Population Redistribution Research Articles

Impact of charge compensation on optical and thermometric behaviour of titanate phosphors

The structural and optical characterization of the CaTiO3: Er3+/Yb3+ phosphors prepared using conventional solid-state reaction method have been performed through XRD, FESEM, EDAX and diffuse reflectance analysis. The excitation, emission and upconversion (UC) emission studies have been done. The effect of co-doping with Li+/Na+ ions on the UC emission intensity and dynamics involved in the process have been studied. The temperature sensing ability, main cause of concentration quenching, thermal stability, photometric characterization and population redistribution ability have been discussed and the promising applications of the developed phosphors have been explored.

The Continuing Advance and Retreat of Rural Settlement in the Northern Inland of Sweden

In 1960, a range of leading rural geographers started a debate about population development and the “advance and retreat” of human settlement in sparsely populated rural areas, including in the inland north of Sweden. In what came to be known as the “Siljan Symposium,” they identified a number of key themes in relation to migration and human mobility that were thought to determine settlement patterns in the inland north, including: internal migration and urbanisation of populations; the role of simultaneous in- and out-migration in re-shaping settlement patterns; redistribution of rural populations through return migration and international migration; and changing preferences for settlement in different northern “zones” based on the methods for exploiting natural resources for agriculture, forestry, mining and energy production. This paper re-visits the main themes from the 1960 Siljan Symposium and examines Swedish register data to identify how migration patterns and the resulting “advance and retreat” of human settlement have changed across the inland of Västerbotten and Norrbotten. The results suggest that, while general urban-rural and regional-local settlement patterns appear to have been relatively consistent, new forms of migration (including internal, return and international) with different preferences for rural settlement emerging in different localities as a result of both persistent (mining, forestry, energy) and changing (tourism, lifestyle) values of natural resources. We also observe substantial differences in migration and urbanisation rates between Norrbotten and Västerbotten. The paper then discusses how the persistence and discontinuity of experiences over the past decades may provide insights into the potential future patterns of northern settlement.

Миграция населения в контексте экономической безопасности и социальной стабильности

Target: analysis of migration flows in modern Russia and identification of possible threats to economic security and social stability associated with population migration. Methods: a systematic approach, population analysis, comparative analysis, generalization and interpretation of the results. Results and discussion: On the basis of official statistics and expert estimates, an analysis of the situation in the field of population migration in Russia was carried out, the main directions of population redistribution were identified, the need for adjusting the socio-economic policy in regions experiencing significant migration was substantiated. Conclusions. Conclusions are drawn about the possible increase in the negative impact of migration processes on the socio-economic development of the Russian Federation as a whole and individual regions, in particular, which requires their detailed study in order to take measures to optimize migration flows and adjust social and economic policies.

Cellular immunity of rabbits incase of parasite association (Treponema cuniculi and Eimeria sp.)

Despite a huge number of studies, the uniqueness of antiparasitic immunity is so great that there is still insufficient knowledge of the factors contributing to the manifestation of the characteristics of immunity in mixed parasitic diseases of rabbits. Therefore, the question of the influence of the association of pathogens Treponema cuniculi and Eimeria sp. on indicators of cellular immunity of rabbits is relevant. The study was conducted on 59 male rabbits age 3–5 months of the Californian breed, selected by analogy. Animal were separated into two groups: healthy animals (control group) and sick animals (research group). Intensity of invasion was determined by the method of the Mac-Master. It has been established that the level of damage of rabbits by spirochetosis and eimeriosis was, on average, 1155.17 ± 184.87 and 6668.97 ± 284.16 pathogens in 1 g of feces. The count of T- and B-lymphocytes was determined by the method of spontaneous rosette-formation with sheep erythrocytes. Parasitizing the association of pathogens Treponema cuniculi and Eimeria sp. was revealed a high number of leukocytes (1.22 times, P < 0.001), which increased mainly due to lymphocytes, which were 1.45 times higher (P < 0.001), as well as neutrophilic metamyelocytes – 1.48 times (P < 0.05), eosinophils – 1.68 times (P < 0.001) and basophils – 1.57 times (P < 0.001) compared with similar blood parameters of healthy animals. In the blood of sick rabbits, the absolute number of T-lymphocytes (1.56 times, P < 0.001) and B-lymphocytes (3.02 times, P < 0.001) was significantly higher in comparison with a low number of O-lymphocytes (3.46 times, P < 0.001) compared with the control. This indicates the redistribution of lymphocytes to cells that carry T and B lymphocyte receptors on the plasma membrane. The absolute number of T-lymphocytes became high due to T-helpers, which in these animals were higher both in absolute (1.87 times, P < 0.001) and percentage (by 9.18%, P < 0.001) compared to control. Moreover, the percentage of T-suppressors in the blood of rabbits of the experimental group was significantly lower on 5.46% (P < 0.05) compared with the same blood count of healthy animals. Such a redistribution of the T-cell population in the peripheral blood of this group of rabbits led to an increase in the immunoregulatory index by 1.64 times (P < 0.01) than in healthy ones. High IRI and the number of T-active lymphocytes (by 28.23%, P < 0.05) in the blood of rabbits with parasitism of the association of pathogens Treponema cuniculi and Eimeria sp. indicate increased immune system tension.

Increasing impacts from extreme precipitation on population over China with global warming

Precipitation-related extremes are among the most impact-relevant consequences of a warmer climate, particularly for China, a region vulnerable to global warming and with a large population. Understanding the impacts and risks induced by future extreme precipitation changes is critical for mitigation and adaptation planning. Here, extreme precipitation changes under different levels of global warming and their associated impacts on populations in China are investigated using multimodel climate projections from the Coupled Model Intercomparison Project Phase 5 and population projections under Shared Socio-economic Pathways. Heavy precipitation would intensify with warming across China at a rate of 6.52% (5.22%–8.57%) per degree of global warming. The longest dry spell length would increase (decrease) south (north) of ~34°N. The low warming target of the Paris Agreement could substantially reduce the extreme precipitation related impacts compared to higher warming levels. For the area weighted average changes, the intensification in wet extremes could be reduced by 3.22%, 9.42% and 16.70% over China, and the lengthening of dry spells could be reduced by 0.72%, 4.75% and 5.31% in southeastern China, respectively, if global warming is limited to 1.5 °C as compared to 2, 3 and 4 °C. The Southeastern China is the hotspot of enhanced impacts due to the dense population. The impacts on populations induced by extreme precipitation changes are dominated by climate change, while future population redistribution plays a minor role.

Migration flows between levels of the Brazilian urban hierarchy in the period 1980-2010

In the 1980s, an inflexion was observed in the spatial redistribution of the Brazilian population, attributed to the relative economic decentralization initiated in the 1970s, especially regarding industrial activities. These changes in the national space economy led to dramatic changes in the volumes and directions of migration flows. This paper researches the impact of the changing patterns of migration across the Brazilian urban hierarchy over the last three decades to determine if a process of deconcentration, as pointed out by some authors, is, in fact, underway. The flows between different levels of the urban hierarchy were calculated based on census data and represented visually in a series of graphs. If a process of deconcentration is occurring, an increase of flows from urban centres positioned in the higher hierarchical levels to lower ordercentres is expected. This study indicates a process of population concentration in larger cities, but not in the highest level of the urban hierarchy - which suggests an inflexion of historical metropolization tendencies in Brazil. The growing importance of “Regional Capitals”, the second highest level, suggests a process of restructuration and relative decompression of the urban system, although the pace of these changes is slowing down.

The Influence of Environmental Change (Crops and Water) on Population Redistribution in Mexico and Ethiopia

This paper discusses the effects of long-term environmental change (represented by the abundance or scarcity relative to the long-term average level of crop yield/river flow) and short-term environmental shock (represented by the maximum number of consecutive years below the median crop yield/river flow per decade) on population redistribution in Mexico and Ethiopia. Crop production and water resources, which are affected by climate change and influence human survival and activities, were selected as research variables. Two developing countries, namely, Mexico and Ethiopia, were selected as comparison cases. The results showed that short-term environmental shocks had no correlation with population redistribution. Short-term environmental shocks might fail to influence migration decisions or cause only temporary displacements that cannot be detected by demographic statistics. Among the long-term environmental change factors, only crop yield deviation was found to have a significant positive correlation with population redistribution. Based on two different datasets and two different decades, crop yield deviation is positively correlated with population redistribution; the correlation coefficients between crop yield deviation and population redistribution were 0.134 to 0.162 in Mexico and 0.102 to 0.235 in Ethiopia. When urbanization was considered as the control variable, the correlation coefficient between crop yield deviation and population redistribution in Mexico dropped by half, while it was almost the same in Ethiopia. However, Ethiopia’s population redistribution was more clearly influenced by the population itself. Crop yield deviation relative to water flow deviation meant changes in livelihoods. Population redistribution is a possible means of adapting to changes in livelihood. Mexico exhibited high resilience to changes in livelihoods caused by long-term environmental change, especially in its densely populated areas. In contrast, Ethiopia was characterized mainly by high population growth and low population migration. People in some areas of Ethiopia were forced to endure hardship of livelihood deterioration or to stay where they were due to the difficulty of obtaining sufficient resources to afford the cost of migration.

Impact of Internal Migration on Population Redistribution in Europe: Urbanisation, Counterurbanisation or Spatial Equilibrium?

The classical foundations of migration research date from the 1880s with Ravenstein’s “Laws of migration”, which represent the first comparative analyses of internal migration. While his observations remain largely valid, the ensuing century has seen considerable progress in data collection practices and methods of analysis, which in turn has permitted theoretical advances in understanding the role of migration in population redistribution. Coupling the extensive range of migration data now available with these recent theoretical and methodological advances, we endeavour to advance beyond Ravenstein’s understanding by examining the direction of population redistribution and comparing the impact of internal migration on patterns of human settlement in 27 European countries. Results show that the overall redistributive impact of internal migration is low in most European countries but the mechanisms differ across the continent. In Southern and Eastern Europe migration effectiveness is above average but is offset by low migration intensities, whereas in Northern and Western Europe high intensities are absorbed in reciprocal flows resulting in low migration effectiveness. About half the European countries are experiencing a process of concentration toward urbanised regions, particularly in Northern, Central and Eastern Europe, whereas countries in the West and South are undergoing a process of population deconcentration. These results suggest that population deconcentration is now more common than it was in the 1990s when counterurbanisation was limited to Western Europe. The results show that 130 years on, Ravenstein’s law of migration streams and counter-streams remains a central facet of migration dynamics, while underlining the importance of simple yet robust indices for the spatial analysis of migration.* This article belongs to a special issue on “Internal Migration as a Driver of Regional Population Change in Europe: Updating Ravenstein”.

Grabbing from below: a study of land reclamation in Egypt

ABSTRACT The article questions state land commodification and the expansion of frontiers in land reclamation projects in Egypt. It does so by drawing on ethnographic fieldwork in the form of in-depth interviews and archival research on land tenure relations in Wadi Al-Nukra, Upper Egypt. In the article, actors and structure dynamics are situated in the wider political economy framework in order to guide both the data collection and the discussion surrounding the results. The key finding was that agricultural development in the desert created a particular class formation and resulted in specific land concentration. It did not lead to the hegemony of agribusiness nor to the success of desert agriculture in solving agrarian questions or issues relating to food security and population redistribution. The coexistence of different legal frameworks, development policies and discourses concerning allocation of state land, all of these coming from different backgrounds, has led to the concentration of property and to cronyism. It also reveals a deepening social differentiation and class formation. The land reclamation project in desert areas is increasingly moving towards an acceleration of the commodification of state land used for production, accumulation and speculation.

Клітинний імунітет кролів за впливу Treponema Cuniculi

Спірохетоз кролів поширений повсюдно та вражає в окремих кролівничих господарствах від 3-5 до 30 %, а іноді навіть 90 % тварин. Експериментальна частина роботи виконана в ТОВ «Олбест» Дніпропетровської області впродовж 2016–2019 рр. Дослідження проведено на кролях-самцях 3-4 місячного віку, масою тіла 3,5–4,0 кг каліфорнійської породи відібраних за принципом аналогів. З метою визначення рівня ураженості Treponema cuniculi кролів, їх екскременти досліджували за методом Мак-Мастера та поділили на дві групи: здорові тварини (контрольна група) та хворі тварини (дослідна група). Кількість Т- і В-лімфоцитів визначали методом спонтанного розеткоутворення з еритроцитами барана. Спірохетоз у кролів-самців спричинив істотні зміни кількості популяцій Т- і В-лімфоцитів. Встановлено, що у крові кролів, хворих на трепонемоз, відмічалось кількісне збільшення лімфоцитів, в основному за рахунок вірогідного збільшення В-лімфоцитів до 30,57 % (p<0,001). У крові тварин дослідних груп відмічалась кількісне збільшення Т-лімфоцитів на 35,42 % (p<0,01) за рахунок Т-хелперів, які зросли в 1,82 рази, що вказує на активізацію імунної системи організму кролів. Крім цього, у заражених тварин спостерігалась достовірне зменшення О-лімфоцитів до 8,07 % (p<0,001) та відсотка Т-супресорів – до 15,00 % (p<0,01), порівняно зі здоровими. Такий перерозподіл у популяції Т-клітин зумовив зростання імунорегуляторного індексу у кролів дослідної групи в 4 рази, ніж у здорових. У хворих тварин загальна кількість Т-активних лімфоцитів крові була на 23,85 % більшою, ніж у контроля. В цілому отримані результати досліджень показали, що за впливу збудника Treponema cuniculi у крові кролів призвело до збільшення Т- і В-лімфоцитів, Т-хелперів і Т-активних, на фоні зниження О-лімфоцитів і Т-супресорів. Такий перерозподіл популяцій лімфоцитів, свідчать про імунну відповідь за паразитування спірохет.

Impact of Internal Migration on Population Redistribution in Slovenia

Abstract Background: In most countries, data on migration refer only to flows between administratively or statistically defined zones that are changing over time. When different numbers, sizes, and shapes of areas are chosen for analysis of internal migration, different results are generated. This problem is recognised as the Modifiable Areal Unit Problem (MAUP). Objectives: The paper analyses the impact of inter-municipal migration on population redistribution in Slovenia in 2000–2014 by considering the MAUP. Namely, the number of analysed municipalities increased by 19 in the considered period. Methods/Approach: We analysed the MAUP effects and estimated internal migration statistics by producing a large number of aggregations using the IMAGE Studio software. Results: Several statistics that measure the direction and pace of population concentration, as well as the correlation between measures of migration intensity and national development, have been calculated. Conclusions: The results for Slovenia show that the migration efficiency decreases with the development process measured by the human development index.

Bridging the divide: Demographic dynamics and urban–rural polarities during economic expansion and recession in Greece

AbstractDemographic processes such as international migration, internal rural–urban movements, and short‐range residential mobility are increasingly driven by economic cycles. To assess how economic downturns have influenced demographic dynamics across regions in Greece—perhaps the European country most affected by the 2007 recession—the present study investigates spatial patterns of population increase and decline (2002–2017) in 51 prefectures, evaluating the contribution of natural balance (births minus deaths) and migration to total population growth during economic expansion (2002–2009) and recession (2010–2017). Population increased during economic expansion in semicentral regions with medium‐size urban centres, upper economic functions (university and international airport), and road infrastructures. Although natural balance was positive in almost all prefectures, migration contributed the most to population growth during 2002–2009. A generalised population decline was observed during recession, except in coastal areas specialised in tourism, the only regions still attracting migratory flows and maintaining a slightly positive natural balance. The largest urban areas (Athens, Salonika) experienced the highest rate of population decline, thanks to accelerated emigration and a moderately negative natural balance. Population dynamics during economic expansion contributed to increase a traditional density gap between urban and rural areas. Conversely, population dynamics during recession led to a spatial redistribution of population, reducing the gap between urban areas and rural, tourism‐specialised coastal districts. Evidence in our study supports a need for further investigation into the role of economic downturns in future population redistribution processes, specifically “shrinking” regions.

Picosecond time-resolved dynamics of energy transfer between GaN and the various excited states of Eu3+ ions

To elucidate the energy transfer and reexcitation processes in Eu-doped GaN layers that are used in recently developed, highly efficient red light-emitting diodes, a systematic series of photoluminescence and time-resolved photoluminescence (TR-PL) measurements was performed. Critical insights on how ``slow'' Eu processes (\ensuremath{\sim}\textmu{}s) can compete against fast semiconductor processes (\ensuremath{\sim}ps) are revealed using TR-PL with a high temporal resolution, as it is found that the initial energy transfer from GaN to the $\mathrm{E}{\mathrm{u}}^{3+}$ ions takes place rapidly, on a timescale of 100 ps. Below band-gap resonant excitation was used to identify the states into which the energy transfer occurs. For the most efficient Eu defect complexes, this transfer dominantly occurs directly into the $^{5}D_{0}$ state of $\mathrm{E}{\mathrm{u}}^{3+}$. Less efficient complexes also exhibit transfer into the $^{5}D_{2}$ state, the emission of which can be detected using photoluminescence at low temperature, indicating the importance of the excitation pathway on device efficiency. Under high excitation intensity, reexcitation can also occur, leading to a redistribution of population into the $^{5}D_{2}$, $^{5}D_{1}$, or $^{5}D_{0}$ states.

Evolution Characteristics of Spatial Concentration Patterns of Interprovincial Population Migration in China from 1985 to 2015

People migrate between places constantly, promoting population redistribution and socioeconomic element flows. Since China’s interprovincial population migration flows are highly concentrated in particular places and there are comparatively few studies using a spatial concentration perspective in this field, there is room for a spatial analysis. The Gini Index (GI) is commonly used in analysing the concentration of topological data, and it works well with migration flow data. Also, GI is scale-invariant due to its normalized nature, and hence it is readily interpretable. However, due to missing data, the traditional GI specification is often an underestimate. Thus, the authors propose the GIc for better standardisation, and demonstrate its utility in the characterization of interprovincial migration flows in China from 1985 to 2015, quantifying the spatial concentration of migration. The results indicate that (a) the GIc measures the concentration degree of population migration better; (b) collectively, the concentration is consistently high, and it shows a trend in an inverse U-shape over six periods, and there are strong linkages between regions with high origin GIcs and regions with high destination GIcs; (c) since 1995, the concentration at migration origins is high in middle China and some western regions; migration destinations with high concentration are the Yangtze River Delta and the Pearl River Delta, which show a smooth temporal change; (d) origins with high concentration are often connected to destinations with high concentration by strong migration flows that move large populations.

Internal migration in the countries of Asia: levels, ages and spatial impacts

ABSTRACTInternal migration, the movement of people between localities and regions within a country, has resulted in a significant redistribution of national populations. Past cross-national studies have been impeded by a lack of data and comparable metrics upon which to base comparisons. This paper examines internal migration in 30 Asian countries utilising a global dataset and a novel suite of measures devised in the IMAGE project. Three aspects of internal migration are explored: overall intensity, age patterns, and spatial impacts. Comparisons reveal that internal migration intensities, while on average lower than in other regions, are highly variable across countries. Migration peaks at earlier ages and is concentrated into a narrower age band than in other parts of the world. Analysis of spatial impacts highlights the contribution of migration to urbanisation, but a comparison of current trends against lifetime migration data also reveals the impact of historical events and government policies on national migration systems. Wide variation in key dimensions of migration among Asian countries reflects a diversity in national circumstances. The way forward lies in further in-depth country studies building on the common analytic framework articulated in this study.

A binding cooperativity switch driven by synergistic structural swelling of an osmo-regulatory protein pair

Uropathogenic E. coli experience a wide range of osmolarity conditions before and after successful infection. Stress-responsive regulatory proteins in bacteria, particularly proteins of the Hha family and H-NS, a transcription repressor, sense such osmolarity changes and regulate transcription through unknown mechanisms. Here we use an array of experimental probes complemented by molecular simulations to show that Cnu, a member of the Hha protein family, acts as an exquisite molecular sensor of solvent ionic strength. The osmosensory behavior of Cnu involves a fine-tuned modulation of disorder in the fourth helix and the three-dimensional structure in a graded manner. Order-disorder transitions in H-NS act synergistically with molecular swelling of Cnu contributing to a salt-driven switch in binding cooperativity. Thus, sensitivity to ambient conditions can be imprinted at the molecular level by tuning not just the degree of order in the protein conformational ensemble but also through population redistributions of higher-order molecular complexes.

CIDADES NA AGRICULTURA CIENTÍFICA E GLOBALIZADA: TRANSFORMAÇÕES NA DINÂMICA DA POPULAÇÃO E NA ESTRUTURA DO EMPREGO

O objetivo desse trabalho é analisar os processos de redistribuição da população e as mudanças na estrutura do emprego associados à globalização do agronegócio no Estado de São Paulo. Como áreas privilegiadas de transformação social, espaços da globalização cujos vínculos transnacionais mais fortes passam pela produção de commodities, são apresentados os arranjos urbanos-rurais regionais. Nesse estudo, o enfoque recai nos arranjos construídos a partir dos circuitos espaciais produtivos dos setores sucroenergético, citrícola e de frigoríficos de carne bovina. Na condição de espacialidades híbridas, onde tendências históricas coexistem com novos processos, os arranjos urbanos-rurais regionais abrangem múltiplos espaços da migração que expressam toda a desigualdade e segmentação que marca a agricultura científica e globalizada e seu dinâmica de urbanização corporativa.

Shifts in interregional proportions in population settlement over the territory of Russia in 2002-2017

Abstract The article deals with the trends of population size changes in the regions of the Russian Federation between 2002 and 2017 on the basis of data of all-Russian population censuses and current statistics. Components of population growth (natural and migratory movement of the population) are analyzed. In order to take into account the current situation of population size changes in the regions, which are largely of a “turning point” nature and partly inconsistent with the medium-term dynamics since the 2002 Census, the analysis is focused on the period from 2014 to 2017. The paper presents estimates of population size shifts at regional and macro-regional levels, identifies general and local growth centers and depopulation zones. Conclusions are drawn about general shifts in the proportions of population settlement over the territory of Russia and in certain macro-regions (federal districts). General conclusions about the trends of population redistribution across the territory of the country are given in the final part of the study.

Nonlinear spectroscopy of three-level cascade systems in the act of saturable and reverse saturable absorption

In the process of nonlinear absorption study using ultra-short laser pulses, it is imperative to know the population dynamics of excited molecules/atoms as a function of time. Using rate equation approach, we have numerically demonstrated the time-dependent population dynamics of three-level cascade systems under single photon resonant excitation by 125 fs single shot laser pulse with central wavelength at 532 nm. We present the effect of life-times, absorption cross-sections and photon flux on population redistribution among the energy levels by considering the saturable absorption (SA) and reverse saturable absorption process (RSA) in the wide range of spectroscopic parameters such as life-times and absorption cross-sections. In cascade energy level systems, ultra-short laser pulses have to be used to investigate higher energy levels absorption cross-section and life-times. Our results can be extended to higher energy levels of cascade systems by incorporating them into the rate equation models.

Population Mapping with Multisensor Remote Sensing Images and Point-Of-Interest Data

Fine-resolution population distribution mapping is necessary for many purposes, which cannot be met by aggregated census data due to privacy. Many approaches utilize ancillary data that are related to population density, such as nighttime light imagery and land use, to redistribute the population from census to finer-scale units. However, most of the ancillary data used in the previous studies of population modeling are environmental data, which can only provide a limited capacity to aid population redistribution. Social sensing data with geographic information, such as point-of-interest (POI), are emerging as a new type of ancillary data for urban studies. This study, as a nascent attempt, combined POI and multisensor remote sensing data into new ancillary data to aid population redistribution from census to grid cells at a resolution of 250 m in Zhejiang, China. The accuracy of the results was assessed by comparing them with WorldPop. Results showed that our approach redistributed the population with fewer errors than WorldPop, especially at the extremes of population density. The approach developed in this study—incorporating POI with multisensor remotely sensed data in redistributing the population onto finer-scale spatial units—possessed considerable potential in the era of big data, where a substantial volume of social sensing data is increasingly being collected and becoming available.