•The research aimed at quantifying N2O fluxes from Eucalyptus grandis plantations.•The research aimed at identifying factors explaining emission variability.•Emission rates and annual N2O emissions ...were low in all evaluated treatments.•NO3-N level in soil was the variable that best explained N2O-N emissions.
Nitrous oxide has a key effect on global climate development and 53% of N2O total annual emissions are related to fluxes from the soil. Land use and soil characteristics affect N2O emissions. There are not enough assessments in Argentina to quantify N2O emissions from commercial forest plantations. This research aimed at quantifying N2O fluxes from Eucalyptus grandis plantations and at identifying factors explaining emission variability. The study was carried out in Gualeguaychú, Entre Ríos Province, Argentina (33°1′17″S, 58° 13′37″W) on Eucalyptus grandis plantations in four different situations: at two ages (2–4 yr and 8–10 yr), on two contrasting texture soils (coarse and fine), and on a medium-textured sodic soil in a natural forest (shrubland). Greenhouse gas emissions (N2O and CO2) were measured 12 times between August 2016 and October 2017. Emission rates and annual N2O emissions were low in all evaluated treatments (average emission rate: 2.62 µg N2O-N m−2h−1, and average annual emission: 0.226 kg N2O-N ha−1 year−1). These rates are considerably lower than those of agricultural situations in the same region. This can be explained by the null use of nitrogen fertilization and by the absence of atmospheric nitrogen- fixing crops in forestry plantations. The use under natural forest showed the highest cumulative annual emissions (0.698 kg N2O-N ha−1 year−1) possibly because of its woody leguminous species composition and its higher soil water content. N2O emissions in fine 2-4y, coarse 2-4y, and in coarse 8-10y were in average 0.0896 kg N2O-N ha−1 year−1 with no statistically differences between them. The fine 8-10y N2O emissions did not differ from the natural forest neither from the other treatments (0.261 kg N2O-N ha−1 year−1). Soils with higher clay content showed a trend toward higher N2O emissions than sandy soils. NO3-N level in soil was the variable that best explained N2O-N emissions (p < 0.001). Since nitrate content and CO2 emission were the variables most associated with nitrous emissions, it can be hypothesized that in clay soils greater emissions can be originated by higher nitrification as a result of their higher organic matter content or due to a denitrification provoked by the depletion of oxygen in a high consumption respiration process, and poor oxygen renewal caused by the increased amount of micro-aggregates and pores.
Abstract
Species diversity and frequency index of bivalve mollusks’ of unionid family are researched within river basins of Ukraine. The largest frequency index of mussels is identified in the ...Prypiat and Desna basins (84 and 79% respectively), then (as the indicator declines) – the Dnieper and Severskiy Donets basins (74 and 67%), the Southern Bug and Danube (47 and 46%), the Southern and Western Bug (47 and 28%), the Crimea (17%). No mollusks were found in the Azov basin at all. Most often (33%) there were found groups consisting of only three unpretentious species (
Unio pictorum, U. tumidus, Anodonta anatina
). In general, settlements from one to three species make up 70% of all researched collecting sites. Settlements formed by four species are identified only in 23% of habitats. Only 6% of settlements consisted of five aboriginal species and about 1% – of six. Locations where six species lived together were identified only in the Danube and Prypiat basins. There are no settlements of five species in the Western Bug and Desna basins at all, and there are not any even four species settlements in the Crimea. The obtained data can be used for organizing environmental activities and assessing water environment quality
Tailored, specialty optical fibres, made of complex glasses, called collectively as a non-telecommunications or instrumentation family, serve for various optical wave transformations for particular ...functional purposes and optical signal processing, rather than for long distance lossless and dispersionless, undistorted transmission. Research work on these fibres started during the late seventies of the last century in ITME/Warsaw and in Białystok University of Technology at the Faculty of Electrical Engineering. The initiator of this research at Glass Works Białystok 39 and Białystok University of Technology 4 was, then a very young engineer, Jan Dorosz. Over 35 years of development of the technological team, under his skilful management, resulted in a top laboratory which today does research at the cutting edge of the photonics science. The Białystok Optical Fibre Technology Laboratory (OFTL) is now a pearl in the crown of his Alma Mater. The paper opens this special issue of the PAS Bulletin on Technical Sciences, devoted to professor Jan Dorosz, and shows some of the developments in the area of optical fibre photonics, which were carried out at his active laboratory.
Microbial properties may help to provide an integrated view of changes in soil functioning associated with soil management or soil status. The fatty acid profiles of membrane phospholipids (PLFA) can ...give the composition of ecophysiological groups of soil microbial communities, while catabolic response profiles (CRP) estimate the heterotrophic functional diversity in soils, both relevant to the understanding of the role of micro‐organisms in the functioning of the soil. The objectives of this study were (i) to evaluate the CRP and PLFA as microbial tools to characterize changes in soil functioning and (ii) clarify the relation among these microbial measurements, with other physical, chemical and biochemical soil properties. We compare the same soil subjected to different managements and degrees of erosion. An undisturbed soil (UN), an old pasture soil (OP) and soils under continuous cultivation (NT) with four different depth of A horizon: 25 cm (NT 25), 23 cm (NT 23), 19 cm (NT 19) and 14 cm (NT 14) were tested. Substrate‐induced respiration of most substrates diminished when cropping pressure increased (UN > OP > NT), and soil catabolic evenness, as a diversity index, decreased by increasing production pressure and soil erosion. The correlation found among most of the measured physical, chemical and biochemical soil properties with the catabolic evenness showed the potential of this measurement to provide an integrated view of soil functioning. The PLFA analysis showed that the composition of microbial community denoting a partial recovery after 10 yr under grazed grassland. The stress indicators showed that farming practices increased microbial stress with the highest values found in the most eroded soils.
An apparatus to search for optical flashes in the sky is described. It has been optimized for optical counterparts of gamma ray bursts (GRB). It consists of 2×16 cameras covering all the sky. The sky ...is monitored continuously and the data are analyzed on-line. The apparatus has self-triggering capability and can react to external triggers with negative delay. The prototype with two cameras has been installed at Las Campanas (Chile) and is operational from July 2004. The paper presents the general idea of the experiment and describes the apparatus in detail. The performance of the prototype is briefly reviewed and perspectives for the future are outlined.
MCORD - MPD Cosmic Ray Detector a new features Bielewicz, M.; Milewicz-Zalewska, M.; Grodzicka-Kobylka, M. ...
EPJ Web of Conferences,
2019, Letnik:
204
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
The main detector system at the Nuclotron-based Ion Collider fAcility (NICA) located in Dubna, Russia is the Multi-Purpose Detector (MPD). For better calibration reason, the MPD needs an additional ...trigger system for an off-beam calibration of MPD sub-detectors and for rejection (veto) of cosmic muons. The system should also be useful for practical astrophysics observations of cosmic showers. The consortium NICA-PL group defines goals and basic assumptions for the MPD Cosmic Ray Detector (MCORD). This article describes the conceptual design and simulation plans of the MCORD detector based on plastic scintillators with SiPM photodetectors and electronic digital system based on the MicroTCA crate.
•Cardiac modulation of intercostal and abdominal EMG was found in anesthetized dogs.•Modest cardiac modulation of expiratory bulbospinal neuron discharges was also found.•The bulbospinal modulation ...was not sufficient to explain the EMG modulation.•Thoracic and abdominal muscle spindles may contribute to cardiac interoception.
Previous analyses of recordings of alpha motoneuron discharges from branches of the intercostal and abdominal nerves in anesthetized cats under neuromuscular blockade demonstrated modulation with the cardiac cycle. This modulation was interpreted as evidence that thoracic somatosensory afferents, most likely muscle spindles, provide a signal to the CNS that could contribute to cardiac interoception. Here, two aspects of these observations have been extended. First, new measurements of thoracic and abdominal EMG activity in spontaneously breathing dogs show that a very similar modulation exists in these rather different circumstances. Second, further analysis of the cat recordings shows that cardiac modulation of the discharges of bulbospinal neurons that transmit the expiratory drive to thoracic motoneurons is weak and of an inappropriate time-course to be a contributor to the effect seen in the motoneurons.
In persons with spinal cord injury, lower thoracic low-frequency spinal cord stimulation (LF-SCS; 50 Hz, 15 mA) is a useful method to restore an effective cough. Unfortunately, the ...high-stimulus-amplitude requirements and potential activation of pain fibers significantly limit this application in persons with intact sensation. In this study, the mechanism of the expiratory muscle activation, via high-frequency SCS (HF-SCS; 500 Hz, 1 mA) was evaluated in dogs. In group 1, the effects of electrode placement on airway pressure generation (P) was evaluated. Maximal P occurred at the T9-T10 level with progressive decrements in P at more rostral and caudal levels for both LF-SCS and HF-SCS. In group 2, electromyographic (EMG) latencies of internal intercostal muscle (II) activation were evaluated before and after spinal root section and during direct motor root stimulation. Onset time of II EMG activity during HF-SCS was significantly longer (3.84 ± 1.16 ms) than obtained during direct motor root activation (1.61 ± 0.10 ms). In group 3, P and external oblique (EO) EMG activity, before and after sequential spinal section at the T11-T12 level, were evaluated. Bilateral dorsal column section significantly reduced EO EMG activity below the section and resulted in a substantial fall in P. Subsequent lateral funiculi section completely abolished those activities and resulted in further reductions in P. We conclude that 1) activation of the expiratory muscles via HF-SCS is dependent entirely on synaptic spinal cord pathways, and 2) HF-SCS at the T9 level produces a comparable level of muscle activation with that achieved with LF-SCS but with much lower stimulus amplitudes. NEW & NOTEWORTHY The findings in the present study suggest that lower thoracic high-frequency spinal cord stimulation with low stimulus currents results in sufficient activation of the expiratory muscles via spinal circuitry to produce large positive airway pressures sufficient to generate an effective cough mechanism. This method, therefore, may be applied in patient populations with intact sensation such as stroke and amyotrophic lateral sclerosis to restore an effective cough.
In this paper, the use of Stevia rebaudiana Bertoni, perennial indigenous native plant from the tropical region of South America, is presented, with a brief outlook on the history and uses of the ...wild plant by Guarani Indians, the crop domestication, and the authorization of its use as a natural sweetener in food and beverages. Other aspects considered are natural glycosides and physicochemical properties for food processing, nutritional information, medicinal properties, Stevia market and household uses. The future of this plant is promising but more research is needed to ensure the use of leaves and steviosides, and to study cultivation practices in various regions of the world.
Displacement damage (DD) caused by fast neutrons in unbiased Gallium Arsenide (GaAs) light emitting diodes (LED) resulted in a reduction of the light output. On the other hand, a similar type of LED ...irradiated with gamma rays from a 60Co source up to a dose level in excess of 1.0 kGy (1.0 × 105 rad) was found to show no significant drop of the light emission. This phenomenon was used to develop a low cost passive fluence monitor and kinetic energy released per unit mass dosemeter for accelerator-produced neutrons. These LED-dosemeters were used to assess the integrated fluence of photoneutrons, which were contaminated with a strong bremsstrahlung gamma-background generated by the 730 MeV superconducting electron linac driving the free electron laser in Hamburg (FLASH) at Deutsches Elektronen-Synchrotron. The applications of GaAs LED as a routine neutron fluence monitor and DD precursor for the electronic components located in high-energy accelerator environment are highlighted.
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