76 research outputs found

    Variación de historias de vida y demografía de la planta invasora Eschscholzia californica Cham. (Papaveraceae) en dos extremos altitudinales, Chile central

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    In this study, we compared demographic responses of Eschscholzia californica populations located at different altitude,under the basic assumption that altitudinal gradients impose environmental limitation to the spread at the upper edge of thegradient. We detected significant differences among populations either in terms of life history attributes and the finite rateof increase. In general, coastal population expressed higher finite population rates than mountain populations, althoughthese differences were not statistically significant. Mountain populations (Corral Quemado and Farellones) expressed afinite population rate not significant different of 1. These result suggest that at the upper front of invasion the species is in ademographic equilibrium because in spite of we detected a higher plant fecundity, there exist ecological constraints a seedstage level. We proposed to address more specific studies assessing from one hand, seed movement from lower altitudesand the efficiency of domestic cattle as biotic vector; we also propose to examine the feasibility of this species to establishpositive interactions with cushion plants, and therefore to expand its geographic range due to this facilitation effect.En este estudio comparamos las respuestas demográficas de las poblaciones de Eschscholzia californica ubicadas adiferentes altitudes, bajo el supuesto básico de que los gradientes altitudinales imponen limitaciones a la invasión. Sedetectaron diferencias significativas entre las poblaciones, ya sea en términos de atributos de la historia de vida y tasafinita de crecimiento. En general, las poblaciones costeras expresaron mayores tasas de crecimiento que las poblacionesde montaña, aun cuando éstas no fueron estadísticamente significativas. Las poblaciones de montaña (Corral Quemadoy Farellones) fueron las únicas que mostraron una tasa de crecimiento similar a 1. Estos resultados sugieren que laspoblaciones ubicadas en el frente superior de invasión estarían en un equilibrio demográfico debido a que aun cuandose detectó una elevada fecundidad, existen restricciones ecológicas a nivel de las semillas. Proponemos hacer estudiosmás específicos para evaluar un posible movimiento de semillas desde altitudes más bajas y la eficiencia del ganadodoméstico como vector transportador de estas semillas; proponemos también examinar la posibilidad que tiene esta plantade establecer interacciones positivas con las plantas en cojín, ubicadas a mayores alturas y, por lo tanto, ampliar su rangoaltitudinal debido a este efecto de facilitación

    El cambio evolutivo en el nicho de germinación de dos especies relacionadas dentro del clado Neoporteria (Cactaceae) es idiosincrático al tipo de hábitat

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    An appropriate germination response to environmental conditions is the first requirement for the establishment of a plant in a determined geographic area; therefore changes in the germination niche may be critical in configuring the current pattern of species distributions. Furthermore, the spread of many Neotropical groups to higher latitudes are constrained by the combination of cold and humid conditions. This raises the question whether evolutionary trends in germination niche are essential for the mechanism that allows the colonization of edge habitats characterized by humid and cold conditions. Here, we evaluated the variation of seed germination probabilities of two species of cacti (Neoporteria clade), closely related but endemic to habitats with different temperature and water availability conditions. The germination niche and differences in germination performance of Eriosyce subgibbosa and E. villosa were evaluated, using common garden experiments and varying temperature and soil water potential (?) conditions. Seeds of E. subgibbosa showed overall higher germination probabilities compared to E. villosa. Interestingly, most of the detected differences on seed germination performance are related with a higher ability of E. subgibbosa seeds to germinate under conditions with more water availability and under colder conditions compared to E. villosa seed germination. This study highlights one of the critical features that could be involved in the mechanism that leads to the expansion of the Neoporteria clade to more mesic habitats. Particularly the adaptation of the germination niche of E. subgibbosa may allow an expansion from an arid habitat that characterized basal species of the group (plesiomorphic state) to more humid and cold habitats.Una respuesta apropiada a las condiciones ambientales es el primer requisito para el establecimiento de una planta en un área geográfica, por lo tanto cambios en el nicho de germinación podrían ser críticos en configurar el actual patrón de distribución de especies. Además, la propagación de muchos grupos de origen neotropical hacia altas latitudes está limitada por la combinación de condiciones frías y alta humedad. Esto lleva a preguntarse si las tendencias evolutivas en el nicho de la germinación son esenciales en el mecanismo que permite la colonización del borde del hábitat caracterizado por ser frío y húmedo. Por ello, evaluamos la variación en las probabilidades de germinación de dos especies de cactáceas (clado Neoporteria), cercanamente relacionadas pero endémicas a hábitats con diferentes condiciones de temperatura y disponibilidad de agua. Usando experimentos de jardín común se varió la temperatura y el potencial osmótico del sustrato (?), se caracterizó el nicho evaluando las diferencias germinativas en Eriosyce subgibbosa y E. villosa. Las semillas de E. subgibbosa mostraron en general mayor germinación que las semillas de E. villosa. Interesantemente, la mayoría de las diferencias detectadas en la germinación de semillas están relacionadas con la mayor habilidad de las semillas de E. subgibbosa a germinar bajo condiciones de mayor disponibilidad hídrica y menores temperaturas comparado con la germinación de E. villosa. Este estudio llama la atención sobre uno de los aspectos críticos que podrían estar involucrados con el mecanismo que podría llevar la expansión del clado Neoporteria a hábitats más mésicos. Particularmente la adaptación del nicho de germinación de E. subgibbosa podría permitir la expansión en la distribución de un habitat árido que caracteriza a las especies basales del grupo como E. villosa (carácter plesiomórfico) hacia hábitats más húmedos y fríos

    Fotoblastismo negativo en la especie invasora Eschscholzia californica Cham. (Papaveraceae): Patrones de variación altitudinal en el rango nativo e introducido

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    Negative photoblastism is defined as the inhibitory effect of light on seed germination. This effect can be modulated by abiotic variables, such as temperature, light condition and water potential. This conditions change notoriously at higher altitudes, could promote differentiations in the photoblastic response among populations. Also, this physiological attribute poses an interesting conflict for plant regeneration, because prevents seed germination on the soil surface, however, it can also to reduce the mortality of seeds germinants in unsuitable conditions and consequently, seedling mortality. Eschscholzia californica is one of the few species with negative photoblastism and it is invasive in Chile, growing primarily in open and disturbed places. Some invasive species have the potential to adapt their morphological and ecophysiological characteristics faced to new environmental conditions. In this study, we examined variation in negative photoblastism between populations from central Chile (invasive) and California (native) located at the extremes of their altitudinal distribution. We used common garden experiments where seeds from different origins were germinated under controlled lab condition in Chile. If negative photoblastism is conserved, we would see similar responses among seeds original from this climatic analogues regions. Also, we evaluated whether seed burial increases seed germination of this species as a mechanism for escaping the intense luminosity at the soil surface, by planting seeds at different soil depths. For this experiment, we expected an increase of germination at higher soil depth. The results indicate no differences in negative photoblastism between Chilean and Californian populations. A significant variation across altitudinal range in California suggests the existence of genetic differentiation in the native region, however, the absence of differences across the altitudinal range in Chile suggests trait conservatism at local scale. Seed germination was zero at the soil surface and increased when seeds were experimentally buried, suggesting that negative photoblastism is inhibited. Three possible explanations are given to explain the pattern of establishment of E. californica despite having negative photoblastism. This is a fairly specialist trait, related with Mediterranean climates and does not explain by itself the invasiveness described for this specie. In any case, is clear that more studies are necessary to disentangle the adaptive value of this physiological trait.El fotoblastismo negativo es definido como el efecto inhibitorio de la luz sobre la germinación de las semillas. Este efecto puede ser modulado por variables abióticas, tales como temperatura, condición lumínica y potencial hídrico. Estas condiciones cambian notoriamente a mayores altitudes, pudiendo promover diferenciación en la respuesta fotoblástica entre poblaciones. Adicionalmente, este atributo fisiológico presenta un interesante conflicto para la regeneración de la planta, porque previene la germinación de las semillas sobre el suelo, sin embargo también puede reducir la mortalidad de semillas germinantes en condiciones desfavorables y consecuentemente, la mortalidad de plántulas. Eschscholzia californica es una de las pocas especies con fotoblastismo negativo y es invasora en Chile, creciendo primariamente en sitios abiertos e intervenidos. Algunas especies invasoras tienen el potencial de adaptar sus características morfológicas y fisiológicas enfrentadas a nuevas condiciones ambientales. En este estudio, examinamos la existencia de variación en el fotoblastismo negativo entre poblaciones de Chile central (invasivas) y California (nativas) localizadas en los extremos de su distribución altitudinal. Utilizamos experimentos de jardín común donde semillas de distintos orígenes fueron germinadas bajo condiciones controladas de laboratorio en Chile. Si el fotoblastismo negativo es conservado, observaríamos similares respuestas entre semillas originarias de estas regiones climáticas análogas. También evaluamos si el entierro de las semillas incrementa su germinación, como un mecanismo para escapar de la intensidad luminosa de la superficie, plantando semillas a diferentes profundidades del suelo. Los resultados indican que no hay diferencias en el fotoblastismo negativo entre las poblaciones de Chile y California. Una significativa variación a través del rango altitudinal de California sugiere la existencia de diferenciación genética en la región nativa, sin embargo, la ausencia de diferencias a través del rango altitudinal de Chile sugiere conservatismo del rasgo a escala local. La germinación de semillas fue cero en la superficie del suelo y se incrementó cuando las semillas fueron experimentalmente enterradas, sugiriendo que el fotoblastismo negativo es inhibido. Tres posibles explicaciones son entregadas para explicar el patrón de establecimiento de E. californica a pesar de poseer fotoblastismo negativo. Este es un rasgo bastante especialista, relacionado con climas mediterráneos y no explica por sí solo la invasibilidad descrita para esta especie. De todas formas, es claro que más estudios son necesarios para dilucidar el valor adaptativo de este atributo fisiológico

    Psychometric characteristics of the Spanish version of instruments to measure neck pain disability

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    Background: The NDI, COM and NPQ are evaluation instruments for disability due to NP. There was no Spanish version of NDI or COM for which psychometric characteristics were known. The objectives of this study were to translate and culturally adapt the Spanish version of the Neck Disability Index Questionnaire (NDI), and the Core Outcome Measure (COM), to validate its use in Spanish speaking patients with non-specific neck pain (NP), and to compare their psychometric characteristics with those of the Spanish version of the Northwick Pain Questionnaire (NPQ). Methods: Translation/re-translation of the English versions of the NDI and the COM was done blindly and independently by a multidisciplinary team. The study was done in 9 primary care Centers and 12 specialty services from 9 regions in Spain, with 221 acute, subacute and chronic patients who visited their physician for NP: 54 in the pilot phase and 167 in the validation phase. Neck pain (VAS), referred pain (VAS), disability (NDI, COM and NPQ), catastrophizing (CSQ) and quality of life (SF-12) were measured on their first visit and 14 days later. Patients' self-assessment was used as the external criterion for pain and disability. In the pilot phase, patients' understanding of each item in the NDI and COM was assessed, and on day 1 test-retest reliability was estimated by giving a second NDI and COM in which the name of the questionnaires and the order of the items had been changed. Results: Comprehensibility of NDI and COM were good. Minutes needed to fill out the questionnaires [median, (P25, P75)]: NDI. 4 (2.2, 10.0), COM: 2.1 (1.0, 4.9). Reliability: [ICC, (95%CI)]: NDI: 0.88 (0.80, 0.93). COM: 0.85 (0.75,0.91). Sensitivity to change: Effect size for patients having worsened, not changed and improved between days 1 and 15, according to the external criterion for disability: NDI: -0.24, 0.15, 0.66; NPQ: -0.14, 0.06, 0.67; COM: 0.05, 0.19, 0.92. Validity: Results of NDI, NPQ and COM were consistent with the external criterion for disability, whereas only those from NDI were consistent with the one for pain. Correlations with VAS, CSQ and SF-12 were similar for NDI and NPQ (absolute values between 0.36 and 0.50 on day 1, between 0.38 and 0.70 on day 15), and slightly lower for COM (between 0.36 and 0.48 on day 1, and between 0.33 and 0.61 on day 15). Correlation between NDI and NPQ: r = 0.84 on day 1, r = 0.91 on day 15. Correlation between COM and NPQ: r = 0.63 on day 1, r = 0.71 on day 15. Conclusion: Although most psychometric characteristics of NDI, NPQ and COM are similar, those from the latter one are worse and its use may lead to patients' evolution seeming more positive than it actually is. NDI seems to be the best instrument for measuring NP-related disability, since its results are the most consistent with patient's assessment of their own clinical status and evolution. It takes two more minutes to answer the NDI than to answer the COM, but it can be reliably filled out by the patient without assistance

    CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative

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    Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

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    We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median z0.03z\sim 0.03). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between z0.6z\sim 0.6 and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July
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