High‐pressure (HP) metagreywacke from the Namche Barwa Complex, Eastern Himalayan Syntaxis (EHS), consists of garnet, biotite, plagioclase, quartz, rutile and ilmenite with or without K‐feldspar, ...sillimanite, cordierite, spinel and orthopyroxene. Two types of metagreywacke are recognized: medium‐temperature (MT) and high‐temperature (HT) types. Garnet in the MT metagreywacke shows significant growth zoning and contains lower MgO than the weakly zoned garnet in the HT metagreywacke. Petrographic observations and phase equilibria modelling for four representative samples indicate that both types of metagreywacke experienced clockwise P–T paths subdivided into three stages: stage I is the pre‐peak prograde to pressure peak (Pmax) stage characterized by progressive increase in P–T conditions. The Pmax conditions are estimated using the garnet composition with maximum CaO, being 12.5–13.5 kbar and 685–725 °C for the MT metagreywacke, and 15–16 kbar and 825–835 °C for the HT one. Stage II is the post‐Pmax decompression with heating or near‐isothermal to Tmax stage and the Tmax conditions, constrained using the garnet compositions with maximum MgO, are 11 kbar and 760 °C for the MT metagreywacke, and ~12 kbar and 830–845 °C for the HT one. The modelled mineral assemblages at Tmax are garnet + biotite + K‐feldspar + rutile + plagioclase ± ilmenite in the presence of melt for both types of metagreywacke, consistent with the petrographic observations. Stage III is the post‐Tmax retrograde metamorphism, characterized by decompression and cooling. The modelling suggests that the melts with high Na/K ratios (1.7–5.2) have been produced during stages I and II, which could be responsible for the formation of sodium‐rich leucogranites. This study and previous results indicate that the Higher Himalayan Crystallines in the EHS consist of MT–HP and HT–HP metamorphic units separated by a speculated tectonic contact. Petrological and structural discontinuities within the EHS cannot be easily interpreted with ‘tectonic aneurysm’ model.
A full‐length cDNA encoding Cydia pomonella pheromone binding protein 1 (CpomPBP1) was cloned and characterized. CpomPBP1, possessing the typical characteristics of lepidopteran odorant binding ...proteins, was detected to be specifically expressed in the antennae of male and female moths at the mRNA and protein level. Soluble recombinant CpomPBP1 was subjected to in vitro binding to analyse its binding properties and to search for potentially active semiochemicals. A competitive binding assay showed that three 12‐carbon ligands, codlemone, 1‐dodecanol and E,E‐2,4‐dodecadienal, were able to bind to CpomPBP1 in decreasing order of affinity. Moreover, unlike the wild‐type CpomPBP1, the C‐terminus truncated CpomPBP1 exhibited high affinity to ligands even in an acidic environment, suggesting that the C‐terminus plays a role in preventing ligands from binding to CpomPBP1 in a lower pH environment.
Paleoanthropologists and vertebrate paleontologists have for decades debated the etiology of tooth wear and its implications for understanding the diets of human ancestors and other extinct mammals. ...The debate has recently taken a twist, calling into question the efficacy of dental microwear to reveal diet. Some argue that endogenous abrasives in plants (opal phytoliths) are too soft to abrade enamel, and that tooth wear is caused principally by exogenous quartz grit on food. If so, variation in microwear among fossil species may relate more to habitat than diet. This has important implications for paleobiologists because microwear is a common proxy for diets of fossil species. Here we reexamine the notion that particles softer than enamel (e.g., silica phytoliths) do not wear teeth. We scored human enamel using a microfabrication instrument fitted with soft particles (aluminum and brass spheres) and an atomic force microscope (AFM) fitted with silica particles under fixed normal loads, sliding speeds, and spans. Resulting damage was measured by AFM, and morphology and composition of debris were determined by scanning electron microscopy with energy-dispersive X-ray spectroscopy. Enamel chips removed from the surface demonstrate that softer particles produce wear under conditions mimicking chewing. Previous models posited that such particles rub enamel and create ridges alongside indentations without tissue removal. We propose that although these models hold for deformable metal surfaces, enamel works differently. Hydroxyapatite crystallites are “glued” together by proteins, and tissue removal requires only that contact pressure be sufficient to break the bonds holding enamel together.
We present observations of a quasi-periodic fast-propagating (QFP) magnetosonic wave on 23 April 2012, with high-resolution observations taken by the
Atmospheric Imaging Assembly
onboard the
Solar ...Dynamics Observatory
. Three minutes after the start of a C2.0 flare, wave trains were first observed along an open divergent loop system in 171 Å observations at a distance of 150 Mm from the footpoint of the guiding loop system and with a speed of 689 km s
−1
, then they appeared in 193 Å observations after their interaction with a perpendicular, underlaying loop system on the path; in the meantime; their speed decelerated to 343 km s
−1
within a short time. The sudden deceleration of the wave trains and their appearance in 193 Å observations are interpreted through a geometric effect and the density increase of the guiding loop system, respectively. We find that the wave trains have a common period of 80 seconds with the flare. In addition, a few low frequencies are also identified in the QFP wave. We propose that the generation of the period of 80 seconds was caused by the periodic releasing of energy bursts through some nonlinear processes in magnetic reconnection, while the low frequencies were possibly the leakage of pressure-driven oscillations from the photosphere or chromosphere, which could be an important source for driving coronal QFP waves. Our results also indicate that the properties of the guiding magnetic structure, such as the distributions of magnetic field and density as well as geometry, are crucial for modulating the propagation behaviors of QFP waves.
To quantify the total, direct and indirect impacts of fireworks individually, size-resolved PM samples were collected before, during and after a Chinese folk festival (Chinese New Year) in a megacity ...in China. Through chemical analysis and morphological characterisation, a strong influence of fireworks on the physicochemical characteristics of PM10 and PM2.5 was observed. The concentrations of many species exhibited an increasing trend during the heavy-firework period, especially for K+ , Mg2+ and Cr; the results of the non-sea-salt ions demonstrated an anthropogenic influence on K+ and Mg2+ . Then, source apportionment was conducted by receptor models and peak analysis (PA). The total influence of the fireworks was quantified by positive matrix factorisation (PMF), showing that the fireworks contributed higher fractions (23.40% for PM10 and 29.66% for PM2.5 ) during the heavy-firework period than during the light-firework period (4.28% for PM10 and 7.18% for PM2.5 ). The profiles of the total fireworks obtained by two independent methods (PMF and peak analysis) were consistent, with higher abundances of K+ , Al, Si, Ca and organic carbon (OC). Finally, the individual contributions of the direct and indirect impacts of fireworks were quantified by chemical mass balance (CMB). The percentage contributions of resuspended dust, biomass combustion and direct fireworks were 36.8 ± 8.37%, 14.1 ± 2.82% and 44.4 ± 8.26%, respectively, for PM10 and 34.9 ± 4.19%, 16.6 ± 3.05% and 52.5 ± 9.69%, respectively, for PM2.5 , in terms of the total fireworks. The quantification of the total, direct and indirect impacts of fireworks in the ambient PM gives a original contribution for understanding the physicochemical characteristics and mechanisms of such high-intensity anthropogenic activities.
A most general density-matrix formalism is presented to investigate linear polarization of characteristic lines following electron-impact excitation of atoms or ions with arbitrary nuclear spin, ...which can account for depolarization of energy levels and multipole mixing of radiation fields. It is then applied to the linear polarization of the Kα1 line radiated from heliumlike ions with nuclear spin I=1/2. As an example, detailed calculations are performed for 81207Tl79+ ions using the multi-configurational Dirac-Fock method and relativistic distorted-wave theory. It is found that the effect of the hyperfine interaction on the linear polarization depends dominantly on impact electron energy. For low impact energies close to the excitation threshold, the hyperfine interaction results in an enhancement of the linear polarization, especially for those photons emitted perpendicularly to the impact electron beam. In contrast, such a hyperfine-induced effect diminishes quickly with increasing impact energy and vanishes at medium and high energies, which is very different from the results for the case of radiative electron capture (Surzhykov et al 2013 Phys. Rev. A 87 052507). The present study is experimentally accessible at both electron-beam ion traps and ion storage rings and, thus, accurate Kα1 polarization measurements at low energies can be utilized to probe the hyperfine interaction in highly charged few-electron ions.
•High foaming capacity of lentil legumin-like protein and long life foams were obtained at pH 5.0 and 7.0.•Kinetic suggests that foaming stability is closely related to surface protein ...conformation.•Interfacial layer strength is linked to size, conformation and solubility/hydrophobicity balance.
The capacity of a protein to form and stabilize foams and emulsions depends on its structural characteristics and its physicochemical properties. The structural properties of lentil legumin-like protein including molecular weight, hydrodynamic size, surface charge and hydrophobicity, and conformation were studied in relation to its air–water interfacial behaviors. Kinetics study suggested that the foaming stability was closely related to the surface conformation of the protein that strongly affected adsorption and re-organization of the protein layer at the air–water interface. Foams prepared at neutral pH showed dense and strong networks at the interface, where combination of the α-helix secondary structure, medium hydrodynamic molecular size, and balance between solubility/hydrophobicity all contributed to the formation of such strong protein network at the interface. At pH 5.0, the protein formed a dense and thick network composed of randomly aggregated protein particles at the air–water interface. Whereas at pH 3.0, the unordered structure increased intra-protein flexibility producing a less compact and relaxed interface that reduces elasticity modulus with time and reduced foam resistance against collapse. This research revealed that lentil legumin-like protein could form long-life foams at mild acidic and neutral pH. The potential for use of lentil protein as a novel foaming plant-based stabilizer is demonstrated in food and non-food applications where stable, long-life foams are required.
Within the framework of the density matrix theory, the angular distribution of the characteristic magnetic-quadrupole line
1
s
2
p
3
P
2
→
1
s
2
1
S
0
following electron-impact excitation of ...heliumlike thallium ions with nuclear spin
I
=
1
/
2
has been investigated by using the multiconfigurational Dirac–Hartree–Fock method and the relativistic distorted-wave theory. Special attention has been paid to exploring the question of how the angular distribution of the characteristic line is affected by the multipole interference between the dominant magnetic-quadrupole and hyperfine-induced electric-dipole decay channels of its hyperfine-structure-resolved component
1
s
2
p
3
P
2
,
F
=
3
/
2
→
1
s
2
1
S
0
,
F
0
=
1
/
2
. To this aim, detailed calculations are performed for spin-1/2
81
187
Tl
79
+
and
81
207
Tl
79
+
ions with (relatively) large nuclear magnetic dipole moment. It is found that the hyperfine-induced multipole interference contributes to making the angular distribution of the magnetic-quadrupole line
1
s
2
p
3
P
2
→
1
s
2
1
S
0
less anisotropic for all the impact electron energies considered, although at any given impact energy its angular emission pattern remains always qualitatively consistent with each other for both the two cases without and with the interference contribution included. Moreover, for the case with the interference considered the angular distribution of the magnetic-quadrupole line is found to be sensitive to the nuclear magnetic dipole moment of the spin-1/2 ions, especially at low impact electron energies.
Graphic Abstract
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