474 research outputs found

    Factors influencing the entrepreneurial engagement of opportunity and necessity entrepreneurs

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    The scholarly literature often distinguishes between so-called opportunity and necessity entrepreneurship and between “pull” and “push” motivations. Despite the pervasive use of this terminology, empirical analyses are mostly based on a single country. The present paper contribut

    Human Dendritic Cell Subsets Undergo Distinct Metabolic Reprogramming for Immune Response

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    Toll-like receptor (TLR) agonists induce metabolic reprogramming, which is required for immune activation. We have investigated mechanisms that regulate metabolic adaptation upon TLR-stimulation in human blood DC subsets, CD1c+ myeloid DCs (mDCs) and plasmacytoid DCs (pDCs). We show that TLR-stimulation changes expression of genes regulating oxidative phosphorylation (OXPHOS) and glutamine metabolism in pDC. TLR-stimulation increases mitochondrial content and intracellular glutamine in an autophagy-dependent manner in pDC. TLR-induced glutaminolysis fuels OXPHOS in pDCs. Notably, inhibition of glutaminolysis and OXPHOS prevents pDC activation. Conversely, TLR-stimulation reduces mitochondrial content, OXPHOS activity and induces glycolysis in CD1c+ mDC. Inhibition of mitochondrial fragmentation or promotion of mitochondrial fusion impairs TLR-stimulation induced glycolysis and activation of CD1c+ mDCs. TLR-stimulation triggers BNIP3-dependent mitophagy, which regulates transcriptional activity of AMPKα1. BNIP3-dependent mitophagy is required for induction of glycolysis and activation of CD1c+ mDCs. Our findings reveal that TLR stimulation differentially regulates mitochondrial dynamics in distinct human DC subsets, which contributes to their activation

    Entrepreneurship and Role Models

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    In the media role models are increasingly being acknowledged as an influential factor in explaining the reasons for the choice of occupation and career. Various conceptual studies have proposed links between role models and entrepreneurial intentions. However, empirical research aimed at establishing the importance of role models for (nascent) entrepreneurs is scarce. Knowledge of the presence of entrepreneurial role models, their specific functions and characteristics is therefore limited. Our explorative empirical study is a first step towards filling this gap. Our study is based on the outcomes of a questionnaire completed by a representative sample of 292 entrepreneurs in three major Dutch cities - entrepreneurs who have recently started up a business in the retail, hotel and restaurant sectors, business services and other services. We provide indications of the presence and importance of entrepreneurial role models, the function of these role models, the similarity between the entrepreneur and the role model, and the strength of their relationship

    Overcoming alcohol and other drug addiction as a process of social identity transition : the social identity model of recovery (SIMOR)

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    In recent years, there has been an increasing focus on a recovery model within alcohol and drug policy and practice. This has occurred concurrently with the emergence of community- and strengths-based approaches in positive psychology, mental health recovery and desistance and rehabilitation from offending. Recovery is predicated on the idea of substance user empowerment and self-determination, using the metaphor of a ‘‘journey’’. Previous research describing recovery journeys has pointed to the importance of identity change processes, through which the internalised stigma and status of an ‘‘addict identity’’ is supplanted with a new identity. This theoretical paper argues that recovery is best understood as a personal journey of socially negotiated identity transition that occurs through changes in social networks and related meaningful activities. Alcoholics Anonymous (AA) is used as a case study to illustrate this process of social identity transition. In line with recent social identity theorising, it is proposed that (a) identity change in recovery is socially negotiated, (b) recovery emerges through socially mediated processes of social learning and social control and (c) recovery can be transmitted in social networks through a process of social influence

    Interobserver and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography

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    BACKGROUND: Data regarding the inter- and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography are missing in the current literature. This study assessed the inter- and intraobserver variability in the radiological assessment of sialolithiasis using cone beam computed tomography (CBCT). MATERIAL AND METHODS: In 107 patients, 130 salivary glands (65 parotid and 65 submandibular) with clinical signs of obstruction were assessed by four independent observers; 2 residents OMFS and 2 experienced OMFS. The observers analyzed the CBCT images and determined the absence or presence of one or more salivary stones in the affected gland. This procedure was repeated after three months. RESULTS: Interobserver agreements showed kappa values of 0.84 for the parotid gland, and 0.93 for the submandibular gland. Intraobserver agreements for the whole group reported kappa values between 0.83 - 0.95. There was no significant difference between residents and experienced OMFS. CONCLUSIONS: Due to the good inter- and intraobserver agreement, CBCT appears to be a reproducible imaging modality for detecting salivary stones in patients with signs and symptoms of obstructed parotid and submandibular glands. Key words:Salivary gland calculi, cone-beam computed tomography, observer variation

    The use of stretching devices for treatment of trismus in head and neck cancer patients:a randomized controlled trial

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    PURPOSE: To compare the effects of two stretching devices, the TheraBite® Jaw Motion Rehabilitation System™ and the Dynasplint Trismus System®, on maximal mouth opening in head and neck cancer patients. METHODS: Patients were randomly assigned to one of two exercise groups: the TheraBite® Jaw Motion Rehabilitation System™ group or the Dynasplint Trismus System® group. Patients performed stretching exercises for 3 months. During the three study visits, maximal mouth opening was measured and the patients completed questionnaires on mandibular function and quality of life. RESULTS: In our study population (n = 27), five patients did not start the exercise protocol, eight patients discontinued exercises, and two patients were lost to follow-up. No significant differences regarding the change in mouth opening between the two devices were found. Patients had an increase in MMO of 3.0 mm (IQR - 2.0; 4.0) using the TheraBite® Jaw Motion Rehabilitation System™ and 1.5 mm (IQR 1.0; 3.0) using the Dynasplint Trismus System®. Exercising with either stretching device was challenging for the patients due to the intensive exercise protocol, pain during the exercises, fitting problems with the stretching device, and overall deterioration of their medical condition. CONCLUSIONS: The effects of the two stretching devices did not differ significantly in our study population. The factors described, influencing the progression of stretching exercises, need to be taken into account when prescribing a similar stretching regimen for trismus in head and neck cancer patients. TRIAL REGISTRATION: NTR - Dutch Trial Register number: 5589

    Analisis Peramalan Nilai Tukar Petani di Provinsi Jawa Barat

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    Farmer’s term of trade is a comparison between the price index paid by farmers and the price index paid by farmers, expressed as a percentage and used as an indicator to measure the level of farmer welfare. West Java has fluctuating Farmer’s term of trade of food crops, horticultural crops, and community plantations. This study aims to determine the best forecasting method and forecast Farmer’s term of trade of food crops, horticultural crops, and community plantations in West Java for the next 60 months. The research method used is descriptive analysis with a quantitative approach. This study uses secondary data in the form of time series from 2013-2021 totaling 108 periods sourced from the Statistics Indonesia and the Ministry of Agriculture. Data is processed using Minitab 20 application and Microsoft Excel. The data analysis techniques used are linear trend forecasting, quadratic trend, and exponential trend. Based on the smallest MAPE, MAD, and MSD values, the best method of forecasting Farmer’s term of trade of food crop and horticultural crops is a quadratic trend, while forecasting Farmer’s term of trade of smallholder plantation farmers is a linear trend. The forecasting of Farmer’s term of trade of food crop farmers has the equation model  = 101.25 + 0.0737X - 0.000964X2, horticultural crops have the equation model   = 105.28 + 0.1042X - 0.001561X2 , and smallholder plantation crops have the equation model   = 100.156 - 0.04342X. The results of forecasting Farmer’s term of trade of food crops, horticultural crops, and community plantations each have an average value of 92.6753%; 89.3132% and 94.14342%

    Chikungunya virus requires an intact microtubule network for efficient viral genome delivery

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    Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus, which has rapidly spread around the globe thereby causing millions of infections. CHIKV is an enveloped virus belonging to the Togaviridae family and enters its host cell primarily via clathrin-mediated endocytosis. Upon internalization, the endocytic vesicle containing the virus particle moves through the cell and delivers the virus to early endosomes where membrane fusion is observed. Thereafter, the nucleocapsid dissociates and the viral RNA is translated into proteins. In this study, we examined the importance of the microtubule network during the early steps of infection and dissected the intracellular trafficking behavior of CHIKV particles during cell entry. We observed two distinct CHIKV intracellular trafficking patterns prior to membrane hemifusion. Whereas half of the CHIKV virions remained static during cell entry and fused in the cell periphery, the other half showed fast-directed microtubule-dependent movement prior to delivery to Rab5-positive early endosomes and predominantly fused in the perinuclear region of the cell. Disruption of the microtubule network reduced the number of infected cells. At these conditions, membrane hemifusion activity was not affected yet fusion was restricted to the cell periphery. Furthermore, follow-up experiments revealed that disruption of the microtubule network impairs the delivery of the viral genome to the cell cytosol. We therefore hypothesize that microtubules may direct the particle to a cellular location that is beneficial for establishing infection or aids in nucleocapsid uncoating

    Criterion for trismus in head and neck cancer patients:a verification study

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    Several cut-off points for trismus in head and neck cancer patients have been used. A mouth opening of 35 mm or less is most frequently used as cut-off point. Due to the variation in cut-off points, prevalence, risk factors and treatment outcomes of trismus cannot be studied in a uniform manner. To provide uniformity, we aimed to verify the cut-off point of 35 mm or less. Additionally, we aimed to determine associated covariates with reported difficulties when opening the mouth

    Plasmacytoid dendritic cells of melanoma patients present exogenous proteins to CD4+ T cells after FcγRII-mediated uptake

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    Plasmacytoid dendritic cells (pDCs) contribute to innate antiviral immune responses by producing type I interferons. Although human pDCs can induce T cell responses upon viral infection, it remains unclear if pDCs can present exogenous antigens. Here, we show that human pDCs exploit FcγRII (CD32) to internalize antigen–antibody complexes, resulting in the presentation of exogenous antigen to T cells. pDCs isolated from melanoma patients vaccinated with autologous monocyte-derived peptide- and keyhold limpet hemocyanin (KLH)–loaded dendritic cells, but not from nonvaccinated patients or patients that lack a humoral response against KLH, were able to stimulate KLH-specific T cell proliferation. Interestingly, we observed that internalization of KLH by pDCs depended on the presence of serum from vaccinated patients that developed an anti-KLH antibody response. Anti-CD32 antibodies inhibited antigen uptake and presentation, demonstrating that circulating anti-KLH antibodies binding to CD32 mediate KLH internalization. We conclude that CD32 is an antigen uptake receptor on pDCs and that antigen presentation by pDCs is of particular relevance when circulating antibodies are present. Antigen presentation by pDCs may thus modulate the strength and quality of the secondary phase of an immune response
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