Search results for "mass [rho(770)]"

The Critical Mass of Wireless Communications

2011

The aim of this chapter is to identify and analyze the timing and level of critical mass in the development of market penetration for wireless communications. The authors assume that critical mass is fulfilled at the point when the acceleration of the diffusion process is at its maximum. In practice, this point is determined by estimating the diffusion function and calculating the second derivative with respect to time. The diffusion of mobile subscription is modelled using the Bass diffusion model. The penetration levels and points of time of critical mass of 209 countries or areas of the world are identified and subsequently subjected to regression analysis against population and economic…

Soil microbial and microfaunal communities and organic matter quality in reindeer winter and summer ranges in Finnish subarctic mountain birch forests

2008

Abstract Reindeer husbandry has significant influences on the aboveground plant communities and the structure of the mountain birch forests in the Fennoscandian subarctic. We investigated how the reindeer-mediated aboveground changes affect soil microbial and microfaunal communities and enzymatic activities. We hypothesized that in areas with intensive summer browsing by reindeer, the carbon flow to belowground is reduced, but the carbon substances are more readily degradable. This is likely to influence both the abundance and the trophic structure of microbial and microfaunal communities. However, despite large differences in the vegetation, the reindeer ranges did not differ in the amount…

Responses of microbial-feeding nematodes to organic matter distribution and predation in experimental soil habitat

2001

Abstract Soils are spatially heterogeneous environments, a condition which is likely to affect the structure and function of soil food webs. To study the influence of soil organic matter distribution on decomposer food webs, we established microcosms that contained either: (1) large patches of initially sterile humus-litter mixture placed within sterile sand matrix (creating a large-patch habitat; LPH); or (2) blend of sand and humus-litter mixture (creating a small-patch habitat; SPH). Ten species of bacteria and ten species of fungi, and two bacterial-feeding ( Acrobeloides tricornis , Caenorhabditis elegans ) and two fungal-feeding ( Aphelenchus avenae , Aphelenchoides sp.) nematodes wer…

The fouling community as an indicator of fish farming impact in Mediterranean

2007

Fouling species richness, abundance and composition and biomass were chosen as the descriptors of effect of fish farm organic enrichment. The study was carried out in September 2004 in the Gulf of Castellammare (South Tyrrhenian, Mediterranean). The fouling species were sampled from plastic buoys spaced throughout the study area both up- [UP] and down-stream [DOWN]. The results showed that fouling community responded to the chronic input of allochthonous organic matter experiencing local changes more or less significantly with regard to abundance, species composition and general community diversity. Upper fouling would work as a first filter naturally opposed by environment resistance assim…

Lacustrine, profundal meiobenthic oligochaetes as indicators of trophy and organic loading

1994

Meiobenthic and macrobenthic oligochaetes were collected from two depths in Lake Pajanne and examined together with environmental data in which two environmental gradients can be seen. Numbers of Piguetiella blanci, Aeolosoma quaternarium and Aeolosoma hemprichi were positively correlated with oxygen saturation and negatively correlated with total phosphorus and COD suggesting that these species are indicators of oligotrophic conditions. Numbers of Amphichaeta leydigii, Specaria josinae and Vejdovskyella comata were positively correlated with total phosphorus which implies that these species prefer eutrophic conditions. The last three species and Dero digitata showed positive correlations w…

Biogenic methane in freshwater food webs

2010

SUMMARY 1. It has long been known that substantial amounts of methane are produced in anoxic lake sediments, and the components of the methane cycle in lakes have been well described. At oxic–anoxic interfaces, methane-oxidising bacteria (MOB) convert methane to microbial biomass and can be highly productive. However, only recently has methane been recognised as a potentially important carbon and energy source for lake food webs, and some instances have also been reported of methane contribution to river food webs. Stable isotope analysis (SIA) has provided compelling evidence in this respect and has been supplemented by other lines of evidence. 2. In the benthic food webs of lakes, profund…

Smart Cities Atlas

2014

Nuovi e affascinanti esempi sull’innovazione nelle città che provengono dal mondo reale. Ogni parte del mondo industrializzato ha un caso di smart city da mostrare: città e reti di città saranno il punto di contatto delle più importanti iniziative economiche e finanziarie nel prossimo futuro. Il catalogo ampio di città analizzato da una sintetica rappresentazione delle misure applicate da alcune di esse negli ultimi dieci anni nel mondo. Essere una smart city è una sfida difficile da raggiungere, sia per città progettate ex novo come Masdar o Caofedian sia per quelle che hanno una lunga storia dietro, come le città europee. New and fascinating examples about innovation in cities come from t…

Timor Wschodni - 20 lat nadziei i rozczarowań

2019

Computational Techniques for the Analysis of Small Signals in High-Statistics Neutrino Oscillation Experiments

2020

The current and upcoming generation of Very Large Volume Neutrino Telescopes – collecting unprecedented quantities of neutrino events – can be used to explore subtle effects in oscillation physics, such as (but not restricted to) the neutrino mass ordering. The sensitivity of an experiment to these effects can be estimated from Monte Carlo simulations. With the high number of events that will be collected, there is a trade-off between the computational expense of running such simulations and the inherent statistical uncertainty in the determined values. In such a scenario, it becomes impractical to produce and use adequately-sized sets of simulated events with traditional methods, such as M…

Environmental noise and population dynamics of the ciliated protozoa Tetrahymena thermophila in aquatic microcosms

2003

Population theory predicts that the reddened environmental noise, especially in combination with high population growth rate, reddens population dynamics, increases population variability and strengthens environment–population correlation. We tested these predictions with axenic populations of ciliated protozoa Tetrahymena thermophila. Populations with low and high growth rate were cultured in a stable environment, and in environments with sublethal temperature fluctuations that had blue, white and red spectra (i.e. negatively autocorrelated, uncorrelated, or positively autocorrelated, respectively). Population size and biomass of individuals were determined at 3-h intervals for 18 days. Dy…