Star Formation and Dynamics in the Galactic Centre

The centre of our Galaxy is one of the most studied and yet enigmatic places in the Universe. At a distance of about 8 kpc from our Sun, the Galactic centre (GC) is the ideal environment to study the extreme processes that take place in the vicinity of a supermassive black hole (SMBH). Despite the hostile environment, several tens of early-type stars populate the central parsec of our Galaxy. A fraction of them lie in a thin ring with mild eccentricity and inner radius ~0.04 pc, while the S-stars, i.e. the ~30 stars closest to the SMBH (<0.04 pc), have randomly oriented and highly eccentric orbits. The formation of such early-type stars has been a puzzle for a long time: molecular clouds should be tidally disrupted by the SMBH before they can fragment into stars. We review the main scenarios proposed to explain the formation and the dynamical evolution of the early-type stars in the GC. In particular, we discuss the most popular in situ scenarios (accretion disc fragmentation and molecular cloud disruption) and migration scenarios (star cluster inspiral and Hills mechanism). We focus on the most pressing challenges that must be faced to shed light on the process of star formation in the vicinity of a SMBH.Comment: 68 pages, 35 figures; invited review chapter, to be published in expanded form in Haardt, F., Gorini, V., Moschella, U. and Treves, A., 'Astrophysical Black Holes'. Lecture Notes in Physics. Springer 201

D* Production in Deep Inelastic Scattering at HERA

This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel $D^{*+}\to (D^0 \to K^- \pi^+) \pi^+$ (+ c.c.) has been used in the study. The $e^+p$ cross section for inclusive D^{*\pm} production with $5<Q^2<100 GeV^2$ and $y<0.7$ is 5.3 \pms 1.0 \pms 0.8 nb in the kinematic region {$1.3<p_T(D^{*\pm})<9.0$ GeV and $| \eta(D^{*\pm}) |<1.5$}. Differential cross sections as functions of p_T(D^{*\pm}), $\eta(D^{*\pm}), W$ and $Q^2$ are compared with next-to-leading order QCD calculations based on the photon-gluon fusion production mechanism. After an extrapolation of the cross section to the full kinematic region in p_T(D^{*\pm}) and $\eta$(D^{*\pm}), the charm contribution $F_2^{c\bar{c}}(x,Q^2)$ to the proton structure function is determined for Bjorken $x$ between 2 $\cdot$ 10$^{-4}$ and 5 $\cdot$ 10$^{-3}$.Comment: 17 pages including 4 figure

Observation of Scaling Violations in Scaled Momentum Distributions at HERA

Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of $x$ and $Q^2$ using the ZEUS detector. The evolution of the scaled momentum, $x_p$, with $Q^2,$ in the range 10 to 1280 $GeV^2$, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of $Q^2$.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

Observation of Events with an Energetic Forward Neutron in Deep Inelastic Scattering at HERA

In deep inelastic neutral current scattering of positrons and protons at the center of mass energy of 300 GeV, we observe, with the ZEUS detector, events with a high energy neutron produced at very small scattering angles with respect to the proton direction. The events constitute a fixed fraction of the deep inelastic, neutral current event sample independent of Bjorken x and Q2 in the range 3 · 10-4 \u3c xBJ \u3c 6 · 10-3 and 10 \u3c Q2 \u3c 100 GeV2

Interactions of Tissue-Resident T Cells

Resident memory T cells (TRM) are non-circulating cells that play a critical role in protection from local infections and cancers. Flow cytometric and transcriptional analyses of these cells have defined their distinct phenotypes; imaging allows study of their morphology, localization, and interactions within tissues. Here, we describe commonly used methods to generate cutaneous CD8+ TRM and to prepare skin samples for analysis, including staining of cryostat sections, epidermal sheets, and tissue whole mounts. © 2023, The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.This work was supported by NIH grant 1R01AI163517 (to S.K. B.) and National Eczema Association Catalyst Research Grant NEA19-CRG121 (to R.M-B). Drawings were created with Biorender.comNEA19-CRG121; National Institutes of Health, NIH: 1R01AI16351

Results of shared learning of a new magnetic seed localisation device – A UK iBRA-NET breast cancer localisation study

Introduction Shared learning is imperative in the assessment and safe implementation of new healthcare interventions. Magnetic seeds (Magseed®) potentially offer logistical benefit over wire localisation for non-palpable breast lesions but few data exist on outcomes comparing these techniques. A national registration study (iBRA-NET) was conducted to collate device outcomes. In order to share learning, thematic analysis was conducted to ascertain early clinical experiences of Magseed® and wire guided localisation and explore how learning events may be applied to improve clinical outcomes. Methods A qualitative study of 27 oncoplastic surgeons, radiologists and physicians was conducted in January 2020 to ascertain the feasibility and challenges associated with Magseed® versus wire breast localisation surgery. Four focus groups were asked to discuss experiences, concerns and shared learning outcomes which were tabulated and analysed thematically. Results Three key themes were identified comparing Magseed® and wire localisation of breast lesions relating to preoperative, intraoperative and postoperative learning outcomes. Percutaneous Magseed® detection, instrument interference and potential seed or wire dislodgement were the most common issues identified. Clinician experience suggested Magseed® index lesion identification was non-inferior to wire placement and improved the patient pathway in terms of scheduling and multi-site insertion. Conclusions Prospective shared learning suggested Magseed® offered additional non-clinical benefits over wire localisation, improving the efficiency of the patient pathway. Recommendations for improving breast localisation technique, appropriate patient selection and clinical practice through shared learning are discussed that may aid other surgeons in the adoption of this relatively new technique

Crinoids from the Silurian of Western Estonia

The Silurian crinoids of Estonia are re-evaluated based on new collections and museum holdings. Nineteen species-level crinoid taxa are now recognized. All crinoid names applied to Estonian Silurian crinoids during the middle 19th century are disregarded. Especially significant is the fauna reported herein from the Pridoli because coeval crinoids are very poorly known from the Baltic region and elsewhere. One new genus and four new species are described from Estonia, namely Calceocrinus balticensis sp. nov., Desmidocrinus laevigatus sp. nov., Eucalyptocrinites tumidus sp. nov., and Saaremaacrinus estoniensis gen. et sp. nov