Detection of the dispersion and residence of volcanic SO2⁠ and sulfate aerosol from Nabro in 2011

Continuous detection of dispersion and residence of volcanic plumes in troposphere and lower stratosphere is vitally important for improving the understanding on the role of volcano eruptions in climate change. We report a 3-month continuous detection of dispersion and residence of volcanic plumes in the troposphere and stratosphere generated from the volcanic SO2 erupted by Nabro in Eritrea on June 12th, 2011 observed by the OMI sensor. The background SO2 concentration of 3 different height layers in troposphere and lower stratosphere were estimated by the 3-year-average daily concentration of monthly SO2 in 2005, 2007 and 2013, when there were no large explosive volcanic eruptions occurring. We also traced the diffusion path and the concentration of volcanic SO2 for the first 3 months after Nabro's eruption, and detected the appearance and dissipation of sulfate aerosols, which is a product converted from volcanic SO2. The results show that after Nabro erupted on June 12th, the volcanic plumes spread to middle latitudes (30 degrees N -60 degrees N) of Northern Hemisphere and loading by westerly jet. The volcanic SO2 in middle troposphere layer (TRM) and lower troposphere layer (TRL) stopped eastward spreading, and dissipated over the western Pacific Ocean on June 23rd. On June 26th, the volcanic SO2 in upper troposphere and lower stratosphere (STL) reached Mexico in Central America, and almost encircled the low latitudes and parts of middle latitudes. On June 28th, the volcanic SO2 plume showed an even distribution in STL. 37 days after the eruption, the volcanic SO2 in STL encircled the Northern Hemisphere evenly, sulfate aerosols in STL largely covered the low and middle latitudes and the daily concentration of SO2 was still higher than the background value. One month after the eruption, the global mean daily concentration of SO2 dropped to the normal value, but the daily concentration of SO2 and sulfate aerosols in low latitudes remained high, and dissipated not earlier than 3 months after the eruption of Nabro.Peer reviewe

Rising grain prices in response to phased climatic change during 1736-1850 in the North China Plain

Grain price volatility during historical periods is regarded as an important indicator of the impact of climate change on economic system, as well as a key link to adjust food security and social stability. The present study used the wheat prices in Baoding Prefecture, China, during 1736-1850 to explore connections between climatic transition and grain price anomalies in the North China Plain. The main findings were as follows: (1) The grain price change showed an apparent correspondence with climatic transition. The period 1781-1820 was a transition phase, with more extremes and decreased precipitations when the climate shifted from a warm phase to a cold one. Corresponding with the climatic transition, the grain price during 1781-1820 was characterized by that the mean of the original grain price series was significantly higher (lower) than the previous (later) phase, and the variance and anomaly amplitude of the detrended grain price series was the highest during 1736-1850. (2) The correspondence between grain price extremes and drought events occurred in phases. Five grain price extremes occurred following drought events during 1781-1810, while extreme droughts were the direct cause of the grain price spike during 1811-1820. (3) Social stability affected by climate change also played an important role in the grain price spike between 1811 and 1820. Paralleling the pathway of "precipitation-grain production-grain price", climate change could have an impact on grain price via the pathway of "precipitation-grain production-grain price-famine-uprising-grain price", as shown during the Tianli Uprising in 1813. These findings could contribute to an improved understanding of the interaction between climate change and human society during the historical period.Peer reviewe

Genome-Wide Characterization and Analysis of bHLH Transcription Factors Related to Anthocyanin Biosynthesis in Cinnamomum camphora ('Gantong 1')

Cinnamomum camphora is one of the most commonly used tree species in landscaping. Improving its ornamental traits, particularly bark and leaf colors, is one of the key breeding goals. The basic helix-loop-helix (bHLH) transcription factors (TFs) are crucial in controlling anthocyanin biosynthesis in many plants. However, their role in C. camphora remains largely unknown. In this study, we identified 150 bHLH TFs (CcbHLHs) using natural mutant C. camphora 'Gantong 1', which has unusual bark and leaf colors. Phylogenetic analysis revealed that 150 CcbHLHs were divided into 26 subfamilies which shared similar gene structures and conserved motifs. According to the protein homology analysis, we identified four candidate CcbHLHs that were highly conserved compared to the TT8 protein in A. thaliana. These TFs are potentially involved in anthocyanin biosynthesis in C. camphora. RNA-seq analysis revealed specific expression patterns of CcbHLHs in different tissue types. Furthermore, we verified expression patterns of seven CcbHLHs (CcbHLH001, CcbHLH015, CcbHLH017, CcbHLH022, CcbHLH101, CcbHLH118, and CcbHLH134) in various tissue types at different growth stages using qRT-PCR. This study opens a new avenue for subsequent research on anthocyanin biosynthesis regulated by CcbHLH TFs in C. camphora

Genetic Dissection of Local and Systemic Responses in States of Perturbed Iron Balance

Iron balance is essential for health. Iron deficiency can impair multiple biological processes and, when severe, restrict red blood cell production, resulting in iron deficiency anemia. Excess iron, on the other hand, can catalyze the generation of harmful reactive oxygen species, leading to tissue damage and organ failure. Because at least 1 billion people worldwide exhibit altered iron balance, understanding iron pathophysiology has broad implications for global health. In this thesis, I use genetic approaches in mouse models and tissue culture systems to dissect local and systemic responses in states of perturbed iron balance. The first part of this thesis defines local responses in the liver, the major iron depot of the body, after blood loss. We showed that NCOA4 (nuclear receptor coactivator 4), a widely expressed intracellular protein, mediates the mobilization of hepatic iron stores after blood loss. Additionally, we provided evidence that the expression of NCOA4 is regulated by hypoxia inducible factor (HIF) in cells of hepatic origin. Because HIF stability is regulated by both oxygen and iron levels, our findings suggest a novel mechanism by which hypoxia and iron deficiency may modulate NCOA4 expression to impact iron homeostasis. The second part of my thesis work focuses on systemic responses during iron deficiency. We showed that mice with chronic iron deficiency anemia exhibit elevated circulatory levels of FGF23 (fibroblast growth factor 23), a hormone that regulates systemic phosphate homeostasis. By utilizing a genetic mouse model that allows us to track sites of FGF23 production, we revealed that a subset of cells in the bone marrow have increased Fgf23 expression in iron deficiency anemia. As prior studies have indicated that low serum iron levels are associated with increased FGF23 levels in humans, our study may have implications for understanding FGF23 regulation in clinical states with dysregulated iron homeostasis. In summary, this body of work elucidates specific local and systemic responses in states of perturbed iron balance. By expanding our understanding of iron pathophysiology, knowledge gained from these studies has relevance to the development of novel therapies for humans patients with altered iron balance