Toxic blue-green algae: The "problem" in perspective

The incidence of blue-green algal blooms and surface scum-formation are certainly not new phenomena. Many British and European authors have been faithfully describing the unmistakable symptoms of blue-green algal scums for over 800 years. There is no disputing that blue-green algal toxins are extremely harmful. Three quite separate categories of compound have been separated: neurotoxins; hepatotoxins and lipopolysaccharides. There is a popular association between blue-green algae and eutrophication. Certainly the main nuisance species - of Microcystis, Anabaena and Aphanizomenon are rare in oligotrophic lakes and reservoirs. Several approaches have been proposed for the control of blue-green algae. Distinction is made between methods for discharging algae already present (eg algicides; straw bales; viruses; parasitic fungi and herbivorous ciliates), and methods for averting an anticipated abundance in the future (phosphorous control, artificial circulation etc).

The influence of blue-green algae on development of the zooplankton. [Translation of: Byull.mosk.Obshch.Ispyt.Prir.(Biol.) 67, 128-131, 1962]

Many have observed the reduction of the quantity of zooplankton in the presence of water blooms. It is known that in seas zooplankton as it were avoids places of accumulation of blue-green algae. By observations on one of the tributaries of the Rybinsk reservoir - the River Shumorovka - the authors tried by simultaneous collections to trace the changes in numbers, not only of zoo- and phytoplankton but also of bacteria. The plankton was collected by quantitative nets with suitable numbers of gauze and bacteria were taken account of by the method of direct calculation on membrane filters. It can be seen that the development of blue-green algae appears as an important factor, determining not only the intensity but also the direction of the process of production of zooplankton.

Discovery of viruses lysing blue-green algae in the Dneprovsk reservoirs. [Translation of: Water blooms (ed. A. V. Topachevskii) pp.171-174. Kiev, Naukova Dumka, 1968]

Viruses, which are characterised by a relative simplicity of chemical composition, are involved with all the groups of the animal and plant world. The discovery of viruses of lower organisms has special interest. Along with the already known viruses lysing bacteria and actinomycetes, viruses have been discovered in recent years which lyse algae. During investigations of water from water-bloom patches and of mud taken from zones of massive accumulation of blue-green algae in the Dneprovsk reservoirs, the authors obtained viruses lysing algae. The revealing of viruses producing lysis of blue-green algae, which one could use in the control of water-blooms, has the greatest interest. With this aim, samples of water were collected from various zones of water-bloom patches in the Kremenchug, Dneprovsk and Kukhov reservoirs. For viruses lysing algae we propose the name 'algophages'. Along with the existence of viruses of algae of the phage type, one cannot deny the possibility of the existence of viruses of another type, multiplying in the cells of algae and causing their virus illnesses.

The possibilities and dangers in using malachite green in pisciculture.[Translation from: Informatsionnyi Byulleten Biologiya Vnutrennikh Vod No.3 17-21, 1969.]

For many years a dye has been used in the practise of pisciculture and pond management, which is known by the name of malachite green, and is used to combat fungus on fish, fish eggs and external animal parasites on fish. The authors describe the problem of the application of malachite green in pisciculture and undertake special, complementary research.

Refractive-index change and sensitivity improvement in holographic recording in LiNbO3:Ce:Cu crystals with green light

Nonvolatile holographic recording is performed with green light in LiNbO3:Ce:Cu crystals. The refractive-index change and the recording sensitivity are times better than those obtained by recording with red light, and higher optical fixing efficiency is obtained. Correspondingly, theoretical investigations are given.

El efecto de la acidificación de los océanos sobre microalgas de la división chlorophyta

Se cultivaron tres cepas de la división Chlorophyta (Nephroselmis pyriformis cepa CGA7, Pyramimonas orientalis cepa CGA13 y Pyramimonas propulsa cepa CGA16) en medios a cuatro pH diferentes (rango desde un control a pH 8.1 a pH7.2). Se midieron las tasas de crecimiento para cada cepa y tratamiento. Las cepas no mostraron una respuesta uniforme a la acidificación del medio, aunque todas mostraron un incremento de sus tasas de crecimiento a pH 7.5. Únicamente N. pyriformis mostró un incremento de sus tasas de crecimiento a pH 7.2. Se concluye que la división Chlorophyta no muestra una respuesta uniforme a la acidificación del medio, pero que las tasas de crecimiento pueden verse incrementadas para las especies testadas en futuros escenarios de acidificación de los océanos.

The impact of Cow Green Reservoir on invertebrate populations in the River Tees

Cow Green is a new reservoir situated in Pennine moorland. It has an area of 312 ha, a capacity of 40 . 9 x 10 SUP-6 m SUP-3 and a maximum depth of 22 . 8 m. The function of the reservoir is to regulate flow in the River Tees to provide industrial Teesside with sufficient water during the dry spells. Invertebrate studies were carried out in the Tees to monitor changes resulting from the construction of the reservoir both in the flooded basin and below the dam. The overall effect of the reservoir on the Tees has been to increase the numbers and biomass of certain taxa, but generally not at the expense of previous fauna. Some of the positive effects, ie. increase in number and biomass, and maintenance of faunal diversity, may in part be attributable to the presence of the rapids and waterfall. Turbulence resulting from this rapid flow over heterogeneous bottom is sufficient to prevent clogging of interstitial spaces by silt and to maintain the variety of ecological niches necessary for a diverse fauna.

Effects of Cow Green Reservoir upon downstream fish populations

Post impoundment observations on the fish populations of the River Tees, downstream from the Cow Green Reservoir were made between 1971 and 1980. Both bullhead (Cottus gobio L.) and brown trout (Salmo trutta L.) population densities increased in the river after impoundment but changes in growth rate were small. Investigations into the stomach contents of the two species reflects the results of other work on increases of benthos in the river. Following regulation there was an increase in the quantity of Ephemerella ignita found in trout stomachs while in the bullhead, regulation caused an increase in the importance of Mollusca and a decrease in importance of Ephemeroptera and Plecoptera.

On concentrated loads and Green's functions in elastostatics

This investigation is concerned with the notion of concentrated loads in classical elastostatics and related issues. Following a limit treatment of problems involving concentrated internal and surface loads, the orders of the ensuing displacements and stress singularities, as well as the stress resultants of the latter, are determined. These conclusions are taken as a basis for an alternative direct formulation of concentrated-load problems, the completeness of which is established through an appropriate uniqueness theorem. In addition, the present work supplies a reciprocal theorem and an integral representation-theorem applicable to singular problems of the type under consideration. Finally, in the course of the analysis presented here, the theory of Green's functions in elastostatics is extended.

Fast Lattice Green's Function Methods for Viscous Incompressible Flows on Unbounded Domains

In this thesis, a collection of novel numerical techniques culminating in a fast, parallel method for the direct numerical simulation of incompressible viscous flows around surfaces immersed in unbounded fluid domains is presented. At the core of all these techniques is the use of the fundamental solutions, or lattice Green’s functions, of discrete operators to solve inhomogeneous elliptic difference equations arising in the discretization of the three-dimensional incompressible Navier-Stokes equations on unbounded regular grids. In addition to automatically enforcing the natural free-space boundary conditions, these new lattice Green’s function techniques facilitate the implementation of robust staggered-Cartesian-grid flow solvers with efficient nodal distributions and fast multipole methods. The provable conservation and stability properties of the appropriately combined discretization and solution techniques ensure robust numerical solutions. Numerical experiments on thin vortex rings, low-aspect-ratio flat plates, and spheres are used verify the accuracy, physical fidelity, and computational efficiency of the present formulations.

Calcite covering of sediment as a possible way of curbing blue-green algae

Natural calcite precipitation in lakes is a well-known control mechanism of eutrophication. In hard-water lakes, calcite deposits on the flat bottoms of shallow lakes and near the shores of deeper lakes resulted from biogenic decalcification during the millenia after the last glacial period. The objective of a new restoration technology is to intensify the natural process of precipitation by utilizing the different qualities of calcareous mud layers. In a pilot experiment in Lake Rudower See, East Germany, phosphorus-poor deeper layers of the sediments were flushed out and spread over the phosphorus-rich uppermost sediments, to promote the co- precipitation of calcite with phosphorus from the water-column.

Numerical and experimental analysis on green laser crystallization of amorphous silicon thin films

The effect of laser fluence on the crystallization of amorphous silicon irradiated by a frequency-doubled Nd:YAG laser is studied both theoretically and experimentally. An effective numerical model is set up to predict the melting threshold and the optimized laser fluence for the crystallization of 200-nm-thick amorphous silicon. The variation of the temperature distribution with time and the melt depth is analyzed. Besides the model, the Raman spectra of thin films treated with different fluences are measured to confirm the phase transition and to determine the optimized fluence. The calculating results accord well with those obtained from the experimental data in this research. (C) 2008 Elsevier Ltd. All rights reserved.

Analysis on fluorescence intensity reverse photonic phenomenon between red and green fluorescence of oxyfluoride nanophase vitroceramics

An interesting fluorescence intensity reverse photonic phenomenon between red and green fluorescence is investigated. The dynamic range. of intensity reverse between red and green fluorescence of Er( 0.5) Yb( 3): FOV oxyfluoride nanophase vitroceramics, when excited by 378.5nm and 522.5nm light respectively, is about 4.32 x 10(2). It is calculated that the phonon- assistant energy transfer rate of the electric multi- dipole interaction of {(4)G(11/2)( Er3+) -> F-4(9/2)( Er3+), F-2(7/2)( Yb3+). F-2(5/2)( Yb3+)} energy transfer of Er( 0.5) Yb( 3): FOV is around 1.380 x 10(8) s(-1), which is much larger than the relative multiphonon nonradiative relaxation rates 3.20 x 10(5) s(-1). That energy transfer rate for general material with same rare earth ion's concentration is about 1.194 x 10(5) s(-1). These are the reason to emerge the unusual intensity reverse phenomenon in Er( 0.5) Yb( 3): FOV. (C) 2007 Optical Society of America.

Cultura de microalgas marinhas Isochrysis galbana , Green (variedade T. Iso) e Tetraselmis suecica (Kilin) Butch

The experimental cultures of the marine microalgae Isochrysis galbana Green (variety T. Iso) and Tetraselmis suecica (Kylin) Butch for feeding mussel larvae are described in detail.

Green and red upconversion luminescence in ytterbium-sensitized erbrium-doped novel lead-free germanium bismuth lanthanum glass

Structural and infrared-to-visible upconversion fluorescence properties in ytterbium-sensitized erbrium-doped novel lead-free germanium bismuth-lanthanum glass have been studied. The structure of lead-free germanium-bismuth-lanthanum glass was investigated by peak-deconvolution of Raman spectrum, and the structural information was obtained from the peak wavenumbers. Intense green and red emissions centered at 525, 546, and 657 nm, corresponding to the transitions 2H(11/2) -> I-4(15/2), S-4(3/2) -> I-4(15/2), and F-4(9/2) -> I-4(15/2), respectively, were observed at room temperature. The quadratic dependence of the 525, 546, and 657 nm emissions on excitation power indicates that a two-photon absorption process occurs under 975 nm excitation. This novel lead-free germanium-bismuth-lanthanum glass with low maximum phonon energy (similar to 751 cm(-1)) can be used as potential host material for upconversion lasers. (c) 2005 Published by Elsevier B.V.