8,748 research outputs found
CORRUPTION AND OBSTACLES FOR CONDUCTING BUSINESS IN FORMER FRENCH WEST AFRICA
This study examines the extent of corruption and obstacles to conducting business in some former French West Africa countries.
Methodology: This study uses business owner’s and mangers perceptions about the use of gifts or informal payments and obstacles to conducting business in five African countries. Data comes from the World Bank Institute and the European Bank for Reconstruction and Development’s Business Environment and Economic Performance study. Data from Benin, Burkina Faso, Niger, Senegal, and Togo were examined. Univariate general linear analysis was used to discover statistical differences between factors by country.
Main Findings: Results show Senegalese managers and owners perceived the lowest obstacles to conducting business among the five countries. Togo business managers and owners are slightly less positive about obstacles they face in their businesses. Businesses in the five countries on average pay about eight percent of their annual sales as gifts/informal payments.
Limitations: The study uses data that is about ten years old. The political and economic environment may have changed in these countries since data collection.
Social Implications: The significant level of obstacles business faces in these countries may significantly reduce foreign direct investment in these countries. Electricity is an obstacle in most of these countries reducing the ability if not the interest in conducting business.
Originality/Novelty of the Study: The French strategy in this region for three hundred years was to rule through the military not the development of economic systems. The results of this strategy may still be apparent in the number and degree of obstacles facing business only 50 years after independence
Endophytic Agrobacterium in crown gall-resistant and -susceptible Vitis genotypes
Several methods were used to study endophytic colonization of Vitis genotypes by Agrobacterium vitis (AV). AV was seldom detected except at inoculated sites, indicating little systemic movement of the bacterium under the conditions of these experiments. AV populations at inoculated sites were evaluated for 10 months following inoculation of crown gall-resistant and -susceptible genotypes. Two months after inoculation, V. amurensis selections had significantly smaller populations than V. vinifera (Cabernet Sauvignon) or V. riparia x V. rupestris (C3309). All crown gall-resistant genotypes had significantly lower populations than Cabernet Sauvignon 10 months after inoculation. Examination of vines one year after inoculation indicated that AV populations were much higher at inoculated sites when crown galls developed. However, even when no galls were apparent, Cabernet Sauvignon had significantly higher AV populations than V. amurensis 689 (6-fold higher) and C3309 (70-fold higher). Crown gall-resistant genotypes appear to support lower populations of AV than the crow gall-susceptible Cabernet Sauvignon. Freezing followed by a two-day incubation significantly increased recovery of Agrobacterium using vascular fluid displacement in naturally-infected and artifically-inoculated vines and therefore increased the sensitivity of indexing for AV in grapevines
Direct Determination of the Kinetics of Oxygen Diffusion to the Photocytes of a Bioluminescent Elaterid Larva, Measurement of Gas- and Aqueous-Phase Diffusional Barriers and Modelling of Oxygen Supply
We describe the development and use of a direct kinetic technique to determine the time taken for oxygen to diffuse from the external environment into the light-producing cells (photocytes) in the prothorax of bioluminescent larvae of Pyrearinus termitilluminans. This was achieved by measuring the time course of the pseudoflash induced through sequential anoxia followed by normoxia. We have also determined the separate times taken for this oxygen diffusion in gaseous and tissue (predominantly aqueous) phases by using helium and nitrogen as the carrier gas. Of the total time taken for diffusion, that in the gas phase required 613+/-136 ms (mean +/- s.e. m., N=5) whilst that in the aqueous phase required 1313+/-187 ms. These values imply pathlengths of diffusion in the gaseous and aqueous phases of 4.80x10(-)(3)+/-0.53x10(-)(3) and 8. 89x10(-)(5)+/-0.61x10(-)(5 )m, respectively. In addition, the pathlength of gas-phase diffusion was used to derive a parameter relating to the tortuosity of the tracheal system. These values, together with those obtained upon bioluminescent oxygen consumption, have been used to model oxygen supply to the photocyte. From these studies, it would also appear that the modulation of tracheolar fluid levels might be a significant mechanism of control of tissue oxygen levels in at least some insects
Transformation of crown gall resistant and susceptible Vitis genotypes by Agrobacterium vitis
Transformation of crown gall-susceptible and -resistant Vitis genotypes by Agrobacterium vitis strain CG49 was studied using uidA (GUS) in the p35SGUSINT construct. When greenhouse-grown material propagated through tissue culture was inoculated with CG49(p35SGUSINT) in vitro, the highly crown gall-susceptible V. vinifera Cabernet Sauvignon displayed GUS activity on 53 % of inoculated explants vs. 5 % for the resistant V. amurensis and 0 % for the resistant Couderc 3309. Response of Cabernet Sauvignon suggested a strong effect of shoot polarity on transformation. Inoculation of basal vs. apical explant surface in Cabernet Sauvignon indicated transformation in 88 % of basal inoculated explants with no transformation from apical inoculation. Basal inoculations indicated no transformation of V. amurensis and transformation in 10 % of Couderc 3309 explants. Inoculation of intact plants with CG49(p35SGUSINT) produced GUS-positive sites at 56 % of inoculated sites in Cabernet Sauvignon, 10 % of V. amurensis inoculated sites and 9 % of Couderc 3309 inoculated sites. Resistance to crown gall in these genotypes appears to be due to reduced susceptibility to transformation by A. vitis rather than post-transformation phenomena. These studies were complicated by production of GUS-positive spots from in vitro inoculations using wild-type CG49. Resident microorganisms producing b-glucuronidase may proliferate after tissue degradation by A. vitis-induced cell disruption. Use of in vitro internodal explants from tissue culture-propagated vines greatly reduced GUS expression from control CG49 inoculations and these were readily distinguished (by appearance and location) from GUS-positive spots resulting from transformation with uidA
X-ray photoemission spectroscopy determination of the InN/yttria stabilized cubic-zirconia valence band offset
The valence band offset of wurtzite InN(0001)/yttria stabilized cubic-zirconia (YSZ)(111) heterojunctions is determined by x-ray photoemission spectroscopy to be 1.19±0.17 eV giving a conduction band offset of 3.06±0.20 eV. Consequently, a type-I heterojunction forms between InN and YSZ in the straddling arrangement. The low lattice mismatch and high band offsets suggest potential for use of YSZ as a gate dielectric in high-frequency InN-based electronic devices
Control of gene-stacked canola by alternative herbicides
Non-Peer ReviewedUnintentional herbicide resistance gene stacking in canola may alter the sensitivity of volunteers
to herbicides of alternative modes of action commonly used for their control. Greenhouse
experiments were conducted to investigate the dose response of three single herbicide-resistant
(HR) cultivars (glyphosate, glufosinate, imidazolinone), one non-HR cultivar, and seven multiple
(double or triple) HR experimental lines treated at the two- to three-leaf stage to 2,4-D (amine
and ester), MCPA ester, and metribuzin; and of one non-HR and four HR cultivars (glyphosate,
glufosinate, imidazolinone, bromoxynil) to 2,4-D amine applied at two growth stages (two to
three, and five to six leaves). All canola cultivars or lines treated at the two- to three-leaf stage
responded similarly to increasing doses of the three herbicides. At the five- to six-leaf stage,
however, the bromoxynil HR cultivar was less sensitive to 2,4-D than the other cultivars. The
results of this study suggest that canola with multiple herbicide resistance traits does not differ
from cultivars that are non-HR or single HR in its sensitivity to herbicides commonly used to
control volunteers. All volunteers, whether non-HR, single HR, or multiple HR, should be
treated when plants are most sensitive to herbicides (two- to four-leaf stage) to reduce their
interference against crops and their perpetuation of gene flow
Measurement of Oxygen Partial Pressure, its Control During Hypoxia and Hyperoxia, and its Effect upon Light Emission in a Bioluminescent Elaterid Larva
This study investigates the respiratory physiology of bioluminescent larvae of Pyrearinus termitilluminans in relation to their tolerance to hypoxia and hyperoxia and to the supply of oxygen for bioluminescence. The partial pressure of oxygen (P(O2)) was measured within the bioluminescent prothorax by in vivo electron paramagnetic resonance (EPR) oximetry following acclimation of larvae to hypoxic, normoxic and hyperoxic (normobaric) atmospheres and during periods of bioluminescence (during normoxia). The P(O2) in the prothorax during exposure to an external P(O2) of 15.2, 160 and 760 mmHg was 10.3+/-2.6, 134+/-0.9 and 725+/-73 mmHg respectively (mean +/- s.d., N=5; 1 mmHg=0.1333 kPa). Oxygen supply to the larvae via gas exchange through the spiracles, measured by determining the rate of water loss, was also studied in the above atmospheres and was found not to be dependent upon P(O2). The data indicated that there is little to no active control of extracellular tissue P(O2) within the prothorax of these larvae. The reduction in prothorax P(O2) observed during either attack-response-provoked bioluminescence or sustained feeding-related bioluminescence in a normoxic atmosphere was variable, but fell within the range 10-25 mmHg. The effect of hypoxic atmospheres on bioluminescence was measured to estimate the intracellular P(O2) within the photocytes of the prothorax. Above a threshold value of 50-80 mmHg, bioluminescence was unaffected by P(O2). Below this threshold, an approximately linear relationship between P(O2) and bioluminescence was observed. Taken together with the extracellular P(O2) measurements, this suggests that control of P(O2) within the photocyte may occur. This work establishes that EPR oximetry is a valuable technique for long-term measurement of tissue P(O2) in insects and can provide valuable insights into their respiratory physiology. It also raises questions regarding the hypothesis that bioluminescence can have a significant antioxidative effect by reduction of prothorax P(O2 )through oxygen consumption
Middle Atmosphere Response to Different Descriptions of the 11-Year Solar Cycle in Spectral Irradiance in a Chemistry-Climate Model
The 11-year solar cycle in solar spectral irradiance (SSI) inferred from measurements by the SOlar Radiation & Climate Experiment (SORCE) suggests a much larger variation in the ultraviolet than previously accepted. We present middle atmosphere ozone and temperature responses to the solar cycles in SORCE SSI and the ubiquitous Naval Research Laboratory (NRL) SSI reconstruction using the Goddard Earth Observing System chemistry-climate model (GEOS CCM). The results are largely consistent with other recent modeling studies. The modeled ozone response is positive throughout the stratosphere and lower mesosphere using the NRL SSI, while the SORCE SSI produces a response that is larger in the lower stratosphere but out of phase with respect to total solar irradiance above 45 km. The modeled responses in total ozone are similar to those derived from satellite and ground-based measurements, 3-6 Dobson Units per 100 units of 10.7-cm radio flux (F10.7) in the tropics. The peak zonal mean tropical temperature response 50 using the SORCE SSI is nearly 2 K per 100 units 3 times larger than the simulation using the NRL SSI. The GEOS CCM and the Goddard Space Flight Center (GSFC) 2-D coupled model are used to examine how the SSI solar cycle affects the atmosphere through direct solar heating and photolysis processes individually. Middle atmosphere ozone is affected almost entirely through photolysis, whereas the solar cycle in temperature is caused both through direct heating and photolysis feedbacks, processes that are mostly linearly separable. Further, the net ozone response results from the balance of ozone production at wavelengths less than 242 nm and destruction at longer wavelengths, coincidentally corresponding to the wavelength regimes of the SOLar STellar Irradiance Comparison Experiment (SOLSTICE) and Spectral Irradiance Monitor (SIM) on SORCE, respectively. A higher wavelength-resolution analysis of the spectral response could allow for a better prediction of the atmospheric response to arbitrary SSI variations
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