Effect of enhanced ammonium nutrition on grain yield, yield components and plant adaptation of maize grown in soybean-corn and corn-corn rotations

Hydroponic studies on maize (Zea mays L.) have shown productivity to be greater when maize was supplied with mixed nitrogen, however, the benefits of mixed N nutrition under field conditions have been difficult to evaluate. This study was initiated to: (i) determine the effect of rate of point injected N and nitrapyrin (NI) on growth, yield and yield components of maize grown in soybean-corn (SB-C) and corn-corn (C-C) rotations, (ii) determine if a mixed soil N source may alleviate all or part of the inherent yield reduction caused by maize grown in C-C rotation, and (iii) determine if different hybrids grown in rotation respond similarly to mixed soil nitrogen sources;Three field experiments were conducted in 1990, 1991, and 1992 in C-C and SB-C rotations and with soil potassium (K) variables. Adequate N fertilizer for the corn was applied preplant. Rates of urea ammonium nitrate (UAN) solution and NI were point injected in a factorial combination at V4, V6, or V8 stages of corn development to vary ammonium ion content in the soil. Soil samples were used to monitor soil NH[subscript]4-N and NO[subscript]3-N concentrations;Grain yield of corn was 15 to 26% greater and the yield components seed mass and seeds plant[superscript]-1 were up to 15 and 13% greater for high K fertility compared with low K fertility, respectively. Treatment with UAN at V4 increased seeds plant[superscript]-1 by 4.5% compared to V6 or V8, and addition of 90 kg N ha[superscript]-1 produced 4.8% more grain yield than 45 kg N ha[superscript]-1. Nitrapyrin maintained an enhanced NH[subscript]4-N supply up to 8-wk post application. Soil ammonium to nitrate ratios were as high as 3:1 with 3.6 L NI ha[superscript]-1 compared with no NI;Low K fertility contributed to reduced seed mass, fewer seeds plant[superscript]-1, and reduced yield compared to high K fertility. Point injected N increased seed mass and seed plant[superscript]-1, which contributed to increased grain yield. The negative effect of C-C rotation could not be reduced by an enhanced soil ammonium supply

Lifespan Regulation by Evolutionarily Conserved Genes Essential for Viability

Evolutionarily conserved mechanisms that control aging are predicted to have prereproductive functions in order to be subject to natural selection. Genes that are essential for growth and development are highly conserved in evolution, but their role in longevity has not previously been assessed. We screened 2,700 genes essential for Caenorhabditis elegans development and identified 64 genes that extend lifespan when inactivated postdevelopmentally. These candidate lifespan regulators are highly conserved from yeast to humans. Classification of the candidate lifespan regulators into functional groups identified the expected insulin and metabolic pathways but also revealed enrichment for translation, RNA, and chromatin factors. Many of these essential gene inactivations extend lifespan as much as the strongest known regulators of aging. Early gene inactivations of these essential genes caused growth arrest at larval stages, and some of these arrested animals live much longer than wild-type adults. daf-16 is required for the enhanced survival of arrested larvae, suggesting that the increased longevity is a physiological response to the essential gene inactivation. These results suggest that insulin-signaling pathways play a role in regulation of aging at any stage in life

Independent Expert Scientific Panel – Report on Unconventional Oil and Gas

No abstract available

Mechanical Properties of Hydroxyapatite-Zirconia Compacts Sintered by Two Different Sintering Methods

Microwave sintering is traditionally employed to reduce the sintering temperature required to densify powder compacts. The effect of microwave heating on hydroxyapatite (HA)-zirconia (ZrO2) green bodies has been investigated in order to understand how microwave energy may affect the physical and mechanical properties of the resultant densified composites. Laboratory synthesised nano-sized HA and a commercial nano-sized ZrO2 powder have been ball milled to create mixtures containing 0-5 wt% ZrO2 loadings. Compacts were microwave sintered at either 700, 1000 or 1200°C with a 1 h hold time. Comparative firings were also performed in a resistive element furnace using the same heating profile in order to assess the differences between conventional and microwave heating on the physical, mechanical and microstructural properties of the composites. Samples sintered at 700°C show little sign of densification with open porosities of approximately 50%. Composites conventionally sintered at 1000°C were between 65 and 75% dense, whereas the samples microwave sintered at this temperature were between 55 and 65% dense. Samples sintered at 1200°C showed the greatest degree of densification (\u3e80%) with a corresponding reduction in open porosities. TCP generation occurred as a consequence of sintering at 1200°C, even with 0 wt% ZrO2, and increased degradation of the HA phase to form significant amounts of TCP occurred with increasing additions of ZrO2, along with increasing open porosity. Nanosized ZrO2 prevents the densification of the HA matrix by effectively pinning grain boundaries and this effect is more pronounced in the MS materials. Similar strengths are achieved between the microwave and conventionally sintered samples. Greater amount of open porosity and pore interconnectivity are seen in the MS samples, which are considered to be useful for biomedical applications as they can promote osteo-integration. © 2009 Springer Science+Business Media, LLC

Investigating the Effect of SiO2-TiO2-CaO-Na 2O-ZnO Bioactive Glass Doped Hydroxyapatite: Characterisation and Structural Evaluation

The effects of increasing bioactive glass additions, SiO2-TiO2-CaO-Na2O-ZnO up to 25 wt% in increments of 5 wt%, on the physical and mechanical properties of hydroxyapatite (HA) sintered at 900, 1000, 1100 and 1200°C for 2 h was investigated. Increasing both the glass content and the temperature resulted in increased HA decomposition. This resulted in the formation of a number of bioactive phases. However the presence of the liquidus glass phase did not result in increased densification levels. At 1000 and 1100°C the additions of 5 wt% glass resulted in a decrease in density which never recovered with increasing glass content. At 1200°C a cyclic pattern resulted from increasing glass content. There was no direct relationship between strength and density with all samples experiencing no change or a decrease in strength with increasing glass content. Weibull statistics displayed no pattern with increasing glass content. © 2014 Springer Science+Business Media

The development and validation of a human screening model of tobacco abstinence

Introduction Given the low efficacy of smoking cessation methods, an experimental medicine model indicating smoking abstinence would be of great benefit to the development of new treatments. Hence the sensitivity of cognitive tasks and ambulatory craving measures to smoking abstinence were investigated. Methods Cognitive tasks and ambulatory ratings of craving were assessed for sensitivity to acute abstinence (experiment 1), and nicotine replacement therapy administration (NRT) (experiment 2). Results In experiment 1 go/no-go performance was improved (Mean Difference [MD] -0.99, 95% CI: −1.90 to −0.08) and craving was lower (Regression Coefficient [RC] −33.39, 95% CI: -39.96 to -26.82) in satiated compared with abstinent smokers. There was no clear evidence that N-back (MD 0.64, 95% CI: −0.42 to 2.51), delay discounting (MD 0.01, 95% CI: 0.001 to 0.005) or dot probe performance (MD 0.61, 95% CI: −0.87 to 1.54) were sensitive to acute abstinence. In experiment 2 go/no-go performance was improved (MD 1.12, 95% CI: 0.16–2.08) and craving was lower (RC −18.59, 95% CI: −24.63 to −12.55) smokers abstinent overnight receiving NRT compared with placebo. There was no clear evidence that N-back (MD −0.25, 95% CI: −1.45 to 0.94), delay discounting (MD 0.01, 95% CI: -0.002 to 0.004) or dot probe performance (MD −0.49, 95% CI: −1.61 to −0.64) were sensitive to NRT. Conclusions Findings from two experiments converge to suggest that abstinence in smokers reliably increases ambulatory craving assessments and, to a lesser extent, decreases go/no-go task performance. These findings can be utilized in the development of an experimental medicine model to test novel treatments for smoking cessation

Processing of alcohol-related health threat in at-risk drinkers: an online study of gender-related self-affirmation effects

Aims: Defensiveness in response to threatening health information related to excessive alcohol consumption prevents appropriate behaviour change. Alternatively, self-affirmation may improve cognitive-affective processing of threatening information, thus contributing to successful self-regulation. Methods: Effects of an online self-affirmation procedure were examined in at-risk university student drinkers. Participants were randomly assigned to a self-affirmation (writing about personally relevant values) or control task (writing about values relevant to another person) prior to presentation of alcohol-related threatening information. Assessment of prosocial feelings (e.g. ‘love’) after the task served as a manipulation check. Generic and personalized information regarding the link between alcohol use and cancer was presented, followed by assessment of perceived threat, message avoidance and derogation. Page dwell-times served as indirect indices of message engagement. Alcohol consumption and intention to drink less were assessed during the first online session and at 1-week and 1-month follow-up. Results: Although self-affirmation resulted in higher levels of prosocial feelings immediately after the task, there was no effect on behaviour in the self-affirmation group. Effects on intention were moderated by gender, such that men showed lower intention immediately after self-affirmation, but this increased at 1-week follow-up. Women's intention to reduce consumption in the self-affirmation group reduced over time. Trend-level effects on indices of derogation and message acceptance were in the predicted direction only in men. Conclusion: It is feasible to perform self-affirmation procedures in an online environment with at-risk drinkers. However, use of internet-based procedures with this population may give rise to (gender-dependent) effects that are substantially diluted compared with lab-based experiments

Auntie knows best? public broadcasters and current affairs knowledge

Public service broadcasters (PSBs) are a central part of national news media landscapes. In many countries, PSBs are the first choice of citizens when it comes to news providers. And in perhaps more countries still, PSBs are thought of as specialists in provision of hard news. We test this proposition here using survey data from a large crossnational survey involving indicators of current affairs knowledge and media consumption. Specifically, we examine whether exposure to public versus commercial news influences the knowledge citizens possess about current affairs, both domestically and internationally. We also test, using propensity score analysis, whether there is variation across PSBs in this regard. Results indicate that compared to commercial news, watching PSB has a net positive influence on knowledge of hard news, though not all PSBs are equally effective in contributing to knowledge acquisition. This knowledge gap between PSB and commercial news media consumption appears to be mitigated by factors such as de jure independence,proportion of public financing, and audience share

Travelling for Umrah:destination attributes, destination image, and post-travel intentions

This paper examines the links between cosmopolitanism, self-identity, and a desire for social interaction perceived destination image and behavioural intentions. A model tested using a sample of 538 Iranian visitors to Mecca for the purpose of Umrah. The result from the structural model suggests that destination attributes influence perceived destination image. Further, such tourists are likely to revisit or recommend Islamic destinations if their experience matches their perceived image of the destination. This implies that, while the religious characteristics of the destination remain important, destination managers cannot disregard the tangential, non-religious attributes of a destination which are crucial in order to satisfy more conventional tourist desires. As such, this study suggests that those managing religious travel destinations should endeavour to foster a welcoming image, where experience, interaction and tolerance are at the forefront of the destination’s offering