Breeding Phenology and New Host List of the Black-Headed Duck (<i>Heteronetta atricapilla</i>) In Argentina

The Black-headed Duck (Heteronetta atricapilla) is a unique interspecific brood parasite among birds where the host species provides parental care for incubation only. Despite this unique system, there are few studies on this species biology and the list of hosts remains incomplete. We present information about breeding phenology of the Blackheaded Duck and an updated list of hosts obtained from a comprehensive review of egg collections deposited in the most important natural science museums of Argentina. We include five new hosts to the list: Great Grebe (Podiceps major), Maguari Stork (Ciconia maguari), White-cheeked Pintail (Anas bahamensis), South American Stilt (Himantopus mexicanus), and Long-winged Harrier (Circus buffoni). We found that solitary nesting host species were more likely to be parasitized earlier during the breeding season than colonial nesting species. The Black-headed Duck has an extended breeding season in central Argentina (Aug–Feb) as it is able to use a variety of hosts that breed in different times during the breeding season. With this contribution, the new list rises to 23 documented hosts of the Black-headed Duck belonging to eight different waterfowl orders.Facultad de Ciencias Naturales y Muse

Contribution of migrant coffee labourers infected with Onchocerca volvulus to the maintenance of the microfilarial reservoir in an ivermectin-treated area of Mexico

BACKGROUND: Since 1991, in Mexico, ivermectin has been administered twice a year to all residents in the onchocerciasis endemic foci which are mainly located in the coffee growing areas. However, the presence of a potentially infected itinerant seasonal labour force which is not treated regularly could jeopardise the attainment of the 85% coverage which is the present target for elimination of the disease. METHODS: The prevalence and intensity of Onchocerca volvulus microfilariae (mf), as well as their transmission from humans to vectors, were assessed during the coffee planting-clearing and harvesting seasons of 1997-1998, and 1998-1999 in two localities (I and II) of Southern Chiapas, Mexico, which regularly receive an influx of untreated migrant coffee labourers. RESULTS: Localities I and II had, respectively, an average of 391 (+/- 32) and 358 (+/- 14) resident inhabitants, and 70 (+/- 52) and 498 (+/- 289) temporary labourers. The ratio of migrants to residents ranged from 0.1:1 in locality I to 2.4:1 in locality II. The proportion of infected Simulium ochraceum s.l. parous flies was significantly lower in locality I than in locality II, and significantly higher during the stay of the migrants than before their arrival or after their departure. Parity and infection were higher in May-July than in November-February (in contrast with the latter being typically considered as the peak onchocerciasis transmission season by S. ochraceum s.l.). CONCLUSION: The presence of significant numbers of untreated and potentially infected migrants may contribute to ongoing transmission, and their incorporation into ivermectin programmes should be beneficial for the attainment of the elimination goals of the regional initiative. However, the possibility that the results also reflect transmission patterns for the area cannot be excluded and these should be analyzed further

PHF2 regulates homology-directed DNA repair by controlling the resection of DNA double strand breaks

Post-translational histone modifications and chromatin remodelling play a critical role controlling the integrity of the genome. Here, we identify histone lysine demethylase PHF2 as a novel regulator of the DNA damage response by regulating DNA damage-induced focus formation of 53BP1 and BRCA1, critical factors in the pathway choice for DNA double strand break repair. PHF2 knockdown leads to impaired BRCA1 focus formation and delays the resolution of 53BP1 foci. Moreover, irradiation-induced RPA phosphorylation and focus formation, as well as localization of CtIP, required for DNA end resection, to sites of DNA lesions are affected by depletion of PHF2. These results are indicative of a defective resection of double strand breaks and thereby an impaired homologous recombination upon PHF2 depletion. In accordance with these data, Rad51 focus formation and homology-directed double strand break repair is inhibited in cells depleted for PHF2. Importantly, we demonstrate that PHF2 knockdown decreases CtIP and BRCA1 protein and mRNA levels, an effect that is dependent on the demethylase activity of PHF2. Furthermore, PHF2-depleted cells display genome instability and are mildly sensitive to the inhibition of PARP. Together these results demonstrate that PHF2 promotes DNA repair by homologous recombination by controlling CtIP-dependent resection of double strand breaks.España Ministerio de Ciencia e Innovacion SAF2016-80626-REspaña, Fundación Canaria Instituto de Investigación Sanitaria de Canarias (FIISC) [PIFUN16/18

Investigación-acción participativa y mecanismos de gobernanza territorial en áreas naturales protegidas costeras de Chubut (Patagonia, Argentina)

Todo sector costero constituye un espacio complejo, definido por una gran variedad de recursos naturales bióticos, geomorfológicos y energéticos. Es un ecosistema de transición que, caracterizado por su abundancia y diversidad, atrae una importante concentración de población humana que demanda cada vez más por espacios libres para el desarrollo de actividades y usos diversificados. Son múltiples los beneficios directos e indirectos que proveen los sistemas ecológicos costeros a las comunidades. Asimismo, las interrelaciones, convergencia y funcionalidad integrada a los recursos naturales marinos, potencian el desarrollo de los asentamientos humanos en las costas. En Patagonia, Argentina, ésta situación representa un problema para la conservación de las especies y de sus ambientes costeros, dada la superposición en la utilización de los mismos por parte de las comunidades locales y el turismo de ?observación de fauna silvestre?, un disturbio directo que se encuentra en clara expansión. Es por ello que, a través de un estudio de caso local, queremos promover estrategias e implementar acciones de desarrollo territorial sostenible para lograr una disminución de los impactos de las actividades humanas recreacionales y del turismo sobre la reproducción y nidificación de aves playeras en áreas costeras próximas a Puerto Madryn, Chubut. En este sentido, como primer paso, hemos logrado la identificación de los espacios costeros en conflicto con las áreas reproductivas de las aves, a través de un enfoque de investigación-acción participativa y del establecimiento de vínculos colaborativos con agentes de conservación (guardaparques). Sin embargo, a mediano plazo (2 años), nuestro objetivo radica en desarrollar mecanismos de gobernanza territorial a nivel local, articulando alianzas con las autoridades de aplicación de áreas naturales protegidas de jurisdicción municipal y provincial; dado que, como proceso social, la gobernanza representa un eje conductor clave en los procesos de toma de decisiones respecto al manejo de la vida silvestre.Fil: Hevia, Glenda Denise. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: D'amico, Veronica Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Bertellotti, Néstor Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; ArgentinaFil: Cabrera, María B.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina2016 Latin American & Caribbean ESP Conference: Healthy ecosystems for resilient societiesCaliColombiaInternational Center for Tropical AgricultureInstituto HumboldtEmpresa Brasileña de Investigación AgropecuariaEcosystem Services Parnershi

Propagación de tomate de árbol (Solanum betaceum) vía embriogénesis somática

A reproducible micropropagation protocol for tamarillo (Solanum betaceum) via somatic embryogenesis was established in this study. Three types of explants were assayed: leaves, hypocotyls and zygotic embryos; all of them obtained from in vitro cultured seeds. Different concentrations of auxins 2, 4-D (2,4-dichlorophenoxyacetic acid) and NAA (a- napthaleneacetic acid) and sucrose were tested to find out an appropriate medium that sti­mulated the formation of embryogenic calli. MS medium supplemented with 5 mg/L of NAA and 90 g/L of sucrose (pH 5.8) induced somatic embryos formation from the upper thirds of hypocotyls and from zygotic embryos. One-hundred percent of the explants deri­ved from zygotic embryos and hypocotyls developed big whitish calli. However, only 40 % of the hypocotyl-derived calli and 70 % of the zygotic embryo-derived calli produced so­matic embryos. The results showed that somatic embryos were obtained after a four-week incubation period in MS medium supplemented with 5 mg/L of NAA and 90 g/L of sucrose. The somatic embryos grew rapidly and produced plantlets with normal phenotypes. These results suggest that this technique could be applied for large scale production of Tamarillo and other agronomically important Andean fruit crops.En esta investigación se estableció un método reproducible de micropropagación de tomate de árbol (Solanum betaceum), a partir de embriones somáticos. Se usaron tres tipos de explantes, hojas, hipocótilos y embriones cigóticos, los cuales fueron obtenidos a partir de semillas de tomate de árbol de la variedad anaranjada común cultivadas in vitro. Se probaron dos tipos de auxinas 2,4-D (ácido 2,4-dicloro fenoxiacético) y ANA (ácido a-naftalenacético), y sacarosa en distintas concentraciones a fin de encontrar un medio de cultivo que estimule la formación de callo embriogénico. Se encontró que el medio MS suplementado con 5 mg/L de ANA y 90 gr/L de sacarosa a pH 5,8 promovió la formación de embriones somáticos a partir del tercio superior de los hipocótilos y de embriones ci- góticos. El 100% de los explantes provenientes de embriones cigóticos y de hipocótilos formaron callos de buen tamaño y de una coloración blanco cremosa. Sin embargo, la for­mación de embriones somáticos en los callos obtenidos a partir de hipocótilos fue tan solo del 40 %, mientras que con los embriones cigóticos fue del 70 %. Los resultados mostraron que en medio MS suplementado con 5 mg/L de ANA y 90 gr/L de sacarosa se obtuvieron embriones somáticos a partir de la cuarta semana de cultivo, los cuales se desarrollaron rápidamente y produjeron plántulas sin anormalidades. Estos resultados evidencian la apli- cabilidad de esta técnica para la producción a gran escala de plantas de interés agrícola para el país

Chitosan Induces Plant Hormones and Defenses in Tomato Root Exudates

In this work, we use electrophysiological and metabolomic tools to determine the role of chitosan as plant defense elicitor in soil for preventing or manage root pests and diseases sustainably. Root exudates include a wide variety of molecules that plants and root microbiota use to communicate in the rhizosphere. Tomato plants were treated with chitosan. Root exudates from tomato plants were analyzed at 3, 10, 20, and 30 days after planting (dap). We found, using high performance liquid chromatography (HPLC) and excitation emission matrix (EEM) fluorescence, that chitosan induces plant hormones, lipid signaling and defense compounds in tomato root exudates, including phenolics. High doses of chitosan induce membrane depolarization and affect membrane integrity. 1H-NMR showed the dynamic of exudation, detecting the largest number of signals in 20 dap root exudates. Root exudates from plants irrigated with chitosan inhibit ca. twofold growth kinetics of the tomato root parasitic fungus Fusarium oxysporum f. sp. radicis-lycopersici. and reduced ca. 1.5-fold egg hatching of the root-knot nematode Meloidogyne javanica.This work was supported by AGL 2015 66833-R Grant from the Spanish Ministry of Economy and Competitiveness and H2020 MUSA 727624 European Project

Comorbidity and osteoporotic fracture: approach through predictive modeling techniques using the OSTEOMED registry

Purpose To examine the response to anti-osteoporotic treatment, considered as incident fragility fractures after a minimum follow-up of 1 year, according to sex, age, and number of comorbidities of the patients. Methods For this retrospective observational study, data from baseline and follow-up visits on the number of comorbidities, prescribed anti-osteoporotic treatment and vertebral, humerus or hip fractures in 993 patients from the OSTEOMED registry were analyzed using logistic regression and an artificial network model. Results Logistic regression showed that the probability of reducing fractures for each anti-osteoporotic treatment consid- ered was independent of sex, age, and the number of comorbidities, increasing significantly only in males taking vitamin D (OR = 7.918), patients without comorbidities taking vitamin D (OR = 4.197) and patients with ≥ 3 comorbidities taking calcium (OR = 9.412). Logistic regression correctly classified 96% of patients (Hosmer–Lemeshow = 0.492) compared with the artificial neural network model, which correctly classified 95% of patients (AUC = 0.6). Conclusion In general, sex, age and the number of comorbidities did not influence the likelihood that a given anti-osteoporotic treatment improved the risk of incident fragility fractures after 1 year, but this appeared to increase when patients had been treated with risedronate, strontium or teriparatide. The two models used classified patients similarly, but predicted differently in terms of the probability of improvement, with logistic regression being the better fit

A contribution to the checklist of fishes of San Luis Province, Argentina

San Luis province presents arheic and endorheic basins that are poorly understood in terms of their ichthyological composition. The samples taken recently from the main basins of this province have yielded data of undisputed biogeographic value for the knowledge of the ichthyofauna of San Luis, as well as for drawing up lists of species for watersheds with poor or absent previous records. Here, we cite Jenynsia multidentata from the Desaguadero and Bebedero rivers, Cnesterodon decemmaculatus for Chorrillos River, and Oligosarcus jenynsii for Luján, Quines and Quinto rivers. We add five taxa to the Nogolí River that have not been previously reported. We also present for the first time a list of the fish fauna from the Conlara, Luján and Quines basins. Our results provide 34 new records of freshwater fish distribution.Facultad de Ciencias Naturales y Muse

Physiological and genetic control of transpiration efficiency in African rice, Oryza glaberrima Steud

Improving crop water use efficiency, the amount of carbon assimilated as biomass per unit of water used by a plant, is of major importance as water for agriculture becomes scarcer. In rice, the genetic bases of transpiration efficiency, the derivation of water use efficiency at the whole-plant scale, and its putative component trait transpiration restriction under high evaporative demand remain unknown. These traits were measured in 2019 in a panel of 147 African rice (Oryza glaberrima) genotypes known to be potential sources of tolerance genes to biotic and abiotic stresses. Our results reveal that higher transpiration efficiency is associated with transpiration restriction in African rice. Detailed measurements in a subset of highly contrasted genotypes in terms of biomass accumulation and transpiration confirmed these associations and suggested that root to shoot ratio played an important role in transpiration restriction. Genome wide association studies identified marker-trait associations for transpiration response to evaporative demand, transpiration efficiency, and its residuals, with links to genes involved in water transport and cell wall patterning. Our data suggest that root-shoot partitioning is an important component of transpiration restriction that has a positive effect on transpiration efficiency in African rice. Both traits are heritable and define targets for breeding rice with improved water use strategies.This work was supported by the Institut de Recherche pour le Développement, the CGIAR Research Program (CRP) on rice-agrifood systems (RICE, 2017-2022) and the Agence Nationale de la Recherche (grant ANR-17-MPGA-0011 to VV). Financial support by the Access to Research Infrastructures activity in the Horizon 2020 Programme of the EU (EPPN2020 Grant Agreement 731013) is gratefully acknowledged. PA was supported by a doctoral fellowship from the French Ministry of Higher Education. BEE was supported by the Centre National de la Recherche Scientifique et Technologique of Gabon. The authors acknowledge the IRD iTrop HPC (South Green Platform) at IRD Montpellier for providing HPC resources (https://bioinfo.ird.fr, http://www.southgreen.fr)

A plasma fatty acid profile associated to type 2 diabetes development: from the CORDIOPREV study

Purpose: The prevalence of type 2 diabetes mellitus (T2DM) is increasing worldwide. For this reason, it is essential to identify biomarkers for the early detection of T2DM risk and/or for a better prognosis of T2DM. We aimed to identify a plasma fatty acid (FA) profile associated with T2DM development. Methods: We included 462 coronary heart disease patients from the CORDIOPREV study without T2DM at baseline. Of these, 107 patients developed T2DM according to the American Diabetes Association (ADA) diagnosis criteria after a median follow-up of 60 months. We performed a random classification of patients in a training set, used to build a FA Score, and a Validation set, in which we tested the FA Score. Results: FA selection with the highest prediction power was performed by random survival forest in the Training set, which yielded 4 out of the 24 FA: myristic, petroselinic, α-linolenic and arachidonic acids. We built a FA Score with the selected FA and observed that patients with a higher score presented a greater risk of T2DM development, with an HR of 3.15 (95% CI 2.04–3.37) in the Training set, and an HR of 2.14 (95% CI 1.50–2.84) in the Validation set, per standard deviation (SD) increase. Moreover, patients with a higher FA Score presented lower insulin sensitivity and higher hepatic insulin resistance (p < 0.05). Conclusión: Our results suggest that a detrimental FA plasma profile precedes the development of T2DM in patients with coronary heart disease, and that this FA profile can, therefore, be used as a predictive biomarker