bluuebunny/crossref_metadata_2025 huggingface dataset:
Multicenter Crossover Study of Automated Control of Inspired Oxygen in Ventilated Preterm Infants
Authors: Claure Nelson , Bancalari Eduardo , D'Ugard Carmen , Nelin Leif , Stein Melanie , Ramanathan Rangasamy , Hernandez Richard , Donn Steven M. , Becker Michael , Bachman Thomas
Published: December 2010

OBJECTIVE:

To determine the efficacy and safety of automated adjustment of the fraction of inspired oxygen (Fio2) adjustment in maintaining arterial oxygen saturation (Spo2) within an intended range for mechanically ventilated preterm infants with frequent episodes of decreased Spo2.

METHODS:

Thirty-two infants (gestational age [median and interquartile range]: 25 weeks [24–27 weeks]; age: 27 days [17–36 days]) were studied during 2 consecutive 24-hour periods, one with Fio2 adjusted by clinical staff members (manual) and the other by an automated system (automated), in random sequence.

RESULTS:

Time with Spo2 within the intended range (87%–93%) increased significantly during the automated period, compared with the manual period (40% ± 14% vs 32% ± 13% [mean ± SD]). Times with Spo2 of >93% or >98% were significantly reduced during the automated period (21% ± 20% vs 37% ± 12% and 0.7% vs 5.6% [interquartile ranges: 0.1%–7.2% and 2.7%–11.2%], respectively). Time with Spo2 of <87% increased significantly during the automated period (32% ± 12% vs 23% ± 9%), with more-frequent episodes with Spo2 between 80% and 86%, whereas times with Spo2 of <80% or <75% did not differ between periods. Hourly median Fio2 values throughout the automated period were lower and there were substantially fewer manual Fio2 changes (10 ± 9 vs 112 ± 59 changes per 24 hours; P < .001), compared with the manual period.

CONCLUSIONS:

In infants with fluctuations in Spo2, automated Fio2 adjustment improved maintenance of the intended Spo2 range led to reduced time with high Spo2 and more-frequent episodes with Spo2 between 80% and 86%.
Differential Growth Patterns Among Healthy Infants Fed Protein Hydrolysate or Cow-Milk Formulas
Authors: Mennella Julie A. , Ventura Alison K. , Beauchamp Gary K.
Published: December 2010

OBJECTIVE:

Infant formulas differ considerably in composition and sensory profiles. In this randomized study, we examined whether healthy infants fed an extensively protein hydrolysate formula (PHF) would differ in feeding behavior and growth from those fed cow-milk formula (CMF).

PATIENTS AND METHODS:

Infants were randomly assigned to be fed CMF or PHF between 0.5 and 7.5 months of age. Each month for 7 months, infants were weighed and measured and then videotaped while being fed their assigned formula. Anthropometric z scores were calculated by using World Health Organization growth standards. Multilevel linear growth and piecewise mixed-effects models compared trajectories for growth measures and formula acceptance.

RESULTS:

When compared with infants fed CMF, infants fed PHF had significantly lower weight-for-length z scores across ages 2.5 to 7.5 months. There were no differences in length-for-age z scores, which indicate that group differences resulted from gains in weight, not length. Infants fed PHF also had significantly slower weight gain velocity compared with infants fed CMF. During the monthly assessments, PHF-fed infants consumed less formula to satiation than did CMF-fed infants across the study period. Maternal ratings of infants' acceptance of the formula did not differ at any age.

CONCLUSIONS:

z-score trajectories indicate that CMF-fed infants' weight gain was accelerated, whereas PHF-fed infants' weight gain was normative. Whether such differences in growth are because of differences in the protein content or amino acid profile of the formulas and, in turn, metabolism is unknown. Research on the long-term consequences of these early growth differences is needed.
The Tiniest Babies: A Registry of Survivors With Birth Weight Less Than 400 Grams
Authors: Bell Edward F. , Zumbach Diane K.
Published: December 2010

OBJECTIVE:

The purpose of this project was to collect information on surviving infants with birth weights of <400 g.

METHODS:

A Web-based registry was started in 2000 after searching for published reports of infants who survived to hospital discharge despite being born at <400 g. Fifteen cases were identified from scientific and lay print and Web-based publications. Parents, patients, and health providers were invited to submit data on additional infants. In the case of submissions from parents or patients, the information was confirmed by communication with a treating physician.

RESULTS:

As of September 1, 2010, the Tiniest Babies Registry had compiled data on 110 patients born between 1936 and 2010. The number of infants who survived each year increased since the early 1990s. The infants in the registry weighed between 260 and 397 g at birth and had gestational ages from 2167 to 34 weeks. Eighty-three (75%) of the patients are female. The 10 smallest infants are female, and the registry contains only 1 boy who was born weighing <300 g. The patients were born in 10 countries, including 80 (73%) born in the United States. The information on long-term functional outcome and health outcomes is limited. Many patients have ongoing health and learning concerns, and most of those for whom growth data are available remain short in stature and underweight for their age.

CONCLUSIONS:

Survival of infants born weighing <400 g is rare but increasing. The Tiniest Babies Registry provides a repository for information about this remarkable group of infants.
A Structured Career-Immersion Experience in the Third Year of Residency Training
Authors: Rosenberg Adam A. , Jones M. Douglas
Published: December 2010

This is the second in a series of 4 articles that highlight the projects that were chosen for implementation by the Initiative for Innovation in Pediatric Education (IIPE) review committee in response to the 2009 call for letters of intent. The authors describe their progress to date in implementing a training experience that allows residents the opportunity to engage in a longitudinal clinical experience that is aligned with their ultimate career choice. Mentors play a critical role in this immersion experience.

Carol Carraccio, MD, MA
Analysis of Resistance Asymmetry Due to p-n Junctions in Graphene FETs
Authors: Lee Kangmu , Wang Lingquan , Asbeck Peter , Moon Jeong
Published: December 2010

For graphene FETs, asymmetry in the drain current transfer characteristics has been observed. It has been proposed that asymmetry is due to additional resistances from p-n transition regions along the channel [1,2]. Calculations of the additional resistance have been received attention for small p-n transition lengths [3,4]. In this paper, we analyze the resistance of graphene FETs with p-n junctions when transition lengths are long compared with energy and momentum relaxation lengths, as is found in many experimental FETs. We employ a two dimensional device simulator to determine the electric field and channel conductivity variations in the vicinity of the FET gate, assuming rapid electron/hole equilibration. The simulations show added resistances in the range of 50-500 Ω μm p-n junction. We also extract the additional p-n resistance ΔR from experimental results by plots of Vd/Id vs. 1/|Vg-Vt|. Values of ΔR of order 450 Ω μm were extracted from FET results reported in [2]. Epitaxial graphene FETs fabricated on a SiC substrate [5] gives additional resistance of 620 Ωum. Both results are in reasonable agreement with the simulations.

The physically-based device simulator Atlas of Silvaco with parameters modified for graphene was used to obtain carrier distributions. A graphene FET on SiO2 substrate with a global back gate and 0.3μm gate/drain and gate/source gaps was studied. The carrier density in the gap region was controlled by back gate bias (Vbg) while the channel region under the top gate was modulated by top and back gate simultaneously. A long channel device at Vds=10mV was used to minimize the lateral electric field effect.

From the simulated carrier distribution, we can obtain the resistivity along the channel by ρ=1/[qμ(n+p)]. Mobility is assumed to be equal for electrons and holes, and depends on carrier concentration Ns, μ=μ0 (N0/Ns)1/2 where N0 and μ0 are intrinsic carrier concentration and peak mobility, respectively. Under positive Vbg, the graphene layer becomes n-type in the gap region and channel region. Proper top gate bias (Vg) may be applied to make channel region intrinsic, p-type or n-type. Therefore, various configurations along the channel such as npn or nnn structures may be created. In the p-n transition region, the total number of carriers reduces to N0 and resistivity shows a peak. The additional resistance of a p-n junction can be calculated by integrating the difference of the resistivity vs. channel position for the nnn and npn structures. The integrated resistance value is impacted by the peak height and peak width. The peak height is controlled by Vg-Vt; the resistivity reaches a maximum at the threshold condition, where the electron and hole densities reach their intrinsic levels. The peak width is also controlled by Vg, via fringing field of the gate.
Growth, Characterization and Comparisons of Few-layer Boron Nitride Nanosheets and Graphene
Authors: Zhang Hongxin , Sajjad Muhammad , Feng Peter
Published: December 2010

Few-layer hexagonal boron nitride (h-BN) nanosheets were produced by using super-short-pulse laser produced plasma deposition techniques. Scanning electron microscopy, Energy dispersive x-ray spectroscopy, and micro-Raman spectroscopy were used to explore the morphologies, elemental concentrations and bond structures of the few-layer h-BN nanosheets. High-quality transparent few-layer h-BN nanosheet with the width up to more than 6 μm, and length more than 20 μm were successfully obtained. The change in contrast suggests that the number of atomic layers varies over the area. A comparative study between the obtained few-layer h-BN nanosheets and the previously synthesized few-layer graphene were also conducted in order to further investigate the properties of the promising 2-Dimention (2D) nanomaterials. Our results suggest that the development h-BN nanosheets has the potential to revolutionize the understanding of 2-D nanomaterials with delocalized electronsheralding a transformative technology with dramatic future implications.
Stretchable Bioelectrodes
Authors: Wei Pinghung , Ziaie B.
Published: December 2010

In this paper, we present a stretchable electrode array for studying cell behavior subjected to mechanical strain. The electrode array consists of four gold nail-head pins (250μm tip diameter and 1.75mm spacing) or tungsten microwires (25.4μm in diameter) inserted into a polydimethylsiloxane (PDMS) platform (25.4×25.4mm2). Fusible indium alloy (liquid at room temperature) filled microchannels were used to connect the electrodes to the outside, thus providing the required stretchability. The electrodes were able to withstand strains of up to 40%. Repeated strain tests of several hundred cycles did not reveal any failure, illustrating the robustness of the platform. Mice cardiomyocytes and chick neurons were successfully cultured onto the platform.
Interlaced Circuits for Multidirectional Stretchable Electronics
Authors: Qiao Li , Xiaoming Tao , Tao Hua
Published: December 2010

Stretchable electronic circuits have the potential to the fields where electronics have to be conformable, deformable and stretchable into three dimensional surfaces. In this work, an “interlaced” structure is developed for multidirectional stretchable circuit. The shape of the conductor is loop-like configuration. A knitted structure is employed for the elastic substrate due to its flexibility, high stretchability, low cost and simple fabrication. The electro-mechanical behavior of the interlaced circuit is investigated in three different directions, i.e., 0-degree, 45-degree, and 90-degree, respectively. A significant improvement in stretchability is achieved in 0-degree direction. Then, a preliminary theoretical analysis is made in the electro-mechanical mechanism of the interlaced circuit. From the experimental investigation and theoretical analysis, it is found that the interlaced structure gives the conductor more freedom to move in the substrate, decreasing the stress concentration in the crest and trough parts of the loop when it is stretched.
The Influence of Maximum Bite Force on Patient Satisfaction and Quality of Life of Patients Wearing Mandibular Implant Overdentures
Authors: Geckili Onur , Bilhan Hakan , Mumcu Emre , Tuncer Necat
Published: December 2010

The treatment of edentulism with traditional complete dentures can often induce impaired masticatory function due to limited retention and stability, especially in the lower jaw. Mandibular interforaminal implants have been widely used to stabilize the dentures, consequently improving masticatory performance in edentulous individuals. The aim of the present study was to document the influence of this improved masticatory function on patient satisfaction and quality of life of patients wearing mandibular implant-supported overdentures. Sixty-two patients treated with various types of implant-supported mandibular overdentures between 2004 and 2007 were included in this retrospective study. Maximum bite force (MBF) was measured bilaterally using a device with 2 strain gauges connected to a strain gauge measurement system. All the included patients were asked to fill out visual analog scale (VAS) forms based on general and chewing satisfaction and OHIP-14 forms. Results were analyzed by the Spearman rho test. No statistically significant correlation was found between MBF values and VAS general or VAS chewing satisfaction or Oral Health Impact Profile scores (P > .05). The results indicate that MBF is not associated with the satisfaction or quality of life of implant-supported mandibular overdenture wearers.
The development of agriculture in the Americas: an ecological perspective
Authors: Doughty Christopher E.
Published: December 2010

Agriculture began independently in both North and South America ∼10,000 years before present (YBP), within a few thousand years of the arrival of humans in the Americas. This contrasts with the thousands of years that people were present in the old world before agriculture developed. In this paper, I hypothesize that the drastic extinctions of most large herbivores in the Americas may have accelerated the onset of agriculture in the Americas for three reasons: net primary production (NPP) became available for human utilization, the domestication of wild crop types was more feasible in the absence of megaherbivore competition, and hunting societies became more sedentary as their prey went extinct, the first step towards agriculture. I test these theories by calculating NPP liberated following the megafauna extinctions and find that the availability of NPP and the absence of competitive herbivory were significantly correlated with the timing of the onset of agriculture. The extinction of so many keystone herbivores may have accelerated the development of agriculture in the Americas, with humans essentially filling the empty herbivore niches.
Transformation of Diphenylarsinic Acid in Agricultural Soils
Authors: Maejima Yuji , Arao Tomohito , Baba Koji
Published: December 2010

We investigated the transformation and fate of diphenylarsinic acid (DPAA) during incubation in two types of soils (Entisol and Andisol) under aerobic and anaerobic conditions. Under anaerobic conditions only, DPAA was transformed into methyldiphenylarsine oxide by methylation. Under both aerobic and anaerobic conditions, DPAA was degraded to phenylarsonic acid by dephenylation, and phenylarsonic acid was subsequently methylated to form methylphenylarsinic acid and dimethylphenylarsine oxide. The degradation of DPAA in the Andisol was less extensive than in the Entisol. In autoclaved soil under anaerobic conditions, DPAA underwent little degradation during the 24‐wk incubation. In unautoclaved soils, the concentration of DPAA in soil clearly decreased after 24 wk of incubation, indicating that DPAA degradation was driven by microbial activity.
Spatial Contrasts of Seasonal and Intraflock Broiler Litter Trace Gas Emissions, Physical and Chemical Properties
Authors: Miles D. M. , Brooks J. P. , Sistani K.
Published: December 2010

Comprehensive mitigation strategies for gaseous emissions from broiler operations requires knowledge of the litters' physical and chemical properties, gas evolution, bird effects, as well as broiler house management and structure. This research estimated broiler litter surface fluxes for ammonia (NH3), nitrous oxide (N2O), and carbon dioxide (CO2). Ancillary measurements of litter temperature, litter total N, ammonium (NH4+), total C content, moisture, and pH were also made. Grid sampling was imposed over the floor area of two commercial broiler houses at the beginning (Day 1), middle (Day 23), and end (Day 43) of a winter and subsequent summer flock housed on reused pine shavings litter. The grid was composed of 36 points, three locations across the width, and 12 locations down the length of the houses. To observe feeder and waterer (F/W) influences on the parameters, eight additional sample locations were added in a crisscross pattern among these automated supply lines. Color variograms illustrate the nature of parameter changes within each flock and between seasons. Overall trends for the NH3, N2O, and CO2 gas fluxes indicate an increase in magnitude with bird age during a flock for both summer and winter, but flux estimates were reduced in areas where compacted litter (i.e., caked litter or cake) formed at the end of the flocks (at F/W locations and in the fan area). End of flock gas fluxes were estimated at 1040 mg NH3 m−2 h−1, 20 mg N2O m−2 h−1, and 24,200 mg CO2 m−2 h−1 in winter; and 843 mg NH3 m−2 h−1, 18 mg N2O m−2 h−1, and 27,200 mg CO2 m−2 h−1 in summer. The results of intensive sample efforts during winter and summer flocks, reported visually using contour plots, offer a resource to the poultry industry and researchers for creating new management strategies for improving production and controlling gas evolution. Particularly, efforts could focus on designing housing systems that minimize extremes in litter compaction. The extremes are undesirable with more friable litter prone to greater gas evolution and more compacted litter providing a slippery, disease‐sustaining surface.
Veterinary Antimicrobials in Feedlot Manure: Dissipation during Composting and Effects on Composting Processes
Authors: Cessna Allan J. , Larney Francis J. , Kuchta Sandra L. , Hao Xiying , Entz Toby , Topp Edward , McAllister Tim A.
Published: December 2010

Composting of manure may lead to the degradation of veterinary antimicrobials, but it is largely unknown if the presence of antimicrobials affects the composting process. Open‐air windrow composting of manure from beef cattle (Bos taurus) administered chlortetracycline, sulfamethazine, and tylosin was investigated in a 2‐yr study. At windrow construction, chlortetracycline had extensively isomerized to iso‐chlortetracycline. Sulfamethazine, tylosin, and iso‐chlortetracycline dissipated by first‐order kinetics, whereas the dissipation of enol/keto‐chlortetracycline was better described by exponential equations. At the end of the composting period, proportions of antimicrobials remaining were as follows: iso‐chlortetracycline (<1%), chlortetracycline (1 to 4.5%), tylosin (6.3%), and sulfamethazine (6.8% [2005], 41% [2006]). Times for 50% dissipation (DT50) decreased in the order: tylosin (20.3 to 43.5 d) > iso‐chlortetracycline (13.5 to 26.5 d) > enol/keto‐chlortetracycline (5.5 to 9.8 d). The DT50 values for sulfamethazine varied from 26.8 d in 2005 to 237 d in 2006. Treatments with chlortetracycline showed significantly reduced temperature rises (10.1 to 11.0°C) between Days 21 to 28 in 2006 compared with rises of 26.6 to 31.0°C for control and tylosin treatments, suggesting an inhibition of microbial activity. During composting in 2005, manure from cattle administered chlortetracycline at 44 mg kg−1 of feed lost significantly less dry matter, carbon, and nitrogen than manure from cattle fed 11 mg chlortetracycline kg−1 of feed, implying that the higher level of chlortetracycline inhibited microbial decomposition of organic matter. The study shows that while composting leads to dissipation of antimicrobials, the microbially driven composting process may be inhibited by their presence.
Real‐Time Quantification of mcrA, pmoA for Methanogen, Methanotroph Estimations during Composting
Authors: Sharma Ranjana , Ryan Kelly , Hao Xiying , Larney Francis J. , McAllister Tim A. , Topp Edward
Published: December 2010

Composting is the controlled biological decomposition of organic matter by microorganisms during predominantly aerobic conditions. It is being increasingly adopted due to its benefits in nutrient recycling, soil reclamation, and urban land use. However, it poses an environmental concern related to its contribution to greenhouse gas production. During composting, activities of methanogenic and methanotrophic communities influence the net methane (CH4) release into the atmosphere. Using quantitative polymerase chain reaction (qPCR), this study was aimed at assessing the changes in the methyl–coenzyme M reductase (mcrA) and particulate methane monooxygenase (pmoA) copy numbers for estimation of methanogenic and methanotrophic communities, respectively. Open‐windrow composting of beef cattle (Bos Taurus L.) manure with temperatures reaching >55°C was effective in degrading commensal Escherichia coli within the first week. Quantification of community DNA revealed significant differences in mcrA and pmoA copy numbers between top and middle sections. Consistent mcrA copy numbers (7.07 to 8.69 log copy number g−1) were detected throughout the 15‐wk composting period. However, pmoA copy number varied significantly over time, with higher values during Week 0 and 1 (6.31 and 5.41 log copy number g−1, respectively) and the lowest at Week 11 (1.6 log copy number g−1). Net surface CH4 emissions over the 15‐wk period were correlated with higher mcrA copy number. Higher net ratio of mcrA: pmoA copy numbers was observed when surface CH4 flux was high. Our results indicate that mcrA and pmoA copy numbers vary during composting and that methanogen and methanotroph populations need to be examined in conjunction with net CH4 emissions from open‐windrow composting of cattle feedlot manure.
Phosphorus Adsorption and Desorption Potential of Stream Sediments and Field Soils in Agricultural Watersheds
Authors: Agudelo Sandra C. , Nelson Nathan O. , Barnes Philip L. , Keane Timothy D. , Pierzynski Gary M.
Published: December 2010

Phosphorus release from stream sediments into water could increase P loads leaving agricultural watersheds and contribute to lag‐time between implementation of best management practices and improvement in water quality. Improved understanding of P release from stream sediments can assist in setting water quality goals and designing stream monitoring programs. The objective of this study was to estimate the relative potential of sediments and soils to release P to stream water in two agricultural watersheds. Stream sediments were collected from banks, pools, riffles, and depositional features. Soils were sampled from wheat, row crop, pasture, and manure‐amended fields. Sediments and soils were analyzed for equilibrium P concentration at zero net P sorption (EPC0), maximum P adsorption capacity (Pmax), anion exchange extractable P (Plab), and degree of P saturation. Dissolved reactive P (DRP) of stream water was monitored. Stream sediment EPC0 was similar to or less than EPC0 from field soils; however, Plab of stream sediments was three times less than field soils. Sediments were sandy and had low Pmax due to low oxalate‐extractable Fe and Al, which could be explained by stream geomorphology. Manure‐amended fields had the highest EPC0 and Plab due to continued inputs of manure‐based P; however, conventionally fertilized fields also represented an important P source due to their vast extent. Stream water DRP was similar to EPC0 of stream sediments during base flow and similar to EPC0 of field soils during storm flow. These results indicate that sediments in these streams are a relatively minor P source.
Novel Passive Co‐Treatment of Acid Mine Drainage and Municipal Wastewater
Authors: Strosnider William H. J. , Winfrey Brandon K. , Nairn Robert W.
Published: December 2010

A laboratory‐scale, four‐stage continuous‐flow reactor system was constructed to test the viability of high‐strength acid mine drainage (AMD) and municipal wastewater (MWW) passive co‐treatment. Synthetic AMD of pH 2.6 and acidity of 1870 mg L−1 as CaCO3 equivalent containing a mean 46, 0.25, 2.0, 290, 55, 1.2, and 390 mg L−1 of Al, As, Cd, Fe, Mn, Pb, and Zn, respectively, was added at a 1:2 ratio with raw MWW from the City of Norman, OK, to the system which had a total residence time of 6.6 d. During the 135‐d experiment, dissolved Al, As, Cd, Fe, Mn, Pb, and Zn concentrations were consistently decreased by 99.8, 87.8, 97.7, 99.8, 13.9, 87.9, and 73.4%, respectively, pH increased to 6.79, and net acidic influent was converted to net alkaline effluent. At a wasting rate of 0.69% of total influent flow, the system produced sludge with total Al, As, Cd, Cr, Cu, Fe, Pb, and Zn concentrations at least an order of magnitude greater than the influent mix, which presents a metal reclamation opportunity. Results indicate that AMD and MWW passive co‐treatment is a viable approach to use wastes as resources to improve water quality with minimal use of fossil fuels and refined materials.
Nutrient Bioassimilation Capacity of Aquacultured Oysters: Quantification of an Ecosystem Service
Authors: Higgins Colleen B. , Stephenson Kurt , Brown Bonnie L.
Published: December 2010

Like many coastal zones and estuaries, the Chesapeake Bay has been severely degraded by cultural eutrophication. Rising implementation costs and difficulty achieving nutrient reduction goals associated with point and nonpoint sources suggests that approaches supplemental to source reductions may prove useful in the future. Enhanced oyster aquaculture has been suggested as one potential policy initiative to help rid the Bay waters of excess nutrients via harvest of bioassimilated nutrients. To assess this potential, total nitrogen (TN), total phosphorous (TP), and total carbon (TC) content were measured in oyster tissue and shell at two floating‐raft cultivation sites in the Chesapeake Bay. Models were developed based on the common market measurement of total length (TL) for aquacultured oysters, which was strongly correlated to the TN (R2 = 0.76), TP (R2 = 0.78), and TC (R2 = 0.76) content per oyster tissue and shell. These models provide resource managers with a tool to quantify net nutrient removal. Based on model estimates, 106 harvest‐sized oysters (76 mm TL) remove 132 kg TN, 19 kg TP, and 3823 kg TC. In terms of nutrients removed per unit area, oyster harvest is an effective means of nutrient removal compared with other nonpoint source reduction strategies. At a density of 286 oysters m−2, assuming no mortality, harvest size nutrient removal rates can be as high as 378 kg TN ha−1, 54 kg TP ha−1, and 10,934 kg TC ha−1 for 76‐mm oysters. Removing 1 t N from the Bay would require harvesting 7.7 million 76‐mm TL cultivated oysters.
Effects of Winter Manure Application in Ohio on the Quality of Surface Runoff
Authors: Owens L. B. , Bonta J. V. , Shipitalo M. J. , Rogers S.
Published: December 2010

Winter application of manure poses environmental risks. Seven continuous corn, instrumented watersheds (approximately 1 ha each) at the USDA‐ARS North Appalachian Experimental Watershed research station near Coshocton, Ohio were used to evaluate the environmental impacts of winter manure application when using some of the Ohio Natural Resources Conservation Service recommendations. For 3 yr on frozen, sometimes snow‐covered, ground in January or February, two watersheds received turkey litter, two received liquid swine manure, and three were control plots that received N fertilizer at planting (not manure). Manure was applied at an N rate for corn; the target level was 180 kg N ha−1 with a 30‐m setback from the application area to the bottom of each watershed. Four grassed plots (61 × 12 m) were used for beef slurry application (9.1 Mg ha−1 wet weight); two plots had 61 × 12 m grassed filter areas below them, and two plots had 30 × 12 m filter areas. There were two control plots. Nutrient concentrations were sometimes high, especially in runoff soon after application. However, most events with high concentrations occurred with low flow volumes; therefore, transport was minimal. Applying manure at the N rate for crop needs resulted in excess application of P. Elevated P losses contributed to a greater potential of detrimental environmental impacts with P than with N. Filter strips reduced nutrient concentrations and transport, but the data were too limited to compare the effectiveness of the 30‐ and 61‐m filter strips. Winter application of manure is not ideal, but by following prescribed guidelines, detrimental environmental impacts can be reduced.
Carbon, Nitrogen, and Phosphorus Distribution in Particle Size–Fractionated Separated Pig and Cattle Slurry
Authors: Peters Karin , Hjorth Maibritt , Jensen Lars Stoumann , Magid Jakob
Published: December 2010

Solid liquid separation of animal slurry is a method to reduce the excess nutrient loads from intensive livestock production. Five different separation technologies (sedimentation, centrifugation, pressurized filtration, polymer flocculation and drainage, and iron chloride addition + polymer flocculation and drainage) were applied to pig and cattle slurry in a laboratory study. Separation efficiencies of mass, dry matter (DM), N, and P were measured. Particle size fractionation of the solid fractions was performed by subjecting them to wet fractionation and C, organic N (Norg), and P contents were subsequently measured. Chemical pretreatment with polymer before gravity drainage separated DM, total N, and P from raw pig and cattle slurry with the highest efficiencies. Sedimentation and centrifugation separated P from pig and cattle slurries with higher simple separation efficiencies (0.77 and 0.70, respectively) compared with pressurized filtration (0.15 and 0.37). Pressurized filtration transferred the lowest masses (14 and 18%) to the solid fractions. Solid fractions from pig slurry generally contained higher concentrations of P and C compared with cattle slurry solid fractions. The majority of C in solid fractions was present in particles >25 μm, whereas N and P were present in larger proportions in particles <25 μm. Chemical pretreatment increased the capture of smaller Norg‐ and P‐rich particles into larger particles between 25 and 1000 μm.
Improving Saline–Sodic Coalbed Natural Gas Water Quality Using Natural Zeolites
Authors: Ganjegunte Girisha K. , Vance George F. , Gregory Robert W. , Urynowicz Michael A. , Surdam Ronald C.
Published: December 2010

Management of saline–sodic water from the coalbed natural gas (CBNG) industry in the Powder River Basin (PRB) of Wyoming and Montana is a major environmental challenge. Clinoptilolite zeolites mined in Nevada, California, and New Mexico were evaluated for their potential to remove sodium (Na+) from CBNG waters. Based on the exchangeable cation composition, naturally occurring calcium (Ca2+)‐rich zeolites from New Mexico were selected for further evaluation. Batch adsorption experiments were conducted to evaluate the potential of the Ca2+‐rich natural clinoptilolites to remove Na+ from saline–sodic CBNG waters. Batch adsorption experiments indicated that Na+ adsorption capacity of clinoptilolite ranged from 4.3 (4 × 6 mesh) to 7.98 g kg−1 (14 × 40 mesh). Among the different adsorption isotherms investigated, the Freundlich Model fitted the data best for smaller‐sized (6 × 8, 6 × 14, and 14 × 40 mesh) zeolites. Passing the CBNG water through Ca2+‐rich zeolite columns reduced the salt content (electrical conductivity [EC]) by 72% with a concurrent reduction in sodium adsorption ratio (SAR) from 34 (typical level in northwestern PRB) to 10 mmol1/2 L−1/2 Zeolite technology appears to be an effective water treatment alternative to industrial membrane treatment for removing Na+ from poor‐quality CBNG waters.
Heavy Metals Distribution in an Iowa Suburban Landscape
Authors: Langner A. N. , Manu A. , Tabatabai M. A.
Published: December 2010

This study investigated the degree to which human activities through urbanization influence heavy metal concentrations in a suburban landscape in Ankeny, IA. Residential areas from different years in nine time periods of development were identified from aerial photos. Soil cores were collected from the center of the front yard of 10 randomly selected homes. Cores were subdivided into 0‐ to 5‐, 5‐ to 10‐, and 10‐ to 20‐cm increments from a composite of five cores. The soils were analyzed for organic C, pH, and total Cd, Co, Cr, Cu, Ni, Pb, and Zn. Results showed that organic C increased and pH decreased with time, and that there was a general decreasing trend in heavy metal concentrations from the pre‐1939 period until 1983–1990, after which there was a sharp increase in the concentrations of most of the metals. The mean Cu concentration ranged from 21 mg kg−1 for the pre‐1939 time period of development to 14.9 mg kg−1 for the recent period of development (2003–2005). Nickel concentrations increased significantly with depth with means of 21.3 mg kg−1 at depth 0 to 5 cm, 22.5 mg kg−1 at depth 5 to 10 cm, and 23.0 mg kg−1 at depth 10 to 20 cm. The concentrations of heavy metals were significantly intercorrelated, except Zn, suggesting their coexistence as mineral constituents or common contamination source. The concentrations of Cu and Pb in some locations could be due to anthropogenic inputs or higher organic matter content in soils adjacent to older homes. There appears to have been a source that caused an increase in Cd, Cr, Co, Cu, Pb, and Ni concentrations in soil adjacent to homes built between 1983 and 1990.
Methane Emissions from Grazing Cattle Using Point‐Source Dispersion
Authors: McGinn S. M. , Turner D. , Tomkins N. , Charmley E. , Bishop‐Hurley G. , Chen D.
Published: December 2010

The ability to accurately measure greenhouse gas (GHG) emissions is essential to gauge our ability to reduce these emissions. Enteric methane from ruminants is an important but often difficult source to quantify since it depends on the amount and type of feed intake. Unfortunately, many of the available measurement techniques for estimating enteric methane emissions can impose a change in feed intake. Our study evaluates a nonintrusive technique that uses a novel approach (point‐source dispersion with multiple open‐path concentrations) to calculate enteric methane emissions from grazing cattle, reported as the major source of GHG in many countries, particularly Australia. A scanner with a mounted open‐path laser was used to measure methane concentration across five paths above a paddock containing 18 grazing cattle over 16 d. These data were used along with wind statistics in a dispersion model (WindTrax) to estimate an average herd methane emission rate over 10‐min intervals. Enteric methane emissions from the herd grazing a combination of Rhodes grass (Chloris gayana Kunth) and Leucaena [Leucaena leucocephala (Lam.)] averaged (± SD) 141 (± 147) g animal−1 d−1 In a release‐recovery experiment, the technique accounted for 77% of the released methane at a single point. Our study shows the technique generates more reliable methane emissions during daytime (unstable stratification).
Drinking Water Treatment Residuals: A Review of Recent Uses
Authors: Ippolito J. A. , Barbarick K. A. , Elliott H. A.
Published: December 2010

Coagulants such as alum [Al2(SO4)3•14H2O], FeCl3, or Fe2(SO4)3 are commonly used to remove particulate and dissolved constituents from water supplies in the production of drinking water. The resulting waste product, called water‐treatment residuals (WTR), contains precipitated Al and Fe oxyhydroxides, resulting in a strong affinity for anionic species. Recent research has focused on using WTR as cost‐effective materials to reduce soluble phosphorus (P) in soils, runoff, and land‐applied organic wastes (manures and biosolids). Studies show P adsorption by WTR to be fast and nearly irreversible, suggesting long‐term stable immobilization of WTR‐bound P. Because excessive WTR application can induce P deficiency in crops, effective application rates and methods remain an area of intense research. Removal of other potential environmental contaminants [ClO4−, Se(+IV and +VI), As(+III and +V), and Hg] by WTR has been documented, suggesting potential use of WTR in environmental remediation. Although the creation of Al plant toxicity and enhanced Al leaching are concerns expressed by researchers, these effects are minimal at circumneutral soil pH conditions. Radioactivity, trace element levels, and enhanced Mn leaching have also been cited as potential problems in WTR usage as a soil supplement. However, these issues can be managed so as not to limit the beneficial use of WTR in controlling off‐site P losses to sensitive water bodies or reducing soil‐extractable P concentrations.
Peroxidase‐Catalyzed Stabilization of 2,4‐Dichlorophenol in Alkali‐extracted Soils
Authors: Palomo Mónica , Bhandari Alok
Published: December 2010

Horseradish peroxidase‐ (HRP) mediated stabilization of phenolic contaminants is a topic of interest due to its potential for remediation of contaminated soils. This study evaluated the sorption of 2,4‐dichlorophenol (DCP) and its HRP‐mediated stabilization in two alkali‐extracted soils. Alkali extraction reduced the soil organic matter (SOM) contents of the geomaterials and enriched the residual SOM with humin C. Sorption of DCP on these sorbents was complete within 1 d. However, most of the sorbed DCP was removed from the geomaterials by water and methanol, suggesting weak solute‐sorbent interactions. The addition of HRP resulted in the generation of DCP polymerization products (DPP), which partitioned between the aqueous and solid phases. The DPP phase distribution was rapid and complete within 24 h. Between 70 and 90% of the added DCP was converted to DPP and up to 43% of the initial aqueous phase contaminant was transformed into a residue that was resistant to extraction with methanol. Bound residues of DPP increased with initial aqueous phase solute concentration and remained fairly constant after 7 d of contact. Contaminant stabilization was noted to be high in the humin‐mineral geomaterial. Results illustrate that HRP may be effective in stabilizing phenolic contaminants in subsoils that are likely to contain SOM enriched in humin C.
Predicting Methyl Iodide Emission, Soil Concentration, and Pest Control in a Two–Dimensional Chamber System
Authors: Luo Lifang , Yates Scott R. , Ashworth Daniel J.
Published: December 2010

Due to ever–increasing state and federal regulations, the future use of fumigants is predicted on reducing negative environmental impacts while offering sufficient pest control efficacy. To foster the development of a best management practice, an integrated tool is needed to simultaneously predict fumigant movement and pest control without having to conduct elaborate and costly experiments. The objective of this study was (i) to present a two–dimensional (2–D) mathematical model to describe both fumigant movement and pest control and (ii) to evaluate the model by comparing the simulated and observed results. Both analytical and numerical methods were used to predict methyl iodide (MeI) transport and fate. To predict pest control efficacy, the concentration–time index (CT) was defined and a two–parameter logistic survival model was used. Dose–response curves were experimentally determined for MeI against three types of pests (barnyardgrass [Echinochloa crus–galli] seed, citrus nematode [Tylenchulus semipenetrans], and fungi [Fusarium oxysporum]). Methyl iodide transport and pest control measurements collected from a 2–D experimental system (60 by 60 cm) were used to test the model. Methyl iodide volatilization rates and soil gas–phase concentrations over time were accurately simulated by the model. The mass balance analysis indicates that the fraction of MeI degrading in the soil was underestimated when determined by the appearance of iodide concentration. The experimental results showed that after 24 h of MeI fumigation in the 2–D soil chamber, fungal population was not suppressed; >90% of citrus nematodes were killed; and barnyardgrass seeds within 20–cm distance from the center were affected. These experimental results were consistent with the predicted results. The model accurately estimated the MeI movement and control of various pests and is a powerful tool to evaluate pesticides in terms of their negative environmental impacts and pest control under various environmental conditions and application methods.
Effect of Uranium(VI) Speciation on Simultaneous Microbial Reduction of Uranium(VI) and Iron(III)
Authors: Stewart Brandy D. , Amos Richard T. , Fendorf Scott
Published: December 2010

Uranium is a pollutant of concern to both human and ecosystem health. Uranium's redox state often dictates whether it will reside in the aqueous or solid phase and thus plays an integral role in the mobility of uranium within the environment. In anaerobic environments, the more oxidized and mobile form of uranium (UO22+ and associated species) may be reduced, directly or indirectly, by microorganisms to U(IV) with subsequent precipitation of UO2 However, various factors within soils and sediments, such as U(VI) speciation and the presence of competitive electron acceptors, may limit biological reduction of U(VI). Here we examine simultaneous dissimilatory reduction of Fe(III) and U(VI) in batch systems containing dissolved uranyl acetate and ferrihydrite‐coated sand. Varying amounts of calcium were added to induce changes in aqueous U(VI) speciation. The amount of uranium removed from solution during 100 h of incubation with S. putrefaciens was 77% in absence of Ca or ferrihydrite, but only 24% (with ferrihydrite) and 14% (without ferrihydrite) were removed for systems with 0.8 mM Ca. Dissimilatory reduction of Fe(III) and U(VI) proceed through different enzyme pathways within one type of organism. We quantified the rate coefficients for simultaneous dissimilatory reduction of Fe(III) and U(VI) in systems varying in Ca concentration (0–0.8 mM). The mathematical construct, implemented with the reactive transport code MIN3P, reveals predominant factors controlling rates and extent of uranium reduction in complex geochemical systems.
Microbiological Quality of Roof‐Harvested Rainwater and Health Risks: A Review
Authors: Ahmed W. , Gardner T. , Toze S.
Published: December 2010

Roof‐harvested rainwater (RHRW) has been considered an effective alternative water source for drinking and various nonpotable uses in a number of countries throughout the world. The most significant issue in relation to using untreated RHRW for drinking or other potable uses, however, is the potential public health risks associated with microbial pathogens. This paper reviews the available research reporting on the microbial quality of RHRW and provides insight on the capacity of fecal indicator bacteria to monitor health risks and disease outbreaks associated with the consumption of untreated RHRW. Several zoonotic bacterial and protozoan pathogens were detected in individual and communal rainwater systems. The majority of the studies reported in the literature assessed the quality of rainwater on the basis of the presence or absence of specific pathogens, with little information available regarding the actual numbers of such pathogens. In addition, no information is available concerning the ongoing prevalence of different pathogens in RHRW over time. The published data suggest that the microbial quality of RHRW should be considered less than that expected for potable water and that the commonly used indicators may not be suitable to indicate the presence of pathogens in RHRW. Several case control studies established potential links between gastroenteritis and consumption of untreated RHRW. Therefore, health risks assessment models, such as those using Quantitative Microbial Risk Assessment, should be used to manage and mitigate health risks associated with drinking and nonpotable uses of RHRW.
Impacts of Pollution Controls on Air Quality in Beijing during the 2008 Olympic Games
Authors: Shen Jianlin , Tang Aohan , Liu Xuejun , Kopsch Jenny , Fangmeier Andreas , Goulding Keith , Zhang Fusuo
Published: December 2010

Air pollution has become one of the main environmental concerns in China since the 1980s due to China's rapid economic growth and resultant pollution. However, it is difficult to directly evaluate the anthropogenic contribution to air pollution in China. The 2008 Olympic Games in Beijing provided a unique opportunity for testing the contribution of anthropogenic pollution because of the clean‐up controls on air quality in Beijing enforced over the period of the Games. In this case study, we monitored the concentrations of major air pollutants before, during, and after the Olympics at a suburban site in Beijing. Atmospheric concentrations of PM10, PM2.5, NH3, NO2, SO2, and the particulate ions NH4+, NO3−, SO42−, Ca2+, Mg2+, and K+ all decreased during the Olympic period because of strict emission controls, compared with the same period from 2005 to 2007. For example, the average PM10 concentration (61 μg m−3) during the Olympics was only 37% of that (166 μg m−3) in the same month (August) from 2005 to 2007. However, just 1 mo and 1 yr after the Games had ended, mean concentrations of these pollutants had increased significantly again. This rapid “recovery” of air pollutant concentrations after the Olympics suggests that China needs to implement long‐lasting decreases in its air pollution in Beijing and other major cities.
Mechanism of the Hepatoprotective Activities of the Garcinia Hydroxybiflavanonol, GB1
Authors: Madubunyi Ifeanyi I
Published: December 2010

Garcinia kola Heckel (Guttiferae) known as Aki-ilu (meaning bitter kola) is a large economic tree indigenous to southern part of Nigeria. Its seeds have been of interest to researchers because of its use in the treatment of various disease conditions in Nigerian traditional medicine. The influence of the Garcinia hydroxybiflavanonol, GB1 on the membrane of primary cultured rat hepatocytes was studied. This work provides the first concrete evidence on the membrane stabilizing action of the hepatoprotective principle of Garcinia kola nuts. Results demonstrated that at high concentrations, the Garcinia hydroxybiflavanonol, GB1 as well as silibinin interact very strongly with the protein components of the liver cell membrane thereby causing an unspecific inhibition of the different transport systems in the membrane. These findings demonstrate that the hepatoprotective activity of the Garcinia hydroxybiflavanonols could be explained, at least in part, by their ability to stabilize the membrane of hepatocytes. This stabilizing effect may find a beneficial application in the therapy of various hepatic disorders especially those involving abnormal fragility of the hepatocyte membrane.
Two methods for measuring laser beam diameter
Authors: Marshall Wesley J.
Published: December 2010

Two methods for measuring beam diameter are described with the derivation of the equations that make them valid. These methods are the aperture method and the knife edge technique. These methods have been used for decades; however, many do not have a firm grasp of the basic equations that make the methods valid and therefore cannot use and modify the methods with confidence to produce the desired results. The text derives the equations from basic science and mathematics to clarify the underlying concepts of the methods.