38 research outputs found

    Rotational Doppler Effect in Magnetic Resonance

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    We compute the shift in the frequency of the spin resonance in a solid that rotates in the field of a circularly polarized electromagnetic wave. Electron spin resonance, nuclear magnetic resonance, and ferromagnetic resonance are considered. We show that contrary to the case of the rotating LC circuit, the shift in the frequency of the spin resonance has strong dependence on the symmetry of the receiver. The shift due to rotation occurs only when rotational symmetry is broken by the anisotropy of the gyromagnetic tensor, by the shape of the body, or by magnetocrystalline anisotropy. General expressions for the resonance frequency and power absorption are derived and implications for experiment are discussed.Comment: 8 pages, 4 figure

    Automatic Positional Accuracy Assessment of Imagery Segmentation Processes: A Case Study

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    There are many studies related to Imagery Segmentation (IS) in the field of Geographic Information (GI). However, none of them address the assessment of IS results from a positional perspective. In a field in which the positional aspect is critical, it seems reasonable to think that the quality associated with this aspect must be controlled. This paper presents an automatic positional accuracy assessment (PAA) method for assessing this quality component of the regions obtained by means of the application of a textural segmentation algorithm to a Very High Resolution (VHR) aerial image. This method is based on the comparison between the ideal segmentation and the computed segmentation by counting their differences. Therefore, it has the same conceptual principles as the automatic procedures used in the evaluation of the GI's positional accuracy. As in any PAA method, there are two key aspects related to the sample that were addressed: (i) its size-specifically, its influence on the uncertainty of the estimated accuracy values-and (ii) its categorization. Although the results obtained must be taken with caution, they made it clear that automatic PAA procedures, which are mainly applied to carry out the positional quality assessment of cartography, are valid for assessing the positional accuracy reached using other types of processes. Such is the case of the IS process presented in this study

    Clonal human fetal ventral mesencephalic dopaminergic neuron precursors for cell therapy research

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    A major challenge for further development of drug screening procedures, cell replacement therapies and developmental studies is the identification of expandable human stem cells able to generate the cell types needed. We have previously reported the generation of an immortalized polyclonal neural stem cell (NSC) line derived from the human fetal ventral mesencephalon (hVM1). This line has been biochemically, genetically, immunocytochemically and electrophysiologically characterized to document its usefulness as a model system for the generation of A9 dopaminergic neurons (DAn). Long-term in vivo transplantation studies in parkinsonian rats showed that the grafts do not mature evenly. We reasoned that diverse clones in the hVM1 line might have different abilities to differentiate. In the present study, we have analyzed 9 hVM1 clones selected on the basis of their TH generation potential and, based on the number of v-myc copies, v-myc down-regulation after in vitro differentiation, in vivo cell cycle exit, TH+ neuron generation and expression of a neuronal mature marker (hNSE), we selected two clones for further in vivo PD cell replacement studies. The conclusion is that homogeneity and clonality of characterized NSCs allow transplantation of cells with controlled properties, which should help in the design of long-term in vivo experimentsThis work was supported by grants from the Spanish Ministry of Economy and Competitiveness (formerly Science and Innovation; PLE2009-0101, SAF2010-17167), Comunidad AutĂłnoma Madrid (S2011-BMD-2336), Instituto Salud Carlos III (RETICS TerCel, RD06/0010/0009) and European Union (Excell, NMP4-SL-2008-214706). This work was also supported by an institutional grant from Foundation RamĂłn Areces to the Center of Molecular Biology Severo Ocho

    A study of the dry forest communities in the Dominican Republic

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    This paper is a floristic and phytosociological study of the dry forest communities of the Dominican Republic. A total of 69 relevĂ©s in dry forest biotopes were carried out. The samples were subsequently subjected to Detrended Correspondence Analysis for the determination and study of possible groupings. The study does not cover tree formations growing on serpentines, nor the so-called semideciduous forests, peculiar to areas with higher rainfall. A total of nine phytocoenoses were identified. The most significant results led to the description of six new phytosociological associations: Simaroubetum berteroani (thorny dry forest on coastal dunes), Phyllostylo rhamnoidis-Prosopidetum juliflorae (southern Dominican disturbed dry forest), Consoleo moniliformis-Camerarietum linearifoliae (dry forest on hard limestones), Lemaireocereo hystricis-Prosopidetum juliflorae (northern Dominican disturbed dry forest), Lycio americani-Prosopidetum juliflorae (disturbed dry forest on saline soils) and Guettardo ellipticae-Guapiretum discoloris (dry forest on flat-topped hillocks in Montecristi). This is an important step forward in the phytosociological and floristic studies of the Caribbean territories.Este trabalho apresenta um estudo florĂ­stico e fitossociolĂłgico das comunidades de florestas secas da RepĂșblica Dominicana. Um total de 69 amostras foram obtidas pelo mĂ©todo relevĂ© em biĂłtopos florestais secos. As amostras foram posteriormente submetidas Ă  anĂĄlise de correspondĂȘncia destendenciada para a determinação e estudo de possĂ­veis agrupamentos. O estudo nĂŁo abrange formaçÔes arbĂłreas desenvolvidas sobre serpentinitos, nem as chamadas florestas semideciduais, peculiares Ă s ĂĄreas de maior pluviosidade. Foram identificados nove fitocenoses. Os resultados mais significativos levaram Ă  descrição de seis novas associaçÔes fitossociolĂłgicas: Simaroubetum berteroani (floresta espinhosa seca em dunas costeiras), Phyllostylo rhamnoidis-Prosopidetum juliflorae (floresta seca perturbada do sul da RepĂșblica Dominicana), Consoleo moniliformis-Camerarietum linearifoliae (floresta seca sobre calcĂĄrios compactos), Lemaireocereo hystricis-Prosopidetum juliflorae (floresta seca perturbada do norte da RepĂșblica Dominicana), Lycio americani-Prosopidetum juliflorae (floresta seca perturbada desenvolvida em solos salinos) Guettardo ellipticae-Guapiretum discoloris (floresta seca em colinas de topo achatado em Montecristi). O trabalho realizado representa um importante avanço nos estudos fitossociolĂłgicos e florĂ­sticos dos territĂłrios do Caribe.This research paper was possible thanks to the sponsorship of the Agencia Española de CooperaciĂłn Internacional para el Desarrollo (AECID), under the auspices of the Ministerio de Asuntos Exteriores y de CooperaciĂłn de España, which funded the project (cod. A/3499/05)

    Time to Switch to Second-line Antiretroviral Therapy in Children With Human Immunodeficiency Virus in Europe and Thailand.

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    Background: Data on durability of first-line antiretroviral therapy (ART) in children with human immunodeficiency virus (HIV) are limited. We assessed time to switch to second-line therapy in 16 European countries and Thailand. Methods: Children aged <18 years initiating combination ART (≄2 nucleoside reverse transcriptase inhibitors [NRTIs] plus nonnucleoside reverse transcriptase inhibitor [NNRTI] or boosted protease inhibitor [PI]) were included. Switch to second-line was defined as (i) change across drug class (PI to NNRTI or vice versa) or within PI class plus change of ≄1 NRTI; (ii) change from single to dual PI; or (iii) addition of a new drug class. Cumulative incidence of switch was calculated with death and loss to follow-up as competing risks. Results: Of 3668 children included, median age at ART initiation was 6.1 (interquartile range (IQR), 1.7-10.5) years. Initial regimens were 32% PI based, 34% nevirapine (NVP) based, and 33% efavirenz based. Median duration of follow-up was 5.4 (IQR, 2.9-8.3) years. Cumulative incidence of switch at 5 years was 21% (95% confidence interval, 20%-23%), with significant regional variations. Median time to switch was 30 (IQR, 16-58) months; two-thirds of switches were related to treatment failure. In multivariable analysis, older age, severe immunosuppression and higher viral load (VL) at ART start, and NVP-based initial regimens were associated with increased risk of switch. Conclusions: One in 5 children switched to a second-line regimen by 5 years of ART, with two-thirds failure related. Advanced HIV, older age, and NVP-based regimens were associated with increased risk of switch

    Un contexto tardorrepublicano de Ilici

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    Póster presentado en el Congreso Internacional de Arqueología "Cultura material romana en la Hispania Republicana. Contextos privilegiados y estado de la cuestión" celebrado en Lezuza (Libisosa) del 22-24 abril de 2016.Propuesta de datación e interpretación del contexto original del célebre kalathos conocido como "Vaso de las peponas" o "Vaso de la tonta del bote" hallado en Ilici (La Alcudia de Elche) en 1943 por Alejandro Ramos Folqués. El estudio estå basado en la revisión y actualización de datos de los de los cuadernos de campo y publicaciones de Ramos Folqués

    Physiotherapy applied to palliative care patients: a descriptive practice-based study

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    Abstract Background Over the last few years, the presence of physiotherapists in Palliative Care Units (PCU) has considerably grown based on evidence from studies supporting the use of non-pharmacological measures as part of Palliative Care (PC) treatments. However, more accumulated data are needed to definitively establish its added value. The present study describes the type of patients receiving physiotherapy in a PCU and the benefits obtained in relation to their degree of functional dependence. Methods An observational, prospective, descriptive, practice-based study was undertaken involving patients admitted to the PCU of FundaciĂłn Instituto San JosĂ© (Madrid, Spain), who according to the PCUÂŽs clinical practice, met the criteria for physiotherapy intervention. Daily clinical practice was unchanged for study reasons. Participants were assessed prior to initiating and at the end of the physiotherapy program using the following standard scales: the Barthel Index, the Functional Ambulation Categories scale, the Palliative Performance Scale, and the Braden scale. A descriptive analysis was performed and scale scores prior to and after treatment were compared using the Wilcoxon signed-rank test. Significance was set at 0.05. Results A total of 63 patients were included (mean age 71.98 ± 12.72; 61.9% males). Fifty-eight patients (92.1%) were oncological patients; of them, 35 (60.3%) had metastases. Prior to treatment, 28 (44.4%) participants had total dependence according to the Barthel index, and 37 (58.7%) were non-functional ambulator according to the FAC scale. At the end of treatment, the number of patients with total dependence decreased to 15 (23.8%) and those non-functional ambulator to 12 (19.0%). Conclusions Patients who benefited from physical therapy during their admission to our PCU were predominantly males with oncological processes, mainly lung cancer. PC including physiotherapy improved their functionality, independence and skills for activities of daily living in this sample of PCU patients

    A Polygon and Point-Based Approach to Matching Geospatial Features

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    A methodology for matching bidimensional entities is presented in this paper. The matching is proposed for both area and point features extracted from geographical databases. The procedure used to obtain homologous entities is achieved in a two-step process: The first matching, polygon to polygon matching (inter-element matching), is obtained by means of a genetic algorithm that allows the classifying of area features from two geographical databases. After this, we apply a point to point matching (intra-element matching) based on the comparison of changes in their turning functions. This study shows that genetic algorithms are suitable for matching polygon features even if these features are quite different. Our results show up to 40% of matched polygons with differences in geometrical attributes. With regards to point matching, the vertex from homologous polygons, the function and threshold values proposed in this paper show a useful method for obtaining precise vertex matching

    Un contexto tardorrepublicano de Ilici

    No full text
    Póster presentado en el Congreso Internacional de Arqueología "Cultura material romana en la Hispania Republicana. Contextos privilegiados y estado de la cuestión" celebrado en Lezuza (Libisosa) del 22-24 abril de 2016.Propuesta de datación e interpretación del contexto original del célebre kalathos conocido como "Vaso de las peponas" o "Vaso de la tonta del bote" hallado en Ilici (La Alcudia de Elche) en 1943 por Alejandro Ramos Folqués. El estudio estå basado en la revisión y actualización de datos de los de los cuadernos de campo y publicaciones de Ramos Folqués
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