Spatial Demands Research Articles

Calmodulin complexes with brain and muscle creatine kinase peptides.

Calmodulin (CaM) is a ubiquitous Ca2+ sensing protein that binds to and modulates numerous target proteins and enzymes during cellular signaling processes. A large number of CaM-target complexes have been identified and structurally characterized, revealing a wide diversity of CaM-binding modes. A newly identified target is creatine kinase (CK), a central enzyme in cellular energy homeostasis. This study reports two high-resolution X-ray structures, determined to 1.24 ​Å and 1.43 ​Å resolution, of calmodulin in complex with peptides from human brain and muscle CK, respectively. Both complexes adopt a rare extended binding mode with an observed stoichiometry of 1:2 CaM:peptide, confirmed by isothermal titration calorimetry, suggesting that each CaM domain independently binds one CK peptide in a Ca2+-depended manner. While the overall binding mode is similar between the structures with muscle or brain-type CK peptides, the most significant difference is the opposite binding orientation of the peptides in the N-terminal domain. This may extrapolate into distinct binding modes and regulation of the full-length CK isoforms. The structural insights gained in this study strengthen the link between cellular energy homeostasis and Ca2+-mediated cell signaling and may shed light on ways by which cells can ‘fine tune’ their energy levels to match the spatial and temporal demands.

The underestimated role of small fragments for carnivore dispersal in the Atlantic Forest

Designing protected areas capable of supporting organism flow is critical for species persistence across wide scales. Here, we evaluated the capacity and protection level of forest fragments to sustain connectivity for carnivores in the Atlantic Forest. We simulated potential dispersal considering species spatial demands and quantified the importance of patches with different sizes in sustaining species movement. We found that patches smaller than species home-range size represented more than 95% of the patches used during species dispersal. These small remnants play a key role in upholding connectivity for carnivores, especially for species capable of moving long distances. Although the forest structure did support most species movements, our results showed that some species must cross matrices composed by crops and pasture to complete their trajectories. Moreover, between 29% and 70% of the area around the species' movement paths, which could act as potential corridors, overlap with human activities. Current established protected areas – mainly targeted for sustainable use – cover only 15% of the entire extension of small remnants enrolled in species dispersal. We reinforce that conservation efforts should not overlook the potential of small forest fragments to improve connectivity. Integrating key fragments with forest restoration and matrix management would benefit long-term species persistence.

Modeling Spatial Charging Demands Related to Electric Vehicles for Power Grid Planning Applications

The electrification of the transport sector together with an increasing share of renewable energies has the potential to reduce CO2 emissions significantly. This transformation requires the rollout of charging infrastructure, which has an impact on power grids. For grid planning and dimensioning purposes, it is crucial to assess this rapidly growing impact. We present an approach using socio-economic data such as income levels together with a model for demographic changes to estimate where electric mobility is likely to be concentrated, especially during the transformation phase. We present a total-cost-of-ownership approach for the ramp-up of electric mobility, considering an increased penetration of renewable energies. With the city of Wiesbaden in Germany as an example for an application area, the possible expansion of vehicle ownership and charging points is modeled on the level of individual buildings. Compared to a simpler approach, the detailed model results in more consistent charging point allocations, higher line/transformer loadings and lower bus voltages for the investigated grids. Predicting future distributions of charging points with such a level of detail in terms of ramp-up and spatial resolution proves potentially beneficial for grid analysis and planning purposes, especially in urban areas, where infrastructure changes are expensive and time-consuming.

시카고 도심부의 역사적 건축물 보존 및 활용 현황 고찰 : 미시건대로 역사지구를 중심으로

Purpose: This study aims to draw implications for promoting the preservation and reuse of historic buildings by examining the policies and programs and exploring the excellent remodeling cases of historic buildings in the Historic Michigan Boulevard District of the Chicago Loop. Method: The historic backgrounds and current status of the district were reviewed from the literature. The policies and programs of Chicago Department of Planning and Development to manage the historic buildings and guide the development were examined. The building database was built to trace the chronologies of all the buildings in the district. Furthermore, excellent preservation cases awarded by the Commission on Chicago Landmarks were explored to review specific examples. Result: The implications for promoting the preservation and reuse of the historic buildings can be summarized as follows. First, the integrated approach from urban planning is required to compromise the conflicts between preservation and development. Second, social consensus on the cultural value of historic buildings and economic incentives for the preservation are essential to attract voluntary participation from the building owners. Third, the conversions of building uses should be considered in response to the changes in spatial demands in the urban area.

The challenge of reproducing remote sensing data from satellites and unmanned aerial vehicles (UAVs) in the context of management zones and precision agriculture

Mapping the within-field variability of crop status is of great importance in precision agriculture, which seeks to balance agronomic inputs with spatial crop demands. Satellite imagery and the delineation of management zones based on remote sensing plays a key role. However, satellite imagery is dependent on a cloud-free view, which is especially challenging in temperate regions such as Northern Europe. This disadvantage can be overcome with unmanned aerial vehicles (UAV), which provide an alternative to satellites. An investigation was conducted to establish whether UAV imagery can generate similar crop heterogeneity maps to satellites (Sentinel 2) and the extent to which crop heterogeneity and management zones can be reproduced by repeated data collection within short time intervals. Three winter wheat fields were monitored during the growing season. Two vegetation indices (NDVI and MSAVI2) based on red and near-infrared (NIR) reflectance were calculated to delineate fields into five management zones based on NDVI raster maps using quintiles. The Pearson correlation coefficient, the Nash–Sutcliffe agreement coefficient and the smallest real difference coefficient (SRD), also called the reproducibility coefficient were used to evaluate the reproducibility. NDVI and MSAVI2 gave similar results, but NDVI was a slightly better descriptor of crop heterogeneity after canopy closure and NDVI was used for the remainder of the study. The results showed that substitution of satellite data with UAV data resulted in an average reclassification of 10 m by 10 m management zones corresponding to 58% of the total field area. Reclassification means that management pixels were classified differently according to origin of images. Repeated satellite and UAV imagery resulted in 39% and 47% reclassification, respectively. The results showed that the reproduction of remote sensing data with different sensor systems added more measurement error to measurements than was the case with repeated measurements using the same sensor systems. In this study, SRD averaged 2.5 management zones, which means that differences up to 2.5 management zones were within the measurement error. This paper discusses the practical aspects of these findings and clarifies that the reclassification of management zones is depending on the heterogeneity of the studied fields. Therefore, the achieved results may not be generalized but the presented methodology can be used in future studies.

The eye-mind wandering link: Identifying gaze indices of mind wandering across tasks.

During mind wandering, visual processing of external information is attenuated. Accordingly, mind wandering is associated with changes in gaze behaviors, albeit findings are inconsistent in the literature. This heterogeneity obfuscates a complete view of the moment-to-moment processing priorities of the visual system during mind wandering. We hypothesize that this observed heterogeneity is an effect of idiosyncrasy across tasks with varying spatial allocation demands, visual processing demands, and discourse processing demands and reflects a strategic, compensatory shift in how the visual system operates during mind wandering. We recorded eye movements and mind wandering (via thought-probes) as 132 college-aged adults completed a battery of 7 short (6 min) tasks with different visual demands. We found that for tasks requiring extensive sampling of the visual field, there were fewer fixations, and, depending on the specific task, fixations were longer and/or more dispersed. This suggests that visual sampling is sparser and potentially slower and more dispersed to compensate for the decreased sampling rate during mind wandering. For tasks that demand centrally focused gaze, mind wandering was accompanied by more exploratory eye movements, such as shorter and more dispersed fixations as well as larger saccades. Gaze behaviors were not reliably associated with mind wandering during a film comprehension task. These findings provide insight into how the visual system prioritizes external information when attention is focused inward and indicates the importance of task demands when assessing the relationship between eye movements, visual processing, and mind wandering. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Zone division and extraction of historic area based on big data

ABSTRACT Although zoning has great potential in coordinating regional development and destination management, it is challenging to derive an optimal zoning method in the historic district. To address this challenge, this paper proposes a zone division method attempting to balance tourists’ and residents’ spatial demands and realizing urban historic area sustainable development. A 3-zones (Tourist active zone, Local community zone, and Buffer zone) plan is put forward based on a case study of the Qianmen area in Beijing, China. Then zone extraction is conducted with two kinds of big data, Points of Interests (POI) and Mobile Phone Signal (MPS). The Thiessen polygon-based method to divide the tourists’ concentrated area and a fishnet-based density method to distinguish the area of residents mainly living are used to help identify borderlines of different zones. A survey map for tourists and residents is used to verify the zone extraction results. Subsequently, zone management strategies are suggested for different zones improvement. This discussion contributes to overcoming the traditional methods’ defects in subarea-scale research with scientifically sound and practical.

Anthropogenic drivers for exceptionally large meander formation during the Late Holocene

Large-amplitude meanders may form in low-energy rivers despite generally limited mobility in theses systems. Exceptionally large meanders which even extend beyond the valley sides have developed in the Overijsselse Vecht river (the Netherlands) between ca. 1400 CE (Common Era) and the early 1900s, when channelization occurred. Previous studies have attributed the enhanced lateral dynamics of this river to changes in river regime due to increased discharges, reflecting climate and/or land-use alterations in the catchment. This paper focuses on local aspects that may explain why exceptionally large meanders developed at specific sites. Through an integrated analysis based on archaeological, historical, and geomorphological data along with optically stimulated luminescence dating, we investigated the relative impact of three direct and indirect anthropogenic causes for the local morphological change and enhanced lateral migration rates: (1) lack of strategies to manage fluvial erosion; (2) a strong increase in the number of farmsteads and related intensified local land use from the High Middle Ages onwards; and (3) (human-induced) drift-sand activity directly adjacent to the river bends, causing a change in bank stability. Combined, these factors led locally to meander amplitudes well beyond the valley sides. Lessons learned at this site are relevant for management and restoration of meandering rivers in similar settings elsewhere, particularly in meeting the need to estimate spatial demands of (restored) low-energy fluvial systems and manage bank erosion.

Motor imagery and action observation for predictive control in developmental coordination disorder.

In 2019, international clinical practice recommendations on the definition, diagnosis, assessment, intervention, and psychosocial aspects of developmental coordination disorder (DCD) were published. Informing our understanding of mechanisms, recent systematic reviews have shown that children with DCD have difficulties with the predictive control of movements, including aspects of motor planning, which is expressed as the internal modeling deficit hypothesis. This motor control deficit is most evident when the spatial and temporal demands of a task increase. An increasing number of empirical studies suggest that motor planning problems can be remediated through training based on one or a combination of motor imagery and action observation. In this review, we show evidence of motor planning problems in children with DCD and show that task demands or complexity affects its appearance. Implications of these findings are treatments based on motor imagery and action observation to remediate motor planning issues. The article concludes with recommendations for future research.

Contextual Codes in the Hippocampus

The hippocampus is thought to support memory and decisions by binding relevant aspects of experiences within a context. A recent paper by Gulli et al. studies how activity in the macaque hippocampus varies according to different contextual requirements in the same space. This study demonstrates how a hippocampal cognitive map can flexibly reflect both spatial and nonspatial task demands.

A Study on the Calculation of Platform Sizes of Urban Rail Hub Stations Based on Passenger Behavior Characteristics

The Chinese national rail transit design specification decides the size of urban rail transit platforms in China. This suggested method treats passengers as homogeneous individuals when calculating the walking area within a platform. However, the heterogeneity of passenger behavior in a rail hub station has not been considered. It is not reasonable to see passengers as homogeneous individuals. In this study, by observing passenger behavior characteristics at rail hub platforms, two parameters were obtained, walking speed and luggage size. Passengers were then accordingly put into different groups, and dynamic spatial demands for each passenger group were calculated by parameter fitting functions. Based on the theory of spatiotemporal consumption, the nonlinear constraint model was constructed to determine the space-time consumption of each passenger group, and finally the area demands of different types of passengers were obtained for different time and passenger flows. An application was made to Beikezhan Station on Xi’an Metro line 2. The calculation results show the area demands ranges of four passenger groups with distinct characteristics, and their space-time consumption varied. The study can calculate the space demands for all passenger varieties within a rail hub transit platform and provide suggestions for the determination of the ideal walking area size of rail transit platforms.

Evaluating Spatial Scenarios for Sustainable Development in Quito, Ecuador

Peripheral urban sprawl configures new, extensive conurbations that transcend current administrative boundaries. Land use planning, supported by the analysis of future scenarios, is a guide to achieve sustainability in large metropolitan areas. To understand how urban sprawl is consuming natural and agricultural land, this paper analyzes land use changes in the metropolis of Quito, considering a combination of urban planning, natural conservation and risk areas. Using the Dyna-CLUE model we simulate spatial demands for future land uses by 2050, based on two growth scenarios: the trend scenario (unrestricted growth) and the regulated scenario, which considers two parameters—a government proposal for urban expansion areas and laws that protect natural areas. Both scenarios show how urban expansion consumes agricultural and natural areas. This expansion is backed by urban policies which do not sufficiently account for conservation areas nor for risk areas. Therefore, these simulations suggest that planning should follow a more holistic approach that explicitly considers urban growth beyond current administrative limits, in what we refer to as the New Metropolitan Area of Quito.

Increased error-correction leads to both higher levels of variability and adaptation

In order to intercept moving objects, we need to predict the spatiotemporal features of the motion of both the object and our hand. Our errors can result in updates of these predictions to benefit interceptions in the future (adaptation). Recent studies claim that task-relevant variability in baseline performance can help adapt to perturbations, because initial variability helps explore the spatial demands of the task. In this study, we examined whether this relationship is also found in interception (temporal domain) by looking at the link between the variability of hand-movement speed during baseline trials, and the adaptation to a temporal perturbation. 17 subjects performed an interception task on a graphic tablet with a stylus. A target moved from left to right or vice versa, with varying speed across trials. Participants were instructed to intercept this target with a straight forward movement of their hand. Their movements were represented by a cursor that was displayed on a screen above the tablet. To prevent online corrections we blocked the hand from view, and a part of the cursor's trajectory was occluded. After a baseline phase of 80 trials, a temporal delay of 100 ms was introduced to the cursor representing the hand (adaptation phase: 80 trials). This delay initially caused participants to miss the target, but they quickly accounted for these errors by adapting to most of the delay of the cursor. We found that variability in baseline movement velocity is a good predictor of temporal adaptation (defined as a combination of the rate of change and the asymptotic level of change after a perturbation), with higher variability during baseline being associated with better adaptation. However, cross-correlation results suggest that the increased variability is the result of increased error correction, rather than exploration.

Analogue x digital: Parallel techniques for design learning

Abstract With urban space under the ubiquitous scrutiny of digital visioning technologies, the city is now imaged by means of a pixel grid containing ephemeral, qualitative data presented as colour, brightness and shape. Unlike traditional analogue pictorial representational modes, the digital image is a highly transformable mechanism with an unstable distribution of data across its pixel array. As a consequence, representation in the form of spatial abstraction demands not only a new approach to the learning and implementation of traditional disciplinary drawing practice, but a rethinking of the alignment and cooperative nature of analogue and digital drawing models when applied to effective design development. In a pedagogical context, the transition of spatial representation between analogue and digital modes has profound implications for how the student connects seminal drawing and design processes to both the sensorial realm and the physical experience of lived space. This paper therefore explores the enhancement of tertiary learning in digital and abstract literacy through new drawing techniques. Underpinned by a new relationship between representation and envisioned physical space, the techniques are applied within learning environments in parallel with existing analogue pictorial procedures. By building curriculum for foundational students that provides a framework of linked spatial experiences aligned across analogue and digital domains and coupled with tasks focused on the development of conceptual thinking, it proposes increased student success in future studios and professional practice.

Harmonizing 3GPP and NFV Description Models: Providing Customized RAN Slices in 5G Networks

The standardization of Radio Access Network (RAN) in mobile networks has traditionally been led by 3GPP. However, the emergence of RAN slicing has introduced new aspects that fall outside 3GPP scope. Among them, network virtualization enables the particularization of multiple RAN behaviors over a common physical infrastructure. Using Virtualized Network Functions (VNFs) that comprise customized radio functionalities, each virtualized RAN, denominated RAN slice, could meet its specific requirements. Although 3GPP specifies the description model to manage RAN slices, it can neither particularize the behavior of a RAN slice nor leverage the NFV descriptors to define how its VNFs can accommodate its spatial and temporal traffic demands. In this article, we propose a description model that harmonizes 3GPP and ETSI-NFV viewpoints to manage RAN slices. The proposed model enables the translation of RAN slice requirements into customized virtualized radio functionalities defined through NFV descriptors. To clarify this proposal, we provide an example where three RAN slices with disruptive requirements are described following our solution.

Comparative analysis of the shape and size of the middle ear cavity of turtles reveals no correlation with habitat ecology

The middle ear of turtles differs from other reptiles in being separated into two distinct compartments. Several ideas have been proposed as to why the middle ear is compartmentalized in turtles, most suggesting a relationship with underwater hearing. Extant turtle species span fully marine to strictly terrestrial habitats, and ecomorphological hypotheses of turtle hearing predict that this should correlate with variation in the structure of the middle ear due to differences in the fluid properties of water and air. We investigate the shape and size of the air-filled middle ear cavity of 56 extant turtles using 3D data and phylogenetic comparative analysis to test for correlations between habitat preferences and the shape and size of the middle ear cavity. Only weak correlations are found between middle ear cavity size and ecology, with aquatic taxa having proportionally smaller cavity volumes. The middle ear cavity of turtles exhibits high shape diversity among species, but we found no relationship between this shape variation and ecology. Surprisingly, the estimated acoustic transformer ratio, a key functional parameter of impedance-matching ears in vertebrates, also shows no relation to habitat preferences (aquatic/terrestrial) in turtles. We suggest that middle ear cavity shape may be controlled by factors unrelated to hearing, such as the spatial demands of surrounding cranial structures. A review of the fossil record suggests that the modern turtle ear evolved during the Early to Middle Jurassic in stem turtles broadly adapted to freshwater and terrestrial settings. This, combined with our finding that evolutionary transitions between habitats caused only weak evolutionary changes in middle ear structure, suggests that tympanic hearing in turtles evolved as a compromise between subaerial and underwater hearing.

Has Cuba exposed the myth of “free” solar power? Energy, space, and justice

Given the many problems with fossil energy, the fact that solar energy still only constitutes an insignificant fraction of global energy use requires explanation. The most common explanation is that multinational corporations with vested interests in fossil fuels have been actively preventing the development of solar energy technologies. But this explanation is difficult to apply to the case of Cuba. This article takes Cuban energy policy since the 1990s as a starting point to understand the sociometabolic prerequisites of a renewable energy transition. In 2014, Cuba embarked on a new renewable energy strategy while 95% of the island’s electricity was still generated from petroleum products. To explain Cuba’s halting renewable energy transition, we demonstrate that modern energy technologies are always embedded in global flows of resources and processes of capital accumulation. The requisite investments of capital and labor in energy technology represent substantial, indirect land requirements beyond the space occupied by the technological infrastructure itself. The theoretical argument is that energy technologies should be perceived not simply as local, politically neutral accomplishments of engineering but as sociometabolic displacement strategies, appropriating space from elsewhere. From an interdisciplinary perspective, this means that assessments of a technology’s “power density” also need to consider the spatial demands of the global economic context that makes the technology feasible. The Cuban case illustrates how visions of a renewable energy transition in both mainstream and Marxist thought will need to be based on a radically transformed ontology of technology attentive to global political economy and energy justice. Ultimately, the global anticipation of a transition to renewable energy implicates illusory assumptions about “technology” that have been taken for granted since the Industrial Revolution.

Cloud computing-based high accuracy surface modeling method for China’s Poyang Lake basin DEM generation

The increasing availability of big spatial data demands large-scale surface modeling methods. To find a solution for large-scale surface modeling problem, based on previously developed high accuracy surface modeling (HASM) method, an extended high accuracy surface modeling method utilizing cloud computing is developed. The developed method was run on a Hadoop-based cloud computing environment comprising four computers and applied for China’s Poyang Lake basin digital elevation model construction. The experiments results indicate that the cloud computing-based method outperforms the general sequential method based on single computer significantly and attains three times speedups. Furthermore, the improved schedule algorithm for cloud computing-based HASM has further accelerated the computing speed.

Stilling wave basins for overtopping reduction at an urban vertical seawall – The Kordon seawall at Izmir

Reduction of wave overtopping at urban coastal structures is a significant concern as uncontrolled flooding, and the wave forces disrupt the daily flow of the urban life causing damage to people, structures and economy. However, the design of these structures needs to consider the spatial and visual demands of the urban function that restrict the crest heights. Therefore, crest modifications such as a storm wall, a bullnose or a combined structure like Stilling Wave Basin (SWB) can be used to optimize the crest height for lower overtopping values. Although reduction factors of these modifications have been studied for sloped structures in EurOtop (2016), there is relatively limited dataset regarding the vertical structures. This paper presents the results of wave overtopping experiments for an urban vertical wall with low crested Stilling Wave Basin structure with foreshore, under impulsive wave conditions. Over 150 tests have been carried out using a model of a seawall and promenade combined structure based on the urban vertical seawall of Kordon, Izmir. A variety of design parameters such as the pattern of gaps, blocking coefficients, and promenade are investigated under constant hydraulic conditions to optimize SWB design for this urban vertical wall structure. The hydrodynamic conditions for overtopping experiments are designed to test the applicability of the empirical formulas of overtopping over vertical walls for impulsive waves in EurOtop (2016). A method, calculating reduction factors, is determined for the finalized SWB design for a broader spectrum of hydraulic boundary conditions (0.40≤Hm0/dw≤0.90, 1.22≤Tm−1,0≤2.02s, and 0.106≤dw≤0.20m) of the impulsive wave with 0.708<Rc/Hm0<2.091.

Advanced spatial knowledge of target location eliminates age-related differences in early sensorimotor learning.

Motor learning has been shown to decline in healthy aging, particularly in the early stages of acquisition. There is now ample evidence that motor learning relies on multiple interacting learning processes that operate on different timescales, but the specific cognitive mechanisms that contribute to motor learning remain unclear. Working memory resources appear to be particularly important during the early stages of motor learning, and declines in early motor learning have been associated with working memory performance in older adults. We examined whether age differences in the early stages of motor learning could be reduced or eliminated by reducing the spatial working memory demands during a force-field adaptation task. Groups of younger and older adults made center-out reaching movements to spatial targets either in a repeating four-element sequence, or in a random order. Participants also performed a battery of cognitive tests to further investigate the potential involvement of associative memory, spatial working memory, and procedural learning mechanisms in the early stage of motor learning. Although all groups adapted their movements equally well by the end of the learning phase, older adults only adapted as quickly as younger adults in the sequence condition, with the older adults in the random group exhibiting slower learning in the earliest stage of motor learning. Across all participants, early motor learning performance was correlated with recognition memory performance on an associative memory test. Within the younger random group, who were able to adapt as quickly as the sequence groups, early motor learning performance was also correlated with performance on a test of procedural learning. These findings suggest that age differences in early stages of motor learning can be eliminated if the spatial working memory demands involved in a motor learning task are limited. Moreover, the results suggest that multiple cognitive resources may be utilized during the early stage of learning, and younger adults may be more flexible than older adults in the recruitment of additional cognitive resources to support learning when spatial working memory demands are high.