3,934 research outputs found
Positive, warm T cell crossmatch in cardiac transplantation: With transient vasculitis and without hyperacute rejection
Canonical Generations and the British Left: The Narrative Construction of the Miners’ Strike 1984–85
‘Generations’ have been invoked to describe a variety of social and cultural relationships, and to understand the development of self-conscious group identity. Equally, the term can be an applied label and politically useful construct; generations can be retrospectively produced. Drawing on the concept of ‘canonical generations’ – those whose experiences come to epitomise an event of historic and symbolic importance – this article examines the narrative creation and functions of ‘generations’ as collective memory shapes and re-shapes the desire for social change. Building a case study of the canonical role of the miners’ strike of 1984–85 in the narrative history of the British left, it examines the selective appropriation and transmission of the past in the development of political consciousness. It foregrounds the autobiographical narratives of activists who, in examining and legitimising their own actions and prospects, (re)produce a ‘generation’ in order to create a relatable and useful historical understanding
T cell lineage choice and differentiation in the absence of the RNase III enzyme dicer
The ribonuclease III enzyme Dicer is essential for the processing of micro-RNAs (miRNAs) and small interfering RNAs (siRNAs) from double-stranded RNA precursors. miRNAs and siRNAs regulate chromatin structure, gene transcription, mRNA stability, and translation in a wide range of organisms. To provide a model system to explore the role of Dicer-generated RNAs in the differentiation of mammalian cells in vivo, we have generated a conditional Dicer allele. Deletion of Dicer at an early stage of T cell development compromised the survival of alphabeta lineage cells, whereas the numbers of gammadelta-expressing thymocytes were not affected. In developing thymocytes, Dicer was not required for the maintenance of transcriptional silencing at pericentromeric satellite sequences (constitutive heterochromatin), the maintenance of DNA methylation and X chromosome inactivation in female cells (facultative heterochromatin), and the stable shutdown of a developmentally regulated gene (developmentally regulated gene silencing). Most remarkably, given that one third of mammalian mRNAs are putative miRNA targets, Dicer seems to be dispensable for CD4/8 lineage commitment, a process in which epigenetic regulation of lineage choice has been well documented. Thus, although Dicer seems to be critical for the development of the early embryo, it may have limited impact on the implementation of some lineage-specific gene expression programs
Dynamics of the power-duration relationship during prolonged endurance exercise and influence of carbohydrate ingestion
This is the author accepted manuscript. The final version is available from the American Physiological Society via the DOI in this recordWe tested the hypotheses that the parameters of the power-duration relationship, estimated as the end-test power (EP) and work done above EP (WEP) during a 3-min all out exercise test (3MT), would be reduced progressively following 40 min, 80 min and 2 h of heavy-intensity cycling, and that carbohydrate (CHO) ingestion would attenuate the reduction in EP and WEP. Sixteen participants completed a 3MT without prior exercise (control), immediately after 40 min, 80 min and 2-h of heavy-intensity exercise while consuming a placebo beverage, and also after 2-h of heavy-intensity exercise while consuming a CHO supplement (60 g/h CHO). There was no difference in EP measured without prior exercise (260 ± 37 W) compared to EP following 40 min (268 ± 39 W) or 80 min (260 ± 40 W) of heavy-intensity exercise; however, after 2-h, EP was 9% lower compared to control (236 ± 47 W; P<0.05). There was no difference in WEP measured without prior exercise (17.9 ± 3.3 kJ) compared to after 40 min of heavy-intensity exercise (16.1 ± 3.3 kJ), but WEP was lower (P<0.05) than control after 80 min (14.7 ± 2.9 kJ) and 2-h (13.8 ± 2.7 kJ). Compared to placebo, CHO ingestion negated the reduction of EP following 2-h of heavy-intensity exercise (254 ± 49 W) but had no effect on WEP (13.5 ± 3.4 kJ). These results reveal a different time course for the deterioration of EP and WEP during prolonged endurance exercise and indicate that EP is sensitive to CHO availability
Incidental findings found in "healthy" volunteers during imaging performed for research: current legal and ethical implications
Incidental findings found in “healthy” volunteers during research imaging are common and have important implications for study design and performance, particularly in the areas of informed consent, subjects' rights, clinical image analysis and disclosure. In this study, we aimed to determine current practice and regulations concerning information that should be given to research subjects when obtaining consent, reporting of research images, who should be informed about any incidental findings and the method of disclosure. We reviewed all UK, European and international humanitarian, legal and ethical agencies' guidance. We found that the guidance on what constitutes incidental pathology, how to recognise it and what to do about it is inconsistent between agencies, difficult to find and less complete in the UK than elsewhere. Where given, guidance states that volunteers should be informed during the consent process about how research images will be managed, whether a mechanism exists for identifying incidental findings, arrangements for their disclosure, the potential benefit or harm and therapeutic options. The effects of incidentally discovered pathology on the individual can be complex and far-reaching. Radiologist involvement in analysis of research images varies widely; many incidental findings might therefore go unrecognised. In conclusion, guidance on the management of research imaging is inconsistent, limited and does not address the interests of volunteers. Improved standards to guide management of research images and incidental findings are urgently required
Popliteal lymph node dissection for metastatic squamous cell carcinoma: a case report of an uncommon procedure for an uncommon presentation
Lymph node metastasis from cutaneous squamous cell carcinoma is uncommon. The popliteal fossa is rarely involved with metastasis. Popliteal lymph node dissection is uncommonly performed and not frequently discussed in the literature. We present a case of squamous cell carcinoma of the heel with popliteal and inguinal metastasis. This is followed by a description of the relevant anatomy of the popliteal fossa and the technique of popliteal lymphadenectomy
Identification and validation of oncologic miRNA biomarkers for Luminal A-like breast cancer
Introduction: Breast cancer is a common disease with distinct tumor subtypes phenotypically characterized by ER and HER2/neu receptor status. MiRNAs play regulatory roles in tumor initiation and progression, and altered miRNA expression has been demonstrated in a variety of cancer states presenting the potential for exploitation as cancer biomarkers. Blood provides an excellent medium for biomarker discovery. This study investigated systemic miRNAs differentially expressed in Luminal A-like (ER+PR+HER2/neu-) breast cancer and their effectiveness as oncologic biomarkers in the clinical setting. Methods: Blood samples were prospectively collected from patients with Luminal A-like breast cancer (n=54) and controls (n=56). RNA was extracted, reverse transcribed and subjected to microarray analysis (n=10 Luminal A-like; n=10 Control). Differentially expressed miRNAs were identified by artificial neural network (ANN) data-mining algorithms. Expression of specific miRNAs was validated by RQ-PCR (n=44 Luminal A; n=46 Control) and potential relationships between circulating miRNA levels and clinicopathological features of breast cancer were investigated. Results: Microarray analysis identified 76 differentially expressed miRNAs. ANN revealed 10 miRNAs for further analysis ( miR-19b, miR-29a, miR-93, miR-181a, miR-182, miR-223, miR-301a, miR-423-5p, miR-486-5 and miR-652 ). The biomarker potential of 4 miRNAs ( miR-29a, miR-181a , miR-223 and miR-652 ) was confirmed by RQ-PCR, with significantly reduced expression in blood of women with Luminal A-like breast tumors compared to healthy controls (p=0.001, 0.004, 0.009 and 0.004 respectively). Binary logistic regression confirmed that combination of 3 of these miRNAs ( miR-29a, miR-181a and miR-652 ) could reliably differentiate between cancers and controls with an AUC of 0.80. Conclusion: This study provides insight into the underlying molecular portrait of Luminal A-like breast cancer subtype. From an initial 76 miRNAs, 4 were validated with altered expression in the blood of women with Luminal A-like breast cancer. The expression profiles of these 3 miRNAs, in combination with mammography, has potential to facilitate accurate subtype- specific breast tumor detection
Radioactive 26Al and massive stars in the Galaxy
Gamma-rays from radioactive 26Al (half life ~7.2 10^5 yr) provide a
'snapshot' view of ongoing nucleosynthesis in the Galaxy. The Galaxy is
relatively transparent to such gamma-rays, and emission has been found
concentrated along the plane of the Galaxy. This led to the conclusion1 that
massive stars throughout the Galaxy dominate the production of 26Al. On the
other hand, meteoritic data show locally-produced 26Al, perhaps from spallation
reactions in the protosolar disk. Furthermore, prominent gamma-ray emission
from the Cygnus region suggests that a substantial fraction of Galactic 26Al
could originate in localized star-forming regions. Here we report high spectral
resolution measurements of 26Al emission at 1808.65 keV, which demonstrate that
the 26Al source regions corotate with the Galaxy, supporting its Galaxy-wide
origin. We determine a present-day equilibrium mass of 2.8 (+/-0.8) M_sol of
26Al. We use this to estimate that the frequency of core collapse (i.e. type
Ib/c and type II) supernovae to be 1.9(+/- 1.1) events per century.Comment: accepted for publication in Nature, 24 pages including Online
Supplements, 11 figures, 1 tabl
Global-Vector Representation of the Angular Motion of Few-Particle Systems II
The angular motion of a few-body system is described with global vectors
which depend on the positions of the particles. The previous study using a
single global vector is extended to make it possible to describe both natural
and unnatural parity states. Numerical examples include three- and four-nucleon
systems interacting via nucleon-nucleon potentials of AV8 type and a 3
system with a nonlocal potential. The results using the
explicitly correlated Gaussian basis with the global vectors are shown to be in
good agreement with those of other methods. A unique role of the unnatural
parity component, caused by the tensor force, is clarified in the state
of He. Two-particle correlation function is calculated in the coordinate
and momentum spaces to show different characteristics of the interactions
employed.Comment: 39 pages, 4 figure
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