789 research outputs found

    Chiral Condensate and Short-Time Evolution of QCD(1+1) on the Light-Cone

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    Chiral condensates in the trivial light-cone vacuum emerge if defined as short-time limits of fermion propagators. In gauge theories, the necessary inclusion of a gauge string in combination with the characteristic light-cone infrared singularities contain the relevant non-perturbative ingredients responsible for formation of the condensate, as demonstrated for the 't Hooft model.Comment: 4 pages, Revtex

    Torres Strait Finfish Fishery: Spanish Mackerel stock assessment, with data to June 2021. Year one report.

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    Spanish mackerel, Scomberomorus commerson, sustain an important finfish line fishery within the Torres Strait and are managed as a single stock. In these waters the species have been recorded to live for up to 13 years, weigh in excess of 20 kg and mature from two years of age. The Australian Fisheries Management Authority (AFMA) commissioned annual updates to the Torres Strait Spanish mackerel stock assessment for three years 2021–2023. This was to monitor biomass estimates that were close to the 20 percent limit reference point for declaring an overfished stock. Across analyses of different fish natural mortality and harvest, the median estimated spawning biomass of Spanish mackerel in 2020 was 29 percent of unfished estimates at the start of the fishery in 1940. The low biomass result was due to the high harvests between 1980 and 2006 and the downturn in Spanish mackerel catch rates 2010–2019. The 2022–2023 recommended biological catch (RBC) of Spanish mackerel for all fishing sectors in the Torres Strait was 95 t based on the median forecast estimate (Table 1). This RBC was forecast to build Spanish mackerel towards a target biomass of 48% within 12 years, and have less than 10% risk of reducing to the 20% biomass limit reference point. The assessment work also initiated the first comparison of the packaged stock assessment software stock synthesis (SS), which was used for assessing Australian east coast and Gulf of Carpentaria Spanish mackerel. The SS estimate of spawning biomass ratio in 2020 was similar compared against the current model developed by the Department of Agriculture and Fisheries and reported herein. SS performance and results will be further tested in years two and three of this AFMA project, noting that future provision of a streamlined stock assessment is to transition to stock synthesis after TSFFRAG review

    Torres Strait Finfish Fishery: Spanish Mackerel stock assessment, with data to June 2021. Year one report.

    Get PDF
    Spanish mackerel, Scomberomorus commerson, sustain an important finfish line fishery within the Torres Strait and are managed as a single stock. In these waters the species have been recorded to live for up to 13 years, weigh in excess of 20 kg and mature from two years of age. The Australian Fisheries Management Authority (AFMA) commissioned annual updates to the Torres Strait Spanish mackerel stock assessment for three years 2021–2023. This was to monitor biomass estimates that were close to the 20 percent limit reference point for declaring an overfished stock. Across analyses of different fish natural mortality and harvest, the median estimated spawning biomass of Spanish mackerel in 2020 was 29 percent of unfished estimates at the start of the fishery in 1940. The low biomass result was due to the high harvests between 1980 and 2006 and the downturn in Spanish mackerel catch rates 2010–2019. The 2022–2023 recommended biological catch (RBC) of Spanish mackerel for all fishing sectors in the Torres Strait was 95 t based on the median forecast estimate (Table 1). This RBC was forecast to build Spanish mackerel towards a target biomass of 48% within 12 years, and have less than 10% risk of reducing to the 20% biomass limit reference point. The assessment work also initiated the first comparison of the packaged stock assessment software stock synthesis (SS), which was used for assessing Australian east coast and Gulf of Carpentaria Spanish mackerel. The SS estimate of spawning biomass ratio in 2020 was similar compared against the current model developed by the Department of Agriculture and Fisheries and reported herein. SS performance and results will be further tested in years two and three of this AFMA project, noting that future provision of a streamlined stock assessment is to transition to stock synthesis after TSFFRAG review

    Data Presentation in Security Operations Centres: Exploring the Potential for Sonification to Enhance Existing Practice

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    Security practitioners working in Security Operations Centres (SOCs) are responsible for detecting and mitigating malicious computer-network activity. This work requires both automated tools that detect and prevent attacks, and data-presentation tools that can present pertinent network-security monitoring information to practitioners in an efficient and comprehensible manner. In recent years, advances have been made in the development of visual approaches to data presentation, with some uptake of advanced security visualization tools in SOCs. Sonification, in which data is represented as sound, is said to have potential as an approach that could work alongside existing visual data-presentation approaches to address some of the unique challenges faced by SOCs. For example, sonification has been shown to enable peripheral monitoring of processes, which could aid practitioners multitasking in busy SOCs. The perspectives of security practitioners on incorporating sonification into their actual working environments have not yet been examined, however. The aim of this paper therefore is to address this gap by exploring attitudes to using sonification in SOCs, and identifying the data-presentation approaches currently used. We report on the results of a study consisting of an online survey (N=20) and interviews (N=21) with security practitioners working in a range of different SOCs. Our contributions are (1) a refined appreciation of the contexts in which sonification could aid in SOC working practice, (2) an understanding of the areas in which sonification may not be beneficial or may even be problematic, (3) an analysis of the critical requirements for the design of sonification systems and their integration into the SOC setting, and (4) evidence of the visual data-presentation techniques currently used and identification of how sonification might work alongside and address challenges to using them. Our findings clarify insights into the potential benefits and challenges of introducing sonification to support work in this vital security-monitoring environment. Participants saw potential value in using sonification systems to aid in anomaly-detection tasks in SOCs (such as retrospective hunting), as well as in situations in which peripheral monitoring is desirable: while multitasking with multiple work tasks, or while outside of the SOC

    Managing yield decline in sugarcane cropping systems

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    This paper summarises the results from ten years of yield decline research carried out by the Sugar Yield Decline Joint Venture in the Australian sugar industry. The research concludes that, although the ultimate expression of yield decline may be through adverse effects of pathogens on sugarcane root systems, yield decline is a complex issue caused by a number of factors being out of balance in the sugarcane cropping system. Soil degradation has been the result of the long-term sugarcane monoculture and how it has been practiced. Specific research has shown that the long-term monoculture, uncontrolled traffic from heavy machinery and excessive tillage along with practices that deplete organic matter all contribute to yield decline. It is argued that changes to the cropping system that will conserve organic matter, break the monoculture, control traffic and minimize tillage are the most appropriate ways to combat yield decline. The technology is now available to incorporate these changes into the cropping system and a more sustainable, profitable and environmentally responsible cropping system is proposed. The proposed system is not prescriptive and many acceptable variations will be just as suitable providing the basic principles of organic matter conservation, breaking the monoculture, controlling traffic and minimizing tillage are no compromised

    Protein hydrolysates and recovery of muscle damage following eccentric exercise

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    Background: A whey protein hydrolysate (NatraBoost XR; WPHNB) has been shown to speed repair muscle damage. We sought to determine whether this benefit is specific to this hydrolysate to evaluate a marker for quality control. Methods: Three hydrolysates of the same whey protein isolate (WPI) were prepared (WPHNB, WPH1 and WPH2). Isometric knee extensor strength was measured in 39 sedentary male participants before and after 100 maximal eccentric contractions of the knee extensors to induce muscle damage. Participants were then randomised to consume 250 ml of flavoured water (FW, n=9), or 250 ml of FW containing 25 g of either NatraBoost XR (n=3), WPH1 (n=9), WPH2 (n=9) or WPI (n=9). Strength was reassessed over the next seven days while the supplements were consumed daily. Fibroblasts were cultured for 48 hr in the presence of the different hydrolysates, WPI, saline or fetal bovine serum to ascertain effects on cell proliferation. Results: Strength was reduced in all treatment groups after eccentric exercise (P<0.001). Strength recovered steadily over 7 days in the FW, WPI, WPH1 and WPH2 treatment groups (P<0.001), with no difference between treatments (P=0.87). WPHNB promoted faster strength recovery compared with the other treatments (P<0.001). Fibroblast proliferation was greater with WPHNB compared with saline, WPI or the other hydrolysates (P<0.001). Conclusions: Promoting recovery from muscle damage seems unique to WPHNB. In vitro fibroblast proliferation may be a useful marker for quality control. It is not clear whether effects on fibroblast proliferation contribute to the in vivo effect of WPHNB on muscle damage

    Economic and Conservation Evaluation of Capital Renovation Projects: Hidalgo County Irrigation District No. 1 (Edinburg) - North Branch / East Main - Final

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    Initial construction costs and net annual changes in operating and maintenance expenses are identified for a single-component capital renovation project proposed by Hidalgo County Irrigation District No. 1 to the Bureau of Reclamation and North American Development Bank. The proposed project involves installing 4.83 miles of multi-size pipeline to replace a segment of the North Branch / East Main canal. Both nominal and real estimates of water and energy savings and expected economic and financial costs of those savings are identified throughout the anticipated 48-year useful life for the proposed project. Sensitivity results for both the cost of water savings and cost of energy savings are presented for several important parameters. Annual water and energy savings forthcoming from the total project are estimated, using amortization procedures, to be 5,838 ac-ft of water per year and 3,293,049,926 BTUs (965,138 kwh) of energy per year. The calculated economic and financial cost of water savings is estimated to be 15.58perac−ft.Thecalculatedeconomicandfinancialcostofenergysavingsisestimatedat15.58 per ac-ft. The calculated economic and financial cost of energy savings is estimated at 0.0000392 per BTU (0.134perkwh).Inaddition,expectedreal(ratherthannominal)valuesareindicatedfortheBureauofReclamation’sthreeprincipalevaluationmeasuresspecifiedintheUnitedStatesPublicLaw106−576legislation.Theinitialconstructioncostperac−ftofwatersavingsmeasureis0.134 per kwh). In addition, expected real (rather than nominal) values are indicated for the Bureau of Reclamation’s three principal evaluation measures specified in the United States Public Law 106-576 legislation. The initial construction cost per ac-ft of water savings measure is 30.68 per ac-ft of water savings. The initial construction cost per BTU (kwh) of energy savings measure is 0.0000544perBTU(0.0000544 per BTU (0.186 per kwh). The ratio of initial construction costs per dollar of total annual economic savings is estimated to be -1.58

    A review of psychiatric co-morbidity described in genetic and immune mediated movement disorders

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    Psychiatric symptoms are an increasingly recognised feature of movement disorders. Recent identification of causative genes and autoantibodies has allowed detailed analysis of aetiologically homogenous subgroups, thereby enabling determination of the spectrum of psychiatric symptoms in these disorders. This review evaluates the incidence and type of psychiatric symptoms encountered in patients with movement disorders. A broad spectrum of psychiatric symptoms was identified across all subtypes of movement disorder, with depression, generalised anxiety disorder and obsessive-compulsive disorder being most common. Psychosis, schizophrenia and attention deficit hyperactivity disorder were also identified, with the psychiatric symptoms often predating onset of the motor disorder. The high incidence of psychiatric symptoms across such a wide range of movement disorders suggests a degree of common or overlapping pathogenic mechanisms. Our review demonstrates the need for increased clinical awareness of such co-morbidities, which should facilitate early neuropsychiatric intervention and allied specialist treatment for patients

    Structural studies into the spin crossover behaviour of Fe(abpt)2(NCS)2 polymorphs B and D

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    The spin-crossover behaviour of [Fe(abpt)2(NCS)2] (abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole) polymorphs B and D has been studied using single crystal X-ray diffraction to monitor changes in structural features. High pressure single crystal measurements on polymorph B showed that it underwent a monoclinic P21/n (Z′ = 0.5) to triclinic P-1 (Z′ = 2 × 0.5) phase transition between 11.5 and 13.5 kbar, at which point it also starts to undergo a thermally inaccessible spin crossover. In polymorph D which also crystallises in the mononclinic space group P21/n (Z′ = 2 × 0.5) one of the unique Fe centres undergoes a thermal spin transition. It also displays light-induced excited spin-state trapping (LIESST), and a structure has been obtained at 30 K through continuous irradiation with a 670 nm 5 mW CW laser. In addition high pressure single crystal measurements on polymorph D showed a stepped pressure induced spin transition. At ∼9.6 kbar one of the unique Fe centres had undergone a spin transition and by ∼15 kbar both of the unique Fe centres are shown to be essentially low spin, a situation that is thermally inaccessible. Crystallographic data were collected for both polymorphs using variable temperature or high pressure single crystal X-ray diffraction to allow changes in cell parameters, bond lengths and distortion parameters to be monitored for the spin crossover or phase transition

    Validation of flank-to-flank allometric equations in predicting weight of lactating sows and lactation weight change

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    The objectives of this study were to validate the use of flank-to-flank measurement in predicting weight of lactating sows and to determine the accuracy of the developed models in estimating lactation weight change. A total of 70 lactating sows (PIC Line 1050) were used in this study. Flank-to-flank measurement and body weight were measured on each individual sow after farrowing and at weaning. Flank-to-flank measurement and weight of lactating sows was positively correlated (R2 = 0.61; P<.0001) with the following equation: BW0.33, kg = 0.0371 x Flank-to-flank (cm) + 2.161. Weights of sows post-farrowing and at weaning were lower (P<0.03) when predicted with the previous allometric model developed from growing pigs and sows than their actual weights or weights predicted using the lactating sow model. Likewise, absolute residuals for post-farrowing and weaning weights using a previous allometric model developed from growing pigs and gestating sows were greater (P<0.02) than those of the lactating sow model. There were no differences (P<0.89) between the predicted weights using the lactating sow model and their actual weights. There also were no differences between the actual average weight loss (P<0.14) and the predicted loss using the lactating sow model. Using the model previously developed with growing pigs and gestating sows resulted in 15.5 lb (P<0.007) greater than the actual average weight loss. In conclusion, flank-to-flank measurement can be used as a predictor of weight of lactating sows, with the relationship having less accuracy than those used for growing-finishing pigs, gestating sows, and boars. The pig allometric equation cannot be used to estimate weights of lactating sows and lactation weight change. The developed lactating sow model was more appropriate in estimating weights and weight loss at the herd level, but needs to be validated on other sows before use can be recommended
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