First transgenic trait for control of plant bugs and thrips in cotton     

Waseem Akbar  Anilkumar Gowda  Jeffrey E Ahrens  Jason W Stelzer  Robert S Brown  Scott L Bollman  John T Greenplate  Jeffrey Gore  Angus L Catchot  Gus Lorenz  Scott D Stewart  David L Kerns  Jeremy K Greene  Michael D Toews  David A Herbert  Dominic D Reisig  Gregory A Sword  Peter C Ellsworth  Larry D Godfrey  Thomas L Clark 《Pest management science》2019,75(3):867-877

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Mechanisms responsible for high levels of permethrin resistance in the house fly     

Jeffrey G. Scott  George P. Georghiou 《Pest management science》1986,17(3):195-206

The mechanisms responsible for > 6000-fold permethrin resistance in a pyrethroid-selected strain of house fly, Learn-PyR, were investigated. Through electrophysiological, in vitro metabolism, in vivo penetration and synergism studies it was demonstrated that the resistance mechanisms consisted of enhanced metabolic detoxification via the mixed-function oxidase (MFO) system, target-site insensitivity and decreased cuticular penetration. The major resistance mechanism was the MFO-mediated detoxification. The elevated MFO activity was correlated with higher levels of cytochrome P-450, cytochrome b₅ and NADPH-cytochrome c reductase activity. The kinetics of the latter showed similar K_m but greater V_max values in the Learn-PyR than in the susceptible strain, suggesting that the elevated activity was due to an altered amount, but not an altered form, of the enzyme. The Learn-PyR strain showed widely varying levels of resistance to the pyrethroids tested. Comparison of the pyrethroid structures with the resistance ratios revealed that resistance was highest in the presence of an unsubstituted phenoxybenzyl alcohol moiety. Substitution or certain modifications of the alcohol moiety reduced the level of resistance. Structure of the acid moiety or the presence or absence of an a-CN group did not affect the resistance level. These results are discussed with reference to the resistance mechanisms present.  相似文献   

Activity of two novel insecticides against permethrin-resistant Pseudoplusia includens     

James D. Thomas  Jeffrey S. Mink  David J. Boethel  Alan T. Wier  B. Roger Leonard 《Pest management science》1994,40(3):239-243

Two experimental insecticides, AC 303,630 and MK 244, were tested against a laboratory colony and three field strains of Pseudoplusia includens (Walker). Topical application bioassays indicated that permethrin resistance in the field strains ranged from 3.9 to 489.0-fold. In leaf dip bioassays, LC₅₀ and LC₉₀ values for AC 303,630 ranged from 6.7 to 15.1 mg litre ?1 and 8.7 to 28.2 mg litre ?1, respectively, for third-instar larvae. The Louisiana 1991 field strain was significantly more susceptible to AC 303,630 than the laboratory and other field strains. The LC₅₀ (but not LC₉₀) for the Louisiana 1992 field strain was significantly higher than that of the laboratory strain. However, there was no difference in toxicity of AC 303,630 between the field strain with the highest level of permethrin resistance and the laboratory strain. LC₅₀ and LC₉₀ values for MK 244 in leaf dip bioassays ranged from 0.014 to 0.023 mg litre ?1 and 0.079 to 0.174 mg litre ?1, respectively. There were no significant differences in LC 50 or LC 90 among any of the strains for MK 244. Field trials in soybean were also conducted in 1991 and 1992 in an area of Louisiana where permethrin efficacy against P. includens has declined. In both years, AC 303,630 at 0.11–0.22 kg ha ?1, and MK 244 at 0.0042–0.0084 kg ha ?1, provided significantly better control than permethrin at 0.11 kg ha ?1, and control equal to the recommended standard, thiodicarb. These studies indicate no cross-resistance exists between the experimental insecticides and permethrin.  相似文献   

Carbon monoxide toxicity: a case series     

Allyson C. Berent  DVM    Jeffrey Todd  DVM    Jennifer Sergeeff  DVM  DACVIM    Lisa L. Powell  DVM  DACVECC 《Journal of Veterinary Emergency and Critical Care》2005,15(2):128-135

Objective: To describe diagnostics, therapy, and sequelae of acute carbon monoxide (CO) toxicity because of a motor vehicle generator in 4 dogs and 2 cats. Series summary: Four dogs and 2 cats presented for recumbency, disorientation, dyspnea, and stiffness after an estimated 6–8 hour exposure to exhaust from a generator. Diagnostics included a serum carboxyhemoglobin levels evaluation, arterial blood gas analysis, pulse oximetry readings, and blood pressure measurements. Initial therapy included oxygen (O₂) administration, intravenous bronchodilators, fluids, and a hemoglobin‐based O₂ carrying (HBOC) molecule. Following administration of the HBOC, 4 of the 6 animals showed dramatic clinical improvement. Two weeks after hospital discharge, the owner reported potential hearing deficits in all animals. Brain auditory evoked response (BAER) tests were conducted in all surviving animals and some degree of hearing impairment was documented in all cases, with complete clinical resolution noted 6 weeks later. Unique information provided: This report describes the therapeutic use of an HBOC in acute isolated CO toxicity (i.e. without the complications of smoke inhalation). In addition, delayed nervous system dysfunction was documented in all surviving animals.  相似文献   

Monitoring insecticide resistance in house flies (Diptera: Muscidae) from New York dairies     

Phillip E Kaufman  Jeffrey G Scott  Donald A Rutz 《Pest management science》2001,57(6):514-521

House flies were collected from dairies across New York state and the levels of resistance to seven insecticides were measured using standard laboratory assays with three to five diagnostic concentrations. The highest levels of resistance were found for tetrachlorvinphos, permethrin and cyfluthrin. Although levels of resistance to methomyl were somewhat lower, they were among the highest ever reported for field‐collected house flies. Resistance to pyrethrins was limited primarily to the lowest diagnostic concentration. House flies were susceptible to fipronil at all dairies, suggesting that this material would be highly effective for fly control. The levels of resistance were similar at all the dairies, irrespective of their insecticide use, suggesting substantial movement of flies between facilities. Relative to resistance levels found at New York dairies in 1987, resistance levels had increased for permethrin, were unchanged for tetrachlorvinphos and had decreased for dimethoate. To identify a single diagnostic concentration that could be used in the laboratory assays to assess accurately resistance levels in future studies, we carried out a ‘simulated’ field bioassay using formulated materials. A diagnostic concentration for each insecticide is proposed on the basis of a comparison of our bioassays. © 2001 Society of Chemical Industry  相似文献   

NOCTURNAL ACTIVITY OF BIRDS ON SHRIMP MARICULTURE PONDS     

Jeffrey L. Beynon  David L. Hutchins  Anthony J. Rubino  Addison L. Lawrence  Brian R. Chapman 《Journal of the World Aquaculture Society》1981,12(2):63-70

Birds can reduce production of shrimp in mariculture grow-out ponds through predation and competition for feed. This study involved weekly nocturnal enumeration of bird populations and observation of nocturnal avian habits on a series of 0.1 ha experimental ponds at the Texas A&M University Shrimp Mariculture Facility at Corpus Christi, Texas. Observations were conducted hourly from sunset to sunrise during October through December 1980. The rate of predation was evaluated every three hours by comparing the number of feeding attempts to the number of successful prey captures over a known time period. Gulls (Family Laridae) acted primarily as competitors for feed. Active feeding by gulls was restricted to daylight hours, consequently feed loss decreased when the feed was distributed at or after dusk. Major preadatory birds included herons and egrets (F. Ardeidae), migratory ducks (F. Anatidae), and, to a lesser extent, grebes (F. Podicipedidae) and shorebirds (Order Charadriiformes). Bird predation decreased pond production by 75% in some ponds.  相似文献   

Math and science education. Congress lets states share the wealth     

Mervis J 《Science (New York, N.Y.)》2003,299(5614):1825

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Detection, quantification, and pharmacokinetics of furosemide and its effects on urinary specific gravity following IV administration to horses     

Dirikolu L  Lehner AF  Hughes C  Karpiesiuk W  Camargo FC  Harkins JD  Woods WE  Bosken JM  Boyles J  Troppmann A  Fisher M  Tobin T 《Veterinary therapeutics : research in applied veterinary medicine》2003,4(4):350-363

Furosemide is a potent loop diuretic used for the prevention of exercise-induced pulmonary hemorrhage in horses. This drug may interfere with the detection of other substances by reducing urinary concentrations, so its use is strictly regulated. The regulation of furosemide in many racing jurisdictions is based on paired limits of urinary SG (<1.010) and serum furosemide concentrations (>100 ng/ml). To validate this regulatory mechanism, a liquid chromatography/mass spectrometry/mass spectrometry method employing a solid-phase extraction procedure and furosemide-d5 as an internal standard was developed. The method was used to determine the pharmacokinetic parameters of furosemide in equine serum samples and its effects on urinary SG after IV administration (250 mg) to 10 horses. Pharmacokinetic analysis showed that serum concentrations of furosemide were well described by a two-compartmental open model. Based on results in this study, it is very unlikely for horses to have serum furosemide concentrations greater than 100 ng/ml or urine SG less than 1.010 at 4 hours after administration (250 mg IV). However, it should be remembered that urine SG is a highly variable measurement in horses, and even without furosemide administration, some horses might naturally have urine SG values less than 1.010.  相似文献   

Effect of furosemide on urine specific gravity and osmolality in thoroughbred racehorses     

Bosken JM  Tobin T  Mundy GD  Fisher M  Gantz MG  Banks RO 《Veterinary therapeutics : research in applied veterinary medicine》2003,4(3):292-298

Postrace urine samples from thoroughbred horses were examined to compare osmolality and specific gravity between horses treated with furosemide and those not treated. Samples were assigned to groups in relation to reported medication (furosemide) status, race finish position, and distance of race. Urine osmolality was significantly (P <.05) lower in samples from horses treated with furosemide when compared with untreated horses. Specific gravity determinations are less precise at measuring urine osmolality at lower levels (1.01 g/ml or less). The measurement of osmolality is a superior method for determining the urine solute concentration and facilitating the regulation of furosemide.  相似文献   

A review of porcine tonsils in immunity and disease     

Horter DC  Yoon KJ  Zimmerman JJ 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2003,4(2):143-155

The porcine tonsils are a group of lymphoepithelial tissues located at the common openings of the gastrointestinal and respiratory tracts. The tonsils participate in a variety of functions involving innate, cellular and humoral immunity at the local and systemic levels. Among these immunological functions is the continuous surveillance for the presence of foreign antigens at the openings of the gastrointestinal and respiratory tracts. Within the pig, the movement of lymphocytes, cytokines and chemotactic molecules from the tonsils to other lymphoid organs confers immunity to other portals of pathogen entry and facilitates an efficient and rapid systemic immune response. In spite of the immunological nature of the tonsils, some microorganisms have acquired adaptations that allow them to circumvent the tonsillar immune defenses and utilize the tonsils as a site of entry, replication and colonization. Several bacterial and viral pathogens persist asymptomatically within the tonsils, making identification of asymptomatic carrier animals difficult in disease control and/or pathogen elimination. This paper reviews the current information on the anatomy, immunology and pathobiology of porcine tonsils and discusses the tonsils as a site of pathogen entry, replication and colonization using Salmonella spp., classical swine fever virus and porcine reproductive and respiratory syndrome virus as examples.  相似文献