ALBERT

Beschreibung: In the Vietnamese Mekong Delta (VMD), water levels at some stations have increased. However, the factors that cause this rise in the VMD have not been identified. We considered four factors that may have contributed to the water level rise: (1) increased runoff from upstream, (2) sea-level rise, (3) land subsidence, and (4) decrease in flood mitigation function due to construction of high dykes. We analyzed daily maximum and minimum water levels, and mean daily water levels from 24 monitoring stations from 1987 to 2006. Using daily and annual water level differences, we classified the delta into two groups; one is dominated by flows from upstream, while the other is tide-dominated. We then tested the trends of annual maximum and minimum water levels using the Mann-Kendall test, and identified the slope of the trend using the method of Sen. The areas of dyke construction were estimated using the Enhanced Vegetation Index (EVI) and Land Surface Water Index (LSWI) from the Moderate Resolution Imaging Spectroradiometer (MODIS) data. Results show (1) river inflow has little impact on rising water levels in the VMD, (2) the influence of high dykes on water level rise could not be quantified in this study, (3) both maximum and minimum water levels significantly increased in the tide-dominated area. Trend of annual minimum water level can be considered as the sum sea-level rise and land subsidence. Therefore, we attribute 6.05 mm year −1 (80%) to land subsidence and 1.42 mm year −1 (20%) to sea level rise, indicating inundations have been severe in the VMD, caused primarily by land subsidence. This article is protected by copyright. All rights reserved.

Beschreibung: Using the fan sector backscatter maps of 47 MHz Equatorial Atmosphere Radar (EAR) at Kototabang (0.2 o S geog. lat, 100.3 o E geog. long and 10.4 o S geomag. lat), Indonesia, the spatial and temporal evolution of equatorial plasma bubbles (EPBs) were examined to classify the evolutionary type EPBs from those which formed elsewhere and drifting into the field of view of radar. A total of 535 EPBs were observed during the low to moderate solar activity years 2010 – 2012, out of which, about 210 (~39%) are of evolving-type and the remaining 325 (~61%) are drifting-in EPBs. In general, both the evolving-type and drifting-in EPBs exhibit predominance during the post-sunset hours of equinoxes and December solstices. Interestingly, a large number of EPBs were found to develop even a few minutes prior to the apex sunset during equinoxes. Further, the occurrence of evolving-type EPBs exhibits a clear secondary peak around midnight (2300 – 0100 LT), primarily, due to higher rate of occurrence during the post-midnight hours of June solstices. A significant number (~33%) of post-midnight EPBs generated during June solstices did not exhibited any clear zonal drift while about 14% of EPBs drifted westward. Also, the westward drifting EPBs are confined only to June solstices. The responsible mechanisms for the genesis of fresh EPBs during post-midnight hours were discussed in light of equatorward meridional winds in the presence of weak westward electric fields.

Beschreibung: Plasma density depletions in the equatorial ionosphere, or so-called equatorial plasma bubbles (EPBs) are generated in the post-sunset period and tend to have a very complex spatial structure. Especially, the east-west asymmetry of EPBs has been reported by various observations. Using a high-resolution bubble (HIRB) model, which is a newly developed three-dimensional numerical model for the equatorial ionosphere, small-scale structuring at the west wall of large-scale F -layer upwelling is clearly reproduced for the first time. It is not an eastward neutral wind but a vertical shear of zonal plasma drift velocity at the bottomside of the F region that plays an important role in accelerating the instability growth at the west wall and generating the east-west asymmetry of EPBs.

Beschreibung: Mesenchymal stem cell (MSC)-conditioned medium (MSC-CM) has been reported to enhance wound healing. Exosomes contain nucleic acids, proteins, and lipids, and function as an intercellular communication vehicle for mediating some paracrine effects. However, the function of MSC-exosomes (MSC-exo) remains elusive. In this study, we isolated human placenta MSC (PlaMSC)-derived exosomes (PlaMSC-exo) and examined their function in vitro . PlaMSCs were isolated from human term placenta using enzymatic digestion. PlaMSC-exo were prepared from the conditioned medium of PlaMSC (PlaMSC-CM) by ultracentrifugation. The expression of stemness-related genes, such as OCT4 and NANOG, in normal adult human dermal fibroblasts (NHDF) after incubation with PlaMSC-exo was measured by real-time reverse transcriptase PCR analysis (real-time PCR). The effect of PlaMSC-exo on Oct4 transcription activity was assessed using Oct4-EGFP reporter mice-derived dermal fibroblasts. The stimulating effects of PlaMSC-exo on osteoblastic and adipogenic differentiation of NHDF were evaluated by alkaline phosphatase (ALP), and Alizarin red S- and oil red O-staining, respectively. The expression of osteogenic and adipogenic related genes was also assessed by real-time PCR. The treatment of NHDF with PlaMSC-exo significantly upregulated OCT4 and NANOG mRNA expression. PlaMSC-exo also enhanced Oct4 transcription. The NHDF treated with PlaMSC-exo exhibited osteogenic and adipogenic differentiation of NHDF in osteogenic and adipogenic induction media. PlaMSC-exo increase the expression of OCT4 and NANOG mRNA in fibroblasts. As a result, PlaMSC-exo influence the differentiation competence of fibroblasts to both osteoblastic and adipogenic differentiation. It shows a new feature of MSCs and the possibility of clinical application of MSC-exo. This article is protected by copyright. All rights reserved

Beschreibung: Simultaneous observations of F2 layer stratification and spread F at post-midnight (00:00 LT-05:00 LT) were carried out on 22, 23 and 28 November 2013, using ionosondes distributed over a northern equatorial anomaly region at three specific locations, i.e., Puer (PUR,22.7°N, 101.05°E, dip latitude 12.9°N), Chiang Mai (CMU, 18.8°N, 98.9°E, dip latitude 9.04°N), and Chumphon (CPN, 10.7°N, 99.4°E, dip latitude 0.93°N) . The results show that both the PUR and CMU stations observed the F2 layer stratification at post-midnight in the northern hemisphere, frequently accompanied with gravity waves (the periods~30-100 min). It is reported that F2 layer stratification at post-midnight can be observed in the northern hemisphere for the first time. It is suggested that the thermospheric neutral wind triggered by gravity waves strongly contribute to the altitude dependence of the combined vertical plasma velocity, which consequently poses significant impacts on the occurrence of the low-latitude F2 layer stratification at post-midnight. In addition, the spread F other than F2 layer stratification was observed at the CPN station located at the geomagnetic equator, suggesting that smaller geomagnetic inclination tend to inhibit the post-midnight F2 layer stratification in the equatorial region. Furthermore, on 23 November 2013 a good correlation was identified between the F2 layer stratification at PUR and the spread F at both CMU and CPN, possibly due to that the large-scale gravity waves originating at middle latitudes contribute to the nighttime spread F observed in the low-latitude and equatorial regions.

Beschreibung: The equatorial zonal electric field responses to prompt penetration of eastward convection electric fields (PPEF) were compared at closely spaced longitudinal intervals at dusk to pre-midnight sectors during the intense geomagnetic storm of March 17, 2015. At dusk sector (Indian longitudes), a rapid uplift of equatorial F-layer to 〉550 km and development of intense equatorial plasma bubbles (EPBs) were observed. These EPBs were found to extend up to 27.13 o N and 25.98 o S magnetic dip latitudes indicating their altitude development to ~1670 km at apex. In contrast, at few degrees east in the pre-midnight sector (Thailand-Indonesian longitudes), no significant height rise and/or EPB activity has been observed. The eastward electric field perturbations due to PPEF are greatly dominated at dusk sector despite the existence of background westward ionospheric disturbance dynamo (IDD) fields, whereas, they were mostly counter-balanced by the IDD fields in the pre-midnight sector. In-situ observations from SWARM-A,C and C/NOFS satellites detected a large plasma density depletion near Indian equatorial region due to large electrodynamic uplift of F-layer to higher than satellite altitudes. Further, this large uplift is found to confine to a narrow longitudinal sector centered on sunset terminator. This study brings out the significantly enhanced equatorial zonal electric field in response to PPEF that is uniquely confined to dusk sector. The responsible mechanisms are discussed in terms of unique electrodynamic conditions prevailing at dusk sector in the presence of convection electric fields associated with the onset of a substorm under southward IMF Bz.

Beschreibung: The boron isotope ratio (δ 11 B) of marine biogenic carbonates can reconstruct pH and p CO 2 of seawater, and potentially CO 2 concentration in the atmosphere. To date, δ 11 B-pH SW calibration has been proposed via culturing experiments, where calcifying organisms are cultured under artificially acidified seawater. However, in scleractinian corals, reconstructed pH values using culture-based calibrations do not agree well with actual observations of seawater CO 2 chemistry. Thus, another approach is needed to establish a more reliable calibration method. In this study, we established field-based calibrations for Chichijima and Tahiti, both located in subtropical gyres where surface seawater is close to CO 2 equilibrium. We suggest a new approach to calibration of δ 11 B-pH in which the long-term δ 11 B variation of massive Porites corals is compared with the decreasing pH trend (i.e., ocean acidification) that has occurred since the Industrial Revolution. This calibration will offer a new avenue for studying seawater CO 2 chemistry using coral δ 11 B in diverse settings, such as upwelling regions, coral reefs, and coastal areas. This article is protected by copyright. All rights reserved.

Beschreibung: The unusual evolution of fresh and intense field aligned irregularities (FAI) near sunrise terminator which further sustained for more than 90 minutes of post-sunrise period was observed by Equatorial Atmosphere Radar (EAR) at Kototabang during a minor geomagnetic storm period. These FAI echoes were initially observed around 250 – 350km altitudes, growing upward under eastward polarization electric fields indicating the plasma bubbles that are fully depleted along the flux tube. The background low-latitude F-layer dynamics that lead to the development of these dawn-time FAI have been investigated from two ionosondes at near magnetic conjugate low-latitude locations. A minor geomagnetic storm was in progress which did not appear to cause any large electric field perturbations at preceding post-sunset to midnight period over Indonesian sector. However, the prompt penetration of overshielding electric fields associated with sudden northward turning of IMF Bz caused spectacular ascent of F layer and development of fresh, intense and upward evolutionary plasma bubbles near sunrise terminator.

Beschreibung: The editorial and scientific publishing process relies on the sustained work of volunteer reviewers, and evaluating the inter-disciplinary and broad interest papers published in G-Cubed can be a particular challenge. As editors and associated editors, we are therefore hugely appreciative of the efforts of our reviewers, and would like to thank and acknowledge them in this editorial. G-Cubed published 257 manuscripts out of 431 submissions in 2014, and for this we were able to rely on the efforts of 710 dedicated reviewers. Their names are listed below, in italics those 27 who provided three or more reviews. A big thank you from the G-Cubed team!. This article is protected by copyright. All rights reserved.

Beschreibung: In the Vietnamese Mekong Delta (VMD), water levels at some stations have increased. However, the factors that cause this rise in the VMD have not been identified. We considered four factors that may have contributed to the water level rise: (1) increased runoff from upstream, (2) sea-level rise, (3) land subsidence, and (4) decrease in flood mitigation function because of construction of high dykes. We analysed daily maximum and minimum water levels, and mean daily water levels from 24 monitoring stations from 1987 to 2006. Using daily and annual water level differences, we classified the delta into two groups: one is dominated by flows from upstream, while the other is tide dominated. We then tested the trends of annual maximum and minimum water levels using the Mann-Kendall test, and identified the slope of the trend using the method of Sen. The areas of dyke construction were estimated using the Enhanced Vegetation Index (EVI) and Land Surface Water Index (LSWI) from the Moderate Resolution Imaging Spectroradiometer (MODIS) data. Results show (1) river inflow has little impact on rising water levels in the VMD, (2) the influence of high dykes on water level rise could not be quantified in this study, and (3) both maximum and minimum water levels significantly increased in the tide-dominated area. Trend of annual minimum water level can be considered as the sum sea-level rise and land subsidence. Therefore, we attribute 6.05mmyear-1 (80%) to land subsidence and 1.42mmyear-1 (20%) to sea level rise, indicating that inundations have been severe in the VMD, caused primarily by land subsidence. © 2016 John Wiley & Sons, Ltd.