1,080 research outputs found

    Colour change and assortment in the western rainbowfish

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    Grouping behaviour is widespread across the animal kingdom, and is known to reduce an individual's risk of predation, for example through predator confusion. Theory predicts that individuals that are different in appearance to the rest of the group are at a greater risk of predation because they are more conspicuous to predators (the ‘oddity’ effect). Thus, animals should choose group mates that are the most similar in appearance to themselves. Another common antipredator tactic is crypsis (camouflage). Fishes are capable of changing colour to match their visual background, but few studies have examined how this might influence shoaling decisions, particularly in the context of the oddity effect. We induced colour pattern changes in a colourful species of freshwater fish, the western rainbowfish, Melanotaenia australis, by maintaining fish in dark and pale aquaria for 2 weeks. Analysis of the proportion of black body pigmentation confirmed that rainbowfish in dark environments developed darker colour patterns than those held in pale environments. We then conducted behavioural observations to determine whether fish subsequently based their shoaling decisions on body coloration. We found that rainbowfish preferred to shoal with similar individuals; fish that had been held in dark aquaria preferred to shoal with other dark fish and fish from pale aquaria preferred other pale fish. Our findings are consistent with the predictions of the oddity effect and demonstrate how morphological colour pattern changes and behavioural decisions interact to mediate antipredator tactics in fish

    Conflict between background matching and social signalling in a colour-changing freshwater fish

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    The ability to change coloration allows animals to modify their patterning to suit a specific function. Many freshwater fishes, for example, can appear cryptic by altering the dispersion of melanin pigment in the skin to match the visual background. However, melanin-based pigments are also used to signal dominance among competing males; thus colour change for background matching may conflict with colour change for social status signalling. We used a colour-changing freshwater fish to investigate whether colour change for background matching influenced aggressive interactions between rival males. Subordinate males that had recently darkened their skin for background matching received heightened aggression from dominant males, relative to males whose coloration had not changed. We then determined whether the social status of a rival male, the focal male's previous social status, and his previous skin coloration, affected a male's ability to change colour for background matching. Social status influenced skin darkening in the first social encounter, with dominant males darkening more than subordinate males, but there was no effect of social status on colour change in the second social encounter. We also found that the extent of skin colour change (by both dominant and subordinate males) was dependent on previous skin coloration, with dark males displaying a smaller change in coloration than pale males. Our findings suggest that skin darkening for background matching imposes a significant social cost on subordinate males in terms of increased aggression. We also suggest that the use of melanin-based signals during social encounters can impede subsequent changes in skin coloration for other functions, such as skin darkening for background matching

    Bone Turnover Response to Acute Exercise with Varying Impact Levels: A preliminary investigation

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    International Journal of Exercise Science 8(2): 154-163, 2015. The purpose of this investigation was to determine if there are changes in metabolic markers of bone turnover within the 24-hour period following an acute bout of jogging or water exercise. Ten healthy females (22-30 yr.) underwent three trials with different ground impact forces: jogging, water aerobics and control. For the jogging and water aerobics trials, subjects exercised for 30 min at 60-70% of predicted maximal heart rate in addition to a 5 min warm up and cool down. For the control trial, subjects rested for 40 min, i.e., the total exercise time of the other trials. For each trial, blood samples were collected pre, immediately post, 1 hr. post, and 24 hr. post exercise. All samples were analyzed for levels of osteocalcin, bone specific alkaline phosphatase and cross-linked N telopeptides. A repeated-measure ANOVA was used to determine if there were differences between impact levels or over time. There were no significant differences over time, or between impact levels of exercise. Therefore these results indicate that healthy young women demonstrate no changes in bone turnover within 24 hr. of a single bout of exercise. Due to biochemical markers of bone turnover responding in a similar manner regardless of activity type, these findings suggest that water aerobics can be seen as a beneficial form of exercise for maintenance of bone density

    Organic Farmers as Victims of lnjurious Practices by Biogenetic Corporations

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    The relationship between anticompetitive practices by large biotechnology corporations and their victimizing effects on organic farmers, with reference to genetically engineered and altered seeds in the United States market, is examined. The sample was derived from individuals associated with the organic farming industry. The total sample populace was taken from two cumulative lists of organic farmers, organic certification agencies, and organic food producers. One hundred individuals were mailed questionnaires. Of the fifty-four percent that returned the surveys, one hundred percent feel there are not sufficient regulations on genetic engineering nor have sufficient precautions been taken. Issues of labeling safety, and environmental damage are discussed

    Geography and Location Are the Primary Drivers of Office Microbiome Composition.

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    In the United States, humans spend the majority of their time indoors, where they are exposed to the microbiome of the built environment (BE) they inhabit. Despite the ubiquity of microbes in BEs and their potential impacts on health and building materials, basic questions about the microbiology of these environments remain unanswered. We present a study on the impacts of geography, material type, human interaction, location in a room, seasonal variation, and indoor and microenvironmental parameters on bacterial communities in offices. Our data elucidate several important features of microbial communities in BEs. First, under normal office environmental conditions, bacterial communities do not differ on the basis of surface material (e.g., ceiling tile or carpet) but do differ on the basis of the location in a room (e.g., ceiling or floor), two features that are often conflated but that we are able to separate here. We suspect that previous work showing differences in bacterial composition with surface material was likely detecting differences based on different usage patterns. Next, we find that offices have city-specific bacterial communities, such that we can accurately predict which city an office microbiome sample is derived from, but office-specific bacterial communities are less apparent. This differs from previous work, which has suggested office-specific compositions of bacterial communities. We again suspect that the difference from prior work arises from different usage patterns. As has been previously shown, we observe that human skin contributes heavily to the composition of BE surfaces. IMPORTANCE Our study highlights several points that should impact the design of future studies of the microbiology of BEs. First, projects tracking changes in BE bacterial communities should focus sampling efforts on surveying different locations in offices and in different cities but not necessarily different materials or different offices in the same city. Next, disturbance due to repeated sampling, though detectable, is small compared to that due to other variables, opening up a range of longitudinal study designs in the BE. Next, studies requiring more samples than can be sequenced on a single sequencing run (which is increasingly common) must control for run effects by including some of the same samples in all of the sequencing runs as technical replicates. Finally, detailed tracking of indoor and material environment covariates is likely not essential for BE microbiome studies, as the normal range of indoor environmental conditions is likely not large enough to impact bacterial communities

    Disruptive Momentum: The Value of Implementing Best Practices in Health Research Postdoctoral Mentorship

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    COVID-19 called attention to the challenges postdoctoral fellows in health research face when they have times of prolonged disruption or changes in work conditions; this disruption revealed key insights on how mentors, fellows, and their institutions can work together to ensure training continuity. To prepare strong scientists, postdoctoral fellowships need mentoring, training, and networking opportunities to enhance fellows’ professional and skill development. In this article we outline potential solutions to minimize the impact of disruptions while promoting adaptable postdoctoral fellowship experiences by addressing how mentors and fellows alike can intervene on three key aspects of fellowships in health research: mentorship, training, and networking

    Association patterns and foraging behaviour in natural and artificial guppy shoals

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    Animal groups are often nonrandom assemblages of individuals that tend to be assorted by factors such as sex, body size, relatedness and familiarity. Laboratory studies using fish have shown that familiarity among shoal members confers a number of benefits to individuals, such as increased foraging success. However, it is unclear whether fish in natural shoals obtain these benefits through association with familiars. We investigated whether naturally occurring shoals of guppies, Poecilia reticulata, are more adept at learning a novel foraging task than artificial (in which we selected shoal members randomly) shoals. We used social network analysis to compare the structures of natural and artificial shoals and examined whether shoal organization predicts patterns of foraging behaviour. Fish in natural shoals benefited from increased success in the novel foraging task compared with fish in artificial shoals. Individuals in natural shoals showed a reduced latency to approach the novel feeder, followed more and formed smaller subgroups compared to artificial shoals. Our findings show that fish in natural shoals do gain foraging benefits and that this may be facilitated by a reduced perception of risk among familiarized individuals and/or enhanced social learning mediated by following other individuals and small group sizes. Although the structure of shoals was stable over time, we found no direct relationship between shoal social structure and patterns of foraging behaviour

    Motherhood and Me (Mom-Me): The Development of an Acceptance-Based Group for Women with Postpartum Mood and Anxiety Symptoms

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    Untreated postpartum mood and anxiety disorders (PMADs) place women and their families at risk for negative biopsychosocial sequelae. Innovative and tailored treatments are needed to address potential disruptions in maternal functioning. Third-wave cognitive-behavioral approaches, including acceptance and commitment therapy (ACT) and dialectical behavioral therapy (DBT), hold promise for optimizing functioning given the focus on values-based living, rather than symptom reduction. Purpose: The purpose of this paper is to describe the development of an innovative psychotherapy group for women with symptoms of PMADs. Methods: This seven-session group, Motherhood and Me (Mom-Me), includes selected skills training from ACT, DBT, and Emotion-Centered Problem-Solving Therapy. Results: Mom-Me group sessions are described, and an outline of key information (session goals, content, and homework assignments) is provided to facilitate practical implementation. Conclusion: In line with third-wave approaches, this group was developed to enhance maternal functioning, which, in turn, may help women cope with psychological distress during the transition to motherhood

    Alcohol Use and Trauma Exposure Among Male and Female Veterans Before, During, and After Military Service

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    Background: The present study examined lifespan and combat-related trauma exposure as predictors of alcohol use among male and female veterans. Posttraumatic stress and depressive symptoms were examined as mediators of the effects of trauma exposure on alcohol use. Methods: Data were examined from 1825 (1450 male, 375 female) veterans and active duty service members who took part in a multi-site research study conducted through the Department of Veterans Affairs Mid-Atlantic Mental Illness Research, Education and Clinical Center (VISN 6 MIRECC). Results: For both men and women, depressive symptoms significantly mediated the effects of non-combat trauma exposure experienced before, during and after the military, as well as combat-exposure, on alcohol use. With posttraumatic stress symptoms, the models for men and women differed. For men, the effects of non-combat trauma exposure during and after military service, and combat exposure, on alcohol use were mediated by PTSD symptoms; however, for women, PTSD symptoms did not mediate these relationships. Conclusion: Findings are discussed in the context of potential gender differences in response to trauma such as use of alcohol to cope with traumatic events
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