Promise, premise, and reality: the case of voluntary environmental non-migration despite climate risks in coastal Bangladesh

Despite confronting severe climatic risks, many people prefer to remain in climate hazard-prone areas rather than migrate. Environmental non-migration behavior, however, has gained relatively little research attention in the field of migration processes. This study aims to unveil the determinants motivating voluntary environmental non-migration decisions in coastal Bangladesh, an area highly exposed to flooding and other climate-related hazards (e.g., soil salinization). Applying a systematic random sampling, we selected 556 household respondents for a questionnaire survey from 14 villages of two coastal districts: Khulna and Satkhira. Applying a mixed method (i.e., both quantitative and qualitative) approach, major empirical results of this study suggest that even though all respondents lived in a similar situation in terms of climatic hazard and exposure, 88% of the respondents reported themselves as voluntary non-migrants. Furthermore, these non-migrants enjoyed higher socioeconomic and sociopsychological advantages and availed more local support from different government and non-government organizations than involuntary non-migrants. Again, mutual assistance, connection with social groups, natural resource access, sense of secured livelihood, stable societal atmosphere, and participation in decision-making in society appeared to build their higher degree of social capital $$({\chi }^{2}\left(4\right)=57.80;p<0.000)$$ ( χ 2 4 = 57.80 ; p < 0.000 ) compared to involuntary non-migrants. All these features lead to a favorable environment that ultimately drove the respondents to become voluntary non-migrants.

The Influence of Political Capital on Peasants’ Migration Behavior and Its Implications

This study examined the influence of political capital on the migration behavior of peasant households in China’s equitable urbanization. While existing research has proven that political capital can increase the wages of migrant workers, leading to a higher possibility of their rural-to-urban migration, the direct impact of political capital on migration behavior has not received sufficient attention. As China is one of the largest emerging economies, the impact of political capital on the economy and political transformation is typical. This paper reports a survey of 1120 farmer households from Xinxiang, a traditional agricultural area in central China. Using a binary logit model to test whether peasant households will migrate and a multinomial logit model to test where they will migrate to, this study examined whether political capital had a significant influence on the migration behavior of peasant households. The results suggest that the peasant households with political capital have a higher possibility of moving to urban areas, even though there is a better habitational option, namely, a new village in the local rural area. This suggests that reducing the difference in the political capital of migrants through policy propaganda and other methods is an efficient and effective way to achieve and improve equitable access to urbanization.

Element Distribution and Migration Behavior in the Copper Slag Reduction and Separation Process

Copper slag is a solid pollutant with high recyclability. Reduction and separation are regarded as effective disposal methods. However, during the melting process, the separation and migration behavior of elements in the copper slag is complicated. Thus, the formation of pollutants cannot be controlled merely by optimizing the operation parameters. The elemental distribution and migration behavior are discussed in this work. In reduction experiments, the copper slag smelting liquid was divided into three layers: a reduction slag layer, a reactive boundary layer, and an iron ingot layer. Reduction slag and ingot iron were on the top and bottom of the liquid, respectively. Residual carbon oozed at the interface. C can react with reducible “O” atoms, which exist in 2FeO·SiO2, Fe3O4, and CuO. Meanwhile, CO was generated and overflowed from the liquid layer. After reduction by C or CO, metallic iron and copper were produced and migrated to the iron ingot layer. In the liquid, S gradually diffused into the upper layer. Some of the ZnO and CuS spilled from the liquid into the flume. After reduction, CaO·SiO2 was generated and moved to the upper layer.

Effect of Hydroxyapatite Microspheres, Amoxicillin–Hydroxyapatite and Collagen–Hydroxyapatite Composites on Human Dental Pulp-Derived Mesenchymal Stem Cells

In this study, the preparation and characterization of three hydroxyapatite-based bioactive scaffolds, including hydroxyapatite microspheres (HAps), amoxicillin–hydroxyapatite composite (Amx–HAp), and collagen–hydroxyapatite composite (Col–HAp) were performed. In addition, their behavior in human dental pulp mesenchymal stem cell (hDPSC) culture was investigated. HAps were synthesized through the following methods: microwave hydrothermal, hydrothermal reactor, and precipitation, respectively. hDPSCs were obtained from samples of third molars and characterized by immunophenotypic analysis. Cells were cultured on scaffolds with osteogenic differentiation medium and maintained for 21 days. Cytotoxicity analysis and migration assay of hDPSCs were evaluated. After 21 days of induction, no differences in genes expression were observed. hDPSCs highly expressed the collagen IA and the osteonectin at the mRNA. The cytotoxicity assay using hDPSCs demonstrated that the Col–HAp group presented non-viable cells statistically lower than the control group (p = 0.03). In the migration assay, after 24 h HAps revealed the same migration behavior for hDPSCs observed compared to the positive control. Col–HAp also provided a statistically significant higher migration of hDPSCs than HAps (p = 0.02). Migration results after 48 h for HAps was intermediate from those achieved by the control groups. There was no statistical difference between the positive control and Col–HAp. Specifically, this study demonstrated that hydroxyapatite-based bioactive scaffolds, especially Col-Hap, enhanced the dynamic parameters of cell viability and cell migration capacities for hDPSCs, resulting in suitable adhesion, proliferation, and differentiation of this osteogenic lineage. These data presented are of high clinical importance and hold promise for application in therapeutic areas, because Col–HAp can be used in ridge preservation, minor bone augmentation, and periodontal regeneration. The development of novel hydroxyapatite-based bioactive scaffolds with clinical safety for bone formation from hDPSCs is an important yet challenging task both in biomaterials and cell biology.