bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collapse Detection and Avoidance for SIP
Architectures
Authors: Egger Christoph , Happenhofer Marco , Fabini Joachim , Reichl Peter 
Published: September 2012

Abstract
The Session Initiation Protocol (SIP) relies on timer-based message
retransmission for safeguarding reliable message transfer when deployed on top
of the unreliable User Datagram Protocol (UDP) over IP. In this paper we present
a detailed impact analysis of SIP timers onto the functionality of a system and
its capabilities to recover from overload situations. The results of our
event-based SIP simulations demonstrate that message retransmissions originating
from a minor short-term overload can force a system into a deterministic
congestion collapse when using default SIP timer settings. A recovery from this
severe system overload situation is highly difficult or impossible, even if the
system load is reduced substantially afterward. Our performance evaluation shows
that an increase of timer T1's value significantly enhances the stability,
robustness and the ability of systems to handle overload, whereas the resulting
increase of response times is relatively small and overall system responsiveness
can even improve in some cases. We propose an algorithm for implicit collapse
detection as solution for dynamic timer T1 optimization. Based on monitoring of
system load and pending transaction counts, our algorithm enables intermediate
SIP proxies to detect congestion in a very early phase, allowing them to
counteract in time, i.e., to modify timers and reject new system load in order
to prevent the system from collapse.
The effect of mechanical alloying on Al2O3 distribution and properties of Al2O3 particle reinforced Al-MMCs
Authors: Canakci Aykut , Varol Temel , Ertok Saban 
Published: September 2012

AbstractThe properties of particle-reinforced aluminum composites depend on the microstructure and evolved uniformity distribution of particles in the matrix. The distribution of Al2O3 particles in the matrix and microstructure properties of varying volume fraction of particles up to 15% Al2O3 particle-reinforced Al metal matrix composites produced by the mechanical alloying technique was investigated. Alloying was performed in a planetary ball mill using a milling time varying from 0 h to 7 h, a ball-to-powder ratio of 10:1, and a ball mill velocity of 400 rpm. The produced compositions were cold-pressed at 700 MPa with a single action and sintered at 600°C for 3 h under Argon gas atmosphere. The relative density (both pressed and sintered), porosity and hardness of composites were also examined. The results of mechanical alloying processing were investigated with scanning electron microscopy (SEM), X-ray diffraction and laser particle size analyzer. SEM observations showed that relatively homogeneous distribution of Al2O3 reinforcement in the matrix could be obtained by mechanical alloying after 5 h. Moreover, the variation in hardness of the composites with alumina volume fraction and milling time was observed to be a strong function of the work hardening mechanism.
Experimental study of the impact behavior of laminated composites stricken by sharp impactors
Authors: Uyaner Mesut , Kara Memduh 
Published: September 2012

AbstractIn this study, the influence of the impactor shape on the dynamic response of E-glass/epoxy laminates was investigated. Composite samples were impacted using steel 90° and 120° conical, 24 mm and 12 mm in diameter hemispherical, pyramidal impactors via a specially developed drop weight test machine. The impact tests were performed at impactor mass (20 kg) for impact velocity (2.5 m/s). Plate specimens consisting of 18 plies for tests (180×50 mm) with a nominal thickness (7 mm) were used. Contact force-time and contact force-deflection data obtained from the experiments were interpreted. It was found that the contact force was smaller in the 90° conical impactor while it was bigger in the 24 mm hemispherical one. Absorbed energies were also investigated. The absorbed energy obtained for pyramidal impactor was greater than that of the others. Furthermore, overall damage areas caused by the impactor were evaluated.
Morphology and NMR Self-Diffusion in PBA/PEO Miktoarm Star Copolymers
Authors: Makrocka-Rydzyk Monika , Wegner Katarzyna , Szutkowski Kosma , Kozak Maciej , Jurga Stefan , Gao Haifeng , Matyjaszewski Krzysztof 
Published: September 2012

AbstractMorphology and NMR self-diffusion of two miktoarm star copolymers differing in fraction of poly(n-butyl acrylate) and poly(ethylene oxide) (PBA and PEO) arms were under investigation. Structural characteristics of copolymers was obtained on the basis of Small Angle X-Ray Scattering (SAXS) investigations. The phase separated nanoscale morphology of the miktoarm star copolymer with a high fraction of PEO arms was confirmed by Scanning Probe Microscopy (SPM) studies. The modified Avrami approach was used to obtain the information on the non-isothermal crystallization kinetics of the studied systems. It was observed that the crystallization in the system with a higher content of PBA, occurring at higher undercooling, was characterized by a higher crystallization rate. It was also found that increase in PBA arms fraction leads to the reduction in the size of PEO domains. The activation energy of the crystallization process, estimated with Kissinger's method, is lower for miktoarm star copolymer with higher PBA content, which results from facilitation of the transport of PEO chains in the direction of the growing crystal due to the presence of mobile PBA arms. The self-diffusion studies of miktoarm star copolymers melts, carried out with the Pulsed-Gradient STimulated-Echo (PGSTE) Nuclear Magnetic Resonance (NMR) technique, reveals the existence of at least two types of diffusion mechanisms in these systems.
Genetic and Genomic Toolbox of the Chordate Ciona intestinalis
Authors: Stolfi Alberto , Christiaen Lionel 
Published: September 2012

Abstract
The experimental malleability and unique phylogenetic position of the sea squirt Ciona intestinalis as part of the sister group to the vertebrates have helped establish these marine chordates as model organisms for the study of developmental genetics and evolution. Here we summarize the tools, techniques, and resources available to the Ciona geneticist, citing examples of studies that employed such strategies in the elucidation of gene function in Ciona. Genetic screens, germline transgenesis, electroporation of plasmid DNA, and microinjection of morpholinos are all routinely employed, and in the near future we expect these to be complemented by targeted mutagenesis, homologous recombination, and RNAi. The genomic resources available will continue to support the design and interpretation of genetic experiments and allow for increasingly sophisticated approaches on a high-throughput, whole-genome scale.
Temporal Dimensions of the Fertility Transition: An Age-Period-Cohort Analysis of Frontier Fertility
Authors: Hsueh Yung-Chang , Anderton Douglas L. 
Published: September 2012

This paper evaluates age, period, and cohort effects on marital fertility during onset of the Utah fertility transition (1880–1909). Computerized genealogies are used to derive age–period–cohort fertility rates for 49,842 once-married couples. Age, period and cohort effects on marital fertility are then estimated using Johnson's (1985) relational model. Declining marital fertility in Utah is shown to be explained by both lower fertility levels across periods and increasing age-specific limitation across cohorts. Direct cohort effects on fertility are insignificant. These results are consistent with prior research, and the view that fertility levels were adaptive (in part through birth spacing across ages) to immediate contexts of childbearing while age-specific fertility truncation increased across cohorts (in part through the more general diffusion of contraceptive innovations).
L’habilitation des nouveaux préposés aux bénéficiaires par le groupe de pairs dans les organisations gériatriques de type CHSLD au Québec
Authors: Aubry François , Couturier Yves 
Published: September 2012

L’objectif de cet article est de démontrer en quoi l’intégration de nouveaux préposés aux bénéficiaires dans les CHSLD au Québec peut être analysée comme un processus d’habilitation, c’est-à-dire de construction identitaire des recrues par le groupe de pairs, à travers deux phases spécifiques : les préposés expérimentés jugent rapidement la capacité de la recrue à supporter la lourde charge de travail durant la phase dite d’ « orientation », en sélectionnant les recrues selon ce critère ; puis ils transmettront certaines compétences informelles aux recrues sélectionnées et considérées comme capables de faire partie du groupe de pairs.
La Solana del Castell (Xàtiva). Campaña de 2010
Authors: Pérez Ballester José , Velasco Berzosa Angel , Borredá Mejías Reyes , Rodríguez Traver José Antonio 
Published: September 2012

Resumen de las actividades referentes a la campaña de excavaciones de 2010 en La Solana del Castell (Xàtiva).
Metabolic Labeling with Noncanonical Amino Acids and Visualization by Chemoselective Fluorescent Tagging
Authors: tom Dieck Susanne , Müller Anke , Nehring Anne , Hinz Flora I. , Bartnik Ina , Schuman Erin M. , Dieterich Daniela C. 
Published: September 2012

AbstractFluorescent labeling of proteins by genetically encoded fluorescent protein tags has enabled an enhanced understanding of cell biological processes but is restricted to the analysis of a limited number of identified proteins. This approach does not permit, e.g., the unbiased visualization of a full proteome in situ. We describe here a fluorescence‐based method to follow proteome‐wide patterns of newly synthesized proteins in cultured cells, tissue slices, and a whole organism. This technique is compatible with immunohistochemistry and in situ hybridization. Key to this method is the introduction of a small bio‐orthogonal reactive group by metabolic labeling. This is accomplished by replacing the amino acid methionine by the azide‐bearing methionine surrogate azidohomoalanine (AHA) in a step very similar to classical radioisotope labeling. Subsequently, an alkyne‐bearing fluorophore is covalently attached to the group by “click chemistry”—a copper(I)‐catalyzed [3+2]azide‐alkyne cycloaddition. By similar means, metabolic labeling can also be performed with the alkyne‐bearing homopropargylglycine (HPG) and clicked to an azide‐functionalized fluorophore. Curr. Protoc. Cell Biol. 56:7.11.1‐7.11.29. © 2012 by John Wiley & Sons, Inc.
Chick Embryo Culture and Electroporation
Authors: Endo Yukinori 
Published: September 2012

AbstractImportant events in embryonic development such as gastrulation, neurulation, and cranial neural crest development occur in ectodermal tissues during vertebrate embryonic development. Although the chicken embryo is a well‐established model system in developmental biology, problems of accessibility of the ectoderm for experimental manipulation and an inability to generate gene knockouts previously impeded studies of gene regulation and key processes during chicken gastrulation and neurulation. The technique of in ovo electroporation permits genetic manipulation and provides a powerful animal model. However, the problem of accessibility to the ectoderm in ovo requires an ex ovo whole‐embryo culture approach combined with electroporation. This unit provides convenient and reproducible whole‐embryo ex ovo culture and electroporation protocols. These chicken embryo culture protocols can be used not only for gene regulatory experiments, but also for time‐lapse imaging of the dynamics of early vertebrate development. Curr. Protoc. Cell Biol. 56:19.15.1‐19.15.10. © 2012 by John Wiley & Sons, Inc.
Analysis of Interactions Between Genomic Loci Through Chromosome Conformation Capture (3C)
Authors: El Kaderi Belal , Medler Scott , Ansari Athar 
Published: September 2012

AbstractGenome architecture plays a significant role in the regulation of DNA‐based cellular processes such as transcription and recombination. The successful accomplishment of these processes involves coordinated interaction of DNA elements located at a distance from each other. The ‘Chromosome Conformation Capture’ (3C) assay is a convenient tool for identification of physical association between spatially separated DNA elements in a cell under physiological conditions. The principle of 3C is to convert physical chromosomal interactions into specific DNA ligation products, which are then detected by PCR. The 3C protocol was originally used to identify long‐range, stable chromosomal interactions in yeast. Here we describe a modified 3C procedure that can detect transient, short‐range interactions of DNA elements separated by a distance of less than 700 bp. This method has been successfully used to detect dynamic interaction of transcription regulatory elements in yeast and can be used for detecting similar interactions of other genomic regions. Curr. Protoc. Cell Biol. 56:22.15.1‐22.15.21. © 2012 by John Wiley & Sons, Inc.
Silylketenimine – vielseitige Nucleophile für die katalytische asymmetrische Synthese
Authors: Denmark Scott E. , Wilson Tyler W. 
Published: September 2012

AbstractDieser Kurzaufsatz bietet einen Überblick über die Entwicklung von Silylketeniminen und deren jüngste Anwendungen in katalytischen enantioselektiven Reaktionen. Die einzigartige Struktur von Keteniminen macht verschiedenste Reaktionsmuster möglich und liefert Lösungen für die bestehenden Herausforderungen beim enantioselektiven Aufbau von quartären Kohlenstoffstereozentren und Kreuz‐Benzoinaddukten. Es wird eine Vielzahl an Reaktionen präsentiert, bei denen Silylketenimine eingesetzt wurden. Unser Ziel ist dabei, zum Nachdenken über neue Anwendungsmöglichkeiten dieser nur unzureichend genutzten Nucleophile anzuregen.
When Disaster Strikes in Time of War: Traditional Healing and Psychosocial Training Help Divided Communities Mourn Together
Authors: Preitler Barbara 
Published: September 2012

ABSTRACTIn December 2004 a tsunami destroyed the whole coastal line, killing more than 10,000 people in the district of Ampara alone and left many injured and homeless. But even before 2004 the whole population had faced 20 years of civil war, and in 2006 this war started again. People suffer from the separation from loved ones due to death or disappearance through natural disaster, man‐made disaster and destruction, or separation from displacement out of poverty. A systematic long‐term training program for trauma counseling in Sri Lanka was started soon after the tsunami in the beginning of 2005. Located in the Ampara District, a Center for Psychosocial Care was created to address the special needs of children and youth. The program taught basic developmental psychology, special affects of traumatization on children, sequential traumatization, and forms of psychological interventions and psychotherapeutic approaches. Western concepts were discussed in respect to case stories from eastern Sri Lanka and Sri Lankan cultural practices and beliefs. An amalgamation of Western theoretical knowledge and Sri Lankan traditions and history created a new, culturally appropriate approach for working‐through trauma and grieving. Mindful intervention by Westerners and recognition of social and political climates, allowed for our students to own the program and individuals to control their own healing processes. Copyright © 2012 John Wiley & Sons, Ltd.
Benzo[c]thiophene–C60 Diadduct: An Electron Acceptor for p–n Junction Organic Solar Cells Harvesting Visible to Near‐IR Light
Authors: Zhen Yonggang , Obata Naoki , Matsuo Yutaka , Nakamura Eiichi 
Published: September 2012

AbstractWe synthesized a new 56‐π‐electron fullerene derivative through a Diels–Alder cycloaddition of benzo[c]thiophene that featured a relatively low temperature, closer to stoichiometric use of the diene, and easy product purification. The 56‐π‐electron benzo[c]thiophene diadduct (BTCDA) has a LUMO energy level of 0.09 to 0.18 eV higher than that of 58‐π‐electron fullerenes, and therefore, the BTCDA‐based organic photovoltaic device exhibited a higher open‐circuit voltage and power‐conversion efficiency (PCE). When used with a binary‐donor system, including visible‐light‐harvesting tetrabenzoporphyrin (BP) and near‐IR‐harvesting titanyl phthalocyanine (TiOPc), the device had a PCE that was 1.5–3 times higher (2.8 %) than that for devices with BP or TiOPc alone because the binary‐donor device can utilize light between λ=350 and 950 nm.
Rotation‐Locked 2,6‐Pyrido‐allenophanes: Characterization of all Stereoisomers
Authors: Lahoz Inmaculada R. , Navarro‐Vázquez Armando , Llamas‐Saiz Antonio L. , Alonso‐Gómez José Lorenzo , Cid M. Magdalena 
Published: September 2012

AbstractNew 2,6‐disubstituted pyrido‐allenophanes with locked rotation of aromatic spacers were designed and synthesized. The synthesis was accomplished by Pd‐catalyzed C(sp2)–C(sp) Sonogashira cross‐coupling reaction between 1,3‐diethynylallene (DEA) and 2,6‐dibromopyridine followed by an intermolecular ring closure. Because racemic DEA was employed, pyrido‐allenophanes were obtained as mixtures of stereoisomers that were resolved by preparative HPLC. The conformational space of all these diastereoisomers was explored at the CAM‐B3LYP/6‐31+G*//AM1 level of theory. The isomers were characterized through their symmetry properties revealed in NMR, circular dichroism, and chiral stationary‐phase HPLC experiments. X‐ray diffraction was used to assign and to corroborate the configuration of several diastereoisomers. The unexpected encapsulation of two molecules of CHCl3 in the crystal structures shows the potential of these conformationally hampered allenophanes as encapsulating hosts.
Iminium Ions as Dienophiles in Aza‐Diels–Alder Reactions: A Closer Look
Authors: Memeo Misal Giuseppe , Quadrelli Paolo 
Published: September 2012

AbstractThis review highlights the state of the art of the use of iminium ions as dienophiles in Aza‐Diels–Alder (ADA) cycloadditions. An historical survey spanning the very first discovery of the reaction to modern developments, mechanistic studies and synthetic applications of the iminium variant of the ADA (iADA) reaction are presented. The discussion is focused on the intermolecular and intramolecular versions of the iADA reactions that are conducted in aqueous solutions to generate, in situ, the reactive dienophile from an amine hydrochloride and either aliphatic or aromatic aldehydes in the presence of a variety of dienes. The retro‐ADA reaction is also presented as an interesting method for the protection of amines. The use of Lewis acid catalysis in these reactions was thoroughly studied by the reactions of different amines and aldehydes conducted in the presence of lanthanide(III) complexes.
Highly Sensitive and Fast‐Responsive Fluorescent Chemosensor for Palladium: Reversible Sensing and Visible Recovery
Authors: Li Honglin , Fan Jiangli , Hu Mingming , Cheng Guanghui , Zhou Danhong , Wu Tong , Song Fengling , Sun Shiguo , Duan Chunying , Peng Xiaojun 
Published: September 2012

AbstractThe well‐known rhodamine spiro‐lactam framework offers an ideal model for the development of fluorescence‐enhanced chemosensors through simple and convenient syntheses. Herein, we report a new tridentate PNO receptor, which was introduced into a rhodamine spiro‐lactam system to develop Pd2+‐chemosensor RPd4, that displayed significantly improved sensing properties for palladium. Compound RPd4 shows a very fast response time (about 5 s), high sensitivity (5 nM), and excellent specificity for Pd2+ ions over other PGE ions (Pt2+, Rh3+, and Ru3+). In addition, RPd4 displays quite different responses to different valence states of the Pd ions, that is, very fast response towards Pd2+ ions but slow response towards Pd0, which may provide us with a convenient method for the selective discrimination of Pd species in different valence states. According to proof‐of‐concept experiments, RPd4 has potential applications in Pd2+‐analysis in drug compounds, water, soil, and leaf samples. Owing to its good reversibility, RPd4 can also be used as a sensor material for the selective detection and visual recovery of trace Pd2+ ions in environmental samples.
Asymmetric Hydrogenation of α,β‐Unsaturated Carboxylic Esters with Chiral Iridium N,P Ligand Complexes
Authors: Woodmansee David H. , Müller Marc‐André , Tröndlin Lars , Hörmann Esther , Pfaltz Andreas 
Published: September 2012

AbstractEnantioselective conjugate reduction of a wide range of α,β‐unsaturated carboxylic esters was achieved using chiral Ir N,P complexes as hydrogenation catalysts. Depending on the substitution pattern of the substrate, different ligands perform best. α,β‐Unsaturated carboxylic esters substituted at the α position are less problematic substrates than originally anticipated and in some cases α‐substituted substrates actually reacted with higher enantioselectivity than their β‐substituted analogues. The resulting saturated esters with a stereogenic center in the α or β position were obtained in high enantiomeric purity.
DNA Binding, Antioxidant Activity, and DNA Damage Protection of Chiral Macrocyclic Mn(III) Salen Complexes
Authors: Pandya Nirali , Khan Noor‐ul H. , Prathap K. Jeya , Kureshy Rukhsana I. , Abdi Sayed H. R. , Mishra Sandhya , Bajaj Hari C. 
Published: September 2012

ABSTRACTWe are reporting the synthesis, characterization, and calf thymus DNA binding studies of novel chiral macrocyclic Mn(III) salen complexes S‐1, R‐1, S‐2, and R‐2. These chiral complexes showed ability to bind with DNA, where complex S‐1 exhibits the highest DNA binding constant 1.20 × 106 M−1. All the compounds were screened for superoxide and hydroxyl radical scavenging activities; among them, complex S‐1 exhibited significant activity with IC50 1.36 and 2.37 μM, respectively. Further, comet assay was used to evaluate the DNA damage protection in white blood cells against the reactive oxygen species wherein complex S‐1 was found effective in protecting the hydroxyl radicals mediated plasmid and white blood cells DNA damage. Chirality 24:1063–1073, 2012.© 2012 Wiley Periodicals, Inc.
Construction of River Channel‐wetland Networks for Controlling Water Pollution in the Pearl River Delta, China
Authors: Fan Xiaoyun , Cui Baoshan , Zhang Kejiang , Zhang Zhiming , Zhao Hui 
Published: September 2012

AbstractWater pollution has been a serious problem with rapid urban development in the Pearl River Delta. In the paper, a river channel‐wetland network (RCWN) was constructed to improve the situation of water pollution. At first, the assimilative capacity of each river was calculated for the main pollutants (biological oxygen demand and ammonia nitrogen selected) to investigate the water pollution degree; secondly, sites of wetlands used to alleviate the water pollution level of the heavily polluted rivers were identified according to original water bodies; then, the wetland areas connected with rivers were determined by analyzing wetland uptake rate, pollutant amount needed to reduce and the retention time. Based on the information above, the RCWN was constructed by connecting river channels with wetlands, here the wetlands and the confluences of river channels were used as the nodes, and river channels were used as the links between nodes. The results showed with the different retention time, the largest wetland areas required by the RCWN were also different for better improving the river water quality, and the wetland areas would be reduced with the retention time increased. The network composed of river channel and wetlands could efficiently control river water pollution. This study provides a useful tool for river water resources management based on the best available data and knowledge.