Filodormía. El arte de provocar sueño dictando clases de algo parecido a la filosofía

El reto verdadero para los profesores de filosofía no es dar grandes cantidades de contenido a nuestrosestudiantes, ni enseñar las teorías abstrusas y oscuras. Nuestro reto es mantenerlos despiertos en clase, atentos alo que la filosofía puede decirles para sus vidas, y evitar hacer de la filosofía algo tan lejano y aburrido que nadie,además de nosotros mismos, decida aproximarse a ella

Carta a un joven que estudiará filosofía

A partir de una serie de experiencias personales y profesionales esta carta, más que un documento académicoforma l, es una reflexión sobre la profesión del filósofo, su formación y campo de acción en el contextocolombiano

Evaluation of trace element status of organic dairy cattle

The present study aimed to evaluate trace mineral status of organic dairy herds in northern Spain and the sources of minerals in different types of feed. Blood samples from organic and conventional dairy cattle and feed samples from the respective farms were analysed by inductively coupled plasma mass spectrometry to determine the concentrations of the essential trace elements (cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), iodine (I), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se) and zinc (Zn)) and toxic trace elements (arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb)). Overall, no differences between organic and conventional farms were detected in serum concentrations of essential and toxic trace elements (except for higher concentrations of Cd on the organic farms), although a high level of inter-farm variation was detected in the organic systems, indicating that organic production greatly depends on the specific local conditions. The dietary concentrations of the essential trace elements I, Cu, Se and Zn were significantly higher in the conventional than in the organic systems, which can be attributed to the high concentration of these minerals in the concentrate feed. No differences in the concentrations of trace minerals were found in the other types of feed. Multivariate chemometric analysis was conducted to determine the contribution of different feed sources to the trace element status of the cattle. Concentrate samples were mainly associated with Co, Cu, I, Se and Zn (i.e. with the elements supplemented in this type of feed). However, pasture and grass silage were associated with soil-derived elements (As, Cr, Fe and Pb) which cattle may thus ingest during grazingThis study was supported by the Spanish Government (project code AGL2010-21026). Inmaculada Orjales is in receipt of a FPU fellowship (Ref. FPU14/01473) from the Spanish Ministry of Education, Culture and SportsS

Thermoelectric properties and intrinsic conduction processes in DBSA and NaSIPA doped polyanilines

Seeking to gain fundamental understanding of the thermoelectric (TE) behavior of polyanilines (PANIs), structure- property relationships of PANI nanorods, doped with dodecylbenzenesulfonic acid (DBSA) and 5-sulfoisophtalic acid sodium salt (NaSIPA), and prepared by an indirect synthetic route, are discussed in terms of the contribution of the acid concentrations on the thermoelectric properties. The synergistic combination of high doping level and layer structure, accounts for the moderately high electrical conductivities (σ) and low constant Seebeck coefficients (α) of PANI-DBSA. Conversely, the poor doping ability of NaSIPA and low crystallinity degree explain the low electrical conductivities along with significant increases in Seebeck coefficient values. In relation to conduction mechanisms, PANI-DBSA shows a hopping behavior with a carrier concentration of c≈0.49 (hole type), while PANI-NaSIPA displays a diffusive regime, characteristic of degenerate metallic semiconductors, with an estimated charge carrier density of n≈3 × 1021 e/cm3

Serum Neuregulin 4 is negatively correlated with insulin sensitivity in humans and impairs mitochondrial respiration in HepG2 cells

Neuregulin 4 (NRG4) has been described to improve metabolic disturbances linked to obesity status in rodent models. The findings in humans are controversial. We aimed to investigate circulating NRG4 in association with insulin action in humans and the possible mechanisms involved. Insulin sensitivity (euglycemic hyperinsulinemic clamp) and serum NRG4 concentration (ELISA) were analysed in subjects with a wide range of adiposity (n = 89). In vitro experiments with human HepG2 cell line were also performed. Serum NRG4 was negatively correlated with insulin sensitivity (r = −0.25, p = 0.02) and positively with the inflammatory marker high-sensitivity C reative protein (hsCRP). In fact, multivariant linear regression analyses showed that insulin sensitivity contributed to BMI-, age-, sex-, and hsCRP-adjusted 7.2% of the variance in serum NRG4 (p = 0.01). No significant associations were found with adiposity measures (BMI, waist circumference or fat mass), plasma lipids (HDL-, LDL-cholesterol, or fasting triglycerides) or markers of liver injury. Cultured hepatocyte HepG2 treatedwith human recombinantNRG4 had an impact on hepatocyte metabolism, leading to decreased gluconeogenic- and mitochondrial biogenesis-related gene expression, and reduced mitochondrial respiration, without effects on expression of lipid metabolism-related genes. Similar but more pronounced effects were found after neuregulin 1 administration. In conclusion, sustained higher serum levels of neuregulin-4, observed in insulin resistant patients may have deleterious effects on metabolic and mitochondrial function in hepatocytes. However, findings from in vitro experiments should be confirmed in human primary hepatocytes

Recensiones [Revista de Historia Económica Año XIV Primavera-Verano 1996 n. 2 pp. 477-528]

Editada en la Fundación Empresa PúblicaBeatriz Cárceles de Gea. Fraude y administración fiscal en Castilla La Comisión de Millones (1632-1658): Poder fiscal y privilegio jurídico-político (Por Juan Zafra Oteyza).-- Enric Tello. Cervera i la Segarra al segle XVIII. En els origens d`una Catalunya pobra, 1700-1860 (Por Tomás Peris Albentosa).-- Ángela Atienza. Propiedad y Señorío en Aragón. El clero regular entre la expansión y la crisis (1700-1835) (Por José Manuel Latorre Ciria).-- Michel Zylberberg. Une si duouce domination. Les milieux d'affaires français et l`Espagne vers 1780-1808 (Por Joan Caries Maixé Altes).-- Paloma Pastor Rey de Viñas. Historia de la Fábrica de Cristales de San Ildefonso durante la época de la Ilustración (1727-1810) (Por Juan Helguera Quijada).-- Ricardo Robledo Hernández. Economistas y reformadores españoles: La cuestión agraria (1760-1935) (Por Juan Antonio Carmona Pidal).-- Juan Pan Montojo. La bodega del mundo (1800-1936) (Por José Pujol Andréu).-- Moisés Llordén Miñambres. Desarrollo económico y urbano de Gijón en los siglos XIX y XX (Por Carlos Larrinaga Rodríguez).-- Manuel Montero. La California del hierro. Las minas y la modernización económica y social de Vizcaya (Por Antonio Escudero).-- Salvador Cruz Artacho. Caciques y campesinos. Poder político, modernización agraria y conflictividad rural en Granada. 1890-1923 (Por Luis Garrido González).-- Miguel Muñoz Rubio. Renfe (1941-1991). Medio siglo de ferrocarril público (Por Francisco Javier Vidal Olivares).-- Eric Hobsbawn. Historia del siglo XX. 1914-1991 (Por Gabriel Tortella).-- Marjorie Grice-Hutchinson. Ensayos sobre el pensamiento económico en España (Por José Luis García Ruiz).-- Richard N. Langlois y Paul L. Robertson. Firms, Markets and Economic Change. A Dynamic Theory of Business Institutions (Por Jesús M. Valdaliso).-- John Komlos (ed.). Stature, Living Standards, and Economic Development: Essays in Anthropometric History, y John Komlos (ed.). The Biological Standard of Living on Three Continents: Further Explorations in Anthropometric History (Por James Simpson)Publicad

Adipose tissue knockdown of lysozyme reduces local inflammation and improves adipogenesis in high-fat diet-fed mice

Chronic systemic low-level inflammation in metabolic disease is known to affect adipose tissue biology. Lysozyme (LYZ) is a major innate immune protein but its role in adipose tissue has not been investigated. Here, we aimed to investigate LYZ in human and rodents fat depots, and its possible role in obesity-associated adipose tissue dysfunction. LYZ mRNA and protein were identified to be highly expressed in adipose tissue from subjects with obesity and linked to systemic chronic-low grade inflammation, adipose tissue inflammation and metabolic disturbances, including hyperglycemia, dyslipidemia and decreased markers of adipose tissue adipogenesis. These findings were confirmed in experimental models after a high-fat diet in mice and rats and also in ob/ob mice. Importantly, specific inguinal and perigonadal white adipose tissue lysozyme (Lyz2) gene knockdown in high-fat diet-fed mice resulted in improved adipose tissue inflammation in parallel to reduced lysozyme activity. Of note, Lyz2 gene knockdown restored adipogenesis and reduced weight gain in this model. In conclusion, altogether these observations point to lysozyme as a new actor in obesity-associated adipose tissue dysfunction. The therapeutic targeting of lysozyme production might contribute to improve adipose tissue metabolic homeostasis

Activation of Endogenous H2S Biosynthesis or Supplementation with Exogenous H2S Enhances Adipose Tissue Adipogenesis and Preserves Adipocyte Physiology in Humans

Aims: To investigate the impact of exogenous hydrogen sulfide (H2S) and its endogenous biosynthesis on human adipocytes and adipose tissue in the context of obesity and insulin resistance. Results: Experiments in human adipose tissue explants and in isolated preadipocytes demonstrated that exogenous H2S or the activation of endogenous H2S biosynthesis resulted in increased adipogenesis, insulin action, sirtuin deacetylase, and PPARγ transcriptional activity, whereas chemical inhibition and gene knockdown of each enzyme generating H2S (CTH, CBS, MPST) led to altered adipocyte differentiation, cellular senescence, and increased inflammation. In agreement with these experimental data, visceral and subcutaneous adipose tissue expression of H2S-synthesising enzymes was significantly reduced in morbidly obese subjects in association with attenuated adipogenesis and increased markers of adipose tissue inflammation and senescence. Interestingly, weight-loss interventions (including bariatric surgery or diet/exercise) improved the expression of H2S biosynthesis-related genes. In human preadipocytes, the expression of CTH, CBS, and MPST genes and H2S production were dramatically increased during adipocyte differentiation. More importantly, the adipocyte proteome exhibiting persulfidation was characterized, disclosing that different proteins involved in fatty acid and lipid metabolism, the citrate cycle, insulin signaling, several adipokines, and PPAR, experienced the most dramatic persulfidation (85–98%). Innovation: No previous studies investigated the impact of H2S on human adipose tissue. This study suggests that the potentiation of adipose tissue H2S biosynthesis is a possible therapeutic approach to improve adipose tissue dysfunction in patients with obesity and insulin resistance. Conclusion: Altogether, these data supported the relevance of H2S biosynthesis in the modulation of human adipocyte physiology.Peer reviewe

The thirty gigahertz instrument receiver for the Q-U-I Joint Tenerife experiment: concept and experimental results

This paper presents the analysis, design, and characterization of the thirty gigahertz instrument receiver developed for the Q-U-I Joint Tenerife experiment. The receiver is aimed to obtain polarization data of the cosmic microwave background radiation from the sky, obtaining the Q,U, and I Stokes parameters of the incoming signal simultaneously. A comprehensive analysis of the theory behind the proposed receiver is presented for a linearly polarized input signal, and the functionality tests have demonstrated adequate results in terms of Stokes parameters, which validate the concept of the receiver based on electronic phase switching