Use of products of straw decomposition by N2-fixing (C2H2-reducing) populations of bacteria in three soils from wheat-growing areas

1986 ◽  
Vol 37 (1) ◽  
pp. 1 ◽  
Author(s):  
MM Roper ◽  
DM Halsall

The potential for N2 fixation by free-living bacteria using straw as a source of energy was evaluated in three soils (one from Gunnedah and two from Cowra) representative of the wheat belt in New South Wales. All three soils had a history of straw incorporation. The abilities of the respective microbial populations to use a range of carbon sources, including potential products of decomposition of straw, was determined and compared with the size and composition of each population. Neutral to alkaline (pH 7.4) soil of high (51%) clay content from Gunnedah produced higher rates of nitrogenase activity with straw than more acid (pH 5.6) lower (17%) clay containing soil from Cowra (site B). Gunnedah soil also contained a larger population of N2-fixing bacteria which used a broader range of energy sources than soil from either Cowra site B or Cowra site W (pH 5.8, clay content 34%). There was little difference in the composition of the N2-fixing populations in each of the soils except that Azotobacter spp. were absent from the acid Cowra soils. It was concluded that the difference in behaviour of the respective N2-fixing populations was primarily due to the physical characteristics of the soil affecting the numbers and activities of diazotrophic microorganisms. In addition some soil environments failed to support specific organisms.

1983 ◽  
Vol 34 (6) ◽  
pp. 725 ◽  
Author(s):  
MM Roper

Nitrogenase activity and decomposition of straw were examined in situ in two areas (Gunnedah and Cowra) representative of large areas of the New South Wales wheat belt. Measurements of nitrogenase activity were made by adapting the acetylene reduction assay for use in the field. Evolution of CO2 was monitored as an indirect measure of decomposition of straw. The addition of straw to soil stimulated nitrogenase activity which was related to the amount of straw added and the rate of straw decomposition. There were significant levels of activity provided the soil was moist and warm. Nitrogenase activity increased with mean daily soil temperature (up to at least 30�C) and decreased as the soil dried from field capacity. It is concluded that nitrogen fixation by free-living nitrogen-fixing microorganisms in soils amended with straw may contribute to the nitrogen status of the soil and thus reduce the need for nitrogen fertilizers.


1992 ◽  
Vol 40 (3) ◽  
pp. 279 ◽  
Author(s):  
IR Wallis ◽  
B Green

Water flux and field metabolic rate (FMR) were measured by the doubly labelled water (DLW) method in free-living male and female rufous rat-kangaroos Aepyprymnus rufescens near Drake in northern New South Wales. The mean FMR of 499 kJ kg-1 day-1 was similar in winter and summer even though the difference in mean minimum temperatures between the two seasons was 20-degrees-C. Furthermore, we did not find any differences in FMR between males and females even though several females carried large pouch young or had young-at-foot. A poor understanding of the diet and the behavioural ecology of A. rufescens makes ft difficult to explain the similarities between sexes and seasons.


2017 ◽  
Vol 52 (6) ◽  
pp. 530-541 ◽  
Author(s):  
Melissa J Green ◽  
Stacy Tzoumakis ◽  
Kristin R Laurens ◽  
Kimberlie Dean ◽  
Maina Kariuki ◽  
...  

Objective: Detecting the early emergence of childhood risk for adult mental disorders may lead to interventions for reducing subsequent burden of these disorders. We set out to determine classes of children who may be at risk for later mental disorder on the basis of early patterns of development in a population cohort, and associated exposures gleaned from linked administrative records obtained within the New South Wales Child Development Study. Methods: Intergenerational records from government departments of health, education, justice and child protection were linked with the Australian Early Development Census for a state population cohort of 67,353 children approximately 5 years of age. We used binary data from 16 subdomains of the Australian Early Development Census to determine classes of children with shared patterns of Australian Early Development Census–defined vulnerability using latent class analysis. Covariates, which included demographic features (sex, socioeconomic status) and exposure to child maltreatment, parental mental illness, parental criminal offending and perinatal adversities (i.e. birth complications, smoking during pregnancy, low birth weight), were examined hierarchically within latent class analysis models. Results: Four classes were identified, reflecting putative risk states for mental disorders: (1) disrespectful and aggressive/hyperactive behaviour, labelled ‘misconduct risk’ ( N = 4368; 6.5%); (2) ‘pervasive risk’ ( N = 2668; 4.0%); (3) ‘mild generalised risk’ ( N = 7822; 11.6%); and (4) ‘no risk’ ( N = 52,495; 77.9%). The odds of membership in putative risk groups (relative to the no risk group) were greater among children from backgrounds of child maltreatment, parental history of mental illness, parental history of criminal offending, socioeconomic disadvantage and perinatal adversities, with distinguishable patterns of association for some covariates. Conclusion: Patterns of early childhood developmental vulnerabilities may provide useful indicators for particular mental disorder outcomes in later life, although their predictive utility in this respect remains to be established in longitudinal follow-up of the cohort.


2011 ◽  
Vol 16 (4) ◽  
pp. 439-457 ◽  
Author(s):  
Lee C. Moerman ◽  
Sandra L. van der Laan

This paper documents the history of paternalistic state policies and the effects of asbestos mining on the Indigenous community at Baryulgil in northern New South Wales. Despite the lack of profitability, the asbestos operations continued for over 30 years leaving a legacy of asbestos-related health and environmental issues. The shift of responsibility for Indigenous welfare from the State to a corporate entity is evidenced in this historical study using the lens of historical institutionalism. The Baryulgil case is instructive in a number of ways: it demonstrates the subtlety with which human rights abuses can occur in an environment where paternalistic attitudes towards Indigenous peoples prevail; it demonstrates the clash between pursuit of corporate objectives and human rights; and finally it demonstrates the lack of corporate accountability in the asbestos industry.


Zootaxa ◽  
2021 ◽  
Vol 5024 (1) ◽  
pp. 1-63
Author(s):  
JORGE RODRÍGUEZ ◽  
PAT A. HUTCHINGS ◽  
JANE E. WILLIAMSON

Flatworms of the Order Polycladida are a group of free-living invertebrates found in a diversity of marine habitats, with over 800 species described worldwide. Marine flatworms are a conspicuous component of Australia’s marine fauna yet have received little attention. Less than 30 scientific articles have been published on Australian marine flatworms since 1855, of which only nine include species from southeastern Australia. Here, the biodiversity and distribution of species belonging to the Order Polycladida inhabiting intertidal rocky beaches in southeastern Australian waters were identified and analysed. Sampling was conducted at low tide along the coasts of New South Wales and Victoria. Collected samples were serially sectioned for comparative anatomical studies, and tissue was removed from each individual for molecular sequencing and analyses. Both nuclear and mitochondrial DNA sequences were obtained and used as an additional source of evidence for the description of new species as well as providing further insight into the phylogenetic relationships between them. A total of 20 species, six of which are new (e.g., Eulatocestus australis sp. nov.), and a new genus (Parabolia gen. nov.) have been described, as well as two new records for Australia (e.g., Stylochoplana clara Kato, 1937) have been identified increasing our knowledge of this important component of the Australian marine biota.  


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