Respuesta de encinas truferas y micelio de Tuber melanosporum a varios tratamientos de control herbáceo

La tòfona negra (Tuber melanosporum Vittad.) és molt apreciada gastronòmicament, pel que la seva activitat recol·lectora al bosc és molt comú. Actualment, la disminució de la producció silvestre ha fet que augmentin les plantacions per a la seva producció. L'entrada en producció és variable, i depèn del maneig de la plantació. La competència herbàcia és un factor rellevant per a la supervivència i desenvolupament dels plançons. En aquest treball s'ha estudiat l'efecte de vuit tractaments de control herbaci sobre la coberta herbàcia, el creixement de les alzines, la quantitat de PAR i el miceli de T. melanosporum, aquest últim mitjançant l'extracció de l'ADN del sòl i la posterior amplificació de regions específiques amb la tècnica PCR.

Estrategias de muestreo de micorrizas para encinas y avellanos jóvenes inoculados con Tuber melanosporum Vittad

La reforestació en marcs regulars de plantació per a la producció de tòfona negra és un recurs d’una gran importància econòmica per zones amb sòl poc fèrtils. Les primeres produccions de tòfona negra en condicions adequades solen aparèixer entre els sis i deu anys. Conèixer l’estat del fong productor de la tòfona negra abans de la fase de producció pot ser un gran ajut en la presa de decisions de gestió. Tanmateix, per a la correcta presa de postres i la seva posterior inferència sobre l’estat del fong, es necessari conèixer la distribució en l’espai de les micorizes del fong. En aquest treball es presenten els resultats de tres tècniques de mostreig que es comparen amb la població total, així com la distribució en l’espai de les micorizes en avellaner i alzina.

Comparison of fatty acid profiles of edible meat, adipose tissues and muscles between cocks and capons

The effect of caponisation on fat composition by parts (wing, breast, thigh, and drumstick) and tissues (skin, subcutaneous adipose tissue, intermuscular adipose tissue and muscle) was examined in the present study and fatty acid profiles of abdominal fat and edible meat by parts and tissue components were determined. The sample was made up of twenty-eight castrated and twenty male Penedesenca Negra chicks reared under free-range conditions and slaughtered at 28 wk of age; the birds were castrated at four or eight weeks. Caponisation significantly increased (P < 0.01) the chemical fat content in all parts (16.31% to 37.98% in breast; 21.98% to 34.13% in wing; 21.09% to 49.57% in thigh; 14.33% to 24.82% in drumstick) and led to minor modifications in fat haracteristics, particularly in the thigh and the drumstick, where the unsaturated vs. saturated fatty acid ratio increased from 1.31 to 1.76 ( P < 0.01) and from 1.48 to 2.07 (P < 0.01), respectively. Delaying the age of castration from 4 to 8 weeks increased this ratio by 0.35 in the edible meat. Even though the profile of the abdominal fat is less saturated in capons, all changes occurring on fat quality after caponisation indicate that increased fatness after castration does not imply worse fat nutritional properties.

Comparison of carcass composition by parts and tissues between cocks and capons

The effect of caponisation on carcass composition by parts and tissues was examined. Twenty-eight castrated and twenty male Penedesenca Negra chicks reared under free-range conditions were slaughtered at 28 weeks of age. The birds were castrated at 4 or 8 weeks. The left sides of the carcasses were quartered (wing, breast, thigh and drumstick), and the parts dissected into the tissue components (skin, subcutaneous fat, intermuscular fat, muscle, bone and tendons). Capons showed more abdominal, intermuscular and subcutaneous fat than the cocks, both at the same slaughter age and at the same weight. The breast and thigh were heavier in the capons than in the cocks. However, the whole muscle mass in the breast was increased by caponisation. This favourable effect was achieved at the expense of decreasing the carcass yield. The age of castration up to 8 weeks did not affect the carcass composition of the parts and tissues.

Aportación de la truficultura al desarrollo socioeconómico: resultados de los estudios realizados en el municipio de Sarrión (Teruel)

La trufa negra aparece de forma silvestre entre otros lugares en la Sierra de Javalambre (Teruel), donde desde hace 15 años se han establecido plantaciones de trufa con la intención de cultivar este "tesoro culinario". La información extraída de este estudio, basado en encuestas realizadas a personas vinculadas al cultivo de la trufa en esta Región, tiene como objetivo estimar el impacto socioeconómico de este cultivo en ciertas regiones,comparando su beneficio con los cultivos tradicionales de estas zonas.

Meat characteristics of chickens from an F1 cross of two improved Spanish breeds depending on slaughter age

The present study analysed the meat characteristics of i) improved Castellana Negra chickens slaughtered at 18 weeks (CN-18) and ii) F1 crossbred chickens from improved Castellana Negra hens and improved Penedesenca Negra cocks (CNPN) slaughtered at 12 weeks and 18 weeks of age (young and adult animals, respectively). Purebred and crossbred specimens were compared at similar weights (CN-18 and CNPN-12) and ages (CN-18 and CNPN-18). The protein content of the meat was similar for the three types of animals; heavier animals (CNPN-18) had more fat than those slaughtered at lower weights (CNPN-12 and CN-18). Adults had a higher saturated fatty acid content and the young CNPN chickens had more monounsaturated fatty acids than CN chickens. In the CNPN adults, less water was lost during cooking, which is directly related to the juiciness of the meat. With regard to sensory analysis, a darker colour was observed in the meat as much as the internal fat of adult animals, in addition to greater colour uniformity. The meat of young CNPN birds was juicier, whereas that of the CN chickens was more fibrous. Therefore, we conclude that meat from CNPN chickens presents chemical, physical, and sensorial characteristics that make these animals a genetic base for alternative poultry production.

Stenbergia colchiciflora Waldst. & Kit. en el Valle del Ebro.

Especie nueva para la flora catalano-aragonesa, encontrada en la Serreta Negra de Fraga y en la Valcuerna de Candasnos. Esta planta de origen póntico mediterráneo, debe añadirse a la lista de especies esteparias del Mediterráneo Oriental que se refugian en el Vedat de Fraga (O. DE BOLOS, Mem. Real Acad, Barcelona 42, n.° 6. 1973)

Discursos sobre la naturaleza americana: desde el descubrimiento de América hasta la visión ilustrada.

Los siglos del descubrimiento y la conquista parten de una visión providencialista de la historia que incide directamente en el concepto de la naturaleza americana. De este concepto derivan algunas características básicas de la escritura historiográfica de la época. A partir del siglo XVIII desaparece el concepto místico-geográfico que el cristianismo había dado a la geografía. Con respecto a la naturaleza americana, durante el siglo XVIII tanto los naturalistas como los historiadores y los filósofos pretendieron estudiarla partiendo de premisas consideradas más objetivas y como consecuencia de la sistematización del conocimiento. Todo ello repercutirá en el descrédito que sufrirán las crónicas de Indias. Sin embargo, esta nueva manera de leer las crónicas de Indias guarda relación no tan sólo con la búsqueda de formas alternativas de pruebas históricas o el uso de nuevos tipos de pruebas más fidedignas, sino también con determinados intereses políticos y la creación de la leyenda negra.

Timing and nature of alluvial fan and strath terrace formation in the Eastern Precordillera of Argentina

Sixty-eight 10Be terrestrial cosmogenic nuclide (TCN) surface exposure ages are presented to define the timing of alluvial fan and strath terrace formation in the hyper-arid San Juan region of the Argentine Precordillera. This region is tectonically active, and numerous fault scarps traverse Quaternary landforms. The three study sites, Marquesado strath complex, Loma Negra alluvial fan and Carpintería strath complex reveal a history of alluvial fan and strath terrace development over the past w225 ka. The Marquesado complex Q3m surface dates to w17 3 ka, whereas the Loma Negra Q1ln, Q2ln, Q3ln, Q4ln, and Q5ln surfaces date to w24 3 ka, w48 2 ka, w65 13 ka, w105 21 ka, and w181 29 ka, respectively. The Carpintería complex comprises eight surfaces that have been dated and include the Q1c (w23 3 ka), Q2c (w5 5 ka), Q3ac (w25 12 ka), Q3bc (w29 15 ka), Q4c (w61 12 ka), Q5c (w98 18 ka), Q6c (w93 18 ka), and Q7c (w212 37 ka). 10Be TCN depth profile data for the Loma Negra alluvial fan complex and Carpintería strath terrace complex, as well as OSL ages on some Carpintería deposits, aid in refining surface ages for comparison with local and global climate proxies, and additionally offer insights into inheritance and erosion rate values for TCNs (w10 104 10Be atoms/g of SiO2 and w5 m Ma 1, respectively). Comparison with other alluvial fan studies in the region show that less dynamic and older preserved surfaces occur in the Carpintería and Loma Negra areas with only younger alluvial fan surfaces preserved both to the north and south. These data in combination with that of other studies illustrate broad regional agreement between alluvial fan and strath terrace ages, which suggests that climate is the dominant forcing agent in the timing of terrace formation in this region.

Noves dades de l'activitat dels Jueus de Vic al Cabrerès (1345-1348)

L’estudi del Registre de la Cúria del Cabrerès aporta noves dades per conèixer l’activitat de la comunitat jueva de Vic en aquesta zona a l’època de la Pesta Negra, complementant les dades de l’últim llibre de la sèrie de Libri iudeorum conservats a l’Arxiu Episcopal de Vic