L Mando - Academia.edu (original) (raw)

Papers by L Mando

Journal of Physics-condensed Matter, 2004

Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment, 1995

Geoderma, 1996

In northern Burkina Faso (West Africa), a study was undertaken to explore the possibilities of re... more In northern Burkina Faso (West Africa), a study was undertaken to explore the possibilities of restoring the infiltration capacity of crusted soils through the stimulation of termite activity. Treatments consisted of the application of a mulch of a mixture of wood and straw without insecticides (resulting in “termite plots”) and the application of the same mulch and an insecticide (Dursban with chloropyrifos as the active ingredient) to prevent termite activity (resulting in “non-termite plots”). Three rainfall simulations of 60 minutes duration with an intensity of 50 mm/h at an interval of 24 hours between the first and the second and 72 hours between the second and third simulation were applied, to study the effect of consecutive showers on termite-modified soil characteristics. Cumulative infiltration amounts, final infiltration rates, soil water content and porosity were larger and bulk density was smaller on termite plots as compared to non-termite plots. This suggests that termites may be an important agent in soil-crust control and in the improvement of soil physical properties in Sahelian ecosystems.

International Clinical Psychopharmacology, 2001

A previous report suggested that 5 weeks of continued treatment with 20 mg of fluoxetine was appr... more A previous report suggested that 5 weeks of continued treatment with 20 mg of fluoxetine was approximately as effective as double-blind titration to a dose of 60 mg in patients who had failed to respond to 3 weeks of initial treatment at 20 mg. The current study was undertaken to evaluate whether 150 mg of sertraline was any more effective than 50 mg in treating depressed patients who were non-responders at 3 weeks. Ninety-one outpatients with DSM-IV major depressive disorder who had a 17-item Hamilton Depression Rating Scale (HAM-D) score &amp;gt; or = 18 were treated with open label sertraline for 3 weeks. Patients who did not achieve remission (defined as 17-item HAM-D total score &amp;lt; or = 8 by week 3) were then randomized to 5 more weeks of double-blind treatment with either 50 mg of sertraline or immediate titration to 150 mg of sertraline. Efficacy was assessed at each visit with the HAM-D, Clinical Global Impressions (CGI)-severity and improvement scale, and the Hopkins Symptom Checklist. There were no significant between-group differences in clinical or demographic features at baseline for the three treatment groups. After 3 weeks of open-label treatment, 16 patients were not randomized, of whom 11 (69%) met responder criteria. The remaining patients were randomized, double-blind, to 50 mg of sertraline (n = 37; HAM-D = 19.2 +/- 5.0) or 150 mg of sertraline (n = 38; HAM-D = 18.4 +/- 5.0). PROC-Mixed analyses found no significant difference in slopes for any outcome measure when comparing 50 mg and 150 mg sertraline treatment groups. At week 8 (LOCF), the overall remission rate (HAM-D &amp;lt; or = 8) for 3-week non-responders was 40%, with no statistically significant between-group difference for the 50 mg versus 150 mg doses of sertraline (P &amp;gt; 0.10). A completer analysis yielded similar results. Adverse events were mostly mild on both doses of sertraline and led to few treatment discontinuations. The results suggest that for most patients continued treatment with 50 mg dose of sertraline yields a rate of antidepressant response that is comparable to what is achieved by dose escalation from 50 mg to 150 mg of sertraline after 3 weeks of treatment. While some patients clearly benefit from higher doses, the results of the current study are consistent with the lack of any evidence for a dose-response curve with sertraline in the treatment of depression.

Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, 1994

The external beam facility installed at the KN-3000 accelerator in Florence, formerly used for PI... more The external beam facility installed at the KN-3000 accelerator in Florence, formerly used for PIXE measurements, has been exploited also for RBS analysis. A particle detector has been placed at 135° in a setup structure which also includes the two Si(Li) detectors simultaneously used for PIXE. A helium flow is kept in front of the particle detector and of the one used for low-energy X rays, as well as in the region between the beam exit window and the target; no chamber is used for gas containment, in order to allow us the most complete freedom for target size and for its handling. Gas leaks upwards are limited by a soft rubber lid which is kept in contact with the target itself. Helium saturation of the volume in front of the target and of the detectors is attained with a gas flow of less than 1 ℓ . All the “user-friendly” features of the existing PIXE facility have been maintained: in particular, video-monitoring the sample with a remotely controlled camera, checking beam position with laser aiming and sampling beam current with a rotating chopper are still possible and easy to perform. Particular care has been taken of particle-detector mounting and detection geometry in order to obtain the best possible energy resolution. The present setup gives an overall system resolution of about 28 keV FWHM, when bombarding ultra thin targets with 1.5 to 3 MeV protons. Further improvements are in progress. Preliminary applications have been performed on samples which may not be placed under vacuum; in particular, combined PIXE-RBS measurements have been done to clarify some problems connected with ancient inks analysis (thickness determination, penetration within the underlying paper or parchment), and to check composition of thin standards evaporated onto polymeric supports.

Agriculture Ecosystems & Environment, 2001

Lack of adequate nutrient supply and poor soil structure are the principal constraints to crop pr... more Lack of adequate nutrient supply and poor soil structure are the principal constraints to crop production under low input agriculture systems of West Africa. Experiments at two sites (Mediga and Yimtenga) were conducted in Burkina Faso to assess the impact of compost on improving crop production and soil properties. In the first experiment, compost was applied at the rate of 0 and 10 Mg ha−1 in Mediga on a Ferric Lixisol, and 5 and 0 Mg ha−1 on a Ferric-gleyic Lixisol in Yimtenga. A second experiment was conducted in Yimtenga to assess the role of compost in mitigating the effect of delay in sowing on crop performance. 0 and 5 Mg ha−1 compost plots were sown within the normal period for sowing sorghum (Sorghum bicolor L. Moench) and with a delay of 1 month. A randomised block design was used with four replications for the two experiments.Semi-structured interviews were used to study socio-economic issues of compost technology. No significant difference in soil organic matter content was found between treatments receiving compost and no-compost. However, compost application increased soil cation exchange capacity (CEC) from 4 to 6 cmol kg−1. Soil pH was also increased by the compost application. Sorghum yield tripled on the 10 Mg ha−1 compost plots and increased by 45% on the 5 Mg ha−1 compost plots, compared to no-compost plots. Compost application mitigated the negative effects of a delay in sowing. The study showed that farmers were aware of the role of compost in sustaining yield and improving soil quality. However, lack of equipment and adequate organic material for making compost, land tenure and the intensive labour required for making compost are major constraints for the adoption of compost technology. It was concluded that compost application could contribute to increase food availability in the Sahel and therefore, efforts should be made to alleviate the socio-economic constraints to the adoption of compost technology.

Soil Use and Management, 2003

Abstract. In the semiarid regions of sub-Saharan Africa, fertilizer recovery and nutrient release... more Abstract. In the semiarid regions of sub-Saharan Africa, fertilizer recovery and nutrient release from organic sources are often moisture limited. Moreover, in these regions runoff brings about large nutrient losses from fertilizer or organic inputs. This study was conducted in the north sudanian climate zone of Burkina Faso (annual rainfall 800 mm, PET 2000 mm yr−1). We assessed the combined and interactive effects of two types of permeable barriers (stone rows and grass strips of Andropogon gayanus Kunth cv. Bisquamulatus (Hochst.) Hack.) and organic or mineral sources of nitrogen on erosion control and sorghum yield. The field experiment (Ferric Lixisol, 1.5% slope) was carried out during three rainy seasons and consisted of 2 replications of 9 treatments, in which the barriers were put along contours and combined with compost, manure and fertilizer nitrogen (N). Compared with the control plots, the average reduction in runoff was 59% in plots with barriers alone, but reached 67% in plots with barriers + mineral N and 84% in plots with barriers + organic N. On average, stone rows reduced soil erosion more than grass strips (66% versus 51%). Stone rows or grass strips without N input did not induce a significant increase of sorghum production. Supplying compost or manure in combination with stone rows or grass strips increased sorghum grain yield by about 142%, compared with a 65% increase due to mineral fertilizers. The sorghum grain yields at 1 m upslope from the grass strips were less than those 17 m from the grass strips. As stones do not compete with plants, the opposite trend was observed with stone rows. We conclude that for these nutrient depleted soils, permeable barriers improve nutrient use efficiency and therefore crop production. However, grass strips must be managed to alleviate shade and other negative effects of the bunds on adjacent crops.

Transplantation Proceedings, 2007