bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary investigations into the use of microwave energy for reversible stunning of sheep
Authors: Small A , McLean D , Keates H , Owen JS , Ralph J
Published: April 2013

Stunning prior to slaughter is commonly used to render the animal insensible to pain. However, for certain markets, stunning is disallowed, unless the animal can fully recover if not slaughtered. There are very few available methods of inducing a fully recoverable stun. This preliminary study investigates the potential for microwave energy application to be used to induce a recoverable stun in sheep. Cadaver heads were used to demonstrate that brain temperature could be raised to a point at which insensibility would be expected to occur (44°C). Trials on four anaesthetised sheep confirmed this finding in a live animal model where brain temperatures between 43 and 48°C were achieved with 20 s of microwave energy application. Although the applicator and process variables require some further development, this technology seems eminently suitable for use as an alternative method of inducing a recoverable stun.
The Use of Horizontal and Vertical Angles in Terrestrial Navigation
Authors: Lušić Zvonimir
Published: April 2013

The methods of determining a ship’s position in terrestrial navigation by using vertical and horizontal angles are nowadays rarely used. The reason is the relative complexity of the procedure and the lack of accuracy of some methods. Different methods of using horizontal and vertical angles to obtain the line of position (LOP) will be presented in this paper, as well as the occurring errors and recommendations for use. In this paper, the sextant will be considered a basic instrument for measuring horizontal and vertical angles. The sextant allows a very precise measuring of angles from which very accurate lines of position can be obtained.
Simulation and Optimization of Independent Renewable Energy Hybrid System
Authors: Gudelj Anita , Krčum Maja
Published: April 2013

In this paper the majority of research refers to the optimal configuration of hybrid system that uses renewable energy and wind energy and solar radiation in association with diesel aggregate and batteries. These independent energy systems (hybrid systems) are becoming popular due to increasing energy costs and decreasing prices of turbines and Photo-Voltaic (PV) panels. But the only drawback is that their outputs depend upon the climatic conditions. The main goal to optimization a hybrid system is necessary to obtain the configuration of the system as well as the control strategy that minimizes the total cost through the useful life of the installation to meet the desired consumption and/or the pollutant emissions. The HOGA (Hybrid Optimizations by Genetic Algorithms) program was used to simulate the system operation and calculate technical economic parameters for each configuration. The system configuration of the hybrid is derived based on the data of wind and solar radiation which are related to the southern Croatian coast, as on a theoretical annual load at an observed location. Also, technical data for components are taken from the manufacturer’s specifications (datasheet). In this paper the advantages and disadvantages of commonly used types of generators (synchronous and asynchronous generators) are presented. Results show that the hybrid systems have considerable reductions in carbon emission and cost of the system.
Interdisciplinary Climate Change Collaborations Are Essential for Early‐Career Scientists
Authors: Gornish Elise S. , Hamilton Jill A. , Barberán Albert , Benito Blas M. , Binzer Amrei , DeMeester Julie E. , Gruwez Robert , Moreira Bruno , Taheri Shirin , Tomiolo Sara , Vinagre Catarina , Vuarin Pauline , Weaver Jennifer
Published: April 2013

Climate change research is an interdisciplinary field, and understanding its social, political, and environmental implications requires integration across fields of research where different tools may be used to address common concerns [Baerwald, 2010]. One of the many advantages of interdisciplinary approaches is that they open communication between complementary fields, filling knowledge gaps and facilitating progression within both individual fields and the broader field of climate change research [Ludwig et al., 2011].
A seismometer in orbit around Earth
Authors: Balcerak Ernie
Published: April 2013

Most people think of seismometers as ground‐based instruments, but earthquakes also can be detected by satellites, as demonstrated by Garcia et al. using data from the European Space Agency's Gravity field and steady‐state Ocean Circulation Explorer (GOCE) mission. The authors call GOCE “the first seismometer in orbit around the Earth” because it was able to detect infrasonic waves in the atmosphere generated by the 2011 Tohoku earthquake.
Synthesis, Cytotoxicity, and Pro‐Apoptosis Activity of Etodolac Hydrazide Derivatives as Anticancer Agents
Authors: Çıkla Pelin , Özsavcı Derya , Bingöl‐Özakpınar Özlem , Şener Azize , Çevik Özge , Özbaş‐Turan Suna , Akbuğa Jülide , Şahin Fikrettin , Küçükgüzel Ş. Güniz
Published: April 2013

Etodolac hydrazide and a novel series of etodolac hydrazide‐hydrazones3–15and etodolac 4‐thiazolidinones16–26were synthesized in this study. The structures of the new compounds were determined by spectral (FT‐IR,1H NMR,13C NMR, HREI‐MS) methods. Some selected compounds were determined at one dose toward the full panel of 60 human cancer cell lines by the National Cancer Institute (NCI, Bethesda, USA). 2‐(1,8‐Diethyl‐1,3,4,9‐tetrahydropyrano[3,4‐b]indole‐1‐yl)acetic acid[(4‐chlorophenyl)methylene]hydrazide9demonstrated the most marked effect on the prostate cancer cell line PC‐3, with 58.24% growth inhibition at 10−5 M (10 µM). Using the MTT colorimetric method, compound9was evaluatedin vitroagainst the prostate cell line PC‐3 and the rat fibroblast cell line L‐929, for cell viability and growth inhibition at different doses. Compound9exhibited anticancer activity with an IC50value of 54 µM (22.842 µg/mL) against the PC‐3 cells and did not display any cytotoxicity toward the L‐929 rat fibroblasts, compared to etodolac. In addition, this compound was evaluated for caspase‐3 and Bcl‐2 activation in the apoptosis pathway, which plays a key role in the treatment of cancer.
New Arylpiperazines with Flexible versus Partly Constrained Linker as Serotonin 5‐HT1A/5‐HT7 Receptor Ligands
Authors: Kowalski Piotr , Mitka Katarzyna , Jaśkowska Jolanta , Duszyńska Beata , Bojarski Andrzej J.
Published: April 2013

A series of new long‐chain arylpiperazine (LCAP) derivatives with flexible and partly constrained alkyl linker were synthesized and investigated in vitro as potential serotonin 5‐HT1A and 5‐HT7 receptor ligands. The compounds were prepared by a two‐step procedure using naphthalimide and 2H‐1,3‐benzoxazine‐2,4(3H)‐dione as imides, and 1‐(2‐methoxyphenyl)piperazine (o‐OMe‐PhP) and 1,2,3,4‐tetrahydroisoquinoline (THIQ) as amine pharmacophores. Modifications of the spacer structure included introduction of flexible penta‐ and hexamethylene chains as well as partly constrained m‐ and p‐xylyl moieties. In general, the new compounds were more active at the 5‐HT1A than at the 5‐HT7 receptor, and the o‐OMe‐PhP derivatives displayed higher affinities than their respective THIQ analogs. The spacer modifications had little effect on the observed in vitro activities. Within the o‐OMe‐PhP series, except for a small binding reduction for ligands containing the m‐xylyl moiety, there was no substantial change in the compounds' potency at both receptors, while for the THIQ derivatives a clear structure–activity relationship was visible only for the interaction of the compounds with the 5‐HT7 receptor, which strongly favored flexible analogs.
Individual Differences in Risky Decision Making: A Meta‐analysis of Sensation Seeking and Impulsivity with the Balloon Analogue Risk Task
Authors: Lauriola Marco , Panno Angelo , Levin Irwin P. , Lejuez Carl W.
Published: April 2013

To represent the state‐of‐the‐art in an effort to understand the relation between personality and risk taking, we selected a popular decision task with characteristics that parallel risk taking in the real world and two personality traits commonly believed to influence risk taking. A meta‐analysis is presented based on 22 studies of the Balloon Analogue Risk Task from which correlations with sensation seeking and impulsivity assessments could be obtained. Results calculated on a total of 2120 participants showed that effect size for the relation of sensation seeking with risk taking was in the small–moderate range ( = .14), whereas the effect size for impulsivity was just around the small effect size threshold ( = .10). Although we considered participants' demographics as moderators, we found only significantly larger effect sizes for the older adolescents and young adults compared with other ages. The findings of the present review supported the view that inconsistencies in personality–risk research were mostly due to random fluctuations of specific effect sizes, rather than to lack of theoretical ties or to measurement unreliability. It is also concluded that studies aimed at relating individual differences in personality to performance in experimental decision tasks need an appropriate sample size to achieve the power to produce significant results. Copyright © 2013 John Wiley & Sons, Ltd.
Comparison of the accuracy of Hybrid Capture II and polymerase chain reaction in detecting clinically important cervical dysplasia: a systematic review and meta‐analysis
Authors: Luu Hung N. , Dahlstrom Kristina R. , Mullen Patricia Dolan , VonVille Helena M. , Scheurer Michael E.
Published: April 2013

The effectiveness of screening programs for cervical cancer has benefited from the inclusion of Human papillomavirus (HPV) DNA assays; which assay to choose, however, is not clear based on previous reviews. Our review addressed test accuracy of Hybrid Capture II (HCII) and polymerase chain reaction (PCR) assays based on studies with stronger designs and with more clinically relevant outcomes. We searched OvidMedline, PubMed, and the Cochrane Library for English language studies comparing both tests, published 1985–2012, with cervical dysplasia defined by the Bethesda classification. Meta‐analysis provided pooled sensitivity, specificity, and 95% confidence intervals (CIs); meta‐regression identified sources of heterogeneity. From 29 reports, we found that the pooled sensitivity and specificity to detect high‐grade squamous intraepithelial lesion (HSIL) was higher for HCII than PCR (0.89 [CI: 0.89–0.90] and 0.85 [CI: 0.84–0.86] vs. 0.73 [CI: 0.73–0.74] and 0.62 [CI: 0.62–0.64]). Both assays had higher accuracy to detect cervical dysplasia in Europe than in Asia‐Pacific or North America (diagnostic odd ratio – dOR = 4.08 [CI: 1.39–11.91] and 4.56 [CI: 1.86–11.17] for HCII vs. 2.66 [CI: 1.16–6.53] and 3.78 [CI: 1.50–9.51] for PCR) and accuracy to detect HSIL than atypical squamous cells of undetermined significance (ASCUS)/ low‐grade squamous intraepithelial lesion (LSIL) (HCII‐dOR = 9.04 [CI: 4.12–19.86] and PCR‐dOR = 5.60 [CI: 2.87–10.94]). For HCII, using histology as a gold standard results in higher accuracy than using cytology (dOR = 2.87 [CI: 1.31–6.29]). Based on higher test accuracy, our results support the use of HCII in cervical cancer screening programs. The role of HPV type distribution should be explored to determine the worldwide comparability of HPV test accuracy.
Path Length Determines the Tunneling Decay of Substituted Carbenes
Authors: Kästner Johannes
Published: April 2013

Quantum mechanical tunneling of atoms allows chemical reactions to proceed through barriers too high for thermally activated processes. This causes hydroxycarbenes to decay rapidly and at a temperature‐independent rate even at 11 K. In methylhydroxycarbene, tunneling causes decay through a mechanism that reveals a high but thin barrier rather than an alternative with a lower but broader barrier. No accurate estimates of the widths of such barriers and the lengths of tunneling paths were available. Herein, such a measure is provided by calculating the length of the tunneling paths by using instanton theory. Potential energies are provided by density functional theory verified by explicitly correlated coupled cluster CCSD(T) energies. Our results explain the decay efficiency in the known cases and suggest new substitutions to tune the effects of barrier widths and heights. Fluorination and replacement of the hydroxyl group by a thiol group change the qualitative character of the decay. Methylaminocarbene is predicted to be stable for thousands of years.
Stereoselective Aldol Addition to Rhenium(I) Complexes and Reversible Dimerization with Epimerization of the Metal Center
Authors: Álvarez Celedonio M. , Carrillo Romen , García‐Rodríguez Raúl , Miguel Daniel
Published: April 2013

Herein, we report several examples of stereoselective aldol additions of aldehydes or ketones to ReI tricarbonyl complexes to form monomeric derivatives in good yields. The metal‐centered chirality defines the final stereochemistry of the carbon atom of the monomeric ReI complex after the addition. However, it cannot control the resulting stereochemistry of the enolate part, and thus, if the α‐carbon atom of the reagent is prochiral, a mixture of diastereoisomers is obtained. On the other hand, all of the monomeric complexes can be reversibly dimerized in basic media to form cis dimers, for which an epimerization of the metal‐centered chirality is required in order to avoid steric congestion. All of these results are supported by exhaustive crystallographic analysis.
Structural Principles and Thermoelectric Properties of Polytypic Group 14 Clathrate‐II Frameworks
Authors: Karttunen Antti J. , Fässler Thomas F.
Published: April 2013

We have investigated the structural principles and thermoelectric properties of polytypic group 14 clathrate‐II frameworks using quantum chemical methods. The experimentally known cubic 3C polytype was found to be the energetically most favorable framework, but the studied hexagonal polytypes (2 H, 4 H, 6 H, 8 H, 10 H) lie energetically close to it. In the case of germanium, the energy difference between the 3C and 6H clathrate‐II polytypes is ten times smaller than the difference between the experimentally known 3C‐Ge (α‐Ge) and 4H‐Ge polytypes. The thermoelectric properties of guest‐occupied clathrate‐II structures were investigated for compositions Na–Rb–Ga–Ge and Ge–As–I. The clathrate‐II structures show promising thermoelectric properties and the highest Seebeck coefficients and thermoelectric power factors were predicted for the 3C polytype. The structural anisotropy of the largest studied hexagonal polytypes affects their thermoelectric power factors by over a factor of two.
Functionalization of SnO2 Crystals with a Covalently‐Assembled Porphyrin Monolayer
Authors: Cristaldi Domenico A. , Gulino Antonino
Published: April 2013

The functionalization of micro‐ and nano‐sized metal‐oxide powders offers many advantages because of their large surface areas and, therefore, the large number of functional molecules that can be grafted onto the grain surfaces. Porphyrin molecules on large band‐gap semiconducting metal oxides represent key materials for many different optical and electronic applications. Herein, we have proposed a general two‐step procedure for the functionalization of metal‐oxide crystals with dye‐sensitizers. In particular, we functionalized SnO2 nanoparticles with a monolayer of the bifunctional trichloro[4‐(chloromethyl)phenyl]silane. Then, a monolayer of 5,10,15,20‐tetrakis(4‐hydroxyphenyl)‐21H,23H‐porphyne was covalently bound to the silanized SnO2 grains. IR, UV/Vis, and luminescence measurements were used for optical characterization. The measured footprint of the grafted porphyrin molecules indicated total surface coverage of the grains. The surface electronic characterization was performed by using X‐ray photoelectron spectroscopy. Emission measurements revealed two strong bands at 664.1 and 721.0 nm that were attributed to the porphyrin monolayer assembled on the surface of the SnO2 crystals.
Phase error analysis in CMOS injection‐coupled LC quadrature oscillator (IC‐QO)
Authors: Ghonoodi Hojat , Miar‐Naimi Hossein
Published: April 2013

This paper presents a novel approach to study the phase error in source injection coupled quadrature oscillators (QOs). Like other LC QOs, the mismatches between LC tanks are the main source of phase error in this oscillator. The QO is analyzed where the phase error and oscillation frequency are derived in terms of circuit parameters. The proposed analysis shows that the output phase error is a function of injection current and the current of source equivalent capacitor. As a result, it is shown that increasing of tail current and LC tank quality factor decreases the phase error. Derived equations show that the phase error can be cancelled and even controlled by adjusting bias currents. To evaluate the proposed analysis and consequent designed QO, a 5.5 GHz CMOS QO is designed and simulated using the practical 0.18 µm TSMC CMOS technology. The experiments show good agreement between analytical equations and simulation results. Copyright © 2013 John Wiley & Sons, Ltd.
Immunoreactive LH in long‐term frozen human urine samples
Authors: Singh Gurmeet Kaur Surindar , Jimenez Mark , Newman Ron , Handelsman David J.
Published: April 2013

Urine provides a convenient non‐invasive alternative to blood sampling for measurement of certain hormones. Urinary luteinizing hormone (LH) measurements have been used for endocrinology research and anti‐doping testing. However, the commercially available LH immunoassays are developed and validated for human blood samples but not urine so that LH assays intended for use with urine samples need thorough validation. Therefore, the present study evaluated the measurement of urinary LH immunoreactivity using previously validated immunofluorometric (IF) and immunochemiluminometric (ICL) LH assays after prolonged frozen storage. LH was measured in serial urine samples following administration of a single injection of one of two doses of recombinant human chorionic hormone (rhCG) with assays run at the end of study (2008) and again after four years of frozen (‐20 °C) storage where samples were stored without adding preservatives. The ICL assay showed quantitatively reproducible LH measurements after prolonged ‐20 °C storage. However, the IF immunoassay gave consistently lower LH levels relative to ICL (2008) with a further proportionate reduction after four years of sample storage (2012). Yet, both the assays displayed similar patterns of the time‐course of urine LH measurement both before and after four years of frozen storage. In conclusion, we found that both immunoassays are suitable for urinary LH measurements with ICL assay being more robust for quantitative urinary LH measurement such as for anti‐doping purposes, whereas the IF could be applicable for research studies where urine LH levels are compared within‐study but not in absolute terms. Copyright © 2013 John Wiley & Sons, Ltd.
Activation of canonical Wnt/β‐catenin signaling stimulates proliferation in neuromasts in the zebrafish posterior lateral line
Authors: Head Jeffery R. , Gacioch Leah , Pennisi Matthew , Meyers Jason R.
Published: April 2013

Background: The posterior lateral line in zebrafish develops from a migrating primordium that deposits clusters of cells that differentiate into neuromasts at regular intervals along the trunk. The deposition of these neuromasts is known to be coordinated by Wnt and FGF signals that control the proliferation, migration, and organization of the primordium. However, little is known about the control of proliferation in the neuromasts following their deposition. Results: We show that pharmacological activation of the Wnt/β‐catenin signaling pathway with 1‐azakenpaullone upregulates proliferation in neuromasts post‐deposition. This results in increased size of the neuromasts and overproduction of sensory hair cells. We also show that activation of Wnt signaling returns already quiescent supporting cells to a proliferative state in mature neuromasts. Additionally, activation of Wnt signaling increases the number of supporting cells that return to the cell cycle in response to hair cell damage and the number of regenerated hair cells. Finally, we show that inhibition of Wnt signaling by overexpression of dkk1b suppresses proliferation during both differentiation and regeneration. Conclusions: These data suggest that Wnt/β‐catenin signaling is both necessary and sufficient for the control of proliferation of lateral line progenitors during development, ongoing growth of the neuromasts, and hair cell regeneration. Developmental Dynamics 242:832–846, 2013. © 2013 Wiley Periodicals, Inc.
Duplication and population dynamics shape historic patterns of selection and genetic variation at the major histocompatibility complex in rodents
Authors: Winternitz Jamie C. , Wares John P.
Published: April 2013

Genetic variation at the major histocompatibility complex (MHC) is vitally important for wildlife populations to respond to pathogen threats. As natural populations can fluctuate greatly in size, a key issue concerns how population cycles and bottlenecks that could reduce genetic diversity will influenceMHCgenes. Using 454 sequencing, we characterized genetic diversity at theDRBClassIIlocus in montane voles (Microtus montanus), a North American rodent that regularly undergoes high‐amplitude fluctuations in population size. We tested for evidence of historic balancing selection, recombination, and gene duplication to identify mechanisms maintaining allelic diversity. Counter to our expectations, we found strong evidence of purifying selection acting on theDRBlocus in montane voles. We speculate that the interplay between population fluctuations and gene duplication might be responsible for the weak evidence of historic balancing selection and strong evidence of purifying selection detected. To further explore this idea, we conducted a phylogenetically controlled comparative analysis across 16 rodent species with varying demographic histories andMHCduplication events (based on the maximum number of alleles detected per individual). On the basis of phylogenetic generalized linear model‐averaging, we found evidence that the estimated number of duplicated loci was positively related to allelic diversity and, surprisingly, to the strength of purifying selection at theDRBlocus. Our analyses also revealed that species that had undergone population bottlenecks had lower allelic richness than stable species. This study highlights the need to consider demographic history and genetic structure alongside patterns of natural selection to understand resulting patterns of genetic variation at theMHC.
Convergence of tree water use and hydraulic architecture in water‐limited regions: a review and synthesis
Authors: Zeppel Melanie
Published: April 2013

Global vegetation models are used to estimate water and carbon fluxes in current and future climates. To accurately estimate these fluxes, it is crucial to incorporate tree processes, such as transpiration. Some models accurately predict fluxes in well‐watered conditions; however, our ability to predict responses of trees when water availability is limited remains restricted. Including mechanistic responses of trees during drought in models will improve estimates of water and carbon fluxes.

Estimating water fluxes over large spatial scales may be calculated by combining (1) remotely sensed estimates of evapotranspiration with (2) knowledge of whether tree water use for a particular forest type or plant functional type follows universal scaling rules. There is little knowledge of whether universal scaling rules apply to water‐limited ecosystems.

This review examines ‘convergence’ in relationships among tree water use, leaf area, and tree size, using Australian broad‐leaved evergreen vegetation as a case study. Broad‐leaved evergreen is a plant functional type commonly used in global vegetation models. If convergence is observed among leaf area and water use relationships for different species within this plant functional type, this would provide a powerful tool for scaling ecohydrological processes. This work tests the hypothesis that tree water use (Q) converges along a common relationship with leaf area for a continent‐wide range of species (n = 21), spanning a 100‐fold difference in size across broad‐leaved evergreens, including Acacia, Corymbia, and Eucalyptus as well as Callitris.

Remarkably, the slope of the relationship between tree water use and leaf area was similar for the broad‐leaved evergreen genus, Eucalyptus, despite different slopes in relationships among diameter at breast height, leaf area, sapwood area, and Q. Realistic modelling of water and carbon fluxes requires an understanding of physiological mechanisms influencing Q, for each plant functional type, and for these mechanisms to be incorporated into vegetation models. Copyright © 2013 John Wiley & Sons, Ltd.
CD39 is involved in mediating suppression by Mycobacterium bovisBCG‐activated human CD8+CD39+ regulatory T cells
Authors: Boer Mardi C. , van Meijgaarden Krista E. , Bastid Jérémy , Ottenhoff Tom H.M. , Joosten Simone A.
Published: April 2013

Regulatory T (Treg) cells can balance normal tissue homeostasis by limiting inflammatory tissue damage, e.g. during pathogen infection, but on the other hand can also limit protective immunity induced during natural infection or following vaccination. Because most studies have focused on the role of CD4+ Treg cells, relatively little is known about the phenotype and function of CD8+ Treg cells, particularly in infectious diseases. Here, we describe for the first time the expression of CD39 (E‐NTPDase1) on Mycobacterium‐activated human CD8+ T cells. These CD8+CD39+ T cells significantly co‐expressed the Treg markers CD25, Foxp3, lymphocyte activation gene‐3 (LAG‐3), and CC chemokine ligand 4 (CCL4), and suppressed the proliferative response of antigen‐specific CD4+ T helper‐1 (Th1) cells. Pharmacological or antibody mediated blocking of CD39 function resulted in partial reversal of suppression. These data identify CD39 as a novel marker of human regulatory CD8+ T cells and indicate that CD39 is functionally involved in suppression by CD8+ Treg cells.
Recent Developments in Low‐Dimensional Copper(II) Molecular Magnets
Authors: Landee Christopher P. , Turnbull Mark M.
Published: April 2013

Invited for the cover of this issue is the group (current and recent students) of chemist Mark M. Turnbull and physicist Christopher P. Landee at Clark University. The image shows the types of low‐dimensional lattices under study and the everyday objects that inspired them.
Phosphane‐Catalyzed [3+2] Cycloaddition Reaction of Allenoate and Cyclic Imines: A Simple and Efficient Method for Synthesis of Benzo‐Fused Cyclic Sulfamidate Heterocycles
Authors: Wang You‐Qing , Zhang Yongna , Dong Haina , Zhang Jie , Zhao Jin
Published: April 2013

By using a phosphane as an organocatalyst, an efficient synthesis of benzo‐fused cyclic sulfamidate heterocycles has been developed through a cycloaddition reaction of allenoate and cyclic imines including cyclic trifluoromethyl ketimine, which gave high yields (71–97 %). The reaction could also be conveniently performed on a gram scale. Furthermore, some simple transformations of the sulfamidate heterocycle products have been disclosed to obtain functional amines. An asymmetric variant of this reaction was also tried by screening several commercially available chiral phosphane ligands as organocatalysts, and up to 36 % ee was achieved.
Role of two stage pyrolysis in fire growth on flexible polyurethane foam slabs
Authors: Pitts William M.
Published: April 2013

A series of experiments designed to characterize fire behavior on flat 1.2 m × 1.2 m samples of commercial non‐fire‐retarded flexible polyurethane foam were performed. Time‐resolved heat release and mass loss rates were measured. Experimental parameters varied, including foam thickness (5.1 and 10.2 cm) and burning angle (+25°, +12.5°, 0°, −12.5°, and −25°). Polyurethane foam is typically produced by reacting a multifunctional isocyanate with a polyol. The foam used here was formed by reacting toluene diisocyanate and a polyol based on a condensed polyether of polypropylene oxide. Earlier cone calorimeter studies of this foam had revealed a clear two stage pyrolysis behavior in which the heated foam first released a gaseous fuel derived from the isocyanate component, while leaving behind a liquid produced primarily from the polyol, which only gasified and burned following additional heating. The subsequent burning behavior of the polyol‐derived liquid is shown in this work to play a crucial role in the maximum heat release rate and total heat released by the fires spreading across the foam slabs. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
Relative importance of tropical SST anomalies in forcing East Asian summer monsoon circulation
Authors: Fan Lei , Shin Sang‐Ik , Liu Qinyu , Liu Zhengyu
Published: April 2013

The relative importance of tropical SST anomalies to the dominant variability of East Asian Summer Monsoon (EASM) circulation is investigated using an atmospheric general circulation model and a linear inverse model. It is found that the cooling over the central tropical Pacific is crucial in developing and maintaining the summertime northwest Pacific anticyclones, associated with the EASM precipitation. In this regard, the previously suggested El Niño event in the preceding winter and accompanying tropical Indian Ocean warming alone may not be enough to predict the strength of EASM circulation. Instead, monitoring and predicting the evolution of sea surface temperature anomalies in the central tropical Pacific, especially in spring to summer, may greatly improve the prediction of EASM circulation.
Evapotranspiration amplifies European summer drought
Authors: Teuling Adriaan J. , Van Loon Anne F. , Seneviratne Sonia I. , Lehner Irene , Aubinet Marc , Heinesch Bernard , Bernhofer Christian , Grünwald Thomas , Prasse Heiko , Spank Uwe
Published: April 2013

Drought is typically associated with a lack of precipitation, whereas the contribution of evapotranspiration and runoff to drought evolution is not well understood. Here we use unique long‐term observations made in four headwater catchments in central and western Europe to reconstruct storage anomalies and study the drivers of storage anomaly evolution during drought. We provide observational evidence for the “drought‐paradox” in that region: a consistent and significant increase in evapotranspiration during drought episodes, which acts to amplify the storage anomalies. In contrast, decreases in runoff act to limit storage anomalies. Our findings stress the need for the correct representation of evapotranspiration and runoff processes in drought indices.
Effects of octreotide therapy in progressive head and neck paragangliomas: Case series
Authors: van Hulsteijn Leonie T. , van Duinen Nicolette , Verbist Berit M. , Jansen Jeroen C. , van der Klaauw Agatha A. , Smit Jan W. A. , Corssmit Eleonora P. M.
Published: April 2013

Background

Octreotide, a somatostatin analog, may be beneficial in the treatment of head and neck paragangliomas (HNPGLs).

Methods

We conducted a nonblinded, prospective intervention study. During 1 year, patients received a monthly intramuscular injection of 30 mg octreotide. Pretreatment and posttreatment tumor volumes were assessed by MRI, urinary catecholamine secretion was measured, and HNPGL‐related signs and symptoms were recorded.

Results

In 1 of 4 included patients with HNPGL, a stabilization of tumor growth was observed after octreotide therapy. In 1 patient, octreotide therapy was discontinued before the end of the study because of potential side effects. No improvements in HNPGL‐related signs and symptoms were observed.

Conclusion

In 1 of 4 patients, HNPGL tumor growth velocity was reduced after octreotide therapy. Research assessing the effects of somatostatin analogues targeting different somatostatin receptor subtypes or combined with other therapies may offer new possibilities for the treatment of HNPGLs. © 2013 Wiley Periodicals, Inc. Head Neck 35: E391–E396, 2013
Disruption of LRP6 in osteoblasts blunts the bone anabolic activity of PTH
Authors: Li Changjun , Xing Qiujuan , Yu Bing , Xie Hui , Wang Weishan , Shi Chenhui , Crane Janet L , Cao Xu , Wan Mei
Published: April 2013

Mutations in low-density lipoprotein receptor-related protein 6 (LRP6) are associated with human skeletal disorders. LRP6 is required for parathyroid hormone (PTH)-stimulated signaling pathways in osteoblasts. We investigated whether LRP6 in osteoblasts directly regulates bone remodeling and mediates the bone anabolic effects of PTH by specifically deleting LRP6 in mature osteoblasts in mice (LRP6 KO). Three-month-old LRP6 KO mice had a significant reduction in bone mass in the femora secondary spongiosa relative to their wild-type littermates, whereas marginal changes were found in femoral tissue of 1-month-old LRP6 KO mice. The remodeling area of the 3-month-old LRP6 KO mice showed a decreased bone formation rate as detected by Goldner's Trichrome staining and calcein double labeling. Bone histomorphometric and immumohistochemical analysis revealed a reduction in osteoblasts but little change in the numbers of osteoclasts and osteoprogenitors/osteoblast precursors in LRP6 KO mice compared with wild-type littermates. In addition, the percentage of the apoptotic osteoblasts on the bone surface was higher in LRP6 KO mice compared with wild-type littermates. Intermittent injection of PTH had no effect on bone mass or osteoblastic bone formation in either trabecular and cortical bone in LRP6 KO mice, whereas all were enhanced in wild-type littermates. Additionally, the anti-apoptotic effect of PTH on osteoblasts in LRP6 KO mice was less significant compared with wild-type mice. Therefore, our findings demonstrate that LRP6 in osteoblasts is essential for osteoblastic differentiation during bone remodeling and the anabolic effects of PTH. © 2013 American Society for Bone and Mineral Research.
Dynamics and structural changes of small water clusters on ionization
Authors: Lee Han Myoung , Kim Kwang S.
Published: April 2013

Despite utmost importance in understanding water ionization process, reliable theoretical results of structural changes and molecular dynamics (MD) of water clusters on ionization have hardly been reported yet. Here, we investigate the water cations [(H2O)n = 2–6+] with density functional theory (DFT), Möller–Plesset second‐order perturbation theory (MP2), and coupled cluster theory with single, double, and perturbative triple excitations [CCSD(T)]. The complete basis set limits of interaction energies at the CCSD(T) level are reported, and the geometrical structures, electronic properties, and infrared spectra are investigated. The characteristics of structures and spectra of the water cluster cations reflect the formation of the hydronium cation moiety (H3O+) and the hydroxyl radical. Although most density functionals fail to predict reasonable energetics of the water cations, some functionals are found to be reliable, in reasonable agreement with high‐level ab initio results. To understand the ionization process of water clusters, DFT‐ and MP2‐based Born‐Oppenheimer MD (BOMD) simulations are performed on ionization. On ionization, the water clusters tend to have an Eigen‐like form with the hydronium cation instead of a Zundel‐like form, based on reliable BOMD simulations. For the vertically ionized water hexamer, the relatively stable (H2O)5+ (5sL4A) cluster tends to form with a detached water molecule (H2O). © 2013 Wiley Periodicals, Inc.
The sonographic “coffee bean” sign helps distinguish an axillary neurofibroma from a lymphadenopathy
Authors: Song Sung Eun , Seo Bo Kyoung , Choi Jung‐Woo , Son Gil‐Soo , Cho Kyu Ran , Kim Baek Hyun
Published: April 2013

Axillary masses may represent various soft tissue tumors or lymphadenopathy. Neurofibromas are benign peripheral nerve sheath tumors and, while they are very uncommon, it is important to remember that neurogenic tumors arising from brachial plexus can develop in the axilla. We describe an axillary neurofibroma arising from the brachial plexus that presented with a “coffee bean sign” on sonography that distinguished it from axillary lymphadenopathy. © 2013 Wiley Periodicals, Inc. J Clin Ultrasound 42:33–37, 2014
Temporal and spatial dynamics of the regions 1 and 2 Birkeland currents during substorms
Authors: Clausen L. B. N. , H. Baker J. B. , Ruohoniemi J. M. , Milan S. E. , Coxon J. C. , Wing S. , Ohtani S. , Anderson B. J.
Published: April 2013

We use current density data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) to identify the location of maximum region 1 current at all magnetic local times (MLTs). We term this location the R1 oval. Comparing the R1 oval location with particle precipitation boundaries identified in DMSP data, we find that the R1 oval is located on average within 1° of particle signatures associated with the open/closed field line boundary (OCB) across dayside and nightside MLTs. We hence conclude that the R1 oval can be used as a proxy for the location of the OCB. Studying the amount of magnetic flux enclosed by the R1 oval during the substorm cycle, we find that the R1 oval flux is well organized by it: during the growth phase the R1 oval location moves equatorward as the amount of magnetic flux increases whereas after substorm expansion phase onset significant flux closure occurs as the R1 current location retreats to higher latitudes. For about 15 min after expansion phase onset, the amount of open magnetic flux continues to increase indicating that dayside reconnection dominates over nightside reconnection. In the current density data, we find evidence of the substorm current wedge and also show that the dayside R1 currents are stronger than their nightside counterpart during the substorm growth phase, whereas after expansion phase onset, the nightside R1 currents dominate. Our observations of the current distribution and OCB movement during the substorm cycle are in excellent agreement with the expanding/contracting polar cap paradigm.
Variability in eruption style and associated very long period events at Fuego volcano, Guatemala
Authors: Waite Gregory P. , Nadeau Patricia A. , Lyons John J.
Published: April 2013

Repeated short‐term deployments of seismic, infrasound, video, and gas‐emission instruments at Fuego volcano, Guatemala have revealed three types of very long period (VLP) events associated with conduit sealing, pressure accumulation, and release. In 2008, ash‐rich explosions issued from a vent on the western flank and produced one type of VLP (Type 1). Impulsive, bomb‐rich explosions from the summit vent in 2009 produced a shorter period VLP (Type 2), but also generated ash release. Type 3 VLP events occurred during ash‐free exhalations from the summit in 2008 and had waveform shapes similar to Type 2 events. Weak infrasound records for Type 1 explosions compared to Type 2 suggest lower pressures and higher magma porosity for Type 1. Type 3 events correlate with spikes in SO2 emission rate and are driven by partial sealing and rapid release of ash‐free gas at the summit vent. Variations in the VLP period may provide a new tool for monitoring conditions within the conduit.
Subcontinental sinking slab remnants in a spherical geometry mantle model
Authors: Quéré S. , Lowman, J.P. , Arkani‐Hamed J. , Roberts J.H. , Moucha R.
Published: April 2013

Comparisons of the paleogeographic record with seismic tomography sections from the mantle below Asia indicate that detached slab remnants associated with a range of ages since subduction spanning roughly 100 Myr appear to occupy mid‐mantle depths at different sites. More than one explanation for the observed spectrum of ages at similar depths may be plausible. To identify key parameters controlling the sinking rate of a slab, we examine the effects of mantle viscosity, Rayleigh number, and spherical geometry, as well as the role of slab properties, such as strike width, depth extent at the time of slab detachment, and slab rheology. We model scenarios featuring detached mantle slabs in 3‐D calculations and conclude that the initial depth extent of a subducted slab segment is a key parameter determining the rate at which the slab sinks. We estimate that stiff slabs are able to occupy mid‐mantle depths for ages ranging from approximately 35 to 150 Myr, depending on the initial depth extent of the slab at the time of its detachment from the lithosphere. This age range results from the time that different slab fragments require to cross the viscosity interface at the upper mantle/lower mantle boundary. In cases featuring mature slabs where the lower section of the slab has penetrated the lower mantle prior to detachment, entrainment by the deep sinking segment helps the young upper mantle section of the slab cross into the lower mantle much more quickly than a slab segment initially confined to the upper mantle.
Subtidal water flux through a multiple‐inlet system: Observations before and during a cold front event and numerical experiments
Authors: Li Chunyan
Published: April 2013

This paper examines the net transport through a multiple‐inlet bay under a combined force of strong wind and tide, with observations and a model experiment. The observations were made in central Georgia in Sapelo and Altamaha Sounds between 13 and 17 September 2000. Wind was weak in the beginning of the survey. An air pressure trough (as a weak cold front) passed the area on 16 September, when the wind changed to the northeast and increased in magnitude. This front was associated with a midlatitude cyclone in the New England area. This weather event with an episode of strong northeasterly winds prompted a numerical model experiment on an idealized three‐inlet bay, with a set of nonlinear 2‐D shallow water equations on an f plane, which provides some insight to the wind‐driven circulation under the presence of tidal forcing. It is found that tidally induced currents are small compared to wind‐induced flows. When the wind direction is not perpendicular to the alignment of the three inlets, the net outward flow tends to occur at the inlet farther away in the downwind direction. This is associated with a net inward transport in the inlet opposite of the downwind direction. As a result, the middle inlet has the minimum of the net flow. When the wind is perpendicular to the barrier islands, and if the three inlets have different maximum depth values, the deeper inlet tends to have a net flow against the wind, while the shallower inlet tends to have a net flow in the direction of the wind. Offshore (onshore) currents may develop outside of the inlet with outward (inward) flow, as an effect of fluxes through the inlets on the coastal ocean.
Comparison of observed and simulated tropical cumuliform clouds by CloudSat and NICAM
Authors: Dodson Jason B. , Randall David A. , Suzuki Kentaroh
Published: April 2013

We use CloudSat observations of boreal summer tropical ocean cumuliform clouds to evaluate the behavior of the non‐parameterized cumuliform clouds in the Nonhydrostatic Icosahedral Atmospheric Model (NICAM), with a particular emphasis on deep convective clouds (DCCs). The CloudSat cloud mask and radar reflectivity profiles for cumuliform clouds are sorted by large‐scale environmental variables taken from the Aqua satellite and NCEP/NCAR reanalysis. The variables are total precipitable water (TPW), sea surface temperature (SST), and 500 hPa vertical velocity (W500), representing the dynamical and thermodynamical environment in which the clouds form. The sorted CloudSat profiles are then compared with NICAM profiles simulated with the Quickbeam CloudSat simulator. We first use the cloud mask to examine the transition between shallow clouds and deep clouds rooted in the planetary boundary layer. We find that NICAM simulates this transition fairly realistically. However, the transition occurs at slightly higher TPW and W500 values than the observations show. This may be indication of NICAM's inability to represent the formation of isolated narrow DCCs in marginally favorable environments. We then use simple metrics of the DCC‐only radar reflectivity profiles (cloud top height, cloud top reflectivity gradient, maximum reflectivity) to quantitatively compare the observations with NICAM. The results show that while the observed and simulated results agree generally, there are some disagreements in key respects. There is disagreement on the sensitivity of cloud top height to environmental conditions and on the transition between shallow and deep clouds in environments marginally suitable for deep convection.
A climatology of elevated stratopause events in the whole atmosphere community climate model
Authors: Chandran A. , Collins R. L. , Garcia R. R. , Marsh D. R. , Harvey V. L. , Yue J. , de la Torre L.
Published: April 2013

Elevated stratopause (ES) events occurring during Northern Hemisphere winter are identified in four climate simulations of the period 1953–2005 made with the Whole Atmosphere Community Climate Model (WACCM). We find 68 ES events in 212 winters. These events are found in winters when the middle atmosphere is disturbed and there are zonal wind reversals in the stratosphere at high latitudes. These disturbances can be associated with both major and minor stratospheric sudden warming events (SSWs). The ES events occur under conditions where the stratospheric jet, the gravity wave forcing, and the residual circulation remain reversed longer than in those winters where an SSW occurs without an ES. We compare ES events with the type of SSW (vortex splitting and vortex displacement) and find that 68% of ES events form after vortex splitting events. We also present a climatology of ES events based on NASA's Modern‐Era Retrospective Analysis for Research and Applications reanalysis data from 1979 to 2012 and compare it to the model results. WACCM composites of major SSW and ES also show enhanced Eliassen‐Palm flux divergences in the upper mesosphere after the stratospheric warming, immediately before the formation of an ES. However, the formation of an ES in WACCM is due primarily to adiabatic heating from gravity wave‐driven downwelling, which follows the reestablishment of the eastward jet in the upper stratosphere. We find nine winters where an ES forms in the absence of any significant planetary wave activity in the upper mesosphere and illustrate one such event.