589 research outputs found
Blade for turbine engine
A blade for a turbine engine having a centerline. The blade comprises: a root section extending at an angle relative to the centerline; and an airfoil section extending from the root section. The root section is directly adjacent said airfoil section. In other words, the blade is neckless. The blade is part of a rotor assembly, and is preferably a fan blade
Functional improvement after arthroscopic meniscectomy in patients with degenerative versus traumatic meniscal lesions
The diagnosis, morphological particularities, and surgical technique in a case of intravascular leiomyoma extended to the right heart chambers
Intravenous leiomyoma is a benign smooth muscle cell tumor of uterine origin that may grow into the pelvic veins and the inferior vena cava. It usually affects premenopausal women and the majority (90%) are parous. Because cardiac involvement is present in up to 10% of cases, it may be misdiagnosed as a primary cardiac tumor or a venous thrombus-in-transit. We describe a case of intravascular leiomyomatosis with cardiac extension and the morphological particularities of the removed tumor
Around the tangent cone theorem
A cornerstone of the theory of cohomology jump loci is the Tangent Cone
theorem, which relates the behavior around the origin of the characteristic and
resonance varieties of a space. We revisit this theorem, in both the algebraic
setting provided by cdga models, and in the topological setting provided by
fundamental groups and cohomology rings. The general theory is illustrated with
several classes of examples from geometry and topology: smooth quasi-projective
varieties, complex hyperplane arrangements and their Milnor fibers,
configuration spaces, and elliptic arrangements.Comment: 39 pages; to appear in the proceedings of the Configurations Spaces
Conference (Cortona 2014), Springer INdAM serie
Whale-watching contributions for the study of cetacean-cephalopod interactions
Cephalopods are the primary source of food for several species of odontocetes. The unstable nature of this trophic resource is likely to affect the ecology of their cetacean predators. This can be reflected in whale conservation status but also in the tourist activities which focus on cetacean observation. However, the study of cetacean-cephalopod interactions is limited by the complicated and heavy logistics of dedicated scientific campaigns. Fortunately, this limitation can be overcome by coupling modern molecular tools with indirect sampling methods. In this note we present the first results of a project to involve whale watching companies, which represent an intense observation effort worldwide, in the collection of biological material and information for studies of cetacean-cephalopod interactions and cephalopod distribution. In early 2020 we contacted all whale watching companies on São Miguel Island, Azores. All of them welcomed the invitation and received training and a sampling kit. Nine cephalopod tissue samples were collected, most of them in close association with sperm whales. All samples were determined by DNA barcoding (confirmed in a few cases by morphological observation) to belong to the gelatinous giant octopod Haliphron atlanticus (Octopoda, Alloposidae). We believe that, although the Azores may have particularly favourable conditions for participatory science, similar programs can be replicated elsewhere.info:eu-repo/semantics/publishedVersio
DR-bearing T lymphocytes in thoracic duct lymph
T cells having DR antigens were shown to be present in high numbers in the thoracic duct lymph of patients undergoing long-term drainage. As drainage progresses the proportion of T DR cells in the lymph increases to levels as high as 70% at 6 weeks. These cells were demonstrated by showing that T cells isolated by sheep red cell rosetting were killed by the action of rabbit anti-B-cell sera and of HLA-DR antisera. The HLA-DR specificities found on the T cells corresponded with those on the patients’ B lymphocytes
Design of a decision support system for improving air quality assessment
Establishing a system that allows the transition from environmental and traffic monitoring to environmental management at the personal level has become a necessity. Such a system will improve the life quality, reduce health costs and increase the support of vulnerable groups (i.e., the elderly, children). ESTABLISH project aims to advance an innovative platform which allows converting environmental (sensor) data into actionable information for users to provide a healthier and safer environment thereby improving the quality of life. Smart adaptive services providing real-time feedback tailored to specific user and application needs will be developed by combining networked sensors and other data sources with adaptive models. This paper will present the on-going research within the ESTABLISH project related to the development of a decision support component which assesses the air quality. Based on real-time monitoring and quantification methods, and certain types of notifications for risk groups and general populations, the proposed system links pollutant concentrations to individual health risks. The proposed decision support for air quality assessment is structured on two components. The first component is represented by the comparison with the limit values provided by the legislation, and the second is the forecast of near-real-time air pollution episodes (based on trigger values). Thus, for each pollutant considered (PM2.5, PM10, SO2, NO2, O3, and CO) the frequency of pollutants concentrations measurement, the averaging periods according to the legislation, the averaging period and the limit values used for the notification component were established
Quantum communication networks with optical vortices
Quantum communications bring a paradigm change in internet security by using
quantum resources to establish secure keys between parties. Present-day quantum
communications networks are mainly point-to-point and use trusted nodes and key
management systems to relay the keys. Future quantum networks, including the
quantum internet, will have complex topologies in which groups of users are
connected and communicate with each-other. Here we investigate several
architectures for quantum communication networks. We show that photonic orbital
angular momentum (OAM) can be used to route quantum information between
different nodes. Starting from a simple, point-to-point network, we will
gradually develop more complex architectures: point-to-multipoint,
fully-connected and entanglement-distribution networks. As a particularly
important result, we show that an -node, fully-connected network can be
constructed with a single OAM sorter and OAM values. Our results pave the
way to construct complex quantum communication networks with minimal resources.Comment: 10 pages, 9 figure
Chamber basis of the Orlik-Solomon algebra and Aomoto complex
We introduce a basis of the Orlik-Solomon algebra labeled by chambers, so
called chamber basis. We consider structure constants of the Orlik-Solomon
algebra with respect to the chamber basis and prove that these structure
constants recover D. Cohen's minimal complex from the Aomoto complex.Comment: 16 page
Cd content in phosphate fertilizer: Which potential risk for the environment and human health?
Cadmium (Cd) is a heavy metal that accumulates in soil and in living organisms and causes severe and permanent damage. Its presence in the soil depends largely on the use of phosphate fertilizers. Phosphorite and apatite rocks used in phosphate fertilizers production contain several other minerals, including Cd. The amount of Cd incorporated in phosphate fertilizers depends on the type of phosphorite and apatite rocks (with low or high Cd content). Cd is present in soil mainly in insoluble form and has no bioavailability for plants. However, plants can increase Cd solubility by releasing root exudates that change the pH of the rhizosphere, therefore increasing Cd accumulation. Once crops absorb Cd, it enters the food chain. Food is the primary source of Cd exposure (for the non-smoking population), with cereals, nuts and legumes, and fish and shellfish being the major contributors. Progressive accumulation of Cd in humans impairs kidney function, affects the liver, and causes bone demineralization. Cd classification as a human carcinogen goes back to the 1990s. The European Union adopted Regulation (EU) 2019/1009, limiting Cd content in organo-mineral fertilizer having total phosphorus (P) content of 5% P2O5 equivalent at 60 mg kg−1 P2O5. This threshold seems inadequate compared to the threshold values for Cd currently in place in some EU countries: 12 member states have a Cd threshold between 20 and 50 mg kg−1 P2O5, 8 have the same threshold as that proposed in the regulation, and 2 have a higher threshold. Meanwhile, the new EU Regulation on CAP Strategic Plans explicitly references soil health and fertility protection and the limitation of contaminants in fertilizers. Fertilizers with low Cd content, with thresholds no higher than 20 mg kg−1 P2O5, would effectively limit bioaccumulation. As stopping P fertilizer application cannot be an option, strategies such as the use of P fertilizers with low Cd content, the use of cultivars that accumulate less Cd in their consumed parts, production of mineral P fertilizers with higher nutrient use efficiency than those actually produced, the decadmiation of P rocks from the raw materials, soil phytoremediation before crops cultivation, and increased use of recovered nutrients, should be adopted
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