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Effects Of Nitrogen On The Growth Of Hyparrhenia Diplandra, J Nkandza

IGC Proceedings (1997-2023)

The nitrogen effects on Hyparrhenia diplandra were studied. Plants were grown on nutrient solutions of variable concentrations in nitrogen. The supplied nitrogen increased tillering, leaf production, lamina area, total dry matter accumulation and total nitrogen accumulation in lamina. A detailed examination showed that the effect on tillering was the main cause of the differences observed in dry weights between different treatments. The nitrogen supply elongated significantly the lamina and nitrogen deficiency increased its thickness; but this was not enough to compensate the loss of weight in lower nitrogen treatment. The lamina area as well as nitrogen accumulation in the lamina …

Movement Of Allelopathic Compound Coumarin From Plant Residue Of Sweet Vernalgrass (Anthoxanthum Odoratum L.) To Soil, Yoshito Yamamoto

IGC Proceedings (1997-2023)

This study investigated the movement of coumarin, an allelopathic compound, from the plant residue of sweet vernalgrass (Anthoxanthum odoratum L.) to soil, as well as the dynamics of coumarin in soil. The level of coumarin dissolved from sweet vernalgrass plant residue in both Andosols and Cambisols, which were watered every day, peaked on the 5th day after the beginning of watering, and fell gradually with each additional of day. Specifically, the coumarin content in Cambisols on the 5th day was 14.2 ppm, which is 4 times the coumarin level found in Andosols. The recovery percentage of coumarin extracted with …

Evaluating Functional Diversity As Potential Early-Warning Indicator Of Rangeland Degradation, L.-M. Schwarz, C. P. Carmona, M. C. Bilton, F. Munyebvu-Chambara, K. Behn, A. Linstädter

IGC Proceedings (1997-2023)

Droughts and overgrazing play a crucial role in the degradation of semi-arid rangelands. This is evident in the loss of palatable long-lived grass species and bush encroachment. Early warning indicators are needed to mitigate long-term degradation and decline in essential forage provision. Functional diversity provides valuable information on ecosystem health. However, functional diversity indices have not yet been tested regarding their applicability as early warning indicators, revealing non-linear threshold behaviour. We therefore examined the following questions: (1) How do functional diversity indices respond to grazing pressure? (2) Does land tenure affect the relationship between functional diversity and grazing pressure? (3) …

The Appalachian Gap In Preventable Hospitalizations: Are We Seeing Any Progress?, Rachel Hogg-Graham, Juan Lang, Teresa M. Waters

Journal of Appalachian Health

Introduction: Previous studies have documented geographic variation in preventable hospitalizations between rural and urban areas, but much less is known about preventable hospitalization patterns between heterogeneous rural areas. Unique challenges related to access of care and poverty may put the rural Appalachian Region at risk for higher rates of preventable hospitalizations.

Purpose: This study examines whether within-rural differences in Kentucky’s preventable hospitalization rates exist and how these differences may be changing over time.

Methods: Longitudinal and geographic trends in county-level preventable hospitalization rates were examined using Kentucky hospital discharge data from 2016 to 2019. Regression models were run to determine …

Variation Of Ldmc And Sla Relationship Between Growth Forms In Natural Grasslands, J. Viégas, P. Cruz, J. P. Theau, C. Jouany, P. Ansquer, R. Al Haj Khaled, O. Therond, M. Duru

IGC Proceedings (1997-2023)

In agro-ecological studies, there is a growing interest in measuring both leaf dry matter content (LDMC) and specific leaf area (SLA). This interest lies on the fact that leaf traits are linked to gradients of environmental factors and ecosystem functions. Working with three contrasting wild species, Garnier et al. (2001) proposed a model linking these two traits. The model shows a relatively simple non linear and negative correlation between LDMC and SLA. Nevertheless, none of the species used to build the model were grasses (GRA) or forb rosettes (ROS = i.e. dicotyledonous with large entire leaves and absence of …

A Study In Cuba Of The Biology, Ecology And Agroecological Management Of Heteropsylla Cubana Crawford In Leucaena Leucocephala (Lam.) De Wit, N. Valenciaga, M. Felicia Díaz, T. E. Ruíz, M. Fernández, C. Mora

IGC Proceedings (1997-2023)

As a consequence of the increase in Leucaena leucocephala areas to counter the shortage of feed in Cuban cattle production, there is a risk of the development of Heteropsylla cubana Crawford (Hemiptera: Psyllidae) as a pest in silvopastoral systems with this legume. This psyllid is known to be the main phytophagous pest (Valenciaga, 2003), which produces damage in 95% of the apical region of branches. Since information on the identification and biology of a pest species is a necessary prerequisite for its management, a taxonomic, biological and ecological study was conducted to define Heteropsylla behaviour in Cuban conditions and elaborate …

Effects Of Landscape Structure On Plants Species Richness In Small Grassland Remnants In Two Different Landscapes, S. A. O. Cousins, O. Eriksson

IGC Proceedings (1997-2023)

There is an increasing interest in using the landscape as the operational scale in many ecological studies. Current species richness in the landscape may be explained by past land use, and habitats may harbour species favoured by an environment that no longer exists. In this study we have included both a landscape scale and a temporal scale. The objective was to explain species pattern and the effect of isolation, habitat size and surrounding land use, and past land use change, on small grassland remnants in rural landscapes.

Rapid Scoping Review Of The Epidemiological Evidence For Mercury Exposure And Prevalence Of Alzheimer’S Disease, Rebecca Mattingly

Theses and Dissertations--Public Health (M.P.H. & Dr.P.H.)

This rapid scoping review examines the current body of epidemiologic research evaluating the potential linkage between environmental exposure to mercury and Alzheimer's disease (AD). Alzheimer’s disease accounts for 60-80% of all neurodegenerative disease in the United States and was the seventh leading cause of death in Kentucky in 2020. The exact etiology of AD needs further investigation; however, environmental factors such as pesticides, arsenic, cadmium, lead, and mercury have been correlated with development of AD lesions, cognitive decline, and AD. Mercury is a toxic metal that can be found in air, water, and soil, both from natural and human-made sources. …

Roadway Density And Lung Cancer Histology In Kentucky, Mahala Pettus

Theses and Dissertations--Public Health (M.P.H. & Dr.P.H.)

The purpose of this article was to examine the relationship between a proxy measure of exposure to automotive exhaust – roadway density – and risk for adenocarcinoma lung cancer. Using data from the Kentucky Cancer Registry and the Kentucky Geoportal Data Clearinghouse, we conducted a cross-sectional study of the distribution of adult lung cancer cases by histological type across the state of Kentucky. The north-central region of Kentucky has a higher prevalence of adenocarcinomas and greater roadway density. Among adenocarcinoma cases in Kentucky, there are more non-smokers than other types of tobacco use. As smoking rates decrease in Kentucky, and …

Poster Session, Kentucky Water Research Institute

Kentucky Water Resources Annual Symposium

• Evaluating the Effects of Beaver Dam Removal on the Hydrology, Water Quality, and Bioindicators of a Restored Wetland
• Predictive Sediment Flux Modeling of a Karst Spring Using High Resolution Sensors and Stable Carbon and Nitrogen Isotopes
• Development and Validation of qPCR Assays for Use in eDNA Detection of Four Species of Semiaquatic Salamanders .
• Analyzing Recent Spatio-Temporal Rainfall Erosivity Patterns and Trends Across Kentucky
• Development of eDNA Protocols for Detection of Four Darter (Percidae: Etheostomatinae) Species in Central Kentucky Streams
• Assessing Change in the Seasonality of Stable Isotopes δ18O and δ2H for Meteoric and Terrestrial Waters of Central Kentucky
• Coupling …

Relationships Between Biodiversity And Production In Grasslands At Local And Regional Scales, A. Hector, M. Loreau

IGC Proceedings (1997-2023)

Key points

1. Experimental manipulations of plant species diversity in unfertilised prairies and meadows has revealed that increasing diversity often leads to increased productivity (range of observed relationships varies from flat to log-linearly positive); driven by a combination of facilitation, niche-partitioning and sampling/selection effects.

2. The longer-term effects of diversity on ecosystem stability are not as clear and in need of further work.

3. Recent applied work, and a new review of the grassland literature, both show the potential for biodiversity to increase productivity under realistic field conditions.

4. The longer-term feedback of grazers on biodiversity gradients is unknown, and …

Global Atmospheric Change And Its Effect On Managed Grassland Systems, Andreas Lüscher, J. Fuhrer, P. C. D. Newton

IGC Proceedings (1997-2023)

Key points

1. Increasing atmospheric CO2 concentration and a trend to warmer mean temperatures are the most reliable aspects of global atmospheric change. Projections of the extent of climate change and the frequency of extreme weather conditions remain uncertain.

2. Research has considerably reduced the uncertainty about effects of global atmospheric change on physiology of plants, productivity and species composition of plant communities.

3. Other factors (e.g. nutrient availability, soil type) and long-term adaptation of the ecosystem (e.g. nutrient cycling and sequestration) influence the response of plant communities to global atmospheric change. Generalisation is not possible with respect to the …

Potential Of C4 Tropical Grasses To Contribute In Carbon Sequestration, Environmental Security And Livelihood Opportunities Through Increased Fodder Availability, D. R. Malaviya, A. K. Roy, P. Kaushal

IGC Proceedings (1997-2023)

The world grasslands/rangeland ecosystems comprise 26% of earth’s surface and have immense ecological and economic significance. Diversity of grasslands had been a key element for their sustainability. Grasslands in India have existed as natural ecosystems for millions of years. It is a major source of income, employment and livelihood to the rural families. Owing to heavy grazing pressure, coupled with other social/anthropogenic factors, the grazing resources have fast deteriorated. The country has many old and natural grasslands with ethnic and economic value. Comprehensive ecological studies including floristic compositions, dominant species, grazing pressure and the climax/sub-climax stages of ecological succession will …

Forb Counts In Grassland Are Sensitive To Analytical Method, Gene A. Fults

IGC Proceedings (1997-2023)

An analysis of forbs from 9 years of Plant Census protocol (NRI 2019) is compared to data from the Line Point Intercept (LPI) protocol. Both protocols were conducted on the same geospatially separate macroplots (N=1230). The macroplots locations were stratified by NRI based on a land hierarchy which has had long-term use in the United States (Salley etal 2015). This ties vegetation and land together in the data. The analysis showed that the 15-minute plant census method increased forb species data by 29 percent over the LPI method which takes 40-60 minutes. Both methods captured similar total ratios and rank …

Characterizing Invasiveness Through A Descriptive Study Of Guinea Grass (Megathyrsus Maximus) Growing In Three Habitat Types And Differing Herbivore Assemblages In Both Kenya And Texas, A. C. Rhodes, R. M. Plowes, D. J. Martins, I. Ng'iru, L. E. Gilbert

IGC Proceedings (1997-2023)

Guinea grass (Megathyrsus maximus syn. Panicum maximum) is an important pasture grass that has been introduced pantropically, yet in many cases has escaped cultivation and is invading native rangelands – threatening biodiversity at multiple trophic levels. An increasing challenge of rangeland management is balancing the importance of pasture grasses with their negative impact on ecosystem processes. Given this challenge, it is critical to understand the mechanisms that underlie grass invasion. In this descriptive study, our objective was to assess the ecological stress release hypothesis by comparing the relative abundance and functional traits of Guinea grass in Kenya's home …

An Integrated Framework To Study Ecological Tipping Points In Social-Ecological Systems, F. A. Männer, L.-M. Schwarz, D. A. Menestrey-Schwieger, V. Amputu, M. C. Bilton, K. Brinkmann, G. Dressler, N. Hamunyela, H. Heita, S. Heshmati, S. Liehr, M. Mbidzo, F. Munyebvu-Chambara, W. C. Nesongano, M. Rauchecker, A. Sandhage-Hofmann, K. Tielbörger, K. Zimmer, A. Linstädter

IGC Proceedings (1997-2023)

Sudden regime shifts or tipping points pose a major threat to various ecosystems and people's livelihoods worldwide. However, tipping points are still hard to predict and often occur without warning. To avoid dramatic social-ecological consequences, it is crucial to understand tipping point behaviour and to identify early warning indicators. Previous studies have hardly implemented an integrated social-ecological approach, which has led to a fragmented understanding and oversimplification of tipping point phenomena. Against this background, we present a systemic research framework that harmonizes ecological and social perspectives to gain a mechanistic understanding of tipping point behaviour. We utilize a social-ecological systems …

Effects Of Snake Fungal Disease On The Survival And Growth Of The Queensnake (Regina Septemvittata), Andrew Jerome Ibach

Theses and Dissertations--Forestry and Natural Resources

Having only emerged as a threat to snakes in 2006, relatively little is known of snake fungal disease’s (SFD) impacts on demographic processes, particularly survival and growth. I used data from an extensive capture-mark-recapture study to examine survival and growth in central Kentucky Queensnake (Regina septemivittata) populations. I found that diseased snakes and healthy snakes possessed similar monthly survival estimates (SFD positive 0.9687, 95% CI 0.8444 to 0.9944; SFD negative 0.8735, 95% CI 0.7518 to 0.9402) and that disease state transition probability from SFD negative to SFD positive, and SFD positive to SFD negative were also similar (N-P …

Investigation Of Pfas Exposure Risks In Kentucky Using Mapping Tools, Sweta Ojha

Theses and Dissertations--Civil Engineering

Per- and polyfluoroalkyl substances (PFAS), a group of environmentally-persistent compounds, are environmentally ubiquitous and challenging to remediate. Several studies show that PFAS are detected in drinking water systems when sampling is conducted, making human exposure via drinking water an important health consideration. This research: 1) develops a mapping tool for prioritizing sampling locations; 2) establishes a method for making GIS data and meta(data) in the mapping tool accessible; 3) fosters decision making by integrating knowledge brokering and the alignment interest and influence matrix (AIIM). The tool developed is this research is a geospatial and statistical PFAS hot-spot screening model that …

An Ecological Study Of Glyphosate Use And Non-Hodgkin’S Lymphoma, Dexter Corlett, Steven R. Browning

Theses and Dissertations--Public Health (M.P.H. & Dr.P.H.)

Glyphosate is currently the most widely used herbicide in the world. Initially thought to be non-carcinogenic in humans, in 2015 glyphosate was classified as a “probable carcinogen” by the International Agency for Research on Cancer due to several small epidemiological studies indicating a link between the pesticide and hematologic cancers, especially non-Hodgkin’s lymphoma (NHL). The current work is an ecological study using counties in Kentucky, Arkansas, and Iowa to compare glyphosate usage to NHL incidence using a multivariate Poisson regression. We found no significant correlation between glyphosate use and NHL incidence, though caution should be taken to draw significance from …

Local Public Health System Comprehensiveness And Opioid Overdose Mortality, 2012-2018, Stephanie Courtney

Theses and Dissertations--Public Health (M.P.H. & Dr.P.H.)

Background: Deaths due to opioid overdose are a significant public health burden in the United States. Studies suggest that local public health systems that perform a high number of essential activities where local health departments contribute to the delivery of the activities and promote increased partnership may positively influence population health outcomes such as overdose mortality. Studies have shown that comprehensive public health systems are associated with improved health outcomes, but this association has not been addressed in the context of opioid overdose deaths. Study Aim: The purpose of this study is to evaluate the associations between local public health …

Maternal Occupational Exposure To Organic Solvents And Noise: Maternal Effects And Infant Outcomes, Kristen Van Buren

Theses and Dissertations--Public Health (M.P.H. & Dr.P.H.)

Introduction: Several maternal occupational exposures have not yet been studied for potential reproductive harm or have inconsistent findings in the literature. Despite the challenges, identification of potential risk factors, specifically reproductive toxicants, is necessary to mitigate and prevent adverse health outcomes for working mothers and their infants. The purpose of this study was to examine maternal occupational exposure to organic solvents and noise to small-for-gestational age (SGA) and preterm birth (PTB) among infants. Additionally, the study sought to examine maternal occupational exposure to noise and presence of gestational diabetes (GDM) and pregnancy-related hypertension among participant mothers.

Methods: The study population …

Potential Impact Of Socioeconomic Status On Complications Associated With Obesity In Adult Women In The United States., Cassidy Taylor

Theses and Dissertations--Public Health (M.P.H. & Dr.P.H.)

Abstract

The purpose of this project is to determine whether there is an association between socioeconomic factors and complications of obesity in adult women in the United States based on the national 2020 Behavioral Risk Factor Surveillance System (BRFSS) data.

Dependent variables were categorized as complications associated with obesity in adult, obese women. BRFSS items that referenced objective measures regarding chronic obesity-related complications included items such as diabetes, heart disease, arthritis, and breast cancer diagnosis. Two measures relating to participants’ socioeconomic status were also used as independent variables. BRFSS items that referenced objective measures regarding socioeconomic status are educational attainment, …

Study Of The Diversity Of Soil Animals Community In The Songnen Plain Grassland Of China, Xiuqin Yin, Tingcheng Zhu

IGC Proceedings (1997-2023)

This paper dealt with the diversity in eight habitat soil animals communities in Songnen plain grassland. The results showed the better habitat condition the higher diversity index of soil animals, and vice-versa. The diversity of soil animals communities correlated positively with soil organic matter, total nitrogen, and negatively with soil pH; there was a poor correlation with soil water content and total soil phosphorus. The diversity of soil animals communities decreased with increasing depth of soil layer and has surface-collection.

Biodiversity And Fire In Shortgrass Steppe, Paulette L. Ford

IGC Proceedings (1997-2023)

Effects of fire at two levels of intensity on beetle diversity in shortgrass steppe were examined. The experimental design was completely randomized, with 3 treatments and 4 replicates per treatment. Treatments were two levels of fire 1) dormant-season fire (relatively hot), and 2) growing-season fire (relatively cool), and unburned plots. The response variables were arthropod species richness and abundance. The intermediate disturbance hypothesis predicts that maximum species richness occurs at intermediate levels of disturbance. Data obtained in this study support that prediction. Species richness was higher on plots of intermediate fire intensity than the more intensely burned plots, and almost …

The Legume – Rhizobia Symbiosis. Does It Vary For The Tropics Relative To The Mediterranean Basin?, J. G. Howieson, A. Mcinnes

IGC Proceedings (1997-2023)

Symbiotic N fixation from legumes is one of the most important biological processes on the planet. It currently provides the majority of the N requirement in agriculture, yet will have to double if cereal crop production is to meet world demand by 2020 (Kennedy and Cocking 1997). To effectively harness the value of biological N fixation from legumes we need to more fully understand G² x E; where G refers to the genotypes of both the legume (G_l) and its microsymbiont (rhizobia; G_r), and E refers to the edaphic environment in which the symbiosis is …

Agronomic Evaluation Of Alfalfa Cultivars In Rio Grande Do Sul, Brasil, J. C. De Saibro, R. Battisti, T. M. S. Freitas

IGC Proceedings (1997-2023)

From April 1995 to June 1998, thirty five alfalfa (Medicago sativa L.) cultivars (cvs.) were evaluated in a field trial at the “Depressão Central” ecoclimatic region, in southern Brazil. Two years after sowing, 30 cultivars were excluded from the test due to their poor overall agronomic performance, mainly low forage DM yields. The remaining cultivars: Crioula (local genotype used as a check), Victoria, Rio and P 30 are hay-type cultivars while Alfagraze is a grazing-tolerant type. Twenty-two harvests were made and no significant differences were found for total DM yields among cvs. Crioula, Victoria, Rio and P 30; however, …

Amphicarpy In The Tropical Legume Centrosema Rotundifolium: A Research Project In Eastern Venezuela, S. Müller, R. Schultze-Kraft, I. Rodríguez

IGC Proceedings (1997-2023)

Amphicarpy is a particular reproduction mechanism by which a plant can produce both above-ground and below-ground seeds and thus has the potential to contribute to an enhanced persistence of a plant population. It can be found in a range of tropical legumes, e.g. in several Centrosema species. The balance between above- and below-ground seed production is evidently influenced by environment and management factors but these influences are not well known. In the case of perennial tropical legumes, in addition to seed production shifts the allocation of resources affects also the production of tuberous roots as storage organs. A research project …

Knowledge About And Knowledge With: Contributions From Feminist Research To Knowledge Co-Production For Pastoral Systems, F. Ravera, María Fernández-Giménez, E. Oteros-Rozas

IGC Proceedings (1997-2023)

Globally, the gender dynamics of rangeland social-ecological systems have received scant attention. Further, research paradigms, methods and methodologies that leave little room for equitable engagement with research participants and genuine action-oriented research-practice partnerships dominate in pastoralist/rangeland studies. Our research is informed by a feminist philosophy of science and based on decolonial and feminist political ecology studies that focus on gendered science and knowledge production. Feminist research calls for reflection on who produces knowledge and how such knowledge is used and shared. Feminist practices such as reciprocity, care, and positionality, cultivate awareness of the power dynamics embedded in the research process …

Soil Microbial Carbon, Nitrate And Ammonium Nitrogen Dynamics In Urochloa Grass Cultivated In Sub-Humid Kenya, K. W. Ndung’U-Magiroi, M. N. Koech, M. C. Mutoko, M. Kamidi, Elias M. Gichangi, Donald M. G. Njarui

IGC Proceedings (1997-2023)

A study was conducted to monitor the dynamics of available soil phosphorus (P), soil microbial biomass carbon (SMBC), nitrogen (SMBN), ammonium and nitrate nitrogen under seven Urochloa grass cultivars at Kitale, Kenya. The Urochloa cultivars: Urochloa brizantha cvs. Marandu, MG-4, Piata, Xaraes, U. decumbens cv. Basilisk, U. hybrid cv. Mulato II and U. humidicola cv. Llanero was compared with two popularly grown forages, Rhodes grass (Chloris gayana cv. KAT R3), Napier grass (Pennisetum purpureum cv. KK1) and annual weeds. The treatments were tested in a randomized complete block design arranged in a split plot treatment structure with two …

Climate Smart Urochloa Grasses Improves Soil Health In The Semi-Arid Tropics Of Kenya, Elias M. Gichangi, Donald M. G. Njarui, Mwangi Gatheru

IGC Proceedings (1997-2023)

The measurement of soil aggregates stability and soil microbial biomass can be used as an early indicator of long-term changes in soil quality. A study was conducted to quantify the amounts of shoots and roots biomass of Urochloa grass cultivars (commonly known as Brachiaria) and their effects on changes in the size distribution and stability of soil aggregates and on microbial biomass carbon (C), nitrogen (N) and phosphorus (P) in a structurally unstable sandy loam soil at Ithookwe and Katumani in semi-arid tropical Kenya. The Urochloa grass cultivars included Urochloa decumbens cv. Basilisk, U. brizantha cvs Marandu, MG-4, Piatã and …