bluuebunny/crossref_metadata_2025 huggingface dataset:
Oxime–Palladacycle‐Catalyzed Suzuki–Miyaura Arylation and Alkenylation of Aryl Imidazolesulfonates under Aqueous and Phosphane‐Free Conditions
Authors: Cívicos José Francisco , Alonso Diego A. , Nájera Carmen
Published: May 2012

Aryl and hetaroaryl imidazole‐1‐sulfonates are efficiently arylated and alkenylated with aryl‐ and alkenylboronic acids and potassium trifluoroborates by using 0.5 mol‐% palladacycles 1 or Pd(OAc)2 at 110 °C under aqueous and phosphane‐free conditions. Reactions can be performed by using conventional or microwave heating, leading to biaryls, stilbenes, and alkenylarenes in good to high yields, and high regio‐ and diastereoselectivities. The optimized methodology allows in situ phenol sulfonylation and one‐pot Suzuki arylation or alkenylation as well as orthogonal functionalization of halogen‐containing aryl imidazolesulfonates.
Upstream and downstream controls of recent avulsions on the Taquari megafan, Pantanal, south‐western Brazil
Authors: Makaske Bart , Maathuis Ben H. P. , Padovani Carlos R. , Stolker Chris , Mosselman Erik , Jongman Rob H. G.
Published: May 2012

Avulsion, the natural relocation of a river, is a key process in the evolution of subaerial fans, river floodplains and deltas. The causes of avulsion are poorly understood, which is partly due to the scarcity of field studies of present avulsions. At present, two avulsions are occurring on the middle and lower Taquari megafan, Pantanal basin, south‐western Brazil. Here we present an analysis of the causes of these avulsions based on field and remote sensing data and show that avulsions on megafans can be controlled by both upstream and downstream processes.

The middle fan avulsion (started in 1997–1998) is a result of upstream control: overbank aggradation was caused by the (variable) input of sandy sediment into the system, which caused channel‐belt superelevation and also created an easily erodible subsurface favouring bank retreat, crevassing, and scour of deep floodplain channels. The sandy subsurface in this area is inferred to have been a major factor in the causation of this avulsion under conditions of little gradient advantage.

The lower fan avulsion (started c. 1990) results from interplay of upstream and downstream controls, the latter being related to the local base level (the Paraguay River floodplain) at the toe of the fan. Channel and overbank aggradation on the lower fan was influenced by fan sub‐lobe progradation and channel backfilling. Fan sub‐lobe progradation caused a significant gradient advantage of the avulsion channel over the parent channel.

Avulsions are commonly supposed to be preferentially triggered by high‐magnitude floods, when there is considerable channel‐belt superelevation. However, both avulsions studied by us were triggered by small to average floods, with modest channel‐belt superelevation. We conclude that flood magnitude and channel‐belt superelevation have been overrated as causes of avulsion, and demonstrate additional causes that influence the growth of crevasses into avulsions. Copyright © 2012 John Wiley & Sons, Ltd.
Early recurrence or submucosal residual of laryngeal squamous cell carcinoma: Diagnosis by CT‐guided endolaryngeal core biopsy on a transcutaneous approach
Authors: Rousset Jean , Abgral Ronan , Chinellato Sandra , Garetier Marc , Barberot Céline , Valette Gérald , Potard Gaël , Le Bivic Thierry , Salaun Pierre–Yves
Published: May 2012

Background

Ultrasound and CT‐guided biopsy is a common procedure for histologic diagnosis of recurrence of head and neck squamous cell carcinoma. The present study describes a novel CT‐guided endolaryngeal puncture site.

Methods and Results

A 59‐year‐old man was treated for a T2N0M0 supraglottic laryngeal tumor by laser resection and bilateral lymph node dissection; exeresis was judged complete. Six‐month follow‐up found persistent dysphonia. Endoscopic examination and iterative biopsy gave reassuring results, but 18fluorodeoxyglucose positron emission tomography‐CT (18FDG PET‐CT) found highly suspicious increased right hemilaryngeal metabolic activity. Diagnosis of residual tumor was confirmed on CT‐guided endolaryngeal biopsy.

Conclusions

Image‐guided biopsy is the technique of choice in head and neck lesions that are deep or difficult to palpate and inaccessible to endoscopy. It is especially useful when recurrence is suspected after radiation therapy or cancer surgery. Many puncture sites have been reported in the literature; the present novel laryngeal approach extends the range of image‐guided biopsy, although further studies will be needed to assess possible morbidity. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Quantification of the effect of treatment duration on local‐regional failure after definitive concurrent chemotherapy and intensity‐modulated radiation therapy for squamous cell carcinoma of the head and neck
Authors: Platek Mary E. , McCloskey Susan A. , Cruz Myra , Burke Mark S. , Reid Mary E. , Wilding Gregory E. , Rigual Nestor R. , Popat Saurin R. , Loree Thom R. , Gupta Vishal , Warren Graham W. , Sullivan Maureen , Hicks Wesley L. , Singh Anurag K.
Published: May 2012

Background

The purpose of this study was to quantify the effect of treatment duration on locoregional progression after definitive concurrent chemoradiation (CCRT) for squamous cell carcinoma of the head and neck (SCCHN).

Methods

We conducted a retrospective chart review of patients treated between 2004 and 2010. After a prior analysis, measures were taken to limit therapy beyond 7 weeks. Comparison of outcomes were made between cohorts 1 (2004–2007, n = 78) and 2 (2007–2010, n = 62).

Results

Median therapy duration was statistically significantly different between cohorts as follows: 51 days, cohort 1 and 46 days, cohort 2 (p < .01). Locoregional progression in cohorts 1 and 2 was 19% and 5% (p = .01), respectively. On multivariate analysis, patients with prolonged treatment (≥57 days) had an 8‐fold increase in risk of locoregional progression compared to patients who completed on time (p < .01).

Conclusion

Treatment duration was a significant predictor of locoregional progression in patients with SCCHN who received definitive CCRT. © 2012 Wiley Periodicals, Inc. Head Neck, 2013
Lower liver-related death in African-American women with human immunodeficiency virus/hepatitis C virus coinfection, compared to Caucasian and Hispanic women
Authors: Sarkar Monika , Bacchetti Peter , French Audrey L. , Tien Phyllis , Glesby Marshall J. , Nowicki Marek , Plankey Michael , Gange Stephen , Sharp Gerald , Minkoff Howard , Peters Marion G.
Published: May 2012

Among individuals with and without concurrent human immunodeficiency virus (HIV), racial/ethnic differences in the natural history of hepatitis C virus (HCV) have been described. African Americans have lower spontaneous HCV clearance than Caucasians, yet slower rates of liver fibrosis once chronically infected. It is not clear how these differences in the natural history of hepatitis C affect mortality, in either HIV-positive or -negative individuals. We conducted a cohort study of HIV/HCV coinfected women followed in the multicenter Women's Interagency HIV Study to determine the association of self-reported race/ethnicity with all-cause and liver-related mortality. Survival analyses were performed using Cox's proportional hazards models. The eligible cohort (n = 794) included 140 Caucasians, 159 Hispanics, and 495 African Americans. There were 438 deaths and 49 liver-related deaths during a median follow-up of 8.9 years and maximum follow-up of 16 years. African-American coinfected women had significantly lower liver-related mortality, compared to Caucasian (hazard ratio [HR], 0.41; 95% confidence interval [CI]: 0.19-0.88;

P

= 0.022) and Hispanic coinfected women (HR, 0.38; 95% CI: 0.19-0.76;

P

= 0.006). All-cause mortality was similar between racial/ethnic groups (HRs for all comparisons: 0.82-1.03; log-rank test:

P

= 0.8).

Conclusions :

African-American coinfected women were much less likely to die from liver disease, as compared to Caucasians and Hispanics, independent of other causes of death. Future studies are needed to investigate the reasons for this marked racial/ethnic discrepancy in liver-related mortality.
Assessing the prevalence of mental health disorders and mental health needs among preschool children in care in England
Authors: Hillen Thomas , Gafson Leonie , Drage Laura , Conlan Louise‐Margaret
Published: May 2012

Although school‐aged children living in foster care have been identified as a high‐risk group for mental health and developmental disorders, there is a paucity of data relating to preschool children in care (CIC). This study aimed to identify the prevalence of mental health and developmental disorders along with corresponding need for interventions in preschool CIC. All CIC aged 0 to 5 years in an inner city local authority underwent comprehensive, multifaceted assessments consisting of the Ages and Stages Questionnaire (J. Squires, D. Bricker, & E. Twombly, 2003), interviews with caregivers based on the Preschool Age Psychiatric Assessment (H.L. Egger & A. Angold, 2006), Mullen Scales of Early Learning (E.M. Mullen, 1995), and systematic clinical observation. Of 58 eligible preschoolers, 43 completed the assessment. At least one mental health disorder was found in 26 (60.5%) participants, and at least one developmental disorder was found in 11 (25.6%). When mental health and/or developmental disorders were considered together, 30 (69.8%) preschoolers fulfilled criteria for at least one diagnosis, and 18 (41.9%) had two or more comorbid conditions. Whereas 36 (83.7%) of the preschoolers needed an intervention, only 3 of these had received adequate input. In conclusion, preschool CIC constitute a high‐risk group for mental health and developmental disorders. Without age‐appropriate assessments, their needs go undetected, and opportunities for early intervention are being missed.
Emotionally avoidant language in the parenting interviews of substance‐dependent mothers: Associations with reflective functioning, recent substance use, and parenting behavior
Authors: Borelli Jessica L. , West Jessica L. , Decoste Cindy , Suchman Nancy E.
Published: May 2012

Parenting and emotion regulation are two known, and potentially interrelated, areas of impairment among substance‐abusing mothers. In this study, we examine substance ‐abusing mothers' (positive and negative) emotion language word use during their discussion of negative parenting experiences on the Parent Development Interview for its association with reflective functioning (RF), recent substance‐use history, and sensitivity to child cues. Within a sample of 47 methadone‐maintained mothers, we evaluate the hypothesis that linguistic evidence of emotional avoidance (more frequent positive feeling words and less frequent negative emotion words) will be associated with lower RF, more recent substance use, and more insensitive parenting. Further, we evaluate whether language use mediates the association between self‐focused RF and insensitive parenting. Results of hierarchical regressions suggest that more frequent positive feeling word use, but not negative emotion word use, is associated with lower RF, more recent substance use, and lower sensitivity to child cues. Positive feeling word use partially mediates the association between self‐focused RF and insensitive parenting. Results are discussed in the context of their contribution to the literature on emotion and parenting in substance‐abusing populations.
Changes in nutrient allocation between roots and shoots of young maize plants during sulfate deprivation
Authors: Bouranis Dimitris L. , Chorianopoulou Styliani N. , Siyiannis Vassilis F. , Protonotarios Vassilis E. , Koufos Christos , Maniou Philippa
Published: May 2012

Hydroponically grown maize (Zea mays L.) plants were deprived of the external source of sulfate following an initial period of 13 d during which the sulfur (S) supply was sufficient. The amounts of dry mass (DM), water, sulfate, sulfur, nitrate, ammonium, nitrogen, phosphorus, potassium, magnesium, calcium, boron, iron, copper, zinc, and manganese were monitored in the shoots and the roots for 10 d. The deprivation altered the nutritional balance between them, causing a 70% decrease of sulfate in shoots and roots after 2 d. At 10 d, 95% of sulfate had vanished in both shoots and roots. Total S remained rather constant in shoots or was slightly decreased in roots after 4 d. This coincided with a decrease of Fe in shoots after 4 d. The calculated decreases of S and Fe in –S shoots, up to 6 d were linearly correlated. Kinetic analysis of the changes revealed a sequence in their onset, and we distinguished early and late changes. Among the early changes, we highlight the following ones: (1) an increased amount of Cu in both shoots and roots at 2 d; Fe was 40% decreased in both shoots and roots at 2 d; (2) a decrease in transpiration rate by 35% after 2 d; (3) alterations in boron allocation; in –S shoots the % changes in S were linearly correlated with the corresponding % changes in B; (4) calcium content was not affected by the S deprivation in –S shoots, whilst it increased in –S root after d 2; (5) Mn and Mg decreased from the beginning and in a uniform fashion in both –S shoots and roots. Day 6 may be considered as the boundary between the early and late changes. The root fraction of DM increased progressively after 4 d. Changes in DM seemed to be similar to those of P. Changes of Zn also took place rather late. In –S shoots and for the time interval between 6 d and 10 d, linear correlations were found between the corresponding % changes of the pairs DM–S, DM–P, DM–N, DM–water, S–N, S–P, and N–P.
Ferroelectric Q and antiferroelectric P phases' coexistence and local phase transitions in oxygen‐deficient NaNbO3 single crystal: micro‐Raman, dielectric and dilatometric studies
Authors: Shakhovoy R. A. , Raevskaya S. I. , Shakhovaya L. A. , Suzdalev D. V. , Raevski I. P. , Yuzyuk Yu. I. , Semenchev A. F. , El Marssi M.
Published: May 2012

Micro‐Raman studies of oxygen‐deficient gray‐colored NaNbO3 single crystals have shown that at room temperature both antiferroelectric P and ferroelectric Q phases are present simultaneously as separate regions tens of micrometers in size. Phase transitions in P and Q regions have been elucidated by dielectric, dilatometric and micro‐Raman studies. For the first time, the sequence of phase transitions between antiferroelectric phase P and ferroelectric Q and N phases has been revealed. Copyright © 2012 John Wiley & Sons, Ltd.
Surface‐enhanced Raman scattering investigations on silver nanoparticles deposited on alumina and titania nanotubes: influence of the substrate material on surface‐enhanced Raman scattering activity of Ag nanoparticles
Authors: Kudelski Andrzej , Pisarek Marcin , Roguska Agata , Hołdyński Marcin , Janik‐Czachor Maria
Published: May 2012

Silver nanoparticles deposited on various ‘inert’ porous materials (mainly Al2O3 and TiO2) are often used as substrates for surface‐enhanced Raman scattering (SERS) measurements. In this study, we used the sputter deposition technique to cover tubular arrays of Al2O3 and TiO2 with Ag nanoparticles. Raman spectra of pyridine (as a probe molecule) and of two selected dyes (5‐(4‐dimethylaminobenzylidene)rhodanine and 5‐(4‐(dimethylamino)benzylidene)‐3‐(3‐methoxypropyl)rhodanine) adsorbed on fabricated Ag/TiO2‐n/Ti and Ag/Al2O3‐n/Al substrates were measured. We found that the SERS spectra of pyridine adsorbed on Ag nanoparticles deposited on an Al2O3‐n/Al substrate are distinctly different from those measured for an Ag/TiO2‐n/Ti composite. Similar effects were observed for dyes adsorbed on the surface of both composites. The spectral differences between two kinds of composites (Ag/TiO2‐n/Ti and Ag/Al2O3‐n/Al) are discussed in terms of (1) the modified electronic structure of the Ag nanoparticles due to their interaction with different substrate materials and (2) the different atomic topology of the metal particles thus deposited on the surfaces of the substrates. Composite samples were also studied with the aid of scanning electron microscopy (SEM) and Auger electron spectroscopy (AES) to reveal their characteristic morphological and chemical features. Copyright © 2012 John Wiley & Sons, Ltd.
Expression and phylogeny of candidate genes for sex differentiation in a primitive fish species, the Siberian sturgeon, Acipenser baerii
Authors: Berbejillo Julio , Martinez‐Bengochea Anabel , Bedo Gabriela , Brunet Frédéric , Volff Jean‐Nicolas , Vizziano‐Cantonnet Denise
Published: May 2012

The molecular mechanisms underlying testis differentiation in basal actinopterygian fish remains poorly understood. The sex differentiation period was investigated in the Siberian sturgeon, Acipenser baerii, by expression profiling of Sertoli cell transcription factors (dmrt1, sox9) that control testis differentiation in vertebrates; Leydig cell factors (cyp17a1, star) affecting androgen production; the androgen receptor (ar); a growth factor controlling testis development (igf1); and a gene coding for a gonadotropin hormone (lh). Two genes were characterised for the first time in the Siberian sturgeon (dmrt1, cyp17a1), while the others came from public databases. Sturgeon gonad development is very slow, with a late sexual differentiation time during their juvenile stage, and are still immature at 3 years of age. Immature fish showed a sex‐dimorphic pattern; all the genes studied displayed a higher expression level in male gonads. We took advantage of the presence of juvenile fish with pre‐ and post‐differentiated gonads (16 and 18 months old) to characterise them at the molecular level. The post‐differentiated fish displayed a sex dimorphism of gene expression in their gonads for all genes studied, with the exception of sox9. The trends in undifferentiated fish lead us to propose that sturgeons undergoing male differentiation express high levels of Sertoli cell factors (dmrt1, sox9) and of genes involved in the production and receptivity of androgens (cyp17a1, star and ar) together with lh. Expression profiles and phylogenetic studies suggest that these genes are potential regulators of testis development in the Siberian sturgeon.Mol. Reprod. Dev. 79: 504‐504, 2012. © 2012 Wiley Periodicals, Inc.
Volumetric measurement of perfusion and arterial transit delay using hadamard encoded continuous arterial spin labeling
Authors: Dai Weiying , Shankaranarayanan Ajit , Alsop David C.
Published: May 2012

Creating images of the transit delay from the labeling location to image tissue can aid the optimization and quantification of arterial spin labeling perfusion measurements and may provide diagnostic information independent of perfusion. Unfortunately, measuring transit delay requires acquiring a series of images with different labeling timing that adds to the time cost and increases the noise of the arterial spin labeling study. Here, we implement and evaluate a proposed Hadamard encoding of labeling that speeds the imaging and improves the signal‐to‐noise ratio efficiency. Volumetric images in human volunteers confirmed the theoretical advantages of Hadamard encoding over sequential acquisition of images with multiple labeling timing. Perfusion images calculated from Hadamard encoded acquisition had reduced signal‐to‐noise ratio relative to a dedicated perfusion acquisition with either assumed or separately measured transit delays, however. Magn Reson Med 69:1014–1022, 2013. © 2012 Wiley Periodicals, Inc.
Muscle function in A canine model of X‐linked myotubular myopathy
Authors: Grange Robert W. , Doering Jon , Mitchell Erin , Holder Melanie N. , Guan Xuan , Goddard Melissa , Tegeler Christopher , Beggs Alan H. , Childers Martin K.
Published: May 2012

Introduction: We established a colony of dogs that harbor an X‐linked MTM1 missense mutation.Muscle from affected male dogs exhibits reduction and altered localization of the MTM1 gene product, myotubularin, and provides a model analogous to X‐linked myotubular myopathy (XLMTM). Methods: We studied hindlimb muscle function in age‐matched canine XLMTM genotypes between ages 9 and 18 weeks. Results: By the end of the study, affected dogs produce only ∼15% of the torque generated by normals or carriers (0.023 ± 0.005 vs. 0.152 ± 0.007 and 0.154 ± 0.003 N‐m/kg body mass, respectively, P < 0.05) and are too weak to stand unassisted. At this age, XLMTM dogs also demonstrate an abnormally low twitch:tetanus ratio, a right‐shifted torque‐frequency relationship and an increase in torque during repetitive stimulation (P < 0.05). Conclusions: We hypothesize that muscle weakness results from impaired excitation‐contraction (E‐C) coupling. Interventions that improve E‐C coupling might be translated from the XLMTM dog model to patients. Muscle Nerve 46: 588–591, 2012
Incidence and trends in Burkitt lymphoma in northern Tanzania from 2000 to 2009
Authors: Aka Peter , Kawira Esther , Masalu Nestory , Emmanuel Benjamin , Brubaker Glen , Magatti Josiah , Mbulaiteye Sam M.
Published: May 2012

Introduction

Burkitt lymphoma (BL) is endemic in parts of Tanzania, but there is scant country or region level data about burden and trends of BL in Tanzania over the past three decades. Here, we update baseline epidemiology of BL in northern Tanzania using recent data.

Procedure

Data for childhood BL diagnosed at six hospitals in Mara and Mwanza regions in northern Tanzania during 2000–2009 were compiled. Age, sex, and regional patterns were analyzed. Crude incidence rates of BL were calculated by sex, anatomic site, geographical region, and calendar year.

Results

Among 944 cases, 549 (58%) were male (male/female case ratio 1.4:1). Among those with known anatomic site (92%), facial only tumors represented a large proportion of tumors in boys than girls (50% vs. 36%, P < 0.002). Tumors occurred at a younger mean age in boys than girls (6.8 years vs. 7.6 years, P < 0.01). Crude BL incidence was 4.2 per 100,000, but varied by region (3.0 in Mwanza vs. 6.8 in Mara, P = 0.01), by district (1.4–22), by gender (5.0 in boys vs. 4.0 in girls), and by age group (2.0 in 0–4, 7.8 in 5–9, and 3.1 in 10–15 years). BL incidence peaked in 2001 and decreased gradually thereafter.

Conclusions

Our results indicate that male sex, young age, and geographical characteristics are risk factors for BL in Tanzania. BL incidence declined with calendar year, but the significance of this finding is uncertain. Well‐designed epidemiological studies of BL in Tanzania may shed light on environmental characteristics underlying these patterns. Pediatr Blood Cancer 2012; 59: 1234–1238. © 2012 Wiley Periodicals, Inc.
Effect of thermal stability on protein adsorption to silica using homologous aldo‐keto reductases
Authors: Felsovalyi Flora , Patel Tushar , Mangiagalli Paolo , Kumar Sanat K. , Banta Scott
Published: May 2012

Gaining more insight into the mechanisms governing the behavior of proteins at solid/liquid interfaces is particularly relevant in the interaction of high‐value biologics with storage and delivery device surfaces, where adsorption‐induced conformational changes may dramatically affect biocompatibility. The impact of structural stability on interfacial behavior has been previously investigated by engineering nonwild‐type stability mutants. Potential shortcomings of such approaches include only modest changes in thermostability, and the introduction of changes in the topology of the proteins when disulfide bonds are incorporated. Here we employ two members of the aldo‐keto reductase superfamily (alcohol dehydrogenase, AdhD and human aldose reductase, hAR) to gain a new perspective on the role of naturally occurring thermostability on adsorbed protein arrangement and its subsequent impact on desorption. Unexpectedly, we find that during initial adsorption events, both proteins have similar affinity to the substrate and undergo nearly identical levels of structural perturbation. Interesting differences between AdhD and hAR occur during desorption and both proteins exhibit some level of activity loss and irreversible conformational change upon desorption. Although such surface‐induced denaturation is expected for the less stable hAR, it is remarkable that the extremely thermostable AdhD is similarly affected by adsorption‐induced events. These results question the role of thermal stability as a predictor of protein adsorption/desorption behavior.
Holographic cosmological backgrounds, Wilson loop (de)confinement and dilaton singularities
Authors: Erdmenger J. , Ghoroku K. , Meyer R. , Papadimitriou I.
Published: May 2012

We review a construction of holographic geometries dual to ℳ︁ = 4 SYM theory on a Friedmann‐Robertson‐Walker background and in the presence or absence of a gluon condensate and instanton density. We find the most general solution with arbitrary scale factor and show that it is diffeomorphic to topological black holes. We introduce a time‐dependent boundary cosmological constant λ(t) and show energy‐momentum conservation in this background. For constant λ, the deconfinement properties of the temporal Wilson loop are analysed. In most cases the Wilson loop confines throughout cosmological evolution. However, there is an exceptional case which shows a transition from deconfinement at early times to confinement at late times. We classify the presence or absence of horizons, with important implications for the Wilson loop.
Toric bases for 6D F‐theory models
Authors: Morrison D.R. , Taylor W.
Published: May 2012

We find all smooth toric bases that support elliptically fibered Calabi‐Yau threefolds, using the intersection structure of the irreducible effective divisors on the base. These bases can be used for F‐theory constructions of six‐dimensional quantum supergravity theories. There are 61,539 distinct possible toric bases. The associated 6D supergravity theories have a number of tensor multiplets ranging from 0 to 193. For each base an explicit Weierstrass parameterization can be determined in terms of the toric data. The toric counting of parameters matches with the gravitational anomaly constraint on massless fields. For bases associated with theories having a large number of tensor multiplets, there is a large non‐Higgsable gauge group containing multiple irreducible gauge group factors, particularly those having algebras 𝔢8, 𝔣4, and 𝔤g2 ⊕ 𝔰𝔲(2) with minimal (non‐Higgsable) matter.
Structural insights into the transmembrane domains of human copper transporter 1
Authors: Yang Lei , Huang Zhaowei , Li Fei
Published: May 2012

The human copper transporter 1 (hCtr1) mediates cellular uptake of copper and Pt‐based chemotherapeutic anticancer drugs. In this paper, we determined the three‐dimensional structure and oligomerization of the transmembrane domains (TMDs) of hCtr1 in 40% HFIP aqueous solution by using solution‐state NMR spectroscopy. We firstly revealed that TMD1 forms an α‐helical structure from Gly67 to Glu84 and is dimerized by close packing of its C‐terminal helix; TMD2 forms an α‐helical structure from Leu134 to Thr155 and is self‐associated as a trimer by the hydrophobic contact of TMD2 monomers; TMD3 adopts a discontinuous helix structure, known as ‘α‐helix‐coiled segment‐α‐helix’, and is dimerized by the interaction between the N‐terminal helices. The motif GxxxG in TMD3 is not fully involved in the helix, but partially unstructured as a linker between helices. The flexible linker of TMD3 may serve as a gating adapter to mediate pore on and off switch. The differences in the structure and aggregation of the TMD peptides may be related to their different roles in the channel formation and transport function. Copyright © 2012 European Peptide Society and John Wiley & Sons, Ltd.
Protein backbone structure determination using RDC: An inverse kinematics approach with fast and exact solutions
Authors: Pantos Sotirios I. , Tiligada Ekaterini
Published: May 2012

Residual dipolar couplings (RDC) of proteins dissolved in anisotropic media promise to speed up the determination of protein structures. We consider the backbone as a robotic mechanism and formulate inverse kinematics problems using RDC restraints from two media. The φ, ψ of each secondary structure element (SSE) are computed from oriented vectors in consecutive peptide planes. We search for the optimum conformation joining the solutions of two independent backbone halves. The matrix transforming the vector Z of a global frame from one SSE into the other determines their orientation. Three distance constraints between two oriented SSE determine their relative position by solving nine polynomial equations. The benefit of this method is that complete and accurate solutions are obtained overcoming the local minima problems of heuristic procedures. The algorithm is implemented on MAPLE using the least number of experimental data; the runtimes take an order of seconds on a common PC. © 2013 Wiley Periodicals, Inc.
Strategies for MCR image analysis of large hyperspectral data‐sets
Authors: Scurr David J. , Hook Andrew L. , Burley Jonathan , Williams Philip M. , Anderson Daniel G. , Langer Robert , Davies Martyn C. , Alexander Morgan R.
Published: May 2012

Polymer microarrays are a key enabling technology for high throughput materials discovery. In this study, multivariate image analysis, specifically multivariate curve resolution (MCR), is applied to the hyperspectral time of flight secondary ion mass spectroscopy (ToF‐SIMS) data from eight individual microarray spots. Rather than analysing the data individually, the data‐sets are collated and analysed as a single large data‐set. Desktop computing is not a practical method for undertaking MCR analysis of such large data‐sets due to the constraints of memory and computational overhead. Here, a distributed memory High‐Performance Computing facility (HPC) is used. Similar to what is achieved using MCR analysis of individual samples, the results from this consolidated data‐set allow clear identification of the substrate material; furthermore, specific chemistries common to different spots are also identified. The application of the HPC facility to the MCR analysis of ToF‐SIMS hyperspectral data‐sets demonstrates a potential methodology for the analysis of macro‐scale data without compromising spatial resolution (data ‘binning’). Copyright © 2012 John Wiley & Sons, Ltd.
What We Talk About When We Talk About Taxes
Authors: Kidder Jeffrey L. , William Martin Isaac
Published: May 2012

Taxes are a preeminent issue in domestic politics, but the prevalence, content, and shape of public discussion on taxation is often perplexing to social researchers. We argue that part of the confusion arises from the lack of qualitative data on the meanings Americans associate with taxation. In order to remedy this lack we conducted semi‐structured interviews with white, Southern, small business owners. In answering our questions, our respondents constructed narratives that connected taxation with exploitation and a loss of personal freedom. We propose that everyday fiscal discourse is morally charged and interconnected with boundary work and a sense of group position. Further, qualitative research into tax talk can help make sense of the current political and social landscape (e.g., the continued cultural saliency of the Tea Party).
Teacher Careers and Inhabited Institutions: Sense‐Making and Arsenals of Teaching Practice in Educational Institutions
Authors: Everitt Judson G.
Published: May 2012

This article advances emerging scholarship that emphasizes the benefits to new institutional theories of organizational functioning offered by empirical research rooted in the tradition of symbolic interactionism. I present evidence from in‐depth interviews with teachers from three high schools to show how individuals' perspectives about pursuing institutional goals are filtered through their accumulated experience working within those institutions. Findings show teachers develop what I call “arsenals of teaching practice” as they accumulate work experience, and this process creates a key source of difference by career stage among teachers that shapes their instructional decisions. I discuss implications for understanding the relationship between policy and practice, and extend existing theory of inhabited institutions by identifying a key way that people's sense‐making through experience drives institutional functioning.
The flexural vibration of V shaped atomic force microscope cantilevers by using the Timoshenko beam theory
Authors: Sadeghi A.
Published: May 2012

The resonant frequency of flexural vibration for a V shaped atomic force microscope (AFM) cantilever has been investigated using the Timoshenko beam theory. Generally, three different regions are considered for V shaped cantilevers, one region with constant cross section and height and two double tapered regions. In this paper, the effects of the different parameters on the non‐dimensional frequency and sensitivity to the contact stiffness have been studied. The differential quadrature method (DQM) is applied to solve the nonlinear differential equations of motion. The results show that the resonant frequency decreases when Timoshenko beam parameter or cantilever thickness increases and high order modes are more sensitive to it. The first frequency is sensitive only in the lower range of contact stiffness, but the high order frequencies are sensitive to the contact stiffness in a larger range. It is possible to increase the range of sensitivity to the contact stiffness by increasing the width ratio for the first mode. By increasing both height and breadth taper ratios the resonant frequency increases. The resonant frequency is sensitive to the width ratio and by increasing this ratio, the resonant frequency decreases, but critical contact stiffness increases and finally the variations of the height and breadth taper ratios and width ratio are affected on the sensitivity to the contact stiffness. We show that the sensitivity to the contact stiffness can be increased by the variations of height taper ratio and this matter has never been investigated formerly.
Microstructure‐based modelling and FE implementation of filler‐induced stress softening and hysteresis of reinforced rubbers
Authors: Lorenz H. , Klüppel M. , Heinrich G.
Published: May 2012

Reinforcement of rubber by nanoscopic fillers induces strong nonlinear mechanical effects such as stress softening and hysteresis. The proposed model aims to describe these effects on a micromechanical level in order to predict the stress‐strain behaviour of a rubber compound. The material parameters can be obtained by fitting stress‐strain tests. These quantities have a clear defined physical meaning. The previously introduced “dynamic flocculation model” was extended for general deformation histories. Stress softening is modelled by hydrodynamic reinforcement of rubber elasticity due to strain amplification by stiff filler clusters. Under stress these clusters can break and become softer, leading to a decreasing strain amplification factor. Hysteresis is attributed to cyclic breakdown and re‐aggregation of damaged clusters. When stress‐strain cycles are not closed, not all of these clusters are broken at the turning points. For the resulting “inner cycles” additional elastic stress contributions of clusters are taken into account. The uniaxial model has been generalized for three‐dimensional stress states using the concept of representative directions. The resulting 3D‐model was implemented into a Finite Element code, and an example simulation is shown. Good agreement between measurement and simulation is obtained for uniaxial inner cycles, while the 3D‐generalization simulates the behaviour closer to the experiment than the original model.
Characteristic directions of closed planar motions
Authors: Dathe H. , Gezzi R.
Published: May 2012

We investigate some properties of closed planar motions. These motions appear between two coordinate systems, fixed and moving. We focus on three aspects: The area enclosed by the paths of points belonging to each of these reference systems, the polar moment of inertia, and the natural average of a path. First, we consider a formula proposed by Jakob Steiner. It states that, for a motion with a complete turn, the points enclosing the same area lie on a circle. Moreover, all circles for different areas have a common center. We start by deriving the Steiner formula relative to both frames. We emphasize that, for practical applications such as in biomechanics, the Steiner circle reduces to a straight line. Then, the centrodes are considered in relation to the Steiner point or normal. We next consider the polar moment of inertia. Its coefficients are shown to be related to those of the Steiner point or normal. Thirdly, the natural average of a path is introduced. Its coefficients are shown to be related to those previously discussed. Finally, we show how the results can be applied to experimentally measured motions. As an example, we consider human gait in the sagittal direction. The most important part of this motion is described as a double hinge driven by the hip and knee angle, which is a simple model for a planar motion. We conclude that, for practical purposes, the Steiner line allows us to visualize a selected direction of motion under consideration.
Fake supersymmetry versus Hamilton-Jacobi
Authors: Trigiante Mario , Van Riet Thomas , Vercnocke Bert
Published: May 2012

Abstract

We explain when the first-order Hamilton-Jacobi equations for black holes (and domain walls) in (gauged) supergravity, reduce to the usual first-order equations derived from a fake superpotential. This turns out to be equivalent to the vanishing of a newly found constant of motion and we illustrate this with various examples. We show that fake supersymmetry is a necessary condition for having physically sensible extremal black hole solutions. We furthermore observe that small black holes become scaling solutions near the horizon. When combined with fake supersymmetry, this leads to a precise extension of the attractor mechanism to small black holes: the attractor solution is such that the scalars move on specific curves, determined by the black hole charges, that are purely geodesic, although there is a non-zero potential.
Holographic no-boundary measure
Authors: Hertog Thomas , Hartle James
Published: May 2012

Abstract

We show that the complex saddle points of the no-boundary wave function with a positive cosmological constant and a positive scalar potential have a representation in which the geometry consists of a regular Euclidean AdS domain wall that makes a smooth transition to a Lorentzian, inflationary universe that is asymptotically de Sitter. The transition region between AdS and dS regulates the volume divergences of the AdS action and accounts for the phases that explain the classical behavior of the final configuration. This leads to a dual formulation in which the semiclassical no-boundary measure is given in terms of the partition function of field theories on the final boundary that are certain relevant deformations of the CFTs that occur in AdS/CFT. We conjecture that the resulting dS/CFT duality holds also beyond the leading order approximation.
Effect of Triclosan‐Coated Sutures on the Incidence of Surgical Wound Infection After Lower Limb Revascularization Surgery: A Randomized Controlled Trial
Authors: Turtiainen Johanna , Saimanen Eija I. T. , Mäkinen Kimmo T. , Nykänen Antti I. , Venermo Maarit A. , Uurto Ilkka T. , Hakala Tapio
Published: May 2012

Background

Surgical wound infection (SWI) is a common complication after peripheral vascular surgery. In a prospective study, triclosan‐coated sutures were reported to decrease the incidence of surgical site infection after various surgical procedures. The aim of our study was to test the hypothesis that use of triclosan‐coated sutures decreases the incidence of SWI after lower limb vascular surgery.

Methods

This prospective, randomized, multicenter, double‐blinded trial was conducted between July 2010 and January 2011 in five hospitals in Finland. We randomly allocated 276 patients undergoing lower limb revascularization surgery to a study (n = 139) or a control (n = 137) group. Surgical wounds in the study group were closed with triclosan‐coated suture material, and wounds in the control group were closed with noncoated sutures. The main outcome measure was SWI. A surgical wound complication was considered to be an infection if there were bacteria isolated from the wound or if there were areas of localized redness, heat, swelling, and pain around the wound appearing within 30 days after the operative procedure. Logistic regression analysis was used to assess the independent effect of triclosan‐coated sutures on the incidence of SWI.

Results

Altogether, 61 (22.1 %) patients developed SWI. SWI occurred in 31 (22.3 %) patients in the study group and in 30 (21.9 %) patients in the control group (odds ratio 1.10, 95% confidence interval 0.61–2.01, p = 0.75.)

Conclusions

The use of triclosan‐coated sutures does not reduce the incidence of SWI after lower limb vascular surgery.
Implications of seasonal variation in nitrate export from forested ecosystems: a review from the hydrological perspective of ecosystem dynamics
Authors: Ohte Nobuhito
Published: May 2012

In recent decades, the seasonal variation in NO3− discharge from forest ecosystems has been used increasingly by ecologists and hydrologists as a diagnostic indicator of the nutrient status of ecosystems. Major factors underlying the seasonal patterns of stream NO3− concentration include seasonal variations in (1) ecosystem nutrient demand, (2) solute transport capability of the hydrological condition, and (3) in‐stream nutrient usage and supply. In this article I show how case studies have helped elucidate the dominant controlling factors by comparing data from Japanese catchments with previously compiled data from studies in North America and Europe. Moreover, I explain the different influences that hydrological and biogeochemical controls exert in regions with rainy (Japan) and dry (northeastern United States and Europe) summers. The seasonal variation in hydrological conditions is the predominant controlling factor in Japanese forests, whereas nutrient demand may predominate in the northeastern United States and Europe. I emphasize the importance of comparing seasonal patterns among regions with differing climates to obtain more universal explanations of seasonal variations in NO3−‐related biogeochemical and hydrological dynamics in a forest ecosystem. In addition, multi‐scale investigations will be needed to provide insight into the relative contributions of hillslope biogeochemical effects and in‐stream biological activities.
On the response of large-amplitude internal waves to upstream disturbances
Authors: Camassa Roberto , Viotti Claudio
Published: May 2012

Large-amplitude internal solitary waves generate shear flows that intensify from the wings of the waves to their maxima. Upstream perturbations of the hydrostatic equilibrium in the form of wave packets along the path of wave propagation are expected to trigger shear instability and ultimately generate Kelvin–Helmholtz roll-ups. In contrast, as shown here with accurate simulations of incompressible stratified Euler equations, large internal waves can act as suppressors of perturbations. The precise understanding of the mechanisms leading to different outcomes, including whether instability is excited, is the focus of this work. Under the action of shear flows, small-amplitude wave packets undergo stretching and filamentation, which lead to significant absorption of perturbation energy into the background shear. It is found that this typical behaviour is present in the self-induced shear by internal waves, regardless of whether the shear is stable or unstable, and can leave a quieter state in the wave’s wake for a wide range of perturbation parameters. In the unstable case, even once perturbations are selected to excite the instability, our results show that this absorption can act to reduce growth in the strong-shear region, effectively making roll-up development observable only downstream of the wave crest. Our approach is both analytical and numerical; a model valid for relatively thin pycnoclines and suitable for local spectral analysis is devised and used. Energy diagnostics on the simulations are implemented to validate the numerics and illustrate the energy exchanges between background wave flow and its shear. A link between the absorption mechanism and the clustering of local eigenvalues along the wave is proposed. This promotes an energetic coupling among neutral modes stronger than what may be expected to occur in slowly varying flows, and gives rise to multi-modal transient dynamics of the kind often referred to as non-normality effects. For those cases in which the wave-induced shear meets the conditions for local instability, it is found that the growth of disturbances is selective with respect to the sign of the mode excited upstream. Elements of this phenomenon are interpreted by asymptotic analysis for spatial growth in time-independent slowly varying media.
APPROXIMATELY BIPROJECTIVE BANACH ALGEBRAS AND NILPOTENT IDEALS
Authors: POURMAHMOOD-AGHABABA HASAN
Published: May 2012

By introducing a new notion of approximate biprojectivity we show that nilpotent ideals in approximately amenable or pseudo-amenable Banach algebras, and nilpotent ideals with the nilpotency degree larger than two in biflat Banach algebras cannot have the special property which we call ‘property (𝔹)’ (Definition 5.2 below) and hence, as a consequence, they cannot be boundedly approximately complemented in those Banach algebras.
Total thyroidectomy for amiodarone-associated thyrotoxicosis: should surgery always be delayed for pre-operative medical preparation?
Authors: Pierret C , Tourtier J-P , Pons Y , Merat S , Duverger V , Perrier E
Published: May 2012

Objective:

Amiodarone can induce severe hyperthyroidism that justifies its withdrawal and the introduction of antithyroid drugs. Continuing amiodarone use, failure to control hyperthyroidism and poor clinical progress may require thyroidectomy. This study aimed to evaluate patients’ post-operative development and mid-term outcome after thyroidectomy for amiodarone-associated thyrotoxicosis.

Study design:

Prospective case series.

Setting:

Tertiary care centre.

Subjects and methods:

We prospectively collected cases of amiodarone-associated thyrotoxicosis requiring thyroidectomy due to failure of antithyroid treatment, despite amiodarone discontinuation. Post-thyroidectomy complications were compared immediately, 30 days and one year post-operatively, and also for scheduled versus emergency surgery cases.

Results:

Of 11 total cases, nine scheduled thyroidectomy cases had no morbidity after elective surgery. Two cases required emergency surgery for multiple organ failure and cardiac problems. Immediate post-operative complications (mostly haemodynamic) occurred in both cases (emergencyvsroutine surgery,p = 0.018).

Conclusion:

In such cases, pre-operative medical treatment is vital to limit peri- and post-operative complications, but surgery should not be delayed if the haemodynamic status deteriorates. Surgery, with careful anaesthesia, is the cornerstone of the treatment.
Dysponetus joeli sp. nov. (Polychaeta: Chrysopetalidae) from the north-east Atlantic, with a cladistic analysis of the genus and a key to species
Authors: Olivier Frederic , Lana Paulo , Oliveira Veronica , Worsfold Tim
Published: May 2012

We describe Dysponetus joeli sp. nov. from shallow maerl habitats in the north-east Atlantic (English Channel and Bay of Biscay). Dysponetus joeli differs from congeneric species by a unique combination of characters, including a large syllid-like pharynx, 2–4 simple serrated neurochaetae (closely similar to notochaetae, but much smaller and more delicate), D-shaped chaetal spines and ventral cirri on the third segment. A phylogenetic parsimony analysis based on morphological traits suggests that Dysponetus is not monophyletic unless it includes the closely related genera Vigtorniella and Pseudodysponetus, which are well delineated inside the dysponetid clade. Chaetal spines seem to be secondarily derived from paleae and to have originated in infaunal dysponetid forms. They should not be considered as plesiomorphic, but as evidence to support the clade made up by Dysponetus–Vigtorniella and Pseudodysponetus as delineated by a phylogenetic analysis.