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Author(s):  
Dongfan Xu ◽  
Jialong Zhang ◽  
Rui Bao ◽  
Yi Liao ◽  
Dongyang Han ◽  
...  

Understanding the drivers of forest aboveground biomass (AGB) is essential to further understanding the forest carbon cycle. In the upper Yangtze River region, where ecosystems are incredibly fragile, the driving factors that make AGB changes differ from other regions. This study aims to investigate AGB’s spatial and temporal variation of Pinus densata in Shangri-La and decompose the direct and indirect effects of spatial attribute, climate, stand structure, and agricultural activity on AGB in Shangri-La to evaluate the degree of influence of each factor on AGB change. The continuous sample plots from National Forest Inventory (NFI) and Landsat time series were used to estimate the AGB in 1987, 1992, 1997, 2002, 2007, 2012, and 2017. The structural equation model (SEM) was used to analyze the different effects of the four factors on AGB based on five scales: entire, 1987–2002, 2007–2017, low population density, and high population density. The results are as follows: (1) The AGB of Pinus densata in Shangri-La decreased from 1987 to 2017, with the total amount falling from 9.52 million tons to 7.41 million tons, and the average AGB falling from 55.49 t/ha to 40.10 t/ha. (2) At different scales, stand structure and climate were the drivers that directly affect the AGB change. In contrast, the agricultural activity had a negative direct effect on the AGB change, and spatial attribute had a relatively small indirect effect on the AGB change. (3) Analyzing the SEM results at different scales, the change of the contribution of the agricultural activity indicates that human activity is the main negative driver of AGB change in Shangri-La, especially at the high population density region. In contrast, the change of the contribution of the stand structure and climate indicates that the loss of old trees has an important influence on the AGB change. Forest resources here and other ecologically fragile areas should be gradually restored by adhering to policies, such as strengthening forest protection, improving forest stand quality, and limiting agricultural production activities.


Author(s):  
V. A. Zubakin ◽  
◽  
E. V. Zubakina ◽  
A. V. Klenova ◽  
D. S. Vodolazova ◽  
...  

The crested auklet is a medium-sized planktivorous seabird of the Alcidae family with complex social behavior, one of the interesting forms of which is the formation of club pairs in addition to existing breeding pairs. The occurrence of club pairs in this species was studied on the Talan Island (Sea of Okhotsk) in 1988-1989, when the colony was in a good condition, and in 2008-2015, when its population decreased several times. The research showed that the proportion of individuals with club partners is higher in a high-population period (35 %) and lower in a low-population period (18 %); the differences, however, are not significant. In both study periods, from 73% (1988-1989) to 80 % (2008-2015) individuals were consistent in following the chosen strategy of forming or not forming club pairs for at least two seasons. The presence of club pairs seems to facilitate the change of mate in the next breeding season, but club mates then become partners relatively seldom.


Author(s):  
V. A. Zubakin ◽  
◽  
E. V. Zubakina ◽  
A. V. Klenova ◽  
D. S. Vodolazova ◽  
...  

The crested auklet is a medium-sized planktivorous seabird of the Alcidae family with complex social behavior, one of the interesting forms of which is the formation of club pairs in addition to existing breeding pairs. The occurrence of club pairs in this species was studied on the Talan Island (Sea of Okhotsk) in 1988-1989, when the colony was in a good condition, and in 2008-2015, when its population decreased several times. The research showed that the proportion of individuals with club partners is higher in a high-population period (35 %) and lower in a low-population period (18 %); the differences, however, are not significant. In both study periods, from 73% (1988-1989) to 80 % (2008-2015) individuals were consistent in following the chosen strategy of forming or not forming club pairs for at least two seasons. The presence of club pairs seems to facilitate the change of mate in the next breeding season, but club mates then become partners relatively seldom.


2021 ◽  
Vol 3 ◽  
pp. ec03045
Author(s):  
Eduardo P. Sousa Neto ◽  
Izabel V. Souza ◽  
Elio C. Guzzo ◽  
José Wagner S. Melo

The red palm mite, Raoiella indica Hirst, 1924 (Tenuipalpidae), has been spreading rapidly and expanding its host range in the Neotropical region. Most of the hosts are palm trees (Arecaceae). In the present work, high population levels of R. indica are reported on “carnauba” [Copernicia prunifera (Miller) H. E. Moore, Arecaceae] in the states of Alagoas and Ceará, northeastern Brazil. This is the first report of R. indica causing damage and injuries on this palm tree native to Brazil in field. Our results allow us to conclude that carnauba is a suitable host for R. indica, with potential risk to its cultivation and exploitation.


Author(s):  
Mohammad Taghi Sheykhi

The two variables of population and development affect each other in an indirect manner in which when population increase happens, development is reduced. The two effectively impact quality of life. It is strongly recommended to control population in order to achieve development. Sociologists are widely responsible to create the balance of population and development. As resources are limited in each country, an organized and planned population is needed towards any development. The phenomenon development being multi-lateral, needs an appropriate population size. It is worth mentioning that population naturally grows, but resources for development do not. Overall, Asia, Africa, and Latin America had very high population growth rate of 2.1% between 1955 and 1975. Fortunately, increase of literacy and education has caused population growth rates to decline in the past two decades in many parts of the developing countries. The only part of the developing world with high population growth rate is Africa in which the population will increase to over 4.2 billion by the year 2100; threatening other parts of the world. Such a situation will widely endanger quality of life.


2021 ◽  
Vol 12 ◽  
Author(s):  
Tobias Otterbring ◽  
Michał Folwarczny ◽  
Lynn K. L. Tan

Population density has been identified as an ecological factor with considerable behavioral implications. The present research aimed to examine whether the mere perception of more (vs. less) populated places can change consumers’ luxury-linked brand attitudes. To this end, we experimentally manipulated consumers’ perceptions of population density using pictorial exposure to high (vs. low) population density cues. The results revealed a significant interaction between manipulated population density and perceived brand luxury on brand attitudes. Specifically, exposure to high rather than low population density cues resulted in more positive (negative) attitudes toward brands deemed to be more (less) luxurious. These findings support our prediction that high population density cues can shift people’s perceptions in consumption contexts linked to luxury. Our work contributes to the growing stream of literature on population density and suggests that this (geo-) demographic factor can exert important downstream effects on consumer behavior.


2021 ◽  
pp. 147078532110509
Author(s):  
Jessica Daikeler ◽  
Henning Silber ◽  
Michael Bošnjak

A major challenge in web-based cross-cultural data collection is varying response rates, which can result in low data quality and non-response bias. Country-specific factors such as the political and demographic, economic, and technological factors as well as the socio-cultural environment may have an effect on the response rates to web surveys. This study evaluates web survey response rates using meta-analytical methods based on 110 experimental studies from seven countries. Three dependent variables, so-called effect sizes, are used: the web response rate, the response rate to the comparison survey mode, and the difference between the two response rates. The meta-analysis indicates that four country-specific factors (political and demographic, economic, technological, and socio-cultural) impact the magnitude of web survey response rates. Specifically, web surveys achieve high response rates in countries with high population growth, high internet coverage, and a high survey participation propensity. On the other hand, web surveys are at a disadvantage in countries with a high population age and high cell phone coverage. This study concludes that web surveys can be a reliable alternative to other survey modes due to their consistent response rates and are expected to be used more frequently in national and international settings.


COMMICAST ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 153-157
Author(s):  
Suci Ledian Khairina ◽  
Arifin Saleh

Indonesia is an equatorial country which has a high population density. Data from the Central Bureau of Statistics in 2010 stated that of the total population of 237.6 million, including teenagers aged 10-24 years as much as 27.6 percent. The number of Indonesian adolescents based on the projection of Indonesia's population from 2010 to 2035 in 2018 will reach around 66.3 million (25.6%) of the total population. Based on this, the government must try to control the very high population growth rate. In this study, the authors used a qualitative descriptive research method. The results of the research are the role of an ambassador for the planning generation in disseminating the BKKBN program to the community, especially to adolescents in North Sumatra in order to prepare family life for adolescents to realize a prosperous family, then the target material that must be conveyed by the ambassadors for the planning generation is adolescent reproductive health, PKBR (Preparation of Family Planning for Youth), Life Skill, GenRe Program, Population, and other materials related to the BKKBN program. to the ambassador to maximize the targets and vision and mission to be achieved. In the aspect of completeness of information, it needs to be evaluated in order to provide the information needed by adolescents so that they still get mutual support to achieve the target of holding a periodic evaluation activity to measure the success of achieving their targets.  


2021 ◽  
Vol 1 (2) ◽  
pp. 104-116
Author(s):  
Nabilla Septiana ◽  
Dinie Ramdhani Kusuma ◽  
Yunita Hapsari

Sexually Transmitted Infections (STIs) are diseases that can be transmitted from one person to another, can be caused by bacteria, viruses, parasites, and fungi. STIs can be transmitted through vaginal, anal, and oral sex. This article aims to identify STIs and their management. The sources used are scientific journals and textbooks. Source searches were conducted on the online portals of journal publications such as the National Center for Biotechnology Information / NCBI (ncbi.nlm.nih.gov) and Google Scholar (scholar.google.com). Transmission of STIs can occur due to interactions between agents (disease-causing factors), hosts (humans as hosts), and the environment (environmental factors). The increase in the incidence of STIs is influenced by several factors, including demographic changes such as very high population growth, increased community movements due to work or tourism, advances in IT-based technology (Technology Information) and socio-economic improvements.


2021 ◽  
Author(s):  
Xingyi Deng ◽  
Dominic Alfonso ◽  
Thuy-Duong Nguyen-Phan ◽  
Douglas Kauffman

Abstract Coinage metals (Au, Cu and Ag) are state-of-the-art electrocatalysts for the CO2 reduction reaction (CO2RR). Size-dependent CO2RR activity of Au and Cu has been studied, and increased H2 evolution reaction (HER) activity is expected for small catalyst particles with high population of undercoordinated corner sites. A similar consensus is still lacking for Ag catalysts because the ligands and stabilizers typically used to control particle synthesis can block specific active sites and mask inherent structure-property trends. This knowledge gap is problematic because increased performance and catalyst utilization are still needed to improve economic viability. We combined density functional theory, microkinetic modeling, and experiment to demonstrate a strong size-dependence for pristine Ag particles in the sub-10 nm range. Small diameter particles with a high population of Ag edge sites were predicted to favor HER, whereas CO2RR selectivity increased towards that of bulk Ag for larger diameter particles as the population of Ag(100) surface sites grew. Experimental results validated these predictions and we identified an optimal particle diameter of 8-10 nm that balanced selectivity and activity. Particles below this diameter suffered from poor selectivity, while larger particles demonstrated bulk-like activity and reduced catalyst utilization. These results demonstrate the size-dependent CO2RR activity of pristine Ag catalysts and will help guide future development efforts.


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