7 research outputs found
Adopting microblogging solutions for interaction with government
Authorities in the People’s Republic of China communicate with citizens using an estimated 600,000 Sina Weibo microblogs. This study reports on a study of Chinese citizens’ adoption of microblogs to interact with the government. Adoption results from trust and peer pressure in smaller-network ties (densely knit, pervasive social networks surrounding individual citizens). Larger-network ties (trust in institutions at large, such as the Chinese Communist Party, executive organizations, the judicial system, the media, etc.) are not associated with the adoption of microblogging. Furthermore, higher levels of anxiety are correlated with lower levels of use intention, and this finding underlines the impact of the Chinese authority’s surveillance and control activities on the lives of individual Chinese citizens. Based on these findings, we outline a theory of why citizens use microblogs to interact with the government and suggest avenues for further research into microblogs, state–citizen communication patterns and technology adoption
Electroacupuncture pretreatment attenuates cerebral ischemic injury through α7 nicotinic acetylcholine receptor-mediated inhibition of high-mobility group box 1 release in rats
<p>Abstract</p> <p>Background</p> <p>We have previously reported that electroacupuncture (EA) pretreatment induced tolerance against cerebral ischemic injury, but the mechanisms underlying this effect of EA are unknown. In this study, we assessed the effect of EA pretreatment on the expression of α7 nicotinic acetylcholine receptors (α7nAChR), using the ischemia-reperfusion model of focal cerebral ischemia in rats. Further, we investigated the role of high mobility group box 1 (HMGB1) in neuroprotection mediated by the α7nAChR and EA.</p> <p>Methods</p> <p>Rats were treated with EA at the acupoint "Baihui (GV 20)" 24 h before focal cerebral ischemia which was induced for 120 min by middle cerebral artery occlusion. Neurobehavioral scores, infarction volumes, neuronal apoptosis, and HMGB1 levels were evaluated after reperfusion. The α7nAChR agonist PHA-543613 and the antagonist α-bungarotoxin (α-BGT) were used to investigate the role of the α7nAChR in mediating neuroprotective effects. The roles of the α7nAChR and HMGB1 release in neuroprotection were further tested in neuronal cultures exposed to oxygen and glucose deprivation (OGD).</p> <p>Results</p> <p>Our results showed that the expression of α7nAChR was significantly decreased after reperfusion. EA pretreatment prevented the reduction in neuronal expression of α7nAChR after reperfusion in the ischemic penumbra. Pretreatment with PHA-543613 afforded neuroprotective effects against ischemic damage. Moreover, EA pretreatment reduced infarct volume, improved neurological outcome, inhibited neuronal apoptosis and HMGB1 release following reperfusion, and the beneficial effects were attenuated by α-BGT. The HMGB1 levels in plasma and the penumbral brain tissue were correlated with the number of apoptotic neurons in the ischemic penumbra. Furthermore, OGD in cultured neurons triggered HMGB1 release into the culture medium, and this effect was efficiently suppressed by PHA-543,613. Pretreatment with α-BGT reversed the inhibitory effect of PHA-543,613 on HMGB1 release.</p> <p>Conclusion</p> <p>These data demonstrate that EA pretreatment strongly protects the brain against transient cerebral ischemic injury, and inhibits HMGB1 release through α7nAChR activation in rats. These findings suggest the novel potential for stroke interventions harnessing the anti-inflammatory effects of α7nAChR activation, through acupuncture or pharmacological strategies.</p
Regulation of Asymmetrical Cytokinesis by cAMP during Meiosis I in Mouse Oocytes
Mammalian oocytes undergo an asymmetrical first meiotic division, extruding half of their chromosomes in a small polar body to preserve maternal resources for embryonic development. To divide asymmetrically, mammalian oocytes relocate chromosomes from the center of the cell to the cortex, but little is known about the underlying mechanisms. Here, we show that upon the elevation of intracellular cAMP level, mouse oocytes produced two daughter cells with similar sizes. This symmetrical cell division could be rescued by the inhibition of PKA, a cAMP-dependent protein kinase. Live cell imaging revealed that a symmetrically localized cleavage furrow resulted in symmetrical cell division. Detailed analyses demonstrated that symmetrically localized cleavage furrows were caused by the inappropriate central positioning of chromosome clusters at anaphase onset, indicating that chromosome cluster migration was impaired. Notably, high intracellular cAMP reduced myosin II activity, and the microinjection of phospho-myosin II antibody into the oocytes impeded chromosome migration and promoted symmetrical cell division. Our results support the hypothesis that cAMP plays a role in regulating asymmetrical cell division by modulating myosin II activity during mouse oocyte meiosis I, providing a novel insight into the regulation of female gamete formation in mammals
Ancient human genomes suggest three ancestral populations for present day Europeans
We sequenced genomes from a 7,000 year old early farmer from Stuttgart
in Germany, an 8,000 year old hunter-gatherer from Luxembourg, and seven
8,000 year old hunter-gatherers from southern Sweden. We analyzed these
data together with other ancient genomes and 2,345 contemporary humans to show
that the great majority of present-day Europeans derive from at least three
highly differentiated populations: West European Hunter-Gatherers (WHG), who
contributed ancestry to all Europeans but not to Near Easterners; Ancient North
Eurasians (ANE), who were most closely related to Upper Paleolithic Siberians
and contributed to both Europeans and Near Easterners; and Early European
Farmers (EEF), who were mainly of Near Eastern origin but also harbored
WHG-related ancestry. We model these populations' deep relationships and show
that EEF had 44% ancestry from a "Basal Eurasian" lineage that split
prior to the diversification of all other non-African lineages