bluuebunny/crossref_metadata_2025 huggingface dataset:
Pippard Relations Close to the Melting Point in the Premelting Region of Hexadecane
Authors: Yurtseven Hamit , Tilki Özcan , Kurt Mustafa
Published: November 2012

We examine here the validity of the Pippard relations close to the melting point in the premelting region of hexadecane. For this verification, we analyze the observed data for the thermal expansivity
obtained for various pressures at constant temperatures of 302 and 325 K in this system. By calculating the isothermal compressibility and the specific heat in the same pressure region of the premelting region of hexadecane, we obtain that varies linearly with and also that varies linearly with for this system. This indicat es that some molecular organic compounds, such as solid hexadecane studied here, can exhibit -phase transitions prior to melting which are expected to verify the Pippard relations.
Photonic Technologies for Millimeter- and Submillimeter-Wave Signals
Authors: Vidal B. , Nagatsuma T. , Gomes N. J. , Darcie T. E.
Published: November 2012

Fiber optic components offer a competitive implementation for applications exploiting the millimeter-wave and THz regimes due to their capability for implementing broadband, compact, and cost-effective systems. In this paper, an outline of the latest technology developments and applications of fiber-optic-based technologies for the generation, transmission, and processing of high-frequency radio signals is provided.
Genes Regulated in Metastatic Osteosarcoma: Evaluation by Microarray Analysis in Four Human and Two Mouse Cell Line Systems
Authors: Muff Roman , Ram Kumar Ram Mohan , Botter Sander M. , Born Walter , Fuchs Bruno
Published: November 2012

Osteosarcoma (OS) is a rare bone neoplasm that affects mainly adolescents. It is associated with poor prognosis in case of metastases formation. The search for metastasis predicting markers is therefore imperative to optimize treatment strategies for patients at risk and important for the search of new drugs for the treatment of this devastating disease. Here, we have analyzed by microarray the differential gene expression in four human and two mouse OS cell line systems consisting of parental cell lines with low metastatic potential and derivatives thereof with increased metastatic potential. Using two osteoblastic cell line systems, the most common OS phenotype, we have identified forty-eight common genes that are differentially expressed in metastatic cell lines compared to parental cells. The identified subset of metastasis relevant genes in osteoblastic OS overlapped only minimally with differentially expressed genes in the other four preosteoblast or nonosteoblastic cell line systems. The results imply an OS phenotype specific expression pattern of metastasis regulating proteins and form a basis for further investigation of gene expression profiles in patients’ samples combined with survival analysis with the aim to optimize treatment strategies to develop new drugs and to consequently improve the survival of patients with the most common form of osteoblastic OS.
Effects of the Yangjing Capsule Extract on Steroidogenesis and Apoptosis in Mouse Leydig Cells
Authors: Sun Dalin , Cui Yugui , Jin Baofang , Zhang Xindong , Yang Xiaoyu , Gao Chao
Published: November 2012

Objectives. This study aimed to explore the effect and mechanism of Yangjing capsule on testosterone secretion in mouse Leydig tumor cells (MLTC-1).Methods. MLTC-1 cells were treated with the Yangjing capsule extract for 24 h. The testosterone level in medium was measured by radioimmunoassay. The expression of steroidogenic enzymes (StAR, CYP11A1, and HSD3B) in the cells was examined using real-time RT-PCR and immunoblotting. Additionally, MLTC-1 cells were treated for 48 h in a serum-free medium. The cell viability was measured by MTT assay. The cell cycle and apoptosis were analyzed using flow cytometry. The expression of activated caspase-3 was analyzed using RT-PCR and a colorimetric protease assay.Results. The Yangjing capsule extract increased testosterone production and the expression of StAR, CYP11A1, and HSD3B mRNAs and proteins compared with the control. H89 significantly inhibited these effects. The medicine improved the viability of MLTC-1 cells, decreased the number of cells in G0/G1 phase, and increased the number of cells in S-phase, as well as prevented cell apoptosis by inhibiting caspase-3.Conclusion. The Yangjing capsule can stimulate MLTC-1 cells to secrete testosterone and may be an alternative treatment for diseases characterized by insufficient testosterone production.
Short- and Medium-Term Induced Ionization in the Earth Atmosphere by Galactic and Solar Cosmic Rays
Authors: Mishev Alexander
Published: November 2012

The galactic cosmic rays are the main source of ionization in the troposphere of the Earth. Solar energetic particles of MeV energies cause an excess of ionization in the atmosphere, specifically over polar caps. The ionization effect during the major ground level enhancement 69 on January 20, 2005 is studied at various time scales. The estimation of ion rate is based on a recent numerical model for cosmic-ray-induced ionization. The ionization effect in the Earth atmosphere is obtained on the basis of solar proton energy spectra, reconstructed from GOES 11 measurements and subsequent full Monte Carlo simulation of cosmic-ray-induced atmospheric cascade. The evolution of atmospheric cascade is performed with CORSIKA 6.990 code using FLUKA 2011 and QGSJET II hadron interaction models. The atmospheric ion rate is explicitly obtained for various latitudes, namely, 40°N, 60°N and 80°N. The time evolution of obtained ion rates is presented. The short- and medium-term ionization effect is compared with the average effect due to galactic cosmic rays. It is demonstrated that ionization effect is significant only in subpolar and polar atmosphere during the major ground level enhancement of January 20, 2005. It is negative in troposphere at midlatitude, because of the accompanying Forbush effect.
Study of Fluoride Affinity by Zirconium Impregnated Walnut Shell Carbon in Aqueous Phase: Kinetic and Isotherm Evaluation
Authors: Rajan M. , Alagumuthu G.
Published: November 2012

This paper examines the kinetics of fluoride removal from water by the adsorbent zirconium‐impregnated walnut‐shell carbon (ZIWSC), exploring the mechanisms involved. The dependence of the adsorption of fluoride on the pH of the solution has been studied to achieve the optimum pH value and a better understanding of the adsorption mechanism. The presence of bicarbonate ions in aqueous solution was found to affect the fluoride removal indicating that these anions compete with the sorption of fluoride on adsorbents. The kinetic profile has been modeled using pseudo‐first‐order model, pseudo‐second‐order model, and intraparticle diffusion model. The kinetic sorption profiles offered excellent fit with pseudo‐second‐order model. Adsorption isotherms have been modeled by Langmuir, Freundlich, and Temkin equations, and their constants were determined. The equilibrium adsorption data were fitted reasonably well for Freundlich isotherm model. XRD and SEM patterns of the ZIWSC were recorded to get better insight into the mechanism of adsorption process.
Oxidation of Chalcones by Morpholinium Chlorochromate with Oxalic Acid as Catalyst: Kinetic and Mechanistic Study
Authors: Rajalakshmi K. , Ramachandramoorthy T.
Published: November 2012

The kinetics of oxidation of chalcones by morpholinium chlorochromate (MCC) has been studied in 55% acetic acid‐water (v/v) medium. The reaction showed unit order dependence each with respect to oxidant and catalyst and fractional order with respect to substrate and H+ ion. Increased ionic strength has no effect on the reaction rate. In the case of substituted chalcones, the order with respect to substrate varies depending upon the nature of the substituent present in the ring. In general, the electron withdrawing substituents retard the reaction rate while the electron releasing substituents enhance the rate of the reaction. From the kinetic data obtained, the activation parameters have been calculated and a suitable mechanism has been proposed.
Sublimation Kinetic Studies of the Zr(tmhd) 4 Complex
Authors: Arul Jeevan T. S. , Nagaraja K. S.
Published: November 2012

The thermal behaviour of tetrakis(2,2,6,6‐tetramethyl‐3,5‐heptanedionato)zirconium(IV), [Zr(tmhd)4] was investigated by nonisothermal and isothermal thermogravimetric methods in a high pure nitrogen atmosphere. The influence of the heating rate in dynamic measurements (6, 8, 10, and 12°C/min) on activation energy was also studied. The nonisothermal sublimation activation energy values determined following the procedures of Arrhenius, Coats and Redfern, Kissinger, and Flynn‐Wall yielded 76 ± 5, 92 ± 2, 81 ± 8, and 72 ± 7 kJ/mol, respectively, and the isothermal sublimation activation energy was found to be 87 ± 4 kJ/mol over the temperature range of 411–462 K. Different reaction mechanisms were used to compare with this value. Analysis of the experimental results suggested that the actual reaction mechanism was an Rn deceleration type.
Vaccination with Irradiated Tumor Cells Pulsed with an Adjuvant That Stimulates NKT Cells Is an Effective Treatment for Glioma
Authors: Hunn Martin K. , Farrand Kathryn J. , Broadley Kate W.R. , Weinkove Robert , Ferguson Peter , Miller Rose J. , Field Cameron S. , Petersen Troels , McConnell Melanie J. , Hermans Ian F.
Published: November 2012

Purpose: The prognosis for patients with glioblastoma multiforme (GBM) remains extremely poor despite recent treatment advances. There is an urgent need to develop novel therapies for this disease.

Experimental Design: We used the implantable GL261 murine glioma model to investigate the therapeutic potential of a vaccine consisting of intravenous injection of irradiated whole tumor cells pulsed with the immuno-adjuvant α-galactosylceramide (α-GalCer).

Results: Vaccine treatment alone was highly effective in a prophylactic setting. In a more stringent therapeutic setting, administration of one dose of vaccine combined with depletion of regulatory T cells (Treg) resulted in 43% long-term survival and the disappearance of mass lesions detected by MRI. Mechanistically, the α-GalCer component was shown to act by stimulating “invariant” natural killer–like T cells (iNKT cells) in a CD1d-restricted manner, which in turn supported the development of a CD4+ T-cell–mediated adaptive immune response. Pulsing α-GalCer onto tumor cells avoided the profound iNKT cell anergy induced by free α-GalCer. To investigate the potential for clinical application of this vaccine, the number and function of iNKT cells was assessed in patients with GBM and shown to be similar to age-matched healthy volunteers. Furthermore, irradiated GBM tumor cells pulsed with α-GalCer were able to stimulate iNKT cells and augment a T-cell response in vitro.

Conclusions: Injection of irradiated tumor cells loaded with α-GalCer is a simple procedure that could provide effective immunotherapy for patients with high-grade glioma. Clin Cancer Res; 18(23); 6446–59. ©2012 AACR.
Endoglin (CD105) Contributes to Platinum Resistance and Is A Target for Tumor-Specific Therapy in Epithelial Ovarian Cancer
Authors: Ziebarth Angela J. , Nowsheen Somaira , Steg Adam D. , Shah Monjri M. , Katre Ashwini A. , Dobbin Zachary C. , Han Hee-Dong , Lopez-Berestein Gabriel , Sood Anil K. , Conner Michael , Yang Eddy S. , Landen Charles N.
Published: November 2012

Purpose: Endoglin (CD105) is a membranous protein overexpressed in tumor-associated endothelial cells, chemoresistant populations of ovarian cancer cells, and potentially stem cells. Our objective was to evaluate the effects and mechanisms of targeting endoglin in ovarian cancer.

Experimental Design: Global and membranous endoglin expression was evaluated in multiple ovarian cancer lines. In vitro, the effects of siRNA-mediated endoglin knockdown with and without chemotherapy were evaluated by MTT assay, cell-cycle analysis, alkaline comet assay, γ-H2AX foci formation, and quantitative PCR. In an orthotopic mouse model, endoglin was targeted with chitosan-encapsulated siRNA with and without carboplatin.

Results: Endoglin expression was surprisingly predominantly cytoplasmic, with a small population of surface-positive cells. Endoglin inhibition decreased cell viability, increased apoptosis, induced double-stranded DNA damage, and increased cisplatin sensitivity. Targeting endoglin downregulates expression of numerous DNA repair genes, including BARD1, H2AFX, NBN, NTHL1, and SIRT1. BARD1 was also associated with platinum resistance, and was induced by platinum exposure. In vivo, antiendoglin treatment decreased tumor weight in both ES2 and HeyA8MDR models when compared with control (35%–41% reduction, P < 0.05). Endoglin inhibition with carboplatin was associated with even greater inhibitory effect when compared with control (58%–62% reduction, P < 0.001).

Conclusions: Endoglin downregulation promotes apoptosis, induces significant DNA damage through modulation of numerous DNA repair genes, and improves platinum sensitivity both in vivo and in vitro. Antiendoglin therapy would allow dual treatment of both tumor angiogenesis and a subset of aggressive tumor cells expressing endoglin and is being actively pursued as therapy in ovarian cancer. Clin Cancer Res; 19(1); 170–82. ©2012 AACR.
The Severity of Neural Invasion Is Associated with Shortened Survival in Colon Cancer
Authors: Liebl Florian , Demir Ihsan Ekin , Rosenberg Robert , Boldis Alexandra , Yildiz Esra , Kujundzic Kristina , Kehl Timo , Dischl Dominic , Schuster Tibor , Maak Matthias , Becker Karen , Langer Rupert , Laschinger Melanie , Friess Helmut , Ceyhan Güralp O.
Published: November 2012

Purpose: Neural invasion (NI) is a histopathologic feature of colon cancer that receives little consideration. Therefore, we conducted a morphologic and functional characterization of NI in colon cancer.

Experimental Design: NI was investigated in 673 patients with colon cancer. Localization and severity of NI was determined and related to patient's prognosis and survival. The neuro-affinity of colon cancer cells (HT29, HCT-116, SW620, and DLD-1) was compared with pancreatic cancer (T3M4 and SU86.86) and rectal cancer cells (CMT-93) in the in vitro three-dimensional (3D)–neural-migration assay and analyzed via live-cell imaging. Immunoreactivity of the neuroplasticity marker GAP-43, and the neurotrophic-chemoattractant factors Artemin and nerve growth factor (NGF), was quantified in colon cancer and pancreatic cancer nerves. Dorsal root ganglia of newborn rats were exposed to supernatants of colon cancer, rectal cancer, and pancreatic cancer cells and neurite density was determined.

Results: NI was detected in 210 of 673 patients (31.2%). Although increasing NI severity scores were associated with a significantly poorer survival, presence of NI was not an independent prognostic factor in colon cancer. In the 3D migration assay, colon cancer and rectal cancer cells showed much less neurite-targeted migration when compared with pancreatic cancer cells. Supernatants of pancreatic cancer and rectal cancer cells induced a much higher neurite density than those of colon cancer cells. Accordingly, NGF, Artemin, and GAP-43 were much more pronounced in nerves in pancreatic cancer than in colon cancer.

Conclusion: NI is not an independent prognostic factor in colon cancer. The lack of a considerable biologic affinity between colon cancer cells and neurons, the low expression profile of colonic nerves for chemoattractant molecules, and the absence of a major neuroplasticity in colon cancer may explain the low prevalence and impact of NI in colon cancer. Clin Cancer Res; 19(1); 50–61. ©2012 AACR.
Parsing Morphologically Rich Languages: Introduction to the Special Issue
Authors: Tsarfaty Reut , Seddah Djamé , Kübler Sandra , Nivre Joakim
Published: November 2012

Parsing is a key task in natural language processing. It involves predicting, for each natural language sentence, an abstract representation of the grammatical entities in the sentence and the relations between these entities. This representation provides an interface to compositional semantics and to the notions of “who did what to whom.” The last two decades have seen great advances in parsing English, leading to major leaps also in the performance of applications that use parsers as part of their backbone, such as systems for information extraction, sentiment analysis, text summarization, and machine translation. Attempts to replicate the success of parsing English for other languages have often yielded unsatisfactory results. In particular, parsing languages with complex word structure and flexible word order has been shown to require non-trivial adaptation. This special issue reports on methods that successfully address the challenges involved in parsing a range of morphologically rich languages (MRLs). This introduction characterizes MRLs, describes the challenges in parsing MRLs, and outlines the contributions of the articles in the special issue. These contributions present up-to-date research efforts that address parsing in varied, cross-lingual settings. They show that parsing MRLs addresses challenges that transcend particular representational and algorithmic choices.
Knowledge Sources for Constituent Parsing of German, a Morphologically Rich and Less-Configurational Language
Authors: Fraser Alexander , Schmid Helmut , Farkas Richárd , Wang Renjing , Schütze Hinrich
Published: November 2012

We study constituent parsing of German, a morphologically rich and less-configurational language. We use a probabilistic context-free grammar treebank grammar that has been adapted to the morphologically rich properties of German by markovization and special features added to its productions. We evaluate the impact of adding lexical knowledge. Then we examine both monolingual and bilingual approaches to parse reranking. Our reranking parser is the new state of the art in constituency parsing of the TIGER Treebank. We perform an analysis, concluding with lessons learned, which apply to parsing other morphologically rich and less-configurational languages.
Word Segmentation, Unknown-word Resolution, and Morphological Agreement in a Hebrew Parsing System
Authors: Goldberg Yoav , Elhadad Michael
Published: November 2012

We present a constituency parsing system for Modern Hebrew. The system is based on the PCFG-LA parsing method of Petrov et al. 2006 , which is extended in various ways in order to accommodate the specificities of Hebrew as a morphologically rich language with a small treebank. We show that parsing performance can be enhanced by utilizing a language resource external to the treebank, specifically, a lexicon-based morphological analyzer. We present a computational model of interfacing the external lexicon and a treebank-based parser, also in the common case where the lexicon and the treebank follow different annotation schemes. We show that Hebrew word-segmentation and constituency-parsing can be performed jointly using CKY lattice parsing. Performing the tasks jointly is effective, and substantially outperforms a pipeline-based model. We suggest modeling grammatical agreement in a constituency-based parser as a filter mechanism that is orthogonal to the grammar, and present a concrete implementation of the method. Although the constituency parser does not make many agreement mistakes to begin with, the filter mechanism is effective in fixing the agreement mistakes that the parser does make.

These contributions extend outside of the scope of Hebrew processing, and are of general applicability to the NLP community. Hebrew is a specific case of a morphologically rich language, and ideas presented in this work are useful also for processing other languages, including English. The lattice-based parsing methodology is useful in any case where the input is uncertain. Extending the lexical coverage of a treebank-derived parser using an external lexicon is relevant for any language with a small treebank.
Dependency Parsing of Modern Standard Arabic with Lexical and Inflectional Features
Authors: Marton Yuval , Habash Nizar , Rambow Owen
Published: November 2012

We explore the contribution of lexical and inflectional morphology features to dependency parsing of Arabic, a morphologically rich language with complex agreement patterns. Using controlled experiments, we contrast the contribution of different part-of-speech (POS) tag sets and morphological features in two input conditions: machine-predicted condition (in which POS tags and morphological feature values are automatically assigned), and gold condition (in which their true values are known). We find that more informative (fine-grained) tag sets are useful in the gold condition, but may be detrimental in the predicted condition, where they are outperformed by simpler but more accurately predicted tag sets. We identify a set of features (definiteness, person, number, gender, and undiacritized lemma) that improve parsing quality in the predicted condition, whereas other features are more useful in gold. We are the first to show that functional features for gender and number (e.g., “broken plurals”), and optionally the related rationality (“humanness”) feature, are more helpful for parsing than form-based gender and number. We finally show that parsing quality in the predicted condition can dramatically improve by training in a combined gold+predicted condition. We experimented with two transition-based parsers, MaltParser and Easy-First Parser. Our findings are robust across parsers, models, and input conditions. This suggests that the contribution of the linguistic knowledge in the tag sets and features we identified goes beyond particular experimental settings, and may be informative for other parsers and morphologically rich languages.
The Layered Structure of the Winter Atmospheric Boundary Layer in the Interior of Alaska
Authors: Mayfield John A. , Fochesatto Gilberto J.
Published: November 2012

The high-latitude winter atmospheric boundary layer of interior Alaska continually exhibits a complex layered structure as a result of extreme meteorological conditions. In this paper the occurrence of elevated inversions (EI), surface-based inversions (SBI), and stratified layers in the sub-Arctic from January 2000 to December 2009 is reported. This statistical analysis is based on radiosonde observation data from the Fairbanks National Weather Service station complemented by Winter Boundary Layer Experiment observations in the period 2010–11. This study found that SBIs occurred 64% of the time. An SBI occurred in combination with one, two, three, or four simultaneous EIs 84.86%, 48.49%, 21.23%, and 7.99% of the time, respectively, in 2326 total cases. The calculated mean SBI height was 377 m; EIs occurred at 1231, 2125, 2720, and 3125 m, respectively. This analysis was able to discriminate between locally controlled inversion layers and synoptic-dependent inversions and to identify their formation mechanisms. It was found that, in the presence of an SBI layer, the first EI layer formed 35.8% of the time under anticyclonic conditions at a mean height of 1249 m and 22% of the time in warm-air-advection situations at a mean height of 1049 m. The remaining 23.4% resulted from combined synoptic situations, and 18.8% were unclassified.
The Generation of Turbulence below Midlevel Cloud Bases: The Effect of Cooling due to Sublimation of Snow
Authors: Kudo Atsushi
Published: November 2012

In the author’s experience as a forecaster, commercial aircraft sometimes report turbulence beneath midlevel clouds that extend above upper frontal zones. Turbulence caused by Kelvin–Helmholtz instability occurs in upper frontal zones with strong vertical shear of horizontal winds. However, the turbulence seems to occur not only in the cloud bases (where upper frontal zones are) but also below the cloud bases where the vertical shear is not strong. Because those clouds are usually accompanied by precipitation that does not reach the ground, cooling by evaporation or sublimation seems to contribute to the generation of turbulence. In this paper, the mechanisms generating turbulence below midlevel cloud bases are examined by using observations and high-resolution three-dimensional numerical simulations with idealized initial conditions. The numerical simulations showed that the following sequence of events led to turbulence. Falling snow sublimated below cloud bases and cooled the air, which created absolute instability. This generated Rayleigh–Bénard convection cells. The vertical motion caused turbulence. The horizontal scale of the convection was about 800–1000 m, and the variations of vertical wind velocity were up to about 7 m s−1. The cloud base was accompanied by a virga-like distribution of snow. Sensitivity experiments showed the appropriate conditions to cause the turbulence: 1) the cloud-base temperature was between about 0° and −15°C, 2) the relative humidity in subcloud layers was sufficiently low, and 3) the stability in subcloud layers was weak. The results of the numerical simulations agreed well with the observations.
Observational Analysis of Tropical Cyclone Formation Associated with Monsoon Gyres
Authors: Wu Liguang , Zong Huijun , Liang Jia
Published: November 2012

Large-scale monsoon gyres and the involved tropical cyclone formation over the western North Pacific have been documented in previous studies. The aim of this study is to understand how monsoon gyres affect tropical cyclone formation. An observational study is conducted on monsoon gyres during the period 2000–10, with a focus on their structures and the associated tropical cyclone formation.

A total of 37 monsoon gyres are identified in May–October during 2000–10, among which 31 monsoon gyres are accompanied with the formation of 42 tropical cyclones, accounting for 19.8% of the total tropical cyclone formation. Monsoon gyres are generally located on the poleward side of the composited monsoon trough with a peak occurrence in August–October. Extending about 1000 km outward from the center at lower levels, the cyclonic circulation of the composited monsoon gyre shrinks with height and is replaced with negative relative vorticity above 200 hPa. The maximum winds of the composited monsoon gyre appear 500–800 km away from the gyre center with a magnitude of 6–10 m s−1 at 850 hPa. In agreement with previous studies, the composited monsoon gyre shows enhanced southwesterly flow and convection on the south-southeastern side. Most of the tropical cyclones associated with monsoon gyres are found to form near the centers of monsoon gyres and the northeastern end of the enhanced southwesterly flows, accompanying relatively weak vertical wind shear.
The Effects of Explicit versus Parameterized Convection on the MJO in a Large-Domain High-Resolution Tropical Case Study. Part I: Characterization of Large-Scale Organization and Propagation*
Authors: Holloway Christopher E. , Woolnough Steven J. , Lister Grenville M. S.
Published: November 2012

High-resolution simulations over a large tropical domain (~20°S–20°N, 42°E–180°) using both explicit and parameterized convection are analyzed and compared to observations during a 10-day case study of an active Madden–Julian oscillation (MJO) event. The parameterized convection model simulations at both 40- and 12-km grid spacing have a very weak MJO signal and little eastward propagation. A 4-km explicit convection simulation using Smagorinsky subgrid mixing in the vertical and horizontal dimensions exhibits the best MJO strength and propagation speed. Explicit convection simulations at 12 km also perform much better than the 12-km parameterized convection run, suggesting that the convection scheme, rather than horizontal resolution, is key for these MJO simulations. Interestingly, a 4-km explicit convection simulation using the conventional boundary layer scheme for vertical subgrid mixing (but still using Smagorinsky horizontal mixing) completely loses the large-scale MJO organization, showing that relatively high resolution with explicit convection does not guarantee a good MJO simulation. Models with a good MJO representation have a more realistic relationship between lower-free-tropospheric moisture and precipitation, supporting the idea that the moisture–convection feedback is a key process for MJO propagation. There is also increased generation of available potential energy and conversion of that energy into kinetic energy in models with a more realistic MJO, which is related to larger zonal variance in convective heating and vertical velocity, larger zonal temperature variance around 200 hPa, and larger correlations between temperature and ascent (and between temperature and diabatic heating) between 500 and 400 hPa.
Upper Oceanic Energy Response to Tropical Cyclone Passage
Authors: Knaff John A. , DeMaria Mark , Sampson Charles R. , Peak James E. , Cummings James , Schubert Wayne H.
Published: November 2012

The upper oceanic temporal response to tropical cyclone (TC) passage is investigated using a 6-yr daily record of data-driven analyses of two measures of upper ocean energy content based on the U.S. Navy’s Coupled Ocean Data Assimilation System and TC best-track records. Composite analyses of these data at points along the TC track are used to investigate the type, magnitude, and persistence of upper ocean response to TC passage, and to infer relationships between routinely available TC information and the upper ocean response. Upper oceanic energy decreases in these metrics are shown to persist for at least 30 days—long enough to possibly affect future TCs. Results also indicate that TC kinetic energy (KE) should be considered when assessing TC impacts on the upper ocean, and that existing TC best-track structure information, which is used here to estimate KE, is sufficient for such endeavors. Analyses also lead to recommendations concerning metrics of upper ocean energy. Finally, parameterizations for the lagged, along-track, upper ocean response to TC passage are developed. These show that the sea surface temperature (SST) is best related to the KE and the latitude whereas the upper ocean energy is a function of KE, initial upper ocean energy conditions, and translation speed. These parameterizations imply that the 10-day lagged SST cooling is approximately 0.7°C for a “typical” TC at 30° latitude, whereas the same storm results in 10-day (30-day) lagged decreases of upper oceanic energy by about 12 (7) kJ cm−2 and a 0.5°C (0.3°C) cooling of the top 100 m of ocean.
The Impact of Oceanic Near-Inertial Waves on Climate
Authors: Jochum Markus , Briegleb Bruce P. , Danabasoglu Gokhan , Large William G. , Norton Nancy J. , Jayne Steven R. , Alford Matthew H. , Bryan Frank O.
Published: November 2012

The Community Climate System Model, version 4 (CCSM4) is used to assess the climate impact of wind-generated near-inertial waves (NIWs). Even with high-frequency coupling, CCSM4 underestimates the strength of NIWs, so that a parameterization for NIWs is developed and included into CCSM4. Numerous assumptions enter this parameterization, the core of which is that the NIW velocity signal is detected during the model integration, and amplified in the shear computation of the ocean surface boundary layer module. It is found that NIWs deepen the ocean mixed layer by up to 30%, but they contribute little to the ventilation and mixing of the ocean below the thermocline. However, the deepening of the tropical mixed layer by NIWs leads to a change in tropical sea surface temperature and precipitation. Atmospheric teleconnections then change the global sea level pressure fields so that the midlatitude westerlies become weaker. Unfortunately, the magnitude of the real air-sea flux of NIW energy is poorly constrained by observations; this makes the quantitative assessment of their climate impact rather uncertain. Thus, a major result of the present study is that because of its importance for global climate the uncertainty in the observed tropical NIW energy has to be reduced.
A Comparison of Methods for Filling Gaps in Hourly Near-Surface Air Temperature Data
Authors: Henn Brian , Raleigh Mark S. , Fisher Alex , Lundquist Jessica D.
Published: November 2012

Near-surface air temperature observations often have periods of missing data, and many applications using these datasets require filling in all missing periods. Multiple methods are available to fill missing data, but the comparative accuracy of these approaches has not been assessed. In this comparative study, five techniques were used to fill in missing temperature data: spatiotemporal correlations in the form of empirical orthogonal functions (EOFs), time series diurnal interpolation, and three variations of lapse rate–based filling. The method validation used sets of hourly surface temperature observations in complex terrain from five regions. The most accurate method for filling missing data depended on the number of available stations and the number of hours of missing data. Spatiotemporal correlations using EOF reconstruction were most accurate provided that at least 16 stations were available. Temporal interpolation was the most accurate method when only one or two stations were available or for 1-h gaps. Lapse rate–based filling was most accurate for intermediate numbers of stations. The accuracy of the lapse rate and EOF methods was found to be sensitive to the vertical separation of stations and the degree of correlation between them, which also explained some of the regional differences in performance. Horizontal distance was less significantly correlated with method performance. From these findings, guidelines are presented for choosing a filling method based on the duration of the missing data and the number of stations.
A Surface-Aware Projection Basis for Quasigeostrophic Flow
Authors: Smith K. Shafer , Vanneste Jacques
Published: November 2012

Recent studies indicate that altimetric observations of the ocean’s mesoscale eddy field reflect the combined influence of surface buoyancy and interior potential vorticity anomalies. The former have a surface-trapped structure, while the latter are often well represented by the barotropic and first baroclinic modes. To assess the relative importance of each contribution to the signal, it is useful to project the observed field onto a set of modes that separates their influence in a natural way. However, the surface-trapped dynamics are not well represented by standard baroclinic modes; moreover, they are dependent on horizontal scale.

Here the authors derive a modal decomposition that results from the simultaneous diagonalization of the energy and a generalization of potential enstrophy that includes contributions from the surface buoyancy fields. This approach yields a family of orthonormal bases that depend on two parameters; the standard baroclinic modes are recovered in a limiting case, while other choices provide modes that represent surface and interior dynamics in an efficient way.

For constant stratification, these modes consist of symmetric and antisymmetric exponential modes that capture the surface dynamics and a series of oscillating modes that represent the interior dynamics. Motivated by the ocean, where shears are concentrated near the upper surface, the authors consider the special case of a quiescent lower surface. In this case, the interior modes are independent of wavenumber, and there is a single exponential surface mode that replaces the barotropic mode. The use and effectiveness of these modes is demonstrated by projecting the energy in a set of simulations of baroclinic turbulence.
Eddy Saturation of Equilibrated Circumpolar Currents
Authors: Munday David R. , Johnson Helen L. , Marshall David P.
Published: November 2012

This study uses a sector configuration of an ocean general circulation model to examine the sensitivity of circumpolar transport and meridional overturning to changes in Southern Ocean wind stress and global diapycnal mixing. At eddy-permitting, and finer, resolution, the sensitivity of circumpolar transport to forcing magnitude is drastically reduced. At sufficiently high resolution, there is little or no sensitivity of circumpolar transport to wind stress, even in the limit of no wind. In contrast, the meridional overturning circulation continues to vary with Southern Ocean wind stress, but with reduced sensitivity in the limit of high wind stress. Both the circumpolar transport and meridional overturning continue to vary with diapycnal diffusivity at all model resolutions. The circumpolar transport becomes less sensitive to changes in diapycnal diffusivity at higher resolution, although sensitivity always remains. In contrast, the overturning circulation is more sensitive to change in diapycnal diffusivity when the resolution is high enough to permit mesoscale eddies.
Divorce and Women’s Risk of Health Insurance Loss
Authors: Lavelle Bridget , Smock Pamela J.
Published: November 2012

This article bridges the literatures on the economic consequences of divorce for women with that on marital transitions and health by focusing on women’s health insurance. Using a monthly calendar of marital status and health insurance coverage from 1,442 women in the Survey of Income and Program Participation, we examine how women’s health insurance changes after divorce. Our estimates suggest that roughly 115,000 American women lose private health insurance annually in the months following divorce and that roughly 65,000 of these women become uninsured. The loss of insurance coverage we observe is not just a short-term disruption. Women’s rates of insurance coverage remain depressed for more than two years after divorce. Insurance loss may compound the economic losses women experience after divorce and contribute to as well as compound previously documented health declines following divorce.
A new critical path method and a memetic algorithm for flexible job shop scheduling with overlapping operations
Authors: Farughi Hiwa , Yousefi Yegane Babak , Fathian Mohammad
Published: November 2012

The flexible job shop scheduling problem (FJSP) is an extension of the classical job shop scheduling problem (JSP) which allows an operation to be processed by any machine from a given set of machines. FJSP is NP-hard and presents two major difficulties. The first is to assign each operation to a machine out of a set of capable machines; and the second deals with sequencing the assigned operations on the machines. However, it is quite difficult to obtain an optimal solution to this problem in medium and large size problems with traditional optimization approaches. In this paper, a memetic algorithm (MA) for flexible job shop scheduling with overlapping operations is proposed that solves the FJSP to minimize makespan. We also proposed a heuristic that uses the critical path method (CPM) in order to improve the results of MA and reduce the objective function. The experimental results of MA and CPM show that our approach is capable of achieving the optimal solution for small size problems and near-optimal solutions for medium and large size problems in a reasonable time.
Using simulation to analyze the maintenance architecture for a USAF weapon system
Authors: Garza Ricardo , Hill Raymond R , Mattioda Daniel D
Published: November 2012

The United States Air Force (USAF) is investigating the use of three levels of repair with its aircraft maintenance managerial structure. This study provides an initial look at the effect of maintenance resource collaboration among maintenance locations and the use of a centralized repair facility focusing on a critical line replacement unit for a major USAF weapon system. Maintenance data for prior year maintenance experiences are collected, fit into appropriate probability distributions and implemented in a discrete event simulation model. This model is then used within an experimental design framework to examine the potential impact of organizational changes to the USAF hierarchical maintenance structure.
Ophthalmoplegic migraine: Migraine or oculomotor neuropathy?
Authors: Margari Lucia , Legrottaglie Anna R , Craig Francesco , Petruzzelli Maria G , Procoli Ugo , Dicuonzo Franca
Published: November 2012

Background

Ophthalmoplegic migraine (OM) is a rare condition characterized by the association of headaches and an oculomotor nerve palsy. The third cranial nerve is commonly involved in recurrent attacks, whereas involvement of the sixth and fourth nerves is uncommon. It is still debated whether an uncontrolled migraine or an oculomotor neuropathy may be the primary cause of ophthalmoplegic migraine.

Cases

We report two patients affected by OM with normal magnetic resonance imaging findings and a history of uncontrolled migraine before an attack of OM.

Conclusion

The cases reported allow us to hypothesize that OM may be considered a form of migraine rather than a cranial neuralgia. It is possible that different factors such as inflammatory or structural factors, may represent a vulnerability of the nerve during a severe migraine attack causing ophthalmoplegia.
Migraine is not associated with enhanced atherosclerosis
Authors: Stam Anine H , Weller Claudia M , Janssens A Cecile JW , Aulchenko Yurii S , Oostra Ben A , Frants Rune R , van den Maagdenberg Arn MJM , Ferrari Michel D , van Duijn Cornelia M , Terwindt Gisela M
Published: November 2012

Aim

Migraine, in particular with aura, has been associated with an increased risk for ischemic stroke and coronary heart disease. The underlying mechanism is unknown. In a cross-sectional case control study we investigated whether an enhanced risk of atherosclerosis in migraineurs explains this increased cardiovascular risk.

Methods

Subjects were participants from the population-based Erasmus Rucphen Family study. Atherosclerosis was assessed in 360 migraineurs (209 without aura and 151 with aura) and 617 subjects without migraine or severe headache. Atherosclerosis was quantified by intima media thickness, pulse wave velocity and ankle-brachial index.

Results

Migraineurs, especially with aura, were found more likely to smoke, have diabetes or a modestly decreased HDL-cholesterol. No differences were found for the atherosclerosis parameters.

Conclusion

In this large population-based study, migraineurs have no increased risk of atherosclerosis. Therefore, enhanced atherosclerosis is an unlikely explanation for the increased cardiovascular risk seen in migraineurs.
Keeping It Real in the Global South: Hip-Hop Comes to Sri Lanka
Authors: Saucier P. Khalil , Silva Kumarini
Published: November 2012

This article attempts to understand how hip-hop, as a uniquely black American articulation of marginalization and resistance, becomes a complex symbol of global belonging and post-colonial resistance in Sri Lanka. Sri Lankan hip-hop artists have established distinctive rap cultures, borrowing from their own local culture, as well as from US hip hop cultural practices in general. From more locally popular hip hop artists like Krishan, to internationally renowned M.I.A., these artists perform complex identities that symbolically centralize their ethnic identity, while simultaneously reproducing images of war, conflict and cultural displacement that articulate Sri Lanka’s complex relationship with the British empire, an ‘Americanized’ globalization, and a nationalist post-colonial identity.
Reflections on regression towards the mean
Authors: Tweney Ryan D.
Published: November 2012

In a recent article in this journal, Maraun, Gabriel, and Martin (2011) critically discuss the received views of the phenomenon of regression towards the mean, proposing changes in the way it should be viewed. Using in part Galton’s original data for the relation between parental height and child height, the present paper suggests that some undiscussed aspects of regression towards the mean are relevant. The usual methodological warnings given in the received view are not, in fact, entirely inappropriate.
Free vibration analysis of single- and double-walled carbon nanotubes based on nonlocal elastic shell models
Authors: Ansari Reza , Rouhi Hessam , Sahmani Saeid
Published: November 2012

In the present study, the free vibration characteristics of single- and double-walled carbon nanotubes (SWCNTs and DWCNTs) are investigated on the basis of a nonlocal elastic shell model. Eringen’s nonlocal elasticity equations are applied to the classical Donnell shell theory to incorporate the size-effects into the vibration analysis of carbon nanotubes (CNTs). An exact solution is developed for the governing equations of the nonlocal elastic shell model with the inclusion of size effects. Molecular dynamics (MD) simulations are performed to obtain fundamental frequencies of SWCNTs and DWCNTs with different values of aspect ratio and types of chirality. To derive the appropriate values of a nonlocal parameter for vibrations of SWCNTs and DWCNTs, the results of the continuum model are matched with those of MD simulations. This study shows that the small scale effects in the nonlocal model make nanotubes more flexible.
Nonlinear response with snap-through and fatigue life prediction for panels to thermo-acoustic loadings
Authors: Sha Yun Dong , Wei Jing , Gao Zhi Jun , Zhong Hao Jie
Published: November 2012

Thin-walled structures under thermo-acoustic loadings exhibit a complex nonlinear response which results in high cycle fatigue failure. The aim of the present paper is to analyze the influences of thermal-acoustic excitations on nonlinear dynamics response, and then give the corresponding multi-axial fatigue life estimation. The nonlinear responses of a clamped aluminum plate (2024-T3) under different thermal-acoustic loadings are firstly obtained, which include the response of the plate in pre/post buckled conditions and in snap-through conditions. Then the statistical properties with different temperatures and sound pressure levels are analyzed for further research on nonlinear response dynamics. Based on the thermo-acoustic response obtained, the rain flow matrix scheme is used to determine the distribution of fatigue cycles. Then the Miner accumulative damage model is employed to predict high cycle fatigue life, combined with a non-zero mean stress model. Results show that the fatigue life of a pre-buckled plate decreases with the increase of temperature. For a post-buckled plate, as the temperature increases, the fatigue life of the plate undergoing persistent snap-through keeps decreasing to the lowest point, and then increases after entering an intermittent snap-through regime.