Dietary Nanoparticles Interact with Gluten Peptides and Alter the Intestinal Homeostasis Increasing the Risk of Celiac Disease

The introduction of metallic nanoparticles (mNPs) into the diet is a matter of concern for human health. In particular, their effect on the gastrointestinal tract may potentially lead to the increased passage of gluten peptides and the activation of the immune response. In consequence, dietary mNPs could play a role in the increasing worldwide celiac disease (CeD) incidence. We evaluated the potential synergistic effects that peptic-tryptic-digested gliadin (PT) and the most-used food mNPs may induce on the intestinal mucosa. PT interaction with mNPs and their consequent aggregation was detected by transmission electron microscopy (TEM) analyses and UV–Vis spectra. In vitro experiments on Caco-2 cells proved the synergistic cytotoxic effect of PT and mNPs, as well as alterations in the monolayer integrity and tight junction proteins. Exposure of duodenal biopsies to gliadin plus mNPs triggered cytokine production, but only in CeD biopsies. These results suggest that mNPs used in the food sector may alter intestinal homeostasis, thus representing an additional environmental risk factor for the development of CeD.     

Synaptic view of eukaryotic cell

Synapses are stable adhesive domains between two neighbouring cells of the multicellular organisms which serve for cell–cell communication as well as for information processing and storing. The synaptic concept was developed over more than 100 years specifically for neuronal cell–cell communication. In the last ten years, this concept was adapted to embrace other cell–cell communication phenomena. Here, we focus on the recently emerged phagocytic synapse and propose new endosymbiotic synapses and “intracellular organellar synapses”. All these synapses of eukaryotic cells are in a good position to explain the high capacity of eukaryotic cells for integration of diverse signalling inputs into coherent cellular behaviour.     

Control theoretic optimization of 802.11 WLANs: Implementation and experimental evaluation

In 802.11 WLANs, adapting the contention parameters to network conditions results in substantial performance improvements. Even though the ability to change these parameters has been available in standard devices for years, so far no adaptive mechanism using this functionality has been validated in a realistic deployment. In this paper we report our experiences with implementing and evaluating two adaptive algorithms based on control theory, one centralized and one distributed, in a large-scale testbed consisting of 18 commercial off-the-shelf devices. We conduct extensive measurements, considering different network conditions in terms of number of active nodes, link qualities, and data traffic. We show that both algorithms significantly outperform the standard configuration in terms of total throughput. We also identify the limitations inherent in distributed schemes, and demonstrate that the centralized approach substantially improves performance under a large variety of scenarios, which confirms its suitability for real deployments.     

The soft x-ray instrument for materials studies at the linac coherent light source x-ray free-electron laser

The soft x-ray materials science instrument is the second operational beamline at the linac coherent light source x-ray free electron laser. The instrument operates with a photon energy range of 480-2000 eV and features a grating monochromator as well as bendable refocusing mirrors. A broad range of experimental stations may be installed to study diverse scientific topics such as: ultrafast chemistry, surface science, highly correlated electron systems, matter under extreme conditions, and laboratory astrophysics. Preliminary commissioning results are presented including the first soft x-ray single-shot energy spectrum from a free electron laser.     

Local and Regional Water Flow Quantification in Groundwater-dependent Wetlands

Runoff, groundwater recharge and discharge, and surface water–groundwater interaction are the main driving forces of wetlands. The quantification of such flows is crucial information in the restoration and management of groundwater-dependent wetlands. The objective of this work is to quantify groundwater inflow at the level of the hydrogeological basin, which discharges into the wetland in the coastal plain of the Río de la Plata (Argentina). It also aims at evaluating whether such inflow is affected by groundwater exploitation in the high plain adjacent to the wetland. On the basis of water level data, a model of hydrological behaviour was developed and then a numerical simulation to quantify groundwater inflow was carried out. The evolution of groundwater levels was analyzed considering three situations: one of them in natural conditions and two others under different groundwater exploitation conditions. In the first case, the inflow originates in the recharge from precipitation, in the local groundwater discharge from the adjacent high plain and in the regional one from the semi-confined aquifer. The exploitation of the semi-confined aquifer in the high plain causes the formation of a cone of depression which modifies the hydrodynamics of the wetland in the area adjacent to the extraction wells. The quantification of flows shows that groundwater exploitation in areas of the basin located out of the wetland may cause the volume of water flowing into the wetland through groundwater discharge to decrease by approximately 25 %. The importance of considering discharge wetlands as part of regional hydrogeological systems should be highlighted, mainly as regards the management of natural resources.     

The Response to Selection for Broad Male Response to Female Sex Pheromone and its Implications for Divergence in Close-Range Mating Behavior in the European Corn Borer Moth, Ostrinia nubilalis

Coordinated sexual communication systems, seen in many species of moths, are hypothesized to be under strong stabilizing natural selection. Stabilized communication systems should be resistant to change, but there are examples of species/populations that show great diversification. A possible solution is that it is directional sexual selection on variation in male response that drives evolution. We tested a component of this model by asking whether ‘rare’ males (ca. 5 % of all males in a population) of the European corn borer moth (ECB), Ostrinia nubilalis, that respond to the sex pheromones of both ECB and a different Ostrinia species (O. furnacalis, the Asian corn borer, ACB), might play an important role in diversification. We specifically tested, via artificial selection, whether this broad male response has an evolvable genetic component. We increased the frequency of broad male response from 5 to 70 % in 19 generations, showing that broad-responding males could be important for the evolution of novel communication systems in ECB. We did not find a broader range of mating acceptance of broad males by females of the base population, however, suggesting that broad response would be unlikely to increase in frequency without the involvement of other factors. However, we found that ECB selection-line females accepted a broader range of courting males, including those of ACB, than did females of the base population. Thus, a genetic correlation exists between broad, long-range response to female sex pheromone and the breadth of female acceptance of males at close range. These results are discussed in the context of evolution of novel communication systems in Ostrinia.     

Experimental analysis and modeling of bone marrow mesenchymal stem cells proliferation

In order to develop effective cell based therapies for treating several human diseases, it is necessary to increase the limited number of stem cells harvested from a single patient to be used in autologous transplantation. Along these lines, mathematical modeling may represent a useful tool for interpreting and rationalizing the in vitro expansion techniques, thus helping to find the optimal operative conditions. Specifically, this work addresses the mathematical simulation of the proliferation kinetics of sheep bone marrow mesenchymal stem cells (phenotypic characterized by flow-cytometric analysis), as model similar to the human one, seeded at different initial concentrations in petri dishes and expanded up to confluence. The sigmoidal temporal profiles of total counts obtained through classic hemocytometry are quantitatively interpreted by a novel model based on population balance approach capable to take into account the contact inhibition at confluence. First, the adjustable parameters of the proposed model are fitted against experimental data on population expansion starting from one single seeding concentration. Then, the reliability of the mathematical model is successfully tested through the prediction of cell proliferation kinetics carried out starting from different seeding concentrations.     

Influence of chronic Naltrexone treatment on growth hormone and insulin secretion in obese subjects

OBJECTIVE: Recent studies have demonstrated the restoration of a normal 24 h GH profile induced by a reduction of insulinaemia after weight loss, suggesting a reciprocal relationship between plasma insulin and GH concentrations. We aimed to clarify if an opiate-induced reduction in plasma insulin could affect GH secretion in obesity. DESIGN: We have studied the insulin response to an oral glucose tolerance test (OGTT) and the GH response to GHRH before and after prolonged treatment with Naltrexone (NTX). C-peptide, IGF-I, IGFBP-3 plasma levels and the IGF-I/IGFBP-3 molar ratio were also determined. SUBJECTS: Twelve obese women (aged 25-41 y; Body mass index (BMI): 31-39 kg/m2) and six lean normal women (aged 25-38; BMI: 19.8-23.1 kg/m2). MEASUREMENT: GH was determined by the IRMA method; insulin, C-peptide, IGF-I and IGFBP-3 were assayed by the RIA method. For molar comparison between IGF-I and IGFBP-3 we have considered 30.5 kDa the molar weight of IGFBP-3. Results are expressed as mean +/- s.e.m. RESULTS: We observed a significant decrease in basal concentration of both insulin (230.1 +/- 34.9 vs 133.2 +/- 16.9 pmol/L; P < 0.005) and C-peptide (3.7 +/- 0.3 vs 2.4 +/- 0.1 micrograms/L; P < 0.02). No modifications in the insulin secretory response to the OGTT were observed. A significant increase of the GHRH-induced GH peak response (7.7 +/- 1.4 vs 19.7 +/- 3.1 micrograms/L; P < 0.01) and GH-AUC (533 +/- 151 vs 1415 +/- 339 micrograms/L/120 min; P < 0.01) was found after NTX treatment. A negative correlation was found between basal insulin and GH peak values, both before (r = -0.641, P = 0.027) and after NTX (r = -0.714, P = 0.013). No modifications were found in IGF-I, IGFBP-3 and IGF-I/IGFBP-3 molar ratio. Moreover, NTX affected neither the insulin response to OGTT or IGF-I, IGFBP-3 and IGF-I/IGFBP-3 molar ratio in a group of six lean controls. Conversely, NTX significantly reduced the GH response to GHRH, when expressed as both peak and AUC values. CONCLUSIONS: The opiate antagonist significantly reduced basal insulin concentrations and augmented the GH response to GHRH in obese subjects. In the absence of modifications in IGF-I and IGFBP-3 plasma levels and their molar ratio, we propose that insulin may exert a negative feedback on GH secretion.