Small Heat Shock Protein 22 Improves Cognition and Learning in the Tauopathic Brain

The microtubule-associated protein tau pathologically accumulates and aggregates in Alzheimer’s disease (AD) and other tauopathies, leading to cognitive dysfunction and neuronal loss. Molecular chaperones, like small heat-shock proteins (sHsps), can help deter the accumulation of misfolded proteins, such as tau. Here, we tested the hypothesis that the overexpression of wild-type Hsp22 (wtHsp22) and its phosphomimetic (S24,57D) Hsp22 mutant (mtHsp22) could slow tau accumulation and preserve memory in a murine model of tauopathy, rTg4510. Our results show that Hsp22 protected against deficits in synaptic plasticity and cognition in the tauopathic brain. However, we did not detect a significant change in tau phosphorylation or levels in these mice. This led us to hypothesize that the functional benefit was realized through the restoration of dysfunctional pathways in hippocampi of tau transgenic mice since no significant benefit was measured in non-transgenic mice expressing wtHsp22 or mtHsp22. To identify these pathways, we performed mass spectrometry of tissue lysates from the injection site. Overall, our data reveal that Hsp22 overexpression in neurons promotes synaptic plasticity by regulating canonical pathways and upstream regulators that have been characterized as potential AD markers and synaptogenesis regulators, like EIF4E and NFKBIA.     

Wien-type oscillators using CCII+

The purpose of this paper is to show that exists a close relationship between some CCII⁺ based sinusoidal oscillators and the RC active second order oscillators with a single VCVS. These structures with CCII⁺ may be derived from the classic Wien-bridge oscillator, and four of them exhibit practical interest. They are canonical, the oscillation condition can be adjusted by a single resistor, and furthermore, they may be designed with the same procedure as their voltage amplifier counterparts. Experimental and simulation results supporting the theoretical analysis are given.     

On the estimation of the coefficient of variation for anisotropic diffusion speckle filtering.

In this paper, we focus on the problem of speckle removal by means of anisotropic diffusion and, specifically, on the importance of the correct estimation of the statistics involved. First, we derive an anisotropic diffusion filter that does not depend on a linear approximation of the speckle model assumed, which is the case of a previously reported filter, namely, SRAD. Then, we focus on the problem of estimation of the coefficient of variation of both signal and noise and of noise itself. Our experiments indicate that neighborhoods used for parameter estimation do not need to coincide with those used in the diffusion equations. Then, we show that, as long as the estimates are good enough, the filter proposed here and the SRAD perform fairly closely, a fact that emphasizes the importance of the correct estimation of the coefficients of variation.     

Sensitivity of a Groundwater Flow Model to Both Climatic Variations and Management Scenarios in a Semi-arid Region of SE Spain

Since 1980, southern Spain has registered a cycle of drought with magnitudes consistent with forecasts by the European Environment Agency on climate change for a 20 % decrease in precipitation in southern Europe due to the acceleration of global warming. The impact of this climatic event has been taken into account in drawing up water management plans for the basins affected. However, it has barely been considered in terms of the evolution of groundwater reserves or in their modelling, possibly because the effects are often masked by intensive anthropic withdrawals from regional water resources. This research uses a mathematical groundwater flow model to evaluate the reserve evolution in the Mancha Oriental aquifer system (SE Spain) due to impacts from this drought cycle. Its influence has been quantified (from 1980 to 2008) in the aquifer's storage deficit 23 Mm³/year and in the discharge volume of the Júcar River of 21 Mm³/year. Finally, three plausible scenarios are modelled with respect to 2027, the end date of the planning horizons proposed by Directive 2000/60/EC. These scenarios examine the economic repercussions on current groundwater resource management measurements. If the drought was to persist, the costs involved in the storage deficit were calculated in the range from 21.7 to 34.9 M€.     

A PRELIMINARY STUDY ON THE MAGNETIC TREATMENT OF FLUIDS

Although the influence of magnetic fields on paraffin deposition is still dimly understood, magnetic devices have been exploited by the petroleum industry to mitigate this problem. In this study, a series of experiments were carried out using a lab-scale magnetic conditioner and two kind of samples: paraffin mixture and crude oil. The investigated parameters were: exposition time, temperature, magnetic field intensity. paraffin type and content in the fluid and the reversibility of the observed alterations. The results indicate that magnetic fields, up to 1 Tesla applied at a temperature close to the Wax Appearance Temperature (WAT), reduce the apparent viscosity of the samples. This effect has been ascribed to changes in the paraffin crystal morphology promoted by the magnetic field. Scanning Electronic Microscopy (SEM) was fundamental to confirm this hypothesis.     

Evaluation of a GIS-Based Integrated Vulnerability Risk Assessment for the Mancha Oriental System (SE Spain)

It is widely recognized that groundwater-vulnerability maps are a useful tool for making decisions on designating pollution-vulnerable areas, in addition to being a requirement of European Directive 91/676/EEC. This study addressed the vulnerability of the Mancha Oriental System (MOS) to groundwater contamination with an integrated Generic and Agricultural DRASTIC model approach. In the MOS, groundwater is the sole water resource for a total population of about 275,000 inhabitants and for 1,000 km² of irrigated crops. DRASTIC vulnerability maps have been drawn up for two different years (1975 and 2002) in which the potentiometric surface has dropped dramatically (80 m in some areas) due to the considerable expansion of irrigated croplands. The quality of available resources has also deteriorated due to the agricultural practices and the discharge of wastewater effluents. Vulnerability maps are used to test the data on nitrate, sulphate, and chloride contents in groundwater in the Central and El Salobral-Los Llanos hydrogeologic domains of the MOS for 2002. Regardless of the method applied, the dramatic alteration in land use leads to a change in the DRASTIC index and vulnerability to groundwater contamination decreases for the study period. Vulnerability in the MOS increases in areas where the irrigation return flow is notable. The lack of a statistical correspondence between the DRASTIC index and the spatial distribution of nitrate, chloride, and sulphate contents and the distribution of the pollution load suggest that this method does not accurately assess the risk of the MOS to groundwater pollution.     

Lipid changes during long-term storage of canned tuna (Thunnus alalunga)

 In previous studies fluorescence detection at different excitation/emission maxima during common fish processing has been used. A bathochromic shift towards higher wavelength maxima was observed and measured as the ratio between absorption at two of the maxima tested. This fluorescence ratio (δF) value correlates positively with fish damage. In the present work, the influence of formaldehyde (FA) on the value δF was studied. A model system was set up in which FA reacted at 30°C for 25 days with propylamine and fish muscle. It was observed that FA was less able to produce fluorescent compounds compared with common fish oxidation products that were also tested, i. e. propanal and hexanal. However, in the presence of both lipid oxidation aldehydes, the FA-containing mixtures led to a higher δF value. Model systems consisting of FA and fatty fish (sardine) muscle produced more fluorescence than FA and lean fish (cod), because of the formation of lipid oxidation compounds under the reaction conditions of the former systems. It is thus concluded that the presence of FA in a reacting medium enhances fluorescence formation, such that δF be can used as an accurate measure of fish damage. It is thought that measurement of δF in processes such as the freezing of gadoid fish, in which both FA and lipid oxidation are produced, could be of benefit. Received: 23 June 1997     

Characterization of Paracoccidioides brasiliensis PbDfg5p, a cell-wall protein implicated in filamentous growth

The dimorphic fungus Paracoccidioides brasiliensis is the causative agent of the most frequent systemic mycosis in Latin America. In humans, infection starts by inhalation of fungal propagules, which reach the pulmonary epithelium and differentiate into the yeast parasitic phase. Here we describe the characterization of a Dfg5p (defective for filamentous growth) homologue of P. brasiliensis, a predictable cell wall protein, first identified in Saccharomyces cerevisiae. The protein, the cDNA and genomic sequences were analysed. The cloned cDNA was expressed in Escherichia coli and the purified rPbDfg5p was used to obtain polyclonal antibodies. Immunoelectron microscopy and biochemical studies demonstrated the presence of PbDfg5p in the fungal cell wall. Enzymatic treatments identified PbDfg5p as a beta-glucan linked protein that undergoes N-glycosylation. The rPbDfg5p bound to extracellular matrix components, indicating that those interactions could be important for initial steps leading to P. brasiliensis attachment and colonization of host tissues.     

Whey protein concentrate/λ-carrageenan systems: Effect of processing parameters on the dynamics of gelation and gel properties

The thermal characteristics, dynamics of gelation and gel properties of commercial whey protein concentrate (WPC), WPC/λ-carrageenan (λ-C) mixtures (M) and WPC/λ-C spray-dried mixtures (DM) have been characterized. In a second stage, the effect of the gelling variables (T, pH, total solid content) on gelation and textural properties of DM was evaluated through a Doehlert uniform shell design.The presence of λ-C either in mixtures (M) or in DM promoted the WPC gelation at lower concentration (8%). M showed higher rates of formation and better gel properties (higher hardness, adhesiveness, springiness and cohesiveness) than DM.Nevertheless, when the effects of pH (6.0–7.0), heating temperature (75–90 °C) and total solid content (12–20 wt%) on gelation dynamics and gel properties of DM were studied, gels with a wide range of rheological and textural properties were obtained. While pH did not affect the gelation dynamics, it had some effect on rheological and textural properties. Total solid content and heating temperature were the most important variables for the dynamics of gelation (gelation rate (1/t_gel), gelation temperature (T_gel), rate constant of gel structure development (k_G), elastic modulus after cooling (G′_c) and textural parameters (hardness, springiness and cohesiveness).     

Egg Albumin Microaggregates Containing Colistin for Oral Administration: Organoleptic Characteristics

In order to mask the bitter taste of drug, a microencapsulation method for the production of egg albumin microaggregates was employed. As model bitter-tasting drug, colistin sulfonate was used. The heat denaturation technique for egg albumin microaggregates (coagulation temperature: 60°C) is different from that for human serum albumin (coagulation temperature: l00°C), which is quite important for high temperature unstable drugs. This method was subsequently used to produce microaggregates with a size range of 108.76 ± 32 μm. The egg albumin microaggregates were able to improve the organoleptic characteristics of colistin sulfonate. Drug release from these microaggregates was confirmed by jitting the dissolution data to the equation of Peppas; this resulted in an n value of 0.9791, signifying zero-order kinetics.