Decoding colouration of begging traits by the experimental addition of the appetite enhancer cyproheptadine hydrochloride in magpie (Pica pica) nestlings

Data available from the Dryad Digital Repository: (Martín-Gálvez and Soler 2016)The colouration of some traits in nestlings of altricial birds may influence parental food allocation as it may reflect physical condition or hunger. There is increasing evidence of the relationship between colouration of begging traits and nestling performance. However, evidence of the influence of hunger level on nestling colouration is scarce, mainly because of difficulty of distinguishing between the effects of physical condition and hunger levels. Here, we used the appetite stimulant cyproheptadine hydrochloride to increase the sensation of hunger of magpie Pica pica nestlings for eight days and assessed the effect on the colouration of rictal flanges, mouth and body skin. We found that nestlings administered with cyproheptadine had flanges more conspicuous (chromatic visual contrast), more UV coloured and less yellow coloured than their control nestmates. Conversely, mouths of experimental nestlings were more yellow coloured and less UV coloured than controls. Our pharmacological experiment afected the strength of the relationship between body mass and some colour components of body skin (chromatic and achromatic visual contrasts, UV – chroma and yellow – chroma) and of rictal flanges (chromatic visual contrasts, UV – chroma and yellow – chroma), but not for mouth colouration. These results taken together suggest that the effect of the cyproheptadine on nestling colourations is probably mediated by an increase in hunger levels of nestlings for rictal flanges and body skin colourations, and by an increase in physical condition in the case of mouth coloration.Th is research was funded by a postdoctoral fellowship to DM-G from Ministerio de Educación y Ciencia, and by Ministerio de Ciencia e Innovación/FEDER (project CGL2013-48193-C3-1-P)Peer reviewe

Intraspecific avian brood parasites avoid host nests infested by ectoparasites

Intraspecific brood parasitism is widespread among birds and provides clues for elucidating the evolutionary origin of interspecific brood parasitism. Studies suggest that brood parasitism does not occur at random, but that parasitic females select nests with advantages such as higher physical stability, reduced predation risk, or lower ectoparasite infestations. However, this evidence is sparse and mainly correlative. By experimentally increasing the abundance of Carnus hemapterus (a common, generalist and widespread ectoparasitic nest fly of a multitude of bird species) in half of the nests, we show that parasitic Spotless Starlings (Sturnus unicolor) avoid conspecific nests infested by ectoparasites. Since Carnus ectoparasites impinge costs on their avian nestling hosts, this avoidance response would be adaptive for parasitic Starlings. Further, we suggest a mechanism by which parasitic females may assess the level of ectoparasite infestation to select host nests accordingly: by using parasite cues such as faeces and blood remains. Additionally, these cues may be used by parasitic females for synchronization with the reproductive cycle of host females because ectoparasite cues also indicate that incubation has already commenced. Whatever the functionality, the mechanism suggested here may be employed by intra- and interspecific brood parasites, so it might represent a widespread strategy in nature.Financial support was provided by the Spanish Ministerio de Economía y Competitividad and FEDER (CGL2013- 48193-C3-1-P), the JAE programme to D. M. G. and M. R. R., and the Ramo´n y Cajal programme (Spain) and the Secretarı´a de Educacio ´n Superior, Ciencia, Tecnologı´a e Innovacio´n del Ecuador (SENESCYT) through a Prometeo research grant to G. TPeer 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

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

Effect of the temperature, strain rate and microstructure on flow and fracture characteristics of Ti-45Al-2Nb-2Mn+0.8vol.% TiB2 XD alloy

A series of quasi-static and dynamic tensile tests at varying temperatures were carried out to determine the mechanical behaviour of Ti-45Al-2Nb-2Mn+0.8vol.% TiB2 XD as-HIPed alloy. The temperature for the tests ranged from room temperature to 850  ∘C. The effect of the temperature on the ultimate tensile strength, as expected, was almost negligible within the selected temperature range. Nevertheless, the plastic flow suffered some softening because of the temperature. This alloy presents a relatively low ductility; thus, a low tensile strain to failure. The dynamic tests were performed in a Split Hopkinson Tension Bar, showing an increase of the ultimate tensile strength due to the strain rate hardening effect. Johnson-Cook constitutive relation was used to model the plastic flow. A post-testing microstructural of the specimens revealed an inhomogeneous structure, consisting of lamellar α2 + γ structure and γ phase equiaxed grains in the centre, and a fully lamellar structure on the rest. The assessment of the duplex-fully lamellar area ratio showed a clear relationship between the microstructure and the fracture behaviour

El peligro de las (in)definiciones: apuntes para un dosier sobre la "telebasura"

Toda definición supone en el fondo una cierta forma de res- tricción. Definir algo es, en esencia, dejar fuera de “lo defi- nido” todo lo que “por defecto” no es (ejemplo: definir “perro” implica dejar claras las diferencias que hay entre ese ani- mal y, pongamos por caso, un gato... o una silla, tanto da). En el tema de la bien o mal llamada “telebasura”, la mayor parte de los variados y vehementes intentos de dar(le) con una definición aceptable (e invariable) se han ido estrellando uno tras otro contra una realidad (teleinvasiva, en este caso) en constante mutación. Aparentemente, la “telebasura” es tan indefinible por ahora como lo fue en su día el ornitorrinco, esa broma pesada que Dios les gastó a los naturalistas. Perpetuum mobile en estado de recu- rrente hibridación intergenérica (la que va de los realities a deter- minados informativos), la “telebasura” ha terminado rentabilizan- do su propia (in)definición, saltando, trotona ella, del terreno vedado de los géneros y los formatos al campo (abierto y de bata- lla) de los contenidos éticos, los debates morales, la conveniencia política y la nece(si)dad empresarial. La “telebasura” ha dejado de ser un estilo de programa(ción) para convertirse, por derecho y vacío legal, en una forma de entender, afrontar, amortizar y tomarse el medio. Es por eso que hemos creído necesario incluir en este apresurado dossier un tan nutrido como nutritivo rosario de opiniones que, elaboradas a tal efecto y a modo de muestra in progress, intentan dar con una definición que, si bien no se pretende definitiva, sí que aspira al menos a acorralar momentáne- amente contra las cuerdas a tan escurridizo (por viscoso) concepto. Texto escrito por Fernado de Felipe

Bacterial density rather than diversity correlates with hatching success across different avian species

We thank Rosario Millán for technical assistance; Liesbeth de Neve, María Roldán, Juan Rodríguez-Ruiz, Deseada Parejo, Magdalena Ruiz-Rodríguez and Carlos Navarro for sampling nests of some species. We also thank the efforts and comments of two anonymous reviewers that have greatly improved the manuscript. Bird and egg manipulations were performed under the authorization of Junta de Andalucía - Consejería de Medio Ambiente (permit No. SGYB-AFR-CMM, February 19th 2007).Bacterial communities within avian nests are considered an important determinant of egg viability, potentially selecting for traits that confer embryos with protection against trans-shell infection. A high bacterial density on the eggshell increases hatching failure, whether this effect could be due to changes in bacterial community or just a general increase in bacterial density. We explored this idea using intra- and interspecific comparisons of the relationship between hatching success and eggshell bacteria characterized by culture and molecular techniques (fingerprinting and high-throughput sequencing). We collected information for 152 nests belonging to 17 bird species. Hatching failures occurred more frequently in nests with higher density of aerobic mesophilic bacteria on their eggshells. Bacterial community was also related to hatching success, but only when minority bacterial operational taxonomic units were considered. These findings support the hypothesis that bacterial density is a selective agent of embryo viability, and hence a proxy of hatching failure only within species. Although different avian species hold different bacterial densities or assemblages on their eggs, the association between bacteria and hatching success was similar for different species. This result suggests that interspecific differences in antibacterial defenses are responsible for keeping the hatching success at similar levels in different species.Funding was provided by Ministerio de Educación y Ciencia and European founds (FEDER) [CGL2007-61251, CGL2010-19233-C03- 01, CGL2010-19233-C03-03]. JMPS was funded by Ministerio de Educación and Consejería de Innovación, Ciencia y Empresa under International Excellence Campus Program, University of Granada (CEI Granada 2009). RK was supported in part by the Howard Hughes Medical Institute. The Earth Microbiome Project was supported in part by the John Templeton Foundation and the W.M. Keck Foundation

Brood parasitism is associated with increased bacterial contamination of host eggs: bacterial loads of host and parasitic eggs

Factors related to bacterial environment of nests are of primary interest for understanding the causes of embryo infection and the evolution of antimicrobial defensive traits in birds. Nest visitors such as parasites could act as vectors for bacteria and/or affect the hygienic conditions of nests and hence influence the nest bacterial environment. In the present study, we explored some predictions of this hypothetical scenario in the great spotted cuckoo (Clamator glandarius)-magpie (Pica pica) system of brood parasitism. Great spotted cuckoos visit the nests of their magpie hosts and frequently damage some of the host eggs when laying eggs or on subsequent visits. Therefore, it represents a good system for testing the effect of nest visitors on the bacterial environment of nests. In accordance with this hypothesis, we found that the bacterial load of magpie eggshells was greater in parasitized nests, which may suggest that brood parasitism increases the probability of bacterial infection of magpie eggs. Moreover, comparisons of bacterial loads of cuckoo and magpie eggs revealed that: (1) cuckoo eggshells harboured lower bacterial densities than those of their magpie hosts in the same nests and (2) the prevalence of bacteria inside unhatched eggs was higher for magpies than for great spotted cuckoos. These interspecific differences were predicted because brood parasitic eggs (but not host eggs) always experience the bacterial environments of parasitized nests. Therefore, the results obtained in the present study suggest that parasitic eggs are better adapted to environments with a high risk of bacterial contamination than those of their magpie hosts

Neurocognitive Function in Acromegaly after Surgical Resection of GH-Secreting Adenoma versus Naïve Acromegaly

Patients with active untreated acromegaly show mild to moderate neurocognitive disorders that are associated to chronic exposure to growth hormone (GH) and insulin-like growth factor (IGF-I) hypersecretion. However, it is unknown whether these disorders improve after controlling GH/IGF-I hypersecretion. The aim of this study was to compare neurocognitive functions of patients who successfully underwent GH-secreting adenoma transsphenoidal surgery (cured patients) with patients with naive acromegaly. In addition, we wanted to determine the impact of different clinical and biochemical variables on neurocognitive status in patients with active disease and after long-term cure. A battery of six standardized neuropsychological tests assessed attention, memory and executive functioning. In addition, a quantitative electroencephalography with Low-Resolution Electromagnetic Tomography (LORETA) solution was performed to obtain information about the neurophysiological state of the patients. Neurocognitive data was compared to that of a healthy control group. Multiple linear regression analysis was also conducted using clinical and hormonal parameters to obtain a set of independent predictors of neurocognitive state before and after cure. Both groups of patients scored significantly poorer than the healthy controls on memory tests, especially those assessing visual and verbal recall. Patients with cured acromegaly did not obtain better cognitive measures than naïve patients. Furthermore memory deficits were associated with decreased beta activity in left medial temporal cortex in both groups of patients. Regression analysis showed longer duration of untreated acromegaly was associated with more severe neurocognitive complications, regardless of the diagnostic group, whereas GH levels at the time of assessment was related to neurocognitive outcome only in naïve patients. Longer duration of post-operative biochemical remission of acromegaly was associated with better neurocognitive state. Overall, this data suggests that the effects of chronic exposure to GH/IGF-I hypersecretion could have long-term effects on brain functions. © 2013 Martín-Rodríguez et al.Funding for this project was provided by an R&D grant from Novartis Oncology and the Plan Andaluz de Investigación (CTS-444). DAC was supported by the “Ramón y Cajal” program (RYC-2006-001071) of the Spanish Ministry of Science and Innovation.Peer Reviewe

Booster effect after SARS-CoV-2 vaccination in immunocompromised hematology patients with prior COVID-19

Patients with hematological malignancies have been excluded from the new zoonotic coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) vaccine trials despite being at higher risk for SARS-CoV-2 disease (COVID-19)-related mortality. However, most health authorities worldwide have designated these patients as a priority for COVID-19 vaccination, even in the absence of efficacy data in these highly immunosuppressed patients. In addition, on 12 August 2021, the US Food and Drug Administration amended the emergency use authorizations for the Pfizer-BioNTech and Moderna COVID-19 vaccines to allow for the use of an additional dose in immunocompromised individuals, such as solid organ transplant recipients or equivalently immunosuppressed patients