scholarly journals Synaptic Interactions in Scorpion Peg Sensilla Appear to Maintain Chemosensory Neurons within Dynamic Firing Range

Insects ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 904
Author(s):  
Douglas D. Gaffin ◽  
Safra F. Shakir
Keyword(s):  
B Cells ◽  
Interspike Interval ◽  
Temporal Dynamics ◽  
Spike Trains ◽  
Chemosensory Neurons ◽  
A Cells ◽  
Firing Range ◽  
Electrophysiological Recordings ◽  
Synaptic Interactions

Scorpions have elaborate chemo-tactile organs called pectines on their ventral mesosoma. The teeth of the comb-like pectines support thousands of minute projections called peg sensilla (a.k.a. “pegs”), each containing approximately 10 chemosensory neurons. Males use pectines to detect pheromones released by females, and both sexes apparently use pectines to find prey and navigate to home retreats. Electrophysiological recordings from pegs of Paruroctonus utahensis reveal three spontaneously active cells (A1, A2, and B), which appear to interact synaptically. We made long-term extracellular recordings from the bases of peg sensilla and used a combination of conditional cross-interval and conditional interspike-interval analyses to assess the temporal dynamics of the A and B spike trains. Like previous studies, we found that A cells are inhibited by B cells for tens of milliseconds. However, after normalizing our records, we also found clear evidence that the A cells excite the B cells. This simple local circuit appears to maintain the A cells in a dynamic firing range and may have important implications for tracking pheromonal trails and sensing substrate chemistry for navigation.

Economic conditions and perceptions of immigrants as an economic threat in Europe: Temporal dynamics and mediating processes

2021 ◽  
pp. 002071522199352
Author(s):  
Boris Heizmann ◽  
Nora Huth
Keyword(s):  
Temporal Dynamics ◽  
European Social Survey ◽  
Primary Objective ◽  
Conflict Theory ◽  
Economic Conditions ◽  
Political Climate ◽  
Short Term ◽  
Economic Threat ◽  
Party Positions

This article addresses the extent to which economic downturns influence the perception of immigrants as an economic threat and through which channels this occurs. Our primary objective is an investigation of the specific mechanisms that connect economic conditions to the perception of immigrants as a threat. We therefore also contribute to theoretical discussions based on group threat and realistic group conflict theory by exposing the dominant source of competition relevant to these relationships. Furthermore, we investigate whether people react more sensitive to short-term economic dynamics within countries than to the long-term economic circumstances. Our database comprises all waves of the European Social Survey from 2002 to 2017. The macro-economic indicators we use include GDP per capita, unemployment, and national debt levels, covering the most salient economic dimensions. We furthermore control for the country’s migration situation and aggregate party positions toward cultural diversity. Our results show that the dynamic short-term developments of the economy and migration within countries are of greater relevance for perceived immigrant threat than the long-term situation. In contrast, the long-term political climate appears to be more important than short-term changes in the aggregate party positions. Further mediation analyses show that objective economic conditions influence anti-immigrant attitudes primarily through individual perceptions of the country’s economic performance and that unemployment rates are of primary importance.

scholarly journals Global soil moisture data derived through machine learning trained with in-situ measurements

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Sungmin O. ◽  
Rene Orth
Keyword(s):  
Machine Learning ◽  
Soil Moisture ◽  
Large Scale ◽  
Short Term Memory ◽  
Temporal Dynamics ◽  
Soil Moisture Data ◽  
Wide Range ◽  
Global Soil

AbstractWhile soil moisture information is essential for a wide range of hydrologic and climate applications, spatially-continuous soil moisture data is only available from satellite observations or model simulations. Here we present a global, long-term dataset of soil moisture derived through machine learning trained with in-situ measurements, SoMo.ml. We train a Long Short-Term Memory (LSTM) model to extrapolate daily soil moisture dynamics in space and in time, based on in-situ data collected from more than 1,000 stations across the globe. SoMo.ml provides multi-layer soil moisture data (0–10 cm, 10–30 cm, and 30–50 cm) at 0.25° spatial and daily temporal resolution over the period 2000–2019. The performance of the resulting dataset is evaluated through cross validation and inter-comparison with existing soil moisture datasets. SoMo.ml performs especially well in terms of temporal dynamics, making it particularly useful for applications requiring time-varying soil moisture, such as anomaly detection and memory analyses. SoMo.ml complements the existing suite of modelled and satellite-based datasets given its distinct derivation, to support large-scale hydrological, meteorological, and ecological analyses.

scholarly journals Acute symptoms of mild to moderate COVID-19 are highly heterogeneous across individuals and over time

2021 ◽  
Author(s):  
Thomas L Rodebaugh ◽  
Madelyn R Frumkin ◽  
Angela M Reiersen ◽  
Eric J Lenze ◽  
Michael S Avidan ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Survey Methods ◽  
Clinical Care ◽  
Clinical Deterioration ◽  
Symptom Profiles ◽  
Fluctuating Course ◽  
The Common ◽  
Symptom Changes ◽  
Over Time

Abstract Background The symptoms of COVID-19 appear to be heterogenous, and the typical course of these symptoms is unknown. Our objectives were to characterize the common trajectories of COVID-19 symptoms and assess how symptom course predicts other symptom changes as well as clinical deterioration. Methods 162 participants with acute COVID-19 responded to surveys up to 31 times for up to 17 days. Several statistical methods were used to characterize the temporal dynamics of these symptoms. Because nine participants showed clinical deterioration, we explored whether these participants showed any differences in symptom profiles. Results Trajectories varied greatly between individuals, with many having persistently severe symptoms or developing new symptoms several days after being diagnosed. A typical trajectory was for a symptom to improve at a decremental rate, with most symptoms still persisting to some degree at the end of the reporting period. The pattern of symptoms over time suggested a fluctuating course for many patients. Participants who showed clinical deterioration were more likely to present with higher reports of severity of cough and diarrhea. Conclusion The course of symptoms during the initial weeks of COVID-19 is highly heterogeneous and is neither predictable nor easily characterized using typical survey methods. This has implications for clinical care and early-treatment clinical trials. Additional research is needed to determine whether the decelerating improvement pattern seen in our data is related to the phenomenon of patients reporting long-term symptoms, and whether higher symptoms of diarrhea in early illness presages deterioration.

scholarly journals MEG signatures of long-term effects of agreement and disagreement with the majority

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Gorin ◽  
V. Klucharev ◽  
A. Ossadtchi ◽  
I. Zubarev ◽  
V. Moiseeva ◽  
...  
Keyword(s):  
Reinforcement Learning ◽  
Social Influence ◽  
Temporal Dynamics ◽  
Peer Group ◽  
Long Term Effects ◽  
Learning Mechanisms ◽  
Source Imaging ◽  
The Face ◽  
First Session

AbstractPeople often change their beliefs by succumbing to an opinion of others. Such changes are often referred to as effects of social influence. While some previous studies have focused on the reinforcement learning mechanisms of social influence or on its internalization, others have reported evidence of changes in sensory processing evoked by social influence of peer groups. In this study, we used magnetoencephalographic (MEG) source imaging to further investigate the long-term effects of agreement and disagreement with the peer group. The study was composed of two sessions. During the first session, participants rated the trustworthiness of faces and subsequently learned group rating of each face. In the first session, a neural marker of an immediate mismatch between individual and group opinions was found in the posterior cingulate cortex, an area involved in conflict-monitoring and reinforcement learning. To identify the neural correlates of the long-lasting effect of the group opinion, we analysed MEG activity while participants rated faces during the second session. We found MEG traces of past disagreement or agreement with the peers at the parietal cortices 230 ms after the face onset. The neural activity of the superior parietal lobule, intraparietal sulcus, and precuneus was significantly stronger when the participant’s rating had previously differed from the ratings of the peers. The early MEG correlates of disagreement with the majority were followed by activity in the orbitofrontal cortex 320 ms after the face onset. Altogether, the results reveal the temporal dynamics of the neural mechanism of long-term effects of disagreement with the peer group: early signatures of modified face processing were followed by later markers of long-term social influence on the valuation process at the ventromedial prefrontal cortex.

scholarly journals Long-Term Survival and Gradual Recovery of B Cells in Patients (Pts) with Refractory Large B Cell Lymphoma (LBCL) Treated with Axicabtagene Ciloleucel (Axi-Cel)

2021 ◽  
Vol 27 (3) ◽  
pp. S404-S405
Author(s):  
Caron A. Jacobson ◽  
Frederick L. Locke ◽  
Armin Ghobadi ◽  
David B. Miklos ◽  
Lazaros J. Lekakis ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Lymphoma ◽  
B Cell Lymphoma ◽  
Term Survival ◽  
Long Term Survival ◽  
Large B Cell Lymphoma ◽  
Large B Cell

scholarly journals Overexpression of Transcripts Coding for Renin-b but Not for Renin-a Reduce Oxidative Stress and Increase Cardiomyoblast Survival under Starvation Conditions

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1204
Author(s):  
Heike Wanka ◽  
Philipp Lutze ◽  
Alexander Albers ◽  
Janine Golchert ◽  
Doreen Staar ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
B Cells ◽  
Apoptotic Cell ◽  
Renin Angiotensin System ◽  
Glucose Deprivation ◽  
Protective Effects ◽  
Glucose Depletion ◽  
A Cells ◽  
Apoptosis And Necrosis

A stimulated renin-angiotensin system is known to promote oxidative stress, apoptosis, necrosis and fibrosis. Renin transcripts (renin-b; renin-c) encoding a cytosolic renin isoform have been discovered that may in contrast to the commonly known secretory renin (renin-a) exert protective effects Here, we analyzed the effect of renin-a and renin-b overexpression in H9c2 cardiomyoblasts on apoptosis and necrosis as well as on potential mechanisms involved in cell death processes. To mimic ischemic conditions, cells were exposed to glucose starvation, anoxia or combined oxygen–glucose deprivation (OGD) for 24 h. Under OGD, control cells exhibited markedly increased necrotic and apoptotic cell death accompanied by enhanced ROS accumulation, loss of mitochondrial membrane potential and decreased ATP levels. The effects of OGD on necrosis were exaggerated in renin-a cells, but markedly diminished in renin-b cells. However, with respect to apoptosis, the effects of OGD were almost completely abolished in renin-b cells but interestingly also moderately diminished in renin-a cells. Under glucose depletion we found opposing responses between renin-a and renin-b cells; while the rate of necrosis and apoptosis was aggravated in renin-a cells, it was attenuated in renin-b cells. Based on our results, strategies targeting the regulation of cytosolic renin-b as well as the identification of pathways involved in the protective effects of renin-b may be helpful to improve the treatment of ischemia-relevant diseases.

scholarly journals A Replication-Defective Gammaherpesvirus Efficiently Establishes Long-Term Latency in Macrophages but Not in B Cells In Vivo

2008 ◽  
Vol 82 (17) ◽  
pp. 8500-8508 ◽  
Author(s):  
Haiyan Li ◽  
Kazufumi Ikuta ◽  
John W. Sixbey ◽  
Scott A. Tibbetts
Keyword(s):  
B Cells ◽  
Viral Genome ◽  
Lytic Replication ◽  
Mutant Virus ◽  
Wild Type Virus ◽  
Type Virus ◽  
Wild Type ◽  
Virus Latency

ABSTRACT Murine gammaherpesvirus 68 (γHV68 or MHV68) is genetically related to the human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV), providing a useful system for in vivo studies of the virus-host relationship. To begin to address fundamental questions about the mechanisms of the establishment of gammaherpesvirus latency, we previously generated a replication-defective γHV68 lacking the expression of the single-stranded DNA binding protein encoded by orf6. In work presented here, we demonstrate that this mutant virus established a long-term infection in vivo that was molecularly identical to wild-type virus latency. Thus, despite the absence of an acute phase of lytic replication, the mutant virus established a chronic infection in which the viral genome (i) was maintained as an episome and (ii) expressed latency-associated, but not lytic replication-associated, genes. Macrophages purified from mice infected with the replication-defective virus harbored viral genome at a frequency that was nearly identical to that of wild-type γHV68; however, the frequency of B cells harboring viral genome was greatly reduced in the absence of lytic replication. Thus, this replication-defective gammaherpesvirus efficiently established in vivo infection in macrophages that was molecularly indistinguishable from wild-type virus latency. These data point to a critical role for lytic replication or reactivation in the establishment or maintenance of latent infection in B cells.

scholarly journals Increasing frequency of low summer precipitation synchronizes dynamics and compromises metapopulation stability in the Glanville fritillary butterfly

2015 ◽  
Vol 282 (1806) ◽  
pp. 20150173 ◽  
Author(s):  
Ayco J. M. Tack ◽  
Tommi Mononen ◽  
Ilkka Hanski
Keyword(s):  
Population Dynamics ◽  
Population Change ◽  
Temporal Dynamics ◽  
Summer Precipitation ◽  
Life History Stage ◽  
General Effect ◽  
Spatial Synchrony ◽  
Glanville Fritillary Butterfly ◽  
Spatio Temporal

Climate change is known to shift species' geographical ranges, phenologies and abundances, but less is known about other population dynamic consequences. Here, we analyse spatio-temporal dynamics of the Glanville fritillary butterfly ( Melitaea cinxia ) in a network of 4000 dry meadows during 21 years. The results demonstrate two strong, related patterns: the amplitude of year-to-year fluctuations in the size of the metapopulation as a whole has increased, though there is no long-term trend in average abundance; and there is a highly significant increase in the level of spatial synchrony in population dynamics. The increased synchrony cannot be explained by increasing within-year spatial correlation in precipitation, the key environmental driver of population change, or in per capita growth rate. On the other hand, the frequency of drought during a critical life-history stage (early larval instars) has increased over the years, which is sufficient to explain the increasing amplitude and the expanding spatial synchrony in metapopulation dynamics. Increased spatial synchrony has the general effect of reducing long-term metapopulation viability even if there is no change in average metapopulation size. This study demonstrates how temporal changes in weather conditions can lead to striking changes in spatio-temporal population dynamics.

scholarly journals Temporal dynamics of couples’ communication behaviors in conflict discussions: A longitudinal analysis

2018 ◽  
Vol 36 (9) ◽  
pp. 2937-2960 ◽  
Author(s):  
Lorena Leuchtmann ◽  
Anne Milek ◽  
Katharina Bernecker ◽  
Fridtjof W. Nussbeck ◽  
Sabine Backes ◽  
...  
Keyword(s):  
Relationship Satisfaction ◽  
Self Efficacy ◽  
Temporal Dynamics ◽  
Efficacy Beliefs ◽  
Self Report ◽  
Communication Behaviors ◽  
Positive Communication ◽  
Conflict Communication ◽  
Negative Communication

Negative and positive conflict communication predicts long-term relationship satisfaction. However, some studies show harmful effects and others show beneficial effects of negative conflict communication on long-term relationship satisfaction. One reason for the heterogeneous results might be that most studies focused on aggregated behaviors across a conflict interaction but neglected the temporal dynamics within such an interaction. This study examined whether individual initial levels and temporal trajectories of negative and positive communications predict long-term relationship satisfaction, and whether self-efficacy beliefs about clarity of other’s feelings (CoF) alter initial levels and temporal trajectories of negative and positive communications. Negative and positive communications were measured based on sequentially coded conflict discussions of 365 couples; self-efficacy beliefs about CoF and relationship satisfaction were measured by self-report questionnaires at baseline and at four annual follow-up assessments. Results revealed that women’s initial positive communication predicted higher intercepts of both partners’ relationship satisfaction, and stronger decreases in women’s negative communication predicted a higher intercept of relationship satisfaction in women. Additionally, less steep decreases in women’s trajectories of negative communication predicted greater maintenance in women’s relationship satisfaction over time. Additionally, men’s self-efficacy beliefs about CoF predicted decreases in men’s negative communication, increases in women’s negative communication, and higher initial levels of women’s positive communication. The current study highlights the relevance of dynamic aspects of partners’ communication behaviors.

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