Universidad de Magallanes
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First abundance estimates of Magellanic penguin (Spheniscus magellanicus) colony at Tucker Islet
No full textThe nesting site of Magellanic penguins (Spheniscus magellanicus) at Tucker islets (54 degrees 09'S; 70 degrees 17'W), Chile, is documented and information from the first population abundance estimate on the largest islet during the beginning of chick rearing is provided. Ground-based counts yielded an estimate of 8883 (95% Confidence Intervals: 6653-11,802) burrows; however, counts of active burrows resulted in a total estimate of 2218 (95% Confidence Intervals: 1593-2840) breeding pairs. Based on the estimated total of burrows, this suggests a population decline consistent with trends for other colonies in the Magellan Strait and adjacent waters in Chile. An annual monitoring program to track population changes, breeding success, and chick and egg survival rates is required to assess the species' conservation status of the colony
Rangos de movilidad de poblaciones de cazadores-recolectores en Patagonia meridional: Hallazgos de litos discoidales en superficie
No full textSe presentan recientes hallazgos de litos discoidales en la Patagonia meridional y se revisa, en conjunto con la distribución de puntas Cueva Fell, su potencial significado en términos de los rangos de movilidad de cazadores-recolectores. Se presenta la información disponible y se evalúan las posibilidades de que en algunos casos apliquen explicaciones tiempo-transgresivas, exaptativas y otras. La evaluación del caso de la cueva Fell y sus alrededores considera el contexto de algunos de los hallazgos, así como su potencial significado en términos de interacción con otros sitios. Finalmente, se comentan los hallazgos de litos en un contexto global, sugiriendo que una hipótesis de convergencia parece más fuerte que una de origen común
Iridaea cordata lipid extract associated with the rCP01850 protein of C. pseudotuberculosis elicited a Th1 immune response in immunized sheep
No full textSheep farming contributes to the socioeconomic development of small and medium-scale livestock farmers. However, several factors can hinder successful animal production, as is the case for infectious diseases, such as the one caused by Corynebacterium pseudotuberculosis, known as caseous lymphadenitis (CLA). CLA has >90% prevalence in Brazilian herds and antibiotic treatment is not effective, consequently causing significant economic losses to farmers. Given the above, effective vaccines need to be developed to prevent this disease. This study aimed to evaluate the adjuvant activity of the lipid extract from the macroalgae Iridaea cordata as a candidate for developing an effective vaccine formulation. For such, four groups of six sheep each were inoculated with sterile 0.9% saline solution (G1), rCP01850 (G2), rCP01850 + I. cordata (G3), and rCP01850 + saponin (G4). Each sheep received two vaccine doses 30 days apart. Total IgG production levels significantly increased in experimental groups G3 and G4 on days 30, 60, and 90. On day 90, G3 showed higher total IgG production (p < 0.05) when compared to G4. When analyzing cytokine production, G3 was the only experimental group with significantly increased IFN-gamma, IL-12, TNF-alpha, and IL-10 mRNA expression levels. Our results show the vaccine formulation containing rCP01850 adjuvanted with the I. cordata lipid extract elicited a Th1 immune response in sheep, indicating I. cordata lipid extract may be a promising adjuvant for developing an effective vaccine against infection caused by C. pseudotuberculosis
Indigenous Peoples and local communities report ongoing and widespread climate change impacts on local social-ecological systems
No full textThe effects of climate change depend on specific local circumstances, posing a challenge for worldwide research to comprehensively encompass the diverse impacts on various local social-ecological systems. Here we use a place-specific but cross-culturally comparable protocol to document climate change indicators and impacts as locally experienced and analyze their distribution. We collected first-hand data in 48 sites inhabited by Indigenous Peoples and local communities and covering all climate zones and nature-dependent livelihoods. We documented 1,661 site-agreed reports of change corresponding to 369 indicators. Reports of change vary according to climate zone and livelihood activity. We provide compelling evidence that climate change impacts on Indigenous Peoples and local communities are ongoing, tangible, widespread, and affect multiple elements of their social-ecological systems. Beyond potentially informing contextualized adaptation plans, our results show that local reports could help identify economic and non-economic loss and damage related to climate change impacts suffered by Indigenous Peoples and local communities. Indigenous Peoples and local communities across climate zones and nature dependent livelihoods experience climate change impacts that affect multiple parts of their socioeconomic system, suggests an analysis of 1,661 site-agreed climate change impact reports from 48 locations
Phylogenetics of Cruckshanksia and Oreopolus (Rubiaceae) based on nuclear and plastid DNA sequences
No full textCruckshanksia Hook. & Arn. and Oreopolus Schltdl. Rubiaceae (Rubioideae - Coussareeae), endemic genera of Chile and Andean Argentina, have historically been highly taxonomically unstable. Molecular analyses have confirmed Oreopolus as the sister group of Cruckshanksia; however, the relationships among its species are still not resolved because previous studies have not considered all species of the genus and the published topologies have many unsupported nodes. For this reason, we carried out a phylogenetic study with all the species currently recognized by recent revisions, using two nuclear DNA regions and five plastid regions, to elucidate the relationships between species. In addition, the evolutionary history of the group was estimated based on divergence times, and a character reconstruction was performed. The results corroborate that Oreopolus is the sister group of Cruckshanksia. Cruckshanksia is monophyletic and composed of two principal clades. Clade I is composed of Subclade I (C. pumila and C. verticillata) associated with C. montiana; Clade II is composed of Subclade II (C. palmae and C. macrantha) and Subclade III (C. lithiophila and C. hymenodon). With 81% probability the common ancestor of the genus Cruckshanksia had petaloid appendices associated with two independent lines of evolution. The probability that the common ancestor of the Oreopolus-Cruckshanksia clade had equal calyx lobes is 50%
Differential temperature sensitivity of haploid and diploid spores of two red intertidal algae from the Magellan Strait
No full textSpores have crucial importance in the establishment and development of seaweed populations. When the spore release matches with the low tidal period, they experience an extreme variation in the environmental conditions including the temperature. In this study, we assess the photosynthetic responses and growth of haploid (tetraspores) and diploid (carpospores) spores of two Gigartinales species (Mazzaella laminarioides and Iridaea cordata) from sub-Antarctic populations when exposed to an increasing temperature. In the laboratory, freshly released spores were exposed to a temperature gradient (7 [control], 10, 15, and 20 degrees C) recreating the temperature increase experienced by these spores during typical spring tides. Germination and further growth of spores previously exposed to temperature treatments were assessed. Carpospores and tetraspores exhibited variation in their photosynthetic response (measured as effective quantum yield; Phi PSII) to temperature increase. In Mazzaella laminarioides, only carpospores exhibited a reduction in Phi PSII (by 7-24% at 15-20 degrees C), while both types of spores of Iridaea cordata were sensitive to temperature increase (12-24% of Phi PSII reduction at 10-20 degrees C). Spores previously exposed to temperature treatments and maintained at 7 degrees C and low PAR germinated and developed in germlings. In general, germlings originated from carpospores pre-treated at high temperatures showed higher growth rates. The different responses to temperature increase exhibited by haploid and diploid propagules of both species highlight their ecophysiological capacity to face high-temperature variation ensuring successful recruitment survival
IMPACTO DE LA APLICACIÓN DEL ENFOQUE BASADO EN COMPETENCIAS EN UNA UNIVERSIDAD ESTATAL CHILENA
No full textLength-mass relationships for aquatic insects of Navarino Island, extreme southern Chile
No full textRESUMEN: La biomasa es un parámetro clave en ecología, ya que proporciona información sobre el funcionamiento de los ecosistemas. Las estimaciones de longitud-peso se han utilizado ampliamente debido a sus procedimientos relativamente simples y directos. En este estudio, realizamos la primera evaluación de las relaciones longitud-peso para 25 especies de insectos acuáticos presentes en la ecoregión sub-Antártica chilena. Nuestros resultados indican que existe una fuerte correlación lineal entre el peso y el tamaño de los organismos, tal como indican los altos coeficientes de determinación. Encontramos valores bajos de b para la mayoría de los organismos estudiados, lo que podría indicar mudas recientes y/o grado de quitinización incompleta, o predominancia de estados de desarrollo iniciales. Si bien los parámetros estimados de las regresiones lineales y no lineales fueron similares a los reportados en otros estudios, es importante señalar que se debe evitar la extrapolación de datos desde otras áreas dada las particularidades inherentes de cada sistema. Esperamos que nuestros resultados fomenten la generación y recopilación de datos longitud-peso, ya que representan información importante sobre la biomasa y la producción secundaria, parámetros clave de la diversidad funcional
Phenolic composition and bioactivity of Ribes magellanicum fruits from southern Patagonia
No full textEight Ribes magellanicum collections from three different places in southern Patagonia were compared for content of different groups of phenolics, antioxidant capacity and inhibition of enzymes related to metabolic syndrome (alpha-amylase, alpha-glucosidase and pancreatic lipase). The sample with the highest antioxidant capacity was assessed for glutathione (GSH) synthesis stimulation in human gastric adenocarcinoma (AGS) cells. The chemical profile was determined by high performance liquid chromatography with tandem mass spectrometry detection (HPLCMS/MS) and the main phenolics were quantified. The samples from Navarino Island and Reserva Nacional Magallanes showed higher content of anthocyanins and caffeoylquinic acid, with better activity towards alpha-glucosidase and antioxidant capacity. A sample from Omora (Navarino Island), significantly increased intracellular GSH content in AGS cells. Some 70 compounds were identified in the fruit extracts by HPLC-MS/MS. The glucoside and rutinoside from delphinidin and cyanidin and 3-caffeoylquinic acid were the main compounds. Different chemical profiles were found according to the collection places