bluuebunny/crossref_metadata_2025 huggingface dataset:
Random Graph Dynamics
Authors: Durrett Rick
Published: December 2009

The theory of random graphs began in the late 1950s in several papers by Erdos and Renyi. In the late twentieth century, the notion of six degrees of separation, meaning that any two people on the planet can be connected by a short chain of people who know each other, inspired Strogatz and Watts to define the small world random graph in which each site is connected to k close neighbors, but also has long-range connections. At a similar time, it was observed in human social and sexual networks and on the Internet that the number of neighbors of an individual or computer has a power law distribution. This inspired Barabasi and Albert to define the preferential attachment model, which has these properties. These two papers have led to an explosion of research. The purpose of this book is to use a wide variety of mathematical argument to obtain insights into the properties of these graphs. A unique feature is the interest in the dynamics of process taking place on the graph in addition to their geometric properties, such as connectedness and diameter.
The Mountain Pass Theorem
Authors: Jabri Youssef
Published: December 2009

This 2003 book presents min-max methods through a study of the different faces of the celebrated Mountain Pass Theorem (MPT) of Ambrosetti and Rabinowitz. The reader is led from the most accessible results to the forefront of the theory, and at each step in this walk between the hills, the author presents the extensions and variants of the MPT in a complete and unified way. Coverage includes standard topics, but it also covers other topics covered nowhere else in book form: the non-smooth MPT; the geometrically constrained MPT; numerical approaches to the MPT; and even more exotic variants. Each chapter has a section with supplementary comments and bibliographical notes, and there is a rich bibliography and a detailed index to aid the reader. The book is suitable for researchers and graduate students. Nevertheless, the style and the choice of the material make it accessible to all newcomers to the field.
Abiotic versus biotic hierarchies in the assembly of parasite populations
Authors: ANDERSON T. K. , SUKHDEO M. V. K.
Published: December 2009

The presence or absence of parasites within host populations is the result of a complex of factors, both biotic and abiotic. This study uses a non-parametric classification tree approach to evaluate the relative importance of key abiotic and biotic drivers controlling the presence/absence of parasites with complex life cycles in a sentinel, the common killifishFundulus heteroclitus. Parasite communities were classified from 480 individuals representing 15 fish from 4 distinct marsh sites in each of 4 consecutive seasons between 2006 and 2007. Abiotic parameters were recorded at continuous water monitoring stations located at each of the 4 sites. Classification trees identified the presence of benthic invertebrate species (Gammarussp. andLittorinasp.) as the most important variables in determining parasite presence: secondary splitters were dominated by abiotic variables including conductance, pH and temperature. Seventy percent of hosts were successfully classified into the correct category (infected/uninfected) based on only these criteria. The presence of competent definitive hosts was not considered to be an important explanatory variable. These data suggest that the most important determinant of the presence of these parasite populations in the common killifish is the availability of diverse communities of benthic invertebrates.
How similar are adult second language learners and Spanish heritage speakers? Spanish clitics and word order
Authors: MONTRUL SILVINA
Published: December 2009

Recent studies of heritage speakers, many of whom possess incomplete knowledge of their family language, suggest that these speakers may be linguistically superior to second language (L2) learners only in phonology but not in morphosyntax. This study reexamines this claim by focusing on knowledge of clitic pronouns and word order in 24 L2 learners and 24 Spanish heritage speakers. Results of an oral production task, a written grammaticality judgment task, and a speeded comprehension task showed that, overall, heritage speakers seem to possess more nativelike knowledge of Spanish than their L2 counterparts. Implications for theories that stress the role of age and experience in L2 ultimate attainment and for the field of heritage language acquisition and teaching are discussed.
When speech is ambiguous, gesture steps in: Sensitivity to discourse-pragmatic principles in early childhood
Authors: SO WING CHEE , DEMIR ÖZLEM ECE , GOLDIN-MEADOW SUSAN
Published: December 2009

Young children produce gestures to disambiguate arguments. This study explores whether the gestures they produce are constrained by discourse-pragmatic principles: person and information status. We ask whether children use gesture more often to indicate the referents that have to be specified (i.e., third person and new referents) than the referents that do not have to be specified (i.e., first or second person and given referents). Chinese- and English-speaking children were videotaped while interacting spontaneously with adults, and their speech and gestures were coded for referential expressions. We found that both groups of children tended to use nouns when indicating third person and new referents but pronouns or null arguments when indicating first or second person and given referents. They also produced gestures more often when indicating third person and new referents, particularly when those referents were ambiguously conveyed by less explicit referring expressions (pronouns, null arguments). Thus Chinese- and English-speaking children show sensitivity to discourse-pragmatic principles not only in speech but also in gesture.
Conscience-Based Exemptions for Medical Students
Authors: WICCLAIR MARK R.
Published: December 2009

Just as physicians can object to providing services due to their ethical and/or religious beliefs, medical students can have conscience-based objections to participating in educational activities. In 1996, the Medical Student Section of the American Medical Association (AMA) introduced a resolution calling on the AMA to adopt a policy in support of exemptions for students with ethical or religious objections. In that report, students identified abortion, sterilization, and procedures performed on animals as examples of activities that might prompt requests for conscience-based exemptions (CBEs). In response to the student initiative, the Council on Medical Education recommended the adoption of seven “principles to guide exemption of medical students from activities based on conscience.” The House of Delegates adopted these principles in their entirety.
Actualizable Potential, Reproduction, and Embryo Research: Bringing Embryos into Existence for Different Purposes or Not at All
Authors: PERSSON INGMAR , SAVULESCU JULIAN
Published: December 2009

In several papers, John Harris has argued that if

i)

it is morally permissible to engage in reproduction, whether natural or artificial, despite knowledge that a large number of embryos will fail to implant and quickly die, then

ii)

it is morally permissible to produce embryos for other purposes that involve killing them, for instance, to harvest stem cells that may be used to save lives.
Hybrid discrete dynamically dimensioned search (HD‐DDS) algorithm for water distribution system design optimization
Authors: Tolson Bryan A. , Asadzadeh Masoud , Maier Holger R. , Zecchin Aaron
Published: December 2009

The dynamically dimensioned search (DDS) continuous global optimization algorithm by Tolson and Shoemaker (2007) is modified to solve discrete, single‐objective, constrained water distribution system (WDS) design problems. The new global optimization algorithm for WDS optimization is called hybrid discrete dynamically dimensioned search (HD‐DDS) and combines two local search heuristics with a discrete DDS search strategy adapted from the continuous DDS algorithm. The main advantage of the HD‐DDS algorithm compared with other heuristic global optimization algorithms, such as genetic and ant colony algorithms, is that its searching capability (i.e., the ability to find near globally optimal solutions) is as good, if not better, while being significantly more computationally efficient. The algorithm's computational efficiency is due to a number of factors, including the fact that it is not a population‐based algorithm and only requires computationally expensive hydraulic simulations to be conducted for a fraction of the solutions evaluated. This paper introduces and evaluates the algorithm by comparing its performance with that of three other algorithms (specific versions of the genetic algorithm, ant colony optimization, and particle swarm optimization) on four WDS case studies (21‐ to 454‐dimensional optimization problems) on which these algorithms have been found to perform well. The results obtained indicate that the HD‐DDS algorithm outperforms the state‐of‐the‐art existing algorithms in terms of searching ability and computational efficiency. In addition, the algorithm is easier to use, as it does not require any parameter tuning and automatically adjusts its search to find good solutions given the available computational budget.
Electrical transport and thermometry of electroformed titanium dioxide memristive switches
Authors: Borghetti Julien , Strukov Dmitri B. , Pickett Matthew D. , Yang J. Joshua , Stewart Duncan R. , Williams R. Stanley
Published: December 2009

We investigated the electrical transport of electroformed titanium dioxide memristive switches from liquid helium to room temperatures in order to better understand their internal states. After electroforming, we observed a continuous transition between two distinct limiting behaviors: a nearly Ohmic “ON”-state and an “OFF”-state characterized by conduction through a barrier. We interpret our data in terms of a model in which the electroforming step creates a conducting channel that does not completely bridge the metal contacts on the titanium dioxide film. The switching then occurs as a result of voltage-induced changes in the oxygen vacancy concentration in the gap between the tip of the channel and the adjacent metal contact. We used the metallic resistivity of the conduction channel as an in situ thermometer to measure the local device temperature, thus revealing an important implicit state variable.
Layer-by-layer growth and magnetic properties of Y3Fe5O12 thin films on Gd3Ga5O12
Authors: Krockenberger Y. , Yun K.-S. , Hatano T. , Arisawa S. , Kawasaki M. , Tokura Y.
Published: December 2009

We report on the layer-by-layer growth of epitaxial yttrium-iron-garnet (Y3Fe5O12) thin films on (111) and (110) Gd3Ga5O12 substrates as verified by the intensity oscillations of reflection high energy electron diffraction during pulsed laser deposition. X-ray diffraction indicates pseudomorphic lattice structure with slight expansion along out of plane from cubic one. The saturation magnetization well reproduces the full moment observed for bulk crystals. The crystallographic magnetic anisotropy was also preserved regardless of shape anisotropy in different orientations. Magnetic anisotropy similar to bulk crystals was observed for as-grown films which have not been subject to a postannealing process.
Solid-state dewetting of patterned thin films
Authors: Kim Donghyun , Giermann Amanda L. , Thompson Carl V.
Published: December 2009

Gold particle arrays have been produced through solid-state dewetting of patterned gold thin films. Patterns included rectangles and terminated lines of different widths, lengths, and film thickness. The particle spacing in long lines followed a Rayleigh-like dependence on the cross-sectional area of the line. Shorter lines had lower numbers of particles, indicating line-end effects. In some cases, ordered particle arrays were obtained. The probability of forming ordered particle arrays was shown to depend on the relative magnitudes of the length, width, and thickness of patterned structures. These trends are captured in design maps.
One-dimensional confinement of electric field and humidity dependent DNA conductivity
Authors: Leveritt John M. , Dibaya Carmen , Tesar Sarah , Shrestha Rajesh , Burin Alexander L.
Published: December 2009

The dependence of DNA assemblies conductance on relative humidity is investigated theoretically. Following earlier suggestions, we consider the ionic conductivity through the layers of water adsorbed by DNA molecules. The increase in humidity results in a growing water layer. The binding energy of ions depends on the thickness of the water layer due to change in water polarization. This dependence is very strong at smaller thicknesses of water layers due to the low-dimensional confinement of an electric field in water. We show that the associated change in ion concentration can explain the six orders of magnitude increase in conductivity, with relative humidity growing from 0.05 to 0.95.
Vortex domain wall chirality rectification due to the interaction with end domain spin structures in permalloy nanowires
Authors: Wilhelm E.-S. , McGrouther D. , Heyne L. , Bisig A. , Kläui M.
Published: December 2009

The interaction of vortex domain walls with the end domain spin structure present at the rectangular end of a ferromagnetic nanowire is investigated using Lorentz transmission electron microscopy. When vortex walls are moved with short field pulses towards the wire end an end vortex is formed, whose chirality is independent of the original vortex wall chirality but is determined by the spin configuration of the end domain. This acts as a domain wall chirality “rectifier,” which could be useful for applications based on domain walls. The observed chirality transformations are reproduced by micromagnetic simulations showing a complex reversal mechanism.
To grate a liquid into tiny droplets by its impact on a hydrophobic microgrid
Authors: Brunet P. , Lapierre F. , Zoueshtiagh F. , Thomy V. , Merlen A.
Published: December 2009

We report on experiments of drop impacting a hydrophobic microgrid of typical spacing a few tens of micrometers. Above a threshold in impact speed, liquid emerges to the other side, forming microdroplets of size about that of the grid holes. We propose a method to produce either a monodisperse spray or a single tiny droplet of volume as small as a few picolitres corresponding to a volume division of the liquid drop by a factor of up to 105. We also discuss the discrepancy of the measured thresholds with that predicted by a balance between inertia and capillarity.
Bioactive “self-sensing” optical systems
Authors: Domachuk Peter , Perry Hannah , Amsden Jason J. , Kaplan David L. , Omenetto Fiorenzo G.
Published: December 2009

Free-standing silk films are useful materials to manufacture nanopatterned optical elements and to immobilize bio-dopants such as enzymes while maintaining their biological activity. These traits were combined by incorporating hemoglobin into free-standing silk diffraction gratings to fabricate chemically responsive optofluidic devices responsive to ambient gas conditions, constituting a simple oxygen sensor. This type of self-analyzing optical system is enabled by the unique ability to reproduce high-fidelity optical structures in silk while maintaining the activity of entrapped proteins such as hemoglobin. These bioactive optical devices offer a direct readout capability, adding utility into the bioresponsive material arena.
Molecular polarizabilities in aqueous proton transfer reactions
Authors: Buin Andrei , Iftimie Radu
Published: December 2009

Dipole polarizabilities of individual ions and molecules are computed from first principles in three condensed-phase systems: pure water, pure hydrofluoric acid, and an equimolar mixture of water and hydrofluoric acid in which HF is mostly ionized. We find that the polarizability of fluorine and oxygen centers varies linearly with the value of the bond order, which measures the local degree of advancement of the ionization reaction F–H+H2O⇄[Fδ−⋅H⋅Oδ+H2]⇄F−+H3O+. This observation explains the validity of the Lorentz–Lorenz formula for mixtures of acids and water and could have important practical consequences concerning the construction of empirical polarizable reactive force fields. Our results are consistent with the Mulliken charge-transfer picture of proton transfer reactions. The present results also suggest that the average isotropic polarizability of a chemical entity changes substantially only when that entity is involved in charge-transfer processes.
p
-type conduction in beryllium-implanted hexagonal boron nitride films
Authors: He B. , Zhang W. J. , Yao Z. Q. , Chong Y. M. , Yang Y. , Ye Q. , Pan X. J. , Zapien J. A. , Bello I. , Lee S. T. , Gerhards I. , Zutz H. , Hofsäss H.
Published: December 2009

p -type conduction in hexagonal boron nitride (hBN) films was achieved by beryllium implantation and subsequent rapid thermal annealing treatment. The dependence of phase composition and electrical properties of hBN films on the implantation fluence and annealing was studied. A maximum resistivity reduction by six orders of magnitude was demonstrated. Hall measurements revealed a corresponding hole concentration of 3×1019 cm−3 and mobility of 27 cm2/V s. The activation energy of Be ions was estimated to be 0.21 eV. It is suggested that hBN is a promising wide bandgap semiconductor for applications in high-temperature electronic devices and transparent conductive coatings.
Bandgap engineering of graphene: A density functional theory study
Authors: Liu Lei , Shen Zexiang
Published: December 2009

Three ways of engineering the bandgap of graphene, i.e., surface bonding, isoelectronic codoping, and alternating electrical/chemical environment, are analyzed with the effective mass approximation and density-functional theory calculations. Surface bonding on graphene would lift its top σ valence bands above π valence states, open a sp3 gap, but also bury the linearly dispersive bands into the valence σ bands. Isoelectronic codoping and asymmetric electrical or chemical environment may open the π−π∗ gap of graphene by breaking its sublattice equivalence. The calculated effective mass versus bandgap may provide useful guidance for the future experimental efforts to fabricate graphene-based semiconductors.
Tuning micropillar cavity birefringence by laser induced surface defects
Authors: Bonato Cristian , Ding Dapeng , Gudat Jan , Thon Susanna , Kim Hyochul , Petroff Pierre M. , van Exter Martin P. , Bouwmeester Dirk
Published: December 2009

We demonstrate a technique to tune the optical properties of micropillar cavities by creating small defects on the sample surface near the cavity region with an intense focused laser beam. Such defects modify strain in the structure, changing the birefringence in a controllable way. We apply the technique to make the fundamental cavity mode polarization-degenerate and to fine tune the overall mode frequencies, as needed for applications in quantum information science.
VEGF-A expression by HSV-1–infected cells drives corneal lymphangiogenesis
Authors: Wuest Todd R. , Carr Daniel J.J.
Published: December 2009

Inflammatory lymphangiogenesis plays a crucial role in the development of inflammation and transplant rejection. The mechanisms of inflammatory lymphangiogenesis during bacterial infection, toll-like receptor ligand administration, and wound healing are well characterized and depend on ligands for the vascular endothelial grow factor receptor (VEGFR) 3 that are produced by infiltrating macrophages. But inflammatory lymphangiogenesis in nonlymphoid tissues during chronic viral infection is unstudied. Herpes simplex virus 1 (HSV-1) infection of the cornea is a leading cause of blindness and depends on aberrant host immune responses to antigen within the normally immunologically privileged cornea. We report that corneal HSV-1 infection drives lymphangiogenesis and that corneal lymphatics persist past the resolution of infection. The mechanism of HSV-1–induced lymphangiogenesis was distinct from the described mechanisms of inflammatory lymphangiogenesis. HSV-1–elicited lymphangiogenesis was strictly dependent on VEGF-A/VEGFR-2 signaling but not on VEGFR-3 ligands. Macrophages played no role in the induction of lymphangiogenesis and were not a detectable source of VEGF-A. Rather, using VEGF-A reporter transgenic mice, we have identified infected epithelial cells as the primary source of VEGF-A during HSV-1 infection. Our results indicate that HSV-1 directly induces vascularization of the cornea through up-regulation of VEGF-A expression.
First Report of Soilborne wheat mosaic virus on Triticum aestivum in Washington State
Authors: Murray T. D. , Pappu H. R. , Smiley R. W.
Published: December 2009

SBWMV was recently also reported from an adjacent county in Oregon. Confirmation of SBWMV in Washington highlights the need for increased awareness of the disease and implementing measures to contain its further spread in the region.

Accepted for publication 18 September 2009. Published 4 December 2009.
Exserohilum Leaf Spot on Tiger Grass
Authors: Brunings Asha M. , Datnoff Lawrence E. , Palmateer Aaron J. , Locke James C. , Krause Charles R.
Published: December 2009

Tiger grass [Thysanolaena maxima (Roxb.) Kuntze] is a popular ornamental grass grown throughout landscapes in South Florida. In the summer of 2006, a leaf spot was observed on tiger grass in the landscape and a commercial nursery in Homestead, FL. The causal agent of the leaf spot was isolated and characterized morphologically and molecularly as Exserohilum rostratum (Drechsler) Leonard & Suggs. At high inoculum densities, symptoms were apparent as early as 12 h after inoculation, and caused widespread necrosis. Germinating conidia of E. rostratum and appressoria were observed in direct association with lesions. This newly discovered disease could potentially have a dramatic effect on the aesthetic quality and salability of this landscape ornamental.

Accepted for publication 24 September 2009. Published 15 December 2009.
Nitrogen deposition in tropical forests from savanna and deforestation fires
Authors: CHEN YANG , RANDERSON JAMES T. , VAN DER WERF GUIDO R. , MORTON DOUGLAS C. , MU MINGQUAN , KASIBHATLA PRASAD S.
Published: December 2009

We used satellite‐derived estimates of global fire emissions and a chemical transport model to estimate atmospheric nitrogen (N) fluxes from savanna and deforestation fires in tropical ecosystems. N emissions and reactive N deposition led to a net transport of N equatorward, from savannas and areas undergoing deforestation to tropical forests. Deposition of fire‐emitted N in savannas was only 26% of emissions – indicating a net export from this biome. On average, net N loss from fires (the sum of emissions and deposition) was equivalent to approximately 22% of biological N fixation (BNF) in savannas (4.0 kg N ha−1 yr−1) and 38% of BNF in ecosystems at the deforestation frontier (9.3 kg N ha−1 yr−1). Net N gains from fires occurred in interior tropical forests at a rate equivalent to 3% of their BNF (0.8 kg N ha−1 yr−1). This percentage was highest for African tropical forests in the Congo Basin (15%; 3.4 kg N ha−1 yr−1) owing to equatorward transport from frequently burning savannas north and south of the basin. These results provide evidence for cross‐biome atmospheric fluxes of N that may help to sustain productivity in some tropical forest ecosystems on millennial timescales. Anthropogenic fires associated with slash and burn agriculture and deforestation in the southern part of the Amazon Basin and across Southeast Asia have substantially increased N deposition in these regions in recent decades and may contribute to increased rates of carbon accumulation in secondary forests and other N‐limited ecosystems.
Effects of a half a millennium winter on a deep lake – a shape of things to come?
Authors: STRAILE DIETMAR , KERIMOGLU ONUR , PEETERS FRANK , JOCHIMSEN MARC C. , KÜMMERLIN REINER , RINKE KARSTEN , ROTHHAUPT KARL‐OTTO
Published: December 2009

Analyses of the effects of extreme climate periods have been used as a tool to predict ecosystem functioning and processes in a warmer world. The winter half‐year 2006/2007 (w06/07) has been extremely warm and was estimated to be a half‐a‐millennium event in central Europe. Here we analyse the consequences of w06/07 for the temperatures, mixing dynamics, phenologies and population developments of algae and daphnids (thereafter w06/07 limnology) in a deep central European lake and investigate to what extent analysis of w06/07 limnology can really be used as a predictive tool regarding future warming. Different approaches were used to put the observations during w06/07 into context: (1) a comparison of w06/07 limnology with long‐term data, (2) a comparison of w06/07 limnology with that of the preceding year, and (3) modelling of temperature and mixing dynamics using numerical experiments. These analyses revealed that w06/07 limnology in Lake Constance was indeed very special as the lake did not mix below 60 m depth throughout winter. Because of this, anomalies of variables associated strongly with mixing behaviour, e.g., Schmidt stability and a measure for phosphorus upward mixing during winter exceeded several standard deviations the long‐term mean of these variables. However, our modelling results suggest that this extreme hydrodynamical behaviour was only partially due to w06/07 meteorology per se, but depended also strongly on the large difference in air temperature to the previous cold winter which resulted in complete mixing and considerable cooling of the water column. Furthermore, modelling results demonstrated that with respect to absolute water temperatures, the model ‘w06/07’ most likely underestimates the increase in water temperature in a warmer world as one warm winter is not sufficient to rise water temperatures in a deep lake up to those expected under a future climate.
Expression profiles of proliferative and antiapoptotic genes in sporadic and colitis‐related mouse colon cancer models
Authors: Švec Jiří , Ergang Peter , Mandys Václav , Kment Milan , Pácha Jiří
Published: December 2009

Elevated levels of survivin, telomerase catalytic subunit (TERT), integrin‐linked kinase (ILK), cyclooxygenase 2 (COX‐2), inducible nitric oxide synthase (iNOS) and the regulatory factors c‐MYB and Tcf‐4 are often found in human cancers including colorectal cancer (CRC) and have been implicated in the development and progression of tumorigenesis. The aim of this study was to determine the expression of these genes in mouse models of sporadic and colitis‐associated CRC. To address these issues, we used qRT‐PCR approach to determine changes in gene expression patterns of neoplastic cells (high‐grade dysplasia/intramucosal carcinoma) and surrounding normal epithelial cells in A/J and ICR mouse strains using laser microdissection. Both strains were injected with azoxymethane and ICR mice were also given drinking water that contained 2% dextran sodium sulphate. In both sporadic (A/J mice) and colitis‐associated (ICR mice) models of CRC, the levels of TERT mRNA, COX‐2 mRNA and Tcf‐4 mRNA were higher in neoplastic cells than in surrounding normal epithelial cells. In contrast, survivin mRNA was upregulated only in neoplastic cells from A/J mice and ILK mRNA was upregulated only in neoplastic cells from ICR mice. However, the expression of iNOS mRNA was similar in normal and neoplastic cells in both models and c‐MYB mRNA was actually downregulated in neoplastic cells compared with normal cells in both models. These findings suggest that the genetic background and/or the molecular mechanisms of tumorigenesis associated with genotoxic insults and colonic inflammation influence the gene expression of mTERT, COX‐2, Tcf‐4, c‐MYB, ILK and survivin in colon epithelial neoplasia.
Little evidence for limiting similarity in a long‐term study of a roadside plant community
Authors: Thompson Ken , Petchey Owen L. , Askew Andrew P. , Dunnett Nigel P. , Beckerman Andrew P. , Willis Arthur J.
Published: December 2009

1. Understanding the assembly of ecological communities is central to managing such communities for conservation, restoration and invasion resistance. A central plank of modern theory is limiting similarity, i.e. a finite limit to the similarity of coexisting species.

2. Here, we test the theory of limiting similarity in a roadside plant community that has been monitored for almost 50 years. We measure differences between observed trait distributions (‘functional diversity, FD’) and those expected on the basis of three different null models, several trait combinations and four different methods of measuring FD.

3. The general pattern was of lower observed than expected FD, or no difference between observed and expected FD, independent of FD measure and trait set. Some rare species had ‘unusual’ traits; thus if the null model assumed all species had equal chance of occurring, observed FD was generally lower than expected by chance, but if the null model assumed the probability of occurrence of rare species was proportional to the observed frequency of occurrence or excluded rare species, observed FD was not significantly different from expected.

4. Synthesis. The results do not support the idea that niche differences are central to the assembly of this plant community. However, they do suggest that rare species may be functionally unusual, and that the patterns revealed by this kind of analysis can be strongly influenced by the choice of null model, and much less so by the choice of FD measure.
Pigs transgenic for human thrombomodulin have elevated production of activated protein C
Authors: Petersen Björn , Ramackers Wolf , Tiede Andreas , Lucas‐Hahn Andrea , Herrmann Doris , Barg‐Kues Brigitte , Schuettler Wolfgang , Friedrich Lars , Schwinzer Reinhard , Winkler Michael , Niemann Heiner
Published: December 2009

Petersen B, Ramackers W, Tiede A, Lucas‐Hahn A, Herrmann D, Barg‐Kues B, Schuettler W, Friedrich L, Schwinzer R, Winkler M, Niemann H. Pigs transgenic for human thrombomodulin have elevated production of activated protein C. Xenotransplantation 2009; 16: 486–495. © 2009 John Wiley & Sons A/S.

Abstract: Background: The inability of porcine thrombomodulin (TM) to activate human anticoagulant protein C after pig‐to‐human xenotransplantation may lead to an aberrant activation of coagulation with microthrombosis and ultimately failure of the transplanted organ. Here, we describe the production of triple‐transgenic pigs expressing hCD59/DAF and human thrombomodulin (hTM) and tested hTM‐transgenic fibroblasts obtained from these pigs for their ability to activate human protein C in a new in vitro assay.

Methods: Fibroblast cell cultures were established from a hCD59/DAF transgenic pig and transfected with a vector coding for hTM under transcriptional control of the CMV promoter. Transfected cells were analyzed for integration and expression of the hTM vector by PCR and RT‐PCR. One cell clone was used as donor for somatic cell nuclear transfer to produce triple transgenic (CD59/DAF/hTM) pigs. Pigs were characterized in detail with regard to hTM integration and expression by PCR, RT‐PCR, Northern blot, Western blot, immunostaining, and FACS analysis. Fibroblasts from hTM‐transgenic pigs were analyzed in a new in vitro hTM coactivity assay to assess the production of activated protein C (aPC) and results were compared to those from wild‐type controls.

Results: In total, 1040 cloned transgenic embryos were transferred to eight recipients. Five recipients remained pregnant and delivered 22 piglets. Expression of hTM was detected in all xenorelavant organs including heart, liver, kidney, lung, and pancreas. The lowest levels of expression were found in lung and liver while all animals showed a strong, but frequently patchy expression pattern of hTM in heart, kidney, and pancreas. The hTM cofactor activity (ranging on a scale from 5–18 U/105 cells/2h) was significantly higher in fibroblasts of hTM‐transgenic clones compared to wild‐type porcine fibroblasts (1.7 U/105cells/2h).

Conclusions: For the first time, healthy hTM‐transgenic pigs could be successfully generated by somatic cell nuclear transfer. hTM can be expressed in porcine organs without perturbation of the porcine coagulation system. hTM‐transgenic porcine fibroblasts showed elevated aPC production in an in vitro hTM coactivity assay. These findings warrant further work on the control of the xenogenic activation of coagulation by transgenic approaches.
Successful cross‐breeding of cloned pigs expressing endo‐β‐galactosidase C and human decay accelerating factor
Authors: Yazaki Satoko , Iwamoto Masaki , Onishi Akira , Miwa Yuko , Suzuki Shunichi , Fuchimoto Dai‐ichiro , Sembon Shoichiro , Furusawa Tadashi , Hashimoto Michiko , Oishi Takatsugu , Liu DaGe , Nagasaka Takaharu , Kuzuya Takafumi , Maruyama Shoichi , Ogawa Haruko , Kadomatsu Kenji , Uchida Kazuharu , Nakao Akimasa , Kobayashi Takaaki
Published: December 2009

Yazaki S, Iwamoto M, Onishi A, Miwa Y, Suzuki S, Fuchimoto D, Sembon S, Furusawa T, Hashimoto M, Oishi T, Liu D, Nagasaka T, Kuzuya T, Maruyama S, Ogawa H, Kadomatsu K, Uchida K,  Nakao A, Kobayashi T. Successful cross‐breeding of cloned pigs expressing endo‐β‐galactosidase C and human decay accelerating factor. Xenotransplantation 2009; 16: 511–521. © 2009 John Wiley & Sons A/S.

Abstract: Background:  For successful organ xenotransplantation, genetically engineered pigs have been actively produced. Our attention has focused on (i) reduction of αGal expression by its digestion enzyme, endo‐β‐galactosidase C (EndoGalC), and (ii) inhibition of complement activation by human decay accelerating factor (hDAF). Cell sorting and nuclear transfer enabled the effective production of cloned pigs expressing transgene at high levels. We report the successful cross‐breeding of pigs expressing EndoGalC and hDAF.

Methods:  After hDAF and EndoGalC genes were transfected into pig fibroblasts from the fetus of Landrace × Yorkshire and Meishan, respectively, transfected cells expressing transgenes effectively were collected using a cell sorter. Cloned pigs were produced using the technology of somatic cell nuclear transfer. After cross‐breeding of cloned pigs, kidneys expressing both EndoGalC and hDAF were transplanted into baboons to examine the efficacy of gene transduction.

Results:  Well‐designed cloned pigs were produced by cross‐breeding. αGal expression levels in cloned pigs were reduced up to 2 to 14%, compared to that in wild‐type pigs. hDAF expression reached about 10‐ to 70‐fold, compared to that in human umbilical vein endothelial cells. No congenital deformity was observed. There was no problem of increased stillbirth rate or growth retardation. Hyperacute rejection could be avoided in such a cloned pig to baboon kidney transplantation without any treatment for anti‐pig antibody removal. However, grafts suffered from fibrin deposition as early as 1 h after transplantation, and were rejected after 1 week.

Conclusions:  Using a cell sorting system for effective collection of transfected cells, two types of cloned pigs were produced with a very high level of hDAF expression and a low level of αGal expression. Such genetic modification was effective in preventing hyperacute rejection, but there was an immediate lapse into procoagulation after transplantation, resulting in acute vascular rejection. Effective suppression of antibody binding to the graft would be necessary, even if a high level of hDAF is expressed.
Short‐term complications of wide‐lumen stapled anastomosis after ileocolic resection for Crohn’s disease: who is at risk?
Authors: Riss S. , Bittermann C. , Zandl S. , Kristo I. , Stift A. , Papay P. , Vogelsang H. , Mittlböck M. , Herbst F.
Published: December 2009

Aim  There is growing evidence that stapled anastomoses are similarly effective compared to hand‐sewn anastomoses in Crohn’s patients. This study was designed to assess safety and limitations of wide‐lumen stapled ileocolic anastomoses.

Method  All patients with ileocolic resections for Crohn’s disease perfomed between 1998 and 2006 were studied. A stapled anastomosis was constructed whenever possible. Potential risk factors for postoperative complications were recorded, retrospectively. Univariate and multivariate analyses were performed.

Results  In 209 out of 220 cases (95%, 132 primary operations) stapled anastomoses were performed. Eleven patients underwent a hand‐sewn anastomosis owing to massive bowel dilatation (n = 7) or increased wall thickness (n = 4). There were 10 major (4.5%; surgical: 8, medical: 2) complications including two anastomotic leaks and one anastomotic bleed (all from stapled anastomoses) and one death not related to the anastomosis. Minor complications occurred in 25 patients.

In multivariate analysis, major surgical postoperative complications were significantly associated with a low level of albumin (P = 0.0113) and previous resections for Crohn’s disease (P = 0.0144).

Conclusion  Stapled ileocolic anastomosis was safe in the majority of Crohn’s patients. The most important limitation was technical impracticability. A low level of albumin and a history of previous resection increased the risk of postoperative complications.
Autofluorescence imaging colonoscopy for the detection of dysplastic lesions in ulcerative colitis: a pilot study
Authors: Matsumoto T. , Nakamura S. , Moriyama T. , Hirahashi M. , Iida M.
Published: December 2009

Aim  Autofluorescence imaging (AFI) is a novel technology for endoscopy, which enhances neoplastic lesions of the gastrointestinal tract. The aim of this investigation was to examine whether AFI colonoscopy can identify dysplasia in ulcerative colitis.

Method  We examined 48 patients with ulcerative colitis by AFI colonoscopy. Apparently flat, coarse granular mucosa and visible protruding lesions under conventional colonoscopy were observed by AFI. Those target areas were classified into low AF and high AF according to the colour under AFI colonoscopy. The grade of dysplasia was determined in the specimens obtained from the target areas.

Results  About 126 sites (35 protruding lesions and 91 flat areas) were examined by AFI colonoscopy. AF was determined to be high in 42 areas and to be low in 84 areas. The positive rate of dysplasia was higher in protrusions (31%) than in flat mucosa (3.3%, P < 0.0001). The rate of positive dysplasia was not statistically different between lesions determined to be low AF (14%) and those to be high AF (5%, P = 0.09). The positive rate of dysplasia in protruding lesions was significantly higher in low AF than in high AF (45.0%vs 13.3%, P = 0.043), while the value in flat lesions was not different between low AF and high AF (8.2%vs 0%, P = 0.3).

Conclusions  Autofluorescence imaging colonoscopy seems to have a role for the detection of dysplaia in ulcerative colitis.
HUMANITY AS AN OBJECT OF RESPECT: IMMANUEL KANT'S ANTHROPOLOGICAL APPROACH AND THE FOUNDATION FOR MORALITY
Authors: ROLF SIBYLLE
Published: December 2009

The article deals with Kant's understanding of personhood and autonomy. It highlights the connection of autonomy and human dignity within Kant's appreciation of morality, and indicates how his distinction between the empirical and transcendental spheres enables Kant to extend dignity even to humans who are not actually autonomous. Turning to contemporary approaches within ethics that refer to Kant but omit this transcendental framework, it defends the necessity of a trans‐empirical frame within the Kantian system and hints at consequences for bioethics. It concludes that Kant works with neither an absolutist notion of freedom in terms of solipsistic autarky, nor an empirical freedom and autonomy that begin and end at certain points of time.
How adults with learning disabilities view living independently
Authors: Bond Rebecca J. , Hurst Jenni
Published: December 2009

Accessible summary

Nine people with learning disabilities talked about living on their own.

They talked about good and bad things in their lives.

They said it is sometimes hard but better than living in residential care.

They want people who provide services to know that it can be hard to live alone.

It is seen as increasingly important for people with learning disabilities to be supported to live independently and manage their own self care, productivity and leisure activities. This qualitative study explored the experiences of nine adults with mild learning disabilities who lived alone with minimal support. Their narratives were analysed using thematic analysis and seven themes emerged. These were feelings on living alone, practical issues, support issues, choice and control, vulnerability, health issues and the impact of having a learning disability. This study has implications for service users, professionals and service providers working with people with learning disabilities. In particular, the issues raised reflected the need to increase social inclusion and provide the right level of support. Participants talked about service providers needing to be aware of their vulnerability and wanted people to respect their right to make their own choices.
Partitioning diversity for conservation analyses
Authors: Jost Lou , DeVries Philip , Walla Thomas , Greeney Harold , Chao Anne , Ricotta Carlo
Published: December 2009

Aim  Differentiation of sites or communities is often measured by partitioning regional or gamma diversity into additive or multiplicative alpha and beta components. The beta component and the ratio of within‐group to total diversity (alpha/gamma) are then used to infer the compositional differentiation or similarity of the sites. There is debate about the appropriate measures and partitioning formulas for this purpose. We test the main partitioning methods, using empirical and simulated data, to see if some of these methods lead to false conclusions, and we show how to resolve the problems that we uncover.

Location  South America, Ecuador, Orellana province, Rio Shiripuno.

Methods  We construct sets of real and simulated tropical butterfly communities that can be unambiguously ranked according to their degree of differentiation. We then test whether beta and similarity measures from the different partitioning approaches rank these datasets correctly.

Results  The ratio of within‐group diversity to total diversity does not reflect compositional similarity, when the Gini–Simpson index or Shannon entropy are used to measure diversity. Additive beta diversity based on the Gini–Simpson index does not reflect the degree of differentiation between N sites or communities.

Main conclusions  The ratio of within‐group to total diversity (alpha/gamma) should not be used to measure the compositional similarity of groups, if diversity is equated with Shannon entropy or the Gini–Simpson index. Conversion of these measures to effective number of species solves these problems. Additive Gini–Simpson beta diversity does not directly reflect the differentiation of N samples or communities. However, when properly transformed onto the unit interval so as to remove the dependence on alpha and N, additive and multiplicative beta measures yield identical normalized measures of relative similarity and differentiation.
Is detrusor hypertrophy in women associated with voiding dysfunction?
Authors: LEKSKULCHAI Orawan , DIETZ Hans Peter
Published: December 2009

Background:  In men, bladder wall thickness ≥5 mm seems to be a useful predictor of outlet obstruction, with a diagnostic value exceeding that of free uroflowmetry indices. There are no data in the literature examining whether this may also apply in women.

Aims:  To identify the relationships between detrusor wall thickness (DWT) and symptoms and urodynamic findings suggestive of voiding dysfunction.

Methods:  This is a retrospective study analysing data sets of 686 women seen for urodynamic testing in a tertiary urogynaecological unit. Hesitancy, poor stream and stop–start voiding were recorded as symptoms of voiding dysfunction. All women underwent free uroflowmetry and multichannel urodynamic testing. We used the urethral resistance factor (URA) and the obstruction coefficient (OCO), methods employed to quantify bladder outlet resistance in men. Transperineal ultrasound for DWT was performed after voiding and catheter removal. Statistical analysis was carried out by using the statistical software (spss 15.0; SPSS Inc., Chicago, IL, USA).

Results:  Symptoms of voiding dysfunction were reported by 33.1% of patients and 22.4% had urodynamically diagnosed voiding dysfunction. The mean DWT in symptomatic women was not statistically different from the mean DWT in those without symptoms. URA and OCO of symptomatic women were significantly different from those of asymptomatic women (P < 0.01). DWT was not associated with parameters of voiding function, URA or OCO.

Conclusions:  Contrary to the situation in men, increased DWT in women does not seem to be associated with symptoms or signs of voiding dysfunction. Therefore, DWT cannot be used as a predictor of voiding difficulty in women.
Intraperitoneal chemotherapy for advanced epithelial ovarian malignancy: Lessons learned
Authors: BUNTING Michael , CHAN Warren , BRAND Alison , BLOMFIELD Penelope
Published: December 2009

Background:  The administration of intraperitoneal (IP) chemotherapy as first‐line adjuvant treatment for women with optimally debulked advanced ovarian malignancy results in improved median and overall survival when compared with intravenous (IV) chemotherapy. However, the number of adverse events and toxicities are increased in patients treated with IP chemotherapy. In addition, the administration of IP chemotherapy is technically more challenging and the schedule is more demanding in terms of time and resources.

Aims:  We report on our initial experience with the administration of IP chemotherapy at two gynaecological oncology units in Australia.

Methods:  We collected retrospective data from a series of 23 women undergoing IP chemotherapy as adjuvant treatment for advanced ovarian cancer. In addition to standard (Common Terminology Criteria for Adverse Events v3.0, CTCAE) toxicity data, we collected technical data specific to the administration of IP chemotherapy.

Results:  The average number of IP chemotherapy cycles received was 4.3. Forty‐three per cent of patients received all six planned IP chemotherapy cycles. Thirty‐nine per cent of patients discontinued their IP treatment. Of those, 22% were discontinued because of drug‐related toxicities and the remaining 17% experienced a port complication or toxicity directly related to the route of administration.

Conclusions:  This study demonstrates the feasibility and practicality of and lessons learned from initial experiences with IP chemotherapy for ovarian cancer in Australia.