234 research outputs found
Some remarks on Bell's Inequality tests
We emphasize the difficulties of an experiment that can definitely
discriminate between local realistic hidden variables theories and quantum
mechanics using the Bell CHSH inequalities and a real measurement apparatus. In
particular we analyze some examples in which the noise in real instruments can
alter the experimental results, and the nontrivial problem to find a real "fair
sample" of particles to test the inequalities.Comment: 12 pages, Latex, 2 figures, to be published in Europhysics Letter
Oscillating universes as eigensolutions of cosmological Schrödinger equation
We propose a cosmological model which could explain, in a very natural way, the apparently periodic structures of the universe, as revealed in a series of recent observations. Our point of view is to reduce the cosmological Friedman--Einstein dynamical system to a sort of Schrödinger equation whose bound eigensolutions are oscillating functions. Taking into account the cosmological expansion, the large scale periodic structure could be easily recovered considering the amplitudes and the correlation lengths of the galaxy clusters
Composite scaffold obtained by electro-hydrodynamic technique for infection prevention and treatment in bone repair
Bone infection is a devastating condition resulting from implant or orthopaedic surgery. Therapeutic strategies are extremely complicated and may result in serious side effects or disabilities. The development of enhanced 3D scaffolds, able to promote efficient bone regeneration, combined with targeted antibiotic release to prevent bacterial colonization, is a promising tool for the successful repair of bone defects. Herein, polymeric electrospun scaffolds composed of polycaprolactone (PCL) nanofibres decorated with poly(lactic-co-glycolic acid) (PLGA) particles loaded with rifampicin were fabricated to achieve local and sustained drug release for more efficient prevention and treatment of infection. The release profile showed an initial burst of rifampicin in the first six hours, enabling complete elimination of bacteria. Sustained and long-term release was observed until the end of the experiments (28 days), facilitating a prolonged effect on the inhibition of bacterial growth, which is in agreement with the common knowledge concerning the acidic degradation of the microparticles. In addition, bactericidal effects against gram negative (Escherichia coli) and gram positive (Staphylococcus aureus) bacteria were demonstrated at concentrations of released rifampicin up to 58 ppm after 24 h, with greater efficacy against S. aureus (13 ppm vs 58 ppm for E. coli). Cell morphology and cytocompatibility studies highlighted the suitability of the fabricated scaffolds to support cell growth, as well as their promising clinical application for bone regeneration combined with prevention or treatment of bacterial infection
Thin shell quantization in Weyl spacetime
We study the problem of quantization of thin shells in a Weyl-Dirac theory by deriving a Wheeler-DeWitt equation from the dynamics. Solutions are found which have interpretations in both cosmology and particle physics
Oscillating universes as eigensolutions of cosmological Schr\"odinger equation
We propose a cosmological model which could explain, in a very natural way,
the apparently periodic structures of the universe, as revealed in a series of
recent observations. Our point of view is to reduce the cosmological
Friedman--Einstein dynamical system to a sort of Schr\"odinger equation whose
bound eigensolutions are oscillating functions. Taking into account the
cosmological expansion, the large scale periodic structure could be easily
recovered considering the amplitudes and the correlation lengths of the galaxy
clusters.Comment: 12 pages, Latex, submitted to Int. Jou. of Theor. Phy
Massive Scalar Particles in a Modified Schwarzschild Geometry
Massive, spinless bosons have vanishing probability of reaching the sphere r=2M from the region r>2M when the original Schwarzschild metric is modified by maximal acceleration corrections
Initiation of an anal cancer screening in HIV+MSM: results of cytology, biopsy and determination of risk factors
Incidence of anal cancer is increasing and risk of anal cancer is higher in MSM, especially if they are HIV+. European guidelines for treatment of HIV-infected adults recommend anal cancer screening by digital rectal exam±Pap test with anuscopy if Pap test is abnormal. A systematic anal cancer screening in HIV+MSM with anal cytology (Pap smears) was established in June 2011 in our reference centre in Brussels. If anal cytology was abnormal, high-resolution anuscopy (HRA) with biopsy was performed. 353 MSM HIV+were screened by anal smears between June 2011 and May 2012. 90% were Caucasians, median age was 44.5 years, 83% were on HAART and 74% had an undetectable viral load, median CD4 was 632/µl and 33% had a nadir CD4<200. Thirty-three (9.3%) were excluded because of poor quality. Cytology was abnormal in 46% of the 320 remaining patients: high-grade squamous intraepithelial lesion (HSIL) 3%, low-grade squamous intraepithelial lesion (LSIL) 24%, atypical squamous cells of undetermined significance (ASC-US) 16%, and atypical squamous cells / cannot rule out a high-grade lesion (ASC-H) 3%. Viral load (VL) was more frequently undetectable (82% vs 64%, p=0.0003) and median duration of HAART was longer (111 vs 61 months, p=0.0145) in patients with normal cytology. 80 HRA with biopsies have been performed. 12.5% were normal, 44% showed anal intraepithelial neoplasia (AIN) 1, 24% AIN 2 and 19% AIN 3. For this analysis, high-grade AIN (2 and 3) were put together (AIN 2+). Among patients with AIN 2+(n=33), cytology had showed 8 (24%) ASC-US, 3 (9%) ASC-H, 19 (57%) LSIL, 3 (9%) HSIL. When patients with normal cytology or normal biopsy and patients with AIN 2+were compared, the only significant risk factor found for AIN 2+was a nadir CD4<100/µl (32% of the patients with AIN 2+vs 14% in patients with normal smear, p=0.0073). Anal precancerous lesions are frequent and at different stages. Among 46% abnormal cytology, 87% had abnormal biopsy including half AIN 2+.Cytology±biopsy is the only way to detect those lesions and should be performed systematically in HIV+MSM. Risk factor for AIN2+was a nadir CD4<100/µl. A normal cytology was associated with an undetectable VL and a longer duration of HAART. Those results provide further argument for early initiation of HAART
Is there a relationship between the mass of a SMBH and the kinetic energy of its host elliptical galaxy?
We use a restricted sample of elliptical galaxies, whose kinematical
parameters inside the semimajor axis were calculated correcting the effect of
the integration of the light along the line of sight, in order to analyze a
possible relationship between the mass of a Supermassive Black Hole (SMBH) and
the kinetic energy of random motions in the host galaxy. We find with depending on
the different fitting methods and samples used. This result could be
interpreted as a new fundamental relationship or as a new way to explain the
old law. In fact, the relations of the velocity dispersion
both with the mass of the SMBH () and with the
mass of the host galaxy () induce us to infer an
almost direct proportionality: . A similar
relationship is found for the total kinetic energy involving the rotation
velocity too.Comment: 16 pages, 3 figures, 1 Table, accepted for publication in IJMP
Effects of adding saturated fat to diets with sorghum-based dried distillers grains with solubles on growth performance and carcass characteristics in finishing pigs
Two experiments were conducted to determine the effects of adding sources of saturated fat to diets with sorghum-based dried distillers grains with solubles (DDGS). For Exp. 1, 112 barrows (initially 140 lb) were used in a 69-d growth assay with 7 pigs per pen and 4 pens per treatment. Treatments were a corn-soybean meal-based control and diets having 40% sorghum-based DDGS (U.S. En-ergy Partners, Russell, KS) without and with 5% added tallow or palm oil. Feed and water were consumed on an ad libitum basis until pigs were slaughtered (average BW 283 lb) to allow collection of carcass data and jowl samples. Fatty acid composition of jowl samples was used to calculate iodine value (IV) as an indicator of carcass fat firmness. Overall (d 0 to 69), the corn-soybean control supported greater ADG and ADFI (P 0.9) compared with the DDGS treatments. Adding 5% beef tallow and palm oil to diets with DDGS improved overall F/G (P 0.14). Changes in IV indicated softer fat in pigs fed DDGS (P 0.14) compared with DDGS treatments. Adding fat sources to diets with DDGS tended to improve (P < 0.06) overall F/G, and coconut oil improved F/G compared with stearic acid (P < 0.001). Pigs fed the control diet had greater (P < 0.05) HCW than pigs fed the DDGS treatments. Pigs fed the control diet had lower IV and greater firmness score than pigs fed diets with added DDGS (P < 0.02). Adding fat sources to diets with DDGS improved these estimates of carcass firmness and tip to tip distance for suspended bellies (P < 0.001); coconut oil had a much greater effect than stearic acid (P < 0.001). In conclusion, adding beef tallow, palm oil, and coconut oil to diets with 40% DDGS improved efficiency of gain in finishing pigs. However, only coconut oil restored carcass firmness to levels at or above a corn-soybean diet without DDGS
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