Mitigation of methane and nitrous oxide emissions from flood-irrigated rice by no incorporation of winter crop residues into the soil

Winter cover crops are sources of C and N in flooded rice production systems, but very little is known about the effect of crop residue management and quality on soil methane (CH4) and nitrous oxide (N2O) emissions. This study was conducted in pots in a greenhouse to evaluate the influence of crop residue management (incorporated into the soil or left on the soil surface) and the type of cover-crop residues (ryegrass and serradella) on CH4 and N2O emissions from a flooded Albaqualf soil cultivated with rice (Oryza sativa L.). The closed chamber technique was used for air sampling and the CH4 and N2O concentrations were analyzed by gas chromatography. Soil solution was sampled at two soil depths (2 and 20 cm), simultaneously to air sampling, and the contents of dissolved organic C (DOC), NO3-, NH4+, Mn2+, and Fe2+ were analyzed. Methane and N2O emissions from the soil where crop residues had been left on the surface were lower than from soil with incorporated residues. The type of crop residue had no effect on the CH4 emissions, while higher N2O emissions were observed from serradella (leguminous) than from ryegrass, but only when the residues were left on the soil surface. The more intense soil reduction verified in the deeper soil layer (20 cm), as evidenced by higher contents of reduced metal species (Mn2+ and Fe2+), and the close relationship between CH4 emission and the DOC contents in the deeper layer indicated that the sub-surface layer was the main CH4 source of the flooded soil with incorporated crop residues. The adoption of management strategies in which crop residues are left on the soil surface is crucial to minimize soil CH4 and N2O emissions from irrigated rice fields. In these production systems, CH4 accounts for more than 90 % of the partial global warming potential (CH4+N2O) and, thus, should be the main focus of research.

Fact Sheet: Winter Driving, 2011

The leading cause of death during winter storms is transportation accidents. Preparing your vehicle for the winter season and knowing how to react if stranded or lost on the road are the keys to safe winter driving.

Safety and Mobility Impacts of Winter Weather – Phase I, August 2011

Highway agencies spend millions of dollars to ensure safe and efficient winter travel. However, the effectiveness of winter weather maintenance practices on safety and mobility are somewhat difficult to quantify. Phase I of this project investigated opportunities for improving traffic safety on state-maintained roads in Iowa during winter weather conditions. The primary objective was to develop several preliminary means for the Iowa Department of Transportation (DOT) to identify locations of possible interest systematically with respect to winter weather-related safety performance based on crash history. Specifically, metrics were developed to assist in identifying possible habitual, winter weather-related crash sites on state-maintained rural highways in Iowa. In addition, the current state of practice, for both domestic and international highway agency practices, regarding integration of traffic safety- and mobility-related data in winter maintenance activities and performance measures were investigated. This investigation also included previous research efforts. Finally, a preliminary work plan, focusing on systematic use of safety-related data in support of winter maintenance activities and site evaluation, was prepared.

Mobility and Safety Impacts of Winter Storm Events in a Freeway Environment Final Report, February 2000

Several factors influence a driver’s decision to travel, choice of vehicle speed, and the safety of a particular trip. These factors include, among others, the trip purpose, time of day, traffic volumes, weather and roadway conditions, and the range of vehicle speeds on the roadway. The main goal of the research project summarized in this report was the investigation of winter storm event impacts on the volume, safety, and speed characteristics of interstate traffic flow.

Regular wave propagation out of noise in chemical active media

A pacemaker, regularly emitting chemical waves, is created out of noise when an excitable photosensitive Belousov-Zhabotinsky medium, strictly unable to autonomously initiate autowaves, is forced with a spatiotemporal patterned random illumination. These experimental observations are also reproduced numerically by using a set of reaction-diffusion equations for an activator-inhibitor model, and further analytically interpreted in terms of genuine coupling effects arising from parametric fluctuations. Within the same framework we also address situations of noise-sustained propagation in subexcitable media.

Forms of inorganic phosphorus in soil under different long term soil tillage systems and winter crops

The cultivation of crops with different capacity of P uptake and use under long-term soil tillage systems can affect the distribution of P cycling and inorganic forms in the soil, as a result of higher or lower use efficiency of P applied in fertilizers. The purpose of this study was to evaluate the effect of long-term cultivation of different winter species under tillage systems on the distribution of inorganic P forms in the soil. In 1986, the experiment was initiated with six winter crops (blue lupin, hairy vetch, oat, oilseed radish, wheat and fallow) on a Rhodic Hapludox in southwestern Paraná, under no-tillage (NT) and conventional tillage (CT). The application of phosphate fertilizer in NT rows increased inorganic P in the labile and moderately labile forms, and soil disturbance in CT redistributed the applied P in the deeper layers, increasing the moderately labile P concentration in the subsurface layers. Black oat and blue lupin were the most efficient P-recyclers and under NT, they increased the labile P content in the soil surface layers.

Immunization Update, Winter 2011

Monthly newsletter for the Iowa Department of Public Health

Iowa EHDI News, Winter 2008

Program newsletter used to communicate with parents and professionals about newborn hearing screening in Iowa, including best practice and family stories.

Iowa EHDI News, Winter 2009

Program newsletter used to communicate with parents and professionals about newborn hearing screening in Iowa, including best practice and family stories.

Iowa EHDI News, Winter 2010

Program newsletter used to communicate with parents and professionals about newborn hearing screening in Iowa, including best practice and family stories.

Tobramycin exposure from active calcium sulfate bone graft substitute.

BACKGROUND: Bone graft substitute such as calcium sulfate are frequently used as carrier material for local antimicrobial therapy in orthopedic surgery. This study aimed to assess the systemic absorption and disposition of tobramycin in patients treated with a tobramycin-laden bone graft substitute (Osteoset® T). METHODS: Nine blood samples were taken from 12 patients over 10 days after Osteoset® T surgical implantation. Tobramycin concentration was measured by fluorescence polarization. Population pharmacokinetic analysis was performed using NONMEM to assess the average value and variability (CV) of pharmacokinetic parameters. Bioavailability (F) was assessed by equating clearance (CL) with creatinine clearance (Cockcroft CLCr). Based on the final model, simulations with various doses and renal function levels were performed. (ClinicalTrials.gov number, NCT01938417). RESULTS: The patients were 52 +/- 20 years old, their mean body weight was 73 +/- 17 kg and their mean CLCr was 119 +/- 55 mL/min. Either 10 g or 20 g Osteoset® T with 4% tobramycin sulfate was implanted in various sites. Concentration profiles remained low and consistent with absorption rate-limited first-order release, while showing important variability. With CL equated to CLCr, mean absorption rate constant (ka) was 0.06 h-1, F was 63% or 32% (CV 74%) for 10 and 20 g Osteoset® T respectively, and volume of distribution (V) was 16.6 L (CV 89%). Simulations predicted sustained high, potentially toxic concentrations with 10 g, 30 g and 50 g Osteoset® T for CLCr values below 10, 20 and 30 mL/min, respectively. CONCLUSIONS: Osteoset® T does not raise toxicity concerns in subjects without significant renal failure. The risk/benefit ratio might turn unfavorable in case of severe renal failure, even after standard dose implantation.

Neurogenic subventricular zone stem/progenitor cells are notch1-dependent in their active but not quiescent state.

The adult mammalian forebrain contains neural stem/progenitor cells (NSCs) that generate neurons throughout life. As in other somatic stem cell systems, NSCs are proposed to be predominantly quiescent and proliferate only sporadically to produce more committed progeny. However, quiescence has recently been shown not to be an essential criterion for stem cells. It is not known whether NSCs show differences in molecular dependence based on their proliferation state. The subventricular zone (SVZ) of the adult mouse brain has a remarkable capacity for repair by activation of NSCs. The molecular interplay controlling adult NSCs during neurogenesis or regeneration is not clear but resolving these interactions is critical in order to understand brain homeostasis and repair. Using conditional genetics and fate mapping, we show that Notch signaling is essential for neurogenesis in the SVZ. By mosaic analysis, we uncovered a surprising difference in Notch dependence between active neurogenic and regenerative NSCs. While both active and regenerative NSCs depend upon canonical Notch signaling, Notch1-deletion results in a selective loss of active NSCs (aNSCs). In sharp contrast, quiescent NSCs (qNSCs) remain after Notch1 ablation until induced during regeneration or aging, whereupon they become Notch1-dependent and fail to fully reinstate neurogenesis. Our results suggest that Notch1 is a key component of the adult SVZ niche, promoting maintenance of aNSCs, and that this function is compensated in qNSCs. Therefore, we confirm the importance of Notch signaling for maintaining NSCs and neurogenesis in the adult SVZ and reveal that NSCs display a selective reliance on Notch1 that may be dictated by mitotic state.