Sixteen stands representing a range of structural variation in aspen, mixed aspen-conifer, and spruce-fir communities of the Wasatch Plateau, Utah, were censused by the sample count method. The stands were classified as eleven community types based on the understory dominants or indicator species and the cover types. Fifty bird species were recorded during the two seasons; thirty-two occurred in aspen cover, forty-four in mixed aspen-conifer cover, and twenty-two in spruce-fir. Comparisons of the composition and density of bird populations were made between uniform stands of a single life form and more structurally complex stands of either single or mixed life forms. Limiting factors in the structural characteristics of the stands were identified for birds restricted to particular stands. Low avian similarities between some aspen stands were attributed to the differences in structure between the stands. Bird species which favored the deciduous life form tended to decrease in abundance in the mixed stands as the canopy coverage of conifers increased, and they were absent in the spruce-fir stand. Coniferous forest bird species were more abundant in mixed stands with high coniferous coverage than in the aspen-dominated stands. Low individual bird numbers were found in the conifer stand of uniform small trees. Several vegetational characteristics of the stands were evaluated to determine if any was an index of forest heterogeneity predictive of bird species diversity. The habitat features of ecological relevance to most of the bird species were the size, spacing, and life form of the trees. The diversity of the distribution of diameter measurements at breast height for the tree species was predictive of bird species diversity. High diversity in the distribution of tree measurements at breast height was correlated with variation in tree height, tree canopy diameter, and the spacing of the life forms. It was therefore an index of three dimensional environmental patchiness, easily visualized by the variation in life forms and the number of stories within the stand.

The primary objective of this study was to examine rice production methods with special emphasis on farm and water irrigation management practices in the different rice farm types of the Guayas Basin of Ecuador. To do this, farmers were divided into eight categories on the basis of farm practices, seasonal farming, irrigation facilities and level of mechanization. Profits per hectare ranged from 4,807 to 762.10 sucres per hectare. Mechanization varied from totally mechanized to total absence of machinery. Year round farming varied to seasonal farming. Average production varied from 110 quintals of hulled rice to 20 quintals per hectare. The preparation of farm budgets for the different types, presented some problems, due to the lack of available records by the small farmers and reluctance to provide data by the large mechanized units. The cost/benefit ratios of changing from one type of farming to another were calculated as well as the labor absorption possibilities for the different types of farming. These could provide a criteria for planification of rice policies in Ecuador.

Indiana University-Purdue University Indianapolis (IUPUI) / The Indian summer monsoon (ISM) is the dominant hydrometeorological phenomenon that provides the majority of precipitation to southern Asia and southeastern Tibet specifically. Reliable projections of ISM rainfall are critical for water management and hinge on our understanding of the drivers of the monsoon system and how these drivers will be impacted by climate change. Because instrumental climate records are limited in space and time, natural climate archives are required to understand how the ISM varied in the past in response to changes in climatic boundary climate conditions. Lake sediments are high-resolution natural paleoclimate archive that are widely distributed across the Tibetan Plateau, making them useful for investigating long-term precipitation trends and their response to climatic boundary conditions. To investigate changes in monsoon intensity during the Holocene, three lakes were sampled along an east-west transect in southeastern Tibet: Galang Co, Nir’Pa Co, and Cuobu. Paleoclimate records from each lake were developed using isotopic (leaf wax hydrogen isotopes; δ2H), sedimentological, and geochemical proxies of precipitation and lake levels. Sediments were sampled at high temporal frequencies, with most proxies resolved at decadal scales, to capture multi-decadal to millennial-scale variability in monsoon intensity and local hydroclimate conditions. The ISM was strongest in the early Holocene as evidenced by leaf-wax n-alkane δ2H at both Cuobu and Galang Co corresponding with Cuobu’s higher lake levels and effective moisture. Monsoon intensity declined at Cuobu and Galang Co around 6 ka which corresponds to reduced riverine sediment influxes at Cuobu and deeper lake levels at Galang Co. The antiphase relationship between lake levels and monsoon intensity at Galang Co is attributed to air temperatures and effective moisture, with a warmer and drier local hydroclimate driving early Holocene low lake levels. The late Holocene ISM was more variable with wet and dry periods, as seen in the Nir’Pa Co lake level and leaf wax n-alkane δ2H record. These records demonstrate coherent drivers of synoptic and local hydroclimate that account for Holocene ISM expression across the southeastern Tibetan Plateau, indicating possible drivers of future monsoon expression under climate change.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第18330号 / 農博第2055号 / 新制||農||1022(附属図書館) / 学位論文||H26||N4837(農学部図書室) / 31188 / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 荒井 修亮, 教授 山下 洋, 准教授 笠井 亮秀 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

No description available.

Summer pasture-associated recurrent airway obstruction (SPARAO) is characterized by reversible airway obstruction resulting from airway hyper-reactivity to aeroallergens, mucus accumulation, and airway inflammation. These are key clinical features that are shared with human asthma, suggesting SPARAO’s utility as an animal asthma model. SPARAO affects horses maintained on pasture in conditions of high heat and humidity. Common in the southeastern United States, the cause of SPARAO is unknown, but is presumed to reflect reactivity to seasonally inhaled pasture-associated aeroallergens. This investigation sought to identify well-characterized histopathological lesions of human asthma, collectively termed ‘asthmatic remodeling’, in lung tissue from horses with SPARAO. Two histological staining techniques were used: H&E and Movat’s Pentachrome. Similar to chronic asthma, lung tissue from horses with SPARAO demonstrates statistically significant increases in airway smooth muscle, fibrosis, airway occlusion and inflammation, goblet cell hyperplasia, and remodeling of terminal bronchioles and elastin fibers.

Youth-serving organizations, such as 4-H, place a large emphasis on positive youth development and experiential learning in order to assist youth in acquiring specific life skills. The literature suggests that residential summer camps are one of the best ways to provide positive youth development, experiential learning, and targeted life skills. This study was a mixed methods design which utilized four residential summer programs throughout the state of Mississippi in order to compare the differences between the residential 4-H summer programs that took place on a university campus to those that took place within the naturalistic environment. The results of this study indicate that on-campus residential summer programs achieved the essential elements of positive youth development more so than those that took place within the naturalistic environment. The on-campus program participants also acquired targeted life skills more so than those that participated in programs that took place within the naturalistic environment.

Bats are important components of biodiversity within forested ecosystems. This research addressed habitat characteristics that influence species occupancy and stable isotopes and wing morphology to assess community structure within the Sam D. Hamilton Noxubee National Wildlife Refuge. To meet these objectives, I deployed echolocation recorders, mist-nets and conducted roost checks to capture bat acoustics; fur samples were also collected to measure ratios of carbon (C13/12) and nitrogen (N15/14). Relationships between occupancy, habitat class and features were not apparent for most species. However, Lasiurus and Mytois spp. showed positive relationships with proximity to roads, Lasiurus, positive with stem density and Perimyotis subflavus, negative with basal area. Stable isotope analysis revealed some distinction of trophic niches while wing morphometrics indicated bats of similar wing shape and size show greater trophic overlap. Collectively, these results suggest that habitat management, as current within the study area, will have limited influence on local bat distributions.

The Mississippi State University leaderSTATE STEM program provides a variety of experiences for Junior Reserve Officers Training Corps (JROTC) high school cadets across three states: Mississippi, Alabama and Louisiana, the majority from underrepresented demographic populations. LeaderSTATE STEM offers 5-day residential summer camps (N=6) for over 300 students annually. The camps utilize a variety of geosciences STEM activities to increase students' awareness of science and opportunities in geoscience careers. To evaluate the effectiveness of student attitudes towards science, the Test of Science Related Attitudes (TOSRA) instrument was used to ascertain changes in attitudes about science and society. Paired pre-post TOSRA survey results from 2014-2017 camp cycles (N= 1141 students) were analyzed for race, gender, and school correlations. Chi square analysis revealed only a scattered statistical improvement throughout the data (p = 0.05). More research is needed to determine whether the 5-day experience is too limited to result in high school students' attitudinal changes towards science, or whether the TOSRA instrument provides an appropriate assessment for the leaderSTATE STEM camps. A secondary assessment instrument was employed pre- and post-camp to ascertain the abilities of the students in their interpretation of graphically displayed data. That instrument assessed changes in the students' abilities in understanding basic data terminology and interpretation of data shown on graphs. Assessment was performed with a pre-camp - post-camp survey and analysis of change determined with a paired t-test with Cohen's d to determine effect size. A significant p value below 0.05 was determined for only one of six camps in 2016, and for three of six camps in 2017. In both years, Cohen's d effect size was small for two of six camps annually, and medium for all other camps. A follow-on weather data project was developed for, and implemented with, the students in the JROTC programs in the seven schools in the Jackson, Mississippi school district. That month-long project was an extension of topics introduced in the leaderSTATE summer camp program. Two schools performed well in both years of the project, two schools performed in the mid-range, and three schools underperformed in both years of the project.

No description available.