Universidade Federal da Paraíba

Pasture Management and Mineral Fertilization on Soil Properties, Plant Nutrition, and Biomass Production of Urochloa decumbens in Tropical Lixisols

Pasture management and mineral fertilization are key factors influencing soil fertility and pasture yield. However, their effects on the soil properties of Lixisols in the Brazilian semi-arid region, and their subsequent impact on Urochloa decumbens biomass production, remain unc...

Silicon Fertigation and Azospirillum brasilense Modulate the Microbiological Profile of Total Mixed Ration Silage for Dairy Goats

The objective of this study was to evaluate the effects of fertigation with silicon (Si) combined with inoculation with Azospirillum brasilense during off-season corn cultivation on the fermentation profile, microbiological quality, and chemical and bromatological composition of...

Global Existence and Exponential Stability of a Boundary Contact Problem for the 2D Mindlin–Timoshenko System

Abstract We analyze a contact problem for the two-dimensional Mindlin–Timoshenko system describing the vibratory motion of elastic plates in unilateral contact with a rigid obstacle along a portion of the boundary. Precisely, we establish the existence of solutions and prove that...

Insecticidal Activity of Essential Oils from Syzygium aromaticum and Foeniculum vulgare Var. dulce and Their Major Compounds Against Spodoptera frugiperda and Physiological Selectivity for Trichogramma pretiosum

Spodoptera frugiperda (Lepidoptera: Noctuidae) causes significant losses in major crops and is mainly controlled with chemical insecticides and genetically modified plants; however, improper use of these strategies has led to the development of resistant populations. We evaluated...

Spatially explicit modeling of future land use and land cover dynamics in the São Francisco River Basin, Brazil

Future land use and land cover (LULC) changes in major Brazilian river basins may pose substantial challenges for water resource management by altering streamflow regimes, reducing water availability, affecting ecosystem services, and increasing pressure on vulnerable hydrologica...

Fermi acceleration mechanisms beyond Lorentz symmetry

Abstract We construct models for first- and second-order Fermi acceleration of particles, incorporating generic frame transformations, dispersion relations, and conservation laws. Within this framework, we study deformations of Lorentz symmetry via the $$\kappa $$ κ -Poincaré alg...

Existence of Hypercyclic Algebras in Fréchet Algebras

Abstract We prove that every separable infinite-dimensional Fréchet algebra X admits a continuous linear operator T supporting a dense invariant hypercyclic algebra, giving an affirmative answer to a question of Bayart, Costa Jr. and Papathanasiou. In fact, every dense countable-...

An observational assessment of soil physical, chemical, and biological attributes under contrasting land-use systems in Eastern Maranhão, Brazil

Abstract The adoption of integrated crop–livestock production systems, together with practices such as crop rotation, crop succession, and intercropping, has increased the need for integrated approaches to assess soil health. This study evaluated soil health under contrasting lan...

Carroll–Field–Jackiw term in nonlocal Lorentz-violating QED

Abstract We investigate the radiative generation of the Carroll–Field–Jackiw (CFJ) term in nonlocal Lorentz- and CPT-violating extensions of quantum electrodynamics. Nonlocality is introduced in the fermionic sector through entire form factors depending on the Dirac operator. Usi...

Co-pyrolysis of sewage sludge and coffee husk produces NPK-enriched biochar with improved carbon stability indicators

Sewage sludge (SS) is a nutrient-rich waste, but it typically yields biochars with high ash content, low K concentration, and limited C stability. In contrast, coffee husk (CH) is a lignocellulosic residue rich in K and organic carbon. This study evaluated how co-pyrolysis of SS...

Fermionic Casimir effect in an axial Lorentz-violating background

Abstract We investigate the fermionic Casimir effect for a Dirac field confined between two parallel plates with MIT bag boundary conditions in the presence of CPT-odd Lorentz symmetry violation described by a constant axial background vector $$b_{\mu }$$ b μ . The exact mode qua...

Unveiling Latent Market Dynamics: A Hidden Markov Framework for Informed Trading

Abstract The Probability of Informed Trading (PIN) treats informational events as independent across trading days, leaving it silent on how long informational regimes last. We propose the Hidden Probability of Informed Trading (HPIN), which lets the informational state evolve as...

Ecosystem Resilience and Land-Use Governance: Remote Sensing Insights for Environmental Management in a Tropical Dry Forest

Seasonally Dry Tropical Forests (SDTFs), such as the Brazilian Caatinga, are highly vulnerable to climate change and chronic anthropogenic disturbances. Despite extensive land-use conversion, understanding how vegetation productivity and resilience vary across different land gove...

Vision, hearing, and intellectual disabilities in school-age children and adolescents (5–19 years) in Latin America and the Caribbean

Background Childhood sensory and intellectual disabilities represent significant yet under-recognized barriers to learning and human capital development. This study analyzes prevalence and severity of these conditions among 149.3 million children and adolescents aged 5–19 years a...

Gravitational wave signatures and periodic orbits of a charged black hole in a Hernquist dark matter halo

Abstract In this work, we study the motion of massive test particles and the gravitational wave emission associated with periodic trajectories around a magnetically charged black hole immersed in a Hernquist dark matter halo. We begin by analyzing the effective potential and the...

MoO3/ZnMoO4 Composite Obtained in a One-Pot Reaction and Applied in the Production of Biodiesel from Acid Feedstocks

Abstract Despite being widely recognized within the scientific community, the synthesis of biodiesel from acidic feedstocks remains challenging. In this work, a heterogeneous catalyst comprising molybdenum trioxide and zinc molybdate (MoO3/ZnMoO4) was synthesized via the modified...

EGFR-AI Drug Discovery Computational Workflow

This software repository contains the computational workflow developed for an EGFR-targeted artificial intelligence (AI)-assisted drug discovery study. The project includes source code and computational scripts for AI/ML-based analysis, molecular generation, molecular docking, mo...

Scalar fields, impurities and supersymmetry

Abstract We develop a rigid $$\mathcal {N}=(1,1)$$ N = ( 1 , 1 ) superspace formulation for multifield scalar models coupled to localized impurities through spurion superfields in two-dimensional spacetime. The spurionic completion gives a manifestly supersymmetric action and pro...

Intravenous Thrombolysis for Minor Ischemic Stroke in Chinese Populations: A Secondary Meta-Analysis of Comparative Cohort Studies

The effectiveness and safety of intravenous thrombolysis (IVT) in minor ischemic stroke (MIS) remain uncertain in Chinese populations. We performed a secondary meta-analysis of cohort studies identified in a systematic review and meta-analysis, restricting the analysis to studies...

Neutrino oscillations in a Kalb–Ramond black hole background

Abstract The analysis examines how neutrinos behave when their trajectories unfold around a black hole sourced by a Kalb–Ramond field, where spontaneous Lorentz symmetry-breaking reshapes the surrounding geometry. Instead of following the conventional order, the study focuses fir...