bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal Properties and Intermolecular Interaction of Blends of Poly(ethylene oxide) and Poly(methyl acrylate)
Authors: Halim Suhaila Idayu Abdul , Chan Chin Han , Sim Lai Har 
Published: July 2016

SummaryPolymer blends of poly(ethylene oxide) (PEO) and poly(methyl acrylate) (PMA) were prepared by solution casting method. Thermal stability of the binary PEO/PMA blends was examined by termogravimetric analysis (TGA). Decomposition temperatures of the binary blends were estimated from the onsets of the weight loss curves of TGA thermograms. The decomposition temperatures of the blends increase when the content of PEO elevates. Hence, PEO has a better thermal stability as compared to PMA. The activation energy of thermal decomposition of each sample was calculated from the initial stage of the decomposition. Quantities of EA increase when content of PEO increases in the blends. Differential scanning calorimeter (DSC) was used to investigate the thermal properties of binary PEO/PMA blends. An existence of a single and composition‐dependent glass transition temperature (Tg) for the blends indicates the miscibility of the PEO/PMA blends. The Tgs of PEO/PMA blends increase when PMA content increases. Furthermore, when PMA is blended with PEO, the crystallinity (X*) and melting temperature (Tm) of PEO in PEO/PMA blends are depressed. Thus, the miscibility of the blends in the molten state is in agreement with Tg results. Fourier‐transform infrared (FTIR) spectroscopy was used to study the intermolecular interaction of between PEO and PMA in the blends. The characteristic absorbance bands of ether and carbonyl groups of PEO and PMA were examined by FTIR. PEO and PMA only display weak van der Waals interactions in blends. Hence the miscibility of PEO and PMA in the blends may be more towards the entropic effect instead of the enthalpic effect.
Experimental Investigation of Dynamic Fracture Behaviors of Polymethyl Methacrylate
Authors: Gao Guiyun , Zhou Jie , Li Zheng 
Published: July 2016

SummaryDynamic fracture of polymers plays a vital role in engineering applications. Dynamic fracture behaviors of polymethyl methacrylate were studied using the optical method of caustics. Semi‐circular bending specimens were chosen for mixed‐mode fracture and crack interaction analysis. The crack initiation, crack propagation, stress intensity factor, and fracture toughness were obtained by analyzing the specke patterns captured during dynamic loading by high‐speed imaging techniques. The crack interactions of two symmetric and asymmetric cracks and the influence of damage, including the presence of holes and microcracks on or near the crack path, are discussed. The results show that two cracks on a specimen compete and interact with each other, and lead to the final fracture mode of the specimens. Holes and microcracks on or near the crack path influence the crack path and the crack propagation velocity. The results obtained in this paper could be extended to brittle fracture analysis of materials with multiple cracks or inclusions.
Sensitivity and Detonation Characteristics of Selected Nitramines Bonded by Sylgard Binder
Authors: Elbeih Ahmed , Mokhtar Mohamed Mohamed , Wafy Tamer 
Published: July 2016

AbstractFour plastic explosives based on cyclic nitramines and polymeric matrix were prepared and studied. The nitramines were RDX (1,3,5‐trinitro‐1,3,5‐triazinane), HMX (1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane), BCHMX (cis‐1,3,4,6‐tetranitro‐octahydroimidazo‐[4,5‐d]imidazole), and ϵ‐CL20 (ϵ‐2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane, ϵ‐HNIW). Sylgard 184 was used in the all PBXs prepared samples as a binder. The sensitivities to different mechanical stimuli were determined. The detonation velocities were experimentally measured. Detonation characteristics were calculated by EXPLO5 thermodynamic code. For comparison, standard plastic explosives, Composition C4, Semtex 10, and EPX‐1 were studied. Results showed that the experimental detonation velocities as well as the calculated detonation parameters decrease in the following order: CL20‐sylgard>HMX‐sylgard≥BCHMX‐sylgard>RDX‐sylgard. Calculations by EXPLO5 computer program resulted in detonation velocities close to the experimental ones with 3.1 % maximum difference. Urizar coefficient for the Sylgard binder was calculated from experimental data. An inverse linear relationship between friction sensitivity and heat of detonation of the studied samples was observed. Sylgard binder significantly decreased the sensitivity of all the studied nitramines. Among these prepared samples, the properties of BCHMX‐sylgard are similar to other ordinary plastic explosives.
Sensitiveness of Porous Silicon‐Based Nano‐Energetic Films
Authors: Plummer Andrew , Kuznetsov Valerian A. , Gascooke Jason , Shapter Joe , Voelcker Nicolas H. 
Published: July 2016

AbstractNanoporous silicon (pSi) films on a silicon wafer were loaded with sodium perchlorate and perfluoropolyether (PFPE) oxidizing agents. Sensitiveness to impact, friction and electrostatic discharge (ESD) of the resulting energetic thin films were investigated. It was observed that pSi loaded with perchlorate was sensitive at the lowest limit of detection for the available equipment (<4.9 J impact energy, <5 N friction force, and <45 mJ ESD spark energy). When loaded with PFPE the material was very sensitive to impact (<4.9 J), moderately sensitive to ESD (between 45 and 100 mJ) and insensitive to friction (>360 N). pSi loaded with either perchlorate or PFPE displayed behavior during sensitiveness testing similar to other primary explosive materials.
Spike timing in auditory‐nerve fibers during spontaneous activity and phase locking
Authors: Heil Peter , Peterson Adam J. 
Published: July 2016

AbstractIn vertebrates, all acoustic information transmitted from the inner ear to the central auditory system is relayed by primary auditory afferents (auditory‐nerve fibers; ANFs). These neurons are also the most peripheral elements to use action potentials (spikes) to encode the acoustic information. Here, we review what is known about the spiking of ANFs during spontaneous activity, when spike timing might be regarded as largely random, and during stimulation by low‐frequency sounds, when spikes are phase locked to the stimulus waveform, a phenomenon generally considered a hallmark of temporal precision and speed in the auditory system. We focus on mammals, in which each ANF is driven by a single ribbon synapse in a single receptor cell, but also cover relevant research on ANFs of vertebrates from other classes. For spontaneous activity, we highlight several spike‐history effects in interspike interval distributions, hazard‐rate functions, serial interval correlations, and spike‐count statistics. We also review models that have attempted to account for these properties. For phase locking, we focus on the responses to low‐frequency tones, rather than to low‐frequency components of broadband signals such as noise or clicks. We critically review the measures commonly used to quantify phase locking and urge caution when interpreting such measures with respect to spike‐timing precision. We also review the dependence of phase locking on stimulus amplitude and frequency. Finally, we identify some open questions.
Differential modulation for asynchronous two‐way relay systems over frequency‐selective fading channels
Authors: Salim Ahmad , Duman Tolga M. 
Published: July 2016

AbstractWe propose two schemes for asynchronous multi‐relay two‐way relay (MR‐TWR) systems in which neither the users nor the relays know the channel state information. In an MR‐TWR system, two users exchange their messages with the help of NR relays. Most of the existing works on MR‐TWR systems based on differential modulation assume perfect symbol‐level synchronization between all communicating nodes. However, this assumption is not valid in many practical systems, which makes the design of differentially modulated schemes more challenging. Therefore, we design differential modulation schemes that can tolerate timing misalignment under frequency‐selective fading. We investigate the performance of the proposed schemes in terms of either probability of bit error or pairwise error probability. Through numerical examples, we show that the proposed schemes outperform existing competing solutions in the literature, especially for high signal‐to‐noise ratio values. Copyright © 2016 John Wiley & Sons, Ltd.
The nuts and bolts of the endogenous spliceosome
Authors: Sperling Ruth 
Published: July 2016

The complex life of pre‐mRNA from transcription to the production of mRNA that can be exported from the nucleus to the cytoplasm to encode for proteins entails intricate coordination and regulation of a network of processing events. Coordination is required between transcription and splicing and between several processing events including 5′ and 3′ end processing, splicing, alternative splicing and editing that are major contributors to the diversity of the human proteome, and occur within a huge and dynamic macromolecular machine—the endogenous spliceosome. Detailed mechanistic insight of the splicing reaction was gained from studies of the in vitro spliceosome assembled on a single intron. Because most pre‐mRNAs are multiintronic that undergo alternative splicing, the in vivo splicing machine requires additional elements to those of the in vitro machine, to account for all these diverse functions. Information about the endogenous spliceosome is emerging from imaging studies in intact and live cells that support the cotranscriptional commitment to splicing model and provide information about splicing kinetics in vivo. Another source comes from studies of the in vivo assembled spliceosome, isolated from cell nuclei under native conditions—the supraspliceosome—that individually package pre‐mRNA transcripts of different sizes and number of introns into complexes of a unique structure, indicating their universal nature. Recent years have portrayed new players affecting alternative splicing and novel connections between splicing, transcription and chromatin. The challenge ahead is to elucidate the structure and function of the endogenous spliceosome and decipher the regulation and coordination of its network of processing activities. WIREs RNA 2017, 8:e1377. doi: 10.1002/wrna.1377This article is categorized under:

RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes
RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications
RNA Processing > Splicing Regulation/Alternative Splicing
Gallium‐Indium Ordering in the Complex [Ni2Ga3In] Network of GdNi2Ga3In
Authors: Galadzhun Yaroslav V. , Horiacha Myroslava M. , Nychyporuk Galyna P. , Rodewald Ute Ch. , Pöttgen Rainer , Zaremba Vasyl I. 
Published: July 2016

AbstractPolycrystalline samples of the isotypic quaternary compounds RENi2Ga3In (RE = Y, Gd – Tm) were obtained by arc‐melting of the elements. Crystals of the gadolinium compound were found by slow cooling of an arc‐melted button of the initial composition “GdNiGa3In”. All samples were characterized by powder X‐ray diffraction. The structure of GdNi2Ga2.89In1.11 was refined from single‐crystal X‐ray diffractometer data: new type, Pnma, a = 2426.38(7), b = 418.17(2), c = 927.27(3) pm, wR2 = 0.0430, 1610 F2 values and 88 variables. Two of the six crystallographically independent gallium sites show a small degree of Ga/In mixing. The nickel atoms show tricapped trigonal prismatic coordination by gadolinium, gallium, and indium. Together, the nickel, gallium, and indium atoms build up a complex three‐dimensional [Ni2Ga3In]δ– network, which leaves cages for the gadolinium atoms. The indium atoms form zigzag chains with In–In distances of 337 pm. The crystal chemical similarities of the polyhedral packing in the GdNi2Ga3In and La4Pd10In21 structures are discussed.
Simple Approach to Predict Corrosion Inhibition Efficiency of Imidazole and Benzimidazole Derivatives as well as Linear Organic Compounds Containing Several Polar Functional Groups
Authors: Keshavarz Mohammad Hossein , Esmaeilpour Karim , Golikand Ahmad Nozad , Shirazi Zeinab 
Published: July 2016

AbstractA simple approach was introduced to predict the corrosion inhibition efficiency of some imidazole and benzimidazole derivatives as well as linear organic compounds containing several polar functional groups. In contrast to available predictive methods including quantitative structure‐activity relationship models (QSAR models) and quantum methods, there is no need to use complex computer codes and unusual complicated molecular descriptors as well expert users. For 34 nitrogen containing corrosion inhibitors, where the results of two complex models were available, the root mean squared (RMS) deviations of the new method is 4.58, which is much lower than the computed outputs of two available models. The RMS value of the new method is 6.15 for further eleven compounds, which confirm high reliability of the new correlation.
An Online Tool for Global Benchmarking of Risk‐Adjusted Surgical Outcomes
Authors: Spence Richard T. , Chang David C. , Chu Kathryn , Panieri Eugenio , Mueller Jessica L. , Hutter Matthew M. 
Published: July 2016

AbstractBackgroundIncreasing evidence demonstrates significant variation in adverse outcomes following surgery between countries. In order to better quantify these variations, we hypothesize that freely available online risk calculators can be used as a tool to generate global benchmarking of risk‐adjusted surgical outcomes.MethodsThis is a prospective cohort study conducted at an academic teaching hospital in South Africa (GSH). Consecutive adult patients undergoing major general or vascular surgery who met the ACS‐NSQIP inclusion criteria for a 3‐month period were included. Data variables required by the ACS risk calculator were prospectively collected, and patients were followed for 30 days post‐surgery for the occurrence of endpoints. Calculating observed‐to‐expected ratios for ten outcome measures of interest generated risk‐adjusted outcomes benchmarked against the ACS‐NSQIP consortium.ResultsA total of 373 major general and vascular surgery procedures met the inclusion criteria. The GSH operative cohort varied significantly compared to the 2012 ACS‐NSQIP database. The risk‐adjusted O/E ratios were significant for any complication O/E 1.91 (95 % CI 1.57–2.31), surgical site infections O/E 4.76 (95 % CI 3.71–6.01), renal failure O/E 3.29 (95 % CI 1.50–6.24), death O/E 3.43 (95 % CI 2.19–5.11), and total length of stay (LOS) O/E 3.43 (95 % CI 2.19–5.11).ConclusionFreely available online risk calculators can be utilized as tools for global benchmarking of risk‐adjusted surgical outcomes.
Clinical Significance of the Pre‐therapeutic Nodal Size in Patients Undergoing Neo‐Adjuvant Treatment Followed by Esophagectomy for Esophageal Squamous Cell Carcinoma
Authors: Mine Shinji , Watanabe Masayuki , Imamura Yu , Okamura Akihiko , Kurogochi Takanori , Sano Takeshi 
Published: July 2016

AbstractBackgroundThe clinical significance of pre‐therapeutic nodal size in patients with esophageal squamous cell carcinoma (ESCC) is not clear. We investigated whether nodal size was correlated with survival in patients undergoing neo‐adjuvant treatment followed by esophagectomy for ESCC.MethodsIn 2009–2013, 222 patients who underwent neo‐adjuvant treatment followed by esophagectomy for ESCC were enrolled in this retrospective study. Nodal size was measured along the short axis of the largest node using pre‐therapeutic CT images. Patients were then stratified based on this short axis, and nodal size was correlated with clinicopathological factors and survival.ResultsPatients with larger nodes were likely to have deeper cT, higher cN status, and poorer survival. Among the clinical factors cT, cN, cM, and nodal size, only cT and nodal size were independent prognostic factors in multivariate analysis [hazard ratio (HR) 2.0, 95 % confidence interval (CI) 1.1–3.5, p = 0.025 and HR 1.5, 95 % CI 1–2.3, p = 0.036, respectively]. In addition, nodal size was significantly associated with hematological recurrence (p = 0.007), but not lymphatic relapse (p = 0.272).ConclusionsThe short axis of the largest node before neo‐adjuvant treatment in patients with ESCC is a prognostic factor.
The divorce of Sporothrix and Ophiostoma: solution to a problematic relationship
Authors: de Beer Z.W. , Duong T.A. , Wingfield M.J. 
Published: July 2016

One of the causal agents of human sporotrichosis, Sporothrix schenckii, is the type species of the genus Sporothrix. During the course of the last century the asexual morphs of many Ophiostoma spp. have also been treated in Sporothrix. More recently several
DNA-based studies have suggested that species of Sporothrix and Ophiostoma converge in what has become known as Ophiostoma s. lat. Were the one fungus one name principles adopted in the Melbourne Code to be applied to Ophiostoma s. lat., Sporothrix would
have priority over Ophiostoma, resulting in more than 100 new combinations. The consequence would be name changes for several economically important tree pathogens including O. novo-ulmi. Alternatively, Ophiostoma could be conserved against Sporothrix, but
this would necessitate changing the names of the important human pathogens in the group. In this study, we sought to resolve the phylogenetic relationship between Ophiostoma and Sporothrix. DNA sequences were determined for the ribosomal large subunit and internal transcribed
spacer regions, as well as the beta-tubulin and calmodulin genes in 65 isolates. The results revealed Sporothrix as a well-supported monophyletic lineage including 51 taxa, distinct from Ophiostoma s. str. To facilitate future studies exploring species level resolution within
Sporothrix, we defined six species complexes in the genus. These include the Pathogenic Clade containing the four human pathogens, together with the S. pallida-, S. candida-, S. inflata-, S. gossypina- and S. stenoceras complexes, which include environmental
species mostly from soil, hardwoods and Protea infructescences. The description of Sporothrix is emended to include sexual morphs, and 26 new combinations. Two new names are also provided for species previously treated as Ophiostoma.
Symposium on Methodology: An Introductory Note
Authors: Henderson John P. 
Published: July 2016

Speculations as to what methodological approaches should be taken in academic endeavors such as African studies are bound to be controversial. Given the wide spectrum of the disciplines involved, ranging from art forms such as the dance and music to the “dismal science” of economics, obviously there are numerous differences of opinion as to the nature of research, not to mention its purposes. Internecine warfare is almost inevitable, and the claims of contending factions, even within a single discipline, are boundless. In some disciplines questions of methodology are paramount, as appears to be the case for political scientists and sociologists, while for others such as economists, the issue of method is less significant than are the policy implications of economic theory for the African scene. This difference may well reflect the greater abundance of economic data, for in some areas of inquiry the development of adequate data is the foremost problem. For some the productivity and pragmatism of results are the test of good research; for others, if research stands the test of criticism, it matters not the method. But for some, method itself provides the only criteria for judging the feasibility or value of research efforts.In this Symposium on Methodology, the Editors of the Review are pleased to publish the reflections of six social scientists as to the issues of research methodology in African studies, two each in the areas of anthropology, political science, and psychology.
“Village Life Is Better Than Town Life”: Identity, Migration, and Development in the Lives of Ugandan Child Citizens
Authors: Cheney Kristen E. 
Published: July 2016

Abstract:This article contextualizes Ugandan urban–rural relations through urban children's knowledge, imaginations, and experiences, which are affected by the present sociohistoric moment in Uganda. Influenced by urban–rural migration, changing notions of family and kinship, and the national government's prolific “development-through-education” campaign, urban schoolchildren imagine “the village” both as an integral imaginary space of ethnic identity origination and a location for fulfillment of national citizenship through development.
Zenzele: African Women's Self-Help Organizations in South Africa, 1927–1998
Authors: Higgs Catherine 
Published: July 2016

Abstract:The Zenzele clubs of the Eastern Cape of South Africa, which date from the late 1920s, were founded by mission-educated African women who sought to improve the lives of rural African women by enhancing their subsistence farming and cooking skills and educating them about household cleanliness, basic child care, and health care. Unlike associations for African women in British colonial Africa, Zenzele clubs did not evolve into political organizations. In the white-run segregated and apartheid states that persisted through 1994, Zenzele women did not engage in direct political action; rather, they sought to unite African women across class and ethnic lines and focused their efforts on community development.
The Civility of Incivility: Grassroots Political Activism, Female Farmers, and the Cameroon State
Authors: Diduk Susan 
Published: July 2016

Abstract:This essay examines the cultural symbolism underpinning “Takembeng,” a contemporary, rural-based social movement of female farmers in the Northwest Province of Cameroon. It argues that the power and success of women's activism, in the context of national opposition party politics and the “new struggles” for democracy, are embedded in an institutional history and culturally legitimate etiquette of moral censure. It also suggests that the highly disruptive but mystically charged nature of these mobilizations makes them effective because they open spaces for popular dissent on the national stage. Understanding the “civility” associated with the apparent incivility of activists is indispensable to understanding the dynamism of grassroots political activism.
Algeria: The Cycle of Reciprocal Fear
Authors: Lewis William H. 
Published: July 2016

In March 1962, France and Algeria, parties to seven years of conflict, agreed upon the need to destroy an illusion. For more than a century Algeria had been regarded as an integral part of metropolitan France, despite the patently non-Gallic character of its indigenous population. Bloody insurrection and the realization in France that the Mother Country could not undo the wrongs of previous generations brought the illusion into disrepute; it was interred in July 1962 with the acquisition of full independent status by Algeria. This separation restored France to a reasonable semblance of well-being; Algeria, on the other hand, suffered a far less happy fate.
At independence Algeria found itself on the threshold of renewed conflict. The principals in this second act of violence were not the European settlers (colons) who had dominated Algeria's political life for generations as baronial overlords. The vast majority of settlers, approximately 850,000 out of a total of one million, had scuttled and run out of fear of vengeful retribution by Algeria's nine million Muslims. Nor were the half-million French soldiers remaining on Algerian soil participants in the new drama; the overwhelming majority were anxious to depart this melancholy land without molestation. The principals were the founders and leaders of the Algerian revolution, men who, at the hour of triumph, fell into disagreement over the distribution of power and ignored a more compelling imperative - - the rehabilitation of a wartorn society.