Engine Hydraulic Stability

An analytical injector model was developed specifically to analyze combustion instability coupling between the injector hydraulics and the combustion process. This digital computer dynamic injector model will, for any imposed chamber of inlet pressure profile with a frequency ranging from 100 to 3000 Hz (minimum) accurately predict/calculate the instantaneous injector flowrates. The injector system is described in terms of which flow segments enter and leave each pressure node. For each flow segment, a resistance, line lengths, and areas are required as inputs (the line lengths and areas are used in determining inertance). For each pressure node, volume and acoustic velocity are required as inputs (volume and acoustic velocity determine capacitance). The geometric criteria for determining inertances of flow segments and capacitance of pressure nodes was set. Also, a technique was developed for analytically determining time averaged steady-state pressure drops and flowrates for every flow segment in an injector when such data is not known. These pressure drops and flowrates are then used in determining the linearized flow resistance for each line segment of flow

Interleukin 21 controls tumour growth and tumour immunosurveillance in colitis-associated tumorigenesis in mice

Background and aims: Colitis-associated tumorigenesis is a balance between proliferation of tumour cells and tumour immunosurveillance. The role of T-helper-cell-derived cytokines in tumour growth is not fully understood. In this study the authors investigated the influence of interleukin (IL) 21 on intestinal tumorigenesis. Methods: Chronic colitis was induced in IL-21−/− and littermate control wild-type mice with three cycles of 1.5% dextran sulphate sodium (DSS) over 7 days followed by 7 days of drinking water. Mice received an azoxymethane injection on day 0 of DSS-colitis to induce tumorigenesis. Immunohistochemistry was performed on inflamed and tumour-bearing areas of colons. Cytokine expression of isolated colonic CD4 T cells was determined by ELISA. Cytotoxic capacity of isolated colonic CD8 T cells targeting tumour cells was evaluated by flow cytometry and quantitative cytotoxicity assay. Apoptosis of tumour cells was determined by TUNEL assay of colonic sections. Results: Increasing expression of IL-21 was observed in chronic colitis, which showed functional importance, since IL-21 deficiency prevented chronic DSS-colitis development. Further, in the absence of IL-21, significantly fewer tumour nodules were detected, despite a similar extent of intestinal inflammation. In wild-type mice, 8.6±1.9 tumour nodules were found compared with 1.0±1.2 in IL-21-deficient mice. In tumour-bearing IL-21-deficient mice, intestinal inflammation was restored and partly dependent on interferon (IFN)-γ, whereas the inflammation in wild-type mice showed high IL-17A concentrations. In these rare tumours in IL-21-deficient mice, tumour cell proliferation (Ki-67) was decreased, while cell apoptosis was increased, compared with wild-type mice. Increased IFNγ expression in tumour-bearing IL-21-deficient mice led to increased tumour immunosurveillance mediated by cytotoxic CD8CD103 T cells targeting E-cadherin+ colonic tumour cells and therefore limited tumour growth. Conclusion: These results indicate that IL-21 orchestrates colitis-associated tumorigenesis, leading to the hypothesis that high IFNγ and low IL-17A expression reduces tumour cell proliferation and increases tumour immunosurveillance

The Real-World Experiences of Persons With Multiple Sclerosis During the First COVID-19 Lockdown: Application of Natural Language Processing.

The increasing availability of "real-world" data in the form of written text holds promise for deepening our understanding of societal and health-related challenges. Textual data constitute a rich source of information, allowing the capture of lived experiences through a broad range of different sources of information (eg, content and emotional tone). Interviews are the "gold standard" for gaining qualitative insights into individual experiences and perspectives. However, conducting interviews on a large scale is not always feasible, and standardized quantitative assessment suitable for large-scale application may miss important information. Surveys that include open-text assessments can combine the advantages of both methods and are well suited for the application of natural language processing (NLP) methods. While innovations in NLP have made large-scale text analysis more accessible, the analysis of real-world textual data is still complex and requires several consecutive steps. We developed and subsequently examined the utility and scientific value of an NLP pipeline for extracting real-world experiences from textual data to provide guidance for applied researchers. We applied the NLP pipeline to large-scale textual data collected by the Swiss Multiple Sclerosis (MS) registry. Such textual data constitute an ideal use case for the study of real-world text data. Specifically, we examined 639 text reports on the experienced impact of the first COVID-19 lockdown from the perspectives of persons with MS. The pipeline has been implemented in Python and complemented by analyses of the "Linguistic Inquiry and Word Count" software. It consists of the following 5 interconnected analysis steps: (1) text preprocessing; (2) sentiment analysis; (3) descriptive text analysis; (4) unsupervised learning-topic modeling; and (5) results interpretation and validation. A topic modeling analysis identified the following 4 distinct groups based on the topics participants were mainly concerned with: "contacts/communication;" "social environment;" "work;" and "errands/daily routines." Notably, the sentiment analysis revealed that the "contacts/communication" group was characterized by a pronounced negative emotional tone underlying the text reports. This observed heterogeneity in emotional tonality underlying the reported experiences of the first COVID-19-related lockdown is likely to reflect differences in emotional burden, individual circumstances, and ways of coping with the pandemic, which is in line with previous research on this matter. This study illustrates the timely and efficient applicability of an NLP pipeline and thereby serves as a precedent for applied researchers. Our study thereby contributes to both the dissemination of NLP techniques in applied health sciences and the identification of previously unknown experiences and burdens of persons with MS during the pandemic, which may be relevant for future treatment

Tourism as connectedness.

Late modernity in developed nations is characterized by changing social and psychological conditions, including individualization, processes of competition and loneliness. Remaining socially connected is becoming increasingly important. In this situation, travel provides meaning through physical encounters, inclusion in traveller Gemeinschaft based on shared norms, beliefs and interests, and social status in societies increasingly defined by mobilities. As relationships are forged and found in mobility, travel is no longer an option, rather a necessity for sociality, identity construction, affirmation or alteration. Social contexts and the underlying motivations for tourism have changed fundamentally in late modernity: non-tourism has become a threat to self-conceptions. By integrating social and psychological perspectives, this paper expands and deepens existing travel and mobilities discussions to advance the understanding of tourism as a mechanism of social connectedness, and points to implications for future tourism research

Cross‐presentation of dead‐cell‐associated antigens by DNGR‐1⁺ dendritic cells contributes to chronic allograft rejection in mice

The purpose of this study was to elucidate whether DC NK lectin group receptor-1 (DNGR-1)-dependent cross-presentation of dead-cell-associated antigens occurs after transplantation and contributes to CD8(+)T cell responses, chronic allograft rejection (CAR), and fibrosis. BALB/c or C57BL/6 hearts were heterotopically transplanted into WT, Clec9a(-/-), or Batf3(-/-)recipient C57BL/6 mice. Allografts were analyzed for cell infiltration, CD8(+)T cell activation, fibrogenesis, and CAR using immunohistochemistry, Western blot, qRT(2)-PCR, and flow cytometry. Allografts displayed infiltration by recipient DNGR-1(+)DCs, signs of CAR, and fibrosis. Allografts in Clec9a(-/-)recipients showed reduced CAR (p < 0.0001), fibrosis (P= 0.0137), CD8(+)cell infiltration (P < 0.0001), and effector cytokine levels compared to WT recipients. Batf3-deficiency greatly reduced DNGR-1(+)DC-infiltration, CAR (P < 0.0001), and fibrosis (P= 0.0382). CD8 cells infiltrating allografts of cytochrome C treated recipients, showed reduced production of CD8 effector cytokines (P < 0.05). Further, alloreactive CD8(+)T cell response in indirect pathway IFN-gamma ELISPOT was reduced in Clec9a(-/-)recipient mice (P= 0.0283). Blockade of DNGR-1 by antibody, similar to genetic elimination of the receptor, reduced CAR (P= 0.0003), fibrosis (P= 0.0273), infiltration of CD8(+)cells (p= 0.0006), and effector cytokine levels. DNGR-1-dependent alloantigen cross-presentation by DNGR-1(+)DCs induces alloreactive CD8(+)cells that induce CAR and fibrosis. Antibody against DNGR-1 can block this process and prevent CAR and fibrosis

Transcultural Brokerage: The Role of Cosmopolitans in Bridging Structural and Cultural Holes

The growth and proliferation of global systems and transnational cultures have generated larger and more diverse types of cosmopolitans, all of whom span conventional social boundaries. Understanding this diversity is increasingly important because cosmopolitans often bridge across a wide range of transnational and global networks within and across global organizations. Drawing on multiple disciplines, we conceptualize cosmopolitanism as an embodied disposition characterized by high levels of cultural transcendence and openness that are manifested in and enacted along varied trajectories of cultural embeddedness in one’s own culture and cultural engagement with the cultural Other. We then propose an analytical framework for the influence of cosmopolitan disposition on transcultural brokerage processes, specifically on bridging structural and cultural holes. Finally, we present a typology of cosmopolitan brokers and their corresponding practices and activities as they engage in transcultural brokerage. By recognizing the diversity of cosmopolitans and their respective dispositions, we significantly expand the pool of “global talent” beyond the traditional focus on expatriates, and we challenge the conventional wisdom on who counts as talent in an interconnected world