bluuebunny/crossref_metadata_2025 huggingface dataset:
D2 Thr92Ala and PPARγ2 Pro12Ala Polymorphisms Interact in the Modulation of Insulin Resistance in Type 2 Diabetic Patients
Authors: Estivalet Aline A.F. , Leiria Leonardo B. , Dora José M. , Rheinheimer Jakeline , Bouças Ana P. , Maia Ana L. , Crispim Daisy
Published: October 2010

Type 2 deiodinase (D2) converts T4 into its active metabolite T3, an essential step in thyroid metabolism. A Thr92Ala polymorphism in the gene encoding D2 has been inconsistently associated with insulin resistance (IR). Recently, it was reported that the D2 Thr92Ala (rs225014) and the peroxisome proliferator‐activated receptor (PPAR) γ2 Pro12Ala (rs1801282) polymorphisms interact in the modulation of metabolic syndrome in nondiabetic subjects. Here, we investigated the effect of both polymorphisms, isolated or in combination, on IR in patients with type 2 diabetes mellitus (DM2). The D2 Thr92Ala and PPARγ2 Pro12Ala polymorphisms were genotyped in 721 DM2 patients. IR was evaluated using the homeostasis model assessment—IR (HOMAIR) index in a subgroup of 246 DM2 subjects. The frequencies of D2 Ala92 and PPARγ2 Ala12 variants were 0.390 and 0.074, respectively. Patients carrying D2 Ala/Ala genotype had a higher fasting plasma insulin and HOMAIR index as compared to patients carrying Thr/Ala or Thr/Thr genotypes (P = 0.022 and P = 0.001, respectively). A significant synergistic effect was observed between D2 Thr92Ala and PPARγ2 Pro12Ala polymorphisms on HOMAIR index, with carriers of both D2 Ala/Ala genotype and PPARγ2 Ala12 allele showing the highest HOMAIR values, after adjusting for age, gender, BMI, and use of medication for DM2 (P = 0.010). In conclusion, DM2 patients harboring both D2 Ala/Ala genotype and PPARγ2 Ala12 allele seem to present more severe IR than those with other D2/PPARγ2 genotype combinations. These findings suggest that these polymorphisms interact in the IR modulation, which may constitute a potential therapeutic target.
A hierarchical classification of polysaccharide lyases for glycogenomics
Authors: Lombard Vincent , Bernard Thomas , Rancurel Corinne , Brumer Harry , Coutinho Pedro M. , Henrissat Bernard
Published: October 2010

Carbohydrate-active enzymes face huge substrate diversity in a highly selective manner using only a limited number of available folds. They are therefore subjected to multiple divergent and convergent evolutionary events. This and their frequent modularity render their functional annotation in genomes difficult in a number of cases. In the present paper, a classification of polysaccharide lyases (the enzymes that cleave polysaccharides using an elimination instead of a hydrolytic mechanism) is shown thoroughly for the first time. Based on the analysis of a large panel of experimentally characterized polysaccharide lyases, we examined the correlation of various enzyme properties with the three levels of the classification: fold, family and subfamily. The resulting hierarchical classification, which should help annotate relevant genes in genomic efforts, is available and constantly updated at the Carbohydrate-Active Enzymes Database (http://www.cazy.org).
My Speech Problem, Your Listening Problem, and My Frustration: The Experience of Living With Childhood Speech Impairment
Authors: McCormack Jane , McLeod Sharynne , McAllister Lindy , Harrison Linda J.
Published: October 2010

Purpose

The purpose of this article was to understand the experience of speech impairment (speech sound disorders) in everyday life as described by children with speech impairment and their communication partners.

Method

Interviews were undertaken with 13 preschool children with speech impairment (mild to severe) and 21 significant others (family members and teachers).

Results

A phenomenological analysis of the interview transcripts revealed 2 global themes regarding the experience of living with speech impairment for these children and their families. The first theme encompassed the problems experienced by participants, namely (a) the child’s inability to “speak properly,” (b) the communication partner’s failure to “listen properly,” and (c) frustration caused by the speaking and listening problems. The second theme described the solutions participants used to overcome the problems. Solutions included (a) strategies to improve the child’s speech accuracy (e.g., home practice, speech-language pathology) and (b) strategies to improve the listener’s understanding (e.g., using gestures, repetition). Both short- and long-term solutions were identified.

Conclusion

Successful communication is dependent on the skills of speakers and listeners. Intervention with children who experience speech impairment needs to reflect this reciprocity by supporting both the speaker and the listener and by addressing the frustration they experience.
Written Language Disorders: Speech-Language Pathologists' Training, Knowledge, and Confidence
Authors: Blood Gordon W. , Mamett Callie , Gordon Rebecca , Blood Ingrid M.
Published: October 2010

Purpose

This study examined speech-language pathologists' (SLPs') perceptions of their (a) educational and clinical training in evaluating and treating written language disorders, (b) knowledge bases in this area, (c) sources of knowledge about written language disorders, (d) confidence levels, and (e) predictors of confidence in working with written language disorders.

Method

A 6-part survey was developed and was mailed to 1,000 school-based SLPs.

Results

SLPs (
n
= 599) practicing in 47 states responded to the survey. A majority (60.3%) reported working with a child with a written language disorder either weekly or daily. SLPs described their educational and clinical training as “limited” in the evaluation and treatment of children with written language disorders. The average SLP stated feeling “somewhat confident” to evaluate and treat written language disorders, and 63.8% reported that they received most of their knowledge through “on-the job” training. Confidence was related to four variables: on-the-job training, general knowledge about written language disorders, attendance at conventions, and understanding of collaborative efforts.

Conclusion

Our findings provide information about SLPs' training, knowledge, and confidence about written language beyond anecdotal reports and fill research gaps regarding SLPs' preservice and professional development needs. Predictors of confidence are discussed.
English Speech Acquisition in 3- to 5-Year-Old Children Learning Russian and English
Authors: Gildersleeve-Neumann Christina E. , Wright Kira L.
Published: October 2010

Purpose

English speech acquisition in Russian–English (RE) bilingual children was investigated, exploring the effects of Russian phonetic and phonological properties on English single-word productions. Russian has more complex consonants and clusters and a smaller vowel inventory than English.

Method

One hundred thirty-seven single-word samples were phonetically transcribed from 14 RE and 28 English-only (E) children, ages 3;3 (years;months) to 5;7. Language and age differences were compared descriptively for phonetic inventories. Multivariate analyses compared phoneme accuracy and error rates between the two language groups.

Results

RE children produced Russian-influenced phones in English, including palatalized consonants and trills, and demonstrated significantly higher rates of trill substitution, final devoicing, and vowel errors than E children, suggesting Russian language effects on English. RE and E children did not differ in their overall production complexity, with similar final consonant deletion and cluster reduction error rates, similar phonetic inventories by age, and similar levels of phonetic complexity. Both older language groups were more accurate than the younger language groups.

Conclusions

We observed effects of Russian on English speech acquisition; however, there were similarities between the RE and E children that have not been reported in previous studies of speech acquisition in bilingual children. These findings underscore the importance of knowing the phonological properties of both languages of a bilingual child in assessment.
Relationship Between Verbal Working Memory and the SCAN–C in Children With Specific Language Impairment
Authors: Lum Jarrad A. G. , Zarafa Michelle
Published: October 2010

Purpose

An ongoing concern with the evaluation of auditory processing disorders is the extent that assessment instruments are influenced by higher order cognitive functions. This study examined the relationship between verbal working memory and performance on the Test for Auditory Processing Disorders in Children—Revised (SCAN–C; Keith, 2000b) in children with specific language impairment (SLI) and typically developing (TD) children.

Method

Sixteen children with SLI and 16 TD children ages 8½ to 11 years participated in the study. The children were presented with the SCAN–C and tests measuring verbal working memory.

Results

Initial comparisons revealed that the SLI group obtained significantly lower scores than the TD group on the SCAN–C. However, after controlling for verbal working memory, significant differences between the 2 groups were no longer observed. Correlational analyses revealed that the composite score from the SCAN–C was related to all tests assessing verbal working memory.

Conclusions

Performance on the SCAN–C may be related to working memory functioning. As a consequence, it is unclear whether difficulty on this task should be viewed as a problem with auditory processing or a problem with verbal working memory.
An upgraded x-ray spectroscopy diagnostic on MST
Authors: Clayton D. J. , Almagri A. F. , Burke D. R. , Forest C. B. , Goetz J. A. , Kaufman M. C. , O’Connell R.
Published: October 2010

An upgraded x-ray spectroscopy diagnostic is used to measure the distribution of fast electrons in MST and to determine Zeff and the particle diffusion coefficient Dr. A radial array of 12 CdZnTe hard-x-ray detectors measures 10–150 keV Bremsstrahlung from fast electrons, a signature of reduced stochasticity and improved confinement in the plasma. A new Si soft-x-ray detector measures 2–10 keV Bremsstrahlung from thermal and fast electrons. The shaped output pulses from both detector types are digitized and the resulting waveforms are fit with Gaussians to resolve pileup and provide good time and energy resolution. Lead apertures prevent detector saturation and provide a well-known etendue, while lead shielding prevents pickup from stray x-rays. New Be vacuum windows transmit >2 keV x-rays, and additional Al and Be filters are sometimes used to reduce low energy flux for better resolution at higher energies. Measured spectra are compared to those predicted by the Fokker–Planck code CQL3D to deduce Zeff and Dr.
Synchronization of Thomson scattering measurements on MAST using an FPGA based “Smart” trigger unit
Authors: Naylor G.
Published: October 2010

The MAST Thomson scattering diagnostic has recently been upgraded to make electron density and temperature measurements at 130 points across the 1.5 m diameter of the plasma. The new system is able to take 240 measurements per second using eight Nd:YAG lasers, each running at 30 Hz. The exact firing time of these lasers is adjusted with 100 ns precision using a field programmable gate array based trigger unit. Trigger pulses are produced to fire the lamps of all lasers and the Q switches with the appropriate delay depending on the warm-up status. The lasers may be fired in rapid bursts so as to achieve a high temporal resolution over eight points separated down to the microsecond level. This trigger unit receives optical trigger events and signals from external sources, allowing the trigger sequences to be resynchronized to the start of the plasma pulse and further events during the shot such as the entry of a fuelling pellet or randomly occurring plasma events. This resynchronization of the laser firing sequence allows accurate and reproducible measurements of fast plasma phenomena.
Enhanced perpendicular magnetic anisotropy in Co/Ni multilayers with a thin seed layer
Authors: Kurt H. , Venkatesan M. , Coey J. M. D.
Published: October 2010

Perpendicular magnetic anisotropy (PMA) is induced in Co/Ni multilayers when they are grown on a (111) textured Au seed layer, provided it is at least 2 nm thick. The anisotropy increases with increasing Au thickness due to improved crystallinity. Postannealing treatments of as-grown [Co(0.3)/Ni(0.6)]5 (thicknesses in nanometer) multilayers enhance the coercivity and PMA up to an annealing temperature of 250 °C, but higher temperatures lead to intermixing of Co and Ni which diminishes PMA. The easy axis becomes in-plane for samples annealed at 400 °C. The improvement in PMA in Co/Ni layers due to annealing is limited by the Au seed layer thickness. Annealing also reduces the saturation magnetization by ∼15% due to the formation of superparamagnetic islands. Our results show that the PMA in Co/Ni multilayers can be improved by annealing up to 350 °C, which is required for the thermal stability of spin transfer torque memories.
Small amplitude nonlinear electrostatic waves in a collisional complex plasma with positively charged dust
Authors: Fedila D. Ali , Djebli M.
Published: October 2010

The effect of collision on small amplitude dust-acoustic waves is investigated for a plasma with positively charged dust grains. Taking into account the presence of different electron populations in thermal equilibrium, a modified Korteweg–de Vries equation is established. The existence conditions and nature of the waves, i.e., rarefactive or compressive, are found to be mainly dependent on the temperature and the density of the cold electrons. The present model is used to understand the salient features of the fully nonlinear dust-acoustic waves in the lower region of the Earth’s ionosphere, at an altitude of ∼85 km with the presence of an external heating source.
DNA detection using a complementary metal-oxide semiconductor ring oscillator circuit
Authors: Kocanda Martin , Abdel-Motaleb Ibrahim
Published: October 2010

A DNA detection scheme has been implemented that utilizes a simple complementary metal-oxide semiconductor (CMOS) ring oscillator circuit. The detector oscillates at a fundamental frequency when using a nonhybridized single-strand DNA probe layer. Upon hybridization with a complimentary DNA strand, the oscillator output exhibits an increased frequency shift, indicating a genetic match. The probe assembly consists of a p-GaAs substrate containing a pulsed laser deposition-applied barium strontium titanate layer and an overlying sodium dodecyl sulfate lipid layer that serves to anchor a functionalized oligonucleotide probe. The oscillator circuit consisting of cascaded discrete complimentary n-channel and p-channel metal-oxide-semiconductor field-effect transistors was implemented using passive components arranged in a T-network to provide the associated fundamental time constant.
Molecular aniline clusters. II. The low-lying electronic excited states
Authors: Schemmel Dominik , Schütz Martin
Published: October 2010

The lowest electronically excited states of the aniline dimer and trimer related to the lowest π∗←π transition of the monomer are investigated by applying time-dependent coupled cluster theory, primarily at the level of the (spin-component-scaled) CC2 model. Minimum energy structures in the vicinity of the Franck–Condon points were determined on the individual potential energy surfaces. For the dimer we find an excimer and a head-to-tail configuration (with the monomers substantially displaced relative to the ground state minimum) for the lowest (dark) and second lowest (bright) states, respectively. The excitation is delocalized on both chromophores for both of these states. For the trimer three distinct minima with quite different hydrogen-bonding arrangements are found for the three lowest states. In strong contrast to the dimer the excitation here is clearly localized on the individual aniline chromophores for each of these three states. One of the three geometries is rather similar to the ground state minimum, while the two others are rather different and thus have presumably quite small Franck–Condon factors. It can be expected that only the electronic origin of the first conformer can eventually be detected in the absorption spectrum of the trimer, provided that it is separated by high-enough barriers from other, energetically lower configurations.
Structural and magnetic phase diagrams of epitaxial Cr–Mn alloy thin films
Authors: Feng Wuwei , Choi Jeongyong , Dung Dang Duc , Cho Sunglae , Hao Xian
Published: October 2010

We report here a systematic study of Cr–Mn alloy films that have been epitaxially stabilized on GaSb (100) using molecular beam epitaxy. The crystal structural transition between the α-Cr-type and the α-Mn-type for the Cr–Mn alloy films is observed along with changes in growth temperature, film thickness, and the ratio of Cr to Mn. Ferrimagnetism is observed in the Cr–Mn films containing the α-Mn-type phase based on the magnetic field-dependent anomalous Hall effect hysteresis and is corroborated by the magnetization hysteresis. The α-Mn-type CrMn phase at the expanded lattice parameter induces the observed ferrimagnetic ordering. The magnetic moments of Cr–Mn films can be tuned by adjusting the growth temperature, film thickness, and the ratio of Cr to Mn. Eventually, new structural and magnetic phase diagrams of the epitaxial Cr–Mn alloy films are established. The results of this study can prove helpful in both forming a comprehensive understanding of Cr–Mn alloys and in finding new applications for it in spintronic devices.
Spectral theory of semibounded Sturm–Liouville operators with local interactions on a discrete set
Authors: Albeverio Sergio , Kostenko Aleksey , Malamud Mark
Published: October 2010

We study the Hamiltonians HX,α,q with δ-type point interactions at the centers xk on the positive half line in terms of energy forms. We establish analogs of some classical results on operators Hq=−d2/dx2+q with locally integrable potentials q∊Lloc1(R+). In particular, we prove that the Hamiltonian HX,α,q is self-adjoint if it is lower semibounded. This result completes the previous results of Brasche [“Perturbation of Schrödinger Hamiltonians by measures—selfadjointness and semiboundedness,” J. Math. Phys. 26, 621 (1985)] on lower semiboundedness. Also we prove the analog of Molchanov’s discreteness criteria, Birman’s result on stability of a continuous spectrum, and investigate discreteness of a negative spectrum. In the recent paper [Kostenko, A. and Malamud, M., “1–D Schrödinger operators with local point interactions on a discrete set,” J. Differ. Equations 249, 253 (2010)], it was shown that the spectral properties of HX,α≔HX,α,0 correlate with the corresponding spectral properties of a certain class of Jacobi matrices. We apply the above mentioned results to the study of spectral properties of these Jacobi matrices.
Enhancement of thermoelectric efficiency in type-VIII clathrate Ba8Ga16Sn30 by Al substitution for Ga
Authors: Deng Shukang , Saiga Yuta , Suekuni Koichiro , Takabatake Toshiro
Published: October 2010

Single-crystalline samples of type-VIII clathrate Ba8Ga16−xAlxSn30 (0≤x≤12) were grown from Sn flux to characterize the structural and thermoelectric properties from 300 to 600 K. The lattice parameter increases by 0.5% as x is increased to 10.5 whose value is the solubility limit of Al. The Seebeck coefficients of all samples are largely negative and the absolute values increase to approximately 300 μV/K on heating to 600 K. This large thermopower coexists with the metallic behavior in the electrical resistivity. The values of resistivity for 1≤x≤6 at 300 K are in the range 3.3–3.8 mΩ cm which is 70% of that for x=0. As a result, the power factor for x=4 and 6 has a rather large maximum of 1.83×10−3 W/m K2 at 480 K. The thermal conductivity stays at a low level of 0.72 W/mK up to 480 K, and the sample with x=6 reaches a ZT value of 1.2 at 500 K.
Merging of magnetic islands as an efficient accelerator of electrons
Authors: Tanaka Kentaro G. , Yumura Tsubasa , Fujimoto Masaki , Shinohara Iku , Badman Sarah V. , Grocott Adrian
Published: October 2010

In a thin elongated current sheet, it is likely that more than one X-line forms and thus multiple magnetic islands are produced. The islands are then subject to merging. By simulating such a case with a two-dimensional full-particle code, we show that a merger forming a large island produces the most energetic electron population in the system. By setting the lateral extent of the simulation box to be as large as ∼100 ion inertial lengths, we introduce many (16) small islands in the initial thin current sheet (∼1 ion inertial length thickness). Merging of these islands proceeds to leave only two islands in the system. Then, strong electron acceleration is seen upon the final merger that produces the single island in the large simulation box. The most energetic electrons in the system are accelerated at the merging line. The merging line acceleration dominates because the reverse-reconnection facilitating the final merger is in such a strongly driven manner that the associated electric field is an order of magnitude larger than those available upon normal reconnection. Combining the results from additional runs enables us to obtain a scaling law, which suggests a non-negligible role played by merging lines in the observed electron acceleration phenomena.
Deformations of Maxwell superalgebras and their applications
Authors: Bonanos Sotirios , Gomis Joaquim , Kamimura Kiyoshi , Lukierski Jerzy
Published: October 2010

We describe the Lie algebra deformations of D=4 Maxwell superalgebra that was recently introduced as the symmetry algebra of a kappa-symmetric massless superparticle in a supersymmetric constant electromagnetic backgrounds. Further we introduce the D=3 Maxwell superalgebra and present all its possible deformations. Finally, the deformed superalgebras are used to derive via a contraction procedure the complete set of Casimir operators for D=4 and D=3 Maxwell superalgebras.
Tuning of the metal-insulator transition in electrolyte-gated NdNiO3 thin films
Authors: Asanuma S. , Xiang P.-H. , Yamada H. , Sato H. , Inoue I. H. , Akoh H. , Sawa A. , Ueno K. , Shimotani H. , Yuan H. , Kawasaki M. , Iwasa Y.
Published: October 2010

We demonstrate electrostatic control of the metal-insulator transition in the typical correlated-electron material NdNiO3 through a large effective capacitance of the electric double layer at the electrolyte/NdNiO3 interface. The metal-insulator transition temperature (TMI) of NdNiO3 is shown to decrease drastically with increasing hole concentration through the application of a negative gate voltage (VG). The shift in TMI (|ΔTMI|) is larger for thinner NdNiO3; for VG of −2.5 V, |ΔTMI| of 5-nm-thick NdNiO3 is as large as 40 K, and the resistivity change near 95 K is one order of magnitude. This study may be potentially applicable to Mott transistor devices.
Oxygen defects-modulated green photoluminescence of Tb-doped ZrO2 nanofibers
Authors: Xie Yizhu , Ma Ziwei , Liu Lixin , Su Yuroug , Zhao Haiting , Liu Yanxia , Zhang Zhenxing , Duan Huigao , Li Jian , Xie Erqing
Published: October 2010

The photoluminescence properties of Tb-doped ZrO2 nanofibers synthesized by electrospinning technique were investigated. The intensity of the green light emission could be controlled by oxygen vacancy concentration, which could be enhanced by argon gas annealing or diminished by oxygen annealing. An energy transfer mechanism is proposed that the oxygen vacancies in the host acted as effective sensitizers for the adjacent Tb ions. The oxygen vacancies transferred excitation energy to the adjacent Tb ions sites and thus greatly enhanced the green emission. These results are of great importance for the future optoelectronic applications of Tb-doped ZrO2 nanofibers.
Italy: reformers without reforms?
Authors: Bull Anna Cento , Gardini Gian Luca
Published: October 2010

At the end of 2009, Prime Minister Silvio Berlusconi announced that 2010 would be the year of reforms in Italy (Il Sole 24 Ore, 26 December 2009). Indeed Mr Berlusconi and the question of institutional reforms have been the crucial elements of Italian political discourse and debate in recent years. However, while much has been said and written about the former, a number of key questions still beg to be answered about the latter. First of all, what reforms are we talking about? Are these a specific package of institutional engineering or are they, rather, an eye-catching and consensus-building yet still diffused set of aspirations? In either case, what vision of twenty-first-century Italy do they reflect or propose? Is there consensus enough – within and across parliamentary coalitions – on what the priorities ought to be and how they should be tackled?
That dangerous serpent: Garibaldi and Ireland 1860–1870
Authors: O'Connor Anne
Published: October 2010

This article analyses the reaction to Garibaldi in Ireland during the Risorgimento, a reaction which, in its negativity, generally contrasted with the Italian's heroic depiction elsewhere. Attitudes towards Garibaldi reflected existing religious divisions in Ireland, with Protestants supporting him and Catholics condemning his actions in Italy. The study examines ballads, pamphlets and newspapers to illustrate the pro-papal fervour felt in Ireland and the strength of anti-Garibaldi feelings. The decision of Irishmen to form a battalion to fight in defence of the Papal States in 1860 reveals that, ultimately, denigration of Garibaldi became a badge of Irish nationalism. The study highlights the position of Britain in understanding the relationship between Ireland and Italy in these years, pointing out Irish nationalists’ bafflement over Britain's support for Italian unification while it denied similar rights to Irish subjects. The article demonstrates how, in this context, domestic and tactical considerations coloured responses to Garibaldi in Ireland, with Irish issues projected onto the Italian situation, thus leading to entrenched and extreme attitudes towards the Italian soldier.
Critical Gaps in Knowledge of the Epidemiology and Pathophysiology of Healthcare-Associated Infections
Authors: Henderson David K. , Palmore Tara N.
Published: October 2010

The past decade has witnessed an intense interest in healthcare-associated infections as well as increases in legislation and reporting requirements aimed at decreasing the number of these costly infections. In the next decade, healthcare epidemiology must address major gaps in understanding of the epidemiology and pathogenesis of healthcare-associated infections and in knowledge of the efficacy of interventions for healthcare-associated infections and the efficacy in implementing such interventions.
Prevention of Healthcare-Associated Clostridium difficile Infection: What Works?
Authors: Dubberke Erik R.
Published: October 2010

Prevention of Clostridium difficile infection has become extremely important because of increases in its incidence and severity. Unfortunately, efforts at C. difficile infection prevention are hampered by lack of data to support optimal prevention methods, especially for endemic C. difficile infection. Studies are needed to define the optimal prevention practices and to investigate novel prevention methods.
The Past, Present, and Future of Healthcare-Associated Infection Prevention in Pediatrics: Viral Respiratory Infections
Authors: Zerr Danielle M. , Milstone Aaron M. , Huskins W. Charles , Bryant Kristina A.
Published: October 2010

Viral respiratory infections pose a significant challenge to pediatric infection prevention programs. We explore issues regarding the prevention of viral respiratory infections by discussing transmission of influenza A virus, isolation of infected patients, and hospital programs for influenza vaccination.
Global Epidemiology ofClostridium difficileInfection in 2010
Authors: Gerding Dale N.
Published: October 2010

The past decade has been characterized by an epidemic ofClostridium difficileinfection in North America and Europe that threatens to extend to the rest of the world. The epidemic is due in part to the emergence of a previously rare and now more lethalC. difficilestrain variously named group BI, ribotype 027, and North American pulsed-field gel electrophoresis type 1.
The Past, Present, and Future of Healthcare-Associated Infection Prevention in Pediatrics: Multidrug-Resistant Organisms
Authors: Milstone Aaron M. , Bryant Kristina A. , Huskins W. Charles , Zerr Danielle M.
Published: October 2010

Multidrug resistant organisms (MDROs) and healthcare-associated infections (HAIs) are associated with increased lengths of hospital stay, increased costs, and increased mortality. We explore the scope of MDRO HAIs in children, current MDRO HAI prevention practices and data to support these practices, and we propose research topics targeting MDRO HAI prevention in children.
Solution-processed hybrid bilayer photodetectors with rapid response to ultraviolet radiation
Authors: Li Haiguo , Fan Congcheng , Wu Gang , Chen Hongzheng , Wang Mang
Published: October 2010

Two hybrid bilayer ultraviolet photodetectors have been fabricated by spin-coating with poly(9,9-dihexylfluorene) (PFH) and ZnO nanoparticles as electron donor and acceptor, respectively. The device structure is inverted for device A: indium tin oxide (ITO)/ZnO/PFH/Au, while for device B a normal structure is applied: ITO/PFH/ZnO/Al. Both devices exhibit obvious photoresponse with a photo-to-dark current ratio of 3–4 orders of magnitude under UV radiation of 1 mW cm−2 at 365 nm through the ITO electrode. Under reverse bias, the photoresponse of device A exhibits severe persistent photoconduction. However, this is efficiently avoided in device B due to the presence of sufficient oxygen to capture the free electrons in ZnO. The study shown here may provide a useful guideline to achieve low-cost hybrid UV detectors with rapid response.
Hepatocyte Growth Factor Inhibits Apoptosis by the Profibrotic Factor Angiotensin II via Extracellular Signal-regulated Kinase 1/2 in Endothelial Cells and Tissue Explants
Authors: Lee Young H. , Marquez Ana P. , Mungunsukh Ognoon , Day Regina M.
Published: October 2010

Hepatocyte growth factor (HGF), an endogenous tissue repair factor, attenuates apoptosis in many primary cell types, but the mechanism is not completely understood. Our laboratory demonstrated that angiotensin (Ang) II activates the intrinsic apoptotic pathway in primary endothelial cells (ECs) via reduction of the antiapoptotic protein Bcl-xL. Ang II decreased Bcl-xLmRNA half-life by reducing its binding to nucleolin, a protein that normally binds a 3′ AU-rich region and stabilizes Bcl-xLmRNA. We hypothesized HGF may block apoptosis induced by Ang II. We used primary EC and ex vivo cultures of rat lung tissue to investigate HGF inhibition of Ang II-induced apoptosis. Our data indicated HGF abrogated Ang II-induced apoptosis by inhibiting cytochrome c release, caspase-3 activation, and DNA fragmentation. RNA-immunoprecipitation experiments demonstrated that HGF stabilized Bcl-xLmRNA by increasing nucleolin binding to the 3′-untranslated region that was associated with cytoplasmic localization of nucleolin. Cytoplasmic localization of nucleolin and Bcl-xLmRNA stabilization required HGF activation of extracellular signal-regulated kinase (ERK)1/2, but not phosphatidylinositol 3-kinase. HGF also blocked Ang II-induced caspase-3 activation and lactate dehydrogenase release in tissue explants in an ERK-dependent manner.
β1A Integrin Is a Master Regulator of Invadosome Organization and Function
Authors: Destaing Olivier , Planus Emmanuelle , Bouvard Daniel , Oddou Christiane , Badowski Cedric , Bossy Valentine , Raducanu Aurelia , Fourcade Bertrand , Albiges-Rizo Corinne , Block Marc R.
Published: October 2010

Invadosomes are adhesion structures involved in tissue invasion that are characterized by an intense actin polymerization–depolymerization associated with β1 and β3 integrins and coupled to extracellular matrix (ECM) degradation activity. We induced the formation of invadosomes by expressing the constitutive active form of Src, SrcYF, in different cell types. Use of ECM surfaces micropatterned at the subcellular scale clearly showed that in mesenchymal cells, integrin signaling controls invadosome activity. Using β1−/−or β3−/−cells, it seemed that β1A but not β3 integrins are essential for initiation of invadosome formation. Protein kinase C activity was shown to regulate autoassembly of invadosomes into a ring-like metastructure (rosette), probably by phosphorylation of Ser785 on the β1A tail. Moreover, our study clearly showed that β1A links actin dynamics and ECM degradation in invadosomes. Finally, a new strategy based on fusion of the photosensitizer KillerRed to the β1A cytoplasmic domain allowed specific and immediate loss of function of β1A, resulting in disorganization and disassembly of invadosomes and formation of focal adhesions.
Vav3 Is Involved in GABAergic Axon Guidance Events Important for the Proper Function of Brainstem Neurons Controlling Cardiovascular, Respiratory, and Renal Parameters
Authors: Sauzeau Vincent , Horta-Junior José A. C. , Riolobos Adelaida S. , Fernández Gloria , Sevilla María A. , López Dolores E. , Montero María J. , Rico Beatriz , Bustelo Xosé R.
Published: October 2010

Vav3 is a phosphorylation-dependent activator of Rho/Rac GTPases that has been implicated in hematopoietic, bone, cerebellar, and cardiovascular roles. Consistent with the latter function, Vav3-deficient mice develop hypertension, tachycardia, and renocardiovascular dysfunctions. The cause of those defects remains unknown as yet. Here, we show that Vav3 is expressed in GABAegic neurons of the ventrolateral medulla (VLM), a brainstem area that modulates respiratory rates and, via sympathetic efferents, a large number of physiological circuits controlling blood pressure. On Vav3 loss, GABAergic cells of the caudal VLM cannot innervate properly their postsynaptic targets in the rostral VLM, leading to reduced GABAergic transmission between these two areas. This results in an abnormal regulation of catecholamine blood levels and in improper control of blood pressure and respiration rates to GABAergic signals. By contrast, the reaction of the rostral VLM to excitatory signals is not impaired. Consistent with those observations, we also demonstrate that Vav3 plays important roles in axon branching and growth cone morphology in primary GABAergic cells. Our study discloses an essential and nonredundant role for this Vav family member in axon guidance events in brainstem neurons that control blood pressure and respiratory rates.
Hydroxyethyl Starch 6% (130/0.4) Ameliorates Acute Lung Injury in Swine Hemorrhagic Shock
Authors: Balkamou Xanthippi , Xanthos Theodoros , Stroumpoulis Konstantinos , Moutzouris Dimitrios-Anestis , Rokas Georgios , Agrogiannis Georgios , Demestiha Theano , Patsouris Efstathios , Papadimitriou Lila
Published: October 2010

Background

Traumatic hemorrhage induces acute lung injury. The aim of this study was to assess whether lactated Ringer's solution or 6% hydroxyethyl starch 130/0.4 would have different effects on acute lung injury following hemorrhagic shock.

Methods

Twenty healthy pigs (19 ± 2 kg) were subjected to hemorrhage and were randomly allocated to two groups: Group A (10 pigs) who received lactated Ringer's solution and Group B (10 pigs) who received hydroxyethyl starch 130/0.4. Hemodynamic response and serum lactate were measured at predetermined phases. Four hours after fluid resuscitation animals were euthanized. Lungs were harvested, and tissue samples were collected. Focal thickening of the alveolar membranes, vascular congestion, number of activated neutrophils, alveolar edema, interstitial neutrophil infiltration, intraalveolar infiltration, and alveolar hemorrhage were assessed. Each feature was given a score from 0 to 3 (0 = absence, 3 = severe). The wet/dry ratio was also calculated, and with the use of Evans blue dye extravasation method, capillary permeability was assessed.

Results

The total histology score of Group A differed significantly from that of Group B, being significantly lower in Group B animals P = 0.048. The wet/dry weight ratio was significantly higher in the lactated Ringer's group (median [range]) (Group A, 5.1 [0.5]; Group B, 4.9 [0.3]; P = 0.009). The Evans blue dye extravasation method was utilized to study the lung capillary permeability. The animals in Group B showed a marked reduction in microvascular capillary permeability compared with the animals in Group A (Group A, 58.5 [21] mg/g; Group B, 51.5 [14] mg/g; P = 0.017).

Conclusions

Our study indicates that resuscitation after hemorrhagic shock with hydroxyethyl starch 130/0.4 led to less lung edema and less microvascular permeability in this swine model.
Effect of Anesthetic Technique on Serum Vascular Endothelial Growth Factor C and Transforming Growth Factor β in Women Undergoing Anesthesia and Surgery for Breast Cancer
Authors: Looney Micheal , Doran Peter , Buggy Donal J.
Published: October 2010

Background

In breast cancer, vascular endothelial growth factor C, transforming growth factor β, placental growth factor, and fibroblast growth factor (acidic and basic) promote angiogenesis and metastases. We tested the hypothesis that a propofol-paravertebral anesthetic (PPA) technique would attenuate postoperative changes in these angiogenic factors to a greater extent than balanced general anesthesia (GA) and morphine analgesia in women undergoing surgery for primary breast cancer.

Method

Forty women with primary breast cancer undergoing surgical excision were randomized to receive either standard GA or PPA technique. Venous blood was sampled before and at 24 h after surgery and serum analyzed. The primary endpoint was a preoperative versus postoperative change in vascular endothelial growth factor C and transforming growth factor β concentrations.

Results

Using a visual analog scale (median [25-75% interquartile range]), PPA patients (1 [0-2]) had less pain at 2 h (P = 0.02) than did GA patients (3 [2-5]). The mean postoperative change in vascular endothelial growth factor C concentrations among GA patients was 733 versus 27 pg/ml for PPA patients (difference, 706 [97.5% CI, 280-1,130] pg/ml, P = 0.001). In contrast, the mean postoperative change in transforming growth factor β concentration among GA patients was -163 versus 146 pg/ml for PPA patients (difference, 309 [97.5% CI, -474 to -143] pg/ml, P = 0.005). Concentrations of placental growth factor and fibroblast growth factor, both acidic and basic, were undetectable in serum.

Conclusion

Anesthetic technique influences serum concentrations of factors associated with angiogenesis in primary breast cancer surgery.
The helicity and vorticity of liquid-crystal flows
Authors: Gay-Balmaz François , Tronci Cesare
Published: October 2010

We present explicit expressions of the helicity conservation in nematic liquid-crystal flows, for both the Ericksen–Leslie and Landau–de Gennes theories. This is done by using a minimal coupling argument that leads to an Euler-like equation for a modified vorticity involving both velocity and structure fields (e.g. director and alignment tensor). This equation for the modified vorticity shares many relevant properties with ideal fluid dynamics, and it allows for vortex-filament configurations, as well as point vortices, in two dimensions. We extend all these results to particles of arbitrary shape by considering systems with fully broken rotational symmetry.
Waves and damage in structured solids with multi-scale resonators
Authors: Jones I. S. , Movchan A. B. , Gei M.
Published: October 2010

This paper presents asymptotic and numerical modelling of elastic waves interacting with micro-structured solids containing multi-scale resonators. The resonators may be damaged by transverse cracks at their foundations. One particular feature of the resonators used here is the presence of low-frequency eigenmodes. Asymptotic estimates of low eigenfrequencies are included in the model. Hence, the overall periodic structure containing such resonators may support low-frequency standing waves and possess low-frequency stop bands. The analytical model is accompanied by numerical simulations illustrating dispersion, localization and focusing within the structured multi-scale solids.
Asymptotic estimates for Stieltjes constants: a probabilistic approach
Authors: Adell José A.
Published: October 2010

Let (
γ

n

)

n
≥ 0

be the sequence of Stieltjes constants appearing in the Laurent expansion of the Riemann zeta function. We obtain explicit upper bounds for |
γ

n

|, whose order of magnitude is

as
n
tends to infinity. To do this, we use a probabilistic approach based on a differential calculus for the gamma process.
Macromolecular crystallography at synchrotron radiation sources: current status and future developments
Authors: Duke E. M. H. , Johnson L. N.
Published: October 2010

X-ray diffraction with synchrotron radiation (SR) has revealed the atomic structures of numerous biological macromolecules including proteins and protein complexes, nucleic acids and their protein complexes, viruses, membrane proteins and drug targets. The bright SR X-ray beam with its small divergence has made the study of weakly diffracting crystals of large biological molecules possible. The ability to tune the wavelength of the SR beam to the absorption edge of certain elements has allowed anomalous scattering to be exploited for phase determination. We review the developments at synchrotron sources and beamlines from the early days to the present time, and discuss the significance of the results in providing a deeper understanding of the biological function, the design of new therapeutic molecules and time-resolved studies of dynamic events using pump–probe techniques. Radiation damage, a problem with bright X-ray sources, has been partially alleviated by collecting data at low temperature (100 K) but work is ongoing. In the most recent development, free electron laser sources can offer a peak brightness of hard X-rays approximately 10
8
times brighter than that achieved at SR sources. We describe briefly how early experiments at FLASH and Linear Coherent Light Source have shown exciting possibilities for the future.
Experimental peripheral administration of oxytocin elevates a suite of cooperative behaviours in a wild social mammal
Authors: Madden Joah R. , Clutton-Brock Tim H.
Published: October 2010

The evolution and expression of different forms of cooperative behaviour (e.g. feeding, guarding, sentinel duties, etc.) are usually studied independently, with few studies considering them as a single syndrome. However, studies investigating individuals' investment across a suite of different behaviours reveal that they are correlated, suggesting a single mechanism determining the evolution and expression of cooperative behaviours. A hormonal mechanism could achieve this, and one possibility is oxytocin (OT), which affects several prosocial or alloparental behaviours independently. We show, using a double-blind experiment, that peripheral administration of OT to social, free-living meerkats
Suricata suricatta
elevates a suite of cooperative behaviours. Treated individuals increase their contributions to communal, cooperative activities (digging, guarding, pup-feeding and associating with pups) and decrease initiation of aggressive interactions, compared with a saline control. This suggests that different forms of cooperative behaviour form a single syndrome with a common causal basis. If our peripherally administered OT acts in the same way as the naturally released hormone, then a general tendency to prosociality may be modulated by this hormonal system. Therefore, it may be difficult for an individual to decouple expression of cooperative behaviours that provide the practitioner with benefits from those that provide the recipient with benefits. It may also explain why social species typically exhibit a suite of cooperative behaviours, without having to invoke independent evolution of each.
Convergent evolution of kin-based sociality in a lizard
Authors: Davis Alison R. , Corl Ammon , Surget-Groba Yann , Sinervo Barry
Published: October 2010

Studies of social birds and mammals have produced extensive theory regarding the formation and dynamics of kin-based social groups in vertebrates. However, comparing kin dynamics in birds and mammals to social reptiles provides the opportunity to identify selective factors that promote independent origins of kin sociality across vertebrates. We combined a 5-year mark-recapture study with a DNA microsatellite analysis of relatedness in a social lizard (Xantusia vigilis) to examine the formation and stability of kin groups. We found that these lizards are highly sedentary and that groups often form through the delayed dispersal of offspring. Groups containing juveniles had higher relatedness than adult-only groups, as juveniles were commonly found in aggregations with at least one parent and/or sibling. Groups containing nuclear family members were more stable than groups of less-related lizards, as predicted by social theory. We conclude thatX. vigilisaggregations conform to patterns of kin sociality observed in avian and mammalian systems and represent an example of convergent evolution in social systems. We suggest that kin-based sociality in this and other lizards may be a by-product of viviparity, which can promote delayed juvenile dispersal by allowing prolonged interaction between a neonate and its mother.
A Gain-of-Function Mutation of Arabidopsis CRYPTOCHROME1 Promotes Flowering
Authors: Exner Vivien , Alexandre Cristina , Rosenfeldt Gesa , Alfarano Pietro , Nater Mena , Caflisch Amedeo , Gruissem Wilhelm , Batschauer Alfred , Hennig Lars
Published: October 2010

Plants use different classes of photoreceptors to collect information about their light environment. Cryptochromes are blue light photoreceptors that control deetiolation, entrain the circadian clock, and are involved in flowering time control. Here, we describe the cry1-L407F allele of Arabidopsis (Arabidopsis thaliana), which encodes a hypersensitive cryptochrome1 (cry1) protein. Plants carrying the cry1-L407F point mutation have elevated expression of CONSTANS and FLOWERING LOCUS T under short-day conditions, leading to very early flowering. These results demonstrate that not only the well-studied cry2, with an unequivocal role in flowering promotion, but also cry1 can function as an activator of the floral transition. The cry1-L407F mutants are also hypersensitive toward blue, red, and far-red light in hypocotyl growth inhibition. In addition, cry1-L407F seeds are hypersensitive to germination-inducing red light pulses, but the far-red reversibility of this response is not compromised. This demonstrates that the cry1-L407F photoreceptor can increase the sensitivity of phytochrome signaling cascades. Molecular dynamics simulation of wild-type and mutant cry1 proteins indicated that the L407F mutation considerably reduces the structural flexibility of two solvent-exposed regions of the protein, suggesting that the hypersensitivity might result from a reduced entropic penalty of binding events during downstream signal transduction. Other nonmutually exclusive potential reasons for the cry1-L407F gain of function are the location of phenylalanine-407 close to three conserved tryptophans, which could change cry1’s photochemical properties, and stabilization of ATP binding, which could extend the lifetime of the signaling state of cry1.