426 research outputs found
Análisis factorial de datos cualitativos: un experimento con datos artificiales
In this work some properties and applications of different factor analysis techniques of qualitative data are discussed. Using an artiflcially generated set of data we show that the principal component analysis of the total coincidence matrix (rotated Solutions) and the analysis of correspondences are the most relevant for studies of descriptive ecology.En este trabajo se discuten algunas propiedades y aplicaciones de diferentes técnicas de análisis factorial de datos cualitativos (análisis de componentes principales de la matriz de contingencias múltiples y de coincidencias totales y análisis de correspondencias). Los datos utilizados se han generado de forma artificial, haciendo variar los comportamientos de las variables en sus presencias y ausencias. Se muestra que el análisis de componentes principales de la matriz de coincidencias totales (soluciones rotadas) y el análisis de correspondencias presentan las mayores ventajas de utilización en estudios de tipificación de comunidades en ecología descriptiva
Depression symptoms and mortality in elderly peruvian navy veterans: a retrospective cohort study
Abstract: Our study was design to determine the association between depressive symptoms and mortality in adults over 60 years old Navy Peruvian Veterans. We performed a retrospective cohort study based on a previous cohort study. A total of 1681 patients over 60 years old were included between 2010–2015. Demographic information, self-reported information about falls, physical frailty assessment, tobacco consumption, hypertension, Type 2 Diabetes Mellitus, Chronic Obstructive Pulmonary Disease and was collected. Depression was assessed by the short form of the Geriatric Depression Scale. We found that depressive symptoms were present in 24.9% of the participants and 40.5% of them died. Mortality risk in patients with depressive symptoms, physical frailty, and male sex was: RR of 23.1 (95% CI: 11.7–45.7), 3.84 (95% CI: 2.16–6.82), and 1.37 (95% CI: 1.07–1.75) respectively. We concluded that depressive symptoms in Peruvian retired military personnel and their immediate relatives are high and are significatively associated with mortality. Also, being male and frail was associated with an increased risk of death. This reinforces that early detection and assessment of depressive symptoms could be an opportunity to improve the health status of older adults
Thematic Trends in Complementary and Alternative Medicine Applied in Cancer-Related Symptoms
Purpose: The main goal of this study is to discover the scientific evolution of Cancer-Related
Symptoms in Complementary and Alternative Medicine research area, analyzing the articles
indexed in the Web of Science database from 1980 to 2013.
Design/Methodology/Approach: A co-word science mapping analysis is performed under a
longitudinal framework (1980 to 2013). The documental corpus is divided into two subperiods,
1980–2008 and 2009–2013. Thus, the performance and impact rates, and conceptual evolution
of the research field are shown.
Findings: According to the results, the co-word analysis allows us to identify 12 main
thematic areas in this emerging research field: anxiety, survivors and palliative care,
meditation, treatment, symptoms and cancer types, postmenopause, cancer pain, low back
pain, herbal medicine, children, depression and insomnia, inflammation mediators, and
lymphedema. The different research lines are identified according to the main thematic areas,
centered fundamentally on anxiety and suffering prevention. The scientific community can
use this information to identify where the interest is focused and make decisions in different
ways.
Research limitation: Several limitations can be addressed: 1) some of the Complementary
and Alternative Medicine therapies may not have been included; 2) only the documents
indexed in Web of Science are analyzed; and 3) the thematic areas detected could change if
another dataset was considered.
Practical implications: The results obtained in the present study could be considered as an
evidence-based framework in which future studies could be built.
Originality/value: Currently, there are no studies that show the thematic evolution of this
research area
Extremely Long-Lived Stigmas Allow Extended Cross-Pollination Opportunities in a High Andean Plant
High-elevation ecosystems are traditionally viewed as environments in which predominantly autogamous breeding systems should be selected because of the limited pollinator availability. Chaetanthera renifolia (Asteraceae) is an endemic monocarpic triennial herb restricted to a narrow altitudinal range within the high Andes of central Chile (3300–3500 m a.s.l.), just below the vegetation limit. This species displays one of the larger capitulum within the genus. Under the reproductive assurance hypothesis, and considering its short longevity (monocarpic triennial), an autogamous breeding system and low levels of pollen limitation would be predicted for C. renifolia. In contrast, considering its large floral size, a xenogamous breeding system, and significant levels of pollen limitation could be expected. In addition, the increased pollination probability hypothesis predicts prolonged stigma longevity for high alpine plants. We tested these alternative predictions by performing experimental crossings in the field to establish the breeding system and to measure the magnitude of pollen limitation in two populations of C. renifolia. In addition, we measured the stigma longevity in unpollinated and open pollinated capitula, and pollinator visitation rates in the field. We found low levels of self-compatibility and significant levels of pollen limitation in C. renifolia. Pollinator visitation rates were moderate (0.047–0.079 visits per capitulum per 30 min). Although pollinator visitation rate significantly differed between populations, they were not translated into differences in achene output. Finally, C. renifolia stigma longevity of unpollinated plants was extremely long and significantly higher than that of open pollinated plants (26.3±2.8 days vs. 10.1±2.2, respectively), which gives support to the increased pollination probability hypothesis for high-elevation flowering plants. Our results add to a growing number of studies that show that xenogamous breeding systems and mechanisms to increase pollination opportunities can be selected in high-elevation ecosystems
El papel de los estudios bioarqueológicos en las interpretaciones sobre las comunidades neolíticas del noreste peninsular
Resumen del trabajo presentado al VI Congreso del Neolítico en la Península Ibérica: "Los cambios económicos y sus implicaciones sociales durante el Neolítico de la Península Ibérica", celebrado en Granada del 22 al 26 de junio de 2016.-- et al.El marco del proyecto I+D: “Aproximación a las primeras comunidades neolíticas del NE peninsular a través de sus prácticas funerarias” (2011-2015), y su continuidad para los próximos cuatro años al haber sido renovado, tiene por objetivo conocer cada día más y mejor las comunidades de agricultores y pastores que entre finales del V e inicios del IV milenio cal BC ocuparon y enterraron a sus muertos en el noreste de la Península Ibérica. El contexto de estudio es excepcional, puesto que aquellas comunidades inhumaron sistemáticamente a sus congéneres en tumbas habitualmente individuales y ocasionalmente junto a otro individuo. En esta presentación no sólo queremos mostrar los nuevos análisis y metodologías que estamos aplicando al estudio de los restos humanos, sino también el modelo de trabajo que hemos seguido. A este respecto, tres aspectos son fundamentales: 1) las dataciones absolutas son el eje que vertebra los posteriores análisis; 2) la colaboración con los distintos investigadores/as y laboratorios debe ser estrecha (no es cuestión de solicitar los resultados de un análisis a un laboratorio sino trabajar con las personas que manipulan las muestras y conocen los pros y contras de cada una de las técnicas empleadas) y 3) los estudios y análisis a realizar confluyen para responder a las hipótesis planteadas. A este respecto, en el proyecto hemos tenido la fortuna de poder colaborar con numerosos investigadores/as cuya especialidad versa alrededor de los restos funerarios y que firman la presente comunicación: análisis isotópicos, Adn, tafonomía funeraria, estudios de stress muscular y análisis de morfología dental.Peer Reviewe
Trichinellosis survey in wild fauna from various regions of Spain
Se presentan los resultados del estudio de vigilancia epidemiológica de triquinelosis (Trichinella spiralis y T. britovi) en fauna salvaje (jabalí y zorro), llevado a cabo en Catalunya (2006-2008), La Rioja (2001-2003) y Castilla-La Mancha (2007-2008). Las prevalencias fluctúan entre 0,7-0,93 % en jabalí y 0,64-4,2 % en zorro. Póster. EPI 27. Abstract Book. 4th Annual Scientific Meeting (2008). MED-VET-NET. Saint-Malo, France. Autores: Manzano-Lorenzo R., Nogal-Ruíz J.J., Fonseca-Salamanca F., García-Sancho R.N., Arroyo-Díaz J.M., Jiménez S., Fàbregas X., Colomer A., Bolás-Fernández F., Martínez-Fernández A.M. 520 3_ $a Es presenten els resultats de l'estudi de vigilància epidemiològica de triquinel·losis (Trichinella spiralis y T. britovi) en fauna salvatge (porc senglar i guineu), portat a terme a Catalunya (2006-2008), La Rioja (2001-2003) i Castilla-La Mancha (2007-2008). Les prevalences fluctuen entre 0,7-0,93 % en senglar i 0,64-4,2 % en guineu. Pòster. EPI 27. Abstract Book. 4th Annual Scientific Meeting (2008). MED-VET-NET. Saint-Malo, France
In vitro Induction of Entamoeba histolytica Cyst-like Structures from Trophozoites
Inhibition of encystment can be conceived as a potentially useful mechanism to block the transmission of Entamoeba histolytica under natural conditions. Unfortunately, amoeba encystment has not been achieved in vitro and drugs inhibiting the formation of cysts are not available. Luminal conditions inducing encystment in vivo are also unknown, but cellular stress such as exposure to reactive oxygen species from immune cells or intestinal microbiota could be involved. A role for certain divalent cations as cofactors of enzymes involved in excystment has also been described. In this study, we show that trophozoite cultures, treated with hydrogen peroxide in the presence of trace amounts of several cations, transform into small-sized spherical and refringent structures that exhibit resistance to different detergents. Ultrastructural analysis under scanning and transmission electron microscopy revealed multinucleated structures (some with four nuclei) with smooth, thick membranes and multiple vacuoles. Staining with calcofluor white, as well as an ELISA binding assay using wheat germ agglutinin, demonstrated the presence of polymers of N-acetylglucosamine (chitin), which is the primary component of the natural cyst walls. Over-expression of glucosamine 6-phosphate isomerase, likely to be the rate-limiting enzyme in the chitin synthesis pathway, was also confirmed by RT-PCR. These results suggest that E. histolytica trophozoites activated encystment pathways when exposed to our treatment
Very high energy particle acceleration powered by the jets of the microquasar SS 433
SS 433 is a binary system containing a supergiant star that is overflowing
its Roche lobe with matter accreting onto a compact object (either a black hole
or neutron star). Two jets of ionized matter with a bulk velocity of
extend from the binary, perpendicular to the line of sight, and
terminate inside W50, a supernova remnant that is being distorted by the jets.
SS 433 differs from other microquasars in that the accretion is believed to be
super-Eddington, and the luminosity of the system is erg
s. The lobes of W50 in which the jets terminate, about 40 pc from the
central source, are expected to accelerate charged particles, and indeed radio
and X-ray emission consistent with electron synchrotron emission in a magnetic
field have been observed. At higher energies (>100 GeV), the particle fluxes of
rays from X-ray hotspots around SS 433 have been reported as flux
upper limits. In this energy regime, it has been unclear whether the emission
is dominated by electrons that are interacting with photons from the cosmic
microwave background through inverse-Compton scattering or by protons
interacting with the ambient gas. Here we report TeV -ray observations
of the SS 433/W50 system where the lobes are spatially resolved. The TeV
emission is localized to structures in the lobes, far from the center of the
system where the jets are formed. We have measured photon energies of at least
25 TeV, and these are certainly not Doppler boosted, because of the viewing
geometry. We conclude that the emission from radio to TeV energies is
consistent with a single population of electrons with energies extending to at
least hundreds of TeV in a magnetic field of ~micro-Gauss.Comment: Preprint version of Nature paper. Contacts: S. BenZvi, B. Dingus, K.
Fang, C.D. Rho , H. Zhang, H. Zho
Long-term effect of 2 intensive statin regimens on treatment and incidence of cardiovascular events in familial hypercholesterolemia : The SAFEHEART study
Funding: This study was supported by Fundación Hipercolesterolemia Familiar; Grant G03/181 Grant 08-2008 Centro Nacional de Investigaci?n Cardiovascular (CNIC).Background: Maximal doses of potent statins are the basement of treatment of familial hypercholesterolemia (FH). Little is known about the use of different statin regimens in FH. Objectives: The objectives of the study were to describe the treatment changes and low-density lipoprotein cholesterol (LDL-C) goal achievement with atorvastatin (ATV) and rosuvastatin (RV) in the SAFEHEART cohort, as well as to analyze the incidence of atherosclerotic cardiovascular events (ACVEs) and changes in the cardiovascular risk. Methods: SAFEHEART is a prospective follow-up nationwide cohort study in a molecularly defined FH population. The patients were contacted on a yearly basis to obtain relevant changes in life habits, medication, and ACVEs. Results: A total of 1939 patients were analyzed. Median follow-up was 6.6 years (5-10). The estimated 10-year risk according the SAFEHEART risk equation was 1.61 (0.67-3.39) and 1.22 (0.54-2.93) at enrollment for ATV and RV, respectively (P <.001). There were no significant differences at the follow-up: 1.29 (0.54-2.82) and 1.22 (0.54-2.76) in the ATV and RV groups, respectively (P =.51). Sixteen percent of patients in primary prevention with ATV and 18% with RV achieved an LDL-C <100 mg/dL and 4% in secondary prevention with ATV and 5% with RV achieved an LDL-C <70 mg/dL. The use of ezetimibe was marginally greater in the RV group. One hundred sixty ACVEs occurred during follow-up, being its incidence rate 1.1 events/100 patient-years in the ATV group and 1.2 in the RV group (P =.58). Conclusion: ATV and RV are 2 high-potency statins widely used in FH. Although the reduction in LDL-C levels was greater with RV than with ATV, the superiority of RV for reducing ACVEs was not demonstrated
Optimization of Pathogenicity Tests for Selection of Native Isolates of Entomopathogenic Fungi Isolated from Citrusgrowing Areas of México on Adults ofDiaphorina citriKuwayama (Hemiptera: Liviidae)
Huanglonbing (HLB), es considerado una de las más letales enfermedades de los cítricos alrededor del mundo, y ha alcanzado las principales áreas de producción de limón Mexicano (Citrus latifolia Tanaka) en la costa del pacifico de México. Los productores han iniciado el uso de insecticidas para controlar las poblaciones del psílido asiático de los cítricos, Diaphorina citri Kuwayama (Hemiptera: Liviidae), el vector del patógeno ‘Candidatus Liberibacter asiaticus’ asociado con el HLB. Actualmente los costos de los insecticidas y los efectos secundarios de su uso son las principales preocupaciones, ya que podrían perjudicar la estrategia de manejo contra el vector; y por lo tanto, alternativas ecológicas y económicamente viables a los insecticidas convencionales serian necesarias a corto plazo. Por tanto, el objetivo de este estudio fue evaluar la patogenicidad de 27 aislados nativos y 3 cepas de hongos entomopatógenos para determinar su potencial como agentes de control biológico sobre Diaphorina citri usando 2 diferentes métodos de bioensayo. Los bioensayos fueron realizados bajo condiciones de laboratorio (26 ± 2 °C, 60 ± 5% H.R y 16:8 h L:O) mediante la exposición de insectos adultos a una concentración de 1 × 108 conidios por mililitro utilizando 2 diferentes métodos de aplicación, es decir, por asperjado de esporas en las plántulas de cítricos y por asperjado directo a los psílidos adultos. Los resultados mostraron que para el asperjado directo a los adultos los aislados HIB-24 (B. bassiana) y HIB-32 (I. fumosorosea) mostraron el mayor porcentaje de mortalidad (60.66%). Respecto al asperjado de plántulas el aislado HIB-19 (I. fumosorosea) mostró el mayor porcentaje de mortalidad (62.02%). Los resultados de este estudio demuestran el potencial para el uso de hongos entomopatógenos en el manejo de D. citri en México.
ABSTRACT
Huanglongbing (HLB), considered one of the most lethal diseases of citrus worldwide, has reached the main areas of Mexican lime (Citrus latifolia Tanaka) fruit production on the Pacific coast of México. Growers have initiated intensive use of insecticides in order to control populations of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), the vector of the pathogen, ‘Candidatus Liberibacter asiaticus’ associated with huanglongbing. Presently, costs of insecticides and the side effects of their use are major concerns, because they could impair the management strategy against the vector; and thus, ecologically and economically viable alternatives to conventional insecticides are required in the short term. Therefore the goal of this study was to evaluate the pathogenicity of 27 native isolates and 3 strains of entomopathogenic fungi and determine their potential as biological control agents of D. citri by using 2 different bioassay methods. Bioassays were performed under laboratory conditions (26 ± 2 °C, 60 ± 5% RH and 16:8 h L:D) by exposing adult insects to a concentration of 1 × 108 conidia per milliliter using 2 different application methods, i.e., spraying the spores onto the citrus seedlings and spraying the spores directly onto the adult psyllids. The results showed that by direct spraying the adults, HIB-24 (B. bassiana) and HIB-32 (I. fumosorosea) isolates showed the highest mortality (60.66%). Regarding spraying of the seedlings, HIB-19 (I. fumosorosea) showed the highest percentage of mortality (62.02%). The results from this study demonstrate potential for using entomopathogenic fungi in the management of D. citri in México
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