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We investigate the nature of a Galactic Centre source, G0.17+0.15, lying along the northern extension of the radio arc near l ∼ 0.2°. G0.17+0.15 is an H ii region located towards the eastern edge of the radio bubble, embedded within the highly polarized Galactic Centre eastern lobe where a number of radio filaments appear to cross through the H ii region. We report the detection of hydrogen and helium recombination lines with a radial velocity exceeding 140 km s−1 based on Green Bank Telescope and Very Large Array observations. The morphology of G0.17+0.15, aided by kinematics, and spectral index characteristics, suggests the presence of an external pressure dragging and shredding the ionized gas. We argue that this ionized cloud is interacting with a bundle of radio filaments and is entrained by the ram pressure of the radio bubble, which itself is thought to be produced by cosmic ray driven outflows at the Galactic Centre. In this interpretation, the gas streamers on the western side of G0.17+0.15 are stripped, accelerated from 0 to $\delta v\sim \, 35$ km s−1 over a time-scale roughly 8 × 104 yr, implying that ablating ram pressure is $\sim 700\, \mathrm{eV\, cm^{-3}}$, comparable to the $\sim 10^3\, \mathrm{eV \, cm^{-3}}$ cosmic ray driven wind pressure in the Galactic Centre region.

 

The Snake is a remarkable Galactic Centre radio filament with a morphology characterized by two kinks along its ∼20 arcmin extent. The major and minor kinks are located where the filament is most distorted from a linear magnetized structure running perpendicular to the Galactic plane. We present Chandra, VLA, and MeerKAT data and report the detection of an X-ray and radio source at the location of the major kink. High-resolution radio images of the major kink reveal a compact source with a steep spectrum with spectral index α ∼ −2.7 surrounded by extended emission. The radio luminosity and steep spectrum of the compact source are consistent with a pulsar. We also show flattening of the spectrum and enhanced synchrotron emissivity away from the position of the major kink along the Snake, which suggests injection of relativistic particles along the Snake. We argue that the major kink is created by a fast-moving (∼500–1000 km s−1) object punching into the Snake, distorting its magnetic structure, and producing X-ray emission. X-ray emission pinpoints an active acceleration site where the interaction is taking place. A secondary kink is argued to be induced by the impact of the high-velocity object producing the major kink.

 

Oceanic eddies accompanied by a significant vertical velocity ( w ) are known to be of great importance for the vertical transport of various climatically, biologically or biogeochemically relevant properties. Using quasi-geostrophic w -thinking to extend the classic “ β -spiral” w -theory for gyre circulations to isolated and nearly symmetric oceanic mesoscale eddies, we propose that their w motion will be dominated by a strong east-west dipole pattern with deep ocean penetrations. Contrasting numerical simulations of idealized isolated eddies together with w -equation diagnostics confirm that the w -dipole is indeed dominated by the “eddy β -spiral” mechanism in the β -plane simulation, whereas this w -dipole expectedly disappears in the f -plane simulation. Analyses of relatively isolated warm and cold eddy examples show good agreement with the proposed mechanism. Our studies further clarify eddy vertical motions, have implications for ocean mixing and vertical transport, and inspire further studies. 

Global sea-level rise is transforming coastal ecosystems, especially freshwater wetlands, in part due to increased episodic or chronic saltwater exposure, leading to shifts in biogeochemistry, plant- and microbial communities, as well as ecological services. Yet, it is still difficult to predict how soil microbial communities respond to the saltwater exposure because of poorly understood microbial sensitivity within complex wetland soil microbial communities, as well as the high spatial and temporal heterogeneity of wetland soils and saltwater exposure. To address this, we first conducted a two-year survey of microbial community structure and bottom water chemistry in submerged surface soils from 14 wetland sites across the Florida Everglades. We identified ecosystem-specific microbial biomarker taxa primarily associated with variation in salinity. Bacterial, archaeal and fungal community composition differed between freshwater, mangrove, and marine seagrass meadow sites, irrespective of soil type or season. Especially, methanogens, putative denitrifying methanotrophs and sulfate reducers shifted in relative abundance and/or composition between wetland types. Methanogens and putative denitrifying methanotrophs declined in relative abundance from freshwater to marine wetlands, whereas sulfate reducers showed the opposite trend. A four-year experimental simulation of saltwater intrusion in a pristine freshwater site and a previously saltwater-impacted site corroborated the highest sensitivity and relative increase of sulfate reducers, as well as taxon-specific sensitivity of methanogens, in response to continuously pulsing of saltwater treatment. Collectively, these results suggest that besides increased salinity, saltwater-mediated increased sulfate availability leads to displacement of methanogens by sulfate reducers even at low or temporal salt exposure. These changes of microbial composition could affect organic matter degradation pathways in coastal freshwater wetlands exposed to sea-level rise, with potential consequences, such as loss of stored soil organic carbon. 

This study offers the first investigation on the normative processes through which Chinese form impressions of others in social interaction. Using affect control theory and its archived sentiment data from China, I estimate the Chinese impression formation models with a new Bayesian method. I then compare the Chinese models to the impression formation dynamics in U.S. English. Results show cross-cultural commonality in the affective processing of cultural concepts, with determinants of impression formation processes being largely universal. Findings also reveal two cultural variations that align with patterns uncovered by comparative cross-cultural research: (1) the Chinese models show less rigidity in the definition of situation and (2) across two cultural models, the balance term has opposite effects on actor and behavior evaluation. To explore the implications of the impression models, I present a series of simulations, illustrating the predictive power of affect control theory as well as the impact of different cultural rules on social interaction.

 

Alpha-synuclein (α-syn) exhibits pathological misfolding in many human neurodegenerative disorders. We previously showed that α-syn is arginylated in the mouse brain and that lack of arginylation leads to neurodegeneration in mice.

Here, we tested α-syn arginylation in human brain pathology using newly derived antibodies in combination with Western blotting, biochemical assays, and experiments in live neurons.

We found that α-syn was arginylated in the human brain on E46 and E83, two sites previously implicated in α-syn pathology and familial cases of Parkinson’s disease. The levels of arginylation in different brain samples ranged between ~ 3% and ~ 50% of the total α-syn pool, and this arginylation nearly exclusively concentrated in the subcellular α-syn fraction that sedimented at low centrifugation speeds and appeared to be simultaneously targeted by multiple posttranslational modifications. Arginylated α-syn was less susceptible to S129 phosphorylation and pathological aggregation in neurons. The arginylation level inversely correlated with the overall α-syn levels and with patient age, suggesting a possible causal relationship between arginylation decline and α-syn-dependent neuropathology.

We propose that α-syn arginylation constitutes a potential neuroprotective mechanism that prevents its abnormal accumulation during neurodegeneration and aging in the human brain.

 

This study offers the first investigation on the normative processes through which Chinese form impressions of others in social interaction. Using affect control theory and its archived sentiment data from China, I estimate the Chinese impression formation models with a new Bayesian method. I then compare the Chinese models to the impression formation dynamics in U.S. English. Results show cross-cultural commonality in the affective processing of cultural concepts, with determinants of impression formation processes being largely universal. Findings also reveal two cultural variations that align with patterns uncovered by comparative cross-cultural research: 1) the Chinese models show less rigidity in the definition of situation; and 2) across two cultural models, the balance term has opposite effects on actor and behavior evaluation. To explore the implications of the impression models, I present a series of simulations, illustrating the predictive power of affect control theory as well as the impact of different cultural rules on social interaction. 

We review Affect Control Theory (ACT), a mathematically formalized theory that integrates sociological insights about the symbolic construction of the social order with psychological knowledge about cognitive-affective mechanisms, as a basis for equipping computational agents in social simulations with a sense of sociality. After explaining theoretical foundations and describing previous applications of ACT at the dyadic and group level, we describe a case study from an ongoing research project aimed at understanding self-organized online collaboration in software development with ACT-based social simulations.