Control of macrophytes by grass carp (ctenopharyngodon idella) in a Waikato drain, New Zealand

Hornwort (Ceratophyllum demersum L.) and other aquatic macrophytes have historically been mechanically removed from the Rangiriri drain and Churchill East drain to maintain drain efficiency. As an alternative control method for the high plant biomass that accumulates at the end of summer, the effect of stocking diploid grass carp (Ctenopharyngodon idella L.) on the aquatic vegetation was evaluated in these Waikato drainage systems. At the start of the trial, both drains had a low diversity of aquatic macrophytes, and of the nine species (including the emergents), seven were exotic. Two months after grass carp were released to Churchill East drain (the treated drain) the four submerged and floating macrophyte species became scarce in the main drain. Over the same period, these species increased in biomass in Rangiriri drain (the untreated drain), where hornwort became dense and surface-reaching and remained so for the duration of the trial. However, grass carp did not control submerged vegetation in smaller side drains or the shallow, upper parts of the main drain, or the marginal sprawling species and emergent species. The cost of leasing the grass carp was similar to the cost of clearing the drains mechanically, but grass carp provided continuous weed control. However, subsequent to this trial, 62 dead grass carp were found in Churchill East drain in February 2001, and weed cover subsequently increased. This illustrates that grass carp management in New Zealand agricultural drains can be problematic due to periodic fish kills

Coherent state triplets and their inner products

It is shown that if H is a Hilbert space for a representation of a group G, then there are triplets of spaces F_H, H, F^H, in which F^H is a space of coherent state or vector coherent state wave functions and F_H is its dual relative to a conveniently defined measure. It is shown also that there is a sequence of maps F_H -> H -> F^H which facilitates the construction of the corresponding inner products. After completion if necessary, the F_H, H, and F^H, become isomorphic Hilbert spaces. It is shown that the inner product for H is often easier to evaluate in F_H than F^H. Thus, we obtain integral expressions for the inner products of coherent state and vector coherent state representations. These expressions are equivalent to the algebraic expressions of K-matrix theory, but they are frequently more efficient to apply. The construction is illustrated by many examples.Comment: 33 pages, RevTex (Latex2.09) This paper is withdrawn because it contained errors that are being correcte

USSR Space Life Sciences Digest, issue 6

This is the sixth issue of NASA's USSR Space Life Sciences Digest. It contains abstracts of 54 papers recently published in Russian language periodicals and bound collections and of 10 new Soviet monographs. Selected abstracts are illustrated with figures and tables from the original. Additional features include a table of Soviet EVAs and information about English translations of Soviet materials available to readers. The topics covered in this issue have been identified as relevant to 26 areas of aerospace medicine and space biology. These areas are adaptation, biospherics, body fluids, botany, cardiovascular and respiratory systems, developmental biology, endocrinology, enzymology, exobiology, genetics, habitability and environment effects, health and medical treatment, hematology, human performance, immunology, life support systems, mathematical modeling, metabolism., microbiology, morphology and cytology, musculoskeletal system, neurophysiology, nutrition, perception, personnel selection, psychology, radiobiology, reproductive biology, and space medicine

More Hidden Opposites

In the February 1973 issue of Word Ways, Mary Youngquist challenged readers to find opposites (such as GIVE-TAKE) from transposed clues (such as KITE-GAVE). I found it easier to work on her list in reverse -- that is, think of a pair of opposites and then check to see if the transposed letters were present. In this quest, I inevitably came across a number of opposites that she did not use. Here is a fresh batch of fifty scrambled opposites for readers to try and solve. If you give up, the answers can be found in Answers and Solutions at the end of this issue

Watching and Weaving Woven Words

I have what some might call a despicable habit of seeing words within words, like spotting the COP in SCOPE or detecting the ART in GARRETS, but the habit is recreational. Noting in the latter that the inner word was spelled with the letters in the even-numbered positions while the odd letters GRES did not form a common word, I began looking for woven words for which both the even and the odd groups were interwoven words

Erosion/corrosion of turbine airfoil materials in the high-velocity effluent of a pressurized fluidized coal combustor

Four candidate turbine airfoil superalloys were exposed to the effluent of a pressurized fluidized bed with a solids loading of 2 to 4 g/scm for up to 100 hours at two gas velocities, 150 and 270 m/sec, and two temperatures, 730 deg and 795 C. Under these conditions, both erosion and corrosion occurred. The damaged specimens were examined by cross-section measurements, scanning electron and light microscopy, and X-ray analysis to evaluate the effects of temperature, velocity, particle loading, and alloy material. Results indicate that for a given solids loading the extent of erosion is primarily dependent on gas velocity. Corrosion occurred only at the higher temperature. There was little difference in the erosion/corrosion damage to the four alloys tested under these severe conditions

The Words of Songs Without Words

Fortunately for me, with a great love for good music and no talent, my late wife was a concert cellist. Her musical education had included fifteen years of private study in this country and a formal course at the Conservatoire Royal de Musique de Bruxelles, from which she was a prize graduate in 1914. Ignorant and curious, I asked her the reason for foreign study -- what could she learn in Belgium that wasn\u27t taught in the United States? She listed a number of topics in reply, with emphasis on counterpoint, ensemble and solfege

Another Interlaced Charade

I am often intrigued by words within words. Recently, I came across one of 15 letters which can be divided into 5 very common shorter words as indicated: xxxxxx-xx-x-xxx-xxx. Delving deeper, I found it held many more such words -- some forwards nad some backwards. This suggested dissecting it into all of its many parts, hinting at their identifications, and offering it as a bit of recreation for readers to synthesize the parts back to the whole. For that purpose, the 15 letters are numbered in order