7,170 research outputs found
Reconciling threshold and subthreshold expansions for pion-nucleon scattering
Heavy-baryon chiral perturbation theory (ChPT) at one loop fails in relating
the pion-nucleon amplitude in the physical region and for subthreshold
kinematics due to loop effects enhanced by large low-energy constants. Studying
the chiral convergence of threshold and subthreshold parameters up to fourth
order in the small-scale expansion, we address the question to what extent this
tension can be mitigated by including the as an explicit degree
of freedom and/or using a covariant formulation of baryon ChPT. We find that
the inclusion of the indeed reduces the low-energy constants to more
natural values and thereby improves consistency between threshold and
subthreshold kinematics. In addition, even in the -less theory the
resummation of corrections in the covariant scheme improves the results
markedly over the heavy-baryon formulation, in line with previous observations
in the single-baryon sector of ChPT that so far have evaded a profound
theoretical explanation.Comment: 10 pages, 4 tables, Mathematica notebook with the analytic
expressions for threshold and subthreshold parameters included as
supplementary material; journal versio
Pion-nucleon scattering in covariant baryon chiral perturbation theory with explicit Delta resonances
We present the results of a third order calculation of the pion-nucleon
scattering amplitude in a chiral effective field theory with pions, nucleons
and delta resonances as explicit degrees of freedom. We work in a manifestly
Lorentz invariant formulation of baryon chiral perturbation theory using
dimensional regularization and the extended on-mass-shell renormalization
scheme. In the delta resonance sector, the on mass-shell renormalization is
realized as a complex-mass scheme. By fitting the low-energy constants of the
effective Lagrangian to the - and -partial waves a satisfactory
description of the phase shifts from the analysis of the Roy-Steiner equations
is obtained. We predict the phase shifts for the and waves and compare
them with the results of the analysis of the George Washington University
group. The threshold parameters are calculated both in the delta-less and
delta-full cases. Based on the determined low-energy constants, we discuss the
pion-nucleon sigma term. Additionally, in order to determine the strangeness
content of the nucleon, we calculate the octet baryon masses in the presence of
decuplet resonances up to next-to-next-to-leading order in SU(3) baryon chiral
perturbation theory. The octet baryon sigma terms are predicted as a byproduct
of this calculation.Comment: 41 pages, 12 figures, 7 table
EFEMP1 binds the EGF receptor and activates MAPK and Akt pathways in pancreatic carcinoma cells
The EGF-related protein EFEMP1 (EGF-containing fibulin-like extracellular matrix protein 1) has been shown to promote tumor growth in human adenocarcinoma. To understand the mechanism of this action, the signal transduction activated upon treatment with this protein has been investigated. We show that EFEMP1 binds EGF receptor (EGFR) in a competitive manner relative to epidermal growth factor (EGF), implicating that EFEMP1 and EGF share the same or adjacent binding sites on the EGFR. Treatment of pancreatic carcinoma cells with purified EFEMP1 activates autophosphorylation of EGFR at the positions Tyr-992 and Tyr-1068, but not at the position Tyr-1048. This signal is further transduced to phosphorylation of Akt at position Thr-308 and p44/p42 MAPK (mitogen-activated protein kinase) at positions Thr-202 and Tyr-204. These downstream phosphorylation events can be inhibited by treatment with the EGFR kinase inhibitor PD 153035. The observed signal transduction upon treatment with EFEMP1 can contribute to the enhancement of tumor growth shown in pancreatic carcinoma cells overexpressing EFEMP1
Complete blood count and C-reactive protein to predict positive blood culture among neonates using machine learning algorithms
Purpose: The authors aimed to develop a Machine-Learning (ML) algorithm that can predict positive blood culture in the neonatal intensive care unit, using complete blood count and C-reactive protein values.
Methods: The study was based on patients’ electronic health records at a tertiary neonatal intensive care unit in São Paulo, Brazil. All blood cultures that had paired complete blood count and C-reactive protein measurements taken at the same time were included. To evaluate the machine learning model's performance, the authors used accuracy, Area Under the Receiver Operating Characteristics (AUROC), recall, precision, and F1-score.
Results: The dataset included 1181 blood cultures with paired complete blood count plus c-reactive protein and 1911 blood cultures with paired complete blood count only. The f1-score ranged from 0.14 to 0.43, recall ranged from 0.08 to 0.59, precision ranged from 0.29 to 1.00, and accuracy ranged from 0.688 to 0.864.
Conclusion: Complete blood count parameters and C-reactive protein levels cannot be used in ML models to predict bacteremia in newborns
Efficacy of remotely-delivered cognitive behavioural therapy for obsessive compulsive disorder: An updated meta-analysis of randomised controlled trials
INTRODUCTION: Despite remotely-delivered cognitive behavioural therapy (CBT) being an emerging field, the evidence of its efficacy in obsessive-compulsive disorder (OCD) is limited. We aimed to estimate the efficacy of remotely-delivered CBT for OCD, compared to face-to-face CBT and non-CBT control conditions. METHODS: Randomised clinical trials (RCTs) identified through a systematic literature search of PubMed, Ovid/PsychINFO and Web of Science until 21/06/2021. Eligible studies included individuals with OCD evaluating at least one form of remotely-delivered CBT versus a control condition. Random-effects meta-analyses, sub-analyses, meta-regressions, heterogeneity analyses, publication bias assessment and quality assessment. RESULTS: Twenty-two RCTs were included (n = 1796, mean age = 27.7 years, females = 59.1 %). Remotely-delivered CBT was more efficacious than non-CBT control conditions for OCD symptoms (g = 0.936 95 % CI = 0.597-1.275, p < .001), depressive symptoms (g = 0.358, 95 % CI = 0.125-0.590, p = .003) and anxiety symptoms (g = 0.468, 95 % CI = 0.135-0.800, p = .006). There were no significant differences in efficacy between remotely-delivered CBT and face-to-face CBT for OCD symptoms (g = −0.104 95 % CI = −0.391-0.184, p = .479), depressive symptoms (g = 0.138, 95 % CI = −0.044-0.320, p = .138), anxiety symptoms (g = 0.166, 95 % CI = −0.456-0.780, p = .601) or quality of life (g = 0.057, 95 % CI = −0.178-0.292, p = .489). Higher baseline severity of OCD symptoms was associated with a lower efficacy of remotely-delivered CBT compared to face-to-face CBT (β = −0.092, p = .036). The quality of the included studies was mostly identified as “low risk of bias” (45.5 %) or “some concerns” (45.5 %). LIMITATIONS: Heterogeneity and limited evidence for some outcomes. CONCLUSIONS: Remotely-delivered CBT appears efficacious in reducing OCD symptoms and other relevant outcomes and is therefore a viable option for increasing treatment access. Preliminary evidence suggests some individuals with severe OCD may benefit more from face-to-face than remotely-delivered CBT
A Inserção no Mercado de Trabalho dos Egressos do Curso de Turismo e Hotelaria da Universidade do Vale do Itajaí
O turismo vem apresentando índices de crescimento expressivos e se desenvolvendo de maneira extremamente veloz, consolidando-se como atividade econômica, social, cultural e ambiental bastante significativa. Este artigo teve por objetivo avaliar a satisfação dos egressos do Curso de Turismo e Hotelaria da Universidade do Vale do Itajaí, Campus Balneário Camboriú – Santa Catarina, com relação a sua inserção no mercado de trabalho. Para tanto, foi utilizado questionário, sendo pesquisados os formando dos anos de 2001 e 2002. A população correspondente é de 160 (cento e sessenta) egressos, sendo a amostra de 73 (setenta e três). Os resultados obtidos demonstraram que a maioria dos entrevistados está atuando, principalmente na área de hotelaria, sendo que 88% fariam o Curso novamente. Entre as dificuldades apontadas, é relevante o fato de que o mercado turístico carece de profissionalismo. Diante disso, o ensino superior e o mercado turístico não podem mais ser conduzidos de forma empírica, por meio de improvisações ou esquemas amadorísticos
Exact density profiles for fully asymmetric exclusion process with discrete-time dynamics
Exact density profiles in the steady state of the one-dimensional fully
asymmetric simple exclusion process on semi-infinite chains are obtained in the
case of forward-ordered sequential dynamics by taking the thermodynamic limit
in our recent exact results for a finite chain with open boundaries. The
corresponding results for sublattice parallel dynamics follow from the
relationship obtained by Rajewsky and Schreckenberg [Physica A 245, 139 (1997)]
and for parallel dynamics from the mapping found by Evans, Rajewsky and Speer
[J. Stat. Phys. 95, 45 (1999)]. By comparing the asymptotic results appropriate
for parallel update with those published in the latter paper, we correct some
technical errors in the final results given there.Comment: About 10 pages and 3 figures, new references are added and a
comparison is made with the results by de Gier and Nienhuis [Phys. Rev. E 59,
4899(1999)
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