Dynamic chromatin association of IκBα is regulated by acetylation and cleavage of histone H4

Nuclear IκBα preferentially binds the acetylated N‐terminal tail of histone H4 in vivo, specifically in the skin and intestine stem cell compartments. N‐terminal cleavage of histone H4 facilitates IκBα dissociation and cellular differentiation.     

Dietary antioxidants interfere with Amplex Red-coupled-fluorescence assays

Oxidation of Amplex Red by hydrogen peroxide in the presence of horseradish peroxidase (HRP) gives rise to an intensely colour product, resorufin. This reaction has been frequently employed for measurements based on enzyme-coupled reactions that detect hydrogen peroxide as a final reaction product. In the current study, we show that the presence of dietary antioxidants at biological concentrations in the reaction medium produced interferences in the Amplex Red/HRP catalyzed reaction that result in an over quantification of the hydrogen peroxide produced. The interference observed showed a dose-dependent manner, and a possible mechanism of interaction of dietary antioxidants with HRP in the Amplex Red-coupled-fluorescent assay is proposed.     

Buccal dental microwear variability in extant African Hominoidea: taxonomy versus ecology

Buccal microwear patterns on teeth are good indicators of the abrasiveness of foodstuffs and have been used to trace the dietary habits of fossil species, including primates and hominids. However, few studies have addressed the variability of this microwear. The abrasiveness of dietary components depends not only on the hardness of the particles ingested, but also on the presence of dust and other exogenous elements introduced during food processing. These elements are responsible for the microwear typology observed on the enamel surfaces of primate teeth. Here we analyzed the variability of buccal microwear patterns in African Great Apes (Gorilla gorilla and Pan troglodytes), using tooth molds obtained from the original specimens held in several osteological collections. Our results suggest that ecological adaptations at subspecies or population level account for differences in microwear patterns, which are attributed to habitat and ecological conditions within populations rather than differences between species. The findings from studies on the variability of buccal dental microwear in extant species will contribute to a better understanding of extinct hominids’ diet and ecology.     

Patterns of genetic diversity and linkage disequilibrium in a highly structured Hordeum vulgare association-mapping population for the Mediterranean basin

Population structure and genome-wide linkage disequilibrium (LD) were investigated in 192 Hordeum vulgare accessions providing a comprehensive coverage of past and present barley breeding in the Mediterranean basin, using 50 nuclear microsatellite and 1,130 DArT^® markers. Both clustering and principal coordinate analyses clearly sub-divided the sample into five distinct groups centred on key ancestors and regions of origin of the germplasm. For given genetic distances, large variation in LD values was observed, ranging from closely linked markers completely at equilibrium to marker pairs at 50 cM separation still showing significant LD. Mean LD values across the whole population sample decayed below r ² of 0.15 after 3.2 cM. By assaying 1,130 genome-wide DArT^® markers, we demonstrated that, after accounting for population substructure, current genome coverage of 1 marker per 1.5 cM except for chromosome 4H with 1 marker per 3.62 cM is sufficient for whole genome association scans. We show, by identifying associations with powdery mildew that map in genomic regions known to have resistance loci, that associations can be detected in strongly stratified samples provided population structure is effectively controlled in the analysis. The population we describe is, therefore, shown to be a valuable resource, which can be used in basic and applied research in barley.     

The bioeroded megasurface of Oura (Algarve,south Portugal): implications for the Neogene stratigraphy and tectonic evolution of southwest Iberia

The use of rocky palaeoshore bioerosion analysis as a tool to solve stratigraphic and tectonic issues is beginning to bear fruits. The occurrence of an extensive intra-Miocene marine abrasion platform in southern Portugal at Oura (Albufeira) has been identified on the basis of bioerosion trace fossils analysis. The observed ichnodiversity is rather low, with bivalve boring Gastrochaenolites being dominant. Nevertheless, the ichnoassemblage may be assigned to the Entobia ichnofacies. The palaeoichnological study of the Oura hardground confirmed the existence of an important intra-Miocene stratigraphic gap (ca. 3 Ma hiatus), represented by a razor-sharp erosional contact that separates the two main Neogene units in the Algarvian region: the lower carbonate sequence of Lagos–Portimão Formation (Langhian/Serravallian) and the upper siliciclastic sequence of the Cacela Formation (Upper Tortonian).     

Compartments in a marine food web associated with phylogeny, body mass, and habitat structure

A long-standing question in community ecology is whether food webs are organized in compartments, where species within the same compartment interact frequently among themselves, but show fewer interactions with species from other compartments. Finding evidence for this community organization is important since compartmentalization may strongly affect food web robustness to perturbation. However, few studies have found unequivocal evidence of compartments, and none has quantified the suite of mechanisms generating such a structure. Here, we combine computational tools from the physics of complex networks with phylogenetic statistical methods to show that a large marine food web is organized in compartments, and that body size, phylogeny, and spatial structure are jointly associated with such a compartmentalized structure. Sharks account for the majority of predatory interactions within their compartments. Phylogenetically closely related shark species tend to occupy different compartments and have divergent trophic levels, suggesting that competition may play an important role structuring some of these compartments. Current overfishing of sharks has the potential to change the structural properties, which might eventually affect the stability of the food web.     

Hepatic monocyte chemoattractant protein-1 is upregulated by dietary cholesterol and contributes to liver steatosis

To assess the role of monocyte chemoattractant protein-1 (MCP-1/CCL2) in the development of fatty liver, we have used LDLr^−/− mice as an animal model of high-fat, high-cholesterol diet-induced liver steatosis. The rapid dietary induction of hepatic mRNA MCP-1 expression was paralleled by a concomitant increase in plasma MCP-1 that was strongly associated with the degree of liver steatosis. Hepatocytes showed an intense immunoreactivity for MCP-1 that was mainly located surrounding the hepatic lipid droplets. The intake of cholesterol also increased the concentration of MCP-1 in liver homogenates. This was accompanied by a differential expression of members of the PPAR family. Additionally, complete MCP-1 deficiency prevents the development of liver steatosis in LDLr^−/− mice and partial deficiency is accompanied by a certain protective effect. Our data also suggest that MCP-1 may be important in the regulation of hepatic insulin resistance and may represent a link between inflammation and metabolic diseases. We conclude that dietary cholesterol upregulation of hepatic MCP-1 may help to understand the role of circulating MCP-1 in conditions where liver derangements are clinically important and in the association of liver steatosis with the metabolic syndrome.     

A clinical registry of dementia based on the principle of epidemiological surveillance

Background  

Traditional epidemiological studies do not allow elucidating the reality of referral and diagnosis patterns of dementia in routine clinical practice within a defined territory. This information is useful and necessary in order to plan and allocate healthcare resources. This paper presents the results from a dementia case registry based on epidemiological surveillance fundamentals.