4,651 research outputs found
Regulation of human dendritic cells and T cells by adenovirus vectors types 5 and 35 : implications for vaccine design
Following viral infection or vaccination dendritic cells (DC) perform an intricate series
of roles at the interface of innate and adaptive immunity. Peripheral DC recognition of
pathogen associated molecular patterns initiates signaling cascades leading to
morphological and phenotypic maturation. The differentiation to a mature phenotype
licenses DCs to efficiently prime T- and B-lymphocytes. Thus, DCs shape early innate
immune responses that limit viral replication and initiate the generation of protective
and adaptive immunological memory.
In this thesis, we began by studying the interaction of human primary DCs with human
adenovirus (AdV). While the causative agent of a variety of human diseases, AdVs are
also a valuable research tool for probing virological, immunological, and cellular
mechanisms of nature. Recombinant human AdVs (rAdV), rendered replication
incompetent and thus unable to cause disease, have gained prominence as gene delivery
vehicles in multiple vaccine trials. In light of the clinical importance of AdV vectors,
we employed a reductionist approach to study mechanisms of virus-mediated
regulation of human DC function. Since DCs activate adaptive immunity, we extended
our investigations to the impact of rAdV on the activation of T-lymphocytes. These
studies are particularly relevant since the induction of potent T-cell responses is one
objective of rAdV based vaccine vectors.
In assessing the interaction of rAdV with primary human blood myeloid and
plasmacytoid DC subsets, we found that activation of these cells was dependent on
rAdV type. rAdV-35 more efficiently infected DCs than rAdV-5, and matured blood
DCs and strongly induced interferon-! in plasmacytoid DCs. Infection by rAdV-35
was dependent on the receptor CD46, whereas the receptor for rAdV-5 was less clear.
We then showed that lactoferrin facilitated rAdV-5 infection of multiple DC subsets in
a similar manner to epithelial cells. rAdV-exposed DCs were able to process and
present rAdV encoded transgenes and activate polyfunctional memory T cells, which
indicated that rAdV infected DCs retained their antigen presentation capacity.
However, it remained unclear from these studies whether rAdV affected the activation
of naive T cells, which is an important step for vaccination. To this end, rAdV-35 was
found to strongly inhibit activation of naive CD4+ T cells through binding of its
cellular attachment receptor, CD46. Attenuated activation was characterized by lower
proliferation and IL-2 production, as well as deficient NF-!B nuclear translocation.
Further studies showed that cross-linking with CD46 monoclonal antibodies and
recombinant trimeric rAdV-35 knob proteins was sufficient to cause similar
suppression as the whole virus, substantiating the role of CD46 in regulating CD4+ T cell function.
Our findings provide insights into the mechanisms by which host immune cells respond
to rAdV and also how the virus may act to modulate host cell function. These findings
may also guide the development of rAdVs as vaccine vector
When Taint Teams Go Awry: Laundering Unconstitutional Violations of the Fourth Amendment
In this Article, we examine the legal landscape in which taint teams operate, why taint teams are constitutionally problematic, and propose a solution to protect the attorney-client privilege. In Part I, we will first describe what taint teams are supposed to protect—attorney-client privilege. Next, we review how a taint team gets its documents to review, namely the doctrine surrounding (secret) search warrants. Part I ends with a non exhaustive summary of remedies available when attorney-client privilege is violated during searches. In Part II, we explain the current policies and practices surrounding taint teams, including sources of procedure for taint teams and the use of warrants for electronic information. Part II concludes with a summary of the lopsided pre-2019 split in authority on the use of taint teams in federal criminal prosecutions. Part III is devoted to examining the constitutional and practical shortcomings of the current formulation of taint teams. Using a 2019 case that forcefully criticized the use of taint teams, we explore constitutional issues under the Bill of Rights and separation-of-powers doctrine. Part III concludes with a discussion of the federal government’s proposed solution to these judicially identified deficiencies and an explanation of why that solution is wholly inadequate. In Part IV, we review a series of possible solutions already in practice in various jurisdictions and then propose a new solution to resolve the constitutional issues of taint teams and protect attorney-client privilege. Specifically, we propose a new structure that locates privilege-review teams as a function within the federal public defender’s office, where judicial officers make recommended privilege determinations subject to judicial review. We explain that this solves the Fourth Circuit’s constitutional criticisms while simultaneously recognizing the need to review potentially privileged materials by someone other than the target of an investigation
Investigation and suppression of high dynamic response encountered on an elastic supercritical wing
The DAST Aeroelastic Research Wing had been previously in the NASA Langley TDT and an unusual instability boundary was predicted based upon supercritical response data. Contrary to the predictions, no instability was found during the present test. Instead a region of high dynamic wing response was observed which reached a maximum value between Mach numbers 0.92 and 0.93. The amplitude of the dynamic response increased directly with dynamic pressure. The reponse appears to be related to chordwise shock movement in conjunction with flow separation and reattachment on the upper and lower wing surfaces. The onset of flow separation coincided with the occurrence of strong shocks on a surface. A controller was designed to suppress the wing response. The control law attenuated the response as compared with the uncontrolled case and added a small but significant amount of damping for the lower density condition
Essential Roles of Drosophila Inner Centromere Protein (Incenp) and Aurora B in Histone H3 Phosphorylation, Metaphase Chromosome Alignment, Kinetochore Disjunction, and Chromosome Segregation
We have performed a biochemical and double-stranded RNA-mediated interference (RNAi) analysis of the role of two chromosomal passenger proteins, inner centromere protein (INCENP) and aurora B kinase, in cultured cells of Drosophila melanogaster. INCENP and aurora B function is tightly interlinked. The two proteins bind to each other in vitro, and DmINCENP is required for DmAurora B to localize properly in mitosis and function as a histone H3 kinase. DmAurora B is required for DmINCENP accumulation at centromeres and transfer to the spindle at anaphase. RNAi for either protein dramatically inhibited the ability of cells to achieve a normal metaphase chromosome alignment. Cells were not blocked in mitosis, however, and entered an aberrant anaphase characterized by defects in sister kinetochore disjunction and the presence of large amounts of amorphous lagging chromatin. Anaphase A chromosome movement appeared to be normal, however cytokinesis often failed. DmINCENP and DmAurora B are not required for the correct localization of the kinesin-like protein Pavarotti (ZEN-4/CHO1/MKLP1) to the midbody at telophase. These experiments reveal that INCENP is required for aurora B kinase function and confirm that the chromosomal passengers have essential roles in mitosis
LEND ME YOUR EAAR: ENHANCING THE AFTER ACTION REVIEW TO INCREASE TACTICAL LEARNING
Leaders need more opportunities to train with their units to hone their skills. Leaders use After Action Reviews to improve themselves and their units. The After Action Review has existed since the 1970s and has not substantially changed in that time. New technological advancements in the last several years offer the opportunity to enhance the efficacy of the After Action Review for future leaders and units. One of these new technologies is virtual reality. Virtual reality presents trainers the ability to control all aspects of the training environment. It also enables thorough data collection and the ability to rapidly run through a scenario again.
This project sought to identify the information gaps in live training and determine whether virtual reality enables tactical learning at the individual level. Using surveys and experimentation, the team concluded that virtual reality scenarios in concert with After Action Reviews can be used for tactical learning at the individual level. Through the course of the experiment, the team also discovered that servicemembers take advantage of opportunities to improve themselves regardless of their performance.Major, United States ArmyMajor, United States ArmyCaptain, United States ArmyMajor, United States ArmyMajor, United States ArmyApproved for public release. Distribution is unlimited
Optical Polarization and Spectral Variability in the M87 Jet
During the last decade, M87's jet has been the site of an extraordinary
variability event, with one knot (HST-1) increasing by over a factor 100 in
brightness. Variability was also seen on timescales of months in the nuclear
flux. Here we discuss the optical-UV polarization and spectral variability of
these components, which show vastly different behavior. HST-1 shows a highly
significant correlation between flux and polarization, with P increasing from
at minimum to >40% at maximum, while the orientation of its electric
vector stayed constant. HST-1's optical-UV spectrum is very hard
(, ), and displays "hard lags"
during epochs 2004.9-2005.5, including the peak of the flare, with soft lags at
later epochs. We interpret the behavior of HST-1 as enhanced particle
acceleration in a shock, with cooling from both particle aging and the
relaxation of the compression. We set 2 upper limits of
parsecs and 1.02 on the size and advance speed of the flaring region. The
slight deviation of the electric vector orientation from the jet PA, makes it
likely that on smaller scales the flaring region has either a double or twisted
structure. By contrast, the nucleus displays much more rapid variability, with
a highly variable electric vector orientation and 'looping' in the
plane. The nucleus has a much steeper spectrum () but
does not show UV-optical spectral variability. Its behavior can be interpreted
as either a helical distortion to a steady jet or a shock propagating through a
helical jet.Comment: 14 pages, 7 figures, ApJ, in pres
Creating restoration landscapes: partnerships in large-scale conservation in the UK
It is increasingly recognized that ecological restoration demands conservation action beyond the borders of existing protected areas. This requires the coordination of land uses and management over a larger area, usually with a range of partners, which presents novel institutional challenges for conservation planners. Interviews were undertaken with managers of a purposive sample of large-scale conservation areas in the UK. Interviews were open-ended and analyzed using standard qualitative methods. Results show a wide variety of organizations are involved in large-scale conservation projects, and that partnerships take time to create and demand resilience in the face of different organizational practices, staff turnover, and short-term funding. Successful partnerships with local communities depend on the establishment of trust and the availability of external funds to support conservation land uses. We conclude that there is no single institutional model for large-scale conservation: success depends on finding institutional strategies that secure long-term conservation outcomes, and ensure that conservation gains are not reversed when funding runs out, private owners change priorities, or land changes hands
Macrobenthos Population Changes in Crystal Lake, Arkansas, Subsequent to Cage Culture Fish
A three-year study was conducted to determine the possible effects of cage culture of fish on the environment of Crystal Lake, Arkansas. The investigation consisted of three periods: pre- (November 1971-October 1972), during- (November 1972-October 1973), and post- (November 1973-October 1974) cage culture. Numbers and biomass of benthos per square meter for pre-, during-, and post-culture periods were 1353 (10.0g), 730 (8.8g), and 1028 (4.1g), respectively. Numerically, Chaoborus sp., Chironomidae, and Oligochaeta comprised more than 97%. Chaoborus was the most numerous organism before fish culture (\u3e68%), but dominance shifted to the Oligochaeta (\u3e58%) after culture
Bilateral redundancy gain and callosal integrity in a man with callosal lipoma: a diffusion-tensor imaging study
We investigated whether abnormalities in the structural organisation of the corpus callosum in the presence of curvilinear lipoma are associated with increased facilitation of response time to bilateral stimuli, an effect known as the redundancy gain. A patient (A.J.) with a curvilinear lipoma of the corpus callosum, his genetically-identical twin, and age-matched control participants made speeded responses to luminant stimuli. Structural organisation of callosal regions was assessed with diffusion-tensor imaging. A.J. was found to have reduced structural integrity in the splenium of the corpus callosum and produced a large redundancy gain suggestive of neural summation
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