Extreme eutrophication and salinisation in the Coorong estuarine-lagoon ecosystem of Australia's largest river basin (Murray-Darling).

Estuaries in rainfall poor regions are highly susceptible to climatic and hydrological changes. The Coorong, a Ramsar-listed estuarine-coastal lagoon at the end of the Murray-Darling Basin (Australia), has experienced declining ecological health over recent decades. Twenty years of environmental data were analysed to assess patterns and drivers of water quality changes. Large areas of the Coorong are now persistently hyper-saline (salinity >80 psu) and hypereutrophic (total nitrogen, TN > 4 mg L-1, total phosphorus, TP > 0.2 mg L-1, chlorophyll a > 50 µg L-1) which coincided with reduced flushing due to diminished freshwater inflows and increasing evapo-concentration. Sediment quality also was related to flushing, with higher concentrations of organic carbon, TN, TP and sulfides as salinity increased. While total nutrient levels are very high, dissolved inorganic nutrients are generally low. Increased lagoonal flushing would be beneficial to reduce the hypersalinisation and hypereutrophication and improve ecosystem health.

Uncovering hidden heterogeneity: Geo-statistical models illuminate the fine scale effects of boating infrastructure on sediment characteristics and contaminants.

Infrastructure associated with coastal communities is likely to not only directly displace natural systems, but also leave environmental footprints' that stretch over multiple scales. Some coastal infrastructure will, there- fore, generate a hidden layer of habitat heterogeneity in sediment systems that is not immediately observable in classical impact assessment frameworks. We examine the hidden heterogeneity associated with one of the most ubiquitous coastal modifications; dense swing moorings fields. Using a model based geo-statistical framework we highlight the variation in sedimentology throughout mooring fields and reference locations. Moorings were correlated with patches of sediment with larger particle sizes, and associated metal(loid) concentrations in these patches were depressed. Our work highlights two important ideas i) mooring fields create a mosaic of habitat in which contamination decreases and grain sizes increase close to moorings, and ii) model- based frameworks provide an information rich, easy-to-interpret way to communicate complex analyses to stakeholders.

Metal-contaminated resuspended sediment particles are a minor metal-uptake route for the Sydney rock oyster (Saccostrea glomerata)--A mesocosm study, Sydney Harbour estuary, Australia.

Resuspension of surficial sediments is considered a key process influencing bioaccumulation of metals in filter-feeders in the contaminated Sydney Harbour estuary (Australia). However, previous investigations were unable to establish a significant relationship between metals in sediments or suspended particulate matter (SPM) and oyster tissue concentrations. This study used a 60-d laboratory mesocosm experiment to expose Sydney rock oysters, Saccostrea glomerata, to a natural range of SPM concentrations with different SPM-metal concentrations. Dissolved metal concentrations were low and the availability of algae provided as food was constant for all treatments. Tissue metal concentrations of Cu, Pb and Zn increased significantly, however, no relationship was determined between tissue metal concentrations in the oyster and either SPM or SPM-metal concentrations. The results indicated that exposure to resuspended contaminated sediment particles contributed little to the observed metal uptake. Dissolved or algae food sources appear to be more important for metal accumulation in these oysters.

Dietary ingestion of fine sediments and microalgae represent the dominant route of exposure and metal accumulation for Sydney rock oyster (Saccostrea glomerata): A biokinetic model for zinc.

Past studies disagree on the extent to which dissolved or dietary uptake contribute to metal bioaccumulation in the filter-feeding Sydney rock oyster (Saccostrea glomerata) in urbanized estuaries. Although most data support the assumption that fine sediments are a major route of metal uptake in these bivalves, some studies based in the Sydney estuary, Australia, have indicated a poor correlation. In the present study, seawater, sediment and microalgae were radiolabelled with (65)Zn tracer and exposed to S. glomerata to assess the influence of dissolved and dietary sources to Zn bioaccumulation. Oysters in the dissolved-phase uptake experiment (5, 25 and 50 µg L(-1) (65)Zn for 4 d followed by 21 days of depuration) readily accumulated (65)Zn for all three concentrations with an uptake rate constant of 0.160±0.006 L dry weight g(-1) d(-1). Oysters in the dietary assimilation experiment (1h pulse-feed of either (65)Zn-radiolabelled suspended fine-fraction (<63 µm) sediment or the microalgae Tetraselmis sp.) accumulated (65)Zn, with assimilation efficiencies of 59 and 67% for fine sediment and microalgae, respectively. The efflux rates were low for the three experiments (0.1-0.5% d(-1)). A bioaccumulation kinetic model predicts that uptake of Zn will occur predominantly through the dietary ingestion of contaminated fine sediment particles and microalgae within the water column, with considerably greater metal bioaccumulation predicted if oysters ingested microalgae preferentially to sediments. However, the model predicts that for dissolved Zn concentrations greater than 40 µg L(-1), as observed during precipitation events, the uptake of the dissolved phase may contribute ≥50% to accumulation. Overall, the results of the present study suggest that all three sources may be important exposure routes to S. glomerata under different environmental conditions, but contributions from dietary exposure will often dominate.

Gonadotropin stimulation using P.G. 600® on reproductive success of non-lactating anestrous ewes.

The effect of stimulation with a gonadotropin preparation with combined follicle stimulating and luteininzing hormone like activity on reproductive success in anestrous ewes was evaluated. In Experiment 1, ewes of mixed breeding were treated with CIDR inserts (0.3g progesterone) for 5 days and were assigned randomly to receive either gonadotropin stimulation (3mL i.m. injection of P.G. 600®, 240IU eCG and 120IU hCG) at CIDR removal or no further treatment. Intact raddled rams were joined at insert removal for 30-35 days, and ewes were observed for indications of estrus after 4 days of ram exposure. Pregnancy diagnosis was conducted via transrectal ultrasonography at the time of ram removal and again 20-25 days. The second experiment was similar to Experiment 1, except treated ewes received the gonadotropin 1 day prior to insert removal. In Experiment 1, incidence of estrus was greater for treated ewes (P=0.01), and prolificacy tended to be greater in treated ewes (P=0.06). In Experiment 2, treated ewes had greater conception rates (P=0.01), pregnancy rates to first service (P=0.0007), and tended to have greater overall pregnancy rates than control ewes (P=0.07). A greater percentage of ewes lambed in the gonadotropin treated ewes than in ewes in the control group (P<0.0001), and overall lambing rates in treated ewes were greater than non-treated controls (P<0.0001). In conclusion, gonadotropin treatment 1 day prior to CIDR removal increased reproductive success in progesterone-treated anestrous ewes.

Long-term open-label study of tanezumab for moderate to severe osteoarthritic knee pain.

OBJECTIVE: This study was designed to evaluate the long-term safety and effectiveness of repeated doses of the humanized anti-nerve growth factor antibody, tanezumab, during open-label treatment of patients with OA knee pain. DESIGN: The current study (clinicaltrials.gov identifier: NCT00399490) was a multicenter, phase II, open-label, multiple-dose extension of an earlier randomized clinical trial. All patients (N=281) received infusions of tanezumab 50µg/kg on Days 1 and 56 with subsequent doses administered at 8-week intervals (up to a total of eight infusions). The primary endpoint of this study was safety. Effectiveness evaluations included overall knee pain, Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index subscales, and subject global assessment (SGA) of response to therapy on 0-100 point visual analog scales. RESULTS: Repeated administration of tanezumab resulted in a low incidence of treatment-related adverse events (AEs; 7.5%). The rate of serious AEs was also low (2.8%) with none considered treatment-related. Few AEs of abnormal peripheral sensation were reported; hypoesthesia was reported by nine patients (3.2%), paresthesia by seven patients (2.5%), and hyperesthesia, peripheral neuropathy, and sensory disturbance were each reported by one patient (0.4% for each). Most AEs of abnormal peripheral sensation were rated as mild (95%) and the majority (65%) resolved before study completion. At Week 8, overall knee pain and SGA improved from baseline by a mean (± standard error) of -12.8 (±1.78) and 8.0 (±1.66), respectively. Similar improvements occurred for WOMAC subscales. CONCLUSIONS: Repeated injections of tanezumab in patients with moderate to severe knee OA provide continued pain relief and improved function with a low incidence of side effects. Additional studies to define the efficacy and duration of pain reduction and to provide a more complete assessment of long-term safety are warranted.

Toxicity of metals to the bivalve Tellina deltoidalis and relationships between metal bioaccumulation and metal partitioning between seawater and marine sediments.

The Australian benthic bivalve Tellina deltoidalis tolerates a wide range of sediment and water conditions, is easy to handle in the laboratory, and is a useful species for undertaking whole-sediment toxicity tests. The sensitivity of T. deltoidalis to metals was investigated in 10-day metal-spiked sediment exposures for Cd, Cu, Ni, Pb, and Zn and in water-only exposures for Cu and Zn. The survival of T. deltoidalis in 10-day exposures to metal-spiked sediments was 88-100% for Cd, Ni, Pb, and Zn concentrations of 75, 420, 1,000, and 4,000 mg/kg, respectively. The 4-day LC(50)s for dissolved Cu and Zn were 0.18 and 13 mg/L, respectively. The 8-day LC(50) for Cu was 31 (24-34) microg/L. Cu and Zn concentrations in the tissues of T. deltoidalis increase linearly with increasing dissolved exposure concentration. In the Cu-spiked sediment and water exposures, the survival was negatively correlated with the Cu concentration in both the overlying water and in the tissues of T. deltoidalis. In contrast, particulate Cu concentrations were found to be a poor predictor of Cu bioaccumulation and toxicity for Cu-spiked sediments.

Effect of nutrition on toxicity of contaminants to the epibenthic amphipod Melita plumulosa.

The amphipod Melita plumulosa is commonly used to assess the toxicity of contaminated sediments. Seven-day-old M. plumulosa are <1 mm in size, and during 10-day tests in sandy sediments with low nutritional value, starvation can cause >50% mortality. In sediment toxicity tests, therefore, it can be difficult to determine if toxicity is due to contaminants or starvation, particularly in contaminated sandy sediments. This study investigated the influence of amphipod age and food addition on amphipod survival in toxicity tests. The 4-day LC(50) increased linearly from 120 to 470 microg/L when M. plumulosa age at the beginning of the test increased from 5 to 30 days. The addition of food as algae or fish food did not significantly affect the sensitivity of 11-day-old M. plumulosa (11-d Mp) to dissolved copper over 4 days in water-only tests. The survival of 11-d Mp in water-only tests over 10 days was poor without feeding, but when fed fish food, the 10-day LC(50) was 76 +/- 15 microg/L. In sediment tests, feeding 0.063 mg fish food/amphipod on days 3 and 7 of 10-day tests consistently resulted in greater than 80% survival of 11-d Mp for a range of clean, sandy sediments, which had low amphipod survival without added food. Algae were not always suitable as a food source, as their growth can be stimulated by nutrients released from sediment and was inhibited by contaminants. The toxicity of most contaminated sediments was not ameliorated by the addition of food, suggesting that food addition was suitable for inclusion in routine testing protocols for this amphipod.

An assessment of five Australian polychaetes and bivalves for use in whole-sediment toxicity tests: toxicity and accumulation of copper and zinc from water and sediment.

The suitability of two polychaete worms, Australonereis ehlersi and Nephtys australiensis, and three bivalves, Mysella anomala, Tellina deltoidalis, and Soletellina alba, were assessed for their potential use in whole-sediment toxicity tests. All species except A. ehlersi, which could not be tested because of poor survival in water-only tests, survived in salinities ranging from 18 per thousand to 34 per thousand during the 96-hour exposure period. No mortality was observed in any of the species exposed to sediment compositions ranging from 100% silt to 100% sand for 10 days, thus demonstrating the high tolerance of the five species to a wide range of sediment types. All species showed decreased survival after exposure to highly sulfidic sediments in 10-day whole-sediment tests. In 96-hour water-only tests, survival decreased, and copper accumulation in body tissues increased with exposure to increasing copper concentration for all species except A. ehlersi, which again could not be tested because of its poor survival in the absence of sediment. S. alba and T. deltoidalis were the most sensitive species to aqueous copper (LC50s of 120 and 150 microg Cu/L, respectively). All species tested were relatively insensitive to dissolved zinc up to concentrations of approximately 1,000 microg/L. In addition and with the exception of N. australiensis, all species accumulated significant levels of zinc in their body tissues. Whole-sediment tests were conducted over a 10-day period with copper-spiked (1,300 microg/g) and zinc-spiked (4,000 microg/g) sediments equilibrated for sufficient time to ensure that pore water metal concentrations were well below concentrations shown to have any effect on organisms in water-only tests. Survival was decreased in the bivalves T. deltoidalis and S. alba after exposure to copper-spiked sediments, and all species-except T. deltoidalis, in which 100% mortality was observed-accumulated copper in their tissues. Exposure to zinc-spiked sediments significantly decreased the survival of only one species, T. deltoidalis. Both polychaetes appeared to regulate concentrations of zinc in their body tissues with no significant uptake of zinc occurring from the sediment phase. Of the five species assessed in this study, T. deltoidalis was found to be the most sensitive to copper- and zinc-contaminated sediments, and based on commonly used selection criteria (ASTM 2002a, ASTM 2002b, ASTM 2002c) is recommended for development as test species in whole-sediment toxicity tests.

A rapid screening method for acid-volatile sulfide in sediments.

A new, direct method for the determination of acid-volatile sulfide (AVS) in sediments is presented. The method utilizes the direct reaction of Clines reagent with small amounts of sediment followed by colorimetric determination of AVS and offers fast analysis times without the need for specialized glassware or equipment. A comparison between AVS measured by this method and that measured by a purge-and-trap AVS method shows a linear relationship (r = 0.986, p < 0.001), although the method underestimates the AVS concentration measured by the purge-and-trap method. Sample throughput by the direct AVS method is more than 10 times that of purge-and-trap methods. The applicability of the direct AVS method to the rapid screening of AVS concentrations in sediments and for evaluating sediment quality with respect to metal contamination is demonstrated.

The potential to identify South Asians using a computerised algorithm to classify names.

Ethnic studies are limited by the lack of information on ethnic origin in data sources. This paper examines a computerised approach to identify South Asians by names. Computerised analysis of names is not an ideal solution, but it helps to solve the methodological difficulty of identifying South Asians, particularly in historical administrative datasets where self-assessed ethnicity is not possible and visual inspection is too time consuming and prone to errors. This approach, though useful, is limited to groups easily distinguishable by name and the collection of information on ethnicity should remain the aim in the long-term.

Effect of moderate alcohol consumption on hypertriglyceridemia: a study in the fasting state.

BACKGROUND: Patients with hypertriglyceridemia (HTG) are generally advised to avoid alcohol, even though moderate alcohol consumption is cardioprotective. Alcohol increases plasma triglyceride concentration transiently in normolipidemic subjects, but whether alcohol consumption per se increases triglyceride concentrations in patients with HTG is unclear. OBJECTIVE: To assess whether baseline fasting triglyceride concentration determines plasma triglyceride concentration after acute oral alcohol intake. METHODS: Twelve persons with fasting triglyceride concentrations of 2.3 to 8.5 mmol/L (200-750 mg/dL) and 12 persons as a non-HTG group were enrolled. Obesity, current smoking, and history of hypertension, diabetes, or excessive alcohol use were exclusionary. Fasted subjects consumed 38 mL of ethanol in water (equivalent, 2 alcoholic drinks); blood samples were collected at baseline and at intervals thereafter for 10 hours. No less than 1 week later, the subjects consumed water alone in a control test. RESULTS: Mean triglyceride values were 4.04+/-0.41 mmol/L (358+/-36.9 mg/dL) and 1.00+/-0.11 mmol/L (89+/-10.2 mg/dL) for the HTG and non-HTG groups, respectively. Despite similar changes with alcohol feeding in plasma ethanol, nonesterified fatty acid, and acetate concentrations, the groups differed in triglyceride response. At 6 hours (peak) compared with baseline, triglyceride concentration increased only 3% in the HTG group but 53% in the non-HTG group. The former change was not significantly different from the effect with water alone (-9.2% from baseline; P = .43), whereas the latter was (-8.0%; P = .003). CONCLUSIONS: Acute alcohol intake alone is not an important determinant of plasma triglyceride concentration in individuals with HTG. Other factors, such as the contemporaneous consumption of fat and alcohol, known to increase triglyceride concentrations synergistically in non-HTG individuals, may be more important.

The Drosophila Medea gene is required downstream of dpp and encodes a functional homolog of human Smad4.

The Transforming Growth Factor-beta superfamily member decapentaplegic (dpp) acts as an extracellular morphogen to pattern the embryonic ectoderm of the Drosophila embryo. To identify components of the dpp signaling pathway, we screened for mutations that act as dominant maternal enhancers of a weak allele of the dpp target gene zerknLllt. In this screen, we recovered new alleles of the Mothers against dpp (Mad) and Medea genes. Phenotypic analysis of the new Medea mutations indicates that Medea, like Mad, is required for both embryonic and imaginal disc patterning. Genetic analysis suggests that Medea may have two independently mutable functions in patterning the embryonic ectoderm. Complete elimination of maternal and zygotic Medea activity in the early embryo results in a ventralized phenotype identical to that of null dpp mutants, indicating that Medea is required for all dpp-dependent signaling in embryonic dorsal-ventral patterning. Injection of mRNAs encoding DPP or a constitutively activated form of the DPP receptor, Thick veins, into embryos lacking all Medea activity failed to induce formation of any dorsal cell fates, demonstrating that Medea acts downstream of the thick veins receptor. We cloned Medea and found that it encodes a protein with striking sequence similarity to human SMAD4. Moreover, injection of human SMAD4 mRNA into embryos lacking all Medea activity conferred phenotypic rescue of the dorsal-ventral pattern, demonstrating conservation of function between the two gene products.

Sample storage artifacts affecting the measurement of dissolved copper in sulfidic waters.

Sample preservation and storage procedures (acidification with HNO(3) and storage in plastic bottles) normally employed prior to the determination of dissolved Cu in sulfidic waters were compared with sample preservation involving the initial oxidation of sulfide with H(2)O(2) or S(2)O(5)(2-) followed by acidification. Acidification alone was demonstrated to be inadequate and resulted in a significant underestimation of dissolved Cu (losses ranging from 50% to >90%). Similar losses were observed in both polyethylene and Teflon storage bottles. Experiments suggest that losses of copper occur following sample acidification owing to the formation of stable copper sulfide phases which adsorb onto container surfaces. It is therefore recommended that an oxidative pretreatment step is carried out prior to the acidification of porewaters collected for metal analysis. The results of this study suggest that much of the previous data reporting dissolved Cu concentrations in sulfidic waters and porewaters may be in error.

Thigh pain and total hip arthroplasty: scintigraphy with 2.5-year followup.

From January 1988 to May 1990, 60 patients underwent 68 total hip arthroplasties at the Eisenhower Army Medical Center. The authors excluded 11 patients (11 hips) in whom infection developed, who were lost to followup, or who had incomplete records, leaving 49 patients (57 hips) as the study population. The 35 uncemented and 22 cemented femoral stems were evaluated with technetium bone scans at 1 week, 6 months, 1 year, and 2.5 years after surgery. Patients with uncemented femoral stems had markedly more thigh pain and more radiopharmaceutical uptake around the stem tip at 2.5 years followup than did patients with cemented femoral stems. In addition, patients with thigh pain had more uptake around the stem tip and a higher incidence of bone hypertrophy around the stem tip than did those without thigh pain, suggesting stress transfer as a cause of thigh pain.

Survival estimates for patients with abnormal swallowing studies.

OBJECTIVE: To better understand the life expectancy of patients who have an abnormal videofluoroscopic swallowing study. DESIGN: Retrospective cohort study. The common starting point was the time of the severely abnormal swallowing study. Hospital charts were reviewed for clinical variables of potential prognostic significance by reviewers blinded to the outcome of interest, survival time. SETTING: A university-affiliated, community teaching hospital. PATIENTS: One hundred forty-nine hospitalized patients who were deemed nonoral feeders based on their swallowing study. Patients excluded were those with head, neck, or esophageal cancer, or those undergoing a thoracotomy procedure. MEASUREMENTS AND MAIN RESULTS: Clinical and demographic variables and time until death or censoring were measured. Overall 1-year mortality was 62%. Multivariable Cox proportional hazards analyses identified four variables that independently predicted death: advanced age, reduced serum albumin concentration, disorientation to person, and higher Charlson comorbidity score. Eighty patients (54%) subsequently underwent placement of a percutaneous endoscopic gastrostomy (PEG) tube after their swallowing study. CONCLUSIONS: Mortality is high in patients with severely abnormal swallowing studies. Common clinical variables can be used to identify groups of patients with particularly poor prognoses. This information may help guide discussions regarding possible PEG placement.

Identification of a low specificity, oxygen, heme, and growth phase regulated DNA binding activity in Saccharomyces cerevisiae.

Cytochrome c oxidase from Saccharomyces cerevisiae is subject to intricate control at the level of transcription of the various genes encoding its subunits. Expression of the subunit VI encoding gene, COX6, is glucose repressed, growth phase induced, and dependent on oxygen and heme availability. An upstream activation region for COX6, UAS6, was found to contain a glucose responsive region, a heme dependent region (HDS1), and a binding site for the transcription factor, BAF1. BAF1 was the only factor observed to form a protein complex with UAS6 in vitro. However, we found that binding of BAF1 was unaffected by oxygen or heme regulation. In the present communication, we have identified a DNA binding activity that was growth phase induced and dependent on oxygen and heme availability. This highly regulated activity was detected by its discrete binding to the heme responsive site, HDS1, in UAS6. Nonetheless, it appears to have weak DNA binding specificity.

Oxygen regulation of the cytochrome c oxidase subunit VI gene, COX6, in Saccharomyces cerevisiae.

Cytochrome c oxidase (CcO) in Saccharomyces cerevisiae is subject to intricate physiological control. Growth phase, carbon source, and oxygen level are three well recognized modulators of CcO expression. We focused on the subunit VI encoding gene, COX6, and detected unexpectedly complex oxygen regulation. We found that COX6 transcription possessed a critical threshold oxygen regulation between 0 and 2%. COX6 transcription was superinduced by elevated oxygen level up to 45%; however, superinduction was lost at 60% oxygen and above. The COX6 upstream activation region, UAS6, contains both glucose and heme responsive regions, and COX6 oxygen regulation was transduced through UAS6 by heme, as has been described for other oxygen regulated genes in yeast. We found that binding of the UAS6-domain 1 protein, BAF1, was unaltered by oxygen regulation. Nor were the alternative BAF1 complexes observed by growth in different glucose conditions formed by growth at different oxygen levels.

pH and the cAMP-dependent protein kinase mediate growth phase induction of the cytochrome c oxidase subunit VI gene, COX6, in Saccharomyces cerevisiae.

Respiratory adaptation in Saccharomyces cerevisiae is a complex genetic program that ensures ATP synthesis in a glucose-depleted environment. ATP is generated during respiration by the mitochondrial electron transport chain which is induced by respiratory adaptation. We have studied the terminal enzyme in mitochondrial electron transport, cytochrome c oxidase, from S. cerevisiae. Because subunits in this multisubunit enzyme are coordinately regulated, we have focused upon the well characterized subunit VI gene, COX6. In yeast, COX6 transcription is regulated by several factors thought to mediate respiratory adaptation including growth phase induction, oxygen dependence, and glucose repression. In the present study, we found that in addition to these known regulators, COX6 expression also depends upon pH and the cAMP-dependent protein kinase which may comprise additional factors signaling respiratory adaptation.

The plantaris tendon graft: an ultrasound study.

To assess the value of ultrasound in imaging the plantaris tendon, ultrasounds were done on 26 legs in 25 patients who had a variety of surgical procedures on the posterior leg. Eighteen ultrasounds were done and interpreted before operation and eight after operation by a radiologist. The sonographic results were compared with the status of the plantaris as determined at surgery. The plantaris was present in 21 of 23 patients for a prevalence of 91%. Eighteen plantaris tendons were well visualized on ultrasound for a sensitivity of 86%. Of the three false-negative results, two occurred with thinned plantaris tendons that were less than 2 mm thick and hence considered inadequate for grafting. Therefore, the sensitivity for detecting a tendon suitable for grafting was 95%. All patients with positive studies had a plantaris tendon present for a specificity of 100%. A learning curve for the radiologist was demonstrated. Ultrasound appears to be effective in the preoperative imaging of the plantaris tendon.