83 research outputs found
Bacteria and the evolution of honest signals. The case of ornamental throat feathers in spotless starlings
1. Mechanisms guaranteeing reliability of messages are essential in understanding the underlying
information and evolution of signals. Micro-organisms may degrade signalling traits and
therefore influence the transmitted information and evolution of these characters. The role of
micro-organisms in animal signalling has, however, rarely been investigated.
2. Here, we explore a possible role for feather-degrading bacteria driving the design of ornamental
throat feathers in male spotless starlings (Sturnus unicolor). We estimated length, bacterial
load, degradation status and susceptibility to degradation by keratinolytic bacteria in
those feathers, compared with non-ornamental adjacent feathers in males, as well as to throat
feathers in females. In addition, the volume of the uropygial gland and its secretion was measured
and the secretion extracted. We also experimentally evaluated the capacity of each secretion
to inhibit growth of a keratinolytic bacterium.
3. The apical part of male ornamental throat feathers harboured more bacteria and degraded
more quickly than the basal part; these patterns were not detected in female throat feathers or
in non-ornamental male feathers. Moreover, degradation status of male and female throat
feathers did not differ, but was positively associated with feather bacterial density. Finally, the
size of the uropygial gland in both males and females predicted volume and the inhibitory
capacity of secretion against feather-degrading bacteria. Only in males was uropygial gland
size negatively associated with the level of feather degradation.
4. All results indicate differential susceptibility of different parts of throat feathers to keratinolytic
bacterial attack, which supports the possibility that throat feathers in starlings reflect individual
ability to combat feather-degrading bacteria honestly. This is further supported by the
relationship detected between antimicrobial properties of uropygial secretion and the level of
feather degradation.
5. Our results suggest that selection pressures exerted by feather-degrading bacteria on hosts
may promote evolution of particular morphologies of secondary sexual traits with different
susceptibility to bacterial degradation that reliably inform of their bacterial load. Those results
will help to understand the evolution of ornamental signals.This work was financed by Spanish Ministerio de Ciencia e Innovaci on, European
funds (FEDER) (CGL2010-19233-C03-01, CGL2013-48193-C3-1-P). MRR and DMG received a postdoc from the program “JAE-Doc”, GT from the “Juan de la Cierva”, and CRC had a predoctoral fellowship, all from the Spanish Government.Peer reviewe
Nest Material Shapes Eggs Bacterial Environment
Selective pressures imposed by pathogenic microorganisms to embryos have selected in hosts for a battery of antimicrobial lines of defenses that includes physical and chemical barriers. Due to the antimicrobial properties of volatile compounds of green plants and of chemicals of feather degrading bacteria, the use of aromatic plants and feathers for nest building has been suggested as one of these barriers. However, experimental evidence suggesting such effects is scarce in the literature. During two consecutive years, we explored experimentally the effects of these nest materials on loads of different groups of bacteria (mesophilic bacteria, Enterobacteriaceae, Staphylococcus and Enterococcus) of eggshells in nests of spotless starlings (Sturnus unicolor) at the beginning and at the end of the incubation period. This was also explored in artificial nests without incubation activity. We also experimentally increased bacterial density of eggs in natural and artificial nests and explored the effects of nest lining treatments on eggshell bacterial load. Support for the hypothetical antimicrobial function of nest materials was mainly detected for the year and location with larger average values of eggshell bacterial density. The beneficial effects of feathers and plants were more easily detected in artificial nests with no incubation activity, suggesting an active role of incubation against bacterial colonization of eggshells. Pigmented and unpigmented feathers reduced eggshell bacterial load in starling nests and artificial nest boxes. Results from artificial nests allowed us to discuss and discard alternative scenarios explaining the detected association, particularly those related to the possible sexual role of feathers and aromatic plants in starling nests. All these results considered together confirm the antimicrobial functionality mainly of feathers but also of plants used as nest materials, and highlight the importance of temporally and geographically environmental variation associated with risk of bacterial proliferation determining the strength of such effects. Because of costs associated to nest building, birds should adjust nest building effort to expected bacterial environments during incubation, a prediction that should be further explored.This work was financed by Spanish Ministerio de Ciencia e Innovación, European funds (FEDER) (CGL2010-19233-C03-01, CGL2010-19233-C03-03, CGL2013-48193-C3-1-P, CGL2013-48193-C3-3-P). MRR and DMG received a postdoc from the programmes “JAE-Doc” and CRC had a predoctoral grant from the Spanish Government. GT was supported by Juan de la Cierva programme (Spain)
and by Secretaría de Educación Superior, Ciencia, Tecnología e Innovación del Ecuador (SENESCYT)
through a Prometeo research grant.Peer reviewe
Context dependent effects of an experimental increase of hunger level in house sparrow nestlings
Exploring the links between parental supply and nestling demands and between nestling demand and food supply is of central importance for understanding the evolution of parent-offspring communication. It has been suggested that optimal food supply by parents and begging effort of nestlings are context dependent, and we here test some predictions of this hypothesis. House sparrow (Passer domesticus) nestlings were experimentally fed with a pharmacological appetitive stimulant (cyproheptadine) that increases nestling demands, and explore its effect on nestling growth (i.e. body mass and tarsus length), which can be considered as the net payoff of inflated and costly offspring demand. As assumed by the experimental protocol, nestlings with an exaggerated demand were preferentially fed by parents. In accordance with the hypothesis, net benefits in terms of growth were mainly detected in first breeding attempt of parents that successfully reared three broods. Because costs associated with parental feeding should be lower for first breeding attempts and for parents of higher phenotypic quality (those able to successfully rear three clutches), our results provide to our knowledge, the first experimental evidence supporting a dynamic role of costs of food supply affecting net payoff of offspring demands, which may help to understand the mechanisms allowing the evolutionary equilibrium between intensities of offspring begging and parental provisioning.This work was financed by Spanish Ministerio de Ciencia e Innovación, Ministerio de Economía y Competitividad, European funds (FEDER) (CGL2013-48193-C3-1-P to JJS and CGL2007-61940/BOS To MS). DM-G received a postdoc from the programme “JAE-Doc” of the CSIC, and CR-C had a pre-doctoral grant from the Spanish Government.Peer reviewe
Ornamental Throat Feathers Predict Telomere Dynamic and Hatching Success in Spotless Starling (Sturnus unicolor) Males
Pobreza en la ocupación e instrumentos de reacción
Unión Europea,Ministerio de Economía y Competitividad y el Fondo Europeo de Desarrollo Regional DER2015-63701-C3-1-
Predictive signature of response to neoadjuvant chemotherapy in muscle-invasive bladder cancer integrating mRNA expression, taxonomic subtypes, and clinicopathological features
Background and objectiveNeoadjuvant chemotherapy (NAC) followed by cystectomy is the standard of care in muscle-invasive bladder cancer (MIBC). Pathological response has been associated with longer survival, but no currently available clinicopathological variables can identify patients likely to respond, highlighting the need for predictive biomarkers. We sought to identify a predictive signature of response to NAC integrating clinical score, taxonomic subtype, and gene expression.Material and methodsFrom 1994 to 2014, pre-treatment tumor samples were collected from MIBC patients (stage T2-4N0/+M0) at two Spanish hospitals. A clinical score was determined based on stage, hydronephrosis and histology. Taxonomic subtypes (BASQ, luminal, and mixed) were identified by immunohistochemistry. A custom set of 41 genes involved in DNA damage repair and immune response was analyzed in 84 patients with the NanoString nCounter platform. Genes related to pathological response were identified by LASSO penalized logistic regression. NAC consisted of cisplatin/methotrexate/vinblastine until 2000, after which most patients received cisplatin/gemcitabine. The capacity of the integrated signature to predict pathological response was assessed with AUC. Overall survival (OS) and disease-specific survival (DSS) were analyzed with the Kaplan-Meier method.ResultsLASSO selected eight genes to be included in the signature (RAD51, IFNγ, CHEK1, CXCL9, c-MET, KRT14, HERC2, FOXA1). The highest predictive accuracy was observed with the inclusion in the model of only three genes (RAD51, IFNɣ, CHEK1). The integrated clinical-taxonomic-gene expression signature including these three genes had a higher predictive ability (AUC=0.71) than only clinical score plus taxonomic subtype (AUC=0.58) or clinical score alone (AUC=0.56). This integrated signature was also significantly associated with OS (p=0.02) and DSS (p=0.02).ConclusionsWe have identified a predictive signature for response to NAC in MIBC patients that integrates the expression of three genes with clinicopathological characteristics and taxonomic subtypes. Prospective studies to validate these results are ongoing
Impact of hospitalization on nutritional status in persons aged 65 years and over (NUTRIFRAG Study): Protocol for a prospective observational study
[ES] Background
Malnutrition is a recurring problem that has become more relevant in recent years. The aim
of this study is to assess the risk of malnutrition and nutritional status on admission and its
evolution until discharge in patients aged 65 and over admitted to medical and surgical hospitalization units in hospitals of the Spanish National Health System.
Methods
Prospective observational study to be carried out in the medical-surgical hospitalization
units of 9 public hospitals between 01/09/2022 and 31/12/2024. Using consecutive sampling, a total of 4077 patients will be included (453 in each hospital). Variables included are
related to the care process, functionality, cognition and comorbidity, risk profile, nutritional
status and dysphagia; as well as frailty, dietary quality and contextual variables. The incidence of risk of malnutrition, undernutrition and dysphagia during the care process and at
discharge will be calculated. The association with risk factors will be studied with logistic
regression models and multivariate Cox regression models. In addition, an analysis of participants’ satisfaction with food services will be carried out. The study was approved by the
Ethics and Research Committee on 30/09/2020, approved for funding on 02/12/2021 and
with registration number RBR-5jnbyhk in the Brazilian clinical trials database (ReBEC) for
observational studies.
Discussion
Some studies address nutritional status or dysphagia in older people in various care settings. However, there is a lack of large sample studies including both processes of the
impact of hospitalization. The results of the project will provide information on the incidence
and prevalence of both pathologies in the study subjects, their associated factors and their
relationship with the average length of stay, mortality and early readmission. In addition,
early detection of a problem such as malnutrition related to the disease and/or dysphagia
during a hospital stay will favor the action of professionals to resolve both pathologies and
improve the health status of patients.This study has been funded by Instituto de Salud Carlos III (ISCIII) through the Project "PI21/00738" and co-funded by the European Union. The funders did not and will not have a role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Impact of hospitalization on nutritional status in persons aged 65 years and over (NUTRIFRAG Study): Protocol for a prospective observational study
Background: Malnutrition is a recurring problem that has become more relevant in recent years. The aim of this study is to assess the risk of malnutrition and nutritional status on admission and its evolution until discharge in patients aged 65 and over admitted to medical and surgical hospitalization units in hospitals of the Spanish National Health System. Methods: Prospective observational study to be carried out in the medical-surgical hospitalization units of 9 public hospitals between 01/09/2022 and 31/12/2024. Using consecutive sampling, a total of 4077 patients will be included (453 in each hospital). Variables included are related to the care process, functionality, cognition and comorbidity, risk profile, nutritional status and dysphagia; as well as frailty, dietary quality and contextual variables. The incidence of risk of malnutrition, undernutrition and dysphagia during the care process and at discharge will be calculated. The association with risk factors will be studied with logistic regression models and multivariate Cox regression models. In addition, an analysis of participants' satisfaction with food services will be carried out. The study was approved by the Ethics and Research Committee on 30/09/2020, approved for funding on 02/12/2021 and with registration number RBR-5jnbyhk in the Brazilian clinical trials database (ReBEC) for observational studies. Discussion: Some studies address nutritional status or dysphagia in older people in various care settings. However, there is a lack of large sample studies including both processes of the impact of hospitalization. The results of the project will provide information on the incidence and prevalence of both pathologies in the study subjects, their associated factors and their relationship with the average length of stay, mortality and early readmission. In addition, early detection of a problem such as malnutrition related to the disease and/or dysphagia during a hospital stay will favor the action of professionals to resolve both pathologies and improve the health status of patients.This study has been funded by Instituto de Salud Carlos III (ISCIII) through the project "PI21/00738" and co-funded by the European Union. The funders did not and will not have a role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S
Repensando África: perspectivas desde un enfoque multidisciplinar
Beatriz Suárez Relinque y Susana Moreno Maestro (coords.)La presente publicación es una recopilación de algunas de las intervenciones que fueron realizadas durantes las jornadas "Repensando África: reflexiones desde un enfoque multidisciplinar" desarrolladas durante el mes de marzo de 2012 en Sevilla y Granada. Durante los días en que tuvieron lugar tuvimos la suerte de compartir enriquecedoras intervenciones personas provenientes de diferentes espacios -como movimientos sociales en África, universidades andaluzas, colectivos africanos en Andalucía y personas del mundo de la investigación- que abordaron reflexiones sobre el continente africano abordando cuestiones como las culturas, los feminismos, los recursos naturales, la economía, las migraciones, las relaciones de cooperación desde las universidades y desde otros actores, o las luchas y demandas de las organizaciones y sociedades africanas. Varias de dichas intervenciones se presentan como artículos en las siguientes páginas. Para completar la publicación se han sumado dos artículos realizados por alumnos de la Universidad de Sevilla como memoria final de las jornadas donde exponen sus reflexiones para contribuir a repensar África.Cette publication est un recueil de certaines des interventions prononcées durant les rencontres intitulées «Repenser l’Afrique. Réflexions sous un angle pluridisciplinaire», organisées en mars 2012 à Séville et à Grenade. Lors de ces journées, nous avons eu la chance d’assister à des interventions enrichissantes de personnes provenant de divers horizons – tels que les mouvements sociaux en Afrique, les universités andalouses, les collectifs africains en Andalousie et le monde de la recherche –, qui se sont livrées à des réflexions sur le continent africain, abordant des questions comme les cultures, les féminismes, les ressources naturelles, l’économie, les relations de coopération des universités et d’autres acteurs ou les luttes et les attentes des organisations et des sociétés africaines. Plusieurs de ces interventions sont présentées sous forme d’articles dans les pages suivantes. Pour compléter la publication, deux articles écrits par des étudiants de l’université de Séville constituent le mémoire final des journées, dans lequel exposent leurs réflexions pour contribuer à Repenser l’Afrique.Fundación Habitáfrica. Agencia Andaluza de Cooperación Internacional para el Desarrollo (AACID). Agencia Española de
Cooperación Internacional para el Desarrollo (AECID
Who are the visitors of the art museums: Particularities of the publics of the weekends at the Art Museum of Tigre (Argentina)
Saber quiénes son sus visitantes es una de las principales tareas de los museos en la actualidad, en la medida en que fluctúan entre ajustarse a las imposiciones del sistema capitalista y convertirse en instituciones democráticas y participativas. No obstante, este aspecto resulta aun más dificultoso en los museos de arte, en virtud de los atributos particulares de su estructura y actores. El presente trabajo tiene como objetivo aproximar algunos criterios que permitan conocer quiénes son los visitantes de los museos de arte creados en Argentina desde el inicio del nuevo milenio. Dada la magnitud del desafío, se procura, con el foco puesto en un caso particular, trazar algunos lineamientos sostenidos en los enfoques teórico-críticos aplicados a la museología y en los estudios de públicos. En cuanto a lo metodológico, se recurrió a un estudio de visitantes que apeló a orientaciones cuantitativas y cualitativas, realizado en el Museo de Arte de Tigre durante 2017, centrado en los públicos del fin de semana. Se considera que, al indagar los rasgos singulares de esta entidad patrimonial, pueden identificarse algunos indicios que permitan comenzar a trazar un perfil, tanto general como específico, de los visitantes de los museos de arte.Knowing who its visitors are is one of the main tasks of museums today, as they fluctuate between conforming to the impositions of the capitalist system and becoming democratic and participatory institutions. However, this aspect is even more difficult in the arts museums because of the particular attributes of their structure and its diverse actors. The present work has as main object to bring near some criteria that may allow to know who are the visitors of the art museums in Argentina since the beginning of the new millennium. Given the extent of the challenge, we’ll try, focusing in a particular case, draw some guidelines sustained in the theorical-critical approaches applied to museology and studies of the publics. In terms of methodology, a visitor study was carried out at the Tigre Art Museum in 2017, using both quantitative and qualitative guidelines, focusing on weekend audiences. It is considered that, when we question the singularities of this entity, there are some indications that a general and specific profile of visitors to art museums can begin to be identified.Saber quem são seus visitantes é uma das principais tarefas dos museus na atualidade, na medida em que flutuam entre amoldar-se às imposições do sistema capitalista e converter-se em instituições democráticas e participativas. Não obstante, este aspecto resulta ainda mais dificultoso nos museus de arte, devido aos atributos particulares de sua estrutura e atores. O presente trabalho tem por objetivo aproximar alguns critérios que permitam conhecer quem são os visitantes dos museus de arte criados na Argentina desde o início do novo milênio. Dada a magnitude do desafio, e com o foco posto em um caso particular, buscou-se traçar alguns lineamentos sustentados nos enfoques teórico-críticos aplicados à museologia e nos estudos de públicos. Quanto à metodologia, a pesquisa teve como base um estudo de visitantes que apelou a orientações quantitativas e qualitativas, realizado no Museu de Arte de Tigre durante o ano de 2017, focado nos públicos de fim de semana. Considera-se que, ao indagarmos os traços singulares desta entidade, podem ser identificados alguns indícios que permitam começar a esboçar um perfil, tanto geral quanto específico, dos visitantes dos museus de arte.Fil: Panozzo Zenere, Alejandra Gabriela. Universidad Nacional de Rosario. Facultad de Ciencias Políticas y Relaciones Internacionales. Instituto de Investigaciones. Centro de Investigaciones en Mediatizaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; Argentin
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