Analysis of Forest Structure Among Management Types at Land Between the Lakes, Kentucky

Fire is a dynamic disturbance that once created and maintained the oak savannas and oak forests of the Southeast. These forests are characterized by open structures with herbaceous understories, which provide significant habitat and food for native wildlife species. In the absence of fire, canopies close and fire-intolerant, shade-tolerant species begin to crowd the understory and midstory. This process, known as mesophication, occurs when increasingly cool, damp, and shaded conditions create a less flammable fuel bed and improve conditions for mesophytic species creating deteriorating conditions for shade-intolerant, fire-adapted species such as oaks (Quercus spp.). The use of prescribed fire is increasingly being used as a management tool to combat the changes in forest structure that result from mesophication. We used forest structure data from the overstory, midstory, understory, and forest floor at 20 sites in Land Between the Lakes National Recreation Area (LBL) to test for variance among 4 types of forest management. The management types we studied included (1) areas not subject to any prescribed burning or thinning methods, (2) grasslands, (3) areas burned within 6 months of the study, and (4) areas burned more than 6 months prior to our study. We found the least amount of variation among management types in the midstory, and the greatest variation on the forest floor. We also found that areas that had not been burned within 6 months of the study were most similar to unmanaged areas for all forest strata except the overstory. Forest structure data such as this can provide feedback on current management practices and provide a scientific basis for future management decisions

Sound power and vibration levels for two different piano soundboards

This paper compares the sound power and vibration levels for two different soundboards for upright pianos. One of them is made of laminated spruce and the other of solid spruce (tone-wood). These differ also in the number of ribs and manufacturing procedure. The methodology used is defined in two major steps: (i) acoustic power due to a unit force is obtained reciprocally by measuring the acceleration response of the piano soundboards when excited by acoustic waves in reverberant field; (ii) impact tests are adopted to measure driving point and spatially-averaged mean-square transfer mobility. The results show that, in the mid-high frequency range, the soundboard made of solid spruce has a greater vibrational and acoustic response than the laminated soundboard. The effect of string tension is also addressed, showing that is only relevant at low frequencies

Political Participation in Physical Therapy: Attitudes and Perceptions Across the Practice Spectrum

BACKGROUND AND PURPOSE: Political participation has been identified by the APTA as one way to engage in social responsibility. Among the traditional professions, including health care, political participation is encouraged as a professional duty to society through professional codes of ethics and educational preparation. Currently, no research exists on PT professionals’ attitudes regarding political participation. The purpose of this study was to explore physical therapists’ perceptions and experiences surrounding political participation.METHODS:A phenomenological qualitative approach was employed to gather data from 4 semi-structured focus groups regarding physical therapists’ perceptions surrounding political participation. Participants included 22 physical therapists and 1 physical therapist assistant from the acute, outpatient, and inpatient rehabilitation practice settings. Audio data from each focus group was transcribed, returned to subjects for verification, and independently coded and themed by the researchers. Methods such as purposive sampling, member checks, peer debriefings and triangulation were used to support the dependability and trustworthiness of the study.RESULTS:Multiple themes emerged within four categories. The “individual” category included one’s views about political participation, specifically as a professional role. The behaviors and outcomes” category included the actions individuals engage in when participating politically and the achievements gained through said participation. The “motivators and barriers” category described the influences on the behaviors, either encouraging or discouraging political participation. The aforementioned categories exist within the larger context of the final category, the physical therapy profession/APTA and practice setting.”CONCLUSION:Results of this study indicate that PTs perceptions of political participation emerge from a combination of personal and experiential elements. PTs recognized the importance of political activity, but saw it as more a role of the APTA rather than the individual. Participants had difficulty articulating the achievements of the APTA in the political arena and expressed frustration with the communication of political advocacy information. For political participation among PTs to increase, exemplary behaviors should be modeled in the school and work places, motivating factors should be increased and barriers decreased. Furthermore, there must be a direct and explicit call for physical therapists to live up to the standards charged by their profession

Analytical approach to viscous fingering in a cylindrical Hele-Shaw cell

We report analytical results for the development of the viscous fingering instability in a cylindrical Hele-Shaw cell of radius a and thickness b. We derive a generalized version of Darcy's law in such cylindrical background, and find it recovers the usual Darcy's law for flow in flat, rectangular cells, with corrections of higher order in b/a. We focus our interest on the influence of cell's radius of curvature on the instability characteristics. Linear and slightly nonlinear flow regimes are studied through a mode-coupling analysis. Our analytical results reveal that linear growth rates and finger competition are inhibited for increasingly larger radius of curvature. The absence of tip-splitting events in cylindrical cells is also discussed.Comment: 14 pages, 3 ps figures, Revte

Study of the Current-Phase Relationship of Josephson Junctions With Insulating and Metallic Barriers

Josephson Junctions have been around for over 60 years and are used in a wide variety of applications, from voltage standards to SQUID magnetometers. Although the quantization of flux in these junctions has been known from the start, the exact relationship between applied current and the quantum mechanical phase difference across a junction (C&Phi;R) has not. It is usually assumed to be sinusoidal, but this is not always the case. The materials of the electrodes and the properties of the barrier influence this relationship. One reason for the sinusoidal assumption is that the measurement of C&Phi;R is not straightforward. However, a complete understanding of the C&Phi;R and its applications to junction behavior is necessary for accurate modeling and designing circuits for optimal operation. In this thesis, I will investigate, through measurements and simulations, a number of techniques to both measure the effects of non-sinusoidal C&Phi;R and derive the C&Phi;Rs. I will also use these technique to map out C&Phi;Rs in a number of different material barriers. Of particular interest is Aluminum oxide, a standard barrier material, and doped amorphous Silicon, which has a wide range of properties depending on the doping. The measured barriers had a range of C&Phi;Rs, from purely sinusoidal to highly skewed.</p

Yang-Lee and Fisher Zeros of Multisite Interaction Ising Models on the Cayley-type Lattices

A general analytical formula for recurrence relations of multisite interaction Ising models in an external magnetic field on the Cayley-type lattices is derived. Using the theory of complex analytical dynamics on the Riemann sphere, a numerical algorithm to obtain Yang-Lee and Fisher zeros of the models is developed. It is shown that the sets of Yang-Lee and Fisher zeros are almost always fractals, that could be associated with Mandelbrot-like sets on the complex magnetic field and temperature planes respectively.Comment: 9 pages, 3 figures; with minor correction

The Effects of Extravehicular Activity (EVA) Glove Pressure on Tactility

The purpose of the current study was to quantify finger tactility, while wearing a Phase VI Extravehicular Activity (EVA) glove. Subjects were fully suited in an Extravehicular Mobility Unit (EMU) suit. Data was collected under three conditions: bare-handed, gloved at 0 psi, and gloved at 4.3 psi. In order to test tactility, a series of 30 tactile stimuli (bumps) were created that varied in both height and width. With the hand obscured, subjects applied pressure to each bump until detected tactilely. The amount of force needed to detect each bump was recorded using load cells located under a force-plate. The amount of force needed to detect a bump was positively related to width, but inversely related to height. In addition, as the psi of the glove increased, more force was needed to detect the bump. In terms of application, it was possible to determine the optimal width and height a bump needs to be for a specific amount of force applied for tactility

Student Ensemble: Symphony Orchestra and Concerto Aria Concert

Center for the Performing ArtsApril 25, 2013Thursday Evening8:00 p.m