A Strategic Soil Nitrogen Test For Flooded Rice

From 1998 until 2002 a project to develop a soil nitrogen (N) test for flooded rice was conducted in the Rice CRC. The reason for wanting such a test for the Australian rice industry is that N fertiliser is used more efficiently when applied before sowing so it is economically and environmentally preferable for as much as possible of the optimum amount of N fertiliser to be applied at that time. However excessive N applied before sowing leads to a high risk of yield loss due to cold damage. The aim was to develop a system to forecast the optimum N supply for pre-flood application and minimize the amount being topdressed which has been a safe, but inefficient system. The method of developing the test was first to compare the near infrared reflectance (NIR) spectra with crop productivity and N mineralisation measured by wet chemistry. These measurements were made with soil from 22 previous experiments measuring yield response to N applied at sowing. There were close relationships of the NIR spectra with crop productivity and N mineralisation but because of the small data set the relationships had little predictive value. However the close relationships found between NIRS, N mineralisation measured in the laboratory and crop performance encouraged us to proceed with further studies. A more detailed study related soil mineralisation across farms to crop performance. Seventeen methods of mineralisation were tested and the most reliable was found to be anaerobic incubation at 40°C for 21 days. This method predicted the optimum N requirement with a standard error of about 75 kgN/ha, which is clearly unsatisfactory for an industry where the average amount of N fertiliser applied is 145 kgN/ha. A possible reason for the low correlation between mineralisation and crop performance was that other factors were limiting N response. There was some evidence that sowing date and deficiencies of other nutrients were partly responsible for the variability of the N response. However it is unlikely that including information about these factors would lift the soil-N test to acceptable accuracy for commercial use. The most likely reason for the low correlation was that the soil depth used for mineralisation measurements was poorly defined because of the widespread levelling of rice fields which led to different depths of topsoil. Two options are proposed for more reliable application of N fertiliser at the time of sowing. Both require further research. One is to use the existing soil test only to identify soils with large amounts of potentially mineralisable N. Such a test could be the basis of a recommendation to apply little or no N fertiliser before sowing. Rice growers would still have the option of topdressing N fertiliser at the panicle initiation stage. The advantage of using a test in this way is that it is most unlikely to result in ‘false positives’, i.e. - recommendations for excessive N fertiliser leading to yield reductions. The other option is to set up a system of zone management for N fertiliser based on the likely N mineralisation in different parts of a rice field. The results in this project suggest that yield responses are more accurately predicted by sodicity than by the soil N test. It is likely that sodicity is a good indication of the depth of topsoil cut in the process of levelling. If this result is shown to be general, maps of ‘cut and fill’ areas may help in deciding the optimum amount of N fertiliser. Evidence from the Ricecheck database shows that about 10% of rice paddocks receive too much N fertiliser at sowing and suffer a large yield reduction. This leads to an annual loss of about $18 m. While this project has not led to a solution to this problem, the two suggestions arising from the project offer methods to reduce the problem

Simulation of Pasture Phase Options for Mixed Livestock and Cropping Enterprises

In southern Australia, 50% of grain-producing farms also run beef and/or sheep enterprises. Legume pasture leys are used to replace soil nitrogen and manage crop disease risks. Deep-rooted perennials, predominantly lucerne (Medicago sativa), are replacing annual Trifolium subterraneum-based leys to increase pasture production. They also have the environmental benefits of limiting soil acidity, rising water tables and dryland salinity. After recent droughts depletion of soil water by lucerne has penalised wheat yields. Decision support tools can help farmers evaluate the long-term effects of grazed annual and perennial leys on animal and crop production at the whole farm level

Neck exercises compared to muscle activation during aerial combat maneuvers

Introduction: Performing specific neck strengthening exercises has been proposed to decrease the incidence of neck injury and pain in high performance combat pilots. However, there is little known about these exercises in comparison to the demands on the neck musculature in flight. Methods: Eight male non-pilots performed specific neck exercises using two different modalities (elastic band and resistance machine) at six different intensities in flexion, extension, and lateral bending. Six Royal Australian Air Force Hawk pilots flew a sortie that included combinations of three +Gz levels and four head positions. Surface electromyography (EMG) from selected neck and shoulder muscles was recorded in both activities. Results: Muscle activation levels recorded during the three elastic band exercises were similar to in-flight EMG collected at +1 Gz (15% MVIC). EMG levels elicited during the 50% resistance machine exercises were between the +3 Gz (9-40% MVIC) and +5 Gz (16-53% MVIC) ranges of muscle activations in most muscles. EMG recorded during 70% and 90% resistance machine exercises were generally higher than in-flight EMG at +5 Gz. Discussion: Elastic band exercises could possibly be useful to pilots who fly low +Gz missions while 50% resistance machine mimicked neck loads experienced by combat pilots flying high +Gz ACM. The 70% and 90% resistance machine intensities are known to optimize maximal strength but should be administered with care because of the unknown spinal loads and diminished muscle force generating capacity after exercise.<br /

Nitrogen Mineralization from Root Residues of Subterranean Clover and Lucerne

To understand why crops grown in the first or second year after lucerne (Medicago sativa L.) yielded less than crops grown after subterranean clover (Trifolium subterraneum L.) despite greater nitrogen (N) fixation by the lucerne, we studied the N mineralization patterns of their root residues in soil incubation assays. Fine roots of both species produced more mineral N than the control soil with no root residues. In contrast, coarse roots mineralized less N than the control soil. These differences in N mineralization were not explained by the physical size and therefore surface area differences between fine and coarse roots. Rather, the differences in N mineralization were explained by differences in the carbon to nitrogen ratio (C:N) of fine and coarse roots. Fine roots of both species had a C:N of about 11, while the C:N of coarse roots ranged from 28 to 37. Empirical evidence suggests that a mineralization / immobilization threshold occurs at a C:N of 20 to 30, and these results are in accordance with this interpretation. However, subterranean clover had mainly fine roots giving a weighted average C:N of 19 for the whole root system, while lucerne had mainly coarse roots giving an average C:N of 26, suggesting that root residues of subterranean clover result in a net mineralization of N while lucerne roots cause a net immobilization of N

Physical Mechanisms of Tropical Climate Feedbacks Investigated Using Temperature and Moisture Trends

ArticleOpen access articleTropical climate feedback mechanisms are assessed using satellite-observed and model-simulated trends in tropical tropospheric temperature from the MSU/AMSU instruments and upper-tropospheric humidity from the HIRS instruments. Despite discrepancies in the rates of tropospheric warming between observations and models, both are consistent with constant relative humidity over the period 1979--2008. Because uncertainties in satellite-observed tropical-mean trends preclude a constraint on tropical-mean trends in models we also explore regional features of the feedbacks. The regional pattern of the lapse rate feedback is primarily determined by the regional pattern of surface temperature changes, as tropical atmospheric warming is relatively horizontally uniform. The regional pattern of the water vapor feedback is influenced by the regional pattern of precipitation changes, with variations of 1--2 W m-2 K-1 across the Tropics (compared to a tropical-mean feedback magnitude of 3.3--4 W m-2 K-1). Thus the geographical patterns of water vapor and lapse rate feedbacks are not correlated, but when the feedbacks are calculated in precipitation percentiles rather than in geographical space they are anti-correlated, with strong positive water vapor feedback associated with strong negative lapse rate feedback. The regional structure of the feedbacks is not related to the strength of the tropical-mean feedback in a subset of the climate models from the CMIP5 archive. Nevertheless the approach constitutes a useful process-based test of climate models and has the potential to be extended to constrain regional climate projections.Natural Environment Research Council (NERC

Can MONDian vector theories explain the cosmic speed up ?

Generalized Einstein - Aether vector field models have been shown to provide, in the weak field regime, modifications to gravity which can be reconciled with the successfull MOND proposal. Very little is known, however, on the function F(K) defining the vector field Lagrangian so that an analysis of the viability of such theories at the cosmological scales has never been performed. As a first step along this route, we rely on the relation between F(K) and the MOND interpolating function $\mu(a/a_0)$ to assign the vector field Lagrangian thus obtaining what we refer to as "MONDian vector models". Since they are able by construction to recover the MOND successes on galaxy scales, we investigate whether they can also drive the observed accelerated expansion by fitting the models to the Type Ia Supernovae data. Should be this the case, we have a unified framework where both dark energy and dark matter can be seen as different manifestations of a single vector field. It turns out that both MONDian vector models are able to well fit the low redshift data on Type Ia Supernovae, while some tension could be present in the high z regime.Comment: 15 pages, 5 tables, 4 figures, accepted for publication on Physical Review

Initial 4D seismic results after CO 2 injection start-up at the Aquistore storage site

The first post-CO2-injection 3D time-lapse seismic survey was conducted at the Aquistore CO2 storage site in February 2016 using the same permanent array of buried geophones used for acquisition of three previous pre-CO2-injection surveys from March 2012 to November 2013. By February 2016, 36 kilotons of CO2 have been injected within the reservoir between 3170 and 3370 m depth. We have developed time-lapse results from analysis of the first post-CO2-injection data and three pre-CO2-injection data sets. The objective of our analysis was to evaluate the ability of the permanent array to detect the injected CO2. A “4D-friendly simultaneous” processing flow was applied to the data in an effort to maximize the repeatability between the pre- and post-CO2-injection volumes while optimizing the final subsurface image including the reservoir. Excellent repeatability was achieved among all surveys with global normalized root-mean-square (Gnrms) values of 1.13–1.19 for the raw prestack data relative to the baseline data, which decreased during processing to Gnrms values of approximately 0.10 for the final crossequalized migrated data volumes. A zone of high normalized root-mean-square (nrms) values (0.11–0.25 as compared with background values of 0.05–0.10) is identified within the upper Deadwood unit of the storage reservoir, which likely corresponds to approximately 18 kilotons of CO2. No significant nrms anomalies are observed within the other reservoir units due to a combination of reduced seismic sensitivity, higher background nrms values, and/or small quantities of CO2 residing within these zones

Longitudinal study of the relationship between patients' medication adherence and quality of life outcomes and illness perceptions and beliefs about cardiac rehabilitation

Background Adherence to medication regimens is essential for preventing and reducing adverse outcomes among patients with coronary artery disease (CAD). Greater understanding of the relation between negative illness perceptions, beliefs about cardiac rehabilitation (CR) and medication adherence may help inform future approaches to improving medication adherence and quality of life (QoL) outcomes. The aims of the study are: 1) to compare changes in illness perceptions, beliefs about CR, medication adherence and QoL on entry to a CR programme and 6 months later; 2) to examine associations between patients’ illness perceptions and beliefs about CR at baseline and medication adherence and QoL at 6 months. Methods A longitudinal study of 40 patients with CAD recruited from one CR service in Scotland. Patients completed the Medication Adherence Report Scale, Brief Illness Perception Questionnaire, Beliefs about CR questionnaire and the Short-Form 12 Health Survey. Data were analysed using the Wilcoxon Signed Ranks test, Pearson Product Moment correlation and Bayesian multiple logistic regression. Results Most patients were men (70%), aged 62.3 mean (SD 7.84) years. Small improvements in ‘perceived suitability’ of CR at baseline increased the odds of being fully adherent to medication by approximately 60% at 6 months. Being fully adherent at baseline increased the odds of staying so at 6 months by 13.5 times. ‘Perceived necessity, concerns for exercise and practical barriers’ were negatively associated with reductions in the probability of full medication adherence of 50, 10, and 50%. Small increases in concerns about exercise decreased the odds of better physical health at 6 months by about 50%; and increases in practical barriers decreased the odds of better physical health by about 60%. Patients perceived fewer consequences of their cardiac disease at 6 months. Conclusions Patients’ beliefs on entry to a CR programme are especially important to medication adherence at 6 months. Negative beliefs about CR should be identified early in CR to counteract any negative effects on QoL. Interventions to improve medication adherence and QoL outcomes should focus on improving patients’ negative beliefs about CR and increasing understanding of the role of medication adherence in preventing a future cardiac event

ESTUDO LONGITUDINAL DE FATORES QUE AFETAM O RISCO DE FRATURA POR ESTRESSE EM DUAS POPULAÇÕES DE COLEGIAIS DO SEXO FEMININO

Objetivos: As fraturas por estresse causam significante morbidade em mulheres. Diferenças no nível de atividades, valores hormonais e densidade mineral óssea (BMD) afetam diferentemente as taxas de fraturas por estresse. Os autores hipotetizaram que mulheres de um Colégio militar terão maior nível de atividade do que mulheres em colégios com um ambiente mais flexível, que correlacionará com mudanças nos valores hormonais, menor (BMD) e mais fraturas por estresse. Método: Nesse estudo prospectivo comparativo, 63 mulheres de duas Instituições (The Citadel: The Military College Of South Carolina And The College Of Cherleston) relataram detalhadamente suas atividades, dieta e lesões através de um questionário e tiveram sua BMB e os valores hormonais séricos medidos num intervalo de 06 meses, por um período de 2 anos; 38 sujeitos completaram o estudo. A análise estatística examinou diferenças e mudanças ao longo do tempo entre as duas amostras.Resultados: Uma fratura por estresse ocorreu em cada Instituição. As mulheres do Citadel tiveram maiores níveis de atividade, que as mulheres do College of Charleston no longo do estudo. As mulheres do Citadel tiveram menor nível de hormônio folículo estimulante, maior 17 Beta-Estradiol aos 24 meses e maior BMD na extremidade proximal femoral aos 18 meses da investigação (p< 0,05). Conclusões: Os valores séricos hormonais podem ser um indicador mais sensível de resposta ao nível da atividade física que o BMD dentro da amostra e duração deste estudo. Outros estudos são necessários para definir esta complexa interrelação. LONGITUDINAL STUDY OF FACTORS AFFECTING STRESS FRACTURE RISK IN TWO DISTINCT COLLEGE FEMALE POPULATIONS Abstract Objectives: Stress fractures cause significant morbidity in females. Differences in activity levels, hormone values, and bone mineral density (BMD) affect different rates of stress fracture. The authors hypothesized that females at a military college will have greater activity levels than females in a flexible college environment, which will correlate with greater changes in hormone values, lower BMD, and more stress fractures. Methods: In this prospective comparative study 63 females from two institutions (The Citadel: The Military College of South Carolina and the College of Charleston) self-reported on a detailed activity, diet, and injury questionnaire and had BMD and serum hormone values measured at 6- month intervals for a two year period; 38 completed the study. Statistical analysis was designed to examine differences and changes over time between the two samples. Results: One stress fracture occurred in each institution. Citadel females had higher activity levels than females at the College of Charleston throughout the study. Citadel females had lower follicle stimulating hormone levels at 24 months, greater 17 beta-estradiol at 24 months, and greater proximal femoral BMD at eighteen months (