Producción secundaria de artrópodos estimada mediante trampas de emergencia en dos bosques del Montseny (Barcelona)

Part of the secondary production was evaluated in a montane holm-oak wood and a beechwood in the Montseny mountains. The production estimates of emergent adults were necessarily underestimates, since the mortality of immature forms was not taken into account. Most part of the emergent adults were Diptera (60 % and 72 % of total emerged individuals in the holm-oak and beech forests, respectively) and Hymenoptera (8 %) in both forests. Secondary production between May 1981 and June 1982 was estimated as 11,2,10 6 individuals/ha/year and 3.7 kg/ha/year in the holm-oak wood, and as 5.8 10 6 individuals/ha/year and 7.2 kg/ha/year in the beechwood. The most abundant families of Diptera were Cecidomyiidae, Sciaridae, Mycetophilidae and Chironomidae in the holm-oak forest; and Cedidomyiidae, Sciaridae and Empididae in the beech forest. Most of te biomass emerges during the summer under beech, and during the spring and the end of summer under holm-oak. It was estimated that the arthropods captured in emergence traps consume 288 kglhalyear of vegetable matter in the holm-oak site and 489 kg/ha[year in the beech sile (286 kgthalyear if Bibionidae are excluded). This consumption rate amounts to 5.5 % of the annual litterfall contribution in the holm-oak forest and between 6.6 % and 11.3 % in the beech forest.Se ha estimado una parte de la producción secundaria de artrópodos en un encinar montano y un hayedo del Montseny. Las estimaciones de la producción de adultos emergentes son necesariamente estimaciones por defecto puesto que no tienen en cuenta la mortalidad de las formas inmaduras. La mayor parte de 10s adultos emergentes son dipteros (60 % y 72 % en el encinar y el hayedo, respectivamente) e himenópteros (e1 8 %). La producción secundaria entre mayo de 1981 y junio de 1982 se estima en 11.2 10 6 individuos/ha/año y 3.7 kg/ha/año en el encinar, y en 5.8 106 individuos/ha/año y 7.2 kg/ha/año en el hayedo. Las familias de dipteros más abundantes son: En el encinar: Cecidomyiidae, Sciaridae, Mycetophilidae y Chironomidae. Y en el hayedo: Cecidomyiidae, Sciaridae y Empididae. La fenologia de emergencia indica que la mayor parte de la biomasa emerge en verano en el hayedo y en primavera y finales de verano en el encinar. Se ha estimado que a 10s artrópodos capturados con las trampas de emergencia les corresponde un consumo de materia vegetal de 288 kg/ha/año en el encinar y de 489 kg/ha/año en el hayedo (de 286 kg/ha/año sin los bibiónidos). Este consumo representa e1 5,5% % del peso seco del desfronde anual de encinar y entre el 6.6 % y 11.3 % del hayedo

Contribució al coneixement de la Coleopterofauna de la Vall de Sant Medir (Barcelona)

Hom comenta les característiques generals de la coleopterofauna de la vall de S. Medir (Barcelona) a partir d'un conjunt de mostreigs duts a terme al llarg de tots els mesos de l'any 1977. S'inclou una llista faunística de 101 espècies pertanyents a 23 famílies de coleòpters, d'on un 50% són de règim fitòfag. Es descriu el ritme estacional d'aquesta entomofauna, aixi com la distribució espacial de les espècies a la vall i la seva relació amb la vegetació

Adición a las hormigas (Hymenoptera, Formicidae) del Montseny (Barcelona)

Pitfall trapping in three biotopes added five species (Myrmica specioides, M. schencki, Lasius alienus, L. distinguendus and Camponotus ligniperdus) to the list of ants known from the Montseny (Barcelona. Spain), now totalling 46 species. The myrmecological community of the heathland is similar to other European heathland ant communities. Inseminated females of Myrmica specioides have been recovered from april to september, well out from its usual swarming dates.El estudio de tres biotopos por medio de trampas Barber (pitfall) ha permitido añadir cinco especies de hormigas al inventario del Montseny (Myrmica specioides, M. schencki, Lasius alienus, L. distinguendus y Camponotus ligniperdus) con lo que se eleva a 46 el número de species. Este número debe ser considerado provisional. La composición faunística de la landa muestreada no difiere sensiblemente de la de otras landas europeas. Se ha detectado la presencia fuera del nido (de abril a septiembre) de hembras fecundadas de Myrmica specioides fuera de su época normal de enjambrazón

Ocupació de Pinus Silvestris L., per IPS Acuminatus Gyll. (Col. Scolyt)

S'estudien sis arbres joves total i exclusivament ocupats per Ips aeuminatus Gyll., talats a la Vall de Roncal (Navarra) l'estiu de 1.979. Tots els arbres es trobaven en el mateix moment d'atac, essent l'ocupació dels troncs diferent depenent més de l'arbre que de l'escolítid. El nombre de femelles gairebé triplica el de mascles, fet que no concorda amb la igualtat que es dóna en el moment de la posta. Creiem que és degut a una sortida diferenciada en el temps que fa sortir primer els mascles. La densitat d'ocupació augmenta amb l'alçada de l'arbre considerat fins un punt en el que pràcticament s'estabilitza al voltant de 0,24 individus per centímetre quadrat

Usurpación de nidos de quebrantahuesos (Gypaetus barbatus) e interacciones interespecíficas por la ocupación del nido en el Pirineo central (Aragón)

El quebrantahuesos es una especie catalogada como “en peligro de extinción” en Europa, cuya fracción reproductora en los Pirineos se ha estimado en 125 unidades reproductoras (UR). En el Pirineo central (Aragón) en los últimos 15 años se ha producido un incremento de la población reproductora acompañado de un progresivo descenso de la productividad cuyas causas son objeto de discusión y pueden deberse a diversos factores. El periodo de reproducción del quebrantahuesos es muy extenso y coincide con el de otras rapaces que compiten por los emplazamientos de los nidos. Esto implica una importante inversión de tiempo y energía, por lo que la usurpación de nidos podría tener efectos negativos sobre el éxito reproductor. En Aragón entre 2005 y 2010 fueron usurpados 107 nidos de quebrantahuesos pertenecientes a 52 de las 72 UR controladas. La mayor parte de los nidos (95,3% de los casos; n = 102) fueron usurpados por buitre leonado (Gyps fulvus), aunque también por alimoche común (Neophron percnopterus) (4,7% de los casos; n = 5). El Pirineo Axial acogió tanto el mayor porcentaje de UR con nidos usurpados como la UR con un mayor número de nidos usurpados. No se encontraron diferencias significativas en cuanto a la productividad entre UR que habían sufrido usurpación y los que no la habían padecido. El buitre leonado posee una similar distribución espacial y parecidos requerimientos ecológicos al quebrantahuesos, mayor corpulencia y agresividad así como similar fenología de puesta temprana. El aumento demográfico del buitre leonado en Aragón podría estar provocando una mayor usurpación de nidos de quebrantahuesos en los Pirineos.El presente trabajo se ha elaborado dentro del Convenio Marco de Colaboración suscrito entre el Gobierno de Aragón y la FCQ (2008-2011), por el cual se desarrollaron diferentes acciones del Plan de Recuperación del quebrantahuesos en Aragón (D. 45/2003). Pascual López-López disfruta de una beca postdoctoral del programa “Juan de la Cierva” del Ministerio de Economía y Competitividad (referencia JCI-2011-09588)

Double fossilization in eukaryotic microorganisms from Lower Cretaceous amber

<p>Abstract</p> <p>Background</p> <p>Microfossils are not only useful for elucidating biological macro- and microevolution but also the biogeochemical history of our planet. Pyritization is the most important and extensive mode of preservation of animals and especially of plants. Entrapping in amber, a fossilized resin, is considered an alternative mode of biological preservation. For the first time, the internal organization of 114-million-year-old microfossils entrapped in Lower Cretaceous amber is described and analyzed, using adapted scanning electron microscopy in backscattered electron mode in association with energy dispersive X-ray spectroscopy microanalysis. Double fossilization of several protists included in diverse taxonomical groups and some vegetal debris is described and analyzed.</p> <p>Results</p> <p>In protists without an exoskeleton or shell (ciliates, naked amoebae, flagellates), determinate structures, including the nuclei, surface envelopes (cortex or cytoplasmic membrane) and hyaloplasm are the main sites of pyritization. In protists with a biomineralized skeleton (diatoms), silicon was replaced by pyrite. Permineralization was the main mode of pyritization. Framboidal, subhedral and microcrystalline are the predominant pyrite textures detected in the cells. Abundant pyritized vegetal debris have also been found inside the amber nuggets and the surrounding sediments. This vegetal debris usually contained numerous pyrite framboids and very densely packed polycrystalline pyrite formations infilled with different elements of the secondary xylem.</p> <p>Conclusion</p> <p>Embedding in amber and pyritization are not always alternative modes of biological preservation during geological times, but double fossilization is possible under certain environmental conditions. Pyritization in protists shows a quite different pattern with regard to plants, due to the different composition and cellular architecture in these microorganisms and organisms. Anaerobic sulphate-reducing bacteria could play a crucial role in this microbial fossilization.</p

Spatio-seasonal modeling of the incidence rate of malaria in Mozambique

<p>Abstract</p> <p>Background</p> <p>The objective was to study the seasonal effect on the spatial distribution of the incidence of malaria in children under 10 years old living in the Manhiça district, Mozambique.</p> <p>Methods</p> <p>The data of the clinical malaria incidence were obtained from a study of two cohorts of children followed from December 1996 to July 1999. The cases were obtained by the active detection method. Hierarchical Bayesian models were used to model the incidence of malaria, including spatial correlation nested to climatic season. The models were compared with the deviance information criterion. The age and gender of the children were also taken into account.</p> <p>Results</p> <p>The incidence of malaria is associated with age, period and climate season. The incidence presents a clear spatial pattern, with a higher incidence in the neighbourhoods situated in the north and northeast of the Manhiça area. The transmission of malaria is highest during the wet season but the spatial pattern of malaria does not differ from that during the dry season.</p> <p>Conclusion</p> <p>The incidence of malaria in Manhiça presents a spatial pattern which is independent of the seasonal climatic conditions. The climate modifies the incidence of malaria in the entire region but does not change the spatial pattern of the incidence of this disease. These findings may be useful for the planning of malaria control activities. These activities can be performed taking account that the neighbourhoods with more incidence of malaria do not change over the annual climate seasons.</p

Synthesis and processing of thionin precursors in developing endosperm from barley (Hordeum vulgare)

Thionin is a lysine-rich polypeptide (mol. wt. 5000) which is synthesized in developing barley endosperm from - 8 days to - 30 days after anthesis. Two thionin precursors (THPl and THP2) have been identified using monospecific antibodies (A-TH) prepared against the mature protein. THPl, which is the only polypeptide recognized in vitro by A-TH, is encoded by a 7.5S mRNA obtained from membrane-bound polysomes, and its alkylated derivative has an apparent mol. wt. of 17 800. THP2, which is selected together with mature thionin by A-TH among labelled proteins in vivo, differs from THPl in apparent mol. wt. (17 400 alkylated) and in electrophoretic mobility at pH 3.2. Both THPl and THP2 are competed out of the antigen-antibody complex by purified thionin. The conversión of THP2 into thionin, which has been demonstrated in a pulse-chase experiment in vivo, is a post-translational process. As it has not been possible to detect THPl in vivo it is assumed that it is converted cotranslationally into THP2. Final deposition of thionin as an extrínsic membrane protein, possibly associated with the endoplasmic reticulum, has been tentatively established on the basis of subcellular fractionation experíments

Cloning and nucleotide sequence of a cDNA encoding the precursor of the barley toxin a-hordothionin

A cDNA library, prepared from developing barley endosperm, was screened for thionin recombinants. Clone pTH1 was that with the largest insert out of three identified. The longest reading frame in the 610-base-pair insert codes for a protein of 127 amino acids that includes an internal sequence of 45 amino acids, which is identical to that obtained for the α-hordothionin by direct protein sequencing. The deduced thionin sequence is preceded by a leader sequence of 18 residues and followed by a sequence that corresponds to an acidic protein of 64 amino acids. This structure supports previous evidence indicating that thionin is synthesized as a much larger precursor, which undergoes two processing steps: the cotranslational cleavage of a leader sequence and the post-translational one of a larger peptide. The size of the mRNA was estimated to be about 950 bases by Northern analysis. Thionin concentration in mature endosperm of barley cv. Bomi was about twice that of its high-lysine mutant Risç 1508. The same difference was observed in thionin mRNA in the corresponding developing endosperms, indicating that gene expression is partially blocked in the mutant at a pretranslational leve