scholarly journals Low heritability and high phenotypic plasticity of salivary cortisol in response to environmental heterogeneity in fur seals

2021 ◽  
Author(s):  
Rebecca Nagel ◽  
Sylvia Kaiser ◽  
Claire Stainfield ◽  
Camille Toscani ◽  
Cameron Fox-Clarke ◽  
...  

Individuals are unique in how they interact with and respond to their environment. Correspondingly, unpredictable challenges or stressors often produce an individualized response of the hypothalamic-pituitary-adrenal axis and its downstream effector cortisol. We used a fully crossed, repeated measures design to investigate the factors shaping individual variation in baseline cortisol and cortisol responsiveness in Antarctic fur seal pups and their mothers. Saliva samples were collected from focal individuals at two breeding colonies, one with low and the other with high population density, during two consecutive years of contrasting food availability. Mothers and pups were sampled concurrently at birth and shortly before weaning, while pups were additionally sampled every 20 days. We found that heritability was low for both baseline cortisol and cortisol responsiveness, while within-individual repeatability and among-individual variability were high. A substantial proportion of the variation in baseline cortisol could be explained in pups and mothers by a combination of intrinsic and extrinsic factors including sex, weight, day, season, and colony of birth. However, the same variables explained little of the variation in cortisol responsiveness. Our findings provide detailed insights into the individualization of endocrine phenotypes in a wild pinniped.

2014 ◽  
Vol 44 (15) ◽  
pp. 3315-3328 ◽  
Author(s):  
S. Bhattacharyya ◽  
C. Iyegbe ◽  
Z. Atakan ◽  
R. Martin-Santos ◽  
J. A. Crippa ◽  
...  

Background.What determines inter-individual variability to impairments in behavioural control that may underlie road-traffic accidents, and impulsive and violent behaviours occurring under the influence of cannabis, the most widely used illicit drug worldwide?Method.Employing a double-blind, repeated-measures design, we investigated the genetic and neural basis of variable sensitivity to cannabis-induced behavioural dyscontrol in healthy occasional cannabis users. Acute oral challenge with placebo or Δ9-tetrahydrocannabinol (THC), the main psychoactive ingredient in cannabis, was combined with functional magnetic resonance imaging, while participants performed a response inhibition task that involved inhibiting a pre-potent motor response. They were genotyped for rs1130233 single nucleotide polymorphisms (SNPs) of the protein kinase B (AKT1) gene.Results.Errors of inhibition were significantly (p = 0.008) increased following administration of THC in carriers of the A allele, but not in G allele homozygotes of theAKT1rs1130233 SNP. The A allele carriers also displayed attenuation of left inferior frontal response with THC evident in the sample as a whole, while there was a modest enhancement of inferior frontal activation in the G homozygotes. There was a direct relationship (r = − 0.327,p = 0.045) between the behavioural effect of THC and its physiological effect in the inferior frontal gyrus, whereAKT1genotype modulated the effect of THC.Conclusions.These results require independent replication and show that differing vulnerability to acute psychomotor impairments induced by cannabis depends on variation in a gene that influences dopamine function, and is mediated through modulation of the effect of cannabis on the inferior frontal cortex, that is rich in dopaminergic innervation and critical for psychomotor control.


2002 ◽  
Vol 205 (5) ◽  
pp. 603-612 ◽  
Author(s):  
Isabelle Charrier ◽  
Nicolas Mathevon ◽  
Pierre Jouventin

SUMMARY In the subantarctic fur seal Arctocephalus tropicalis, mothers leave their pups during the rearing period to make long and frequent feeding trips to sea. When a female returns from the ocean, she has to find her pup among several hundred others. Taking into account both spectral and temporal domains, we investigated the individual vocal signature occurring in the ‘female attraction call’ used by pups to attract their mother. We calculated the intra- and inter-individual variability for each measured acoustic cue to isolate those likely to contain information about individual identity. We then tested these cues in playback experiments. Our results show that a female pays particular attention to the lower part of the signal spectrum, the fundamental frequency accompanied by its first two harmonics being sufficient to elicit reliable recognition. The spectral energy distribution is also important for the recognition process. Of the temporal features, frequency modulation appears to be a key component for individual recognition, whereas amplitude modulation is not implicated in the identification of the pup’s voice by its mother. We discuss these results with respect to the constraints imposed on fur seals by a colonial way of life.


Methodology ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Pablo Livacic-Rojas ◽  
Guillermo Vallejo ◽  
Paula Fernández ◽  
Ellián Tuero-Herrero

Abstract. Low precision of the inferences of data analyzed with univariate or multivariate models of the Analysis of Variance (ANOVA) in repeated-measures design is associated to the absence of normality distribution of data, nonspherical covariance structures and free variation of the variance and covariance, the lack of knowledge of the error structure underlying the data, and the wrong choice of covariance structure from different selectors. In this study, levels of statistical power presented the Modified Brown Forsythe (MBF) and two procedures with the Mixed-Model Approaches (the Akaike’s Criterion, the Correctly Identified Model [CIM]) are compared. The data were analyzed using Monte Carlo simulation method with the statistical package SAS 9.2, a split-plot design, and considering six manipulated variables. The results show that the procedures exhibit high statistical power levels for within and interactional effects, and moderate and low levels for the between-groups effects under the different conditions analyzed. For the latter, only the Modified Brown Forsythe shows high level of power mainly for groups with 30 cases and Unstructured (UN) and Autoregressive Heterogeneity (ARH) matrices. For this reason, we recommend using this procedure since it exhibits higher levels of power for all effects and does not require a matrix type that underlies the structure of the data. Future research needs to be done in order to compare the power with corrected selectors using single-level and multilevel designs for fixed and random effects.


2020 ◽  
Author(s):  
Resti Tito Villarino ◽  
Christopher Arcay ◽  
Maria Concepcion Temblor

BACKGROUND Hypertension is a serious health issue and a major cardiovascular disease and stroke risk factor. In hypertensive patients, various health educational models have been used to improve their lifestyle, but the findings are inconsistent. OBJECTIVE The study assessed the effects of a lifestyle intervention program using modified Beliefs, Attitude, Subjective Standards, Enabling Factors (BASNEF) model among non-adherent hypertensive respondents in relation to the introduction of a lifestyle intervention program in the management of hypertension. METHODS This is a quantitative quasi-experimental research particularly utilizing a repeated-measures design of within-subjects approach on the 50 non-adherent patients diagnosed with essential hypertension at Moalboal, Cebu, Philippines in 2019. The respondents received five sessions of trainings based on modified BASNEF model. The Morisky Medication Adherence instrument was used. The first phase included a demographic questionnaire and the last phase comprised the evaluation of the program. Frequencies, percentages, means and standard deviations for descriptive statistics while t-test, repeated measures, ANOVA, and Pearson product moment correlation for inferential statistics. RESULTS The result indicated that the phase 1 mean (146.5) of the systolic readings differ significantly from the phase 4 mean (134.92) of the systolic readings. However, since these two means came from phases that were not consecutive, the result, as a whole, did not show a significant decrease or change when analyzed chronologically from one phase to the next. CONCLUSIONS The study has established that BASNEF model approach can be an effective BP management technique.


Author(s):  
Héctor Guerrero-Tapia ◽  
Rodrigo Martín-Baeza ◽  
Rubén Cuesta-Barriuso

Background. Abdominal and lumbo-pelvic stability alterations may be the origin of lower limb injuries, such as adductor pathology in soccer players. Imbalance can be caused by both intrinsic and extrinsic factors. Methods: In this randomized controlled trial over 8 weeks, 25 female footballers were randomly allocated to an experimental group (isometric abdominal training and gluteus medius-specific training) or a control group (isometric abdominal training). Evaluations were performed at baseline, at the end of the intervention and after a 4-week follow-up period. The exercise protocol in common for both groups included three exercises: Plank, Lateral plank and Bird dog. Specific exercises for the gluteus medius were: Pelvic drop and Stabilization of the gluteus medius in knee valgus. Outcome measures were lumbar-pelvic stability and adductor strength. Results: After the intervention, there was an increase in lumbo-pelvic stability in both groups, being greater in the control group than in the experimental group (mean differences [MD]: 4.84 vs. MD: 9.58; p < 0.01) with differences in the analysis of repeated measures (p < 0.001), but not in group interaction (p = 0.26). Changes were found in adductor strength in the experimental group (MD: −2.48; p < 0.001 in the left adductor; MD: −1.48; p < 0.01 in right adductor) and control group (MD: −1.68; p < 0.001 in the left adductor; MD: −2.05; p < 0.001 in the right adductor) after the intervention, with differences in the analysis of repeated measures in left (p < 0.001) and right (p < 0.001) adductor strength. Conclusions: An abdominal and gluteal training protocol shows no advantage over a protocol of abdominal training alone for lumbo-pelvic stability and adductor strength, while improvements in both variables are maintained at four weeks follow-up.


2020 ◽  
pp. 104973152098235
Author(s):  
Kuei-Min Chen ◽  
Hui-Fen Hsu ◽  
Li-Yen Yang ◽  
Chiang-Ching Chang ◽  
Yu-Ming Chen ◽  
...  

Purpose: This study aimed to test the effectiveness of High-Need Community-Dwelling Older Adults Care Delivery Model (HCOACDM) in Taiwan. Methods: A cluster randomized controlled trial with repeated measures design was conducted in eight community care centers, involving 145 high-need older adults who were assigned to the intervention group or comparison group. The HCOACDM was provided over 6 months. Functional ability, quality of life, depressive symptoms, and health care and social service utilizations were measured at baseline, at 3 months, and 6 months into the intervention. The participants’ satisfaction was measured at the end of 6-month intervention. Results: Positive effects were shown on all variables in the intervention group at both the 3-month and 6-month intervals (all p < .05). The intervention group had a higher satisfaction with care delivery than the comparison group ( p < .05). Discussion: The promising findings supported a long-term implementation of the HCOACDM as applicable and beneficial.


Author(s):  
Nuno Batalha ◽  
Jose A. Parraca ◽  
Daniel A. Marinho ◽  
Ana Conceição ◽  
Hugo Louro ◽  
...  

The purpose of this study was to analyze the acute effects of a standardized water training session on the shoulder rotators strength and balance in age group swimmers, in order to understand whether a muscle-strengthening workout immediately after the water training is appropriate. A repeated measures design was implemented with two measurements performed before and after a standardized swim session. 127 participants were assembled in male (n = 72; age: 16.28 ± 1.55 years, height: 174.15 ± 7.89 cm, weight: 63.97 ± 6.51 kg) and female (n = 55; age: 15.29 ± 1.28 years, height: 163.03 ± 7.19 cm, weight: 52.72 ± 5.48 kg) cohorts. The isometric torque of the shoulder internal (IR) and external (ER) rotators, as well as the ER/IR ratios, were assessed using a hand-held dynamometer. Paired sample t-tests and effect sizes (Cohen’s d) were used (p ≤ 0.05). No significant differences were found on the shoulder rotators strength or balance in males after training. Females exhibited unchanged strength values after practice, but there was a considerable decrease in the shoulder rotators balance of the non-dominant limb (p < 0.01 d = 0.366). This indicates that a single practice seems not to affect the shoulders strength and balance of adolescent swimmers, but this can be a gender specific phenomenon. While muscle-strengthening workout after the water session may be appropriate for males, it can be questionable regarding females. Swimming coaches should regularly assess shoulder strength levels in order to individually identify swimmers who may or may not be able to practice muscle strengthening after the water training.


2017 ◽  
Vol 3 (3) ◽  
pp. 88-93 ◽  
Author(s):  
Maureen Anne Jersby ◽  
Paul Van-Schaik ◽  
Stephen Green ◽  
Lili Nacheva-Skopalik

BackgroundHigh-Fidelity Simulation (HFS) has great potential to improve decision-making in clinical practice. Previous studies have found HFS promotes self-confidence, but its effectiveness in clinical practice has not been established. The aim of this research is to establish if HFS facilitates learning that informs decision-making skills in clinical practice using MultipleCriteria DecisionMaking Theory (MCDMT).MethodsThe sample was 2nd year undergraduate pre-registration adult nursing students.MCDMT was used to measure the students’ experience of HFS and how it developed their clinical decision-making skills. MCDMT requires characteristic measurements which for the learning experience were based on five factors that underpin successful learning, and for clinical decision-making, an analytical framework was used. The study used a repeated-measures design to take two measurements: the first one after the first simulation experience and the second one after clinical placement. Baseline measurements were obtained from academics. Data were analysed using the MCDMT tool.ResultsAfter their initial exposure to simulation learning, students reported that HFS provides a high-quality learning experience (87%) and supports all aspects of clinical decision-making (85%). Following clinical practice, the level of support for clinical decision-making remained at 85%, suggesting that students believe HFS promotes transferability of knowledge to the practice setting.ConclusionOverall, students report a high level of support for learning and developing clinical decision-making skills from HFS. However, there are no comparative data available from classroom teaching of similar content so it cannot be established if these results are due to HFS alone.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yanzhi Bi ◽  
Xin Hou ◽  
Jiahui Zhong ◽  
Li Hu

AbstractPain perception is a subjective experience and highly variable across time. Brain responses evoked by nociceptive stimuli are highly associated with pain perception and also showed considerable variability. To date, the test–retest reliability of laser-evoked pain perception and its associated brain responses across sessions remain unclear. Here, an experiment with a within-subject repeated-measures design was performed in 22 healthy volunteers. Radiant-heat laser stimuli were delivered on subjects’ left-hand dorsum in two sessions separated by 1–5 days. We observed that laser-evoked pain perception was significantly declined across sessions, coupled with decreased brain responses in the bilateral primary somatosensory cortex (S1), right primary motor cortex, supplementary motor area, and middle cingulate cortex. Intraclass correlation coefficients between the two sessions showed “fair” to “moderate” test–retest reliability for pain perception and brain responses. Additionally, we observed lower resting-state brain activity in the right S1 and lower resting-state functional connectivity between right S1 and dorsolateral prefrontal cortex in the second session than the first session. Altogether, being possibly influenced by changes of baseline mental state, laser-evoked pain perception and brain responses showed considerable across-session variability. This phenomenon should be considered when designing experiments for laboratory studies and evaluating pain abnormalities in clinical practice.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Chinedu Anthony Iwu ◽  
Kenechi Uwakwe ◽  
Uche Oluoha ◽  
Chukwuma Duru ◽  
Ernest Nwaigbo

Abstract Background Adequate immunization coverage in rural communities remain a challenge in Nigeria. Traditional birth attendants (TBAs) form an integral part of the social, cultural and religious fabric in most rural communities in Nigeria. Despite their limitations in handling the complications of childbirth, TBAs are widely accepted and patronized, especially in rural areas. The objectives of the project were to empower TBAs and assess the use of a culturally adapted audio-visual workshop intervention to change their knowledge, attitude and willingness to promote immunization uptake. Methods A repeated-measures design that used a convenience sampling technique to select 90 TBAs from the three geopolitical zones of Imo State, Nigeria. The TBAs were engaged through a culturally adapted audio-visual workshop. Data were collected before and immediately after intervention using a pretested questionnaire. Chi square test was done to determine any significant association with the zone of practice and paired sample t-test analysis to determine any significant pre and post intervention change. Level of significance was set at p ≤ ·05. Results More than half of the TBAs had at most, a secondary level of education (54·4%). The average length of time they practiced as TBAs was 16 years with an average of ten birth deliveries per month. After the intervention, all the respondents (100%) reported a willingness to always promote immunization uptake and also, there was a statistically significant increase in Knowledge (p < ·000). Similarly, the level of knowledge in the post intervention period appeared to be significantly associated with the zone of practice (p = ·027). Conclusion The workshop intervention empowered the TBAs irrespective of their zones of residence by successfully improving their knowledge, though at varying levels; and consequently, their willingness to always promote immunization uptake.


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