Nonlinear optical frequency conversion has been challenged to move down to the extreme ultraviolet and x-ray region. However, the extremely low signals have allowed researchers to only perform ...transmission experiments of the gas phase or ultrathin films. Here, we report second harmonic generation (SHG) of the reflected beam of a soft x-ray free-electron laser from a solid, which is enhanced by the resonant effect. The observation revealed that the double resonance condition can be met by absorption edges for transition metal oxides in the soft x-ray range, and this suggests that the resonant SHG technique can be applicable to a wide range of materials. We discuss the possibility of element-selective SHG spectroscopy measurements in the soft x-ray range.
Cardiovascular diseases (CVD) are major contributors to mortality and morbidity in South Asia. Chronic exposure to air pollution is an important risk factor for cardiovascular diseases, although the ...majority of studies to date have been conducted in developed countries. Both indoor and outdoor air pollution are growing problems in developing countries in South Asia yet the impact on rising rates of CVD in these regions has largely been ignored. We aimed to assess the evidence available regarding air pollution effects on CVD and CVD risk factors in lower income countries in South Asia. A literature search was conducted in PubMed and Web of Science. Our inclusion criteria included peer-reviewed, original, empirical articles published in English between the years 1990 and 2012, conducted in the World Bank South Asia region (Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan and Sri Lanka). This resulted in 30 articles. Nine articles met our inclusion criteria and were assessed for this systematic review. Most of the studies were cross-sectional and examined measured particulate matter effects on CVD outcomes and indicators. We observed a bias as nearly all of the studies were from India. Hypertension and CVD deaths were positively associated with higher particulate matter levels. Biomarkers of oxidative stress such as increased levels of P-selection expressing platelets, depleted superoxide dismutase and reactive oxygen species generation as well as elevated levels of inflammatory-related C-reactive protein, interleukin-6 and interleukin-8 were also positively associated with biomass use or elevated particulate matter levels. An important outcome of this investigation was the evidence suggesting important air pollution effects regarding CVD risk in South Asia. However, too few studies have been conducted. There is as an urgent need for longer term investigations using robust measures of air pollution with different population groups that include a wider range of air pollutants and outcomes, including early indicators of CVD. These regions are facing burdens from increasing urbanization, air pollution and populations, generally weaker health infrastructure, aging populations and increased incidence of non-communicable diseases, included CVD. The extent to which the problem of air pollution and CVD will impact these countries will depend largely on the information available to inform policy and programs, which are still lacking, political will as well as social and economic development.
•CFD study of the moist air transonic flow in Laval nozzles by means of single- and two-fluid models.•Mathematical models of condensation processes, homogeneous and heterogeneous.•The study of the ...effect of air relative humidity value on the condensation process and flow in nozzles.•The numerical studies of pollution importance on condensation phenomenon.•Losses estimations in the moist airflow in nozzles.
The paper presents mathematical modelling of water vapour condensation process in the moist air transonic internal flows. The condensation model based on the classical theory of nucleation and molecular-kinetic droplet growth model is implemented into a commercial software ANSYS Fluent. Two approaches are shown in the paper, one in which the air with water droplets is treated as a fluid mixture and second where the water droplets and humid air are computed as separate phases. Both models are validated against in-house and literature experimental studies of internal flow in nozzles. The impact of air humidity and contamination on the condensation process in internal flows for different conditions is examined. The latent heat release in the condensation process influences the flow structure, thus the analysis of condensation wave and shock wave position change with the change of relative air humidity is presented. Moreover, the importance of inertia force and the resulting velocity difference between phases is highlighted. The paper shows that the impact of the condensation in transonic flow is non-negligible and should be taken under consideration in high-velocity flow simulations.
The antagonistic strain Bacillus amyloliquefaciens strain S13‐3 decreased the severity of strawberry anthracnose caused by Colletotrichum gloeosporioides. The foliar application of S13‐3 triggered ...the expression of pathogenesis‐related proteins, chitinase and β‐1,3‐glucanase, in strawberry leaves. We identified lipopeptide antibiotics, including iturin A, fengycin, mixirin, pumilacidin and surfactin, produced and secreted by S13‐3. Iturin A and surfactin elicited the gene expression of the pathogenesis‐related proteins in strawberry leaves, suggesting that antagonistic strain S13‐3 confers resistance to strawberry leaves through the production of lipopeptide antibiotics. In fact, iturin A and surfactin triggered induced systemic resistance on strawberry plants, resulting in the reduction of the severity of anthracnose disease caused by Colletotrichum gloeosporioides. The bifunctional activity of S13‐3, which consists of the antagonistic effect and the induction of plant defence response by the antibiotics produced by it, may make S13‐3 an innovative biological control agent against phytopathogens in strawberry. SIGNIFICANCE AND IMPACT OF THE STUDY: This study tries to determine whether biocontrol of phytopathogens by Bacillus amyloliquefaciens in strawberry can be connected to induced plant resistance. The results suggested that the antagonistic strain B. amyloliquefaciens S13‐3 confers resistance to strawberry through the production of lipopeptide antibiotics.
Spectral D‐type asteroids are characterized by dark, red‐sloped, and featureless spectra at visible and near‐infrared wavelengths and are thought to be composed of rocks rich in organic compounds. ...The Martian satellites, Phobos and Deimos, spectrally resemble D‐type asteroids, suggesting that they are captured D‐type asteroids from outside the Martian system. Here we show that the spectral features of lunar space‐weathered anorthosite are consistent with D‐type spectra, including those of Phobos and Deimos. This can also explain the distinct spectral features on Phobos, the red and blue units, as arising from different degrees of space weathering. Thus, D‐type spectra of the Martian satellites can be explained by space‐weathered anorthosite, indicating that D‐type spectra do not necessarily support the existence of organic compounds, which would be strong evidence for the capture scenario.
Key Points
We show that the spectral features of lunar space‐weathered anorthosite are consistent with D‐type spectra features of Phobos and Deimos
Our data mean that D‐type spectra do not necessarily support the existence of organic compounds
This could also provide important constraints on the origin and evolutions of the Martian system
Context.
Solar-like protostars are known to be chemically rich, but it is not yet clear how much their chemical composition can vary and why. So far, two chemically distinct types of Solar-like ...protostars have been identified: hot corinos, which are enriched in interstellar Complex Organic Molecules, such as methanol (CH
3
OH) or dimethyl ether (CH
3
OCH
3
), and warm carbon chain chemistry (WCCC) objects, which are enriched in carbon chain molecules, such as butadiynyl (C
4
H) or ethynyl radical (CCH). However, none of these have been studied so far in environments similar to that in which our Sun was born, that is, one that is close to massive stars.
Aims.
In this work, we search for hot corinos and WCCC objects in the closest analogue to the Sun’s birth environment, the Orion Molecular Cloud 2/3 (OMC-2/3) filament located in the Orion A molecular cloud.
Methods.
We obtained single-dish observations of CCH and CH
3
OH line emission towards nine Solar-like protostars in this region. As in other similar studies of late, we used the CCH/CH
3
OH abundance ratio in order to determine the chemical nature of our protostar sample.
Results.
Unexpectedly, we found that the observed methanol and ethynyl radical emission (over a few thousands au scale) does not seem to originate from the protostars but rather from the parental cloud and its photo-dissociation region, illuminated by the OB stars of the region.
Conclusions.
Our results strongly suggest that caution should be taken before using CCH/CH
3
OH from single-dish observations as an indicator of the protostellar chemical nature and that there is a need for other tracers or high angular resolution observations for probing the inner protostellar layers.
Rhodomonas sp. Hf-1 strain (cryptophyte) has been known as an excellent feed for some marine animals in aquaculture. In this study, the Hf-1 strain was cultured under different nitrogen ...concentrations to evaluate the effect of N-starved conditions on its growth and biochemical profile. Two nitrate concentrations of 0.9 mM (Low-N) and 3.5 mM (High-N) were supplemented to the media. The cell suspensions were sampled on day 3 and 7 and analyzed for photosynthesis pigments, protein and relative fatty acids contents. The nitrate in Low-N and High-N cultures was exhausted by day 3 and 7, respectively, and growth in Low-N culture was significantly lower than in High-N culture. Phycoerythrin (PE) content decreased in both cultures compared to chlorophyll (Chl) a and c, and a cell-color change was only observed in Low-N culture, indicating that PE was preferentially degraded compared with Chl a and c when nitrogen in the medium was limiting. The intercellular carbon and hydrogen content in the Hf-1 cells cultured in both media showed similar changes throughout the experiment, hence C/H ratios did not differ in between. On the other hand, the intercellular nitrogen content in the Hf-1 cells cultured with High-N medium increased from 5.6 to 10.3% from day 3–7. However, Low-N culture showed a decrease in nitrogen content from 8.1 to 4.1%. Consequently, C/N ratio in Low-N and High-N culture showed entirely different tendency. Similarly, the protein content in the Hf-1 cell cultured with High-N medium increased during 4 days. In contrast, Low-N culture showed a decrease by 30% in protein content. Relative fatty acids content in the Hf-1 cell was lower in Low-N culture than High-N culture through the experiment. The dominant fatty acids in Low-N culture were poly-unsaturated fatty acids (PUFA) on day 3, which accounted for 37.4% of total fatty acid. However, the relative content of PUFA reduced to 24.7% of total fatty acid by the end of the experiment, and the dominant fatty acids shifted to saturated fatty acids (SFA). These data indicate that nitrogen starvation in the medium induced a simultaneous decrease in protein and relative fatty acids contents with the cell-color change for the Hf-1 cell, suggesting the possibility that this behavior on the cell-color change can be used as a valid indicator to determine the harvest timing of Rhodomonas species visually.
•Effects of nitrogen starvation on growth and biochemical profile of Rhodomonas sp. Hf-1 strain were examined.•Nitrogen starvation induced low growth performance and negatively affected the biochemical profile with a distinct cell-color change.•Our results indicated the possibility that the cell-color change can be used as a valid indicator to timely harvest.
Charge-to-spin conversion induced by the Rashba-Edelstein effect was directly observed for the first time in samples with no magnetic layer. A spin-polarized positron beam was used to probe the spin ...polarization of the outermost surface electrons of Bi/Ag/Al2O3 and Ag/Bi/Al2O3 when charge currents were only associated with the Ag layers. An opposite surface spin polarization was found between Bi/Ag/Al2O3 and Ag/Bi/Al2O3 samples with the application of a charge current in the same direction. The surface spin polarizations of both systems decreased exponentially with the outermost layer thickness, suggesting the occurrence of spin diffusion from the Bi/Ag interface to the outermost surfaces. This work provides a new technique to measure spin diffusion length.
During the gastrulation stage in animal embryogenesis, the cells leading the axial mesoderm migrate toward the anterior side of the embryo, vigorously extending cell protrusions such as lamellipodia. ...It is thought that the leading cells sense gradients of chemoattractants emanating from the ectodermal cells and translate them to initiate and maintain the cell movements necessary for gastrulation. However, it is unclear how the extracellular information is converted to the intracellular chemical reactions that lead to motion. Here we demonstrated that intracellular Ca
levels in the protrusion-forming leading cells are markedly higher than those of the following cells and the axial mesoderm cells. We also showed that inhibiting the intracellular Ca
significantly retarded the gastrulation cell movements, while increasing the intracellular Ca
with an ionophore enhanced the migration. We further found that the ionophore treatment increased the active form of the small GTPase Rac1 in these cells. Our results suggest that transient intracellular Ca
signals play an essential role in the active cell migration during gastrulation.
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