54 research outputs found

    Foraging ecology of masked boobies (Sula dactylatra) in the world’s largest “oceanic desert”

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    The South Pacific Gyre has the most hyper-oligotrophic waters in the world and is considered the largest “oceanic desert.” Rapa Nui (Easter Island), located within the South Pacific Gyre, is a breeding ground for masked boobies (Sula dactylatra), which are seabirds with a foraging range that effectively confines them within the gyre. The foraging ecology of this species in the gyre was examined by attaching GPS and time-depth devices to chick-rearing adult birds (9 and 14 birds in 2016 and 2017, respectively) and by collecting regurgitates (18 and 15 samples in 2016 and 2017, respectively). In addition, the birds’ foraging ecology between years was compared. Masked boobies traveled in various directions, dived at unspecific locations, and explored areas < 110 km from the colony. Local environmental conditions were not significantly different between years, and differences in foraging parameters (maximum foraging range, trip duration, and dive depth) were greater among individuals than between years. The foraging characteristics of masked boobies suggest that resources were ephemerally distributed around the colony, with similar abundances across years. Under these conditions, traveling to unspecific locations may increase the area covered and the probability of prey encounter. The spatial and temporal consistencies in environmental conditions explain the uniformity of foraging parameters between years. The ability of masked boobies to exploit ephemerally distributed resources in seascapes like Rapa Nui may help explain its pantropical distribution

    Enhance wine production potential by using fresh and dried red grape and blueberry mixtures with different yeast strains for fermentation

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    Red grapes and blueberries are known for their high content of bioactive compounds and antioxidant properties. In Mediterranean winemaking, traditional sun-drying can be replaced by controlled-airflow-chamber-drying, which provides better quality, higher phenolic content, and increased antioxidants. This study aimed to increase the sugar content and phenolic compounds of the must by drying the fruits to fifty per cent of their original moisture content. Two musts were prepared: the first one was prepared by combining fresh red grapes and dried blueberries (M1), while the other was created using dried red grapes and fresh blueberries (M2), followed by fermentation at 25 °C with M05 Mead and X5 yeast strains. The M2 must showed the highest levels of phenolic compounds, red color (A520), total anthocyanins, and antioxidant activity. During fermentation, the anthocyanin content increased mainly in the dried blueberry macerates, where it increased between 4- to 5.5-fold. More bioactive compounds were extracted from the wines produced using yeast inoculation despite the shorter maceration times. A sensory analysis demonstrated consumers’ acceptance of the wines in terms of color, flavor, and aroma. In conclusion, the use of red grapes in the production of blueberry red wine proved to be effective, providing higher sugar and must yields, while the dried fruits improved the fermentable sugar content obtaining wines with an alcoholic content between 10 and 11% (v/v). The higher levels of bioactive compounds increased the antioxidant capacity of the resulting red fruit wines

    BREEDING OF THE SOUTH AMERICAN TERN (STERNA HIRUNDINACEA) ON ANCHORED BOATS IN COQUIMBO, NORTHERN CHILE

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    Abstract · We report the breeding attempt of South American Terns (Sterna hirundinacea) on three boats in Coquimbo, northern Chile. The first breeding attempt was reported in winter 2011 where at least one chick fledged. From April to June 2015, all nests on the boats were monitored. We recorded eggs and chicks during May and early June. However, towards the end of June, no eggs or chicks were recorded in the nests, and a Chimango Caracara (Phalcoboenus chimango) was observed preying on chicks in one nest. In April and May 2017, breeding attempts on boats were also monitored and nests with eggs and one chick were recorded. However, at the end of May all nests were empty. This unusual nesting site for South American Terns is apparently regularly used in the area despite its virtually null breeding success. Resumen · Reproducción del Gaviotín Sudamericano (Sterna hirundinacea) en botes anclados en Coquimbo, norte de Chile Reportamos el intento de reproducción del Gaviotín Sudamericano (Sterna hirundinacea) sobre tres botes en Coquimbo, norte de Chile. Un primer intento de reproducción para esta zona se registró en invierno de 2011, donde al menos un pollo dejó un nido como volantón. Entre Abril y Junio de 2015 monitoreamos los nidos en los botes de manera más intensiva. Registramos huevos y pollos durante Mayo y principios de Junio. Sin embargo, a finales de Junio, no registramos huevos en los nidos y observamos un Tiuque (Phalcoboenus chimango) depredar sobre los pollos. En Abril y Mayo de 2017, monitoreamos otros intentos de reproducción y registramos un pollo y nidos con huevos. Sin embargo, a finales de Mayo, esos nidos estaban vacíos. Este inusual sitio de nidificación parece ser utilizado de forma recurrente por el Gaviotín Sudamericano, a pesar del aparente casi nulo éxito reproductivo

    Targeted Metabolomics Shows That the Level of Glutamine, Kynurenine, Acyl-Carnitines and Lysophosphatidylcholines Is Significantly Increased in the Aqueous Humor of Glaucoma Patients.

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    The composition of the aqueous humor of patients with glaucoma is relevant to understand the underlying causes of the pathology. Information on the concentration of metabolites and small molecules in the aqueous humor of healthy subjects is limited. Among the causes of the limitations is the lack of healthy controls since, until recently, they were not surgically intervened; therefore, the aqueous humor of patients operated for cataract was used as a reference. Sixteen aqueous humor samples from healthy subjects undergoing refractive surgery and eight samples from glaucoma patients were used to assess the concentration of 188 compounds using chromatography and mass spectrometry. The concentration of 80 of the 188 was found to be reliable, allowing comparison of data from the two groups (glaucoma and control). The pattern found in the controls is similar to, but not the same as, that reported using samples from 'controls' undergoing cataract surgery. Comparing data from glaucoma patients and healthy subjects, 57 of the 80 compounds were significantly (p < 0.05) altered in the aqueous humor. Kynurenine and glutamine, but not glutamate, were significantly increased in the glaucoma samples. Furthermore, 10 compounds were selected considering a statistical score of p < 0.0001 and the degree of change of more than double or less than half. The level of C10 (decanoyl)-carnitine decreased, while the concentration of spermidine and various acyl-carnitines and lysophosphatidylcholines increased in glaucoma. Principal component analysis showed complete segregation of controls and cases using the data for the 10 selected compounds. The receiver operating characteristic curve these 10 compounds and for glutamine allowed finding cut-off values and significant sensitivity and specificity scores. The concentration of small metabolites in the aqueous humor of glaucoma patients is altered even when they take medication and are well controlled. The imbalance affects membrane components, especially those of the mitochondria, suggesting that mitochondrial abnormalities are a cause or consequence of glaucoma. The increase in glutamine in glaucoma is also relevant because it could be a means of keeping the concentration of glutamate under control, thus avoiding its potential to induce the death of neurons and retinal cells. Equally notable was the increase in kynurenine, which is essential in the metabolism of nicotine adenine dinucleotides

    Development of a database for the study of food additives in food chemistry subjects

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    Las TIC o tecnologías de la información y comunicación son una herramienta que permite un mayor desarrollo personal para el alumno, siendo él el protagonista en lugar del profesor. Con estas herramientas se adquieren diferentes competencias básicas necesarias para los alumnos universitarios, como son la capacidad de trabajo en equipo, la creatividad, el aprendizaje autónomo, entre otras. Además, los alumnos fueron partícipes en la evaluación de las actividades fomentando así también las competencias básicas relacionadas con la evaluación, como la reflexión. El objetivo de este trabajo era desarrollar una base de datos sobre aditivos, incluyendo información sobre clasificación, fórmula química, grupo al que pertenece, masa molecular, toxicidad, ingesta diaria admitida. La base de datos se crea mediante la participación de alumnos en diferentes actividades de búsqueda de información. Esta base de datos estaría disponible para los alumnos y serviría a su vez al profesor para la realización de nuevas actividades a través de la plataforma Moodle de la Universidad de Córdoba.ICT or information and communication technologies are a tool that allows a greater personal development for the student, being the protagonist instead of the teacher. With these tools, different basic competencies necessary for university students are acquired, such as teamwork, creativity, autonomous learning, among others. In addition, students were involved in the evaluation of activities, thus also promoting the basic competencies related to evaluation, such as reflection. The objective of this job was to develop a database on additives, including information on classification, chemical formula, group to which it belongs, molecular mass, toxicity, acceptable daily intake. The database is created through the participation of students in different information search activities. This database would be available to students and would in turn serve the professor for the realization of new activities through the Moodle platform of the University of Córdoba

    Unveiling the Metabolic changes on muscle cell metabolism underlying p-phenylenediamine toxicity

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    Rhabdomyolysis is a disorder characterized by acute damage of the sarcolemma of the skeletal muscle leading to release of potentially toxic muscle cell components into the circulation, most notably creatine phosphokinase (CK) and myoglobulin, and is frequently accompanied by myoglobinuria. In the present work, we evaluated the toxicity of p-phenylenediamine (PPD), a main component of hair dyes which is reported to induce rhabdomyolysis. We studied the metabolic effect of this compound in vivo with Wistar rats and in vitro with C2C12 muscle cells. To this aim we have combined multi-omic experimental measurements with computational approaches using model-driven methods. The integrative study presented here has unveiled the metabolic disorders associated to PPD exposure that may underlay the aberrant metabolism observed in rhabdomyolys disease. Animals treated with lower doses of PPD (10 and 20 mg/kg) showed depressed activity and myoglobinuria after 10 h of treatment. We measured the serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatine kinase (CK) in rats after 24, 48, and 72 h of PPD exposure. At all times, treatment with PPD at higher doses (40 and 60 mg/kg) showed an increase of AST and ALT, and also an increase of lactate dehydrogenase (LDH) and CK after 24 h. Blood packed cell volume and hemoglobin levels, as well as organs weight at 48 and 72 h, were also measured. No significant differences were observed in these parameters under any condition. PPD induce cell cycle arrest in S phase and apoptosis (40% or early apoptotic cells) on mus musculus mouse C2C12 cells after 24 h of treatment. Incubation of mus musculus mouse C2C12 cells with [1,2-13C2]-glucose during 24 h, subsequent quantification of 13C isotopologues distribution in key metabolites of glucose metabolic network and a computational fluxomic analysis using in-house developed software (Isodyn) showed that PPD is inhibiting glycolysis, non-oxidative pentose phosphate pathway, glycogen turnover, and ATPAse reaction leading to a reduction in ATP synthesis. These findings unveil the glucose metabolism collapse, which is consistent with a decrease in cell viability observed in PPD-treated C2C12 cells and with the myoglubinuria and other effects observed in Wistar Rats treated with PPD. These findings shed new light on muscle dysfunction associated to PPD exposure, opening new avenues for cost-effective therapies in Rhabdomyolysis disease

    Induction of oxidative metabolism by the p38α/MK2 pathway

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    Adequate responses to environmental stresses are essential for cell survival. The regulation of cellular energetics that involves mitochondrial energy production and oxidative stress is central in the process of stress adaptation and response. The p38α signalling pathway plays a key role in the response to stress stimuli by orchestrating multiple cellular processes. However, prolonged activation of the p38α pathway results in impaired cell proliferation and can lead to cell death. Here we use a system to specifically activate p38α signalling and show that sustained activation of this pathway suffices to induce important metabolic changes, including high dependence on glucose for cell survival, increased consumption of glutamine, enhanced respiration rate and elevated production of mitochondrial reactive oxygen species (ROS). Moreover, we provide evidence that increased production of mitochondrial superoxide as a consequence of elevated mitochondria activity, contributes to the p38α reduced cell survival triggered by sustained p38α activation. We also show that the p38α-activated kinase MAPKAPK2 (MK2) plays an important role orchestrating the observed metabolic changes. Our results illustrate a new function of p38α signalling in the regulation of cellular metabolism, which may lead to cell death upon persistent activation of the pathway

    FaMYB123 interacts with FabHLH3 to regulate the late steps of anthocyanin and flavonol biosynthesis during ripening.

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    In this work, we identified and functionally characterized the strawberry (Fragaria × ananassa) R2R3 MYB transcription factor FaMYB123. As in most genes associated with organoleptic properties of ripe fruit, FaMYB123 expression is ripening-related, receptacle-specific, and antagonistically regulated by ABA and auxin. Knockdown of FaMYB123 expression by RNAi in ripe strawberry fruit receptacles downregulated the expression of enzymes involved in the late steps of anthocyanin/flavonoid biosynthesis. Transgenic fruits showed a parallel decrease in the contents of total anthocyanin and flavonoid, especially malonyl derivatives of pelargonidin and cyanidins. The decrease was concomitant with accumulation of proanthocyanin, propelargonidins, and other condensed tannins associated mainly with green receptacles. Potential coregulation between FaMYB123 and FaMYB10, which may act on different sets of genes for the enzymes involved in anthocyanin production, was explored. FaMYB123 and FabHLH3 were found to interact and to be involved in the transcriptional activation of FaMT1, a gene responsible for the malonylation of anthocyanin components during ripening. Taken together, these results demonstrate that FaMYB123 regulates the late steps of the flavonoid pathway in a specific manner. In this study, a new function for an R2R3 MYB transcription factor, regulating the expression of a gene that encodes a malonyltransferase, has been elucidated.This work was funded by the Spanish Ministerio de Ciencia e Innovacion (AGL2014-55784-C2-2-R and AGL2017-86531-C2-2-R). FJMR is supported by a ‘Margarita Salas’ post-doctoral fellowship (UCOR02MS) from the University of Cordoba (Requalification of the Spanish university system) from the Ministry of Universities financed by the European Union (NexGenerationEU). FJMH is supported by a ‘Juan de la Cierva-Incorporacion’ fellowship (IJC2020- 045526-I), funded by MCIN/AEI/10.13039/501100011033 and the European Union ‘NextGenerationEU’/PRTR. AR-F and SA are on the European Union’s Horizon 2020 Research and Innovation Program, Project PlantaSYST (SGA-CSA No. 739582 under FPA No. 664620). The authors thank Dr. Gema Garc ıa from the Microscopy Unit of UCAIB-IMIBIC for technical help with the microscope. Funding for open access charge: University of Cordoba/CBUA.S

    MSClique: Multiple structure discovery through the maximum weighted clique problem

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    We present a novel approach for feature correspondence and multiple structure discovery in computer vision. In contrast to existing methods, we exploit the fact that point-sets on the same structure usually lie close to each other, thus forming clusters in the image. Given a pair of input images, we initially extract points of interest and extract hierarchical representations by agglomerative clustering. We use the maximum weighted clique problem to find the set of corresponding clusters with maximum number of inliers representing the multiple structures at the correct scales. Our method is parameter-free and only needs two sets of points along with their tentative correspondences, thus being extremely easy to use. We demonstrate the effectiveness of our method in multiple-structure fitting experiments in both publicly available and in-house datasets. As shown in the experiments, our approach finds a higher number of structures containing fewer outliers compared to state-of-the-art methods.Peer ReviewedPostprint (published version
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