Sample records for chemosterilants
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Chemosterilization: Spermatogenesis, Steroidogenesis ...
African Journals Online (AJOL)
the oxidative stress inducing (i.e., reactive oxygen species generating) ... of fertility is in direct relation to the degree of motility of sperm.[10] ... female. Furthermore, chemical castration had a greater effect on the decrease of aggression than surgical castration.[16]. In 2001, a study was performed to determine the effects.
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A Review of Techniques for Minimizing Beaver and White-Tailed Deer Damage in Southern Hardwoods
Edward P. Hill; Douglas N. Lasher; R. Blake. Roper
1978-01-01
Methods of reducing beaver and deer damage to hardwood forest resources are reviewed. Beaver controls considered were poisons, chemosterilants, predators, and trapping. Population reduction through trapping with 330 conibear traps for two weeks during two successive years effectively eliminates beaver from small watersheds and shows greater promise for control than...
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International Nuclear Information System (INIS)
Ashraf, M.; Keiser, I.; Harris, E.J.
1976-01-01
Male melon flies, Dacus cucurbitae Coquillett, treated with a single dose of the chemosterilant tepa (tris(l-aziridinyl) phosphine oxide), or with gamma irradiation, either single or fractionated doses, did not differ significantly in sexual competitiveness as determined by percentage hatch of eggs. Mating competitiveness of males treated by either method ranged from 53 to 66 percent of that of untreated males. In another study, melon flies (males and females) sterilized with 0.0125 percent tepa, the threshold dose for both sexes, completely suppressed a population when the ratio was 16:16:1:1 (sterile males-sterile females-untreated males-untreated females) as determined by no egg hatch
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Energy Technology Data Exchange (ETDEWEB)
NONE
1968-06-15
Proceedings of a Symposium jointly organized by the IAEA and the Food and Agriculture Organization of the United Nations and held in Vienna, 4-8 December 1967. The meeting was attended by 82 participants from 29 countries and six international organizations. Contents: Isotope applications - ecology (7 papers); Radiation effect studies - non-genetic (8 papers); Isotope applications - physiology and biochemistry (2 papers); Isotope applications - chemosterilants (2 papers); Sterile-male technique (9 papers); Radiation effect studies - genetic (5 papers); Isotope applications - genetic (1 paper). Each paper is in its original language (21 English, 11 French, 1 Russian and 1 Spanish) and is preceded by an abstract in English with a second one in the original language if this is not English. Discussions are in English. (author)
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Laboratory training manual on the use of nuclear techniques in insect research and control. 3. ed.
International Nuclear Information System (INIS)
1992-01-01
Isotopes are commonly used in agricultural research in developed countries, but because of a lack of both training and equipment isotopic techniques are not frequently used in developing countries. This manual has been prepared with the aim of helping entomologists and others responsible for the control of insects in developing countries become familiar with the potential uses of isotopes and radiation in solving some of their research and insect control problems. After chapters dealing with radiation safety, the general properties of radiation and isotopes (especially those used by entomologists), and radiation detection and assay of radioactivity, two further chapters discuss applications to entomological problems and the sterile insect technique. Numerous case studies are described, and the final chapter also includes a description of eight laboratory exercises to investigate the effects of gamma irradiation and chemosterilants on insects. Refs, figs and tabs
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Elimination of super(14)C-bisazir residues in adult sea lamprey (Petromyzon marinus)
Allen, J.L.; Dawson, V.K.
1987-01-01
Bisazir (P.P-bis(1-aziridinyl)-N-methylphosphinothioic amide), a chemosterilant, was administered to sea lampreys (Petromyzon marinus ) by intraperitoneal injection of 100 mg/kg or by immersion for 2 h in a 100- mg/L aqueous solution of the chemical. Whole body analysis of the injected lampreys showed that total residue concentrations decreased to 4.65 in males and 10.07 in females during the first day after injection, and to 1.46 in males and 3.74 in females after 10 days of withdrawal. Lampreys exposed by bath immersion contained residues of about 25 mu g/g of tissue immediately after exposure. The concentration ( mu g/g) decreased to 1.02 in males and 2.11 in females after 1 day of withdrawal and to 0.51 in males and 0.85 in females after 10 days.
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Laboratory training manual on the use of isotopes and radiation in entomology. 2. ed.
International Nuclear Information System (INIS)
1977-01-01
The revised manual, which incorporates changes particularly regarding applied aspects, consists of 7 parts. Part 1 is divided into separate chapters on the properties of radionuclides and radiations; radiation detection and assay of radioactivity; radiation protection; tracer methodology; 15 N determination; and neutron moderation and γ-ray attentuation techniques. Part 2 is concerned with radiobiology. References and a bibliography are supplied with each part. Part 3 contains 17 mental exercises, part 4 laboratory exercises on a GM counter; a scintillation counter; contamination and decontamination; and exercises on basic utilization principles. Part 5 considers radioisotope uptake and excretion paths through the insect organism; principles of internal and external tagging; with emphasis on insect physiology and ecology; various experiments on insects, and insect sterilization using 60 Co and chemosterilants. Eight Appendices and a Glossary of some basic terms and concepts constitute parts 6 and 7, respectively
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International Nuclear Information System (INIS)
Ciereszko, Andrzej; Wolfe, Tobie D.; Dabrowski, Konrad
2005-01-01
In this study we sought to demonstrate that Comet assay can be applied to sea lamprey sperm DNA fragmentation and used to describe the relationship between sperm DNA damage and sperm fertilizing ability. We show that the assay can be used reliably and accurately, and unlike in the case of mammals, there is no need for additional steps related to improvement of efficacy of lysis and DNA decondensation. This agrees with the presence of histone proteins in lamprey sperm. An increase in DNA fragmentation was noted during short-term storage of milt on ice (0-4 days). We demonstrated genotoxic effects of UV radiation and oxidative stress (exposure to hydrogen peroxide) and found that oxidative damage to sperm DNA was likely repaired after fertilization in the embryo. Repairing capacity of the oocyte toward sperm DNA lesions caused by UV was restricted. Toxic effect of p,p-bis-(1-aziridinyl)-N-methylphosphinothioic acid (p,p-bis(1-aziridinyl)-N-methylphosphinothioic amide), a sea lamprey chemosterilant, could not be linked to DNA fragmentation in the in vitro tests. Its genotoxicity in vivo may possibly be associated with other mechanisms of DNA degradation (oxidation or DNA-protein and DNA-DNA cross-linking). In conclusion, this study demonstrates that Comet assay can be successfully applied to monitor effects of environmental disturbances and imposed injuries in sea lamprey spermatozoa and possibly other species of ancient fish with acrosomal sperm
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Energy Technology Data Exchange (ETDEWEB)
Ciereszko, Andrzej [School of Natural Resources, Ohio State University, 210 Kottman Hall, 2021 Coffey Rd., Columbus, OH 434210 (United States); Semen Biology Group, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, 10-747 Olsztyn (Poland); Wolfe, Tobie D. [School of Natural Resources, Ohio State University, 210 Kottman Hall, 2021 Coffey Rd., Columbus, OH 434210 (United States); Dabrowski, Konrad [School of Natural Resources, Ohio State University, 210 Kottman Hall, 2021 Coffey Rd., Columbus, OH 434210 (United States)]. E-mail: dabrowski.1@osu.edu
2005-06-15
In this study we sought to demonstrate that Comet assay can be applied to sea lamprey sperm DNA fragmentation and used to describe the relationship between sperm DNA damage and sperm fertilizing ability. We show that the assay can be used reliably and accurately, and unlike in the case of mammals, there is no need for additional steps related to improvement of efficacy of lysis and DNA decondensation. This agrees with the presence of histone proteins in lamprey sperm. An increase in DNA fragmentation was noted during short-term storage of milt on ice (0-4 days). We demonstrated genotoxic effects of UV radiation and oxidative stress (exposure to hydrogen peroxide) and found that oxidative damage to sperm DNA was likely repaired after fertilization in the embryo. Repairing capacity of the oocyte toward sperm DNA lesions caused by UV was restricted. Toxic effect of p,p-bis-(1-aziridinyl)-N-methylphosphinothioic acid (p,p-bis(1-aziridinyl)-N-methylphosphinothioic amide), a sea lamprey chemosterilant, could not be linked to DNA fragmentation in the in vitro tests. Its genotoxicity in vivo may possibly be associated with other mechanisms of DNA degradation (oxidation or DNA-protein and DNA-DNA cross-linking). In conclusion, this study demonstrates that Comet assay can be successfully applied to monitor effects of environmental disturbances and imposed injuries in sea lamprey spermatozoa and possibly other species of ancient fish with acrosomal sperm.
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A critical review of so-called cold sterilization in the field of foods
International Nuclear Information System (INIS)
Jordy, A.
1985-01-01
The contamination of raw materials with microorganisms is a potential hazard to human health, especially if these materials are kept for a certain time under conditions that enhance microbial multiplication. Since the goods in question are by no means cheap bulk materials, but are highly ranked substances, the method of germ reduction by heat treatment is not suitable, and various so-called cold sterilizations have to be used (chemical, irradiation). The article examines the value of these, and in particular how they are assessed. Until the sixties, it was mainly the microbicidal effect of these treatments that was judged; today, the emphasis is on the assessment of the secondary reactions of the agents with the treated commodity and in particular their residual toxicity. In the case of chemical treatments, toxicity is determined directly by application of overdoses. It should be stressed that this is not comparable with the indirect assessment of the toxicity of gamma irradiation, by feeding irradiated goods. Of the available chemosterilants, formaldehyde has great disadvantages in spite of its high volatility, because of its high protein factor and its delayed vaporization from surfaces, due to polymerization. Propylene oxide is less active, requiring higher concentrations, which in turn results in increased residues. Therefore, the agent of choice is still ethylene oxide, since it diffuses quickly and is highly reactive; selection of genetically resistant microorganisms is therefore not possible, as opposed to the case of gamma radiation
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Cavalieri, John
2017-06-01
Chemical sterilisation can be used as an alternative to surgical castration in some circumstances. This review focuses on responses to treatment with zinc- or CaCl 2 -based chemosterilants, factors that have affected treatments and their potential use to sterilise female cattle. Successful treatment with a low incidence of adverse side effects in male animals has occurred with the use of zinc gluconate (ZG), neutralised in arginine and a 20% solution of CaCl 2 in ethanol. Injection technique plays an important role in success. Less satisfactory results appear to occur following use in animals with relatively larger testes. In animals with relatively small testes adjustment of the dose according to testicular size appears to optimise results. The techniques appear to be most suited to population control strategies in companion animals where low cost treatment of animals in environments where surgical facilities and specialised aftercare are lacking. The need for careful administration and likely slower speed of administration compared to surgical castration are likely to hamper application within the cattle industries. Recently transvaginal, intraovarian administration of CaCl 2 in ethanol has been shown to cause complete ovarian atrophy without apparent pain in some heifers, although variable responses were found. Chemical sterilisation can play a role in the sterilisation of animals but careful attention to dose, volume, chemical composition, administration technique are needed to avoid adverse side effects and variability in responses associated with some treatments. Application in female animals requires further study but CaCl 2 in ethanol can potentially cause complete ovarian atrophy when administered to heifers. Copyright © 2017 Elsevier B.V. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Curtis, C F [London School of Hygiene and Tropical Medicine (UK); Langley, P A [Bristol Univ. (UK)
1982-01-01
The first laboratory and field experiments on genetic control were with tsetse flies, and they made use of the sterility in crosses and hybrids between closely related species of the Glossina morsitans complex. Backcrosses indicate that there are two separate sterility mechanisms involved: (a) genetic incompatibility between a mother and the products of alien genes in the embryo or larva in the uterus; (b) inability of hybrid males to inseminate due to incompatibility of their X-chromosomes with an alien Y or autosomes. The two largest sterile male release programmes have been in Tanzania and Upper Volta, and have used irradiation at the pupal or adult stage, respectively, for the production of sterility. Male tsetse are remarkably resistant to radiosterilization and, with the doses required to induce dominant lethals in more than 95% of sperms, premature senescence and lethargic behaviour of the males tends to result. With G. morsitans irradiated at the puparial stage these effects can be alleviated by the use of a nitrogen atmosphere during irradiation. If the puparia are then transferred to air at 11/sup 0/C for transport to the release site, immediate emergence occurs on re-warming after arrival. This advantageous procedure was used for the releases in Tanzania. In addition to dominant lethals, irradiation also produces chromosome translocations which cause inherited partial sterility. A homozygous translocation line was selected but this example did not have sufficient fitness to be used in a mass rearing programme. Chemosterilants can be applied by pupal dipping, adult contact with deposits or in aerosols. Studies are now in progress on their use in association with odour-baited traps or pheromone-baited decoys as a means of sterilizing the wild population and thus avoiding the costly and difficult process of mass rearing tsetse.
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The sterile-male-release technique in Great Lakes sea lamprey management
Twohey, Michael B.; Heinrich, John W.; Seelye, James G.; Fredricks, Kim T.; Bergstedt, Roger A.; Kaye, Cheryl A.; Scholefield, Ron J.; McDonald, Rodney B.; Christie, Gavin C.
2003-01-01
The implementation of a sterile-male-release technique from 1991 through 1999 and evaluation of its effectiveness in the Great Lakes sea lamprey (Petromyzon marinus) management program is reviewed. Male sea lampreys were injected with the chemosterilant bisazir (P,P-bis(1-aziridinyl)-N-methylphosphinothioic amide) using a robotic device. Quality assurance testing indicated the device delivered a consistent and effective dose of bisazir. Viability of embryos in an untreated control group was 64% compared to 1% in a treatment group. A task force developed nine hypotheses to guide implementation and evaluation of the technique. An annual average of 26,000 male sea lampreys was harvested from as many as 17 Great Lakes tributaries for use in the technique. An annual average of 16,100 sterilized males was released into 33 tributaries of Lake Superior to achieve a theoretical 59% reduction in larval production during 1991 to 1996. The average number of sterile males released in the St. Marys River increased from 4,000 during 1991 to 1996 to 20,100 during 1997 to 1999. The theoretical reduc-stertion in reproduction when combined with trapping was 57% during 1991 to 1996 and 86% during 1997 to 1999. Evaluation studies demonstrated that sterilized males were competitive and reduced production of larvae in streams. Field studies and simulation models suggest reductions in reproduction will result in fewer recruits, but there is risk of periodic high recruitment events independent of sterile-male release. Strategies to reduce reproduction will be most reliable when low densities of reproducing females are achieved. Expansion of the technique is limited by access to additional males for sterilization. Sterile-male release and other alternative controls are important in delivering integrated pest management and in reducing reliance on pesticides.
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International Nuclear Information System (INIS)
Oloo, F.P.; Langley, P.A.; Luyimbazi, F.; Ogwal, L.M.
2000-01-01
The years of 1970s to 1990s saw the development of bait technology for the control of tsetse flies from their infancy to their optimum levels. The technology relies on attracting the flies to trapping and killing devices, relying on olfactory and visual cues to artificial and natural objects which the flies probably perceive as their hosts. Despite the present level of improvement, the catching or trapping efficiency is low, averaging 20-35%, and some tsetse species hardly respond to these techniques. This makes sustaining control programmes to a level where economic development can proceed effectively elusive, leading to the re-invasion and collapse of many tsetse control projects. Efforts are therefore being made to incorporate different killing methods into the trapping systems. Lethal insect techniques (LIT) with pathogens, insect growth regulators and other chemosterilants are incorporated into bait technology to amplify their effectiveness as the flies can transfer them to other members of the species which cannot get access to the attractive devices. They are compatible with the sterile insect technique. Prospects for autosterilisation of the tsetse flies have been reviewed by Langley and Coates (1982) who also assessed the incorporation of sex pheromones and bisazir in the field. Encouraging field results were obtained with Pyroprxyfen (Sumitomo Chemical Co.) which is a juvenile hormone mimic that allows the larvae of G. morsitans morsitans to be produced normally but on pupation, further development was arrested after twenty days of the thirty day intrapupal period, 'effectively' making the females sterile (Hargrove and Langley 1990). However, when triflumuron is applied at doses of 0.5 micrograms per tsetse fly the following reproductive cycle was arrested with no recovery over four reproductive cycles (forty five days). Birth products of the sterilised flies ranged from abortion of eggs to fully grown larvae which formed non-viable puparia. The aim of
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The sterile insect technique: Cost-effective control of the Mediterranean fruit fly
International Nuclear Information System (INIS)
Gomez Riera, Pablo
2001-01-01
occur and must be dealt with in Florida and California, Mexico and Chile. Fruit flies, like any other pest, have been attacked with biocides at the farm level. Citrus is an instructive example. Citrus flowers and fruits twice a year, and various species and varieties provide year-round harvests. Biocides are typically applied to citrus every 10-15 days. Even so, the effectiveness is usually only 70-80%, due to uncontrolled neighboring farms, untreated hosts, problems with the spraying equipment, dose miscalculations, etc. Aerial applications of bait sprays to wider areas are more expensive, require a regional plan, and can represent a major impact to the environment. All means of application can leave pesticide residues in the fruit. Trade in fresh fruits and vegetables is being liberalized on a world-wide basis as part of globalization. At the same time, local consumption of fresh products is increasing in the search for a healthier life. Pesticides are increasingly less acceptable in both the export trade and local markets. Newly adopted food safety and phytosanitary standards require the establishment of either low prevalence or entirely fruit fly-free areas. Environmental considerations reinforce the already favorable cost-benefit picture for the Sterile Insect Technique (SIT) as an alternative to controls that use chemicals alone. The SIT has been in use since the 1950s. The aim of the technique is to disrupt the life cycle of the fly, mating the wild population with sterile flies reared at a 'fly factory'. Sterilization is accomplished by exposing insects to a specific dose of gamma radiation emitted by radioisotopes (cobalt-60 or cesium-137). Irradiation is a central and indispensable part of the total SIT process: every insect among millions produced each week must to be sterilized. No other method is available to achieve sterilization; chemosterilants, linear accelerators and the like have proven less cost-effective
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The sterile insect technique: Cost-effective control of the Mediterranean fruit fly
Energy Technology Data Exchange (ETDEWEB)
Gomez Riera, Pablo [INTA La Consulta, Mendoza (Argentina)
2001-07-01
occur and must be dealt with in Florida and California, Mexico and Chile. Fruit flies, like any other pest, have been attacked with biocides at the farm level. Citrus is an instructive example. Citrus flowers and fruits twice a year, and various species and varieties provide year-round harvests. Biocides are typically applied to citrus every 10-15 days. Even so, the effectiveness is usually only 70-80%, due to uncontrolled neighboring farms, untreated hosts, problems with the spraying equipment, dose miscalculations, etc. Aerial applications of bait sprays to wider areas are more expensive, require a regional plan, and can represent a major impact to the environment. All means of application can leave pesticide residues in the fruit. Trade in fresh fruits and vegetables is being liberalized on a world-wide basis as part of globalization. At the same time, local consumption of fresh products is increasing in the search for a healthier life. Pesticides are increasingly less acceptable in both the export trade and local markets. Newly adopted food safety and phytosanitary standards require the establishment of either low prevalence or entirely fruit fly-free areas. Environmental considerations reinforce the already favorable cost-benefit picture for the Sterile Insect Technique (SIT) as an alternative to controls that use chemicals alone. The SIT has been in use since the 1950s. The aim of the technique is to disrupt the life cycle of the fly, mating the wild population with sterile flies reared at a 'fly factory'. Sterilization is accomplished by exposing insects to a specific dose of gamma radiation emitted by radioisotopes (cobalt-60 or cesium-137). Irradiation is a central and indispensable part of the total SIT process: every insect among millions produced each week must to be sterilized. No other method is available to achieve sterilization; chemosterilants, linear accelerators and the like have proven less cost-effective.