Effects of green manure crops on short-term nitrogen availability in organic sweet corn systems : a thesis presented in partial fulfilment of the requirements for the degree of Master of Applied Science in Soil Science

In the Gisborne Region of New Zealand (NZ) many organic sweet corn growers use a range of winter green manure crops as a means of maintaining and improving soil fertility, particularly the availability of soil N. Some debate exists as to the most suitable green manure crops and their effectiveness at improving short-term N availability for subsequent sweet corn crops. Two field trials were conducted in the Gisborne Region to assess the effectiveness of four winter green manure crops using a subsequent sweet corn crop to evaluate N availability. Two sites, Site-A at Tekaraka and Site-B at Tolaga Bay, with BIO-GROW NZ organic certification were used in this study. A Latin Square trial design was used at each site consisting of 25 plots made up of five replicates of each of the following five treatments: control (bare soil), blue lupin (Lupinus angustifolus), mustard (Brassica sp.), mustard/blue lupin mix and annual ryegrass (Lolium multiflorum). Just prior to the soil incorporation of green manure treatments (early-mid September 1997), the lupin crop had the highest N concentration and N accumulation levels of 2.1% N and 156 kg N ha-1, respectively, at Site-A and 2.1% N and 173 kg N ha-1, respectively at Site-B. Soil incorporation of green manure treatments significantly influenced soil (0-150 mm) mineral N (nitrate and ammonium) levels measured at sweet corn emergence (30 November 1997) and at 51/2 weeks post emergence. At sweet corn emergence the lupin, mustard/lupin mix, mustard, control and ryegrass treatments resulted in soil mineral N values of 68, 66, 57, 51 and 29 kg.N.ha-1, respectively, at Site-A and 118, 118, 91, 81 and 54 kg.N.ha-1, respectively, at Site B. At both sites, the lupin and mustard/lupin mix treatments resulted in soil mineral N levels significantly higher than the control treatment. In contrast, the ryegrass treatment resulted in soil mineral N levels significantly lower than the control treatment. These treatment effects were related to green manure crop N concentrations just prior to soil incorporation. On average over both sites, the lupin and mustard/lupin mix treatments, which had high DM yields (7900 kg and 6500 kg.DM.ha-1 respectively), had the highest N concentrations (2.0% and 2.1% N respectively). The ryegrass treatment, which also accumulated a high average DM yield (6200 kg.DM.ha-1), contained the lowest average N concentration of only 1.1% N. Sweet corn N accumulation at harvest was also significantly influenced by green manure treatments. At both sites, ryegrass significantly reduced sweet corn N accumulation compared with all other treatments, being 44% and 36% lower than control treatment value of 117 kg.N.ha-1. At Site-A, the lupin, mustard/lupin and mustard treatment effects on sweet corn N accumulation were not different from that of the control treatment at final harvest. However, at Site-B the lupin and mustard/lupin mix treatments did produce sweet corn N accumulation levels significantly higher than the control treatment; being 21% and 18% higher than the control value of 102 kg.N.ha-1, respectively. Compared to the control treatment sweet corn yield (17.3 t ha-1 averaged over both sites), none of the four green manure treatments improved sweet corn yield even though the lupin and mustard/lupin mix treatments both increased soil N availability and sweet corn N accumulation. Soil moisture limitations probably restricted yield potentials. However, the ryegrass treatment detrimentally affected sweet corn yields at both sites. When compared to the control treatment reductions of 64% and 48% at Site-A and Site-B, respectively, were measured. Soil mineral N (0-150 mm) tested early in the sweet corn growing season gave a better relationship with sweet corn N accumulation and yield compared with the incubation tests used. Short-term soil incubation tests, conducted under aerobic and anaerobic conditions, were not useful as indicators of net N mineralisation as they did not relate well to actual soil N mineralisation or crop response. Although both the lupin and the mustard/lupin mix treatments had similar effects on soil N availability and sweet corn N accumulation, of the two the lupin treatment achieved a higher level of estimated N fixation. On average the estimated N fixation in the lupin treatment (98 kg N ha-1 averaged over both sites) was higher than N losses in harvested sweet corn ears (77 kg N ha-1 averaged over both sites). This positive N balance would help compensate for other possible N losses from the soil-plant system (ie. ammonia volatilisation or nitrate leaching). Overall, the lupin green manure treatment appears be the best crop in terms of improving short-term N availability for the subsequent sweet corn crop and for maintaining an N balance in the soil-plant system. But ultimately, the benefit of lupin as a green manure crop will also depend on environmental conditions and management practices

Cancer And Premature Mortality In Ireland: An Employer's Perspective Following The Friction Cost Approach.

Cancer is the second leading cause of death in Ireland accounting for approximately 30% of all deaths. Of these, almost a third arise in those of working age. As well as the public health burden, cancer also imposes economic costs on society in general and employers in particular. This study measured the productivity costs associated with cancer-related premature mortality from an employer’s perspective in Ireland

PC3 Breast and Prostate Cancer Productivity Costs: A Comparison of the Human Capital Approach and Friction Cost Approach

AbstractObjectivesProductivity costs constitute a substantial proportion of the total societal costs associated with cancer. We compared the results of applying two different analytical methods—the traditional human capital approach (HCA) and the emerging friction cost approach (FCA)—to estimate breast and prostate cancer productivity costs in Ireland in 2008.MethodsData from a survey of breast and prostate cancer patients were combined with population-level survival estimates and a national wage data set to calculate costs of temporary disability (cancer-related work absence), permanent disability (workforce departure, reduced working hours), and premature mortality.ResultsFor breast cancer, productivity costs per person using the HCA were €193,425 and those per person using the FCA were €8,103; for prostate cancer, the comparable estimates were €109,154 and €8,205, respectively. The HCA generated higher costs for younger patients (breast cancer) because of greater lifetime earning potential. In contrast, the FCA resulted in higher productivity costs for older male patients (prostate cancer) commensurate with higher earning capacity over a shorter time period. Reduced working hours postcancer was a key driver of total HCA productivity costs. HCA costs were sensitive to assumptions about discount and growth rates. FCA costs were sensitive to assumptions about the friction period.ConclusionsThe magnitude of the estimates obtained in this study illustrates the importance of including productivity costs when considering the economic impact of illness. Vastly different results emerge from the application of the HCA and the FCA, and this finding emphasizes the importance of choosing the study perspective carefully and being explicit about assumptions that underpin the methods

Projecting productivity losses for cancer-related mortality 2011 - 2030

© 2016 The Author(s). Background: When individuals stop working due to cancer this represents a loss to society - the loss of productivity. The aim of this analysis was to estimate productivity losses associated with premature mortality from all adult cancers and from the 20 highest mortality adult cancers in Ireland in 2011, and project these losses until 2030. Methods: An incidence-based method was used to estimate the cost of cancer deaths between 2011 and 2030 using the Human Capital Approach. National data were used for cancer, population and economic inputs. Both paid work and unpaid household activities were included. Sensitivity analyses estimated the impact of assumptions around future cancer mortality rates, retirement ages, value of unpaid work, wage growth and discounting. Results: The 233,000 projected deaths from all invasive cancers in Ireland between 2011 and 2030 will result in lost productivity valued at €73 billion; €13 billion in paid work and €60 billion in household activities. These losses represent approximately 1.4 % of Ireland's GDP annually. The most costly cancers are lung (€14.4 billion), colorectal and breast cancer (€8.3 billion each). However, when viewed as productivity losses per cancer death, testis (€364,000 per death), cervix (€155,000 per death) and brain cancer (€136,000 per death) are most costly because they affect working age individuals. An annual 1 % reduction in mortality reduces productivity losses due to all invasive cancers by €8.5 billion over 20 years. Conclusions: Society incurs substantial losses in productivity as a result of cancer-related mortality, particularly when household production is included. These estimates provide valuable evidence to inform resource allocation decisions in cancer prevention and control

Intraoperative frozen section assessment of sentinel lymph nodes in the operative management of women with symptomatic breast cancer

<p>Abstract</p> <p>Background</p> <p>Maximisation of the potential of sentinel lymph node biopsy as a minimally invasive method of axillary staging requires sensitive intraoperative pathological analysis so that rates of re-operation for lymphatic metastases are minimised. The aim of this study was to describe the test parameters of the frozen section evaluation of sentinel node biopsy for breast cancer compared to the gold standard of standard permanent pathological evaluation at our institution.</p> <p>Methods</p> <p>The accuracy of intraoperative frozen section (FS) of sentinel nodes was determined in 94 consecutive women undergoing surgery for clinically node negative, invasive breast cancer (37:T1 disease; 43:T2; 14:T3). Definitive evidence of lymphatic spread on FS indicated immediate level II axillary clearance while sentinel node "negativity" on intraoperative testing led to the operation being curtailed to allow formal H&E analysis of the remaining sentinel nodal tissue.</p> <p>Results</p> <p>Intraoperative FS correctly predicted axillary involvement in 23/30 patients with lymphatic metastases (76% sensitivity rate) permitting definitive surgery to be completed at the index operation in 87 women (93%) overall. All SN found involved on FS were confirmed as harbouring tumour cells on subsequent formal specimen examination (100% specificity and positive predictive value) with 16 patients having additional non-sentinel nodes found also to contain tumour. Negative Predictive Values were highest in women with T1 tumours (97%) and lessened with more local advancement of disease (T2 rates: 86%; T3: 75%). Of those with falsely negative FS, three had only micrometastatic disease.</p> <p>Conclusion</p> <p>Intraoperative FS reliably evaluates the status of the sentinel node allowing most women complete their surgery in a single stage. Thus SN can be offered with increased confidence to those less likely to have negative axillae hence expanding the population of potential beneficiaries.</p

Collaborative Gaze Channelling for Improved Cooperation During Robotic Assisted Surgery

The use of multiple robots for performing complex tasks is becoming a common practice for many robot applications. When different operators are involved, effective cooperation with anticipated manoeuvres is important for seamless, synergistic control of all the end-effectors. In this paper, the concept of Collaborative Gaze Channelling (CGC) is presented for improved control of surgical robots for a shared task. Through eye tracking, the fixations of each operator are monitored and presented in a shared surgical workspace. CGC permits remote or physically separated collaborators to share their intention by visualising the eye gaze of their counterparts, and thus recovers, to a certain extent, the information of mutual intent that we rely upon in a vis-à-vis working setting. In this study, the efficiency of surgical manipulation with and without CGC for controlling a pair of bimanual surgical robots is evaluated by analysing the level of coordination of two independent operators. Fitts' law is used to compare the quality of movement with or without CGC. A total of 40 subjects have been recruited for this study and the results show that the proposed CGC framework exhibits significant improvement (p<0.05) on all the motion indices used for quality assessment. This study demonstrates that visual guidance is an implicit yet effective way of communication during collaborative tasks for robotic surgery. Detailed experimental validation results demonstrate the potential clinical value of the proposed CGC framework. © 2012 Biomedical Engineering Society.link_to_subscribed_fulltex

Glucocorticoid use and factors associated with variability in this use in the Systemic Lupus International Collaborating Clinics Inception Cohort

© The Author(s) 2018. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. Objectives. To describe glucocorticoid (GC) use in the SLICC inception cohort and to explore factors associated with GC use. In particular we aimed to assess temporal trends in GC use and to what extent physician-related factors may influence use. Methods. Patients were recruited within 15 months of diagnosis of SLE from 33 centres between 1999 and 2011 and continue to be reviewed annually. Descriptive statistics were used to detail oral and parenteral GC use. Cross sectional and longitudinal analyses were performed to explore factors associated with GC use at enrolment and over time. Results. We studied 1700 patients with a mean (S.D.) follow-up duration of 7.26 (3.82) years. Over the entire study period, 1365 (81.3%) patients received oral GCs and 447 (26.3%) received parenteral GCs at some point. GC use was strongly associated with treatment centre, age, race/ethnicity, sex, disease duration and disease activity. There was no change in the proportion of patients on GCs or the average doses of GC used over time according to year of diagnosis. Conclusion. GCs remain a cornerstone in SLE management and there have been no significant changes in their use over the past 10-15 years. While patient and disease factors contribute to the variation in GC use, between-centre differences suggest that physician-related factors also contribute. Evidence-based treatment algorithms are needed to inform a more standardized approach to GC use in SLE