362 research outputs found
Mononeuritis multiplex: an uncommon neurological manifestation of cytomegalovirus reactivation in an HIV-infected patient
BACKGROUND: Cytomegalovirus (CMV) reactivation with neurological involvement in patients with acquired immunodeficiency syndrome (AIDS) is increasingly rare since the introduction of antiretroviral therapy (ART). Manifestations include encephalitis, myelitis, polyradiculopathy and, less commonly, mononeuritis multiplex (MNM). We report a case of disseminated CMV disease with gastrointestinal and peripheral and central nervous system involvement in a patient with AIDS, manifesting primarily as MNM. CASE PRESENTATION: A 31-year old woman with AIDS presented with a clinical picture of MNM. Electromyography confirmed the clinical findings. CMV DNA was detected in cerebrospinal fluid (CSF) and blood. Gastrointestinal involvement was histologically documented. HIV RNA was also detected in CSF and brain MRI was consistent with HIV encephalopathy. A diagnosis of disseminated CMV disease (with esophagitis, colitis, encephalitis and MNM) and HIV encephalopathy was made. Treatment consisted of ganciclovir and foscarnet, followed by maintenance therapy with valganciclovir. Evolution was favorable and valganciclovir was stopped after sustained immune recovery following ART initiation. CONCLUSION: We discuss the diagnostic approach to CMV neurological disease, with a focus on MNM and CMV encephalitis. Combination therapy with ganciclovir and foscarnet should be considered for all forms of neurological involvement, although available data are scarce. Since there is significant overlap between CMV encephalitis and HIV encephalopathy, ART drugs with higher CSF penetration may have to be considered. ART and immune recovery are essential to improve outcomes
Testing reflection features in 4U 1705-44 with XMM-Newton, BeppoSAX and RXTE in the hard and soft state
We use data of the bright atoll source 4U 1705-44 taken with XMM-Newton,
BeppoSAX and RXTE both in the hard and in the soft state to perform a
self-consistent study of the reflection component in this source. Although the
data from these X-ray observatories are not simultaneous, the spectral
decomposition is shown to be consistent among the different observations, when
the source flux is similar. We therefore select observations performed at
similar flux levels in the hard and soft state in order to study the spectral
shape in these two states in a broad band (0.1-200 keV) energy range, with good
energy resolution, and using self-consistent reflection models. These
reflection models provide a good fit for the X-ray spectrum both in the hard
and in the soft state in the whole spectral range. We discuss the differences
in the main spectral parameters we find in the hard and the soft state,
respectively, providing evidence that the inner radius of the optically thick
disk slightly recedes in the hard state.Comment: Accepted for publication in A&A, 20 pages, 12 figure
In search of critical thinking in psychology: an exploration of student and lecturer understandings in higher education
This qualitative study of understandings of critical thinking in higher education aimed to identify themes that could help to demystify critical thinking and inform its more explicit incorporation in the psychology curriculum. Data collected from focus groups with 26 undergraduate psychology students and individual semi-structured interviews with 4 psychology lecturers were examined using thematic analysis. The same key themes were identified from both student and lecturer data: ‘vague beginnings’, ‘conceptualizations’, ‘development and transitions’, and ‘learning strategies’. Both students and lecturers described critical thinking as implicit knowledge that develops through social interactions. The findings indicate the importance of explicit discussion about critical thinking, and could be used to inform the design and delivery of instructional methods to promote critical thinkin
Desempenho da solicitação do perfil lipÃdico entre os setores público e privado
OBJECTIVE: To evaluate the performance of lipid profile screening according to the mode of financing of medical appointments - public or private. METHODS: A population-based cross-sectional study was carried out with a multi-stage sampling strategy. The study included 3,136 adults (>; 20 years old) from the city of Pelotas, Southern Brazil, in 2006. The following indicators were calculated: coverage (proportion of screened individuals among those meeting screening criteria), focus (proportion of individuals meeting screening criteria among those who were tested), screening errors (tests in individuals not meeting screening criteria - overscreening - and no screening of individuals meeting the screening criteria - underscreening), and screening ratio (ratio between number of individuals who met screening criteria and the number who failed to meet screening criteria among all individuals tested). Bivariate analyses were performed using Chi-squared tests. 95% confidence intervals (95% CI) were calculated for all parameters assessed. RESULTS: General coverage was 73.0% (95%CI: 70.8;75.2), and focus was 67.2% (95% CI: 64.7;69.3). In the public sector, compared to the private/health plan sector, coverage was lower (65.2% vs. 82.2%; pOBJETIVO: Avaliar o desempenho do rastreio do perfil lipÃdico conforme o financiamento da consulta médica - setores público e privado. MÉTODOS: Estudo transversal de base populacional com amostragem em múltiplos estágios, incluindo 3.136 adultos (>; 20 anos) de Pelotas, Brasil, 2006. Foram calculados: cobertura (proporção de indivÃduos rastreados entre aqueles com indicação de rastreio), foco (proporção de indivÃduos com indicação entre os rastreados), erros de rastreio (sobre-rastreio: exames em indivÃduos sem indicação, e sub-rastreio: não solicitação entre indivÃduos com risco) e razão de rastreio (razão entre número de rastreados que atendiam aos critérios e número dos que não atendiam). Análises bivariadas foram realizadas por meio do teste qui-quadrado e intervalos de confiança de 95% foram estimados para os parâmetros avaliados. RESULTADOS: A cobertura geral foi 73,0% (IC 95%: 70,8;75,2) e o foco 67,2% (IC 95%: 64,7;69,3). O setor público teve, em relação ao privado/convênio, menor cobertura (65,2% versus 82,2%;
A complex of BRCA2 and PP2A-B56 is required for DNA repair by homologous recombination
Mutations in the tumour suppressor gene BRCA2 are associated with predisposition to breast and ovarian cancers. BRCA2 has a central role in maintaining genome integrity by facilitating the repair of toxic DNA double-strand breaks (DSBs) by homologous recombination (HR). BRCA2 acts by controlling RAD51 nucleoprotein filament formation on resected single-stranded DNA, but how BRCA2 activity is regulated during HR is not fully understood. Here, we delineate a pathway where ATM and ATR kinases phosphorylate a highly conserved region in BRCA2 in response to DSBs. These phosphorylations stimulate the binding of the protein phosphatase PP2A-B56 to BRCA2 through a conserved binding motif. We show that the phosphorylation-dependent formation of the BRCA2-PP2A-B56 complex is required for efficient RAD51 filament formation at sites of DNA damage and HR-mediated DNA repair. Moreover, we find that several cancer-associated mutations in BRCA2 deregulate the BRCA2-PP2A-B56 interaction and sensitize cells to PARP inhibition. Collectively, our work uncovers PP2A-B56 as a positive regulator of BRCA2 function in HR with clinical implications for BRCA2 and PP2A-B56 mutated cancers
Measuring Black Hole Spin using X-ray Reflection Spectroscopy
I review the current status of X-ray reflection (a.k.a. broad iron line)
based black hole spin measurements. This is a powerful technique that allows us
to measure robust black hole spins across the mass range, from the stellar-mass
black holes in X-ray binaries to the supermassive black holes in active
galactic nuclei. After describing the basic assumptions of this approach, I lay
out the detailed methodology focusing on "best practices" that have been found
necessary to obtain robust results. Reflecting my own biases, this review is
slanted towards a discussion of supermassive black hole (SMBH) spin in active
galactic nuclei (AGN). Pulling together all of the available XMM-Newton and
Suzaku results from the literature that satisfy objective quality control
criteria, it is clear that a large fraction of SMBHs are rapidly-spinning,
although there are tentative hints of a more slowly spinning population at high
(M>5*10^7Msun) and low (M<2*10^6Msun) mass. I also engage in a brief review of
the spins of stellar-mass black holes in X-ray binaries. In general,
reflection-based and continuum-fitting based spin measures are in agreement,
although there remain two objects (GROJ1655-40 and 4U1543-475) for which that
is not true. I end this review by discussing the exciting frontier of
relativistic reverberation, particularly the discovery of broad iron line
reverberation in XMM-Newton data for the Seyfert galaxies NGC4151, NGC7314 and
MCG-5-23-16. As well as confirming the basic paradigm of relativistic disk
reflection, this detection of reverberation demonstrates that future large-area
X-ray observatories such as LOFT will make tremendous progress in studies of
strong gravity using relativistic reverberation in AGN.Comment: 19 pages. To appear in proceedings of the ISSI-Bern workshop on "The
Physics of Accretion onto Black Holes" (8-12 Oct 2012). Revised version adds
a missing source to Table 1 and Fig.6 (IRAS13224-3809) and corrects the
referencing of the discovery of soft lags in 1H0707-495 (which were in fact
first reported in Fabian et al. 2009
A Systematic Two-Layer Approach to Develop Web-based Experimentation Environments for Control Engineering Education
This paper introduces the systematic approach currently used by the Department of Computer Science and Automatic Control of the Spanish University of Distance Learning (UNED) to develop Web-based laboratories for distance learning of topics with high technical contents such as control engineering. This approach differentiates two layers in the construction of web- based laboratories: the experimentation layer and the e-learning layer. For the experimentation layer, LabVIEW and data acquisition boards from National Instruments are used to create the server-side applications and Easy Java Simulations for the client-side interfaces. For the e-learning layer, the eMersion environment is used to support the required flexible educational scheme. This paper describes the programming techniques implemented and the design considerations that justify these particular choices. As an llustrative case-study, an example of development of a web-based application is discussed, in which an electrical drive servo-motor is introduced as a convenient setup to practice with motion control applications. Other significant examples of web-based experiments developed by the authors are also reported
Efeito da adição de sulfato de amônio sobre a produção de ácido succÃnico durante a fermentação alcoólica
Succinic acid production by yeasts during alcoholic fermentation of cane molasse supplemented with 25, 50 and 100 ppm of nitrogen in the form of ammonium sulfate was determined by gas-liquid chromatography. Ethanol production was not effected by the different levels of nitrogen, but there was a significant reduction in the content of succinic acid which was inversely related with the ammonium sulfate concentration in the medium.A produção de ácido succÃnico por leveduras durante a fermentação alcoólica de mosto de melaço suplementado com 25, 50 e 100 ppm de nitrogênio na forma de sulfato de amônio foi determinada por cromatografia em fase gasosa. A adição de nitrogênio amoniacal não afetou significativamente a produção de álcool etÃlico. Houve redução significativa no teor de ácido succÃnico com o aumento da quantidade de nitrogênio adicionada
The MAGIC trial: a pragmatic, multicentre, parallel, noninferiority, randomised trial of melatonin versus midazolam in the premedication of anxious children attending for elective surgery under general anaesthesia
\ua9 2023 The Author(s)Background: Child anxiety before general anaesthesia and surgery is common. Midazolam is a commonly used premedication to address this. Melatonin is an alternative anxiolytic, however trials evaluating its efficacy in children have delivered conflicting results. Methods: This multicentre, double-blind randomised trial was performed in 20 UK NHS Trusts. A sample size of 624 was required to declare noninferiority of melatonin. Anxious children, awaiting day case elective surgery under general anaesthesia, were randomly assigned 1:1 to midazolam or melatonin premedication (0.5 mg kg−1, maximum 20 mg) 30 min before transfer to the operating room. The primary outcome was the modified Yale Preoperative Anxiety Scale-Short Form (mYPAS-SF). Secondary outcomes included safety. Results are presented as n (%) and adjusted mean differences with 95% confidence intervals. Results: The trial was stopped prematurely (n=110; 55 per group) because of recruitment futility. Participants had a median age of 7 (6–10) yr, and 57 (52%) were female. Intention-to-treat and per-protocol modified Yale Preoperative Anxiety Scale-Short Form analyses showed adjusted mean differences of 13.1 (3.7–22.4) and 12.9 (3.1–22.6), respectively, in favour of midazolam. The upper 95% confidence interval limits exceeded the predefined margin of 4.3 in both cases, whereas the lower 95% confidence interval excluded zero, indicating that melatonin was inferior to midazolam, with a difference considered to be clinically relevant. No serious adverse events were seen in either arm. Conclusion: Melatonin was less effective than midazolam at reducing preoperative anxiety in children, although the early termination of the trial increases the likelihood of bias. Clinical trial registration: ISRCTN registry: ISRCTN18296119
An inhomogeneous lepto-hadronic model for the radiation of relativistic jets. Application to XTE J1118+480
Conceptually reconstructing the physical conditions in relativistic jets,
given the observed electromagnetic spectrum, poses a complex inverse problem.
We aim to obtain a better understanding of the mechanisms operating in
relativistic jets through the modeling of their broadband electromagnetic
spectrum. We develop an inhomogeneous jet model where the injection of
relativistic primary and secondary particles takes place in a spatially
extended region. We calculate the contribution of all particles species to the
jet emissivity due to several processes, and assess the effect of gamma-ray
absorption in internal and external photon fields. A number of specific models
with different parameters are computed to explore the possibilities of this
scenario. We obtain a variety of spectral shapes depending on the model
parameters, some of them predicting significant gamma-ray emission. The
observed broadband spectrum of the low-mass microquasar XTE J1118+480 can be
satisfactorily reproduced by the model. Our results indicate that outbursts
similar to those displayed in the past by XTE J1118+480 might be detected with
present-day gamma-ray instruments.Comment: 12 pages, 9 figures, accepted for publication in Astronomy &
Astrophysics. Language edition and updated reference
- …