Variation in the diet composition and weight-length relationship of small characids in urbanized and forested streams.

The diet of indicator fish species plays a crucial role in assessing ecosystem health. This study evaluated streams with and without urban influences, focusing on abiotic parameters and the trophic ecology of Psalidodon fasciatus and Piabina argentea. Forested streams exhibited higher redox potential, dissolved oxygen, transparency, and depth, whereas urban streams had higher temperatures, greater widths, and increased levels of total dissolved solids, conductivity, total coliforms, and thermotolerant coliforms.

SARS-CoV-2 Immunization Index in the Academic Community: A Retrospective Post-Vaccination Study.

Background/objectives: The COVID-19 pandemic has revolutionized vaccine production and compelled a massive global vaccination campaign. This study aimed to estimate the positivity and levels of SARS-CoV-2 IgG antibodies acquired due to vaccination and infection in the academic population of a Portuguese university.

Methods: Blood samples were collected and analyzed through the ELISA methodology, and statistical analysis was performed.

Angiotensin peptides enhance SARS-CoV-2 spike protein binding to its host cell receptors.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the virus that caused the Coronavirus Disease 2019 (COVID-19) pandemic, has a spike glycoprotein that is involved in recognizing and fusing to host cell receptors, such as angiotensin-converting enzyme 2 (ACE2), neuropilin-1 (NRP1), and AXL tyrosine-protein kinase. Since the major spike protein receptor is ACE2, an enzyme that regulates angiotensin II (1-8), this study tested the hypothesis that angiotensin II (1-8) influences the binding of the spike protein to its receptors. While angiotensin II (1-8) did not influence spike-ACE2 binding, we found that it significantly enhances spike-AXL binding.

Optimal Brain Targets for Enhancing Vocal Performance With Transcranial Direct Current Stimulation.

Transcranial direct current stimulation (tDCS) can be used to temporarily and reversibly modulate brain functions and is an increasingly utilized tool to investigate the relationships between brain and behavior. This study aimed to identify the brain area where tDCS has the greatest effect on vocal quality, vocal range, neuromotor functioning of the larynx, and self-reported vocal effort in vocally healthy individuals. Sixteen adults, non-singers, with a mean age of 22.

Cryo-electron tomography of eel sperm flagella reveals a molecular "minimum system" for motile cilia.

Cilia and flagella play a crucial role in the development and function of eukaryotes. The activity of thousands of dyneins is precisely regulated to generate flagellar motility. The complex proteome (600+ proteins) and architecture of the structural core of flagella, the axoneme, have made it challenging to dissect the functions of the different complexes, like the regulatory machinery.