Las orquídeas de la Reserva de la Biosfera Torres del Paine: La necesidad de implementar monitoreo de especies y planificación ecoturística para la conservación de la biodiversidad

The orchid flora of Torres del Paine Biosphere Reserve (TPBR) is described based on botanical surveys, photographicalrecords and herbarium collections carried out by the authors. This list comprises 3 genera and 9 species: Chloraea chica,Chloraea leptopetala, Chloraea magellanica, Codonorchis lessonii, Gavilea araucana, Gavilea gladysiae, Gavilealittoralis, Gavilea lutea and Gavilea supralabellata. G. gladysiae is a new record for this protected area and the firstalbino aberrant phenotype for flowers of Chl. magellanica is reported. A description of the species including key fordetermination, morphology, habitats, local abundances, flowering phenology and photographs is provided. The speciesrichness here reported represents ca. 35% of orchids occurring in the Chilean temperate-austral floristic regions and 75%of the species described for the Magallanes Region, putting the Torres del Paine Biosphere Reserve as one of the mostrepresentative protected areas for this taxonomical group in the region. Based on our results we addressed the need ofestablishing monitoring programs for orchids and promote them as flagship species in ecotourism planning in order toenhance species valuation and encourage biodiversity conservation.  Se describen las orquídeas de la Reserva de la Biosfera Torres del Paine sobre la base de exploraciones botánicas, registrosfotográficos y colecciones de herbario llevadas a cabo por los autores. Esta lista comprende 3 géneros y 9 especies: Chloraeachica, Chloraea leptopetala, Chloraea magellanica, Codonorchis lessonii, Gavilea araucana, Gavilea gladysiae, Gavilealittoralis, Gavilea lutea y Gavilea supralabellata. G. gladysiae es un registro nuevo para esta área protegida y se reporta elprimer fenotipo aberrante de flores albinas de Chl. magellanica. Se provee de una descripción de las especies que incluyemorfología, habitats, abundancias locales, fenología de floración y fotografías. La riqueza de especies aquí reportadarepresenta cerca del 35% de las orquídeas que se distribuyen en las regiones florísticas Templada-Austral y el 75% de lasespecies descritas para la Región de Magallanes, colocando a la Reserva de la Biosfera Torres del Paine como una de lasáreas protegidas más representativas para este grupo taxonómico en Chile. Basados en nuestros resultados recalcamosla necesidad de establecer programas de monitoreo para las orquídeas y promoverlas como especies emblemáticas enplanificación ecoturística para así incrementar la valoración de las especies y reforzar la conservación de la biodiversidad

Colour appearance in led lighting

The paper shows a comparative study of colour comparison between white LED lamps and conventional ones (incandescent and compact fluorescent). The LED lamps used were a model designed by the direct replaces of halogen incandescent lamps. The technology used for white light generation was based on short waves emitter chips and secondary emission. As result of the experience, significant object colour coordinates displacements in LEDs lighting were observed. As it was predictable from LEDs spectral distribution, orange – red colours were poorly reproduced. However, the subjective experience did not show a remarkable preference to the conventional light sources. Furthermore, several observers qualified the objects under LEDs light as “more naturals”

Colour appearance in led lighting

The paper shows a comparative study of colour comparison between white LED lamps and conventional ones (incandescent and compact fluorescent). The LED lamps used were a model designed by the direct replaces of halogen incandescent lamps. The technology used for white light generation was based on short waves emitter chips and secondary emission. As result of the experience, significant object colour coordinates displacements in LEDs lighting were observed. As it was predictable from LEDs spectral distribution, orange – red colours were poorly reproduced. However, the subjective experience did not show a remarkable preference to the conventional light sources. Furthermore, several observers qualified the objects under LEDs light as “more naturals”.Facultad de IngenieríaComisión de Investigaciones Científicas de la provincia de Buenos Aire

\u3cem\u3eHelicobacter pylori\u3c/em\u3e infection in Havana, Cuba. Prevalence and \u3cem\u3ecagA\u3c/em\u3e status of the strains

There is a great paucity of information about Helicobacter pylori infection in the countries of the Caribbean basin. Almost no studies have been performed to determine the prevalence, antibiotic resistance or virulence factors of the bacterium. To measure the prevalence of H. pylori infection among patients attending endoscopy in three clinics in Havana, Cuba, to evaluate clarithromycin resistance, and to determine the cagA status of the strains obtained. Endoscopy was performed and biopsies were obtained from 117 successive patients attending the Institute of Oncology, the Institute of Gastroenterology, and the Calixto Garcia Hospital in Havana, Cuba. Biopsies were maintained at –70 ºC before being cultured on three different media (two selective and one non-selective) and incubated for 7 days at 37 °C under a microaerobic atmosphere. The presence of H. pylori was identified by oxidase, catalase and urease activities. DNA was extracted, and PCR was performed with primers H2761676 which amplify a 397 bp fragment of the cagA gene. Clarithromycin susceptibility was measured by the gel diffusion method. The diagnoses of patients were: 1 gastric carcinoma; 19 duodenal ulcers; 8 gastric ulcers; and 89 non-ulcer dyspepsia, including (62) gastritis, (9) hiatal hernia,(2) biliary reflux, (1) gastric polyps, and (15) no abnormality. Among the 117 biopsies tested, 83 were H. pylori positive (70.9%). The cagA status determined for 35 cases gave a positive result in 31 cases (88.5%). Only 3% of the strains were resistant to clarithromycin. The prevalence of Helicobacter pylori infection in the symptomatic population of La Habana is the same as reported for other developing countries. Most strains were cagA positive and are likely harbour the cag pathogenicity island. The low resistance to clarithromycin in the strains studied probably reflects the low degree of use of the antibiotic in this population

Colour appearance in led lighting

The paper shows a comparative study of colour comparison between white LED lamps and conventional ones (incandescent and compact fluorescent). The LED lamps used were a model designed by the direct replaces of halogen incandescent lamps. The technology used for white light generation was based on short waves emitter chips and secondary emission. As result of the experience, significant object colour coordinates displacements in LEDs lighting were observed. As it was predictable from LEDs spectral distribution, orange – red colours were poorly reproduced. However, the subjective experience did not show a remarkable preference to the conventional light sources. Furthermore, several observers qualified the objects under LEDs light as “more naturals”.Facultad de IngenieríaComisión de Investigaciones Científicas de la provincia de Buenos Aire

Amyloid peptides ABri and ADan show differential neurotoxicity in transgenic Drosophila models of familial British and Danish dementia

BACKGROUND: Familial British and Familial Danish dementias (FBD and FDD, respectively) are associated with mutations in the BRI2 gene. Processing of the mutated BRI2 protein leads to the accumulation in the brain of the 34-mer amyloid Bri (ABri) and amyloid Dan (ADan) peptides, accompanied by neurofibrillary tangles. Recently, transgenic mice successfully reproduced different aspects of FDD, while modeling of FBD in vivo has been more difficult. In this work we have modeled FBD and FDD in Drosophila and tested the hypothesis that ABri and ADan are differentially neurotoxic. RESULTS: By using site-directed insertion, we generated transgenic lines carrying ABri, ADan, Bri2-23 (the normal product of wild-type BRI2 processing) and amyloid-β (Aβ) 1-42 as a well-characterized neurotoxic peptide, alone or with a His-tag. Therefore, we avoided random insertion effects and were able to compare levels of accumulation accurately. Peptides were expressed with the GAL4-Upstream Activating Sequence (UAS) system using specific drivers. Despite low levels of expression, toxicity in the eye was characterized by mild disorganization of ommatidia and amyloid peptides accumulation. The highest toxicity was seen for ADan, followed by Aβ42 and ABri. Pan-neuronal expression in the CNS revealed an age-dependent toxicity of amyloid peptides as determined by the ability of flies to climb in a geotaxis paradigm when compared to Bri2-23. This effect was stronger for ADan, detected at 7 days post-eclosion, and followed by ABri and Aβ42, whose toxicity became evident after 15 and 21 days, respectively. Histological analysis showed mild vacuolization and thioflavine-S-negative deposits of amyloid peptides. In contrast, the over-expression of amyloid peptides in the specific subset of lateral neurons that control circadian locomotor activity showed no toxicity. CONCLUSIONS: Our results support the differential neurotoxicity of ADan and ABri in the Drosophila eye and CNS at low expression levels. Such differences may be partially attributed to rates of aggregation and accumulation. In the CNS, both peptides appear to be more neurotoxic than wild-type Aβ42. These Drosophila models will allow a systematic and unambiguous comparison of differences and similarities in the mechanisms of toxicity of diverse amyloid peptides associated with dementia.Fil: Marcora, Maria Silvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires; Argentina. Fundación Instituto Leloir; ArgentinaFil: Fernandez Gamba, Agata Claudia. Fundación Instituto Leloir; ArgentinaFil: Avendaño, Luz A. Fundación Instituto Leloir; ArgentinaFil: Rotondaro, Cecilia. Fundación Instituto Leloir; ArgentinaFil: Podhajcer, Osvaldo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires; Argentina. Fundación Instituto Leloir; ArgentinaFil: Vidal, Rubén. Indiana University School of Medicine. Indiana Alzheimer Disease Center. Department of Pathology and Laboratory Medicine; Estados UnidosFil: Morelli, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires; Argentina. Fundación Instituto Leloir; ArgentinaFil: Ceriani, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires; Argentina. Fundación Instituto Leloir; ArgentinaFil: Castaño, Eduardo Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquimicas de Buenos Aires; Argentina. Fundación Instituto Leloir; Argentin

Clinical and Genetic Spectrum of Stargardt Disease in Argentinean Patients

Purpose: To describe the clinical and molecular spectrum of Stargardt disease (STGD) in a cohort of Argentinean patients. Methods: This retrospective study included 132 subjects comprising 95 probands clinically diagnosed with STGD and relatives from 16 of them. Targeted next-generation sequencing of the coding and splicing regions of ABCA4 and other phenocopying genes (ELOVL4, PROM1, and CNGB3) was performed in 97 STGD patients. Results: We found two or more disease-causing variants in the ABCA4 gene in 69/95 (73%) probands, a single ABCA4 variant in 9/95 (9.5%) probands, and no ABCA4 variants in 17/95 (18%) probands. The final analysis identified 173 variants in ABCA4. Seventy-nine ABCA4 variants were unique, of which nine were novel. No significant findings were seen in the other evaluated genes. Conclusion: This study describes the phenotypic and genetic features of STGD1 in an Argentinean cohort. The mutations p.(Gly1961Glu) and p.(Arg1129Leu) were the most frequent, representing almost 20% of the mutated alleles. We also expanded the ABCA4 mutational spectrum with nine novel disease-causing variants, of which eight might be associated with South American natives.Fil: Mena, Marcela Daniela C. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Moresco, Angélica A.. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Vidal, Sofía H.. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Aguilar Cortes, Diana Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Obregon, María G.. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Fandiño, Adriana Cristina. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Sendoya, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Llera, Andrea Sabina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Podhajcer, Osvaldo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

Estudio preliminar de la biodiversidad vegetal terrestre en el Estero Walker (Región de Aysén, Chile): utilizando líneas base de proyectos de inversión

Using plant sociological data from the baseline of an aquaculture project the flora and terrestrial vegetation in five sectors of the banks of the Estero Walker, located in the western Chilean Patagonia is studied. According to a preliminary catalog the flora consisting of 68 native species, which dominate Dicotyledons, Monocotyledons and Ferns, latter indicate high atmosferical humidity. The absence of annual and biennial plants confirms the presence of a cold and wet weather, the absence of weed indicate the little human intervention. The low floristic similarity between the sectors studied is conditioned by exposure and a wide range of habitats. The presence, coverage and importance of plant species were analyzed in orderly vegetation table, the most important were woody. The orderly vegetation table shows 4 groups which were confirmed by multivariate statistical analysis, three communities: coihue forest of Chiloé (Luzuriago marginatae- Nothofagetum nitidae), scrub and taique tepú (Desfontainio fulgense-Tepualietum estipulariae) and pulvinate bog (Schoeno andini-Lepidothamnietum fonkii), first was described in 2004 and the last two are proposed as new associations. A final group represented in one vegetation sample correspond to a swamp which could also represent a new community which a provisionally name Libertio chilensis-Leptocarpetum chilensis is proposed. For the plant association Desfontainio fulgense- Tepualietum stipulariae one subassociation Desfontainio fulgense-Tepualietum stipulariae Campsidietosum valdivianae is proposed. We discuss the syntaxonomy of these plant communities and confirm the usefulness of the baselines to know the flora and vegetation of remote locations.Utilizando datos tomados con metodología fitosociológica en la línea base de un proyecto de acuicultura se estudiaron la flora y la vegetación terrestre en 5 sectores de las riberas del Estero Walker, ubicado en la Patagonia occidental chilena. Se construyó un catálogo preliminar de la flora que consta de 68 especies nativas, en las cuales dominan Dicotiledóneas, Monocotiledóneas y Helechos, estos últimos indican alta humedad atmosférica en el lugar. La ausencia de plantas anuales y bienales confirma la presencia de un clima húmedo frío, y la de malezas, la escasa intervención antrópica. La baja similitud florística entre los sectores estudiados está condicionada por la exposición y una variada oferta de hábitats. La presencia, cobertura e importancia de las especies de la flora se analizó en la tabla de vegetación ordenada, las más importantes fueron leñosas. La tabla de vegetación ordenada entregó 4 grupos que fueron confirmados por análisis estadísticos multivariados, correspondientes a 3 comunidades: bosque de coihue de Chiloé (Luzuriago marginatae-Nothofagetum nitidae), matorral de tepu (Desfontainio fulgense-Tepualietum estipulariae) y turbera pulvinada (Schoeno andini-Lepidothamnietum fonkii), la primera descrita en el 2004 y las dos últimas se proponen como asociaciones nuevas. Un último grupo representado en un solo censo de vegetación correspondería a un pantano de canutillo, el cual podría representar también una comunidad nueva para la cual se propone en forma provisional el nombre de Libertio chilensis-Leptocarpetum chilensis. Para la asociación Desfontainio fulgense-Tepualietum stipulariae se propone una subasociación nueva Desfontainio fulgense-Tepualietum stipulariae Campsidietosum valdivianae. Se discute la sintaxonomía de estas comunidades y se confirma la utilidad de las líneas base para conocer la flora y vegetación de lugares remotos

Utilizando la metodología fitosociológica para diferenciar hábitats: un ejemplo con especies chilenas de Schinus (Anacardiaceae) en la Región de Aisén, Chile

Habitats of Schinus patagonicus and Schinus marchandii in the Chilean Patagonia were studied, in order to determinethe plant communities into these species growing and the primary or secondary character of them, to help establishthe conservation status of the two species. We worked with phytosociological methods to characterize floristic andvegetationaly the communities. The vegetation table is ordered with traditional methods, using differential species andwith multivariate statistical classification and ordination methods. The initial vegetation table provided 68 plant speciesof which 26 are introduced weed. In the biological spectrum dominated hemicryptophytes and minor phanerophytes andtherophytes. Traditional management of the vegetation table separated the Mutisio-Schinetum patagonicae (“clavel delaire” and “molle” scrub) and Colliguajo-Schinetum marchandii (“duraznillo” and “laura” steppe scrub) new associations that are described. Comparison of these two communities established that they are floristically very different and thattheir phytosociological affinity is low, the first is a secondary scrub community that replaces the deciduous patagonic“lenga” forest and the “ñire” scrub degraded by human action and the second, a primary steppe community. The abundantpresence of Mulinum spinosum differentiates degraded stages of these two communities specially the first. The secondarycharacter of the “clavel del aire” and “molle” community confirms the more aggressive and competitive position of Schinuspatagonicus, which ensures their survival as a species, but the primary character and the small size of the scrub of “laura”and “duraznillo” scrub also areal reduction of Schinus marchandii indicate that the conservation status of the latter speciesin Chile is poor.Se estudiaron los hábitats de Schinus patagonicus y Schinus marchandii en la Patagonia chilena, con el propósito dedeterminar las comunidades vegetales en que crecen y el carácter primario o secundario de ellas, para ayudar a establecerel estado de conservación de las dos especies. Se trabajó con metodología fitosociológica para caracterizar florística yvegetacionalmente las comunidades. La tabla de vegetación se ordenó con métodos tradicionales, utilizando especiesdiferenciales y estadísticos multivariables de clasificación y ordenación. La tabla fitosociológica inicial presentó 68 especiesvegetales siendo 26 de ellas malezas introducidas. En el espectro biológico predominaron hemicriptófitos y con menorimportancia, fanerófitos y terófitos. La ordenación tradicional separó las asociaciones Mutisio-Schinetum patagonicae(matorral de clavel del aire y molle) y Colliguajo-Schinetum marchandii (matorral estepario de duraznillo y laura) quese describen como nuevas. La comparación de estas dos comunidades permitió establecer que son florísticamente muydiferentes y que su afinidad fitosociológica es baja: la primera es una comunidad de matorral secundario que reemplazaal bosque de lenga y al matorral de ñire caducifolios degradados por la acción humana y la segunda, una comunidadesteparia primaria. La abundante presencia de Mulinum spinosum permite diferenciar estadios degradados para la primeray esteparios extremos para la segunda. El carácter secundario de la comunidad de clavel del aire y molle confirma la mayoragresividad y capacidad de competencia de Schinus patagonicus, lo que asegura su sobrevivencia como especie, pero elcarácter primario y el pequeño tamaño del área del matorral de duraznillo y laura, además de la reducción de tamaño deSchinus marchandii, indican que el estado de conservación de esta última especie en Chile es precario

Experimental and computational investigation of the substituent effects on the reduction of Fe³⁺ by 1,2-dihydroxybenzenes

This study reports on the kinetics of the early steps that mediate the reactions of substituted 1,2-dihydroxybenzenes (1,2-DHB) with Fe³⁺. The rate constants of the three processes identified by means of the stopped-flow technique are affected by the electron-withdrawing or electron-donating abilities of the substituent. The fastest process is assigned to the formation of a 1 : 1 complex between Fe³⁺ and the 1,2-DHB, which is accompanied by proton loss. The second process involves the inner-sphere electron transfer from the ligand to Fe³⁺ and the slowest step is related to the deprotonation of one of the oxygen atoms bonded to the metal. A reaction mechanism is proposed on the basis of the experimental data and density functional theory (DFT) calculations on mono- and bidentate species with different degrees of protonation.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada