Geogenic sources and sinks of trace metals in the Larsemann Hills, East Antarctica: Natural processes and human impact

To evaluate the extent of human impact on a pristine Antarctic environment, natural baseline levels of trace metals have been established in the basement rocks of the Larsemann Hills, East Antarctica. From a mineralogical and geochemical point of view the Larsemann Hills basement is relatively homogeneous, and contains high levels of Pb, Th and U. These may become soluble during the relatively mild Antarctic summer and be transported to lake waters by surface and subsurface melt water. Melt waters may also be locally enriched in V, Cr, Co, Ni, Zn and Sri derived from weathering of metabasite pods. With a few notable exceptions, the trace metal concentrations measured in the Larsemann Hills lake waters can be entirely accounted for by natural processes such as sea spray and surface melt water input. Thus, the amount of trace metals released by weathering of basement lithologies and dispersed into the Larsemann Hills environment, and presumably in similar Antarctic environments, is, in general, not negligible, and may locally be substantial. The Larsemann Hills sediments are coarse-grained and contain minute amounts of clay-size particles, although human activities have contributed to the generation of fine-grained material at the most impacted sites. Irrespective of their origin, these small amounts of fine-grained clastic sediments have a relatively small surface area and charge, and are not as effective metal sinks as the abundant, thick cyanobacterial algal mats that cover the lake floors. Thus, the concentration of trace metals in the Larsemann Hills lake waters is regulated by biological activity and thawing-freezing cycles, rather than by the type and amount of clastic sediment supply. (c) 2005 Elsevier Ltd. All rights reserved.

Trace metals in Antarctic ecosystems: Results from the Larsemann Hills, East Antarctica

Sediments, mosses and algae, collected from lake catchments of the Larsemann Hills, East Antarctica, were analysed to establish baseline levels of trace metals (Ag, As, Cd, Co, Cr, Cu, Ni, Sb, Pb, Se, V and Zn), and to quantify the extent of trace metal pollution in the area. Both impacted and non-impacted sites were included in the study. Four different leaching solutions (1 M MgCl2, 1 M CH3COONH4, 1 M NH4NO3, and 0.3 N HCl) were tested on the fine fraction (< 63 mu m) of the sediments to extract the mobile fraction of trace metals derived from human impact and from weathering of basement lithologies. Results of these tests indicate that dilute HCl partly dissolves primary minerals present in the sediment, thus leading to an overestimate of the mobile trace metal fraction. Concentrations of trace metals released using the other 3 procedures indicate negligible levels of anthropogenic contribution to the trace metal budget. Data derived from this study and a thorough characterisation of the site allowed the authors to define natural baseline levels of trace metals in sediments, mosses and algae, and their spatial variability across the area. The results show that, with a few notable exceptions, human activities at the research stations have contributed negligible levels (lower than natural variability) of trace metals to the Larsemann Hills ecosystem. This study further demonstrates that anthropogenic sources of trace metals can be correctly identified and quantified only if natural baselines, their variability, and processes controlling the mobility of trace metals in the ecosystem, have been fully characterised. (c) 2006 Elsevier Ltd. All rights reserved.

Selection of species and provenances for low-rainfall areas: physiological responses of Eucalyptus cloeziana and Eucalyptus argophloia to seasonal conditions in subtropical Queensland

Responses of stomatal conductance (g(s)) and net photosynthesis (A) to changes in soil water availability, photosynthetic photon flux density (Q), air temperature (1) and leaf-to-air vapour pressure deficit (D) were investigated in 4-year-old trees of a dry inland provenance of Eucalyptus argophloia Blakely, and two dry inland provenances (Coominglah and Hungry Hills) and a humid coastal provenance (Wolvi) of Eucalyptus cloeziana F. Muell. between April 2001 and April 2002 in southeast Queensland, Australia. There were minimal differences in A, g, and water relations variables among the coastal and inland provenances of E. cloeziana but large differences between E. argophloia and E. cloeziana. E. argophloia and to a lesser extent the Hungry Hills (inland) provenance of E. cloeziana maintained relatively higher pre-dawn water potential (psi(pd)) during the dry season suggesting possible access to water at depth. Simple phenomenological models of stomatal conductance as a function of Q, T and D explained 60% of variation in gs in E. cloeziana and more than 75% in E. argophloia, when seasonal effect was incorporated in the model. A Ball-Berry model for net photosynthesis explained between 70 and 80% of observed variation in A in both species. These results have implications in matching the dry and humid provenances of E. cloeziana and E. argophloia to suitable sites in subtropical environments. (C) 2004 Elsevier B.V. All rights reserved.

Physiological responses to water stress in Eucalyptus cloeziana and E-argophloia seedlings

Effects of water stress duration and intensity on gas exchange and leaf water potential were investigated in 7-month-old seedlings of a humid coastal provenance (Gympie) and a dry inland (Hungry Hills) provenance of E. cloeziana F. Muell. and in a dry inland (Chinchilla) provenance of E. argophloia Blakely supplied with 100% (T-100), 70% (T-70), 50% (T-50) of their water requirements, or were watered only after they were wilted at dawn (T-0). Seedlings of E. argophloia had the highest midday net photosynthetic rate (A), stomata] conductance (g(s)), stomatal density and predawn leaf water potential (Psi(pd)) in all treatments. The E. cloeziana provenances did not differ in these attributes. The T-70 and T-50 treatments caused reductions in A of 30% in E. argophloia, and 55% in the E. cloeziana provenances. Under the T-0 treatment, E. argophloia maintained higher rates of gas exchange at all levels of water stress than E. cloeziana provenances. The estimates of Psi(pd) and midday water potential (Psi(md)) at which plants remained wilted overnight were respectively: -2.7 and -4.1 MPa for E. cloeziana (humid), -2.8 and -4.0 MPa for E. cloeziana (dry) and, -3.7 and -4.9 MPa for E. argophloia. Following stress relief, both A and g(s) recovered more quickly in E. argophloia and in the dry provenance of E. cloeziana than in the humid provenance. We conclude that E. argophloia is more drought tolerant and has a potential for cultivation in the humid and semi humid climates, whilst E. cloeziana has greater potential in the humid subtropical climates.

Primary personality trait correlates of religious practice and orientation

The aim of the study was to examine the relationships between Eysenck's primary personality factors and various aspects of religious orientation and practice. Some 400 UK undergraduates completed questionnaires constructed from the Batson and Schoenrade Religious Life Inventory (Batson & Schoenrade, 1991) and the Eysenck Personality Profiler (Eysenck, Barrett, Wilson, & Jackson, 1992). As is generally found, all the religious variables correlated negatively with the higher order personality factor of psychoticism. In contrast, among the primary factors, those associated with neuroticism appeared to be the strongest indicators of religiosity. In particular, all the primary traits classically linked to neuroticism correlate positively with the quest orientation. However, fewer primary traits predict religious behaviour in regression and of these, a sense of guilt is the greatest and a common predictor of extrinsic, intrinsic and quest religiosities. Upon factor analysis of the significant personality predictors together with the three religious orientations, the orientations formed a single discrete factor, which implies that extrinsic, intrinsic and quest religiosities have more in common with one another than with any of the personality traits included in the study. This suggests that religious awareness may itself be an important individual difference that is distinct from those generally associated with models of personality. (C) 2003 Elsevier Ltd. All rights reserved.

The igneous charnockite—high-K alkali-calcic I-type granite—incipient charnockite association in Trivandrum Block, southern India

The Pan-African (640 Ma) Chengannoor granite intrudes the NW margin of the Neoproterozoic high-grade metamorphic terrain of the Trivandrum Block (TB), southern India, and is spatially associated with the Cardamom hills igneous charnockite massif (CM). Geochemical features characterize the Chengannoor granite as high-K alkali-calcic I-type granite. Within the constraints imposed by the high temperature, anhydrous, K-rich nature of the magmas, comparison with recent experimental studies on various granitold source compositions, and trace- and rare-earth-element modelling, the distinctive features of the Chengannoor granite reflect a source rock of igneous charnockitic nature. A petrogenetic model is proposed whereby there was a period of basaltic underplating; the partial melting of this basaltic lower crust formed the CM charnockites. The Chengannoor granite was produced by the partial melting of the charnoenderbites from the CM, with subsequent fractionation dominated by feldspars. In a regional context, the Chengannoor I-type granite is considered as a possible heat source for the near-UHT nature of metamorphism in the northern part of the TB. This is different from previous studies, which favoured CM charnockite as the major heat source. The Occurrence of incipient charnockites (both large scale as well as small scale) adjacent to the granite as well as pegmatites (which contain CO2, CO2-H2O, F and other volatiles), suggests that the fluids expelled from the alkaline magma upon solidification generated incipient charnockites through fluid-induced lowering of water activity. Thus the granite and associated alkaline pegmatites acted as conduits for the transfer of heat and volatiles in the Achankovil Shear Zone area, causing pervasive as well as patchy charnockite formation. The transport Of CO2 by felsic melts through the southern Indian middle crust is suggested to be part of a crustal-scale fluid system that linked mantle heat and CO2 input with upward migration of crustally derived felsic melts and incipient charnockite formation, resulting in an igneous charnockite - I-type granite - incipient charnockite association.

Differences in surfactant lipids collected from pleural and pulmonary lining fluids

Purpose. The type and relative importance of saturated and unsaturated phospholipid components of surfactant within the epithelial lining fluid (ELF) of the inner and outer surfaces of the lung is not known. Methods. Seven healthy dogs were anesthetized and a bronchoalveolar lavage (BAL) was performed, immediately followed by a pleural lavage (PL). Lipid was extracted from lavage fluid and then analyzed for saturated, primarily dipalmitoylphosphatidylcholine (DPPC), and unsaturated phosphatidylcholine (PC) species using high-performance liquid chromatography (HPLC) with combined fluorescence and ultraviolet detection. Dilution of ELF in lavage fluids was corrected for using the urea method. Results. DPPC (494.7 +/- 213.9 mu g/mL) was the predominant PC present in ELF collected from the alveolar surface. In contrast, significantly higher (p = 0.028) proportions of unsaturated PC species were measured in PL fluid (similar to 105 mu g/mL), particularly stearoyl-linoleoyl-phosphatidylcholine (SLPC), which could not be measured in fluid collected from the alveoli, compared to DPPC (2.6 +/- 2.0 mu g/mL). Conclusions. This study indicates that unsaturated PC species seem to be more important than saturated species, particularly DPPC, in the pleural cavity, which has implications for surfactant replenishment following pleural disease or thoracic surgery.

Surface-active phospholipid (surfactant) in equine tendon and tendon sheath fluid

AIM: To investigate the presence of surface-active phospholipid (SAPL, or surfactant) in equine tendon and tendon sheath fluid. METHODS: The left front flexor tendon and sheath were removed from five Thoroughbred horses. Phospholipid was extracted from tendon sheath fluid using Folch reagent and quantified using spectroscopy. Transmission electron microscopy (TEM) was used to observe the tendon surfaces. RESULTS: The presence of phospholipid (90.6 (SD 4.3) mu g/ml) in tendon sheath fluid, plus the appearance of oligolamellar layers and lamellar bodies on the tendon surface were indicative of SAPL. CONCLUSIONS: Evidence of SAPL was found in equine tendon, and may have a similar lubricating function as reported for synovial joints. CLINICAL RELEVANCE: These findings may have important implications for normal tendon function and possible therapeutic adjuncts for tendon and tendon sheath injuries.

Resting energy expenditure is lower than predicted in people taking atypical antipsychotic medication

Resting energy expenditure (REE) is lower than predicted in persons taking atypical antipsychotic medication, and weight management is a significant clinical challenge for some of them. However, to date there have been no published guidelines to assist clinicians in choosing appropriate prediction equations to estimate energy expenditure in persons taking atypical antipsychotic medications. The objectives of this study were to measure REE in a group of men taking the atypical antipsychotic clozapine and to determine whether REE can be accurately predicted for this population using previously published regression equations. REE was measured using indirect calorimetry via a ventilated hood on eight men who had completed at least 6 months of treatment with clozapine. Comparisons between measured REE and predicted REE using five different equations were undertaken. The commonly-used Harris-Benedict and Schofield equations systematically overestimated REE. Predictions of REE from other equations were too variable for clinical use. When estimating energy requirements as part of a weight-management program in men who have been taking clozapine for 6 months, predictions of REE from the equations of Harris-Benedict and Schofield should be reduced by 280 kcal/day.

Dinosaur sanctuary on the Chatham Islands, Southwest Pacific: First record of theropods from the K-T boundary Takatika Grit

Cretaceous-Tertiaty (K-T) boundary (ca. 65 Ma) sections on a Southwest Pacific island containing dinosaurs were unknown until March 2003 when theropod bones were recovered from the Takatika Grit on the remote Chatham Islands (latitude 44 degrees S, longitude 176 degrees W), along the Chatham Rise. Tectonic and palaeontologic evidence support the eastward extension of a ca. 900 km land bridge that connected the islands to what is now New Zealand prior to the K-T boundary. The Chathams terrestrial fauna inhabited coastal, temperate environments along a low-lying, narrow, crustal extension of the New Zealand subcontinent, characterised by a tectonically dynamic, volcanic landscape with eroding hills (horsts) adjacent to flood plains and deltas, all sediments accumulating in grabens. This finger-like tract was blanketed with a conifer and clubmoss (Lycopodiopsida) dominated forest. The Chatham Islands region would have, along with New Zealand, provided a dinosaur island sanctuary after separating from the Gondwana margin ca. 80 Ma. (c) 2005 Elsevier B.V. All rights reserved.

'Free' surfactant in gastric aspirates and bronchoalveolar lavage in children with and without reflux oesophagitis

Aim: Dipalmitoylphosphatidycholine (DPPC) is the characteristic and main constituent of surfactant. Adsorption of surfactant to epithelial surfaces may be important in the masking of receptors. The aims of the study were to (i) compare the quantity of free DPPC in the airways and gastric aspirates of children with gastroesophageal reflux disease (GORD) to those without and (ii) describe the association between free DPPC levels with airway cellular profile and capsaicin cough sensitivity. Methods: Children aged < 14 years were defined as 'coughers' if a history of cough in association with their GORD symptoms was elicited before gastric aspirates and nonbronchoscopic bronchoalveolar lavage (BAL) were obtained during elective flexible upper gastrointestinal endoscopy. GORD was defined as histological presence of reflux oesophagitis. Spirometry and capsaicin cough-sensitivity test was carried out in children aged > 6 years before the endoscopy. Results: Median age of the 68 children was 9 years (interquartile range (IQR) 7.2). Median DPPC level in BAL of children with cough (72.7 mu g/mL) was similar to noncoughers (88.5). There was also no significant difference in DPPC levels in both BAL and gastric aspirates of children classified according to presence of GORD. There was no correlation between DPPC levels and cellular counts or capsaicin cough-sensitivity outcome measures. Conclusion: We conclude that free DPPC levels in the airways and gastric aspirate is not influenced by presence of cough or GORD defined by histological presence of reflux oesophagitis. Whether quantification of adsorbed surfactant differs in these groups remain unknown. Free DPPC is unlikely to have a role in masking of airway receptors.

Microarray-based comparative genomic hybridisation of breast cancer patients receiving neoadjuvant chemotherapy

We analysed the molecular genetic profiles of breast cancer samples before and after neoadjuvant chemotherapy with combination doxorubicin and cyclophosphamide (AC). DNA was obtained from microdissected frozen breast core biopsies from 44 patients before chemotherapy. Additional samples were obtained before the second course of chemotherapy (D21) and after the completion of the treatment (surgical specimens) in 17 and 21 patients, respectively. Microarray-based comparative genome hybridisation was performed using a platform containing approx5800 bacterial artificial chromosome clones (genome-wide resolution: 0.9 Mb). Analysis of the 44 pretreatment biopsies revealed that losses of 4p, 4q, 5q, 12q13.11–12q13.12, 17p11.2 and 17q11.2; and gains of 1p, 2p, 7q, 9p, 11q, 19p and 19q were significantly associated with oestrogen receptor negativity. 16q21–q22.1 losses were associated with lobular and 8q24 gains with ductal types. Losses of 5q33.3–q4 and 18p11.31 and gains of 6p25.1–p25.2 and Xp11.4 were associated with HER2 amplification. No correlations between DNA copy number changes and clinical response to AC were found. Microarray-based comparative genome hybridisation analysis of matched pretreatment and D21 biopsies failed to identify statistically significant differences, whereas a comparison between matched pretreatment and surgical samples revealed a statistically significant acquired copy number gain on 11p15.2–11p15.5. The modest chemotherapy-driven genomic changes, despite profound loss of cell numbers, suggest that there is little therapeutic selection of resistant non-modal cell lineages.

Comparison of surfactant lipids between pleural and pulmonary lining fluids

Saturated phospholipids (PCs), particularly dipalmitoylphosphatidylcholine (DPPC), predominate in surfactant lining the alveoli, although little is known about the relationship between saturated and unsaturated PCs on the outer surface of the lung, the pleura. Seven healthy cats were anesthetized and a bronchoalveolar lavage (BAL) was performed, immediately followed by a pleural lavage (PL). Lipid was extracted from lavage fluid and then analyzed for saturated, primarily dipalmitoylphosphatidylcholine (DPPC), and unsaturated PC species using high-performance liquid chromatography (HPLC) with combined fluorescence and ultraviolet detection. Dilution of epithelial lining fluid (ELF) in lavage fluids was corrected for using the urea method. The concentration of DPPC in BAL fluid (85.3 +/- 15.7 mu g/mL) was significantly higher (P=0.021) than unsaturated PCs (similar to 40 mu g/mL). However, unsaturated PCs (similar to 34 mu g/mL), particularly stearoyl-linoleoyl-phosphatidylcholine (SLPC; 17.4 +/- 6.8), were significantly higher (P = 0.021) than DPPC (4.3 +/- 1.8 mu g/mL) in PL fluid. These results show that unsaturated PCs appear functionally more important in the pleural cavity, which may have implications for surfactant replenishment following pleural disease or thoracic surgery. (c) 2005 Published by Elsevier Ltd.