scholarly journals Measuring Behavior in the Home Cage: Study Design, Applications, Challenges, and Perspectives

2021 ◽  
Vol 15 ◽  
Author(s):  
Fabrizio Grieco ◽  
Briana J. Bernstein ◽  
Barbara Biemans ◽  
Lior Bikovski ◽  
C. Joseph Burnett ◽  
...  
Keyword(s):  
Home Cage ◽  
Fine Tuning ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Human Interference ◽  
Working Definition ◽  
Unambiguous Tracking ◽  
Spontaneous Behavior ◽  
Replication Crisis ◽  
The Impact

The reproducibility crisis (or replication crisis) in biomedical research is a particularly existential and under-addressed issue in the field of behavioral neuroscience, where, in spite of efforts to standardize testing and assay protocols, several known and unknown sources of confounding environmental factors add to variance. Human interference is a major contributor to variability both within and across laboratories, as well as novelty-induced anxiety. Attempts to reduce human interference and to measure more "natural" behaviors in subjects has led to the development of automated home-cage monitoring systems. These systems enable prolonged and longitudinal recordings, and provide large continuous measures of spontaneous behavior that can be analyzed across multiple time scales. In this review, a diverse team of neuroscientists and product developers share their experiences using such an automated monitoring system that combines Noldus PhenoTyper® home-cages and the video-based tracking software, EthoVision® XT, to extract digital biomarkers of motor, emotional, social and cognitive behavior. After presenting our working definition of a “home-cage”, we compare home-cage testing with more conventional out-of-cage tests (e.g., the open field) and outline the various advantages of the former, including opportunities for within-subject analyses and assessments of circadian and ultradian activity. Next, we address technical issues pertaining to the acquisition of behavioral data, such as the fine-tuning of the tracking software and the potential for integration with biotelemetry and optogenetics. Finally, we provide guidance on which behavioral measures to emphasize, how to filter, segment, and analyze behavior, and how to use analysis scripts. We summarize how the PhenoTyper has applications to study neuropharmacology as well as animal models of neurodegenerative and neuropsychiatric illness. Looking forward, we examine current challenges and the impact of new developments. Examples include the automated recognition of specific behaviors, unambiguous tracking of individuals in a social context, the development of more animal-centered measures of behavior and ways of dealing with large datasets. Together, we advocate that by embracing standardized home-cage monitoring platforms like the PhenoTyper, we are poised to directly assess issues pertaining to reproducibility, and more importantly, measure features of rodent behavior under more ethologically relevant scenarios.

Time-scale dependent mechanism of atmospheric CO2 concentration drivers of watershed water-energy balance

2021 ◽  
Author(s):  
Jing Zhao
Keyword(s):  
Energy Balance ◽  
River Basin ◽  
Time Scales ◽  
Time Scale ◽  
Hydrological Processes ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
The Wei River Basin ◽  
Balance Dynamics ◽  
The Impact

<p>The elevated atmospheric carbon dioxide concentration (CO<sub>2</sub>), as a key variable linking human activities and climate change, seriously affects the watershed hydrological processes. However, whether and how atmospheric CO<sub>2</sub> influences the watershed water-energy balance dynamics at multiple time scales have not been revealed. Based on long-term hydrometeorological data, the variation of non-stationary parameter n series in the Choudhury's equation in the mainstream of the Wei River Basin (WRB), the Jing River Basin (JRB) and Beiluo River Basin (BLRB), three typical Loess Plateau regions in China, was examined. Subsequently, the Empirical Mode Decomposition method was applied to explore the impact of CO<sub>2</sub> on watershed water-energy balance dynamics at multiple time scales. Results indicate that (1) in the context of warming and drying condition, annual n series in the WRB displays a significantly increasing trend, while that in the JRB and BLRB presents non-significantly decreasing trends; (2) the non-stationary n series was divided into 3-, 7-, 18-, exceeding 18-year time scale oscillations and a trend residual. In the WRB and BLRB, the overall variation of n was dominated by the residual, whereas in the JRB it was dominated by the 7-year time scale oscillation; (3) the relationship between CO<sub>2 </sub>concentration and n series was significant in the WRB except for 3-year time scale. In the JRB, CO<sub>2 </sub>concentration and n series were significantly correlated on the 7- and exceeding 7-year time scales, while in the BLRB, such a significant relationship existed only on the 18- and exceeding 18-year time scales. (4) CO<sub>2</sub>-driven temperature rise and vegetation greening elevated the aridity index and evaporation ratio, thus impacting watershed water-energy balance dynamics. This study provided a deeper explanation for the possible impact of CO<sub>2</sub> concentration on the watershed hydrological processes.</p>

scholarly journals Characterizing the contribution of high temperatures to child undernourishment in Sub-Saharan Africa

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Rachel E. Baker ◽  
Jesse Anttila-Hughes
Keyword(s):  
High Temperatures ◽  
Low Income ◽  
Child Nutrition ◽  
Negative Relationship ◽  
Sub Saharan Africa ◽  
Eastern Africa ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Sub Saharan ◽  
The Impact

Abstract Despite improvements to global economic conditions, child undernourishment has increased in recent years, with approximately 7.5% of children suffering from wasting. Climate change is expected to worsen food insecurity and increase potential threats to nutrition, particularly in low-income and lower-middle income countries where the majority of undernourished children live. We combine anthropometric data for 192,000 children from 30 countries in Sub-Saharan Africa with historical climate data to directly estimate the effect of temperature on key malnutrition outcomes. We first document a strong negative relationship between child weight and average temperature across regions. We then exploit variation in weather conditions to statistically identify the effects of increased temperatures over multiple time scales on child nutrition. Increased temperatures in the month of survey, year leading up to survey and child lifetime lead to meaningful declines in acute measures of child nutrition. We find that the lifetime-scale effects explain most of the region-level negative relationship between weight and temperature, indicating that high temperatures may be a constraint on child nutrition. We use CMIP5 local temperature projections to project the impact of future warming, and find substantial increases in malnutrition depending on location: western Africa would see a 37% increase in the prevalence of wasting by 2100, and central and eastern Africa 25%.

Exploring the role of lags and legacies in the productivity of Australian ecosystems

2021 ◽  
Author(s):  
Jon Page ◽  
Martin De Kauwe ◽  
Gab Abramowitz
Keyword(s):  
Climate Change ◽  
Climate Extremes ◽  
Multiple Time Scales ◽  
Plant Responses ◽  
Multiple Time ◽  
Legacy Effects ◽  
Ecological Memory ◽  
Using Data ◽  
The Impact

<p>The vegetation’s response to climate change is a major source of uncertainty in terrestrial biosphere model (TBM) projections. Constraining carbon cycle feedbacks to climate change requires improving our understanding of both the direct plant physiological responses to global change, as well as the role of legacy effects (e.g. reductions in plant growth, damage to the plant’s hydraulic transport system), that drive multi-timescale feedbacks. In particular, the role of these legacy effects - both the timescale and strength of the memory effect - have been largely overlooked in the development of model hypotheses. This is despite the knowledge that plant responses to climatic drivers occur across multiple time scales (seconds to decades), with the impact of climate extremes (e.g. drought) resonating for many years. Using data from 13 eddy covariance sites, covering two rainfall gradients in Australia, in combination with a hierarchical Bayesian model, we characterised the timescales of influence of antecedent drivers on fluxes of net carbon exchange and evapotranspiration. Using our data assimilation approach we were able to partition the influence of ecological memory into both biological and environmental components. Overall, we found that the importance of ecological memory to antecedent conditions increased as water availability declines. Our results therefore underline the importance of capturing legacy effects in TBMs used to project responses in water limited ecosystems.</p>

New insights about the processes leading to marine extinction at the K-Pg boundary using a coupled biogeochemical-ecosystem model

2020 ◽  
Author(s):  
Le Hir Guillaume ◽  
fluteau fréderic ◽  
Hennequin Salome ◽  
Goddéris Yves
Keyword(s):  
Ecological Model ◽  
Abiotic Factors ◽  
Marine Organisms ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Ecosystem Structure ◽  
Deccan Volcanism ◽  
The Earth ◽  
Chicxulub Impact ◽  
The Impact

<p>If most experts agree that the Cretaceous-Paleogene (K-Pg) extinction (66 Ma) resulted from a combination of the Chicxulub impact and of Deccan volcanism, the chain of reactions (Bond and Wignall, 2014) leading to the extinction is not well constrained. <br> <br> In the present study, we use the GEOCLIM model to explore extreme perturbations induced by the two events and to investigate processes leading to the marine extinction. This state-of-the-art numerical tool (geoclimmodel.wordpress.com) includes in particular a marine ecological model in which food webs are simulated and marine organisms are sensitive to abiotic factors of their environment. The characteristics of each “species” of marine organisms, such as the tolerance to pH or temperature changes or the efficiency of predation, are randomly fixed to avoid any determinism in the response to the environmental perturbations. </p><p>  The response of the Earth system to the onset of Deccan traps and to the Chicxulub impact is explored by forcing the model with the most recent “eruptive sequences”  (Schoene et al., 2019, Sprain et al. 2019) and with the assumption of a pulse-like degassing (Chenet et al. 2009) sequence over 500 kyrs that includes CO2 and SO2. This new approach allows us to take into account the interplays between the sulfur and carbon cycles on multiple time scales (from year to 105  yrs) and to capture the model sensitivity to the uncertainties in atmospheric emissions (duration, timing, nature of gases, intensity of pulses, intensity of the impact).</p><p>  The coupled evolution of the Earth’s climate and oceanic geochemistry during the K-Pg boundary crisis will be presented. Without considering evolution processes, the biotic response (biomass and biodiversity) will be discussed with respect to the ecosystem structure existing before the perturbations. </p>

scholarly journals The Price of Fame: The Impact of Stimulus Familiarity on Proactive Interference Resolution

2011 ◽  
Vol 23 (4) ◽  
pp. 816-831 ◽  
Author(s):  
Ranjani Prabhakaran ◽  
Sharon L. Thompson-Schill
Keyword(s):  
Proactive Interference ◽  
Memory Retrieval ◽  
Recognition Task ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Short Term ◽  
Stimulus Familiarity ◽  
Resolution Processes ◽  
The Impact

Interference from previously learned information, known as proactive interference (PI), limits our memory retrieval abilities. Previous studies of PI resolution have focused on the role of short-term familiarity, or recency, in causing PI. In the present study, we investigated the impact of long-term stimulus familiarity on PI resolution processes. In two behavioral experiments and one event-related fMRI experiment, long-term familiarity was manipulated through the use of famous and nonfamous stimuli, and short-term familiarity was manipulated through the use of recent and nonrecent probe items in an item recognition task. The right middle frontal gyrus demonstrated greater sensitivity to famous stimuli, suggesting that long-term stimulus familiarity plays a role in influencing PI resolution processes. Further examination of the effect of long-term stimulus familiarity on PI resolution revealed a larger behavioral interference effect for famous stimuli, but only under speeded response conditions. Thus, models of memory retrieval—and of the cognitive control mechanisms that guide retrieval processes—should consider the impact of and interactions among sources of familiarity on multiple time scales.

scholarly journals Damage Monitoring in Woven Composites Using Fiber-Bragg Grating Sensors on Multiple Time Scales

2008 ◽  
Author(s):  
Adam Propst ◽  
Adam Parker ◽  
Zachary Capps ◽  
Kara Peters ◽  
Mohammed A. Zikry
Keyword(s):  
Fiber Bragg Grating ◽  
Time Scales ◽  
Sensor Response ◽  
Multiple Time Scales ◽  
Bragg Grating ◽  
Multiple Time ◽  
Low Velocity ◽  
Fbg Sensor ◽  
The Impact ◽  
Impact Events

Low-velocity impact events occurring over the span of a few milliseconds cause changes in composite structures through relaxation and delamination propagation which manifest themselves over the span of several seconds. Changes in embedded fiber Bragg grating sensor response allow the damage in the composite structure to be measured in lieu of simply analyzing the impact event itself. By observing the damage progression and subsequent failure of the sample, the sensor signal response can thus be used to predict the lifetime of the structure. In this paper, we expand previous sensor interrogation and damage identification methodologies by using scanning instrumentation capable of operating over multiple time scales. 2D woven composite specimens are subjected to multiple low velocity impacts while the fiber Bragg grating (FBG) sensor response is monitored in time scales of one millisecond to tens of seconds. A high frequency scanning spectrometer is used to determine the peak Bragg wavelength while scanning the FBG sensor at approximately 1 kHz during and immediately after the impact. Also, a high fidelity slow-scan laser source measures the quasi-static sensor response several seconds to minutes following the impact events. Features of the two measurement sets are used to identify the structural integrity of the laminate specimen after each impact event.

scholarly journals The impact of starbursts on element abundance ratios

2020 ◽  
Vol 498 (1) ◽  
pp. 1364-1381
Author(s):  
James W Johnson ◽  
David H Weinberg
Keyword(s):  
Star Formation ◽  
Chemical Evolution ◽  
Formation Rate ◽  
Theoretical Models ◽  
Asymptotic Giant Branch ◽  
Element Abundance ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Asymptotic Giant Branch Star ◽  
The Impact

ABSTRACT We investigate the impact of bursts in star formation on the predictions of one-zone chemical evolution models, adopting oxygen (O), iron (Fe), and strontium (Sr), as representative α, iron-peak, and s-process elements, respectively. To this end, we develop and make use of the Versatile Integrator for Chemical Evolution (VICE), a python package designed to handle flexible user-specified evolutionary parameters. Starbursts driven by a temporary boost of gas accretion rate create loops in [O/Fe]–[Fe/H] evolutionary tracks and a peak in the stellar [O/Fe] distribution at intermediate values. Bursts driven by a temporary boost of star formation efficiency have similar effects, and they also produce a population of α-deficient stars during the depressed star formation phase following the burst. This α-deficient population is more prominent if the outflow rate is tied to a time-averaged star formation rate (SFR) instead of the instantaneous SFR. Theoretical models of Sr production predict a strong metallicity dependence of supernova and asymptotic giant branch star yields, though comparison to data suggests an additional, nearly metallicity-independent source. Evolution of [Sr/Fe] and [Sr/O] during a starburst is complex because of this metallicity dependence and the multiple time-scales at play. Moderate amplitude (10–20 per cent) sinusoidal oscillations in SFR produce loops in [O/Fe]–[Fe/H] tracks and multiple peaks in [O/Fe] distributions, a potential source of intrinsic scatter in observed sequences. We investigate the impact of a factor ∼2 enhancement of Galactic star formation ∼2 Gyr ago, as suggested by some recent observations. VICE is publicly available at <http://pypi.org/project/vice/>.

scholarly journals Causal contributions of neural noise to left frontal networks subtending the modulation of conscious visual perception in the human brain

2021 ◽  
Author(s):  
Chloé Stengel ◽  
Julià Luis Amengual Roig ◽  
Tristan Moreau ◽  
Antoni Valero-Cabré
Keyword(s):  
Brain Stimulation ◽  
Neural Coding ◽  
Indirect Evidence ◽  
Resonance Phenomenon ◽  
Multiple Time Scales ◽  
Beta Activity ◽  
Multiple Time ◽  
Neural Noise ◽  
High Beta ◽  
The Impact

For several decades, the field of human neurophysiology has focused on the role played by cortical oscillations in enabling brain function underpinning behaviors. In parallel, a less visible but robust body of work on the stochastic resonance phenomenon has also theorized contributions of neural noise - hence more heterogeneous, complex and less predictable activity - in brain coding. The latter notion has received indirect causal support via improvements of visual function during non-regular or random brain stimulation patterns. Nonetheless, direct evidence demonstrating an impact of brain stimulation on direct measures of neural noise is still lacking. Here we evaluated the impact of three non frequency-specific TMS bursts, compared to a control pure high-beta TMS rhythm, delivered to the left FEF during a visual detection task, on the heterogeneity, predictability and complexity of ongoing brain activity recorded with scalp EEG. Our data showed surprisingly that the three non frequency-specific TMS patterns did not prevent a build-up of local high-beta activity. Nonetheless, they increased power across broader or in multiple frequency bands compared to control purely rhythmic high-beta bursts tested along. Importantly, non frequency-specific patterns enhanced signal entropy over multiple time-scales, suggesting higher complexity and an overall induction of higher levels of cortical noise than rhythmic TMS bursts. Our outcomes provide indirect evidence on a potential modulatory role played by sources of stochastic noise on brain oscillations and synchronization. Additionally, they pave the way towards the development of novel neurostimulation approaches to manipulate cortical sources of noise and further investigate their causal role in neural coding.

scholarly journals A study of the influence of forest gaps on fire-atmosphere interactions

2016 ◽  
Author(s):  
Michael T. Kiefer ◽  
Warren E. Heilman ◽  
Shiyuan Zhong ◽  
Joseph J. Charney ◽  
Xindi Bian
Keyword(s):  
Sensible Heat Flux ◽  
Multiple Time Scales ◽  
Multiple Time ◽  
Forest Canopies ◽  
Advanced Regional Prediction System ◽  
Forest Gaps ◽  
Regional Prediction ◽  
Surface Sensible Heat Flux ◽  
The Impact ◽  
Enhanced Surface

Abstract. Much uncertainty exists regarding the possible role that gaps in forest canopies play in modulating fire-atmosphere interactions in otherwise horizontally homogeneous forests. This study examines the impact of forest gaps on fire-atmosphere interactions using the ARPS-CANOPY model, a version of the Advanced Regional Prediction System (ARPS) model with a canopy parameterization. A series of numerical experiments are conducted with a stationary low-intensity fire, represented in the model as a line of enhanced surface sensible heat flux. Experiments are conducted with and without forest gaps, and with gaps in different positions relative to the fireline. For each of the four cases considered, an additional simulation is performed without the fire to facilitate comparison of the fire-perturbed atmosphere and the background state. Analyses of both mean and instantaneous wind velocity, turbulent kinetic energy, air temperature, and turbulent mixing of heat are presented in order to examine the fire-perturbed atmosphere on multiple time scales. Results of the analyses indicate that the impact of the fire on the atmosphere is greatest in the case with the gap centered on the fire, and weakest in the case with the gap upstream of the fire. It is shown that gaps in forest canopies have the potential to play a substantial role in the vertical as well as horizontal transport of heat away from the fire. Results also suggest that in order to understand how the fire will alter wind and turbulence in a heterogeneous forest, one needs to first understand how the forest heterogeneity itself influences the wind and turbulence fields without the fire.

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