G.A. Cohen’s Influence on Chinese Academia

This research note surveys G.A. Cohen’s influence on Chinese academia by looking at four of his contributions, namely: applying analytical methods in Marxist studies; providing a sober understanding of the relationship between markets and socialism; defending and upholding socialist egalitarianism; and summoning Marxists to engage in moral justification of socialism. Cet note de recherche offre un aperçu de l’importance de G.A. Cohen dans le monde universitaire chinois en regardant quatre de ses contributions:en utilisant des méthodes analytiques dans des études marxistes; en offrant un éclairage sobre des relations entre les marchés et le socialisme; en défendant et en soutenant l’égalitarisme socialiste; et en demandant aux marxistes de s’engager dans les justifications morales du socialisme

Changing sources and burial of organic carbon in the Chukchi Sea sediments with retreating sea ice over recent centuries

Decreasing sea ice extent in summer caused by climate change is affecting the carbon cycle of the Arctic Ocean. In this study, surface sediments across the western Arctic Ocean are investigated to characterize sources of sedimentary organic carbon (OC). Bulk organic parameters (total organic carbon, total nitrogen, &delta;13Corg and &delta;15N) combined with molecular organic biomarkers (e.g., sterols and highly branched isoprenoids (HBIs)) are applied to distinguish between sympagic, pelagic, and terrestrial OC. Furthermore, downcore profiles of these parameters were also generated from the Chukchi Sea R1 core (74&deg; N) to evaluate changes in the relative contribution of these three components of sedimentary OC over the last 200 years with decreasing sea ice. Our data evidence that from 1820s to 1930s, prevailing high and variable sea ice cover inhibited in situ primary production resulting in prominent land-derived material stored in sediments. From 1930s to 1980s, with the gradual decline of sea ice, primary production increased progressively. The ratio of sympagic and pelagic OC began to rise to account for a larger portion of sedimentary OC. Since 1980s, accelerated sea ice loss led to enhanced primary production, stabilizing over the last decades due to freshwater induced surface ocean stratification in summer.</p

Advances in Chinese and international biogeochemistry research in the western Arctic Ocean: a review

Over the past decades, the Arctic Ocean has experienced rapid warming under climate change, which has dramatically altered its physical and biogeochemical properties. Reduction in the sea-ice cover is one of the most important driving forces of biogeochemical changes in the Arctic Ocean. Between 1999 and 2016, seven Chinese National Arctic Research Expeditions have taken place in the Bering and Chukchi seas, allowing assessment of the biogeochemical response of the western Arctic Ocean to global warming. Herein, we summarize advances in Chinese and international marine biogeochemistry research in the western Arctic Ocean, reviewing results from the Chinese expeditions and highlighting future trends of biogeochemistry in the Pacific Arctic region. The findings reported in this paper contribute towards a better understanding of water masses, greenhouse gases, nutrients, ocean acidification, and organic carbon export and burial processes in this region

Date DEDICATION

Science Department at the University of Georgia. I would like to take this opportunity to thank Naval Research Laboratory (NRL) for the great cooperation efforts in this project and Iona Technologies for donating OrbixWeb software. I am extremely thankful to my major advisor, Dr. Amit Sheth, for his invaluable guidance and encouragement throughout my entire research and academic years. I am also thankful to Dr. Krzysztof Kochut and Dr. John Millor for their constant advice and help with my thesis. I would also like to thank all the excellent people in the LSDIS Lab, especially Dr. Ismailcem Budak Arpinar, Dr. Mizuho Iwaihara, Zongwei Luo, Antonio Jorge Cardoso, and Yufeng Chen, whose help and encouragement have been a source of optimism whenever I am high or low. In addition, my special thanks are extended to all my friends for their kind support for me through the years in Athens, GA. Finally, I am sincerely grateful to my parents and Haibei who have always been encouraging and supporting me, and have lightened every day of my life. They are the reason I could success. v TABLE OF CONTENTS v

Sources of organic matter in Changjiang (Yangtze River) bed sediments: Preliminary insights from organic geochemical proxies

Insight into the content and composition of organic carbon (OC) in river systems contributes to our understanding of the global carbon cycle. The Changjiang (Yangtze River) plays a significant role in global carbon and hydrological cycles, as it is an important supplier of sediment, nutrients and OC to the East China Sea. To provide a preliminary insight into the source of OC transported by the Changjiang, we analyzed bulk (grain size, organic carbon content, δ13C), and molecular (lignin phenols, branched and isoprenoid GDGTs) characteristics of organic matter in bed sediments at eight locations along the river. The δ13C values and lignin phenol composition indicate that the OC originates from a mixture of primarily soils and plants. Comparison between branched GDGT (br GDGT) distributions in riverbed sediments and those in the different soil types in the drainage basin indicate that the br GDGT signal in the upper reaches is largely derived from soils from the Qinghai-Tibet Plateau. Downstream changes in br GDGT distributions can be linked to subsequent input of local soil material. The observed variation in br GDGT composition along the river implies that a portion of the OC may be oxidized or replaced by the local input during transit. Although the relationship between δ13C and lignin phenol composition indicates that the contribution of phytoplankton is limited, comparison of GDGT ratios (GDGT-0:crenarchaeol, iso GDGTs:br GDGTs, BIT index) for the sediments and surrounding soils indicates that at least part of the iso GDGTs has an aquatic origin. Overall, the downstream evolution of br GDGTs in the Changjiang implies that their use as paleoclimate proxy in downcore applications will likely yield a local, rather than a basin-integrated continental climate record

Effects of Diabetic Hyperglycemia on Central Ang-(1-7)-Mas-R-nNOS Pathways in Spontaneously Hypertensive Rats

Background/Aims: Hypertension is a major cause of stroke, and diabetes can increase incidence of this disease. We determined the role played by central angiotensin-(1-7) [Ang-(1-7)] pathway in modulating spontaneously hypertension with diabetic hyperglycemia. Methods: Western Blot analysis and ELISA were used to determine the protein expression of Ang-(1-7) and its signal pathway Mas-R-nNOS in the cerebral cortex and hippocampus of spontaneously hypertensive rats (SHR) and control animals. In a subset of animals, diabetic hyperglycemia was induced by systemic injection of streptozotocin (STZ). We analyzed a relationship between the levels of central Ang-(1-7) and plasma brain natriuretic peptide (BNP) indicating a risk of ischemic stroke. We further examined the effects of Ang-(1-7) on arterial blood pressure. Results: Our findings demonstrated for the first time that administration of STZ 1) attenuates the levels of Ang-(1-7) in the cerebral cortex and hippocampus, which are closely linked to plasma BNP; and 2) leads to downregulation of central Ang-(1-7)-Mas-R-nNOS pathways. Notably, STZ has greater effects in SHR. Additionally, inhibition of oxidative stress can largely improve downregulation of Ang-(1-7) in diabetic SHR. Moreover, central stimulation of Ang-(1-7) pathway or a blockade of oxidative stress improves systolic blood pressure in diabetic SHR. Conclusions: The Ang-(1-7) signaling pathway is engaged in the adaptive mechanisms associated with diabetic hypertension, suggesting that enhancing Ang-(1-7)-Mas-R-nNOS system is likely to be beneficial in preventing against cardiovascular and cerebrovascular dysfunction and vulnerability related to spontaneously hypertension, particularly to diabetic hypertension

Molecular Environment Modulates Conformational Differences between Crystal and Solution States of Human β‑Defensin 2

Human β-defensin 2 is a cysteine-rich antimicrobial peptide. In the crystal state, the N-terminal segment (residues 1–11) exhibits a helical conformation. However, a truncated form, with four amino acids removed from the N-terminus, adopts nonhelical conformations in solution, as shown by NMR. To explore the molecular origins of these different conformations, we performed Hamiltonian replica exchange molecular dynamics simulations of the peptide in solution and in the crystal state. It is found that backbone hydration and specific protein–protein interactions are key parameters that determine the peptide conformation. The helical conformation in the crystal state mainly arises from reduced hydration as well as a salt bridge between the peptide and a symmetry-related neighboring monomer in the crystal. When the extent of hydration is reduced and the salt bridge is reintroduced artificially, the peptide is successfully folded back to the helical conformation in solution. The findings not only shed light on the development of accurate force field parameters for protein molecules but also provide practical guidance in the design of functional proteins and peptides

Structural Characterization and Biological Activity of Polysaccharides from Stems of Houttuynia cordata

In this study, water-soluble natural polysaccharides were extracted from the stems of Houttuynia cordata Thunb (HCPS). The optimization of the hot water extraction process using response surface methodology (RSM), and the extraction factors, were analyzed by multiple stepwise regression analysis and Pearson analysis. Then, the structural characterization and biological activity of the HCPS were investigated. The results indicated that the maximum extraction yield (2.43%) of the HCPS was obtained at the optimal condition (extraction temperature for 90 &deg;C, extraction time for 5 h, solid-liquid ratio for 1:30 g/mL). The extraction temperature was determined to be the primary factor influencing the extraction yield. The HCPS molecules had an average molecular weight of 8.854 &times; 103&thinsp;kDa and were primarily of mannose (Man), rhamnose (Rha), glucuronic acid (GlcA), galacturonic acid (GalA), glucose (Glc), and xylose (Xyl). In addition, the backbone of the HCPS might consist of &rarr;6)-&alpha;-d-Glcp-(1&rarr; and &rarr;6)-&beta;-d-GalpA-(1&rarr;. The HCPS had no triple-helix structure. The scanning electron microscopy (SEM) results showed that the HCPS presented a smooth and uniform appearance, and some sheet and chain structures existed. Moreover, the HCPS exhibited significant anti-oxidant activity and inhibited the activity of &alpha;-amylase and &alpha;-glucosidase. These findings showed that HCPS might be developed into a potential material for hypoglycemia, and provides a reference for the development of Houttuynia cordata polysaccharide applications in food

Metabolic Profiling to Identify the Latent Infection of Strawberry by

In plant-pathogen interaction systems, plant metabolism is usually agitated in the early stages of infection and much before visible symptoms appear. To identify the latent infection of strawberry by Botrytis cinerea by metabolome profiling, a metabolomics method based on gas chromatography and mass spectrometry was applied to identify the affected metabolites and discriminate diseased plants from healthy ones. An orthogonal partial least squares (OPLS) score plot showed that the metabolic profiling well separated B. cinerea -infected strawberry plants at 2, 5, and 7 days after infection from non-infected healthy plants. Combined analysis of variance (ANOVA) and OPLS analysis revealed candidate biomarkers of plant resistance and of infection and expansion of the pathogen in the plants. Among them, hexadecanoic acid, octadecanoic acid, sucrose, β-lyxopyranose, melibiose, and 1,1,4a-Trimethyl-5,6-dimethylenedecahydronaphthalene were closely related to the early stage of disease development when symptoms were not visible. A discrimination method that could distinguish Botrytis gray mold diseased strawberry plants from healthy ones was established based on the partial least squares discriminant analysis (PLS-DA) model with a correct recognition accuracy of 100%. This research offers a good application of metabolome profiling for early diagnosis of plant disease and interaction mechanism exploration