Ocean Chlorophyll Studies from a U-2 Aircraft Platform

Chlorophyll gradient maps of large ocean areas were generated from U-2 ocean color scanner data obtained over test sites in the Pacific and Atlantic Oceans. The delineation of oceanic features using the upward radiant intensity relies on an analysis method which presupposes that radiation backscattered from the atmosphere and ocean surface can be properly modeled using a measurement made at 778 nm. An estimation of the chlorophyll concentration was performed by properly ratioing radiances measured at 472 nm and 548 nm after removing the atmospheric effects. The correlation between the remotely sensed data and in-situ surface chlorophyll measurements was validated in two sets of data. The results show that the correlation between the in-situ measured chlorophyll and the derived quantity is a negative exponential function and the correlation coefficient was calculated to be -0.965

Human Mesenchymal Stromal Cells Decrease Mortality Following Intestinal Ischemia and Reperfusion Injury

Background Cellular therapy is a novel treatment option for intestinal ischemia. Bone marrow–derived mesenchymal stromal cells (BMSCs) have previously been shown to abate the damage caused by intestinal ischemia/reperfusion (I/R) injury. We therefore hypothesized that (1) human BMSCs (hBMSCs) would produce more beneficial growth factors and lower levels of proinflammatory mediators compared to differentiated cells, (2) direct application of hBMSCs to ischemic intestine would decrease mortality after injury, and (3) decreased mortality would be associated with an altered intestinal and hepatic inflammatory response. Methods Adult hBMSCs and keratinocytes were cultured on polystyrene flasks. For in vitro experiments, cells were exposed to tumor necrosis factor, lipopolysaccharides, or 2% oxygen for 24 h. Supernatants were then analyzed for growth factors and chemokines by multiplex assay. For in vivo experiments, 8- to 12-wk-old male C57Bl6J mice were anesthetized and underwent a midline laparotomy. Experimental groups were exposed to temporary superior mesenteric artery occlusion for 60 min. Immediately after ischemia, 2 × 106 hBMSCs or keratinocytes in phosphate-buffered saline were placed into the peritoneal cavity. Animals were then closed and allowed to recover for 6 h (molecular/histologic analysis) or 7 d (survival analysis). After 6-h reperfusion, animals were euthanized. Intestines and livers were harvested and analyzed for inflammatory chemokines, growth factors, and histologic changes. Results hBMSCs expressed higher levels of human interleukin (IL) 6, IL-8, vascular endothelial growth factor (VEGF), and epidermal growth factor and lower levels of IL-1, IL-3, IL-7, and granulocyte-monocyte colony-stimulating factor after stimulation. In vivo, I/R resulted in significant mortality (70% mortality), whereas application of hBMSCs after ischemia decreased mortality to 10% in a dose-dependent fashion (P = 0.004). Keratinocyte therapy offered no improvements in mortality above I/R. Histologic profiles were equivalent between ischemic groups, regardless of the application of hBMSCs or keratinocytes. Cellular therapy yielded significantly decreased murine intestinal levels of soluble activin receptor-like kinase 1, betacellulin, and endothelin, whereas increasing levels of eotaxin, monokine induced by gamma interferon (MIG), monocyte chemoattractant protein 1, IL-6, granulocyte colony-stimulating factor (G-CSF), and interferon gamma-induced protein 10 (IP-10) from ischemia were appreciated. hBMSC therapy yielded significantly higher expression of murine intestinal VEGF and lower levels of intestinal MIG compared to keratinocyte therapy. Application of hBMSCs after ischemia yielded significantly lower murine levels of hepatic MIG, IP-10, and G-CSF compared to keratinocyte therapy. Conclusions Human BMSCs produce multiple beneficial growth factors. Direct application of hBMSCs to the peritoneal cavity after intestinal I/R decreased mortality by 60%. Improved outcomes with hBMSC therapy were not associated with improved histologic profiles in this model. hBMSC therapy was associated with higher VEGF in intestines and lower levels of proinflammtory MIG, IP-10, and G-CSF in liver tissue after ischemia, suggesting that reperfusion with hBMSC therapy may alter survival by modulating the systemic inflammatory response to ischemia

Electron mean free path from angle-dependent photoelectron spectroscopy of aerosol particles

We propose angle-resolved photoelectron spectroscopy of aerosol particles as an alternative way to determine the electron mean free path of low energy electrons in solid and liquid materials. The mean free path is obtained from fits of simulated photoemission images to experimental ones over a broad range of different aerosol particle sizes. The principal advantage of the aerosol approach is twofold. Firstly, aerosol photoemission studies can be performed for many different materials, including liquids. Secondly, the size-dependent anisotropy of the photoelectrons can be exploited in addition to size-dependent changes in their kinetic energy. These finite size effects depend in different ways on the mean free path and thus provide more information on the mean free path than corresponding liquid jet, thin film, or bulk data. The present contribution is a proof of principle employing a simple model for the photoemission of electrons and preliminary experimental data for potassium chloride aerosol particles

Evaluating whole transcriptome amplification for gene profiling experiments using RNA-Seq

BACKGROUND: RNA-Seq has enabled high-throughput gene expression profiling to provide insight into the functional link between genotype and phenotype. Low quantities of starting RNA can be a severe hindrance for studies that aim to utilize RNA-Seq. To mitigate this bottleneck, whole transcriptome amplification (WTA) technologies have been developed to generate sufficient sequencing targets from minute amounts of RNA. Successful WTA requires accurate replication of transcript abundance without the loss or distortion of specific mRNAs. Here, we test the efficacy of NuGEN’s Ovation RNA-Seq V2 system, which uses linear isothermal amplification with a unique chimeric primer for amplification, using white adipose tissue from standard laboratory rats (Rattus norvegicus). Our goal was to investigate potential biological artifacts introduced through WTA approaches by establishing comparisons between matched raw and amplified RNA libraries derived from biological replicates. RESULTS: We found that 93% of expressed genes were identical between all unamplified versus matched amplified comparisons, also finding that gene density is similar across all comparisons. Our sequencing experiment and downstream bioinformatic analyses using the Tuxedo analysis pipeline resulted in the assembly of 25,543 high-quality transcripts. Libraries constructed from raw RNA and WTA samples averaged 15,298 and 15,253 expressed genes, respectively. Although significant differentially expressed genes (P < 0.05) were identified in all matched samples, each of these represents less than 0.15% of all shared genes for each comparison. CONCLUSIONS: Transcriptome amplification is efficient at maintaining relative transcript frequencies with no significant bias when using this NuGEN linear isothermal amplification kit under ideal laboratory conditions as presented in this study. This methodology has broad applications, from clinical and diagnostic, to field-based studies when sample acquisition, or sample preservation, methods prove challenging. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12896-015-0155-7) contains supplementary material, which is available to authorized users

Dressed Spin of Polarized 3He in a Cell

We report a measurement of the modification of the effective precession frequency of polarized 3He atoms in response to a dressing field in a room temperature cell. The 3He atoms were polarized using the metastability spin-exchange method. An oscillating dressing field is then applied perpendicular to the constant magnetic field. Modification of the 3He effective precession frequency was observed over a broad range of the amplitude and frequency of the dressing field. The observed effects are compared with calculations based on quantum optics formalism.Comment: 10 pages, 4 figure

Extrasolar planets and brown dwarfs around A-F type stars - VII. Theta Cygni radial velocity variations: planets or stellar phenomenon?

(abridged) In the frame of the search for extrasolar planets and brown dwarfs around early-type main-sequence stars, we present the results obtained on the early F-type star Theta Cygni. Elodie and Sophie at OHP were used to obtain the spectra. Our dedicated radial-velocity measurement method was used to monitor the star's radial velocities over five years. We also use complementary, high angular resolution and high-contrast images taken with PUEO at CFHT. We show that Theta Cygni radial velocities are quasi-periodically variable, with a ~150-day period. These variations are not due to the ~0.35-Msun stellar companion that we detected in imaging at more than 46 AU from the star. The absence of correlation between the bisector velocity span variations and the radial velocity variations for this 7 km/s vsini star, as well as other criteria indicate that the observed radial velocity variations are not due to stellar spots. The observed amplitude of the bisector velocity span variations also seems to rule out stellar pulsations. However, we observe a peak in the bisector velocity span periodogram at the same period as the one found in the radial velocity periodogram, which indicates a probable link between these radial velocity variations and the low amplitude lineshape variations which are of stellar origin. Long-period variations are not expected from this type of star to our knowledge. If a stellar origin (hence of new type) was to be confirmed for these long-period radial velocity variations, this would have several consequences on the search for planets around main-sequence stars, both in terms of observational strategy and data analysis. An alternative explanation for these variable radial velocities is the presence of at least one planet of a few Jupiter masses orbiting at less than 1 AU. (abridged)Comment: 9 pages, accepted in A

Urine THC Metabolite Levels Correlate with Striatal D2/D3 Receptor Availability

poster abstractRationale: Although the incidence of cannabis abuse/dependence in Americans is rising, the neurobiology of cannabis addiction is not well understood. Recent imaging studies have demonstrated deficits in striatal D2/D3 receptor availability in several substance-dependent populations. However, this has not been studied in chronic cannabis users. Objective: The purpose of this study was to compare striatal D2/D3 receptor availability between currently using chronic cannabis users and healthy controls. Methods: Eighteen right-handed males, age 18-35 were studied. Ten subjects were chronic cannabis users; eight were demographically matched controls. Subject eligibility was determined during a screening interview, which included SCID-I and SCID-II assessments, self-report of past substance use, and drug toxicology screening. Subjects underwent a [11C]raclopride (RAC) PET scan; striatal RAC binding potential (BPND) was calculated on a voxel-wise basis with the multilinear reference tissue method. Prior to scanning, urine samples were obtained from cannabis users for quantification of urine Δ-9-tetrahydrocannabinol (THC) and THC metabolites (11-nor-Δ-9-THC-9-carboxylic acid; THC-COOH). Statistical analyses were conducted at voxel-wise level within the striatum. Two-sample t-tests were used to test for differences in BPND between groups. For cannabis subjects, multiple regression analyses were used to test for correlations between striatal BPND and urine THC/THC metabolite levels. Results: There were no differences in BPND between cannabis smokers and healthy controls. Smokers – regardless of substance – had 10% lower D2/D3 availability than non-smokers. Voxel-wise analyses revealed that striatal RAC BPND values were associated with urine levels of cannabis metabolites. Conclusions: Cannabis and cannabis metabolites in urine, markers of recent cannabis consumption, are negatively correlated with striatal RAC BPND. This provides the first evidence that degree of cannabis use is related to changes in the central DA system. Low BPND in both cannabis and cigarette users may indicate a deficiency in D2/D3 receptors as a function of chronic exposure to either or both substances. Alternatively, endogenous dopamine levels may be higher in smokers as a result of MAO inhibition from beta-carbolines in the inhaled smoke. Additional studies are needed to understand the complex relationships between chronic cannabis use and the dopamine system

Estimation Of Reference Crop Evapotranspiration Using Fuzzy State Models

Daily evapotranspiration (ET) rates are needed for irrigation scheduling. Owing to the difficulty of obtaining accurate field measurements, ET rates are commonly estimated from weather parameters. A few empirical or semi–empirical methods have been developed for assessing daily reference crop ET, which is converted to actual crop ET using crop coefficients. The FAO Penman–Monteith method, which is now accepted as the standard method for the computation of daily reference ET, is sophisticated. It requires several input parameters, some of which have no actual measurements but are estimated from measured weather parameters. In this study, we examined the suitability of fuzzy logic for estimating daily reference ET with simpler and fewer parameters. Two fuzzy evapotranspiration models, using two or three input parameters, were developed and applied to estimate grass ET. Independent weather parameters from sites representing arid and humid climates were used to test the models. The fuzzy estimated ET values were compared with direct ET measurements from grass–covered weighing lysimeters, and with ET estimations obtained using the FAO Penman–Monteith and the Hargreaves–Samani equations. The estimated ET values from a fuzzy model using three input parameters (Syx = 0.54 mm, r2 = 0.90) were found to be comparable to ET values estimated with the FAO Penman–Monteith equation (Syx = 0.50 mm, r2 = 0.91) and were more accurate than those obtained by the Hargreaves–Samani equation (Syx = 0.66 mm, r2 = 0.53). These results show that fuzzy evapotranspiration models with simpler and fewer input parameters can yield accurate estimation of ET

Hydration dynamics at fluorinated protein surfaces

Water-protein interactions dictate many processes crucial to protein function including folding, dynamics, interactions with other biomolecules, and enzymatic catalysis. Here we examine the effect of surface fluorination on water-protein interactions. Modification of designed coiled-coil proteins by incorporation of 5,5,5-trifluoroleucine or (4S)-2-amino-4-methylhexanoic acid enables systematic examination of the effects of side-chain volume and fluorination on solvation dynamics. Using ultrafast fluorescence spectroscopy, we find that fluorinated side chains exert electrostatic drag on neighboring water molecules, slowing water motion at the protein surface

Notch ligand Delta-like 1 promotes in vivo vasculogenesis in human cord blood-derived endothelial colony forming cells

BACKGROUND AIMS: Human cord blood (CB) is enriched in circulating endothelial colony forming cells (ECFCs) that display high proliferative potential and in vivo vessel forming ability. Because Notch signaling is critical for embryonic blood vessel formation in utero, we hypothesized that Notch pathway activation may enhance cultured ECFC vasculogenic properties in vivo. METHODS: In vitro ECFC stimulation with an immobilized chimeric Notch ligand (Delta-like1(ext-IgG)) led to significant increases in the mRNA and protein levels of Notch regulated Hey2 and EphrinB2 that were blocked by treatment with γ-secretase inhibitor addition. However, Notch stimulated preconditioning in vitro failed to enhance ECFC vasculogenesis in vivo. In contrast, in vivo co-implantation of ECFCs with OP9-Delta-like 1 stromal cells that constitutively expressed the Notch ligand delta-like 1 resulted in enhanced Notch activated ECFC-derived increased vessel density and enlarged vessel area in vivo, an effect not induced by OP9 control stromal implantation. RESULTS: This Notch activation was associated with diminished apoptosis in the exposed ECFC. CONCLUSIONS: We conclude that Notch pathway activation in ECFC in vivo via co-implanted stromal cells expressing delta-like 1 promotes vasculogenesis and augments blood vessel formation via diminishing apoptosis of the implanted ECFC