Micro-beam and pulsed laser beam techniques for the micro-fabrication of diamond surface and bulk structures

Micro-fabrication in diamond is involved in a wide set of emerging technologies, exploiting the exceptional characteristics of diamond for application in bio-physics, photonics, radiation detection. Micro ion-beam irradiation and pulsed laser irradiation are complementary techniques, which permit the implementation of complex geometries, by modification and functionalization of surface and/or bulk material, modifying the optical, electrical and mechanical characteristics of the material. In this article we summarize the work done in Florence (Italy) concerning ion beam and pulsed laser beam micro-fabrication in diamond.Comment: 14 pages, 5 figure

Towards truly simultaneous PIXE and RBS analysis of layered objects in cultural heritage

For a long time, RBS and PIXE techniques have been used in the field of cultural heritage. Although the complementarity of both techniques has long been acknowledged, its full potential has not been yet developed due to the lack of general purpose software tools for analysing the data from both techniques in a coherent way. In this work we provide an example of how the recent addition of PIXE to the set of techniques supported by the DataFurnace code can significantly change this situation. We present a case in which a non homogeneous sample (an oxidized metal from a photographic plate -heliography- made by Niepce in 1827) is analysed using RBS and PIXE in a straightforward and powerful way that can only be performed with a code that treats both techniques simultaneously as a part of one single and coherent analysis. The optimization capabilities of DataFurnace, allowed us to obtain the composition profiles for these samples in a very simple way.Comment: 9 pages, 3 figure

Termites and agricultural production in the Sahel: from enemy to friend?

Termites are an important component of agroecosystems, particularly in developing countries where they are an alternative to high priced inputs. Given the major problems in the Sahel of soil crusting and nutrient depletion, this paper shows that termites associated with proper management techniques can play a vital role. Termites contribute to the rehabilitation of crusted soils, i.e. by opening up voids on the sealed surface leading to improved infiltration capacity, and consequently improved water availability. It is recommended, however, that participatory on-farm research should be carried out on how to increase the contribution of termites towards soil management and to reduce the harmful effects

The role of termites and mulch in the rehabilitation of crusted Sahelian soils

During recent decades Sahelian soils have gone through various forms of degradation, the most spectacular one being the extension of bare and crusted soils. Mulch, when placed on a crusted and bare soil, triggers termite activity within a few months. Many burrows are opened through the sealed surface of the soil due to the borrowing activity of the termites. Throughout the soil profile, macropores with irregular shapes and with different diameter sizes are created. As a result of changes in soil structure, other soil physical properties are also improved. Soil resistance to cone penetration is reduced from a critical to a suitable level for vegetation growth. Bulk density is decreased and soil hydraulic conductivity is greatly increased. Water infiltration and drainage are also greatly improved. The combination of the increase of porosity and infiltration and the cover effect of mulch results in an increase of soil water availability in the soil profile during the growing season. Termite activity enhances decomposition of the mulch and hence nutrient release in the soil. The change of soil characteristics due to termite activity was enough to create conditions necessary for natural vegetation development and crop production on previously degraded bare soils in the Sahelo-Soudanian zone of northern Burkina Faso

Le phosphore limite-t-il la production intensive du riz dans la plaine de Bagré au Burkina Faso ?

Le phosphore (P) est un élément important dans la nutrition minérale du riz et dans l’élaboration du rendement paddy. Des essais soustractifs ont été conduits en milieu paysan dans la plaine rizicole de Bagré au cours de trois campagnes successives pour évaluer l’effet de l’application de P sur le rendement paddy. La capacité nutritive du sol en phosphore a varié entre 7 et 15 kg P ha-1. L’application de P a augmenté l’efficacité physiologique interne de P qui a varié entre 211 et 290 kg paddy kg-1 P (moyenne 249 kg kg-1). L’efficacité agronomique de P a été de 33,7 kg paddy kg–1 de P appliqué. L’augmentation de rendement due à l’application de phosphore a été de 19%. En moyenne, 70% du phosphore total absorbé est contenu dans les grains. L’évolution du rendement paddy indique que P est le second facteur limitant dans la plaine de Bagré après l’azote. L’application de P_engrais à une dose moyenne de 30 kg P ha-1 était suffisante pour compenser les pertes dues aux exportations. Le phosphore limite la production de riz à Bagré mais son application comme engrais contribue à améliorer les rendements paddy et à compenser les pertes de P du système.Mots clés : Capacité nutritive des sols, rizières, efficacité d’utilisation de nutriments, bilan minéral

Plasma microRNA Profiling of Obese Pregnant Women with/wothout Gestational Diabetes Mellitus

Introduction: Increasing Maternal Obesity (MO) worldwide is contributing to Gestational Diabetes Mellitus (GDM) occurrence, both leading to adverse short/long term maternal and offspring outcomes. miRNAs, as reversible epigenetic actors, are appealing targets for early therapy and intervention strategies. Limited studies explored their association in pregnancy, being also affected by a huge variability in methods, sample quality, subjects’ selection criteria and timing. We recently found an altered epigenetic profile in saliva of obese pregnancies. Here we perform plasma miRNA profiling of normoglycemic and diabetic obese vs lean pregnant women. Methods: Caucasian women with single term pregnancies (normal-weight controls, NW=7; obese without comorbidities, OB/GDM-=6; obese with GDM, OB/GDM+=6) were enrolled at elective cesarean section. Plasma expression of 179 miRNAs was analyzed by miRCURY LNA SybrGreen PCR. Bioinformatic analyses were performed with GeneGlobe software and predictive tools miTALOS v.2/miRPath v.3; statistics with SPSS v.27. Results: Except for maternal BMI and glycemia, the 3 groups did not differ in maternal, placental and neonatal characteristics. Plasma profiling revealed a number of differentially expressed miRNAs: 4 miRNAs (A) in OB/GDM- vs NW, 1 miRNA (B) in OB/GDM+ vs NW, and 14 miRNAs (C) OB/GDM+ vs OB/GDM- $$graphic_(Figure). The bioinformatic enrichment analysis found associations between these miRNAs and A) 35, B) 15, C) 38 different pathways, mostly involved in fatty acid and vitamin B6 metabolism, steroid homeostasis, amino acid (lysine, valine, leucine, isoleucine) biosynthesis/degradation, ECM-receptor interaction, thyroid hormones signalling, FoxO and insulin regulation, AMPK, mTOR, TGF-β and HIF-1 signalling. Conclusion: In this preliminary study, we profiled specific patterns of circulating miRNAs in the presence of MO and GDM. miRNAs with altered expression are involved in adipocyte differentiation and impaired glucose/lipid metabolism, and few of them have been proposed as metabolic regulators in GDM. Moreover, among the identified miRNAs-associated pathways, macro/micro nutrients metabolism and signaling, energy production, inflammation, oxidative status and insulin resistance may represent interlinked driving processes in MO and GDM pathogenesis. A larger sample size will help highlighting altered miRNAs and their role in the obesogenic and diabetic pregnancy context

Organic resources and earthworms affect phosphorus availability to sorghum after phosphate rock addition in semi-arid West Africa

A field experiment was laid out in Burkina Faso (West Africa) on an Eutric Cambisol to investigate the interaction of organic resource quality and phosphate rock on crop yield and to assess the contribution of earthworms (Millsonia inermis Michaelsen) to P availability after phosphate rock application. Organic resources of different quality were applied at a dose equivalent to 40 kg N ha¿1 with or without phosphate rock from Kodjari (Burkina Faso) at a dose equivalent to 25 kg P ha¿1, and were compared with control and single phosphate rock treatments in a factorial complete block design with four replicates. Sorghum (Sorghum bicolor L. Moench) variety SARIASSO 14 was grown. Sheep dung had the highest impact on earthworm casting intensity followed by maize straw. Combining organic resources with phosphate rock reduced earthworm casting activities compared to a single application of organic resources or phosphate rock. Addition of phosphate rock to maize straw reduced P availability in earthworm casts whereas combining sheep dung or compost with phosphate rock increased P availability. The contribution of earthworms to Kodjari phosphate rock solubilisation mainly occurred through their casts, as the available P content of casts was 4 times higher than that of the surrounding soi