bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism and Enantioselectivity of [Zinc(diamine)(diol)]‐Catalyzed Asymmetric Hydrosilylation of Ketones: DFT, NMR and ECD Studies
Authors: Gajewy Jadwiga , Gawronski Jacek , Kwit Marcin
Published: November 2012

NMR and ECD measurements together with density functional theory computations were used to analyze the mechanism of [Zn(diamine)(diol)]‐catalyzed ketone hydrosilylation. Of the three possible pathways, the one that assumes formation of a Zn‐hydride species acting as an active catalyst appears energetically most favorable. This conclusion is in contrast to a previously proposed mechanism that assumed the reaction between the [Zn(diamine)(diol)] catalyst, the silane, and the substrate, took place through Zn‐activation of the carbonyl group. The absolute stereochemistry of the final product predicted on the basis of our proposal is in agreement with the available experimental data. It appears that the most important factor that controls stereochemistry of the whole process is preorganization of the reaction substrates by formation of a NH···O=C hydrogen bond between the catalyst and the substrate.
Comparative analysis of salt‐responsive phosphoproteins in maize leaves using Ti4+‐IMAC enrichment and ESI‐Q‐TOFMS
Authors: Hu Yufeng , Guo Shuangxi , Li Xuexian , Ren Xueqin
Published: November 2012

Salinity is one of the most common abiotic stresses encountered by plants. Reversible protein phosphorylation is involved in plant defense processes against salinity stress. Here, we performed global phosphopeptide mapping through enrichment by our synthesized PVA‐phosphate‐Ti4+ IMAC coupled with subsequent identification by ESI‐Q‐TOF MS. A total of 104 peptide sequences containing 139 phosphorylation sites were determined from 70 phosphoproteins of the control leaves. In contrast, 124 phosphopeptides containing 143 phosphorylated sites from 92 phosphoproteins were identified in salt‐stressed maize leaves. Compared with the control, 47 proteins were phosphorylated, 25 were dephosphorylated, and 45 overlapped. Among the 72 differential phosphoproteins, 35 were known salt stress response proteins and the rest had not been reported in the literature. To dissect the differential phosphorylation, gene ontology annotations were retrieved for the differential phosphoproteins. The results revealed that cell signaling pathway members such as calmodulin and 14‐3‐3 proteins were regulated in response to 24‐h salt stress. Multiple putative salt‐responsive phosphoproteins seem to be involved in the regulation of photosynthesis‐related processes. These results may help to understand the salt‐inducible phosphorylation processes of maize leaves.
Correlations between the dielectric properties and exterior morphology of cells revealed by dielectrophoretic field‐flow fractionation
Authors: Gascoyne Peter R. C. , Shim Sangjo , Noshari Jamileh , Becker Frederick F. , Stemke‐Hale Katherine
Published: November 2012

Although dielectrophoresis (DEP) has great potential for addressing clinical cell isolation problems based on cell dielectric differences, a biological basis for predicting the DEP behavior of cells has been lacking. Here, the dielectric properties of the NCI‐60 panel of tumor cell types have been measured by dielectrophoretic (DEP) field‐flow fractionation, correlated with the exterior morphologies of the cells during growth, and compared with the dielectric and morphological characteristics of the subpopulations of peripheral blood. In agreement with earlier findings, cell total capacitance varied with both cell size and plasma membrane folding and the dielectric properties of the NCI‐60 cell types in suspension reflected the plasma membrane area and volume of the cells at their growth sites. Therefore, the behavior of cells in DEP‐based manipulations is largely determined by their exterior morphological characteristics prior to release into suspension. As a consequence, DEP is able to discriminate between cells of similar size having different morphological origins, offering a significant advantage over size‐based filtering for isolating circulating tumor cells, for example. The findings provide a framework for anticipating cell dielectric behavior on the basis of structure–function relationships and suggest that DEP should be widely applicable as a surface marker‐independent method for sorting cells.
Biosorption of cadmium(II) from aqueous solution by chitosan encapsulated Zygosaccharomyces rouxii
Authors: Jiang Wei , Xu Ying , Li Chunsheng , Lv Xin , Wang Dongfeng
Published: November 2012

A new type of biosorbent—chitosan encapsulated Zygosaccharomyces rouxii (CZ) was used to remove Cd(II) from aqueous solution. The CZ with Z. rouxii biomass to chitosan of 4:10 (weight ratio) had high removal percentage of Cd(II) and regular spherical shape. Pseudo‐second‐order kinetic model (R2 > 0.9980) and Freundlich adsorption isotherm model (R2 = 0.9913) were suitable to describe the biosorption process. Effects of contact time, initial pH, initial Cd(II) concentration, and biosorbent dose on Cd(II) adsorption capacity of CZ were studied. CZ had a good performance when the initial pH ranged from 3.0 to 7.0 and could remove 95.15% Cd(II) from aqueous solution with suitable biosorbent dose (15 g L−1) when the initial Cd(II) concentration was 0.2 mmol L−1. Protein and nucleic acid leaching from CZ were greatly reduced compared with Z. rouxii biomass at different pH levels. In addition, five biosorption/desorption/regeneration cycles were proceeded to investigate the reusability of CZ. Laser particle size analyzer, scanning electron microscopy, and energy dispersive spectrometry and pHPZC were used to characterize CZ. This work suggested that CZ has good potential to remove Cd(II) from aqueous solution. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 1101–1110, 2013
Synthesis and evaluation of antibacterial polyurethane coatings made from soybean oil functionalized with dimethylphenylammonium iodide and hydroxyl groups
Authors: Bakhshi Hadi , Yeganeh Hamid , Mehdipour‐Ataei Shahram
Published: November 2012

Preparation of antibacterial polyurethane coatings from novel functional soybean oil was considered in this work. First, epoxidized soybean oil (ESBO) as a low price and widely available renewable resource raw material was subjected to the reaction with aniline using an ionic liquid as a green catalyst. The intermediate phenylamine containing polyol (SAP) was then methylated by reaction with methyl iodide to produce a polyol (QAP) with pendant dimethylphenylammonium iodide groups. To regulate the physical and mechanical properties as well as biological characteristics of final coatings, QAP was mixed with different portions of a similar soybean oil‐based polyol (MSP) without quaternary ammonium groups. The mixtures were reacted with isophorone diisocyanate to produce crosslinked polyurethane coatings. Evaluation of viscoelastic properties by DMA method revealed single phase structure with Tg in the range of 50–82°C. Stress–strain analysis of the prepared polyurethanes showed initial modulus, tensile strength, and elongation at break in the ranges of 13–299 MPa, 4.5–13.8 MPa, and 16–109%, respectively. Additionally, the coatings showed good adherence to aluminum and PVC substrates. The solvent extracted samples showed excellent biocompatibility as determined by monitoring L929 fibroblast cells morphology and MTT assay. Meanwhile, very promising antibacterial properties against both Gram‐positive (S. aureus) and Gram‐negative (E. coli) bacteria with bacterial reduction in the range of 83–100% was observed. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
High biocompatibility and improved osteogenic potential of novel Ca–P/titania composite scaffolds designed for regeneration of load‐bearing segmental bone defects
Authors: Cunha Carla , Sprio Simone , Panseri Silvia , Dapporto Massimiliano , Marcacci Maurilio , Tampieri Anna
Published: November 2012

Regeneration of load‐bearing bone segments is still an open challenge due to the lack of biomaterials mimicking natural bone with a suitable chemicophysical and mechanical performance. This study proposes ceramic bone scaffolds made of β‐tricalcium phosphate (β‐TCP) and titania (TiO2), developed from hydroxyapatite (HA) and TiO2 starting nanopowders, which exhibit high and interconnected macroporosity (>70 vol %). The scaffold composition was designed to achieve a synergistic effect of bioactivity/resorbability and mechanical properties suitable for load‐bearing regenerative applications. The analysis of the morphology, structure, and mechanical strength of the scaffolds resulted in compression strength nearly twice that of commercially available HA bone grafts with similar structure (Engipore®). Biological characterization was carried out for human MG‐63 osteoblast‐like cells proliferation, activity, attachment, and viability. β‐TCP/TiO2 scaffolds show high proliferation rate, high viability, and high colonization rates. Moreover, an increased activity of the osteogenic marker alkaline phosphatase (ALP) was found. These results demonstrate that β‐TCP/TiO2 scaffolds have good potential as osteogenically active load‐bearing scaffolds; moreover, given the high and interconnected macroporosity as well as the resorbability properties of β‐TCP, these scaffolds may enhance in vivo osteointegration and promote the formation of new organized bone, thus resulting in very promising biomimetic scaffolds for long bone regeneration. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Novel Chromatic Transitions of Azobenzene‐Functionalized Polydiacetylene Aggregates in 1,2‐Dichlorobenzene Solution
Authors: Hu Wenlong , Hao Jiang , Li Jingguo , Zou Gang , Zhang Qijin
Published: November 2012

Herein, we prepare three azobenzene‐functionalized polydiacetylene (PDA) aggregates in 1,2‐dichlorobenzene solution with reversible thermochromic and novel photo‐induced chromatic behavior. The influence of chemical structural variation on the chromatic transition properties of the PDAs aggregates has been explored in detail by in situ FTIR spectroscopic analyses. The links between chromatic transitions and the molecular structure of PDA aggregates has been established. The results demonstrate that suitable head group interactions and alkyl side chain lengths are both essential for the sensitivity and reversibility of the thermochromic and photochromic properties of PDAs aggregates in solution.
Reactive Graphene Oxide Nanosheets: A Versatile Platform for the Fabrication of Graphene Oxide–Biomolecule/Polymer Nanohybrids
Authors: Xu Li Qun , Zhang Bin , Chen Yu , Neoh Koon‐Gee , Kang En‐Tang , Fu Guo Dong
Published: November 2012

Graphene oxide (GO) nanosheets can be functionalized with reactive pentafluorophenyl ester via esterification of the carboxylic groups. The resulting reactive GO nanosheets provide a versatile platform for grafting of amino‐containing polymers or biomolecules via ester–amine coupling. Coupling of poly[(9,9‐dioctylfluorene)‐alt‐(4‐amino‐phenylcarbazole)] (PFCz‐NH2), amino‐terminated hyperbranched polyglycerol (HPG‐NH2), and lysozyme (Lyz) was illustrated. The Al/GO‐g‐PFCz/ITO sandwich thin‐film device exhibits bistable electrical switching and rewritable memory effects. The GO‐g‐Lyz nanohybrids exhibit high bactericidal efficacy against S. aureus and E. coli, while the GO‐g‐HPG nanohybrids exhibit reduced cytotoxicity toward 3T3 fibroblasts.
Effect of ethylenediamine on corrosion of AISI 4130 steel alloy in 30% ethylene glycol solution under static and hydrodynamic condition
Authors: Danaee I. , Niknejad Khomami M.
Published: November 2012

The electrochemical behavior of steel alloy in 30% ethylene glycol‐water solution at different solution rotating speeds was investigated by polarization curves and AC impedance measurements. The results obtained showed that corrosion rate was not changed significantly in different rotating speed. The effect of ethylenediamine as inhibitor was studied and high inhibition efficiency was obtained. It was found that inhibitor adsorption was occurred in presence of inhibitor. The inhibiting effect of the ethylenediamine was explained on the basis of the competitive adsorption between the inhibitor and the aggressive Cl– ions and the adsorption isotherm basically obeys the Langmuir adsorption isotherm. Thermodynamic parameters for inhibitor adsorption were determined and reveal that the adsorption process is spontaneous.
Three new xanthone derivatives from an algicolous isolate of Aspergillus wentii
Authors: Sun Ran‐Ran , Miao Feng‐Ping , Zhang Jing , Wang Gang , Yin Xiu‐Li , Ji Nai‐Yun
Published: November 2012

Three new xanthone derivatives, yicathin A (1), yicathin B (2), and yicathin C (3), and three known anthraquinone derivatives, alatinone (4), 1,5‐dihydroxy‐3‐methoxy‐7‐methylanthraquinone (5), and 5‐hydroxy‐1,3‐dimethoxy‐7‐methylanthraquinone (6), were isolated from the cultures of Aspergillus wentii pt‐1, an endophytic fungus isolated from the marine red alga Gymnogongrus flabelliformis. Their structures were unambiguously elucidated by NMR and mass spectroscopic methods as well as quantum chemical calculations. Compound 2 was active against Escherichia coli, and 3 could inhibit E. coli, Staphylococcus aureus, and Colletotrichum lagenarium. Copyright © 2012 John Wiley & Sons, Ltd.
The role of polycarbonate molecular weight in the poly(L‐lactide) blends compatibilized with poly(butylene succinate‐co‐L‐lactate)
Authors: Wang Y. , Chiao S.M. , Lai M.‐T. , Yang S.‐Y.
Published: November 2012

Poly(butylene succinate‐co‐L‐lactate) (PBSL)–compatibilized poly(L‐lactide) (PLLA) polymer blends with two commercial grades of polycarbonate (PC) were investigated. The capillary tests showed that the steady shear viscosity of high molecular weight PC (PC‐L) was 10 times higher than that of low molecular weight PC (PC‐AD) throughout the shear rate range under investigation. Morphologic examination revealed that the shape of the dispersed PC‐L phase in the as‐extruded blends was largely spherical, but the PC‐AD phase was more like a rod and elongated further during injection molding. Notched Izod impact strength (IS) of the unmodified PLLA/PC‐L blend was higher than that of PC‐AD blend. The IS of modified ternary blends increased with PBSL content because of enhanced phase interaction indicated from thermal and morphologic analysis. The PBSL modification also enhanced IS more significantly in PLLA/PC‐L than in PLLA/PC‐AD blends. On the contrary, the heat deflection temperature (HDT) of PLLA/PC‐L binary system was much lower than that of PLLA/PC‐AD. HDT of PBSL‐modified PLLA/PC‐AD blends dropped with increasing PBSL content, which is a ductile polymer. Thermal and dynamic mechanical analysis of the ternary blends showed that individual components were immiscible with distinct Tgs for PC and PLLA and distinct Tms for PBSL and PLLA. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Topological insulators and thermoelectric materials
Authors: Müchler Lukas , Casper Frederick , Yan Binghai , Chadov Stanislav , Felser Claudia
Published: November 2012

magnified image

Topological insulators (TIs) are a new quantum state of matter which have gapless surface states inside the bulk energy gap [1–4]. Starting with the discovery of two‐dimensional TIs, the HgTe‐based quantum wells [5, 6], many new topological materials have been theoretically predicted and experimentally observed. Currently known TI materials can possibly be classified into two families [7], the HgTe family and the Bi2Se3 family. The signatures found in the electronic structure of a TI also cause these materials to be excellent thermoelectric materials [8–10]. On the other hand, excellent thermoelectric materials can be also topologically trivial. Here we present a short introduction to topological insulators and thermoelectrics, and give examples of compound classes where both good thermoelectric properties and topological insulators can be found. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Manifold‐based feature point matching for multi‐modal image registration
Authors: Hu Liang , Wang Manning , Song Zhijian
Published: November 2012

Background

Images captured using different modalities usually have significant variations in their intensities, which makes it difficult to reveal their internal structural similarities and achieve accurate registration. Most conventional feature‐based image registration techniques are fast and efficient, but they cannot be used directly for the registration of multi‐modal images because of these intensity variations.

Methods

This paper introduces the theory of manifold learning to transform the original images into mono‐modal modalities, which is a feature‐based method that is applicable to multi‐modal image registration. Subsequently, scale‐invariant feature transform is used to detect highly distinctive local descriptors and matches between corresponding images, and a point‐based registration is executed.

Results

The algorithm was tested with T1‐ and T2‐weighted magnetic resonance (MR) images obtained from BrainWeb. Both qualitative and quantitative evaluations of the method were performed and the results compared with those produced previously. The experiments showed that feature point matching after manifold learning achieved more accurate results than did the similarity measure for multi‐modal image registration.

Conclusions

This study provides a new manifold‐based feature point matching method for multi‐modal medical image registration, especially for MR images. The proposed method performs better than do conventional intensity‐based techniques in terms of its registration accuracy and is suitable for clinical procedures. Copyright © 2012 John Wiley & Sons, Ltd.
Evaluating test‐to‐code traceability recovery methods through controlled experiments
Authors: Qusef Abdallah , Bavota Gabriele , Oliveto Rocco , Lucia Andrea De , Binkley David
Published: November 2012

Recently, different methods and tools have been proposed to automate or semi‐automate test‐to‐code traceability recovery. Among these, Slicing and Coupling based Test to Code trace Hunter (SCOTCH) exploits slicing and conceptual coupling to identify the classes tested by a JUnit test. However, until now the evaluation of test‐to‐code traceability recovery methods has been limited to experiments assessing their tracing accuracy rather than the actual support these methods provide to a software engineer during traceability recovery tasks. Indeed, a research method or tool has a better chance of being transferred to practitioners if it is supported by empirical evidence. In this paper, we present the results of two controlled experiments carried out to evaluate the support given by SCOTCH during traceability recovery, when compared with other traceability recovery methods. The results show that SCOTCH is able to suggest a higher number of correct links with higher accuracy, thus sensibly improving the performances of software engineers during test‐to‐code traceability recovery tasks. Copyright © 2012 John Wiley & Sons, Ltd.
The Use and Misuse of Academic Words in Writing: Analyzing the Writing of Secondary English Learners and Redesignated Learners
Authors: Cons Andrea Marie
Published: November 2012

This study investigated the specific ways secondary English learners (ELs) and redesignated fluent English‐proficient learners (RFEPs) use academic vocabulary that assesses interpretive reading and analytical writing ability. The research examines howELs andRFEPs, formerlyELs, differ in use and misuse of academic words. The study extends Olson's (2007) work by analyzing how secondary students use academic words correctly and incorrectly. The results indicate that although both groups rarely used academic words,RFEPs used significantly more academic words and made fewer academic word errors thanELs. Qualitative analyses reveal thatRFEPs used academic words to add cohesion, details, and precision in their writing to a greater extent thanELs. Findings have three pedagogical implications. First,ELs need more exposure to academic words in writing. Second,ELs need explicit instruction on how to effectively use academic words in writing. Third,ELs need more writing practice in general to become more comfortable with the act of writing so that they will feel more comfortable using more words overall, specifically academic words. Thus, writing should be assigned often. Also, becauseELs andRFEPs used few academic words in their writing, both groups need more exposure to and practice with using academic words in writing.
Apoptosis induced by para‐phenylenediamine involves formation of ROS and activation of p38 and JNK in chang liver cells
Authors: Chye Soi Moi , Tiong Yee Lian , Yip Wai Kien , Koh Rhun Yian , Len Yi Won , Seow Heng Fong , Ng Khuen Yen , Ranjit De Alwis , Chen Ssu Ching
Published: November 2012

para‐phenylenediamine (p‐PD) is a suspected carcinogen, but it has been widely used as a component in permanent hair dyes. In this study, the mechanism of p‐PD‐induced cell death in normal Chang liver cells was investigated. The results demonstrated that p‐PD decreased cell viability in a dose‐dependent manner. Cell death via apoptosis was confirmed by enhanced DNA damage and increased cell number in the sub‐G1 phase of the cell cycle, using Hoechst 33258 dye staining and flow cytometry analysis. Apoptosis via reactive oxygen species generation was detected by the dichlorofluorescin diacetate staining method. Mitogen‐activated protein kinase (MAPK) activation was assessed by western blot analysis and revealed that p‐PD activated not only stress‐activated protein kinase (SAPK)/c‐Jun N‐terminal kinases (JNK) and p38 MAPK but also extracellular signal‐regulated kinase (ERK). Cytotoxicity and apoptosis induced by p‐PD were markedly enhanced by ERK activation and selectively inhibited by ERK inhibitor PD98059, thus indicating a negative role of ERK. In contrast, inhibition of p38 MAPK activity with the p38‐specific inhibitor SB203580 moderately inhibited cytotoxicity and apoptosis induction by p‐PD. Similarly, SP600125, an inhibitor of SAPK/JNK, moderately inhibited cytotoxicity and apoptosis induced by p‐PD, thus implying that p38 MAPK and SAPK/JNK had a partial role in p‐PD‐induced apoptosis. Western blot analysis revealed that p‐PD significantly increased phosphorylation of p38 and SAPK/JNK and decreased phosphorylation of ERK. In conclusion, the results demonstrated that SAPK/JNK and p38 cooperatively participate in apoptosis induced by p‐PD and that a decreased ERK signal contributes to growth inhibition or apoptosis. © 2012 Wiley Periodicals, Inc. Environ Toxicol 29: 981–990, 2014.
Elemental composition of freshwater sponges Drulia uruguayensis and Drulia cristata collected in the Tapajós River
Authors: de Barros Iuri Bezerra , Santos Emily Silva Gomes dos , Gomes Desirée Emelly Dantas , Volkmer‐Ribeiro Cecília , Silva Cláudia Cândida , da Veiga Junior Valdir Florêncio
Published: November 2012

Sponges are aquatic, predominantly marine animals, but are also represented by several families that inhabit freshwater environments. All freshwater sponges are included in the Demospongiae class and so have skeletons composed of silicious spicules. Because they are filter feeders, they have high potential for bioaccumulation of metals, with various implications and applications in environmental chemistry. This study describes the inorganic chemical composition of two Amazonian species of freshwater sponges: Drulla cristata and Drulla uruguayensis, using energy dispersive X‐ray fluorescence. In both species, the major constituent was silicon (36.75% and 36.05%, respectively), followed by aluminum. Elements such as sulfur, chlorine, copper, and titanium were selectively accumulated and were detected only in the species D. cristata, suggesting its use in environmental characterization studies. Copyright © 2012 John Wiley & Sons, Ltd.
Übergänge in die Ausbildung: Welche Rolle spielt die Ausbildungsreife?
Authors: Kohlrausch Bettina , Solga Heike
Published: November 2012

Untersuchungen zeigen, dass der Übergang in eine voll qualifizierende Ausbildung für Hauptschüler/innen zunehmend schwieriger wird. Als Erklärung wird häufig die Annahme formuliert, dass mehr und mehr Hauptschulabgänger/innen die erforderliche Ausbildungsreife fehle, d. h. dass sie (noch) nicht den Anforderungen einer beruflichen Ausbildung gerecht würden. Es existieren keine empirischen Studien darüber, ob sich Hauptschulabgänger/innen mit und ohne Ausbildungsplatz wirklich in ihrer Ausbildungsreife unterscheiden. Dieser Frage wird im vorliegenden Beitrag auf Basis von Längsschnittdaten von niedersächsischen Hauptschulabgänger/innen nach Klasse 9 nachgegangen. Zentrale Ergebnisse der Analysen sind: 45 % dieser Abgänger/innen gelingt direkt nach dem Verlassen der Schule der Übergang in eine voll qualifizierende Ausbildung. Dabei spielen fachliche Leistungen eine geringere Rolle als die Note für das Arbeitsverhalten sowie Unterschiede in der betrieblichen Einbindung der Jugendlichen bereits während der Schulzeit. Die Ergebnisse weisen darauf hin, dass vor allem das Sozialverhalten als eine Dimension von Ausbildungsreife sowie – darüber hinausgehend – Möglichkeiten des Entdeckens von Stärken der Jugendlichen und nicht nur ihrer Schwächen wichtige Faktoren für den Erfolg von Hauptschüler/innen beim Übergang in eine Ausbildung sind.
A semantic approach for QoS specification of communication services using QoE parameters
Authors: Cé Júnior José , Prudêncio Achilles C. , Willrich Roberto , da Silva Madalena P.
Published: November 2012

Various operations related to Quality of Service (QoS) management in communication networks require the clients/users to specify the quality level of the network service. The current QoS proposals adopt a fixed set of performance parameters at the network level to specify quality levels, avoiding dealing with the problem of heterogeneity among QoS parameters and metrics during the service management. However, in several situations where humans are the end-users of the service, the quality level should be specified using Quality of Experience (QoE) parameters, more natural for humans than network performance parameters. On the other hand, the QoS specification using QoE parameters is not sufficient to the service providers; they must translate QoE parameters into network parameters. This paper proposes a semantic approach to the automatic QoE/QoS mapping using the Network QoS Ontology (NetQoSOnt), offering automatic and extensible translation between QoE and QoS parameters. The use of our proposal is illustrated by supporting a voice over IP service negotiation.
Protoliths of Paleoproterozoic calciphyres from the Irkut block (Sharyzhalgai uplift of the Siberian craton): composition and origin
Authors: Urmantseva L.N. , Turkina O.M. , Kapitonov I.N.
Published: November 2012

The paper presents data on high-grade silicate–carbonate rocks (calciphyres) from the Irkut block (Sharyzhalgai uplift, southwestern Siberian craton). Their origin and age were determined from the rock characteristics, U–Pb dating, REE content, and Hf isotope composition of zircon. The calciphyres occur both as independent section fragments and as interbeds within Paleoproterozoic garnet-bearing and high-alumina (cordierite- and sillimanite-bearing) gneisses. They were produced by metamorphism of terrigenous-carbonate sediments. The terrigenous sediments range in maturity from arenites and wackes to argillaceous rocks; this is consistent with the reconstruction of the sedimentary protoliths of paragneisses, which are predominant in the metasedimentary rocks. The petrogeochemical features of the calciphyres, their LREE enrichment relative to “pure” carbonate rocks, and a distinct Eu anomaly were inherited from the terrigenous component of calc-silicate sediments. The Nd model age (2.4–2.7 Ga) of the calciphyres and the value THf(DM-2st) = 2.5–3.0 Ga for zircon from these rocks indicate that carbonate accumulation was accompanied by the supply of terrigenous material, which formed during the erosion of Archean and Paleoproterozoic crust. Zircon from the calciphyres is similar to metamorphic zircon in REE patterns and Th/U ratios. It might have been of detrital origin and then recrystallized during high-temperature metamorphism. Terrigenous-silicate rocks were metamorphosed at ca. 1.87 Ga. This is close to the previous age estimates for the terrigenous rocks metamorphism (1.85–1.86 Ga) and the age of baddeleyite from apocarbonate metasomatic rocks (1.86 Ga).
The 1912 earthquake in South Baikal: traces in bottom sediments and gas release into the water column
Authors: Vologina E.G. , Sturm M. , Radziminovich Ya.B. , Vorob’eva S.S. , Shchetnikov A.A.
Published: November 2012

Large earthquakes took place in southern Cisbaikalia in the first half of 1912. They might have caused a mass release of gas (methane?) into the water column of Lake Baikal and the atmosphere near Sharyzhalgai station of the Circum-Baikal Railroad. This phenomenon was observed in August 1912 by the residents as rising water columns several meters high and reported in the regional press.

To find traces of this event, core was recovered from bottom sediments at a depth of 1300 m in winter 2010. The depth interval 1–8.7 cm is a homogeneous layer, no more than 100 years old (210Pb dating). The sediments here are poor in SiO2biog but richer in Corg than the underlying sediments. Also, they are marked by a considerable content of terrestrial plant remains, a lower content of planktonic diatoms, and higher contents of benthic and ancient diatoms. These data indicate that the layer under study formed as a result of the 1912 earthquake, with a considerable contribution from the littoral and shallow-water zones of Lake Baikal.
Reconstruction of the Holocene climate based on a carbonate sedimentary record from shallow saline Lake Verkhnee Beloe (western Transbaikalia)
Authors: Solotchina E.P. , Sklyarov E.V. , Solotchin P.A. , Vologina E.G. , Stolpovskaya V.N. , Sklyarova O.A. , Ukhova N.N.
Published: November 2012

We present results of mineralogical and crystallochemical studies of the Holocene carbonate sediments of a small saline lake localized in the Borgoi dry-steppe region, western Transbaikalia. Mg-calcites with a varying Mg content are predominant in the assemblage of endogenic carbonate minerals from bottom sediments. Mathematical modeling of the XRD spectra of carbonates permitted us to identify excess-Ca dolomites, which are an indicator of a shallow (playa) lake. The studies showed that the lacustrine Mg-calcites do not form a continuous series from low- to high-Mg varieties. We discuss the cause of this phenomenon and also consider the existing viewpoints of the structure of low-temperature Mg-calcites and excess-Ca dolomites and their formation conditions in lacustrine sediments. Juxtaposing the carbonate record with the data of lithological analysis, determined stable isotopes (δ18O and δ13C), and distribution of some geochemical indicators of climatic changes, we reconstructed the intricate evolution of Lake Verkhnee Beloe, which was controlled by the regional climate since the postglacial period till the present day.
High-molecular heteroatomic components of crude oils of the Timan–Pechora petroliferous basin
Authors: Golovko A.K. , Kam’yanov V.F. , Ogorodnikov V.D.
Published: November 2012

Based on the experimentally measured parameters of elemental composition, average molecular masses, and PRM spectrometry data, we calculated the average structural parameters of resin and asphaltene molecules in Paleozoic crude oil of some oilfields in the Timan–Pechora petroliferous basin. The values of the structural parameters of cyclic and aliphatic fragments in the molecules of resin–asphaltene components of the crudes studied here are within the ranges established earlier for high-molecular compounds of crudes from other petroliferous basins. The average structural-group characteristics of resins in crudes from carbonate reservoirs vary over narrow ranges of values independently of the age and depth of occurrence of the reservoir. The resinous fractions of crudes from terrigenous horizons show symbatic enrichment with paraffin fragments and depletion with naphthene fragments of molecules with depth. This points to the presence of a paragenesis of petroleum hydrocarbons and heteroatomic compounds in the Earth’s interior.
Gender inequality from beyond the grave: intra-household distribution and wellbeing after spousal loss
Authors: HALLERÖD BJÖRN
Published: November 2012

The present article integrates research on spousal loss among older people and research on intra-household income distribution and relates pre-loss intra-household distribution of incomes to post-loss wellbeing. Data are drawn from the Swedish Panel Survey of Ageing and the Elderly (PSAE) and consist of couples that were married in the mid-1990s (N=1,503) and that were either still married (N=1,262) or who had experienced spousal loss (N=241) in 2002–03. The results showed that large intra-household pre-loss income differences increased the occurrence of psycho-social problems among both widows and widowers. Hence, unequal intra-household distribution of resources makes the coping process harder for both men and women. It was also shown that unequal pre-loss distribution of incomes affected a measure of global wellbeing among widowers. Widows suffered to a greater degree from economic difficulties, but these difficulties were not related to pre-loss distribution of incomes. Thus, the overall results showed that a gendered labour market that generates an unequal intra-household distribution of incomes has repercussions not only for gender equality among intact households, but also for the coping process of both widows and widowers.
Making music or gaining grades? Assessment practices in tertiary music ensembles
Authors: Harrison Scott D. , Lebler Don , Carey Gemma , Hitchcock Matt , O'Bryan Jessica
Published: November 2012

Participation in an ensemble is a significant aspect of tertiary music experience. Learning and assessment practices within ensembles have rarely been investigated in Australia and the perceptions of staff and students as to how they learn and are assessed within ensembles remain largely unexplored. This paper reports on part of a larger project that investigated learning and assessment practices within ensembles at an Australian Conservatorium of Music. Ensembles contribute to approximately 25% of student work in each semester, and the assessment contributes to a final grade for the semester. Using a case study methodology, four music ensembles were studied. The data generated were coded into themes including assessment practices and processes; collaborative learning practices; the development of the professional musician; and communication and transparency between participants and the institution. Findings revealed that both staff and student participants in this study perceived ensemble participation to be valuable to the development of a professional musician, but that assessment procedures did not always support this goal. Institutional demands were found to be an inhibiting factor in the assessment of ensembles, and both students and teachers had problems with current assessment procedures, resulting in confusion and lack of transparency about how ensembles are assessed. Approaches to the development of the professional musician became a dominant discussion point and a substantial finding of the research. By examining dominant and subjugated knowledge in this domain, institutional power relations were interrogated, existing practices were challenged, and assessment practices rethought.
Effect of Hurricane Karl on a plant–ant network occurring in coastal Veracruz, Mexico
Authors: Sánchez-Galván Ingrid R. , Díaz-Castelazo Cecilia , Rico-Gray Víctor
Published: November 2012

We analysed the effect of a hurricane on a plant–ant network and on vegetation cover. Plant cover was sampled using linear sampling in several vegetation types: deciduous forest, a dry forest, sand dune pioneers, sand dune scrub, ecotone of freshwater marsh, deciduous forest and dune scrub, and mangrove forest. We sampled ant–plant interactions and vegetation cover before and after Hurricane Karl hitting (September 2010) the central coast of the state of Veracruz, Mexico. The pre-hurricane network consisted of 16 plant and 25 ant species in 52 associations. The post-hurricane network consisted of 17 plant and 20 ant species in 56 associations. We found a significant decrease in the total linear cover of EFN-bearing plants between October 2009 (646 m, no hurricane effect) and October 2010 (393 m, after hurricane Karl) (total sample length 2025 m). Both networks were significantly nested (0.999 and 0.973, P < 0.001), suggesting that network topology remained similar. Our results show changes in several network characteristics and species proportions. The number of plant species that contributed to nestedness vs. idiosyncratic species did not differ significantly in the pre-hurricane network, while the number of plant species that contributed to nestedness vs. idiosyncratic species did differ significantly in the post-hurricane network. The number of ant species that contributed to nestedness vs. idiosyncratic species differed significantly in the pre-hurricane network, and also in the post-hurricane network. Differences in nestedness contributions of species before and after the hurricane reflect an alteration from a generalized, highly nested, more stable pre-disturbance network, to a more low-degree or specialized network (i.e. fewer interactions among generalist species, those species with the most associations). The maintenance of important core components of the network after a huge disturbance, suggests a short-term resilience typical of mutualistic networks.
Remote video-camera traps measure habitat use and competitive exclusion among sympatric chimpanzee, gorilla and elephant in Loango National Park, Gabon
Authors: Head Josephine S. , Robbins Martha M. , Mundry Roger , Makaga Loïc , Boesch Christophe
Published: November 2012

Species commonly exist in sympatry, yet ecological studies are often based on a single species approach while ignoring the impact of sympatric competitors. Over 13 mo we used 24 remote video-camera traps to monitor habitat use of sympatric chimpanzee, gorilla and elephant in four different habitat types in Loango National Park, Gabon. Habitat use by each species was predicted to vary according to seasonal changes in food availability and precipitation. Increased interspecific competition between the three species was expected at times of reduced resource availability, leading to exclusion of the inferior competitor. Supporting the predictions, species abundance per habitat showed seasonal variation: all three species responded positively to increased fruit availability in all habitats, but the response was only significant for gorilla in mature forest and elephant in coastal forest. Responses to rainfall varied, with the chimpanzee responding negatively to rainfall in swamp forest, the gorilla responding positively to rainfall in coastal and secondary forest, and the elephant responding positively to rainfall in mature forest. Elephant presence resulted in competitive exclusion of the apes under certain conditions: the chimpanzee was excluded by the elephant where fruit availability was low, whereas the gorilla was excluded by the elephant in areas of low herb density despite high fruit availability. Our results emphasize the value of applying a multi-species, longer-term approach to studying variation in habitat use among sympatric species and highlight the impact competitors can exert on one another's distribution.
Effects of fire on above-ground forest biomass in the northern Brazilian Amazon
Authors: Martins Flora da Silva Ramos Vieira , Xaud Haron Abrahim Magalhães , dos Santos João Roberto , Galvão Lênio Soares
Published: November 2012

Fires can significantly affect the structure, floristic composition and biomass content of tropical forests, which are not adapted to this disturbance. To assess the impact of understorey fires on above-ground biomass, this study was conducted in the northern Brazilian Amazon (Roraima state), where uncontrolled forest fires are recurrent. Fifty plots (0.25 ha each) distributed across five fire disturbance classes were inventoried. Losses in biomass stocks were significant (−57% and −63%) for forests that suffered from recurrent fires and progressively occurred until some point between 3 and 7 y after the last fire, as deduced from previous studies. Twelve years after a fire event, biomass stocks were reconstituted, although differences in the floristic composition were associated with greater fire severity, particularly driven by the dominance of theCecropiaspp. In thrice-burned forests, live biomass reached levels of secondary forests of the same region. For large trees (> 50 cm dbh), the reduction (−54%) in biomass was significant in thrice-burned areas. These findings highlight the threat that fires represent for tropical rain forests and emphasise the need for long-term surveys in order to distinguish between the effects of fire severity, fire frequency and time-since-fire artefact.
Spermatogenesis inLeptodactylus chaquensis. Histological study
Authors: Villagra Ana Lucrecia Iruzubieta , Cisint Susana Beatriz , Crespo Claudia Alejandra , Medina Marcela Fátima , Ramos Inés , Fernández Silvia Nélida
Published: November 2012

The organization and the histological characteristics ofLeptodactylus chaquensistestis throughout the reproductive cycle were analyzed in the presented study. Gonads of adult males, processed with routine techniques for optical microscopy, revealed that during the reproductive period the seminiferous tubules were characterized by presentation of a large number of cysts, germ cells at the same maturation stage supported by Sertoli cells. All the germ line cells were also present in the postreproductive period and maintained their morphological characteristics. Primary spermatogonia were large-sized cells found isolated or in small groups. The rest of the cells of the germ line formed cysts. Secondary spermatogonia showed morphological characteristics similar to their predecessors, although they were smaller. Primary and secondary spermatocytes showed images of the different stages of the first and second meiotic division respectively. One finding was the presence of intercytoplasmic bridges between the secondary spermatocytes. Primary spermatids were rounded cells with an acrosomal vesicle associated with the nucleus and had cysts that were characterized by large intercellular spaces. Secondary spermatids were elongated cells with a well defined acrosome, which in the spermatozoa had the shape of an arrowhead. Another peculiar characteristic of this species was the fusion of the walls of the seminiferous tubule with the efferent duct that formed a path for spermatozoa during spermiation. The presence in the seminiferous tubules of all stages of the spermatogenic line during the two periods of the cycle studied indicated thatLeptodactylus chaquensishad a potentially continuous reproductive cycle.
Design of a Model to Predict Surge Capacity Bottlenecks for Burn Mass Casualties at a Large Academic Medical Center
Authors: Abir Mahshid , Davis Matthew M. , Sankar Pratap , Wong Andrew C. , Wang Stewart C.
Published: November 2012

Objectives

To design and test a model to predict surge capacity bottlenecks at a large academic medical center in response to a mass-casualty incident (MCI) involving multiple burn victims.

Methods

Using the simulation software ProModel, a model of patient flow and anticipated resource use, according to principles of disaster management, was developed based upon historical data from the University Hospital of the University of Michigan Health System. Model inputs included: (a) age and weight distribution for casualties, and distribution of size and depth of burns; (b) rate of arrival of casualties to the hospital, and triage to ward or critical care settings; (c) eligibility for early discharge of non-MCI inpatients at time of MCI; (d) baseline occupancy of intensive care unit (ICU), surgical step-down, and ward; (e) staff availability—number of physicians, nurses, and respiratory therapists, and the expected ratio of each group to patients; (f) floor and operating room resources—anticipating the need for mechanical ventilators, burn care and surgical resources, blood products, and intravenous fluids; (g) average hospital length of stay and mortality rate for patients with inhalation injury and different size burns; and (h) average number of times that different size burns undergo surgery. Key model outputs include time to bottleneck for each limiting resource and average waiting time to hospital bed availability.

Results

Given base-case model assumptions (including 100 mass casualties with an inter-arrival rate to the hospital of one patient every three minutes), hospital utilization is constrained within the first 120 minutes to 21 casualties, due to the limited number of beds. The first bottleneck is attributable to exhausting critical care beds, followed by floor beds. Given this limitation in number of patients, the temporal order of the ensuing bottlenecks is as follows: Lactated Ringer's solution (4 h), silver sulfadiazine/Silvadene (6 h), albumin (48 h), thrombin topical (72 h), type AB packed red blood cells (76 h), silver dressing/Acticoat (100 h), bismuth tribromophenate/Xeroform (102 h), and gauze bandage rolls/Kerlix (168 h). The following items do not precipitate a bottleneck: ventilators, topical epinephrine, staplers, foams, antimicrobial non-adherent dressing/Telfa types A, B, or O blood. Nurse, respiratory therapist, and physician staffing does not induce bottlenecks.

Conclusions

This model, and similar models for non-burn-related MCIs, can serve as a real-time estimation and management tool for hospital capacity in the setting of MCIs, and can inform supply decision support for disaster management.

AbirM, DavisMM, SankarP, WongAC, WangSC. Design of a model to predict surge capacity bottlenecks for burn mass casualties at a large academic medical center. Prehosp Disaster Med. 2013;28(1):1-10.
Morphological disambiguation of Hebrew: a case study in classifier combination
Authors: LEMBERSKY GENNADI , SHACHAM DANNY , WINTNER SHULY
Published: November 2012

Morphological analysis and disambiguation are crucial stages in a variety of natural language processing applications, especially when languages with complex morphology are concerned. We present a system which disambiguates the output of a morphological analyzer for Hebrew. It consists of several simple classifiers and a module that combines them under the constraints imposed by the analyzer. We explore several approaches to classifier combination, as well as a back-off mechanism that relies on a large unannotated corpus. Our best result, around 83 percent accuracy, compares favorably with the state of the art on this task.
Climate change and internal migration patterns in Bangladesh: an agent-based model
Authors: Hassani-Mahmooei Behrooz , Parris Brett W.
Published: November 2012

Bangladesh is one of the countries most vulnerable to climate change impacts such as extreme weather events, due to its low-lying topography, high population density and widespread poverty. In this paper, we report on the development and results of an agent-based model of the migration dynamics that may arise in Bangladesh as a result of climate change. The main modules are each calibrated with data on relevant indicators, such as the incidences of extreme poverty, socioeconomic vulnerability, demography, and historical drought, cyclone and flood patterns. The results suggest likely changes in population densities across Bangladesh due to migration from the drought-prone western districts and areas vulnerable to cyclones and floods in the south, towards northern and eastern districts. The model predicts between 3 and 10 million internal migrants over the next 40 years, depending on the severity of the hazards. Some associated policy considerations are also discussed.