is made by means of histopathological analysis, and imaging studies are necessary in order to determine extent of the disease. There are no controlled trials proposing an optimal treatment protocol for LCH. Prognosis in adults is generally good due to the slow evolution of the disease and its favourable response to treatment. In our report, we present three cases of LCH in patients aged 16, 24, and 28 years respectively, with primary manifestation in the maxillofacial area. A literature review was also conducted

    Promoter hypermethylation of cancer-related genes: a strong independent prognostic factor in acute lymphoblastic leukemia

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    Promoter hypermethylation plays an important role in the inactivation of cancerrelated genes. This abnormality occurs early in leukemogenesis and seems to be associated with poor prognosis in acute lymphoblastic leukemia (ALL). To determine the extent of hypermethylation in ALL, we analyzed the methylation status of the CDH1, p73, p16, p15, p57, NES-1, DKK-3, CDH13, p14, TMS-1, APAF-1, DAPK, PARKIN, LATS-1, and PTEN genes in 251 consecutive ALL patients.Atotal of 77.3% of samples had at least 1 gene methylated, whereas 35.9% of cases had 4 or more genes methylated. Clinical features and complete remission rate did not differ among patients without methylated genes, patients with 1 to 3 methylated genes (methylated group A), or patients with more than 3 methylated genes (methylated group B). Estimated disease-free survival (DFS) and overall survival (OS) at 11 years were 75.5% and 66.1%, respectively, for the nonmethylated group; 37.2% and 45.5% for methylated group A; and 9.4% and 7.8% for methylated group B (P < .0001 and P .0004, respectively). Multivariate analysis demonstrated that the methylation profile was an independent prognostic factor in predicting DFS (P < .0001) and OS (P .003). Our results suggest that the methylation profile may be a potential new biomarker of risk prediction in AL

    Promoter hypomethylation of the LINE-1 retrotransposable elements activates sense/antisense transcription and marks the progression of chronic myeloid leukemia

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    Aberrant genome-wide hypomethylation is thought to be related to tumorigenesis by promoting genomic instability. Since DNA methylation is considered an important mechanism for the silencingof retroelements, hypomethylation in human tumors may lead to their reactivation. However, the role of DNA hypomethylation in chronic myeloid leukemia (CML) remains to be elucidated. In this study, the methylation status of the LINE-1 (L1) retrotransposon promoter was analysed in CML samples from the chronicphase (CP, n¼140) and the blast crisis (BC, n¼47). L1 hypomethylation was significantly more frequent in BC (74.5%) than in CP (38%) (Po0.0001). Furthermore, L1 hypomethylation led to activation of both ORF1 sense transcription (Po0.0001) and c-MET gene antisense transcription (Po0.0001), and was significantly associated with high levels of BCR–ABL (P¼0.02) and DNMT3b4 (P¼0.001) transcripts. Interestingly, in CP-CML, extensive L1 hypomethylation was associated with poorer prognosis in terms of cytogenetic response to interferon (P¼0.004) or imatinib (P¼0.034) and progression-free survival (P¼0.005). The above results strongly suggest that activation of both sense and antisense transcriptions by aberrant promoter hypomethylation of the L1 elements plays a role in the progression and clinical behavior of the CML

    DISEÑO DEL PULSO ÓPTIMO DE RIEGO EN EL CULTIVO DE FRESA CON EL MODELO NUMÉRICO HYDRUS 2D

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    [ES] El cultivo intensivo de fresa, que se desarrolla en macrotúneles de plástico sobre lomos acolchados, demanda volúmenes importantes de agua para satisfacer las necesidades hídricas del cultivo así como para labores de preparación del suelo o alomado y riego de apoyo en la fase de plantación. El riego de la fresa es especialmente complejo dado que es un cultivo que se produce bajo plástico en suelos muy arenosos (habitualmente con un contenido de arena superior al 90%), con escasa capacidad de retención de agua. A pesar de esta dificultad, no es habitual que exista una programación del riego basada en la medida de las principales variables que afectan al cálculo de las necesidades hídricas del cultivo. En este trabajo se proponen medidas de mejora en el manejo del riego, basadas en la determinación del pulso óptimo que evite las pérdidas por percolación en tres fases de desarrollo del cultivo. Para ello se ha utilizado el modelo de simulación del movimiento del agua en el suelo Hydrus 2D. Se han simulado diferentes estrategias de riego para aplicar la ETc del cultivo con emisores de 5 l.h-1.m en tres etapas diferentes del cultivo, inicio, mediados, y final de campaña y en las que por término medio se necesitan tiempos de riego que oscilan entre los 10-20 minutos al inicio de la campaña y 40-60 minutos al final de campañaGarcía Morillo, J.; Rodríguez-Díaz, J.; Martín Arroyo, M.; Camacho Poyato, E.; Montesinos Barrios, P. (2015). DISEÑO DEL PULSO ÓPTIMO DE RIEGO EN EL CULTIVO DE FRESA CON EL MODELO NUMÉRICO HYDRUS 2D. En XXXIII CONGRESO NACIONAL DE RIEGOS. Valencia 16-18 junio de 2015. Editorial Universitat Politècnica de València. https://doi.org/10.4995/CNRiegos.2015.1472OC
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