Feeding of nauplii, copepodites and adults of Calanipeda aquaedulcis (Calanoida) in Mediterranean salt marshes

Feeding of the different developmental stages of Calanipeda aquaedulcis on natural particles (bacterio-, phyto- and microzooplankton) was measured in a Mediterranean salt marsh (Empordà wetlands, NE Iberian Peninsula). Bottle incubations were performed in the field both in autumn and spring. The results showed differences in the diet of the different developmental stages due to both prey type and size. In general, the size of the ingested prey increased with increasing size of the C. aquaedulcis stage. While C. aquaedulcis adults had high ingestion rates and selection coefficients for large prey (micro- and nanoplankton), nauplii preferentially consumed smaller prey items (picoplankton). Copepodites showed the widest prey size range, including pico-, nano- and microplankton. Nevertheless, the lower size limit for particle capture was similar for all stages, i.e. between 1.7 and 2.1 μm. Omnivory was observed in all stages of C. aquaedulcis. Heterotrophic prey (picoplankton, dinoflagellates and ciliates) were the most ingested items. The ability to partition the available food among the different developmental stages could represent an advantage in times of ood scarcity because it may reduce intraspecific competition. This may explain how C. aquaedulcis is able to predominate in the zooplankton community for several weeks during spring and summer ven in situations of low food availability

Estabilitzador de tensió, a partir d'una reactància de nucli saturable

Actualment hi ha una gran varietat de marques i models d'estabilitzadors de tensió, tot i que tots estan dissenyats i construïts amb el mateix propòsit, entregar una tensió estable a la sortida del dispositiu. La raó per la que es fabriquen estabilitzadors de tensió, es basa en el fet que, tot i amb els avenços tècnics i millores dels serveis de l'àrea energètica, no s'han pogut eliminar les freqüents caigudes o pujades de tensió en les xarxes d'alimentació d'energia elèctrica, fet que pot ocasionar errors en el funcionament dels equips electrònics. És per això que la majoria d'usuaris d'equips electrònics interposen un estabilitzador de tensió entre la línea d'alimentació dels seus aparells. L'objectiu del treball és realitzar la construcció d'un dispositiu de tres bobines amb un nucli ferromagnètic per a dur a terme la funció d'estabilitzador de tensió alterna. Mitjançant la tècnica de reluctància de nucli saturable i aplicant-la en aquest cas pràctic, es vol aconseguir desenvolupar un estabilitzador de tensió fiable i econòmic. Aquest treball ha d'aportar una solució en entorns de treball, entre altres, on s'utilitzen màquines d'alimentació alternes que siguin molt sensibles a les variacions de tensió de la xarxa i que, a més a més, no suposi una despesa molt elevada.

Frontshear and backshear instabilities of the mean longshore current

An analytical model based on Bowen and Holman [1989] is used to prove the existence of instabilities due to the presence of a second extremum of the background vorticity at the front side of the longshore current. The growth rate of the so-called frontshear waves depends primarily upon the frontshear but also upon the backshear and the maximum and the width of the current. Depending on the values of these parameters, either the frontshear or the backshear instabilities may dominate. Both types of waves have a cross-shore extension of the order of the width of the current, but the frontshear modes are localized closer to the coast than are the backshear modes. Moreover, under certain conditions both unstable waves have similar growth rates with close wave numbers and angular frequencies, leading to the possibility of having modulated shear waves in the alongshore direction. Numerical analysis performed on realistic current profiles confirm the behavior anticipated by the analytical model. The theory has been applied to a current profile fitted to data measured during the 1980 Nearshore Sediment Transport Studies experiment at Leadbetter Beach that has an extremum of background vorticity at the front side of the current. In this case and in agreement with field observations, the model predicts instability, whereas the theory based only on backshear instability fai led to do so.

A subcritical instability of wave-driven alongshore currents

The development of shear instabilities of a wave-driven alongshore current is investigated. In particular, we use weakly nonlinear theory to investigate the possibility that such instabilities, which have been observed at various sites on the U.S. coast and in the laboratory, can grow in linearly stable flows as a subcritical bifurcation by resonant triad interaction, as first suggested by Shrira eta/. [1997]. We examine a realistic longshore current profile and include the effects of eddy viscosity and bottom friction. We show that according to the weakly nonlinear theory, resonance is possible and that these linearly stable flows may exhibit explosive instabilities. We show that this phenomenon may occur also when there is only approximate resonance, which is more likely in nature. Furthermore, the size of the perturbation that is required to trigger the instability is shown in some circumstances to be consistent with the size of naturally occurring perturbations. Finally, we consider the differences between the present case examined and the more idealized case of Shrira et a/. [ 1997]. It is shown that there is a possibility of coupling between triads, due to the richer modal structure in more realistic flows, which may act to stabilize the flow and act against the development of subcritical bifurcations. Extensive numerical tests are called for.

Estudi de la població de Spiraea crenata subsp. parvifolia (Rosaceae) del Collsacabra

Spiraea crenata subsp. parvifolia és un tàxon endèmic del nord-est ibèric, que té una de les escasses poblacions conegudes al Collsacabra, Osona. En aquest treball es pretén definir l’extensió d’aquesta població, caracteritzar la seva estructura demogràfica i avaluar-ne l’estat de conservació. La majoria d’individus censats viuen en un nucli principal rodejat per nuclis més petits. L’estabilitat de l’ambient que ocupa permet valorar l’evolució de la població i la categoria UICN d’amenaça, actualment considerada «en perill ». Es proposen mesures de gestió que permetin la conservació d’aquesta població.

Memoria oral y alimentación: estrategias de supervivencia durante la Guerra Civil Española (1936-1939) y la posguerra (1939-1955)

El principal objetivo de nuestro tra bajo es delimitar las prácticas de reciprocidad que se llevaron a cabo durante el período de tiempo analizado y que permitieron reproducirse socialmente a los grupos menos favorecidos por la guerra y la posguerra . Nuestro análisis demuestra que la alimentación es un sistema de comuni - cación mediante el cual se crean o mantienen prácticas de poder , así como expre - siones de identidad y/o defensa o ruptura de las normas morales que comparte un grupo social .

Food Indicators and Their Relationship with 10 to 12 Year-olds' Subjective Well-Being

This study aimed to test subjective indicators designed to analyze the role food plays in children’s lives, explore children’s personal well-being, and evaluate the relationship between these two phenomena. It was conducted on 371 children aged 10 to 12 by means of a selfadministered questionnaire. Results showed a marked interest in food on the part of children, who consider taste and health the most important indicators when it comes to eating. They demonstrated a high level of personal well-being, measured using Cummins & Lau’s adapted version of the Personal Well- Being Index–School Children (PWI-SC) (2005), overall life satisfaction (OLS) and satisfaction with various life domains (friends, family, sports, food and body). Regression models were conducted to explain satisfaction with food, taking as independent variables the interest children have in food, the importance they give to different reasons for eating, scores from the PWI-SC, OLS and satisfaction with various life domains. In the final model, it was found that OLS, health indicators, satisfaction with health from the PWI-SC and satisfaction with your body contribute to explaining satisfaction with food. The results obtained suggest that satisfaction with food is a relevant indicator in the exploration of children’s subjective well-being, calling into question the widespread belief that these aspects are of exclusive interest to adults. They also seem to reinforce the importance of including food indicators in any study aimed at exploring the well-being of the 10 to 12 year-old population.

What determines the wavelength of self-organized shoreline sand waves?

Shoreline undulations extending into the bathymetric contours with a length scale larger than that of the rhythmic surf zone bars are referred to as shoreline sand waves. Many observed undulations along sandy coasts display a wavelength in the order 1-7 km. Several models that are based on the hypothesis that sand waves emerge from a morphodynamic instability in case of very oblique wave incidence predict this range of wavelengths. Here we investigate the physical reasons for the wavelength selection and the main parametric trends of the wavelength in case of sand waves arising from such instability. It is shown that the existence of a minimum wavelength depends on an interplay between three factors affecting littoral drift: (A) the angle of wave fronts relative to local shoreline, which tends to cause maximum transport at the downdrift flank of the sand wave, (B) the refractive energy spreading which tends to cause maximum transport at the updrift flank and (C) wave focusing (de-focusing) by the capes (bays), which tends to cause maximum transport at the crest or slightly downdrift of it. Processes A and C cause decay of the sand waves while process B causes their growth. For low incidence angles, B is very weak so that a rectilinear shoreline is stable. For large angles and long sand waves, B is dominant and causes the growth of sand waves. For large angles and short sand waves C is dominant and the sand waves decay. Thus, wavelength selection depends on process C, which essentially depends on shoreline curvature. The growth rate of very long sand waves is weak because the alongshore gradients in sediment transport decrease with the wavelength. This is why there is an optimum or dominant wavelength. It is found that sand wave wavelength scales with λ0/β where λ0 is the water wave wavelength in deep water and β is the mean bed slope from shore to the wave base.

Projecte d’ampliació i millores de l’explotació bovina de cria “CAN PEREAULET” de Bescanó

L’explotació ramadera a projectar és la “Can Pereaulet”, situada a la finca Can Pereaulet, situada al terme municipal de Bescanó, a la comarca del Gironès, manté una estructura d’àmbit familiar.L’objectiu d’aquest projecte és ampliar la capacitat de la granja Can Pereaulet per poder deslletar els vedells, millorar el benestar animal i la producció de vedells per a engreix a 600 vedells/any. La construcció de la nau permetrà una zona d’alimentació i descans totalment coberta, una zona d’exercici parcialment coberta i una sala de preparació i magatzem dels productes necessaris. De la granja actual s’utilitzarà una quadre per infermeria i la resta per diferents necessitats com ara, magatzem palla, garatge tractor

Projecte d’una explotació bovina d’aptitud càrnia en règim extensiu a “ Can Gummà” de Cabanelles (Alt Empordà)

L’objectiu del projecte és determinar la viabilitat i el rendiment de la instauració d’una explotació bovina d’aptitud càrnia en règim extensiu, aconseguint uns bons nivells de producció i qualitat de la carn. Així mateix i com a complement a l’activitat prevista, es projecta la construcció d’un cobert agrícola de 300 m2 per a emmagatzemar palla i farratges. La finca “Mas Gummà” es troba situada dins terme municipal de Cabanelles, comarca de l’ Alt Empordà, província de Girona. Actualment es dedica a l’agricultura i a la producció ramadera. Pel que fa a la producció agrícola es dedica a la sembra de colza, blat i ordi amb l’objectiu de comercialitzar el gra. Referent a part ramadera es dedica a l’engreix de pocs i a la recria de gallines, en ambdós casos de forma integrada. La finca disposa de 111,23 hectàrees de bosc i de 88,34 hectàrees de terra, incloent la pròpia i l’arrendada

Efecte d'una estratègia de millora ambiental enfront l'estrès tèrmic en vaques Frisones

Aquest estudi descriu una possible millora ambiental, amb l'objectiu d’incrementar la producció lletera disminuint l’estrès tèrmic durant l’època d’estiu. Per portar a terme l’avaluació, es van utilitzar 142 vaques lleteres d’alta producció. Aquestes es van dividir en dos grups, el grup experimental (aplicació de l'estratègia ambiental) i grup control (no aplicació de l'estratègia ambiental).  

Enjoy your meal

Memoria del proyecto de la elaboración de una aplicación para el sistema operativo Android que permite organizar la alimentación de los usuarios mediante la planificación de las comidas.

Del plat al cervell

Per solucionar el sobrepés cal lluitar amb un model d'alimentació que és resultat de milions d'anys d'evolució instintiva i metabòlica

Vigilar les calories per poder mantenir el cervell jove

Els excessos a la taula també influeixen en els mecanismes que expliquen el desenvolupament de les malalties neurodegeneratives

Use of recovered frying oils in chicken and rabbit feeds: effect on the fatty acid and tocol composition and on the oxidation levels of meat, liver and plasma

The addition of some fat co- and by-products to feeds is usual nowadays; however, the regulations of their use are not always clear and vary between countries. For instance, the use of recycled cooking oils is not allowed in the European Union, but they are used in other countries. However, oils recovered from industrial frying processes could show satisfactory quality for this purpose. Here we studied the effects of including oils recovered from the frying industry in rabbit and chicken feeds (at 30 and 60 g/kg, respectively) on the fatty acid (FA) and tocol (tocopherol + tocotrienol) compositon of meat, liver and plasma, and on their oxidative stability. Three dietary treatments (replicated eight times) were compared: fresh non-used oil (LOX); oil discarded from the frying industry, having a high content of secondary oxidation compounds (HOX); and an intermediate level (MOX) obtained by mixing 50 : 50 of LOX and HOX. The FA composition of oil diets and tissues was assessed by GC, their tocol content by HPLC, the thiobarbituric acid value was used to assess tissue oxidation status, and the ferrous oxidation-xylenol orange method was used to assess the susceptibility of tissues to oxidation. Our results indicate that FA composition of rabbit and chicken meat, liver and plasma was scarcely altered by the addition of recovered frying oils to feed. Differences were encountered in the FA composition between species, which might be attributed mainly to differences in the FA digestion, absorption and metabolism between species, and to some physiological dietary factors (i.e. coprophagy in rabbits that involves fermentation with FA structure modification). The α-tocopherol (αT) content of tissues was reduced in response to the lower αT content in the recovered frying oil. Differences in the content of other tocols were encountered between chickens and rabbits, which might be attributable to the different tocol composition of their feeds, as well as to species differences in the digestion and metabolism of tocols. Tissue oxidation and susceptibility to oxidation were in general low and were not greatly affected by the degree of oxidation of the oil added to the feeds. The relative content of polyunsaturated fatty acids/αT in these types of samples would explain the differences observed between species in the susceptibility of each tissue to oxidation. According to our results, oils recovered from the frying industry could be useful for feed uses.