bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating the capabilities and uncertainties of droplet measurements for the fog droplet spectrometer (FM-100)
Authors: Spiegel J. K. , Zieger P. , Bukowiecki N. , Hammer E. , Weingartner E. , Eugster W.
Published: September 2012

Abstract. Droplet size spectra measurements are crucial to obtain a quantitative microphysical description of clouds and fog. However, cloud droplet size measurements are subject to various uncertainties. This work focuses on the error analysis of two key measurement uncertainties arising during cloud droplet size measurements with a conventional droplet size spectrometer (FM-100): first, we addressed the precision with which droplets can be sized with the FM-100 on the basis of the Mie theory. We deduced error assumptions and proposed a new method on how to correct measured size distributions for these errors by redistributing the measured droplet size distribution using a stochastic approach. Second, based on a literature study, we summarized corrections for particle losses during sampling with the FM-100. We applied both corrections to cloud droplet size spectra measured at the high alpine site Jungfraujoch for a temperature range from 0 °C to 11 °C. We showed that Mie scattering led to spikes in the droplet size distributions using the default sizing procedure, while the new stochastic approach reproduced the ambient size distribution adequately. A detailed analysis of the FM-100 sampling efficiency revealed that particle losses were typically below 10% for droplet diameters up to 10 μm. For larger droplets, particle losses can increase up to 90% for the largest droplets of 50 μm at ambient wind speeds below 4.4 m s−1 and even to >90% for larger angles between the instrument orientation and the wind vector (sampling angle) at higher wind speeds. Comparisons of the FM-100 to other reference instruments revealed that the total liquid water content (LWC) measured by the FM-100 was more sensitive to particle losses than to re-sizing based on Mie scattering, while the total number concentration was only marginally influenced by particle losses. Consequently, for further LWC measurements with the FM-100 we strongly recommend to consider (1) the error arising due to Mie scattering, and (2) the particle losses, especially for larger droplets depending on the set-up and wind conditions.
High tolerance of protozooplankton to ocean acidification in an Arctic coastal plankton community
Authors: Aberle N. , Schulz K. G. , Stuhr A. , Ludwig A. , Riebesell U.
Published: September 2012

Abstract. Impacts of ocean acidification (OA) on marine biota have been observed in a wide range of marine systems. We used a mesocosm approach to study the response of a high Arctic coastal protozooplankton (PZP in the following) community during the post-bloom period in the Kongsfjorden (Svalbard) to direct and indirect effects of high pCO2/low pH. We found almost no direct effects of OA on PZP composition and diversity. Both, the relative shares of ciliates and heterotrophic dinoflagellates as well as the taxonomic composition of protozoans remained unaffected by changes in pCO2/pH. The different pCO2 treatments did not have any effect on food availability and phytoplankton composition and thus no indirect effects e.g. on the total carrying capacity and phenology of PZP could be observed. Our data points at a high tolerance of this Arctic PZP community to changes in pCO2/pH. Future studies on the impact of OA on plankton communities should include PZP in order to test whether the observed low sensitivity of protozoans to OA is typical for coastal communities where changes in seawater pH occur frequently.
Critical review of SWAT applications in the upper Nile basin countries
Authors: van Griensven A. , Ndomba P. , Yalew S. , Kilonzo F.
Published: September 2012

Abstract. The Soil and Water Assessment Tool (SWAT) is an integrated river basin model that is widely applied within the Nile basin. Up to date, more than 20 peer-reviewed papers describe the use of SWAT for a variety of problems in the upper Nile basin countries, such as erosion modelling, land use and climate change impact modelling and water resources management. The majority of the studies are focused on locations in the tropical highlands in Ethiopia and around Lake Victoria. The popularity of SWAT is attributed to the fact that the tool is freely available and that it is readily applicable through the development of geographic information system (GIS) based interfaces and its easy linkage to sensitivity, calibration and uncertainty analysis tools. The online and free availability of basic GIS data that are required for SWAT made its applicability more straightforward even in data-scarce areas. However, the easy use of SWAT may not always lead to appropriate models which is also a consequence of the quality of the available free databases in these regions. In this paper, we aim at critically reviewing the use of SWAT in the context of the modelling purpose and problem descriptions in the tropical highlands of the Nile basin countries. To evaluate the models that are described in journal papers, a number of criteria are used to evaluate the model set-up, model performances, physical representation of the model parameters, and the correctness of the hydrological model balance. On the basis of performance indicators, the majority of the SWAT models were classified as giving satisfactory to very good results. Nevertheless, the hydrological mass balances as reported in several papers contained losses that might not be justified. Several papers also reported the use of unrealistic parameter values. More worrying is that many papers lack this information. For this reason, most of the reported SWAT models have to be evaluated critically. An important gap is the lack of attention that is given to the vegetation and crop processes. None of the papers reported any adaptation to the crop parameters, or any crop-related output such as leaf area index, biomass or crop yields. A proper simulation of the land cover is important for obtaining correct runoff generation, evapotranspiration and erosion computations. It is also found that a comparison of SWAT applications on the same or similar case study but by different research teams and/or model versions resulted in very different results. It is therefore recommended to find better methods to evaluate the representativeness of the distributed processes and parameters (especially when land use studies are envisaged) or predictions of the future through environmental changes. The main recommendation is that more details on the model set-up, the parameters and outputs should be provided in the journal papers or supplementary materials in order to allow for a more stringent evaluation of these models.
Comparing historical and modern methods of Sea Surface Temperature measurement – Part 1: Review of methods, field comparisons and dataset adjustments
Authors: Matthews J. B. R.
Published: September 2012

Abstract. Sea Surface Temperature (SST) measurements have been obtained from a variety of different platforms, instruments and depths over the post-industrial period. Today most measurements come from ships, moored and drifting buoys and satellites. Shipboard methods include temperature measurement of seawater sampled by bucket and in engine cooling water intakes. Engine intake temperatures are generally thought to average a few tenths of a °C warmer than simultaneous bucket temperatures. Here I review SST measurement methods, studies comparing shipboard methods by field experiment and adjustments applied to SST datasets to account for variable methods. In opposition to contemporary thinking, I find average bucket-intake temperature differences reported from field studies inconclusive. Non-zero average differences often have associated standard deviations that are several times larger than the averages themselves. Further, average differences have been found to vary widely between ships and between cruises on the same ship. The cause of non-zero average differences is typically unclear given the general absence of additional temperature observations to those from buckets and engine intakes. Shipboard measurements appear of variable quality, highly dependent upon the accuracy and precision of the thermometer used and the care of the observer where manually read. Methods are generally poorly documented, with written instructions not necessarily reflecting actual practices of merchant mariners. Measurements cannot be expected to be of high quality where obtained by untrained sailors using thermometers of low accuracy and precision.
Comparing historical and modern methods of Sea Surface Temperature measurement – Part 2: Field comparison in the Central Tropical Pacific
Authors: Matthews J. B. R. , Matthews J. B.
Published: September 2012

Abstract. Discrepancies between historical Sea Surface Temperature (SST) datasets have been partly ascribed to use of different adjustments for variable measurement methods. Until recently adjustments had only been applied to bucket temperatures from the late 19th and early 20th century, with the aim of correcting their supposed coolness relative to engine cooling water intake temperatures (EIT). In the UK Met Office Hadley Centre SST 3 dataset (HadSST3) adjustments are applied to observations over its full duration, including those obtained by other methods. Here we evaluate such adjustments by direct field comparison of historical and modern methods of SST measurement. We compare wood, canvas and rubber bucket temperatures to 3 m seawater intake temperature along a Central Tropical Pacific transect conducted in May and June 2008. In contrast to the prevailing view we find no average differences between bucket temperatures obtained with different bucket types. Moreover, we observe strong near-surface temperature gradients day and night, indicating intake and bucket temperatures cannot be considered equivalent in this region. We suggest engine intake temperatures are unreliable as a source of SST given that they are often obtained by untrained non-scientist observers with low precision, inaccurate instruments at unknown intake depth. Using a physical model we demonstrate that warming of intake seawater by engine room air is unlikely a cause of negative average bucket-intake temperature differences, as sometimes suggested. We propose removal of intake temperatures and bucket adjustments from historical SST records and posit this will lead to their better capture of real long-term trends.
Attitudes and Opinions of Teachers towards Corporal Punishment
Authors: Fatima Dr. Nuzhat , Janjua Dr. Shafqat Ali , Nafees Dr. Muhammad , Masood Kamran
Published: September 2012

Corporal Punishment yields negative impact on the behaviors of students and thus their learning achievements remain lower. Sometime, in a particular situation, students’ exhibit relatively better results but they actually get fed up with the learning enrolment and intrinsically intend to go away from teaching learning process. This study was under taken to get the opinion of primary school teachers and their practical behaviors towards corporal punishment at primary level in the Govt. Schools of Rawalpindi and Islamabad. In order to collect data, a questionnaire containing 35 questions was developed in Urdu for seeking opinion of primary school teachers. The questionnaire had two parts; the first part pertained to information about different aspects related to the classroom situation while the second part contained an open-ended question asking for suggestions.  Stratified random sample technique was used but only those school were selected which were willing to respond and easy to approach.  Data collected through questionnaire were tabulated and analyzed.  Although difference of opinion was found among the teachers on all issues yet an overall majority opined that corporal punishment must not be there as it was the greatest negative variable for creating a conducive environment for teaching learning process. Key words:  Punishment, Learning Achievements, Learning Environment, Motivation, Satisfaction.
Pseudo Almost Automorphic Solutions for Differential Equations Involving Reflection of the Argument
Authors: Ait Dads Elhadi , Fatajou Samir , Khachimi Lahcen
Published: September 2012

By means of the fixed point methods and the properties of the pseudo almost automorphic functions, the existence and uniqueness of pseudo almost automorphic solutions are obtained for differential equations involving reflection of the argument. For the nonscalar, case we use the exponential dichotomy properties.
Indigenous Knowledge of Climatic Conditions for Sustainable Crop Production under Resource-Poor Farming Conditions Using Participatory Techniques
Authors: Nethononda L. O. , Odhiambo J.J. O , Paterson D G
Published: September 2012

Rambuda irrigation scheme is situated in Vhembe District of Limpopo Province in South Africa. It was established in 1952 and farmers do not have access to recorded climatic information. Farmers are growing crops on a trial and error basis, hence low yields and crop loses. The objective of the study was to investigate indigenous knowledge of climatic conditions relevant for crop production using participatory techniques. Situation analysis was conducted to gain information on factors influencing crop choice. Participatory exercise was conducted with 33 of 104 of plot-holders. Farmers could identify climatic factors important for crop production and those limiting to crop performance. Hot, dry conditions during August to October and January months were limiting to crops, particularly sweet potato production. The results showed that indigenous knowledge of climate needs to be considered during agricultural development planning and scientists need to investigate linkages between modern agro-meteorology and indigenous knowledge.
 
Morphological Study and Determination of M/E Ratio in the Bone Marrow of the Male Adult Ostriches (Struthio camelus)
Authors: Saeed Nazifi  , Mina Tadjalli  , Behrokh Marzban  , Banafsheh Majidi
Published: September 2012

Normal haematopoiesis, cellular components and M/E ratio in the bone marrow of the male adult ostriches (Struthio camelus)were studied. Bone marrow samples were collected from the proximal tibiotarsus bone of 10 healthy adult ostriches. The bone marrow smears were stained using the Giemsa stain. The results indicated that the development and formation of blood cells in the bone marrow of partridge were similar to other birds. The morphology of the cells was similar to chickens, ducks, quail, and black-head gull. The mean myeloid/erythroid (M/E) ratio was 1.02, the mean erythroid percentage was 47.38%, the mean myeloid percentage was 48.15%, the mean thrombocytic percentage was 3.52% and the mean percentage of all other cells percentage was 0.99%
Une analyse des facteurs de risque dans l’apprentissage de la lecture chez l’enfant
Authors: Desrochers Alain , Carson Robyn , Daigle Daniel
Published: September 2012

Le but de cet article est de discuter des facteurs de risque associés aux difficultés que les enfants d’âge scolaire peuvent éprouver dans l’apprentissage de la lecture. D’entrée de jeu, nous posons que l’instruction publique obligatoire expose les enseignants à toute la diversité des aptitudes à cet apprentissage. On estime que l’enseignement universel, en classe ordinaire, répond aux besoins d’environ 75% des apprentis lecteurs. Mais qu’en est-il des autres? Quels sont les facteurs qui, chez eux, peuvent nuire à l’apprentissage de la lecture? Pour tenter une réponse à cette question, nous faisons d’abord le portrait des principales habiletés qui président au développement des normo-lecteurs. Puis, nous distinguons deux classes de facteurs de risque : les risques individuels et les risques environnementaux. Les risques connus et centrés sur les caractéristiques de l’individu sont associés à l’hérédité, aux déficits sensoriels, aux capacités cognitives générales et aux faiblesses dans le traitement de la langue orale ou écrite. Les facteurs connus et centrés sur le milieu d’apprentissage renvoient principalement aux activités d’enrichissement ou de formation dans le foyer familial ou à l’école. Nous discutons de leur nature et de leur impact sur l’apprentissage de la lecture.
Caractéristiques familiales associées aux trois profils du trouble déficitaire de l’attention/hyperactivité chez les enfants âgés de 6 à 9 ans
Authors: Richer Marie-Claude , Letarte Marie-Josée , Normandeau Sylvie
Published: September 2012

Selon l’American Psychiatric Association (APA, 1994), le trouble déficitaire de l’attention/hyperactivité (TDA/H) se divise en trois profils : inattention prédominante (TDA/H-I), hyperactivité-impulsivité prédominante (TDA/H-H) et mixte (TDA/H-M). L’objectif de cette étude est d’identifier les caractéristiques familiales associées aux trois profils du TDA/H en exerçant un contrôle statistique sur les variables de sexe et d’âge des enfants, ainsi que sur la prise de médication et la co-occurrence de troubles extériorisés et intériorisés. Les participants sont 110 familles d’enfants d’âge primaire présentant un TDA/H (TDA/H-I : n = 31, TDA/H-H : n = 11, TDA/H-M : n = 68) et prenant tous une médication appropriée. Les résultats d’une analyse de covariance multiple démontrent que les familles des trois profils se différencient uniquement au niveau du stress parental : les parents d’enfants ayant un TDA/H-I ressentent moins de stress que les parents d’enfants ayant un TDA/H-H ou un TDA/H-M. Par ailleurs, les résultats suggèrent qu’il est important de considérer la présence du trouble oppositionnel et la prise de médication dans l’étude des profils diagnostiques du TDA/H.
Compact Saloplastic Poly(Acrylic Acid)/Poly(Allylamine) Complexes: Kinetic Control Over Composition, Microstructure, and Mechanical Properties
Authors: Reisch Andreas , Tirado Patricia , Roger Emilie , Boulmedais Fouzia , Collin Dominique , Voegel Jean‐Claude , Frisch Benoît , Schaaf Pierre , Schlenoff Joseph B.
Published: September 2012

Durable compact polyelectrolyte complexes (CoPECs) with controlled porosity and mechanical properties are prepared by ultracentrifugation. Because the starting materials, poly(allylamine hydrochloride) (PAH) and poly(acrylic acid sodium salt) (PAA), are weak acids/bases, both composition and morphology are controlled by solution pH. In addition, the nonequilibrium nature of polyelectrolyte complexation can be exploited to provide a range of compositions and porosities under the influence of polyelectrolyte addition order and speed, and concentration. Confocal microscopy shows these “saloplastic” materials to be highly porous, where pore formation is attributed to a combination of deswelling of the polyelectrolyte matrix and expansion of small inhomogenities by osmotic pressure. The porosity (15–70%) and the pore size (<5 μm to >70 μm) of these materials can be tuned by adjusting the PAA to PAH ratio, the salt concentration, and the pH. The modulus of these CoPECs depends on the ratio of the two polyelectrolytes, with stoichiometric complexes being the stiffest due to optimized charge pairing, which correlates with maximized crosslinking density. Mechanical properties, pore sizes, and pore density of these materials make them well suited to three dimensional supports for tissue engineering applications.
Synthesis of polypyrrole‐modified TiO2 composite adsorbent and its adsorption performance on acid Red G
Authors: Li Jingjing , Feng Jiangtao , Yan Wei
Published: September 2012

The adsorption–desorption characteristics of Acid Red G (ARG) on the polypyrrole‐modified TiO2 (PPy/TiO2) composite as a novel adsorbent was investigated. PPy/TiO2 was synthesized via the in‐situ polymerization of pyrrole monomer in the prepared TiO2 sol solution. Results from X‐ray diffraction and Fourier transform infrared spectra indicated the formation of the PPy/TiO2 composite. The adsorption experiments showed that the modification of PPy substantially improved the adsorption and regeneration abilities of PPy/TiO2. The adsorption equilibrium was achieved in a short time of 20 min, and the adsorption kinetics followed the pseudo‐second‐order model. The Langmuir adsorption isotherm was found for PPy/TiO2, with the maximum adsorption capacity of 179.21 mg/g. The regeneration experiments showed that PPy/TiO2 could be successfully regenerated by simple alkali‐acid treatment. The adsorption efficiency of the regenerated PPy/TiO2 adsorbent for ARG was still greater than 90% after regeneration for 10 times. Additionally, the adsorption efficiency of PPy/TiO2 for the ARG effluent was still higher than 78% after adsorption–desorption for four times. It is expected that the PPy/TiO2 composite can be considered as a stable adsorbent for the removal of dye. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Luminescent Benzoquinolate‐Isocyanide Platinum(II) Complexes: Effect of Pt⋅⋅⋅Pt and π⋅⋅⋅π Interactions on their Photophysical Properties
Authors: Forniés Juan , Sicilia Violeta , Borja Pilar , Casas José M. , Díez Alvaro , Lalinde Elena , Larraz Carmen , Martín Antonio , Moreno M. Teresa
Published: September 2012

The neutral compounds [Pt(bzq)(CN)(CNR)] (R=tBu (1), Xyl (2), 2‐Np (3); bzq= benzoquinolate, Xyl=2,6‐dimethylphenyl, 2‐Np=2‐napthyl) were isolated as the pure isomers with a trans‐Cbzq,CNR configuration, as confirmed by 13C{1H} NMR spectroscopy in the isotopically marked [Pt(bzq)(13CN)(CNR)] (R=tBu (1′), Xyl (2′), 2‐Np (3′)) derivatives (δ13CCN≈110 ppm; 1J(Pt,13C)≈1425 Hz]. By contrast, complex [Pt(bzq)(C≡CPh)(CNXyl)] (4) with a trans‐Nbzq,CNR configuration, has been selectively isolated from [Pt(bzq)Cl(CNXyl)] (trans‐Nbzq,CNR) using Sonogashira conditions. X‐ray diffraction studies reveal that while 1 adopts a columnar‐stacked chain structure with Pt–Pt distances of 3.371(1) Å and significant π⋅⋅⋅π interactions (3.262 Å), complex 2 forms dimers supported only by short Pt⋅⋅⋅Pt (3.370(1) Å) interactions. In complex 4 the packing is directed by weak bzq⋅⋅⋅Xyl and bzq⋅⋅⋅C≡E (C, N) interactions. In solid state at room temperature, compounds 1 and 2 both show a bright red emission (ϕ=42.1 % 1, 57.6 % 2). Luminescence properties in the solid state at 77 K and concentration‐dependent emission studies in CH2Cl2 at 298 K and at 77 K are also reported for 1, 1·CHCl3, 2, 2', 2·CHCl3, 3, 4.
An overview of chromatin modifications
Authors: Fick Robert J. , Trievel Raymond C.
Published: September 2012

The last 15 years have witnessed tremendous progress in elucidating the roles of chromatin modifications in transcription regulation, DNA repair, replication, recombination, and other genomic processes. In this issue of Biopolymers, a series of reviews will summarize recent advances in our understanding of chromatin modifying enzymes and explore unresolved questions with respect to their regulation and functions in gene expression and other nuclear processes. © 2012 Wiley Periodicals, Inc. Biopolymers 99: 95–97, 2013.
Institutional Challenges of Applied and Workforce Baccalaureate Programs
Authors: Wagoner Richard L. , Ayon Carlos
Published: September 2012

This chapter identifies some of the challenges facing the applied and workforce baccalaureate. The authors seek not to argue against the baccalaureate but rather to identify concerns that need to be addressed in order to design and implement the degree effectively.
Graduate Education Issues and Challenges: Community College Applied and Workforce Baccalaureates
Authors: Floyd Deborah L. , Felsher Rivka A. , Catullo Linda
Published: September 2012

This chapter discusses challenges of the next steps along the baccalaureate degree articulation pathway: graduate education. The articulation of community college applied and workforce baccalaureate degrees with university graduate degrees is the next frontier in the community college baccalaureate movement.
The Use of Electrospray Mass Spectrometry to Determine Speciation in a Dynamic Combinatorial Library for Anion Recognition
Authors: Phillips Hazel I. A. , Chernikov Aleksey V. , Fletcher Nicholas C. , Ashcroft Alison E. , Ault James R. , Filby Maria H. , Wilson Andrew J.
Published: September 2012

The composition of a dynamic mixture of similar 2,2′‐bipyridine complexes of iron(II) bearing either an amide (5‐benzylamido‐2,2′‐bipyridine and 5‐(2‐methoxyethane)amido‐2,2′‐bipyridine) or an ester (2,2′‐bipyridine‐5‐carboxylic acid benzylester and 2,2′‐bipyridine‐5‐carboxylic acid 2‐methoxyethane ester) side chain have been evaluated by electrospray mass spectroscopy in acetonitrile. The time taken for the complexes to come to equilibrium appears to be dependent on the counteranion, with chloride causing a rapid redistribution of two preformed heteroleptic complexes (of the order of 1 hour), whereas the time it takes in the presence of tetrafluoroborate salts is in excess of 24 h. Similarly the final distribution of products is dependent on the anion present, with the presence of chloride, and to a lesser extent bromide, preferring three amide‐functionalized ligands, and a slight preference for an appended benzyl over a methoxyethyl group. Furthermore, for the first time, this study shows that the distribution of a dynamic library of metal complexes monitored by ESI‐MS can adapt following the introduction of a different anion, in this case tetrabutylammonium chloride to give the most favoured heteroleptic complex despite the increasing ionic strength of the solution.
Sterically‐Limited Self‐Assembly of Pt4 Macrocycles into Discrete Non‐covalent Nanotubes: Porous Supramolecular Tetramers and Hexamers
Authors: Frischmann Peter D. , Sahli Brian J. , Guieu Samuel , Patrick Brian O. , MacLachlan Mark J.
Published: September 2012

We report a template‐free strategy based on steric repulsion for the isolation of discrete columnar aggregates of macrocycles. Specifically, introduction of sterically‐demanding trityl‐derived substituents at the periphery of Pt4 Schiff base macrocycles limits the otherwise infinite one‐dimensional columnar aggregation to discrete tetrameric and hexameric assemblies. Single crystal X‐ray diffraction studies of these compounds reveal discrete nanotubes of finite length that pack inefficiently resulting in three‐dimensional networks of interconnected void space. The discrete assemblies were studied by N2 adsorption and show enhanced surface area when stacked. In the absence of bulky substituents the macrocycles are nonporous. This strategy for engineering discrete supramolecular macrocyclic aggregates may be generalized to other columnar assembling systems.
Reversed Assembly of Dyes in an RNA Duplex Compared with Those in DNA
Authors: Fujii Taiga , Urushihara Masaaki , Kashida Hiromu , Ito Hiroshi , Liang Xingguo , Yagi‐Utsumi Maho , Kato Koichi , Asanuma Hiroyuki
Published: September 2012

We prepared reversed dye clusters by hybridizing two RNA oligomers, each of which tethered dyes (Methyl Red, 4′‐methylthioazobenzene, and thiazole orange) on D‐threoninols (threoninol nucleotides) at the center of their strands. NMR spectroscopic analyses revealed that two dyes from each strand were axially stacked in an antiparallel manner to each other in the duplex, and were located adjacent to the 3′‐side of a natural nucleobase. Interestingly, this positional relationship of the dyes was completely the opposite of that assembled in DNA that we reported previously: dyes in DNA were located adjacent to the 5′‐side of a natural nucleobase. This observation was also consistent with the circular dichroism of dimerized dyes in which the Cotton effect of the dyes (i.e., the winding properties of two dyes) was inverted in RNA relative to that in DNA. Further spectroscopic analyses revealed that clustering of the dyes on RNA duplexes induced distinct hypsochromicity and narrowing of the band, thus demonstrating that the dyes were axially stacked (i.e., H‐aggregates) even on an A‐type helix. On the basis of these results, we also prepared heterodimers of a fluorophore (thiazole orange) and quencher (Methyl Red) in an RNA duplex. Fluorescence from thiazole orange was found to be strongly quenched by Methyl Red due to the excitonic interaction, so that the ratio of fluorescent intensities of the RNA–thiazole orange conjugate with and without its complementary strand carrying a quencher became as high as 27. We believe that these RNA–dye conjugates are potentially useful probes for real‐time monitoring of RNA interference (RNAi) mechanisms.
Illuminating the Mechanism of the Borane‐Catalyzed Hydrosilylation of Imines with Both an Axially Chiral Borane and Silane
Authors: Mewald Marius , Oestreich Martin
Published: September 2012

The reduction of CO groups with silanes catalyzed by electron‐deficient boranes follows a counterintuitive mechanism in which the SiH bond is activated by the boron Lewis acid prior to nucleophilic attack of the carbonyl oxygen atom at the silicon atom. The borohydride thus formed is the actual reductant. These steps were elucidated by using a silicon‐stereogenic silane, but applying the same technique to the related reduction of CN groups was inconclusive due to racemization of the silicon atom. The present investigation now proves by the deliberate combination of our axially chiral borane catalyst and axially chiral silane reagents (in both enantiomeric forms) that the mechanisms of these hydrosilylations are essentially identical. Unmistakable stereochemical outcomes for the borane/silane pairs show that both participate in the enantioselectivity‐determining hydride‐transfer step. These experiments became possible after the discovery that our axially chiral C6F5‐substituted borane induces appreciable levels of enantioinduction in the imine hydrosilylation.
ChemInform Abstract: Unique Catalysis of Gold Nanoparticles in the Chemoselective Hydrogenolysis with H2: Cooperative Effect Between Small Gold Nanoparticles and a Basic Support.
Authors: Noujima Akifumi , Mitsudome Takato , Mizugaki Tomoo , Jitsukawa Koichiro , Kaneda Kiyotomi
Published: September 2012

Gold nanoparticles on hydrotalcite act as a heterogeneous catalyst for the chemoselective hydrogenolysis of various allylic carbonates (I), (IV) to the corresponding terminal alkenes (II) without C—C double bond reduction.
ChemInform Abstract: Csp2—Csp2 Bond Formation via Lewis Acid/Ammonium Salt Cocatalyzed Tandem Addition and Oxidative Dehydrogenation Strategy: Alkenylation of Indoles with α,β‐Unsaturated Ketones.
Authors: Xiang Shi‐Kai , Wu Guolin , Zhang Bo , Cui Yuxin , Jiao Ning
Published: September 2012

An alkenylation of indoles at C‐3 is developed through tandem addition and oxidative dehydration.
ChemInform Abstract: Novel Synthetic Methodologies. Part 10. A New Iodine‐Catalyzed Regioselective Synthesis of Xanthene Synthons.
Authors: Sashidhara Koneni V. , Kumar Abdhesh , Dodda Ranga Prasad , Kumar Bikash
Published: September 2012

The synthesis of p‐condensed xanthenes (III) is achieved by iodine catalyzed condensation of dialdehydes (I) with naphthols (II) in the presence of I2.
ChemInform Abstract: Cobalt‐Catalyzed Asymmetric Addition of Silylacetylenes to Oxa‐ and Azabenzonorbornadienes.
Authors: Sawano Takahiro , Ou Keiyu , Nishimura Takahiro , Hayashi Tamio
Published: September 2012

Noteworthy, alkynes, such as phenylacetylene or octyne fail to give the title reaction.
ChemInform Abstract: Deleterious Reactions of Aggregate with Alkalis in Concrete
Authors: Broekmans Maarten A. T. M.
Published: September 2012

Review: 595 refs.
ChemInform Abstract: Recent Advances in the Total Synthesis of Cyclopropane‐Containing Natural Products
Authors: Chen David Y.‐K. , Pouwer Rebecca H. , Richard Jean‐Alexandre
Published: September 2012

Review: ca. 100 refs.
Access to Enantiomerically Pure cis‐ and trans‐β‐Phenylproline by High‐Performance Liquid Chromatography Resolution
Authors: Fatás Paola , Gil Ana M. , Calaza M. Isabel , Jiménez Ana I. , Cativiela Carlos
Published: September 2012

The preparation of all four stereoisomers of the proline analog that bears a phenyl group attached to the β carbon either cis or trans to the carboxylic acid (cis‐ and trans‐β‐phenylproline, respectively) has been addressed. The methodology developed allows access to multigram quantities of the target amino acids in enantiomerically pure form and suitably protected for use in peptide synthesis. Racemic precursors of cis‐β‐phenylproline and trans‐β‐phenylproline were prepared from easily available starting materials and subjected to high‐performance liquid chromatography enantioseparation. Semipreparative columns (250 × 20 mm) containing chiral stationary phases based on amylose (Chiralpak IA) (Daicel‐Chiral Technologies Europe, Illkirch, France) or cellulose (Chiralpak IC) were used respectively for the resolution of the cis‐ and trans‐β‐phenylproline precursors. Chirality, 24:1082‐1091, 2012. © 2012 Wiley Periodicals, Inc.
A universal nanoparticle cell secretion capture assay
Authors: Fitzgerald Wendy , Grivel Jean‐Charles
Published: September 2012

Secreted proteins play an important role in intercellular interactions, especially between cells of the immune system. Currently, there is no universal assay that allows a simple noninvasive identification and isolation of cells based on their secretion of various products. We have developed such a method. Our method is based on the targeting, to the cell surface, of heterofunctional nanoparticles coupled to a cell surface‐specific antibody and to a secreted protein‐specific antibody, which captures the secreted protein on the surface of the producing cell. Importantly, this method does not compromise cellviability and is compatible with further culture and expansion of the secreting cells. Published 2012 Wiley‐Periodicals, Inc.
Evaluation of calcineurin/NFAT inhibitor selectivity in primary human Th cells using bar‐coding and phospho‐flow cytometry
Authors: Frischbutter Stefan , Schultheis Katherine , Pätzel Michael , Radbruch Andreas , Baumgrass Ria
Published: September 2012

Small molecular inhibitors are excellent tools for manipulating cell reactions. They are widely used in scientific research to study molecular mechanisms of cells under physiological and pathophysiological conditions as well as in clinical applications to treat patients. However, their selectivity is often not well known. Moreover, it can vary according to cell types and the analysis methods used. Therefore, it is usually not possible to make comparisons between the data presented in the literature. Here we analyzed the selectivity of five chosen inhibitors of calcineurin/NFAT activation under the same conditions. Using a combination of fluorescent cell barcoding and phospho‐specific flow cytometry we studied the inhibition of activation of NF‐κBp65 and MAPK pathways in stimulated primary human Th cells. This semi‐high throughput approach enabled us to demonstrate that (i) CsA and NCI3 are around 5 to 10‐ and 20‐fold less potent, respectively, at inhibiting phosphorylation of NF‐κBp65 and p38 than activation of NFAT, (ii) AM404 is at least 15‐fold selective for NFAT but already toxic at concentrations above 40 μM, (iii) INCA6 is not selective at all, and (iv) BTP1 is at least 100‐fold selective for inhibition of NFAT activation relative to NF‐κBp65, p38 and ERK1/2 phosphorylation. Altogether, our results not only show the applicability of a semi‐high throughput inhibitor test system but also that BTP1 is the most selective inhibitor of calcineurin/NFAT activation among the studied inhibitors under the used conditions.
Modular Synthesis of Planar‐Chiral para‐Substituted Paracyclophanes by Double Suzuki Coupling
Authors: Cakici Murat , Bräse Stefan
Published: September 2012

The first synthesis of enantiomerically pure 4,7‐paracyclophane ditriflate starting from a quinone was reported. Using this molecule, mono‐ or dicoupling with boronic acids delivered enantiomerically pure arylparacyclophanes.
Synthesis and Aggregation Properties of Polycationic Perylenetetracarboxylic Acid Diimides
Authors: Schönamsgruber Jörg , Schade Boris , Kirschbaum Rolf , Li Jing , Bauer Walter , Böttcher Christoph , Drewello Thomas , Hirsch Andreas
Published: September 2012

The synthesis and structural characterization of a first family of dendronized polycationic perylenetetracarboxylic acid diimides (PDIs) 7, 8, and 10 is reported. They were obtained by amide coupling reactions of pyridinium salt head groups with terminal carboxylic groups of Newkome‐dendron‐type functionalized PDIs. Resulting pyridinium‐terminated PDIs 7, 8, and 10 are highly water‐soluble, independent of the pH value. This is due to 6, 18, and 9 permanent positive charges, respectively. PDIs 7 containing the smaller first‐generation dendrons exhibit a pronounced aggregation behavior in water. This was studied by absorption and fluorescence spectroscopy, by pulsed‐gradient spin‐echo (PGSE, DOSY) NMR measurements, and by cryo‐transmission electron microscopy (cryo‐TEM). The counterparts containing the bulkier second‐generation dendrons hamper aggregation, and as a consequence intermolecular π–π stacking interactions between the perylene cores is suppressed.
BaTiO3‐based nanolayers and nanotubes: First‐principles calculations
Authors: Evarestov Robert A. , Bandura Andrei V. , Kuruch Dmitrii D.
Published: September 2012

The first‐principles calculations using hybrid exchange‐correlation functional and localized atomic basis set are performed for BaTiO3 (BTO) nanolayers and nanotubes (NTs) with the structure optimization. Both the cubic and the ferroelectric BTO phases are used for the nanolayers and NTs modeling. It follows from the calculations that nanolayers of the different ferroelectric BTO phases have the practically identical surface energies and are more stable than nanolayers of the cubic phase. Thin nanosheets composed of three or more dense layers of (0 1 0) and (0 1
$\bar 1$) faces preserve the ferroelectric displacements inherent to the initial bulk phase. The structure and stability of BTO single‐wall NTs depends on the original bulk crystal phase and a wall thickness. The majority of the considered NTs with the low formation and strain energies has the mirror plane perpendicular to the tube axis and therefore cannot exhibit ferroelectricity. The NTs folded from (0 1
$\bar 1$) layers may show antiferroelectric arrangement of TiO bonds. Comparison of stability of the BTO‐based and SrTiO3‐based NTs shows that the former are more stable than the latter. © 2012 Wiley Periodicals, Inc.
Correlation of sonographic features of invasive ductal mammary carcinoma with age, tumor grade, and hormone‐receptor status
Authors: Aho Michael , Irshad Abid , Ackerman Susan J. , Lewis Madelene , Leddy Rebecca , Pope Thomas L. , Campbell Amy S. , Cluver Abbie , Wolf Bethany J. , Cunningham Joan E.
Published: September 2012

Purpose.

To determine whether presenting sonographic features of invasive ductal carcinomas (IDC) are associated with patient age, tumor histologic grade, and hormonal receptor status.

Methods.

Sonographic features of 101 consecutive cases of IDC seen at ultrasound were retrospectively assessed based on the BI‐RADS criteria of posterior acoustic appearance, tumor margins, and echogenicity. Associations between sonographic features and tumor characteristics were statistically evaluated with attention to patient age.

Results.

IDC with shadowing compared with unchanged posterior acoustic appearance were significantly more likely to be of low histologic grade (Odds Ratio [OR] = 5.00; p < 0.05) and estrogen receptor (ER) ‐positive (OR = 10.00; p < 0.05). Conversely, posterior enhancement was associated with ER‐negative status (OR = 4.45; p < 0.01), particularly among patients younger than 60 years of age (OR = 5.36, p < 0.05). Circumscribed tumors were more often high grade, particularly among older women (p < 0.01), and hormone receptor‐‐negative regardless of age group. Among older women, tumors with mixed echogenicity tended to be high grade and progesterone receptor‐‐negative (p values < 0.05). Noncircumscribed borders were observed for all tumors with posterior shadowing, and 97% of such tumors were also ER positive.

Conclusions.

Sonographic features were significantly associated with tumor grade and hormone receptor status, with some differences based on patient age. Specifically, the presence of posterior shadowing was associated with lower histologic grade and ER‐positive status, especially in older patients. In contrast, we found that posterior acoustic enhancement was more commonly associated with ER‐negative status, especially in younger patients. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound 2013
Prenatal diagnosis of 22q11.2 deletion syndrome in twin pregnancy: A case report
Authors: Gul Ahmet , Gungorduk Kemal , Turan Isil , Yildirim Gokhan , Gedikbasi Ali , Özdemir Aykut
Published: September 2012

Chromosome 22q11.2 deletion syndrome is a common genetic disorder, also known as DiGeorge syndrome. It occurs in approximately 1:4,000 births, and the incidence is increasing due to affected parents bearing their own affected children. We report the prenatal diagnosis of 22q11.2 deletion syndrome by fluorescence in situ hybridization in twin fetuses having tetralogy of Fallot with absent pulmonary valve. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound 41:6–9, 2013
Interaction of serum amyloid A with human cystatin C—identification of binding sites
Authors: Spodzieja Marta , Szymańska Aneta , Kołodziejczyk Aleksandra , Prądzińska Martyna , Maszota Martyna , Stefanowicz Piotr , Szewczuk Zbigniew , Grubb Anders , Czaplewska Paulina
Published: September 2012

Serum amyloid A (SAA) is a multifunctional acute‐phase protein whose natural role seems to be participation in many physiologic and pathological processes. Prolonged increased SAA level in a number of chronic inflammatory and neoplastic diseases gives rise to reactive systemic amyloid A amyloidosis, where the N‐terminal 76‐amino acid residue‐long segment of SAA is deposited as amyloid fibrils. Recently, a specific interaction between SAA and the ubiquitous inhibitor of cysteine proteases—human cystatin C (hCC)—has been described. Here, we report further evidence corroborating this interaction, and the identification of the SAA and hCC binding sites in the SAA–hCC complex, using a combination of selective proteolytic excision and high‐resolution mass spectrometry. The shortest binding site in the SAA sequence was determined as SAA(86–104), whereas the binding site in hCC sequence was identified as hCC(96–102). Binding specificities of both interacting sequences were ascertained by affinity experiments (ELISA) and by registration of mass spectrum of SAA–hCC complex. Copyright © 2012 John Wiley & Sons, Ltd.
Modified cine inversion recovery pulse sequence for the quantification of myocardial T1 and gadolinium partition coefficient
Authors: Milanesi Matteo , Barison Andrea , Positano Vincenzo , Masci Pier Giorgio , De Marchi Daniele , Marinelli Luca , Hardy Christopher J. , Foo Thomas K. , Landini Luigi , Lombardi Massimo
Published: September 2012

Purpose:

To optimize and validate a modified cine inversion recovery sequence (MCine‐IR) for myocardial T1 quantification and gadolinium partition coefficient (λGd) estimation at 1.5 T.

Materials and Methods:

The original version of the cine inversion recovery sequence was modified to allow fully transverse magnetization recovery between two successive inversion pulses. Sixty heart phases were acquired from a number of heart cycles determined on a patient heart rate basis. Phantom studies were carried out to find the optimal effective TR for myocardial and blood pool T1 quantifications in pre‐ and postcontrast studies. Four patients with myocardial infarct (MI) and 22 dilated cardiomyopathy (DCM) were investigated, as well as 11 healthy subjects used as controls.

Results:

Effective TR was identified to be 5000 msec and 2000 msec, respectively, for pre‐ and postcontrast studies. A longer precontrast (948 ± 102 msec) and shorter postcontrast (348 ± 27 msec) T1 in ischemic patients relative to DCM (815 ± 98 msec, P = 0.03 and 409 ± 42 msec, P = 0.001) were noted in delayed enhancement (DE) areas. In MI patients λGd resulted higher than in DCM in DE areas (609 ± 167 vs. 422 ± 52, P = 0.01) but lower in segments not exhibiting DE (355 ± 100 vs. 398 ± 54, P = 0.02).

Conclusion:

It was feasible to measure T1 and λGd with MCine‐IR and the results were in good agreement with the literature. J. Magn. Reson. Imaging 2013;37:109–118. © 2012 Wiley Periodicals, Inc.
Time‐resolved MR venography of the pulmonary veins precatheter‐based ablation for atrial fibrillation
Authors: Schonberger Michael , Usman Asad , Galizia Maurizio , Popescu Andrada , Collins Jeremy , Carr James C.
Published: September 2012

Purpose:

To evaluate time‐resolved magnetic resonance angiography (TR‐MRA) of the pulmonary venous circulation using the time‐resolved angiography with interleaved stochastic trajectories (TWIST) method and compare it with the more commonly used conventional contrast‐enhanced magnetic resonance angiography (CE‐MRA) approach in atrial fibrillation patients referred for preablation pulmonary vein mapping.

Materials and Methods:

This study was approved by the Institutional Review Board. Twenty‐six patients (15 males; age 59.6 ± 12.7 years) referred for preablation pulmonary vein mapping underwent both conventional CE‐MRA and TR‐MRA with TWIST. Imaging was performed on a 1.5 T (Magnetom Avanto, Siemens Healthcare, Erlangen, Germany) MRI scanner. Source partition and maximum intensity projection (MIP) images were evaluated retrospectively. For quantitative analysis, pulmonary vein ostium orthogonal dimensions were measured using double oblique multiplanar reformatting. The results were analyzed using paired t‐tests, Lin's concordance correlation coefficient, and Bland–Altman plots. For qualitative analysis, both source partition images and MIP images were assessed by two observers (A.P. and M.G.). The presence of common ostiums or accessory veins was recorded and analyzed using unweighted Cohen's kappa. Pulmonary vein conspicuity was scored on a scale of 1–4 (1 = poor, 2 = fair, 3 = good, 4 = excellent) and analyzed using paired t‐tests, intraclass correlation coefficients, and quadratic weighted kappa statistics.

Results:

Orthogonal venous diameters were comparable for both TR‐MRA and conventional CE‐MRA (1.34 ± 0.37 vs. 1.38 cm ± 0.36, respectively). Results of paired t‐tests, Lin's concordance correlation coefficient, and Bland–Altman analysis revealed relatively close comparison between methods. The magnitude of the mean difference for any of the statistical comparisons did not exceed 0.10 cm. The visualization of variant pulmonary vein anatomy was very similar for both techniques. Agreement between techniques was determined to be “good” to “very good” (κ = 0.78–0.85). Conspicuity scores for each pulmonary vein were also very close. Paired t‐tests, intraclass correlation coefficients, and quadratic weighted kappa statistics all revealed strong agreement between methods.

Conclusion:

TR‐MRA using TWIST produces comparable anatomic images and pulmonary venous dimensions to the more widely used CE‐MRA technique. Additionally, the TWIST technique improves arterio‐venous separation, does not need exact bolus timing, requires less gadolinium, and gives additional information on vein perfusion. J. Magn. Reson. Imaging 2013;37:127–137. © 2012 Wiley Periodicals, Inc.