bluuebunny/crossref_metadata_2025 huggingface dataset:
Artifact reduction from metallic dental materials in T1‐weighted spin‐echo imaging at 3.0 tesla
Authors: Zho Sang‐Young , Kim Min‐Oh , Lee Keun‐Woo , Kim Dong‐Hyun
Published: September 2012

Purpose:

To investigate and propose a method of artifact reduction arising from metallic dental materials by applying a slice‐encoding for metal artifact correction (SEMAC) technique on T1‐weighted spin‐echo (SE) imaging at 3 Tesla.

Materials and Methods:

The view angle tilting (VAT) technique was adapted to conventional T1‐weighted spin‐echo (SE) sequence to correct the in‐plane distortion, and the SEMAC technique was used for correcting the remaining through‐plane distortions. Fourier transform based B0 field simulations were performed to estimate the amount of field perturbation and a scout imaging method was developed which guide in selecting the number of slice‐encodings needed in SEMAC sequences. Phantoms of six different dental materials with various shapes and sizes that are used in practice (amalgam; titanium implant; gold and Ni‐Cr crowns; Ni‐Ti and stainless steel orthodontic wires) were imaged. In vivo images of two subjects were also acquired. The amounts of artifact reduction were quantified in phantom studies.

Results:

Compared with conventional SE imaging in phantom studies, in‐plane artifacts were reduced by up to 43% in the VAT SE images and 80% in the SEMAC images. Through‐plane artifacts were reduced by up to 65% in SEMAC images. In vivo SEMAC images also showed reduced artifacts.

Conclusion:

The SEMAC technique can mitigate artifact caused by metallic dental materials for T1w‐SE imaging. J. Magn. Reson. Imaging 2013;37:471–478. © 2012 Wiley Periodicals, Inc.
Asymptomatic prospective and retrospective cohorts with metal‐on‐metal hip arthroplasty indicate acquired lymphocyte reactivity varies with metal ion levels on a group basis
Authors: Hallab Nadim J. , Caicedo Marco , McAllister Kyron , Skipor Anastasia , Amstutz Harlan , Jacobs Joshua J.
Published: September 2012

Some tissues from metal‐on‐metal (MoM) hip arthroplasty revisions have shown evidence of adaptive‐immune reactivity (i.e., excessive peri‐implant lymphocyte infiltration/activation). We hypothesized that, prior to symptoms, some people with MoM hip arthroplasty will develop quantifiable metal‐induced lymphocyte reactivity responses related to peripheral metal ion levels. We tested three cohorts (Group 1: n = 21 prospective longitudinal MoM hip arthroplasty; Group 2: n = 17 retrospective MoM hip arthroplasty; and Group 3: n = 20 controls without implants). We compared implant position, metal‐ion release, and immuno‐reactivity. MoM cohorts had elevated (p < 0.01) amounts of serum Co and Cr compared to controls as early as 3 months post‐op (Group 1:1.2 ppb Co, 1.5 ppb Cr; Group 2: 3.4 ppb Co, 5.4 ppb Cr; Group 3: 0.01 ppb Co, 0.1 ppb Cr). However, only after 1–4 years post‐op did 56% of Group 1 develop metal‐reactivity (vs. 5% pre‐op, metal‐LTT, SI > 2), compared with 76% of Group 2, and 15% of Group 3 controls (patch testing was a poor diagnostic indicator with only 1/21 Group 1 positive). Higher cup‐abduction angles (50° vs. 40°) in Group 1 were associated with higher serum Cr (p < 0.07). However, sub‐optimal cup‐anteversion angles (9° vs. 20°) had higher serum Co (p < 0.08). Serum Cr and Co were significantly elevated in reactive versus non‐reactive Group‐1 participants (p < 0.04). CD4+CD69+ T‐helper lymphocytes (but not CD8+) and IL‐1β, IL‐12, and IL‐6 cytokines were all significantly elevated in metal‐reactive versus non‐reactive Group 1 participants. Our results showed that lymphocyte reactivity to metals can develop within the first 1–4 years after MoM arthroplasty in asymptomatic patients and lags increases in metal ion levels. This increased metal reactivity was more prevalent in those individuals with extreme cup angles and higher amounts of circulating metal. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 173–182, 2013
Reusable plasmonic substrates fabricated by interference lithography: a platform for systematic sensing studies
Authors: Siegfried Thomas , Kind Martin , Terfort Andreas , Martin Olivier J. F. , Zharnikov Michael , Ballav Nirmalya , Sigg Hans
Published: September 2012

Surface‐enhanced Raman scattering (SERS) has become increasingly popular in the scientific and industrial communities because of its analytical capabilities and potential to study fundamentals in plasmonics. Although under certain conditions extremely high sensitivity is possible, the practical use of SERS is frequently limited by instability and poor reproducibility of the enhancement factor. For analytical applications or for comparative measurements to enable the distinction between electromagnetic and chemical enhancement, the development of standardized and recyclable SERS substrates, having uniform and persistent performance, is proposed. To this end, we have fabricated periodic nanoslit arrays using extreme ultraviolet lithography that provide average large (2*106) and homogeneous SERS enhancement factors with a spot‐to‐spot variability of less than 3%. In addition, they are reusable without any degradation or loss of enhancement. The fabrication of such arrays consists of two steps only, lithographic patterning followed by metal evaporation. Both processes may be performed over areas of several square mm on any planar substrate. The sensor capabilities were demonstrated by substrates with monomolecular films of several different thiols. The concept of reusable SERS substrates may open a powerful platform within an analytical tool and in particular for systematic SERS studies for the investigation of fundamental parameters such as chemical enhancement, surface selection rules, and molecular alignment. Copyright © 2012 John Wiley & Sons, Ltd.
A consistent model for the thermal decomposition of NCN3 and the singlet– triplet relaxation of NCN
Authors: Dammeier J. , Oden B. , Friedrichs G.
Published: September 2012

The thermal decomposition of cyanogen azide (NCN3) and the subsequent collision‐induced intersystem crossing (CIISC) process of cyanonitrene (NCN) have been investigated by monitoring excited electronic state 1NCN and ground state 3NCN radicals. NCN was generated by the pyrolysis of NCN3 behind shock waves and by the photolysis of NCN3 at room temperature. Falloff rate constants of the thermal unimolecular decomposition of NCN3 in argon have been extracted from 1NCN concentration–time profiles in the temperature range 617 K <T< 927 K and at two different total densities: k(ρ ≈ 3 × 10−6 mol/cm3)/s−1=4.9 × 109 × exp (−71±14 kJ mol−1/RT) (± 30%); k(ρ ≈ 6 × 10−6 mol/cm3)/s−1=7.5 × 109 × exp (‐71±14 kJ mol−1/RT) (± 30%). In addition, high‐temperature 1NCN absorption cross sections have been determined in the temperature range 618 K <T< 1231 K and can be expressed by σ /(cm2/mol)= 1.0 × 108 −6.3 × 104 K−1 × T (± 50%). Rate constants for the CIISC process have been measured by monitoring 3NCN in the temperature range 701 K <T< 1256 K resulting in kCIISC (ρ ≈ 1.8 ×10−6 mol/cm3)/ s−1=2.6 × 106× exp (‐36±10 kJ mol−1/RT) (± 20%), kCIISC (ρ ≈ 3.5×10−6 mol/cm3)/ s−1 = 2.0 × 106 × exp (−31±10 kJ mol−1/RT) (± 20%), kCIISC (ρ ≈ 7.0×10−6 mol/cm3)/ s−1=1.4 × 106 × exp (−25±10 kJ mol−1/RT) (± 20%). These values are in good agreement with CIISC rate constants extracted from corresponding 1NCN measurements. The observed nonlinear pressure dependences reveal a pressure saturation effect of the CIISC process. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 45: 30–40, 2013
Evidence for the involvement of the anthranilate degradation pathway in Pseudomonas aeruginosa biofilm formation
Authors: Costaglioli Patricia , Barthe Christophe , Claverol Stephane , Brözel Volker S. , Perrot Michel , Crouzet Marc , Bonneu Marc , Garbay Bertrand , Vilain Sebastien
Published: September 2012

Bacterial biofilms are complex cell communities found attached to surfaces and surrounded by an extracellular matrix composed of exopolysaccharides, DNA, and proteins. We investigated the whole‐genome expression profile of Pseudomonas aeruginosa sessile cells (SCs) present in biofilms developed on a glass wool substratum. The transcriptome and proteome of SCs were compared with those of planktonic cell cultures. Principal component analysis revealed a biofilm‐specific gene expression profile. Our study highlighted the overexpression of genes controlling the anthranilate degradation pathway in the SCs grown on glass wool for 24 h. In this condition, the metabolic pathway that uses anthranilate for Pseudomonas quinolone signal production was not activated, which suggested that anthranilate was primarily being consumed for energy metabolism. Transposon mutants defective for anthranilate degradation were analyzed in a simple assay of biofilm formation. The phenotypic analyses confirmed that P. aeruginosa biofilm formation partially depended on the activity of the anthranilate degradation pathway. This work points to a new feature concerning anthranilate metabolism in P. aeruginosa SCs.
Diagnosis of osteoarthritis and prognosis of tibial cartilage loss by quantification of tibia trabecular bone from MRI
Authors: Marques Joselene , Genant Harry K. , Lillholm Martin , Dam Erik B.
Published: September 2012

A longitudinal study was used to investigate the quantification of osteoarthritis and prediction of tibial cartilage loss by analysis of the tibia trabecular bone from magnetic resonance images of knees. The Kellgren Lawrence (KL) grades were determined by radiologists and the levels of cartilage loss were assessed by a segmentation process. Aiming to quantify and potentially capture the structure of the trabecular bone anatomy, a machine learning approach used a set of texture features for training a classifier to recognize the trabecular bone of a knee with radiographic osteoarthritis. Using cross‐validation, the bone structure marker was used to estimate for each knee both the probability of having radiographic osteoarthritis (KL >1) and the probability of rapid cartilage volume loss. The diagnostic ability reached a median area under the receiver‐operator‐characteristics curve of 0.92 (P < 0.0001), and the prognosis had odds ratio of 3.9 (95% confidence interval: 2.4–6.5). The medians of cartilage loss of the subjects classified as slow and rapid progressors were 1.1% and 4.9% per year, respectively. A preliminary radiological reading of the high and low risk knees put forward an hypothesis of which pathologies the bone marker could be capturing to define the prognosis of cartilage loss. Magn Reson Med 70:568–575, 2013. © 2012 Wiley Periodicals, Inc.
The Expected Impact of State Immigration Legislation on Labor Market Outcomes
Authors: Hotchkiss Julie L. , Quispe‐Agnoli Myriam
Published: September 2012

In response to the dramatic rise in the number of unauthorized immigrants to the United States, every state has passed some form of immigration legislation. These laws appear to be predicated on a belief that unauthorized immigrants impose greater costs than benefits to state and local communities, including the labor market. The purpose of this paper is to examine some evidence on what workers should expect if the immigration legislation is successful in eliminating undocumented workers from states' labor markets. © 2012 by the Association for Public Policy Analysis and Management.
Sensitivity of polyvinylidene fluoride films to mechanical vibration modes and impact after optimizing stretching conditions
Authors: Jain Anjana , Kumar Jayanth S. , Srikanth S. , Rathod V.T. , Roy Mahapatra D.
Published: September 2012

The β‐phase of polyvinylidene fluoride (PVDF) is well known for its piezoelectric properties. PVDF films have been developed using solvent cast method. The films thus produced are in α‐phase. The α‐phase is transformed to piezoelectric β‐phase when the film is hot‐stretched with various different stretching factors at various different temperatures. The films are then characterized in terms of their mechanical properties and surface morphological changes during the transformation from α‐ to β‐phases by using X‐ray diffraction, differential scanning calorimeter, Raman spectra, Infrared spectra, tensile testing, and scanning electron microscopy. The films showed increased crystallinity with stretching at temperature up to 80°C. The optimum conditions to achieve β‐phase have been discussed in detail. The fabricated PVDF sensors have been tested for free vibration and impact on plate structure, and its response is compared with conventional piezoelectric wafer type sensor. The resonant and antiresonant peaks in the frequency response of PVDF sensor match well with that of lead zirconate titanate wafer sensors. Effective piezoelectric properties and the variations in the frequency response spectra due to free vibration and impact loading conditions are reported. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers
Characterisation of (E)‐2‐styrylchromones by electrospray ionisation mass spectrometry: singular gas‐phase formation of benzoxanthenones
Authors: Silva Eduarda M. P. , Domingues M. Rosário M. , Silva Artur M. S. , Cavaleiro José A. S.
Published: September 2012

RATIONALE

The electrospray ionisation (ESI) mass spectra (ESI‐MSn, n = 2 and 3) of six (E)‐2‐styrylchromones containing electron‐donating and electron‐withdrawing groups were studied for the first time. The potential application of these compounds as drug candidates brings a need for the development of an analytical method to ensure a detailed knowledge of their structures.

METHODS

ESI‐MS, CID‐MS2 and MS3 spectra of all the studied compounds were acquired using a LXQ linear ion trap mass spectrometer with an electrospray source, operating in the positive ion mode. ESI conditions were: nitrogen 8.00 sheath gas flow rate (arb), spray voltage 5 kV, heated capillary temperature 275 °C, capillary voltage 10.99 V and tube lens voltage 75.01 V. CID‐MS2 and MS3 experiments were performed on mass‐selected precursor ions using standard isolation and excitation procedures (activation q value of 0.25, activation time of 30 ms).

RESULTS

A comparable pattern of product ions was observed for all the studied compounds. Only the product ion (1,2)(3,4)A+ is common to all the studied compounds. Common to compounds 1 (R2 = H), 1a (R2 = OMe) and 1c (R2 = Cl) are the product ions formed by loss of H2O, CO, C6H5OH, and the product ions (1,2)(2,3)B+ and (1,2)(3,4)B+. Among all compounds, 2‐SC 1b (R2 = NO2) shows an obvious differentiation showing the lowest number of product ions under CID‐MS2 conditions.

CONCLUSIONS

The analysed compounds revealed a comparable pattern of product ions formed for each compound only different in what concerns the relative abundance of these formed product ions. A rather interesting and unexpected loss of 2 Da was observed for some compounds. The structure of a benzoxanthenone was proposed for this product ion based on evidence obtained by synthesised benzoxanthenone as a model compound. Copyright © 2012 John Wiley & Sons, Ltd.
Site‐specific deamidation of glutamine: a new marker of bone collagen deterioration
Authors: van Doorn Nienke L. , Wilson Julie , Hollund Hege , Soressi Marie , Collins Matthew J.
Published: September 2012

RATIONALE

Non‐enzymatic deamidation accumulates in aging tissues in vivo and has been proposed to be potentially useful as a molecular clock. The process continues post mortem, and here we explore the increase in levels of deamidation in archaeological collagen, as measured during Zooarchaeology by Mass Spectrometry (ZooMS) analysis.

METHODS

With the high sensitivity of current generation mass spectrometers, ZooMS provides a non‐destructive and highly cost‐effective method to characterise collagen peptides. Deamidation can be detected by mass spectrometry as a +0.984 Da mass shift; therefore, aside from its original purpose, peptide mass‐fingerprinting for bone identification, ZooMS concurrently yields a 'thermal indicator' of the samples.

RESULTS

By analysis of conventional ZooMS spectra, we determined the deamidation rate for glutamine residues in 911 bone collagen samples from 50 sites, with ages varying from medieval to Palaeolithic. The degree of deamidation was compared to diagenetic parameters and nearby sequence properties.

CONCLUSIONS

The extent of deamidation was found to be influenced more by burial conditions and thermal age than, for example, chronological age, the extent of bioerosion or crystallinity. The method lends itself mostly to screening heterogenic deposits of bone to identify outliers. Copyright © 2012 John Wiley & Sons, Ltd.
Development of a Tuned Interfacial Force Field Parameter Set for the Simulation of Protein Adsorption to Silica Glass
Authors: Snyder James A. , Abramyan Tigran , Yancey Jeremy A. , Thyparambil Aby A. , Wei Yang , Stuart Steven J. , Latour Robert A.
Published: September 2012

Adsorption free energies for eight host–guest peptides (TGTG-X-GTGT, with X = N, D, G, K, F, T, W, and V) on two different silica surfaces [quartz (100) and silica glass] were calculated using umbrella sampling and replica exchange molecular dynamics and compared with experimental values determined by atomic force microscopy. Using the CHARMM force field, adsorption free energies were found to be overestimated (i.e., too strongly adsorbing) by about 5–9 kcal/mol compared to the experimental data for both types of silica surfaces. Peptide adsorption behavior for the silica glass surface was then adjusted using a modified version of the CHARMM program, which we call dual force-field CHARMM, which allows separate sets of nonbonded parameters (i.e., partial charge and Lennard-Jones parameters) to be used to represent intra-phase and inter-phase interactions within a given molecular system. Using this program, interfacial force field (IFF) parameters for the peptide-silica glass systems were corrected to obtain adsorption free energies within about 0.5 kcal/mol of their respective experimental values, while IFF tuning for the quartz (100) surface remains for future work. The tuned IFF parameter set for silica glass will subsequently be used for simulations of protein adsorption behavior on silica glass with greater confidence in the balance between relative adsorption affinities of amino acid residues and the aqueous solution for the silica glass surface.
Childhood adversity and psychosis: Examining whether the association is due to genetic confounding using a monozygotic twin differences approach
Authors: Alemany S. , Goldberg X. , van Winkel R. , Gastó C. , Peralta V. , Fañanás L.
Published: September 2012

Purpose

To test whether the association between childhood adversity and positive and negative psychotic experiences is due to genetic confounding.

Method

Childhood adversity and psychotic experiences were assessed in an ongoing sample of 226 twins from the general population. A monozygotic (MZ) twin differences approach was used to assess possible genetic confounding.

Results

In the whole sample, childhood adversity was significantly associated with positive (β = 45; SE = 0.16; P = 0.008) and negative psychotic experiences (β = 0.77; SE = 0.18; P < 0.01). Within-pair MZ twin differences in exposure to childhood adversity were significantly associated with differences in positive (β = 71; SE = 0.29; P = 0.016) and negative psychotic experiences (β = 98; SE = 0.38; P = 0.014) in a subsample of 85 MZ twin pairs.

Conclusions

Individuals exposed to childhood adversity are more likely to report psychotic experiences. Furthermore, our findings indicate that this association is not due to genetic confounding.
Reduced thalamic volume in men with antisocial personality disorder or schizophrenia and a history of serious violence and childhood abuse
Authors: Kumari V. , Gudjonsson G.H. , Raghuvanshi S. , Barkataki I. , Taylor P. , Sumich A. , Das K. , Kuipers E. , Ffytche D.H. , Das M.
Published: September 2012

Objective

Violent behaviour has been associated with presence of certain mental disorders, most notably antisocial personality disorder (ASPD) and schizophrenia, childhood abuse, and multiple brain abnormalities. This study examined for the first time, to the authors’ knowledge, the role of psychosocial deprivation (PSD), including childhood physical and sexual abuse, in structural brain volumes of violent individuals with ASPD or schizophrenia.

Methods

Fifty-six men (26 with ASPD or schizophrenia and a history of serious violence, 30 non-violent) underwent magnetic resonance imaging and were assessed on PSD. Stereological volumetric brain ratings were examined for group differences and their association with PSD ratings. PSD-brain associations were examined further using voxel-based-morphometry.

Results

The findings revealed: reduced thalamic volume in psychosocially-deprived violent individuals, relative to non-deprived violent individuals and healthy controls; negative association between thalamic volume and abuse ratings (physical and sexual) in violent individuals; and trend-level negative associations between PSD and hippocampal and prefrontal volumes in non-violent individuals. The voxel-based-morphometry analysis detected a negative association between PSD and localised grey matter volumes in the left inferior frontal region across all individuals, and additionally in the left middle frontal and precentral gyri in non-violent individuals.

Conclusions

Violent mentally-disordered individuals with PSD, relative to those with no or minimal PSD, suffer from an additional brain deficit, i.e., reduced thalamic volume; this may affect sensory information processing, and have implications for management, of these individuals. PSD may have a stronger relationship with volumetric loss of stress-linked regions, namely the frontal cortex, in non-violent individuals.
Peer and family influence in eating disorders: A meta-analysis
Authors: Quiles Marcos Y. , Quiles Sebastián M.J. , Pamies Aubalat L. , Botella Ausina J. , Treasure J.
Published: September 2012

Objective

The aim of the present study was to undertake a systematic review using meta-analysis procedures to assess the relationships between eating disorders and peer and family influence and to evaluate whether gender plays a moderator role in that relationship.

Method

PsycINFO, Medline, Web of Science, EPSCO and Embase databases from 1980 to 2010 were searched in June and October 2010. Hand searching of relevant reference sections was also undertaken.

Results

It was possible to obtain 83 effect sizes from the 25 studies selected. Results showed that both peers and family influence dieting behavior, body dissatisfaction and bulimic symptoms in adolescent girls and boys. Furthermore, the analyses of the moderator variables showed that the variability of the effect sizes found was, in some cases, explained by gender, influence type and the country of the sample.

Discussion and conclusion

These results highlight how daily social interactions can influence unhealthy eating practices in adolescent girls and boys, and suggest that weight-related issues of parents and peers can be transmitted to adolescents.
Maternal and perinatal outcome in cases of fulminant viral hepatitis in late pregnancy
Authors: Deng Liuzhi , Li Xiaomao , Shi Zhongjie , Jiang Peiru , Chen Dunjin , Ma Lin
Published: September 2012

Objective

To investigate maternal and perinatal outcomes in cases of fulminant viral hepatitis in late pregnancy (FVHILP).

Methods

A multicenter retrospective study was conducted. The records of 40 patients with FVHILP were retrieved from 3 hospitals in China. To analyze the influence of mode of delivery on maternal and perinatal outcomes, women were allocated to the cesarean delivery group or the spontaneous vaginal delivery (SVD) group. To study the relationship between maternal outcome and perinatal outcome, patients were allocated to the maternal survival group or the non‐survival group.

Results

There were no significant differences between the cesarean group and the SVD group in clinical manifestations or laboratory indices before delivery, or in fatality rate (P > 0.05 for all), whereas there were significant differences in newborn weight, 1‐minute Apgar score, and incidence of severe perinatal asphyxia between the maternal survival group and the non‐survival group (P < 0.05 for all).

Conclusion

Maternal and perinatal outcomes in cases of FVHILP were not influenced by mode of delivery, whereas perinatal outcome significantly correlated with maternal outcome.
Twenty years as an independent state: Ukraine’s ten logical inconsistencies
Authors: Kuzio Taras
Published: September 2012

This main focus of the article is an analysis of Ukraine two decades after it became an independent state through ten factors that have remained constant features of Ukrainian life. The first factor is low public trust in state institutions and the wide gulf between elites and state on the one hand and the public on the other. A second factor is the striving by political forces to monopolize political and economic power for the sake of power and self-enrichment – not for the conducting of reforms. The third factor is threats to democracy under eastern Ukrainian Presidents Leonid Kuchma and Viktor Yanukovych. The fourth factor is the low quality and ideological amorphousness of political parties. The fifth factor is the absence of political will and re-occurrence of missed opportunities; a prominent example of which is the Viktor Yushchenko presidency. The sixth factor is the domination of elite greed and rapaciousness over pursuit of the national interest and national security. The most egregious example of this corruption is in the energy sector which western Ukrainians have dominated (It’s a Gas: Funny business in the Turkmen-Ukraine Gas Trade, 2006). A seventh constant factor is the prevalence of virtual over actual policies and the non-fulfillment of domestic obligations which leads to low public trust in state institutions. The eighth factor is an imitation of integration into Euro-Atlantic structures because virtual policies lead to inconsistent and multi-vector foreign policies. Virtual policies make it difficult for European and American governments to engage with the Ukrainian authorities because they rarely fulfill their obligations. The ninth factor is eastern Ukrainian naivety about Russia, regardless of whether it is democratic or authoritarian, that pursues hard-nosed geopolitical goals, a naivety that applies to Kuchma in 1994 as much as to Yanukovych in 2010. The tenth factor, the Russia factor, is Russia’s inability to accept Ukraine’s sovereignty or territorial integrity. Both eastern and western Ukrainian have been unable to fashion responsive policies to deal with Russia’s un-acceptance of Ukraine and its hard-nosed geopolitical goals.
Structural and magnetic microinhomogeneities in accessory spinel of the system Fe2+(Cr2–xFex3+)O4 from the Kytlym massif (Urals platinum-bearing belt)
Authors: Sherendo T.A. , Martyshko P.S. , Moloshag V.P. , Garaeva A.A. , Zamyatin D.A. , Mitrofanov V.Ya. , Pamyatnykh L.A.
Published: September 2012

The microstructure and magnetic properties of accessory Fe–Cr-spinels from the Kytlym massif of the Urals platinum-bearing belt were studied. Atypical Fe–Cr-spinels in the form of magnetic microareas in grains of primary nonmagnetic Fe–Cr-spinel have been revealed for the first time in the bed dunites of the Kytlym multiphase concentrically zoned massif, North Urals. These spinels are responsible for the magnetic properties of the dunites. It has been established that the microareas are separations in solid solution Fe2+(Cr2–xFex3+)O4, which are enriched in Fe3+ and are probably an intermediate product of the transformation of primary accessory Fe-Cr-spinel during the formation of the dunite massif. These are magnetic microphases with particular chemical composition, cation distribution, and corresponding reversed crystal lattice, which determine the main magnetic properties of the microarea: the magnitude and direction of magnetization vector and Curie temperature. The formation of this earlier unknown type of magnetic Fe–Cr-spinel is probably conjugate with the formation and concentration of PGE mineralization in the bed dunites of the Kytlym platinum-bearing massif. The presence of such magnetization carriers in rocks and ores must be taken into account in geophysical research at the Urals chromite and platinum–chromite deposits.
Paleomagnetism of the Cretaceous sediments of the southern West Siberian Plate (from well 8 core studies)
Authors: Gnibidenko Z.N. , Lebedeva N.K. , Shurygin B.N.
Published: September 2012

The paper presents magnetobiostratigraphical data on the Cretaceous sediments stripped by well 8 in the southern side of the Om’ basin within the Om’–Lar’yak facies zone (southern West Siberia). The biostratigraphical data show that the sediments under study formed in the Albian–Maastrichtian. The componential analysis of natural remanent magnetization, based on thermal demagnetization and demagnetization with an alternating magnetic field, revealed the characteristic magnetization component. This confirms the paleomagnetic data used to compile the Cretaceous paleomagnetic section of the well. A paleomagnetic description was obtained, and a magnetobiostratigraphic key section of the Cretaceous sediments of the well was compiled on the basis of comprehensive data. It comprises five Upper Cretaceous regional horizons and same-named formations (Pokur, Kuznetsovo, Ipatovo, Slavgorod, Gan’kino), which have not been studied paleomagnetically at all in West Siberia. The magnetobiostratigraphic section comprises Albian–Maastrichtian stratigraphic units (43.5 Myr) and consists of three magnetozones. For example, the Pokur, Kuznetsovo, and Ipatovo Formations (total thickness 210 m), which show normal polarity with small reversed-magnetization horizons, form one long normal-polarity zone, N(al-st). The Slavgorod and Gan’kino Formations (total thickness 75 m), separated by a sedimentation gap, form two reversed-polarity magnetozones, R1(km) and R2(mt).

Reference datums (paleontologically well-constrained magnetozones) were used to correlate the magnetobiostratigraphic section with the common magnetostratigraphic and magnetochronologic scales. The long normal-polarity magnetozone N(al-st), spanning the Albian, Cenomanian, Turonian, Coniacian, and Santonian, matches the Dzhalal hyperzone and chron C34 (∼ 112–83.6 Ma). The reversed-polarity zones, spanning most of the Campanian (R1(km) (Slavgorod Formation)) and Maastrichtian (R2(mt) (Gan’kino Formation)), match chrons C33(r) and C31(r) in the absolute chronology (∼ 83.6–80 and 71–68.5 Ma, respectively) with a gap two chrons long (C33(n), C32).
Seismic-hazard assessment for Ulaanbaatar (Mongolia) on the basis of seismogeological studies
Authors: Imaev V.S. , Smekalin O.P. , Strom A.L. , Chipizubov A.V. , Syas’ko A.A.
Published: September 2012

The Gunzhin Fault is a tectonic structure in the southern Hentiyn arched uplift (central Mongolia). A fragment of this fault, exposed by two paleoearthquakes, is traced northeastward for ~25 km from the northern periphery of Ulaanbaatar. The first comprehensive seismogeological studies here were aimed at determining the seismic potential of seismogenic structures on the basis of the dislocation parameters. Judging by the strain amplitudes and length, earthquakes with a magnitude of >7.0 might be generated here. The paleoearthquake was dated by the radiocarbon method at 7800–4667 B.C. Seismogenic zones with a high seismic potential were identified in central Mongolia for the first time. Dextral strike-slip faults were observed here among active NE-trending faults, suggesting the presence of E–W compressive stress.
Magneto-seismic studies of the eastern Qattara Depression, Northwestern desert, Egypt
Authors: Rabeh Taha
Published: September 2012

The potential field data are considered the main supporting factor in the geophysical exploration process for detecting and evaluating the subsurface structures. Therefore, a detailed land magnetic survey was performed in an area subjected to seismic investigations. The main target of this study was to detect the deeper subsurface structures and to investigate their possible relationships with earthquake activity.

The RTP aeromagnetic map was used to detect the regional extension of the structures interpreted from the land magnetic survey. The RTP land and aeromagnetic maps were interpreted by the filtering technique, least-squares separations, tectonic trend analysis, spectral analysis, Werner method, Euler method, and 2D techniques. The results show that the main tectonic trends are 35° N–45° W, 45° N–65° E, E–W, and Aqaba.

Moreover, two seismic lines, WQ85-31B and 127, were interpreted, and their location was matched with the deduced tectonic map. The results show great matching between the location of the faults deduced from both the geomagnetic and seismic data. They agree completely with the well logging data.

Furthermore, these structures are correlated with the earthquake activities recorded by the Egyptian National Seismological Network (ENSN). The correlation implies that the studied area is more stable than other adjacent areas in the northern parts of Egypt close to the Mediterranean Sea and the Nile River Delta.
The ‘zoo’ of secondary instabilities precursory to stratified shear flow transition. Part 1 Shear aligned convection, pairing, and braid instabilities
Authors: Mashayek A. , Peltier W. R.
Published: September 2012

We study the competition between various secondary instabilities that co-exist in a preturbulent stratified parallel flow subject to Kelvin–Helmholtz instability. In particular, we investigate whether a secondary braid instability might emerge prior to the overturning of the statically unstable regions that develop in the cores of the primary Kelvin–Helmholtz billows. We identify two groups of instabilities on the braid. One group is a shear instability which extracts its energy from the background shear and is suppressed by the straining contribution of the background flow. The other group, which seems to have no precedent in the literature, includes phase-locked modes which grow at the stagnation point on the braid and are almost entirely driven by the straining contributions of the background flow. For the latter group, the braid shear has a negative influence on the growth rate. Our analysis demonstrates that the probability of finite-amplitude growth of both braid instabilities is enhanced with increasing Reynolds number and Richardson number. We also show that the possibility of emergence of braid instabilities decreases with the Prandtl number for the shear modes and increases for the stagnation point instabilities. Through detailed non-separable linear stability analysis, we show that both braid instabilities are fundamentally three dimensional with the shear modes being of small wavenumbers and the stagnation point modes dominating at large wavenumber.
From travelling waves to mild chaos: a supercritical bifurcation cascade in pipe flow
Authors: Mellibovsky F. , Eckhardt B.
Published: September 2012

We study numerically a succession of transitions in pipe Poiseuille flow that lead from simple travelling waves to waves with chaotic time-dependence. The waves at the origin of the bifurcation cascade are twofold azimuthally periodic, shift–reflect symmetric, and have a non-dimensional axial wavelength of $1. 927$ diameters. As the Reynolds number is increased, successive transitions result in a wide range of time-dependent solutions that include spiralling, modulated travelling, modulated spiralling, doubly modulated spiralling and mildly chaotic waves. Numerical evidence suggests that the latter spring from heteroclinic tangles of the stable and unstable invariant manifolds of two shift–reflect symmetric, modulated travelling waves. The chaotic set thus produced is confined to a limited range of Reynolds numbers, bounded by the occurrence of manifold tangencies. The subspace of discrete symmetry to which the states studied here belong makes many of the bifurcation and path-following investigations presented readily accessible. However, we expect that most of the phenomenology carries over to the full state space, thus suggesting a mechanism for the formation and break-up of invariant states that can give rise to chaotic dynamics.
II: Typology of Metal Shield Fittings
Authors: Dickinson Tania , Härke Heinrich
Published: September 2012

The classification presented here is based on a multivariate analysis of the shield bosses from the Upper Thames region, carried out in 1975 (Dickinson 1976, 274–90, figs. 25–9). Intuitive methods had failed to work, just as they had probably failed for previous scholars, because shield bosses seem to lack strikingly obvious diagnostic features. By contrast, the adoption of an explicit and more broadly-based approach not only took advantage of the substantial sample, but also was well suited to the circumstances of the enquiry. Residual doubts, however, meant that the results were not published at the time, though others have found the system both useful and valid (e.g. Welch 1983, 136–40, where the essentials are summarized; Hirst 1985, 91) and Heinrich Härke (HH) also adopted it as a base for the dating of shield burials in the course of his research. There is little excuse, therefore, for withholding publication further, and it is presented here substantially as it was written then, save for some modifications and additions.

The classification was devised as an aid to dating male graves in the context of a cultural-historical study of the Upper Thames cemeteries. Its aim was chronological order, and its principal assumption was that similarity of form reflected a similarity in time and space of production, use and final deposition. It was largely innocent of developments in the theoretical ramifications of artefact classification (e.g. Hill and Evans 1972; but see now especially Miller 1985), and no doubt both contains and obscures categories which have little or nothing to do with time and space: some of these are explored by HH later in this volume.
III. Shield Technology
Authors: Härke Heinrich
Published: September 2012

The following discussion takes account of recent work, published and unpublished, but is largely based on personal inspection of the remains of some 150 shields from Early Saxon burials (Appendix 5). Comparative evidence includes the well studied Sutton Hoo shield, essentially a Scandinavian shield in an Anglo-Saxon context (Bruce-Mitford 1978, 91), the Swedish parallels from Vendel Period burials at Valsgärde (seventh/eighth century AD), and the well preserved shield remains from Roman Iron Age bog deposits in the Continental homelands of the Anglo-Saxons (mostly third/fourth century AD).
V. The Shield in the Burial Rite
Authors: Härke Heinrich
Published: September 2012

Shields are among the more common grave goods in Early Anglo-Saxon burials. In the investigated sample of forty-seven cemeteries with a total of 3,814 inhumations, 317 burials (8·3 per cent) in forty-three cemeteries contained a shield (Appendix 3). The frequency of shields becomes even more apparent if it is translated into percentages of weapon burials: in England, just under half (45 per cent) of all inhumations with weapons had a shield. This proportion is significantly higher than in the contemporaneous weapon burials of Continental Saxons (18 per cent), Franks (16 per cent) and Alamanni (24 per cent; Härke 1989, table 4.2). Excavations of cremation cemeteries in England do not seem to have produced unambiguous remains of shields: the Anglo-Saxons, in contrast to the Continental Saxons, appear to have put shields only into inhumation burials.
Egalitarianism and the Separateness of Persons
Authors: VOORHOEVE ALEX , FLEURBAEY MARC
Published: September 2012

The difference between the unity of the individual and the separateness of persons requires that there be a shift in the moral weight that we accord to changes in utility when we move from makingintrapersonal trade-offs to makinginterpersonal trade-offs. We examine which forms of egalitarianism can, and which cannot, account for this shift. We argue that a form of egalitarianism which is concerned only with the extent of outcome inequality cannot account for this shift. We also argue that a view which is concerned with both outcome inequality and with the unfairness of inequality in individuals’ expected utilitiescanaccount for this shift. Finally, we limn an alternative view, on which such inequalities are not intrinsically bad, but nonetheless determine the strength of individuals’ competing claims. We argue that this ‘Competing Claims View’ can also account for the shift.
Prioritarianism and the Separateness of Persons
Authors: OTSUKA MICHAEL
Published: September 2012

For a prioritarian by contrast to a utilitarian, whether a certain quantity of utility falls within the boundary of one person's life or another's makes the following moral difference: the worse the life of a person who could receive a given benefit, the stronger moral reason we have to confer this benefit on this person. It would seem, therefore, that prioritarianism succeeds, where utilitarianism fails, to ‘take seriously the distinction between persons’. Yet I show that, contrary to these appearances, prioritarianism fails, in ways strikingly parallel to those in which utilitarianism fails, to take this distinction seriously. In so doing, I draw on and develop an earlier critique of prioritarianism by disentangling and pressing two distinct separateness-of-persons objections offered there. One objection is that prioritarianism is insensitive to ‘prudential justifications’. The other is that it is insensitive to the competing claims of different individuals.
Sulforaphane and erucin, natural isothiocyanates from broccoli, inhibit bacterial quorum sensing
Authors: Ganin Hadas , Rayo Josep , Amara Neri , Levy Niva , Krief Pnina , Meijler Michael M.
Published: September 2012

Sulforaphane and erucin, two natural isothiocyanates that are highly abundant in broccoli and other cruciferous vegetables, were found to strongly inhibit quorum sensing and virulence in Pseudomonas aeruginosa.
High-resolution Thomson scattering system on the COMPASS tokamak: Evaluation of plasma parameters and error analysis
Authors: Aftanas M. , Bohm P. , Bilkova P. , Weinzettl V. , Zajac J. , Zacek F. , Stockel J. , Hron M. , Panek R. , Scannell R. , Walsh M. J.
Published: September 2012

The electron density and temperature profiles measured by the Thomson scattering diagnostic on the COMPASS tokamak are used for estimation of electron kinetic energy, energy confinement time, and effective charge number Zeff. Data are compared with the line-integrated electron density measured by a microwave interferometer in an ohmically heated plasma with a circular cross section. An error analysis of both electron temperature and density are performed by two methods–a constant chi-square boundaries method and a Monte Carlo simulation, determining asymmetrical error bars for the electron temperature.
The spectral shift function and Levinson's theorem for quantum star graphs
Authors: Demirel Semra
Published: September 2012

We consider the Schrödinger operator on a star shaped graph with n edges joined at a single vertex. We derive an expression for the trace of the difference of the perturbed and unperturbed resolvent in terms of a Wronskian. This leads to representations for the perturbation determinant and the spectral shift function, and to an analog of Levinson's formula.
Investigation of thermal properties of mid-infrared AlGaAs/GaAs quantum cascade lasers
Authors: Pierściński K. , Pierścińska D. , Iwińska M. , Kosiel K. , Szerling A. , Karbownik P. , Bugajski M.
Published: September 2012

We report on detailed experimental investigation of thermal properties of AlGaAs/GaAs quantum cascade lasers (QCLs) emitting at wavelength of 9.4 μm. Different mounting options and device geometries are compared in terms of their influence on the relative increase of the active region temperature. High resolution, spatially resolved thermoreflectance is used for mapping temperature distribution over the facet of pulse operated QCLs. The devices’ thermal resistances are derived from experimental data. We also develop a numerical thermal model of QC lasers, solving heat transport equation in 2D and 3D, which includes anisotropy of thermal conductivity. By combining experimental and numerical results, an insight into thermal management in QCLs is gained. Thermal optimization of the design focuses on improving heat dissipation in the device, which is essential to increase the maximal operation temperature of the devices.
Radiochromic film measurement of spatial uniformity for a laser generated x-ray environment
Authors: Fisher J. H. , Newlander C. D. , Horton R. , Fournier K. B. , Emig J. , Patterson R. , Davis J. F. , Seiler S. , Jenkins P. P.
Published: September 2012

An existing x-ray source application (XRSA) test cassette was modified to hold multiple x-ray filter materials followed by two radiochromic film types (FWT-60 and HD-810 Gafchromic® film) to qualitatively characterize the spectral-spatial uniformity over the XRSA sample field of view. Multiple sets of film were examined and nominal set was determined. These initial, qualitative measurements suggest a low-energy regime (E < 3 keV) spatial anisotropy and spatial isotropy at higher energies (E > 3 keV).
Robustness of atomistic Gō models in predicting native-like folding intermediates
Authors: Estácio S. G. , Fernandes C. S. , Krobath H. , Faísca P. F. N. , Shakhnovich E. I.
Published: September 2012

Gō models are exceedingly popular tools in computer simulations of protein folding. These models are native-centric, i.e., they are directly constructed from the protein's native structure. Therefore, it is important to understand up to which extent the atomistic details of the native structure dictate the folding behavior exhibited by Gō models. Here we address this challenge by performing exhaustive discrete molecular dynamics simulations of a Gō potential combined with a full atomistic protein representation. In particular, we investigate the robustness of this particular type of Gō models in predicting the existence of intermediate states in protein folding. We focus on the N47G mutational form of the Spc-SH3 folding domain (x-ray structure) and compare its folding pathway with that of alternative native structures produced in silico. Our methodological strategy comprises equilibrium folding simulations, structural clustering, and principal component analysis.
Non-adiabatic effects within a single thermally averaged potential energy surface: Thermal expansion and reaction rates of small molecules
Authors: Alonso J. L. , Castro A. , Clemente-Gallardo J. , Echenique P. , Mazo J. J. , Polo V. , Rubio A. , Zueco D.
Published: September 2012

At non-zero temperature and when a system has low-lying excited electronic states, the ground-state Born–Oppenheimer approximation breaks down and the low-lying electronic states are involved in any chemical process. In this work, we use a temperature-dependent effective potential for the nuclei which can accommodate the influence of an arbitrary number of electronic states in a simple way, while at the same time producing the correct Boltzmann equilibrium distribution for the electronic part. With the help of this effective potential, we show that thermally activated low-lying electronic states can have a significant effect in molecular properties for which electronic excitations are oftentimes ignored. We study the thermal expansion of the Manganese dimer, Mn2, where we find that the average bond length experiences a change larger than the present experimental accuracy upon the inclusion of the excited states into the picture. We also show that, when these states are taken into account, reaction-rate constants are modified. In particular, we study the opening of the ozone molecule, O3, and show that in this case the rate is modified as much as a 20% with respect to the ground-state Born–Oppenheimer prediction.