Prehypertensive blood pressures and regional cerebral blood flow independently relate to cognitive performance in midlife

Background High blood pressure is thought to contribute to dementia in late life, but our understanding of the relationship between individual differences in blood pressure ( BP ) and cognitive functioning is incomplete. In this study, cognitive performance in nonhypertensive midlife adults was examined as a function of resting BP and regional cerebral blood flow ( rCBF ) responses during cognitive testing. We hypothesized that BP would be negatively related to cognitive performance and that cognitive performance would also be related to rCBF responses within areas related to BP control. We explored whether deficits related to systolic BP might be explained by rCBF responses to mental challenge. Methods and Results Healthy midlife participants (n=227) received neuropsychological testing and performed cognitive tasks in a magnetic resonance imaging scanner. A pseudocontinuous arterial spin labeling sequence assessed rCBF in brain areas related to BP in prior studies. Systolic BP was negatively related to 4 of 5 neuropsychological factors (standardized β&gt;0.13): memory, working memory, executive function, and mental efficiency. The rCBF in 2 brain regions of interest was similarly related to memory, executive function, and working memory (standardized β&gt;0.17); however, rCBF responses did not explain the relationship between resting systolic BP and cognitive performance. Conclusions Relationships at midlife between prehypertensive levels of systolic BP and both cognitive and brain function were modest but suggested the possible value of midlife intervention. </jats:sec

Control and Manipulation of Cold Atoms in Optical Tweezers

Neutral atoms trapped by laser light are amongst the most promising candidates for storing and processing information in a quantum computer or simulator. The application certainly calls for a scalable and flexible scheme for addressing and manipulating the atoms. We have now made this a reality by implementing a fast and versatile method to dynamically control the position of neutral atoms trapped in optical tweezers. The tweezers result from a spatial light modulator (SLM) controlling and shaping a large number of optical dipole-force traps. Trapped atoms adapt to any change in the potential landscape, such that one can re-arrange and randomly access individual sites within atom-trap arrays.Comment: 6 pages, 4 figure

Investigating retail property market dynamics through spatial accessibility measures

Purpose The retail property market is constantly adopting to the continuous demand of retailers and their consumers. This paper aims to investigate retail property market dynamics through spatial accessibility measures of the City of York street network. It explores how spatial accessibility metrics (SAM) explain retail market dynamics (RMD) through changes in the city’s retail rental values and stock. Design/methodology/approach Valuation office agency (VOA) data sets (aspatial) and ordnance survey map (spatial) data form the empirical foundation for this investigation. Changes in rental value and retail stock between 2010 and 2017 VOA data sets represent the RMD variables. While, the configured street network measures of Space Syntax, namely, global integration, local integration, global choice and normalised angular choice form the SAM variables. The relationship between these variables is analysed through geo-visualisation and statistical testing using GIS and SPSS tools. Findings The study reveals that there has been an overall negative changes of 15 and 22% in rental value and retail stock, respectively, even though some locations within the sampled city (York, North Yorkshire, England) indicated positive changes. The study further indicated that changes in retail rental value and stock have occurred within locations with good accessibility index. It also verifies that there are spatial and statistical relationship between variables and 22% of RMD variability was jointly accounted for by SAM. Originality/value This research is first to investigates changes in retail property market variables through spatial accessibility measures of space syntax. It contributes to the burgeoning research field of real estate and Space Syntax

Computational Topology Techniques for Characterizing Time-Series Data

Topological data analysis (TDA), while abstract, allows a characterization of time-series data obtained from nonlinear and complex dynamical systems. Though it is surprising that such an abstract measure of structure - counting pieces and holes - could be useful for real-world data, TDA lets us compare different systems, and even do membership testing or change-point detection. However, TDA is computationally expensive and involves a number of free parameters. This complexity can be obviated by coarse-graining, using a construct called the witness complex. The parametric dependence gives rise to the concept of persistent homology: how shape changes with scale. Its results allow us to distinguish time-series data from different systems - e.g., the same note played on different musical instruments.Comment: 12 pages, 6 Figures, 1 Table, The Sixteenth International Symposium on Intelligent Data Analysis (IDA 2017

Early Holocene fauna from a new subfossil site: A first assessment from Christmas River, south central Madagascar

We report on faunal remains recovered during recent explorations at &#8216;Christmas River&#8217;, the only subfossil locality known from Madagascar&#8217;s south central plateau. Recovered remains of several extinct taxa date to approximately 10,000 14C years before present (BP), including crocodiles, tortoises, the elephant bird Aepyornis, the carnivoran Cryptoprocta spelea, the lemurs Archaeolemur majori, Pachylemur insignis, and Megaladapis edwardsi, and abundant remains of the dwarf hippopotamus, Hippopotamus lemerlei. The presence of southern - limited, forest - dependent species at Christmas River supports the hypothesis that forest once extended, perhaps discontinuously, across the central highlands towards the west. One theory is that sites in the north central highlands, which are higher in elevation, maintained more mesic conditions during Plio - Quaternary climate shifts than those of the lower elevation sites of the south central highlands. Thus, elevation above sea level may have acted as a filter that limited species dispersal across the island in the past. Such a scenario would explain the distinction between more humid, higher elevation, northern highland subfossil communities versus more arid, lower elevation, southern subfossil communities. Continued exploration at Christmas River thus provides a remarkable opportunity for deciphering ecological changes that have taken place in south central Madagascar during the Holocene.R&#201;SUM&#201;Madagascar est reconnue comme l&#8217;une des r&#233;gions les plus sensibles du monde en ce qui concerne les menaces pesant sur sa biodiversit&#233;, et cela &#224; cause de niveaux d&#8217;end&#233;misme in&#233;gal&#233;s, d&#8217;une diversit&#233; vari&#233;e et d&#8217;un impact humain important sur l&#8217;environnement. Suite &#224; la colonisation par l&#8217;Homme il y a plus de 2000 ans, des extinctions de masse de la faune et un important recul forestier ont eu lieu en laissant des marques sur les &#233;cosyst&#232;mes modernes qui sont dans un &#233;tat de bouleversement &#233;cologique. Certaines plantes end&#233;miques, par exemple, ont perdu d&#8217;importantes esp&#232;ces mutualistes, des animaux ont &#233;t&#233; oblig&#233;s d&#8217;exploiter d&#8217;autres ressources ou habiter des endroits auxquels ils sont mal adapt&#233;s. La diversit&#233; des plantes et des animaux a diminu&#233;, est menac&#233;e ou a m&#234;me compl&#232;tement disparue de certaines routes de diss&#233;mination. Bien que l&#8217;Homme soit largement incrimin&#233; dans son r&#244;le de d&#233;clencheur de ces extinctions massives, les transformations anthropiques qui ont contribu&#233; au changement du climat sont controvers&#233;es. Les hautes - terres de Madagascar sont actuellement domin&#233;es par des zones herbeuses &#233;tendues qui agissent comme des barri&#232;res emp&#234;chant les mouvements de la faune de part et d&#8217;autre de l&#8217;&#238;le. Nous sugg&#233;rons qu&#8217;une for&#234;t humide plus ou moins continue devait s&#8217;&#233;tendre sur les hautes-terres. Des informations pal&#233;o&#233;cologiques des hautes - terres du Centre sud sont&#232;n&#233;cessaires pour &#233;valuer cette hypoth&#232;se afin de d&#233;m&#234;ler la contribution relative des facteurs climatiques et anthropiques dans les changements pal&#233;o&#233;cologiques de la r&#233;gion. Cependant, les stations de subfossiles &#233;taient jusqu&#8217;alors inconnues dans cette r&#233;gion. Nous pr&#233;sentons ici les r&#233;sultats de recherches r&#233;alis&#233;es sur les restes fauniques d&#233;couverts au cours de fouilles r&#233;centes &#224; Christmas River, la seule station de subfossiles connue des hautes - terres du Centre sud de Madagascar. Des restes de plusieurs esp&#232;ces datant approximativement de 10,000 14C B.P. ont &#233;t&#233; identifi&#233;s dont des restes appartenant &#224; des esp&#232;ces de crocodile, de tortue, de l&#8217;Aepyornis, du carnivore Cryptoprocta spelea, des l&#233;muriens Archaeolemur majori, Pachylemur insignis et Megaladapis edwardsi ainsi que de nombreux restes de l&#8217;hippopotame nain Hippopotamus lemerlei. La pr&#233;sence &#224; Christmas River d&#8217;esp&#232;ces sylvicoles end&#233;miques du Sud appuie l&#8217;hypoth&#232;se de l&#8217;existence d&#8217;une for&#234;t, certainement discontinue, mais qui s&#8217;&#233;tendait sur les hautes - terres centrales en se poursuivant vers l&#8217;ouest. Une th&#233;orie a propos&#233; que les sites septentrionaux des hautes - terres centrales, &#224; des altitudes plus &#233;lev&#233;es, maintenaient des conditions plus humides au cours des changements du Plio - quaternaire que les sites m&#233;ridionaux de ces hautes - terres centrales. Ainsi, dans le pass&#233;, l&#8217;altitude a du agir comme un filtre qui emp&#234;chait la dispersion des esp&#232;ces d&#8217;un endroit &#224; l&#8217;autre de l&#8217;&#238;le. Un tel sc&#233;nario expliquerait la distinction entre les communaut&#233;s subfossiles du nord des hautes - terres qui &#233;taient plus humides &#224; haute altitude et les communaut&#233;s subfossiles du sud aride &#224; basse altitude. La poursuite de l&#8217;exploration &#224; Christmas River constitue une occasion unique pour d&#233;coder les changements &#233;cologiques qui sont intervenus dans le Sud de cette r&#233;gion centrale de Madagascar au cours de l&#8217;Holoc&#232;ne

Investigating retail space performance through spatial configuration of consumer movement: A Comparison of York and Leeds

Spatial layouts help to shape retail consumer movement, which in turn plays a role in determining the distribution of retailers and performance of retail space on city network. Spatial configuration can be understood through street segment analysis, computing to-movement (integration) and through-movement (choice) metrics within a given set of connecting street networks, making it possible to assign syntactic values to individual street segments (space). In this paper, such syntactic values for the cities of Leeds and York have been established to indicate a spatial accessibility index that can be used to understand potential human (consumer) movement on spatial layouts. Other studies have established relationships between computed syntactic values and ranges of socio-economic activities, including land uses and urban value distributions. However, little is known about how configured (movement) metric outputs relate to changes in retail space’s rental values (as proxy for retail space performance) across different city network scales. In response, this study investigates the relationship between retail space performance and consumer movement patterns (CMP) within sampled spatial layouts. The CMP are defined as spatial configuration metric outputs of integration, choice and normalised angular choice (NACH) metrics, computed at macro (city) and meso (city centre) scales. Street segment analysis on spatial layouts at city (macro) and city-centre (meso) scales were computed using DepthMapX tool to obtain the CMP variables. The computed syntactic values of CMP variables were then exported as point features into QGIS for analysis with the retail space performance within the sampled spatial layouts. Rental value data for years 2010 and 2017 were obtained from the Valuation Office Agency VOA datasets for York and Leeds. The two datasets were linked through a common key variable (Unique Address Reference Number) to compute rental value changes using MS Access and MS Excel tools. The rental value change table was also exported as point features into QGIS for geospatial analysis with the computed syntactic values of CMP variables. To achieve this, the study utilises vector grid (developed at 500m X 500m at city scale, and 200m X 200m at city centre scale for both cities) to a create uniform platform for all variables per grid. The relationship outputs between variables were investigated at macro city scale and meso city-centre scale for the two cities. The study reveals that there are variations in relationships between retail space performance and computed movement syntax across different scales of spatial layouts. The variables exhibit significant positive relationships at mesoscale (city centre), while variables exhibit weak correlation at the macroscale (city) for both cities. It further reveals that the integration (to-movement) metric has the most significant impact on retail space performance, with the through-movement metric having the least impact across all spatial layouts. On this basis, the study conclude that integration metric has the capability of signalling future of retail space (rental value) performance at city mesoscale layouts

A quasi-diagonal approach to the estimation of Lyapunov spectra for spatio-temporal systems from multivariate time series

We describe methods of estimating the entire Lyapunov spectrum of a spatially extended system from multivariate time-series observations. Provided that the coupling in the system is short range, the Jacobian has a banded structure and can be estimated using spatially localised reconstructions in low embedding dimensions. This circumvents the ``curse of dimensionality'' that prevents the accurate reconstruction of high-dimensional dynamics from observed time series. The technique is illustrated using coupled map lattices as prototype models for spatio-temporal chaos and is found to work even when the coupling is not strictly local but only exponentially decaying.Comment: 13 pages, LaTeX (RevTeX), 13 Postscript figs, to be submitted to Phys.Rev.

Towards Attaining Sustainable Retail Property Locations: The Relationships between Supply, Demand, and Accessibility of Retail Spaces

This study explored retail location performance of cities by investigating relationships between changes in retail property stock (supply), changes in retail rental value (demand), and spatial accessibility (retail consumer movement) across three UK cities, namely, Leeds, Newcastle, and York. This is to understand how retail locations and assets can be managed sustainably. In this sense, sustainability was considered through a dual focus in this paper: (1) the efficient use of retail property assets for economic purposes and (2) the impact of these physical retail assets on the local environment in terms of carbon footprint. The study relied on space syntax ideology in computing spatial accessibility index and adopted business rate datasets in computing changes in retail rental value and stock. Findings showed that spatial accessibility across retail locations could predict the performance of retail rental value (but not stock) across the sampled cities. The study further showed that extent of city analysis (scale) is significant in estimating retail location performance and understanding the influence of accessibility. This evidence has the potential to facilitate better decision-making concerning the planning, design, and management of retail locations and spaces. The study is significant because it can serve as a reference for promoting an urban sustainability agenda, especially in ensuring that urban land and properties are used optimally to maximise their social, economic, and environmental values

Primate Energy eExpenditure and Life History

Humans and other primates are distinct among placental mammals in having exceptionally slow rates of growth, reproduction, and aging. Primates’ slow life history schedules are generally thought to reflect an evolved strategy of allocating energy away from growth and reproduction and toward somatic investment, particularly to the development and maintenance of large brains. Here we examine an alternative explanation: that primates’ slow life histories reflect low total energy expenditure (TEE) (kilocalories per day) relative to other placental mammals. We compared doubly labeled water measurements of TEE among 17 primate species with similar measures for other placental mammals. We found that primates use remarkably little energy each day, expending on average only 50% of the energy expected for a placental mammal of similar mass. Such large differences in TEE are not easily explained by differences in physical activity, and instead appear to reflect systemic metabolic adaptation for low energy expenditures in primates. Indeed, comparisons of wild and captive primate populations indicate similar levels of energy expenditure. Broad interspecific comparisons of growth, reproduction, and maximum life span indicate that primates’ slow metabolic rates contribute to their characteristically slow life histories