Over-stimulation of insulin/IGF-1 signaling by western diet may promote diseases of civilization: lessons learnt from laron syndrome

The insulin/insulin-like growth factor-1 (IGF-1) pathway drives an evolutionarily conserved network that regulates lifespan and longevity. Individuals with Laron syndrome who carry mutations in the growth hormone receptor (GHR) gene that lead to severe congenital IGF-1 deficiency with decreased insulin/IGF-1 signaling (IIS) exhibit reduced prevalence rates of acne, diabetes and cancer. Western diet with high intake of hyperglycemic carbohydrates and insulinotropic dairy over-stimulates IIS. The reduction of IIS in Laron subjects unmasks the potential role of persistent hyperactive IIS mediated by Western diet in the development of diseases of civilization and offers a rational perspective for dietary adjustments with less insulinotropic diets like the Paleolithic diet

ONE SIZE FITS ALL? THE CONTINGENT ROLE OF CENTRALITY IN IT NETWORK GOVERNANCE

Inter-organizational collaboration in terms of co-creation, co-development, and co-innovation relies heavily on integrated information systems that support reciprocal relations among member organizations. Ensuring desirable behavior in the use of these inter-organizational IT resources is subject to the emerging research on IT network governance. While past studies have concentrated on singular governance arrangements, there is no study that examines the fit of governance choice and internal and external network factors on governance effectiveness. This paper contributes with a characterization of IT network governance arrangements along the degree of centralization of IT-related decision making. Three archetypes are distinguished: a decentralized mode, a hybrid mode, and a centralized mode. Moreover, a contingency model is developed proposing effective governance arrangements according to six contingency variables. A multiple case study methodology is applied with five case sides for validation. Our data indicate support for both the theoretical archetypes and the contingency model. The results suggest that network size, network structure centralization, functional diversity, network trust, IT infusion, and IT competence are important contingencies for the understanding of effective IT network governance arrangements. This research is a first step into a contingent perspective on inter-organizational IT governance arrangements

A hexapod walker using a heterarchical architecture for action selection

Schilling M, Paskarbeit J, Hoinville T, et al. A hexapod walker using a heterarchical architecture for action selection. Frontiers in Computational Neuroscience. 2013;7:126.Moving in a cluttered environment with a six-legged walking machine that has additional body actuators, therefore controlling 22 DoFs, is not a trivial task. Already simple forward walking on a flat plane requires the system to select between different internal states. The orchestration of these states depends on walking velocity and on external disturbances. Such disturbances occur continuously, for example due to irregular up-and-down movements of the body or slipping of the legs, even on flat surfaces, in particular when negotiating tight curves. The number of possible states is further increased when the system is allowed to walk backward or when front legs are used as grippers and cannot contribute to walking. Further states are necessary for expansion that allow for navigation. Here we demonstrate a solution for the selection and sequencing of different (attractor) states required to control different behaviors as are forward walking at different speeds, backward walking, as well as negotiation of tight curves. This selection is made by a recurrent neural network (RNN) of motivation units, controlling a bank of decentralized memory elements in combination with the feedback through the environment. The underlying heterarchical architecture of the network allows to select various combinations of these elements. This modular approach representing an example of neural reuse of a limited number of procedures allows for adaptation to different internal and external conditions. A way is sketched as to how this approach may be expanded to form a cognitive system being able to plan ahead. This architecture is characterized by different types of modules being arranged in layers and columns, but the complete network can also be considered as a holistic system showing emergent properties which cannot be attributed to a specific module

Differences in the microbiota of native and non-indigenous gelatinous zooplankton organisms in a low saline environment

Highlights: • Non-indigenous species (NIS) are increasingly recognized as a matter of concern. • The microbiome of native and NIS gelatinous zooplankton organisms are compared. • Next generation sequencing confirms sign. Species specific microbiome differences. • Indicator OTUs include bacteria which contain known pathogenic strains. • Microbiome monitoring of NIS should be considered for aquaculture risk assessments. Abstract: The translocation of non-indigenous species (NIS) around the world, especially in marine systems, is increasingly being recognized as a matter of concern. Species translocations have been shown to lead to wide ranging changes in food web structure and functioning. In addition to the direct effects of NIS, they could facilitate the accumulation or translocation of bacteria as part of their microbiomes. The Baltic Sea harbours many non-indigenous species, with most recent detection of the jellyfish Blackfordia virginica and the comb jelly Mnemiopsis leidyi in the low saline southwestern Baltic Sea. In this study, we used a multidisciplinary approach and investigated three gelatinous zooplankton species that co-occur in the same environment and feed on similar zooplankton food sources but show different histories of origin. The aim was to conduct a comparative microbiome analysis of indigenous and non-indigenous gelatinous zooplankton species in the low-saline southwestern Baltic Sea. Next-generation 16S rRNA marker gene sequencing of the V1/V2 region was employed to study the bacterial microbiome compositions. All tested species showed significant differences in their microbiome compositions (one way ANOSIM, R = 1, P < 0.008) with dissimilarities ranging from 85 to 92%. The indigenous jellyfish Aurelia aurita showed the highest bacterial operational taxonomic unit (OTU) richness. The overall differentiation between microbiomes was driven by eight indicator OTUs, which included Mycoplasma and Vibrio species. These bacteria can be problematic, as they include known pathogenic strains that are relevant to human health and aquaculture activities. Our results suggest that the impact assessment of NIS should consider potential pathogenic bacteria, enriched in the environment due to invasion, as potential risks to aquaculture activities

Mapping of the range of operational conditions for Cu-, Fe-, and Ni-based oxygen carriers in chemical-looping combustion

Available online September 14, 2006.- El pdf del artículo es la versión post-printChemical-looping combustion (CLC) is a two-step combustion process that produces a pure CO2 stream, ready for compression and sequestration. A CLC system is composed by two reactors, an air and a fuel reactor, and an oxygen carrier (OC) circulating between the reactors, which transfers the oxygen necessary for the fuel combustion from the air to the fuel. This system can be designed similar to a circulating fluidised bed, but with the addition of a bubbling fluidised bed on the return side. A mapping of the range of operational conditions, design values, and OC characteristics is presented for the most usual metal oxides (CuO, Fe2O3, and NiO) and different fuel gases (CH4, H2, and CO). The pressure operation of a CLC system is also considered. Moreover, a comparison of the possible use of three high reactive OCs (Cu10Al-I, Fe45Al-FG, Ni40Al-FG) previously characterised is carried out. It was found that the circulation rates and the solids inventories are linked, and the possible operating conditions are closely dependent on the reactivity of the OCs. The operational limits of the solids circulation rates, given by the mass and heat balances in the system, were defined for the different type of OCs. Moreover, a plot to calculate the solids inventories in a CLC system, valid for any type of OC and fuel gas, is proposed. The minimum solids inventories depended on the fuel gas used, and followed the order CH4 > CO > H2. Values of minimum solids inventories in a range from 40 to 133 kg / MWf were found for the OCs used in this work, excepting for the reaction of Fe45Al-FG with CH4, which needs a higher amount of solids because of its low reactivity. From the economic analysis carried out it was found the cost of the OC particles does not represent any limitation to the development of the CLC technology. © 2006 Elsevier Ltd. All rights reserved.This work was carried out with financial support from the European Coal and Steel Community (Project 7220-PR/125), and the Spanish Ministry of Education and Science (Project CTQ2004- 04034).Peer Reviewe

Hemolysis at low blood flow rates: in-vitro and in-silico evaluation of a centrifugal blood pump

Background Treating severe forms of the acute respiratory distress syndrome and cardiac failure, extracorporeal membrane oxygenation (ECMO) has become an established therapeutic option. Neonatal or pediatric patients receiving ECMO, and patients undergoing extracorporeal CO2 removal (ECCO2R) represent low-flow applications of the technology, requiring lower blood flow than conventional ECMO. Centrifugal blood pumps as a core element of modern ECMO therapy present favorable operating characteristics in the high blood flow range (4 L/min–8 L/min). However, during low-flow applications in the range of 0.5 L/min–2 L/min, adverse events such as increased hemolysis, platelet activation and bleeding complications are reported frequently. Methods In this study, the hemolysis of the centrifugal pump DP3 is evaluated both in vitro and in silico, comparing the low-flow operation at 1 L/min to the high-flow operation at 4 L/min. Results Increased hemolysis occurs at low-flow, both in vitro and in silico. The in-vitro experiments present a sixfold higher relative increased hemolysis at low-flow. Compared to high-flow operation, a more than 3.5-fold increase in blood recirculation within the pump head can be observed in the low-flow range in silico. Conclusions This study highlights the underappreciated hemolysis in centrifugal pumps within the low-flow range, i.e. during pediatric ECMO or ECCO2R treatment. The in-vitro results of hemolysis and the in-silico computational fluid dynamic simulations of flow paths within the pumps raise awareness about blood damage that occurs when using centrifugal pumps at low-flow operating points. These findings underline the urgent need for a specific pump optimized for low-flow treatment. Due to the inherent problems of available centrifugal pumps in the low-flow range, clinicians should use the current centrifugal pumps with caution, alternatively other pumping principles such as positive displacement pumps may be discussed in the future