bluuebunny/crossref_metadata_2025 huggingface dataset:
Multivariate Block-Support Simulation of the Yandi Iron Ore Deposit, Western Australia
Authors: Boucher Alexandre , Dimitrakopoulos Roussos
Published: May 2012

Mineral deposits frequently contain several elements of interest that are spatially correlated and require the use of joint geostatistical simulation techniques in order to generate models preserving their spatial relationships. Although joint-simulation methods have long been available, they are impractical when it comes to more than three variables and mid to large size deposits. This paper presents the application of block-support simulation of a multi-element mineral deposit using minimum/maximum autocorrelation factors to facilitate the computationally efficient joint simulation of large, multivariable deposits. The algorithm utilized, termeddbmafsim, transforms point-scale spatial attributes of a mineral deposit into uncorrelated service variables leading to the generation of simulated realizations of block-scale models of the attributes of interest of a deposit. Thedbmafsimalgorithm is utilized at the Yandi iron ore deposit in Western Australia to simulate five cross-correlated elements, namely Fe, SiO2, Al2O3, P and LOI, that are all critical in defining the quality of iron ore being produced. The block-scale simulations reproduce the direct- and cross-variograms of the elements even though only the direct variograms of the service variables have to be modeled. The application shows the efficiency, excellent performance and practical contribution of thedbmafsimalgorithm in simulating large multi-element deposits.
Bacterial succession during 500 years of soil development under agricultural use
Authors: Cui Jun , Meng Han , Nie Ming , Chen Xueping , Li Zhaolei , Bu Naishun , Li Bo , Chen Jiakuan , Quan Zhexue , Fang Changming
Published: May 2012

Soil bacterial succession under intensive anthropogenic disturbances is not well known. Using terminal restriction fragment length polymorphisms and 454 pyrosequencing of 16S rRNA genes, this study investigated how soil bacterial diversity and community structure changed under two agricultural land uses (paddy rice and upland cropping) in relation to soil development along a 500‐year chronosequence created by intermittent reclamation of estuarine salt marshes. Multivariate analysis revealed orderly changes in soil physicochemical properties and bacterial community structure with time, confirming the occurrence of soil development and bacterial succession. Patterns of soil development and bacterial succession resembled each other, with recent land uses affecting their trajectories but not the overall direction. Succession of bacterial community structure was mainly associated with changes in α‐Proteobacteria and Verrucomicrobia. Two stages of bacterial succession were observed, a dramatic‐succession stage during the first several decades when bacterial diversity increased evidently and bacterial community structure changed rapidly, and a long gradual‐succession stage that lasted for centuries. Canonical correspondence analysis identified soil Na+, potentially mineralizable nitrogen, total phosphorous, and crystallinity of iron oxyhydrates as potential environmental drivers of bacterial succession. To conclude, orderly succession of soil bacterial communities occurred along with the long‐term development of agroecosystems, which in turn was associated with soil physicochemical changes over time.
La dysfonction érectile au Congo : premières données sur la fréquence de ce motif de consultation et profil clinique au centre hospitalier universitaire de Brazzaville
Authors: Bouya A. P. , Odzebe A. W. S. , Mayala Maognan R. , Ondongo Atipo A. M. , Andzouana N. , Monabeka H. G.
Published: May 2012

Objectif

Étudier les facteurs de risque et les résultats des investigations diagnostiques de la dysfonction érectile en consultation urologique à Brazzaville.

Méthodologie

Il s’agissait d’une étude prospective concernant 40 patients âgés de 20 à 80 ans vus en consultation externe d’urologie-andrologie du centre hospitalier et universitaire de Brazzaville pour dysfonction érectile, de décembre 2009 à août 2010. Les renseignements de la fiche d’enquête concernaient l’âge, les antécédents, les facteurs de risque, les caractéristiques cliniques et paracliniques, et l’Index international de la fonction érectile (IIEF-5) dans sa version française. Les logiciels Epi info version 3.5.1 et SPSS 11.5 ont permis l’enregistrement et l’analyse des données. Le test de Khi 2 a été utilisé pour la comparaison des variables quantitatives et le test d’analyse de variance (ANOVA) pour les variables qualitatives. Le seuil de significativité était de 0,05.

Résultats

La fréquence de la dysfonction érectile était de 14,7 %, avec une moyenne d’âge de 50,7 ± 12,3 ans (27–77 ans). La tranche d’âge de 40 à 50 ans était la plus touchée. La durée moyenne de l’ancienneté était de 2,6 ± 2,2 ans (trois mois à neuf ans). Les pathologies associées ont été l’HTA (22,5 %) et le diabète (15 %). Les facteurs de risque retrouvés ont été l’alcoolisme (75 %), le tabagisme (25 %) et l’obésité (12,5 %). La dysfonction érectile était sévère dans 47,5 % des cas et la sévérité était corrélée à l’âge. Elle était insupportable dans 40 % des cas.

Conclusion

La dysfonction érectile concerne 14,7 % des patients vus en consultation urologique. Ce chiffre est certainement sous-estimé en raison des tabous et de la pudeur.
Situated knowledge–situated legitimacy: Consequences of citizen participation in local environmental governance
Authors: Leino Helena , Peltomaa Juha
Published: May 2012

This article examines how situated knowledge produced by citizens affects the construction and understanding of legitimacy in local environmental governance. By scrutinising a case from Finland where local citizens decided to take lake restoration in their own hands, we demonstrate how legitimacy is constructed in a specific local context. The main concepts used to interpret this dynamic are situated knowledge (Haraway, 1988; Lang, 2011) and situated legitimacy (Connelly, Richardson, & Miles, 2006). The paper shows how the local traditions together with the historical and social context have distinct effects on the construction of situated knowledge. Further, situated knowledge not only frames the boundaries and possibilities of local action, but also shapes the interpretations of legitimacy. Approaching the construction of knowledge and legitimacy from this perspective challenges the customary understanding of context in participatory practices and, as we suggest, has also the ability to improve these processes.
Effect of changes in an FFQ: comparing data from two national dietary survey instruments among 2-year-olds
Authors: Kristiansen A. L. , Lillegaard I. T. L. , Lande B. , Andersen L. F.
Published: May 2012

In the interpretation of dietary trends, it is important to consider the potential effect of modifications in the dietary assessment method. Therefore, our objective was to explore the comparability of data obtained at two time points by a semi-quantitative FFQ (SFFQ) which has had slight modifications over time. In the national dietary surveys among Norwegian 2-year-olds, diet was assessed by an SFFQ which underwent modifications between the 1999 survey and the 2007 survey. In the present study, fifty-nine families with a 2-year-old child participated by completing both the SFFQ in a crossover design within a month's time. With regard to the reported intake of energy and nutrients, the largest significant differences observed between the two questionnaires were for carbohydrates and added sugar. According to intake of food groups, significant differences were observed for five out of sixteen food groups. Spearman's correlation coefficients for energy, nutrients and food groups ranged from 0·43 (Ca) to 0·85 (soft drinks). Most Bland–Altman plots indicated broad limits of agreement. The differences between the two questionnaires can be explained by changes in the questionnaires, changes in the food composition databases used and random variation. Comparing differences between the questionnaires by maternal educational level, number of children and type of day care revealed minor differences. In conclusion, this study showed that at the group level there was reasonable comparability between the two questionnaires, except for carbohydrates, added sugar and some food groups. Moreover, there were moderate to high correlations for energy, nutrients and food groups.
Effect of long-term, low-dose clarithromycin on T helper 2 cytokines, eosinophilic cationic protein and the ‘regulated on activation, normal T cell expressed and secreted’ chemokine in the nasal secretions of patients with nasal polyposis
Authors: Perić A , Vojvodić D , Matković-Jožin S
Published: May 2012

Background:

Little is known about the effects of macrolides on the cytokines and chemokines that modulate the function of eosinophils in nasal polyposis.

Methods:

Twenty-two non-allergic and 18 allergic patients with nasal polyps were administered clarithromycin 500 mg/day (single oral dose) for eight weeks. We measured the nasal secretion levels of the T helper 2 (also known as Th2) cytokines interleukin 4, 5 and 6, the ‘regulated on activation, normal T cell expressed and secreted’ (also known as RANTES) chemokine, and the eosinophilic cationic protein, before and after treatment.

Results:

After clarithromycin treatment, we found reduced levels of the ‘regulated on activation, normal T cell expressed and secreted’ chemokine in samples from both non-allergic and allergic patients (p < 0.05). Clarithromycin treatment decreased the levels of eosinophilic cationic protein only in non-allergic patients (p < 0.05), and decreased the level of interleukin 6 only in allergic patients (p < 0.05). Decreased levels of the ‘regulated on activation, normal T cell expressed and secreted’ chemokine were associated with a reduction in polyp size both in non-allergic and allergic patients.

Conclusion:

Clarithromycin has a strong anti-inflammatory effect in nasal polyposis, but has different immunomodulatory effects in allergic and non-allergic nasal polyposis patients.
Prevalence of MTHFR C677T and MS A2756G polymorphisms in major depressive disorder, and their impact on response to fluoxetine treatment
Authors: Mischoulon David , Lamon-Fava Stefania , Selhub Jacob , Katz Judith , Papakostas George I. , Iosifescu Dan V. , Yeung Albert S. , Dording Christina M. , Farabaugh Amy H. , Clain Alisabet J. , Baer Lee , Alpert Jonathan E. , Nierenberg Andrew A. , Fava Maurizio
Published: May 2012

Objective

To examine the prevalence of the C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene and the A2756G polymorphism of methionine synthase (MS), and their impact on antidepressant response.

Methods

We screened 224 subjects (52% female, mean age 39 ± 11 years) with SCID-diagnosed major depressive disorder (MDD), and obtained 194 genetic samples. 49 subjects (49% female, mean age 36 ± 11 years) participated in a 12-week open clinical trial of fluoxetine 20–60 mg/day. Association between clinical response and C677T and A2756G polymorphisms, folate, B12, and homocysteine was examined.

Results

Prevalence of the C677T and A2756G polymorphisms was consistent with previous reports (C/C = 41%, C/T = 47%, T/T = 11%, A/A = 66%, A/G = 29%, G/G = 4%). In the fluoxetine-treated subsample (n = 49), intent-to-treat (ITT) response rates were 47% for C/C subjects and 46% for pooled C/T and T/T subjects (nonsignificant). ITT response rates were 38% for A/A subjects and 60% for A/G subjects (nonsignificant), with no subjects exhibiting the G/G homozygote. Mean baseline plasma B12 was significantly lower in A/G subjects compared to A/A, but folate and homocysteine levels were not affected by genetic status. Plasma folate was negatively associated with treatment response.

Conclusion

The C677T and A2756G polymorphisms did not significantly affect antidepressant response. These preliminary findings require replication in larger samples.
The role of a lifetime history of oppositional defiant and conduct disorders in adults with ADHD: implications for clinical practice
Authors: Vitola Eduardo S. , Salgado Carlos A. I. , Silva Katiane L. , Karam Rafael G. , Victor Marcelo M. , Mota Nina R. , Contini Verônica , Picon Felipe A. , Guimarães-da-Silva Paula O. , Giordani Rafael S. , Rohde Luis A. , Belmonte-de-Abreu Paulo , Bau Claiton H. D. , Grevet Eugenio H.
Published: May 2012

Introduction

Attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD) are frequently co-occurring disorders in children and adolescents. However, their clinical status among adults is still under discussion. This study analyzes how the current clinical presentation of adult ADHD might be influenced by a lifetime history of CD and ODD.

Methods

We compared three groups of patients: ADHD without history of CD/ODD (n = 178), ADHD + history of ODD (n = 184), and ADHD + history of CD (n = 96).

Results

A history of CD (and to a lower extent ODD) is associated with a more severe and externalizing profile.

Conclusion

Past CD and ODD entail a significant negative mental health impact on persistent ADHD, reinforcing the importance of actively assessing the developmental history of adult ADHD patients.
Clinical features of tic-related obsessive-compulsive disorder: results from a large multicenter study
Authors: de Alvarenga Pedro Gomes , de Mathis Maria Alice , Dominguez Alves Anna Claudia , do Rosário Maria Conceição , Fossaluza Victor , Hounie Ana Gabriela , Miguel Euripedes Constantino , Torres Albina Rodrigues
Published: May 2012

Objective

To evaluate the clinical features of obsessive-compulsive disorder (OCD) patients with comorbid tic disorders (TD) in a large, multicenter, clinical sample.

Method

A cross-sectional study was conducted that included 813 consecutive OCD outpatients from the Brazilian OCD Research Consortium and used several instruments of assessment, including the Yale-Brown Obsessive-Compulsive Scale, the Dimensional Yale-Brown Obsessive-Compulsive Scale, the Yale Global Tic Severity Scale (YGTSS), the USP Sensory Phenomena Scale, and the Structured Clinical Interview for DSM-IV Axis I Disorders.

Results

The sample mean current age was 34.9 years old (SE 0.54), and the mean age at obsessive-compulsive symptoms (OCS) onset was 12.8 years old (SE 0.27). Sensory phenomena were reported by 585 individuals (72% of the sample). The general lifetime prevalence of TD was 29.0% (n= 236), with 8.9% (n= 72) presenting Tourette syndrome, 17.3% (n= 141) chronic motor tic disorder, and 2.8% (n= 23) chronic vocal tic disorder. The mean tic severity score, according to the YGTSS, was 27.2 (SE 1.4) in the OCD + TD group. Compared to OCD patients without comorbid TD, those with TD (OCD + TD group,n= 236) were more likely to be males (49.2% vs. 38.5%, p < .005) and to present sensory phenomena and comorbidity with anxiety disorders in general: separation anxiety disorder, social phobia, specific phobia, generalized anxiety disorder, post-traumatic stress disorder, attention-deficit hyperactivity disorder, impulse control disorders in general, and skin picking. Also, the “aggressive,” “sexual/religious,” and “hoarding” symptom dimensions were more severe in the OCD + TD group.

Conclusion

Tic-related OCD may constitute a particular subgroup of the disorder with specific phenotypical characteristics, but its neurobiological underpinnings remain to be fully disentangled.
VALENTINI’S CUT-ELIMINATION FOR PROVABILITY LOGIC RESOLVED
Authors: GORÉ RAJEEV , RAMANAYAKE REVANTHA
Published: May 2012

Valentini (1983) has presented a proof of cut-elimination for provability logic GL for a sequent calculus using sequents built from sets as opposed to multisets, thus avoiding an explicit contraction rule. From a formal point of view, it is more syntactic and satisfying to explicitly identify the applications of the contraction rule that are ‘hidden’ in proofs of cut-elimination for such sequent calculi. There is often an underlying assumption that the move to a proof of cut-elimination for sequents built from multisets is straightforward. Recently, however, it has been claimed that Valentini’s arguments to eliminate cut do not terminate when applied to a multiset formulation of the calculus with an explicit rule of contraction. The claim has led to much confusion and various authors have sought new proofs of cut-elimination for GL in a multiset setting.

Here we refute this claim by placing Valentini’s arguments in a formal setting and proving cut-elimination for sequents built from multisets. The use of sequents built from multisets enables us to accurately account for the interplay between the weakening and contraction rules. Furthermore, Valentini’s original proof relies on a novel induction parameter called “width” which is computed ‘globally’. It is difficult to verify the correctness of his induction argument based on “width.” In our formulation however, verification of the induction argument is straightforward. Finally, the multiset setting also introduces a new complication in the case of contractions above cut when the cut-formula is boxed. We deal with this using a new transformation based on Valentini’s original arguments.

Finally, we discuss the possibility of adapting this cut-elimination procedure to other logics axiomatizable by formulae of a syntactically similar form to the GL axiom.
Terror Management and Biculturalism
Authors: Goncalves Portelinha Isabelle , Verlhiac Jean-François , Meyer Thierry , Hutchison Paul
Published: May 2012

Terror management theory posits that cultural worldviews provide protection against death-related anxiety. To the extent that worldviews often encompass competing beliefs, the present research investigated the effect of the salience of an incompatibility between worldview elements. French nationals of second- or third-immigrant generation (N = 193) were exposed to compatible or incompatible aspects of their cultural identities and then induced to contemplate their own death or a neutral topic. Participants reminded of their mortality renounced their ethnic identity more in the cultural incompatibility condition, and this effect was confined to those who initially presented an integrated (or bicultural) identity. Mortality salience led to monoculturalism striving when bicultural participants considered incompatible aspects of both their cultures, hence verifying the importance of upholding a strong and unwavering cultural worldview to cope with death awareness. The role of death-thoughts accessibility and religious attitudes following participants’ efforts to shore up their cultural worldview is discussed.
Temperament and Coping Activity Under Stress of Changing Intensity Over Time
Authors: Heszen Irena
Published: May 2012

Temperament is probably an important factor that influences coping activity. The framework of the study was the Regulative Theory of Temperament by Strelau, where six temperamental traits are distinguished: emotional reactivity, perseveration, activity, briskness, sensory sensitivity, and endurance. These traits were hypothesized to be connected to coping activity in accordance with their psychological characteristics. It was also expected that the associations between temperament and coping activity should depend on stress intensity. Participants were 278 diabetics and 232 patients after first myocardial infarction (MI). The study was longitudinal and two diseases had been purposely selected so as to represent stress intensity either increasing (in diabetes) or decreasing (after MI) over time. Temperamental traits as well as coping activity components: cognitive appraisal, affect, and coping strategies were measured using self-report questionnaires. As hypothesized, temperamental traits were connected to coping activity. Phase-related changes in coping activity confirmed an increase in stress levels in diabetics, while cardiac patients tended to experience the situation as more challenging. While the expectation referring to the differential role of temperament under different levels of stress intensity was not confirmed, the connections of temperament with coping activity were found to decrease under long-term stress.
Autocorrelation characteristics of surface ocean pCO2and air‐sea CO2 fluxes
Authors: Jones S. D. , Le Quéré C. , Rödenbeck C.
Published: May 2012

Understanding the variability and coherence of surface ocean pCO2 on a global scale can provide insights into its physical and biogeochemical drivers and inform future samplings strategies and data assimilation methods. We present temporal and spatial autocorrelation analyses of surface ocean pCO2on a 5° × 5° grid using the Lamont‐Doherty Earth Observatory database. The seasonal cycle is robust with an interannual autocorrelation of ∼0.4 across multiple years. The global median spatial autocorrelation (e‐folding) length is 400 ± 250 km, with large variability across different regions. Autocorrelation lengths of up to 3,000 km are found along major currents and basin gyres while autocorrelation lengths as low as 50 km are found in coastal regions and other areas of physical turbulence. Zonal (east–west) autocorrelation lengths are typically longer than their meridional counterparts, reflecting the zonal nature of many major ocean features. Uncertainties in spatial autocorrelation in different ocean basins are between 42% and 73% of the calculated decorrelation length. The spatial autocorrelation length in air‐sea fluxes is much shorter than forpCO2 (200 ± 150 km) due to the high variability of the gas transfer velocity.
Energetic electron fluxes at Saturn from Cassini observations
Authors: Tang Rongxin , Summers Danny
Published: May 2012

Energetic electron fluxes (18 keV–21 MeV) observed by the MIMI/LEMMS instrument on the Cassini mission during 2004 to 2008 are analyzed. We consider all 101 orbits and we select portions of the orbits that lie within 0.5 RS of the magnetic equatorial plane, where RS is Saturn's radius. We determine the average electron differential flux and integral flux at specified L‐shells in the range 4.5 < L < 11. Further, comparisons are made between the observed fluxes and the corresponding relativistic self‐limiting values developed from Kennel‐Petschek theory. We find that at lower L‐shells, L < 5, measured fluxes are much less than limiting values; at intermediate L‐shells, 5 < L < 7, measured fluxes are close to the Kennel‐Petschek limit; and at larger L‐shells, 7 < L < 10, measured fluxes well exceed the limit. This suggests that (1) at lower L‐shells particle injection is relatively weak, (2) at intermediate L‐shells, sufficiently strong particle injections generate whistler mode waves to self‐limit trapped fluxes, and (3) at larger L‐shells, intense particle injections result in trapped particle fluxes well in excess of the Kennel‐Petschek limit.
Correlation as a global measure of geomagnetic activity: Phase boundaries and a precedent line of nodes
Authors: Cosgrove Russell , Sanchez Ennio
Published: May 2012

This work considers the global correlation of geomagnetic activity as a way to evaluate magnetotail disturbances, such as the substorm. Impulsive magnetotail disturbances are generally associated with geomagnetic pulsations, which can be coherent over wide ranges of latitude and longitude, and which display distinctive phase reversals collocated with power maxima. Analyzing a disturbance period chosen for its breadth in local time, we find that pulsations can be detected from the coherence that they generate within a magnetometer array, and identify an extended line of nodes across which the phase reversals occur. Phase reversals consistent with the same line of nodes persist for five hours, beginning clearly in a 0.7 mHz pulsation one and a half hours before the disturbance, and persisting in a 5.8 mHz pulsation three and one half hours after the initial disturbance. Under the hypothesis that the line of nodes maps to a source in the central plasma sheet (CPS), we note that the persistence of this extended source of disturbances suggests memory in the CPS. We define a quantitative “coherence index” that characterizes geomagnetic activity according to the degree of global coherence that it generates, and observe that a narrowly peaked coherence signal leads a much broader peak in power. We relate these results to models of the magnetosphere based in critical phenomena.
Kinetic ballooning/interchange instability in a bent plasma sheet
Authors: Panov E. V. , Nakamura R. , Baumjohann W. , Kubyshkina M. G. , Artemyev A. V. , Sergeev V. A. , Petrukovich A. A. , Angelopoulos V. , Glassmeier K.‐H. , McFadden J. P. , Larson D.
Published: May 2012

We use Time History of Events and Macroscale Interactions during Substorms (THEMIS) and GOES observations to investigate the plasma sheet evolution on 28 February 2008 between 6:50 and 7:50 UT, when there developed strong magnetic field oscillations with periods of 100 s. Using multispacecraft analysis of the plasma sheet observations and an empirical plasma sheet model, we determine both the large‐scale evolution of the plasma sheet and the properties of the oscillations. We found that the oscillations exhibited signatures of kinetic ballooning/interchange instability fingers that developed in a bent current sheet. The interchange oscillations had a sausage structure, propagated duskward at a velocity of about 100 km/s, and were associated with fast radial electron flows. We suggest that the observed negative gradient of the ZGSM magnetic field component (∂BZ/∂X) was a free energy source for the kinetic ballooning/interchange instability. Tens of minutes later a fast elongation of ballooning/interchange fingers was detected between 6 and 16 RE downtail with the length‐to‐width ratio exceeding 20. The finger elongation ended with signatures of reconnection in an embedded current sheet near the bending point. These observations suggest a complex interplay between the midtail and near‐Earth plasma sheet dynamics, involving localized fluctuations in both cross‐tail and radial directions before current sheet reconnection.
Toward an understanding of disequilibrium dihedral angles in mafic rocks
Authors: Holness Marian B. , Humphreys Madeleine C. S. , Sides Rachel , Helz Rosalind T. , Tegner Christian
Published: May 2012

The median dihedral angle at clinopyroxene‐plagioclase‐plagioclase junctions in mafic rocks, Θcpp, is generally lower than equilibrium (109° ± 2°). Observation of a wide range of mafic bodies demonstrates that previous work on systematic variations of Θcpp is incorrect in several important respects. First, the spatial distribution of plagioclase compositional zoning demonstrates that the final geometry of three‐grain junctions, and hence Θcpp, is formed during solidification (the igneous process): sub‐solidus textural modification in most dolerites and gabbros, previously thought to be the dominant control on Θcpp, is insignificant. Θcpp is governed by mass transport constraints, the inhibiting effects of small pore size on crystallization, and variation in relative growth rates of pyroxene and plagioclase. During rapid cooling, pyroxene preferentially fills wider pores while the narrower pores remain melt‐filled, resulting in an initial value of Θcpp of 78°, rather than 60° which would be expected if all melt‐filled pores were filled with pyroxene. Lower cooling rates create a higher initial Θcpp due to changes in relative growth rates of the two minerals at the nascent three‐grain junction. Low Θcpp (associated with cuspate clinopyroxene grains at triple junctions) can also be diagnostic of infiltration of previously melt‐free rocks by late‐stage evolved liquids (the metasomatic process). Modification of Θcpp by sub‐solidus textural equilibration (the metamorphic process) is only important for fine‐grained mafic rocks such as chilled margins and intraplutonic chill zones. In coarse‐grained gabbros from shallow crustal intrusions the metamorphic process occurs only in the centers of oikocrysts, associated with rounding of chadacrysts.
Geoengineering: Whiter skies?
Authors: Kravitz Ben , MacMartin Douglas G. , Caldeira Ken
Published: May 2012

One proposed side effect of geoengineering with stratospheric sulfate aerosols is sky whitening during the day and afterglows near sunset, as is seen after large volcanic eruptions. Sulfate aerosols in the stratosphere would increase diffuse light received at the surface, but with a non‐uniform spectral distribution. We use a radiative transfer model to calculate spectral irradiance for idealized size distributions of sulfate aerosols. A 2% reduction in total irradiance, approximately enough to offset anthropogenic warming for a doubling of CO2 concentrations, brightens the sky (increase in diffuse light) by 3 to 5 times, depending on the aerosol size distribution. The relative increase is less when optically thin cirrus clouds are included in our simulations. Particles with small radii have little influence on the shape of the spectra. Particles of radius ∼0.5 μm preferentially increase diffuse irradiance in red wavelengths, whereas large particles (∼0.9 μm) preferentially increase diffuse irradiance in blue wavelengths. Spectra show little change in dominant wavelength, indicating little change in sky hue, but all particle size distributions produce an increase in white light relative to clear sky conditions. Diffuse sky spectra in our simulations of geoengineering with stratospheric aerosols are similar to those of average conditions in urban areas today.
Introduction to special section on Recent Advances in the Study of Optical Variability in the Near‐Surface and Upper Ocean
Authors: Dickey T. , Banner M. L. , Bhandari P. , Boyd T. , Carvalho L. , Chang G. , Chao Y. , Czerski H. , Darecki M. , Dong C. , Farmer D. , Freeman S. , Gemmrich J. , Gernez P. , Hall‐Patch N. , Holt B. , Jiang S. , Jones C. , Kattawar G. , LeBel D. , Lenain L. , Lewis M. , Liu Y. , Logan L. , Manov D. , Melville W. K. , Moline M. A. , Morison R. , Nencioli F. , Pegau W. S. , Reineman B. , Robbins I. , Röttgers R. , Schultz H. , Shen L. , Shinki M. , Slivkoff M. , Sokólski M. , Spada F. , Statom N. , Stramski D. , Sutherland P. , Twardowski M. , Vagle S. , Van Dommelen R. , Voss K. , Washburn L. , Wei J. , Wijesekera H. , Wurl O. , Yang D. , Yildiz S. , You Y. , Yue D. K. P. , Zaneveld R. , Zappa C. J.
Published: May 2012

Optical variability occurs in the near‐surface and upper ocean on very short time and space scales (e.g., milliseconds and millimeters and less) as well as greater scales. This variability is caused by solar, meteorological, and other physical forcing as well as biological and chemical processes that affect optical properties and their distributions, which in turn control the propagation of light across the air‐sea interface and within the upper ocean. Recent developments in several technologies and modeling capabilities have enabled the investigation of a variety of fundamental and applied problems related to upper ocean physics, chemistry, and light propagation and utilization in the dynamic near‐surface ocean. The purpose here is to provide background for and an introduction to a collection of papers devoted to new technologies and observational results as well as model simulations, which are facilitating new insights into optical variability and light propagation in the ocean as they are affected by changing atmospheric and oceanic conditions.
The anomalous structures of atmospheric and oceanic variables associated with the frequency of North Pacific winter blocking
Authors: You Jae‐Eun , Ahn Joong‐Bae
Published: May 2012

From Empirical Orthogonal Function (EOF) analysis of the atmospheric and oceanic variables over the North Pacific during the northern hemispheric winter (1960–2009), we were able to determine that the second mode of the EOF is related to North Pacific winter blocking. Our composite analysis reveals that the structures of the variables during winters with contrasting frequencies of blocking events are systematically different and show quite opposite pattern in the North Pacific. During winters with frequent blocking occurrence, a north–south dipole pattern of geopotential height anomaly is formed, and the associated westerly winds are weakened (strengthen) north (south) of 35°N. These factors bring variations of ocean advection and ocean surface heat flux, resulting in a dipole pattern of Sea Surface Temperature (SST), with a warm anomaly north of 35°N and a cold anomaly to the south. The effect of SST on blocking is examined using an Atmospheric General Circulation Model (AGCM) experiment. In the experiment, the SST anomaly related to blocking is applied as a boundary forcing of the AGCM to investigate the effect of SST on the formation of blocking. From the experiment, we also concluded that the winter blocking is not induced by North Pacific SST forcing, although consistent linkage between oceanic and atmospheric variables is evident.
The neglected genome
Authors: Pesole Graziano , Allen John F , Lane Nick , Martin William , Rand David M , Schatz Gottfried , Saccone Cecilia
Published: May 2012

The mitochondrial genome, though tiny, is vital to life. Modern high‐throughput investigations should pay closer attention to this minute genetic treasure trove.
SUMOylation of Blimp‐1 is critical for plasma cell differentiation
Authors: Ying Hsia‐Yuan , Su Shin‐Tang , Hsu Pang‐Hung , Chang Che‐Chang , Lin I‐Ying , Tseng Yu‐Hsuan , Tsai Ming‐Daw , Shih Hsiu‐Ming , Lin Kuo‐I
Published: May 2012

Transcriptional repressor B lymphocyte‐induced maturation protein‐1 (Blimp‐1) is a master regulator of plasma cell differentiation. Here we show that Blimp‐1 is covalently modified by SUMO1 at lysine 816, a modification mediated by SUMO E3 ligase PIAS1. Mutation of Blimp‐1 lysine 816 reduces transcriptional repression—correlating with a reduced interaction with a histone deacetylase, HDAC2—and impairs differentiation of antibody‐secreting cells. Thus, the SUMO pathway critically regulates Blimp‐1 function during plasma cell differentiation.
Mysterious Ca2+-independent muscular contraction: déjà vu
Authors: Kuznetsov Andrey V. , Guzun Rita , Boucher François , Bagur Rafaela , Kaambre Tuuli , Saks Valdur
Published: May 2012

The permeabilized cells and muscle fibres technique allows one to study the functional properties of mitochondria without their isolation, thus preserving all of the contacts with cellular structures, mostly the cytoskeleton, to study the whole mitochondrial population in the cell in their natural surroundings and it is increasingly being used in both experimental and clinical studies. The functional parameters (affinity for ADP in regulation of respiration) of mitochondria in permeabilized myocytes or myocardial fibres are very different from those in isolated mitochondria in vitro. In the present study, we have analysed the data showing the dependence of this parameter upon the muscle contractile state. Most remarkable is the effect of recently described Ca2+-independent contraction of permeabilized muscle fibres induced by elevated temperatures (30–37°C). We show that very similar strong spontaneous Ca2+-independent contraction can be produced by proteolytic treatment of permeabilized muscle fibres that result in a disorganization of mitochondrial arrangement, leading to a significant increase in affinity for ADP. These data show that Ca2+-insensitive contraction may be related to the destruction of cytoskeleton structures by intracellular proteases. Therefore the use of their inhibitors is strongly advised at the permeabilization step with careful washing of fibres or cells afterwards. A possible physiologically relevant relationship between Ca2+-regulated ATP-dependent contraction and mitochondrial functional parameters is also discussed.
α-Scale decoupling of the mechanical relaxation and diverging shear wave propagation length scale in triphenylphosphite
Authors: Torchinsky Darius H. , Johnson Jeremy A. , Nelson Keith A.
Published: May 2012

We have performed depolarized impulsive stimulated scattering experiments to observe shear acoustic phonons in supercooled triphenylphosphite (TPP) from ∼10–500 MHz. These measurements, in tandem with previously performed longitudinal and shear measurements, permit further analyses of the relaxation dynamics of TPP within the framework of the mode coupling theory. Our results provide evidence of α coupling between the shear and longitudinal degrees of freedom up to a decoupling temperature Tc = 231 K. A lower bound length scale of shear wave propagation in liquids verified the exponent predicted by theory in the vicinity of the decoupling temperature.
An analytical study of the pulsed thermography defect detection limit
Authors: Almond D. P. , Pickering S. G.
Published: May 2012

A simple modification of the one-dimensional expression for the thermal contrast of a layer provides a useful prediction of peak contrast temperature and contrast peak time for defects of all aspect ratios. The new analytical results have been shown to agree with numerical modelling. The thermographic nondestructive evaluation (NDE) rule-of-thumb that defects are detected if aspect ratio exceeds two is shown to have no general validity as peak contrast is found to depend critically on defect depth and absorbed excitation energy as well as defect aspect ratio. The effects of thermal diffusivity anisotropy are included in the analysis and illustrated by simulations of defect image contrast in composite materials.
Scaling relations and the role of bond-charge to the electron transmission through two coupled Aharonov-Bohm rings
Authors: Wu C. H. , Tran L. , Cain C. A.
Published: May 2012

Electron transport and the exact scaling relations for two irreducibly coupled Aharonov-Bohm (AB) rings with two external terminals attached are investigated. In coupled AB rings, a center common path exists where the phase of the electron wave function can be modulated by two applied fluxes simultaneously. The two coupled rings can be considered as two coupled atoms where Fermi level crossings exist not only between bonding states but also between bonding and anti-bonding states when the applied flux is varied in one of the two cases studied. We show that when the smallest atomic-sized coupled rings are scaled up any odd number of times, an identical electron transmission is preserved. When two terminals are attached to isolated coupled AB rings, there is a further redistribution of bond-charge stored within the center common path. The shift of the electron charge distribution to favor one end of the common path is accompanied by the redistribution of the two partial waves that traverse through the two arms from the input to the output terminal. The flux can control which arm the electron traverses through more favorably, and hence, the center path behaves like a flux-controlled charge reservoir for the electron transport. The unbalanced charge in the entire structure creates a space-charge effect much like a p-n junction. The paradox of the delocalization of the electron wave when two AB rings are coupled and the subsequent localization effect of the electron transport in a quantum network are described.
Factorization method in scalar field on AdS3 in spherical coordinates
Authors: Sadeghi J. , Rostami M.
Published: May 2012

In this paper, we reformulate free scalar field on AdS3 with spherical coordinates. The suitable coordinates lead us to obtain the action for the massless free particle. This action admits to apply the variable separation and obtains the corresponding second order equation. So, we factorize this equation with respect to n and m and obtain the wave function and energy spectrum. In order to have the shape invariance condition, we show that the corresponding Hamiltonian must be factorized just in terms of m. This leads us to study the partner potential and super potential. Finally, we discuss the commutation relation between supercharge and corresponding Hamiltonian, which shows that the first order operators will be a form of generators algebra.
Van der Waals interactions in solids using the exchange-hole dipole moment model
Authors: Otero-de-la-Roza A. , Johnson Erin R.
Published: May 2012

The exchange-hole dipole moment model of dispersion interactions of Becke and Johnson [J. Chem. Phys. 127 154108 (2007)10.1063/1.2795701] is implemented for calculations in solids using the pseudopotentials/plane-waves approach. The resulting functional retains the simplicity and efficiency of semilocal functionals while accurately treating dispersion interactions via a semiempirical asymptotic expansion. The dispersion coefficients are calculated completely ab initio using local quantities alone (density, gradient, Laplacian, and kinetic energy density). The two empirical parameters in the damping function are calculated by fit to a 65-molecule training set recalculated under periodic boundary conditions. Calculations in simple solids offer good results with minimal computational cost compared to electronic relaxation.
Buckled colloidal crystals with nonspherical bases for two-dimensional slab photonic band gaps
Authors: Riley E. K. , Fung E. Y. , Watson C. M. Liddell
Published: May 2012

Theoretical modeling of the photonic band gap forming properties is reported for the buckled phase of anisotropic particles. These exist between the first and second particulate layers of confined colloidal suspensions. Inspired by the range of non-spherical mushroom-cap building blocks for self-assembly that have been synthesized using seeded emulsion-polymerization, we explore in particular the band structures as a function of toroid shape parameter. The parameter is adjusted to incrementally transform hemispheres to spheres. Additionally, corrugation heights that systematically modulate the slab photonic crystal unit cell from rectangular monolayer to square bilayer are investigated. Polarization independent gaps in the guided modes are determined for direct and inverted structures that exhibit bifurcation in the particle orientation perpendicular to the slab plane. Gaps in the guided modes are observed between the fourth and fifth, twelfth and thirteenth, as well as higher band locales as the particle morphology and lattice aspect ratio vary.
Dissipative geometric phase and decoherence in parity-violating chiral molecules
Authors: Dorta-Urra A. , Peñate-Rodríguez H. C. , Bargueño P. , Rojas-Lorenzo G. , Miret-Artés S.
Published: May 2012

Within a generalized Langevin framework for open quantum systems, the cyclic evolution of a two-level system is analyzed in terms of the geometric phase extended to dissipative systems for Ohmic friction. This proposal is applied to the dynamics of chiral molecules where the tunneling and parity violating effects are competing. The effect of different system-bath coupling functions in the dissipated energy is shown to be crucial to understand the behavior of the geometric phase as well as the decoherence displayed by the corresponding interference patterns.
Synthesis and evolution of magnetic properties of Ni doped La2/3Sr1/3Mn1−xNixO3 nanoparticles
Authors: Gupta Maneesha , Khan Wasi , Yadav Poonam , Kotnala R. K. , Azam A. , Naqvi A. H.
Published: May 2012

A systematic investigation of the structural and magnetic properties of La2/3Sr1/3Mn1−xNixO3 (x = 0%, 5%, 15%, and 25%) perovskite nanoparticles synthesized using mild sol-gel technique is reported. These samples were characterized using x-ray diffraction (XRD), transmission electron microscopy, Fourier transform infrared (FTIR) spectroscopy, and temperature dependent magnetoresistance (MR) measurements. XRD analysis confirmed the single phase nature of the samples, and crystallite size was found to decrease from 21.4 nm to 17.0 nm with the increase in Ni concentration. Further, maximum MR was observed for 25% Ni doped sample at low temperature (77 K), whereas at room temperature (300 K) MR decreases with increase in Ni concentration. FTIR spectra show a broad peak at 605.28 cm−1, giving an evidence for the formation of metal oxygen bond which subsequently organize into a MnO6 octahedral structure as evidenced by the appearance of a well defined spectral band. Room temperature magnetization for all samples reduces with Ni doping and it is highest for 5% doped sample. The results have been explained on the basis of destruction of the partial double-exchange interactions and the exchange couplings between Mn and doped ions.
Electronic detection of dielectrophoretic forces exerted on particles flowing over interdigitated electrodes
Authors: Nikolic-Jaric Marija , Romanuik Sean F. , Ferrier Graham A. , Cabel Tim , Salimi Elham , Levin David B. , Bridges Greg E. , Thomson Douglas J.
Published: May 2012

Dielectric particles flowing through a microfluidic channel over a set of coplanar electrodes can be simultaneously capacitively detected and dielectrophoretically (DEP) actuated when the high (1.45 GHz) and low (100 kHz–20 MHz) frequency electromagnetic fields are concurrently applied through the same set of electrodes. Assuming a simple model in which the only forces acting upon the particles are apparent gravity, hydrodynamic lift, DEP force, and fluid drag, actuated particle trajectories can be obtained as numerical solutions of the equations of motion. Numerically calculated changes of particle elevations resulting from the actuation simulated in this way agree with the corresponding elevation changes estimated from the electronic signatures generated by the experimentally actuated particles. This verifies the model and confirms the correlation between the DEP force and the electronic signature profile. It follows that the electronic signatures can be used to quantify the actuation that the dielectric particle experiences as it traverses the electrode region. Using this principle, particles with different dielectric properties can be effectively identified based exclusively on their signature profile. This approach was used to differentiate viable from non-viable yeast cells (Saccharomyces cerevisiae).
Slip band distribution in rapid thermally annealed silicon wafers
Authors: Garagorri Jorge , Reyes Elizalde M. , Fossati Matteo C. , Jacques David , Tanner Brian K.
Published: May 2012

X-ray diffraction imaging of 200 mm diameter (100) oriented double-side polished silicon wafers has revealed that the slip band distribution, following rapid thermal annealing (RTA), has a lower symmetry than predicted from the material crystallography. Finite element (FE) modelling of the thermal processes has been undertaken and it is found that, in order to predict the measured temperature distribution during the annealing sequence in a commercial RTA furnace, an anisotropic heat flux distribution in the furnace must be included. When such an anisotropic heat flux is used to predict the wafer temperature, it is found that the temperature gradients are not equivalent in the radial direction. Calculation of the resolved shear stresses on the five independent slip systems associated with these gradients predicts asymmetry between the stress on slip bands that project into the [011] and [01¯1] directions. The anisotropy of the resolved shear stress distribution predicts accurately the asymmetry of the experimentally observed slip band length and density. Rotation of the wafer with respect to the furnace axes results in characteristic and systematic changes in the symmetry of the distribution, which is in good agreement with the finite element predictions.
A simulation study of magnetic force effects on solution flow during protein crystal growth
Authors: Okada H. , Hirota N. , Matsumoto S. , Wada H.
Published: May 2012

We are developing a superconducting magnet system for growing high-quality protein crystals from solutions in a reduced gravity environment by magnetic force. In order to estimate a suitable reduced gravity environment by magnetic force for protein crystal growth, we propose a flow simulation model that elucidates the motion of multicomponent solutions under magnetic force. The simulation model is based on the Navier-Stokes equation and is applied to analyzing effects of different factors on the fluid flow in protein solutions. Numerical calculation results indicate that magnetic force strongly influences the protein solution flow through magnetic susceptibility distribution in fluid.