4,789 research outputs found

    The cholesterol-hydroxyecdysone-vitellogenin pathway is involved in the longevity of trophocytes and oenocytes of queen honey bees (Apis mellifera)

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    International audienceAbstractTrophocytes and oenocytes in the abdomen of honey bees do not divide after eclosion; however, trophocytes and oenocytes of queen bees have a longer lifespan and maintain better cellular function than those of worker bees. To explore this phenomenon, we assayed the molecules involved in the cholesterol-hydroxyecdysone-vitellogenin (Vg) pathway in the trophocytes and oenocytes of young and old worker and queen bees. The results showed that Vg and cholesterol levels in hemolymph and cholesterol levels, 20-hydroxyecdysone (20E) levels, and the messenger RNA levels of cytochrome P450 314A1 20-hydroxylase (Cyp314A1), ecdysone receptor isoform A (EcR-A), ecdysone receptor isoform B1 (EcR-B1), ultraspiracle (USP), ecdysone-induced protein 74 (E74), ecdysone-induced protein 75 (E75), broad-complex (BR-C), Vg, and Vg receptor (VgR) in trophocytes and oenocytes were increased in queen bees compared with worker bees. These findings indicated that queen bees have higher expression of molecules in the cholesterol-hydroxyecdysone-Vg pathway than worker bees

    Economic Growth, Oil Consumption and Import Intensity: Factor Decomposition of Imported Crude Oil Model Approach

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    Taiwan became a member of the WTO in 2002. Trade is the engine of growth in Taiwan, accounting for nearly 96.41% of GDP in 2016. Taiwan's economy is highly export-oriented. On the other hand, Taiwan depends on imports for near 98 percent of its energy consumption. This paper analyzes the changes in the intensity of crude oil imports between 1981 and 2016. This research sets several main topics: i) Estimating the imported crude oil intensity of final demand for a quantity analysis. ii) Measure of imported crude oil intensity of final demand. iii) Factor decomposition model for the imported crude oil intensity of final demand. iv) The study could provide an understanding of the properties and production technologies of various industries. The result shows that imported goods intensity is the largest in the crude oil and gas sector. Changes in imported crude oil intensity factors mainly from domestic production structure and final demand structure. Keywords: Economic growth, Imported Crude Oil intensity, Factor Decomposition JEL Classifications: C51, F14, Q4

    GMC collisions as triggers of star formation – VIII. The core mass function

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    Compression in giant molecular cloud (GMC) collisions is a promising mechanism to trigger the formation of massive star clusters and OB associations. We simulate colliding and non-colliding magnetized GMCs and examine the properties of pre-stellar cores, selected from projected mass surface density maps, including after synthetic ALMA observations. We then examine core properties, including mass, size, density, velocity, velocity dispersion, temperature, and magnetic field strength. After 4 Myr, ∼1000 cores have formed in the GMC collision, and the high-mass end of the core mass function (CMF) can be fit by a power-law dN/dlogM ∝ M-α with α ≃ 0.7, i.e. relatively top heavy compared to a Salpeter mass function. Depending on how cores are identified, a break in the power law can appear around a few 710 M☉. The non-colliding GMCs form fewer cores with a CMF with α ≃ 0.8–1.2, i.e. closer to the Salpeter index. We compare the properties of these CMFs to those of several observed samples of cores. Considering other properties, cores formed from colliding clouds are typically warmer, have more disturbed internal kinematics, and are more likely to be gravitational unbound, than cores formed from non-colliding GMCs. The dynamical state of the protocluster of cores formed in the GMC–GMC collision is intrinsically subvirial but can appear to be supervirial if the total mass measurement is affected by observations that miss mass on large scales or at low densities

    On the Quality of Service of Cloud Gaming Systems

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    Estimation of Agricultural Groundwater Usage by Well Pumping Efficiency and Electric Consumption

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    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive

    Ring Characteristics and Compressive Strength of Japanese Cedar Trees Grown Under Different Silvicultural Treatments

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    The effects of different plantation spacings and thinning treatments on the ring characteristics, compressive strength, and dynamic modulus of elasticity (DMOE) of Japanese cedar (Cryptomeria japonica) trees were investigated. The results revealed that young trees of more-closely spaced plantations (3000 trees/ha) had higher wood density and compressive strength than those of more-widely spaced plantations (2200 trees/ha). Different (first and second) thinning treatments of the 2 initial spacings had little effect on ring characteristics or compressive strength. Overall, the average ring characteristics, compressive strength, and DMOE of 35-yr-old Japanese cedar at different plantation spacings and thinning treatments showed no statistically significant differences. The results suggest that using these silvicultural treatments with a longer rotation age will have no detrimental effects on the wood density, compressive strength, or DMOE

    Land Subsidence Caused by Groundwater Exploitation in Yunlin, Taiwan

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    Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchive

    Deuterium Chemodynamics of Massive Pre-Stellar Cores

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    High levels of deuterium fractionation of N2H+\rm N_2H^+ (i.e., DfracN2H+0.1\rm D_{frac}^{N_2H^+} \gtrsim 0.1) are often observed in pre-stellar cores (PSCs) and detection of N2D+\rm N_2D^+ is a promising method to identify elusive massive PSCs. However, the physical and chemical conditions required to reach such high levels of deuteration are still uncertain, as is the diagnostic utility of N2H+\rm N_2H^+ and N2D+\rm N_2D^+ observations of PSCs. We perform 3D magnetohydrodynamics simulations of a massive, turbulent, magnetised PSC, coupled with a sophisticated deuteration astrochemical network. Although the core has some magnetic/turbulent support, it collapses under gravity in about one freefall time, which marks the end of the simulations. Our fiducial model achieves relatively low DfracN2H+0.002\rm D_{frac}^{N_2H^+} \sim 0.002 during this time. We then investigate effects of initial ortho-para ratio of H2\rm H_2 (OPRH2\rm OPR^{H_2}), temperature, cosmic ray (CR) ionization rate, CO and N-species depletion factors and prior PSC chemical evolution. We find that high CR ionization rates and high depletion factors allow the simulated DfracN2H+\rm D_{frac}^{N_2H^+} and absolute abundances to match observational values within one freefall time. For OPRH2\rm OPR^{H_2}, while a lower initial value helps the growth of DfracN2H+\rm D_{frac}^{N_2H^+}, the spatial structure of deuteration is too widespread compared to observed systems. For an example model with elevated CR ionization rates and significant heavy element depletion, we then study the kinematic and dynamic properties of the core as traced by its N2D+\rm N_2D^+ emission. The core, undergoing quite rapid collapse, exhibits disturbed kinematics in its average velocity map. Still, because of magnetic support, the core often appears kinematically sub-virial based on its N2D+\rm N_2D^+ velocity dispersion.Comment: 25 pages, 20 figures, 2 tables, accepted for publication in MNRAS, comments welcom

    Effect of Process Parameters of CNT Containing Friction Powder on Flexural Properties and Friction Performance of Organic Brake Friction Materials

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    This research is to investigate the influences of carbon nanotube (CNT) containing friction powder prepared through different process parameters on flexural properties and friction performance of organic brake friction materials. Experimental results indicate significant influence on flexural property and friction performance of organic brake friction materials when the modified CNT/friction powders are adopted. Particularly for the specimens adopted the modified CNT/friction powders prepared through 2.0 M concentration of catalyst and 30% C2H2 show the highest flexural strength, better ductility and toughness, most stable friction coefficient, and lowest weight loss. However, too many amorphous carbon clusters and CNTs aggregation derived from higher concentration of catalyst and ratio of C2H2/N2 would cause poor formation of specimens and reduction of reinforcement effectiveness

    The Adaptor Protein SH2B3 (Lnk) Negatively Regulates Neurite Outgrowth of PC12 Cells and Cortical Neurons

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    SH2B adaptor protein family members (SH2B1-3) regulate various physiological responses through affecting signaling, gene expression, and cell adhesion. SH2B1 and SH2B2 were reported to enhance nerve growth factor (NGF)-induced neuronal differentiation in PC12 cells, a well-established neuronal model system. In contrast, SH2B3 was reported to inhibit cell proliferation during the development of immune system. No study so far addresses the role of SH2B3 in the nervous system. In this study, we provide evidence suggesting that SH2B3 is expressed in the cortex of embryonic rat brain. Overexpression of SH2B3 not only inhibits NGF-induced differentiation of PC12 cells but also reduces neurite outgrowth of primary cortical neurons. SH2B3 does so by repressing NGF-induced activation of PLCγ, MEK-ERK1/2 and PI3K-AKT pathways and the expression of Egr-1. SH2B3 is capable of binding to phosphorylated NGF receptor, TrkA, as well as SH2B1β. Our data further demonstrate that overexpression of SH2B3 reduces the interaction between SH2B1β and TrkA. Consistent with this finding, overexpressing the SH2 domain of SH2B3 is sufficient to inhibit NGF-induced neurite outgrowth. Together, our data demonstrate that SH2B3, unlike the other two family members, inhibits neuronal differentiation of PC12 cells and primary cortical neurons. Its inhibitory mechanism is likely through the competition of TrkA binding with the positive-acting SH2B1 and SH2B2
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