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1.
Integr Org Biol ; 5(1): obad025, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37521144

RESUMEN

Evidence suggests that hurricanes can influence the evolution of organisms, with phenotypic traits involved in adhesion, such as the toepads of arboreal lizards, being particularly susceptible to natural selection imposed by hurricanes. To investigate this idea, we quantified trait variation before and after Hurricanes Irma and Maria (2017) in forest and urban populations of the Puerto Rican lizard Anolis cristatellus. We found that the hurricanes affected toe morphology differently between forest and urban sites. In particular, toepads of the forefeet were longer and narrower in forest, but wider in urban populations, compared to pre-hurricane measures. Toepads of the hind feet were larger in area following the hurricanes. Fore and rear toes increased in length following the hurricane. There were no changes in the number of lamellae scales or lamellae spacing, but lamellae 6-11 of the forefeet shifted proximally following the hurricane. We also measured clinging performance and toe shape. We found that toepad area and toe lengths were stronger predictors of adhesive forces than toepad shape. Our results highlight an interaction between urbanization and hurricanes, demonstrating the importance to consider how urban species will respond to extreme weather events. Additionally, our different results for fore and rear feet highlight the importance of evaluating both of these traits when measuring the morphological response to hurricanes in arboreal lizards.


La evidencia sugiere que los huracanes pueden influir en la evolución de los organismos, rasgos fenotípicos como las almohadillas distales de los lagartos arbóreos, son particularmente susceptibles a la selección natural impuesta por los huracanes. Para investigar esta idea, cuantificamos la variación de las almohadillas distales antes y después de los huracanes Irma y María (2017) en poblaciones de bosques y urbanas de las lagartijas puertorriqueña Anolis cristatellus. Encontramos que los cambios morfológicos luego de los huracanes variaron entre las poblaciones de bosque y urbanas. Para las poblaciones de bosque, las almohadillas de las patas delanteras eran más largas y estrechas luego de las tormentas. Por el contrario, las almohadillas delanteras de las poblaciones urbanas fueron más anchas luego de los huracanes. Las almohadillas de los pies traseros tenían un área más grande en todas las poblaciones luego de los huracanes. Los dedos delanteros y traseros aumentaron de longitud después del huracán. No hubo cambios en el número de escamas en las almohadillas distales ni en el ancho de estas escamas, pero las escamas 6­11 de las patas delanteras se desplazaron proximalmente después del huracán. También medimos las fuerzas adhesivas producida por las almohadillas distales para contrastar con la morfología de los dedos. Encontramos que el área de las almohadillas distales y la longitud de los dedos fueron los predictores más fuertes de las fuerzas adhesivas. Nuestros resultados destacan una interacción entre la urbanización y los huracanes, lo que demuestra la importancia de considerar cómo responderán las especies urbanas a los eventos climáticos extremos. Además, nuestros diferentes resultados para las patas delanteras y traseras resaltan la importancia de evaluar ambos rasgos al medir la respuesta morfológica a los huracanes en lagartijas arbóreos.

3.
Ecology ; 98(2): 412-424, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27861787

RESUMEN

Predation is considered to be an important factor structuring natural communities. However, it is often difficult to determine how it may influence long-term, broad-scale, diversity patterns, particularly in diverse tropical systems. Biological introductions can provide powerful insight to test the sustained consequences of predation in natural communities, if pre-introduction data are available. Half a century ago, Zaret and Paine demonstrated strong and immediate community-level effects following the introduction of a novel apex predator (peacock bass, Cichla monoculus) into Lake Gatun, Panama. To test for long-term changes associated with this predator introduction, we followed up on their classic study by replicating historical sampling methods and examining changes in the littoral fish community at two sites in Lake Gatun 45 years post-introduction. To broaden our inference, we complemented this temporal comparison with a spatial analysis, wherein we compared the fish communities from two lakes with and one lake without peacock bass. Comparisons with historical data revealed that the peacock bass remains the most abundant predator in Lake Gatun. Furthermore, the collapse of the littoral prey community observed immediately following the invasion has been sustained over the past 45 years. The mean abundance of native littoral fish is now 96% lower than it was prior to the introduction. Diversity (rarefied species richness) declined by 64% post-introduction, and some native species appear to have been locally extirpated. We observed a similar pattern across invaded and uninvaded lakes: the mean abundance of native fishes was 5-40 times lower in lakes with (Gatun, Alajuela) relative to the lake without peacock bass (Bayano). In particular, small-bodied native fishes (Characidae, Peociliidae), which are common prey of the peacock bass, were more than two orders of magnitude (307 times) less abundant in Gatun and one order of magnitude (28 times) less abundant in Alajuela than in Bayano. However, total native fish diversity did not differ significantly across lakes, suggesting that while many native species have declined in abundance, few have been completely extirpated. Introduced predators can have strong effects on community structure and functional diversity, even in highly diverse tropical communities, and these effects can persist over multiple decades.


Asunto(s)
Ecosistema , Peces , Cadena Alimentaria , Conducta Predatoria , Animales , Lagos , Panamá
4.
J Evol Biol ; 27(6): 1093-104, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24750315

RESUMEN

Adaptive radiation can be strongly influenced by interspecific competition for resources, which can lead to diverse outcomes ranging from competitive exclusion to character displacement. In each case, sympatric species are expected to evolve into distinct ecological niches, such as different food types, yet this expectation is not always met when such species are examined in nature. The most common hypotheses to account for the coexistence of species with substantial diet overlap rest on temporal variation in niches (often diets). Yet spatial variation in niche overlap might also be important, pointing to the need for spatiotemporal analyses of diet and diet overlap between closely related species persisting in sympatry. We here perform such an analysis by characterizing the diets of, and diet overlap among, four sympatric Darwin's ground finch species at three sites and over 5 years on a single Galápagos island (Santa Cruz). We find that the different species have broadly similar and overlapping diets - they are to some extent generalists and opportunists - yet we also find that each species retains some 'private' resources for which their morphologies are best suited. Importantly, use of these private resources increased considerably, and diet overlap decreased accordingly, when the availability of preferred shared foods, such as arthropods, was reduced during drought conditions. Spatial variation in food resources was also important. These results together suggest that the ground finches are 'imperfect generalists' that use overlapping resources under benign conditions (in space or time), but then retreat to resources for which they are best adapted during periods of food limitation. These conditions likely promote local and regional coexistence.


Asunto(s)
Adaptación Fisiológica , Dieta , Conducta Alimentaria , Pinzones/fisiología , Animales , Evolución Biológica , Conducta Competitiva , Ecuador , Pinzones/anatomía & histología , Dinámica Poblacional , Simpatría
5.
Med. cután. ibero-lat.-am ; 40(1): 3-10, ene.-feb. 2012. ilus
Artículo en Español | IBECS | ID: ibc-103001

RESUMEN

Las células madre tienen tres características comunes: la autorrenovación, la indiferenciación y la derivación a cualquier célula madura, éstas son el patrimonio (en el caso de las célula madre adultas) con el que cuenta un individuo para regenerar las células senescentes a lo largo de la vida. Las células madre pueden regenerar tejidos en individuos compatibles de la misma especie. El termino célula madre en tecnología cosmética hace referencia principalmente a sustancias extraídas de células madre de origen vegetal, ricas en polifenoles tales como el resveratrol, y luteolina o péptidos capaces de activar los genes de las sirtuinas NAD dependientes, que producen de acetilación del ADN que permiten la compactación de la cromatina (AU)


Stem cells has three common characteristics: self-renewal, differentiation and derivation of any mature cell, these are the assets (in the case of adult stem cell) with which an individual has to regenerate senescent cells along life. Stem cells can regenerate tissue compatible individuals of the same species. In Cosmetic technology the term stem cell refers mainly to stem cells extracted from substances of vegetable origin, rich in polyphenols such as resveratrol, and luteolin or peptides able to activate the genes of the NAD-dependent sirtuins, which produce deacetylation that allow the compaction of chromatin (AU)


Asunto(s)
Humanos , Rejuvenecimiento , Cosméticos/uso terapéutico , Células Madre/clasificación , Polifenoles/farmacocinética , Luteolina/farmacocinética , Sirtuinas/genética , Cromatina , Células Madre Totipotentes , Células Madre Multipotentes , Células Madre Pluripotentes
6.
Rev. colomb. ciencias quim. farm ; 37(1): 18-32, Jan. 2008. ilus, tab
Artículo en Español | LILACS | ID: lil-636140

RESUMEN

El Sistema de Clasificación Biofarmacéutica (SCB), publicado por Gordon Amidon y cols. en 1995, se basa en un sólido fundamento científico para clasificar un fármaco considerando los parámetros de solubilidad y permeabilidad, factores estrechamente relacionados con el proceso de absorción, y plantea como objetivo, la posibilidad de establecer correlaciones in vitro-in vivo que permitan sustituir los ensayos realizados en humanos por ensayos de disolución in vitro, de acuerdo con la clasificación obtenida para el fármaco. Actualmente la aplicación del SCB está enfocada a los estudios de bioequivalencia para demostrar intercambio de medicamentos, presentados en forma sólida de liberación inmediata, de administración peroral y al aseguramiento de que los cambios realizados durante el escalonamiento o en las formulaciones o procesos de éstos, una vez aprobados, no tengan incidencia en su comportamiento in vivo. La proyección de la aplicación del SCB se está dando hacia su implantación como herramienta en el desarrollo de nuevos fármacos, en el diseño y desarrollo de medicamentos y en la posibilidad de bioexenciones para los sistemas de liberación controlada.


The Biopharmaceutics Classification System (BCS), published in 1995 by Gordon Amidon and coworkers, is proposed based on recognizing the underlying process that is controlling the drug absorption rate and extent, namely, drug solubility and intestinal membrane permeability, classifying a drug according to this. Its objective is the possibility to set standards for in vitro drug dissolution testing methodology which will correlate with the in vivo process, avoiding human studies. The BCS can be used to classify drugs and set standards for scale-up and post-approval changes to show that the efficacy has not been altered, as well as standards for in vitro/in vivo correlation for bioequivalence studies, for solid oral immediate release products. About this, exists discusses for further potential applications of the BCS in the development of new drugs and drug products and in the possibility of biowaivers for controlled-release products.

7.
Water Sci Technol ; 45(9): 149-56, 2002.
Artículo en Inglés | MEDLINE | ID: mdl-12079097

RESUMEN

The transferability of parameters for non-point source pollution models to other watersheds, especially those in remote areas without enough data for calibration, is a major problem in diffuse pollution modeling. A water quality component was developed for WATFLOOD (a flood forecast hydrological model) to deal with sediment and nutrient transport. The model uses a distributed group response unit approach for water quantity and quality modeling. Runoff, sediment yield and soluble nutrient concentrations are calculated separately for each land cover class, weighted by area and then routed downstream. The distributed approach for the water quality model for diffuse pollution in agricultural watersheds is described in this paper. Integrating the model with data extracted using GIS technology (Geographical Information Systems) for a local watershed, the model is calibrated for the hydrologic response and validated for the water quality component. With the connection to GIS and the group response unit approach used in this paper, model portability increases substantially, which will improve non-point source modeling at the watershed scale level.


Asunto(s)
Sistemas de Información Geográfica , Modelos Teóricos , Contaminantes del Agua/análisis , Agricultura , Calibración , Lluvia , Movimientos del Agua
8.
Gynecol Oncol ; 82(3): 532-7, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11520151

RESUMEN

OBJECTIVE: The Gynecologic Oncology Group (GOG) has demonstrated that age, tumor grade, and size and number of residual lesions after primary cytoreductive surgery are significant prognostic factors in advanced ovarian carcinoma. Recent studies have reported numerous other clinical features as having prognostic value. We sought to identify the independent prognostic factors for survival in a cohort of patients with advanced ovarian cancer. METHODS: We performed a retrospective chart review of all patients with stage III and IV ovarian carcinoma who received their primary treatment at our institution between 1987 and 1994. RESULTS: A total of 295 patients were identified, 282 of whom were evaluable. Of these 282 patients, 214 (76%) have died of disease or other causes. The median follow-up is 32 months (range: 1-139). Eighteen factors were evaluated for prognostic significance. Significant factors in univariate analysis included patient age, gravidity (0 vs > 0), parity (0 vs > 0), preoperative albumin level, preoperative total protein level, ascites (presence vs absence), disease stage (IIIA/IIIB vs IIIC vs IV), number of residual lesions (< or =20 vs >20), and diameter of largest residual tumor nodule (< or = 1 cm vs 1-2 cm vs > 2 cm). However, on multivariate analysis, only patient age (P < 0.001), ascites (P = 0.001), and size of residual disease (P = 0.005) retained prognostic significance. Substage of disease was of borderline significance (P = 0.086). CONCLUSION: Although numerous clinical variables have recently been reported to have prognostic value in advanced ovarian carcinoma, only patient age, presence or absence of ascites, and diameter of the largest residual tumor nodule proved to be of statistical significance in our analysis.


Asunto(s)
Neoplasias Ováricas/patología , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carboplatino/administración & dosificación , Cisplatino/administración & dosificación , Ciclofosfamida/administración & dosificación , Células Epiteliales/patología , Femenino , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Ováricas/mortalidad , Neoplasias Ováricas/terapia , Paclitaxel/administración & dosificación , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del Tratamiento
9.
Gynecol Oncol ; 81(3): 485-9, 2001 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11371143

RESUMEN

OBJECTIVE: Anemia requiring red blood cell (RBC) transfusion is common in ovarian cancer (OC) patients receiving post-debulking surgery chemotherapy. Erythropoietin use has been shown to decrease transfusion requirements in patients receiving chemotherapy. We sought to identify pretreatment risk factors that could identify patients at increased risk for requiring RBC transfusion during first-line treatment for ovarian cancer. METHODS: One hundred seventy-five consecutive patients who received chemotherapy with either carboplatin-paclitaxel or cisplatin-paclitaxel following debulking surgery for epithelial OC from 1993 to 1996 were identified. No patient received erythropoietin. Patient characteristics recorded included: age, stage, prechemotherapy hemoglobin, nadir hemoglobin, number of cycles and doses of chemotherapy received. The outcome was requiring RBC transfusion. Independent predictors of requiring RBC transfusion were identified using multivariate analyses. RESULTS: Median age of the cohort was 62 years (range, 28-86). Seventy-one and four-tenths percent had FIGO stage III/IV disease. Median prechemotherapy hemoglobin was 11 g/dL (range, 7.1-15.4); median nadir hemoglobin was 9.3 g/dL (range, 6.6-11.1). One hundred nineteen (66%) patients received cisplatin-paclitaxel, and 61 (34%) received carboplatin-paclitaxel. Of 175 patients, 31 (18%, 95% CI = 12-23%) required RBC transfusion. Independent risk factors for RBC transfusion were prechemotherapy hemoglobin <10 g/dL (P < 0.01, odds ratio = 3.78, 95% CI = 1.52-9.44) and carboplatin-paclitaxel versus cisplatin-paclitaxel treatment (P = 0.01, odds ratio = 3.14, 95% CI = 1.27-7.76). Of 175 patients, 40 (22.8%) had a prechemotherapy hemoglobin <10 g/dL. Fifty percent of patients with prechemotherapy hemoglobin <10 g/dL who received carboplatin-paclitaxel required RBC transfusion, compared with 7.7% of patients with hemoglobin >10 g/dL who received cisplatin-paclitaxel. CONCLUSION: Ovarian cancer patients frequently require RBC transfusion during postdebulking platinum-paclitaxel chemotherapy. Patients with prechemotherapy hemoglobin <10 g/dL and those receiving carboplatin-paclitaxel are at increased risk of requiring RBC transfusion. Early initiation of erythropoietin use in such patients may reduce transfusion needs.


Asunto(s)
Anemia/etiología , Anemia/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Transfusión de Eritrocitos , Neoplasias Ováricas/sangre , Neoplasias Ováricas/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Anemia/inducido químicamente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carboplatino/administración & dosificación , Carboplatino/efectos adversos , Cisplatino/administración & dosificación , Cisplatino/efectos adversos , Estudios de Cohortes , Terapia Combinada , Femenino , Hemoglobinas/metabolismo , Humanos , Modelos Logísticos , Persona de Mediana Edad , Neoplasias Ováricas/cirugía , Paclitaxel/administración & dosificación , Paclitaxel/efectos adversos , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Factores de Riesgo
10.
Water Res ; 35(4): 997-1007, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11235895

RESUMEN

A distributed water quality model for nonpoint source pollution modeling in agricultural watersheds is described in this paper. A water quality component was developed for WATFLOOD (a flood forecast hydrological model) to deal with sediment and nutrient transport. The model uses a distributed group response unit approach for water quantity and quality modeling. Runoff, sediment yield and soluble nutrient concentrations are calculated separately for each land cover class, weighted by area and then routed downstream. With data extracted using Geographical Information Systems (GIS) technology for a local watershed, the model is calibrated for the hydrologic response and validated for the water quality component. The transferability of model parameters to other watersheds, especially those in remote areas without enough data for calibration, is a major problem in diffuse modeling. With the connection to GIS and the group response unit approach used in this paper, model portability increases substantially, which will improve nonpoint source modeling at the watershed-scale level.


Asunto(s)
Contaminación del Agua , Agua/normas , Agua Dulce/análisis , Sedimentos Geológicos/análisis , Modelos Teóricos , Ontario , Control de Calidad , Agua/análisis
11.
Biometrics ; 54(3): 1165-75, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9840971

RESUMEN

In Markov regression models with time series data, we apply asymptomatic results to obtain the quasi-score, quasi-Wald, and quasi-likelihood ratio tests for assessing model adequacy. Based on limited simulation studies, we show that these three test statistics, particularly the quasi-score test, perform reasonably well in small samples. In addition, we apply these tests to the mean-shift outlier model to examine outliers. The usefulness of these tests is demonstrated via the analysis of three practical examples.


Asunto(s)
Biometría/métodos , Cadenas de Markov , Modelos Estadísticos , Adulto , Animales , Tasa de Natalidad , California/epidemiología , Femenino , Haplorrinos , Neoplasias de Cabeza y Cuello/mortalidad , Humanos , Funciones de Verosimilitud , Edad Materna , Embarazo , Embarazo de Alto Riesgo , Análisis de Regresión , Transmisión Sináptica , Factores de Tiempo
12.
Arch Latinoam Nutr ; 39(3): 405-18, 1989 Sep.
Artículo en Español | MEDLINE | ID: mdl-2562331

RESUMEN

Samples of cotyledons and whole black beans (Phaseolus vulgaris), Tamazulapa variety were stored during six weeks at 37 degrees C and 90% relative humidity to establish chemical and physical changes which occur during storage, and to determine the role played by the seed coat in the hard-to-cook phenomenon. After the storage period, samples of whole beans were divided in two subsamples, with and without the seed coat. These two samples and the cotyledons were analyzed for cooking time, water absorption, dietary fiber, tannic acid, soluble pectins and phytic acid. Cooking time of the whole beans increased from 99 to more than 480 minutes in the six-weeks period; for the cotyledons this value increased from 45 to 111 minutes. Cooking time of the dehulled bean, stored as whole bean, increased from 45 to 111 minutes. Cooking time of the dehulled bean, stored as whole bean, increased from 45 to 103 minutes. Water absorption in the whole beans and the cotyledons decreased, although in the cotyledons it was higher, due perhaps to the great absorption capacity to the seed coat. No changes were observed in the dietary fiber content of the cotyledons nor in the beans dehulled after storage. However, in the whole grains neutro-detergent fiber decreased, while acid detergent fiber, cellulose and lignin did not present significant changes. On the other hand, soluble pectates decreased in the whole bean and in the cotyledons; nevertheless the tannin content (as tannic acid) decreased only in the whole beans (from 3.28 to 1.64 mg/g). The data obtained suggest that the seed coat plays a significant role in the hard-to-cook process of hardening of the bean, before and during storage.


Asunto(s)
Fibras de la Dieta/análisis , Fabaceae/fisiología , Manipulación de Alimentos , Proteínas de Vegetales Comestibles/análisis , Plantas Medicinales , Manipulación de Alimentos/métodos , Calor
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