The geoid in Kenya

The definition of geoidal undulations is given and after summarizing the methods of determination of the geoid, computed geoidal undulations by some of the methods for several points in Kenya are compared to the results obtained by the satellite gravimetric solutions. Results from astrogeodetic levelling and satellite altimetry show some reasonable agreement with the satellite gravimetric geoids while results by Doppler satellite positioning indicate that good agreement can be obtained if the orthometric heights for the points are adjusted to a uniform system

Protective Alumina Coatings by Low Temperature Metalorganic Chemical Vapour Deposition

Alumina thin films were processed from aluminium tri-iso-propoxide in a horizontal, with N2 as a carrier gas, occasional addition of water in the gas phase, deposition temperature in the range 350-700°C, total pressure 0.67 kPa (2 kPa when water was used). The films do not diffract X-ray when prepared below 700°C. At 700°C, they start to crystallize as γ-alumina. EDS, EPMA, ERDA, RBS, FTIR and TGA revealed that films prepared in the range 350- 415°C, without water in the gas phase, have an overall composition Al2O3-x(OH)2x, with x tending to 0 with increasing temperature. Al2O3 is obtained above 415°C. When water is added in the vapour phase, the film composition is Al2O3, even below 415°C. Coatings deposited in these conditions show promising protection properties

The Effect of Electronic Cigarette User Modifications and E-liquid Adulteration on the Particle Size Profile of an Aerosolized Product

Electronic cigarettes (e-cigarettes) are an alternate nicotine delivery system that generate a condensation aerosol to be inhaled by the user. The size of the droplets formed in the aerosol can vary and contributes to drug deposition and ultimate bioavailability in the lung. The growing popularity of e-cigarette products has caused an increase in internet sources promoting the use of drugs other than nicotine (DOTNs) in e-cigarettes. The purpose of this study was to determine the effect of various e-cigarette and e-liquid modifications, such as coil resistance, battery voltage, and glycol and drug formulation, on the aerosol particle size. E-liquids containing 12 mg/mL nicotine prepared in glycol compositions of 100% propylene glycol (PG), 100% vegetable glycerin (VG), or 50:50 PG:VG were aerosolized at three voltages and three coil resistances. Methamphetamine and methadone e-liquids were prepared at 60 mg/mL in 50:50 PG:VG and all e-liquids were aerosolized onto a 10 stage Micro-Orifice Uniform Deposit Impactor. Glycol deposition correlated with drug deposition, and the majority of particles centered between 0.172–0.5 μm in diameter, representing pulmonary deposition. The 100% PG e-liquid produced the largest aerosol particles and the 100% VG and 50:50 PG:VG e-liquids produced ultra-fine particles \u3c0.3 μm. The presence of ultrafine particles indicates that drugs can be aerosolized and reach the pulmonary alveolar regions, highlighting a potential for abuse and risk of overdose with DOTNs aerosolized in an e-cigarette system

Historia de las creencias y ceremonias religiosas de todos los pueblos

Es reimp. de la ed. de París

Interactions entre plantes de couverture, mauvaises herbes et cultures : quelle est l'importance de l'allélopathie ?

Des essais réalisés en serre ont mis en évidence le potentiel allélopathique des exSudats racinaires et des produits de décomposition de mulch de plantes de couverture utilisées en zone tropicale. On cherche d'une part à dissocier les effets allélopothiques de la compétition et d'autre part à estimer l'effet allélopathique en conditions proches du réel, sans concentration artificielle des substances émises. Les résultats montrent que les effets dépendent de la plante émettrice et sont sélectifs, certaines plantes étant très sensibles, d'autres moins. Les comportements différenciés ont des conséquences sur le choix des plantes de couverture. Les réponses sont dépendantes des conditions de culture et on émet l'hypothèse que le régime hydrique joue au champ un rôle prépondérant sur l'expression d'un effet allélopathique. (Résumé d'auteur

Integrating Al with NiO nano honeycomb to realize an energetic material on silicon substrate

Nano energetic materials offer improved performance in energy release, ignition, and mechanical properties compared to their bulk or micro counterparts. In this study, the authors propose an approach to synthesize an Al/NiO based nano energetic material which is fully compatible with a microsystem. A two-dimensional NiO nano honeycomb is first realized by thermal oxidation of a Ni thin film deposited onto a silicon substrate by thermal evaporation. Then the NiO nano honeycomb is integrated with an Al that is deposited by thermal evaporation to realize an Al/NiO based nano energetic material. This approach has several advantages over previous investigations, such as lower ignition temperature, enhanced interfacial contact area, reduced impurities and Al oxidation, tailored dimensions, and easier integration into a microsystem to realize functional devices. The synthesized Al/NiO based nano energetic material is characterized by scanning electron microscopy, X-ray diffraction, differential thermal analysis, and differential scanning calorimetry

Simultaneous Observations of the Chromosphere with TRACE and SUMER

Using mainly the 1600 angstrom continuum channel, and also the 1216 angstrom Lyman-alpha channel (which includes some UV continuum and C IV emission), aboard the TRACE satellite, we observed the complete lifetime of a transient, bright chromospheric loop. Simultaneous observations with the SUMER instrument aboard the SOHO spacecraft revealed interesting material velocities through the Doppler effect existing above the chromospheric loop imaged with TRACE, possibly corresponding to extended non-visible loops, or the base of an X-ray jet.Comment: 14 pages, 10 figures, accepted by Solar Physic

The isolation and culture of endothelial colony forming cells from human and rat lungs

Blood vessels are crucial for the normal development, lifelong repair and homeostasis of tissues. Recently, vascular progenitor cell–driven 'postnatal vasculogenesis' has been suggested as an important mechanism that contributes to new blood vessel formation and organ repair. Among several described progenitor cell types that contribute to blood vessel formation, endothelial colony-forming cells (ECFCs) have received widespread attention as lineage-specific 'true' vascular progenitors. Here we describe a protocol for the isolation of pulmonary microvascular ECFCs from human and rat lung tissue. Our technique takes advantage of an earlier protocol for the isolation of circulating ECFCs from the mononuclear cellular fraction of peripheral blood. We adapted the earlier protocol to isolate resident ECFCs from the distal lung tissue. After enzymatic dispersion of rat or human lung samples into a cellular suspension, CD31-expressing cells are positively selected using magnetic-activated cell sorting and plated in endothelial-specific growth conditions. The colonies arising after 1–2 weeks in culture are carefully separated and expanded to yield pure ECFC cultures after a further 2–3 weeks. The resulting cells demonstrate the defining characteristics of ECFCs such as (i) 'cobblestone' morphology of cultured cell monolayers; (ii) acetylated low-density lipoprotein uptake and Ulex europaeus lectin binding; (iii) tube-like network formation in Matrigel; (iv) expression of endothelial cell–specific surface markers and the absence of hematopoietic or myeloid surface antigens; (v) self-renewal potential displayed by the most proliferative cells; and (vi) contribution to de novo vessel formation in an in vivo mouse implant model. Assuming typical initial cell adhesion and proliferation rates, the entire procedure can be completed within 4 weeks. Isolation and culture of lung vascular ECFCs will allow assessment of the functional state of these cells in experimental and human lung diseases, providing newer insights into their pathophysiological mechanisms

Effect of Aloe Vera wastes on physico-chemical properties and microbiological activity in soils

The aim of the present study was to explore the potential for using aloe vera wastes as amendment for soil to improve its fertility. Soil was exposed to four concentrations of aloin (rich in HAP) for 0, 7, 14 and 28 days. Physico-chemical parameters were analyzed: soil Ph, organic matter (OM), nitrogen, phosphorus, and cation exchange capacity (CEC). The activity of seven enzymes implicated in the C, N and S cycles were measured. Microbial Biomass was determined by the method of substrate induced respiration. BiologEcoplates (Biolog Inc., Hayward, CA) were used to estimate soil microbial functional diversity. Our findings suggested a decrease on phosphorus and nitrogen content and an increase on CEC after aloin addition. Also, a decrease on microbial biomass and enzymes activities was observed, except for FDA. Ecoplates results demonstrate a decrease on microbial activities depending on the incubation time. Moreover, our results indicated that bacterial communities of the tested soils have more affinity to consume substrates as Amino acids and polymers. Our results should be carefully considered in view of the agriculture waists reuse for a sustainable agricultur