The Effects of Asymmetry on Oscillatory Propulsion

Owing to the problems caused by propellers, research has turned to the biological world for inspiration for non-propeller propulsion. Rays were chosen for further study and it was found that a key feature of their swimming is the asymmetric-in-time movements of their pectoral fins. The main goal was to determine whether asymmetric-in-time oscillations produced a larger resultant force. Two flexible fins were used (NACA and biomimetic stiffness profile "BIO"). Asymmetry was defined by the proportion of the time period taken to effect one half-stroke. The experiments showed that at low frequencies, asymmetric oscillation produced greater resultant force and that this force was at an angle to the chord of the fin at rest. At high frequencies, the BIO fin produced lower resultant force when oscillating asymmetrically and the angle of the resultant force was the same as for the symmetric oscillations. There was no difference between the resultant force magnitude or direction produced by the NACA fin at high frequencies. More power was used when oscillating asymmetrically but the force efficiency, the resultant force per watt, was often the same for symmetric and asymmetric oscillations. The trailing edge kinematics of the fins were analysed. Some of the kinematics variables correlated with the resultant force magnitude independently of fin type. The wake structures behind the fins oscillating at two different frequencies were examined. The wakes were geometrically asymmetric behind both fins oscillating asymmetrically at low frequency. At the higher frequency, the wakes behind the asymmetrically oscillating fins were no different to their symmetric counterpartsEThOS - Electronic Theses Online ServiceGBUnited Kingdo

Mechanics and materials in the design of a buckling diaphragm wave energy converter

Not sure what acceptance date was so just used publication date

Comparison of Extension Personnel and Supervisor Perceptions of Communications Activities

Extension is often called the “best-kept secret” having low awareness with the public but high satisfaction with clientele. Extension services nationwide have faced budget cuts, creating a need for the organization to re-evaluate its activities, including how it communicates with its stakeholders. While Extension personnel are the ones who will do most of the communicating, their supervisors impact the personnel’s actions, which means it is important to assess both groups. A survey was conducted with Extension personnel and their supervisors in Mississippi assessing engagement in communications activities and perceptions of those activities, as well as personnel’s preference of professional development activities. Personnel reported higher use, comfort, and importance of more traditional (e.g. making a speech) and written activities (e.g. writing a promotional handout) than media-relations activities (e.g. being interviewed for TV), social media-related activities (e.g. managing a Twitter account), and visual communication activities (e.g. graphic design). Supervisors perceived individual communications activities as less important overall than personnel did, and although supervisor and communication scores for use and comfort/capability were similar for most communication activities, there were noticeable exceptions. Additionally, personnel preferred professional development activities that were hands-on or showing the activities first-hand (e.g. demonstrations and field days). Future research should be expanded to other states, conducted in a case study format to study specific relationships, and involve qualitative components. Extension should ensure clear supervisor-communication dialogue on prioritizing communication activities, provide training on communication activities with low use and comfort, and utilize early innovators who are comfortable using newer communication activities

Vitamin D Association with Renal Health and Filtration in Healthy Individuals Free of Cardiometabolic Diseases: A Pilot Study

The effect of vitamin D (VITD) on bone, muscle, and over health is well know in renal failure and chronic kidney disease (CKD). However, the influence of VITD on renal health and filtration (RHF) in healthy individuals is unclear. Currently, only serum creatinine concentration (sCr) methods are used to assess renal status in health individuals. However, newer biomarkers like serum Cystatin C (CyC) and urine epidermal growth factor (uEGF) show promise in evaluating baseline RHF. The impact of Vitamin D on filtration in healthy individuals of various ages is still unknown. PURPOSE: To determine the impact of VITD on RHF in healthy individuals of middle-aged status. METHODS: Thirty-six participants (n = 22 men; n = 14 women; age 37.6 + 12.4 yr; BF% 19.2 + 7.1%) agreed to participate in the research study. Blood and urine samples were obtained under standardized conditions for all individuals. VITD, CyC, uEGF, urine creatinine (uCr), uCr/uEGF ratio, sCR, and multiple estimates of glomerular filtration rate (eGFR) - modification of diet in renal disease (MDRD), CKD-EPI, CyC equations (CyC only and CyC combined with sCr) were assessed as a whole cohort and grouped (young = 20-39 yrs. (n = 22), older = 40-60 yrs. (n = 14)). Analysis was done using a paired sample t-tests, Pearson Correlation to compare VITD concentrations and markers of RHF. Linear regression analyses was performed to examine the relationship between VITD ability to predict RHF. All analyses were performed using SPSS (v. 28.0.1.1). RESULTS: There was no significant correlations found between VITD and markers of RHF in the entire cohort. Therefore, no predictive model was performed. The younger group showed strong negative correlation between VITD and MDRD (r = -0.575, p = 0.008), and that VITD was able to predict MDRD (R2 = 0.331, p = 0.008). No significant correlation observed in older group. CONCLUSIONS: VITD was correlated and able to predict a marker of RHF in healthy younger individuals, but not in older individuals. Based on the sample size and overall outcomes, continued research is needed to more accurately determine VITD effects on RHF in healthy populations

Barcoding the largest animals on Earth: ongoing challenges and molecular solutions in the taxonomic identification of ancient cetaceans.

Over the last few centuries, many cetacean species have witnessed dramatic global declines due to industrial overharvesting and other anthropogenic influences, and thus are key targets for conservation. Whale bones recovered from archaeological and palaeontological contexts can provide essential baseline information on the past geographical distribution and abundance of species required for developing informed conservation policies. Here we review the challenges with identifying whale bones through traditional anatomical methods, as well as the opportunities provided by new molecular analyses. Through a case study focused on the North Sea, we demonstrate how the utility of this (pre)historic data is currently limited by a lack of accurate taxonomic information for the majority of ancient cetacean remains. We then discuss current opportunities presented by molecular identification methods such as DNA barcoding and collagen peptide mass fingerprinting (zooarchaeology by mass spectrometry), and highlight the importance of molecular identifications in assessing ancient species' distributions through a case study focused on the Mediterranean. We conclude by considering high-throughput molecular approaches such as hybridization capture followed by next-generation sequencing as cost-effective approaches for enhancing the ecological informativeness of these ancient sample sets.This article is part of the themed issue 'From DNA barcodes to biomes'

The Future of Leisure Studies in Research Universities: Administrators\u27 Perspectives

This article summarizes the content of a three-day administrative summit held at Zion Ponderosa Resort in southern Utah in late September 2010. Department chairs, heads, and deans representing 13 universities across North America offering leisure studies doctoral degrees, master\u27s degrees, and undergraduate professional preparation degrees gathered to entertain eight multifaceted questions pertaining to their future. The questions were generated by a Delphi Process, and responses to the questions were recorded and analyzed following the summit by a team of doctoral students and professors from the University of Utah. The article concludes with a brief discussion of an administrator\u27s responsibility in leading leisure studies departments in times of fiscal austerity, and recommending a to-do list to ensure the future of leisure studies in public research universities

Using combined biomolecular methods to explore whale exploitation and social aggregation in hunter–gatherer–fisher society in Tierra del Fuego

Cetaceans were an important food and raw material resource for the South American hunter–gatherer–fisher (HGF) communities of Tierra del Fuego. Historic ethnographic evidence suggests that relatively mobile HGF groups came together in large numbers to exploit carcasses from individual cetacean stranding events. Substantial accumulations of whale bones within shell middens in the Lanashuaia locality of the Beagle Channel suggests that these social aggregation events may also have occurred in pre-historic periods. The difficulty in assigning taxonomic identifications to the fragmentary whale remains, however, made it difficult to explicitly test this hypothesis. Here, we applied two different biomolecular techniques, collagen peptide mass fingerprinting (ZooMS) and ancient mitochondrial DNA analysis to 42 archeological bone fragments from the Lanashuaia locality to provide accurate species identifications. There was a clear correspondence between ZooMS and DNA results, identifying five different cetacean species (Southern bottlenose, blue, humpback, right, and sei whale) as well as human and sea lion remains. The biomolecular results were not conclusively consistent with HGF social aggregation, revealing an unexpectedly diverse range of cetaceans within the Lanashuaia middens. However, the results could not fully refute the hypothesis that cetacean remains can be used as anthropic markers of aggregation events, as the observed species and haplotypes revealed potential shared exploitation of some whale resources between midden sites