bluuebunny/crossref_metadata_2025 huggingface dataset:
Combustion of hythane diluted with CO2
Authors: Hraiech Ibtissem , Sautet Jean-Charles , Yon Sébastien , Mhimid Abdallah
Published: July 2013

With increasing concern about energy shortage and environmental protection,
improving engine fuel economy and reducing exhaust emissions have become
major research topics in combustion and engine development. Hythane (a blend
of hydrogen H2 and natural gas NG) has generated a significant interest as an
alternative fuel for the future. This paper describes an experimental study
of the effects of CO2 addition on the stability of a turbulent jet diffusion
NG-H2 flame. The mole fraction of hydrogen (% H2) in NG-H2 mixture was varied
from 0% to 50%. The equivalence ratio of the hythane/CO2/air mixture was kept
at stoichiometry. The results show that the lift-off height increases with
the addition of CO2 at various % H2 content in hythane. However, we observe
that with 20% H2, we can obtain a stable flame diluted with 40% CO2, while
for 0% H2, the flame is blown out above 20% CO2. This means that the limits
of flame blowing out are pushed with the additions of H2. Moreover, the
results show that for %H2 content in NG-H2 fuel up to 10%, the addition of
CO2 could produce lifted flame if the % CO2 is low. At higher % CO2 dilution,
flame would remain attached until blow-out. This is mainly due to the fact
that the dilution leads to ejection velocities very high but reactivity of
the mixture does not change so the flame tends to stretch.
Radiative MHD compressible Couette flow in a parallel channel with a naturally permeable wall
Authors: Vyas Paresh , Srivastava Nupur
Published: July 2013

The paper pertains to investigations of thermal radiation effects on
dissipative MHD Couette flow of a viscous compressible Newtonian heat-
generating fluid in a parallel plate channel whose one wall is stationary and
naturally permeable. Saffman? slip condition is used at the clear
fluid-porous interface. The fluid is considered to be optically thick and the
radiative heat flux in the energy equation is assumed to follow Rossel and
approximation. The momentum and energy equations have closed form solutions.
The effects of various parameters on thermal regime are analyzed through
graphs and tables.
Modelling the effect of injection pressure on heat release parameters and nitrogen oxides in direct injection diesel engines
Authors: Yüksek Levent , Sandalci Tarkan , Özener Orkun , Ergenc Alp
Published: July 2013

Investigation and modelling the effect of injection pressure on heat release
parameters and engine-out nitrogen oxides are the main aim of this study. A
zero-dimensional and multi-zone cylinder model was developed for estimation
of the effect of injection pressure rise on performance parameters of diesel
engine. Double-Wiebe rate of heat release global model was used to describe
fuel combustion. extended Zeldovich mechanism and partial equilibrium
approach were used for modelling the formation of nitrogen oxides. Single
cylinder, high pressure direct injection, electronically controlled,
research engine bench was used for model calibration. 1000 and 1200 bars of
fuel injection pressure were investigated while injection advance, injected
fuel quantity and engine speed kept constant. The ignition delay of injected
fuel reduced 0.4 crank angle with 1200 bars of injection pressure and
similar effect observed in premixed combustion phase duration which reduced
0.2 crank angle. Rate of heat release of premixed combustion phase increased
1.75 % with 1200 bar injection pressure. Multi-zone cylinder model showed
good agreement with experimental in-cylinder pressure data. Also it was seen
that the NOx formation model greatly predicted the engine-out NOx emissions
for both of the operation modes.
Validation of the CFD code used for determination of aerodynamic characteristics of nonstandard AGARD-B calibration model
Authors: Vidanovic Nenad , Rasuo Bosko , Damljanovic Dijana , Vukovic Djordje , Curcic Dusan
Published: July 2013

The application of Computational Fluid Dynamics (CFD) is often motivated by
the limitations of measurement techniques, economic limitations, and complex
model geometry or, as it is in this case, the unavailability of appropriate
test model geometry. CFD was used to assess and evaluate scenario that cannot
be investigated experimentally and was shown to be an efficient and
economical option to experimental setup. Because of that, there is a strong
need for a validation procedure and assessment of the data obtained by
numerical simulation. A combined experimental/numerical procedure is
described for determination and estimation of subsonic and supersonic
aerodynamic behavior of an AGARD-B model with a nonstandard nose
configuration. Conducted numerical aerodynamic calculations needed to be
satisfied via experimental tests so, the CFD code validation procedure
required experimental data that characterize the distributions of measured
aerodynamic forces and moments which act upon the test model. Validation of
the CFD was achieved by performing the calculation for the model with the
standard nose shape as well, and by comparing the results of the CFD
calculations with available experimental data for the model with the standard
nose configuration. Comparison demonstrated very good agreement between
numerically and experimentally obtained results. It was concluded that the
numerical prediction for the similar nonstandard model configuration could be
accepted as reliable and used to estimate the corrections needed when
interpreting the available data. The effects of the different nose shape were
found to be small and noticeable mainly in the pitching moment coefficient.
This work also demonstrates the application of CFD for the purpose of proving
a qualitative and quantitative prediction of the aerodynamics behavior.
Transcriptional regulation of mouse mesencephalic astrocyte-derived neurotrophic factor in Neuro2a cells
Authors: Oh-Hashi Kentaro , Hirata Yoko , Kiuchi Kazutoshi
Published: July 2013

Mesencephalic astrocyte-derived neurotrophic factor (MANF) is a novel type of trophic factor. Recent studies indicate that the MANF gene is induced in response to endoplasmic reticulum (ER) stress through ER stress response element II (ERSE-II) in its 5′-flanking region. In this study, we evaluated the roles of six ER stress response transcription factors in the regulation of the promoter activities of the mouse MANF gene via ERSE-II using various types of mutant MANF luciferase reporter constructs. Treatment with thapsigargin (Tg) induced MANF mRNA generation in parallel with the elevation of ATF6α, sXBP and Luman mRNA levels in Neuro2a cells. Of the six transcription factors, ATF6β most strongly increased the MANF promoter activity via ERSE-II, while the effects of ATF6β and sXBP1 were moderate. However, overexpression of Luman or OASIS did not enhance ERSE-II-dependent MANF promoter activity in Neuro2a cells. To evaluate the relationships between transcription factors in the regulation of ERSE-II-dependent MANF promoter activity, we transfected two effective transcription factor constructs chosen from ATF6α, ATF6β, uXBP1 and sXBP1 into Neuro2a cells with the MANF reporter construct. The MANF promoter activity induced by co-transfection of ATF6α with ATF6β was significantly lower than that induced by ATF6α alone, while other combinations did not show any effect on the ERSE-II-dependent MANF promoter activity in Neuro2a cells. Our study is the first to show the efficiency of ER stress-related transcription factors for ERSE-II in activating the transcription of the mouse MANF gene in Neuro2a cells.
Identification of microRNAs potentially involved in male sterility of Brassica campestris ssp. chinensis using microRNA array and quantitative RT-PCR assays
Authors: Jiang Jianxia , Jiang Jingjing , Yang Yafei , Cao Jiashu
Published: July 2013

microRNAs (miRNAs) are a class of newly identified, noncoding, small RNA molecules that negatively regulate gene expression. Many miRNAs are reportedly involved in plant growth, development and stress response processes. However, their roles in the sexual reproduction mechanisms in flowering plants remain unknown. Pollen development is an important process in the life cycle of a flowering plant, and it is closely related to the yield and quality of crop seeds. This study aimed to identify miRNAs involved in pollen development. A microarray assay was conducted using the known complementary sequences of plant miRNAs as probes on inflorescences of a sterile male line (Bcajh97-01A) and a fertile male line (Bcajh97-01B) of the Brassica campestris ssp. chinensis cv. ‘Aijiaohuang’ genic male sterility sister line system (Bcajh97-01A/B). The results showed that 44 miRNAs were differently expressed in the two lines. Of these, 15 had over 1.5-fold changes in their transcript levels, with 9 upregulated and 6 downregulated miRNAs in inflorescences of ‘Bcajh97-01A’ sterile line plants. We then focused on 3 of these 15 miRNAs (miR158, miR168 and miR172). Through computational methods, 13 family members were predicted for these 3 miRNAs and 22 genes were predicted to be their candidate target genes. By using 5’ modified RACE, 2 target genes of miR168 and 5 target genes of miR172 were identified. Then, qRT-PCR was applied to verify the existence and expression patterns of the 3 miRNAs in the flower buds at five developmental stages. The results were generally consistent with those of the microarray. Thus, this study may give a valuable clue for further exploring the miRNA group that may function during pollen development.
The Role of the Dance Dramaturg: The Practical Necessities
Authors: Langley Elizabeth
Published: July 2013

ABSTRACT:

As a dramaturge, I mostly work on original creations during late rehearsals and production. Parallel to the survival and development of my own creativity, my dedication has always been to establish relationships with students and fellow artists, awarding them the same privileges that I would like others to bestow on me. I want my process and creation to be respected and I want to be encouraged and led by my dramaturge to explore what is not being communicated to its fullest potential. The artist’s work has nothing to do with the creative ideas of the dramaturge and limiting access to context establishes and protects this factor. It is the information withheld, the questions asked, and the verbal exchanges that can help achieve the desired results. Proof of success is when the artist is personally confident that what they want to communicate is strong and clear.
Paradoxes of the Dance Dramaturg
Authors: Montaignac Katya , Esling Natalia
Published: July 2013

ABSTRACT:

In dance, the dramaturg’s duty corresponds for the most part to an ”art of watching.” The dramaturg’s process is part of a relationship that is at once intimate and distant. As an accomplice he/she is accompanying the choreographer in the development and structuring of the dance work. In fact, the dramaturg actively participates in its conception through his/her reflection, perception, and questioning. In this way, the dramaturg places himself/herself in a paradoxical position: at once outside and inside, both a stranger and partner, a critic and confidante. Although the dramaturg works from behind the scenes, his/her role is essential: he/she is interrogating the choreographer about intentions and artistic decisions with the purpose of helping him/her articulate (and accept) ideas that are often unconscious or intuitive.
Friendship Is No Day Job—and Other Thoughts of a Resident Dance Dramaturg
Authors: Zimmer Jacob
Published: July 2013

The article is a reflection on the role of the dramaturge at a repertory dance company and the complexities of this position. Zimmer was the resident dramaturge at Dancemakers and the Centre for Creation and considers the relationship between dramaturgy and friendship.
Navigating a Continuum: MFA Dance Dramaturgy Research at York University
Authors: Callison Darcey
Published: July 2013

This short article reflects the critical thinking that culminated in the creation of a dance dramaturgy practiced-based field of research and education at York University. Reflecting on the continuum of diverse dramaturgical dance practices, the article argues that a definition of dance dramaturgy is not needed, but space and time to research and develop dramaturgical methodologies are needed to advance the field.
What Are You Doing? Dramaturgical Approaches to Eesti: Myths and Machines
Authors: Brown Lois
Published: July 2013

ABSTRACT:

What are you doing? Dramaturgical approaches to ”Eesti: Myths and Machines’ is an account of Lois Brown’s exploration of her deepening dramaturgical approaches and examination of meaning-making in the creation and rehearsal process for choreographer Peter Trostmer’s Eesti: Myths and Machines. Primary accounts of the process from Peter, Lois, and collaborator Thea Patterson discuss consensus, conflict, and reflection. Writing, Video-documentation, note-taking, and journaling are analyzed as dramaturgical tools.
Moving Thoughts
Authors: Barton Bruce
Published: July 2013

ABSTRACT:

Bruce Barton considers the challenges in arriving at an effective vocabulary for describing movement dramaturgy in theatre and dance. He reviews his own practice as a movement dramaturg over 25 years of professional practice, offering descriptions of his function and role in several current case study situations (Theatre Gargantua, bluemouth inc., Kaeja d’Dance). Ultimately, Barton proposes the concept of ”inter/actuality’ as a ”dramaturgical perspective that can allow creator/performers to recognize and work with what a performance is doing, rather than what it is trying to be.’
Transmission: Dramaturgical Bodies
Authors: Taylor Heidi , Marquardt Tanya
Published: July 2013

ABSTRACT:

”Transmission: Dramaturgical Bodies’ reflects on the experience of the creation and rehearsal process of Tanya Marquardt’s play Transmission. It recognizes aspects of the process that were unique to the collaborative team, while identifying larger principles at work in the dramaturgical system for the piece. Quoting from emails with creator Tanya Marquardt, the article describes the creative genesis and rehearsal strategies that developed the ensemble while generating material. Finally, it places the dramaturg’s body firmly in the midst of the creation process, while recognizing the inherent dramaturgical roles of the actors’ bodies as well.
Ground-penetrating radar measurements of 64 Austrian glaciers between 1995 and 2010
Authors: Fischer Andrea , Kuhn Michael
Published: July 2013

The ongoing retreat of mountain glaciers necessitates the development of future scenarios of glacier runoff. These scenarios are not only governed by future climate scenarios influencing glacier mass balance but also by the glacier volumes, which are subject to melt. Ground-penetrating radar (GPR) is a valuable tool for measuring the thickness of mountain glaciers, although ground-based measurements are labour-intensive, so not all glaciers can be surveyed. This study presents the results of GPR surveys on 64 Alpine glaciers, carried out between 1995 and 2010. The glacier areas range from 0.001 to 18.4 km2, and their ice thickness was surveyed with an average density of 36 points km-2. The point measurements were extrapolated manually to derive volume maps. The mean ice thickness varies between 10 and 92 m; the maximum ice thickness is about three times the mean thickness. According to the glacier state recorded in the second glacier inventory, the 64 glaciers cover an area of 223.3 ± 3.6 km2, with a mean thickness of 50 ± 3 m and a glacier volume of 11.9 ± 1.1 km3. The mean maximum ice thickness is 119 ± 5m.
Changes in ice thickness and flow velocity of Yala Glacier, Langtang Himal, Nepal, from 1982 to 2009
Authors: Sugiyama Shin , Fukui Kotaro , Fujita Koji , Tone Kenta , Yamaguchi Satoru
Published: July 2013

To investigate recent glacier changes in the Himalayan region, we carried out GPS and ground-penetrating radar (GPR) measurements at Yala Glacier, a benchmark glacier in Nepal. Glacier surface elevation and ice thickness were surveyed along a 1.5 km profile from the glacier top to the terminus. Ice flow velocity was measured at five locations by surveying stakes for either 1 year or 4 day periods. Obtained surface elevation and ice velocity were compared with those measured in 1982 and 1996. The mean ice thickness along the radar profile was 36 m in 2009 and the ice has been thinning at rates of-0.69 ±0.25 and -0.75 ± 0.24 m a-1 during the periods 1982-96 and 1996-2009, respectively. The thinning rate increases down-glacier, reaching a magnitude up to -1.8 m a-1 near the terminus from 1996 to 2009. The ice velocity has reduced by >70% from 1982 to 2009 in the lower half of the glacier. By assuming a constant driving stress over the glacier, the total ice volume in 2009 was estimated as 0.061 km3. Our results indicate that Yala Glacier has lost ∼40% of its ice volume over the last 27 years and that the rate of the mass loss has accelerated over the last decade.
Spittal place-names in Menteith and Strathendrick: evidence of crusading endowments?
Authors: McNiven Peter
Published: July 2013

Much discussion on the place-name element spittal has focused on its use as an indication of the location of a medieval hospital, lands belonging to such a hospital, or, in remote places, to the location of an inn or hostel. This paper argues that there is an overlooked dimension to spittal place-names, namely that some of them are properties belonging to the Knights Hospitaller, one of the crusading orders founded to protect the crusade routes to Jerusalem in the twelfth century. There is a large cluster of spittal-names in the earldom of Lennox, particularly in Strathendrick, and the evidence points to their being properties of the Hospitallers or their fellow crusading order, the Knights Templar. The Templars were suppressed in 1312 and many of their possessions were transferred to the Hospitallers. It is likely that these spittal-names in the Lennox are in fact crusading endowments, given perhaps by the earls of Lennox or the bishops of Glasgow.
Occurrence and Distribution of Synthetic Organic Substances in Boreal Coniferous Forest Soils Fertilized with Hygienized Municipal Sewage Sludge
Authors: Lindberg Richard , Sahlén Kenneth , Tysklind Mats
Published: July 2013

The occurrence and distribution of synthetic organic substances following application of dried and granulated (hygienized) municipal sewage sludge in Swedish boreal coniferous forests were investigated. Elevated concentrations of triclosan (TCS), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs) were detected in the humus layer. Concentrations of ethinyl estradiol (EE2), norfloxacin, ciprofloxacin, ofloxacin (FQs), and polyaromatic hydrocarbons (PAHs) were not significantly influenced. Maximum concentrations in humus were as follows (in ng/g dry matter): TCS; 778; PBDEs; 25; and PCB7; 16.7. Fertilization did not alter the levels of the substances in mineral soil, ground water, and various types of samples related to air. Further research within this area is needed, including ecotoxicological effects and fate, in order to improve the knowledge regarding the use of sludge as a fertilizing agent. Continuous annual monitoring, with respect to sampling and analysis, should be conducted on the already-fertilized fields.
Antioxidant, Iron Chelating and Tyrosinase Inhibitory Activities of Extracts from Talinum triangulare Leach Stem
Authors: Oliveira Amorim Ana , Campos de Oliveira Márcia , De Azevedo Amorim Thiago , Echevarria Aurea
Published: July 2013

The aim of this work is to evaluate the antioxidant activity against the radical species DPPH, the reducing capacity against Fe II ions, and the inhibitory activity on the tyrosinase enzyme of the T. triangulare. Hydromethanolic crude extract provided two fractions after the liquid/liquid partition with chloroform. The Folin-Ciocalteu method determined the total phenolic content of the crude extract (CE) and the hydromethanolic fraction (Fraction 1), resulting in a concentration of 0.5853 g/100 g for Fraction 1, and 0.1400 g/100 g for the CE. Taking into account the results of the DPPH, the free radical scavenging capacity was confirmed. The formation of complexes with Fe II ions was evaluated by UV/visible spectrometry; results showed that CE has complexing power similar to the positive control (Gingko biloba extract).The inhibitory capacity of samples against the tyrosinase enzyme was determined by the oxidation of L-DOPA, providing IC50 values of 13.3 μg·mL−1 (CE) and 6.6 μg·mL−1 (Fraction 1). The values indicate that Fraction 1 was more active and showed a higher inhibitory power on the tyrosinase enzyme than the ascorbic acid, used as positive control. The hydromethanolic extract of T. triangulare proved to have powerful antioxidant activity and to inhibit the tyrosinase enzyme; its potential is increased after the partition with chloroform.
Protection Intensity Evaluation for a Security System Based on Entropy Theory
Authors: Lv Haitao , Hu Ruimin , Chen Jun , He Zheng , Chen Shihong
Published: July 2013

The protection effectiveness is an important metric to judge whether a security system is good or not. In this paper, a security system deployed in a guard field is regarded abstractly as a security network. A quantitative protection effectiveness evaluation method based on entropy theory is introduced. We propose the protection intensity model, which can be used to calculate the protection intensity of a stationary or moving object provided by a security system or a security network. Using the protection intensity model, an algorithm, specifically for finding the minimal protection intensity paths of a field deployed multiple security system, is also put forward. The minimal protection intensity paths can be considered as the effectiveness measure of security networks. Finally, we present the simulation of the methods and models in this paper.
Optimization of a Fuzzy-Logic-Control-Based Five-Stage Battery Charger Using a Fuzzy-Based Taguchi Method
Authors: Liu Chun-Liang , Chiu Yi-Shun , Liu Yi-Hua , Ho Yeh-Hsiang , Huang Shu-Syuan
Published: July 2013

Lithium ion (Li-ion) batteries have been widely used in various kinds of applications, including consumer electronics, green energy systems and electrical vehicles. Since the charging method has a significant influence on the performance and lifetime of Li-ion batteries, an intelligent charging algorithm which can properly determine the charging current is essential. In this study, a fuzzy-logic-control-based (FLC-based) five-stage Li-ion battery charger is proposed. The proposed charger takes the temperature rise and the gradient of temperature rise of battery into account, and adjusts the charging current accordingly. To further improve the performance of the proposed FLC, the fuzzy-based Taguchi method is utilized to determine the optimal output membership functions (MFs). Comparing with the conventional constant current-constant voltage (CC-CV) method, the charging time, charging efficiency, average temperature rise and the obtained cycle life of the Li-ion battery are improved by about 58.3%, 1.65%, 26.7% and 59.3%, respectively.
Foliage and Litter Chemistry, Decomposition, and Nutrient Release in Pinus taeda
Authors: Kiser L. , Fox Thomas , Carlson Colleen
Published: July 2013

Following fertilization of forest plantations, high accumulations of nutrients in the forest floor creates the need to assess rates of forest floor decomposition and nutrient release. The study site was a 25-year old experimental loblolly pine plantation in the North Carolina Sandhills Region. Soluble and insoluble N, P, carbohydrate and phenol-tannin fractions were determined in foliage and litter by extraction with trichloroacetic acid. The long-term forest floor decomposition rate and decomposition and nutrient release in an experiment simulating removal of the overstory canopy were also determined. In litter, insoluble protein-N comprised 80%–90% of total-N concentration while soluble inorganic- and organic-P comprised 50%–75% of total-P concentration explaining forest floor N accumulations. Fertilization did not increase soluble carbohydrates in litter and forest floor decomposition rates. Loblolly pine forest floor decomposing in environmental conditions simulating removal of the overstory canopy was greatly accelerated and indicated 75% mass loss and release of 80% of the N pool within one year. This could result in a loss of substantial quantities of N at harvest due to low N uptake by seedlings in the newly planted next rotation suggesting management of the forest floor at harvest is essential to conserve site N capital in these N limited systems.
Ectopic Expression of BraYAB1-702, a Member of YABBY Gene Family in Chinese Cabbage, Causes Leaf Curling, Inhibition of Development of Shoot Apical Meristem and Flowering Stage Delaying in Arabidopsis thaliana
Authors: Zhang Xin-Ling , Yang Ze-Ping , Zhang Jing , Zhang Lu-Gang
Published: July 2013

YABBY gene family plays an important role in the polarity development of lateral organs. We isolated the BraYAB1-702 gene, a member of the YABBY gene family, from young leaves of Chinese cabbage line 06J45. The full-length gene has a 937 bp CDNA sequence and contains an open reading frame (ORF) of 702 bp. The subcellular localization analysis showed that the expression product of the gene was localized in the nucleus. Ectopic expression of BraYAB1-702 in Arabidopsis thaliana caused leaf curling from the adaxial epidermises to abaxial epidermises; the partial abaxialization of the adaxial epidermises of leaves; leaf trichomes and stomata numbers being significantly increased; the plants being severely stunted; the flowering stage being remarkably delayed and inhibiting the development of shoot apical meristem (SAM) with the down-regulation of the expression of SHOOT MERISTEMLESS (STM), Brevipedicellus (BP) and KNAT2 which were related to the development of shoot apical meristem. These results from the present research help to reveal the molecular mechanism of BraYAB1-702 gene in the establishment of adaxial–abaxial polarity of the lateral organs in Chinese cabbage.
Structure Prediction of Partial-Length Protein Sequences
Authors: Laurenzi Adrian , Hung Ling-Hong , Samudrala Ram
Published: July 2013

Protein structure information is essential to understand protein function. Computational methods to accurately predict protein structure from the sequence have primarily been evaluated on protein sequences representing full-length native proteins. Here, we demonstrate that top-performing structure prediction methods can accurately predict the partial structures of proteins encoded by sequences that contain approximately 50% or more of the full-length protein sequence. We hypothesize that structure prediction may be useful for predicting functions of proteins whose corresponding genes are mapped expressed sequence tags (ESTs) that encode partial-length amino acid sequences. Additionally, we identify a confidence score representing the quality of a predicted structure as a useful means of predicting the likelihood that an arbitrary polypeptide sequence represents a portion of a foldable protein sequence (“foldability”). This work has ramifications for the prediction of protein structure with limited or noisy sequence information, as well as genome annotation.
Plant Flavonoids—Biosynthesis, Transport and Involvement in Stress Responses
Authors: Petrussa Elisa , Braidot Enrico , Zancani Marco , Peresson Carlo , Bertolini Alberto , Patui Sonia , Vianello Angelo
Published: July 2013

This paper aims at analysing the synthesis of flavonoids, their import and export in plant cell compartments, as well as their involvement in the response to stress, with particular reference to grapevine (Vitis vinifera L.). A multidrug and toxic compound extrusion (MATE) as well as ABC transporters have been demonstrated in the tonoplast of grape berry, where they perform a flavonoid transport. The involvement of a glutathione S-transferase (GST) gene has also been inferred. Recently, a putative flavonoid carrier, similar to mammalian bilitranslocase (BTL), has been identified in both grape berry skin and pulp. In skin the pattern of BTL expression increases from véraison to harvest, while in the pulp its expression reaches the maximum at the early ripening stage. Moreover, the presence of BTL in vascular bundles suggests its participation in long distance transport of flavonoids. In addition, the presence of a vesicular trafficking in plants responsible for flavonoid transport is discussed. Finally, the involvement of flavonoids in the response to stress is described.
The Non-Photosynthetic Algae Helicosporidium spp.: Emergence of a Novel Group of Insect Pathogens
Authors: Tartar Aurélien
Published: July 2013

Since the original description of Helicosporidium parasiticum in 1921, members of the genus Helicosporidium have been reported to infect a wide variety of invertebrates, but their characterization has remained dependent on occasional reports of infection. Recently, several new Helicosporidium isolates have been successfully maintained in axenic cultures. The ability to produce large quantity of biological material has led to very significant advances in the understanding of Helicosporidium biology and its interactions with insect hosts. In particular, the unique infectious process has been well documented; the highly characteristic cyst and its included filamentous cell have been shown to play a central role during host infection and have been the focus of detailed morphological and developmental studies. In addition, phylogenetic analyses inferred from a multitude of molecular sequences have demonstrated that Helicosporidium are highly specialized non-photosynthetic algae (Chlorophyta: Trebouxiophyceae), and represent the first described entomopathogenic algae. This review provides an overview of (i) the morphology of Helicosporidium cell types, (ii) the Helicosporidium life cycle, including the entire infectious sequence and its impact on insect hosts, (iii) the phylogenetic analyses that have prompted the taxonomic classification of Helicosporidium as green algae, and (iv) the documented host range for this novel group of entomopathogens.
“Just Caring”: Can We Afford the Ethical and Economic Costs of Circumventing Cancer Drug Resistance?
Authors: Fleck Leonard
Published: July 2013

Personalized medicine has been presented in public and professional contexts in excessively optimistic tones. In the area of cancer what has become clear is the extraordinary heterogeneity and resilience of tumors in the face of numerous targeted therapies. This is the problem of cancer drug resistance. I summarize this problem in the first part of this essay. I then place this problem in the context of the larger political economic problem of escalating health care costs in both the EU and the US. In turn, that needs to be placed within an ethical context: How should we fairly distribute access to needed health care for an enormous range of health care needs when we have only limited resources (money) to meet virtually unlimited health care needs (cancer and everything else)? This is the problem of health care rationing. It is inescapable as a moral problem and requires a just resolution. Ultimately that resolution must be forged through a process of rational democratic deliberation.
Polymeric Materials Reinforced with Multiwall Carbon Nanotubes: A Constitutive Material Model
Authors: Córdova René , Elías-Zúiga Alex , Elizalde Luis , Siller Héctor , Sánchez José , Rodríguez Ciro , Ortega Wendy
Published: July 2013

In this paper we have modified an existing material model introduced by Cantournet and co-workers to take into account softening and residual strain effects observed in polymeric materials reinforced with carbon nanotubes when subjected to loading and unloading cycles. In order to assess the accuracy of the modified material model, we have compared theoretical predictions with uniaxial extension experimental data obtained from reinforced polymeric material samples. It is shown that the proposed model follows experimental data well as its maximum errors attained are lower than 2.67%, 3.66%, 7.11% and 6.20% for brominated isobutylene and paramethylstyrene copolymer reinforced with multiwall carbon nanotubes (BIMSM-MWCNT), reinforced natural rubber (NR-MWCNT), polybutadiene-carbon black (PB-CB), and PC/ABS reinforced with single-wall carbon nanotubes (SWCNT), respectively.
In Vivo Osteogenic Differentiation of Human Embryoid Bodies in an Injectable in Situ-Forming Hydrogel
Authors: Kim Da , Kim Yoon , Lee Hai , Moon Shin , Ku Seung-Yup , Kim Moon
Published: July 2013

In this study, we examined the in vivo osteogenic differentiation of human embryoid bodies (hEBs) by using an injectable in situ-forming hydrogel. A solution containing MPEG-b-(polycaprolactone-ran-polylactide) (MCL) and hEBs was easily prepared at room temperature. The MCL solution with hEBs and osteogenic factors was injected into nude mice and developed into in situ-forming hydrogels at the injection sites; these hydrogels maintained their shape even after 12 weeks in vivo, thereby indicating that the in situ-forming MCL hydrogel was a suitable scaffold for hEBs. The in vivo osteogenic differentiation was observed only in the in situ gel-forming MCL hydrogel in the presence of hEBs and osteogenic factors. In conclusion, this preliminary study suggests that hEBs and osteogenic factors embedded in an in situ-forming MCL hydrogel may provide numerous benefits as a noninvasive alternative for allogeneic tissue engineering applications.
Formation of Tunable, Emulsion Micro-Droplets Utilizing Flow-Focusing Channels and a Normally-Closed Micro-Valve
Authors: Wang Jung-Hao , Lee Gwo-Bin
Published: July 2013

A mono-dispersed emulsion is of great significance in many chemical, biomedical and industrial applications. The current study reports a new microfluidic chip capable of forming tunable micro-droplets in liquids for emulsification applications. It can precisely generate size-tunable, uniform droplets using flow-focusing channels and a normally-closed valve, which is opened by a pneumatic suction force. Experimental data showed that micro-droplets with a diameter ranging from several to tens of micrometers could be precisely generated with a high uniformity. The droplet size is experimentally found to be dependent on the velocity of the dispersed-phase liquid, which is controlled by the deflection of the suction membrane. Emulsions with droplet sizes ranging from 5.5 to 55 μm are successfully observed. The variation in droplet sizes is from 3.8% to 2.5%. The micro-droplets have a uniform size and droplets smaller than those reported in previous studies are possible with this approach. This new microfluidic device can be promising for emulsification and other related applications.
Factors Influencing the Antifolate Activity of Synthetic Tea-Derived Catechins
Authors: Sáez-Ayala Magalí , Fernández-Pérez María , Chazarra Soledad , Mchedlishvili Nani , Tárraga-Tomás Alberto , Rodríguez-López José
Published: July 2013

Novel tea catechin derivatives have been synthesized, and a structure-activity study, related to the capacity of these and other polyphenols to bind dihydrofolate reductase (DHFR), has been performed. The data showed an effective binding between all molecules and the free enzyme, and the dissociation constants of the synthetic compounds and of the natural analogues were on the same order. Polyphenols with a catechin configuration were better DHFR inhibitors than those with an epicatechin configuration. Antiproliferative activity was also studied in cultured tumour cells, and the data showed that the activity of the novel derivatives was higher in catechin isomers. Derivatives with a hydroxyl group para on the ester-bonded gallate moiety presented a high in vitro binding to DHFR, but exhibited transport problems in cell culture due to ionization at physiologic pHs. The impact of the binding of catechins to serum albumin on their biological activity was also evaluated. The information provided in this study could be important for the design of novel medicinal active compounds derived from tea catechins. The data suggest that changes in their structure to avoid serum albumin interactions and to facilitate plasmatic membrane transport are essential for the intracellular functions of catechins.
HPLC Analysis of Phenolics Compounds and Antioxidant Capacity of Leaves of Vitex megapotamica (Sprengel) Moldenke
Authors: De Brum Thiele , Zadra Marina , Piana Mariana , Boligon Aline , Fröhlich Janaina , De Freitas Robson , Stefanello Sílvio , Froeder Amanda , Belke Bianca , Nunes Letícia , Da Silva Jesus Roberta , Machado Michel , Teixeira da Rocha João , Soares Félix , Athayde Margareth
Published: July 2013

Vitex megapotamica (Sprengel) Moldenke belongs to the Verbenaceae family and is popularly known as “tarumã”. The antioxidant capacity of fractions and crude extract from the leaves of V. megapotamica were determined in this study through the capacity to remove reactive species and phenolic compounds were quantified in the various fractions. The IC50 (DPPH) ranged from 14.17 ± 0.76 to 37.63 ± 0.98 µg/mL. The ethyl acetate fraction might contain the strongest lipid peroxidation inhibitory compounds with an IC50 of 16.36 ± 5.09 µg/mL, being also the one with the highest content of polyphenols (522.4 ± 1.12 mg/g), flavonoids (220.48 ± 0.30 mg/g) and condensed tannins (3.86 ± 0.53 mg/g). Compounds quantified by HPLC/DAD in the crude extract and fractions were chlorogenic and rosmarinic acids. Higher dosages of the extracts were more effective in reducing levels of plasma protein carbonyls and were also shown to be able to remove reactive species by a 2',7'-dichlorofluorescein diacetate assay, reducing oxidative stress in all tested fractions. Results obtained indicated that V. megapotamica exhibits good potential to prevent diseases caused by the overproduction of free radicals and it might also be used as a potential source of natural antioxidant agents.
Thermal Behavior of Pinan-2-ol and Linalool
Authors: Leiner Janne , Stolle Achim , Ondruschka Bernd , Netscher Thomas , Bonrath Werner
Published: July 2013

Linalool is an important intermediate for syntheses of isoprenoid fragrance compounds and vitamins A and E. One process option for its production is the thermal gas-phase isomerization of cis- and trans-pinan-2-ol. Investigations of this reaction were performed in a flow-type apparatus in a temperature range from 350–600 °C and a residence time range of 0.6–0.8 s. Rearrangement of the bicyclic alcohol led to linalool, plinols arising from consecutive reactions of linalool and other side products. Effects of residence time, temperature, surface-to-volume-ratio, carrier gas, and the presence of additives on yield and selectivity were studied. Furthermore, the effects of such parameters on ene-cyclization of linalool affording plinols were investigated. Results indicate that manipulation of the reaction in order to affect selectivity is difficult due to the large free path length to other molecules in the gas phase. However, conditions have been identified allowing one to increase the selectivity and the yield of linalool throughout pyrolysis of pinan-2-ol.
Distinct Metabolites for Photoreactive l-Phenylalanine Derivatives in Klebsiella sp. CK6 Isolated from Rhizosphere of a Wild Dipterocarp Sapling
Authors: Wang Lei , Hisano Wataru , Murai Yuta , Sakurai Munenori , Muto Yasuyuki , Ikemoto Haruka , Okamoto Masashi , Murotani Takashi , Isoda Reika , Kim Dongyeop , Sakihama Yasuko , Sitepu Irnayuli , Hashidoko Yasuyuki , Hatanaka Yasumaru , Hashimoto Makoto
Published: July 2013

Photoaffinity labeling is a reliable analytical method for biological functional analysis. Three major photophores—aryl azide, benzophenone and trifluoromethyldiazirine—are utilized in analysis. Photophore-bearing l-phenylalanine derivatives, which are used for biological functional analysis, were inoculated into a Klebsiella sp. isolated from the rhizosphere of a wild dipterocarp sapling in Central Kalimantan, Indonesia, under nitrogen-limiting conditions. The proportions of metabolites were quite distinct for each photophore. These results indicated that photophores affected substrate recognition in rhizobacterial metabolic pathways, and differential photoaffinity labeling could be achieved using different photophore-containing l-phenylalanine derivatives.
Characterization of Flavonoids and Phenolic Acids in Myrcia bella Cambess. Using FIA-ESI-IT-MSn and HPLC-PAD-ESI-IT-MS Combined with NMR
Authors: Saldanha Luiz , Vilegas Wagner , Dokkedal Anne
Published: July 2013

The leaves of Myrcia DC. ex Guill species are used in traditional medicine and are also exploited commercially as herbal drugs for the treatment of diabetes mellitus. The present work aimed to assess the qualitative and quantitative profiles of M. bella hydroalcoholic extract, due to these uses, since the existing legislation in Brazil determines that a standard method must be developed in order to be used for quality control of raw plant materials. The current study identified eleven known flavonoid-O-glycosides and six acylated flavonoid derivatives of myricetin and quercetin, together with two kaempferol glycosides and phenolic acids such as caffeic acid, ethil galate, gallic acid and quinic acid. In total, 24 constituents were characterized, by means of extensive preparative chromatographic analyses, along with MS and NMR techniques. An HPLC-PAD-ESI-IT-MS and FIA-ESI-IT-MSn method were developed for rapid identification of acylated flavonoids, flavonoid-O-glycosides derivatives of myricetin and quercetin and phenolic acids in the hydroalcoholic M. bella leaves extract. The FIA-ESI-IT-MS techinique is a powerful tool for direct and rapid identification of the constituents after isolation and NMR characterization. Thus, it could be used as an initial method for identification of authentic samples concerning quality control of Myrcia spp extracts.
Characterization of Water Extractable Arabinoxylans from a Spring Wheat Flour: Rheological Properties and Microstructure
Authors: Morales-Ortega Adriana , Carvajal-Millan Elizabeth , López-Franco Yolanda , Rascón-Chu Agustín , Lizardi-Mendoza Jaime , Torres-Chavez Patricia , Campa-Mada Alma
Published: July 2013

In the present study water extractable arabinoxylans (WEAX) from a Mexican spring wheat flour (cv. Tacupeto F2001) were isolated, characterized and gelled and the gel rheological properties and microstructure were investigated. These WEAX presented an arabinose to xylose ratio of 0.66, a ferulic acid and diferulic acid content of 0.526 and 0.036 µg/mg WEAX, respectively and a Fourier Transform Infra-Red (FT-IR) spectrum typical of arabinoxylans. The intrinsic viscosity and viscosimetric molecular weight values for WEAX were 3.5 dL/g and 504 kDa, respectively. WEAX solution at 2% (w/v) formed gels induced by a laccase as cross-linking agent. Cured WEAX gels registered storage (G’) and loss (G’’) modulus values of 31 and 5 Pa, respectively and a diferulic acid content of 0.12 µg/mg WEAX, only traces of triferulic acid were detected. Scanning electron microscopy analysis of the lyophilized WEAX gels showed that this material resembles that of an imperfect honeycomb.
Dendrimers in Layer-by-Layer Assemblies: Synthesis and Applications
Authors: Sato Katsuhiko , Anzai Jun-ichi
Published: July 2013

We review the synthesis of dendrimer-containing layer-by-layer (LbL) assemblies and their applications, including biosensing, controlled drug release, and bio-imaging. Dendrimers can be built into LbL films and microcapsules by alternating deposition of dendrimers and counter polymers on the surface of flat substrates and colloidal microparticles through electrostatic bonding, hydrogen bonding, covalent bonding, and biological affinity. Dendrimer-containing LbL assemblies have been used to construct biosensors, in which electron transfer mediators and metal nanoparticles are often coupled with dendrimers. Enzymes have been successfully immobilized on the surface of electrochemical and optical transducers by forming enzyme/dendrimer LbL multilayers. In this way, high-performance enzyme sensors are fabricated. In addition, dendrimer LbL films and microcapsules are useful for constructing drug delivery systems because dendrimers bind drugs to form inclusion complexes or the dendrimer surface is covalently modified with drugs. Magnetic resonance imaging of cancer cells by iron oxide nanoparticles coated with dendrimer LbL film is also discussed.
Theory of Carbon Nanotube (CNT)-Based Electron Field Emitters
Authors: Bocharov Grigory , Eletskii Alexander
Published: July 2013

Theoretical problems arising in connection with development and operation of electron field emitters on the basis of carbon nanotubes are reviewed. The physical aspects of electron field emission that underlie the unique emission properties of carbon nanotubes (CNTs) are considered. Physical effects and phenomena affecting the emission characteristics of CNT cathodes are analyzed. Effects given particular attention include: the electric field amplification near a CNT tip with taking into account the shape of the tip, the deviation from the vertical orientation of nanotubes and electrical field-induced alignment of those; electric field screening by neighboring nanotubes; statistical spread of the parameters of the individual CNTs comprising the cathode; the thermal effects resulting in degradation of nanotubes during emission. Simultaneous consideration of the above-listed effects permitted the development of the optimization procedure for CNT array in terms of the maximum reachable emission current density. In accordance with this procedure, the optimum inter-tube distance in the array depends on the region of the external voltage applied. The phenomenon of self-misalignment of nanotubes in an array has been predicted and analyzed in terms of the recent experiments performed. A mechanism of degradation of CNT-based electron field emitters has been analyzed consisting of the bombardment of the emitters by ions formed as a result of electron impact ionization of the residual gas molecules.