Long non-coding RNAs (lncRNAs) have been shown to play regulatory roles in a diverse range of biological processes and are associated with the outcomes of various diseases. The majority of studies ...about lncRNAs focus on model organisms, with lessened investigation in non-model organisms to date. Herein, we have undertaken an investigation on lncRNA in two zoanthids (cnidarian): Protolpalythoa varibilis and Palythoa caribaeorum. A total of 11,206 and 13,240 lncRNAs were detected in P. variabilis and P. caribaeorum transcriptome, respectively. Comparison using NONCODE database indicated that the majority of these lncRNAs is taxonomically species-restricted with no identifiable orthologs. Even so, we found cases in which short regions of P. caribaeorum's lncRNAs were similar to vertebrate species' lncRNAs, and could be associated with lncRNA conserved regulatory functions. Consequently, some high-confidence lncRNA-mRNA interactions were predicted based on such conserved regions, therefore revealing possible involvement of lncRNAs in posttranscriptional processing and regulation in anthozoans. Moreover, investigation of differentially expressed lncRNAs, in healthy colonies and colonial individuals undergoing natural bleaching, indicated that some up-regulated lncRNAs in P. caribaeorum could posttranscriptionally regulate the mRNAs encoding proteins of Ras-mediated signal transduction pathway and components of innate immune-system, which could contribute to the molecular response of coral bleaching.
Abstract
The role of whistler-mode waves in the solar wind and the relationship between their electromagnetic fields and charged particles is a fundamental question in space physics. Using ...high-temporal-resolution electromagnetic field and plasma data from the Magnetospheric MultiScale spacecraft, we report observations of low-frequency whistler waves and associated electromagnetic fields and particle behavior in the Earth’s foreshock. The frequency of these whistler waves is close to half the lower-hybrid frequency (∼2 Hz), with their wavelength close to the ion gyroradius. The electron bulk flows are strongly modulated by these waves, with a modulation amplitude comparable to the solar wind velocity. At such a spatial scale, the electron flows are forcibly separated from the ion flows by the waves, resulting in strong electric currents and anisotropic ion distributions. Furthermore, we find that the low-frequency whistler wave propagates obliquely to the background magnetic field (
B
0
), and results in spatially periodic magnetic gradients in the direction parallel to
B
0
. Under such conditions, large pitch-angle electrons are trapped in wave magnetic valleys by the magnetic mirror force, and may provide free perpendicular electron energy to excite higher-frequency whistler waves. This study offers important clues and new insights into wave–particle interactions, wave generation, and microscale energy conversion processes in the solar wind.
This white paper examines recent progress, applications, and challenges in predicting unbound and total tissue and intra/subcellular drug concentrations using in vitro and preclinical models, imaging ...techniques, and physiologically based pharmacokinetic (PBPK) modeling. Published examples, regulatory submissions, and case studies illustrate the application of different types of data in drug development to support modeling and decision making for compounds with transporter‐mediated disposition, and likely disconnects between tissue and systemic drug exposure. The goals of this article are to illustrate current best practices and outline practical strategies for selecting appropriate in vitro and in vivo experimental methods to estimate or predict tissue and plasma concentrations, and to use these data in the application of PBPK modeling for human pharmacokinetic (PK), efficacy, and safety assessment in drug development.
The Earth's mantle shows large‐scale geochemical heterogeneities bounded by several identifiable end‐member compositions. However, the origin of extreme mantle reservoirs, for example, high ...238U/204Pb (HIMU), and their location in the Earth's interior remains poorly constrained. Clinopyroxenes from late Cenozoic Wudi lavas in eastern China have heterogeneous Pb isotopic compositions, even though the erupted lavas are isotopically homogeneous. Our new results provide, to our knowledge, the first evidence for the existence of a HIMU‐like component in the sources of late Cenozoic lavas. Analyses of olivines and their host lavas indicate that the basaltic melts are derived from partial melting of carbonated peridotite. The HIMU source is likely to be younger than 700 Ma old and related to subduction events of the Paleo‐Asian ocean. In addition to deep and ancient recycling, storage of a metasomatically produced mantle reservoir in the mantle transition zone may be an important mechanism for developing extreme isotopic signatures.
Key Points
We provide the first evidence for the presence of HIMU component in the magma source
Subduction‐related, carbonatite‐metasomatized mantle is a likely candidate for the HIMU reservoir
The transition zone may be an important reservoir in the development of mantle heterogeneities
Recent studies have shown that the ambient plasma in the near-Earth magnetotail can be compressed by the arrival of a dipolarization front (DF). In this paper we study the variations in the ...characteristics of currents flowing in this compressed region ahead of the DF, particularly the changes in the cross-tail current, using observations from the THEMIS satellites. Since we do not know whether the changes in the cross-tail current lead to a field-aligned current formation or just form a current loop in the magnetosphere, we thus use redistribution to represent these changes of local current density. We found that (1) the redistribution of the cross-tail current is a common feature preceding DFs; (2) the redistribution of cross-tail current is caused by plasma pressure gradient ahead of the DF and (3) the resultant net current redistributed by a DF is an order of magnitude smaller than the typical total current associated with a moderate substorm current wedge (SCW). Moreover, our results also suggest that the redistributed current ahead of the DF is closed by currents on the DF itself, forming a closed current loop around peaks in plasma pressure, what is traditionally referred to as a banana current.
Purpose
To develop a new method for high‐fidelity, high‐resolution 3D multi‐slab diffusion MRI with minimal distortion and boundary slice aliasing.
Methods
Our method modifies 3D multi‐slab imaging ...to integrate blip‐reversed acquisitions for distortion correction and oversampling in the slice direction (kz) for reducing boundary slice aliasing. Our aim is to achieve robust acceleration to keep the scan time the same as conventional 3D multi‐slab acquisitions, in which data are acquired with a single direction of blip traversal and without kz‐oversampling. We employ a two‐stage reconstruction. In the first stage, the blip‐up/down images are respectively reconstructed and analyzed to produce a field map for each diffusion direction. In the second stage, the blip‐reversed data and the field map are incorporated into a joint reconstruction to produce images that are corrected for distortion and boundary slice aliasing.
Results
We conducted experiments at 7T in six healthy subjects. Stage 1 reconstruction produces images from highly under‐sampled data (R = 7.2) with sufficient quality to provide accurate field map estimation. Stage 2 joint reconstruction substantially reduces distortion artifacts with comparable quality to fully‐sampled blip‐reversed results (2.4× scan time). Whole‐brain in‐vivo results acquired at 1.22 mm and 1.05 mm isotropic resolutions demonstrate improved anatomical fidelity compared to conventional 3D multi‐slab imaging. Data demonstrate good reliability and reproducibility of the proposed method over multiple subjects.
Conclusion
The proposed acquisition and reconstruction framework provide major reductions in distortion and boundary slice aliasing for 3D multi‐slab diffusion MRI without increasing the scan time, which can potentially produce high‐quality, high‐resolution diffusion MRI.
This paper presents THEMIS measurements of two substorm events to show how the substorm current wedge (SCW) is generated. In the late growth phase when an earthward flow burst in the near‐Earth ...magnetotail brakes and is diverted azimuthally, pressure gradients in the X‐ and Y‐directions are observed to increase in the pileup and diverting regions of the flow. The enhanced pressure gradient in the Y‐direction is dawnward (duskward) on the dawnside (duskside) where a clockwise (counter‐clockwise) vortex forms. This dawn‐dusk pressure gradient drives downward (upward) field‐aligned current (FAC) on the dawnside (duskside) of the flow, which, when combined with the FACs generated by the clockwise (counter‐clockwise) vortex, forms the SCW. Substorm auroral onset occurs when the vortices appear, Near‐Earth dipolarization onset is observed by the THEMIS spacecraft (probes) when a rapid jump in the Y‐component of pressure gradient is detected. The total FACs from the vortex and the azimuthal pressure gradient are found to be comparable to the DP‐1 current in a typical substorm.
Key Points
Two dimensional pressure gradient could be estimated using three satellites
Dawn‐dusk pressure gradient was generated after flow diversion
FAC generated by azimuthal pressure gradient is enough for SCW formation
The space hurricane is a large‐scale three‐dimensional magnetic vortex structure that can cause massive local energy injections in the polar cap. By analyzing Defense Meteorological Satellite Program ...(DMSP) F16–F19 satellite observations from 2005 to 2016, we found that the Southern Hemisphere space hurricane mainly occurs in summer under negative By dominated northward interplanetary magnetic field (IMF) conditions. In particular, the space hurricanes are more likely to occur in the dayside polar cap at magnetic latitude greater than 80°. The characteristics for the Southern Hemisphere are basically consistent with the characteristics of space hurricanes in the Northern Hemisphere. The different dependences of By component in different hemispheres supports the high‐latitude lobe reconnection as the formation mechanism. Plasma data from DMSP satellites in both hemispheres show that the appearance of the space hurricane greatly enhances the convection in the polar cap and the electron density on its dawn side. Within the space hurricane, electron temperatures typically increase significantly, accompanied by strong upward field‐aligned currents and electron precipitation. These results give us a better understanding of the solar wind‐magnetosphere‐polar ionosphere coupling process under northward IMF conditions.
Plain Language Summary
The space hurricane is defined as a large three‐dimensional magnetic vortex structure that spans the polar ionosphere and magnetosphere. Previous research has pointed out that it often appears as an aurora spot near the north magnetic pole, which can greatly enhance the convection patterns and current systems in the polar ionosphere. To clarify its occurrence rate and characteristics in the Southern Hemisphere, we identified the 259 space hurricane events from the long‐term DMSP satellite observations in the Southern Hemisphere. The statistical results indicated that the Southern Hemisphere space hurricanes mainly occur in summer and dayside polar cap under negative By dominated and northward IMF conditions. In addition, we found that the electron temperatures within the space hurricane increased significantly and accompanied by strong upward field‐aligned field currents and electron precipitation. The appearance of the space hurricane greatly enhances the plasma velocity and the electron density on its dawn side. The characteristics in the Southern Hemisphere are basically consistent with the characteristics of space hurricanes in the Northern Hemisphere, and support high‐latitude lobe reconnection as the formation mechanism. This work helps us understand the spatial and temporal characteristics of the space hurricane and their impact on plasma parameters.
Key Points
Space hurricanes in the Southern Hemisphere mainly occur in summer and afternoon sector with negative By dominated northward IMF
Plasma data from DMSP satellites indicate that the space hurricane has enhanced Te, horizontal convection and Ne on its dawn side
Statistical properties of space hurricanes in the Southern Hemisphere are consistent with high‐latitude lobe reconnection
Locating ultracool companions to M dwarfs is important for constraining low-mass formation models, the measurement of substellar dynamical masses and radii, and for testing ultracool evolutionary ...models. We present an optimized method for identifying M dwarfs which may have unresolved ultracool companions. We construct a catalogue of 440 694 M dwarf candidates, from Wide-Field Infrared Survey Explorer, Two Micron All-Sky Survey and Sloan Digital Sky Survey, based on optical- and near-infrared colours and reduced proper motion. With strict reddening, photometric and quality constraints we isolate a subsample of 36 898 M dwarfs and search for possible mid-infrared M dwarf + ultracool dwarf candidates by comparing M dwarfs which have similar optical/near-infrared colours (chosen for their sensitivity to effective temperature and metallicity). We present 1082 M dwarf + ultracool dwarf candidates for follow-up. Using simulated ultracool dwarf companions to M dwarfs, we estimate that the occurrence of unresolved ultracool companions amongst our M dwarf + ultracool dwarf candidates should be at least four times the average for our full M dwarf catalogue. We discuss possible contamination and bias and predict yields of candidates based on our simulations.
Abstract Erythropoietin (EPO), a hematopoietic cytokine, has recently been demonstrated to protect nigral dopaminergic neurons in a mouse model of Parkinson’s disease (PD). In the present study, we ...tested the hypothesis that recombinant human erythropoietin (rhEPO) could protect dopaminergic neurons and improve neurobehavioral outcome in a rat model of PD. rhEPO (20 units in 2 μl of vehicle) was stereotaxically injected into one side of the striatum. 6-Hydroxydopamine (6-OHDA) was injected into the same side 1 day later. Another group of rats received rhEPO (5000 u/kg, i.p.) daily for 8 days, and unilateral injection of 6-OHDA in the striatum 3 days after systemic administration of rhEPO. We observed that intrastriatal administration, but not systemic administration of rhEPO significantly reduced the degree of rotational asymmetry. The rhEPO-treated rats also showed an improvement in skilled forelimb use when compared with control rats. The number of tyrosine hydroxylase (TH)-immunoreactive (IR) neurons in the ipsilateral substantia nigra (SN) was significantly larger in intrastriatal rhEPO-treated rats than that in control rats. TH-IR fibers in the 6-OHDA-lesioned striatum were also increased in the intrastriatal rhEPO-treated rats when compared with control rats. In addition, there were lower levels of expression of major histocompatibility complex (MHC) class II antigens and a smaller number of activated microglia in the ipsilateral SN in intrastriatal rhEPO-treated rats than that in control rats at 2 weeks, suggesting that intrastriatal injection of rhEPO attenuated 6-OHDA-induced inflammation in the ipsilateral SN. Our results suggest that intrastriatal administration of rhEPO can protect nigral dopaminergic neurons from cell death induced by 6-OHDA and improve neurobehavioral outcome in a rat model of PD. Anti-inflammation may be one of mechanisms responsible for rhEPO neuroprotection.
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