Cetaceans face multiple threats, and pollution has become a major concern for their conservation worldwide. This study assessed metal(loid) concentrations in the tissues of two odontocete species with coastal and oceanic habits, namely Guiana dolphin (Sotalia guianensis; n = 11) and the false killer whale (Pseudorca crassidens; n = 8), respectively, stranded along the northeastern Brazilian equatorial margin. Silver (Ag), copper (Cu), cadmium (Cd), mercury (Hg), and selenium (Se) were determined in samples of liver, muscle, and kidney, expressed as mean ± standard deviation (SD), in µg g⁻¹ wet weight. In P. crassidens, Hg was detected in all individuals, with hepatic concentrations (794.1 ± 556.9 µg g⁻¹) higher than those in muscle (30.2 ± 16.7 µg g⁻¹); females exhibited higher levels than males in both tissues. In S. guianensis, mean Hg levels were also higher in the liver (1.6 ± 2.4 µg g⁻¹) compared to muscle (0.4 ± 0.4 µg g⁻¹), with the highest concentration detected in the kidney (3.1 µg g⁻¹). Detectable Cd concentrations occurred only in one juvenile (0.3 µg g⁻¹, liver). For Cu, Ag, and Se, values varied between species and tissues. The observed differences between species, as well as among sexes, age classes, and tissues, suggest that physiological factors, diet, and exposure time influence metal accumulation. These findings highlight the importance of considering the role of coastal versus oceanic habitat use, trophic ecology, and life history in the bioaccumulation of metal(loid)s since some of these factors were not assessed (i.e., trophic ecology).
The Martins-Portalegre Plateau, located in the semiarid region of the state of Rio Grande do Norte, Brazil, harbors a hydrological heritage of significant regional importance. However, the lack of (re)cognition by both local populations and public administrators has contributed to the degradation of its Sites of Hydrological Interest (SHI). This study aims to classify twelve (12) Hydrologically Significant Sites based on ecological, aesthetic, sociocultural, and complementary criteria. Among the twelve sites assessed, two were classified as hydrosites and eight as potential hydrosites, with particular emphasis on the Umarizeira Waterfall and the Brejo Spring, due to their highest overall scores. Two sites were categorized as non-hydrosites, primarily due to their low ecological ratings. The findings suggest that, despite their intrinsic value and unique characteristics, some of these sites are neither adequately preserved nor sustainably managed, particularly in the context of tourism. Therefore, it is essential that public administrators implement geoconservation programs specifically targeting these areas in order to maintain the quality of existing attributes while improving the conditions of more vulnerable sites, potentially allowing their reclassification into categories of higher heritage value.
A bacia hidrográfica do rio Apodi-Mossoró tem uma importante influência no desenvolvimento econômico da região. A falta de análise do espaço físico e o manejo inadequado do uso do solo promovem impactos no sistema ambiental, como erosão e assoreamento do sistema de drenagem, dentre outros fatores. O presente trabalho tem como objetivo apresentar, por meio do mapeamento, de que forma os diferentes tipos de uso da terra influenciam nos níveis de fragilidade ambiental para o entendimento dos processos de degradação da bacia hidrográfica do rio Apodi-Mossoró – RN. Assim, o mapeamento da fragilidade potencial e emergente se torna importante ferramenta na identificação de áreas com níveis de fragilidade, fornecendo subsídios para o desenvolvimento sustentável dessas áreas. Nos trabalhos de laboratório, foram utilizados arquivo, em formato de shapefile, para os tipos de solos da bacia, Modelo Digital de Elevação e Imagens de Satélite. Por meio do mapeamento, foi possível avaliar e quantificar os níveis de fragilidade da bacia hidrográfica, de modo que o nível predominante na bacia é o de fragilidade média, sendo superior a 50%, seguido de fragilidade alta com 38,4%. A cobertura vegetal nas áreas de maiores declividades foi importante na mitigação de áreas com fragilidade potencial muito alta e alta.
Magnetic nanoparticles functionalized with diethylenetriaminepenta(methylene phosphonic acid) and activated with glutaraldehyde were designed as a heterofunctional support for immobilizing Eversa Transform 2.0 lipase. Structural characterization by X-ray diffraction, transmission and scanning electron microscopies, X-ray fluorescence, Fourier-transform infrared spectroscopy, thermogravimetry, and vibrating-sample magnetometry confirmed preservation of the magnetite spinel phase, spherical primary nanoparticles of approximately 16 nm, progressive organic coating, and magnetic responsiveness after enzyme loading. Molecular docking suggested that glutaraldehyde can act as an interfacial bridge between accessible lysine residues of the lipase and the phosphonate-functionalized surface, with calculated interaction energies of − 6.0 to − 3.6 kcal mol−1 for lysine-glutaraldehyde contacts and − 5.4 to − 3.2 kcal mol−1 for the phosphonate-glutaraldehyde-lysine complex. A Taguchi L9 design identified protein loading and ionic strength as the most influential immobilization variables, and the optimized condition was 6 h, 5 mM buffer, 5 mg enzyme per g support, and 40 °C.Under these conditions, the immobilized biocatalyst reached 60.5 ± 1.4
Molecular magnets, although analogous to familiar macroscopic magnets, offer a platform for next generation magnetic storage technologies with far higher data densities and prospective applications in quantum information science. When exposed to an external magnetic field, single molecule magnets enter a metastable configuration that is exceptionally sensitive to low energy excitations. Energy deposited by a dark matter particle can trigger the relaxation of a metastable molecule, releasing Zeeman energy that subsequently propagates through neighboring molecules. This magnetic avalanche encodes the energy deposited in the initial excitation. By combining concepts from chemistry, condensed matter physics, and particle physics, we show that dysprosium and manganese molecules can achieve more than an order of magnitude improvement in sensitivity to dark photon and QCD axion models, respectively, compared with existing detection methods.
