976 resultados para Moore, Marcel


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Headspace analysis and solvent extraction of the pollenbearing flower spike of Spathiphyllum cannaefolium have been conducted by GC-MS, to determine the basis of the flower spike’s attractancy to certain fruit-fly species. The major components were benzyl acetate, methyleugenol, methylchavicol, p-methoxybenzyl acetate and fatty acids. Benzyl acetate is known to be attractive to D. cueurbitae, D. dorsalis and C. capitata (representing the three different ‘male-lure categories’) and methyleugenol (one of these male-lures) attracts D. cacuminatus, D. dorsalis and D. occipitalis. Thus the odoriferous flowerspike exhibits wide ranging attractancy and hence Spathiphyllum cannaefolium may have some application as a fruit-fly control measure for small orchards where ‘methyleugenol-attracted’ species (e.g. D. cacuminatus, D. dorsalis, D. occipitalis) are the dominant pests.

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Ultrastructural and electrophysiological investigations carried out on larval rasters of Rhopaea magnicomis Blackburn, Lepidiota frerzclzi Black, and Antitr-ogus consanguineus Blackburn revealed that the raster is a complex of mechanoreceptive setae. Chemical and morphological investigations provide no evidence that the raster is a site for chemical emissions; however, species differences in hydrocarbon profiles were found among larval cuticle samples. Ultrastructure of the setae (pali) show that each seta is innervated by a single dendrite which ends in a tubular body at the base of the seta. The connection with the seta is on the proximal side, which corresponds to the production of a phasic-tonic electrophysiological signal on downward deflection. The dendrite is surrounded by a granular, electron-dense sheath which has inwardly directed arms distally and outwardly directed arms proximally. Two sheath cells are present, 1 forming a large receptor lymph cavity which is lamellate and lined with electron-dense material.

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Traps baited with synthetic aggregation pheromone and fermenting bread dough were used to monitor seasonal incidence and abundance of the ripening fruit pests, Carpophilus hemipterus (L.), C. mutilatus Erichson and C. davidsoni Dobson in stone fruit orchards in the Leeton district of southern New South Wales during five seasons (1991-96). Adult beetles were trapped from September-May, but abundance varied considerably between years with the amount of rainfall in December-January having a major influence on population size and damage potential during the canning peach harvest (late February-March). Below average rainfall in December-January was associated with mean trap catches of < 10 beetles/trap/week in low dose pheromone traps during the harvest period in 1991/92 and 1993/94 and no reported damage to ripening fruit. Rainfall in December-January 1992/93 was more than double the average and mean trap catches ranged from 8-27 beetles/week during the harvest period with substantial damage to the peach crop. December-January rainfall was also above average in 1994/95 and 1995/96 and means of 50-300 beetles/trap/week were recorded in high dose pheromone traps during harvest periods. Carpophilus spp. caused economic damage to peach crops in both seasons. These data indicate that it may be possible to predict the likelihood of Carpophilus beetle damage to ripening stone fruit in inland areas of southern Australia, by routine pheromone-based monitoring of beetle populations and summer temperatures and rainfall.

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A survey for various mycotoxins was carried out on samples of all wheat delivered to nine storage and marketing depots in south-eastern Queensland, selected as most likely to receive mycotoxin-contaminated grain. All wheat was surveyed during 1983, when the degree of weather damage was high. Samples of the poorest grade of wheat from these depots were also surveyed in 1984 and 1985. The surveys included all regions where head scab of wheat caused by Fusariurn graminearurn Schwabe Group 2 had been reported to occur at significant levels. 4-Deoxynivalenol was detected in nearly all pooled samples representing bulk wheat at concentrations ranging from traces of <0.01 up to 1.7 mg kg-1. The highest concentration of zearlenone detected in a pooled wheat sample was 0.04 mg kg-1. In a few samples representing individual wheat deliveries and with up to 2.8% by weight of pink grains, 4-deoxynivalenol concentrations ranged up to 11.7 mg kg-' and zearalenone up to 0.43 mg kg-l. Aflatoxins B,, B2, G1 and G2 were detected in only one pooled sample of wheat, at a total aflatoxin concentration of 0.003 mg kg-'. Ochratoxin A, sterigmatocystin and T-2 toxin were not detected. Higher concentrations of mycotoxins were found in the poorer grades of wheat.

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A survey for mycotoxins and fungal damage in maize (Zea mays L.) grown during 1982 in Far North Queensland is reported. This season had a rainfall distribution which was typical for the reglon. The 293 samples examined came from 11 1 farms in eight maize-growing districts. The samples were first subjected to rapid screening tests for fungal damage. Aflatoxins B1, B2, G1, G2 ochratoxin A, T-2 toxin, and sterigmatocystin were not detected, but zearalenone was found in 85% of the samples. The concentrations of zearalenone were correlated with the extent of Gibberella zeae cob rot as indicated by the proportion (up to 2%) of kernels in each sample having a reddish-purple discoloration. In four samples the zearalenone concentration exceeded 1 mg kg-1, but the mean ¦ s.d. (n = 293) concentration in all samples was 0.17 ¦ 0.225 mg kg-1. Concentrations were highest in districts with the highest rainfall during the period of maize growth.

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Weaner pigs on a farm near Beaudesert in south eastern Queensland refused to eat feed comprised largely of wheat and barley. Older pigs consumed small amounts and some prepubertal gilts subsequently displayed enlarged and reddened vulvas. Wheat, barley and triticale were grown on the farm during 1983, which was unusually and persistently wet. The wheat and triticale were harvested and stored for about 3 weeks with moisture contents above 14% before being fed. Samples of the wheat and triticale contained pale pink grains, which can indicate infection by the fungus Fusariurn grarninearurn Schw. On analysis 2 mycotoxins known to be produced by F. graminearurn were detected, deoxynivalenol (vomitoxin) which causes feed refusal and vomiting, and zearalenone which causes oestrogenic effects. Concentrations of deoxynivalenol in the wheat, triticale and barley were 34, 10, and <0.1 mg/kg respectively. Concentrations of zearalenone were 6.2, 2.8 and 0.1 mg/kg respectively. Subsequently, F. grarninearurn was isolated from grains and crop residues. Although the wet weather contributed to F. grarninearurn infection of the crops before harvest, most of the toxins probably developed during storage.

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Mycotoxicosis due to ingestion of zearalenone was detected on 2 pig farms on the Atherton Tableland in northern Queensland. In one herd of 200 pigs, this resulted from feeding maize which had been stored with a high moisture content. In the other herd of 1400 pigs, it resulted from feeding sorghum grain which was rain affected before harvest. Concentrations of zearalenone in the feeds ranged up to 8 mg/kg. Most prepubertal gilts in the herds displayed enlarged teats and signs of oestrus such as having red, swollen vulvas. In several cases both rectal and vaginal prolapses occurred. On one of the farms, 25 pigs died as a direct result of prolapses. Autopsy of a 3-monthold gilt revealed apparently enlarged ovaries and uterine horns. Sows and boars seemed to be unaffected. Four gilts failed to conceive following mating during the period of zearalenone ingestion, but apart from this and the deaths from prolapses, production of the herds appeared ti be unaffected.

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Five cases of aflatoxicosis in pigs in southern Queensland are described. One peracute case where aflatoxin concentrations of up to 5000pg aflatoxin B,/kg were demonstrated in stomach contents was presumed to be caused by consumption of mouldy bread. High levels of toxins were also present in the livers. Two cases of acute toxicity were caused by feeding mouldy peanut screenings containing 22000~9 aflatoxin B,/kg. One case of subacute and one of chronic toxicity were caused by sorghum grain based rations with lower aflatoxin levels (4640 and 255 pg/kg). Peracute toxicity caused collapse and deaths within several hours, acute toxicity caused deaths within 12 h and with subacute toxicity deaths occured after 3 weeks on a toxic ration. Anorexia and ill thrift affecting only growing animals were seen with chronic toxicity. Extensive centrilobular liver necrosis and haemorrhage occured with peracute toxicity and in cases of acute poisoning there was hepatic centrilobular cellular infiltration, hepatocyte swelling and bile stasis. With subacute toxicity hepatocyte vacuolation together with bile stasis and bile ductule hyperplasia were seen.

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Solvent extracts of cultures of the fungus Paecilomyces varioti are toxic to sheep blowfly, Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae). Different components of the culture extracts were isolated and bioassayed with L. cuprina. The component with most toxicity was purified and identified from its proton magnetic resonance spectrum as viriditoxin, a known antibiotic metabolite of the fungus. The insecticidal properties of viriditoxin were then evaluated. Mean LCso values for first instar larvae of organophosphate susceptible and resistant strains of L. cuprina were 7.5 and 8.4 ppm respectively. Pilot implant trials in sheep demonstrated that the compound provided protection for 9-17 weeks against both strains of L. cuprina. No adverse effects on the trial sheep were detected.

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In a series of experiments conducted in stone fruit orchards in southern Australia, water-based funnel-type traps baited with synthetic aggregation pheromone and fermenting bread dough, trapped 3- to 7-fold as many Carpophihus beetles (primarily C. dauidsoni) than wind-oriented pipe traps or dry funnel traps. The efficacy of dry funnel traps but not pipe traps, appeared to be improved by using water-filled collecting bottles. The potential for using water-based funnel traps in population suppression of Carpophilus spp. in stone fruit orchards through mass trapping is discussed.

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An apparatus is described that facilitates the determination of incorporation levels of isotope labelled, gaseous precursors into volatile insect-derived metabolites. Atmospheres of varying gas compositions can be generated by evacuation of a working chamber followed by admission of the required levels of component gases, using a precision, digitised pressure read-out system. Insects such as fruit-flies are located initially in a small introduction chamber, from which migration can occur downwards into the working chamber. The level of incorporation of labelled precursors is continuously assayed by the Solid Phase Micro Extraction (SPME) technique and GC-MS analyses. Experiments with both Bactrocera species (fruit-flies) and a parasitoid wasp, Megarhyssa nortoni nortoni (Cresson) and oxygen-18 labelled dioxygen illustrate the utility of this system. The isotope effects of oxygen-18 on the carbon-13 NMR spectra of 1,7- dioxaspiro[5,5]undecane are also described.

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We determined the quantity and chemical composition of cuticular hydrocarbons of different strains, sex and age of buffalo flies, Haematobia exigua. The quantity of cuticular hydrocarbons increased from less than 1 µg/fly for newly-emerged flies to over 11 µg/fly in 13 d-old flies. The hydrocarbon chain length varied from C21 to C29, with unbranched alkanes and monounsaturated alkenes the major components. Newly emerged flies produced almost exclusively C27 hydrocarbons. Increasing age was accompanied by the appearance of hydrocarbons with shorter carbon chains and an increase in the proportion of alkenes. 11 Tricosene and 7-tricosene were the most abundant hydrocarbons in mature buffalo flies. Cuticular hydrocarbons of buffalo flies are distinctly different from those of horn flies. The most noticeable differences were in the C23 alkenes, with the major isomers 11- and 7-tricosene in buffalo flies and (Z)-9- and (Z)-5-tricosene in horn flies, respectively. Cuticular hydrocarbon analysis provides a reliable method to differentiate buffalo and horn fly, which are difficult to separate morphologically. The differences in cuticular hydrocarbons also support their recognition as separate species, H. exigua and H. irritans, rather than as subspecies.

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We evaluated serum cationic trypsinogen as a marker of exocrine pancreatic function in children without cystic fibrosis. The ability of this test to determine steatorrhoea of pancreatic origin, and its relationship to a wide range of exocrine pancreatic function were assessed. Serum trypsinogen was measured in 32 children with steatorrhoea, 10 with pancreatic and 22 with non-pancreatic causes. In patients with pancreatic steatorrhoea, serum cationic trypsinogen was 4·9±4·9 μg/l (mean ±SD), significantly below values in patients with non-pancreatic steatorrhoea (47·0±22·1 μg/l, p<0·001) and 50 control subjects (31·4±7·4 μg/l, p<0·001). Serum cationic trypsinogen values in patients with pancreatic steatorrhoea all fell below the lower limit of our control range and below all values for patients with non-pancreatic steatorrhoea. Serum cationic trypsinogen was also evaluated against pancreatic trypsin output in 47 patients (range 0·2-17·0 yr) who underwent a hormonal pancreatic stimulation test. In 17 patients, serum cationic trypsinogen was low (<-2SD or 16·6 μg/l), and associated with greatly impaired pancreatic trypsin output, ranging from 0-8% of mean normal trypsin output. Five of these 17 patients did not have steatorrhoea. In 30 patients with normal or raised serum cationic trypsinogen (≥16·6 μg/l), pancreatic trypsin output ranged from 15-183% of mean normal values. In conclusion, low serum cationic trypsinogen suggests severely impaired exocrine pancreatic function, with sensitivity extending above the steatorrhoeic threshold. In the presence of steatorrhoea, low serum cationic trypsinogen indicates a pancreatic aetiology. Normal serum cationic trypsinogen, however, does not exclude impaired pancreatic function, above the steatorrhoeic threshold.

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Serum immunoreactive cationic trypsinogen levels were determined in 99 control subjects and 381 cystic fibrosis (CF) patients. To evaluate the status of the exocrine pancreas all CF patients had previously undergone fecal fat balance studies and/or pancreatic stimulation tests. Three hundred fourteen CF patients had fat malabsorption and/or had inadequate pancreatic enzyme secretion (pancreatic insufficiency) requiring oral pancreatic enzyme supplements with meals. Sixty-seven CF patients did not have fat malabsorption and/or had adequate enzyme secretion (pancreatic sufficiency) and were not receiving pancreatic enzyme supplements with meals. Mean serum trypsinogen in 99 control subjects was 31.4 ± 14.8 /µg/hter (± 2 SD) and levels did not vary with age or sex. In CF infants (< 2 yr) with pancreatic insufficiency, mean serum trypsinogen was significantly above the non-CF values (p < 0.001). Ninety-one percent of the CF infants had elevated levels. Serum trypsinogen values in the pancreatic insuffi ient group declined steeply up to 5 years, reaching subnormal values by age 6. An equation was developed which described these age-related changes very accurately. Only six CF patients with pancreatic insufficiency had serum trypsinogen levels above the 95% confidence limits of this equation. In contrast, there was no age related decline in serum trypsinogen among the CF group with pancreatic sufficiency. Under 7 yr, serum trypsinogen failed to distinguish the two groups. In those over 7 yr of age, however, serum trypsinogen was significantly higher than the CF group with pancreatic insufficiency (p < 0.001), and 93% had values within or above the control range. In conclusion, serum trypsinogen appears to be a useful screening test for CF in infancy. Between 2 and 7 yr of age this test is of little diagnostic value. After 7 yr of age, serum trypsinogen can reliably distinguish between CF patients with and without pancreatic insufficiency.

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Jakke Holvas: A Critique of the Metaphysics of Economy The research problem of this dissertation is the commonly held opinion according to which everything has become a question of economy in the present day. Economy legitimates and justifies. In this study, the pattern of thinking and conceptualizing in which economy figures as the ultimate reason is called the metaphysics of economy. The defining characteristic of the metaphysics of economy is its failure to recognize non-economic rules, ethics, or ways of existence. The sources included in the study cover certain classics of philosophy (Plato, Aristotle, Friedrich Nietzsche) and sociology (Karl Marx, Max Weber, Marcel Mauss), as well as the more recent French social theory (Jean Baudrillard, Michel Foucault). The research methods used are textual analysis and evaluation of concepts by means of historical comparison. The background to the study is given by the views of historians and sociologists according to whom traditional forms have ceased to exist and the market economy become established as the western system of values. The study identifies points of transition from the traditional forms to economic values. In addition, the dissertation focuses on the modern non-economic forms. The study examines the economic and ethical meanings of gift in antiquity in Homer, Plato, and Aristotle. Following Marcel Mauss, the study analyzes the forms and principles of gift exchange. The study also applies Nietzsche’s philosophy to evaluate under what conditions giving a gift becomes an act of exercising power that puts its receiver into debt. The conclusion of the study is that the classics of philosophy and sociology can rightly be interpreted in terms of the metaphysics of economy, but they also offer grounds for criticizing this metaphysics, even alternatives. One such alternative is non-economic archaic ethic. The study delineates a duality between economy and non-economy as well as creating concepts which could be used in the future to critically analyze economy from a position external to the economic system of concepts.