Availability Ratio Research Articles

Love is Elsewhere: Internal Migration and Marriage Prospects in China

Migration and marriage are major life events that might interact and be jointly decided. Places with good labor market opportunities may or may not provide good marriage options. In this paper, I quantify gains and losses in marriage prospects for unmarried migrants and natives during the population redistribution driven by internal migration. I also examine how the experiences differ by individual characteristics and regional factors. The analysis measures marriage prospects using the availability ratio (AR) with adaptive assortative matching norms for every unmarried individual from sample data of the 2010 China population census. The AR quantifies the intensity of competition for suitable partners in the local marriage market. I compare (1) migrants’ current AR with an alternative AR if the migrant returned to the hometown and (2) natives’ AR with a hypothetical AR if all migrants returned to their hometown. The first comparison shows that among migrants moving for labor market opportunities, most women have higher ARs (better marriage prospects) in the place of residence than in their hometown, especially those of rural origin. In contrast, migrant men’s ARs mostly decrease after migration except for the best educated. The second comparison reveals small negative externalities of internal migration on ARs for native women but positive impacts for some native men. The results suggest a conflict between labor market opportunities that dominate internal migration decisions and marriage market opportunities in China. This study demonstrates a method to quantify and compare marriage prospects and extends the literature on how migration and marriage interact.

Investigation of Ecological Risk (ER) and Available Ratio (AR) of some heavy metals in drill cutting of Ahvaz Oil Field in 2019

Investigation of Ecological Risk (ER) and Available Ratio (AR) of some heavy metals in drill cutting of Ahvaz Oil Field in 2019

Soil accumulation and chemical fractions of Cu in a large and long-term coastal apple orchard, North China.

Coastal orchards, with greater humidity and precipitation, are favorable for fruit production, as well as mildew fungi development, thus becoming hot spots of Cu concentrations in soils due to the use of copper-based fungicides. However, little is known on the variation tendencies of Cu availability and mobility from these soils. This study aims to investigate the accumulation, spatial-temporal distribution, and chemical fractions of soil Cu in one of the largest coastal apple-producing area with over 40-year intensive cultivation in China. A total of 104 orchard and 31 farmland topsoil samples were collected from Jiaodong Peninsula, Shandong Province. The total Cu concentration (T-Cu) and major element components (MnO, TiO2, SiO2, Fe2O3, and Al2O3) in the soil were determined by X-ray fluorescence spectroscopy. Available Cu concentration (A-Cu) was extracted with HCl or DTPA. Chemical fractionations of Cu were determined via sequential extraction method. The variation tendencies of T-Cu, A-Cu, Cu available ratio (AR), and chemical fractions with planting duration in the orchards were explored while a cokriging method was selected to predict their spatial distributions. Moreover, Pearson's correlation and multiple linear stepwise regressions were constructed to distinguish the vital factors in controlling Cu availability and mobility from these soils. The results showed that long-term application of Cu-containing fungicides had increased Cu concentrations in orchard soils (85.77 mg kg-1) 3.5 times higher than the background value (24.0 mg kg-1) of local agricultural soils, in which 23.8% existed in the available form. Cu in the weak acid-soluble fraction (F1, 5.0 ± 3.5 %), reducible fraction (F2, 24.7 ± 6.6%), and oxidizable fraction (F3, 18.5 ± 7.8%) in orchard soils increased significantly with increasing planting durations whereas the residual fraction (F4, 51.7 ± 15.4%) exhibited a reverse trend. Total content, available content, and chemical fractions of Cu showed strong spatial heterogeneity. The availability and mobility of Cu in orchard soils were mainly controlled by total Cu content, pH, and soil organic carbon. Coastal orchards under warm and humid climate condition in China exhibited higher Cu input, along with acidification and rapid organic carbon turnover in the soils, eventually leading to large accumulation and high mobility of Cu in the soils.

Partner market opportunities and union formation over the life course—A comparison of different measures

AbstractEven in the online dating era, individuals will seek intimate partners who live physically nearby. This paper considers the validity of different partner market measures in German NUTS‐3 regions; the often used sex ratio is contrasted with different versions of the availability ratio (AR) and versions of the partner market density (PMD). The paper discusses (a) how conceptional aspects of the partner market are reflected in the various indicators. Using aggregated population data provided by German statistical offices, (b) the partner market in Germany is described as measured by the different partner market indicators. Linking them to micro‐level data from the German Socio‐economic Panel, the paper (c) compares the effects of the various partner market measures on union formation. A simple sex ratio does not show variance over the life course or between cohorts, nor does it determine the rate of couple formation. The AR and PMD reveal more plausible distributions by age and cohort and higher criterion validity, especially when accounting for availableness according to marital status. With regard to men, the AR demonstrates the strongest impact on union formation; with regard to women, PMD seems more important.

Signs for secondary buildup of heavy metals in soils at the periphery of Athens International Airport, Greece.

Emissions from civil airports are similar to those observed in industrial and urban areas. While air pollution and noise levels are regularly monitored and assessed, information on the status of heavy metals in soils close to airport facilities is limited. In this study, we monitored and assessed heavy metal distribution in soils close to Athens International Airport (AIA) in Attica, Greece. Following a grid sampling scenario, topsoil samples were collected from 86 sites at the periphery of AIA and total and available forms of Cu, Zn, Fe, Mn, Ni, Cr, Pb, and Ba concentrations were determined in aqua regia and DTPA soil extracts, respectively. Median concentration values for both metal forms are not considered as particularly high. However, 90th percentile concentration values for some metals are high, indicating soil enrichment. Evaluation of enrichment factor (EF) and availability ratio (AR) values and EFs spatial distribution have led to consistent conclusions of secondary and ongoing metal accumulation in the soils of the studied area. Tessier sequential extraction procedure was applied to 10% of the soil samples and the results showed high potential availability of Pb, Mn, Cu, and Ni, further supporting the continuous metal accumulation in the studied soils.

Assessment of vertical contamination of Cd, Pb and Zn in soils around a former ore smelter in Wallonia, Belgium

Concentrations of trace elements (Cd, Co, Cr, Cu, Ni, Pb and Zn) and major elements (Ca, Mg, K, Fe, Al and Mn) as well as pHKCl and total organic carbon (TOC) were measured on 22 profiles located in a 3 km radius of a former ore treatment plant in Wallonia (Belgium). The enrichment factor (EF), vertical impoverishment factor (VIF) and availability ratio (AR) were used as diagnostic tools of contamination and migration of Cd, Pb and Zn in profiles. The data revealed that the soil profiles are significantly contaminated. The ranges of EFs for Cd (17–3570), Pb (1–2883) and Zn (2–309) are very broad with the higher EF in the topsoil of the profiles. VIFs of subhorizons are rarely above 1. In the few cases with VIF > 1, the main factor explaining is the soil type (in particular, Colluvic Regosols, Luvisols and Cambisols with shale load). Cd, Pb and Zn ARs are strongly correlated with TOC and to a lesser extent with pHKCl; Pb and Zn ARs are influenced by soil type, while land use only has an effect on Zn AR. The Cd availability is independent of these two factors. The contents of trace elements measured in soil profiles are very high, especially in topsoil. At present, the Cd, Pb and Zn vertical distribution shows a low migration from topsoil to deeper levels. However, we must not discount the hazard of a future potential transfer.

Total and available heavy metal concentrations in soils of the Thriassio plain (Greece) and assessment of soil pollution indexes

The Thriassio plain is located 25km west of Athens city, the capital of Greece. Two major towns (Elefsina and Aspropyrgos), heavy industry plants, medium to large-scale manufacturing, logistics plants, and agriculture comprise the main land uses of the studied area. The aim of the present study was to measure the total and available concentrations of Cr, Zn, Ni, Pb, Co, Mn, Ba, Cu, and Fe in the top soils of the plain, and to asses soil contamination by these metals by using the geoaccumulation index (I geo), the enrichment factor (EF), and the availability ratio (AR) as soil pollution indexes. Soil samples were collected from 90 sampling sites, and aqua regia and DTPA extractions were carried out to determine total and available metal forms, respectively. Median total Cr, Zn, Ni, Pb, Co, Mn, Ba, Cu, and Fe concentrations were 78, 155, 81, 112, 24, 321, 834, 38, and 16 × 10(3)mg kg(-1), respectively. The available fractions showed much lower values with medians of 0.4, 5.6, 1.7, 6.9, 0.8, 5.7, 19.8, 2.1, and 2.9mg kg(-1). Though median total metal concentrations are not considered as particularly high, the I geo and the EF values indicate moderate to heavy soil enrichment. For certain metals such as Cr, Ni, Cu, and Ba, the different distribution patterns between the EFs and the ARs suggest different origin of the total and the available metal forms. The evaluation of the EF and AR data sets for the soils of the two towns further supports the argument that the EFs can well demonstrate the long-term history of soil pollution and that the ARs can adequately portray the recent history of soil pollution.