516 research outputs found
An inspection on the Borel masses relation used in QCD sum rules
In this work, we studied the Borel masses relation used in QCDSR
calculations. These masses are the parameters of the Borel transform used when
the three point function is calculated. We analised an usual and a more general
linear relations. We concluded that a general linear relation between these
masses provides the best results regarding the standard deviation.Comment: 6 pages, 2 figures, Prepared for 11th Hadron Physic
A QCD sum rules calculation of the strong coupling constant
In this work, we calculate the form factors and the coupling constant of the
strange-charmed vertex in the framework of the QCD sum rules
by studying their three-point correlation functions. All the possible off-shell
cases are considered, , and , resulting in three different
form factors. These form factors are extrapolated to the pole of their
respective off-shell mesons, giving the same coupling constant for the process.
Our final result for the coupling constant is .Comment: 17 pages, 4 figure
Minimalist Approach for the Design of Microstructured Optical Fiber Sensors
We report on recent investigations regarding ultra-simplified designs for microstructured optical fiber sensors. This minimalist approach relies on the utilization of capillary-like fibers—namely embedded-core fibers, surface-core fibers, and capillary fibers—as platforms for the realization of sensing measurements. In these fibers, guidance of light is accomplished in an embedded or surface germanium-doped core or in the hollow part of capillaries. External stimuli can alter fiber wall thickness and/or induce birefringence variations, allowing, for the embedded-core and capillary fibers, to operate as pressure or temperature sensors. For the surface-core fiber design, the interaction between the guided mode and external medium allows the realization of refractive index sensing either by using fiber Bragg gratings or surface plasmon resonance phenomenon. Also, we report the realization of directional curvature sensing with surface-core fibers making use of the off-center core position. The attained sensitivities are comparable to the ones obtained with much more sophisticated structures. The results demonstrate that these novel geometries enable a new route toward the simplification of optical fiber sensors
PIG-1 MELK-dependent phosphorylation of nonmuscle myosin II promotes apoptosis through CES-1 Snail partitioning
The mechanism(s) through which mammalian kinase MELK promotes tumorigenesis is not understood. We find that the C. elegans orthologue of MELK, PIG-1, promotes apoptosis by partitioning an anti-apoptotic factor. The C. elegans NSM neuroblast divides to produce a larger cell that differentiates into a neuron and a smaller cell that dies. We find that in this context, PIG-1 is required for partitioning of CES-1 Snail, a transcriptional repressor of the pro-apoptotic gene egl-1 BH3-only. pig-1 MELK is controlled by both a ces-1 Snail- and par-4 LKB1-dependent pathway, and may act through phosphorylation and cortical enrichment of nonmuscle myosin II prior to neuroblast division. We propose that pig-1 MELK-induced local contractility of the actomyosin network plays a conserved role in the acquisition of the apoptotic fate. Our work also uncovers an auto-regulatory loop through which ces-1 Snail controls its own activity through the formation of a gradient of CES-1 Snail protein
Quality Indicators Compliance and Survival Outcomes in Breast Cancer according to Age in a Certified Center
Simple Summary In this study, we examined how age impacts the outcomes of breast cancer by comparing three age groups: patients 45 years old or younger, patients between 46 and 69 years old, and patients 70 years old or older. Despite similar cancer staging and tumor characteristics among the age groups, the study found that older patients were prone to suboptimal treatment. Older patients also had a lower overall survival rate, but this was not related to cancer itself. Instead, we found that undertreatment was a factor that negatively impacted survival for older women with breast cancer. This study suggests that tumor characteristics and treatment compliance are more important predictors of survival than chronological age. Age as a breast cancer (BC) prognostic factor remains debatable. Several studies have investigated clinicopathological features at different ages, but few make an age group direct comparison. The European Society of Breast Cancer Specialists quality indicators (EUSOMA-QIs) allow a standardized quality assurance of BC diagnosis, treatment, and follow-up. Our objective was to compare clinicopathological features, compliance to EUSOMA-QIs and BC outcomes in three age groups (= 70 years). Data from 1580 patients with staged 0-IV BC from 2015 to 2019 were analyzed. The minimum standard and desirable target on 19 mandatory and 7 recommended QIs were studied. The 5-year relapse rate, overall survival (OS), and BC-specific survival (BCSS) were also evaluated. No meaningful differences in TNM staging and molecular subtyping classification between age groups were found. On the contrary, disparities in QIs compliance were observed: 73.1% in = 70 years women. Despite a unique exception-more invasive G3 tumors in younger patients-no age-specific differences in BC biology impacting outcome were found. Although increased noncompliance in older women, no outcome correlation was observed with QIs noncompliance in any age group. Clinicopathological features and differences in multimodal treatment (not the chronological age) are predictors of lower BCSS.The article publication was supported by National Funds through FCT-Fundacao para a Ciencia e a Tecnologia, I.P., within CINTESIS, R & D Unit (reference UIDB/4255/2020) and within the scope of the project RISE, Associated Laboratory (reference LA/P/0053/2020). ASB, acknowledges FCT-supported funds from UnIC@RISE (UIDB/00051/2020 & UIDP/00051/2020)
vertex from QCD sum rules
The form factors and the coupling constant of the vertex are
calculated using the QCD sum rules method. Three point correlation functions
are computed considering both and mesons off-shell and, after an
extrapolation of the QCDSR results, we obtain the coupling constant of the
vertex. We study the uncertainties in our result by calculating a third form
factor obtained when the is the off-shell meson, considering other
acceptable structures and computing the variations of the sum rules'
parameters. The form factors obtained have different behaviors but their
simultaneous extrapolations reach to the same value of the coupling constant
. We compare our result with other theoretical
estimates.Comment: 11 pages, 11 figure
Competitividade de um grupo de produtores da cadeia produtiva da maçã na região de Vacaria/RS.
O objetivo deste trabalho foi identificar se um grupo de produtores da cadeia produtiva da maçã na microrregião dos Campos de Cima da Serra está enfrentando dificuldades, e quais seriam elas, bem como identificar possÃveis oportunidades que possam impactar na continuidade desta cadeia, através da metodologia de pesquisa exploratória, com caráter qualitativo e quantitativo quanto à abordagem metodológica, e, descritivo-explicativa quanto aos objetivos e levantamento de bibliografia. A coleta de informações foi realizada pelo método de entrevistas semiestruturadas, por meio de questionário. Os resultados indicaram que os produtores vêm enfrentando problemas de ordem produtiva e comercial, como fatores vinculados à mão de obra e clima, estabilização de preços, baixo consumo nacional da fruta, dentre outros, podendo ser amenizados pela introdução de técnicas, variedades e controle de custos. Além disso, a introdução paralela de novas culturas similares, como uva e pêra, pode aperfeiçoar o processo produtivo pela redução do custo. Palavras-chave: Maleicultura, produtividade, competitividade
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