Quantifying movement of multiple threatened species to inform adaptive management of environmental flows.

There is a growing need for water managers to refine and optimise environmental flow strategies (e-flows) to balance water requirements for humans and nature. With increasing demands for freshwater and consequent declines in biodiversity, managers are faced with the problem of how to adaptively manage e-flows for multiple stakeholders and species whose flow requirements may overlap or vary. This study assessed the effectiveness of a regulated e-flow release strategy from a dam, aimed at providing movement opportunities and facilitating reproductive processes for multiple threatened species. Movements of 24 Mary River cod (Maccullochella mariensis), 20 Australian lungfish (Neoceratodus forsteri) and 13 Mary River turtle (Elusor macrurus) were quantified using acoustic telemetry over a three-year period. The influence of regulated e-flow releases, season, river depth, water temperature and rainfall on animal movements was assessed using Generalised linear mixed models (GLMMs). Models showed that hydraulic connectivity provided by both natural flows and regulated e-flow releases facilitated movement of all three species between pool habitats, throughout the year. Mary River turtles made extensive use of regulated e-flow releases when moving between habitats, whereas Mary River cod and Australian lungfish required additional natural rises in river height above the regulated e-flows to trigger movements. Significant movement activity was also recorded for cod and turtles during the dry season (winter and spring), broadly coinciding with breeding periods for these species. The effectiveness of, and potential improvements to, current e-flow strategies to sustain key life-history requirements of these species is discussed. Findings suggest a revised e-flow strategy with relatively minor increases in the magnitude of e-flow releases throughout winter and spring, would be effective in providing movement opportunities and supporting reproductive success for all three species. This study demonstrates that by quantifying movement behaviour in an e-flow context, ecological risk assessment frameworks can then be used to assess and provide for critical life-history requirements of multiple species within the context of a highly regulated system under increasing water use demands.

Dry season habitat use of fishes in an Australian tropical river.

The modification of river flow regimes poses a significant threat to the world's freshwater ecosystems. Northern Australia's freshwater resources, particularly dry season river flows, are being increasingly modified to support human development, potentially threatening aquatic ecosystems and biodiversity, including fish. More information is urgently needed on the ecology of fishes in this region, including their habitat requirements, to support water policy and management to ensure future sustainable development. This study used electrofishing and habitat survey methods to quantify the dry season habitat use of 20 common freshwater fish taxa in the Daly River in Australia's wet-dry tropics. Of twenty measured habitat variables, water depth and velocity were the two most important factors discriminating fish habitat use for the majority of taxa. Four distinct fish habitat guilds were identified, largely classified according to depth, velocity and structural complexity. Ontogenetic shifts in habitat use were also observed in three species. This study highlights the need to maintain dry season river flows that support a diversity of riverine mesohabitats for freshwater fishes. In particular, shallow fast-flowing areas provided critical nursery and refuge habitats for some species, but are vulnerable to water level reductions due to water extraction. By highlighting the importance of a diversity of habitats for fishes, this study assists water managers in future decision making on the ecological risks of water extractions from tropical rivers, and especially the need to maintain dry season low flows to protect the habitats of native fish.

Fish response to the temporal hierarchy of the natural flow regime in the Daly River, northern Australia.

In this study, relationships between flow variation across multiple temporal scales and the distribution and abundance of three fish species, western rainbowfish Melanotaenia australis, sooty grunter Hephaestus fuliginosus and barramundi Lates calcarifer were examined at eight sampling reaches in the Daly River, Northern Territory, Australia. Discharge was highly seasonal during the study period of 2006-2010 with a distinct wet-dry discharge pattern. Significant catchment-wide correlations were identified between species abundance and hydrologic variables across several scales describing the magnitude and variability of flow. A Bayesian hierarchical model which accounted for >80% of variation in abundances for all species and age classes (i.e. juvenile and adult), identified the extent to which the influence of short-term flow variation was dependent upon the historical flow regime. There were distinct ontogenetic differences in these relationships for H. fuliginosus, with variability of recent flows having a negative effect on juveniles which was stronger at locations with higher historical mean daily flow. Lates calcarifer also displayed ontogenetic differences in relationships to flow variation with adults showing a positive association with increase in recent flows and juveniles showing a negative one. The effect of increased magnitude of wet-season flows on M. australis was negative in locations with lower historical mean daily flow but positive in locations with higher historical mean daily flow. The results highlighted how interactions between multiple scales of flow variability influence the abundance of fish species according to their life-history requirements.

Widespread omnivory and low temporal and spatial variation in the diet of fishes in a hydrologically variable northern Australian river.

This article examines the trophic ecology of freshwater fishes (22 species in 15 families) in a wet and dry tropical Australian river of high intra-annual and interannual hydrological variability. Seven major trophic groups were identified by cluster analysis; however, four food items (filamentous algae, chironomid larvae, Trichoptera larvae and Ephemeroptera nymphs) comprised almost half of the average diet of all species. The influence of species, fish size, spatial effects and temporal effects on food use was investigated using redundancy analysis. Size, time and space accounted for little of the perceived variation. Ontogenetic changes in diet were minor and limited to a few large species. Spatial variation in trophic composition of the fish assemblages reflected the effects of the Burdekin Falls and dam, a major geographic barrier, on species distributions. Little spatial variation in diet was detected after accounting for this biogeographical effect. Temporal variations in flow, although marked, had little effect on variations in fish diet composition due to the low temporal diversity of food resources in physically monotonous sand and gravel channels. Species identity accounted for<50% of the observed variation in food choice; omnivory and generalism were pronounced. The aquatic food web of the Burdekin River appears simple, supported largely by autochthonous production (filamentous and benthic microalgae, and to some extent, aquatic macrophytes). Allochthonous food resources appear to be unimportant. The generalist feeding strategies, widespread omnivory and absence of pronounced trophic segregation reported here for Burdekin River fishes may be common to variable and intermittent rivers of subtropical and tropical northern Australia with similar fish communities and may be a general feature of rivers of low habitat diversity and characterized by flow regimes that vary greatly both within and between years.

Rapid photoreflectance spectroscopy for strained silicon metrology.

We present an improved photoreflectance (PR) spectroscopy technique upon the prior art in providing a rapid acquisition method of the PR spectrum in a simultaneous and multiplexed manner. Rapid PR (RPR) application is the on-line monitoring of strained silicon. Shrinkage in the silicon bandgap is measured and converted to strain, using theoretical models. Experimental RPR results are in good correlation with Raman spectroscopy.

Combined research and clinical learning make Rural Summer Studentship Program a successful model.

CONTEXT: Many medical schools would like to provide students with opportunities to learn and perform practical research and to have positive rural learning experiences. Rural physicians often have research ideas, but may lack the skills or assistance to perform the research. PROGRAM DESCRIPTION: The unique Rural Summer Studentship Program (RSSP) at The University of Western Ontario (Western) places students with preceptors in small and mid-sized communities throughout Southwestern Ontario where they have an opportunity to perform rural health research, combined with clinical learning, for 8 weeks in the summer after the first or second year of medical school. Secretarial coordination, research assistant support and senior faculty supervision were provided. OUTCOMES: From 1999-2003 inclusive, 44 students have participated including eight who participated over two summers. Projects were carried out in more than 20 communities with over 30 preceptors. Already, two students have had their research published in peer-reviewed journals and six have presented at major conferences. Participating students indicated an increase in interest in rural and regional medicine and in their knowledge of rural and regional medicine and patient care. They rated the value of RSSP highly as part of their medical education, even compared with other electives/selectives. CONCLUSION: The RSSP model developed at Western provides a highly rated, successful combination of supported medical student research and clinical learning with preceptors in small and mid-sized communities.

Serum p97 levels as an aid to identifying Alzheimer's disease.

Background: The application of formal clinical diagnostic criteria for the identification of Alzheimer's Disease (AD) has improved diagnostic sensitivity. However, there remains a need for non-invasive biological markers and laboratory tests, which can facilitate case identification, and the assessment of treatment response. The p97 protein is a secreted protein specifically expressed by amyloid plaque associated reactive microglia that may have AD diagnostic ability. Methods: A quantitative radioimmunoassay was developed to measure serum p97. This study, under a double blind protocol, evaluated the utility of serum p97 as diagnostic test for AD. All subjects were referred to the UBC Clinic for Alzheimer's Disease and Related Disorders (CADRD) for clinical assessment of dementia. A serum p97 sample was obtained at the time of assessment but diagnosis of disease was determined independently of p97 examination. Results: "Possible" and "probable" AD cases (n = 41) and cognitively normal controls (n = 64) showed a highly significant difference in mean p97 concentration (41 vs. 20 ng/ml, p<0.001). There was some overlap in p97 distributions between AD cases and control subjects. The area under the curve (AUC) for the receiver operator curve (ROC) was 0.812. Conclusions: These results further support the specificity of high serum p97 levels in AD and its potential utility as a biological marker in AD. The reproducible elevation of serum p97 in AD underlines the need to further determine its role as a biological marker and diagnostic adjunct for AD.

Emergency patient transfers from rural hospitals: a regional study.

OBJECTIVE: To clarify case mix, mode of transport and reasons for interfacility transfer from rural emergency departments (EDs) and to make recommendations for improved emergency health care delivery in rural settings. METHODS: This was a multi-centre descriptive study, based in 5 rural Ontario EDs. Over a 1-year period, all ED patients who required transfer to another hospital were studied. Data collection forms were completed prospectively by the most responsible nurse involved in the transfer. Main measurements included patient age, gender, place of residence, circumstances and reason for transfer, primary diagnosis, mode of transport and receiving hospital. RESULTS: Of 53 796 patients who presented to the 5 participating EDs, 98.4% were managed locally and 836 (1.6%) were transferred to referral centres. Most patients (86%) were transferred because they required treatment beyond the scope of the local hospital. The need for orthopedic care, CT and pediatric care accounted for 23.6%, 14.1% and 8.7% of transfers respectively. CONCLUSIONS: These data suggest that rural family physicians may benefit from increased orthopedic and pediatric training and support. The study also identified a need for increased specialist availability in our rural setting. The high number of transfers for CT scans suggests that some rural health regions should consider acquiring a "regional" CT scanner. The development of a regional hospital, with a CT scanner and specialist resources, especially a general surgery on-call system, would reduce the need for transfer outside the region.

Use of complementary/alternative medicine by breast cancer survivors in Ontario: prevalence and perceptions.

PURPOSE: To determine the prevalence of use of complementary/alternative medicine (CAM) by breast cancer survivors in Ontario, Canada, and to compare the characteristics of CAM users and CAM nonusers. PATIENTS AND METHODS: A questionnaire was mailed to a random sample of Ontario women diagnosed with breast cancer in 1994 or 1995. RESULTS: The response rate was 76.3%. Overall, 66.7% of the respondents reported using CAM, most often in an attempt to boost the immune system. CAM practitioners (most commonly chiropractors, herbalists, acupuncturists, traditional Chinese medicine practitioners, and/or naturopathic practitioners) were visited by 39.4% of the respondents. In addition, 62.0% reported use of CAM products (most frequently vitamins/minerals, herbal medicines, green tea, special foods, and essiac). Almost one half of the respondents informed their physicians of their use of CAM. Multiple logistic regression analysis determined that support group attendance was the only factor significantly associated with CAM use. CONCLUSION: CAM use is common among Canadian breast cancer survivors, many of whom are discussing CAM therapy options with their physicians. Knowledge of CAM therapies is necessary for physicians and other health care practitioners to help patients make informed choices. CAM use may play a role in the positive benefits associated with support group attendance.

Breast cancer survivors' perceptions of complementary/alternative medicine (CAM): making the decision to use or not to use.

The study described in this article explored breast cancer survivors' perceptions and experiences as they decided whether to use a variety of complementary/alternative therapies. Six focus groups were conducted composed of women who had been diagnosed with breast cancer. Each 2-hour session was audiotaped and transcribed verbatim. In this article, the process by which the participants made the decision to use or not to use complementary/alternative therapies, including their discovery and investigation of complementary/alternative medicine (CAM) and their experiences using or not using CAM, are described. Barriers to using CAM included cost, access, and time. Family and friends generally supported the decision to use CAM; however, the participants described health care practitioners' reactions as mixed.

Differences in the expression and localization of human melanotransferrin in lepidopteran and dipteran insect cell lines.

The ability of several lepidopteran and dipteran insect cell lines to express human melanotransferrin (p97), a glycosyl phosphatidylinositol (GPI)-anchored, iron-binding sialoglycoprotein, was assessed. Spodoptera frugiperda-derived (Sf9) cell lines, transformed with the p97 gene under control of a baculovirus immediate-early promoter, were able to constitutively express the protein and correctly attach it to the outer cell membrane via a GPI anchor as demonstrated by PI-PLC treatment. In contrast, stable constitutive expression could not be demonstrated with cell lines derived from either Drosophila melanogaster (Kc1 or SL2) or Lymantria dispar (Ld652Y) despite the observation that p97 could be detected in transient expression assays. This may indicate that the long-term expression and accumulation of p97 is inhibitory to Drosophila cells, possibly due to improper localization of the protein and resultant competition for cellular iron. In stably transformed Sf9 cells, p97 was expressed on the cell at a maximal level of 0.18 microg/10(6) cells and was secreted at a maximal rate of 9.03 ng/10(6) cells/h. This level was comparable to the amount expressed with the baculovirus system (0.37 microg/10(6) cells and 31.2 ng/10(6) cells/h) and transformed CHO cells (0.88 microg/10(6) cells and 7.8 ng/10(6) cells/h). Deletion of the GPI cleavage/attachment site resulted in an eightfold increase in the secretion rate of p97, when compared to the intact construct suggesting that the rate-limiting step involves processing of the GPI anchor.

Expression of cell surface GPI-anchored human p97 in baculovirus-infected insect cells.

The baculovirus/insect cell system (Autographa californica multiple nuclear polyhedrosis virus/Spodoptera frugiperda Sf9 cells) was used to express the GPI-anchored human melanoma tumor antigen, melanotransferrin or p97. This system served to study the expression and productivity of recombinant GPI-anchored p97 by insect cells. The Sf9 cells expressed a cell surface GPI-anchored form of p97 as well as a soluble form of p97 that did not appear to be derived from the GPI-anchored form of p97. Both recombinant forms, although Endo H resistant, migrated slightly faster ( approximately 88 kDa) than the native p97 ( approximately 95-97 kDa). The insect GPI-anchored p97 was sensitive to PI-PLC, which exposed a detectable cross-reacting determinant. The Sf9 cell surface p97 expression was similar to that of human melanoma (SK-MEL-28) cells, whereas the Sf9 cell specific secretion rate was 10-fold higher. Also Sf9 cells retained considerably higher levels of p97 within the cell. The Sf9 cell surface expression of p97 varied with time after infection, with the maximum expression, which appeared independent of multiplicities of infection greater than 1, occurring at 48 h. After 48 h, levels of cell surface and secreted p97 fell whereas p97 retained within the cell increased, which possibly reflected the lytic nature of the expression system. The successful expression of GPI-anchored human p97 by the baculovirus/insect cell system not only provides a source of p97 for further research but also is the basis of an alternative method for the commercial production of GPI-anchored proteins.

Increasing GPI-anchored protein harvest concentrations from suspension and porous microcarrier CHO cell cultures.

Chinese hamster ovary (CHO) cells expressing the human melanoma tumour antigen, p97, were used to develop a controlled release process for the production of recombinant glycosyl-phosphatidylinositol (GPI) anchored proteins. The cells were cultured either in suspension or immobilized on porous microcarriers and p97 was selectively cleaved from the cell surface by the bacterial enzyme, phosphatidylinositol-phospholipase C (PI-PLC). The kinetics of p97 cleavage from the cell surface by PI-PLC was shown to be approximated by Michaelis-Menten kinetics. The recovered p97 concentrations were increased by reusing the PI-PLC enzyme solution to harvest multiple batches of cells. A convenient PI-PLC assay was developed to monitor the harvesting process and to determine the stability of PI-PLC under harvesting conditions. Although the Pl-PLC was stable under harvesting conditions, it rapidly adsorbed to the cell surface and was depleted from the reused enzyme solution. In order to maintain PI-PLC activity, it was necessary to add fresh PI-PLC to the reused enzyme solution before harvesting a fresh batch of cells. The maximum p97 concentration that could be obtained from harvesting CHO cells cultured on porous microcarriers was limited by the dilution effects of sample removal, adding fresh PI-PLC and liquid associated with settled microcarriers. A model was developed that adequately predicted the p97 concentration after each harvest and the maximum p97 concentration that could be achieved by this harvesting method. The dilution effects were minimized by harvesting from centrifuged suspension culture cells and the harvested p97 concentration was increased by over sixfold to 0.64 mg/mL.

Preferences for cardiopulmonary resuscitation.

PURPOSE: To examine nurse-patient communication about preferences for cardiopulmonary resuscitation (CPR). DESIGN: Prospective cohort. Sampled were patients and nurses caring for patients enrolled in SUPPORT (1989-91), a multicenter study of seriously-ill hospitalized adults at four U.S. hospitals. METHODS: Information about patient preferences was obtained by interviews with patients and their designated surrogates. For selected patients, nurses were interviewed prospectively about their understanding of patients' preferences and whether they discussed these preferences with their patients. Nurse demographic information was obtained by questionnaire. Additional patient data were obtained by interview and chart review. Logistic regression was used to identify independent correlates of nurse-patient communication and nurses' understanding of patients' preferences. FINDINGS: For 1,763 study patients, 1,427 nurse interviews (response rate 81%) were obtained. The median age of interviewed nurses was 29 years; 96% were women, 68% had a bachelor's or master's degree, and 62% had worked for 5 years or more as a nurse. Nurses reported discussions about CPR with 13% of their patients, and these discussions were more likely if the nurse thought the patient did not want CPR (adjusted odds ratio [AOR] 2.68; 95% CI 1.84 to 3.90), if the nurse had spent more time with the patient (AOR 1.05; 95% CI 1.02 to 1.08) per 5 additional days, if the patient had metastatic cancer (AOR 3.56; 95% CI 1.86 to 6.78), or if the patient was in an intensive care unit at the time of study entry (AOR 2.08; 95% CI 1.26 to 3.42). Diagnosis and study site were also associated with nurses' reports of discussions with patients. Of 551 patients with available data, 58% (n = 317) wanted CPR and 30% (n = 164) did not. Nurses understood patients' CPR preferences correctly for 74% of the patients. Nurses were more likely to understand patients' preferences to forego CPR if the patient was 75 years of age or older (AOR 6.6; 95% CI 2.0 to 22.0) or if the nurse and patient had discussed the patient's preferences (AOR 25.3; 95% CI 6.5 to 98.6) or if the patient had cancer (AOR 10.9; 95% CI 2.3 to 50.1). Nurses' understanding of patients' preferences for CPR was no better than that of physicians or patients' surrogate decision-makers. CONCLUSIONS: In this sample of seriously ill hospitalized adults, discussions between patients and nurses about CPR were infrequent. Nurses' understanding of patients' preferences for care was similar to that of physicians and patients' surrogate decision-makers. Educational interventions should focus on increasing the frequency of nurse-patient discussions about end-of-life care and improving nurses' understanding of patients' preferences for care.

Serum levels of the iron binding protein p97 are elevated in Alzheimer's disease.

Alzheimer's disease is a progressive and incurable disease whose prevalence increases dramatically with age. A biochemical marker for monitoring the onset and progression of the disease would be a valuable tool for disease management. In addition, such a marker might be used as an end point in clinical intervention protocols. Here we provide evidence that the soluble form of the iron binding protein p97 is found in elevated amounts in the serum of Alzheimer's patients compared with healthy controls. This biochemical marker has the potential for identifying subjects afflicted with the disease and possibly for monitoring the onset and longitudinal progression of the disease.

Pumping iron in the '90s.

The role o f iron in cell division, cell death and human disease has recently gained increased attention. The best studied process for iron uptake into mammalian cells involves traps ferrin and its receptor. This review discusses evidence supporting the existence of other routes by which iron can enter mammalian cells. Specifically, iron uptake by the cell-surface GPI-linked traps ferrin homologue, melanotransferrin or p97, is described and possible functions of this traps ferrin-independent pathway are proposed.

Participation of nurses in decision making for seriously ill adults.

The purpose of this study is to describe the involvement of nurses in the decision-making process of seriously ill hospitalized adults. Nurses (696) completed interviews with 1,427 patients. Patient, surrogate, and physician interviews were also completed. Patients and surrogates perceive the nurse as more influential in decision making than does the nurse or physician. Many nurses reported having no (31%) or little (36%) knowledge of their patients' preferences, and 53% of the nurses did not advocate for their patients' preferences. Only 50% of the nurses reported educating their patients about the treatment plan chosen or discussing treatment options with their patients, and few (17%) discuss prognosis. This study indicates nurses are not actively involved in the decision-making process of their patients, especially older or more experienced nurses and those working in intensive care units.

Coincident expression and distribution of melanotransferrin and transferrin receptor in human brain capillary endothelium.

One method of iron transport across the blood brain barrier (BBB) involves the transferrin receptor (TR), which is localized to the specialized brain capillary endothelium. The melanotransferrin (MTf) molecule, also called p97, has been widely described as a melanoma specific molecule, however, its expression in brain tissues has not been addressed. MTf has a high level of sequence homology to transferrin (Tf) and lactoferrin, but is unusual because it predominantly occurs as a membrane bound, glycosylphosphatidylinositol (GPI) anchored molecule, but can also occur as a soluble form. We have recently demonstrated that GPI-anchored MTf provides a novel route for cellular iron uptake which is independent of Tf and its receptor. Here we consider whether MTf may have a role in the transport of iron across the BBB. The distributions of MTf, Tf and the TR were studied immunohistochemically in human brain tissues. The distributions of MTf and TR were remarkably similar, and quite different from that of Tf. In all brain tissues examined, MTf and the TR were highly localized to capillary endothelium, while Tf itself was mainly localized to glial cells. These data suggest that MTf may play a role in iron transport within the human brain.