We present a description of the design process, prototyping and production of the hybrid circuits for the front-end electronics of the Upstream Tracker at LHCb. The multilayer polyamide-based printed ...circuit boards, or hybrids, are designed to host the front-end ASICs. The ASICs require an optimized power delivery network from 0 to 120MHz, with a maximum of 10^-2 Ohms round-trip resistance, and 100 Ohms differential traces. Hybrids are required to have minimal radiation length, and to withstand the harsh environmental conditions of the data taking through intrinsic radiation hardness characteristics.
We studied the diving behavior of Red-legged Cormorants (Phalacrocorax gaimardi) in Patagonia, Argentina, using VHF radio-transmitters deployed during incubation. Red-legged Cormorants made foraging ...trips in inshore waters less than 15 m deep. Mean dive duration was 26.8 ± 2.0 sec while mean time at surface was 9.2 ± 0.9 sec (n = 2217 dives). The birds spent 74% of their foraging time underwater. Diving efficiency was different among individuals, and was among the highest reported for the Phalacrocoracidae. Dive variables were correlated with the height of the tide, suggesting that the birds forage on the seabed. Red-legged Cormorants were efficient divers, investing most of their feeding time underwater and foraging in shallow waters, maximizing bottom time. Our results are consistent with the hypothesis that Red-legged Cormorant diving behavior is strongly influenced by a combination of environmental variables (bottom heterogeneity and high tide width) characteristic of the south coast of Patagonia. Comportamiento de Buceo del Phalacrocorax gaimardi en la Patagonia Sudoriental, Argentina Resumen. Se estudió el comportamiento de buceo del Phalacrocorax gaimardi en Patagonia, Argentina, usando transmisores VHF instalados durante el periodo de la incubación. P. gaimardi realizó sus viajes de alimentación en áreas costeras poco profundas (<15 m). La duración media del buceo fue 26.8 ± 2.0 seg y el tiempo medio en superficie de 9.2 ± 0.9 seg (n = 2217). Las aves pasaron bajo el agua un 74% de su tiempo de alimentación, mostrando una de las eficiencias de buceo más altas mencionadas para los Phalacrocoracidae. Los parámetros de buceo se correlacionaron con la altura de la marea, sugiriendo que las aves se alimentaron en el fondo marino. Los individuos de P. gaimardi fueron eficientes buceadores, invirtiendo la mayoría de su tiempo de alimentación debajo del agua en aguas someras, maximizando el tiempo en el fondo marino. Nuestros resultados apoyan la hipótesis que P. gaimardi tiene un comportamiento de buceo que responde a las características ambientales de la costa sur de la Patagonia (heterogeneidad del fondo marino y grandes amplitudes de marea).
The foraging behavior and feeding locations of the Red-legged Cormorant (Phalacrocorax gaimardi) were studied at Ria Deseado, Argentina during the last week of the incubation period in 1999. VHF ...radio-transmitters were deployed on six nesting adult cormorants. Red-legged Cormorants fed during the daylight hours and made 4.0 plus or minus 0.8 trips per day, with a mean duration of 1.2 plus or minus 0.8 h. Birds spent 27% of daylight hours away from the colony on feeding trips, diving for 96% of the foraging trip, and made a mean of 78 dives per trip. Mean foraging range was 1.9 plus or minus 0.9 km, being the shortest of any of the Patagonian cormorant species. Red-legged Cormorants fed mainly in shallow waters <5 m deep and within one km from the shore. Most of the feeding trips were undertaken during falling tide, when the birds performed the shortest feeding trips with maximum diving rates and, probably minimized transit times and maximized searching time on the seafloor. Our results show that foraging behavior is mainly influenced by environmental factors such as the direction of the tide. Red-legged Cormorants seems able to forage by selecting the appropriated tidal conditions to minimize foraging effort.
Male and female Rock Shags (Phalacrocorax magellanicus) are not obviously sexually dimorphic in plumage or size and are thus difficult to distinguish in the field. We evaluated the utility of two ...different DNA-based techniques for sexing adult Rock Shags. We found that the primer set 2550F/2718R (originally tested in three individuals of P. carbo), with minor differences in the forward primer, provided a consistent and simple sexing method for Rock Shags. Moreover, we obtained three reliable discriminant functions for sexing adults from three different colony sites between 42° to 47°S in coastal Patagonia, Argentina. Discriminant analysis of five external characters of adult birds indicated that head, bill, and wing lengths were the most accurate variables for use in a discriminant function model, predicting the sex of 80–86% of the birds. Males were significantly larger than females for all body measurements except for bill depth. Rock Shags showed less marked sexual dimorphism than other phalacrocoraciid species.
In March of 1982-1984 and 1986-1990 we counted carcasses of Magellanic Penguins (Spheniscus magellanicus) along the Chubut coast of Argentina. The number of carcasses found per kilometer of beach on ...the shoreline ranged from 49 in 1982 to 9 in 1990. In 1984, 22% of the dead penguins were oiled as compared to 66% in 1987. Oiled penguins were found along all parts of the Chubut coast showing that chronic oil pollution is not a local problem. Oiled carcasses were more common near oil ports, where oil pollution is probably worse, and they were more common on headlands than away from the ports or in bays. More fledglings than adults were found dead along the coast. Approximately 65% of dead adults and 31% of dead fledglings were oiled. In years when the natural mortality rate was low for adults (1986 and 1987), a higher percent of the carcasses had petroleum, suggesting oil was an important cause of adult mortality. Starvation appeared to be the most common cause of death for fledglings, whereas petroleum pollution was the main cause of death for adults. We estimate that at least 1.1% of the adult population and 6.0% of the fledglings are oiled in February and March of each year. Since penguins migrate twice a year, more than 20,000 adults and 22,000 juveniles may be killed along 3,000 km of Argentine coast (Chubut and Santa Cruz) each year due to oil pollution. These data suggest that chronic petroleum pollution is a significant mortality factor for adult Magellanic Penguins along the coast of Argentina and may be depressing population numbers.
We studied the diving behavior of Red-legged Cormorants (Phalacrocorax gaimardi) in Patagonia, Argentina, using VHF radio-transmitters deployed during incubation. Red-legged Cormorants made foraging ...trips in inshore waters less than 15 m deep. Mean dive duration was 26.8 A- 2.0 sec while mean time at surface was 9.2 A- 0.9 sec (n = 2217 dives). The birds spent 74% of their foraging time underwater. Diving efficiency was different among individuals, and was among the highest reported for the Phalacrocoracidae. Dive variables were correlated with the height of the tide, suggesting that the birds forage on the seabed. Red-legged Cormorants were efficient divers, investing most of their feeding time underwater and foraging in shallow waters, maximizing bottom time. Our results are consistent with the hypothesis that Red-legged Cormorant diving behavior is strongly influenced by a combination of environmental variables (bottom heterogeneity and high tide width) characteristic of the south coast of Patagonia. Comportamiento de Buceo del Phalacrocorax gaimardi en la Patagonia Sudoriental, ArgentinaOriginal Abstract: Se estudio el comportamiento de buceo del Phalacrocorax gaimardi en Patagonia, Argentina, usando transmisores VHF instalados durante el periodo de la incubacion. P. gaimardi realizo sus viajes de alimentacion en areas costeras poco profundas (<15 m). La duracion media del buceo fue 26.8 A- 2.0 seg y el tiempo medio en superficie de 9.2 A- 0.9 seg (n = 2217). Las aves pasaron bajo el agua un 74% de su tiempo de alimentacion, mostrando una de las eficiencias de buceo mas altas mencionadas para los Phalacrocoracidae. Los parametros de buceo se correlacionaron con la altura de la marea, sugiriendo que las aves se alimentaron en el fondo marino. Los individuos de P. gaimardi fueron eficientes buceadores, invirtiendo la mayoria de su tiempo de alimentacion debajo del agua en aguas someras, maximizando el tiempo en el fondo marino. Nuestros resultados apoyan la hipotesis que P. gaimardi tiene un comportamiento de buceo que responde a las caracteristicas ambientales de la costa sur de la Patagonia (heterogeneidad del fondo marino y grandes amplitudes de marea).
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