387 research outputs found
Teach phenomenology the bomb: Starship Troopers, the technologized body, and humanitarian warfare
Paul Verhoeven's SF films are often concerned with how the future body will be reshaped as a technological device. Starship Troopers strangely departs from Verhoeven's own work, other SF films, and current directions in cultural theory by seeing the future body as one that is more organic than mechanical. Drawing upon and challenging ideas developed by Paul Virilio, this article argues that Starship Troopers' departure from the notion of the 'post-human' mechanized body needs to be understood not as a nostalgic reassertion of de-technologized subjectivity. Rather, Verhoeven's film sees the idea of the pure body as a dangerous anachronism. And, this article further argues, Starship Troopers suggests that narratives of human salvation - such as those that arose during Nato's interventions in the Balkans - often conceal an appetite for territorial conquest
Site Improvements with Stone Columns in Stratified Silty Soils
A case history is presented where stone columns were used as a deep compaction method to increase the liquefaction resistance of stratified silty soils. Standard penetration test (SPT) and cone penetration test (CPT) resistances were used to evaluate the pre-treatment site conditions and post-treatment effects of deep compaction using stone columns. The results of the deep compaction are presented with predicted penetration resistances required to reduce the potential for liquefaction. Limitations of conventional liquefaction analysis in silty soils are discussed with regard to SPT-CPT correlations established for the site, cyclic simple shear tests performed on silts, and corrections to SPT penetration resistances for fines content
Evaluation of WRF-Sfire Performance with Field Observations from the FireFlux experiment
This study uses in-situ measurements collected during the FireFlux field
experiment to evaluate and improve the performance of coupled atmosphere-fire
model WRF-Sfire. The simulation by WRF-Sfire of the experimental burn shows
that WRF-Sfire is capable of providing realistic head fire rate-of-spread and
the vertical temperature structure of the fire plume, and, up to 10 m above
ground level, fire-induced surface flow and vertical velocities within the
plume. The model captured the changes in wind speed and direction before,
during, and after fire front passage, along with arrival times of wind speed,
temperature, and updraft maximae, at the two instrumented flux towers used in
FireFlux. The model overestimated vertical velocities and underestimated
horizontal wind speeds measured at tower heights above the 10 m, and it is
hypothesized that the limited model resolution over estimated the fire front
depth, leading to too high a heat release and, subsequently, too strong an
updraft. However, on the whole, WRF-Sfire fire plume behavior is consistent
with the interpretation of FireFlux observations. The study suggests optimal
experimental pre-planning, design, and execution of future field campaigns that
are needed for further coupled atmosphere-fire model development and
evaluation
Tristetraprolin expression and microRNA-mediated regulation during simian immunodeficiency virus infection of the central nervous system
BACKGROUND: The RNA-binding protein tristetraprolin (TTP) participates in normal post-transcriptional control of cytokine and chemokine gene expression, dysregulation of which contributes to the HIV-associated neurocognitive disorders. Transcriptional and post-transcriptional regulation of TTP has been described, including regulation by microRNA-29a. In the simian immunodeficiency virus (SIV) model of HIV CNS disease, control of cytokine/chemokine expression coincides with the end of acute phase infection. This control is lost during progression to disease. In this study, we assessed TTP regulation and association with cytokine regulation in the brain during SIV infection. RESULTS: Quantitation of TTP expression over the course of SIV infection revealed downregulation of TTP during acute infection, maintenance of relatively low levels during asymptomatic phase, and increased expression only during late-stage CNS disease, particularly in association with severe disease. The ability of miR-29a to regulate TTP was confirmed, and evidence for additional miRNA targeters of TTP was found. However, increased miR-29a expression in brain was not found to be significantly negatively correlated with TTP. Similarly, increased TTP during late-stage disease was not associated with lower cytokine expression. CONCLUSIONS: TTP expression is regulated during SIV infection of the CNS. The lack of significant negative correlation of miR-29a and TTP expression levels suggests that while miR-29a may contribute to TTP regulation, additional factors are involved. Reduced TTP expression during acute infection is consistent with increased cytokine production during this phase of infection, but the increases in TTP observed during late-stage infection were insufficient to halt runaway cytokine levels. While antisense inhibitors of the post-transcriptional targeters of TTP identified here could conceivably be used further to augment TTP regulation of cytokines, it is possible that high levels of TTP are undesirable. Additional research is needed to characterize members of the miRNA/TTP/cytokine regulatory network and identify nodes that may be best targeted therapeutically to ameliorate the effects of chronic inflammation in retrovirus-associated CNS disease
Recommended from our members
Systemic sclerosis is associated with specific alterations in gastrointestinal microbiota in two independent cohorts.
ObjectiveTo compare faecal microbial composition in patients with systemic sclerosis (SSc) from 2 independent cohorts with controls and to determine whether certain genera are associated with SSc-gastrointestinal tract (GIT) symptoms.DesignAdult patients with SSc from the University of California, Los Angeles (UCLA) and Oslo University Hospital (OUH) and healthy controls participated in this study (1:1:1). All participants provided stool specimens for 16S rRNA sequencing. Linear discriminant analysis effect size demonstrated genera with differential expression in SSc. Differential expression analysis for sequence count data identified specific genera associated with GIT symptoms as assessed by the GIT 2.0 questionnaire.ResultsThe UCLA-SSc and OUH-SSc cohorts were similar in age (52.1 and 60.5â
years, respectively), disease duration (median (IQR): 6.6 (2.5-16.4) and 7.0 (1.0-19.2) years, respectively), gender distribution (88% and 71%, respectively), and GIT symptoms (mean (SD) total GIT 2.0 scores of 0.7 (0.6) and 0.6 (0.5), respectively). Principal coordinate analysis illustrated significant microbial community differences between SSc and controls (UCLA: p=0.001; OUH: p=0.002). Patients with SSc had significantly lower levels of commensal genera deemed to protect against inflammation, such as Bacteroides (UCLA and OUH), Faecalibacterium (UCLA), Clostridium (OUH); and significantly higher levels of pathobiont genera, such as Fusobacterium (UCLA), compared with controls. Increased abundance of Clostridium was associated with less severe GIT symptoms in both cohorts.ConclusionsThe present analysis detected specific aberrations in the lower GIT microbiota of patients with SSc from 2 geographically and ethnically distinct cohorts. These findings suggest that GIT dysbiosis may be a pathological feature of the SSc disease state
Finding Orientations of Supersingular Elliptic Curves and Quaternion Orders
Orientations of supersingular elliptic curves encode the information of an
endomorphism of the curve. Computing the full endomorphism ring is a known hard
problem, so one might consider how hard it is to find one such orientation. We
prove that access to an oracle which tells if an elliptic curve is
-orientable for a fixed imaginary quadratic order
provides non-trivial information towards computing an endomorphism
corresponding to the -orientation. We provide explicit algorithms
and in-depth complexity analysis.
We also consider the question in terms of quaternion algebras. We provide
algorithms which compute an embedding of a fixed imaginary quadratic order into
a maximal order of the quaternion algebra ramified at and . We
provide code implementations in Sagemath which is efficient for finding
embeddings of imaginary quadratic orders of discriminants up to , even
for cryptographically sized
Conditional deletion reveals a cell-autonomous requirement of SLP-76 for thymocyte selection
The SH2 domain containing leukocyte phosphoprotein of 76 kD (SLP-76) is critical for pre-TCRâmediated maturation to the CD4+CD8+ double positive (DP) stage in the thymus. The absolute block in SLP-76null mice at the CD4âCD8âCD44âCD25+ (double-negative 3, DN3) stage has hindered our understanding of the role of this adaptor in αÎČ TCR-mediated signal transduction in primary thymocytes and peripheral T lymphocytes. To evaluate the requirements for SLP-76 in these events, we used a cre-loxP approach to generate mice that conditionally delete SLP-76 after the DN3 checkpoint. These mice develop DP thymocytes that express the αÎČ TCR on the surface, but lack SLP-76 at the genomic DNA and protein levels. The DP compartment has reduced cellularity in young mice and fails to undergo positive selection to CD4+ or CD8+ single positive (SP) cells in vivo or activation-induced cell death in vitro. A small number of CD4+SP thymocytes are generated, but these cells fail to flux calcium in response to an αÎČ TCR-generated signal. Peripheral T cells are reduced in number, lack SLP-76 protein, and have an abnormal surface phenotype. These studies show for the first time that SLP-76 is required for signal transduction through the mature αÎČ TCR in primary cells of the T lineage
Induction of antibody-mediated neutralization in SIVmac239 by a naturally acquired V3 mutation
AbstractAchieving humoral immunity against human immunodeficiency virus (HIV) is a major obstacle in AIDS vaccine development. Despite eliciting robust humoral responses to HIV, exposed hosts rarely produce broadly neutralizing antibodies. The present study utilizes simian immunodeficiency virus (SIV) to identify viral epitopes that conferred antibody neutralization to clone SIV/17E-CL, an in vivo variant derived from neutralization resistant SIVmac239. Neutralization assays using rhesus macaque monoclonal antibodies were performed on viruses engineered to express single or multiple amino acid mutations. Results identified a single amino acid mutation, P334R, in the carboxy-terminal half of the V3 loop as a critical residue that induced neutralization while retaining normal glycoprotein expression on the surface of the virus. Furthermore, the R334 residue yielded neutralization sensitivity by antibodies recognizing diverse conformational and linear epitopes of gp120, suggesting that neutralization phenotype was a consequence of global structural changes of the envelope protein rather than a specific site epitope
Recommended from our members
Treatment With Mycophenolate and Cyclophosphamide Leads to Clinically Meaningful Improvements in PatientâReported Outcomes in Scleroderma Lung Disease: Results of Scleroderma Lung Study II
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/156000/1/acr211125.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156000/2/acr211125_am.pd
- âŠ