Effects of non-universal large scales on conditional structure functions in turbulence

We report measurements of conditional Eulerian and Lagrangian structure functions in order to assess the effects of non-universal properties of the large scales on the small scales in turbulence. We study a 1m $\times$ 1m $\times$ 1.5m flow between oscillating grids which produces $R_\lambda=285$ while containing regions of nearly homogeneous and highly inhomogeneous turbulence. Large data sets of three-dimensional tracer particle velocities have been collected using stereoscopic high speed cameras with real-time image compression technology. Eulerian and Lagrangian structure functions are measured in both homogeneous and inhomogeneous regions of the flow. We condition the structure functions on the instantaneous large scale velocity or on the grid phase. At all scales, the structure functions depend strongly on the large scale velocity, but are independent of the grid phase. We see clear signatures of inhomogeneity near the oscillating grids, but even in the homogeneous region in the center we see a surprisingly strong dependence on the large scale velocity that remains at all scales. Previous work has shown that similar correlations extend to very high Reynolds numbers. Comprehensive measurements of these effects in a laboratory flow provide a powerful tool for assessing the effects of shear, inhomogeneity and intermittency of the large scales on the small scales in turbulence

Effects of Timber Harvesting and Plantation Development on Cavity-nesting Birds in New Brunswick

We studied the abundance of cavity-nesting birds in forestry-related habitats in a region of Acadian forest in New Brunswick. We examined five reference stands of natural forest, a chronosequence of conifer plantations up to 19 years old (the oldest in the study area), two selectively harvested stands, and a 30-year-old naturally regenerated clear-cut. The species richness and abundance of cavity-nesting birds were higher in reference forest (average 10.0 species per stand; 5.3 territories per 10 ha) than in plantations (2.3/stand; 1.0/10 ha), selectively harvested stands (7.0/stand; 3.8/10 ha), or the naturally regenerated clear-cut (5.0/stand; 2.5/10 ha). A cluster analysis segregated the “community” of cavity-nesting birds of natural forest from those of other treatments. Of the various harvested stands and plantations, five with a relatively large number of residual snags clustered similarly in the cluster analysis, while those with no or very few snags also clustered together. We used arrays of nest boxes (12 per stand) to examine whether the availability of cavities was limiting the use of habitats otherwise suitable for foraging by cavity-dependent species. Nest-box use for nesting and roosting was much higher in the seven plantations examined (average 4.0/10 ha for nesting and 2.9/10 ha for roosting) than in three reference stands (each 0.3/10 ha), suggesting that the plantations were deficient in this critical-habitat element. Our results suggest that certain mitigations, such as leaving residual snags and living cavity-trees, would help maintain populations of some cavity-dependent birds in clear-cuts and plantations. However, some cavity-dependent species might not be accommodated by these mitigations and are potentially at risk in intensively managed areas, unless landscape-scale management plans ensure the survival of sufficient areas of older mixed-wood forest

High surface area, low weight composite nickel fiber electrodes

The energy density and power density of light weight aerospace batteries utilizing the nickel oxide electrode are often limited by the microstructures of both the collector and the resulting active deposit in/on the collector. Heretofore, these two microstructures were intimately linked to one another by the materials used to prepare the collector grid as well as the methods and conditions used to deposit the active material. Significant weight and performance advantages were demonstrated by Britton and Reid at NASA-LeRC using FIBREX nickel mats of ca. 28-32 microns diameter. Work in our laboratory investigated the potential performance advantages offered by nickel fiber composite electrodes containing a mixture of fibers as small as 2 microns diameter (Available from Memtec America Corporation). These electrode collectors possess in excess of an order of magnitude more surface area per gram of collector than FIBREX nickel. The increase in surface area of the collector roughly translates into an order of magnitude thinner layer of active material. Performance data and advantages of these thin layer structures are presented. Attributes and limitations of their electrode microstructure to independently control void volume, pore structure of the Ni(OH)2 deposition, and resulting electrical properties are discussed

Mutations in gfpt1 and skiv2l2 Cause Distinct Stage-Specific Defects in Larval Melanocyte Regeneration in Zebrafish

The establishment of a single cell type regeneration paradigm in the zebrafish provides an opportunity to investigate the genetic mechanisms specific to regeneration processes. We previously demonstrated that regeneration melanocytes arise from cell division of the otherwise quiescent melanocyte precursors following larval melanocyte ablation with a small molecule, MoTP. The ease of ablating melanocytes by MoTP allows us to conduct a forward genetic screen for mechanisms specific to regeneration from such precursors or stem cells. Here, we reported the identification of two mutants, earthaj23e1 and juliej24e1 from a melanocyte ablation screen. Both mutants develop normal larval melanocytes, but upon melanocyte ablation, each mutation results in a distinct stage-specific defect in melanocyte regeneration. Positional cloning reveals that the earthaj23e1 mutation is a nonsense mutation in gfpt1 (glutamine:fructose-6-phosphate aminotransferase 1), the rate-limiting enzyme in glucosamine-6-phosphate biosynthesis. Our analyses reveal that a mutation in gfpt1 specifically affects melanocyte differentiation (marked by melanin production) at a late stage during regeneration and that gfpt1 acts cell autonomously in melanocytes to promote ontogenetic melanocyte darkening. We identified that the juliej24e1 mutation is a splice-site mutation in skiv2l2 (superkiller viralicidic activity 2-like 2), a predicted DEAD-box RNA helicase. Our in situ analysis reveals that the mutation in skiv2l2 causes defects in cell proliferation, suggesting that skiv2l2 plays a role in regulating melanoblast proliferation during early stages of melanocyte regeneration. This finding is consistent with previously described role for cell division during larval melanocyte regeneration. The analyses of these mutants reveal their stage-specific roles in melanocyte regeneration. Interestingly, these mutants identify regeneration-specific functions not only in early stages of the regeneration process, but also in late stages of differentiation of the regenerating melanocyte. We suggest that mechanisms of regeneration identified in this mutant screen may reveal fundamental differences between the mechanisms that establish differentiated cells during embryogenesis, and those involved in larval or adult growth

Five Planets Orbiting 55 Cancri

We report 18 years of Doppler shift measurements of a nearby star, 55 Cancri, that exhibit strong evidence for five orbiting planets. The four previously reported planets are strongly confirmed here. A fifth planet is presented, with an apparent orbital period of 260 days, placing it 0.78 AU from the star in the large empty zone between two other planets. The velocity wobble amplitude of 4.9 \ms implies a minimum planet mass \msini = 45.7 \mearthe. The orbital eccentricity is consistent with a circular orbit, but modest eccentricity solutions give similar \chisq fits. All five planets reside in low eccentricity orbits, four having eccentricities under 0.1. The outermost planet orbits 5.8 AU from the star and has a minimum mass, \msini = 3.8 \mjupe, making it more massive than the inner four planets combined. Its orbital distance is the largest for an exoplanet with a well defined orbit. The innermost planet has a semi-major axis of only 0.038 AU and has a minimum mass, \msinie, of only 10.8 \mearthe, one of the lowest mass exoplanets known. The five known planets within 6 AU define a {\em minimum mass protoplanetary nebula} to compare with the classical minimum mass solar nebula. Numerical N-body simulations show this system of five planets to be dynamically stable and show that the planets with periods of 14.65 and 44.3 d are not in a mean-motion resonance. Millimagnitude photometry during 11 years reveals no brightness variations at any of the radial velocity periods, providing support for their interpretation as planetary.Comment: accepted to Ap

The N2K Consortium. I. A Hot Saturn Planet Orbiting HD 88133

The N2K ("next 2000") consortium is carrying out a distributed observing campaign with the Keck, Magellan, and Subaru telescopes, as well as the automatic photometric telescopes of Fairborn Observatory, in order to search for short-period gas giant planets around metal-rich stars. We have established a reservoir of more than 14,000 main-sequence and subgiant stars closer than 110 pc, brighter than V = 10.5, and with 0.4 0.1 dex for this survey. We outline the strategy and report the detection of a planet orbiting the metal-rich G5 IV star HD 88133 with a period of 3.41 days, semivelocity amplitude K = 35.7 m s^(-1), and M sin i = 0.29M_J. Photometric observations reveal that HD 88133 is constant on the 3.415 day radial velocity period to a limit of 0.0005 mag. Despite a transit probability of 19.5%, our photometry rules out the shallow transits predicted by the large stellar radius

Five New Extrasolar Planets

We report multiple Doppler measurements of five nearby FGK main-sequence stars and subgiants obtained during the past 4-6 yr at the Keck Observatory. These stars, namely, HD 183263, HD 117207, HD 188015, HD 45350, and HD 99492, all exhibit coherent variations in their Doppler shifts consistent with a planet in Keplerian motion. The five new planets occupy known realms of planetary parameter space, including a wide range of orbital eccentricities, e = 0-0.78, and semimajor axes, 0.1-3.8 AU, that provide further statistical information about the true distributions of various properties of planetary systems. One of the planets, HD 99492b, has a low minimum mass of 0.112M_(Jup) = 36M_(Earth). Four of the five planets orbit beyond 1 AU. We describe two quantitative tests of the false alarm probability for Keplerian interpretations of measured velocities. The more robust of these involves Monte Carlo realizations of scrambled velocities as a proxy for noise. Keplerian orbital fits to that "noise" yield the distribution of χ^2_v to compare with χ^2_v from the original (unscrambled) velocities. We establish a 1% false alarm probability as the criterion for candidate planets. All five of these planet-bearing stars are metal-rich, with [Fe/H] > +0.27, reinforcing the strong correlation between planet occurrence and metallicity. From the full sample of 1330 stars monitored at Keck, Lick, and the Anglo-Australian Telescope, the shortest orbital period for any planet is 2.64 days, showing that shorter periods occur less frequently than 0.1% in the solar neighborhood. Photometric observations were acquired for four of the five host stars with an automatic telescope at Fairborn Observatory. The lack of brightness variations in phase with the radial velocities supports planetary-reflex motion as the cause of the velocity variations. No transits were observed, but their occurrence is not ruled out by our observations

Five New Multicomponent Planetary Systems

We report Doppler measurements for six nearby G- and K-type main-sequence stars that show multiple low-mass companions, at least one of which has planetary mass. One system has three planets, the fourth triple-planet system known around a normal star, and another has an extremely low minimum mass of 18 M_⊕. HD 128311 (K0 V) has two planets (one previously known) with minimum masses (M sin i) of 2.18M_J and 3.21M_J and orbital periods of 1.26 and 2.54 yr, suggesting a possible 2 : 1 resonance. For HD 108874 (G5 V), the velocities reveal two planets (one previously known) having minimum masses and periods of (M sin i_b = 1.36M_J, P_b = 1.08 yr) and (M sin i_c = 1.02M_J, P_c = 4.4 yr). HD 50499 (G1 V) has a planet with P = 6.8 yr and M sin i = 1.7M_J, and the velocity residuals exhibit a trend of -4.8 m s^(-1) yr^(-1), indicating a more distant companion with P > 10 yr and minimum mass of 2M_J. HD 37124 (G4 IV-V) has three planets, one having M sin i = 0.61M_J and P = 154.5 days, as previously known. We find two plausible triple-planet models that fit the data, both having a second planet near P = 840 days, with the more likely model having its third planet in a 6 yr orbit and the other one in a 29 day orbit. For HD 190360, we confirm the planet having P = 7.9 yr and M sin i = 1.5M_J as found by the Geneva team, but we find a distinctly noncircular orbit with e = 0.36 ± 0.03, rendering this not an analog of Jupiter as had been reported. Our velocities also reveal a second planet with P = 17.1 days and M sin i = 18.1 M_⊕. HD 217107 (G8 IV) has a previously known "hot Jupiter" with M sin i = 1.4M_J and P = 7.13 days, and we confirm its high eccentricity, e = 0.13. The velocity residuals reveal an outer companion in an eccentric orbit, having minimum mass of M sin i > 2M_J, eccentricity e ~ 0.5, and a period P > 8 yr, implying a semimajor axis α > 4 AU and providing an opportunity for direct detection. We have obtained high-precision photometry of five of the six planetary host stars with three of the automated telescopes at Fairborn Observatory. We can rule out significant brightness variations in phase with the radial velocities in most cases, thus supporting planetary reflex motion as the cause of the velocity variations. Transits are ruled out to very shallow limits for HD 217107 and are also shown to be unlikely for the prospective inner planets of the HD 37124 and HD 108874 systems. HD 128311 is photometrically variable with an amplitude of 0.03 mag and a period of 11.53 days, which is much shorter than the orbital periods of its two planetary companions. This rotation period explains the origin of periodic velocity residuals to the two-planet model of this star. All of the planetary systems here would be further constrained with astrometry by the Space Interferometry Mission

Phase II Trial of Dasatinib for Patients with Acquired Resistance to Treatment with the Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors Erlotinib or Gefitinib

Introduction:Dual inhibition of SRC- and EGFR-dependent pathways may overcome acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) for patients with lung adenocarcinoma with EGFR mutations. The SRC inhibitor dasatinib demonstrates antitumor activity in gefitinib-resistant cells lines and xenografts. Dasatinib is tolerable for patients with advanced non-small cell lung cancer, and in combination with erlotinib.Methods:We conducted this phase II study of dasatinib 70 mg twice daily in patients with EGFR-mutant lung adenocarcinoma and acquired resistance to EGFR-TKIs. After a protocol amendment based on evolving data about both drugs, patients received dasatinib at a dose of 100 mg daily with continued erlotinib after developing acquired resistance. Enrolled patients either harbored an activating mutation in EGFR or experienced clinical benefit with single-agent erlotinib or gefitinib, followed by RECIST documented progression while being treated with an EGFR-TKI.Results:Twenty-one patients were enrolled, 9 under the original trial design and 12 after the protocol amendments. We observed no complete or partial responses (0% observed rate, 95% confidence interval: 0–18%). The median time to progression was 0.5 months (range, 0.2–1.8 months) in patients treated with dasatinib and 0.9 months (range, 0.4–5 months) for patients treated with dasatinib and erlotinib in combination. Pleural effusions and dyspnea were frequent toxicities.Conclusions:Dasatinib has no activity in patients with EGFR-mutant lung adenocarcinoma with acquired resistance to erlotinib and gefitinib

Migratory and winter activity of bats in Yellowstone National Park

A substantial body of work exists describing timing of migration and hibernation among bats in eastern North America, but less is known about these events among bats inhabiting the Rocky Mountain region. Yellowstone National Park is a geothermally influenced landscape comprised of diverse habitats, creating the opportunity for unique behaviors to develop among local bat populations. We identified the timing of migration for the local bat community and determined if bats overwinter in Yellowstone. To accomplish this, we radiotracked 7 little brown myotis (Myotis lucifugus), 5 western long-eared myotis (M. evotis), 4 big brown bats (Eptesicus fuscus), 4 silver-haired bats (Lasionycteris noctivagans), and 1 western small-footed myotis (M. ciliolabrum) from August to September 2010 and September to October 2011. We also used acoustic detectors to record bat activity from November through April 2011–2014 and sampled abundance of nocturnal insects using black-light traps from 2011 to 2012. Although availability of insects declined rapidly during August and afterward, several bat species remained active throughout autumn and winter. Bat activity was recorded during all months, even during periods of extreme cold. Radiotagged big brown bats, little brown myotis, and western small-footed myotis remained active in the study area throughout October, after the 1st snowfall of the season. While data for activity patterns in late autumn and winter prevented an estimation of the onset of hibernation, spring emergence occurred in April despite persistence of winter conditions. These data provide insights into the migration and hibernation strategies of bat populations in the Rocky Mountains and highlight gaps in our understanding of seasonal changes in these species