We used Malaise traps to examine the aerial arthropod community in riparian habitats dominated by native willow, exotic saltcedar, or a mixture of these two tree species in central Arizona, USA. Over the course of three sampling periods per year in 2003 and 2004, native habitats had significantly greater diversity (Shannon–Wiener) and supported different arthropod communities compared to exotic...

The trophic relationships of 13 intertidal fish species collected in northern Chile (20°18’S and 20°54’S) from July 1997 to July 1998, the stomach content analysis of 820 specimens, were investigated. The importance of the prey items was assessed by means of gravimetric and frequency of ocurrence methods, together with the Shannon-Wiener (trophic diversity) and Pianka (trophic overlap) indexes....

Structural studies are, in the social sciences, the indirect outcome of modern developments in mathematics which have given increasing importance to the qualitative point of view in contradistinction to the quantitative point of view of traditional mathematics. It has become possible, therefore, in fields such as mathematical logic, set theory, group theory, and topology, to develop a rigorous ...

The impacts of carbon nanotubes (CNTs) including single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) on soil microbial biomass and microbial community composition (especially on ammonium oxidizing microorganisms) have been evaluated. The first exposure of CNTs lowered the microbial biomass immediately, but the values recovered to the level of the control at the end ...

Arthropods are an important group of macroorganisms that work to maintain ecosystem health. Despite the agricultural benefits of chemical control against arthropod pests, insecticides can cause environmental damage. We examined the effects of one and two applications of the insecticides chlorfenapyr (0.18 liters a.i. ha-1) and methamidophos (0.45 liters a.i. ha-1), both independently and in com...

The effects of dissolved oxygen on simultaneous nitrification and denitrification were evaluated in polyurethane foam contact oxidation reactors in a municipal wastewater treatment process. It was observed that nitrate could be removed at low dissolved oxygen levels, but the removal rate was gradually reduced as the dissolved oxygen concentration increased to a higher level of 6.0 mg/L. Nitroge...

UNLABELLED PREMISE OF THE STUDY Microsatellite markers were developed in the invasive species Bidens alba (Asteraceae) to assess its population structure and to facilitate tracking its expansion in China. • METHODS AND RESULTS Using 454 pyrosequencing, 20 microsatellite primer sets were developed for B. alba. The markers were tested on one population of B. alba (30 individuals) and one pop...

This paper aims at obtaining universal laws and absolute lower bounds of feedback systems using information theory. The feedback system setup is that with causal plants and causal controllers. Three laws (entropy rate never decreases, generalized Bode integral, and absolute lower bound in variance minimization) are obtained, which are in entropy domain, frequency domain, and time domain, respec...

Dioscorea bulbifera L. is widely distributed in pantropical regions along the equator. The taxonomic treatment of this species is ambiguous due to its extreme polymorphic morphological characters. In order to provide tools to facilitate the study of genetic diversity, population structure, patterns of gene flow, and the mating system of this species, and to assess intraspecific variability and ...

In this paper we attempt to give a historical account of the main ideas leading to the development of non-linear filtering and stochastic control as we know it today. The paper contains six sections. In Section 2 we present a development of linear filtering theory, beginning with Wiener-Kolmogoroff filtering and ending with Kalman filtering. The method of development is the innovations method a...