The effect of solvent and electric field on the size distribution of iron oxide microdots: Exploitation of self-assembly strategies for photoelectrodes

An increasing number of technologies benefit from or require patterned surfaces on a micro- and nanoscale. Methods developed to structure polymer films can be adapted to fabricate low-cost patterned ceramics using nonlithographic techniques, for example, dewetting and phase separation in thin films. In this paper we describe a simple patterning process that does not require a template and is able to produce Fe2O3 microdots with a spatial periodicity. Our method involves the dewetting of a silicon substrate by a thin metal oxide precursor film, in which the liquid film breaks up because of fluctuations in the film thickness induced by solvent evaporation or an external applied electric field. The patterning is followed by a thermal treatment at 550 °C to produce crystalline Fe2O3 microdots with a diameter range of 200 nm to 3 μ

Dynamic control and information processing in the Belousov-Zhabotinsky reaction using a coevolutionary algorithm

We propose that the behavior of nonlinear media can be controlled dynamically through coevolutionary systems. In this study, a light-sensitive subexcitable Belousov-Zhabotinsky reaction is controlled using a heterogeneous cellular automaton. A checkerboard image comprising of varying light intensity cells is projected onto the surface of a catalyst-loaded gel resulting in rich spatiotemporal chemical wave behavior. The coevolved cellular automaton is shown to be able to either increase or decrease chemical activity through dynamic control of the light intensity within each cell in both simulated and real chemical systems. The approach is then extended to construct a number of simple logical functions. © 2008 American Institute of Physics

Haptoglobin Polymorphism: A Novel Genetic Risk Factor for Celiac Disease Development and Its Clinical Manifestations

Background: Haptoglobin (Hp) α-chain alleles 1 and 2 account for 3 phenotypes that may influence the course of inflammatory diseases via biologically important differences in their antioxidant, scavenging, and immunomodulatory properties. Hp1-1 genotype results in the production of small dimeric, Hp2-1 linear, and Hp2-2 cyclic polymeric haptoglobin molecules. We investigated the haptoglobin polymorphism in patients with celiac disease and its possible association to the presenting symptoms. Methods: We studied 712 unrelated, biopsy-proven Hungarian celiac patients (357 children, 355 adults; severe malabsorption 32.9%, minor gastrointestinal symptoms 22.8%, iron deficiency anemia 9.4%, dermatitis herpetiformis 15.6%, silent disease 7.2%, other 12.1%) and 384 healthy subjects. We determined haptoglobin phenotypes by gel electrophoresis and assigned corresponding genotypes. Results: Hp2-1 was associated with a significant risk for celiac disease (P = 0.0006, odds ratio [OR] 1.54, 95% CI 1.20–1.98; prevalence 56.9% in patients vs 46.1% in controls). It was also overrepresented among patients with mild symptoms (69.2%) or silent disease (72.5%). Hp2-2 was less frequent in patients than in controls (P = 0.0023), but patients having this phenotype were at an increased risk for severe malabsorption (OR 2.21, 95% CI 1.60–3.07) and accounted for 45.3% of all malabsorption cases. Celiac and dermatitis herpetiformis patients showed similar haptoglobin phenotype distributions. Conclusions: The haptoglobin polymorphism is associated with susceptibility to celiac disease and its clinical presentations. The predominant genotype in the celiac population was Hp2-1, but Hp2-2 predisposed to a more severe clinical course. The phenotype-dependent effect of haptoglobin may result from the molecule’s structural and functional properties

The rsmS (ybaM) mutation causes bypass suppression of the RsmAB post-transcriptional virulence regulation system in enterobacterial phytopathogens.

Plant cell wall degrading enzymes (PCWDEs) are the primary virulence determinants of soft rotting bacteria such as the potato pathogen, Pectobacterium atrosepticum. The regulation of secondary metabolite (Rsm) system controls production of PCWDEs in response to changing nutrient conditions. This work identified a new suppressor of an rsmB mutation - ECA1172 or rsmS (rsmB suppressor). Mutants defective in rsmB (encoding a small regulatory RNA), show reduced elaboration of the quorum sensing molecule (N-3-oxohexanoyl-homoserine lactone; OHHL) and PCWDEs. However, OHHL and PCWDE production were partially restored in an rsmB, rsmS double mutant. Single rsmS mutants, overproduced PCWDEs and OHHL relative to wild type P. atrosepticum and exhibited hypervirulence in potato. RsmS overproduction also resulted in increased PCWDEs and OHHL. Homology searches revealed rsmS conservation across pathogens such as Escherichia coli (ybaM), Dickeya solani, Klebsiella pneumoniae and Shigella flexneri. An rsmS mutant of Pectobacterium carotovorum ATCC39048 showed bypass of rsmB-dependent repression of PCWDEs and OHHL production. P. carotovorum ATCC39048 produces the β-lactam antibiotic, 1-carbapen-2-em-3-carboxylic acid (a carbapenem). Production of the antibiotic was repressed in an rsmB mutant but partially restored in an rsmB, rsmS double mutant. This work highlights the importance of RsmS, as a conserved pleiotropic regulator of virulence and antibiotic biosynthesis.James Hutton Institut

Maze solving using temperature-induced Marangoni flow

A temperature gradient can be utilized for maze solving using a temperature-induced Marangoni flow. Induced liquid flow drags passive tracers such as small dye particles, which dissolve in a water phase thus visualizing the shortest path.</p

Implementation of Glider Guns in the Light-Sensitive Belousov-Zhabotinsky Medium

In cellular automata models a glider gun is an oscillating pattern of non-quiescent states that periodically emits traveling localizations (gliders). The glider streams can be combined to construct functionally complete systems of logical gates and thus realize universal computation. The glider gun is the only means of ensuring the negation operation without additional external input and therefore is an essential component of a collision-based computing circuit. We demonstrate the existence of glider gun like structures in both experimental and numerical studies of an excitable chemical system -- the light-sensitive Belousov-Zhabotinsky reaction. These discoveries could provide the basis for future designs of collision-based reaction-diffusion computers.Comment: Accepted for publication in Physical Review

Review of global change pressures on Urban Water Cycle Systems. Assessment of TRUST Pilots

The design of appropriate tools to deal with future stresses requires an understanding of the potential pressures, either opportunities or threats. This report identifies and describes different pressures of critical importance for the water sector, taking into account that global trends often take diverse forms and have dissimilar impacts on a local scale. Chapter 1 introduces the UWCS components and the sustainability approach considered in this context. In Chapter 2 the different pressures affecting UWCS are framed according to the sustainability dimensions: environmental, social and economic. A general description of relevant pressures is presented in terms of context situation, geographic dependency and expected tendencies for the future. Chapter 3 identifies possible future trends on UWCS according to those pressures. Their consideration will allow many countries to undergo considerable changes and to define strategies to solve impending problems and exploit emerging opportunities. Based on the identified trends for the water sector, Chapter 4 presents the prediction of major global change pressures and its impacts on Pilots of TRUST. The two annexes of this report present the principal climatic drivers, in terms of the future projection of weather variables (precipitation and temperature) in the areas of the TRUST pilot citiesRamôa, AR.; Toth, E.; Proença De Oliveira, R.; Di Frederico, V.; Montanari, A.; Monteiro, AJ. (2015). Review of global change pressures on Urban Water Cycle Systems. Assessment of TRUST Pilots. http://hdl.handle.net/10251/5364

Immunomodulatory Effects of the Neuropeptide Pituitary Adenylate Cyclase-Activating Polypeptide in Acute Toxoplasmosis

Pituitary Adenylate Cyclase-Activating Polypeptide (PACAP) is an endogenous neuropeptide with distinct functions including the regulation of inflammatory processes. PACAP is able to modify the immune response by directly regulating macrophages and monocytes inhibiting the production of inflammatory cytokines, chemokines and free radicals. Here, we analyzed the effect of exogenous PACAP on peripheral immune cell subsets upon acute infection with the parasite Toxoplasma gondii (T. gondii). PACAP administration was followed by diminished innate immune cell recruitment to the peritoneal cavity of T. gondii-infected mice. PACAP did not directly interfere with parasite replication, instead, indirectly reduced parasite burden in mononuclear cell populations by enhancing their phagocytic capacity. Although proinflammatory cytokine levels were attenuated in the periphery upon PACAP treatment, interleukin (IL)-10 and Transforming growth factor beta (TGF-β) remained stable. While PACAP modulated VPAC1 and VPAC2 receptors in immune cells upon binding, it also increased their expression of brain-derived neurotrophic factor (BDNF). In addition, the expression of p75 neurotrophin receptor (p75NTR) on Ly6Chi inflammatory monocytes was diminished upon PACAP administration. Our findings highlight the immunomodulatory effect of PACAP on peripheral immune cell subsets during acute Toxoplasmosis, providing new insights about host-pathogen interaction and the effects of neuropeptides during inflammation

Spatial and temporal dynamics of fucoid populations (Ascophyllum nodosum and Fucus serratus): A comparison between central and range edge populations

Persistence of populations at range edges relies on local population dynamics and fitness, in the case of geographically isolated populations of species with low dispersal potential. Focusing on spatial variations in demography helps to predict the long-term capability for persistence of populations across the geographical range of species' distribution. The demography of two ecological and phylogenetically close macroalgal species with different life history characteristics was investigated by using stochastic, stage-based matrix models. Populations of Ascophyllum nodosum and Fucus serratus were sampled for up to 4 years at central locations in France and at their southern range limits in Portugal. The stochastic population growth rate (lambda(s)) of A. nodosum was lower and more variable in central than in southern sites whilst for F. serratus this trend was reversed with lambda(s) much lower and more variable in southern than in central populations. Individuals were larger in central than in southern populations for both species, which was reflected in the lower transition probabilities of individuals to larger size classes and higher probability of shrinkage in the southern populations. In both central and southern populations elasticity analysis (proportional sensitivity) of population growth rate showed that fertility elements had a small contribution to lambda(s) that was more sensitive to changes in matrix transitions corresponding to survival. The highest elasticities were found for loop transitions in A. nodosum and for growth to larger size classes in F. serratus. Sensitivity analysis showed high selective pressure on individual growth for both species at both locations. The results of this study highlight the deterministic role of species-specific life-history traits in population demography across the geographical range of species. Additionally, this study demonstrates that individuals' life-transitions differ in vulnerability to environmental variability and shows the importance of vegetative compared to reproductive stages for the long-term persistence of populations.Portuguese Foundation for Science and Technology (FCT) [SFRH/BPD/75843/2011]; European Regional Development Fund (ERDF) through the COMPETE - Operational Competitiveness Programme; FCT [Pest-CIMAR LA 0015/2013, EXCL/AAG-GLO/0661/2012