scholarly journals Functions for simulating data and designing studies of physiological flexibility in the acute glucocorticoid response to stressors.

2021 ◽  
Author(s):  
Conor Taff
Keyword(s):  
Empirical Studies ◽  
Data Simulation ◽  
Response Curves ◽  
Response Data ◽  
Acute Response ◽  
Glucocorticoid Response ◽  
Acute Responses ◽  
Powerful Approach ◽  
And Behavior ◽  
Physiological Flexibility

Wild animals often experience unpredictable challenges that demand rapid and flexible responses. The glucocorticoid mediated stress response is one of the major systems that allows vertebrates to rapidly adjust their physiology and behavior. Given its role in responding to challenges, evolutionary physiologists have focused on the consequences of between-individual and, more recently, within-individual variation in the acute glucocorticoid response. Although sophisticated approaches are available to partition this variation statistically, empirical studies of physiological flexibility are severely limited by the logistical challenges of measuring the same animal multiple times during a single acute response or across multiple instances of acute responses. Empiricists have largely adopted the strategy of standardizing sampling as much as possible to allow for comparison between individuals, but this standardization also makes it very difficult to detect certain types of variation in the functional shape of acute response curves. Data simulation is a powerful approach when empirical data are limited, but has not been adopted to date in studies of physiological flexibility. In this paper, I describe the simcoRt package, which includes functions that can generate realistic acute glucocorticoid response data with user specified characteristics. Simulated animals can be sampled continuously through an acute response and across as many separate responses as desired, while varying key parameters (e.g., the degree of correlation between the speed and scope of a response). Using this simulation, I explore several possible scenarios to highlight areas where simulation might either provide new insight into physiological flexibility directly or aid in designing empirical studies that are better able to test the hypotheses of interest.

Culture, names and economic development

2016 ◽  
pp. 81-106
Author(s):  
E. Borisova ◽  
A. Kulkova
Keyword(s):  
Economic Development ◽  
Cultural Identity ◽  
Empirical Studies ◽  
Economic Research ◽  
Cultural Norms ◽  
Individual Values ◽  
Personal Names ◽  
Economic Significance ◽  
And Behavior

Various components of culture have long been in the focus of economic research. Numerous empirical studies show that cultural norms, as well as religion and language, matter for economic development and have not only statistical but also economic significance. This paper considers various examples of how culture can affect individual values and behavior. It also deals with personal names as a key marker of one’s cultural identity. Overall, the paper contributes to the more profound understanding of a famous notion that "culture matters", and helps clarify the mechanisms through which culture exerts its influence.

scholarly journals Major renovations of apartment complexes: Russian people’s projective attitudes and behavior practices

2020 ◽  
Vol 11 (4) ◽  
pp. 190-211
Author(s):  
Anna V. Ermishina ◽  
Lyudmila V. Klimenko
Keyword(s):  
Decision Making ◽  
Common Property ◽  
Empirical Studies ◽  
European Social Survey ◽  
Actual Behavior ◽  
Apartment Buildings ◽  
Public Property ◽  
Property Owners ◽  
And Behavior ◽  
Attitudes And Behavior

This article analyzes the Russian people’s projective attitudes and behavior practices when it comes to participating in the funding and organizing of major renovations of apartment buildings. The empirical base for the study consists of data from sociological surveys conducted by VCIOM (2015-2020), the Institute of Sociology of the RAS (2003-2019), FOM (2015), Levada Center (2019), The European Social Survey (2016, 2018), as well as the authors’ own expert interviews conducted in 2020. The need to ensure the safety of housing, the complexity and high cost of renovations is a reasonable explanation for government interference in this sector. Russia’s housing legislature assigns responsibility for maintaining and renovating common property to apartment owners, while also stipulating a funding procedure for major renovations based on deposits made by property owners. The system currently in place in Russia for funding and organizing major renovations, which implies the existence of both a “common reserve” and “special accounts” for regulated property owner contributions (that resemble a tax), is far from perfect, it being associated with such issues as a lack of funding, low quality of major renovations, susceptibility to corruption, owners having insufficient control when it comes to decision making. While analyzing material from all-Russian and regional empirical studies, the gap becomes evident between projective attitudes and the actual behavior of Russian people in the realm of major renovations. Despite a marked critical attitude when it comes to evaluating utility service quality, not to mention the “common reserve” model (which is a way of pulling together funds for major renovations and keeping them on the regional operator’s account) being regarded as socially unjust, nevertheless property owners demonstrate a low degree of civic self-organization and meager capability when it comes to taking collective action (as in participating in apartment complex meetings to discuss major renovations, creating and transferring money to dedicated accounts, keeping track of the major renovation process etc.). The reasons why property owners are so slow to develop any efficiency largely lie in the specifics of the institutional collective decision-making environment in regards to the funding and execution of local public property renovation, which also includes major renovations of apartment buildings.

Estimation of response curves in closed-loop physiological control

1986 ◽  
Vol 61 (4) ◽  
pp. 1481-1491 ◽  
Author(s):  
C. S. Poon
Keyword(s):  
Least Squares ◽  
Closed Loop ◽  
Ordinary Least Squares ◽  
Repeated Measurements ◽  
System Structure ◽  
Paired Data ◽  
Response Curves ◽  
Response Data ◽  
Error Components ◽  
Response Slope

Several recent reports have addressed the problem of estimating the response slope from repeated measurements of paired data when both stimulus and response variables are subject to biological variability. These earlier approaches suffer from several drawbacks: useful information about the relationships between the error components in a closed-loop system is not fully utilized; the response intercept cannot be directly estimated; and the normalization procedure required in some methods may fail under certain circumstances. This paper proposes a new, general method of simultaneously estimating the response slope and intercept from corrupted stimulus-response data when the errors in both variables are specifically related by the system structure. A direct extension of the least-squares approach, this method [directed least squares (DLS)] reduces to ordinary least-squares methods when either of the measured variables is error free and to the reduced-major-axis (RMA) method of Kermack and Haldane (Biometrics 37: 30-41, 1950) when the magnitudes of the normalized errors are equal. The DLS estimators are scale invariant, statistically unbiased and always assume the minimum variance. With simple modifications, the method is also applicable to paired data. If, however, the relation between error components is uncertain, then the RMA method is optimal, i.e., having the least possible asymptotic bias and variance. These results are illustrated by using various types of closed-loop respiratory response data.

scholarly journals Multiple Functional Solutions During Flightless to Flight-Capable Transitions

2021 ◽  
Vol 8 ◽  
Author(s):  
Ashley M. Heers ◽  
Stephanie L. Varghese ◽  
Leila K. Hatier ◽  
Jeremiah J. Cabrera
Keyword(s):  
Empirical Studies ◽  
Three Dimensional ◽  
Muscle Size ◽  
Whole Body ◽  
Ontogenetic Changes ◽  
Skeletal Morphology ◽  
Avian Flight ◽  
And Performance ◽  
Locomotor Behaviors ◽  
And Behavior

The evolution of avian flight is one of the great transformations in vertebrate history, marked by striking anatomical changes that presumably help meet the demands of aerial locomotion. These changes did not occur simultaneously, and are challenging to decipher. Although extinct theropods are most often compared to adult birds, studies show that developing birds can uniquely address certain challenges and provide powerful insights into the evolution of avian flight: unlike adults, immature birds have rudimentary, somewhat “dinosaur-like” flight apparatuses and can reveal relationships between form, function, performance, and behavior during flightless to flight-capable transitions. Here, we focus on the musculoskeletal apparatus and use CT scans coupled with a three-dimensional musculoskeletal modeling approach to analyze how ontogenetic changes in skeletal anatomy influence muscle size, leverage, orientation, and corresponding function during the development of flight in a precocial ground bird (Alectoris chukar). Our results demonstrate that immature and adult birds use different functional solutions to execute similar locomotor behaviors: in spite of dramatic changes in skeletal morphology, muscle paths and subsequent functions are largely maintained through ontogeny, because shifts in one bone are offset by changes in others. These findings help provide a viable mechanism for how extinct winged theropods with rudimentary pectoral skeletons might have achieved bird-like behaviors before acquiring fully bird-like anatomies. These findings also emphasize the importance of a holistic, whole-body perspective, and the need for extant validation of extinct behaviors and performance. As empirical studies on locomotor ontogeny accumulate, it is becoming apparent that traditional, isolated interpretations of skeletal anatomy mask the reality that integrated whole systems function in frequently unexpected yet effective ways. Collaborative and integrative efforts that address this challenge will surely strengthen our exploration of life and its evolutionary history.

Sentiments as Status Processes? A Theoretical Reformulation from the Expectation States Tradition

2020 ◽  
Vol 38 (3) ◽  
pp. 217-235
Author(s):  
Alison J. Bianchi ◽  
Robert K. Shelly
Keyword(s):  
Social Inequality ◽  
Empirical Studies ◽  
Theoretical Framework ◽  
Task Group ◽  
Performance Expectations ◽  
Task Groups ◽  
Expectation States ◽  
Status Characteristics ◽  
Group Members ◽  
And Behavior

Do the ties that bind also create social inequality? Using an expectation states theoretical framework, we elaborate status characteristics and behavior-status theories to explore how sentiments, network connections based on liking and disliking, may affect processes entailing status, the prestige based on one’s differentially valued social distinctions. Within task groups, we theorize that positive and negative sentiments may themselves be status elements capable of evoking performance expectations within dyadic configurations typically modeled by expectation states theorists. Having a reputation for being liked or disliked “imported” into the group may enact status generalization. Alternatively, a status element based on sentiments may emerge during task group interaction as group members ascertain if alters are liked or disliked. Finally, we conclude by discussing how our theorizing motivates future theories and empirical studies.

A General Measure of In Vitro Phototoxicity Derived from Pairs of Dose-Response Curves and its Use for Predicting the In Vivo Phototoxicity of Chemicals

1997 ◽  
Vol 25 (4) ◽  
pp. 445-462 ◽  
Author(s):  
Hermann-Georg Holzhütter
Keyword(s):  
Dose Response ◽  
Uv Light ◽  
Test System ◽  
Maximal Response ◽  
Response Curves ◽  
General Measure ◽  
Absolute Change ◽  
Response Data ◽  
Dose Response Curves ◽  
The Absolute

In pharmacology, it is common to evaluate the influence of external effectors (for example, temperature, pH, and presence of a second drug) on dose-response relations by the potency factor (PF50): [Formula: see text] where ED50 (± effector) denotes the 50% effective dose in the presence and in the absence of the effector, respectively. In this paper, the external effector is ultraviolet (UV) light, and PF50 is referred to as the photoirritancy factor (PIF). There are two parameters which limit the applicability and toxicological reliability of the PIF. Firstly, the physical properties (for example, water solubility) of the chemical tested and the constraints of the biological test system may make it difficult, or even impossible, to achieve sufficiently high doses to observe 50% of the maximal response. In such cases, no numeric value of the potency factor can be computed. Secondly, the potency factor does not take into account the absolute change in response induced by UV light, i.e. depending on the shape of the ±UV dose-response curves, the absolute change in response may be small although the PIF is large, and vice versa. This paper proposes a more general measure of phototoxicity, the mean photo effect (MPE), which can be assessed from pairs of dose-response curves, even if the 50% response level is not reached in one curve or in both. The MPE is a weighted average of PIFd values across different dose levels (d being common to both dose-response curves). The absolute response changes, ΔRd, i.e. the differences between the -UV curve and the +UV curve are used as weighting factors. The numerical computation of the MPE is based on theoretical curves obtained by fitting a mathematical model to the experimental dose-response data. Plotting PIFd and ΔRd versus the corresponding doses permits differences in the shapes of the two curves to be assessed, and possible alterations in the toxic mechanisms induced by UV light to be revealed. The variance of MPE is estimated by a bootstrap procedure. The use of the MPE is illustrated by its application to dose-response data obtained with a human keratinocyte assay of fibroblasts in the EU/COLIPA international validation project on photoirritancy.

The guinea pig tracheobronchial spiral strip: responses to selected agonists

1978 ◽  
Vol 56 (5) ◽  
pp. 823-827 ◽  
Author(s):  
C. J. Hanna ◽  
S. H. Roth
Keyword(s):  
Regression Analysis ◽  
Guinea Pig ◽  
Dose Response ◽  
Effective Concentration ◽  
Relative Order ◽  
Response Curves ◽  
Response Data ◽  
Significant Difference ◽  
Dose Dependent

The guinea pig tracheal spiral strip is a useful preparation for studying bronchoconstrictor and bronchodilator compounds. Employing a simple and rapid modification of this technique, experiments were performed in vitro to quantitate the effects of selected bronchospastic agents on guinea pig tracheobronchial smooth muscle. Three sections of the main airways were prepared from each animal: an upper tracheal, a lower tracheal, and a bronchial segment. The dose-dependent contractile responses of the three tissue segments were determined for carbachol, acetylcholine, histamine, 5-hydroxytryptamine, and bradykinin, Differences were observed amongst the agonists in magnitudes of contraction, effective concentration ranges, and slopes of dose–response curves. ED25, ED50, and ED75, values were calculated from regression analysis of dose–response data. The relative order for these agents to produce maximum contractions was found to be carbachol [Formula: see text] acetylcholine > histamine > 5-hydroxytryptamine > bradykinin. Furthermore, it was found that there was no significant difference between the three tissue segments in their responses to the various agonists.

scholarly journals Pasture yield responses to irrigation in Canterbury

1994 ◽  
pp. 165-168 ◽  
Author(s):  
S.D. Mcbride
Keyword(s):  
Soil Moisture ◽  
Drop Out ◽  
Yield Response ◽  
Research Station ◽  
Response Curves ◽  
Response Data ◽  
Term Trial ◽  
Water Restrictions ◽  
Yield Responses

Major findings from 13 pasture irrigation experiments conducted in Canterbury are discussed. Yields and response curves on 8 of the experimental sites were very similar to those of the long-term trial (34 years) site at the Winchmore Research Station. Irrigating when soil moisture dried to 50% asm (available soil moisture), increased annual pasture DM yields by an average of 5.2 t/ha DM (80% increase over the non-irrigated yield). Response per irrigation and yield variation between years decreased as the number of irrigations increased. During water restrictions, irrigators often choose to either keep watering their whole farm with a longer irrigation return period, or drop out paddocks and fully irrigate the remainder. The irrigation response data are used to discuss these and other possible strategies. Keywords: irrigation, pasture yields, response curves, water restrictions

scholarly journals Acute renal denervation normalizes aortic function and decreases blood pressure in spontaneously hypertensive rats

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nathalia Juocys Dias Moreira ◽  
Fernando dos Santos ◽  
Edson Dias Moreira ◽  
Daniela Farah ◽  
Leandro Eziquiel de Souza ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Renal Denervation ◽  
Vascular Reactivity ◽  
Urinary Volume ◽  
Hypertensive Rats ◽  
Response Curves ◽  
Spontaneously Hypertensive ◽  
Functional Changes ◽  
Sham Surgery ◽  
Acute Responses

AbstractMechanisms involved in the acute responses to renal denervation (RDN) have yet to be fully understood. We assessed urinary volume, autonomic control and aorta vascular reactivity after acute RDN. Male normotensive Wistar rats and spontaneously hypertensive rats (SHR) were divided into normotensive + RDN (ND) or sham surgery (NS), and hypertensive + RDN (HD) or sham surgery (HS). Metabolic parameters and hemodynamic measurements were recorded 72h and 4 days after intervention, respectively. Aortic rings were studied 7 days post RDN in an isometric myograph. Concentration–response curves to phenylephrine, sodium nitroprusside and acetylcholine (10–10–10−5 M) were performed. Two-way ANOVA was used for group comparisons and differences reported when p < 0.05. Results are presented as mean ± SEM. Urinary volume was 112% higher in HD vs. HS (HS = 14.94 ± 2.5 mL; HD = 31.69 ± 2.2 mL) and remained unchanged in normotensive rats. Systolic BP was lower in HD rats (HS = 201 ± 12 vs. HD = 172 ± 3 mmHg) without changes in normotensive group. HD group showed increased HF and LF modulation (HS = 5.8 ± 0.7 ms2vs. HD = 13.4 ± 1.4 ms2; HS = 3.5 ± 0.7 ms2vs. HD = 10.5 ± 1.7 ms2, respectively). RDN normalized vascular reactivity in HD rats and increased phenylephrine response in ND rats. Acute fall in BP induced by RDN is associated with increased urinary volume, which in turn may also have contributed to functional changes of the aorta.

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