23 resultados para Serological survey in equines
em Publishing Network for Geoscientific
Resumo:
The Kara scientific expedition of 1945, using the fishing trawler M. Gorkiy and survey vessel Osetr, took sediment samples in the Kara Sea in addition to other oceanographic work. The investigations of sediments composition was compared with biological and hydrological data obtained in the same areas. The sediments sampled were subjected to mechanical, mineralogical, chemical and faunistic analyses. During this survey iron-manganese concretions were recovered.
Resumo:
While summer Arctic sea-ice extent has decreased over the past three decades, it is subject to large interannual and regional variations. Methodological challenges in measuring ice thickness continue to hamper our understanding of the response of the ice-thickness distribution to recent change, limiting the ability to forecast sea-ice change over the next decade. We present results from a 2400 km long pan-Arctic airborne electromagnetic (EM) ice thickness survey in April 2009, the first-ever large-scale EM thickness dataset obtained by fixed-wing aircraft over key regions of old ice in the Arctic Ocean between Svalbard and Alaska. The data provide detailed insight into ice thickness distributions characteristic for the different regions. Comparison with previous EM surveys shows that modal thicknesses of old ice had changed little since 2007, and remained within the expected range of natural variability.
Data collection of Calanus finmarchicus reproduction life history traits in the North Atlantic Ocean
Resumo:
Observations of egg production rates (EPR) for female Calanus finmarchicus were compared from different regions of the North Atlantic. The regions were diverse in size and sampling frequency, ranging from a fixed time series station in the Lower St Lawrence Estuary, off Rimouski, where nearly 200 experiments were carried out between May and December from 1994 to 2006, to a large-scale survey in the Northern Norwegian Sea, where about 50 experiments were carried out between April and June from 2002 to 2004. For this analysis the stations were grouped mostly along geographic lines, with only limited attention being paid to oceanographic features. There is some overlap between regions, however, where stations were sometimes kept together when they were sampled on the same cruise. As well some stations other than off Rimouski were occupied more than once during different years and/or in different seasons.
Resumo:
Am Mittelatlantischen Rücken befinden sich zahlreiche intermontane Sedimentbecken. Ein solches 8 x 14 km großes und bereits im Rahmen der internationalen Bohrprogramme ODP und DSDP mehrmals beprobtes und untersuchtes Sedimentbecken ist "North Pond". In Februar und März 2009 wurde erstmals ein umfassender Parasound-Survey in "North Pond" durchgeführt. Parasound-Daten werden zur Untersuchung oberflächennaher Sedimentstrukturen genutzt. Dabei können kleinskalige Rutschungen, Störungen und Sedimentabfolgen abgebildet werden, die mit niederfrequenterer Seismik nicht erkannt werden können.
Resumo:
The numbers and distributions of Peary caribou (Rangiier tarandus pearyi) on western Queen Elizabeth Islands, Northwest Territories were determined by aerial surveys based on a standard census strip method. Surveys were flown in March-April and July-August periods in 1972, 1973, and 1974. Comparison of the 1973 and 1974 survevs with those results of a comparable survey in 1961 showed an overall decline of 89% in numbers of caribou between 1961 and 1974. Percentage reduction of caribou numbers from 1961 to 1874 followed a west-cast gradient on the three major islands: Prince Patrick 72%, Melville 87% , and Bathurst 92%. The marked decrease in numbers of caribou is attributed to a combination of high winter mortality in some years and an overall low rate of births and recruitment from 1961 to 1974.
Resumo:
Two medium-depth ice cores were retrieved from Berkner Island by a joint project between the Alfred-Wegener-Institut and the British Antarctic Survey in the 1994/95 field season. A 151m deep core from the northern dome (Reinwarthhöhe) of Berkner Island spans 700 years, while a 181m deep core from the southern dome (Thyssenhöhe) spans approximately 1200 years. Both cores display clear seasonal cycles in electrical conductivity measurements, allowing dating by annual-layer counting and the calculation of accumulation profiles. Stable-isotope measurements (both d18O and dD), together with the accumulation data, allow us to estimate changes in climate for most of the past millennium: the data show multi-decadal variability around a generally stable long-term mean. In addition, a full suite of major chemistry measurements is available to define the history of aerosol deposition at these sites: again, there is little evidence that the chemistry of the sites has changed over the past six centuries. Finally, we suggest that the southern dome, with an ice thickness of 950 m, is an ideal site from which to gain a climate history of the late stages of the last glacial and the deglaciation for comparison with the records from the deep Antarctic ice cores, and with other intermediate-depth cores such asTaylor Dome and Siple Dome.
Resumo:
A 5-year sediment trap survey in the upwelling area off Cape Blanc (NW Africa) provides information on the seasonal and annual resting cyst production of dinoflagellates, their sinking characteristics and preservation potential. Strong annual variation in cyst production characterizes the region. Cyst production of generally all investigated species, including Alexandrium pseudogonyaulax (Biecheler) T. Horig. ex T. Kita et Fukuyo (cyst genus Impagidinium) and Gonyaulax spinifera (Clap. et J. Lachm.) Diesing (cyst genus Nematosphaeropsis) was enhanced with increasing upper water nutrient and trace-element concentrations. Cyst production of Lingulodinium polyedrum (F. Stein) J. D. Dodge was the highest at the transition between upwelling and upwelling-relaxation. Cyst production of Protoperidinium americanum (Gran et Braarud) Balech, Protoperidinium monospinum (Paulsen) K. A. F. Zonn. et B. Dale, and Protoperidinium stellatum (D. Wall) Balech, and heterotrophic dinoflagellates forming Brigantedinium spp. and Echinidinium aculeatum Zonn., increased most pronouncedly during upwelling episodes. Production of Protoperidinium conicum (Gran) Balech and Protoperidinium pentagonum (Gran) Balech cysts and total diatom valves were related, providing evidence of a predator-prey relationship. The export cyst-flux of E. aculeatum, P. americanum, P. monospinum, and P. stellatum was strongly linked to the flux of total diatom valves and CaCO3, whereas the export production of Echinidinium granulatum Zonn. and Protoperidinium subinerme (Paulsen) A. R. Loebl. correlated with total organic carbon, suggesting potential consumption of diatoms, prymnesiophytes, and organic matter, respectively. Sinking velocities were at least 274 m · d**-1, which is in range of the diatom- and coccolith-based phytoplankton aggregates and "slower" fecal pellets. Species-selective degradation did not occur in the water column, but on the ocean floor.