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Short-term vitamin E treatment impairs reactive oxygen species signaling required for adipose tissue expansion, resulting in fatty liver and insulin resistance in obese mice

  • Alcalá, Martín
  • Calderón Domínguez, María
  • Serra i Cucurull, Dolors
  • Herrero Rodríguez, Laura
  • Ramos, Maria P.
  • Viana Arribas, Marta
Objectives The use of antioxidant therapy in the treatment of oxidative stress-related diseases such as cardiovascular disease, diabetes or obesity remains controversial. Our aim is to demonstrate that antioxidant supplementation may promote negative effects if used before the establishment of oxidative stress due to a reduced ROS generation under physiological levels, in a mice model of obesity. Methods C57BL/6J mice were fed with a high-fat diet for 14 weeks, with (OE group) or without (O group) vitamin E supplementation. Results O mice developed a mild degree of obesity, which was not enough to induce metabolic alterations or oxidative stress. These animals exhibited a healthy expansion of retroperitoneal white adipose tissue (rpWAT) and the liver showed no signs of lipotoxicity. Interestingly, despite achieving a similar body weight, OE mice were insulin resistant. In the rpWAT they presented a reduced generation of ROS, even below physiological levels (C: 1651.0 ± 212.0; O: 3113 ± 284.7; OE: 917.6 ±104.4 RFU/mg protein. C vs OE p< 0.01). ROS decay may impair their action as second messengers, which could account for the reduced adipocyte differentiation, lipid transport and adipogenesis compared to the O group. Together, these processes limited the expansion of this fat pad and as a consequence, lipid flux shifted towards the liver, causing steatosis and hepatomegaly, which may contribute to the marked insulin resistance. Conclusions This study provides in vivo evidence for the role of ROS as second messengers in adipogenesis, lipid metabolism and insulin signaling. Reducing ROS generation below physiological levels when the oxidative process has not yet been established may be the cause of the controversial results obtained by antioxidant therapy.

Causes and consequences of individual variability and specialization in foraging and migration strategies of seabirds

  • Phillips, Richard, A
  • Lewis, Sue
  • González-Solís, Jacob
  • Daunt, Francis
Technological advances in recent years have seen an explosion of tracking and stable isotope studies of seabirds, often involving repeated measures from the same individuals. This wealth of new information has allowed the examination of the extensive variation among and within individuals in foraging and migration strategies (movements, habitat use, feeding behaviour, trophic status, etc.) in unprecedented detail. Variation is underpinned by key life-history or state variables such as sex, age, breeding stage and residual differences among individuals (termed 'individual specialization'). This variation has major implications for our understanding of seabird ecology, because it affects the use of resources, level of intra-specific competition and niche partitioning. In addition, it determines the responses of individuals and populations to the environment and the susceptibility to major anthropogenic threats. Here we review the effects of season (breeding vs. nonbreeding periods), breeding stage, breeding status, age, sex and individual specialization on foraging and migration strategies, as well as the consequences for population dynamics and conservation.

NIR Monitoring and Modelling of Soybean Oil Methanolysis with Multivariate Curve Resolution-Alternating Least Squares with Correlation Constraint

  • Sales, Rafaella F.
  • Lima, Suzana M. de
  • Stragevitch, Luiz
  • Pimentel, Maria Fernanda
  • Juan Capdevila, Anna de
Near infrared spectroscopy in-line monitoring and modelling of soybean oil methanolysis has been done using multivariate curve resolution alternating least squares (MCR-ALS) with correlation constraint. This constraint allows for quantitation of the methyl ester formed with little calibration effort and the MCR model provides additionally a general description (qualitative and quantitative) of the rest of components in the process. Due to the complexity of this process, which shows components with severe kinetic and spectral overlap, suitably designed multiset analysis strategies were adopted to improve the recovery of concentration profiles of the methyl ester. To assess the temperature and catalyst concentration effects on the kinetic reaction, five batches with different temperatures (20, 44 and 55 °C) and catalyst concentrations (0.75 and 1 m/m%) were produced. The concentration profiles of methyl ester obtained by MCR-ALS for each batch was the starting information used to develop a simplified kinetic model and calculate the activation energy.

Gut microbiota in a rat oral sensitization model: effect of a cocoa-enriched diet

  • Camps Bossacoma, Mariona
  • Pérez-Cano, Francisco J.
  • Franch i Masferrer, Àngels
  • Castell, Margarida
Increasing evidence is emerging suggesting a relation between dietary compounds, microbiota, and the susceptibility to allergic diseases, particularly food allergy. Cocoa, a source of antioxidant polyphenols, has shown effects on gut microbiota and the ability to promote tolerance in an oral sensitization model. Taking these facts into consideration, the aim of the present study was to establish the influence of an oral sensitization model, both alone and together with a cocoa-enriched diet, on gut microbiota. Lewis rats were orally sensitized and fed with either a standard or 10% cocoa diet. Faecal microbiota was analysed through metagenomics study. Intestinal IgA concentration was also determined. Oral sensitization produced few changes in intestinal microbiota, but in those rats fed a cocoa diet significant modifications appeared. Decreased bacteria from the Firmicutes and Proteobacteria phyla and a higher percentage of bacteria belonging to the Tenericutes and Cyanobacteria phyla were observed. In conclusion, a cocoa diet is able to modify the microbiota bacterial pattern in orally sensitized animals. As cocoa inhibits the synthesis of specific antibodies and also intestinal IgA, those changes in microbiota pattern, particularly those of the Proteobacteria phylum, might be partially responsible for the tolerogenic effect of cocoa.

Taming active turbulence with patterned soft interfaces

  • Guillamat Bassedas, Pau
  • Ignés i Mullol, Jordi
  • Sagués i Mestre, Francesc
Active matter embraces systems that self-organize at different length and time scales, often exhibiting turbulent flows. Here, we use a quasi-two-dimensional nematically ordered layer of a protein-based active gel to experimentally demonstrate that the geometry of active flows, which we have characterized by means of the statistical distribution of eddy sizes, can be reversibly modified. To this purpose, the active material is prepared in contact with a thermotropic liquid crystal, whose lamellar smectic-A phase tiles the water/oil interface with a lattice of anisotropic domains that feature circular easy-flow directions. The active flow, which arises from the motion of parabolic folds within the filamentous active material, becomes effectively confined into circulating eddies that are in registry with the underlying smectic-A domains. Based on topological arguments applied to the circular confinement, together with well-known properties of the active material, we show that the structure of the active flow is determined by a single intrinsic length scale. The role of this length scale thus reemerges from setting the decay length in the exponential eddy size distribution of the free turbulent regime, to determining the minimum size of circulating eddies featuring a scale-free power law. Our results demonstrate that soft-confinement provides with an invaluable tool to probe the intrinsic length and time scales of active materials, and pave the way for further exploration looking for similarities and differences between active and passive two-dimensional turbulence.

Business taxes and the electoral cycle

  • Foremny, Dirk
  • Riedel, Nadine
The purpose of this paper is to assess whether the timing of elections affects tax policy choices. To do so, we exploit information on the German local business tax which is set autonomously by German municipalities. As the dates for local council elections vary across German states, the data allows us to disentangle effects related to the timing of elections from common trends. The findings support the notion of a political cycle in tax setting as the growth in local business tax rates is significantly reduced in the election year and the year prior to the election, while it significantly increases in the year after the election. This pattern turns out to be robust against a number of sensitivity checks.

Evaluation of the impact of Bus Rapid Transit on air pollution in Mexico City

  • Bel i Queralt, Germà, 1963-
  • Holst, Maximilian
Mexico City's bus rapid transit (BRT) network, Metrobus, was introduced in an attempt to reduce congestion, increase city transport efficiency and cut air polluting emissions. In June 2005, the first BRT line in the metropolitan area began service. We use the differences-in-differences technique to make the first quantitative assessment of the policy impact of a BRT system on air polluting emissions. The air pollutants considered are carbon monoxide (CO), nitrogen oxides (NOX), particulate matter of less than 10 µm (PM10), and sulfur dioxide (SO2). The ex-post analysis uses real field data from air quality monitoring stations for periods before and after BRT implementation. Results show that BRT constitutes an effective environmental policy, reducing emissions of CO, NOX, and PM10.

A revision of the revaluation index of Spanish pensions

  • Roch, Oriol
  • Bosch Príncep, Manuela
  • Morillo, Isabel
  • Vilalta de Miguel, Daniel
This article reviews the methodological aspects of the revaluation index of Spanish pensions developed following Law 23/2013 which regulates the sustainability factor and revaluation index of the Social Security pension system. From a gradual breakdown of the elements that make up the revaluation index, an exposition is given of the formal and implementation problems it involves. Finally, an alternative model based on dynamic optimization techniques is proposed and its use is illustrated with numerical examples.

Failure of ProTaper rotary Ni-Ti instruments used by undergraduate students

  • García Font, Marc
  • Duran-Sindreu, Fernando
  • Morello Castro, Sergio
  • Mercadé Bellido, Montserrat
  • Bueno Martínez, Rufino
  • Roig Cayón, Miguel
Objective: To evaluate the effect of number of uses, angle and radius of curvature and type of instrument on the fracture of ProTaper rotary instruments when used by undergraduate students. Study design: Three hundred and seventy-six molars, with a total of 1114 root canals, extracted were instrumented by undergraduate students using ProTaper instruments according to the manufacturer´s recommendations. When fracture occurred, data were collected concerning the number of uses, type of instrument, level of fracture, angle and radius of curvature. ANOVA test were used to determine the influence of type of instrument in the incidence of instrument fracture. Logistic regression model was used to determine the influence of number of uses, angle and radius of curvature in the incidence of instrument fracture. Significance was set at p< 0.05. Results: A total of 37 Ni-Ti rotary instruments fractured during the treatment. Fracture occurred in 9.84% (37/376) of the teeth treated and 3.32% of the canals prepared with Ni-Ti rotary instruments (37/1114). A decrease in the radius of curvature of the canal significantly increased the likelihood of fracture (p=0.0001). Instrument fracture significantly increased as the number of uses increased (p=0.0037). No significant differences were found between the 6 types of ProTaper instruments (p=0.8). A reduction in the angle of curvature did not produce a significant decrease in the incidence of instrument separation (p=0.08). Conclusions: The results of this study imply that instrument fracture is linked to radius of curvature and number of uses

Discovery and validation of new potential biomarkers for early detection of colon cancer

  • Solé Acha, Xavier
  • Crous Bou, Marta
  • Cordero Romera, David
  • Olivares, David
  • Guinó, Elisabet
  • Sanz Pamplona, Rebeca
  • Rodríguez Moranta, Francisco
  • Sanjuan, Xavier
  • Oca Burguete, Javier de
  • Salazar Soler, Ramón
  • Moreno Aguado, Víctor
Background: accurate detection of characteristic proteins secreted by colon cancer tumor cells in biological fluids could serve as a biomarker for the disease. The aim of the present study was to identify and validate new serum biomarkers and demonstrate their potential usefulness for early diagnosis of colon cancer. Methods: the study was organized in three sequential phases: 1) biomarker discovery, 2) technical and biological validation, and 3) proof of concept to test the potential clinical use of selected biomarkers. A prioritized subset of the differentially-expressed genes between tissue types (50 colon mucosa from cancer-free individuals and 100 normal-tumor pairs from colon cancer patients) was validated and further tested in a series of serum samples from 80 colon cancer cases, 23 patients with adenoma and 77 cancer-free controls.Results: in the discovery phase, 505 unique candidate biomarkers were identified, with highly significant results and high capacity to discriminate between the different tissue types. After a subsequent prioritization, all tested genes (N = 23) were successfully validated in tissue, and one of them, COL10A1, showed relevant differences in serum protein levels between controls, patients with adenoma (p = 0.0083) and colon cancer cases (p = 3.2e-6). Conclusion: we present a sequential process for the identification and further validation of biomarkers for early detection of colon cancer that identifies COL10A1 protein levels in serum as a potential diagnostic candidate to detect both adenoma lesions and tumor. Impact:the use of a cheap serum test for colon cancer screening should improve its participation rates and contribute to decrease the burden of this disease.

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