THE FUTURE OF WILDFLOWER RESEARCH AND DEVELOPMENT IN SOUTH AFRICA - THE LACHENALIA CASE STUDY

This paper reports the socio-economic impact of the lachenalia research program of the ARCRoodeplaat Vegetable and Ornamental Plant Institute (ARC-Roodeplaat) over the period 1965-2010. Data were collected from researchers, the local propagator and the market agent in Holland, using guidelines and questionnaires. A financial and economic analysis were conducted. The results of both were negative, unless increased productivity, early entry into all potential markets and a decreased research gestation period were assumed. Additional impacts were qualitatively assessed. The program contributed to employment creation, the preservation of biodiversity, capacity building and beneficial institutional linkages. The management information generated by the study was used in planning and priority setting at the institute.Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

Rigorous results on superconducting ground states for attractive extended Hubbard models

We show that the exact ground state for a class of extended Hubbard models including bond-charge, exchange, and pair-hopping terms, is the Yang "eta-paired" state for any non-vanishing value of the pair-hopping amplitude, at least when the on-site Coulomb interaction is attractive enough and the remaining physical parameters satisfy a single constraint. The ground state is thus rigorously superconducting. Our result holds on a bipartite lattice in any dimension, at any band filling, and for arbitrary electron hopping.Comment: 12 page

Dying Dyons Don't Count

The dyonic 1/4-BPS states in 4D string theory with N=4 spacetime supersymmetry are counted by a Siegel modular form. The pole structure of the modular form leads to a contour dependence in the counting formula obscuring its duality invariance. We exhibit the relation between this ambiguity and the (dis-)appearance of bound states of 1/2-BPS configurations. Using this insight we propose a precise moduli-dependent contour prescription for the counting formula. We then show that the degeneracies are duality-invariant and are correctly adjusted at the walls of marginal stability to account for the (dis-)appearance of the two-centered bound states. Especially, for large black holes none of these bound states exists at the attractor point and none of these ambiguous poles contributes to the counting formula. Using this fact we also propose a second, moduli-independent contour which counts the "immortal dyons" that are stable everywhere.Comment: 27 pages, 2 figures; one minus sign correcte

Nonperturbative Effects from the Resummation of Perturbation Theory

Using the general argument in Borel resummation of perturbation theory that links the divergent perturbation theory to the nonperturbative effect we argue that the nonperturbative effect associated with the perturbation theory should have a branch cut only along the positive real axis in the complex coupling plane. The component in the weak coupling expansion of the nonperturbative amplitude, which usually includes the leading term in the weak coupling expansion, that gives rise to the branch cut can be calculated in principle from the perturbation theory combined with some exactly calculable properties of the nonperturbative effect. The realization of this mechanism is demonstrated in the double well potential and the two-dimensional O(N) nonlinear sigma model. In these models the leading term in weak coupling of the nonperturbative effect can be obtained with good accuracy from the first terms of the perturbation theory. Applying this mechanism to the infrared renormalon induced nonperturbative effect in QCD, we suggest some of the QCD condensate effects can be calculated in principle from the perturbation theory.Comment: 21 Pages, 1 Figure; To appear in Phys Rev

Triple combination of insulin glargine, sitagliptin and metformin in type 2 diabetes : the EASIE post-hoc analysis and extension trial

Q3Q1Aim We examined the effects of adding glargine to metformin–sitagliptin (MS + G) or sitagliptin to metformin–glargine (MG + S) therapy in type 2 diabetic persons uncontrolled after 24-week MS or MG dual therapy. Methods Subjects with A1c ≥ 7% on MS or MG treatment were respectively given glargine (0.2 U/kg starting dose) or sitagliptin (100 mg daily) for 12 weeks. The primary endpoint was number of subjects attaining A1c goal defined as < 7%. Results After receiving 24-week MS or MG dual therapy in the original EASIE Study, 42% (104/248) on MS and 68% (152/224) on MG attained A1c < 7% (p < 0.0001). The reduction in A1c was negatively associated with baseline fasting blood glucose (FBG) only in the MG group. Reduction in A1c was not related to baseline postprandial blood glucose (PPBG) in either the MG or MS group. Amongst 194 eligible patients, 57.7% (n = 111) entered the 12-week extension trial [MS + G:74/131, 57.3%; MG + S:37/63, 58.7%) with 55 (51.9%) subjects attaining goal [MS + G:59.2%; MG + S:37.1%] at week 12. The final insulin dosage was similar in both groups [MS + G: 0.46 U/kg; MG + S: 0.45 U/kg] with a higher rate of hypoglycemia in the MG + S (6.5 events/patient-year) than the MS + G group (3.2 events/patient-year), although neither group had severe hypoglycemia. Conclusion In metformin-treated type 2 diabetes patients, high fasting BG predicted greater A1c reductions with the addition of glargine, but not with sitagliptin. In subjects uncontrolled with 6-month dual therapy of MS or MG, 50% attained A1c < 7% with triple therapy of MS + G or MG + S in 12 weeks. The increased rate of hypoglycemia with MG + S (but not with MS + G) underlines the need to take measures to avoid the hypoglycemia

NOx and O3 above a tropical rainforest: an analysis with a global and box model

A cross-platform field campaign, OP3, was conducted in the state of Sabah in Malaysian Borneo between April and July of 2008. Among the suite of observations recorded, the campaign included measurements of NOx and O3 – crucial outputs of any model chemistry mechanism. We describe the measurements of these species made from both the ground site and aircraft. We then use the output from two resolutions of the chemistry transport model p-TOMCAT to illustrate the ability of a global model chemical mechanism to capture the chemistry at the rainforest site. The basic model performance is good for NOx and poor for ozone. A box model containing the same chemical mechanism is used to explore the results of the global model in more depth and make comparisons between the two. Without some parameterization of the nighttime boundary layer – free troposphere mixing (i.e. the use of a dilution parameter), the box model does not reproduce the observations, pointing to the importance of adequately representing physical processes for comparisons with surface measurements. We conclude with a discussion of box model budget calculations of chemical reaction fluxes, deposition and mixing, and compare these results to output from p-TOMCAT. These show the same chemical mechanism behaves similarly in both models, but that emissions and advection play particularly strong roles in influencing the comparison to surface measurements

EDN1 Lys198Asn is Associated with Diabetic Retinopathy in Type 2 Diabetes

Purpose: We tested the hypothesis that genetic variants in vasoactive and angiogenic factors regulating the retina vasculature contribute to the development of diabetic retinopathy (DR). Methods: A case-control study was performed to study the genetic association between DR and polymorphic variants of EDN1 (Lys198Asn), LTA (IVS1–80C>A, IVS1–206G>C, IVS1–252>G), eNOS (Glu298Asp), and ITGA2 (BgI II) in a Chinese population with type 2 diabetes mellitus. A well defined population with type 2 diabetes, consisting of 127 controls and 216 DR patients, was recruited. Results: A higher frequency of the Asn/Asn genotype of EDN1 was found in individuals with at least 10 years of diabetes and no retinopathy (controls) compared with DR patients with any duration of diabetes (DR: 2.3%; control: 11.0%; p=0.0002). The Asn allele was also more frequent in controls than DR patients (DR: 16.4%; control: 29.5%; p=0.007). Multiple logistic regression analysis showed that the Asn/Asn genotype was the factor most significantly associated with reduced risk of DR (odds ratio=0.19; 95% CI: 0.07-0.53; p=0.002) and with late onset of diabetes (Asn/Asn: 59 years; Lys/Lys + Lys/Asn: 53 years; p=0.02). Moreover, the Lys/Lys genotype was more common among patients with nonproliferative (75.7%) than proliferative DR (56.9%; p=0.008). The distributions of Lys198Asn alleles in hypertension did not differ from normotensive subjects. No associations between DR and polymorphisms of LTA, eNOS, or ITGA2 were detected, and there were no detectable gene-gene or gene-environmental interactions among the polymorphisms.Conclusions The Asn/Asn genotype of EDN1 was associated with a reduced risk of DR and with delayed onset of type 2 diabetes

SL(∞,R)SL(\infty,R) Symmetry of W∞W_\infty Gravity

Two-dimensional gravity in the light-cone gauge was shown by Polyakov to exhibit an underlying $SL(2,R)$ Kac-Moody symmetry, which may be used to express the energy-momentum tensor for the metric component $h_{++}$ in terms of the $SL(2,R)$ currents {\it via}\ the Sugawara construction. We review some recent results which show that in a similar manner, $W_\infty$ and $W_{1+\infty}$ gravities have underlying $SL(\infty,R)$ and $GL(\infty,R)$ Kac-Moody symmetries respectively.Comment: 10 pages (Talk presented at the Trieste Summer School in High-Energy Physics, August 1991

An in-situ cell for characterization of solids by soft X-rayabsorption

An in-situ cell using ''lab-on-a-chip'' technologies has been designed and tested for characterization of catalysts and environmental materials using soft X-ray absorption spectroscopy and spectromicroscopy at photon energies above 250 eV. The sample compartment is 1.0 mm in diameter with a gas path length of 0.8 mm to minimize X-ray absorption in the gas phase. The sample compartment can be heated to 533 K by an Al resistive heater and gas flows up to 5.0 cm{sup 3} min{sup -1} can be supplied to the sample compartment through microchannels. The performance of the cell was tested by acquiring Cu L{sub 3}-edge XANES data during the reduction and oxidation of a silica-supported Cu catalyst using the beam line 11.0.2 Scanning Transmission X-ray Microscope (STXM) at the Advanced Light Source of LBNL. Two-dimensional images of individual catalyst particles were recorded at photon energies between 926 eV and 937 eV, the energy range in which the Cu(II) and Cu(I) L{sub 3} absorption edges are observed. Oxidation state specific images of the catalyst clearly show the disappearance of Cu(II) species during the exposure of the oxidized sample to 4% CO in He while increasing the temperature from 308 K to 473 K. Reoxidation restores the intensity of the image associated with Cu(II). L-edge XANES spectra obtained from stacks of STXM images show that with increasing temperature the Cu(II) peak intensity decreases as the Cu(I) peak intensity increases