340 research outputs found
Evolution of Anemone AR NOAA 10798 and the Related Geo-Effective Flares and CMEs
We present a detailed examination of the features of the Active Region (AR)
NOAA 10798. This AR generated coronal mass ejections (CMEs) that caused a large
geomagnetic storm on 24 August 2005 with the minimum Dst index of -216 nT. We
examined the evolution of the AR and the features on/near the solar surface and
in the interplanetary space. The AR emerged in the middle of a small coronal
hole, and formed a {\it sea anemone} like configuration. H filaments
were formed in the AR, which have southward axial field. Three M-class flares
were generated, and the first two that occurred on 22 August 2005 were followed
by Halo-type CMEs. The speeds of the CMEs were fast, and recorded about 1200
and 2400 km s, respectively. The second CME was especially fast, and
caught up and interacted with the first (slower) CME during their travelings
toward Earth. These acted synergically to generate an interplanetary
disturbance with strong southward magnetic field of about -50 nT, which was
followed by the large geomagnetic storm.Comment: 32 pages, 9 figures, JGR accepte
Glucose transport in interlobular ducts isolated from rat pancreas
Pancreatic duct cells express Na+-dependent glucose transporter, SGLT1 and Na+-independent glucose transporters, GLUT1, GLUT2, and GLUT8. We examined transepithelial glucose transport by pancreatic duct. Interlobular ducts were isolated from rat pancreas. During overnight culture both ends of the duct segments sealed spontaneously. The lumen of the sealed duct was micropunctured and the luminal fluid was replaced by HEPES-buffered solution containing 10.0 mM or 44.4 mM glucose. The bath was perfused with HEPES-buffered solution at 37℃ containing 10.0 or 44.4 mM glucose. Transepithelial differences in osmolality were balanced with mannitol. Glucose transport across ductal epithelium was measured by monitoring changes in luminal volume. When the lumen was filled with 44.4 mM glucose, with either 10.0 or 44.4 mM glucose in the bath, the luminal volume decreased to 65~70% of the initial volume in 15 min. Luminally-injected phlorizin, an inhibitor of SGLT1, abolished the decrease in luminal volume. With 10.0 mM glucose in the lumen and 44.4 mM glucose in the bath, the luminal volume did not change significantly. Luminal application of phlorizin under identical condition led to an increase in luminal volume. The data suggest that both active and passive transport mechanisms of glucose are present in pancreatic ductal epithelium
Time–frequency analysis of the surface electrocardiogram for monitoring antiarrhythmic drug effects in atrial fibrillation
CFTR Functions as a Bicarbonate Channel in Pancreatic Duct Cells
Pancreatic duct epithelium secretes a HCO3−-rich fluid by a mechanism dependent on cystic fibrosis transmembrane conductance regulator (CFTR) in the apical membrane. However, the exact role of CFTR remains unclear. One possibility is that the HCO3− permeability of CFTR provides a pathway for apical HCO3− efflux during maximal secretion. We have therefore attempted to measure electrodiffusive fluxes of HCO3− induced by changes in membrane potential across the apical membrane of interlobular ducts isolated from the guinea pig pancreas. This was done by recording the changes in intracellular pH (pHi) that occurred in luminally perfused ducts when membrane potential was altered by manipulation of bath K+ concentration. Apical HCO3− fluxes activated by cyclic AMP were independent of Cl− and luminal Na+, and substantially inhibited by the CFTR blocker, CFTRinh-172. Furthermore, comparable HCO3− fluxes observed in ducts isolated from wild-type mice were absent in ducts from cystic fibrosis (ΔF) mice. To estimate the HCO3− permeability of the apical membrane under physiological conditions, guinea pig ducts were luminally perfused with a solution containing 125 mM HCO3− and 24 mM Cl− in the presence of 5% CO2. From the changes in pHi, membrane potential, and buffering capacity, the flux and electrochemical gradient of HCO3− across the apical membrane were determined and used to calculate the HCO3− permeability. Our estimate of ∼0.1 µm sec−1 for the apical HCO3− permeability of guinea pig duct cells under these conditions is close to the value required to account for observed rates of HCO3− secretion. This suggests that CFTR functions as a HCO3− channel in pancreatic duct cells, and that it provides a significant pathway for HCO3− transport across the apical membrane
Dendritic cell vaccination as postremission treatment to prevent or delay relapse in acute myeloid leukemia
Relapse is a major problem in acute myeloid leukemia (AML) and adversely impacts survival.
In this phase II study, we investigated the effect of vaccination with dendritic cells (DCs)
electroporated with Wilms’ tumor 1 (WT1) mRNA as post-remission treatment in 30 AML
patients at very high risk of relapse. There was a demonstrable anti-leukemic response in 13
patients. Nine patients achieved molecular remission as demonstrated by normalization
of WT1 transcript levels, 5 of which are sustained after a median follow-up of 109.4 months.
Disease stabilization was achieved in 4 other patients. Five-year overall survival (OS) was
higher in responders than in non-responders (53.8% vs. 25.0%; P=0.01). In patients
receiving DCs in first complete remission (CR1), there was a vaccine-induced relapse
reduction rate of 25% and the 5-year relapse-free survival was higher in responders than in
non-responders (50% vs. 7.7%; P65 years who received DCs
in CR1, 5-year OS was 69.2% and 30.8% respectively, as compared to 51.7% and 18% in
the Swedish Acute Leukemia Registry (SALR). Long-term clinical response was correlated
with increased circulating frequencies of poly-epitope WT1-specific CD8+ T-cells. Long-term
OS was correlated with interferon-γ+ and tumor necrosis factor-α+ WT1-specific responses in delayed type hypersensitivity-infiltrating CD8+ T-lymphocytes. In conclusion, vaccination of
AML patients with WT1 mRNA-electroporated DCs can be an effective strategy to prevent or
delay relapse after standard chemotherapy, translating into improved OS rates, which are
correlated with the induction of WT1-specific CD8+ T-cell response. This trial was registered
at www.clinicaltrials.gov as #NCT00965224
Photosynthetic responses in Phaeocystis antarctica towards varying light and iron conditions
The effects of iron limitation on photoacclimation to a dynamic light regime were studied in Phaeocystis antarctica. Batch cultures were grown under a sinusoidal light regime, mimicking vertical mixing, under both iron-sufficient and -limiting conditions. Iron-replete cells responded to changes in light intensity by rapid xanthophyll cycling. Maximum irradiance coincided with maximum ratios of diatoxanthin/diadinoxanthin (dt/dd). The maximum quantum yield of photosynthesis (F-v /F-m) was negatively related to both irradiance and dt/dd. Full recovery of F-v /F-m by the end of the light period suggested successful photoacclimation. Iron-limited cells displayed characteristics of high light acclimation. The ratio of xanthophyll pigments to chlorophyll a was three times higher compared to iron-replete cells. Down-regulation of photosynthetic activity was moderated. It is argued that under iron limitation cells maintain a permanent state of high energy quenching to avoid photoinhibition during exposure to high irradiance. Iron-limited cells could maintain a high growth potential due to an increased absorption capacity as recorded by in vivo absorption, which balanced a decrease in F-v/F-m . The increase in the chlorophyll a-specific absorption cross section was related to an increase in carotenoid pigments and a reduction in the package effect. These experiments show that P. antarctica can acclimate successfully to conditions as they prevail in the Antarctic ocean, which may explain the success of this species
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Prosociality from Early Adolescence to Young Adulthood: A Longitudinal Study of Individuals with a History of Language Impairment
Background: Longitudinal research into the development of prosociality contributes vitally to understanding of individual differences in psychosocial outcomes. Most of the research to date has been concerned with prosocial behaviour in typically developing young people; much less has been directed to the course of development in individuals with developmental disorders.
Aims: This study reports a longitudinal investigation of prosocial behaviour in young people with language impairment (LI), and compares trajectories of development to typically developing age-matched peers (AMPs).
Methods and Procedures: Participants were followed from age 11 years to young adulthood (age 24 years).
Outcomes and Results: Participants with LI perceived themselves as prosocial; their ratings – though lower than those for the AMPs - were well within the normal range and they remained consistently so from 11 to 24 years. Two different developmental trajectories were identified for the LI group, which were stable and differed only in level of prosociality. Approximately one third of participants with LI followed a moderate prosociality trajectory whilst the majority (71%) followed a prosocial trajectory. We found evidence of protective effects of prosociality for social outcomes in young adulthood.
Conclusions and Implications:
The findings indicate that prosociality is an area of relative strength in LI
Vitamin A Enhances Antitumor Effect of a Green Tea Polyphenol on Melanoma by Upregulating the Polyphenol Sensing Molecule 67-kDa Laminin Receptor
BACKGROUND: Green tea consumption has been shown to have cancer preventive qualities. Among the constituents of green tea, (-)-Epigallocatechin-3-O-gallate (EGCG) is the most effective at inhibiting carcinogenesis. However, the concentrations of EGCG that are required to elicit the anticancer effects in a variety of cancer cell types are much higher than the peak plasma concentration that occurs after drinking an equivalent of 2-3 cups of green tea. To obtain the anticancer effects of EGCG when consumed at a reasonable concentration in daily life, we investigated the combination effect of EGCG and food ingredient that may enhance the anticancer activity of EGCG on subcutaneous tumor growth in C57BL/6N mice challenged with B16 melanoma cells. METHODOLOGY/PRINCIPAL FINDINGS: All-trans-retinoic acid (ATRA) enhanced the expression of the 67-kDa laminin receptor (67LR) and increased EGCG-induced cell growth inhibition in B16 melanoma cells. The cell growth inhibition seen with the combined EGCG and ATRA treatment was abolished by treatment with an anti-67LR antibody. In addition, the combined EGCG and ATRA treatment significantly suppressed the melanoma tumor growth in mice. Expression of 67LR in the tumor increased upon oral administration of ATRA or a combined treatment of EGCG and ATRA treatment. Furthermore, RNAi-mediated silencing of the retinoic acid receptor (RAR) alpha attenuated the ATRA-induced enhancement of 67LR expression in the melanoma cells. An RAR agonist enhanced the expression levels of 67LR and increased EGCG-induced cell growth inhibition. CONCLUSIONS/SIGNIFICANCE: Our findings provide a molecular basis for the combination effect seen with dietary components, and indicate that ATRA may be a beneficial food component for cancer prevention when combined with EGCG
Seasonal variations in the nitrogen isotopic composition of settling particles at station K2 in the western subarctic North Pacific
Intensive observations using hydrographical cruises and moored sediment trap deployments during 2010 and 2012 at station K2 in the North Pacific western subarctic gyre (WSG) revealed seasonal changes in δ15N of both suspended and settling particles. Suspended particles (SUS) were collected from depths between the surface and 200 m; settling particles by drifting traps (DST; 100-200 m) and moored traps (MST; 200 and 500 m). All particles showed higher δ15N values in winter and lower in summer, contrary to the expected by isotopic fractionation during phytoplankton nitrate consumption. We suggest that these observed isotopic patterns are due to ammonium consumption via light-controlled nitrification, which could induce variations in δ15N(SUS) of 0.4-3.1 ‰ in the euphotic zone (EZ). The δ15N(SUS) signature was reflected by δ15 N(DST) despite modifications during biogenic transformation from suspended particles in the EZ. δ15 N enrichment (average: 3.6 ‰) and the increase in C:N ratio (by 1.6) in settling particles suggests year-round contributions of metabolites from herbivorous zooplankton as well as TEPs produced by diatoms. Accordingly, seasonal δ15 N(DST) variations of 2.4-7.0 ‰ showed a significant correlation with primary productivity (PP) at K2. By applying the observed δ15 N(DST) vs. PP regression to δ15 N(MST) of 1.9-8.0 ‰, we constructed the first annual time-series of PP changes in the WSG. Moreover, the monthly export ratio at 500 m was calculated using both estimated PP and measured organic carbon fluxes. Results suggest a 1.6 to 1.8 times more efficient transport of photosynthetically-fixed carbon to the intermediate layers occurs in summer/autumn rather than winter/spring
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