1,085 research outputs found
Unbounded violations of bipartite Bell Inequalities via Operator Space theory
In this work we show that bipartite quantum states with local Hilbert space
dimension n can violate a Bell inequality by a factor of order (up
to a logarithmic factor) when observables with n possible outcomes are used. A
central tool in the analysis is a close relation between this problem and
operator space theory and, in particular, the very recent noncommutative
embedding theory. As a consequence of this result, we obtain better Hilbert
space dimension witnesses and quantum violations of Bell inequalities with
better resistance to noise
Static circularly symmetric perfect fluid solutions with an exterior BTZ metric
In this work we study static perfect fluid stars in 2+1 dimensions with an
exterior BTZ spacetime. We found the general expression for the metric
coefficients as a function of the density and pressure of the fluid. We found
the conditions to have regularity at the origin throughout the analysis of a
set of linearly independent invariants. We also obtain an exact solution of the
Einstein equations, with the corresponding equation of state , which
is regular at the origin.Comment: 10 pages, 1 figure, revtex 4. This paper is in honor of Alberto
Garcia's sixtieth birthday. Accepted by Gen. Rel. Gra
Absceso epidural cervical por peptostreptococcus anaerobius
Se presenta 1 caso de infección con absceso epidural a nivel cervical producido
por un Peplostreptococcus anaerobius en 1 paciente en el que se realizó previamente una artrodesis
C6-C7 por una hernia discal cervical. En la literatura no se han encontrado referencias
bibliográficas de casos similares, por la etiología y la localización. Se discute la importancia de
las infecciones por bacterias anaerobias en patología osteoarticular, métodos diagnósticos, así
como su abordaje terapéutico.A case of postsurgical infection with cervical epidural abscess produced by
Peptostreptococcus anaerobius is presented. The patient underwent previously a cervical arthrodesis
(levels C6-C7) due to a discal herniation. A similar case has not been found in the review of the
literature, taking into account its etiology and localization. It is discussed the importance of anerobic
bacterial infections in osteoarticular pathology, and diagnostic and therapeutic means
Increased incidence of entanglements and ingested marine debris in Dutch seals from 2010 to 2020
In recent decades, the amount of marine debris has increased in our oceans. As wildlife interactions with debris increase, so does the number of entangled animals, impairing normal behavior and potentially affecting the survival of these individuals. The current study summarizes data on two phocid species, harbor (Phoca vitulina) and gray seals (Halichoerus grypus), affected by marine debris in Dutch waters from 2010 to 2020. The findings indicate that the annual entanglement rate (13.2 entanglements/year) has quadrupled compared with previous studies. Young seals, particularly gray seals, are the most affected individuals, with most animals found or sighted with fishing nets wrapped around their necks. Interestingly, harbor seals showed a higher incidence of ingested debris. Species differences with regard to behavior, foraging strategies, and habitat preferences may explain these findings. The lack of consistency across reports suggests that it is important to standardize data collection from now on. Despite increased public awareness about the adverse environmental effects of marine debris, more initiatives and policies are needed to ensure the protection of the marine environment in the Netherlands
Electrochemical and bioelectrocatalytical properties of novel block-copolymers containing interacting ferrocenyl units
The electrochemical characterization of three different polystyrene-b-polybutadiene block copolymers functionalized with ferrocenyl units electronically communicated, PSm-PBn(HSiMeFc2)p where m=615, n=53, p=39 (1), m=375, n=92, p=76 (2) and m=455, n=204, p=170 (3), has been carried out both in solution and electrochemically deposited onto platinum electrodes. The bioelectrocatalytical properties of electrodes modified with the polymers in the nicotinamide dinucleotide (NADH) and glucose oxidase (GOx) oxidations have been investigated as a function of the constitution and structure of the polymers. The analytical properties of electrodes modified with these polymers as sensors of NADH and GOx are described. In addition, an amperometric biosensor for glucose, prepared by electrostatic immobilization of glucose oxidase onto a platinum electrode modified with one of the ferrocenyl block copolymers as an example, has been developed. The results confirm that electrodes modified with the examined copolymers act as efficient redox mediators for the electrocatalytic oxidation of both reduced nicotinamide dinucleotide cofactor and glucose oxidase. The reaction with NADH proceeds via formation of a charge-transfer intermediate before yielding the reaction products. This is a novel example of electrodes modified with ferrocene derivatives that can be applied to the determination of NADH without the use of diaphorase. The redox copolymers co-immobilized with glucose-oxidase have been successfully used as amperometric biosensors for glucose determinations. As expected these compounds allow using lower working potentials. The sensitivities and detection limits obtained are comparable or even better than those of other ferrocene-modified polymers mediator electrodes
The Differential Organization of F-Actin Alters the Distribution of Organelles in Cultured When Compared to Native Chromaffin Cells
Cultured bovine chromaffin cells have been used extensively as a neuroendocrine model to study regulated secretion. In order to extend such experimental findings to the physiological situation, it is necessary to study mayor cellular structures affecting secretion in cultured cells with their counterparts present in the adrenomedullary tissue. F-actin concentrates in a peripheral ring in cultured cells, as witnessed by phalloidin?rodhamine labeling, while extends throughout the cytoplasm in native cells. This result is also confirmed when studying the localization of ?-fodrin, a F-actin-associated protein. Furthermore, as a consequence of this redistribution of F-actin, we observed that chromaffin granules and mitochondria located into two different cortical and internal populations in cultured cells, whereas they are homogeneously distributed throughout the cytoplasm in the adrenomedullary tissue. Nevertheless, secretion from isolated cells and adrenal gland pieces is remarkably similar when measured by amperometry. Finally, we generate mathematical models to consider how the distribution of organelles affects the secretory kinetics of intact and cultured cells. Our results imply that we have to consider F-actin structural changes to interpret functional data obtained in cultured neuroendocrine cells.This study was supported by grants from the Spanish Ministerio
de Economía y Competitividad (BFU2011-25095 and BFU2015-
63684-P, MINECO, FEDER, UE) to LMG
Testing Matter Effects in Very Long Baseline Neutrino Oscillation Experiments
Assuming three-neutrino mixing, we study the capabilities of very long
baseline neutrino oscillation experiments to verify and test the MSW effect and
to measure the lepton mixing angle theta_13. We suppose that intense neutrino
and antineutrino beams will become available in so-called neutrino factories.
We find that the most promising and statistically significant results can be
obtained by studying nu_e ->nu_mu and \bar{nu}_e-> \bar{nu}_mu oscillations
which lead to matter enhancements and suppressions of wrong sign muon rates. We
show the theta_13 ranges where matter effects could be observed as a function
of the baseline. We discuss the scaling laws of rates, significances and
sensitivities with the relevant mixing angles and experimental parameters. Our
analysis includes fluxes, event rates and statistical aspects so that the
conclusions should be useful for the planning of experimental setups. We
discuss the subleading Delta m^2_{21} effects in the case of the LMA MSW
solution of the solar problem, showing that they are small for L >= 7000 km.
For shorter baselines, Delta m^2_{21} effects can be relevant and their
dependence on L offers a further handle for the determination of the
CP-violation phase \delta. Finally we comment on the possibility to measure the
specific distortion of the energy spectrum due to the MSW effect.Comment: 30 pages, 13 figures, figures and more discussion added, results and
conclusions unchange
Differences between CAFs and their paired NCF from adjacent colonic mucosa reveal functional heterogeneity of CAFs, providing prognostic information
Little is known about the difference in gene expression between carcinoma-associated fibroblasts (CAFs) and paired normal colonic fibroblasts (NCFs) in colorectal cancer. Paired CAFs and NCFs were isolated from eight primary human colorectal carcinoma specimens. In culture conditions, soluble factors secreted by CAFs in the conditioned media increased clonogenicity and migration of epithelial cancer cells lines to a greater extent than did NCF. In vivo, CAFs were more competent as tumour growth enhancers than paired NCFs when co-inoculated with colorectal cell lines. Gene expression analysis of microarrays of CAF and paired NCF populations enabled us to identify 108 deregulated genes (38 upregulated and 70 downregulated genes). Most of those genes are fibroblast-specific. This has been validated in silico in dataset GSE39396 and by qPCR in selected genes. GSEA analysis revealed a differential transcriptomic profile of CAFs, mainly involving the Wnt signallingsignalling pathway, focal adhesion and cell cycle. Both deregulated genes and biological processes involved depicted a considerable degree of overlap with deregulated genes reported in breast, lung, oesophagus and prostate CAFs. These observations suggest that similar transcriptomic programs may be active in the transition from normal fibroblast in adjacent tissues to CAFs, independently of their anatomic demarcation. Additionally NCF already depicted an activated pattern associated with inflammation. The deregulated genes signature score seemed to correlate with CAF tumour promoter abilities in vitro, suggesting a high degree of heterogeneity between CAFs, and it has also prognostic value in two independent datasets. Further characterization of the roles these biomarkers play in cancer will reveal how CAFs provide cancer cells with a suitable microenvironment and may help in the development of new therapeutic targets for cancer treatment
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