bluuebunny/crossref_metadata_2025 huggingface dataset:
Parent firm effects on founder turnover: parent success, founder legitimacy, and founder tenure
Authors: Boeker Warren , Fleming Brandon
Published: September 2010

Empirical studies examining new ventures have demonstrated a significant degree of founder turnover after start‐up as founders are replaced by ‘professional’ managers. We examine how founders' past experience in their prior employer (their parent firm) affects their tenure in the new venture. Founders coming from more successful parent firms, with more prior affiliations among the venture's cofounders and with prior start‐up experience are more likely to remain with the new venture after founding. These effects are more pronounced in cases where the technologies employed by the start‐up are more uncertain. Copyright © 2010 Strategic Management Society.
Study on the biological effect of Tourmaline on the cell membrane of E. coli
Authors: Qiu Shan , Ma Fang , Wo Yuan , Xu Shanwen
Published: September 2010

The biological effect of tourmaline on the cell membrane of E. coli by microcalorimetry, fluorescence polarization, ion analysis and fourier transform infrared was studied. It was observed that tourmaline of low concentration can promote growth of the bacteria, while tourmaline of high concentration has inhibitory effects on E. coli. Fluorescence polarization has shown a significant decrease in membrane fluidity and the increase of permeability of cell membrane. The ion analysis result suggested that the absorbability of nutrition from the medium becomes easier. Thus, E. coli grew faster in the presence of tourmaline than the native. With high concentration of tourmaline, however, the growth of E. coli was inhibited because the selective barrier of cell membrane for the bacteria was seriously damaged. Besides, changes of the spectral profile of E. coli were observed, which has shown the damages of surface groups on the cell membrane, which is the molecular basis for the biological effect of tourmaline. Copyright © 2010 John Wiley & Sons, Ltd.
Form und Tragverhalten hyperbolischer Gittertürme
Authors: Beckh Matthias , Hoheisel Meike
Published: September 2010

Mit dem im Jahr 1989 von Rainer Graefe, Murat Gappoev und Ottmar Pertschi herausgegebenen Buch “Die Kunst der sparsamen Konstruktion” ist das Werk des russischen Leichtbaupioniers Vladimir G. Šuchov in das Bewusstsein des deutschsprachigen Fachpublikums getreten. Seit 2007 werden am Lehrstuhl für Tragwerksplanung der Technischen Universität München (Prof. Dr.‐Ing. Rainer Barthel) die hyperbolischen Turmstrukturen von Vladimir G. Šuchov untersucht. Neben der Dokumentation der bestehenden Türme und der Analyse der originalen Planunterlagen und Berechnungen bilden die Untersuchungen zum Tragverhalten der Türme einen wichtigen Bestandteil der Arbeit. Im folgenden Beitrag soll die Tragwirkung von einstöckigen hyperbolischen Gittertürmen sowie die Wechselwirkungen zwischen Form und Tragverhalten aufgezeigt werden.

Interaction of form and structural behaviour of hyperboloid lattice towers. The renown Russian engineer Vladimir Shukhov invented and patented in 1896 the hyperboloid lattice tower. In the following four decades he built about 200 towers with his new system. Most of them served as water towers, others were built as lighthouses or radio stations. Form and structure of these towers varies depending on their location and purpose. The geometry of hyperboloid lattice towers is based on five key parameters. The authors undertook an extensive parameter study to explore the interdependencies between the key parameters and their effect on the ultimate bearing load of the structure. Apart from the lattice configuration that was employed by Shukhov, two alternative options are discussed.
Friction connection in tubular towers for a wind turbine
Authors: Veljkovic Milan , Feldmann Markus , Naumes Johannes , Pak Daniel , Rebelo Carlos , Simões da Silva Luís
Published: September 2010

Innovative solution for assembling joints of a tubular tower for wind turbines has been studied by a European consortium since 2005 and the HISTWIN (High‐Strength Steel Tower for Wind Turbine) project provides background for design of the friction connection considered. This solution is simpler to produce and 80% less expensive than traditional flange connection. A feasibility study at the production plant indicates that the towers would be easy to assemble in‐situ. In addition to the direct costs savings due to technical simplicity of the solution, the higher fatigue endurance than the flange connection is experimentally established. The loss of pretension forces in the friction connection with long opened slotted holes is studied using segment shortterm and long‐term static tests, fatigue tests, down‐scaled bending tests and by a specimen used in a feasibility study. The total reduction of the costs for tower is estimated to about 10% to 15% compared to the traditional tower with the flange connection.

Reibverbindung für Türme von Windenergieanlagen. Im Rahmen des europäischen RFCS (Research Fund for Coal and Steel) Projektes HISTWIN wird seit 2005 eine innovative Reibverbindung für Verbindungsstöße von Windenergieanlagen entwickelt und untersucht. Im Vergleich zur konventionellen Flanschverbindung ist die untersuchte Lösung sowohl einfacher als auch kostengünstiger herzustellen, wobei mit Einsparungen von bis zu 80% für die Verbindung gerechnet wird. Der problemlose Zusammenbau vor Ort wurde durch eine im Werk durchgeführte Machbarkeitsstudie überprüft. Weiterhin wurden experimentelle Untersuchungen zur im Vergleich zu konventionellen Flanschverbindungen höheren Ermüdungsbeanspruchbarkeit der Verbindungsmittel durchgeführt. Der Vorspannkraftverlust in der Langlochverbindung wurde auf Basis von statischen Kurzzeit‐ und Langzeitversuchen, Ermüdungsversuchen sowie skalierten 4‐Punkt Biegeversuchen untersucht. Die sich aus der neuen Verbindung ergebenden Kosteneinsparungen belaufen sich auf ca. 10 bis 15%.
Three Novel 1‐H‐Benzimidazole‐5‐Carboxylate‐Based Nickel(II)/Cobalt(II) Coordination Polymers: Synthesis, Crystal Structures, Luminescent, and Magnetic Properties
Authors: Zhao Li‐Na , Liu Tian‐Yu , Liu Zhong‐Yi , Yang En‐Cui , Zhao Xiao‐Jun
Published: September 2010

Three 1H‐benzimidazole‐5‐carboxylate (Hbic–)‐based coordination polymers, {[Ni(H2O)(Hbic)2]·2H2O}n (1), {[Ni(H2O)2(Hbic)2]·3H2O}n (2), and {[Co2(H2O)4(Hbic)4]·4DMF·3H2O}n (3) were obtained by reactions of the ligand H2bic and NiII or CoII salts in the presence of different structure directing molecules. They were structurally characterized by single‐crystal X‐ray diffraction, IR spectra, elemental analysis, thermal stability, luminescent, and magnetic measurements. Structural analysis suggests that the three polymers exhibit a 2D (4, 4) layer for 1 and 1D linear double chains for both 2 and 3 due to the variable binding modes and the specific spatial orientation of the Hbic– ligand towards the different paramagnetic metal ions, which were further aggregated into different 3D supramolecular architectures by popular hydrogen‐bonding interactions. Weak and comparable antiferromagnetic couplings mediating by Hbic– bridge are observed between the neighboring spin carriers for 2 and 3, respectively. Additionally, complexes 1–3 also display different luminescence emissions at room temperature due to the ligand‐to‐metal charge transfer.
Presence and Persistence of Nutrition‐Related Symptoms During the First Year Following Esophagectomy with Gastric Tube Reconstruction in Clinically Disease‐Free Patients
Authors: Haverkort E. B. , Binnekade J. M. , Busch O. R. C. , van Berge Henegouwen M. I. , de Haan R. J. , Gouma D. J.
Published: September 2010

Background

Esophagectomy with gastric tube reconstruction results in a variety of postoperative nutrition‐related symptoms that may influence the patient’s nutritional status.

Methods

We developed a 15‐item questionnaire, focusing on the nutrition‐related complaints the first year after an esophagectomy. The questionnaire was filled out the first week after discharge and 3, 6, and 12 months after surgery. The use of enteral nutrition, meal size and frequency, social aspects related to eating, defecation pattern, and body weight were recorded at the same time points. We analyzed the relationship between the baseline characteristics and the number of nutrition‐related symptoms, as well as the relationship between those symptoms and body weight with linear mixed models.

Results

We found no significant within‐patient change for the total number of nutrition‐related symptoms (P = 0.67). None of the baseline factors were identified as predictors of the complaint scores. The most frequently experienced complaints were early satiety, postprandial dumping syndrome, inhibited passage due to high viscosity, reflux, and absence of hunger. One year after surgery, meal sizes were still smaller, the social aspects of eating were influenced negatively, and patients experienced an altered stool frequency. Directly after the surgical procedure 78% of the patients lost weight, and the entire postoperative year the mean body weight remained lower (P = 0.47). We observed no association between the complaint scores and body weight (P = 0.15).

Conclusions

After an esophagectomy, most patients struggle with nutrition‐related symptoms, are confronted with nutrition‐related adjustments and a reduced body weight.
ON THE EXISTENCE OF NOWHERE-ZERO VECTORS FOR LINEAR TRANSFORMATIONS
Authors: AKBARI S. , HASSANI MONFARED K. , JAMAALI M. , KHANMOHAMMADI E. , KIANI D.
Published: September 2010

A matrix A over a field F is said to be an AJT matrix if there exists a vector x over F such that both x and Ax have no zero component. The Alon–Jaeger–Tarsi (AJT) conjecture states that if F is a finite field, with |F|≥4, and A is an element of GL n (F) , then A is an AJT matrix. In this paper we prove that every nonzero matrix over a field F, with |F|≥3 , is similar to an AJT matrix. Let AJTn (q) denote the set of n×n, invertible, AJT matrices over a field with q elements. It is shown that the following are equivalent for q≥3 : (i) AJTn (q)=GL n (q) ; (ii) every 2n×n matrix of the form (A∣B)t has a nowhere-zero vector in its image, where A,B are n×n, invertible, upper and lower triangular matrices, respectively; and (iii) AJTn (q) forms a semigroup.
Adrenocorticotrophic hormone-stimulated cortisol release by the head kidney inter-renal tissue from sea bream (Sparus aurata) fed with linseed oil and soyabean oil
Authors: Ganga Rachid , Bell J. G. , Montero D. , Atalah E. , Vraskou Y. , Tort L. , Fernandez A. , Izquierdo M. S.
Published: September 2010

The mode of action of highly unsaturated fatty acids (HUFA) in regulating gilthead sea bream (Sparus aurata) head kidney (HK) cortisol production was studied throughin vitrotrials using a dynamic superfusion system. Fish were previously fed with different diets containing several inclusion levels of linseed oil (LO) or soyabean oil (SO) for 26 weeks. Five diets were tested; anchovy oil was the only lipid source for the control diet (fish oil, FO) and two different substitution levels (70 and 100 %) were tested using either LO or SO (70LO, 70SO, 100LO and 100SO). Fatty acid compositions of the HK reflected the dietary input, thus EPA, DHA, arachidonic acid andn-3 HUFA were significantly (P < 0·05) reduced in fish fed vegetable oils compared with fish fed the FO diet. Feeding 70 or 100 % LO increased significantly (P < 0·05) cortisol release in HK after stimulation with adrenocorticotrophic hormone (ACTH), while feeding SO had no effect on this response. Cortisol stimulation factor (SF) was increased in fish fed the 70LO and 100LO diets compared with fish fed the control diet. Moreover, eicosanoid inhibition by incubating the HK tissue with indomethacin (INDO) as a cyclo-oxygenase (COX) inhibitor, or nordihydroguaiaretic acid (NDGA) as a lipoxygenase (LOX) inhibitor, significantly reduced (P < 0·05) the cortisol release after ACTH stimulation in the 70LO and 100LO diets. Cortisol SF was reduced in the FO, 70LO and 100LO diets when incubating the HK with INDO or NDGA, while it was increased in the 70SO diet. The present results indicate that changing the fatty acid profile of gilthead sea bream HK by including LO and/or SO in the fish diet affected thein vitrocortisol release, and this effect is partly mediated by COX and/or LOX metabolites.
The association of personality disorders with the prospective 7-year course of anxiety disorders
Authors: Ansell E. B. , Pinto A. , Edelen M. O. , Markowitz J. C. , Sanislow C. A. , Yen S. , Zanarini M. , Skodol A. E. , Shea M. T. , Morey L. C. , Gunderson J. G. , McGlashan T. H. , Grilo C. M.
Published: September 2010

Background

This study prospectively examined the natural clinical course of six anxiety disorders over 7 years of follow-up in individuals with personality disorders (PDs) and/or major depressive disorder. Rates of remission, relapse, new episode onset and chronicity of anxiety disorders were examined for specific associations with PDs.

Method

Participants were 499 patients with anxiety disorders in the Collaborative Longitudinal Personality Disorders Study, who were assessed with structured interviews for psychiatric disorders at yearly intervals throughout 7 years of follow-up. These data were used to determine probabilities of changes in disorder status for social phobia (SP), generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), panic disorder and panic disorder with agoraphobia.

Results

Estimated remission rates for anxiety disorders in this study group ranged from 73% to 94%. For those patients who remitted from an anxiety disorder, relapse rates ranged from 34% to 67%. Rates for new episode onsets of anxiety disorders ranged from 3% to 17%. Specific PDs demonstrated associations with remission, relapse, new episode onsets and chronicity of anxiety disorders. Associations were identified between schizotypal PD with course of SP, PTSD and GAD; avoidant PD with course of SP and OCD; obsessive-compulsive PD with course of GAD, OCD, and agoraphobia; and borderline PD with course of OCD, GAD and panic with agoraphobia.

Conclusions

Findings suggest that specific PD diagnoses have negative prognostic significance for the course of anxiety disorders underscoring the importance of assessing and considering PD diagnoses in patients with anxiety disorders.
Two Streams Mingling: The American Episcopal Church in the Anglican Communion
Authors: Podmore Colin
Published: September 2010

This article identifies and compares two ecclesiological ‘streams’ that coalesced when the Anglican Communion was definitively formed in 1867: the traditional western catholic ecclesiology of England and Ireland and the more democratic, egalitarian ecclesiology of the American Episcopal Church. These streams had already mingled in George Augustus Selwyn’s constitution for the New Zealand Church. Incorporation of laypeople into the Church of England’s synods represented further convergence. Nonetheless, different understandings of the role of bishops in church government are still reflected in attitudes to the respective roles in the Communion’s affairs of bishops and primates on the one hand and the more recent Anglican Consultative Council on the other. Differences between the two streams were noticeable at the 1867 Lambeth Conference. The efforts of Archbishops Davidson and Fisher, rooted in the work of Selwyn, to hold together what Selwyn called ‘the two branches of our beloved Church’ are praised.
Challenges of modeling depth‐integrated marine primary productivity over multiple decades: A case study at BATS and HOT
Authors: Saba Vincent S. , Friedrichs Marjorie A. M. , Carr Mary‐Elena , Antoine David , Armstrong Robert A. , Asanuma Ichio , Aumont Olivier , Bates Nicholas R. , Behrenfeld Michael J. , Bennington Val , Bopp Laurent , Bruggeman Jorn , Buitenhuis Erik T. , Church Matthew J. , Ciotti Aurea M. , Doney Scott C. , Dowell Mark , Dunne John , Dutkiewicz Stephanie , Gregg Watson , Hoepffner Nicolas , Hyde Kimberly J. W. , Ishizaka Joji , Kameda Takahiko , Karl David M. , Lima Ivan , Lomas Michael W. , Marra John , McKinley Galen A. , Mélin Frédéric , Moore J. Keith , Morel André , O'Reilly John , Salihoglu Baris , Scardi Michele , Smyth Tim J. , Tang Shilin , Tjiputra Jerry , Uitz Julia , Vichi Marcello , Waters Kirk , Westberry Toby K. , Yool Andrew
Published: September 2010

The performance of 36 models (22 ocean color models and 14 biogeochemical ocean circulation models (BOGCMs)) that estimate depth‐integrated marine net primary productivity (NPP) was assessed by comparing their output to in situ 14C data at the Bermuda Atlantic Time series Study (BATS) and the Hawaii Ocean Time series (HOT) over nearly two decades. Specifically, skill was assessed based on the models' ability to estimate the observed mean, variability, and trends of NPP. At both sites, more than 90% of the models underestimated mean NPP, with the average bias of the BOGCMs being nearly twice that of the ocean color models. However, the difference in overall skill between the best BOGCM and the best ocean color model at each site was not significant. Between 1989 and 2007, in situ NPP at BATS and HOT increased by an average of nearly 2% per year and was positively correlated to the North Pacific Gyre Oscillation index. The majority of ocean color models produced in situ NPP trends that were closer to the observed trends when chlorophyll‐a was derived from high‐performance liquid chromatography (HPLC), rather than fluorometric or SeaWiFS data. However, this was a function of time such that average trend magnitude was more accurately estimated over longer time periods. Among BOGCMs, only two individual models successfully produced an increasing NPP trend (one model at each site). We caution against the use of models to assess multiannual changes in NPP over short time periods. Ocean color model estimates of NPP trends could improve if more high quality HPLC chlorophyll‐a time series were available.
A calibrated advection‐aridity evaporation model requiring no humidity data
Authors: Crago Richard D. , Qualls Russell J. , Feller Meghan
Published: September 2010

A modified advection‐aridity model was tested with 24 h averaged data from the First ISLSCP (International Satellite Land Surface Climatology Project) Field Experiment‐87 and the Cooperative Atmospheric‐Surface Exchange Study (CASES) ‐97 experiments. Two modifications were made. First, the need for humidity measurements in the “drying power” term of the equation was circumvented by assuming the daily average specific humidity for a 24 h day is equal to the specific humidity at the minimum temperature during the day. When compared to measured latent heat fluxes, this modification resulted in no deterioration in advection‐aridity estimates compared to versions using measured humidity. A second modification followed previous researchers by formulating the drying power in the Penman equation using Monin‐Obukhov similarity (MOS) theory. However, this version calibrated kB−1 (≡ln(zo/zov) by setting the Priestley‐Taylor evapotranspiration rate equal (on average) to the Penman evapotranspiration on several moist days and solving for the value of kB−1 as the only unknown. The calibration involved no latent heat flux measurements. The results suggest that the advection‐aridity model performs modestly better in the calibrated MOS version than with Penman's original wind function. Further investigation is recommended because MOS theory accounts for varying momentum roughness lengths, and the calibration was not done under ideal (well‐watered or nearly saturated) conditions that deteriorated the results somewhat with the CASES data set.
Erosional control of the kinematics and geometry of fold‐and‐thrust belts imaged in a physical and numerical sandbox
Authors: Cruz L. , Malinski J. , Wilson A. , Take W. A. , Hilley G.
Published: September 2010

We investigate the effect of systematically varying erosion intensity (K) on the geometry and kinematics of fold‐and‐thrust belts modeled using equivalent conditions in physical and numerical experiments. Similar material properties and boundary conditions were used to compare numerical experiments to those modeled in the sandbox using an erosion rule that removes mass from the scaled sand wedges according to rates expected from bedrock fluvial incision. The geometry of both modeling approaches is quantitatively compared with that expected from analytical theory. The fold‐and‐thrust belt growth rate is inversely proportional to K and is well predicted by theory, except for the high erosion case, in which both the numerical and the experimental sandbox grows supercritically. A direct relationship exists between the erosion intensity and the number of fore‐shear bands and shear strain magnitude. The number of fore‐shear bands decreases, and their strain increases with erosion intensity. The results indicate that realistic and mechanistic erosion rules can be applied to physical experiments to model mass removal, and this approach opens up the possibility of calibrating strain history to erosion intensities for predictions in natural settings. Quantitative comparisons between the physical and numerical sandbox experiments indicate that deformation style and geometry of the thrust‐and‐fold belts are similar when identical rheologies and boundary conditions are used. This benchmarking suggests that numerical experiments realistically model conditions observed in the simple, cohesionless rheologies commonly employed in sandbox experiments. This suggests that numerical simulation may reliably model experimental deformation in geological situations that are difficult to represent in scaled experiments because of the different scales and rheologies of natural orogenic wedges.
Biochemical and cellular functions of P4 ATPases
Authors: van der Velden Lieke M. , van de Graaf Stan F. J. , Klomp Leo W. J.
Published: September 2010

P4 ATPases (subfamily IV P-type ATPases) form a specialized subfamily of P-type ATPases and have been implicated in phospholipid translocation from the exoplasmic to the cytoplasmic leaflet of biological membranes. Pivotal roles of P4 ATPases have been demonstrated in eukaryotes, ranging from yeast, fungi and plants to mice and humans. P4 ATPases might exert their cellular functions by combining enzymatic phospholipid translocation activity with an enzyme-independent action. The latter could be involved in the timely recruitment of proteins involved in cellular signalling, vesicle coat assembly and cytoskeleton regulation. In the present review, we outline the current knowledge of the biochemical and cellular functions of P4 ATPases in the eukaryotic membrane.
An All-Sky Atlas of Radio/X-ray Associations
Authors: Flesch E.
Published: September 2010

An all-sky comprehensive catalogue of calculated radio and X-ray associations to optical objects is presented. Included are X-ray sources from XMM-Newton, Chandra and ROSAT catalogues, radio sources from NVSS, FIRST and SUMSS catalogues, and optical data, identifications and redshifts from the APM, USNO-A, SDSS-DR7 and the extant literature. This ‘Atlas of Radio/X-ray Associations’ inherits many techniques from the predecessor Quasars.org (2004) catalogue, but object selection is changed and processing tweaked. Optical objects presented are those which are calculated with ≥40% confidence to be associated with radio/X-ray detections, totalling 602 570 objects in all, including 23 681 double radio lobe detections. For each of these optical objects I display the calculated percentage probabilities of its being a QSO, galaxy, star, or erroneous radio/X-ray association, plus any identification from the literature. The catalogue includes 105 568 uninvestigated objects listed as 40% to >99% likely to be a QSO. The catalogue is available at http://quasars.org/arxa.htm.
Metallicity Distributions In and Around Galaxies
Authors: De Lucia Gabriella
Published: September 2010

Metals are found in all baryonic phases and environments, and our knowledge of their distribution ‘in and around galaxies’ has significantly improved over the past few years. Theoretical work has shown that the fraction of metals in different baryonic components can vary significantly when different feedback schemes are adopted. Therefore, studies of element abundances provide important information about all gas-dynamical processes which determine the cosmic evolution of baryons. I give here a brief review of recent observational progress, describe the implications of recent theoretical studies, and discuss briefly future prospects.
A synthetic–natural hybrid oscillator in human cells
Authors: Toettcher Jared E. , Mock Caroline , Batchelor Eric , Loewer Alexander , Lahav Galit
Published: September 2010

Recent studies have shown that many cell-signaling networks contain interactions and feedback loops that give rise to complex dynamics. Synthetic biology has allowed researchers to construct and analyze well-defined signaling circuits exhibiting behavior that can be predicted and quantitatively understood. Combining these approaches—wiring natural network components together with engineered interactions—has the potential to precisely modulate the dynamics of endogenous signaling processes and control the cell decisions they influence. Here, we focus on the p53 signaling pathway as a template for constructing a tunable oscillator comprised of both natural and synthetic components in mammalian cells. We find that a reduced p53 circuit implementing a single feedback loop preserves some features of the full network's dynamics, exhibiting pulses of p53 with tightly controlled timing. However, in contrast to the full natural p53 network, these pulses are damped in individual cells, with amplitude that depends on the input strength. Guided by a computational model of the reduced circuit, we constructed and analyzed circuit variants supplemented with synthetic positive and negative feedback loops and subjected to chemical perturbation. Our work demonstrates that three important features of oscillator dynamics—amplitude, period, and the rate of damping—can be controlled by manipulating stimulus level, interaction strength, and feedback topology. The approaches taken here may be useful for the rational design of synthetic networks with defined dynamics, and for identifying perturbations that control dynamics in natural biological circuits for research or therapeutic purposes.
Systemic gut microbial modulation of bile acid metabolism in host tissue compartments
Authors: Swann Jonathan R. , Want Elizabeth J. , Geier Florian M. , Spagou Konstantina , Wilson Ian D. , Sidaway James E. , Nicholson Jeremy K. , Holmes Elaine
Published: September 2010

We elucidate the detailed effects of gut microbial depletion on the bile acid sub-metabolome of multiple body compartments (liver, kidney, heart, and blood plasma) in rats. We use a targeted ultra-performance liquid chromatography with time of flight mass-spectrometry assay to characterize the differential primary and secondary bile acid profiles in each tissue and show a major increase in the proportion of taurine-conjugated bile acids in germ-free (GF) and antibiotic (streptomycin/penicillin)-treated rats. Although conjugated bile acids dominate the hepatic profile (97.0 ± 1.5%) of conventional animals, unconjugated bile acids comprise the largest proportion of the total measured bile acid profile in kidney (60.0 ± 10.4%) and heart (53.0 ± 18.5%) tissues. In contrast, in the GF animal, taurine-conjugated bile acids (especially taurocholic acid and tauro-β-muricholic acid) dominated the bile acid profiles (liver: 96.0 ± 14.5%; kidney: 96 ± 1%; heart: 93 ± 1%; plasma: 93.0 ± 2.3%), with unconjugated and glycine-conjugated species representing a small proportion of the profile. Higher free taurine levels were found in GF livers compared with the conventional liver (5.1-fold;P< 0.001). Bile acid diversity was also lower in GF and antibiotic-treated tissues compared with conventional animals. Because bile acids perform important signaling functions, it is clear that these chemical communication networks are strongly influenced by microbial activities or modulation, as evidenced by farnesoid X receptor-regulated pathway transcripts. The presence of specific microbial bile acid co-metabolite patterns in peripheral tissues (including heart and kidney) implies a broader signaling role for these compounds and emphasizes the extent of symbiotic microbial influences in mammalian homeostasis.
Structural profiling of endogenous S-nitrosocysteine residues reveals unique features that accommodate diverse mechanisms for protein S-nitrosylation
Authors: Doulias Paschalis-Thomas , Greene Jennifer L. , Greco Todd M. , Tenopoulou Margarita , Seeholzer Steve H. , Dunbrack Roland L. , Ischiropoulos Harry
Published: September 2010

S-nitrosylation, the selective posttranslational modification of protein cysteine residues to form S-nitrosocysteine, is one of the molecular mechanisms by which nitric oxide influences diverse biological functions. In this study, unique MS-based proteomic approaches precisely pinpointed the site of S-nitrosylation in 328 peptides in 192 proteins endogenously modified in WT mouse liver. Structural analyses revealed that S-nitrosylated cysteine residues were equally distributed in hydrophobic and hydrophilic areas of proteins with an average predicted pK
a
of 10.01 ± 2.1. S-nitrosylation sites were over-represented in α-helices and under-represented in coils as compared with unmodified cysteine residues in the same proteins (χ
2
test,
P
< 0.02). A quantile–quantile probability plot indicated that the distribution of S-nitrosocysteine residues was skewed toward larger surface accessible areas compared with the unmodified cysteine residues in the same proteins. Seventy percent of the S-nitrosylated cysteine residues were surrounded by negatively or positively charged amino acids within a 6-Å distance. The location of cysteine residues in α-helices and coils in highly accessible surfaces bordered by charged amino acids implies site directed S-nitrosylation mediated by protein–protein or small molecule interactions. Moreover, 13 modified cysteine residues were coordinated with metals and 15 metalloproteins were endogenously modified supporting metal-catalyzed S-nitrosylation mechanisms. Collectively, the endogenous S-nitrosoproteome in the liver has structural features that accommodate multiple mechanisms for selective site-directed S-nitrosylation.
Gene-silencing reveals the functional significance of pheromone biosynthesis activating neuropeptide receptor (PBAN-R) in a male moth
Authors: Bober Rachel , Rafaeli Ada
Published: September 2010

The role of pheromone biosynthesis activating neuropeptide (PBAN) in the regulation of pheromone biosynthesis of several female moth species is well elucidated, but its role in the males has been a mystery for over two decades since its discovery from both male and female central nervous systems. In previous studies we have identified the presence of the gene transcript for the PBAN-G-protein coupled receptor (PBAN-R) in
Helicoverpa armigera
male hair-pencil-aedaegus complexes (male complexes), a tissue structurally homologous to the female pheromone gland. Moreover, we showed that this transcript is up-regulated during pupal-adult development, analogous to its regulation in the female pheromone-glands, thereby indicating a likely functional gene. Here we argue in favor of PBAN’s role in regulating the free fatty-acid components (myristic, palmitic, stearic, and oleic acids) and alcohol components (hexadecanol, cis-11 hexadecanol, and octadecanol) in male complexes. We demonstrate the diel periodicity in levels of male components, with peak titers occurring during the 7th–9th h in the scotophase, coincident with female pheromone production. In addition, we show significant stimulation of component levels by synthetic
Hez
PBAN. Furthermore, we confirm PBAN’s function in this tissue through knockdown of the PBAN-R gene using RNAi-mediated gene-silencing. Injections of
PBAN-R
dsRNA into the male hemocoel significantly inhibited levels of the various male components by 58%–74%. In conclusion, through gain and loss of function we revealed the functionality of the PBAN-R and the key components that are up-regulated by PBAN.
Rapid Communication: Readers Routinely Represent Implied Object Rotation: The Role of Visual Experience
Authors: Wassenburg Stephanie I. , Zwaan Rolf A.
Published: September 2010

We conducted an eye tracking experiment to investigate whether prior visual experience affects later language processing. We assessed the effects of previously encountered pictures of objects with a vertical or horizontal orientation on the later reading of sentences that implied an object's orientation. First-pass reading times were longer when participants read about an implied orientation that did not match the orientation of the previously seen picture than when the orientation matched. This suggests that a picture encountered 20 min earlier and incidental to the reading task influenced reading. These results have implications for theories of reading comprehension and embodied cognition.
Drosophila IAP antagonists form multimeric complexes to promote cell death
Authors: Sandu Cristinel , Ryoo Hyung Don , Steller Hermann
Published: September 2010

Apoptosis is a specific form of cell death that is important for normal development and tissue homeostasis. Caspases are critical executioners of apoptosis, and living cells prevent their inappropriate activation through inhibitor of apoptosis proteins (IAPs). In Drosophila, caspase activation depends on the IAP antagonists, Reaper (Rpr), Head involution defective (Hid), and Grim. These proteins share a common motif to bind Drosophila IAP1 (DIAP1) and have partially redundant functions. We now show that IAP antagonists physically interact with each other. Rpr is able to self-associate and also binds to Hid and Grim. We have defined the domain involved in self-association and demonstrate that it is critical for cell-killing activity in vivo. In addition, we show that Rpr requires Hid for recruitment to the mitochondrial membrane and for efficient induction of cell death in vivo. Both targeting of Rpr to mitochondria and forced dimerization strongly promotes apoptosis. Our results reveal the functional importance of a previously unrecognized multimeric IAP antagonist complex for the induction of apoptosis.
IAP inhibitors enhance co-stimulation to promote tumor immunity
Authors: Dougan Michael , Dougan Stephanie , Slisz Joanna , Firestone Brant , Vanneman Matthew , Draganov Dobrin , Goyal Girija , Li Weibo , Neuberg Donna , Blumberg Richard , Hacohen Nir , Porter Dale , Zawel Leigh , Dranoff Glenn
Published: September 2010

The inhibitor of apoptosis proteins (IAPs) have recently been shown to modulate nuclear factor κB (NF-κB) signaling downstream of tumor necrosis factor (TNF) family receptors, positioning them as essential survival factors in several cancer cell lines, as indicated by the cytotoxic activity of several novel small molecule IAP antagonists. In addition to roles in cancer, increasing evidence suggests that IAPs have an important function in immunity; however, the impact of IAP antagonists on antitumor immune responses is unknown. In this study, we examine the consequences of IAP antagonism on T cell function in vitro and in the context of a tumor vaccine in vivo. We find that IAP antagonists can augment human and mouse T cell responses to physiologically relevant stimuli. The activity of IAP antagonists depends on the activation of NF-κB2 signaling, a mechanism paralleling that responsible for the cytotoxic activity in cancer cells. We further show that IAP antagonists can augment both prophylactic and therapeutic antitumor vaccines in vivo. These findings indicate an important role for the IAPs in regulating T cell–dependent responses and suggest that targeting IAPs using small molecule antagonists may be a strategy for developing novel immunomodulating therapies against cancer.
Damage to nearby divertor components of ITER-like devices during giant ELMs and disruptions
Authors: Sizyuk V. , Hassanein A.
Published: September 2010

During normal operation of the high confinement mode in future ITER devices, edge-localized modes (ELMs) are a potential threat to the divertor components lifetime and plasma contamination. To predict the outcome of the direct ELM plasma impact on the divertor plate, conversion of plasma energy into radiation in the shielding layer, and then the resulting energy deposition of radiation flux to the surrounding areas, comprehensive physical and numerical models are developed and implemented in the HEIGHTS package. The energy deposition, divertor material erosion, resulting vapour plasma temperature and density evolution, and subsequently the resulting radiation, its transport and deposition around the divertor area are calculated for the predicted ELM and disruption parameters and for the prospective full ITER geometry. The initial simulation results showed that the disrupted plasma power density at the original divertor location and vapour radiation fluxes on nearby dome locations can have the same order of magnitude. The simulation results of the integrated modelling indicate a significant potential damage of the divertor nearby surfaces during giant ELMs and disruption impacts for ITER-like parameters and geometry.
Satellite Remote Sensing of Wheat Infected byWheat streak mosaic virus
Authors: Mirik M. , Jones D. C. , Price J. A. , Workneh F. , Ansley R. J. , Rush C. M.
Published: September 2010

The prevalence of wheat streak mosaic, caused by Wheat streak mosaic virus, was assessed using Landsat 5 Thematic Mapper (TM) images in two counties of the Texas Panhandle during the 2005–2006 and 2007–2008 crop years. In both crop years, wheat streak mosaic was widely distributed in the counties studied. Healthy and diseased wheat were separated on the images using the maximum likelihood classifier. The overall classification accuracies were between 89.47 and 99.07% for disease detection when compared to “ground truth” field observations. Omission errors (i.e., pixels incorrectly excluded from a particular class and assigned to other classes) varied between 0 and 12.50%. Commission errors (i.e., pixels incorrectly assigned to a particular class that actually belong to other classes) ranged from 0 to 23.81%. There were substantial differences between planted wheat acreage reported by the United States Department of Agriculture-National Agricultural Statistics Service (USDA-NASS) and that detected by image analyses. However, harvested wheat acreage reported by USDA-NASS and that detected by image classifications were closely matched. These results indicate that the TM image can be used to accurately detect and quantify incidence of wheat streak mosaic over large areas. This method appears to be one of the best currently available for identification and mapping disease incidence over large and remote areas by offering a repeatable, inexpensive, and synoptic strategy during the course of a growing season.
Population Genetic Analysis of Tomato spotted wilt virus on Peanut in North Carolina and Virginia
Authors: Kaye A. C. , Moyer J. W. , Parks E. J. , Carbone I. , Cubeta M. A.
Published: September 2010

Exploring the genetic diversity and evolutionary history of plant viruses is critical to understanding their ecology and epidemiology. In this study, maximum-likelihood and population genetics-based methods were used to investigate the population structure, genetic diversity, and sources of genetic variation in field isolates of Tomato spotted wilt virus (TSWV) from peanut in North Carolina and Virginia. Selected regions of the nucleocapsid, movement, and RNA-dependent RNA polymerase genes were amplified and sequenced to identify haplotypes and infer genetic relationships between isolates of TSWV with heuristic methods. The haplotype structure of each locus consisted of 1 or 2 predominant haplotypes and >100 haplotypes represented by a single isolate. No specific haplotypes were associated with geographic area, peanut cultivar, or year of isolation. The population was panmictic at the regional level and high levels of genetic diversity were observed among isolates. There was evidence for positive selection on single amino acids in each gene on a background of predominant purifying selection acting upon each locus. The results of compatibility analyses and the persistence of specific gene sequences in isolates collected over three field seasons suggest that recombination was occurring in the population. Estimates of the population mutation rate suggest that mutation has had a significant effect on the shaping of this population and, together with purifying selection, these forces have been the predominant evolutionary forces influencing the TSWV population in peanut in North Carolina and Virginia.
Mechanistically Compatible Mixtures of Bacterial Antagonists Improve Biological Control of Fire Blight of Pear
Authors: Stockwell V. O. , Johnson K. B. , Sugar D. , Loper J. E.
Published: September 2010

Mixtures of biological control agents can be superior to individual agents in suppressing plant disease, providing enhanced efficacy and reliability from field to field relative to single biocontrol strains. Nonetheless, the efficacy of combinations of Pseudomonas fluorescens A506, a commercial biological control agent for fire blight of pear, and Pantoea vagans strain C9-1 or Pantoea agglomerans strain Eh252 rarely exceeds that of individual strains. A506 suppresses growth of the pathogen on floral colonization and infection sites through preemptive exclusion. C9-1 and Eh252 produce peptide antibiotics that contribute to disease control. In culture, A506 produces an extracellular protease that degrades the peptide antibiotics of C9-1 and Eh252. We hypothesized that strain A506 diminishes the biological control activity of C9-1 and Eh252, thereby reducing the efficacy of biocontrol mixtures. This hypothesis was tested in five replicated field trials comparing biological control of fire blight using strain A506 and A506 aprX::Tn5, an extracellular protease-deficient mutant, as individuals and combined with C9-1 or Eh252. On average, mixtures containing A506 aprX::Tn5 were superior to those containing the wild-type strain, confirming that the extracellular protease of A506 diminished the biological control activity of C9-1 and Eh252 in situ. Mixtures of A506 aprX::Tn5 and C9-1 or Eh252 were superior to oxytetracycline or single biocontrol strains in suppressing fire blight of pear. These experiments demonstrate that certain biological control agents are mechanistically incompatible, in that one strain interferes with the mechanism by which a second strain suppresses plant disease. Mixtures composed of mechanistically compatible strains of biological control agents can suppress disease more effectively than individual biological control agents.
Effects of Different Potato Cropping System Approaches and Water Management on Soilborne Diseases and Soil Microbial Communities
Authors: Larkin Robert P. , Honeycutt C. Wayne , Griffin Timothy S. , Olanya O. Modesto , Halloran John M. , He Zhongqi
Published: September 2010

Four different potato cropping systems, designed to address specific management goals of soil conservation, soil improvement, disease suppression, and a status quo standard rotation control, were evaluated for their effects on soilborne diseases of potato and soil microbial community characteristics. The status quo system (SQ) consisted of barley underseeded with red clover followed by potato (2-year). The soil-conserving system (SC) featured an additional year of forage grass and reduced tillage (3-year, barley/timothy–timothy–potato). The soil-improving system (SI) added yearly compost amendments to the SC rotation, and the disease-suppressive system (DS) featured diverse crops with known disease-suppressive capability (3-year, mustard/rapeseed–sudangrass/rye–potato). Each system was also compared with a continuous potato control (PP) and evaluated under both irrigated and nonirrigated conditions. Data collected over three potato seasons following full rotation cycles demonstrated that all rotations reduced stem canker (10 to 50%) relative to PP. The SQ, SC, and DS systems reduced black scurf (18 to 58%) relative to PP; SI reduced scurf under nonirrigated but not irrigated conditions; and scurf was lower in DS than all other systems. The SQ, SC, and DS systems also reduced common scab (15 to 45%), and scab was lower in DS than all other systems. Irrigation increased black scurf and common scab but also resulted in higher yields for most rotations. SI produced the highest yields under nonirrigated conditions, and DS produced high yields and low disease under both irrigation regimes. Each cropping system resulted in distinctive changes in soil microbial community characteristics as represented by microbial populations, substrate utilization, and fatty acid methyl-ester (FAME) profiles. SI tended to increase soil moisture, microbial populations, and activity, as well result in higher proportions of monounsaturated FAMEs and the FAME biomarker for mycorrhizae (16:1 ω6c) relative to most other rotations. DS resulted in moderate microbial populations and activity but higher substrate richness and diversity in substrate utilization profiles. DS also resulted in relatively higher proportions of FAME biomarkers for fungi (18:2 ω6c), actinomycetes, and gram-positive bacteria than most other systems, whereas PP resulted in the lowest microbial populations and activity; substrate richness and diversity; proportions of monounsaturated and polyunsaturated FAME classes; and fungal, mycorrhizae, and actinomycete FAME biomarkers of all cropping systems. Overall, soil water, soil quality, and soilborne diseases were all important factors affecting productivity, and cropping systems addressing these constraints improved production. Cropping system approaches will need to balance these factors to achieve sustainable production and disease management.
Genetic Structure of Phytophthora infestans Populations in China Indicates Multiple Migration Events
Authors: Guo Liyun , Zhu Xiao-Qiong , Hu Chia-Hui , Ristaino Jean Beagle
Published: September 2010

One hundred isolates of Phytophthora infestans collected from 10 provinces in China between 1998 and 2004 were analyzed for mating type, metalaxyl resistance, mitochondrial DNA (mtDNA) haplotype, allozyme genotype, and restriction fragment length polymorphism (RFLP) with the RG-57 probe. In addition, herbarium samples collected in China, Russia, Australia, and other Asian countries were also typed for mtDNA haplotype. The Ia haplotype was found during the first outbreaks of the disease in China (1938 and 1940), Japan (1901, 1930, and 1931), India (1913), Peninsular Malaysia (1950), Nepal (1954), The Philippines (1910), Australia (1917), Russia (1917), and Latvia (1935). In contrast, the Ib haplotype was found after 1950 in China on both potato and tomato (1952, 1954, 1956, and 1982) and in India (1968 and 1974). Another migration of a genotype found in Siberia called SIB-1 (Glucose-6-phosphate isomerase [Gpi] 100/100, Peptidase [Pep] 100/100, IIa mtDNA haplotype) was identified using RFLP fingerprints among 72% of the isolates and was widely distributed in the north and south of China and has also been reported in Japan. A new genotype named CN-11 (Gpi 100/111, Pep 100/100, IIb mtDNA haplotype), found only in the south of China, and two additional genotypes (Gpi 100/100, Pep 100/100, Ia mtDNA haplotype) named CN-9 and CN-10 were identified. There were more diverse genotypes among isolates from Yunnan province than elsewhere. The SIB-1 (IIa) genotype is identical to those from Siberia, suggesting later migration of this genotype from either Russia or Japan into China. The widespread predominance of SIB-1 suggests that this genotype has enhanced fitness compared with other genotypes found. Movement of the pathogen into China via infected seed from several sources most likely accounts for the distribution of pathogen genotypes observed. MtDNA haplotype evidence and RFLP data suggest multiple migrations of the pathogen into China after the initial introduction of the Ia haplotype in the 1930s.