scholarly journals Male and female guppies differ in problem-solving abilities

2019 ◽  
Vol 66 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Tyrone Lucon-Xiccato ◽  
Elia Gatto ◽  
Angelo Bisazza

Abstract In a number of species, males and females have different ecological roles and therefore might be required to solve different problems. Studies on humans have suggested that the 2 sexes often show different efficiencies in problem-solving tasks; similarly, evidence of sex differences has been found in 2 other mammalian species. Here, we assessed whether a teleost fish species, the guppy, Poecilia reticulata, displays sex differences in the ability to solve problems. In Experiment 1, guppies had to learn to dislodge a disc that occluded a feeder from which they had been previously accustomed to feed. In Experiment 2, guppies had to solve a version of the detour task that required them to learn to enter a transparent cylinder from the open sides to reach a food reward previously freely available. We found evidence of sex differences in both problem-solving tasks. In Experiment 1, females clearly outperformed males, and in Experiment 2, guppies showed a reversed but smaller sex difference. This study indicates that sex differences may play an important role in fish’s problem-solving similar to what has previously been observed in some mammalian species.

2021 ◽  
pp. svn-2020-000834
Author(s):  
Koteswara Rao Nalamolu ◽  
Bharath Chelluboina ◽  
Casimir A Fornal ◽  
Siva Reddy Challa ◽  
David M Pinson ◽  
...  

Background and purposeThe therapeutic potential of different stem cells for ischaemic stroke treatment is intriguing and somewhat controversial. Recent results from our laboratory have demonstrated the potential benefits of human umbilical cord blood-derived mesenchymal stem cells (MSC) in a rodent stroke model. We hypothesised that MSC treatment would effectively promote the recovery of sensory and motor function in both males and females, despite any apparent sex differences in post stroke brain injury.MethodsTransient focal cerebral ischaemia was induced in adult Sprague-Dawley rats by occlusion of the middle cerebral artery. Following the procedure, male and female rats of the untreated group were euthanised 1 day after reperfusion and their brains were used to estimate the resulting infarct volume and tissue swelling. Additional groups of stroke-induced male and female rats were treated with MSC or vehicle and were subsequently subjected to a battery of standard neurological/neurobehavioral tests (Modified Neurological Severity Score assessment, adhesive tape removal, beam walk and rotarod). The tests were administered at regular intervals (at days 1, 3, 5, 7 and 14) after reperfusion to determine the time course of neurological and functional recovery after stroke.ResultsThe infarct volume and extent of swelling of the ischaemic brain were similar in males and females. Despite similar pathological stroke lesions, the clinical manifestations of stroke were more pronounced in males than females, as indicated by the neurological scores and other tests. MSC treatment significantly improved the recovery of sensory and motor function in both sexes, and it demonstrated efficacy in both moderate stroke (females) and severe stroke (males).ConclusionsDespite sex differences in the severity of post stroke outcomes, MSC treatment promoted the recovery of sensory and motor function in male and female rats, suggesting that it may be a promising treatment for stroke.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Yujie Zhu ◽  
Steven M Pogwizd

Introduction: Females can be more arrhythmogenic than males, and this sex difference can persist with development of chronic heart failure (CHF). The aim of this study was to investigate sex differences in the arrhythmogenic substrate in control dogs and in a new arrhythmogenic canine model of CHF. Methods: CHF was induced in 30 dogs by aortic insufficiency and aortic constriction. Holter monitoring assessed VT and PVCs from 30 dogs, as well as traditional HRV measures and nonlinear dynamics (including correlation dimension (CD), detrended fluctuations analysis α1 (DFAα1), and Shannon entropy (SE)) at baseline, 240 days (240d) and 720 days (720d) after CHF induction. Results: At baseline, females had lower LF/HF (0.27±0.03 vs 0.33±0.02, p=0.04), CD (1.60±0.17 vs 2.21±0.15, p=0.01), DFAα1 (0.62±0.03 vs 0.72±0.03, p=0.03), and SE (2.99±0.02 vs 3.10±0.03, p=0.03 vs males). Females lacked circadian variation in LF/HF, DFAα1, and SE while males had circadian variation in all of these. Of 11 dogs with frequent runs of VT and PVCs, 95% and 91% of total VT runs and total PVCs, respectively, were in females. With CHF, all these linear and nonlinear parameters progressively declined in males and females. CHF females had less decline in LF/HF than males so that by 720 days there was no more sex difference (0.24±0.06, 0.17±0.03 in females vs 0.22±0.05, 0.18±0.01 in males at 240d, 720d). However, for nonlinear parameters of CD, DFAα1, and SE, CHF females had lower values than males (CD: 1.56±0.21, 0.99±0.32 vs 1.87±0.24, 1.50±0.34; DFAα1: 0.51±0.05, 0.43±0.04 vs 0.54±0.07, 0.48±0.04; and SE 2.93±0.08, 2.76±0.08 vs 3.01±0.11, 2.91±0.04 in females vs males at 240d, 720d). With CHF, circadian variation in CD, DFAα1, and SE were lost in both males and females. Conclusions: There are sex differences in the arrhythmogenic substrate in control dogs and in this new arrhythmogenic canine model of moderate CHF. At baseline, females have lower sympathetic stimulation, reduced cardiac chaos, and loss of circadian variation in nonlinear dynamics. With CHF, sex differences in nonlinear dynamics persist; this reflects a loss of complexity and fractal properties that could contribute to increased arrhythmias in female CHF dogs.


1975 ◽  
Vol 40 (2) ◽  
pp. 409-410 ◽  
Author(s):  
Robert H. Heying ◽  
Karen Korabik ◽  
David C. Munz

Differences between male and female guilt reactions to hypothetical guilt-inducing situations of a sexual, hostile, and moral nature were investigated. Two independent samples of Ss (56 men, 56 women; and 34 men, 62 women) reported the intensity of their anticipated guilt reactions to 60 hypothetical behavior situations presented in sentence-completion format through the use of scaled response alternatives. Across both samples there were specific behaviors in which stable sex differences were evidenced, i.e., females' reactions were more intense for those behaviors reflecting sexual transgressions. However, males and females were highly similar in their reactions to hostile and moral guilt-provoking situations. Implications of these results for research on trait-guilt were discussed.


Genus ◽  
2022 ◽  
Vol 78 (1) ◽  
Author(s):  
Helena Cruz Castanheira ◽  
José Henrique Costa Monteiro da Silva

AbstractThe production, compilation, and publication of death registration records is complex and usually involves many institutions. Assessing available data and the evolution of the completeness of the data compiled based on demographic techniques and other available data sources is of great importance for countries and for having timely and disaggregated mortality estimates. In this paper, we assess whether it is reasonable, based on the available data, to assume that there is a sex difference in the completeness of male and female death records in Peru in the last 30 years. In addition, we assess how the gap may have evolved with time by applying two-census death distribution methods on health-related registries and analyzing the information from the Demographic and Health Surveys and civil registries. Our findings suggest that there is no significant sex difference in the completeness of male and female health-related registries and, consequently, the sex gap currently observed in adult mortality estimates might be overestimated.


2021 ◽  
Author(s):  
Ben Mansour Ghassen ◽  
Kacem Asma ◽  
Ishaq Mohamed ◽  
Grélot Laurent ◽  
Ftaiti Foued

Abstract Purpose - The Aim of this study is to determine and to compare the impact of fat excess on neuromuscular performances during short maximal exercise in male and female students. Methods - 72 male and 64 female students aged 20 to 23 years were enrolled in this study. After assessing their morphological characteristics (body mass, height and percentage of fat mass), a squat jump test (SJ), a 5 successive jump test (5JT), a hand gripping (HG) and back strength (BS) tests have been conducted for each subject. Male students were re-tested after being weighed down with a weight equivalent to the mean differences in body fat recorded between the two sexes in the form of a loaded worn vest. Results – Male are 15.7% heavier and 7.4% taller and presented a percentage of fat mass (17.2 ± 1.8%) significantly (p<0.001) lower than that of women subject (25.0 ± 2.5%) (difference male vs female for fat mass: -45.5%). HG, BS, 5JT and SJ performances were significantly higher in males (44±5 kg, 141±2 kg, 11±1 m and 32.4 ± 2,7 cm, respectively) than in females (31.0±4 kg, 81.6±13 kg, 8.7 ± 0.7 m and 21.1 ± 1.9 cm, respectively. In the control (unloaded) condition, the relative difference between males and females represented 23.5% and 34.7% of the male performances for 5JT and SJ, respectively. In the weighted condition, the relative difference between weighted males and females still represented 11.7% and 23.8% of the weighted male performances for 5JT and SJ, respectively. Cancelling the sex difference in fat mass by adding weight in males reduced by 50.1% the sex difference during 5JT and 31.4% and 71.7% for hight and power results, respectively during SJ test. Conclusion – During short and maximal exercise, male performed better with their hands, back and legs than female students. Excess fat for female students have a disadvantageous effect on vertical and horizontal jumps performances. The persistence of sex differences after weighting of male students indicates that body fat is responsible for 30 to 70 % of the observed differences between sexes performances and power outcome during jump tests.


1976 ◽  
Vol 43 (2) ◽  
pp. 399-402 ◽  
Author(s):  
George R. Jacobson ◽  
Ann Van Dyke ◽  
Theodore G. Sternbach ◽  
Russell Brethauer

402 males and 160 females hospitalized for treatment of alcoholism were tested in a standardized manner on the Rod-and-frame test as a means of supplementing an earlier report of normative data on perceptual style among male alcoholics. When their performance was contrasted with that of normal and psychiatric samples, alcoholics were clearly the most field dependent of all groups studied. Statistically significant sex differences justify the need for separate norms for males and females.


1965 ◽  
Vol 17 (2) ◽  
pp. 532-534 ◽  
Author(s):  
Ronald J. Burke

Previous research has shown the superiority of performance of males over that of females in solving Maier's horse trading problem. This investigation represented an attempt to reduce this sex difference by requiring Ss only to recognize the correct answer and its underlying reason. Consistent with earlier findings, 67.4% of the males and 34.2% of the females correctly solved the problem ( p < .01). Comparison with results of Hoffman and Maier (1961) suggests that the modified version of the problem had little effect on the percentage of males and females correctly solving the problem.


1983 ◽  
Vol 244 (1) ◽  
pp. R93-R105 ◽  
Author(s):  
F. C. Davis ◽  
J. M. Darrow ◽  
M. Menaker

The circadian pacemaker that underlies the wheel-running activity of hamsters was studied in males and females. Sex differences were found in the mechanism by which the pacemaker entrains to light-dark cycles and in the timing of activity onset. When exposed to a light-dark cycle with a period of 24.75 h (with 1 h of light/cycle), males show a greater ability to maintain entrainment than do females. This difference in the upper limit of entrainment appears due to a sex difference in the magnitude of light-induced phase shifts. A small difference in free-running period may also contribute to the sex difference in entrainment. Two weeks after castration of adults, the sex difference in entrainment is not affected, indicating that the difference does not depend on circulating gonadal steroids or on estrous cyclicity of the female. However, castration of females at an early age increases their ability to entrain, whereas long-term castration of males seems to reduce entrainment ability. During entrainment to a 24-h light-dark cycle (LD 14:10), females were found to begin their daily activity before males and before castrated females. This difference is consistent with a sex difference in the magnitude of light-induced phase shifts and in entrainment of the pacemaker. However, evidence is given that the sex difference in activity onset might also be caused by a sex difference in the relationship of locomotor activity to the pacemaker in intact males and females.


2014 ◽  
Vol 15 (1) ◽  
Author(s):  
Matthias Alexander Zingg ◽  
Mathias Wolfrum ◽  
Christoph Alexander Rüst ◽  
Thomas Rosemann ◽  
Romuald Lepers ◽  
...  

AbstractPurpose. Recent studies have suggested that the age of peak freestyle swimming speed is reached earlier in life in women than in men. However, no study has investigated the age of peak swimming speed in other swimming styles such as butterfly. The aims of the present study were to investigate the age of peak swimming speed in elite male and female butterfly and freestyle swimmers at the national level (Switzerland) and the sex differences in both the age of peak swimming speed and swimming speed for both swimming styles. Methods. Results of the elite Swiss swimmers between 2006 and 2010 were analysed using one-way analysis of variance. Results. In butterfly, women achieved peak swimming speed at 20-21 years in the 50 m, 100 m and 200 m, whereas men reached their fastest swimming speed in the 50 m at 20-21 years and in both the 100 m and 200 m at 18-19 years. In freestyle, women achieved peak swimming speed at 20-21 years for all distances. Men were the fastest at 22-23 years for both the 100 m and 200 m and at 26-27 years for the 50 m. In the butterfly, the sex difference in swimming speed was highest in the 50 m and lowest in the 200 m (14.1% ± 0.2 in the 50 m, 12.6% ± 1.0 in the 100 m and 8.7% ± 1.8 in the 200 m). Additionally, the sex difference in freestyle swimming speed was highest in the 50 m and lowest in the 200 m (16.2% ± 0.5 in the 50 m, 15.9% ± 0.4 in 100 m and 14.9% ± 1.0 in 200 m). Conclusions. These findings suggest that peak swimming speed was achieved earlier in life in men compared with women for the 100 m and 200 m butterfly distances but not in the 50 m butterfly. In freestyle, peak swimming speed was achieved at younger ages in women compared with men. The sex difference in peak swimming speed was lower in the butterfly than in freestyle.


1979 ◽  
Vol 44 (3) ◽  
pp. 719-726 ◽  
Author(s):  
Diane R. Follingstad

This study assessed the differential effects of sex of pressuring confederates and perception of ability on conforming behavior of males and females. Varying male and female sources of the communication to influence subjects' views of their ability was expected to produce less conformity in females receiving the information from a male rather than a female. Data on undergraduates showed 64 females did not conform significantly more than 64 males, but male subjects conformed more in the presence of male confederates while females conformed significantly more when led to believe that males were more accurate on the task. Only the male source influencing females to believe they were superior on the task resulted in significantly less conformity in female subjects. Considering sex differences is essential due to the finding that the sexes responded to different variables present in most conformity experiments. The decrease in conformity produced in females when told by a male that females do better than males has implications for the use of male sources of communication to increase independent behavior of women.


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