bluuebunny/crossref_metadata_2025 huggingface dataset:
Notes on a methodological discussion: autobiography, critique and time
Authors: Løkken Gunvor
Published: December 2014

After having tried for some time to overview the contemporary field of qualitative research to give a lecture for a professorship in that area, my idea at the outset of writing this article was to address whether changes in qualitative research should be viewed as recurrent revolutions as highlighted by Denzin and Lincoln (2000; 2005), or as a field of continuing key themes and long-standing tensions, as conceptualized by Atkinson, Coffey and Delamont (2003). However, during my writing, after one detour into the May 2009 issue of Current Sociology and a second detour into the July 2009 issue of Qualitative Research, my attention focused on to how critical debate and review are displayed in different methodological positions of qualitative research. In my reading, the discussion in Current Sociology between main stream and postmodern methodological positioning revealed an utterly one-way feminist critique; this was also the case in one of three book reviews of The Handbook of Qualitative Research (Denzin and Lincoln, 2005) in the referred issue of Qualitative Research. My puzzle over this critical stance, and my third detour, into Yvonne Lincoln’s discussion of twenty-five years of qualitative and new paradigm research in the January 2010 Issue of Qualitative Inquiry, helped evolve the following notes on a methodological discussion. The notes are partly structured by a temporal narrative over personally lived qualitative research, and partly by an epistemological narrative of a methodological discussion, interwoven with the passing of time when writing.
‘Place’ as conceptual centre: a methodological focus on the bodily relations, movements and expressions of children up to three years of age in kindergarten
Authors: Hognestad Karin , Bøe Marit
Published: December 2014

The purpose of this article is to show how attention on ‘place’ can be productive in methodology concerning the bodily relations, movements and expressions of children up to three years of age who are enrolled in kindergarten. While research that has adopted a hermeneutic and phenomenological approach has contributed to important knowledge concerning young children, we propose re-thinking methodology that takes children’s bodily relations, movements and expressions into concern. Using ‘place’ as a lens, we show how power relations are interrupted and allow for alternative ways for the researcher to relate to data. Inspired by Somerville (2010), elements of place are situated at the centre of the research analysis. The three key elements of place that are put to work are as follows: our relationship to place is constituted in stories and other representations; place learning is local and embodied; and place is a contact zone for cultural contact. The paper is part of a research project which explores how place can be more explicit in educational practices to strengthen kindergarten as a learning arena. We seek to explore how place relations work and what they have the possibility of producing in the analyzing process.
Telling tales on either side of the teacher: methods of researching professional and biographical transformations in the context of Education
Authors: Hayler Mike , Edmond Nadia
Published: December 2014

This paper discusses the approaches and research methods used in two projects which examine professional transformations on ‘either side’ of the school teacher. The authors consider how the projects drew upon the different yet potentially complimentary methodological approaches of discourse analysis and autoethnography in the examination of professional identity. Following a description of the projects and the chosen methods, which includes discussion of the respective traditions from which they stem, the approaches are compared and contrasted through analysis of their application with a focus upon their various advantages and limitations within these particular contexts. The authors discuss these examples in terms of the wider discussion of quality and rigour in qualitative research and as a contribution to the debates on the complementarity of different qualitative approaches.
Overlapping fern and Bryophyte hotspots: Assessing ferns as a predictor of Bryophyte diversity
Authors: Nagalingum Nathalie S , Knerr Nunzio , Mishler Brent D , Cargill D Christine
Published: December 2014

Bryophytes are significant contributors to floristic diversity, but they are often neglected in field surveys and collections.

Thus, in order to obtain more accurate estimates of plant richness, there must be reliable estimates of bryophyte diversity. To address this, we examined whether another plant group, namely the ferns, could be used as a surrogate for bryophytes. We used datasets spanning the entire Australian continent for mosses, liverworts, liverworts+hornworts, ferns, and conifers (hornworts were aggregated into the group liverworts+hornworts). Two measures of richness were examined across the continent (as 50 km × 50 km grid cells): uncorrected richness and sample-standardised richness. We calculated the correlations among richness of all of the groups to test the hypothesis that fern diversity predicts bryophyte diversity

(because of shared ecological preferences) while conifer diversity does not. Conifers showed very little correlation to

either of the four plant groups, whereas ferns were highly correlated to mosses and to a lesser extent to liverworts and liverworts+hornworts. Liverworts, as well as liverworts+hornworts, and mosses were also strongly correlated. These results indicate that surrogates can assist in estimating the diversity and the conservation of other poorly collected plant groups.
Interpreting Mars ionospheric anomalies over crustal magnetic field regions using a 2‐D ionospheric model
Authors: Matta Majd , Mendillo Michael , Withers Paul , Morgan Dave
Published: December 2014

The spatially inhomogeneous, small‐scale crustal magnetic fields of Mars influence the escape of planetary atmospheric species and the interaction of the solar wind with the ionosphere. Understanding the plasma response to crustal magnetic field regions can therefore provide insight to ionospheric structure and dynamics. To date, several localized spatial structures in ionospheric properties that have been observed over regions of varying magnetic field at Mars have yet to be explained. In this study, a two‐dimensional ionospheric model is used to simulate the effects of field‐aligned plasma transport in regions of strong crustal magnetic fields. Resulting spatial and diurnal plasma distributions are analyzed and found to agree with observations from several spacecraft and offer compelling interpretations for many of the anomalous ionospheric behaviors observed at or near regions of strong crustal magnetic fields on Mars.
Gas and solute diffusion in partially saturated porous media: Percolation theory and Effective Medium Approximation compared with lattice Boltzmann simulations
Authors: Ghanbarian Behzad , Daigle Hugh , Hunt Allen G. , Ewing Robert P. , Sahimi Muhammad
Published: December 2014

Understanding and accurate prediction of gas or liquid phase (solute) diffusion are essential to accurate prediction of contaminant transport in partially saturated porous media. In this study, we propose analytical equations, using concepts from percolation theory and the Effective Medium Approximation (EMA) to model the saturation dependence of both gas and solute diffusion in porous media. The predictions of our theoretical approach agree well with the results of nine lattice Boltzmann simulations. We find that the universal quadratic scaling predicted by percolation theory, combined with the universal linear scaling predicted by the EMA, describes diffusion in porous media with both relatively broad and extremely narrow pore size distributions.
CCN closure study: Effects of aerosol chemical composition and mixing state
Authors: Bhattu Deepika , Tripathi S. N.
Published: December 2014

This study presents a detailed cloud condensation nuclei (CCN) closure study that investigates the effects of chemical composition (bulk and size resolved) and mixing state (internal and external) on CCN activity of aerosols. Measurements of the chemical composition, aerosol size distribution, total number concentration, and CCN concentration at supersaturation (SS = 0.2–1.0%) were performed during the winter season in Kanpur, India. Among the two cases considered here, better closure results are obtained for case 1 (low total aerosol loading, 49.54 ± 26.42 μg m−3, and high O:C ratio, 0.61 ±0.07) compared to case 2 (high total aerosol loading, 101.05 ± 18.73 μg m−3, and low O:C ratio, 0.42 ±0.06), with a maximum reduction of 3–81% in CCN overprediction for all depleted SS values (0.18–0.60%). Including the assumption that less volatile oxidized organic aerosols represent the soluble organic fraction reduced the overprediction to at most 40% and 129% in the internal and external mixing scenarios, respectively. At higher depleted SS values (0.34–0.60%), size‐resolved chemical composition with an internal mixing state performed well in CCN closure among all organic solubility scenarios. However, at a lower depleted SS value (0.18%), closure is found to be more sensitive to both the chemical composition and mixing state of aerosols. At higher SS values, information on the solubility of organics and size‐resolved chemical composition is required for accurate CCN predictions, whereas at lower SS values, information on the mixing state in addition to the solubility of organics and size‐resolved chemical composition is required. Overall, κtotal values are observed to be independent of the O:C ratio [κtotal= (0.36 ±0.01) × O:C − (0.03 ± 0.01)] in the range of 0.2<O:C<0.81, which indicates that the variation in the chemical composition of aerosols is not well represented by the changes in the O:C ratio alone.
Wind‐driven circulation in Titan's seas
Authors: Tokano Tetsuya , Lorenz Ralph D.
Published: December 2014

Circulation in Titan's seas forced by wind is simulated by an ocean circulation model using surface wind data predicted by a global circulation model. Wind‐driven circulation is insignificant throughout much of the annual cycle but becomes significant from late spring to late summer, when the wind stress becomes strong. The large‐scale circulation in summer is predominantly southward near the sea surface and northward near the sea bottom. The sea surface current can get as fast as 5 cms−1 in some areas. Titan's rotation affects the vertical structure of sea currents in the form of an Ekman spiral if the wind is strong. The maximum wind setup at the shores is of the same order of magnitude as the tidal range. Wind stirring may reduce thermal stratification in summer but may be unable to destroy stratification of methane‐rich liquids on top of ethane‐rich liquids that can result from imbalances between evaporation and precipitation.
Brain alterations within the first 100 days of HIV infection
Authors: Ragin Ann B. , Wu Ying , Gao Yi , Keating Sheila , Du Hongyan , Sammet Christina , Kettering Casey S. , Epstein Leon G.
Published: December 2014

Objective

Brain involvement is a serious complication of HIV infection. The earliest changes in the brain, which represents an anatomic site for viral persistence, are largely unknown.

Methods

This investigation used quantitative Magnetic Resonance methodologies, including high resolution and diffusion tensor (DTI) imaging, to evaluate the brain in 15 HIV and 20 seronegative subjects. All HIV subjects were antibody nonreactive with assay‐estimated infection duration of less than 100 days.

Results

Brain volumetric analysis revealed reduced parenchyma with enlargement of the third ventricle and brainstem. DTI quantified loss of white matter integrity in the corpus callosum and diffusion alterations in caudate. Cognitive differences were indicated in psychomotor speed and visual recall. There were no differences between antiretroviral‐initiated and naïve HIV subgroups.

Interpretation

These findings, quantified within 100 days of infection, shed light on the earliest brain changes in HIV infection. Onset of neural injury may date to initial viral invasion and the transient early period of unchecked viremia and marked immunosuppression of the seroconversion period.
Lead exposure and increased food allergic sensitization in U.S. children and adults
Authors: Mener David J. , Garcia‐Esquinas Esther , Navas‐Acien Ana , Dietert Rodney R. , Shargorodsky Josef , Lin Sandra Y.
Published: December 2014

Background

Whether blood lead levels are associated with sensitization to food allergens in adults and children is unclear. Prior studies have shown that exposure to lead is associated with atopic sensitization and modulation of several cytokines (eg, interleukin [IL]‐12, IL‐10, interferon [IFN]‐γ, and IL‐4 production) and with T‐cell dysregulation and bias toward T helper 2 (Th2) activity. The objective of this work was to assess whether exposure to lead is independently associated with allergic symptoms and sensitizations in a large nationally representative sample of children and adults.

Methods

We studied 2712 children and 4333 adults enrolled in the 2005‐2006 cycle of the National Health and Nutritional Examination Surveys (NHANES). Participants were tested for serum‐specific immunoglobulin E (IgE) levels to food allergens as well as blood lead levels. Food allergens tested included shrimp, egg, peanut, and milk. Logistic regression models adjusted for demographic factors, body mass index, history of asthma, smoking, housing characteristics, and current exposure to animals in the home, to assess the association of blood lead levels with sensitization to food allergens.

Results

Median (interquartile range [IQR]) for serum blood was 0.87 μg/L (0.61 to 1.31) in children and 1.48 μg/L (0.92 to 2.34) in adults. At baseline, 672 (24.7%) of children participants and 719 (16.6%) of adult participants tested positive for increased sensitization to food allergens. A 2‐fold increase in blood lead levels in adult participants was associated with increased sensitization to food allergens (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.02 to 1.22). Blood lead was not associated with sensitization to food allergens among pediatric participants (OR, 0.95; 95% CI, 0.82 to 1.10).

Conclusion

Exposure to lead was associated with increased odds of sensitization to food allergens in adult but not children participants.
Evaluation of transfer of wine aroma compounds through PET bottles
Authors: Dombre Clara , Chalier Pascale
Published: December 2014

Aroma compound could be lost during food storage in polymer packaging by transfers through material. The aim of this study was to develop a method that allows evaluating wine aroma compounds permeation through active PET bottles. A semiquantitative method has been adapted to the system. Results showed a regular permeation of all studied aroma compounds but a high variation between replicates. In active PET bottle containing 1% of oxygen scavenger, amount lost by permeation after 12 months storage at 20°C was about 6.13 ± 0.37 µgbottle−1. When 50% of recycled PET was added to active PET bottle, permeation rate was increased about 15%. The study of sorption of aroma compounds in both polymer matrices did not allow to explain this difference of permeation, but the structure of recycled PET seemed to induce modifications in aroma compound diffusion through active PET which could increase transfer. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41784.
Chemical polymerization of pyrrole in the presence of l‐serine or l‐glutamic acid: Electrically controlled amoxicillin release from composite hydrogel
Authors: Valencia Castro Leonardo Enrique , Pérez Martínez Cinthia Jhovanna , del Castillo Castro Teresa , Castillo Ortega María Mónica , Encinas José Carmelo
Published: December 2014

Polypyrrole (PPy) was chemically prepared from aqueous solutions individually containing l‐serine or l‐glutamic acid, with the addition of ammonium persulfate as the oxidant. The electrical, XPS and FTIR characterizations indicated that the amino acids co‐doped the PPy backbone. TEM revealed that PPy presented a quasi‐spherical morphology with diameters in nanometric scale. The nanostructures of PPy‐glutamic acid efficiently adsorbed therapeutic doses of amoxicillin. Composite hydrogels were obtained by the entrapment of amoxicillin‐loaded PPy in polyacrylamide network. The antibiotic molecules can be subsequently released (or sustained) from composite hydrogel in response to application (or removal) of electrical stimulation. This tuning release profile can lead to promising drug delivery applications such as implantable devices and iontophoretic systems. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41804.
Design, Synthesis, and Biological Evaluation of Novel 2H‐Pyran‐2‐one Derivatives as Potential HIV‐1 Reverse Transcriptase Inhibitors
Authors: Defant Andrea , Mancini Ines , Tomazzolli Rossella , Balzarini Jan
Published: December 2014

In search for more effective drugs against HIV infection acting as non‐nucleoside reverse transcriptase inhibitors (NNRTIs), a series of new molecules with hybrid structures based on the natural product (+)‐calanolide A and the synthetic molecule α‐APA, known as potent and selective inhibitors of this enzyme, were selected by docking calculations. A convergent synthetic strategy gave 21 compounds with a 2H‐pyran‐2‐one structural unit and bearing isosteric modifications, which were tested against HIV‐infected CEM cell cultures. Only compound 6 (4‐((2‐(1H‐indol‐3‐yl)ethyl)amino)‐6‐methyl‐2H‐pyran‐2‐one) displayed inhibitory activity (EC50: 25–50 µM). However, it was associated with a relatively high cytostatic effect on human T lymphocyte (CEM) cell cultures, not easily predictable, neither by the chemical structure nor by the computational approach. Although this drug design has failed in selecting a novel scaffold for NNRTIs, the results have driven the interest towards new potential antitumor molecules showing activity against L1210 murine leukemia and HeLa cervix carcinoma cells, among which compound 21 (6‐methyl‐4‐((2‐(naphthalen‐1‐yl)ethyl)sulfonyl)‐2H‐pyran‐2‐one) was the most effective (IC50: 0.95 and 2.9 µM, respectively).
Parallel construction of decision trees with consistently non‐increasing expected number of tests
Authors: Ben‐Gal Irad , Trister Chavazelet
Published: December 2014

In recent years, with the emergence of big data and online Internet applications, the ability to classify huge amounts of objects in a short time has become extremely important. Such a challenge can be achieved by constructing decision trees (DTs) with a low expected number of tests (ENT). We address this challenge by proposing the ‘save favorable general optimal testing algorithm’ (SF‐GOTA) that guarantees, unlike conventional look‐ahead DT algorithms, the construction of DTs with monotonic non‐increasing ENT. The proposed algorithm has a lower complexity in comparison to conventional look‐ahead algorithms. It can utilize parallel processing to reduce the execution time when needed. Several numerical studies exemplify how the proposed SF‐GOTA generates efficient DTs faster than standard look‐ahead algorithms, while converging to a DT with a minimum ENT.
Purification and characterization of an intracellular levansucrase derived from Bacillus methylotrophicus SK 21.002
Authors: Li Runjing , Zhang Tao , Jiang Bo , Mu Wanmeng , Miao Ming
Published: December 2014

An intracellular levansucrase from Bacillus methylotrophicus SK 21.002 was isolated, purified, and characterized. The final specific levansucrase activity was 135.40 U/mg protein with an 11.78‐fold enrichment and a 9.28% recovery rate. The molecular weight of the enzyme was approximately 60,000 Da as evaluated by gel filtration and SDS‐PAGE. Both the maximum transfructosylation and hydrolytic activities were observed at pH 6.5. The enzyme exhibited optimum transfructosylation activity at 40°C, whereas the optimum temperature of hydrolytic activity was 45°C. Cu2+, Fe2+, Zn2+, and Ni2+ inhibited both the transfructosylation and hydrolytic activities up to 100%, whereas Mn2+ inhibited only hydrolytic activity. Ca2+ and Mg2+ stimulated both transfructosylation and hydrolytic activities. The chemical modifiers (n‐bromosuccinimide and phenylmethanesulfonyl fluoride) strongly inhibited hydrolytic and transfructosylation activity of the levansucrase. The Km and Vmax values of the purified levansucrase were 117.2 mM and 33.23 μmol/mg·Min, respectively. When the fructose concentration was below 0.2 M, higher fructose concentrations promoted the transfructosylation and inhibited the hydrolytic activity.
Robust enzyme design: Bioinformatic tools for improved protein stability
Authors: Suplatov Dmitry , Voevodin Vladimir , Švedas Vytas
Published: December 2014

The ability of proteins and enzymes to maintain a functionally active conformation under adverse environmental conditions is an important feature of biocatalysts, vaccines, and biopharmaceutical proteins. From an evolutionary perspective, robust stability of proteins improves their biological fitness and allows for further optimization. Viewed from an industrial perspective, enzyme stability is crucial for the practical application of enzymes under the required reaction conditions. In this review, we analyze bioinformatic‐driven strategies that are used to predict structural changes that can be applied to wild type proteins in order to produce more stable variants. The most commonly employed techniques can be classified into stochastic approaches, empirical or systematic rational design strategies, and design of chimeric proteins. We conclude that bioinformatic analysis can be efficiently used to study large protein superfamilies systematically as well as to predict particular structural changes which increase enzyme stability. Evolution has created a diversity of protein properties that are encoded in genomic sequences and structural data. Bioinformatics has the power to uncover this evolutionary code and provide a reproducible selection of hotspots – key residues to be mutated in order to produce more stable and functionally diverse proteins and enzymes. Further development of systematic bioinformatic procedures is needed to organize and analyze sequences and structures of proteins within large superfamilies and to link them to function, as well as to provide knowledge‐based predictions for experimental evaluation.
Aminocatalytic Cross‐Coupling Approach via Iminium Ions to Different CC Bonds
Authors: Mupparapu Nagaraju , Battini Narsaiah , Battula Satyanarayana , Khan Shahnawaz , Vishwakarma Ram A. , Ahmed Qazi Naveed
Published: December 2014

Given the attractive ability of iminium ions to functionalize molecules directly at ostensibly unreactive positions, the reactivity of iminium ions, in which an α CH2 group is replaced by CO was explored. Background studies on the ability of such iminium cations to promote reactions via an iminium‐catalyzed or iminium‐equivalent pathway are apparently unavailable. Previously, tandem cross‐coupling reactions were reported, in which an iminium ion undergoes nucleophilic 1,2‐addition to give a putative three‐component intermediate that abstracts a proton in situ and undergoes self‐deamination followed by unprecedented DMSO/aerobic oxidation to generate α‐ketoamides. However, later it was observed that iminium ions can generate valuable α‐ketoamides through simple aerobic oxidation. In all reactions, iminium ions were generated in situ by reaction of 2‐oxoaldehydes with secondary amines.
What Controls the Magnetic Exchange Interaction in Mixed‐ and Homo‐Valent Mn7 Disc‐Like Clusters? A Theoretical Perspective
Authors: Vignesh Kuduva R. , Langley Stuart K. , Murray Keith S. , Rajaraman Gopalan
Published: December 2014

Density functional theory (DFT) studies have been undertaken to compute the magnetic exchange and to probe the origin of the magnetic interactions in two hetero‐ and two homo‐valent heptanuclear manganese disc‐like clusters, of formula [MnII4MnIV3(tea)(teaH2)3(peolH)4] (1), [MnII4MnIII3F3(tea)(teaH)(teaH2)2(piv)4(Hpiv)(chp)3] (2), [MnII7(pppd)6(tea)(OH)3] (3) and [MnII7 (paa)6(OMe)6] (4) (teaH3=triethanolamine, peolH4=pentaerythritol, Hpiv=pivalic acid, Hchp=6‐chloro‐2‐hydroxypyridine, pppd=1‐phenyl‐3‐(2‐pyridyl) propane‐1,3‐dione; paaH=N‐(2‐pyridinyl)acetoacetamide). DFT calculations yield J values, which reproduce the magnetic susceptibility data very well for all four complexes; these studies are also highlighting the likely ageing/stability problems in two of the complexes. It is found that the spin ground states, S, for complexes 1–4 are drastically different, varying from S=29/2 to S=1/2. These values are found to be controlled by the nature of the oxidation state of the metal ions and minor differences present in the structures. Extensive magneto–structural correlations are developed for the seven building unit dimers present in the complexes, with the correlations unlocking the reasons behind the differences in the magnetic properties observed. Independent of the oxidation state of the metal ions, the Mn‐O‐Mn/Mn‐F‐Mn angles are found to be the key parameters, which significantly influence the sign as well as the magnitude of the J values. The magneto–structural correlations developed here, have broad applicability and can be utilised to understand the magnetic properties of other Mn clusters.
Amphiphilic Polyoxometalates for the Controlled Synthesis of Hybrid Polystyrene Particles with Surface Reactivity
Authors: Lesage de La Haye Jennifer , Guigner Jean‐Michel , Marceau Eric , Ruhlmann Laurent , Hasenknopf Bernold , Lacôte Emmanuel , Rieger Jutta
Published: December 2014

Amphiphilic organo‐polyoxometalates (POMs) used in the radical emulsion polymerization of styrene allowed the preparation in aqueous medium of stable 50–100 nm polystyrene–POM composite latexes. Thanks to the presence of a trithiocarbonate group in the POM amphiphile, POMs could be covalently linked to the polymer particle surface. The chemical and catalytic integrity of the POMs was confirmed, and the POM‐mediated surface photoactivity of the latexes was demonstrated by the spatially controlled nucleation of silver nanoparticles at the periphery of the composites.
Peptoid‐Ligated Pentadecanuclear Yttrium and Dysprosium Hydroxy Clusters
Authors: Thielemann Dominique T. , Wagner Anna T. , Lan Yanhua , Oña‐Burgos Pascual , Fernández Ignacio , Rösch Esther S. , Kölmel Dominik K. , Powell Annie K. , Bräse Stefan , Roesky Peter W.
Published: December 2014

Invited for the cover of this issue are the groups of Yanhua Lan, Peter W. Roesky, and Stefan Bräse at the Karlsruhe Institute of Technology, and Ignacio Fernández at the University of Almería. The image depicts seals on a North Sea beach. Seals are known to be very skilled at balancing and other tricks, whereas our skills include crystallizing new compounds and further examining their properties. Read the full text of the article at 10.1002/chem.201405569.
Probing o‐Diphenylphosphanyl Benzoate (o‐DPPB)‐Directed CC Bond Formation: Total Synthesis of Dictyostatin
Authors: Wünsch Sebastian , Breit Bernhard
Published: December 2014

Herein, we report a robust total synthesis of dictyostatin. This polyketide natural product has attracted much attention because of its impressive antiproliferative activity against several human cancer‐cell lines. We accomplished its synthesis in a highly convergent manner from three fragments of equal complexity, which were prepared on multigram scale. The southern and northwestern subunits were constructed through application of our o‐DPPB‐directed hydroformylation and allylic substitution methodology, respectively. These methods generated the C6 and C14 stereocenters of dictyostatin with good diastereoselectivities and simultaneously allowed further elaboration of the fragments by Wittig olefination and Sharpless asymmetric epoxidation, respectively. The compelling performance of the hydroformylation and allylic substitution with regard to practicability, selectivity, and scale underline their value for the construction of propionate motifs.
Culture, leadership and motivation in two Commonwealth Caribbean countries: One look at the African Diaspora
Authors: Holder Khaleid , Knight Nicole , Punnett Betty Jane , Charles Reccia
Published: December 2014

Little is known of Caribbean people's views on their culture or of their beliefs regarding leadership and motivation. This study reports the results of a Delphi Technique with people in leadership positions and focus groups. Across groups, responses were relatively consistent: ethnicity and culture are described as influenced by religion, and Christianity in particular; African roots and country of origin are important; effective leaders are charismatic, visionary, results oriented, and they motivate others, lead by example, and develop vision and goals. Leaders believe motivation comes from making a difference for others. Nonleaders believe leaders are influenced by financial rewards and self‐fulfilment; nonleaders are motivated primarily by financial rewards. The results are generally similar to Western beliefs, but some interesting differences are identified. Copyright © 2014 ASAC. Published by John Wiley & Sons, Ltd.
Local adaptations in bryophytes revisited: the genetic structure of the calcium‐tolerant peatmoss Sphagnum warnstorfii along geographic and pH gradients
Authors: Mikulášková Eva , Hájek Michal , Veleba Adam , Johnson Matthew G. , Hájek Tomáš , Shaw Jonathan A.
Published: December 2014

Bryophytes dominate some ecosystems despite their extraordinary sensitivity to habitat quality. Nevertheless, some species behave differently across various regions. The existence of local adaptations is questioned by a high dispersal ability, which is thought to redistribute genetic variability among populations. Although Sphagnum warnstorfii is an important ecosystem engineer in fen peatlands, the causes of its rather wide niche along the pH/calcium gradient are poorly understood. Here, we studied the genetic variability of its global populations, with a detailed focus on the wide pH/calcium gradient in Central Europe. Principal coordinates analysis of 12 polymorphic microsatellite loci revealed a significant gradient coinciding with water pH, but independent of geography; even samples from the same fens were clearly separated along this gradient. However, most of the genetic variations remained unexplained, possibly because of the introgression from phylogenetically allied species. This explanation is supported by the small heterogeneous cluster of samples that appeared when populations morphologically transitional to S. subnites, S. rubellum, or S. russowii were included into the analysis. Alternatively, this unexplained variation might be attributed to a legacy of glacial refugia with recently dissolved ecological and biogeographic consequences. Isolation by distance appeared at the smallest scale only (up to 43 km). Negative spatial correlations occurred more frequently, mainly at long distances (up to 950 km), implying a genetic similarity among samples which are very distant geographically. Our results confirm the high dispersal ability of peatmosses, but simultaneously suggested that their ability to cope with a high pH/calcium level is at least partially determined genetically, perhaps via specific physiological mechanisms or a hummock‐forming ability.
Inhibition of Alkali–Silica Reaction in Hollow Porcelain Insulator
Authors: Shinka Hiroyuki , Yamamoto Takeshi , Komatsu Hiroaki , Hongakiuchi Takeshi
Published: December 2014

Hollow porcelain insulators are widely used in gas‐insulated power apparatus and oil‐filled power apparatus. Previously, it was thought that hollow porcelain insulators are not subject to aging deterioration. However, gas and oil leaks caused by the alkali–silica reaction in the porcelain where it is in contact with cementing parts have been reported in recent years. We experimentally verified the generation process of the alkali–silica reaction by using a hollow porcelain insulator removed from the substation, and examined an inhibition method of alkali–silica reaction based on the use of lithium nitrite. It was found that the alkali–silica reaction occurs in the hollow porcelain insulator and that lithium nitrite is effective for inhibition of the alkali–silica reaction.
Structural Variation in [PdX2{RE(CH2)nNMe2}] (E = Se, Te; X = Cl, OAc) Complexes: Experimental Results, Computational Analysis, and Catalytic Activity in Suzuki Coupling Reactions
Authors: Paluru Dilip K. , Dey Sandip , Wadawale Amey , Maity Dilip K. , Bhuvanesh Nattamai , Jain Vimal K.
Published: December 2014

A series of chalcogenoether ligands RE(CH2)nNMe2 (1) [E = Se or Te; R = Ph, o‐tol (o‐tol = ortho‐tolyl), Mes (Mes = 2,4,6‐trimethylphenyl); n = 2 or 3] and their palladium complexes [PdX2{RE(CH2)nNMe2}]m [X = Cl (2) or OAc (3); m = 1, 2] were synthesized. Complexes [PdCl2(RECH2CH2NMe2)] [R/E = Ph/Se (2a), Mes/Se (2b), Mes/Te (2c)] were isolated as monomers. Complexes [PdCl2(RECH2CH2CH2NMe2)]m [R/E = Ph/Se (2d), Ph/Te (2e), o‐tol/Te (2f)] exist in one monomeric and two dimeric forms in solution; their ratio depends on E and R as revealed by NMR spectroscopic data. Crystal structures of monomeric 2a, 2b, 3b, 2d, 2f, and dimeric 2e were established. Compounds 2a, 2d, 2e, and 2f were also investigated by means of density functional theory (DFT)‐based quantum chemical calculations to understand structural variation. The complexes that contained acetate or chalcogenoether ligands with n = 3 showed higher catalytic activity than other derivatives in Suzuki C–C cross‐coupling reactions.
Oleaginous yeast Cryptococcus curvatus exhibits interplay between biosynthesis of intracellular sugars and lipids
Authors: Tchakouteu Sidoine Sadjeu , Chatzifragkou Afroditi , Kalantzi Ourania , Koutinas Apostolis A. , Aggelis George , Papanikolaou Seraphim
Published: December 2014

Patterns of the biosynthesis of major metabolites of the oleaginous yeast Cryptococcus curvatus NRRL Y‐1511 were investigated during cultivation on sugar‐based media. When lactose or sucrose was employed as substrate under nitrogen‐limited conditions, the yeast strain accumulated high quantities of intra‐cellular total sugars (ITS) at the beginning of fermentation (up to 68% w/w), with ITS values progressively decreasing to 20%, w/w, at the end of the fermentation. Decrease in ITS content and consumption of extra‐cellular lactose led to a subsequent rise in lipid accumulation, reaching 29.8% in dry cell weight at 80 g/L of initial lactose concentration. Lactose was a more favorable substrate for lipid production than sucrose. In nitrogen‐excess conditions, ITS were produced in significant quantities despite the continuous presence of nitrogen in the medium. Growth on lactose was not followed by secretion of extra‐cellular β‐galactosidase. High quantities of extra‐cellular invertase were observed during growth on sucrose. The composition of ITS was highly influenced by the sugar used as substrate. Cellular lipids contained mainly palmitic and to lesser extent linoleic and stearic acids. This is the first report in the literature that demonstrates the interplay between the biosynthesis of intra‐cellular total sugars and lipid synthesis for oleaginous yeast strains.

Practical applications: Cryptococcus curvatus represents a promising candidate for the successful production of microbial lipids and polysaccharides during growth on several types of low‐cost sugars utilized as substrates. Thus, C. curvatus could be used to produce a variety of metabolites useful for industrial biotechnology.

Interplay between the biosynthesis of intra‐cellular total sugars produced per unit of dry weight (YITS/X %, w/w) and intra‐cellular lipids produced per unit of dry weight (YL/X %, w/w) of Cryptococcus curvatus, during growth on lactose, under nitrogen‐limited conditions.
Copper(II)‐Promoted C–C Bond Formation by Oxidative Coupling of Two C(sp3)–H Bonds Adjacent to Carbonyl Group to Construct 1,4‐Diketones and Tetrasubstituted Furans
Authors: Mao Shuai , Gao Ya‐Ru , Zhang Shao‐Liang , Guo Dong‐Dong , Wang Yong‐Qiang
Published: December 2014

The copper(II)‐promoted C–C bond formation from the coupling of two C(sp3)–H bonds that are adjacent to a carbonyl group was achieved. This protocol offers a simple and efficient approach to 2,3‐disubstituted 1,4‐diketones and tetrasubstituted furans. This method features a wide substrate scope and high functional group tolerance.
Fluidic dielectrophoresis: The polarization and displacement of electrical liquid interfaces
Authors: Mavrogiannis Nicholas , Desmond Mitchell , Gagnon Zachary R.
Published: December 2014

Traditional particle‐based dielectrophoresis has been exploited to manipulate bubbles, particles, biomolecules, and cells. In this work, we investigate analytically and experimentally how to utilize Maxwell–Wagner polarization to initiate fluidic dielectrophoresis (fDEP) at electrically polarizable aqueous liquid–liquid interfaces. In fDEP, an AC electric field is applied across a liquid electrical interface created between two coflowing fluid streams with different electrical properties. When potentials as low as 2 volts are applied, we observe a frequency‐dependent interfacial displacement that is dependent on the relative differences in the electrical conductivity ( and dielectric constant ( between the two liquids. At low frequency this deflection is independent of dielectric constant, while at high frequency it is independent of electrical conductivity. At intermediate frequencies, we observe an fDEP cross‐over frequency that is independent of applied voltage, sensitive to both fluid electrical properties, and where no displacement is observed. An analytical fDEP polarization model is presented that accurately predicts the liquid interfacial cross‐over frequency, the dependence of interfacial displacement on liquid electrical conductivity and dielectric constant, and accurately scales the measured fDEP displacement data. The results show that miscible aqueous liquid interfaces are capable of polarizing under AC electric fields, and being precisely deflected in a direction and magnitude that is dependent on the applied electric field frequency.
Statistical modeling of the hormetic dose zone and the toxic potency completes the quantitative description of hormetic dose responses
Authors: Belz Regina G. , Piepho Hans-Peter
Published: December 2014

Quantifying the characteristics of hormesis provides valuable insights into this low-dose phenomenon and helps to display and capture its variability. A prerequisite to do so is a statistical procedure allowing quantification of general hormetic features, namely the maximum stimulatory response, the dose range of hormesis, and the distance from the maximum stimulation to the dose where hormesis disappears. Applying extensions of a hormetic dose-response model that is well-established in plant biology provides a direct estimation of several quantities, except the hormetic dose range. Another dose range that is difficult to model directly is the distance between the dose where hormesis disappears and the dose giving 50% inhibition, known as toxic potency. The present study presents 2 further model extensions allowing for a direct quantification of the hormetic dose range and the toxic potency. Based on this, a 4-step mathematical modeling approach is demonstrated to quantify various dose-response quantities, to compare these quantities among treatments, and to interrelate hormesis features. Practical challenges are exemplified, and possible remedies are identified. The software code to perform the analysis is provided as Supplemental Data to simplify adoption of the modeling procedure. Because numerous patterns of hormesis are observed in various sciences, it is clear that the proposed approach cannot cope with all patterns; however, it should be possible to analyze a great range of hormesis patterns. Environ Toxicol Chem 2015;34:1169–1177. © 2014 SETAC
Solid inclusion complex of terpinen‐4‐ol/β‐cyclodextrin: kinetic release, mechanism and its antibacterial activity
Authors: Yang Zujin , Xiao Zuobing , Ji Hongbing
Published: December 2014

Terpinen‐4‐ol has several biological properties, but its low stability and water‐solubility limit its use. This study reports the formation of a solid terpinen‐4‐ol/β‐cyclodextrin (β‐CD) inclusion complex via lyophilization. Release experiments were performed at various temperatures (40, 60, 80, and 100°C) with humidity of 70%. The release of terpinen‐4‐ol was significantly increased with rising temperature. Avrami's equation was used to analyse release kinetics and a good fit was observed for terpinen‐4‐ol release. In addition, the complex enhanced antibacterial activity against Staphylococcus aurueus, Pseudomonas aeruginosa and Escherichia coli, with concentration ranging from 1.25 mg/ml to 5 mg/ml. To explain the experimental data, physico‐chemical techniques have been utilized to investigate the inclusion complex of terpinen‐4‐ol with β‐CD. Finally, the possible structure of the complex was proposed by quantum chemical calculations. The results indicated that enhanced thermal stability and antibacterial activity of terpinen‐4‐ol could be attributed to the weak interactions of hydrogen bonds between terpinen‐4‐ol and β‐CD. Copyright © 2014 John Wiley & Sons, Ltd.
Incidence and long‐term survival of patients with de novo head and neck carcinoma after liver transplantation
Authors: Coordes Annekatrin , Albers Andreas E. , Lenarz Minoo , Seehofer Daniel , Puhl Gero , Pascher Andreas , Neuhaus Ruth , Neuhaus Peter , Pratschke Johann , Andreou Andreas
Published: December 2014

Background

Liver transplant recipients have an increased risk of developing de novo malignancies.

Methods

We conducted a prospective evaluation of clinicopathological data and predictors for overall survival (OS) in patients with head and neck squamous cell carcinoma (HNSCC) after liver transplantation (1988 to 2010).

Results

Thirty‐three of 2040 patients who underwent liver transplantation (1.6%) developed de novo HNSCC. The incidence of HNSCC in liver transplant recipients with end‐stage alcoholic liver disease (26) was 5%. After a median follow‐up of 9 years, 1‐year, 3‐year, and 5‐year OS rates were 74%, 47%, and 34%, respectively. Tumor size, cervical lymph node metastases, tumor site, and therapy (surgery only vs surgery and adjuvant radiotherapy [RT]/chemoradiotherapy [CRT] vs RT/CRT only; p < .0001) were significantly associated with OS in univariate analysis. However, surgery only predicted OS independently in multivariate analysis.

Conclusion

Early diagnosis and surgical treatment of de novo HNSCC are crucial to the outcome. HNSCC risk should be taken into close consideration during posttransplantation follow‐up examinations, especially among patients with a positive history of smoking and alcohol consumption. © 2015 Wiley Periodicals, Inc. Head Neck 38: 707–714, 2016
Tobacco use and surgical outcomes in patients with head and neck cancer
Authors: Hatcher Jeanne L. , Sterba Katherine R. , Tooze Janet A. , Day Terry A. , Carpenter Matthew J. , Alberg Anthony J. , Sullivan Christopher A. , Fitzgerald Nora C. , Weaver Kathryn E.
Published: December 2014

Background

Tobacco use is a risk factor for head and neck cancer, but effects on postoperative outcomes are unclear.

Methods

Patients with head and neck cancer (n = 89) were recruited before surgery. We assessed self‐reported tobacco use status (never, former, or current) at study entry and recent tobacco exposure via urinary cotinine on surgery day. Outcomes included hospital length of stay (LOS) and complications.

Results

Most participants reported current (32.6%) or former (52.8%) tobacco use; 43.2% were cotinine‐positive on surgery day. Complications occurred in 41.6% and mean LOS was 4.0 and 8.8 days in patients who received low and high acuity procedures, respectively. Current and former smokers were over 6 times more likely to have complications than never smokers (p = .03). For high acuity procedures, LOS was increased in current (by 4.4 days) and former smokers (by 2.3 days; p = .02).

Conclusion

Tobacco use status is associated with postoperative complications and may distinguish at‐risk patients. © 2015 Wiley Periodicals, Inc. Head Neck 38: 700–706, 2016
Analysis of sentinel node biopsy combined with other diagnostic tools in staging cN0 head and neck cancer: A diagnostic meta‐analysis
Authors: Liao Li‐Jen , Hsu Wan‐Lun , Wang Chi‐Te , Lo Wu‐Chia , Lai Mei‐Shu
Published: December 2014

Background

The purpose of this was to find a staging strategy sensitive enough to reduce the risk of occult metastases in cN0 head and neck cancer to below 15% to 20%.

Methods

A total of 73 articles were selected for analysis of the diagnostic performance in staging cN0 head and neck cancer. Hypothetical estimation of negative predictive value (NPV) was calculated based on the Bayesian theory.

Results

The pooled estimates for sensitivity were 56.4% and 84.9% for ultrasound‐guided fine‐needle aspiration (FNA) and sentinel node biopsy (SNB). The pooled estimates for sensitivity were 47.0%, 56.6%, 48.3%, and 63.3% for CT, MRI, positron emission tomography (PET), and ultrasound, respectively. The pooled estimates for specificity were 88.9%, 82.5%, 86.2%, and 79.1% for CT, MRI, PET, and ultrasound. In estimation, the CT or MRI with SNB strategies had NPV higher than 85% even when the pretest metastatic rate was 60%.

Conclusion

The SNB procedure has the best performance. A combination of CT/MRI and SNB for cN0 head and neck cancer is preferred. © 2015 Wiley Periodicals, Inc. Head Neck 38: 628–634, 2016
Thyroid thyrothymic extension: An anatomic study in a surgical series
Authors: Sheahan Patrick , O'Duffy Fergal
Published: December 2014

Background

The thyrothymic extension (TTE) is a variable projection from the inferior thyroid pole along the course of the thyrothymic ligament. Awareness of the TTE is critical to ensure complete total thyroidectomy. However, there is little mention of the TTE in the literature. The purpose of the present study was to investigate the frequency of the TTE in our surgical series.

Methods

We conducted a prospective cohort study of 284 thyroid and parathyroid surgeries performed by a single surgeon.

Results

A TTE was present in 138 of 414 evaluable thyroid lobes (33.3%), with no predilection for left or right. The TTE was bilateral in 57% of cases. In 5 cases, there was significant nodular enlargement of the TTE. The inferior parathyroid gland was closely associated with 8% of TTEs.

Conclusion

The TTE is a commonly encountered projection from the inferior thyroid pole. Awareness of the TTE is important to ensure complete total thyroidectomy. © 2015 Wiley Periodicals, Inc. Head Neck 38: 732–735, 2016
Interpretation of the Swedish Self Evaluation of Communication Experiences after Laryngeal cancer: Cutoff levels and minimum clinically important differences
Authors: Tuomi Lisa , Johansson Mia , Andréll Paulin , Finizia Caterina
Published: December 2014

Background

The purpose of this study was to establish minimum clinically important difference (MCID) scores for the Swedish Self‐Evaluation of Communication Experiences after Laryngeal Cancer (S‐SECEL) in order to facilitate clinical interpretation and identify cutoff values for voice rehabilitation.

Method

One hundred nineteen patients with laryngeal cancer completed the S‐SECEL instrument and an anchor question regarding acceptability of speech in a social context pretreatment and 12‐month postoncologic treatment. Receiver operating characteristic (ROC) curves analysis was used for calculation of cutoff values.

Results

Voice rehabilitation cutoff values were identified for all domains (Total = 20; General = 4; Environmental = 16, and Attitudinal = 5), presenting acceptable sensitivity and specificity. Initial MCID estimates were obtained for all domains; improvement of −13 points (p < .0001) or a deterioration of +8 points (p = .035) for the Total domain.

Conclusion

MCID and cutoff scores for the S‐SECEL have been identified and may be used in clinical practice to help identify patients with laryngeal cancer in need of voice rehabilitation. © 2015 Wiley Periodicals, Inc. Head Neck 38: 689–695, 2016