A mathematical model for fluid-glucose-albumin transport in peritoneal dialysis

A mathematical model for fluid and solute transport in peritoneal dialysis is constructed. The model is based on a three-component nonlinear system of two-dimensional partial differential equations for fluid, glucose and albumin transport with the relevant boundary and initial conditions. Its aim is to model ultrafiltration of water combined with inflow of glucose to the tissue and removal of albumin from the body during dialysis, and it does this by finding the spatial distributions of glucose and albumin concentrations and hydrostatic pressure. The model is developed in one spatial dimension approximation and a governing equation for each of the variables is derived from physical principles. Under certain assumptions the model are simplified with the aim of obtaining exact formulae for spatially non-uniform steady-state solutions. As the result, the exact formulae for the fluid fluxes from blood to tissue and across the tissue are constructed together with two linear autonomous ODEs for glucose and albumin concentrations in the tissue. The obtained analytical results are checked for their applicability for the description of fluid-glucose-albumin transport during peritoneal dialysis.Comment: 28 pages, 8 figures. arXiv admin note: text overlap with arXiv:1110.128

Local Dimensions of Global Responsibility

A report from the conference held in the Maria Grzegorzewska University (Warsaw, May 30, 2014

Constraint As an Ethical Postulate in the Context of Ecological Limits

The problem of natural resources being finite as well as the capability of ecosystems and the biosphere to assimilate the effects of economic activity on the one hand, and growing economic discrepancies on the other raise a question mark over the chase after the unrestrained economic growth. In the search for alternative models of thinking and development a significant role of constraint is being more and more emphasized. In the case of ecological barriers limitation of using non-renewable resources, greenhouse gases emissions, excessive consumption and production seems to be a reasonable strategy that manifests our care for the natural environment.The aim of the paper is to demonstrate that the postulate of constraint present in the de-growth model in the form proposed by Tim Jackson and Serge Latouche apart from a quantitative dimension has, above all, a qualitative and ethically orientated dimension. Constraint conceived in the above way stays close to terms like moderation, restraint, sustainability, i.e. such terms that possess solid ethical foundations and constitute an important base for environmental ethics.

A Mathematical Model for Two Solutes Transport in a Poroelastic Material and Its Applications

Using well-known mathematical foundations of the elasticity theory, a mathematical model for two solutes transport in a poroelastic material (soft tissue is a typical example) is suggested. It is assumed that molecules of essentially different sizes dissolved in fluid and are transported through pores of different sizes. The stress tensor, the main force leading to the material deformation, is taken not only in the standard linear form but also with an additional nonlinear part. The model is constructed in 1D space and consists of six nonlinear equations. It is shown that the governing equations are integrable in stationary case, therefore all steady-state solutions are constructed. The obtained solutions are used in an example for healthy and tumour tissue, in particular, tissue displacements are calculated and compared for parameters taken from experimental data in cases of the linear and nonlinear stress tensors. Since the governing equations are non-integrable in non-stationary case, the Lie symmetry analysis is used in order to construct time-dependent exact solutions. Depending on parameters arising in the governing equations, several special cases with non-trivial Lie symmetries are identified. As a result, multi-parameter families of exact solutions are constructed including those in terms of special functions(hypergeometric and Bessel functions). A possible application of the solutions obtained is demonstrated.Comment: 6 figure

Jakość relacji z przełożonymi jako czynnik determinujący zaangażowanie pracowników (na przykładzie uczelni wyższej)

We współczesnych uwarunkowaniach problematyka dotycząca kształtowania zaangażowania pracowników, będącego czynnikiem o kluczowym znaczeniu dla osiągania celów organizacji, a zarazem wyznacznikiem skuteczności zarządzania kapitałem ludzkim, jest ważna z punktu widzenia każdej organizacji, w tym również uczelni wyższych. W procesie budowania zaangażowania pracowników istotną rolę odgrywa identyfikacja znaczenia różnorodnych czynników determinujących jego poziom. Jednym z takich czynników jest jakość relacji z bezpośrednimi przełożonymi. Podstawowym celem badania prezentowanego w niniejszym artykułu była identyfikacja znaczenia jakości relacji z przełożonymi jako jednego z czynników kształtujących zaangażowanie pracowników Uniwersytetu Warmińsko‑Mazurskiego w Olsztynie. Badanie służące realizacji celu zostało przeprowadzone metodą ankietową wśród nauczycieli akademickich oraz osób niebędących nauczycielami akademickimi

Wykorzystanie narzędzi komunikacji społecznej w budowaniu zewnętrznego wizerunku pracodawcy z wyboru

Działania z zakresu świadomego budowania wizerunku pracodawcy z wyboru coraz częściej zasilają wachlarz praktyk wspomagających zarządzanie zasobami ludzkimi w organizacjach. Employer branding, który można określić jako długoterminową strategię przyciągania, angażowania i zatrzymywania w firmie najbardziej utalentowanych, wartościowych pracowników, uznawany jest za jeden z niezwykle ważnych czynników sukcesu organizacji. Celem niniejszego opracowania jest zwrócenie uwagi na rolę narzędzi komunikacji społecznej w procesie zewnętrznego budowania silnej, pozytywnej marki pracodawcy, ze szczególnym uwzględnieniem znaczenia narzędzi internetowych

Competencies of sales employees as a determinant of the quality of provided services based on the insurance market

Purpose: The main goal of the research presented in this paper was to assess the factors determining the quality of services provided by an insurance agent with particular emphasis on the importance of an employee’s competencies. Design/Methodology/Approach: To this end, the Servqual method was employed to survey the clients of insurance agents. This method evaluates the quality of the experienced service and that of the expected service and identifies discrepancies in the customers’ expectations. The customers assessed five dimensions (tangibles, reliability, responsiveness to the customer’s expectations, assurance, and empathy), to which 22 factors have been assigned. Findings: The survey results proved the assurance and tangibles to be the most and the least essential dimensions. The factors that were of vital importance to the customers included building trust by a sales employee and a high level of his/her knowledge and flawless documentation. The most significant gap between the actual and the expected quality was noticed for the following factors: ensuring the best satisfaction of customer needs and providing services effectively and on time. Practical Implications: The conducted research has confirmed that the quality of provided services requires constant monitoring, verifying the market situation, and improving employees’ competencies in the sustainable development of the economy. The insurance awareness of a Polish customer increases; therefore, agents should improve their skills to meet customers’ requirements, striving to ensure their satisfaction. Originality/Value: The paper adds to the discussion on the competencies of sales employees as a determinant of the quality of provided services based on the insurance market. It broadens knowledge on the relationship between competencies of sales employees and quality of services.peer-reviewe

Non-alcoholic fatty liver disease (NAFLD) – epidemic of the XXI century

The term “non-alcoholic fatty liver disease” (NAFLD) was first introduced by Ludwig in 1980. He described NAFLD as a liver disease characterized by lipid accumulation in the hepatocytes of people who do not abuse alcohol (<20g/ethanol/day). NAFLD comprises of a range of disorders, including simple fatty liver without the symptoms of damaged hepatocytes, as well as complex fatty liver with an ongoing inflammation and developing fibrosis. It is estimated that 2-44% of adult Europeans will develop a fatty liver. The pathogenesis and development of NAFLD is a complicated process involving numerous factors, such as: dyslipidemia, insulin resistance, overweight, obesity, mitochondrial dysfunction, oxidative stress, the development of an inflammatory state, the disorders of the metabolism of fat tissue, dysbiosis and genetic factors. Because the mechanism of the illness is based on many factors, the multiple hits hypothesis serves as the new and generally standard approach to this pathological unit. The basis of this theory is the development of insulin resistance, which is one of the main causes of steatosis. The consequence of insulin resistance is an increased glucose level (associated with impaired insulin receptors) and excessive insulin production leading to elevated levels of this hormone in the serum. Insulin resistance causes continuous stimulation of gluconeogenesis and hyperglycemia. On the other hand, hyperinsulinemia stimulates the hepatic synthesis of the de novo lipogenesis and leads to steatosis. NAFLD is also closely connected to the metabolism disorders of fatty acids. The pathomechanism of the illness includes an increased concentration of FFA in blood, an increase in the biosynthesis of fatty acids in the liver, as well as disorders in the process of β-oxidation