10,805 research outputs found
Professor Dan L Bader, scientist, mentor, and friend
No full textThis special edition of the Journal of Tissue Viability provides a collection of scientific excellence led by the late Professor Dan L Bader. These papers form part of an academic career spanning over 40 years, working in collaboration with partners from around the world to provide novel insights into factors effecting tissue viability and technologies to promote wound prevention. Dan's great ambition was to translate his work from ‘bench to bedside’, using the highest quality experimental data [[1], [2], [3], [4], [5], [6], [7], [8]], computational modelling [9,10] and clinical studies [11,12] to create a step change in our understanding of factors which effect tissue health. This body of work originated from his career spanning several academic institutions including Queen Mary University London (QMUL), Technical University Eindhoven (TUE), and the University of Southampton (UoS).No Full Tex
Bio-dependent bed parameters as a proxy tool for sediment stability in mixed habitat intertidal areas
No full textThe stability of cohesive and non-cohesive sediments in a mixed intertidal habitat within the Ria Formosa tidal lagoon, Portugal, was examined during two field campaigns as part of the EU F-ECTS project. The cohesive strength meter Mk III was used to determine critical erosion shear stress (c) within a variety of different intertidal habitats and substrata, including Spartina maritima fields and Zostera noltii beds. The best predictor(s) for c were derived from a range of properties measured for the surface sediments (chlorophyll a, colloidal carbohydrate, water, organic content, % fraction <63 m, and seabed elevation). Pigment biomarkers were used to identify the dominant algal groups within the surface phytobenthic assemblage.Strong, seasonally dependent relationships were found between c and habitat type, chl a, colloidal carbohydrate and bed elevation. Typically, critical erosion thresholds decreased seawards, reflecting a change from biostabilisation by cyanobacteria in the upper intertidal areas, to biostabilisation by diatoms on the bare substrata of the channel edges. In the late summer/early autumn, cyanobacteria were the main sediment stabilisers, and colloidal carbohydrate was the best bio-dependent predictor of c across the entire field area. In the late winter/early spring, cyanobacterial activity was lower, and sediment stabilisation by Enteromorpha clathrata was important; the best predictor of c was bed elevation. The implications and use of proxies for sediment stability are discussed in terms of feedback and sedimentation processes operating across the intertidal area
DNA fusion gene vaccination mobilizes effective anti-leukemic cytotoxic T lymphocytes from a tolerized repertoire
No full textThe majority of known human tumor-associated antigens derive from non-mutated self proteins. T cell tolerance, essential to prevent autoimmunity, must therefore be cautiously circumvented to generate cytotoxic T cell responses against these targets. Our strategy uses DNA fusion vaccines to activate high levels of peptide-specific CTL. Key foreign sequences from tetanus toxin activate tolerance-breaking CD4+ T cell help. Candidate MHC class Ibinding tumor peptide sequences are fused to the C terminus for optimal processing and presentation. To model performance against a leukemia-associated antigen in a tolerized setting, we constructed a fusion vaccine encoding an immunodominant CTL epitopederived from Friend murine leukemia virus gag protein (FMuLVgag) and vaccinated tolerant FMuLVgag-transgenic (gag-Tg) mice. Vaccination with the construct induced epitopespecificIFN-c-producing CD8+ T cells in normal and gag-Tg mice. The frequency and avidity of activated cells were reduced in gag-Tg mice, and no autoimmune injury resulted. However, these CD8+ T cells did exhibit gag-specific cytotoxicity in vitro and in vivo. Also, epitope-specific CTL killed FBL-3 leukemia cells expressing endogenous FMuLVgag antigen and protected against leukemia challenge in vivo. These results demonstrate a simple strategy to engage anti-microbial T cell help to activate epitope-specific polyclonal CD8+ T cell responses from a residual tolerized repertoire
Engagement of PI-3-kinase mediated Protein kinase C zeta activation in protecting Friend cells from ionizing radiation-induced apoptosis
No full textMurine erythroleukemia cells (Friend) respond to ionizing radiation with the activation and nuclear translocation of p85alpha subunit of phosphatidylinositol-3-kinase (PI-3-kinase) which mediates the downstream activation and nuclear translocation of atypical Protein kinase C zeta (PKC zeta). This event occurs mainly upon high dose of ionizing radiation (15 Gy) and is concomitant to an increase in BrdU incorporation, which probably accounts for a predominant repair DNA synthesis. Following treatment with wortmannin, a relatively specific inhibitor of PI-3-kinase, both an increased number of apoptotic cells and the inhibition of protein kinase C zeta translocation were detected. Altogether the evidence suggests a potential role of the PI-3-kinase/PKC zeta pathway in protecting Friend cells from ionizing radiation-induced apoptosis offering PKC zeta for consideration as possible target of pharmacological treatments
Emergence and Collapse of Peace with Friend Selection Strategies
No full textA society consisting of agents who can freely choose to attack or not to attack others inevitably evolves into a battling society (a \'war of all against all\'). We investigated whether strategies based on C. Schmitt\'s concept of the political, the distinction of a friend and an enemy, lead to the emergence and collapse of social order. Especially, we propose \'friend selection strategies\' (FSSs), one of which we called the \'us-TFT\' (tit for tat) strategy, which requires an agent to regard one who did not attack him or his \'friends\' as a \'friend\'. We carried out evolutionary simulations on an artificial society consisting of FSS agents. As a result, we found that the us-TFT results in a peaceful society with the emergence of an us-TFT community. In addition, we found that the collapse of a peaceful society is triggered by another FSS strategy called a \'coward\'.Community, Carl Schmitt, a Friend and an Enemy, Tit for Tat, Coward, Evolutionary Simulation
Protein Kinase C zeta nuclear translocation mediates the occurrence of radioresistance in friend erythroleukemia cells
No full textFriend erythroleukemia cells require high doses (15 Gy) of ionizing radiation to display a reduced rate of proliferation and an increased number of dead cells. Since ionizing radiation can activate several signaling pathways at the plasma membrane which can lead to the nuclear translocation of a number of proteins, we looked at the intranuclear signaling system activated by Protein Kinases C, being this family of enzymes involved in the regulation of cell growth and death. Our results show an early and dose-dependent increased activity of and 6 isoforms, although PKC is the only isoform significantly active and translocated into the nuclear compartment upon low (1.5 Gy) and high (15 Gy) radiation doses. These observations are concomitant and consistent with an increase in the anti-apoptotic protein Bcl-2 level upon both radiation doses. Our results point at the involvement of the PKC pathway in the survival response to ionizing radiation of this peculiar cell line, offering PKC C for consideration as a possible target of pharmacological treatments aimed at amplifying the effect of such a genotoxic agent. (C) 2002 Wiley-Liss, Inc
The Harold C. Ernst Collection of Portable Sundials
No full textA catalog of sundials from the Harold C. Ernst Collection of Portable Sundials, and a handy reference book on the subject of portable sundials.
The sundial is the most ancient scientific instrument to come down to us unchanged. As such it is deserving of a better position in life than that of an ornament. It has played a vital part in the life of man for many thousands of years, and even today it serves us well where the mechanical watch fails. The authors particularly draw attention to the system of classifying, labeling, and cataloging sundials, described in Chapter II. This is the first attempt to bring order out of confusion in sundials
Hemispheric dominance and language proficiency levels in the four macro skills of Western Mindanao State university college students
No full textThis study was conducted to determine the relationship between the hemispheric dominance (HD) and the English proficiency (EP) scores in the four macro skills of the Western Mindanao State University college students. It hypothesized that students’ HD would have a significant correlation a) with their EP scores in listening, speaking, reading and writing, b) with their global EP score, c) with both the macro and global scores when respondents would be grouped according to age, gender and area of specialization. In this study, there were 240 respondents selected through purposive, stratified, and random sampling techniques from the 5,096 students of the Colleges of Arts and Sciences, Engineering and Education. Using the standardized HD Test, the standardized Listening and Reading Comprehension Tests, the researcher-made Speaking and Writing Skill Tests and Cloze Test and employing mainly the Pearson r for the statistical analysis, the study concluded: 1) that most of the students of the Colleges of Arts and Sciences, Engineering and Education of Western Mindanao State University were left-brained (74.6%); 2) that the students were “good” in speaking, “fair” in listening and writing skills but “ poor” in reading and in global English; 3) that there was no significant relationship between the students’ hemisphericity and their EP scores in listening, speaking, reading, writing and global proficiency tests; and 4) that a significant relationship was shown between HD and EP scores when respondents were grouped according to age and area of specialization only.hemisphericity, language performance, English, hemispheric dominance, right brain, left brain, whole brain, speaking, listening, reading, writing
Phosphoinositide Signaling in Nuclei of Friend Cells: Phospholipase C β Down-Regulation Is Related to Cell Differentiation
No full textPrevious investigations have demonstrated the existence of an autonomous intranuclear inositide cycle endowed with conventional lipid kinases and phospholipase C (PLC) which is the isoform beta in Swiss 3T3 cells, PC12 pheochromocytoma cells, human osteosarcoma SaOS-2 cells, and rat liver. The presence of PLC has been investigated in nuclei of Friend erythroleukemia cells. Both beta and gamma isoforms are present in these nuclei. When Friend cells undergo terminal erythroid differentiation in the presence of dimethyl sulfoxide the PLC beta isoform is down-regulated as shown by immunochemical and immunocytochemical analysis, by determination of enzymatic activity directly and in the presence of neutralizing monoclonal antibodies and also by Northern blot for PLC beta message. By contrast, the amount of PLC gamma and its activity are unaffected by erythroid differentiation. Thus, the presence of a nuclear PLC beta, the activity and expression of which are modulated during differentiation of erythroleukemia cells, implicates a role for nuclear phosphoinositide signaling in the processes of cell determination and indicates the nuclear PLC beta as a key enzyme of the cycle in relation to the erythroid differentiative commitment of murine erythroleukemia cells
The effects of rain on the erosion threshold of intertidal cohesive sediments
No full textIntertidal sedimentary environments are complex systems governed by interactions between physical, chemical and biological processes and parameters. Tidally induced flow and wave action are known to be an integral driving force behind the erosion, transport, deposition and consolidation cycle (ETDC) of intertidal sediments. Whilst considerable advances have been made in understanding both the physical and biological processes and their interactions in these systems, it is clear that there are gaps in our understanding. One factor that has been largely ignored to date is that of rain. Visual observations in the field and associated data indicated that rain showers during low tide are correlated with a reduction in the erosion threshold of intertidal cohesive sediments. This paper presents preliminary field and laboratory data showing the importance of rain in reducing the erosion threshold of cohesive intertidal sediments. The implications for our knowledge of, and modelling of the ETDC cycle of cohesive intertidal sediments are discussed
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