Search results for " changes"
showing 10 items of 824 documents
Quantifying the contribution of nitrification and denitrification to the nitrous oxide flux using 15N tracers.
2006
8 pages; International audience; Microbial transformations of nitrification and denitrification are the main sources of nitrous oxide (N2O) from soils. Relative contributions of both processes to N2O emissions were estimated on an agricultural soil using 15N isotope tracers (15NH4+ or 15NO3-), for a 10-day batch experiment. Under unsaturated and saturated conditions, both processes were significantly involved in N2O production. Under unsaturated conditions, 60% of N-N2O came from nitrification, while denitrification contributed around 85-90% under saturated conditions. Estimated nitrification rates were not significantly different whatever the soil moisture content, whereas the proportion o…
Climate change and cyclic predator-prey population dynamics in the high Arctic.
2009
The high Arctic has the world's simplest terrestrial vertebrate predator–prey community, with the collared lemming being the single main prey of four predators, the snowy owl, the Arctic fox, the long-tailed skua, and the stoat. Using a 20-year-long time series of population densities for the five species and a dynamic model that has been previously parameterized for northeast Greenland, we analyzed the population and community level consequences of the ongoing and predicted climate change. Species' responses to climate change are complex, because in addition to the direct effects of climate change, which vary depending on species' life histories, species are also affected indirectly due to…
Zur R�ntgenidentifizierung unbekannter Leichen bei fortgeschrittenen postmortalen Ver�nderungen
1989
Die postmortalen Veranderungen an einer Wasserleiche und an einer Brandleiche waren so weit fortgeschritten, das die ublichen Identifizierungsmethoden versagen musten. Vergleichende rontgenologische Untersuchungen ermoglichten jedoch den sicheren Nachweis der Identitat. Der Erfolg beruhte auf der individuellen Variabilitat des Skelettsystems und seiner hohen Widerstandsfahigkeit gegenuber intravitalen und postmortalen Einflussen. Neben der hohen Aussagekraft sind einfache, schnelle Handhabung sowie Dokumentation — ohne Beeintrachtigung der Obduktion — weitere Vorteile der Rontgenidentifizierung. Die vorgestellten Falle zeigen zudem, das auch zehn Jahre alte intravitale Vergleichsbilder zur …
Project Management in the Port Development Project in Latvia
2016
Paper analyse case study of performance and compliance audit in the port development project in Latvia. Author has participated in the audit process evaluating project management application practical approach in the project implemented by the Riga Freeport Authority and co-funded by the Cohesion Fund “Development of Infrastructure on Krievu Island for the Transfer of Port Activities from the City Centre”. Despite the mass media reports that the Riga Freeport Authority has successfully completed the project, only the construction phase of the project has been completed. During the following two years the stevedore activity must be transferred to the newly built port infrastructure on Krievu…
Reliability of automated optical determination of capillary refill time
2021
The present study is devoted to assessment of automated optical capillary refill time determination by custom developed optoelectronic device prototype. Study comprised fifteen healthy volunteers; To induce capillary refill time changes the hand position challenge was utilized. During rest conditions slight inter-subject variation was observed: T90 (0.75±0.27 s), TSTB (2.20±0.58 s) and temperature at the measurement site (32.21±1.87 Co), however during hand position challenge results were more consistent. Rising hand substantially increased, while lowering slightly decreased capillary refill time. We conclude that automated determination of refill time have high clinical potential, however …
Monitoring soil volume wetness in heterogeneous soils by electrical resistivity. A field-based pedotransfer function.: A field-based pedotransfer fun…
2014
11 pages; International audience; Modern irrigation techniques require accurate, rapid, cost-effective, spatial measurement of soil moisture. Electrical Resistivity Tomography (ERT) meets most of these requirements, but needs to be calibrated for each use because it is very sensitive to differences in soil characteristics. In this study, a pedotransfer function approach is used to remove the need for site-specific calibration, allowing ERT to be used directly to measure soil moisture. The study site was a hillslope vineyard, where eight calcaric-cambisol soil profiles were identified. From 2012 to 2013, 23 000 soil volume wetness measurements were acquired by Time Domain Reflectometry, and …
Isolation and characterisation of Nocardioides sp. SP12, an atrazine-degrading bacterial strain possessing the gene trzN from bulk- and maize rhizosp…
2003
International audience; We report the characterisation of Nocardioides sp. SP12, an atrazine-degrading bacteria isolated from atrazine-treated bulk- and maize rhizosphere soil. Based on 16S rDNA alignment, strain SP12 showed close phylogenic relationships with Nocardioides sp. C157 and Nocardioides simplex. Internal transcribed spacer (ITS) sequences of strain SP12 were longer than those of other Nocardioides sp. and present Ala- and Ile-tRNA unlike Actinomycetales. Nocardioides sp. SP12 presents a novel atrazine catabolic pathway combining trzN with atzB and atzC. Atrazine biodegradation ends in a metabolite that co-eluted in HPLC with cyanuric acid. This metabolite shows an absorption spe…
Interannual persistence effects in vegetation dynamics of semi-arid Africa
2005
[1] Over 15 years of Normalized Difference Vegetation Index (NDVI) data from the Advanced Very High Resolution Radiometers (AVHRR) are used to study the response of vegetation activity to rainfall in three semi-arid regions of Africa. The relationships between annual NDVI and annual precipitation (PPT) time series are examined using statistical approaches (simple and partial correlations, linear multiple regressions). It appears that annual NDVI highly depends on PPT of the concurrent year and the previous year. An analysis of particularly dry and wet years enables to better diagnose two distinct responses of vegetation activity to rainfall. The “recovery” effect represents the difficulty o…
Reliability and effectiveness of Ellenberg’s indices in checking flora and vegetation changes induced by climatic variations
2001
Two methods are proposed to assess the significance of time-spanned local variations of Ellenberg’s indicator values in floristic and phytosociological data sets respectively. Both methods are based on frequencies and averages of the indicator values within and among data sets. Main goal of proposed methods is to determine the threshold above which the observed variations are to be considered significant. In order to relate the observed floristic variations to recent climatic changes, attention was focused on the Ellenberg’s indices dealing with the main climatic variables: heliophany, temperature and precipitation. Study-cases from Zannone Island (Pontine Archipelago, Mediterranean region)…
Long-term changes in the water temperature of rivers in Latvia
2016
Abstract The study describes the trends of monthly mean water temperature (from May to October) and the annual maximum water temperature of the rivers in Latvia during the time period from 1945 to 2000. The results demonstrated that the mean water temperatures during the monitoring period from May to October were higher in the largest rivers (from 13.6 °C to 16.1 °C) compared to those in the smallest rivers (from 11.5 °C to 15.7 °C). Similar patterns were seen for the maximum water temperature: in large rivers from 22.9 °C to 25.7 °C, and in small rivers from 20.8 °C to 25.8 °C. Generally, lower water temperatures occurred in rivers with a high groundwater inflow rate, for example, in river…