bluuebunny/crossref_metadata_2025 huggingface dataset:
Enzymatic Hydrolysis of Organic Phosphorus in Swine Manure and Soil
Authors: He Zhongqi , Griffin Timothy S. , Honeycutt C. Wayne
Published: July 2013

Organic phosphorus (Po) exists in many chemical forms that differ in their susceptibility to hydrolysis and, therefore, bioavailability to plants and microorganisms. Identification and quantification of these forms may significantly contribute to effective agricultural P management. Phosphatases catalyze reactions that release orthophosphate (Pi) from Po compounds. Alkaline phosphatase in tris‐HCl buffer (pH 9.0), wheat (Triticum aestivum L.) phytase in potassium acetate buffer (pH 5.0), and nuclease P1 in potassium acetate buffer (pH 5.0) can be used to classify and quantify Po in animal manure. Background error associated with different pH and buffer systems is observed. In this study, we improved the enzymatic hydrolysis approach and tested its applicability for investigating Po in soils, recognizing that soil and manure differ in numerous physicochemical properties. We applied (i) acid phosphatase from potato (Solanum tuberosum L.), (ii) acid phosphatases from both potato and wheat germ, and (iii) both enzymes plus nuclease P1 to identify and quantify simple labile monoester P, phytate (myo‐inositol hexakis phosphate)‐like P, and DNA‐like P, respectively, in a single pH/buffer system (100 mM sodium acetate, pH 5.0). This hydrolysis procedure released Po in sequentially extracted H2O, NaHCO3, and NaOH fractions of swine (Sus scrofa) manure, and of three sandy loam soils. Further refinement of the approach may provide a universal tool for evaluating hydrolyzable Po from a wide range of sources.
Field Studies on Exposure, Effects, and Risk Mitigation of Aquatic Nonpoint‐Source Insecticide Pollution: A Review
Authors: Schulz Ralf
Published: July 2013

Recently, much attention has been focused on insecticides as a group of chemicals combining high toxicity to invertebrates and fishes with low application rates, which complicates detection in the field. Assessment of these chemicals is greatly facilitated by the description and understanding of exposure, resulting biological effects, and risk mitigation strategies in natural surface waters under field conditions due to normal farming practice. More than 60 reports of insecticide‐compound detection in surface waters due to agricultural nonpoint‐source pollution have been published in the open literature during the past 20 years, about one‐third of them having been undertaken in the past 3.5 years. Recent reports tend to concentrate on specific routes of pesticide entry, such as runoff, but there are very few studies on spray drift–borne contamination. Reported aqueous‐phase insecticide concentrations are negatively correlated with the catchment size and all concentrations of >10 μg/L (19 out of 133) were found in smaller‐scale catchments (<100 km2). Field studies on effects of insecticide contamination often lack appropriate exposure characterization. About 15 of the 42 effect studies reviewed here revealed a clear relationship between quantified, non‐experimental exposure and observed effects in situ, on abundance, drift, community structure, or dynamics. Azinphos‐methyl, chlorpyrifos, and endosulfan were frequently detected at levels above those reported to reveal effects in the field; however, knowledge about effects of insecticides in the field is still sparse. Following a short overview of various risk mitigation or best management practices, constructed wetlands and vegetated ditches are described as a risk mitigation strategy that have only recently been established for agricultural insecticides. Although only 11 studies are available, the results in terms of pesticide retention and toxicity reduction are very promising. Based on the reviewed literature, recommendations are made for future research activities.
Dissolved Organic Carbon and Disinfection By‐Product Precursor Release from Managed Peat Soils
Authors: Fleck J. A. , Bossio D. A. , Fujii R.
Published: July 2013

A wetland restoration demonstration project examined the effects of a permanently flooded wetland on subsidence of peat soils. The project, started in 1997, was done on Twitchell Island, in the Sacramento–San Joaquin Delta of California. Conversion of agricultural land to a wetland has changed many of the biogeochemical processes controlling dissolved organic carbon (DOC) release from the peat soils, relative to the previous land use. Dissolved organic C in delta waters is a concern because it reacts with chlorine, added as a disinfectant in municipal drinking waters, to form carcinogenic disinfection by‐products (DBPs), including trihalomethanes (THMs) and haloacetic acids (HAAs). This study explores the effects of peat soil biogeochemistry on DOC and DBP release under agricultural and wetland management. Results indicate that organic matter source, extent of soil organic matter decomposition, and decomposition pathways all are factors in THM formation. The results show that historical management practices dominate the release of DOC and THM precursors. However, within‐site differences indicate that recent management decisions can contribute to changes in DOC quality and THM precursor formation. Not all aromatic forms of carbon are highly reactive and certain environmental conditions produce the specific carbon structures that form THMs. Both HAA and THM precursors are elevated in the DOC released under wetland conditions. The findings of this study emphasize the need to further investigate the roles of organic matter sources, microbial decomposition pathways, and decomposition status of soil organic matter in the release of DOC and DBP precursors from delta soils under varying land‐use practices.
Changes in Ground Water Quality in an Irrigated Area of Southern Alberta
Authors: Rodvang S. J. , Mikalson D. M. , Ryan M. C.
Published: July 2013

Few studies have documented spatial and temporal variations in ground water quality in areas with high densities of animal farming operations (AFOs), or the long‐term effects on surface‐water quality. Changes in ground water quality were characterized in an irrigated area with a high density of AFOs in southern Alberta, Canada to evaluate the effect on ground water quality of manure application to fields. Fifty‐five piezometers in the oxidized zone were sampled once or twice annually from 1995 to 2001, and temporal changes were analyzed using mixed model analysis. Average NO3−–N increased significantly from 12.5 to 17.4 mg L−1 and average Cl− increased significantly from 19.4 to 34.4 mg L−1 in piezometers installed in an unconfined sand aquifer at locations receiving fertilizer and manure. Compared with these manured locations, nitrate and chloride concentrations were significantly lower in shallow aquifer water in areas of pasture or native range, and concentrations did not change significantly with time. Nitrate and chloride concentrations in shallow ground water in fine‐textured manured locations did not change significantly. Ground water below about 6 m in till and fine lacustrine sediments contains 18O signatures indicative of recharge under pre‐irrigation or glacially influenced conditions, suggesting this ground water has a low vulnerability to agricultural contamination. Evaluations suggest that shallow ground water discharge will cause NO3−–N and Cl− in the Oldman River to increase by factors of at least 4.3 and 1.3, respectively, with more significant effects in smaller streams and under low‐flow conditions.
Effect of Chloride in Soil Solution on the Plant Availability of Biosolid‐Borne Cadmium
Authors: Weggler Karin , McLaughlin Michael J. , Graham Robin D.
Published: July 2013

Increasing chloride (Cl) concentration in soil solution has been shown to increase cadmium (Cd) concentration in soil solution and Cd uptake by plants, when grown in phosphate fertilizer– or biosolid‐amended soils. However, previous experiments did not distinguish between the effect of Cl on biosolid‐borne Cd compared with soil‐borne Cd inherited from previous fertilizer history. A factorial pot experiment was conducted with biosolid application rates of 0, 20, 40, and 80 g biosolids kg−1 and Cl concentration in soil solution ranging from 1 to 160 mM Cl. The Cd uptake of wheat (Triticum aestivum L. cv. Halberd) was measured and major cations and anions in soil solution were determined. Cadmium speciation in soil solution was calculated using GEOCHEM‐PC. The Cd concentration in plant shoots and soil solution increased with biosolid application rates up to 40 g kg−1, but decreased slightly in the 80 g kg−1 biosolid treatment. Across biosolid application rates, the Cd concentration in soil solution and plant shoots was positively correlated with the Cl concentration in soil solution. This suggests that biosolid‐borne Cd is also mobilized by chloride ligands in soil solution. The soil solution CdCl+ activity correlated best with the Cd uptake of plants, although little of the variation in plant Cd concentrations was explained by activity of CdCl+ in higher sludge treatments. It was concluded that chloro‐complexation of Cd increased the phytoavailability of biosolid‐borne Cd to a similar degree as soil (fertilizer) Cd. There was a nonlinear increase in plant uptake and solubility of Cd in biosolid‐amended soils, with highest plant Cd found at the 40 g kg−1 rate of biosolid application, and higher rates (80 g kg−1) producing lower plant Cd uptake and lower Cd solubility in soil. This is postulated to be a result of Cd retention by CaCO3 formed as a result of the high alkalinity induced by biosolid application.
Time and Moisture Effects on Total and Bioavailable Copper in Soil Water Extracts
Authors: Tom‐Petersen Andreas , Hansen Hans Christian Bruun , Nybroe Ole
Published: July 2013

Environmental risk assessment of heavy metals in soil frequently involves testing of freshly spiked soils kept under stable humidity conditions, but it has been questioned whether these assessments are representative of the field situation. Furthermore, the poor correspondence that is often found between total metal content and metal toxicity calls for integrated chemical and biological analysis. The aim of this work was to determine time‐ and moisture‐dependent changes in total water‐extractable Cu as well as bioavailable Cu in soil water extracts. Measurements of total water‐extractable copper ([Cu]tot) were performed using furnace atomic absorption spectrometry. An in vitro assay employing a Cu‐specificPseudomonas fluorescensreporter strain was used to estimate Cu that was biologically available to the reporter strain. We refer to this copper fraction as “bioavailable,” [Cu]bioWe found a time‐dependent decrease in [Cu]totand [Cu]bioduring incubation for up to 220 d at field capacity. Hence the [Cu]biowas reduced to between 32 and 40% of the initial values. Furthermore, the [Cu]bioto [Cu]totratio correlated positively with the amount of added Cu and tended to increase with time. The moisture content of the soil was important for Cu retention. Dry soil had higher [Cu]totconcentrations than humid soil, but the [Cu]bioto [Cu]totratio was lower in the dry soil. Alternating drying and wetting did not lead to a more rapid Cu retention than observed under constant humid conditions. Our observations underline the need for considering both time and moisture effects when interpreting short‐term toxicity studies and when making predictions concerning possible long‐term effects of Cu in the soil environment.
In Situ Soil Treatments to Reduce the Phyto‐ and Bioavailability of Lead, Zinc, and Cadmium
Authors: Brown Sally , Chaney Rufus , Hallfrisch Judith , Ryan James A. , Berti William R.
Published: July 2013

A study was established near a former Zn and Pb smelter to test the ability of soil amendments to reduce the availability of Pb, Zn, and Cd in situ. Soil collected from the field was amended in the lab with P added as 1% P‐H3PO4, biosolids compost added at 10% (referred to hereafter as “compost”), and a high‐Fe by‐product (referred to hereafter as “Fe”) + P‐triple superphosphate (TSP) (2.5% Fe + 1% P‐TSP) and incubated under laboratory conditions at a constant soil pH. Changes in Pb bioavailability were measured with an in vitro test and a feeding study with weanling rats. Field‐amended and incubated soils using these plus additional treatments were evaluated using the in vitro extraction and tall fescue (Festuca arundinacea Schreb. cv. Kentucky‐31) metal concentration. Reductions were observed across all parameters but were not consistent. In the feeding study, the 1% P‐H3PO4 and compost treatments resulted in a decrease of 26% in rat tissue Pb concentration compared with the control soil. The 2.5% Fe + 1% P‐TSP showed a 39% decrease. The 1% P‐H3PO4 treatment caused the greatest reduction in in vitro extractable Pb from field samples (pH 2.2) with a measured reduction of 66%, while the compost treatment had a 39% reduction and the 2.5% Fe + 1% P‐TSP treatment a 50% reduction. The in vitro extraction (pH 1.5) run on field samples showed no reduction in the compost or Fe treatments. The 1% P‐H3PO4 treatment was the most effective at reducing plant Pb, Zn, and Cd.
Fertilizer Source Effect on Ground and Surface Water Quality in Drainage from Turfgrass
Authors: Easton Zachary M. , Petrovic A. Martin
Published: July 2013

Nutrients in surface and ground water can affect human and aquatic organisms that rely on water for consumption and habitat. A mass‐balance field study was conducted over two years (July 2000–May 2001) to determine the effect of nutrient source on turfgrass runoff and leachate. Treatments were arranged in an incomplete randomized block design on a slope of 7 to 9% of Arkport sandy loam (coarse‐loamy, mixed, active, mesic Lamellic Hapludalf) and seeded with Kentucky bluegrass (Poa pratensis L.) and perennial ryegrass (Lolium perenne L.). Three natural organic (dairy and swine compost and a biosolid) and two synthetic organic nutrient sources (readily available urea and controlled‐release N source sulfur‐coated urea) were applied at rates of 50 and 100 kg N ha−1 per application (200 kg ha−1 yr−1). Runoff water collected from 33 storms and composite monthly leachate samples collected with ion exchange resins were analyzed for nitrate (NO−3–N), phosphate (PO3−4–P), and ammonium (NH+4–N). Nutrient concentrations and losses in both runoff and leachate were highest for the 20‐wk period following turfgrass seeding. The NO−3–N and NH+4–N losses declined significantly once turfgrass cover was established, but PO3−4–P levels increased in Year 2. Turf's ability to reduce nutrient runoff and leachate was related to overall plant growth and shoot density. The use of natural organics resulted in greater P loss on a percent applied P basis, while the more soluble synthetic organics resulted in greater N loss.
Use of Commercial Plant Species in a Hydroponic System to Treat Domestic Wastewaters
Authors: Vaillant Nathalie , Monnet Fabien , Sallanon Huguette , Coudret Alain , Hitmi Adnane
Published: July 2013

The objectives in this work were to investigate a conceptual layout for an inexpensive and simple system that would treat primary municipal wastewater to discharge standards. A commercial hydroponic system was adapted for this study and the wastewater was used to irrigate wooly digitalis (Digitalis lanata Ehrh.) and foxglove (Digitalis purpurea L.). These plants are medicinal and produce cardenolide compounds. Influent and effluent samples were collected once a month for six months and analyzed to determine the various parameters relating to water quality. The legal discharge levels for total suspended solids (SS), biochemical oxygen demand (BOD5), and chemical oxygen demand (COD) were reached for the two tested plants after 48 h of wastewater treatment; the removal was 82, 93, and 79%, respectively, for wooly digitalis and 92, 92, and 84%, respectively, for foxglove. Similar results were obtained during a 6‐mo period although the sewage composition varied widely. The system tended to be unable to remove N and P to concentrations below regulated levels. Compared with the nutrient solution composition, the wastewater was more concentrated in Na+ and Cl− and less in N, K+, and Ca2+ These variations can lead to the decline of wooly digitalis plants. Foxglove developed a significant root system to increase mineral absorption wastewater being used as the unique nutritive source. After 10 wk all the wooly digitalis seedlings were dead. Despite this fact, however, the root system remained in place for a significant time (<4 mo), thus continuing to filter wastewater and to be used as a bacterial support thus making it possible to have a security period to replace the dead plants.
Environmental Factors Influencing Attenuation of Methane and Hydrochlorofluorocarbons in Landfill Cover Soils
Authors: Scheutz Charlotte , Kjeldsen Peter
Published: July 2013

The influence of different environmental factors on methane oxidation and degradation of hydrochlorofluorocarbons (HCFCs) was investigated in microcosms containing soil sampled at Skellingsted Landfill, Denmark. The soil showed a high capacity for methane oxidation resulting in a maximum oxidation rate of 104 μg CH4 g−1 h−1 and a low affinity of methane with a half‐saturation constant of 2.0% v/v. The hydrochlorofluorocarbons HCFC‐21 (dichlorofluoromethane) and HCFC‐22 (chlorodifluoromethane) were rapidly oxidized and the oxidation occurred in parallel with the oxidation of methane. The maximal HCFC oxidation rates were 0.95 and 0.68 μg g−1 h−1 for HCFC‐21 and HCFC‐22, respectively. Increasing concentrations of HCFCs resulted in decreased methane oxidation rates. However, compared with typical concentrations in landfill gas, relatively high HCFC concentrations were needed to obtain a significant inhibition of methane oxidation. In general, the environmental factors studied influenced the degradation of HCFCs in almost the same way as they influenced methane oxidation. Temperature had a strong influence on the methanotrophic activity giving high Q10 values of 3.4 to 4.1 over the temperature range of 2 to 25°C. Temperature optimum was around 30°C; however, oxidation occurred at temperatures as low as 2°C. A moisture content of 25% w/w yielded the maximum oxidation rate as it allowed good gas transport together with sufficient microbial activity. The optimum pH was around neutrality (pH = 6.5–7.5) showing that the methanotrophs were optimally adapted to the in situ pH, which was 6.9. Copper showed no inhibitory effect when added in relatively high concentrations (up to 60 mg kg−1), most likely due to sorption of copper ions to soil particles. At higher copper concentrations the oxidation rates decreased. The oxidation rates for methane, HCFC‐21, and HCFC‐22 were unaltered in ammonium‐amended soil up to 14 mg kg−1 Higher ammonium concentrations inhibited the oxidation process. The most important parameters controlling oxidation in landfill cover soil were found to be temperature, soil moisture, and methane and oxygen supply.
Bermudagrass Sod Growth and Metal Uptake in Coal Combustion By‐Product‐Amended Media
Authors: Schlossberg M. J. , Vanags C. P. , Miller W. P.
Published: July 2013

Coal combustion by‐products (CCB) include fly ash and bottom ash and are generated nationally at rates of 108Mg yr−1Land applications of CCB have improved physicochemical properties of soil, yet inherent bulkiness and trace metal content of CCB often limit their use. Likewise, utilization of biosolids and manure as fertilizer can be problematic due to unfavorable nutrient ratios. A 2‐yr field study evaluated environmental and technical parameters associated with CCB–organic waste utilization as growth media in turfgrass sod production. Experimental growth media formulated with CCB and organic waste and a sand–compost control mixture were uniformly spread at rates from 200 to 400 m3ha−1and sprigged with hybrid bermudagrass [Cynodon dactylon(L.) Pers. ×C. transvaalensisBurtt‐Davy]. Leaf clippings were collected and analyzed for total elemental content each year. In Year 2, growth media samples were collected during establishment 47 and 84 days after planting (DAP) and viableEscherichia coliorganisms were quantified. At harvest (99 or 114 DAP), sod biomass and physicochemical properties of the growth media were measured. During sod propagation, micronutrient and metal content in leaf clippings varied by growth media and time. After 47 d of typical sod field management, viableE. colipathogens were detected in only one biosolids‐amended plot. No viableE. coliwere measured at 84 DAP. In both years, sod biomass was greatest in media containing biosolids and fly ash. Following installation of sod, evaluations did not reveal differences by media type or application volume. Using CCB–organic waste mixes at the rates described herein is a rapid and environmentally safe method of bermudagrass sod production.
Optimizing Phosphorus Characterization in Animal Manures by Solution Phosphorus‐31 Nuclear Magnetic Resonance Spectroscopy
Authors: Turner Benjamin L.
Published: July 2013

A procedure involving alkaline extraction and solution 31P nuclear magnetic resonance (NMR) spectroscopy was developed and optimized for the characterization of P in animal manures (broiler, swine, beef cattle). Inclusion of ethylenediaminetetraacetic acid (EDTA) in the alkaline extraction solution recovered between 82 and 97% of the total P from the three manures, which represented a significant improvement on recovery in NaOH alone. Low concentrations of paramagnetic ions in all manure extracts meant that relatively long delay times (>5 s) were required for quantitative analysis by solution 31P NMR spectroscopy. The manures contained inorganic orthophosphate, orthophosphate monoesters, orthophosphate diesters, and inorganic polyphosphates, but results were markedly influenced by the concentration of NaOH in the extractant, which affected both spectral resolution and the apparent P composition of the extracts. For example, extraction of swine manure and broiler litter with 0.5 M NaOH + 50 mM EDTA produced remarkable spectral resolution that allowed accurate quantification of the four signals from phytic acid, the major organic P compound in these manures. In contrast, more dilute NaOH concentrations produced considerable line broadening that obscured individual signals in the orthophosphate monoester region of the spectra. Spectral resolution of cattle manure extracts was relatively unaffected by NaOH concentration. Improvements in spectral resolution of more concentrated NaOH extracts were, however, compromised by the disappearance of phospholipids and inorganic polyphosphates, notably in swine and cattle manure extracts, which indicated either degradation or a change in solubility. The optimum extraction conditions will therefore vary depending on the manure type and the objectives of the study. Phytic acid can be accurately quantified in swine manure and broiler litter by extraction with 0.5 M NaOH + 50 mM EDTA, while a more dilute NaOH concentration should be used for complete P characterization or comparison among different manure types.
Chemical and Carbon‐13 Cross‐Polarization Magic‐Angle Spinning Nuclear Magnetic Resonance Characterization of Logyard Fines from British Columbia
Authors: Preston C. M. , Forrester P. D.
Published: July 2013

Phasing out beehive burners and rising costs for landfilling have increased the need to widen options for utilization of the smaller size fractions of woody wastes generated during log handling and sawmilling in British Columbia. We characterized several size classes of logyard fines up to 16 mm sampled from coastal and interior operations. Total C, total N, ash, and condensed tannin concentrations were consistent with properties derived largely from wood, with varying proportions of bark and mixing with mineral soil. Especially for <3‐mm fractions, the latter resulted in high ash contents that would make them unsuitable for fuel. Solid‐state 13C cross‐polarization magic‐angle spinning (CPMAS) nuclear magnetic resonance (NMR) spectra were consistent with the chemical data, with high O‐alkyl intensity and similarity to naturally occurring woody forest floor; no samples were high in aromatic or phenolic C. Aqueous extracts of two <16‐mm fines, which accounted for only a small proportion of the total C, were enriched in alkyl C and had low or undetectable tannins. Application to forest sites might cause short‐term immobilization of N, but also might include possible longer‐term benefits from reduction of N loss after harvesting and restoration of soil organic matter in degraded sites.
The Relationship of Procrastination with a Mastery Goal Versus an Avoidance Goal
Authors: Seo Eun Hee
Published: July 2013

The purpose of this study was to examine which is more powerful to determine procrastination, a mastery goal or an avoidance goal. A preliminary model and a competitive model were explored by collecting 307 college students' survey results and employing structural equation modeling.
The result of this study showed that procrastination is positively related to mastery avoidance and performance avoidance goal orientations whereas, as predicted, it is negatively related to mastery approach goal orientation. We also found that an avoidance goal is more powerful in determining
students' procrastination than is a mastery goal. Implications of the study are discussed.
A MCNP simulation study of neutronic calculations of spallation targets
Authors: Feghhi Seyed , Gholamzadeh Zohreh
Published: July 2013

The accelerator driven system is an innovative reactor which is being
considered as a dedicated high-level waste burner. The function of the
spallation target in accelerator driven system is to convert the incident
high-energy particle beam to low-energy neutrons. One of the quantities of
most interest for practical purposes is the number of neutrons produced per
proton in a spallation target. However, this vital value depends not only on
the material, but on the size of the target as well, due to the internuclear
cascade. The MCNPX 2.4 code can be used for spallation target computation.
Some benchmark results have been compared with MCNPX 2.4 simulations to
verify the code's potential for calculating various parameters of an
accelerator driven system target. Using the computation method, neutron
interaction processes such as loss, capture and (n, xn) into a spallation
target have been studied for W, Ta, Pb, Bi, and LBE spallation targets in
different target dimensions. With relative errors less than 10%, the
numerical simulation provided by the MCNPX code agrees qualitatively with
other simulation results previously carried out, qualifying it for spallation
calculations. Among the studied targets, W and Ta targets resulted in a
higher neutron spallation yield using lesser target dimensions. Pb, Bi, and
LBE spallation targets behave similarly regarding the accessible leaked
neutron yield on the outer surface of the spallation target. By use of a
thicker target, LBE can compete with both W and Ta targets regarding the
neutron yield parameter.
Power lateral pnp transistor operating with high current density in irradiated voltage regulator
Authors: Vukic Vladimir , Osmokrovic Predrag
Published: July 2013

The operation of power lateral pnp transistors in gamma radiation field was
examined by detection of the minimum dropout voltage on heavily loaded
low-dropout voltage regulators LM2940CT5, clearly demonstrating their low
radiation hardness, with unacceptably low values of output voltage and
collector-emitter voltage volatility. In conjunction with previous results on
base current and forward emitter current gain of serial transistors, it was
possible to determine the positive influence of high load current on a slight
improvement of voltage regulator LM2940CT5 radiation hardness. The
high-current flow through the wide emitter aluminum contact of the serial
transistor above the isolation oxide caused intensive annealing of the
positive oxide-trapped charge, leading to decrease of the lateral pnp
transistor's current gain, but also a more intensive recovery of the
small-signal npn transistors in the control circuit. The high current density
in the base area of the lateral pnp transistor immediately below the
isolation oxide decreased the concentration of negative interface traps.
Consequently, the positive influence of the reduced concentration of the
oxide-trapped charge on the negative feedback reaction circuit, together with
the favourable effect of reduced interface traps concentration, exceeded
negative influence of the annealed oxide-trapped charge on the serial pnp
transistor's forward emitter current gain.
Modeling the impact of uncertainty in detector specification on efficiency values of a HPGe detector using ANGLE software
Authors: Miller Maurice , Voutchkov Mitko
Published: July 2013

The objective of this study is to model the impact of uncertainties in the
engineering specifications of a typical p-type HPGe detector on the
efficiency values when the measured soil sample is in contact geometry with
the detector. We introduce a parameter named the normalized sensitivity
impact which allows a comparative analysis to be made of the impact of the
detector specification uncertainties and develop a correction factor table
for the most important parameters. The areas of the detector most susceptible
to error were found to be the crystal geometry, vacuum layer above the
crystal and the bulletizing radius. In all cases the major impacts were
mathematically modeled - for the first time - and found to vary either
quadratically or logarithmically over the energy range of 180 keV to 1500
keV. Finally, we propose a set of detector characterization values that may
be used in ANGLE for generating a reference efficiency curve using the
efficiency transfer method inherent in this software. These values are to be
used with the understanding that their uncertainty impact on the full-peak
efficiency though not very significant in this counting arrangement, is not
non-zero.
Comparison of three methods used for measurement of radioiodine fixation in thyroid gland of mice
Authors: Jeremic Marija , Matovic Milovan , Jankovic Slobodan , Milosev Milorad , Novakovic Milan , Spasojevic-Tisma Vera , Urosevic Vlade
Published: July 2013

The aim of this work is to compare the results of estimation of radioiodine
uptake using three methods in a study on mice, and to test reliability of the
radioiodine uptake estimation by gamma camera. The study is conducted on 21
white, Swiss-type mice of both sex at age of 10 weeks, weighing between 25 g
and 34 g. The mice were injected intraperitoneally with 0.37 ? ? 0.03 MBq of
radioiodine 131I. After 72 hours the mice were anesthetized, and
radioactivity of thyroid region was measured by gamma camera (the 1st method,
in situ). After the measurement, the animals were sacrificed, their thyroid
glands were carefully excised together with adjacent trachea and placed at
the bottom of a test tube. The radioactivity of the excised tissue was then
measured by both gamma camera (the 2nd method) and gamma counter (the 3rd
method). This method is treated as a standard and the most accurate. In the
study we used Siemens e_cam gamma camera and Wallac Wizard 1470 Automatic
Gamma counter. The radioiodine fixation determined using those three methods
was 25.25 ? 7.32%, 26.08 ? ? 8.55% and 25.74 ? 7.18%, without statisticaly
significant difference s between methods (p > 0.05). The high correlation
between the three methods of measuring radioiodine fixation in thyroid gland
was observed: (1) the correlation coefficient between the fixation rate
obtained by gamma camera in situ and the fixation rate obtained by measuring
the radioactivity of extirpated thyroids by gamma camera was 0.869 (p <
0.01); (2) the correlation coefficient between fixation rate obtained by
gamma camera in situ and the fixation rate obtained by measuring
radioactivity of extirpated thyroids by gamma counter was 0.890 (p < 0.01);
(3) the correlation coefficient between fixation rate obtained by measuring
radioactivity of extirpated thyroids by gamma camera and the fixation rate
obtained by measuring radioactivity of extirpated thyroids by gamma counter
was 0.835 (p < 0.01).
Evidence for Rapamycin Toxicity in Pancreatic β-Cells and a Review of the Underlying Molecular Mechanisms
Authors: Barlow Adam D. , Nicholson Michael L. , Herbert Terry P.
Published: July 2013

Rapamycin is used frequently in both transplantation and oncology. Although historically thought to have little diabetogenic effect, there is growing evidence of β-cell toxicity. This Review draws evidence for rapamycin toxicity from clinical studies of islet and renal transplantation, and of rapamycin as an anticancer agent, as well as from experimental studies. Together, these studies provide evidence that rapamycin has significant detrimental effects on β-cell function and survival and peripheral insulin resistance. The mechanism of action of rapamycin is via inhibition of mammalian target of rapamycin (mTOR). This Review describes the complex mTOR signaling pathways, which control vital cellular functions including mRNA translation, cell proliferation, cell growth, differentiation, angiogenesis, and apoptosis, and examines molecular mechanisms for rapamycin toxicity in β-cells. These mechanisms include reductions in β-cell size, mass, proliferation and insulin secretion alongside increases in apoptosis, autophagy, and peripheral insulin resistance. These data bring into question the use of rapamycin as an immunosuppressant in islet transplantation and as a second-line agent in other transplant recipients developing new-onset diabetes after transplantation with calcineurin inhibitors. It also highlights the importance of close monitoring of blood glucose levels in patients taking rapamycin as an anticancer treatment, particularly those with preexisting glucose intolerance.
Effect of Nasal Anti-Inflammatory Treatment in Chronic Obstructive Pulmonary Disease
Authors: Callebaut Ina , Hox Valérie , Bobic Sonja , Bullens Dominique M.A. , Janssens Wim , Dupont Lieven , Hellings Peter W.
Published: July 2013

Background

Sinonasal inflammation and symptoms are often underdiagnosed in chronic obstructive pulmonary disease (COPD) patients. So far, it is not known to what extent anti-inflammatory nasal treatment may reduce sinonasal symptoms in COPD patients. This study was designed to examine the effects of nasal anti-inflammatory treatment on sinonasal symptoms and cough in COPD patients.

Methods

Thirty-three COPD patients on stable bronchial therapy (salmeterol/fluticasone propionate 50/500 mg b.i.d. for >6 weeks) were randomized to receive fluticasone furoate (FF) or placebo nasal spray at 110 μg once daily for 12 weeks. Sinonasal symptoms and cough were monitored at baseline, at 6 and 12 weeks of treatment, and at 4 weeks after cessation of the treatment using a visual analog scale. Levels of cytokines were measured in nasal secretions.

Results

In contrast to the placebo group (n = 13), FF patients (n = 14) reported less nasal blockage (10.62 ± 4.21 mm versus 36.57 ± 8.01 mm; p = 0.0026), postnasal drip (1.46 ± 0.29 score versus 2.83 ± 0.38 score; p = 0.03), and nasal discharge (0.23 ± 0.12 score versus 1.77 ± 0.43 score; p = 0.01) after 6 weeks of treatment compared with baseline, which was still present at 12 weeks. FF patients reported less cough compared with baseline (25.54 ± 4.46 mm versus 36.79 ± 5.75 mm; p = 0.04), which was not the case in the placebo group (49.58 ± 10.44 mm versus 42.00 ± 8.05 mm; p = 0.38). Nine of 14 patients in the FF group (64%) reported slight to total relief of nasal symptoms, and this subgroup had a significant decrease in IL-8 levels in nasal secretions after 6 weeks of treatment (850.7 ± 207.2 pg/mL versus 1608 ± 696.5 pg/mL; p = 0.03) compared with baseline.

Conclusion

Nasal FF treatment in COPD patients significantly reduced sinonasal symptoms, in parallel with reduced IL-8 in nasal secretion levels and cough.
Olfactory Dysfunction and Asthma as Risk Factors for Poor Quality of Life in Upper Airway Diseases
Authors: Katotomichelakis Michael , Simopoulos Efthimios , Zhang Nan , Tripsianis Gregory , Danielides Gerasimos , Livaditis Miltos , Bachert Claus , Danielides Vassilios
Published: July 2013

Background

The study of olfaction/quality of life (QoL) interaction has not been adequately discussed and remains to be further explored. Determination of clinical predictors for poor QoL may support consultation of respective patients. This study explores QoL of patients with olfactory dysfunction and evaluates associated clinical risk factors for QoL prediction.

Methods

One hundred eight patients suffering from chronic rhinosinusitis (CRS) and allergic rhinitis (AR) and 30 healthy subjects were studied. Olfactory function was evaluated using objective olfactory test. All patients completed six validated questionnaires either specific for olfaction (Questionnaire of Olfactory Deficits [QOD]) and for assessing psychological state (Zung Anxiety Scale [ZAS], State-Trait Anxiety Inventory, Zung Depression Scale, and Beck Depression Inventory [BDI]) or a generic one (Short Form 36).

Results

Significantly poorer QoL and more severe anxiety and depression symptoms were observed in anosmic (all p < 0.001) and hyposmic patients compared with controls. Anosmic patients presented significantly worse results compared with hyposmic and normosmic patients. However, higher scores were observed in hyposmic compared with normosmic patients only in the QOD, ZAS, and BDI scale. Patients with CRS presented significantly poorer QoL than patients with AR only. The presence of nasal polyps or concomitant AR in patients with CRS did not show any differentiation in the results. Asthma was associated with significantly worse scores in all the psychometric questionnaires.

Conclusion

Olfactory dysfunction was found to decrease QoL among patients. Anosmia, CRS disease, and asthma as clinical predictors were proved to be independently correlated with QoL, anxiety, and depression levels.
Sinonasal Respiratory Epithelial Adenomatoid Hamartomas: Series of 51 Cases and Literature Review
Authors: Lee Jivianne T. , Garg Rohit , Brunworth Joseph , Keschner David B. , Thompson Lester D.R.
Published: July 2013

Background

Respiratory epithelial adenomatoid hamartomas (REAHs) are rare, benign glandular proliferations of the nasal cavity, paranasal sinuses, and nasopharynx. This study aimed to expand our understanding of this entity by presenting a series of REAHs combined with a review of the pertinent literature.

Methods

A retrospective review was performed on all patients with a diagnosis of REAH from 2002 to 2011. Data were collected with respect to age, gender, clinical presentation, imaging, histopathology, treatment, and outcome. Because olfactory cleft expansion by imaging evaluation has been reported to suggest REAH, maximum olfactory cleft (MOCs) widths were also measured.

Results

Fifty-one cases of REAH included 37 male (72.5%) and 14 female subjects (27.5%) with a mean age of 58.4 years. Headache, nasal obstruction, rhinorrhea, and hyposmia were the most common presenting symptoms. Although 35(68.6%) were associated with concurrent inflammatory pathology, 16 (31.4%) presented as isolated lesions of the nasal cavity. Enlargement of MOCs was evident on computed tomography, with mean MOCs of 8.64 and 9.4 mm, in the coronal/axial planes, respectively. There were no statistically significant differences between MOCs of isolated (7.96 mm) versus MOCs of associated (9.63 mm) lesions (p = 0.25). Forty-nine were treated with endoscopic resection without evidence of recurrence after a mean follow-up of 27.2 months.

Conclusion

REAHs are rare sinonasal lesions that may appear as localized, isolated masses or more diffuse when in conjunction with other inflammatory processes. Irrespective of clinical presentation, endoscopic removal appears to be curative. Differentiation from more aggressive lesions is paramount to avoid unnecessarily radical surgery for an otherwise benign process.
Does Surgery of the Olfactory Clefts Modify the Sense of Smell?
Authors: Nguyen Duc Trung , Gauchotte Guillaume , Nguyen-Thi Phi-Linh , Jankowski Roger
Published: July 2013

Background

The olfactory outcome after surgery of polyps in the olfactory clefts (OCs) is unknown. This study was designed to (1) investigate the relationship between clinical characteristics and the presence of the respiratory epithelial adenomatoid hamartoma (REAH) in the OCs and (2) assess the olfactory outcome after surgery in the OC for either eosinophilic polyps (EP) or REAH in patients with ethmoidectomy for nasal polyposis (NP).

Methods

Seventy-four patients with NP having undergone nasalization procedure were enrolled in this prospective study. The OCs were systematically examined during endoscopic surgery. Small polyps or edematous mucosa of the OC were systematically biopsied. Moderate or big polyps in the OC were removed after nasalization of the ethmoidal labyrinths. The distinction between REAH and EP relied on histopathological examinations. The olfactory function was measured with standardized odor threshold and identification tests 1 day before and 6 weeks after surgery.

Results

There was a close relationship between the presence of REAH-OC and the duration of NP disease (p = 0.0009), asthma (p = 0.004), and previous surgery (p = 0.0006). Before surgery, 90.6% of patients with REAH-OC were hypo-anosmic in contrast with one-half of patients having EP-OC (p = 0.0003). Predictors of poor olfactory outcomes after surgery were long-standing nasal symptoms (p = 0.027), history of previous surgery (p = 0.01), and history of previous middle turbinates resection (p = 0.0006). Polyp histology and surgery of the OC were not predictors of poor olfactory outcomes.

Conclusion

The resection of REAH or EP of the OC in patients with NP does not worsen but instead can improve the sense of smell after surgery.
Increased Expression of High-Mobility Group Protein B1 in Chronic Rhinosinusitis
Authors: Hong Sung-Moon , Cho Jung-Sun , Um Ji-Young , Shin Jae-Min , Park Il-Ho , Lee Seung Hoon , Lee Sang Hag , Lee Heung-Man
Published: July 2013

Background

Chronic rhinosinusitis (CRS) is an inflammation of the sinonasal mucosa and many inflammatory cells and cytokines are involved in its pathogenesis. High-mobility group protein B1 (HMGB1) is a DNA-binding protein that has a proinflammatory function when secreted into extracellular space. The purpose of this study was to evaluate the expression of HMGB1 in paranasal sinus mucosa and to determine the difference of HMGB1 expression between CRS patients and normal controls.

Methods

Paranasal sinus mucosa was obtained from 10 patients with CRS and 10 patients without CRS. Semiquantitative reverse transcriptase–polymerase chain reaction (RT-PCR), real-time PCR and Western blot analysis were performed to detect mRNA and protein. Sections of the mucosa were immunostained for localization of HMGB1 and image analysis was performed.

Results

RT-PCR and real-time PCR showed that the expression level of HMGB1 mRNA was significantly increased in the tissues of patients with CRS compared with controls. Western blot analysis showed that the expression level of HMGB1 protein was significantly increased in the tissues of CRS. In immunohistochemical staining, the HMGB1 protein was expressed in epithelial cells and inflammatory cells and the expression intensity of HMGB1 protein was stronger in CRS.

Conclusion

HMGB1 is increased in the paranasal sinus mucosa of patients with CRS. These results suggest a possible contribution of HMGB1 in the pathophysiology of CRS.
The Emerging Role of the Bitter Taste Receptor T2R38 in Upper Respiratory Infection and Chronic Rhinosinusitis
Authors: Lee Robert J. , Cohen Noam A.
Published: July 2013

Background

Maintaining a clean upper respiratory tract requires efficient detection of pathogenic bacteria so that the airway mucosa can mount proper defenses to neutralize and clear the offending microbes. Bitter taste receptors (T2Rs) may play a critical role in this process. T2Rs were originally identified in taste cells of the tongue, where they protect against the ingestion of toxic plant and/or bacterial products. However, T2Rs are also expressed in extragustatory tissue including the airways. One specific T2R isoform, T2R38, was recently shown to be expressed in cilia of sinonasal epithelial cells, suggesting that respiratory cilia may function as a chemosensory organelle, possibly to detect bacterial presence in the airway. T2R38 is encoded by the TAS2R38 gene, which has several common genetic polymorphisms that result in altered receptor functionality. Genetic variation in T2R38 may thus contribute to individual differences in susceptibility to upper airway infection. This study provides an overview of our current knowledge of T2R38 function in sinonasal defense and the implications for patients with chronic rhinosinusitis (CRS).

Methods

A literature review was performed of the current knowledge of the bitter taste receptor T2R38 in sinonasal physiology and CRS patient outcomes.

Results

Basic science research has indicated that the T2R38 receptor is activated by acyl-homoserine lactone (AHL) molecules secreted by gram-negative bacteria, including Pseudomonas aeruginosa. In sinonasal epithelial cells T2R38 stimulates an increase in nitric oxide production that increases mucociliary clearance and directly kills bacteria. Recent clinical studies have also found clinical correlations of TAS2R38 genotype with susceptibility to gram-negative upper respiratory infection as well as necessity for surgical intervention in CRS management.

Conclusion

T2R38 appears to be an important mediator of sinonasal epithelial defense, but further study is needed to more clearly determine how TAS2R38 genotype affects patient outcomes in CRS and other upper airway diseases.
Comparison of the Nasal Release of IL-4, IL-10, IL-17, CCL13/MCP-4, and CCL26/eotaxin-3 in Allergic Rhinitis during Season and after Allergen Challenge
Authors: Baumann Ralf , Rabaszowski Matthaeus , Stenin Igor , Tilgner Lisa , Scheckenbach Kathrin , Wiltfang Jens , Schipper Joerg , Chaker Adam , Wagenmann Martin
Published: July 2013

Background

Allergic rhinitis is an inflammatory disease characterized by local overproduction of type 2 cytokines and tissue eosinophilia. Recent research suggests the involvement of additional cytokines such as IL-17, chemokine (C-C motif) ligand (CCL) 26/eotaxin-3, and CCL13/monocyte chemoattractant protein-4 (MCP-4) in its pathophysiology. Furthermore, bronchial epithelial cells treated with IL-17 and type 2 cytokines distinctively up-regulated eotaxin-3 gene expression. In this study we investigated the kinetics of IL-4, IL-10, IL-17, eotaxin-3, and MCP-4 in seasonal allergic rhinitis volunteers after nasal allergen challenge (NAC) and their release during natural pollen exposure.

Methods

The nasal lavages of 15 symptomatic allergic and 14 nonallergic subjects were collected during the pollination season. Additionally, six allergic subjects underwent a single unilateral nasal allergen and control challenge out of season, and nasal secretions were collected. Levels of IL-4, IL-10, IL-17, eotaxin-3, and MCP-4 in nasal lavages and secretions were measured using an electrochemiluminescent assay.

Results

After NAC, allergic subjects had a significant immediate response of nasal symptoms as well as a significant increase at 5 hours of IL-4, IL-10, and IL-17 and at 2, 5, and 24 hours significantly raising levels of eotaxin-3. IL-17 and eotaxin-3 concentrations at 5 hours were correlated (r = 0.94; p = 0.005). During natural pollen exposure, barely detectable levels of IL-17 in allergic subjects were also correlated with eotaxin-3 (r = 0.62; p = 0.01). Eotaxin-3 and MCP-4 levels were significantly elevated 9- or 3.7-fold, respectively, and IL-10 and, unexpectedly, IL-4 were significantly lower in allergic subjects compared with nonallergic subjects.

Conclusion

Nasal IL-17, MCP-4, and, possibly, eotaxin-3 may aggravate and IL-10 may alleviate nasal mucosal allergy.