Modeling the spatial and temporal dynamics of coastal marsh birds

Wetland birds are likely to be influenced by habitat at multiple spatial scales, yet few studies have investigated bird responses at both broad and fine scales. Northern Gulf Coast marshes are dynamic ecosystems, and they provide an ideal place to examine habitat across spatial and temporal scales. My research focused on the secretive marsh bird guild (i.e. bitterns, rails, gallinules, grebes) with an emphasis on the king rail (Rallus elegans), a species of high conservation concern. My objectives were to investigate the wetland bird-environment relationship across scales, and to model annual changes in bird distribution. Study sites were in the fresh and intermediate (oligohaline) marshes of the Chenier Plain coastal region of southwest Louisiana and southeast Texas. I captured king rails for a two year radio telemetry study, and conducted point count surveys of marsh birds from March to mid-June of 2009-2011 using call-back methods to elicit responses. I visited each point six times per year, and \u3e100 points were surveyed each year (n=304). Localized, field-based measures (e.g. water depth), management, and broad marsh types were related to bird abundance, and species distribution models were developed for four species based on Landsat satellite imagery. Home ranges of king rails varied from 0.8-32.8 ha (n=22), rails selected for open water, and smaller home ranges were associated with greater open water within the home range (20-30%). Point counts showed fine-scale habitat models, usually incorporating water depth, were improved with the addition of broad-scale marsh type and management, classified as permanently impounded, drawdown, or unmanaged. For 12 of 13 species, a multi-scale model was better than any single spatial scale. Species distribution models showed satellite-based measures of habitat corresponded well to marsh birds as they explained 37-79% of the variation in abundance. Temporary water was the most important variable, and species\u27 models were distinct for fresh and intermediate marshes. The spatial distribution of birds varied greatly among years, especially with migratory birds in the highly variable fresh marsh. Overall, marsh birds responded to the environment at a variety of spatial scales, and satellite-based distribution models showed broad-scale patterns and dynamic distributions among years

Term Context Models for Information Retrieval

At their heart, most if not all information retrieval models utilize some form of term frequency. The notion is that the more often a query term occurs in a document, the more likely it is that document meets an information need. We examine an alternative. We propose a model which assesses the presence of a term in a document not by looking at the actual occurrence of that term, but by a set of nonindependent supporting terms, i.e. context. This yields a weighting for terms in documents which is different from and complementary to tf-based methods, and is beneficial for retrieval

Effect of a prior stretch on the aging response of an Al-Cu-Li-Ag-Mg-Zr alloy

Recently, a family of Al-Cu-Li alloys containing minor amounts of Ag, Mg, and Zr and having desirable combinations of strength and toughness were developed. The Weldalite (trademark) alloys exhibit a unique characteristic in that with or without a prior stretch, they obtain significant strength-ductility combinations upon natural and artificial aging. The ultra-high strength (approximately 690 MPa yield strength) in the peak-aged tempers (T6 and T8) were primarily attributed to the extremely fine T(sub 1) (Al2CuLi) or T(sub 1)-type precipitates that occur in these alloys during artificial aging, whereas the significant natural aging response observed is attributed to strengthening from delta prime (Al3Li) and GP zones. In recent work, the aging behavior of an Al-Cu-Li-Ag-Mg alloy without a prior stretch was followed microstructurally from the T4 to the T6 condition. Commercial extrusions, rolled plates, and sheets of Al-Cu-Li alloys are typically subjected to a stretching operation before artificial aging to straighten the extrusions and, more importantly, introduce dislocations to simulate precipitation of strengthening phases such as T(sub 1) by providing relatively low-energy nucleation sites. The goals of this study are to examine the microstructure that evolves during aging of an alloy that was stretch after solution treatment and to compare the observations with those for the unstretched alloy

High resolution electron microscopy study of a high Cu variant of Weldalite (tm) 049 and a high strength Al-Cu-Ag-Mg-Zr alloy

Weldalite (trademark) 049 is an Al-Cu-Li-Ag-Mg alloy that is strengthened in artificially aged tempers primarily by very thin plate-like precipitates lying on the set of (111) matrix planes. This precipitate might be expected to be the T(sub 1) phase, Al2CuLi, which has been observed in Al-Cu-Li alloys. However, in several ways this precipitate is similar to the omega phase which also appears as the set of (111) planes plates and is found in Al-Cu-Ag-Mg alloys. The study was undertaken to identify the set of (111) planes precipitate or precipitates in Weldalite (trademark) 049 in the T8 (stretched and artificially aged) temper, and to determine whether T(sub 1), omega, or some other phase is primarily responsible for the high strength (i.e., 700 MPa tensile strength) in this Al-Cu-Li-Ag-Mg alloy

Evaluation of the microstructure of Al-Cu-Li-Ag-Mg Weldalite (tm) alloys, part 4

Weldalite (trademark) 049 is an Al-Cu-Li-Ag-Mg alloy designed to have ultrahigh strength and to serve in aerospace applications. The alloy displays significantly higher strength than competitive alloys in both naturally aged and artificially aged tempers. The strengthening phases in such tempers have been identified to, in part, explain the mechanical properties attained. In general, the alloy is strengthened by delta prime Al3Li and Guinier-Preston (GP) zones in the naturally aged tempers. In artificially aged tempers in slightly underaged conditions, strengthening is provided by several phases including GP zones, theta prime Al2Cu, S prime Al2CuMg, T(sub 1) Al2CuLi, and possibly a new phase. In the peak strength artificially aged tempers, T(sub 1) is the predominant strengthening phase

Force sensor using changes in magnetic flux

A force sensor includes a magnetostrictive material and a magnetic field generator positioned in proximity thereto. A magnetic field is induced in and surrounding the magnetostrictive material such that lines of magnetic flux pass through the magnetostrictive material. A sensor positioned in the vicinity of the magnetostrictive material measures changes in one of flux angle and flux density when the magnetostrictive material experiences an applied force that is aligned with the lines of magnetic flux

How Patient Educators Teach Students: “Giving a Face to a Story”

Patient Educators are persons with specific pathologies that have participated in an education program in which they learn how to instruct students on physical examinations. The aim of this study was to explore the impact of graduate student experiences with Patient Educators during coursework on occupational therapy clinical internships. A phenomenological design was used to explore the lived experiences of students through a qualitative interview. As participants described their experiences with the Patient Educators, three primary themes emerged: (a) self-awareness, (b) confidence, and (c) empathy. The quotes from the transcriptions were organized into four sequential plot categories: (a) Before the Interaction, (b) During the Interaction, (c) Immediate Change, and (d) Impact on Clinical Internship. The results reveal a narrative of the learning process experienced by students from before the Patient Educators lab through clinical internships. These results suggest that incorporating Patient Educators in the classroom could be a critical component in preparing students for clinical internship and future clinical practice

Alternative dispute resolution : past, present, and future : an honors thesis (HONRS 499)

This research project examines Alternative Dispute Resolution; the most frequently used alternative method to the traditional litigation proceedings. The most popular forms of ADR were defined and examined, concentrating particularly on the processes of mediation and arbitration and their economic and time benefits. This assessment of ADR included the examination of the history of ADR in the legal system, the current weaknesses in the Adversarial system of justice, criticisms and benefits of the ADR process, and the statistical analysis of the current effectiveness of ADR. Through this evaluation it was projected that because of ADR's benefits of brevity and less restrictive economic cost, ADR will form a partnership with the adversarial system and become the dominant form of settling civil disputes.Honors CollegeThesis (B.?

Sex Differences in Adult Cognitive Deficits after Adolescent Nicotine Exposure in Rats

This study was designed to determine whether deficits in adult serial pattern learning caused by adolescent nicotine exposure persist as impairments in asymptotic performance, whether adolescent nicotine exposure differentially retards learning about pattern elements that are inconsistent with “perfect” pattern structure, and whether there are sex differences in rats’ response to adolescent nicotine exposure as assessed by a serial multiple choice task. The current study replicated the results of our initial report (Fountain, Rowan, Kelley, Willey, & Nolley, 2008) using this task by showing that adolescent nicotine exposure (1.0 mg/kg/day nicotine for 35 days) produced a specific cognitive impairment in male rats that persisted into adulthood at least a month after adolescent nicotine exposure ended. In addition, sex differences were observed even in controls, with additional evidence that adolescent nicotine exposure significantly impaired learning relative to same-sex controls for chunk boundary elements in males and for violation elements in females. All nicotine-induced impairments were overcome by additional training so that groups did not differ at asymptote. An examination of the types of errors rats made indicated that adolescent nicotine exposure slowed learning without affecting rats’ cognitive strategy in the task. This data pattern suggests that exposure to nicotine in adolescence may have impaired different aspects of adult stimulus-response discrimination learning processes in males and females, but left abstract rule learning processes relatively spared in both sexes. These effects converge with other findings in the field and reinforce the concern that adolescent nicotine exposure poses an important threat to cognitive capacity in adulthood

Selective Complexation and Reactivity of Metallic Nitride and Oxometallic Fullerenes with Lewis Acids and Use as an Effective Purification Method

Metallic nitride fullerenes (MNFs) and oxometallic fullerenes (OMFs) react quickly with an array of Lewis acids. Empty-cage fullerenes are largely unreactive under conditions used in this study. The reactivity order is Sc4O2@Ih-C80 \u3e Sc3N@C78 \u3e Sc3N@C68 \u3e Sc3N@D5h-C80 \u3e Sc3N@Ih-C80. Manipulations of Lewis acids, molar ratios, and kinetic differences within the family of OMF and MNF metallofullerenes are demonstrated in a selective precipitation scheme, which can be used either alone for purifying Sc3N@Ih-C80 or combined with a final high-performance liquid chromatography pass for Sc4O2@Ih-C80, Sc3N@D5h-C80, Sc3N@C68, or Sc3N@C78. The purification process is scalable. Analysis of the experimental rate constants versus electrochemical band gap explains the order of reactivity among the OMFs and MNFs