122 research outputs found
A 7-13 GHz low-noise tuned optical front-end amplifier for heterodyne transmission system application
Transmission of 32.1 Gbit/s RZ-D8PSK over 160 km using dispersion compensation by optical phase conjugation:[invited]
Center frequency shift and reduction of feedback in directly modulated external cavity lasers
O papel do “Mineral Resources Expert Group” dos EuroGeoSurveys no contexto mineral Europeu
ABSTRACT: Europe shows an inevitably growing and accelerating consumption
of mineral commodities and the high import dependence of strategic and
critical raw materials has a serious impact on the sustainability of the EU
manufacturing industry. The European Commission has long recognized
the challenge of sustainable supply of mineral raw materials and steps are
implemented to try to deal with this. In this context, EuroGeoSurveys and
its Mineral Resources Expert Group (MREG) serve as one of the contact
points for the Commission. The MREG is a group of earth scientists, experts
in Economic Geology that act under the umbrella body of EuroGeoSurveys.
The group acts upon requests and queries received by member states and
the European Commission and provides the best available mineral expertise
and information based on the knowledge of member Geological Surveys,
for policy, communication, public awareness and education purposes
at European level.RESUMO: A Europa mostra um inevitável e acelerado aumento de consumo
de recursos minerais. A alta dependência das importações de matérias-primas
estratégicas e críticas tem um forte impacto na sustentabilidade da indústria
transformadora da UE. A produção de muitas matérias primas depende apenas
de alguns países. O desafio do abastecimento sustentável tem sido reconhecido pela Comissão Europeia e foram implementadas etapas no sentido de
tal ser assegurado. Neste contexto, o EuroGeoSurveys e o seu Grupo de
Peritos em Recursos Minerais (MREG) servem como um dos pontos de
contacto para a Comissão. O MREG dos EuroGeoSurveys é um grupo de
Geocientistas, especialistas em Geologia Económica que trabalham sobre
a tutela dos EuroGeoSurveys. O grupo atua com base em solicitações e
consultas recebidas pelos Estados membros e pela Comissão Europeia e
fornece os melhores conhecimentos e informações disponíveis com base
no conhecimento geológico dos recursos minerais, nas esferas da política,
e de comunicação, conscientização pública e educação a nível europeu.info:eu-repo/semantics/publishedVersio
Europe's rare earth element resource potential: an overview of REE metallogenetic provinces and their geodynamic setting
Security of supply of a number of raw materials is of concern for the European Union; foremost among these are the rare earth elements (REE), which are used in a range of modern technologies. A number of research projects, including the EURARE and ASTER projects, have been funded in Europe to investigate various steps along the REE supply chain. This paper addresses the initial part of that supply chain, namely the potential geological resources of the REE in Europe. Although the REE are not currently mined in Europe, potential resources are known to be widespread, and many are being explored. The most important European resources are associated with alkaline igneous rocks and carbonatites, although REE deposits are also known from a range of other settings. Within Europe, a number of REE metallogenetic belts can be identified on the basis of age, tectonic setting, lithological association and known REE enrichments. This paper reviews those metallogenetic belts and sets them in their geodynamic context. The most well-known of the REE belts are of Precambrian to Palaeozoic age and occur in Greenland and the Fennoscandian Shield. Of particular importance for their REE potential are the Gardar Province of SW Greenland, the Svecofennian Belt and subsequent Mesoproterozoic rifts in Sweden, and the carbonatites of the Central Iapetus Magmatic Province. However, several zones with significant potential for REE deposits are also identified in central, southern and eastern Europe, including examples in the Bohemian Massif, the Iberian Massif, and the Carpathians
Virulence Factors for Hemolytic Uremic Syndrome, Denmark1
We present an analysis of strain and patient factors associated with the development of bloody diarrhea and hemolytic uremic syndrome (HUS) among Shiga toxin-producing Escherichia coli (STEC) patients registered in Denmark in a 6-year period. Of 343 STEC patients, bloody diarrhea developed in 36.4% and HUS in 6.1%. In a multivariate logistic regression model, risk factors for bloody diarrhea were the eae and stx2 genes, O groups O157 and O103, and increasing age. Risk factors for HUS were presence of the stx2 (odds ratio [OR] 18.9) and eae (OR undefined) genes, being a child, and having bloody diarrhea. O group O157, although associated with HUS in a univariate analysis (OR 4.0), was not associated in the multivariate analysis (OR 1.1). This finding indicates that, rather than O group, the combined presence of the eae and stx2 genes is an important predictor of HUS
Animal-to-Human Transmission of Salmonella Typhimurium DT104A Variant
Salmonella enterica serovar Typhimurium was isolated from a pig, a calf, and a child on a farm in the Netherlands. The isolates were indistinguishable by phenotyping and genotyping methods, which suggests nonfoodborne animal-to-animal and animal-to-human transmission. Persons in close contact with farm animals should be aware of this risk
Gut Hormones and Their Effect on Bone Metabolism. Potential Drug Therapies in Future Osteoporosis Treatment
Bone homeostasis displays a circadian rhythm with increased resorption during the night time as compared to day time, a difference that seems—at least partly—to be caused by food intake during the day. Thus, ingestion of a meal results in a decrease in bone resorption, but people suffering from short bowel syndrome lack this response. Gut hormones, released in response to a meal, contribute to this link between the gut and bone metabolism. The responsible hormones appear to include glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), known as incretin hormones due to their role in regulating glucose homeostasis by enhancing insulin release in response to food intake. They interact with their cognate receptors (GIPR and GLP-1R), which are both members of the class B G protein-coupled receptors (GPCRs), and already recognized as targets for treatment of metabolic diseases, such as type 2 diabetes mellitus (T2DM) and obesity. Glucagon-like peptide-2 (GLP-2), secreted concomitantly with GLP-1, acting via another class B receptor (GLP-2R), is also part of this gut-bone axis. Several studies, including human studies, have indicated that these three hormones inhibit bone resorption and, moreover, that GIP increases bone formation. Another hormone, peptide YY (PYY), is also secreted from the enteroendocrine L-cells (together with GLP-1 and GLP-2), and acts mainly via interaction with the class A GPCR NPY-R2. PYY is best known for its effect on appetite regulation, but recent studies have also shown an effect of PYY on bone metabolism. The aim of this review is to summarize the current knowledge of the actions of GIP, GLP-1, GLP-2, and PYY on bone metabolism, and to discuss future therapies targeting these receptors for the treatment of osteoporosis
The epidemiology of infectious gastroenteritis related reactive arthritis in U.S. military personnel: a case-control study
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