Quantifying potential nitrogen removal by denitrification in stream sediments at a regional scale

Potential denitrification rates were measured using the acetylene block method, in sediments collected from streams in the sub-tropical, south-east Queensland region of Australia. Our aim was to estimate how much nitrogen could be removed from lotic systems by denitrification at the regional scale. Denitrification measured at 65 sites in August and September from a catchment of 22700 km(2) was extrapolated to all streams and rivers in the region based on the sediment area available for denitrification. Denitrification rates ranged between 4 and 950 mumol N m(-2) h(-1), with most sites having rates below 150 mumol N m(-2) h(-1). Based on these results, the current study estimates that a total of 305 t of nitrogen could be denitrified per year from all streams and rivers in the region, representing 6% of the total annual nitrogen load from surrounding land use. During baseflow conditions, when nitrogen loads to streams are low, the proportion of nitrogen removed through denitrification would be substantially higher, in some cases removing 100% of the nitrogen load. It is proposed that denitrification is an important process maintaining low concentrations of dissolved inorganic nitrogen under baseflow conditions and is therefore likely to enhance nitrogen limitation of primary production in this region.

Subordinate-manager gender combination and perceived leadership style influence on emotions, self-esteem and organizational commitment

A theoretical model was developed to investigate the relationships among subordinate-manager gender combinations, perceived leadership style, experienced frustration and optimism, organization-based self-esteem and organizational commitment. The model was tested within the context of a probabilistic structural model, a discrete Bayesian network, using cross-sectional data from a global pharmaceutical company. The Bayesian network allowed forward inference to assess the relative influence of gender combination and leadership style on the emotions, self-esteem and commitment consequence variables. Further, diagnostics from backward inference were used to assess the relative influence of variables antecedent to organizational commitment. The results showed that gender combination was independent of leadership style and had a direct impact on subordinates' levels of frustration and optimism. Female manager-female subordinate had the largest probability of optimism, while male manager teamed with a male subordinate had the largest probability of frustration. Furthermore, having a female manager teamed up with a male subordinate resulted in the lowest possibility of frustration. However, the findings show that the gender issue is not simply female managers versus male managers, but is concerned with the interaction of the subordinate-manager gender combination and leadership style in a nonlinear manner. (C) 2003 Elsevier Inc. All rights reserved.

Adverse Health Effects of Chronic Exposure to Low-Level Cadmium in Foodstuffs and Cigarette Smoke

Cadmium is a cumulative nephrotoxicant that is absorbed into the body from dietary sources and cigarette smoking. The levels of Cd in organs such as liver and kidney cortex increase with age because of the lack of an active biochemical process for its elimination coupled with renal reabsorption. Recent research has provided evidence linking Cd-related kidney dysfunction and decreases in bone mineral density in nonoccupationally exposed populations who showed no signs of nutritional deficiency. This challenges the previous view that the concurrent kidney and bone damage seen in Japanese itai-itai disease patients was the result of Cd toxicity in combination with nutritional deficiencies, notably, of zinc and calcium. Further, such Cd-linked bone and kidney toxicities were observed in people whose dietary Cd intakes were well within the provisional tolerable weekly intake (PTWI) set by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives of 1 mug/kg body weight/day or 70 mug/day. This evidence points to the much-needed revision of the current PTWI for Cd. Also, evidence for the carcinogenic risk of chronic Cd exposure is accumulating and Cd effects on reproductive outcomes have begun to emerge.

Medication management reviews for people from the former Yugoslavia now resident in Australia

Aim: The objective of this prospective study was to conduct medication management reviews (MMR) in people from a non-English speaking background (NESB) (Bosnian/Serbian/ Croatian, from former Yugoslavia, currently residing in Australia) in their native language in order to identify medication-related problems (needs analysis) and implement appropriate therapeutic interventions, in collaboration with their general practitioners (GPs). Methods: Twenty-five participants entered the study. Each was interviewed and medication-related issues were identified by the health care team. Results: Various interventions (over 150 for the whole group, an average of 6 per participant), based on actual and potentia medication-related problems, were designed to improve the use of medicines. The MMRs introduced effective changes into the participants' health care. Psychological (e.g., feeling depressed) and sociological factors (e.g., costs of medicines, not understanding labels written in English) were identified having significant impacts on medication management. Conclusions: These data confirmed there are avoidable medication-related problems in people from a NESB. GPs and pharmacists working in health care teams with a trained interpreter could greatly improve medication use through regular review and a team approach to problem identification and solving.

A review of three years experience using email and videoconferencing for the delivery of post-acute burns care to children in Queensland

A virtual outpatient service has been established in Queensland for the delivery of post-acute burns care to children living in rural and remote areas of the state. The integration of telepaediatrics as a routine service has reduced the need for patient travel to the specialist burns unit situated in Brisbane. We have conducted 293 patient consultations over a period of 3 years. A retrospective review of our experience has shown that post-acute burns care can be delivered using videoconferencing, email and the telephone. Telepaediatric bums services have been valuable in two key areas. The first area involves a programme of routine specialist clinics via videoconference. The second area relates to ad-hoc patient consultations for collaborative management during acute presentations and at times of urgent clinical need. The families of patients have expressed a high degree of satisfaction with the service. Telepaediatric services have helped improve access to specialist services for people living in rural and remote communities throughout Queensland. (C) 2003 Elsevier Ltd and ISBI. All rights reserved.

Acute cadmium chloride administration induces hepatic and renal cytochrome P450 2A5 in the mouse

Modulation of the cytochrome P450 (CYP) monooxygenase system by cadmium was investigated in male, adult DBA/2J mice treated with a single dose (16 Amol/kg body weight, i.p.) of cadmium chloride (CdCl2) at various time points. The total CYP content of kidney microsomes started to decrease 4 hours earlier than in the liver (P < 0.05), with maximal decreases at 24 hours of 56% and 85% in the liver and kidney, respectively. In contrast, both hepatic and renal coumarin 7-hydroxylase (COH) activity (indicative of CYP2A5 activity) relative to total CYP content started to progressively increase at 8 hours, with renal activity 61 times higher than the hepatic activity. Maximum increases were observed, 15-fold in the liver and 64-fold in the kidney after 24 hours. Liver and kidney CYP2A5 mRNA levels increased maximally 12 and 4 hours after treatment, respectively and decreased to almost half 6 hours later. In contrast, kidney and liver CYP2A5 protein levels increased maximally at 18 and 24 hours. This study demonstrates that hepatic and renal CYP2A5 is upregulated by cadmium with a faster response in the kidney than in the liver. This observation is concordant with the fact that kidney is the target organ for cadmium toxicity. The observed increase in the mRNA but not in protein levels after maximal induction suggests involvement of post-transcriptional mechanisms in the regulation of CYP2A5 expression by cadmium.

Perceptions of organisational subculture and their significance for organisational commitment

This paper investigates the relationship between perceptions of organisational culture, organisational subculture, leadership style, and commitment. The impact of culture and leadership style on commitment has been previously noted, but there is a lack of detail regarding how different types of culture and leadership styles relate to commitment. The paper particularly addresses the notion of organisational subcultures and how the perception of those cultures relates to commitment, subculture being a neglected variable in the commitment literature. These issues were addressed in a survey of 258 nurses drawn from a range of hospital settings and wards within the Sydney metropolitan region. Results indicate that perceived organisational subculture has a strong relationship with commitment. Furthermore, the results identify the relative strength of specific types of leadership style and specific types of subculture with commitment. Both innovative and supportive subcultures have a clear positive relationship, while bureaucratic subcultures have a negative relationship. In terms of leadership style, a consideration style had a stronger relationship with commitment than a structuring style. Regression analysis was used to investigate the possible role of subculture as a mediator for the influence of leadership on commitment. Both direct and indirect effects of leadership on commitment were found. Implications for practice and for further research are discussed.

Telemedicine for rural and remote child and youth mental health services

The E-Child and Youth Mental Health Service was designed to provide children and adolescents in Queensland with access to specialist mental health consultations using telemedicine. A project officer provided a single point of contact for referral management and clinic coordination, thereby reducing barriers of access to the service. Over a six-month period from November 2004, 42 point-to-point videoconferences were conducted to nine sites in Queensland. Three multipoint conferences were also conducted. Eleven videoconferences (24%) were arranged for administrative purposes, and 34 (76%) were conducted for the delivery of clinical services (30 patients). The referral and consultation activity suggests an improvement in the capacity of rural and remote mental health service providers to deliver specialist services for children and adolescents.

Environmental contamination of arsenic and its toxicological impact on humans

Inorganic arsenic compounds are known carcinogens. The human epidemiologic evidence of arsenic-induced skin, lung, and bladder cancers is strong. However, the evidence of arsenic carcinogenicity in animals is very limited. Lack of a suitable animal model until recent years has inhibited studies of the mechanism of arsenic carcinogenesis. The toxicity and bioavailability of arsenic depend on its solubility and chemical forms. Therefore, it is critical to be able to measure arsenic speciation accurately and reliably. However, speciation of arsenic in more complex matrices remains a real challenge. There are tens of millions of people who are being exposed to excessive levels of arsenic in the drinking water alone. The source of contamination is mainly of natural origin and the mass poisoning is occurring worldwide, particularly in developing countries. Chronic arsenicosis resulting in cancer and non-cancer diseases will impact significantly on the public health systems in their respective countries. Effective watershed management and remediation technologies in addition to medical treatment are urgently needed in order to avoid what has been regarded as the largest calamity of chemical poisoning in the world.