SK channels contribution to ventricular electrophysiology in heart failure patients

Heart failure (HF) is characterized by deterioration of the electrical and contractile function of the heart due to structural and functional remodelling, leading to development of arrhythmias and increased sudden cardiac death risk. SK channels are a type of calcium-activated potassium channels that do not play a relevant role in normal ventricular electrophysiology. However, it has been hypothesized that these channels become more relevant in pathologies such as HF. Nontheless, their role in human ventricular electrophysiology is not fully characterized

Efficiency of European public higher education institutions: a two-stage multicountry approach

The purpose of this study is to examine efficiency and its determinants in a set of higher education institutions (HEIs) from several European countries by means of non-parametric frontier techniques. Our analysis is based on a sample of 259 public HEIs from 7 European countries across the time period of 2001–2005. We conduct a two-stage DEA analysis (Simar and Wilson in J Economet 136:31–64, 2007), first evaluating DEA scores and then regressing them on potential covariates with the use of a bootstrapped truncated regression. Results indicate a considerable variability of efficiency scores within and between countries. Unit size (economies of scale), number and composition of faculties, sources of funding and gender staff composition are found to be among the crucial determinants of these units’ performance. Specifically, we found evidence that a higher share of funds from external sources and a higher number of women among academic staff improve the efficiency of the institution

Insect occurrence and losses due to phytophagous species in the amaranth Amaranthus hypocondriacus L. crop in Puebla, Mexico,

A field survey for insects associated with amaranth Amaranthus hypocondriacus L. (Amaranthaceae) was conducted in the semiarid Region Mixteca of Puebla State in Mexico. Also, the losses to the crop caused by the phytophagous species were assessed. Samples were collected every fifteen days during one year in five plots to obtain a representation of the phytophagous and beneficial insects, and of the percentages of plants infested with the principal phytophagous insects. The species that were observed causing considerable damage to the crop were Hypolixus truncatulus Fab. (Coleoptera: Curculionidae), Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), Pholisora catullus (Fab.) (Lepidoptera: Hesperiidae) and Phyllophaga ilhuicaminai Morón (Coleoptera: Melolonthidae). Borers infested 92% of the crop, while the white grubs group 45%. Yield losses by general insects without pest control program were 65.5%. Foliage and soil insects reduced the yield to 44.2 and 39.1%, respectively. This is the first report of quantification of losses due to pest insects in the amaranth crop.the Institution Alternativas y Procesos de Participación Social A.C. for the economic support given in the realization of the work; and to Eugenio Morales, and Avellino Ruiz for the support received during the field work.Peer Reviewe

Minimally invasive system to reliably characterize ventricular electrophysiology from living donors

Cardiac tissue slices preserve the heterogeneous structure and multicellularity of the myocardium and allow its functional characterization. However, access to human ventricular samples is scarce. We aim to demonstrate that slices from small transmural core biopsies collected from living donors during routine cardiac surgery preserve structural and functional properties of larger myocardial specimens, allowing accurate electrophysiological characterization. In pigs, we compared left ventricular transmural core biopsies with transmural tissue blocks from the same ventricular region. In humans, we analyzed transmural biopsies and papillary muscles from living donors. All tissues were vibratome-sliced. By histological analysis of the transmural biopsies, we showed that tissue architecture and cellular organization were preserved. Enzymatic and vital staining methods verified viability. Optically mapped transmembrane potentials confirmed that action potential duration and morphology were similar in pig biopsies and tissue blocks. Action potential morphology and duration in human biopsies and papillary muscles agreed with published ranges. In both pigs and humans, responses to increasing pacing frequencies and ß-adrenergic stimulation were similar in transmural biopsies and larger tissues. We show that it is possible to successfully collect and characterize tissue slices from human myocardial biopsies routinely extracted from living donors, whose behavior mimics that of larger myocardial preparations both structurally and electrophysiologically