bluuebunny/crossref_metadata_2025 huggingface dataset:
Action Mechanisms of the Secondary Metabolite Euplotin C: Signaling and Functional Role in Euplotes
Authors: TRIELLI FRANCESCA , CERVIA DAVIDE , DI GIUSEPPE GRAZIANO , RISTORI CHIARA , KRUPPEL THOMAS , BURLANDO BRUNO , GUELLA GRAZIANO , VIARENGO ALDO , BAGNOLI PAOLA , DELMONTE CORRADO MARIA UMBERTA , DINI FERNANDO
Published: December 2009

ABSTRACT. Among secondary metabolites, the acetylated hemiacetal sesquiterpene euplotin C has been isolated from the marine, ciliated protist Euplotes crassus, and provides an effective mechanism for reducing populations of potential competitors through its cytotoxic properties. However, intracellular signaling mechanisms and their functional correlates mediating the ecological role of euplotin C are largely unknown. We report here that, in E. vannus (an Euplotes morphospecies that does not produce euplotin C and shares with E. crasssus the same interstitial habitat), euplotin C rapidly increases the intracellular concentration of both Ca2+ and Na+, suggesting a generalized effect of this metabolite on cation transport systems. In addition, euplotin C does not induce oxidative stress, but modulates the electrical properties of E. vannus through an increase of the amplitude of graded action potentials. These events parallel the disassembling of the ciliary structures, the inhibition of cell motility, the occurrence of aberrant cytoplasmic vacuoles, and the rapid inhibition of phagocytic activity. Euplotin C also increases lysosomal pH and decreases lysosomal membrane stability of E. vannus. These results suggest that euplotin C exerts a marked disruption of those homeostatic mechanisms whose efficiency represents the essential prerequisite to face the challenges of the interstitial environment.
Factors Controlling the Abundance and Size Distribution of the Phototrophic CiliateMyrionecta rubrain Open Waters of the North Atlantic
Authors: MONTAGNES DAVID J. S. , ALLEN JOHN , BROWN LOUISE , BULIT CELIA , DAVIDSON RUSSELL , DÍAZ‐ÁVALOS CARLOS , FIELDING SOPHIE , HEATH MIKE , HOLLIDAY NAOMI P. , RASMUSSEN JENS , SANDERS RICHARD , WANIEK JOANNA J. , WILSON DAVID
Published: December 2009

ABSTRACT.Myrionecta rubra, a ubiquitous planktonic ciliate, has received much attention due to its wide distribution, occurrence as a red tide organism, and unusual cryptophyte endosymbiont. Although well studied in coastal waters,M. rubrais poorly examined in the open ocean. In the Irminger Basin, North Atlantic, the abundance ofM. rubrawas 0–5 cells/ml, which is low compared with that found in coastal areas. Distinct patchiness (100 km) was revealed by geostatistical analysis. Multiple regression indicated there was little relationship betweenM. rubraabundance and a number of environmental factors, with the exception of temperature and phytoplankton biomass, which influenced abundance in the spring. We also improve on studies that indicate distinct size classes ofM. rubra; we statistically recognise four significantly distinct width classes (5–16, 12–23, 18–27, 21–33 μm), which decrease in abundance with increasing size. A multinomial logistic regression revealed the main variable correlated with this size distribution was ambient nitrate concentration. Finally, we propose a hypothesis for the distribution of sizes, involving nutrients, feeding, and dividing of the endosymbiont.
Active Transport of Glutamate in Leishmania (Leishmania) amazonensis
Authors: PAES LISVANE S. , GALVEZ ROJAS ROBERT L. , DALIRY ANISSA , FLOETER‐WINTER LUCILE M. , RAMIREZ MARCEL I. , SILBER ARIEL M.
Published: December 2009

ABSTRACT. Leishmania spp. are the causative agents of leishmaniasis, a complex of diseases with a broad spectrum of clinical manifestations. Leishmania (Leishmania) amazonensis is a main etiological agent of diffuse cutaneous leishmaniasis. Leishmania spp., as other trypanosomatids, possess a metabolism based significantly on the consumption of amino acids. However, the transport of amino acids in these organisms remains poorly understood with few exceptions. Glutamate transport is an important biological process in many organisms. In the present work, the transport of glutamate is characterized. This process is performed by a single kinetic system (Km=0.59±0.04 mM, Vmax=0.123±0.003 nmol/min per 20 × 106 cells) showing an energy of activation of 52.38±4.7 kJ/mol and was shown to be partially inhibited by analogues, such as glutamine, aspartate, α‐ketoglutarate and oxaloacetate, methionine, and alanine. The transport activity was sensitive to the extracellular concentration of H+ but not to Na+ or K+. However, unlike other amino acid transporters presently characterized, the treatment with specific ionophores confirmed the participation of a K+, and not H+ membrane gradient in the transport process.
Physical and Electrical Properties of Nanosized Mn‐ and Cr‐Doped Strontium Y‐Type Hexagonal Ferrites
Authors: Iqbal Muhammad Javed , Liaqat Faroha
Published: December 2009

Nanometer‐sized crystallites of Y‐type strontium hexaferrite, Sr2Ni2Fe12O22 and its Mn‐ and Cr‐doped derivatives have been synthesized by the sol–gel method. Y‐type phase formation was achieved at a considerably lower temperature of 950°C than is required in the traditional solid‐state method (1200°C). The effect of doping of manganese at the tetrahedral site, Sr2Ni2−xMnx Fe12O22 (x=0.0–2.0), and chromium at octahedral site, Sr2Ni2 Fe12−yCryO22 (y=0.0–1.5), has been studied. The crystal structure remains unaffected by the substitutions. The crystallite size in the range of 13–45 nm is calculated from the X‐ray diffraction data. The energy‐dispersive X‐ray fluorescence analysis shows that Y‐type hexaferrites can be prepared with a base of strontium. The extent of doped Cr+3 ions at the octahedral site has been increased from the reported maximum value of y=1.5. Scanning electron micrographs of the samples showed a homogenous microstructure. The dc electrical resistivity studies show that these hexaferrites exhibit high resistivity at room temperature. Cr‐doped samples have comparatively higher resistivity than Mn‐doped samples. The doubly doped (Cr+Mn) samples possess high resistivity (7.37 × 109Ω‐cm), a low dielectric constant (33.88 at 3000 Hz), and a high Curie temperature (>698 K). The dielectric energy losses are minimized by increasing the Mn and Cr contents of the synthesized samples.
Theoretical Defect Energetics in Calcium Phosphate Bioceramics
Authors: Matsunaga Katsuyuki
Published: December 2009

Vacancies, impurities, and foreign ions dissolving in calcium phosphate bioceramics play an important role in the biological properties of the materials. However, little is known about the thermodynamic stability of the defects. In this regard, point defects in hydroxyapatite (HAp) and octacalcium phosphate (OCP) were calculated in a first‐principles manner, and the chemical‐potential dependence of the defect formation energies was revealed. In particular, because calcium phosphates are usually subjected to an aqueous solution, a methodology to evaluate ionic chemical potentials under chemical equilibrium of the solid–aqueous solution was introduced. In the present article, recent results based on such a methodology (the solution pH dependence of Ca/P molar ratio of HAp and the ion‐exchange ability with foreign cations in HAp and OCP) were reviewed.
Periodontal health in children exposed to passive smoking
Authors: Erdemir Ebru Olgun , Sönmez Işıl Saroǧlu , Oba Aylin Akbay , Bergstrom Jan , Çaǧlayan Osman
Published: December 2009

Erdemir EO, Sönmez IS, Oba AA, Bergstrom J, Çaǧlayan O. Periodontal health in children exposed to passive smoking. J Clin Periodontol 2010; 37: 160–164. doi: 10.1111/j.1600‐051X.2009.01510.x.

Aim: To determine (1) the cotinine levels of saliva, urine and gingival crevicular fluid (GCF) of children in families with and without smoking members and (2) a possible association between the periodontal health of the children and exposure to passive smoking.

Material and Methods: The study population comprised of 109 children in the age range 6–12 years. Children were classified as exposed to passive tobacco smoking (PTS‐exposed, n=51) and as unexposed controls (PTS‐unexposed, n=58). Plaque index, gingival index, bleeding on probing, probing depth and clinical attachment level (CAL) were recorded. GCF, saliva and urine samples were also collected. The levels of cotinine in these fluids were determined by enzyme‐linked immunosorbent assay.

Results: The mean salivary cotinine concentration was significantly increased in PTS‐exposed children compared with PTS‐unexposed children (p<0.05). Further, in a dose‐dependent way, the mean salivary concentration was significantly higher in children whose father or mother was a smoker (p<0.05) as compared, respectively, with children whose fathers and mothers were non‐smokers. The mean CAL was significantly less in PTS‐exposed children compared with non‐PTS‐exposed children (0.09 mm; p<0.05) and also in children whose father was a smoker (p<0.05), but not in children whose mother was a smoker as compared with non‐smoker fathers and mothers, respectively. The GCF cotinine levels were below the detection limits with the assay method that was used.

Conclusions: We have observed that children who are exposed to passive smoking have elevated cotinine levels in their saliva concomitant with a lowered CAL.
Visceral fat area‐defined obesity and periodontitis among Koreans
Authors: Han Dong‐Hun , Lim Sin‐Ye , Sun Bo‐Cheng , Paek Do‐Myung , Kim Hyun‐Duck
Published: December 2009

Han D‐H, Lim S‐Y, Sun B‐C, Paek D‐M, Kim H‐D. Visceral fat area defined obesity and periodontitis among Koreans. J Clin Periodontol 2010; 37: 172–179. doi: 10.1111/j.1600‐051X.2009.01515.x.

Aim: Although the association of periodontitis with body mass index (BMI)‐defined obesity has been studied, it remains controversial. Hence, this study aims to determine whether the obesity is associated with periodontitis among Koreans and to determine the most significant indicator of the obesity on the link.

Materials and Methods: From the Sihwa–Banwol Environmental Health Cohort, 1046 subjects 15 years of age or older were cross‐sectionally surveyed. All participants underwent periodontal and medical health examinations. Age, gender, monthly family income, smoking, drinking, frequency of daily teeth brushing and physical activity were evaluated through interviews. The community periodontal index (CPI) was used to assess periodontitis. BMI, waist circumference (WC), waist hip ratio and visceral fat area (VFA) were used to assess obesity. Multivariate linear and logistic regression analyses were applied.

Results: BMI, WC and VFA had a dose–effect relationship with the number of sextants with periodontitis. Although subgroup analysis revealed several significant associations between obesity and periodontitis (CPI 3–4), the greatest association between VFA and periodontitis was found in males, age 45–54 (odds ratio=3.30; 95% confidence interval: 1.53–7.09).

Conclusions: Obesity was associated with periodontitis. VFA was the most suitable indicator of obesity in relation to periodontitis. Obesity may be a substantial risk factor for periodontitis.
Effect of hot‐water treatments in vitro on conidial germination and mycelial growth of grapevine trunk pathogens
Authors: Gramaje D. , Alaniz S. , Abad‐Campos P. , García‐Jiménez J. , Armengol J.
Published: December 2009

In this study, the sensitivity of Cadophora luteo‐olivacea, Cylindrocarpon liriodendri, Cn. macrodidymum and eight species of the genus Phaeoacremonium to hot‐water treatments (HWTs) in vitro was evaluated. Conidial suspensions and plugs of agar with mycelia were placed in Eppendorf vials and incubated for 30, 45 or 60 min in a hot‐water bath at 41, 42, 43, 44, 45, 46, 47, 48 or 49°C for Cylindrocarpon spp. and at 49, 50, 51, 52, 53, 54 or 55°C for Ca. luteo‐olivacea and Phaeoacremonium spp. In general, conidial germination and the colony growth rate of all pathogens decreased with increased temperature and time combinations. Cylindrocarpon spp. were more sensitive than Ca. luteo‐olivacea and Phaeoacremonium spp. to HWT temperatures. Conidial germination of Ca. luteo‐olivacea was inhibited by treatments above 51°C–30 min, while treatments up to 54°C–60 min were necessary to inhibit the mycelial growth. For Cylindrocarpon spp., conidial germination was inhibited by treatments above 45°C–45 min, while treatments above 48°C–45 min were necessary to inhibit the mycelial growth. Regarding Phaeoacremonium spp., treatments up to 54°C–60 min were necessary to completely inhibit both conidial germination and mycelial growth. These results suggest that current HWT protocols at 50°C for 30 min may be sufficient to control Cylindrocarpon spp. However, it would be necessary to develop HWT using higher temperatures to reduce the incidence of Ca. luteo‐olivacea and Phaeoacremonium spp. infections.
Factors Affecting the Distribution and Abundance of Asplenium nidus L. in a Tropical Lowland Rain Forest in Peninsular Malaysia
Authors: Zhang Liwen , Nurvianto Sandy , Harrison Rhett
Published: December 2009

Asplenium nidus is an abundant epiphytic fern of tropical rain forests in the Old World, where it plays an important ecological role in the forest canopy as host to diverse arthropod communities. We investigated the factors that determine the distribution and abundance of A. nidus in the canopy of an aseasonal lowland dipterocarp forest at Pasoh Forest Reserve, Malaysia. We found that A. nidus was more abundant in the understory, and on hosts with smooth bark and relatively flat branch angles. Ferns were found on a wide diversity and size range of host taxa. However, both host taxa and host diameter at breast height had a significant effect on A. nidus occupancy. Asplenium nidus had an aggregated spatial distribution at all scales within the study area. Spatial aggregation at larger scales appears to be driven by habitat preference, as A. nidus abundance was positively associated with swampy areas and negatively associated with hilly areas. At smaller scales, limited dispersal of their wind‐dispersed spores most likely explains the aggregated distribution. Larger individuals occurred higher in the canopy and were more common in the hilly area. Thus, the distribution of A. nidus may represent a trade‐off between the availability of suitable microsites for establishment in the understory and better growth conditions higher in the canopy. However, A. nidus is known to comprise a complex of cryptic species, and future studies should incorporate molecular techniques to elucidate the potential role of speciation in explaining these patterns.
Supercollapsars and their X-ray bursts
Authors: Komissarov Serguei S. , Barkov Maxim V.
Published: December 2009

The very first stars in the Universe can be very massive, up to 103 M⊙. If born in large numbers, such massive stars can have a strong impact on the subsequent star formation, producing strong ionizing radiation and contaminating the primordial gas with heavy elements. They would leave behind massive black holes that could act as seeds for growing supermassive black holes of active galactic nuclei. Given the anticipated fast rotation, such stars would end their life as supermassive collapsars and drive powerful magnetically dominated jets. In this Letter, we investigate the possibility of observing the bursts of high-energy emission similar to the long gamma-ray bursts associated with normal collapsars. We show that during the collapse of supercollapsars, the Blandford–Znajek mechanism can produce jets as powerful as few ×1052 erg s−1 and release up to 1054 erg of the black hole rotational energy. Due to the higher intrinsic time-scale and higher redshift, the initial bright phase of the burst can last for about 104 s, whereas the central engine would remain active for about 1 d. Due to the high redshift the burst spectrum is expected to be soft, with the spectral energy distribution peaking at around 20–30 keV. The peak total flux density is relatively low, 10−7 erg cm−2 s−1, but not prohibitive. If one supercollapsar is produced per every minihalo of dark matter arising from the 3σ cosmological fluctuations, then the whole sky frequency of such bursts could reach several tens per year.
Abell 370 revisited: refurbished Hubble imaging of the first strong lensing cluster
Authors: Richard J. , Kneib J.-P. , Limousin M. , Edge A. , Jullo E.
Published: December 2009

We present a strong lensing analysis of the galaxy cluster Abell 370 (z= 0.375) based on the recent multicolour images by Advanced Camera for Surveys obtained as part of the Early Release Observation (ERO) that followed the Hubble Service Mission #4. Back in 1987, the giant gravitational arc (z= 0.725) in Abell 370 was one of the first pieces of evidence that massive clusters are dense enough to act as strong gravitational lenses. The new observations reveal in detail its disclike morphology, and we show that it can be interpreted as a complex five-image configuration, with a total magnification factor of 32 ± 4. Moreover, the high-resolution multicolour information allowed us to identify 10 multiply imaged background galaxies. We derive a mean Einstein radius of θE= 39 ± 2 arcsec for a source redshift at z= 2, corresponding to a mass of M(<θE) = 2.82 ± 0.15 × 1014 M⊙ and M(<250 kpc) = 3.8 ± 0.2 × 1014 M⊙, in good agreement with Subaru weak-lensing measurements. The typical mass model error is smaller than 5 per cent, a factor of 3 of improvement compared to the previous lensing analysis. Abell 370 mass distribution is confirmed to be bimodal with very small offset between the dark matter, the X-ray gas and the stellar mass. Combining this information with the velocity distribution reveals that Abell 370 is likely the merging of two equally massive clusters along the line of sight, explaining the very high-mass density necessary to efficiently produce strong lensing. These new observations stress the importance of multicolour imaging for the identification of multiple images which is key to determining an accurate mass model. The very large Einstein radius makes Abell 370 one of the best clusters to search for high-redshift galaxies through strong magnification in the central region.
Predicting business unit performance using employee surveys: monitoring HRM‐related changes
Authors: Van De Voorde Karina , Paauwe Jaap , Van Veldhoven Marc
Published: December 2009

Organisations are increasingly using strategy tools such as workforce scorecards to keep track of human resource management related change processes that have been implemented and the effects of these on business unit performance. However, in this area, the challenge of finding appropriate indicators, establishing temporal relationships and providing useful management information still remains. Using longitudinal archival data from 171 branches of a large financial service organisation, this study examines to what extent employee surveys can serve as a predictor of better financial performance at the branch level. Results from a series of models in AMOS (Analysis of Moment Structures) showed that a significant part of branch profits could be predicted using employee surveys after correcting for prior profits. Based on extrapolation to all branches of this organisation, the changes in employee survey scores predict higher yearly profits of 178 million euros (17.9 per cent of the total yearly profits) across the entire company. Implications for research and practice are discussed.
Employee voice: does union membership matter?
Authors: Benson John , Brown Michelle
Published: December 2009

Industrial relations research has traditionally viewed trade unions as the primary mechanism for employee voice. With the decline in unionism in many advanced industrial economies over the past two decades, new direct non‐union voice mechanisms have been introduced by employers. This focus on the mechanisms for employee voice, however, fails to take account of employees' perceptions of voice. We suggested that employee perceptions of voice vary between the different levels of an organisation and proposed that trade union membership will be more likely to enhance individual employee perceptions of voice at the wider organisational level. Contrary to our expectations, our analysis of 2,949 employees of a public sector scientific research organisation found that union membership had a significant negative impact on employee voice at the organisational level. The article concluded by offering possible explanations for this unexpected finding and the implications for theory, management and future research.
Simultaneous Spectrophotometric Determination of 2‐Thiouracil and 2‐Mercaptobenzimidazole in Animal Tissue Using Multivariate Calibration Methods: Concerns and Rapid Methods for Detection
Authors: Beheshti Abolghasem , Riahi Siavash , Pourbasheer Eslam , Ganjali Mohammad Reza , Norouzi Parviz
Published: December 2009

ABSTRACT:  Two multivariate calibration methods, partial least squares (PLS) and principal component regression (PCR), were applied to the spectrophotometric simultaneous determination of 2‐mercaptobenzimidazole (MB) and 2‐thiouracil (TU). A genetic algorithm (GA) using partial least squares was successfully utilized as a variable selection method. The concentration model was based on the absorption spectra in the range of 200 to 350 nm for 25 different mixtures of MB and TU. The calibration curve was linear across the concentration range of 1 to 10 μg mL−1 and 1.5 to 15 μg mL−1 for MB and TU, respectively. The values of the root mean squares error of prediction (RMSEP) were 0.3984, 0.1066, and 0.0713 for MB and 0.2010, 0.1667, and 0.1115 for TU, which were obtained using PCR, PLS, and GA‐PLS, respectively. Finally, the practical applicability of the GA‐PLS method was effectively evaluated by the concurrent detection of both analytes in animal tissues. It should also be mentioned that the proposed method is a simple and rapid way that requires no preliminary separation steps and can be used easily for the analysis of these compounds, especially in quality control laboratories.
Composition and Oxidative Stability of a Structured Lipid from Amaranth Oil in a Milk‐Based Infant Formula
Authors: Pina‐Rodriguez Ashanty M. , Akoh Casimir C.
Published: December 2009

ABSTRACT:  Amaranth oil can be enzymatically modified to match breast milk fat analog requirements. We have developed a structured lipid (SL) from amaranth oil that, in combination with milk fat, delivers recommended amounts of docosahexaenoic acid (DHA) with palmitic acid specifically esterified at the sn‐2 position of the triacylglycerol (TAG) backbone. The aim of this study was to study the final fatty acid (FA) contribution and oxidation stability of an infant formula prepared using the structured lipid DCAO (DHA‐containing customized amaranth oil). DCAO was included as complementary fat in a “prototype” infant formula, and prepared in parallel with a “control” infant formula under the same processing conditions. The same ingredients but different complementary fat sources were used. A blend of the most commonly used vegetable oils (palm olein, soybean, coconut, and high‐oleic sunflower oils) for infant formula was used instead of DCAO in the “control” formula. Additionally, “prototype” and “control” infant formulas were compared to a “commercial” product in terms of FA composition. The oxidative stability index (OSI) of the extracted fats from “prototype,”“control,” and “commercial” infant formulas were evaluated and compared to the OSI of the substrate fat replacers used. DCAO was the least stable compared to other fat analogs. The use of commercial antioxidants in DCAO containing products should prevent oxidation and therefore increase their stability.
Increases of 2‐Furanmethanol and Maltol in Korean Red Ginseng during Explosive Puffing Process
Authors: Lee Sang‐Jun , Moon Tae Wha , Lee JaeHwan
Published: December 2009

ABSTRACT:  The explosive puffing process may provide characteristic physicochemical properties in red ginseng. The effects of explosive puffing on the changes of volatiles in red ginseng were investigated using headspace‐solid phase microextraction (HS‐SPME)‐gas chromatograph (GC) with a mass selective detector (MS). Formation of porous structures and smaller pieces were clearly observed on the surface of puffed red ginseng by scanning electron microscopy. Total volatiles in puffed red ginseng increased by 87% compared to those in red ginseng. Hexanal, Δ‐selinene, and β‐panasinsene were major volatiles in red ginseng, whereas aristolene, β‐panasinsene, and calarene were main volatiles in puffed red ginseng. Puffing process decreased volatiles from lipid oxidation including aldehydes, ketones, and 2‐pentylfuran and increased terpenoids in red ginseng. Selective ion monitoring (SIM) mode for GC/MS results showed that 2‐furanmethanol and maltol were present at the concentrations of 0.20% and 0.24%, respectively, in red ginseng and 5.86% and 3.99%, respectively, in puffed red ginseng. The explosive puffing process increased 2‐furanmethanol and maltol in puffed red ginseng significantly (P < 0.05) with the changes of microstructures.
Medievalism, Popular Culture and National Identity in Children's Fantasy Literature
Authors: Cecire Maria Sachiko
Published: December 2009

This article introduces the role of medievalisms in British and Anglophone children's fantasy literature since the 1950s, focusing on how these texts impact the development of national identity. Children's fantasy literature often contributes to a nationalistic tradition of nostalgia for the Middle Ages, glorifying and reproducing that period for contemporary readers by including medieval narratives and what Clare A. Simmons calls ‘perceived codes of values’, as well as the customary medievalised trappings: castles, knights, magicians, etc. However, in the face of globalisation, recent fantasy has begun to reflect changes in the British experience of itself and the outside world. The explosive popularity of J.K. Rowling's Harry Potter novels and the subsequent rise of other new fantasy for children have placed these new forms of medievalism on a global stage through wide translation, spin‐off media and merchandise. This article is especially concerned with how these texts balance questions of racial and spatial relationships to establish insider identity for their young readers.
Rescaling Regional Identities: Communicating Thick and Thin Regional Identities
Authors: Terlouw Kees
Published: December 2009

Novel forms of regional identities emerge in response to global competitive pressures and challenges to the nation‐state. Regions have to react and position their identity in relation to the rescaling of statehood. Especially, the growing autonomy of regional administrations makes support from local stakeholders more important. Communicating a specific regional identity is one of the instruments regional administrations use for mobilising support. However, at the same time old, traditional regional identities become more fluid. Regional identity traditionally focuses on shared past and specific social and cultural characteristics. Especially globalisation and individualisation undermine this traditional thick regional identity. Regional administrations have to adjust their communicated regional identity. By communicating the image of a future oriented region that can face the challenges of global competition, they increasingly use a thin regional identity. This paper analyses different case studies from the Netherlands and Germany.
Reproducibility of retinal thickness measurements in patients with age‐related macular degeneration using 3D Fourier‐domain optical coherence tomography (OCT) (Topcon 3D‐OCT 1000)
Authors: Menke Marcel N. , Dabov Simeon , Knecht Pascal , Sturm Veit
Published: December 2009

Purpose:  Conventional time‐domain optical coherence tomography (OCT) has become an important tool for following dry or exudative age‐related macular degeneration (AMD). Fourier‐domain three‐dimensional (3D) OCT was recently introduced. This study tested the reproducibility of 3D‐OCT retinal thickness measurements in patients with dry and exudative AMD.

Methods:  Ten eyes with dry AMD and 12 eyes with exudative AMD were included in the study. Sets of three OCT 6 × 6‐mm raster scans were taken by one operator. Mean retinal thickness was calculated for 36 areas. Coefficients of variation (CoV) were calculated for each patient and area. For analysis, two separate areas (central and peripheral) were defined. Generalized estimating equations (GEEs) were applied to all 36 subfields in order to analyse possible differences in CoV and mean retinal thickness between dry and exudative AMD.

Results:  Mean retinal thickness values were significantly larger in the central area in exudative AMD (p < 0.001). Mean CoV for exudative AMD was 3.7% (standard deviation [SD] 1.4%). Mean CoV for dry AMD was 1.8 (SD 0.6%). The reproducibility of retinal thickness measurements was significantly less in exudative AMD (p = 0.009).

Conclusions:  Reproducibility of 3D‐OCT retinal thickness measurements was good in both groups. However, reproducibility was significantly better in dry AMD than in exudative AMD.
Polarized endomorphisms of uniruled varieties. With an appendix by Y. Fujimoto and N. Nakayama
Authors: Zhang De-Qi
Published: December 2009

We show that polarized endomorphisms of rationally connected threefolds with at worst terminal singularities are equivariantly built up from those on ℚ-Fano threefolds, Gorenstein log del Pezzo surfaces and ℙ1. Similar results are obtained for polarized endomorphisms of uniruled threefolds and fourfolds. As a consequence, we show that every smooth Fano threefold with a polarized endomorphism of degree greater than one is rational.
High power impulse magnetron sputtering using a rotating cylindrical magnetron
Authors: Leroy W. P. , Mahieu S. , Depla D. , Ehiasarian A. P.
Published: December 2009

Both the industrially favorable deposition technique, high power impulse magnetron sputtering (HIPIMS), and the industrially popular rotating cylindrical magnetron have been successfully combined. A stable operation without arcing, leaks, or other complications for the rotatable magnetron was attained, with current densities around 11 A cm−2. For Ti and Al, a much higher degree in ionization in the plasma region was observed for the HIPIMS mode compared to the direct current mode.
The Lichen-GIS Project, Teaching Students How to Use Bioindicator Species to Assess Environmental Quality
Authors: Wagner Stephen C. , McDonald Darrel , Watson Trey , Taylor Josephine , Sowards Alan B.
Published: December 2009

A content-driven biology course for preservice K-8 teachers has been developed. This course uses the constructivist approach, where instructors engage students by organizing information around concept-based problems. To this end, a semester-long, inquiry-based project was introduced where students studied lichen populations on trees located on their campus to monitor air quality. Data were incorporated into a geographical information systems (GIS) database to demonstrate how it can be used to map communities. Student teams counted the number of each lichen type within a grid placed on each tree trunk sampled and entered this information into a GIS database. The students constructed maps of lichen populations at each sample site and wrote abstracts about their research. Student performance was assessed by the preparation of these abstracts as well as by scores on pre- and posttests of key content measures. Students also completed a survey to determine whether the project aided in their comprehension as well as their interest in incorporating this activity into their own curricula. The students’ pre- and posttest results showed an eightfold improvement in the total score after the semester project. Additionally, correct responses to each individual content measure increased by at least 35%. Total scores for the abstract ranged from 12 to 20 points out of 20 total points possible (60% to 100%), with a mean score of 15.8 points (78%). These results indicate that this exercise provided an excellent vehicle to teach students about lichens and their use as bioindicators and the application of geospatial technologies to map environmental data.
The Use of Interrupted Case Studies to Enhance Critical Thinking Skills in Biology
Authors: White Tracy K. , Whitaker Paul , Gonya Terri , Hein Richard , Kroening Dubear , Lee Kevin , Lee Laura , Lukowiak Andrea , Hayes Elizabeth
Published: December 2009

There has been a dramatic increase in the availability of case studies for use in the biology classroom, and perceptions of the effectiveness of case-study-based learning are overwhelmingly positive. Here we report the results of a study in which we evaluated the ability of interrupted case studies to improve critical thinking in the context of experimental design and the conventions of data interpretation. Students were assessed using further case studies designed to evaluate their ability to recognize and articulate problematic approaches to these elements of experimentation. Our work reveals that case studies have broad utility in the classroom. In addition to demonstrating a small but statistically significant increase in the number of students capable of critically evaluating selected aspects of experimental design, we also observed increased student engagement and documented widespread misconceptions regarding the conventions of data acquisition and analysis.
Assessing Student Understanding of Host Pathogen Interactions Using a Concept Inventory
Authors: Marbach-Ad Gili , Briken Volker , El-Sayed Najib M. , Frauwirth Kenneth , Fredericksen Brenda , Hutcheson Steven , Gao Lian-Yong , Joseph Sam , Lee Vincent T. , McIver Kevin S. , Mosser David , Quimby B. Booth , Shields Patricia , Song Wenxia , Stein Daniel C. , Yuan Robert T. , Smith Ann C.
Published: December 2009

As a group of faculty with expertise and research programs in the area of host-pathogen interactions (HPI), we are concentrating on students’ learning of HPI concepts. As such we developed a concept inventory to measure level of understanding relative to HPI after the completion of a set of microbiology courses (presently eight courses). Concept inventories have been useful tools for assessing student learning, and our interest was to develop such a tool to measure student learning progression in our microbiology courses. Our teaching goal was to create bridges between our courses which would eliminate excessive overlap in our offerings and support a model where concepts and ideas introduced in one course would become the foundation for concept development in successive courses. We developed our HPI concept inventory in several phases. The final product was an 18-question, multiple-choice concept inventory. In fall 2006 and spring 2007 we administered the 18-question concept inventory in six of our courses. We collected pre- and postcourse surveys from 477 students. We found that students taking pretests in the advanced courses retained the level of understanding gained in the general microbiology prerequisite course. Also, in two of our courses there was significant improvement on the scores from pretest to posttest. As we move forward, we will concentrate on exploring the range of HPI concepts addressed in each course and determine and/or create effective methods for meaningful student learning of HPI aspects of microbiology.
Virtual Lab Demonstrations Improve Students’ Mastery of Basic Biology Laboratory Techniques
Authors: Maldarelli Grace A. , Hartmann Erica M. , Cummings Patrick J. , Horner Robert D. , Obom Kristina. M. , Shingles Richard , Pearlman Rebecca S.
Published: December 2009

Biology laboratory classes are designed to teach concepts and techniques through experiential learning. Students who have never performed a technique must be guided through the process, which is often difficult to standardize across multiple lab sections. Visual demonstration of laboratory procedures is a key element in teaching pedagogy. The main goals of the study were to create videos explaining and demonstrating a variety of lab techniques that would serve as teaching tools for undergraduate and graduate lab courses and to assess the impact of these videos on student learning. Demonstrations of individual laboratory procedures were videotaped and then edited with iMovie. Narration for the videos was edited with Audacity. Undergraduate students were surveyed anonymously prior to and following screening to assess the impact of the videos on student lab performance by completion of two Participant Perception Indicator surveys. A total of 203 and 171 students completed the pre- and posttesting surveys, respectively. Statistical analyses were performed to compare student perceptions of knowledge of, confidence in, and experience with the lab techniques before and after viewing the videos. Eleven demonstrations were recorded. Chi-square analysis revealed a significant increase in the number of students reporting increased knowledge of, confidence in, and experience with the lab techniques after viewing the videos. Incorporation of instructional videos as prelaboratory exercises has the potential to standardize techniques and to promote successful experimental outcomes.
Whole Genome Sequencing in the Undergraduate Classroom: Outcomes and Lessons from a Pilot Course
Authors: Drew Jennifer C. , Triplett Eric W.
Published: December 2009

The BIO2010 report challenged undergraduate institutions to prepare the next generation of researchers for the changing direction of biology that increasingly integrates advanced technologies, digital information, and large-scale analyses. In response, the Microbiology and Cell Science Department at the University of Florida developed a research-based course, “Bacterial Genome Sequencing.” The objectives were to teach undergraduates about genomics and original research by sequencing a bacterial genome, to develop scientific communication skills by writing and submitting the project results as a class effort, and to promote an interest in biological research, particularly genomics. The students worked together to sequence, assemble, and annotate the
Enterobacter cloacae
P101 genome. We assessed student learning, scientific communication skills, and student attitudes by a variety of methods including exams, writing assignments, oral presentations, pre- and postcourse surveys, and a final exit survey. Assessment results demonstrate student learning gains and positive attitudes regarding the course.
HLA and kidney transplantation
Authors: Clark B , Unsworth D J
Published: December 2009

This article focuses on the immunogenetics, immunology, rejection and immunosuppression in kidney transplantation. HLA matching still affects outcome data, and HLA matching improves graft survival. Graft sources and related outcomes are discussed.
“It’s crucial they’re treated as patients”: ethical guidance and empirical evidence regarding treating doctor–patients
Authors: Fox F E , Taylor G J , Harris M F , Rodham K J , Sutton J , Scott J , Robinson B
Published: December 2009

Ethical guidance from the British Medical Association (BMA) about treating doctor–patients is compared and contrasted with evidence from a qualitative study of general practitioners (GPs) who have been patients. Semistructured interviews were conducted with 17 GPs who had experienced a significant illness. Their experiences were discussed and issues about both being and treating doctor–patients were revealed. Interpretative phenomenological analysis was used to evaluate the data. In this article data extracts are used to illustrate and discuss three key points that summarise the BMA ethical guidance, in order to develop a picture of how far experiences map onto guidance. The data illustrate and extend the complexities of the issues outlined by the BMA document. In particular, differences between experienced GPs and those who have recently completed their training are identified. This analysis will be useful for medical professionals both when they themselves are unwell and when they treat doctor–patients. It will also inform recommendations for professionals who educate medical students or trainees.
An investigation of patients’ motivations for their participation in genetics-related research
Authors: Hallowell N , Cooke S , Crawford G , Lucassen A , Parker M , Snowdon C
Published: December 2009

Design:

Qualitative interview study.

Participants:

Fifty-nine patients with a family history of cancer who attend a regional cancer genetics clinic in the UK were interviewed about their current and previous research experiences.

Findings:

Interviewees gave a range of explanations for research participation. These were categorised as (a) social—research participation benefits the wider society by progressing science and improving treatment for everyone; (b) familial—research participation may improve healthcare and benefit current or future generations of the participant’s family; and (c) personal—research participation provides therapeutic or non-therapeutic benefits for oneself.

Conclusions:

We discuss the distinction drawn between motives for research participation focused upon self (personal) and others (familial/social), and observe that personal, social and familial motives can be seen as interdependent. For example, research participation that is undertaken to benefit others, particularly relatives, may also offer a number of personal benefits for self, such as enabling participants to feel that they have discharged their social or familial obligations. We argue for the need to move away from simple, static, individualised notions of research participation to a more complex, dynamic and inherently social account.
Physicians’ labelling of end-of-life practices: a hypothetical case study
Authors: Buiting H M , van der Heide A , Onwuteaka-Philipsen B D , Rurup M L , Rietjens J A C , Borsboom G , van der Maas P J , van Delden J J M
Published: December 2009

Objectives:

To investigate why physicians label end-of-life acts as either ‘euthanasia/ending of life’ or ‘alleviation of symptoms/palliative or terminal sedation’, and to study the association of such labelling with intended reporting of these acts.

Methods:

Questionnaires were sent to a random, stratified sample of 2100 Dutch physicians (response: 55%). They were asked to label six hypothetical end-of-life cases: three ‘standard’ cases and three cases randomly selected (out of 47), that varied according to (1) type of medication, (2) physician’s intention, (3) type of patient request, (4) patient’s life expectancy and (5) time until death. We identified the extent to which characteristics of cases are associated with physician’s labelling, with multilevel multivariable logistic regression.

Results:

The characteristics that contributed most to labelling cases as ‘euthanasia/ending of life’ were the administration of muscle relaxants (99% of these cases were labelled as ‘euthanasia/ending of life’) or disproportional morphine (63% of these cases were labelled accordingly). Other important factors were an intention to hasten death (54%) and a life expectancy of several months (46%). Physicians were much more willing to report cases labelled as ‘euthanasia’ (87%) or ‘ending of life’ (56%) than other cases.

Conclusions:

Similar cases are not uniformly labelled. However, a physicians’ label is strongly associated with their willingness to report their acts. Differences in how physicians label similar acts impede complete societal control. Further education and debate could enhance the level of agreement about what is physician-assisted dying, and thus should be reported, and what not.
The role of ‘public opinion’ in the UK animal research debate
Authors: Hobson-West P
Published: December 2009

Animal research remains a deeply controversial topic in biomedical science. While a vast amount has been written about the ethical status of laboratory animals, far less academic attention has been devoted to the public and, more specifically, to public opinion. Rather thanwhatthe public think, this article considersthe roleof ‘public opinion’. It draws on a recent empirical study which involved interviews with laboratory scientists who use animals in their research, and with other UK stakeholders. The first section of the paper demonstrates that public opinion has become a kind of resource in the animal research debate. Public opinion polls, in particular, are frequently cited. The second section explores this further and argues that, for all sides, appealing to public opinion is a key way to show legitimacy. Finally, the paper shifts gear to consider whether public opinion should matter, both for ethical reasoning and for science policy.
Payment for participation in research: a pursuit for the poor?
Authors: Stones M , McMillan J
Published: December 2009

Poor people predominate as a subgroup of those who take part in healthy volunteer research. They are subjected to minimised but unknown risks and unpleasant burdens so that the safety of new medicines can be evaluated. This is prima facie unfair especially given that the poor are often unable to access expensive medicines. Although participants in this kind of research often do receive compensation for their time, these payments are usually capped at a very low level. This paper defends a version of a reimbursement model for the payment of research subjects. This model is practical, would benefit those without an income who take part in research, and would make it possible for those in regular work to take part in phase 1 research.
Healthcare workers’ perceptions of the duty to work during an influenza pandemic
Authors: Damery S , Draper H , Wilson S , Greenfield S , Ives J , Parry J , Petts J , Sorell T
Published: December 2009

Healthcare workers (HCWs) are often assumed to have a duty to work, even if faced with personal risk. This is particularly so for professionals (doctors and nurses). However, the health service also depends on non-professionals, such as porters, cooks and cleaners. The duty to work is currently under scrutiny because of the ongoing challenge of responding to pandemic influenza, where an effective response depends on most uninfected HCWs continuing to work, despite personal risk. This paper reports findings of a survey of HCWs (n = 1032) conducted across three National Health Service trusts in the West Midlands, UK, to establish whether HCWs’ likelihood of working during a pandemic is associated with views about the duty to work. The sense that HCWs felt that they had a duty to work despite personal risk emerged strongly regardless of professional status. Besides a strong sense that everyone should pull together, all kinds of HCWs recognised a duty to work even in difficult circumstances, which correlated strongly with their stated likelihood of working. This suggests that HCWs’ decisions about whether or not they are prepared to work during a pandemic are closely linked to their sense of duty. However, respondents’ sense of the duty to work may conflict with their sense of duty to family, as well as other factors such as a perceived lack of reciprocity from their employers. Interestingly, nearly 25% of doctors did not consider that they had a duty to work where doing so would pose risks to themselves or their families.