284 research outputs found
The non-microstates free entropy dimension of DT-operators
Dykema and Haagerup introduced the class of DT-operators and also showed that
every DT-operator generate the von Neumann algebra generated by the free group
on two generators. In this paper we prove that Voiculescu's non-microstates
free entropy dimension is 2 for all DT-operators.Comment: 30 page
The Sense-Data Delusion
This thesis project considers the philosophy of perception and the idea of empirical knowledge to guide understanding of those perceptions as veridical or non-veridical. It defines and discusses the concept of sense-data as it bears on perception. Individualâs perceptions can and do differ and we are challenged to go beyond what we actually perceive, beyond what constitutes the information that our senses â seeing, hearing, tasting, smelling, and feeling â provide to determine the truth. This fact has been thought to present a ground for arguments challenging the validity of our perceptual knowledge. Apart from physiological questions about the way our senses function and psychological questions about learning, feelings, or expectations, the question that could be called âthe questionâ of the philosophy of perception is this - what is it we perceive
Physical and psychosocial work environmental risk factors of low-back pain:protocol for a 1 year prospective cohort study
Effects of consecutive workdays and days off on low back pain, fatigue and stress:Prospective cohort study among warehouse and construction workers
Objectives Limited knowledge exists about day-to-day changes in physical and mental symptoms in warehouse and construction workers. This study investigated the associations between consecutive workdays and days off with low back pain (LBP) intensity, bodily fatigue and mental stress. Methods Participants (n=224) received daily questions for 21 days about LBP, fatigue, stress (outcome, 0-10 scales), and workdays and days off (exposure). We tested associations between 1-3 workdays (n=148) and 1-2 days off (n=158) with LBP intensity, bodily fatigue and mental stress after work and the following morning using linear mixed models with repeated measures controlling for relevant confounders. Results Consecutive workdays led to progressively increased LBP intensity, with three workdays increasing LBP intensity by 1.76 (95% CI 1.48 to 2.03) points. Bodily fatigue and mental stress increased after one workday (2.06 (95% CI 1.80 to 2.32) and 0.97 (95% CI 0.77 to 1.17) points, respectively) and remained stable for three workdays. After 1 day off, bodily fatigue and mental stress decreased -1.82 (95% CI -2.03 to -1.61) and -0.88 (95% CI -1.05 to -0.71) points, respectively, without decreasing further. In contrast, LBP intensity decreased progressively -1.09 (95% CI -1.27 to -0.91) and -1.45 (95% CI -1.67 to -1.24) points after 1 and 2 days off, respectively. Conclusions Workdays and days off affected the outcome variables differently. LBP intensity progressively increased with consecutive workdays, while workers needed 2 days off to recover. This study provides valuable knowledge about how to organise the workweek to prevent LBP, fatigue and stress, potentially reducing labour market withdrawal.</p
Typology of relations between acoustic instruments and electronics in concert music: an analysis- and composition-based approach
In the growing repertoire of âmixedâ score-based concert works (works that combine acoustic instruments with electronics), how can we gain a systematic view of patterns of practice in recent composersâ shaping of relations between acoustic instruments and electronics? The research aim has been to answer this question by building an analytical view of patterns of practice in mixed works from composers Kaija Saariaho (1952â), Luciano Berio (1925â2003), Jonathan Harvey (1939â2012) and others; and also to apply such an analytical view in my own compositional practice. Three central research outcomes have emerged as contributions to knowledge: 1. a preliminary typology of these composersâ uses of relations between acoustic instruments and electronics in mixed chamber music works; 2. a related portfolio of original mixed works for various instrumentations with computer; 3. a narrative account of the research process providing the critical basis for future work which could expand the analytical and creative results encoded in the typology. The typology is presented in the form of a catalogue of transformation paths organised in a hierarchy. Narrative description of the process that has generated the typology has emphasised an iterative intertwining of three research strands: 1. analytical interpretations of repertoire; 2. research-based practice; and 3. practice-based research. From a methodological stance, the pivotal analytic tool used is Transformation Analysis adapted from the music analysis approach of David Lewin (1933â2003) [2011a; 2011b]. Analyses of three repertoire pieces in particular: Saariahoâs NoaNoa (1992), Berioâs Altra voce (1999) and Harveyâs Ricercare una melodia (1984) have provided core elements for the typology and these analyses have formed the grounding points for the research. The portfolio of original works has been composed using a substantial input of ideas generated through analysis of these three core works as well as other repertoire; this has resulted in a series of original âparodicâ works (in the sense of Linda Hutcheon [2000]) forming the strand of research-based practice. Processes involved in the composition of these portfolio works are examined from both analytical and autoethnographic viewpoints, which form the central part of the practice-based research strand. The intertwining of the three research strands has resulted in a spiralling development of the research project: analyses have fed into compositional processes which in turn have generated more analyses. Through the iterations in the research process a typology has gradually been built, providing an interpretation of patterns of practice of the relations between acoustic instruments and electronics. This typology is specific to the repertoire examined, but the process is investigated with a view towards wider applications
Identification of endogenous retroviral reading frames in the human genome
BACKGROUND: Human endogenous retroviruses (HERVs) comprise a large class of repetitive retroelements. Most HERVs are ancient and invaded our genome at least 25 million years ago, except for the evolutionary young HERV-K group. The far majority of the encoded genes are degenerate due to mutational decay and only a few non-HERV-K loci are known to retain intact reading frames. Additional intact HERV genes may exist, since retroviral reading frames have not been systematically annotated on a genome-wide scale. RESULTS: By clustering of hits from multiple BLAST searches using known retroviral sequences we have mapped 1.1% of the human genome as retrovirus related. The coding potential of all identified HERV regions were analyzed by annotating viral open reading frames (vORFs) and we report 7836 loci as verified by protein homology criteria. Among 59 intact or almost-intact viral polyproteins scattered around the human genome we have found 29 envelope genes including two novel gammaretroviral types. One encodes a protein similar to a recently discovered zebrafish retrovirus (ZFERV) while another shows partial, C-terminal, homology to Syncytin (HERV-W/FRD). CONCLUSIONS: This compilation of HERV sequences and their coding potential provide a useful tool for pursuing functional analysis such as RNA expression profiling and effects of viral proteins, which may, in turn, reveal a role for HERVs in human health and disease. All data are publicly available through a database at
Generation of Inducible CRISPRi and CRISPRa Human Stromal/Stem Cell Lines for Controlled Target Gene Transcription during Lineage Differentiation
Background. Human bone marrow stromal/stem cells (hMSCs, also known as the skeletal stem cells or mesenchymal stem cells) are being employed to study lineage fate determination to osteoblasts, adipocytes, and chondrocytes. However, mechanistic studies employing hMSC have been hampered by the difficulty of deriving genetically modified cell lines due to the low and unstable transfection efficiency. Methods. We infected hMSC with a CRISPR/Cas9 lentivirus system, with specific inducible dCas9-coupled transcription activator or repressor: dCas9-KRAB or dCas9-VP64, respectively, and established two hMSC lines (hMSC-CRISPRi and hMSC-CRISPRa) that can inhibit or activate gene expression, respectively. The two cell lines showed similar cell morphology, cell growth kinetics, and similar lineage differentiation potentials as the parental hMSC line. The expression of KRAB-dCas9 or VP64-dCas9 was controlled by the presence or absence of doxycycline (Dox) in the cell culturing medium. To demonstrate the functionality of the dCas9-effector hMSC system, we tested controlled expression of alkaline phosphatase (ALP) gene through transfection with the same single ALP sgRNA. Results. In the presence of Dox, the expression of ALP showed 60-90% inhibition in hMSC-CRISPRi while ALP showed more than 20-fold increased expression in hMSC-CRISPRa. As expected, the ALP was functionally active and the cells showed evidence for inhibition or enhancement of in vitro osteoblast differentiation, respectively. Conclusion. hMSC-CRISPRi and hMSC-CRISPRa are useful resources to study genes and genetic pathways regulating lineage-specific differentiation of hMSC
Time and safety in defibrillation with paddles versus pads; a comparative study of two defibrillation regimes
RNAi therapeutics: Principles, prospects and challenges,
Abstract RNA interference (RNAi) was discovered less than a decade ago and already there are human clinical trials in progress or planned. A major advantage of RNAi versus other antisense based approaches for therapeutic applications is that it utilizes cellular machinery that efficiently allows targeting of complementary transcripts, often resulting in highly potent down-regulation of gene expression. Despite the excitement about this remarkable biological process for sequence specific gene regulation, there are a number of hurdles and concerns that must be overcome prior to making RNAi a real therapeutic modality, which include off-target effects, triggering of type I interferon responses, and effective delivery in vivo. This review discusses mechanistic aspects of RNAi, the potential problem areas and solutions and therapeutic applications. It is anticipated that RNAi will be a major therapeutic modality within the next several years, and clearly warrants intense investigation to fully understand the mechanisms involved
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