Kochen-Specker set with seven contexts

The Kochen-Specker (KS) theorem is a central result in quantum theory and has applications in quantum information. Its proof requires several yes-no tests that can be grouped in contexts or subsets of jointly measurable tests. Arguably, the best measure of simplicity of a KS set is the number of contexts. The smaller this number is, the smaller the number of experiments needed to reveal the conflict between quantum theory and noncontextual theories and to get a quantum vs classical outperformance. The original KS set had 132 contexts. Here we introduce a KS set with seven contexts and prove that this is the simplest KS set that admits a symmetric parity proof.Comment: REVTeX4, 7 pages, 1 figur

Memory cost of quantum contextuality

The simulation of quantum effects requires certain classical resources, and quantifying them is an important step in order to characterize the difference between quantum and classical physics. For a simulation of the phenomenon of state-independent quantum contextuality, we show that the minimal amount of memory used by the simulation is the critical resource. We derive optimal simulation strategies for important cases and prove that reproducing the results of sequential measurements on a two-qubit system requires more memory than the information carrying capacity of the system.Comment: 18 pages, no figures, v2: revised for clarit

Quantum social networks

We introduce a physical approach to social networks (SNs) in which each actor is characterized by a yes-no test on a physical system. This allows us to consider SNs beyond those originated by interactions based on pre-existing properties, as in a classical SN (CSN). As an example of SNs beyond CSNs, we introduce quantum SNs (QSNs) in which actor is characterized by a test of whether or not the system is in a quantum state. We show that QSNs outperform CSNs for a certain task and some graphs. We identify the simplest of these graphs and show that graphs in which QSNs outperform CSNs are increasingly frequent as the number of vertices increases. We also discuss more general SNs and identify the simplest graphs in which QSNs cannot be outperformed.Comment: REVTeX4, 6 pages, 3 figure

Basic exclusivity graphs in quantum correlations

A fundamental problem is to understand why quantum theory only violates some noncontextuality (NC) inequalities and identify the physical principles that prevent higher-than-quantum violations. We prove that quantum theory only violates those NC inequalities whose exclusivity graphs contain, as induced subgraphs, odd cycles of length five or more, and/or their complements. In addition, we show that odd cycles are the exclusivity graphs of a well-known family of NC inequalities and that there is also a family of NC inequalities whose exclusivity graphs are the complements of odd cycles. We characterize the maximum noncontextual and quantum values of these inequalities, and provide evidence supporting the conjecture that the maximum quantum violation of these inequalities is exactly singled out by the exclusivity principle.Comment: REVTeX4, 7 pages, 2 figure

Non-O1 Vibrio cholerae inguinal skin and soft tissue infection with bullous skin lesions in a patient with a penis squamous cell carcinoma

Vibrio spp. is a pathogen rarely isolated in cancer patients, and in most cases it is associated with haematological diseases. Cutaneous manifestations of this organism are even rarer. We report a case of Non-O1 Vibrio cholerae inguinal skin and soft tissue infection presenting bullous skin lesions in a young type II diabetic patient with a penis squamous cell carcinoma having a seawater exposure history

Room temperature silylation of alcohols catalyzed by metal organic frameworks

[EN] The commercial Al(OH)(BDC) (BDC: 1,4-benzenedicarboxylic acid) metal organic framework (Basolite A100) is a suitable heterogeneous catalyst for the silylation of benzylic and aliphatic alcohols by hexamethyldisilazane in toluene at room temperature. Al(OH)(BDC) is stable under the reaction conditions as evidenced by powder XRD and can be reused with minimal activity decrease.AD thanks University Grants Commission (UGC), New Delhi for the award of Assistant Professorship under its Faculty Recharge Programme. AD also thanks the Department of Science and Technology, India for the financial support through the Fast Track project (SB/FT/CS-166/2013) and the Generalidad Valenciana for financial aid supporting his stay in Valencia through the Prometeo programme. Financial support by the Spanish Ministry of Economy and Competitiveness (CTQ-2015-69 153-CO2-R1 and Severo Ochoa) and Generalidad Valenciana (Prometeo 2012-014) is gratefully acknowledgedDhakshinamoorthy, A.; Santiago-Portillo, A.; Concepción Heydorn, P.; Herance, JR.; Navalón Oltra, S.; Alvaro Rodríguez, MM.; García Gómez, H. (2017). Room temperature silylation of alcohols catalyzed by metal organic frameworks. Catalysis Science & Technology. 7(12):2445-2449. https://doi.org/10.1039/c7cy00834aS24452449712T. W. Greene and P. G. M.Wuts, Protective Groups in Organic Synthesis, Wiley & Sons, New York, 3rd edn, 1999, p. 116Sartori, G., Ballini, R., Bigi, F., Bosica, G., Maggi, R., & Righi, P. (2004). Protection (and Deprotection) of Functional Groups in Organic Synthesis by Heterogeneous Catalysis. Chemical Reviews, 104(1), 199-250. doi:10.1021/cr0200769Corey, E. J., & Snider, B. B. (1972). Total synthesis of (+-)-fumagillin. Journal of the American Chemical Society, 94(7), 2549-2550. doi:10.1021/ja00762a080Karimi, B., & Golshani, B. (2000). Mild and Highly Efficient Method for the Silylation of Alcohols Using Hexamethyldisilazane Catalyzed by Iodine under Nearly Neutral Reaction Conditions. The Journal of Organic Chemistry, 65(21), 7228-7230. doi:10.1021/jo005519sFirouzabadi, H., Iranpoor, N., Amani, K., & Nowrouzi, F. (2002). Tungstophosphoric acid (H3PW12O40) as a heterogeneous inorganic catalyst. Activation of hexamethyldisilazane (HMDS) by tungstophosphoric acid for efficient and selective solvent-free O-silylation reactions. Journal of the Chemical Society, Perkin Transactions 1, (23), 2601-2604. doi:10.1039/b208202kZareyee, D., & Karimi, B. (2007). A novel and highly efficient method for the silylation of alcohols with hexamethyldisilazane (HMDS) catalyzed by recyclable sulfonic acid-functionalized ordered nanoporous silica. Tetrahedron Letters, 48(7), 1277-1280. doi:10.1016/j.tetlet.2006.12.030Moghadam, M., Tangestaninejad, S., Mirkhani, V., Mohammadpoor-Baltork, I., Chahardahcheric, S., & Tavakoli, Z. (2008). Rapid and highly efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) catalyzed by reusable zirconyl triflate, [ZrO(OTf)2]. Journal of Organometallic Chemistry, 693(11), 2041-2046. doi:10.1016/j.jorganchem.2008.03.009Firouzabadi, H., Iranpoor, N., & Farahi, S. (2009). Highly regio- and chemoselective silylation of diethyl α-hydroxyphosphonates, alcohols and phenols in the presence of solid TiCl3(OTf) as a catalyst with hexamethyldisilazane (HMDS) at room temperature in the absence of solvent. Catalysis Communications, 10(11), 1547-1550. doi:10.1016/j.catcom.2009.04.013Shirini, F., Atghia, S. V., & Jirdehi, M. G. (2012). Nanocrystalline TiO2–HClO4 as a new, efficient and recyclable catalyst for the chemoselective trimethylsilylation of alcohols, phenols and deprotection of silyl ethers. Catalysis Communications, 18, 5-10. doi:10.1016/j.catcom.2011.11.002Sridhar, M., Raveendra, J., China Ramanaiah, B., & Narsaiah, C. (2011). An efficient synthesis of silyl ethers of primary alcohols, secondary alcohols, phenols and oximes with a hydrosilane using InBr3 as a catalyst. Tetrahedron Letters, 52(45), 5980-5982. doi:10.1016/j.tetlet.2011.08.151Shirini, F., Khaligh, N. G., & Akbari-Dadamahaleh, S. (2012). Preparation, characterization and use of 1,3-disulfonic acid imidazolium hydrogen sulfate as an efficient, halogen-free and reusable ionic liquid catalyst for the trimethylsilyl protection of hydroxyl groups and deprotection of the obtained trimethylsilanes. Journal of Molecular Catalysis A: Chemical, 365, 15-23. doi:10.1016/j.molcata.2012.08.002Villabrille, P., Romanelli, G., Quaranta, N., & Vázquez, P. (2010). An efficient catalytic route for the preparation of silyl ethers using alumina-supported heteropolyoxometalates. Applied Catalysis B: Environmental, 96(3-4), 379-386. doi:10.1016/j.apcatb.2010.02.035Shirini, F., & Mollarazi, E. (2007). Efficient trimethylsilylation of alcohols and phenols in the presence of ZrCl4 as a reusable catalyst. Catalysis Communications, 8(9), 1393-1396. doi:10.1016/j.catcom.2006.11.015Chughtai, A. H., Ahmad, N., Younus, H. A., Laypkov, A., & Verpoort, F. (2015). Metal–organic frameworks: versatile heterogeneous catalysts for efficient catalytic organic transformations. Chemical Society Reviews, 44(19), 6804-6849. doi:10.1039/c4cs00395kLiu, J., Chen, L., Cui, H., Zhang, J., Zhang, L., & Su, C.-Y. (2014). Applications of metal–organic frameworks in heterogeneous supramolecular catalysis. Chem. Soc. Rev., 43(16), 6011-6061. doi:10.1039/c4cs00094cDhakshinamoorthy, A., Asiri, A. M., & Garcia, H. (2015). Metal–organic frameworks catalyzed C–C and C–heteroatom coupling reactions. Chemical Society Reviews, 44(7), 1922-1947. doi:10.1039/c4cs00254gDhakshinamoorthy, A., & Garcia, H. (2014). Metal–organic frameworks as solid catalysts for the synthesis of nitrogen-containing heterocycles. Chem. Soc. Rev., 43(16), 5750-5765. doi:10.1039/c3cs60442jDhakshinamoorthy, A., Asiri, A. M., & Garcia, H. (2016). Mixed-metal or mixed-linker metal organic frameworks as heterogeneous catalysts. Catalysis Science & Technology, 6(14), 5238-5261. doi:10.1039/c6cy00695gDhakshinamoorthy, A., Alvaro, M., & Garcia, H. (2012). Commercial metal–organic frameworks as heterogeneous catalysts. Chemical Communications, 48(92), 11275. doi:10.1039/c2cc34329kSchneemann, A., Bon, V., Schwedler, I., Senkovska, I., Kaskel, S., & Fischer, R. A. (2014). Flexible metal–organic frameworks. Chem. Soc. Rev., 43(16), 6062-6096. doi:10.1039/c4cs00101jDhakshinamoorthy, A., Alvaro, M., & Garcia, H. (2010). Metal organic frameworks as heterogeneous catalysts for the selective N-methylation of aromatic primary amines with dimethyl carbonate. Applied Catalysis A: General, 378(1), 19-25. doi:10.1016/j.apcata.2010.01.042Boutin, A., Springuel-Huet, M.-A., Nossov, A., Gédéon, A., Loiseau, T., Volkringer, C., … Fuchs, A. H. (2009). Breathing Transitions in MIL-53(Al) Metal-Organic Framework Upon Xenon Adsorption. Angewandte Chemie International Edition, 48(44), 8314-8317. doi:10.1002/anie.200903153Sholl, D. S., & Lively, R. P. (2015). Defects in Metal–Organic Frameworks: Challenge or Opportunity? The Journal of Physical Chemistry Letters, 6(17), 3437-3444. doi:10.1021/acs.jpclett.5b01135Fang, Z., Bueken, B., De Vos, D. E., & Fischer, R. A. (2015). Defect-Engineered Metal-Organic Frameworks. Angewandte Chemie International Edition, 54(25), 7234-7254. doi:10.1002/anie.20141154

The Effect of a Mediterranean Diet on the Incidence of Cataract Surgery

Background: Cataract is a leading cause of vision impairment worldwide, and surgery is the only available treatment. The process that initiates lens opacification is dependent on the oxidative stress experienced by the lens components. A healthy overall dietary pattern, with the potential to reduce oxidative stress, has been suggested as a means to decrease the risk of developing cataract. We aimed to investigate the hypothesis that an intervention with a Mediterranean diet (MedDiet) rather than a low-fat diet could decrease the incidence of cataract surgery in elderly subjects. Methods: We included 5802 men and women (age range: 55–80 years) from the Prevención con Dieta Mediterránea study (multicenter, parallel-group, randomized controlled clinical trial) who had not undergone cataract surgery. They were randomly assigned to one of three intervention groups: (1) a MedDiet enriched with extra-virgin olive oil (EVOO) (n = 1998); (2) a MedDiet enriched with nuts (n = 1914), and a control group recommended to follow a low-fat diet (n = 1890). The incidence of cataract surgery was recorded yearly during follow-up clinical evaluations. Primary analyses were performed on an intention-to-treat basis. Cox regression analyses were used to assess the relationship between the nutritional intervention and the incidence of cataract surgery. Results: During a follow-up period of 7.0 years (mean follow-up period: 5.7 years; median: 5.9 years), 559 subjects underwent cataract surgery. Two hundred and six participants from the MedDiet + EVOO group, 174 from the MedDiet + Nuts group, and 179 from the control group underwent cataract surgery. We did not observe a reduction in the incidence of cataract surgery in the MedDiet groups compared to the control group. The multivariable adjusted hazard ratios were 1.03 (95% confidence interval [CI]: 0.84–1.26, p = 0.79) for the control group versus the MedDiet + EVOO group and 1.06 (95% CI: 0.86–1.31, p = 0.58) for the control group versus the MedDiet + Nuts group. Conclusions: To our knowledge, this is the first large randomized trial assessing the role of a MedDiet on the incidence of cataract surgery. Our results showed that the incidence of cataract surgery was similar in the MedDiet with EVOO, MedDiet with nuts, and low-fat diet groups. Further studies are necessary to investigate whether a MedDiet could have a preventive role in cataract surgery

Potassium Starvation in Yeast: Mechanisms of Homeostasis Revealed by Mathematical Modeling

The intrinsic ability of cells to adapt to a wide range of environmental conditions is a fundamental process required for survival. Potassium is the most abundant cation in living cells and is required for essential cellular processes, including the regulation of cell volume, pH and protein synthesis. Yeast cells can grow from low micromolar to molar potassium concentrations and utilize sophisticated control mechanisms to keep the internal potassium concentration in a viable range. We developed a mathematical model for Saccharomyces cerevisiae to explore the complex interplay between biophysical forces and molecular regulation facilitating potassium homeostasis. By using a novel inference method (“the reverse tracking algorithm”) we predicted and then verified experimentally that the main regulators under conditions of potassium starvation are proton fluxes responding to changes of potassium concentrations. In contrast to the prevailing view, we show that regulation of the main potassium transport systems (Trk1,2 and Nha1) in the plasma membrane is not sufficient to achieve homeostasis

Toxoplasma gondii-Induced Activation of EGFR Prevents Autophagy Protein-Mediated Killing of the Parasite

Toxoplasma gondii resides in an intracellular compartment (parasitophorous vacuole) that excludes transmembrane molecules required for endosome-lysosome recruitment. Thus, the parasite survives by avoiding lysosomal degradation. However, autophagy can re-route the parasitophorous vacuole to the lysosomes and cause parasite killing. This raises the possibility that T. gondii may deploy a strategy to prevent autophagic targeting to maintain the non-fusogenic nature of the vacuole. We report that T. gondii activated EGFR in endothelial cells, retinal pigment epithelial cells and microglia. Blockade of EGFR or its downstream molecule, Akt, caused targeting of the parasite by LC3(+) structures, vacuole-lysosomal fusion, lysosomal degradation and killing of the parasite that were dependent on the autophagy proteins Atg7 and Beclin 1. Disassembly of GPCR or inhibition of metalloproteinases did not prevent EGFR-Akt activation. T. gondii micronemal proteins (MICs) containing EGF domains (EGF-MICs; MIC3 and MIC6) appeared to promote EGFR activation. Parasites defective in EGF-MICs (MIC1 ko, deficient in MIC1 and secretion of MIC6; MIC3 ko, deficient in MIC3; and MIC1-3 ko, deficient in MIC1, MIC3 and secretion of MIC6) caused impaired EGFR-Akt activation and recombinant EGF-MICs (MIC3 and MIC6) caused EGFR-Akt activation. In cells treated with autophagy stimulators (CD154, rapamycin) EGFR signaling inhibited LC3 accumulation around the parasite. Moreover, increased LC3 accumulation and parasite killing were noted in CD154-activated cells infected with MIC1-3 ko parasites. Finally, recombinant MIC3 and MIC6 inhibited parasite killing triggered by CD154 particularly against MIC1-3 ko parasites. Thus, our findings identified EGFR activation as a strategy used by T. gondii to maintain the non-fusogenic nature of the parasitophorous vacuole and suggest that EGF-MICs have a novel role in affecting signaling in host cells to promote parasite survival

Variations of Plasmid Content in Rickettsia felis

Background: Since its first detection, characterization of R. felis has been a matter of debate, mostly due to the contamination of an initial R. felis culture by R. typhi. However, the first stable culture of R. felis allowed its precise phenotypic and genotypic characterization, and demonstrated that this species belonged to the spotted fever group rickettsiae. Later, its genome sequence revealed the presence of two forms of the same plasmid, physically confirmed by biological data. In a recent article, Gillespie et al. ( PLoS One. 2007; 2( 3): e266.) used a bioinformatic approach to refute the presence of the second plasmid form, and proposed the creation of a specific phylogenetic group for R. felis. Methodology/ Principal Findings: In the present report, we, and five independent international laboratories confirmed unambiguously by PCR the presence of two plasmid forms in R. felis strain URRWXCal(2)(T), but observed that the plasmid content of this species, from none to 2 plasmid forms, may depend on the culture passage history of the studied strain. We also demonstrated that R. felis does not cultivate in Vero cells at 37 degrees C but generates plaques at 30 degrees C. Finally, using a phylogenetic study based on 667 concatenated core genes, we demonstrated the position of R. felis within the spotted fever group. Significance: We demonstrated that R. felis, which unambiguously belongs to the spotted fever group rickettsiae, may contain up to two plasmid forms but this plasmid content is unstable