Shuttle TPS thermal performance and analysis methodology

Thermal performance of the thermal protection system was approximately as predicted. The only extensive anomalies were filler bar scorching and over-predictions in the high Delta p gap heating regions of the orbiter. A technique to predict filler bar scorching has been developed that can aid in defining a solution. Improvement in high Delta p gap heating methodology is still under study. Minor anomalies were also examined for improvements in modeling techniques and prediction capabilities. These include improved definition of low Delta p gap heating, an analytical model for inner mode line convection heat transfer, better modeling of structure, and inclusion of sneak heating. The limited number of problems related to penetration items that presented themselves during orbital flight tests were resolved expeditiously, and designs were changed and proved successful within the time frame of that program

Induction of tolerance to a murine fibrosarcoma in two zones of dosage--the involvement of suppressor cells.

Small size inocula (10(1)-10(3) cells) of cells from a syngeneic methylcholanthrene-induced fibrosarcoma (FSA) induced tolerance when injected s.c. into C3Hf mice. Mice were unable to respond to subsequent challenge with moderate, immunogenic doses of FSA. Tolerance was demonstrated in an in vivo transfer (Winn) assay and an in vitro tumour-specific TH cell assay. Low zone tolerance was associated with the presence of tumour-specific TS cells in the spleen. Moderate size inocula (10(4)-10(6) FSA cells) were immunogenic but larger cell doses (greater than 10(6)) were again tolerogenic. In the high zone, tolerance was associated with both tumour-specific TS cells and non T suppressor cells that were not tumour-specific. These results support the view that immunogenic tumours, as they grow from small cell numbers, might be able to escape host surveillance by specifically tolerizing the immune system. They also suggest that large tumour burdens can interfere with the host's immune response by inducing suppressor cells

Differential expression of microRNA-206 and its target genes in pre-eclampsia

Objectives: Pre-eclampsia is a multi-system disease that significantly contributes to maternal and fetal morbidity and mortality. In this study, we used a non-biased microarray approach to identify novel circulating miRNAs in maternal plasma that may be associated with pre-eclampsia. Methods: Plasma samples were obtained at 16 and 28 weeks of gestation from 18 women who later developed pre-eclampsia (cases) and 18 matched women with normotensive pregnancies (controls). We studied miRNA expression profiles in plasma and subsequently confirmed miRNA and target gene expression in placenta samples. Placental samples were obtained from an independent cohort of 19 women with pre-eclampsia matched with 19 women with normotensive pregnancies. Results: From the microarray, we identified 1 miRNA that was significantly differentially expressed between cases and controls at 16 weeks of gestation and 6 miRNAs that were significantly differentially expressed at 28 weeks. Following qPCR validation only one, miR-206, was found to be significantly increased in 28 week samples in women who later developed pre-eclampsia (1.4 fold change ± 0.2). The trend for increase in miR-206 expression was mirrored within placental tissue from women with pre-eclampsia. In parallel, IGF-1, a target gene of miR-206, was also found to be down-regulated (0.41 ± 0.04) in placental tissue from women with pre-eclampsia. miR-206 expression was also detectable in myometrium tissue and trophoblast cell lines. Conclusions: Our pilot study has identified miRNA-206 as a novel factor up-regulated in pre-eclampsia within the maternal circulation and in placental tissue

Designing a seismic program for an industrial CCS site: Trials and tribulations

AbstractDesigning a seismic characterization and monitoring program for a site with high levels of industrial and cultural infrastructure is by not trivial. At the MGSC Phase III project site, a combination of 3D surface seismic and VSP surveys will be used for site characterization and to monitor the injected CO2. The sparse existing data have been carefully analyzed to design 3D surface seismic and VSP surveys that will fit within the surface constraints at the site and meet the greater objectives of the project. The seismic data will be used to map formation heterogeneities and characterize fractures

Host Patch Traits Have Scale‐Dependent Effects On Diversity In A Stickleback Parasite Metacommunity

Many metacommunities are distributed across habitat patches that are themselves aggregated into groups. Perhaps the clearest example of this nested metacommunity structure comes from multi‐species parasite assemblages, which occupy individual hosts that are aggregated into host populations. At both spatial scales, we expect parasite community diversity in a given patch (either individual host or population) to depend on patch characteristics that affect colonization rates and species sorting. But, are these patch effects consistent across spatial scales? Or, do different processes govern the distribution of parasite community diversity among individual hosts, versus among host patches? To answer these questions, we document the distribution of parasite richness among host individuals and among populations in a metapopulation of threespine stickleback Gasterosteus aculeatus. We find some host traits (host size, gape width) are associated with increased parasite richness at both spatial scales. Other patch characteristics affect parasite richness only among individuals (sex), or among populations (lake size, lake area, elevation and population mean heterozygosity). These results demonstrate that some rules governing parasite richness in this metacommunity are shared across scales, while others are scale‐specific

Long-term observations of pteropod phenology along the Western Antarctic Peninsula

Shifts in phenology – annually occurring life history events – have been observed among many marine organisms due to global warming. We examined if phenological changes in the pteropod (pelagic snail) Limacina helicina antarctica have occurred along the Western Antarctic Peninsula, one of the most intensely warming regions on Earth, which would have important implications for regional food web dynamics. Pteropod shell diameters were analyzed from samples collected in the Palmer Antarctica Long-Term Ecological Research (PAL LTER) program year-round sediment trap from 2004 to 2018. There was considerable interannual variability in the time of appearance of a new pteropod cohort, which ranged from day of year 22–255, but no long-term, directional change. Mean L. h. antarctica growth rate for the time series was 0.009 mm day−1 and there was no significant long-term change in growth rate. This study represents the first in the Southern Ocean to illustrate that pteropods actively grow throughout the winter season. Sea ice was the dominant driver of pteropod phenology, with earlier sea ice retreat the year prior, lower winter sea surface temperature (SST) the year prior, and higher primary productivity in the same year leading to earlier pteropod time of appearance. Similarly, more open water with higher autumn SST, both the year prior, and elevated chlorophyll a the same year, promoted faster pteropod growth. These results indicate that while pteropods are responsive to considerable environmental variability, their phenology has remained relatively stable. The identified responses of pteropod phenology to environmental shifts are key for determining future effects of climate change on biogeochemical cycling and plankton trophic interactions in the region

Portable magnetometry for detection of biomagnetism in ambient environments

We present a method of optical magnetometry with parts-per-billion resolution that is able to detect biomagnetic signals generated from the human brain and heart in Earth's ambient environment. Our magnetically silent sensors measure the total magnetic field by detecting the free-precession frequency of highly spin-polarized alkali metal vapor. A first-order gradiometer is formed from two magnetometers that are separated by a 3 cm baseline. Our gradiometer operates from a laptop consuming 5 W over a USB port, enabled by state-of-the-art micro-fabricated alkali vapor cells, advanced thermal insulation, custom electronics, and laser packages within the sensor head. The gradiometer obtains a sensitivity of 16 fT/cm/Hz$^{1/2}$ outdoors, which we use to detect neuronal electrical currents and magnetic cardiography signals. Recording of neuronal magnetic fields is one of a few available methods for non-invasive functional brain imaging that usually requires extensive magnetic shielding and other infractructure. This work demonstrates the possibility of a dense array of portable biomagnetic sensors that are deployable in a variety of natural environments

Fractional diffusions with time-varying coefficients

This paper is concerned with the fractionalized diffusion equations governing the law of the fractional Brownian motion $B_H(t)$. We obtain solutions of these equations which are probability laws extending that of $B_H(t)$. Our analysis is based on McBride fractional operators generalizing the hyper-Bessel operators $L$ and converting their fractional power $L^{\alpha}$ into Erd\'elyi--Kober fractional integrals. We study also probabilistic properties of the r.v.'s whose distributions satisfy space-time fractional equations involving Caputo and Riesz fractional derivatives. Some results emerging from the analysis of fractional equations with time-varying coefficients have the form of distributions of time-changed r.v.'s