bluuebunny/crossref_metadata_2025 huggingface dataset:
Gender moderates the impact of need for structure on social beliefs: Implications for ethnocentrism and authoritarianism
Authors: Kemmelmeier Markus
Published: February 2010

The present research examines the interplay between individual differences in need for structure, social beliefs, and gender. It is well documented that need for structure, that is, a preference for structure and simplicity in one's thinking, predicts authoritarianism and ethnocentrism. Further, women tend to score lower in authoritarianism and ethnocentrism than men. Although there seem to be no gender differences in need for structure, the present research hypothesizes that the association between need for structure and social beliefs is stronger for men than for women. This hypothesis comes from the observation that, all else being equal, men tend to think more about the domain of beliefs such as authoritarianism and ethnocentrism, which should strengthen the relationship between men's cognitive needs and their social beliefs. The hypothesis is also motivated by the finding that, more than men, women often give priority to caring and compassion when forming beliefs about outgroups. This should weaken the link between women's cognitive needs and their social beliefs. Three studies conducted in the USA (n = 398) and one study conducted in Germany (n = 112) examined whether gender moderated the influence of need for structure on authoritarianism and racism. Using a variety of measures, need for structure predicted authoritarianism and racism for men, but not for women. The discussion focuses on the implications of the present findings for the relationship between cognitive orientations and social beliefs. It is argued that research on cognitive orientation and social beliefs needs to take gender into account to improve its accuracy of prediction.
Military Industry versus Military-Related Firms in Socialist Hungary: Disintegration and Integration of Military Production during the 1950s and Early 1960s
Authors: Germuska Pál
Published: February 2010

The article presents some new evidence concerning the conversion program in Socialist Hungary that constituted an exceptional case not only in the Socialist Bloc, but also in the early period of the Cold War. The Hungarian military industry—step by step—was reintegrated into the civil economy between 1953 and 1961. The war plants developed a dual production structure, which helped them stand the storms of the lengthy transitional period. Companies with a double profile diversified their production with a wide scale of civilian goods, new constructional and R&D departments were established. The article examines at the firm level the strategies, the changes in behaviours of the top-managers, and the consequences—what did the switch-over have for Hungarian society, to what extent contributed the increase in consumer goods to political stabilization of the system.
State Ownership and International Competitiveness: The Italian Finmeccanica from Alfa Romeo to Aerospace and Defense (1947–2007)
Authors: Felice Emanuele
Published: February 2010

The article reconstructs the history of the Italian state-owned holding Finmeccanica, which since its birth in 1948 lived through a number of corporate reorganizations (shipyards, automobiles with Alfa Romeo, energy) and is now one of the leading European companies in aerospace and defence. With reference to the history of the Italian state entrepreneurship, this case may be paradigmatic of the advent of a new era, characterized by partially privatized enterprises in sectors considered strategic which are successful in the international arena (Finmeccanica, ENI). The article shows that the aeronautics, space and electronics divisions began in the 1950s and as a result of their technological characteristics were kept relatively free from political interference, with a strong propensity to pursue internationalization and thus competitiveness. The conclusion is that, under certain conditions, state ownership may result effective in ensuring not only adequate financial resources, but also a proper managerial governance.
Human neural stem cells: a model system for the study of Lesch–Nyhan disease neurological aspects
Authors: Cristini Silvia , Navone Stefania , Canzi Laura , Acerbi Francesco , Ciusani Emilio , Hladnik Uros , de Gemmis Paola , Alessandri Giulio , Colombo Augusto , Parati Eugenio , Invernici Gloria
Published: February 2010

The study of Lesch–Nyhan-diseased (LND) human brain is crucial for understanding how mutant hypoxanthine-phosphoribosyltransferase (HPRT) might lead to neuronal dysfunction. Since LND is a rare, inherited disorder caused by a deficiency of the enzyme HPRT, human neural stem cells (hNSCs) that carry this mutation are a precious source for delineating the consequences of HPRT deficiency and for developing new treatments. In our study we have examined the effect of HPRT deficiency on the differentiation of neurons in hNSCs isolated from human LND fetal brain. We have examined the expression of a number of transcription factors essential for neuronal differentiation and marker genes involved in dopamine (DA) biosynthetic pathway. LND hNSCs demonstrate aberrant expression of several transcription factors and DA markers. HPRT-deficient dopaminergic neurons also demonstrate a striking deficit in neurite outgrowth. These results represent direct experimental evidence for aberrant neurogenesis in LND hNSCs and suggest developmental roles for other housekeeping genes in neurodevelopmental disease. Moreover, exposure of the LND hNSCs to retinoic acid medium elicited the generation of dopaminergic neurons. The lack of precise understanding of the neurological dysfunction in LND has precluded development of useful therapies. These results evidence aberrant neurogenesis in LND hNSCs and suggest a role for HPRT gene in neurodevelopment. These cells combine the peculiarity of a neurodevelopmental model and a human, neural origin to provide an important tool to investigate the pathophysiology of HPRT deficiency and more broadly demonstrate the utility of human neural stem cells for studying the disease and identifying potential therapeutics.
First Report of Leaf Smut of Tomatillo Caused by Entyloma austral
Authors: Koike Steven T. , Glawe Dean A. , Barlow Tess
Published: February 2010

The causal agent was identified as Entyloma australe Speg. based on host and on pathogen morphology and ITS region sequence. The size, shape, and color of teliospores and the production of fascicles of conidiophores fit the descriptions for E. australe. This appears to be the only Entyloma species occurring on Physalis. This report appears to be the first record of E. australe on P. philadelphica.

Accepted for publication 11 November 2009. Published 16 February 2010.
Role of Transient Receptor Potential and Acid-sensing Ion Channels in Peripheral Inflammatory Pain
Authors: White John P. M. , Cibelli Mario , Rei Fidalgo Antonio , Paule Cleoper C. , Noormohamed Faruq , Urban Laszlo , Maze Mervyn , Nagy Istvan
Published: February 2010

Pain originating in inflammation is the most common pathologic pain condition encountered by the anesthesiologist whether in the context of surgery, its aftermath, or in the practice of pain medicine. Inflammatory agents, released as components of the body's response to peripheral tissue damage or disease, are now known to be collectively capable of activating transient receptor potential vanilloid type 1, transient receptor potential vanilloid type 4, transient receptor potential ankyrin type 1, and acid-sensing ion channels, whereas individual agents may activate only certain of these ion channels. These ionotropic receptors serve many physiologic functions-as, indeed, do many of the inflammagens released in the inflammatory process. Here, we introduce the reader to the role of these ionotropic receptors in mediating peripheral pain in response to inflammation.
Endothelial Dysfunction Enhances Vasoconstriction Due to Scavenging of Nitric Oxide by a Hemoglobin-based Oxygen Carrier
Authors: Yu Binglan , Shahid Mohd , Egorina Elena M. , Sovershaev Mikhail A. , Raher Michael J. , Lei Chong , Wu Mei X. , Bloch Kenneth D. , Zapol Warren M.
Published: February 2010

Background

To date, there is no safe and effective hemoglobin-based oxygen carrier (HBOC) to substitute for erythrocyte transfusion. It is uncertain whether a deficiency of endothelial nitric oxide bioavailability (endothelial dysfunction) prevents or augments HBOC-induced vasoconstriction.

Methods

Hemodynamic effects of infusion of PolyHeme (1.08 g hemoglobin/kg; Northfield Laboratories, Evanston, IL) or murine tetrameric hemoglobin (0.48 g hemoglobin/kg) were determined in awake healthy lambs, awake mice, and anesthetized mice. In vitro, a cumulative dose-tension response was obtained by sequential addition of PolyHeme or tetrameric hemoglobin to phenylephrine-precontracted murine aortic rings.

Results

Infusion of PolyHeme did not cause systemic hypertension in awake lambs but produced acute systemic and pulmonary vasoconstriction. Infusion of PolyHeme did not cause systemic hypertension in healthy wild-type mice but induced severe systemic vasoconstriction in mice with endothelial dysfunction (either db/db mice or high-fat fed wild-type mice for 4-6 weeks). The db/db mice were more sensitive to systemic vasoconstriction than wild-type mice after the infusion of either tetrameric hemoglobin or PolyHeme. Murine aortic ring studies confirmed that db/db mice have an impaired response to an endothelial-dependent vasodilator and an enhanced vasoconstrictor response to HBOC.

Conclusions

Reduction in low molecular weight hemoglobin concentrations to less than 1% is insufficient to abrogate the vasoconstrictor effects of HBOC infusion in healthy awake sheep or in mice with reduced vascular nitric oxide levels associated with endothelial dysfunction. These findings suggest that testing HBOCs in animals with endothelial dysfunction can provide a more sensitive indication of their potential vasoconstrictor effects.
Volatile Anesthetics Rapidly Increase Dendritic Spine Density in the Rat Medial Prefrontal Cortex during Synaptogenesis
Authors: Briner Adrian , De Roo Mathias , Dayer Alexandre , Muller Dominique , Habre Walid , Vutskits Laszlo
Published: February 2010

Background

Recent experimental observations suggest that, in addition to induce neuroapoptosis, anesthetics can also interfere with synaptogenesis during brain development. The aim of this study was to pursue this issue by evaluating the exposure time-dependent effects of volatile anesthetics on neuronal cytoarchitecture in 16-day-old rats, a developmental stage characterized by intense synaptogenesis in the cerebral cortex.

Methods

Whistar rats underwent isoflurane (1.5%), sevoflurane (2.5%), or desflurane (7%) anesthesia for 30, 60, and 120 min at postnatal day 16, and the effect of these treatments on neuronal cytoarchitecture was evaluated 6 h after the initiation of anesthesia. Cell death was assessed using Fluoro-Jade B staining and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling assay. Ionotophoretic injections into layer 5 pyramidal neurons in the medial prefrontal cortex allowed visualization of dendritic arbor. Tracing of dendritic tree was carried out using the Neurolucida station (Microbrightfield, Williston, VT), whereas dendritic spines were analyzed using confocal microscopy.

Results

Up to a 2-h-long exposure, none of the volatile drugs induced neuronal cell death or significant changes in gross dendritic arbor pattern of layer 5 pyramidal neurons in pups at postnatal day 16. In contrast, these drugs significantly increased dendritic spine density on dendritic shafts of these cells. Importantly, considerable differences were found between these three volatile agents in terms of exposure time-dependent effects on dendritic spine density.

Conclusion

These new results suggest that volatile anesthetics, with different potencies and without inducing cell death, could rapidly interfere with physiologic patterns of synaptogenesis and thus might impair appropriate circuit assembly in the developing cerebral cortex.
Hyperglycemia Adversely Modulates Endothelial Nitric Oxide Synthase during Anesthetic Preconditioning through Tetrahydrobiopterin– and Heat Shock Protein 90–mediated Mechanisms
Authors: Amour Julien , Brzezinska Anna K. , Jager Zachary , Sullivan Corbin , Weihrauch Dorothee , Du Jianhai , Vladic Nikolina , Shi Yang , Warltier David C. , Pratt Phillip F. , Kersten Judy R.
Published: February 2010

Background

Endothelial nitric oxide synthase activity is regulated by (6R-)5,6,7,8-tetrahydrobiopterin (BH4) and heat shock protein 90. The authors tested the hypothesis that hyperglycemia abolishes anesthetic preconditioning (APC) through BH4- and heat shock protein 90-dependent pathways.

Methods

Myocardial infarct size was measured in rabbits in the absence or presence of APC (30 min of isoflurane), with or without hyperglycemia, and in the presence or absence of the BH4 precursor sepiapterin. Isoflurane-dependent nitric oxide production was measured (ozone chemiluminescence) in human coronary artery endothelial cells cultured in normal (5.5 mm) or high (20 mm) glucose conditions, with or without sepiapterin (10 or 100 microm).

Results

APC decreased myocardial infarct size compared with control experiments (26 +/- 6% vs. 46 +/- 3%, respectively; P < 0.05), and this action was blocked by hyperglycemia (43 +/- 4%). Sepiapterin alone had no effect on infarct size (46 +/- 3%) but restored APC during hyperglycemia (21 +/- 3%). The beneficial actions of sepiapterin to restore APC were blocked by the nitric oxide synthase inhibitor N (G)-nitro-L-arginine methyl ester (47 +/- 2%) and the BH4 synthesis inhibitor N-acetylserotonin (46 +/- 3%). Isoflurane increased nitric oxide production to 177 +/- 13% of baseline, and this action was attenuated by high glucose concentrations (125 +/- 6%). Isoflurane increased, whereas high glucose attenuated intracellular BH4/7,8-dihydrobiopterin (BH2) (high performance liquid chromatography), heat shock protein 90-endothelial nitric oxide synthase colocalization (confocal microscopy) and endothelial nitric oxide synthase activation (immunoblotting). Sepiapterin increased BH4/BH2 and dose-dependently restored nitric oxide production during hyperglycemic conditions (149 +/- 12% and 175 +/- 9%; 10 and 100 microm, respectively).

Conclusion

The results indicate that tetrahydrobiopterin and heat shock protein 90-regulated endothelial nitric oxide synthase activity play a central role in cardioprotection that is favorably modulated by volatile anesthetics and dysregulated by hyperglycemia. Enhancing the production of BH4 may represent a potential therapeutic strategy.
Relation between Preoperative and Intraoperative New Wall Motion Abnormalities in Vascular Surgery Patients
Authors: Galal Wael , Hoeks Sanne E. , Flu Willem Jan , van Kuijk Jan Peter , Goei Dustin , Galema Tjebbe , den Uil Corstiaan , van Gestel Yvette R. B. M. , Bax Jeroen J. , Verhagen Hence J. M. , Poldermans Don
Published: February 2010

Background

Coronary revascularization of the suspected culprit coronary lesion assessed by preoperative stress testing is not associated with improved outcome in vascular surgery patients.

Methods

Fifty-four major vascular surgery patients underwent preoperative dobutamine echocardiography and intraoperative transesophageal echocardiography. The locations of left ventricular rest wall motion abnormalities and new wall motion abnormalities (NWMAs) were scored using a seven-wall model. During 30-day follow-up, postoperative cardiac troponin release, myocardial infarction, and cardiac death were noted.

Results

Rest wall motion abnormalities were noted by dobutamine echocardiography in 17 patients (31%), and transesophageal echocardiography was noted in 16 (30%). NWMAs were induced during dobutamine echocardiography in 17 patients (31%), whereas NWMAs were observed by transesophageal echocardiography in 23 (43%), kappa value = 0.65. Although preoperative and intraoperative rest wall motion abnormalities showed an excellent agreement for the location (kappa value = 0.92), the agreement for preoperative and intraoperative NWMAs in different locations was poor (kappa value = 0.26-0.44). The composite cardiac endpoint occurred in 14 patients (26%).

Conclusions

There was a poor correlation between the locations of preoperatively assessed stress-induced NWMAs by dobutamine echocardiography and those observed intraoperatively using transesophageal echocardiography. However, the composite endpoint of outcome was met more frequently in relation with intraoperative NWMAs.
Use of Manometry for Laryngeal Mask Airway Reduces Postoperative Pharyngolaryngeal Adverse Events
Authors: Seet Edwin , Yousaf Farhanah , Gupta Smita , Subramanyam Rajeev , Wong David T. , Chung Frances
Published: February 2010

Background

Adverse events such as pharyngolaryngeal complications are indicators of quality patient care. Use of manometry to limit the laryngeal mask airway (LMA) intracuff pressure is not currently a routine practice. This double-blind randomized trial compared pharyngolaryngeal complications in patients managed with manometers to limit the LMA intracuff pressure (<44 mmHg) with patients under routine care.

Method

Two hundred consenting patients who underwent ambulatory surgery were randomly allocated to pressure-limiting and routine care groups. Anesthesia was induced with propofol and fentanyl, and maintained with desflurane in air-oxygen. An LMA was inserted, and the cuff was inflated as per usual practice. The patients breathed spontaneously. Research assistants measured the LMA intracuff pressure. In the pressure-limiting group, LMA intracuff pressure was adjusted to less than 44 mmHg. No intervention was performed in the routine care group. Sore throat, dysphonia, and dysphagia were assessed at 1, 2, and 24 h postoperatively. Composite pharyngolaryngeal complications were compared using chi-square test.

Results

Baseline demographic data were comparable between groups. Mean LMA intracuff pressure was less in the pressure-limiting group versus the routine care group (40 +/- 6 vs. 114 +/- 57 mmHg, P < 0.001). The incidence of composite pharyngolaryngeal complications was significantly lower in the pressure-limiting group versus the routine care group (13.4 vs. 45.6%, P < 0.001), with a relative risk reduction of 70.6%, and a number needed to treat of three (95% CI 2.2-7.5).

Conclusion

Reduction of LMA intracuff pressure to less than 44 mmHg lowers the incidence of postoperative pharyngolaryngeal complications. The LMA cuff pressures should be measured routinely using manometry, and deflating the intracuff pressure to less than 44 mmHg should be recommended as anesthetic best practice.
Noble Gas Xenon Is a Novel Adenosine Triphosphate-sensitive Potassium Channel Opener
Authors: Bantel Carsten , Maze Mervyn , Trapp Stefan
Published: February 2010

Background

Adenosine triphosphate-sensitive potassium (KATP) channels in brain are involved in neuroprotective mechanisms. Pharmacologic activation of these channels is seen as beneficial, but clinical exploitation by using classic K channel openers is hampered by their inability to cross the blood-brain barrier. This is different with the inhalational anesthetic xenon, which recently has been suggested to activate KATP channels; it partitions freely into the brain.

Methods

To evaluate the type and mechanism of interaction of xenon with neuronal-type KATP channels, these channels, consisting of Kir6.2 pore-forming subunits and sulfonylurea receptor-1 regulatory subunits, were expressed in HEK293 cells and whole cell, and excised patch-clamp recordings were performed.

Results

Xenon, in contrast to classic KATP channel openers, acted directly on the Kir6.2 subunit of the channel. It had no effect on the closely related, adenosine triphosphate (ATP)-regulated Kir1.1 channel and failed to activate an ATP-insensitive mutant version of Kir6.2. Furthermore, concentration-inhibition curves for ATP obtained from inside-out patches in the absence or presence of 80% xenon revealed that xenon reduced the sensitivity of the KATP channel to ATP. This was reflected in an approximately fourfold shift of the concentration causing half-maximal inhibition (IC50) from 26 +/- 4 to 96 +/- 6 microm.

Conclusions

Xenon represents a novel KATP channel opener that increases KATP currents independently of the sulfonylurea receptor-1 subunit by reducing ATP inhibition of the channel. Through this action and by its ability to readily partition across the blood-brain barrier, xenon has considerable potential in clinical settings of neuronal injury, including stroke.
Use of Serotonergic Antidepressants and Bleeding Risk in Orthopedic Patients
Authors: van Haelst Ingrid M. M. , Egberts Toine C. G. , Doodeman Hieronymus J. , Traast Han S. , Burger Bart J. , Kalkman Cor J. , van Klei Wilton A.
Published: February 2010

Background

Selective serotonin reuptake inhibitors have been associated with an increased bleeding tendency. Information on the impact of a possible impaired hemostasis associated with the perioperative use of selective serotonin reuptake inhibitors is limited. This study aimed to determine the association between the perioperative use of selective serotonin reuptake inhibitors and the amount of blood loss during surgery and perioperative transfusion requirements.

Methods

The authors conducted a retrospective cohort study among patients who underwent elective primary total hip arthroplasty in two hospitals from the period of July 1, 2004 until July 1, 2008. The index group included all users of both serotonergic and nonserotonergic antidepressants. The reference group included a random sample (ratio 1:3) of nonusers. The primary outcome was the amount of intraoperative blood loss. The requirement for blood transfusion was a secondary outcome. The outcomes were adjusted for confounding factors (comorbidity and comedication) using regression techniques.

Results

The index group included 66 users of serotonergic and 29 users of nonserotonergic antidepressants, and the reference group included 285 patients. After adjustment for confounding factors, mean blood loss during surgery was significantly higher in the users of selective serotonin reuptake inhibitors when compared with the reference group: 95 ml (95% CI 9-181). Mean blood loss in the users of nonserotonergic antidepressants did not differ from the reference group. Users of antidepressants did not have a higher risk for transfusion.

Conclusions

Patients undergoing total hip arthroplasty who continue the use of serotonergic antidepressants show a significantly higher, but clinically unimportant, intraoperative blood loss, without an increase in perioperative transfusion requirements.
Bumetanide Alleviates Epileptogenic and Neurotoxic Effects of Sevoflurane in Neonatal Rat Brain
Authors: Edwards David A. , Shah Hina P. , Cao Wengang , Gravenstein Nikolaus , Seubert Christoph N. , Martynyuk Anatoly E.
Published: February 2010

Background

We tested the hypothesis that in newborn rats, sevoflurane may cause seizures, neurotoxicity, and impairment in synaptic plasticity-effects that may be diminished by the Na-K-2Cl cotransporter 1 inhibitor, bumetanide.

Methods

Electroencephalography, activated caspase-3, and hippocampal long-term potentiation were measured in rats exposed to 2.1% sevoflurane for 0.5-6 h at postnatal days 4-17 (P4-P17).

Results

Arterial blood gas samples drawn at a sevoflurane concentration of 2.1% showed no evidence of either hypoxia or hypoventilation in spontaneously breathing rats. Higher doses of sevoflurane (e.g., 2.9%) caused respiratory depression. During anesthesia maintenance, the electroencephalography exhibited distinctive episodes of epileptic seizures in 40% of P4-P8 rats. Such seizure-like activity was not detected during anesthesia maintenance in P10-P17 rats. Emergence from 3 h of anesthesia with sevoflurane resulted in tonic/clonic seizures in some P10-P17 rats but not in P4-P8 rats. Bumetanide (5 micromol/kg, intraperitoneally) significantly decreased seizures in P4-P9 rats but did not affect the emergence seizures in P10-P17 rats. Anesthesia of P4 rats with sevoflurane for 6 h caused a significant increase in activated caspase-3 and impairment of long-term potentiation induction measured at 1 and 14-17 days after exposure to sevoflurane, respectively. Pretreatment of P4 rats with bumetanide nearly abolished the increase in activated caspase-3 but did not alleviate impairment of long-term potentiation.

Conclusion

These results support the possibility that excitatory output of sevoflurane-potentiated gamma-aminobutyric acid type A/glycine systems may contribute to epileptogenic and neurotoxic effects in early postnatal rats.
Excited-state molecular structures captured by X-ray transient absorption spectroscopy: a decade and beyond
Authors: Chen Lin X. , Zhang Xiaoyi , Lockard Jenny V. , Stickrath Andrew B. , Attenkofer Klaus , Jennings Guy , Liu Di-Jia
Published: February 2010

Transient molecular structures along chemical reaction pathways are important for predicting molecular reactivity, understanding reaction mechanisms, as well as controlling reaction pathways. During the past decade, X-ray transient absorption spectroscopy (XTA, or LITR-XAS, laser-initiated X-ray absorption spectroscopy), analogous to the commonly used optical transient absorption spectroscopy, has been developed. XTA uses a laser pulse to trigger a fundamental chemical process, and an X-ray pulse(s) to probe transient structures as a function of the time delay between the pump and probe pulses. Using X-ray pulses with high photon flux from synchrotron sources, transient electronic and molecular structures of metal complexes have been studied in disordered media from homogeneous solutions to heterogeneous solution–solid interfaces. Several examples from the studies at the Advanced Photon Source in Argonne National Laboratory are summarized, including excited-state metalloporphyrins, metal-to-ligand charge transfer (MLCT) states of transition metal complexes, and charge transfer states of metal complexes at the interface with semiconductor nanoparticles. Recent developments of the method are briefly described followed by a future prospective of XTA. It is envisioned that concurrent developments in X-ray free-electron lasers and synchrotron X-ray facilities as well as other table-top laser-driven femtosecond X-ray sources will make many breakthroughs and realise dreams of visualizing molecular movies and snapshots, which ultimately enable chemical reaction pathways to be controlled.
Liquid–solid suspension theory with reference to possible applications in geology
Authors: Di Felice Renzo
Published: February 2010

The first part of this paper provides an overview of the state of the art of the hydrodynamics of liquid suspensions of solid particles. It is shown that knowledge of the suspension Archimedes number is sufficient to estimate the voidage–velocity parameters for suspensions of solids possessing homogenous characteristics, thereby completely defining the system from a fluid dynamic point of view. A general relation is presented which will indicate if a solid–fluid system will be in the fixed or in the suspended state depending on the relative velocity between the two phases. Modifications of the previous approach when the solid particles are not spherical have been also indicated. The basic features of the pseudo‐fluid approach are then presented. This approach is useful when the solids making up the suspension have different sizes: by the introduction of the pseudo‐fluid apparent characteristics (density and viscosity) it is possible to make basic estimations of the suspension behaviour. The second part of the paper outlines possible application of suspension theory to geological phenomena, such as the vertical transport of water–sand suspensions. Aspects of interest are the minimum pressure required for the transport of the suspension, the estimation of suspension flow rate through an overall pressure balance, the vertical transport of large ‘breccia’ blocks and the behaviour of the solid particles present in the rising conduit once the overpressure falls below the minimum value needed to sustain the flow. Finally, a warning is given on the limitations of the presented relationships (e.g. the assumption of homogeneous solid dispersion in the suspension) and on situations such as inclined conduits which require a different approach.
Exercise capacity and haemodynamics in patients with sickle cell disease with pulmonary hypertension treated with bosentan: results of the ASSET studies
Authors: Barst Robyn J. , Mubarak Kamal K. , Machado Roberto F. , Ataga Kenneth I. , Benza Raymond L. , Castro Oswaldo , Naeije Robert , Sood Namita , Swerdlow Paul S. , Hildesheim Mariana , Gladwin Mark T. ,   on behalf of the ASSET study group
Published: February 2010

Doppler‐defined pulmonary hypertension (PH) in sickle cell disease (SCD) is associated with 40% mortality at 40 months. To assess the effect of bosentan in SCD‐PH, two randomized, double‐blind, placebo‐controlled, 16‐week studies were initiated. Safety concerns are particularly relevant in SCD due to comorbid conditions. ASSET‐1 and ‐2 enrolled patients with pulmonary arterial hypertension (PAH) and pulmonary venous hypertension (PH), respectively. Haemodynamics and 6‐min walk distance (6MWD) were obtained at baseline and week 16. The studies were terminated due to slow site initiation and patient enrolment (n = 26). Bosentan appeared to be well tolerated. Although sample sizes were limited, in ASSET‐1 at baseline, 6MWD correlated with cardiac output (CO; P = 0·006) with non‐significant inverse correlations between 6MWD and pulmonary vascular resistance (PVR; P = 0·07) and between 6MWD and right atrial pressure (P = 0·08). In ASSET‐2 at baseline, there was a non‐significant correlation between 6MWD and CO (P = 0·06). Due to limited sample sizes, efficacy endpoints were not analysed. However, in both studies, non‐significant increases in CO were observed with bosentan compared to placebo. Similarly, non‐significant decreases in PVR were observed with bosentan. Limited data in SCD‐PH suggest that a low 6MWD predicts a low CO. Standard‐dose bosentan appears to be well tolerated. Further investigation is warranted. Clinicaltrials.gov registration numbers NCT00310830, NCT00313196, NCT00360087.
What drives retrogressive succession? Plant strategies to tolerate infertile and poorly drained soils
Authors: Gaxiola Aurora , McNeill Stephen M. , Coomes David A.
Published: February 2010

1. During retrogressive succession, vegetation shifts from taller forests with higher species richness to shorter woody communities of lower diversity. Studies of soil chronosequences have emphasized the role of phosphorus (P) depletion in driving these changes in community structure and composition, but neglected the possible role of poor drainage which is often associated with the oldest sites.

2. We used a fully factorial pot experiment to investigate the effects of soil water conditions and P availability on seedling relative growth rate and survival of 11 woody species associated with a 290 000‐year chronosequence in southern New Zealand. Species were chosen to represent three stages of the chronosequence: young P‐rich soils; intermediate‐age P‐depleted soils; and old P‐depleted, waterlogged soils. Plants were grown in soils taken from youngest and oldest sites of the chronosequence; half the pots were freely drained whilst the other half were waterlogged.

3. Species associated with intermediate‐age soils were typical ‘stress‐tolerators’; those of the youngest and oldest sites were faster growing and more responsive to nutrient availability. Only the latter showed tolerance of waterlogging. Specific root length and adventitious‐root production were important determinants of species’ responses to soil water conditions and nutrient supply.

4. Our study highlights that soil waterlogging and P depletion interact to influence relative growth rate and survival; P depletion is not the sole driver of ecosystem changes in the retrogressive stages of the soil chronosequence. We also show that some species associated with our retrogression did not necessarily conform to conventional views on ‘stress‐tolerance’, but were well adapted to poor drainage.
Self‐shading affects allometric scaling in trees
Authors: Duursma Remko A. , Mäkelä Annikki , Reid Douglas E.B. , Jokela Eric J. , Porté Annabel J. , Roberts Scott D.
Published: February 2010

1. Westet al.[Science,284(1999) 1677] derived an optimal body‐size scaling exponent under the assumption that resources are evenly distributed among exchange surfaces, leading to the well‐known ¾ scaling rule. In trees, this implies a volume‐filling branching network (a fractal dimension of 3 for foliage). However, there is evidence that the fractal dimension is less than 3 in trees.

2. Here, we include self‐shading in the derivation of optimal fractal dimensions. With self‐shading, resources are not evenly distributed among leaves because light enters the crown at the surface and is gradually attenuated within the crown. We find that the optimal fractal dimension can take values between 2 and 3, depending on light interception properties and crown size.

3. For a large data set on foliage and woody biomass in gymnosperm trees, we confirm that the fractal dimension of foliage is less than 3, and that it shows a weak dependence on crown size. However, foliage biomass scaled with crown woody biomass with an exponent of 0·78, very close to the theoretical expectation of ¾ scaling. This can be explained by a deviation from the theoretical prediction in the scaling of crown woody biomass and crown length.

4. Overall, these results confirm a deviation from volume filling in gymnosperm trees, and we provide an explanation for this deviation in terms of optimal metabolic scaling. Because ¾ scaling of foliage biomass is still approximately valid, this implies that metabolic scaling exponents may not be as tightly linked to the fractal dimension of foliage as previously assumed.
Review of triage reform: the case for national consensus on a single triage scale for clients with a mental illness in Australian emergency departments
Authors: Broadbent Marc , Creaton Anne , Moxham Lorna , Dwyer Trudy
Published: February 2010

Aims and objectives.  The aim of this paper is to examine the use of mental health triage scales in Australian emergency departments (EDs) and to explore the use of the Australasian Triage Scale (ATS) with existing mental health triage scales.

Background.  Since the introduction of mainstreaming and deinstitutionalisation in Australian mental health care, the number of clients presenting to Australian EDs has been increasing. It has become apparent that the lack of mental health descriptors in existing triage scales diminishes the ability of ED triage staff to accurately assess clients with a mental illness. In response to this, specialised mental health triage scales have been developed and introduced into practice. Concurrently, mental health descriptors have been incorporated into the ATS used across Australian EDs.

Design.  A review of English language literature was conducted.

Method.  The data bases Proquest, Synergy and CINAHL were searched using the key words ‘emergency department’, ‘triage’, ‘mental health’ and again using the term ‘emergency mental health triage’.

Results.  There is a paucity of literature surrounding the use of mental health triage scales in Australian EDs; 18 articles were found to be directly relevant to the subject matter.

Conclusion.  Currently clients with a mental illness presenting to the ED may be triaged against one of four mental health triage scales. Research has shown that the mental health descriptors in the ATS are not as reliable as a specialised mental health triage scale.

Relevance to clinical practice.  This has implications for clinical practice on two levels. First, it affects the initial triage assessment in the ED and the ability for mental health clinicians to respond in a timely manner and this will have an impact on clinical outcomes. Second, the use of the mental health triage criteria in the ATS may misrepresent ED workloads and affect data pertaining to ED performance.
Addressing health literacy: the experiences of undergraduate nursing students
Authors: Scheckel Martha , Emery Nicole , Nosek Catherine
Published: February 2010

Aims and objectives.  To describe undergraduate nursing students’ experiences of learning and providing patient education.

Background.  To teach nursing students principles and practices of patient education, nurse educators design instructional strategies using educational and clinical practice guidelines, research and theories. This means teachers’ approaches to teaching patient education are derived from evidence and support the evidence‐based teaching movement. Despite their efforts, research shows that students lack knowledge and skills needed for proficiency in providing patient education. However, this research does not explicate students’ experiences of learning and providing patient education, which can inform teachers of ways to structure approaches to teaching students this nursing practice.

Design.  The philosophical background for this study was interpretive phenomenology.

Methods.  Eight undergraduate nursing students in their final semester of a baccalaureate nursing programme were interviewed using face‐to‐face, unstructured interviews. Data were collected using unstructured interviews and analysed using hermeneutics.

Results.  Common meanings from the analysis of data shows that a primary practice of students’ learning and providing patient education is addressing health literacy. Three sub‐themes: (1) respecting languages: learning persistence (2) helping patients understand: learning to teach and (3) promoting engagement: learning sensitivity, exemplify how students are addressing health literacy.

Conclusions.  Contrary to literature on students’ lack of proficiency in providing patient education, the findings of this study reveal extraordinary competencies students already have in addressing health literacy. The results of this study show the paramount need for teachers to design instructional strategies that deepen students’ extant knowledge and skills in health literacy prior to graduation from nursing programmes.

Relevance to clinical practice.  Using the findings of this study, teachers will gain novel approaches to teaching patient education that specifically target instructing students in the practices of health literacy. These practices can ameliorate and mitigate problems many students encounter when addressing health literacy.
Well‐being in patients and relatives after open‐heart surgery from the perspective of health care professionals
Authors: Karlsson Ann‐Kristin , Mattsson Bengt , Johansson Mats , Lidell Evy
Published: February 2010

Aim.  The aim of this study was to explore how health care professionals perceive the well‐being of patients and relatives following open‐heart surgery.

Background.  Open‐heart surgery is an extraordinary life event associated with hope and fear among both patients and relatives, thus they require attention from health care professionals. Patients’ short stay in hospital after surgery and the workload of health care professionals increase the risk that reduced well‐being will be overlooked. Health care professionals need to become familiar with the signs of reduced well‐being.

Design.  The study has an observational design and was performed using a qualitative method.

Method.  Health care professionals working with patients who have undergone open‐heart surgery participated in focus group discussions. The data were analysed by means of content analysis.

Results.  Two categories emerged: signs of vulnerability and signs of insecurity. The latent meaning of the study was interpreted as awareness of an exposed position.

Conclusion.  The health care professionals were aware of patients’ and relatives’ exposed position following open‐heart surgery. Reduced well‐being was communicated by bodily and emotional signs, which were captured using direct communication or intuition.

Relevance to clinical practice.  Developing the ability to recognise signs of reduced well‐being is important for minimising the negative influences associated with open‐heart surgery for patients and relatives. Increased awareness that both anger and avoidance can mask depression is important. Patients and their relatives, particularly younger ones, should be observed to ensure early detection of a life crisis provoked by the heart disease. Furthermore, staff should invite patients and their partners to talk about sexuality. Changes aimed at increasing patients’ and relatives’ well‐being would be facilitated by interdisciplinary teamwork, ‘reflection groups’ for a greater exchange of knowledge and the implementation of a patient/family perspective. The latter would lead to greater interest in the relatives’ situation and position in cardiac care.
Clinical teachers’ approaches to nursing
Authors: Forbes Helen
Published: February 2010

Aims and objectives.  The aim of the study was to investigate clinical teachers’ experiences of nursing and clinical teaching of undergraduate university students. This article reports on clinical teachers’ approaches to nursing, which is one part of that study.

Background.  A lack of knowledge and understanding exists about how clinical teachers approach nursing. There is a likely relationship between approaches to nursing and what is focused on when teaching undergraduate nursing students in the clinical setting. It is therefore important to understand the variation in how clinical teachers approach nursing.

Design.  Phenomenography.

Method.  Semi‐structured interviews of 20 practicing nurses currently employed as clinical teachers from a range of Australian universities were conducted. Data were analysed using a phenomenographic approach.

Results.  Key aspects of variation in clinical teacher approaches to nursing were identified. The results suggest that clinical teachers approach nursing in one of two ways, either a patient‐focused approach or a nurse‐focused approach. The research findings extend knowledge that will assist with preparation and support of clinical teachers.

Conclusion.  Knowledge of the different approaches to nursing provides a structure for helping clinical teachers increase their awareness of both their approach to nursing and the implications for their nursing and teaching.

Relevance to clinical practice.  Awareness of complex approaches to nursing may be required for multidisciplinary care.
Correlates of smoking among adolescents with asthma
Authors: Guo Su‐Er , Ratner Pamela A , Johnson Joy L , Okoli Chizimuzo TC , Hossain Shahadut
Published: February 2010

Aims and objective.  This study examined the correlates of smoking among asthmatic adolescents to gain a better understanding of who is at particular risk.

Background.  Smoking is especially harmful to individuals with asthma. However, smoking is surprisingly prevalent among asthmatic individuals, with prevalence rates similar to or higher than those of the general adult or adolescent populations. Despite this notable finding, there has been little research about factors (i.e. biophysical, psychosocial and behavioural) influencing asthmatic adolescents’ tobacco use patterns.

Design.  A Canadian provincial cross‐sectional survey.

Method.  The study about adolescents’ tobacco use and health status was conducted in secondary schools in 2004, 608 asthmatic adolescents participated. Demographic factors, biophysical (body mass index and physical health), psychosocial factors (parents’ and peers’ smoking, environmental tobacco smoke exposure and depression) and behavioural factors (marijuana use, alcohol use and exercise frequency) were explored. Multinomial logistic regression analyses were conducted to identify risk factors associated with tobacco use.

Results and conclusions.  Of the 608 asthmatic adolescents, 17·4% currently smoked and 12·0% formerly smoked. Girls, compared with boys, were more likely to smoke (OR: 3·34, 95% CI: 1·62–6·96) after adjusting for differences in the other demographic, biophysical, psychosocial and behavioural factors. Asthmatic girls who had relatively higher body mass index, were in the higher school grades, used marijuana or alcohol, had minor to severe depressive symptoms, had environmental tobacco smoke exposure in their homes and had friends who smoked or were currently more likely to smoke. The former smokers had similar risk factors including higher body mass index, environmental tobacco smoke exposure at home, friends who smoked and marijuana use.

Relevance to clinical practice.  Despite their health condition, asthmatic adolescents continue currently or formerly to smoke. Gender appropriate prevention and cessation interventions for asthmatic adolescents may need to address important psychosocial and environmental factors that increase the risk of these adolescents initiating and maintaining tobacco use.
Implementing and standardising the use of peripheral vascular access devices
Authors: Easterlow Dean , Hoddinott Phill , Harrison Stephanie
Published: February 2010

Aims and objectives.  To assess the impact of a change initiative relating to the use of peripheral intravenous cannulae on healthcare‐acquired infections in an acute hospital trust in London, UK.

Background.  The prevalence of healthcare‐acquired infections has increased in the UK in recent years. Causal factors include poor practice and declining standards of cleanliness and hygiene in healthcare settings.

Design.  Implementation of a change management initiative.

Methods.  A baseline audit was conducted to identify areas for change. Based on the audit findings, a change initiative was implemented which included the introduction of a new, non‐ported needle‐safe cannula, together with changes in practices relating to peripheral intravenous cannulae care.

Results.  In the eight months postintroduction of the new cannulae, decreases of 53% and 35% were reported in the number of methicillin‐resistant Staphylococcus aureus and healthcare‐acquired infection cases, respectively, compared with the same period prior to implementation. Audits results also demonstrated considerable improvements in practices relating to cannula care following implementation of the change initiative.

Conclusions.  A change in culture, the adoption of a non‐ported cannula and improvements in practices relating to peripheral intravenous cannulae care led to significant reductions in healthcare‐acquired infections during the period of the study.

Relevance to clinical practice.  The adoption of appropriate cannulae and administration sets to minimise infection risk can help to reduce the incidence of methicillin‐resistant S. aureus and healthcare‐acquired infection cases resulting from peripheral venous cannulation. Training and support to encourage the adoption of best practice, in conjunction with regular follow‐up audits, can lead to a reduction in infection rates and general improvements in the quality of peripheral line care. The findings of this study provide similar institutions with evidence to guide decision‐making on cannula care.