High pressure induced changes on sarcoplasmic protein fraction and quality indicators

The combined effect of pressure and mild temperature treatments on bovine sarcoplasmic proteins and quality parameters was assessed. M. longissimus dorsi samples were pressurised in a range of 200–600 MPa and 10–30 °C. High Pressure Processing (HPP) induced a reduction of protein solubility (p < 0.001) compared to non-treated controls (NT), more pronounced above 200 MPa. HPP at pressures higher than 200 MPa induced a strong modification (p < 0.001) of meat colour and a reduction of water holding capacity (WHC). SDS–PAGE analysis demonstrated that HPP significantly modified the composition of the sarcoplasmic protein fraction. The pressurisation temperature mainly affected protein solubility and colour; a smaller effect was observed on protein profiles. Significant correlations (p < 0.001) between sarcoplasmic protein solubility and both expressible moisture (r = −0.78) and colour parameters (r = −0.81 to −0.91) suggest that pressure induced denaturation of sarcoplasmic proteins could influence to some extent WHC and colour modifications of beef. Changes in protein band intensities were also significantly correlated with protein solubility, meat lightness and expressible moisture. These results describe the changes induced by HPP on sarcoplasmic proteins and confirm a relationship between modification of the sarcoplasmic protein fraction and alteration of meat quality characteristics

Emergence of Swiss metropole and scaling properties of urban clusters

Defining the limits of an urban agglomeration is essential both for fundamental and applied studies in quantitative and theoretical geography. A simple and consistent way for defining such urban clusters is important for performing different statistical analysis and comparisons. Traditionally, agglomerations are defined using a rather qualitative approach based on various statistical measures. This definition varies generally from one country to another, and the data taken into account are different. In this paper, we explore the use of the City Clustering Algorithm (CCA) for the agglomeration definition in Switzerland. This algorithm provides a systemic and easy way to define an urban area based only on population data. The CCA allows the specification of the spatial resolution for defining the urban clusters. The results from different resolutions are compared and analysed, and the effect of filtering the data investigated. Different scales and parameters allow highlighting different phenomena. The study of Zipf's law using the visual rank-size rule shows that it is valid only for some specific urban clusters, inside a narrow range of the spatial resolution of the CCA. The scale where emergence of one main cluster occurs can also be found in the analysis using Zipf's law. The study of the urban clusters at different scales using the lacunarity measure - a complementary measure to the fractal dimension - allows to highlight the change of scale at a given range.

Influence on present-day coastal dynamics and evolution of a relict subaqueous delta lobe: Sol de Riu lobe, Ebro Delta. Continental Shelf Research, 74: 94-104. doi:10.1016/j.csr.2013.11.021

We used high-resolution swath-bathymetry data to characterise the morphology of the abandoned subaqueous Sol de Riu delta lobe in the Ebro Delta, Western Mediterranean Sea. This study aims to assess the influence of an abandoned delta lobe on present-day coastal dynamics in a micro-tidal environment. Detailed mapping of the relict Sol de Riu lobe also showed a set of bedforms interpreted as footprints of human activities: seasonal V-shaped depressions on the middle shoreface due to boat anchoring and old trawling marks between 16 and 18 m water depth. Estimations of the mobility of bottom sediment showed that the shallowest shoreface (i.e. less than 7 m depth) is the most dynamic part of the relict lobe, while the middle shoreface experienced significant morphological changes since the lobe was abandoned. The deepest shoreface (i.e. water depth in excess of 15 m), which corresponds to the front of the lobe, is defined by a very small potential for morphological change. Simulations showed that while the relict lobe does not significantly affect the typical short period waves (Tp ≈4 s) in the study area, it does interfere with the most energetic wave conditions (Tp ≥ 7 s) acting as a shoal leading to the concentration of wave energy along the shoreline northwest of the lobe. The consequence of such modification of the high-energy wave propagation pattern by the relict lobe is an alteration of the wave-induced littoral sediment dynamics with respect to a situation without the lobe.

Microstructural evolution of primary crystallization in diffusion-controlled grain growth

A model has been developed for evaluating grain size distributions in primary crystallizations where the grain growth is diffusion controlled. The body of the model is grounded in a recently presented mean-field integration of the nucleation and growth kinetic equations, modified conveniently in order to take into account a radius-dependent growth rate, as occurs in diffusion-controlled growth. The classical diffusion theory is considered, and a modification of this is proposed to take into account interference of the diffusion profiles between neighbor grains. The potentiality of the mean-field model to give detailed information on the grain size distribution and transformed volume fraction for transformations driven by nucleation and either interface- or diffusion-controlled growth processes is demonstrated. The model is evaluated for the primary crystallization of an amorphous alloy, giving an excellent agreement with experimental data. Grain size distributions are computed, and their properties are discussed.

La construcción de la imagen de la política en los noticiarios televisivos en España. Exo- y endo- equilibrios de la calidad de la información política

En nuestra sociedad la imagen que los ciudadanos tenemos de la política está fuertemente condicionada por cómo esta aparece en los medios de comunicación y, en particular, en los noticiarios televisivos. Este artículo, fruto de un proyecto de investigación I+D+I financiado por el Ministerio de Educación, Política Social y Deporte, analiza las noticias de temática política de ocho canales de televisión en España con el objetivo de comprobar cuál es la presencia de la política en los noticiarios, qué imagen se construye de la política en ellos. Además, propone una nueva metodología para establecer la calidad de las informaciones políticas en los noticiarios televisivos en España a través de la definición de los endo- y exo- equilibrios de los contenidos políticos de los noticiarios. Las principales conclusiones del artículo son que los noticiarios que construyen una imagen más equilibrada de la política son los de Televisión Española y Cuatro, mientras que los que construyen una imagen más desequilibrada son los de la Sexta y Canal 9. El porcentaje de noticias dedicadas a la política no depende ni de la titularidad (pública-privada), ni del ámbito de cobertura (estatal-autonómica) del canal. En cambio, sí podemos encontrar una relación en la suma de las noticias de política (political issues) y las de gobernanza (policy issues).

La intensificación agrícola y la diversidad vegetal en los sistemas cerealistas de secano mediterráneos: implicaciones para la conservación

El trabajo analiza la importancia de la diversidad vegetal en los agroecosistemas y los efectos de la intensificación de las prácticas agrícolas y del paisaje sobre la diversidad vegetal. La revisión de diversos estudios llevados a cabo por el equipo de investigación permite destacar que la intensificación agrícola, tanto a escala de campo como de paisaje, afecta negativamente la abundancia y la riqueza específica de la flora. La comparación de la flora arvense de los cultivos cerealistas de secano mediterráneos entre los años 50 y la actualidad refleja la reducción de la flora arvense, especialmente de la flora propia de las mieses y la disminución de la abundancia de grupos funcionales como las leguminosas y las plantas entomófilas. El efecto de las prácticas agrícolas y de la complejidad del paisaje varía en función de la flora estudiada. Así, la complejidad del paisaje es el principal factor que afecta la configuración de la vegetación de los márgenes, mientras que la intensidad de las prácticas agrícolas es el principal factor para explicar las diferencias en la flora arvense en el centro de los campos. Por último, el artículo analiza diversas propuestas para la gestión de los agrosistemas con el objetivo de conciliar la producción agrícola y la conservación de la biodiversidad en la región mediterránea.

Determination and Evaluation of Alternate Methods for Managing and Controlling Highway-Related Dust, TR-449, 2002

Road dust is caused by wind entraining fine material from the roadway surface and the main source of Iowa road dust is attrition of carbonate rock used as aggregate. The mechanisms of dust suppression can be considered as two processes: increasing particle size of the surface fines by agglomeration and inhibiting degradation of the coarse material. Agglomeration may occur by capillary tension in the pore water, surfactants that increase bonding between clay particles, and cements that bind the mineral matter together. Hygroscopic dust suppressants such as calcium chloride have short durations of effectiveness because capillary tension is the primary agglomeration mechanism. Somewhat more permanent methods of agglomeration result from chemicals that cement smaller particles into a mat or larger particles. The cements include lignosulfonates, resins, and asphalt products. The duration of the cements depend on their solubility and the climate. The only dust palliative that decreases aggregate degradation is shredded shingles that act as cushions between aggregate particles. It is likely that synthetic polymers also provide some protection against coarse aggregate attrition. Calcium chloride and lignosulfonates are widely used in Iowa. Both palliatives have a useful duration of about 6 months. Calcium chloride is effective with surface soils of moderate fine content and plasticity whereas lignin works best with materials that have high fine content and high plasticity indices. Bentonite appears to be effective for up to two years and works well with surface materials having low fines and plasticity and works well with limestone aggregate. Selection of appropriate dust suppressants should be based on characterization of the road surface material. Estimation of dosage rates for potential palliatives can be based on data from this report, from technical reports, information from reliable vendors, or laboratory screening tests. The selection should include economic analysis of construction and maintenance costs. The effectiveness of the treatment should be evaluated by any of the field performance measuring techniques discussed in this report. Novel dust control agents that need research for potential application in Iowa include; acidulated soybean oil (soapstock), soybean oil, ground up asphalt shingles, and foamed asphalt. New laboratory evaluation protocols to screen additives for potential effectiveness and determine dosage are needed. A modification of ASTM D 560 to estimate the freeze-thaw and wet-dry durability of Portland cement stabilized soils would be a starting point for improved laboratory testing of dust palliatives.

Selecting highly affine and well-expressed TCRs for gene therapy of melanoma.

A recent phase 1 trial has demonstrated that the generation of tumor-reactive T lymphocytes by transfer of specific T-cell receptor (TCR) genes into autologous lymphocytes is feasible. However, compared with results obtained by infusion of tumor-infiltrating lymphocytes, the response rate observed in this first TCR gene therapy trial is low. One strategy that is likely to enhance the success rate of TCR gene therapy is the use of tumor-reactive TCRs with a higher capacity for tumor cell recognition. We therefore sought to develop standardized procedures for the selection of well-expressed, high-affinity, and safe human TCRs. Here we show that TCR surface expression can be improved by modification of TCR alpha and beta sequences and that such improvement has a marked effect on the in vivo function of TCR gene-modified T cells. From a panel of human, melanoma-reactive TCRs we subsequently selected the TCR with the highest affinity. Furthermore, a generally applicable assay was used to assess the lack of alloreactivity of this TCR against a large series of common human leukocyte antigen alleles. The procedures described in this study should be of general value for the selection of well- and stably expressed, high-affinity, and safe human TCRs for subsequent clinical testing.

Enzyme activities and pectin breakdown of sapodilla submitted to 1-methylcyclopropene

The objective of this work was to investigate the influence of 1-methylcyclopropene (1-MCP) at 300 nL L-1 on activities of cell wall hidrolytic enzymes and pectin breakdown changes which Sapodilla (Manilkara zapota cv. Itapirema 31) cell wall undergoes during ripening. Sapodilla were treated with ethylene antagonist 1-MCP at 300 nL L-1 for 12 hours and then, stored under a modified atmosphere at 25º C for 23 days. Firmness, total and soluble pectin and cell wall enzymes were monitored during storage. 1-MCP at 300 nL L-1 for 12 hours delayed significantly softening of sapodilla for 11 days at 25º C. 1-MCP postharvest treatment affected the activities of cell wall degrading enzymes pectinmethylesterase and polygalacturonase and completely suppressed increases in beta-galactosidase for 8 days, resulting in less pectin solubilization. Beta-galactosidase seems relevant to softening of sapodilla and is probably responsible for modification of both pectin and xyloglucan-cellulose microfibril network.

Pin guidance of reconstruction plate contour: an expanded role of external fixation

This article presents a modification of intraoperative external fixation for mandibular reconstruction with free tissue flaps. This technique is indicated when preregistration of the reconstruction plate is not possible due to transmandibular tumor extension. Once standard external fixation has been carried out and prior to segmental mandibulectomy, additional pins are fixed to the connecting rod that delineate the mandibular contour in three-dimensional (3D) space. Following mandibulectomy, these pins allow accurate contouring of the reconstruction plate and improved restoration of mandibular contour, projection, and dental occlusion. A step-by-step description of the technique using models and intraoperative photos is presented. This method of mandibular reconstruction is a simple and time-effective alternative to intraoperative computer navigation and 3D modeling in select cases of oral carcinoma where tumor infiltration of the outer mandibular cortex precludes prebending of the reconstruction plates.

La ciència de la (in)justícia

Estudis recents proven que les decisions judicials estan també determinades per factors psicologics, politics i socials.

Study of OSEM with different subsets in grating-based X-ray differential phase-contrast imaging.

Impressive developments in X-ray imaging are associated with X-ray phase contrast computed tomography based on grating interferometry, a technique that provides increased contrast compared with conventional absorption-based imaging. A new "single-step" method capable of separating phase information from other contributions has been recently proposed. This approach not only simplifies data-acquisition procedures, but, compared with the existing phase step approach, significantly reduces the dose delivered to a sample. However, the image reconstruction procedure is more demanding than for traditional methods and new algorithms have to be developed to take advantage of the "single-step" method. In the work discussed in this paper, a fast iterative image reconstruction method named OSEM (ordered subsets expectation maximization) was applied to experimental data to evaluate its performance and range of applicability. The OSEM algorithm with different subsets was also characterized by comparison of reconstruction image quality and convergence speed. Computer simulations and experimental results confirm the reliability of this new algorithm for phase-contrast computed tomography applications. Compared with the traditional filtered back projection algorithm, in particular in the presence of a noisy acquisition, it furnishes better images at a higher spatial resolution and with lower noise. We emphasize that the method is highly compatible with future X-ray phase contrast imaging clinical applications.

Differential stress reaction of human colon cells to oleic-acid-stabilized and unstabilized ultrasmall iron oxide nanoparticles.

Therapeutic engineered nanoparticles (NPs), including ultrasmall superparamagnetic iron oxide (USPIO) NPs, may accumulate in the lower digestive tract following ingestion or injection. In order to evaluate the reaction of human colon cells to USPIO NPs, the effects of non-stabilized USPIO NPs (NS-USPIO NPs), oleic-acid-stabilized USPIO NPs (OA-USPIO NPs), and free oleic acid (OA) were compared in human HT29 and CaCo2 colon epithelial cancer cells. First the biophysical characteristics of NS-USPIO NPs and OA-USPIO NPs in water, in cell culture medium supplemented with fetal calf serum, and in cell culture medium preconditioned by HT29 and CaCo₂ cells were determined. Then, stress responses of the cells were evaluated following exposure to NS-USPIO NPs, OA-USPIO NPs, and free OA. No modification of the cytoskeletal actin network was observed. Cell response to stress, including markers of apoptosis and DNA repair, oxidative stress and degradative/autophagic stress, induction of heat shock protein, or lipid metabolism was determined in cells exposed to the two NPs. Induction of an autophagic response was observed in the two cell lines for both NPs but not free OA, while the other stress responses were cell- and NP-specific. The formation of lipid vacuoles/droplets was demonstrated in HT29 and CaCo₂ cells exposed to OA-USPIO NPs but not to NS-USPIO NPs, and to a much lower level in cells exposed to equimolar concentrations of free OA. Therefore, the induction of lipid vacuoles in colon cells exposed to OA utilized as a stabilizer for USPIO NPs is higly amplified compared to free OA, and is not observed in the absence of this lipid in NS-USPIO NPs.

Evolution and functional characterisation of the IR chemosensory receptors in the Drosophila larval gustatory system

Chemosensory receptor gene families encode divergent proteins capable of detecting a huge diversity of environmental stimuli that are constantly changing over evolutionary time as organisms adapt to distinct ecological niches. While olfaction is dedicated to the detection of volatile compounds, taste is key to assess food quality for nutritional value and presence of toxic substances. The sense of taste also provides initial signals to mediate endocrine regulation of appetite and food metabolism and plays a role in kin recognition. The fruit fly Drosophila melanogaster is a very good model for studying smell and taste because these senses are very important in insects and because a broad variety of genetic tools are available in Drosophila. Recently, a family of 66 chemosensory receptors, the Ionotropic Receptors (IRs) was described in fruit flies. IRs are distantly related to ionotropic glutamate receptors (iGluRs), but their evolutionary origin from these synaptic receptors is unclear. While 16 IRs are expressed in the olfactory system, nothing is known about the other members of this repertoire. In this thesis, I describe bioinformatic, expression and functional analyses of the IRs aimed at understanding how these receptors have evolved, and at characterising the role of the non-olfactory IRs. I show that these have emerged at the basis of the protostome lineage and probably have acquired their sensory function very early. Moreover, although several IRs are conserved across insects, there are rapid and dramatic changes in the size and divergence of IR repertoires across species. I then performed a comprehensive analysis of IR expression in the larva of Drosophila melanogaster, which is a good model to study taste and feeding mechanisms as it spends most of its time eating or foraging. I found that most of the divergent members of the IR repertoire are expressed in both peripheral and internal gustatory neurons, suggesting that these are involved in taste perception. Finally, through the establishment of a new neurophysiological assay in larvae, I identified for the first time subsets of IR neurons that preferentially detect sugars and amino acids, indicating that IRs might be involved in sensing these compounds. Together, my results indicate that IRs are an evolutionarily dynamic and functionally versatile family of receptors. In contrast to the olfactory IRs that are well-conserved, gustatory IRs are rapidly evolving species-specific receptors that are likely to be involved in detecting a wide variety of tastants. - La plupart des animaux possèdent de grandes familles de récepteurs chimiosensoriels dont la fonction est de détecter l'immense diversité de composés chimiques présents dans l'environnement. Ces récepteurs évoluent en même temps que les organismes s'adaptent à leur écosystème. Il existe deux manières de percevoir ces signaux chimiques : l'olfaction et le goût. Alors que le système olfactif perçoit les composés volatiles, le sens du goût permet d'évaluer, par contact, la qualité de la nourriture, de détecter des substances toxiques et de réguler l'appétit et le métabolisme. L'un des organismes modèles les plus pertinents pour étudier le sens du goût est le stade larvaire de la mouche du vinaigre Drosophila melanogaster. En effet, la principale fonction du stade larvaire est de trouver de la nourriture et de manger. De plus, il est possible d'utiliser tous les outils génétiques développés chez la drosophile. Récemment, une nouvelle famille de 66 récepteurs chimiosensoriels appelés Récepteurs Ionotropiques (IRs) a été découverte chez la drosophile. Bien que leur orogine soit peu claire, ces récepteurs sont similaires aux récepteurs ionotropiques glutamatergiques impliqués dans la transmission synaptique. 16 IRs sont exprimés dans le système olfactif de la mouche adulte, mais pour l'instant on ne connaît rien des autres membres de cette famille. Durant ma thèse, j'ai effectué des recherches sur l'évolution de ces récepteurs ainsi que sur l'expression et la fonction des IRs non olfactifs. Je démontre que les IRs sont apparus chez l'ancêtre commun des protostomiens et ont probablement acquis leur fonction sensorielle très rapidement. De plus, bien qu'un certain nombre d'IRs olfactifs soient conservés chez les insectes, d'importantes variations dans la taille et la divergence des répertoires d'IRs entre les espèces ont été constatées. J'ai également découvert qu'un grand nombre d'IRs non olfactifs sont exprimés dans différents organes gustatifs, ce qui leur confère probablement une fonction dans la perception des goûts. Finalement, pour la première fois, des neurones exprimant des IRs ont été identifiés pour leur fonction dans la perception de sucres et d'acides aminés chez la larve. Mes résultats présentent les IRs comme une famille très dynamique, aux fonctions très variées, qui joue un rôle tant dans l'odorat que dans le goût, et dont la fonction est restée importante tout au long de l'évolution. De plus, l'identification de neurones spécialisés dans la perception de certains composés permettra l'étude des circuits neuronaux impliqués dans le traitement de ces informations.

Dissociation between components of spatial memory in rats after recovery from the effects of retrohippocampal lesions

A series of 4 experiments examined the performance of rats with retrohippocampal lesions on a spatial water-maze task. The animals were trained to find and escape onto a hidden platform after swimming in a large pool of opaque water. The platform was invisible and could not be located using olfactory cues. Successful escape performance required the rats to develop strategies of approaching the correct location with reference solely to distal extramaze cues. The lesions encompassed the entire rostro-caudal extent of the lateral and medial entorhinal cortex, and included parts of the pre- and para-subiculum, angular bundle and subiculum. Groups ECR 1 and 2 sustained only partial damage of the subiculum, while Group ECR+S sustained extensive damage. These groups were compared with sham-lesion and unoperated control groups. In Expt 1A, a profound deficit in spatial localisation was found in groups ECR 1 and ECR+S, the rats receiving all training postoperatively. In Expt 1B, these two groups showed hyperactivity in an open-field. In Expt 2, extensive preoperative training caused a transitory saving in performance of the spatial task by group ECR 2, but comparisons with the groups of Expt 1A revealed no sustained improvement, except on one measure of performance in a post-training transfer test. All rats were then given (Expt 3) training on a cueing procedure using a visible platform. The spatial deficit disappeared but, on returning to the normal hidden platform procedure, it reappeared. Nevertheless, a final transfer test, during which the platform was removed from the apparatus, revealed a dissociation between two independent measures of performance: the rats with ECR lesions failed to search for the hidden platform but repeatedly crossed its correct location accurately during traverses of the entire pool. This partial recovery of performance was not (Expt 4) associated with any ability to discriminate between two locations in the pool. The apparently selective recovery of aspects of spatial memory is discussed in relation to O'Keefe and Nadel's (1978) spatial mapping theory of hippocampal function. We propose a modification of the theory in terms of a dissociation between procedural and declarative subcomponents of spatial memory. The declarative component is a flexible access system in which information is stored in a form independent of action. It is permanently lost after the lesion. The procedural component is "unmasked" by the retrohippocampal lesion giving rise to the partial recovery of spatial localisation performance.