We have solved the long-standing problem of the mechanism of terahertz (THz) generation by a two-color filament in air and found that both neutrals and plasma contribute to the radiation. We reveal ...that the contribution from neutrals by four-wave mixing is much weaker and higher in frequency than the distinctive plasma lower-frequency contribution. The former is in the forward direction while the latter is in a cone and reveals an abrupt down-shift to the plasma frequency. Ring-shaped spatial distributions of the THz radiation are shown to be of universal nature and they occur in both collimated and focusing propagation geometries. Experimental measurements of the frequency-angular spectrum generated by 130-fs laser pulses agree with numerical simulations based on a unidirectional pulse propagation model.
Abstract Aim The study of dietary patterns offers a comprehensive, real-life approach towards examining the complex diet and disease relationship. The simultaneous association of dietary patterns ...with inflammation and the metabolic syndrome (MetS) has not been extensively reviewed. This report reviews the association of dietary patterns with inflammation in the context of the MetS. Methods Original English-language research studies with humans were identified via MEDLINE, using inflammation, MetS, whole diets and dietary patterns as keywords. The findings were carefully examined and synthesized along consistent axes. Results Many observational and a few prospective studies, as well as some randomized controlled trials (RCTs), support an inverse association between a Mediterranean dietary pattern and markers of inflammation. The link is generally independent of traditional cardiovascular disease (CVD) risk factors and weight loss. The few studies that have examined the association between following a healthy dietary pattern, evaluated using various diet quality scores, and inflammation report an inverse association; however, this association was attenuated upon adjusting for CVD risk factors. A Mediterranean dietary pattern has also been associated with a reduced risk of the MetS in several cross-sectional studies and a few prospective studies conducted with healthy people. Few RCTs (lasting 1–2 years) have confirmed the benefits of following a Mediterranean diet on MetS risk in obese individuals, in those with the MetS or in those at CVD risk. The evidence, albeit limited, for a link between healthy diets based on other diet quality scores and the MetS supports a similar inverse association for the primary and secondary prevention of the MetS. Conclusion Adhering to healthy diets such as the Mediterranean diet and/or national dietary guidelines can reduce inflammation and the MetS.
Changbaishan and Wang-Tian’e volcanoes of Changbaishan area (Northeast China) were formed with a slight time gap in the last four million years. Wang-Tian’e volcano was formed at 3.8–2.7 Ma; the ...activity of Changbaishan volcano began at the Baishan stage about 1.6 Ma ago. In contrast to the trachybasalt–pantellerite bimodal association of Changbaishan volcano, Wang-Tian’e volcanic rocks are mainly tholeiitic basalts and much less often trachytes and alkaline rhyolites. An alkaline basalt flow has also been recorded on the northern and northeastern slopes of Wang-Tian’e volcano. Our petrological, geochemical, and geochronological data show that the occurrences of tholeiitic and alkaline basaltic magmatism in Changbaishan volcanic area were not synchronous, and the eruptive products of Wang-Tian’e and Changbaishan volcanoes belong to different petrochemical series. The rocks of Wang-Tian’e volcano itself are products of tholeiitic magmas. The alkaline basalt flow is much “younger” (<1.3 Ma) and appeared during the formation of the shield basement of Changbaishan volcano. The alkaline basaltic lavas on the northeastern slope of Wang-Tian’e volcano spread down into the valley as an extensive volcanic flow, forming a single volcanic cover together with the coeval rocks of Changbaishan volcano.
The relationship between diet quality and development of obesity is complex and unresolved. The aim of this study was to assess and compare the predictive value of six different dietary scores on ...both relative weight change and the risk of obesity after 13 years of follow-up in adults aged 45 years and older.
Six scores reflecting adherence to different nutritional recommendations (the French Programme National Nutrition Santé-Guideline Score (PNNS-GS), the Dietary Guidelines for Americans Index (DGAI), the Diet Quality Index-International (DQI-I), the Mediterranean Diet Scale (MDS), the relative Mediterranean Diet Score (rMED) and the Mediterranean Style Dietary Pattern Score (MSDPS)) were estimated in 3151 participants in the French SU.VI.MAX (SUpplémentation en VItamines et Minéraux AntioXydants) study. Associations of dietary scores with 13-year weight change were assessed through multivariate linear regression models, and obesity risk was analyzed with logistic regression, providing odds ratios (OR) and 95% confidence intervals (CI).
Except for the MSDPS, higher scores, that is, better adherence to nutritional guidelines or to a Mediterranean diet, were associated with lower weight gain in men (all P-value for trend <0.05). In addition, among men, ORs for becoming obese after 13 years associated with a 1 s.d. increase in dietary scores ranged from 0.63, 95% CI: 0.51, 0.78 for DGAI to 0.72, 95% CI: 0.59, 0.88 for MDS. These associations were weaker or not statistically significant in women.
Overall, the six dietary scores predicted obesity risk equally well. Among French adults, strong adherence to dietary guidelines appears to be protective with regard to weight gain and obesity, especially in men.
A new empirical magnetospheric magnetic field model is described, driven by interplanetary parameters including a coupling function by Newell et al. (2007), termed henceforth as “N index.” The model ...uses data from Polar, Geotail, Cluster, and Time History of Events and Macroscale Interactions during Substorms satellites, obtained in 1995–2013 at distances 3–60 RE. The model magnetopause is based on Lin et al. (2010) boundary driven by the solar wind pressure, IMF Bz, and the geodipole tilt. The model field includes contributions from the symmetric ring current (SRC), partial ring current (PRC) with associated Region 2 field‐aligned currents (R2 FAC), tail, Region 1 (R1) FAC, and a penetrated IMF. Increase in the N index results in progressively larger magnitudes of all the field sources, the most dramatic and virtually linear growth being found for the PRC and R1 FAC. The solar wind dynamic pressure Pdyn affects the model magnetotail current in proportion to the factor
Pdyn/〈Pdyn〉ζ, where the exponent ζ on the order of 0.4–0.6 steadily decreases with increasing N index. The PRC peaks near midnight at N ∼ 0 but turns duskward with growing N. At ionospheric altitudes, both R1 and R2 FAC expand equatorward with growing N and Pdyn, and the R2 zone rotates westward. Larger values of N result in a more efficient penetration of the IMF into the magnetosphere and larger magnetic flux connection across the magnetopause. Growing dipole tilt is accompanied by a persistent and significant decrease of the total current in all magnetospheric field sources.
Key Points
A magnetosphere B field model is developed, driven by an optimal interplanetary coupling N index
Field‐aligned and partial ring currents dramatically increase with growing N index
Magnitudes of all magnetospheric field sources decrease with increasing dipole tilt
During geomagnetic disturbances, the solar wind arrives in the form of characteristic sequences lasting from tens of hours to days. The most important magnetic storm drivers are the coronal mass ...ejections (CMEs) and the slow‐fast stream interaction regions (SIRs). Previous data‐based magnetic field models did not distinguish between these types of the solar wind driving. In the present work we retained the basic structure of the Tsyganenko and Andreeva (2015) model but fitted it to data samples corresponding to (1) SIR‐driven storms, (2) CME‐driven storms preceded with a shock ahead of the CME, and (3) CME‐driven storms without such shocks. The storm time dynamics of the model current systems has been represented using the parametrization method developed by Tsyganenko and Sitnov (2005), based on dynamical variables Wi, calculated from concurrent solar wind characteristics and their previous history. The database included observations of THEMIS, Polar, Cluster, Geotail, and Van Allen Probes missions during 155 storms in 1997–2016. The model current systems drastically differ from each other with respect to decay rate and total current magnitudes. During SIR‐induced storms, all current systems saturate, while during CME‐induced disturbances, the saturation occurs only for the symmetric ring current and the tail current. The partial ring current parameters are drastically different between SIR‐ and CME‐induced storm sets. In the case of SIR‐driven storms, the total partial ring current is comparable with symmetric ring current, whereas for all CME‐induced events it is nearly twice higher. The results are compared with GOES 15 magnetometer observations.
Plain Language Summary
There exist several different types of disturbed solar wind that hits the Earth's magnetosphere and results in geomagnetic storms. In some cases, the solar wind gusts are caused by long‐lived high‐speed streams from magnetic holes in the Sun's corona, which overtake and compress the quiet flow ahead of them; these are termed “stream interaction regions.” Another largely different type of the solar wind disturbance is called “coronal mass ejections” (CMEs); they form as a result of a sudden eruption of dense clouds of the solar material. The CMEs arrive at the Earth's orbit with or without shock wave. It is well known that stream interaction region and CME result in a different magnetosphere and ionosphere response, but it was not yet taken into account in the data‐based models of the magnetospheric magnetic field. The goal of this work is to describe the response of the Earth's magnetosphere to the solar wind structures of each kind by means of empirical modeling, based on archived spacecraft data, collected during the last two decades. The obtained models use the data of monitors of the interplanetary medium as input and, as such, can be used for forecasting the space weather impact on the Earth's magnetic environment.
Key Points
First results are presented to separately model magnetospheric response to stream interaction regions and coronal mass ejection events
The model current systems significantly differ from each other with respect to their relative strength and relaxation timescales
A new model is used of the magnetic field of Birkeland currents replicating their IMF By‐related splitting and spiraling on the dayside
To study further the factors and mechanisms controlling 10–150 keV particle fluxes in the inner magnetosphere, we investigate empirically their behavior in the nightside transition region (6–14 Re) ...depending on solar wind parameters taken at different time lags. We aim to establish the hierarchy of predictors (V, N, Pd, Ekl = VByz sin2(θ/2), etc.) and the optimal range of their time delays, both depending on the distance and local time. We use THEMIS 5‐min averaged observations of energetic proton and electron fluxes in 2007–2018 near the plasma sheet midplane and build regression models exploring the combination of predictors, taken at time delays up to 24 h. The model obtained shows that protons and electrons are controlled differently by solar wind parameters: electrons are influenced equally by Vsw and Ekl, whereas protons are controlled mostly by Vsw and Pd and less by Ekl. We found that a wide range of time delays is involved depending on distance and particle energy. Specifically, the Ekl affects the energetic fluxes with time delays up to 24 h (or more), exhibiting the long delays in the innermost regions. As regards the mechanism of Vsw influence, the Vsw‐related flux changes are large and, to a large extent, established on the route of the energy flow from solar wind to the plasma sheet and, eventually, the inner magnetosphere. We also identified a new parameter, NBL = VByz cos2(θ/2), which helps to reveal the loss processes in the plasma sheet transition region.
Key Points
Most important predictors of particle flux are Vsw and Ekl for electrons and Vsw and Pd (with smaller impact of Ekl) for protons
Ekl time lags depend on energy and distance, with up to 24 h lag (maximum value for present study) in the region closest to Earth
Solar wind velocity controls the energetic population in the tail plasma sheet
Multipotent mesenchymal stromal cells (MMSCs) are minimally differentiated precursors with great potential to transdifferentiate. These cells are quite resistant to oxygen limitation, suggesting that ...a hypoxic milieu can be physiological for MMSCs.
Human MMSCs isolated from adipose tissue were grown at various oxygen concentrations. Alteration in cell immunophenotype was determined by flow cytometry after staining with specific antibodies. Concentrations of glucose and lactate were determined using the Biocon colorimetric test. Cellular respiration was assessed using oxygen electrode. The modes of cell death were analyzed by flow cytometry after staining with Annexin V and propidium iodide.
We found that permanent oxygen deprivation attenuated cellular ATP levels in these cells, diminishing mitochondrial ATP production but stimulating glycolytic ATP production. At the same time, permanent hypoxia did not affect MMSCs' viability, stimulated their proliferation and reduced their capacity to differentiate. Further, permanent hypoxia decreased spontaneous cell death by MMSCs.
Under hypoxic conditions glycolysis provides sufficient energy to maintain MMSCs in an uncommitted state.
These findings are of interest not only for scientific reasons, but also in practical terms. Oxygen concentration makes an essential contribution to MMSC physiology and should be taken into account in the setting of protocols for cellular therapy.
•Hypoxia diminishes mitochondrial but stimulates glycolytic ATP production in MMSCs.•Hypoxia stimulated proliferation of MMSCs and reduced their capacity to differentiate.•Permanent hypoxia decreased spontaneous cell death by MMSCs.•Glycolysis provides sufficient energy to maintain MMSCs in an uncommitted state.
Local magnetic structures in space environments, in particular, those in the diffusion region such as magnetic nulls or separators, are very difficult to identify by satellite measurements but ...important for understanding of magnetic reconnection. Multi‐spacecraft missions such as Cluster or MMS, however, provide an opportunity to reconstruct the fine structures using vector data of space magnetometers. In this paper, we introduce a method for such a local reconstruction, based on the modified radial basis functions (Andreeva & Tsyganenko, 2016, https://doi.org/10.1002/2016JA023217), used previously for the global magnetic field modeling. A principal advantage of this method is its freedom from a priori assumptions on the magnetic field topology. The method has been tested on 21/2 and 3D reconnection geometries and provided a good agreement with preset models. The relative errors of null positions, γ‐line directions, and ∑‐surface normal directions are found to be below 6% even with 20% random errors added to the target magnetic field vectors in reconstruction of 3D separator model geometry. Applications of the method to the field reconstruction based on Cluster measurements are also presented and discussed.
Key Points
A new method based on radial basis function expanding is developed to reconstruct magnetic structures utilizing multi‐spacecraft data
Without prior imposed current sheet, the method can reconstruct the separator reconnection geometry comprised of two opposite polarity nulls
The coronavirus pandemic has starkly demonstrated the need to create highly effective vaccines against various viral diseases. The emerging new platforms for vaccine creation (adenovirus vectors and ...mRNA vaccines) have shown their worth in the fight against the prevention of coronavirus infection. However, adenovirus vectors and mRNA vaccines have a serious disadvantage: as a rule, only the S protein of the coronavirus is presented as an antigen. This tactic for preventing infection allows the ever-mutating virus to escape quickly from the immunity protection provided by such vaccines. Today, viral genomic databases are well-developed, which makes it possible to create new vaccines on a fundamentally new post-genomic platform. In addition, the technology for the synthesis of nucleic acids is currently experiencing an upsurge in demand in various fields of molecular biology. The accumulated experience suggests that the unique genomic sequences of viruses can act as antigens that trigger powerful humoral and cellular immunity. To achieve this effect, the following conditions must be created: the structure of the nucleic acid must be single-stranded, have a permanent 3D nanostructure, and have a unique sequence absent in the vaccinated organism. Oligonucleotide vaccines are able to resist the rapidly changing genomic sequences of RNA viruses by using conserved regions of their genomes to generate a long-term immune response, acting according to the adage that a diamond cuts a diamond. In addition, oligonucleotide vaccines will not contribute to antibody-dependent enhanced infection, since the nucleic acid of the coronavirus is inside the viral particle. It is obvious that new epidemics and pandemics caused by RNA viruses will continue to arise periodically in the human population. The creation of new, safe, and effective platforms for the production of vaccines that can flexibly change and adapt to new subtypes of viruses is very urgent and at this moment should be considered as a strategically necessary task.
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