Relationship between physical capacity and match performance in semiprofessional Australian rules football

This study investigated the relationship between physical performance and match performance in Australian Rules Football (ARF). Thirty-six semiprofessional ARF players participated in this study. Physical capacity was measured using a 3-km time trial. Match performance was measured throughout the 2013 season through 2 methods: direct game involvements (DGIs) per minute and a recording of coaches\u27 vote after the game. The main finding of the study was that 3-km time trial performance was a significant predictor of DGI per minute (p ≤ 0.05). In addition, the number of senior games played was also significant in predicting DGI per minute (p ≤ 0.05). Furthermore, the number of senior games significantly correlated with coaches\u27 votes (p ≤ 0.05). There were no significant relationships between 3-km time trial and coaches\u27 vote. The results highlight the importance of developing physical capacity in the preseason period; the players who were better performers in the 3-km time trial had a greater number of DGIs per minute. This information is important to consider in preseason planning to ensure sufficient time is dedicated to developing physical capacity in the training program, as it is directly associated with performance. In addition, this research also highlights the importance of playing experience in relation to team selection. Playing experience, as measured by the number of senior games played, had a significant relationship with both measures of match performance

The Impacts of Food Safety Information on Meat Demand: A Cross-Commodity Approach Using U.S. Household Data

The potential impacts of a food safety event on consumer demand for meat is of significant concern to producers, packers, processors, retail businesses, and the USDA. This study investigates whether publicized food safety information from the printed media on beef, pork, and poultry, impacts the demand for these commodities. A four commodity complete demand system is employed using monthly household level data on meat purchases collected by the Nielsen Company, with separate food safety indices incorporated for beef, pork, and poultry. Results from the analysis indicate that consumers purchase relatively high levels of pre-committed quantities of pork, chicken, and turkey, while beef consumption appears to be primarily from supernumerary expenditures. The results also indicate that seasonal demand patterns are statistically significant in explaining the quantity of meat and poultry demanded. However, the food safety variables are not jointly statistically significant from zero.Demand and Price Analysis, Food Consumption/Nutrition/Food Safety,

Testing for Market Power in Multiple-Input, Multiple-Output Industries: The Australian Grains and Oilseeds Industries

Recent empirical studies have found significant evidence of departures from competition in the input side of the Australian bread, breakfast cereal and margarine end-product markets. For example, Griffith (2000) found that firms in some parts of the processing and marketing sector exerted market power when purchasing grains and oilseeds from farmers. As noted at the time, this result accorded well with the views of previous regulatory authorities (p.358). In the mid-1990s, the Prices Surveillence Authority (PSA 1994)determined that the markets for products contained in the Breakfast Cereals and Cooking Oils and Fats indexes were "not effectively competitive"(p.14). The PSA consequently maintained price surveillence on the major firms in this product group. The Griffith result is also consistent with the large number of legal judgements against firms in this sector over the past decade for price fixing or other types of non-competitive behaviour. For example, bread manufacturer George Weston was fined twice during 2000 for non-competitive conduct and the ACCC has also recently pursued and won cases against retailer Safeway in grains and oilseeds product lines. Griffith obtained his results using highly aggregated data and a relatively simple empirical model. In this study we focus on confirming the earlier results by formally testing for competitive behaviour in the Australian grains and oilseeds industries using a more sophisticated empirical model and a less aggregated grains and oilseeds data set. We specify a general duality model of profit maximisation that allows for imperfect competition in both the input and output markets of the grains and oilseeds industries. The model also allows for variable-proportions technologies and can be regarded as a generalisation of several models appearing in the agricultural economics and industrial organisation literatures. Aggregate Australian data taken from the 1996-97 input-output tables are used to define the structure of the relevant industries, and time series data are used implement the model for thirteen grains and oilseeds products handled by seven groups of agents. The model is estimated in a Bayesian econometrics framework. Results are reported in terms of the characteristics of estimated probability distributions for demand and supply elasticities and indexes of market power. Our results suggest that there is a positive probability that: (a) flour and cereal food product manufacturers exert market power when purchasing wheat, barley, oats and triticale; (b) beer and malt manufacturers exert market power when purchasing wheat and barley; and (c) other food product manufacturers exert market power when purchasing wheat, barley, oats and triticale. What is interesting is that each of the transaction nodes where market power is indicated is one where a farm commodity is sold to a processing sector that is, the evidence suggests oligopsonistic behaviour by grains buyers. The wheat and barley industries seem to be especially disadvantaged by this type of market conduct. A related and equally interesting result is that there was no consistent evidence of market power in the downstream nodes of the data set relating to the sales of flour and other cereal foods, or the sale of bread and other bakery products. These transaction points are where legal judgements against suppliers have been made in the recent past. We have stated our results in quite cautious language, as there is much uncertainty surrounding our estimates. This stems partly from the lack of good quality data, so we suggest that one avenue for future research should be improving the collection and integrity of relevant data (especially including the retail and distributive nodes of the various markets).Industrial Organization, Marketing,

Distribution of Gains from Cattle Development in a Multi-Stage Production System: The Case of the Bali Beef Industry

Beef production in Bali is dominated by smallholders, just like the majority of Indonesian agriculture. A wide range of policies has been implemented to enhance development of the Bali beef industry. Knowledge about the distribution of the returns from the development of the cattle industry, including marketing, informs decision making. This paper examines the benefits from cattle development in a multi-stage production representation of the Bali beef industry using equilibrium displacement modelling (EDM). Benefits are measured as changes in economic surplus. The distribution of benefits among farmers, processors and retailers is also examined.beef production, government policy, EDM, economic surplus., Agricultural and Food Policy,

Book reviews

Teaching/Communication/Extension/Profession,

Food Price Policy in Indonesia

Agricultural and Food Policy,

The effect of meltwater plumes on the melting of a vertical glacier face

Freshwater produced by the surface melting of ice sheets is commonly discharged into ocean fjords from the bottom of deep fjord-terminating glaciers. The discharge of the freshwater forms upwelling plumes in front of the glacier calving face. We simulate the meltwater plumes emanated into an unstratified environment using a non-hydrostatic ocean model with an unstructured mesh and subgrid-scale mixing calibrated by comparison to established plume theory. The presence of an ice face reduces the entrainment of seawater into the meltwater plumes, so the plumes remain attached to the ice front, in contrast to previous simple models. Ice melting increases with height above the discharge, also in contrast to some simple models, and we speculate that this ‘overcutting’ may contribute to a tendency of icebergs to topple inwards toward the ice face upon calving. The overall melt rate is found to increase with discharge flux only up to a critical value, which depends on the channel size. The melt rate is not a simple function of the subglacial discharge flux, as assumed by many previous studies. For a given discharge flux, the geometry of the plume source also significantly affects the melting, with higher melt rates obtained for a thinner, wider source. In a wider channel, two plumes are emanated near the source and these plumes eventually coalesce. Such merged meltwater plumes ascend faster and increase the maximum melt rate near the center of the channel. The melt rate per unit discharge decreases as the subglacial system becomes more channelised

On the conditional frazil ice instability in seawater

It has been suggested that the presence of frazil ice can lead to a conditional instability in seawater. Any frazil forming in the water column reduces the bulk density of a parcel of frazil-seawater mixture, causing it to rise. Due to the pressure-decrease in the freezing point, this causes more frazil to form, causing the parcel to accelerate, and so on. We use linear stability analysis and a non-hydrostatic ocean model to study this instability. We find that frazil ice growth caused by the rising of supercooled water is indeed able to generate a buoyancy-driven instability. Even in a gravitationally stable water column, the frazil ice mechanism can still generate convection. The instability does not operate in the presence of strong density stratification, high thermal driving (warm water), a small initial perturbation, high background mixing or the prevalence of large frazil ice crystals. In an unstable water column the instability is not necessarily expressed in frazil ice at all times; an initial frazil perturbation may melt and refreeze. Given a large enough initial perturbation this instability can allow significant ice growth. A model shows frazil ice growth in an Ice Shelf Water plume several kilometres from an ice shelf, under similar conditions to observations of frazil ice growth under sea ice. The presence of this instability could be a factor affecting the growth of sea ice near ice shelves, with implications for Antarctic bottom water formation