Trajetórias de adolescentes que vivem com o vírus HIV por transmissão vertical / Trajectories of adolescents living with vertical transmission-HIV virus

Resumo Este estudo analisa as histórias de vida de oito jovens vivendo com HIV por transmissão vertical, visando compreender suas percepções marcadas pelo segredo e silêncio sobre suas vivências com o vírus. Realizado em ambulatório especializado no Rio de Janeiro, o estudo adotou como ferramenta de cuidado a dança circular, considerada uma Prática Integrativa e Complementar em Saúde. Utilizando abordagem qualitativa e a História de Vida como método de coleta, o foco foi compreender as experiências dos jovens, não apenas relacionadas à doença, mas também a aspectos cruciais de suas vidas. Participaram do estudo três meninas e cinco meninos, todos cientes de seu diagnóstico. Os principais temas emergentes incluíram dinâmica familiar, conexão com o ambiente escolar, desafios na adesão ao tratamento, idade no momento da revelação do diagnóstico e tempo decorrido desde então. A análise das narrativas desses jovens, permitiu explorar aspectos individuais e sociais da experiência, revelando similaridades e diferenças entre eles. As oficinas de dança circular ofereceram um espaço lúdico para a expressão de emoções e sentimentos por meio dos movimentos corporais, ampliando as perspectivas dos jovens em relação ao futuro.

Abstract This study analyzes the life stories of eight young people living with vertically transmitted HIV in order to understand their perceptions marked by secrecy and silence regarding their experiences with the virus. Conducted at a specialized outpatient clinic in Rio de Janeiro, the study adopted circle dance, a Complementary and Integrative Health Practice, as a care tool. Using a qualitative approach and Life History as a data collection method, the focus was to understand the youth's experiences related to the disease and the crucial aspects of their lives. Three girls and five boys participated in the study, all aware of their diagnosis. The principal emerging themes included family dynamics, school environment connection, challenges in treatment adherence, age at the time of diagnosis disclosure, and time elapsed since then. Analyzing these young people's narratives allowed us to explore individual and social aspects of their experiences, revealing their similarities and differences. The circle dance workshops provided a playful space for expressing emotions and feelings through body movements, expanding young people's perspectives on the future.

Taylor's power law for freshwater fishes: Functional traits beyond statistical inevitability.

Taylor's power law (TPL) describes the expected range of parameters of the mean-variance scaling relationship and has been extensively used in studies examining temporal variations in abundance. Few studies though have focused on biological and ecological covariates of TPL, while its statistical inherences have been extensively debated. In the present study, we focused on species-specific features (i.e. functional traits) that could be influential to temporal TPL. We combined field surveys of 180 fish species from 972 sites varying from small streams to large rivers with data on 31 ecological traits describing species-specific characteristics related to three main niche dimensions (trophic ecology, life history, and habitat use). For each species, the parameters of temporal TPL (intercept and slope) were estimated from the log-log mean-variance relationships while controlling for spatial dependencies and biological covariates (species richness and evenness). Then, we investigated whether functional traits explained variations in TPL parameters. Differences in TPL parameters among species were explained mostly by life history and environmental determinants, especially TPL slope. Life history was the main determinant of differences in TPL parameters and thereby aggregation patterns, with traits related to body size being the most influential, thus showing a high contrast between small-sized species with short lifespans and large-bodied migratory fishes, even after controlling for phylogenetic resemblances. We found that life history traits, especially those related to body size, mostly affect TPL and, as such, can be determinants of temporal variability of fish populations. We also found that statistical effects and phylogenetic resemblances are embedded in mean-variance relationships for fish, and that environmental drivers can interact with ecological characteristics of species in determining temporal fluctuations in abundance.

Influence of environmental patterns on the population structure and secondary production of the fiddler crab Uca maracoani (Latreille) in the Amazon mangroves.

Uca maracoani is a fiddler crab found in estuaries along the western Atlantic coast, with a notable preference for euhaline environments. This study aimed to analyze the population structure and dynamics of this species in an estuary on the North Coast of Brazil, specifically in an area of the upper estuary where seasonal rainfall fluctuations result in significant changes in salinity. Monthly crab samples were taken from December 2013 to November 2015, together with measurements of environmental variables, such as water and climate parameters. The population maintains a balanced sex ratio; however, males are generally larger, with lower mortality rates and longer lifespans than females. Reproduction is continuous but mainly takes place in the dry season when salinity levels are higher (above 12‰). Higher crab densities have been observed during the rainy season when, despite lower salinity levels (below 10‰), the conditions for survival (food availability and milder climate) seem to be more favorable. The estimated average annual biomass and production for the population were 2.62 g AFDM m-2 and 5.43 g AFDM m-2 year-1, respectively, characterized by a high turnover rate (P/B = 2.10 year-1). Our results suggest that U. maracoani has thriving populations in the Amazon coast's mangroves, benefiting from the vast muddy intertidal zone and the high organic content delivered by the estuaries.

Tree demographic strategies largely overlap across succession in Neotropical wet and dry forest communities.

Secondary tropical forests play an increasingly important role in carbon budgets and biodiversity conservation. Understanding successional trajectories is therefore imperative for guiding forest restoration and climate change mitigation efforts. Forest succession is driven by the demographic strategies-combinations of growth, mortality and recruitment rates-of the tree species in the community. However, our understanding of demographic diversity in tropical tree species stems almost exclusively from old-growth forests. Here, we assembled demographic information from repeated forest inventories along chronosequences in two wet (Costa Rica, Panama) and two dry (Mexico) Neotropical forests to assess whether the ranges of demographic strategies present in a community shift across succession. We calculated demographic rates for >500 tree species while controlling for canopy status to compare demographic diversity (i.e., the ranges of demographic strategies) in early successional (0-30 years), late successional (30-120 years) and old-growth forests using two-dimensional hypervolumes of pairs of demographic rates. Ranges of demographic strategies largely overlapped across successional stages, and early successional stages already covered the full spectrum of demographic strategies found in old-growth forests. An exception was a group of species characterized by exceptionally high mortality rates that was confined to early successional stages in the two wet forests. The range of demographic strategies did not expand with succession. Our results suggest that studies of long-term forest monitoring plots in old-growth forests, from which most of our current understanding of demographic strategies of tropical tree species is derived, are surprisingly representative of demographic diversity in general, but do not replace the need for further studies in secondary forests.

Size structure, age, and growth of the blue shark, Prionace glauca (Linnaeus, 1758) in southern Brazil.

The blue shark is a highly migratory species with a worldwide distribution, making it susceptible to multiple fishing fleets across the globe. In southern Brazil, it is an important target, comprising up to 40% of the total biomass landed by the commercial surface longline fleet. This study aims to contribute to a better understanding of how the species uses the region and to update its life-history information available for future assessments. Over five consecutive years (2018-2022) of landings and onboard monitoring, we gathered size data and vertebral samples to describe the species size composition in the region, as well as its seasonal and interannual variability and to update estimated life-history parameters. The results showed that southern Brazil is mainly inhabited by large juvenile males that arrive during winter (July-September) and stay until spring (October-December), when their frequency decreases. Small adult males are present throughout the year but in higher frequencies during summer. A small number of adult females are present with higher frequencies during spring and summer, which decreases during the austral autumn and winter. Some variability in the presence of each life stage was observed among years. The estimated life-history parameters were as follows: L∞: 255.02 cm fork length (FL), k: 0.20, L0:35.68 cm FL for males; L∞: 246.47 cm FL, k: 0.23, L0:36.77 cm FL for females; and L∞: 269.58 cm FL, k: 0.18, L0:36.19 cm FL for pooled sexes. However, the estimated values must be cautiously interpreted, as the obtained samples cannot be construed as representative of the entire harvested stock due to the lack of consistent presence of some life stages in the study region.

Corrigendum: Geographical and life-history traits associated with low and high species richness across angiosperm families.

[This corrects the article DOI: 10.3389/fpls.2023.1276727.].

Growing or reproducing? Assessing the existence of a trade-off in the globose cactus Gymnocalycium monvillei.

Resource allocation in plants is a fundamental aspect of life history theory. In Cactaceae, the specific trade-off between sexual reproduction and vegetative growth has still not been studied. The aim of this work was to assess if there is a trade-off between growth and reproduction, and to analyse whether both growth and allocation to reproduction depend on size of the individual. In this study, we used Gymnocalycium monvillei, a globose cactus endemic to the mountains of central Argentina, as a model species. Specifically, we analysed the relationship of growth (percentage increase in diameter) and size of individuals (diameter) to seed production, seed mass, germination, and mean germination time. To relativize the effect of size on seed production, two variables were calculated: the ratio of seed production to plant size (RSPS), and the ratio of total seed mass to plant size (RSMS). We found that both seed production and total seed mass were significantly related to cactus size. However, growth was not related to seed mass or to seed production, even when they were relativized. Germination and mean germination time were not related to plant size or growth. In the studied species, a slow-growing globose cactus, we did not find a trade-off between growth and reproduction.

Early ontogeny of the freshwater fish Rhytiodus microlepis (Characiformes, Anostomidae) from the Amazon basin.

The early development of the freshwater fish Rhytiodus microlepis is characterized by the description of external morphological, meristic, and morphometric changes, as well as the growth patterns, thereby establishing a reference for the identification of its larvae and juveniles. Specimens were collected from the Amazon river channel and floodplain. Ninety-seven individuals were analysed with standard length varying between 4.31 and 79.23 mm. Rhytiodus microlepis larvae are altricial, with an elongated and fusiform body, anal opening reaching the middle region of the body, and simple nostrils becoming double and tubular during development. The pigments vary from one to two chromatophores in the dorsal region of the head in pre-flexion and flexion, but later the pigmentation pattern intensifies, transverse bands appear along the body, and a conspicuous spot appears in the basal region of the caudal fin. The total number of myomeres ranges from 49 to 50. During the transition from larval (post-flexion) to the juvenile periods, the most significant anatomical changes occur, such as the presence of all fins and increased body pigmentation. Integrated myomere count and pigmentation pattern are effective for the correct identification of the initial life stages of R. microlepis from the Amazon basin. Our results expand the knowledge about the early life history of Neotropical freshwater fish species.

A review of age estimation methods in non-avian reptiles by growth marks in hard tissues.

Age and growth-related data are basic biological parameters, essential in population ecology, evolution, and conservation biology. There is a growing body of published information on reptile demography derived from sclerochronology, a technique based on counting the growth layers deposited in bones (skeletochronology) and other hard body structures. Since the data are not always easily available, we compiled the existing published data, described the current status of knowledge, synthetized the conclusions of disparate studies, and identified patterns of research and information gaps, prioritizing the needs for future research. Our database includes the results of 468 published studies covering 236 reptile species from 41 families. These represent less than 2% of the total number of known extant species. Turtles and crocodiles are proportionally better studied, while snakes are the least examined group. The distribution of the research does not reflect conservation needs; we found an important geographic bias, with an overrepresentation of Northern temperate species. Only 23% of the studies checked the assumption of periodicity of growth marks deposition, and the method was found to be reliable or adequate in 79% of the cases. Overall, the data obtained through sclerochronology can be considered robust, especially if validation methods are employed, since the general goal is to characterize population parameters, trends, and dynamics, rather than determining the exact age of any specimen in particular.

Parasitism in viviparous vertebrates: an overview.

The reproductive mode of viviparity has independently evolved in various animal taxa. It refers to the condition in which the embryos or young develop inside the female's body during gestation, providing advantages such as protection, nutrition, and improved survival chances. However, parasites and diseases can be an evolutionary force that limit the host's resources, leading to physiological, morphological, and behavioral changes that impose additional costs on both the pregnant female and her offspring. This review integrates the primary literature published between 1980 and 2021 on the parasitism of viviparous hosts. We describe aspects such as reproductive investment in females, offspring sex ratios, lactation investment in mammals, alterations in birth intervals, current reproductive investment, variations between environments, immune system activity in response to immunological challenges, and other factors that can influence the interaction between viviparous females and parasites. Maintaining pregnancy incurs costs in managing the mother's resources and regulating the immune system's responses to the offspring, while simultaneously maintaining an adequate defense against parasites and pathogens. Parasites can significantly influence this reproductive mode: parasitized females adjust their investment in survival and reproduction based on their life history, environmental factors, and the diversity of encountered parasites.

Geographical and life-history traits associated with low and high species richness across angiosperm families.

Introduction: The phenomenal expansion of angiosperms has prompted many investigations into the factors driving their diversification, but there remain significant gaps in our understanding of flowering plant species diversity. Methods: Using the crown age of families from five studies, we used a maximum likelihood approach to classify families as having poor, predicted or high species richness (SR) using strict consensus criteria. Using these categories, we looked for associations between family SR and i) the presence of an inferred familial ancestral polyploidization event, ii) 23 life history and floral traits compiled from previously published datasets and papers, and iii) sexual system (dioecy) or genetically determined self-incompatibility (SI) mating system using an updated version of our own database and iv) geographic distribution using a new database describing the global distribution of plant species/families across realms and biomes and inferred range. Results: We find that more than a third of angiosperm families (65%) had predicted SR, a large proportion (30.2%) were species poor, while few (4.8%) had high SR. Families with poor SR were less likely to have undergone an ancestral polyploidization event, exhibited deficits in diverse traits, and were more likely to have unknown breeding systems and to be found in only one or few biomes and realms, especially the Afrotropics or Australasia. On the other hand, families with high SR were more likely to have animal mediated pollination or dispersal, are enriched for epiphytes and taxa with an annual life history, and were more likely to harbour sporophytic SI systems. Mapping the global distribution of georeferenced taxa by their family DR, we find evidence of regions dominated by taxa from lineages with high vs low SR. Discussion: These results are discussed within the context of the literature describing "depauperons" and the factors contributing to low and high biodiversity in angiosperm clades.

História de vida de executivos e resiliência no trabalho: interfaces e relações / Executive life history and workplace resilience: interfaces and relationships

A Resiliência é um processo psicológico que envolve a adaptação positiva diante das adversidades, proporcionando aos indivíduos oportunidades de crescimento e aprendizado. O presente estudo buscou compreender as possíveis relações entre a história de vida de executivos e os comportamentos resilientes demonstrados no ambiente de trabalho. Este estudo é uma pesquisa qualitativa que contou com a participação de executivos de quatro organizações do setor têxtil sediadas no estado de Santa Catarina, Brasil. A coleta de dados foi realizada a partir do método biográfico e de entrevistas semiestruturadas. A análise de conteúdo revelou que a resiliência é um processo aprendido ao longo da vida, o qual auxiliou os participantes a enfrentar e superar as adversidades presentes nos contextos de trabalho em tempos difíceis. Os resultados demonstraram que a resiliência dos executivos teve impacto no alcance dos resultados organizacionais, no desenvolvimento de novas habilidades e na manutenção de sua saúde, bem-estar e qualidade de vida. A resiliência é uma capacidade que pode auxiliar no enfrentamento e superação das adversidades no ambiente de trabalho, especialmente em momentos desafiadores.

Resilience is a psychological process that involves positive adaptation in the face of encoureted adversities, offering individuals opportunities for growth and learning. This study aimed to explore the potential relationships between executives' life histories and the resilient behaviors they exhibit in the workplace. It is a qualitative research conducted with executives from four organizations in the textile sector, based in the state of Santa Catarina, Brazil. Data was collected using biographical methods and semi-structured interviews. Content analysis revealed that resilience is a learned proces that unfolds throughout life, assisting participants in confronting and surmounting the challenges present in work environments during challenging times. The results demonstrated that executives had a significant impact on achieving organizational outcomes, developing new skills, and maintaining their health, well-being, and quality of life. Resilience is a valuable capacity that can aid in facing and surpassing workplace adversities, especially in moments of difficulty.

Hemoparasites Do Not Affect Life-History Traits and Cellular Immune Response in Treefrog Hosts Boana cordobae.

We provide the first evidence for hemoparasites in the endemic Cordoba treefrog Boana cordobae. We collected 37 adult frogs at 1200 m a.s.l. in the Comechingones Mountains in the Córdoba province (Argentina). Each individual was sexed, then snout-vent length and body mass were recorded, a toe was collected for skeletochronological age determination, and a slide with a blood smear was prepared for hemoparasite screening, before releasing the frogs in situ. A total of 81% (n = 30) of the frogs were infected by hemogregarines and trypanosomes with a high intensity of infections. Dactylosoma was found for the first time in Argentina. Hemoparasites had no significant effect on the leukocyte profile, which we assessed from the May-Grünwald-Giemsa-stained blood smears. The neutrophils/lymphocytes ratio, indicative of stress, was insignificantly higher (0.06) in parasitized frogs than in parasite-free individuals (0.04). Infected frogs were larger than the controls, but this effect vanished when correcting size data for age. Young frogs (first-breeders) dominated the age distribution of parasite-free individuals, suggesting that infection of frogs takes usually place after sexual maturation. Vectors transmitting hemoparasites to B. cordobae remain to be identified. We demonstrate that moderate to high intensities of hemoparasites do not significantly affect the cellular immune response of B. cordobae, or any of the life-history traits studied, nor did they show any external sign of disease.

Long-term female bias in sex ratios across life stages of Harpy Eagle, a large raptor exhibiting reverse sexual size dimorphism.

The primary (PSR), secondary (SSR) and adult (ASR) sex ratios of sexually reproducing organisms influence their life histories. Species exhibiting reversed sexual size dimorphism (RSD) may imply a higher cost of female production or lower female survival, thus generating biases in PSR, SSR and/or ASR towards males. The Harpy Eagle is the world's largest eagle exhibiting RSD. This species is found in the Neotropical region and is currently threatened with extinction. We used molecular markers to determine the sex of 309 Harpy Eagles spanning different life stages-eaglets, subadults and adults-from 1904 to 2021 within the Amazon Rainforest and Atlantic Forest. Sex ratios for all life stages revealed a female-biased deviation across all periods and regions. Our results suggest that the population bias towards females is an evolutionary ecological pattern of this species, and SSR and ASR likely emerged from the PSR. This natural bias towards females may be compensated by an earlier sexual maturation age of males, implying a longer reproductive lifespan and a higher proportion of sexually active males. A better understanding of the Harpy Eagle's life history can contribute to understanding sex-role evolution and enable more appropriate conservation strategies for the species.

Review of the diet of Icterus pustulatus (Passeriformes: Icteridae) and a new prey, Oiketicus sp. (Lepidoptera: Psychidae) from Mexico

We report a case of predation on the basket worm Oiketicus sp. (Lepidoptera, Psychidae) by the Streak-backed Oriole (Icterus pustulatus) in the Municipality of Santa Cruz Xoxocotlán, Oaxaca, Mexico. The bird was photographed, and we describe the prey based on its basket, cephalic capsule, and fragments of thoracic segments. We describe the foraging strategy and provide a list of previously recorded food resources in the diet of I. pustulatus. This is the first documentation of a basket worm being consumed by I. pustulatus, which may be considered omnivorous.

Reportamos un caso de depredación sobre el gusano canasta Oiketicus sp. (Lepidoptera, Psychidae) por la calandria dorso rayado (Icterus pustulatus) en el Municipio de Santa Cruz Xoxocotlán, Oaxaca, México. El ave fue fotografiada y describimos la presa a partir de su canasta, cápsula cefálica y fragmentos de segmentos torácicos. Describimos la estrategia de forrajeo y presentamos una lista de recursos alimentarios previamente registrados en la dieta de I. pustulatus. Esta es la primera documentación de alimentación de un gusano canasta por parte de I. pustulatus, el cual puede ser considerada omnivora.

Influence of phylogenetic diversity of plant communities on tri-trophic interactions.

Phylogenetic diversity of plant communities can influence the interaction between plants, herbivores, and their natural enemies. Plant communities with phylogenetically distant species tend to present a wide variety of functional traits and ecological niches, which in turn can influence competitive interactions among plants as well as food and habitat quality for herbivores and their natural enemies. To assess some different mechanisms by which phylogenetic diversity of plant communities can influence herbivores and their natural enemies, we established 12 experimental plots of tropical trees with two treatments: high and low phylogenetic diversity. We measured plant growth and anti-herbivore defenses, herbivore foliar damage, and predator activity in seven species that were present in both treatments. We found significant differences in the expression of plant traits as a function of species identity and their life history, but also depending on the phylogenetic context in which they grew. Pioneer species had higher growth and produced more phenolics in plots with high phylogenetic diversity versus plants in plots with low phylogenetic diversity. Accordingly, herbivore damage in these species was greater in plots with low phylogenetic diversity. Finally, predator activity on caterpillar clay models placed on plants was greater within the low phylogenetic diversity treatment, but only for non-myrmecophytic species. These results suggest that plant phylogenetic diversity can influence the expression of growth and defensive traits and further modify the interaction between plants, herbivores, and their natural enemies. However, such effects depend on plant life history and the presence of mutualistic interaction with ants.

Hans Hugo Bruno Selye y el estrés, hito en la historia de la Medicina moderna / Hans Hugo Bruno Selye and the stress, a milestone in the modern medical history

Fundamento: Hans Hugo Bruno Selye, fisiólogo y médico austrohúngaro nació el 26 de enero de 1907, posteriormente se naturalizó canadiense, este hombre que vivió 75 años y llegó a ser director del Instituto de Medicina y Cirugía Experimental de la Universidad de Montreal, Canadá, hasta su retiro en 1970. Falleció en 1982, en esa misma ciudad. Objetivo: Describir la vida y obra del ilustre académico Hans Hugo Bruno Selye y la historia del estrés como hito en la historia de la Medicina moderna. Metodología: Se realizó un estudio retrospectivo de corte histórico donde se utilizaron métodos teóricos como el análisis documental y el histórico-lógico. Desarrollo: El doctor empezó a desarrollar su famosa teoría acerca de la influencia del estrés en la capacidad de las personas para enfrenarse o amoldarse a las consecuencias de lesiones o enfermedades en el segundo año de sus estudios de Medicina (1926). Esta investigación le permitió descubrir que los pacientes con variedad de dolencias manifestaban síntomas similares, los cuales podían ser atribuidos a los esfuerzos del organismo para responder a esta condición de estar enfermo. Él llamó a este conjunto de síntomas síndrome del estrés o síndrome de adaptación general (GAS). Conclusiones: Este médico es una de las personalidades más importantes de la historia de la Medicina; su teoría del estrés proporcionó un marco conceptual transcendental para cuestiones posteriores de los mecanismos y manifestaciones de las reacciones del mismo.

Background: Hans Hugo Bruno Selye, Austro-Hungarian physiologist and physician, born January 26, 1907, later naturalized Canadian citizen, this man who lived 75 years and became the Director of Experimental Medicine and Surgery Institute of Montreal University in Canada, until his retirement in 1970. He passed away in 1982, in the same city. Objective: Describe the life and achievements of the distinguished academic Hans Hugo Bruno Selye and the history of stress as a milestone in modern medical history. Methodology: A historical retrospective study was conducted using theoretical methods such as documental and historical-logical analysis. Methodology: The doctor began to build his famous theory about the influence of stress on the ability of persons to cope or adjust to the injury or illness consequences in the second year of his medical studies (1926). He discovered with this investigation that patients with a variety of ailments exhibited similar symptoms, which could be attributed to the organism efforts to respond to the condition of being sick. He named this set of symptoms stress syndrome or general adaptation syndrome (GAS). Conclusions: This physician is one of the greatest personalities in medical history; his stress theory provided a transcendental conceptual framework for later issues of the mechanisms and manifestations for stress reactions.

Similar regional-scale survival of tropical and southern temperate birds from the New World.

The general assumption that the survival patterns of tropical and southern temperate birds are similar lacks empirical data from higher latitudes. Regional comparisons of New World species are rare, and this assumption has been based on data from African studies. Here, we estimate the survival rates of 88 tropical and southern temperate bird populations (69 species) from eight localities in South America to evaluate the hypothesis that the survival of these populations is homogeneous at the regional scale. We estimated survival based on the Cormack-Jolly-Seber model and compared values from different environments. The survival estimates ranged from 0.30 to 0.80 (0.56 ± 0.12). Apparent survival did not differ significantly between low-latitude tropical environments (03°S) and the other sites from high-latitudes (between 22° and 34°S). Despite a predicted positive trend, body size was not significantly related to survival among passerines. On the other hand, phylogenetic relationships explained more than a third of the variation in bird survival. Based on the largest available database on South American bird species, our findings support the hypothesis that bird survival is homogeneous, at the regional scale, along the southern hemisphere. In particular, we reinforce the hypothesis that climatic variation has a limited influence on bird survival in the southern hemisphere.

Do habitat fragmentation and degradation influence the strength of fine-scale spatial genetic structure in plants? A global meta-analysis.

As primarily sessile organisms, plants often show a non-random spatial distribution of genotypes over distance. This process known as fine-scale spatial genetic structure (FSGS) has been suggested through systematic reviews to depend on life form, mating system, and pollen and seed dispersal vectors, while there is no consensus on its behaviour due to external factors, such as anthropogenic habitat changes. By conducting a systematic review and global meta-analysis of empirical FSGS studies, we aimed to evaluate how anthropogenic habitat fragmentation and degradation influence the strength of FSGS in plant populations by means of the Sp statistic. Moreover, we tested how pollination and seed dispersal vectors contribute to the variation of the Sp statistic. We retrieved 243 FSGS studies from 1960 to 2020 of which only 65 were informative for the systematic review. Most empirical studies comprised outcrossers (84%) and trees (67%), with few herbs (23%) and scarce annual species (2%). In weighted meta-analyses for 116 plant populations (31 studies), we did not detect significant effects in the magnitude of effect sizes for the Sp statistic among undisturbed, degraded and fragmented habitats. Results showed significant effects for seed dispersal vectors, but not for pollination. Overall, we observed high variation among the effect sizes (not related to the goodness-of-fit of mixed models) of habitat status, pollination and seed dispersal categories, which precludes identifying biological trends on the Sp statistic. More empirical studies are needed that contrast multiple plant populations in disturbed versus undisturbed habitats, and by increasing the taxonomic groups, such as herbs and annual plants.

The Assembly of Bacteria Living in Natural Environments Shapes Neuronal Integrity and Behavioral Outputs in Caenorhabditis elegans.

Bacterivore nematodes are the most abundant animals in the biosphere, largely contributing to global biogeochemistry. Thus, the effects of environmental microbes on the nematodes' life-history traits are likely to contribute to the general health of the biosphere. Caenorhabditis elegans is an excellent model to study the behavioral and physiological outputs of microbial diets. However, the effects of complex natural bacterial assemblies have only recently been reported, as most studies have been carried out with monoxenic cultures of laboratory-reared bacteria. Here, we quantified the physiological, phenotypic, and behavioral traits of C. elegans feeding on two bacteria that were coisolated with wild nematodes from a soil sample. These bacteria were identified as a putative novel species of Stenotrophomonas named Stenotrophomonas sp. strain Iso1 and a strain of Bacillus pumilus designated Iso2. The distinctive behaviors and developmental patterns observed in animals fed with individual isolates changed when bacteria were mixed. We studied in more depth the degeneration rate of the touch circuit of C. elegans and show that B. pumilus alone is protective, while the mix with Stenotrophomonas sp. is degenerative. The analysis of the metabolite contents of each isolate and their combination identified NAD+ as being potentially neuroprotective. In vivo supplementation shows that NAD+ restores neuroprotection to the mixes and also to individual nonprotective bacteria. Our results highlight the distinctive physiological effects of bacteria resembling native diets in a multicomponent scenario rather than using single isolates on nematodes. IMPORTANCE Do behavioral choices depend on animals' microbiota? To answer this question, we studied how different bacterial assemblies impact the life-history traits of the bacterivore nematode C. elegans using isolated bacteria found in association with wild nematodes in Chilean soil. We identified the first isolate, Iso1, as a novel species of Stenotrophomonas and isolate Iso2 as Bacillus pumilus. We find that worm traits such as food choice, pharyngeal pumping, and neuroprotection, among others, are dependent on the biota composition. For example, the neurodegeneration of the touch circuit needed to sense and escape from predators in the wild decreases when nematodes are fed on B. pumilus, while its coculture with Stenotrophomonas sp. eliminates neuroprotection. Using metabolomics analysis, we identify metabolites such as NAD+, present in B. pumilus yet lost in the mix, as being neuroprotective and validated their protective effects using in vivo experiments.