1,432 research outputs found
Ontogenetic changes in the thermal and buoyant properties of Atlantic Bottlenose Dolphin (Tursiops truncatus) blubber
The thermal properties of cetacean blubber are influenced by its lipid content and thickness. In Atlantic bottlenose dolphins (Tursiops truncatus), both these features vary across ontogeny and with reproductive and nutritional status and, thus, may result in ontogenetic differences in blubberâs insulative quality. Lipid and water contents, and thermal conductivity and thermal insulation values of Atlantic bottlenose dolphin blubber were measured across fetal through adult life history categories (n = 36), and in pregnant females (n=4) and emaciated animals (n = 5). The thermal conductivities of deep and superficial blubber layers were also measured.
Thermal conductivity varied significantly across ontogeny. Fetal through sub-adult life history categories had significantly lower mean thermal conductivity values (0.11 to 0.13 ± 0.01 W/m°C) than adults (0.18 ± 0.02 W/m°C). The conductivity of blubber from pregnant females was similar to non-adult categories, while that of emaciated animals was significantly higher than all other categories. The conductivity of superficial blubber was 37% higher than that of deep blubber. Across life history categories, the conductivity of superficial blubber was similar, while that of deep blubber was significantly greater in emaciated animals.
Thermal insulation varied significantly across life history categories. Sub-adults and pregnant females had the highest insulation while fetuses and emaciated animals had the lowest insulation across life history categories. The insulation of neonates and juveniles was similar to that of adult dolphins. Heat flux measurements at the deep blubber surface were significantly higher than that at the superficial surface and this difference in heat flux was significantly correlated with blubber thickness. This pattern was not observed in control materials, polystyrene foam and white pine wood.
In nutritionally dependant life history categories, changes in blubberâs thermal insulation resulted from changes in blubber thickness (i.e. quantity) and not thermal conductivity (i.e. quality). Conversely, in nutritionally independent animals, blubber quantity remained stable while blubber quality varied. Differences in conductivity through the blubber depth support the characterization of deep blubber as more insulative and metabolically active layer of lipid deposition and mobilization. Finally, blubberâs composition and its ability to absorb heat suggest that it likely is a phase change material. Blubber is the hypertrophied hypodermis of cetaceans composed primarily of adipocytes and structural fibers. Because the density of lipid is less than that of seawater, blubber has the potential to contribute to positive buoyancy. The blubber of Atlantic bottlenose dolphins (Tursiops truncatus) varies both in thickness and lipid content across ontogeny and with reproductive and nutritional status. This variation in blubberâs quantity and quality may significantly influence its contribution to buoyancy. To measure blubberâs buoyant force, its density was measured volumetrically and its volume was calculated at two body sites (trunk and tailstock), across an ontogenetic series of bottlenose dolphins and in pregnant females and emaciated animals. Lipid and water content were measured to correlate compositional changes with differences in blubberâs buoyant force.
The density of blubber from the trunk region (mean ± standard error = 1043.1 ± 13.18 kg/m3) was similar to that of the tailstock (mean = 1077.1 ± 24.17 kg/m3) and these were not significantly different than the density of seawater (1026 kg/m3). Density in these regions was also similar between life history categories. Blubber volume in the trunk and tailstock regions increased over two orders of magnitude between fetuses and adults. The buoyant force of trunk blubber was similar across categories (mean = â0.91 ± 8.85N) and was not significantly different from neutral buoyancy (0N). Trunk blubber of emaciated animals was twelve times more negatively buoyant than that of adults. The buoyant force of tailstock blubber was similar between life history categories (mean = â0.30 ± 1.83 N). For groups with a sufficient sample size for statistical analyses (fetus, neonate, and juvenile), mean total buoyant force of blubber was 0.61 ± 7.45 N and was not significantly different between these groups.
Despite significant differences in lipid content and volume across life history categories, blubberâs contribution to buoyancy remained neutral. Because this body compartment is nearly 25% of total body mass, it may be essential for this tissue to be neutrally buoyant. Pregnancy and emaciation can significantly influence blubberâs contribution to buoyancy and may impose additional locomotor costs associated with overcoming a positive or negative vertical force.
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Clusters of problem behaviors in adolescents
This study was designed to examine clusters of problem behaviors in a sample from the National Longitudinal Study of Adolescent Health at two time points. The technique employed was a person-oriented approach, cluster analysis. Three clusters were identified, a normal behaviors cluster, a problem behaviors cluster, and a deviant behaviors cluster. The clusters were tested for stability and for their relationships to the demographic variables gender, race, age, and socioeconomic status. The mean values for most of the problem behaviors in the problem behaviors cluster were higher than for those in the normal behaviors cluster and lower than for those in the deviant behaviors cluster. Selling drugs and weapon use distinguished the deviant behaviors cluster from the other two. Different interventions probably will be required to address the needs of those in each of the different clusters
Recognizing our power: Honoring the accomplishments of scholars
Many of us have a complicated relationship with awards. However, receiving a reward can be important evidence of a scholarâs contribution when seeking grants to fund important work, promotion, and/or tenure. Awards also may help disseminate that contribution
Using a System of Care framework for the mental health treatment of children and adolescents
Advanced practice psychiatric and mental health nurses recognize the need to provide holistic, culturally competent and family-involved care to children with mental health problems. Yet frequently, other key aspects of the best care are overlooked. System of Care not only promotes holistic, culturally competent, child- and family-centered, and community-based care, but also promotes comprehensive âwraparoundâ services to families. Further, System of Care encourages individualized care provided in the least restrictive setting by an interdisciplinary group. This article presents key principles of System of Care, and the rationale for their use in all mental health care for children. It also includes examples of how the model has resulted in positive outcomes with clients and their families
A smartphone application to educate undergraduate nursing students about providing care for infant airway obstruction
Purpose: This study had two aims: (a) to develop a smartphone-based application and (b) to evaluate the effectiveness of the application by measuring nursing students' knowledge, skills, and confidence in simulated performance when providing that care.Design: We conducted a randomized trial using a pre- and post-test design at a university in Korea. Seventy-three junior nursing students participated.Methods: A smartphone-based app using a video was developed for the experimental group and one time lecture-based education was designed for the control group. We provided the app and information about its use to the experimental group, and we encouraged its use. We provided classroom instruction to the control group. Then, learning outcomes were evaluated. Results: The smartphone-based education group showed significantly higher scores on skills (t = 4.774, p Conclusion: This study suggests that smartphone-based education may be an effective method to use in nursing education related to teaching infant airway obstruction
A Common Language Is So Basic!
It seems obvious that a person seeking care of any type should have a caregiver who speaks that person's language. Unfortunately, that does not always happen in the mono-lingual US, where a sizable minority, more than 8.5% of those aged 5 years and older, speak English âless than very wellâ (U.S. Census Bureau, 2009). In eight states, 10â20% of the population fall into this category, making it even more challenging for them to find a caregiver with whom they can communicate. Nursing care, especially that associated with the provision of mental health services, centers on conversation. Language barriers can compromise such care and pose a risk to patient health
Assuring the integrity of the family: being the father of a very low birth weight infant
Aim. The purpose of this study was to explore the paternal role of fathers of very low birth weight infants during their first year of life.Background. Following birth, very low birth weight infants often require extended hospitalisation and long-term care. The birth experience and the infantâs hospitalisation often overwhelm parents and may hinder the development of their parental roles. The father is known to be an important supporting figure for the mother, but most studies in Taiwan have focussed on mothers.Design. A qualitative design using a grounded theory approach was employed in this study.Methods. In-depth interviews were conducted with a purposive sample of fathers during home visits. Each father was interviewed twice at one to three months and seven to nine months after his very low birth weight infantâs discharge from the hospital. Data were analysed using constant comparison and repeated verification.Results. Twelve fathers were included in the study. During the first year of life of their very low birth weight infants, the fathers experienced âprotecting the wifeâbaby dyadâ, âconcentrating on the childâs health and growthâ, and âpossessing a complete familyâ. Subcategories within each major category also emerged.Conclusion. In this study, Taiwanese fathers of very low birth weight infants learned different and broader dimensions of the paternal role and continually made adjustments to assure their familyâs integrity.Relevance to clinical practice. These findings can help nurses understand paternal perceptions and behaviours related to having a very low birth weight infant and in turn help fathers adjust to their role
Take the shot: Message from the president - Recipients of the 2015 SNRS annual awards
The Southern Nursing Research Society offers a number of annual award opportunities to its members. The 2015 awards were presented at the annual meeting in Tampa, Florida in February. This year Elizabeth J. Corwin received the Distinguished Researcher Award; Ann L. Horgas received the Mid-Career Researcher award; Jeanne Alhusen received the Early Science Investigator Award; Jane Dimmitt Champion received the Research in Minority Health Award; and Karen Rice was given the Clinical Researcher Award
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