630 research outputs found
Deformations of the Boson Representation and its Subalgebras
The boson representation of the sp(4,R) algebra and two distinct deformations
of it, are considered, as well as the compact and noncompact subalgebras of
each. The initial as well as the deformed representations act in the same Fock
space.
One of the deformed representation is based on the standard q-deformation of
the boson creation and annihilation operators. The subalgebras of sp(4,R)
(compact u(2) and three representations of the noncompact u(1,1) are also
deformed and are contained in this deformed algebra. They are reducible in the
action spaces of sp(4,R) and decompose into irreducible representations.
The other deformed representation, is realized by means of a transformation
of the q-deformed bosons into q-tensors (spinor-like) with respect to the
standard deformed su(2). All of its generators are deformed and have
expressions in terms of tensor products of spinor-like operators. In this case,
an other deformation of su(2) appears in a natural way as a subalgebra and can
be interpreted as a deformation of the angular momentum algebra so(3). Its
representation is reducible and decomposes into irreducible ones that yields a
complete description of the same
HAGE (DDX43) is a biomarker for poor prognosis and a predictor of chemotherapy response in breast cancer
Background: HAGE protein is a known immunogenic cancer-specific antigen. Methods: The biological, prognostic and predictive values of HAGE expression was studied using immunohistochemistry in three cohorts of patients with BC (n=2147): early primary (EP-BC; n=1676); primary oestrogen receptor-negative (PER-BC; n=275) treated with adjuvant anthracycline-combination therapies (Adjuvant-ACT); and primary locally advanced disease (PLA-BC) who received neo-adjuvant anthracycline-combination therapies (Neo-adjuvant-ACT; n=196). The relationship between HAGE expression and the tumour-infiltrating lymphocytes (TILs) in matched prechemotherapy and postchemotherapy samples were investigated. Results: Eight percent of patients with EP-BC exhibited high HAGE expression (HAGEþ) and was associated with aggressive clinico-pathological features (Ps<0.01). Furthermore, HAGEþexpression was associated with poor prognosis in both univariate and multivariate analysis (Ps<0.001). Patients with HAGE+ did not benefit from hormonal therapy in high-risk ER-positive disease. HAGE+ and TILs were found to be independent predictors for pathological complete response to neoadjuvant-ACT; P<0.001. A statistically significant loss of HAGE expression following neoadjuvant-ACT was found (P=0.000001), and progression-free survival was worse in those patients who had HAGE+ residual disease (P=0.0003). Conclusions: This is the first report to show HAGE to be a potential prognostic marker and a predictor of response to ACT in patients with BC
Age-related changes in global motion coherence: conflicting haemodynamic and perceptual responses
Our aim was to use both behavioural and neuroimaging data to identify indicators of perceptual decline in motion processing. We employed a global motion coherence task and functional Near Infrared Spectroscopy (fNIRS). Healthy adults (n = 72, 18-85) were recruited into the following groups: young (n = 28, mean age = 28), middle-aged (n = 22, mean age = 50), and older adults (n = 23, mean age = 70). Participants were assessed on their motion coherence thresholds at 3 different speeds using a psychophysical design. As expected, we report age group differences in motion processing as demonstrated by higher motion coherence thresholds in older adults. Crucially, we add correlational data showing that global motion perception declines linearly as a function of age. The associated fNIRS recordings provide a clear physiological correlate of global motion perception. The crux of this study lies in the robust linear correlation between age and haemodynamic response for both measures of oxygenation. We hypothesise that there is an increase in neural recruitment, necessitating an increase in metabolic need and blood flow, which presents as a higher oxygenated haemoglobin response. We report age-related changes in motion perception with poorer behavioural performance (high motion coherence thresholds) associated with an increased haemodynamic response
The First Billion Years project - III: The impact of stellar radiation on the coevolution of Populations II and III
With the first metal enrichment by Population (Pop) III supernovae (SNe), the
formation of the first metal-enriched, Pop II stars becomes possible. In turn,
Pop III star formation and early metal enrichment are slowed by the high energy
radiation emitted by Pop II stars. Thus, through the SNe and radiation they
produce, Populations II and III coevolve in the early Universe, one regulated
by the other. We present large (4 Mpc)^3, high resolution cosmological
simulations in which we self-consistently model early metal enrichment and the
stellar radiation responsible for the destruction of the coolants (H2 and HD)
required for Pop III star formation. We find that the molecule-dissociating
stellar radiation produced both locally and over cosmological distances reduces
the Pop III star formation rate at z > 10 by up to an order of magnitude
compared to the case in which this radiation is not included. However, we find
that the effect of LW feedback is to enhance the amount of Pop II star
formation. We attribute this to the reduced rate at which gas is blown out of
dark matter haloes by SNe in the simulation with LW feedback, which results in
larger reservoirs for metal-enriched star formation. Even accounting for metal
enrichment, molecule-dissociating radiation and the strong suppression of
low-mass galaxy formation due to reionization at z < 10, we find that Pop III
stars are still formed at a rate of ~ 10^-5 M_sun yr^-1 Mpc^-3 down to z ~ 6.
This suggests that the majority of primordial pair-instability SNe that may be
uncovered in future surveys will be found at z < 10. We also find that the
molecule-dissociating radiation emitted from Pop II stars may destroy H2
molecules at a high enough rate to suppress gas cooling and allow for the
formation of supermassive primordial stars which collapse to form ~ 100,000
solar mass black holes.Comment: 17 pages, 11 figures; accepted for publication in MNRAS; some figures
downgraded, high resolution version available at
http://www.as.utexas.edu/~jljohnson/FiBY_III.pd
The Formation of the First Massive Black Holes
Supermassive black holes (SMBHs) are common in local galactic nuclei, and
SMBHs as massive as several billion solar masses already exist at redshift z=6.
These earliest SMBHs may grow by the combination of radiation-pressure-limited
accretion and mergers of stellar-mass seed BHs, left behind by the first
generation of metal-free stars, or may be formed by more rapid direct collapse
of gas in rare special environments where dense gas can accumulate without
first fragmenting into stars. This chapter offers a review of these two
competing scenarios, as well as some more exotic alternative ideas. It also
briefly discusses how the different models may be distinguished in the future
by observations with JWST, (e)LISA and other instruments.Comment: 47 pages with 306 references; this review is a chapter in "The First
Galaxies - Theoretical Predictions and Observational Clues", Springer
Astrophysics and Space Science Library, Eds. T. Wiklind, V. Bromm & B.
Mobasher, in pres
Prediction of pathological stage in patients with prostate cancer: a neuro-fuzzy model
The prediction of cancer staging in prostate cancer is a process for estimating the likelihood that the cancer has spread before treatment is given to the patient. Although important for determining the most suitable treatment and optimal management strategy for patients, staging continues to present significant challenges to clinicians. Clinical test results such as the pre-treatment Prostate-Specific Antigen (PSA) level, the biopsy most common tumor pattern (Primary Gleason pattern) and the second most common tumor pattern (Secondary Gleason pattern) in tissue biopsies, and the clinical T stage can be used by clinicians to predict the pathological stage of cancer. However, not every patient will return abnormal results in all tests. This significantly influences the capacity to effectively predict the stage of prostate cancer. Herein we have developed a neuro-fuzzy computational intelligence model for classifying and predicting the likelihood of a patient having Organ-Confined Disease (OCD) or Extra-Prostatic Disease (ED) using a prostate cancer patient dataset obtained from The Cancer Genome Atlas (TCGA) Research Network. The system input consisted of the following variables: Primary and Secondary Gleason biopsy patterns, PSA levels, age at diagnosis, and clinical T stage. The performance of the neuro-fuzzy system was compared to other computational intelligence based approaches, namely the Artificial Neural Network, Fuzzy C-Means, Support Vector Machine, the Naive Bayes classifiers, and also the AJCC pTNM Staging Nomogram which is commonly used by clinicians. A comparison of the optimal Receiver Operating Characteristic (ROC) points that were identified using these approaches, revealed that the neuro-fuzzy system, at its optimal point, returns the largest Area Under the ROC Curve (AUC), with a low number of false positives (FPR = 0.274, TPR = 0.789, AUC = 0.812). The proposed approach is also an improvement over the AJCC pTNM Staging Nomogram (FPR = 0.032, TPR = 0.197, AUC = 0.582)
Language in international business: a review and agenda for future research
A fast growing number of studies demonstrates that language diversity influences almost all management decisions in modern multinational corporations. Whereas no doubt remains about the practical importance of language, the empirical investigation and theoretical conceptualization of its complex and multifaceted effects still presents a substantial challenge. To summarize and evaluate the current state of the literature in a coherent picture informing future research, we systematically review 264 articles on language in international business.
We scrutinize the geographic distributions of data, evaluate the field’s achievements to date in terms of theories and methodologies, and summarize core findings by individual, group, firm, and country levels of analysis. For each of these dimensions, we then put forward a future research agenda. We encourage scholars to transcend disciplinary boundaries and to draw on, integrate, and test a variety of theories from disciplines such as psychology, linguistics, and neuroscience to gain a more profound understanding of language in international business. We advocate more multi-level studies and cross-national research collaborations and suggest greater attention to potential new data sources and means of analysis
Development of SYK NanoBRET cellular target engagement assays for gain–of–function variants
Spleen tyrosine kinase (SYK) is a non-receptor tyrosine kinase that is activated by phosphorylation events downstream of FcR, B-cell and T-cell receptors, integrins, and C-type lectin receptors. When the tandem Src homology 2 (SH2) domains of SYK bind to phosphorylated immunoreceptor tyrosine-based activation motifs (pITAMs) contained within these immunoreceptors, or when SYK is phosphorylated in interdomain regions A and B, SYK is activated. SYK gain-of-function (GoF) variants were previously identified in six patients that had higher levels of phosphorylated SYK and phosphorylated downstream proteins JNK and ERK. Furthermore, the increased SYK activation resulted in the clinical manifestation of immune dysregulation, organ inflammation, and a predisposition for lymphoma. The knowledge that the SYK GoF variants have enhanced activity was leveraged to develop a SYK NanoBRET cellular target engagement assay in intact live cells with constructs for the SYK GoF variants. Herein, we developed a potent SYK-targeted NanoBRET tracer using a SYK donated chemical probe, MRL-SYKi, that enabled a NanoBRET cellular target engagement assay for SYK GoF variants, SYK(S550Y), SYK(S550F), and SYK(P342T). We determined that ATP-competitive SYK inhibitors bind potently to these SYK variants in intact live cells. Additionally, we demonstrated that MRL-SYKi can effectively reduce the catalytic activity of SYK variants, and the phosphorylation levels of SYK(S550Y) in an epithelial cell line (SW480) stably expressing SYK(S550Y)
Unmet Medical Needs in Ulcerative Colitis: An Expert Group Consensus
BACKGROUND
The authors aimed to conduct an extensive literature review and consensus meeting to identify unmet needs in ulcerative colitis (UC) and ways to overcome them. UC is a relapsing and remitting inflammatory bowel disease with varied, and changing, incidence rates worldwide. UC has an unpredictable disease course and is associated with a high health economic burden. During 2016 and 2017, a panel of experts was convened to identify, discuss and address areas of unmet need in UC.
METHODS
PubMed and Cochrane Library databases were searched for relevant articles describing studies performed in patients with UC. These findings were used to generate a set of statements relating to unmet needs in UC. Consensus on these statements was then sought from a panel of 9 expert gastroenterologists using a modified Delphi review process that consisted of anonymous surveys followed by live meetings.
RESULTS
In 2 literature reviews, over 5,000 unique records were identified and a total of 138 articles were fully reviewed. These were used to consider 26 areas of unmet need, which were explored in 2 face-to-face meetings, in which the statements were debated and amended, resulting in consensus on 30 final statements. The unmet needs identified were categorised into 7 areas: impact of UC on patients' daily life; importance of early diagnosis and treatment; drawbacks of existing treatments; urgent need for new treatments; and disease-, practice- or patient-focused unmet needs.
CONCLUSIONS
These expert group meetings found a number of areas of unmet needs in UC, which is an important first step in tackling them in the future. Future research and development should be focused in these areas for the management of patients with UC
From Psoriasis to Psoriatic Arthritis: Decoding the Impact of Treatment Modalities on the Prevention of Psoriatic Arthritis
Introduction
Biologic therapies are licensed for both psoriasis (PsO) and psoriatic arthritis (PsA) with some electronic medical record data suggest that IL (Interleukin)-23 blockers might be more protective in PsA prevention than TNF blockers; however, the findings have been inconsistent. Higher Psoriasis Area and Severity Index (PASI) scores have also been linked to an increased PsA risk. To clarify these unresolved issues we investigated biologic agents, methotrexate, phototherapy, and topical therapy for PsA prevention in patients with psoriasis.
Methods
This retrospective cohort study analyzed data from 58,671 patients with psoriasis from the Israeli Meuhedet Health Services Organization database was evaluated for incident PsA. Patients were categorized on the basis of treatment: group 1, topical therapy; group 2, phototherapy; group 3, conventional disease-modifying antirheumatic drugs (cDMARDs; methotrexate); group 4, biologic DMARDs which was also stratified according to biologic class.
Results
The PsA incidence rate was lower in the biologic agents’ group versus the methotrexate group (HR 0.46 [95% CI 0.35–0.62]). The incidence rates per 100 person-years varied across biologic treatment groups, with the anti‑IL‑12/23 or anti‑IL‑23p19 group at 4.57, the anti-IL-17 group at 4.35, and the TNF inhibitor group at 2.55. No differences were found between various biological agents in terms of preventing PsA. The phototherapy group exhibited a higher PsA development rate than the topical therapy group (HR 1.85 [95% CI 1.65–2.07]).
Conclusion
Biological agents are more effective than methotrexate in reducing incident PsA in patients with psoriasis. This lower rate of PsA on topical therapy compared to phototherapy supports the importance of psoriasis severity as a risk factor
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