bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidemiology of Apnea and Bradycardia Resolution in Premature Infants
Authors: Lorch Scott A. , Srinivasan Lakshmi , Escobar Gabriel J.
Published: July 2011

BACKGROUND:

There is little epidemiologic evidence to assess the maturation of respiratory control in premature infants.

OBJECTIVE:

To measure the success rate or the percentage of infants who have no additional events of various apnea- or bradycardia-free intervals after correcting for gestational age, postmenstrual age of the last apnea or bradycardia event, and the severity of the event.

METHODS:

This was a retrospective cohort study of infants born at 34 weeks' gestational age or earlier at 1 of 5 Kaiser Permanente Medical Care Program hospitals between 1998 and 2001. The success rates of various apnea- or bradycardia-free intervals were calculated after stratifying according to gestational age, postmenstrual age of the last event, or event severity.

RESULTS:

Among the 1403 infants identified in this study, 84.2% did not have an apnea event and 78.5% did not have a bradycardia event after they were otherwise ready for discharge. For the entire cohort, a 95% success rate was statistically reached, with a 7-day apnea- or bradycardia-free interval. Infants with a gestational age of 30 weeks or less had a 5% to 15% lower success rate than infants with a gestational age more than 30 weeks for any given apnea- or bradycardia-free interval. The success rate was reduced by an additional 5% to 10% if the last apnea or bradycardia event occurred at a postmenstrual age of more than 36 weeks. Including only the most severe events slightly improved the success rate of a given interval.

CONCLUSIONS:

The risk of recurrence for apnea or bradycardia differs depending on the gestational age of the infant and the postmenstrual age of the last apnea or bradycardia event.
Room-Air Versus Oxygen Administration for Resuscitation of Preterm Infants: The ROAR Study
Authors: Rabi Yacov , Singhal Nalini , Nettel-Aguirre Alberto
Published: July 2011

OBJECTIVE:

We conducted a blinded, prospective, randomized control trial to determine which oxygen-titration strategy was most effective at achieving and maintaining oxygen saturations of 85% to 92% during delivery-room resuscitation.

METHODS:

Infants born at 32 weeks' gestation or less were resuscitated either with a static concentration of 100% oxygen (high-oxygen group) or using an oxygen-titration strategy starting from a concentration of 100% (moderate-oxygen group), or 21% oxygen (low-oxygen group). In the moderate- and low-oxygen groups, the oxygen concentration was adjusted by 20% every 15 seconds to reach a target oxygen saturation range of 85% to 92%. Treatment failure was defined as a heart rate slower than 100 beats per minute for longer than 30 seconds.

RESULTS:

The moderate-oxygen group spent a greater proportion of time in the target oxygen saturation range (mean: 0.21 [95% confidence interval: 0.16–0.26]) than the high-oxygen group (mean: 0.11 [95% confidence interval: 0.09–0.14]). Infants in the low-oxygen group were 8 times more likely to meet the criteria for treatment failure than those in the high-oxygen group (24% vs 3%; P = .022). The 3 groups did not differ significantly in the time to reach the target oxygen saturation range.

CONCLUSIONS:

Titrating from an initial oxygen concentration of 100% was more effective than giving a static concentration of 100% oxygen in maintaining preterm infants in a target oxygen saturation range. Initiating resuscitation with 21% oxygen resulted in a high treatment-failure rate.
Sensitivity to Secondhand Smoke Exposure Predicts Future Smoking Susceptibility
Authors: Lessov-Schlaggar Christina N. , Wahlgren Dennis R. , Liles Sandy , Ji Ming , Hughes Suzanne C. , Winickoff Jonathan P. , Jones Jennifer A. , Swan Gary E. , Hovell Melbourne F.
Published: July 2011

OBJECTIVE:

Susceptibility to cigarette smoking in tobacco-naive youth is a strong predictor of smoking initiation. Identifying mechanisms that contribute to smoking susceptibility provide information about early targets for smoking prevention. This study investigated whether sensitivity to secondhand smoke exposure (SHSe) contributes to smoking susceptibility.

PARTICIPANTS AND METHODS:

Subjects were high-risk, ethnically diverse 8- to 13-year-old subjects who never smoked and who lived with at least 1 smoker and who participated in a longitudinal SHSe reduction intervention trial. Reactions (eg, feeling dizzy) to SHSe were assessed at baseline, and smoking susceptibility was assessed at baseline and 3 follow-up measurements over 12 months. We examined the SHSe reaction factor structure, association with demographic characteristics, and prediction of longitudinal smoking susceptibility status.

RESULTS:

Factor analysis identified “physically unpleasant” and “pleasant” reaction factors. Reported SHSe reactions did not differ across gender or family smoking history. More black preteens reported feeling relaxed and calm, and fewer reported feeling a head rush or buzz compared with non-Hispanic white and Hispanic white counterparts. Longitudinally, 8.5% of subjects tracked along the trajectory for high (versus low) smoking susceptibility. Reporting SHSe as “unpleasant or gross” predicted a 78% reduction in the probability of being assigned to the high–smoking susceptibility trajectory (odds ratio: 0.22 [95% confidence interval: 0.05–0.95]), after covariate adjustment.

CONCLUSIONS:

Assessment of SHSe sensitivity is a novel approach to the study of cigarette initiation etiology and informs prevention interventions.
Mercury Content of Blood Transfusions for Infants With Extremely Low Birth Weight
Authors: Elabiad Mohamad T. , Hook Rebecca E.
Published: July 2011

OBJECTIVES:

To assess whether blood transfusions for infants with birth weights of 1000 g or less are a source of mercury and whether any mercury delivered through the transfusion is above the currently set oral reference dose.

PATIENTS AND METHODS:

We studied an observational cohort. Inclusion criteria included birth weight 1000 g or less and receipt of 1 or more packed red blood cell transfusions. Packed red blood cell units were tested prospectively for mercury levels. The quantity of transfused mercury was calculated on the basis of transfused volume and packed red blood cell mercury level. The resulting mercury level was compared with the reference dose as set by the Agency for Toxic Substances and Disease Registry, the World Health Organization, and the US Environmental Protection Agency.

RESULTS:

Thirty-seven infants (birth weight: 736 ± 157 g; gestational age: 25.5 ± 1.5 weeks) met the inclusion criteria. A total of 325 transfusions from 49 packed red blood cell units were administered. Mercury was detected in 40 units. The average mercury level in a packed red blood cell unit was 1.9 ± 2.6 μg/L (median: 0.9 μg/L [interquartile range: 0.3–2.5]). None of the infants received any mercury above the reference dose set by the Agency for Toxic Substances and Disease Registry and the World Health Organization. Twelve infants received 1 transfusion, and 5 infants received 2 transfusions above the Environmental Protection Agency reference dose during their entire hospitalization.

CONCLUSIONS:

Packed red blood cells are a source of mercury for infants. However, the amount delivered is low compared with currently set safety levels. The episodes in which mercury intake exceeded the reference dose were rare. However, without long-term follow-up, no conclusions can be made about the cognitive implications of these episodes.
Sagittal Sinus Compression Is Associated With Neonatal Cerebral Sinovenous Thrombosis
Authors: Tan Marilyn , deVeber Gabrielle , Shroff Manohar , Moharir Mahendra , Pontigon Anne-Marie , Widjaja Elisa , Kirton Adam
Published: July 2011

OBJECTIVE :

Neonatal cerebral sinovenous thrombosis (CSVT) causes lifelong morbidity. Newborns frequently incur positional occipital bone compression of the superior sagittal sinus (SSS). We hypothesized that SSS compression is associated with neonatal CSVT.

METHODS:

Our retrospective case-control study recruited neonates with CSVT (SickKids Children's Stroke Program, January 1992–December 2006). Controls were neonates without CSVT undergoing magnetic resonance or computed tomography venography (institutional imaging database, 2002–2005) who were matched 2 per each case patient. Blinded neuroimaging review by 2 experts quantified SSS compression and head position. Effect of SSS compression on the primary outcome of CSVT was determined (logistic regression). Secondary analyses included the relationship of head position to SSS compression (t test) and group comparisons (cases versus controls, cases with and without compression) for demographic, clinical, and CSVT factors (χ2 and Wilcoxon Mann-Whitney tests).

RESULTS:

Case (n = 55) and control (n = 90) patients had similar ages and delivery modes. SSS compression was common (cases: 43%; controls: 41%). Controlling for gender and head position, SSS compression was associated with CSVT (odds ratio: 2.5 [95% confidence interval: 1.07–5.67]). Compression was associated with greater mean (SD) angle toward head flexion (101.2 [15.0] vs 111.5 [9.7]; P < .001). Among CSVT cases, neonates with and without compression had comparable gestational age, delivery mode, risk factors, anticoagulation treatment, thrombus location, propagation, infarction, recanalization, and outcome. Many idiopathic cases had SSS compression (79%). Interrater reliability of compression measurements was high (κ = 0.87).

CONCLUSIONS:

Neonatal SSS compression is common, quantifiable, and associated with CSVT. Optimizing head position and/or developing devices to alleviate mechanical SSS compression may represent a novel means to improve outcomes.
Secondhand Smoke Exposure and Neurobehavioral Disorders Among Children in the United States
Authors: Kabir Zubair , Connolly Gregory N. , Alpert Hillel R.
Published: July 2011

OBJECTIVES:

The association between parent-reported postnatal secondhand tobacco smoke exposure in the home and neurobehavioral disorders (attention-deficit/hyperactivity disorder, learning disabilities, and conduct disorders) among children younger than 12 years in the United States was examined using the 2007 National Survey on Children's Health. Excess neurobehavioral disorders attributable to secondhand smoke (SHS) exposure in the home in 2007 were further investigated.

METHODS:

The methods used in this study were multivariable logistic regression models that accounted for potential confounders and complex survey designs to evaluate associations.

RESULTS:

A total of 6% of 55 358 children (aged < 12 years), corresponding to a weighted total of 4.8 million children across the United States, were exposed to SHS in the home. The weighted prevalence and 95% confidence intervals of each of the children's neurobehavioral outcomes were 8.2% (7.5–8.8) with learning disabilities, 5.9% (5.5–6.4) with attention-deficit/hyperactivity disorder, and 3.6% (3.1–4.0) with behavioral and conduct disorders. Children exposed to SHS at home had a 50% increased odds of having ≥2 childhood neurobehavioral disorders compared with children who were not exposed to SHS. Boys had a significantly higher risk. Older children, especially those aged 9 to 11 years, and those living in households with the highest poverty levels were at greater risk. In absolute terms, 274 100 excess cases in total of these 3 disorders could have been prevented if children had not been exposed to SHS in their homes.

CONCLUSIONS:

The findings of the study, which are associational and not necessarily causal, underscore the health burden of childhood neurobehavioral disorders that may be attributable to SHS exposure in homes in the United States.
Management of Pediatric Chest Pain Using a Standardized Assessment and Management Plan
Authors: Friedman Kevin G. , Kane David A. , Rathod Rahul H. , Renaud Ashley , Farias Michael , Geggel Robert , Fulton David R. , Lock James E. , Saleeb Susan F.
Published: July 2011

OBJECTIVES:

Chest pain is a common reason for referral to pediatric cardiologists and often leads to an extensive cardiac evaluation. The objective of this study is to describe current management practices in the assessment of pediatric chest pain and to determine whether a standardized care approach could reduce unnecessary testing.

PATIENTS AND METHODS:

We reviewed all patients, aged 7 to 21 years, presenting to our outpatient pediatric cardiology division in 2009 for evaluation of chest pain. Demographics, clinical characteristics, patient outcomes, and resource use were analyzed.

RESULTS:

Testing included electrocardiography (ECG) in all 406 patients, echocardiography in 175 (43%), exercise stress testing in 114 (28%), event monitoring in 40 (10%), and Holter monitoring in 30 (7%). A total of 44 (11%) patients had a clinically significant medical or family history, an abnormal cardiac examination, and/or an abnormal ECG. Exertional chest pain was present in 150 (37%) patients. In the entire cohort, a cardiac etiology for chest pain was found in only 5 of 406 (1.2%) patients. Two patients had pericarditits, and 3 had arrhythmias. We developed an algorithm using pertinent history, physical examination, and ECG findings to suggest when additional testing is indicated. Applying the algorithm to this cohort could lead to an ∼20% reduction in echocardiogram and outpatient rhythm monitor use and elimination of exercise stress testing while still capturing all cardiac diagnoses.

CONCLUSIONS:

Evaluation of pediatric chest pain is often extensive and rarely yields a cardiac etiology. Practice variation and unnecessary resource use remain concerns. Targeted testing can reduce resource use and lead to more cost-effective care.
Ecohydrology for implementation of the EU water framework directive
Authors: Zalewski Maciej
Published: July 2011

Ecohydrology is defined as a sub-discipline of hydrology that focuses on ecological processes occurring within the hydrological cycle and strives to utilise such processes to enhance environmental sustainability. The first step in defining the role of ecohydrology for implementation of the EU water framework directive should be the analysis of the pattern of scientific methodologies that stimulate recent progress in environmental sciences. Such progress has been directly translated into ‘good ecological status' of inland and coastal waters. From the perspective of the evolution of paradigms in environmental sciences during recent decades, three stages can be distinguished. The first two are information (structure states, relationships) and knowledge (through integration of different scientific disciplines, synergies in information can highlight the patterns and processes (e.g. ecohydrology)). The third and most advanced stage of the science is wisdom – the ability to use information and knowledge to develop innovative solutions of environmental problems with consideration of priorities to society. The conceptual framework for transition from the first to the second and third stages is provided by three principles of ecohydrology: hydrological (information on the abiotic structure of a river basin; dynamics of hydrological processes and spatial temporal specifics of anthropogenic impacts); ecological (the potential for basin resilience enhancement); ecotechnological (the use of information and knowledge for the development of new ecological biotechnologies and system solutions). The implicit conclusion is that in order to accelerate cost-efficient implementation of the EU water framework directive, more effort has to be put into the transition from research to interdisciplinary efforts to deepen our knowledge of processes and regulatory mechanisms within ecosystems. Further progress from knowledge to wisdom has to be made by broader involvement of environmental scientists who use foresight methodology for harmonisation technologies, environmental potential and cultural heritage in large-scale projects of environment restoration and sustainable development of infrastructure.
Histologic Comparison of Healing After Tooth Extraction With Ridge Preservation Using Mineralized Versus Demineralized Freeze‐Dried Bone Allograft
Authors: Wood Robert A. , Mealey Brian L.
Published: July 2011

Background: Allografts, such as demineralized freeze‐dried bone allograft (DFDBA) and mineralized freeze‐dried bone allograft (FDBA) are commonly used by clinicians for ridge preservation procedures. The primary objective of this study is to histologically evaluate and compare the healing of non‐molar extraction sockets grafted with DFDBA versus FDBA for ridge preservation. The secondary aim of this study is to compare dimensional changes in ridge height and width after grafting with these two materials.

Materials: Forty patients were randomly divided into two groups of 20. Extraction sockets were filled with either FDBA or DFDBA. To minimize variables associated with the organ donor and with tissue processing, all of the graft material was procured from a single donor; the only difference in the two materials was the percentage mineralization of the final bone graft. A 2‐mm‐diameter core biopsy was taken from each grafted site ≈19 weeks after grafting. Histomorphometric analysis was performed to determine percentage of vital bone, residual graft particles, and connective tissue (CT)/other non‐bone components.

Results: There were no significant differences when comparing changes in alveolar ridge dimensions of the two groups. There was no significant difference in percentage CT/other between groups. DFDBA had a significantly greater percentage of vital bone at 38.42% versus FDBA at 24.63%. The DFDBA group also had a significantly lower mean percentage of residual graft particles at 8.88% compared to FDBA at 25.42%.

Conclusion: This study provides the first histologic and clinical evidence directly comparing ridge preservation with DFDBA versus FDBA in humans and demonstrates significantly greater new bone formation with DFDBA.
Permanent Beds vs. Conventional Tillage in Irrigated Arid Central Asia
Authors: Ibragimov Nazar , Evett Steven , Esenbekov Yusupbek , Khasanova Feryuza , Karabaev Ikramjan , Mirzaev Lutfullo , Lamers John
Published: July 2011

Limited or no tillage with residue retention on the soil surface has had mixed success in irrigated agricultural systems. The effects of tillage and crop residue management on soil properties and crop yields were studied on a silt loam soil using a rotation of winter wheat (Triticum aestivum L.) and maize (Zea mays L.) for 2 yr, followed by cotton (Gossypium hirsutum L.) for 2 yr. Permanent beds (PB) with limited reshaping and conventional tillage (CT) were compared, each with both 25% residue retention on a mass basis (R25) and 100% residue retention (R100). There was greater soil compaction and consolidation in the 0.2‐ to 0.3‐m depth with the PB system regardless of residue retention practice. Compared with the CT system and the PB+R25 treatment combination, the PB+R100 treatment combination increased the amount of water‐stable macroaggregates, however only in the fourth year. The soil organic C in the 0‐ to 0.4‐m depth increased at 0.70 Mg ha−1 yr−1 in PB+R100 vs. 0.48 Mg ha−1 yr−1 in CT+R100. Poor early plant growth and reduced plant population in PB caused decreased water use efficiency (WUE) and irrigation water use efficiency (IWUE) of maize and cotton grown consecutively in 2006 and 2007. Generally, R100 improved IWUE and WUE, except for cotton in 2007. For PB+R100, cotton seed‐lint IWUE in 2008 increased to 0.59 kg m−3 from 0.41 earlier. Smaller maize and cotton plant populations and cooler soil temperatures at cotton emergence in PB+R100 decreased crop productivity during the first 3 yr.
Modeling Apparent Nitrogen Mineralization under Field Conditions Using Regressions and Artificial Neural Networks
Authors: Alvarez Roberto , Steinbach Haydée S.
Published: July 2011

Soil N mineralization is an important source of N for grain crops, but its estimation under field conditions is usually very difficult. Our objective was to develop models suitable for predicting N mineralization during the growing seasons of wheat (Triticum aestivum L.) and corn (Zea mays L.) under field conditions. Fifty‐eight field experiments were performed with wheat, and 35 with corn, along three growing seasons, in which soil apparent N mineralization was estimated by the mass balance approach. Apparent nitrogen mineralized from decomposing residues (ANMR) or soil humic substances (ANMH) were estimated separately. Two empirical modeling techniques were tested, linear regression and artificial neural networks, using as independent variables or inputs some environmental variables. Both techniques allowed the development of suitable models for N mineralization prediction (R2 > 0.68), but neural networks gave slightly better results. The ANMR ranged from −42 to 64 kg N ha−1, increasing as residue mass and N concentration increased. An average ANMR of 15 to 16 kg N ha−1 was produced both during wheat and corn growing seasons. The ANMH ranged from −80 to 328 kg N ha−1, being on average four times greater during corn growing cycle than during wheat season (127 vs. 34 kg N ha−1). The ANMH decreased as initial mineral N content of the soil, remaining residue mass or fine particles content of the soil increased, and it was greater in soils of higher organic matter level and mineralization potential, as determined by an incubation test. Increases in temperature and rainfall also determine greater ANMH. The methodology developed for apparent N mineralization estimation may be applied to other crops and production regions.
Genotypic Differences in Water Use Efficiency of Common Bean under Drought Stress
Authors: Builes V. H. Ramirez , Porch T. G. , Harmsen E. W.
Published: July 2011

Common bean (Phaseolus vulgaris L.) is extensively grown in production zones where water is limiting. Crop water use efficiency is the ratio of biomass or seed yield produced per unit of water evapotranspired in a particular environment. Transpiration efficiency (TE) is the ratio of yield per unit of water transpired. The objectives of this study were to: (i) determine the water use efficiency (WUE) for six common bean genotypes (BAT 477, Morales, SEN 3, SEN 21, SER 16, and SER 21) in the greenhouse and for two genotypes in the field (Morales and SER 16) and (ii) determine TE for two common bean genotypes using estimated evapotranspiration rates in the field. Three greenhouse trials and two field trials were conducted during 3 yr in Puerto Rico. Three water levels in the greenhouse and two in the field were applied. Actual evapotranspiration was estimated using the generalized Penman–Monteith model based on aerodynamic and surface resistance, and with drainage type lysimeters in the field. Differences among genotypes for WUE were found in the greenhouse experiments, with SEN 3 and SER 21 showing superior WUE in several treatments. In the field, TE and WUE were affected by water level, and TE was consistent with previously reported coefficients for common bean.
Long‐Term Lentil Green‐Manure Replacement for Fallow in the Semiarid Northern Great Plains
Authors: Allen Brett L. , Pikul Joseph L. , Waddell Jed T. , Cochran Verlan L.
Published: July 2011

Summer fallow results in inefficient precipitation use and could potentially be replaced with a green manure (GM) crop that reduces fertilizer N application. A 12‐yr study on a Williams loam (fine‐loamy, mixed, superactive, frigid Typic Argiustoll) was used to determine GM impacts on soil‐N fertility, soil organic carbon (SOC), water use, yield, and water productivity (WP) of spring wheat (Triticum aestivum L.). Lentil (Lens culinaris Medikus cultivar Indianhead) was grown in rotation with nonfertilized spring wheat and killed either mechanically (GMMF) or chemically (GMCF). Inorganic N fertilizer treatments included annually cropped wheat (ACW), and wheat‐fallow rotations (WFR) with mechanical (MF) or chemical (CF) fallow management. Low soil nitrate during the first 5 yr of the study resulted in a 33% decrease (P < 0.05) in wheat yield in GM compared to WFR. During the latter 6 yr, wheat yield differed by 2%, due to 26% greater spring soil nitrate (0–0.6 m) in GM than WFR, and growing season change in nitrate N showed a 2.2‐fold N‐cycling advantage of GM over WFR. Water use during nonwheat periods was similar in GM and WFR when lentil was killed at full bloom, but when grown to lower pod set GM used 20% more water than WFR. After 11 yr, SOC in the surface 15 cm was 9.1% greater in treatments with chemical management than those with mechanical management. Green manure, with proper management, maintains WP and offsets fertilizer N needs after about three cropping cycles compared with traditional wheat–fallow rotations.
Economically Optimal Nitrogen Rates of Corn: Management Zones Delineated from Soil and Terrain Attributes
Authors: Jaynes Dan B. , Kaspar Thomas C. , Colvin Tom S.
Published: July 2011

Much of the NO3 found in streams in the Midwest comes from leaching of N fertilizers applied to corn (Zea mays L.). To reduce this leaching, N fertilizer must be used more effectively. Dividing fields into areas that respond more uniformly to management is one approach for improving N fertilizer use. The objective of this study was to determine and compare economically optimal N fertilizer rates for corn in a corn–soybean [Glycine max (L.) Merr.] rotation within management zones. A method based on soil and landscape characteristics was used to divide three fields into management zones roughly equivalent to toeslope, footslope, backslope, and shoulder landscape positions. We applied N fertilizer at six rates within replicated small plots (15.1 by 4.5 m) located within each management zone. Yield vs. N rate for each management zone was fitted to the Mitscherlich equation using nonlinear methods. Final Mitscherlich parameters, economically optimal N rates, and their confidence limits were computed for each management zone. Yields at the highest N rate generally followed the pattern of toeslope ≥ footslope ≥ backslope >> shoulder among the management zones. Conversely, economically optimal N rates followed the reverse pattern and varied from 23 to 247 kg ha−1. Thus, yield at the highest N rate was a poor predictor of the optimal N rate for the management zones delineated in this study and N fertilizer application would have been optimized by applying relatively less to the toeslope and footslope management zones and relatively more to the shoulder and backslope management zones.
Barley Productivity Response to Polymer‐Coated Urea in a No‐Till Production System
Authors: Blackshaw R. E. , Hao X. , Harker K. N. , O'Donovan J. T. , Johnson E. N. , Vera C. L.
Published: July 2011

Farmers are interested in more cost‐efficient and environmentally sound fertilization programs in field crops. A multi‐site study on the Canadian prairies was conducted to determine the effect of polymer‐coated urea (Environmentally Smart Nitrogen, ESN) compared with urea on weed management and barley (Hordeum vulgare L.) yield and quality. Treatments included a semi‐dwarf and tall barley cultivar, polymer‐coated urea (ESN) and urea, 100 and 150% of soil test N fertilizer rates, and 50 and 100% of registered herbicide rates. Treatments were applied to the same plots in four consecutive years. Barley yield was greater with semi‐dwarf compared with tall barley in 13 of 20 site‐years but weed biomass was greater in 7 of 18 site‐years with the semi‐dwarf cultivar. The 150% N fertilizer rate increased yield of both cultivars in 9 of 20 site‐years and of the semi‐dwarf cultivar in four additional site‐years. Barley yield was often similar with ESN and urea but ESN increased barley yield in three site‐years at both N rates, two additional site‐years at the 150% N rate, and one further site‐year with semi‐dwarf barley. Barley grain protein concentration was greater with ESN than with urea in 8 of 20 site‐years. Information gained in this study will be used to advise growers on improved barley production practices.
Organically Managed No‐Tillage Rye–Soybean Systems: Agronomic, Economic, and Environmental Assessment
Authors: Bernstein Emily R. , Posner Joshua L. , Stoltenberg David E. , Hedtcke Janet L.
Published: July 2011

A major challenge that organic grain crop growers face is weed management. The use of a rye (Secale cereale L.) cover crop to facilitate no‐tillage (NT) organic soybean [Glycine max (L.) Merr.] production may improve weed suppression and increase profitability. We conducted research in 2008 and 2009 to determine the effect of rye management (tilling, crimping, and mowing), soybean planting date (mid‐May or early June), and soybean row width (76 or 19 cm), on soybean establishment, soil moisture, weed suppression, soybean yield, and profitability. Soybean establishment did not differ between tilled and NT treatments; and soil moisture measurements showed minimal risk of a drier soil profile in NT rye treatments. Rye mulch treatments effectively suppressed weeds, with 75% less weed biomass than in the tilled treatment by mid‐July. However, by this time, NT soybean competed with rye regrowth, were deficient in Cu, and accumulated 22% as much dry matter (DM) and 28% as much N compared to the tilled treatment. Soybean row width and planting date within NT treatments impacted soybean productivity but not profitability, with few differences between mowed and crimped rye. Soybean yield was 24% less in the NT treatments than the tilled treatment, and profitability per hectare was 27% less. However, with fewer labor inputs, profitability per hour in NT rye treatments was 25% greater than in tilled soybean; in addition, predicted soil erosion was nearly 90% less. Although soybean yields were less in NT rye mulch systems, they represent economically viable alternatives for organic producers in the Upper Midwest.
Estimating Net Carbon Emissions and Agricultural Response to Potential Carbon Offset Policies
Authors: Popp Michael , Nalley Lanier , Fortin Corey , Smith Aaron , Brye Kristofor
Published: July 2011

In this study, we developed a technique for estimating soil C sequestration from crop production with detailed spatial differences in production practices, tillage effects, and soil textures often overlooked when modeling state‐level implications of climate change policies. The model also tracks C equivalent (CE) emissions from fertilizer, fuel, and agricultural chemical use. Using Arkansas as an example, a model that maximizes crop returns to producers in conjunction with C offset payments allowed estimation of probable changes in county‐level cropping patterns and income as a result of varying C prices. While income ramifications of a C‐offset climate change policy are positive, significant uncertainty about resultant greenhouse gas (GHG) effects are demonstrated. Crops included were corn (Zea mays L.), cotton (Gossypium hirsutum L.), grain sorghum [Sorghum bicolor (L.) Moench], soybean [Glycine max (L.) Merr.], rice (Oryza sativa L.) and wheat (Triticum spp.). As a result of this detailed analysis, two caveats are that (i) policy recommendations hinge on a baseline scenario that would change with changes in input and output price levels, with these interactions not modeled within, and (ii) monitoring costs of a C‐offset market could be significant.
Corn Cob Residue Carbon and Nutrient Dynamics during Decomposition
Authors: Wienhold Brian J. , Varvel Gary E. , Jin Virginia L.
Published: July 2011

The cob fraction of corn (Zea mays L.) residue has characteristics that reduce concerns associated with residue removal making it a potential biofuel feedstock. The contribution the cob makes to soil C and nutrient dynamics is unknown. A litterbag study was conducted in no‐tillage plots under irrigated and rainfed conditions in eastern Nebraska. Litterbags containing cobs were placed in corn rows on the soil surface or vertically in the 0‐ to 10‐cm soil depth following grain harvest and collected after 63, 122, 183, 246, 304, and 370 d. Samples were analyzed for dry matter, C, N, P, K, S, Ca, Mg, Fe, Mn, Cu, and Zn. Dry matter loss was greater for buried (59% loss rainfed site vs. 64% irrigated site) than surface cobs (49% loss rainfed site vs. 42% irrigated site). Cob N, P, S, content did not change over the duration of the study and these nutrients would play a limited role in nutrition for the subsequent crop. Cob K content declined exponentially over the study suggesting that cob K would be available to the subsequent crop. Cob Ca, Mg, Zn, Fe, Mn, and Cu content increased during the study representing immobilization. With the exception of K, nutrients contained in the cob are immobilized the year following harvest and play a minor role in mineral nutrition of the subsequent crop. As cellulosic conversion technology becomes available cobs represent a feedstock that can be harvested with minor effect on crop nutrient availability.
Nitrogen Availability from Poultry Litter and Pelletized Organic Amendments for Organic Rice Production
Authors: Wild Paula L. , van Kessel Chris , Lundberg Jessica , Linquist Bruce A.
Published: July 2011

Nitrogen is the most limiting nutrient in irrigated rice (Oryza sativa L.) production, and growers continue to be faced with the challenge of meeting crop N demand, particularly in organic production systems. The main objective of this study was to determine how rice yield was affected by seasonal availability of N from organic sources under continuously and noncontinuously flooded conditions. Laboratory and field experiments were conducted to determine the effectiveness of the commonly used poultry litter, pelletized organic fertilizers (blood, meat, and feather meal 13–0–0, feather meal 12–0–0, poultry litter plus feather meal 6–3–2), and (NH4)2SO4, in synchronizing the supply of mineralized N with the demand of N by rice. The N mineralization of all organic fertilizers occurred primarily during the first 53 d after planting, results which were confirmed subsequently in a laboratory incubation study. In all fields, fertilizers increased grain yield and N uptake relative to a zero N control. Relative to poultry litter, the pelletized fertilizers resulted in higher yields (9980 vs. 9267 kg ha−1), N uptake (140 vs. 114 kg ha−1), and N recovery efficiency (35 vs. 20%) in all fields. It was concluded that pelletized fertilizers were significantly more effective than poultry litter in supplying N to the crop when fields were continuously flooded. In contrast all organic fertilizers were less effective in supplying N when fields were drained for weed control due to lower N recovery efficiency (26%) and N loss through denitrification, indicating that organic fertilizer application may not be economically viable under such circumstances.
Yield and Quality of Wheat and Soybean in Sole‐ and Double‐Cropping
Authors: Caviglia Octavio P. , Sadras Victor O. , Andrade Fernando H.
Published: July 2011

In temperate environments, the wheat–soybean [Triticum aestivum L.–Glycine max (L.) Merr.] double‐crop system often improves the capture and use efficiency of radiation and water in relation to single crops. Here we assessed the yield and quality of wheat and soybean in relay and sequential double‐crops as compared with control sole‐crops in the southeastern Pampas of Argentina during two seasons (2000/2001–2001/2002). Soybean controls included crops sown on optimum dates or on dates coincident with those of double‐crops. Wheat grain yield and protein concentration were similar in both sowing arrangements of relay (skip row, where one wheat row out of four was unsown) and sequential (solid‐seeded) double‐crops (yield: 4070 vs. 4100 kg grain ha−1; protein: 164 vs. g kg−1). Yields of relay cropped soybean were 74 to 77% of their respective controls sown on the same date. In contrast, yields of sequentially cropped soybean were 85 to 110% of controls sown on the same date. The land equivalent ratio did not differ between cropping strategies and ranged from 1.58 to 1.82. In comparison to sole‐crops, double‐cropping increased grain yield and glucose equivalent yield by 58 to 82% and harvest residues by 91 to 143%. Late sowing reduced oil concentration of soybean seed in Year 2, when temperature during seed filling accounted for 58% of the variation in oil concentration. Early growing conditions were critical to the yield of double‐cropped soybean. Management of the cropping system to increase soybean shoot biomass at first flower (R1) could further enhance the production and environmental benefits of double crops in temperate environments.
In‐Season Prediction of Sugarbeet Yield, Quality, and Nitrogen Status Using an Active Sensor
Authors: Gehl Ronald J. , Boring Timothy J.
Published: July 2011

Nitrogen fertilizer management of sugarbeet (Beta vulgaris L.) continues to increase in importance with rising fertilizer costs and industry payments weighted toward crop quality. Our objective was to evaluate the use of an optical sensor for assessment of in‐season sugarbeet N status, yield, and quality prediction and total N in foliage on the day of harvest. Six N fertilizer treatments, from 0 to 225 kg N ha−1, were applied at three sites in Michigan in 2006 and four sites in 2007. Normalized difference vegetative indices (NDVIs) were measured at four growing degree day (GDD) intervals in 2006, five intervals in 2007, and at harvest in both years with a red‐band active sensor. Leaf biomass and root yield were determined at harvest, and root samples were collected for determination of sucrose content and clear juice purity. The NDVI readings were useful for differentiating control treatments from fertilized plots but were not able to identify a yield response threshold until late in the season. Midseason 1200 to 1400 GDD, 1900 to 2300 GDD, and harvest NDVI values were strongly related to recoverable white sucrose per area (R2 = 0.89, 0.87, and 0.80, respectively). Harvest NDVI was strongly related to sugarbeet vegetation total N (R2 = 0.87). Active sensing during the growing season shows promise as a means to estimate root yield and recoverable sugar in sugarbeet fields. Sensing on the day of harvest may improve rotational N management by providing an indication of N return to the cropping system.
Maize‐N: A Decision Tool for Nitrogen Management in Maize
Authors: Setiyono T. D. , Yang H. , Walters D. T. , Dobermann A. , Ferguson R. B. , Roberts D. F. , Lyon D. J. , Clay D. E. , Cassman K. G.
Published: July 2011

Nitrogen fertilizer efficiency has a large influence on profit, energy efficiency, N losses to the environment, and greenhouse gas emissions in maize (Zea mays L.) production. Our purpose was to develop a robust decision‐support tool to help inform N fertilizer recommendations and to compare performance of this tool relative to existing recommendation approaches. Maize‐N is a simulation model for estimating economically optimum N fertilizer rates (EONR) for maize. The model estimates the EONR based on uptake efficiency of the applied N, expected yield response, market prices of grain and N fertilizer, and mechanistic components of soil N mineralization. Uptake efficiency and expected yield response are derived from a database of yield response to applied N from field experiments in the United States, Asia, and South America. The model is responsive to: (i) soil properties and indigenous soil N supply capacity, (ii) local climatic conditions and yield potential, (iii) crop rotation (including type and yield of previous crop), (iv) tillage method and timing of tillage operations, and (v) fertilizer formulation, application method, and timing. Validation of Maize‐N across N management regimes and environments in the western U.S. Corn Belt indicated reasonable agreement between observed and measured values of EONR (RMSE of 21 kg N ha−1), which compares favorably with RMSE values of 33 to 61 kg N ha−1 for other methods based on empirical relationships derived from regional field tests in Kansas, Missouri, Nebraska, South Dakota, and Iowa.
Camelina Yield Response to Different Plant Populations under Dryland Conditions
Authors: McVay K. A. , Khan Q. A.
Published: July 2011

Poor stands of camelina [Camelina sativa (L.) Crantz., Brassicaceae] usually result from poor seedbed conditions or unfavorable environmental conditions. A 2‐yr field study was conducted under dryland conditions near Huntley, MT to evaluate the effects of stand reduction at rosette and bolting growth stages on camelina grain yield and quality and to determine if camelina has compensatory ability for grain yield after a stand loss. Camelina exhibited tremendous compensatory ability to maintain grain yield across a wide range of plant populations. Stand reduction up to 50% either at rosette or at bolting stage had no effect on grain yield over 2 yr. A 90% stand reduction reduced grain yield by 50% when it occurred at bolting, but only 19% when stand was reduced at rosette stage. In general, stand reduction treatments increased seed protein content while reducing seed oil content. This change in protein and oil content was consistent and greater for bolting stage stand reduction treatments. Stand reduction resulted in reduced plant height and delayed plant maturity, however the response was not consistent over years and stand reduction treatments. Stand reduction at rosette stage had little effect on camelina maturity (1–2 d), while stand reduction at bolting stage delayed maturity up to 6 d. This implies that stand loss due to hail damage or other environmental conditions at bolting or later growth stages may cause delayed and uneven maturity which may result in harvesting problems and/or increased shattering losses.
The fundamentals of the Portuguese crisis
Authors: Andrade João , Duarte Adelaide
Published: July 2011

This paper analyses the fundamentals of the Portuguese crisis. The financial
crisis of 2007 worsened and triggered the current Portuguese crisis. We argue
that the main problem the economy is facing is its output stagnation due to a
kind of Dutch disease that has created high and increasing levels of
indebtedness, low and decreasing levels of saving and has reduced Portuguese
competitiveness. Moreover, the existence of a dualist labour market and a new
wave of emigration produce inefficiency, increasing unemployment of younger
workers and the supply of human capital abroad funded by the Portuguese
taxpayers. Governance problems such as poor public budget governance and lack
of transparency and accountability are also at stake. These governance
problems must be solved to allow the economy to return to its long-run growth
path.
Credit rating agencies and moral hazard
Authors: Bozovic Milos , Urosevic Branko , Zivkovic Bosko
Published: July 2011

The failure of credit rating agencies to properly assess risks of complex
financial securities was instrumental in setting off the global financial
crisis. This paper studies the incentives of companies and rating agencies
and argues that the way the current rating market is organized may provide
agencies with intrinsic disincentives to accurately report credit risk of
securities they rate. Informational inefficiency is only enhanced when rating
agencies function as an oligopoly or when they rate structured products. We
discuss possible market and regulatory solutions to these problems.
Are the determinants of markup size industry-specific? The case of Slovenian manufacturing firms
Authors: Ponikvar Nina , Tajnikar Maks
Published: July 2011

The aim of this paper is to identify factors that affect the pricing policy
in Slovenian manufacturing firms in terms of the markup size and, most of
all, to explicitly account for the possibility of differences in pricing
procedures among manufacturing industries. Accordingly, the analysis of the
dynamic panel is carried out on an industry-by-industry basis, allowing the
coefficients on the markup determinants to vary across industries. We find
that the oligopoly theory of markup determination for the most part holds for
the manufacturing sector as a whole, although large variability in markup
determinants exists across industries within the Slovenian manufacturing. Our
main conclusion is that each industry should be investigated separately in
detail in order to assess the precise role of markup factors in the
markup-determination process.
Quantum economics
Authors: Vukotic Veselin
Published: July 2011

The globalization is breaking-down the idea of national state, which was the
base for the development of economic theory which is dominant today. Global
economic crisis puts emphasis on limited possibilities of national
governments in solving economic problems and general problems of society.
Does it also mean that globalization and global economic crisis points out
the need to think about new economic theory and new understanding of
economics? In this paper I will argue that globalization reveals the need to
change dominant economic paradigm - from traditional economic theory
(mainstream) with macroeconomic stability as the goal of economic policy, to
the ?quantum economics?, which is based on ?economic quantum? and immanent to
the increase of wealth (material and non-material) of every individual in
society and promoting set of values immanent to the wealth increase as the
goal of economic policy. Practically the question is how we can use global
market for our development!
Botrytis cinerea control and the problem of fungicide resistance
Authors: Tanovic Brankica , Hrustic Jovana , Mihajlovic Milica , Grahovac Mila , Delibasic Goran , Vuksa Petar
Published: July 2011

Botrytis cinerea, the causal agent of grey mould, greatly affects fruit,
grapevine, vegetable and ornamental crops production. It is a common causal
agent of diseases in plants grown in protected areas, as well as fruit decay
during storage and transport. The fungus invades almost all parts of the
plant in all developmental stages, and the symptoms are usually described as
grey mould, grey mildew, brown rot and seedling blight. The paper reviews the
current knowledge on control possibilities of this necrotrophic pathogen. The
attention is particularly paid to the mode of action of novel fungicides and
to the problem of resistance. It is pointed out that by limiting the number
of treatments in the growing season, avoiding the use of only one fungicide
with a high risk for resistance development, appropriate application rate and
timing, using mixtures of pesticides with different modes of action, as well
as by alternative use of pesticides from different resistance groups, a
longterm preservation of pesticide efficacy is provided.
Rimsulfuron in soil: Effects on microbiological properties under varying soil conditions
Authors: Radivojevic Ljiljana , Santric Ljiljana , Gajic-Umiljendic Jelena
Published: July 2011

The effects of rimsulfuron a sulfonylurea herbicide on the growth and
activity of soil microorganisms under laboratory conditions was investigated
in two soils. The application rates were: 0.2, 2.0 and 20.0 mg a.i kg-1 soil.
The lowest concentration tested was the label rate (0.2 mg a.i kg-1), and the
other two were ten and hundred times higher. No adverse effects on
microbiological processes were observed for the label rate. Decrease in
microbial biomass carbon, dehydrogenase activity, fungi and bacteria in
comparison with untreated control, were found at higher rates. The magnitude
of these effects were generally slight and transitory.