University of Córdoba (Spain)

About: University of Córdoba (Spain) is a education organization based out in Cordova, Spain. It is known for research contribution in the topics: Population & Catalysis. The organization has 12006 authors who have published 22998 publications receiving 537842 citations. The organization is also known as: University of Córdoba (Spain) & Universidad de Córdoba.

Ephemeral gully erosion in southern Navarra (Spain)

Abstract: Ephemeral gully erosion is a common type of water erosion in the loamy soils formed on the Miocene Marls of southern Navarra. A study has been conducted to describe the different types of ephemeral gullies and to determine their origin, evolution and importance as sediment sources. Three main types were identified according to their origin: classic ephemeral gullies formed within the same field where runoff starts, drainage ephemeral gullies collecting the runoff from another upstream area, and discontinuity ephemeral gullies due to some abrupt slope change in the landscape. During 2 consecutive years of normal precipitation, ephemeral gully erosion has caused significant soil losses, locally over 2.66 kg m−2 yr−1, which is above tolerable levels. In each year, one short and intense rainfall event has been responsible for almost all soil losses from ephemeral gullies. The main cause of gully formation is the lack of any proper waterway for conveying water excess. Conventional tillage practices provoked gully occurrence, while the maintenance of stubble or vegetation cover completely prevented their formation. Although farmers refill gullies every year, they reappear at the same position if no preventive measures are taken. Early winter has been the most critical period for gully formation, when the soil is wetter and the surface cover is scarce. But a strong summer thunderstorm also caused severe gully erosion in unprotected soils. Two simple topographic indices based on the area and the slope of the watersheds are useful to describe total soil losses.

Mechanisms Underlying Caloric Restriction and Lifespan Regulation Implications for Vascular Aging

Abstract: This review focuses on the emerging evidence that attenuation of the production of reactive oxygen species and inhibition of inflammatory pathways play a central role in the antiaging cardiovascular effects of caloric restriction. Particular emphasis is placed on the potential role of the plasma membrane redox system in caloric restriction-induced pathways responsible for sensing oxidative stress and increasing cellular oxidative stress resistance. We propose that caloric restriction increases bioavailability of NO, decreases vascular reactive oxygen species generation, activates the Nrf2/antioxidant response element pathway, inducing reactive oxygen species detoxification systems, exerts antiinflammatory effects, and, thereby, suppresses initiation/progression of vascular disease that accompany aging.

Crystallinity Control of a Nanostructured LiNi0.5Mn1.5O4 Spinel via Polymer-Assisted Synthesis: A Method for Improving Its Rate Capability and Performance in 5 V Lithium Batteries†

Abstract: Li–Ni–Mn spinels of nominal composition LiNi05Mn15O4, which are functional materials for electrodes in high-voltage lithium batteries, are prepared by thermal decomposition of mixed nanocrystalline oxalates obtained by grinding hydrated salts and oxalic acid in the presence of polyethyleneglycol 400 Their structure, microstructure, and texture are established from combined X-ray photoelectron spectroscopy (XPS), X-ray diffraction, transmission electron microscopy (TEM), IR spectroscopy, and N2 absorption measurements The polymer tailors the shape of particles, which adopt a nanorodlike morphology at low temperatures (400 °C) In fact, the nanorods consist of highly distorted oriented nanocrystals connected by a polymer-based film as inferred from IR and XPS spectra The electrochemical properties of spinels in this peculiar form are quite poor, mainly as a result of the high microstrain content of their nanocrystals Raising the temperature up to 800 °C partially destroys the nanorods, which become highly crystalline nanoparticles approximately 80 nm in size At this temperature, the polymer facilitates crystal growth; this leads to highly crystalline polyhedral nanoparticles as revealed from TEM images and microstrain data Following functionalization as a cathode in lithium cells, this material exhibits a very good rate capability, coulombic efficiency, and capacity retention even upon cycling at voltages as high as 5 V Moreover, it withstands fast-charge–slow-discharge processes, which is an important cycle-life-related property for commercial batteries

Changes in biocrust cover drive carbon cycle responses to climate change in drylands

Abstract: Dryland ecosystems account for ca. 27% of global soil organic carbon (C) reserves, yet it is largely unknown how cli- mate change will impact C cycling and storage in these areas. In drylands, soil C concentrates at the surface, making it particularly sensitive to the activity of organisms inhabiting the soil uppermost levels, such as communities domi- nated by lichens, mosses, bacteria and fungi (biocrusts). We conducted a full factorial warming and rainfall exclusion experiment at two semiarid sites in Spain to show how an average increase of air temperature of 2-3 °C promoted a drastic reduction in biocrust cover (ca. 44% in 4 years). Warming significantly increased soil CO2 efflux, and reduced soil net CO2 uptake, in biocrust-dominated microsites. Losses of biocrust cover with warming through time were par- alleled by increases in recalcitrant C sources, such as aromatic compounds, and in the abundance of fungi relative to bacteria. The dramatic reduction in biocrust cover with warming will lessen the capacity of drylands to sequester atmospheric CO2. This decrease may act synergistically with other warming-induced effects, such as the increase in soil CO2 efflux and the changes in microbial communities to alter C cycling in drylands, and to reduce soil C stocks in the mid to long term.

Monounsaturated Fatty Acid–Enriched High-Fat Diets Impede Adipose NLRP3 Inflammasome–Mediated IL-1β Secretion and Insulin Resistance Despite Obesity

Abstract: Saturated fatty acid (SFA) high-fat diets (HFDs) enhance interleukin (IL)-1β-mediated adipose inflammation and insulin resistance. However, the mechanisms by which different fatty acids regulate IL-1β and the subsequent effects on adipose tissue biology and insulin sensitivity in vivo remain elusive. We hypothesized that the replacement of SFA for monounsaturated fatty acid (MUFA) in HFDs would reduce pro-IL-1β priming in adipose tissue and attenuate insulin resistance via MUFA-driven AMPK activation. MUFA-HFD-fed mice displayed improved insulin sensitivity coincident with reduced pro-IL-1β priming, attenuated adipose IL-1β secretion, and sustained adipose AMPK activation compared with SFA-HFD-fed mice. Furthermore, MUFA-HFD-fed mice displayed hyperplastic adipose tissue, with enhanced adipogenic potential of the stromal vascular fraction and improved insulin sensitivity. In vitro, we demonstrated that the MUFA oleic acid can impede ATP-induced IL-1β secretion from lipopolysaccharide- and SFA-primed cells in an AMPK-dependent manner. Conversely, in a regression study, switching from SFA- to MUFA-HFD failed to reverse insulin resistance but improved fasting plasma insulin levels. In humans, high-SFA consumers, but not high-MUFA consumers, displayed reduced insulin sensitivity with elevated pycard-1 and caspase-1 expression in adipose tissue. These novel findings suggest that dietary MUFA can attenuate IL-1β-mediated insulin resistance and adipose dysfunction despite obesity via the preservation of AMPK activity.