Colourful objects through animal eyes

To understand how bees, birds, and fish may use colour vision for food selection and mate choice, we reconstructed views of biologically important objects taking into account the receptor spectral sensitivities. Reflectance spectra a of flowers, bird plumage, and fish skin were used to calculate receptor quantum catches. The quantum catches were then coded by red, green, and blue of a computer monitor; and powers, birds, and fish were visualized in animal colours. Calculations were performed for different illumination conditions. To simulate colour constancy, we used a von Kries algorithm, i.e., the receptor quantum catches were scaled so that the colour of illumination remained invariant. We show that on land this algorithm compensates reasonably well for changes of object appearance caused by natural changes of illumination, while in water failures of von Kries colour constancy are prominent. (C) 2000 John Wiley & Sons, Inc.

A systematic study of the microwave and thermal cure kinetics of the TGDDM/DDS and TGDDM/DDM epoxy-amine resin systems

The microwave and thermal cure processes for the epoxy-amine systems N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenyl methane (TGDDM) with diaminodiphenyl sulfone (DDS) and diaminodiphenyl methane (DDM) have been investigated. The DDS system was studied at a single cure temperature of 433 K and a single stoichiometry of 27 wt% and the DDM system was studied at two stoichiometries, 19 and 32 wt%, and a range temperatures between 373 and 413 K. The best values the kinetic rate parameters for the consumption of amines have been determined by a least squares curve Ft to a model for epoxy-amine cure. The activation energies for the rate parameters for the MY721/DDM system were determined as was the overall activation energy for the cure reaction which was found to be 62 kJ mol(-1). No evidence was found for any specific effect of the microwave radiation on the rate parameters, and the systems were both found to be characterized by a negative substitution effect. Copyright (C) 2001 John Wiley & Sons, Ltd.

Comparison of differentiated dendritic cell infiltration of autoimmune and osteoarthritis synovial tissue

Objective. Infiltration of rheumatoid arthritis (RA) synovial tissue (ST) by differentiated dendritic cells (DC) is a consistent feature in patients with active disease. However, mononuclear cells (MNC), including DC, may be nonspecifically chemoattracted to inflammatory sites regardless of etiology, Therefore, to evaluate the specificity of ST infiltration by differentiated DC, synovial biopsies from patients with RA, spondylarthropathy (SpA), osteoarthritis (OA), and gout were examined. Methods. Formalin-fixed ST sections were analyzed by double immunohistochemical staining for vascularity and infiltration by differentiated DC, lymphocytes, and macrophages. Results, DC containing nuclear RelB were found in perivascular MNC aggregates from patients with all arthritides studied. Infiltration by differentiated DC was similar in RA and SpA ST, but reduced in OA ST. Differentiated DC were always observed in close association with lymphocytes, and the correlation between these variables suggested that the infiltration of inflammatory sites by DC and lymphocytes was associated. Conclusion, Perivascular infiltration by DC, lymphocytes, and macrophages is nonspecifically related to inflammation, but signals present in RA and SpA ST lead to more intense cellular infiltration and accumulation.

Work-related stress and occupational therapy

Occupational stress and burnout have been studied extensively in the human services. It has been suggested that healthcare professionals in particular are at risk of stress owing to the caring nature of their work. Articles related to occupational therapy and work-related stress were reviewed in regard to practice in Australia, Canada, the United Kingdom, the United States and Sweden. Although the empirical literature is relatively weak for occupational therapy, it has been argued that occupational therapists in health care share risk factors with other healthcare professionals. These risk factors include repeated exposure to distress and difficult behaviour, prolonged interventions and uncertain outcome. Issues such as professional status, staffing issues and the nature of the profession have been identified as additional risk factors for occupational therapists. However, empirical studies that enable burnout rates of occupational therapists to be compared with those of related occupational groups suggest that this may not be the case. Occupational therapists may in fact be protected from some stress and burnout factors. Further research is recommended to clarify the nature of stress experienced by occupational therapists and to identify both risk and protective factors characteristic of the profession. Copyright © 2001 Whurr Publishers Ltd.

Incremental parsing in language-based editors: user needs and how to meet them

Incremental parsing has long been recognized as a technique of great utility in the construction of language-based editors, and correspondingly, the area currently enjoys a mature theory. Unfortunately, many practical considerations have been largely overlooked in previously published algorithms. Many user requirements for an editing system necessarily impact on the design of its incremental parser, but most approaches focus only on one: response time. This paper details an incremental parser based on LR parsing techniques and designed for use in a modeless syntax recognition editor. The nature of this editor places significant demands on the structure and quality of the document representation it uses, and hence, on the parser. The strategy presented here is novel in that both the parser and the representation it constructs are tolerant of the inevitable and frequent syntax errors that arise during editing. This is achieved by a method that differs from conventional error repair techniques, and that is more appropriate for use in an interactive context. Furthermore, the parser aims to minimize disturbance to this representation, not only to ensure other system components can operate incrementally, but also to avoid unfortunate consequences for certain user-oriented services. The algorithm is augmented with a limited form of predictive tree-building, and a technique is presented for the determination of valid symbols for menu-based insertion. Copyright (C) 2001 John Wiley & Sons, Ltd.

Extraction and purification of the zwitterions cylindrospermopsin and deoxycylindrospermopsin from Cylindrospermopsis raciborskii

The hepatotoxin cylindrospermopsin (CYN) has been isolated from the cyanobacterium Cylindrospermopsis raciborskii (C. raci.). Efforts to study this toxin have been hampered by the time-consuming requirement to extract it from cultures of the organism. It is usually extracted from lyophilized cells collected from a laboratory culture. Our preliminary work suggested far more of the toxin is available in solution in the culture media than in the cells collected. We have therefore investigated the use of commercially available solid phase extraction sorbents to extract CYN from culture media in which C. raci. has been grown. A range of reverse phase and ion-exchange sorbents were tested across a range of pHs for their ability to retain CYN without success. Subsequently, graphitized carbon cartridges were found to retain CYN strongly. Elution with 5% formic acid in methanol allowed the CYN to be regained for final purification by HPLC. Deoxy-CYN, an analog of CYN can also be extracted using this procedure. (C) 2001 John Wiley & Sons, Inc.

Sex-biased hatching sequences in the cooperatively breeding Noisy Miner

The Noisy Miner Manorina melanocephala (Meliphagidae) is a cooperatively breeding bird species in which sons often remain on their natal home ranges and help one or both of their parents. In a population of Noisy Miners in SE Queensland, Australia, a molecular technique was used to explore adult and offspring sex ratios. and also hatching sequences. Among the adult population, there were 2.31 males for every female, and roughly 99% of helping was performed by males. At hatching and fledging, the population sex ratio was even, with exactly 57 males and 57 females. However, in 17 out of 18 broods the first egg to hatch was male, First-hatched males were significantly larger and heavier than their sisters just prior to fledging. Through their helping behaviour, large healthy sons could clearly enhance the future reproductive success of parents. and benefit the entire group. Sex-biased hatching sequences could potentially provide cooperatively breeding birds with a subtle and precise way of varying investment in the helping sex.

Dieting and health in young Australian women

This paper examines the prevalence of dieting behaviours and correlates with physical and mental health in young Australian women who are participants in the Australian Longitudinal Stud of Women's Health. A total of 14 686 women aged 18-23 years, randomly selected from the National Medicare database, with over-sampling from rural and remote areas, responded to a questionnaire seeking dieting and health information. The results showed that 66.5 percent of the women had a BMI within the healthy weight range (18- < 25 kg/m(2)). However only 21.6 percent of these women were happy with their weight and almost half (46 percent) had dieted to lose weight in the last year (also one in five who had a BMI < 18.5 kg/m(2)). High frequency of dieting (rather than dieting per se) and earlier dieting onset were associated with poorer physical and mental health (including depression), more disordered eating (bingeing and purging), extreme weight and shape dissatisfaction and more frequent general health problems. The results suggest that there is a need for programmes that will enhance self esteem and weight/shape acceptance and promote more appropriate strategies for maintenance of healthy weight. Copyright (C) 2001 John Wiley & Sons, Ltd and Eating Disorders Association.

Distribution of C-14 Cylindrospermopsin in vivo in the mouse

Radiolabelled C-14 cylindrospermopsin (CYN) has been prepared and used to investigate the distribution and excretion of CYN in vivo in male Quackenbush mice. At a dose of 0.2 mg/kg (i.e., approx. median lethal dose) the following mean (SID) urinary and faecal recoveries (cumulative) were obtained, respectively: (0-6 hours, n = 4) 48.2 (29.3)%, 11.9 (21.4)%; (0-12 hours, n = 12) 66.0 (27.1)%, 5.7 (5.6)%; (0-24 hours, n = 12) 68.4 (26.7)%, 8.5 (8.1)%. Mean (SD) recoveries from livers at 6 hours were 20.6 (6.4)% (n = 4), at 48 hours 13.1 (7.7)% (n = 8), and 5-7 days were 2.1 (2.1)% (n = 8). A substantial amount (up to 23%) can be retained in the liver for up to 48 hours with a lesser amount retained in the kidneys. The excretion patterns show substantial interindividual variability between predominantly faecal or urinary excretion, but these patterns are not related in any simple manner to the outcome in terms of toxicity. There is at least one methanol-extractable metabolite as well as a nonmethanol-extractable metabolite in the liver. The methanol-extractable metabolite was not found in the kidney and is more hydrophilic than CYN itself on reverse phase. (C) 2001 by John Wiley & Sons, Inc.

Radioresistant Burkitt's lymphoma cells exhibit defective Mapk signalling

Using a pair of isogenic Burkitt's lymphoma cell lines, one of which is sensitive (BL30A) and the other resistant (BL30K) to apoptosis induced by ionising radiation and exogenous ceramide, we investigated mitogen-activated protein kinase (MAPK) signalling to determine which members of this kinase family are involved in the apoptotic process in these cells. We have previously shown that BL30A cells produce ceramide after irradiation and that this does not occur in BL30K cells (Michael et at. [1997] Cancer Res 57:3600-3605). We show that p38 MAPK is activated transiently in both cells after ionising radiation. On the of her hand, although JNK is rapidly activated in both cells, this activation is only transient in the resistant cells, whereas in the sensitive cells the activation is sustained. Addition of exogenous ceramide resulted in only a transient activation of INK in both cells. Interestingly, ERK activity was decreased in BL30A cells after ceramide treatment, whereas no such decrease occurred in the resistant cells. Treatment of BL30A cells with phorbol ester before irradiation, which blocks the increase in ceramide and apoptosis, also prevents the sustained increase in JNK activity. At the same time, ERK activity is increased. Our results suggest that p38 MAPK is not required for apoptosis signalling in response to ionising radiation in Burkitt's lymphoma cells and that sustained activation of JNK is necessary for apoptosis in these cells. These results also support the hypothesis that a balance between JNK and ERK activity determines cell fate after exposure to ceramide or ionising radiation. In addition, our results suggest different signalling pathways from exogenous ceramide and radiation, supporting the concept of different intracellular pools of active ceramide. Drug Dev. Res. 52:534-541, 2001. (C) 2001 Wiley-Liss, Inc.

The supportive care needs of men with prostate cancer (2000)

The diagnosis and subsequent treatment of prostate cancer is followed by a range of significant disease specific and iatrogenic sequelae. However, the supportive care needs of men with prostate cancer are not well described in the literature. The present study assesses the supportive care needs of men with prostate cancer who are members of prostate cancer self-help groups in Queensland, Australia. In all, 206 men aged between 48 and 85 years (mean = 68) completed the Supportive Care Needs Survey (SCNS) (62% response). The SCNS is a validated measure assessing perceived need in the domains of psychological needs, health system and information needs, physical and daily living needs, patient care and support, and sexuality. Items assessing need for access to services and resources were also included. One third of the sample reported a moderate to high need for help for multiple items in the sexuality, psychological and health system and information domains. Younger men reported greater need in the sexuality domain; living in major urban centres was predictive of greater psychological need; being closer to the time of diagnosis was related to greater need for help in the physical and daily living domain; having prostate cancer that is not in remission, having received radiation therapy, and lower levels of education were predictive of greater need for help in patient care and support. Of the total sample, 55% of men had used alternative cancer treatments in the past 12 months, with younger and more educated men more likely to use alternative therapies. Interventions in sexuality, psychological concerns and informational support are priorities for men with prostate cancer. Copyright (C) 2001 John Wiley & Sons, Ltd.