bluuebunny/crossref_metadata_2025 huggingface dataset:
Gallic acid, a histone acetyltransferase inhibitor, suppresses β‐amyloid neurotoxicity by inhibiting microglial‐mediated neuroinflammation
Authors: Kim Mi‐Jeong , Seong Ah‐Reum , Yoo Jung‐Yoon , Jin Cheng‐Hao , Lee Yoo‐Hyun , Kim Young Jun , Lee Jeongmin , Jun Woo Jin , Yoon Ho‐Geun
Published: October 2011

Scope: We examined the biological effect of gallic acid (GA) as a nuclear factor (NF)‐κB acetyltransferase inhibitor on microglial‐mediated β‐amyloid neurotoxicity and restorative effects on the Aβ‐induced cognitive dysfunction.

Methods and results: The protective effects of GA on the survival of neuronal cells were assessed with an MTT assay and a co‐culture system. For the co‐culture experiments, both BV‐2 and primary microglia cells were treated with GA prior to Aβ stimulation, and conditioned media were transferred to Neuro‐2A cells. The mRNA and protein levels of inflammatory cytokines in both microglia and Neuro‐2A cells were assessed with real‐time polymerase chain reaction and western blotting. Inhibition of nuclear factor kappa B (NF‐κB) acetylation with GA treatment resulted in reduced cytokine production in microglia cells and protection of neuronal cells from Aβ‐induced neurotoxicity. Furthermore, we observed a restorative effect of GA on Aβ‐induced cognitive dysfunction in mice with Y‐maze and passive avoidance tests. Finally, we found that GA treatment efficiently blocked neuronal cell death by downregulating the expression of cytokines and the in vivo levels of NF‐κB acetylation.

Conclusion: These results suggest that selective inhibition of NF‐κB acetylation by the histone acetyltransferase inhibitor GA is a possible therapeutic approach for alleviating the inflammatory progression of Alzheimer disease.
Decomposition‐based quantitative electromyography in the evaluation of muscular dystrophy severity
Authors: Derry Kendra L. , Venance Shannon L. , Doherty Timothy J.
Published: November 2011

Introduction: Electromyography is useful in the diagnosis of myopathies, but its utility in determining disease severity requires further investigation. In this study we aimed to determine whether decomposition‐based quantitative electromyography (DQEMG) could indicate the severity of involvement in a cohort of patients with muscular dystrophies (MDs). Methods: Fifteen patients with facioscapulohumeral (FSHD), limb‐girdle (LGMD), and Becker (BMD) muscular dystrophy, and 7 healthy controls, participated in this investigation. Knee extensor isometric strength differentiated the “more severe” and “less severe” MD groups. The vastus lateralis (VL), biceps brachii (BB), and tibialis anterior (TA) muscle groups were investigated using DQEMG. Results: All muscles from the MD group showed changes in mean MUP (motor unit potential) AAR (area‐to‐amplitude ratio), and turns, compared with controls (P < 0.05). More severely affected muscles (VL and BB) also had shortened mean MUP durations compared with controls (P < 0.01). Conclusions: DQEMG was capable of indicating the severity of MD involvement, as changes in MUP morphology reflected the progressive nature of the disease. Muscle Nerve, 2012
Localization of generalized eigenvalues by Cartesian ovals
Authors: Kostić V. , Varga R. S. , Cvetković L.
Published: November 2011

In this paper, we consider the localization of generalized eigenvalues, and we discuss ways in which the Gersgorin set for generalized eigenvalues can be approximated. Earlier, Stewart proposed an approximation using a chordal metric. We will obtain here an improved approximation, and using the concept of generalized diagonal dominance, we prove that the new approximation has some of the basic properties of the original Geršgorin set, which makes it a handy tool for generalized eigenvalue localization. In addition, an isolation property is proved for both the generalized Geršgorin set and its approximation. Copyright © 2011 John Wiley & Sons, Ltd.
Polypropylene/organically modified Sabah montmorillonite nanocomposites: Surface modification and nanocomposites characterization
Authors: Balakrishnan Harintharavimal , Ibrahim Muthmirah , Wahit Mat Uzir , Hassan Azman
Published: November 2011

The aim of the work is to extract, purify, and organically modify montmorillonite (MMT) of Lahad Datu, Sabah bentonite. The octadecylamine treated Sabah MMT (S‐OMMT) (2–8 wt%) was then melt blended with polypropylene (PP) and maleated polypropylene (PPgMAH) (10 wt%) via single screw nanomixer extruder followed by injection molding into test samples to examine the mechanical, thermal, and morphological properties of PP/S‐OMMT nanocomposites. Unmodified Sabah MMT (S‐MMT) and commercial grade MMT (Nanomer 1.30P) filled PP nanocomposites were also characterized for comparison purpose. X‐ray diffraction results showed that the interlayer spacing of S‐MMT increased after organic modification as Fourier transform infra‐red and elemental analysis evidenced the presence of octadecylamine. PP/S‐OMMT nanocomposites showed a better dispersion and strength compared to PP/Nanomer 1.30P nanocomposites due to its smaller MMT platelet size. differential scanning calorimetry and Thermogravimetry analysis revealed that the thermal stability and crystallinity of neat PP improved with the addition of all types of MMT. Dynamic mechanical analyzer showed that PP nanocomposites have higher storage modulus (E′) values than the neat PP over the whole temperature range. The new PP/S‐OMMT nanocomposites showed a comparable performance with PP/Nanomer 1.30P nanocomposites exhibiting promising future applications of S‐MMT in polymer/MMT nanocomposites. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Interfacial micromechanics and effect of moisture on fluorinated epoxy carbon fiber composites
Authors: Pandey Gajendra , Kareliya Chirag , Hinkley Jeffrey , Singh Raman P.
Published: November 2011

Carbon fiber composites have witnessed an increased application in aerospace and other civil structures due to their excellent structural properties such as specific strength and stiffness. However, unlike other structural materials, carbon fiber composites have not been as widely studied. Hence, their increased application is also accompanied with a serious concern about their long‐term durability. Many of these applications are exposed to multiple environments such as moisture, temperature, and UV radiation. Composites based on conventional epoxies readily absorb moisture. However, recently synthesized fluorinated epoxies show reduced moisture absorption and hence potentially better long‐term durability. The aim of this project is to study the effect of moisture absorption on fluorinated‐epoxy‐based carbon fiber composites and their comparison with conventional epoxy carbon fiber‐based composites. Microbond tests are performed on fluorinated and nonfluorinated epoxy‐based single fiber samples before and after boiling water degradation. It is found that fluorinated epoxy‐based single fiber coupons showed relatively reduced degradation of interface when compared with the nonfluorinated epoxy single fiber coupons. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Eine Legende wird neu geboren
Authors: Fuchs Guido W.
Published: November 2011

Im Jahre 1790 gründet der Naturforscher Friedrich Gren das Journal der Physik, das er bis kurz vor seinem Tod 1798 führt. Das von ihm begonnene Werk führt Ludwig Gilbert ab 1799 als Annalen der Physik fort. In der Folgezeit entwickelt sich die Zeitschrift zu einer der traditionsreichsten und angesehensten Physikzeitschriften der Welt. Der Ruhm der Annalen gipfelt Anfang des 20. Jahrhunderts in den bahnbrechenden Veröffentlichungen von Max Planck und Albert Einstein. Die Annalen überstehen beide Weltkriege und die anschließende Teilung Deutschlands. Seit der deutschen Wiedervereinigung erscheinen weiterhin regelmäßig Beiträge führender Wissenschaftler. Im Januar 2012 wird die Zeitschrift einen Neustart erleben.
While my guitar gently weeps
Authors: Hauck Matthias
Published: November 2011

In der vorgestellten Studie gelangen es, auf Grundlage physikalischer Resonanzanalysen und psychoakustischer Testmethoden Qualitätskriterien für akustische Stahlsaitengitarren abzuleiten. Hierbei wurde das Resonanzverhalten der Instrumente in einer Weise untersucht, wie sie von Musikern gespielt werden. Die dadurch verhältnismäßig einfach auszuführenden Analysen machen sie auch für einen modernen Physikunterricht in den Schulen attraktiv.
Zersplitterndes Holz auf rohen Eiern
Authors: Vollmer Michael , Möllmann Klaus‐Peter
Published: November 2011

Manch einer kennt die Show‐Darbietungen, bei denen ein Sportler mit bloßen Händen oder Füßen Mauersteine oder Holzplatten zertrümmert. Schon lange sind die physikalischen Hintergründe der Bruchmechanik und Dynamik bekannt, die diese scheinbar unmöglichen Kunststücke erlauben. Dennoch steht das Verständnis der physikalischen Bewegungsgesetze häufig im Gegensatz zu unserer Alltagserwartung.
Ein Leben im Beschleunigerlabor
Authors: Loos Andreas
Published: November 2011

Sehr beschleunigt wirkt seine Ausbildung am Anfang nicht, eher im Gegenteil: Das Gymnasium besucht er zwei Jahre länger, weil die Universität geschlossen hat – es ist Krieg. Er nutzt die Zeit für Elektronik‐Basteleien und startet mit Verspätung ein Studium der technischen Physik in Delft. (Jahrzehnte später wird er bedauern, dass sein Physikwissen dadurch “notwendigerweise etwas beschränkt gewesen” und er dadurch “etwas amateurhaft” sei.) Nach Abschluss des Studiums nimmt er eine Stelle in einem Forschungslabor von Philips an, um an der Entwicklung von Elektronenmikroskopen mitzuarbeiten.
Die Creme, die aus der Kälte
Authors: Vilgis Thomas
Published: November 2011

Eier einzufrieren ist nicht unbedingt das Naheliegendste, aber dieses Vorgehen liefert eine einzigartige cremige Struktur des Eigelbs, dessen Textur vielfältig eingesetzt werden kann. Der Grund dafür ist das außergewöhnliche Verhalten der LDL‐Partikel (Low Density Lipoproteins) und deren einhüllenden Proteine (Apoproteine), die für das “Gelieren” des Eigelbs beim Einfrieren verantwortlich sind.
Two‐photon excitation and optical limiting in polyfluorene derivatives
Authors: Correa Daniel S. , De Boni Leonardo , Nowacki Bruno , Grova Isabel , Fontes Bruno D. , Rodrigues Paula C. , Tozoni José R. , Akcelrud Leni , Mendonça Cleber R.
Published: October 2011

Fluorene‐based polymers are widely known materials due to a combination of features such as photoluminescence and electroluminescence, oxidative stability, and film‐forming ability. However, studies reporting nonlinear optical properties in this class of conjugated polymer are scarce. Here, we report a new class of polyfluorene derivatives poly(9,9′‐n‐dihexyl‐2,7‐fluorenedilvinylene‐alt‐1,4‐phenylenevinylene), poly(9,9′‐n‐dihexyl‐2,7‐fluorenedilvinylene‐alt‐2,5‐thiophene), and poly[(9,9‐di‐hexylfluorenediylvinylene‐alt‐1,4‐phenylenevinylene)‐co‐((9,9′‐(3‐t‐butylpropanoate) fluorene‐1,4‐phenylene)] displaying high two‐photon absorption (2PA) in the spectral range from a 490 to 1100 nm. The 2PA cross‐section peak values for these materials are as high as 3000 Göppert Mayer (1 GM = 1 × 10−50 cm4 s/photon), which is related to the high degree of conjugation along the polymer backbone. The polymers that were used in this study presented a strong two‐photon luminescence and also displayed optical limiting behavior, which, in combination with their well‐established properties, make them highly suitable for nonlinear optical devices. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 50: 148–153, 2012
Stable and good color purity white light‐emitting devices based on random fluorene/spirofluorene copolymers doped with iridium complex
Authors: Wang Hong‐Yu , Qian Qun , Lin Kun‐Hua , Peng Bo , Huang Wei , Liu Feng , Wei Wei
Published: October 2011

Conjugated polymers PSNFP and PSNFF based on naphthalene‐containing spirofluorene structure and 9,9‐dioctylfluorene, 2,5‐dioctylbezene were designed and synthesized for light emitting applications. These two polymers show good blue emission both in solution and thin film. Thermal gravimetric analysis reveals they have good thermal stability with the decomposition temperature higher than 400 °C. Electrochemistry characterization shows that both of these polymers have a large band gap and deep highest occupied molecular orbital, which are important features for phosphorescent host materials. White light‐emitting diodes were fabricated by using PSNFF as the host material, containing two typical phosphorescent Ir complex dopants: green emitter Ir(mppy)3 and red emitter Ir(piq)2. The color coordinate CIE stayed nearly constant, changed from (0.32, 0.31) to (0.28, 0.31) when the current density varied from 2 to 20 mA cm−2. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Imaging of phase segregation in gradient copolymers: Island and hole surface topography
Authors: Mok Michelle M. , Torkelson John M.
Published: October 2011

Application of traditional block copolymer microscopy techniques to gradient copolymers yields limited results, due to the low compositional contrast provided from the sinusoidal composition profiles of their phase segregated nanostructures. In contrast, optical microscopy and profilometry allow for the first direct visualization of their phase segregation properties through surface features formed in annealed thin films. Three comonomer systems are studied; one block and one gradient copolymer are compared for each system. Island/hole topography is observed in all block cases. Of the three gradient copolymers, one showed no pattern development and two showed emergence of island/hole patterns, which coarsen over initial annealing and then appear to anneal away. These results are related to the lower driving force for phase segregation from gradient sequencing, which lowers the potential of gradient copolymers to form island/hole patterns and also to pin any patterns formed. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Effects of Reactor Packing Materials on H2 Production by CO2 Reforming of CH4 in a Dielectric Barrier Discharge
Authors: Gallon Helen J. , Tu Xin , Whitehead J. Christopher
Published: November 2011

Non‐thermal plasma has been investigated for CO2 reforming of CH4 in a coaxial DBD reactor with different reactor packing materials placed into the discharge gap. Both the chemical and physical effects on reaction performance have been examined for the addition of quartz wool, γ‐Al2O3 and zeolite 3A, in order to gain a better understanding of plasma interactions with materials during CH4 reforming reactions. Quartz wool was found to enhance the conversion of CH4 and improve H2 yields as a result of changes in the physical properties of the discharge; electrical measurements showed an increase in the intensity of microdischarge filaments over quartz wool. In the presence of Al2O3 and zeolite 3A, the discharge intensity was reduced and consequently CH4 and CO2 conversions were lower for these materials. However, in the presence of zeolite 3A improved selectivities towards H2 and light hydrocarbons acetylene/ethylene were obtained and formation of liquid hydrocarbons was inhibited due to shape‐selectivity determined by the zeolite pore size.

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Crystal structure of bacteriophage ϕNIT1 zinc peptidase PghP that hydrolyzes γ‐glutamyl linkage of bacterial poly‐γ‐glutamate
Authors: Fujimoto Zui , Kimura Keitarou
Published: October 2011

Poly‐γ‐glutamate hydrolase P (PghP) of Bacillus subtilis bacteriophage ΦNIT1 hydrolyzes the γ‐glutamyl peptide linkage of extracellular poly‐γ‐glutamate produced by bacilli, which facilitates infection and propagation of phage progenies. Crystal structure of PghP was determined at a resolution of 1.9 Å. Structure of PghP was elucidated as a globular protein with an open α/β mixed core structure and a seven‐stranded parallel/anti‐parallel β‐sheet. The β‐sheet contained a core four‐stranded parallel β‐sheet. A zinc‐binding motif, His‐Glu‐His, was identified at the C‐terminal end of the β‐sheet. Structure analysis demonstrated that PghP, which had not been previously classified into any peptidase/protease family due to lack of amino acid sequence similarity with known enzymes, had a catalytic center containing a zinc ion and an overall topology resembling mammalian carboxypeptidase A and related enzymes. Structural comparisons indicated important amino acid residues of PghP for catalysis and recognition of the γ‐peptide bond of poly‐γ‐glutamate, which was confirmed by site‐directed mutagenesis of PghP. Proteins 2011. © 2012 Wiley Periodicals, Inc.
Selection for resistance, reversion towards susceptibility and synergism of chlorantraniliprole and spinetoram in obliquebanded leafroller, Choristoneura rosaceana (Lepidoptera: Tortricidae)
Authors: Sial Ashfaq A , Brunner Jay F
Published: November 2011

BACKGROUND: Obliquebanded leafroller, Choristoneura rosaceana (Harris), is an economic pest of pome fruits throughout North America. Repeated applications of broad‐spectrum insecticides have resulted in the development of resistance, cross‐resistance and multiple resistance in this pest. Studies were conducted to determine the possibility of resistance evolution, stability of resistance and the effect of metabolic synergists on toxicity of new reduced‐risk insecticides chlorantraniliprole and spinetoram in C. rosaceana.

RESULTS: Larvae of C. rosaceana were selected for resistance to chlorantraniliprole and spinetoram in the laboratory. Significant levels of resistance to each insecticide were observed after 12 generations of selection. In the absence of selection pressure, susceptibility of a subset of larvae from both chlorantraniliprole‐ and spinetoram‐selected populations reverted to preselection levels after five and six generations respectively, indicating that resistance to both chlorantraniliprole and spinetoram was unstable in C. rosaceana. In synergist bioassays performed after 12 generations of selection, S,S,S‐tributylphosphoro trithioate (DEF) and piperonyl butoxide (PBO) synergized the toxicity of chlorantraniliprole and spinetoram respectively, suggesting the involvement of esterases in chlorantraniliprole resistance and the involvement of mixed‐function oxidases in spinetoram resistance.

CONCLUSION: These findings suggest that chlorantraniliprole and spinetoram could be incorporated into C. rosaceana resistance management programs by using rotational strategies. Copyright © 2011 Society of Chemical Industry
Effect of introducing a short amyloidogenic sequence from the Aβ peptide at the N‐terminus of 18‐residue amphipathic helical peptides
Authors: SivakamaSundari Chandrasekaran , Rukmani Sridharan , Nagaraj Ramakrishnan
Published: November 2011

Fibril formation is the hallmark of pathogenesis in Alzheimer's disease and other amyloid disorders caused by conformational alterations leading to the aggregation of soluble monomers. Aβ40 self‐associates to form amyloid fibrils. Its central seven‐residue segment KLVFFAE (Aβ16–22), which is thought to be crucial for fibril formation of the full‐length peptide, forms fibrils even in isolation. Context‐dependent induction of amyloid formation by such sequences in peptides, which otherwise do not have that propensity, is of considerable interest. We have examined the effect of introducing the Aβ16–22 sequence at the N‐terminus of two amphipathic helical 18‐residue peptides Ac‐WYSEMKRNVQRLERAIEE‐am and Ac‐KQLIRFLKRLDRNLWGLA‐am, which have high average hydrophobic moment <μH> values but have net charges of 0 and +4, respectively, at neutral pH. Upon incubation in aqueous buffer, fibril‐like aggregates were discernible by transmission electron microscopy for the peptide with only 0 net charge, which also displayed ThT binding and β‐structure. Although both the sequences have been derived from amphipathic helical segments in globular proteins and possess high average hydrophobic moments, the +4 charge peptide lacks the ability to form fibrils, while the peptide with 0 charge has the tendency to form fibrillar structures. Variation in the net charge and the presence of several glutamic acids in the sequence of the peptide with net charge 0 appear to favor the formation of fibrils when the Aβ16–22 sequence is attached at the N‐terminus. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
A global blended tropopause based on ERA data. Part II: Trends and tropical broadening
Authors: Wilcox L. J. , Hoskins B. J. , Shine K. P.
Published: October 2011

A new tropopause definition involving a flow‐dependent blending of the traditional thermal tropopause with one based on potential vorticity has been developed and applied to the European Centre for Medium‐Range Weather Forecasts (ECMWF) reanalyses (ERA), ERA‐40 and ERA‐Interim. Global and regional trends in tropopause characteristics for annual and solsticial seasonal means are presented here, with emphasis on significant results for the newer ERA‐Interim data for 1989–2007. The global‐mean tropopause is rising at a rate of 47 m per decade, with pressure falling at 1.0 hPa per decade and temperature falling at 0.18 K per decade. The Antarctic tropopause shows decreasing heights, warming and increasing westerly winds. The Arctic tropopause also shows a warming, but with decreasing westerly winds. In the Tropics the trends are small, but at the latitudes of the subtropical jets they are almost double the global values. It is found that these changes are mainly concentrated in the eastern hemisphere. Previous and new metrics for the rate of broadening of the Tropics, based on both height and wind, give trends in the range 0.9–2.2° per decade. For ERA‐40 the global height and pressure trends for the period 1979–2001 are similar: 39 m per decade and −0.8 hPa per decade. These values are smaller than those found from the thermal tropopause definition with this dataset, as was used in most previous studies. Copyright © 2011 Royal Meteorological Society
‘I Was Just Screeching!’: Comparing Child and Parent Derived Measures of Distress
Authors: Peterson Carole , Noel Melanie
Published: November 2011

Two studies explored relationships between children's (2–13 years old) descriptions of how much they had cried and two other ways of assessing children's distress during injuries and subsequent hospital treatment, one parent‐generated and the other child‐generated. In the first study, 201 2‐ to 13‐year‐old children's descriptions of crying were compared with parental ratings of child distress, and in the second, these two measures plus a Faces Pain Scale were compared for 71 2‐ to 6‐year‐olds. Children's self‐descriptions of crying were highly similar to parental ratings at all ages, but the Faces Pain Scale had less similarity to other measures, especially for younger preschoolers. Findings suggest that children's self‐descriptions of emotional reactions may be a useful tool for assessing children's distress for real‐world events with no adult witnesses. Copyright © 2011 John Wiley & Sons, Ltd.
Work Hours and Work–Family Conflict: The Double‐edged Sword of Involvement in Work and Family
Authors: Matthews Russell A. , Swody Cathleen A. , Barnes‐Farrell Janet L.
Published: November 2011

In this study, we examine the role of work hours in a model that incorporates involvement in both work and family with experiences of work–family conflict and subjective well‐being. Self‐report data were collected from 383 full‐time employees and analysed using structural equation modelling techniques. Results demonstrate that role salience was positively related to behavioural involvement with work and with family. In turn, behavioural family involvement was negatively related to work hours and family‐to‐work conflict, while behavioural work involvement was positively related to work hours. Behavioural family involvement was also positively related to life satisfaction. Finally, both family‐to‐work conflict and end‐of‐workday strain were negatively related to life satisfaction. Our results provide insight into unexpected problems that might arise when employees place overly high importance on work and work long hours. This study serves as a foundation for researchers to examine the interplay of time spent with work and family with other aspects of the work–family interface. Copyright © 2011 John Wiley & Sons, Ltd.
Attribution of climate variations and trends to human influences and natural variability
Authors: Trenberth Kevin E.
Published: November 2011

Past attribution studies of climate change have assumed a null hypothesis of no role of human activities. The challenge, then, is to prove that there is an anthropogenic component. I argue that because global warming is “unequivocal” and ‘very likely’ caused by human activities, the reverse should now be the case. The task, then, could be to prove there is no anthropogenic component to a particular observed change in climate, although a more useful task is to determine what it is. In Bayesian statistics, this change might be thought of as adding a ‘prior’. The benefit of doubt and uncertainties about observations and models are then switched. Moreover, the science community is much too conservative on this issue and too many authors make what are called ‘Type II errors’ whereby they erroneously accept the null hypothesis. Global warming is contributing to a changing incidence of extreme weather because the environment in which all storms form has changed from human activities. WIREs Clim Change 2011, 2:925–930. doi: 10.1002/wcc.142

This article is categorized under:

Paleoclimates and Current Trends > Detection and Attribution

Climate Models and Modeling > Knowledge Generation with Models
In defense of the traditional null hypothesis: remarks on the Trenberth and Curry WIREs opinion articles
Authors: Allen Myles
Published: November 2011

In response to their respective opinion articles, I argue that Kevin Trenberth's proposal to reverse the burden of proof in attribution studies is misguided, but Judith Curry's counter proposal to abandon hypothesis tests as useless is worse still. Some observed weather events will have been made more likely by human influence on climate, some less likely, and it is a legitimate and very important field of scientific enquiry to work out which are which. The appropriate null hypothesis to use in such studies is that human influence has not increased the probability of occurrence of a particular weather event unless the evidence suggests otherwise. WIREs Clim Change 2011, 2:931–934. doi: 10.1002/wcc.145

This article is categorized under:

Paleoclimates and Current Trends > Detection and Attribution

Climate Models and Modeling > Knowledge Generation with Models
Multi‐pulse orbits and chaotic dynamics in an imperfect circular plate
Authors: Huangfu Y. , Chen F.
Published: October 2011

The global bifurcations in mode of an imperfect circular plate are investigated with the case of the 1:1 internal resonance and 1:3 primary resonance. After determining the equations of motion in a suitable form, the energy phase method proposed by Haller and Wiggins is employed to show the existence of the Silnikov‐type multi‐pulse orbits homoclinic to certain invariant sets for the two cases of Hamiltonian and dissipative perturbation. Furthermore, some complex chaos behaviors are revealed for this class of systems.
Clinicopathologic Features and Risk Factors for Extrahepatic Recurrences of Hepatocellular Carcinoma After Curative Resection
Authors: Ochiai Toshiya , Ikoma Hisashi , Okamoto Kazuma , Kokuba Yukihito , Sonoyama Teruhisa , Otsuji Eigo
Published: November 2011

Background

The aim of this study was to clarify the clinicopathologic features of hepatocellular carcinoma (HCC) patients with extrahepatic metastasis after the removal of primary HCC, and the risk factors of extrahepatic recurrence.

Methods

Clinicopathologic data were available for 264 HCC patients who underwent an R0 resection for HCC. Twenty‐six patients who developed extrahepatic recurrence during the follow‐up period (EXT group) were compared with patients who remained free from recurrence for at least 5 years after resection (n = 46) (No R group) or had only intrahepatic recurrences (n = 193) (INT group). We also estimated the risk factors of extrahepatic recurrence and survival in these 26 patients.

Results

There were significant differences in primary tumor size, patient’s age, findings in the noncancerous portion, macroscopic type, ductal invasion, intrahepatic metastasis, hepatic involvement and curability of primary tumor, treatment for recurrent tumor, and prognosis between the EXT group and the other groups. Extrahepatic recurrence was significantly associated with six factors by univariate analyses: age, indocyanine green (ICG) 15‐min retention rate, tumor size, hepatic involvement of primary tumor, type of hepatectomy, and TNM stage, of which tumor size was an independent risk factor. Resection of recurrent tumor was the only independent favorable factor for survival of patients with extrahepatic recurrence.

Conclusions

HCC patients with extrahepatic recurrence had advanced primary tumors and poor prognosis. HCC patients with primary tumors larger than 60 mm were predicted to develop extrahepatic recurrence. Resection of recurrent tumor can improve the prognosis of HCC patients with extrahepatic recurrence.
Lessons for Europe: How Canada Dealt with Its Own Fiscal Crisis
Authors: Milke Mark
Published: November 2011

Europe's debt crisis is by no means unique but quite the contrary: Canada had to face a similar challenge during the 1990s. The way this country dealt with the crisis is often presented as a success story. What are the lessons that Europe can learn from Canada's experience? This article examines the similarities between both crises, explains the main reforms Canada went through and finally analyses the key factors that influenced and enabled this country to overcome the crisis.
Utility of Renal Mass Biopsy in a UK Tertiary Referral Centre
Authors: Walton Thomas J. , Amery Carolyn , Moore David , Mayer Nicholas J. , Rajesh Arumugam , Kockelbergh Roger C.
Published: November 2011

Objective:

To determine the value of percutaneous biopsy in a UK cohort of patients with renal mass lesions, with particular reference to its utility for the prediction of histological cell-type, Fuhrman nuclear grade and necrosis.

Patients and methods:

From May 1999 to September 2009, 71 patients underwent renal mass biopsy (RMB), most for indeterminate renal masses or in those with a mass lesion and extrarenal malignancy. Approximately one-third were for small renal masses (≤4cm). Biopsy results were correlated with final surgical specimen pathology or with the outcome of surveillance in those not receiving surgery.

Results:

Of 71 biopsies, there were 65 (91.5%) considered diagnostic biopsies, of which 59 (90.8%) were malignant and 6 (9.2%) were benign. 30 patients with biopsy-proven malignancy underwent extirpative surgery, with a diagnostic accuracy for biopsy of 100%. Accuracy of RMB for histological sub-type, Fuhrman nuclear grade and tumour necrosis was 80.0%, 52.3% and 80.0%, respectively. Bleeding complications were seen in 2 (2.8%) patients, and there were no cases of needle track seeding.

Conclusion:

RMB is a safe and accurate method for determining underlying malignancy, with an acceptable non-diagnostic rate. Although concordance for histological tumour sub-type and necrosis was reasonable, values for nuclear grade were less reliable.
NAD(H)‐coupled hydrogen cycling – structure–function relationships of bidirectional [NiFe] hydrogenases
Authors: Horch M. , Lauterbach L. , Lenz O. , Hildebrandt P. , Zebger I.
Published: November 2011

Hydrogenases catalyze the activation or production of molecular hydrogen. Due to their potential importance for future biotechnological applications, these enzymes have been in the focus of intense research for the past decades. Bidirectional [NiFe] hydrogenases are of particular interest as they couple the reversible cleavage of hydrogen to the redox conversion of NAD(H). In this account, we review the current state of knowledge about mechanistic aspects and structural determinants of these complex multi‐cofactor enzymes. Special emphasis is laid on the oxygen‐tolerant NAD(H)‐linked bidirectional [NiFe] hydrogenase from Ralstonia eutropha.
Coupled azimuthal modes propagating in current-carrying plasma waveguides
Authors: GIRKA V. , GIRKA I. , PAVLENKO I. , GIRKA O. , GIRKA A.
Published: November 2011

The paper is devoted to the theory of electromagnetic surface waves propagating along the azimuthal direction in cylindrical metal waveguides, which are filled with current-carrying plasmas. The problem is solved by the method of successive approximation. Adequacy of this method application is proved here. To study the coupling of ordinary (O-) and extraordinary (X-) azimuthal modes, the linear theory of the eigenazimuthal X- and O-modes is applied as zero approximation. Plasma particles are described in the framework of magneto-hydrodynamics, electromagnetic fields of the coupled azimuthal modes are determined from Maxwell equations. Spatial distribution of electromagnetic field of these coupled modes and their damping caused for different reasons are studied. Possibility to observe experimentally the phenomena, which accompany propagation of these coupled modes, is estimated numerically. Branches of their possible utilization are discussed as well.
Discriminating among similar deep-seaYoldiella(Pelecypoda: Protobranchia) species with a morphometric approach
Authors: Benaim Natalia Pereira , Absalão Ricardo Silva
Published: November 2011

Eight species ofYoldiella(Yoldiella biguttataAllen, Sanders & Hannah, 1995;Yoldiella similisAllen, Sanders & Hannah, 1995;Yoldiella extensaAllen, Sanders & Hannah, 1995;Yoldiellaaff.jeffreysi(Hidalgo, 1877);Yoldiellasp.1;Yoldiellasp. 2;Yoldiellasp. 3 andYoldiellasp. 4) from the continental slope off Rio de Janeiro were used to test if quantitative morphometric measurements of shell shape and hinge plate could effectively discriminate among them. Thirty specimens of each species were sampled, and a total of 25 variables were established and utilized as input data to perform a discriminant analysis. The percentage of correctly classified cases was never less than 80%. The hinge plate variables were always relevant, and the most important one was the width of the posterior hinge plate. On the other hand, shell shape variables, when present, were secondary. Considering that the variation in the shell ofYoldiellaspecies is subtle, and also the findings of this study, we can state that the hinge plate morphometry has good potential to improve species discrimination.
Does size matter? The effects of body size and declining oxygen tension on oxygen uptake in gastropods
Authors: Marsden Islay D. , Shumway Sandra E. , Padilla Dianna K.
Published: November 2011

Metabolic rate is one of the most frequently measured physiological variables and the relationship between oxygen uptake and body mass is one of the most controversial issues in biology. The present study used closed chamber respirometry to compare the oxygen uptake of 32 species of benthic British gastropod molluscs of a wide size-range (from less than 0.001 g to greater than 10 g dry tissue weight). We investigated the effects of body size on the respiratory rate at 10°C to explore the evolutionary and phylogenetically determined patterns of metabolic scaling both among different gastropods groups, and within siphonate and asiphonate caenogastropods. Resting oxygen uptake (O2) increased with body mass (W) with a slope value of 0.6 using both ordinary least squares (OLS) and standard major axis (SMA) where N = 488, over a 6 fold range of body mass. The slopesbof the regression lines relating oxygen uptake to body mass were similar for all heterobranch molluscs and most caenogastropods. Highest mass-specific rates for oxygen consumption were found for the smallest littorinid species. Trophic mode significantly affected the amount of oxygen consumed with higher oxygen uptake in herbivores than other groups, including detritivores and predators. All of the gastropods reduced their oxygen consumption when exposed to declining oxygen conditions; however, about a third of the species exhibited partial regulation at higher oxygen partial pressures. When exposed to 20% normal saturation levels, smaller gastropods respired at approximately 25% of their rates in fully saturated seawater whereas larger species (above 0.1 g dry tissue weight) respired at approximately 35% of the values recorded at full saturation. Our study suggests that a scaling exponent relating O2to body mass of 0.6 is typical and may be ‘universal’ for gastropods. It is below the 0.75 scaling exponent which has been proposed for ectothermic invertebrates. It is concluded that size does matter in determining the metabolic patterns of gastropods and that the quantity of oxygen consumed and the energy balance of gastropods is affected by activity, food type and exposure to declining oxygen conditions.
Chants Democratic in Wisconsin
Authors: Goldberg Chad Alan
Published: October 2011

When I moved to Madison in 2001 to take a job as an assistant professor at the University of Wisconsin, I knew embarrassingly little about my newly adopted state's historical significance. Judging from their wisecracks about the sociology of cows, neither did my friends in New York. I soon learned about Wisconsin's prominent role in many of America's social advances, from “Fighting Bob” LaFollette's opposition to powerful railroad trusts, to pioneering contributions to social insurance, to the nation's first law for public-employee bargaining in 1959, to the turbulent campus protests against the Vietnam War in the 1960s. Little did I know that a decade after my arrival, Wisconsin would once again become “ground zero,” as some commentators now call it, in America's ongoing struggle between democratic progress and reaction.
Observations of the Earth's magnetic field made in Edinburgh from 1670 to the present day
Authors: Barraclough D. R.
Published: November 2011

Magnetic observations made at the same site give valuable information about the time changes (the secular variation) of the geomagnetic field. This paper gives details of all known measurements of the geomagnetic field in and around Edinburgh since the earliest observation of magnetic declination (the difference between true and magnetic north) by George Sinclair in 1670. Early observations of the strength of the field were only relative measurements. Approximate conversion factors are derived to enable these data to be expressed in modern absolute units (nanoteslas). Observed values of declination, inclination and the horizontal intensity of the geomagnetic field are plotted and compared with values computed from mathematical models of the field covering the interval 1690 to 1990, inclusive. The earlier observations were not corrected for the effects of the rapidly varying magnetic fields caused by electric currents in the upper atmosphere. The consequences of this are estimated.
Late Pleistocene environments in lower Strathspey, Scotland
Authors: Hall Adrian M. , Whittington Graeme , Duller Geoffrey A. T. , Jarvis Jack
Published: November 2011

Sedimentary sequences in lower Strathspey provide a record of Late Pleistocene interglacial and glacial environments. After deposition of till and glacifiuvial sediments, probably in Oxygen Isotope Stage 6, a soil developed at Teindland and Redburn which contains downward translocated pollen. This indicates that the earliest vegetation was woodland with grassland openings, Pinus-Alnus at Teindland and Alnus-Corylus at Red Burn. Podzolisation of the soil ended with an influx of sands derived from erosion of the surrounding slopes, at Teindland perhaps a response to extensive burning during a grassland phase. The combined pollen and sedimentary evidence suggests events at the close of an interglacial. Luminescence dates of 79 ± 6 and 67 ± 5 ka for the sands over the soil suggest that the soil developed in Oxygen Isotope Stage 5e. Overlying the soil and sands at Teindland are glacigenic debris flows, perhaps reflecting glaciation during Oxygen Isotope Stage 4. Three, undated, younger till units, with interbedded gravels, also occur in the surrounding area and provide evidence of the complex glacial history of lower Strathspey since Oxygen Isotope Stage 5.
A new Early Cambrian onychophoran-like animal, Paucipodia gen. nov., from the Chengjiang fauna, China
Authors: Jun-yuan Chen , Gui-qing Zhou , Ramsköld Lars
Published: November 2011

An onychophoran-like fossil animal, Paucipodia inermis gen. et sp. nov., is described from the Lower Cambrian Chengjiang lagerstatte in Yunnan, China. The animal was soft-bodied, and possessed six pairs of unjointed legs, each having two claws distally. The body was finely annulated, lacked trunk plates, and apparently terminated posteriorly with the last leg pair, without preserved evidence of a posterior trunk extension. Paucipodia widens the morphological range hitherto known in Cambrian lobopodians, notably regarding leg number and presence or absence of plates. Its morphology also provides support for the recently suggested anteroposterior orientation of Hallucigenia and Microdictyon.
Function of the ice streams in the Scandinavian ice sheet: analyses of glacial geological data from southwestern Finland
Authors: Punkari Mikko
Published: November 2011

Mapping of striae trends, macro-scale erosion forms, drumlins, morainic ridges, eskers, till fabric and boulder fans has facilitated reconstruction of glacial dynamics in terms of ice streams, marginal ice lobes and interlobate zones. Data were recorded in a computerised geographical information system (GIS).

Data on oriented glaciogenic elements are compared with the evolving patterns of glacial flow. The oldest flow occurred at a distance of several hundred kilometres inside the ice margin, while the later flows were dependent on the dynamics of the ice streams and fan-shaped ice lobes. A model is developed for the zonation of subglacial processes such as erosion, deposition and till deformation beneath the ice sheet. Most of the glacial forms, as well as lower till, were generated in a zone of basal melting and fast ice flow which existed some hundred kilometres from the receding margin and was associated with the formation of ice streams. These results are consistent with recent reconstructions of basal hydrology using mathematical models.

Ice streams were important for deglaciation dynamics. In the course of deglaciation, decreased shear stress on the water-saturated substratum resulted in ice-bed uncoupling which lowered the profile and accelerated flow in the ice streams. This did not happen in interstream areas as reflected by the glacial geomorphology typical of inactive ice.
The geochemical stratigraphy, field relations and temporal variation of the Mull–Morvern Tertiary lava succession, NW Scotland
Authors: Kerr Andrew Craig
Published: November 2011

The early Tertiary Mull-Morvern lava succession, NW Scotland, represents the thickest continuous section (1000 m from sea level to the top of Ben More) of Tertiary lavas exposed in the UK. This succession has been sampled and geochemically analysed, on a flow-by-flow basis, throughout the lava succession. Field observations during the course of this sampling suggest that the early lava flows (the Staffa Magma sub-Type) ponded in palaeovalleys along with interlava sediments. In the main part of the Mull lava succession (the Mull Plateau Group) the lava flows are on average ∼ 5 m thick. Most previous Hebridean workers have assumed that the red horizons commonly found between these later lava flows, represent weathered flow tops. However, this study has shown that in some places these red ‘boles’ appear to be a combination of both volcanic ash and weathered basalt.

Chemically distinctive units of flows have been found throughout the succession. The two most abundant magma sub-types of the Mull Plateau Group, primitive (>9wt% MgO) basalts with Ba/Nb» 15 and more evolved (<9wt% MgO) basalts-hawaiites with Ba/Nb<15, form packets of flow units which can be up to 200 m thick. These chemically distinctive flow units have been correlated across the lava succession. However, the correlation of individual lava flows has proved difficult. The Mull Plateau Group lavas generally become more evolved and less contaminated with continental crust towards the top of the succession, culminating in the trachytes of the Pale Group on Ben More. Basaltic lavas above the Pale Group have markedly different trace element ratios, and seem to represent shallower, more extensive asthenospheric melting than the Mull Plateau Group.
Lithostratigraphy of the Ordovician rocks in the Southern Uplands: Crawford Group, Moffat Shale Group, Leadhills Supergroup
Authors: Floyd J. D.
Published: November 2011

A formal lithostratigraphy is erected for all the Ordovician rocks in the Southern Uplands of Scotland. At the base of the succession, the Crawford Group (Arenig–Llanvirn) encompasses the chert and lava sequences usually associated with the tract-bounding faults, and includes the only proven Arenig rocks in the Southern Uplands. The overlying Moffat Shale Group (Caradoc–Llandovery) is now restricted to the black and grey graptolitic shales which succeed the grey and red chert successions. The Leadhills Supergroup (Caradoc–Ashgill) forms the overwhelming bulk of the sedimentary succession and includes the thick Ordovician turbidite successions of the Northern Belt. Existing stratigraphical terminology is reviewed, revised or extended as appropriate to maintain maximum continuity with current usage. Type sections for each unit are either proposed, where newly defined or revised, or cited in the case of existing definitions.
The tuning fork graptoloid, Didymograptus murchisoni (Beck, 1839)
Authors: Rickards R. B. , Khashogji M. S.
Published: November 2011

The development of D. (Didymograptus) murchisoni (Beck), the type species of the genus, is shown to be unequivocally of anus type, with thl1 dicalyal and a low metasicular origin of thl1. An evolutionary line from the early, Arenig, bifidus group is supported; and clear distinctions are drawn between the subgenera D. (Didymograptus), D. (Didymograptellus) and D. (Jenkinsograptus), the first of these being redefined. The range of variation of biocharacters of D. murchisoni is analysed using exquisitely preserved undeformed material from Saudi Arabia, and comparisons are made with the undeformed type material, and with undeformed (nodule) collections from Abereiddy Bay, Pembrokeshire. The astogenetically late developments of D. murchisoni are described.
A new vascular plant from the Lower Devonian Windyfield chert, Rhynie, NE Scotland
Authors: Powell Clare L. , Edwards Dianne , Trewin Nigel H.
Published: November 2011

Two plants are described from fragmentary remains preserved in the Windyfield chert, situated c. 600 m from the classic Rhynie chert locality. Both are sometimes coated by a microbial film. The larger, fertile axes are placed in the new genus and species Ventarura lyonii. They possess a distinctive, sclerenchymatous middle cortex and terete xylem, and marginally dehiscent, lateral sporangia. The new taxon is similar to the Rhynie zosterophyll Trichopherophyton teuchansii, but is placed in a new genus on sporangial differences. Associated smaller axes with unicellular epidermal outgrowths lack the middle cortex of the larger axes and often have medullated protosteles. They are interpreted as subterranean rhizomes and probably belong to the new fertile taxon, but organic continuity between the two has not been demonstrated.