Taxonomic studies of the Rotifera (Phylum Aschelminthes) from a Central Amazonian varzea lake, Lago Camaleão (Ilha de Marchantaria, Rio Solimões, Amazonas, Brazil)

148 species of rotifers were identified in 22 plankton samples collected in Lago Camaleão, situated on the Ilha de Marchantaria, in the varzea region of the Solimões-Amazonas River system. During the low water period, February, 1981, 33 species were found. During the high water period, July, 1981, after the development of the aquatic vegetation, 138 species were identified. The decomposition of the inundated terrestrial vegetation favors those rotifer species which live on the surface of putrid mud. All are cosmopolitan species of the genera Lepadella, Mytilina, Platyias, Brachionus and Testudinella. Bdelloidea was represented by several species of the genus Rotaria. Several identification errors of former authors were revised, and in this study the following are proposed: Brachionus urceolaris amazonica n. ssp., Keratella nhamunda nov. nom., Lecane (s. str.) aimazoniana nov. nom., Lecane aspasia amazonica n. ssp. New records for the Amazon region include: Lecane (s. str.) stichaeoides HAUER 1938, Mytilina unguipes (LUCKS 1912), Testudinella greeni KOSTE 1981, and Testudinella patina dendradena (DE BEAUCHAMP 1955). Three new taxa are described: Cephatodelta paggia n. sp., Lecane (Monostyla) marchantaria n. sp., and Lepadella (L.) minoruoides n. sp

The parasitic crustaceans of fishes from the Brazilian Amazon. 12. Ergasilus hydrolycus n.sp. (Copepoda: Poecilostomatoida) from Hydrolycus scomberoides (CUVIER)

The female of Ergasilus hydrolycus n. sp. is described from specimens taken from the gills of an Amazonian fish, Hydrolycus scomberoides (CUVIER). The new species is similar to E. bryconis THATCHER, 1981, and to E. jaraquensis THATCHER & ROBERTSON, 1982, in the form of the body, antennae and legs, and in having a curved pectinate seta on the terminal segment of the first exopod. The new species is distinguished from the other two by having a single seta representing the fifth leg, instead of two, and by having a relatively larger antennal claw. Additionally, the pigmentation of E. hydrolycus n. sp., is limited to a single transverse band at the level of the mouth while in the other two species it is diffuse and distributed throughout the body. Also, the uropod of the new species has two main setae and that of E. bryconis has three. The new species is larger than E. jaraquensis

About the relationship between the zooplankton and fluctuating water levels of Lago Camaleão, a Central Amazonian várzea lake

A two-year study of the composition and abundance of the zooplankton was conducted in an Amazonian vãrzea lake, Lago Camaleão. Rotifers were dominant in terms of both species numbers and density. The extremely low standing-stock observed during the high water period is attributed to prevailing poor oxygen conditions and, during extreme floods, current. The species associations of rotifers also reflect the flooding regime and its consequences

Taxonomic studies of the Rotifera from shallow waters on the Island of Maracá, Roraima, Brazil

Four samples collected in the periodically dry, shallow water ecosystems on the island of Maracá (Roraima, Brazil) were investigated for rotifers. This survey is the first in the area. 159 species were identified and the rotifer community is characteristic of small bodies of water with decomposing vegetation. Most of the rotifer species are cosmopolitan. Dicranophorus sebastus (HARRING & MYERS 1928) and Lecane clara (BRYCE 1892) are new for the Neotropics. Three new species are described: Lepadella christinei, L. tricostata and Testudtnella robertsoni

High field CdS detector for infrared radiation

New and highly sensitive method of detecting infrared irradiation makes possible solid state infrared detector which is more sensitive near room temperature than usual photoconductive low band gap semiconductor devices. Reconfiguration of high field domains in cadmium sulphide crystals provides basis for discovery

Arkansas Cotton Variety Test 2016

The primary goal of the Arkansas Cotton Variety Test is to provide unbiased data regarding the agronomic performance of cotton varieties and advanced breeding lines in the major cotton-growing areas of Arkansas

High field CdS detector for infrared radiation

An infrared radiation detector including a cadmium sulfide platelet having a cathode formed on one of its ends and an anode formed on its other end is presented. The platelet is suitably doped such that stationary high-field domains are formed adjacent the cathode when based in the negative differential conductivity region. A negative potential is applied to the cathode such that a high-field domain is formed adjacent to the cathode. A potential measuring probe is located between the cathode and the anode at the edge of the high-field domain and means are provided for measuring the potential at the probe whereby this measurement is indicative of the infrared radiation striking the platelet

Orbit-resolved photometry and echelle spectroscopy of the cataclysmic variable ST LMi during a 2007 high state

We present high-resolution echelle spectra and contemporaneous photometry of the polar ST LMi during a high state in 2007 March. Emission lines at Hα, He I λ5876, and He I λ7065 show similar line profiles over orbital phase and have narrow and broad components. These profile changes with phase are very similar to those reported in earlier high-state studies of ST LMi. The radial velocity curves from double Gaussian fits to the line profiles are interpreted as two crossing curves, neither of which is coincident with the orbital motion of the secondary star. We attribute one component to infall motions near the white dwarf and the other to a gas streaming along magnetic field lines connecting the two stars

Modification of the simple mass balance equation for calculation of critical loads of acidity.

Over the last few years, the simple mass balance equation for the calculation of critical loads of acidity has been gradually modified as the underlying critical load concepts have developed and as problems with particular forms of the equation have been identified, through application in particular countries. The first major update of the equation took place following a workshop held in Vienna, Austria (Hojesky et al. 1993). The workshop was held to discuss problems which had been identified when the then current form of the equation was applied in countries with high rainfall. The problems had largely arisen because of simplifications and assumptions incorporated into the early formulation of the equation. The equation was reformulated to overcome the problems identified at the workshop. However, further problems were identified when the reformulated equation was applied in the UK in situations with a combination of high rainfall, large marine inputs and widespread occurrence of organic soils. A small workshop was, therefore held in Grange-over-Sands, UK in late 1993 to dicuss the problems and to further re-evaluate the equation. The problems had arisen in the UK because of simplifications and assumptions made in the formulation concerning, in particular, cation leaching and uptake. As a result, a more rigorous treatment of these variables was incorporated into the equation. The reformulation of the equation, as derived at the September 1993 workshop is described below

A multipole array magnetic spring

© 2005 IEEE.This paper presents research on a magnetic spring concept, which has application to the development of a vibration isolation table. Features of the design are scalable, noncontact load bearing and a single degree of instability.Will Robertson, Ben Cazzolato, and Anthony Zande