Tidal tensors in the description of gravity and electromagnetism

In 2008-2009, F. Costa and C. Herdeiro proposed a new gravito-electromagnetic analogy, based on tidal tensors. We show that connections on the tangent bundle of the space-time manifold can help not only in finding a covnenient geometrization of their ideas, but also a common mathematical description of the main equations of gravity and electromagnetism.Comment: submitted to: Journal of Nonlinear Mathematical Physic

Jacobi stability of the vacuum in the static spherically symmetric brane world models

We analyze the stability of the structure equations of the vacuum in the brane world models, by using both the linear (Lyapunov) stability analysis, and the Jacobi stability analysis, the Kosambi-Cartan-Chern (KCC) theory. In the brane world models the four dimensional effective Einstein equations acquire extra terms, called dark radiation and dark pressure, respectively, which arise from the embedding of the 3-brane in the bulk. Generally, the spherically symmetric vacuum solutions of the brane gravitational field equations, have properties quite distinct as compared to the standard black hole solutions of general relativity. We close the structure equations by assuming a simple linear equation of state for the dark pressure. In this case the vacuum is Jacobi stable only for a small range of values of the proportionality constant relating the dark pressure and the dark radiation. The unstable trajectories on the brane behave chaotically, in the sense that after a finite radial distance it would be impossible to distinguish the trajectories that were very near each other at an initial point. Hence the Jacobi stability analysis offers a powerful method for constraining the physical properties of the vacuum on the brane.Comment: 21 pages, 3 figures, accepted for publication in PR

A BAC Transgene Expressing Human CFTR under Control of Its Regulatory Elements Rescues Cftr Knockout Mice

Small-molecule modulators of cystic fibrosis transmembrane conductance regulator (CFTR) biology show promise in the treatment of cystic fibrosis (CF). A Cftr knockout (Cftr KO) mouse expressing mutants of human CFTR would advance in vivo testing of new modulators. A bacterial artificial chromosome (BAC) carrying the complete hCFTR gene including regulatory elements within 40.1 kb of DNA 5? and 25 kb of DNA 3? to the gene was used to generate founder mice expressing hCFTR. Whole genome sequencing indicated a single integration site on mouse chromosome 8 (8qB2) with ~6 gene copies. hCFTR+ offspring were bred to murine Cftr KO mice, producing hCFTR+/mCftr? (H+/m?) mice, which had normal survival, growth and goblet cell function as compared to wild-type (WT) mice. Expression studies showed hCFTR protein and transcripts in tissues typically expressing mCftr. Functionally, nasal potential difference and large intestinal short-circuit (Isc) responses to cAMP stimulation were similar in magnitude to WT mice, whereas small intestinal cAMP ?Isc responses were reduced. A BAC transgenic mouse with functional hCFTR under control of its regulatory elements has been developed to enable the generation of mouse models of hCFTR mutations by gene editing for in vivo testing of new CF therapies

Non-physical consequences of the Muffin-tin-type intra-molecular potential

We demonstrate using a simple model that in the frame of muffin-tin - like potential non-physical peculiarities appear in molecular photoionization cross-sections that are a consequence of jumps in the potential and its first derivative at some radius. The magnitude of non-physical effects is of the same order as the physical oscillations in the cross-section of a two-atomic molecule. The role of the size of these jumps is illustrated by choosing three values of it. The results obtained are connected to the studied previously effect of non-analytical behavior as a function of r the potential V(r)acting upon a particle on its photoionization cross-section. In reality, such potential has to be analytic in magnitude and first derivative function in distance. Introduction of non-analytic features in model potential leads to non-physical features in the corresponding cross-section - oscillations, additional maxima etc.Comment: 11 pages, 5 figure

Effects of platelet rich plasma (PRP) on human gingival fibroblast, osteoblast and periodontal ligament cell behaviour

The use of platelet rich plasma (PRP, GLO) has been used as an adjunct to various regenerative dental procedures. The aim of the present study was to characterize the influence of PRP on human gingival fibroblasts, periodontal ligament (PDL) cells and osteoblast cell behavior in vitro

Nonlinear stability analysis of the Emden-Fowler equation

In this paper we qualitatively study radial solutions of the semilinear elliptic equation $\Delta u + u^n = 0$ with $u(0)=1$ and $u'(0)=0$ on the positive real line, called the Emden-Fowler or Lane-Emden equation. This equation is of great importance in Newtonian astrophysics and the constant $n$ is called the polytropic index. By introducing a set of new variables, the Emden-Fowler equation can be written as an autonomous system of two ordinary differential equations which can be analyzed using linear and nonlinear stability analysis. We perform the study of stability by using linear stability analysis, the Jacobi stability analysis (Kosambi-Cartan-Chern theory) and the Lyapunov function method. Depending on the values of $n$ these different methods yield different results. We identify a parameter range for $n$ where all three methods imply stability.Comment: 12 pages; new reference added; 3 new references added; fully revised versio

Evaluation of a candidate breast cancer associated SNP in ERCC4 as a risk modifier in BRCA1 and BRCA2 mutation carriers. Results from the Consortium of Investigators of Modifiers of BRCA1/BRCA2 (CIMBA)

Background: In this study we aimed to evaluate the role of a SNP in intron 1 of the ERCC4 gene (rs744154), previously reported to be associated with a reduced risk of breast cancer in the general population, as a breast cancer risk modifier in BRCA1 and BRCA2 mutation carriers. Methods: We have genotyped rs744154 in 9408 BRCA1 and 5632 BRCA2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA) and assessed its association with breast cancer risk using a retrospective weighted cohort approach. Results: We found no evidence of association with breast cancer risk for BRCA1 (per-allele HR: 0.98, 95% CI: 0.93–1.04, P=0.5) or BRCA2 (per-allele HR: 0.97, 95% CI: 0.89–1.06, P=0.5) mutation carriers. Conclusion: This SNP is not a significant modifier of breast cancer risk for mutation carriers, though weak associations cannot be ruled out. A Osorio1, R L Milne2, G Pita3, P Peterlongo4,5, T Heikkinen6, J Simard7, G Chenevix-Trench8, A B Spurdle8, J Beesley8, X Chen8, S Healey8, KConFab9, S L Neuhausen10, Y C Ding10, F J Couch11,12, X Wang11, N Lindor13, S Manoukian4, M Barile14, A Viel15, L Tizzoni5,16, C I Szabo17, L Foretova18, M Zikan19, K Claes20, M H Greene21, P Mai21, G Rennert22, F Lejbkowicz22, O Barnett-Griness22, I L Andrulis23,24, H Ozcelik24, N Weerasooriya23, OCGN23, A-M Gerdes25, M Thomassen25, D G Cruger26, M A Caligo27, E Friedman28,29, B Kaufman28,29, Y Laitman28, S Cohen28, T Kontorovich28, R Gershoni-Baruch30, E Dagan31,32, H Jernström33, M S Askmalm34, B Arver35, B Malmer36, SWE-BRCA37, S M Domchek38, K L Nathanson38, J Brunet39, T Ramón y Cajal40, D Yannoukakos41, U Hamann42, HEBON37, F B L Hogervorst43, S Verhoef43, EB Gómez García44,45, J T Wijnen46,47, A van den Ouweland48, EMBRACE37, D F Easton49, S Peock49, M Cook49, C T Oliver49, D Frost49, C Luccarini50, D G Evans51, F Lalloo51, R Eeles52, G Pichert53, J Cook54, S Hodgson55, P J Morrison56, F Douglas57, A K Godwin58, GEMO59,60,61, O M Sinilnikova59,60, L Barjhoux59,60, D Stoppa-Lyonnet61, V Moncoutier61, S Giraud59, C Cassini62,63, L Olivier-Faivre62,63, F Révillion64, J-P Peyrat64, D Muller65, J-P Fricker65, H T Lynch66, E M John67, S Buys68, M Daly69, J L Hopper70, M B Terry71, A Miron72, Y Yassin72, D Goldgar73, Breast Cancer Family Registry37, C F Singer74, D Gschwantler-Kaulich74, G Pfeiler74, A-C Spiess74, Thomas v O Hansen75, O T Johannsson76, T Kirchhoff77, K Offit77, K Kosarin77, M Piedmonte78, G C Rodriguez79, K Wakeley80, J F Boggess81, J Basil82, P E Schwartz83, S V Blank84, A E Toland85, M Montagna86, C Casella87, E N Imyanitov88, A Allavena89, R K Schmutzler90, B Versmold90, C Engel91, A Meindl92, N Ditsch93, N Arnold94, D Niederacher95, H Deißler96, B Fiebig97, R Varon-Mateeva98, D Schaefer99, U G Froster100, T Caldes101, M de la Hoya101, L McGuffog49, A C Antoniou49, H Nevanlinna6, P Radice4,5 and J Benítez1,3 on behalf of CIMB

Electrochemical Oxidation and Sensing of Methylamine Gas in Room Temperature Ionic Liquids

The electrochemical behaviour of methylamine gas in several room temperature ionic liquids (RTILs), [C2mim][NTf2], [C4mim][NTf2], [C6mim][FAP], [C4mpyrr][NTf2], [C4mim][BF4], and [C4mim][PF6] has been investigated on a Pt microelectrode using cyclic voltammetry. A broad oxidation wave at approximately 3 V, two reduction peaks and another oxidation peak was observed. A complicated mechanism is predicted based on the voltammetry obtained, with ammonia gas as a likely by-product. The currents obtained suggest that methylamine has a high solubility in RTILs, which is important for gas sensing applications. The analytical utility of methylamine was then studied in [C4mpyrr][NTf2] and [C2mim][NTf2]. A linear calibration graph with an R2 value of 0.99 and limits of detection of 33 and 34 ppm were obtained respectively, suggesting that RTILs are favourable non-volatile solvents for the electrochemical detection of highly toxic methylamine gas

Germline mutations in CDH1 are infrequent in women with early-onset or familial lobular breast cancers

BACKGROUND: Germline mutations in CDH1 are associated with hereditary diffuse gastric cancer; lobular breast cancer also occurs excessively in families with such condition. METHOD: To determine if CDH1 is a susceptibility gene for lobular breast cancer in women without a family history of diffuse gastric cancer, germline DNA was analysed for the presence of CDH1 mutations in 318 women with lobular breast cancer who were diagnosed before the age of 45 years or had a family history of breast cancer and were not known, or known not, to be carriers of germline mutations in BRCA1 or BRCA2. Cases were ascertained through breast cancer registries and high-risk cancer genetic clinics (Breast Cancer Family Registry, the kConFab and a consortium of breast cancer genetics clinics in the United States and Spain). Additionally, Multiplex Ligation-dependent Probe Amplification was performed for 134 cases to detect large deletions. RESULTS: No truncating mutations and no large deletions were detected. Six non-synonymous variants were found in seven families. Four (4/318 or 1.3%) are considered to be potentially pathogenic through in vitro and in silico analysis. CONCLUSION: Potentially pathogenic germline CDH1 mutations in women with early-onset or familial lobular breast cancer are at most infrequent