During the 2012 Deep Convective Clouds and Chemistry
(DC3) experiment the National Science Foundation/National Center for
Atmospheric Research Gulfstream V (GV) aircraft sampled the upper anvils of
...two storms that developed in eastern Colorado on 6 June 2012. A cloud
particle imager (CPI) mounted on the GV aircraft recorded images of ice
crystals at altitudes of 12.0 to 12.4 km and temperatures (T) from −61 to −55 ∘C.
A total of 22 393 CPI crystal images were analyzed, all with maximum
dimension (Dmax)<433 µm and with an average Dmax of
80.7±45.4 µm. The occurrence of well-defined pristine crystals
(e.g., columns and plates) was less than 0.04 % by number. Single frozen
droplets and frozen droplet aggregates (FDAs) were the dominant habits with
fractions of 73.0 % (by number) and 46.3 % (by projected area),
respectively. The relative frequency of occurrence of single frozen droplets
and FDAs depended on temperature and position within the anvil cloud. A new algorithm that uses the circle Hough transform technique was developed
to automatically identify the number, size, and relative position of element
frozen droplets within FDAs. Of the FDAs, 42.0 % had two element frozen
droplets with an average of 4.7±5.0 element frozen droplets. The
frequency of occurrence gradually decreased with the number of element frozen
droplets. Based on the number, size, and relative position of the element
frozen droplets within the FDAs, possible three-dimensional (3-D)
realizations of FDAs were generated and characterized by two different shape
parameters, the aggregation index (AI) and the fractal dimension (Df),
that describe 3-D shapes and link to scattering properties with an
assumption of spherical shape of element frozen droplets. The AI of FDAs
decreased with an increase in the number of element frozen droplets, with
larger FDAs with more element frozen droplets having more compact shapes.
The Df of FDAs was about 1.20–1.43 smaller than that of black carbon
(BC) aggregates (1.53–1.85) determined in previous studies. Such a smaller
Df of FDAs indicates that FDAs have more linear chain-like branched
shapes than the compact shapes of BC aggregates. Determined morphological
characteristics of FDAs along with the proposed reconstructed 3-D
representations of FDAs in this study have important implications for
improving the calculations of the microphysical (e.g., fall velocity) and radiative
(e.g., asymmetry parameter) properties of ice crystals in upper anvil
clouds.
Detection of copy number variation (CNV) in DNA has recently become an important method for understanding the pathogenesis of cancer. While existing algorithms for extracting CNV from microarray data ...have worked reasonably well, the trend towards ever larger sample sizes and higher resolution microarrays has vastly increased the challenges they face. Here, we present Segmentation analysis of DNA (SAD), a clustering algorithm constructed with a strategy in which all operational decisions are based on simple and rigorous applications of statistical principles, measurement theory and precise mathematical relations. Compared with existing packages, SAD is simpler in formulation, more user friendly, much faster and less thirsty for memory, offers higher accuracy and supplies quantitative statistics for its predictions. Unique among such algorithms, SAD's running time scales linearly with array size; on a typical modern notebook, it completes high-quality CNV analyses for a 250 thousand-probe array in ∼1 s and a 1.8 million-probe array in ∼8 s.
Hesperetin-5,7,3'-
-trimethylether (HTME), a synthetic liposoluble hesperetin, has been reported to be a dual phosphodiesterase (PDE)3/4 inhibitor. We investigated its inhibitory effects on ...methacholine (MCh)-induced airway hyperresponsiveness (AHR) and its potential for treating atypical asthma and COPD.
FlexiVent system was used to determine AHR in ovalbumin (OVA) sensitized and challenged mice. Determination of cytokines was performed by using mouse T helper (Th)1/Th2 cytokine CBA kits, and of total immunoglobulin (Ig)E and OVA-specific IgE using ELISA kits. The number of inflammatory cells was counted using a hemocytometer. Xylazine/ketamine-induced anesthesia was to assess nausea, vomiting, and gastric hypersecretion in these mice.
HTME dually and competitively inhibited PDE3/4 activities in the Lineweaver-Burk analysis. HTME (30 and 100 μmol/kg) dose-dependently and significantly decreased the airway resistance (R
) and increased lung dynamic compliance (C
) values induced by MCh. It significantly suppressed numbers of total inflammatory cells and neutrophils, and levels of cytokines in bronchoalveolar lavage fluid (BALF). HTME dose-dependently and significantly inhibited total and OVA-specific IgE levels in the BALF and serum. However, HTME did not influence xylazine/ketamine-induced anesthesia.
HTME exerted anti-inflammatory and bronchodilator effects and may be useful in treating chronic obstructive pulmonary disease and allergic atypical asthma with no gastrointestinal side effects.
We present an efficient vertical InGaN light-emitting diode (LED) in which the proposed vertical LEDs were fabricated with patterned sapphire substrates (PSS) using thinning techniques. After the ...thinning of sapphire substrate, selective dry etching process was performed on the remainder sapphire layer to expose the n-GaN contact layer instead of removing the sapphire substrate using the laser lift-off technique. These processes feature the LEDs with a sapphire-face-up structure and vertical conduction property. The PSS was adopted as a growth substrate to mitigate the light-guided effect, and thereby increase the light-extraction efficiency. Compared with conventional lateral GaN LEDs grown on PSS, the proposed vertical LEDs exhibit a higher light output power and less power degradation at a high driving current. This could be attributed to the fact that the vertical LEDs behave in a manner similar to flip-chip GaN/sapphire LEDs with excellent heat conduction.
We investigate the aerodynamic performance of the dragonfly wing, which has cross-sectional corrugation, via a static 2-dimensional unsteady simulation. Computational conditions are
Re=150, 1400, and ...10,000 with angles of attack ranging from 0° to 40°. From the computational results, lift coefficients are increased by the wing corrugation at all Reynolds number. However, the corrugation has little influence on the drag coefficients. The flows such as vortex in the valley of corrugation and near the edge of the corrugation are locally different from those of an elliptic wing. However, such local flows have little influence on the time averaged wing performance. From the numerical experiment presented in this study, it is determined that suction side corrugations of the wing have very little influence on increase of the lift coefficient at a positive angle of attack.
As part of the Vertical Transport in the Global Ocean (VERTIGO) program, we collected and analyzed sinking particles using sediment traps at three depths in the oceanic mesopelagic zone and at two ...biogeochemically contrasting sites (N. Central Pacific at ALOHA; N. Pacific Western Subarctic Gyre at K2). In this paper, we present the results of minor and trace element determinations made on these samples.
Minor and trace elements in the sinking material showed 2 trends in flux with depth: increasing and constant. The sinking particulate phase of some elements (Al, Fe, Mn) was dominated by material of lithogenic origin and exhibited flux that was constant with depth and consistent with eolian dust inputs (ALOHA), or increasing in flux with depth as a result of lateral inputs from a shelf (K2). This shelf-derived material also appears to have been confined to very small particles, whose inherent sinking rates are slow, and residence time within the mesopelagic “twilight zone” would be consequently long. Furthermore, the flux of this material did not change with substantial changes in the rain of biogenic material from the surface (K2), suggesting mechanistic decoupling from the flux of organic carbon and macronutrients.
Micronutrient (Fe, Co, Zn and Cu) fluxes examined in a 1-D mass balance suggest widely differing sources and sinks in the water column as well as impacts from biological uptake and regeneration. For example, total Fe fluxes into and out of the euphotic zone appeared to be dominated by lithogenic material and far exceed biological requirements. The export flux of Fe, however, appeared to be balanced by the eolian input of soluble Fe. For Zn and Cu, the situation is reversed, with atmospheric inputs insufficient to support fluxes, and the cycling therefore dominated by the draw down of an internal pool. For Co, the situation lies in between, with important, but ultimately insufficient atmospheric inputs.
The large solar storms in October–November 2003 caused solar proton events (SPEs) at the Earth and impacted the middle atmospheric polar cap regions. Although occurring near the end of the maximum of ...solar cycle 23, the fourth largest period of SPEs measured in the past 40 years happened 28–31 October 2003. The highly energetic protons associated with the SPEs produced ionizations, excitations, dissociations, and dissociative ionizations of the background constituents, which led to the production of odd hydrogen (HOx) and odd nitrogen (NOy). NOx (NO + NO2) was observed by the UARS HALOE instrument to increase over 20 ppbv throughout the Southern Hemisphere polar lower mesosphere. The NOAA 16 SBUV/2 instrument measured a short‐term ozone depletion of 40% in the Southern Hemisphere polar lower mesosphere, probably a result of the HOx increases. SBUV/2 observations showed ozone depletions of 5–8% in the southern polar upper stratosphere lasting days beyond the events, most likely a result of the NOy enhancements. Longer‐term Northern Hemisphere polar total ozone decreases of >0.5% were predicted to last for over 8 months past the events with the Goddard Space Flight Center two‐dimensional model. Although the production of NOy constituents is the same in both hemispheres, the NOy constituents have a much larger impact in the northern than the southern polar latitudes because of the seasonal differences between the two hemispheres. These observations and model computations illustrate the substantial impact of solar protons on the polar neutral middle atmosphere.
Lead has long been of concern for its toxicity, impairment of neurobehavioral and cognitive development, and electrophysiological deficits in children, even at levels less than 10μg/dL. The present ...study was conducted to elucidate the extent of cord blood lead level decline in the Taipei area from 1985 to 2002 and to explore the factors affecting the cord blood lead level after the cease of leaded gasoline use. In the current study period of 2001–2002, 184 of 1310 newborns delivered in the Taipei Municipal Women and Children Hospital between September 2001 and August 2002 were eligible and randomly selected to participate in this study. Neither of their parents had an occupational lead exposure history. At each delivery, a sample of 5–10mL umbilical cord blood was collected for lead determination by graphite furnace atomic absorption spectrometry. The cord blood lead level of the newborns in the current study period averaged 2.35±1.12μg/dL. Together with the cord blood lead averages of 7.48±2.25 and 3.28±1.52μg/dL obtained from two previous surveys conducted in 1985–1987 and 1990–1992, respectively, the cord blood lead level was significantly decreased (P<0.005). It is estimated that such a reduction in cord blood lead from 7.48 to 2.35μg/dL for each year's cohort of 260,000 newborns in Taiwan might benefit the economics, ranging from US$8.9 billion to US$12.1 billion by improving the worker productivity. For the time period from 1985 to 2002, there were consistent transition patterns among the yearly fluctuations of air lead level, leaded gasoline consumption, lead content in gasoline, estimated lead amount emitted from the consumed leaded gasoline, and average cord blood lead levels of the three respective study periods. Additionally, every 0.1-g/L reduction in lead content in gasoline might lead to a lowering of cord blood lead level by 1.78μg/dL. Furthermore, at low level of around 2μg/dL, a multiple regression analysis demonstrated that economic status was the most influential factor for cord blood lead variation (P=0.0061) while the maternal working month during her pregnancy was retained in the model with borderline effect (P=0.0625). After accounting for the effect of leaded gasoline on the cord blood lead level, future study to differentiate the primary contributors for the low-level cord blood lead variation around 1–2μg/dL is warranted.
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