Effects of training on axial muscle of two cyprinid species: Chondrostoma nasus (L.) and Leuciscus cephalus (L.)

The effect of an endurance training program lasting 17 weeks was studied in two cyprinid species, Chondrostoma nasus (L.) and Leuciscus cephalus (L.). Red, intermediate and white axial muscle were investigated. Morphometrical analysis revealed that training induced, in both species, increased red and intermediate muscle mass, fibre diameter and capillarization. Differences between species in the response to training were observed for volume densities of mitochondria and lipid. In contrast to C. nasus, L. cephalus show higher values for these compartments in red and intermediate fibres. The results are considered adaptational changes which increase the aerobic capacity of red and intermediate muscle fibres to meet higher sustained swimming activities.     

Lectin-Binding Sites Involved in Paramecium primaurelia Mating Pair Formation

ABSTRACT. Mating pair formation in Paramecium primaurelia was shown to be inhibited by incubating mating-competent mating type (mt) I and mt U cells with Limulus polyphemus agglutinin (LPA) or wheat germ agglutinin (WGA). Preincubation of LPA and WGA with their specific binding-monosaccharides, N-acetylneuraminic acid (NeuAc) and N-acetylglucosamine (GlcNAc), respectively, prevented the lectin effect on pair formation. Addition either of NeuAc or GlcNAc resulted in a reversal of cell pairing inhibition by LPA or WGA, respectively. Both NeuAc and GlcNAc monosaccharides inhibited pair formation when their concentration exceeded a threshold value. The pattern of the relative distribution of NeuAc and GlcNAc molecules on the cell surface was analyzed using fluorescence resonance energy transfer techniques combined with imaging systems. Mt I1 cells showed a high lectin-binding site density localized just on the surface region engaged in conjugation. The pattern of mt I cells, consisting of a quite homogeneous lectin-binding site density spread on the cell surface, was also common to nonmating-competent cells and to immature cells. These findings suggest that in P. primaurelia pair formation involves both NeuAc and GlcNAc residues and that the development of mating-competence is related to a modification in NeuAc and GlcNAc relative distribution on the cell surface of mt 11 cells.     

An application case of ecological indicator values (Zeigerwerte) calculated with a simple algorithmic approach

Abstract

The vegetation of the study site near Rome (Castelporziano Estate), where different woodland types occur, was analysed on the basis of ecological indicator values (Zeigerwerte) for light, temperature, continentality of climate, soil moisture, soil pH and nitrogen. Indicator values were estimated with Hill's reprediction algorithm for the flora of Central-Southern Italy relying on a database of 4,207 original relevés representing a balanced survey of the vegetation of this and surrounding areas. It was possible to obtain indicator values for an important fraction of the Italian Mediterranean flora. Results are ecologically reasonable, and it was possible to find strong correlation between the recalculated values and a few environmental variables. These correlations were not significant in an analogous test with subjectively derived scores of Ellenberg indicator values.     

Changes in vegetation patterns on the margins of a constructed wetland after 10 years

Summary A constructed urban wetland in Adelaide was surveyed 18 months and 10 years after construction to see how shoreline vegetation, soil electrical conductivity (EC), texture and pH changed over time and to provide data for future site management. Multivariate analysis detected four plant associations at 18 months: salt‐tolerant taxa on conductive clays; a weed‐dominated community on lower EC soil; and two smaller waterlogged, low EC clusters dominated by Common Reed (Phragmites australis) and Sea Club‐Rush (Bolboschoenus caldwellii), respectively. At 10 years, site cover and heterogeneity was higher, with the margins dominated by Phragmites and salt‐tolerant species. EC was much lower and more uniform, and the soils were heavier and more alkaline. Managed storm water flushing apparently lowered soil EC, but possibly also disturbed the shoreline. However, weeds were still common, and the potential for domination by Phragmites at the expense of other native shoreline species means that ongoing monitoring and hydrological and vegetation management are essential to maintain site habitat diversity.     

What Are the Health Risks of Eating Red Meat,and How Should We Assess Them?

This paper discusses possible mechanisms that might lead to misinterpretations of collected data and makes new evidence-based medicine (EBM) recommendations to oppose the previously accepted preventive measures, or treatment options. It is focused on the danger of the “red meat” consumption, and the question whether eating pungent food is good or bad for our health and finally whether the “bad luck” concept of getting several cancer types is valid or not. These three topics got and still have significant media attention. Several mechanisms are proposed as possible causes of these apparent conflicts. Some of them have already been recognized but sadly remained less known to medical readers and also to the general population. Also see the video abstract here https://youtu.be/owjoRXrNShA .     

Promises of Main Group Metal–Based Nanostructured Materials for Electrochemical CO2 Reduction to Formate

Selective CO₂ reduction to formic acid or formate is the most technologically and economically viable approach to realize electrochemical CO₂ valorization. Main group metal–based (Sn, Bi, In, Pb, and Sb) nanostructured materials hold great promise, but are still confronted with several challenges. Here, the current status, challenges, and future opportunities of main group metal–based nanostructured materials for electrochemical CO₂ reduction to formate are reviewed. Firstly, the fundamentals of electrochemical CO₂ reduction are presented, including the technoeconomic viability of different products, possible reaction pathways, standard experimental procedure, and performance figures of merit. This is then followed by detailed discussions about different types of main group metal–based electrocatalyst materials, with an emphasis on underlying material design principles for promoting the reaction activity, selectivity, and stability. Subsequently, recent efforts on flow cells and membrane electrode assembly cells are reviewed so as to promote the current density as well as mechanistic studies using in situ characterization techniques. To conclude a short perspective is offered about the future opportunities and directions of this exciting field.     

Monitoring tropical forests under a functional perspective with satellite‐based vegetation optical depth

Monitoring ecosystem functions in forests is a priority in a climate change scenario, as climate‐induced events may initially alter the functions more than slow‐changing attributes, such as biomass. The ecosystem functional properties (EFPs) are quantities that characterize key ecosystem processes. They can be derived by point observations of gas and energy exchanges between the ecosystems and the atmosphere that are collected globally at FLUXNET flux tower sites and upscaled at ecosystem level. The properties here considered describe the ability of ecosystems to optimize the use of resources for carbon uptake. They represent functional forest information, are dependent on environmental drivers, linked to leaf traits and forest structure, and influenced by climate change effects. The ability of vegetation optical depth (VOD) to provide forest functional information is investigated using 2011–2014 satellite data collected by the Soil Moisture and Ocean Salinity mission and using the EFPs as reference dataset. Tropical forests in Africa and South America were analyzed, also according to ecological homogeneous units. VOD jointly with water deficit information explained 93% and 87% of the yearly variability in both flux upscaled maximum gross primary productivity and light use efficiency functional properties, in Africa and South America forests respectively. Maps of the retrieved properties evidenced changes in forest functional responses linked to anomalous climate‐induced events during the study period. The findings indicate that VOD can support the flux upscaling process in the tropical range, affected by high uncertainty, and the detection of forest anomalous functional responses. Preliminary temporal analysis of VOD and EFP signals showed fine‐grained variability in periodicity, in signal dephasing, and in the strength of the relationships. In selected drier forest types, these satellite data could also support the monitoring of functional dynamics.     

Plant carbon allocation drives turnover of old soil organic matter in permafrost tundra soils

Carbon cycle feedbacks from permafrost ecosystems are expected to accelerate global climate change. Shifts in vegetation productivity and composition in permafrost regions could influence soil organic carbon (SOC) turnover rates via rhizosphere (root zone) priming effects (RPEs), but these processes are not currently accounted for in model predictions. We use a radiocarbon (bomb‐¹⁴C) approach to test for RPEs in two Arctic tall shrubs, alder (Alnus viridis (Chaix) DC.) and birch (Betula glandulosa Michx.), and in ericaceous heath tundra vegetation. We compare surface CO₂ efflux rates and ¹⁴C content between intact vegetation and plots in which below‐ground allocation of recent photosynthate was prevented by trenching and removal of above‐ground biomass. We show, for the first time, that recent photosynthate drives mineralization of older (>50 years old) SOC under birch shrubs and ericaceous heath tundra. By contrast, we find no evidence of RPEs in soils under alder. This is the first direct evidence from permafrost systems that vegetation influences SOC turnover through below‐ground C allocation. The vulnerability of SOC to decomposition in permafrost systems may therefore be directly linked to vegetation change, such that expansion of birch shrubs across the Arctic could increase decomposition of older SOC. Our results suggest that carbon cycle models that do not include RPEs risk underestimating the carbon cycle feedbacks associated with changing conditions in tundra regions.