bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of high‐molecular weight poly(trimethylene terephthalate) catalyzed by MoO3 supported Al2O3‐TiO2 catalysts
Authors: Liu Jian , Bian Shu‐Guang , Xiao Min , Wang Shuan‐Jin , Meng Yue‐Zhong
Published: November 2009

Poly(trimethylene terephthalate) (PTT) is an excellent fiber materials. Although it was synthesized as early as 1940s, obtaining high‐molecular weight PTT suitable for spinning is not easy due to no evident breakthrough in the catalysts for PTT synthesis. Patents and literatures disclosed a lot of the catalysts of preparing PTT, but which are more or less disadvantageous. Based on acid catalytic mechanism of PTT preparation, a series of solid acid as x% MoO3/(50% Al2O3 − 50% TiO2) (briefly written as xM/(A − T), x = 0, 10, 15, 20 by weight) were prepared by sol–gel coprecipitation and wetting impregnation methods, and first used for PTT synthesis in this work. When 50% Al2O3 − 50% TiO2 (briefly written as A − T) was supported by MoO3 using wetting impregnation technique of (NH4)6Mo7O24.4H2O aqueous solution, a lot of Brφnsted acid and Lewis acid sites were formed on xM/(A − T) catalyst surfaces, which was confirmed by the characteristics of their NH3‐TPD (temperature programmed desorption). All the prepared catalysts were highly active ones toward synthesis of PTT. PTT with high‐intrinsic viscosity (IV) was obtained in the presence of trace amount of the catalysts. IV ranging of the PTT synthesized from 0.66 to 0.95 dL g−1 corresponds to weight average molecular weight
$ (\overline M_w) $
from 49,197 to 73,004. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of iron oxide nanoparticles on the morphological properties of isotactic polypropylene
Authors: Mubarak Yousef Ahmad , Abbadi Fatima O. , Tobgy Ahmed H.
Published: November 2009

Isotactic polypropylene (iPP) and iron oxide (Fe3O4) nanocomposites were mixed by masterbatch blending technique in a single screw extruder machine. The concentrations of Fe3O4 in the iPP/Fe3O4 nanocomposites were 0.5, 1, 2, and 5% by weight. The influence of Fe3O4 nanoparticles on the effectiveness of nucleation, morphology, mode of crystallization, and crystallinity of iPP were studied by differential scanning calorimetry (DSC) and polarized light microscopy (PLM). The introduction of Fe3O4 nanoparticles in the iPP matrix inhibited the formation of β crystals, and caused a shift in the melting point to higher values. The magnitude of the shift was up to 20–21°C which indicates that using the masterbatch technique leads to an enhancement of the dispersion process of the Fe3O4 nanoparticle and the formation of less agglomerates in the iPP/Fe3O4 nanocomposites. The percentage crystallinity, Xc, increased at the low cooling rates of 1 and 2°C/min. At higher cooling rates of 5, 10, and 20°C/min, the masterbatch technique produced nanocomposites of Xc with nonuniform trends. The overall crystallization rate enhancement for the iPP/Fe3O4 nanocomposites is attributed to the presence of Fe3O4 nanoparticles as a nucleating agent which have no significant effect on the growth rate of iPP crystals. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Comparative study of the effect of sulfur on the morphology and rheological properties of SB‐ and SBS‐modified asphalt
Authors: Martínez‐Estrada Abigail , Chávez‐Castellanos A. Enrique , Herrera‐Alonso Margarita , Herrera‐Nájera Rafael
Published: November 2009

The modification of asphalt with styrene‐ butadiene block copolymers and sulfur was studied to elucidate the effect of the molecular characteristics of the polymer, polymer content, and sulfur/polymer ratio on the physical properties of modified asphalts. Two types of styrene‐butadiene copolymers were used (SB and SBS), which differed considerably in terms of their chain architecture, average molecular weights, and size and distribution of their polybutadiene and polystyrene blocks, as shown by gel permeation chromatography, infrared spectroscopy, nuclear magnetic resonance, and differential scanning calorimetry. Sulfur/polymer/asphalt blends were prepared by a hot mixing process and characterized by conventional tests, fluorescence microscopy, and rheology. The results revealed that the morphology of the blends is strongly dependent on polymer concentration and sulfur/polymer ratio. In‐depth rheological characterization showed that the thermomechanical properties changed considerably upon addition of small amounts of sulfur. Collectively, these results suggest that sulfur increases the compatibility between polymer and asphalt by crosslinking polymer chains. Interestingly, the rheological behavior of blends prepared with a combination of SB and sulfur was similar to that exhibited by blends prepared with SBS either in the presence or absence of sulfur. This is explained by assuming that the addition of small amounts of sulfur to SB‐modified asphalt facilitates the formation of an elastomeric network that resembles the one found in SBS‐modified asphalt, effectively contributing to asphalt reinforcement. Nonetheless, the exact dosage of sulfur must be carefully controlled to prevent gel formation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Character of long‐chain branching in highly purified natural rubber
Authors: Amnuaypornsri Sureerut , Tarachiwin Lucksanaporn , Sakdapipanich Jitladda T.
Published: November 2009

The nature of long‐chain branching in natural rubber (NR) from Hevea brasiliensis was analyzed for NR purified by enzymatic deproteinization in the latex state followed by acetone extraction in the solid state to remove the proteins and neutral lipids, respectively. The treatment of purified NR in a toluene solution with a polar solvent, such as methanol or acetic acid, resulted in a clear decrease in the molecular weight, gel content, and Huggins' constant; this was caused by the decomposition of branch points in the purified rubber. This finding clearly showed that long‐chain branching in the purified NR was mainly derived from the association of phospholipids linked with both terminal groups in the rubber chain via hydrogen bonds. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of hyperbranched poly(ester amine) additive on electrospinning of low concentration poly(methyl methacrylate) solutions
Authors: Chen Yi‐Zhang , Peng Pan , Guo Zhao‐Xia , Yu Jian , Zhan Mao‐Sheng
Published: November 2009

Electrospinning of low concentration polymer solutions has the advantage of producing fibers with small diameters, but unfortunately beaded fibers are often observed. This article reports the use of hyperbranched poly(ester amine) (PEA) as an additive for low concentration polymer solutions to eliminate beads and improve the fiber uniformity. Electrospinning of low concentration poly(methyl methacrylate) solutions was investigated. With only 1 wt % hyperbranched PEA, the fiber uniformity was significantly improved. The principle of improvement was investigated by measuring the solution properties, and it is inferred that the improvement is attributed to the significant increase in solution conductivity. The solution viscosity and surface tension only change slightly. The versatility of this approach was demonstrated by electrospinning low concentration solutions of two other polymers: polystyrene and polyoxymethylene. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermal degradation of environmentally friendly phenolic resin/Al2O3 hybrid composite
Authors: Li Chunhua , Qi Shuhua , Zhang Dongna
Published: November 2009

An environmentally friendly phenolic resin/Al2O3 hybrid composite was prepared. Al2O3 particles were pretreated with a silcane coupling agent, then the mixture of paraformaldehyde and treated Al2O3 was grinded with ball crusher for several hours, and added during the phenolic resin polymerization process, finally got the hybrid composite. The kinetic parameters of thermal degradation were calculated by the methods of Kissinger, Flynn‐Wall‐Ozawa and Crane. The thermal degradation activation energy of environmentally friendly phenolic resin/Al2O3 hybrid composite is approximate three times of pure phenolic resin. The results show that the heat resistance is obviously improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Rudimentary Eyes of Squamate Fossorial Reptiles (Amphisbaenia and Serpentes)
Authors: Foureaux Giselle , Egami Mizue Imoto , Jared Carlos , Antoniazzi Marta Maria , Gutierre Robson Campos , Smith Ricardo Luiz
Published: November 2009

The rudimentary characteristic of the eyes of fossorial animals raises some questions regarding its evolution and functionality. Would these eyes result from atrophy or from stagnated development? How would its visual function work? Anatomical investigations of these organs are the fundamental preamble to answer those questions, which are still little explored by the literature. In this article we have studied anatomical aspects of the eyes of three species of fossorial reptiles, within the suborder Amphisbaena (Amphisbaena alba, Amphisbaena mertensi, Leposternon infraorbitale), as well as a species within the ophidian suborder (Typhlops brongersmianus). The minuscule eyes (1–2 mm diameter) were visualized through a scale, a translucent area which corresponds to the spectacle. This spectacle is a thinner and transparent scale, covering a conjunctival sac. The retrobulbar space was filled with the harderian gland. The eyes of Typhlops presented an oval shape, whereas Amphisbaena specimens presented cup‐shaped eyes. In Amphisbaenian sclera is comprised of cartilage, while the thin sclera of Typhlops consists of connective tissue and striated muscle fibers. The retina presented all the typical layers found in vertebrates, regardless the species. The characteristics involved in the fossil adaptation of these species include: reduced size of the eyeball, rudimentary cornea, absence of the anterior chamber, presence of a complex iris‐ciliary body, and lens with amorphous nucleate cells. The analysis of the eye morphology of these animals suggests that there might be a specific function concerning light perception. Anat Rec, 2010. © 2009 Wiley‐Liss, Inc.
Protein Kinase C Activators as Synaptogenic and Memory Therapeutics
Authors: Sun Miao‐Kun , Alkon Daniel L.
Published: November 2009

The last decade has witnessed a rapid progress in understanding of the molecular cascades that may underlie memory and memory disorders. Among the critical players, activity of protein kinase C (PKC) isoforms is essential for many types of learning and memory and their dysfunction, and is critical in memory disorders. PKC inhibition and functional deficits lead to an impairment of various types of learning and memory, consistent with the observations that neurotoxic amyloid inhibits PKC activity and that transgenic animal models with PKCβ deficit exhibit impaired capacity in cognition. In addition, PKC isozymes play a regulatory role in amyloid production and accumulation. Restoration of the impaired PKC signal pathway pharmacologically results in an enhanced memory capacity and synaptic remodeling / repair and synaptogenesis, and, therefore, represents a potentially important strategy for the treatment of memory disorders, including Alzheimer's dementia. The PKC activators, especially those that are isozyme‐specific, are a new class of drug candidates that may be developed as future memory therapeutics.
Contrast in usage of FCAT‐approved anatomical terminology between members of two anatomy associations in North America
Authors: Martin Bradford D. , Thorpe Donna , Merenda Victoria , Finch Brian , Anderson‐Smith Wendy , Consiglio‐Lahti Zane
Published: November 2009

Almost 12 years since the publishing of Terminologia Anatomica (TA) by the Federative Committee on Anatomical Terminology (FCAT), there has yet to be a unified adoption of FCAT‐recommended anatomical terms by North American anatomists. A survey was sent to members of the Human Anatomy & Physiology Society (HAPS) to compare the frequency of FCAT term usage with a previous study involving the American Association of Anatomists (AAA). The HAPS differed from AAA in being composed mostly of biologists (56.5%) who teach anatomy with only 18.3% of respondents having terminal degrees in anatomy. The survey included the same 25 sets of synonymic names for selected gross anatomical structures or related terms used for the AAA survey. Overall results indicate that the FCAT preferred term had the highest frequency of usage in only 40.0% of the survey questions, demonstrating 4% lower compliance than AAA respondents. Compliance with FCAT preferred terms ranged from 92.2% to 1.7% usage. When compared with AAA anatomists, there were reversals in predominant usage between FCAT and non‐FCAT terms for six sets of anatomical structures: HAPS respondents predominantly used non‐FCAT terms for adrenal gland (88.7%), antecubital fossa (57.4%), patellar tendon (65.2%), ligamentum capitis femoris (36.5%), while preferring the FCAT anterior circumflex humeral artery (45.2%) and anterior/posterior preferred over ventral/dorsal (41.7%). Almost 54% of HAPS anatomists were not familiar with the FCAT, nearly 21% higher than the AAA. Anat Sci Educ 3:25–32, 2010. © 2009 American Association of Anatomists.
An index to measure a scientist's specific impact
Authors: De Visscher Alex
Published: November 2009

The specific impact index, or s‐index, is introduced as a measure of a scientist's projected impact per paper. The index is complementary to other indices that measure overall impact as it can distinguish between authors maximizing the quantity of their output and authors maximizing the quality of their output. It also can be used to monitor career progress. The main advantage of the new index is that it reduces age bias from older papers that have more time to accumulate citations than do more recent papers. The index was tested on 24 scientists in different fields and of different statures. The overall projected impact estimated from the index correlates well with Hirsch's h‐index squared (r2=0.99). The impact of different aging models was evaluated as well.
Simulations of the formation and evolution of dwarf galaxies
Authors: Valcke S. , De Rijcke S. , Dejonghe H.
Published: November 2009

We present models of the formation and evolution of isolated dwarf galaxies. The models follow the evolution of an initially homogeneous gas cloud collapsing in a pre‐existing dark‐matter halo. These simplified initial conditions are supported by the merger trees of isolated dwarf galaxies extracted from the milli‐Millennium Simulation. An extensive comparison of the models to observations was made. The models' surface brightness profiles are well fitted by Sérsic profiles and the correlations between the models' Sérsic parameters and luminosity agree with the observations. We have also compared model predictions for the half‐light radius Re, central velocity dispersion σc, broad band colour B – V, metallicity [Z/Z⊙] versus luminosity relations and for the location relative to the fundamental plane with the available data. In all cases the models give the correct slope, in most cases we also get the zero‐point right (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ram pressure stripping of disk galaxies in galaxy clusters
Authors: Roediger E.
Published: November 2009

While galaxies move through the intracluster medium of their host cluster, they experience a ram pressure which removes at least a significant part of their interstellar medium. This ram pressure stripping appears to be especially important for spiral galaxies: this scenario is a good candidate to explain the differences observed between cluster spirals in the nearby universe and their field counterparts. Thus, ram pressure stripping of disk galaxies in clusters has been studied intensively during the last decade. I review advances made in this area, concentrating on theoretical work, but continuously comparing to observations (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminosity function of galaxies in rich and poor galaxy clusters
Authors: Krywult J.
Published: November 2009

Using photometric data from SDSS survey we study the galaxy luminosity function in the 75 rich and poor Abell clusters. The integrated Schechter functions were fitted to unbinned data in the four g, r, i, and z photometric passbands. We find that the luminosity function differs with Abell richness class (R). In all bands the faint‐end slope α is steeper in poor clusters than in rich clusters. Moreover, the value of characteristic magnitude M * decreasing with richness class R (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Metal enrichment of the intracluster medium: SN‐driven galactic winds
Authors: Baumgartner V. , Breitschwerdt D.
Published: November 2009

We investigate the role of supernova (SN)‐driven galactic winds in the chemical enrichment of the intracluster medium (ICM). Such outflows on galactic scales have their origin in huge star forming regions and expel metal enriched material out ofthe galaxies into their surroundings as observed, for example, in the nearby starburst galaxy NGC 253. As massive stars in OB‐associations explode sequentially, shock waves are driven into the interstellar medium (ISM) of a galaxy and merge, forming a superbubble (SB). These SBs expand in a direction perpendicular to the disk plane following the density gradient of the ISM. We use the 2D analytical approximation by Kompaneets (1960) to model the expansion of SBs in an exponentially stratified ISM. This is modified in order to describe the sequence of SN‐explosions as a time‐dependent process taking into account the main‐sequence life‐time of the SN‐progenitors and using an initial mass function to get the number of massive stars per mass interval. The evolution of the bubble in space and time is calculated analytically, from which the onset of Rayleigh‐Taylor instabilities in the shell can be determined. In its further evolution, the shell will break up and high‐metallicity gas will be ejected into the halo ofthe galaxy and even into the ICM. We derive the number of stars needed for blow‐out depending on the scale height and density ofthe ambient medium, as well as the fraction of alpha‐ and iron peak elements contained in the hot gas. Finally, the amount of metals injected by Milky Way‐type galaxies to the ICM is calculated confirming the importance ofthis enrichment process (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High relative velocity central dumbbells in poor clusters
Authors: Quintana H. , Proust D. , Hertling G. , Ramírez A. , Toledo I. , Way M.J.
Published: November 2009

We propose that some high relative velocity dumbbell galaxies are the centers of poor clusters or groups that are coming into a merging process. The components of these galaxies closely follow the incoming velocity of the merging groups, as revealed by the bimodality of the velocity histograms. Only mergers in a direction with a small angle to the line of sight can show the large velocity difference of the components and the velocity separation of incoming subgroups in the histograms. In this case the simple interpretation would be that the dumbbells components are also in an early phase of their merger, as they still keep the information of the incoming orbits, but analysis of a numerous sample is needed to prove this suggestion (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
ToPoS view of the Perseus cluster
Authors: Ryś S. , Siemieniec‐Oziȩbło G. , Urbanik M. , Soida M. , Kus A.
Published: November 2009

We present the first map of the Perseus Cluster obtained within the Toruń Polarimetric Survey (ToPoS). The maps indicate that there is a large scale polarized radiation located at the periphery of classic radius of this cluster. It seems that an investigation of the magnetic structures we should take into account the contribution from circularly polarized radiation. Few pictures presented here seems to support such a point of view (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The evolution of cluster early‐type galaxies over the past 8 Gyr
Authors: Fritz A. , Jørgensen I. , Schiavon R.P. , Chiboucas K.
Published: November 2009

We present the Fundamental Plane (FP) of early‐type galaxies in the clusters of galaxies RXJ1415.1+3612 at z = 1.013. This is the first detailed FP investigation of cluster early‐type galaxies at redshift z = 1. The distant cluster galaxies follow a steeper FP relation compared to the local FP. The change in the slope of the FP can be interpreted as a massdependent evolution. To analyse in more detail the galaxy population in high redshift galaxy clusters at 0.8 < z < 1, we combine our sample with a previous detailed spectroscopic study of 38 early‐type galaxies in two distant galaxy clusters, RXJ0152.7–1357 at z = 0.83 and RXJ1226.9+3332 at z = 0.89. For all clusters Gemini/GMOS spectroscopy with high signal‐to‐noise and intermediate‐resolution has been acquired to measure the internal kinematics and stellar populations of the galaxies. From HST/ACS imaging, surface brightness profiles, morphologies and structural parameters were derived for the galaxy sample. The least massive galaxies (M = 2 x 1010 M⊙) in our sample have experienced their most recent major star formation burst at zform ∼ 1.1. For massive galaxies (M > 2 x 1011 M⊙) the bulk of their stellar populations have been formed earlier zform ≳ 1.6. Our results confirm previous findings by Jørgensen et al. This suggests that the less massive galaxies in the distant clusters have much younger stellar populations than their more massive counterparts. One explanation is that low‐mass cluster galaxies have experienced more extended star formation histories with more frequent bursts of star formation with shorter duration compared to the formation history of high‐mass cluster galaxies (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A continuum of structure and stellar content from Virgo cluster earlytype dwarfs to giants?
Authors: Janz J. , Lisker T.
Published: November 2009

Based on the wealth of multiwavelength imaging data from the SDSS, we investigate whether dwarf and giant early‐type galaxies in the Virgo cluster follow a continuum in their structural parameters and their stellar population characteristics. More specifically we study the relation between size and brightness for the galaxies and their color magnitude relation. In both cases, we find noticeable deviations from a simple joint behavior of dwarfs and giants. We discuss these findings in the light of the different formation mechanisms commonly assumed for dwarf and giant early types, thereby taking into account the existence of several distinct early‐type dwarf subclasses. By comparing our results to a semianalytic model of galaxy formation, we argue that the analyzed relations might be reproduced by processes that form dwarfs and giants altogether. The work presented here is based on Janz & Lisker (2008, 2009) (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The evolution of cluster dwarfs
Authors: Harsono D. , De Propris R.
Published: November 2009

We summarize the results from analyzing six clusters of galaxies at 0.14 < z < 0.40 observed with the Hubble Space Telescope Advanced Camera for Surveys. We derive deep composite luminosity functions in B, g, V, r, i, and z down to absolute magnitude of ∼ –14 + 5 log h mag. The luminosity functions are fitted by a single Schechter function with MBgVriz * = –19.8, –20.9, –21.9, –22.0, –21.7, and –22.3 mag, and α ∼ –1.3 for all bands. The data suggests red sequence dominates the luminosity function down to ≥6 mag below L*, the dwarf spheroidals regime. Hence, at least at z 0.3, the red sequence is well established and galaxies down to dwarf spheroidals are assembled within these clusters. We do not detect the faint‐end upturn (M > –16) that is observed in lower redshift clusters. If this is real, the faint‐end population has originated since z = 0.3 (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Post‐starburst galaxies and the transformation of blue into red galaxies
Authors: De Rijcke S. , Buyle P. , Pisano D.J. , Freeman K. , Dejonghe H.
Published: November 2009

We present deep single‐dish radio observations of a sample of nearby post‐starburst galaxies (0.05 < z < 0.1). About 50% of these post‐starburst galaxies are detected at 21 cm, with HI masses of ∼109 M⊙, up to ∼1010 M⊙. These post‐starburst galaxies are as gas‐rich as spiral galaxies with comparable luminosities. There appears to exist no direct correlation between the amount of H I present in a post‐starburst galaxy and its star formation rate as traced by radio continuum emission. Moreover, the end of the starburst clearly does not necessarily require the complete exhaustion of the neutral gas reservoir. High‐resolution radio observations of one post‐starburst binary system suggest that most of the neutral gas resides outside the stellar bodies of the galaxies. Most likely, the gas was expelled by supernova and/or AGN feedback. This effectively stops star formation, even though copious amounts of diffuse neutral gas remain in the immediate vicinity. This remaining H I reservoir may eventually lead to further episodes of star formation. This may indicate that some post‐starbursts are observed in the inactive phase ofthe star formation duty cycle (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stellar populations of seven early‐type dwarf galaxies and their nuclei
Authors: Paudel S. , Lisker T.
Published: November 2009

Dwarf galaxies are the numerically dominating population in the dense regions of the universe. Although they seem to be simple systems at first view, the stellar populations of dwarf elliptical galaxies (dEs) might be fairly complex. Nucleated dEs are of particular interest, since a number of objects exhibit different stellar populations in their nuclei and host galaxy. We present stellar population parameters obtained from integrated optical spectra using a Lick index analysis of seven nucleated dwarf elliptical galaxies and their nuclei. After subtracting the scaled galaxy spectra from the nucleus spectra, we compared them with one another and explore their stellar populations. As a preliminary result, we find that the luminosity weighted ages of the nuclei slightly lower than those of galaxies, however, we do not see any significant difference in metallicity of the host galaxies and their nuclei (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The properties of fossil groups of galaxies
Authors: Eigenthaler P. , Zeilinger W.W.
Published: November 2009

Numerical simulations as well as optical and X‐ray observations over the last few years have shown that poor groups of galaxies can evolve to what is called a fossil group. Dynamical friction as the driving process leads to the coalescence of individual galaxies in ordinary poor groups leaving behind nothing more than a central, massive elliptical galaxy supposed to contain the merger history of the whole group. Due to merging timescales for less‐massive galaxies and gas cooling timescales of the X‐ray intragroup medium exceeding a Hubble time, a surrounding faint‐galaxy population having survived this galactic cannibalism as well as an extended X‐ray halo similar to that found in ordinary groups, is expected. Recent studies suggest that fossil groups are very abundant and could be the progenitors of brightest cluster galaxies (BCGs) in the centers of rich galaxy clusters. However, only a few objects are known to the literature. This article aims to summarize the results of observational fossil group research over the last few years and presents ongoing work by the authors. Complementary to previous research, the SDSS and RASS surveys have been cross‐correlated to identify new fossil structures yielding 34 newly detected fossil group candidates. Observations with ISIS at the 4.2 m William Herschel Telescope on La Palma have been carried out to study the stellar populations of the central ellipticals of 6 fossil groups. In addition multi‐object spectroscopy with VLTs VIMOS has been performed to study the shape of the OLF of one fossil system (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dwarf spheroidal galaxies in the M81 group of galaxies
Authors: Lianou S. , Grebel E.K. , Koch A.
Published: November 2009

We study the properties of the dwarf galaxy population in the nearby interacting M81 group of galaxies. In particular, we are deriving the metallicity distribution functions, the ages and the star formation histories of these dwarf galaxies based on data from the Hubble Space Telescope's Advanced Camera for Surveys and the Sloan Digital Sky Survey. We are correlating this information with the dwarf galaxies' position in the group in order to derive the impact of interactions and environment on their evolution. Here we present preliminary results on the metallicity distribution functions of dwarf spheroidals in the M81 group (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Testing of the dwarf galaxy content and the evolutionary status of nearby groups of galaxies
Authors: Vennik J. , Hopp U.
Published: November 2009

We carried out visual and parametric searches for dwarf galaxies in five loose groups of galaxies. Follow‐up spectroscopy with the HET has shown a 50% success rate of morphological selection. The evolutionary status of the studied groups differs: while the NGC 6962 group has a partially relaxed core, surrounded by an infall region, the NGC 5005/5033 group and the IC 65 group, which consist only of late‐type galaxies, are probably still assembling (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Evolution of dwarf galaxies in the Centaurus A group
Authors: Crnojević D. , Grebel E.K. , Koch A.
Published: November 2009

The study of (dwarf) galaxies in nearby groups is one among the most powerful tools that can be used to investigate galaxy evolution, chemical enrichment and environmental effects on these objects. The Centaurus A group (at a distance of ∼4 Mpc) is dynamically evolved and contains about 30 dwarf companions of different morphologies and stellar contents. Here we present the first results for the dwarf spheroidal galaxy population in this group. We use archival HST/ACS data to study their resolved stellar content. The resulting metallicity distribution functions reveal metal‐poor populations and wide metallicity spreads for each galaxy. We find no clear trend of the derived physical properties as a function of galaxy position in the group. Finally, we compare our results to the dwarf population of the Local Group, and find no outstanding differences (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Galaxy‐galaxy interactions as triggers of star formation
Authors: Popescu N.A.
Published: November 2009

Galaxy‐galaxy interactions represent the main physical processes that trigger substantial star formation in galaxies. In order to study the galaxy interactions effects on color and morphology of the galaxies in the fields of two radio galaxies at z ∼ 1, we combined optical‐NIR photometry and HST/WFPC2 morphology data from the Stanford et al. (2002) catalog, with HST/WFPC2 archival images. Using a strong pair isolation criterion in terms of the apparent angular separation and rest‐frame line‐of‐sight velocity difference, we obtained a sample of galaxy pairs in the studied fields. The fact that close interactions and mergers induce star‐forming episodes is confirmed by the presence of morphological disturbances and bluer optical‐NIR colors at many analyzed galaxies (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A study of major mergers using a multi‐phase ISM code
Authors: Weniger J. , Theis Ch. , Harfst S.
Published: November 2009

Galaxy interactions are a common phenomenon in clusters of galaxies. Especially major mergers are of particular importance, because they can change the morphological type of galaxies. They have an impact on the mass function of galaxies and they trigger star formation – the main driver of the Galactic Matter Cycle. Therefore, we conducted a study of major mergers by means of a multi‐phase ISM code. This code is based on a TREE‐SPH‐code combined with a sticky particle method allowing for star formation controlled by the properties of a multi‐phase ISM. This is in contrast to the usually implemented Schmidt law depending mainly on the gas density. Previously, this code was used on isolated galaxies. Since our star formation recipe is not restricted to a special type of galaxy, it is interesting to apply it to interacting galaxies, too. Our study on major mergers includes a research of global properties of the interacting system, namely the star formation rate and the star formation efficiency, the evaporation and condensation rates, as well as the mass exchange of distinct components, namely stars, diffuse ISM, and clouds. Investigating these properties provides insight to interrelations between various physical processes. The results indicate that the star formation efficiency as well as the evaporation and condensation rates are influenced by the interaction (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
IC 1370: A merger candidate at the periphery of a z ∼ 0.05 cluster
Authors: Temporin S. , Ciroi S.
Published: November 2009

Recent studies show evidence of galaxy pre‐processing within groups and/or filaments before infall in galaxy clusters. We present VIMOS/IFU observations of IC1370, a galaxy that shows morphological signatures of a recent merger and is located at a projected distance of ∼1.2 Mpc to the center of the cluster II Zw108 at z ∼ 0.05. This galaxy shows two opposite tidal tails, a boxy bulge with a de Vaucouleurs light profile, and a disk component that contributes ∼50 % of the total luminosity. We investigate the history of the galaxy by applying the spectral synthesis technique to the integral field observations and combining the resulting information with morphological and photometric parameters. The same observations allow us to investigate a background (z ∼ 0.09) compact group of 6 galaxies, ofwhich IC 1370 was initially thought to be the central, brightest member (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The evolution of spheroidal galaxies in different environments
Authors: Fritz A. , Ziegler B.L.
Published: November 2009

We analyse the kinematic and chemical evolution of 203 distant spheroidal (elliptical and S0) galaxies at 0.2 < z < 0.8 which are located in different environments (rich clusters, low‐mass clusters and in the field). VLT/FORS and CAHA/MOSCA spectra with intermediate‐resolution have been acquired to measure the internal kinematics and stellar populations of the galaxies. From HST/ACS and WFPC2 imaging, surface brightness profiles and structural parameters were derived for half of the galaxy sample. The scaling relations of the Faber‐Jackson relation and Kormendy relation as well as the Fundamental Plane indicate a moderate evolution for the whole galaxy population in each density regime. In all environments, S0 galaxies show a faster evolution than elliptical galaxies. For the cluster galaxies a slight radial dependence of the evolution out to one virial radius is found. Dividing the samples with respect to their mass, a mass dependent evolution with a stronger evolution of lower‐mass galaxies (M < 2 × 1011 M⊙) is detected. Evidence for recent star formation is provided by blue colours and weak [OII] emission or strong Hδ absorption features in the spectra. The results are consistent with a down‐sizing formation scenario which is independent from the environment of the galaxies (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Flat galaxies in the SDSS DR6
Authors: Kautsch S.J.
Published: November 2009

This study presents the fractions of different spiral galaxy types from a complete and homogeneous sample of 15 127 edge‐on disk galaxies extracted from the sixth data release from the Sloan Digital Sky Survey. The sample is divided in broad morphological classes and sub types consisting of galaxies with bulges, intermediate types and galaxies which appear bulgeless. A small fraction of disky irregulars is also detected. The morphological separation is based on automated classification criteria which resemble the bulge sizes and the flatness of the disks. Each of these broad classes contains about 1/3 of the total sample. Using strict criteria for selecting pure bulgeless galaxies leads to a fraction of 15 % of simple disk galaxies (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The evolution of the gas content of galaxy groups
Authors: Wilcots E.M.
Published: November 2009

We examine multiple facets of the evolution of the gas content of galaxy groups. Complementing building evidence that a tremendous amount of galaxy transformation takes place in the group environment we find evidence of similar transformation of the gas content. In dynamically young groups galaxy‐galaxy interactions appear to be responsible for depositing large quantities of neutral gas into the intergalactic medium. The gas content of dynamically evolved groups, however, is characterized by extended halos of diffuse hot gas. We also find that groups may harbor significant quantities of heretofore undetected baryons and that feedback from AGN may be responsible for heating the intragroup medium (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Energetic coupling between clustered lesions modulated by intervening triplet repeat bulge loops: Allosteric implications for DNA repair and triplet repeat expansion
Authors: Völker Jens , Plum G. Eric , Klump Horst H. , Breslauer Kenneth J.
Published: November 2009

Clusters of closely spaced oxidative DNA lesions present challenges to the cellular repair machinery. When located in opposing strands, base excision repair (BER) of such lesions can lead to double strand DNA breaks (DSB). Activation of BER and DSB repair pathways has been implicated in inducing enhanced expansion of triplet repeat sequences. We show here that energy coupling between distal lesions (8oxodG and/or abasic sites) in opposing DNA strands can be modulated by a triplet repeat bulge loop located between the lesion sites. We find this modulation to be dependent on the identity of the lesions (8oxodG vs. abasic site) and the positions of the lesions (upstream vs. downstream) relative to the intervening bulge loop domain. We discuss how such bulge loop‐mediated lesion crosstalk might influence repair processes, while favoring DNA expansion, the genotype of triplet repeat diseases. © 2009 Wiley Periodicals, Inc. Biopolymers 93: 355–369, 2010.

This article was originally published online as an acceptedpreprint. The “Published Online” date corresponds to the preprint version. You can reqest a copy of the preprint byemailing the Biopolymers editorial office at biopolymers@wiley.com
Determination of the absolute configurations at stereogenic centers in the presence of axial chirality
Authors: Polavarapu Prasad L. , Jeirath Neha , Kurtán Tibor , Pescitelli Gennaro , Krohn Karsten
Published: November 2009

Cephalochromin, a homodimeric naphthpyranone natural product, contains both axial chirality due to the hindered rotation along the biaryl axis and central chirality due to the C‐2, C‐2′ stereogenic centers of the fused pyranone ring. For determining the absolute configurations (ACs) of central chirality elements, different chiroptical spectroscopic methods, namely vibrational circular dichroism (VCD), electronic circular dichroism (ECD), and optical rotation (OR), have been used. From these experimental data, in conjunction with corresponding quantum chemical predictions at B3LYP/6‐311G* level, it is found that the ECD spectra of cephalochromin are dominated by its axial chirality and are not suitable to distinguish the (aS,2S,2′S) and (aS,2R,2′R) diastereomers and hence to determine the ACs of the central chirality elements. OR signs also did not distinguish the (aS,2S,2′S) and (aS,2R,2′R) diastereomers. On other hand, VCD spectrum of cephalochromin exhibited separate spectral features attributable to axial chirality and stereogenic centers, thereby allowing the determination of both types of chirality elements. This is the first investigation demonstrating that, because of vibrations specific to the studied stereogenic centers, VCD spectroscopy can be used to simultaneously determine the ACs of axial and central chirality elements whenever other chiroptical methods (ECD and OR) fail to report on them. Chirality 21:E202–E207, 2009. © 2009 Wiley‐Liss, Inc.
Protein phosphatase 2A subunit gene haplotypes and proliferative breast disease modify breast cancer risk
Authors: Dupont William D. , Breyer Joan P. , Bradley Kevin M. , Schuyler Peggy A. , Plummer W. Dale , Sanders Melinda E. , Page David L. , Smith Jeffrey R.
Published: November 2009

BACKGROUND:

Protein phosphatase 2A (PP2A) is a major cellular phosphatase and plays key regulatory roles in growth, differentiation, and apoptosis. Women who are diagnosed with benign proliferative breast disease are at increased risk for the subsequent development of breast cancer.

METHODS:

The authors evaluated genetic variation of PP2A holoenzyme subunits for their potential contribution to breast cancer risk. A nested case‐control investigation was performed on a cohort of women who had a history of benign breast disease. The women were followed for an average of 18 years, and DNA prepared from the original archival benign breast biopsy (1954‐1995) was available for 450 women who were diagnosed with breast cancer on follow‐up and for 890 of 900 women in a control group who were matched on race, age, and year of entry biopsy.

RESULTS:

Single allele‐based and haplotype‐based tests of association were conducted with assessment of significance by permutation testing. Significant risk and protective haplotypes of the PP2A structural/regulatory subunit A α isoform (PPP2R1A) were identified and had odds ratios of 1.63 (95% confidence interval [CI], 1.3‐2.1) and 0.55 (95% CI, 0.41‐0.76), respectively. These odds ratios remained significant after the analysis was adjusted for multiple comparisons. Women who had both the PPP2R1A risk haplotype and a history of proliferative breast disease had an odds ratio of 2.44 (95% CI, 1.7‐3.5) for the subsequent development of breast cancer. The effects of haplotypes for 2 PP2A regulatory subunit genes, PP2 regulatory subunit B α isoform (PPP2R2A) and PP2A regulatory subunit B′ ϵ isoform (PPP2R5E) on breast cancer risk were nominally significant but did not remain significant after the analysis was adjusted for multiple comparisons.

CONCLUSIONS:

The current findings supported the previously hypothesized role of PP2A as a tumor suppressor gene in breast cancer. Cancer 2010. © 2010 American Cancer Society.
Bendamustine is effective therapy in patients with rituximab‐refractory, indolent B‐cell non‐Hodgkin lymphoma
Authors: Kahl Brad S. , Bartlett Nancy L. , Leonard John P. , Chen Ling , Ganjoo Kristen , Williams Michael E. , Czuczman Myron S. , Robinson K. Sue , Joyce Robin , van der Jagt Richard H. , Cheson Bruce D.
Published: November 2009

BACKGROUND:

Bendamustine hydrochloride is a novel alkylating agent. In this multicenter study, the authors evaluated the efficacy and toxicity of single‐agent bendamustine in patients with rituximab‐refractory, indolent B‐cell lymphoma.

METHODS:

Eligible patients (N = 100, ages 31‐84 years) received bendamustine at a dose of 120 mg/m2 by intravenous infusion on Days 1 and 2 every 21 days for 6 to 8 cycles. Histologies included follicular (62%), small lymphocytic (21%), and marginal zone (16%) lymphomas. Patients had received a median of 2 previous regimens (range, 0‐6 previous regimens), and 36%were refractory to their most recent chemotherapy regimen. Primary endpoints included overall response rate (ORR) and duration of response (DOR). Secondary endpoints were safety and progression‐free survival (PFS).

RESULTS:

An ORR of 75% (a 14% complete response rate, a 3% unconfirmed complete response rate, and a 58% partial response rate) was observed. The median DOR was 9.2 months, and median PFS was 9.3 months. Six deaths were considered to be possibly treatment related. Grade 3 or 4 (determined using National Cancer Institute Common Toxicity Criteria [version 3.0.19]. reversible hematologic toxicities included neutropenia (61%), thrombocytopenia (25%), and anemia (10%). The most frequent nonhematologic adverse events (any grade) included nausea (77%), infection (69%), fatigue (64%), diarrhea (42%), vomiting (40%), pyrexia (36%), constipation (31%), and anorexia (24%).

CONCLUSIONS:

Single‐agent bendamustine produced a high rate of objective responses with acceptable toxicity in patients with recurrent, rituximab‐refractory indolent B‐cell lymphoma. Cancer 2010. © 2010 American Cancer Society.
Flow immunocytochemistry of marker expression in cells from body cavity fluids
Authors: Krishan Awtar , Ganjei‐Azar Parvin , Hamelik Ronald , Sharma Deepti , Reis Isildinha , Nadji Mehrdad
Published: November 2009

Diagnostic cytology based on the examination of cells from body cavity fluids misses ∼50% of patients with a proven malignancy. In an earlier study, we used immunohistochemical detection of epithelial membrane antigen expression with flow cytometric detection of DNA aneuploidy to reduce the number of false negatives. In the present study, we have combined DNA flow cytometry with flow cytometric detection of marker expression to analyze cells from body cavity fluids. Seventy‐nine specimens of ascites and pleural fluids were analyzed by diagnostic cytology, DNA flow cytometry, and for the expression of the following markers: Ber‐EP4, progesterone (PR), MUC4, and thyroid transcription factor‐1 (TTF‐1). DNA index of equal to or greater than 1.2 was seen in 33/79 (41.7%) of the samples. Statistical analysis of 79 samples in which data from cytology, DNA aneuploidy, and expression of at least one of the markers was available showed that by combining data from positive marker expression with that of aneuploidy, the sensitivity was increased from 58.5 to 100%. In contrast, out of the 38 samples designated as non‐malignant by diagnostic cytology, nine had aneuploid DNA content and 16 of the diploid samples had a positive marker expression. Specificity was reduced from 74.7 to 31.6% due to the presence of aneuploidy and marker expression in these samples. ALDH1pos/CD44pos/CD24neg expression has been reported to be associated with human breast tumor stem cells. Some of our samples had cells with this phenotype. Flow cytometry offers the advantage of rapid multiparametric analysis of DNA aneuploidy and marker expression in cells from body cavity fluids based on the analysis of a large number of cells without observer bias. By further developing the use of specific markers and aneuploidy, it may be possible to refine flow cytometric analysis for rapid detection of malignant cells in body cavity fluids. © 2009 International Society for Advancement of Cytometry
Normal table of postembryonic zebrafish development: Staging by externally visible anatomy of the living fish
Authors: Parichy David M. , Elizondo Michael R. , Mills Margaret G. , Gordon Tiffany N. , Engeszer Raymond E.
Published: November 2009

The zebrafish is a premier model organism yet lacks a system for assigning postembryonic fish to developmental stages. To provide such a staging series, we describe postembryonic changes in several traits that are visible under brightfield illumination or through vital staining and epiflourescent illumination. These include the swim bladder, median and pelvic fins, pigment pattern, scale formation, larval fin fold, and skeleton. We further identify milestones for placing postembryonic fish into discrete stages. We relate these milestones to changes in size and age and show that size is a better indicator of developmental progress than is age. We also examine how relationships between size and developmental progress vary with temperature and density, and we document the effects of histological processing on size. To facilitate postembryonic staging, we provide images of reference individuals that have attained specific developmental milestones and are of defined sizes. Finally, we provide guidelines for reporting stages that provide information on both discrete and continuous changes in growth and development. Developmental Dynamics 238:2975–3015, 2009. © 2009 Wiley‐Liss, Inc.