bluuebunny/crossref_metadata_2025_split huggingface dataset:
High‐temperature catalysts for the production of α‐olefins based on iron(II) and iron(III) tridentate bis(imino)pyridine complexes modified by nitrilo group
Authors: Ionkin Alex S. , Marshall William J. , Adelman Douglas J. , Fones Barbara Bobik , Fish Brian M. , Schiffhauer Matthew F. , Soper Paul D. , Waterland Robert L. , Spence Rupert E. , Xie Tuyu 
Published: December 2007

AbstractSeries of Fe(II) and Fe(III) tridentate bis(imino)pyridine complexes without nitrilo groups 2–6 and with nitrilo groups 7–13 were synthesized. According to X‐ray analysis, the introduction of nitrilo groups in para‐ and ortho‐positions tends to result in shorter axial FeN bonds. Both types of complexes, 2–6 and 9–13, afforded very productive catalysts for the production of α‐olefins with higher K values and better linearity of Schultz–Flory distribution α‐olefins than the parent methyl substituted Fe(II) complex 1. Noticeably, the complexes functionalized with a para‐nitrilo group 9–13 tend to make α‐olefins with higher K values of the Schultz–Flory distribution, more ideal distributions, and less of the heavier insoluble fractions of α‐olefins than corresponding nonsymmetrically substituted complexes without para‐nitrilo groups 2–6. Statistically significant correlations were obtained between % solids of total α‐olefins and the blocked solid angle fraction in the +z hemisphere (
$ R_{{\rm adj}}^2 $
= 51.3%, p = 0.012) and between catalyst productivity and total blocked solid angle fraction ($ R_{{\rm adj}}^2 $
= 43.5%, p = 0.023). The modest values of $ R_{{\rm adj}}^2 $
show that, while steric effects are significant, they are not the sole factor determining catalyst performance. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 585–611, 2008
Photocrosslinking in dichromated poly(acrylic acid) during hologram recording and comparison with dichromated poly(vinyl alcohol)
Authors: Barichard Anne , Israëli Yaël , Rivaton Agnès 
Published: December 2007

AbstractPhototransformations involved in dichromated poly(acrylic acid) (DCPAA) were analyzed under irradiation conditions representative of hologram formation. It was shown that, in parallel to the reduction of chromium(VI) into chromium(III), the crosslinking of the matrix occurred through formation of covalent bonds between macromolecular chains. A comparison with dichromated poly(vinyl alcohol) (DCPVA) irradiated under the same conditions was also reported giving evidence for the crucial role played by the chemical structure of the polymeric matrix in the hologram formation. The combined approach based on the fate of both the absorbing species, chromium(VI) and the polymer allowed to completely elucidate the reactions taking place upon irradiation. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 636–642, 2008
Crown‐like macrocycle zinc complex derived from β‐diketone ligand for the polymerization of rac‐lactide
Authors: Pang Xuan , Chen Xuesi , Zhuang Xiuli , Jing Xiabin 
Published: December 2007

AbstractEnolic Schiff base zinc (II) complex 1 was synthesized. XRD revealed 1 was a novel crown‐like macrocycle structure consisted of hexanuclear units of (LZnEt)6 via the coordination chelation between the Zn atom and adjacent amine nitrogen atom. Further reaction of 1 with one equivalent 2‐propanol at RT produced Zn‐alkoxide 2 by in situ alcoholysis. Complex 2 was used as an initiator to polymerize rac‐lactide in a controlled manner to give heterotactic enriched polylactide. Factors that influenced the polymerization such as the polymerization time and the temperature as well as the monomer concentration were discussed in detail in this paper. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 643–649, 2008
Synthesis of poly(ester amide)s with lateral groups from a bulk polycondensation reaction with formation of sodium chloride salts
Authors: Vera Montserrat , Franco Lourdes , Puiggalí Jordi 
Published: December 2007

AbstractPoly(ester amide)s with a regular sequence and derived from diamine, dicarboxylic acid, and glycolic acid units can be easily synthesized by using a thermal polycondensation method based on the formation of metal halide salts as a driving force. These new poly(ester amide)s have tuneable properties depending on the number of methylene groups and constitute a group of materials with potential interest as biodegradable materials in applications such as surgical sutures. The present work reveals that the proposed synthesis can also be applied when esters of L‐lysine are used as a diamine unit since no secondary reactions such as transesterification occur under the required polymerization conditions. The possibility of linking compounds with pharmacological activity to the carboxylic acid groups of lysine extends the interest of the referred materials, for example, as drug delivery systems. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 661–667, 2008
Review of Estimation Models for Biodegradation
Authors: Pavan Manuela , Worth Andrew P. 
Published: December 2007

AbstractThis paper reviews the state‐of‐the‐art of in silico methods for estimating the readily biodegradability of organic chemicals, and describes their (potential) applicability in the identification of chemicals that are persistent or very persistent in the environment, such as Persistent Organic Pollutants (POPs). The paper is based on an in‐depth review performed by the European Chemicals Bureau (ECB) of the European Commission's Joint Research Centre in support of the development of technical guidance for the implementation of the Registration, Evaluation, Authorisation of Chemicals (REACH) legislation, and is one of the series of minireviews in this journal. The review covers the most commonly used approaches for estimating the ready biodegradability of organic compounds, such as group contribution approaches, expert systems, probabilistic approaches and hybrid approaches. The main sources of experimental data used to develop the models are also briefly described. The review concludes with an appraisal of the challenges of developing new models and some recommendations are made for further research.
Stability of Minor Lipid Components with Emphasis on Phytosterols During Chemical Interesterification of a Blend of Refined Olive Oil and Palm Stearin
Authors: Azadmard‐Damirchi Sodeif , Dutta Paresh C. 
Published: December 2007

AbstractMinor compounds such as tocopherols and phytosterols in vegetable oils play an important role in their stability and nutritional value. This study monitored the effects of chemical interesterification on the levels of tocopherols, tocotrienols, phytosterols and phytosterol oxidation products (POPs) in an olive oil and palm stearin blend (50/50 w/w). Tocopherols and tocotrienols were dominated by α‐tocopherol (192 ppm) and γ‐tocotrienol (70 ppm) and decreased during interesterification. Among the tocopherols, δ‐tocotrienol had the highest decrease (35%) at 120 °C. During interesterification at 90 and 120 °C, total sterol content in the oil blend (509 ppm) declined slightly, by 3 and 5%, respectively. Phytosterols were esterified at a higher level at 120 °C (7%) than at 90 °C (4%) during this process. Distribution of fatty acids in the esterified sterols followed the fatty acid composition of the oil blend. Total POP content was 4.3 ppm, and remained generally unchanged during interesterification. Among the nine POPs tentatively identified by their mass spectra, 6‐hydroxysitostanol and 6‐hydroxycampestanol dominated in the oil blend and in the interesterified product. The formation pathways of these saturated di‐hydroxyphytosterols have yet to be identified. Although the interesterification process comprised several treatments, there were only minor losses of tocopherols and phytosterols and virtually no increases in the POPs.
Exploration of the acarine fauna on coconut palm in Brazil with emphasis onAceria guerreronis(Acari: Eriophyidae) and its natural enemies
Authors: Lawson-Balagbo L.M. , Gondim M.G.C. , de Moraes G.J. , Hanna R. , Schausberger P. 
Published: December 2007

AbstractCoconut is an important crop in tropical and subtropical regions. Among the mites that infest coconut palms,Aceria guerreronisKeifer is economically the most important. We conducted surveys throughout the coconut growing areas of Brazil. Samples were taken from attached coconuts, leaflets, fallen coconuts and inflorescences of coconut palms in 112 localities aiming to determine the occurrence and the distribution of phytophagous mites, particularlyA. guerreronis, and associated natural enemies.Aceria guerreroniswas the most abundant phytophagous mite followed bySteneotarsonemus concavuscutumLofego & Gondim Jr. andSteneotarsonemus furcatusDe Leon (Tarsonemidae). Infestation byA. guerreroniswas recorded in 87% of the visited localities. About 81% of all predatory mites belonged to the family Phytoseiidae, mainly represented byNeoseiulus paspalivorusDe Leon,Neoseiulus barakiAthias-Henriot andAmblyseius largoensisMuma; 12% were Ascidae, mainlyProctolaelaps bickleyiBram,Proctolaelapssp nov andLasioseius subterraneusChant.Neoseiulus paspalivorusandN. barakiwere the most abundant predators on attached coconuts. Ascidae were predominant on fallen coconuts, whileA. largoensiswas predominant on leaflets; no mites were found on branches of inflorescences. Leaflets harboured higher mite diversity than the attached coconuts. Mite diversity was the highest in the state Pará and on palms surrounded by seasonal forests and Amazonian rain-forests.Neoseiulus paspalivorus,N. barakiandP. bickleyiwere identified as the most promising predators ofA. guerreronis. Analyses of the influence of climatic factors revealed that dry ambient conditions favour the establishment ofA. guerreronis. Neoseiulus paspalivorusandN. barakihave differing climatic requirements; the former being more abundant in warm and dry areas, the latter prevailing in moderately tempered and humid areas. We discuss the significance of our findings for natural and biological control ofA. guerreronis.
Patterns of acoustic variation inCicada barbaraStål (Hemiptera, Cicadoidea) from the Iberian Peninsula and Morocco
Authors: Pinto-Juma G.A. , Seabra S.G. , Quartau J.A. 
Published: December 2007

AbstractField recordings of the calling song and of an amplitude modulated signal produced by males ofCicada barbarafrom North Africa and the Iberian Peninsula were analysed in order to assess the geographical acoustic variation and the potential usefulness of acoustic data in the discrimination of subspecies and populations. Sound recordings were digitized and the frequency and temporal properties of the calls of each cicada were analysed. In all regions studied, peak frequency, quartiles 25, 50 and 75% and syllable rate showed low coefficients of variation suggesting inherent static properties. All frequency variables were correlated with the latitude, decreasing from south to north. In addition, most acoustic variables of the calling song showed significant differences between regions, and PCA and DFA analyses supported a partitioning within this species between Iberian Peninsula+Ceuta and Morocco, corroborating mtDNA data on the same species. Therefore, the subspecific division ofC. barbaraintoC. barbara barbarafrom Morocco andC. barbara lusitanicafrom Portugal, Spain and Ceuta finds support from the present acoustic analyses, a result which is also reinforced by molecular markers.
Revolutionaries' cemeteries in Berlin: memory, history, place and space
Authors: STANGL PAUL 
Published: December 2007

ABSTRACTIn Germany, the Revolutions of 1848 and 1918/19 resulted in the martyrdom of opposition leaders and constituents, whose burial sites in Berlin became key sites of memory and commemoration for the working-class movement. Political turbulence and regime change throughout the twentieth century has resulted in contestation over the meaning and use of these places; a trajectory illustrating the dynamic, reciprocal relationship between popular memory and official history, and the interplay between representation, place-based associations and spatial relations in constituting social meaning in the urban landscape.
Micro-history of a house: memory and place in a Milanese neighbourhood, 1890–2000
Authors: FOOT JOHN 
Published: December 2007

ABSTRACTThe micro-history of one apartment block in the inner-suburb of Bovisa, Milan over a period of 100 or so years is examined using oral history interviews to trace the development of the block and its residents in relation to that of the city of Milan. The piece is bounded by theoretical reflections on the role of micro-history, oral history and other methodologies as tools for understanding the home and urban history, and concludes that the survival of a rural past, the role of gender, the importance of architecture and of nostalgic memory in a rapidly changing world were important influences.
Dietary intake and development of a quantitative food-frequency
questionnaire for a lifestyle intervention to reduce the risk of chronic
diseases in Canadian First Nations in north-western Ontario
Authors: Sharma Sangita , Cao Xia , Gittelsohn Joel , Ho Lara S , Ford Elizabeth , Rosecrans Amanda , Harris Stewart , Hanley Anthony JG , Zinman Bernard 
Published: December 2007

AbstractObjectivesTo characterise the diet of First Nations in north-western Ontario, highlight
foods for a lifestyle intervention and develop a quantitative food-frequency
questionnaire (QFFQ).DesignCross-sectional survey using single 24 h dietary recalls.SettingEight remote and semi-remote First Nations reserves in north-western
Ontario.Subjects129 First Nations (Oji-Cree and Ojibway) men and women aged between 18 and 80
years.ResultsThe greatest contributors to energy were breads, pasta dishes and chips
(contributing over 20 % to total energy intake). ‘Added
fats’ such as butter and margarine added to breads and vegetables
made up the single largest source of total fat intake (8·4 %).
The largest contributors to sugar were sugar itself, soda and other
sweetened beverages (contributing over 45 % combined). The mean number of
servings consumed of fruits, vegetables and dairy products were much lower
than recommended. The mean daily meat intake was more than twice that
recommended. A 119-item QFFQ was developed including seven bread items, five
soups or stews, 24 meat- or fish-based dishes, eight rice or pasta dishes,
nine fruits and 14 vegetables. Frequency of consumption was assessed by
eight categories ranging from ‘Never or less than one time in one
month’ to ‘two or more times a day’.ConclusionWe were able to highlight foods for intervention to improve dietary intake
based on the major sources of energy, fat and sugar and the low consumption
of fruit and vegetable items. The QFFQ is being used to evaluate a diet and
lifestyle intervention in First Nations in north-western Ontario.
The power of new experimental techniques in astronomy: zooming in on the black hole in the Center of the Milky Way
Authors: Genzel Reinhard 
Published: December 2007

AbstractIt is becoming ever easier to obtain first class astronomical data by working solely from one's computer terminal, the modern equivalent of the armchair. This wonderful development may tempt us to forget that astronomical discoveries and findings are first and foremost driven by hard-won progress in observational and experimental capabilities. The present article is meant to demonstrate this assertion by reviewing recent developments and future possibilities in studying the Center of the Milky Way, our best case for the existence of a (massive) black hole and a superb laboratory for studying the physical processes in the immediate vicinity of such an enigmatic object.
Keplerian masses for the most massive stars: the very luminous, hydrogen-rich Wolf-Rayet stars
Authors: Moffat Anthony F. J. , Schnurr Olivier , Chené André-Nicolas , Casoli Jules , St-Louis Nicole , Villar-Sbaffi Alfredo 
Published: December 2007

AbstractWe propose that the most massive stars in the local Universe start out on the main sequence being extremely luminous and already exhibiting wind-like emission lines. Such stars can probably be identified as hydrogen-rich WN5-7 stars. Masses are now being determined for these stars using the least model-dependent technique of binary orbits.
Supernova impostors: LBV outbursts from the most massive stars
Authors: Van Dyk Schuyler D. 
Published: December 2007

AbstractSeveral recent luminous events that have been identified initially as supernovae (SNe) are probably not genuine SNe at all. Instead we argue that these events are more likely the outbursts, or super-outbursts, of very massive stars in the luminous blue variable (LBV) phase. At least two of these events are analogous to the Great 1843 Eruption of η Carinae.
A Spitzer-IRS search for the galaxies that re-ionized the Universe
Authors: Lacy Mark , Bunker Andrew J. , Kneib Jean-Paul , Teplitz Harry I. 
Published: December 2007

AbstractWe describe an observation designed to find Hα emission from galaxies at z≃7–12 made using the InfraRed spectrograph (IRS) on the Spitzer Space Telescope.
New constraints on the co-moving star formation rate in the redshift interval 6<z<10
Authors: Ellis Richard S. , Stark Daniel P. , Richard Johan , Bunker Andrew J. , Egami Eiichi E. , Kneib Jean-Paul 
Published: December 2007

AbstractRecent progress in measuring the optical depth of neutral hydrogen in distant quasars and that of electron scattering of microwave background photons suggests that most of the sources responsible for cosmic re-ionisation probably lie in the redshift interval 6 to 10. We present two new observational results which, together, provide valuable constraints on the contribution from star-forming sources in this redshift interval. First, using a large sample of v-band dropouts with unconfused Spitzer-IRAC detections, we determine the integrated stellar mass density at z = 5. This provides a valuable ‘integral constraint’ on past star formation. It seems difficult to reconcile the observed stellar mass at z = 5 with the low abundance of luminous i-z- and J-band dropouts in deep Hubble Space Telescope data. Accordingly, we explore whether less luminous star-forming sources in the redshift interval 6 to 10 might be the dominant cause of cosmic re-ionization. In the second component of our research, we report on the results of two surveys for weak Lymanα emitters and z- and J-band dropouts highly-magnified by foreground lensing clusters. Although some promising z = 8–9 candidates are found, it seems unlikely that low luminosity sources in this redshift interval can dominate cosmic reionization. If our work is substantiated by more extensive and precise surveys, the bulk of the re-ionizing photons may come from yet earlier sources lying at redshifts z>10.
An observational pursuit for Pop III stars in a Lyα emitter at z>6 through He II emission
Authors: Nagao Tohru 
Published: December 2007

AbstractWe report our on-going observational project to search for population III (Pop III) stars in high-z galaxies. We searched Lyα emitters (LAEs) with a large equivalent width (EW), by our new selection technique ‘NB921-depressed i′-dropout selection’. We found eight photometric candidates and spectroscopically identified five LAEs with EW0(Lyα) > 100 Å. We then carried out a very deep near-infrared spectroscopy for a LAE among the above five, to search for the redshifted He iiλ1640 emission from Pop III stars in the galaxy, but obtained only an upper limit.
On the size of H II regions around high-redshift quasars
Authors: Maselli Antonella , Gallerani Simona , Ferrara Andrea , Choudhury T. Roy 
Published: December 2007

AbstractWe investigate the possibility of constraining the ionization state of the Intergalactic Medium (IGM) close to the end of re-ionization (z≈6) by measuring the size of the H II regions in high-z quasars spectra, via a combination of SPH and 3D radiative transfer (RT) simulations and a statistical analysis of mock quasar spectra through the simulated cosmological volume.
Implications for the cosmic re-ionization from the optical afterglow spectrum of GRB050904 at z = 6.3
Authors: Totani Tomonori , Kawai Nobuyuki , Kosugi George , Aoki Kentaro , Yamada Toru , Iye Masanori , Ohta Kouji , Hattori Takashi 
Published: December 2007

AbstractWe discuss the implications for the cosmic re-ionization from the optical afterglow spectrum of GRB050904 at z = 6.3
Tachocline, dynamo and the meridional flow connection
Authors: Rüdiger Günther 
Published: December 2007

AbstractOur model for global circulations in the solar convective zone leads to an equatorial drift at its base with an amplitude of about 7 m/s. Its penetration into the solar tachocline is too weak to play any role in the solar dynamo. It confines, however, the internal magnetic decay modes to the radiative core so that the tachocline can be explained as a magnetic Hartmann layer. In the tachocline for the toroidal fields the magnetic Tayler instability exists. We found stability limits for toroidal fields of only 100 G.
Observing SNe Ia at z > 1 with the HST and at z ≃ 0.2 with the SDSS-II
Authors: Lampeitl Hubert , Riess Adam G. 
Published: December 2007

AbstractSNe Ia are currently providing the most direct measurements of the accelerated expansion of the Universe and also put constraints on the nature and evolution of the so-called ‘dark energy’. Despite major efforts to increase the number of known high-redshift SNe Ia with reliable distance estimates, two regions in the Hubble diagram remain only sparsely observed. At redshifts z > 1 the limitations of ground-based instruments require the Hubble Space Telescope and its superior angular resolution to get meaningful distance estimates, while at intermediate redshifts (z ≃ 0.2) the large solid angle necessary presents an obstacle to most surveys that can be overcome with the Sloan Digital Sky Survey, SDSS-II.
Preliminary examination of the comet Wild 2 samples returned by the Stardust spacecraft
Authors: Zolensky Michael E. , Brownlee Donald E. , Tsou Peter , Hörz Friedrich P. , Sandford Scott A. , Flynn George J. , McKeegan Kevin D. , Keller Lindsay P. 
Published: December 2007

AbstractResults of the Stardust mission to sample dust from comet Wild 2 are summarized.
Pre-solar grains in meteorites and interplanetary dust: an overview
Authors: Ott Ulrich , Hoppe Peter 
Published: December 2007

AbstractSmall amounts of pre-solar grains have survived in the matrices of primitive meteorites and interplanetary dust particles. Their detailed study in the laboratory with modern analytical tools provides highly accurate and detailed information with regard to stellar nucleosynthesis and evolution, grain formation in stellar atmospheres, and Galactic Chemical Evolution. Their survival puts constraints on conditions they were exposed to in the interstellar medium and in the Early Solar System.
Pre-solar grains from supernovae and novae
Authors: Amari Sachiko , Lodders Katharina 
Published: December 2007

AbstractPre-solar grains from supernova ejecta – silicon carbide of type X, Si3N4 and low-density graphite – are characterized by Si isotopic anomalies (mainly 28Si excesses), low 14N/15N, high 26Al/27 Al ratios, and occasionally by excesses in 44Ca (from 44Ti decay). Overall isotopic features of these SiC and graphite grains can be explained by mixing of inner Si-rich zones and the outer C-and He-rich zones, but supernova models require fine tuning to account for 14N/15N and 29Si/28Si ratios of the grains. Isotopic ratios of Zr, Mo and Ba in SiC X grains may be explained by a neutron burst model. Some of the pre-solar nanodiamonds require a supernova origin to explain measured xenon isotopic ratios. Only a few nova grain candidates, with low 12C/13C, 14N/15N, and high 26Al/27 Al ratios, have been identified.