Accreting Black Holes

This chapter provides a general overview of the theory and observations of black holes in the Universe and on their interpretation. We briefly review the black hole classes, accretion disk models, spectral state classification, the AGN classification, and the leading techniques for measuring black hole spins. We also introduce quasi-periodic oscillations, the shadow of black holes, and the observations and the theoretical models of jets.Comment: 41 pages, 18 figures. To appear in "Tutorial Guide to X-ray and Gamma-ray Astronomy: Data Reduction and Analysis" (Ed. C. Bambi, Springer Singapore, 2020). v3: fixed some typos and updated some parts. arXiv admin note: substantial text overlap with arXiv:1711.1025

A Functional Nuclear Localization Sequence in the C. elegans TRPV Channel OCR-2

The ability to modulate gene expression in response to sensory experience is critical to the normal development and function of the nervous system. Calcium is a key activator of the signal transduction cascades that mediate the process of translating a cellular stimulus into transcriptional changes. With the recent discovery that the mammalian Cav1.2 calcium channel can be cleaved, enter the nucleus and act as a transcription factor to control neuronal gene expression, a more direct role for the calcium channels themselves in regulating transcription has begun to be appreciated. Here we report the identification of a nuclear localization sequence (NLS) in the C. elegans transient receptor potential vanilloid (TRPV) cation channel OCR-2. TRPV channels have previously been implicated in transcriptional regulation of neuronal genes in the nematode, although the precise mechanism remains unclear. We show that the NLS in OCR-2 is functional, being able to direct nuclear accumulation of a synthetic cargo protein as well as the carboxy-terminal cytosolic tail of OCR-2 where it is endogenously found. Furthermore, we discovered that a carboxy-terminal portion of the full-length channel can localize to the nucleus of neuronal cells. These results suggest that the OCR-2 TRPV cation channel may have a direct nuclear function in neuronal cells that was not previously appreciated

Medical student changes in self-regulated learning during the transition to the clinical environment

BACKGROUND: Self-regulated learning (SRL), which is learners’ ability to proactively select and use different strategies to reach learning goals, is associated with academic and clinical success and life-long learning. SRL does not develop automatically in the clinical environment and its development during the preclinical to clinical learning transition has not been quantitatively studied. Our study aims to fill this gap by measuring SRL in medical students during the transitional period and examining its contributing factors. METHODS: Medical students were invited to complete a questionnaire at the commencement of their first clinical year (T0), and 10 weeks later (T1). The questionnaire included the Motivated Strategies for Learning Questionnaire (MSLQ) and asked about previous clinical experience. Information about the student’s background, demographic characteristics and first clinical rotation were also gathered. RESULTS: Of 118 students invited to participate, complete paired responses were obtained from 72 medical students (response rate 61%). At T1, extrinsic goal orientation increased and was associated with gender (males were more likely to increase extrinsic goal orientation) and type of first attachment (critical care and community based attachments, compared to hospital ward based attachments). Metacognitive self-regulation decreased at T1 and was negatively associated with previous clinical experience. CONCLUSIONS: Measurable changes in self-regulated learning occur during the transition from preclinical learning to clinical immersion, particularly in the domains of extrinsic goal orientation and metacognitive self–regulation. Self–determination theory offers possible explanations for this finding which have practical implications and point the way to future research. In addition, interventions to promote metacognition before the clinical immersion may assist in preserving SRL during the transition and thus promote life-long learning skills in preparation for real-world practice. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12909-017-0902-7) contains supplementary material, which is available to authorized users

Investigating the association between health literacy and non-adherence

Background Low health literacy is expected to be associated with medication non-adherence and early research indicated that this might be the case. Further research suggested that the relationship may be more equivocal. Aim of the review The goal of this paper is initially to clarify whether there is a clear relationship between health literacy and non-adherence. Additionally, this review aims to identify factors that may influence that relationship and ultimately to better understand the mechanisms that may be at work in the relationship. Method English language original research or published reviews of health literacy and non-adherence to orally administered medications in adults were identified through a search of four bibliographic databases (PubMed, EMBASE, CINAHL, and EBSCO Health). Results The search protocol produced 78 potentially relevant articles, of which 16 articles addressed factors that contribute to non-adherence and 24 articles reported on the results of research into the relationship between non-adherence and health literacy. Factors that contribute to non-adherence can be categorised into patient related factors, including patient beliefs; medication related factors; logistical factors; and factors around the patient-provider relationship. Of the 23 original research articles that investigated the relationship between non-adherence and health literacy, only five reported finding clear evidence of a relationship, four reported mixed results and 15 articles reported not finding the expected relationship. Research on possible mechanisms relating health literacy to non-adherence suggest that disease and medication knowledge are not sufficient for addressing non-adherence while self-efficacy is an important factor. Other findings suggest a possible U-shaped relationship between non-adherence and health literacy where people with low health literacy are more often non-adherent, largely unintentionally; people with moderate health literacy are most adherent; and people with high health literacy are somewhat non-adherent, sometimes due to intentional non-adherence. Conclusion It is clear that relevant research generally fails to find a significant relationship between non-adherence and health literacy. A U-shaped relationship between these two conditions would explain why linear statistical tests fail to identify a relationship across all three levels of health literacy. It can also account for the conditions under which both positive and negative relationships may be found