320 research outputs found
Maximal regularity in spaces for discrete time fractional shifted equations
In this paper, we are presenting a new method based on operator-valued Fourier multipliers to \- characterize the existence and uniqueness of -solutions for discrete time fractional models in the form
\Delta^{\alpha}u(n,x) = Au(n ,x) + \sum_{j=1}^k \beta_j u(n-\tau_j,x) +f(n,u(n,x)),\,\,\, n \in \mathbb{Z}, x \in \Omega \subset \mathbb{R}^N, \beta_j\in\mathbb{R}\hspace{0.1cm}\mbox{and}\hspace{0.1cm} \tau_j \in \mathbb{Z},
where is a closed linear operator defined on a Banach space and denotes the Gr\"unwald-Letnikov fractional derivative of order If is a space, we provide this characterization only in terms of the -boundedness of the operator-valued symbol associated to the abstract model. To illustrate our results, we derive new qualitative properties of nonlinear difference equations with shiftings, including fractional versions of the logistic and Nagumo equations
Sharp extensions and algebraic properties for solution families of vector-valued differential equations
In this paper we show the unexpected property that extension from local to global without loss of regularity holds for the solutions of a wide class of vector-valued differential equations, in particular for the class of fractional abstract Cauchy problems in the subdiffusive case. The main technique is the use of the algebraic structure of these solutions, which are defined by new versions of functional equations defining solution families of bounded operators. The convolution product and the double Laplace transform for functions of two variables are useful tools which we apply also to extend these solutions. Finally we illustrate our results with different concrete examples
Fundamental solutions for semidiscrete evolution equations via Banach algebras
We give representations for solutions of time-fractional differential equations that involve operators on Lebesgue spaces of sequences defined by discrete convolutions involving kernels through the discrete Fourier transform. We consider finite difference operators of first and second orders, which are generators of uniformly continuous semigroups and cosine functions. We present the linear and algebraic structures (in particular, factorization properties) and their norms and spectra in the Lebesgue space of summable sequences. We identify fractional powers of these generators and apply to them the subordination principle. We also give some applications and consequences of our results
On well-posedness of vector-valued fractional differential-difference equations
We develop an operator-theoretical method for the analysis on well posedness of partial differential-difference equations that can be modeled in the form (*) {Delta(alpha) u(n) = Au(n + 2) + f(n, u(n)), n is an element of N-0, 1 < alpha <= 2; u(0) = u(0); u(1) = u(1); where A is a closed linear operator defined on a Banach space X. Our ideas are inspired on the Poisson distribution as a tool to sampling fractional differential operators into fractional differences. Using our abstract approach, we are able to show existence and uniqueness of solutions for the problem (*) on a distinguished class of weighted Lebesgue spaces of sequences, under mild conditions on sequences of strongly continuous families of bounded operators generated by A, and natural restrictions on the nonlinearity f. Finally we present some original examples to illustrate our results
Comprehensive diagnosis in patients with morbid obesity; candidates for bariatric surgery and suggestions for preoperative treatment
Indexación: Scopus; Scielo.Objetivo
El propósito del estudio fue analizar y describir las características psicológicas, metabólicas, antropométricas y de condición física de obesos candidatos a cirugía bariátrica, para determinar la intervención preoperatoria.
Material y Métodos
La población está conformada por 24 obesos candidatos a cirugía bariátrica; cinco hombres y 19 mujeres entre 21 y 60 años. La muestra es de tipo no-probabilística, con sujetos elegidos de manera no aleatoria por conveniencia y voluntarios. Se evaluaron variables psicológicas, antropométricas, metabólicas y de condición física.
Resultados
La edad promedio de los participantes corresponde a 41,0 años. En el estudio se evidencian bajos niveles en alegría empática. Los síntomas ansiosos presentaron un nivel medio: El 62,5 % presentó depresión mínima, el 29,1 % depresión leve, y el 8,4 % depresión modera. El peso corporal tuvo un promedio de 99,1 kilogramos, la talla de 1,6 metros, el Índice de Masa Coporal (IMC) de 39,3, el porcentaje de masa grasa un promedio de 41,1 y el contorno cintura de 118,0 centímetros. Con respecto a los valores plasmáticos (mg/dl) se obtuvo: colesterol total 192,9, colesterol LDL 120,0, colesterol HDL 43,3, triglicéridos 182,3, Glicemia a 105,9; y la distancia recorrida en seis minutos fue de 511,9 metros.
Conclusiones
Los resultados aportan información para determinar mejores estrategias de intervención preoperatorias, cambiando así los estilos de vida de los pacientes; logrando que la pérdida de peso post operatoria se sostenga en el tiempo.Objective
The purpose of the study was to analyze and describe the psychological, metabolic, anthropometric and physical condition of obese candidates for bariatric surgery. This is in order to determine the preoperative intervention.
Material and Methods
The population is made up of 24 obese candidates for bariatric surgery; five men and 19 women between 21 and 60 years old. The sample type is non-probabilistic, with non-randomised subjects chosen conveniently and volunteers. Psychological, anthropometric, metabolic and physical condition variables were evaluated.
Results
The average age of participants corresponds to 41.0 years old. Low levels of empathic joy were observed. Anxiety symptoms presented an intermediate level: 62,5 % presented minimal depression, 29,1 % presented slight depression, and 8,4 % presented considerable depression. Body weight averaged 99.1 kg, height 1.6 meters, Body Mass Index (BMI) 39.3, the percentage of fat mass and contour waist averaged 41.1 118.0 centimeters in that order. With regards to plasma levels (mg / dl), the following were obtained: total cholesterol 192.9, 120.0 LDL cholesterol, HDL cholesterol, 43.3, 182.3 triglycerides, glycerin to 105.9; and distance covered in 6 minutes was 511.9 meters.
Conclusions
The results provide information to determine best Preoperative intervention strategies; changing the lifestyles of patients, keeping the postoperative weight.http://www.scielo.org.co/pdf/rsap/v19n4/0124-0064-rsap-19-04-00527.pd
Modeling of Energy Distributions in Pseudo-Rest Frame Analyses of Two-Body Decays with Missing Particles
In this study, we introduce a parametric function designed to describe the
energy distribution of the observed particle within the framework of two-body
decays involving one undetected particle, analyzed using the pseudo-rest frame
approximation. While we illustrate its effectiveness through the specific case
study of the Lepton Flavor Violating decay , this
parametric function is broadly applicable to a wide range of pseudo-rest frame
method-related searches involving undetected particles. Remarkably, it requires
only a single simulation to account for the smearing effects resulting from the
pseudo-rest frame approximation. The uniqueness of this function lies in its
dependency on the mass of the undetected particle, enabling continuous
exploration of the mass parameter space. We validate the performance of our
parametric function using simulated datasets and find that it exhibits
comparable performance to traditional simulation-based methods. Notably, our
approach offers the distinct advantage of accommodating any mass value for the
undetected particle without the need for multiple simulations.Comment: 5 pages, 7 figure
Lebesgue regularity for differential difference equations with fractional damping
We provide necessary and sufficient conditions for the existence and unique-ness of solutions belonging to the vector-valued space of sequences �(Z, X) forequations that can be modeled in the formΔu(n)+Δu(n)=Au(n)+G(u)(n)+ (n), n ∈ Z,,>0,≥0,where X is a Banach space, ∈ �(Z, X), A is a closed linear operatorwith domain D(A) defined on X,andG is a nonlinear function. The oper-ator Δdenotes the fractional difference operator of order >0inthesense of Grünwald-Letnikov. Our class of models includes the discrete timeKlein-Gordon, telegraph, and Basset equations, among other differential differ-ence equations of interest. We prove a simple criterion that shows the existenceof solutions assuming that f is small and that G is a nonlinear term
Postural stress and risk conditions in manual load handling of Chilean industrial workers
Introduction: Although, there is a current regulatory framework for optimal manual handling of loads to preserve health conditions in the industrial sector, technical assessment and the use of certain instruments are still required for the diagnosis of occupational hazards. This study aimed to identify the occupational hazards associated with manual load handling in industry workers and estimate those resulting from postural stress.
Methods: Fifty-two (52) industry workers took part in this cross-sectional study. All participants were evaluated using the Manual Handling Guide and the Reba assessment tool. Subjects were characterized, and risks associated with different tasks were detected.
Results: 59.6% of workers were between 18 and 45 years old. Lifting, lowering, and transporting loads activities had a repetitive task risk of 94%, exceeding the weight limit in 85.7% of cases. Pushing and pulling activities, mostly showed a working postural risk of 82% and a high perception of initial effort (Borg> 8). Reba score warned to intervene immediately in both types of tasks.
Conclusion: Risk from the manual handling of loads found in this study constitutes an alert that suggests reviewing compliance with the current regulation, as well as effective use of working pauses and the improvement of strategies to minimize physical efforts used by workers
Insect diversity, community composition and damage index on wild and cultivated murtilla
Plant domestication is a process in which plants’ chemical defenses that help them cope with herbivores might decline. Consequences of this process could be reflected in an increase in insect pests. Therefore, we carried out a survey to contrast the diversity, damage indexes and insect assemblages between cultivated and wild "Murtilla" (Ugni molinae) plants. The main scientific question put forward in this paper is as follows: Is there a decrease in diversity and an increase in both insect assemblages and damage indexes associated with the domestication process in U. molinae plants? The objective of this report was to compare the structure of a taxonomic assemblage collected in both wild and cultivated plants and their temporal variation over the year. Seven ecotypes and their respective wild populations were selected for these studies. The results showed higher insect assemblages in wild parents (77.35%) vs. cultivated (22.7%). The damage indexes were also higher in wild plants (0.23). The diversity indexes according to Margalef (12.98), the Shannon index (5.15) and the Simpson index (19.04) were higher in wild plants. Moreover, approximately 60 species were determínate. We detected changes in insect assemblages, damage and diversity indexes that could suggest that murtilla domestication has altered insect assemblages.M. Chacón-Fuentes, M. Lizama, L. Parra, I Seguel y A. Quiroz. 2016. Diversidad, composición de la comunidad de insectos e índice de daño, en murtillas silvestres y cultivadas. Cien. Inv. Agr. 43(1):57-67. La domesticación vegetal es un proceso en el cual las plantas pueden disminuir su nivel de defensas químicas para combatir herbívoros. Algunas de las posibles consecuencias podrían reflejarse en un incremento en el número y en la diversidad de insectos. Por lo tanto, se realizó un "survey" para comparar el índice de daño y la diversidad de insectos en plantas cultivadas y silvestres de murtilla (Ugni molinae). La principal interrogante de este trabajo fue: ¿La domesticación en plantas de murtilla, disminuirá la diversidad e incrementará el índice de daño y la comunidad de insectos? El objetivo de esta investigación fue comparar la población de insectos asociada a plantas silvestres y cultivadas además de analizar su variación durante el año. Siete ecotipos y sus correspondientes contrapartes silvestres fueron seleccionadas para este estudio. Los resultados mostraron un mayor número de insectos en plantas silvestres (77,35%) vs. (22,7%) cultivadas. El índice de daño fue mayor en plantas silvestres (0,23) comparada con plantas cultivadas. El índice de Margalef mostró la mayor riqueza de insectos en plantas cultivadas. Sin embargo, el índice de Shannon fue mayor (5.15) en plantas silvestres. Además, cerca de 60 especies de insectos fueron determinadas. Se detectaron cambios en la comunidad de insectos, índices de daño y diversidad que podrían sugerir que la domesticación en murtilla ha alterado la comunidad de insectos
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