bluuebunny/crossref_metadata_2025 huggingface dataset:
Do Mixed‐Species Legume Fallows Provide Long‐Term Maize Yield Benefit Compared with Monoculture Legume Fallows?
Authors: Ndufa James K. , Gathumbi Stanley M. , Kamiri Hellen W. , Giller Ken E. , Cadisch Georg
Published: October 2009

The deliberate planting of fast‐growing N2–fixing legume monoculture species in rotation with cereal crops can be an important source of N for soil fertility replenishment. We hypothesized that mixed‐species fallows have a higher potential of giving long‐term residual benefits in terms of biomass, nutrients, and quality of residuals leading to long‐term nutrient supply to postfallow maize (Zea mays L.) crops. To test these hypotheses, two experiments were established in farmers' fields on very fine Kandiudalfic Eutrudox soils with monoculture and mixed‐species fallows. Treatments included: sesbania [Sesbania sesban (L.) Merr.], crotalaria (Crotalaria grahamiana Wight and Arn.), pigeonpea [Cajanus cajan (L.) Millsp.], siratro [Macroptilium atropurpureum (DC.) Urb.], and calliandra (Calliandra calothyrsus Meissn.) as monoculture‐species fallow and mixture fallows of sesbania + crotalaria, sesbania + pigeonpea, sesbania + siratro, or sesbania + calliandra compared with continuous maize cropping with or without N fertilizer, and natural weed fallow. Total aboveground biomass ranged from 4.1 to 20.5 Mg ha−1 for monoculture and 7.8 to 23.3 Mg ha−1 for mixed‐species fallows. Recyclable fallow biomass N ranged from 70 to 313 kg ha−1 and there was a positive interaction in some mixtures leading to increased N accumulation. Postfallow maize yields for fallows over five cropping seasons were 161–272% or 61–103% higher when compared with continuous maize without or with N fertilizer, respectively. Long‐term postfallow effects on maize yield were linearly related to the amount of recycled fallow N yield. Thus, choice of fallow species to mix should be primarily driven by a better risk management strategy and an increased basket of multiple products and services.
Corn Response to Competition: Growth Alteration vs. Yield Limiting Factors
Authors: Clay S. A. , Clay D. E. , Horvath D. P. , Pullis J. , Carlson C. G. , Hansen S. , Reicks G.
Published: October 2009

Competition mechanisms among adjacent plants are not well understood. This study compared corn growth and yield responses to water, N, and shade at 74,500 plants ha−1 (1×) with responses to water and N when planted at 149,000 plant ha−1. Plant biomass, leaf area, chlorophyll content, reflectance, and enzyme expression (transcriptome analysis) were measured at V‐12. Grain and stover yields were measured with grain analyzed for 13C isotopic discrimination (Δ) and N concentration. At V‐12, 60% shade plants had increased chlorophyll and reduced leaf area and height compared to full sun plants. In the 2× treatment, plants had 11% less chlorophyll than 1× plants with leaf area and height similar to 60% shade plants. At harvest, plants in the 2× treatment were smaller, had increased water and N use efficiency, and an 11% per hectare yield increase compared with the 1× unstressed treatment. Per‐plant yields from 60% shade and 2× treatments were 50% less than 1× unstressed treatment. Yield reduction in shaded plants was attributed to light stress. Lower yield in the 2× treatment was attributed to a population‐density induced 20% decrease in the red/near‐infrared (NIR) ratio, which resulted in downregulation of C4 carbon metabolism enzymes (phosphoenolpyruvate carboxykinase, phosphoenolpyruvate carboxylase, and pyruvate orthophosphate dikinase). Although the net impact of high plant density and shade stress on per‐plant yield were similar, the stress compensation mechanisms differed.
No‐Tillage Improves Broomrape Control with Glyphosate in Faba‐Bean
Authors: López‐Bellido R. J. , Benítez‐Vega J. , López‐Bellido L.
Published: October 2009

Broomrape (Orobanche crenata Forsk.) causes considerable losses in faba‐bean (Vicia faba L.) production in the Mediterranean region. The application of an ultra‐low glyphosate rate at an early broomrape parasitic phase, i.e., tubercle development, is the most common control system. This study sought to determine the effect of tillage system and glyphosate application on broomrape infestation, faba‐bean yield, and yield components. A field experiment was performed over a 3‐yr period in Cordoba (Spain) in a rainfed Vertisol. Experimental factors and respective treatments were: tillage system (no‐tillage vs. conventional tillage) and glyphosate application (none vs. 0.113 kg a.i. ha−1). Year × tillage system × glyphosate interactions were apparent in the results. Averaging over 3‐yr, no‐tillage with glyphosate application reduced weed infestation (42 plants m−2) and increased faba‐bean seed yield (1.73 Mg ha−1) in comparison with conventional tillage with glyphosate application (10 broomrape plants m−2, and 1.14 Mg ha−1 of seed yield). When glyphosate was not applied, broomrape density varied from 80 to 45 plants m−2 and faba‐bean seed yield from 0.50 to 1.24 Mg ha−1 for tillage and no‐tillage systems, respectively. Within each tillage system, glyphosate application always reduced broomrape infestation and increased seed yield. Even in the absence of glyphosate application, seed yields were higher under no‐tillage than under conventional tillage with herbicide application over 2 yr. Pod m−2 was the yield component most affected by broomrape infestation. No‐tillage is an important tool for broomrape control, but the addition of glyphosate application substantially enhances the degree of control.
Sand Abrasion Injury and Biomass Partitioning in Cotton Seedlings
Authors: Baker Jeffrey T. , McMichael Bobbie , Burke John J. , Gitz Dennis C. , Lascano Robert J. , Ephrath Jhonathan E.
Published: October 2009

Wind blown soil particle abrasion negatively impacts millions of hectares of crops annually. The goal of this study was to examine the effects of wind and wind blown sand abrasion damage on cotton (Gossypium hirsutum L.) seedling biomass partitioning to leaves, stems, and roots. Seedlings of three cotton cultivars were exposed to no wind (untreated controls) or sand abrasive flux densities of 0, 0.1, 0.25, 0.35, and 0.5 g cm−1 width s−1 at a wind velocity of 13.4 m s−1 in a suction‐type laboratory wind tunnel. Plants were destructively sampled at the time of the sand abrasion treatment and at approximately 2 and 4 wk after exposure. These three sampling dates provided two time intervals for assessing the amount of plant damage and regrowth using classical growth analysis. With increasing sand, abrasive flux density, whole plant, leaf, stem, and root biomass, as well as leaf area, were all reduced in both harvest intervals (P ≤ 0.05). Net assimilation rate (NAR) accounted for 96 and 75% of the variability in relative growth rate (RGR) in the first and second harvest intervals, respectively, with small but significant differences in leaf area ratio (LAR). Increasing plant damage caused by sand abrasion treatment resulted in preferential biomass partitioning to the damaged stems rather than roots during the first harvest interval, while a much more stable allometric allocation of biomass among plant organs was observed in the second harvest interval.
Soil Quality and Corn Yield under Crop–Livestock Integration in Illinois
Authors: Maughan Matthew W. , Flores João Paulo C. , Anghinoni Ibanor , Bollero German , Fernández Fabián G. , Tracy Benjamin F.
Published: October 2009

Compared with traditional cropping systems, integrated crop–livestock systems have shown greater efficiency in improving soil quality and crop yield. The objective of this study was to determine how an integrated crop–livestock system affected soil properties and corn (Zea mays L.) yield when compared with continuous corn (CC). The study was conducted from 2004–2008 on a large‐scale research farm located near Pana, IL, USA. We evaluated the following soil and crop variables: soil organic matter (SOM) fractions, total nitrogen (TN) and total organic carbon (TC), soil microbial biomass carbon (SMBC), water aggregate stability, soil penetration resistance (PR), and corn yield. Three treatments were used in this study: winter cover crops (WCCs) and cool‐season pastures (CSP), considered integrated system treatments and a nonintegrated CC monoculture. In the integrated system, CSP and WCC treatments combined, had significantly higher TN (P = 0.0926) than CC. Water aggregate stability was also higher in the integrated system (P = 0.0039). Greater percentages of TC and TN were represented by particulate organic matter (POM) POM‐N and POM‐C in the WCC treatment, followed by CSP, and CC. The PR for CSP (928 kPa) was not significantly different than WCC (921 kPa). However, both were significantly different than CC (655 kPa). Averaged across years, corn grain yield for WCC (11.5 Mg ha−1) was significantly higher than CC (10.8 Mg ha−1) (P = 0.0780). These results confirm that WCC and CSP used within integrated crop–livestock systems should improve soil quality, SOM dynamics, and crop yield despite moderate soil compaction caused from cattle presence.
Maize Morphophysiological Responses to Intense Crowding and Low Nitrogen Availability: An Analysis and Review
Authors: Boomsma Christopher R. , Santini Judith B. , Tollenaar Matthijs , Vyn Tony J.
Published: October 2009

Mounting concerns over the cost and environmental impact of N fertilizer combined with progressively higher plant densities in maize (Zea mays L.) production systems make progress in maize N use efficiency (NUE) and N stress tolerance essential. The primary objectives of this 3‐yr field study were to (i) evaluate the N responsiveness, NUE, and N stress tolerance of multiple modern maize genotypes using suboptimal, optimal, and supraoptimal plant densities (54,000, 79,000, and 104,000 plants ha−1, respectively) with three levels of side‐dress N (0, 165, and 330 kg N ha−1), (ii) identify key morphophysiological responses to the simultaneous stresses of intense crowding and low N availability, and (iii) consider our results with extensive reference to literature on maize morphophysiological responses to plant crowding and N availability. At optimal and supraoptimal plant densities, maize receiving 165 kg ha−1 of side‐dress N displayed strong N responsiveness, high NUE, pronounced crowding tolerance, and plant density independence. However, crowding tolerance was contingent on N application. Relative to less crowded, N‐fertilized environments, the 104,000 plants ha−1, 0 kg N ha−1 treatment combination exhibited (i) reduced pre‐ and postanthesis plant height (PHT), stem diameter (SD), and total biomass; (ii) greater preflowering leaf senescence and lower R1 leaf areas at individual‐leaf, per‐plant, and canopy levels; (iii) enhanced floral protandry; (iv) lower pre‐ and postanthesis leaf‐chlorophyll content; (v) lower per‐plant kernel number (KNP), individual kernel weight (KW), grain yield per plant (GYP), andharvest index per plant (HIP); and (vi) enhanced per‐plant grain yield variability (GYCV). Genetic efforts to improve high plant density tolerance should, therefore, simultaneously focus on enhancing NUE and N stress tolerance.
Selecting Zinc‐Efficient Wheat Genotypes with High Grain Yield Using a Stress Tolerance Index
Authors: Khoshgoftarmanesh Amir H. , Sadrarhami Azadeh , Sharifi Hamid R. , Afiuni Davoud , Schulin Rainer
Published: October 2009

There is no reliable indicator for identifying Zn‐deficiency tolerant genotypes with high grain yield. The aim of this investigation was to compare the grain yield response of 30 spring and 20 winter bread wheat (Triticum aestivumL.) genotypes to Zn fertilization under field condition and to select high grain yield Zn‐deficiency tolerant genotypes using a stress tolerance indicator. The stress tolerance indicator is a stress tolerance index (STI) used to identify genotypes that produce high yields under both nonstress and stress environments. Two individual trials, each consisting of two field plot experiments, were conducted during the 2006–2007 growing season. Spring wheat genotypes (Trial l) and winter wheat genotypes (Trial 2) were planted in two different locations. Two Zn rates, 0 and 40 kg Zn ha−1, using ZnSO4·7H2O were evaluated. Grain yield varied significantly (P< 0.01) among wheat genotypes regardless of Zn treatment. Application of Zn fertilizer increased grain yield of spring wheat genotypes an average of 883 and 913 kg ha−1in Karaj and Isfahan locations, respectively, although considerable variation was found among genotypes in response to Zn fertilization. Zinc efficiency (ZE) significantly differed among wheat genotypes and ranged from 69% to 95% for spring wheat and from 62% to 105% for winter wheat genotypes. Most of the wheat genotypes were placed in group A (genotypes that are not affected by stress) and D (genotypes with low yield in both stress and nonstress environments) based on the STI. The results showed that the STI could be a better selection criterion compared with ZE for identifying high‐yield stress‐tolerant genotypes.
Tillage Requirements for Integrating Winter‐Annual Grazing in Peanut Production: Plant Water Status and Productivity
Authors: Siri‐Prieto G. , Reeves D. W. , Raper R. L.
Published: October 2009

The use of crop rotation systems involving winter‐annual grazing can help peanut (Arachis hypogaea L.) producers increase profitability, although winter‐annual grazing could result in excessive soil compaction, which can severely limit yields. We conducted a 3‐yr field study on a Dothan loamy sand in southeastern Alabama to develop a conservation tillage system for integrating peanut with winter‐annual grazing of stocker cattle under dryland conditions. Winter‐annual forages and tillage systems were evaluated in a strip‐plot design, where winter forages were oat (Avena sativa L.) and annual ryegrass (Lolium mutiflorum L.). Tillage systems included moldboard and chisel plowing, and combinations of noninversion deep tillage (none, in‐row subsoil, or paratill) with/without disking. We evaluated soil water content, peanut leaf stomatal conductance, plant density, peanut yield, peanut net return, and total system annual net return. Peanut following oat increased soil water extraction (15%), stands (12%), and yields (21%) compared with peanut following ryegrass. Strict no‐till resulted in the lowest yields (2.29 Mg ha−1, 42% less than the mean) and noninversion deep tillage (especially in‐row subsoil) was required to maximize water use and yields with conservation tillage. Net return from annual grazing ($185 ha−1, USD) represented 40% of the total return for the best treatment (no‐tillage with in‐row subsoil following oat = $462 ha−1). Integrating winter‐annual grazing in this region using noninversion deep tillage following oat in a conservation tillage system can benefit peanut growers, allowing extra income without sacrificing peanut yields.
Defoliation Management of Bahiagrass Germplasm Affects Cover and Persistence‐Related Responses
Authors: Interrante S. M. , Sollenberger L. E. , Blount A. R. , Coleman S. W. , White U. R. , Liu K.
Published: October 2009

Bahiagrass (Paspalum notatum Flügge) cultivars are valued for their persistence under grazing and low management inputs. However, they are daylength‐sensitive and have minimal cool‐season production, resulting in high winter feeding costs in forage‐based livestock systems. New germplasm is less daylength‐sensitive, possesses greater cold tolerance, and is more productive during the cool season, but its persistence under defoliation is unknown. A field experiment quantified cover and persistence‐related responses of photoperiod‐sensitive bahiagrass (diploids ‘Pensacola’ and ‘Tifton 9’ and tetraploids ‘Argentine’ and Tifton 7) and a less photoperiod‐sensitive, cold‐adapted (PCA) diploid bahiagrass (Cycle 4) at two stubble heights (4 and 8 cm) and two harvest frequencies (7 and 21 d). Argentine cover was unaffected by defoliation treatments, but harvesting every 7 d to 4 cm for 3 yr resulted in <40% cover for both Tifton 9 and Cycle 4. Averaging over defoliation treatments, stem base mass of Pensacola and Argentine was 60% greater than Cycle 4. At 4‐ and 8‐cm stubble heights, the advantage was 86 and 41%, respectively. When defoliated every 7 d, Pensacola and Argentine stem base mass was 125% greater than Cycle 4, while the difference was 23% for the 21‐d treatment. Similar but less‐pronounced responses were observed for N and total nonstructural carbohydrate (TNC) content of stem base and root + rhizome fractions. Defoliation management of PCA Cycle 4 is more critical than for Pensacola and Argentine bahiagrass, and longer regrowth intervals and taller residual heights may be required to ensure its persistence.
Crop Genotype and Plant Population Density Impact Flowering Phenology and Synchrony between Cropped and Volunteer Spring Wheat
Authors: Willenborg Christian J. , Luschei Ed C. , Brûlé‐Babel Anita L. , Van Acker Rene C.
Published: October 2009

Wheat (Triticum aestivum L.) is one of many crops into which novel traits have been incorporated using recombinant DNA technology, and thus may require segregation from nontransgenic wheat. Volunteer wheat populations, which cannot be selectively removed from wheat crops, pose a challenge to segregation because they may serve to facilitate trait movement. However, diverse flowering phenologies among wheat genotypes planted at various densities may result in flowering asynchrony, thus minimizing pollen‐mediated gene flow (PMGF). We tested this theory with a comparative analysis that examined the influence of crop plant population density, genotype, and height on flowering phenology and synchrony between volunteer and cropped wheat populations. We found that time from crop sowing to first flower, peak flowering, and flowering cessation varied significantly among genotypes. Increasing crop plant population density resulted in accelerated crop flowering for all genotypes, but had little effect on flowering synchrony. Although not always significant, the time interval from sowing to 5, 50, and 95% flowering, as well as the flowering duration of the volunteer population, were also greater at low crop plant population densities. Synchronicity of flowering varied among genotypes, with tall genotypes consistently exhibiting more flowering synchrony with volunteer wheat than short genotypes. However, the response of flowering synchrony to height may have been a product of the genotypes tested and further study to confirm these results is needed. The results of this study suggest that, despite a short flowering period, there is considerable potential for flowering synchrony between cropped and volunteer wheat populations. Nevertheless, opportunity exists to reduce flowering synchrony between cropped and volunteer wheat populations by utilizing genotypic variation for flowering phenology to minimize flowering overlap, provided that an adequate crop plant population density is attained.
Nitrogen Fixation of Sulla under Mediterranean Conditions
Authors: Sulas Leonardo , Seddaiu Giovanna , Muresu Rosella , Roggero Pier Paolo
Published: October 2009

Sulla coronaria (L.) B.H. Choi & H. Ohashi (=Hedysarum coronarium L.) is a Mediterranean forage legume grown extensively in rainfed Italian environments. Here we report the field quantification of its seasonal and annual N fixation, using the 15N isotopic dilution (ID) method, the influence of various nonfixing reference species on these estimates, and the allocation of fixed N between the aerial and the belowground biomass. Parallel experiments were conducted over two biennial crop cycles at two Italian locations (Sassari and Ancona), characterized by sandy‐loam to heavy clay‐loam calcareous soils. The proportion of nitrogen derived from the atmosphere (%Ndfa) present in the aerial biomass reached 78.2% at Sassari and 82.7% at Ancona, with no significant effect of the identity of the nonfixing reference species. At Sassari, the amount of fixed N present in the aerial dry matter (DM) of sulla was 187 kg ha−1 in the first crop cycle, and 265 kg ha−1 in the second, while the equivalent N yields at Ancona were 350 and 170 kg ha−1. The relationship between the quantity of fixed N in the aerial biomass and the aerial DM yield of sulla was significant and not site‐specific, realizing an equivalence of about 1.8 kg ha−1 of fixed N per 100 kg ha−1 of aerial DM. The relative contribution of the root biomass to the amount of fixed N was on average 4%. The N balance of sulla at the end of the second crop cycle was negative, but the N sparing effect compared with the nonfixing species ranged from 65 to 175 kg ha−1
Italian Ryegrass Management Effects on Nitrogen Supply to a Subsequent Potato Crop
Authors: Zebarth B. J. , Arsenault W. J. , Moorehead S. , Kunelius H. T. , Sharifi M.
Published: October 2009

There is increasing use of Italian ryegrass (Lolium multiflorum Lam.) as a green manure in potato (Solanum tuberosum L.) rotations; however, effects of its management on soil N supply to the subsequent potato crop are unknown. Fertilizer N management and plow‐down date for a preceding Italian ryegrass crop, ‘Lemtal’, on soil N supply to a subsequent potato crop, ‘Russet Burbank’, was determined over 2 yr. Application of N at 150 to 188 kg N ha−1 to ryegrass increased dry matter yield and N uptake of aboveground forage and stubble (i.e., stubble, crown, and large root) tissue. Delaying plow‐down from early September to early November increased dry matter yield and N uptake of stubble tissue, but not aboveground forage. Apparent recovery of applied N in harvested forage and stubble tissue averaged 55 and 12%, respectively. High N application to the ryegrass increased soil N supply to the subsequent unfertilized potato crop as indicated by increased tuber yield, mean tuber weight, and plant (i.e., vines plus tubers) dry matter yield and N uptake. However, the increase in soil N supply (i.e., N uptake of unfertilized potato plants at vine desiccation) was small (<20 kg N ha−1). Apparent recovery of N applied to the ryegrass crop in unfertilized potato plants was low (10%). Delayed ryegrass plow‐down had no effect on soil N supply to the subsequent potato crop. Italian ryegrass green manure crop can be effective in increasing soil organic matter inputs but has limited short‐term effects on soil N supply for potato.
Performance of Solid‐State Sensors for Continuous, Real‐Time Measurement of Soil CO2 Concentrations
Authors: Young Stephen L. , Pierce Francis J. , Streubel Jason D. , Collins Harold P.
Published: October 2009

Recent advances in sensor technology provide a robust capability for continuous measurement of soil gases. The performance of solid‐state CO2 sensors (Model GMM220 series, Vaisala, Inc., Helsinki, Finland) was evaluated in laboratory, greenhouse, and irrigated winter wheat (Triticum aestivum L.). In ambient CO2 concentration, the GMM222 sensor averaged 427 ± 8.3 μL L−1. Under variable CO2 concentrations, the sensor was slightly lower than concentrations measured with an infrared gas analyzer (IRGA). In greenhouse pots planted with triticale (Triticale hexaploide Lart.) and an agricultural field of irrigated winter wheat, soil CO2 concentration exceeded the 10,000 μL L−1 limit of the GMM222. Alternatively, the GMM221 sensor, designed to measure between 0 and 20,000 μL L−1, showed soil CO2 concentrations were between 14,000 and 16,000 μL L−1. The GMM222 accurately measures real‐time soil CO2 concentrations under field conditions that were within the sensor detection limit. However, periods of high biological soil activity require the GMM221 sensor with a higher detection limit.
Stacked Corn Hybrids Show Inconsistent Yield and Economic Responses in New York
Authors: Cox William J. , Hanchar John , Shields Elson
Published: October 2009

Stacked (two to three transgenic traits) corn (Zea mays L.) hybrids represented 40% of U.S. corn in 2008, despite limited agronomic studies. Field‐scale studies were conducted on four farms in New York for 2 yr to evaluate the agronomics and economics of double‐stacked {glyphosate resistance and Bt (Bacillus thuringiensis) European corn borer [Ostrinia nubilalis (Hübner)] trait} hybrids when following soybean [Glycine Max (L.) Merr.], as well as triple‐stacked [additional Bt corn rootworm (Diabrotica spp.) trait] hybrids in continuous corn. Stacked hybrids vs. near‐isolines had mostly lower weed densities, root damage ratings, and stalk lodging under generally low pest and lodging conditions in both rotations. Double‐stacked hybrids vs. near‐isolines yielded similarly when following soybean, but 5.7 and 3.6% higher at two sites where lodging exceeded 11%, and similarly at two sites where lodging averaged <3% in near‐isolines in continuous corn. Triple and double‐stacked hybrids yielded similarly. Grain moisture averaged 15 g kg−1 greater in stacked hybrids vs. near‐isolines in both rotations, but similarly between double and triple‐stacked hybrids in continuous corn. Partial returns had site × hybrid trait interactions in both rotations as increased yield revenue offset increased drying costs for double‐stacked hybrids vs. near‐isolines for three site‐rotation comparisons, resulting in $45 to $89 ha−1 profit gain, but not for two‐site rotation comparisons, resulting in $47 to $71 ha−1 profit loss. If stacked hybrids with the Bt corn borer trait have higher grain moisture, growers in northern latitudes should balance potential corn borer occurrence against increased drying costs.
Elevating Model Predictive Control Using Feedforward Artificial Neural Networks: A Review
Authors: Arumugasamy Senthil Kumar , Ahmad Zainal
Published: October 2009

Process control in the field of chemical engineering has always been a challenging task for the chemical engineers. Hence, the majority of processes found in the chemical industries are non-linear and in these cases the performance of the linear models can be inadequate. Recently a promising alternative modelling technique, artificial neural networks (ANNs), has found numerous applications in representing non-linear functional relationships between variables. A feedforward multi-layered neural network is a highly connected set of elementary non-linear neurons. Model-based control techniques were developed to obtain tighter control. Many model-based control schemes have been proposed to incorporate a process model into a control system. Among them, model predictive control (MPC) is the most common scheme. MPC is a general and mathematically feasible scheme to integrate our knowledge about a target, process controller design and operation, which allows flexible and efficient exploitation of our understanding of a target, and thus produces optimal performance of a system under various constraints. The need to handle some difficult control problems has led us to use ANN in MPC and has recently attracted a great deal of attention. The efficacy of the neural predictive control with the ability to perform comparably to the non linear neural network strategy in both set point tracking and disturbance rejection proves to have less computation expense for the neural predictive control. The neural network model predictive control (NNMPC) method has less perturbations and oscillations when dealing with noise as compared to the PI controllers.
Histological Course of Nonalcoholic Fatty Liver Disease in Japanese Patients
Authors: Hamaguchi Erika , Takamura Toshinari , Sakurai Masaru , Mizukoshi Eishiro , Zen Yoh , Takeshita Yumie , Kurita Seiichiro , Arai Kuniaki , Yamashita Tatsuya , Sasaki Motoko , Nakanuma Yasuni , Kaneko Shuichi
Published: October 2009

OBJECTIVE

The goal of this study was to examine whether metabolic abnormalities are responsible for the histological changes observed in Japanese patients with nonalcoholic fatty liver disease (NAFLD) who have undergone serial liver biopsies.

RESEARCH DESIGN AND METHODS

In total, 39 patients had undergone consecutive liver biopsies. Changes in their clinical data were analyzed, and biopsy specimens were scored histologically for stage.

RESULTS

The median follow-up time was 2.4 years (range 1.0–8.5). Liver fibrosis had improved in 12 patients (30.7%), progressed in 11 patients (28.2%), and remained unchanged in 16 patients (41%). In a Cox proportional hazard model, decrease in A1C and use of insulin were associated with improvement of liver fibrosis independent of age, sex, and BMI. However, ΔA1C was more strongly associated with the improvement of liver fibrosis than use of insulin after adjustment for each other (χ2; 7.97 vs. 4.58, respectively).

CONCLUSIONS

Tight glycemic control may prevent histological progression in Japanese patients with NAFLD.
Proinflammatory Modulation of the Surface and Cytokine Phenotype of Monocytes in Patients With Acute Charcot Foot
Authors: Uccioli Luigi , Sinistro Anna , Almerighi Cristiana , Ciaprini Chiara , Cavazza Antonella , Giurato Laura , Ruotolo Valeria , Spasaro Francesca , Vainieri Erika , Rocchi Giovanni , Bergamini Alberto
Published: October 2009

OBJECTIVE

Despite increased information on the importance of an inappropriate inflammatory response in the acute Charcot process, there has been no previous attempt to define the specific pathways that mediate its pathogenesis. Here, the role played by monocytes was analyzed.

RESEARCH DESIGN AND METHODS

The immune phenotype of peripheral monocytes was studied by fluorescence-activated cell sorter analysis comparing patients with acute Charcot (n = 10) in both the active and recovered phase, diabetic patients with neuropathy (with or without osteomyelitis), and normal control subjects.

RESULTS

When compared with diabetic control subjects and healthy subjects, monocytes from acute Charcot patients showed a proinflammatory immune phenotype characterized by increased production of proinflammatory cytokines, reduced secretion of anti-inflammatory cytokines, increased expression of surface costimulatory molecules, and increased resistance to serum withdrawal-induced apoptosis. In addition, the pattern of circulating cytokines confirmed activation of proinflammatory cytokines. No modulation of the monocyte phenotype was documented in diabetic control subjects and healthy subjects, thus indicating that the proinflammatory alterations of monocytes are specific and causative of acute Charcot.

CONCLUSIONS

Together, these data provide evidence for the role of proinflammatory changes in the immune phenotype of monocytes in the pathogenesis of acute Charcot. These alterations may explain the abnormally intense and prolonged inflammatory response that characterizes this disorder and may represent a potential therapeutic target for specific pharmacological interventions.
Hormonal and Metabolic Factors Associated With Variations in Insulin Sensitivity in Human Pregnancy
Authors: McIntyre H. David , Chang Allan M. , Callaway Leonie K. , Cowley David M. , Dyer Alan R. , Radaelli Tatjana , Farrell Kristen A. , Huston-Presley Larraine , Amini Saeid B. , Kirwan John P. , Catalano Patrick M. ,   for the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study Cooperative Research Group
Published: October 2009

OBJECTIVE

The objective of this study was to determine maternal hormonal and metabolic factors associated with insulin sensitivity in human pregnancy.

RESEARCH DESIGN AND METHODS

This was a prospective observational cross-sectional study of 180 normal pregnant women, using samples collected at the time of a blinded oral glucose tolerance test (OGTT) between 24 and 32 weeks' gestation as an ancillary to the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study. The study was conducted at two public university teaching hospitals, Cleveland, Ohio, and Brisbane, Australia. Fasting maternal serum cholesterol, triglycerides, free fatty acids, insulin, leptin, tumor necrosis factor-α, placental growth hormone (PGH), insulin-like growth factors (IGFs) 1 and 2, and insulin-like growth factor binding proteins (IGFBPs) 1 and 3 were assayed. Correlation and multiple regression analyses were used to determine factors associated with maternal insulin sensitivity (IS) estimated using both OGTT-derived (ISOGTT) and fasting (using the homeostasis model assessment [HOMA]; ISHOMA) insulin and glucose concentrations.

RESULTS

Insulin sensitivity correlated (r = x and y for ISOGTT and ISHOMA, respectively) with fasting maternal serum leptin (−0.44 and −0.52), IGFBP1 (0.42 and 0.39), and triglycerides (−0.31 and −0.27). These factors were significantly associated with insulin sensitivity in multiple regression analyses (adjusted R2 0.44 for ISOGTT and ISHOMA). These variables explained more than 40% of the variance in estimates of insulin sensitivity.

CONCLUSIONS

Maternal hormonal and metabolic factors related to the placenta, adipose tissue, and the growth hormone axis are associated with the variation in insulin sensitivity seen during normal human pregnancy.
Performance Characteristics of the New Definition of Diabetes
Authors: Lorenzo Carlos , Haffner Steven M.
Published: October 2009

OBJECTIVE

A1C ≥6.5% has been recently proposed as the defining criterion for diabetes. However, performance characteristics of this definition have not been described.

RESEARCH DESIGN AND METHODS

In the Insulin Resistance Atherosclerosis Study, we compared new to previous definitions of diabetes: 1999 World Health Organization (DM1999WHO) and 2003 American Diabetes Association based on fasting glucose alone (DMFPG126).

RESULTS

Participants with A1C ≥6.5%, DM1999WHO, and DMFPG126 were 44 (5.2%), 132 (15.4%), and 61 (7.1%), respectively. In individuals with DM1999WHO, mean, median, and interquartile range of A1C were 6.3, 5.9, and 5.5–6.6%, respectively; in individuals with DMFPG126, mean, median, and interquartile range of A1C were 7.0, 6.6, and 6.0–7.1%.

CONCLUSIONS

A1C ≥6.5% identifies fewer individuals than DM1999WHO or DMFPG126. Studies are needed to determine that A1C ≥6.5% compromises neither blood pressure and lipid management in early diabetes nor the implementation of lifestyle interventions for diabetes prevention.
Influence of Verbal Recall of a Recent Stress Experience on Anxiety and Desire for Cocaine in Non‐Treatment Seeking, Cocaine‐Addicted Volunteers
Authors: De La Garza Richard , Ashbrook Liza H. , Evans Sarah E. , Jacobsen Caitlin A. , Kalechstein Ari D. , Newton Thomas F.
Published: October 2009

It has long been postulated that stress increases the risk of drug abuse and relapse. The principal goal of this project was to evaluate the effects of verbal recall of a recent stress experience (specifically meaningful to each individual) on physiological and subjective measures in cocaine‐addicted participants. Subjects described a recent stressful non‐drug‐related experience and a neutral non‐stressful experience, and then completed mood and drug effect questionnaires, while heart rate and blood pressure were recorded. Participants (N = 25) were predominantly African American and male. As a group, participants used cocaine for more than 15 years and ∼18 of the last 30 days, and a majority reported use of nicotine and/or alcohol. All participants were evaluated during a time in which they tested positive for cocaine metabolite. On a scale of 1–10, participants reported their verbal recall of a recent stress event as highly stressful and their verbal recall of a recent neutral event as non‐stressful (p < 0.0001). The self‐reported vividness of this recall was high (>8 out of 10) for both the stress and neutral events. Heart rate and systolic and diastolic blood pressure did not differ after verbal recall of either stress or neutral events. Similarly, self‐reported subjective effects (including ratings of anxiety and craving for cocaine) did not differ after verbal recall of either stress or neutral events. In summary, despite the fact that participants recounted highly stressful and vivid memories, this experience did not elicit significant changes in cardiovascular or subjective effects. These data suggest that simply recalling a stressful event may not be a sufficient enough stimulus to contribute to craving or relapse in cocaine‐addicted individuals.
Effects of a Diagnosis or Family History of Alcoholism on the Taste Intensity and Hedonic Value of Sucrose
Authors: Tremblay Kristen A. , Bona Jessica M. , Kranzler Henry R.
Published: October 2009

Given inconsistent findings in published studies, we examined whether a personal lifetime history of alcohol dependence (AD) or a parental history of alcoholism affected preference for sweet solutions. Ninety‐three alcohol‐dependent subjects rated the intensity and hedonic value of five different sucrose solutions, which was compared with similar data from 122 subjects screened to exclude alcohol dependence. The effect of a family history of alcoholism (FH) was examined in the AD group. Neither the diagnosis of AD nor a family history of alcoholism was associated with ratings of sweetness intensity or sweet preference. These findings do not support the hypothesis that sucrose preference is positively associated with either a personal lifetime history of AD or a family history of alcoholism.
The Variety of Ecstasy/MDMA Users: Results from the National Epidemiologic Survey on Alcohol and Related Conditions
Authors: Wu Li‐Tzy , Parrott Andy C. , Ringwalt Christopher L. , Yang Chongming , Blazer Dan G.
Published: October 2009

This study investigates the potential heterogeneity of ecstasy or MDMA (3,4‐methylenedioxy‐N‐methylamphetamine) users. Data came from the 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Latent class analysis (LCA) and multinomial logistic regression procedures were used to identify subtypes of ecstasy users. Approximately 1.6% (n = 562) of adult participants (N = 43,093) reported lifetime ecstasy use. LCA identified three subtypes of ecstasy users. Class 1 exhibited pervasive use ofmost drug classes (ecstasy‐polydrug users, 37%). Class 2 reported a high rate of use of marijuana and cocaine and a moderate use of amphetamines (ecstasy‐marijuana‐stimulant users, 29%). Class 3 was characterized by a high rate of use of marijuana and a low use ofprimarily prescription‐type drugs (ecstasy‐marijuana users, 34%). Subtypes were distinguished by family income, history ofsubstance abuse treatment, and familial substance abuse. Class 1 exhibited the highest prevalence of disorders related to the use of marijuana (77%), tobacco (66%), amphetamines (36%), opioids (35%), sedatives (31%), and tranquilizers (30%). The recent resurgence in ecstasy use among adults underscores the need to monitor trends in its use.
Liver Cell Transplantation: Basic Investigations for Safe Application in Infants and Small Children
Authors: Meyburg Jochen , Alexandrova Krassimira , Barthold Marc , Kafert-Kasting Sabine , Schneider Andrea S. , Attaran Masoumeh , Hoerster Friederike , Schmidt Jan , Hoffmann Georg F. , Ott Michael
Published: October 2009

Liver cell transplantation (LCT) is a very promising method for the use in pediatric patients. It is significantly less invasive than whole organ transplantation, but has the potential to cure or at least to substantially improve severe disorders like inborn errors of metabolism or acute liver failure. Prior to a widespread use of the technique in children, some important issues regarding safety and efficacy must be addressed. We developed a mathematical model to estimate total hepatocyte counts in relation to bodyweight to make possible more appropriate dose calculations. Different liver cell suspensions were studied at different flow rates and different catheter sizes to determine mechanical damage of cells by shear forces. At moderate flow rates, no significant loss of viability was observed even at a catheter diameter of 4.2F. Addition of heparin to the cell suspension is favored, which is in contrast to previous animal experiments. Mitochondrial function of the hepatocytes was determined with the WST-1 assay and was not substantially altered by cryopreservation. We conclude that especially with the use of small catheters, human LCT should be safe and efficient even in small infants and neonates.
Reversal of Dopaminergic Degeneration in a Parkinsonian Rat following Micrografting of Human Bone Marrow-Derived Neural Progenitors
Authors: Glavaski-Joksimovic Aleksandra , Virag Tamas , Chang Qin A. , West Neva C. , Mangatu Thomas A. , McGrogan Michael P. , Dugich-Djordjevic Millicent , Bohn Martha C.
Published: October 2009

Parkinson's disease (PD) is a common neurodegenerative disease characterized by the selective loss of dopaminergic (DA) neurons in the midbrain. Various types of stem cells that have potential to differentiate into DA neurons are being investigated as cellular therapies for PD. Stem cells also secrete growth factors and therefore also may have therapeutic effects in promoting the health of diseased DA neurons in the PD brain. To address this possibility in an experimental model of PD, bone marrow-derived neuroprogenitor-like cells were generated from bone marrow procured from healthy human adult volunteers and their potential to elicit recovery of damaged DA axons was studied in a partial lesion rat model of PD. Following collection of bone marrow, mesenchymal stem cells (MSC) were isolated and then genetically modified to create SB623 cells by transient transfection with the intracellular domain of the Notch1 gene (NICD), a modification that upregulates expression of certain neuroprogenitor markers. Ten deposits of 0.5 μl of SB623 cell suspension adjusted from 6,000 to 21,000 cells/μl in PBS or PBS alone were stereotaxically placed in the striatum 1 week after the nigrostriatal projection had been partially lesioned in adult F344 rats by injection of 6-hydroxydopamine (6-OHDA) into the striatum. At 3 weeks, a small number of grafted SB623 cells survived in the lesioned striatum as visualized by expression of the human specific nuclear matrix protein (hNuMA). In rats that received SB623 cells, but not in control rats, dense tyrosine hydroxylase immunoreactive (TH-ir) fibers were observed around the grafts. These fibers appeared to be rejuvenated host DA axons because no TH-ir in soma of surviving SB623 cells or coexpression of TH and hNuMA-ir were observed. In addition, dense serotonin immunoreactive (5-HT-ir) fibers were observed around grafted SB623 cells and these fibers also appeared to be of the host origin. Also, in some SB623 grafted rats that were sacrificed within 2 h of dl-amphetamine injection, hot spots of c-Fos-positive nuclei that coincided with rejuvenated dense TH fibers around the grafted SB623 cells were observed, suggesting increased availability of DA in these locations. Our observations suggest that NICD-transfected MSC hold potential as a readily available autologous or allogenic cellular therapy for ameliorating the degeneration of DA and 5-HT neurons in PD patients.
Pig Pancreas Oxygenation at 20°C Increases Islet ATP Generation but Deteriorates Islet Function
Authors: Iken M. , Brandhorst H. , Korsgren O. , Brandhorst D.
Published: October 2009

Successful pancreas preservation during storage in oxygenated perfluorodecalin (PFD) is mainly related to oxidative ATP generation during storage. Increasing the storage temperature would accelerate this process essential for resuscitation of ischemically damaged pancreatic tissue. The present study aimed at comparing islet isolation outcome from adult pig pancreata preserved in oxygenated PFD by means of a one-layer method during storage on ice or at 20°C. Resected pancreata were intraductally flushed with cold UW solution and promptly processed ( n = 6) or stored for 3 h in continuously oxygenated PFD at 4°C ( n = 5) or 20°C ( n = 7). Prior to digestion-filtration pancreata were intraductally injected with UW supplemented with Serva collagenase NB8 and neutral protease. Islet quality assessment determined viability, glucose stimulation index, mitochondrial activity, intracellular ATP content, and transplant function in diabetic nude mice. Pancreata oxygenated for 3 h at 20°C yielded islet numbers similar to organs oxygenated at 4°C. Compared to a storage temperature of 20°C, preservation at 4°C reduced islet ATP content ( p < 0.05) as well as islet viability ( p < 0.05). Nevertheless, PFD storage at 20°C decreased insulin response to glucose compared to unstored pancreata ( p < 0.05). In contrast to unstored pancreata or cold-stored organs, transplantation of islets isolated after oxygenation at 20°C was characterized by an early loss of transplant function in 50% of recipients ( p < 0.05). The present study demonstrates that PFD storage at 20°C enhances islet ATP synthesis within a short period of oxygenation but deteriorates islet function. We conclude that the present data reflect an equilibration between reduced depression of metabolic activity resulting in damage of islets and temperature-stimulated acceleration of ATP synthesis. Future studies are required to adjust the optimum storage temperature for pancreas oxygenation in different species.
Gender-Dependent Survival of Allogeneic Trophoblast Stem Cells in Liver
Authors: Epple-Farmer Jessica , Debeb Bisrat G. , Smithies Oliver , Binas Bert
Published: October 2009

In view of the well-known phenomenon of trophoblast immune privilege, trophoblast stem cells (TSCs) might be expected to be immune privileged, which could be of interest for cell or gene therapies. Yet in the ectopic sites tested so far, TSC transplants fail to show noticeable immune privilege and seem to lack physiological support. However, we show here that after portal venous injection, green fluorescent protein (GFP)-labeled TSCs survive for several months in the livers of allogeneic female but not male mice. Gonadectomy experiments revealed that this survival does not require the presence of ovarian hormones but does require the absence of testicular factors. By contrast, GFP-labeled allogeneic embryonic stem cells (ESCs) are reliably rejected; however, these same ESCs survive when mixed with unlabeled TSCs. The protective effect does not require immunological compatibility between ESCs and TSCs. Tumors were not observed in animals with either successfully engrafted TSCs or coinjected ESCs. We conclude that in a suitable hormonal context and location, ectopic TSCs can exhibit and confer immune privilege. These findings suggest applications in cell and gene therapy as well as a new model for studying trophoblast immunology and physiology.