Geodesics of Hayward black hole surrounded by quintessence

Basing on the ideas used by Kiselev, we study the Hayward black hole surrounded by quintessence. By setting for the quintessence state parameter at the special case of $\omega=-\frac{2}{3}$, using the metric of the black hole surrounded by quintessence and the definition of the effective potential, we analyzed in detail the null geodesics for different energies. We also analyzed the horizons of the Hayward black hole surrounded by quintessence as well as the shadow of the black hole

New insights in bacillus subtillis levansucrase mechanism and applications

B. subtilis levansucrase (SacB) is a widely studied glycoside hydrolase from Family 68 family. Although reports on SacB properties date back to the 70’s (Chambert & Gonzy-Tréboul, 1976), questions regarding levan synthesis mechanism are still open. These questions refer to the factors influencing reaction specificity, including the effect of sucrose and levan hydrolysis, product structure and levan molecular weight. In this conference we review recent findings regarding the modulating effect of SacB concentration on levan molecular weight distribution (Porras-Domínguez et al., 2015; Raga-Carbajal et al., 2016). In effect, we demonstrated that high enzyme concentrations (\u3e1.0 µM), direct levan synthesis exclusively to low molecular weight products (av 7.6 KDa), while low enzyme concentrations (\u3c 0.1µM) favor the synthesis of a high molecular weight levan fraction (\u3e2000 kDa). From a detailed HPAEC-PAD analysis of product evolution, a shift from a clear non-processive elongation mechanism at high protein concentrations to a -most likely- processive mechanism when low protein concentrations are used in the reaction. Trough calorimetric experiments we demonstrate that these changes in enzyme performance do not involve protein-protein interactions (Raga-Carbajal et al., 2016). We demonstrated, through an extensive characterization of the levan hydrolysis reaction by SacB, that the wide diversity of products derives also from fructosyl transfer to free sugars available from sucrose and levan hydrolysis. Actually, levan is an efficient fructosyl donor for fructosylation reactions, in which FOS such as levanbiose, inulobiose, blastose, …, are formed (Méndez-Lorenzo et al., 2015). The efficiency of SacB fructosylation with levan as donor was applied for the synthesis of blastose, a sucrose analogue with potential prebiotic properties. For this reaction, fructose was transferred to trehalose to produce a (2-6) fructosylated trehalose, which was later hydrolysed by trehalase to yield blastose (Miranda-Molina et al, 2017). Up to now there is not an efficient enzyme for the synthesis of levan-type FOS, in spite of intensive efforts to modify SacB or other levansucrases specificity by site directed mutagenesis. For this purpose, after a complete characterization of a combined bi-enzymatic reaction between SacB and an endolevanase produced by B.licheniformis. (LevB1) (Porras-Domínguez et al., 2014) we designed a fusion enzyme containing both activities. This fusion enzyme is able to produce levan-type FOS from sucrose, with molecular weights in the range of DP2 to DP10 including mainly 1-kestose, 6-kestose, neokestose, levanbiose and blastose, with 40% w/w yields. Chambert, R., & Gonzy-Tréboul, G. (1976). European Journal of Biochemistry / FEBS, 62(1), 55–64. Méndez-Lorenzo, L., Porras-Domínguez, J. R., Raga-Carbajal, E., Olvera, C., Rodríguez-Alegría, M. E., Carrillo-Nava, E.. López Munguía, A. (2015). PLoS ONE, 10(11), 1–15. Miranda-Molina, A., Castillo, E., & Lopez Munguia, A. (2017). Food Chemistry, 227, 202–210. Porras-Domínguez, J. R., Ávila-Fernández, Á., Miranda-Molina, A., Rodríguez-Alegría, M. E., & Munguía, A. L. (2015). Carbohydrate Polymers, 132(October), 338–344. Porras-Domínguez, J. R., Ávila-Fernández, Á., Rodríguez-Alegría, M. E., Miranda-Molina, A., Escalante, A., González-Cervantes, R., López Munguía, A. (2014). Process Biochemistry, 49(5), 783–790. Raga-Carbajal, E., Carrillo-Nava, E., Costas, M., Porras-Dominguez, J., López-Munguía, A., & Olvera, C. (2016). Glycobiology, 26(4), 377–385

Beyond conventional factorization: Non-Hermitian Hamiltonians with radial oscillator spectrum

The eigenvalue problem of the spherically symmetric oscillator Hamiltonian is revisited in the context of canonical raising and lowering operators. The Hamiltonian is then factorized in terms of two not mutually adjoint factorizing operators which, in turn, give rise to a non-Hermitian radial Hamiltonian. The set of eigenvalues of this new Hamiltonian is exactly the same as the energy spectrum of the radial oscillator and the new square-integrable eigenfunctions are complex Darboux-deformations of the associated Laguerre polynomials.Comment: 13 pages, 7 figure

Non-existence of stationary two-black-hole configurations: The degenerate case

In a preceding paper we examined the question whether the spin-spin repulsion and the gravitational attraction of two aligned sub-extremal black holes can balance each other. Based on the solution of a boundary value problem for two separate (Killing-) horizons and a novel black hole criterion we were able to prove the non-existence of the equilibrium configuration in question. In this paper we extend the non-existence proof to extremal black holes.Comment: 18 pages, 2 figure

Visual 3-D SLAM from UAVs

The aim of the paper is to present, test and discuss the implementation of Visual SLAM techniques to images taken from Unmanned Aerial Vehicles (UAVs) outdoors, in partially structured environments. Every issue of the whole process is discussed in order to obtain more accurate localization and mapping from UAVs flights. Firstly, the issues related to the visual features of objects in the scene, their distance to the UAV, and the related image acquisition system and their calibration are evaluated for improving the whole process. Other important, considered issues are related to the image processing techniques, such as interest point detection, the matching procedure and the scaling factor. The whole system has been tested using the COLIBRI mini UAV in partially structured environments. The results that have been obtained for localization, tested against the GPS information of the flights, show that Visual SLAM delivers reliable localization and mapping that makes it suitable for some outdoors applications when flying UAVs

Optical potentials using resonance states in Supersymmetric Quantum Mechanics

Complex potentials are constructed as Darboux-deformations of short range, radial nonsingular potentials. They behave as optical devices which both refracts and absorbs light waves. The deformation preserves the initial spectrum of energies and it is implemented by means of a Gamow-Siegert function (resonance state). As straightforward example, the method is applied to the radial square well. Analytical derivations of the involved resonances show that they are `quantized' while the corresponding wave-functions are shown to behave as bounded states under the broken of parity symmetry of the related one-dimensional problem.Comment: 16 pages, 6 figures, 1 tabl

Adopting sustainability competence-based education in academic disciplines: Insights from 13 higher education institutions

Higher Education Institutions (HEIs) have been incorporating sustainability into education and curricula, where recent research has focussed on sustainability competences, pedagogical approaches, and how to connect them, generally on a single HEI. The process of integrating sustainability into education based on curricula assessment has been explained using adoption of innovations; and has the potential to explain the process of developing competences through pedagogical approaches. The aim of this paper is to investigate this process at academic discipline level. An online survey was developed to investigate teaching sustainability competences in 13 HEIs, from which 678 responses from educators were obtained. The competences and pedagogical approaches from the responses were ranked, and then the connections between the competences and pedagogical approaches per discipline were analysed using a correlations-based framework, from which three disciplines groups were created. The groups were categorised using diffusion of innovations theory, which indicated that some disciplines are more innovative than others in adopting sustainability competence-based teaching. The results are used to propose two frameworks to better understand the adoption of sustainability competence-based teaching: (a) the D-RAPID framework; and (b) the Disciplinary Multi-dimensional Sustainability Influence Change for Academia (D-MuSICA) memework. The adoption of sustainability competence-base education must expand from a single HEI perspective to a disciplinary collaborative one spanning many HEIs, where academic disciplines should learn from each other''s insights and mistakes and provide students with more transdisciplinary skillsets to make societies more sustainable. © 2021 The Authors. Sustainable Development published by ERP Environment and John Wiley & Sons Ltd

Prevalence and type distribution of human papillomavirus infection in women from North Sardinia, Italy

<p>Abstract</p> <p>Background</p> <p>Human papillomavirus (HPV) has been associated with several disorders of the genital tract, skin and oropharynx. The aims of our study were to evaluate the prevalence of HPV infection in women between 15 and 54 years of age in North Sardinia, Italy, to identify the prevalence of High Risk - Human papillomaviruses (HR-HPV) genotypes and to establish a correlation between molecular and cytological results.</p> <p>Methods</p> <p>From 2007 to 2009 we consecutively enrolled women aged 15-54 years admitted to public and private outpatient settings. All the participants filled in a questionnaire about the socio-cultural state, sexual activity and awareness about HPV. 323 cervical specimens were tested for HPV-DNA and HPV genotypes with INNO-LiPA HPV Genotyping CE Amp kit. Samples showing positivity to some HPV genotypes were re-tested using "in house" quantitative Real-Time PCR assays.</p> <p>Results</p> <p>Overall HPV-DNA positivity was detected in 35.9% of the women. The prevalence of HR-HPV infection among HPV positive samples was 93.1% with a specific prevalence of HPV 16, 51, 31, 53 and 18 of 54.3%, 37.9%, 10.3%, 6.9% and 5.2%, respectively. Co-infection with any HPV, HR-HPV, LR-HPV and HR/LR-HPV type was 18.3%, 14.9%, 0.9% and 2.5%, respectively; HPV 16/51 co-infection was detected in 64.6% of the HR-HPV co-infection group. The most frequent HPV-genotypes detected were 16 (32.5%) and 51 (22.7%). Among the 57 patients harboring mono-infection the most prevalent HPV genotypes were 16 (38.6%) and 31(10.5%). A multivariate analysis identified a statistical significant association between HPV infection and age and between HPV infection and previous sexual transmitted diseases. A statistically significant association between cytological cervical lesions and generic HPV exposure was identified.</p> <p>Conclusions</p> <p>To our knowledge, this is the first survey evaluating the prevalence of HPV infection in Northern Sardinia and drawing attention to the unusual high proportion of genotype HPV 51. Given the recent implementation of a widespread immunization program with vaccines not containing HPV 51, it has been relevant to prove the high prevalence of this HPV genotype from the start of the vaccination campaign, in order to avoid in the future attributing to the vaccination program a possible selection effect (HPV replacement).</p

Keeping vigil over the profession: a grounded theory of the context of nurse anaesthesia practice

<p>Abstract</p> <p>Background</p> <p>Nurse anaesthetists in the US have faced continued, repeated challenges to their profession. Regardless, they have met these challenges and have established themselves as major anaesthesia care providers. In this paper we address the research question: How do certified registered nurse anaesthetists (CRNAs) manage the socio-political context in which they provide care for their patients?</p> <p>Methods</p> <p>Grounded theory was used to explore how nurse anaesthetists protect and promote their profession. Purposive, snowball, and theoretical sampling was used and data were collected through participant observation and interviews conducted at a conference of the professional association, an educational program, by telephone, email exchanges, and time spent in operating rooms and an outpatient surgical clinic. Analysis included coding at increasingly abstract levels and constant comparison.</p> <p>Results</p> <p>The basic social process identified was Keeping Vigil Over the Profession, which explains how nurse anaesthetists protect and promote their profession. It is comprised of three contextual categories: Establishing Public Credibility through regulatory and educational standards, Political Vigilance and taking action in governmental and policy arenas, and Tending the Flock through a continuous information loop between local and administrative/political levels.</p> <p>Conclusions</p> <p>From our study of the context of nurse anaesthesia practice, it is clear that CRNAs are dedicated to protecting their ability to provide high quality patient care by maintaining constant vigilance over their profession.</p

Seroepidemiology of SARS-CoV-2 infections in an urban population-based cohort in León, Nicaragua

In a Nicaraguan population-based cohort, SARS-CoV-2 seroprevalence reached 28% in the first 6 months of the country's epidemic and reached 35% 6 months later. Immune waning was uncommon. Individuals with a seropositive household member were over three times as likely to be seropositive themselves, suggesting the importance of household transmission