262 research outputs found

    Dynamic utilisation of knowledge in decision making

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    The contribution of this research is a set of novel insights on the interplay of knowledge assets during decision making. Knowledge is conceptualised as a dynamic resource. Its value is a function of the contribution it makes relative to other knowledge stock at a point of application. The information flows can renew the resource, and the influence of power makes the knowledge development process subject to reconciliation of local interests. The focus on dynamics of knowledge development through a set of value-adding processes also moves the analysis away from the rational and political perspectives of knowledge in decision making. This offers an alternative view on how the value of knowledge can be assessed and understood. The research proposes how the decision making process could be a useful mechanism for the development of dynamic capabilities. The findings stem from the view of knowledge developed in this research as a knowledge capsule comprised of two or three knowledge assets which can draw upon two other types of knowledge from outside the decision process. The analysis relies on two in-depth strategic decision case studies and suggests that the value of knowledge can be identified from the point at which the central decision is generated. The value of each interplay can be assessed in a 'transactional' space where three types of knowledge 'meet'. Decision making is a knowledge-creating activity. The interplay of knowledge assets is a source of value in decision making and, this thesis argues, the basis of heterogeneity of this strategic asset between organisations. Power impacts the contribution of knowledge assets and through application is redistributed during the decision making process. As knowledge stocks interplay, some knowledge is attuning and some advancing the work in decision episodes. The value can be identified by assessing the outcomes of interplay such as insights and decisions. The managerial implications focus on the challenges for developing knowledge assets and the extraction of value from existing knowledge assets during strategic decision making

    Erythematodes chronicus profundus as dermatology, surgery and cosmetology problem

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    Lupus profundus is a rare skin condition originally described by Kaposi in 1883. It is a clinical variant of LE in which the deep dermis and subcutaneous fat are predominantly affected. A 38-year-old female presented with history of development of well-circumscribed patches of hair loss since 1994 year. In 2004 on the skin of left cheek she noticed a single erythematous plaque on which place later became dint of subcutaneous tissue. Today she has massive defects across whole scalp, right cheek and the upper part of left arm with multiple ulcers(fig.3and4). case reposrt, laboratory examinations, skin biopsy and influence of corticosteroids on further progression /regression of this disease

    Genomic profiling of T-cell activation suggests increased sensitivity of memory T cells to CD28 costimulation

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    T-cell activation is a critical driver of immune responses. The CD28 costimulation is an essential regulator of CD4 T-cell responses, however, its relative importance in naive and memory T cells is not fully understood. Using different model systems, we observe that human memory T cells are more sensitive to CD28 costimulation than naive T cells. To deconvolute how the T-cell receptor (TCR) and CD28 orchestrate activation of human T cells, we stimulate cells using varying intensities of TCR and CD28 and profiled gene expression. We show that genes involved in cell cycle progression and division are CD28-driven in memory cells, but under TCR control in naive cells. We further demonstrate that T-helper differentiation and cytokine expression are controlled by CD28. Using chromatin accessibility profiling, we observe that AP1 transcriptional regulation is enriched when both TCR and CD28 are engaged, whereas open chromatin near CD28- sensitive genes is enriched for NF-kB motifs. Lastly, we show that CD28-sensitive genes are enriched in GWAS regions associated with immune diseases, implicating a role for CD28 in disease development. Our study provides important insights into the differential role of costimulation in naive and memory T-cell responses and disease susceptibility

    Salivary levels of tumor necrosis factor-alpha in oral lichen planus.

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    OBJECTIVE: Oral lichen planus (OLP) is chronic inflammatory disease of the oral mucosa, presenting in various clinical forms. The etiology of OLP is still unknown but mounting evidence points to the immunologic basis of this disorder. AIM: Our study was undertaken to quantify the salivary levels of pro-inflammatory tumor necrosis factor-alpha (TNF-alpha) in the reticular and the erosive/atrophic forms of OLP, compared with age-matched healthy control volunteers. SUBJECTS AND METHODS: Whole saliva from 40 patients with active lesions of OLP, as well as from 20 healthy persons, was investigated for the presence of TNF-alpha by enzyme immunoassay. RESULTS: Salivary TNF-alpha levels were significantly increased in patients with OLP in comparison with healthy subjects. The presence of TNF-alpha showed positive correlation to clinical forms of OLP, being significantly higher in the erosive/atrophic type than in the reticular type of disease. CONCLUSION: Saliva provides an ideal medium for the detection of pro-inflammatory markers of the oral cavity. In patients with OLP, TNF-alpha levels in saliva are elevated, correlating with the severity of illness. Salivary TNF-alpha analysis may be a useful diagnostic tool and a potential prognostic marker in OLP

    Effect of the Position in the Build Chamber on the Fatigue Strength of Additively Manufactured Maraging Steel MS1

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    The quality of additively produced parts and the achievable mechanical response may be affected by several factors, such as build orientation, heat treatment, or machining. A further rarely investigated factor is the position of the built part in the chamber with respect to inert gas flow. Previous studies have highlighted that the interaction between gas flow and laser track may induce an intense vaporization with consequent lack of fusion, particle entrainment, drop in density and denudation of the produced part, which is likely to detrimentally affect mechanical properties. This study addresses the effect of part position on the fatigue strength of heat-treated maraging steel MS1 produced by an EOSINT M280 machine in a nitrogen environment. Novelty arises from the lack of studies in this field, especially under fatigue. A factorial plan with subsequent statistical analysis highlighted that positioning the part upstream with respect to the gas flow leads to a slightly lower fatigue strength; however, no significant differences are observed. The failure mode, involving initiation from subsurface porosities of the same size, is also unaffected. Finally, a fatigue limit of 26% of the ultimate tensile strength is found, which is consistent with previous outcomes

    Fatigue response of additively manufactured as-built 15-5 PH stainless steel and effects of machining and thermal and surface treatments

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    Additively produced 15-5 PH stainless steel has wide industrial applications, but the combined effects of heat treatment, machining, and shot-peening and their order have not been deeply investigated. This topic is addressed here by a 2-by-3 experimental plan that has involved S–N curve and fatigue limit determination, using vertically built cylindrical samples, tested under rotating bending. The obtained responses have been analyzed by an ANOVA-based statistical approach for comparison of fatigue trends. Results indicate that heat treatment without machining may be even detrimental for fatigue due to embrittlement. Conversely, machining with subsequent shot-peening, even without heat treatment, has a remarkable impact and leads to a doubled fatigue strength with respect to as-built material. This strength is also quite close to that achievable for wrought material. The study has been completed by micrography and fractography, to reveal the dependence of microstructure, crack initiation sites, and failure mode on the performed treatments

    Analysis of Photothermal Response of Thin Solid Films By Analogy with Passive Linear Electric Networks

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    The paper presents conditions that should be met in order to make the photothermal induced temperature variations of a solid sample analogous to the voltage variations of the electric network with passive linear elements. Further analysis shows that such analogy enhances experimental determination of the thermal properties of thin solid layers by photothermal frequency metho

    Fatigue response of additively manufactured Maraging Stainless Steel CX and effects of heat treatment and surface finishing

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    This paper deals with the novel topic of the fatigue response of additively manufactured Maraging Stainless Steel CX. A two-by-two factorial plan was arranged, to experimentally assess the effects of heat treatment and machining on the fatigue strength in both finite and infinite life domains. The two factors were regarded as on–off, taking the untreated unmachined condition as a reference for comparisons. Cylindrical specimens with vertical build orientation were involved in the fatigue campaign under four-point rotating bending. The results indicate that the fatigue strength may be remarkably incremented (up to five times) with respect to the as received conditions, especially thanks to surface smoothing and taking advantage of a very low porosity level. Heat treatment strengthening mechanisms were also interpreted in the light of optical and electron microscope observations. Fatigue enhancement arises from precipitate size increment throughout the conducted heat treatment, although the fracture mode turns to be more brittle

    CD80 on Human T Cells Is Associated With FoxP3 Expression and Supports Treg Homeostasis

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    CD80 and CD86 are expressed on antigen presenting cells (APCs) and their role in providing costimulation to T cells is well established. However, it has been shown that these molecules can also be expressed by T cells, but the significance of this observation remains unknown. We have investigated stimuli that control CD80 and CD86 expression on T cells and show that in APC-free conditions around 40% of activated, proliferating CD4+ T cells express either CD80, CD86 or both. Expression of CD80 and CD86 was strongly dependent upon provision of CD28 costimulation as ligands were not expressed following TCR stimulation alone. Furthermore, we observed that CD80+ T cells possessed the hallmarks of induced regulatory T cells (iTreg), expressing Foxp3 and high levels of CTLA-4 whilst proliferating less extensively. In contrast, CD86 was preferentially expressed on INF-γ producing cells, which proliferated more extensively and had characteristics of effector T cells. Finally, we demonstrated that CD80 expressed on T cells inhibits CTLA-4 function and facilitates the growth of iTreg. Together these data establish endogenous expression of CD80 and CD86 by activated T cells is not due to ligand capture by transendocytosis and highlight clear differences in their expression patterns and associated functions
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