bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of IL‐10‐producing regulatory B cells in control of cerebral malaria in Plasmodium berghei infected mice
Authors: Liu Yunfeng , Chen Yue , Li Zhaotao , Han Yingli , Sun Yanxia , Wang Qiong , Liu Boyu , Su Zhong
Published: July 2013

Cerebral malaria (CM) is a neurological syndrome often occurring in severe malaria. Although CM is known as an immunopathology in brain tissue mediated by excessive proinflammatory cytokines, the immunoregulatory mechanism is poorly understood. Here, we investigated the role of IL‐10‐producing regulatory B (Breg) cells in modulating CM development in a murine model of Plasmodium berghei ANKA infection. We observed that blood‐stage P. berghei induced expansion of IL‐10‐producing Breg cells in C57BL/6 mice. Adoptive transfer of IL‐10+ Breg cells to P. berghei infected mice significantly reduced the accumulation of NK and CD8+ T cells and hemorrhage in brain tissue, and improved the survival of the mice compared with control groups, although parasitemia levels were not altered. Treatment of Breg‐cell recipient mice with anti‐IL‐10 receptor mAb blocked the protective effect of Breg cells. Adoptive transfer of CD4+CD25+ Treg cells failed to prevent CM in infected mice. Spleen cells from Breg‐cell recipient mice produced increased levels of IL‐10 in vitro. Cell co‐culture showed that purified IL‐10+ B cells, but not IL‐10− B cells, promoted IL‐10 production by CD4+ T cells. These results demonstrate that IL‐10‐producing Breg cells may represent an important mechanism for controlling the immunopathology and prevention of CM associated with P. berghei infection.
Tris(cyclometalated) Iridium(III) Phosphorescent Complexes with 2‐Phenylthiazole‐Type Ligands: Synthesis, Photophysical, Redox and Electrophosphorescent Behavior
Authors: Yao Chunliang , Jiao Bo , Yang Xiaolong , Xu Xianbin , Dang Jingshuang , Zhou Guijiang , Wu Zhaoxin , Lv Xingqiang , Zeng Yi , Wong Wai‐Yeung
Published: July 2013

Tris(cyclometalated) iridium(III) phosphorescent emitters with 2‐phenylthiazole‐type ligands have been designed and synthesized. Their photophysical properties, electrochemical behavior and electroluminescent (EL) performance can be influenced by introducing fluorine atoms to the phenyl moiety of the thiazole‐based ligands. The phosphorescent emission maxima can be shifted from 546 nm to 517 nm by increasing the number of the fluorine atoms attached to the ligands of the iridium(III) complexes. Furthermore, the HOMO levels for these phosphorescent complexes exhibit a gradual decrease from –5.28 eV to –5.59 eV with the introduction of fluorine atoms. Owing to the character of their electronic structures, the phosphorescent emitters are preferentially excited by means of a host‐guest energy‐transfer process in the organic light‐emitting diodes (OLEDs). Accordingly, their EL performance is strictly restricted by the triplet energy level difference between the phosphorescent dopant and the host materials. The thiazole‐based cyclometalated iridium(III) triplet emitters can exhibit maximum EL efficiencies with ηext = 7.87 %, ηL = 23.62 cd A–1 and ηp = 13.46 lm W–1.
New biobased epoxy materials from cardanol
Authors: Jaillet Fanny , Darroman Emilie , Ratsimihety Amédée , Auvergne Rémi , Boutevin Bernard , Caillol Sylvain
Published: July 2013

Commercial epoxidized cardanol, from cashew nut shell liquid (CNSL), is a biobased epoxide reactant with interesting aromatic structure. Epoxidized cardanol was thoroughly analyzed using 1H and 13C NMR, size exclusion chromatography, and titration in order to determine the structure. This epoxidized cardanol was reacted with isophorone diamine and Jeffamine D400 diamine in order to synthesize epoxy networks. These epoxy networks, formulated in stoichiometry ratio, were characterized by differential scanning calorimetry, thermogravimetric analysis, dynamic mechanical analysis analyses and were compared to bisphenol A diglycidyl ether (DGEBA) network. Cardanol‐based epoxy materials exhibit interesting mechanical and thermal properties for coatings.

Practical application: The reactant described in this contribution, i.e. epoxidized cardanol from CNSL, provides biobased aromatic building blocks for further epoxy resin syntheses by reaction with amine hardeners. The obtained epoxy networks are partially biobased and may be applied as binders and coatings.
Solution Phase and Nanoparticular Biosynthetically Inspired Interconnections in the Canthin‐6‐one β‐Carboline Series and Study of Phenotypic Properties on C. elegans
Authors: Cebrián‐Torrejón Gerardo , Mackiewicz Nicolas , Vázquez‐Manrique Rafael P. , Fournet Alain , Figadère Bruno , Nicolas Julien , Poupon Erwan
Published: July 2013

Based on the biosynthetic line of canthin‐6‐one alkaloids from their simple precursors such as tryptamine, the present work is focused on the study of alternative protocol of the Bischler‐Napieralski reaction and has led to a full coverage of the different biosynthetic intermediates. Nanoparticles were also prepared as mimics of biosynthetic assembly lines and some interesting biological results in term of chemical ecology are also reported.
Efficient radio resource management algorithms in opportunistic cognitive radio networks
Authors: Bourdena Athina , Pallis Evangelos , Kormentzas Georgios , Mastorakis George
Published: July 2013

Cognitive radio (CR) bands following an interference‐free opportunistic manner. However, introduction of CR networks creates new challenges that are highly related to the fluctuation of TVWS, as they vary over time and location, as well as issues related to diverse Quality of Service requirements. In this context, this paper proposes two radio resource management (RRM) algorithms, enabling for the opportunistic exploitation of TVWS in a centralised CR networking architecture. Efficient administration of radio spectrum resources is achieved, by exploiting a novel RRM framework, adopted in a spectrum broker, which is in charge to effectively orchestrate the available wireless networking resources. Efficient RRM algorithms performance, as a matter of maximum‐possible spectrum broker benefit and radio spectrum utilisation, as well as minimum‐possible spectrum fragmentation is evaluated, by considering a fixed‐price and an auction‐based optimization approach. Experimental tests that were conducted under controlled simulation conditions, confirmed the validity of both RRM algorithms adopted in the proposed CR networking architecture, identifying fields for further research and experimentation. Copyright © 2013 John Wiley & Sons, Ltd.
Ecosystem‐scale measurements of biomass water using cosmic ray neutrons
Authors: Franz Trenton E. , Zreda Marek , Rosolem Rafael , Hornbuckle Brian K. , Irvin Samantha L. , Adams Henry , Kolb Thomas E. , Zweck Chris , Shuttleworth W. James
Published: July 2013

Accurate estimates of biomass are imperative for understanding the global carbon cycle. However, measurements of biomass and water in the biomass are difficult to obtain at a scale consistent with measurements of mass and energy transfer, ~1 km, leading to substantial uncertainty in dynamic global vegetation models. Here we use a novel cosmic ray neutron method to estimate a stoichiometric predictor of ecosystem‐scale biomass and biomass water equivalent over tens of hectares. We present two experimental studies, one in a ponderosa pine forest and the other in a maize field, where neutron‐derived estimates of biomass water equivalent are compared and found consistent with direct observations. Given the new hectometer scale of nondestructive observation and potential for continuous measurements, we anticipate this technique to be useful to many scientific disciplines.
Flexure of the India plate underneath the Bhutan Himalaya
Authors: Hammer Paul , Berthet Théo , Hetényi György , Cattin Rodolphe , Drukpa Dowchu , Chophel Jamyang , Lechmann Sarah , Moigne Nicolas Le , Champollion Cédric , Doerflinger Erik
Published: July 2013

We investigate flexural geometry and rheology of the India plate beneath the eastern Himalaya from a new gravity data set acquired in Bhutan. Compared to the well‒studied Nepal Himalaya, the obtained Bouguer anomaly profiles across the range show shorter wavelength flexure of the lithosphere with a narrower and shallower foreland basin. This new data set and seismic Moho constraints are interpreted together in terms of lithospheric flexure using a 2‒D thermomechanical model. Our results suggest that the strongest layer of the continental lithosphere beneath Bhutan is the upper mantle, as it is beneath Nepal. The observed west‒to‒east decrease in flexural wavelength is associated with weakening mantle rheology. The simulations show that this decrease can be related to ductile mantle behavior: either hydrated wet dunite or dry and hot olivine rheology. Both models display decoupled lithospheric layers leading to an eastward decrease of flexural rigidity from ∼1024 to ∼5·1022 N m in Nepal and Bhutan, respectively.
An evaluation of the potential radiative forcing and climatic impact of marine organic aerosols as heterogeneous ice nuclei
Authors: Yun Yuxing , Penner Joyce E.
Published: July 2013

Observational evidence demonstrates that marine organic aerosols (MOA) are able to act as ice nuclei. MOA explains a substantial portion of the submicron marine aerosol, so that they have the potential to effectively influence marine cloud microphysics and cloud radiative forcing. This study provides the first evaluation of the radiative forcing and climatic impact of marine organic aerosols as ice nuclei on a global scale. MOA is implemented into a coupled aerosol and general circulation model. It is found that MOA contributes to more ice formation than dust or black carbon/organic matter in mixed‐phase clouds. They also have a significant impact on the ice water path in the Southern Hemisphere and therefore could be an important missing source of ice nuclei in current models. The addition of MOA as natural heterogeneous ice nuclei reduces the magnitude of the total top‐of‐atmosphere anthropogenic aerosol forcing by as much as 0.3 W/m2.
Growth arrest and DNA damage 45G down-regulation contributes to janus kinase/signal transducer and activator of transcription 3 activation and cellular senescence evasion in hepatocellular carcinoma
Authors: Zhang Li , Yang Zhaojuan , Ma Aihui , Qu Yulan , Xia Suhua , Xu Dongxu , Ge Chao , Qiu Bijun , Xia Qiang , Li Jinjun , Liu Yongzhong
Published: July 2013

Growth arrest and DNA damage 45G (GADD45G), a stress sensor with multiple implications in various biological processes, is down-regulated in a broad spectrum of cancers. However, little is known about the biological effects of GADD45G on hepatocellular carcinoma (HCC) cells and the related mechanisms. In the present study, we found that GADD45G was commonly down-regulated in oncogene-transformed mouse liver cells and in human and mouse HCC. Ectopic expression of GADD45G robustly elicited senescence in HCC cells and suppressed tumor growth

in vivo

. Furthermore, GADD45G-induced senescence occurred in HCC cells independently of p53, p16INK4a (p16), and retinoblastoma (Rb). Instead, the prompt inhibition of Janus kinase 2 (Jak2), tyrosine kinase 2 (Tyk2), and signal transducer and activator of transcription 3 (Stat3) activation was observed in cells undergoing senescence. Impairment of Jak-Stat3 activation caused by GADD45G expression was associated with activation of SH2 domain-containing protein tyrosine phosphatase-2 (Shp2). Expression of constitutively activated Stat3 or human telomerase reverse transcriptase (hTERT), as well as knockdown of Shp2f, efficiently counteracted GADD45G-induced senescence. More important, in clinical HCC specimens, we found that GADD45G expression was inversely correlated with phosphorylated Stat3 expression in tumor cells and disease progression.

Conclusion :

GADD45G functions as a negative regulator of the Jak-Stat3 pathway and inhibits HCC by inducing cellular senescence. The decrease or absence of GADD45G expression may be a key event for tumor cells or premalignant liver cells to bypass cellular senescence.
Hepatitis C virus induced up-regulation of microRNA-27: A novel mechanism for hepatic steatosis
Authors: Singaravelu Ragunath , Chen Ran , Lyn Rodney K. , Jones Daniel M. , O'Hara Shifawn , Rouleau Yanouchka , Cheng Jenny , Srinivasan Prashanth , Nasheri Neda , Russell Rodney S. , Tyrrell Lorne D. , Pezacki John Paul
Published: July 2013

MicroRNAs (miRNAs) are small RNAs that posttranscriptionally regulate gene expression. Their aberrant expression is commonly linked with diseased states, including hepatitis C virus (HCV) infection. Herein, we demonstrate that HCV replication induces the expression of miR-27 in cell culture and

in vivo

HCV infectious models. Overexpression of the HCV proteins core and NS4B independently activates miR-27 expression. Furthermore, we establish that miR-27 overexpression in hepatocytes results in larger and more abundant lipid droplets, as observed by coherent anti-Stokes Raman scattering (CARS) microscopy. This hepatic lipid droplet accumulation coincides with miR-27b's repression of peroxisome proliferator-activated receptor (PPAR)-α and angiopoietin-like protein 3 (ANGPTL3), known regulators of triglyceride homeostasis. We further demonstrate that treatment with a PPAR-α agonist, bezafibrate, is able to reverse the miR-27b-induced lipid accumulation in Huh7 cells. This miR-27b-mediated repression of PPAR-α signaling represents a novel mechanism of HCV-induced hepatic steatosis. This link was further demonstrated

in vivo

through the correlation between miR-27b expression levels and hepatic lipid accumulation in HCV-infected SCID-beige/Alb-uPa mice.

Conclusion :

Collectively, our results highlight HCV's up-regulation of miR-27 expression as a novel mechanism contributing to the development of hepatic steatosis.
Intersubjective Experience of the Infant and Early Childhood Mental Health Consultant–Program Administrator Consultee Relationship
Authors: DeNatale Laura Mick
Published: July 2013

Infant and early childhood mental health consultation has emerged as one of the most common and effective strategies for supporting young children's socioemotional development. A key contributing factor for successful outcomes with this approach is the mental health consultant–consultee relationship. However, there have been no in‐depth qualitative studies to examine the intersubjective nature of the infant and early childhood mental health consultant–program administrator consultee relationship. In this study, 10 infant and early childhood mental health consultants and 15 program administrator consultees who worked together on the Erikson Institute–Illinois State Board of Education Infant and Early Childhood Mental Health Consultation Project were interviewed using qualitative, constructivist, grounded theory methodology. Results suggest that there are multiple internal and external factors that influence the consultant–administrator relationship, resulting in each relationship being a unique, co‐created relationship while sharing similar overall characteristics. Although the relationship can be challenging, especially for consultants during the engagement process, through repeated interactions with each other over an extended period of time, consultants and administrators increasingly experience the relationship to be positive and transformative. Similar to other studies on the early childhood mental health consultant–consultee relationship, it was found that there is a clear relationship between consultants’ and administrators’ perceptions of the relationship.
SCENARIO GENERATION FOR OPERATIONAL RISK
Authors: Mitra Sovan
Published: July 2013

Operational risk is an increasingly important area of risk management. Scenarios are an important modelling tool in operational risk management as alternative viable methods may not exist. This can be due to challenging modelling, data and implementation issues, and other methods fail to take into account expert information. The use of scenarios has been recommended by regulators; however, scenarios can be unreliable, unrealistic and fail to take into account quantitative data. These problems have also been identified by regulators such as Basel, and presently little literature exists on addressing the problem of generating scenarios for operational risk.

In this paper we propose a method for generating operational risk scenarios. We employ the method of cluster analysis to generate scenarios that enable one to combine expert opinion scenarios with quantitative operational risk data. We show that this scenario generation method leads to significantly improved scenarios and significant advantages for operational risk applications. In particular for operational risk modelling, our method leads to resolving the key problem of combining two sources of information without eliminating the information content gained from expert opinions, tractable computational implementation for operational risk modelling, improved stress testing, what‐if analyses and the ability to apply our method to a wide range of quantitative operational risk data (including multivariate distributions). We conduct numerical experiments on our method to demonstrate and validate its performance and compare it against scenarios generated from statistical property matching for comparison. Copyright © 2013 John Wiley & Sons, Ltd.
Imaging the noncentrosymmetric structural organization of tendon with Interferometric Second Harmonic Generation microscopy
Authors: Rivard Maxime , Popov Konstantin , Couture Charles‐André , Laliberté Mathieu , Bertrand‐Grenier Antony , Martin François , Pépin Henri , Pfeffer Christian P. , Brown Cameron , Ramunno Lora , Légaré François
Published: July 2013

We report the imaging of tendon with Interferometric Second Harmonic Generation microscopy. We observe that the noncentrosymmetric structural organization can be maintained along the fibrillar axis over more than 150 μm, while in the transverse direction it is ∼1–15 μm. Those results are explained by modeling tendon as a heterogeneous distribution of noncentrosymmetric nano‐cylinders (collagen fibrils) oriented along the fibrillar axis. The preservation of the noncentrosymmetric structural organization over multiple tens of microns reveals that tendon is made of domains in which the ratio between fibrils with positive and negative polarity is unbalanced. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoinduced partial unfolding of tubulin bound to meso‐tetrakis(sulfonatophenyl) porphyrin leads to inhibition of microtubule formation in vitro
Authors: McMicken Brady , Thomas Robert J. , Brancaleon Lorenzo
Published: July 2013

The irradiation of the complex formed by meso‐tetrakis (sulfonatophenyl) porphyrin (TSPP) and tubulin was investigated as well as its effects on the structure and function of the protein. We have used tubulin as a model target to investigate whether photoactive ligands docked to the protein can affect the structure and function of the protein upon exposure to visible light. We observed that laser irradiation prompts bleaching of the porphyrin which is accompanied by a sharp decrease (∼2 ns) in the average fluorescence lifetime of the protein and a change in the dichroic spectrum consistent with a decrease of helical structure. The result indicated the photoinduced partial unfolding of tubulin. We also observed that such partial conformational change inhibits the formation of microtubules in vitro. We investigated whether photosensitization of reactive oxygen species was responsible for these effects. Even upon removal of O2 the protein still undergoes conformational changes indicating that irradiation of the bound porphyrin does not require the presence of O2 to prompt conformational and functional effects opening the possibility that other mechanisms (e.g., charge transfer) are responsible for the photoinduced mechanism. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Intervals Between Bone Density Testing
Authors: Reid Ian R , Gamble Gregory D
Published: July 2013

There is a wide range of practices regarding times between bone density (BMD) measurements in osteopenic women. If decisions to treat osteoporosis are to be based on absolute fracture risk, then projections of fracture risk are a logical basis for determining appropriate intervals for BMD testing. Fracture risk depends mainly on age and BMD, and bone loss in older women is relatively constant at ∼1% annually, so it is possible to project fracture risk into the future and estimate when an individual's risk will approach the threshold for intervention. Modeling scenarios for a range of osteopenic baseline BMDs in 65-year-old women shows a remarkable consistency in the doubling time for Fracture Risk Assessment Tool (FRAX)-assessed fracture risk: 5 to 6 years. This estimate is of immediate relevance to clinical practice in that it can be used to determine how long to wait before reassessing BMD and fracture risk in women whose other risk factors are stable. © 2014 American Society for Bone and Mineral Research.
Regulation of Cellular Processes by Interleukin‐16 in Homeostasis and Cancer
Authors: Richmond Jillian , Tuzova Marina , Cruikshank William , Center David
Published: July 2013

Interleukin‐16 (IL‐16) is generated as a precursor molecule that is cleaved by caspase‐3 to produce a pro‐IL‐16 molecule that functions as a regulator of T cell growth, and a secreted peptide that functions as a CD4 and/or CD9 ligand for induction of cell motility and activation. IL‐16 has been predominantly studied as a contributing factor in the orchestration of an immune response; however, more recently IL‐16 bioactivity has been closely associated with the progression of a number of different cancers. While the association between IL‐16 plasma levels and tumor progression has been reported for many types of cancer, the mechanism for IL‐16 involvement has been partially elucidated for three of the cancer types, cutaneous T cell lymphoma (CTCL), multiple myeloma (MM), and breast cancer. The mechanism for promoting cell growth is different in each of these cancers and involves a sequence mutation in the pro‐molecule facilitating decreased p27KIP1 levels in CTCL; over expression of the secreted IL‐16 molecule to induce proliferation in CTCL T cells, and plasma cells in MM; and increased secreted IL‐16 acting to recruit CD4+ pro‐tumor macrophages in breast cancer. This article will review the cellular process for generating IL‐16, the biological activities for both the pro‐ and secreted forms of the protein, and then the mechanism by which these forms contribute to cancer progression. As a soluble cytokine the ability to reduce or eliminate IL‐16 synthesis through siRNA approaches or bioactivity through the use of neutralizing antibody treatment may represent a novel therapeutic approach. J. Cell. Physiol. 229: 139–147, 2014. © 2013 Wiley Periodicals, Inc.
An active ring fault detected at Tendürek volcano by using InSAR
Authors: Bathke H. , Sudhaus H. , Holohan E.P. , Walter T. R. , Shirzaei M.
Published: July 2013

Although ring faults are present at many ancient, deeply eroded volcanoes, they have been detected at only very few modern volcanic centers. At the so far little studied Tendürek volcano in eastern Turkey, we generated an ascending and a descending InSAR time series of its surface displacement field for the period from 2003 to 2010. We detected a large (~105 km2) region that underwent subsidence at the rate of ~1 cm/yr during this period. Source modeling results show that the observed signal fits best to simulations of a near‐horizontal contracting sill located at around 4.5 km below the volcano summit. Intriguingly, the residual displacement velocity field contains a steep gradient that systematically follows a system of arcuate fractures visible on the volcano's midflanks. RapidEye satellite optical images show that this fracture system has deflected Holocene lava flows, thus indicating its presence for at least several millennia. We interpret the arcuate fracture system as the surface expression of an inherited ring fault that has been slowly reactivated during the detected recent subsidence. These results show that volcano ring faults may not only slip rapidly during eruptive or intrusive phases, but also slowly during dormant phases.
On the time‐mean state of ocean models and the properties of long range acoustic propagation
Authors: Dushaw B. D. , Worcester P. F. , Dzieciuch M. A. , Menemenlis D.
Published: July 2013

Receptions on three vertical hydrophone arrays from basin‐scale acoustic transmissions in the North Pacific during 1996 and 1998 are used to test the time‐mean sound‐speed properties of the World Ocean Atlas 2005 (WOA05), of an eddying unconstrained simulation of the Parallel Ocean Program (POP), and of three data‐constrained solutions provided by the estimating the circulation and climate of the ocean (ECCO) project: a solution based on an approximate Kalman filter from the Jet Propulsion Laboratory (ECCO‐JPL), a solution based on the adjoint method from the Massachusetts Institute of Technology (ECCO‐MIT), and an eddying solution based on a Green's function approach from ECCO, Phase II (ECCO2). Predictions for arrival patterns using annual average WOA05 fields match observations to within small travel time offsets (0.3–1.0 s). Predictions for arrival patterns from the models differ substantially from the measured arrival patterns, from the WOA05 climatology, and from each other, both in terms of travel time and in the structure of the arrival patterns. The acoustic arrival patterns are sensitive to the vertical gradients of sound speed that govern acoustic propagation. Basin‐scale acoustic transmissions, therefore, provide stringent tests of the vertical temperature structure of ocean state estimates. This structure ultimately influences the mixing between the surface waters and the ocean interior. The relatively good agreement of the acoustic data with the more recent ECCO solutions indicates that numerical ocean models have reached a level of accuracy where the acoustic data can provide useful additional constraints for ocean state estimation.
Modal Bin Hybrid Model: A surface area consistent, triple‐moment sectional method for use in process‐oriented modeling of atmospheric aerosols
Authors: Kajino Mizuo , Easter Richard C. , Ghan Steven J.
Published: July 2013

A triple‐moment sectional (TMS) aerosol dynamics model, Modal Bin Hybrid Model (MBHM), has been developed. In addition to number and mass (volume), surface area is predicted (and preserved), which is important for aerosol processes and properties such as gas‐to‐particle mass transfer, heterogeneous reaction, and light extinction cross section. The performance of MBHM was evaluated against double‐moment sectional (DMS) models with coarse (BIN4) to very fine (BIN256) size resolutions for simulating evolution of particles under simultaneously occurring nucleation, condensation, and coagulation processes (BINx resolution uses x sections to cover the 1 nm to 1 µm size range). Because MBHM gives a physically consistent form of the intrasectional distributions, errors and biases of MBHM at BIN4‐8 resolution were almost equivalent to those of DMS at BIN16–32 resolution for various important variables such as the moments Mk (k: 0, 2, 3), dMk/dt, and the number and volume of particles larger than a certain diameter. Another important feature of MBHM is that only a single bin is adequate to simulate full aerosol dynamics for particles whose size distribution can be approximated by a single lognormal mode. This flexibility is useful for process‐oriented (multicategory and/or mixing state) modeling: Primary aerosols whose size parameters would not differ substantially in time and space can be expressed by a single or a small number of modes, whereas secondary aerosols whose size changes drastically from 1 to several hundred nanometers can be expressed by a number of modes. Added dimensions can be applied to MBHM to represent mixing state or photochemical age for aerosol mixing state studies.
Chemical and mineralogical trends during acid‐sulfate alteration of pyroclastic basalt at Cerro Negro volcano and implications for early Mars
Authors: McCollom Thomas M. , Hynek Brian M. , Rogers Karyn , Moskowitz Bruce , Berquó Thelma S.
Published: July 2013

Acid‐sulfate alteration of pyroclastic basalts in active fumaroles at Cerro Negro volcano, Nicaragua, was studied as a means to infer the mineralogical and chemical consequences of basalt alteration in analogous environments on early Mars. At this site, recently erupted basaltic cinders are undergoing alteration by SO2‐bearing steam. During alteration, silicate phenocrysts, including plagioclase, olivine, and augite, react much more rapidly than basaltic glass. Secondary mineralogy is dominated by a very limited number of phases that include amorphous silica, gypsum, Fe‐bearing natroalunite, and Fe‐oxides/oxyhydroxides, including hematite and magnetite. The major element chemistry of the deposits is controlled by two processes: gradual depletion of the major cations other than Si as the basalt components decompose and elements are mobilized out of the deposits, and enrichment in Ca and S from precipitation of gypsum, with Ca apparently supplied from sources below the surface. Reaction path models constrained by these observations but extrapolated to Martian conditions predict that alteration of pyroclastic deposits in similar environments on Mars should produce a secondary mineral assemblage that includes amorphous silica, Fe‐bearing natroalunite, anhydrite, kieserite, and hematite. Iron‐bearing natroalunite was found to produce a Mössbauer signal similar to that of jarosite, suggesting that this phase should be considered as an alternative to the jarosite component identified at Meridiani Planum. Spheroidal hematite formed in close association with natroalunite suggests a pathway for formation of hematite deposits on Mars.
Regolith production and transport at the Susquehanna Shale Hills Critical Zone Observatory, Part 2: Insights from meteoric 10Be
Authors: West Nicole , Kirby Eric , Bierman Paul , Slingerland Rudy , Ma Lin , Rood Dylan , Brantley Susan
Published: July 2013

Regolith‐mantled hillslopes are ubiquitous features of most temperate landscapes, and their morphology reflects the climatically, biologically, and tectonically mediated interplay between regolith production and downslope transport. Despite intensive research, few studies have quantified both of these mass fluxes in the same field site. Here we present an analysis of 87 meteoric 10Be measurements from regolith and bedrock within the Susquehanna Shale Hills Critical Zone Observatory (SSHO), in central Pennsylvania. Meteoric 10Be concentrations in bulk regolith samples (n = 73) decrease with regolith depth. Comparison of hillslope meteoric 10Be inventories with analyses of rock chip samples (n = 14) from a 24 m bedrock core confirms that >80% of the total inventory is retained in the regolith. The systematic downslope increase of meteoric 10Be inventories observed at SSHO is consistent with 10Be accumulation in slowly creeping regolith (~ 0.2 cm yr−1). Regolith flux inferred from meteoric 10Be varies linearly with topographic gradient (determined from high‐resolution light detection and ranging‐based topography) along the upper portions of hillslopes at SSHO. However, regolith flux appears to depend on the product of gradient and regolith depth where regolith is thick, near the base of hillslopes. Meteoric 10Be inventories at the north and south ridgetops indicate minimum regolith residence times of 10.5 ± 3.7 and 9.1 ± 2.9 ky, respectively, similar to residence times inferred from U‐series isotopes in Ma et al. (2013). The combination of our results with U‐series‐derived regolith production rates implies that regolith production and erosion rates are similar to within a factor of two on SSHO hillcrests.
Anatomy of sand beach ridges: Evidence from severe Tropical Cyclone Yasi and its predecessors, northeast Queensland, Australia
Authors: Nott Jonathan , Chague‐Goff Catherine , Goff James , Sloss Craig , Riggs Naomi
Published: July 2013

Four well‐identified tropical cyclones over the past century have been responsible for depositing distinct units of predominantly quartzose sand and gravel to form the most seaward beach ridge at several locations along the wet tropical coast of northeast Queensland, Australia. These units deposited by tropical cyclones display a key sedimentary signature characterized by a sharp basal erosional contact, a coarser grain size than the underlying facies and a coarse‐skewed trend toward the base. Coarse‐skewed distributions with minimal change in mean grain size also characterize the upper levels of the high‐energy deposited units at locations within the zone of maximum onshore winds during the tropical cyclone. These same coarse skew distributions are not apparent in sediments deposited at locations where predominantly offshore winds occurred during the cyclone, which in the case of northeast Australia is north of the eye‐crossing location. These sedimentary signatures, along with the geochemical indicators and the degraded nature of the microfossil assemblages, have proven to be useful proxies to identify storm‐deposited units within the study site and can also provide useful proxies in older beach ridges where advanced pedogenesis has obscured visual stratigraphic markers. As a consequence, more detailed long‐term histories of storms and tropical cyclones can now be developed.
Selected Scientific Topics of the 11th International Isotope Symposium on the Synthesis and Applications of Isotopes and Isotopically Labeled Compounds
Authors: Atzrodt Jens , Derdau Volker
Published: July 2013

This micro‐review describes hot topics and new trends in isotope science discussed at the 11th International Isotope Symposium on the Synthesis and Applications of Isotopes and Isotopically Labeled Compounds from a personal perspective. Copyright © 2013 John Wiley & Sons, Ltd.
Salicylaldehyde azine cluster formation observed by cold‐spray ionization mass spectrometry
Authors: Xu Xiangyu , Qiao Jinping , Deng Xuebin , Na Na , Ouyang Jin
Published: July 2013

We installed a cold‐spray ionization (CSI) source on a mass spectrometer to investigate the self‐assembly behavior of an aggregation‐induced emission enhancement system. Using a CSI source and the three‐dimensional platform, a self‐assembly system of a salicylaldehyde azine (SAA) was studied in mixture solution. This method permitted the determination of the structural information of the solution state, which cannot be detected by conventional mass spectrometry. In addition to the [M+H]+ ion (M is the SAA molecule), many major ion clusters such as [2M+Na]+ at m/z 503, [3M+Na]+ at m/z 743, [4M+Na]+ at m/z 983 and higher order aggregates were observed in the CSI mass spectra. However, many fragment ions, with the exception of cluster ions, appeared with high abundance when the ESI ion source was used due to the desolvation chamber temperature, suggesting that some aggregation can be detected at low temperatures. To investigate the effect of solvent on the aggregation, the CSI‐mass spectrometry (MS) experiments of SAA in absolute ethanol solution and ethanol/water (good/poor solvent) mixture solution were conducted. The most abundant ion peak was protonated SAA (m/z 241) in absolute ethanol, but many cluster ions and some multiple charged ion peaks were observed after adding a small amount of water into the ethanol solution. The results showed good agreement with that inferred by the combinational analysis of scanning electron microscope and fluorescence microscopy, indicating that CSI‐MS is capable of providing self‐assembly information of labile molecules in the solution state. Copyright © 2013 John Wiley & Sons, Ltd.
Rapid analysis of neurotransmitters in rat brain using ultra‐fast liquid chromatography and tandem mass spectrometry: application to a comparative study in normal and insomnic rats
Authors: He Bosai , Bi Kaishun , Jia Ying , Wang Jiahong , Lv Chunxiao , Liu Ran , Zhao Longshan , Xu Huarong , Chen Xiaohui , Li Qing
Published: July 2013

Neurotransmitters and their metabolites in central nervous system were known to play a significant role in sedation and hypnosis. A rapid and sensitive UFLC‐MS/MS method for simultaneous determination of serotonin, 5‐hydroxyindole acetic acid (5‐HIAA), tryptophan (Try), dopamine (DA), norepinephrine (NE), γ‐aminobutyric acid (GABA), glutamic acid (Glu) and acetylcholine (Ach) in rat brain without derivatization, ion‐pairing reagent or pre‐concentration was developed. Analytes and IS were separated on a Inertsil ODS‐EP column (150 mm × 4.6 mm, 5 µm particles) and analyzed in a single chromatographic run in less than 9.0 min, using gradient elution with the mobile phase consisting of methanol and 0.01% acetic acid in water at a flow rate of 1.2 ml min−1. The detection of the analytes was performed on 4000Q UFLC‐MS/MS system with turbo ion spray source in positive ion and multiple reaction monitoring mode. The developed method provided excellent linear calibration curves for the assay of analytes (R2 ≥ 0.9915). Limits of quantification were in the range of 1.0 ng ml−1 to 1.0 µg ml−1 for the analytes in rat brain. Intra‐ and inter‐day precision and accuracy of analytes were well within acceptance criteria (15%). Mean extraction recoveries of analytes and IS from rat brain were all more than 80.0%. Furthermore, the validated method was successfully applied to comparing profiles of analytes in normal and insomnic rat brains. Results indicated that there were statistically significant differences for serotonin, 5‐HIAA, DA, NE, Glu and Ach, but no significant difference for Try and GABA between two groups. Copyright © 2013 John Wiley & Sons, Ltd.
Group affective tone: A review and future research directions
Authors: Collins Amy L. , Lawrence Sandra A. , Troth Ashlea C. , Jordan Peter J.
Published: July 2013

Similarity in the experience of state affect is a common phenomenon for work team members and has been shown to have important consequences on team behavior and performance. We provide a comprehensive overview of the current state of research on group affective tone, including the development of group affective tone through affective convergence mechanisms, the conceptualization and operationalization of group affective tone, and the theoretical and practical consequences of positive and negative affective tones for group behavior and group performance. Finally, we highlight some emerging research directions that may provide promising avenues for future understanding of the complexity inherent in the formation and influence of state group affect. Copyright © 2013 John Wiley & Sons, Ltd.
Low‐Temperature Polymerization of ε‐Caprolactone Catalyzed by Cerium Triflates
Authors: Weidner Steffen M. , Scheliga Felix , Kricheldorf Hans R.
Published: July 2013

Using 22 metal triflates as catalysts, ε‐caprolactone is polymerized at 22 °C in bulk. Only five relatively acidic triflates prove active. Three triflates, including the neutral Sm3+, are active using water as initiator. A very low content of cyclics is found in all the experiments. With Ce3+ and Ce4+, polymerizations are performed in CH2Cl2 and in bulk at 2 °C and 22 °C. Low dispersities (down to 1.1) are obtained. At 22 °C, Ce4+ and, even better, Ce3+ also catalyze syntheses of CO2H‐ and CH2OH‐terminated polycaprolactones, whereby higher dispersities and larger fractions of cyclics are obtained. Further polymerizations and polycondensations are catalyzed with protic acids. The results can be explained by a proton‐catalyzed activated monomer mechanism.

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Tailoring Mechanical Properties of Isotactic Polypropylene Via Crystallization of the Mesophase and Control of Stereodefects Concentration
Authors: De Rosa Claudio , Auriemma Finizia , de Ballesteros Odda Ruiz , Di Girolamo Rocco , Tarallo Oreste , Galotto Nella Galotto
Published: July 2013

A strategy to tailor the properties of isotactic polypropylene, based on the combination of the crystallization of the mesophase and the control of the molecular structure and concentration of stereodefects via polymerization with metallocene catalysts, is presented. The mechanical properties can be modulated through the conventional slow crystallization from the melt in the α and γ forms, depending on the concentration of stereodefects, or the crystallization of the mesophase by melt quenching. The most stereoirregular sample with rr concentration of 11% shows elastic behavior either when it is slowly crystallized in the γ form or when it is crystallized in the mesomorphic form, but with remarkable differences in the values of the modulus and tensile strength.

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N‐Hydroxyphthalimide‐Mediated Oxidation of Styrene by Molecular Oxygen
Authors: Khan Ezaz Hasan , Pal Sunirmal , De Priyadarsi
Published: July 2013

In this work, the N‐hydroxyphthalimide (NHPI) is used for the oxidative polymerization of styrene at 25–100 psi oxygen pressure at 35–55 °C to obtain a faster rate of polymerization than in 2,2′‐azobisisobutyronitrile (AIBN)‐initiated polymerizations. The rates for oxidative polymerization are determined from the oxygen consumption (Δp) against time plots and NHPI shows a reaction rate increased several fold compared with AIBN. The kinetics of the oxidative polymerization reactions are studied at various concentrations of oxygen, NHPI, AIBN, and monomer. The polymerization rate of styrene is almost the same when the NHPI analogue, N‐hydroxysuccinimide (NHSI), is employed. A mechanism of oxidative polymerization in the presence of NHPI is suggested on the basis of the kinetic data and characterization results of poly(styrene peroxide) (PSP). The NHPI is efficient in initiation of the oxidative radical polymerization of styrene.

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Acridinediones: Effect of Substituents on Their Photoinitiating Abilities in Radical and Cationic Photopolymerization
Authors: Xiao Pu , Dumur Frédéric , Tehfe Mohamad‐Ali , Graff Bernadette , Gigmes Didier , Fouassier Jean Pierre , Lalevée Jacques
Published: July 2013

Ten acridinediones (ADs) with different substituents are prepared and investigated for their abilities to initiate a ring‐opening cationic photopolymerization in combination with an iodonium salt and N‐vinylcarbazole upon UV–vis light (Xe–Hg lamp; >330 nm) or visible light (halogen lamp) exposure. The structural effects in the ADs are outlined. The cationic and radical photopolymerization of an epoxide/acrylate blend in a one‐step hybrid cure very efficiently leads to the formation of an interpenetrated polymer network under UV–vis light or visible light irradiation (30 s for tack‐free coatings). The photochemical mechanisms are studied by molecular orbital calculations, steady‐state photolysis, electron spin resonance–spin trapping, cyclic voltammetry, fluorescence, and laser flash photolysis techniques.

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Blowing‐up solutions to two‐times fractional differential equations
Authors: Kirane Mokhtar , Kadem Abdelouhab , Debbouche Amar
Published: July 2013

Nonexistence results for a class of two‐times differential equations with fractional derivatives of orders between zero and one are presented. Furthermore, the result is extended to a two‐times system of two differential equations with fractional derivatives of orders between zero and one.
On semi‐classical d‐orthogonal polynomials
Authors: Saib Abdessadek
Published: July 2013

In this paper a general theory of semi‐classical d‐orthogonal polynomials is developed. We define the semi‐classical linear functionals by means of a distributional equation , where Φ and Ψ are matrix polynomials. Several characterizations for these semi‐classical functionals are given in terms of the corresponding d‐orthogonal polynomials sequence. They involve a quasi‐orthogonality property for their derivatives and some finite‐type relations.
Zeros of a family of hypergeometric para‐orthogonal polynomials on the unit circle
Authors: Dimitrov Dimitar K. , Ranga A. Sri
Published: July 2013

Para‐orthogonal polynomials derived from orthogonal polynomials on the unit circle are known to have all their zeros on the unit circle. In this note we study the zeros of a family of hypergeometric para‐orthogonal polynomials. As tools to study these polynomials, we obtain new results which can be considered as extensions of certain classical results associated with three term recurrence relations and differential equations satisfied by orthogonal polynomials on the real line. One of these results which might be considered as an extension of the classical Sturm comparison theorem, enables us to obtain monotonicity with respect to the parameters for the zeros of these para‐orthogonal polynomials. Finally, a monotonicity of the zeros of Meixner‐Pollaczek polynomials is proved.
Comparison theorems for self‐adjoint linear Hamiltonian eigenvalue problems
Authors: Hilscher Roman Šimon
Published: July 2013

In this work we derive new comparison results for (finite) eigenvalues of two self‐adjoint linear Hamiltonian eigenvalue problems. The coefficient matrices depend on the spectral parameter nonlinearly and the spectral parameter is present also in the boundary conditions. We do not impose any controllability or strict normality assumptions. Our method is based on a generalization of the Sturmian comparison theorem for such systems. The results are new even for the Dirichlet boundary conditions, for linear Hamiltonian systems depending linearly on the spectral parameter, and for Sturm–Liouville eigenvalue problems with nonlinear dependence on the spectral parameter.
Propargyl‐Functional Aliphatic Polycarbonate Obtained from Carbon Dioxide and Glycidyl Propargyl Ether
Authors: Hilf Jeannette , Frey Holger
Published: July 2013

The synthesis of propargyl‐functional poly(carbonate)s with different content of glycidyl propargyl ether (GPE) units is achieved via the copolymerization of propargyl glycidyl ether and carbon dioxide. A new type of functional poly(carbonate) synthesized directly from CO2 and the glycidyl ether is obtained. The resulting polymers show moderate polydispersities in the range of 1.6–2.5 and molecular weights in the range of 7000–10 500 g mol−1. The synthesized copolymers with varying number of alkyne functionalities and benzyl azide are used for the copper‐catalyzed Huisgen‐1,3‐dipolar addition. Moreover, the presence of vicinal alkyne groups opens a general pathway to produce functional aliphatic poly(carbonate)s from a single polymer scaffold.

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A modified free chimeric osteocutaneous fibular flap design for head and neck reconstruction: Experience on a series of 10 cases
Authors: Roan Tyng‐Luen , Chen Chien‐Chang , Yu Yen‐Chen , Hsieh Jung‐Hsien , Horng Shyue‐Yih , Tai Hao‐Chih , Cheng Nai‐Chen , Chien Hsiung‐Fei , Tang Yueh‐Bih
Published: July 2013

Background

We have previously described a modified chimeric fibular osteocutaneous flap design based on a combination of a traditional fibular flap and a peroneal artery perforator fasciocutaneous flap for mandible and adjacent soft tissue reconstruction. The purpose of this article is to share our experience with a larger case series utilizing this new technique for mandible and adjacent soft tissue reconstruction after cancer wide excision surgery and a more detailed description on these flaps harvesting procedures.

Patients and methods

Ten patients (age range from 32 to 63 years), who had segmental defect of mandible and adjacent soft tissue defect after cancer wide excision surgery, received mandible and adjacent soft tissue reconstruction based on the modified chimeric fibular flap design.

Results

The skin paddle based on peroneal perforators ranged from 9 cm × 3.5 cm to 10 cm × 10 cm and the mean pedicle length was 8.9 cm. Four patients underwent primary closure of the donor site. Three flap salvage procedures were performed due to vascular thrombosis and all flaps survived well. Nine patients had acceptable outer appearance, and one patient complained of cheek sunken. All patients had at least 3‐cm interincisor distance during a mean of 12‐month follow‐up period.

Conclusion

The modified chimeric osteocutaneous fibula flaps were feasible design with few intermuscular septum problems during bone fixation. Furthermore, it provided larger skin paddles with few restrictions to reconstruct the cheek skin defect. © 2013 Wiley Periodicals, Inc. Microsurgery 33:439–446, 2013.