Влияние комбинированного применения гипоксическо-гиперкапнического стимула и методов аппаратной физиотерапии на иммунную систему больных хроническим обструктивным заболеванием легких

Изучено влияние на иммунную систему больных хроническим обструктивным заболеванием легких комбинации гипоксическо−гиперкапнического стимула и разных методов аппаратной физиотерапии. Установлено, что в целом комбинированное применение разработанной методики уменьшает дефицит Т−звена и частично восстанавливает работу гуморального компонента иммунитета.The influence of combined use of hypoxic−hypercapnic stimulus and different methods of apparatus physiotherapy on the immune system of the patients with chronic obstructive pulmonary disease was investigated. Combined application of the developed technique was established to diminish T−link deficiency and to restore partially the work of humoral immunity

Temporal variability of mineral dust in southern Tunisia : analysis of 2 years of PM10 concentration, aerosol optical depth, and meteorology monitoring

International audienceThe south of Tunisia is a region very prone to wind erosion. During the last decades, changes in soil management have led to an increase in wind erosion. In February 2013, a ground-based station dedicated to the monitoring of mineral dust (that can be seen in this region as a proxy of the erosion of soils by wind) was installed at the Institut des Régions Arides (IRA) of Médenine (Tunisia) to document the temporal variability of mineral dust concentrations. This station allows continuous measurements of surface PM10 concentration (TEOM™), aerosol optical depth (CIMEL sunphotometer), and total atmospheric deposition of insoluble dust (CARAGA automatic sampler). The simultaneous monitoring of meteorological parameters (wind speed and direction, relative humidity, air temperature, atmospheric pressure, and precipitations) allows to analyse the factors controlling the variations of mineral dust concentration from the sub-daily to the annual scale. The results from the two first years of measurements of PM10 concentration are presented and discussed. In average on year 2014, PM10 concentration is 56 µg/m3. However, mineral dust concentration highly varies throughout the year: very high PM10 concentrations (up to 1,000 µg/m3 in daily mean) are frequently observed during wintertime and springtime, hardly ever in summer. These episodes of high PM10 concentration (when daily average PM10 concentration is higher than 240 µg/m3) sometimes last several days. By combining local meteorological data, air-masses trajectories, sunphotometer measurements, and satellite imagery, the part of the high PM10 concentration due to local emissions and those linked to an advection of dusty air masses by medium and long range transport from the Sahara desert is quantified

Impact of compost, vermicompost and biochar on soil fertility, maize yield and soil erosion in Northern Vietnam : a three year mesocosm experiment

Compost, vermicompost and biochar amendments are thought to improve soil quality and plant yield. However, little is known about their long-term impact on crop yield and the environment in tropical agro-ecosystems. In this study we investigated the effect of organic amendments (buffalo manure, compost and verrnicompost) and biochar (applied alone or with vermicompost) on plant yield, soil fertility, soil erosion and water dynamics in a degraded Acrisol in Vietnam. Maize growth and yield, as well as weed growth, were examined for three years in terrestrial mesocosms under natural rainfall. Maize yield and growth showed high inter-annual variability depending on the organic amendment. Vermicompost improved maize growth and yield but its effect was rather small and was only significant when water availability was limited (year 2). This suggests that vermicompost could be a promising substrate for improving the resistance of agrosystems to water stress. When the vermicompost biochar mixture was applied, further growth and yield improvements were recorded in some cases. When applied alone, biochar had a positive influence on maize yield and growth, thus confirming its interest for improving long-term soil productivity. All organic amendments reduced water runoff, soil detachment and NH4+ and NO3- transfer to water. These effects were more significant with vermicompost than with buffalo manure and compost, highlighting that the beneficial influence of vermicompost is not limited to its influence on plant yield. In addition, this study showed for the first time that the combination of vermicompost and biochar may not only improve plant productivity but also reduce the negative impact of agriculture on water quality

Drought effect on teak tree (Tectona grandis) roots on carbon inputs and water uptake in a deep soil of northern Laos

Fine deep roots are organs of foremost functional importance and bring about evidence that teak tree extracts deep water during critically dry periods. The presence of measurable amounts of deep fine roots should be taken into account when quantifying long-term carbon storage

Utilization of Near Infrared Reflectance Spectroscopy (NIRS) to quantify the impact of earthworms on soil and carbon erosion in steep slope ecosystem: a study case in northern Vietnam

This work focuses on a new approach to quantify the effects of above-ground earthworm's activity on soil erosion in steep slope ecosystems such as in Northern Vietnam. In these areas and in many others in the world, soil erosion becomes a major issue while the factors that determine it are still misunderstood. Earthworm's activity is believed to influence soil erosion rate, but we are still unable to precisely quantify their contribution to soil erosion. In this study, we used Near Infrared Reflectance Spectroscopy (NIRS) to quantify the proportion of soil aggregate in eroded soil coming from earthworm activity. This was done by generating NIRS signatures corresponding to different soil surface aggregates (above-ground soil casts produced by earthworms vs. surrounding topsoil). In order to test the proposed approach, we compared the NIRS-signature of eroded soil sediments to those of earthworms' casts and of the surrounding soils. Our results strongly supported that NIRS spectra might be used as "fingerprints? to identify the origin of soil aggregates. Although earthworms are generally assumed to play a favorable role in promoting soil fertility and ecosystem services, this method shows that cast aggregates constitute about 36 and 77% of sediments in two tropical plantations, Paspalum atratumand Panicum maximum plantations, respectively. In light with these results, we estimated that earthworms led to an annual loss of 3.3 and 15.8 kg of carbon ha-1 yr-1, respectively in P. atratum and P. maximum agroecosystems

Earthworms accelerate soil porosity turnover under watering conditions

Endogeic earthworms significantly modify soil aggregation and porosity, which in turn control water flow in soil. This study aimed to determine how the earthworm casting activity influences soil porosity and its dynamics. The main hypothesis was that the deposition of belowground water-stable casts increases soil porosity and its water stability. First we quantified cast production by the endogeic earthworm species Metaphire posthuma under laboratory conditions for 15 days. Secondly, casts and the bulk soil were analysed for structural stability to water and were packed in soil and subjected to wetting under various conditions and energy levels. The shape and size of pores were measured by image analysis. Almost all casts (98%) were produced belowground. M. posthuma produced approximately five times its own weight per day. Casts were depleted in C and were more easily disaggregated by water than the bulk soil. Although casts initially led to larger soil porosity (on average 50%), their structure was unstable. As a consequence, water inputs led to a faster decrease in soil porosity in the presence of casts. Large pores in between casts were rapidly replaced by small elongated and rounded pores. These results suggest that cast lifespan and associated porosity are of primary importance in the regulation of soil porosity turnover and the ecological functions that are under its control. Our findings suggest that in the field, the low stability of casts is likely to lead to a rapid compaction of the soil after rainfall events. However, high levels of cast production may prevent soil porosity from being broken down. Soil structural porosity thus depends on the balance between the production and degradation of casts. Improvements to the soil structure will occur when the former predominates

Differences in the Efficiency of the Vertical Transfer of Windblown Sediment over Different Ploughed Surfaces during Wind Erosion Events

International audienceAirborne sediment fluxes were measured in southern Tunisia on two experimental plots tilled with a moldboard and a tiller plough, respectively, during five wind erosion events of different intensities. The sediment fluxes were sampled on both plots using a mast equipped with seven sand traps positioned between ≈10 and 120 cm height. The windblown sediment fluxes in the 0–100 cm layer were about eight times higher on the plot tilled using the tiller plough compared to the plot tilled using the moldboard plough due to different efficiencies in the trapping of the saltating particles in the furrow, depending on the ridges characteristics. On both plots, sediment fluxes of larger particles were depleted in the sediment samplers compared to the proportions measured in the soil from which they were derived. When examining the sediment flux in the 30–100 cm layer, we observed that the efficiency of the vertical transfer was about twice higher on the moldboard plot than on the tiller one. This implies that a higher fraction of the sediment mobilized by wind can be transported over long distances in the case of a surface ploughed with a moldboard. This result could reduce in part the benefit of using the moldboard instead of the tiller plough regarding soil loss by wind erosion