254 research outputs found
Rural financial development, spatial spillover, and poverty reduction: evidence from China
Rural financial development is deemed essential for eliminating
poverty. In China, successive governments have initiated a series
of financial development plans to reduce poverty since the launch
of economic reform in the late 1970s. However, there is a rising
concern about whether financial development can reduce poverty
in China. This study uses a panel dataset of 30 provinces (out of
31) in mainland China from 1997 to 2015 to examine the effect
of rural financial development on poverty reduction. We employ
a spatial panel model to investigate whether rural financial development has a positive spatial spillover effect. Moreover, we use
the instrumental variable method to address the possible bidirectional causal effect between rural financial development and poverty reduction. Our study confirms that rural financial
development does reduce poverty and simultaneously widen the
urban-rural income gap. We further find that rural financial development has a positive spatial spillover effect on poverty alleviation and that the conventional panel model (e.g., fixed effects
method) may underestimate the effect of rural financial development, as it ignores the spatial spillover effect
Genome-resolved metagenomics provides insights into the microbial-mediated sulfur and nitrogen cycling in temperate seagrass meadows
The presence of seagrasses facilitates numerous microbial-mediated biogeochemical cycles, with sulfur- and nitrogen-cycling microorganisms playing crucial roles as regulators. Despite efforts to comprehend the diversity of microbes in seagrass ecosystems, the metabolic functions of these benthic microorganisms in seagrass sediments remain largely unknown. Using metagenomics, we provide insights into the sulfur- and nitrogen-cycling pathways and key metabolic capacities of microorganisms in both Z. japonica-colonized and unvegetated sediments over a seasonal period. Taxonomic analysis of N and S cycling genes revealed that δ- and γ- proteobacteria dominated the benthic sulfate-reducing bacteria, while α- and γ-proteobacteria played a significant role in the sulfur-oxidation processes. The proteobacterial lineages were also major contributors to the benthic nitrogen cycling. However, at a finer taxonomic resolution, microbial participants in different processes were observed to be highly diverse and mainly driven by environmental factors such as temperature and salinity. The gene pools of sulfur and nitrogen cycles in the seagrass sediments were dominated by genes involved in sulfide oxidation (fccA) and hydroxylamine oxidation (hao), respectively. Seagrass colonization elevated the relative abundance of genes responsible for sulfite production (phsC), hydroxylamine oxidation (hao), and nitrogen fixation (nifK), but suppressed sulfur oxidation (soxXYZ) and denitrification (nosZ and nirS). The prevalence of proteobacterial lineages functioned with versatile capabilities in both sulfur and nitrogen cycles in seagrass ecosystems, highlighting tight couplings between these processes, which was further supported by the recovery of 83 metagenome-assembled genomes (MAGs). These findings broaden our understanding of the biogeochemical processes that are mediated by microorganisms in seagrass ecosystems
Day-ahead and hour-ahead optimal scheduling for battery storage of renewable energy power stations participating in primary frequency regulation
Due to the fast response characteristics of battery storage, many renewable energy power stations equip battery storage to participate in auxiliary frequency regulation services of the grid, especially primary frequency regulation (PFR). In order to make full use of the battery capacity and improve the overall revenue of the renewable energy station, a two-level optimal scheduling strategy for battery storage is proposed to provide primary frequency regulation and simultaneously arbitrage, according to the peak-valley electricity price. The energy storage output is composed of the droop-based primary frequency regulation output and the economic output, according to the electricity price. First, day-ahead optimization defines the economic output profile and an appropriate droop coefficient, considering regulation needs, with the goal of maximizing the overall return. The scheduling result is then adjusted for hour-ahead optimization based on the updated regulation information to ensure more durable and reliable performance. Simulation results show that the proposed scheduling strategy can fully utilize the battery capacity, realize peak-valley arbitrage while assuming the obligation of primary frequency regulation of the renewable energy power station, and then improve the overall income of the power station
Imperialibacter roseus gen. nov., sp nov., a novel bacterium of the family Flammeovirgaceae isolated from Permian groundwater
A novel bacterial strain, designated P4(T), was isolated from Permian groundwater and identified on the basis of its phylogenetic, genotypic, chemotaxonomic and phenotypic characteristics. Cells were aerobic, Gram-stain-negative rods. 16S rRNA gene sequence-based phylogenetic analysis revealed that P4(T) is affiliated with the family Flammeovirgaceae in the phylum Bacteroidetes, but forms a distinct cluster within this family. The DNA G+C content of strain P4(T) was 45.2 mol%. The predominant cellular fatty acids were C-16:1 omega 6C/C-16:1 omega 7c and iso-C-15:0. MK-7 was the main respiratory quinone. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, unidentified phospholipids, an unidentified aminolipid, unidentified glycolipids and unidentified polar lipids. Based on our extensive polyphasic analysis, a novel species in a new genus, Imperialibacter roseus gen. nov., sp. nov., is proposed. The type strain of Imperialibacter roseus is P4(T) (=CICC 10659(T)=KCTC 32399(T)).A novel bacterial strain, designated P4(T), was isolated from Permian groundwater and identified on the basis of its phylogenetic, genotypic, chemotaxonomic and phenotypic characteristics. Cells were aerobic, Gram-stain-negative rods. 16S rRNA gene sequence-based phylogenetic analysis revealed that P4(T) is affiliated with the family Flammeovirgaceae in the phylum Bacteroidetes, but forms a distinct cluster within this family. The DNA G+C content of strain P4(T) was 45.2 mol%. The predominant cellular fatty acids were C-16:1 omega 6C/C-16:1 omega 7c and iso-C-15:0. MK-7 was the main respiratory quinone. The polar lipids were phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, unidentified phospholipids, an unidentified aminolipid, unidentified glycolipids and unidentified polar lipids. Based on our extensive polyphasic analysis, a novel species in a new genus, Imperialibacter roseus gen. nov., sp. nov., is proposed. The type strain of Imperialibacter roseus is P4(T) (=CICC 10659(T)=KCTC 32399(T))
Mid-late Holocene temperature and precipitation variations in the Guanting Basin, upper reaches of the Yellow River
The reconstruction of prehistoric temperature and precipitation variations in the upper reaches of the Yellow River is essential for understanding the cultural evolution of the region, but related information is sparse due to the limitations of the available proxies. Recent studies have shown that microbial glycerol dialkyl glycerol tetraethers (GDGTs) are promising tools for reconstructing mean annual temperature (MAT) and mean annual precipitation (MAP) in terrestrial deposits. In this study, we reconstructed mid-late Holocene climatic changes using GDGT distributions in a loess-paleosol sequence in the Lajia Ruins of the Neolithic Qijia Culture, Guanting Basin, in the southwestern end of the Chinese Loess Plateau. Our GDGT records show that MAP decreased from ca. 600 mm to 430 mm, while MAT decreased from 11.9 degrees C to 8.0 degrees C, during the past ca. 7000 yr, and a drastic decline in MAP (70 mm), accompanied by a 0.8 degrees C decline in MAT, occurred at 3800-3400 yr BP. Our results provide direct evidence supporting a hypothesis that the flourishing (4200-4000 yr BP) and decline (4000-3600 yr BP) of the Qijia culture (mainly based on millets cultivation) and subsequent rise of the Xindian/Kayue culture (3600-2600 yr BP), based on mixed agriculture of sheep husbandry and millets cultivation were triggered by climate change
Demographic patterns of two related desert shrubs with overlapping distributions in response to past climate changes
Numerous studies have revealed that past geological events and climatic fluctuations had profoundly affected the genetic structure and demographic patterns of species. However, related species with overlapping ranges may have responded to such environmental changes in different ways. In this study, we compared the genetic structure and population dynamics of two typical desert shrubs with overlapping distributions in northern China, Nitraria tangutorum and Nitraria sphaerocarpa, based on chloroplast DNA (cpDNA) variations and species distribution models. We sequenced two cpDNA fragments (trnH-trnA and atpH-atpI) in 633 individuals sampled from 52 natural populations. Twenty-four chlorotypes, including eight rare chlorotypes, were identified, and a single dominant haplotype (H4) widely occurred in the entire geographical ranges of the two species. There were also a few distinctive chlorotypes fixed in different geographical regions. Population structure analyses suggested that the two species had significantly different levels of total genetic diversity and interpopulation differentiation, which was highly likely correlated with the special habitat preferences of the two species. A clear phylogeographic structure was identified to exist among populations of N. sphaerocarpa, but not exist for N. tangutorum. The neutral tests, together with the distribution of pairwise differences revealed that N. tangutorum experienced a sudden demographic expansion, and its expansion approximately occurred between 21 and 7 Kya before present, while a rapid range expansion was not identified for N. sphaerocarpa. The ecological niche modeling (ENM) analysis indicated that the potential ranges of two species apparently fluctuated during the past and present periods, with obvious contraction in the Last Glacial Maximum (LGM) and recolonization in the present, respectively, comparing to the Last Interglacial (LIG). These findings suggest that the two species extensively occurred in the Northwest of China before the Quaternary, and the current populations of them originated from a few separated glacial refugia following their habitat fragmentation in the Quarternary. Our results provide new insights on the impact of past geological and climatic fluctuations on the population dynamics of desert plants in northwestern China, and further enforce the hypothesis that there were several independent glacial refugia for these species during the Quaternary glaciations
Hyperinsulinemia Drives Diet-Induced Obesity Independently of Brain Insulin Production
SummaryHyperinsulinemia is associated with obesity and pancreatic islet hyperplasia, but whether insulin causes these phenomena or is a compensatory response has remained unsettled for decades. We examined the role of insulin hypersecretion in diet-induced obesity by varying the pancreas-specific Ins1 gene dosage in mice lacking Ins2 gene expression in the pancreas, thymus, and brain. Age-dependent increases in fasting insulin and β cell mass were absent in Ins1+/−:Ins2−/− mice fed a high-fat diet when compared to Ins1+/+:Ins2−/− littermate controls. Remarkably, Ins1+/−:Ins2−/− mice were completely protected from diet-induced obesity. Genetic prevention of chronic hyperinsulinemia in this model reprogrammed white adipose tissue to express uncoupling protein 1 and increase energy expenditure. Normalization of adipocyte size and activation of energy expenditure genes in white adipose tissue was associated with reduced inflammation, reduced fatty acid spillover, and reduced hepatic steatosis. Thus, we provide genetic evidence that pathological circulating hyperinsulinemia drives diet-induced obesity and its complications
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