scholarly journals Coriolis and centrifugal forces drive haltere deformations and influence spike timing

2019 ◽  
Vol 16 (153) ◽  
pp. 20190035 ◽  
Author(s):  
T. L. Mohren ◽  
T. L. Daniel ◽  
A. L. Eberle ◽  
P. G. Reinhall ◽  
J. L. Fox
Keyword(s):  
Mass Distribution ◽  
Neural Activity ◽  
Three Dimensional ◽  
Temporal Patterns ◽  
Spike Timing ◽  
Point Mass ◽  
Centrifugal Forces ◽  
Spatial And Temporal Patterns ◽  
Spatio Temporal ◽  
Three Dimensional Finite Element

The halteres of flies are mechanosensory organs that serve a crucial role in the control of agile flight, providing sensory input for rapid course corrections to perturbations. Derived from hind wings, halteres are actively flapped and are thus subject to a variety of inertial forces as the fly undergoes complex flight trajectories. Previous analyses of halteres modelled them as a point mass, showing that Coriolis forces lead to subtle deflections orthogonal to the plane of flapping. By design, these models could not consider the effects of force gradients associated with a mass distribution, nor could they reveal three-dimensional spatio-temporal patterns of strain that result from those forces. In addition, diversity in the geometry of halteres, such as shape and asymmetries, could not be simply modelled with a point mass on a massless rod. To study the effects of mass distributions and asymmetries, we examine the haltere subject to both flapping and body rotations using three-dimensional finite-element simulations. We focus on a set of simplified geometries, in which we vary the stalk and bulb shape. We find that haltere mass distribution gives rise to two unreported deformation modes: (i) halteres twist with a magnitude that strongly depends on stalk and bulb geometry and (ii) halteres with an asymmetric mass distribution experience out-of-plane bending due to centrifugal forces, independent of body rotation. Since local strains at the base of the haltere drive deformations of mechanosensory neurons, we combined measured neural encoding mechanisms with our structural analyses to predict the spatial and temporal patterns of neural activity. This activity depends on both the flapping and rotation dynamics, and we show how the timing of neural activity is a viable mechanism for rotation-rate encoding. Our results provide new insights in haltere dynamics and show the viability for timing-based encoding of fly body rotations by halteres.

THE NEW RADIOCARBON DATASET FOR TRILITH MONUMENTS OF SOUTHEASTERN ARABIA

Radiocarbon ◽  
2020 ◽  
pp. 1-11
Author(s):  
R Garba ◽  
P Demján ◽  
I Svetlik ◽  
D Dreslerová
Keyword(s):  
Iron Age ◽  
Temporal Patterns ◽  
Temporal Analysis ◽  
Coastal Plains ◽  
Spatial And Temporal Patterns ◽  
Two Phase ◽  
Stone Monuments ◽  
South Central ◽  
Geographical Expansion ◽  
Spatio Temporal

ABSTRACT Triliths are megalithic monuments scattered across the coastal plains of southern and southeastern Arabia. They consist of aligned standing stones with a parallel row of large hearths and form a space, the meaning of which is undoubtedly significant but nonetheless still unknown. This paper presents a new radiocarbon (14C) dataset acquired during the two field seasons 2018–2019 of the TSMO (Trilith Stone Monuments of Oman) project which investigated the spatial and temporal patterns of the triliths. The excavation and sampling of trilith hearths across Oman yielded a dataset of 30 new 14C dates, extending the use of trilith monuments to as early as the Iron Age III period (600–300 BC). The earlier dates are linked to two-phase trilith sites in south-central Oman. The three 14C pairs collected from the two-phase trilith sites indicated gaps between the trilith construction phases from 35 to 475 years (2 σ). The preliminary spatio-temporal analysis shows the geographical expansion of populations using trilith monuments during the 5th to 1st century BC and a later pull back in the 1st and 2nd century AD. The new 14C dataset for trilith sites will help towards a better understanding of Iron Age communities in southeastern Arabia.

A real-time spike-timing classifier of spatio-temporal patterns

2018 ◽  
Vol 311 ◽  
pp. 183-196 ◽  
Author(s):  
Banafsheh Rekabdar ◽  
Luke Fraser ◽  
Monica Nicolescu ◽  
Mircea Nicolescu
Keyword(s):  
Real Time ◽  
Temporal Patterns ◽  
Spike Timing ◽  
Spatio Temporal

scholarly journals Microstimulation in the primary visual cortex: activity patterns and their relation to visual responses and evoked saccades

2020 ◽  
Author(s):  
R. Oz ◽  
H. Edelman-Klapper ◽  
S. Nivinsky-Margalit ◽  
H. Slovin
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Neural Activity ◽  
Visual Processing ◽  
Visual Stimuli ◽  
Temporal Patterns ◽  
Visual Responses ◽  
Population Activity ◽  
Spatio Temporal ◽  
Saccade Generation

AbstractIntra cortical microstimulation (ICMS) in the primary visual cortex (V1) can generate the visual perception of phosphenes and evoke saccades directed to the stimulated location in the retinotopic map. Although ICMS is widely used, little is known about the evoked spatio-temporal patterns of neural activity and their relation to neural responses evoked by visual stimuli or saccade generation. To investigate this, we combined ICMS with Voltage Sensitive Dye Imaging in V1 of behaving monkeys and measured neural activity at high spatial (meso-scale) and temporal resolution. Small visual stimuli and ICMS evoked population activity spreading over few mm that propagated to extrastriate areas. The population responses evoked by ICMS showed faster dynamics and different spatial propagation patterns. Neural activity was higher in trials w/saccades compared with trials w/o saccades. In conclusion, our results uncover the spatio-temporal patterns evoked by ICMS and their relation to visual processing and saccade generation.

Three-Dimensional Finite Element Model to Study Effect of RyR Calcium Channel, ER Leak and SERCA Pump on Calcium Distribution in Oocyte Cell

2018 ◽  
Vol 16 (01) ◽  
pp. 1850091 ◽  
Author(s):  
Parvaiz Ahmad Naik ◽  
Kamal Raj Pardasani
Keyword(s):  
Finite Element ◽  
Calcium Channel ◽  
Concentration Distribution ◽  
Calcium Concentration ◽  
Three Dimensional ◽  
Element Model ◽  
Dimensional Finite Element ◽  
Serca Pump ◽  
Spatio Temporal ◽  
Three Dimensional Finite Element

Calcium ions control many cellular processes by relaying signals in the form of their spatio-temporal distribution. Dynamics and patterns of calcium concentration such as repetitive waves, coherent oscillations or spatially localized elevations activate diverse physiological functions. Calcium is the most universal second messenger in cells and plays an important role in initiation, sustenance and termination of various activities in cells required for maintaining the structure and function of the cell. Calcium signal at fertilization is necessary for egg activation and exhibits specialized spatial and temporal dynamics. The specific calcium concentration distribution patterns in oocytes required for various activities like egg fertilization, maturation, etc. are not well understood. In this paper, a three-dimensional finite element model is proposed to study the spatio-temporal calcium distribution in oocytes. The parameters such as buffers, SERCA pump, ER Leak, ryanodine receptor (RyR) calcium channel, point source and line source of calcium are incorporated in the model. The appropriate initial and boundary conditions have been framed on the basis of the physical condition of the problem. A program is developed in MATLAB for simulation. The results have been used to study the effect of source geometry, RyR calcium channel, ER Leak, SERCA pump and buffers on cytosolic calcium concentration distribution in oocytes.

Three-dimensional model for analysis of spatial and temporal patterns of phytoplankton in Tucuruí reservoir, Pará, Brazil

2013 ◽  
Vol 253 ◽  
pp. 28-43 ◽  
Author(s):  
Ricardo Deus ◽  
David Brito ◽  
Isabella Ascione Kenov ◽  
Marcelo Lima ◽  
Vanessa Costa ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Temporal Patterns ◽  
Dimensional Model ◽  
Spatial And Temporal Patterns ◽  
Three Dimensional Model

scholarly journals Spatio-Temporal Analysis to Dynamically Map and Audit Urban Growth in Peri-Urban Areas

2021 ◽  
Vol 16 (5) ◽  
pp. 853-868
Author(s):  
Yasser ElSayed Fouda ◽  
Deena Mohamed ElKhazendar
Keyword(s):  
Quality Of Life ◽  
Urban Growth ◽  
Urban Areas ◽  
Temporal Patterns ◽  
Temporal Analysis ◽  
Spatial And Temporal Patterns ◽  
Model Framework ◽  
Measurement Framework ◽  
Spatio Temporal

Villages located today in the peri-urban area, are in continuous agglomeration. The lack of proper guidelines and monitoring systems to define, promote, regulate and manage the pattern of development in these areas, causes massive deteriorations to the environment and quality of life. In Egypt, very few states have a dedicated legal framework that addresses the need for planned development in the peri-urban areas. A Spatio-temporal model framework consisting of a set of geospatial indicators is required to regulate and direct the growth and development of these areas and prevent further spill across administrative boundaries. This article responds to the lack of a geo-spatial quantifiable criterion as a key to detect, analyze, and better govern spatial and temporal patterns of urban growth in peri-urban areas, where the results are to be represented dynamically in forms of spatial patterns evolving in time. The research aims to develop a process-wise, contextual mapping of peri-urban dynamics using GIS to detect and analyze spatial and temporal patterns of urban growth. It has been applied to one of the peri-urban areas in Egypt, in Meet Assas Village, chosen as a case study. Miscellaneous primary and secondary data sources together with the methods used for monitoring: UN Criteria (Goal 11) targets, thematic headlines, village’s problems and geo-spatial indicators were the main constitutions of the model frame work. The results show that the village is characterized by a dispersed pattern of development with the absence of basic infrastructure and services. Besides that, the study reveals, through temporal patterns, that the future and unplanned growth will continue to intensify; posing numerous threats on the environment and the quality of life. A harmonized standardized measurement framework for planning, development, and management is crucial rather than demolishing these areas.

scholarly journals Spatial and temporal patterns of human Puumala virus (PUUV) infections in Germany

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4255 ◽  
Author(s):  
Sarah Cunze ◽  
Judith Kochmann ◽  
Thomas Kuhn ◽  
Raphael Frank ◽  
Dorian D. Dörge ◽  
...  
Keyword(s):  
Temporal Patterns ◽  
Climatic Conditions ◽  
Reservoir Host ◽  
Human Infection ◽  
Environmental Data ◽  
Myodes Glareolus ◽  
Puumala Virus ◽  
Spatial And Temporal Patterns ◽  
Bank Voles ◽  
Spatio Temporal

Background Worldwide, the number of recorded human hantavirus infections as well as the number of affected countries is on the rise. In Europe, most human hantavirus infections are caused by the Puumala virus (PUUV), with bank voles (Myodes glareolus) as reservoir hosts. Generally, infection outbreaks have been related to environmental conditions, particularly climatic conditions, food supply for the reservoir species and land use. However, although attempts have been made, the insufficient availability of environmental data is often hampering accurate temporal and spatially explicit models of human hantavirus infections. Methods In the present study, dynamics of human PUUV infections between 2001 and 2015 were explored using ArcGIS in order to identify spatio-temporal patterns. Results Percentage cover of forest area was identified as an important factor for the spatial pattern, whereas beech mast was found explaining temporal patterns of human PUUV infections in Germany. High numbers of infections were recorded in 2007, 2010 and 2012 and areas with highest records were located in Baden-Wuerttemberg (southwest Germany) and North Rhine-Westphalia (western Germany). Conclusion More reliable data on reservoir host distribution, pathogen verification as well as an increased awareness of physicians are some of the factors that should improve future human infection risk assessments in Germany.

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