440 research outputs found
Free Convection about a Vertical Wavy Surface with Prescribed Surface Heat Flux in a Micropolar Fluid
 
Caste and identity processes among British Sikhs in the Midlands
This article examines the role of caste in the lives and identities of a small sample of young Sikhs in the English Midlands, using social psychological theory. In many academic writings, there is an implicit representation of caste as a negative aspect of South Asian culture and religion, and of caste identification as a means of oppressing vulnerable outgroups. Twenty-three young Sikhs were interviewed, and the qualitative data were analysed using Identity Process Theory. The following themes are discussed: (i) Caste as a Dormant Social Category, (ii) Anchoring the Caste Ingroup to Positive Social Representations, and (iii) Caste as an Inherent or Constructed Aspect of Identity? It is argued that neither caste nor caste-based prejudice appear to be prominent in the lives and identities of our interviewees but that, because caste is an important symbolic aspect of identity which can acquire salient in particular contexts, some Sikhs may wish to maintain this identity though endogamy. What is understood as caste-based prejudice can be better understood in terms of the downward comparison principle in social psychology. The implications for caste legislation are discussed
Compressed Sensing with off-axis frequency-shifting holography
This work reveals an experimental microscopy acquisition scheme successfully
combining Compressed Sensing (CS) and digital holography in off-axis and
frequency-shifting conditions. CS is a recent data acquisition theory involving
signal reconstruction from randomly undersampled measurements, exploiting the
fact that most images present some compact structure and redundancy. We propose
a genuine CS-based imaging scheme for sparse gradient images, acquiring a
diffraction map of the optical field with holographic microscopy and recovering
the signal from as little as 7% of random measurements. We report experimental
results demonstrating how CS can lead to an elegant and effective way to
reconstruct images, opening the door for new microscopy applications.Comment: vol 35, pp 871-87
Sparsity and Incoherence in Compressive Sampling
We consider the problem of reconstructing a sparse signal from a
limited number of linear measurements. Given randomly selected samples of
, where is an orthonormal matrix, we show that minimization
recovers exactly when the number of measurements exceeds where is the number of
nonzero components in , and is the largest entry in properly
normalized: . The smaller ,
the fewer samples needed.
The result holds for ``most'' sparse signals supported on a fixed (but
arbitrary) set . Given , if the sign of for each nonzero entry on
and the observed values of are drawn at random, the signal is
recovered with overwhelming probability. Moreover, there is a sense in which
this is nearly optimal since any method succeeding with the same probability
would require just about this many samples
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A double masked randomised 4-week, placebo-controlled study in the USA, Thailand and Taiwan to compare the efficacy of oral valganciclovir and topical 2% ganciclovir in the treatment of cytomegalovirus anterior uveitis: study protocol.
IntroductionCytomegalovirus (CMV) anterior uveitis is a recognised cause of anterior uveitis in immunocompetent patients and is preventable cause of vision loss. Ocular sequelae include corneal endothelial damage which can cause corneal oedema and failure, as well as glaucoma. Recurrences of inflammation are common and therefore patients are often exposed to long-term therapy. Oral therapy is available in the form of valganciclovir, although with the caveat of systemic side effects such as bone marrow suppression and renal failure necessitating regular interval laboratory monitoring. Recent reports have demonstrated that topical 2% ganciclovir solution may offer promising treatment outcomes in patients with CMV anterior uveitis with superior safety, cost-effectiveness and convenience profiles. An investigation into the relative equipoise of these therapies is warranted for these reasons.Methods and analysisThe Systemic and Topical Control of Cytomegalovirus Anterior uveitis: Treatment Outcomes (STACCATO) trial is designed as a multicentre, block randomised by site, double-masked, placebo-controlled trial comparing the efficacy of oral valganciclovir, 2% topical ganciclovir and placebo in treating PCR-proven CMV anterior uveitis. Participant clinical evaluation will occur at three study time points by a masked study ophthalmologist over a 28-day period to assess resolution of ocular inflammation (secondary outcome). A control group will provide additional information about the possible impact that the infected host's immune response may play in controlling local viral replication. The primary analysis is an analysis of covariance (three arms) correcting for baseline to compare quantitative CMV viral load in the anterior chamber (AC) aqueous fluid before and 7 days after treatment.Ethics and disseminationThe University of California San Francisco Committee on Human Research and the Khon Kaen University Institutional Review Board have given ethical approval. The results of this trial will be presented at local and international meetings and submitted for peer-reviewed journals for publication.Trial registration numberNCT03576898
Impact of the SPOP Mutant Subtype on the Interpretation of Clinical Parameters in Prostate Cancer.
Purpose: Molecular characterization of prostate cancer, including The Cancer Genome Atlas, has revealed distinct subtypes with underlying genomic alterations. One of these core subtypes, SPOP (speckle-type POZ protein) mutant prostate cancer, has previously only been identifiable via DNA sequencing, which has made the impact on prognosis and routinely used risk stratification parameters unclear.
Methods: We have developed a novel gene expression signature, classifier (Subclass Predictor Based on Transcriptional Data), and decision tree to predict the SPOP mutant subclass from RNA gene expression data and classify common prostate cancer molecular subtypes. We then validated and further interrogated the association of prostate cancer molecular subtypes with pathologic and clinical outcomes in retrospective and prospective cohorts of 8,158 patients.
Results: The subclass predictor based on transcriptional data model showed high sensitivity and specificity in multiple cohorts across both RNA sequencing and microarray gene expression platforms. We predicted approximately 8% to 9% of cases to be SPOP mutant from both retrospective and prospective cohorts. We found that the SPOP mutant subclass was associated with lower frequency of positive margins, extraprostatic extension, and seminal vesicle invasion at prostatectomy; however, SPOP mutant cancers were associated with higher pretreatment serum prostate-specific antigen (PSA). The association between SPOP mutant status and higher PSA level was validated in three independent cohorts. Despite high pretreatment PSA, the SPOP mutant subtype was associated with a favorable prognosis with improved metastasis-free survival, particularly in patients with high-risk preoperative PSA levels.
Conclusion: Using a novel gene expression model and a decision tree algorithm to define prostate cancer molecular subclasses, we found that the SPOP mutant subclass is associated with higher preoperative PSA, less adverse pathologic features, and favorable prognosis. These findings suggest a paradigm in which the interpretation of common risk stratification parameters, particularly PSA, may be influenced by the underlying molecular subtype of prostate cancer
Development and Validation of a 28-gene Hypoxia-related Prognostic Signature for Localized Prostate Cancer.
BACKGROUND: Hypoxia is associated with a poor prognosis in prostate cancer. This work aimed to derive and validate a hypoxia-related mRNA signature for localized prostate cancer.
METHOD: Hypoxia genes were identified in vitro via RNA-sequencing and combined with in vivo gene co-expression analysis to generate a signature. The signature was independently validated in eleven prostate cancer cohorts and a bladder cancer phase III randomized trial of radiotherapy alone or with carbogen and nicotinamide (CON).
RESULTS: A 28-gene signature was derived. Patients with high signature scores had poorer biochemical recurrence free survivals in six of eight independent cohorts of prostatectomy-treated patients (Log rank test P \u3c .05), with borderline significances achieved in the other two (P \u3c .1). The signature also predicted biochemical recurrence in patients receiving post-prostatectomy radiotherapy (n = 130, P = .007) or definitive radiotherapy alone (n = 248, P = .035). Lastly, the signature predicted metastasis events in a pooled cohort (n = 631, P = .002). Prognostic significance remained after adjusting for clinic-pathological factors and commercially available prognostic signatures. The signature predicted benefit from hypoxia-modifying therapy in bladder cancer patients (intervention-by-signature interaction test P = .0026), where carbogen and nicotinamide was associated with improved survival only in hypoxic tumours.
CONCLUSION: A 28-gene hypoxia signature has strong and independent prognostic value for prostate cancer patients
Keeping the faith: reflections on religious nurture among young British Sikhs
Although young Sikhs are regularly accused of not attending gurdwara and not being interested in Sikhism, many young Sikhs are now learning about Sikhism outside traditional religious institutions. Using data gathered as part of a research project studying the transmission of Sikhism among 18- to 30-year-old British Sikhs, this essay explores how young Sikhs are learning about Sikhism in their pre-adult life stage. Examining the influences of the family and the school environment and the various methods used in gurdwaras, this essay offers a retrospective look on the ways in which young Sikhs are nurtured and socialised into Sikhism, providing an understanding from the perspective of young Sikhs themselves about which methods actually work and why
Ethics of Engagement and Insider-Outsider Perspectives: Issues and Dilemmas in Cross-Cultural Interpretation
This article offers insights into the ethics of engagement and methodological issues and dilemmas in cross-cultural interpretation for researchers who are positioned at different points of the insider-outsider spectrum. The discussion uses examples from qualitative research with Sikh families in Britain and focuses on the design of the methodology and co-interpretation of data from in-depth interviews, both during the interactive data gathering phase and the post-interview analysis and interpretation phase. The researchers represent differing degrees of insider-outsiderness in relation to the British Sikh community; one is a cultural insider (a Sikh) whilst the other is an outsider (non-Sikh). In other respects they share a number of characteristics, including gender, a history of migration, bilingualism and living and teaching in superdiverse communities which all impact on the nature of their engagement with the research participants and with each other as co-researchers. Our reflexive analysis shows that established binary distinctions and polarities in research practice, such as insider/outsider, are inadequate for conceptualising the fluidity and complexity of the ethics of engagement in co-researching. We argue that both theoretically and empirically a more nuanced conceptualisation reflects the realities of multiple researcher positionalities, interpretations and power relations
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