98 research outputs found
Edge Guided Reconstruction for Compressive Imaging
We propose EdgeCSâan edge guided compressive sensing reconstruction approachâto recover images
of higher quality from fewer measurements than the current methods. Edges are important
image features that are used in various ways in image recovery, analysis, and understanding. In
compressive sensing, the sparsity of image edges has been successfully utilized to recover images.
However, edge detectors have not been used on compressive sensing measurements to improve the
edge recovery and subsequently the image recovery. This motivates us to propose EdgeCS, which
alternatively performs edge detection and image reconstruction in a mutually beneficial way. The
edge detector of EdgeCS is designed to faithfully return partial edges from intermediate image reconstructions
even though these reconstructions may still have noise and artifacts. For complex-valued
images, it incorporates joint sparsity between the real and imaginary components. EdgeCS has
been implemented with both isotropic and anisotropic discretizations of total variation and tested
on incomplete k-space (spectral Fourier) samples. It applies to other types of measurements as well.
Experimental results on large-scale real/complex-valued phantom and magnetic resonance (MR)
images show that EdgeCS is fast and returns high-quality images. For example, it exactly recovers
the 256Ă256 SheppâLogan phantom from merely 7 radial lines (3.03% k-space), which is impossible
for most existing algorithms. It is able to accurately reconstruct a 512 Ă 512 MR image with 0.05
white noise from 20.87% radial samples. On complex-valued MR images, it obtains recoveries with
faithful phases, which are important in many medical applications. Each of these tests took around
30 seconds on a standard PC. Finally, the algorithm is GPU friendly
Expression of LIM kinase 1 is associated with reversible G1/S phase arrest, chromosomal instability and prostate cancer
<p>Abstract</p> <p>Background</p> <p>LIM kinase 1 (LIMK1), a LIM domain containing serine/threonine kinase, modulates actin dynamics through inactivation of the actin depolymerizing protein cofilin. Recent studies have indicated an important role of LIMK1 in growth and invasion of prostate and breast cancer cells; however, the molecular mechanism whereby LIMK1 induces tumor progression is unknown. In this study, we investigated the effects of ectopic expression of LIMK1 on cellular morphology, cell cycle progression and expression profile of LIMK1 in prostate tumors.</p> <p>Results</p> <p>Ectopic expression of LIMK1 in benign prostatic hyperplasia cells (BPH), which naturally express low levels of LIMK1, resulted in appearance of abnormal mitotic spindles, multiple centrosomes and smaller chromosomal masses. Furthermore, a transient G1/S phase arrest and delayed G2/M progression was observed in BPH cells expressing LIMK1. When treated with chemotherapeutic agent Taxol, no metaphase arrest was noted in these cells. We have also noted increased nuclear staining of LIMK1 in tumors with higher Gleason Scores and incidence of metastasis.</p> <p>Conclusion</p> <p>Our results show that increased expression of LIMK1 results in chromosomal abnormalities, aberrant cell cycle progression and alteration of normal cellular response to microtubule stabilizing agent Taxol; and that LIMK1 expression may be associated with cancerous phenotype of the prostate.</p
Design and statistics of pharmacokinetic drug-drug, herb-drug, and food-drug interaction studies in oncology patients
Polypharmacy is becoming increasingly prevalent in society. Patients with polypharmacy are at greater risk for drug-drug interactions, which can influence the efficacy of treatment. Especially, in oncology this is a concern since neoplasms are increasing prevalent with age, as well as polypharmacy is. Besides drug-drug interactions, also herb-drug and food-drug interactions could be present. Knowledge of these interactions is of great importance for safe and effective anti-cancer treatment, because the therapeutic window of most of these oncologic drugs are small. To study pharmacokinetic interaction effects, a cross-over pharmacokinetic study is a widely used, efficient and scientifically robust design. Yet, several aspects need to be considered when carrying out an interaction study. This includes the knowledge of the advantages and disadvantages of a cross-over design. Furthermore, determination of the end point and research question of interest, calculation of the required sample size, analysis of the generated data with a robust statistical plan and consideration of the logtransformation for some pharmacokinetic parameters are important aspects to consider. Even though some guidelines exist regarding these key issues, no clear overview exists. In this article an overview of these aspects is provided and their effect is discussed
Shifting Characterizations of the âCommon Peopleâ in Modern English Retranslations of Thucydidesâ History of the Peloponnesian War: A corpus-based analysis
Little research has yet explored the impact of (re)translation on narrative characterization, that is, on the process through which the various actors depicted in a narrative are attributed particular traits and qualities. Moreover, the few studies that have been published on this topic are either rather more anecdotal than systematic, or their focus is primarily on the losses in character information that inevitably occur when a narrative is retold for a new audience in a new linguistic context. They do not explore how the translatorâs own background knowledge and ideological beliefs might affect the characterization process for readers of their target-language text. Consequently, this paper seeks to make two contributions to the field: first, it presents a corpus-based methodology developed as part of the Genealogies of Knowledge project for the comparative analysis of characterization patterns in multiple retranslations of a single source text. Such an approach is valuable, it is argued, because it can enhance our ability to engage in a more systematic manner with the accumulation of characterization cues spread throughout a narrative. Second, the paper seeks to move discussions of the effects of translation on narrative characterization away from a paradigm of loss, deficiency and failure, promoting instead a perspective which embraces the productive role translators often play in reconfiguring the countless narratives through which we come to know, imagine and make sense of the past, our present and futures. The potential of this methodology and theoretical standpoint is illustrated through a case study exploring changes in the characterization of âthe common peopleâ in two English-language versions of classical Greek historian Thucydidesâ History of the Peloponnesian War, the first produced by Samuel Bloomfield in 1829 and the second by Steven Lattimore in 1998. Particular attention is paid to the referring expressions used by each translatorâsuch as the multitude vs. the common peopleâas well as the specific attributes assigned to this narrative actor. In this way, the study attempts to gain deeper insight into the ways in which these translations reflect important shifts in attitudes within key political debates concerning the benefits and dangers of democracy
Tumour brain: preâtreatment cognitive and affective disorders caused by peripheral cancers
People that develop extracranial cancers often display co-morbid neurological disorders, such as anxiety, depression and cognitive impairment, even before commencement of chemotherapy. This suggests bidirectional crosstalk between non-CNS tumours and the brain, which can regulate peripheral tumour growth. However, the reciprocal neurological effects of tumour progression on brain homeostasis are not well understood. Here, we review brain regions involved in regulating peripheral tumour development and how they, in turn, are adversely affected by advancing tumour burden. Tumour-induced activation of the immune system, bloodâbrain barrier breakdown and chronic neuroinflammation can lead to circadian rhythm dysfunction, sleep disturbances, aberrant glucocorticoid production, decreased hippocampal neurogenesis and dysregulation of neural network activity, resulting in depression and memory impairments. Given that cancer-related cognitive impairment diminishes patient quality of life, reduces adherence to chemotherapy and worsens cancer prognosis, it is essential that more research is focused at understanding how peripheral tumours affect brain homeostasis
Molecular diversity of Campylobacter coli and C. jejuni isolated from pigs at slaughter by flaA-RFLP analysis and ribotyping
- âŠ