Coupling of cellular processes and their coordinated oscillations under continuous light in Cyanothece sp. ATCC 51142, a diazotrophic unicellular cyanobacterium
Description:
In the last three decades or so there has been a significant increase in fodder trading, both in terms of the quantity of fodder traded and in terms of its economic value to the industry. Often, this fodder type may be supplied free of charge to graziers in distress due to circumstances that follow natural disasters such as bushfires, drought, and flood. However, because of the obvious urgency arising from these situations, it is suspected that much relief fodder may unintentionally pose an elevated risk for dispersal of weeds since it may be supplied from pasture not normally used for trade in fodder, and therefore is of unknown quality. Previous destructive method to detect weed propagules in bales of fodder are cumbersome, time consuming and of limited ecological and statistical value. Therefore, objective of this paper was to development of a convenient method to assess round pasture hay bales for the presence of weed propagules, to prevent unintentional spread of noxious species in hay bales. To examine this objective known quantity of seeds were added in a series of distributions to bales of seed free pasture hay, and a positive correlation for the amount of seed added per bale with that recovered in core samples was observed. Whilst the number of seeds detected per bale varied according to the distribution of seeds within the bales and the number of cores analysed, the absolute detection of seeds suggests that this sampling method is worthy of further examination. In addition, a pragmatic estimation of bale remnants after stock feeding has been investigated to more closely estimate the potential size of the remaining seed bank. The authors propose that development of this approach is timely, in the light of future climatic uncertainty driving extreme weather events that increase the need for relief fodder, which can be a potential vector for the spread of noxious weed seeds.
Description:
In the last three decades or so there has been a significant increase in fodder trading, both in terms of the quantity of fodder traded and in terms of its economic value to the industry. Often, this fodder type may be supplied free of charge to graziers in distress due to circumstances that follow natural disasters such as bushfires, drought, and flood. However, because of the obvious urgency arising from these situations, it is suspected that much relief fodder may unintentionally pose an elevated risk for dispersal of weeds since it may be supplied from pasture not normally used for trade in fodder, and therefore is of unknown quality. Previous destructive method to detect weed propagules in bales of fodder are cumbersome, time consuming and of limited ecological and statistical value. Therefore, objective of this paper was to development of a convenient method to assess round pasture hay bales for the presence of weed propagules, to prevent unintentional spread of noxious species in hay bales. To examine this objective known quantity of seeds were added in a series of distributions to bales of seed free pasture hay, and a positive correlation for the amount of seed added per bale with that recovered in core samples was observed. Whilst the number of seeds detected per bale varied according to the distribution of seeds within the bales and the number of cores analysed, the absolute detection of seeds suggests that this sampling method is worthy of further examination. In addition, a pragmatic estimation of bale remnants after stock feeding has been investigated to more closely estimate the potential size of the remaining seed bank. The authors propose that development of this approach is timely, in the light of future climatic uncertainty driving extreme weather events that increase the need for relief fodder, which can be a potential vector for the spread of noxious weed seeds.
Description:
The denaturation kinetics of whey protein isolate (WPI), in the presence and absence of lactose and trehalose, was quantified in a convective air-drying environment. Single droplets of WPI, WPI-lactose and WPI-trehalose were dried in conditioned air (2.5% RH, 0.5 m/s air velocity) at two temperatures (65°C and 80°C) for 500 s. The initial solid concentration of these solutions was 10% (w/v) in all the samples. Approximately 68% of WPI was denatured when it was dried in the absence of sugars. Addition of 20% trehalose prevented the irreversible denaturation of WPI at both temperatures. Thirty percent lactose was required to prevent denaturation of WPI at 65°C and the same amount of lactose protected only 70% of WPI from denaturation at 80°C. The secondary structures of WPI were found to be altered by the drying-induced stresses, even in the presence of 20% trehalose and 30% lactose.
Description:
The polygon-based scaled boundary finite element method is applied to two finite fracture mechanics based failure criteria to predict the crack initiation from stress concentrations, i.e. notches and holes. The stress and displacement fields are modelled by the scaled boundary finite element method through semi-analytical expressions that resemble asymptotic expansions around cracks and notches. Important fracture parameters, i.e. energy release rate and stress, are accurately and conveniently computed from the solutions of stresses and displacements via analytical integration. One distinguished advantage of applying the scaled boundary finite element method to finite fracture mechanics is that the required changes in the mesh are easily accommodated by shifting the crack tip within the cracked polygon without changing the global mesh structure. The developed framework is validated using four numerical examples. The crack initiation predictions obtained from the scaled boundary finite element method agree well with the reference finite element results.
Description:
Historical conditions in riparian systems can be derived from the recorded distribution of water plants and their ecological requirements. Herbarium and literature records were used to assess historical species occurrence, and a field survey and a seed-bank study were used to assess present-day occurrence in two adjacent, southern Australian catchments: the Angas River and the Tookayerta Creek. There was an increase in the proportion of salinity- and drought-tolerant species detected in the Angas River catchment since European settlement. Field-survey data and the seed-bank study data were similar for that catchment, indicating that the submerged flora of the Angas River catchment is resilient to drought. In contrast, the dissimilarity of the seed-bank study data and the survey data from the Tookayerta Creek catchment indicated that the submerged flora in that catchment is not tolerant of drought. Although submerged species in the Tookayerta Creek catchment are dependent on the presence of permanent fresh water, there were more salinity-tolerant species in the lower Tookayerta catchment in the present study than were detected in the past. Comparison of the historical plant distribution and present-day distribution in catchments can provide interpretation of environmental conditions and ecological filters now, and since European settlement.
Description:
This study investigates the influence of mixotrophy on physiology and metabolism by analysis of global gene expression in unicellular diazotrophic cyanobacterium Cyanothece sp. ATCC 51142 ( henceforth Cyanothece 51142). It was found that Cyanothece 51142 continues to oscillate between photosynthesis and respiration in continuous light under mixotrophy with cycle time of similar to 13 h. Mixotrophy is marked by an extended respiratory phase compared with photoautotrophy. It can be argued that glycerol provides supplementary energy for nitrogen fixation, which is derived primarily from the glycogen reserves during photoautotrophy. The genes of NDH complex, cytochrome c oxidase and ATP synthase are significantly overexpressed in mixotrophy during the day compared to autotrophy with synchronous expression of the bidirectional hydrogenase genes possibly to maintain redox balance. However, nitrogenase complex remains exclusive to nighttime metabolism concomitantly with uptake hydrogenase. This study throws light on interrelations between metabolic pathways with implications in design of hydrogen producer strains. (C) 2015 Elsevier Ltd. All rights reserved.
Description:
A new genus and species of the silverfish subfamily Ctenolepismatinae and the first endemic species of the Lepismatinae are described from Queensland. A single male specimen of Qantelsella louisae n.gen., n.sp., was collected from dry leaf litter in Bladensburg National Park near Winton. Xenolepisma monteithi n.sp. is known from one adult female and two juvenile specimens collected with ants (Crematogaster sp.) from the bark of a tree on the Cape York Peninsula. This genus is also known from southern Africa, India and Malaysia and the diagnosis of the genus is emended to include the morphological differences exhibited by the Australian species.
Description:
Impulsivity is a factor that has been linked strongly to problem gambling; however, conceptualization problems have impeded research in this area. Research suggests that there may be as many as five impulsivity subtypes and that some but not all of these subtypes are involved in problem gambling. This cross-sectional and correlational study used the multifaceted UPPS-P Impulsive Behaviour Scale as a predictor of problem gambling in a community (N= 200) sample of Australian adult gamblers. Of the five impulsivity subtypes, negative urgency, positive urgency and sensation seeking were found to be positively related to problem gambling, while lack of premeditation and lack of perseverance were unrelated. Multiple regression analyses revealed that positive urgency and negative urgency were the only significant predictors of problem gambling, suggesting that individuals who have the tendency to act rashly when in a positive or negative mood are more likely to display problem gambling behaviour. The results provide further evidence of the significant role of strong emotions in problem gambling. Further, it appears that problem gambling can be motivated both by the impulsive desire to avoid negative mood states and by the impulsive desire to maintain and enhance positive mood states.
Description:
The concepts of ecosystem regime shifts, thresholds and alternative or multiple stable states are used extensively in the ecological and environmental management literature. When applied to aquatic ecosystems, these terms are used inconsistently reflecting differing levels of supporting evidence among ecosystem types. Although many aquatic ecosystems around the world have become degraded, the magnitude and causes of changes, relative to the range of historical variability, are poorly known. A working group supported by the Australian Centre for Ecological Analysis and Synthesis (ACEAS) reviewed 135 papers on freshwater ecosystems to assess the evidence for pressure-induced non-linear changes in freshwater ecosystems; these papers used terms indicating sudden and non-linear change in their titles and key words, and so was a positively biased sample. We scrutinized papers for study context and methods, ecosystem characteristics and focus, types of pressures and ecological responses considered, and the type of change reported (i.e., gradual, non-linear, hysteretic or irreversible change). There was little empirical evidence for regime shifts and changes between multiple or alternative stable states in these studies although some shifts between turbid phytoplankton-dominated states and clear-water, macrophyte-dominated states were reported in shallow lakes in temperate climates. We found limited understanding of the subtleties of the relevant theoretical concepts and encountered few mechanistic studies that investigated or identified cause-and-effect relationships between ecological responses and nominal pressures. Our results mirror those of reviews for estuarine, nearshore and marine aquatic ecosystems, demonstrating that although the concepts of regime shifts and alternative stable states have become prominent in the scientific and management literature, their empirical underpinning is weak outside of a specific environmental setting. The application of these concepts in future research and management applications should include evidence on the mechanistic links between pressures and consequent ecological change. Explicit consideration should also be given to whether observed temporal dynamics represent variation along a continuum rather than categorically different states.
Description:
Traditional growth literature advocated the role of fiscal policy in establishing economic growth (Mckinnon, 1973; Schumpeter, 1911; Shaw, 1973; Solow, 1956; Zagler and Durnecker, 2003), but it did not consider the role of the stock market and the financial intermediation as the potential determinants of growth. Among those few economic theories explaining the stock market and taxation as joint determinants of the economic growth are the Levine’s (1991) endogenous growth models (EGM), which suggests that economic growth is strongly influenced by the stock market and tax policy, and the Laffer - Khaldun curve, which demonstrates that reduced tax rates on investment income would stimulate economic growth which in turn generate more tax revenue and possibly even compensate for tax incentives given on investment. We investigate ten Developing Asia nations over the period 1990 to 2008. To study differences among the countries, the study sub-divides Developing Asia into East Asia Pacific (China, Thailand, Malaysia, Indonesia, Taiwan, Philippines) and South Asia (Bangladesh, India, Pakistan, Sri Lanka). Our motivation to choose these particular countries has been influenced by the rapid expansion of the stock markets and the rise in economic growth over the entire sample period. We employ panel unit root tests, Pedroni cointegration tests and panel Granger causality tests to estimate both short and long run causal relationships between stock market, tax revenue and economic growth. Data used included logged values of GDP to proxy economic growth, total tax revenue and stock market capitalization taken as a percentage of GDP to proxy tax revenue and stock market respectively. Findings provide evidence in support of Laffer-Khaldun curve and the Levine’s (1991) EGM: stock market and tax revenue do have an impact on economic growth even though the impact might be somewhat small or in some cases even negative. This can be due to country- specific characteristics that make a successful transition from stock market and tax revenue to economic growth more difficult (i.e., corruption, difficulties in obtaining credit at the personal level, inflation). In the short run results demonstrate the existence of causal linkages (varying directions) for the countries in East Asia Pacific and South Asia. In the long run, for all the examined sub-samples the direction of relationship runs from i) economic growth and tax revenue to stock market; and ii) economic growth and stock market to tax revenue. For policy implementation, these results indicate that in order to promote economic growth, governments of ten Developing Asia should improve the channels between the stock market, taxation policy and economic growth by developing stock market liquidity and by identifying growth-oriented tax reform strategies.
Description:
Background Very limited research has been undertaken on sex workers' personal romantic relationships and the impact the nature of their work has on their relationships. This exploratory study aimed to explore the impact sex work has on women's personal romantic relationships and the use of mental separation as a coping mechanism to balance the two aspects of their lives. Fifty-five women working in the indoor sex industry in Melbourne, Australia, were recruited to complete a self-report questionnaire about various aspects of their work, including the impact of sex work on their personal relationships. Questionnaires were completed anonymously and included both closed and open-ended questions. A further six women were interviewed to 'member check' the accuracy of the questionnaire findings. Most women (78%) reported that, overall, sex work affected their personal romantic relationships in predominantly negative ways, mainly relating to issues stemming from lying, trust, guilt and jealousy. A small number of women reported positive impacts from sex work including improved sexual self-esteem and confidence. Just under half of women were in a relationship at the time of the study and, of these, 51% reported their partner was aware of the nature of their work. Seventy-seven percent of single women chose to remain single due to the nature of their work. Many women used mental separation as a coping mechanism to manage the tensions between sex work and their personal relationships. Member checking validated the accuracy of the questionnaire data. This exploratory study identified a number of ways in which sex work impacts negatively on women's personal romantic relationships. The findings of this study support the need for further studies to be undertaken to determine if the findings are reflected in a larger, more representative sample of Australian sex workers and should be considered in the context of any future intervention and support programs aimed at addressing the tensions sex workers experience between their work and personal relationships. Greater public awareness and education programs aimed at addressing the negative stigma associated with the sex industry may go some way towards easing the issues faced by women in their personal relationships.
Description:
Background Very limited research has been undertaken on sex workers' personal romantic relationships and the impact the nature of their work has on their relationships. This exploratory study aimed to explore the impact sex work has on women's personal romantic relationships and the use of mental separation as a coping mechanism to balance the two aspects of their lives. Fifty-five women working in the indoor sex industry in Melbourne, Australia, were recruited to complete a self-report questionnaire about various aspects of their work, including the impact of sex work on their personal relationships. Questionnaires were completed anonymously and included both closed and open-ended questions. A further six women were interviewed to 'member check' the accuracy of the questionnaire findings. Most women (78%) reported that, overall, sex work affected their personal romantic relationships in predominantly negative ways, mainly relating to issues stemming from lying, trust, guilt and jealousy. A small number of women reported positive impacts from sex work including improved sexual self-esteem and confidence. Just under half of women were in a relationship at the time of the study and, of these, 51% reported their partner was aware of the nature of their work. Seventy-seven percent of single women chose to remain single due to the nature of their work. Many women used mental separation as a coping mechanism to manage the tensions between sex work and their personal relationships. Member checking validated the accuracy of the questionnaire data. This exploratory study identified a number of ways in which sex work impacts negatively on women's personal romantic relationships. The findings of this study support the need for further studies to be undertaken to determine if the findings are reflected in a larger, more representative sample of Australian sex workers and should be considered in the context of any future intervention and support programs aimed at addressing the tensions sex workers experience between their work and personal relationships. Greater public awareness and education programs aimed at addressing the negative stigma associated with the sex industry may go some way towards easing the issues faced by women in their personal relationships.
Description:
The derivatization of thiamin vitamers to their respective thiochrome by ferricyanide to facilitate fluorescence detection following separation by HPLC provides a powerful analytical tool. However the polyphenolic compounds in red wine readily interact with ferricyanide, reducing the effectiveness of ferricyanide oxidation in the derivatization of thiamin. We describe a method to facilitate the removal of polyphenolic compounds that interfere with the ferricyanide derivatization of thiamin. Polyvinylpolypyrrolidone afforded the total removal of phenolic compounds from red wines and allowed a spike recovery of thiamin vitamers (101% for thiamin; 104% for TMP; and 100% for TDP) in a wide range of red wines. This research found that Merlot styles of red wine contained the highest concentration of total thiamin (29.01 ng/mL) while Pinot Noir wines contained the lowest total concentration (8.27 ng/mL).
Description:
Writing in 2016, it's sometimes hard to believe the influence that poststructuralist and postmodernist 'theory' had on university and intellectual culture in the 1980s and 1990s. Virtually every humanities and social-science department (and even some science departments) either adopted or at the very least was forced to confront the body of work of half a dozen (mainly) French thinkers and the English-speaking colleagues who took up the implications of their work. In the United States, the United Kingdom and Australia, 'theory' was deeply polarizing - either the high point of intellectual virtuosity, the voice of a new politics or a nihilistic assault on Western culture. English and Philosophy departments fractured or split entirely, newly formed cultural-studies journals enthusiastically applied theory's insights to the quotidian world, academic publication expanded massively. Outside the academy, theory was often denounced in the mainstream media as being meaningless jargon or politically dangerous, or both at the same time, while the theorists themselves retained a cult status both inside and outside the academy.