scholarly journals Rural Migration and Urbanization in China: Historical Evolution and Coupling Pattern

2020 ◽  
Vol 12 (18) ◽  
pp. 7307 ◽  
Author(s):  
Yuanzhi Guo ◽  
Weifeng Qiao
Keyword(s):  
Spatial Pattern ◽  
Growth Rates ◽  
Socioeconomic Development ◽  
Rapid Development ◽  
Development Stage ◽  
Annual Growth ◽  
Spatial Distance ◽  
Rural Migration ◽  
Spatial Inequalities ◽  
Urbanization In China

Using a population dataset of China, this study analyzes the spatial pattern of rural migration and urbanization and their coupling coordination relationship and investigates the causes of their spatial heterogeneity. Results show that rural migration and urbanization from 1978 to 2017 can be divided into three stages, i.e., the recovery and development stage, the stable and rapid development stage, and the stage of promoting the citizenization of the rural migrant population. From 2000 to 2010, counties with average annual growth rates of the ratio of rural migration (GRM) ranging from 0 to 5.00% showed a spatial pattern of ubiquitous distribution, while there were significant spatial inequalities in the average annual growth rates of the urbanization rate of the residential population (GUR) and hukou-registered population (GUH). Since urbanization and rural migration are two synergistic processes, coupling coordination degrees (CCDs) between GRM and GRU as well as GRM and GUH were generally between 0.60 and 0.80. Due to the gaps in socioeconomic development, spatial distance, and the policy system, they also showed regional heterogeneity, and there were notable differences in CCD between rural migration and urbanization of residential and hukou-registered populations. Finally, we propose that China should implement targeted and people-oriented measures to guide rural migration, promote new-type urbanization, and achieve integrated urban–rural development.

scholarly journals Quantifying the effect of local shelter on tree growth patterns within upper treeline ecotones in the Bighorn Mountans of Wyoming.

2017 ◽  
Author(s):  
◽  
Nathan Mackley
Keyword(s):  
Spatial Pattern ◽  
Tree Growth ◽  
Growth Rates ◽  
Growth Patterns ◽  
Tree Regeneration ◽  
Annual Growth ◽  
Limiting Factor ◽  
Spatial Pattern Analysis ◽  
Tree Establishment ◽  
Moisture Retention

On Bruce Mountain in the Bighorn Mountains of Wyoming, the upper treeline ecotone has advanced upslope since 1970 and to the highest extent in at least the past 210 years. However, the mechanisms facilitating tree establishment and treeline advance during this time were distinctly different between north and south-facing slope aspects. Tree regeneration on the south-facing slope was predominantly confined to microsites in the sheltered lee of boulders where more shade, moisture retention, and protection from the wind exist. Trees on the north-facing slope colonized open alpine tundra and facilitated continued regeneration clustered in close proximity to these trees. Thus, while patterns of tree establishment and treeline advance are well understood, it remains unknown whether differences in tree growth exist between these two sites. This is relevant as other studies suggest that favorable climatic conditions for tree establishment do not correspond with periods of high annual growth rates for trees at upper treeline. The goal of this research was to determine whether distinct patterns of tree establishment influence annual growth rates of these trees. To address this, I calculated basal area increment (BAI) for all trees positioned above the upper forest border. Surprisingly, annual growth rates and corresponding BAI values were almost identical between sites since 1970. These results suggest that tree establishment may be more of a critical limiting factor to upper treeline advance than tree growth because consistent growth patterns were found irrespective of spatial pattern on opposite slope aspects. From spatial pattern analysis, tree establishment on the northern slope adheres to the known biological preferences for each of the treeline species; while the pattern of establishment on the southern slope is overridden by the availability of favorable sites (i.e. in the lee of boulders) providing needed shade and moisture retention. As the treeline is a temperature and moisture-limited ecotone, there are observed differences along the elevational gradient within the site and between species that grow open and have a higher drought tolerance compared to those that rely on shade and neighboring trees.

scholarly journals Recent Advances in Phase-Sensitive Optical Time Domain Reflectometry (Ф-OTDR)

2021 ◽  
Vol 11 (1) ◽  
pp. 1-30
Author(s):  
Yunjiang Rao ◽  
Zinan Wang ◽  
Huijuan Wu ◽  
Zengling Ran ◽  
Bing Han
Keyword(s):  
Fiber Optics ◽  
Time Domain ◽  
Acoustic Waves ◽  
Rapid Development ◽  
Development Stage ◽  
Time Domain Reflectometry ◽  
Rayleigh Backscattering ◽  
Optical Time Domain Reflectometry ◽  
Phase Sensitive ◽  
Optical Time

AbstractPhase-sensitive optical time domain reflectometry (Ф-OTDR) is an effective way to detect vibrations and acoustic waves with high sensitivity, by interrogating coherent Rayleigh backscattering light in sensing fiber. In particular, fiber-optic distributed acoustic sensing (DAS) based on the Ф-OTDR with phase demodulation has been extensively studied and widely used in intrusion detection, borehole seismic acquisition, structure health monitoring, etc., in recent years, with superior advantages such as long sensing range, fast response speed, wide sensing bandwidth, low operation cost and long service lifetime. Significant advances in research and development (R&D) of Ф-OTDR have been made since 2014. In this review, we present a historical review of Ф-OTDR and then summarize the recent progress of Ф-OTDR in the Fiber Optics Research Center (FORC) at University of Electronic Science and Technology of China (UESTC), which is the first group to carry out R&D of Ф-OTDR and invent ultra-sensitive DAS (uDAS) seismometer in China which is elected as one of the ten most significant technology advances of PetroChina in 2019. It can be seen that the Ф-OTDR/DAS technology is currently under its rapid development stage and would reach its climax in the next 5 years.

Spurious Persistence and Unit Roots due to Seasonal Differencing: The Case of Inflation Rates / Künstliche Persistenz und Einheitswurzeln infolge saisonaler Differenzen: Das Beispiel Inflationsraten

2005 ◽  
Vol 225 (4) ◽  
Author(s):  
Uwe Hassler ◽  
Matei Demetrescu
Keyword(s):  
Growth Rates ◽  
Unit Root ◽  
Unit Roots ◽  
Annual Growth ◽  
Seasonal Growth ◽  
Seasonal Differences ◽  
Inflation Rates ◽  
European Economies ◽  
Seasonal Data

SummaryStudying annual growth rates (seasonal differences) in case of seasonal data produces much more persistence, autocorrelation and stronger evidence in favour of a unit root than analyzing seasonal growth rates (ordinary differences). First, this statement is quantified theoretically. Second, it is supported experimentally with simulations, and, finally, it is empirically illustrated with quarterly GDP deflators from 7 European economies.

scholarly journals Transcriptome analysis of lateral buds from Phyllostachys edulis rhizome during germination and early shoot stages

2020 ◽  
Author(s):  
Yuting Shou ◽  
Yihua Zhu ◽  
Yulong Ding
Keyword(s):  
Signaling Pathways ◽  
High Throughput Sequencing ◽  
Stem Elongation ◽  
Rapid Development ◽  
Development Stage ◽  
Fast Growth ◽  
Moso Bamboo ◽  
Phyllostachys Edulis ◽  
Lateral Buds ◽  
Meristem Development

Abstract Background: The vegetative growth is an important stage for plants when they conduct photosynthesis, accumulate and collect all resources needed and prepare for reproduction stage. Bamboo is one of the fastest growing plant species. The rapid growth of Phyllostachys edulis results from the expansion of intercalary meristem at the basal part of nodes, which are differentiated from the apical meristem of rhizome lateral buds. However, little is known about the major signaling pathways and players involved during this rapid development stage of bamboo. To study this question, we adopted the high-throughput sequencing technology and compared the transcriptomes of Moso bamboo rhizome buds in germination stage and late development stage. Results: We found that the development of Moso bamboo rhizome lateral buds was coordinated by multiple pathways, including meristem development, sugar metabolism and phytohormone signaling. Phytohormones have fundamental impacts on the plant development. We found the evidence of several major hormones participating in the development of Moso bamboo rhizome lateral bud. Furthermore, we showed direct evidence that Gibberellic Acids (GA) signaling participated in the Moso bamboo stem elongation. Conclusion: Significant changes occur in various signaling pathways during the development of rhizome lateral buds. It is crucial to understand how these changes are translated to Phyllostachys edulis fast growth. These results expand our knowledge on the Moso bamboo internodes fast growth and provide research basis for further study.

Early Life History of Fishes in the San Francisco Estuary and Watershed

2004 ◽  
Keyword(s):  
Growth Rate ◽  
San Francisco ◽  
Striped Bass ◽  
Growth Rates ◽  
Early Life History ◽  
San Francisco Estuary ◽  
Annual Growth ◽  
Factors Affecting ◽  
Juvenile Abundance ◽  
History Of

<em>Abstract.</em>—We investigated factors affecting growth of larval striped bass <em>Morone saxatilis </em>in the San Francisco Estuary from 1984 to 1993. We estimated ages and growth rates of larval striped bass from daily otolith increments. Mean annual growth rates of 6–14 mm standard length striped bass varied from 0.13 to 0.27mm/d, the lowest rate occurring in 1989 and the highest in 1992. The 1989 growth rate was significantly lower than all other years, and growth rates for 1992 and 1993 were significantly higher than all other years, but did not differ from one another. Differences in annual growth rates apparently were due mainly to differences in mean annual prey densities because growth rate increased as prey density increased. Compared to both laboratory measured growth rates and growth rates of field-caught Chesapeake Bay larvae, growth rates from the San Francisco Estuary appeared to be high for the food available, indicating that larvae can grow at relatively high rates even at low prey densities. Correlation analyses did not support density-dependent control of growth rates. Growth rate was not significantly related to mean annual conductivity, water temperature, mortality rates, or the juvenile abundance index, but was significantly and positively correlated with densities of 1-mm length-groups of 9–14-mm striped bass.

scholarly journals Review of Biological and Chemical Health Risks Associated with Pork Consumption in Vietnam: Major Pathogens and Hazards Identified in Southeast Asia

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Meghan A. Cook ◽  
Pham Duc Phuc
Keyword(s):  
Health Risks ◽  
Socioeconomic Development ◽  
Trichinella Spiralis ◽  
Rapid Development ◽  
Taenia Solium ◽  
Streptococcus Suis ◽  
Foodborne Illness ◽  
Value Chains ◽  
Potential Health ◽  
Pork Consumption

Foodborne illness is a difficult public health burden to measure, with accurate incidence data usually evading disease surveillance systems. Yet, the global scope of foodborne disease and its impacts on socioeconomic development make it an important health risk to address, particularly in low- and middle-income countries. In Vietnam, rapid development has seen large-scale commercial operations rise to coexist amongst traditional value chains in the food landscape, most of which operates outside of a domestic food safety network. Rapid socioeconomic development has also seen an increase in meat consumption, with pork being the most consumed meat product nationally. Expanding pork value chains, and the increasing diversity of actors within them, facilitates the growth and propagation of hazards which are passed onto Vietnamese consumers. In order to guide illness prevention and governance efforts, this review was conducted to examine health risks associated with pork consumption in Vietnam. Synthesis of the available literature provided evidence that Salmonella spp. bacteria are a major cause of foodborne illness from Vietnamese pork products. However, contaminants of global concern, including Salmonella spp. and Trichinella spiralis, occur alongside those considered neglected tropical diseases, such as Taenia solium. Infections and complications associated with ingestion of Streptococcus suis bacteria are also an issue, with Streptococcus suis infections usually limited to occupational infections amongst meat handlers in modernised value chains. A risk factor underscoring transmission of Trichinella spiralis, Taenia solium, and Streptococcus suis in Vietnam that emerges from the literature is the consumption of dishes containing raw or undercooked pork. Available data indicates that infections associated with raw pork consumption disproportionately affect men and people in regional mountainous areas of northwest Vietnam, where many of Vietnam’s ethnic minority communities reside. In addition, epidemiological data from recorded disease outbreaks that result from raw pork consumption demonstrate that these outbreaks usually follow major sociocultural events such as weddings, funerals, and Lunar New Year celebrations. Potential health impacts resulting from residues of antibiotics and heavy metals are also cause for concern, though the direct links between chemical contaminants in food and the development of disease are difficult to conclusively deduce.

scholarly journals Regions of the Russian Arctic Zone: State and Problems at the Beginning of the New Development Stage

2018 ◽  
Vol 7 (3.14) ◽  
pp. 369 ◽  
Author(s):  
Lyubov Vasilievna Larchenko ◽  
Roman Aleksandrovich Kolesnikov
Keyword(s):  
Socioeconomic Development ◽  
Regional Policy ◽  
Raw Materials ◽  
Development Stage ◽  
The State ◽  
The Arctic ◽  
Russian Arctic ◽  
Arctic Zone ◽  
Arctic Regions ◽  
Regions Of Russia

In recent years, a new market trading in cryptocurrencies and instruments based on them has been formed. The market of This paper The goal of the study is to analyze the degree of differentiation of the Arctic regions of Russia by the key indicators of socioeconomic development, dependence of their economic development on the raw materials industries, which should be accounted to shape an efficient regional policy by the state and achieve the strategic goals for the reclamation and development of the Russian Arctic zone. The methodology of the study is based on a systematic approach to assessing the socioeconomic and sectoral differentiation of the Arctic regions of Russia. A set of general scientific and special research methods was used. The conducted analysis indicates that all the Arctic regions under study have a narrow raw materials nature of the economy, the sectoral structure is poorly differentiated. The policy of equalizing the per capita income and the cost of living in the Arctic regions with other regions of Russia largely determined the outflow of population from the northern regions. The state regional policy in relation to the Arctic regions should take into account their heterogeneity in order to achieve the results outlined in the strategic documents. 

scholarly journals Can We Measure a COVID-19-Related Slowdown in Atmospheric CO2 Growth? Sensitivity of Total Carbon Column Observations

2020 ◽  
Vol 12 (15) ◽  
pp. 2387 ◽  
Author(s):  
Ralf Sussmann ◽  
Markus Rettinger
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Measurement Precision ◽  
Annual Growth ◽  
Total Carbon ◽  
Mathematical Framework ◽  
Single Measurement ◽  
Synoptic Variability ◽  
Concentration Changes ◽  
The Impact

The COVID-19 pandemic is causing projected annual CO2 emission reductions up to −8% for 2020. This approximately matches the reductions required year on year to fulfill the Paris agreement. We pursue the question whether related atmospheric concentration changes may be detected by the Total Carbon Column Observing Network (TCCON), and brought into agreement with bottom-up emission-reduction estimates. We present a mathematical framework to derive annual growth rates from observed column-averaged carbon dioxide (XCO2) including uncertainties. The min–max range of TCCON growth rates for 2012–2019 was [2.00, 3.27] ppm/yr with a largest one-year increase of 1.07 ppm/yr for 2015/16 caused by El Niño. Uncertainties are 0.38 [0.28, 0.44] ppm/yr limited by synoptic variability, including a 0.05 ppm/yr contribution from single-measurement precision. TCCON growth rates are linked to a UK Met Office forecast of a COVID-19-related reduction of −0.32 ppm yr−2 in 2020 for Mauna Loa. The separation of TCCON-measured growth rates vs. the reference forecast (without COVID-19) is discussed in terms of detection delay. A 0.6 [0.4, 0.7]-yr delay is caused by the impact of synoptic variability on XCO2, including a ≈1-month contribution from single-measurement precision. A hindrance for the detection of the COVID-19-related growth rate reduction in 2020 is the ±0.57 ppm/yr uncertainty for the forecasted reference case (without COVID-19). Only assuming the ongoing growth rate reductions increasing year-on-year by −0.32 ppm yr−2 would allow a discrimination of TCCON measurements vs. the unperturbed forecast and its uncertainty—with a 2.4 [2.2, 2.5]-yr delay. Using no forecast but the max–min range of the TCCON-observed growth rates for discrimination only leads to a factor ≈2 longer delay. Therefore, the forecast uncertainties for annual growth rates must be reduced. This requires improved terrestrial ecosystem models and ocean observations to better quantify the land and ocean sinks dominating interannual variability.

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