Effects of disturbance on population biology of the rosette species Eryngium horridum Malme in grasslands in southern Brazil

Aging is not a matter of choice; it is our fate. The “time-dependent functional decline that affects most living organisms” is coupled with several alterations in cellular processes, such as cell senescence, epigenetic alterations, genomic instability, stem cell exhaustion, among others. Age-related morphological changes in dental follicles have been investigated for decades, mainly motivated by the fact that cysts and tumors may arise in association with unerupted and/or impacted teeth. The more we understand the physiology of dental follicles, the more we are able to contextualize biological events that can be associated with the occurrence of odontogenic lesions, whose incidence increases with age. Thus, our objective was to assess age-related changes in metabolic pathways of dental follicles associated with unerupted/impacted mandibular third molars from young and adult individuals. For this purpose, a convenience sample of formalin-fixed paraffin-embedded (FFPE) dental follicles from young (<16 y.o., n = 13) and adult (>26 y.o., n = 7) individuals was selected. Samples were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS)-based untargeted metabolomics. Multivariate and univariate analyses were conducted, and the prediction of altered pathways was performed by mummichog and Gene Set Enrichment Analysis (GSEA) approaches. Dental follicles from young and older individuals showed differences in pathways related to C21-steroid hormone biosynthesis, bile acid biosynthesis, galactose metabolism, androgen and estrogen biosynthesis, starch and sucrose metabolism, and lipoate metabolism. We conclude that metabolic pathways differences related to aging were observed between dental follicles from young and adult individuals. Our findings support that similar to other human tissues, dental follicles associated with unerupted tooth show alterations at a metabolic level with aging, which can pave the way for further studies on oral pathology, oral biology, and physiology.

Comparative leaf ecophysiology and anatomy of seedlings, young and adult individuals of the epiphytic aroid Anthurium scandens (Aubl.) Engl.

Paroxetine has been associated with increased rates of suicidality in adolescents treated in antidepressant clinical trials. Regulatory agencies in the United States and the UK have issued warnings that are already changing clinical practice for adolescents. In a pilot analysis, we characterized the extent of risk by investigating paroxetine-associated suicidality in a related high-risk population, younger and adult individuals with bipolar disorder whose rate of suicide attempts approaches 2% per year. A cross-sectional survey and cohort analysis of 1,000 patients followed for at least 1 year under naturalistic conditions in the NIMH-funded STEP-BD network revealed no association of paroxetine with suicidality in those less than or at least 21 years of age. In fact, the younger group showed a trend for decreased suicidality (P = .13). Thus, increased suicidality risk with paroxetine exposure does not extend to this other high-risk mood-disordered population, even among younger individuals. Psychopharmacology Bulletin. 2006;39(1):31-37.

Population genetic structure results from the interaction between historical events, current ecological conditions and life traits. The genetic structure and gene flow between populations are important to species dynamics, mainly for rare and endangered species that are more vulnerable to landscape changes and fragmentation. Here we evaluated the genetic diversity, population structure and gene exchange in Petunia bonjardinensis, P. reitzii and P. saxicola, three rare species endemic to subtropical highland grasslands in southern South America. We analysed the genetic diversity and structure considering historical events, such as founder effect and climate changes, and biological traits of each species. We also estimated the conservation status for these three species. We collected samples from all adult individuals and occurrence sites that could be found at the same flowering season and genotyped them for 13 nuclear microsatellite markers. Our results indicate that rarity is probably historical for these species, given that we found no genetic evidence for recent bottlenecks. Petunia bonjardinensis, with the largest occurrence area and population sizes, displayed the higher diversity indices. The other two showed lower genetic diversity and are geographically most restricted. Gene exchange among these species was low, although they share some ancestral genetic polymorphism. Historical migration, founder effects and Pleistocene climate cycles ae the main factors explaining genetic diversity, and this was also influenced by reproductive biology and recent habitat loss, whereas the landscape influences the structure. Based on IUCN criteria, the three species are endangered, and the main risk for their survival is probably anthropic activity in the occurrence area. We recommend an urgent programme for the preservation of these species in situ and ex situ.

Aim: Studies have shown that the prevalence of the periodontal disease among young people is relatively low; however, periodontitis is a public health problem and prevalence among adults has been increasing. This study aimed to assess the prevalence of periodontitis among young adults and adults in Colombia and to propose an alternative approach for early detection of periodontitis. Objectives: To present an alternative approach for the prevention of periodontitis, two different classifications were used to estimate disease prevalence. In addition, periodontitis severity was associated with sociodemographic and clinical risk factors in a logistic regression model. Material and methods: Selected data from 9150 subjects evaluated in the IV National Oral Health Survey (ENSAB IV) from Colombia were used. The ages ranged from 18 to 79 years old. Statistical analysis: Data were subjected to two different disease definition criteria and were evaluated by bivariate and multivariate analysis using a p-value of 5%. Results: The alternative classification approach elucidated an increase in the prevalence of periodontitis in young individuals (26.1%). According to the previous classification, 20.1% of young individuals and 94.3% of adults had mild to moderate periodontitis. The prevalence of moderate and severe cases was similar. Multivariate analysis of the variables age, gender, enrolment in the subsidized socioeconomic program and health care system, and tooth loss were associated with moderate and severe periodontitis (p&lt;0.05). Conclusions: The early identification of mild cases in young individuals may help to identify potentially vulnerable groups. Early diagnosis of periodontitis and timely intervention in individuals with gingivitis, especially for those presenting risk factors, should be reinforced as an alternative approach to prevent disease progression and reduce the prevalence of adults with periodontitis in the future.

The role of facilitation in the structuring of plant communities has been often demonstrated in environments under high abiotic stress, especially in semi‐arid and arid ecosystems and high elevations. Few studies, however, analysed facilitation in systems that are highly productive and rich in species, which are thought to be theoretically unlikely to demonstrate strong effects of facilitation. Here, we investigate the importance of Eryngium horridum, a rosette species, on the maintenance of plant diversity in subtropical grasslands in southern Brazil. We evaluated facilitation in areas under two different types of management: abandonment and grazing. Plots were established in areas with and without individuals of E. horridum and all species were identified and had their cover estimated. The Relative Neighbour Effect index was calculated in order to verify the presence of competition or facilitation. Our results indicated facilitation in both abandoned and in grazed grasslands, but apparently through different mechanisms. In the first case, the plant's architecture opens the canopy and allows more light to reach small forbs in the grass matrix. In the second case, E. horridum appears to protect more palatable species from herbivores. Otherwise considered an obnoxious species, E. horridum plays an important ecological role in subtropical grasslands in southern Brazil by facilitating other species and consequently, increasing local richness. Areas with this rosette species are important sources of diaspores, which are able to colonize new open sites and thus, maintain biodiversity.

The natural grasslands are the main forage of Rio Grande do Sul in the Summer. But, it can provide small average daily gain, acting on the raise system, retarding the heifer’s mat and proportion rise of age the bullock’s killing. The tropical grasslands are the tool that may be utilized by creators to raise the efficiency of the raise cattle system. However, in the heifers couple, the tropical forage can’t be enough to provide desirables body conditions to affirm the couple’s success. Then, the use of supplementation may be another useful tool. Although, the objective of this paper is describe the most important results of the use of tropical grasslands in southern Brazil, and discuss strategies of management to the maximum utilization of these forages.

Effects of defoliation frequencies on above- and belowground biodiversity and ecosystem processes in subtropical grasslands of southern Brazil

Soil physical properties in a natural highland grassland in southern Brazil subjected to a range of grazing heights

The purpose of the work is to predict the appearance of significant vertical movements of two age zooplankton groups as a result of adaptation to habitat conditions. The methodological basis for solving the problem is the maximization of the fitness function. Vertical migrations are considered as a strategy that ensures the achievement of the greatest value of this function for given environmental conditions. The environmental factors influencing the appearance of vertical migrations are the availability of food and predator activity, water temperature and hydrogen sulfide concentration. Experimentally recorded data on these factors have always some noise and are of a discrete selective nature. In this regard, machine learning tools are used to solve the problem. The most important stage of the work is the construction of the training sample. For this purpose, the results of an analytical and numerical search for the optimal behavior are used with linear-quadratic and hyperbolic approximations of external factors.As a result of the study, a neural network was built that solves the problem of classifying input data sets into four classes corresponding to the presence or absence of significant vertical movements in young and adult individuals under these conditions. This makes it possible to fairly accurately recognize the presence or absence of significant vertical migrations for young and adult zooplankton individuals according to approximately specified environmental factors.KeywordsFitness functionNeural networksPattern recognitionZooplankton diel vertical migration

Trichilia elegans A. Juss. is a widely distributed species that occurs from Venezuela to Uruguay and constitutes a common component of seasonal forests. Even though the studies on the Pantanal flora started last century, researches on the structure and spatial distribution of tree species are still rare. This work aimed at identifying the pattern of spatial distribution and the diametric distribution of T. elegans and verifying whether there is a correlation between the number of young individuals and the number of adult individuals in a semi-deciduous forest of the Pantanal da Nhecolândia. We sampled 50 plots of 200 m2 each and registered the young and adult individuals in each one of them. To identify the pattern of spatial distribution, we used the Morisita Index (MI) and the variance/mean ratio (R). The linear correlation coefficient was used to verify whether there is a correlation between populations of the juveniles and adults. We found 218 young and 78 adult individuals. Young and adult individuals presented gregarious spatial distribution, and the young ones (MI = 2.32; R = 5.49) were more gregarious than the adults (MI = 1.88; R = 2.05). The linear correlation coefficient found (r = 0.60) demonstrated that the density of young individuals is highly correlated with the density of adult individuals.

Grasslands in southeastern South America have been extensively converted to various land uses such as agriculture, threatening regional biodiversity. Active restoration has been viewed as a management alternative for recovery of degraded areas worldwide, although most studies are conducted in forests and none has evaluated the effect of active restoration of grasslands in southeastern South America. From 2015 through 2017 we monitored a federally owned tract of grassland from the beginning of the active‐restoration process. We compared the bird community in this active‐restoration area (AR) with a reference area (NG) in Pampa grasslands in southern Brazil. We sampled birds by point counts and surveyed vegetation structure in plots. Over the 3 years of active restoration, bird species richness and abundance were higher in AR (30 species, 171 individuals) than NG (22 species, 154 individuals). The species composition also differed between the two habitats. Grassland bird species were present in both AR and NG. The vegetation structure differed between AR and NG in five attributes: height, short and tall grasses, herbs, and shrubs. Since it has been found that active restoration is useful in promoting species diversity, we encourage studies of the use of long‐term restoration efforts. Our study, even on a local scale, showed a rapid recovery of the bird community in the active‐restoration compared to native grassland, and suggests the potential for recovery of the degraded grasslands of the Brazilian Pampa biome.

Using a quantitative in vitro autoradiographic approach, vasoactive intestinal polypeptide (VIP) binding site densities were compared in the post-mortem hypothalamus of human neonate/infant and adult. The densities were similar during development in most of the hypothalamic nuclei and areas examined underlying the stability of 125I-VIP binding sites in the post-mortem hypothalamus of young and adult individuals. However, the ventral part of the medial preoptic area, the medial, lateral, and supramammillary nuclei were characterized by an increase of 125I-VIP binding with age. In young and adult individuals, the highest densities of hypothalamic 125I-VIP binding sites were detected in the supraoptic and infundibular nuclei; the ependyma; the organum vasculosum of the lamina terminalis; the horizontal limb of the diagonal band of Broca; the ventral part of the medial preoptic area (in adult); the suprachiasmatic, paraventricular, and periventricular nuclei; and the medial and lateral mammillary nuclei in adult. Moderate densities were found in the vertical limb of the diagonal band of Broca, the bed nucleus of the stria terminalis, the ventral part of the medial preoptic area in neonate/infant, the medial and lateral mammillary nuclei in neonate/infant, the supramammillary nucleus in adult, the dorsal hypothalamic area, and the ventromedial nucleus. Low to moderate binding site densities were observed in the other hypothalamic regions of young or adult individuals. The nonspecific binding ranged from 15% of the total binding in the anterior hypothalamus to 20% in the mediobasal and posterior hypothalamic levels. Taken together, these results provide evidence for a large distribution of VIP binding sites in neonate/infant and adult human hypothalamus suggesting the implication of VIP in the development of this brain structure and the maintenance of its various functions.

The semi-arid region of Brazil has historically been characterised by water scarcity, which for centuries has influenced the dynamics of the environment and the way of life of human populations. In this region, water reservoirs serve as important sources of supply during long periods of drought; however, they frequently receive untreated sewage discharges. This practice fosters the maintenance of disease vector populations, such as schistosomiasis mansoni. The lack of information about the abundance and dynamics of these vectors over space and time, known as Prestonian shortfall, adds an extra layer of concern to the situation of the semi-arid reservoirs. This limited understanding hampers our ability to predict events and manage and effectively conserve freshwater mollusc populations. To bridge this gap, we investigated the effect of seasonality in the semi-arid region on the dynamics of Biomphalaria straminea populations, the primary vector of the Schistosoma mansoni in Caatinga reservoirs. We conducted monthly collections between June 2017 and May 2020 in three reservoirs in the municipality of São Julião, Piauí, located in urban and rural zones. Based on the literature, specimens were identified, measured, and categorised into young and adult individuals, and precipitation data were obtained from public government databases (INMET). We used GLMs and circular statistics to verify the existence of seasonal patterns in the abundance of molluscs. We recorded 5,555 specimens of B. straminea, with an average size of 5.11 mm. In terms of age composition, young individuals predominated (79%) compared to adults (p lt; 0.001; W = 9). We found that precipitation has a negative effect on the abundance of B. straminea (intercept = 5.52; coefficient = -1.08; R² = 0.41; p lt; 0.001), with the dry season (n = 3,411; 61%) presenting a higher number of individuals than the rainy season (n = 2,144; 39%). The dry season coincided with the highest abundance peak recorded in the reservoirs (rho = 0.6) and with a greater number of young individuals (n = 2,741) compared to adults (n = 629) compared to the rainy season (young = 1,667; adults = 518). We did not observe uniformity in the distribution of B. straminea abundances throughout the study period, indicating the presence of seasonal variations in the abundance of this species (Rayleigh test = 0.6099; p lt; 0.001). The abundance of the Biomphalaria straminea species during the dry season highlights the need for more effective surveillance and control strategies, considering the increased risk of helminthiases, especially schistosomiasis. This elevated risk is associated with environmental conditions favourable to vector proliferation at this time of year and with the increased density of animals and the greater demand for water resources in the reservoirs.

The purpose of this pilot study was to assess craniofacial morphology in young and adult individuals with cleidocranial dysplasia (CCD). Craniofacial morphology in young individuals (primary dentition) and in young adults was compared with control data using ratios and angles obtained from lateral head films. The CCD individuals were referred to the Center for Craniofacial Anomalies for diagnostic workup and treatment recommendations. The sample consisted of 14 Caucasians. The inclusion criterion for the young, prepubertal group (A) was complete primary dentition, and for the adult, postpubertal group (B), the eruption of all four first molars was required. No treatment other than extraction or surgical removal of selected primary or supernumerary teeth was performed. Both groups showed significantly smaller anterior upper face height compared with controls. Group B subjects demonstrated significantly smaller face height values than the controls in the A point-nasion-B point (ANB) angle, facial axis, mandibular plane angle, palatal plane/mandibular plane angle, and gonial angle. No significant differences were found between group A individuals and the controls for these measurements. The older group had shorter anterior lower face height compared with both anterior upper face height and posterior lower face height. Whereas young CCD subjects showed relatively normal jaw proportions and morphology of the mandible, older CCD individuals tended to have short lower face height, acute gonial angle, anterior inclination of the mandible, and mandibular prognathism. These differences can be attributed to pronounced horizontal mandibular growth resulting from lack of vertical maxillary growth and impaired eruption of permanent teeth.