Electrical conductivity of SiO2 at extreme conditions and planetary dynamos

Ab intio molecular dynamics simulations show that the electrical conductivity of liquid SiO2 is semimetallic at the conditions of the deep molten mantle of early Earth and super-Earths, raising the possibility of silicate dynamos in these bodies. Whereas the electrical conductivity increases uniformly with increasing temperature, it depends nonmonotonically on compression. At very high pressure, the electrical conductivity decreases on compression, opposite to the behavior of many materials. We show that this behavior is caused by a novel compression mechanism: the development of broken charge ordering, and its influence on the electronic band gap

The effects of Sepiolite-SPLF on heavy pigs fed liquid diets

The effects of the addition of Sepiolite for Pig Liquid Feeding (SPLF) at 1% on growing performance and carcass quality of heavy pigs fed practical diets were evaluated by using 330 Duroc x (Landrace x Large White) pigs, half castrated males and half females, from 63.5 to 170 kg body weight

The effects of pressed sugar beet pulp silage (PBPS) and dairy whey on heavy pig production

The effects of pressed beet pulp silage (PBPS) replacing barley for 10% and 20% (DM basis) were studied on heavy pigs (60 Hypor pigs from 28 kg) fed dairy whey-diluted diets

Synthesis of novel vanillin derivatives: novel multi-targeted scaffold ligands against Alzheimer's disease.

Alzheimer’s Disease (AD) is the most common cause of dementia worldwide, normally affecting people aged over 65. Due to the multifactorial nature of this disease, a “multi-target-directed ligands” (MTDLs) approach for the treatment of this illness has generated intense research interest in the past few years. Vanillin is a natural antioxidant and it provides a good starting point for the synthesis of new compounds with enhanced antioxidant properties, together with many biological activities, including ß-amyloid peptide aggregating and acetylcholinesterase inhibiting properties. Here we report novel vanillin derivatives, bearing a tacrine or a naphthalimido moiety. All compounds exhibited improved antioxidant properties using DPPH assay, with IC50 as low as 19.5 µM, FRAP and ORAC assays, with activities up to 1.54 and 6.4 Trolox equivalents, respectively. In addition, all compounds synthesized showed inhibitory activity toward acetylcholinesterase enzyme at µmolar concentrations using the Ellman assay. Computational docking studies of selected compounds showed interactions with both the catalytic anionic site and the peripheral anionic site of the enzyme. Furthermore, these compounds inhibited Aβ(1-42) amyloid aggregation using the fluorometric ThT assay, with compound 4 showing comparable inhibitory activity to the positive control, curcumin. At cellular level compound 4 (1 µM)showed significant protective effects of neuroblastoma SH-SY5Y cell line when treated with hydrogen peroxide (400 µM). In our opinion, vanillin derivatives could provide a viable platform for future development of multi-targeted ligands against AD

Anti-inflammatory effects of fatty acid amide hydrolase inhibition in monocytes/macrophages from alzheimer’s disease patients

Growing evidence shows that the immune system is critically involved in Alzheimer’s disease (AD) pathogenesis and progression. The modulation and targeting of peripheral immune mechanisms are thus promising therapeutic or preventive strategies for AD. Given the critical involvement of the endocannabinoid (eCB) system in modulating immune functions, we investigated the potential role of the main elements of such a system, namely type-1 and type-2 cannabinoid receptors (CB1 and CB2), and fatty acid amide hydrolase (FAAH), in distinct immune cell populations of the peripheral blood of AD patients. We found that, compared to healthy controls, CB1 and CB2 expression was significantly lower in the B-lymphocytes of AD patients. Moreover, we found that CB2 was significantly lower and FAAH was significantly higher in monocytes of the same subjects. In contrast, T-lymphocytes and NK cells did not show any variation in any of these proteins. Of note, monocytic CB2 and FAAH levels significantly correlated with clinical scores. Furthermore, the pharmacological inactivation of FAAH in monocytes and monocyte-derived macrophages obtained from AD patients was able to modulate their immune responses, by reducing production of pro-inflammatory cytokines such as TNF-α, IL-6 and IL-12, and enhancing that of the anti-inflammatory cytokine IL-10. Furthermore, FAAH blockade skewed AD monocyte-derived macrophages towards a more anti-inflammatory and pro-resolving phenotype. Collectively, our findings highlight a central role of FAAH in regulating AD monocytes/macrophages that could be of value in developing novel monocyte-centered therapeutic approaches aimed at promoting a neuroprotective environment

Exotic Statistics for Ordinary Particles in Quantum Gravity

Objects exhibiting statistics other than the familiar Bose and Fermi ones are natural in theories with topologically nontrivial objects including geons, strings, and black holes. It is argued here from several viewpoints that the statistics of ordinary particles with which we are already familiar are likely to be modified due to quantum gravity effects. In particular, such modifications are argued to be present in loop quantum gravity and in any theory which represents spacetime in a fundamentally piecewise-linear fashion. The appearance of unusual statistics may be a generic feature (such as the deformed position-momentum uncertainty relations and the appearance of a fundamental length scale) which are to be expected in any theory of quantum gravity, and which could be testable.Comment: Awarded an honourable mention in the 2008 Gravity Research Foundation Essay Competitio

Electronic conductivity of solid and liquid (Mg, Fe)O computed from first principles

Ferropericlase (Mg, Fe)O is an abundant mineral of Earth's lower mantle and the liquid phase of the material was an important component of the early magma ocean. Using quantum-mechanical, finite-temperature density-functional theory calculations, we compute the electronic component of the electrical and thermal conductivity of (Mg0.75, Fe0.25)O crystal and liquid over a wide range of planetary conditions: 0–200 GPa, 2000–4000 K for the crystal, and 0–300 GPa, 4000–10,000 K for the liquid. We find that the crystal and liquid are semi-metallic over the entire range studied: the crystal has an electrical conductivity exceeding 103 S/m, whereas that of the liquid exceeds 104 S/m. Our results on the crystal are in reasonable agreement with experimental measurements of the electrical conductivity of ferropericlase once we account for the dependence of conductivity on iron content. We find that a harzburgite-dominated mantle with ferropericlase in combination with Al-free bridgmanite agrees well with electromagnetic sounding observations, while a pyrolitic mantle with a ferric-iron rich bridgmanite composition yields a lower mantle that is too conductive. The electronic component of thermal conductivity of ferropericlase with XFe=0.19 is negligible (<1 W/m/K). The electrical conductivity of the crystal and liquid at conditions of the core-mantle boundary are similar to each other (3×104 S/m). A crystalline or liquid ferropericlase-rich layer of a few km thickness thus accounts for the high conductance that has been proposed to explain anomalies in Earth's nutation. The electrical conductivity of liquid ferropericlase exceeds that of liquid silica by more than an order of magnitude at conditions of a putative basal magma ocean, thus strengthening arguments that the basal magma ocean could have produced an ancient dynamo

Nanoscale Distribution of Nuclear Sites by Super-Resolved Image Cross-Correlation Spectroscopy

Deciphering the spatiotemporal coordination between nuclear functions is important to understand its role in the maintenance of human genome. In this context, super-resolution microscopy has gained considerable interest because it can be used to probe the spatial organization of functional sites in intact single-cell nuclei in the 20\u2013250 nm range. Among the methods that quantify colocalization from multicolor images, image cross-correlation spectroscopy (ICCS) offers several advantages, namely it does not require a presegmentation of the image into objects and can be used to detect dynamic interactions. However, the combination of ICCS with super-resolution microscopy has not been explored yet. Here, we combine dual-color stimulated emission depletion (STED) nanoscopy with ICCS (STED-ICCS) to quantify the nanoscale distribution of functional nuclear sites. We show that super-resolved ICCS provides not only a value of the colocalized fraction but also the characteristic distances associated to correlated nuclear sites. As a validation, we quantify the nanoscale spatial distribution of three different pairs of functional nuclear sites in MCF10A cells. As expected, transcription foci and a transcriptionally repressive histone marker (H3K9me3) are not correlated. Conversely, nascent DNA replication foci and the proliferating cell nuclear antigen(PCNA) protein have a high level of proximity and are correlated at a nanometer distance scale that is close to the limit of our experimental approach. Finally, transcription foci are found at a distance of 130 nm from replication foci, indicating a spatial segregation at the nanoscale. Overall, our data demonstrate that STED-ICCS can be a powerful tool for the analysis of the nanoscale distribution of functional sites in the nucleus