Transgénicos : el tiempo confirma todos los temores

Los cultivos transgénicos se introdujeron en nuestra agricultura y alimentación hace ya más de 15 años, con la promesa de ayudar a solucionar muchos de los problemas de la agricultura. Quince años después, el tiempo ha confirmado todos los temores. A pesar de las dificultades para realizar una investigación independiente, existen ya sobradas evidencias científicas como sobre el terreno de sus graves impactos sociales, ambientales y económicos; además de su incompatibilidad con un modelo de agricultura social y sostenible en el marco de la Soberanía Alimentaria

Una panorámica de la ganadería industrial en el Estado español

En el Estado español el número de cabezas de ganado no deja de crecer, pero cada vez hay menos personas dedicadas a la ganadería. La industria cárnica ha convertido la ganadería en una actividad industrial más: deslocalizada, desligada del entorno y altamente dependiente de insumos externos. La parte productora está a merced de una industria que impone los precios y modos de producción mientras que la consumidora paga un alto precio en salud y medio ambiente por adquirir carne y productos lácteos baratos

Geometry Induced Biofilm Formation

Bacteria in aqueous environments usually gather to form aggregates called biofilms. In biofilms, cells display many behavioral differences from planktonic cells, such as a 1,000-fold increase in tolerance to antibiotics. Hospital-acquired infections are often caused by biofilm spread through medical systems. Design improvements hindering biofilm formation rely on identifying factors that favor their appearance. Geometry variations in medical flow circuits may trigger biofilm nucleation through vortical motion driving bacteria to walls. Detailed flow studies in mili and microfluidic devices support that observation. Once biofilm seeds are created, they proliferate forming filaments whose structure is again controlled by the geometry

Dynamics of elastic biofilm threads

Fac. de Ciencias MatemáticasFALSEunpu

The Economic Value of Basin Protection to Improve the Quality and Reliability of Potable Water Supply: Some Evidence from Ecuador

This study estimates the willingness to pay (WTP) of Loja’s households to protect two micro-basins that supply over 40 percent of potable water to the city. Results indicate that households have an average WTP of $5.80 per month, which corresponds to a 25 percent increase in the self-reported monthly water bill, to preserve the basins.Basin protection, contingent valuation, Loja, Ecuador, Environmental Economics and Policy, Land Economics/Use,

Queremos campesinos y campesinas, no casinos

Los juegos de azar guardan varias similitudes con el manejo que actualmente hacemos de nuestras materias primas y alimentos, o al revés, la actividad especulativa que caracteriza hoy en día a los mercados mundiales de alimentos parece imitar perfectamente las apuestas que se dan en la ruleta o el Black Jack. Y ninguna de estas dos actividades contribuye al desarrollo local ni al bienestar de las personas. ¿Aceptamos entonces en nuestros territorios proyectos como la instalación de Eurovegas

The impact of interactions, bars, bulges, and AGN on star formation efficiency in local massive galaxies

Using observations from the GASS and COLD GASS surveys and complementary data from SDSS and GALEX, we investigate the nature of variations in gas depletion time observed across the local massive galaxy population. The large and unbiased COLD GASS sample allows us to assess the relative importance of galaxy interactions, bar instabilities, morphologies and the presence of AGN in regulating star formation efficiency. Both the H2 mass fraction and depletion time vary as a function of the distance of a galaxy from the main sequence in the SFR-M* plane. The longest gas depletion times are found in below-main sequence bulge-dominated galaxies that are either gas-poor, or else on average less efficient than disk-dominated galaxy at converting into stars any cold gas they may have. We find no link between AGN and these long depletion times. The galaxies undergoing mergers or showing signs of morphological disruptions have the shortest molecular gas depletion times, while those hosting strong stellar bars have only marginally higher global star formation efficiencies as compared to matched control samples. Our interpretation is that depletion time variations are caused by changes in the ratio between the gas mass traced by the CO(1-0) observations, and the gas mass in high density star-forming cores, with interactions, mergers and bar instabilities able to locally increase pressure and raise the ratio of efficiently star-forming gas to CO-detected gas. Building a sample representative of the local massive galaxy population, we derive a global Kennicutt-Schmidt relation of slope 1.18+/-0.24, and observe structure within the scatter around this relation, with galaxies having low (high) stellar mass surface densities lying systematically above (below) the mean relation, suggesting that gas surface density is not the only parameter driving the global star formation ability of a galaxy.Comment: 19 pages, 12 figures, accepted for publication in Ap

Population attitudes and practices regarding the ‘traffic light’-style labeling in Ecuador

Introducción: La elección de alimentos es fundamental para la salud de las poblaciones. Las estrategias como las normas del etiquetado en los productos alimenticios podrían ayudar a que el consumidor tenga información clara de los alimentos que consume. Objetivos: Explorar la asociación del sexo y la edad con las actitudes y prácticas frente al etiquetado nutricional tipo “Semáforo Nutricional” en Ecuador. Material y métodos: Estudio transversal en una muestra por conveniencia de 622 sujetos de ambos sexos en 6 supermercados del área urbana de Riobamba durante los meses de septiembre de 2014 a febrero de 2015. Se realizaron contrastes de hipótesis de diferencias de proporciones y regresión logística para determinar la asociación de las actitudes y prácticas con el sexo y edad. Resultados: Respecto a las mujeres, los hombres (OR=1,58; IC95%: 1,13–2,21; p40 años (OR= 1,72; IC95%: 1,22–2,44; p=0,002) tienen más probabilidad de creer que actualmente hay demasiada presión para comer de forma saludable. Igualmente los hombres tienen menos probabilidad de creer que consumen demasiada grasa (OR=0,61; IC95%: 0,43–0,85; p=0,01) respecto a las mujeres. Los participantes de entre 18-40 años frente a >40 años tienen más probabilidad de tratar de reducir al mínimo la cantidad de azúcar (OR=2,41; IC95%: 1,55–3,76; p40 years (OR=1.72; 95%CI:1.22–2.44; p=0.002) are more likely to believe that there is currently too much pressure to eat healthily. Likewise, men are less likely to believe that they consume too much fat (OR=0.61; 95%CI:0.43–0.85; p=0.01) compared to women. Participants aged between 18-40 years are more likely to try to minimize the amount of sugar (OR=2.41; 95%CI:1.55–3.76; p<0.001), sal (OR=2.24; 95%CI:1.50–3.60; p<0.001) and fat consuming (OR=2.17; 95%CI:1.44-3.27; p<0.001) vs. 40 years. Conclusions: The attitudes and practices of the population regarding the ‘traffic light’-style nutritional labeling can vary with respect to age and sex

COLD GASS, an IRAM Legacy Survey of Molecular Gas in Massive Galaxies: II. The non-universality of the Molecular Gas Depletion Timescale

We study the relation between molecular gas and star formation in a volume-limited sample of 222 galaxies from the COLD GASS survey, with measurements of the CO(1-0) line from the IRAM 30m telescope. The galaxies are at redshifts 0.025<z<0.05 and have stellar masses in the range 10.0<log(M*/Msun)<11.5. The IRAM measurements are complemented by deep Arecibo HI observations and homogeneous SDSS and GALEX photometry. A reference sample that includes both UV and far-IR data is used to calibrate our estimates of star formation rates from the seven optical/UV bands. The mean molecular gas depletion timescale, tdep(H2), for all the galaxies in our sample is 1 Gyr, however tdep(H2) increases by a factor of 6 from a value of ~0.5 Gyr for galaxies with stellar masses of 10^10 Msun to ~3 Gyr for galaxies with masses of a few times 10^11 Msun. In contrast, the atomic gas depletion timescale remains contant at a value of around 3 Gyr. This implies that in high mass galaxies, molecular and atomic gas depletion timescales are comparable, but in low mass galaxies, molecular gas is being consumed much more quickly than atomic gas. The strongest dependences of tdep(H2) are on the stellar mass of the galaxy (parameterized as log tdep(H2)= (0.36+/-0.07)(log M* - 10.70)+(9.03+/-0.99)), and on the specific star formation rate. A single tdep(H2) versus sSFR relation is able to fit both "normal" star-forming galaxies in our COLD GASS sample, as well as more extreme starburst galaxies (LIRGs and ULIRGs), which have tdep(H2) < 10^8 yr. Normal galaxies at z=1-2 are displaced with respect to the local galaxy population in the tdep(H2) versus sSFR plane and have molecular gas depletion times that are a factor of 3-5 times longer at a given value of sSFR due to their significantly larger gas fractions.Comment: Accepted for publication in MNRAS. 19 pages, 11 figure