bluuebunny/crossref_metadata_2025 huggingface dataset:
An essential function of sphingolipids in yeast cell division
Authors: Epstein Sharon , Castillon Guillaume A. , Qin Yongmei , Riezman Howard
Published: May 2012

Ceramides are bioactive lipids and precursors to sphingolipids. They have been shown to take part in a wide variety of different physiological processes in eukaryotic organisms and are thought to be toxic at high concentrations. Ceramide is synthesized by condensation of the sphingoid base sphinganine and a fatty acyl CoA by ceramide synthases, a family of enzymes that differ in their specificity for the length of the acyl CoA substrate. We have engineered a yeast strain where the endogenous ceramide synthase has been replaced by one of the putative enzymes from cotton. As a result, the yeast strain produces C18 rather than C26 ceramides showing that the cotton protein is a bona fide ceramide synthase with specificity towards C18 acyl CoA. Strikingly, the accumulation of C18 ceramide is not toxic in Saccharomyces cerevisiae. This allows survival of the yeast after deletion of the normally essential AUR1 (inositol phosphorylceramide synthase) gene permitting us to address the essential roles of sphingolipids. Deletion of AUR1 allows cell growth, but leads to a defect in cytokinesis, which takes twice as long as in wild‐type strains. Nuclear division and recruitment of septins is apparently not affected, but cytokinesis is delayed and cell separation is incomplete.
Validation and implications of an energy‐based bedload transport equation
Authors: GAO PENG
Published: May 2012

A recently developed bedload equation (Abrahams & Gao, 2006) has the form ib = ωG3˙4, where ib is the immersed bedload transport rate, ω is the stream power per unit area, G = 1−θc/θ, θ is the dimensionless shear stress and θc is the associated threshold value for the incipient motion of bed grains. This equation has a parsimonious form and provides good predictions of transport rate in both the saltation and sheetflow regimes (i.e. flows with low and high θ values, respectively). In this study, the equation was validated using data independent of those used for developing it. The data represent bedload of identical sizes transported in various steady, uniform, fully rough and turbulent flows over plane, mobile beds. The equation predicted ib quite well over five orders of magnitude. This equation was further compared with six classic bedload equations and showed the best performance. Its theoretical significance was subsequently examined in two ways. First, based on collision theory, the parameter G was related to the ratio of grain‐to‐grain collisions to the total collisions including both grain‐to‐grain and grain‐to‐bed collisions, Pg by Pg = G2, suggesting that G characterizes the dynamic processes of bedload transport from the perspective of granular flow, which partly accounts for the good performance of the equation. Moreover, examining the ability of two common equations to predict bedload in gravel‐bed rivers revealed that G can also be used to simplify equations for predicting transport capacities in such rivers. Second, a simple dimensionless form of the equation was created by introducing B = ib/ω. The theoretical nature of the term B was subsequently revealed by comparing this equation with both the Bagnold model and two commonly used parameters representing dimensionless bedload transport rates.
Bronchoalveolar lavage fluid exosomes contribute to cytokine and leukotriene production in allergic asthma
Authors: Torregrosa Paredes P. , Esser J. , Admyre C. , Nord M. , Rahman Q. K. , Lukic A. , Rådmark O. , Grönneberg R. , Grunewald J. , Eklund A. , Scheynius A. , Gabrielsson S.
Published: May 2012

Background

Leukotrienes (LTs) are potent pro‐inflammatory mediators involved in asthma. Exosomes, nanosized vesicles released from various cells, can stimulate or down‐regulate immune responses, depending on the state and nature of the originating cell. We have recently shown an altered exosome profile in bronchoalveolar lavage fluid (BALF) of patients with sarcoidosis, but their role in asthma is unknown. Our aims were to investigate whether exosomes from BALF have LT biosynthetic capacity and to explore phenotypic and functional characteristics of BALF exosomes in asthma.

Methods

Bronchoalveolar lavage fluid exosomes were collected from healthy individuals (n = 13) and patients with mild allergic asthma to birch pollen (n = 12) before and after birch allergen provocation. Exosomes were characterized by flow cytometry and Western blot. Their capacity to induce IL‐8 and LT production in the human bronchial epithelial cell (BEC) line 16HB14o‐ was measured by ELISA and reverse‐phase HPLC, respectively.

Results

Compared to BALF exosomes from healthy individuals, BALF exosomes from asthmatics displayed higher levels of exosome‐associated markers, such as the tetraspanins CD63 and CD81 and the scavenger receptor CD36. No major differences were observed between BALF exosomes from before and after allergen provocation. Furthermore, we show that BALF exosomes contain enzymes for LT biosynthesis. The effect of exosomes to promote LTC4 and IL‐8 release in BEC was significantly increased for exosomes from asthmatics, and the CysLT1 receptor antagonist Montelukast reduced exosome‐induced IL‐8 secretion.

Conclusions

Bronchoalveolar lavage fluid exosomes from asthmatic and healthy individuals exhibit distinct phenotypes and functions. BALF exosomes from asthmatics might contribute to subclinical inflammation by increasing cytokine and LTC4 generation in airway epithelium.
Streamlining the medication process improves safety in the intensive care unit
Authors: BENOIT E. , ECKERT P. , THEYTAZ C. , JORIS‐FRASSEREN M. , FAOUZI M. , BENEY J.
Published: May 2012

Background

Multiple interventions were made to optimize the medication process in our intensive care unit (ICU). 1 Transcriptions from the medical order form to the administration plan were eliminated by merging both into a single document; 2 the new form was built in a logical sequence and was highly structured to promote completeness and standardization of information; 3 frequently used drug names, approved units, and fixed routes were pre‐printed; 4 physicians and nurses were trained with regard to the correct use of the new form. This study was aimed at evaluating the impact of these interventions on clinically significant types of medication errors.

Methods

Eight types of medication errors were measured by a prospective chart review before and after the interventions in the ICU of a public tertiary care hospital. We used an interrupted time‐series design to control the secular trends.

Results

Over 85 days, 9298 lines of drug prescription and/or administration to 294 patients, corresponding to 754 patient‐days were collected and analysed for the three series before and three series following the intervention. Global error rate decreased from 4.95 to 2.14% (−56.8%, P < 0.001).

Conclusions

The safety of the medication process in our ICU was improved by simple and inexpensive interventions. In addition to the optimization of the prescription writing process, the documentation of intravenous preparation, and the scheduling of administration, the elimination of the transcription in combination with the training of users contributed to reducing errors and carried an interesting potential to increase safety.
Post‐conditioning by xenon reduces ischaemia‐reperfusion injury of the spinal cord in rats
Authors: YANG Y. W. , LU J. K. , QING E. M. , DONG X. H. , WANG C. B. , ZHANG J. , ZHAO L. Y. , GAO Z. F. , CHENG W. P.
Published: May 2012

Background

The neuroprotective effects of xenon post‐conditioning following spinal cord injury remain unknown. We monitored the effect of xenon post‐conditioning on the spinal cord following ischaemia‐reperfusion injury and determined its mechanism of action.

Methods

Spinal cord ischaemia was induced following balloon occlusion of the thoracic aorta in male Sprague‐Dawley rats. Rats were divided into three groups (n = 30 in each group). The control group underwent ischaemia‐reperfusion injury and immediately inhaled 50% (v/v) nitrogen at the time of reperfusion for 60 min continuously. The xenon‐post‐conditioning group underwent the same surgical procedure and immediately inhaled 50% (v/v) xenon at the time of reperfusion for 60 min continuously. The sham operation group underwent the same surgical procedure without aortic catheter occlusion and inhaled the same gas as that in control rats. Neurologic function was assessed using the Basso, Beattie, and Bresnahan score at 4, 24, and 48 h after reperfusion. Histological changes were observed using Nissl staining, the ultrastructure of the spinal cord was examined using transmission electron microscopy, and apoptosis was monitored using terminal deoxynucleotidyl transferase‐mediated deoxyuridine triphosphate nick‐end labelling.

Results

Compared with the control group, the xenon‐post‐conditioning group showed improved neurologic outcomes (11.3 ± 1.6 vs. 15.7 ± 3.1, respectively) and had more morphologically normal neurons (6 ± 2 vs. 12 ± 3) at 48 h after reperfusion. Moreover, apoptotic cell death in xenon‐treated rats was reduced when compared with control rats (18.29 ± 3.06 vs. 27.34 ± 3.63, P < 0.05, respectively).

Conclusions

Xenon post‐conditioning exerts a neuroprotective effect on the spinal cord following ischaemia‐reperfusion injury via its anti‐apoptotic role.
Paediatrician's role in caring for children with learning difficulties
Authors: Roberts Gehan , Price Anna , Oberklaid Frank
Published: May 2012

Aim:  Children with learning difficulties are commonly seen in Australian paediatric outpatient settings. The practice patterns of paediatricians in assessing, referring and managing these children are unknown, and there is no consensus on best practice. We thus aimed to examine the consistency between Australian paediatricians': (i) assessment; (ii) referral; and (iii) management of children presenting with learning difficulties.

Methods:  All 373 paediatrician members of the Australian Paediatric Research Network were invited to participate in an online survey in 2010. Paediatricians who saw children with learning difficulties were asked questions about their assessment, referral and management practices.

Results:  Of 181 (49%) paediatricians to complete the survey, 140 (77%) reported seeing patients with learning difficulties. Most often, paediatricians supplemented their clinical assessments with audiology assessments (75%), teacher or parent questionnaires (60–65%), or teacher contact (51%). Paediatricians used medical investigations (40%), direct assessment tools (27%) or a school visit (4%) less often. Most paediatricians referred children with learning difficulties to educational psychology (84%), special education (61%) or speech therapy (66%) services but less often to occupational therapy (34%) or mental health (15%) services. The most common management strategies were to provide a report to the school (76%) or parents (66%) and to make recommendations around sleep hygiene (75%) and for tutoring (66%).

Conclusions:  Australian paediatric practice in this area is diverse, with the greatest variability around management practices. These data provide a case for designing and implementing evidence‐based guidelines for the paediatric care of children who struggle to learn in school.
Effect and therapeutic mechanisms of tonsillectomy for childhood IgA nephropathy
Authors: NISHI HITOMI , SUGIMOTO KEISUKE , FUJITA SHINSUKE , MIYAZAKI KOHEI , MIYAZAWA TOMOKI , SAKATA NAOKI , OKADA MITSURU , TAKEMURA TSUKASA
Published: May 2012

Aim:  We investigated efficacy and therapeutic mechanisms of tonsillectomy for intractable childhood IgA nephropathy. Five patients refused tonsillectomy. Among 25 patients, 19 patients were able to evaluate histological findings before and after surgery. Patients with poor (n = 7) or relatively poor (n = 18) histologically determined prognosis and an age of at least 7 years, together with proteinuria of at least 0.3 g/day or severe persisting despite ongoing drug treatment, are candidates for surgery. Patients were grouped by interval between diagnosis of IgA nephropathy and tonsillectomy (within 3 years; early group vs 3 years or later; later group). Patients underwent kidney biopsy shortly before and 1 to 2 years after tonsillectomy.

Results:  Proteinuria was reduced after tonsillectomy over 2 years of follow‐up in both early and later groups compared with proteinuria in the 6 months preceding surgery. Complete remission was achieved in 10 patients, most often among those having surgery within 3 years, while patients refusing surgery failed to attain complete remission of urinary findings. Histological activity decreased in both groups, significantly when surgery was early. Complement component C3 deposition and activated macrophages in glomeruli decreased after tonsillectomy, especially with early surgery.

Conclusion:  Tonsillectomy improved clinicopathological features in relatively severe paediatric IgA nephropathy, especially with the early‐surgery group. Therapeutic mechanisms may include inhibition of complement activity in glomeruli and glomerular infiltration by activated macrophages.
Innate immunity to influenza in chronic airways diseases
Authors: HSU ALAN C.‐Y. , SEE HAYLEY V. , HANSBRO PHIL M. , WARK PETER A.B.
Published: May 2012

Influenza presents a unique human infectious disease that has a substantial impact on the public health, in general, and especially for those with chronic airways diseases. People with asthma and chronic obstructive pulmonary disease (COPD) are particularly vulnerable to influenza infection and experience more severe symptoms with the worsening of their pre‐existing conditions. Recent advances in reverse genetics and innate immunity has revealed several influenza virulence factors and host factors involved in influenza pathogenesis and the immune responses to infection. Early innate immunity plays a critical role of limiting viral infection and spread; however, the underlying mechanisms that lead to enhanced susceptibility to influenza infection and severe symptoms in those with asthma and COPD to infection remain un‐investigated. This review will explore the importance of early innate antiviral responses to influenza infection and how these responses are altered by influenza virus and in those with chronic airways diseases.
Repair and regeneration of tracheal surface epithelium and submucosal glands in a mouse model of hypoxic‐ischemic injury
Authors: HEGAB AHMED E. , NICKERSON DEREK W. , HA VI LUAN , DARMAWAN DAPHNE O. , GOMPERTS BRIGITTE N.
Published: May 2012

Background and objective:  The heterotopic syngeneic tracheal transplant mouse model is an acute hypoxic‐ischemic injury model that undergoes complete repair and regeneration. We hypothesized that the repair and regeneration process of the surface epithelium and submucosal glands would occur in a reproducible pattern that could be followed by the expression of specific markers of epithelial cell types.

Methods:  We used the syngeneic heterotopic tracheal transplant model to develop a temporal and spatial map of cellular repair and regeneration by examining the tracheal grafts at post‐transplant days 1, 3, 5, 7, 10 and 14. We used pulsed BrdU and immunofluorescent staining to identify and follow proliferating and repairing cell populations.

Results:  We confirmed the reproducibility of the injury and repair in the model and we found a distinct sequence of reappearance of the various stem/progenitor and differentiated cell populations of the tracheal surface epithelium and submucosal glands. In the initial phase, the basal and duct cells that survived the injury proliferated to re‐epithelialize the basement membrane with K5 and K14 expressing cells. Then these cells proliferated further and differentiated to restore the function of the epithelium. During this repair process, TROP‐2 marked all repairing submucosal gland tubules and ducts. Non‐CCSP‐expressing serous cells were found to differentiate 4–5 days before Clara, mucus and ciliated cells.

Conclusions:  Improving our understanding of the reparative process of the airway epithelium will allow us to identify cell‐specific mechanisms of repair that could be used as novel therapeutic approaches for abnormal repair leading to airway diseases.
Recovery of rain forest soil seed banks under different reforestation pathways in eastern Australia
Authors: Paul Miriam , Catterall Carla P. , Kanowski John , Pollard Peter C.
Published: May 2012

Summary  Seed availability is a major factor limiting the recruitment of rain forest to cleared land, but little is known about the composition of the soil seed bank under different reforestation pathways. We quantified changes in the viable soil seed bank following rain forest clearing and pasture establishment and subsequent reforestation in subtropical eastern Australia. Major reforestation pathways in the region include planting of a diverse suite of native trees for ecological restoration purposes, autogenic regrowth dominated by the non‐native tree Camphor Laurel (Cinnamomum camphora) and management of this regrowth to accelerate the development of a native tree community. These pathways differ considerably in cost: restoration plantings are expensive, autogenic regrowth is free, whilst managing regrowth generally costs much less than restoration plantings. We surveyed five sites within each of three reforestation pathways as well as reference sites in remnant rain forest and pasture. The composition of the seed bank was determined by germinating plants from soil samples collected from each site. Germinants were classified into several functional groups according to life form, origin, dispersal mode and successional stage. The majority of functional groups varied significantly in abundance or richness between rain forest and pasture sites. Most of the functional groups that varied between rain forest and pasture were restored to values similar to rain forest by at least one of the three reforestation pathways examined. The species richness of native woody plants in the soil seed bank was slightly higher in restoration plantings than in autogenic or managed regrowth; nevertheless, the species richness and abundance of native woody plants and vines were higher in the seed bank of autogenic regrowth than pasture, and both attributes were enhanced by the management of regrowth sites. The results of this study show that autogenic regrowth can make an important contribution to rain forest restoration at a landscape scale. The optimal reforestation approach or mix of approaches will depend on the desired rate of recovery and the resources available for restoration.
The Seedling Ratio Method for determining ungulate impacts on forest understoreys: Utility in an Australian ecosystem
Authors: Bennett Ami , Coulson Graeme
Published: May 2012

The Seedling Ratio Method was devised to assess the impacts of introduced ungulates on plant species richness in forest understoreys. The method has successfully assessed ungulate impacts on species richness in forests in New Zealand and Hawaii, which do not have native herbivores. We tested the three critical assumptions that underlie this method to investigate its potential for use in an Australian ecosystem. This study was conducted in the Yarra Ranges National Park (YRNP), Victoria, which had a high‐density population of an introduced deer species, Sambar (Cervus unicolor), in addition to several native herbivore species. One of the three key assumptions of the Seedling Ratio Method was not supported, whereas conventional differential exclosures showed clear and separate impacts by Sambar and native herbivores. We conclude that the Seedling Ratio Method could not provide a clear indication of browsing impact on forest understoreys in YRNP.
Experimental changes in disturbance type do not induce short‐term shifts in plant community structure in three semi‐arid grasslands of the Victorian Riverine Plain managed for nature conservation
Authors: Wong Nathan K. , Morgan John W.
Published: May 2012

Summary  Since the mid 1990s, there has been a significant increase in the area of semi‐arid grasslands included in the National Reserve Systems in the Victorian Riverine Plain. This expansion has not been matched by an improved understanding of the alternate disturbance regimes that might produce better outcomes for native ecosystem conservation. Over the past 150 years, stock grazing has completely replaced fire in these grasslands. As a result, the impact of fire on native (and exotic) plant biodiversity is little understood. This study compared the current grazing regime (i.e. ‘status quo’) with burning and the removal of grazing (‘deferred’ management) across three grasslands in the Victorian Riverine Plain to determine the effects of short‐term exposure to alternate disturbances on community structure. Our results showed little change in species density, composition or abundance under the three disturbance treatments. A long exposure to stock grazing may have reduced the abundance of species likely to respond positively to burning. The cover of the biological soil crust responded positively to fire; such changes are known to significantly influence establishment and the functional composition of communities. As such, further investigation of the functional attributes of these communities may broaden our understanding of short‐term responses to alternate disturbance events. To better understand the utility of fire as a management tool, a long‐term commitment to expanding the implementation of this regime from its current extent will greatly increase the understanding of alternate disturbances in this landscape.
Progression of antiphospholipid antibody syndrome to catastrophic antiphospholipid antibody syndrome acutely with cessation of antithrombotic therapy
Authors: Katikireddi V. S. , Kandiah D. A.
Published: May 2012

Catastrophic antiphospholipid antibody syndrome (CAPS) is a serious condition that is often unrecognised with a high mortality. Cessation of anticoagulation in antiphospholipid antibody syndrome (APS) can have devastating consequences with progression to CAPS. Making a diagnosis of APS can however be challenging because of the evolving diagnostic criteria and difficulty in confirming thromboses. Management of these patients can also be complex, especially in those with coexistent thrombocytopenia. New potential treatments are emerging targeted on the immunomodulation of APS rather than just prevention of thrombosis. This article aims to highlight these diagnostic and management difficulties by reporting and discussing three cases of APS with progression to CAPS following cessation of anticoagulation, one with fatal consequences, with confirmation of CAPS on autopsy, and two with successful treatment and outcomes.
Proton pump inhibitors and diarrhoea related to Clostridium difficile infection in hospitalised patients: a case–control study
Authors: Leonard A. D. , Ho K. M. , Flexman J.
Published: May 2012

The incidence and disease severity of Clostridium difficile infection are rising. There is increasing evidence of a potential association between proton‐pump inhibitors (PPI) and C. difficile infection. We performed a case–control study to examine the relationship between PPI and polymerase chain reaction (PCR)‐proven C. difficile infection in 137 hospitalised patients in a tertiary hospital in Western Australia. Only antibiotic exposure within 3 months prior to onset of diarrhoea was associated with PCR‐proven C. difficile infection (odds ratio 5.97, 95% confidence interval 2.40–14.8, P= 0.001). A restricted analysis on those who had exposure to antibiotics within 3 months before the onset of diarrhoea did not change the negative association between PPI exposure and PCR‐proven C. difficile infection. Long‐term PPI usage and intensity of PPI exposure prior to onset of diarrhoea were not significantly associated with C. difficile infection.
Relationship between body composition, peripheral muscle strength and functional exercise capacity in patients with severe chronic obstructive pulmonary disease
Authors: Hillman C. M. , Heinecke E. L. , Hii J. W. S. , Cecins N. M. , Jenkins S. C. , Eastwood P. R.
Published: May 2012

The influence of body composition and peripheral muscle strength on 6‐minute walk distance was assessed by performing dual energy X‐ray absorptiometry scanning, spirometry and dynamometry testing in 13 men and 13 women with severe chronic obstructive pulmonary disease. Multivariate modelling showed that 76% of the variance in 6‐minute walk distance could be explained by an equation incorporating lung function, quadriceps strength and lean leg mass. These findings indicate an important role for lower limb strength measures in pulmonary rehabilitation training programmes.
Stroke management: updated recommendations for treatment along the care continuum
Authors: Wright L. , Hill K. M. , Bernhardt J. , Lindley R. , Ada L. , Bajorek B. V. , Barber P. A. , Beer C. , Golledge J. , Gustafsson L. , Hersh D. , Kenardy J. , Perry L. , Middleton S. , Brauer S. G. , Nelson M. R. ,   on behalf of the National Stroke Foundation Stroke Guidelines Expert Working Group
Published: May 2012

The Australian Clinical Guidelines for Stroke Management 2010 represents an update of the Clinical Guidelines for Stroke Rehabilitation and Recovery (2005) and the Clinical Guidelines for Acute Stroke Management (2007). For the first time, they cover the whole spectrum of stroke, from public awareness and prehospital response to stroke unit and stroke management strategies, acute treatment, secondary prevention, rehabilitation and community care. The guidelines also include recommendations on transient ischaemic attack. The most significant changes to previous guideline recommendations include the extension of the stroke thrombolysis window from 3 to 4.5 h and the change from positive to negative recommendations for the use of thigh‐length antithrombotic stockings for deep venous thrombosis prevention and the routine use of prolonged positioning for contracture management.
Medicine, art and the death of Franz Liszt
Authors: MacLaren G.
Published: May 2012

Much might be learned about the art of medicine by studying the lives of great artists. The year 2011 marked the bicentenary of the birth of Franz Liszt (1811–1886), one of the most accomplished musicians of the 19th century. Lessons relevant to contemporary medical practice can be found by examining aspects of his life and art, as well as the failure of his physicians to practise their own art during his final days.
Synaptic plasticity from amygdala to perirhinal cortex: a possible mechanism for emotional enhancement of visual recognition memory?
Authors: Perugini Alessandra , Laing Michael , Berretta Nicola , Aicardi Giorgio , Bashir Zafar I.
Published: May 2012

Emotionally salient experiences are better remembered than events that have little emotional context. Several lines of evidence indicate that the amygdala plays an important role in this emotional enhancement of memory. Visual recognition memory relies on synaptic plasticity in the perirhinal cortex, but little is known about the mechanisms involved in emotional enhancement of this form of memory. The results of the present study, performed in rat brain slices, show for the first time that the amygdala input to the perirhinal cortex undergoes synaptic plasticity. Stimulation in the amygdala resulted in long‐term potentiation (LTP) in perirhinal cortex that was dependent on β‐adrenoceptors and L‐type voltage‐dependent calcium channels (L‐VDCCs) but was NMDAR‐independent. In contrast, intracortical perirhinal stimulation resulted in LTP that was NMDAR‐dependent but β‐adrenoceptor‐ and L‐VDCC‐independent. In addition, the present results provide the first evidence that stimulation of the amygdala can reduce the threshold for LTP in the perirhinal cortex. Interestingly, this associative form of LTP requires β‐adrenoceptor activation but not NMDA or L‐VDCC activation. Knowing the mechanisms that control amygdala–perirhinal cortex interactions will allow better understanding of how emotionally charged visual events are remembered, and may help to understand how memories can consolidate and become intrusive in anxiety‐related disorders.
Marine sulfate‐reducing bacteria cause serious corrosion of iron under electroconductive biogenic mineral crust
Authors: Enning Dennis , Venzlaff Hendrik , Garrelfs Julia , Dinh Hang T. , Meyer Volker , Mayrhofer Karl , Hassel Achim W. , Stratmann Martin , Widdel Friedrich
Published: May 2012

Iron (Fe0) corrosion in anoxic environments (e.g. inside pipelines), a process entailing considerable economic costs, is largely influenced by microorganisms, in particular sulfate‐reducing bacteria (SRB). The process is characterized by formation of black crusts and metal pitting. The mechanism is usually explained by the corrosiveness of formed H2S, and scavenge of ‘cathodic’ H2 from chemical reaction of Fe0 with H2O. Here we studied peculiar marine SRB that grew lithotrophically with metallic iron as the only electron donor. They degraded up to 72% of iron coupons (10 mm × 10 mm × 1 mm) within five months, which is a technologically highly relevant corrosion rate (0.7 mm Fe0 year−1), while conventional H2‐scavenging control strains were not corrosive. The black, hard mineral crust (FeS, FeCO3, Mg/CaCO3) deposited on the corroding metal exhibited electrical conductivity (50 S m−1). This was sufficient to explain the corrosion rate by electron flow from the metal (4Fe0 → 4Fe2+ + 8e‐) through semiconductive sulfides to the crust‐colonizing cells reducing sulfate (8e‐ + SO42− + 9H+ → HS‐ + 4H2O). Hence, anaerobic microbial iron corrosion obviously bypasses H2 rather than depends on it. SRB with such corrosive potential were revealed at naturally high numbers at a coastal marine sediment site. Iron coupons buried there were corroded and covered by the characteristic mineral crust. It is speculated that anaerobic biocorrosion is due to the promiscuous use of an ecophysiologically relevant catabolic trait for uptake of external electrons from abiotic or biotic sources in sediments.
Characterization of mature testis and sperm morphology of Gymnotus carapo (Gymnotidae, Teleostei) from the southeast of Brazil
Authors: Vergílio Cristiane dos S. , Moreira Renata V. , de Carvalho Carlos E.V. , de Melo Edésio J. T.
Published: May 2012

The present study examined the testicular structure and sperm morphology of freshwater fish Gymnotus carapo. Testicular structure and sperm morphology were analyzed using light, transmission and scanning electron microscopy. Anatomically, the testes weighed 0.070 ± 0.01 g and were oval with a yellow‐white color. The G. caparo testis is organized in interstitial and tubular compartments. Spermatogenesis occurs in seminiferous tubules where the germinal epithelium is organized in spermatogenic cystis. Germ cells are seen in different stages of differentiation: type A (SPGA) and type B (SPGB) spermatogonia, primary (SPCI) and secondary (SPCII) spermatocytes, and spermatids (SPD). Differentiated spermatozoa (SZ) are seen within the cysts, characterized by a round head, a short midpiece, and a single flagellum with absence of acrosome. Spermatids were seen in the lumen of the testicular tubules together with spermatozoa, suggesting that spermatogenesis is of the semicystic type. The present study shows that G. carapo has an anastomosing tubular type of testis with an unrestricted distribution of the spermatogonia and semicystic type of spermatogenesis. Sperm structure follows the general pattern described for other teleostei species. These descriptions are important for a better understanding of reproductive biology and phylogeny, particularly of tropical fishes, for which data remain scarce in the literature.
Resolving Conflict in Problem‐Solving: Systems of Artefacts in the Development of New Routines
Authors: Cacciatori Eugenia
Published: May 2012

abstract

This paper argues that, in order to understand the development process of new routines, we have to look at the emergence of systems of artefacts rather than at individual artefacts in isolation. The paper proposes a typology of artefacts understood as material objects that are the product of human activity and analyses their interactions in the case of an integrated engineering design consultancy engaged in the effort of developing a new bidding routine. The evidence from the case study shows that agents reinforce and extend the patterns of action that individual artefacts support by bundling different types of artefacts, and that in so doing, they extend the reach and influence of the community to which they belong. This study shows that the problem‐solving and truce aspects of routines are worked out in the design of these systems of artefacts.
Microfoundations of Firm R&D Capabilities: A Study of Inventor Networks in a Merger
Authors: Paruchuri Srikanth , Eisenman Micki
Published: May 2012

abstract

Taking a cue from a recently evolving stream that calls for exploring the microfoundations of capabilities, we focus on inventor networks to examine how the activities underlying firms' R&D change in the aftermath of a merger. We view mergers as events that cause anxiety and impede inventors' abilities to process research knowledge. Employing the notion of an intra‐firm inventor collaboration network, we hypothesize that in the aftermath of a merger, the impact of knowledge that is prominent and widely available in the intra‐firm network will increase but that the impact of knowledge that, albeit richer, is less easily accessible, will decrease. Our empirical study of the merger of Bristol‐Myers and Squibb supports our hypotheses. The findings enhance our understanding not only of mergers and acquisitions, but also of the microfoundations of a firm's R&D activities.
Instructional effects of a performance support system designed to guide preservice teachers in developing technology integration strategies
Authors: Kalota Faisal , Hung Wei‐Chen
Published: May 2012

The purpose of this formative evaluation was to investigate the experiences of preservice teachers utilizing performance support system (PSS) technology to develop knowledge related to classroom technology integration. A PSS provides end users just‐in‐time support to perform various tasks. Because teachers have time constraints, a PSS can be used to support them with classroom technology integration. Both quantitative and qualitative data were used to answer the research questions. Qualitative data included focus group interviews and a perception questionnaire; these data were used to identify factors related to the participant' experiences. In addition, a pre‐ and post‐knowledge test was administered to the preservice teachers (n = 28) to study potential learning impact of a PSS for technology integration. Results showed that, although their learning improvement was not statistically significant, the participants reacted to PSS use positively, with caution. Based on the results, it is recommended that the PSS environment should be updated based on the feedback from the participants, and additional long‐term studies should be conducted to validate the current findings.

Practitioner Notes

What is known about this topic

Preservice teachers often lack technology integration skills.

Preservice teachers often do not have the necessary support that can help them develop technology integration skills.

Performance support systems (PSS) are known to provide just‐in‐time training and learning opportunities.

What this paper adds

Provides a framework for developing a PSS based on the principles of advance organizers.

Provides support to further investigate the use of PSS for preservice and in‐service teachers' professional development.

Implications for practice and/or policy

Institutions should investigate the effectiveness of using a PSS to support preservice teachers with technology integration issues.

K‐12 schools should investigate the effectiveness of using a PSS to support teachers with technology integration issues.

Designers of PSS should incorporate appropriate learning theories in the design framework of a PSS.
A group decision approach to developing concept–effect models for diagnosing student learning problems in mathematics
Authors: Hwang Gwo‐Jen , Panjaburee Patcharin , Triampo Wannapong , Shih Bo‐Ying
Published: May 2012

Diagnosing student learning barriers has been recognized as the most fundamental and important issue for improving the learning achievements of students. In the past decade, several learning diagnosis approaches have been proposed based on the concept–effect relationship (CER) model. However, past studies have shown that the effectiveness of this model heavily depends on the concept relationship knowledge provided by the domain experts (eg, experienced teachers or educators for a specified subject); ie, the performance of the developed learning diagnosis systems could be significantly affected by subjective opinions, ignorance or insufficient knowledge if those concept relationships are derived from a single domain expert. To cope with this problem, this study proposes a group decision approach for developing the CER model with the cooperation of multiple domain experts. Based on the proposed approach, a testing and diagnostic system has been implemented; moreover, an experiment has been conducted to evaluate the effectiveness of this new approach. The experimental results show that this approach is able to develop quality CER models, and hence the low‐achievement students who received the generated learning suggestions had significantly better learning achievements than those who learned with the previous approach.

Practitioner notes

What is already known about this topic

Diagnosing student learning barriers is a fundamental and important issue for improving the learning achievements of students.

Several learning diagnosis approaches have been proposed based on the concept–effect relationship (CER) model.

The effectiveness of the learning diagnosis model heavily depends on the concept relationship knowledge provided by the domain experts.

What this paper adds

A group decision approach for developing the CER model with the cooperation of multiple domain experts is proposed.

A testing and diagnostic system was implemented based on the proposed approach.

An experiment was conducted to investigating whether the students guided by the proposed approach had better learning achievements than those guided by the original CER model approach.

Implications for practice and/or policy

The experimental results show that the low‐achievement students who received the learning suggestions generated by the new approach had significantly better learning achievements than those who learned with the previous approach.

Further studies of developing more effective tools or leading in other group decision strategies to help domain experts cooperatively determine the prerequisite relationships are needed.
Games for engaged learning of middle school children with special learning needs
Authors: Ke Fengfeng , Abras Tatiana
Published: May 2012

In this paper, we describe an in situ study that examined the diverse design features and effects of three pre‐algebra games for middle school children who have either challenges with learning or different language backgrounds. Data were collected through in‐field observation, artifact analysis, school performance report and knowledge test during 15 one‐hour gaming sessions over a period of 3 weeks. A list of key design features related to creating engagement and learning for students with special learning needs emerged from the data. The findings and discussions will inform educational designers and practitioners on successful educational game design and implementation for learners with diverse characteristics and needs.

Practitioner notes

What is already known about this topic

Computer games can act as rich primers for engaged learning of academic content.

What this paper adds

The potential for computer games to promote engaged learning for school children with learning difficulty or different language/cultural backgrounds.

The common and unique game design features that promote engaged learning for school children with special learning needs.

Game‐based learner support for school children with special learning needs.

Implications for practice and/or policy

Educational game designers should make purposeful design efforts (eg, a simple fantasy, open‐ended game challenges and scaffolding with visual cue/feedback) to create learner‐adaptive engagement.

Content processing should be a core and active part of the game‐play to promote game‐based learning.

Adaptive and nonintrusive support should be provided to student players to reinforce game‐based learning.
Multicut‐High Dimensional Model Representation for Structural Reliability Bounds Estimation Under Mixed Uncertainties
Authors: Balu A. S. , Rao B. N.
Published: May 2012

Abstract:  In reliability analysis of structural systems involving both aleatory and epistemic uncertainties, in conjunction with multiple design points, every configuration of the interval variables is to be explored to determine the bounds on reliability. To reduce the computational cost involved, this article presents a novel uncertain analysis method for estimating the bounds on reliability of structural systems involving multiple design points in the presence of mixed uncertain (both random and fuzzy) variables. The proposed method involves Multicut‐High Dimensional Model Representation (MHDMR) technique for the limit state/performance function approximation, the transformation technique to obtain the contribution of the fuzzy variables to the convolution integral and fast Fourier transform for solving the convolution integral. The limit state function approximation is obtained by linear and quadratic approximations of the first‐order HDMR component functions at the most probable point. In the proposed method, efforts are required in evaluating conditional responses at a selected input determined by the sample points, as compared to full‐scale simulation methods. Therefore, the proposed technique estimates the failure probability accurately with significantly less computational effort compared to the direct Monte Carlo simulation. The methodology developed is applicable for structural reliability estimation involving any number of fuzzy variables and random variables with any kind of distribution. The accuracy and efficiency of the proposed method is demonstrated through four examples involving explicit/implicit performance functions.
In Pursuit of Quality. The Institutional Change of Wine Production Market in Piedmont
Authors: Barbera Filippo , Audifredi Stefano
Published: May 2012

This article analyses the consequences of the ‘methanol wine scandal’ on the wine production market of Piedmont. Contrary to what is usually claimed, these consequences where not the direct result of the scandal, but emerged only when a change in the institutional configuration of the market came about. The article illustrates how the institutional change following the scandal triggered the quality turn of the wine production market in Piedmont. The key processes at the root of this change are depicted in terms of quality conventions as coordination mechanisms embedded in the institutional context. The first part of the article outlines the conceptual coordinates concerning the ‘social construction’ of quality. Afterwards both the general and regional trends toward the quality production in the national and local wine sector are summarised. Then ‘the methanol wine scandal’ and its institutional consequences are illustrated. Finally, to appreciate the current organization of the local production market and of the quality conventions among wine producers, findings from interviews with local entrepreneurs are reported.
RECONCILING RELIGIOUS TRADITION AND MODERN SCIENCE
Authors: Brooke John Hedley
Published: May 2012

Abstract The primary purpose of this essay is to review Nidhal Guessoum's Islam's Quantum Question from a perspective outside Muslim tradition. Having outlined the main contours and contentions of the book, general issues are raised concerning the reconciliation of religious belief with the sciences. Comparisons are drawn between the resources available to Christian and Muslim cultures for achieving reconciliation, with particular reference to scriptural exegesis and natural theology. Speculative questions are then raised concerning possible differences between the Christian and Islamic experience and whether these may shed any light on the facilitation in Europe of an enduring scientific movement.
PRACTICE AND THE AGENDA OF “ISLAM AND SCIENCE”
Authors: Bagir Zainal Abidin
Published: May 2012

Abstract When speaking about Islam and contemporary issues in science, Guessoum's Islam's Quantum Question shares many characterizations with Barbourian science and religion discourse. The focus is on theological responses to particular scientific theories. In this article I suggest an expansion of the discourse by looking at how science meets religion (as well as other local system of knowledge) in practice, in particular events such as natural disaster, when they are called upon as sources of meaning making. The encounter takes place not only at the cognitive level, but may take the form of competition, collaboration, or negotiation over the authority to provide explanation. In practice the authority is supported not only by objective knowledge but involves many other factors, including politics. Thus, part of my proposal for expansion suggests the broadening of how we understand science and religion to include how assertions of authority are made in practice.
THE MEDIATIZED CO‐MEDIATIZER: ANTHROPOLOGY IN NIKLAS LUHMANN'S WORLD
Authors: Moon Young Bin
Published: May 2012

AbstractThis essay explores what it means to be human in an age of infomedia. Appropriating Niklas Luhmann's systems theory/media theory in dialogue with other resources, I propose a post‐Luhmannian paradigm of (1) extended media/meaning that conceives the world as world multimedia systems processing variegated meanings, and (2) an embodied, contextualized soft posthumanist anthropology that conceives the human as emergent collective phenomena of distinct meaning making by body‐mind‐society‐technology media couplings. I argue: (1)Homo sapiensisHomo medialisdistinct with mediatic communication that emerged to cope with contingencies. (2) Evolution is the mediatization/codification of the world that culminated with the outcome ofHomo medialisuniquely equipped to process transcendent meanings and to mediatize the world via diverse media—Mediatized Co‐Mediatizer or Codified Co‐Codifier. (3) This anthropic universe is possibly the most “meaningful” (full of meaning possibilities) of all possible worlds. (4) Social fragmentation could be an optimization; science‐and‐religion is an infomedium optimizing religion's manifest and science’ latent observation of divine manifestations.
THE MYSTERIES OF OUR EXISTENCE: ESTRANGEMENT AND THEATRICALITY
Authors: CARNES NATALIE
Published: May 2012

“Theater” has become a fashionable metaphor that theologians and ethicists deploy to correct what they see as a Gnostic or antinomian impulse to prioritize “inner state” over “outer action.” But their turn to theater as an easy way to valorize “outer action” conflates person and role, generating a confused anthropology that 1) obscures what theater could make obvious about occupational roles; 2) misses the distinctively non‐theatrical character of performing Christ and church; and 3) renders actions more easily legible than they in fact are. These losses are traced in the work of several theater theologians, and their resultant distortions in self, power, and freedom are elaborated with the help of Stephen Mulhall's critique of Alasdair MacIntyre and Charles Taylor. Gregory of Nyssa's use of theater, by contrast, avoids such distortions by invoking theater together with the “mysteries of our existence”—death and creatio ex nihilo. Theater, for Gregory, becomes a way to describe the estrangement Christians must live into in a world beholden to wealth and power. The anthropology embedded in his metaphor of theater elaborates how Christians might approach their occupational roles, the world, and skepticism.