Automation and control in surface irrigation systems: current status and expected future trends

Surface irrigation systems are the most popular methods for irrigating crops and pastures not only in Australia but the world over. However, these systems are often labour intensive and exhibit low water use efficiency. Rising labour costs especially in the developed world and competition for scarce water resources have generated renewed interest in the automation of surface irrigation systems. This paper provides a comprehensive review of the current level of automation and control of surface irrigation systems. The automation techniques discussed utilise various devices including mechanical, electronic, pneumatic and hydraulic means. The use of telemetry is also discussed. With the almost universal access to high performance computers and fast internet, the concept of real-time control in surface irrigation is not far-fetched. Towards this end, an on-going research project at USQ aimed at modernising furrow irrigation by use of automatic control systems in real time is discusse

Irrigated agriculture responds to water use challenges

Presented at Irrigated agriculture responds to water use challenges - strategies for success: USCID water management conference held on April 3-6, 2012 in Austin, Texas.Includes bibliographical references.A system for the real-time optimization of furrow irrigation is described. The system estimates the soil infiltration characteristics in real-time and utilizes the data to control the same irrigation event to give optimum performance for the current soil conditions. The main features of the system are: the use of a model infiltration curve and a scaling process to describe the current soil infiltration characteristic; measurement of the inflow rate to the furrows; measurement of the water advance at a point approximately midway down the furrow; and a microcomputer running a hydraulic simulation program based on the full hydrodynamic model to predict the optimum time to cut-off. The system was trialed on a furrow-irrigated commercial cotton property utilizing pipes through the bank (PTBs) to supply groups of furrows. The initial observations from these trials are presented in this paper and demonstrate that improvements in water use efficiency are potentially achievable through the use of the system. Extensions to the system to improve its performance and to make it applicable to bay irrigation are described

Hydrodynamic propulsion of human sperm

The detailed fluid mechanics of sperm propulsion are fundamental to our understanding of reproduction. In this paper, we aim to model a human sperm swimming in a microscope slide chamber. We model the sperm itself by a distribution of regularized stokeslets over an ellipsoidal sperm head and along an infinitesimally thin flagellum. The slide chamber walls are modelled as parallel plates, also discretized by a distribution of regularized stokeslets. The sperm flagellar motion, used in our model, is obtained by digital microscopy of human sperm swimming in slide chambers. We compare the results of our simulation with previous numerical studies of flagellar propulsion, and compare our computations of sperm kinematics with those of the actual sperm measured by digital microscopy. We find that there is an excellent quantitative match of transverse and angular velocities between our simulations and experimental measurements of sperm. We also find a good qualitative match of longitudinal velocities and computed tracks with those measured in our experiment. Our computations of average sperm power consumption fall within the range obtained by other authors. We use the hydrodynamic model, and a prototype flagellar motion derived from experiment, as a predictive tool, and investigate how sperm kinematics are affected by changes to head morphology, as human sperm have large variability in head size and shape. Results are shown which indicate the increase in predicted straight-line velocity of the sperm as the head width is reduced and the increase in lateral movement as the head length is reduced. Predicted power consumption, however, shows a minimum close to the normal head aspect ratio

Comorbid depression and risk of cardiac events and cardiac mortality in people with diabetes: A systematic review and meta-analysis

Objective: To examine the association of comorbid occurrence of diabetes and depression with risk of cardiovascular endpoints including cardiovascular mortality, coronary heart disease and stroke. Research Design and Methods: A systematic review and metaanalysis. We searched PUBMED/MEDLINE, Medscape, Cochrane Library, CINAHL, EMBASE and Scopus databases assessing cardiac events and mortality associated with depression in diabetes up until 1 December 2018. Pooled hazard ratios were calculated using random- effects models. Results: Nine studies met the inclusion criteria. The combined pooled hazard ratios showed a significant association of cardiac events in people with depression and type 2 diabetes, compared to those with type 2 diabetes alone. For cardiovascular mortality the pooled hazard ratio was 1.48 (95% CI: 1.185, 1.845), p=0.001, for coronary heart disease 1.37 (1.165, 1.605), p?0.001 and for stroke 1.33 (1.291, 1.369), p?0.001. Heterogeneity was high in the meta-analysis for stroke events (I-squared = 84.7%) but was lower for coronary heart disease and cardiovascular mortality (15% and 43.4% respectively). Meta-regression analyses showed that depression was not significantly associated with the study level covariates mean age, duration of diabetes, length of follow-up, BMI, sex and ethnicity (p?0.05 for all models). Only three studies were found that examined the association of depression in type 1 diabetes, there was a high degree of heterogeneity and data synthesis was not conducted for these studies. Conclusions: We have demonstrated a 47.9% increase in cardiovascular mortality, 36.8% increase in coronary heart disease and 32.9% increase in stroke in people with diabetes and comorbid depression. The presence of depression in a person with diabetes should trigger the consideration of evidence-based therapies for cardiovascular disease prevention irrespective of the baseline risk of cardiovascular disease or duration of diabetes

Strategic toolkits: seniority, usage and performance in the German SME machinery and equipment sector

This paper examines the strategic tool kit, from a human resource management (HRM) perspective, in terms of usage and impact. Research to date has tended to consider usage, assuming to a certain extent that knowledge and understanding of particular tools suggest that practitioners value them. The research on which this paper is based builds upon the idea that usage indicates satisfaction, but develops the usage theme to investigate which decision-makers are actually engaged in both tool appliance and the strategic process. Of particular interest to the researchers are the educational background, age and seniority of the decision-makers. In addition, potential links with HRM and organizational performance are also explored. The context of the research, the German machinery and equipment sector, provides an insight into the industry's ability to sustain growth in face of increasing international competition. The paper calls for a greater awareness, from a human resource perspective, and utilization of strategic management practice and associated decision-making aids

Current issues and future considerations for the wider implementation of robotic-assisted surgery : a qualitative study

Acknowledgments We thank the participants for their time, energy and invaluable insight to assist this research. Thanks to Clare Robertson for facilitating the public focus group. Funding This work was supported by Intuitive Surgical (European Research Board) via an unrestricted grant.Peer reviewedPublisher PD

Laparoscopic vs. open feeding jejunostomy insertion in oesophagogastric cancer.

BACKGROUND: Jejunal feeding is an invaluable method by which to improve the nutritional status of patients undergoing neoadjuvant and surgical treatment of oesophageal malignancies. However, the insertion of a feeding jejunostomy can cause significant postoperative morbidity. The aim of this study is to compare the outcomes of patients undergoing placement of feeding jejunostomy by conventional laparotomy with an alternative laparoscopic approach. METHODS: A retrospective review of data prospectively collected at the Oxford Oesophagogastric Centre between August 2017 and July 2019 was performed including consecutive patients undergoing feeding jejunostomy insertion. RESULTS: In the study period, 157 patients underwent jejunostomy insertion in the context of oesophageal cancer therapy, 126 (80%) by open technique and 31 (20%) laparoscopic. Pre-operative demographic and nutritional characteristics were broadly similar between groups. In the early postoperative period jejunostomy-associated complications were noted in 54 cases (34.4%) and were significantly more common among those undergoing open as compared with laparoscopic insertion (38.1% vs. 19.3%, P = 0.049). Furthermore, major complications were more common among those undergoing open insertion, whether as a stand-alone or at the time of staging laparoscopy (n = 11/71), as compared with insertion at the time of oesophagectomy (n = 3/86, P = 0.011). CONCLUSIONS: This report represents the largest to our knowledge single-centre comparison of open vs. laparoscopic jejunostomy insertion in patients undergoing oesophagectomy in the treatment of gastroesophageal malignancy. We conclude that the laparoscopic jejunostomy insertion technique described represents a safe and effective approach to enteral access which may offer superior outcomes to conventional open procedures

Understanding prehospital blood transfusion decision-making for injured patients : an interview study

Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.Peer reviewe

Shady business: understanding the spatial ecology of exophilic Anopheles mosquitoes

Background: Understanding the ecology of exophilic anophelines is a key step toward developing outdoor control strategies to complement existing indoor control tools against malaria vectors. This study was conducted to assess the movement pattern of exophilic Anopheles mosquitoes between blood meal sources and resting habitats, and the landscape factors dictating their resting habitat choice. Results: Resting clay pots were placed at 5 m, 25 m, 50 m, 75 m and 100 m away from isolated focal houses, radiating from them in four directions. The locations of the clay pots represent heterogeneous land cover types at a relatively fine spatial scale in the landscape. The effect of the landscape characters on the number of both female and male anophelines caught was modelled using zero-inflated negative binomial regression with a log link function. A total of 420 Anopheles mosquitoes (353 females and 67 males) belonging to three species; Anopheles arabiensis, Anopheles pharoensis, and Anopheles tenebrosus were caught in the resting clay pots, with An. arabiensis being the dominant species. Canopy cover, distance from the house, and land cover type were the significant landscape characters influencing the aggregation of resting mosquitoes. Both the count and binary models showed that canopy cover was the strongest predictor variable on the counts and the presence of Anopheles mosquitoes in the clay pots. Female Anopheles were most frequently found resting in the pots placed in banana plantations, and at sampling points that were at the greater distances (75 m and 100 m) from the focal house. Conclusions: This study showed that exophilic Anopheles mosquitoes tend to rest in shaded areas some distance away from human habitation. These findings are important when targeting mosquitoes outdoors, complementing the existing effort being made to control malaria vectors indoors