367 research outputs found

    Systems thinking in project management : theoretical framework and empirical evidence from Polish companies

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    This research examines new directions in project management and systems thinking theory and practice. Relevant literature is synthesized to provide a holistic picture of current knowledge of the topic, highlighting meanings, principles, prerequisites, process and consequences. The major aim of the research is to investigate the nature of systems thinking in project management. The research methodology was divided into two phases: (1) designing a theoretical framework for applying systems thinking into project management; (2) evaluating project management practices of enterprises in Poland, to identify their approaches, actions, methods and problems related to the application of systems thinking in project management. Conducted research has shown that there is a gap in the field of systems thinking in project management, which can be seen in the divergence of expectations of executive management with management practices in this regardPrzedmiotem opracowania są nowe kierunki badań w zarządzaniu projektami oraz myśleniu sieciowym. Przedstawiono wyniki badań literaturowych ukazujących całościowy przegląd aktualnej wiedzy z przedmiotowego zakresu, wyjaśniając podstawowe pojęcia, reguły, przesłanki, procesy oraz ich konsekwencje. Podstawowym celem opracowania jest określenie istoty myślenia systemowego w zarządzaniu projektami. Postępowanie badawcze podzielono na dwie podstawowe części: (1) zaproponowanie koncepcji teoretycznego modelu wykorzystania myślenia systemowego w zarządzaniu projektami, oraz (2) ocenę praktyki zarządzania projektami w polskich przedsiębiorstwach, ukierunkowaną na identyfikację stosowanego podejścia, działań, metod i problemów związanych z aplikacją myślenia systemowego w zarządzaniu projektami. Przeprowadzone badania potwierdziły występowanie luki w stosowaniu myślenia systemowego w zarządzaniu projektami, związanej z rozbieżnością pomiędzy oczekiwaniami naczelnego kierownictwa a praktyką działań kierowniczyc

    Beneficial effect of voluntary exercise on experimental colitis in mice fed a high-fat diet : the role of irisin, adiponectin and proinflammatory biomarkers

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    Inflammatory bowel diseases (IBDs) are a heterogeneous group of disorders exhibited by two major phenotypic forms: Crohn‘s disease and ulcerative colitis. Although the aetiology of IBD is unknown, several factors coming from the adipose tissue and skeletal muscles, such as cytokines, adipokines and myokines, were suggested in the pathogenesis of ulcerative colitis; however, it has not been extensively studied whether voluntary exercise can ameliorate that disorder. We explored the effect of moderate exercise (i.e., voluntary wheel running) on the disease activity index (DAI), colonic blood flow (CBF), plasma irisin and adiponectin levels and real-time PCR expression of proinflammatory markers in mesenteric fat in mice with 2,4,6-trinitrobenzenesulfonic acid (TNBS) colitis fed a high-fat diet (HFD) compared to those on a standard chow diet (SD). Macroscopic and microscopic colitis in sedentary SD mice was accompanied by a significant fall in CBF, some increase in colonic tissue weight and a significant increase in the plasma levels of tumour necrosis factor-alpha (TNF-α), IL-6, monocyte chemotactic protein 1 (MCP-1) and IL-13 (p < 0.05). In sedentary HFD mice, colonic lesions were aggravated, colonic tissue weight increased and the plasma TNF-α, IL-6, MCP-1, IL-1β and leptin levels significantly increased. Simultaneously, a significant decrease in the plasma irisin and adiponectin levels was observed in comparison with SD mice (p < 0.05). Exercise significantly decreased macroscopic and microscopic colitis, substantially increased CBF and attenuated the plasma TNF-α, IL-6, MCP-1, IL-1β and leptin levels while raising the plasma irisin and the plasma and WAT concentrations of adiponectin in HFD mice (p < 0.05). We conclude that: (1) experimental colitis is exacerbated in HFD mice, possibly due to a fall in colonic microcirculation and an increase in the plasma and mesenteric fat content of proinflammatory biomarkers; and (2) voluntary physical activity can attenuate the severity of colonic damage in mice fed a HFD through the release of protective irisin and restoration of plasma adiponectin

    Carbon monoxide being hydrogen sulfide and nitric oxide molecular sibling, as endogenous and exogenous modulator of oxidative stress and antioxidative mechanisms in the digestive system

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    Oxidative stress reflects an imbalance between oxidants and antioxidants in favor of the oxidants capable of evoking tissue damage. Like hydrogen sulfide (H2S) and nitric oxide (NO), carbon monoxide (CO) is an endogenous gaseous mediator recently implicated in the physiology of the gastrointestinal (GI) tract. CO is produced in mammalian tissues as a byproduct of heme degradation catalyzed by the heme oxygenase (HO) enzymes. Among the three enzymatic isoforms, heme oxygenase-1 (HO-1) is induced under conditions of oxidative stress or tissue injury and plays a beneficial role in the mechanism of protection against inflammation, ischemia/reperfusion (I/R), and many other injuries. According to recently published data, increased endogenous CO production by inducible HO-1, its delivery by novel pharmacological CO-releasing agents, or even the direct inhalation of CO has been considered a promising alternative in future experimental and clinical therapies against various GI disorders. However, the exact mechanisms underlying behind these CO-mediated beneficial actions are not fully explained and experimental as well as clinical studies on the mechanism of CO-induced protection are awaited. For instance, in a variety of experimental models related to gastric mucosal damage, HO-1/CO pathway and CO-releasing agents seem to prevent gastric damage mainly by reduction of lipid peroxidation and/or increased level of enzymatic antioxidants, such as superoxide dismutase (SOD) or glutathione peroxidase (GPx). Many studies have also revealed that HO-1/CO can serve as a potential defensive pathway against oxidative stress observed in the liver and pancreas. Moreover, increased CO levels after treatment with CO donors have been reported to protect the gut against formation of acute GI lesions mainly by the regulation of reactive oxygen species (ROS) production and the antioxidative activity. In this review, we focused on the role of H2S and NO molecular sibling, CO/HO pathway, and therapeutic potential of CO-releasing pharmacological tools in the regulation of oxidative stress-induced damage within the GI tract with a special emphasis on the esophagus, stomach, and intestines and also two solid and important metabolic abdominal organs, the liver and pancreas

    MicroRNAs and chronic inflammation contribution to gastrointestinal integrity

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    Recent studies have revealed that chronic inflammation represents a major basis for different forms of human malignancies. Chronic inflammations are involved in the pathogenesis of 15-25% of human malignancies. Gastrointestinal (GI) cancer is one of the most common causes of mortality in the European Union. The mechanisms leading to cancer development and its progression are not completely understood. Advances are required both in early detection and therapy of GI cancers. There are many factors connecting inflammation and cancer. Cytokines that are small protein molecules regulating growth, differentiation, development and immune response mechanisms in cells. Overexpression of cyclooxynenase-2 is associated with decreased apoptosis, cell to cell adhesion, increased proliferation and angiogenesis contributes to the increased immunosuppresion and mediates carcinogenetic effects. MicroRNAs are regarded as a novel class of gene expression regulators. They are gene-silencing RNAs which negatively regulate gene expression. After binding to target mRNAs they lead either to mRNA destruction or inhibition of translation. Hence, they can play an important role in carcinogenesis. Currently, almost all of the miRNA-related studies on cancers based on the different expression profile of miRNAs in cancer cells compared to normal cells. In summary, miRNAs, proinflammatory cytokines and other factors, may be involved in cancer development based on chronic inflammation by controlling cell differentiation and apoptosis. Assessing the role of miRNAs will provide the new insights on their contribution to the link between chronic inflammation and subsequent cancer, and new markers for cancer diagnoses and cancer therapy

    Inhibitory effect of selenomethionine on carcinogenesis in the model of human colorectal cancer in vitro and its link to the Wnt/β-catenin pathway

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    Selenium compounds have been implicated as anticancer agents; however, the mechanism of their inhibitory action against cancer development has not been extensively investigated. A constitutive activation of the Wnt/β-catenin pathway is a central event in colorectal carcinogenesis. In this pathway, excessive cell proliferation is initiated by generation of β-catenin followed by overexpression of proto-oncogenes, such as c-Myc. It is believed that under physiological conditions the level of c-Myc is efficiently controlled by accessibility of the β-catenin protein through the process of phosphorylation by glycogen synthase kinase 3β (GSK-3β). Here, we determined whether selenomethionine (SeMet) can inhibit cell growth and affect the Wnt/β-catenin pathway in the HT-29 human colorectal cancer cells in vitro. The effective cytotoxic doses of SeMet have been selected after 48 h of incubation of this compound with colorectal cancer HT-29 cell line. MTT assay was used to assess cell viability and the protein and mRNA levels of β-catenin and c-Myc were determined by Western blotting and qPCR, respectively. SeMet potently inhibited growth of HT-29 cells, significantly decreased level of the β-catenin protein and mRNA concentration, down-regulated the c-Myc gene expression and up-regulated the pro-apoptotic Bax protein level. Moreover, SeMet increased the level of GSK-3β phosphorylated at serine 9 (S9) and significantly increased the level of β-catenin phosphorylated at S33 and S37. We conclude that SeMet suppresses growth of HT-29 colorectal cancer cells by a mechanism linked to the Wnt/β-catenin pathway, however, degradation of β-catenin may occur independently of GSK-3β catalytic activity and its phosphorylation status

    Non-destructive study of non-equilibrium states of cold, trapped atoms

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    Highly sensitive, non-destructive, real-time spectroscopic determination of the 2D kinetic momentum distribution of a cold-atom sample is performed with the three-beam measurement of the recoil-induced resonances. The measurements performed with an operating magneto-optical trap reveal slow velocity drifts within a stationary atomic cloud and strong anisotropy and asymmetry of the non-Maxwellian momentum distribution. The developed method can be easily extended to 3D.Comment: 4 pages, 5 figures, submitted to PR
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