406 research outputs found
Identities and Motives of Naturalist Development Program Attendees and Their Relation to Professional Careers
In recent years, there has been much concern over the decline of biologists who actually identify themselves to be naturalists, which negatively impacts the field of conservation and the study of biology as a whole. This could result in a decrease in individuals who participate in naturalist-like activities, such as informal environmental education and environmental volunteerism. The purpose of my study was to determine what discourse identities were held by naturalist development program participants, how these discourse identities related to their volunteer motives in environmental settings, and how discourse identity related to professional careers. I defined identity through the lens of discourse-identity, which describes a person’s identity as being conveyed through that individual’s communication and actions. I conducted individual interviews or used an online questionnaire to ask questions to naturalist development program attendees about their workshop experience, relationship with nature, volunteer motives and activities, as well as professional career or career aspiration. Volunteer motives were quantitatively measured in both types of program participants using the published Volunteer Motivation Questionnaire. Overall, I found the 100 study participants had six discourse identities: naturalist (n = 27), aspiring naturalist (n = 32), nature steward (n = 5), outreach volunteer (n = 6), casual nature observer (n = 22), and recreational nature user (n = 8). Naturalist development programs should focus on developing more naturalist-like discourse identities in their participants to help encourage participation in naturalist activities. Volunteer motives were ranked by importance to participants in the following order: helping the environment, learning, user, project organization, values and esteem, social, and career. The majority of Master Naturalist Program study participants that stated a career were in non-STEM careers; however, the majority of individuals with a naturalist or aspiring naturalist discourse identity did have careers in STEM. The OUTSIDE NDP study participants all expressed their intention to pursue STEM careers. By focusing on hands-on outdoor professional development, the development of naturalist discourse identities, and on developing the volunteer motives participants’ value, more individuals could be retained to assist with naturalist activities
Burrowing Behavior of the Fiddler Crab \u3ci\u3eUca panacea\u3c/i\u3e in Relation to Food Availability
Much of fiddler crab behavior is regulated by the tides and centers around their burrows. Field and laboratory studies were conducted to assess the effect of food availability on burrowing in the Gulf coast fiddler crab, Vea panacea. In the field, crabs were observed for droving behavior through visual observations; evidence for this behavior was assessed further by determining sediment organic content. Although the organic content did increase significantly as distance increased from the edge of the water, fiddler crabs did not exhibit droving behavior at my study site. Field burrows were cast and measured for depth, diameter and volume to determine if burrow size changed as distance increased from the water. Burrow size did not differ significantly based on distance from the water. In the laboratory, males and females were randomly assigned to either low food (0.2% sediment organic content) or high food (1.5% sediment organic content) treatments for a period of 12 d; plaster casts of burrows were measured as above. When male and female results were pooled, there was a significant difference between low and high food treatments in burrow depth, diameter and volume. When crabs were grouped by carapace width into small (8.0-11.0 mm) and large (11.1-15.0 mm) size classes, diameter was the only burrow parameter that differed significantly. Food availability did affect some aspects of fiddler crab burrowing behavior; understanding what affects burrowing may shed light on fiddler crab importance and impact on ecosystem composition and processes
Adaptation of NASA technology for the optimization of orthopedic knee implants
The NASA technology originally developed for the optimization of composite structures (engine blades) is adapted and applied to the optimization of orthopedic knee implants. A method is developed enabling the tailoring of the implant for optimal interaction with the environment of the tibia. The shape of the implant components are optimized, such that the stresses in the bone are favorably controlled to minimize bone degradation and prevent failures. A pilot tailoring system is developed and the feasibility of the concept is elevated. The optimization system is expected to provide the means for improving knee prosthesis and individual implant tailoring for each patient
Shape optimization of tibial prosthesis components
NASA technology and optimal design methodologies originally developed for the optimization of composite structures (engine blades) are adapted and applied to the optimization of orthopaedic knee implants. A method is developed enabling the shape tailoring of the tibial components of a total knee replacement implant for optimal interaction within the environment of the tibia. The shape of the implant components are optimized such that the stresses in the bone are favorably controlled to minimize bone degradation, to improve the mechanical integrity of the implant/interface/bone system, and to prevent failures of the implant components. A pilot tailoring system is developed and the feasibility of the concept is demonstrated and evaluated. The methodology and evolution of the existing aerospace technology from which this pilot optimization code was developed is also presented and discussed. Both symmetric and unsymmetric in-plane loading conditions are investigated. The results of the optimization process indicate a trend toward wider and tapered posts as well as thicker backing trays. Unique component geometries were obtained for the different load cases
Essential fatty acids composition and oxidative stability of frozen minced carp meat
This study aimed to introduce minced common carp (Cyprinus caprio L.) meat as a nutritional valuable by-product from carp filleting. This research was focused on fatty acid composition and considered its sensitivity to oxidation during frozen storage (-20 degrees C). Additionally, copper chloride was used to magnify possible oxidation reactions. A better understanding of minced carp meat quality and deterioration during frozen storage could help to promote the usage of this underestimated by-product. The utilization of this by-product for human consumption could be a useful way to increase the carp aquaculture economy and sustainability. The fatty acid profile showed a favorable content of essential fatty acids, as well as a beneficial ratio of omega-3/omega-6 polyunsaturated fatty acids. Furthermore, during 4 months of frozen storage (-20 degrees C), no significant changes were detected in fatty acid composition. Negligible changes were observed in the oxidation of lipids and proteins. The nutritional value and storage stability of minced carp meat was shown
Crystal Structure of Orthorhombic {bis-[(pyridin-2-yl)methyl](3,5,5,5-tetrachloropentyl)amine-Îş\u3csup\u3e3\u3c/sup\u3e\u3cem\u3eN,N\u27,N\u27\u27\u3c/em\u3e}chloridocopper(II) Perchlorate
In the title compound, [CuCl(C17H19Cl4N3)]ClO4, the CuII ion adopts a distorted square-planar geometry defined by one chloride ligand and the three nitroÂgen atoms from the bisÂ[(pyridin-2-yl)methÂyl](3,5,5,5-tetraÂchloroÂpentÂyl)amine ligand. The perchlorate counter-ion is disordered over three sets of sites with refined occupancies 0.0634 (17), 0.221 (16) and 0.145 (7). In addition, the hetero-scorpionate arm of the bisÂ[(pyridin-2-yl)methÂyl](3,5,5,5-tetraÂchloroÂpentÂyl)amine ligand is disordered over two sets of sites with refined occupancies 0.839 (2) and 0.161 (2). In the crystal, weak Cuâ‹ŻCl interÂactions between symmetry-related molÂecules create a dimerization with a chloride occupying the apical position of the square-pyramidal geometry typical of many copper(II) chloride hetero-scorpionate complexes
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Weight and dimensional stability of three low-density core materials
This report is one of a series issued in cooperation with the Army-Navy-Civil Committee on Aircraft Design Criteria under the supervision of the Aeronautical Board
Novel insights into the cardio-protective effects of FGF21 in lean and obese rat hearts
Aims: Fibroblast growth factor 21 (FGF21) is a hepatic metabolic regulator with pleotropic actions. Its plasma concentrations are increased in obesity and diabetes; states associated with an increased incidence of cardiovascular disease. We therefore investigated the direct effect of FGF21 on cardio-protection in obese and lean hearts in response to ischemia.
Methods and Results: FGF21, FGF21-receptor 1 (FGFR1) and beta-Klotho (βKlotho) were expressed in rodent, human hearts and primary rat cardiomyocytes. Cardiac FGF21 was expressed and secreted (real time RT-PCR/western blot and ELISA) in an autocrine-paracrine manner, in response to obesity and hypoxia, involving FGFR1-βKlotho components. Cardiac-FGF21 expression and secretion were increased in response to global ischemia. In contrast βKlotho was reduced in obese hearts. In isolated adult rat cardiomyocytes, FGF21 activated PI3K/Akt (phosphatidylinositol 3-kinase/Akt), ERK1/2(extracellular signal-regulated kinase) and AMPK (AMP-activated protein kinase) pathways. In Langendorff perfused rat [adult male wild-type wistar] hearts, FGF21 administration induced significant cardio-protection and restoration of function following global ischemia. Inhibition of PI3K/Akt, AMPK, ERK1/2 and ROR-α (retinoic-acid receptor alpha) pathway led to significant decrease of FGF21 induced cardio-protection and restoration of cardiac function in response to global ischemia. More importantly, this cardio-protective response induced by FGF21 was reduced in obesity, although the cardiac expression profiles and circulating FGF21 levels were increased.
Conclusion: In an ex vivo Langendorff system, we show that FGF21 induced cardiac protection and restoration of cardiac function involving autocrine-paracrine pathways, with reduced effect in obesity. Collectively, our findings provide novel insights into FGF21-induced cardiac effects in obesity and ischemia
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