3,614 research outputs found
Frequency UWB Channel
Ultra wideband (UWB) transmission systems are characterized with either a fractional bandwidth of more that 20%, or a large absolute bandwidth (>500 MHz) in the 3.1 GHz to 10.6 GHz band, and for a very low power spectral density (-41.25 dBm/MHz, equivalent to 75nW/MHz), which allows to share the spectrum with other narrowband and wideband systems without causing interference (FCC, 2002), this spectral allocation has initiated an extremely productive activity for industry and academia. Wireless communications experts now consider UWB as available spectrum to be utilized with a variety of techniques and not specifically related to the generation and detection of short RF pulses as in the past (Batra, 2004). For this reason, UWB systems are emerging as the best solution for high speed short range indoor wireless communication and sensor networks, with applications in home networking, high-quality multimedia content delivery, radars systems of high accuracy, etc. UWB has many attractive properties, including low interference to and from other wireless systems, easier wall and floor penetration, and inherent security due to its Low Probability Interception/Detection (LPI/D). Two of the most promising applications of UWB are High Data Rate Wireless Personal Area Network (HDR-WPAN), and Sensor Networks, where the good ranging and geo-location capabilities of UWB are particularly useful and of interest for military applications (Molisch, 2005)
Cierre de parafuga valvular con dispositivos off - label: un recurso valioso
We present the case of a patient with a paravalvular leak of mechanical prosthesis in aortic position. Due to a recent previous surgery, it was decided to perform a percutaneous repair to reduce perioperative risk, under an off-label indication using a device for ventricular septal defect closure, successful and without complications in the follow-up.Se presenta el caso de un paciente con parafuga valvular de prótesis mecánica en posición aórtica. Por intervención quirúrgica previa reciente se decide llevar a reparo percutáneo para disminuir riesgo perioperatorio, bajo indicación no aprobada (off label) usando un dispositivo para cierre de comunicación interventricular, exitoso y sin complicaciones en el seguimiento
Limitations of the IAU2000 nutation model accuracy due to the lack of Oppolzer terms of planetary origin
[EN] Context. The current IAU2000 nutation model performed different approximations, one of them being that the Oppolzer terms associated to the planetary perturbations of the nutations were assumed to be smaller than 5 μas and thus were neglected. At present, the uncertainties of the amplitudes of individual components of the observed nutations are better, and the conventional nutation model does not fit the accuracy requirements pursued by the International Astronomical Union (IAU) and the International Association of Geodesy (IAG).
Aims. The objective of this work is to estimate the magnitude of the lacking Oppolzer terms of the planetary nutations and find out whether they are still negligible or not.
Methods. The Oppolzer terms resulting from the direct and indirect planetary perturbations of the Earth’s rotation have been computed for a two-layer Earth model following the Hamiltonian theory of the non-rigid-Earth.
Results. The planetary Oppolzer terms for the non-rigid Earth are not really negligible as believed, and some of them have amplitudes larger than 10 μas, therefore significantly above the current level of uncertainty of individual harmonic constituents.
Conclusions. In the short term, the IAU2000 nutation model must be supplemented with suitable corrections accounting for those missing components; its planetary component must be thoroughly revised in the medium term.SIThis work was partly supported by grant AYA2016-79775-P (AEI/FEDER, UE)
Molecular and functional characterisation of two elovl4 elongases involved in the biosynthesis of very long-chain (>C24) polyunsaturated fatty acids in black seabream Acanthopagrus schlegelii
Elongation of very long-chain fatty acid (Elovl) 4 proteins are important fatty acyl elongases that participate in the biosynthesis of long-chain (C20-24) and very long-chain (˃C24) polyunsaturated fatty acids (LC-PUFA and VLC-PUFA, respectively) in teleost fish, especially in marine species. Moreover, knowledge of Elovl4 and other elongases such as Elovl2 has contributed to an advanced understanding of the LC-PUFA biosynthetic pathway in marine fish. In the present study, elovl4a and elovl4b were cloned from black seabream Acanthopagrus schlegelii and functionally characterised using recombinant expression in yeast. The elovl4a and elovl4b cDNA sequences included open reading frames (ORF) of 969 and 918 base pairs (bp), encoding proteins of 322 and 315 amino acids (aa), respectively. The functional characterisation of A. schlegelii Elovl4 proteins showed they were able to utilise all assayed C18-22 PUFA substrates except 22:6n-3. Moreover, it was particularly noteworthy that both A. schlegelii Elovl4a and Elovl4b proteins had the ability to elongate 20:5n-3 and 22:5n-3 to 24:5n-3, which can be potentially desaturated and β-oxidised to 22:6n-3. Tissue transcript abundance analysis showed the highest expression of elovl4a and elovl4b in brain and eye, respectively, suggesting these tissues were major sites for VLC-PUFA biosynthesis in black seabream. The functions of the A. schlegelii Elovl4-like elongases, Elovl4a and Elovl4b, characterised in the present study, along with those of the Elovl5 and fatty acyl desaturase (Fads2) proteins of A. schlegelii characterised previously, provided evidence of the biosynthetic pathways of LC-PUFA and VLC-PUFA in this teleost species
Lung tumorspheres as a drug screening platform against cancer stem cells
Treatment resistance and metastasis are linked to cancer stem cells (CSCs). This population represents a promising target, but remains unexplored in lung cancer. The main objective of this study was to characterize lung CSCs and discover new therapeutic strategies
The New Era of Business Intelligence Applications: Buildingfrom a Collaborative Point of View
Collaborative business intelligence (BI) iswidely embraced by enterprises as a way of making themost of their business processes. However, decision mak-ers usually work in isolation without the knowledge or thetime needed to obtain and analyze all the available infor-mation for making decisions. Unfortunately, collaborativeBI is currently based on exchanging e-mails and documentsbetween participants. As a result, information may be lost,participants may become disoriented, and the decision-making task may not yield the needed results. The authorspropose a modeling language aimed at modeling andeliciting the goals and information needs of participants ofcollaborative BI systems. This approach is based on inno-vative methods to elicit and model collaborative systemsand BI requirements. A controlled experiment was per-formed to validate this language, assessing its under-standability, scalability, efficiency, and user satisfaction byanalyzing two collaborative BI systems. By using theframework proposed in this work, clear guideless can beprovided regarding: (1) collaborative tasks, (2) their par-ticipants, and (3) the information to be shared among them.By using the approach to design collaborative BI systems,practitioners may easily trace every element needed in thedecision processes, avoiding the loss of information andfacilitating the collaboration of the stakeholders of suchprocesses
Dietary Effect on the Proteome of the Common Octopus (Octopus vulgaris) Paralarvae
Nowadays, the common octopus (Octopus vulgaris) culture is hampered by massive
mortalities occurring during early life-cycle stages (paralarvae). Despite the causes
of the high paralarvae mortality are not yet well-defined and understood, the
nutritional stress caused by inadequate diets is pointed out as one of the main
factors. In this study, the effects of diet on paralarvae is analyzed through a
proteomic approach, to search for novel biomarkers of nutritional stress. A total of 43
proteins showing differential expression in the different conditions studied have been
identified. The analysis highlights proteins related with the carbohydrate metabolism:
glyceraldehyde-3-phosphate-dedydrogenase (GAPDH), triosephosphate isomerase;
other ways of energetic metabolism: NADP+-specific isocitrate dehydrogenase, arginine
kinase; detoxification: glutathione-S-transferase (GST); stress: heat shock proteins
(HSP70); structural constituent of eye lens: S-crystallin 3; and cytoskeleton: actin,
actin-beta/gamma1, beta actin. These results allow defining characteristic proteomes
of paralarvae depending on the diet; as well as the use of several of these proteins
as novel biomarkers to evaluate their welfare linked to nutritional stress. Notably, the
changes of proteins like S-crystallin 3, arginine kinase and NAD+ specific isocitrate
dehydrogenase, may be related to fed vs. starving paralarvae, particularly in the first
4 days of development.En prens
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