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Ecuador has a high diversity of orchids, but little is known about levels of genetic diversity for the great majority of species. Understanding how orchids might adapt to changes is crucial as deforestation and fragmentation of forest ecosystems threaten the survival of many epiphytic orchids that depend on other species, such as fungi and their host trees, for germination, growth, and establishment. Overcollection and the illegal trade are also major concerns for the survival of wild populations of orchids. Despite increasing awareness, effective interventions are often limited by a lack of data concerning the impacts that overexploitation might have. To fill this gap, we tested the effects of overcollection in the genetic diversity and structure of Masdevallia rosea, a narrow distributed epiphytic orchid historically collected in Ecuador, in comparison with the widely distributed Pleurothallis lilijae. Genotyping based on AFLPs showed reduced levels of diversity in wild populations but most especially in the overcollected, M. rosea. Overall, genetic admixture was high in P. lilijae segregating populations by altitude levels while fewer genetic groups were found in M. rosea. Genetic differentiation was low in both species. A spatial genetic structure was found in P. lilijae depending on altitude levels, while no spatial genetic structure was found in M. rosea. These results suggest different scenarios for the two species: while gene flow over long distance is possible in P. lilijae, the same seems to be unlikely in M. rosea possibly due to the low levels of individuals in the known populations. In situ and ex situ conservation strategies should be applied to protect the genetic pool in these epiphytic orchid species, and to promote the connectivity between wild populations. Adopting measures to reduce overexploitation and to understand the impacts of harvesting in wild populations are necessary to strengthen the legal trade of orchids.
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Ecossistema , Orchidaceae , Humanos , Equador , Florestas , Orchidaceae/genética , Variação GenéticaRESUMO
OBJECTIVE: To evaluate the aspirin resistance prevalence in patients with previous ischemic cerebrovascular disease undergoing aspirin therapy for secondary prevention. MATERIALS AND METHODS: Three hundred fifty patients presenting ischemic strokes and 100 healthy controls under aspirin treatment were evaluated using the optic platelet aggregation test. RESULTS: Aspirin resistance was found in 7.4% of the patients with ischemic stroke and 4% of controls. Aspirin resistance was associated with stroke recurrence in univariate analysis (p = 0.004). Aspirin resistance was not associated with smoking, diabetes, or hypercholesterolemia. CONCLUSION: Aspirin resistance is present in Colombian patients with ischemic stroke as well as in healthy controls.
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RESUMEN El envejecimiento en general, y el cutáneo, en particular, es un proceso deletéreo y universal. El envejecimiento cutáneo se puede dividir en envejecimiento cronológico y fotoenvejecimiento, este último se activa a través del daño en la piel humana, atribuible a la exposición repetida a los rayos ultravioleta (UV) de la luz solar. Se ha considerado que los ácidos grasos derivados del aceite de pescado (omega 3) están asociados con la fotoprotección de la piel. El objetivo de este trabajo es describir los efectos del omega 3 como medicamento antienvejecimiento en la población de adultos mayores. Para ello, se realizó una revisión bibliográfica de artículos publicados entre enero de 2010 y junio de 2020, en Pubmed y Google Scholar. La literatura disponible evidencia el efecto y beneficio de estos ácidos grasos en el proceso de envejecimiento, los cuales constituyen terapias clínicas a nivel dermatológico y en áreas de cirugía plástica. Su uso ejerce un efecto positivo sobre el proceso de envejecimiento en diferentes órganos, mediante la acción frente al estrés oxidativo.
ABSTRACT Aging in general, and skin aging in particular, is a deleterious and universal process. Skin aging can be divided into chronological aging and photoaging, the latter being activated through damage to human skin, attributable to repeated exposure to ultraviolet (UV) rays from sunlight. Fatty acids derived from fish oil (omega 3) have been considered to be associated with photoprotection of the skin. The objective of this work is to describe the effects of omega 3 as an anti-aging drug in the elderly population. A bibliographic review of articles published between January 2010 and June 2020, in Pubmed and Google Scholar, was carried out. The available literature shows the effect and benefit of these fatty acids in the aging process, which constitute clinical therapies at the dermatological level and in areas of plastic surgery. Its use has a positive effect on the aging process in different organs, through action against oxidative stress.
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Epiphytic vascular plants comprise an essential part of the tropical flora and are a key component for ecosystem functioning. Some recent studies have used a network approach to investigate the interaction of epiphytes with host phorophytes at the community level. However, knowledge on commensalistic epiphyte-phorophyte network structure still lags behind with regard to other biotic interaction networks. Our goal was to provide a more complete overall perspective on commensalistic epiphyte-phorophyte interaction and its placement with respect to other better studied mutualistic interactions. We hypothesized that the intensity of the fitness effect of the different types of biotic interactions would determine the degree of specialization of the interacting organisms. Thus, commensalistic epiphyte-phorophyte interactions would have lower specialization than mutualistic interactions. We compiled and analysed the structural properties (nestedness, network specialization and modularity) of 12 commensalistic epiphyte-phorophyte networks and compared them with the same metrics to 11 ant-myrmecophyte, 86 pollination and 13 seed dispersal mutualistic networks. Epiphyte-phorophyte networks were nested and modular with regard to the corresponding null models and had greater nestedness than mutualistic networks, whereas specialization and modularity were significantly lower. Commensalistic epiphyte-phorophyte networks of interactions are both nested and modular, and hence, are structured in a similar way to most other types of networks that involve co-evolutionary interactions. Nevertheless, the nature and intensity of the ecological processes involved in the generation of these patterns is likely to differ. The lower values of modularity in commensalistic epiphyte-phorophyte networks are probably due to the low levels of specialization and the lack of co-evolutionary processes between the interacting partners.
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Introducción. La hipertensión arterial es una enfermedad multifactorial influenciada por componentes genéticos y ambientales, cuya prevalencia varía entre grupos étnicos. Se han llevado a cabo numerosos estudios en genes de sistemas reguladores de la presión arterial, como el sistema renina-angiotensinaaldosterona, el sistema nervioso simpático, los factores endoteliales, y el balance de sodio, mostrando resultados incongruentes entre poblaciones. Objetivos. Evaluar el efecto de variantes en los genes AGT , AGTR1 , ACE , ADRB2 , DRD1 , ADD1 , ADD2 , ATP2B1 , TBXA2R y PTGS2 y del componente ancestral individual, sobre la hipertensión arterial y las cifras de presión arterial en una muestra de población antioqueña. Materiales y métodos. Se genotipificaron 107 casos y 253 controles para 12 variantes en los genes AGT , AGTR1 , ACE , ADRB2 , DRD1 , ADD1 , ADD2 , ATP2B1 , TBXA2R y PTGS2 , y para 20 marcadores informativos de ascendencia. Se evaluó la asociación de los polimorfismos y sus interacciones, y de la composición genética ancestral con hipertensión y cifras de presión arterial. Resultados. Los genes ADD2 , rs4852706 (OR=3,0; p=0,023); DRD1 , rs686 (OR=0,38; p=0,012) y ADRB2 , rs1042718 (OR=10,0; p=0,008); y combinaciones genotípicas de DRD1 con AGTR1 ; de AGT con ADD1 ; y de ADD1 con ATP2B1 y PTGS2 , se asociaron con hipertensión arterial. El componente ancestral amerindio se asoció con disminución en la presión arterial diastólica. Conclusiones. Variantes en los genes ADD2 , DRD1 , ADRB2 , AGTR1 , AGT , ADD1 , ATP2B1 y PTGS2 , individualmente o en su interacción, se encuentran asociadas con hipertensión. El componente ancestral amerindio tiene un efecto sobre las cifras de presión arterial.
Introduction: Hypertension is a multifactorial disease influenced by genetic and environmental components, with its prevalence varying across ethnic groups. Manifold studies on blood pressure regulatory system genes have been carried out -such as the renin-angiotensin-aldosterone system, the sympathetic nervous system, endothelial factor, and sodium balance-, but the results yielded were inconsistent among populations. Objectives: To evaluate the effect of both variants in genes AGT, AGTR1, ACE, ADRB2, DRD1, ADD1, ADD2, ATP2B1, TBXA2R PTGS2, and the result of the individual ancestry component on hypertension and blood pressure levels among population in Antioquia. Methods and materials: 107 cases and 253 controls were genotyped for 12 variants on genes AGT, AGTR1, ACE, ADRB2, DRD1, ADD1, ADD2, ATP2B1, TBXA2R y PTGS2, and for 20 ancestry informative markers. The association of polymorphisms and their interactions, and the association of ancestral genetic composition with hypertension and blood pressure levels were examined. Results: Genes ADD2, rs4852706 (OR=3.0; p=0.023); DRD1, rs686 (OR=0.38; p=0.012) and ADRB2, rs1042718 (OR=10.0; p=0.008); as well as genotypic combinations of DRD1 and AGTR1; AGT and ADD1; and ADD1 to ATP2B1 and PTGS2 were associated to hypertension. The Amerindian ancestry component was associated to some decrease in diastolic blood pressure. Conclusion: Variants on genes ADD2, DRD1, ADRB2, AGTR1, AGT, ADD1, ATP2B1 and PTGS2 individually or interacting, are associated to hypertension. The Amerindian ancestry component has an effect on blood pressure.
Assuntos
Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hipertensão/genética , Angiotensinogênio/genética , Pressão Sanguínea/genética , Proteínas de Ligação a Calmodulina/genética , Colômbia , /genética , Peptidil Dipeptidase A/genética , ATPases Transportadoras de Cálcio da Membrana Plasmática/genética , Receptor Tipo 1 de Angiotensina/genética , /genética , Receptores de Dopamina D1/genética , /genética , Fatores de RiscoRESUMO
INTRODUCTION: Hypertension is a multifactorial disease influenced by genetic and environmental components, with its prevalence varying across ethnic groups. Manifold studies on blood pressure regulatory system genes have been carried out -such as the renin-angiotensin-aldosterone system, the sympathetic nervous system, endothelial factor, and sodium balance-, but the results yielded were inconsistent among populations. OBJECTIVES: To evaluate the effect of both variants in genes AGT, AGTR1, ACE, ADRB2, DRD1, ADD1, ADD2, ATP2B1, TBXA2R PTGS2, and the result of the individual ancestry component on hypertension and blood pressure levels among population in Antioquia. METHODS AND MATERIALS: 107 cases and 253 controls were genotyped for 12 variants on genes AGT, AGTR1, ACE, ADRB2, DRD1, ADD1, ADD2, ATP2B1, TBXA2R y PTGS2, and for 20 ancestry informative markers. The association of polymorphisms and their interactions, and the association of ancestral genetic composition with hypertension and blood pressure levels were examined. RESULTS: Genes ADD2, rs4852706 (OR=3.0; p=0.023); DRD1, rs686 (OR=0.38; p=0.012) and ADRB2, rs1042718 (OR=10.0; p=0.008); as well as genotypic combinations of DRD1 and AGTR1; AGT and ADD1; and ADD1 to ATP2B1 and PTGS2 were associated to hypertension. The Amerindian ancestry component was associated to some decrease in diastolic blood pressure. CONCLUSION: Variants on genes ADD2, DRD1, ADRB2, AGTR1, AGT, ADD1, ATP2B1 and PTGS2 individually or interacting, are associated to hypertension. The Amerindian ancestry component has an effect on blood pressure.
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Hipertensão/genética , Adulto , Angiotensinogênio/genética , Pressão Sanguínea/genética , Proteínas de Ligação a Calmodulina/genética , Colômbia , Ciclo-Oxigenase 2/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peptidil Dipeptidase A/genética , ATPases Transportadoras de Cálcio da Membrana Plasmática/genética , Receptor Tipo 1 de Angiotensina/genética , Receptores Adrenérgicos beta 2/genética , Receptores de Dopamina D1/genética , Receptores de Tromboxano A2 e Prostaglandina H2/genética , Fatores de RiscoRESUMO
El estudio de las biotecnologías usadas con fines reproductivos en caninos, constituye uno de los principalespuntos de estudio investigativo para el campo de la Medicina Veterinaria y la Zootecnia en los últimos años 28. Conel objetivo de evaluar el efecto de tres diferentes concentraciones de glicerol sobre el semen canino sometido aprocesos de criopreservación, se obtuvieron por medio de manipulación manual, 12 muestras seminales de machos de la raza labrador, clínicamente sanos y sometidos a las mismas condiciones de manejo. Cada muestra se dividió en cuatro tratamientos (T1: control, T2: 4%, T3: 6% y T4: 8% de glicerol); a los cuales se les evaluó el volumen,pH, movilidad, concentración, morfología y vitalidad, respectivamente. Luego en el análisis pos descongelaciónse determinaron las diferencias seminales y se estableció su relación con la concentración del crioprotector. De los resultados obtenidos en este proyecto se encontraron diferencias significativas entre las variables morfología, mortalidad y concentración, igualmente se estableció que los tratamientos T2 (4% de glicerol) y T3 (6% de glicerol) presentaron mejores resultados para la congelación de semen en caninos.
The study of biotechnology used in canines for reproductive purposes, is a of the principal research study points tothe area of Veterinary Medicine in last years28. In the objective to evaluate the effect of three different concentrationsof glycerol on canine semen, to subjected cryo-preservation process, were obtained using manual manipulation, 12semen samples of male Labrador clinically healthy and subject to the same driving conditions. Each sample was divided in four treatments (T1: control, T2: 4%, T3: T4 6% and 8% glycerol), to which they evaluated the volume, pH, motility, concentration, morphology and vitality, respectively. Then in the analysis were determined after thawing seminal differences and its relationship to the concentration of cryoprotectant. From the results obtained in this project are significant differences between the variables morphology, mortality and concentration, also establishedthat T2 (4% glycerol) and T3 (6% glycerol) provide better results for freezing semen canines.
O estudo da biotecnologia utilizada em cães para fins reprodutivos constitui um dos principais pontos de pesquisapara o campo da medicina veterinária e zootecnia nos últimos anos28. Com o objetivo de se avaliar o efeito de trêsdiferentes concentrações de glicerol sobre sêmen canino submetidos a processos crioconservação, foram obtidaspor meio de manipulação manual 12 amostras de sêmen de Labrador macho, clinicamente saudáveis e submetidasàs mesmas condições de manejo. Cada amostra foi dividida em quatro tratamentos (T1: controle, T2: 4%, T3: 6% e T4: 8% de glicerol), os quais foram avaliados quanto ao volume, pH, mobilidade, concentração, morfologia evitalidade, respectivamente. Nas análises pós descongelamento foram determinadas as diferenças entre os semens e se estabeleceu uma relação com a concentração do crioprotetor. A partir dos resultados obtidos neste trabalho foram encontradas diferenças significativas entre a variável morfologia, mortalidade e concentração e também ficou estabelecido que T2 (4% de glicerol) e T3 (6% de glicerol) apresentaram os melhores resultados para o congelamento de sêmen em caninos.
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Animais , Criopreservação/métodos , Criopreservação/veterinária , Preservação do Sêmen/estatística & dados numéricos , Preservação do Sêmen/métodos , Preservação do Sêmen/veterinária , Congelamento , SêmenRESUMO
Heteroptera is a worldwide distributed group of insects inhabiting both terrestrial and aquatic habitats and has an important ecological role. A survey of aquatic and semiaquatic Heteroptera from Cuba is provided based on literature reports and field collections. General data on species geographical distribution are given, along with altitude and collection season. Representatives of 86 species and morphospecies of the infraorders Dipsocoromorpha, Leptopodomorpha, Gerromorpha and Nepomorpha are listed, distributed in 35 genera and 16 families were found. Based on distributional data, a preference for habitats of stagnant water or slow current and lower altitudes is inferred. Fifteen species are distributed throughout the entire island. A higher species diversity was found in the Eastern sector, with 53 species (61.63%), 16 of which (18.60%) are confined to this area. The strongest biological similarity was found between Eastern and Western sectors (25%), and the weakest between Western and Central sectors (14%). Rev. Biol. Trop. 58 (3): 897-907. Epub 2010 September 01.
Heteroptera es un grupo de insectos que se distribuyen en todo el mundo, viven en ambientes terrestres y acuáticos, en los que tienen un papel ecológico muy importante. Mediante la literatura y colecciones en el campo se estudiaron los Heterópteros acuáticos y semiacuáticos de Cuba, junto con datos sobre la distribución geográfica de las especies, altitud y estaciones de colecta. Se enumeran representantes de 86 especies y morfospecies de los infraórdenes Dipsocoromorpha, Leptopodomorpha, Gerromorpha y Nepomorpha, con un total de 35 géneros y 16 familias. Los datos de distribución muestran una preferencia por los ambientes de aguas lentas o estancadas y áreas de baja altitud. Quince especies se distribuyen en toda la isla; el sector Oriental es el mejor representado, con 53 especies (61.63%), 16 de ellas (18.60%) confinadas a este sector. La similitud biológica más fuerte se encontró entre los sectores oriental y occidental (25%) y la más débil entre los sectores occidental y central (14%).
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Animais , Ecossistema , Heterópteros/classificação , Cuba , Água Doce , GeografiaRESUMO
Heteroptera is a worldwide distributed group of insects inhabiting both terrestrial and aquatic habitats and has an important ecological role. A survey of aquatic and semiaquatic Heteroptera from Cuba is provided based on literature reports and field collections. General data on species geographical distribution are given, along with altitude and collection season. Representatives of 86 species and morphospecies of the infraorders Dipsocoromorpha, Leptopodomorpha, Gerromorpha and Nepomorpha are listed, distributed in 35 genera and 16 families were found. Based on distributional data, a preference for habitats of stagnant water or slow current and lower altitudes is inferred. Fifteen species are distributed throughout the entire island. A higher species diversity was found in the Eastern sector, with 53 species (61.63%), 16 of which (18.60%) are confined to this area. The strongest biological similarity was found between Eastern and Western sectors (25%), and the weakest between Western and Central sectors (14%).
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Ecossistema , Heterópteros/classificação , Animais , Cuba , Água Doce , GeografiaRESUMO
Bromus setifolius var. pictus (Hook) Skottsb., B. setifolius var. setifolius Presl. and B.setifolius var. brevifolius Ness are three native Patagonian taxa in the section Pnigma Dumort of the genus Bromus L. AFLP and RAPD analysis, in conjunction with genetic distance measurements and statistical techniques, revealed variation within this group and indicated that B. setifolius var. brevifolius was closely related to B. setifolius var. pictus, with both taxa being more distantly related to B. setifolius var. setifolius. Cytogenetic analysis confirmed the chromosomal number of B. setifolius var. pictus (2n = 70) and B. setifolius var. setifolius (2n = 28) and showed for the first time that B. setifolius var. brevifolius had 2n = 70. The combination of molecular genetic and cytogenetic evidence supported a species status for two of the three taxa and suggested hypotheses for the evolutionary origin of these complex taxa. Species status was also indicated for B. setifolius var. setifolius. Based on these findings, we suggest that B. setifolius var. pictus be referred to as B. pictus Hook var. pictus, and B. setifolius var brevifolius as B. pictus Hook var brevifolius. The correlation between AFLP diversity and variation in ecological parameters suggested that this marker system could be used to assess breeding progress and to monitor the domestication of Patagonian Bromus species for agronomic use.
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Bromus setifolius var. pictus (Hook) Skottsb., B. setifolius var. setifolius Presl. and B. setifolius var. brevifolius Ness are three native Patagonian taxa in the section Pnigma Dumort of the genus Bromus L. AFLP and RAPD analysis, in conjunction with genetic distance measurements and statistical techniques, revealed variation within this group and indicated that B. setifolius var. brevifolius was closely related to B. setifolius var. pictus, with both taxa being more distantly related to B. setifolius var. setifolius. Cytogenetic analysis confirmed the chromosomal number of B. setifolius var. pictus (2n = 70) and B. setifolius var. setifolius (2n = 28) and showed for the first time that B. setifolius var. brevifolius had 2n = 70. The combination of molecular genetic and cytogenetic evidence supported a species status for two of the three taxa and suggested hypotheses for the evolutionary origin of these complex taxa. Species status was also indicated for B. setifolius var. setifolius. Based on these findings, we suggest that B. setifolius var. pictus be referred to as B. pictus Hook var. pictus, and B. setifolius var brevifolius as B. pictus Hook var brevifolius. The correlation between AFLP diversity and variation in ecological parameters suggested that this marker system could be used to assess breeding progress and to monitor the domestication of Patagonian Bromus species for agronomic use.
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Según la hipótesis de la anhedonia el valor placentero de la comida está determinado por la actividad de dopamina en el cerebro. La evidencia empírica muestra que los agonistas y antagonistas a la dopamina (e.g., metilfenidato y haloperidol, respectivamente) disminuyen la conducta operante mantenida con reforzamiento positivo. Se utilizó la ley generalizada de igualación (Baum, 1974) para evaluar efectos de estas drogas en la motricidad y motivación del organismo por la comida. Treinta y dos ratas buscaron alimento en una situación de elección donde la razón de reforzamiento que proporcionaban dos alternativas cambia diariamente. Los resultados confirmaron que las drogas no impiden la rápida adaptación de las ratas a los cambios dinámicos en las contingencias de reforzamiento. Se evidenció un incremento en la sensibilidad de las razones de respuestas a los cambios en las razones de los reforzadores. La alternativa de mayor demanda motriz para el organismo mostró una reducción en el número de respuestas, sugiriendo efectos de las drogas en la motricidad del organismo.
The anhedonia hypothesis maintains that pleasure for food-reward is determined by dopamine activity in the brain. The cumulative body of empiricalevidence shows that dopamine agonists and antagonists (e.g., Methylphenidateand Haloperidol, respectively) decrease operant behavior maintained by positive reinforcement. The present study used the generalized matching law (Baum, 1974) to assess effects of these drugs on the motor system and the organisms motivation for food reinforcers. Thirty-two rats searched for food in a choice situation where the reinforcer ratio provided by two alternativeschanged everyday. The results confirmed that the drugs do not impede the rats rapid adaptation to dynamic changes in the contingencies of reinforcement. Preference favored with more responses the alternative associated to the higher probability of reinforcement, showing an increment in sensitivity of behavior ratio to changes in food ratios. The alternative demanding the higher motor requirement showed a decrement in the number of responses, suggesting effects of the drugs in the organisms motor system.
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Pesquisa , Agonistas de Dopamina , Antagonistas de Dopamina , Dopamina , Dopamina beta-HidroxilaseRESUMO
A history of the study of the order Ephemeroptera in Cuba since the XIX century, when the first species were discovered, and an analysis of the current list of families, genera and species is presented. Endemism and the geographical distribution of the species in Cuba are commented upon, as well as the relations between the biogeographical areas of the country. Finally, some suggestions are given in connection with future research on the order Ephemeroptera in Cuba.
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Insetos , Animais , Cuba , DemografiaRESUMO
Se realiza un repaso histórico al estudio del orden Ephemeroptera en Cuba desde principios del siglo XIX, en que fueron descubiertas las primeras especies, y un análisis de la composición actualmente conocida de la fauna cubana, por familias, géneros y especies. Se explica la distribución geográfica de las especies dentro de la isla de Cuba, así como el endemismo, llevándose a cabo un estudio comparativo entre las regiones biogeográficas reconocidas para el país. Por último se ofrecen recomendaciones sobre las líneas de trabajo a abordar en este orden en Cuba.
A history of the study of the order Ephemeroptera in Cuba since the XIX century, when the first species were discovered, and an analysis of the current list of families, genera and species is presented. Endemism and the geographical distribution of the species in Cuba are commented upon, as well as the relations between the biogeographical areas of the country. Finally, some suggestions are given in connection with future research on the order Ephemeroptera in Cuba.
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Animais , Insetos , Cuba , DemografiaRESUMO
Outcome deta research from international surveys on college students report that alcohol problems in colleges are an emergent health concern. This paper describes the development and evaluation of a stepped-care cognitive-behavioral motivational model for college students with alcohol problems, that includes three specific treatment programs, "BASICS", "GSC", and "SRP", which are part of the state-of-the-art cognitive-behavioral motivational treatments to address a broad spectrum of drinking problems available in centers for alcohol problems at the National Autonomous University of México. A modified version of the stepped-care approach and strategies of treatment-client matching were used to select patients for the treatment programs. This article describes the model and its programs and the initial outcome data from a study designed to evaluate its efficacy on a group of college students that address a broad spectrum of alcohol problems and its future perspectives.
Resultados de encuestas internacionales en estudiantes universitarios documentan que los problemas de alcohol constituyen un problema emergente de salud pública. Se describe el desarrollo y evaluación de un modelo cognitivo-conductual motivacional de atención escalonada para estudiantes universitarios con problemas de alcohol, que incluye tres programas de tratamiento, "BASICS", "GSC" y "SRP", que forman parte del estado del arte de los tratamientos cognitivo-conductuales y motivacionales para el abordaje de un amplio espectro de problemas de alcohol, disponibles en centros y programas de la UNAM. Se empleó una versión modificada del enfoque de atención escalonada y una combinación de estrategias de igualación "cliente-tratamiento", para la asignación de participantes a tratamientos específicos. Se describe el modelo y los resultados obtenidos en un estudio diseñado para evaluar su eficacia con un grupo de estudiantes universitarios que cubren un amplio espectro de problemas de alcohol.
RESUMO
La sensibilidad al reforzamiento aumenta con los incrementos en el requisito de respuesta de cambio. Este hallazgo, documentado con conducta de elección estacionaria, ocurre en programas concurrentes de intervalo variable (IV-IV) independientes y en los que son dependientes uno del otro para la asignación de los reforzadores. Este estudio evaluó la generalidad de este hallazgo con conducta de elección en transición. En dos palancas, la razón de reforzadores cambió siete veces en una misma sesión, modelando un ambiente dinámico. Doce ratas respondieron a dos palancas para obtener comida. Para cambiar de la palanca de menor a la de mayor probabilidad de reforzamiento, una palanca de cambio incrementó el requisito de respuestas en nueve condiciones de ocho respuestas cada una; sólo una respuesta se requirió para regresar a la palanca de menor probabilidad de reforzamiento. El Experimento 1 (elección forzada) arregló reforzadores dependientes en dos programas de intervalo aleatorio y el Experimento 2 (elección libre) los arregló independientes. La elección se ajustó rápidamente a los cambios dinámicos en la razón de reforzadores. En el Experimento 1 la sensibilidad al reforzamiento aumentó con los incrementos en el requisito de respuesta de cambio, pero en el Experimento 2 ésta disminuyó.
Sensitivity to reinforcement increases with increasing changeover response requirements. This result has beendocumented with stationary choice in concurrent variable interval (VI-VI) independent schedules of reinforcement, as well as, in concurrent VI-VI schedules where the availability of reinforcers is dependently scheduled. The present studyassessed the generality of this finding with choice in transition. Within sessions the ratio of reinforcers changed seventimes in two levers, modeling a dynamic environment. Twelve rats responded to the levers for food reinforcers. To switch from the lean to the rich lever, a third changeover-lever increased the response requirement in nine steps of 8 responses each; only one response was required to switch from the rich to the lean lever. In Experiment 1 (forced choice) the reinforcers were dependently scheduled in the levers, but in Experiment 2 (free choice) the reinforcers were independently arranged by the schedules. Choice adjusted rapidly to the dynamic changes in the ratio of reinforcers. In Experiment 1 sensitivity to reinforcement increased, but in Experiment 2 it decreased with increasing changeoverresponse requirement.
Assuntos
Animais de Laboratório , Ratos/psicologiaRESUMO
OBJECTIVE: The present study was undertaken to assess the impact, effectiveness and safety of a monophasic hormone replacement treatment (HRT) for continuous use with regards to the clinical effects, bleeding patterns and lipid profile of menopausal women in four Latin American countries. DESIGN: Three hundred and six postmenopausal women with natural menopause and uterus present were recruited. This was a multicentre prospective, clinical trial; the participating countries were Brazil (BR), Colombia (CO), Mexico (MX) and Argentina (AR). The study period was 12 months. The HRT regime was formulated in tablets containing 2 mg estradiol E2 and 1mg norethisterone acetate (NETA); one visit every 3 months was solicited. METHODS: HRT was given as one tablet every day without interruption for 1 year. Climacteric complaints, side-effects, reason for discontinuation, bleeding patterns, lipid profile at baseline and 12 months of treatment were documented. RESULTS: There were no significant differences between the four populations on clinical measurements. Thirty-four women discontinued, 13 for bleeding problems. The five most common side-effects were mastalgia, bleeding problems, headache, pelvic pain and nausea. 44.8% of women experienced scanty vaginal bleeding during the first 3 months of therapy. Ninety seven percent of women had amenorrhea at the end of the study in MX, BR and AR, and 100% in CO. Body weight was constant during the study, and no correlation was found between body weight and total days with bleeding. The Kupperman index score was used to evaluate the climacteric complaints, and the score decreased from a mean of 25.4 to 5.1 at 12-months visit. Total cholesterol levels were significantly reduced in BR and CO (P < 0.05) between baseline and the final sample; serum triglycerides remained unchanged, HDL-cholesterol was significantly increased in MX (P < 0.05), and LDL-cholesterol was significantly reduced in CO (P < 0.05). The results of this 1-year study emphasize that a continuous combined HRT regimen with 2 mg E2/1 mg NETA is an attractive alternative for postmenopausal women who are at least 1 year after their menopause and optimally 2 years after their menopause. Although the combination of 2 mg E2 with 1 mg NETA in a continuous combined therapy scheme has been in use in the Nordic countries for over a decade and in Latin America for the last 6 years, there have been no previous published reports on its effectivity in Latin American women. This publication reports the experience in a group of 306 Latin American women, and it is the first Latin American publication with this formulation.
Assuntos
Anticoncepcionais Orais Sintéticos/uso terapêutico , Estradiol/uso terapêutico , Terapia de Reposição de Estrogênios , Menopausa , Noretindrona/análogos & derivados , Noretindrona/uso terapêutico , Administração Oral , Adulto , Ansiedade/tratamento farmacológico , Anticoncepcionais Orais Sintéticos/efeitos adversos , Depressão/tratamento farmacológico , Tontura/tratamento farmacológico , Estradiol/efeitos adversos , Terapia de Reposição de Estrogênios/efeitos adversos , Feminino , Cefaleia/tratamento farmacológico , Frequência Cardíaca/efeitos dos fármacos , Fogachos/tratamento farmacológico , Humanos , América Latina , Lipídeos/sangue , Pessoa de Meia-Idade , Debilidade Muscular/tratamento farmacológico , Noretindrona/efeitos adversos , Acetato de Noretindrona , Parestesia/tratamento farmacológico , Estudos ProspectivosRESUMO
Chromosome in situ hybridization (FISH and GISH) is a powerful tool for determining the chromosomal location of specific sequences and for analysing genome organization and evolution. Tricepiro (2n = 6x = 42) is a synthetic cereal obtained by G. Covas in Argentina (1972), which crosses hexaploid triticale (2n = 6x = 42) and octoploid Trigopiro (2n = 8x = 56). Several years of breeding produced a forage crop with valuable characteristics from Secale, Triticum, and Thinopyrum. The aim of this work is to analyse the real genomic constitution of this important synthetic crop. In situ hybridization using total DNA of Secale, Triticum, and Thinopyrum as a probe (GISH) labelled with biotin and (or) digoxigenin showed that tricepiro is composed of 14 rye chromosomes and 28 wheat chromosomes. Small zones of introgression of Thinopyrum on wheat chromosomes were detected. The FISH using the rye repetitive DNA probe pSc 119.2 labelled with biotin let us characterize the seven pairs of rye chromosomes. Moreover, several wheat chromosomes belonging to A and B genomes were distinguished. Therefore, tricepiro is a synthetic hexaploid (2n = 6x = 42) being AABBRR in its genomic composition, with zones of introgression of Thinopyrum in the A genome of wheat.
Assuntos
Cromossomos de Plantas , Grão Comestível/genética , Genoma de Planta , Hibridização in Situ Fluorescente , Mitose/genéticaRESUMO
Estudios recientes indican que la elección no necesita alcanzar un estado estable para mostrar sensibilidad al reforzamiento. Esta idea se puso a prueba en una situación de elección que manipuló el requisito de cambio. Los parámetros de la ley de igualación generalizada (Baum, 1974) se usaron para evaluar cambios en preferencia ocasionados por un incremento en una razón fija que sirvió como requisito de cambio. Para impedir que la ejecución concurrente alcanzara un estado estable, de una sesión a otra se manipuló la razón de reforzamiento que proporcionaban dos palancas de cambio (27:1, 9:1, 3:1, 1:1, 1:3, 1:9 y 1:27). En diferentes condiciones la razón fija para el cambio tomó valores de 1, 4, 8, 16 y 32 respuestas. Los resultados mostraron efectos locales del reforzamiento sobre la elección, de un reforzador a otro las distribuciones de respuestas favorecieron la palanca asociada con la mayor probabilidad de reforzamiento. La sensibilidad al reforzamiento no aumentó con el incremento en el requisito de respuesta de cambio, pero el parámetro s se estabilizó en niveles superiores a 1.0 con la experiencia de las ratas en este medio ambiente
Assuntos
Animais , Comportamento de EscolhaRESUMO
La osteoporosis (OP) es una alteración sistémica del esqueleto, la cual afecta principalmente a mujeres de mayor edad. La presente investigación fue diseñada para el estudio de algunos factores de riesgo para OP, en una población específica. En un estudio de casos y controles se incluyeron 367 mujeres con edades entre 30 y 80 años, mientras acudían para tamizaje de OP mediante DEXA-DMO. De ellas, 193 tenían diagnóstico de OP y 174 tenían DEXA normal. Para calcular la probabilidad de tener OP, se diseñó un modelo estadístico, el cual incluía edad, años en menopausia e índice de Masa Corporal (IMC). Se encontró que las mujeres con OP tenían mayor edad, más años en menopausia y menor IMC. Los antecedentes familiares para OP, el hábito de fumar, el ejercicio, la ingesta de calcio y el uso de TRH, no fueron significantes. Se concluye que existen factores de riesgo con mayor impacto sobre el desarrollo de la OP. Se necesitan mayores estudios de población para definir la validez de estos hallazgos