Applying discrete element modelling to vertical and horizontal shaft impact crushers

The PFC3D (particle flow code) that models the movement and interaction of particles by the DEM techniques was employed to simulate the particle movement and to calculate the velocity and energy distribution of collision in two types of impact crusher: the Canica vertical shaft crusher and the BJD horizontal shaft swing hammer mill. The distribution of collision energies was then converted into a product size distribution for a particular ore type using JKMRC impact breakage test data. Experimental data of the Canica VSI crusher treating quarry and the BJD hammer mill treating coal were used to verify the DEM simulation results. Upon the DEM procedures being validated, a detailed simulation study was conducted to investigate the effects of the machine design and operational conditions on velocity and energy distributions of collision inside the milling chamber and on the particle breakage behaviour. (C) 2003 Elsevier Ltd. All rights reserved.

Further evidence for the agreement between patients with stroke and their proxies on the Frenchay Activities Index

Objective: To determine item, subscale and total score agreement on the Frenchay Activities Index (FAI) between stroke patients and proxies six months after discharge from rehabilitation. Design: Prospective study design. Setting/subjects: Fifty patient-proxy pairs, interviewed separately, in the patient's residence. Main outcome measures: Modified FAI using 13 items. Individual FAI items, subscales and total score agreement as measured by weighted kappa and intraclass correlation coefficients (ICC). Results: Excellent agreement was found for the total FAI (ICC 0.87, 95% confidence interval (CI) 0.78-0.93), and domestic (ICC 0.85, 95% CI 0.73-0.91) and outdoor (ICC 0.87, 95% CI 0.78-0.95) subscales, with moderate agreement found for the work/leisure subscale (ICC 0.63, 95% CI 0.34-0.78). For the individual FAI items, good, moderate, fair and poor agreement was found for five, three, four and one item, respectively. The best agreement was for objective items of preparing meals, washing-up, washing clothes, shopping and driving. The poorest agreement was for participation in hobbies, social outings and heavy housework. Scoring biases associated with patient or proxy demographic characteristics were found. Female proxies, and those who were spouses, scored patients lower on domestic activities; male patients, and those who were younger, scored themselves higher on outdoor activities and higher patient FIM scores were positively correlated with higher FAI scores. Conclusions: While total and subscale agreement on the FAI was high, individual item agreement varied. Proxy scores should be used with caution due to bias.

Identifying the communication activities of older people with aphasia: Evidence from naturalistic observation

Background: Increasingly there is a call from clinicians and researchers for measures that document the impact of aphasia on a person's everyday communication. Do existing assessments of communication disability adequately sample communication activities relevant to our clients? Communication skills and networks change with age. A need exists to determine the everyday communication activities of older people and in particular those with aphasia. Aims: The primary aim of this study was to describe and compare the everyday communication activities of older people with aphasia and healthy older people who are living in the community. A secondary aim was to investigate the content validity of the American Speech-Language Hearing Association Functional Assessment of Communication Skills for Adults (ASHA FACS, 1997) for older Australians. Methods & Procedures: Naturalistic observation was the method of choice for detailing the everyday communication of 15 older people with chronic aphasia following stroke and a matched group of 15 healthy older people who were living in the community. Researchers, in the role of participant observer, took field notes for 8 hours, over three occasions within a week. A total of 240 hours of observation have been coded in terms of communication activity, topic, communication partners, and place of communication. A brief 5-day diary served to check the representativeness of the observational data. After each hour of observation, the researcher checked which ASHA FACS items had been observed. Outcomes & Results: Naturalistic observation provided a rich, rigorous, and systematic methodology for detailing the dynamics and complexities of authentic communication. The most common communication activities for both groups were conversations at home and in social groups. Real-life communication was revealed to serve the dual purposes of transaction and interaction. Results indicate that older people with aphasia engage in similar communication activities to healthy older people although differences were evident in the frequency of communication and in specific activities such as story telling, writing, commenting, and acknowledging. ASHA FACS items were generally relevant to older Australians living in the community. Conclusions: This study demonstrated that communication activity is multifaceted in terms of the type of communication and contextual factors. The observational data describe the effects of aphasia on a person's everyday communication activity and reveal the impact of aphasia on the social functions of communication including sharing information, maintaining and establishing relationships, and telling one's story. Functional communication assessment requires a greater focus on the interactional and uniquely interpersonal aspects of social communication.

Rites of passage: Understanding participation of children with developmental coordination disorder

Children with developmental coordination disorder (DCD) experience difficulty participating in the typical activities of childhood and are known to have a more sedentary pattern of activities than their peers. Little research has been done to investigate the impact of these deficits on the lives of children with DCD and the importance of their participation in the typical activities of childhood. This qualitative study explored the impact of the disorder and the importance of participation for children with DCD from the perspective of the parent. Twelve in-depth interviews were conducted with parents of children with DCD who attended a university clinic specializing in using the Cognitive Orientation to daily Occupational Performance (COOP) approach, a cognitive-based intervention. Findings revealed that incompetence in everyday activities had serious negative effects for the children. Conversely, intervention that was focused on enablement at the activity and participation level had a significant positive impact on the children's quality of life. Emerging themes highlighted the notion that performance competency played an important role in being accepted by peers and being able to be part of the group. As well, parents reported that successful participation built confidence in their children and allowed them to try other new activities. The World Health Organization's International Classification of Functioning, Disability, and Health provides a unique framework for analyzing and understanding the impact of the physical disability on the lives of families with children with DCD. Results illustrate how intervention that focuses on enabling children to choose their own functional goals in the area of physical activity has important implications for enabling participation and building the social networks of children with DCD. (C) 2003 Elsevier B.V. All rights reserved.

Motor and functional skills of children with developmental coordination disorder: A pilot investigation of measurement issues

This paper reports on the motor and functional outcomes of 20 children with developmental coordination disorder (DCD) aged 4-8 years consecutively referred to a pediatric physiotherapy service. Children with a Movement ABC (M-ABC) score less than the 15th percentile, and with no concurrent medical, sensory, physical, intellectual or neurological impairments, were recruited. The Motor Assessment Outcomes Model (MAOM) [Coster and Haley, Infants and Young Children 4 (1992) 11] provided the theoretical base for measurement selection, and preliminary findings at the activities and participation levels of the model are reported in this article. Children with DCD performed at the lower end of the normal range on the Pea-body Developmental Motor Scales (fine motor total score) (M = 85.65, SD = 12.23). Performance on the Visual Motor Integration Test (VMI) standard scores was within the average range (M = 96.15, SD = 10.69). Videotaped observations of the children's writing and cutting indicated that 29% were left-handed and that a large proportion of all children (31%) utilized unusual pencil grasp patterns and immature prehension of scissors. Measurement at the participation level involved use of the Pictorial Scale of Perceived Competence and Social Acceptance (PCSA) and Pediatric Evaluation of Disability Inventory (PEDI). Overall, these young children rated themselves towards the more competent and accepted end of the PCSA over the dimensions of physical and cognitive competence and peer and maternal acceptance. The PEDI revealed generally average performance on social (M = 49.98, SD = 16.62) and mobility function (M = 54.71, SD = 3.99), however, self-care function was below the average range for age (M = 38.01, SD = 12.19). The utility of the MAOM as a framework for comprehensive measurement of functional and motor outcomes of DCD in young children is discussed. (C) 2003 Elsevier B.V. All rights reserved.

What influences the functional outcome of children at 6 months post-burn?

The contribution of demographic, injury, pre-morbid, and parent factors to a child's functional outcome at 6 months post-burn injury was examined. Sixty-eight children, aged 5-14 years with percent total body surface area (%TBSA) burns ranging from

The mouse secretome: functional classification of the proteins secreted into the extracellular environment

We have developed a computational strategy to identify the set of soluble proteins secreted into the extracellular environment of a cell. Within the protein sequences predominantly derived from the RIKEN representative transcript and protein set, we identified 2033 unique soluble proteins that are potentially secreted from the cell. These proteins contain a signal peptide required for entry into the secretory pathway and lack any transmembrane domains or intracellular localization signals. This class of proteins, which we have termed the mouse secretome, included >500 novel proteins and 92 proteins

Purification and characterisation of functional early pregnancy factor expressed in Sf9 insect cells and in Escherichia coli

Early pregnancy factor (EPF) is a secreted protein with growth regulatory and immunomodulatory properties. It is an extracellular form of the mitochondrial matrix protein chaperonin 10 (Cpn10), a molecular chaperone. An understanding of the mechanism of action of EPF and an exploration of therapeutic potential has been limited by availability of purified material. The present study was undertaken to develop a simple high-yielding procedure for preparation of material for structure/function studies, which could be scaled up for therapeutic application. Human EPF was expressed in Sf9 insect cells by baculovirus infection and in Escherichia coli using a heat inducible vector. A modified molecule with an additional N-terminal alanine was also expressed in E coli. The soluble protein was purified from cell lysates via anion exchange (negative-binding mode), cation exchange, and hydrophobic interaction chromatography, yielding similar to42 and 36 mg EPF from 300 ml bacterial and I L Sf9 cultures, respectively. The preparations were highly purified ( greater than or equal to99% purity on SDS-PAGE for the bacterial products and greater than or equal to97% for that of insect cells) and had the expected mass and heptameric structure under native conditions, as determined by mass spectrometry and gel permeation chromatography, respectively. All recombinant preparations exhibited activity in the EPF bioassay, the rosette inhibition test, with similar potency both to each other and to the native molecule. In two in vivo assays of immuno suppressive activity, the delayed-type hypersensitivity reaction and experimental autoimmune encephalomyelitis, the insect cell and modified bacterial products, both with N-terminal additions (acetylation or amino acid), exhibited similar levels of suppressive activity, but the bacterial product with no N-terminal modification had no effect in either assay. Studies by others have shown that N-terminal addition is not necessary for Cpn10 activity. By defining techniques for facile production of molecules with and without immunosuppressive properties, the present studies make it possible to explore mechanisms underlying the distinction between EPF and Cpn10 activity. (C) 2003 Elsevier Inc. All rights reserved.

How does residue management impact soil organic matter composition and quality under Eucalyptus globulus plantations in southwestern Australia?

This study investigated the influence of harvest residue management practices on soil organic matter (SOM) composition and quality from two second-rotation Eucalyptus globulus plantations in southwestern Australia, using solid-state 13C nuclear magnetic resonance (NMR) spectroscopy with cross-polarisation and magic-angle-spinning (CPMAS). Soil samples (0–5 cm) were collected every 12 months for 5 years from two sites that had contrasting soil types and fertility. Harvest residue management treatments established at both sites were (a) no harvest residues; and (b) double harvest residues. The use of 13C CPMAS and DD NMR spectroscopy enabled the successful non-destructive detection of SOM quality changes in the two E. globulus plantations. Relative intensities of 13C CPMAS NMR spectral regions were similar at both sites, and for both harvest residue treatments, indicating that SOM composition was also similar. Dipolar dephasing (DD) NMR spectra revealed resonances in SOM assigned to lignin and tannin structures, with larger resonances in the carbonyl and alkyl C regions that were indicative of cuticular material, enabling detection of changes in SOM quality. Retention of double harvest residues on the soil surface increased the soil quality compared with removal of all harvest residues at both sites as indicated by the NMR aromaticities, but this was most noticeable at Manjimup, which had greater initial soil fertility.

Molecular and functional characterization of an octopamine receptor from honeybee (Apis mellifera) brain

Biogenic amines and their receptors regulate and modulate many physiological and behavioural processes in animals. In vertebrates, octopamine is only found in trace amounts and its function as a true neurotransmitter is unclear. In protostomes, however, octopamine can act as neurotransmitter, neuromodulator and neurohormone. In the honeybee, octopamine acts as a neuromodulator and is involved in learning and memory formation. The identification of potential octopamine receptors is decisive for an understanding of the cellular pathways involved in mediating the effects of octopamine. Here we report the cloning and functional characterization of the first octopamine receptor from the honeybee, Apis mellifera . The gene was isolated from a brain-specific cDNA library. It encodes a protein most closely related to octopamine receptors from Drosophila melanogaster and Lymnea stagnalis . Signalling properties of the cloned receptor were studied in transiently transfected human embryonic kidney (HEK) 293 cells. Nanomolar to micromolar concentrations of octopamine induced oscillatory increases in the intracellular Ca2+ concentration. In contrast to octopamine, tyramine only elicited Ca2+ responses at micromolar concentrations. The gene is abundantly expressed in many somata of the honeybee brain, suggesting that this octopamine receptor is involved in the processing of sensory inputs, antennal motor outputs and higher-order brain functions.

Clinical and economic impact of exercise electrocardiography and exercise echocardiography in clinical practice

Background Patients with known or suspected coronary disease are often investigated to facilitate risk assessment. We sought to examine the cost-effectiveness of strategies based on exercise echocardiography and exercise electrocardiography. Methods and results We studied 7656 patients undergoing exercise testing; of whom half underwent exercise echocardiography. Risk was defined with the Duke treadmill score for those undergoing exercise electrocardiography alone, and by the extent of ischaemia by exercise echocardiography. Cox proportional hazards models, risk adjusted for pretest likelihood of coronary artery disease, were used to estimate time to cardiac death or myocardial infarction. Costs (including diagnostic and revascularisation procedures, hospitalisations, and events) were calculated, inflation-corrected to year 2000 using Medicare trust fund rates and discounted at a rate of 5%. A decision model was employed to assess the marginal cost effectiveness (cost/life year saved) of exercise echo compared with exercise electrocardiography. Exercise echocardiography identified more patients as low-risk (51% vs 24%, p<0.001), and fewer as intermediate- (27% vs 51%, p<0.001) and high-risk (22% vs 4%); survival was greater in low- and intermediate- risk and less in high-risk patients. Although initial procedural costs and revascularisation costs (in intermediate- high risk patients) were greater, exercise echocardiography was associated with a greater incremental life expectancy (0.2 years) and a lower use of additional diagnostic procedures when compared with exercise electrocardiography (especially in lower risk patients). Using decision analysis, exercise echocardiography (Euro 2615/life year saved) was more cost effective than exercise electrocardiography. Conclusion Exercise echocardiography may enhance cost-effectiveness for the detection and management of at risk patients with known or suspected coronary disease. (C) 2003 Published by Elsevier Science Ltd on behalf of The European Society of Cardiology.