Reflection formulas for order derivatives of Bessel functions

From new integral representations of the $n$-th derivative of Bessel functions with respect to the order, we derive some reflection formulas for the first and second order derivative of $J_{\nu }\left( t\right)$ and % Y_{\nu }\left( t\right) for integral order, and for the $n$-th order derivative of $I_{\nu }\left( t\right)$ and $K_{\nu }\left( t\right)$ for arbitrary real order. As an application of the reflection formulas obtained for the first order derivative, we extend some formulas given in the literature to negative integral order. Also, as a by-product, we calculate an integral which does not seem to be reported in the literature.Comment: arXiv admin note: text overlap with arXiv:1808.0560

A note on some reduction formulas for the incomplete beta function and the Lerch transcedent

We derive new reduction formulas for the incomplete beta function and the Lerch transcendent in terms of elementary functions. As an application, we calculate some new integrals. Also, we use these reduction formulas to test the performance of the algorithms devoted to the numerical evaluation of the incomplete beta function

Maximum Temperature in Dry Surface Grinding for High Peclet Number and Arbitrary Heat Flux Profile

Regarding heat transfer in dry surface grinding, simple asymptotic expressions of the maximum temperature for large Peclet numbers are derived. For this purpose, we consider the most common heat flux profiles reported in the literature, such as constant, linear, triangular, and parabolic. In the constant case, we provide a refinement of the expression given in the literature. In the linear case, we derive the same expression found in the literature, being the latter fitted by using a linear regression. The expressions for the triangular and parabolic cases are novel

New young planetary nebulae in IPHAS

Original article can be found at: http://www.aanda.org/ Copyright The European Southern Observatory. DOI: 10.1051/0004-6361/200811575Aims. We search for very small-diameter galactic planetary nebulae (PNe) representing the earliest phases of PN evolution. The IPHAS catalogue of H-emitting stars provides a useful basis for this study since all sources present in this catalogue must be of small angular diameter. Methods. The PN candidates are selected based on their location in two colour-colour diagrams: IPHAS (r' - H) vs. (r' - i'), and 2MASS (J - H) vs. (H - ). Spectroscopic follow-up was carried out on a sample of candidates to confirm their nature. Results. We present a total of 83 PN candidates. We were able to obtain spectra or find the classification from the literature for 35 candidates. Five of these objects are likely to be new PNe, including one large bipolar PN discovered serendipitously close to an emission-line star. PN distances deduced from extinction-distance relations based on IPHAS field-star photometry are presented for the first time. These yield distance estimates for our objects in the range 2 kpc and 6 kpc. From the data in hand, we conclude that four of the discovered objects are probably young PNe.Peer reviewe

High Hepatitis B Prevalence and Vaccination Needs Among Transgender Women and Men Sex Workers in Barcelona, Spain

Background. Transgender women sex workers (TWSWs) and men sex workers (MSWs) are especially vulnerable to acquiring hepatitis B virus (HBV) infection. We aimed to describe HBV prevalence (hepatitis B surface antigen [HBsAg] and core antibody [HBcAb]) and associated risk factors for HBV exposure (HBcAb), to assess vaccination status and risk factors for no prior vaccination, and to compare HBV prevalence and vaccination status between TWSWs and MSWs. Methods. The SexCohort study was advertised to TWSWs and MSWs through several communication channels. At cohort entry through 2 community-based organizations in Barcelona, the study population was screened for HBV and other sexually transmitted infections, and an epidemiological questionnaire was administered (n = 271). Results. Overall, 93.0% of participants were migrants, mostly from South and Central American countries. HBsAg prevalence was 1.9% (TWSWs, 2.4%; vs MSWs, 0.9%; P = .42), and previous exposure to HBV was 31.8% (TWSWs, 38.5%; vs MSWs, 20.8%; P = .002). Over 5 years of sex work (adjusted odds ratio [aOR], 9.35), prior exposure to Treponema pallidum (aOR, 3.49), and treatment with anxiolytic drugs (aOR, 3.23) were associated with HBV exposure. Overall, 33.7% of participants exhibited immunity from vaccination (TWSWs, 30.8%; vs MSWs, 38.61%; P < .001), while 34.4% were candidates to HBV vaccination (TWSWs, 30.8%; vs MSWs, 40.6%; P < .001). Never having been on pre-exposure prophylaxis for HIV (odds ratio [OR], 4.23) and non-Spanish origin (OR, 5.00) were associated with no prior HBV vaccination. Conclusions. There is a need to reinforce screening and vaccination programs aimed at TWSWs and MSWs as integrated services offered at the community centers commonly accessed by these populations