55 research outputs found
Drag force in a strongly coupled anisotropic plasma
We calculate the drag force experienced by an infinitely massive quark
propagating at constant velocity through an anisotropic, strongly coupled N=4
plasma by means of its gravity dual. We find that the gluon cloud trailing
behind the quark is generally misaligned with the quark velocity, and that the
latter is also misaligned with the force. The drag coefficient can be
larger or smaller than the corresponding isotropic value depending on the
velocity and the direction of motion. In the ultra-relativistic limit we find
that generically . We discuss the conditions under which this
behaviour may extend to more general situations.Comment: 25 pages, 13 figures; v2: minor changes, added reference
Relative quantification of TCR Vbeta-chain families by real time PCR for identification of clonal T-cell populations
As cold as a fish? Relationships between the Dark Triad personality traits and affective experience during the day: A day reconstruction study
The Dark Triad of personality is a cluster of three socially aversive personality traits: Machiavellianism,
narcissism and psychopathy. These traits are associated with a selfish, aggressive
and exploitative interpersonal strategy. The objective of the current study was to
establish relationships between the Dark Triad traits (and their dimensions) and momentary
affect. Machiavellianism, grandiose narcissism, vulnerable narcissism and the dimensions
of the Triarchic model of psychopathy (namely, boldness, meanness and disinhibition) were
examined. We used the Day Reconstruction Method, which is based on reconstructing
affective states experienced during the previous day. The final sample consisted of 270 university
students providing affective ratings of 3047 diary episodes. Analyses using multilevel
modelling showed that only boldness had a positive association with positive affective states
and affect balance, and a negative association with negative affective states. Grandiose
narcissism and its sub-dimensions had no relationship with momentary affect. The other
dark traits were related to negative momentary affect and/or inversely related to positive
momentary affect and affect balance. As a whole, our results empirically demonstrated distinctiveness
of the Dark Triad traits in their relationship to everyday affective states. These
findings are not congruent with the notion that people with the Dark Triad traits, who have a
dispositional tendency to manipulate and exploit others, are generally cold and invulnerable
to negative feelings. The associations between the Dark Triad and momentary affect were
discussed in the contexts of evolutionary and positive psychology, in relation to the role and
adaptive value of positive and negative emotions experienced by individuals higher in
Machiavellianism, narcissism and psychopathy
Cancer Biomarker Discovery: The Entropic Hallmark
Background: It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods. Methodology/Principal Findings: Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer. Conclusions/Significance: We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-throughput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases
Renal association clinical practice guideline in post-operative care in the kidney transplant recipient
These guidelines cover the care of patients from the period following kidney transplantation until the transplant is no longer working or the patient dies. During the early phase prevention of acute rejection and infection are the priority. After around 3-6 months, the priorities change to preservation of transplant function and avoiding the long-term complications of immunosuppressive medication (the medication used to suppress the immune system to prevent rejection). The topics discussed include organization of outpatient follow up, immunosuppressive medication, treatment of acute and chronic rejection, and prevention of complications. The potential complications discussed include heart disease, infection, cancer, bone disease and blood disorders. There is also a section on contraception and reproductive issues.Immediately after the introduction there is a statement of all the recommendations. These recommendations are written in a language that we think should be understandable by many patients, relatives, carers and other interested people. Consequently we have not reworded or restated them in this lay summary. They are graded 1 or 2 depending on the strength of the recommendation by the authors, and AD depending on the quality of the evidence that the recommendation is based on
MHC multimer-guided and cell culture-independent isolation of functional T cell receptors from single cells facilitates TCR identification for immunotherapy.
Adoptive therapy using T cells redirected to target tumor- or infection-associated antigens is a promising strategy that has curative potential and broad applicability. In order to accelerate the screening process for suitable antigen-specific T cell receptors (TCRs), we developed a new approach circumventing conventional in vitro expansion-based strategies. Direct isolation of paired full-length TCR sequences from non-expanded antigen-specific T cells was achieved by the establishment of a highly sensitive PCR-based T cell receptor single cell analysis method (TCR-SCAN). Using MHC multimer-labeled and single cell-sorted HCMV-specific T cells we demonstrate a high efficacy (approximately 25%) and target specificity of TCR-SCAN receptor identification. In combination with MHC-multimer based pre-enrichment steps, we were able to isolate TCRs specific for the oncogenes Her2/neu and WT1 even from very small populations (original precursor frequencies of down to 0.00005% of CD3(+) T cells) without any cell culture step involved. Genetic re-expression of isolated receptors demonstrates their functionality and target specificity. We believe that this new strategy of TCR identification may provide broad access to specific TCRs for therapeutically relevant T cell epitopes
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