1,808 research outputs found

    Edge waves and localisation in lattices containing tilted resonators

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    The paper presents the study of waves in a structured geometrically chiral solid. A special attention is given to the analysis of the Bloch-Floquet waves in a doubly periodic high-contrast lattice containing tilted resonators. Dirac-like dispersion of Bloch waves in the structure is identified, studied and applied to wave-guiding and wave-defect interaction problems. The work is extended to the transmission problems and models of fracture, where localisation and edge waves occur. The theoretical derivations are accompanied with numerical simulations and illustrations

    Pasta-making properties of the new durum wheat variety biensur suitable for the northern mediterranean environment

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    Industrial pasta is commonly made from mixtures of semolina from different durum wheat varieties, and there is a very low market presence of mono-varietal pasta from local, short supply chains. In this work, dough rheological properties and pasta quality traits of the new durum wheat cv. Biensur, which has a high HMW/LMW-GS ratio, were evaluated with a view to developing short-chain, mono-varietal pasta production in NE Italy. Chemical and sensory analyses on short-cut pasta, viz. tubetti, made with semolina from cv. Biensur at two drying temperatures revealed that it has good technological characteristics and stability, excellent cooking and sensory properties, and is comparable to the high-quality commercial reference cv. Aureo. We conclude that Biensur provides farmers and traders with new market opportunities and offers improvements to the environmental and economic sustainability of the durum wheat chain

    Elevated cystatin-C concentration is associated with progression to prediabetes: the Western New York Study

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    OBJECTIVE – We conducted a nested case-control investigation to examine if elevated baseline concentrations of cystatin-C predicted progression from normoglycaemia to prediabetes over 6 years of follow-up from the Western New York Health Study. RESEARCH DESIGN AND METHODS – 1,455 participants from the Western New York Health Study, free of type 2 diabetes and known cardiovascular disease at baseline (1996-2001), were reexamined in 2002-2004. An incident case of prediabetes was defined as one with fasting glucose below 100 mg/dl at the baseline examination and ≄ 100 mg/dl and ≀ 125 mg/dl at the follow-up examination. All cases (n=91) were matched 1:3 to control participants based upon sex, race/ethnicity and year of study enrollment. All controls had fasting glucose levels < 100 mg/dl at both baseline and follow-up examinations. Cystatin-C concentrations and the urinary albumin to creatinine ratio were measured from frozen (-196 CÂș) baseline blood and urine samples. Serum creatinine concentrations were available from the baseline examination. RESULTS –Multivariate conditional logistic regression analyses adjusted for age, baseline glucose level, HOMA-IR, body mass index, hypertension, eGFR, cigarette smoking, and alcohol use revealed a significantly increased risk of progression to prediabetes among those with elevated baseline concentrations of cystatin-C (Odds Ratio, 95% CI: 3.04, 1.34, 6.89) (upper quintile vs. the remainder). Results of secondary analyses that considered hs-CRP, IL-6, E-selectin, or sICAM did not alter these results. CONCLUSIONS - These results suggest that early renal impairment indexed with cystatin-C imparted a three-fold excess risk of progression to prediabetes in this study population. Recent evidence from randomized clinical trials (1,2) among people with prediabetes have provided convincing evidence that early intervention can significantly delay or prevent the progression to type 2 diabetes. The identification of those with prediabetes is assuming greater importance (3) especially in light of the fact that approximately 35 million adults aged 40-74 years old in the United States have prediabetes defined as impaired fasting glucose (4). Microalbuminuria occurs frequently in nondiabetic subjects and places them at increased risk for cardiovascular disease (5-7). The mechanisms behind this observation are poorly understood, however. Albuminuria may reflect underlying vascular damage (8), hypertension (9, 10) endothelial dysfunction (11, 12) and/or low-grade inflammation (13). A large percentage of type 2 individuals pass through a period of prediabetes (14) and may experience early renal dysfunction e.g., a glomerular filtration rate (GFR) above 60 ml/minute per 1.73m2. Currently used estimating equations are poor at identifying early renal impairment and better indices are of great interest (15, 16). Recently, several studies have suggested that cystatin-C levels may be a more sensitive marker of early renal impairment than either albuminuria or serum creatinine concentration (17-20). Therefore, a better understanding of a putative role for cystatin-C in the etiology of prediabetes could shed light on the renal/heart disease connection (21). Given the reported superiority of cystatin C over conventional measures of renal function, we hypothesized that cystatin-C would predict progression to prediabetes independent of serum creatinine or estimated GFR. We also investigated the role of intervening mechanisms including hypertension, insulin resistance, endothelial dysfunction and inflammation

    Dynamical analysis of the cluster pair: A3407 + A3408

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    We carried out a dynamical study of the galaxy cluster pair A3407 \& A3408 based on a spectroscopic survey obtained with the 4 meter Blanco telescope at the CTIO, plus 6dF data, and ROSAT All-Sky-Survey. The sample consists of 122 member galaxies brighter than mR=20m_R=20. Our main goal is to probe the galaxy dynamics in this field and verify if the sample constitutes a single galaxy system or corresponds to an ongoing merging process. Statistical tests were applied to clusters members showing that both the composite system A3407 + A3408 as well as each individual cluster have Gaussian velocity distribution. A velocity gradient of ∌847±114\sim 847\pm 114 km  s−1\rm km\;s^{-1} was identified around the principal axis of the projected distribution of galaxies, indicating that the global field may be rotating. Applying the KMM algorithm to the distribution of galaxies we found that the solution with two clusters is better than the single unit solution at the 99\% c.l. This is consistent with the X-ray distribution around this field, which shows no common X-ray halo involving A3407 and A3408. We also estimated virial masses and applied a two-body model to probe the dynamics of the pair. The more likely scenario is that in which the pair is gravitationally bound and probably experiences a collapse phase, with the cluster cores crossing in less than ∌\sim1 h−1h^{-1} Gyr, a pre-merger scenario. The complex X-ray morphology, the gas temperature, and some signs of galaxy evolution in A3408 suggests a post-merger scenario, with cores having crossed each other ∌1.65h−1\sim 1.65 h^{-1}Gyr ago, as an alternative solution.Comment: 17 pages, 12 figures, submitted to MNRAS, accepted 2016 May 9. Received 2016 May 9; in original form 2016 April 1

    EXPERIMENTAL STUDY OF THE INLET FLOW IN A NON-PREMIXED COMBUSTION CHAMBER

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    The evaluation, validation and development of the models used in computation fluid dynamics requires the availability of experimental data for which the boundary conditions, especially the conditions of the inlet flow, are well defined. Laser diagnostics techniques provide experimental data used in computational fluid dynamics and are a powerful tool for measurements of the mean properties and fluctuations of the turbulent flow because they are non-intrusive methods, with high repetition rate and high spatial and temporal resolution. Therefore, in the present work an experimental study of the inlet flow (inert and combusting flows) in a non-premixed combustion chamber is presented. The velocity measurements were carried out using a laser Doppler velocimeter at the entrance region of the combustion chamber. An asymmetry on the mean flow and an increase on the total velocity fluctuations with the increase of the equivalence ratio was observed. The major effect on the increase of the equivalence ratio was a presence of a coherent movement on large scales associated to the flame brush dynamics

    High rate locally-correctable and locally-testable codes with sub-polynomial query complexity

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    In this work, we construct the first locally-correctable codes (LCCs), and locally-testable codes (LTCs) with constant rate, constant relative distance, and sub-polynomial query complexity. Specifically, we show that there exist binary LCCs and LTCs with block length nn, constant rate (which can even be taken arbitrarily close to 1), constant relative distance, and query complexity exp⁥(O~(log⁥n))\exp(\tilde{O}(\sqrt{\log n})). Previously such codes were known to exist only with Ω(nÎČ)\Omega(n^{\beta}) query complexity (for constant ÎČ>0\beta > 0), and there were several, quite different, constructions known. Our codes are based on a general distance-amplification method of Alon and Luby~\cite{AL96_codes}. We show that this method interacts well with local correctors and testers, and obtain our main results by applying it to suitably constructed LCCs and LTCs in the non-standard regime of \emph{sub-constant relative distance}. Along the way, we also construct LCCs and LTCs over large alphabets, with the same query complexity exp⁥(O~(log⁥n))\exp(\tilde{O}(\sqrt{\log n})), which additionally have the property of approaching the Singleton bound: they have almost the best-possible relationship between their rate and distance. This has the surprising consequence that asking for a large alphabet error-correcting code to further be an LCC or LTC with exp⁥(O~(log⁥n))\exp(\tilde{O}(\sqrt{\log n})) query complexity does not require any sacrifice in terms of rate and distance! Such a result was previously not known for any o(n)o(n) query complexity. Our results on LCCs also immediately give locally-decodable codes (LDCs) with the same parameters

    FEROS Abundance Analysis of 21 Bulgelike SMR Stars

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    We analyze a sample of 21 super-metal-rich (SMR) stars, using high-resolution Ă©chelle spectra obtained with the Fiber-fed Extended Range Optical Spectrograph at the 1.5m ESO telescope. The metallicities are in the range 0.07 ≀ [Fe/H] ≀ 0.45, 3 of them in common with PompĂ©ia et al. (2009). Geneva photometry, astrometric data from Hipparcos, and radial velocities from CORAVEL are available for these stars. The peculiar kinematics suggests the thin disk close to the bulge as the probable birthplace of these stars (Grenon 1999). From Hipparcos data, it appears that the turnoff of this population indicates an age of 10-11 Gyr (Grenon 1999). Detailed analysis of the sample stars is carried out, and atmospheric parameters are derived from spectroscopic and photometric determinations. Oxygen abundances of these stars are derived, and [O/Fe] overabundances up to +0.35 are foun

    Infections of the upper respiratory tract and counting of leukocytes in volleyball athletes

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    Submaximal and regular exercise tends to improve the immune response. On the other hand, athletes have a higher incidence of infection of the upper respiratory tract (URTI). The objective of the present study was to correlate the total episodes of URTI with the relative count of circulating neutrophils and lymphocytes in volleyball female athletes, aged 18.92±0.76 years (n=12), within the periods of training. The blood was collected at the end of the periods: Pre-competitive (M1), Competitive-I (M2) and Competitive-II (M3) and the URTI weekly. The athletes participated of 30 weeks of training and competitions. The Pearson correlation coefficient was used, p≀0.05. The results showed moderate to high correlations with 0.8 (p=0.001) and -0.76 (p=0.004) in M1; 0.68 (p=0.014) and -0.59 (p=0.042) in M2; followed by no significant correlations of 0.35 and -0.62 in M3, respectively for neutrophils and lymphocytes when coupled with URTI. The increased number of neutrophils and decreased number of lymphocytes were correlated to URTI and may be useful tools during long time training periods to prevent overload induced immunesuppression

    On the NP-Hardness of Approximating Ordering Constraint Satisfaction Problems

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    We show improved NP-hardness of approximating Ordering Constraint Satisfaction Problems (OCSPs). For the two most well-studied OCSPs, Maximum Acyclic Subgraph and Maximum Betweenness, we prove inapproximability of 14/15+Ï”14/15+\epsilon and 1/2+Ï”1/2+\epsilon. An OCSP is said to be approximation resistant if it is hard to approximate better than taking a uniformly random ordering. We prove that the Maximum Non-Betweenness Problem is approximation resistant and that there are width-mm approximation-resistant OCSPs accepting only a fraction 1/(m/2)!1 / (m/2)! of assignments. These results provide the first examples of approximation-resistant OCSPs subject only to P ≠\neq \NP
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