Search results for "69"
showing 10 items of 1106 documents
Utilization of muddy detritus as organic matter source by the fan mussel Pinna nobilis.
2014
The knowledge of the feeding habits in marine species is fundamental to better understand their relationship with the environment. Although phytoplankton has been traditionally reported as the main food source consumed by the Mediterranean fan mussel Pinna nobilis, recent studies have revealed that detritus represents an important food source for this species. We analysed the degree of acceptance of muddy detritus and the utilisation of its organic matter (OM) by P. nobilis on a group of 21 individuals (30.3-59.7 cm of total shell height (Ht)). The specimens were collected between July and September 2012 in two areas (43°04´25” N; 5°46´7” E and 43°04´34” N; 5°47´32” E) of the Embiez archipe…
Opportunistic Germination Behaviour of Gypsophila (Caryophyllaceae) in Two Priority Habitats from Semi-arid Mediterranean Steppes
2011
Gypsophila tomentosa and G. struthium are closely related species, characteristic of two European priority habitats, salt and gypsum inland steppes, respectively. Germination strategies of the two taxa were investigated in plants from two nearby populations, growing under the same climatic conditions but on different types of soil, and belonging to different plant communities. Their germination patterns were studied at five constant temperatures in darkness: 5oC, 10oC, 15oC, 20oC and 25oC, and the base temperature and the thermal time requirement were calculated. As the distribution area of both species is subjected to a Mediterranean continental climate with significant differences between…
Effects of traditional forest management on carbon storage in a Mediterranean holm oak (Quercus ilex L.) coppice
2018
Abstract: In the last decade, there has been increased interest in measuring and modeling storage in the five forest carbon pools: the aboveground and belowground biomass (living biomass), the deadwood and litter (dead biomass), and the soil (soil organic matter). In this paper, we examined carbon storage in a holm oak coppice stand in the Madonie Mountains in Sicily (Italy), which is a typical case of managed coppice stands. Today, traditional coppice practices are only applied to a small number of forested areas in Sicily, such as the selected site, because of the decline in demand for wood and charcoal. The dendrometric parameters of the stands were recorded, and silvicultural indices we…
Zonation by ammonites and foraminifers of the Vraconnian-Turonian interval: A comparison of the Boreal and Tethyan domains (NW Europe / Central Tunis…
2008
International audience; Since the end of the 19th century the interval comprising the uppermost Upper Albian, the Cenomamian, the Turonian and the basal Coniacian has been subdivided, first into ammonite zones, then, beginning in the middle of the 20th century, into zones of planktonic foraminifera. These two groups, one macrofossil, the other microfossil, are particularly effective for bio-chronostratigraphy thanks to their rapid rates of evolution. But differences in the faunal makeup between the Boreal domain (northwestern Europe) and the Tethyan domain (Mediterranean) have for a long time hindered precise correlation of the two domains. Today, in a time interval covering about 16 millio…
Stable C and N isotope concentration in several tissues of the loggerhead sea turtle Caretta caretta from the western Mediterranean and dietary impli…
2007
CONCENTRACIÓN DE ISÓTOPOS ESTABLES DE C Y N EN VARIOS TEJIDOS DE LA TORTUGA BOBA CARETTA CARETTA DEL MEDITERRÁNEO OCCIDENTAL E IMPLICACIONES SOBRE LA DIETA. – La concentración isotópica de escudos del caparazón, piel, músculo y sangre de tortuga boba (Caretta caretta) fueron analizados para investigar el patrón de variación entre tejidos y para evaluar la posición de esta especie en las redes tróficas de la cuenca Argelina. La piel presentaba valores más altos de δ13C que el músculo o los escudos del caparazón y éstos presentaban valores más altos que la sangre. En cambio, el músculo presentaba valores más altos de δ15N que la piel, ésta valores más altos que la sangre y ésta valores más al…
Effects of recreational scuba diving on Mediterranean fishes: evidence of involuntary feeding?
2013
Despite a large body of literature assessing the impacts of recreational scuba diving on marine habitats, little attention has been paid to the potentially harmful effects this has on fishes. The aim of this study was the assessment of the immediate response of different fish species to divers’ activities. A decrease of fishes’ natural diffidence towards divers is shown, probably due to an enhanced availability of their prey as a result of divers’ contacts with the substrate.
Merkels Briefwechsel
2018
Informācija par G. H. Merķeļa vēstuļu kolekciju Latvijas Universitātes Akadēmiskajā bibliotēkā
Brief an Karl Axel Christer Freiherr von Bruiningk
1839
Ms. 930a, Nr. 6b, Bl. 19r-19v Merkel, Garlieb H. Brief an Karl Axel Christer Freiherr von Bruiningk, [Depkinshof ?], [bez datuma; ohne Datum, pēc / nach 1839] Autora rokraksts / Autograph, vācu val. / Deutsch, [2] lpp. / S. Attēlu numuri / Bildnummern: 930a-006b-1 – 930a-006b-2 In dem undatierten Entwurf einer Antwort auf einen Brief Bruiningks [womit der unter Ms. 930a, Nr. 6a gemeint wird, bleibt noch unklar] lobt Merkel dessen Einsatz für die Bauernbefreiung. Das Problem des fehlenden Grundbesitzes für die freigelassenen Bauern sei ein Grund für die wirtschaftliche Rückständigkeit der „vaterländische[n] Provinzen“. Selbst in Posen (Preußen) und Galizien (Österreich) hätte die wirtschaftl…
Brief an Garlieb H. Merkel
1799
Ms. 930a, Nr. 18, Bl. 45r-46v Justus C. Loder. Brief an GarliebH. Merkel, Jena, den 19. Jul[i] 1799 Autora rokraksts / Autograph, vācuval. / Deutsch [2] lpp. / S. Attēlu numuri / Bildnummern: 930a-018-1, 930a-018-2 Der kurze Brief, der wahrscheinlich von Justus C. Loder stammt, hat vor allem zum Ziel, scheinbar erneut, Merkel einzuladen und die Verbundenheit mit ihm zum Ausdruck zu bringen.Loder, der zu diesem Zeitpunkt Professor für Medizin in Jena war, stammte aus Riga, woraus sich ein besonderes Verhältnis zu Livland und zum Adressaten entstammt haben könnte. Es ist naheliegend, dass Merkel während seines kurzen, aber nicht zu Ende geführten Medizinstudiums, das er in Leipzig begann und …
Miradas letradas, letras ad-miradas. Una conversación con el mundo social
2019
El presente texto plantea una aproximación al concepto de miradas le- tradas en contextos educativos utilizando como recurso expresivo la metáfora de la conversación. Las miradas letradas quedan caracterizadas como estrategias que bus- can reconfigurar nuevas formas de leer, conocer y expresar la realidad social.Tras esta caracterización, la discusión se centra en la necesidad de generar nuevos entor- nos de aprendizaje mediante espacios le- trados, que estimulen y sean favorables a la lectura y a la escritura. La conclusión sostiene que estos entornos requieren la transformación de las instituciones edu- cativas y culturales en lugares diferentes a los que hasta ahora resultaban hab…