Assessment of “Carbopeaking” in a hydropeaking-impacted river in the Italian Alpine area

Hydropeaking (i.e., rapid and frequent artificial flow fluctuations caused by reservoir-operated hydropower production) is a much-investigated river stressor, and has been associated, among others, to sudden changes in temperature (“thermopeaking”), underwater soundscape (“soundpeaking”), total dissolved gas saturation (“saturopeaking”). We have recently started investigating the “carbopeaking”, i.e., variations of greenhouse gas (mainly CO2) concentrations and evasion fluxes through the water-air interface associated with hydropeaks. Here we report on the methodology and preliminary results from a field-measurement campaign conducted in a single-thread Alpine river (River Noce, Italy) during multiple hydropeaking events. The analysis of water samples collected in the upstream reservoir showed CO2 oversaturation in the hypolimnion, around the depth of the hydropower intake system. In the Noce reach upstream of the hydropower plant outlet (i.e., in a residual flow stretch), the CO2 concentrations displayed diel fluctuations around the atmospheric equilibrium concentration, likely driven by diurnal primary production. Conversely, water released at the hydropower outlet during hydropeaking were consistently oversaturated in CO2 relative to the atmosphere, in agreement with the concentrations in the reservoir’s hypolimnetic water. As a result, hydropeaking events were associated with an alteration of the sub-daily patterns of CO2 concentration downstream of the hydropower outlet which, combined with higher gas exchange velocities occurring during higher flow rates, can cause periods of enhanced CO2 emissions. The results highlight the potential impact of hydropeaking on greenhouse gas emissions, demonstrating the need to account for sub-daily variations of flow and gas concentration to accurately quantify carbon balances in rivers impacted by hydropower

Mitochondria matter: Systemic aspects of nonalcoholic fatty liver disease (nafld) and diagnostic assessment of liver function by stable isotope dynamic breath tests

The liver plays a key role in systemic metabolic processes, which include detoxification, synthesis, storage, and export of carbohydrates, lipids, and proteins. The raising trends of obesity and metabolic disorders worldwide is often associated with the nonalcoholic fatty liver disease (NAFLD), which has become the most frequent type of chronic liver disorder with risk of progression to cirrhosis and hepatocellular carcinoma. Liver mitochondria play a key role in degrading the pathways of carbohydrates, proteins, lipids, and xenobiotics, and to provide energy for the body cells. The morphological and functional integrity of mitochondria guarantee the proper functioning of β‐oxidation of free fatty acids and of the tricarboxylic acid cycle. Evaluation of the liver in clinical medicine needs to be accurate in NAFLD patients and includes history, physical exam, imaging, and laboratory assays. Evaluation of mitochondrial function in chronic liver disease and NAFLD is now possible by novel diagnostic tools. “Dynamic” liver function tests include the breath test (BT) based on the use of substrates marked with the non‐radioactive, naturally occurring stable isotope13C. Hepatocellular metabolization of the substrate will generate13CO2, which is excreted in breath and measured by mass spectrometry or infrared spectroscopy. Breath levels of 13 CO2 are biomarkers of specific metabolic processes occurring in the hepatocyte cytosol, microsomes, and mitochondria.13 C‐BTs explore distinct chronic liver diseases including simple liver steatosis, non‐alcoholic steatohepatitis, liver fibrosis, cirrhosis, hepatocellular carcinoma, drug, and alcohol effects. In NAFLD,13C‐BT use substrates such as α‐ketoisocaproic acid, methionine, and octanoic acid to assess mitochondrial oxidation capacity which can be impaired at an early stage of disease.13C‐BTs represent an indirect, cost‐effective, and easy method to evaluate dynamic liver function. Further applications are expected in clinical medicine. In this review, we discuss the involvement of liver mitochondria in the progression of NAFLD, together with the role of13C‐BT in assessing mitochondrial function and its potential use in the prevention and management of NAFLD

Towards specific T–H relationships: FRIBAS database for better characterization of RC and URM buildings

FRIBAS database is an open access database composed of the characteristics of 312 buildings (71 masonry, 237 reinforced concrete and 4 mixed types). It collects and harmonizes data from different surveys performed on buildings in the Basilicata and Friuli Venezia Giulia regions (Southern and Northeastern Italy, respectively). Each building is defined by 37 parameters related to the building and foundation soil characteristics. The building and soil fundamental periods were experimentally estimated based on ambient noise measurements. FRIBAS gave us the opportunity to study the influence of the main characteristics of buildings and the soil-building interaction effect to their structural response. In this study, we have used the FRIBAS dataset to investigate how the building period varies as a function of construction materials and soil types. Our results motivate the need of going beyond a 'one-fits-all' numerical period-height (T-H) relationship for generic building typologies provided by seismic codes, towards specific T-H relationships that account for both soil and building typologies

Translating the Game: Ribosomes as Active Players

Ribosomes have been long considered as executors of the translational program. The fact that ribosomes can control the translation of specific mRNAs or entire cellular programs is often neglected. Ribosomopathies, inherited diseases with mutations in ribosomal factors, show tissue specific defects and cancer predisposition. Studies of ribosomopathies have paved the way to the concept that ribosomes may control translation of specific mRNAs. Studies in Drosophila and mice support the existence of heterogeneous ribosomes that differentially translate mRNAs to coordinate cellular programs. Recent studies have now shown that ribosomal activity is not only a critical regulator of growth but also of metabolism. For instance, glycolysis and mitochondrial function have been found to be affected by ribosomal availability. Also, ATP levels drop in models of ribosomopathies. We discuss findings highlighting the relevance of ribosome heterogeneity in physiological and pathological conditions, as well as the possibility that in rate-limiting situations, ribosomes may favor some translational programs. We discuss the effects of ribosome heterogeneity on cellular metabolism, tumorigenesis and aging. We speculate a scenario in which ribosomes are not only executors of a metabolic program but act as modulators

Glycerol and testicular activity: the good, the bad and the ugly

Over the past decades, there have been several studies suggesting that semen quality is declining. Interestingly, these observations are paired with a significant increase in the number of individuals diagnosed with metabolic diseases, including obesity and diabetes mellitus. Hence, it is tempting to hypothesize that obesity and its associated comorbidities and risk factors (such as a hypercaloric diets) impair the homeostasis of the male reproductive health, with a possible direct effect on the testes. The blood and interstitial fluids of obese individuals usually have increased levels of glycerol, notably due to triglyceride and phospholipid catabolism and high fructose intake. Glycerol is metabolized via intermediary metabolism by a group of reactions centred at the glycerol-3-phosphate shuttle, which links the metabolic pathway of glucose, lipids and oxidative phosphorylation, illustrating its high relevance for biological systems. Glycerol enters and exits the cells by the action of specialized carriers, known as aquaglyceroporins, whose functional importance for male reproductive health has emerged in the last few years. Notably, glycerol has antispermatogenic properties. When present in high concentration in the testis, it causes blood-testis barrier disruption, impairing tubular fluid homeostasis. Nevertheless, glycerol metabolism in testicular cells remains a matter of debate. Herein we discuss previous and current research concerning the role of glycerol and its metabolism in testicular cells, and how it can influence testicular activity

Exposure to Plasma From Non-alcoholic Fatty Liver Disease Patients Affects Hepatocyte Viability, Generates Mitochondrial Dysfunction, and Modulates Pathways Involved in Fat Accumulation and Inflammation

Changes of lipidic storage, oxidative stress and mitochondrial dysfunction may be involved in the pathogenesis of non-alcoholic fatty liver disease (NAFLD). Although the knowledge of intracellular pathways has vastly expanded in recent years, the role and mechanisms of circulating triggering factor(s) are debated. Thus, we tested the hypothesis that factors circulating in the blood of NAFLD patients may influence processes underlying the disease. Huh7.5 cells/primary human hepatocytes were exposed to plasma from 12 NAFLD patients and 12 healthy subjects and specific assays were performed to examine viability, H2O2 and mitochondrial reactive oxygen species (ROS) release, mitochondrial membrane potential and triglycerides content. The involvement of NLRP3 inflammasome and of signaling related to peroxisome-proliferator-activating-ligand-receptor-γ (PPARγ), sterol-regulatory-element-binding-protein-1c (SREBP-1c), nuclear-factor-kappa-light-chain-enhancer of activated B cells (NF-kB), and NADPH oxidase 2 (NOX2) was evaluated by repeating the experiments in the presence of NLRP3 inflammasome blocker, MCC950, and through Western blot. The results obtained shown that plasma of NAFLD patients was able to reduce cell viability and mitochondrial membrane potential by about 48 and 24% (p < 0.05), and to increase H2O2, mitochondrial ROS, and triglycerides content by about 42, 19, and 16% (p < 0.05), respectively. An increased expression of SREBP-1c, PPARγ, NF-kB and NOX2 of about 51, 121, 63, and 46%, respectively, was observed (p < 0.05), as well. Those effects were reduced by the use of MCC950. Thus, in hepatocytes, exposure to plasma from NAFLD patients induces a NAFLD-like phenotype by interference with NLRP3-inflammasome pathways and the activation of intracellular signaling related to SREBP-1c, PPARγ, NF-kB and NOX2

Finding aquaporins in annelids: An evolutionary analysis and a case study

Aquaporins (AQPs) are a family of membrane channels facilitating diffusion of water and small solutes into and out of cells. Despite their biological relevance in osmoregulation and ubiquitous distribution throughout metazoans, the presence of AQPs in annelids has been poorly investigated. Here, we searched and annotated Aqp sequences in public genomes and transcriptomes of annelids, inferred their evolutionary relationships through phylogenetic analyses and discussed their putative physiological relevance. We identified a total of 401 Aqp sequences in 27 annelid species, including 367 sequences previously unrecognized as Aqps. Similar to vertebrates, phylogenetic tree reconstructions clustered these annelid Aqps in four clades: AQP1-like, AQP3-like, AQP8-like and AQP11-like. We found no clear indication of the existence of paralogs exclusive to annelids; however, several gene duplications seem to have occurred in the ancestors of some Sedentaria annelid families, mainly in the AQP1-like clade. Three of the six Aqps annotated in Alitta succinea, an estuarine annelid showing high salinity tolerance, were validated by RT-PCR sequencing, and their similarity to human AQPs was investigated at the level of “key” conserved residues and predicted three-dimensional structure. Our results suggest a diversification of the structures and functions of AQPs in Annelida comparable to that observed in other taxa

Resting energy expenditure is not altered in children and adolescents with obesity. Effect of age and gender and association with serum Leptin levels

In children and adolescents, obesity does not seem to depend on a reduction of resting energy expenditure (REE). Moreover, in this young population, the interactions between either age and obesity or between age and gender, or the role of leptin on REE are not clearly understood. To compare the levels of REE in children and adolescents we studied 181 Caucasian individuals (62% girls) classified on the basis of age-and sex-specific body mass index (BMI) percentile as healthy weight (n = 50), with overweight (n = 34), or with obesity (n = 97) and in different age groups: 8–10 (n = 38), 11–13 (n = 50), and 14–17 years (n = 93). REE was measured by indirect calorimetry and body composition by air displacement plethysmography. Statistically significant differences in REE/fat-free mass (FFM) regarding obesity or gender were not observed. Absolute REE increases with age (p < 0.001), but REE/FFM decreases (p < 0.001) and there is an interaction between gender and age (p < 0.001) on absolute REE showing that the age-related increase is more marked in boys than in girls, in line with a higher FFM. Interestingly, the effect of obesity on absolute REE is not observed in the 8–10 year-old group, in which serum leptin concentrations correlate with the REE/FFM (r = 0.48; p = 0.011). In conclusion, REE/FFM is not affected by obesity or gender, while the effect of age on absolute REE is gender-dependent and leptin may influence the REE/FFM in 8–10 year-olds