Hierarchical competition in pond-breeding anuran larvae in a Mediterranean area

2007 ◽  
Vol 28 (2) ◽  
pp. 247-261 ◽  
Author(s):  
Alex Richter-Boix ◽  
Gustavo Llorente ◽  
Albert Montori

AbstractThe anuran larval guild is frequently characterised by the co-occurrence, with high niche overlap, of distinct species in the same pond at variables densities during development. Anuran larvae have therefore been widely studied as a model system for competition. Body size and activity level are considered the most important factors that influence the outcome of competition between tadpoles. As species from temporary ponds normally show higher activity levels in order to achieve rapid growth and thus reduce the risk of desiccation, these species are often considered superior competitors. We designed several laboratory experiments to examine the intra- and interspecific effects on growth rate, mass at metamorphosis and survival to metamorphosis of six species in a Mediterranean area. Body size and activity level were used as explanatory covariables to determine competitive ability among species. An asymmetric and hierarchical relationship was found among the six species. Larger tadpole species were more successful in competitive interactions than smaller ones, but no relationship was found between activity level and competition effects. Species typically found in temporary ponds (Pelodytes punctatus and Bufo calamita) were considered poor competitors in contrast with other communities studied. Species with low competitive ability can persist by using refuges in which competition is reduced (e.g. ephemeral ponds).

Author(s):  
Jennette P. Moreno ◽  
Javad Razjouyan ◽  
Houston Lester ◽  
Hafza Dadabhoy ◽  
Mona Amirmazaheri ◽  
...  

Abstract Objectives and background Social demands of the school-year and summer environment may affect children’s sleep patterns and circadian rhythms during these periods. The current study examined differences in children’s sleep and circadian-related behaviors during the school-year and summer and explored the association between sleep and circadian parameters and change in body mass index (BMI) during these time periods. Methods This was a prospective observational study with 119 children ages 5 to 8 years with three sequential BMI assessments: early school-year (fall), late school-year (spring), and beginning of the following school-year in Houston, Texas, USA. Sleep midpoint, sleep duration, variability of sleep midpoint, physical activity, and light exposure were estimated using wrist-worn accelerometry during the school-year (fall) and summer. To examine the effect of sleep parameters, physical activity level, and light exposure on change in BMI, growth curve modeling was conducted controlling for age, race, sex, and chronotype. Results Children’s sleep midpoint shifted later by an average of 1.5 h during summer compared to the school-year. After controlling for covariates, later sleep midpoints predicted larger increases in BMI during summer, (γ = .0004, p = .03), but not during the school-year. Sleep duration, sleep midpoint variability, physical activity levels, and sedentary behavior were not associated with change in BMI during the school-year or summer. Females tended to increase their BMI at a faster rate during summer compared to males, γ = .06, p = .049. Greater amounts of outdoor light exposure (γ = −.01, p = .02) predicted smaller increases in school-year BMI. Conclusions Obesity prevention interventions may need to target different behaviors depending on whether children are in or out of school. Promotion of outdoor time during the school-year and earlier sleep times during the summer may be effective obesity prevention strategies during these respective times.


2020 ◽  
Author(s):  
Gema Insa-Sánchez ◽  
Lorena Fuentes-Broto ◽  
Alberto Cobos ◽  
Elvira Orduna Hospital ◽  
Francisco Segura ◽  
...  

<b><i>Introduction:</i></b> Our aim was to evaluate the changes in choroidal thickness (CT) and volume (CV) following aerobic physical exercise in healthy young adults. <b><i>Methods:</i></b> This study included 72 eyes from healthy volunteers between 22 and 37 years old. Using the International Physical Activity Questionnaire, total physical activity was computed. Measurements using an autorefractometer, ocular biometry, and spectral-domain optical coherence tomography using the Enhanced Depth Imaging protocol were taken. OCT was performed as a baseline measurement and after performing 10 min of dynamic physical exercise (3 and 10 min post-exercise). The choroidal layer was manually segmented, and the CT and CV in different areas from the Early Treatment Diabetic Retinopathy Study grid were obtained. <b><i>Results:</i></b> In healthy adults, at 3 min post-exercise, CT was higher in the subfoveal, the 3-mm nasal, and the 6-mm superior areas. Between 3 and 10 min post-exercise, the CT was reduced in all areas, and in some areas, the values were even smaller than the baseline measurements. The CV values showed changes after exercise similar to those of thickness. The total CV recovery after exercise was related to sex and physical activity level. <b><i>Conclusion:</i></b> Individuals with higher physical activity habits had greater CV at rest than those with lower physical activity levels. During exercise, healthy young people adjust CT and CV. At 3 min post-exercise, CT and CV increase. Women and individuals with greater physical activity levels reduce their total CV more than others during recovery.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Edward Wright ◽  
Sven Grawunder ◽  
Eric Ndayishimiye ◽  
Jordi Galbany ◽  
Shannon C. McFarlin ◽  
...  

AbstractAcoustic signals that reliably indicate body size, which usually determines competitive ability, are of particular interest for understanding how animals assess rivals and choose mates. Whereas body size tends to be negatively associated with formant dispersion in animal vocalizations, non-vocal signals have received little attention. Among the most emblematic sounds in the animal kingdom is the chest beat of gorillas, a non-vocal signal that is thought to be important in intra and inter-sexual competition, yet it is unclear whether it reliably indicates body size. We examined the relationship among body size (back breadth), peak frequency, and three temporal characteristics of the chest beat: duration, number of beats and beat rate from sound recordings of wild adult male mountain gorillas. Using linear mixed models, we found that larger males had significantly lower peak frequencies than smaller ones, but we found no consistent relationship between body size and the temporal characteristics measured. Taken together with earlier findings of positive correlations among male body size, dominance rank and reproductive success, we conclude that the gorilla chest beat is an honest signal of competitive ability. These results emphasize the potential of non-vocal signals to convey important information in mammal communication.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 60-61
Author(s):  
Elizabeth M Morris ◽  
Susanna E Kitts-Morgan ◽  
Dawn M Spangler ◽  
Kyle R McLeod ◽  
David L Harmon

Abstract Growing public interest in and use of Cannabidiol (CBD) in companion animals has amplified the need to elucidate potential impacts. The purpose of this investigation was to determine the impact of CBD on daily activity of adult dogs. Twenty-four dogs (18.0 ± 3.4 kg) were utilized in a randomized complete block design with treatments consisting of control, 2 mg CBD/kg BW/d, and 4 mg CBD/kg BW/d split between two treats administered after twice-daily exercise (7:00-9:00 and 17:00-19:00). Four hours each day (10:00-12:00, AM and 13:30-15:30, PM), were designated as time when no persons entered the kennels, with 2 h designated as Quiet Time and the other 2 h as Music Time, where calming music played over speakers. Quiet and Music sessions were randomly allotted to daily AM or PM times. Activity monitors were fitted to dogs’ collars for continuous collection of activity parameters. Data were collected over a 2-wk baseline period to block dogs by activity level (high or low) before randomly assigning dogs within each block to treatments. After 1 wk of treatment adaptation, activity parameters were collected for 2 wk. Data were tested for normality using the UNIVARIATE procedure in SAS before examining differences using the MIXED procedure in SAS, including effects of treatment, day, session (Quiet or Music), time of day (AM or PM), and accompanying interactions. CBD did not alter total activity points (P = 0.9971) or activity duration (P = 0.8776). CBD tended (P = 0.0692) to reduce scratching compared to control. Irrespective of treatment, dogs were more active in PM than AM (P &lt; 0.0001). Regardless of session, dogs receiving 4 mg/kg/d tended (P = 0.0914) to be less active in the PM than control. CBD did not affect activity duration during exercise periods (P = 0.1425), but dogs receiving CBD ran more than control (P = 0.0339). These results indicate that when supplemented up to 4 mg/kg/d, CBD does not negatively impact daily activity levels of dogs.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Paulo José Puccinelli ◽  
Taline Santos da Costa ◽  
Aldo Seffrin ◽  
Claudio Andre Barbosa de Lira ◽  
Rodrigo Luiz Vancini ◽  
...  

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic has resulted in a strong negative impact on economic and social life worldwide. It has also negatively influenced people’s general health and quality of life. The aim of the present study was to study the impact of social distancing on physical activity level, and the association between mood state (depression and anxiety level) or sex with actual physical activity levels, the change in physical activity caused by social distancing period, the adhesion level to social distancing, the adoption time of social distancing, family income and age. Methods A self-administered questionnaire with personal, quarantine, physical activity, and mood state disorders information’s was answered by 2140 Brazilians of both sex who were recruited through online advertising. Results The physical activity level adopted during the period of social distancing (3.5 ± 0.8) was lower than that the adopted prior to the pandemic period (2.9 ± 1.1, p < 0.001). Thirty percent of the participants presented symptoms of moderate/severe depression and 23.3% displayed moderate/severe anxiety symptoms. A greater presence of symptoms related to anxiety and depression were associated with low physical activity levels, low family monthly income, and younger age. A higher percentage of men who had no mood disorders was observed among those who were very active than among those less active. Conclusion The COVID-19 pandemic has a negative impact on physical activity. Those who reduced their level of physical activity had the highest levels of mood disorders. Therefore, physical activity programs should be encouraged, while respecting the necessary social distancing to prevent the spread of Severe Acute Respiratory Syndrome Coronavirus 2.


2011 ◽  
Vol 106 (S1) ◽  
pp. S166-S169 ◽  
Author(s):  
Ping Deng ◽  
Ryan W. Grant ◽  
Kelly S. Swanson

The prevalence of feline obesity is influenced by numerous factors, including inactivity and overconsumption of food. The objective of the present study was to evaluate the effect of feeding frequency on physical activity in adult cats. A total of twelve healthy adult cats were used in a cross-over study consisting of 32 d. In each of the two periods, six cats were fed either two meals or four meals daily. Throughout the study, cats were fed the same diet at amounts to maintain body weight and body condition score. Cats were individually housed 4 h/d at each scheduled feeding time, while for the other 20 h, cats were group-housed to allow for voluntary physical activity in the room with a 16 h light–8 h dark cycle. Voluntary activity levels were evaluated using Actical activity collars for seven consecutive days in each period. Daily average activity level for two-meal-fed cats (20·04 (sem 2·19), activity counts/epoch (15 s)) was not different from four-meal-fed cats (20·14 (sem 2·15), activity counts/epoch (15 s); P>0·05). In conclusion, when group-housed cats are fed to maintain their body weight and body condition score, varied feeding frequency between twice and four times daily may not affect activity levels.


Ecology ◽  
1982 ◽  
Vol 63 (6) ◽  
pp. 1780 ◽  
Author(s):  
Clyde E. Goulden ◽  
Linda L. Henry ◽  
Alan J. Tessier

2011 ◽  
Vol 8 (8) ◽  
pp. 1117-1123 ◽  
Author(s):  
Deborah A. Cohen ◽  
Claude Setodji ◽  
Kelly R. Evenson ◽  
Phillip Ward ◽  
Sandra Lapham ◽  
...  

Background:The Systematic Observation of Play and Recreation in Communities (SOPARC) was designed to estimate the number and characteristics of people using neighborhood parks by assessing them 4 times/day, 7 days/week. We tested whether this schedule was adequate and determined the minimum number of observations necessary to provide a robust estimate of park user characteristics and their physical activity levels.Methods:We conducted observations every hour for 14 hours per day during 1 summer and 1 autumn week in 10 urban neighborhood parks: 2 each in Los Angeles, CA; Albuquerque, NM; Columbus, OH; Durham, NC; and Philadelphia, PA. We counted park users by gender, age group, apparent race/ethnicity, and activity level. We used a standardized Cronbach’s alpha and intraclass correlation coefficients to test the reliability of using fewer observations.Results:We observed 76,632 individuals, an average of 547/park/day (range 155−786). Interobserver reliability ranged from 0.80 to 0.99. Obtaining a robust estimate of park user characteristics and their physical activity required a schedule of 4 days/week, 4 times/day.Conclusion:An abbreviated schedule of SOPARC was sufficient for estimating park use, park user characteristics, and physical activity. Applying these observation methods can augment physical activity surveillance.


2003 ◽  
Vol 62 (3) ◽  
pp. 645-650 ◽  
Author(s):  
Klaas R. Westerterp

Activity intensity is a potential determinant of activity-induced energy expenditure. Tri-axial accelerometery is the most objective measurement technique for the assessment of activity intensity, in combination with doubly-labelled water for the measurement of energy expenditure under free-living conditions. Data on the effects of subject characteristics, including body size and age, and exercise training on the relationship between activity intensity and daily energy expenditure are reviewed. Average daily metabolic rate and non-basal energy expenditure are positively related to body size. The duration and intensity of physical activities do not need to be equivalent to the energy spent on activity. Obese subjects spend more energy on physical activity but can perform fewer activities, especially high-intensity (weight-bearing) activities, because of their higher body weight. Physical activity generally declines gradually from about 60 years of age onwards. Most subjects >80 years have an activity level well below the level defined for sedentary middle-aged adults. Spending relatively more time on low-intensity activities has a negative effect on the mean physical activity level. To obtain a higher physical activity level does not necessarily imply high-intensity activities. In an average subject 25% of the activity-induced energy expenditure may be attributed to high-intensity activities. Exercise training, as a form of high-intensity activity, affects the physical activity level more in younger subjects than in elderly subjects.


1993 ◽  
Vol 5 (4) ◽  
pp. 357-366 ◽  
Author(s):  
Hazzaa M. Al-Hazzaa ◽  
Mohammed A. Sulaiman

The present study examined the relationship between maximal oxygen uptake (V̇O2max) and daily physical activity in a group of 7- to 12-year-old boys. V̇O2max was assessed through the incremental treadmill test using an open circuit system. Physical activity level was obtained from heart rate telemetry outside of school time for 8 hrs during weekdays and during 40 min of physical education classes. The findings indicated that the absolute value of V̇O2max increased with age, while relative to body weight it remained almost the same across age, with a mean of 48.4 ml · kg−1 · min−1. Moreover, heart rate telemetry showed that the boys spent a limited amount of time on activities that raise the heart rate to a level above 160 bpm (an average of 1.9%). In addition, V̇O2max was found to be significantly related to the percentage of time spent at activity levels at or above a heart rate of 140 bpm, but not with activity levels at or above a heart rate of 160 bpm.


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