bluuebunny/crossref_metadata_2025 huggingface dataset:
Responses of microbial phototrophs to late‐Holocene environmental forcing of lakes in south‐west Greenland
Authors: REUSS NINA S. , ANDERSON N. JOHN , FRITZ SHERILYN C. , SIMPSON GAVIN L.
Published: December 2012

1. The biological structure of arctic lakes is changing rapidly, apparently in response to global change processes such as increasing air temperatures, although altered nutrient stoichiometry may also be an important driver. Equally important, however, are local factors (e.g. landscape setting, hydrological linkages and trophic interactions) that may mediate responses of individual lakes at the regional scale. Despite general acknowledgement of the importance of local factors, there has been little focus on among‐lake variability in the response to environmental change.

2. Sedimentary pigments, organic carbon and nitrogen, and biogenic silica (BSi) in 210Pb and 14C‐dated sediment cores from three contrasting lakes in the Kangerlussuaq area (c. 67°N, 51°W) of south‐west Greenland were used to reconstruct algal and phototrophic bacterial ecological change during the late‐Holocene. Water chemistry for the individual lakes varies in terms of conductivity (range: 30–3000 μS cm−1) and stratification regimes (cold monomictic, dimictic and meromictic), linked with their position along the regional climate gradient from the coast and to the present ice sheet margin.

3. Despite essentially similar regional climate forcing over the last c. 1000 years, marked differences among lake types were observed in the phototrophic communities and their temporal variability. Considerable short‐term variability occurred in an oligosaline, meromictic lake (SS1371), dominated by purple sulphur bacterial pigments, most likely due to a tight coupling between the position of the chemocline and the phototrophic community. Communities in a lake (SS86) located on a nunatak, just beyond the edge of the present ice sheet shifted in a nonlinear pattern, approximately 1000 cal. years BP, possibly due to lake‐level lowering and loss of outflow during the Medieval Climate Anomaly. This regime shift was marked by a substantial expansion of green sulphur bacteria.

4. A dilute, freshwater coastal lake (SS49) dominated by benthic algae was relatively stable until ca. 1900 AD when rates of community change began to increase. These changes in benthic algal pigments are correlated with substantial declines (1.3–0.44‰) in δ15N that are indicative of increased deposition of atmospheric inputs of industrially derived NOx into the atmosphere.

5. Climate control on lake ecosystem functioning has been assumed to be particularly important in the Arctic. This study, however, illustrates a complex spatial response to climate forcing at the regional scale and emphasises differences in the relative importance of changes in the mass (m, both precipitation and nutrients) and energy flux (E) to lakes for the phototrophic community structure of low‐arctic Greenland lakes.
Climate‐induced changes in the distribution of freshwater fish: observed and predicted trends
Authors: COMTE LISE , BUISSON LAËTITIA , DAUFRESNE MARTIN , GRENOUILLET GAËL
Published: December 2012

1. Climate change could be one of the main threats faced by aquatic ecosystems and freshwater biodiversity. Improved understanding, monitoring and forecasting of its effects are thus crucial for researchers, policy makers and biodiversity managers.

2. Here, we provide a review and some meta‐analyses of the literature reporting both observed and predicted climate‐induced effects on the distribution of freshwater fish. After reviewing three decades of research, we summarise how methods in assessing the effects of climate change have evolved, and whether current knowledge is geographically or taxonomically biased. We conducted multispecies qualitative and quantitative analyses to find out whether the observed responses of freshwater fish to recent changes in climate are consistent with those predicted under future climate scenarios.

3. We highlight the fact that, in recent years, freshwater fish distributions have already been affected by contemporary climate change in ways consistent with anticipated responses under future climate change scenarios: the range of most cold‐water species could be reduced or shift to higher altitude or latitude, whereas that of cool‐ and warm‐water species could expand or contract.

4. Most evidence about the effects of climate change is underpinned by the large number of studies devoted to cold‐water fish species (mainly salmonids). Our knowledge is still incomplete, however, particularly due to taxonomic and geographic biases.

5. Observed and expected responses are well correlated among families, suggesting that model predictions are supported by empirical evidence. The observed effects are of greater magnitude and show higher variability than the predicted effects, however, indicating that other drivers of changes may be interacting with climate and seriously affecting freshwater fish.

6. Finally, we suggest avenues of research required to address current gaps in what we know about the climate‐induced effects on freshwater fish distribution, including (i) the need for more long‐term data analyses, (ii) the assessment of climate‐induced effects at higher levels of organisation (e.g. assemblages), (iii) methodological improvements (e.g. accounting for uncertainty among projections and species’ dispersal abilities, combining both distributional and empirical approaches and including multiple non‐climatic stressors) and (iv) systematic confrontation of observed versus predicted effects across multi‐species assemblages and at several levels of biological organisation (i.e. populations and assemblages).
Winter climate change and coastal wetland foundation species: salt marshes vs. mangrove forests in the southeastern United States
Authors: Osland Michael J. , Enwright Nicholas , Day Richard H. , Doyle Thomas W.
Published: December 2012

We live in an era of unprecedented ecological change in which ecologists and natural resource managers are increasingly challenged to anticipate and prepare for the ecological effects of future global change. In this study, we investigated the potential effect of winter climate change upon salt marsh and mangrove forest foundation species in the southeastern United States. Our research addresses the following three questions: (1) What is the relationship between winter climate and the presence and abundance of mangrove forests relative to salt marshes; (2) How vulnerable are salt marshes to winter climate change‐induced mangrove forest range expansion; and (3) What is the potential future distribution and relative abundance of mangrove forests under alternative winter climate change scenarios? We developed simple winter climate‐based models to predict mangrove forest distribution and relative abundance using observed winter temperature data (1970–2000) and mangrove forest and salt marsh habitat data. Our results identify winter climate thresholds for salt marsh–mangrove forest interactions and highlight coastal areas in the southeastern United States (e.g., Texas, Louisiana, and parts of Florida) where relatively small changes in the intensity and frequency of extreme winter events could cause relatively dramatic landscape‐scale ecosystem structural and functional change in the form of poleward mangrove forest migration and salt marsh displacement. The ecological implications of these marsh‐to‐mangrove forest conversions are poorly understood, but would likely include changes for associated fish and wildlife populations and for the supply of some ecosystem goods and services.
Gap filling strategies and error in estimating annual soil respiration
Authors: Gomez‐Casanovas Nuria , Anderson‐Teixeira Kristina , Zeri Marcelo , Bernacchi Carl J. , DeLucia Evan H.
Published: December 2012

Soil respiration (Rsoil) is one of the largest CO2 fluxes in the global carbon (C) cycle. Estimation of annual Rsoil requires extrapolation of survey measurements or gap filling of automated records to produce a complete time series. Although many gap filling methodologies have been employed, there is no standardized procedure for producing defensible estimates of annual Rsoil. Here, we test the reliability of nine different gap filling techniques by inserting artificial gaps into 20 automated Rsoil records and comparing gap filling Rsoil estimates of each technique to measured values. We show that although the most commonly used techniques do not, on average, produce large systematic biases, gap filling accuracy may be significantly improved through application of the most reliable methods. All methods performed best at lower gap fractions and had relatively high, systematic errors for simulated survey measurements. Overall, the most accurate technique estimated Rsoil based on the soil temperature dependence of Rsoil by assuming constant temperature sensitivity and linearly interpolating reference respiration (Rsoil at 10 °C) across gaps. The linear interpolation method was the second best‐performing method. In contrast, estimating Rsoil based on a single annual Rsoil – Tsoil relationship, which is currently the most commonly used technique, was among the most poorly‐performing methods. Thus, our analysis demonstrates that gap filling accuracy may be improved substantially without sacrificing computational simplicity. Improved and standardized techniques for estimation of annual Rsoil will be valuable for understanding the role of Rsoil in the global C cycle.
Local temperatures inferred from plant communities suggest strong spatial buffering of climate warming across Northern Europe
Authors: Lenoir Jonathan , Graae Bente Jessen , Aarrestad Per Arild , Alsos Inger Greve , Armbruster W. Scott , Austrheim Gunnar , Bergendorff Claes , Birks H. John B. , Bråthen Kari Anne , Brunet Jörg , Bruun Hans Henrik , Dahlberg Carl Johan , Decocq Guillaume , Diekmann Martin , Dynesius Mats , Ejrnæs Rasmus , Grytnes John‐Arvid , Hylander Kristoffer , Klanderud Kari , Luoto Miska , Milbau Ann , Moora Mari , Nygaard Bettina , Odland Arvid , Ravolainen Virve Tuulia , Reinhardt Stefanie , Sandvik Sylvi Marlen , Schei Fride Høistad , Speed James David Mervyn , Tveraabak Liv Unn , Vandvik Vigdis , Velle Liv Guri , Virtanen Risto , Zobel Martin , Svenning Jens‐Christian
Published: December 2012

Recent studies from mountainous areas of small spatial extent (<2500 km2) suggest that fine‐grained thermal variability over tens or hundreds of metres exceeds much of the climate warming expected for the coming decades. Such variability in temperature provides buffering to mitigate climate‐change impacts. Is this local spatial buffering restricted to topographically complex terrains? To answer this, we here study fine‐grained thermal variability across a 2500‐km wide latitudinal gradient in Northern Europe encompassing a large array of topographic complexities. We first combined plant community data, Ellenberg temperature indicator values, locally measured temperatures (LmT) and globally interpolated temperatures (GiT) in a modelling framework to infer biologically relevant temperature conditions from plant assemblages within <1000‐m2 units (community‐inferred temperatures: CiT). We then assessed: (1) CiT range (thermal variability) within 1‐km2 units; (2) the relationship between CiT range and topographically and geographically derived predictors at 1‐km resolution; and (3) whether spatial turnover in CiT is greater than spatial turnover in GiT within 100‐km2 units. Ellenberg temperature indicator values in combination with plant assemblages explained 46–72% of variation in LmT and 92–96% of variation in GiT during the growing season (June, July, August). Growing‐season CiT range within 1‐km2 units peaked at 60–65°N and increased with terrain roughness, averaging 1.97 °C (SD = 0.84 °C) and 2.68 °C (SD = 1.26 °C) within the flattest and roughest units respectively. Complex interactions between topography‐related variables and latitude explained 35% of variation in growing‐season CiT range when accounting for sampling effort and residual spatial autocorrelation. Spatial turnover in growing‐season CiT within 100‐km2 units was, on average, 1.8 times greater (0.32 °C km−1) than spatial turnover in growing‐season GiT (0.18 °C km−1). We conclude that thermal variability within 1‐km2 units strongly increases local spatial buffering of future climate warming across Northern Europe, even in the flattest terrains.
Miscanthus × giganteus and Arundo donax shoot and rhizome tolerance of extreme moisture stress
Authors: Mann J. Jeremiah , Barney Jacob N. , Kyser Guy B. , Di Tomaso Joseph M.
Published: December 2012

Crops grown for bioenergy production are a mandated component of the United States energy portfolio. Giant miscanthus (Miscanthus × giganteus) is a leading bioenergy crop similar in habit to the invasive plant giant reed (Arundo donax). To characterize the environmental tolerance of giant miscanthus, we compared the soil moisture stress tolerance of giant miscanthus and giant reed under glasshouse conditions. We subjected both species to soil moisture conditions of severe drought (−4.2 MPa), mild drought (−0.5 MPa), field‐capacity (control), and flooded soils. These conditions were applied to two cohorts: one in which soil moisture conditions were imposed on newly planted rhizome fragments, and one in which conditions were imposed on established plants after 8 weeks of growth in field‐capacity soil. After 16 weeks, we harvested all plants, measured above‐ and belowground biomass, and evaluated the reproductive viability of rhizome fragments. The total biomass of each species under flooded conditions was not different from the field‐capacity control groups regardless of cohort. However, drought did affect the two cohorts differently. In the cohort treated after 8 weeks of growth, mild and severe drought conditions resulted in 56% and 66% reductions in biomass, averaged over both species, compared with the controls. In the cohort treated for the entire 16 weeks, mild and severe drought conditions resulted in 92% and 94% reductions in biomass. Rhizome fragments from both species and both cohorts showed 100% viability following flooded and control treatments; drought treatments reduced rhizome viability in both species, with a greater impact on giant miscanthus. Although giant miscanthus does not appear to have the potential to escape and establish in relatively dry upland ecosystems, it does show tolerance to flooded conditions similar to giant reed.
Controlled Dismantlement of the Eurozone: A Strategy to Save the European Union and the Single European Market
Authors: Kawalec Stefan , Pytlarczyk Ernest
Published: December 2012

The problems with a single currency in Europe are neither temporary nor curable. Any persistent defence of the euro will result in a long-lasting recession and high unemployment in countries using fiscal austerity to pursue ‘internal devaluation’. It may lead to a revival of populist and nationalist movements, political collapse and disorderly eurozone break-up. This article argues for a controlled segmentation of the eurozone via the exit of the most competitive countries and an agreement on a new European currency coordination system.
Antimicrobial activity and surface properties of an acrylic resin containing a biocide polymer
Authors: Compagnoni Marco A. , Pero Ana C. , Ramos Stella M. M. , Marra Juliê , Paleari André G. , Rodriguez Larissa S.
Published: December 2012

Objective

To evaluate the antimicrobial activity and surface properties of an acrylic resin containing the biocide polymer poly (2‐tert‐butylaminoethyl) methacrylate (PTBAEMA).

Background

Several approaches have been proposed to prevent oral infections, including the incorporation of antimicrobial agents to acrylic resins.

Materials and methods

Specimens of an acrylic resin (Lucitone 550) were divided into two groups: 0% (control) and 10% PTBAEMA. Antimicrobial activity was assessed by adherence assay of one of the microorganisms, Staphylococcus aureus, Streptococcus mutans and Candida albicans. Surface topography was characterised by atomic force microscopy and wettability properties determined by contact angle measurements.

Results

Data of viable cells (log (CFU + 1)/ml) for S. aureus (control: 7.9 ± 0.8; 10%: 3.8 ± 3.3) and S. mutans (control: 7.5 ± 0.7; 10%: 5.1 ± 2.7) showed a significant decrease with 10% of PTBAEMA (Mann–Whitney, p < 0.05). For C. albicans (control: 6.6 ± 0.2; 10%: 6.6 ± 0.4), there was no significant difference between control and 10% of PTBAEMA (Kruskal–Wallis, p > 0.05). Incorporating 10% PTBAEMA increased surface roughness and decreased contact angles.

Conclusion

Incorporating 10% PTBAEMA into acrylic resins increases wettability and roughness of acrylic resin surface; and decreases the adhesion of S. mutans and S. aureus on acrylic surface, but did not exhibit antimicrobial effect against C. albicans.
Weakening processes in thrust faults: insights from the Monte Perdido thrust fault (southern Pyrenees, Spain)
Authors: Lacroix B. , Leclère H. , Buatier M. , Fabbri O.
Published: December 2012

The Monte Perdido thrust fault (southern Pyrenees) consists of a 6‐m‐thick interval of intensely deformed clay‐bearing rocks. The fault zone is affected by a pervasive pressure solution seam and numerous shear surfaces. Calcite extensional‐shear veins are present along the shear surfaces. The angular relationships between the two structures indicate that shear surfaces developed at a high angle (70°) to the local principal maximum stress axis σ1. Two main stages of deformation are present. The first stage corresponds to the development of calcite shear veins by a combination of shear surface reactivation and extensional mode I rupture. The second stage of deformation corresponds to chlorite precipitation along the previously reactivated shear surfaces. The pore fluid factor λ computed for the two deformation episodes indicates high fluid pressures during the Monte Perdido thrust activity. During the first stage of deformation, the reactivation of the shear surface was facilitated by a suprahydrostatic fluid pressure with a pore fluid factor λ equal to 0.89. For the second stage, the fluid pressure remained still high (with a λ value ranging between 0.77 and 0.84) even with the presence of weak chlorite along the shear surfaces. Furthermore, evidence of hydrostatic fluid pressure during calcite cement precipitation supports that incremental shear surface reactivations are correlated with cyclic fluid pressure fluctuations consistent with a fault‐valve model.
High frequency of calcification in basal ganglia on brain computed tomography images in Japanese older adults
Authors: Yamada Megumi , Asano Takahiko , Okamoto Kouichirou , Hayashi Yuichi , Kanematsu Masayuki , Hoshi Hiroaki , Akaiwa Yasuhisa , Shimohata Takayoshi , Nishizawa Masatoyo , Inuzuka Takashi , Hozumi Isao
Published: December 2012

Aim

To investigate the frequency of calcification in the basal ganglia and the dentate nuclei in the cerebellum, and compare the difference in age and area, we examined the brain computed tomography (CT) images of all patients in two representative university hospitals in Japan.

Methods

We examined the brain CT images of 2526 patients in Gifu University Hospital (UH) and 2573 patients in Niigata UH. These patients were examined in these hospitals from October 2009 to September 2010.

Results

Punctate calcification of the basal ganglia was observed in 435 of 2526 patients (17.2%) in Gifu UH and 530 of 2573 patients (20.6%) in Niigata UH. The frequency of calcification increased with age. Patchy calcification of the basal ganglia was observed in 32 (1.3%) and 50 patients (1.9%) in Gifu UH and Niigata UH, respectively. Among patients aged over 65 years, 24 (2.1%) and 34 (3.1%) patients showed patchy calcification in Gifu UH and Niigata UH, respectively. Calcification of the cerebellar dentate nuclei was detected in just seven and four patients in Gifu UH and Niigata UH, respectively.

Conclusion

Compared with previous reports, the frequency of calcification of the basal ganglia in this study markedly increased. This might be because of the increased number of older adults and the increased sensitivity of CT. Geriatr Gerontol Int 2013; 13: 706–710.
Evaluation of chewing ability and its relationship with activities of daily living, depression, cognitive status and food intake in the community‐dwelling elderly
Authors: Kimura Yumi , Ogawa Hiroshi , Yoshihara Akihiro , Yamaga Takayuki , Takiguchi Tomoya , Wada Taizo , Sakamoto Ryota , Ishimoto Yasuko , Fukutomi Eriko , Chen Wenling , Fujisawa Michiko , Okumiya Kiyohito , Otsuka Kuniaki , Miyazaki Hideo , Matsubayashi Kozo
Published: December 2012

Aim

The aim of this study was to assess chewing ability using color‐changeable chewing gum and to show the association between chewing ability and geriatric functions, as well as dietary status in the community‐dwelling elderly.

Methods

The study population consisted of 269 community‐dwelling elderly aged ≥75 living in Tosa, Japan. Assessment of chewing ability was carried out by a dentist using color‐changeable chewing gum. Activities of daily living (ADL), depression and subjective quality of life (QOL) were assessed by questionnaire. Cognitive status was assessed by; Mini‐Mental State Examination (MMSE), Hasegawa Dementia Scale‐Revised (HDS‐R) and Frontal Assessment Battery (FAB) during the check‐up. Food diversity was assessed using the 11‐item Food Diversity Score Kyoto (FDSK‐11).

Results

Number of teeth was significantly related to chewing ability (P < 0.001). The participants with low chewing ability had significantly lower ADL scores in the items of self‐maintenance (P = 0.029) and intellectual activity (P = 0.021). There was a significant association between low chewing ability and depression (P < 0.001). Lower cognitive functions were significantly related to low chewing ability; MMSE (P = 0.022), HDSR (P = 0.017) and FAB (P = 0.002). The participants with low chewing ability had lower food variety (P < 0.001), and less frequent intake of beans, vegetables, seaweed and nuts, than the participants with high chewing ability.

Conclusion

Low chewing ability evaluated by color‐changeable gum was associated with lower ADL, lower cognitive functioning, depression and food insufficiency in the community‐dwelling elderly. More attention should be paid to assessing chewing ability of elderly persons in community settings. Geriatr Gerontol Int 2013; 13: 718–725.
Preoperative prediction of macrophage infiltration by 3‐D tomographic ultrasound in endoarterectomized carotid plaques in elderly patients
Authors: Koyama Shun‐ichi , Hashimoto Takao , Umahara Takahiko , Akai Tomotaka , Watanabe Daisuke , Akimoto Jiro , Nagao Toshitaka , Uchihara Toshiki , Haraoka Jo , Iwamoto Toshihiko
Published: December 2012

Aim

Assessment of plaque characteristics is important for the optimal treatment of carotid stenosis, particularly in elderly patients. Macrophage infiltration is reported to be involved in carotid plaque instability. However, immunohistochemical assessment of the detailed localization of macrophage infiltration in carotid plaques remains limited. We attempted to elucidate this using 3‐D ultrasonography (3D‐US). We compared findings of the detailed localization of macrophage infiltration with findings from the newly developed tomographic ultrasound imaging (TUI).

Methods

We obtained specimens of carotid arteries from 18 patients undergoing carotid endarterectomy (CEA), and investigated the localization of macrophages and vascular smooth muscle cells. Their localization obtained from 11 patients was compared with their preoperative TUI findings.

Results

We classified the localization of macrophage infiltration into four types: (i) focal infiltration in the thick fibrous cap (12 cases); (ii) subendothelial zonal infiltration (2 cases); (iii) peripheral infiltration around the lipid core (8 cases); and (iv) local infiltration near the shoulder of the fibrous cap (2 cases). Among them, preoperative TUI was available in 11 CEA cases for histological comparison. We identified two sites of focal macrophage infiltration that corresponded to local echogenic lesions without an acoustic shadow on TUI. The proliferation of smooth muscle cells failed to show an apparent echogenicity.

Conclusions

TUI could not only evaluate the morphological features, but also showed the two types of focal macrophage infiltration relevant to plaque instability as an echogenic focus. TUI carried out by 3D‐US is an easily applicable and non‐invasive method that is considered useful for evaluating carotid plaques in elderly patients. Geriatr Gerontol Int 2013; 13: 834–841.
Higher Glutamate to Glutamine Ratios in Occipital Regions in Women With Migraine During the Interictal State
Authors: González de la Aleja Jesús , Ramos Ana , Mato‐Abad Virginia , Martínez‐Salio Antonio , Hernández‐Tamames Juan A. , Molina José Antonio , Hernández‐Gallego Jesús , Álvarez‐Linera Juan
Published: December 2012

Background

Glutamate (Glu) and glutamine (Gln) are strongly compartmentalized (in neurons for Glu and in astrocytes for Gln). The visual cortex is the brain region with a higher neuron/astrocyte ratio (the highest neuronal density and the relatively lowest density of astrocytes). Elevations in extracellular Glu or potassium above certain thresholds are likely candidates to be the final common steps in the multiple distinct processes that can lead to cortical spreading depression. Astrocytes play a key role in this phenomenon, by acting as a sink for extracellular Glu and potassium, as well as generally acting as a buffer for the ionic and neurochemical changes that initiate and propagate cortical spreading depression.

Objective

The purpose of this study was to quantify Glu and Gln to generate Glu/Gln ratios in women with migraine during the interictal state compared with healthy control women.

Methods

Twenty‐seven patients with migraine (8 with aura and 19 without aura) and 19 matched healthy controls were included in the study. We performed proton magnetic resonance spectroscopy in the anterior paracingulate cortex and occipital cortex (OC). Spectral analysis was performed by LCModel, allowing a separation of Glu and Gln using a 3T machine.

Results

The main result was a significantly higher Glu/Gln ratio in the OC of migraine patients compared with healthy control subjects (4.87 for migraineurs [standard deviation (SD) = 2.74] and 3.42 for controls [SD = 1.52], P = .042). We also observed higher Glu levels (6.98 for migraineurs [SD = 0.85] and 6.22 for controls [SD = 0.97], P = .007) and Glu/creatine + phosphocreatine ratio (1.18 for migraineurs [SD = 0.18] and 1.00 for controls [SD = 0.16], P = .001) in anterior paracingulate cortex in migraine patients but saw no differences in Glu/Gln ratio (2.79 for migraineurs [SD = 1.11] and 2.63 for controls [SD = 1.61], P = .68).

Conclusion

These findings are consistent with glutamatergic differences in migraine patients during the interictal period compared with healthy controls. We hypothesize that an increased Glu/Gln ratio could arise from neuronal–glial coupling of glutamatergic metabolism differences or an increased neuron/astrocyte ratio in the OC.
Serum oxidative–anti‐oxidative stress balance is dysregulated in patients with hepatitis C virus‐related hepatocellular carcinoma
Authors: Nishimura Mamoru , Takaki Akinobu , Tamaki Naofumi , Maruyama Takayuki , Onishi Hideki , Kobayashi Sayo , Nouso Kazuhiro , Yasunaka Tetsuya , Koike Kazuko , Hagihara Hiroaki , Kuwaki Kenji , Nakamura Shinichiro , Ikeda Fusao , Iwasaki Yoshiaki , Tomofuji Takaaki , Morita Manabu , Yamamoto Kazuhide
Published: December 2012

Aim

Oxidative stress is associated with progression of chronic liver disease (CLD). This association is best established in chronic hepatitis C. However, the anti‐oxidative state is not well characterized. The objective of the present study was to investigate the balance of oxidative and anti‐oxidative stress in CLD patients.

Methods

We recruited a study population of 208 patients, including healthy volunteers (HV; n = 15), patients with hepatitis B virus (HBV)‐related CLD without or with hepatocellular carcinoma (HBV‐non‐HCC, n = 25, and HBV‐HCC, n = 50, respectively), and patients with hepatitis C virus (HCV)‐related CLD without or with HCC (HCV‐non‐HCC, n = 49, and HCV‐HCC, n = 69, respectively). Serum levels of reactive oxygen metabolites (ROM) and anti‐oxidative markers (OXY‐adsorbent test; OXY) were determined, and the balance of these values was used as the oxidative index. Correlations among ROM, OXY, oxidative index and clinical characteristics were investigated.

Results

Patients with CLD exhibited elevated ROM and oxidative index compared to HV. Among patients with CLD, HCV positive status correlated with increased ROM. In CLD, HCV‐HCC patients exhibited the highest ROM levels. Among HCV‐related CLD patients, lower OXY correlated with HCC positive status, but was recovered by eradication of HCC. In HCV‐HCC, lower OXY correlated with high PT‐INR.

Conclusion

HCV positive CLD patients displayed higher oxidative stress and HCV‐HCC patients displayed lower anti‐oxidative state. Anti‐oxidative state depression was associated with liver reservoir‐related data in HCV‐HCC and could be reversed with HCC eradication.
Towards antibacterial endodontic sealers using quaternary ammonium nanoparticles
Authors: Kesler Shvero D. , Abramovitz I. , Zaltsman N. , Perez Davidi M. , Weiss E. I. , Beyth N.
Published: December 2012

Aim

To change and characterize the antibacterial properties of endodontic sealers by incorporating low concentrations of insoluble antibacterial nanoparticles (IABN).

Methodology

The antibacterial effect againstEnterococcus faecaliswas evaluated by (i) agar diffusion test (ADT), (ii) direct contact test (DCT) and (iii) scanning electron microscopy (SEM).IABNwere incorporated intoAHPlus (Dentsply, DeTrey Konstanz, Germany) and GuttaFlow (Coltène Whaledent, Langenau, Germany) at concentrations of 0.5%, 1% or 2% weight/weight. Bacterial growth rates were analysed usingANOVAfollowed by Tukey's test.

Results

The antibacterial tests demonstrated total bacterial growth inhibition usingAHPlus samples incorporating 2% weight/weightIABNafter 4 weeks (P < 0.005).DCTshowed total growth inhibition of up to 6 logs in viable count inAHPlus samples incorporatingIABNand up to 4 log in count in GuttaFlow incorporatingIABN(P < 0.005). Significant differences were found between the unmodified sealers and the experimental groups. No antibacterial effect was observed in theADT, indicatingIABNwere not diffusing into the agar. Furthermore,SEMindicated bacterial cell wall damage and lysis.

Conclusions

AHPlus and GuttaFlow incorporating low concentrations ofIABNexhibited significant and stable antimicrobial properties.
16th IHIW: Anti‐HLA alloantibodies of the of IgA isotype in re‐transplant candidates
Authors: Arnold M.‐L. , Heinemann F. M. , Horn P. , Ziemann M. , Lachmann N. , Mühlbacher A. , Dick A. , Ender A. , Thammanichanond D. , Fischer G. F. , Schaub S. , Hallensleben M. , Mytilineos J. , Hitzler W. E. , Seidl C. , Doxiadis I. I. N. , Spriewald B. M.
Published: December 2012

In this multicentre study, sera from 803 retransplant candidates, including 775 kidney transplant recipients, were analysed with regard to the presence and specificity of anti‐HLA alloantibodies of the IgA isotype using a modified microsphere‐based platform. Of the kidney recipients, nearly one‐third (n = 237, 31%) had IgA alloantibodies. Mostly, these antibodies were found in sera that also harboured IgG alloantibodies that could be found in a total of 572 (74%) of patients. Interestingly, IgA anti‐HLA antibodies were preferentially targeting HLA class I antigens in contrast to those of the IgG isotype, which targeted mostly both HLA class I and II antigens. Donor specificity of the IgA alloantibodies could be established for over half of the 237 patients with IgA alloantibodies (n = 124, 52%). A further 58 patients had specificities against HLA‐C or HLA‐DP, for which no information regarding donor typing was available. In summary, these data showed in a large cohort of retransplant candidates that IgA alloantibodies occur in about one‐third of patients, about half of these antibodies being donor specific.
16th IHIW: Analysis of HLA Population Data, with updated results for 1996 to 2012 workshop data (AHPD project report)
Authors: Riccio M. E. , Buhler S. , Nunes J. M. , Vangenot C. , Cuénod M. , Currat M. , Di D. , Andreani M. , Boldyreva M. , Chambers G. , Chernova M. , Chiaroni J. , Darke C. , Di Cristofaro J. , Dubois V. , Dunn P. , Edinur H. A. , Elamin N. , Eliaou J.‐F. , Grubic Z. , Jaatinen T. , Kanga U. , Kervaire B. , Kolesar L. , Kunachiwa W. , Lokki M. L. , Mehra N. , Nicoloso G. , Paakkanen R. , Voniatis D. Papaioannou , Papasteriades C. , Poli F. , Richard L. , Romón Alonso I. , Slavčev A. , Sulcebe G. , Suslova T. , Testi M. , Tiercy J.‐M. , Varnavidou A. , Vidan‐Jeras B. , Wennerström A. , Sanchez‐Mazas A.
Published: December 2012

We present here the results of the Analysis of HLA Population Data (AHPD) project of the 16th International HLA and Immunogenetics Workshop (16IHIW) held in Liverpool in May–June 2012. Thanks to the collaboration of 25 laboratories from 18 different countries, HLA genotypic data for 59 new population samples (either well‐defined populations or donor registry samples) were gathered and 55 were analysed statistically following HLA‐NET recommendations. The new data included, among others, large sets of well‐defined populations from north‐east Europe and West Asia, as well as many donor registry data from European countries. The Gene[rate] computer tools were combined to create a Gene[rate] computer pipeline to automatically (i) estimate allele frequencies by an expectation‐maximization algorithm accommodating ambiguities, (ii) estimate heterozygosity, (iii) test for Hardy–Weinberg equilibrium (HWE), (iv) test for selective neutrality, (v) generate frequency graphs and summary statistics for each sample at each locus and (vi) plot multidimensional scaling (MDS) analyses comparing the new samples with previous IHIW data. Intrapopulation analyses show that HWE is rarely rejected, while neutrality tests often indicate a significant excess of heterozygotes compared with neutral expectations. The comparison of the 16IHIW AHPD data with data collected during previous workshops (12th–15th) shows that geography is an excellent predictor of HLA genetic differentiations for HLA‐A, ‐B and ‐DRB1 loci but not for HLA‐DQ, whose patterns are probably more influenced by natural selection. In Europe, HLA genetic variation clearly follows a north to south‐east axis despite a low level of differentiation between European, North African and West Asian populations. Pacific populations are genetically close to Austronesian‐speaking South‐East Asian and Taiwanese populations, in agreement with current theories on the peopling of Oceania. Thanks to this project, HLA genetic variation is more clearly defined worldwide and better interpreted in relation to human peopling history and HLA molecular evolution.
Screening of SLC26A4 gene in autoimmune thyroid diseases
Authors: Kallel R. , Niasme‐Grare M. , Belguith‐Maalej S. , Mnif M. , Abid M. , Ayadi H. , Masmoudi S. , Jonard L. , Hadj Kacem H.
Published: December 2012

The Pendred syndrome (PS) gene, SLC26A4, was involved in the genetic susceptibility of autoimmune thyroid disease (AITD) in Tunisian population. Recently, functional assays have shown a differential expression of SLC26A4 gene between Graves’ disease (GD) and Hashimoto's thyroiditis (HT). Here, by the mean of DHPLC and HRM, we explored the 21 exons and their flanking intronic sequences of 128 patients affected with GD (n = 64) or HT (n = 64). The pathogenic effect of identified variations on splice was investigated using the web server HSF. Eighteen allelic variations were identified and ranged on missense, sens and splice variations. Nine identified variations (c.‐66C>G, c.898A>C, c.1002‐9A>C, c.1061T>C, c.1544 + 9G>T, c.1545‐5T>G, c.1790T>C, c.1826T>G, c.2139T>G) were previously reported in hearing impairment studies. Forty‐seven per cent (30/64) of GD patients and 37,5% (24/64) of HT patients present at least one variant in the explored sequences. Moreover, the analysis of the variant distribution between HT (9 (5′UTR), 12 exonic and 13 intronic) and GD (18 (5′UTR), 13 exonic and 5 intronic) patients showed a significant difference (χ² = 6.54, 2df, P = 0.03). Interestingly, missense changes (I300L, p.M283I, F354S and p.L597S) affected conserved residues of pendrin. On the other hand, the HSF analyses ascertain that some variants identified in HT disease are predicted to have a pathogenic effect on splice. In conclusion, our analysis of SLC26A4 sequence variations suggested a distinct genetics basis between HT and GD patients, which should be confirmed on a large cohort.
Patient and visitor assault on nurses and midwives: An exploratory study of employer ‘protective’ factors
Authors: Farrell Gerald A. , Shafiei Touran , Chan Siew‐Pang
Published: December 2012

Most Australian public health‐care services have established a range of initiatives designed to help ‘protect’ nurses and midwives from patient and visitor assault (PVA); however, few studies have specifically examined their effectiveness. The present study is part of a larger survey that explored nurses' and midwives' experiences of PVA using the Department of Human Services, Victoria (2007) definition of occupational violence and bullying. Participants were asked about the presence of ‘protective’ factors in their workplace and the importance of having these factors to prevent and manage workplace aggression. Binary logistic regression was applied to ascertain the association between ‘protective’ factors and the occurrence of PVA, with adjusted odds ratios and their reported 95% confidence intervals for ascertaining the significance of the associations. The study found more ‘protection’ from assault when there was a high standard of patient facilities, sufficient staffing, effective enforcement of policies, and when staff were provided with personal protective equipment. Working in private health care, and being a registered nurse, also conferred ‘protection’. A higher occurrence of staff assault was associated with specific clinical settings, and being on rotation and on night duty. Findings point to important insights into factors associated with ‘protection’ for PVA.
Evaluation of a commercial enzyme‐linked immunosorbent assay for detection of antibodies against the H5 subtype of Influenza A virus in waterfowl
Authors: Lebarbenchon Camille , Pantin‐Jackwood Mary , Kistler Whitney M. , Page Luttrell M. , Spackman Erica , Stallknecht David E. , Brown Justin D.
Published: December 2012

The ID Screen Influenza H5 Antibody Competition enzyme‐linked immunosorbent assay was tested for the detection of antibodies to the H5 subtype of influenza A (IA) virus in waterfowl. Assays were conducted with sera obtained from Mallards (Anas platyrhynchos) and Pekin Ducks (Anas platyrhynchos domestica), experimentally infected with eight low pathogenic (LP) and nine highly pathogenic (HP) H5N1 IA viral strains. Three incubation periods (1, 4 and 18 hours) and two dilutions (1:2 and 1:5) were tested. All serum samples from LP H5‐infected birds tested positive; however, improved detection rates were observed for viruses belonging to the HP H5N1 clade 2.2.1 as compared with those belonging to clade 2.1.3.
Histological effects of occlusive dressing on healing of incisional skin wounds
Authors: Yamamoto Naoto , Kiyosawa Tomoharu
Published: December 2012

Occlusive dressing is widely accepted and used to manage skin ulcers. However, with respect to its application to incisional wounds, most studies have been conducted about the clinical effects on incisional healing of surgical sites. Studies of the histological effects of occlusive dressing for incisional wounds have been few. The aim of this study was to clarify the histological effects of occlusive dressings on healing of incisional skin wounds. Rat dorsal skin was incised down to the panniculus and sutured immediately. Dressing types included 2‐octyl cyanoacrylate and hydrocolloid materials as occlusive dressings and no‐dressing as the open therapy. Histological examination and dermoscopic observation were performed 1, 2, 4 and 7 days after surgery. The findings from each dressing type were compared. In the open therapy group, the upper portion of the edge of incision was necrosed minimally and finally healed with wide scar formation. However, in the occlusive dressing groups, micronecrosis of the incision edge seen in the no‐dressing group was not observed, healing was more rapid and the remaining scar was finer. Occlusive dressing can prevent micronecrosis of the incision edge, resulting in rapid and excellent healing. This study shows that the efficacy of and supports the use of occlusive dressing in incisional wound management.
Scientist or science‐stuffed? Discourses of science in North American medical education
Authors: Whitehead Cynthia
Published: December 2012

Context:  The dominance of biomedical science in medical education has been contested throughout the past century, with recurring calls for more social science and humanities content. The centrality of biomedicine is frequently traced back to Abraham Flexner’s 1910 report, ‘Medical Education in the United States and Canada’. However, Flexner advocated for a scientist‐doctor, rather than a curriculum filled with science content. Examination of the discourses of science since Flexner allows us to explore the place of various knowledge forms in medical education.

Methods:  A Foucauldian critical discourse analysis was performed, examining the discourses of scientific medicine in Flexner’s works and North American medical education articles in subsequent decades. Foucault’s methodological principles were used to identify statements, keywords and metaphors that emerged in the development of the discourses of scientific medicine, with particular attention to recurring arguments and shifts in the meaning and use of terms.

Results:  Flexner’s scientist‐doctor was an incisive thinker who drew upon multiple forms of knowledge. In the post‐Flexner medical education reforms, the perception of science as a discursive object embedded in the curriculum became predominant over that of the scientist as the discursive subject who uses science. Science was then considered core curricular content and was discursively framed as impossibly vast. A parallel discourse, one of the insufficiency of biomedical science for the proper training of doctors, has existed over the past century, even as the humanities and social sciences have remained on the margins in medical school curricula.

Conclusions:  That discourses of scientific medicine have reinforced the centrality of biomedicine in medical education helps to explain the persistent marginalisation of other important knowledge domains. Medical educators need to be aware of the effects of these discourses on understandings of medical knowledge, particularly when contemplating curricular reform.
The consequences of authentic early experience for medical students: creation of mētis
Authors: Yardley Sarah , Brosnan Caragh , Richardson Jane
Published: December 2012

Context  Authentic early experience (AEE) describes experiences provided to new medical students to undertake ‘human contact’ to enhance learning. Although the concept of AEE is not new, and was commonplace prior to the Flexner Report of 1910, little is known about how or why meaning and knowledge are constructed through early student placements in medical, social and voluntary workplaces. Variance among settings means AEE is a collection of non‐uniform, complex educational interventions which require students to make repeated transitions between different workplaces and their university institution. The purpose of this paper is to develop theory in this context.

Methods  We report on a study undertaken in a UK medical school using interviews and discussion groups to generate data from students, workplace supervisors and school faculty staff. We used narrative analysis to access knowledge and meaning construction, in combination with analytic tools drawn from thematic and interpretative approaches to phenomena. We sought to refine theoretical understanding through the application of mētis, a socio‐cultural theory novel to the field of medical education.

Results  Scott’s concept of mētis provides a useful theoretical framework for understanding how AEE works for students in terms of their creation of meaning and how they choose to use it in relation to formally recognised knowledge. Knowledge and meaning, generated as a consequence of AEE, contained dichotomies and paradoxes. Students improvised, in the face of unpredictability and uncertainty, to create a form of mētis that allowed them to handle the perceived competing demands of AEE settings and the medical school.

Discussion  We demonstrate how meaning making can be conceived of as student mētis arising from social processes in students’ learning interactions. We suggest that the development of collaborative working with students could potentiate positive forms of student mētis, thereby maximising desirable educational consequences. Further work is required to establish effective ways to do this.
Nitrogen dynamics in oak model ecosystems subjected to air warming and drought on two different soils
Authors: Kuster T. M. , Schleppi P. , Hu B. , Schulin R. , Günthardt‐Goerg M. S.
Published: December 2012

Being tolerant to heat and drought, oaks are promising candidates for future forestry in view of climate change inCentralEurope. Air warming is expected to increase, and drought decrease soilNavailability and thusNsupply to trees. Here, we conducted a model ecosystem experiment, in which mixed stands of young oaks (Quercus robur,Q. petraeaandQ. pubescens) were grown on two different soils and subjected to four climate treatments during three growing seasons: air warming by 1–2 °C, drought periods (average precipitation reduction of 43–60%), a combination of these two treatments, and a control. In contrast to our hypotheses, neither air warming nor drought significantly affectedNavailability, whereas total amounts, vertical distribution and availability of soilNshowed substantial differences between the two soils. While air warming had no effect on tree growth andNaccumulation, the drought treatment reduced tree growth and increased, or tended to increase,Naccumulation in the reduced biomass, indicating that growth was not limited byN. Furthermore,15N‐labelling revealed that this accumulation was associated with an increased uptake of nitrate. On the basis of our results, climate change effects onNdynamics are expected to be less important in oak stands than reduced soil water availability.
Embryonal rhabdomyosarcoma of the auricle in a child
Authors: Crozier Emily , Rihani Jordan , Koral Korgun , Cope‐Yokoyama Sandy , Rakheja Dinesh , Ulualp Seckin O
Published: December 2012

We describe the diagnosis and management of a child with embryonal rhabdomyosarcoma of the auricle and emphasize both clinical and radiological findings of this rare condition. A nine‐year‐old boy presented for evaluation of a slowly enlarging left auricle mass. The mass was nodular, violaceous, semi‐translucent, and hyperpigmented with an overlying pseudo‐vesicular plaque. The mass appeared to involve the left cavum concha, root of the helix, superior aspect of the external auditory canal, the tragus and extend to a deep preauricular component. MR imaging documented a lobulated soft tissue mass surrounding the external auditory canal with superficial involvement of the pinna. Incisional biopsy of the mass suggested embryonal rhabdomyosarcoma. The tumor was completely removed by total auriculectomy and lateral temporal bone resection. The final diagnosis was embryonal habdomyosarcoma. Although rare, otolaryngologists, pediatricians, and radiologists need to consider rhabdomyosarcoma in the differential diagnosis of auricle mass in children.