bluuebunny/crossref_metadata_2025 huggingface dataset:
Canola–Wheat Intercrops for Improved Agronomic Performance and Integrated Pest Management
Authors: Hummel Jeremy D. , Dosdall Lloyd M. , Clayton George W. , Turkington T. Kelly , Lupwayi Newton Z. , Harker K. Neil , O'Donovan John T.
Published: September 2009

Intercropping can enhance yields and reduce pest infestations, but investigations of intercropping regimes using crop species common to the large‐scale monoculture production systems of western Canada have not examined these diverse elements. Intercrops of canola (Brassica napus L.) and wheat (Triticum aestivum L.) were established at three sites in Alberta, Canada in 2005 and 2006 to determine interactions between intercropping regimes and crop grain and biomass yield, crop quality characteristics, soil microbial community biomass and diversity, flea beetles (Phyllotreta spp., Coleoptera: Chrysomelidae), and wheat leaf diseases. The study also investigated effects on flea beetles and soil microbial communities of a canola seed treatment containing a neonicotinoid insecticide and fungicides. Crop yields were comparable between intercrops and monocultures of canola and wheat. Crop quality characteristics and flea beetle feeding damage to canola seedlings had variable responses to intercropping. Flea beetle feeding was reduced with the inclusion of the seed treatment by between 1 and 20% damaged leaf area, although only one site‐year had damage levels great enough to overcome plant compensatory abilities in untreated plots. The first true‐leaf stage of canola development experienced the greatest flea beetle damage. Proportions of pathogen‐infected wheat leaf tissue were up to 2.5 times greater in intercrops than wheat monocultures but tended to decrease as the proportion of canola in the intercrops increased. Soil microbial parameters were unaffected by factors investigated. Although intercrop yields approximated those of monocultures, additional benefits of canola–wheat intercrops determined in this study appear insufficient to recommend this system for widespread adoption.
Maximizing Timothy Forage Yield and Quality by Balanced Nitrogen, Phosphorus, and Sulfur Fertilization
Authors: Malhi Sukhdev Singh , Coulman Bruce , Schoenau Jeffrey John
Published: September 2009

A 3‐yr (2005–2007) field experiment was conducted on a Gray Luvisol (Typic Cryoboralf) loam near Star City, SK, Canada, to determine the influence of single and combined annual applications of N, P, and S fertilizers on timothy (Phleum pratense L.) forage dry matter yield (DMY), quality [concentration of crude protein (CP), nitrate N, acid detergent fiber (ADF), neutral detergent fiber (NDF), total P, and total S] and N, P, and S uptake, and residual nitrate N, extractable P, and sulfate‐S in soil. The highest DMY and nutrient uptake were obtained when N and S were applied together. Concentration of CP and total P in forage increased with application of N alone, but decreased with the addition of S along with N. Concentrations of nitrate N in forage (< 0.011 g nitrate N kg−1) were much lower than those considered potentially toxic (>2.26 g nitrate N kg−1) to livestock. Concentration of ADF and NDF in forage increased with N application. Concentration of total S in forage increased with S application, but decreased with N application. Residual soil nitrate N in 0 to 60 cm depth increased with N application, but decreased when S was applied in combination with N. Residual soil extractable P in 0 to 15 cm depth increased with P fertilizer, but decreased when N and/or S were applied in combination with P. Residual soil sulfate‐S increased with S fertilization, but usually decreased when S was applied in combination with N. In conclusion, combined applications of N and S fertilizers produced maximum forage yield and nutrient uptake of timothy, and reduced accumulation of nitrate N in this soil lacking in these nutrients.
Impact of Varying Planting Dates and Tillage Systems on Cotton Growth and Lint Yield Production
Authors: Pettigrew William T. , Molin W. T. , Stetina S. R.
Published: September 2009

As economic conditions deteriorated, cotton (Gossypium hirsutum L.) producers have looked to improve profit margins by reducing inputs while maintaining yields. Pairing the yield benefits from early planting with the input reductions from conservation tillage might help accomplish those goals. The objective was to determine how growth, lint yield, and fiber quality were impacted by planting cotton early while using minimum tillage. Four cotton cultivars were planted either during the first week in April (Early) or the first week in May (Normal) in 2004 to 2007. Half the plots were conventional tillage and half were minimum tillage. Dry matter partitioning, flowering, root hydraulic conductance, leaf water potential, lint yield, yield components, and fiber quality data were collected. Cultivars differed in leaf water potential, leaf osmotic potential, and root hydraulic conductance. Root hydraulic conductance for the early planting was 21% greater than the normal planting, but no differences were detected between tillage treatments. Early planting increased yields 22% in 2007, but yields did not differ between planting dates any other year. During 2006 and 2007, lint yields were reduced 13% when minimum tillage was employed. No planting date × tillage treatment interactions were detected, so the same response to minimum tillage could be expected regardless of whether the planting occurred in early April or early May. Even though yield reductions were occasionally observed with minimum tillage, the pairing of minimum tillage with early planting could be a viable option for producers because of the input reduction.
Alternative Crop Rotations under Mediterranean No‐Tillage Conditions: Biomass, Grain Yield, and Water‐Use Efficiency
Authors: Álvaro‐Fuentes Jorge , Lampurlanés Jorge , Cantero‐Martínez Carlos
Published: September 2009

In Mediterranean semiarid areas, barley (Hordeum vulgare L.) and wheat (Triticum aestivum L.) are major crops because they are well adapted to limited‐water environments. In this study we tested the performance of alternative rotations to the typical barley and wheat monocultures in a rainfed Mediterranean semiarid area of northeastern Spain under a no‐tillage (NT) system. Four rotations were established and maintained over 6‐yr period (1999–2000 to 2004–2005): a wheat monoculture (W‐W‐W), a barley monoculture (B‐B‐B), a wheat‐barley‐rapeseed (Brassica napus L.) rotation (W‐B‐R), and a wheat‐barley‐vetch (Vicia sativa L.) rotation (W‐B‐V). Aboveground biomass, grain yield, water use (WU), and water use efficiency (WUE) were measured several times every season during the study period. All the parameters studied had a strong dependence on the rainfall variability found between growing seasons. Barley under rotation performed better than barley under monoculture in yield and WUE terms. However, wheat performed as well in a monoculture production system as it did in rotation. Rapeseed and vetch failed the 80 and 35% of the growing seasons, respectively. However, in semiarid Mediterranean agroecosystems of northeastern Spain, despite the beneficial rotation effect of theses alternative crops on barley performance, economical benefit of the overall rotation is doubtful since vetch failed in 2 out of 6 yr and rapeseed failed 5 out of 6 yr.
Yield and Breakeven Price of ‘Alamo’ Switchgrass for Biofuels in Tennessee
Authors: Mooney Daniel F. , Roberts Roland K. , English Burton C. , Tyler Donald D. , Larson James A.
Published: September 2009

Research on how land suitability affects yields and breakeven prices for switchgrass (Panicum virgatum L.) grown as a bioenergy crop is lacking for the U.S. Southeast. Data from a 3‐yr multilocation experiment at Milan, TN, were analyzed to determine the influence of soil drainage and landscape position on switchgrass yield and farm‐gate breakeven price. Plots were seeded in 2004 with ‘Alamo’ at 2.8, 5.6, 8.4, 11.2, and 14.0 kg ha−1 pure live seed (PLS). Plots were split in 2005 and N was applied at 0, 67, 134, and 201 kg N ha−1. Farm‐gate breakeven prices for 5‐ and 10‐yr production contracts were determined by calculating unit production costs from enterprise budgets that varied by input level and yield. Maximum yields occurred at 67 kg N ha−1 on well‐drained soils and at higher N levels on less‐well‐drained soils. Yield response to seeding rate (SR) was insignificant or small relative to other factors. Averaged across treatments, the well‐drained upland location suitable for row crops had the largest yield (17.7 Mg ha−1) and lowest breakeven price ($46 Mg−1) for a 10‐yr period. In contrast, the poorly drained flood plain location considered marginal yielded lowest (8.5 Mg ha−1) and had the highest breakeven price ($69 Mg−1). Breakeven prices were sensitive to yield, N price, and fuel price. Results suggest a lower breakeven price for switchgrass in the U.S. Southeast as compared with other U.S. regions, mainly due to high yields for the Alamo variety.
Nitrogen Fertilization Effect on Phosphorus Remediation Potential of Three Perennial Warm‐Season Forages
Authors: Newman Y. C. , Agyin‐Birikorang S. , Adjei M. B. , Scholberg J. M. , Silveira M. L. , Vendramini J. M. B. , Rechcigl J. E. , Sollenberger L. E.
Published: September 2009

Warm‐season C4 grasses are capable of removing excess soil nutrients because of their high yield potential and nutrient uptake efficiency. Bahiagrass (Paspalum notatum Flügge), limpograss [Hemarthria altissima (Poir.) Stapf & Hubb], and stargrass (Cynodon nlemfuensis Vanderyst), three commonly used pasture grasses in South‐Central Florida, were grown to examine the effect of increasing N rates on herbage production and soil P removal. Nitrogen was applied at rates of 67, 90, and 134 kg N ha−1 harvest−1, representing 1, 1.3, and 2 times the recommended N fertilizer application rate for hay production. During 3 yr of evaluation, all three grasses showed a positive P‐removal potential that increased with increasing N fertilizer application. Phosphorus removed by forages over the 3‐yr period for the highest N application rate was 106, 132, and 147 kg ha−1 for limpograss, bahiagrass, and stargrass, respectively. Mehlich 1 extractable P from the Ap horizon of all plots decreased by as much as 80% of the initial P load over the study period; only ∼15 to 17% of which appeared to leach to subsurface horizons. Nitrogen application enhanced P uptake and consequently reduced P transport to deep (>13 cm) soil depths. These data indicate that stargrass, bahiagrass, and limpograss managed intensively for hay production represent effective options in removing excess soil P from P‐impacted sites.
Living Mulch Forage Yield and Botanical Composition in a Corn‐Soybean‐Forage Rotation
Authors: Singer Jeremy W. , Kohler Keith A. , Moore Kenneth J. , Meek David W.
Published: September 2009

Managing forages as living mulches during row crop production requires suppressing the forages to produce economical crop yields. The objective of this research was to identify forage plants with varied growth habit, persistence, and yield potential to provide desirable ecosystem functions in a multifunctional cropping system. Alfalfa (Medicago sativa L.), kura clover (Trifolium ambiguum Bieb.), and birdsfoot trefoil (Lotus corniculatus L.) were evaluated in sole seedings, binary mixtures, and reed canarygrass (Phalaris arundinacea L.) and orchardgrass (Dactylis glomerata L.) were included in three‐way mixtures in a corn (Zea mays L.)–soybean [Glycine max (L.) Merr.]–forage rotation. The forages functioned as cover crops in corn and soybean and were suppressed using a 25‐cm glyphosate band over the row. In the forage year, treatments containing alfalfa produced the highest yields (7824 kg ha−1 average dry matter 2005–2007). Three‐way mixtures provided greater weed suppression in the interrow than sole seedings or binary mixtures in 2 of 3 yr (80 vs. 127 weeds m−2, 2005–2006 average). Kura clover provided greater weed suppression than alfalfa in the former row (108 vs. 186 weeds m−2). Reed canarygrass exhibited better stability in sward composition (20% in 2005 and 22% in 2007) than orchardgrass (58% in 2005 and 16% in 2007). Consequently, the best combination of species to use as living mulches to provide high forage yields and lower weed densities includes alfalfa, kura clover, and reed canarygrass. Seeding a nondormant alfalfa in the spring of the forage year will supplement yield and suppress weeds in the former crop row.
A Comparison of Regional Variations of Fertility in Bangladesh
Authors: Kabir Ahmad , Ali Rahmat , Islam M. Shahidul , Kawsar L. A. , Islam M. A.
Published: September 2009

This study, based on the 2004 Bangladesh Demographic and Health Survey (BDHS), examines the extent to which regional variations of reproductive behavior are explained by inherent demographic, socioeconomic, and programmatic differences among regions. This article also attempts to investigate the impact of four intermediate fertility variables; namely marriage, contraception, lactational infecundability, and induced abortion, on fertility among different regions in Bangladesh. The contribution of proximate variables was observed through the decomposition of the total fertility rate (TFR) into proximate components. The results indicate that contraception is the highest fertility reducing factor in all the regions.
The psychological contract of the temporary employee in the public sector in Taiwan
Authors: Chang Cheng-Ping , Hsu Po-Chiun
Published: September 2009

In this study an interview method was used to investigate the psychological contracts of temporary employees in the Administration Bureau of South Taiwan Science Park. The conclusions offer suggestions about management practices and improvement of the welfare of workers. These suggestions
can be used by government agencies that allocate temporary labor and by related departments that hire temporary employees.
Development and validation of the Dichotomous Thinking Inventory
Authors: Oshio Atsushi
Published: September 2009

The Dichotomous Thinking Inventory (DTI) was developed for this study as a self-report measure used to assess a black-and-white cognitive thinking style or worldview. Validation of the DTI was explored with regard to the relationships among dichotomous thinking, borderline personality,
narcissism, self-esteem, undervaluing others, intolerance for ambiguity, perfectionism, and the Big Five; and relationships between dichotomous thinking and peer ratings of traits and attitudes. Factor analysis of the DTI revealed 3 components: preference for dichotomy, dichotomous beliefs,
and profit-and-loss thinking. Internal consistency and test-retest reliability of the DTI were at a sufficient level. Correlations among self-measures supported the convergent and discriminant validity of the DTI. Participants who scored highly on the DTI were rated as being articulate and
straightforward by their friends. These results generally supported the reliability and validity of the DTI.
The validity and reliability of the revised Chinese version of the Situational Self-Awareness Scale
Authors: Liu Xu-Feng , Shao Yong-Cong , Yang Ye-Bing , Wu Sheng-Jun , Yang Hai , Wang Wei , Xiao Wei
Published: September 2009

In this study a Chinese version of the Situational Self-Awareness Scale (SSAS; Govern & Marsch, 2001) was developed and tested for validity and reliability. Participants were 1,244 undergraduate students. Exploratory and confirmatory factor analysis and other statistical methods
yielded results indicating a good correlation of items in the Chinese (C-SSAS) and English version of the scale. When private self-awareness was assessed in a private setting the score of participants was significantly greater and likewise the public self-awareness scores were higher when
the scale was completed in a public setting. Test-retest reliability was significant across situations and time. The reallocation of one item to public self-awareness in the C-SSAS from private in the SSAS was indicative of differences between Eastern and Western cultures and this is discussed.
In general, the results indicated that the Chinese version of the SSAS has good reliability and validity. The scale should, therefore, be suitable as a reference to develop scales for evaluating personnel working in specific occupations.
Coping with stress and trait anxiety in terms of locus of control: A study with Turkish university students
Authors: Arslan Coşkun , Dilmaç Bülent , Hamarta Erdal
Published: September 2009

The purpose of this study was to determine whether trait anxiety and coping with stress vary significantly according to locus of control. The study was carried out with 514 (286 female and 228 male) Turkish university students, aged between 18 and 27. It was found that average trait
anxiety scores of the students with internal locus of control were significantly lower than those of the students with external locus of control and that average problem-focused coping with stress scores of the students with internal locus of control were significantly higher than those of
the students with external locus of control. There was no significant difference in incidence of avoidance and seeking social support between the students with internal locus of control and those students with external locus of control.
The influence of concealing academic achievement on the self-esteem of adolescents with low achievement
Authors: Zhang Baoshan , Zhao Jun-Yan , Yu Guoliang
Published: September 2009

An examination was carried out of the influences of concealing academic achievement on self-esteem in an academically relevant social interaction based on the assumption that concealing socially devalued characteristics should influence individuals' self-esteem during social interactions.
An interview paradigm called for school-aged adolescents who either were or were not low (academic) achievers to play the role of students who were or were not low achievers while answering academically relevant questions. The data suggest that the performance self-esteem of low achievers
who played the role of good students was more positive than that of low achievers who played the role of low achievers. On the other hand, participants who played the role of good students had more positive performance self-esteem than did participants who played the role of low achievers.
Evaluation of the factors affecting loneliness and hopelessness among university students in Turkey
Authors: Girgin Günseli
Published: September 2009

The aim of this study was to determine the factors affecting loneliness and hopelessness among university students in Turkey. Data were collected with the UCLA Loneliness Scale (Russell, Peplau, & Cutrona, 1980), the Beck Hopelessness Inventory (Beck, Weissman, Lester, & Trexler,
1971), and a questionnaire developed by the researcher. One hundred and ninety-six people took part in the study. Results showed that the male participants suffered from loneliness and hopelessness more frequently. They liked the university environment, but the limited number of friends and
parental attitudes contributed considerably to hopelessness. In addition, there was a strong correlation between the severity of loneliness and the severity of hopelessness.
An integrated process model of communication satisfaction and organizational outcomes
Authors: Tsai Ming-Ten , Chuang Shuang-Shii , Hsieh Wei-Ping
Published: September 2009

The relationship of communication satisfaction to job performance and turnover intention among employees was examined. Most communication satisfaction research has been conducted in relation to job satisfaction. However, there is a growing interest in the relationships between communication
satisfaction, job performance, and turnover intention. The population examined in this study were employed in the top 500 service industries in Taiwan. The sample consisted of 1,260 individuals. A total of 467 valid responses were collected for a usable response rate of 37.1%. The results
suggest that employees' perceptions of a high communication satisfaction are positively associated with their job performance, and negatively related to turnover intention.
The relationship between attachment styles and social anxiety: An investigation with Turkish university students
Authors: Erozkan Atilgan
Published: September 2009

This study was aimed at investigating the relationship between attachment styles and social anxiety. The sample consisted of 600 (300 female, 300 male) university students. Attachment styles and social anxiety levels of university students were measured using the Relationship Scales
Questionnaire (Griffin & Bartholomew, 1994), and Social Anxiety Scale (Ozbay & Palanci, 2001), respectively. Multiple regression analysis and correlation analysis were employed to analyze data. Attachment styles were found to be significantly correlated with social anxiety.
The moderating role of seeking social support on coping styles and perceptions of organizational justice: A study with French and Turkish students
Authors: Finkelstein Rémi , Minibas-Poussard Jale , Bastounis Marina
Published: September 2009

We examined the relationship between perceived organizational justice and coping styles in a cross-cultural comparison. Data were collected from university students in Paris, France (individualist culture; N = 192, age M = 21.6) and Istanbul, Turkey (collectivist culture;
N = 251, age M = 22). The questionnaire (adapted from Colquitt, 2001) included ratings of distributive, procedural, and interactional justice at the university, and a coping style inventory (Vitaliano, Russo, Carr, Maiuro, & Becker, 1985) measuring preference for problem-focused
coping, emotion-focused coping and seeking social support. In the Turkish data social-support seeking was higher than in the French sample and it was positively correlated with justice perceptions. When seeking social support was linked to problem-focused coping, it was also linked to a more
positive evaluation of justice in the Turkish, but not the French data.
The Effects of Expected and Actual Accounting Choices on Judgments and Decisions
Authors: Clor-Proell Shana M.
Published: September 2009

ABSTRACT: This research investigates how financial statement users' judgments and decisions are affected by the extent to which a firm's actual accounting choices match users' expectations. Based on prior communications research, I predict and find that users' credibility judgments are more extreme when a firm's actual accounting choices do not match expectations. Experiment 1 supports this prediction in a stock-based compensation context, and Experiment 2 supports it in an accounting estimate context. Further, evidence from Experiment 1 supports the prediction that credibility judgments mediate the effect of a mismatch on investment decisions. Finally, evidence from Experiment 2 partially supports the prediction that users who encounter a mismatch between actual and expected accounting choices are more likely to search for additional information than are users who encounter a match. The results have implications for accounting researchers, regulators, and managers interested in understanding how firms' accounting choices affect users' decisions.
Stealth Disclosure of Accounting Restatements
Authors: Files Rebecca , Swanson Edward P. , Tse Senyo
Published: September 2009

ABSTRACT: Managers exercise considerable discretion over how they announce an accounting restatement in a press release. Some firms issue a press release that discloses the restatement in the headline (high prominence). Others provide a press release with a headline on a different subject (for example, earnings news) but describe the restatement in the body of the release (medium prominence). The remaining firms discuss the restatement at the end of the press release in a footnote to operating results (low prominence). Mean three-day returns differ considerably across these three categories of prominence (−8.3, −4.0, and −1.5 percent, respectively). We find that disclosure prominence is significantly negatively associated with returns in a model that controls for the seriousness of the GAAP violation, restatement magnitude, other restatement characteristics, and potential endogeneity. Similarly, we find the likelihood of class action lawsuits is significantly reduced with less prominent disclosure.
Management Forecasts in Japan: An Empirical Study of Forecasts that Are Effectively Mandated
Authors: Kato Kazuo , Skinner Douglas J. , Kunimura Michio
Published: September 2009

ABSTRACT: We study management forecasts in Japan, where forecasts are effectively mandated but managers have considerable latitude over the numbers they release. We find that managers' initial earnings forecasts for a fiscal year are systematically upward-biased but that they revise their forecasts downward during the fiscal year so that most earnings surprises are non-negative. Managers' initial forecast optimism is inversely related to firm performance, and is more pronounced for firms with higher levels of insider ownership, smaller firms, and firms with a history of forecast optimism. The fact that managers' forecasts tend to be consistently optimistic suggests that reputation effects are insufficient to ensure managerial forecast accuracy. We also find that the information content of managers' forecasts is related to proxies for whether market participants view the forecasts as credible.
Chemerin Is a Novel Adipocyte-Derived Factor Inducing Insulin Resistance in Primary Human Skeletal Muscle Cells
Authors: Sell Henrike , Laurencikiene Jurga , Taube Annika , Eckardt Kristin , Cramer Andrea , Horrighs Angelika , Arner Peter , Eckel Jürgen
Published: September 2009

OBJECTIVE

Chemerin is an adipokine that affects adipogenesis and glucose homeostasis in adipocytes and increases with BMI in humans. This study was aimed at investigating the regulation of chemerin release and its effects on glucose metabolism in skeletal muscle cells.

RESEARCH DESIGN AND METHODS

Human skeletal muscle cells were treated with chemerin to study insulin signaling, glucose uptake, and activation of stress kinases. The release of chemerin was analyzed from in vitro differentiated human adipocytes and adipose tissue explants from 27 lean and 26 obese patients.

RESULTS

Human adipocytes express chemerin and chemokine-like receptor 1 (CMKLR1) differentiation dependently and secrete chemerin (15 ng/ml from 106 cells). This process is slightly but significantly increased by tumor necrosis factor-α and markedly inhibited by >80% by peroxisome proliferator–activated receptor-γ activation. Adipose tissue explants from obese patients are characterized by significantly higher chemerin secretion compared with lean control subjects (21 and 8 ng from 107 cells, respectively). Chemerin release is correlated with BMI, waist-to-hip ratio, and adipocyte volume. Furthermore, higher chemerin release is associated with insulin resistance at the level of lipogenesis and insulin-induced antilipolysis in adipocytes. Chemerin induces insulin resistance in human skeletal muscle cells at the level of insulin receptor substrate 1, Akt and glycogen synthase kinase 3 phosphorylation, and glucose uptake. Furthermore, chemerin activates p38 mitogen-activated protein kinase, nuclear factor-κB, and extracellular signal–regulated kinase (ERK)-1/2. Inhibition of ERK prevents chemerin-induced insulin resistance, pointing to participation of this pathway in chemerin action.

CONCLUSIONS

Adipocyte-derived secretion of chemerin may be involved in the negative cross talk between adipose tissue and skeletal muscle contributing to the negative relationship between obesity and insulin sensitivity.
Impact of 9 Days of Bed Rest on Hepatic and Peripheral Insulin Action, Insulin Secretion, and Whole-Body Lipolysis in Healthy Young Male Offspring of Patients With Type 2 Diabetes
Authors: Alibegovic Amra C. , Højbjerre Lise , Sonne Mette P. , van Hall Gerrit , Stallknecht Bente , Dela Flemming , Vaag Allan
Published: September 2009

OBJECTIVE

The aim of this study was to investigate the impact of 9 days of bed rest on insulin secretion, insulin action, and whole-body glucose and fat metabolism in first-degree relative (FDR) and matched control (CON) subjects.

RESEARCH DESIGN AND METHODS

A total of 13 FDR and 20 CON subjects participated in the study. All were studied before and after 9 days of bed rest using the clamp technique combined with indirect calorimetry preceded by an intravenous glucose tolerance test. Glucose and glycerol turnover rates were studied using stable isotope kinetics.

RESULTS

Bed rest caused a significant decrease in whole-body insulin sensitivity in both groups. Hepatic insulin resistance was elevated in FDR subjects prior to bed rest and was significantly augmented by bed rest in FDR (P < 0.01) but not in CON (P = NS) subjects. The rate of whole-body lipolysis decreased during bed rest in both FDR and CON subjects, with no significant differences between the groups. Insulin resistance induced by bed rest was fully accounted for by the impairment of nonoxidative glucose metabolism in both groups (overall P < 0.001).

CONCLUSIONS

Whole-body insulin action in both insulin-resistant FDR and healthy CON subjects deteriorates with 9 days of bed rest, converging toward similar degrees of whole-body insulin resistance. FDR subjects exhibit hepatic insulin resistance (HIR), which, in contrast to CON subjects, deteriorates in response to physical inactivity. FDR subjects exhibit reduced insulin secretion when seen in relation to their degree of HIR but not peripheral insulin resistance.
Virus-Induced Autoimmune Diabetes in the LEW.1WR1 Rat Requires Iddm14 and a Genetic Locus Proximal to the Major Histocompatibility Complex
Authors: Blankenhorn Elizabeth P. , Cort Laura , Greiner Dale L. , Guberski Dennis L. , Mordes John P.
Published: September 2009

OBJECTIVE

To identify genes that confer susceptibility to autoimmune diabetes following viral infection in the LEW.1WR1 rat.

RESEARCH DESIGN AND METHODS

About 2% of LEW.1WR1 rats develop spontaneous autoimmune diabetes. Immunological perturbants including viral infection increase both the frequency and tempo of diabetes onset. To identify diabetes susceptibility genes (LEW.1WR1 × WF), F2 rats were infected with Kilham rat virus following brief pretreatment with polyinosinic:polycytidylic acid. This treatment induces diabetes in 100% of parental LEW.1WR1 rats and 0% of parental WF rats. Linkage to diabetes was analyzed by genome-wide scanning.

RESULTS

Among 182 F2 rats, 57 (31%) developed autoimmune diabetes after a mean latency of 16 days. All diabetic animals and ∼20% of nondiabetic animals exhibited pancreatic insulitis. Genome-wide scanning revealed a requirement for the Iddm14 locus, long known to be required for diabetes in the BB rat. In addition, a new locus near the RT1 major histocompatibility complex (MHC) was found to be a major determinant of disease susceptibility. Interestingly, one gene linked to autoimmune diabetes in mouse and human, UBD, lies within this region.

CONCLUSIONS

The Iddm14 diabetes locus in the rat is a powerful determinant of disease penetrance in the LEW.1WR1 rat following viral infection. In addition, a locus near the MHC (Iddm37) conditions diabetes susceptibility in these animals. Other, as-yet-unidentified genes are required to convert latent susceptibility to overt diabetes. These data provide insight into the polygenic nature of autoimmune diabetes in the rat and the interplay of genetic and environmental factors underlying disease expression.
Impact of the PPAR-γ2 Pro12Ala Polymorphism and ACE Inhibitor Therapy on New-Onset Microalbuminuria in Type 2 Diabetes: Evidence From BENEDICT
Authors: De Cosmo Salvatore , Motterlini Nicola , Prudente Sabrina , Pellegrini Fabio , Trevisan Roberto , Bossi Antonio , Remuzzi Giuseppe , Trischitta Vincenzo , Ruggenenti Piero ,   on behalf of the BENEDICT Study Group
Published: September 2009

OBJECTIVE

Cross-sectional studies found less microalbuminuria in type 2 diabetic patients with the Ala12 allele of the peroxisome proliferator–activated receptor-γ2 (PPAR-γ2) Pro12Ala polymorphism. We prospectively evaluated the association between Pro12Ala polymorphism (rs1801282) and new-onset microalbuminuria.

RESEARCH DESIGN AND METHODS

Pro12Ala polymorphism was genotyped by TaqMan-based assay in genomic DNA of 1,119 consenting patients from BErgamo NEphrologic DIabetic Complications Trial (BENEDICT)—a prospective, randomized trial evaluating ACE inhibition effect on new-onset microalbuminuria (albuminuria 20–200 μg/min in at least two of three consecutive overnight urine collections in two consecutive visits) in hypertensive type 2 diabetes with albuminuria <20 μg/min at inclusion.

RESULTS

Baseline characteristics of Ala (Ala/Ala or Ala/Pro) carriers and Pro/Pro homozygotes were similar, with a nonsignificant trend to lower albuminuria (P = 0.1107) in the 177 Ala carriers. Over a median (interquartile range) of 44.0 (17.1–51.9) months, 7 (4%) Ala carriers and 86 (9.1%) Pro/Pro homozygotes developed microalbuminuria (hazard ratio [HR] 0.45 [95% CI 0.21–0.97]; P = 0.042). Final albuminuria was significantly lower in Ala carriers than Pro/Pro homozygotes (7.3 ± 9.1 vs. 10.5 ± 24.9 μg/min, respectively), even after adjustment for baseline albuminuria (P = 0.048). Baseline and follow-up blood pressure and metabolic control were similar in both groups. Incidence of microalbuminuria was significantly decreased by ACE versus non-ACE inhibitor therapy in Pro/Pro homozygotes (6.3 vs. 11.9%, respectively, HR 0.46 [0.29–0.72]; P < 0.001).

CONCLUSIONS

In type 2 diabetes, the Ala allele protects from worsening albuminuria and new-onset microalbuminuria, and ACE inhibition blunts the excess risk of microalbuminuria associated with the Pro/Pro genotype. Evaluating Pro12Ala polymorphism may help identifying patients at risk who may benefit the most from early renoprotective therapy.
Fibroblast Growth Factor-21 Is Induced in Human Skeletal Muscles by Hyperinsulinemia
Authors: Hojman Pernille , Pedersen Maria , Nielsen Anders Rinnov , Krogh-Madsen Rikke , Yfanti Christina , Åkerstrom Thorbjørn , Nielsen Søren , Pedersen Bente Klarlund
Published: September 2009

OBJECTIVE

Fibroblast growth factor-21 (FGF-21) is a potent metabolic regulator, which in animal models has been shown to improve glucose metabolism and insulin sensitivity. Recently, FGF-21 was shown to be expressed and secreted from murine muscle cells in response to insulin stimulation.

RESEARCH DESIGN AND METHODS

We studied muscular FGF-21 expression and plasma FGF-21 after acute insulin stimulation in young healthy men during a hyperinsulinemic- euglycemic clamp. Furthermore, we investigated systemic levels and muscle FGF-21 expression in humans with or without insulin resistance and chronic elevated insulin.

RESULTS

FGF-21 was barely detectable in young healthy men before insulin infusion. After 3 or 4 h of insulin infusion during a hyperinsulinemic-euglycemic clamp, muscular FGF-21 expression increased significantly. Plasma FGF-21 followed the same pattern. In individuals with chronic elevated insulin, muscular FGF-21 expression was associated with hyperinsulinemia in men but not in women. In plasma, hyperinsulinemia and fasting glucose were positively associated with plasma FGF-21 while plasma FGF-21 correlated negatively with HDL cholesterol. No associations between muscle and plasma FGF-21 were found in the individuals with chronic hyperinsulinemia.

CONCLUSIONS

FGF-21 is expressed in human skeletal muscle in response to insulin stimulation, suggesting that FGF-21 is an insulin-regulated myokine. In support, we found an association between chronic hyperinsulinemia and levels of FGF-21.
Functional Role of Neuroendocrine-Specific Protein-Like 1 in Membrane Translocation of GLUT4
Authors: Ikemoto Takaaki , Hosoya Takamitsu , Takata Kumi , Aoyama Hiroshi , Hiramatsu Toshiyuki , Onoe Hirotaka , Suzuki Masaaki , Endo Makoto
Published: September 2009

OBJECTIVE

In skeletal muscles, dantrolene inhibits the exercise-induced membrane translocation of GLUT4. It has been postulated that the inhibitory action of dantrolene on Ca2+ release from the sarcoplasmic reticulum (SR) causes inhibition of exercise-induced glucose uptake; however, the precise mechanism has not been adequately studied.

RESEARCH DESIGN AND METHODS

We discovered that dantrolene can bind to skeletal-type neuroendocrine-specific protein-like 1 (sk-NSPl1) with photoreactive dantrolene derivatives. In sk-NSPl1–deficient muscles, we examined the change in glucose uptake and the membrane translocation of GLUT4. In addition, we examined the change in blood glucose and also measured the glycogen level in both isolated and in situ skeletal muscles after electrical stimulation using our mutant mouse.

RESULTS

In sk-NSPl1–deficient muscles, exercise-induced glucose uptake was totally abolished with no change in insulin-induced glucose uptake. The Ca2+ release mechanism and its inhibition by dantrolene were completely preserved in these muscles. The expression of GLUT4 in the mutant muscles also appeared unchanged. Confocal imaging and results using the membrane isolation method showed that exercise/contraction did not enhance GLUT4 translocation in these sk-NSPl1–deficient muscles under conditions of adequate muscle glycogen consumption. The blood glucose level in normal mice was reduced by electrical stimulation of the hind limbs, but that in mutant mice was unchanged.

CONCLUSIONS

sk-NSPl1 is a novel dantrolene receptor that plays an important role in membrane translocation of GLUT4 induced by contraction/exercise. The 23-kDa sk-NSPl1 may also be involved in the regulation of glucose levels in the whole body.
Enhancement of Muscle Mitochondrial Oxidative Capacity and Alterations in Insulin Action Are Lipid Species Dependent
Authors: Turner Nigel , Hariharan Krit , TidAng Jennifer , Frangioudakis Georgia , Beale Susan M. , Wright Lauren E. , Zeng Xiao Yi , Leslie Simon J. , Li Jing-Ya , Kraegen Edward W. , Cooney Gregory J. , Ye Ji-Ming
Published: September 2009

OBJECTIVE

Medium-chain fatty acids (MCFAs) have been reported to be less obesogenic than long-chain fatty acids (LCFAs); however, relatively little is known regarding their effect on insulin action. Here, we examined the tissue-specific effects of MCFAs on lipid metabolism and insulin action.

RESEARCH DESIGN AND METHODS

C57BL6/J mice and Wistar rats were fed either a low-fat control diet or high-fat diets rich in MCFAs or LCFAs for 4–5 weeks, and markers of mitochondrial oxidative capacity, lipid levels, and insulin action were measured.

RESULTS

Mice fed the MCFA diet displayed reduced adiposity and better glucose tolerance than LCFA-fed animals. In skeletal muscle, triglyceride levels were increased by the LCFA diet (77%, P < 0.01) but remained at low-fat diet control levels in the MCFA-fed animals. The LCFA diet increased (20–50%, P < 0.05) markers of mitochondrial metabolism in muscle compared with low-fat diet–fed controls; however; the increase in oxidative capacity was substantially greater in MCFA-fed animals (50–140% versus low-fat–fed controls, P < 0.01). The MCFA diet induced a greater accumulation of liver triglycerides than the LCFA diet, likely due to an upregulation of several lipogenic enzymes. In rats, isocaloric feeding of MCFA or LCFA high-fat diets induced hepatic insulin resistance to a similar degree; however, insulin action was preserved at the level of low-fat diet–fed controls in muscle and adipose from MCFA-fed animals.

CONCLUSIONS

MCFAs reduce adiposity and preserve insulin action in muscle and adipose, despite inducing steatosis and insulin resistance in the liver. Dietary supplementation with MCFAs may therefore be beneficial for preventing obesity and peripheral insulin resistance.
Severe Insulin Resistance and Intrauterine Growth Deficiency Associated With Haploinsufficiency for INSR and CHN2
Authors: Suliman Sara G.I. , Stanik Juraj , McCulloch Laura J. , Wilson Natalie , Edghill Emma L. , Misovicova Nadezda , Gasperikova Daniela , Sandrikova Vilja , Elliott Katherine S. , Barak Lubomir , Ellard Sian , Volpi Emanuela V. , Klimes Iwar , Gloyn Anna L.
Published: September 2009

OBJECTIVE

Digenic causes of human disease are rarely reported. Insulin via its receptor, which is encoded by INSR, plays a key role in both metabolic and growth signaling pathways. Heterozygous INSR mutations are the most common cause of monogenic insulin resistance. However, growth retardation is only reported with homozygous or compound heterozygous mutations. We describe a novel translocation [t(7,19)(p15.2;p13.2)] cosegregating with insulin resistance and pre- and postnatal growth deficiency. Chromosome translocations present a unique opportunity to identify modifying loci; therefore, our objective was to determine the mutational mechanism resulting in this complex phenotype.

RESEARCH DESIGN AND METHODS

Breakpoint mapping was performed by fluorescence in situ hybridization (FISH) on patient chromosomes. Sequencing and gene expression studies of disrupted and adjacent genes were performed on patient-derived tissues.

RESULTS

Affected individuals had increased insulin, C-peptide, insulin–to–C-peptide ratio, and adiponectin levels consistent with an insulin receptoropathy. FISH mapping established that the translocation breakpoints disrupt INSR on chromosome 19p15.2 and CHN2 on chromosome 7p13.2. Sequencing demonstrated INSR haploinsufficiency accounting for elevated insulin levels and dysglycemia. CHN2 encoding β-2 chimerin was shown to be expressed in insulin-sensitive tissues, and its disruption was shown to result in decreased gene expression in patient-derived adipose tissue.

CONCLUSIONS

We present a likely digenic cause of insulin resistance and growth deficiency resulting from the combined heterozygous disruption of INSR and CHN2, implicating CHN2 for the first time as a key element of proximal insulin signaling in vivo.
Prenatal Programming of Metabolic Syndrome in the Common Marmoset Is Associated With Increased Expression of 11β-Hydroxysteroid Dehydrogenase Type 1
Authors: Nyirenda Moffat J. , Carter Roderick , Tang Justin I. , de Vries Annick , Schlumbohm Christina , Hillier Stephen G. , Streit Frank , Oellerich Michael , Armstrong Victor W. , Fuchs Eberhard , Seckl Jonathan R.
Published: September 2009

OBJECTIVE

Recent studies in humans and animal models of obesity have shown increased adipose tissue activity of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), which amplifies local tissue glucocorticoid concentrations. The reasons for this 11β-HSD1 dysregulation are unknown. Here, we tested whether 11β-HSD1 expression, like the metabolic syndrome, is “programmed” by prenatal environmental events in a nonhuman primate model, the common marmoset monkey.

RESEARCH DESIGN AND METHODS

We used a “fetal programming” paradigm where brief antenatal exposure to glucocorticoids leads to the metabolic syndrome in the offspring. Pregnant marmosets were given the synthetic glucocorticoid dexamethasone orally for 1 week in either early or late gestation, or they were given vehicle. Tissue 11β-HSD1 and glucocorticoid receptor mRNA expression were examined in the offspring at 4 and 24 months of age.

RESULTS

Prenatal dexamethasone administration, selectively during late gestation, resulted in early and persistent elevations in 11β-HSD1 mRNA expression and activity in the liver, pancreas, and subcutaneous—but not visceral—fat. The increase in 11β-HSD1 occurred before animals developed obesity or overt features of the metabolic syndrome. In contrast to rodents, in utero dexamethasone exposure did not alter glucocorticoid receptor expression in metabolic tissues in marmosets.

CONCLUSIONS

These data suggest that long-term upregulation of 11β-HSD1 in metabolically active tissues may follow prenatal “stress” hormone exposure and indicates a novel mechanism for fetal origins of adult obesity and the metabolic syndrome.
Use of Multiple Metabolic and Genetic Markers to Improve the Prediction of Type 2 Diabetes: the EPIC-Potsdam Study
Authors: Schulze Matthias B. , Weikert Cornelia , Pischon Tobias , Bergmann Manuela M. , Al-Hasani Hadi , Schleicher Erwin , Fritsche Andreas , Häring Hans-Ulrich , Boeing Heiner , Joost Hans-Georg
Published: September 2009

OBJECTIVE

We investigated whether metabolic biomarkers and single nucleotide polymorphisms (SNPs) improve diabetes prediction beyond age, anthropometry, and lifestyle risk factors.

RESEARCH DESIGN AND METHODS

A case-cohort study within a prospective study was designed. We randomly selected a subcohort (n = 2,500) from 26,444 participants, of whom 1,962 were diabetes free at baseline. Of the 801 incident type 2 diabetes cases identified in the cohort during 7 years of follow-up, 579 remained for analyses after exclusions. Prediction models were compared by receiver operatoring characteristic (ROC) curve and integrated discrimination improvement.

RESULTS

Case-control discrimination by the lifestyle characteristics (ROC-AUC: 0.8465) improved with plasma glucose (ROC-AUC: 0.8672, P < 0.001) and A1C (ROC-AUC: 0.8859, P < 0.001). ROC-AUC further improved with HDL cholesterol, triglycerides, γ-glutamyltransferase, and alanine aminotransferase (0.9000, P = 0.002). Twenty SNPs did not improve discrimination beyond these characteristics (P = 0.69).

CONCLUSIONS

Metabolic markers, but not genotyping for 20 diabetogenic SNPs, improve discrimination of incident type 2 diabetes beyond lifestyle risk factors.
Exploration of the Relationship Between Household Food Insecurity and Diabetes in Canada
Authors: Gucciardi Enza , Vogt Janet A. , DeMelo Margaret , Stewart Donna E.
Published: September 2009

OBJECTIVE

To determine the household food insecurity (HFI) prevalence in Canadians with diabetes and its relationship with diabetes management, self-care practices, and health status.

RESEARCH DESIGN AND METHODS

We analyzed data from Canadians with diabetes aged ≥12 years (n = 6,237) from cycle 3.1 of the Canadian Community Health Survey, a population-based cross-sectional survey conducted in 2005. The HFI prevalence in Canadians with diabetes was compared with that in those without diabetes. The relationships between HFI and management services, self-care practices, and health status were examined for Ontarians with diabetes (n = 2,523).

RESULTS

HFI was more prevalent among individuals with diabetes (9.3% [8.2–10.4]) than among those without diabetes (6.8% [6.5–7.0]) and was not associated with diabetes management services but was associated with physical inactivity (odds ratio 1.54 [95% CI 1.10–2.17]), lower fruit and vegetable consumption (0.52 [0.33–0.81]), current smoking (1.71 [1.09–2.69]), unmet health care needs (2.71 [1.74–4.23]), having been an overnight patient (2.08 [1.43–3.04]), having a mood disorder (2.18 [1.54–3.08]), having effects from a stroke (2.39 [1.32–4.32]), lower satisfaction with life (0.28 [0.18–0.43]), self-rated general (0.37 [0.21–0.66]) and mental (0.17 [0.10–0.29]) health, and higher self-perceived stress (2.04 [1.30–3.20]). The odds of HFI were higher for an individual in whom diabetes was diagnosed at age <40 years (3.08 [1.96–4.84]).

CONCLUSIONS

HFI prevalence is higher among Canadians with diabetes and is associated with an increased likelihood of unhealthy behaviors, psychological distress, and poorer physical health.
Test Methods for Hyperelastic Characterization of Rubber
Authors: Kupchella R. , Kidney J. , Hutchison W.
Published: September 2009

Optical methods using digital image correlation (DIC) are utilized in developing rubber constitutive tests. Two and three dimensional DIC systems are employed to measure strains on rubber specimens subjected to uniaxial, planar, and biaxial stress states. A special membrane inflation test was developed and is described for providing the biaxial constitutive data. Deformation-induced material property changes for the three modes of testing are quantified using a concept based on energy dissipation. The constitutive test strain ranges for each of the three modes are separately selected to equalize the material states. The methodology is applied to filled rubber compounds in order to characterize them in terms of hyperelastic behavior. Evaluation and comparison of several common hyperelastic models are given, and application to finite element modeling of a structural rubber specimen is described.