South African Agricultural Research and Development: A Century of Change

The 20th Century saw substantive shifts in the structure of agriculture and agricultural production in South Africa. Farm size grew, farm numbers eventually declined, and production increasingly emphasized higher-valued commodities, notably a range of horticultural crops. The real gross value of agricultural output grew steadily (by 3.32 percent per year) from 1910-1981, but declined thereafter (by 0.21 percent per year from 1982-2008). These long-run sectoral changes provide a context to present and assess an entirely new data series on public agricultural R&D (and related regulatory and extension) spending and associated scientist trends. South African agricultural R&D has been affected by a series of major policy changes. These are also documented and discussed here, along with the associated institutional changes regarding the conduct and funding of public agricultural R&D in South Africa. We reveal a number of disturbing trends, including an effective flat lining of the long-run growth in total agricultural R&D spending that took hold in the 1970s, an erratic path of funding per scientist, and a loss of scientific personnel in recent decades. Moreover, South Africa has lost ground relative to its competitors in international commodity markets such as the United States and Australia in terms of the intensity of investment in agricultural R&D. These developments are likely to have long-term, and detrimental, consequences for the productivity performance and competiveness of South African agriculture. They deserve serious policy attention as the 21st Century unfolds, with a firm eye to the long-run given the long lags (often many decades) that typify the relationship between agricultural R&D spending and productivity growth.Research and Development/Tech Change/Emerging Technologies,

Married 6-year olds and other diseases of data

Presented at the National data integrity conference: enabling research: new challenges & opportunities held on May 7-8, 2015 at Colorado State University, Fort Collins, Colorado. Researchers, administrators and integrity officers are encountering new challenges regarding research data and integrity. This conference aims to provide attendees with both a high level understanding of these challenges and impart practical tools and skills to deal with them. Topics will include data reproducibility, validity, privacy, security, visualization, reuse, access, preservation, rights and management.Michael Kahn is the Associate Professor of Epidemiology, Department of Pediatrics, University of Colorado, Denver, Co-Director of the Colorado Clinical and Translational Sciences Institute (CCTSI) and Director of Clinical Informatics in the Department of Quality & Patient Safety. His research interests include real-time clinical decision support linked to clinical outcomes monitoring, clinical data warehouses for both operational and retrospective research support, integration of electronic medical records with prospective research, and translational research informatics for both T1 (bench to bedside) and T2 (bedside to community) translational settings. Prior to his current positions, Dr. Kahn was faculty in the Departments of Medicine, Computer Sciences, and Biomedical Engineering at Washington University School of Medicine in St Louis, Director of Advanced Clinical Systems at BJC Health Systems, and was in the commercial clinical trials software industry before returning to academics. Dr. Kahn has been a member of the board of directors of the American Medical Informatics Association, the Board of Scientific Counselors of the National Library of Medicine and the editorial boards of the Journal of the American Medical Informatics Association and the International Journal of Medical Informatics. He is a member of the American College of Medical Informatics.PowerPoint presentation given on May 8, 2015.Funding was provided by a contract from AcademyHealth. Additional support was provided by AHRQ 1R01HS019912-01 (Scalable PArtnering Network for CER: Across Lifespan, Conditions, and Settings), AHRQ 1R01HS019908 (Scalable Architecture for Federated Translational Inquiries Network), and NIH/NCRR Colorado CTSI Grant Number UL1 RR025780 (Colorado Clinical and Translational Sciences Institute)

The Visual Display of Temporal Information

The detection of temporal relationships among time-ordered patient data is an important, but difficult, clinical task. Large volumes of computer-stored clinical data offer the possibility of aiding in the early detection of subtle trends and states, but the presence of irrelevant data can obscure relevant findings and relationships. We present a formal system for representing complex temporal data as events on an abstract entity called a time limit. We define five time line operations, SLICE, FILTER, OVERLAY, NEW, and ADD. For each operation, we precisely define the operator\u27s effect on a time line, including exceptions and boundary conditions. IN addition to our time line, formalism, we describe an interactive environment designed specifically to help humans visualize temporal data. We have developed a database kernel and a graphical user interface that uses our time line formalism and operations to support temporal manipulations. Using our formal system and our visualization environment, we describe two issues in the display and manipulating of temporal data: (1) the temporal granularity problem, and (2) the calendar mapping problem

The Medical Informatics Group: Ongoing Research

Two current research projects within the Medical Informatics Group are described. The first, the Diabetes Data Management Project, has as its major goal the effective analysis, display, and summarization of information relevant to the care of insulin-dependent diabetics. These goals are achieved through the use of quantitative and qualitative modeling techniques, object-oriented graphical display methods, and natural language generation programs. The second research activity, the Hypertext Medical Handbook Project, emphasizes many aspects of electronic publishing and biomedical communication. In particular, the project explores machine-assisted information retrieval by combining user feedback with Bayesian inference networks

The Evolution of the Kinematics of Nebular Shells in Planetary Nebulae in the Milky Way Bulge

We study the line widths in the [\ion{O}{3}]$\lambda$5007 and H$\alpha$ lines for two groups of planetary nebulae in the Milky Way bulge based upon spectroscopy obtained at the Observatorio Astron\'omico Nacional in the Sierra San Pedro M\'artir (OAN-SPM) using the Manchester Echelle Spectrograph. The first sample includes objects early in their evolution, having high H$\beta$ luminosities, but [\ion{O}{3}]$\lambda 5007/\mathrm H\beta < 3$. The second sample comprises objects late in their evolution, with \ion{He}{2} $\lambda 4686/\mathrm H\beta > 0.5$. These planetary nebulae represent evolutionary phases preceeding and following those of the objects studied by Richer et al. (2008). Our sample of planetary nebulae with weak [\ion{O}{3}]$\lambda$5007 has a line width distribution similar to that of the expansion velocities of the envelopes of AGB stars, and shifted to systematically lower values as compared to the less evolved objects studied by Richer et al. (2008). The sample with strong \ion{He}{2} $\lambda 4686$ has a line width distribution indistinguishable from that of the more evolved objects from Richer et al. (2008), but a distribution in angular size that is systematically larger and so they are clearly more evolved. These data and those of Richer et al. (2008) form a homogeneous sample from a single Galactic population of planetary nebulae, from the earliest evolutionary stages until the cessation of nuclear burning in the central star. They confirm the long-standing predictions of hydrodynamical models of planetary nebulae, where the kinematics of the nebular shell are driven by the evolution of the central star.Comment: accepted for publication in the Astrophysical Journa

Glutathione in calf trabecularmeshwork and its relation to aqueous humor outflow facility,”

Previous studies have shown that sulfhydryl reagents can alter the facility of aqueous humor outflow but little is known about the sulfhydryl constituents of the aqueous outflow system or the effect of oxidants upon outflow facility. In the present study the concentration of glutathione (GSH) was measured in excised calf trabecular meshwork (TM) and found to be 0.40 n mol/g wet wt (0.027 n mol/mg protein). Oxidized glutathione was not detectable in the tissue. TM was found to have significant hexose monophosphate shunt activity as determined by measurement of the oxidation of 14C-1 and 14C-6-labeled glucose in tissue homogenates. The concentration of GSH in TM of enucleated calf eyes could be totally depleted by infusion of medium containing both diamide, which is an oxidant of GSH, and l,3bis(2-chlorethyl)-l-nitrosourea (BCNU), which is an inhibitor of the enzyme glutathione reductase. The depletion of GSH was found to have no effect on the facility of aqueous outflow. Experiments were also done in which normal and TM GSH-depleted eyes were perfused with medium containing H202. Exposure to H202 produced no effect on outflow facility in the normal eyes but caused a 33% decrease in facility in eyes with the GSH-depleted TM. The results indicate that GSH may not participate directly in regulating aqueous humor outflow but is able to protect TM against H202-induced oxidative damage that would otherwise lead to a decrease in outflow facility. Invest Ophthalmol Vis Sci 24:1283-1287, 1983 Anterior chamber perfusion studies have shown that the presence of sulfhydryl (-SH) reagents can alter the resistance to aqueous humor outflow, 1 &quot; 3 which suggests that thiols present in the trabecular meshwork (TM) may be involved in modulating aqueous humor outflow resistance. One thiol that may be involved in this process is glutathione (GSH), which has been found to be present in a number of ocular tissues 4 &quot; 6 but whose concentration has not been determined in TM. The present study was designed to determine the level of GSH present in calf TM and to investigate its function. In addition, since the hexose monophosphate shunt (HMPS) is an integral part of GSH metabolism, 7 the presence of this pathway in TM was also investigated. Since our studies to be reported demonstrated the presence of GSH in TM, it was of interest to deplete the level of the tripeptide in TM of perfused calf eyes and study the effect on aqueous outflow facility. For this purpose advantage was taken of diamide that has been shown to be a relatively specific oxidant of GSH 8 and of l,3bis(2-chloroethyl)-l-nitrosourea (BCNU), which is a specific inhibitor of the enzyme glutathione reductase. 9 Of special importance was the possible interaction of GSH in TM with H202, an oxidant that has been found to be a normal constituent of aqueous humor in at least three species including man. &quot; 12 Since aqueous humor is drained via the TM it is conceivable that oxidant stresses that exceed the capacity of TM for detoxification could result in cellular damage and subsequent alteration of aqueous humor outflow resistance. We report here on changes that occur in the facility of aqueous outflow in calf eyes when GSH-depleted TM is exposed to H202. Materials and Methods Calf eyes were obtained from Joseph T. Trelegan and Co. (Cambridge, MA). Shortly after the animals were killed by exsanguination the eyes were enucleated and placed in iced saline solution for transportation and use within 24 hrs. Lenses used in the study were from albino rabbits weighing between 1.8 and 2.2 kg

The Display and Manipulation of Temporal Information

Because medical data have complex temporal features, special techniques are required for storing, retrieving, and displaying clinical data from electronic databases. One significant problem caused by the temporal nature of medical data has been called the temporal granularity problem. The temporal granularity problem is said to occur when the set of facts relevant to a specific problem changes as the time scale changes. We argue that what is needed to deal with changes in the relevant time scale are temporal granularity heuristics. One heuristic that we have explored is that, for any level of problem abstraction, and for each type of data item in the record, there exists an optimal level of temporal abstraction. We describe an implemented database kernel and a graphical user interface that have features designed specially to support this temporal granularity heuristic. The basis for our solution is the use of temporal abstraction and temporal granularity. This heuristic encodes the relevant behavior of each type of event at different levels of temporal granularity. In doing so, we can define a specific behavior for each type of data as the level of abstraction changes

Model-Based Interpretation of Time-Varying Medical Data

Temporal concepts are critical is medical therapy-planning. If given early enough, specific therapeutic choices may abort or suppress evolving undesired changes in a patient’s clinical status. Effective medical decision making demands recognition and interpretation of complex temporal changes that permeate the medical record. This paper presents a methodology for representing and using medical knowledge about temporal relationships to infer the presence of clinically relevant events, and describes a program, called TOPAZ, that uses this methodology to generate a narrative summary of such events. A unique feature of TOPAZ is the use of numeric and symbolic modeling techniques to perform temporal reasoning tasks that would be difficult to encode and perform using only one modeling methodology

Response to "Toward Unified Satellite Climatology of Aerosol Properties. 3. MODIS Versus MISR Versus AERONET"

A recent paper by Mishchenko et al. compares near-coincident MISR, MODIS, and AERONET aerosol optical depth (AOD) products, and reports much poorer agreement than that obtained by the instrument teams and others. We trace the reasons for the discrepancies primarily to differences in (1) the treatment of outliers, (2) the application of absolute vs. relative criteria for testing agreement, and (3) the ways in which seasonally varying spatial distributions of coincident retrievals are taken into account

Visualizing Exotic Orbital Texture in the Single-Layer Mott Insulator 1T-TaSe2

Mott insulating behavior is induced by strong electron correlation and can lead to exotic states of matter such as unconventional superconductivity and quantum spin liquids. Recent advances in van der Waals material synthesis enable the exploration of novel Mott systems in the two-dimensional limit. Here we report characterization of the local electronic properties of single- and few-layer 1T-TaSe2 via spatial- and momentum-resolved spectroscopy involving scanning tunneling microscopy and angle-resolved photoemission. Our combined experimental and theoretical study indicates that electron correlation induces a robust Mott insulator state in single-layer 1T-TaSe2 that is accompanied by novel orbital texture. Inclusion of interlayer coupling weakens the insulating phase in 1T-TaSe2, as seen by strong reduction of its energy gap and quenching of its correlation-driven orbital texture in bilayer and trilayer 1T-TaSe2. Our results establish single-layer 1T-TaSe2 as a useful new platform for investigating strong correlation physics in two dimensions