Especies de Lepanthes (Orchidaceae) de Colombia

Las orquídeas son una de las familias de plantas más ricas en especies en el mundo y Colombia posee una gran proporción de esta diversidad, con 4000 especies estimadas en 205 géneros, siendo la subtribu Pleurothallidinae una de las más diversas en la familia, incluyendo un 15-20% de las especies de orquÌdeas (Luer 1986). Las Pleurothallidinae son un grupo de orquÌdeas neotropicales, con cerca de 4000 especies distribuidas en 29 géneros (Luer 1986), en las que se incluye el género Lepanthes. Este es el tercer género más diverso de la subtribu, después de Stelis y Pleurothallis, y está comprendido por ca. 800 especies distribuidas desde México hasta Bolivia incluyendo las Antillas (Luer 1996a). Los dos paÌses con m·s especies de Lepanthes son: Colombia con 270 (Listado TaxonÛmico) y Ecuador con 332 (Luer 2002); otros paÌses con buena diversidad son México con 60 (Salazar & Soto 1996) y Costa Rica con 95 (Pupulin 2002); en Puerto Rico se encuentran nueve (Ackerman 1995). Muchas especies de Lepanthes poseen una distribución limitada y presentan un alto grado de endemismo y algunas otras están ampliamente distribuidas. La mayoría de las especies de Lepanthes habitan los bosques nublados, donde las temperaturas son bajas y la humedad es alta

Catálogo de las orquídeas del Valle geográfico del río Cauca y su piedemonte andino bajo, Sur-occidente colombiano.

Twenty forest patches belonging to the potential domain of tropical dry forest were explored in the Cauca Valley bioregion (421,000 ha) in southwestern Colombia. Sampling was carried out from September, 2009,to October, 2010, at elevations between 930 and 1,200 m. During the field evaluations we reach 346 hours of observation distributed in 60 Km. This exploration produced the most complete list of orchids ever made in this territory, with a total of 70 species belonging to 41 genera. This figure is 112% (37 species) greater than existing records for this bioregion, and represents 1.74% of the total of orchid species reported for Colombia. Several new regional records were found, as well as at least three endemic species, probably one local extinction, and one new species for science. This figure is compared with other much smaller areas, such as the forest of Yotoco in the department of Valle del Cauca, and possible explanations for the low species richness are proposed. At the same time, a bank of digital high-resolution images of the orchid flora of the department was begun

POLLEN CARRIED BY Euglossa nigropilosa MOURE (APIDAE: EUGLOSSINAE) AT LA PLANADA NATURE RESERVE, NARIÑO, COLOMBIA

RESUMEN Las abejas Euglosinas son importantes polinizadores de plantas neotropicales de tierras bajas. Con el objetivo de determinar las principales fuentes de polen y néctar de Euglossa nigropilosa (Euglossinae), en La Reserva Natural La Planada RNLP, Nariño, Colombia, observamos su comportamiento en plantas cercanas a sus nidos durante más de 100 horas. Además, los granos de polen recolectados de las corbículas fueron recolectados de abejas arribando a los nidos y fueron identificados en el laboratorio. El polen fue preparado usando la técnica de acetólisis y caracterizado morfológicamente utilizando una serie de descriptores taxonómicos como número, posición y tipo de apertura. El polen fue identificado a nivel género incluyendo Tibouchina, Miconia y Clidemia (Melastomataceae), Physalis y Solanum (Solanaceae), y Melothria (Cucurbitaceae); esteúltimo apareció en muy baja frecuencia. La mayoría de visitas florales de E. nigropilosa para colectar polen fueron a Melastomataceae, seguidas por Solanaceae. Las fuentes de néctar de E. nigropilosa en el campo incluyen Impatiens balsamina (Balsaminaceae) y Melothria longituba. Este estudio muestra una fuerte preferencia de E. nigropilosa por fuentes de polen provenientes de floras con el síndrome de polinización por vibración. Para conservar E. nigropilosa en la naturaleza es importante proteger las plantas que ofrecen recursos vitales como polen, néctar y resinas para la construcción de sus nidos. SUMMARY Euglossinae bees are important pollinators of lowland plants in the Neotropics. With the aim of determining the main nectar and pollen sources for the Euglossinae bee Euglossa nigropilosa, at La Planada Nature Reserve LPNR, Nariño, Colombia, we observed the behaviour on plants near the nest for more than 100 hours. Additionally, pollen grains from corbicula were collected from bees arriving at their nests and identified in the laboratory. Pollen was prepared using acetolysis technique and characterized morphologically using a list of taxonomic descriptors with taxonomic value such as number, position and type of pollen aperture. The pollen genera identified included Tibouchina, Miconia and Clidemia (Melastomataceae), Physalis and Solanum (Solanaceae), and Melothria (Cucurbitaceae); this last one occurred at a very low frequency. The majority of E. nigropilosa flower visits to collect pollen were to Melastomataceae, followed by Solanaceae. The nectar plants visited by E. nigropilosa in the field included Impatiens balsamina (Balsaminaceae) and Melothria longituba. This study shows a strong preference by E. nigropilosa for pollen sources with buzz pollination syndrome. In order to preserve E. nigropilosa in the field, it is important to provide plants that offer vital resources such as pollen, nectar and resin for nest construction

Catasetum (Orchidaceae: Catasetinae) en Colombia: lista actualizada

Colombia se considera uno de los países más ricos en orquídeas, a pesar de que ha sido poco estudiado en algunas bioregiones del país. Los registros del género Catasetum corresponden entre 29 a 31 especies, sin embargo, existe un sinnúmero de equivocaciones en la identidad taxonómica interespecífica, como en el uso de sus sinónimos. Por tal motivo, el objetivo del presente trabajo es conocer la diversidad de Catasetum en Colombia. De esta manera, se realizaron salidas de campo, revisión de colecciones, literatura y herbarios. En la lista actualizada se registran 38 especies, que incluyen especies poco conocidas y confundidas como C. dejeaniorum, C. aff. juruenense, C. mooeri, C. tenebrosum y los híbridos naturales como C. aff. × apolloi, C. × dunstervillei y C. × violascens. De las cinco especies endémicas, C. blepharochilum y C. tricorne, se conocen solo de espécimen tipo, y C. lucis es exclusivo de Santander y cultivado, para C. rectangulare y C. villegasii, se realizan comentarios taxonómicos. La Amazonía y los Andes concentran la mayor diversidad y, el Caribe es la zona menos explorada. Además se incluyen los caracteres diagnósticos, rangos altitudinales, relaciones geográficas y los sinónimos utilizados en el país para algunas especies con identidad taxonómica dudosa. También, se resalta la necesidad de realizar exploraciones en zonas de vacíos de colecta,  como el Atlántico y, el Amazonas, centro de diversidad del grupo, con la finalidad de establecer futuros planes de manejo y conservación

European domestic horses originated in two holocene refugia

The role of European wild horses in horse domestication is poorly understood. While the fossil record for wild horses in Europe prior to horse domestication is scarce, there have been suggestions that wild populations from various European regions might have contributed to the gene pool of domestic horses. To distinguish between regions where domestic populations are mainly descended from local wild stock and those where horses were largely imported, we investigated patterns of genetic diversity in 24 European horse breeds typed at 12 microsatellite loci. The distribution of high levels of genetic diversity in Europe coincides with the distribution of predominantly open landscapes prior to domestication, as suggested by simulation-based vegetation reconstructions, with breeds from Iberia and the Caspian Sea region having significantly higher genetic diversity than breeds from central Europe and the UK, which were largely forested at the time the first domestic horses appear there. Our results suggest that not only the Eastern steppes, but also the Iberian Peninsula provided refugia for wild horses in the Holocene, and that the genetic contribution of these wild populations to local domestic stock may have been considerable. In contrast, the consistently low levels of diversity in central Europe and the UK suggest that domestic horses in these regions largely derive from horses that were imported from the Eastern refugium, the Iberian refugium, or both.This work was partially supported by a research studentship from the Biotechnology and Biological Sciences Research Council (BB/E527604/1) and a PhD studentship from the German Academic Exchange Service (D/07/44562) to VW, and a Leverhulme Trust project grant (F/09 757/B) to MAB. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Association between age of cannabis initiation and gray matter covariance networks in recent onset psychosis

Cannabis use during adolescence is associated with an increased risk of developing psychosis. According to a current hypothesis, this results from detrimental effects of early cannabis use on brain maturation during this vulnerable period. However, studies investigating the interaction between early cannabis use and brain structural alterations hitherto reported inconclusive findings. We investigated effects of age of cannabis initiation on psychosis using data from the multicentric Personalized Prognostic Tools for Early Psychosis Management (PRONIA) and the Cannabis Induced Psychosis (CIP) studies, yielding a total sample of 102 clinically-relevant cannabis users with recent onset psychosis. GM covariance underlies shared maturational processes. Therefore, we performed source-based morphometry analysis with spatial constraints on structural brain networks showing significant alterations in schizophrenia in a previous multisite study, thus testing associations of these networks with the age of cannabis initiation and with confounding factors. Earlier cannabis initiation was associated with more severe positive symptoms in our cohort. Greater gray matter volume (GMV) in the previously identified cerebellar schizophrenia-related network had a significant association with early cannabis use, independent of several possibly confounding factors. Moreover, GMV in the cerebellar network was associated with lower volume in another network previously associated with schizophrenia, comprising the insula, superior temporal, and inferior frontal gyrus. These findings are in line with previous investigations in healthy cannabis users, and suggest that early initiation of cannabis perturbs the developmental trajectory of certain structural brain networks in a manner imparting risk for psychosis later in life

Traces of trauma – a multivariate pattern analysis of childhood trauma, brain structure and clinical phenotypes

Background: Childhood trauma (CT) is a major yet elusive psychiatric risk factor, whose multidimensional conceptualization and heterogeneous effects on brain morphology might demand advanced mathematical modeling. Therefore, we present an unsupervised machine learning approach to characterize the clinical and neuroanatomical complexity of CT in a larger, transdiagnostic context. Methods: We used a multicenter European cohort of 1076 female and male individuals (discovery: n = 649; replication: n = 427) comprising young, minimally medicated patients with clinical high-risk states for psychosis; patients with recent-onset depression or psychosis; and healthy volunteers. We employed multivariate sparse partial least squares analysis to detect parsimonious associations between combinations of items from the Childhood Trauma Questionnaire and gray matter volume and tested their generalizability via nested cross-validation as well as via external validation. We investigated the associations of these CT signatures with state (functioning, depressivity, quality of life), trait (personality), and sociodemographic levels. Results: We discovered signatures of age-dependent sexual abuse and sex-dependent physical and sexual abuse, as well as emotional trauma, which projected onto gray matter volume patterns in prefronto-cerebellar, limbic, and sensory networks. These signatures were associated with predominantly impaired clinical state- and trait-level phenotypes, while pointing toward an interaction between sexual abuse, age, urbanicity, and education. We validated the clinical profiles for all three CT signatures in the replication sample. Conclusions: Our results suggest distinct multilayered associations between partially age- and sex-dependent patterns of CT, distributed neuroanatomical networks, and clinical profiles. Hence, our study highlights how machine learning approaches can shape future, more fine-grained CT research

Especies de <em>Lepanthes<em> (Orchidaceae) de Colombia

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