Spatial Response Patterns Research Articles

Mantled Howler Monkeys (Alouatta palliata) in a Costa Rican Forest Fragment Do Not Modify Activity Budgets or Spatial Cohesion in Response to Anthropogenic Edges

Forest fragmentation increases forest edge relative to forest interior, with lower vegetation quality common for primates in edge zones. Because most primates live in human-modified tropical forests within 1 km of their edges, it is critical to understand how primates cope with edge effects. Few studies have investigated how primates inhabiting a fragment alter their behaviour across forest edge and interior zones. Here we investigate how anthropogenic edges affect the activity and spatial cohesion of mantled howler monkeys (Alouatta palliata) at the La Suerte Biological Research Station (LSBRS), a Costa Rican forest fragment. We predicted the monkeys would spend greater proportions of their activity budget feeding and resting and a lower proportion travelling in edge compared to forest interior to compensate for lower resource availability in the edge. We also predicted that spatial cohesion would be lower in the edge to mitigate feeding competition. We collected data on activity and spatial cohesion (nearest neighbour distance; number of individuals within 5 m) in forest edge and interior zones via instantaneous sampling of focal animals. Contrary to predictions, the monkeys spent equal proportions of time feeding, resting and travelling in forest edge and interior. Similarly, there were no biologically meaningful differences in the number of individuals or the distance between nearest neighbours in the edge (1.0 individuals; 1.56 m) versus the interior (0.8 individuals; 1.73 m). Our results indicate that A. palliata at LSBRS do not adjust their activity or spatial cohesion patterns in response to anthropogenic edge effects, suggesting that the monkeys here exhibit less behavioural flexibility than A. palliata at some other sites. To develop effective primate conservation plans, it is therefore crucial to study primate species’ responses to fragmentation across their geographic range.

Deforestation Impacts on Orographic Precipitation in the Tropical Andes

This study examines the implications of Tropical Montane Forests (TMFs) loss on orographic precipitation in the Eastern slopes of the Andes (EADS). The focus is on moist processes for synoptic regimes associated with significant EADS precipitation: (1) monsoon rainfall for weak and strong South America Low-Level Jet (LLJ) conditions and (2) heavy rainfall associated with cold air intrusions (CAI) in the dry season. High-resolution simulations using the Weather Research and Forecasting (WRF) model were conducted for realistic and modified land-cover resulting from the conversion of TMFs to savanna. The deforestation scenarios result in 50–100% decrease (up to ∼400 J kg–1) in Convective Available Potential Energy (CAPE) spatially organized by land-cover change along the EADS. Analysis of the differences in simulated frequency distributions of rainfall intensity shows robust daytime increases in light rainfall (<2 mm h–1) and decreases in moderate rainfall rates (2–10 mm h–1) in the altitudinal band 500–2,000 m where orographic enhancement is dominant. Whereas there are negligible changes in the spatial patterns of precipitation and hydrologic response for monsoon conditions, rainfall accumulations decrease for all cases, and the precipitation maxima shift downslope into the Amazon lowlands. Changes in rainfall amount and intensity result in runoff decreases of 5–10% at the event-scale for the CAI case. Sensitivity simulations for lower initial soil moisture conditions indicate a strong positive feedback of forest loss to hydrologic drought along the EADS foothills in the austral spring when CAIs play a key role in the tropical EADS dry season hydrometeorology.

Color Space Geometry Uncovered with Magnetoencephalography

The geometry that describes the relationship among colors, and the neural mechanisms that support color vision, are unsettled. Here, we use multivariate analyses of measurements of brain activity obtained with magnetoencephalography to reverse-engineer a geometry of the neural representation of color space. The analyses depend upon determining similarity relationships among the spatial patterns of neural responses to different colors and assessing how these relationships change in time. We evaluate the approach by relating the results to universal patterns in color naming. Two prominent patterns of color naming could be accounted for by the decoding results: the greater precision in naming warm colors compared to cool colors evident by an interaction of hue and lightness, and the preeminence among colors of reddish hues. Additional experiments showed that classifiers trained on responses to color words could decode color from data obtained using colored stimuli, but only at relatively long delays after stimulus onset. These results provide evidence that perceptual representations can give rise to semantic representations, but not the reverse. Taken together, the results uncover a dynamic geometry that provides neural correlates for color appearance and generates new hypotheses about the structure of color space.

Dendroclimatology of sugar maple (Acer saccharum): Climate-growth response in a late-successional species

Sugar maple (Acer saccharum) is a shade-tolerant, late successional dominant species in the North American eastern deciduous forest. The objective of this study was to quantify the relationship between climate and radial growth in sugar maple and to identify spatial and temporal patterns in dendroclimatic response. We used a combination of archived sugar maple tree-ring chronologies and newly sampled sites to calculate dendroclimatic response of sugar maple at 13 sites in the United States and Canada. At all sites, sugar maple growth was significantly correlated to monthly temperature, precipitation, or Palmer Drought Severity Index. However, there were no generalizable patterns in sugar maple’s growth response to climate. Individual sites had unique dendroclimatic responses with respect to: a) which climatic variables were correlated to radial growth; b) what months had significant correlations between climate and radial growth; and c) what years had significant correlations between climate and radial growth. The individualistic dendroclimatic response of sugar maple appears to reflect a plastic response of the species to changes in climate perhaps related to its status as a strong competitor in late-successional forests. This ability to survive a wide range of environmental conditions may bode well for the species persistence under variable future climatic conditions. It also points to the need for more research on late-successional species in examining forest response to potential climate change scenarios because these species may be more resilient than early-successional species.

Uncertainty Quantification of Mode Shape Variation Utilizing Multi-Level Multi-Response Gaussian Process

Abstract Mode shape information plays the essential role in deciding the spatial pattern of vibratory response of a structure. The uncertainty quantification of mode shape, i.e., predicting mode shape variation when the structure is subjected to uncertainty, can provide guidance for robust design and control. Nevertheless, computational efficiency is a challenging issue. Direct Monte Carlo simulation is unlikely to be feasible especially for a complex structure with a large number of degrees-of-freedom. In this research, we develop a new probabilistic framework built upon the Gaussian process meta-modeling architecture to analyze mode shape variation. To expedite the generation of input data set for meta-model establishment, a multi-level strategy is adopted which can blend a large amount of low-fidelity data acquired from order-reduced analysis with a small amount of high-fidelity data produced by high-dimensional full finite element analysis. To take advantage of the intrinsic relation of spatial distribution of mode shape, a multi-response strategy is incorporated to predict mode shape variation at different locations simultaneously. These yield a multi-level, multi-response Gaussian process that can efficiently and accurately quantify the effect of structural uncertainty to mode shape variation. Comprehensive case studies are carried out for demonstration and validation.

Processing communicative facial and vocal cues in the superior temporal sulcus

Facial and vocal cues provide critical social information about other humans, including their emotional and attentional states and the content of their speech. Recent work has shown that the face-responsive region of posterior superior temporal sulcus (“fSTS”) also responds strongly to vocal sounds. Here, we investigate the functional role of this region and the broader STS by measuring responses to a range of face movements, vocal sounds, and hand movements using fMRI. We find that the fSTS responds broadly to different types of audio and visual face action, including both richly social communicative actions, as well as minimally social noncommunicative actions, ruling out hypotheses of specialization for processing speech signals, or communicative signals more generally. Strikingly, however, responses to hand movements were very low, whether communicative or not, indicating a specific role in the analysis of face actions (facial and vocal), not a general role in the perception of any human action. Furthermore, spatial patterns of response in this region were able to decode communicative from noncommunicative face actions, both within and across modality (facial/vocal cues), indicating sensitivity to an abstract social dimension. These functional properties of the fSTS contrast with a region of middle STS that has a selective, largely unimodal auditory response to speech sounds over both communicative and noncommunicative vocal nonspeech sounds, and nonvocal sounds. Region of interest analyses were corroborated by a data-driven independent component analysis, identifying face-voice and auditory speech responses as dominant sources of voxelwise variance across the STS. These results suggest that the STS contains separate processing streams for the audiovisual analysis of face actions and auditory speech processing.

The Impact of Reforestation Induced Land Cover Change (1990–2017) on Flood Peak Discharge Using HEC-HMS Hydrological Model and Satellite Observations: A Study in Two Mountain Basins, China

Understanding the effect of land use and land cover (LULC) type change on watershed hydrological response is essential for adopting applicable measures to control floods. In China, the Grain to Green Program (GTGP) and the Natural Forest Conservation Program (NFCP) have had a substantial impact on LULC. We investigate the effect of these conservation efforts on flood peak discharge in two mountainous catchments. We used a series of Landsat images ranging from 1990 to 2016/2017 to evaluate the LULC changes. Further to this, the hydrological responses at the basin and sub-basin scale were generated by the Hydrologic Modeling System (HEC-HMS) under four LULC scenarios. Between 1990 and 2016/2017, both catchments experienced an increase in forest and urban land by 18% and 2% in Yanhe and by 16% and 8% in Guangyuan, respectively. In contrast, the agricultural land decreased by approximately 30% in Yanhe and 24% in Guangyuan, respectively. The changes in land cover resulted in decrease in flood peak discharge ranging from 14% in Yanhe to 6% in Guangyuan. These findings provide a better understanding on the impact of reforestation induced LULC change on spatial patterns of typical hydrological responses of mountainous catchment and could help to mitigate flash flood hazards in other mountainous regions.

Informing hydrological models of poorly gauged river catchments – A parameter regionalization and calibration approach

Development of robust hydrologic-hydrodynamic simulation models is challenging, especially in regions, where in-situ observation data are scarce. Parameter calibration is often a necessary and data-demanding step. Moreover, good calibration performance does not guarantee predictive skill in neighboring geographic regions or new time periods and scenarios. A robust calibration strategy is necessary and must apply an informed parameter regionalization approach, which can transfer parameter values from gauged to ungauged subcatchments, whilst accounting for data availability and quality. In this study, a calibration strategy combining a parameter transfer framework based on catchment similarities with a holistic calibration against hydrological signatures is presented to obtain reliable simulations at all relevant locations within a catchment. The approach is demonstrated for three African river catchments: the Tana, the Upper Niger and the Semliki catchments.A rainfall-runoff model based on Budyko’s concept of limits with up to 11 calibration parameters and a daily simulation time step is used, coupled with a Muskingum routing scheme. Each river catchment is subdivided into so-called hydrological response units (HRU) based on climatic and physiographic characteristics. Multi-mission satellite remote sensing observations are used for the HRU classification: terrain slope derived from the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) and the publicly available European Space Agency (ESA) Climate Change Initiative (CCI) land cover map. Subcatchments within each HRU share the same parameters. The number of units is constrained by the number of in-situ stations available. The calibration strategy is a catchment-scale, multi-objective approach.The method improved the overall model performance compared to a simpler, nearest-neighbor regionalization method. In particular, spatial patterns of the hydrological response are more reasonable and performance is improved at validation stations, highlighting the importance of appropriate parameter regionalization within nested catchments. With this method, a wider range of currently available remote sensing data (elevation, precipitation, land cover, etc.) can be exploited in hydrological model development and calibration.

Processes shaping the spatial pattern and seasonality of the surface air temperature response to anthropogenic forcing

In the period 1960–2010, the land surface air temperature (SAT) warmed more rapidly over some regions relative to the global mean. Using a set of time-slice experiments, we highlight how different physical processes shape the regional pattern of SAT warming. The results indicate an essential role of anthropogenic forcing in regional SAT changes from the 1970s to 2000s, and show that both surface–atmosphere interactions and large-scale atmospheric circulation changes can shape regional responses to forcing. Single forcing experiments show that an increase in greenhouse gases can lead to regional changes in land surface warming in winter (DJF) due to snow-albedo feedbacks, and in summer (JJA) due to soil-moisture and cloud feedbacks. Changes in anthropogenic aerosol and precursor (AA) emissions induce large spatial variations in SAT, characterized by warming over western Europe, Eurasia, and Alaska. In western Europe, SAT warming is stronger in JJA than in DJF due to substantial increases in clear sky shortwave radiation over Europe, associated with decreases in local AA emissions since the 1980s. In Alaska, the amplified SAT warming in DJF is due to increased downward longwave radiation, which is related to increased water vapor and cloud cover. In this case, although the model was able to capture the regional pattern of SAT change, and the associated local processes, it did not simulate all processes and anomalies correctly. For the Alaskan warming, the model is seen to achieve the correct regional response in the context of a wider North Pacific anomaly that is not consistent with observations. This demonstrates the importance of model evaluation that goes beyond the target variable in detection and attribution studies.

A Computational Mechanism for Seeing Dynamic Deformation.

Human observers perceptually discriminate the dynamic deformation of materials in the real world. However, the psychophysical and neural mechanisms responsible for the perception of dynamic deformation have not been fully elucidated. By using a deforming bar as the stimulus, we showed that the spatial frequency of deformation was a critical determinant of deformation perception. Simulating the response of direction-selective units (i.e., MT pattern motion cells) to stimuli, we found that the perception of dynamic deformation was well explained by assuming a higher-order mechanism monitoring the spatial pattern of direction responses. Our model with the higher-order mechanism also successfully explained the appearance of a visual illusion wherein a static bar apparently deforms against a tilted drifting grating. In particular, it was the lower spatial frequencies in this pattern that strongly contributed to the deformation perception. Finally, by manipulating the luminance of the static bar, we observed that the mechanism for the illusory deformation was more sensitive to luminance than contrast cues.

The spatial response pattern of coseismic landslides induced by the 2008 Wenchuan earthquake to the surface deformation and Coulomb stress change revealed from InSAR observations

The 2008 Mw 7.9 Wenchuan earthquake triggered plenty of coseismic giant landslides, which resulted in almost one third of total fatalities and economic losses during the event. Previous studies investigated the spatial relations between landslide distribution and topographic and seismic factors such as elevation, slope aspect, distance from rupture trace and seismic intensity. However, few studies are performed exploring the effects of coseismic surface deformation and Coulomb stress change on triggering landslides due to lack of adequate deformation observation data and stress calculation model for slope failure. In this study, we develop an envelope method to map an entire coseismic deformation field in both near- and far-field areas of seismic faults through the data fusion from InSAR and pixel offset-tracking (POT) techniques. The change in static Coulomb stress (SCS) acting on coseismic landsliding surface caused by the event is determined using the faulting model derived from the joint inversion of InSAR and GPS data, and also with the use of the elastic half-space dislocation theory and the generalized Hook’s law. The analysis suggests the spatial response pattern of seismic landslides to the coseismic ground motion and stress change, especially in the vicinity of fault rupture trace. The landslide density dramatically rises with the stress increase within the range from Yingxiu to Beichuan areas along the major surface rupture. Moving further and eastward along the fault strike, most of large landslides are triggered as the zone of positive SCS change narrows. Moreover, the high-magnitude surface displacements are possibly responsible for the giant landsliding events in the easternmost section. From the analysis of the stress transfer, the occurrence of landslides in the study area is largely controlled by the Yingxiu-Beichuan fault with overwhelming rupture length and fault slip, yet the Pengguan fault indeed shows dominance in the area between the two faults. The results show that coseismic surface deformation (derived from InSAR data in this study) and static Coulomb stress change can serve as two significant controlling factors on seismic landslide distribution and that the stress factor seems more significant in the vicinity of surface rupture.

Spatial variation patterns of plant herbaceous community response to warming along latitudinal and altitudinal gradients in mountainous forests of the Loess Plateau, China

As climate warming is more obvious in high mountains, the spatial patterns of mountainous vegetation responding to climate warming are expected to become a new aspect in forest ecosystem research. However, we do not know how spatial patterns of vegetation in mountainous regions respond to climate warming, and we also do not know what will happen to the patterns when rainfall occurs. Here, we conducted warming experiments to explore the variation pattern of the response of the herbaceous community to experimental warming along latitudinal and altitudinal gradients in mountainous forests of the Loess Plateau. In low and high warming amplitudes, air temperature increased by a maximum of 0.86 °C and 2.83 °C, respectively; the response of air temperature was obviously affected by elevation, whereas air humidity was not sensitive to warming. When rainfall occurred, warming produced decreases in soil temperature by a maximum of 0.56 °C and 0.61 °C in low and high warming amplitudes, respectively; soil temperature was evidently affected by latitude; and soil moisture was insensitive to warming. That was, the corresponding responsiveness of air and soil temperature was dependent on elevation and latitude, and a sudden increase in soil moisture caused by rainfall influenced the effects of warming on soil temperature. Warming also increased plant height and coverage, but plant density and frequency did not respond to warming, thus leading to insignificant changes for importance values of grass, sedge, and forb. Moreover, plant richness and Simpson indices increased in low-amplitude warming and decreased in high-amplitude warming, but the Pielou index was insensitive to warming. The responsiveness of these plant factors decreased with latitude and increased with elevation. Correlations tended to be enhanced by warming among vegetation, temperature (air temperature and soil temperature), and moisture (air humidity and soil moisture); the correlation among vegetation, air humidity, and soil moisture increased relatively rapidly in response to warming. With soil moisture increasing, plant height diminished and species diversity enlarged in warming, demonstrating that moisture increase caused by rainfall modified warming effects on vegetation. In regions with water deficits as the Loess Plateau, warming reinforced the relationship of vegetation with water and thus promoted its dependence on water. Warming could be controlled in a certain range and thus exerted positive effects on vegetation and facilitated plant community development. In regions where water is the limiting factor, warming effects were largely influenced by rainfall; the moisture increment induced by rainfall might weaken warming effects on soil and its correlation with vegetation.

黄土高原林下草地对模拟增温的短期响应

气候变暖在高海拔山地更为明显，山地植被对气候变暖响应的空间格局将成为山地研究新的热点。在黄土高原东部沿纬度梯度选择北段管涔山、中段关帝山和南段五鹿山，分别划分高、中、低3个海拔梯度，每一梯度用开顶式生长室设置对照（CK）、低度增温（LW）、高度增温（HW）3种模拟增温样地，于增温1年后植被生长季调查山地林下草本群落的生长特征及水热因子，探究黄土高原林下草地对气候变暖的短期响应及其随纬度、海拔的变化格局。结果表明：在LW和HW处理下，（1）空气温度增加0.47℃和1.00℃，空气湿度增加1.37%和1.94%，其中空气温度增幅随海拔增加显著增大（P=0.012）；（2）土壤水分减小0.32%和0.64%，土壤温度减小0.07℃和增加0.06℃，其中土壤温度增幅随纬度增加显著减小（P=0.003）；（3）植物密度增加41.27株/m²和78.53株/m²，植物高度增加0.04 m和0.03 m，植物频度增加5.47%和3.47%，而植物盖度显著增加5.32%和0.88%（P=0.042）；（4）植被与温度关系的相关系数绝对值增加31.49%和56.82%，与水分关系的相关系数绝对值增加38.67%和62.89%。因此，山地温度对增温响应更大，且空气温度具正向海拔依赖性，土壤温度具负向纬度依赖性；增温加强植被与水分的关系，促进植物对水的依赖性，进而显著影响植物盖度。然而，增温的短期效应易受到降雨条件的影响，使结果出现误差，故在类似的研究中建议加强试验的时间尺度。;Climate warming is more obvious in high-altitude mountains, and as a result, investigating the spatial patterns of mountainous vegetation responses to climate warming is becoming a new hot spot of mountain research. The Luliang Mountain Range lies on the east side of the Loess Plateau in central China and is characterized by an extremely fragile environment due to the lack of precipitation. Based on latitudinal gradients from north to south in the Luliang Mountain Range, the affiliated Guancen Mountain in its northern section, Guandi Mountain in its central section, and Wulu Mountain in its southern section were selected as study area. Each of these mountains was divided into three gradients: high altitude, medium altitude, and low altitude. The corresponding elevations for the high, medium, and low altitudes were 2571.3 m, 2395.0 m, and 2222.4 m for Guancen Mountain, 2179.1 m, 2000.7 m, and 1899.7 m for Guandi Mountain, and 1602.0 m, 1458.6 m, and 1318.0 m for Wulu Mountain, respectively. Three experimental plots heated by open-top chambers (OTCs) were placed within each altitudinal gradient. Treatments were implemented using completely randomized block design and including control (CK), low temperature increase (LW), and high temperature increase (HW). During the growing season in 2017, the growth characteristics and hydrothermal factors of the herbaceous communities in mountainous forests were surveyed in order to explore the responses of herbaceous communities to climate warming as well as the spatial pattern changes of these responses with latitudinal and altitudinal gradients. The results revealed the following under the LW and HW treatments: (1) air temperature increased by 0.47℃ and 1.00℃, respectively. The atmospheric relative humidity increased by 1.37% and 1.94%, respectively. The increasing amplitude of air temperature grew significantly with altitude (P = 0.012). (2) Corresponding soil moisture decreased by 0.32% and 0.64%, respectively. The soil temperature decreased by 0.07℃ and increased by 0.06℃. The increasing amplitude of soil temperature diminished significantly with latitude (P = 0.003). (3) The respective vegetation density increased by 41.27 plants/m² and 78.53 plants/m², but vegetation height increased by 0.04 m and 0.03 m. The vegetation frequency increased by 5.47% and 3.47%, while vegetation coverage significantly increased by 5.32% and 0.88% (P = 0.042). (4) The relationships among vegetation indices, temperature factors, and moisture factors using RDA ordination analysis indicated that the absolute value of the correlation coefficient between vegetation and temperature increased by 31.49% and 56.82%, as well as that between vegetation and moisture correspondingly increased by 38.67% and 62.89%, respectively. Therefore, in the Luliang Mountain Range, temperature factors were more responsive to warming, with air temperature being positively correlated with altitude and soil temperature being negatively correlated with latitude. However, the warming effects from the OTCs strengthened the relationship between vegetation and moisture, which promoted the dependence of plants on moisture, thereby significantly affecting vegetation coverage. Warming should be controlled in terms of amplitude, which will then have positive effects on vegetation. When precipitation occurred during the experiment, however, the associated moisture enhancement could weaken the warming effects on the soil. Thus the soil temperature decreased during warming treatments, indicating that precipitation had a greater influence on warming effects in regions where precipitation dominated the environmental factors. Therefore, the effects of short-term warming were affected largely by rainfall, which introduced errors into the results. We strongly suggest that the experimental duration should be prolonged in similar studies on warming effects in order to reduce these errors.

Perturbation analysis of a multi-morphogen Turing reaction-diffusion stripe patterning system reveals key regulatory interactions.

ABSTRACTPeriodic patterning is widespread in development and can be modelled by reaction-diffusion (RD) processes. However, minimal two-component RD descriptions are vastly simpler than the multi-molecular events that actually occur and are often hard to relate to real interactions measured experimentally. Addressing these issues, we investigated the periodic striped patterning of the rugae (transverse ridges) in the mammalian oral palate, focusing on multiple previously implicated pathways: FGF, Hh, Wnt and BMP. For each, we experimentally identified spatial patterns of activity and distinct responses of the system to inhibition. Through numerical and analytical approaches, we were able to constrain substantially the number of network structures consistent with the data. Determination of the dynamics of pattern appearance further revealed its initiation by ‘activators’ FGF and Wnt, and ‘inhibitor’ Hh, whereas BMP and mesenchyme-specific-FGF signalling were incorporated once stripes were formed. This further limited the number of possible networks. Experimental constraint thus limited the number of possible minimal networks to 154, just 0.004% of the number of possible diffusion-driven instability networks. Together, these studies articulate the principles of multi-morphogen RD patterning and demonstrate the utility of perturbation analysis for constraining RD systems.This article has an associated ‘The people behind the papers’ interview.

Radiative effects of daily cycle of cloud frequency in past and future climates

The daily cloud cycle (DCC) and its response to global warming are critical to the Earth's energy budget, but their radiative effects have not been systematically quantified. Toward this goal, here we analyze the radiation at the top of the atmosphere and propose a measure of the DCC radiative effect (DCCRE) as the difference between the total radiative fluxes with the full cloud cycle and its uniformly distributed cloud counterpart. We apply it to the cloud fraction from four climate models that participated in the second phase of the Cloud Feedback Model Inter-comparison Project. The results allow us to objectively compare inter-model differences in the daily cycle of cloud fraction and their influences on the global energy balance. In particular, the spatial patterns of the DCC response to global warming obtained in our analysis suggest possible impacts on large-scale circulation. Such a framework can be used for conducting a more systematic evaluation of the DCC in climate models and observations with the goal to reduce uncertainty in climate projections.

Hemodynamic responses are abnormal in isolated cervical dystonia.

Neuroimaging studies using functional magnetic resonance imaging (fMRI), which measures brain activity by detecting the changes in blood oxygenation levels, are advancing our understanding of the pathophysiology of dystonia. Neurobiological disturbances in dystonia, however, may affect neurovascular coupling and impact the interpretability of fMRI studies. We evaluated here whether the hemodynamic response patterns during a behaviorally matched motor task are altered in isolated cervical dystonia (CD). Twenty-five CD patients and 25 healthy controls (HCs) underwent fMRI scanning during a paced finger tapping task (nondystonic task in patients). Imaging data were analyzed using a constrained principal component analysis-a statistical method that combines regression analysis and principal component analysis and enables the extraction of task-related functional networks and determination of the spatial and temporal hemodynamic response patterns associated with the task performance. Data from three patients and two controls were removed due to excessive movement. No significant differences in demographics or motor performance were observed. Three task-associated functional brain networks were identified. During task performance, reduced hemodynamic responses were seen in a sensorimotor network and in a network that included key nodes of the default mode, executive control and visual networks. During rest, reductions in hemodynamic responses were seen in the cognitive/visual network. Lower hemodynamic responses within the primary sensorimotor network in patients were correlated with the increased dystonia severity. Pathophysiological disturbances in isolated CD, such as alterations in inhibitory signaling and dopaminergic neurotransmission, may impact neurovascular coupling. Not accounting for hemodynamic response differences in fMRI studies of dystonia could lead to inaccurate results and interpretations.

The effect of fire on terrestrial amphipods (Crustacea: Amphipoda) in a natural grassland community

Fire is known to cause severe and protracted reductions in some invertebrate communities. Amphipods are prone to desiccation and, therefore, litter removal through fire could be expected to have a significant adverse impact on their populations. We aimed to determine the temporal and spatial response patterns in density of amphipods following seasonal fires in a natural grassland site in southern South Island, New Zealand. Fires lit for management purposes in spring are generally cooler and considered less detrimental to the ecosystem than those occurring in hot dry summer conditions. Annual quantitative sampling was used to measure amphipod density in tussock grassland communities before and after single fire treatments were carried out in either spring or summer. Three samples were taken annually before each of the experimental fires, and for 12 years post-treatment. In general, amphipod populations took 7–9 years after treatment to recover to pre-burn densities although densities in spring burnt plots recovered more slowly. Eleven years post-burn, the spatial distribution of amphipods in relation to microhabitat was also examined. Two amphipod species were present, and they were distributed differently in tussock and inter-tussock vegetation and responded differently to fire but not to fire season. A protracted period of recovery from fire for an important member of the detritivore community is likely to have negative impacts on nutrient cycling, and therefore on primary production in grassland systems. The implication for land managers is to avoid burning in spring if soil conditions are relatively dry.

Flexible, multichannel cuff electrode for selective electrical stimulation of the mouse trigeminal nerve

The trigeminal nerve (cranial nerve V), along with other cranial nerves, has in recent years become a popular target for bioelectric medicine due to its direct access to neuromodulatory centers. Trigeminal nerve stimulation is currently being evaluated as an adjunctive treatment for various neurodegenerative and neuropsychiatric diseases despite the mechanism of action being in question. In this work, we describe the development and validation of a novel neural interface for the infraorbital branch of the trigeminal nerve utilizing a thin film (TF) nerve cuff containing multiple electrode sites allowing for more selective stimulation of the nerve. We characterized the properties of the device using electrochemical impedance spectroscopy, cyclic voltammetry, voltage excursions, and in vivo testing. Electrochemical measurements demonstrate that the platinum-based electrodes possess a capacitive charge carrying mechanism suitable for stimulation of biological tissue with a safe charge injection limit of 73.13 μC/cm2. In vivo stimulation experiments show that the TF cuff can reliably stimulate nerve targets eliciting cortical responses similar to a silicone cuff electrode. Furthermore, selecting different pairs of stimulation electrodes on the TF cuff modulated the magnitude and/or spatial pattern of cortical responses suggesting that the device may be able to selectively stimulate different parts of the nerve. These results suggest that the TF cuff is a viable neural interface for stimulation of the infraorbital branch of the trigeminal nerve that enables future research examining the therapeutic mechanisms of trigeminal nerve stimulation.

Emergency calls during the 2013 southern Ontario ice storm: case study of Vaughan

PurposeResponding to emergency incidents by emergency response organizations such as fire, ambulance and police during large disaster and emergency events is very important. The purpose of this paper is to provide some insights into response patterns during the 2013 ice storm in the city of Vaughan, Ontario, Canada, using temporal and spatial analyses.Design/methodology/approachThe City of Vaughan Fire and Rescue Service data set containing all responses to fire and other emergency incidents from January 1, 2009 to December 31, 2016 was used. The 2013 Southern Ontario ice storm occurred from December 20, 2013 to January 1, 2014, and, for this study, December 20–31 is considered the “study period.” Temporal, spatial and spatiotemporal analyses of responses during the study period are carried out and are compared with the same period in other years (2009–2012 and 2014–2016).FindingsThe findings show that temporal patterns of response attributes changed significantly during the 2013 ice storm. Similarly, the spatial pattern of responses during the 2013 ice storm showed some major differences with other years. The spatiotemporal analyses also demonstrate significant variations in responses in the city during different hours of the day in the ice storm days.Originality/valueThis study is the first study to examine the spatiotemporal patterns of responses made by a fire department during the 2013 ice storm in Canada. It provides some insights into the differences between response volumes, temporal and spatial distributions during large emergency events (e.g. ice storm) and normal situations. The results will help in mitigating the number of responses in the future through public education and technological changes. Moreover, the results will provide fire departments with information that could help them prepare for such events by possible reallocation of resources.

Regulation of atmospheric circulation controlling the tropical Pacific precipitation change in response to CO2 increases

The spatial pattern of precipitation responses to CO2 concentration increases significantly influences global weather and climate variability by altering the location of tropical heating in a warmer climate. In this study, we analyze the Coupled Model Intercomparison Project Phase 5 (CMIP5) climate model projections of tropical Pacific rainfall response to quadrupled increase of CO2. We found that the precipitation changes to the CO2 concentration increase cannot be interpreted by a weakening or strengthening of large-scale east–west coupling across the tropical Pacific basin, i.e., Walker circulation. By calculating the water vapor transport, we suggest instead that different responses of the Walker and Hadley circulations to the increasing CO2 concentration shape the details of the spatial pattern of precipitation in the tropical Pacific. Therefore, more regionally perturbed circulations over the tropical Pacific, which is influenced by the mean state change in the tropical Pacific and the enhanced precipitation outside the tropical Pacific, lead to greater increases in precipitation in the western equatorial Pacific as compared to the eastern tropical Pacific in a warmer climate.