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Mental disorders can have a major impact on brain development. Peripheral blood concentrations of brain-derived neurotrophic factor (BDNF) are lower in adult psychiatric disorders. Serum BDNF concentrations and BDNF genotype have been associated with cortical maturation in children and adolescents. In 2 large independent samples, this study tests associations between serum BDNF concentrations, brain structure, and psychopathology, and the effects of BDNF genotype on BDNF serum concentrations in late childhood and early adolescence.
Children and adolescents (7-14 years old) from 2 cities (n = 267 in Porto Alegre; n = 273 in São Paulo) were evaluated as part of the Brazilian high-risk cohort (HRC) study. Serum BDNF concentrations were quantified by sandwich ELISA. Genotyping was conducted from blood or saliva samples using the SNParray Infinium HumanCore Array BeadChip. Subcortical volumes and cortical thickness were quantified using FreeSurfer. The Development and Well-Being Behavior Assessment was used to identify the presence of a psychiatric disorder.
Serum BDNF concentrations were not associated with subcortical volumes or with cortical thickness. Serum BDNF concentration did not differ between participants with and without mental disorders, or between Val homozygotes and Met carriers.
No evidence was found to support serum BDNF concentrations as a useful marker of developmental differences in brain and behavior in early life. Negative findings were replicated in 2 of the largest independent samples investigated to date.
This study aimed to calculate economic values (EVs) and economic selection indices for milk production systems in small rural properties. The traits 305-d milk yield in kg (MY), fat (FP) and protein (PP) percentage, daily fat (FY) and protein (PY) yield, cow live weight in kg (LW), calving interval (CI), and logarithm of daily somatic cell count (SCC) in milk were considered the goals and selection criteria. The production systems were identified from 29 commercial properties based on the inventory of revenues and costs and of zootechnical field data. Later, bioeconomic models were developed to calculate the productive performance, revenues, and costs concerning milk production to estimate EVs, which were calculated as the difference in annual profit with dairy production resulting from a change in one unit of the trait while keeping the others constant and dividing the value by the number of cows. After the EVs were known, ten economic selection indices were estimated for each system so they could be compared by modifying the selection criteria and calculating the relative importance of each selection criteria, the accuracy of the economic selection index, and response expected to the selection in USD, among other parameters. One of the systems detected was called less intensive (LS) and was characterized by having ten cows in lactation that produced 13·5 l/d and consumed 1·8 kg of concentrate/d. The second system detected was called more intensive (IS) and had 22 cows in lactation that produced 17·5 l/d and consumed 3·4 kg of concentrate/d. Monthly profits per cows in lactation of USD 2·60 and USD 68·77 were recorded for LS and IS, respectively. The EVs of the traits MY, FP, and PP were all positive, while for the other traits they were all negative in all situations. The best economic selection indices were those featuring selection criteria MY, LW, and CI, while the trait LW had the greatest importance in both systems. These results indicate that animal frame must be controlled in order to maximize the system's profit.
Recently, a new class of carbon allotrope called protomene was proposed. This new structure is composed of sp2 and sp3 carbon-bonds. Topologically, protomene can be considered as an sp3 carbon structure (∼80% of this bond type) doped by sp2 carbons. First-principles simulations have shown that protomene presents an electronic bandgap of ∼3.4 eV. However, up to now, its mechanical properties have not been investigated. In this work, we have investigated protomene mechanical behavior under tensile strain through fully atomistic reactive molecular dynamics simulations using the ReaxFF force field, as available in the LAMMPS code. At room temperature, our results show that the protomene is very stable and the obtained ultimate strength and ultimate stress indicates an anisotropic behavior. The highest ultimate strength was obtained for the x-direction, with a value of ∼110 GPa. As for the ultimate strain, the highest one was for the z-direction (∼25% of strain) before protomene mechanical fracture.
Micronutrients are indispensable for adequate metabolism, such as biochemical function and cell production. The production of blood cells is named haematopoiesis and this process is highly consuming due to the rapid turnover of the haematopoietic system and consequent demand for nutrients. It is well established that micronutrients are relevant to blood cell production, although some of the mechanisms of how micronutrients modulate haematopoiesis remain unknown. The aim of the present review is to summarise the effect of Fe, Mn, Ca, Mg, Na, K, Co, iodine, P, Se, Cu, Li and Zn on haematopoiesis. This review deals specifically with the physiological requirements of selected micronutrients to haematopoiesis, showing various studies related to the physiological requirements, deficiency or excess of these minerals on haematopoiesis. The literature selected includes studies in animal models and human subjects. In circumstances where these minerals have not been studied for a given condition, no information was used. All the selected minerals have an important role in haematopoiesis by influencing the quality and quantity of blood cell production. In addition, it is highly recommended that the established nutrition recommendations for these minerals be followed, because cases of excess or deficient mineral intake can affect the haematopoiesis process.
Bioactive molecules isolated from plants are promising sources for the development of new therapies against leishmaniasis. We investigated the leishmanicidal activity of cariphenone A (1), isouliginosin B (2) and uliginosin B (3) isolated from Hypericum species. Promastigotes and amastigotes of Leishmania amazonensis were incubated with compounds 1–3 at concentrations 1–100 µm for 48 h. The anti-promastigote effect of compounds was also tested in combinations. The cytotoxicity against macrophages and human erythrocytes were determined using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) method and hemolysis assay, respectively. The compounds 1–3 showed high leishmanicidal activity against promastigotes, IC50 values of 10.5, 17.5 and 11.3 µm, respectively. Synergistic interactions were found to the associations of compounds 1 and 2 [Σ fractional inhibitory concentration (FIC) = 0.41], and 2 and 3 (ΣFIC = 0.28) on promastigotes. All Hypericum compounds induced mitochondrial hyperpolarization and reactive oxygen species production in promastigotes. The compounds showed low cytotoxicity toward mammalian cells, high selectivity index and killed intracellular amastigotes probably mediated by oxidative stress. These results indicate that these compounds are promising candidates for the development of drugs against leishmaniasis.
Although serological assays have been widely used for the diagnosis of canine visceral leishmaniasis (CVL), they present different performances depending on the clinical profile of the dogs. This study evaluated the accuracy of serological tests, immunochromatographic (Dual Path Platform: DPP®) and enzyme-linked immunosorbent (ELISA EIE®), for CVL in relation to the detection of Leishmania DNA through real-time polymerase chain reaction (real-time PCR) in samples from symptomatic and asymptomatic dogs from a non-endemic area in the state of Rio Grande do Sul, Southern Brazil. Serum from 140 dogs (39 symptomatic and 101 asymptomatic) was tested by DPP and ELISA followed by real-time PCR. From a total of 140 samples evaluated, Leishmania DNA was detected by real-time PCR in 41.4% (58/140). Moreover, 67.2% of samples positive in real-time PCR were positive in both DPP and ELISA (39/58), showing moderate agreement between methods. In the symptomatic group, one sample non-reactive in both serological assays was positive in real-time PCR, whereas in the asymptomatic group, 17.8% non-reactive or undetermined samples in serological assays were positive in the molecular method. Leishmania DNA was not detected in 17.9% reactive samples by serological assays from the symptomatic group, and in 3.9% from asymptomatic dogs. Real-time PCR demonstrated greater homogeneity between symptomatic and asymptomatic groups compared with DPP and ELISA. The molecular method can help to establish the correct CVL diagnosis, particularly in asymptomatic dogs, avoiding undesirable euthanasia.
Graphene is a very promising material for nanoelectronics applications due to its unique and remarkable electronic and thermal properties. However, when deposited on metallic electrodes the overall thermal conductivity is significantly decreased. This phenomenon has been attributed to the mismatch between the interfaces and contact thermal resistance. Experimentally, one way to improve the graphene/metal contact is through high-temperature annealing, but the detailed mechanisms behind these processes remain unclear. In order to address these questions, we carried out fully atomistic reactive molecular dynamics simulations using the ReaxFF force field to investigate the interactions between multi-layer graphene and metallic electrodes (nickel) under (thermal) annealing. Our results show that the annealing induces an upward-downward movement of the graphene layers, causing a pile-driver-like effect over the metallic surface. This graphene induced movements cause a planarization (thermal polishing-like effect) of the metallic surface, which results in the increase of the effective graphene/metal contact area. This can also explain the experimentally observed improvements of the thermal and electric conductivities.
The search for new ultra strong materials has been a very active research area. With relation to metals, a successful way to improve their strength is by the creation of a gradient of nanograins (GNG) inside the material. Recently, R. Thevamaran et al. [Science v354, 312-316 (2016)] propose a single step method based on high velocity impact of silver nanocubes to produce high-quality GNG. This method consists of producing high impact collisions of silver cubes at hypersonic velocity (∼400 m/s) against a rigid wall. Although they observed an improvement in the mechanical properties of the silver after the impact, the GNG creation and the strengthening mechanism at nanoscale remain unclear. In order to gain further insights about these mechanisms, we carried out fully atomistic molecular dynamics simulations (MD) to investigate the atomic conformations/rearrangements during and after high impact collisions of silver nanocubes at ultrasonic velocity. Our results indicate the co-existence of polycrystalline arrangements after the impact formed by core HCP domains surrounded by FCC ones, which could also contribute to explain the structural hardening.
Seasonal fluctuations in bird abundance are expected in semi-arid environments, but estimates may be biased if detectability is not considered. In a tropical dry forest in north-eastern Brazil, we evaluated whether bird abundance is highly seasonal, and associated with time-specific variability in detectability. We mark-recaptured birds with mist nets over three field visits (3487 records from 75 species), and used closed-capture models to estimate detectability and abundance in birds divided into three groups (all, residents, insectivores). In the two dry periods, the best models resulted in capture estimates at least three times larger than recapture, and both estimates were twice that of when rains occurred on the day preceding sampling. Abundance varied between dry and wet periods from 4.0 (from 115 ± 34 to 479 ± 144) to 13 times (183 ± 8 to 2463 ± 351). Estimates were 1.5–3.2 times greater in the dry period when behavioural responses of birds were excluded from capture-recapture models. Meanwhile, in the wet period the relative abundance was between 33–76% smaller than best-fit models estimated. This study found variation in avian abundance greater than that observed in other Neotropical dry forests, and indicates that biases may be common when not including detectability.
The article examines the role played by the Portuguese oppositionist diaspora in the final years of the Estado Novo dictatorship (c. 1968–c.1974). It advances an explanation for the apparent lack of success met by several exile groups when trying to persuade the Western democracies to withdraw (or at least reduce) their support for Lisbon's authoritarian regime during a period in which the public was increasingly aware of human rights abuses. The choice of this particular juncture is justified for several reasons. Firstly, it was a time of renewed expectations regarding a possible liberalisation of the regime in the aftermath of the replacement of the incapacitated Oliveira Salazar by the younger Marcelo Caetano (September 1968), an event that confronted the different sections of the Portuguese opposition with a number of dilemmas, both at home and abroad, and exposed rifts that would take some time to repair. Secondly, this was also an epoch of momentous social and cultural change in Europe, with obvious ramifications for the political orientations and attitudes of those who, for different reasons, had decided to leave Portugal in the 1960s. Finally, the vicissitudes of the East–West détente are seen here as equally important for understanding the opportunities and limitations of the anti-Estado Novo opposition abroad.
The present study aimed to evaluate the association of 4-year-old children’s dietary patterns with adiposity at 7 years, according to child’s sex, using a conceptual model.
Prospective cohort study. Diet was assessed using an FFQ. Age- and sex-specific BMI standard deviation scores (Z-scores) were defined according to the WHO. Fat mass percentage (FM%), fat mass index (FMI) and waist-to-height ratio (WHtR) were also considered, converted into Z-scores using sex-specific means and standard deviations of the current sample. Dietary patterns were identified by latent class analysis and their association with adiposity was estimated by linear regression models.
Population-based birth cohort Generation XXI (Porto, Portugal, 2005–2006).
Children (n 3473) evaluated at both 4 and 7 years of age.
Three dietary patterns were identified: high in energy-dense foods (EDF); low in foods typically consumed at main meals and intermediate in snacks (Snacking); and higher in vegetables and fish and lower in EDF (Healthier, reference). The EDF dietary pattern at 4 years of age was positively associated with later BMI only in girls (β=0·075, 95 % CI 0·009, 0·140, P-interaction=0·046). The EDF dietary pattern was also associated with other adiposity indicators only in girls (FMI: β=0·071, 95 % CI 0·000, 0·142; WHtR: β=0·094, 95 % CI 0·023, 0·164). Snacking was not significantly associated with any marker of adiposity in either girls or boys.
Although dietary patterns and adiposity persisted across the two ages in both sexes, EDF at 4 years of age increased adiposity at 7 years of age only in girls.
The rapid spread of glyphosate-resistant sourgrass populations generates concern in the agricultural production sector in Brazil. Nonetheless, there is not much information related to the frequency and dispersion of sourgrass throughout recent years. We investigated the frequency and dispersion of glyphosate-resistant sourgrass populations in Brazilian agricultural regions as part of a larger-scale weed resistance monitoring study. A discriminatory rate of 960 g ae ha−1 of glyphosate was used on plants at the 2- to 3-tiller stage, originating from 2,593 populations of sourgrass sampled in 329 counties in 14 Brazilian states between 2012 and 2015. The dispersion of sourgrass populations originated in western Paraná State, next to the Paraguay border, where the first resistance case was reported. Its dispersion to the central region of Brazil, mainly in soybean-producing areas, is most likely a consequence of agricultural equipment movement and wind-mediated dispersal. Glyphosate-resistant sourgrass populations were found in every geographical region across all Brazilian states tested. These data highlight the importance of an appropriate weed resistance monitoring program to track the evolution and dispersion of resistance to mitigate these issues by focusing efforts regionally and raising awareness among stakeholders in each region.
The loss of biodiversity in transitional forests between the Cerrado and Amazonia, the two largest neotropical phytogeographic domains, is an issue of great concern. This extensive region is located within the ‘arc of deforestation’ zone where tropical forests are being lost at the fastest rate on the planet, but floristic diversity and variation among forests here is still poorly understood. We aimed to characterize the floristic composition of forests in this zone and explored the degree and drivers of differentiation within and across Araguaia and Xingu watersheds. In 10 sites we identified all trees with diameter ≥10 cm; these totaled 4944 individuals in 257 species, 107 genera and 52 families. We evaluated the data for multivariate variation using TWINSPAN and DCA to understand the species distribution among sites. There was a larger contribution from the Amazonian flora (169 species) than that of the Cerrado (109) to the transitional forests. Remarkably, 142 species (55%) were restricted to only one sampling site, while 29 species (>16%) are endemic to Brazil, suggesting potentially large loss of species and unique forest communities with the loss and fragmentation of large areas. Our results also suggest that watersheds may be a critical factor driving species distribution among forests in the Amazonian–Cerrado transition zone, and quantifying their role can provide powerful insight into devising better conservation strategies for the remaining forests.
The Radiocarbon Laboratory of the Universidade Federal Fluminense, in Brazil, has been successfully applying the zinc reduction method for graphitization of carbon samples since the development of its early protocols in 2009. Successive methodological research aiming to improve and, ultimately, optimize the precision and accuracy of our results indicates that graphitization temperatures as low as 460°C promote erratic 13C isotopic fractionation, but an approximately constant fractionation of about –5‰ is achieved at 520°C. In this work, we present isotope ratio mass spectrometry (IRMS) δ13C results for 14C reference materials graphitized at 550°C with variable amounts of zinc. Based on the results obtained from the addition of 20, 35, and 50 mg of zinc, we conclude that a slightly lower variation in 13C isotope fractionation during graphitization is obtained with less zinc. Moreover, the average isotopic fractionation is not altered by increasing the graphitization temperature from 520°C to 550°C.
Despite the ecological relevance of tropical reefs, information on species composition and coverage on sandstone reefs is very scarce. Most studies on reef systems have been conducted for true coral reefs, ecosystems that show calcareous formations with extensive coral cover and diversity. The aim of this study was to analyse the coverage of benthic assemblages in a submerged sandstone reef (22–24 m) in a relatively non-explored region (Tropical South-western Atlantic). In this area, filamentous algae (43.6%) and sponges (19.6%) are the main components of the benthic reef assemblages. Other benthic reef fauna (ascidians, corals and zoanthids) showed lower coverage, although their importance may vary depending on the area. A negative correlation between filamentous algae and slow-growing reef-building organisms (calcareous algae) was observed. High sand coverage (19.6%) over the reef revealed a high rate of silting. A low coral diversity (only two resilient species) was quantified, and most of the coral colonies were small-sized. The results provide a baseline assessment for a poorly known ecosystem with turbid-water benthic communities and higher sea-surface temperatures near the Earth's equator.
The work described in this paper is part of the development of a framework to support the joint execution of cooperative missions by a group of vehicles, in a simulated, augmented, or real environment. Such a framework brings forward the need for formal languages in which to specify the vehicles that compose a team, the scenario in which they will operate, and the mission to be performed. This paper introduces the Scenario Description Language (SDL) and the Team Description Language (TDL), two Extensible Markup Language based dialects that compose the static components necessary for representing scenario and mission knowledge. SDL provides a specification of physical scenario and global operational constraints, while TDL defines the team of vehicles, as well as team-specific operational restrictions. The dialects were defined using Extensible Markup Language schemas, with all required information being integrated in the definitions. An interface was developed and incorporated into the framework, allowing for the creation and edition of SDL and TDL files. Once the information is specified, it can be used in the framework, thus facilitating environment and team specification and deployment. A survey answered by practitioners and researchers shows that the satisfaction with SDL+TDL is elevated (the overall evaluation of SDL+TDL achieved a score of 4 out of 5, with 81%/78.6% of the answers ≥4); in addition, the usability of the interface was evaluated, achieving a score of 86.7 in the System Usability Scale survey. These results imply that SDL+TDL is flexible enough to represent scenarios and teams, through a user-friendly interface.
Research suggests that repeatedly offering infants a variety of vegetables during weaning increases vegetable intake and liking. The effect may extend to novel foods. The present study aimed to investigate the impact of advising parents to introduce a variety of single vegetables as first foods on infants' subsequent acceptance of a novel vegetable. Mothers of 4- to 6-month-old infants in the UK, Greece and Portugal were randomised to either an intervention group (n 75), who received guidance on introducing five vegetables (one per d) as first foods repeated over 15 d, or a control group (n 71) who received country-specific ‘usual care’. Infant's consumption (g) and liking (maternal and researcher rated) of an unfamiliar vegetable were assessed 1 month post-intervention. Primary analyses were conducted for the full sample with secondary analyses conducted separately by country. No significant effect of the intervention was found for vegetable intake in the three countries combined. However, sub-group analyses showed that UK intervention infants consumed significantly more novel vegetable than control infants (32·8 (sd 23·6) v. 16·5 (sd 12·1) g; P =0·003). UK mothers and researchers rated infants' vegetable liking higher in the intervention than in control condition. In Portugal and Greece, there was no significant intervention effect on infants' vegetable intake or liking. The differing outcome between countries possibly reflects cultural variations in existing weaning practices. However, the UK results suggest in countries where vegetables are not common first foods, advice on introducing a variety of vegetables early in weaning may be beneficial for increasing vegetable acceptance.
Appropriate legislation based on in-depth ecological evidence is essential for ecosystem conservation. Wetland areas in the Brazilian Cerrado hotspot are facing difficulties in terms of status under environmental law: only those wetlands with the palm Mauritia flexuosa (veredas) are recognized as protected. Comprehensive fieldwork in central-western Brazil (72 50-m transects) coupled with both exploratory and confirmatory analyses showed that communities with (MP) and without (MA) M. flexuosa are similar in terms of the floristics and ecology. The results demonstrate that the analysed wetlands are part of a continuum, in which a gradual replacement of species and community structure occurs without a pattern related to physiognomy. Considering such floristic and structure patterns when legally defining the ecosystem would promote a more comprehensive and realistic view of the ecosystem's characteristics and functions, and result in laws with a stronger scientific support. Conservationists should further examine the lack of consistent separation of plant community attributes between the MP and MA areas, and reconsider the scientific definition of veredas.