The Federal University of Western Pará (Portuguese: Universidade Federal do Oeste do Pará, UFOPA) is a public university in the state of Pará, in northern Brazil.UFOPA was founded in 1970 as Núcleo de Educação em Santarém (NES), and was renamed UFOPA in 2009. It has an annual budget of 90 million real, and has over 400 faculty and over 10,000 students..
Multicomponent (Sm,Nd)3(Nb,Ta)O7 was synthesized by high-energy mechanical milling and investigated from mechanochemical formation to compression up to 50 GPa. After 22 h of milling, X-ray diffraction reveals a highly nanocrystalline orthorhombic weberite described by the C2221 space group, with a mean crystallite size of approximately 20 nm. Annealing at 800 °C for 3 h increases the mean crystallite size to approximately 26 nm, enhances structural coherence, and sharpens the Raman response while preserving the average weberite structure. In situ synchrotron X-ray diffraction shows anisotropic compression of the C2221 phase, with the b axis more compressible than a and c, and a second-order Birch–Murnaghan bulk modulus B0 = 145(3) GPa up to 19.5 GPa. Above ∼21 GPa, weakening and broadening of characteristic weberite reflections, together with increasing peak overlap and diffraction-pattern simplification, mark a progressive structural reorganization extending to ∼31 GPa. The high-pressure state remains crystalline to 50 GPa and can be described by a Cmcm-compatible higher-average-symmetry orthorhombic metric, although the broadened diffraction patterns do not permit an unequivocal space-group assignment or a reliable high-pressure equation of state. Raman spectroscopy independently reveals progressive broadening and coalescence of framework-related bands, whereas high-frequency (Nb,Ta)–O stretching features remain detectable to 50 GPa. The combined results indicate pressure-induced structural symmetrization in which long-range weberite distortions are suppressed while local structural heterogeneity persists.
Using nail plates to connect timber structural elements is a way to reduce costs and time during assembly, but moisture-induced backout can compromise these connections in the medium and long term. Most nail plate backout models proposed are based on a single tooth backout, and therefore, do not consider the influence of the metal plates at their bases. This study aimed to verify the effect of the plate connection on the backout. The dimensional changes, including a holistic approach to nail plate behaviour were evaluated in two treatments: S-D cycle, where wood started saturated and then dried to 0
This article introduces two matrix-variate asymmetric distributions for modeling data exhibiting skewness and latent scale variability: the matrix-variate shifted asymmetric Laplace (MVSAL) and the matrix-variate shifted generalized asymmetric Laplace (MVSGAL). Both distributions arise within the class of matrix-variate normal mean-variance mixtures, yielding a hierarchical representation that facilitates random generation and likelihood-based inference. Several structural properties are established, including closure under linear transformations and marginalization. An Expectation/Conditional Maximization (ECM) algorithm is developed for maximum likelihood estimation, and simulation results demonstrate accurate parameter recovery with improved stability as the sample size increases. An empirical application to seasonal climatic data from 100 municipalities in the state of São Paulo illustrates the practical use of the MVSGAL model in a multivariate matrix setting, capturing temporal persistence, cross-variable dependence, and asymmetric effects within a unified framework.
Climate and atmospheric changes are impacting forest function and structure worldwide, but their effects on tropical forest diversity are unclear. Nowhere is the scientific challenge greater than in the Andes and the Amazon, which together include the world’s most diverse forests. Here, using 406 permanent plots spanning four decades of intact lowland and montane forest dynamics, we test for long-term change in species richness and assess the influence of climate and other variables. We show that, at a continental scale, species richness appears stable, but this masks substantial regional variation. Species richness increased in Northern Andean and Western Amazon plots, yet declined in the Central Andes, Guyana Shield and Central-Eastern Amazon. Overall, warmer, drier and more seasonal forests lost species, while those at higher elevations, in less fragmented areas and with faster rates of tree turnover experienced increases. Region-specific drivers, particularly precipitation seasonality and demographic factors, modulated these trends. The results highlight the diverse ways in which Amazon–Andes forests are changing and underscore the critical need to preserve large-scale ecosystem integrity to maintain local tree diversity. By doing so, Northern Andean forests in particular could serve as an important refuge for species increasingly displaced by climate change. This study examines long-term changes in species richness across tropical forests in the Andes and Amazon. Hotter, drier and more seasonal forests in the eastern and southern Amazon are losing species, while Northern Andean forests are accumulating species, acting as a refuge for climate-displaced species.
A multi-similarity Siamese neural network unifies zero-day anomaly detection and one-shot classification in optical networks, achieving over 99% accuracy and instant adaptability across lightpaths and unseen anomaly types without any retraining.
