Playing alone, playing with others: Differences in player experience and indicators of wellbeing

Video game play is becoming an increasingly social experience, yet we have little understanding of how social and solitary modes of play differ in terms of the player experience or interact with player wellbeing. An online survey (n = 446) collected data on players' current mode of play, their game play experience, social capital gained from game play and wellbeing. The results indicate that social and solitary players differ in terms of degree of autonomy, presence and relatedness experienced, while the different types of social play are associated with differences in relatedness and social capital experienced. Different predictors of wellbeing were also present across solitary and social player samples. People who play games on their own experience greater wellbeing when experiencing in-game autonomy. Social players experience greater wellbeing when playing with strangers, and when experiencing in-game bridging social capital. All players experienced increased wellbeing with age and decreased wellbeing with greater amounts of play.

Characterization of the mitochondrial active-site serine protein LACTB: filaments in the mitochondrial intermembrane space

Mitochondria have evolved from endosymbiotic alpha-proteobacteria. During the endosymbiotic process early eukaryotes dumped the major component of the bacterial cell wall, the peptidoglycan layer. Peptidoglycan is synthesized and maintained by active-site serine enzymes belonging to the penicillin-binding protein and the β-lactamase superfamily. Mammals harbor a protein named LACTB that shares sequence similarity with bacterial penicillin-binding proteins and β-lactamases. Since eukaryotes lack the synthesis machinery for peptidoglycan, the physiological role of LACTB is intriguing. Recently, LACTB has been validated in vivo to be causative for obesity, suggesting that LACTB is implicated in metabolic processes. The aim of this study was to investigate the phylogeny, structure, biochemistry and cell biology of LACTB in order to elucidate its physiological function. Phylogenetic analysis revealed that LACTB has evolved from penicillin binding-proteins present in the bacterial periplasmic space. A structural model of LACTB indicates that LACTB shares characteristic features common to all penicillin-binding proteins and β-lactamases. Recombinat LACTB protein expressed in E. coli was recovered in significant quantities. Biochemical and cell biology studies showed that LACTB is a soluble protein localized in the mitochondrial intermembrane space. Further analysis showed that LACTB preprotein underwent proteolytic processing disclosing an N-terminal tetrapeptide motif also found in a set of cell death-inducing proteins. Electron microscopy structural studies revealed that LACTB can polymerize to form stable filaments with lengths ranging from twenty to several hundred nanometers. These data suggest that LACTB filaments define a distinct microdomain in the intermembrane space. A possible role of LACTB filaments is proposed in the intramitochondrial membrane organization and microcompartmentation. The implications of these findings offer novel insight into the evolution of mitochondria. Further studies of the LACTB function might provide a tool to treat mitochondria-related metabolic diseases.

Mitochondrial Malfunction in Tumor Formation and Neuromuscular Diseases : Consequences of defects in fumarate hydratase and in the respiratory chain

The mitochondrion is an organelle of outmost importance, and the mitochondrial network performs an array of functions that go well beyond ATP synthesis. Defects in mitochondrial performance lead to diseases, often affecting nervous system and muscle. Although many of these mitochondrial diseases have been linked to defects in specific genes, the molecular mechanisms underlying the pathologies remain unclear. The work in this thesis aims to determine how defects in mitochondria are communicated within - and interpreted by - the cells, and how this contributes to disease phenotypes. Fumarate hydratase (FH) is an enzyme of the citrate cycle. Recessive defects in FH lead to infantile mitochondrial encephalopathies, while dominant mutations predispose to tumor formation. Defects in succinate dehydrogenase (SDH), the enzyme that precedes FH in the citrate cycle, have also been described. Mutations in SDH subunits SDHB, SDHC and SDHD are associated with tumor predisposition, while mutations in SDHA lead to a characteristic mitochondrial encephalopathy of childhood. Thus, the citrate cycle, via FH and SDH, seems to have essential roles in mitochondrial function, as well as in the regulation of processes such as cell proliferation, differentiation or death. Tumor predisposition is not a typical feature of mitochondrial energy deficiency diseases. However, defects in citrate cycle enzymes also affect mitochondrial energy metabolism. It is therefore necessary to distinguish what is specific for defects in citrate cycle, and thus possibly associated with the tumor phenotype, from the generic consequences of defects in mitochondrial aerobic metabolism. We used primary fibroblasts from patients with recessive FH defects to study the cellular consequences of FH-deficiency (FH-). Similarly to the tumors observed in FH- patients, these fibroblasts have very low FH activity. The use of primary cells has the advantage that they are diploid, in contrast with the aneuploid tumor cells, thereby enabling the study of the early consequences of FH- in diploid background, before tumorigenesis and aneuploidy. To distinguish the specific consequences of FH- from typical consequences of defects in mitochondrial aerobic metabolism, we used primary fibroblasts from patients with MELAS (mitochondrial encephalopathy with lactic acidosis and stroke-like episodes) and from patients with NARP (neuropathy, ataxia and retinitis pigmentosa). These diseases also affect mitochondrial aerobic metabolism but are not known to predispose to tumor formation. To study in vivo the systemic consequences of defects in mitochondrial aerobic metabolism, we used a transgenic mouse model of late-onset mitochondrial myopathy. The mouse contains a transgene with an in-frame duplication of a segment of Twinkle, the mitochondrial replicative helicase, whose defects underlie the human disease progressive external ophthalmoplegia. This mouse model replicates the phenotype in the patients, particularly neuronal degeneration, mitochondrial myopathy, and subtle decrease of respiratory chain activity associated with mtDNA deletions. Due to the accumulation of mtDNA deletions, the mouse was named deletor. We first studied the consequences of FH- and of respiratory chain defects for energy metabolism in primary fibroblasts. To further characterize the effects of FH- and respiratory chain malfunction in primary fibroblasts at transcriptional level, we used expression microarrays. In order to understand the in vivo consequences of respiratory chain defects in vivo, we also studied the transcriptional consequences of Twinkle defects in deletor mice skeletal muscle, cerebellum and hippocampus. Fumarate accumulated in the FH- homozygous cells, but not in the compound heterozygous lines. However, virtually all FH- lines lacked cytoplasmic FH. Induction of glycolysis was common to FH-, MELAS and NARP fibroblasts. In deletor muscle glycolysis seemed to be upregulated. This was in contrast with deletor cerebellum and hippocampus, where mitochondrial biogenesis was in progress. Despite sharing a glycolytic pattern in energy metabolism, FH- and respiratory chain defects led to opposite consequences in redox environment. FH- was associated with reduced redox environment, while MELAS and NARP displayed evidences of oxidative stress. The deletor cerebellum had transcriptional induction of antioxidant defenses, suggesting increased production of reactive oxygen species. Since the fibroblasts do not represent the tissues where the tumors appear in FH- patients, we compared the fibroblast array data with the data from FH- leiomyomas and normal myometrium. This allowed the determination of the pathways and networks affected by FH-deficiency in primary cells that are also relevant for myoma formation. A key pathway regulating smooth muscle differentiation, SRF (serum response factor)-FOS-JUNB, was found to be downregulated in FH- cells and in myomas. While in the deletor mouse many pathways were affected in a tissue-specific basis, like FGF21 induction in the deletor muscle, others were systemic, such as the downregulation of ALAS2-linked heme synthesis in all deletor tissues analyzed. However, interestingly, even a tissue-specific response of FGF21 excretion could elicit a global starvation response. The work presented in this thesis has contributed to a better understanding of mitochondrial stress signalling and of pathways interpreting and transducing it to human pathology.

Indicators of wellbeing in recreational video game players

Video game play is a popular entertainment choice, yet we have a limited understanding of the potential wellbeing benefits associated with recreational play. An online survey (final sample, n = 297) addresses this by investigating how the player experience related to wellbeing. The impact of amount of play, game genre, mode of play (social or solitary play) and the psychological experience of play (flow and need satisfaction) on a multi-dimensional measure of wellbeing (emotional, psychological and social) was examined via hierarchical regression. Age, gender, the play of casual games compared to shooters, and in-game experiences of flow, autonomy and relatedness were associated with increases in dimensions of wellbeing.

Testing the effectiveness of the SKIM foam fractionator to reduce nutrient levels in prawn farm effluent

To experimentally investigate the effect of the “SKIM” mechanical foam fractionator on suspended material and the nutrient levels in prawn farm effluent, a series of standardised short-term treatments were applied to various effluent types in a static 10,000-litre water body. Prawn pond effluents were characterised by watercolour and dominance of phytoplankton species. Three effluent types were tested, namely 1) particulate-rich effluent with little apparent phytoplankton, 2) green mircoalgal bloom predominately made up of single celled phytoplankton, and 3) brown microalgal bloom with higher prevalence of diatoms. The effluent types were similar (P>0.05) in non-volatile particulate material, and nitrate/nitrite but varied from each other in the following ways: 1) The particulate-rich effluents were lower (P<0.05) in volatile solids (compared to brown blooms), total Kjeldahl nitrogen, dissolved organic nitrogen, dissolved organic phosphorus and chlorophyll a (compared to both green and brown blooms). 2) The brown blooms were higher (P<0.05) in ammonia (compared to green blooms), total nitrogen and total phosphorus (compared to both green and particulate-rich effluent), but were lower (P<0.05) in inorganic phosphorus (compared to both green and particulate-rich effluent). 3) The green blooms were higher (P<0.05) in dissolved (both organic and inorganic) phosphorus (compared to both brown and particulate-rich effluents). Although the effluent types varied significantly in these aspects the effect of the Skim treatment was similar for all parameters measured except total phosphorus. Bloom type and Skim-treatment period significantly (P<0.05) affected total Kjeldahl phosphorus concentrations. For all effluent types there was a continuous significant reduction (P<0.05) in total Kjeldahl phosphorus during the initial 6-hour treatment period. Levels of total suspended solids and volatile suspended solids in all effluent types were significantly (P<0.05) reduced in the first 2 hours but not thereafter. Non-volatile suspended solids were also significantly (P<0.05) reduced in the first 2 hours (30 to 40 % reduction) and a further 40% reduction occurred in the particulate-rich effluent over the next 2 hours. Mean values for total ammonia, dissolved organic nitrogen, total Kjeldahl nitrogen, total nitrogen, chlorophyll a and dissolved organic or inorganic phosphorus levels were not significantly (P>0.05) affected by the Skim unit in any bloom type during the initial 6 hours of testing. Nevertheless, non-significant nitrogen reductions did occur. Foam production by the Skim unit varied with different blooms, resulting in different concentrate volumes and different end points for separate experiments. Concentrate volumes were generally high for the particulate-rich and green blooms (175 – 370 litres) and low for the brown blooms (25 – 80 litres). This was due to the low tendency of the brown bloom to produce foam. This generated higher nutrient concentrations in the associated condensed foam, but may have limited the treatment efficiency. The results suggest that in this application, the Skim unit did not remove micro-algae as effectively as was anticipated. However, it was effective at removing other suspended solids. Considering these attributes and the other uses of this machinery documented by the manufactures, the unit’s oxygenation mixing capacities coupled with inorganic solids removal may provide a suitable mechanism for construction of a continuously mixed bioreactor that utilises the filtration and profit making abilities of bivalves.

Molecular Mechanisms of Androgen Receptor Interactions

The androgen receptor (AR) mediates the effects of the male sex-steroid hormones (androgens), testosterone and 5?-dihydrotestosterone. Androgens are critical in the development and maintenance of male sexual characteristics. AR is a member of the steroid receptor ligand-inducible transcription factor family. The steroid receptor family is a subgroup of the nuclear receptor superfamily that also includes receptors for the active forms of vitamin A, vitamin D3, and thyroid hormones. Like all nuclear receptors, AR has a conserved modular structure consisting of a non-conserved amino-terminal domain (NTD), containing the intrinsic activation function 1, a highly conserved DNA-binding domain, and a conserved ligand-binding domain (LBD) that harbors the activation function 2. Each of these domains plays an important role in receptor function and signaling, either via intra- and inter-receptor interactions, interactions with specific DNA sequences, termed hormone response elements, or via functional interactions with domain-specific proteins, termed coregulators (coactivators and corepressors). Upon binding androgens, AR acquires a new conformational state, translocates to the nucleus, binds to androgen response elements, homodimerizes and recruits sequence-specific coregulatory factors and the basal transcription machinery. This set of events is required to activate gene transcription (expression). Gene transcription is a strictly modulated process that governs cell growth, cell homeostasis, cell function and cell death. Disruptions of AR transcriptional activity caused by receptor mutations and/or altered coregulator interactions are linked to a wide spectrum of androgen insensitivity syndromes, and to the pathogenesis of prostate cancer (CaP). The treatment of CaP usually involves androgen depletion therapy (ADT). ADT achieves significant clinical responses during the early stages of the disease. However, under the selective pressure of androgen withdrawal, androgen-dependent CaP can progress to an androgen-independent CaP. Androgen-independent CaP is invariably a more aggressive and untreatable form of the disease. Advancing our understanding of the molecular mechanisms behind the switch in androgen-dependency would improve our success of treating CaP and other AR related illnesses. This study evaluates how clinically identified AR mutations affect the receptor s transcriptional activity. We reveal that a potential molecular abnormality in androgen insensitivity syndrome and CaP patients is caused by disruptions of the important intra-receptor NTD/LBD interaction. We demonstrate that the same AR LBD mutations can also disrupt the recruitment of the p160 coactivator protein GRIP1. Our investigations reveal that 30% of patients with advanced, untreated local CaP have somatic mutations that may lead to increases in AR activity. We report that somatic mutations that activate AR may lead to early relapse in ADT. Our results demonstrate that the types of ADT a CaP patient receives may cause a clustering of mutations to a particular region of the receptor. Furthermore, the mutations that arise before and during ADT do not always result in a receptor that is more active, indicating that coregulator interactions play a pivotal role in the progression of androgen-independent CaP. To improve CaP therapy, it is necessary to identify critical coregulators of AR. We screened a HeLa cell cDNA library and identified small carboxyl-terminal domain phosphatase 2 (SCP2). SCP2 is a protein phosphatase that directly interacts with the AR NTD and represses AR activity. We demonstrated that reducing the endogenous cellular levels of SCP2 causes more AR to load on to the prostate specific antigen (PSA) gene promoter and enhancer regions. Additionally, under the same conditions, more RNA polymerase II was recruited to the PSA promoter region and overall there was an increase in androgen-dependent transcription of the PSA gene, revealing that SCP2 could play a role in the pathogenesis of CaP.

Synergistic Execution of Stream Programs on Multicores with Accelerators

The StreamIt programming model has been proposed to exploit parallelism in streaming applications oil general purpose multicore architectures. The StreamIt graphs describe task, data and pipeline parallelism which can be exploited on accelerators such as Graphics Processing Units (GPUs) or CellBE which support abundant parallelism in hardware. In this paper, we describe a novel method to orchestrate the execution of if StreamIt program oil a multicore platform equipped with an accelerator. The proposed approach identifies, using profiling, the relative benefits of executing a task oil the superscalar CPU cores and the accelerator. We formulate the problem of partitioning the work between the CPU cores and the GPU, taking into account the latencies for data transfers and the required buffer layout transformations associated with the partitioning, as all integrated Integer Linear Program (ILP) which can then be solved by an ILP solver. We also propose an efficient heuristic algorithm for the work-partitioning between the CPU and the GPU, which provides solutions which are within 9.05% of the optimal solution on an average across the benchmark Suite. The partitioned tasks are then software pipelined to execute oil the multiple CPU cores and the Streaming Multiprocessors (SMs) of the GPU. The software pipelining algorithm orchestrates the execution between CPU cores and the GPU by emitting the code for the CPU and the GPU, and the code for the required data transfers. Our experiments on a platform with 8 CPU cores and a GeForce 8800 GTS 512 GPU show a geometric mean speedup of 6.94X with it maximum of 51.96X over it single threaded CPU execution across the StreamIt benchmarks. This is a 18.9% improvement over it partitioning strategy that maps only the filters that cannot be executed oil the GPU - the filters with state that is persistent across firings - onto the CPU.

Area Efficient Loop Filter Design for Charge Pump Phase Locked Loop

In this paper, two new dual-path based area efficient loop filtercircuits are proposed for Charge Pump Phase Locked Loop (CPPLL). The proposed circuits were designed in 0.25 CSM analog process with 1.8V supply. The proposed circuits achievedup to 85% savings in capacitor area. Simulations showed goodmatch of the new circuits with the conventional circuit. Theproposed circuits are particularly useful in applications thatdemand low die area.

An Online Implementable Differential Evolution Tuned Optimal Guidance Law

This paper proposes a novel application of differential evolution to solve a difficult dynamic optimisation or optimal control problem. The miss distance in a missile-target engagement is minimised using differential evolution. The difficulty of solving it by existing conventional techniques in optimal control theory is caused by the nonlinearity of the dynamic constraint equation, inequality constraint on the control input and inequality constraint on another parameter that enters problem indirectly. The optimal control problem of finding the minimum miss distance has an analytical solution subject to several simplifying assumptions. In the approach proposed in this paper, the initial population is generated around the seed value given by this analytical solution. Thereafter, the algorithm progresses to an acceptable final solution within a few generations, satisfying the constraints at every iteration. Since this solution or the control input has to be obtained in real time to be of any use in practice, the feasibility of online implementation is also illustrated.

GRDC Improving crop and farm water use efficiency in Australia

Project Objectives: 1. Improving yield and water use efficiency of the wheat crop, the backbone of the Australia grains industry, by better matching management, variety, soil and climate. The aim is thus increasing kg grain/ha per mm evapotranspiration and kg grain/ha per mm rain. 2. Improving land and water productivity and profit by better arrangement of the components of the cropping system. This involves better allocation of farm resources (land, water, machinery, labour) and identifying strategies that account for trade-offs between profit and risk. The aim is thus improving $/ha per year and mm rain in a risk framework.

Optimising crop and economic performance of precision overhead irrigation

This project aims to develop integrated irrigation and nutrition management strategies under limited water for irrigators currently investing in overhead irrigation systems (CPLM) to minimize the learning lag in their use and optimize crop and economic performance.

The intrinsic plasticity of farm businesses and their resilience to change. An Australian example.

This paper examines the idea that plasticity in farm management introduces resilience to change and allows farm businesses to perform when operating in highly variable environments. We also argue for the need to develop and apply more integrative assessments of farm performance that combine the use of modelling tools with deliberative processes involving farmers and researchers in a co-learning process, to more effectively identify and implement more productive and resilient farm businesses. In a plastic farming system, farm management is highly contingent on environmental conditions. In plastic farming systems farm managers constantly vary crops and inputs based on the availability of limited and variable resources (e.g. land, water, finances, labour, machinery, etc.), and signals from its operating environment (e.g. climate, markets), with the objective of maximising a number of, often competing, objectives (e.g. maximise profits, minimise risks, etc.). In contrast in more rigid farming systems farm management is more calendar driven and relatively fixed sequences of crops are regularly followed over time and across the farm. Here we describe the application of a whole farm simulation model to (i) compare, in silico, the sensitivity of two farming systems designs of contrasting levels of plasticity, operating in two contrasting environments, when exposed to a stressor in the form of climate change scenarios;(ii) investigate the presence of interactions and feedbacks at the field and farm levels capable of modifying the intensity and direction of the responses to climate signals; and (iii) discuss the need for the development and application of more integrative assessments in the analysis of impacts and adaptation options to climate change. In both environments, the more plastic farm management strategy had higher median profits and was less risky for the baseline and less intensive climate change scenarios (2030). However, for the more severe climate change scenarios (2070), the benefit of plastic strategies tended to disappear. These results suggest that, to a point, farming systems having higher levels of plasticity would enable farmers to more effectively respond to climate shifts, thus ensuring the economic viability of the farm business. Though, as the intensity of the stress increases (e.g. 2070 climate change scenario) more significant changes in the farming system might be required to adapt. We also found that in the case studies analysed here, most of the impacts from the climate change scenarios on farm profit and economic risk originated from important reductions in cropping intensity and changes in crop mix rather than from changes in the yields of individual crops. Changes in cropping intensity and crop mix were explained by the combination of reductions in the number of sowing opportunities around critical times in the cropping calendar, and to operational constraints at the whole farm level i.e. limited work capacity in an environment having fewer and more concentrated sowing opportunities. This indicates that indirect impacts from shifts in climate on farm operations can be more important than direct impacts from climate on the yield of individual crops. The results suggest that due to the complexity of farm businesses, impact assessments and opportunities for adaptation to climate change might also need to be pursued at higher integration levels than the crop or the field. We conclude that plasticity can be a desirable characteristic in farming systems operating in highly variable environments, and that integrated whole farm systems analyses of impacts and adaptation to climate change are required to identify important interactions between farm management decision rules, availability of resources, and farmer's preference.

Should I grow wildflowers? Agrilink, your growing guide to better farming

Each Agrilink kit has been designed to be both comprehensive and practical. As the kits are arranged to answer questions of increasing complexity, they are useful references for both new and experienced producers of specific crops. Agrilink integrates the technology of horticultural production with the management of horticultural enterprises. REPRINT INFORMATION - PLEASE READ! For updated information please call 13 25 23 or visit the website www.deedi.qld.gov.au (Select: Queensland Industries – Agriculture link) This publication has been reprinted as a digital book without any changes to the content published in 2000. We advise readers to take particular note of the areas most likely to be out-of-date and so requiring further research: see detailed information on first page of the kit. Even with these limitations we believe this information kit provides important and valuable information for intending and existing growers. This publication was last revised in 2000. The information is not current and the accuracy of the information cannot be guaranteed by the State of Queensland. This information has been made available to assist users to identify issues involved in the production of wildflowers. This information is not to be used or relied upon by users for any purpose which may expose the user or any other person to loss or damage. Users should conduct their own inquiries and rely on their own independent professional advice. While every care has been taken in preparing this publication, the State of Queensland accepts no responsibility for decisions or actions taken as a result of any data, information, statement or advice, expressed or implied, contained in this publication.

Fallow management Calculating the profitability of different fallow management options

The method used to manage a fallow can influence your overall farm profitability. The benefits of a well managed fallow include improved soil health, reduced weed control costs, a reduction in the number of machinery operations and an increase in sugarcane productivity. Growers generally have two main options for managing their fallow; 1) bare fallow or 2) rotational crop. A bare fallow predominantly involves the use of tillage or herbicides to keep the block free of weeds and volunteer cane. Growing a rotational crop generally uses legumes like soybeans or cowpeas because of their soil health and nitrogen benefits. This paper looks into some of these methods and the flow on effects on farm profitability. Fallow management should never be viewed in isolation, as it is an integral part of the cane farming system. In this analysis we will investigate the effect of fallow management and farming system practices on the whole of farm profitability. There are many factors to consider when looking at different fallow management options. These include the type of farming system practices used and the suitability of a legume crop to a particular situation. Legume crops may not be suited to all situations, therefore it is recommended to consult with your local agronomist for more specific advice. One method of examining the options is to work through an example. In this case we will look at four options that are based on some common fallow management and farming system practices used in the Herbert region.

Improving Flow-Insensitive Solutions for Non-Separable Dataflow Problems

Flow-insensitive solutions to dataflow problems have been known to be highly scalable; however also hugely imprecise. For non-separable dataflow problems this solution is further degraded due to spurious facts generated as a result of dependence among the dataflow facts. We propose an improvement to the standard flow-insensitive analysis by creating a generalized version of the dominator relation that reduces the number of spurious facts generated. In addition, the solution obtained contains extra information to facilitate the extraction of a better solution at any program point, very close to the flow-sensitive solution. To improve the solution further, we propose the use of an intra-block variable renaming scheme. We illustrate these concepts using two classic non-separable dataflow problems --- points-to analysis and constant propagation.