The development of a spatial decision support system to optimise agricultural resource use in the Western Cape

This paper describes the development of a decision support model for regional agricultural resource utilisation. The analysis was generated in a spatial context and the optimisation technique was interactive with a geographical information system (GIS). Economic and operational research methodologies were linked to the GIS in the process of determining the appropriate resource uses for the region. The optimisation technique was applied for the Western Cape Province for eight crops. The results of this research are discussed in this paper, with specific reference to its application value for the public sector and agri-business.Farm Management, Resource /Energy Economics and Policy,

Slant cues are processed with different latencies for the online control of movement

For the online control of movement, it is important to respond fast. The extent to which cues are effective in guiding our actions might therefore depend on how quickly they provide new information. We compared the latency to alter a movement when monocular and binocular cues indicated that the surface slant had changed. We found that subjects adjusted their movement in response to three types of information: information about the new slant from the monocular image, information about the new slant from binocular disparity, and information about the change in slant from the change in the monocular image. Responses to changes in the monocular image were approximately 40 ms faster than responses to a new slant estimate from binocular disparity and about 90 ms faster than responses to a new slant estimate from the monocular image. Considering these delays, adjustments of ongoing movements to changes in slant will usually be initiated by changes in the monocular image. The response will later be refined on the basis of combined binocular and monocular estimates of slant. © ARVO

Perbanyakan Mikro Colocasia Esculenta (L.) Schott Var. Antiquorum melalui Penggunaan IAA

Media perbanyakan in vitrosangat diperlukan untuk meningkatkan kemampuan multipikasi tunas maupun kualitas bibit. Media Murashige Shoog (MS)dapatditambahkanzat pengatur tumbuh sebagai pemacu pertumbuhan dalam kultur in vitro.Penelitian ini bertujuan untuk mendapatkan konsentrasi IAA terbaik bagi pertumbuhan talas jepang dalam kulturin vitro. Perlakuan terdiri dari 4 taraf konsentrasi IAA yaitu I0 (0 mg/L), I1 (0,5 mg/L), I2 (1 mg/L), I3 (1,5 mg/L) yang diulang sebanyak 5 kali dalam rancangan acak kelompok. Hasil penelitian ini menunjukan bahwa pemberian IAA berpengaruh nyata terhadap saat muncul tunas, jumlah tunas, tinggi tunas, jumlah daun dan jumlah akar satoimo. Konsentrasi IAA 0,5 mg/L merupakan konsentrasi terbaik untuk pertumbuhan akar dan saat muncul tunas talas satoimo, sedangkan konsentrasi IAA 1 mg/L merupakan konsentrasi terbaik untuk jumlah tunas, tinggi tunas dan jumlah daun satoimo. Kata kunci: kultur in vitro, talas jepang, IAA, perbanyaka

Shallow rainwater lenses in deltaic areas with saline seepage

In deltaic areas with saline seepage, freshwater availability is often limited to shallow rainwater lenses lying on top of saline groundwater. Here we describe the characteristics and spatial variability of such lenses in areas with saline seepage and the mechanisms that control their occurrence and size. Our findings are based on different types of field measurements and detailed numerical groundwater models applied in the south-western delta of the Netherlands. By combining the applied techniques we could extrapolate measurements at point scale (groundwater sampling, temperature and electrical soil conductivity (TEC)-probe measurements, electrical cone penetration tests (ECPT)) to field scale (continuous vertical electrical soundings (CVES), electromagnetic survey with EM31), and even to regional scale using helicopter-borne electromagnetic measurements (HEM). The measurements show a gradual mixing zone between infiltrating fresh rainwater and upward flowing saline groundwater. The mixing zone is best characterized by the depth of the centre of the mixing zone <i>D</i><sub>mix</sub>, where the salinity is half that of seepage water, and the bottom of the mixing zone <i>B</i><sub>mix</sub>, with a salinity equal to that of the seepage water (Cl-conc. 10 to 16 g l<sup>−1</sup>). <i>D</i><sub>mix</sub> is found at very shallow depth in the confining top layer, on average at 1.7 m below ground level (b.g.l.), while <i>B</i><sub>mix</sub> lies about 2.5 m b.g.l. The model results show that the constantly alternating upward and downward flow at low velocities in the confining layer is the main mechanism of mixing between rainwater and saline seepage and determines the position and extent of the mixing zone (<i>D</i><sub>mix</sub> and <i>B</i><sub>mix</sub>). Recharge, seepage flux, and drainage depth are the controlling factors

Response to recharge variation of thin rainwater lenses and their mixing zone with underlying saline groundwater

In coastal zones with saline groundwater, fresh groundwater lenses may form due to infiltration of rain water. The thickness of both the lens and the mixing zone, determines fresh water availability for plant growth. Due to recharge variation, the thickness of the lens and the mixing zone are not constant, which may adversely affect agricultural and natural vegetation if saline water reaches the root zone during the growing season. In this paper, we study the response of thin lenses and their mixing zone to variation of recharge. The recharge is varied using sinusoids with a range of amplitudes and frequencies. We vary lens characteristics by varying the Rayleigh number and Mass flux ratio of saline and fresh water, as these dominantly influence the thickness of thin lenses and their mixing zone. Numerical results show a linear relation between the normalised lens volume and the main lens and recharge characteristics, enabling an empirical approximation of the variation of lens thickness. Increase of the recharge amplitude causes increase and the increase of recharge frequency causes a decrease in the variation of lens thickness. The average lens thickness is not significantly influenced by these variations in recharge, contrary to the mixing zone thickness. The mixing zone thickness is compared to that of a Fickian mixing regime. A simple relation between the travelled distance of the centre of the mixing zone position due to variations in recharge and the mixing zone thickness is shown to be valid for both a sinusoidal recharge variation and actual records of daily recharge data. Starting from a step response function, convolution can be used to determine the effect of variable recharge in time. For a sinusoidal curve, we can determine delay of lens movement compared to the recharge curve as well as the lens amplitude, derived from the convolution integral. Together the proposed equations provide us with a first order approximation of lens characteristics using basic lens and recharge parameters without the use of numerical models. This enables the assessment of the vulnerability of any thin fresh water lens on saline, upward seeping groundwater to salinity stress in the root zone

Candida albicans Hypha Formation and Mannan Masking of β-Glucan Inhibit Macrophage Phagosome Maturation

Received 28 August 2014 Accepted 28 October 2014 Published 2 December 2014 This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 Unported license. ACKNOWLEDGMENTS We thank Janet Willment, Aberdeen Fungal Group, University of Aberdeen, for kindly providing the soluble Dectin-1-Fc reporter. All microscopy was performed with the assistance of the University of Aberdeen Core Microscopy & Histology Facility, and we thank the IFCC for their assistance with flow cytometry. We thank the Wellcome Trust for funding (080088, 086827, 075470, 099215, 097377, and 101873). E.R.B. and A.J.P.B. are funded by the European Research Council (ERC-2009-AdG-249793), and J.L. is funded by a Medical Research Council Clinical Training Fellowship.Peer reviewedPublisher PD

Primary health care in the South African context – medical students\' perspectives

Background Both the South African Department of Health and the University of Cape Town (UCT) have committed to the primary health care (PHC) approach, which is best captured in the Declaration of Alma Ata. If medical students are to be trained in the PHC approach, it is important that they not only have a good understanding of this approach, but are also aware of the social, economic and political context that they will be working in when they have qualified, so that they can develop realistic expectations of their careers as doctors. From research that was conducted at UCT, this article covers UCT medical students' views of health care in South Africa, including their perceptions of the applicability and implementation of the PHC approach for South Africa, and their perceptions of how the South African government features in issues of health and the PHC approach. Methods Mixed-methods were used, but this article will focus on the qualitative data gathered. One hundred and seventeen medical students (years one to four) were purposively selected to be involved in focus groups and interviews. These focus groups were conducted between February 2004 and March 2005. Results Students acknowledged that the state of health care in South Africa needs to change and showed an awareness of the role that South Africa's history of apartheid has played in the state of health care in these areas and the existence of inequity. They however did not agree on the applicability of the PHC approach to the South African situation. The PHC approach is seen not to be working in South Africa because of various obstacles to its implementation and success, such as disorganisation within the health system, and a lack of infrastructure, finances and resources. There seemed to be a general understanding amongst the students that they will have been trained in the PHC approach but then will be working within a system that has possibly not undergone similar changes. Students agreed on the important role of government in PHC, some maintaining that the government should be at the forefront of its implementation, but were generally dissatisfied with the role the South African government is currently playing in health care. Conclusion It is encouraging that students are generally aware of the reality of health care in South Africa and of the fact that more change needs to take place. However, it may be that many students who have a limited understanding of the impact that apartheid had on health care provision in South Africa, and this could then impact on students' perceptions of the applicability of the current PHC approach for South Africa. Students' views that the PHC approach has not been fully implemented in South Africa are a concern, as it is these types of views that are likely to cause students to lose confidence in the PHC approach, and will most likely widen the disjuncture between theory of the approach and the reality of its implementation. Regarding the political dynamics of the PHC approach, students do need to be aware of political factors that can impact on the success of this approach. Discussion around and research into the social, economic and political context of health care and medical education has particular relevance for South Africa, and it is vital that students' views on these issues are acknowledged so that areas for change can be identified and addressed. South African Family Practice Vol. 49 (10) 2007: pp. 6-1

Primary health care in the South African context - medical students' perspectives

Background Both the South African Department of Health and the University of Cape Town (UCT) have committed to the primary health care (PHC) approach, which is best captured in the Declaration of Alma Ata. If medical students are to be trained in the PHC approach, it is important that they not only have a good understanding of this approach, but are also aware of the social, economic and political context that they will be working in when they have qualified, so that they can develop realistic expectations of their careers as doctors. From research that was conducted at UCT, this article covers UCT medical students' views of health care in South Africa, including their perceptions of the applicability and implementation of the PHC approach for South Africa, and their perceptions of how the South African government features in issues of health and the PHC approach. Methods Mixed-methods were used, but this article will focus on the qualitative data gathered. One hundred and seventeen medical students (years one to four) were purposively selected to be involved in focus groups and interviews. These focus groups were conducted between February 2004 and March 2005. Results Students acknowledged that the state of health care in South Africa needs to change and showed an awareness of the role that South Africa's history of apartheid has played in the state of health care in these areas and the existence of inequity. They however did not agree on the applicability of the PHC approach to the South African situation. The PHC approach is seen not to be working in South Africa because of various obstacles to its implementation and success, such as disorganisation within the health system, and a lack of infrastructure, finances and resources. There seemed to be a general understanding amongst the students that they will have been trained in the PHC approach but then will be working within a system that has possibly not undergone similar changes. Students agreed on the important role of government in PHC, some maintaining that the government should be at the forefront of its implementation, but were generally dissatisfied with the role the South African government is currently playing in health care. Conclusion It is encouraging that students are generally aware of the reality of health care in South Africa and of the fact that more change needs to take place. However, it may be that many students who have a limited understanding of the impact that apartheid had on health care provision in South Africa, and this could then impact on students' perceptions of the applicability of the current PHC approach for South Africa. Students' views that the PHC approach has not been fully implemented in South Africa are a concern, as it is these types of views that are likely to cause students to lose confidence in the PHC approach, and will most likely widen the disjuncture between theory of the approach and the reality of its implementation. Regarding the political dynamics of the PHC approach, students do need to be aware of political factors that can impact on the success of this approach. Discussion around and research into the social, economic and political context of health care and medical education has particular relevance for South Africa, and it is vital that students' views on these issues are acknowledged so that areas for change can be identified and addressed