Preparation of cast aluminium alloy-mica particle composites

The optimum conditions for producing cast aluminium alloy-mica particle composites, by stirring mica particles (40 to 120 mgrm) in molten aluminium alloys (above their liquidus temperatures), followed by casting in permanent moulds, are described. Addition of magnesium either as pieces along with mica particles on the surface of the melts or as a previously added alloying element was found to be necessary to disperse appreciable quantities (1.5 to 2 wt.%) of mica particles in the melts and retain them as uniform dispersions in castings under the conditions of present investigation. These castings can be remelted and degassed with nitrogen at least once with the retention of about 80% mica particles in the castings. Electron probe micro-analysis of these cast composites showed that magnesium added to the surface of the melt along with mica has a tendency to segregate around the mica particles, apparently improving the dispersability for mica particles in liquid aluminium alloys. The mechanical properties of the aluminium alloy-mica particle composite decrease with an increase in mica content, however, even at 2.2% the composite has a tensile strength of 14.22 kg mm–2 with 1.1% elongation, a compression strength of 42.61 kg mm–2, and an impact strength of 0.30 kgm cm–2. The properties are adequate for certain bearing applications, and the aluminium-mica composite bearings were found to run under boundary lubrication, semi-dry and dry friction conditions whereas the matrix alloy (without mica) bearings seized or showed stick slip under the same conditions.

Estimating the duration and cost of weed eradication programmes

Two prerequisites for realistically embarking upon an eradication programme are that cost-benefit analysis favours this strategy over other management options and that sufficient resources are available to carry the programme through to completion. These are not independent criteria, but it is our view that too little attention has been paid to estimating the investment required to complete weed eradication programmes. We deal with this problem by using a two-pronged approach: 1) developing a stochastic dynamic model that provides an estimation of programme duration; and 2) estimating the inputs required to delimit a weed incursion and to prevent weed reproduction over a sufficiently long period to allow extirpation of all infestations. The model is built upon relationships that capture the time-related detection of new infested areas, rates of progression of infestations from the active to the monitoring stage, rates of reversion of infestations from the monitoring to active stage, and the frequency distribution of time since last detection for all infestations. This approach is applied to the branched broomrape (Orobanche ramosa) eradication programme currently underway in South Australia. This programme commenced in 1999 and currently 7450 ha are known to be infested with the weed. To date none of the infestations have been eradicated. Given recent (2008) levels of investment and current eradication methods, model predictions are that it would take, on average, an additional 73 years to eradicate this weed at an average additional cost (NPV) of $AU67.9m. When the model was run for circumstances in 2003 and 2006, the average programme duration and total cost (NPV) were predicted to be 159 and 94 years, and $AU91.3m and $AU72.3m, respectively. The reduction in estimated programme length and cost may represent progress towards the eradication objective, although eradication of this species still remains a long term prospect.

Harvest strategy evaluations and co-management for the Moreton Bay Trawl Fishery

Non-Technical Summary Seafood CRC Project 2009/774. Harvest strategy evaluations and co-management for the Moreton Bay Trawl Fishery Principal Investigator: Dr Tony Courtney, Principal Fisheries Biologist Fisheries and Aquaculture, Agri-Science Queensland Department of Agriculture, Fisheries and Forestry Level B1, Ecosciences Precinct, Joe Baker St, Dutton Park, Queensland 4102 Email: tony.courtney@daff.qld.gov.au Project objectives: 1. Review the literature and data (i.e., economic, biological and logbook) relevant to the Moreton Bay trawl fishery. 2. Identify and prioritise management objectives for the Moreton Bay trawl fishery, as identified by the trawl fishers. 3. Undertake an economic analysis of Moreton Bay trawl fishery. 4. Quantify long-term changes to fishing power for the Moreton Bay trawl fishery. 5. Assess priority harvest strategies identified in 2 (above). Present results to, and discuss results with, Moreton Bay Seafood Industry Association (MBSIA), fishers and Fisheries Queensland. Note: Additional, specific objectives for 2 (above) were developed by fishers and the MBSIA after commencement of the project. These are presented in detail in section 5 (below). The project was an initiative of the MBSIA, primarily in response to falling profitability in the Moreton Bay prawn trawl fishery. The analyses were undertaken by a consortium of DAFF, CSIRO and University of Queensland researchers. This report adopted the Australian Standard Fish Names (http://www.fishnames.com.au/). Trends in catch and effort The Moreton Bay otter trawl fishery is a multispecies fishery, with the majority of the catch composed of Greasyback Prawns (Metapenaeus bennettae), Brown Tiger Prawns (Penaeus esculentus), Eastern King Prawns (Melicertus plebejus), squid (Uroteuthis spp., Sepioteuthis spp.), Banana Prawns (Fenneropenaeus merguiensis), Endeavour Prawns (Metapenaeus ensis, Metapenaeus endeavouri) and Moreton Bay bugs (Thenus parindicus). Other commercially important byproduct includes blue swimmer crabs (Portunus armatus), three-spot crabs (Portunus sanguinolentus), cuttlefish (Sepia spp.) and mantis shrimp (Oratosquilla spp.). Logbook catch and effort data show that total annual reported catch of prawns from the Moreton Bay otter trawl fishery has declined to 315 t in 2008 from a maximum of 901 t in 1990. The number of active licensed vessels participating in the fishery has also declined from 207 in 1991 to 57 in 2010. Similarly, fishing effort has fallen from a peak of 13,312 boat-days in 1999 to 3817 boat-days in 2008 – a 71% reduction. The declines in catch and effort are largely attributed to reduced profitability in the fishery due to increased operational costs and depressed prawn prices. The low prawn prices appear to be attributed to Australian aquacultured prawns and imported aquacultured vannamei prawns, displacing the markets for trawl-caught prawns, especially small species such as Greasyback Prawns which traditionally dominated landings in Moreton Bay. In recent years, the relatively high Australian dollar has resulted in reduced exports of Australian wild-caught prawns. This has increased supply on the domestic market which has also suppressed price increases. Since 2002, Brown Tiger Prawns have dominated annual reported landings in the Moreton Bay fishery. While total catch and effort in the bay have declined to historically low levels, the annual catch and catch rates of Brown Tiger Prawns have been at record highs in recent years. This appears to be at least partially attributed to the tiger prawn stock having recovered from excessive effort in previous decades. The total annual value of the Moreton Bay trawl fishery catch, including byproduct, is about $5 million, of which Brown Tiger Prawns account for about $2 million. Eastern King Prawns make up about 10% of the catch and are mainly caught in the bay from October to December as they migrate to offshore waters outside the bay where they contribute to a large mono-specific trawl fishery. Some of the Eastern King Prawns harvested in Moreton Bay may be growth overfished (i.e., caught below the size required to maximise yield or value), although the optimum size-at-capture was not determined in this study. Banana Prawns typically make up about 5% of the catch, but can exceed 20%, particularly following heavy rainfall. Economic analysis of the fishery From the economic survey, cash profits were, on average, positive for both fleet segments in both years of the survey. However, after the opportunity cost of capital and depreciation were taken into account, the residual owner-operator income was relatively low, and substantially lower than the average share of revenue paid to employed skippers. Consequently, owner-operators were earning less than their opportunity cost of their labour, suggesting that the fleets were economically unviable in the longer term. The M2 licensed fleet were, on average, earning similar boat cash profits as the T1/M1 fleet, although after the higher capital costs were accounted for the T1/M1 boats were earning substantially lower returns to owner-operator labour. The mean technical efficiency for the fleet as a whole was estimated to be 0.67. That is, on average, the boats were only catching 67 per cent of what was possible given their level of inputs (hours fished and hull units). Almost one-quarter of observations had efficiency scores above 0.8, suggesting a substantial proportion of the fleet are relatively efficient, but some are also relatively inefficient. Both fleets had similar efficiency distributions, with median technical efficiency score of 0.71 and 0.67 for the M2 and T1/M1 boats respectively. These scores are reasonably consistent with other studies of prawn trawl fleets in Australia, although higher average efficiency scores were found in the NSW prawn trawl fleet. From the inefficiency model, several factors were found to significantly influence vessel efficiency. These included the number of years of experience as skipper, the number of generations that the skipper’s family had been fishing and the number of years schooling. Skippers with more schooling were significantly more efficient than skippers with lower levels of schooling, consistent with other studies. Skippers who had been fishing longer were, in fact, less efficient than newer skippers. However, this was mitigated in the case of skippers whose family had been involved in fishing for several generations, consistent with other studies and suggesting that skill was passed through by families over successive generations. Both the linear and log-linear regression models of total fishing effort against the marginal profit per hour performed reasonably well, explaining between 70 and 84 per cent of the variation in fishing effort. As the models had different dependent variables (one logged and the other not logged) this is not a good basis for model choice. A better comparator is the square root of the mean square error (SMSE) expressed as a percentage of the mean total effort. On this criterion, both models performed very similarly. The linear model suggests that each additional dollar of average profits per hour in the fishery increases total effort by around 26 hours each month. From the log linear model, each percentage increase in profits per hour increases total fishing effort by 0.13 per cent. Both models indicate that economic performance is a key driver of fishing effort in the fishery. The effect of removing the boat-replacement policy is to increase individual vessel profitability, catch and effort, but the overall increase in catch is less than that removed by the boats that must exit the fishery. That is, the smaller fleet (in terms of boat numbers) is more profitable but the overall catch is not expected to be greater than before. This assumes, however, that active boats are removed, and that these were also taking an average level of catch. If inactive boats are removed, then catch of the remaining group as a whole could increase by between 14 and 17 per cent depending on the degree to which costs are reduced with the new boats. This is still substantially lower than historical levels of catch by the fleet. Fishing power analyses An analysis of logbook data from 1988 to 2010, and survey information on fishing gear, was performed to estimate the long-term variation in the fleet’s ability to catch prawns (known as fishing power) and to derive abundance estimates of the three most commercially important prawn species (i.e., Brown Tiger, Eastern King and Greasyback Prawns). Generalised linear models were used to explain the variation in catch as a function of effort (i.e., hours fished per day), vessel and gear characteristics, onboard technologies, population abundance and environmental factors. This analysis estimated that fishing power associated with Brown Tiger and Eastern King Prawns increased over the past 20 years by 10–30% and declined by approximately 10% for greasybacks. The density of tiger prawns was estimated to have almost tripled from around 0.5 kg per hectare in 1988 to 1.5 kg/ha in 2010. The density of Eastern King Prawns was estimated to have fluctuated between 1 and 2 kg per hectare over this time period, without any noticeable overall trend, while Greasyback Prawn densities were estimated to have fluctuated between 2 and 6 kg per hectare, also without any distinctive trend. A model of tiger prawn catches was developed to evaluate the impact of fishing on prawn survival rates in Moreton Bay. The model was fitted to logbook data using the maximum-likelihood method to provide estimates of the natural mortality rate (0.038 and 0.062 per week) and catchability (which can be defined as the proportion of the fished population that is removed by one unit of effort, in this case, estimated to be 2.5 ± 0.4 E-04 per boat-day). This approach provided a method for industry and scientists to develop together a realistic model of the dynamics of the fishery. Several aspects need to be developed further to make this model acceptable to industry. Firstly, there is considerable evidence to suggest that temperature influences prawn catchability. This ecological effect should be incorporated before developing meaningful harvest strategies. Secondly, total effort has to be allocated between each species. Such allocation of effort could be included in the model by estimating several catchability coefficients. Nevertheless, the work presented in this report is a stepping stone towards estimating essential fishery parameters and developing representative mathematical models required to evaluate harvest strategies. Developing a method that allowed an effective discussion between industry, management and scientists took longer than anticipated. As a result, harvest strategy evaluations were preliminary and only included the most valuable species in the fishery, Brown Tiger Prawns. Additional analyses and data collection, including information on catch composition from field sampling, migration rates and recruitment, would improve the modelling. Harvest strategy evaluations As the harvest strategy evaluations are preliminary, the following results should not be adopted for management purposes until more thorough evaluations are performed. The effects, of closing the fishery for one calendar month, on the annual catch and value of Brown Tiger Prawns were investigated. Each of the 12 months (i.e., January to December) was evaluated. The results were compared against historical records to determine the magnitude of gain or loss associated with the closure. Uncertainty regarding the trawl selectivity was addressed using two selectivity curves, one with a weight at 50% selection (S50%) of 7 g, based on research data, and a second with S50% of 14 g, put forward by industry. In both cases, it was concluded that any monthly closure after February would not be beneficial to the industry. The magnitude of the benefit of closing the fishery in either January or February was sensitive to which mesh selectivity curve that was assumed, with greater benefit achieved when the smaller selectivity curve (i.e., S50% = 7 g) was assumed. Using the smaller selectivity (S50% = 7 g), the expected increase in catch value was 10–20% which equates to $200,000 to $400,000 annually, while the larger selectivity curve (S50% = 14 g) suggested catch value would be improved by 5–10%, or $100,000 to $200,000. The harvest strategy evaluations showed that greater benefits, in the order of 30–60% increases in the tiger annual catch value, could have been obtained by closing the fishery early in the year when annual effort levels were high (i.e., > 10,000 boat-days). In recent years, as effort levels have declined (i.e., ~4000 boat-days annually), expected benefits from such closures are more modest. In essence, temporal closures offer greater benefit when fishing mortality rates are high. A spatial analysis of Brown Tiger Prawn catch and effort was also undertaken to obtain a better understanding of the prawn population dynamics. This indicated that, to improve profitability of the fishery, fishers could consider closing the fishery in the period from June to October, which is already a period of low profitability. This would protect the Brown Tiger Prawn spawning stock, increase catch rates of all species in the lucrative pre-Christmas period (November–December), and provide fishers with time to do vessel maintenance, arrange markets for the next season’s harvest, and, if they wish, work at other jobs. The analysis found that the instantaneous rate of total mortality (Z) for the March–June period did not vary significantly over the last two decades. As the Brown Tiger Prawn population in Moreton Bay has clearly increased over this time period, an interesting conclusion is that the instantaneous rate of natural mortality (M) must have increased, suggesting that tiger prawn natural mortality may be density-dependent at this time of year. Mortality rates of tiger prawns for June–October were found to have decreased over the last two decades, which has probably had a positive effect on spawning stocks in the October–November spawning period. Abiotic effects on the prawns The influence of air temperature, rainfall, freshwater flow, the southern oscillation index (SOI) and lunar phase on the catch rates of the four main prawn species were investigated. The analyses were based on over 200,000 daily logbook catch records over 23 years (i.e., 1988–2010). Freshwater flow was more influential than rainfall and SOI, and of the various sources of flow, the Brisbane River has the greatest volume and influence on Moreton Bay prawn catches. A number of time-lags were also considered. Flow in the preceding month prior to catch (i.e., 30 days prior, Logflow1_30) and two months prior (31–60 days prior, Logflow31_60) had strong positive effects on Banana Prawn catch rates. Average air temperature in the preceding 4-6 months (Temp121_180) also had a large positive effect on Banana Prawn catch rates. Flow in the month immediately preceding catch (Logflow1_30) had a strong positive influence on Greasyback Prawn catch rates. Air temperature in the preceding two months prior to catch (Temp1_60) had a large positive effect on Brown Tiger Prawn catch rates. No obvious or marked effects were detected for Eastern King Prawns, although interestingly, catch rates declined with increasing air temperature 4–6 months prior to catch. As most Eastern King Prawn catches in Moreton Bay occur in October to December, the results suggest catch rates decline with increasing winter temperatures. In most cases, the prawn catch rates declined with the waxing lunar phase (high luminance/full moon), and increased with the waning moon (low luminance/new moon). The SOI explains little additional variation in prawn catch rates (~ <2%), although its influence was higher for Banana Prawns. Extrapolating findings of the analyses to long-term climate change effects should be interpreted with caution. That said, the results are consistent with likely increases in abundance in the region for the two tropical species, Banana Prawns and Brown Tiger Prawns, as coastal temperatures rise. Conversely, declines in abundance could be expected for the two temperate species, Greasyback and Eastern King Prawns. Corporate management structures An examination of alternative governance systems was requested by the industry at one of the early meetings, particularly systems that may give them greater autonomy in decision making as well as help improve the marketing of their product. Consequently, a review of alternative management systems was undertaken, with a particular focus on the potential for self-management of small fisheries (small in terms of number of participants) and corporate management. The review looks at systems that have been implemented or proposed for other small fisheries internationally, with a particular focus on self-management as well as the potential benefits and challenges for corporate management. This review also highlighted particular opportunities for the Moreton Bay prawn fishery. Corporate management differs from other co-management and even self-management arrangements in that ‘ownership’ of the fishery is devolved to a company in which fishers and government are shareholders. The company manages the fishery as well as coordinates marketing to ensure that the best prices are received and that the catch taken meets the demands of the market. Coordinated harvesting will also result in increased profits, which are returned to fishers in the form of dividends. Corporate management offers many of the potential benefits of an individual quota system without formally implementing such a system. A corporate management model offers an advantage over a self-management model in that it can coordinate both marketing and management to take advantage of this unique geographical advantage. For such a system to be successful, the fishery needs to be relatively small and self- contained. Small in this sense is in terms of number of operators. The Moreton Bay prawn fishery satisfies these key conditions for a successful self-management and potentially corporate management system. The fishery is small both in terms of number of participants and geography. Unlike other fisheries that have progressed down the self-management route, the key market for the product from the Moreton Bay fishery is right at its doorstep. Corporate management also presents a number of challenges. First, it will require changes in the way fishers operate. In particular, the decision on when to fish and what to catch will be taken away from the individual and decided by the collective. Problems will develop if individuals do not join the corporation but continue to fish and market their own product separately. While this may seem an attractive option to fishers who believe they can do better independently, this is likely to be just a short- term advantage with an overall long-run cost to themselves as well as the rest of the industry. There are also a number of other areas that need further consideration, particularly in relation to the allocation of shares, including who should be allocated shares (e.g. just boat owners or also some employed skippers). Similarly, how harvesting activity is to be allocated by the corporation to the fishers. These are largely issues that cannot be answered without substantial consultation with those likely to be affected, and these groups cannot give these issues serious consideration until the point at which they are likely to become a reality. Given the current structure and complexity of the fishery, it is unlikely that such a management structure will be feasible in the short term. However, the fishery is a prime candidate for such a model, and development of such a management structure in the future should be considered as an option for the longer term.

Econometric models of Finnish non-industrial private forest owners' timber supply and timber stock

This dissertation examines the short- and long-run impacts of timber prices and other factors affecting NIPF owners' timber harvesting and timber stocking decisions. The utility-based Faustmann model provides testable hypotheses of the exogenous variables retained in the timber supply analysis. The timber stock function, derived from a two-period biomass harvesting model, is estimated using a two-step GMM estimator based on balanced panel data from 1983 to 1991. Timber supply functions are estimated using a Tobit model adjusted for heteroscedasticity and nonnormality of errors based on panel data from 1994 to 1998. Results show that if specification analysis of the Tobit model is ignored, inconsistency and biasedness can have a marked effect on parameter estimates. The empirical results show that owner's age is the single most important factor determining timber stock; timber price is the single most important factor in harvesting decision. The results of the timber supply estimations can be interpreted using utility-based Faustmann model of a forest owner who values a growing timber in situ.

Genetic diversity of Atlantic salmon (Salmo salar) and European whitefish (Coregonus lavaretus) in the Baltic Sea

We described the patterns and extent of microsatellite DNA variation in historical and present-day Atlantic salmon (Salmo salar L.) stocks in the Baltic Sea and neighbouring areas, and in European whitefish (Coregonus lavaretus) ecotypes, populations and run-timing types in Finland. Moreover, the amount and pattern of genetic diversity in historical salmon populations before human impact were described, and the proportion of diversity maintained in the present hatchery stocks evaluated. Salmon populations in the Baltic Sea were, on average, significantly less variable than eastern Atlantic populations, and the diversity of landlocked populations (Lakes Vänern, Saimaa, Onega and Ladoga) was in turn significantly lower than that of anadromous salmon populations in the Baltic Sea populations. Within the Baltic Sea, the anadromous populations of Atlantic salmon formed three clear groups, corresponding to the northern (Gulf of Bothnia), eastern (Gulf of Finland and eastern Baltic Main Basin) and southern (western Baltic Main Basin) regions. Based on microsatellite data, three salmon population groups in the Baltic Sea were considered potentially different colonization lineages. In short- and long-term breeding programmes of Atlantic salmon, the average observed rate of loss of alleles was 4.9% and 2.0% per generation and the average rate of loss of heterozygosity was 1.4% and 1% per generation, respectively. When comparing the genetic parameters of stocks before and after hatchery breeding of several successive generations (Rivers Iijoki and Oulujoki), statistically significant changes in allele frequencies were common, while large wild stock in the Teno River has remained temporally very stable over 56 years. Despite the observed losses of genetic diversity in broodstock breeding, a large proportion of the genetic resources of the extirpated stocks are still conserved in the broodstocks. Genetic differentiation among European whitefish ecotypes was generally low, thus giving support to the hypothesis of one native European whitefish species in Fennoscandia. Among the ecotypes, the northern, large sparsely rakered, bottom-dwelling whitefish was the most unique. The known genetic differences in quantitative traits have thus either developed independently of potential phylogenetic lineages, or the lineages have mixed and the quantitative traits of the ecotypes, like gill-raker number, have later changed according to environment and selection pressures. Overall, genetic distances between the anadromous whitefish populations along the Finnish coast, especially in the Bothnian Bay area, were small. Wild whitefish populations studied had slightly higher allelic diversity than hatchery-reared populations in corresponding rivers.

Clinical tips: Actively supporting customers to make a significant lifestyle change for New Year

We have all made these New Year’s resolutions before ... to be healthier, to eat better, to look after ourselves more, to go to the gym more. Each year, we are adamant we will stick with these resolutions, but deep down, we all know most of us will have given up before February even arrives. So we have put together a few tips to help you actively support your customers to make a significant lifestyle change for the New Year. Healthy eating – it is important for your customers to have realistic expectations. It is all too easy to say they will stop eating junk food, and start ‘eating healthy’. Advising them that it is important to be realistic and starting with a few small measurable goals, such as aiming to eat two servings of fruits or five servings of vegetables each day, will work better in the long run. Small tweaks and modifications can add up to a major change quite quickly...

Undersowing in a northern climate: effects on spring cereal yield and risk of nitrate leaching

Disadvantages of invariable cereal cropping, concern of nutrient leaching and prices of nitrogen (N) fertilizer have all increased during last decades. An undersown crop, which grows together with a main crop and after harvest, could mitigate all those questions. The aim of this study was to develop undersowing in Finnish conditions, so that it suits for spring cereal farming as well as possible and enhances taking care of soil and environment, especially when control of N is concerned. In total, 17 plant species were undersown in spring cereals during the field experiments between 1991-1999 at four sites in South and Central Finland, but after selection, eight of them were studied more thoroughly. Two legumes, one grass species and one mixture of them were included in long-term trials in order to study annually repeated undersowing. Further, simultaneous broadcasting of seeds instead of separate undersowing was studied. Grain yield response and the capacity of the undersown crop to absorb soil N or fix N from atmosphere, and the release of N were of greatest interest. Seeding rates of undersown crops and N fertilization rates during annually repeated undersowing were also studied. Italian ryegrass (Lolium multiflorum Lam., IR) absorbed soil nitrate N (NO3-N) most efficiently in autumn and timothy (Phleum pratense L.) in spring. The capacity of other grass species to absorb N was low, or it was insufficient considering the negative effect on grain yield. Red clover (Trifolium pratense L.) and white clover (Trifolium repens L.) suited well in annually repeated undersowing, supplying fixed N for cereals without markedly increased risk of N leaching. Autumn oriented growth rhythm of the studied legumes was optimal for undersowing, whereas the growth rhythm of grasses was less suited but varied between species. A model of adaptive undersowing system was outlined in order to emphasize allocation of measures according needs. After defining the goal of undersowing, many decisions are to be done. When diminishing N leaching is primarily sought, a mixture of IR and timothy is advantageous. Clovers suit for replacing N fertilization, as the positive residual effect is greater than the negative effect caused by competition. A mixture of legume and non legume is a good choice when increased diversity is the main target. Seeding rate is an efficient means for adjusting competition and N effects. Broadcasting with soil covering equipment can be used to establish an undersown crop. In addition, timing and method of cover crop termination have an important role in the outcome. Continuous observing of the system is needed as for instance conditions significantly affect growth of undersown crop and on the other hand N release from crop residues may increase in long run.

Sustainable management for rangelands in a variable climate: evidence and insights from northern Australia

Inter-annual rainfall variability is a major challenge to sustainable and productive grazing management on rangelands. In Australia, rainfall variability is particularly pronounced and failure to manage appropriately leads to major economic loss and environmental degradation. Recommended strategies to manage sustainably include stocking at long-term carrying capacity (LTCC) or varying stock numbers with forage availability. These strategies are conceptually simple but difficult to implement, given the scale and spatial heterogeneity of grazing properties and the uncertainty of the climate. This paper presents learnings and insights from northern Australia gained from research and modelling on managing for rainfall variability. A method to objectively estimate LTCC in large, heterogeneous paddocks is discussed, and guidelines and tools to tactically adjust stocking rates are presented. The possible use of seasonal climate forecasts (SCF) in management is also considered. Results from a 13-year grazing trial in Queensland show that constant stocking at LTCC was far more profitable and largely maintained land condition compared with heavy stocking (HSR). Variable stocking (VAR) with or without the use of SCF was marginally more profitable, but income variability was greater and land condition poorer than constant stocking at LTCC. Two commercial scale trials in the Northern Territory with breeder cows highlighted the practical difficulties of variable stocking and provided evidence that heavier pasture utilisation rates depress reproductive performance. Simulation modelling across a range of regions in northern Australia also showed a decline in resource condition and profitability under heavy stocking rates. Modelling further suggested that the relative value of variable v. constant stocking depends on stocking rate and land condition. Importantly, variable stocking may possibly allow slightly higher stocking rates without pasture degradation. Enterprise-level simulations run for breeder herds nevertheless show that poor economic performance can occur under constant stocking and even under variable stocking in some circumstances. Modelling and research results both suggest that a form of constrained flexible stocking should be applied to manage for climate variability. Active adaptive management and research will be required as future climate changes make managing for rainfall variability increasingly challenging.

HPLC analysis of plant sterol oxidation products

Increased interest in the cholesterol-lowering effect of plant sterols has led to development of plant sterol-enriched foods. When products are enriched, the safety of the added components must be evaluated. In the case of plant sterols, oxidation is the reaction of main concern. In vitro studies have indicated that cholesterol oxides may have harmful effects. Due their structural similarity, plant sterol oxidation products may have similar health implications. This study concentrated on developing high-performance liquid chromatography (HPLC) methods that enable the investigation of formation of both primary and secondary oxidation products and thus can be used for oxidation mechanism studies of plant sterols. The applicability of the methods for following the oxidation reactions of plant sterols was evaluated by using oxidized stigmasterol and sterol mixture as model samples. An HPLC method with ultraviolet and fluorescence detection (HPLC-UV-FL) was developed. It allowed the specific detection of hydroperoxides with FL detection after post-column reagent addition. The formation of primary and secondary oxidation products and amount of unoxidized sterol could be followed by using UV detection. With the HPLC-UV-FL method, separation between oxides was essential and oxides of only one plant sterol could be quantified in one run. Quantification with UV can lead to inaccuracy of the results since the number of double bonds had effect on the UV absorbance. In the case of liquid chromatography-mass spectrometry (LC-MS), separation of oxides with different functionalities was important because some oxides of the same sterol have similar molecular weight and moreover epimers have similar fragmentation behaviour. On the other hand, coelution of different plant sterol oxides with the same functional group was acceptable since they differ in molecular weights. Results revealed that all studied plant sterols and cholesterol seem to have similar fragmentation behaviour, with only relative ion abundances being slightly different. The major advantage of MS detection coupled with LC separation is the capability to analyse totally or partly coeluting analytes if these have different molecular weights. The HPLC-UV-FL and LC-MS methods were demonstrated to be suitable for studying the photo-oxidation and thermo-oxidation reactions of plant sterols. The HPLC-UV-FL method was able to show different formation rates of hydroperoxides during photo-oxidation. The method also confirmed that plant sterols have similar photo-oxidation behaviour to cholesterol. When thermo-oxidation of plant sterols was investigated by HPLC-UV-FL and LC-MS, the results revealed that the formation and decomposition of individual hydroperoxides and secondary oxidation products could be studied. The methods used revealed that all of the plant sterols had similar thermo-oxidation behaviour when compared with each other, and the predominant reactions and oxidation rates were temperature dependent. Overall, these findings showed that with these LC methods the oxidation mechanisms of plant sterols can be examined in detail, including the formation and degradation of individual hydroperoxides and secondary oxidation products, with less sample pretreatment and without derivatization.

Petusta pitsaan : Ruokahuollon järjestelyt kriisiaikojen Suomessa

From bark bread to pizza - Food and exceptional circumstances: reactions of Finnish society to crises of food supply This study on the food supply under exceptional circumstances lies within the nutritional, historical and social sciences. The perspective and questions come under nutrition science, but are part of social decision-making. The study focuses on the first and second world wars as well as on contemporary society at the beginning of the 21st century. The main purpose of this study is to explore how Finnish society has responded to crises and what measures it has taken to sustain institutional food services and the food supply of households. The particular study interests include the school catering and food services in hospitals during the world wars. The situation in households is reflected in the counseling work carried out by state-run or civic organisations. Interest also focuses on the action of the scientific community. The decisions made in Finland are projected onto the solutions developed in some other European countries. The study is based primarily on the archive documents and annual reports prepared by food and health care authorities. Major source materials include scientific and professional publications. The evaluation of the situation in contemporary Finnish society is based on corresponding emergency plans and guidelines. The written material is supplemented by discussions with experts. Food rationing during the WWI and WWII differed in extent, details and unity. The food intake of some population groups was occasionally inadequate both in quantity, quality and safety. The counseling of the public focused on promoting self-sufficiency, improving cooking skills and widening food habits. One of the most vulnerable groups in regard to nutrition was long-term patients in institutions. As for future development, the world wars were never-theless important periods for public food services and counseling practices. WWII was also an important period for product development in the food industry. Significant work on food substitutes was carried out by Professor Carl Tigerstedt during WWI. The research of Professors A. I. Virtanen and Paavo Simola during WWII focused on vitamins. Crises threatening societies now differ from those faced a hundred years ago. Finland is bet-ter prepared, but in many ways more vulnerable to and dependent on other actors. Food rationing is a severe means of handling the scarcity of food, which is why contemporary society relies primarily on preparedness planning. Civic organisations played a key role during the world wars, and establishing an emergency food supply remains on their agenda. Although the objective of protecting the population remains the same for nutrition, food production, and food consumption, threat scenarios and the knowledge and skill levels of citizens are constantly changing. Continuous monitoring and evaluation is therefore needed.

Poverty and the Environment : Investment Poverty and the Role of Assets in Generating Welfare for Farmer Households in the Province of Herrera, Panama

Köyhiä maanviljelijöitä on usein syytetty kehitysmaiden ympäristöongelmista. On väitetty, että eloonjäämistaistelu pakottaa heidät käyttämään maata ja muita luonnonvaroja lyhytnäköisesti. Harva asiaa koskeva tutkimus on kuitenkaan tukenut tätä väitettä; perheiden köyhyyden astetta ja heidän aiheuttamaansa ympäristövaikutusta ei ole kyetty kytkemään toisiinsa. Selkeyttääkseen köyhyys-ympäristö –keskustelua, Thomas Reardon ja Steven Vosti kehittivät investointiköyhyyden käsitteen. Se tunnistaa sen kenties suuren joukon maanviljelijäperheitä, jotka eivät ole köyhiä perinteisten köyhyysmittareiden mukaan, mutta joiden hyvinvointi ei ole riittävästi köyhyysrajojen yläpuolella salliakseen perheen investoida kestävämpään maankäyttöön. Reardon ja Vosti korostivat myös omaisuuden vaikutusta perheiden hyvinvointiin, ja uskoivat sen vaikuttavan tuotanto- ja investointipäätöksiin. Tässä tutkimuksessa pyritään vastaamaan kahteen kysymykseen: Miten investointiköyhyyttä voidaan ymmärtää ja mitata? Ja, mikä on viljelijäperheiden omaisuuden hyvinvointia lisäävä vaikutus? Tätä tutkimusta varten haastateltiin 402 maanviljelijäperhettä Väli-Amerikassa, Panaman tasavallan Herreran läänissä. Näiden perheiden hyvinvointia mitattiin heidän kulutuksensa mukaan, ja paikalliset köyhyysrajat laskettiin paikallisen ruoan hinnan mukaan. Herrerassa ihminen tarvitsee keskimäärin 494 dollaria vuodessa saadakseen riittävän ravinnon, tai 876 dollaria vuodessa voidakseen ravinnon lisäksi kattaa muitakin välttämättömiä menoja. Ruoka- eli äärimmäisen köyhyyden rajan alle jäi 15,4% tutkituista perheistä, ja 33,6% oli jokseenkin köyhiä, eli saavutti kyllä riittävän ravitsemuksen, muttei kyennyt kustantamaan muita perustarpeitaan. Molempien köyhyysrajojen yläpuolelle ylsi siis 51% tutkituista perheistä. Näiden köyhyysryhmien välillä on merkittäviä eroavaisuuksia ei vain perheiden varallisuuden, tulojen ja investointistrategioiden välillä, mutta myös perheiden rakenteessa, elinympäristössä ja mahdollisuuksissa saada palveluja. Investointiköyhyyden mittaaminen osoittautui haastavaksi. Herrerassa viljelijät eivät tee investointeja puhtaasti ympäristönsuojeluun, eikä maankäytön kestävyyttä muutenkaan pystytty yhdistämään perheiden hyvinvoinnin tasoon. Siksi investointiköyhyyttä etsittiin sellaisena hyvinvoinnin tasona, jonka alapuolella elävien perheiden parissa tuottavat maanparannusinvestoinnit eivät enää ole suorassa suhteessa hyvinvointiin. Tällaisia investointeja ovat mm. istutetut aidat, lannoitus ja paranneltujen laiduntyyppien viljely. Havaittiin, että jos perheen hyvinvointi putoaa alle 1000 dollarin/henkilö/vuosi, tällaiset tuottavat maanparannusinvestoinnit muuttuvat erittäin harvinaisiksi. Investointiköyhyyden raja on siis noin kaksi kertaa riittävän ravitsemuksen hinta, ja sen ylitti 42,3% tutkituista perheistä. Heille on tyypillistä, että molemmat puolisot käyvät työssä, ovat korkeasti koulutettuja ja yhteisössään aktiivisia, maatila tuottaa paremmin, tilalla kasvatetaan vaativampia kasveja, ja että he ovat kerryttäneet enemmän omaisuutta kuin investointi-köyhyyden rajan alla elävät perheet. Tässä tutkimuksessa kyseenalaistettiin yleinen oletus, että omaisuudesta olisi poikkeuksetta hyötyä viljelijäperheelle. Niinpä omaisuuden vaikutusta perheiden hyvinvointiin tutkittiin selvittämällä, mitä reittejä pitkin perheiden omistama maa, karja, koulutus ja työikäiset perheenjäsenet voisivat lisätä perheen hyvinvointia. Näiden hyvinvointi-mekanismien ajateltiin myös riippuvan monista väliin tulevista tekijöistä. Esimerkiksi koulutus voisi lisätä hyvinvointia, jos sen avulla saataisiin paremmin palkattuja töitä tai perustettaisiin yritys; mutta näihin mekanismeihin saattaa vaikuttaa vaikkapa etäisyys kaupungeista tai se, omistaako perhe ajoneuvon. Köyhimpien perheiden parissa nimenomaan koulutus olikin ainoa tutkittu omaisuuden muoto, joka edisti perheen hyvinvointia, kun taas maasta, karjasta tai työvoimasta ei ollut apua köyhyydestä nousemiseen. Varakkaampien perheiden parissa sen sijaan korkeampaa hyvinvointia tuottivat koulutuksen lisäksi myös maa ja työvoima, joskin monesta väliin tulevasta muuttujasta, kuten tuotantopanoksista riippuen. Ei siis ole automaatiota, jolla omaisuus parantaisi perheiden hyvinvointia. Vaikka rikkailla onkin yleensä enemmän karjaa kuin köyhemmillä, ei tässä aineistossa löydetty yhtään mekanismia, jota kautta karjan määrä tuottaisi korkeampaa hyvinvointia viljelijäperheille. Omaisuuden keräämisen ja hyödyntämisen strategiat myös muuttuvat hyvinvoinnin kasvaessa ja niihin vaikuttavat monet ulkoiset tekijät. Ympäristön ja köyhyyden suhde on siis edelleen epäselvä. Köyhyyden voittaminen vaatii pitkällä tähtäimellä sitä, että viljelijäperheet nousisivat investointiköyhyyden rajan yläpuolelle. Näin heillä olisi varaa alkaa kartuttaa omaisuutta ja investoida kestävämpään maankäyttöön. Tällä hetkellä kuitenkin isolle osalle herreralaisia perheitä tuo raja on kaukana tavoittamattomissa. Miten päästä yli tuhannen dollarin kulutukseen perheenjäsentä kohden, mikäli elintaso ei yllä edes riittävään ravitsemukseen? Ja sittenkin, vaikka hyvinvointi kohenisi, ei ympäristön kannalta parannuksia ole välttämättä odotettavissa, mikäli karjalaumat kasvavat ja eroosioalttiit laitumet leviävät.

Validity of the OMNI rating of perceived exertion scale for children and adolescents with cerebral palsy

Aim This study evaluated the validity of the OMNI Walk/Run Rating of Perceived Exertion (OMNI-RPE) scores with heart rate and oxygen consumption (VO2) for children and adolescents with cerebral palsy (CP). Method Children and adolescents with CP, aged 6 to 18 years and Gross Motor Function Classification System (GMFCS) levels I to III completed a physical activity protocol with seven trials ranging in intensity from sedentary to moderate-to-vigorous. VO2 and heart rate were recorded during the physical activity trials using a portable indirect calorimeter and heart rate monitor. Participants reported OMNI-RPE scores for each trial. Concurrent validity was assessed by calculating the average within-subject correlation between OMNI-RPE ratings and the two physiological indices. Results For the correlational analyses, 48 participants (22 males, 26 females; age 12y 6mo, SD 3y 4mo) had valid bivariate data for VO2 and OMNI-RPE, while 40 participants (21 males, 19 females; age 12y 5mo, SD 2y 9mo) had valid bivariate data for heart rate and OMNI-RPE. VO2 (r=0.80; 95% CI 0.66–0.88) and heart rate (r=0.83; 95% CI 0.70–0.91) were moderately to highly correlated to OMNI-RPE scores. No difference was found for the correlation of physiological data and OMNI-RPE scores across the three GMFCS levels. The OMNI-RPE scores increased significantly in a dose-response manner (F6,258=116.1, p<0.001) as exercise intensity increased from sedentary to moderate-to-vigorous. Interpretation OMNI-RPE is a clinically feasible option to monitor exercise intensity in ambulatory children and adolescents with CP.

Hanging drop: An in vitro air toxic exposure model using human lung cells in 2D and 3D structures

Using benzene as a candidate air toxicant and A549 cells as an in vitro cell model, we have developed and validated a hanging drop (HD) air exposure system that mimics an air liquid interface exposure to the lung for periods of 1 h to over 20 days. Dose response curves were highly reproducible for 2D cultures but more variable for 3D cultures. By comparing the HD exposure method with other classically used air exposure systems, we found that the HD exposure method is more sensitive, more reliable and cheaper to run than medium diffusion methods and the CULTEX (R) system. The concentration causing 50% of reduction of cell viability (EC50) for benzene, toluene, p-xylene, m-xylene and o-xylene to A549 cells for 1 h exposure in the HD system were similar to previous in vitro static air exposure. Not only cell viability could be assessed but also sub lethal biological endpoints such as DNA damage and interleukin expressions. An advantage of the HD exposure system is that bioavailability and cell concentrations can be derived from published physicochemical properties using a four compartment mass balance model. The modelled cellular effect concentrations EC50(cell) for 1 h exposure were very similar for benzene, toluene and three xylenes and ranged from 5 to 15 mmol/kg(dry weight) which corresponds to the intracellular concentration of narcotic chemicals in many aquatic species, confirming the high sensitivity of this exposure method. (C) 2013 Elsevier B.V. All rights reserved.

Informational efficiency of the European Union emission allowance market

This thesis studies the informational efficiency of the European Union emission allowance (EUA) market. In an efficient market, the market price is unpredictable and profits above average are impossible in the long run. The main research problem is does the EUA price follow a random walk. The method is an econometric analysis of the price series, which includes an autocorrelation coefficient test and a variance ratio test. The results reveal that the price series is autocorrelated and therefore a nonrandom walk. In order to find out the extent of predictability, the price series is modelled with an autoregressive model. The conclusion is that the EUA price is autocorrelated only to a small degree and that the predictability cannot be used to make extra profits. The EUA market is therefore considered informationally efficient, although the price series does not fulfill the requirements of a random walk. A market review supports the conclusion, but it is clear that the maturing of the market is still in process.

Stretching single DNA-molecules with temperature-stabilized optical tweezers

This thesis consists of two parts; in the first part we performed a single-molecule force extension measurement with 10kb long DNA-molecules from phage-λ to validate the calibration and single-molecule capability of our optical tweezers instrument. Fitting the worm-like chain interpolation formula to the data revealed that ca. 71% of the DNA tethers featured a contour length within ±15% of the expected value (3.38 µm). Only 25% of the found DNA had a persistence length between 30 and 60 nm. The correct value should be within 40 to 60 nm. In the second part we designed and built a precise temperature controller to remove thermal fluctuations that cause drifting of the optical trap. The controller uses feed-forward and PID (proportional-integral-derivative) feedback to achieve 1.58 mK precision and 0.3 K absolute accuracy. During a 5 min test run it reduced drifting of the trap from 1.4 nm/min in open-loop to 0.6 nm/min in closed-loop.