Morphological changes in the anterior vaginal wall caused by aging: a scanning electron microscopy study.

INTRODUCTION AND HYPOTHESIS: Collagen is a protein that confers robustness and resilience to several tissues. In the female reproductive system, collagen plays a critical role in maintaining the health and function of the vaginal walls. Aging leads to collagen reduction, which may cause vaginal dryness, irritation, and prolapse. We aim to analyze the structure and profile of collagen in the anterior vaginal wall of healthy pre-menopausal (pre-M) and post-menopausal (post-M) women under a scanning electron microscope (SEM). METHODS: Fragments of the anterior vaginal wall were collected and processed for light and scanning electron microscopy. Histological preparations were performed at first with Weigert's resorcin-fuchsin stain. Decellularized preparations were conducted, and the specimens were placed under an SEM to allow observation of the 3D organization of collagen. RESULTS: Decellularized preparations of the pre-M specimens showed a vaginal wall with an irregular subepithelial layer, organized with ECM projections. The subepithelium evidenced the network of collagen fibrils, which seemed to support the epithelium as a basal layer. In specimens of post-M, a fusion of a network of fibrils from different direction axes was evidenced, with plate formation observed in the subepithelial plane, disfiguring the structural organization of fibrils. CONCLUSIONS: Older specimens showed a remodeling of collagen organization in comparison with younger samples of the anterior vaginal wall.

Testing differences of marine non-indigenous species diversity across Macaronesia using a standardised approach.

The introduction of non-indigenous species (NIS) induces severe impacts on marine biodiversity and ecosystems. Macaronesia is an ecologically relevant region where several NIS were detected recently. For the first time, a standard experimental approach was designed to examine biofouling assemblages and investigate NIS across the region. In this context, sessile biofouling assemblages were examined in four recreational marinas in all the Macaronesian archipelagos from 2018 to 2020: the Azores, Madeira, Canary Islands, and Cabo Verde. We hypothesised that NIS numbers, abundance, and recruitment differed in each location due to abiotic and biotic features. From the Azores (higher latitudes) to Cabo Verde (lower latitudes), NIS recruitment and percentage cover decreased following a partial latitude gradient. The present study unveiled 25 NIS, with new records for the Azores (two cryptogenic species), Canary Islands (one NIS and two cryptogenic species), and Cabo Verde (three NIS and three cryptogenic species). The present research represents a pioneer and relevant step in advancing our current understanding of marine biological invasions in Macaronesia, employing a standard and low-cost approach.

Trust your guts? The effect of gut section on diet composition and impact of Mus musculus on islands using metabarcoding.

DNA metabarcoding is widely used to characterize the diet of species, and it becomes very relevant for biodiversity conservation, allowing the understanding of trophic chains and the impact of invasive species. The need for cost-effective biodiversity monitoring methods fostered advances in this technique. One question that arises is which sample type provides a better diet representation.Therefore, with this study, we intended to evaluate if there were differences in diet estimates according to the section of the gastrointestinal tract analysed and which section(s) provided the best diet representation. Additionally, we intended to infer the ecological/economic impacts of an invader as a model of the potential effects in an originally mammal-free ecosystem.We examined the gut contents of the house mouse Mus musculus introduced to Cabo Verde, considering three sections: stomach, small intestine, and large intestine. We applied a DNA-metabarcoding approach using two genetic markers, one specific for plants and another for invertebrates.We showed that this invader consumed 131 taxa (73 plants and 58 invertebrates). We obtained significant differences in the composition of two of the three sections, with a higher incidence of invertebrates in the stomach and plants in the intestines. This may be due to stomach inhibitors acting on plants and/or to faster absorption of soft-body invertebrates compared to the plant fibers in the intestines. We verified that the impact of this invader in the ecosystem is predominantly negative, as at least 50% of the ingested items were native, endemic, or economically important taxa, and only 19% of the diet items were exotics.Overall, results showed the need to analyse only two gastrointestinal tract sections to obtain robust diet data, increasing the cost-effectiveness of the method. Furthermore, by uncovering the native taxa most frequently preyed on by mice, this DNA-metabarcoding approach allowed us to evaluate efficiently which are at the highest risk.

O metabarcoding de ADN é amplamente utilizado para a caracterização da dieta de espécies, e tornou­se bastante relevante para a conservação da biodiversidade, permitindo a compreensão sobre cadeias tróficas e o impacto de espécies invasoras. A necessidade de métodos de monitorização da biodiversidade com uma boa relação custo­benefício fomentaram avanços nesta técnica. Uma questão que se coloca é qual o tipo de amostra que fornece uma melhor representação da dieta. Deste modo, com este estudo, pretendemos avaliar se existem diferenças nas estimativas da dieta de acordo com a secção do tracto gastrointestinal analisada e qual(is) a(s) secção(ões) que proporciona(m) uma melhor representação da dieta. Adicionalmente, pretendemos inferir os impactos ecológicos/ económicos de um invasor como um modelo dos efeitos potenciais que este pode ter num ecossistema originalmente sem mamíferos. Analisámos os conteúdos gastrointestinais do rato doméstico Mus musculus introduzido em Cabo Verde, considerando três secções: estômago, intestino delgado e intestino grosso. Aplicámos uma abordagem de metabarcoding de ADN usando dois marcadores genéticos, um específico para plantas e outro para invertebrados. Mostrámos que este invasor consumiu 131 taxa (73 plantas e 58 invertebrados). Obtivemos diferenças significativas na composição de duas das três secções, com maior incidência de invertebrados no estômago e de plantas nos intestinos. Isto pode dever­se a inibidores estomacais que agem sobre as plantas e/ ou à absorção mais rápida de invertebrados de corpo mole em comparação com as fibras vegetais nos intestinos. Verificámos que o impacto deste invasor no ecossistema é predominantemente negativo, pois pelo menos 50% dos itens ingeridos eram nativos, endémicos ou economicamente importantes e apenas 19% dos itens da dieta eram exóticos. De modo geral, os resultados mostraram a necessidade de analisar apenas duas secções do tracto gastrointestinal para obter dados robustos da dieta, aumentando a relação custo­eficácia deste método. Além disso, ao descobrir os taxa nativos mais frequentemente predados por ratos, a abordagem de metabarcoding de ADN permitiu­nos avaliar com eficiência quais estão sob maior risco.

Insular geckos provide experimental evidence on refuge selection priorities by ectotherms.

In small sedentary ectotherms, patterns of spatial use result from the interplay between multiple, often conflicting factors, including abiotic and biotic interactions. Evaluating the costs and benefits of these pressures is crucial to make correct behavioural decisions in terms of fitness. The insular São Vicente's wall gecko Tarentola substituta provides a relatively simple model system to study these questions as it inhabits arid rocky habitats where refuges are limited, density of conspecifics is high, and terrestrial predators are almost absent. In the field, adults tend to find diurnal shelter under mid-sized rocks, frequently in male-female couples, while juveniles occupy small rocks which are thermally suboptimal. A lab experiment was conducted to determine the roles of ecological (shelter size and temperature) and social (conspecifics) factors in refuge selection. Single and pair combinations of geckos of different age and sex classes were allowed to select among four refuges: cold small, hot small, cold large, or hot large rock. Based on previous studies, we hypothesized that larger and thermally buffered rocks would be the preferred refuges, and that adult male-female pairs under the same rock would be more frequent than other combinations.Geckos primarily selected larger shelters, trading off the presence of conspecifics against thermal quality. In social terms, sex, adult condition and size-related disparity shaped the patterns of aggregation, resulting in lower aggregation frequencies between adults and juveniles and even between juveniles of different sizes. These results reasonably match field observations suggesting selection of rocks as diurnal retreats according to their thermal properties, and social aggregations mainly involving adult males and females but not juveniles. Overall, this combined evidence provides insights on the spatial ecology of geckos, and likely other ectotherms, under conditions of low predation, limited resources and high intraspecific competition, such as those prevailing on island systems.

Evaluating the emissions from the gasification processing of municipal solid waste followed by combustion.

In this study, we evaluated the emissions of pollutants generated from the combustion of syngas in the gasification of Municipal Solid Waste (MSW) in Brazil using a mobile grille gasifier fed with domestic waste without any previous separation or grinding. The basic syngas composition (H2, CH4 and CO) was analyzed by gas chromatography and the Lower Calorific Value was calculated, which ranged from 1.9 to 10.2 MJ/kg. In the monitoring of combustion gases (CO2, CO, NO, NO2, SO2 and Total Hydrocarbon Content), values were found for these pollutants that were lower than the values established by the Brazilian legislation, except for SO2. Regarding the determination of the emission of metals, values lower than those permissible in the legislation were found for the most toxic metals grouped as class I (Cd, Hg, Tl). Therefore, it was evident that gasification followed by the combustion of syngas from MSW without prior segregation at source has the advantages of having fewer process steps, allowing the low emission of pollutants into the environment and it avoids that the residues are deposited in landfills, which are generators of leachate and greenhouse gas (methane).

Drivers of Cape Verde archipelagic endemism in keyhole limpets.

Oceanic archipelagos are the ideal setting for investigating processes that shape species assemblages. Focusing on keyhole limpets, genera Fissurella and Diodora from Cape Verde Islands, we used an integrative approach combining molecular phylogenetics with ocean transport simulations to infer species distribution patterns and analyse connectivity. Dispersal simulations, using pelagic larval duration and ocean currents as proxies, showed a reduced level of connectivity despite short distances between some of the islands. It is suggested that dispersal and persistence driven by patterns of oceanic circulation favouring self-recruitment played a primary role in explaining contemporary species distributions. Mitochondrial and nuclear data revealed the existence of eight Cape Verde endemic lineages, seven within Fissurella, distributed across the archipelago, and one within Diodora restricted to Boavista. The estimated origins for endemic Fissurella and Diodora were 10.2 and 6.7 MY, respectively. Between 9.5 and 4.5 MY, an intense period of volcanism in Boavista might have affected Diodora, preventing its diversification. Having originated earlier, Fissurella might have had more opportunities to disperse to other islands and speciate before those events. Bayesian analyses showed increased diversification rates in Fissurella possibly promoted by low sea levels during Plio-Pleistocene, which further explain differences in species richness between both genera.

An ecophysiological background for biogeographic patterns of two island lizards?

Distributions of sedentary ectotherms are dependent on temperature and humidity due to their low homeostatic and dispersal abilities. Lizards are strongly conditioned by temperature, but hydric environment may be also important, at least in arid environments. Biotic interactions may also play a role in range patterns, but they are of minor importance in islands where native species monopolize well-delimited niche spaces. On the arid island of São Vicente (Cabo Verde), two endemic lizards display different spatial patterns. While the gecko Tarentola substituta is widely distributed across the island, the skink Chioninia stangeri is restricted to the NE, which is cooler, more humid, and vegetated. We hypothesized that this is due to differences in the fundamental niche, specifically in ecophysiology. We predict that C. stangeri should select for lower temperatures and lose more water by evaporation than T. substituta. We submitted adults of each species to standard experiments to assess preferred body temperatures (Tp) and evaporative water loss (EWL) rates, and examined the variation between species and through time using repeated-measures AN(C)OVAs. Results only partially supported our expectations. Contrary to the prediction, skinks attained higher Tp than geckos but in the long term showed a trend for higher EWL as predicted. Thus, while ecophysiology certainly contributes to functional interpretation of species distributions, it needs to be combined with other evidence such as habitat use and evolutionary history. These findings will be useful to perform mechanistic models to better understand the impact of climate change and habitat disturbance on these endemic species.

Expression of Genes by Aflatoxigenic and Nonaflatoxigenic Strains of Aspergillus flavus Isolated from Brazil Nuts.

The aims of the present study were to monitor the production of aflatoxin B1 (AFB1) and mycelial growth, and to evaluate the expression of genes directly and indirectly involved in the biosynthesis of aflatoxins by Aspergillus flavus isolated from Brazil nuts. Six previously identified A. flavus strains were grown on coconut agar at 25°C for up to 10 days. Mycotoxins were separated by high-performance liquid chromatography and fungal growth was measured daily using the diametric mycelial growth rate. Transcriptional analysis was performed by real-time polymerase chain reaction (PCR) after 2 and 7 d of incubation using specific primers (aflR, aflD, aflP, lipase, metalloprotease, and LaeA). Three (50%) of the six A. flavus isolates produced AFB1 (ICB-1, ICB-12, and ICB-54) and three (50%) were not aflatoxigenic (ICB-141, ICB-161, and ICB-198). Aflatoxin production was observed from d 2 of incubation (1.5 ng/g for ICB-54) and increased gradually with time of incubation until d 10 (15,803.6 ng/g for ICB-54). Almost all A. flavus isolates exhibited a similar gene expression pattern after 2 d of incubation (p > 0.10). After 7 d of incubation, the LaeA (p < 0.05) and metalloprotease (p < 0.05) genes were the most expressed by nonaflatoxigenic strains, whereas aflatoxigenic isolates exhibited higher expression of the aflR (p < 0.05) and aflD genes (p < 0.05). Our results suggest that the expression of aflR and aflD is correlated with aflatoxin production in A. flavus and that overexpression of aflR could affect the transcriptional and aflatoxigenic pattern (ICB-54). Elucidation of the molecular mechanisms that regulate the secondary metabolism of toxigenic fungi may permit the rational silencing of the genes involved and consequently the programmed inhibition of aflatoxin production. Knowledge of the conditions, under which aflatoxin genes are expressed, should contribute to the development of innovative and more cost-effective strategies to reduce and prevent aflatoxin contamination in Brazil nuts.

Molecular and mycotoxigenic biodiversity of Aspergillus flavus isolated from Brazil nuts.

The objective of this study was to carry out a transcription analysis of eight genes belonging to the aflatoxin (AF) and cyclopiazonic acid (CPA) biosynthesis pathway, and to detect aflatoxin B1 (AFB1) and CPA production in Aspergillus flavus strains isolated from Brazil nuts. Additionally, these genes were correlated with the different mycotoxigenic profiles of the same strains. Four previously identified A. flavus strains (ICB-01, ICB-151, ICB-161, and ICB-165) were grown on Brazil nut agar at 25°C for 10days. Mycotoxins were separated by high-performance liquid chromatography. Transcriptional analysis was performed by real-time RT-PCR using specific primers designed based on the conserved regions of two regulatory genes (aflR and aflS), three structural genes of the AFB1 biosynthesis pathway (aflH, aflJ and aflP), and three structural genes of the CPA biosynthesis pathway (maoA, dmaT and pks-nrps). The expression of most genes in the A. flavus isolates varied according to the mycotoxin profile of each strain. The most expressed genes in the aflatoxigenic strain ICB-151 were aflJ (77.11%) and aflH (32.75%), while the CPA-producing strain ICB-161 mainly expressed dmaT (100%), maoA (63.72%), aflS (43.52%), and aflR (42.63%). The ICB-01 isolate was a producer of AFB1 and CPA and the most expressed genes were aflS (47.79%), dmaT (42.77%), aflP (39.5%), and aflR (38.02%). ICB-198 did not produce any mycotoxin and exhibited lower expression of almost all genes analyzed. Furthermore, the ratio of aflS/aflR expression was correlated with the biosynthesis of AF and CPA in A. flavus strains producing exclusively AF or CPA or producing both AF and CPA. The ratio of aflS/aflR expression therefore seems to be related to the production of mycotoxins in Brazil nuts. Our results provide important data for the development of innovative and more cost-effective strategies to reduce and prevent AFB and CPA contamination in Brazil nuts.

Phylogeography of a Marine Insular Endemic in the Atlantic Macaronesia: The Azorean Barnacle, Megabalanus azoricus (Pilsbry, 1916).

The Azorean barnacle, Megabalanus azoricus (Pilsbry, 1916), is a Macaronesian endemic whose obscure taxonomy and the unknown relationships among forms inhabiting isolated Northern Atlantic oceanic islands is investigated by means of molecular analysis herein. Mitochondrial data from the 16S rRNA and COX1 genes support its current species status, tropical ancestry, and the taxonomic homogeneity throughout its distribution range. In contrast, at the intraspecific level and based on control region sequences, we detected an overall low level of genetic diversity and three divergent lineages. The haplogroups α and γ were sampled in the Azores, Madeira, Canary, and Cabo Verde archipelagos; whereas haplogroup ß was absent from Cabo Verde. Consequently, population analysis suggested a differentiation of the Cabo Verde population with respect to the genetically homogenous northern archipelagos generated by current oceanographic barriers. Furthermore, haplogroup α, ß, and γ demographic expansions occurred during the interglacial periods MIS5 (130 Kya - thousands years ago -), MIS3 (60 Kya), and MIS7 (240 Kya), respectively. The evolutionary origin of these lineages is related to its survival in the stable southern refugia and its demographic expansion dynamics are associated with the glacial-interglacial cycles. This phylogeographic pattern suggests the occurrence of genetic discontinuity informative to the delimitation of an informally defined biogeographic entity, Macaronesia, and its generation by processes that delineate genetic diversity of marine taxa in this area.