84 resultados para Period of harvesting


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The option for biological nitrogen removal has recently been broadened with the description of simultaneous nitrification/denitrification, anaerobic ammonium oxidation (ANAMMOX) and the concept of CANON (completely autotrophic nitrogen removal over nitrite). An autotrophic anaerobic ammonium oxidation (AAAO) consortium was successfully selected and enriched from municipal treatment plant sludges in Sydney, Australia, but not from industrial coke-oven wastewater sludges. Chemolithoautotrophic basic salt (CLABS) medium was used in the selection of AAAO organisms and chloramphenicol was added to the initial stage of selection to eliminate denitrifiers. Two different temperatures, 37degreesC and 55degreesC, were used in the selection of mesophilic and thermophilic consortia, respectively. Thermophilic AAAO organisms were not selected at 55degreesC. Mesophilic AAAO activities, however, were evident in both batch and continuous cultures, whereby ammonium was consumed concurrently with a decrease of nitrite, giving a ratio of 1:1-1:1.3 in ammonium removal rate over nitrite consumption rate. A continuous-mode mesophilic fixed-bed reactor was established to enrich the AAAO consortium. After 1 year, biofilms, pinkish in color, had developed on the support media and side wall of the feed-line tubing. Ammonium and nitrite consumption increased from similar to15 mg to 60 mg d(-1) L-1 over a period of 243 days. Later, transmission electron microscopy (TEM) and fluorescence in situ hybridization (FISH) techniques revealed that the dominant cell type in the AAAO consortium had a similar morphology and 16S rDNA sequence homology to that of the recently described ANAMMOX organism, Brocadia anammoxidans.

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Background Twin and family studies have shown that genetic effects explain a relatively high amount of the phenotypic variation in blood pressure. However, many studies have not been able to replicate findings of association between specific polymorphisms and diastolic and systolic blood pressure. Methods In a structural equation-modelling framework the authors investigated longitudinal changes in repeated measures of blood pressures in a sample of 298 like-sexed twin pairs from the population-based Swedish Twin Registry. Also examined was the association between blood pressure and polymorphisms in the angiotensin-I converting enzyme and the angiotensin 11 receptor type 1 with the 'Fulker' test Both linkage and association were tested simultaneously revealing whether the polymorphism is a Quantitative Trait Locus (QTL) or in linkage disequilibrium with the QTL. Results Genetic influences explained up to 46% of the phenotypic variance in diastolic and 63% of the phenotypic variance in systolic blood pressure. Genetic influences were stable over time and contributed up to 78% of the phenotypic correlation in both diastolic and systolic blood pressure. Non-shared environmental effects were characterised by time specific influences and little transmission from one time point to the next. There was no significant linkage and association between the polymorphisms and blood pressure. Conclusions There is a considerable genetic stability in both diastolic and systolic blood pressure for a 6-year period of time in adult life. Non-shared environmental influences have a small long-term effect Although associations with the polymorphisms could not be replicated, results should be interpreted with caution due to power considerations. (C) 2002 Lippincott Williams Wilkins.

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Free-ranging koalas (Phascolarctos cinereus) were monitored by means of radio-relocation in the area of Blair Athol Coal Mine and surrounding properties. Daytime tree use, home range and diet of these koalas was determined in spring and autumn, as was the leaf moisture composition of potential fodder species. Koalas used on average 93 (male koalas) and 56 (female koalas) trees during the period of observation, occupying home ranges of 135 and 101 ha respectively. Mean sightings per tree were 1.19 for both males and females and home-range sizes were not significantly different between sexes or seasons. Koalas were observed returning to previously used daytime roosting trees infrequently (

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The Green-striped burrowing frog. Cyclorana alboguttata survives extended drought periods by burrowing underground and aestivating. These frogs remain immobile within cocoons of shed skin and Mucus during aestivation and emerge from their burrows upon heavy rains to feed and reproduce. Extended periods of immobilisation in mammals typically result in muscle atrophy and a decrease in muscle performance. We examined the effect of aestivation and hence prolonged immobilisation, on skeletal Muscle mass. in vitro muscle performance, and locomotor performance in C. alboguttata. Frogs were aestivated in soil for 3 months and were compared with control animals that remained active, were fed, and had a continual supply of water. Compared to the controls, the wet mass of the gastrocnemius. sartorius, gracilus major. semimembranosus. peroneus, extensor cruris, tibialis posticus and tibialis anticus longus of aestivators remained unchanged indicating no muscle atrophy. The in-vitro performance characteristics of the gastroenemius muscle were maintained and burst swimming speed Was Unaffected, requiring no recovery from the extended period of immobilisation associated with aestivation. This preservation of muscle size, contractile condition and locomotor performance through aestivation enables C. alboguttata to compress their life history into unpredictable windows of opportunity, whenever heavy rains occur.

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The phylogenetic relationships amongst 29 species of Carlia and Lygisaurus were estimated using a 726-base-pair segment of the protein-coding mitochondrial ND4 gene. Results do not support the recent resurrection of the genus Lygisaurus. Although most Lygisaurus species formed a single clade, this clade is nested within Carlia and includes Carlia parrhasius. Due to this new molecular evidence, and the paucity of diagnostic morphological characters separating the genera, Lygisaurus de Vis 1884 is re-synonymised with Carlia Gray 1845. Our analysis is also inconsistent with a previous suggestion that Lygisaurus timlowi should be removed to Menetia, a genus that is distantly related relative to outgroups used here. Intraspecific variation in Carlia is, in several instances, greater than interspecific distance. The most strikingly divergent lineages are found within C. rubrigularis, which appears to be paraphyletic, with southern populations more closely related to C. rhomboidalis than to northern populations of C. rubrigularis. The two C. rubrigularis-C. rhomboidalis lineages form part of a major polytomy at an intermediate level of divergence. Lack of resolution at this level, however, does not appear to be due to saturation or loss of phylogenetic signal. Rather, the polytomy probably reflects a period of relatively rapid diversification that occurred sometime during the Miocene.

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Study Design. A cross-sectional case-control study. Objectives. To examine the effect of fatigue on torque output as well as electromyographic frequency and amplitude values of trunk muscles during isometric axial rotation exertion in back pain patients and to compare the results with a matched control group. Summary of Background Data. Back pain patients exhibited different activation strategies in trunk muscles during the axial rotation exertions. Fatigue changes of abdominal and back muscles during axial rotation exertion have not been examined in patients with back pain. Methods. Twelve back pain patients and 12 matched controls performed isometric fatiguing axial rotation to both sides at 80% maximum voluntary contraction in a standing position. During the fatiguing exertion, electromyographic changes of rectus abdominis, external oblique, internal oblique, latissimus dorsi, iliocostalis lumborum, and multifidus were recorded bilaterally. The primary torque in the transverse plane and the coupling torques in sagittal and coronal planes were also measured. Results. No difference in the endurance capacity was found between back pain and control groups. At the initial period of the exertion, back pain patients demonstrated a statistical trend (P = 0.058) of greater sagittal coupling torque as well as lower activity of rectus abdominis and multifidus and higher activity in external oblique. During the fatigue process similar changes of coupling torque were demonstrated in both sagittal and coronal planes, but a smaller fatigue rate for right external oblique, increase in median frequency for latissimus dorsi, and lesser increase in activity for back muscles were found in the back pain group compared with the control group. Conclusions. Alterations in electromyographic activation and fatigue rates of abdominal and back muscles demonstrated during the fatigue process provide insights into the muscle dysfunctions in back pain and may help clinicians to devise more rational treatment strategies.

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The black flying fox Pteropus alecto is one of four species of flying fox found on the Australian mainland. Little information exists about the specific behaviour of this species, and no framework for the study of its behaviour has yet been constructed. In the study reported here, two P alecto colonies were observed at two day roosts in South East Queensland, Australia, between 1998-2000. Observations focused on solitary and social actions in general and on mother-infant interactions in some detail and led to the construction of an ethogram that defines each action structurally and functionally, describing accompanying vocalisations where appropriate. Diurnal activity patterns of P. alecto throughout the year consisted predominantly of roosting, grooming and sleeping, and involved little social activity. Social interactions were largely restricted to the seasonal contexts of the birthing/rearing period of October to March and the subsequent courtship/mating season of February to April. In all, 74 behavioural units were defined with the aim of facilitating further research and the implementation of effective conservation strategies for the species.

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The neurexins are a large family of neuronal cell-surface proteins believed to be involved in intercellular signalling and the formation of intercellular junctions. To begin to assess the role of these proteins in the olfactory bulb, we describe here the expression patterns of their transmembrane and secreted ligands, the neuroligins and neurexophilins, during both embryonic and postnatal development. In situ hybridisation showed that neuroligin 1 and 2 were expressed by second order mitral cells during early postnatal development but not in adults. The secreted ligand for a-neurexin, neurexophilin 1, was also expressed in the postnatal olfactory bulb. Neurexophilin 1 was detected in only periglomerular cells during the early postnatal period of glomerular formation but later was also expressed in mitral cells. These results suggest that neurexin-ligand interactions may be important for development and/or maturation of synaptic connections in the primary olfactory pathway.

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Background and Purpose Previous research regarding the symmetry of trans-tibial amputees has examined weight distribution and various gait parameters between prosthetic and sound limbs. However, to date, no known research has determined if asymmetry is present in the strength of the hip abductor muscles or if correlations exist between these categories of symmetry. The purpose of the present study was, therefore, to document asymmetry present in stance, strength and gait measures, and to determine the relationship between these variables. Method Twenty-three elderly, unilateral trans-tibial amputees stood on two adjacent forceplates whilst the weight distribution and standard deviation (SD) of the anterior-posterior and the medio-lateral centre of pressure excursion (COPE) under each limb was recorded during four 40 s trials: quiet stance (QS), with eyes open and eyes closed; and even stance (ES), with eyes open and eyes closed. Gait measures (velocity, cadence, step and stride lengths, stance:swing ratio and period of double support) over 10 m of fast, yet safe walking and measures of the strength of hip abductor muscles were also obtained by use of a stride analyser and a dynamometer, respectively. Results No significant differences were found between QS and ES measures. However, significantly more weight was taken on the sound limb than on the amputated limb. Notably, more anterior-posterior movement occurred under the sound limb than the amputated limb, with this becoming more apparent with the eyes closed. Movement in the medio-lateral direction was found to be the same between sides. No differences in muscle strength or gait measures between limbs were demonstrated. However. strong hip abductor muscles were correlated with increased weight-bearing on the amputated limb, improved gait parameters and reduced medio-lateral COPE under the amputated limb. Conclusions This research confirms the asymmetrical nature of amputee stance and demonstrates symmetry of strength and gait measures between limbs. The correlations between hip abductor muscle strength, weight distribution and gait measures illustrates the importance of pre- and postoperative training of these muscles. Copyright © 2002 Whurr Publishers Ltd.

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The eastern shovelnose ray, Aptychotrema rostrata (Rhinobatidae), is an endemic batoid common to the east coast of Australia. The reproductive cycle was studied in Moreton Bay, south-eastern Queensland, over a 14-month period. Aptychotrema rostrata is an aplacental yolksac viviparous species with an annual, seasonal reproductive cycle in Moreton Bay. Females mature at 54-66 cm total length, and males at 60-68 cm total length. Gravid females were observed during September-November and parturition occurred in November-December. Vitellogenesis does not proceed in parallel with gestation. Ovulation and copulation probably occur during July-September, resulting in a gestational period of 3-5 months. Uterine fecundity ranges from 4 to 18, with a significant positive relationship between uterine fecundity and maternal body length. In mature males, a peak in the proportion of mature spermatocysts in the testes was observed in July, whereas gonadosomatic index peaked in April.

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Government policy change to self detennination over the past two decades has gradually given rise to various structures of Indigenous self government across Australia. Indigenous Local Government Authorities (LGAs) are the governing structure which receive the greatest devolution of State authority, especially those found in Queensland and the Northern Territory. Their statutory basis has developed over a relatively short period of time and is still very much evolving. This paper explores what opportunities exist for Indigenous LGAs to adopt statutory planning mechanisms.

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This research monograph seeks, as the author puts it, ‘to demonstrate the utility of ethnographic research methods to industrial relations in the developing world’. To this end, the author provides case studies of two lock factories in the West Midlands of England, with data sourced from interviews and observations by the author during a period of two decades in the case of one, and a rather shorter period in the case of the other. The insights gleaned from these two case studies are then considered in the light of the ethnographic literature on industrial relations in the developing world. The body of the book comprises three main chapters which successively examine the issues of paternalism, gender and family, and collective action in the two factories.

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We present the first mathematical model on the transmission dynamics of Schistosoma japonicum. The work extends Barbour's classic model of schistosome transmission. It allows for the mammalian host heterogeneity characteristic of the S. japonicum life cycle, and solves the problem of under-specification of Barbour's model by the use of Chinese data we are collecting on human-bovine transmission in the Poyang Lake area of Jiangxi Province in China. The model predicts that in the lake/marshland areas of the Yangtze River basin: (1) once-early mass chemotherapy of humans is little better than twice-yearly mass chemotherapy in reducing human prevalence. Depending on the heterogeneity of prevalence within the population, targeted treatment of high prevalence groups, with lower overall coverage, can be more effective than mass treatment with higher overall coverage. Treatment confers a short term benefit only, with prevalence rising to endemic levels once chemotherapy programs are stopped (2) depending on the relative contributions of bovines and humans, bovine treatment can benefit humans almost as much as human treatment. Like human treatment, bovine treatment confers a short-term benefit. A combination of human and bovine treatment will dramatically reduce human prevalence and maintains the reduction for a longer period of time than treatment of a single host, although human prevalence rises once treatment ceases; (3) assuming 75% coverage of bovines, a bovine vaccine which acts on worm fecundity must have about 75% efficacy to reduce the reproduction rate below one and ensure mid-term reduction and long-term elimination of the parasite. Such a vaccination program should be accompanied by an initial period of human treatment to instigate a short-term reduction in prevalence, following which the reduction is enhanced by vaccine effects; (4) if the bovine vaccine is only 45% efficacious (the level of current prototype vaccines) it will lower the endemic prevalence, but will not result in elimination. If it is accompanied by an initial period of human treatment and by a 45% improvement in human sanitation or a 30% reduction in contaminated water contact by humans, elimination is then possible. (C) 2002 Elsevier Science B.V. All rights reserved.

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Background/Aims: These studies investigated the role of apoptosis following ischaemia/reperfusion (I/R) injury to the liver and the effect of pretreatment with Cyclosporin A. Methods: Male Sprague-Dawley rats received 30 min of warm ischaemia followed by a period of reperfusion of 6 h. Rats were given olive oil or Cyclosporin A (30 mg/kg p.o.) the day before surgery. Neutrophil numbers were assessed in haematoxylin-eosin-stained sections of liver. In situ staining of sections using TdT-mediated dUTP-fluoreseein nick-end labelling was carried out to determine the extent of apoptosis, followed by electron microscopy. Semi-quantitative polymerase chain reaction (PCR) analysis of the transcript for Fas antigen was performed. Results and Conclusions: High levels of apoptosis were observed in I/R injury, which were greatly ameliorated in Cyclosporin A-pretreated groups. PCR analysis indicated a reduction in the level of expression of Fas transcript in Cyclosporin A-treated rats. Histological analysis showed a significant increase in the number of neutrophils infiltrating I/R-injured tissue (62 +/- 10.69, it = 16), which was markedly reduced by Cyclosporin A pretreatment (16 +/- 7, n = 6, P < 0.05). These results indicate a role of parenchymal apoptosis in the pathogenesis of I/R injury, which occurs in association with neutrophil infiltration, both of which can be significantly reduced by Cyclosporin A pretreatment. (C) 2002 European Association for the Study of the Liver. Published by Elsevier Science B.V. All rights reserved.

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The compound Zr0.75Ce0.08Nd0.17O1.92 was investigated as part of a much larger electrical conductivity/microstructure study of the systems ZrO2-CeO2-M2O3 (where M=Nd, Sm, ..., Yb) [Solid State Ionics (2002)]. Electrical conductivity measurements performed in air at 800 degreesC showed significant conductivity degradation over a period of 200 h. Investigation of the annealed and as-fired specimens by ATEM revealed the presence of an emerging, ordered pyrochlore-type phase within the Zr0.75Ce0.08Nd0.17O1.92 defect-fluorite solid solution at much lower dopant levels than observed previously for zirconia binary systems. (C) 2002 Elsevier Science B.V. All rights reserved.