Insulin-like growth factor binding proteins (IGFBP) are modulators of insulin-like growth factor I (IGF-I), which functions as a regulator of cartilage and bone development. Rapid growth and high starch diets have been associated with increased circulating concentrations of IGF-I, which lead to developmental orthopedic disorders in foals. The objective of this study was to assess the effects of age, diet, growth and season on plasma IGFBP and IGF-I concentrations from birth to 16 mo of age in Thoroughbred foals. Twenty-two mares maintained on mixed grass/legume pasture were randomly divided into two dietary groups and fed either a high starch and sugar supplement (SS) or a starch-restricted fiber and fat supplement (FF) for 3 mo prior to and after foaling. Monthly blood samples were obtained from SS and FF foals up to 16 mo of age and analyzed for IGF-I using an RIA and IGFBP using western ligand blot analysis. Auxilogical measurements of foals were also obtained each month. The effect of diet, month, and diet*month interactions upon the subject horse (diet) were analyzed using a mixed model with repeated measures, and correlations of normally distributed data were calculated using Pearson's correlation. Six IGFBP bands of molecular weights 109, 39, 36, 35, 34, and 33 kDa were identified in foal plasma. Doublet bands were recognized at 109, 39, and 35 kDa, however they were not all believed to be singular pure IGFBP. A band with a molecular weight of 213 kDa was observed and presumed to be a ternary complex of IGFBP-3, IGF-I, and an acid labile subunit. The IGFBP 109 kDa has been previously recognized as a band unique to the equine, it was not a singular pure IGFBP because of its high molecular weight. No effect of diet on plasma IGFBP was found in individual sampling of yearlings, but an effect of month was noted when testing May - August 2001 against May - August 2002 in pooled plasma samples with concentrations of the IGFBP 39 kDa increasing (P < 0.0003). In contrast, concentrations of the IGFBP's 33, 34 and 36 kDa decreased (P < 0.003, P < 0.0002, and P < 0.0003 respectively). Environmental effects were noted upon IGFBP's 33, 36, 39, and 109 kDa (P < 0.003, P < 0.001, P < 0.04, and P < 0.01) with a temperature*daylength interaction. Correlations existed between ADG and IGFBP 33 (r = 0.64; P < 0.0001), 34 (r = 0.40; P < 0.0001), 35 (r = 0.33; P < 0.0006), 36 (r = 0.47; P < 0.0001), and 39 kDa (r = - 0.18, P < 0.02). A correlation was also found between IGF-I and ADG (r = 0.11; P < 0.04), confirming the previously reported relationship of IGF-I in growth rate of foals. These results underline the importance of characterizing the activity of IGFBP's in relation to growth, age and season when interpreting changes of the somatotropic axis. Further, the increase in certain IGFBP's and simultaneous decrease in others stress the need for further research on the tissue specific modulating effects that IGFBP's have on IGF-I. / Master of Science

The accuracy of the growing season used by regulators in hydric soil and wetland hydrology and the validity of ignoring land use in these definitions is questionable. This study compared measured air and soil temperature with various growing season dates and indicators, and determined the relationships between the hydrology, air and soil temperature. Water table depths, air temperature at 1-m height, soil temperature at 15-, 30-, and 50-cm depths, and CO₂ efflux were measured at 12 plots representing three landuse treatments (forest, field, and bare ground) at two restored wet flats in the thermic Great Dismal Swamp ecosystem. The forest was driest treatment. The forest air was the warmest in winter and coldest in summer, opposite of the bare ground. The forest soil at 50 cm was the warmest in winter and coolest in summer, opposite of the bare ground. Land use affected hydrology, air, and soil temperatures through the presence of surface litter and differences in shading, albedo, and ET. The regulatory frost-free period fell in between the measured frost-free period and the measured 5°C soil temperature period. Based on CO₂ efflux and soil temperature at 50 cm, the biological growing season of native plants and microbes should be year-round for forested areas, one week shorter for early-successional fields, and two weeks shorter for active cropland rather than March to November for all land uses. Changing the growing season definition of forested, thermic wet flats to year-round designation must be considered and studied carefully to avoid jeopardizing wetland hydrology qualifications. / Master of Science

Climate change, habitat degradation, and infectious disease are major drivers of global amphibian declines. Amphibians are particularly susceptible to these factors due to their unique physiology and habitat requirements. Thus, investigating components of amphibian physiology and evaluating the influence of environmental conditions, perceived threats, and encounters with infectious agents is essential to conserving imperiled amphibian species. Here, I measured hematocrit, hemoglobin, relative proportions of polychromatic red blood cells, and white blood cell differentials in a wild population of male Eastern Hellbender salamanders (<i>Cryptobranchus alleganiensis</i>) which remain with their nest for up to ~8 months and have frequent encounters with parasitic leeches (<i>Placobdella appalachiensis</i>) that transmit hematophagous endoparasites (Trypanosoma sp.), often resulting in coinfection. Results indicate that hematocrit and hemoglobin increase in response to acute stress and with temperature. Additionally, the magnitude of the stress-induced hemoconcentration response was greater at lower temperatures. Hellbenders exhibited an increase in the proportion of neutrophils and eosinophils in circulation as temperatures decreased while the proportions of lymphocytes and basophils had an inverse effect. Furthermore, the proportion of neutrophil precursors also increased as temperature decreased, which signifies recruitment of innate immune cells during seasonally cold periods. Coinfection of the leech and trypanosome parasites resulted in decreased hematocrit and hemoglobin and a marked increase in polychromatic red blood cells which is indicative of regenerative anemia in the hellbender host. However, these effects were not present in individuals only infected with trypanosomes, implicating the leech vector as the key contributor to anemia in hellbenders. Moreover, the proportion of neutrophils and eosinophils increased, while lymphocytes decreased, in response to leech attachment. However, as parasitemia of leeches and trypanosomes increased concurrently, the proportion of lymphocytes increase in circulation while neutrophils and eosinophils decrease, underscoring the complexities associated with coinfection and multi-parasite interactions. Together, this research provides novel insights into the blood physiology of an imperiled salamander by establishing reference values essential for population surveillance while also describing how these values fluctuate across season and in response to extrinsic factors, with an emphasis on co-occurring hematophagous parasites. / Master of Science / While large losses of biodiversity are a global trend among vertebrate populations, amphibian species are most at risk of extinction due to the compounding effects of infectious disease, habitat degradation, and climate change. Understanding how these factors impact the health, condition, and survival of imperiled species is vital to monitoring populations and developing successful conservation strategies. Here, I used hematological metrics that are associated with respiratory, metabolic, and immune responses to monitor a wild population of imperiled eastern hellbender salamanders (<i>Cryptobranchus alleganiensis</i>). Eastern hellbenders are fully aquatic giant salamanders that engage in an ~8-month solitary paternal care period and have faced precipitous declines in recent decades. Furthermore, hellbender populations in southwest Virginia harbor parasitic leeches (<i>Placobdella appalachiensis</i>) which act as vectors for blood-feeding endoparasites (Trypanosoma sp.), frequently leading to coinfection. My aim was to gain mechanistic insight into how hellbender blood physiology varies with environmental conditions, how they respond to potential threats like acute stressors, and how parasites and coinfection impact their health. Through my research, I discovered fascinating insights into the physiology of hellbenders. When faced with environmental temperature changes and acute stress, hellbenders adapt by modulating the red blood cell concentration in their blood, enhancing blood-oxygen-carrying capacity, to meet increased metabolic demands. Furthermore, white blood cell parameters of hellbenders exhibit seasonal changes, which may indicate an increased reliance on mechanisms of innate immune responses during colder temperatures, when cells associated with adaptive immune responses are less active. My study also revealed that coinfection of the leech vector and trypanosome parasites in hellbenders can trigger immune responses and lead to regenerative anemia in the host. However, the pathologies associated with anemia in hellbenders were attributed to the leech vector rather than the trypanosome parasite it transmits. These findings shed light on the physiology of amphibians and have important implications for population surveillance, particularly in identifying potential environmental factors that threaten imperiled species.

Spectral reflectance-based, remote sensing technology has been used to adjust in-season nitrogen (N) fertilizer rates for wheat to account for spatial variability in grain yield potential at a sub-meter resolution. The objective of this study was to examine the relationships among spectral reflectance indices, corn tissue N content, chlorophyll measurements, plant size and spacing measurements, and grain yield to develop a similar strategy for variable-rate N management in corn. Irrigated and non-irrigated studies were conducted during the 2002 and 2003 growing seasons in eastern Virginia. Plots were treated with various rates of preplant, starter, and sidedress N fertilizer to establish a wide range of grain yield potential. Spectral measurements, tissue N, chlorophyll measurements, and plant physical measurements were collected at growth stages V6, V8, and V10. At maturity, grain yield was determined and correlated with in-season data and optimum N rate to calibrate in-season, variable-rate N fertilization strategies. Results from these studies indicate that spectral reflectance is well correlated with plant N uptake and chlorophyll meter readings and can also be correlated with final grain yield. These relationships may be used to develop a model to predict in-season, variable N application rates for corn production at a sub-meter resolution. / Master of Science

Over the past several decades, native and managed bee populations have decreased in the United States and worldwide. Although bee decline is attributable to several factors, habitat loss is the primary driver. Simultaneously, cattle producers in the eastern U.S. rely primarily on cool-season forages that peak in biomass production in late spring, leading to a lack of forage in the summer months and increasing the costs of cattle production. Seeding pastures with a mix of native warm-season grasses and native wildflowers could increase forage availability while also increasing available resources for bees. In this study, a mix of three native warm-season grasses (NWSGs) and 15 wildflower species was planted at the Virginia Tech Shenandoah Valley Agricultural Research and Extension Center (SVAREC). The objectives of this project were to document the establishment and species composition of NWSG + wildflower pasture mixtures, compare the attractiveness of wildflowers and weedy species to bees, and compare the bee community between NWSG + wildflower pastures and more typical cool-season grass pastures. The wildflowers in the NWSG + wildflower pastures dominated over grasses. All wildflower species that established were attractive to bees, as were some weedy species. The NWSG + wildflower treatments had the highest abundance of bees collected, with an average of 14.8 bees collected per pasture per sampling date in 2018, and an average of 12.4 bees collected per pasture per sampling date in 2019. These results indicate that with modification of establishment methods so that more grasses are present, this pasture system could be beneficial from both a cattle production and bee conservation standpoint. / Master of Science in Life Sciences / Over the past several decades, there has been a decline in bee populations in the U.S. and around the world. Bees play an important role in pollinating many food crops, including most fruits and vegetables. Habitat loss is the biggest contributor to their decline. There are also issues with cattle production in the eastern U.S. Most farmers rely on grasses that are the most productive in the late spring and early summer, meaning that by mid- and late summer, there is little grass available for cattle. Planting pastures with native grasses designed to be the most productive in the late summer and native wildflowers could increase food available for cattle as well as provide more pollen and nectar for bees. In this experiment, we planted a mix of three grasses and 15 wildflowers. We documented how well the grasses and wildflowers established. We also examined how attractive wildflowers and weeds were to bees and compared the number and types of bees collected between the new pastures and traditional pastures. We found that the wildflowers, instead of the grasses, dominated the pastures. All wildflowers that established, as well as some weeds, attracted bees and provided resources. Higher numbers of bees were collected in the pastures with wildflowers than standard grass pastures, but there were not necessarily more bee species present. These results suggest that, with some modifications, planting native grasses and wildflowers in pastures could help conserve bees as well as benefit cattle farmers.

The focus of this research was to evaluate commonly used insecticides and plant based scouting practices in cotton, Gossypium hirsutum (L.), prior to bloom for tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), management. As well as determine the influence of ThryvOn technology on these research objectives. Data indicate that imidacloprid may have a limited fit in non-ThryvOn cotton, while the additional mode of action afforded by ThryvOn technology could extend imidacloprid and other insecticide’s effective use prior to bloom. Additionally, sulfoxaflor and acephate remain the best products for pre-bloom management. When evaluating differences between plant based scouting methods prior to bloom used among cotton consultants across the Mid-Southern region, cotton technology and tarnished plant bug control did not cause variability in square retention monitoring methods, while sample date, or cotton growth did. However, based off these results, plant-based extension scouting recommendations do not need altering at this time.

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is an important economic pest of cotton, Gossypium hirsutum (L.), in the Midsouth region of the United States. Continuous season long infestations may result in four or more insecticide applications per growing season. However, late season applications may only be preventing minor losses when compared to overall yield. Results from this study suggest an opportunity to increase thresholds and potentially eliminate one to two insecticide applications in late bloom. Results from this experiment show no significant differences in yield when all square removal levels were simulated in the fourth and fifth week of bloom. Other factors included irrigation and cotton seed technology. Use of threshold irrigation and ThryvOn cotton resulted in greater yields than non-irrigated cotton and non-ThryvOn cotton. Information from these experiments will be used in future integrated pest management programs for more sustainable cotton production in Mississippi.

京都大学 / 新制・課程博士 / 博士(農学) / 甲第25353号 / 農博第2619号 / 新制||農||1108(附属図書館) / 学位論文||R6||N5525 / DGAM / 京都大学大学院農学研究科地域環境科学専攻 / (主査)准教授 大澤 直哉, 教授 日本 典秀, 教授 田中 千尋 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

O rio do Peixe, um dos principais afluentes do rio Tietê (Reservatório de Barra Bonita/Hidrovia Tietê Paraná), juntamente com seus formadores (microrregião geográfica de Botucatu - SP) constituem os principais mananciais das cidades que se localizam em suas bacias. A maior parte da bacia hidrográfica do rio do Peixe desenvolve-se sob rochas sedimentares arenosas, favoráveis às atividades de extração de areia, fato que aliado ao manejo incorreto do solo favorece a ocorrência de processos erosivos. Foram realizadas amostragens de água durante dez dias consecutivos e de sedimento durante três dias alternados, em dois períodos hidrológicos (seca e chuva), para a determinação de variáveis físicas, químicas e biológicas,com o objetivo principal de caracterizar do ponto de vista limnológico esse rio e sua foz. As análises das diferentes variáveis seguiram os métodos que são utilizados rotineiramente no Laboratório de Limnologia do CRHEA/EESC/USP. As águas do rio do Peixe apresentaram, principalmente altas concentrações de sólidos em suspensão. Os maiores valores de turbidez, condutividade, alcalinidade, HCO3-, CO3-, nitrito, nitrogênio amoniacal, nitrogênio Kjedhal, fosfato inorgânico, carbono orgânico e sólidos em suspensão foram obtidos durante o período de chuvas, influenciados principalmente pelo escoamento superficial que promove o carreamento de materiais da bacia hidrográfica. Foi possível ainda através das características limnológicas, agrupar as estações de amostragem ao longo do contínuo do rio em três regiões (alto, médio e baixo curso), e diferenciar do ponto de vista trófico as estações da foz com o rio Tietê. Um aumento da biomassa fitoplanctônica, no período de seca, no baixo curso do rio do Peixe foi favorecido pela menor vazão na barragem de Barra Bonita. / Peixe river, one of the main Tietê river\'s tributaries (Barra Bonita Reservoir/ Hydrovia Tietê Paraná), connected to its formers (geographic micro region of Botucatu- SP) are the main water sources to the cities located in their basins. Most of the Peixe river hydrographic basin runs through sandy sedimentary rocks, propitious to sand extraction activity. This fact, allied to improper use of the soil, lead to erosive processes occurrence. In the present work, water and sediment samples (dry and raining season) were taken during ten consecutive days and three alternate days, respectively. Physical, chemical and biological analyses were determined to characterize, under the limnological point of view, this river and its mouth; all these analysis were made following the methodology used in the Limnology Laboratory of CRHEA/EESC/USP. Peixe River waters showed high concentrations of suspended solids. The higher values of turbidity, conductivity, alcalinity, HCO3-, CO32-, nitrite, ammonium, Kjeldahl nitrogen, inorganic phosphate, organic carbon and suspended solids were obtained during the raining season, influenced by the surface water running that causes an input of material from the hydrographic basin. It was possible, by using the limnological characteristics, to duster the sampling stations throughout the river continuum in three regions: high, medium and low course, setting them apart from the Tietê\'s mouth sampling stations in account of distinct trophic state. Phytoplankton biomass increased during the dry season, in the low course of Peixe river, due to the lower flow towards Barra Bonita reservoir.

Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This work was carried out in the county of Valen?a - RJ, with the objective to evaluate production and quality of the stargrass, in function of: two irrigation levels (with and without); four cut intervals (21, 28, 35 and 42 at the rainy season and 28, 35, 42 and 49 days at the dry season of the year); as well as four levels of nitrogen (0, 150, 300 e 600 kg/ha/year). The dry matter production (DMP) and the efficiency of the nitrogen utilization (ENU) in plots of 6,25 m2, were estimated from October 2004 to October 2005. In the months of January, June/July and September/October samples were collected to determine chemical composition and digestibility such as: crude protein (CP), neutral-detergent fiber (NDF) and in vitro dry matter digestibility (IVDMD). The Irrigation when increased DMP and ENU, reduced the forrage quality and only had significative effect (P<0,05) during the rainy season. The harvest intervals does not affected (P>0,05) on DMP. However, there was tendency to increase. Harvest intervals should be 42/49 days to obtain good forage quality and yield. The chemical composition and digestibility of the dry matter decreased with the spacing of the cuts and the effect of the interval of cuts on ENU was dependent of the irrigation. At that time it dries the irrigated treatments had her ENU increased with the decrease of the frequency of the cut. The nitrogen fertilization was the only factor that increased (P<0,05) DMP and the quality of the stargrass. However, the answer of DMP to the nitrogen fertilization was reduced and ENU was not affected in function of the nitrogen levels. In the conditions of experiment was realized, it is approved as the most appropriate handling of the studied factors: The interval of cuts of 42/49 days, that formed an alliance high yield with a satisfactory quality and the irrigation, only accomplished in favorable climatic conditions. / Este trabalho foi conduzido no munic?pio de Valen?a - RJ, com o objetivo de avaliar a produ??o e a qualidade do capim-estrela, em fun??o de: dois regimes h?dricos (irrigado e n?o-irrigado); quatro intervalos de cortes (21, 28, 35 e 42 na ?poca chuvosa e 28, 35, 42 e 49 dias na ?poca seca do ano); e quatro doses de nitrog?nio (0, 150, 300 e 600 kg/ha/ano). Durante o per?odo de outubro de 2004 a outubro de 2005, foram estimadas a produ??o de mat?ria seca (PMS) e a efici?ncia da aduba??o nitrogenada (EAN) em parcelas de 6,25 m2. Nos meses de janeiro, junho/julho e setembro/outubro coletaram-se amostras para a estimativa do valor nutritivo e digestibilidade, determinando a prote?na bruta (PB), a fibra em detergente neutro (FDN) e a digestibilidade in vitro da mat?ria seca (DIVMS). Os resultados mostraram que a irriga??o aumentou a PMS e a EAN, reduziu o valor nutritivo e DIV da mat?ria seca. Entretanto somente houve resposta (P<0,05) ao regime h?drico apenas quando as condi??es clim?ticas n?o foram limitantes ao crescimento da forrageira. O intervalo de cortes n?o alterou (P>0,05) a PMS, embora tenha sido observada a tend?ncia de incremento da mesma em fun??o da diminui??o da freq??ncia de cortes, sendo a maior produ??o obtida nos tratamentos 42/49 dias. A qualidade da forrageira diminuiu com o espa?amento dos cortes e o efeito do intervalo de cortes sobre a EAN foi dependente da irriga??o. Na ?poca seca do ano os tratamentos irrigados tiveram sua EAN aumentada com a diminui??o da freq??ncia do corte. A aduba??o nitrogenada foi o ?nico fator que aumentou (P<0,05), simultaneamente, a PMS e a qualidade do capim-estrela. No entanto, a resposta da PMS ? aduba??o nitrogenada foi pequena e a EAN n?o foi alterada (P>0,05) em fun??o das doses de nitrog?nio. Nas condi??es experimentais, preconiza-se como o manejo mais adequado: o intervalo de cortes de 42/49 dias, que aliou rendimentos elevados a uma qualidade satisfat?ria; e a irriga??o deve ser usada apenas quando as condi??es clim?ticas s?o favor?veis.