Correlation of atmospheric occurences over the United States with some physical and chemical parameters. Part III: Frequencies of precipitation

Summary Correlation between some physical and chemical variables, measured at 28 stations of the United States Weather Bureau Network, and seasonal and annual frequencies of precipitation, has been attempted with the aim of gaining insight into the bearing of such variables, on occurrence of precipitation. — Concurrent trends of frequencies with local temperature functions, altitude parameters, precipitable water vapour increments, and some chemical species have been found.Contribution of the «Centro Nucleazione Aerosoli» of the National Research Council of Italy, Via Vettore 4 (Monte Sacro),Roma.     

New remains of Eremotherium laurillardi (Lund, 1842) (Megatheriidae, Xenarthra) from the coastal region of Ecuador

New remains of Eremotherium were recovered from the Pacific coast of Ecuador’s Manabi province. The Machalilla fossiliferous locality records the northernmost presence of Eremotherium along the Pacific coast of South America. Most of the fossil remains belong to the same individual, mainly its posterior half, but other individuals are represented. Among the better-preserved specimens are skull fragments, most of the hind limb bones and a number of trunk and caudal centra. These remains were compared with samples collected during the 20th century along the southern coastal regions of Ecuador and northern Peru. Many characters of the long bones and tarsals testify to a possibly different lineage despite the closeness of other Eremotherium populations. Some metric and morphological aspects suggest a different space-temporal southern Caribbean provenance. Other Eremotherium specimens, coming from other Ecuadorian localities, were studied and compared with classic Eremotherium samples. Interesting morpho-functional aspects are pointed out with regard to the tail and its importance in the bipedal stance.     

Correlation of precipitable water vapour values over the united states with physical and chemical parameters. Part III: Annual and seasonal trends,a further approximation

Summary Deviations from a law previously established, which correlates the precipitable water vapour values in a vertical column of air over a measuring station with the latter's temperature and altitude, are reduced by multiple regression analysis, and implications are discussed.Contribution of the «Centro Nucleazione Aerosoli» of the National Research Council of Italy, Via Vettore 4 (Monte Sacro)Roma.     

On the preferential electrification of some dusts Part II: Release of gas from monodisperse powders of porous alumina,following adsorption of nitrous oxide

Summary Rates of release of nitrous oxide, from monodisperse fractions of activated alumina, are measured at room temperature and atmospheric pressure. The values obtained follow a simple first-order law with respect to the gas adsorbed, the relative parameters depending strongly on the size of the particulates examined (5 to 50 micron).     

Gastric Evacuation in the Juveniles of two Flatfish from a Western Mediterranean Bay

Abstract. The gastric evacuation (at 11 ^oC and 19 ^oC) and the relation between prey size and fish size of juveniles of Buglossidium luteum and Arnoglossus thori (Pisces, Heterosomata) are studied. The fish were collected at 20 m depth in the Banyuls Bay (France, Western Mediterranean). B. luteum showed a very rapid evacuation rate at 19 ^oC (2h to 4h for a IgDW meal) and a slower one at 11^oC (9h 30min for a IgDW meal). A. thori showed similar rates at both temperatures (6h 20min to 7 h 30 min for a IgDW meal). The relationship between prey size and predator size showed that A. thori always took larger prey than B. luteum. The diet of the latter changes only slightly with the increasing size of the fish. In contrast, the diet of A. thori changes more rapidly towards larger prey. A hypothesis explaining the contradictory evidence concerning the effect of fish and meal size on gastric evacuation is proposed.     

Core Jamming in Unconsolidated Formations

Geotechnical and Geological Engineering - In coring operations, core jamming is a permanent concern, taking place when the rock core sample becomes stuck within the inner core barrel, thus...     

Correlation of precipitable water vapour values over the United States with physical and chemical parameters Part II: Seasonal trends with physical variables

Summary Reitan's data on precipitable water vapour over about 45 stations of the U.S.W.B. network are correlated with altitude and average station temperature values. Computations are carried out following a simple proposed model which is found to be obeyed with reasonably good approximation on average monthly and seasonal scales.Contribution of the Centro-Nucleazione Aerosoli of the National Research Council of Italy,Rome, Via Vettore 4.     

A multimetric-index approach using fisheries data to assess fish assemblage structure in relation to salinity gradient in a tropical West African estuary

This study examines the effects of increasing salinity on fish assemblage structure in the Casamance Estuary, Senegal, using a series of indices. The study data were derived from commercial fishery surveys conducted between April and July 2005. Analysis of within-trophic-group diversity in the Casamance Estuary shows a significant drop in the diversity of apex predators in the upper, more saline reaches of the estuary. By contrast, primary consumers adapted well to salinity changes and exhibited higher taxonomic diversity in the upper reaches of the estuary than in the lower reaches. The findings also indicate decreases in average sizes of the landed species and the trophic levels among fish catches in the direction of the upper reaches. However, the catch per unit effort (CPUE) was globally higher in the upstream area of the estuary as compared with the downstream area. This increasing CPUE trend from the lower towards the upper reaches is attributed to (i) the high primary productivity in the upper Casamance Estuary; (ii) the increasing abundance of euryhaline fish species in an upstream direction; and (iii) ‘telescoping’ of the food chain through the presence of mostly herbivorous fishes in the upper reaches. Such a situation likely facilitated high fish production in the upstream area of the estuary, though multimetric indices indicated unfavourable living conditions for many fish taxa in this area.     

Changes over a decade in fish assemblages exposed to both environmental and fishing constraints in the Sine Saloum estuary (Senegal)

To investigate the changes in the fish assemblage of the Sine Saloum estuary (Senegal) over a 10-year period, it was surveyed during a complete hydrological cycle (three principal hydro-climatic seasons) first in 1992 and then in 2002–2003. The sampling protocol for the two surveys was identical, using the same sampling technique, the same collection periods, and the same sampling stations.