Slurry flow in mills: grate-only discharge mechanism (Part-1)

Discharge grates play an important role in determining the performance of autogenous, semi-autogenous and grate discharge ball mills. The flow capacity (grinding capacity) of these mills is strongly influenced by the discharge grate design-open area and position of apertures, as well as the performance of the pulp lifters. As mill sizes have progressively increased and closed-circuiting has become more popular the importance of grate and pulp lifter design has grown. Unfortunately very few studies have concentrated on this aspect of mill performance. To remedy this a series of laboratory and pilot-scale tests were undertaken to study both the performance of grates on their own and in conjunction with pulp lifters. In this first paper of a two-part series the results from the grate-only experiments are presented and discussed, whilst the performance of the grate-pulp-lifter system is covered in the second paper. The results from the grate-only experiments have shown that the build-up of slurry (hold-up) inside the mill starts from the shoulder of the charge, while the toe position of the slurry progressively moves towards the toe of the charge with increasing flowrate. Besides grate design (open area and position of apertures), charge volume and mill speed were also found to have a strong influence on mill hold-up and interact with grate design variables. (C) 2003 Elsevier Science Ltd. All rights reserved.

Inter-relationships between rheumatoid arthritis and periodontal disease

This review considers the considerable similarities between periodontal disease and rheumatoid arthritis (RA). While the etiology of these two diseases may differ, the underlying pathogenic mechanisms are remarkably similar and it is possible that individuals manifesting both periodontitis and RA may suffer from a unifying underlying systemic dysregulation of the inflammatory response. In light of these findings, the implications for the use of disease-modifying medications in the management of these two chronic inflammatory conditions is apparent. Further longitudinal studies and medication-based intervention studies are required to determine just how closely these two conditions are allied.

Phylogenetic relationships of Hepatozoon (Haemogregarina) boigae Hepatozoon sp. Haemogregarina clelandi and Haemoproteus chelodina from Australian reptiles to other Apicomplexa based on cladistic analyses of ultrastructural and life-cycle characters

The phylogeny of representative haemozoan species of the phylum Apicomplexa was reconstructed by cladistic analyses of ultrastructural and life-cycle characteristics. The analysis incorporated 4 apicomplexans previously not included in phylogenetic reconstructions: Haemogregarina clelandi from the Brisbane River tortoise (Emydura signata), Hepatozoon sp. from the slaty grey snake (Stegonotus cucullatus), Hepatozoon (Haemogregarina) boigae from the brown tree snake (Boiga irregularis), and Haemoproteus chelodina from the saw-shelled tortoise (Elseya latisternum). There was no apparent correlation between parasite phylogeny and that of their vertebrate hosts, but there appeared to be some relationship between parasites and their intermediate hosts, suggestive of parasite/vector co-evolution.

Database technologies for l-system simulations in virtual plant applications on bioinformatics

One of the most important advantages of database systems is that the underlying mathematics is rich enough to specify very complex operations with a small number of statements in the database language. This research covers an aspect of biological informatics that is the marriage of information technology and biology, involving the study of real-world phenomena using virtual plants derived from L-systems simulation. L-systems were introduced by Aristid Lindenmayer as a mathematical model of multicellular organisms. Not much consideration has been given to the problem of persistent storage for these simulations. Current procedures for querying data generated by L-systems for scientific experiments, simulations and measurements are also inadequate. To address these problems the research in this paper presents a generic process for data-modeling tools (L-DBM) between L-systems and database systems. This paper shows how L-system productions can be generically and automatically represented in database schemas and how a database can be populated from the L-system strings. This paper further describes the idea of pre-computing recursive structures in the data into derived attributes using compiler generation. A method to allow a correspondence between biologists' terms and compiler-generated terms in a biologist computing environment is supplied. Once the L-DBM gets any specific L-systems productions and its declarations, it can generate the specific schema for both simple correspondence terminology and also complex recursive structure data attributes and relationships.

Effect of alcohol on iron storage diseases of the liver

The consumption of excess alcohol in patients with liver iron storage diseases, in particular the iron-overload disease hereditary haemochromatosis (HH), has important clinical consequences. HH, a common genetic disorder amongst people of European descent, results in a slow, progressive accumulation of excess hepatic iron. If left untreated, the condition may lead to fibrosis, cirrhosis and primary hepatocellular carcinoma. The consumption of excess alcohol remains an important cause of hepatic cirrhosis and alcohol consumption itself may lead to altered iron homeostasis. Both alcohol and iron independently have been shown to result in increased oxidative stress causing lipid peroxidation and tissue damage. Therefore, the added effects of both toxins may exacerbate the pathogenesis of disease and impose an increased risk of cirrhosis. This review discusses the concomitant effects of alcohol and iron on the pathogenesis of liver disease. We also discuss the implications of co-existent alcohol and iron in end-stage liver disease.

Effectiveness of case management and post-acute services in older people after hospital discharge

Objective: To evaluate the benefits of coordinating community services through the Post-Acute Care (PAC) program in older patients after discharge from hospital. Design: Prospective multicentre, randomised controlled trial with six months of follow-up with blinded outcome measurement. Setting: Four university-affiliated metropolitan general hospitals in Victoria. Participants: All patients aged 65 years and over who were discharged between August 1998 and October 1999 and required community services after discharge. Interventions: Participants were randomly allocated to receive services of a Post-Acute Care (PAC) coordinator (intervention) versus usual discharge planning (control). Main outcome measures: Comparison of quality of life and carer stress at one-month post-discharge, mortality, hospital readmissions, use of community services and community and hospital costs over the six months post-discharge. Results: 654 patients were randomised, and 598 were included in the analysis (311 in the PAC group and 287 in the control group). There was no difference in mortality between the groups (both 6%), but significantly greater overall quality-of-life scores at one-month follow-up in the PAC group. There was no difference in unplanned readmissions, but PAC patients used significantly fewer hospital bed-days in the six months after discharge (mean, 3.0 days; 95% CI, 2.1-3.9) than control patients (5.2 days; 95% CI, 3.8-6.7). Total costs (including hospitalisation, community services and the intervention) were lower in the PAC than the control group (mean difference, $1545; 95% CI, $11-$3078). Conclusions: The PAC program is beneficial in the transition from hospital to the community in older patients.

Effect of storage time and conditions on the seed coat colour of Australian adzuki beans

Two varieties of adzuki beans (Vigna angularis), Bloodwood and Erimo, were stored at temperatures of 10, 20 or 30degreesC, and relative humidities (RH) 40 or 65%, and samples were analysed at 0, 1.5, 3 and 6 months. Storage at 30degreesC for > 1.5 months caused a significant decrease in the a(star) and b(star) colour values and darkening of the seed coat. Beans stored at 65% RH had lower L-star but higher a(star) and b(star) colour values than those stored at 40% RH. Bloodwood and Erimo samples showed similar trends in colour during storage. The best storage conditions for the preservation of the adzuki colour were 10degreesC and 65% RH. The Australian beans had lower L-star, a(star) and b(star) colour values than Japanese Erimo-shouzu beans and storage increased the difference.

Effect of storage time and conditions on the cotyledon cell wall of the adzuki bean (Vigna angularis)

Two varieties of adzuki grown in Australia, Bloodwood and Erimo, were stored for up to 6 months at three temperatures (10, 20 and 30 degreesC), and two relative humidities (RH; 40 and 65%). The amount of cell wall material increased with time under all storage conditions. This increase was greatest at 30 degreesC and 40% RH. Storage time and conditions did not affect the total pectin levels in the cell wall. Erimo constantly exhibited a higher total pectin level than Bloodwood. The Bloodwood soluble pectin, Ca++ and Mg++ and Erimo Ca++ in the cell wall remained stable during storage, while the Erimo soluble pectin and Mg++ exhibited a slight decrease at 20 and 30 degreesC after 3 months of storage. (C) 2002 Elsevier Science Ltd. All rights reserved.

Emergence of joint attention: Relationships between gaze following, social referencing, imitation, and naming in infancy

The authors investigated the extent to which the joint-attention behaviors of gaze following, social referencing, and object-directed imitation were related to each other and to infants vocabulary development in a sample of 60 infants between the ages of 8 and 14 months. Joint-attention skills and vocabulary development were assessed in a laboratory setting. Split-half reliability analyses on the joint-attention measures indicated that the tasks reliably assessed infants' capabilities. In the main analysis, no significant correlations were found among the joint-attention behaviors except for a significant relationship between gaze following and the number of names in infants' productive vocabularies. The overall pattern of results did not replicate results of previous studies (e.g., M. Carpenter, K. Nagell, & M. Tomasello, 1998) that found relationships between various emerging joint-attention behaviors.