Magnetic Bimerons in Cylindrical Nanotubes.

This work presents the analysis of the stability of magnetic bimerons in a cylindrical nanotube. Through micromagnetic simulations, we study the influence of magnetic and geometrical parameters on the bimeron existence and size. The obtained results allow us to present diagram states showing the stability region of a bimeron as a function of the nanotube's height and radius for different anisotropy and Dzyaloshinskii-Moriya interaction strengths. We also obtain two other magnetic states in the range of parameters where the bimeron is not stable: helicoidal and saturated states.

Diagnosis and Management of Postpartum Retroperitoneal Hematoma: A Report of 3 Cases.

BACKGROUND The retroperitoneal hematoma is a very rare entity in obstetrics. A type of obstetric hematoma that extends into the retroperitoneal space, this hematoma usually occurs after laceration of the uterine artery, after uterine rupture, or by extension of a vaginal hematoma. Although the hematoma usually manifests as intense abdominal pain, sometimes the clinical signs can go unnoticed. This is the main reason it is important to report the cases in which retroperitoneal hematomas occur. In addition to clinical suspicion, experience in management can also help improve maternal morbidity and mortality from this cause. CASE REPORT We present a series of 3 clinical cases in which retroperitoneal hematomas occurred after instrumental deliveries. The 3 clinical cases described took place before the COVID-19 pandemic. In the first 2 deliveries, a vacuum was used, while in the third delivery, spatulas were used. CONCLUSIONS Our findings showed that suspicion is essential in patients with symptoms of nonspecific pain, as well as in patients with anemia that causes hemodynamic instability in the immediate postpartum period. The use of early computed tomography angiography in hemodynamically stable patients is essential to reach a diagnosis and to determine if the patient can be treated by embolization of the bleeding vessel.

Differential elements of a successful agricultural innovation scaling-up model.

Worldwide, there is currently an increasing demand for an active connection between the generation of innovations and the achievement of their escalation. Between 2015 and 2018 the scaling up of three varieties of yellow potatoes was carried out in Colombia within the framework of the "More Nutritious Potatoes" project, which had results beyond the objectives and goals proposed in a period of 28 months. One of the results of the project was the design of a Scaling-up model of innovations that linked agriculture with nutrition. This article answers the question: Which were the elements of the scaling-up model that allowed the results obtained in the More Nutritious Potatoes Project? To respond, a set of reference criteria was constructed from the literature. These criteria were contrasted with the theoretical project scaling-up model and its subsequent implementation in the field, using focus groups as a methodology and the model design analysis and its execution by the leaders and the evaluator of the project. The project's Scaling-up Model (SM) was found to include all benchmarks, in addition to identify three key elements that made the results possible: (i) the characteristics of the innovation, (ii) the trans-disciplinary work and (iii) facilitating elements of the process. The results of this exercise complement the evaluated scaling-up model and become benchmarks in the design of innovation scaling-up processes.

The eggshell structure in apteryx; form, function, and adaptation.

Apteryx is a genus of flightless birds endemic to New Zealand known to lay very large eggs in proportion to body weight. The eggshell of Apteryx is unusually thin and less porous than allometrically expected possibly as a compensation for a very long incubation period. Past studies have been carried out on Apteryx australis, a species which once comprised all kiwi with brown plumage, now separated into three distinct species. These species use different habitats and live at different latitudes and altitudes, therefore generating a need to revise our knowledge of the attributes of their eggshells. In this study, we measured the physical characteristics and water conductance on eggshell fragments of these three species and Great-spotted Kiwi and relate them to the environmental conditions of their respective environments; we also measured the water vapor conductance of Brown Kiwi eggs of late stages of incubation. We found that several trade-offs exist between incubation behavior, environmental conditions, and eggshell structure. We found differences between species in eggshell water vapor conductance seemingly related to altitude; Brown Kiwi and Rowi generally inhabiting lower altitudes had the highest conductance and Tokoeka, generally living in montane environments, the lowest. This is achieved by an increased eggshell thickness rather than a pore area reduction. Finally, the water vapor conductance late in incubation was 58% higher than infertile unincubated eggs, suggesting a drastic increase in conductance throughout the long incubation period. Using the values previously reported, we calculated the embryonic eggshell thinning to be 32.5% at the equatorial region of the eggshell. We describe several new features, such as triangular mineral particles in the cuticle, reported for the extinct Trigonoolithus amoei, and confirmed the existence of plugged pores. We suggest that these structures provide microbial protection needed by a burrow nesting species with a long incubation period.

Challenges and Perspectives in the Epigenetics of Climate Change-Induced Forests Decline.

Forest tree species are highly vulnerable to the effects of climate change. As sessile organisms with long generation times, their adaptation to a local changing environment may rely on epigenetic modifications when allele frequencies are not able to shift fast enough. However, the current lack of knowledge on this field is remarkable, due to many challenges that researchers face when studying this issue. Huge genome sizes, absence of reference genomes and annotation, and having to analyze huge amounts of data are among these difficulties, which limit the current ability to understand how climate change drives tree species epigenetic modifications. In spite of this challenging framework, some insights on the relationships among climate change-induced stress and epigenomics are coming. Advances in DNA sequencing technologies and an increasing number of studies dealing with this topic must boost our knowledge on tree adaptive capacity to changing environmental conditions. Here, we discuss challenges and perspectives in the epigenetics of climate change-induced forests decline, aiming to provide a general overview of the state of the art.

Carcinoma basocelular umbilical en paciente con sospecha de endometriosis en la pared abdominal. Reporte de un caso y revisión bibliográfica / Umbilical basal cell carcinoma in a patient with suspected abdominal wall endometriosis. Case report and review of the literature

Resumen ANTECEDENTE: La endometriosis es una enfermedad inflamatoria que llega a afectar incluso a 15 a 44% de las mujeres fértiles; sin embargo, su localización en la pared abdominal es excepcional. Las diferentes lesiones que pueden encontrarse ahí dificultan el diagnóstico preoperatorio. OBJETIVOS: Reportar el caso de una paciente con carcinoma basocelular umbilical en quien se sospechó endometriosis en la pared abdominal y revisar la bibliografía al respecto, en particular la importancia del diagnóstico diferencial. CASO CLÍNICO: Paciente de 45 años con un carcinoma basocelular en torno de la zona umbilical. La situación anatómica y la induración dolorosa y sangrante en el área umbilical favorecieron un diagnóstico erróneo inicial de endometriosis umbilical. Esta tumoración, de un subtipo histológico de alto riesgo, requiere una técnica quirúrgica agresiva, con control de los márgenes afectados. En las revisiones posoperatorias la paciente permaneció asintomática, sin lesiones aparentes de recidiva. De la búsqueda bibliográfica se incluyeron 14 artículos de reportes de casos y revisiones de endometriosis en la pared abdominal y carcinoma basocelular. El acceso quirúrgico mediante la cirugía micrográfica de Mohs se estableció como el método más recomendado en la actualidad. CONCLUSIONES: La sospecha de endometriosis en la pared abdominal suele estar fundamentada en la aparición de una lesión con variaciones cíclicas sobre el lecho de una incisión quirúrgica. Las diferentes lesiones que pueden encontrarse en la pared abdominal dificultan el diagnóstico preoperatorio y solo el estudio histológico es el que finalmente lo establece.

Abstract BACKGROUND: Endometriosis is an inflammatory disease that affects up to 15-44% of fertile women, however its location at the level of the abdominal wall is a rare entity. The different lesions that can settle at this level make preoperative diagnosis difficult OBJECTIVES: To report the case of an umbilical basal cell carcinoma in a patient with suspected endometriosis of the abdominal wall and to review the literature, especially on the importance of differential diagnosis. CLINICAL CASE: A 45-year-old woman who presented a basal cell carcinoma at the umbilical level. The anatomical situation and the painful and bleeding induration at the umbilical level, led to an initial misdiagnosis of umbilical endometriosis. This tumor of a high-risk histological subtype requires optimal management, based on an aggressive surgical technique with control of the affected margins. In postoperative check-ups, the patient remains asymptomatic, with no apparent lesions of recurrence. A bibliographic search was carried out and 14 articles were included on case reports and literature reviews of abdominal wall endometriosis and basal cell carcinoma. The surgical approach using Mohs micrographic surgery has been established as the most recommended method at present. CONCLUSIONS: The suspicion of abdominal wall is usually based on the appearance of a lesion with cyclical variations on the bed of a surgical incision. The different lesions that can settle at the level of the abdominal wall make preoperative diagnosis difficult, with the histological study finally being the one that yields the definitive result.

Úlcera de Lipschütz: reporte de un caso y revisión bibliográfica / Lipschütz Ulcer: a case report and a literature review

Resumen: ANTECEDENTES: Las úlceras de Lipschütz son lesiones vulvovaginales dolorosas, de aparición aguda y desaparición espontánea en 2 a 6 semanas, no dejan secuelas ni son recurrentes a largo plazo. Su etiopatogenia es incierta, alrededor de 70% se consideran idiopáticas. En los estudios más recientes se ha demostrado su asociación con agentes infecciosos, sobre todo con el virus de Epstein-Barr. El diagnóstico se establece por exclusión y su tratamiento se basa en el control sintomático, cicatrizantes, analgésicos y antisépticos. CASO CLÍNICO: Paciente de 15 años, con úlceras vulvares de aparición súbita acompañadas de cuadro catarral. Se indicó tratamiento local con cicatrizante, antiséptico y antiinflamatorio; al cabo de tres semanas se observó la desaparición de las lesiones y la negatividad de las pruebas que descartó el origen infeccioso. Se estableció el diagnóstico de úlcera de Lipschütz. CONCLUSIONES: La úlcera de Lipschütz es infrecuente y los niños son quienes más la padecen. Debido al carácter de desaparición espontánea y a la juventud de las pacientes, es decisivo establecer el correcto diagnóstico diferencial.

Abstract: BACKGROUND: Lipschütz Ulcers are painful, acute onset and self-limiting vulvovaginal lesions that can frequently be associated with prodromal symptoms, disappearing in 2-6 weeks without any sequelae. 70% of cases present idiopathic etiopathogenesis, and are related to Epstein-Barr virus, among others. The diagnosis is made by exclusion and its treatment is based on symptomatic control and the promotion of correct healing, using analgesics, cicatrizers and antiseptics. CASE REPORT: A 15-year-old girl reported the acute apparition of ulcerative vulvar lesions coinciding with systemic catarrhal symptoms. Local treatment with healing, antiseptic and anti-inflammatory lotions was prescribed, and after three weeks, she was reevaluated, observing the disappearance of the lesions and the negativity of the tests to rule out infectious origin, for which she was diagnosed with a Lipschütz ulcer. CONCLUSIONS: Lipschütz ulcer is rare and children are the ones who suffer most from it. Due to the spontaneous disappearance character and the youthfulness of the patients, it is decisive to establish the correct differential diagnosis.

[Pathology of heart transplantation in peru: experience with 61 cases in a national reference center]. / Patología del trasplante cardiaco en el Perú: Experiencia con 61 casos en un centro de referencia nacional.

OBJETIVE.: To describe the histopathological characteristics of explanted hearts and post-transplant biopsy specimens at a national reference center in Peru. MATERIALS AND METHODS.: A case series study of patients who underwent heart transplantation between March 2010 and February 2018. RESULTS.: Sixty-one (61) transplanted patients with a mean age of 40.1 years (range: 9-66 years). Five cases (8.2%) initially diagnosed as dilated cardiomyopathy were reclassified after the histopathological study. The three leading causes of primary disease after transplantation were: idiopathic dilated cardiomyopathy (50.8%), ischemic cardiomyopathy (16.4%), and valvular cardiomyopathy (6.6%). The mean follow-up was 2.8 years. The post-transplant survival rate was 85.1% at 1 year and 82.8% at 5 years. Moderate/severe acute cellular rejection occurred in 12 patients (21.1%) and antibody-mediated rejection occurred in 3 patients (5.3%). CONCLUSIONS.: Routine histopathological evaluation of the explanted heart is essential to confirm the etiology of heart failure, especially in cases clinically diagnosed as dilated cardiomyopathy. In addition, routine follow-up through endomyocardial biopsies shows that acute cellular rejection is still a frequent complication after a heart transplant, especially within the first year, and that antibody-mediated rejection has a low incidence in our population.

OBJETIVOS: Describir las características histopatológicas de los explantes cardiacos y las biopsias endomiocárdicas postrasplante realizadas en un centro de referencia nacional del Perú. MATERIALES Y MÉTODOS.: Estudio de una serie de casos de pacientes sometidos a trasplante cardiaco entre marzo de 2010 y febrero de 2018. RESULTADOS.: Los 61 pacientes trasplantados, tuvieron un promedio de edad de 40,1 (rango: 9-66 años). Cinco casos (8,2%) diagnosticados inicialmente como miocardiopatía dilatada fueron reclasificados después del estudio histopatológico. Las tres primeras causas de enfermedad primaria previa al trasplante fueron: miocardiopatía dilatada idiopática (50,8%), cardiopatía isquémica (16,4%), y cardiopatía valvular (6,6%). El seguimiento promedio fue de 2,8 años. La tasa de supervivencia después del trasplante fue del 85,1% al año y del 82,8% a los cinco años. El rechazo celular agudo moderado/severo ocurrió en 12 pacientes (21,1%) y el rechazo mediado por anticuerpos ocurrió en tres pacientes (5,3%). CONCLUSIONES.: La evaluación histopatológica rutinaria del explante cardiaco es esencial para confirmar la etiología de la insuficiencia cardíaca, especialmente en los casos diagnosticados clínicamente como miocardiopatía dilatada. Asimismo, el seguimiento rutinario mediante biopsias endomiocárdicas muestra que el rechazo celular agudo continúa siendo una complicación frecuente durante el primer año de trasplante, y que el rechazo mediado por anticuerpos tiene una baja frecuencia en nuestra población.

Patología del trasplante cardiaco en el Perú: Experiencia con 61 casos en un centro de referencia nacional / Pathology of heart transplantation in peru: experience with 61 cases in a national reference center

RESUMEN. Objetivos Describir las características histopatológicas de los explantes cardiacos y las biopsias endomiocárdicas postrasplante realizadas en un centro de referencia nacional del Perú. Materiales y métodos. Estudio de una serie de casos de pacientes sometidos a trasplante cardiaco entre marzo de 2010 y febrero de 2018. Resultados. Los 61 pacientes trasplantados, tuvieron un promedio de edad de 40,1 (rango: 9-66 años). Cinco casos (8,2%) diagnosticados inicialmente como miocardiopatía dilatada fueron reclasificados después del estudio histopatológico. Las tres primeras causas de enfermedad primaria previa al trasplante fueron: miocardiopatía dilatada idiopática (50,8%), cardiopatía isquémica (16,4%), y cardiopatía valvular (6,6%). El seguimiento promedio fue de 2,8 años. La tasa de supervivencia después del trasplante fue del 85,1% al año y del 82,8% a los cinco años. El rechazo celular agudo moderado/severo ocurrió en 12 pacientes (21,1%) y el rechazo mediado por anticuerpos ocurrió en tres pacientes (5,3%). Conclusiones. La evaluación histopatológica rutinaria del explante cardiaco es esencial para confirmar la etiología de la insuficiencia cardíaca, especialmente en los casos diagnosticados clínicamente como miocardiopatía dilatada. Asimismo, el seguimiento rutinario mediante biopsias endomiocárdicas muestra que el rechazo celular agudo continúa siendo una complicación frecuente durante el primer año de trasplante, y que el rechazo mediado por anticuerpos tiene una baja frecuencia en nuestra población.

ABSTRACT Objetive. To describe the histopathological characteristics of explanted hearts and post-transplant biopsy specimens at a national reference center in Peru. Materials and Methods. A case series study of patients who underwent heart transplantation between March 2010 and February 2018. Results. Sixty-one (61) transplanted patients with a mean age of 40.1 years (range: 9-66 years). Five cases (8.2%) initially diagnosed as dilated cardiomyopathy were reclassified after the histopathological study. The three leading causes of primary disease after transplantation were: idiopathic dilated cardiomyopathy (50.8%), ischemic cardiomyopathy (16.4%), and valvular cardiomyopathy (6.6%). The mean follow-up was 2.8 years. The post-transplant survival rate was 85.1% at 1 year and 82.8% at 5 years. Moderate/severe acute cellular rejection occurred in 12 patients (21.1%) and antibody-mediated rejection occurred in 3 patients (5.3%). Conclusions. Routine histopathological evaluation of the explanted heart is essential to confirm the etiology of heart failure, especially in cases clinically diagnosed as dilated cardiomyopathy. In addition, routine follow-up through endomyocardial biopsies shows that acute cellular rejection is still a frequent complication after a heart transplant, especially within the first year, and that antibody-mediated rejection has a low incidence in our population.

Repeat associated mechanisms of genome evolution and function revealed by the Mus caroli and Mus pahari genomes.

Understanding the mechanisms driving lineage-specific evolution in both primates and rodents has been hindered by the lack of sister clades with a similar phylogenetic structure having high-quality genome assemblies. Here, we have created chromosome-level assemblies of the Mus caroli and Mus pahari genomes. Together with the Mus musculus and Rattus norvegicus genomes, this set of rodent genomes is similar in divergence times to the Hominidae (human-chimpanzee-gorilla-orangutan). By comparing the evolutionary dynamics between the Muridae and Hominidae, we identified punctate events of chromosome reshuffling that shaped the ancestral karyotype of Mus musculus and Mus caroli between 3 and 6 million yr ago, but that are absent in the Hominidae. Hominidae show between four- and sevenfold lower rates of nucleotide change and feature turnover in both neutral and functional sequences, suggesting an underlying coherence to the Muridae acceleration. Our system of matched, high-quality genome assemblies revealed how specific classes of repeats can play lineage-specific roles in related species. Recent LINE activity has remodeled protein-coding loci to a greater extent across the Muridae than the Hominidae, with functional consequences at the species level such as reproductive isolation. Furthermore, we charted a Muridae-specific retrotransposon expansion at unprecedented resolution, revealing how a single nucleotide mutation transformed a specific SINE element into an active CTCF binding site carrier specifically in Mus caroli, which resulted in thousands of novel, species-specific CTCF binding sites. Our results show that the comparison of matched phylogenetic sets of genomes will be an increasingly powerful strategy for understanding mammalian biology.

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

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.

Genome variation and conserved regulation identify genomic regions responsible for strain specific phenotypes in rat.

BACKGROUND: The genomes of laboratory rat strains are characterised by a mosaic haplotype structure caused by their unique breeding history. These mosaic haplotypes have been recently mapped by extensive sequencing of key strains. Comparison of genomic variation between two closely related rat strains with different phenotypes has been proposed as an effective strategy for the discovery of candidate strain-specific regions involved in phenotypic differences. We developed a method to prioritise strain-specific haplotypes by integrating genomic variation and genomic regulatory data predicted to be involved in specific phenotypes. Specifically, we aimed to identify genomic regions associated with Metabolic Syndrome (MetS), a disorder of energy utilization and storage affecting several organ systems. RESULTS: We compared two Lyon rat strains, Lyon Hypertensive (LH) which is susceptible to MetS, and Lyon Low pressure (LL), which is susceptible to obesity as an intermediate MetS phenotype, with a third strain (Lyon Normotensive, LN) that is resistant to both MetS and obesity. Applying a novel metric, we ranked the identified strain-specific haplotypes using evolutionary conservation of the occupancy three liver-specific transcription factors (HNF4A, CEBPA, and FOXA1) in five rodents including rat. Consideration of regulatory information effectively identified regions with liver-associated genes and rat orthologues of human GWAS variants related to obesity and metabolic traits. We attempted to find possible causative variants and compared them with the candidate genes proposed by previous studies. In strain-specific regions with conserved regulation, we found a significant enrichment for published evidence to obesity-one of the metabolic symptoms shown by the Lyon strains-amongst the genes assigned to promoters with strain-specific variation. CONCLUSIONS: Our results show that the use of functional regulatory conservation is a potentially effective approach to select strain-specific genomic regions associated with phenotypic differences among Lyon rats and could be extended to other systems.

A multi-species synthesis of physiological mechanisms in drought-induced tree mortality.

Widespread tree mortality associated with drought has been observed on all forested continents and global change is expected to exacerbate vegetation vulnerability. Forest mortality has implications for future biosphere-atmosphere interactions of carbon, water and energy balance, and is poorly represented in dynamic vegetation models. Reducing uncertainty requires improved mortality projections founded on robust physiological processes. However, the proposed mechanisms of drought-induced mortality, including hydraulic failure and carbon starvation, are unresolved. A growing number of empirical studies have investigated these mechanisms, but data have not been consistently analysed across species and biomes using a standardized physiological framework. Here, we show that xylem hydraulic failure was ubiquitous across multiple tree taxa at drought-induced mortality. All species assessed had 60% or higher loss of xylem hydraulic conductivity, consistent with proposed theoretical and modelled survival thresholds. We found diverse responses in non-structural carbohydrate reserves at mortality, indicating that evidence supporting carbon starvation was not universal. Reduced non-structural carbohydrates were more common for gymnosperms than angiosperms, associated with xylem hydraulic vulnerability, and may have a role in reducing hydraulic function. Our finding that hydraulic failure at drought-induced mortality was persistent across species indicates that substantial improvement in vegetation modelling can be achieved using thresholds in hydraulic function.

The Life Cycle of Engineered Nanoparticles.

The first years in the twenty-first century have meant the inclusion of nanotechnology in most industrial sectors, from very specific sensors to construction materials. The increasing use of nanomaterials in consumer products has raised concerns about their potential risks for workers, consumers and the environment. In a comprehensive risk assessment or life cycle assessment, a life cycle schema is the starting point necessary to build up the exposure scenarios and study the processes and mechanisms driving to safety concerns. This book chapter describes the processes that usually occur at all the stages of the life cycle of the nano-enabled product, from the nanomaterial synthesis to the end-of-life of the products. Furthermore, release studies reported in literature related to these processes are briefly discussed.

Muscle MRI in pediatrics: clinical, pathological and genetic correlation.

Pediatric myopathies comprise a very heterogeneous group of disorders that may develop at different ages and affect different muscle groups. Its diagnosis is sometimes difficult and must be confirmed by muscle biopsy and/or genetic analysis. In recent years, muscle involvement patterns observed on MRI have become a valuable tool, aiding clinical diagnosis and enriching pathological and genetic assessments. We selected eight myopathy cases from our institutional database in which the pattern of muscle involvement observed on MRI was almost pathognomonic and could therefore contribute to establishing diagnosis. Muscle biopsy, genetic diagnosis or both confirmed all cases.

Influence of Nanomaterial Compatibilization Strategies on Polyamide Nanocomposites Properties and Nanomaterial Release during the Use Phase.

The incorporation of small amounts of nanofillers in polymeric matrices has enabled new applications in several industrial sectors. The nanofiller dispersion can be improved by modifying the nanomaterial (NM) surface or predispersing the NMs to enhance compatibility. This study evaluates the effect of these compatibilization strategies on migration/release of the nanofiller and transformation of polyamide-6 (PA6), a thermoplastic polymer widely used in industry during simulated outdoors use. Two nanocomposites (NCs) containing SiO2 nanoparticles (NPs) with different surface properties and two multiwalled carbon nanotube (MWCNT) NCs obtained by different addition methods were produced and characterized, before and after accelerated wet aging conditions. Octyl-modified SiO2 NPs, though initially more aggregated than uncoated SiO2 NPs, reduced PA6 hydrolysis and, consequently, NM release. Although no clear differences in dispersion were observed between the two types of MWCNT NCs (masterbatch vs direct addition) after manufacture, the use of the MWCNT masterbatch reduced PA6 degradation during aging, preventing MWCNT accumulation on the surface and further release or potential exposure by direct contact. The amounts of NM released were lower for MWCNTs (36 and 108 mg/m(2)) than for SiO2 NPs (167 and 730 mg/m(2)), being lower in those samples where the NC was designed to improve the nanofiller-matrix interaction. Hence, this study shows that optimal compatibilization between NM and matrix can improve NC performance, reducing polymer degradation and exposure and/or release of the nanofiller.

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.

A long-term experimental study demonstrates the costs of begging that were not found over the short term.

Parent-offspring conflict theory predicts that begging behaviour could escalate continuously over evolutionary time if it is not prevented by costliness of begging displays. Three main potential physiological costs have been proposed: growth, immunological and metabolic costs. However, empirical evidence on this subject remains elusive because published results are often contradictory. In this study, we test for the existence of these three potential physiological costs of begging in house sparrow (Passer domesticus) nestlings by stimulating a group of nestlings to beg for longer and another group for shorter periods than in natural conditions. All nestlings were fed with the same quantity of food. Our study involves a long-term experimental treatment for begging studies (five consecutive days). Long-term studies frequently provide clearer results than short-term studies and, sometimes, relevant information not reported by the latter ones. Our long-term experiment shows (i) a clear effect on the immune response even since the first measurement (6 hours), but it was higher during the second (long-term) than during the first (short-term) test; (ii) evidence of a growth cost of begging in house sparrow nestlings not previously found by other studies; (iii) body condition was affected by our experimental manipulation only after 48 hour; (iv) a metabolic cost of begging never previously shown in any species, and (v) for the first time, it has shown a simultaneous effect of the three potential physiological costs of begging: immunocompetence, growth, and metabolism. This implies first, that a multilevel trade-off can occur between begging and all physiological costs and, second, that a lack of support in a short-term experiment for the existence of a tested cost of begging does not mean absence of that cost, because it can be found in a long-term experiment.

Resource availability and repeated defoliation mediate compensatory growth in trembling aspen (Populus tremuloides) seedlings.

Plant ecologists have debated the mechanisms used by plants to cope with the impact of herbivore damage. While plant resistance mechanisms have received much attention, plant compensatory growth as a type of plant tolerance mechanisms has been less studied. We conducted a greenhouse experiment to evaluate compensatory growth for trembling aspen (Populus tremuloides) seedlings under varying intensities and frequencies of simulated defoliation, with or without nutrient enriched media. For the purpose of this study, changes in biomass production and non-structural carbohydrate concentrations (NSC) of roots and leaves were considered compensatory responses. All defoliated seedlings showed biomass accumulation under low defoliation intensity and frequency, regardless of resource availability; however, as defoliation intensity and frequency increased, compensatory growth of seedlings was altered depending on resource availability. Seedlings in a resource-rich environment showed complete compensation, in contrast responses ranged from undercompensation to complete compensation in a resource-limited environment. Furthermore, at the highest defoliation intensity and frequency, NSC concentrations in leaves and roots were similar between defoliated and non-defoliated seedlings in a resource-rich environment; in contrast, defoliated seedlings with limited resources sustained the most biomass loss, had lower amounts of stored NSC. Using these results, we developed a new predictive framework incorporating the interactions between frequency and intensity of defoliation and resource availability as modulators of plant compensatory responses.

Cuckoo hosts shift from accepting to rejecting parasitic eggs across their lifetime.

One of the best-known outcomes of coevolution between species is the rejection of mimetic parasite eggs by avian hosts, which has evolved to reduce costly cuckoo parasitism. How this behavioral adaptation varies along the life of individual hosts remains poorly understood. Here, we identify for the first time, lifetime patterns of egg rejection in a parasitized long-lived bird, the magpie Pica pica and show that, during the years they were studied, some females accept, others reject, and some others modify their response to model eggs, in all cases switching from acceptance to rejection. Females tested in their first breeding attempt always accepted the model egg, even those individuals whose mothers were egg rejecters. A longitudinal analysis showed that the probability of egg rejection increased with the relative age of the female, but was not related to the risk of parasitism in the population. We conclude that ontogeny plays a fundamental role in the process leading to egg rejection in magpies.