977 resultados para California, USA
Resumo:
While semantic search technologies have been proven to work well in specific domains, they still have to confront two main challenges to scale up to the Web in its entirety. In this work we address this issue with a novel semantic search system that a) provides the user with the capability to query Semantic Web information using natural language, by means of an ontology-based Question Answering (QA) system [14] and b) complements the specific answers retrieved during the QA process with a ranked list of documents from the Web [3]. Our results show that ontology-based semantic search capabilities can be used to complement and enhance keyword search technologies.
Resumo:
This paper is interested in conceptualising the often raised issue of over- and under-contributing in coalition operations; that of how and why members of complex coalitions2 may be punching above and below their weight, respectively. To this end, the first section presents a parsimonious baseline assumption regarding what variables may fundamentally inform coalition burden-sharing, to subsequently discuss how much each of these are found to play a role in the Afghanistan context. The second section elaborates on this by assessing the perception and the interpretation of threats by coalition member countries, related to Afghanistan, as this pertains to prioritising other variables within the scheme outlined in the previous section. The third and fourth sections then proceed to examine and further enrich the existing literature on coalition burden-sharing, and provide further insights regarding the operations of the International Security Assistance Force–Afghanistan, and regarding ISAF member-country decisionmaking; the objective here is to generate further refined assumptions, that can permit a preliminary assessment of the phenomenon of uneven burden-sharing in ISAF, complementing the initial baseline expectations.
Resumo:
Solar-type helium (He) and neon (Ne) in the Earth's mantle were suggested to be the result of solarwind loaded extraterrestrial dust that accumulated in deep-sea sediments and was subducted into the Earth's mantle. To obtain additional constraints on this hypothesis, we analysed He, Ne and argon (Ar) in high pressure-low temperature metamorphic rocks representing equivalents of former pelagic clays and cherts from Andros (Cyclades, Greece) and Laytonville (California, USA). While the metasediments contain significant amounts of 4He, 21Ne and 40Ar due to U, Th and K decay, no solar-type primordial noble gases were observed. Most of these were obviously lost during metamorphism preceding 30 km subduction depth. We also analysed magnetic fines from two Pacific ODP drillcore samples, which contain solar-type He and Ne dominated by solar energetic particles (SEP). The existing noble gas isotope data of deep-sea floor magnetic fines and interplanetary dust particles demonstrate that a considerable fraction of the extraterrestrial dust reaching the Earth has lost solar wind (SW) ions implanted at low energies, leading to a preferential occurrence of deeply implanted SEP He and Ne, fractionated He/Ne ratios and measurable traces of spallogenic isotopes. This effect is most probably caused by larger particles, as these suffer more severe atmospheric entry heating and surface ablation. Only sufficiently fine-grained dust may retain the original unfractionated solar composition that is characteristic for the Earth's mantle He and Ne. Hence, in addition to the problem of metamorphic loss of solar noble gases during subduction, the isotopic and elemental fractionation during atmospheric entry heating is a further restriction for possible subduction hypotheses.
Resumo:
[EN] For sea turtles, to hatch and emerge from the nest communally is essential to decrease hatchling mortality. Thus, it is very important within a nest the simultaneous fertilization and the synchronized embryonic development of all eggs. On loggerhead nesting beaches of Cape Verde we have studied the individual variability on developmental synchrony of embryos and the influence on this process of some biological, environmental and management factors. We have compared this trait within and between 34 nests naturally incubated on the beach and 34 nests relocated to a beach hatchery during the 2009 and 2010 nesting seasons.
Resumo:
[EN] Nesting beach surveys are the most widely implemented monitoring tool in use by the global sea turtle community and are an important component of a comprehensive program to assess and monitor the status of sea turtle populations. These assessments are necessary to evaluate the effects of recovery and conservation activities that are being implemented at all life history stages. Monitoring techniques employed on nesting beaches range from highly structured standardized sampling to “snapshots” of nesting activity within a nesting season. Very long-term nest counts data (more than twenty years) were analyzed for some turtle populations.
Resumo:
[EN] The 70 km of white sandy beaches of Boa Vista island in Cape Verde harbours one of the largest rookeries of the endangered loggerhead sea turtle, Caretta caretta. From middle June to early October, approximately 2000 to 4000 females lay up to 20000 nests annually. However, female beach selection, nesting success and nest density strongly varies among beaches and spatial patterns of nest abundance and distribution are relatively constant among seasons. The numbers of nesting activities and nests have been recorded along all beaches of the island during four nesting seasons (2007-2010)
Resumo:
[EN] For sea turtles, to hatch and emerge from the nest communally is essential to decrease hatchling mortality. Thus, it is very important within a nest the simultaneous fertilization and the synchronized embryonic development of all eggs. On loggerhead nesting beaches of Cape Verde we have studied the individual variability on developmental synchrony of embryos and the influence on this process of some biological, environmental and management factors. We have compared this trait within and between 34 nests naturally incubated on the beach and 34 nests relocated to a beach hatchery during the 2009 and 2010 nesting seasons.
Resumo:
[EN] Nesting beach surveys are the most widely implemented monitoring tool in use by the global sea turtle community and are an important component of a comprehensive program to assess and monitor the status of sea turtle populations. These assessments are necessary to evaluate the effects of recovery and conservation activities that are being implemented at all life history stages. Monitoring techniques employed on nesting beaches range from highly structured standardized sampling to “snapshots” of nesting activity within a nesting season. Very long-term nest counts data (more than twenty years) were analyzed for some turtle populations.
Resumo:
[EN] Many sea turtle nesting areas are experiencing a tremendous growth in tourism during the last decades that will likely continue in the near future. Many touristic activities involve light pollution by the increasing presence of vehicles close or even over the beaches. Vehicles can drive towards or along the beaches and even stay with the lights turned on illuminating during prolonged periods of time significant zones with sea turtle nesting activity. Thus, it is important to evaluate the impact of car light pollution on both nesting females and newborns in their search of the sea.
Resumo:
[EN] Artificial illumination of nesting beaches is one of the main threats to endangered sea turtle populations. Nocturnal lighting can impair female nest site selection and nesting success, as well as behavior and hatchling survival in their way from the nest surface to the seashore. The island of Boavista (Cape Verde) hosts the third largest loggerhead nesting aggregation in the world and the only relevant population in the Eastern Atlantic coast. Several threats such as fishing by-catch and female slaughter during nesting are severely threatening its conservation.
Resumo:
[EN] The hawksbill sea turtle (Eretmochelys imbricata) is a circumglobal tropical species listed as Critically Endangered by the IUCN. While it is known that at least one stock occurs around the rookeries of São Tome and Principe and Bioko Islands, the eastern Atlantic remains genetically unexplored. We present the first analysis of mitochondrial DNA (mtDNA) sequences (n = 28) of hawksbill juveniles in a foraging aggregation at the Cape Verde Islands, an archipelago located in the eastern Atlantic. The mean size (minimun curve carapace length) of the studied individuals was 42.45 cm.
Resumo:
[EN] The incubation is an essential life period for oviparous species that very often experiences a high mortality. In some reptile species the number of eggs that develop together in the incubation chamber affects survival and hatchling phenotype. Sea turtle eggs develop in underground locations on sandy beaches in large masses that usually have more than 80 eggs. Natural egg mortality seems to vary among species and for the sensitive leatherbacks, external eggs seems to survive better than internal ones within the nest.