Key Components of Healthy Soils and Their Role in Crop Production

Soil health is a confusing term that means different things to different people. To a crop producer, healthy soils are critical for good crop growth and yield. Some soil properties include soil texture, such as the relative percentage of sand, silt and clay; the water content; nutrient levels; organic carbon content; the microbial community; and microbial activity. These properties are determinants of soil health. Our research confirmed that changes in soil management affect the composition and activity of soil microorganisms in surface soils. Greater concentrations of microbial biomass and arbuscular mycorrhizal fungus (AMF) in the no-till agricultural system indicated healthier soils in this system. Our research also indicated microbial properties in subsurface soils were determined by parent materials and weathering

Soil Microbial Activity with Depth in Claypan Soils of Southeast Kansas

Enzyme activities in soil indicate the relative activities of microbes, which include bacteria, fungi, algae, and other organisms. Changes in soil management alter the composition and activity of soil microbes. Plants rely on soil microbes to break down soil nutrients, and make those nutrients available for plant growth. Symbiotic relationships between soil microbes and plants enhance plant growth and productivity. Alternatively, antagonistic relationships between the soil microbial community and plants limit plant production. Soil dwellers such as nematodes or disease-causing fungi such as Macrophomina phaseolina (the fungus responsible for charcoal rot) can be particularly deleterious to crop growth and yield. Changes in the soil microbial community impact crop performance through the synergistic or antagonistic relationships between crop plants and soil biological activity. Our research is designed to explore soil microbial activity, assess changes in the potential activities of hydrolytic and oxidative enzymes involved in nutrient acquisition in the soil, and determine their potential impact on the productive capacity of soil

KLHL1 Controls CaV3.2 Expression in DRG Neurons and Mechanical Sensitivity to Pain

Dorsal root ganglion (DRG) neurons process pain signaling through specialized nociceptors located in their peripheral endings. It has long been established low voltage-activated (LVA) CaV3.2 calcium channels control neuronal excitability during sensory perception in these neurons. Silencing CaV3.2 activity with antisense RNA or genetic ablation results in anti-nociceptive, anti-hyperalgesic and anti-allodynic effects. CaV3.2 channels are regulated by many proteins (Weiss and Zamponi, 2017), including KLHL1, a neuronal actin-binding protein that stabilizes channel activity by recycling it back to the plasma membrane through the recycling endosome. We explored whether manipulation of KLHL1 levels and thereby function as a CaV3.2 modifier can modulate DRG excitability and mechanical pain transmission or sensitivity to pain. We first assessed the mechanical sensitivity threshold and DRG properties in the KLHL1 KO mouse model. KO DRG neurons exhibited smaller T-type current density compared to WT without significant changes in voltage dependence, as expected in the absence of its modulator. Western blot analysis confirmed CaV3.2 but not CaV3.1, CaV3.3, CaV2.1, or CaV2.2 protein levels were significantly decreased; and reduced neuron excitability and decreased pain sensitivity were also found in the KLHL1 KO model. Analogously, transient down-regulation of KLHL1 levels in WT mice with viral delivery of anti-KLHL1 shRNA also resulted in decreased pain sensitivity. These two experimental approaches confirm KLHL1 as a physiological modulator of excitability and pain sensitivity, providing a novel target to control peripheral pain.Fil: Martínez Hernández, Elizabeth. Loyola University Chicago; Estados UnidosFil: Zeglin, Alissa. Loyola University Chicago; Estados UnidosFil: Almazan, Erik. Loyola University Chicago; Estados UnidosFil: Perissinotti, Paula Patricia. Loyola University Chicago; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; ArgentinaFil: He, Yungui. University of Minnesota; Estados UnidosFil: Koob, Michael. University of Minnesota; Estados UnidosFil: Martin, Jody L.. Loyola University Chicago; Estados UnidosFil: Piedras-Rentería, Erika S.. Loyola University Chicago; Estados Unido

Soil Health Profile in Claypan Soils

Healthy soil is the foundation of a sustainable agronomic production system. Microorganisms include bacteria (such as actinomycetes), fungi, and protozoa. Soil microorganisms, or microbes, exist in large numbers in soils and are critical for decomposition of organic residues and nutrient recycling. Soils with ample and diverse microbial populations can provide more essential nutrients for crop growth and development. Soil microbial properties are considered one of the major indicators of soil health. Soil microbial properties can be measured by the activity and the composition of micro-organism populations. Phospholipid fatty acids (PLFA) are the primary components of cell membranes, they can be used to estimate the total amount, or biomass, of bacterial and fungal microbes in the soil. The assay measures the amount of phospholipid fatty acids per weight of soil (nmol PLFA/g soil) and is expressed as the PLFA microbial biomass. Microorganisms within the soil release enzymes that degrade organic material to release nutrients needed to support the microbial community. These nutrients are also used to support plant growth. One of the major groups of soil enzymes, hydrolases, decomposes soil material to release carbon, nitrogen, and phosphorus. By measuring the enzymatic activity of these hydrolases within the soil profile, calculated as the amount of substrate decomposed over time for a given weight of soil (nmol/hr/g soil), we can determine the activity of the microbial community. Claypan soils have a dense, impermeable subsoil that impedes root system development. The soils can be productive, but the productive capacity is often limited by shallow topsoil depth. The poorly drained clayey layer saturates the surface soils, impairs root growth, and exacerbates soil erosion compared to well-drained soils. Crop production on claypan soils requires careful management to maintain productive capacity. It is important to understanding the role of soil microbial properties integrated with soil physical and chemical properties to provide optimal management practices in claypan soils. Little is known about soil microbial properties in claypan soils or how the textural changes in claypan soils impact microbial activity and communities. In this report, we present how management practices influenced soil microbial properties and describe how soil texture mediates changes in soil microbial properties with depth in claypan soil

Changes in Soil Microbiology Under Conventional and No-Till Production During Crop Rotation

Soil microbial activity is important for crop production. Soil microbes are involved in nutrient and water cycling within the soil, and interact with crop plants to provide the basic nutrient and water resources needed for crop production. Claypan soils have unique physical characteristics that impact soil biology. This study explored the tempo­ral changes in soil microbiology in a claypan soil under conventional and no-till produc­tion during a crop rotation of corn/winter wheat/soybean/fallow commonly planted in southeast Kansas. We found soil microbial activity changed more in the top two inches of soil than in the lower soil layers. Wheat resulted in higher soil microbial activity and biomass than corn. Soybeans had a more stable microbial activity in the soil than either corn or wheat. The no-till plots had greater microbial biomass and activity than conventionally tilled systems, and the temporal changes in soil microbial properties were more apparent in no-till plots. These results offer an interesting insight into the soil biological properties that impact soil health for crop production

Thinking outside the channel : modeling nitrogen cycling in networked river ecosystems

Author Posting. © Ecological Society of America, 2011. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Frontiers in Ecology and the Environment 9 (2011): 229–238, doi:10.1890/080211.Agricultural and urban development alters nitrogen and other biogeochemical cycles in rivers worldwide. Because such biogeochemical processes cannot be measured empirically across whole river networks, simulation models are critical tools for understanding river-network biogeochemistry. However, limitations inherent in current models restrict our ability to simulate biogeochemical dynamics among diverse river networks. We illustrate these limitations using a river-network model to scale up in situ measures of nitrogen cycling in eight catchments spanning various geophysical and land-use conditions. Our model results provide evidence that catchment characteristics typically excluded from models may control river-network biogeochemistry. Based on our findings, we identify important components of a revised strategy for simulating biogeochemical dynamics in river networks, including approaches to modeling terrestrial–aquatic linkages, hydrologic exchanges between the channel, floodplain/riparian complex, and subsurface waters, and interactions between coupled biogeochemical cycles.This research was supported by NSF (DEB-0111410). Additional support was provided by NSF for BJP and SMT (DEB-0614301), for WMW (OCE-9726921 and DEB-0614282), for WHM and JDP (DEB-0620919), for SKH (DEB-0423627), and by the Gordon and Betty Moore Foundation for AMH, GCP, ESB, and JAS, and by an EPA Star Fellowship for AMH

Atomic Resonance and Scattering

Contains reports on two research projects.National Science Foundation (Grant PHY 87-06560)Joint Services Electronics Program (Contract DAAL03-86-K-O002)U.S. Navy - Office of Naval Research (Contract N00014-83-K-0695)National Science Foundation (Grant PHY 86-05893

Hydrological legacy determines the type of enzyme inhibition in a peatlands chronosequence

© 2017 The Author(s). Peatland ecosystems contain one-third of the world's soil carbon store and many have been exposed to drought leading to a loss of carbon. Understanding biogeochemical mechanisms affecting decomposition in peatlands is essential for improving resilience of ecosystem function to predicted climate change. We investigated biogeochemical changes along a chronosequence of hydrological restoration (dry eroded gully, drain-blocke

Combination therapy in hypertension: An update

Meticulous control of blood pressure is required in patients with hypertension to produce the maximum reduction in clinical cardiovascular end points, especially in patients with comorbidities like diabetes mellitus where more aggressive blood pressure lowering might be beneficial. Recent clinical trials suggest that the approach of using monotherapy for the control of hypertension is not likely to be successful in most patients. Combination therapy may be theoretically favored by the fact that multiple factors contribute to hypertension, and achieving control of blood pressure with single agent acting through one particular mechanism may not be possible. Regimens can either be fixed dose combinations or drugs added sequentially one after other. Combining the drugs makes them available in a convenient dosing format, lower the dose of individual component, thus, reducing the side effects and improving compliance. Classes of antihypertensive agents which have been commonly used are angiotensin receptor blockers, thiazide diuretics, beta and alpha blockers, calcium antagonists and angiotensin-converting enzyme inhibitors. Thiazide diuretics and calcium channel blockers are effective, as well as combinations that include renin-angiotensin-aldosterone system blockers, in reducing BP. The majority of currently available fixed-dose combinations are diuretic-based. Combinations may be individualized according to the presence of comorbidities like diabetes mellitus, chronic renal failure, heart failure, thyroid disorders and for special population groups like elderly and pregnant females