scholarly journals Analysis of her1 and her7 Mutants Reveals a Spatio Temporal Separation of the Somite Clock Module

PLoS ONE ◽  
2012 ◽  
Vol 7 (6) ◽  
pp. e39073 ◽  
Author(s):  
Suma Choorapoikayil ◽  
Bernd Willems ◽  
Peter Ströhle ◽  
Martin Gajewski
Keyword(s):  
Temporal Separation ◽  
Spatio Temporal ◽  
Clock Module

Effect of background clutter on neural discrimination in the bat auditory midbrain

2021 ◽  
Author(s):  
Kathryne M Allen ◽  
Angeles Salles ◽  
Sanwook Park ◽  
Mounya Elhilali ◽  
Cynthia F. Moss
Keyword(s):  
Acoustic Scattering ◽  
Object Discrimination ◽  
Complex Environments ◽  
Acoustic Features ◽  
Temporal Separation ◽  
Complex Sounds ◽  
Electrophysiological Recordings ◽  
Background Clutter ◽  
Spatio Temporal ◽  
Neural Underpinnings

The discrimination of complex sounds is a fundamental function of the auditory system. This operation must be robust in the presence of noise and acoustic clutter. Echolocating bats are auditory specialists that discriminate sonar objects in acoustically complex environments. Bats produce brief signals, interrupted by periods of silence, rendering echo snapshots of sonar objects. Sonar object discrimination requires that bats process spatially and temporally overlapping echoes to make split-second decisions. The mechanisms that enable this discrimination are not well understood, particularly in complex environments. We explored the neural underpinnings of sonar object discrimination in the presence of acoustic scattering caused by physical clutter. We performed electrophysiological recordings in the inferior colliculus of awake big brown bats, to broadcasts of pre-recorded echoes from physical objects. We acquired single unit responses to echoes and discovered a sub-population of IC neurons that encode acoustic features that can be used to discriminate between sonar objects. We further investigated the effects of environmental clutter on this population's encoding of acoustic features. We discovered that the effect of background clutter on sonar object discrimination is highly variable and depends on object properties and target-clutter spatio-temporal separation. In many conditions, clutter impaired discrimination of sonar objects. However, in some instances clutter enhanced acoustic features of echo returns, enabling higher levels of discrimination. This finding suggests that environmental clutter may augment acoustic cues used for sonar target discrimination and provides further evidence in a growing body of literature that noise is not universally detrimental to sensory encoding.

scholarly journals Cortical suppressive waves shape the representation of long-range apparent motion

2018 ◽  
Author(s):  
S Chemla ◽  
A Reynaud ◽  
M di Volo ◽  
Y Zerlaut ◽  
L Perrinet ◽  
...  
Keyword(s):  
Apparent Motion ◽  
Gain Control ◽  
Motion Path ◽  
Object Identity ◽  
Temporal Separation ◽  
Cortical Dynamics ◽  
Population Responses ◽  
Temporal Succession ◽  
Spatio Temporal ◽  
The Brain

SummaryHow does the brain link visual stimuli across space and time? Visual illusions provide an experimental paradigm to study these processes. When two stationary dots are flashed in close spatial and temporal succession, human observers experience a percept of motion. Large spatio-temporal separation challenges the visual system to keep track of object identity along the apparent motion path. Here, we utilize voltage-sensitive dye imaging in primary visual cortex (V1) of the awake monkey to investigate whether intra-cortical connections within V1 can shape cortical dynamics to represent the illusory motion. We find that the arrival of the second stimulus in V1 creates a suppressive wave traveling toward the retinotopic representation of the first. Computational approaches show that this suppressive wave can be explained by recurrent gain control fed by the intra-cortical network and contributes to precisely encode the expected motion velocity. We suggest that non-linear intra-cortical dynamics preformat population responses in V1 for optimal read-out by downstream areas.

scholarly journals Salts in the base soils as a factor forming their corrosion activity, subsidence and compressibility

2020 ◽  
Vol 78 (4) ◽  
pp. 254-260
Keyword(s):  
Clay Soil ◽  
Design Stage ◽  
Design Parameters ◽  
Silty Clay ◽  
Reliable Operation ◽  
Temporal Separation ◽  
Salt Component ◽  
Spatio Temporal ◽  
Silty Clay Soil ◽  
Standard Service

Saline silty clay soil (SSCS) is the stochastic spatio-temporal separation of a common territory, which changes under conditions of natural and man-made impact on the salt component of soil. The research methodology of SSCS is proposed here. The design parameters determined by the proposed methodology allow to take into account the entire spectrum of changes in the properties of the SSCS in the base for the standard service life of the designed facility at the design stage, and, therefore, to select reliable geotechnology for construction of the designed facility, thereby ensuring its reliable operation.

scholarly journals Observing spatio-temporal clustering and separation using interevent distributions of regional earthquakes

2014 ◽  
Vol 21 (4) ◽  
pp. 735-744 ◽  
Author(s):  
R. C. Batac ◽  
H. Kantz
Keyword(s):  
Short Distance ◽  
Temporal Organization ◽  
Long Distance ◽  
Temporal Separation ◽  
Temporal Clustering ◽  
Independent Events ◽  
Characteristic Value ◽  
Spatio Temporal ◽  
Catalogue Completeness ◽  
T Values

Abstract. Past studies that attempted to quantify the spatio-temporal organization of seismicity have defined the conditions by which an event and those that follow it can be related in space and/or time. In this work, we use the simplest measures of spatio-temporal separation: the interevent distances R and interevent times T between pairs of successive events. We observe that after a characteristic value R*, the distributions of R begin to follow that of a randomly shuffled sequence, suggesting that events separated by R > R* are more likely to be uncorrelated events generated independent of one another. Interestingly, the conditional T distributions for short-distance (long-distance) events, R ≤ R* (R > R*), peak at correspondingly short (long) T values, signifying the spatio-temporal clustering (separation) of correlated (independent) events. By considering different threshold magnitudes within a range that ensures substantial catalogue completeness, invariant quantities related to the spatial and temporal spacing of correlated events and the rate of generation of independent events emerge naturally.

scholarly journals A method for random uncertainties validation and probing the natural variability with application to TROPOMI/Sentinel5P total ozone measurements

2020 ◽  
Author(s):  
Viktoria F. Sofieva ◽  
Hei Shing Lee ◽  
Johanna Tamminen ◽  
Christophe Lerot ◽  
Fabian Romahn ◽  
...  
Keyword(s):  
Structure Function ◽  
Total Ozone ◽  
Random Noise ◽  
Separation Distance ◽  
Natural Variability ◽  
Measured Parameter ◽  
Inversion Algorithm ◽  
Temporal Separation ◽  
Spatio Temporal ◽  
Random Uncertainties

Abstract. In this paper, we discuss the method for validation of random uncertainties in the remote sensing measurements based on evaluation of the structure function, i.e., root-mean-square differences as a function of increasing spatio-temporal separation of the measurements. The limit at the zero mismatch provides the experimental estimate of random noise in the data. At the same time, this method allows probing the natural variability of the measured parameter. As an illustration, we applied this method to the clear-sky total ozone measurements by TROPOMI/Sentinel-5P. We found that the random uncertainties reported by the TROPOMI inversion algorithm, which are in the range 1–2 DU, agree well with the experimental uncertainty estimated by the structure function. Our analysis of the structure function has shown the expected results on total ozone variability: it is significantly smaller in the tropics compared to mid-latitudes. At mid-latitudes, ozone variability is much larger in winter than in summer. The ozone structure function is anisotropic (being larger in latitudinal direction) at horizontal scales larger than 10–20 km. The structure function rapidly grows with the separation distance. At mid-latitudes in winter, the ozone values can differ by 5 % at separations 300–500 km. The discussed method is a powerful tool in experimental estimates of the random noise in data and studies of natural variability and it can be used in various applications.

Morality from Compassion

2021 ◽  
Author(s):  
Ingmar Persson
Keyword(s):  
Personal Identity ◽  
Moral Virtue ◽  
Arthur Schopenhauer ◽  
Temporal Separation ◽  
Positive Form ◽  
Philosophical Ethics ◽  
Positive Feelings ◽  
Spatio Temporal ◽  
Negative Feelings ◽  
Negative Form

According to Arthur Schopenhauer, compassion is the basis of morality. He sees concern for justice as a negative form of compassion, directed at not harming anyone, as opposed to the more far-reaching, positive form of benefiting. He thinks a higher degree of compassion involves realizing that the spatio-temporal separation of individuals is illusory and that in reality they are all identical. Such compassion is impartial and all-encompassing. Compassion is suited to be the centre of morality because its object are negative feelings, and only these are real. Contrary to these Schopenhauerian claims, it is here argued that compassion must be supplemented with attitudes like sympathy and benevolence because positive feelings exist alongside negative feelings; that a concern for justice, though morally essential, is independent of these attitudes which are based on empathy; that these attitudes involve not identifying oneself with others, but taking personal identity as insignificant in empathically imagining how others feel. Schopenhauer is, however, right that, though these attitudes are spontaneously partial, this can be corrected. His morality is also interesting in raising the question rarely discussed in philosophical ethics of how moral virtue relates to ascetic self-renunciation. Both of these ideals are highly demanding, but the book ends by arguing that this is no objection to their validity.

Negative Priming Persists in the Absence of Response-Retrieval

2013 ◽  
Vol 60 (1) ◽  
pp. 12-21 ◽  
Author(s):  
Matthias Ihrke ◽  
Jörg Behrendt ◽  
Hecke Schrobsdorff ◽  
Ingmar Visser ◽  
Marcus Hasselhorn
Keyword(s):  
Negative Priming ◽  
Response Selection ◽  
Selection Process ◽  
Target Selection ◽  
Specific Interaction ◽  
Temporal Separation ◽  
Positive Priming ◽  
Visual Identity ◽  
Spatio Temporal ◽  
Main Effects

The hypothesis that retrieval of the prime response is responsible for the negative priming (NP) effect has gained popularity in recent studies of visual identity NP. In the current study we report an experiment in which we aimed to remove the response from the prime memory trace by means of spatio-temporal separation. Compared to an identical experiment without this separation ( Ihrke et al., 2011 ), we find that the response-retrieval-specific interaction is absent indicating that the separation was successful in preventing response-retrieval. Still, both negative and positive priming are present as main effects which show that processes other than response-retrieval can produce NP. In addition, based on recordings of the eye-movements during task processing, we localize the NP effect in a target-selection process while positive priming manifests in facilitated response-selection. Our results are in line with a multiple-route view of NP.

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