bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of montmorillonite on the electron beam irradiated alumina trihydrate added polyethylene and ethylene vinyl acetate nanocomposite
Authors: Bee Soo‐Tueen , Hassan Azman , Ratnam Chantara T. , Tee Tiam‐Ting , Sin Lee Tin
Published: October 2012

This study aims at investigating the effects of montmorillonite (MMT) nanocomposite on the electron beam irradiated alumina trihydrate flame retardant added polyethylene and ethylene vinyl acetate blends (FRLE). The addition of MMT into FRLE blends has increased the limiting oxygen index (LOI%), which corresponds the improvement of flame resistivity, whereas increasing amount of MMT and irradiation dosage were found moderately influenced LOI% of the blends. However, incorporation of MMT has shown reinforcing effect to the FRLE, where the tensile strength for the samples subjected to 150 and 250 kGy irradiation have increased for 10.7 and 27%, respectively. In addition, increasing loading level of MMT and irradiation dosage caused inferior effects to the surface and volume resistivity of FRLE as high as four folds. This is due to the enhancement of transportability of MMT ionic in polymer matrix that caused the reduction of resistivity of FRLE. POLYM. COMPOS., 33:1883–1892, 2012. © 2012 Society of Plastics Engineers
Poly(ester‐amine) hyperbranched polymer as toughening and co‐curing agent for epoxy/clay nanocomposites
Authors: Eissa Mohamed M. , Youssef Moshera S.A. , Ramadan A.M. , Amin Amal
Published: October 2012

The marriage between hardness and flexibility of epoxy resins (improved toughness) is a desired feature, which broads their application in various industrial fields, especially for high impact resistance purposes. Accordingly, this work aims to improve toughness properties of epoxy resin (Epon‐828)/Ancamine (curing agent) system using amino‐terminated hyperbranched poly(ester‐amine) [Poly(PEODA‐NPA)] (HP) as toughening and/or co‐curing agent, in presence of organo‐modified Montmorillonite clay (OMMT) as a reinforcing filler. HP was synthesized via Michael addition reaction of poly(ethylene glycol) diacrylate (PEODA) to N‐methyl‐1,3‐propanediamine (NPA). Chemical structure and molecular weight of HP were elucidated using infrared (FTIR) spectroscopy and gel permeation chromatography (GPC) techniques, respectively. Epoxy/OMMT nanocomposites toughened with HP (at different concentrations) showed remarkable improvement in their toughness without any adverse effect on the other physico‐mechanical properties. The optimum concentration of HP and OMMT was found to be 20 wt % and 1–3 wt% of the epoxy resin, respectively. The extent of exfoliation and dispersion of OMMT platelets within the epoxy cured films was assessed by X‐ray diffraction (XRD) and transmission electron microscopy (TEM) measurements. In addition, thermal gravimetric analyses (TGA‐DTA) of epoxy/OMMT nanocomposites toughened with HP showed a slight increase in their decomposition temperature, particularly at low OMMT loading. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Upregulation of miR‐153 promotes cell proliferation via downregulation of the PTEN tumor suppressor gene in human prostate cancer
Authors: Wu Ziqing , He Benfu , He Jincan , Mao Xiangming
Published: October 2012

BACKGROUND

Accumulating evidence indicates that microRNAs play a pivotal role in the development and progression of prostate cancer. The present study was aimed at clarifying the biological functions of miR‐153, one of the upregulated microRNAs in prostate cancers, and the signaling transduction induced by miR‐153.

METHODS

miR‐153 was identified to be overexpressed in prostate cancers. The probable biological function of miR‐153 in cellular proliferation was then examined by diverse assays, such as MTT, colony formation and BrdUrd incorporation assay. Moreover, real‐time PCR and western blotting analysis were applied to investigate the underlying molecular mechanism induced by miR‐153. Luciferase assays were used to determined the FOXO1 transactivity and the direct regulation of PTEN‐3′‐UTR by miR‐153.

RESULTS

High‐throughput method identified miR‐153 to be upregulated in prostate cancers, which is further confirmed by the upregulated expression in four paired prostate tumor/adjacent non‐cancerous tissues from the same patients. Further studies revealed that overexpression of miR‐153 promoted cell cycle transition and cell proliferation, while inhibition of miR‐153 reduced this effect. Moreover, miR‐153 overexpression in prostate cancer cells increased the G1/S transitional promoter, cyclin D1 expression, and decreased cyclin‐dependent kinase (CDK) inhibitor, p21Cip1expression. In addition, we demonstrated that miR‐153 directly targeted the PTEN tumor suppressor gene, activated the AKT signaling and downregulated FOXO1 transcriptional activity.

CONCLUSIONS

Taken together, our results suggest that miR‐153 play an important role in promoting proliferation of human prostate cancer cells and present a novel mechanism of microRNA‐mediated direct suppression of PTEN expression in prostate cancer cells. Prostate 73: 596–604, 2013. © 2012 Wiley Periodicals, Inc.
Evaluation of Antifungal Activity of Antimicrobial Agents on Cheddar Cheese
Authors: Kuorwel Kuorwel K. , Cran Marlene J. , Sonneveld Kees , Miltz Joseph , Bigger Stephen W.
Published: October 2012

The antifungal activity against Aspergillus niger of the antimicrobial (AM) agents linalool, carvacrol and thymol incorporated in the coatings of starch‐based films was investigated. The activity was initially determined on a solid medium using the modified microatmosphere method and then examined on Cheddar cheese. On the solid media, all the AM films demonstrated a significant inhibitory effect against A. niger growth. The inhibitory effect of the AM films containing 2.38% (w/w) AM agents is reflected by the colony diameters that were 29.3, 25.4 and 21.3 mm for linalool, carvacrol and thymol, respectively, at 25°C after 7 days incubation compared with the control sample where the colony diameter was 85.3 mm. The AM films containing 2.38% (w/w) linalool, carvacrol or thymol reduced the population of A. niger on the surface of Cheddar cheese by 1.8, 2.0 and 2.2 log CFU/g, respectively, after 35 days of storage at 15°C. The results suggest that starch‐based film coated with an AM agent has the potential for being used as a fungicidal packaging system. Copyright © 2012 John Wiley & Sons, Ltd.
Multi‐Fuel Driven Janus Micromotors
Authors: Gao Wei , D'Agostino Mattia , Garcia‐Gradilla Victor , Orozco Jahir , Wang Joseph
Published: October 2012

Here the first example of a chemically powered micromotor that harvests its energy from the reactions of three different fuels is presented. The new Al/Pd Janus microspheres—prepared by depositing a Pd layer on one side of Al microparticles—are propelled efficiently by the thrust of hydrogen bubbles generated from different reactions of Al in strong acidic and alkaline environments, and by an oxygen bubble thrust produced at their partial Pd coating in hydrogen peroxide media. High speeds and long lifetimes of 200 μm s−1 and 8 min are achieved in strong alkaline media and acidic media, respectively. The ability to autonomously adapt to the presence of a new fuel (surrounding environment), without compromising the propulsion behavior is illustrated. These data also represent the first example of a chemically powered micromotor that propels autonomously and efficiently in alkaline environments (pH > 11) without additional fuels. The ability to use multiple fuel sources to power the same micromotor offers a broader scope of operation and considerable promise for diverse applications of micromotors in different chemical environments.
Practical dissonance: Bridging the gap between academia and agencies
Authors: Rupp Susan P.
Published: October 2012

Traditional natural resource programs in higher education tend to target biota, habitat, and human users and/or values as interacting components of a system. In the 2007 Journal of Wildlife Management article “Dinosaur Ramblings,” Scalet (2007) described a shifting continuum between applied or management‐oriented research and basic ecological research that continues to challenge how programs in higher education approach the training of young professionals. In a 2008 issue of the same journal, a seminar on this topic resulted in students publishing “Dinosaur Evolution: Student Response to Dinosaur Ramblings,” (Parker et al. ) in which they concurred that this continuum exists, but argued that change has been more an integration of applied and basic research as opposed to a shift away from management. The multiple‐use mission of many organizations today requires a more holistic approach to management. However, professionals often report that students lack the basic skills needed for applied management. I propose an alternative model, based on modern psychological principles, that redirects our focus toward the area of greatest concern—the apparent and increasing disconnect between what is taught to students in academic settings and what agencies expect from employees in practice, as both make the shift to more holistic management at different rates. The magnitude of this “practical dissonance” can be reduced by changing practices, adding consonant activities, or altering the perceived importance of those discrepancies to bring the trajectories more in line with each other. Change is inevitable in society, higher education, and natural resource management; our responsibility is to ensure that the link between agencies and higher education is maintained and strengthened. © 2012 The Wildlife Society.
Artificial roosts for tree‐roosting bats in northern Arizona
Authors: Mering Elisabeth D. , Chambers Carol L.
Published: October 2012

Bats use large (69 cm mean diameter) ponderosa pine (Pinus ponderosa) snags for maternity roosts in northern Arizona. Anthropogenic causes have altered forest structure, decreasing density of large snags. To examine use of artificial roosts for bats in these forests, we selected 26 sites and 2 treatments (clustered, single) using 1 type of roost (resin or wood) per site. At each site, we installed 4 roosts on ponderosa pine trees with a cluster of 3 roosts (south‐, east‐, or west‐facing; <20 m apart) and a single roost (south‐facing) 250–350 m away. We checked roosts every 2 weeks for use (guano or bats) and monitored internal temperatures every 2 hours from May through September in 2009 and 2010. Bats used 52% of roosts (19 roosts in 2009, 49 in 2010) at least once and colonized resin roosts sooner than wood roosts. Sites with clustered resin roosts were used more than single roosts. Bats used south‐ and east‐facing resin roosts more and these had warmer average temperatures than west‐facing roosts. We captured 47 bats of 5 species using artificial roosts. We only captured male bats from roosts in 2009, juveniles and females were also captured in 2010 but no maternity roosts were documented. We recommend that resin roosts placed in clusters on live trees be used to supplement natural roosts in ponderosa pine forests. Because use increased with time we suspect artificial roosts may be used for several years before establishment of maternity colonies. Artificial roosts require annual maintenance (e.g., waterproofing) to maintain function and can be expensive to install and maintain. © 2012 The Wildlife Society.
Toward a systems‐level understanding of the Hedgehog signaling pathway: defining the complex, robust, and fragile
Authors: Tran Pamela V. , Lachke Salil A. , Stottmann Rolf W.
Published: October 2012

The Hedgehog (Hh) signaling pathway plays a fundamental role in development and tissue homeostasis, governing cell proliferation and differentiation, as well as cell fate. Hh signaling is mediated by an intricate network of proteins that have positive and negative roles that work in concert to fine‐tune signaling output. Using feedback loops, redundancy and subcellular compartmentalization, the temporal and spatial dynamics of Hh signaling have evolved to be complex and robust. Yet developmental defects and cancers that arise from perturbation of the Hh pathway reflect specific pathway fragilities. Importantly, these fragile nodes and edges present opportunities for the design of targeted therapies. Despite these significant advances, unconnected molecular links within the Hh pathway still remain, many of which revolve around the dependence of Hh signaling on the primary cilium, an antenna‐like sensory organelle. A systems‐level understanding of Hh signaling and of ciliary biology will comprehensively define all nodes and edges of the Hh signaling network and will help identify precise therapeutic targets. WIREs Syst Biol Med 2013, 5:83–100. doi: 10.1002/wsbm.1193

This article is categorized under:

Biological Mechanisms > Cell Signaling

Developmental Biology > Developmental Processes in Health and Disease
Impact of hybrid techniques on laparoscopic major hepatectomies
Authors: Nitta Hiroyuki , Sasaki Akira , Otsuka Yuichiro , Tsuchiya Masaru , Kaneko Hironori , Wakabayashi Go
Published: October 2012

Purpose

To assess the types of liver resection, surgical approaches, and surgical outcomes, a questionnaire survey was undertaken at 32 member hospitals of the Japanese Endoscopic Liver Study Group.

Methods/results

Laparoscopic liver resections were performed on 837 patients. Major hepatectomy, including trisectionectomy, hemihepatectomy, and sectionectomy, constituted 106 of the cases. Laparoscopic major hepatectomy (LMH) was performed as totally laparoscopic (n = 8) (7.5 %), hand‐assisted (n = 4) (3.8 %), or laparoscopy‐assisted (n = 94) (88.7 %). None of the 106 patients were converted to open surgery. Complications occurred in 18 (17.0 %) of the 106 patients. One patient (0.9 %) had bleeding, two (1.9 %) had liver failure, six (5.7 %) had bile leakage, two (1.9 %) had pleural effusion, five (4.7 %) had surgical site infection, one (0.9 %) had pneumonia, and one (0.9 %) had acute respiratory distress syndrome. There were no perioperative deaths or gas embolisms.

Conclusion

In conclusion, a major hepatectomy using a hybrid technique is safe and feasible.
Dysfonction érectile: profil épidémiologique dans une population de sujets retraités au Sénégal
Authors: Diallo Y. , Coume M. , Ondo C. Ze , Diao B. , Sylla C.
Published: October 2012

Introduction

La dysfonction érectile (DE) constitue une pathologie qui revêt un aspect particulier chez le sujet retraité. Le but de cette étude est de rapporter les aspects épidémiologiques et d’analyser les facteurs de risque de la DE dans une population de retraités au Sénégal.

Méthodes

Il s’agissait d’une étude prospective réalisée sur une période de 12 mois, au niveau du Centre médico-social de l’Institution de prévoyance retraite du Sénégal (IPRES). Cette étude était basée sur un questionnaire auto-administré à des sujets retraités âgés d’au moins 55 ans. Sur 552 fiches distribuées, 537 ont été retenues.

Résultats

Sur l’ensemble de la population étudiée, 60,7 % des patients (n= 326) ont présenté une DE. L’âge moyen des sujets était de 68 ± 6,7 ans dans le groupe DE contre 65 ± 6,2 ans dans le groupe non DE. La durée moyenne d’intoxication tabagique était de 24,3 ± 14,4 ans. La duréemoyenne de consommation d’alcools était de 28,6 ± 15,5 ans avec des extrêmes de 3 et 63 ans. Le diabète était rapporté dans 67 cas (12,5 %) dont 18 (3,3 %) de découverte fortuite lors de l’enquête. La durée moyenne d’évolution des troubles érectiles était de 4,2 ± 4 ans avec des extrêmes de six mois et 20 ans.

Conclusion

La fonction érectile est un bon indicateur pertinent de qualité de vie. Cependant, les perturbations psychologiques, socio-économiques et médicales notées durant la période de mise en retraite ont une incidence notoire sur l’apparition, voire l’aggravation, de la DE.
Topoisomerase 1(TOP1) gene copy number in stage III colorectal cancer patients and its relation to prognosis
Authors: Rømer Maria Unni , Nygård Sune Boris , Christensen Ib Jarle , Nielsen Signe Lykke , Nielsen Kirsten Vang , Müller Sven , Smith David Hersi , Vainer Ben , Nielsen Hans Jørgen , Brünner Nils
Published: October 2012

Purpose

A Topoisomerase 1 (Top1) poison is frequently included in the treatment regimens for metastatic colorectal cancer (mCRC). However, no predictive biomarkers for Top1 poisons are available. We here report a study on the TOP1 gene copy number in CRC patients and its association with patient prognosis and tumor cell proliferation.

Experimental design

The study included TOP1 and CEN‐20 fluorescence in situ hybridization (FISH) analyses on formalin fixed paraffin embedded (FFPE) tissue sections from 154 stage III CRC chemonaïve patients. The frequencies of aberration in the TOP1 gene copy number, the CEN‐20 copy number and the TOP1/CEN‐20 ratio were analyzed and associated with overall survival (OS), time to recurrence (TTR) and in a subgroup analysis of rectal cancer patients only with time to local recurrence (LR in RC). Moreover, the TOP1 and CEN‐20 copy numbers were correlated with the tumor Ki67 proliferation index.

Results

35.7% of the tumors had an increased TOP1 copy number above 4n gene copies per cell and 28.6% and 9.7% had a TOP1/CEN‐20 ratio ≥1.5 or ≥2.0, respectively. The TOP1 copy number and the TOP1/CEN‐20 ratios were separately added into multivariate analyses as continuous variables, in which also age, gender, primary tumor location and Ki67 status were added as covariates. In contrast to the TOP1/CEN‐20 ratio, the TOP1 copy number was significantly associated with OS (HR: 0.62; 95% CI: 0.42–0.90; p = 0.01). Neither the TOP1 copy number nor the ratio was significantly associated with TTR and only the TOP1/CEN‐20 ratio was significantly associated with LR in RC (HR: 0.25; 95% CI: 0.08–0.83; p = 0.02). No significant correlation was found between the TOP1 copy number and proliferation, while a weak and inverse correlation between the CEN‐20 copy number and proliferation was observed.

Conclusions

This study showed that increased TOP1 gene copy numbers are frequent findings in cancer cells in stage III CRC tumors but unrelated to the proliferative status of the tumors. The association with prognosis is important to consider when planning and analyzing future studies investigating TOP1 as a potential predictive biomarker for Top1 poisons.
Caucasian children's fat mass: routine anthropometry v. air-displacement plethysmography
Authors: Michels Nathalie , Huybrechts Inge , Bammann Karin , Lissner Lauren , Moreno Luis , Peeters Maarten , Sioen Isabelle , Vanaelst Barbara , Vyncke Krishna , De Henauw Stefaan
Published: October 2012

The present paper will use fat mass percentage (FM%) obtained via BOD POD® air-displacement plethysmography (FMADP%) to examine the relative validity of (1) anthropometric measurements/indices and (2) of FM% assessed with equations (FMeq%) based on skinfold thickness and bioelectrical impedance (BIA). In 480 Belgian children (aged 5–11 years) weight, height, skinfold thickness (triceps and subscapular), body circumferences (mid-upper arm, waist and hip), foot-to-foot BIA (Tanita®) and FMADP% were measured. Anthropometric measurements and calculated indices were compared with FMADP%. Next, published equations were used to calculate FMeq% using impedance (equations of Tanita®, Tyrrell, Shaefer and Deurenberg) or skinfold thickness (equations of Slaughter, Goran, Dezenberg and Deurenberg). Both indices and equations performed better in girls than in boys. For both sexes, the sum of skinfold thicknesses resulted in the highest correlation with FMADP%, followed by triceps skinfold, arm fat area and subscapular skinfold. In general, comparing FMeq% with FMADP% indicated mostly an age and sex effect, and an increasing underestimation but less dispersion with increasing FM%. The Tanita® impedance equation and the Deurenberg skinfold equation performed the best, although none of the used equations were interchangeable with FMADP%. In conclusion, the sum of triceps and subscapular skinfold thickness is recommended as marker of FM% in the absence of specialised technologies. Nevertheless, the higher workload, cost and survey management of an immobile device like the BOD POD® remains justified.
Multiply charged ion emission from laser produced tungsten plasma
Authors: Ilyas B. , Dogar A.H. , Ullah S. , Mahmood N. , Qayyum A.
Published: October 2012

Plasma was generated by focusing 10 ns Nd:YAG (λ = 1064 nm) laser pulse on the thick tungsten target. The laser fluence at the target was varied in the range of 3.57–10.97 J/cm2. The ion emission from the expanding tungsten plasma was analyzed with the help of an ion collector and time-of-flight electrostatic ion energy analyzer. About 44 times rise in the ion charge per laser shot was observed in the investigated laser fluence range. The measured threshold fluence for onset of the tungsten plasma was 3.27 J/cm2. The estimated plume expansion coefficient Zinf/Xinf = 2.5 ± 0.2 was in agreement with the previous experimental studies and the predictions of self-similar plume expansion model. The electrostatic ion energy analyzer study showed that charge state of the W ions increases with the laser fluence and maximum ion charge state was 5+. It was observed that threshold fluence for appearance of a specific charge state can be measured. A clear correlation between the relative abundances of W(n−1)+, Wn+, and W(n+1)+ indicates that higher order charge states are most probably produced by stepwise ionization process.
‘A regular state of beautiful confusion’: governing by numbers and the contradictions of calculable space in New York City
Authors: ROSE-REDWOOD REUBEN
Published: October 2012

Historical scholarship on the spatial organization of cities has largely ignored the crucial role that house numbering has played as a political technology of spatial calculation since the eighteenth century. This article examines the spatial history of house numbering in Manhattan to illustrate how the numbering of buildings was a key strategy employed to reconfigure the city as a space of calculability. From the very outset, however, such calculable spaces of ‘number’ were riddled with contradictions, resulting in several rounds of spatial rationalization over the course of the eighteenth and nineteenth centuries. More than a mere technical concern alone, the history of house numbering in New York City exemplifies the spatial politics and temporal instabilities that have shaped the spaces of calculation in the modern city.
Translation and validation of the Persian version of the functional assessment of chronic illness therapy—Spiritual well-being scale (FACIT-Sp) among Muslim Iranians in treatment for cancer
Authors: Jafari Najmeh , Zamani Ahmadreza , Lazenby Mark , Farajzadegan Ziba , Emami Hamid , Loghmani Amir
Published: October 2012

Objective:

The Functional Assessment of Chronic Illness Therapy–Spiritual Well-Being (FACIT-Sp) scale is a valid and reliable instrument to provide an inclusive measure of spirituality in research and clinical practice. The aim of this study was to translate and investigate the reliability and validity of the Persian version of the FACIT-Sp.

Method:

The 12 item spiritual well-being subscale of the FACIT-Sp Version 4 was translated into the Persian language, Farsi, using the FACIT translation methodology. The questionnaire was administered to a diverse sample of 153 patients in treatment for cancer. Internal consistency was assessed by Cronbach's α coefficient, confirmatory factor analysis (CFA) was applied to assess construct validity, and regression analysis was used to assess the predictor role of the FACIT-Sp in health-related quality of life (HRQOL).

Results:

Cronbach's α reliability coefficient for the FACIT-Sp subscales ranged from 0.72 to 0.90. The CFA generally replicated the original conceptualization of the three subscales of the FACIT-Sp12 (Peace, Meaning, and Faith). All three subscales significant predicted HRQOL.

Significance of results:

The Persian version of the FACIT-Sp scale is a reliable and valid tool for the clinical assessment of, and research into, the spiritual well-being of Muslim Iranian and Farsi-speaking patients in other regions of the world who are in treatment for cancer.
“A Hot Municipal Contest”: Prohibition and Black Politics in Greenville, South Carolina, after Reconstruction
Authors: West Stephen A.
Published: October 2012

During the late nineteenth century, contests over prohibition gripped hundreds of American towns and cities, nowhere with greater consequences than in the post-Reconstruction South. This article examines those effects in Greenville, South Carolina, a small marketing and manufacturing center in the white-majority upcountry. During the 1880s, prohibition split white Democrats who had “redeemed” Greenville's town government just a few years before and led to a surge in voter registration and participation among African Americans. The liquor question's repercussions for politics in the Gilded Age South have been largely neglected, both by social historians of prohibition and by political historians, who have failed to see it as one of the issues that roiled the region's politics between Reconstruction and the Populist rebellion. This article also emphasizes the overlooked importance of municipal elections and governance—even in so small a place as Greenville—as an arena for African Americans’ political activity. Greenville's black voters used their influence during the 1880s to achieve modest but tangible gains in education and municipal services and to erect at least a partial bulwark against the tide of white supremacy. These developments were part of a region-wide revival in African Americans’ municipal power, which Southern Democrats were careful to target in their disfranchising campaigns as the century drew to close.
Dating small fresh lunar craters with Mini‐RF radar observations of ejecta blankets
Authors: Bell Samuel W. , Thomson Bradley J. , Dyar M. Darby , Neish Catherine D. , Cahill Joshua T. S. , Bussey D. B. J.
Published: October 2012

The ages of large impact craters on the Moon can be estimated by measuring the size‐frequency distribution of smaller craters superimposed on their ejecta, but applying this method to individual craters under ∼3 km in diameter remains difficult due to their limited areal extent. The ejecta blankets of fresh lunar impact craters are expressed as halos of optical and radar bright material that gradually fade with time. Although compositional differences make inferring crater ages from optical albedo problematic, radar is less sensitive to composition and thus may provide a more reliable means of estimating age. In this work, we use radar data from the Miniature Radio Frequency (Mini‐RF) instrument on the Lunar Reconnaissance Orbiter (LRO) to characterize the radar backscatter of large numbers of ejecta blankets. By analyzing the size‐frequency distribution of these craters, we show that the lifetime of the radar‐bright discontinuous ejecta blanket varies with crater diameter in a predictable way for craters with diameters between 0.45 and 5 km. Absolute ages of individual craters can then be estimated by combining this empirically derived model with estimates of the relative degradation state of each individual crater. The lifetimes of radar‐bright discontinuous ejecta blankets are significantly shorter in the highlands than the maria, although this is likely due to local topography, creating difficulties in applying the method to the highlands. The cosmic ray exposure age of South Ray Crater, a fresh crater visited by Apollo 16, provides confirmation of these results. This method therefore provides a new way to accurately date small, fresh craters using the Mini‐RF data set.
Seasonal and diurnal variation of geomagnetic activity: Russell‐McPherron effect during different IMF polarity and/or extreme solar wind conditions
Authors: Zhao H. , Zong Q.‐G.
Published: October 2012

The Russell‐McPherron (R‐M) effect is one of the most prevailing hypotheses accounting for semiannual variation of geomagnetic activity. To validate the R‐M effect and investigate the difference of geomagnetic activity variation under different interplanetary magnetic field (IMF) polarity and during extreme solar wind conditions (interplanetary shock), we have analyzed 42 years interplanetary magnetic field and geomagnetic indices data and 1270 SSC (storm sudden commencement) events from the year 1968 to 2010 by defining the R‐M effect with positive/negative IMF polarity (IMF away/toward the Sun). The results obtained in this study have shown that the response of geomagnetic activity to the R‐M effect with positive/negative IMF polarity are rather profound: the geomagnetic activity is much more intense around fall equinox when the direction of IMF is away the Sun, while much more intense around spring equinox when the direction of IMF is toward the Sun. The seasonal and diurnal variation of geomagnetic activity after SSCs can be attributed to both R‐M effect and the equinoctial hypothesis; the R‐M effect explains most part of variance of southward IMF, while the equinoctial hypothesis explains similar variance of ring current injection and geomagnetic indices as the R‐M effect. However, the R‐M effect with positive/negative IMF polarity explains the difference between SSCs with positive/negative IMFByaccurately, while the equinoctial hypothesis cannot explain such difference at the spring and fall equinoxes. Thus, the R‐M effect with positive/negative IMF polarity is more reasonable to explain seasonal and diurnal variation of geomagnetic activity under extreme solar wind conditions.
Temporal and spatial effects of subauroral polarization streams on the thermospheric dynamics
Authors: Wang Hui , Lühr Hermann , Ritter Patricia , Kervalishvili Guram
Published: October 2012

Based on two years of Subauroral Polarization Streams (SAPS) events detected by DMSP satellites in the dusk‐premidnight sector, we have studied the temporal and spatial effects of SAPS on thermospheric quantities. The events are divided into two different MLT (magnetic local time) groups covered by F13 and F14/15. Concurrent CHAMP observations taken between −30° and +60° in longitude (−2 h and +4 h MLT) with respect to the SAPS detection location and within a time window of 1.5 h before and 3 h after the SAPS detection time are used for comparison. For the first time the spatial and temporal effects of SAPS are shown. SAPS have great influences on the zonal wind in all MLT bins (17–21 MLT) around the F13 MLT sector, with the largest effect appearing around 19 MLT, about 0–2 hours MLT after SAPS onset. SAPS have relatively little effect around 23–24 MLT, as deduced from F14/15 SAPS. For most cases the zonal wind peaks in the first orbit, concurrent with the SAPS onset. But around 19 MLT the zonal wind attains peak velocities about 1.5 h after the SAPS detection. This is claimed to be related to the longer persistence of SAPS events in this MLT sector than in other sectors. The background air density gets enhanced by SAPS with the most prominent variation occurring around 19 MLT. There are density bulges appearing around the SAPS latitude. The electron density trough gets deepened and attains the minimum in the first orbit after the SAPS onset. The largest depletion can also be found around 19 MLT. Both the eastward and westward Hall currents (electrojets) get strengthened right after SAPS onset. The zonal wind peaks 2°–3° in latitudes equatorward of the eastward electrojet.
Understanding volcano hydrothermal unrest from geodetic observations: Insights from numerical modeling and application to White Island volcano, New Zealand
Authors: Fournier Nicolas , Chardot Lauriane
Published: October 2012

In this work we assess how volcano geodetic observations can be used to gain insights into hydrothermal system dynamics. We designed a range of numerical models of hydrothermal unrest and associated ground deformation caused by the thermo–poro–elastic response of the substratum. Throughout an episode of unrest, ground deformation is consistently first controlled by the poroelastic response of the substratum to pore pressure increase near the injection area. Later, thermal expansion may become the dominant process if the injection is sustained. We inverted these synthetic geodetic data using simple conventional pressure source models and compared the retrieved source characteristics with that of the synthetic hydrothermal systems. Simple pressure source models can reproduce well ground deformation caused by pore–pressure increase at depth. Most importantly, the pressure source's depth retrieved from the inversions corresponds to those of the area of injection of the hot magmatic fluids into the hydrothermal system. When the thermoelastic contribution to ground deformation becomes significant through time, simple point or spherical finite sources cannot reproduce the ground deformation signal. This allows one to determine whether observed ground deformation events due to hydrothermal unrest are distinct episodes of unrest and injection at depth, or whether one may correspond to the late, thermally‐controlled phase of a previous event. Finally we applied this strategy to White Island volcano, New Zealand, to gain insights into the processes driving the last two episodes of ground uplift.
Microseisms and hum from ocean surface gravity waves
Authors: Traer James , Gerstoft Peter , Bromirski Peter D. , Shearer Peter M.
Published: October 2012

Ocean waves incident on coasts generate seismic surface waves in three frequency bands via three pathways: direct pressure on the seafloor (primary microseisms, PM), standing waves from interaction of incident and reflected waves (double‐frequency microseisms, DF), and swell‐transformed infragravity wave interactions (the Earth's seismic hum). Beamforming of USArray seismic data shows that the source azimuths of the generation regions of hum, PM and DF microseisms vary seasonally, consistent with hemispheric storm patterns. The correlation of beam power with wave height over all azimuths is highest in near‐coastal waters. Seismic signals generated by waves from Hurricane Irene and from a storm in the Southern Ocean have good spatial and temporal correlation with nearshore wave height and peak period for all three wave‐induced seismic signals, suggesting that ocean waves in shallow water commonly excite hum (via infragravity waves), PM, and DF microseisms concurrently.
Structural evolution of the Madden‐Julian Oscillation from COSMIC radio occultation data
Authors: Zeng Zhen , Ho Shu‐Peng , Sokolovskiy Sergey , Kuo Ying‐Hwa
Published: October 2012

The atmospheric temperature and specific humidity profiles derived from 4 years of Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) radio occultation (RO) measurements during the boreal winter (November thru April in 2006–2010) were employed to study the large‐scale vertical structure of the Madden‐Julian Oscillation (MJO). In a composited MJO cycle, both RO temperature and moisture anomalies propagate eastward along with the enhanced MJO convection over the Indo‐Pacific region. In the same region, the RO temperature anomaly is positively correlated with the convection (Tropical Rainfall Measuring Mission (TRMM) rainfall) anomaly in the middle and upper troposphere (800 hPa–200 hPa) and negatively correlated in the lower troposphere and at the tropopause. A positive RO moisture anomaly has a westward tilt below 300 hPa and is well associated with the convection anomaly. RO bending angle and refractivity anomalies show vertical structure similar to that of temperature MJO anomaly above ∼300 hPa and to that of the moisture anomaly below that. These salient MJO features agree well with those revealed by global reanalysis data and meteorological satellite observations, such as the Atmospheric Infrared Sounder (AIRS), even though RO anomalies exhibit sharper structure at the tropopause region due to the higher vertical resolution of the RO. Investigation of the cold‐point tropopause anomaly indicates that the enhanced convection is preceded by cooling of the tropopause and followed by lowering of the tropopause height. The MJO moisture structures during two boreal winters, November 2007–April 2008 (La Niña) and November 2009–April 2010 (El Niño), are individually presented to demonstrate the El Niño‐Southern Oscillation (ENSO) effect on the MJO structure.
TAK-242, a small-molecule inhibitor of Toll-like receptor 4 signalling, unveils similarities and differences in lipopolysaccharide- and lipidinduced inflammation and insulin resistance in muscle cells
Authors: Hussey Sophie E. , Liang Hanyu , Costford Sheila R. , Klip Amira , DeFronzo Ralph A. , Sanchez-Avila Alicia , Ely Brian , Musi Nicolas
Published: October 2012

Emerging evidence suggests that TLR (Toll-like receptor) 4 and downstream pathways [MAPKs (mitogen-activated protein kinases) and NF-κB (nuclear factor κB)] play an important role in the pathogenesis of insulin resistance. LPS (lipopolysaccharide) and saturated NEFA (non-esterified fatty acids) activate TLR4, and plasma concentrations of these TLR4 ligands are elevated in obesity and Type 2 diabetes. Our goals were to define the role of TLR4 on the insulin resistance caused by LPS and saturated NEFA, and to dissect the independent contribution of LPS and NEFA to the activation of TLR4-driven pathways by employing TAK-242, a specific inhibitor of TLR4. LPS caused robust activation of the MAPK and NF-κB pathways in L6 myotubes, along with impaired insulin signalling and glucose transport. TAK-242 completely prevented the inflammatory response (MAPK and NF-κB activation) caused by LPS, and, in turn, improved LPS-induced insulin resistance. Similar to LPS, stearate strongly activated MAPKs, although stimulation of the NF-κB axis was modest. As seen with LPS, the inflammatory response caused by stearate was accompanied by impaired insulin action. TAK-242 also blunted stearate-induced inflammation; yet, the protective effect conferred by TAK-242 was partial and observed only on MAPKs. Consequently, the insulin resistance caused by stearate was only partially improved by TAK-242. In summary, TAK-242 provides complete and partial protection against LPS- and NEFA-induced inflammation and insulin resistance, respectively. Thus, LPS-induced insulin resistance depends entirely on TLR4, whereas NEFA works through TLR4-dependent and -independent mechanisms to impair insulin action.
Inversion operators in finite phase plane
Authors: Zak J.
Published: October 2012

The inversion operators on a lattice in finite phase plane are used for building a complete set of mutually orthogonal Hermitian operators. The lattice is given by tc in the x direction and by \documentclass[12pt]{minimal}\begin{document}$s\hbar \frac{2\pi }{Mc}$\end{document}sℏ2πMc in the p-direction; c is an arbitrary length constant and M is the dimension of the space; s and t assume the values from 0 to M − 1. For M odd the M2 inversion operators on the lattice form a complete set of mutually orthogonal operators. For M even we assign a sum of 4 inversion operators (a quartet) to each site of the lattice (t, s). We prove that these quartets for t, s = 0, 1, …, M − 1 form a mutually orthogonal set of M2 Hermitian operators.
Momentum spectrometer for electron-electron coincidence studies on superconductors
Authors: Wallauer Robert , Voss Stefan , Foucar Lutz , Bauer Tobias , Schneider Deborah , Titze Jasmin , Ulrich Birte , Kreidi Katharina , Neumann Nadine , Havermeier Tilo , Schöffler Markus , Jahnke Till , Czasch Achim , Schmidt Lothar , Kanigel Amit , Campuzano Juan Carlos , Jeschke Harald , Valenti Roser , Müller Andreas , Berner Götz , Sing Michael , Claessen Ralph , Schmidt-Böcking Horst , Dörner Reinhard
Published: October 2012

We present a new experimental setup to study electron-electron coincidences from superconducting surfaces. In our approach, electrons emitted from a surface are projected onto a time- and position-sensitive microchannel plate detector with delayline position readout. Electrons that are emitted within 2 π solid angle with respect to the surface are detected in coincidence. The detector used is a hexagonal delayline detector with enhanced multiple hit capabilities. It is read out with a Flash analog-to-digital converter. The three-dimensional momentum vector is obtained for each electron. The intrinsic dead time of the detector has been greatly reduced by implementing a new algorithm for pulse analysis. The sample holder has been matched to fit the spectrometer while being capable of cooling down the sample to 4.5 K during the measurement and heating it up to 420 K for the cleaning procedure.
New device to measure dynamic intrusion/extrusion cycles of lyophobic heterogeneous systems
Authors: Guillemot Ludivine , Galarneau Anne , Vigier Gérard , Abensur Thierry , Charlaix Élisabeth
Published: October 2012

Lyophobic heterogeneous systems (LHS) are made of mesoporous materials immersed in a non-wetting liquid. One application of LHS is the nonlinear damping of high frequency vibrations. The behaviour of LHS is characterized by P − ΔV cycles, where P is the pressure applied to the system, and ΔV its volume change due to the intrusion of the liquid into the pores of the material, or its extrusion out of the pores. Very few dynamic studies of LHS have been performed until now. We describe here a new apparatus that allows us to carry out dynamic intrusion/extrusion cycles with various liquid/porous material systems, controlling the temperature from ambient to 120 °C and the frequency from 0.01 to 20 Hz. We show that for two LHS: water/MTS and Galinstan/CPG, the energy dissipated during one cycle depends very weakly on the cycle frequency, in strong contrast to conventional dampers.
Isothermal titration calorimetry as a tool to determine the thermodynamics of demicellization processes
Authors: Kessler Anne , Zeeb Benjamin , Kranz Bertolt , Menéndez-Aguirre Orquídea , Fischer Lutz , Hinrichs Jörg , Weiss Jochen
Published: October 2012

Demicellization of a 90 mM sodium dodecyl sulfate (SDS) solution in water at 10, 22, and 30 °C was studied by isothermal titration calorimetry (ITC). ΔH of the demicellization process was strongly temperature dependent, having an exothermic progression (−20.4 ± 0.9 kJ/mol, max) at 10 °C and an endothermic one (3.7 ± 1.2 kJ/mol, max) at 30 °C. ΔH for micelle dilution followed a slightly endothermic progression (0.9 ± 0.5 kJ/mol at 30 °C, 0.7 ± 1.3 kJ/mol at 22 °C, and 0.0 ± 0.5 kJ/mol at 10 °C) at all studied temperatures. No differences in ΔH for micelle dilution and demicellization was observed at 22 °C. The temperature dependence of ΔH measured by ITC could be related to hydrophobic interactions. Therefore, ITC was shown to be a useful tool to describe the thermodynamics of demicellization processes and in addition to determine alterations in ΔH caused by changes in hydrophobic and steric/electrostatic interactions.
Energy and electromagnetism of a differential k-form
Authors: Navarro J. , Sancho J. B.
Published: October 2012

Let X be a smooth manifold of dimension 1 + n endowed with a Lorentzian metric g. The energy tensor of a 2-form F is locally defined as \documentclass[12pt]{minimal}\begin{document}$T_{ab}\break := \, - \left( {F_a}^{i} F_{bi} - \frac{1}{4} \, F^{ij} F_{ij} g_{ab} \right)$\end{document}Tab:=−FaiFbi−14FijFijgab. In this paper we characterize this tensor as the only 2-covariant natural tensor associated to a Lorentzian metric and a 2-form that is independent of the unit of scale and satisfies certain condition on its divergence. This characterization is motivated on physical grounds, and can be used to justify the Einstein–Maxwell field equations. More generally, we characterize in a similar manner the energy tensor associated to a differential form of arbitrary order k. Finally, we develop a generalized theory of electromagnetism where charged particles are not punctual, but of an arbitrary fixed dimension p. In this theory, the electromagnetic field F is a differential form of order 2 + p and its electromagnetic energy tensor is precisely the energy tensor associated to F.
Local chemical potential and pressure tensor in inhomogeneous nanoconfined fluids
Authors: Eslami Hossein , Mehdipour Nargess
Published: October 2012

There are many simulations in the literature to study the behavior of nanoconfined fluids between solid surfaces. Among them, a class of methods focuses on tuning the pore width in such a way that the fluid in confinement has the same tangential component of pressure as the bulk fluid. The main idea behind these methods is based on the ansatz that in equilibrium (between the fluid in confinement and the bulk fluid) the tangential component of pressure of the confined fluid is equal to the pressure of the bulk fluid at the same temperature. As there is no evidence in the literature on the validity of this ansatz, in this work we have performed molecular dynamics simulations on a large number of nanoconfined Lennard-Jones systems to evaluate its validity. For this purpose, big simulation boxes are chosen, to enable us to directly calculate the particle-particle interactions, and hence, reduce the long-range corrections to the local pressures and local chemical potentials in the inhomogeneous fluid. Simulating the confined fluid at an average tangential component of pressure equal to the pressure of the bulk fluid at the same temperature, we have calculated the chemical potentials in the pore and compared them with the corresponding bulk value. Our calculated results indicate that the chemical potentials in the pore show oscillatory behavior with respect to the pore width. Pronounced deviations in the chemical potentials from the corresponding bulk value are observed in narrower pores, compared to wider pores. Therefore, the results of the present simulations rule out the validity of the above-mentioned ansatz.
Quantum ring solitons and nonlocal effects in plasma wake field excitations
Authors: Fedele R. , Tanjia F. , De Nicola S. , Jovanović D. , Shukla P. K.
Published: October 2012

A theoretical investigation of the quantum transverse beam motion for a cold relativistic charged particle beam travelling in a cold, collisionless, strongly magnetized plasma is carried out. This is done by taking into account both the individual quantum nature of the beam particles (single-particle uncertainty relations and spin) and the self consistent interaction generated by the plasma wake field excitation. By adopting a fluid model of a strongly magnetized plasma, the analysis is carried out in the overdense regime (dilute beams) and in the long beam limit. It is shown that the quantum description of the collective transverse beam dynamics is provided by a pair of coupled nonlinear governing equations. It comprises a Poisson-like equation for the plasma wake potential (driven by the beam density) and a 2D spinorial Schrödinger equation for the wave function, whose squared modulus is proportional to the beam density, that is obtained in the Hartree's mean field approximation, after disregarding the exchange interactions. The analysis of this pair of equations, which in general exhibits a strong nonlocal character, is carried out analytically as well as numerically in both the linear and the nonlinear regimes, showing the existence of the quantum beam vortices in the form of Laguerre-Gauss modes and ring envelope solitons, respectively. In particular, when the relation between the plasma wake field response and the beam probability density is strictly local, the pair of the governing equations is reduced to the 2D Gross-Pitaevskii equation that allows one to establish the conditions for the self focusing and collapse. These conditions include the quantum nature of the beam particles. Finally, when the relation between the plasma wake field response and the beam probability density is moderately nonlocal, the above pair of equations permits to follow the spatio-temporal evolution of a quantum ring envelope soliton. Such a structure exhibits small or violent breathing, but it remains very stable for long time.