bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep drainage estimates using multiple linear regression with percent clay content and rainfall
Authors: Wohling D. L. , Leaney F. W. , Crosbie R. S.
Published: February 2012

Abstract. Deep drainage estimates are required for effective management of water resources. However, field measurements are time consuming and costly so simple empirical relationships are often used. Relationships developed between clay content of the surface soil and deep drainage have been used extensively in Australia to provide regional estimates of deep drainage but these relationships have been poorly justified and did not include rainfall in the relationships. Here we present a rigorous appraisal of clay content of soils and rainfall as predictors of deep drainage using an extensive database of field observations from across Australia. This study found that annual average rainfall and the average clay content of the top 2 m of the soil are statistically significant predictors of point scale deep drainage. Relationships have been defined for annual, perennial and tree type vegetation as a line of best fit along with 95% confidence intervals. This allows the uncertainty in these deep drainage estimates to be assessed for the first time.
Development of a conceptual model of the hydrologic response of tropical Andean micro-catchments in Southern Ecuador
Authors: Crespo P. , Feyen J. , Buytaert W. , Célleri R. , Frede H.-G. , Ramírez M. , Breuer L.
Published: February 2012

Abstract. This paper presents a lumped conceptual model designed for simulating the rainfallrunoff response of mountain micro-catchments with natural vegetation located in the south of Ecuador. The conceptual model is mimicking the soil hydrology and consists of a maximum of three linear reservoirs in series. A two and three reservoir model structure were tested, respectively A GLUE uncertainty analysis was applied to assess the model performance. Simulation results of the discharge confirmed the applicability of the soil-based conceptual model structure for the selected study areas, during model calibration and validation. The three reservoir model best predicted the runoff, nevertheless the two reservoir model well captures the rainfall-runoff process of the micro-catchments with páramo vegetation. Although differences in climate regime, vegetation, and soil of the selected catchments runoff is strongly controlled by the precipitation and soil type, and the horizons contributing to runoff are defined by their antecedent wetness. Results confirm that the discharge is mainly controlled by lateral subsurface flow through the organic horizons, while during dry conditions the C-horizon and the bedrock mainly contribute to discharge. Lateral transport through the densely rooted top horizon and the litter layer occurs during storm events, being under those conditions the major discharge component. Overland flow is a local phenomenon, negligible in comparison to the other flow components.
Assessment of shallow subsurface characterization with non-invasive geophysical methods at the intermediate hill-slope scale
Authors: Popp S. , Altdorff D. , Dietrich P.
Published: February 2012

Abstract. Hill-slopes of several hectares in size represent a difficult scale for subsurface characterization, as these landscape units are well beyond the scope of traditional point-scale techniques. By means of electromagnetic induction (EMI) and gamma-ray spectroscopy, spatially distributed soil proxy data were collected from a heterogeneous hill-slope site. Results of repeated EMI mapping using the EM38DD showed that soil electrical conductivity (ECa) is highly variable at both temporal and spatial scales. Calibration of the integral ECa signal to soil moisture is hampered by the ambiguous response of EMI to the clay-rich hill-slope underground. Given a stationarity signal of geologic background, temporal changes of ECa are attributable to relative soil-moisture dynamic. Gamma-ray results were obtained during a single survey, along with EM measurements and selected soil sampling. In contrast to ECa, a noticeable correlation between Total Count and K emission data and soil-water content seemed to be present. Relevant proxy variables from both methods were used for k-means clustering in order to distinguish between hill-slope areas with different soil conditions. As a result, we obtained a suitable partition of hill-slope that was comparable with a previously obtained zonation model based on ecological factors.
ULTRASONIC AIDED EXTRUSION OF CNT- AND CNF-FILLED SBR COMPOUNDS AND PROPERTIES OF THEIR VULCANIZATES
Authors: Choi Jaesun , Isayev Avraam I.
Published: February 2012

Ultrasonically assisted single screw extrusion of styrene–butadiene rubber (SBR) compounds filled with multiwall carbon nanotubes (CNT) up to 20 phr and carbon nanofibers (CNF) up to 35 phr was carried out. The effects of ultrasonic amplitude on processing characteristics, rheology, extractable amount, vulcanization behavior, mechanical properties, abrasion, electrical resistivity, and morphology were investigated. Ultrasonically treated compounds showed an increase in viscosity and unextractable content in both CNT- and CNF-filled compounds. A decrease in the induction time of curing with amplitude was observed in CNT-filled compounds. However, the induction time of CNF-filled compounds showed more complex behavior with amplitude. The final cure torque, crosslink density, modulus, and tensile strength showed a maximum at an intermediate amplitude in filled vulcanizates. An increase in the glass transition temperature (Tg) and a decrease in tan δ at Tg with amplitude were observed in CNF- and CNT-filled vulcanizates. At the same time, tan δ in the range of 0–60 °C of these vulcanizates showed, respectively, a minimum and a continuous increase with amplitude. CNF-filled vulcanizates exhibited improved abrasion resistance with optimum results at an amplitude of 5.0 μm. The effect diminished with increasing CNF loadings. Improvements in abrasion resistance of CNT-filled vulcanizates were observed at certain amplitudes at low CNT loadings only. Ultrasonic treatment caused a significant reduction in the electrical percolation threshold of CNF- and CNT-filled vulcanizates. Atomic force microscope analysis showed a generation of unique CNT agglomerates by ultrasonic treatment, suggesting an increase of rubber–filler interaction. High resolution scanning electron microscopy analysis of vulcanizates showed better dispersion of ZnO by ultrasonic treatment.
ZINC OXIDE VERSUS MAGNESIUM OXIDE REVISITED. PART 2
Authors: Guzmán Manuel , Vega Berta , Agulló Núria , Borrós Salvador
Published: February 2012

Zinc oxide is a widely used compound in the rubber industry due to the excellent properties that it shows as an activator and, consequently, its role in the mechanism of accelerated sulfur vulcanization has been extensively studied. Due to the increased concern about its environmental effects, several research studies have been carried out in order to substitute it with different metal oxides such us MgO. The effect of the activator system in order to minimize the environmental impact of the rubber goods has been explored. The work developed is presented in two parts. In Part 1, the influence of different mixtures of ZnO and MgO in the vulcanization of natural rubber has been investigated. In Part 2 of the study, model compound vulcanization has been used to study the role of MgO on the mechanism to gain a better understanding of the differences shown in the first part.
FUNCTIONALIZATION OF USED TIRE RUBBER BY HYDROSILYLATION
Authors: Banda Madan , Naskar Amit K. , Perera K. Prasanna U. , Moreland Cal , Hodge Tom , Wallace Kevin , Beckham Haskell W. , Smith Dennis W.
Published: February 2012

A new method for the surface modification of used tire rubber (UTR) is being developed. The method involves hydrosilylation of ground UTR particles with trichlorosilane (TCS) under various reaction conditions. The reaction has been carried out with and without solvents and catalysts (Karsted's/Pt catalyst). TCS treated UTR particles are then hydrolyzed to obtain silanol functionalized hydrosilylated rubber powder. Attenuated total reflection–Fourier transform infrared, solid-state 13C NMR spectroscopy, and thermogravimetric analysis are provided as evidence of hydrosilylation onto rubber particles.
MULTIAXIAL FATIGUE CRITERIA APPLIED TO A POLYCHLOROPRENE RUBBER
Authors: Poisson J. L. , Méo S. , Lacroix F. , Berton G. , Ranganathan N.
Published: February 2012

Due to their interesting mechanical behavior and their diversity, rubber materials are more and more used in industry. Indeed, formulating a multiaxial fatigue criterion to predict fatigue lives of rubber components constitutes an important objective to conceive rubber products. An experimental campaign is developed here to study the multiaxial fatigue behavior of polychloroprene rubber. To reproduce multiaxial solicitations, combined tension–torsion tests were carried out on a dumbbell-type specimen (an axisymmetric rubber part bonded to metal parts with a reduced section at mid-height), with several values of phase angles between tension and torsion. A constitutive model is needed to calculate multiaxial fatigue criteria, and then analyze fatigue results. A large strain viscoelastic model, based on the tension–torsion kinematics, is then used to determine the material's stress–strain law. Dissipated energy density is introduced as a multiaxial fatigue criterion, and compared with those usually used in the literature. A multiaxial Haigh diagram is then built to observe the influence of Rd-ratio (ratio of the axial displacement's minimum to the axial displacement's maximum) on the multiaxial fatigue lives of polychloroprene rubber.
EFFECT OF ZINC DITHIOCARBAMATES AND THIAZOLE-BASED ACCELERATORS ON THE VULCANIZATION OF NATURAL RUBBER
Authors: Alam Md. Najib , Mandal Swapan Kumar , Debnath Subhas Chandra
Published: February 2012

Several zinc dithiocarbamates (ZDCs) as accelerator derived from safe amine has been exclusively studied in the presence of thiazole-based accelerators to introduce safe dithiocarbamate in the vulcanization of natural rubber. Comparison has been made between conventional unsafe zinc dimethyldithiocarbamate (ZDMC) with safe novel ZDC combined with thizole-based accelerators in the light of mechanical properties. The study reveals that thiuram disulfide and 2-mercaptobenzothiazole (MBT) are always formed from the reaction either between ZDC and dibenzothiazyledisulfide (MBTS) or between ZDC and N-cyclohexyl-2-benzothiazole sulfenamide (CBS). It has been conclusively proved that MBT generated from MBTS or CBS reacts with ZDC and produces tetramethylthiuram disulfide. The observed synergistic activity has been discussed based on the cure and physical data and explained through the results based on high-performance liquid chromatography and a reaction mechanism. Synergistic activity is observed in all binary systems studied. The highest tensile strength is observed in the zinc (N-benzyl piperazino) dithiocarbamate-accelerated system at 3:6 mM ratios. In respect of tensile strength and modulus value, unsafe ZDMC can be successfully replaced by safe ZDCs in combination with thiazole group containing accelerator.
Synthesis of 2‐Aryl Pyridines by Palladium‐Catalyzed Direct Arylation of Pyridine
N
‐Oxides
Authors: Campeau Louis‐Charles , Fagnou Keith
Published: February 2012

Palladium acetate

P

t

Bu
3
‐
HBF
4

Pyridine
N
‐oxide

4‐Bromotoluene

Potassium carbonate

Zinc

2‐(4’‐Methylphenyl)‐pyridine
Synthesis of Lithium 2‐Pyridyltriolborate and its Cross‐Coupling Reaction with Aryl Halides
Authors: Yamamoto Yasunori , Sugai Juugaku , Takizawa Miho , Miyaura Norio
Published: February 2012

2‐Bromopyridine

Triisopropyl borate

n‐Butyllithium

1,1,1‐Tris(hydroxymethyl)ethane

Lithium 2‐pyridiltriolborate

Methyl 4‐bromobenzoate

Methyl 4‐(2‐pyridyl)benzoate

Dichloro[1,3‐bis(diphenylphosphino)propane]palladium

Triphenylphosphine
Preparation of Isopropyl 2‐Diazoacetyl(Phenyl)Carbamate
Authors: Muchalski Huikai , Doody Amanda B , Troyer Timothy L , Johnston Jeffrey N
Published: February 2012

Isopropyl chloroformate

Aniline

Triethylamine

n‐
Butyllithium

Acetic anhydride

1,1,1,3,3,3‐Hexamethyldisilazane

Isopropyl acetyl(phenyl)carbamate

2,2,2‐Trifluoroethyl trifluoroacetate

4‐Acetamidobenzenesulfonyl azide

Carbamic acid

N
‐(2‐diazoacetyl)‐
N
‐phenyl‐

1‐methylethyl ester
Lithiated Primary Alkyl Carbamates for the Homologation of Boronic Esters
Authors: Webster Matthew P. , Partridge Benjamin M. , Aggarwal Varinder K.
Published: February 2012

N,N
‐Diisopropyl‐carbamic acid 3‐phenyl‐propyl ester

Isobutylboronic acid pinacol ester (
R
)‐5‐Methyl‐1‐phenylhexan‐3‐ol 3‐Phenylpropan‐1‐ol
N,N
‐Diisopropylcarbamoyl chloride

Triethylamine

Isobutylboronic acid

Pinacol
sec‐
Butyllithium (—)‐Sparteine
Enantioselective Three‐Component Reaction for the Preparation of β‐Amino‐α‐Hydroxy Esters
Authors: Zhou Jing , Xu Xinfang , Hu. Wenhao
Published: February 2012

Benzaldehyde
p
‐Anisidine

Benzaldehyde‐
p
‐anisidine imine 9‐Anthracenemethanol 9‐Anthraldehyde
R
‐(+)‐1,1’‐Bi‐2‐naphthol, (
R
)‐BINOL (
R
)‐2,2’‐(9‐Phenanthryl)‐BINOL phosphoric acid

Dirhodium tetraacetate dehydrate

Methyl (4‐methoxyphenyl)diazoacetate

4‐Methoxyphenylacetic acid (2
S
, 3
S
)‐Methyl‐2‐(9‐anthryloxy‐methyl)‐2‐(4‐methoxyphenyl)‐3‐(4‐methoxy‐phenylamino)‐3‐phenylpropanoate
A robust adaptive control architecture for disturbance rejection and uncertainty suppression with L ∞  transient and steady‐state performance guarantees
Authors: Yucelen Tansel , Haddad Wassim M.
Published: February 2012

In this paper, a new adaptive control architecture for linear and nonlinear uncertain dynamical systems is developed to address the problem of high‐gain adaptive control. Specifically, the proposed framework involves a new and novel controller architecture involving a modification term in the update law that minimizes an error criterion involving the distance between the weighted regressor vector and the weighted system error states. This modification term allows for fast adaptation without hindering system robustness. In particular, we show that the governing tracking closed‐loop system error equation approximates a Hurwitz linear time‐invariant dynamical system with input–output signals. This key feature of our framework allows for robust stability analysis of the proposed adaptive control law using system theory. We further show that by properly choosing the design parameters in the modification term, we can guarantee a desired bandwidth of the adaptive controller, guaranteed transient closed‐loop performance, and an a priori characterization of the size of the ultimate bound of the closed‐loop system trajectories. Several illustrative numerical examples are provided to demonstrate the efficacy of the proposed approach. Copyright © 2012 John Wiley & Sons, Ltd.
Achieving High Mid‐IR Bolometric Responsivity for Anisotropic Composite Materials from Carbon Nanotubes and Polymers
Authors: Glamazda Alexander Y. , Karachevtsev Victor. A. , Euler William B. , Levitsky Igor A.
Published: February 2012

An anisotropic carbon nanotube (CNT)‐polymer composite for bolometric applications in the mid‐IR spectral range (2.5–20 μm) is studied. Composite alignment in conjunction with non‐uniform distribution of CNTs in the polymer matrix allows for a significant enhancement of the temperature coefficient of resistance (0.82% K−1) with respect to uniform composite (0.24% K−1). As a result a responsivity of ≈ 500 V W−1 is reached, which is the highest for CNT‐based bolometers reported to date. Such remarkable optical and thermal characteristics are explained in terms of fluctuation tunneling theory taking into account the composite anisotropy and the gradient of the CNT concentration. Flatness of the photoresponse in the broad spectral mid‐IR range and enhanced responsivity provide a great potential for the use of such novel composite for applications in IR spectroscopy and thermal imaging.
Hydrodynamic modeling on the external liquid–solid wetting efficiency in a trickling flow reactor
Authors: Cheng Zhen‐Min , Kong Xiang‐Ming , Zhu Jun , Wang Zhen‐Yuan , Jin Jian , Huang Zi‐Bin
Published: February 2012

A three‐region model was proposed, which considers the bed cross section being composed of a stagnant liquid region, a liquid film region, and a rivulet flow region. To estimate the fractions of the three regions, the fraction of film flow was evaluated first, by transforming the complex trickling flow texture into pure liquid film flow. Through the measurements of liquid holdup and pressure drop for the film flow, a relationship between relative permeability and gas saturation was established, and from which the fraction of film flow region was obtained. It shows packing size is most important to the faction of rivulet flow. The external wetting efficiency of the packing was correlated as the sum of two‐third power of the liquid film fraction and the rivulet flow fraction, besides, a correlation based on Reynolds and Galileo numbers of the two phases in the form of was proposed. © 2012 American Institute of Chemical Engineers AIChE J, 59: 283–294, 2013
Persistency with zoledronic acid is associated with clinical benefit in patients with multiple myeloma
Authors: Henk Henry J. , Teitelbaum April , Perez Jose Ricardo , Kaura Satyin
Published: February 2012

Zoledronic acid (ZOL), an intravenous bisphosphonate, has been shown to reduce and delay the incidence of skeletal‐related events (SREs) in multiple myeloma (MM) patients with bone disease. A retrospective claims‐based analysis was conducted that used two distinct US managed care databases to examine the relationship between persistency with ZOL and clinical benefit. Patients >18 years, diagnosed with MM, and with at least one claim for ZOL (or a claim for malignant bone disease and ZOL initiation within 30 days) between 1/1/2001 and 12/31/2006 were included. Patients were evaluated for incidence of SREs and for mortality. Treatment persistency was defined as the absence of a >45 day gap between ZOL administrations. Of 1,655 patients in this analysis, 1,060 received ZOL and 595 received no intravenous bisphosphonate therapy. Compared with patients not receiving bisphosphonate therapy, ZOL‐treated patients had lower incidences of SREs (P < 0.0001) and death (P = 0.0001). Longer persistency with ZOL was associated with lower risks of SREs (P = 0.001), fracture (P = 0.003), and death (P = 0.002) versus shorter persistency. Patients who were persistent with ZOL for ≥1.5 years had an incidence of 15.0 SREs and 6.2 fractures per 100 person‐years. Patients who were persistent for 31–90 days had an incidence of 24.6 SREs and 14.0 fractures per 100 person‐years, and patients not receiving intravenous bisphosphonates had an incidence of 32.2 SREs and 16.9 fractures per 100 person‐years. These data from a real‐world setting indicate that among MM patients, longer persistency with ZOL was associated with a lower risk of SREs and fracture. Am. J. Hematol. 87:490–495, 2012. © 2012 Wiley Periodicals, Inc.
Dissociation of periodic leg movements from arousals in restless legs syndrome
Authors: Manconi Mauro , Ferri Raffaele , Zucconi Marco , Bassetti Claudio L. , Fulda Stephany , Aricò Debora , Ferini‐Strambi Luigi
Published: February 2012

Objective:

The purpose of this study was to characterize the nature of the relation between periodic leg movements during sleep (PLMS) and cortical arousals to contribute to the debate on the clinical significance and treatment of PLMS.

Methods:

A prospective, placebo‐controlled, single‐blind, parallel group study was carried out including 46 drug‐naive patients with idiopathic restless legs syndrome (RLS). Each patient underwent 2 consecutive full‐night polysomnographic studies. The first night was the baseline night. Prior to the second night, 1 group received a single oral dose of 0.25mg pramipexole, whereas a second group received a single oral dose of 0.5mg clonazepam, and the remaining patients received placebo. Sleep stages, cyclic alternating pattern (CAP), and leg movement activity were scored following standard criteria; symptoms of RLS were also assessed.

Results:

Pramipexole suppressed PLMS without affecting electroencephalographic (EEG) instability (CAP) and arousals (corresponding to CAP A3 and, partially, A2 subtypes), whereas clonazepam did the opposite, reducing non‐rapid eye movement sleep EEG instability without effects on PLMS. Both drugs were effective on sensory RLS symptoms.

Interpretation:

This study demonstrates that a selective pharmacological approach can disconnect PLMS from arousal events, suggesting an indirect relation between each other. These results might weaken the hypothesis of a direct pathological role of PLMS in sleep disruption and can be important for the discussion on the existence of a distinct entity called periodic limb movements disorder. Moreover, the study opens the doors to the possibility of a joint treatment for RLS targeting sensory and motor symptoms, as well as sleep instability. ANN NEUROL 2012;71:834–844
Functional magnetic resonance imaging detection of vascular reactivity in cerebral amyloid angiopathy
Authors: Dumas Andrew , Dierksen Gregory A. , Gurol M. Edip , Halpin Amy , Martinez‐Ramirez Sergi , Schwab Kristin , Rosand Jonathan , Viswanathan Anand , Salat David H. , Polimeni Jonathan R. , Greenberg Steven M.
Published: February 2012

Objective:

In addition to its role in hemorrhagic stroke, advanced cerebral amyloid angiopathy (CAA) is also associated with ischemic lesions and vascular cognitive impairment. We used functional magnetic resonance imaging (MRI) techniques to identify CAA‐associated vascular dysfunction.

Methods:

Functional MRI was performed on 25 nondemented subjects with probable CAA (mean ± standard deviation age, 70.2 ± 7.8 years) and 12 healthy elderly controls (age, 75.3 ± 6.2 years). Parameters measured were reactivity to visual stimulation (quantified as blood oxygen level‐dependent [BOLD] response amplitude, time to peak response, and time to return to baseline after stimulus cessation) and resting absolute cerebral blood flow in the visually activated region (measured by arterial spin labeling).

Results:

CAA subjects demonstrated reduced response amplitude (percentage change in BOLD signal, 0.65 ± 0.28 vs 0.89 ± 0.14; p < 0.01), prolonged time to peak (11.1 ± 5.1 vs 6.4 ± 1.8 seconds; p < 0.001), and prolonged time to baseline (16.5 ± 6.7 vs 11.6 ± 3.1 seconds; p < 0.001) relative to controls. These differences were independent of age, sex, and hypertension in multivariable analysis and were also present in secondary analyses excluding nonresponsive voxels or voxels containing chronic blood products. Within the CAA group, longer time to peak correlated with overall volume of white matter T2 hyperintensity (Pearson correlation, 0.53; p = 0.007). Absolute resting blood flow in visual cortex, in contrast, was essentially identical between the groups (44.0 ± 12.6 vs 45.0 ± 10.0ml/100g/min, p = 0.8).

Interpretation:

Functional MRI identifies robust differences in both amplitude and timing of the response to visual stimulation in advanced CAA. These findings point to potentially powerful approaches for identifying the mechanistic links between vascular amyloid deposits, vascular dysfunction, and CAA‐related brain injury. ANN NEUROL 2012;72:76–81
Somatic mitochondrial DNA mutations in early parkinson and incidental lewy body disease
Authors: Lin Michael T. , Cantuti‐Castelvetri Ippolita , Zheng Kangni , Jackson Katie E. , Tan Yong B. , Arzberger Thomas , Lees Andrew J. , Betensky Rebecca A. , Beal M. Flint , Simon David K.
Published: February 2012

Somatic mutations in mitochondrial DNA (mtDNA) are hypothesized to play a role in Parkinson disease (PD), but large increases in mtDNA mutations have not previously been found in PD, potentially because neurons with high mutation levels degenerate and thus are absent in late stage tissue. To address this issue, we studied early stage PD cases and cases of incidental Lewy body disease (ILBD), which is thought to represent presymptomatic PD. We show for the first time that mtDNA mutation levels in substantia nigra neurons are significantly elevated in this group of early PD and ILBD cases. Ann Neurol 2012;71:850–854
Calcium‐permeable AMPA receptors are expressed in a rodent model of status epilepticus
Authors: Rajasekaran Karthik , Todorovic Marko , Kapur Jaideep
Published: February 2012

Objective:

A study was undertaken to characterize the plasticity of AMPA receptor (AMPAR)‐mediated neurotransmission in the hippocampus during status epilepticus (SE).

Methods:

SE was induced by pilocarpine, and animals were studied 10 minutes (refractory SE) or 60 minutes (late SE) after the onset of the first grade 5 seizures. AMPAR‐mediated currents were recorded from CA1 pyramidal neurons and dentate granule cells (DGCs) by voltage clamp technique. The surface expression of GluA2 subunit on hippocampal membranes was determined using a biotinylation assay. GluA2 internalization and changes in intracellular calcium ([Ca]i) levels were studied in hippocampal cultures using immunocytochemical and live‐imaging techniques. AMPAR antagonist treatment of SE was evaluated by video and electroencephalography.

Results:

AMPAR‐mediated currents recorded from CA1 neurons from refractory and late SE animals were inwardly rectifying, and philanthotoxin‐sensitive; similar changes were observed in recordings obtained from DGCs from refractory SE animals. GluA2 subunit surface expression was reduced in the hippocampus during refractory and late SE. In cultured hippocampal pyramidal neurons, recurrent bursting diminished surface expression of the GluA2 subunit and enhanced its internalization rate. Recurrent bursting‐induced increase in [Ca]i levels was reduced by selective inhibition of GluA2‐lacking AMPARs. GYKI‐52466 terminated diazepam‐refractory SE.

Interpretation:

During SE, there is rapid, ongoing plasticity of AMPARs with the expression of GluA2‐lacking AMPARs. These receptors provide another source of Ca2+ entry into the principal neurons. Benzodiazepam‐refractory SE can be terminated by AMPAR antagonism. The data identify AMPARs as a potential therapeutic target for the treatment of SE. ANN NEUROL 2012;72:91–102
Morphological diversity and phenotypic plasticity in the threatened British white‐clawed crayfish (Austropotamobius pallipes)
Authors: Haddaway Neal R. , Mortimer Robert J. G. , Christmas Martin , Grahame John W. , Dunn Alison M.
Published: February 2012

Relocation of threatened populations is a common method employed in conservation. However, environmental differences in the new habitat may reduce the survival of relocated populations, while phenotypic plasticity may enhance the likelihood of establishment of relocated populations in their novel environment.

Conservation of the British white‐clawed crayfish (Austropotamobius pallipes; IUCN Red Data List – Endangered) often involves relocation of threatened populations into isolated ponds (Ark Sites), where risk of competition with invasive crayfish is minimized.

In this study, the morphology (using 12 morphometric variables) of A. pallipes in wild populations was investigated with respect to eco‐geographic variables. A field cage experiment was carried out to compare the relative survival, growth, and change in morphology of crayfish from lotic (stream) and lentic (pond) donor habitats following relocation to a lentic recipient habitat.

In the wild, lentic crayfish were broader than their lotic counterparts, which may reflect an increase in branchial (gill) volume in adaptation to an oxygen‐poor benthic environment.

In the relocation experiment there was no difference in the length, growth, or survival of animals from relocated lentic, lotic, or control populations. However, crayfish derived from a lotic population showed an increase in carapace width and areola width over the 4‐month growing season following relocation.

This evidence for phenotypic plasticity suggests that crayfish are resilient to relocation, and that they can adapt morphologically to novel environmental conditions. Relocation of threatened populations of A. pallipes may therefore prove a useful technique in the conservation of white‐clawed crayfish populations within the UK. Copyright © 2012 John Wiley & Sons, Ltd.
Spectrofluorimetric determination of oseltamivir phosphate through derivatization with o‐phthalaldehyde. Application to pharmaceutical preparations with a preliminary study on spiked plasma samples
Authors: Walash M. I. , Belal F. , El‐Enany N. , El‐Maghrabey M. H.
Published: February 2012

A simple and sensitive spectrofluorimetric method has been developed and validated for the determination of oseltamivir phosphate (OST) in pharmaceutical preparations. The method is based on the reaction between oseltamivir phosphate and o‐phthalaldehyde in presence of 2‐mercapto‐ethanol in borate buffer, pH 10.8, to give a highly fluorescent product measured at 450 nm after excitation at 336 nm. The different experimental parameters affecting the development and stability of the reaction product were studied and optimized. The fluorescence intensity–concentration plot is rectilinear over the range 0.05–1.0 µg/mL, with a lower detection limit of 5 ng/mL and limit of quantitation of 16 ng/mL. The developed method was successfully applied to the analysis of the drug in its commercial capsules and suspension, mean recoveries of OST were 99.97 ± 1.67% and 100.17 ± 1.18%, respectively (n = 3). Statistical comparison of the results obtained by the proposed and comparison method revealed no significant difference in the performance of the two methods regarding accuracy and precision. The proposed method was further extended to in vitro determination of the studied drug in spiked human plasma as a preliminary investigation; the mean recovery (n = 3) was 98.68 ± 5.8%. A reaction pathway was postulated. Copyright © 2012 John Wiley & Sons, Ltd.
Enzymatic activity of albumin shown by coelenterazine chemiluminescence
Authors: Vassel N , Cox CD , Naseem R , Morse V , Evans RT , Power RL , Brancale A , Wann KT , Campbell AK
Published: February 2012

Bioluminescence, the emission of light from live organisms, occurs in 18 phyla and is the major communication system in the deep sea. It has appeared independently many times during evolution but its origins remain unknown. Coelenterazine bioluminescence discovered in luminous jellyfish is the most common chemistry causing bioluminescence in the sea, occurring in seven phyla. Sequence similarities between coelenterazine luciferases and photoproteins from different phyla are poor (often < 5%). The aim of this study was to examine albumin that binds organic substances as a coelenterazine luciferase to test the hypothesis that the evolutionary origin of a bioluminescent protein was the result of the formation of a solvent cage containing just a few key amino acids. The results show for the first time that bovine and human albumin catalysed coelenterazine chemiluminescence consistent with a mono‐oxygenase, whereas gelatin and haemoglobin, an oxygen carrier, had very weak activity. Insulin also catalysed coelenterazine chemiluminescence and was increased by Zn2+. Albumin chemiluminescence was heat denaturable, exhibited saturable substrate characteristics and was inhibited by cations that bound these proteins and by drugs that bind to human albumin drug site I. Molecular modelling confirmed the coelenterazine binding site and identified four basic amino acids: lys195, arg222, his242 and arg257, potentially important in binding and catalysis similar to naturally occurring coelenterazine bioluminescent proteins. These results support the ‘solvent cage’ hypothesis for the evolutionary origin of enzymatic coelenterazine bioluminescent proteins. They also have important consequences in diseases such as diabetes, gut disorders and food intolerance where a mono‐oxygenase could affect cell surface proteins. Copyright © 2012 John Wiley & Sons, Ltd.
Ten-year follow-up of skin-sparing mastectomy followed by immediate breast reconstruction
Authors: Romics L , Chew B K , Weiler-Mithoff E , Doughty J C , Brown I M , Stallard S , Wilson C R , Mallon E A , George W D
Published: February 2012

Background

The oncological safety of skin-sparing mastectomy (SSM) followed by immediate breast reconstruction (IBR) is debated owing to a presumed compromise in the completeness of mastectomy. Current evidence is poor as it is based mostly on short-term follow-up data from highly selected patients.

Methods

A prospectively maintained institutional database was searched to identify patients who underwent SSM and IBR between 1995 and 2000. A retrospective review of medical records was carried out, including only patients with ductal carcinoma in situ and invasive breast cancer. During this time all patients treated with mastectomy were offered IBR regardless of tumour stage.

Results

Follow-up data from 253 consecutive patients with IBR were reviewed. Patients with incomplete follow-up data and those undergoing SSM for recurrent disease following previous lumpectomy were disregarded, leaving 207 for analysis. Offering IBR to all women requiring mastectomy resulted in a large proportion of patients with advanced disease. During a median follow-up of 119 months, 17 (8·2 per cent) locoregional, six (2·9 per cent) local and 22 (10·6 per cent) distant recurrences were detected; the overall recurrence rate was 39 (18·8 per cent). Overall recurrence rate was associated with axillary lymph node metastasis (P = 0·009), higher stage (P < 0·001) and higher tumour grade (P = 0·031). The breast cancer-specific survival rate was 90·8 per cent (19 of 207 women died from recurrence).

Conclusion

Based on these long-term follow-up data, SSM combined with IBR is an oncologically safe treatment option regardless of tumour stage.
Identification of a Novel Protein Synthesis Inhibitor Active against Gram‐Positive Bacteria
Authors: Eibergen Nora R. , Im Isak , Patel Nisha Y. , Hergenrother Paul J.
Published: February 2012

In an effort to identify novel antibacterial chemotypes, we performed a whole‐cell screen for inhibitors ofStaphylococcus aureusgrowth and pursued those compounds with previously uncharacterized antibacterial activity. This process resulted in the identification of a benzothiazolium salt, ABTZ‐1, that displayed potent antibacterial activity against Gram‐positive pathogens. Several clinically desirable qualities were demonstrated for ABTZ‐1 including potent activity against multidrug‐resistant clinical isolates of methicillin‐resistantS. aureus(MRSA) and vancomycin‐resistant enterococci (VRE), retention of this activity in human serum, and low hemolytic activity. The antibacterial activity of ABTZ‐1 was attributed to its inhibition of bacterial translation, as this compound prevented the incorporation of [35S]methionine intoS. aureusproteins, and ABTZ‐1‐resistant strains were cross‐resistant to known inhibitors of bacterial translation. ABTZ‐1 represents a promising new class of antibacterial agents.
Stabilization of G‐Quadruplex DNA, Inhibition of Telomerase Activity and Live Cell Imaging Studies of Chiral Ruthenium(II) Complexes
Authors: Sun Dongdong , Liu Yanan , Liu Du , Zhang Rong , Yang Xicheng , Liu Jie
Published: February 2012

Telomerase inhibition is an attractive strategy for cancer chemotherapy. In the current study, we have synthesized and characterized two chiral ruthenium(II) complexes, namely, Λ‐[Ru(phen)2(p‐MOPIP)]2+ and Δ‐[Ru(phen)2(p‐MOPIP)]2+, where phen is 1,10‐phenanthroline and p‐MOPIP is 2‐(4‐methoxyphenyl)‐imidazo[4,5f][1,10]phenanthroline. The chiral selectivity of the compounds and their ability to discriminate quadruplex DNA were investigated by using UV/Vis, fluorescence spectroscopy, circular dichroism spectroscopy, fluorescence resonance energy transfer melting assay, polymerase chain reaction stop assay and telomerase repeat amplification protocol. The results indicate that the two chiral compounds could induce and stabilize the formation of antiparallel G‐quadruplexes of telomeric DNA in the presence or absence of metal cations. We report the remarkable ability of the two complexes Λ‐[Ru(phen)2(p‐MOPIP)]2+ and Δ‐[Ru(phen)2(p‐MOPIP)]2+ to stabilize selectively G‐quadruplex DNA; the former is a better G‐quadruplex binder than the latter. The anticancer activities of these complexes were evaluated by using the MTT assay. Interestingly, the antiproliferative activity of Λ‐[Ru(phen)2(p‐MOPIP)]2+ was higher than that of Δ‐[Ru(phen)2(p‐MOPIP)]2+, and Λ‐[Ru(phen)2(p‐MOPIP)]2+ showed a significant antitumor activity in HepG2 cells. The status of the nuclei in Λ/Δ‐[Ru(phen)2(p‐MOPIP)]2+‐treated HepG2 cells was investigated by using real‐time living cell microscopy to determine the effects of Λ/Δ‐[Ru(phen)2(p‐MOPIP)]2+ on intracellular accumulation. The results show that Λ/Δ‐[Ru(phen)2(p‐MOPIP)]2+ can be taken up by HepG2 cells and can enter into the cytoplasm as well as accumulate in the nuclei; this suggests that the nuclei were the cellular targets of Λ/Δ‐[Ru(phen)2(p‐MOPIP)]2+.
Nitrogen‐Rich 5,5′‐Bistetrazolates and their Potential Use in Propellant Systems: A Comprehensive Study
Authors: Fischer Niko , Izsák Dániel , Klapötke Thomas M. , Rappenglück Sebastian , Stierstorfer Jörg
Published: February 2012

A large variety of twice‐deprotonated nitrogen‐rich 5,5′‐bistetrazolates, that is, the ammonium (1), hydrazinium (2), hydroxylammonium (3), guanidinium (4), aminoguanidinium (5), diaminoguanidinium (6), triaminoguanidinium (7), and diaminouronium (8) salts, have been synthesized. Energetic compounds 1–8 were fully characterized by single‐crystal X‐ray diffraction (except 8), NMR spectroscopy, IR and Raman spectroscopy, and differential scanning calorimetry (DSC) measurements. With respect to their potential use in propellant applications, the sensitivity towards impact, friction, and electrical discharge were determined. Several propulsion and detonation parameters (e.g., heat of explosion, detonation velocity) were computed by using the EXPLO5 computer code based on calculated (CBS‐4M) heats of formation and X‐ray densities. Additionally, the performance of 1–8 in various formulations was investigated by calculating the specific energy and specific impulse of the compounds under isochoric conditions.
Cancer screening of the uterine cervix papanicolaou smears versus state‐of‐the‐art human papillomavirus testing
Authors: Knight Bryan
Published: February 2012

The article by Albrow et al in this issue describes the early cervical screening program in England as being “disorganized,” but goes on to describe significant improvements over 20 years. It has become one of the leading screening programs in the developed world. Liquid‐based technology has been embraced, but image analysis has not. The key ingredient for the NHSCSP's success is quality assurance. The scrutiny given to medical interventions has increased recently. Would the early cervical cancer cytology screening programs have passed muster if they had required this sort of validation? Using information from the Victorian Cytology Screening Services Melbourne and other Australian screening programs to guide its formulation, Australia's evidence‐based program differs from the NHSCSP in several ways. The screening interval is 2 years, liquid‐based technology is not funded, and human papillomavirus (HPV)‐DNA testing for the triage of atypical lesions has not been sanctioned in Australia. Albrow et al allude to the possible introduction in the future of HPV‐DNA testing as a primary screening tool. Cancer (Cancer Cytopathol) 2012;. © 2012 American Cancer Society.
Cervical cytology screening programs: Similarities and differences between the United States and United Kingdom systems
Authors: Wilbur David C.
Published: February 2012

The United States and United Kingdom have cervical cancer screening programs that developed many similar and contrasting characteristics based on circumstances unique to each society. These features, their origins, and potential futures are presented.
Diagnostic value of K‐ras mutation analysis for pancreaticobiliary cytology specimens with indeterminate diagnosis
Authors: Cai Guoping , Mahooti Sepi , Lipata Fredilyn M. , Chhieng David , Hui Pei
Published: February 2012

BACKGROUND:

Fine‐needle aspiration and bile duct brushing cytology have been traditionally used for early detection of pancreaticobiliary malignancy. Quite frequently, the cytological interpretations of these specimens are indeterminate. In this retrospective study, we evaluated the diagnostic value of detecting K‐ras (v‐Ki‐ras2 Kirsten rat sarcoma viral oncogene homolog) mutation in pancreaticobiliary cytology specimens that had equivocal cytological diagnoses.

METHODS:

A total of 129 cases that had indeterminate cytology diagnoses, K‐ras mutational analysis, and histopathological follow‐up were retrieved. The cytological interpretations, histopathological diagnoses, and K‐ras mutation results were reviewed and analyzed.

RESULTS:

Overall, the sensitivity and specificity of K‐ras mutation for detection of pancreaticobiliary malignancy including adenocarcinoma, intraductal papillary mucinous neoplasm, and mucinous cystic neoplasm were 57% and 94%, respectively. The positive and negative predictive values of K‐ras mutation for the presence of pancreaticobiliary malignancy were 94% and 60%, respectively.

CONCLUSIONS:

The results demonstrate that K‐ras mutation has a high predictive value for malignancy in patients with indeterminate pancreaticobiliary cytology and should be included as an important adjuvant diagnostic marker. It should be noted that a negative K‐ras mutation result does not rule out malignancy, and K‐ras mutation can be detected, although infrequently, in morphologically benign conditions. Cancer (Cancer Cytopathol) 2012. © 2012 American Cancer Society.
Towards the optimal synchronization granularity for dynamic scheduling of pipelined computations on heterogeneous computing systems
Authors: Riakiotakis I. , Ciorba F. M. , Andronikos T. , Papakonstantinou G. , Chronopoulos A. T.
Published: February 2012

Loops are the richest source of parallelism in scientific applications. A large number of loop scheduling schemes have therefore been devised for loops with and without data dependencies (modeled as dependence distance vectors) on heterogeneous clusters. The loops with data dependencies require synchronization via cross‐node communication. Synchronization requires fine‐tuning to overcome the communication overhead and to yield the best possible overall performance. In this paper, a theoretical model is presented to determine the granularity of synchronization that minimizes the parallel execution time of loops with data dependencies when these are parallelized on heterogeneous systems using dynamic self‐scheduling algorithms. New formulas are proposed for estimating the total number of scheduling steps when a threshold for the minimum work assigned to a processor is assumed. The proposed model uses these formulas to determine the synchronization granularity that minimizes the estimated parallel execution time. The accuracy of the proposed model is verified and validated via extensive experiments on a heterogeneous computing system. The results show that the theoretically optimal synchronization granularity, as determined by the proposed model, is very close to the experimentally observed optimal synchronization granularity, with no deviation in the best case, and within 38.4% in the worst case. Copyright © 2012 John Wiley & Sons, Ltd.
Sigiri: uniform resource abstraction for grids and clouds
Authors: Withana Eran Chinthaka , Plale Beth
Published: February 2012

With the maturation of grid computing facilities and recent explosion of cloud computing data centers, midscale computational science has more options than ever before to satisfy computational needs. But heterogeneity brings complexity. We propose a simple abstraction for interaction with heterogeneous resource managers spanning grid and cloud computing and on features that make the tool useful for the midscale physical or natural scientist. Key strengths of the abstraction are its support for multiple standard job specification languages, preservation of direct user interaction with the service, removing the delay that can come through layers of services, and the predictable behavior under heavy loads. Copyright © 2012 John Wiley & Sons, Ltd.
Interpersonal Psychotherapy for Eating Disorders
Authors: Murphy Rebecca , Straebler Suzanne , Basden Shawnee , Cooper Zafra , Fairburn Christopher G.
Published: February 2012

Interpersonal psychotherapy (IPT) is a leading evidence‐based treatment for those eating disorders in which binge eating is a feature. This article begins with a consideration of the rationale for using IPT to treat patients with eating disorders. This is followed by a review of the evidence supporting its use and a brief description of treatment including an illustrative clinical case vignette. The article closes with a discussion of possible future directions for research on IPT for eating disorders. Copyright © 2012 John Wiley & Sons, Ltd.

Key Practitioner Message

IPT for eating disorders (IPT‐ED) closely resembles IPT for depression and primarily focuses on current interpersonal problems. It is well suited for helping patients to address interpersonal difficulties which appear to be maintaining the eating disorder.
Any Indication for Bias due to Participation? Comparison of the Effects of a Parent Management Training Rated by Participating and Non‐Participating Parents
Authors: Hautmann Christopher , Hoijtink Herbert , Eichelberger Ilka , Görtz‐Dorten Anja , Hanisch Charlotte , Plück Julia , Walter Daniel , Döpfner Manfred
Published: February 2012

Ratings of parents that have participated in a parent training for child externalizing behaviour problems might be biased (e.g., they may report symptom reduction to reward their own endeavours for attending the training). The potential for bias in parent ratings was investigated in a secondary analysis of an effectiveness study of a parent management training for children (aged 3–10 years) with externalizing behaviour problems under routine care conditions. For the 56 families included in the current analysis, we compared the ratings of training participants (predominately mothers) and training non‐participants (predominately fathers). A 3‐month waiting period prior to treatment served as the control condition. Outcome measures were attention problems and conduct problems of the children and perceived parental self‐efficacy rated by both the mothers and fathers. Child attention problems and conduct problems both decreased significantly during the treatment period for participating and non‐participating parents, and the changes in ratings during treatment were of a similar magnitude for participants compared with non‐participants. Taking into account the methodological limitations of the current analysis, no indication was found that treatment effects are strongly biased due to participation in the training. Copyright © 2012 John Wiley & Sons, Ltd.

Key Practitioner Messages

Previous positive findings of mothers' and fathers' ratings on parent management training for children with externalizing problem behaviour have mostly come from parents who also attended the training.

For child behavioural problems, the results of the current analysis demonstrate similar perceived changes by parents who did and did not participate in the training.

Our findings underscore the relevance and importance of parent ratings for treatment evaluation.