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Benthic metabolism and inorganic nitrogen and N2 flux rates (denitrification) were measured in permeable carbonate sands from Heron Island (Great Barrier Reef). Some of the N2 flux rates were among the highest measured in sediments. All benthic fluxes showed a significant difference between seasons with higher rates in summer and late summer. There was no distinct response of the benthic system to mass coral spawning. Instead, changes in benthic fluxes over 12 days in summer appears to be driven by tidal changes in water depth and associated changes in phytosynthetically active radiation reaching the sediments. Dark N2 fluxes were strongly correlated to benthic oxygen consumption across all sites and seasons (r2 = 0.64; p < 0.005; slope = 0.036). However, there were seasonal differences with a steeper slope in summer than winter reflecting either more efficient coupling between respiration and nitrification-denitrification at higher temperatures or different sources of organic matter. Adding data from published studies on carbonate sands revealed two slopes in the dark N2 flux versus benthic oxygen consumption relationship. The lower slope (0.035) was most likely due to high carbon : nitrogen (C : N) organic matter from coral reefs, but competition by benthic microalgae for nitrogen, N-fixation or inefficient coupling between respiration and nitrification-denitrification can not be excluded. The steeper slope (0.089) was most likely due to respiration being driven by low C : N phyto-detritus. If the different slopes were driven by the sources of organic matter then global estimates of continental shelf denitrification are probably about right. In contrast, global estimates of continental shelf may be over-estimated if the low slope was due to inefficient coupling between respiration and nitrification-denitrification and also due to reduced N2 effluxes in the light associated with competition by benthic microalgae for nitrogen and N-fixation.

This chapter will address questions of what polar tourism is and how it has been researched. These questions serve to allow the field to look back upon its research and reflect. However, looking back is not enough. Within a group such as the International Polar Tourism Research Network (IPRTN), we must also attempt to venture forward and ask: how should polar tourism be researched? On the surface these questions seem simple, but when one dives deeper, there is considerable complexity to consider. This chapter will put such questions in context by offering expert reflection on them from three perspectives: academic, community, and industry. This will be done within a geographical scope of both poles and across decades of work. While one can never expect to capture absolutely everything about these questions, this chapter will hopefully contribute to an ongoing conversation of research practices and research relevance moving into the future.

Groundwater discharge could be a major, but as yet poorly constrained, source of carbon dioxide to lakes, wetlands, rivers, estuaries, and coastal waters. We demonstrate how coupled radon ((222)Rn, a natural groundwater tracer) and pCO(2) measurements in water can be easily performed using commercially available gas analysers. Portable, automated radon and pCO(2) gas analysers were connected in series and a closed air loop was established with gas equilibration devices (GED). We experimentally assessed the advantages and disadvantages of six GED. Response times shorter than 30 min for (222)Rn and 5 min for pCO(2) were achieved. Field trials revealed significant positive correlations between (222)Rn and pCO(2) in estuarine waterways and in a mangrove tidal creek, implying that submarine groundwater discharge was a source of CO(2) to surface water. The described system can provide high resolution, high precision concentrations of both radon and pCO(2) with nearly no additional effort compared to measuring only one of these gases. Coupling automated (222)Rn and pCO(2) measurements can provide new insights into how groundwater seepage contributes to aquatic carbon budgets.

[1] Estuaries are ‘hot spots’ in the global carbon cycle, yet data on carbon dynamics, in particular air-sea CO2 fluxes, from autotrophic systems are rare. Estuarine carbon budgets were constructed for three geomorphically distinct warm temperate Australian estuaries over an annual cycle. All three estuaries were net autotrophic, with annual net ecosystem metabolism (NEM) ranging from 8 ± 13.4 molC m−2 yr−1 to 10 ± 14 molC m−2 yr−1. There was a net flux of CO2 from the atmosphere to the estuaries of between 0.4 ± 0.6 molC m−2 yr−1 and 2 ± 0.9 molC m−2 yr−1. Loading of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) to the estuaries varied markedly within and between the estuaries, and was directly related to freshwater inflow. While NEM was similar in all three estuaries, the ratio of benthic versus pelagic contributions to NEM differed, with NEM dominated by pelagic production in the river dominated system, benthic production dominating in the intermediate estuary, and equal contributions of benthic and pelagic production in the marine dominated lagoon. All three estuaries exported more organic carbon than was imported, fueled by additional organic carbon supplied by NEM. The estuaries essentially acted as bioreactors, transforming DIC to organic carbon. Burial of organic carbon ranged from 1.2 ± 0.3 molC m−2 yr−1 to 4.4 ± 1.2 molC m−2 yr−1 and represented up to half of NEM. The annual net uptake of atmospheric CO2 in these systems, along with previous estimates of the global estuarine CO2flux being based predominantly on heterotrophic, large river dominated estuarine systems, indicates that the global estimate of the estuarine air-water CO2flux may be over-estimated due to the lack of studies from autotrophic marine dominated estuaries.

Many academics claim that expedition cruises to the Polar Regions are an emerging market. However, such cruises have frequently visited the Antarctic since the early 1990’s and even earlier in the Arctic, such as the first expedition in 1984 to the territory of Nunavut in the Canadian Arctic. This paper will examine some of the issues and implications that cruise tourism has for protected areas (particularly national parks) that are accessible to expedition cruises throughout the Canadian Arctic. Protected areas contribute to creating a sustainable industry through both their conservation of the landscape, but also in acting as a key attraction and thus economic driver for nearby communities. However, protected areas also rely on a sustainable tourism industry. This paper will utilize empirical data from two studies (2007 and 2009) that examined cruise visitors to Auyuittuq, Sirmilik and Quttinirpaaq National Parks in Nunavut and Torngat Mountains National Park in Nunatsiavut (Northern Labrador), and visitor management of such. In addition, first hand personal experience and knowledge from professional colleagues will be used to underpin survey results. Socio-economic changes, such as the downturn in the global economy effecting demand, occurring in line with environmental changes, such as climate change have significant effects on the Arctic landscape and wildlife. Thus, many levels of government management for these protected areas need to make changes in order to adapt. Cruise tourism in this region is globally connected to other regions and examination of this will also occur.

can play a major role in proton (H + ) cycling in a coral reef lagoon. The diel pH range (up to 0.75 units) in the Heron Island lagoon was the broadest ever reported for reef waters, and the night‐time pH (7.69) was comparable to worst‐case scenario predictions for seawater pH in 2100. The net contribution of coarse carbonate sands to the whole system H + fluxes was only 9% during the day, but approached 100% at night when small scale (i.e., flow and topography‐induced pressure gradients) and large scale (i.e., tidal pumping as traced by radon) seawater recirculation processes were synergistic. Reef lagoon sands were a net sink for H + ,a nd the sink strength was a function of porewater flushing rate. Our observations suggest that the metabolism of advection‐ dominatedcarbonatesandsmayprovideacurrently unknown feedbackto ocean acidification. Citation: Santos, I. R., R. N. Glud, D. Maher, D. Erler, and B. D. Eyre (2011), Diel coral reef acidification driven by porewater advection in permeable carbonate sands, Heron Island, Great Barrier Reef, Geophys. Res. Lett., 38, L03604, doi:10.1029/2010GL046053.

[1] Light and dark benthic dissolved organic carbon (DOC) fluxes and sediment characteristics (total organic carbon (TOC), total nitrogen (TN), TOC isotope ratio (δ13C), phospholipid fatty acid (PLFA) concentration, and compound-specific δ13C) were measured seasonally in a range of habitats in three warm-temperate Australian estuaries to determine what factors control benthic DOC fluxes. Benthic DOC fluxes were seasonal with the highest rates generally observed during summer. Most habitats displayed uptake of DOC during the dark and efflux during the light, and were a net source of DOC to the overlying waters over the diel cycle. Macrophyte habitats (seagrass and macroalgae) had the highest benthic fluxes of DOC (up to ∼50 mmol C m−2 d−1). Organic matter supply to the sediment was dominated by in situ production, and both quantity and source exerted control over benthic DOC fluxes. DOC flux was tightly coupled to bacteria and algal PLFA concentrations during summer, and algal PLFA concentrations during winter, indicating a strong influence of microbial interactions on benthic DOC flux and a temperature-related decoupling of algae and bacteria under cooler conditions. Estimates of the global estuarine benthic DOC flux indicate that these areas are a significant source of DOC to the ocean (1–41 Tg C yr −1). Inclusion of macrophyte, salt marsh, mangrove, and intertidal benthic DOC flux estimates resulted in a higher global continental margin benthic DOC flux (106–416 Tg C yr −1) than the previous estimate (90 Tg C yr−1).

C. elegans and Drosophila generate distinct signaling and adhesive forms of beta-catenin at the level of gene expression. Whether vertebrates, which rely on a single beta-catenin gene, generate unique adhesive and signaling forms at the level of protein modification remains unresolved. We show that beta-catenin unphosphorylated at serine 37 (S37) and threonine 41 (T41), commonly referred to as transcriptionally Active beta-Catenin (ABC), is a minor nuclear-enriched monomeric form of beta-catenin in SW480 cells, which express low levels of E-cadherin. Despite earlier indications, the superior signaling activity of ABC is not due to reduced cadherin binding, as ABC is readily incorporated into cadherin contacts in E-cadherin-restored cells. Beta-catenin phosphorylated at serine 45 (S45) or threonine 41 (T41) (T41/S45) or along the GSK3 regulatory cassette S33, S37 or T41 (S33/37/T41), however, is largely unable to associate with cadherins. Beta-catenin phosphorylated at T41/S45 and unphosphorylated at S37 and T41 is predominantly nuclear, while beta-catenin phosphorylated at S33/37/T41 is mostly cytoplasmic, suggesting that beta-catenin hypophosphorylated at S37 and T41 may be more active in transcription due to its enhanced nuclear accumulation. Evidence that phosphorylation at T41/S45 can be spatially separated from phosphorylations at S33/37/T41 suggests that these phosphorylations may not always be coupled, raising the possibility that phosphorylation at S45 serves a distinct nuclear function.

OBJECTIVE: To evaluate the efficacy of lanreotide Autogel, a depot preparation of a long-acting somatostatin analogue, in patients with acromegaly who were previously treated with octreotide. METHODS: In a prospective single-center, open-label, comparative study, 13 patients were switched from octreotide treatment (baseline) to lanreotide Autogel therapy at a fixed dosage of 90 mg/4 wk. After 6 injections, the dosage was titrated to 60, 90, or 120 mg/4 wk, on the basis of growth hormone (GH) levels, for a further 6 injections. Mean GH and insulinlike growth factor-I (IGF-I) levels were determined at baseline, during treatment (to 48 weeks), and up to 8 weeks after the last injection. RESULTS: There was no significant change in the proportion of patients with GH and IGF-I control from baseline to week 48 (GH, 85% to 89%; IGF-I, 46% to 62%). Mean GH levels changed little from baseline, but mean IGF-I levels were significantly lower after 32 weeks (P

Methyl methacrylate-based (MMA-based) bonding resins have been used in orthodontics because they offer easy removal of both the bonded bracket and the residual adhesive at case completion. However, these materials are not cross-linked, and the brackets bonded with this type of product may undergo drifting when subjected to temperatures slightly higher than those in the mouth. This research investigated the influence of heat on the debonding characteristics of a MMA-based bonding resin compared with those of a BIS-GMA-based system. The temperature of initial bracket movement, as well as of final bracket displacement, was noted for a variety of applied loads (141, 226, 425, 934, and 1727 gm) with stainless steel brackets bonded to etched bovine enamel. The results showed that the MMA-based material underwent a glass transition near 47 degrees C in which the initiation of bracket drift resulted on the tooth surface. This temperature proved independent of the applied load. Further heating resulted in the release of heat from the resin as a result of further curing. The extent of bracket drift associated with this secondary heat release was dependent on the applied load. The debonding temperature of the BIS-GMA-based system was three to six times greater than that of the MMA-based product. Practitioners should be aware that brackets bonded with MMA-based resins have the potential for drifting when subjected to temperatures within the normal range of hot fluids consumed by their patients. Bracket drift could result in deactivation of orthodontic force and could prolong the treatment time.

Heterogeneity in growth hormone (GH) responsiveness in adult hypopituitary patients receiving recombinant human GH (rhGH) is poorly understood; doses vary up to fourfold between individuals. Deletion of exon 3 in the GH receptor (d3-GHR) has been linked to enhanced rhGH responsiveness in children. We investigated the role of the d3-GHR polymorphism in determining adult rhGH responsiveness.One hundred and ninety-four patients treated with an identical rhGH dosing protocol in a single centre were genotyped for the d3-GHR, and the results correlated with changes in serum IGF-I and clinical parameters of GH responsiveness after 6 and 12 months of GH replacement therapy.Allele frequencies for homozygous full length (fl/fl), heterozygous d3 (fl/d3) and homozygous d3 (d3/d3) were 52%, 38.7% and 9.3%, respectively, and were in Hardy-Weinberg equilibrium. Baseline IGF-I and DeltaIGF-I at 6 months were comparable between groups. DeltaIGF-I at 12 months was significantly greater in the d3/d3 group (P = 0.028). No difference was detected between fl/d3 and fl/fl groups. Regression analyses of DeltaIGF-I at 12 months and DeltaIGF-I/rhGH dose confirmed a significant relationship of d3/d3 genotype on rhGH response. There was no difference between groups in maintenance rhGH dose between genotypes.Homozygosity for d3-GHR confers a marginal increase in GH responsiveness at 12 months but without a detectable change in maintenance rhGH dose required. Both d3 alleles are required to achieve this response; given that only 10% of the population are d3 homozygotes, the d3GHR does not explain the marked heterogeneity of GH responsiveness in hypopituitary adults.

Background β-catenin is a dual function adhesion/transcriptional co-activator protein, and both functions are critical for normal tissue homeostasis. Since the transcriptional functions of β-catenin are more often implicated in various disease processes, there is much interest in the development and use of reagents to interrogate spatial and temporal evidence of β-catenin nuclear signaling in cells and tissues. An important study demonstrated that the signaling form of β-catenin is specifically unphosphorylated at residues S37 and T41, and suggested that this form exhibits a propensity for cytosolic/nuclear accumulation relative to the total pool of β-catenin. Results We show that monoclonal antibody, 8E7, which recognizes the signaling form of β-catenin specifically unphosphorylated at S37 and T41 (Active B-Catenin, ABC), also cross-reacts with a widely expressed, variably accessible nuclear antigen that is not β-catenin. In cell types commonly used to study Wnt activation, this non-specific nuclear staining can be robust, obscuring the ABC signal. Definitive detection of nuclear localized ABC can be confirmed through an ability of classical cadherins to sequester ABC to cell junctions. In tissues, milder antigen retrieval methods can reduce the accessibility of mAb 8E7 to this cross-reacting nuclear antigen. Conclusion These findings reveal that interpretation of nuclear, signaling active β-catenin using monoclonal antibody 8E7 should be considered judiciously, and in conjunction with independent methods. Reviewers This article was reviewed by Frank J. T. Staal (nominated by Rachel Gerstein), Jyoti M. Sen (nominated by Avinash Bhandoola) and Manabu Sugai.

Summary Objective GH dose requirement is lower in ACTH replete compared with ACTH deficient hypopituitary patients suggesting that adrenal androgens may augment IGF-I generation for a given GH dose. This study aimed to determine the effect of dehydroepiandrosterone (DHEA) administration on GH dose requirements in hypopituitary adults. Design A double blind placebo controlled trial was conducted adding 50 mg DHEA to the standard replacement of hypopituitary patients, including GH, over an initial 6 months, followed by an open phase study of 6 months DHEA replacement and a final 2 month washout phase after DHEA withdrawal. The dose of GH was adjusted to achieve a constant serum IGF-I. Patients Thirty female and 21 male hypopituitary patients were enrolled. Data from 26 women and 18 men were analysed after patient withdrawal. Measurements The primary outcome objective was the GH dose required to achieve a stable serum IGF-I. Secondary outcome measures were lipoprotein profiles, insulin, insulin sensitivity, IGFBP-3, waist/hip ratio and indices of bone remodelling. Results DHEA replacement in female patients lead to a 14·6 ± 20% reduction in the dose of GH for a constant serum IGF-I (P

The effects on the radiation pattern when N pairs of symmetrically located radiators are removed at random from a large ( 2N_{o} + 1 )-element linear array are studied as a statistical problem. It has been possible to determine the limiting bounds of the radiation pattern, the probability that the main-lobe beamwidth is widened by not more than a given percentage, the probability that a certain side lobe does not deteriorate by a specified amount, and the probability that all side lobes are below a specified level. The general analysis is valid for arrays with an arbitrary amplitude distribution which is symmetrical with respect to the center element and with an arbitrary progressive phase shift. Curves showing computed statistical data for a 201-element array with both the uniform and a cosine-squared amplitude distribution are presented.

The HEART project was conducted in general practice to determine whether lifestyle strategies, aimed at increasing physical activity and dietary modification, can be substituted for drug therapy in patients who have been well controlled on antihypertensive medication. In addition to blood pressure (BP) and risk factor outcomes, lifestyle behaviours, quality of life of patients, and the acceptability of the approach to both general practitioners (GPs) and patients involved in the trial were assessed. Patients (n = 45) with a history of hypertension and who had been well controlled for at least the past 6 months (BP < 160/ 95 mmHg) were randomised to a continued medication (C) group (n = 24) or a withdrawal (W) group (n = 21). Subjects had received antihypertensive therapy for an average of 7.8 years (range 1-28 years). Drug therapy in the W group was recommenced if BP exceeded 160/95 mmHg on two consecutive visits. Both groups were counselled regarding lifestyle behaviour change by their GP throughout the study and were provided with specifically developed self-help materials. Subjects were reviewed at least monthly over a 9-month period. Following randomisation, there were no significant differences between the two groups for BP, heart rate, age, duration of therapy, total cholesterol or body mass index. All but three subjects (one from the W and two from the C group) completed 9 months of monitoring following randomisation and there were no cardiovascular events; 71% of subjects remained off drug therapy and were well controlled at the 9-month follow-up (15/21) with mean BP of 141/85 mmHg (W) and 139/ 86 mmHg (C). Systolic BP tended to increase during the study period in both W and C groups, however, no significant differences were observed in mean systolic or diastolic BP either between the two groups or within each group in comparison to baseline values. Resting heart rate, body mass index and cholesterol levels remained unchanged in both W and C groups after 9 months follow-up. There were no changes attributable to the lifestyle intervention in the subjects continuing drug therapy in BP or lifestyle variables over the study period. However, the group stopping therapy had a 6% reduction in body mass index after 9 months. These data suggest that a proportion of motivated patients willing to trial a lifestyle approach can cease drug therapy and be adequately maintained by the prescription of lifestyle advice via their GP for at least a 9-month period. Cessation of drug therapy may be an important motivating factor to achieve weight loss in this group.

This study describes the preventive health behaviour of general practitioners in Victoria, with particular emphasis on hepatitis B prevention, and their use of medical services, and seeks to explain these behaviours.Cross sectional postal questionnaire survey of a 10% random sample (n = 544) of all GPs in Victoria, Australia.A valid response rate of 58.5% was achieved. Only 4% of the sample smoked, 93% had a blood pressure check in the past 3 years, and 64% had a cholesterol check in the past 3 years. About half followed a 'healthy' diet and 20% took a high level of physical exercise. With regard to hepatitis B prevention, 87% had completed vaccination, and 49% had confirmed immunity. Needlestick injuries had been suffered by 49% in the previous year, and half of the respondents would take no action after such an event. Over two-thirds (69%) reported having no GP. Psychological factors were associated with preventive health behaviour independent of age and gender. Internal locus of control and health value were positively associated with whether the doctor would take any action after needlestick injury, had a blood pressure or cholesterol test in the past 3 years or had their own GP.This study shows that GPs in Victoria have a relatively high level of preventive health activity although they have a low level of utilisation of their GP colleagues in service provision. There are measurable differences in psychological variables between doctors that are associated with their level of preventive care. Plans to improve their personal health care should concentrate on psychological well being.

Objective To compare umbilical cord blood gas values in newborns with and without true knots, and to assess the potential impact of true knot formation on cord blood gases. Methods Twelve newborn infants with true umbilical cord knots were identified and compared with a random control population of 104 newborn infants without true knots. The two groups were analyzed for 11 maternal-fetal variables to determine if they were comparable. Subsequently, the principal outcome variable of the study was evaluated: a comparison between the umbilical arterial and venous blood gas results of the true knot and control populations. Results The true knot and control populations were comparable with respect to the maternal-fetal variables analyzed. The umbilical cord blood gas values did not differ between groups, except for a slightly lower umbilical artery bicarbonate value in the control group (22.0 mEq/L) versus the true knot group (24.5 mEq/L), P = .025. There was no significant difference in the incidence of acidemia (umbilical artery pH less than 7.20) between the two groups. Conclusion The presence of true umbilical cord knots does not alter the incidence of umbilical artery acidemia or change umbilical cord blood gas values. Review of the pertinent obstetric literature supports the hypothesis that true umbilical cord knots lack clinical significance.

The thematic cluster ‘‘Human impacts in the Arctic and Antarctic’’ in Polar Research has its origins in the International Polar Year (2007-09) Oslo Science Conference held in Oslo, Norway, from 8 to 12 June 2010. We were the co-convenors of the session ‘‘Human impacts in the Arctic and Antarctic: regulatory and management implications,’’ in which 27 talks and 21 posters were presented over the course of two days. We invited contributors to the conference session to explore all types of impacts of human activities and regional environmental change in the polar regions, with a special focus on highlighting the management priorities for the protection of the landscape (environment and people) of the polar regions in the face of increasing human activity. Exploring a wide range of topics ranging from human wildlife interactions to chemical contamination and from whaling to polar tourism, contributors provided examples of existing environmental management regimes that are working as well as those that are not. (Published: 28 December 2012) Citation: Polar Research 2012, 31, 20228, http://dx.doi.org/10.3402/polar.v31i0.20228

To determine what events are perceived as most stressful to patients in the surgical intensive care unit (SICU).Descriptive cross-sectional survey.One hundred twenty-seven patients who had undergone coronary artery bypass graft (CABG) at 48 hours after their transfer from the SICU.Stressful events as perceived by patients while in the SICU determined by 25 specific items on a questionnaire rated on a Likert scale ranging from 1 (no distress) to 4 (extremely distressful).Two stressors, being intubated and not being able to talk, were significantly more stressful, by Newman-Keuls multiple range test, than all the other stressors. The mean stressfulness score for all other stressors was between no distress and mild distress.Overall stress associated with specific events during a short stay in the SICU was minimal. Intubation and inability to communicate were the most stressful experiences.

A rapid, simple elastic-trichrome stain is described. The combined method reliably and with clear contrast demonstrates vascular and bronchiolar architecture, allowing examination of all components within a single section. The stain has similar utility in many tissues, making it ideal for diagnostic, teaching, or research situations. (The J Histotechnol 14:191, 1991)

We examined the relationships between abundance of 16 species of waterbirds and the rainfall in eastern Australia, the rainfall west of this region, the annual Southern Oscillation index (SOI), the wetland area, and hunting in eastern Australia for the period 1983–92. Data were collected during aerial surveys of eastern Australia. For most explanatory variables, lags of up to five years before aerial surveys were also investigated during these analyses. The analyses covered all nine game species (plumed whistling-duck, Australian shelduck, Australian wood duck, pink-eared duck, grey teal, chestnut teal, Pacific black duck, Australasian shoveler, hardhead) and seven non-game species (Australian pelican, white-faced heron, yellow-billed spoonbill, freckled duck, black swan, black-winged stilt, red-necked avocet). Regression models were developed for all species apart from Australian pelicans. Rainfall and climate indices generally were most correlated with the species’ abundance. Bonferroni adjustments to significance levels meant that there were significant variables in regression models for seven of the 16 species. Abundance indices for plumed whistling-duck, chestnut teal, hardhead, black swan and black-winged stilt were related to the climate variables (rainfall, SOI) and wetland area, whereas abundance of pink-eared duck and red-necked avocets were negatively related. Abundance of chestnut teal was positively related to numbers of hunting licences sold. The results are equivocal about the role of hunting in determining waterfowl abundance, which is probably a reflection of few data points and numbers of variables included. In general, abundance indices of waterbirds appear to have decreased between 1983 and 1992, which may correspond to other factors not modelled

To the Editor. —Dr Cockerill and colleagues 1 present interesting and relevant information that underscores an urgent need for the development of a consensus related to the management of the invasive streptococcal carrier state. As the authors point out, there is currently little agreement among physicians regarding the treatment of patients with asymptomatic streptococcal infection. In fact, some experts view this as a benign condition that poses no direct risk to patients or to their contacts and therefore requires no intervention. 2 As a practical matter, we disagree with this passive posture. The study performed by Cockerill et al and common sense support the notion that eradication of this pathogen in the carrier state seems to serve the best interests of both the child and the community. During a recent outbreak of group A streptococcal disease, our clinic undertook a study that compared 2 currently accepted treatment options for eradication

Large hygroscopic particles in the size range 0.5–200 ??g were collected on flights in central Queensland. The particles crystallized into distinct cubic shapes and were sized according to the volumes of these cubes. The concentrations so obtained showed only small variations in the vertical from 200 m to 1000 m and the shapes of the cumulative mass curves were similar to those measured near Hawaii. At cloud base levels (typically 1000 m), the concentrations decreased only slowly with distance inland—a penetration of 1100 km reduced the concentrations by a factor of five. It was found that the vertical and horizontal variations in the concentrations could be fitted to Tanaka's model quite well provided that the decrease associated with the pressure dependence on altitude was recognized. Preliminary chemical tests showed that the particles were mostly chloride with a small fraction of sulphate, and between 50 and 80 per cent contained some nitrate. DOI: 10.1111/j.2153-3490.1976.tb00646.x

Dry matter and nutrient loss from Vallisneria spiralis leaves submerged in leaf packs were measured in a shallow wetland in inland southeastern Australia. Rates of dry matter loss in the first 24 h were rapid (27 and 30% for oven-dried material; 34% for fresh material), and the number of days for > 95% loss was comparatively low compared with other submerged macrophytes. Percentages of sodium and potassium in oven-dried material were lower after 24 h, while the other nutrients did not alter.

Factors affecting anthocyanin recovery in juice from pressed cranberries (Vaccinium macrocarpon Ait.) were investigated under laboratory conditions. Anthocyanin recovery was unaffected by cultivar, total anthocyanin content, or juice yield. Variability in anthocyanin recovery was attributed to the heterogeneity of berry samples analyzed for total and juice anthocyanin and to differences in the efficiency of pigment extraction by juice liberated during pressing. Freeze-thaw treatment of cranberries increased juice yield by as much as 50% and juice anthocyanin content by as much as 15-fold. Microscopic observation of changes at the cellular level resulting from freeze-thaw treatment supported the juice yield and pigment recovery data. Anthocyanin recovery could be increased by double pressing and by tissue homogenization.

To evaluate the cardiocirculatory changes induced by acute hypoxic stress, rate corrected electro-mechanical systole (QS2)) left ventricular ejection time (LVET), and preejection period (PEP) were determined in 11 healthy males at sea level (SL) and after 2 h at a simulated altitude (HA) of 4,300 m. Recordings were made at rest and at 15 min of upright bicycle exercise at light and moderately heavy loads (40 and 75% of Vo2 max, respectively). Venous blood was withdrawn simultaneously for estimation of total plasma catecholamines (CATS). Exposure to HA produced a significant decrease in each interval at rest with differences narrowing progressively with exercise of increasing intensity. PEP/LVET ratio decreased progressively with graded exercise at SL indicating an enhancement of left ventricular performance that was directly related to the elevation in plasma CATS. Cardiac performance was augmented at rest during HA exposure, despite a normal level of CATS. However, during moderately heavy exercise at HA, when the plasma CATS were increased to twice the SL values, cardiac performance, as reflected by the PEP/LVET ratio, did not increase proportionately. It is postulated that the depressant effect of increased hypoxemia and acidosis during moderately heavy exercise in HA may override the cardiostimulatory influence of circulating CATS.

This paper discusses a process hazard management study of a fuel gas conditioning facility based on stateof-the-art fault tree analysis techniques. This facility lowers the water and hydrocarbon dewpoints of a high pressure fuel gas exposed to frigid temperatures during distribution. Using hazards checklists and guidelines as well as internal reviews, various process hazards were identified for this facility. Computerized fault tree analysis techniques were used to identify the failure sequences which could lead to process hazards, and analysts used these results to evaluate the impact of specific hazards upon process safety. Through recommendations presented in the study, the facility owner gained an increased awareness of potential problems and made modifications to reduce the possibility of a hazardous condition and subsequent catastrophic failure. Dans cet article, on presente une etude de gestion du risque d'un systeme de conditionnement de gaz combustibles basee sur les techniques les plus recentes d'analyse par arbre d'erreurs. Ce dispositif a pour objectif d'abaisser les points de rosee de l'eau et des hydrocarbures dans un gaz combustible a haute pression qui doit ětre expose a de basses temperatures lors de sa distribution. Plusieurs risques ont pu ětre identifies pour cet appareillage en utilisant les listes de verifications et les consignee donnees ainsi que des rapports internes. On a utilise des techniques d'analyse informatiques par arbre d'erreurs afin d'identifier les sequences de malfonctionnement susceptibles de conduire a un danger et des analystes ont utilise ces resultats pour evaluer l'impact d'evenements fortuits specifiques sur la securite du procede. Grǎce aux recommandations presentees dans l'etude, le proprietaire de l'installation est devenu plus conscient des problemes pouvant survenir et a pu faire des modifications pour diminuer la probabilite des catastrophes qui peuvent en decouler.

A further 400 h of flying experience with the CSIRO hot-wire probe has shown that it can accurately measure liquid water content in clouds. Computations and experiments suggest that when an epoxy coating is used for protection, it should be less than 50 μm thick, and that the wire should be operated around 160°C when such coatings are used. Comparisons of performance with the Axially Scattering Spectrometer Probe and in a wet wind tunnel indicate that splashing of drops up to 40 μm diameter is not a problem at speeds up to 80 m s−1.