Degree Of Spatial Separation Research Articles

Analysis of the Housing–Jobs Separation Characteristics of Different Village Types in the Mountainous and Hilly Region of Southwest China

The economic and social transition toward modernization is characterized by a massive outflow of rural labor, which raises problems such as rural job–housing separation and rural decline. Few studies have used rural labor employment microdata to quantitatively analyze the degree of separation between housing and jobs in different types of villages, especially in ecologically fragile mountainous and hilly regions. This article is based on a 2021 survey of 6181 rural households in 158 villages of Chongqing, a mountainous and hilly region of China, and divides villages into city edge, suburban, and outer suburban villages. In this study, the separation degree of housing–jobs (SDHJ) measurement model was created in order to explore the degree of separation between rural jobs and housing in terms of space–time dimension separation in these areas, and the different job–housing separation characteristics under different village types were distinguished. The results show the following. (1) The county’s rural SDHJ has a clear regional differentiation law, and the degrees of separation between housing and jobs in all counties are in the following order: main urban area < northeast of Chongqing < southeast of Chongqing. The degree of separation between housing and jobs presents a spatial pattern of “medium–low perimeter high, local prominence” according to both the degree of temporal separation and the degree of spatial separation. (2) The degrees of separation between housing and jobs in various village types are in the following order: urban fringe villages < suburban villages < outer suburban villages. The distance effect was verified. The SDHJ is typically low in urban fringe villages and moderate in suburban villages, with distinct geographical disparities in labor distribution. The SDHJ is typically higher in the outer suburban villages, where laborers choose long-term long-distance employment. (3) This study proposes some countermeasures that could reduce the SDHJ for different types of villages. The findings have important policy implications for China’s mountainous rural development and serve as a model for other developing countries.

When Spatial Dimension Matters: Comparing Personal Network Characteristics in Different Segregated Areas

Living in segregated areas with concentrated neighbourhood poverty negatively affects the quality of life, including the availability of local jobs, access to services, and supportive social relationships. However, even with similar neighbourhood poverty levels, the degree and structure of spatial separation vary markedly between such areas. We expected that the level of spatial segregation aggravates the social exclusion of its inhabitants by negatively affecting their social capital. To test this hypothesis, we identified three low‐income neighbourhoods with high poverty rates (78%) in a medium‐sized town in Hungary, with different levels of integration in the city (based on characteristics such as the degree of spatial separation, infrastructure, and availability of services). The three neighbourhoods were located in two areas of differing degrees of integration in the fabric of the city: fully integrated, semi‐integrated (integrated into the surrounding residential area but isolated from the city), and non‐integrated. 69% of the 394 households in these areas were represented in our sample (one respondent per household). We interviewed respondents regarding the size and composition of their personal networks. Our results, which also distinguished between Roma and non‐Roma inhabitants, showed that those living in the spatially more integrated area not only have the largest and most diverse networks but seem to have a strong, “bonding‐based” cohesive community network as well. Even the non‐Roma who live there have ethnically heterogeneous—in other words—Roma network members. The disintegrated area, on the other hand, is characterised by both spatial and social isolation.

Accounting and Characteristics Analysis of CO2 Emissions in Chinese Cities

Accurate estimation of CO2 emissions is a prerequisite for scientific low-carbon emission policymaking. Based on 20 types of energy consumption data at the prefecture level in China, this paper re-estimates the CO2 emissions of 198 prefecture-level cities in 2016 by using the method of carbon emission coefficient. The spatial pattern and scale characteristics are analyzed, and the conclusions are as follows: (1) Overall, China’s urban CO2 emissions show a certain degree of spatial separation in terms of the total amount, per capita emissions, and emission intensity. Cities with the highest CO2 emissions in China are mainly concentrated in North China, East China and Chongqing, while cities with the highest per capita CO2 emissions and emission intensity are mainly concentrated in Northwest and North China. (2) Different types of cities have different CO2 emission characteristics. Resource-based cities have a higher total amount and emission intensity; tourism and underdeveloped cities both have lower values; while super-large-sized cities and many very-large-sized cities have higher CO2 emissions, but their emission intensities are usually lower; and no obvious rules are found in other cities. (3) Spatial analysis shows that cities with higher CO2 emissions are clustered. The Beijing–Tianjin–Hebei region, the Yangtze River Delta region, Shandong Province, and Shanxi–Henan–Anhui resource-producing areas are the agglomeration areas of high-emission cities. (4) Scale analysis shows that the characteristics of CO2 emissions at different scales are different. Provincial-level research can help to identify the environmental impact and total effect of carbon emissions, while urban-scale research is helpful to explore the diversity and phases of cities. Finally, based on the main conclusions of this study, the corresponding urban low-carbon policy implications are drawn.

Estimation of transport accessibility of the Capital Economic Region

The methodology for estimation of potential transport accessibility of the region, which requires merely open data, was identified. The choice of the Capital Economic Region as the region for estimation of transport accessibility was validated. The study solved the problem of adapting the foreign approach to calculation of potential transport accessibility of the Capital Economic Region. The highlight of the given research is the application of Euclidean distance between the cities (nodes) and the total of activity types available in the destination node as the initial data for estimating transport accessibility. The proposed methodology of potential road transport accessibility estimation of the region enables revealing of the potential deficiencies in the transport infrastructure of the region. This is provided by the special feature of the methodology which is based on the suggested equation for calculation of transport accessibility and the scale developed in the paper. The scale contains seven levels of potential transport accessibility of the Capital Economic Region and it enables quantitative evaluation of the transport accessibility values for the given city (node) in relation to the set of other cities (nodes). Thus, the degree of spatial separation of the cities related to the regional center can be defined. The given methodology can be applied for other regions of Ukraine to evaluate current efficiency of the road transportation network. It is recommended to devise a new scale for evaluating potential transport accessibility while applying the proposed methodology to another region. Other possible applications of the methodology include urban planning, transport planning, creating and / or developing regional transport systems.

The avoidance of self-interference in the Tuscan endemic spring geophyte Crocus etruscus Parl. (Iridaceae)

Spatial separation between sexes within hermaphrodite flowers (herkogamy) is widespread among angiosperms and is traditionally viewed as an adaptation that reduces the likelihood of self-pollination. While different degrees of herkogamy have been reported for Crocus, the relationship between sexual organ positions and reproductive fitness has not been explored yet, and studies of the breeding system within natural populations remain scarce within the genus. We analyzed the effects of different breeding systems (spontaneous self-pollination, facilitated self-pollination and cross-pollination) and of herkogamy degree on female reproductive success of the Tuscan endemic Crocus etruscus. Results showed that C. etruscus is monomorphic for style length and self-incompatible (SCI = 0.29). We also detected a significant negative effect of herkogamy on seed set of open-pollinated flowers. Thus, we conclude that the species avoids self-fertilization by self-incompatibility, but interestingly shows also a certain degree of spatial separation of male and female reproductive structures within the same flower. This floral trait could be useful to avoid self-interference thus reducing ovule discounting and pollen loss on its own stigma.

Multimodal spatial discrimination in the face of uncertainty

The current study expands upon previous research that has demonstrated perceptual and attentional superiority of action video game (AVG) players. Here, the effects of AVG expertise are further examined by measuring visual-spatial and auditory-spatial discrimination performance under varying degrees of spatial separation and ambiguity. AVG players (experts) and novices completed a visual and an auditory spatial discrimination task in which error rates and reaction times (RTs) were recorded. Data analysis of 58 participants (29 experts, 29 novices) revealed that, compared to novices, experts were better able to discriminate spatial location in both the auditory and visual modalities. Additionally, in the auditory condition, experts were able to overcome moderate spatial ambiguity, while novices could not. These results indicate that action video game expertise should be considered when selecting operators for tasks requiring spatial precision in multiple modalities.

Influences of Plant Toxins and Their Spatial Distribution on Foraging by the Common Brushtail Possum, a Generalist Mammalian Herbivore

Generalist herbivores forage on a variety of plant species, allowing them to gain nutrients while limiting ingestion of harmful toxins. As the capacity to mix diets appears important for maximizing intake, the spatial scale in heterogeneity of food resources should influence the foraging behavior of herbivores. Our aim was to identify how the feeding strategy of a generalist mammalian herbivore, the common brushtail possum, responds to foods within a spatially defined environment. We evaluated foraging responses against increasing spatial separation between pairs of artificial diets that differed in flavor and toxin profile, to determine how distance and diet affect intake and behavior. Foraging responses were influenced by the type of diet or the degree of spatial separation between foods but not by their interaction. Diet influenced intake, time spent feeding, and feeding rate, but had no effect on nightly foraging interval, number of feeding bouts, or bout length. The number of switches between paired food resources and foraging efficiency (intake per unit distance, which accounts for the energetic costs of travelling), were influenced only by distance. Titrating foraging against a range of distances demonstrated how quickly foraging efficiency can decline in response to the spatial separation of food resources, highlighting the importance of spatial heterogeneity of plants within the home range of an herbivore.

On the temperature and tension dependence of the outer hair cell lateral membrane conductance G metL and its relation to prestin

Recently, we identified an outer hair cell (OHC) lateral membrane conductance, GmetL, that colocalizes with prestin and passes Cl-, thereby influencing prestin's (SLC26A5) electromechanical activity. In this study, we report on a comparison of the temperature and tension dependence of GmetL and prestin. Though we find significant temperature and tension dependence of each, substantial differences exist which indicate their independent identity. The following data support this conclusion: (1) The voltage dependence of GmetL does not follow that of prestin's nonlinear capacitance (NLC) function when the latter is shifted by either temperature or membrane tension; (2) Unlike native OHCs whose NLC can be modulated by influx of extracellular Cl-, prestin-transfected Chinese hamster ovary (CHO) cells do not show this phenomenon; (3) Stretch-sensitive, single channel currents are not evidenced after prestin transfection in CHO cells; and (4) There is no correlation between prestin expression level (gauged via NLC) and transmembrane current through GmetL. Thus, GmetL must result from the activity of another molecular species within the lateral membrane of the OHC. A clue to its identity is the conductance's nonlinear temperature dependence in contrast to prestin and other OHC conductances' linear dependence. Whereas K+ conductances in OHCs present a uniform Q10 close to 1.2, GmetL shows a bimodal Q10, with a Q10 of 1.5 below 34 degrees C and a Q10 of greater than 4 and above. The dissociation of SLC26A5 (prestin) and GmetL theoretically provides for a modifiable anionic feedback to prestin via the degree of spatial separation between these interacting partners within the OHC lateral membrane.

An experimental evaluation of self-interference in Narcissus assoanus: functional and evolutionary implications

Floral traits that reduce self-pollination in hermaphroditic plants have usually been interpreted as mechanisms that limit the genetic consequences of self-fertilization. However, the avoidance of sexual conflict between female and male function (self-interference) may also represent an important selection pressure for the evolution of floral traits, particularly in self-incompatible species. Here, we use experimental manipulations to investigate self-interference in Narcissus assoanus, a self-incompatible species with a stigma-height dimorphism in which the degree of spatial separation between sex organs (herkogamy) differs strikingly between the long- and short-styled morphs (hereafter L- and S-morphs). We predicted that weak herkogamy in the L-morph would cause greater self-pollination and hence self-interference. Experimental self-pollination reduced seed set when it occurred prior to, or simultaneously with, cross-pollination in the L-morph, but only if it occurred prior to cross-pollination in the S-morph. In the field, autonomous self-pollination was greater in the L-morph than the S-morph, but we found no evidence that self-interference reduced maternal or paternal fitness in either morph. One-day-old flowers of the L-morph have reduced stigma receptivity and hence exhibit protandry, whereas stigma receptivity and anther dehiscence are concurrent in the S-morph. This suggests that the two style morphs have alternative strategies for reducing self-interference: dichogamy in the L-morph and herkogamy in the S-morph. These results provide insight into the mechanisms that reduce sexual conflict in hermaphrodite plants and are of significance for understanding the evolution and maintenance of sexual polymorphisms.

The effect of charge-carrier drift in the built-in quasi-electric field on the emission spectrum for graded-gap semiconductors

The effect of bulk (τ) and radiative (τr) charge-carrier lifetimes on the degree of spatial separation of the regions of the carriers’ generation and radiative recombination in graded-gap semiconductors with the drift transport mechanism in the built-in quasi-electric field of the crystal was investigated experimentally and theoretically. It was found that the degree of spatial separation increases with increasing τ and/or τr. The effect of spatial separation of the regions of radiative recombination, which correspond to transport mechanisms with various τr, was observed. The data obtained are related to the coordinate dependence of recombination probability for graded-gap semiconductors.

Rules of Intersensory Integration in Spatial Scene Analysis and Speechreading

Audiovisual interactions observed in the ventriloquism and McGurk illusions were compared, using the same materials. The ventriloquism effect was estimated through a discordance detection task and the McGurk illusion through an identification task. The stimuli were visually displayed on a screen located in front of the participants’ head and acoustically delivered through one of nine hidden loudspeakers located from straight ahead (0°) to 80° (20° steps) left and right. The speaker’s face was either upright or inverted. The ventriloquism effect was affected by the degree of spatial separation, but unaffected by upright vs. inverted presentation of the face, or by the congruency of the stimuli. The McGurk illusion was of the same size whatever the loudspeaker location but was reduced by face inversion. The differences in the spatial and cognitive rules that govern both interactions are discussed in terms of specific functionality of the underlying mechanisms.

Laws governing the creation of electronic color centers in LiF crystals acted on by pulsed irradiation

The processes of creating and transforming electronic color centers in an LiF crystal irradiated with a nanosecond electron pulse are investigated using pulse spectrometry with nanosecond resolution for times in the range 10−8 to 105 sec. It is shown that the thermally activated mechanism of forming Frenkel pairs in the 12–200 K range consists of successively creating exciton states, as the temperature rises, having different degrees of spatial separation of the electron and hole components. It is concluded that the structure of self-trapped excitons evolves as a function of temperature and time, and that this evolution commences for any alkali halide crystal with the creation of self-trapped excitons ofD 2h point symmetry at 4 K. It is established that the interaction of electronic excitations with electronic color centers changes the properties of both the electronic excitations themselves and the color centers. In a crystal containing neutral electronic centers there is a fall in the yield of self-trapped excitons and Frenkel pairs and an increase in the contribution of the radiative channel for loss of the irradiation energy by the color centers. A mechanism is proposed for exciting luminescence of electronic color centers. It is established that short-lived irradiation-induced states exist, in particular a change in the spin state or in just the energy state of a center in the irradiation field, and that the appearance of these states changes the efficiency and directivity of the charge evolution of the electronic color centers.

Perception of visual apparent movement and topographic analysis of related evoked potentials.

Most of the studies in long-range apparent movement have been concerned with the psychophysical properties in central vision. However, apparent movement in peripheral vision is not clearly understood. This study focuses on the properties of the perception of apparent movement between central and peripheral vision. The results show that judgements of apparent movement in central vision indicate high performance at less than 4 degrees of spatial separation, and that judgements in peripheral vision indicate high performance at greater than 4 degrees. Evoked potentials associated with long-range apparent movement were also measured, and topographic maps were constructed to evaluate the active areas corresponding to visual apparent movement. The topographic maps show that the central regions are activated above 300 msec after the onset of the second apparent-movement stimulation. The results suggest that visual apparent movement occurs in the visual association area, or at higher levels in the central nervous system.

Pigeons’ Performances of a Radial-Arm-Maze Analog Task: Effect of Spatial Distinctiveness

Pigeons were presented with a radial-arm-maze analog task involving five response keys in one of four spatial arrangements. Two of the arrangements involved two-dimensional key displays that differed in degree of spatial separation (large display, Group L, vs. small display, Group S). The other two arrangements involved one-dimensional key displays in either a vertical (Group V) or a horizontal (Group H) array. Acquisition was faster for Groups L and S than for Groups V and H, however, the spatial separation for Group L did not further facilitate performance relative to Group S. Groups H and V performed poorly on this task. When delays were interpolated at different points in the trial, Group L made fewer errors when interrupted early and late in the trial, than when interrupted in the middle of the trial. This result suggests that pigeons in Group L used retrospective coding for choices made early in the trial and prospective coding for choices yet to be made late in the trial. Groups H and V showed flat, point-of-delay-interpolation error functions, a finding consistent with their poor overall performance. Half the birds in Group S performed similarly to Group L birds; the other half performed similarly to birds in Groups H and V.

Explaining the Paradox of Puerto Rican Segregation

Previous research has shown that Puerto Ricans are highly segregated from nonHispanic whites and moderately segregated from blacks, with socioeconomic factors having no effect on these patterns. These findings are opposite those observed for other Hispanic groups and contradict the fundamental tenets of ecological theory. This paper explains these anomalous patterns and brings results for Puerto Ricans into conformity with prior theory and research on residential segregation. The Puerto Rican anomaly stems from their very low SES and their black ancestry. Low social status leads directly to high segregation, while a high percent of blacks among Puerto Ricans draws them strongly towards residence near nonHispanic blacks. Since Anglos avoid living near blacks, Puerto Ricans become bystander victims of Anglos' racial prejudice, leading to their residential segregation in society. Several observers have noted the paradoxical nature of Puerto Rican residential segregation in New York City. Kantrowitz (a) pointed out that, unlike other ethnic groups, Puerto Ricans have a relatively low degree of spatial separation from blacks, but are highly segregated from native whites. His findings were echoed by those of Rosenberg and Lake, who found that Puerto Rican segregation did not fit either the assimilation model, derived from the presumed experience of European ethnics, or the ecological model of invasion and succession, which described the black experience. Specifically, Puerto Rican segregation did not decline as social distance from Anglos1 lessened, but on the other hand it was not based on an underlying process of rapid residential turnover either. In subsequent research, Massey (b,c,d) confirmed the existence of a distinctly Puerto Rican segregation pattern, one characterized by an unusually high degree

Transfer by Normal and Chronic Whole-Body Irradiated Monkeys of a Single Learned Discrimination along a Peripheral Cue Gradient

Abstract : Nine normal monkeys, three monkeys with previous focal-head irradiation of the posterior association areas, and two monkeys with previous focal-head irradiation of the frontal association areas were tested for transfer of a simple learned discrimination along a peripheral cue gradient. The results of the study demonstrated that: (1) There was no significant difference in performance between normal and chronic focal-head irradiated monkeys. (2) There was a significant change in performance as a function of degree of spatial separation between the relevant discriminanda and site of food reward. (Author)