Comparative naval architecture analysis of diesel submarines

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 2005.Includes bibliographical references (leaf 59).Many comparative naval architecture analyses of surface ships have been performed, but few published comparative analyses of submarines exist. Of the several design concept papers, reports and studies that have been written on submarines, no exclusively diesel submarine comparative naval architecture analyses have been published. One possible reason for few submarine studies may be the lack of complete and accurate information regarding the naval architecture of foreign diesel submarines. However, with some fundamental submarine design principles, drawings of inboard profiles and plan views, and key assumptions to develop empirical equations, a process can be developed by which to estimate the submarine naval architectural characteristics. comparative naval architecture analysis creates an opportunity to identify new technologies, review the architectural characteristics best suited for submarine missions and to possibly build more effective submarines. An accurate observation is that submarines designed for different missions possess different capabilities. But are these unique capabilities due to differences in submarine naval architecture? Can mission, cost, or other factors affect the architecture?(cont.) This study examines and compares the naval architecture of selected diesel submarines from data found in open literature. The goal is to determine weight group estimates and analyze whether these estimates provide a relevant comparison of diesel submarine naval architecture.by Kai Oscar Torkelson.S.M

The Leap into the New Normal in Creative Work: A Qualitative Study of the Impact of COVID-19 on Work Practices in Industrial Companies

For many employees, the COVID-19 pandemic has precipitated a move from centralized workplaces to full-time teleworking from home. As a catalyst for the virtualization of the working world, the pandemic has accelerated company transformation to digitalization and New Work. In a post-COVID-19 world, companies will face the challenge of combining virtual and physical working while offering employees an appropriate working infrastructure. However, the future consequences for work design remain unclear, as many companies are in a state of flux. The purpose of the present study was to develop an up-to-date overview of what this future New Normal might look like, and to expand existing knowledge in this regard. To that end, we conducted fifteen in-depth interviews with experts from German industrial companies. The findings identify four main areas of change at individual and team levels: the meaning of the work environment, collaboration, creative work, and the nature of future work. The results offer some profound insights into the field of design and virtualization in terms of working location, working time models, and the future of collaborative and creative work. The paper concludes with recommendations for practice and future research. Keywords: New Work, COVID-19, Physical Work Environment, Collaboration, Creativity, Digital Trans-formation, New Normal DOI: 10.7176/EJBM/13-10-01 Publication date:May 31st 202

Clearance of Asymptomatic P. falciparum Infections Interacts with the Number of Clones to Predict the Risk of Subsequent Malaria in Kenyan Children

BACKGROUND: Protective immunity to malaria is acquired after repeated infections in endemic areas. Asymptomatic multiclonal P. falciparum infections are common and may predict host protection. Here, we have investigated the effect of clearing asymptomatic infections on the risk of clinical malaria. METHODS: Malaria episodes were continuously monitored in 405 children (1-6 years) in an area of moderate transmission, coastal Kenya. Blood samples collected on four occasions were assessed by genotyping the polymorphic P. falciparum merozoite surface protein 2 using fluorescent PCR and capillary electrophoresis. Following the second survey, asymptomatic infections were cleared with a full course of dihydroartemisinin. RESULTS: Children who were parasite negative by PCR had a lower risk of subsequent malaria regardless of whether treatment had been given. Children with ≥ 2 clones had a reduced risk of febrile malaria compared with 1 clone after clearance of asymptomatic infections, but not if asymptomatic infections were not cleared. Multiclonal infection was associated with an increased risk of re-infection after drug treatment. However, among the children who were re-infected, multiclonal infections were associated with a shift from clinical malaria to asymptomatic parasitaemia. CONCLUSION: The number of clones was associated with exposure as well as blood stage immunity. These effects were distinguished by clearing asymptomatic infection with anti-malarials. Exposure to multiple P. falciparum infections is associated with protective immunity, but there appears to be an additional effect in untreated multiclonal infections that offsets this protective effect

Transcriptome-Wide Mapping of Pea Seed Ageing Reveals a Pivotal Role for Genes Related to Oxidative Stress and Programmed Cell Death

Understanding of seed ageing, which leads to viability loss during storage, is vital for ex situ plant conservation and agriculture alike. Yet the potential for regulation at the transcriptional level has not been fully investigated. Here, we studied the relationship between seed viability, gene expression and glutathione redox status during artificial ageing of pea (Pisum sativum) seeds. Transcriptome-wide analysis using microarrays was complemented with qRT-PCR analysis of selected genes and a multilevel analysis of the antioxidant glutathione. Partial degradation of DNA and RNA occurred from the onset of artificial ageing at 60% RH and 50 degrees C, and transcriptome profiling showed that the expression of genes associated with programmed cell death, oxidative stress and protein ubiquitination were altered prior to any sign of viability loss. After 25 days of ageing viability started to decline in conjunction with progressively oxidising cellular conditions, as indicated by a shift of the glutathione redox state towards more positive values (>-190 mV). The unravelling of the molecular basis of seed ageing revealed that transcriptome reprogramming is a key component of the ageing process, which influences the progression of programmed cell death and decline in antioxidant capacity that ultimately lead to seed viability loss.Spanish Ministerio de Educacion y CienciaJunta de Castilla y Leon/BIO2011-26940Junta de Castilla y Leon/CSD2007-00057Junta de Castilla y Leon/SA048A10-2DFG/Le720/7Chinese Academy of Sciences/KSCX2-EW-J-24Chinese Academy of Sciences/Y3221411W1Millenium CommissionWellcome TrustOrange PlcDefr

Quantitative PCR Evaluation of Cellular Immune Responses in Kenyan Children Vaccinated with a Candidate Malaria Vaccine

BACKGROUND: The T-cell mediated immune response plays a central role in the control of malaria after natural infection or vaccination. There is increasing evidence that T-cell responses are heterogeneous and that both the quality of the immune response and the balance between pro-inflammatory and regulatory T-cells determines the outcome of an infection. As Malaria parasites have been shown to induce immunosuppressive responses to the parasite and non-related antigens this study examined T-cell mediated pro-inflammatory and regulatory immune responses induced by malaria vaccination in children in an endemic area to determine if these responses were associated with vaccine immunogenicity. METHODS: Using real-time RT- PCR we profiled the expression of a panel of key markers of immunogenecity at different time points after vaccination with two viral vector vaccines expressing the malaria TRAP antigen (FP9-TRAP and MVA-TRAP) or following rabies vaccination as a control. PRINCIPAL FINDINGS: The vaccine induced modest levels of IFN-gamma mRNA one week after vaccination. There was also an increase in FoxP3 mRNA expression in both TRAP stimulated and media stimulated cells in the FFM ME-TRAP vaccine group; however, this may have been driven by natural exposure to parasite rather than by vaccination. CONCLUSION: Quantitative PCR is a useful method for evaluating vaccine induced cell mediated immune responses in frozen PBMC from children in a malaria endemic country. Future studies should seek to use vaccine vectors that increase the magnitude and quality of the IFN-gamma immune response in naturally exposed populations and should monitor the induction of a regulatory T cell response

Lactate levels in severe malarial anaemia are associated with haemozoin-containing neutrophils and low levels of IL-12

BACKGROUND: Hyperlactataemia is often associated with a poor outcome in severe malaria in African children. To unravel the complex pathophysiology of this condition the relationship between plasma lactate levels, parasite density, pro- and anti-inflammatory cytokines, and haemozoin-containing leucocytes was studied in children with severe falciparum malarial anaemia. METHODS: Twenty-six children with a primary diagnosis of severe malarial anaemia with any asexual Plasmodium falciparum parasite density and Hb < 5 g/dL were studied and the association of plasma lactate levels and haemozoin-containing leucocytes, parasite density, pro- and anti-inflammatory cytokines was measured. The same associations were measured in non-severe malaria controls (N = 60). RESULTS: Parasite density was associated with lactate levels on admission (r = 0.56, P < 0.005). Moreover, haemozoin-containing neutrophils and IL-12 were strongly associated with plasma lactate levels, independently of parasite density (r = 0.60, P = 0.003 and r = -0.46, P = 0.02, respectively). These associations were not found in controls with uncomplicated malarial anaemia. CONCLUSION: These data suggest that blood stage parasites, haemozoin and low levels of IL-12 may be associated with the development of hyperlactataemia in severe malarial anaemia

Functional characterization and differential nutritional regulation of putative Elovl5 and Elovl4 elongases in large yellow croaker (Larimichthys crocea)

In the present study, two elongases, Elovl4 and Elovl5, were functionally characterized and their transcriptional regulation in response to n-3 LC-PUFA administration were investigated in vivo and in vitro. We previously described the molecular characterization of croaker elovl5. Here, we report the full- length cDNA sequence of croaker elovl4, which contained 1794 bp (excluding the polyA tail), including 909 bp of coding region that encoded a polypeptide of 302 amino acids possessing all the characteristic features of Elovl proteins. Functional studies showed that croaker Elovl5, displayed high elongation activity towards C18 and C20 PUFA, with only low activity towards C22 PUFA. In contrast, croaker Elovl4 could e ectively convert both C20 and C22 PUFA to longer polyenoic products up to C34. n-3 LC-PUFA suppressed transcription of the two elongase genes, as well as srebp-1 and lxr&alpha;, major regulators of hepatic lipid metabolism. The results of dual-luciferase reporter assays and in vitro studies both indicated that the transcriptions of elovl5 and elovl4 elongases could be regulated by Lxr&alpha;. Moreover, Lxr&alpha; could mediate the transcription of elovl4 directly or indirectly through regulating the transcription of srebp-1. The above ndings contribute further insight and understanding of the mechanisms regulating LC-PUFA biosynthesis in marine sh species

Temporal trends in guideline-recommended cardiometabolic testing completeness before initiating immune checkpoint inhibitors: A cohort study

Research letter