Zonation and Associations of Dominant Fish Fauna on Flemish Cap

Data were obtained from 682 demersal trawls made between 126 and 738 m depths on Flemish Cap in summer during the European Union research surveys in the years 1989–94. Despite the fact that the depth range for all species was not completely covered, analysis of different deep distributions of the 25 most representative species showed that the fauna are zoned with depth. Three faunal assemblages with characteristic catch rates, diversity and dominant species were found on the shelf (126–300 m), upper continental slope (300– 600 m) and middle continental slope (>600 m). Catch rates were greatest on the shelf and upper continental slope, while diversity was greatest on the middle continental slope. Dominance of the commercial species Atlantic cod (Gadus morhua), golden redfish (Sebastes marinus) and American plaice (Hippoglossoides platessoides) on the shelf, beaked redfish (Sebastes mentella) and Labrador redfish (Sebastes fasciatus) on upper continental slope, and Greenland halibut (Reinhardtius hippoglossoides) on the middle continental slope. This showed an important aspect of the community structure. Diversity patterns may be understood in terms of the relationships with predation, competition, environmental heterogeneity and trophic level. Also the influence of the fisheries in the area can modify this structure. On the size-depth correlations, only longnose eel (Synaphobranchus kaupy), longfin hake (Urophycis chestery), Atlantic cod (Gadus morhua), beaked redfish (Sebastes mentella), golden redfish (Sebastes marinus) and Greenland halibut (Reinhardtius hippoglossoides) showed a significant 'bigger-deeper' relationship (i.e. larger fish in deeper strata), while spotted wolffish (Anarhichas minor) and witch flounder (Glyptocephalus cynoglossus) showed a negative 'smaller-deeper' relationship

Zonation and Associations of Dominant Fish Fauna in Flemish Cap

Data from 682 demersal traws between 126 and 738 m were made on Flemish Cap in summer during the research surveys in the years 1989-1994. Despite the fact that the depth range for all species was not completely covered, analysis of the vertical distribution of the 25 most representative species showed that the fauna is zoned with depth. Distinct faunal assemblages with characteristic catch rates, diversity, and dominant species are found on the shelf (126-300 m), upper continental slope (300-600 m) and middle continental slope (> 600 m). Catch rates are greatest on the shelf and upper continental slope, as while as diversity is greatest on the middle continental slope. Dominance of the commercial species (Cod, Redfish, American plaice, Greenland halibut) is an important aspect of the community structure. Diversity patterns may be understood in terms of the relationships with predation, competition, environmental heterogeneity, and trophic level. Also the influence of the fisheries in the area can modify this structure. Only Synaphobranchus kaupy, Sebastes marinus and Reinhardtius hippoglossoides showed a significant bigger-deeper relation, while Anarhichas minor and Glyptocephalus cynoglossus has a smaller-deeper relation

Volcanic Stratigraphy of Hannah Point, Livingston Island, South Shetland Islands, Antarctica

The Upper Cretaceous volcanic succession of Hannah Point is the best exposure of the Antarctic Peninsula Volcanic Group on Livingston Island. The aim of the present paper is to contribute to the characterisation of the stratigraphy and petrography of this little studied succession, and briefly discuss some aspects of the eruptive style of its volcanism. The succession is about 470 m thick and is here subdivided into five lithostratigraphic units (A to E from base to top). Unit A, approximately 120 m thick, is mainly composed of polymict clast-supported volcaniclastic breccias and also includes a dacitic lava laye r. Interstratified in the breccias of this unit, there is a thin laminated devitrified layer which shows some degree of welding. Unit B, approximately 70 m thick, is almost entirely composed of volcaniclastic breccias, and includes a volcaniclastic conglomerate layer. Breccias in this unit can be subdivided into two distinct types; polymict clast-supported breccias, and monomict matrix-supported breccias rich in juvenile components and displaying incipient welding. Unit C, about 65 m thick, is mainly composed of basaltic lavas, which are interlayered with minor volcaniclastic breccias. Unit D, approximately 65 m thick, is lithologically similar to unit B, composed of an alternation of polymict clasts upported breccias and matrix-supported breccias, and includes a volcaniclastic conglomerate layer. Unit E, about 150 m thick, is mainly formed of thick andesitic lava layers. Minor basaltic dykes and a few normal faults cut the succession, and the contact between units A and B can be interpreted both as an unconformity or a fault. The matrix-supported breccias included in the succession of Hannah Point have high contents of juvenile components and incipient welding, which suggest that part of the succession is the result of pyroclastic fragmentation and emplacement from pyroclastic flows. In contrast, the polymict clast-supported breccias suggest reworking of previous deposits and deposition from cool mass flows. The lavas indicate effusive volcanic eruptions, and the absence of features indicative of subaqueous volcanism suggests that at least these portions of the succession were emplaced in a subaerial environment

Mesozoic geology of Cape Shirreff, Livingston Island, South Shetland Islands, Antarctica

The stratigraphic succession at Cape Shirr e ff has a minimum thickness of 450 m and is mainly composed of lavas and a smaller amount of volcaniclastic breccias. Lavas are subalkaline olivine basalts and basaltic andesites which are locally well - bedded, but in most areas give a homogeneous, sometimes massive aspect to outcrops. Volcaniclastic massive breccias are found in the northern part of Cape Shirreff where they are interstratified with lavas in a few outcrops. Breccias are indurated, heterometric, grain - supported and consist of angular to subangular volcanic rock fragments, 5 to 80 cm in diameter. Petrographic evidence of magma supercooling (skeletal microlites of plagioclase, thermal - shocked phenocrysts of olivine) enables a subaqueous environment for part of the lavas to be deposited and suggests a possible hyaloclastic origin for some interstratified volcanic breccias. The whole succession is cut by subve rtical dykes (10 to 40 cm thick and a few meters to 400 m long), which show variable trends around a NW-SE maximum. These consist of commonly vesiculated basaltic and basaltic andesite porp hyritic rocks, commonly indistinguishable from the lava bodies. Lavas dip variably between 15 and 80º, more gently in the south than in the central and northern areas. Although significant variations in dipping attitude could be associated with depositional geometries, the general dipping pattern is clearly consistent with NW-SE oriented large-scale folds showing a gentle dome and basin structure. In the southern area, the NW-SE folds are not so well developed and the structure seems to be consistent with an interference of N-S and E-W oriented folds. The large scale NW-SE folds are consistent with NE-SW shortening. This shortening direction is parallel to the direction of extension deducible from dykes and, hence, folds and dykes are not consistent with the same deformational event

Vacuum Stability Higgs Mass Bound Revisited with Implications for Extra Dimension Theories

We take the standard model to be an effective theory including higher dimensional operators suppressed by scale $\Lambda$ and re-examine the higgs mass bounds from the requirements of vacuum stability. Our results show that the effects of the higher dimensional operators on the higgs mass limits are significant. As an implication of our results, we study the vacuum stability higgs mass bounds in theories with extra dimensions.Comment: Latex, 14 pages, 1 figure. Added references. To appear in Phys. Rev.

The feeding of Cod (Gadus morhua) on Flemish Cap, 1989-90

The food and feeding of Flemish Cap cod (Gadus morhua) in summer are described for 2 years, 1989 and 1990. The summer feeding intensity was high and the prey spectrum was narrow in both years. Hyperidea and redfish stood out in the diet of the Flemish Cap cod. Illex illecebrosus and polychaetes had a high annual variability. In the juvenile cod diet, invertebrates (crustaceans and polychaetes) were dominant and in the adults the most important prey were fish, mainly redfish. The Schoener overlap index was calculated to study the intraspecific diet overlap. It was noted that cod diet changed between age groups 3-5 and 6-10. Cannibalism rates showed year-to-year fluctuations. Ingestion of redfish was similar in both years and a direct relationship between cod length and the length of redfish they preyed on was noted

Efecto de pretratamientos desvulcanizantes y de aditivos en materiales compuestos con matriz de HDPE y neumáticos fuera de uso

La gestión de los neumáticos al final de su ciclo de vidaprecisa soluciones para potenciar su reutilización y reciclado.Un paso previo consiste en la pulverización de losneumáticos por parte de empresas especializadas. La incorporaciónde este granulado como refuerzo en matricestermoplásticas se ha propuesto como método de valorizacióndel polvo de neumático. Este sistema se ve limitadopor la incompatibilidad entre matriz y refuerzo. Recientemente,un nuevo polvo de neumático, denominado comercialmente “desvulcanizado” ha aparecido en el mercado.En este artículo se comparan materiales compuestosformulados con polvo de neumático desvulcanizado conlos obtenidos con el mismo material sin tratamiento enmatriz de polietileno de alta densidad. También se estudiael efecto de distintos métodos de mezclado, del uso deaditivos dispersantes y del tamaño de partícula

Diapiro de Salinas de Añana: ¿un diapiro con un Overhang? Modelo 3D grav¡mético

A new gravity map of the Cubeta Alavesa has been compliled and interpreted. In this map the gravity lows produced by the outcropping evaporitic diapirs and other deeper structures are very well depicted. The gravity low of the Salinas de Añana diapir has been modelled using two different 3D methods. The density model obtained has a great extension at surface but not in depth, given a lateral extension or overghang dipping to the SW.Se presenta el mapa gravimétrico de la Cubeta Alavesa, donde se pueden localizar de forma clara los diapiros salinos aflorantes en la misma, y también otras estructuras también diapíricas situadas a mayor profundidad. Se ha modelizado en 3D, mediante dos técnicas gravimétricas diferentes, el diapiro de Salinas de Añana. El cual presenta una gran extensión en superficie pero que en cambio no se proyecta de la misma manera en profundidad, habiéndose detectado la presencia de una extensión lateral u overghang hacia el SW

Vacuum Stability, Perturbativity, and Scalar Singlet Dark Matter

We analyze the one-loop vacuum stability and perturbativity bounds on a singlet extension of the Standard Model (SM) scalar sector containing a scalar dark matter candidate. We show that the presence of the singlet-doublet quartic interaction relaxes the vacuum stability lower bound on the SM Higgs mass as a function of the cutoff and lowers the corresponding upper bound based on perturbativity considerations. We also find that vacuum stability requirements may place a lower bound on the singlet dark matter mass for given singlet quartic self coupling, leading to restrictions on the parameter space consistent with the observed relic density. We argue that discovery of a light singlet scalar dark matter particle could provide indirect information on the singlet quartic self-coupling.Comment: 25 pages, 10 figures; v2 - fixed minor typos; v3 - added to text discussions of other references, changed coloring of figures for easier black and white viewin