We used near-infrared spectroscopy to examine dorsolateral prefrontal cortex (DLPFC) activation over time in 10 children with or at-risk-for developmental coordination disorder (DCD) and 11 typically ...developing children (ages 8–12) during tasks involving executive processing. The groups performed with similar accuracy on the Stroop and Wisconsin card sort (WCST), but their underlying neural activation differed. Typically developing children modulated DLPFC activity over time and showed rightward lateralization during Stroop but no lateralization during WCST. The DCD group exhibited high and sustained activation across hemispheres and tasks, which we suggest is a compensatory effort to maintain response accuracy.
•Define boundaries using GIS, image segmentation, and regionalization.•Integrate vector and raster data for regionalization to delineate spatial units.•Identify socio-environmental units for ...subsequent SES analysis and modeling.•Solve with open-source Python packages to improve reproducibility and replicability.
Regionalization has emerged as a crucial research area for the past 50 years, including aggregating smaller areas into larger, contiguous, and/or homogeneous regions. Spatial optimization techniques are advantageous for solving regionalization problems, yet their nondeterministic polynomial-time (NP) hard nature leads to computational complexity and time consumption, especially with extensive datasets. Although regionalization studies play a pivotal role in defining boundaries for multi-scalar analysis and modeling complex socio-environmental systems (SES), current approaches lack integrated consideration of raster and vector data. We introduce a unified, structured framework integrating Geographic Information Systems (GIS), image segmentation, and regionalization to identify and characterize socio-environmental units accounting for various data models and types. We use a public geodatabase of the Rio Grande/Bravo basin, an SES covering diverse cultures, ecosystems, and economies, to demonstrate the functionality of our newly developed method, which effectively identifies spatial units for subsequent SES analysis and modeling. The delineation process accounts for various factors, including administrative boundaries, estimated total quantities, compactness, spatial contiguity, and similarity in socio-environmental characteristics. To make this work reproducible, replicable, and expandable, we developed the approach entirely based on open-source Python packages. Our method is easily transferable to other research using various data formats and spatial scales to delineate spatial unit boundaries effectively and efficiently.
•We conducted a comparative analysis of carbon emissions and urban expansion indicators for the two empirical cities Xi’an and Chengdu in China.•We applied an extended STIRPAT model to quantify the ...impact of urban spatial expansion on carbon emissions.•Our analysis provides a more comprehensive and cohesive picture of the relationship between urban expansion and the reduction of carbon emissions.•Our empirical study using spatiotemporal and socioeconomic data highlights the importance of urban spatial structure for constructing low-carbon cities.
Rapidly expanding urban areas constitute places of high-intensity energy consumption and, hence, major carbon emissions. There is an urgent need to systematically review the relationship between urban spatial expansion and carbon emissions at the city level, especially for cities in western China where development lags behind compared to other parts of the country, and differences among resource availability exist. Here, we conducted a systematic comparative analysis of carbon emissions and urban expansion indicators for urban spatial development. We introduce and apply an extension of the STIRPAT model to quantify the impact of urban spatial expansion on carbon emissions for the cities of Xi’an and Chengdu located in western China. The model findings indicate that both cities have reached the absolute and relative goal of carbon emissions, although they experienced a sprawling pattern. Moreover, population density for both cities displayed a negative relationship with carbon emissions, whereas road area per capita displayed a positive relationship. Since western cities have a later starting point for development, the empirical research on influencing variables of carbon emissions for western cities is important to local and regional urban spatial planning and governance. We propose further empirical studies regarding the gaps of existing urban spatial structure and low-carbon urban areas, in order to construct a systematic and scientifically sound approach to further low-carbon strategies in urban development.
Africa has been a hotspot of rapid urban growth since 2000, yet no review exists that describes the current state of urban growth modeling. This review aims to fill this gap by synthesizing urban ...growth modeling approaches, input variables and challenges across Africa. Using Web of Science, Google Scholar, Geobase, and Compendex databases, we selected 49 studies that projected urban land use and cover change or modeled probabilities of future urban change associated with a variety of input variables. We found increasing trends in the numbers of studies employing cellular automata, statistical regression, agent-based, video prediction, and integrated approaches. The modeling approaches used and their corresponding increases differed across Africa. The input variables used to project urban growth also varied across subregions. Studies were biased towards populous countries rather than the most urbanized. 78 % of the studies focused on primary cities, while secondary cities were less frequently studied. Comparison of urban growth modeling across multiple regions and for different types of cities is currently difficult due to inconsistent definitions and limited availability of data and computational resources. We recommend that the scientific community develop consistent definitions of African city types and urban land use and land cover classifications, create regional urban land cover products for Africa, and build repositories of models and their input data.
•Input variables used in urban growth modeling vary across study areas in Africa.•Urban growth modeling studies in Africa are biased toward populous countries and primary cities.•Few studies in Africa have projected urban growth across multiple scales.•In Africa, consistent urban data to calibrate and validate urban growth models across multiple study areas are lacking.
Abstract
The role of disorder on physical systems has been widely studied in the macroscopic and microscopic world. While static disorder is well understood in many cases, the impact of ...time-dependent disorder on quantum gases is still poorly investigated. In our experimental setup, we introduce and characterize a method capable of producing time-controlled optical-speckle disorder. Experimentally, coherent light illuminates a combination of a static and a rotating diffuser, thereby collecting a spatially varying phase due to the diffusers’ structure and a temporally variable phase due to the relative rotation. Controlling the rotation of the diffuser allows changing the speckle realization or, for future work, the characteristic time scale of the change of the speckle pattern, i.e. the correlation time, matching typical time scales of the quantum gases investigated. We characterize the speckle pattern
ex-situ
by measuring its intensity distribution cross-correlating different intensity patterns.
In-situ
, we observe its impact on a molecular Bose–Einstein condensate (BEC) and cross-correlate the density distributions of BECs probed in different speckle realizations. As one diffuser rotates relative to the other around the common optical axis, we trace the optical speckle’s intensity cross-correlations and the quantum gas’ density cross-correlations. Our results show comparable outcomes for both measurement methods. The setup allows us to tune the disorder potential adapted to the characteristics of the quantum gas. These studies pave the way for investigating nonequilibrium physics in interacting quantum gases using controlled dynamical-disorder potentials.
The planned expansion of biofuel plantations in Brazil could potentially cause both direct and indirect land-use changes (e.g., biofuel plantations replace rangelands, which replace forests). In this ...study, we use a spatially explicit model to project land-use changes caused by that expansion in 2020, assuming that ethanol (biodiesel) production increases by 35 (4) x 10⁹ liter in the 2003-2020 period. Our simulations show that direct land-use changes will have a small impact on carbon emissions because most biofuel plantations would replace rangeland areas. However, indirect land-use changes, especially those pushing the rangeland frontier into the Amazonian forests, could offset the carbon savings from biofuels. Sugarcane ethanol and soybean biodiesel each contribute to nearly half of the projected indirect deforestation of 121,970 km² by 2020, creating a carbon debt that would take about 250 years to be repaid using these biofuels instead of fossil fuels. We also tested different crops that could serve as feedstock to fulfill Brazil's biodiesel demand and found that oil palm would cause the least land-use changes and associated carbon debt. The modeled livestock density increases by 0.09 head per hectare. But a higher increase of 0.13 head per hectare in the average livestock density throughout the country could avoid the indirect land-use changes caused by biofuels (even with soybean as the biodiesel feedstock), while still fulfilling all food and bioenergy demands. We suggest that a closer collaboration or strengthened institutional link between the biofuel and cattle-ranching sectors in the coming years is crucial for effective carbon savings from biofuels in Brazil.
In North America, a comparatively small number of Fraxinus (ash) cultivars were planted in large numbers in both urban and rural environments across the entire range of Fraxinus pennsylvanica Marsh ...(green ash) over the last 80 years. Undetected cultivar gene flow, if extensive, could significantly lower genetic diversity within populations, suppress differentiation between populations, generate interspecific admixture not driven by long-standing natural processes, and affect the impact of abiotic and biotic threats. In this investigation we generated the first range-wide genetic assessment of F. pennsylvanica to detect the extent of cultivar gene flow into natural stands. We used 16 EST-SSR markers to genotype 48 naturally regenerated populations of F. pennsylvanica distributed across the native range (1291 trees), 19 F. pennsylvanica cultivars, and one F. americana L. (white ash) cultivar to detect cultivar propagule dispersal into these populations. We detected first generation cultivar parentage with high confidence in 171 individuals in 34 of the 48 populations and extensive cultivar parentage (23-50%) in eight populations. The incidence of cultivar parentage was negatively associated with allele richness (R2 = 0.151, p = 0.006). The evidence for a locally high frequency of cultivar propagule dispersal and the interspecific admixture in eastern populations will inform Fraxinus gene pool conservation strategies and guide the selection of individuals for breeding programs focused on increasing resistance to the emerald ash borer (Agrilus planipennis Fairmaire), an existential threat to the Fraxinus species of North America.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The present paper uses data from the World Bank Enterprise Survey conducted in Turkey in 2005 to shed light on the firms that use intermediaries in international trade. It lends robust empirical ...support to recent theories which suggest that indirect exporters are mostly small firms that are not profitable enough to cover the high fixed costs of building an own distribution network abroad. Manufacturers who develop new products are more likely to use trade intermediaries, as are firms that produce low‐quality goods. In contrast, neither foreign ownership nor credit constraints are correlated with the choice of export mode. Moreover, firms that rely on trade intermediaries to sell their goods abroad also do so to source their foreign inputs, implying that the role of intermediaries in facilitating trade may be larger than previous studies suggest.
We investigate, both experimentally and theoretically, the static geometric properties of a harmonically trapped Bose-Einstein condensate of 6Li2 molecules in laser speckle potentials. ...Experimentally, we measure the in situ column density profiles and the corresponding transverse cloud widths over many laser speckle realizations. We compare the measured widths with a theory that is non-perturbative with respect to the disorder and includes quantum fluctuations. Importantly, for small disorder strengths we find quantitative agreement with the perturbative approach of Huang and Meng, which is based on Bogoliubov theory. For strong disorder our theory perfectly reproduces the geometric mean of the measured transverse widths. However, we also observe a systematic deviation of the individual measured widths from the theoretically predicted ones. In fact, the measured cloud aspect ratio monotonously decreases with increasing disorder strength, while the theory yields a constant ratio. We attribute this discrepancy to the utilized local density approximation, whose possible failure for strong disorder suggests a potential future improvement.
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