26 research outputs found
Deformation der karbonatischen Espanola-Formation im zentralen Teil der Sudbury-Impaktstruktur, Kanada
Archaische Granitoide und palÀoproterozoische
Metasedimente der Huronian
Supergroup werden von dem
schĂŒsselförmigen und partiell erodierten
1.85 Ga alten Impaktschmelzkomplex
der Sudbury-Impaktstruktur ĂŒberlagert.
Huronische Metasedimente und
deren basaler Kontakt zum granitoiden Grundgebirge stehen in einer Entfernung
bis zu 15km von dem lagigen
Komplex und um diesen herum steil.
Obwohl diese Steilstellung durch die Bildung
eines impakt-induzierten Zentralberges
erklÀrt werden kann, ist unklar,
ob orogene Verformung vor dem Impakt
an der Steilstellung beteiligt war. Um
hierĂŒber Aufschluss zu gewinnen, wurden
die basalen Huronischen Einheiten,
insbesondere die karbonatische Espanola
Formation und deren benachbarte
Metakonglomerate und Metasandsteine,
nordöstlich des Impaktschmelzkomplexes
strukturell untersucht. Aufgrund er
NÀhe der metasedimentÀren Einheiten
zu dem 2,5km mÀchtigen
Schmelzkomplex wurde daher auch dessen
möglicher thermischer Einfluss auf
die Metasedimente untersucht...conferenc
Deformation mechanisms in the eastern Sudbury Igneous Complex, Canada: Evidence for meteorite impact into an active orogen
The 1.85 Ga Sudbury Igneous Complex (SIC) in central Ontario is now widely considered to be the erosional remnant of a deformed paleo-horizontal impact melt sheet, about 2.5 km in thickness. Deformed impact melt breccias of the Onaping Formation and postimpact metasedimentary rocks overlie
the layered SIC, which in turn rests on shocked Archean basement and Paleoproterozoic cover rocks. The main
mass of the Igneous Complex is subdivided from top to bottom into granophyre, quartz-gabbro and norite layers. Previous workers considered noncylindrical folding and NW-directed reverse faulting as the main structural processes that formed the asymmetric, syn-formal geometry of the SIC apparent in map view and seismic section. Structural studies support this
model in the southern part of the impact structure, where greenschist-facies metamorphic tectonites of the South
Range Shear Zone (SRSZ) accomplished structural uplift of the southern SIC by NW-directed reverse shearing. However,
little evidence for pervasive ductile strain has been reported from the weakly metamorphosed eastern part of the SIC, the East Range, which is characterised by steep basal dips and maximal curvature in plan view. The objective of this study is to assess the
structural inventory of the East Range in terms of post-emplacement deformation
mechanisms. Our interpretation is
based on published and newly acquired
structural data.
Planar mineral shape fabrics of cumulate
plagioclase and pyroxene are developed
in the intermediate quartz-gabbro
and lower norite layers of the southern
East Range SIC. Microstructures
show little intracrystalline deformation
in quartz. Euhedral cumulate plagioclase
retains an angular outline indicating
magmatic mineral fabric development.
This magmatic foliation is concordant
to SIC contacts or large-scale
discontinuities in their vicinity (Fig. 1).
Magmatic fabrics are observed rarely in
the northern portion of the East Range.
Here, tectonic foliations and SâC fabrics
are developed sporadically at, and
concordant to, brittle structures striking
NâS. A weak tectonic foliation defined
by chlorite that replaces magmatic
minerals is developed in the upper granophyric
SIC of the NE-lobe that connects
the SICâs North and East Ranges
via a 105° arc. This foliation grades
into a shape-preferred orientation of primary,
i.e., magmatic, mafic minerals observed
in the lower granophyre and underlying
layers of the SIC. Mineral fabrics
observed in the NE-lobe SIC are
concordant to metamorphic foliations
developed in the overlying Onaping Formation
breccias. Both foliations strike
parallel to the NE-Lobeâs acute bisectrix
and, thus, display an axial-planar
geometry typical for fabrics formed in
the core of a buckle fold (Fig. 1). Brittle
structures including centimetre-scale
shear-fractures to kilometre-scale faultzones
are observed in the eastern SIC and its host rocks. Largescale
faults striking NâS cut the NElobeâs
eastern limb causing variable
magnitudes of strike separation of
SIC contacts. Centimetre- to metrescale,
brittle faults and chlorite-filled
brittle-ductile shear-zones occur pervasively
in the eastern SIC, often causing
centimetre-scale offset of markers.
Microstructures from first-order
fault-zones indicate deformation at, and
below, greenschist-facies metamorphic
conditions.
The concordance of magmatic and tectonic
mineral shape fabrics in the NElobe
indicates progressive deformation
of the SIC during cooling from the
magmatic state to lower greenschistfacies
metamorphic conditions. Synmagmatic
deformation of the SIC suggests
that it was emplaced during ongoing
orogenic deformation. Furthermore,
maximum principal stress directions
inferred from inversion of faultslip
data collected in the Onaping Formation
are orthogonal to metamorphic
foliation surfaces at the same localities.
This points to a similar deformation
regime in the Onaping Formation
during ductile and brittle deformation.
The concordance of magmatic,
metamorphic and brittle fabrics is explained
best by a single progressive deformation
event that was active while
the SIC cooled and solidified. The lack
of pervasive ductile deformation fabrics
in the East Range SIC can be explained
by rapid cooling of the impact
melt sheet (within 100â500 ka) with respect
to natural tectonic strain rates.
While the geometry of mineral fabrics
in the study area is compatible with
large-scale, non-cylindrical folding, the
low levels of ductile deformation suggest
that shape-change of the eastern SIC
has been accomplished mainly by discontinuous
deformation. This deformation
mechanism may have accomplished
bulk NW-SE shortening that was accommodated
by reverse shearing within
the SRSZ, resulting in large strike separations
of SIC contacts observed in the
western part of the impact structure.
By contrast, the eastern SIC may have
accomplished such shortening by brittleductile,
non-cylindrical folding at the
eastern terminus of the SRSZ. The complex
post-impact deformation pattern of
the central Sudbury Structure results
from impact into an active orogen.conferenc
A Scramjet Engine Model Including Effects of Precombustion Shocks and Dissociation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76382/1/AIAA-2008-4619-101.pd
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
Evaluation of epiandrosterone as a longâterm marker of testosterone use
Identification and evaluation of long-term markers is crucial in prolonging the detection window for anabolic steroid abuse in sport. Recently, sulfoconjugated epiandrosterone was identified as a potential long-term marker for the abuse of certain endogenous anabolic agents, including testosterone, which continues to be widely used as a performance enhancing agent in sport. To evaluate the applicability of epiandrosterone sulfate as a marker for testosterone use, administration studies were conducted with multiple modes of testosterone administration - transdermal, intramuscular, and subcutaneous. A modified sample preparation method was used to collect both glucuronidated and sulfoconjugated analytes of interest. Carbon isotope ratio measurements from the administration studies are presented here. Epiandrosterone was less effective than the conventionally used target compounds for detection of the low dose application (transdermal gel). With intramuscular administration, epiandrosterone was more diagnostic than with transdermal administration, but it did not prolong the detection window more than the conventional target compounds. With subcutaneous administration, the doses administered to the subjects were varied and the effect on the epiandrosterone values was dependent on the magnitude of the dose administered. Epiandrosterone does not appear to be a useful marker in the detection of low dose testosterone administration. It is responsive to higher dose administration, but it does not provide an extension of the detection window relative to conventional target compounds
Evaluation of epiandrosterone as a long-term marker of testosterone use
Identification and evaluation of long-term markers is crucial in prolonging the detection window for anabolic steroid abuse in sport. Recently, sulfoconjugated epiandrosterone was identified as a potential long-term marker for the abuse of certain endogenous anabolic agents, including testosterone, which continues to be widely used as a performance enhancing agent in sport. To evaluate the applicability of epiandrosterone sulfate as a marker for testosterone use, administration studies were conducted with multiple modes of testosterone administration - transdermal, intramuscular, and subcutaneous. A modified sample preparation method was used to collect both glucuronidated and sulfoconjugated analytes of interest. Carbon isotope ratio measurements from the administration studies are presented here. Epiandrosterone was less effective than the conventionally used target compounds for detection of the low dose application (transdermal gel). With intramuscular administration, epiandrosterone was more diagnostic than with transdermal administration, but it did not prolong the detection window more than the conventional target compounds. With subcutaneous administration, the doses administered to the subjects were varied and the effect on the epiandrosterone values was dependent on the magnitude of the dose administered. Epiandrosterone does not appear to be a useful marker in the detection of low dose testosterone administration. It is responsive to higher dose administration, but it does not provide an extension of the detection window relative to conventional target compounds