bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectroscopic and Theoretical Study on Electronically Modified Chromophores in LOV Domains: 8‐Bromo‐ and 8‐Trifluoromethyl‐Substituted Flavins
Authors: Mansurova Madina , Simon Julian , Salzmann Susanne , Marian Christel M. , Gärtner Wolfgang
Published: March 2013

Two chemically synthesized flavin derivatives, 8‐trifluoromethyl‐ and 8‐bromoriboflavin (8‐CF3RF and 8‐BrRF), were photochemically characterized in H2O and studied spectroscopically after incorporation into the LOV domain of the blue light photoreceptor YtvA from Bacillus subtilis. The spectroscopic studies were paralleled by high‐level quantum chemical calculations. In solution, 8‐BrRF showed a remarkably high triplet quantum yield (0.97, parent compound riboflavin, RF: 0.6) and a small fluorescence quantum yield (0.07, RF: 0.27). For 8‐CF3RF, the triplet yield was 0.12, and the fluorescence quantum yield was 0.7. The high triplet yield of 8‐BrRF is due to the bromine heavy atom effect causing a stronger spin–orbit coupling. Theoretical calculations reveal that the decreased triplet yield of 8‐CF3RF is due to a smaller charge transfer and a less favorable energetic position of T2, required for intersystem crossing from S1 to T1, as an effect of the electron‐withdrawing CF3 group. The reconstitution of the LOV domain with the new flavins resulted in the typical LOV photochemistry, consisting of triplet state formation and covalent binding of the chromophore, followed by a thermal recovery of the parent state, albeit with different kinetics and photophysical properties.
Laccase‐Catalyzed CS and CC Coupling for a One‐Pot Synthesis of 1,4‐Naphthoquinone Sulfides and 1,4‐Naphthoquinone Sulfide Dimers
Authors: Wellington Kevin W. , Gordon Gregory E. R. , Ndlovu Lindelani A. , Steenkamp Paul
Published: March 2013

Oxidative CS and CC bond formation with aryl and alkyl thiols was catalyzed under mild conditions in a reaction vessel open to air at pH 4.5 in the presence of a commercial laccase (Novozym 51003 or Suberase) and a cosolvent (DMF) to afford 1,4‐naphthoquinone sulfides. Although both monothiolation and dithiolation of the 1,4‐naphthohydroquinone were accomplished, the latter was favored. In addition, unprecedented dimerization of monothiolated intermediates occurred through CC coupling. These commercial laccases provide a facile and a more environmentally friendly synthetic approach to both 1,4‐naphthoquinone sulfides and 1,4‐naphthoquinone sulfide dimers.
Compositional and Morphological Changes of Ordered PtxFey/C Oxygen Electroreduction Catalysts
Authors: Chen Liang , Chan Mickey C. Y. , Nan Feihong , Bock Christina , Botton Gianluigi A. , Mercier Patrick H. J. , MacDougall Barry R.
Published: March 2013

Changes in the O2 reduction activity (ORR) and structure of carbon‐supported catalysts upon electrochemical stress testing are investigated. Focus is placed on two alloy catalysts of nominal Pt3Fe/C and Pt3Fe2/C compositions. Energy dispersive X‐ray spectroscopy (EDXS) spot and line analyses reveal a dependence of the Fe composition on the particle size, particularly for the two as‐prepared catalysts. The catalyst particles are shown to have a Pt‐enriched shell and a PtxFey alloy core. Larger (>≈10 nm) particles are shown to have a higher Fe content that approaches the nominal composition, which suggests that the smaller (<≈6 nm) Pt catalyst particles are more difficult to alloy. High‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM), XRD, and SEM with EDXS show that Fe is lost gradually from the catalyst particles as a result of extensive potential (E)‐cycling. Changes upon E‐cycling are observed most clearly for the small (<3 nm) particles, in which Fe is almost entirely depleted. However, the catalytic ORR activities remain constant over an extensive cycling period for the PtxFey/C catalysts and the mass ORR activities decrease proportionally with Pt surface area (APt). The histograms before and after cycling are compared to observed changes in APt and are discussed in comparison to E‐holding experiments. It is concluded that the dissolution of Pt is a strong contributor for the observed decrease in APt and mass ORR activity for the PtxFey/C catalysts. The continuous transition between Pt oxide formation and its reduction to Pt metal is suggested to play a major role in the degradation of the PtxFey/C catalysts studied in this work.
Syntheses, Supramolecular Structures and Antibacterial Activities of Five Helical Transition Complexes with 5‐Chloro‐1‐phenyl‐1H‐pyrazole‐3,4‐dicarboxylic Acid
Authors: Liu Hong , Liu Chongbo , Gong Yunnan , Wang Yuhua , Wen Huiliang
Published: March 2013

Five new transition metal complexes [Cu(HL)2(H2O)2] (1), [Cu(HL)2(phen)] (2), [Cu(HL)2(H2O)]2(4,4′‐bipy) (3), [Zn(HL)2(H2O)2]·(4,4′‐bipy) (4), [Ag(HL)(4,4′‐bipy)]n (5), (H2L=5‐chloro‐1‐phenyl‐1H‐pyrazole‐3,4‐dicarboxylic acid, phen=1,10‐phenanthroline; 4,4′‐bipy=4,4′‐bipyridine) have been synthesized and characterized. Complexes 1, 2 and 4 exhibit monomeric structures, 3 shows a dinuclear structure, 5 displays 1D chain structure, and all extend to 3D supramolecular network via rich hydrogen bonds. Complexes 1, 2, 3, 5 comprise single helical chains, while complex 4 generates quadruple‐stranded helical chains. Furthermore, the antibacterial activities of the titled complexes against bacterial species, three Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis and Candida albicans) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) were studied and compared to the activities of free ligands by using the microdilution method.
External validation of a prognostic nomogram for overall survival in women with uterine leiomyosarcoma
Authors: Iasonos Alexia , Keung Emily Z. , Zivanovic Oliver , Mancari Rosanna , Peiretti Michele , Nucci Marisa , George Suzanne , Colombo Nicoletta , Carinelli Silvestro , Hensley Martee L. , Raut Chandrajit P.
Published: March 2013

BACKGROUND:

There is no validated system to identify prognostically distinct cohorts of women with uterine leiomyosarcoma (ULMS). By using an independent, pooled, multi‐institutional, international patient cohort, the authors validated a recently proposed ULMS nomogram.

METHODS:

The ULMS nomogram incorporated 7 clinical characteristics (age, tumor size, tumor grade, cervical involvement, locoregional metastases, distant metastases, and mitotic index (per 10 high‐power fields) to predict overall survival (OS) after primary surgery. Independent cohorts from 2 sarcoma centers were included. Eligible women, at minimum, underwent a hysterectomy for primary, locally advanced, or metastatic ULMS and received part of their care at 1 of the centers between 1994 and 2010.

RESULTS:

In total, 187 women with ULMS were identified who met the above criteria described above (median age, 51 years; median tumor size, 9 cm; median mitotic index, 20 per 10 high‐power fields). Tumors generally were high grade (88%), FIGO stage I or II (61%) without cervical involvement (93%) and without locoregional metastases (77%) or distant metastases (83%). The median OS and the 5‐year OS rate were 4.5 years (95% confidence interval, 3.2‐5.3 years) and 46%, respectively; and 65 women (35%) remained alive at last follow‐up. The nomogram concordance index was 0.67(standard error, 0.02), which was as high as the concordance index from the initial cohort used for nomogram development. The concordance between actual OS and nomogram predictions suggests excellent calibration because predictions were within 1% of actual 5‐year OS rates for patients with a predicted 5‐year OS of less than 0.68.

CONCLUSIONS:

The ULMS nomogram was externally validated using independent cohorts. These findings support the international use of the ULMS nomogram prognostic of OS in ULMS. Cancer 2013. © 2012 American Cancer Society.
Hospital volume is associated with survival but not multimodality therapy in Medicare patients with advanced head and neck cancer
Authors: Sharma Arun , Schwartz Stephen M. , Méndez Eduardo
Published: March 2013

BACKGROUND:

Given the complexity of management of advanced head and neck squamous cell carcinoma (HNSCC), this study hypothesized that high hospital volume would be associated with receiving National Comprehensive Cancer Network (NCCN) guideline therapy and improved survival in patients with advanced HNSCC.

METHODS:

The Surveillance, Epidemiology, and End Results (SEER)‐Medicare database was used to identify patients with advanced HNSCC. Treatment modalities and survival were determined using Medicare data. Hospital volume was determined by the number of patients with HNSCC treated at each hospital.

RESULTS:

There were 1195 patients with advanced HNSCC who met inclusion criteria. In multivariable analyses, high hospital volume was not associated with receiving multimodality therapy per NCCN guidelines (odds ratio = 1.02, 95% confidence interval = 0.66‐1.60), but showed a nearly significant inverse association with survival in a model adjusted for National Cancer Institute–designated cancer center status, age, sex, race, socioeconomic status, marital status, comorbidity, year of diagnosis, tumor site, and tumor stage (hazard ratio = 0.85, 95% confidence interval = 0.69‐1.04).

CONCLUSIONS:

Medicare patients with advanced HNSCC treated at high‐volume hospitals were not more likely to receive NCCN guideline therapy, but had nearly statistically significant better survival, when compared with patients treated at low‐volume hospitals. These results suggest that features of high‐volume hospitals other than delivery of NCCN guideline therapy influence survival. Cancer 2013. © 2013 American Cancer Society.
Prognostic impact of absolute lymphocyte counts at the end of remission induction in childhood acute lymphoblastic leukemia
Authors: Rubnitz Jeffrey E. , Campbell Patrick , Zhou Yinmei , Sandlund John T. , Jeha Sima , Ribeiro Raul C. , Inaba Hiroto , Bhojwani Deepa , Relling Mary V. , Howard Scott C. , Campana Dario , Pui Ching‐Hon
Published: March 2013

BACKGROUND

Absolute lymphocyte counts (ALC) during treatment have been associated with outcome in children and adults with hematologic malignancies. However, the impact of ALC relative to that of other prognostic factors on the outcome of children with acute lymphoblastic leukemia (ALL) treated in recent trials is unknown.

METHODS

Outcomes of 399 patients aged ≤18 years with newly diagnosed ALL who were enrolled in the Total Therapy XV study at St. Jude Children's Research Hospital were analyzed according to ALC at the end of remission induction therapy.

RESULTS

An ALC ≥500 cells/μL was significantly more prevalent among patients with B‐lineage ALL, in those with favorable presenting features, and in those who achieved negative minimal residual disease (MRD) status on day 43 of treatment. Both overall survival (OS) and event‐free survival (EFS) were superior among patients with higher ALC, but only the association with OS was statistically significant in a univariate analysis. In multivariable analyses, ALC was not a significant predictor of outcome after controlling for age, leukocyte count, lineage, risk group, and MRD status at the end of induction (P > .1 for all comparisons). However, among MRD‐negative patients, those with low ALC had a 5‐year OS rate of 84.2% ± 8.9% versus 97.3% ± 1.0% for patients with higher ALC (P = .036).

CONCLUSIONS

ALC at the end of induction is related to favorable presenting features and good initial treatment response but does not independently predict outcome in the context of contemporary, MRD‐guided therapy. Cancer 2013;119:2061–2066. © 2013 American Cancer Society.
Self‐organizing market structures, system dynamics, and urn theory
Authors: Buendía Fernando
Published: March 2013

Using data from Fortune Magazine's 500 American largest corporations from 1955 to 2010, this article shows that firm sizes at national and industrial level are highly skew but not Zipf‐distributed. It also argues that, while self‐organizing industrial structures of this kind are due to increasing returns and hard to describe with conventional theories, system dynamics and urn theory are equipped with adequate tools to analyze them.
Fine‐needle aspiration cytology of orbital and eyelid lesions
Authors: Agrawal Pallavi , Dey Pranab , Lal Anupam
Published: March 2013

Fine‐needle aspiration cytology (FNAC) of orbital lesions is now increasingly popular. Because of its unique location and the occurrence of varieties of lesions, diagnosis of orbital lesion is a challenge to the cytopathologists. FNAC of orbital and eyelid tumors is a suitable diagnostic technique that necessitates close co‐operation between the ophthalmologist and pathologist. No radical procedure should be planned on the basis of FNAC, but it allows the diagnosis of a new primary lesion or the recurrence or metastasis of a tumor and can be done to identify lesions that require either specific medical therapy, as in nonresectable, inflammatory, and lymphoid tumors, or limited surgery for benign resectable neoplasms. With the help of various ancillary techniques a definitive diagnosis is possible on orbital and adnexal lesions. It is essential to have a detailed knowledge on the FNAC of these lesions and their potential pitfalls. In this present review, we have discussed various orbital lesions, their clinical presentations, cytomorphology, and ancillary techniques to confirm the diagnosis. Diagn. Cytopathol. 2013;41:1000–1011. © 2013 Wiley Periodicals, Inc.
Rhenium Complexes with a Pyridinyl‐Naphthyridine Ligand: Synthesis, Characterization, and Catalytic Activity
Authors: Su Tzu‐Chieh , Liu Yi‐Hung , Peng Shie‐Ming , Liu Shiuh‐Tzung
Published: March 2013

Treatment of [Re2(CO)8(CH3CN)2] with 2,7‐dipyridinyl‐1,8‐naphthyridine (bpnp) thermally provided mononuclear [(N,N′‐bpnp)Re(CO)3Cl] (1). Further reaction of 1 with rhenium carbonyls yielded ortho‐metallation dinuclear rhenium complex 2. Both complexes were characterized by spectroscopic analyses and single‐crystal X‐ray determination. Complex 1 also reacted with [PdMeCl(COD)] and [Ir(COD)Cl]2 by means of ortho‐metallation to yield the corresponding heterodinuclear species. Complex 2 appears to be an excellent precatalyst to promote the insertion of terminal alkynes into acetoacetates, which subsequently undergo cyclization to form 2‐pyranones.
Iron‐Catalyzed Reduction of Carboxylic Esters to Alcohols
Authors: Junge Kathrin , Wendt Bianca , Zhou Shaolin , Beller Matthias
Published: March 2013

A novel catalytic system formed from Fe(stearate)2/NH2CH2CH2NH2 and polymethylhydrosiloxane was directly developed for the hydrosilylation of carboxylic acid esters to alcohols. The catalytic method exhibits broad substrate scope, including 20 aliphatic, aromatic, and heterocyclic esters. The corresponding alcohols are obtained in moderate to very good yields.
Stereoselective Synthesis of Substituted 1,4‐Oxazepanes by Intramolecular Reductive Etherification
Authors: Gharpure Santosh J. , Prasad J. V. K.
Published: March 2013

A facile and general strategy is developed for the stereoselective synthesis of substituted 1,4‐oxazepane derivatives through an intramolecular reductive etherification reaction. The effects of the substituents present on the oxonium ion and the position of this ion with respect to the nitrogen atom on the yield and selectivity of the reaction are also studied.
Electrochemical Performance of All‐Solid‐State Li/S Batteries with Sulfur‐Based Composite Electrodes Prepared by Mechanical Milling at High Temperature
Authors: Nagao Motohiro , Hayashi Akitoshi , Tatsumisago Masahiro
Published: March 2013

Sulfur–nanocarbon composites were prepared by mechanical milling at high temperature (155 °C), and the electrochemical performance of all‐solid‐state Li/S batteries was investigated with Li2S–P2S5 solid electrolytes . We aimed to increase the sulfur content in the sulfur‐based composite electrodes to enhance the energy density in the Li/S batteries. The composites included 50 wt % sulfur, which is twice as high as that in the all‐solid‐state Li/S batteries that use sulfide‐based solid electrolytes reported to date, and high‐temperature mechanical milling resulted in a small sulfur particle size with a large contact area between the particles. The improved composites are mainly responsible for the excellent cyclability (1050 mAh g−1 for 50 cycles), high gravimetric energy density (1007 Wh kg−1), and good rate capability of the assembled batteries. These composites are promising positive‐electrode materials for rechargeable Li/S batteries with high energy density. This approach of mechanical milling at high temperature is widely applicable and can be extended to a variety of materials in versatile energy devices as well as rechargeable lithium batteries.
Optimal Economic Design of an Extractive Distillation Process for Bioethanol Dehydration
Authors: Kiss Anton A. , Ignat Radu M.
Published: March 2013

The large‐scale production of bioethanol fuel requires energy‐demanding distillation steps to concentrate the diluted product streams from the fermentation step and to overcome the azeotropic behavior of the ethanol‐water mixture. The conventional separation sequence consists of three distillation columns performing several tasks with high energy penalties: preconcentration of ethanol (PDC), extractive distillation (EDC) and solvent recovery (SRC). It is remarkable that almost all papers on this topic focus on the azeotropic separation only, neglecting the preconcentration step. The energy usage in the PDC increases as the distillate composition gets closer to the azeotrope, and the energy requirements in the EDC and SRC units decrease as the input stream to the EDC becomes richer in ethanol and vice versa. In this study we optimize the economics and energy consumption of a PDC as a function of the distillate composition, a fundamental issue that was not investigated before. Simulations were conducted using Aspen Plus to investigate how this parameter affects the energy usage and investment costs of the complete system. This procedure applies as well to other processes that contain a preconcentration column (e.g., extractive and azeotropic distillation). The optimal economic conditions are reached at a distillate concentration of 91 wt % (80 mol %) ethanol, for which the specific energy consumption is 2.11 kWh (7596 kJ) per kg ethanol.
Habitat-specific foraging and sex determine mercury concentrations in sympatric benthic and limnetic ecotypes of threespine stickleback
Authors: Willacker James J. , von Hippel Frank A. , Ackerly Kerri L. , O'Hara Todd M.
Published: March 2013

Mercury (Hg) is a widespread environmental contaminant known for the neurotoxicity of its methylated forms, especially monomethylmercury, which bioaccumulates and biomagnifies in aquatic food webs. Mercury bioaccumulation and biomagnification rates are known to vary among species utilizing different food webs (benthic vs limnetic) within and between systems. The authors assessed whether carbon and nitrogen stable isotope values and total Hg (THg) concentrations differed between sympatric benthic and limnetic ecotypes and sexes of threespine stickleback fish (Gasterosteus aculeatus) from Benka Lake, Alaska, USA. The mean THg concentration in the limnetic ecotype was significantly higher (difference between benthic and limnetic means equals 26 mg/kg dry wt or 16.1%) than that of the benthic ecotype. Trophic position and benthic carbon percentage utilized were both important determinants of THg concentration; however, the 2 variables were of approximately equal importance in females, whereas trophic position clearly explained more of the variance than benthic carbon percentage in males. Additionally, strong sex effects (mean difference between females and males equals 45 mg/kg dry wt or 29.4%) were observed in both ecotypes, with female fish having lower THg concentrations than males. These results indicate that trophic ecology and sex are both important determinants of Hg contamination even within a single species and lake and likely play a role in governing Hg concentrations in higher trophic levels. Environ Toxicol Chem 2013;32:1623–1630. © 2013 SETAC
Toxicokinetics of polybrominated diphenyl ethers across life stages in the northern leopard frog (Lithobates pipiens)
Authors: Cary Tawnya L. , Karasov William H.
Published: March 2013

Polybrominated diphenyl ethers (PBDEs), a class of flame retardants, are bioaccumulative toxins that can biomagnify in food webs. However, little is known about the toxicokinetics of total and congener-specific BDEs in lower vertebrates. The authors exposed northern leopard frog (Lithobates (Rana) pipiens) tadpoles to diets containing DE-71 (a pentabromodiphenyl ether mixture (0 ng/g as control, 71.4 ng/g, and 634 DE-71 ng/g wet mass)) for 50 d, followed by a period of depuration during which they were fed only undosed (control) food. After 28 d, tadpoles eliminated over 94% of the ΣPBDEs from their tissues (t½ = 5.9 ± 1.9 d) with no significant differences in elimination rates for the predominant congeners. Elimination of BDE-99 was independent of dose, indicating first-order kinetics. It did not fit a biexponential model significantly better than a monoexponential model, indicating single-compartment elimination. To compare developmental life-stage kinetics following larval exposure, the authors collected individuals at the beginning and end of metamorphosis and at 70 d postmetamorphosis. During metamorphosis, total-body residues per individual did not significantly change, implying little to no elimination. After 70 d, juvenile frogs eliminated 89.7% of the ΣPBDEs from their tissues, and BDE-47 was eliminated at a faster rate (t½= 17.3 d) than BDE-99 and BDE-100 (t½ = 63.0 d and 69.3 d, respectively). Because the kinetics of PBDEs in L. pipiens differed among life stages, developmental life stage—especially for species that undergo metamorphosis—should be considered when determining the toxicity of persistent organic pollutants. Environ Toxicol Chem 2013;32:1631–1640. © 2013 SETAC
Charakteristische Bodenkennwerte der Torfe und Mudden Mecklenburg‐Vorpommerns zur Berechnung von Primärsetzungen
Authors: Koepke Christian , Saathoff Fokke
Published: March 2013

Die Festlegung charakteristischer Bodenkennwerte organischer Böden ist nach wie vor mit großen Unsicherheiten behaftet, da dabei u. a. auch der erhebliche Einfluss des veränderlichen äußeren Spannungszustandes berücksichtigt werden muss. Auf Grundlage durchgeführter eindimensionaler Kompressionsversuche und Durchströmungsversuche an Torfen und Mudden Mecklenburg‐Vorpommerns wurden daher Korrelationen der für analytische Berechnungen notwendigen Bodenkennwerte zu den relativ einfach zu bestimmenden Bezugsparametern Wassergehalt und Porenzahl ermittelt. Dabei fand die spannungsabhängige Formulierung des Steifemoduls nach OHDE Berücksichtigung. Für die Ermittlung des spannungsabhängigen Wasserdurchlässigkeitsbeiwerts wurde durch die Verfasser ein analoger Ansatz formuliert. Die ermittelten Korrelationen wurden mit vorliegenden Literaturangaben verglichen und anhand baubegleitend durchgeführter Messungen validiert. Zum jetzigen Kenntnisstand können die Korrelationen als plausibel und für bautechnische Zwecke hinreichend genau eingestuft werden. Eine Anwendung und Überprüfung der Ergebnisse im Rahmen künftiger Bauvorhaben wäre aus Sicht der Verfasser wünschenswert.

Characteristic soil parameters of peat and mud of Mecklenburg‐Western Pomerania for the calculation of primary settlements. The specification of characteristic soil parameters for organic soils is still tainted with uncertainties because among other things the influence of the changing stress level of the surrounding soil has to be taken into account. Therefore one‐dimensional compression tests and flow tests were carried out for the peats and muds of Mecklenburg‐Western Pomerania. Based on the test results correlations for the characteristic soil parameters for the calculation of primary settlements were formulated that refer to the water content and the void ratio. In regard of the stress‐dependency of the oedometric modulus the formulation of OHDE was used. For the coefficient of water permeability a similar formulation was determined by the authors. The correlations were compared to literature and validated by field measurements. According to the current state of knowledge the correlations can be considered plausible and accurate for geotechnical design. The results should be used and revised within upcoming projects.
The stability of a tunnel face with a free span and a non‐uniform support
Authors: Anagnostou Georgios , Perazzelli Paolo
Published: March 2013

We investigate the effects of the support pressure distribution and of the free unsupported span on the stability of the tunnel face by means of limit equilibrium computations, which are based upon the so‐called method of slices. Design equations and diagrams are introduced for the estimation of the necessary support pressure taking into account these effects assuming a linear pressure distribution. Furthermore, the errors introduced by the common assumption of support pressure uniformity are discussed for the typical distributions of face support pressure in tunnelling by slurry shields, EPB shields and compressed air shields. The error is less than 10% in the case of closed‐shield tunnelling but may be significant in the case of face reinforcement.

Der Einfluss der Stützdruckverteilung und der freien Spannweite auf die Stabilität der Tunnelortsbrust. Im vorliegenden Beitrag wird untersucht, in welchem Maß sich der erforderliche Stützdruck im Vorhandensein einer freien Spannweite zwischen Ausbruchsicherung und Ortsbrust erhöht. Ferner wird der Effekt der Verteilung des Stützdrucks unter der Annahme eines linearen Verlaufs quantifiziert. Das zugrunde liegende Berechnungsmodell untersucht das Grenzgleichgewicht eines Bruchmechanismus nach der sogenannten Lamellenmethode. Die Berechnungsergebnisse werden in Form von Bemessungsformeln und Diagrammen dargestellt. Ferner wird der Fehler der gängigen vereinfachenden Annahme eines gleichmäßig verteilten Stützdrucks für typische Problemstellungen diskutiert. Der Fehler beträgt weniger als 10% im Fall von geschlossenen Schildvortrieben (Erddruck‐, Flüssigkeits‐ oder Druckluftstützung), kann aber im Fall einer Ortsbrustbewehrung sehr groß und auf der unsicheren Seite sein.
Satellite observations of desert dust‐induced Himalayan snow darkening
Authors: Gautam Ritesh , Hsu N. Christina , Lau William K.‐M. , Yasunari Teppei J.
Published: March 2013

The optically thick aerosol layer along the southern edge of the Himalaya has been subject of several recent investigations relating to its radiative impacts on the South Asian summer monsoon and regional climate forcing. Prior to the onset of summer monsoon, mineral dust from southwest Asian deserts is transported over the Himalayan foothills on an annual basis. Episodic dust plumes are also advected over the Himalaya, visible as dust‐laden snow surface in satellite imagery, particularly in western Himalaya. We examined spectral surface reflectance retrieved from spaceborne MODIS observations that show characteristic reduction in the visible wavelengths (0.47 µm) over western Himalaya, associated with dust‐induced solar absorption. Case studies as well as seasonal variations of reflectance indicate a significant gradient across the visible (0.47 µm) to near‐infrared (0.86 µm) spectrum (VIS‐NIR), during premonsoon period. Enhanced absorption at shorter visible wavelengths and the resulting VIS‐NIR gradient is consistent with model calculations of snow reflectance with dust impurity. While the role of black carbon in snow cannot be ruled out, our satellite‐based analysis suggests the observed spectral reflectance gradient dominated by dust‐induced solar absorption during premonsoon season. From an observational viewpoint, this study underscores the importance of mineral dust deposition toward darkening of the western Himalayan snow cover, with potential implications to accelerated seasonal snowmelt and regional snow albedo feedbacks.
Impact of meridional winds on equatorial spread F: Revisited
Authors: Huba J. D. , Krall J.
Published: March 2013

The impact of meridional winds on the onset and evolution of equatorial spread F (ESF) is studied using the NRL ionosphere model SAMI3/ESF. The prevailing belief is that meridional winds have a stabilizing effect on the onset of ESF. In this letter, it is shown that this is not necessarily the case and that meridional winds can be destabilizing. We find that a wind profile with a positive gradient as a function of latitude (∂V m ∕ ∂θ ≥ 0) is a stabilizing influence on the generalized Rayleigh‐Taylor instability; a wind profile with a negative gradient (∂V m ∕ ∂θ < 0) is a destabilizing influence. Here, a northward wind is positive, and θ increases in the northward direction. It is suggested that meridional wind profiles may account for, in part, the longitudinal and day‐to‐day variability of ESF.
A three‐hourly data set of the state of tropical convection based on cloud regimes
Authors: Tan Jackson , Jakob Christian
Published: March 2013

Tropical convection is a key driver in the climate system and is often identified using infrared satellite information or precipitation. Satellite‐derived cloud regimes offer an alternative with potentially more informative distinctions between different types of convection. However, current ISCCP cloud regime data sets require visible satellite information and are therefore only available during daytime. We develop a convective regime data set for all three‐hour intervals of the day using ISCCP infrared‐only retrievals. We show that regimes derived in this way capture the essential properties of the original regimes, in particular, when identifying the state of tropical convection. We give examples for potential applications by illustrating the well‐known Madden‐Julian Oscillation and the diurnal cycle of convection in the framework of the newly derived regimes. The high temporal resolution, long record and global coverage of the regimes makes them a suitable tool for large‐scale studies of tropical convection.
Single‐Base Resolution Sequence‐Directed Nucleosome Mapping
Authors: Trifonov Edward N. , Hapala Jan
Published: March 2013

Frequently used nucleosome mapping techniques, both experimental and computational ones, pursue a rather simple task – to determine whether a given sequence segment is likely to belong to a nucleosome, thus measuring the nucleosome occupancy along the sequence. A more ambitious task is to determine the position with high resolution, so that not only the approximate translational position of the nucleosome on DNA would be known, but also the rotational setting of the DNA. The rotational setting is important to know since the binding of various transcription factors to the nucleosome DNA crucially depends on the accessibility of the respective recognition sequences. The only experimental technique that provides the highest possible accuracy of the positioning is crystallization of the nucleosomes reconstituted on specific sequences, with subsequent solving of their structures from x‐ray diffraction data. Two computational approaches to the accurate positioning of nucleosomes, based on energy calculations and on sequence patterndirected mapping, are currently in different stages of progress.
Close Reading: A Cautionary Interpretation
Authors: Hinchman Kathleen A. , Moore David W.
Published: March 2013

Implementation of Common Core State Standards in English Language Arts across most of the United States has yielded the rapid creation of new, interconnected literacy assessments, curriculum guidelines, instructional materials, teacher preparation programs, teacher evaluation systems, and professional development. This essay explores two researchers' concerns about instructional recommendations for teaching students how to engage in close reading, a key construct underlying these Standards.

Meant to encourage and inform educators' exercise of professional judgment in planning instruction, the essay summarizes explicit and implied shifts in literacy instruction that are suggested by the new standards, examines various competing interpretations of close reading and close reading instruction, and offers research‐based instructional recommendations to enable youth to complete close reading tasks effectively, rather than distancing them further from the literacies needed to fulfill their lives.
Challenges and Opportunities for Language Learning in the Context of the CCSS and the NGSS
Authors: Hakuta Kenji , Santos María , Fang Zhihui
Published: March 2013

In this column, Kenji Hakuta and Mario Santos described the challenges and opportunities the Common Core State Standards and the Next Generation Science Standards present for language development in the context of English language arts/literacy, mathematics, and science. They heightened educators' awareness of the critical role language plays in literacy, learning, and assessment, suggesting that a focus on language is especially important for English Language Learners in their development of content area literacies.
In the Middle of Something: Reflections on Multimodal Inquiry as Artful Bricolage
Authors: Vasudevan Lalitha , Reilly Mary Ann
Published: March 2013

This article presents a conversation about the nature of multimodal inquiry and composing between Lalitha Vasudevan and Mary Ann Reilly. The authors draw on their Twitter exchanges, blog posts, art, photography, and reflections as they consider what literacy education is and can be in a world that offers multiple means of expression. The theoretical constructs of bricolage and rhizomatics inform how they think about their inquiry as well as how they present their ideas. The authors problematize literacy and arts education as it has been conceived and offer glimpses into what might be.
Set in Stone or Set in Motion?: Multimodal and Digital Writing With Preservice English Teachers
Authors: Hundley Melanie , Holbrook Teri
Published: March 2013

This study examines the literacy practices of pre‐service English teachers engaged in multimodal and digital composing in a writing methods course designed to support both print‐based and digital and/or multimodal composition practices. By examining the struggles and resistances of pre‐service English teachers as they adapted print‐based writing processes to multimodal or digital compositions, the researchers hope to identify strategies, practices, and approaches that will help pre‐service teachers develop new writing pedagogies.
Characteristics of the ocean simulations in the Max Planck Institute Ocean Model (MPIOM) the ocean component of the MPI‐Earth system model
Authors: Jungclaus J. H. , Fischer N. , Haak H. , Lohmann K. , Marotzke J. , Matei D. , Mikolajewicz U. , Notz D. , von Storch J. S.
Published: March 2013

MPI‐ESM is a new version of the global Earth system model developed at the Max Planck Institute for Meteorology. This paper describes the ocean state and circulation as well as basic aspects of variability in simulations contributing to the fifth phase of the Coupled Model Intercomparison Project (CMIP5). The performance of the ocean/sea‐ice model MPIOM, coupled to a new version of the atmosphere model ECHAM6 and modules for land surface and ocean biogeochemistry, is assessed for two model versions with different grid resolution in the ocean. The low‐resolution configuration has a nominal resolution of 1.5°, whereas the higher resolution version features a quasiuniform, eddy‐permitting global resolution of 0.4°. The paper focuses on important oceanic features, such as surface temperature and salinity, water mass distribution, large‐scale circulation, and heat and freshwater transports. In general, these integral quantities are simulated well in comparison with observational estimates, and improvements in comparison with the predecessor system are documented; for example, for tropical variability and sea ice representation. Introducing an eddy‐permitting grid configuration in the ocean leads to improvements, in particular, in the representation of interior water mass properties in the Atlantic and in the representation of important ocean currents, such as the Agulhas and Equatorial current systems. In general, however, there are more similarities than differences between the two grid configurations, and several shortcomings, known from earlier versions of the coupled model, prevail.
Photoacoustically‐guided photothermal killing of mosquitoes targeted by nanoparticles
Authors: Foster Stephen R. , Galanzha Ekaterina I. , Totten Daniel C. , Beneš Helen , Shmookler Reis Robert J. , Zharov Vladimir P.
Published: March 2013

In biomedical applications, nanoparticles have demonstrated the potential to eradicate abnormal cells in small localized pathological zones associated with cancer or infections. Here, we introduce a method for nanotechnology‐based photothermal (PT) killing of whole organisms considered harmful to humans or the environment. We demonstrate that laser‐induced thermal, and accompanying nano‐ and microbubble phenomena, can injure or kill C. elegans and mosquitoes fed carbon nanotubes, gold nanospheres, gold nanoshells, or magnetic nanoparticles at laser energies that are safe for humans. In addition, a photoacoustic (PA) effect was used to control nanoparticle delivery. Through the integration of this technique with molecular targeting, nanoparticle clustering, magnetic capturing and spectral sharpening of PA and PT plasmonic resonances, our laser‐based PA‐PT nano‐theranostic platform can be applied to detection and the physical destruction of small organisms and carriers of pathogens, such as malaria vectors, spiders, bed bugs, fleas, ants, locusts, grasshoppers, phytophagous mites, or other arthropod pests, irrespective of their resistance to conventional treatments. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Which density functional is close to CCSD accuracy to describe geometry and interaction energy of small noncovalent dimers? A benchmark study using Gaussian09
Authors: Remya Karunakaran , Suresh Cherumuttathu H.
Published: March 2013

A benchmark study on all possible density functional theory (DFT) methods in Gaussian09 is done to locate functionals that agree well with CCSD/aug‐cc‐pVTZ geometry and Ave‐CCSD(T)/(Q‐T) interaction energy (Eint) for small non‐covalently interacting molecular dimers in “dispersion‐dominated” (class 1), “dipole‐induced dipole” (class 2), and “dipole‐dipole” (class 3) classes. A DFT method is recommended acceptable if the geometry showed close agreement to CCSD result (RMSD < 0.045) and Eint was within 80–120% accuracy. Among 382 tested functionals, 1–46% gave good geometry, 13–44% gave good Eint, while 1–33% satisfied geometry and energy criteria. Further screening to locate the best performing functionals for all the three classes was made by counting the acceptable values of energy and geometry given by each functionals. The meta‐generalized gradient approximation (GGA) functional M06L was the best performer with total 14 hits; seven acceptable energies and seven acceptable geometries. This was the only functional “recommended” for at least two dimers in each class. The functionals M05, B2PLYPD, B971, mPW2PLYPD, PBEB95, and CAM‐B3LYP gave 11 hits while PBEhB95, PW91B95, Wb97x, BRxVP86, BRxP86, HSE2PBE, HSEh1PBE, PBE1PBE, PBEh1PBE, and PW91TPSS gave 10 hits. Among these, M05, B971, mPW2PLYPD, Wb97x, and PW91TPSS were among the “recommended” list of at least one dimer from each class. Long‐range correction (LC) of Hirao and coworkers to exchange‐correlation functionals showed massive improvement in geometry and Eint. The best performing LC‐functionals were LC‐G96KCIS and LC‐PKZBPKZB. Our results predict that M06L is the most trustworthy DFT method in Gaussian09 to study small non‐covalently interacting systems. © 2013 Wiley Periodicals, Inc.
Modeling of phytochrome absorption spectra
Authors: Falklöf Olle , Durbeej Bo
Published: March 2013

Phytochromes constitute one of the six well‐characterized families of photosensory proteins in Nature. From the viewpoint of computational modeling, however, phytochromes have been the subject of much fewer studies than most other families of photosensory proteins, which is likely a consequence of relevant high‐resolution structural data becoming available only in recent years. In this work, hybrid quantum mechanics/molecular mechanics (QM/MM) methods are used to calculate UV‐vis absorption spectra of Deinococcus radiodurans bacteriophytochrome. We investigate how the choice of QM/MM methodology affects the resulting spectra and demonstrate that QM/MM methods can reproduce the experimental absorption maxima of both the Q and Soret bands with an accuracy of about 0.15 eV. Furthermore, we assess how the protein environment influences the intrinsic absorption of the bilin chromophore, with particular focus on the Q band underlying the primary photochemistry of phytochromes. © 2013 Wiley Periodicals, Inc.
Engineering Saccharomyces cerevisiae for next generation ethanol production
Authors: den Haan Riaan , Kroukamp Heinrich , Mert Marlin , Bloom Marinda , Görgens Johann F. , van Zyl Willem H.
Published: March 2013

Conversion of cellulose, hemicellulose or starch to ethanol via a biological route requires enzymatic conversion of these substrates to monosaccharides that can be assimilated by a fermenting organism. Consolidation of these events in a single processing step via a cellulolytic or amylolytic microorganism(s) is a promising approach to low‐cost production of fuels and chemicals. One strategy for developing a microorganism capable of such consolidated bioprocessing (CBP) involves engineering Saccharomyces cerevisiae to expresses a heterologous enzyme system enabling (hemi)cellulose or starch utilization. The fundamental principle behind consolidated bioprocessing as a microbial phenomenon has been established through the successful expression of the major (hemi)cellulolytic and amylolytic activities in S. cerevisiae. Various strains of S. cerevisiae were subsequently enabled to grow on cellobiose, amorphous and crystalline cellulose, xylan and various forms of starch through the combined expression of these activities. Furthermore, host cell engineering and adaptive evolution have yielded strains with higher levels of secreted enzymes and greater resistance to fermentation inhibitors. These breakthroughs bring the application of CBP at commercial scale ever closer. This mini‐review discusses the current status of different aspects related to the engineering of S. cerevisiae for next generation ethanol production. © 2013 Society of Chemical Industry
MetFusion: integration of compound identification strategies
Authors: Gerlich Michael , Neumann Steffen
Published: March 2013

Mass spectrometry (MS) is an important analytical technique for the detection and identification of small compounds. The main bottleneck in the interpretation of metabolite profiling or screening experiments is the identification of unknown compounds from tandem mass spectra.

Spectral libraries for tandem MS, such as MassBank or NIST, contain reference spectra for many compounds, but their limited chemical coverage reduces the chance for a correct and reliable identification of unknown spectra outside the database domain.

On the other hand, compound databases like PubChem or ChemSpider have a much larger coverage of the chemical space, but they cannot be queried with spectral information directly. Recently, computational mass spectrometry methods and in silico fragmentation prediction allow users to search such databases of chemical structures.

We present a new strategy called MetFusion to combine identification results from several resources, in particular, from the in silico fragmenter MetFrag with the spectral library MassBank to improve compound identification. We evaluate the performance on a set of 1062 spectra and achieve an improved ranking of the correct compound from rank 28 using MetFrag alone, to rank 7 with MetFusion, even if the correct compound and similar compounds are absent from the spectral library. On the basis of the evaluation, we extrapolate the performance of MetFusion to the KEGG compound database. Copyright © 2013 John Wiley & Sons, Ltd.
ESI formation of a Meisenheimer complex from tetryl and its unusual dissociation
Authors: Hubert Cécile , Dossmann Héloïse , Machuron‐Mandard Xavier , Tabet Jean‐Claude
Published: March 2013

The reactivity of the explosive tetryl (N‐methyl‐N,2,4,6‐tetranitroaniline; Mw = 287 u) was studied using electrospray ionization in negative mode. The main species detected in the spectrum corresponds to the ion observed at m/z 318 (previously assumed to be the odd‐electron ion [tetryl + HNO]‐•, C7H6O9N6). In this study, we show using D‐labeling combined with high‐resolution mass spectrometry that this species corresponds to an even‐electron anion (i.e. C8H8O9N5), resulting from the formation of a Meisenheimer complex between tetryl and the methanol used as the solvent. Fragmentation of this complex under CID conditions revealed an unexpected fragment: the formation of a 2,4,6‐trinitrophenoxide anion at m/z 228. 18O‐labeling combined with quantum chemical calculations helped us better understand the reaction pathways and mechanisms involved in the formation of this product ion. This occurs via a transition state leading to a SN2‐type reaction, consequently evolving toward an ion‐dipole complex. The latter finally dissociates into deprotonated picric acid. Copyright © 2013 John Wiley & Sons, Ltd.
Genomic comparisons between paired bacterial strains with strong and weak GC skews
Authors: Song Tie‐Jun , Wang Yue , Shen Jian‐Gen , Pan Jian‐Ping , Huang Jun
Published: March 2013

A majority of known eubacterial genomes are characteristic of GC skew, i.e., the leading strand has exceeding number of G over C. The cause of this compositional bias is still not very clear. In this study, we chose five pairs of genomes from distantly related bacterial genera, i.e., Buchnera, Haemophilus, Mycoplasma, Mycobacterium, and Synechococcus, each containing one with strong GC skew and the other with weak GC skew. Through comparison of the orthologous genes in these genera, we found that neither chromosomal rearrangement nor CDS skew has direct relationship with GC skew.
Anti‐fibrosis effect of BMP‐7 peptide functionalization on cobalt chromium alloy
Authors: Tan Hark Chuan , Poh Chye Khoon , Cai Yanli , Wang Wilson
Published: March 2013

Orthopedic metallic prosthetic implants are commonly made of cobalt chromium (CoCr) alloys. However, such metal‐based implants are susceptible to fibrous capsule formation on the implant surface after implantation. At the bone‐implant interface, this capsule can prevent implant integration, resulting in loosening and failure. Minimizing the development of such a capsule on the CoCr surface would improve direct bone‐implant bonding leading to long‐term implant functionality. We evaluated the anti‐fibrosis effect of bone morphogenic protein‐7 (BMP‐7) peptide covalently bonded to CoCr alloy. This peptide, a biomimetic derivation of the knuckle epitope of BMP‐7, was conjugated at the N‐terminus with a cysteine amino acid. X‐ray photoelectron spectroscopy (XPS) and probe binding assay were used to evaluate different stages of grafting and surface functionalization using polydopamine coating. Cellular functions were studied using fibroblast attachment, cell proliferation, and MTT assays. Fibroblasts were grown on functionalized and pristine CoCr substrates, and the efficacy of BMP‐7 peptide on anti‐fibrosis was analyzed via gene expression and protein expression of fibrosis markers ACTA2, Collagen 1A1, and fibronectin. The peptide functionalized substrates showed significant reduction of fibrosis markers expression after 1 week of incubation compared to controls. BMP‐7 signaling pathway activation was shown by the presence of phosphorylation of Smad1/5/8. These findings may contribute to the improvement of CoCr implants in orthopedic surgery applications. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 983–990, 2013