How do extreme fluctuations in water level affect fish condition in Amazonian Floodplain Lakes?

The annual flood pulse is a defining feature of Amazonian floodplain lakes, creating a highly variable environment that influences resource availability, such as food and habitat. These cyclical changes necessitate a high degree of adaptability among fish species, many of which have evolved specialized strategies to cope with the fluctuating conditions. In 2023, the Amazon basin experienced a record-breaking drought event, leading to mass mortality of Amazonian fish and other wildlife.

Dissolved organic carbon from "white" waters in Amazon basin (Brazil) and the osmoregulatory responses of tambaqui (Colossoma macropomum) in neutral and acidic environments.

Optical characterization of dissolved organic carbon (DOC) freshly collected from the circumneutral "white water" of the Rio Solimoes revealed that it had lower aromaticity, lower molecular weight, and a greater autochthonous content than DOC from the acidic "black water" of the Rio Negro. The tambaqui (Colossoma macropomum), a characid member of the Serrasalmidae, is a model neotropical fish that migrates annually between the two rivers. We analysed ionoregulatory responses of the tambaqui over 24 h in ion-poor water at pH 7.

The Connection Between Stress and Women's Smoking During the Perinatal Period: A Systematic Review.

Introduction: In women, smoking during pregnancy and the postpartum period has important consequences for maternal and infant health, and interventions to assist smoking cessation during this period are essential. Although smoking has been associated with the presence of mental health problems, few studies addressing the factors associated with perinatal smoking have examined the role of stress. The aim of this review was to identify the relationships between the presence of stress and smoking during pregnancy and the postpartum period.

Accuracy and clinical applicability of plasma tau 181 and 217 for Alzheimer's disease diagnosis in a memory clinic cohort.

Plasma tau phosphorylated at threonine 181 (p-tau181) and 217 (p-tau217) have demonstrated high accuracy for Alzheimer's disease (AD) diagnosis, defined by CSF/PET amyloid beta (Aβ) positivity, but most studies have been performed in research cohorts, limiting their generalizability. We studied plasma p-tau217 and p-tau181 for CSF Aβ status discrimination in a cohort of consecutive patients attending an academic memory clinic in Spain (July 2019-June 2024). All patients had CSF AD biomarkers performed as part of their routine clinical assessment.

The effect of environmental factors on transepithelial potential in a model Amazonian teleost, the tambaqui (Colossoma macropomum): Implications for sodium balance in harsh environments.

The tambaqui (Colossoma macropomum, G. Cuvier 1818) thrives both in the ion-poor waters of the Amazon and in commercial aquaculture. In both, environmental conditions can be harsh due to low ion levels, occasional high salt challenges (in aquaculture), low pH, extreme PO levels (hypoxia and hyperoxia), high PCO levels (hypercapnia), high ammonia levels (in aquaculture), and high and low temperatures.