bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of the shielding cylinder and substrate on the characteristics of an argon radio-frequency atmospheric glow discharge plasma jet
Authors: Li Guo , Le Pei-Si , Li He-Ping , Bao Cheng-Yu
Published: May 2010

With unique features of low breakdown voltages, large and uniform discharge areas and high concentrations of chemically reactive species, radio-frequency, atmospheric-pressure glow discharge (rf APGD) plasma sources produced with bare-metallic electrodes have shown promising prospects in the field of materials processing. In this paper, the spatial distributions (i.e., the directly measured integrated axial distribution and the radial distribution by using the inverse Abel transform) of the emission intensities of the Ar I 696.5 nm line are studied for the argon rf APGD plasma jet under different operation conditions, including variations of the rf power input or the argon flow rate, the existence of the solid shielding cylinder or the substrate. The experimental results show that, with other parameters being unchanged, the emission intensities of the Ar I 696.5 nm line increase with increasing the rf power input or the argon flow rate; and the solid shielding cylinder has more significant influences on the characteristics of the plasma impinging jet by reducing the mass flow rate of the ambient air entrained into the plasma jet region than those for the cases without the existence of the substrate at the downstream of the plasma torch nozzle exit.
Schottky barrier height behavior of Pt–Ru alloy contacts on single-crystal n-ZnO
Authors: Nagata T. , Volk J. , Haemori M. , Yamashita Y. , Yoshikawa H. , Hayakawa R. , Yoshitake M. , Ueda S. , Kobayashi K. , Chikyow T.
Published: May 2010

We investigated the Schottky barrier height (SBH) behavior of binary alloy Schottky contacts on n-type zinc oxide (n-ZnO) single crystals. Pt–Ru alloy electrodes were deposited on the Zn-polar and O-polar faces of ZnO substrates by combinatorial ion-beam deposition under identical conditions. The crystal structures of the Pt–Ru alloy film changed from the Pt phase (cubic structure) to the Ru phase (hexagonal structure) in the Pt–Ru alloy phase diagram with decreasing Pt content. The SBH, determined from current–voltage measurements, decreased with decreasing Pt content, indicating that the SBH behavior also followed the Pt–Ru alloy phase diagram. The alloy electrodes on the Zn-polar face showed better Schottky properties than those on the O-polar face. Hard x-ray photoelectron spectroscopy revealed a difference in the interface oxidization of the Pt–Ru alloy: the interface of the O-polar face and Pt–Ru mixed phase with poor crystallinity had a more oxidized layer than that of the Zn-polar face. As a result of this oxidization, the O-polar face, Pt–Ru mixed, and Ru phases showed poor Schottky properties.
Ultrafast and ultraslow proton transfer of pyranine in an ionic liquid microemulsion
Authors: Sen Mojumdar Supratik , Mondal Tridib , Das Atanu Kumar , Dey Shantanu , Bhattacharyya Kankan
Published: May 2010

Effect of a room temperature ionic liquid (RTIL) and water on the ultrafast excited state proton transfer (ESPT) of pyranine (8-hydroxypyrene-1,3,6-trisulfonate, HPTS) inside a microemulsion is studied by femtosecond up-conversion. The microemulsion consists of the surfactant, triton X-100 (TX-100) in benzene (bz) and contains the RTIL, 1-pentyl-3-methyl-imidazolium tetrafluoroborate ([pmim] [BF4]) as the polar phase. In the absence of water, HPTS undergoes ultrafast ESPT inside the RTIL microemulsion (RTIL/TX-100/bz) and the deprotonated form (RO−) exhibits three rise components of 0.3, 14, and 375 ps. It is proposed that in the RTIL microemulsion, HPTS binds to the TX-100 at the interface region and participates in ultrafast ESPT to the oxygen atoms of TX-100. On addition of water an additional slow rise of 2150 ps is observed. Similar long rise component is also observed in water/TX-100/benzene reverse micelle (in the absence of [pmim] [BF4]). It is suggested that the added water molecules preferentially concentrate (trapped) around the palisade layer of the RTIL microemulsion. The trapped water molecules remain far from the HPTS both in the presence and absence of ionic liquid and gives rise to the slow component (2150 ps) of ESPT. Replacement of H2O by D2O causes an increase in the time constant of the ultraslow rise to 2350 ps.
Enhancement of ultraviolet electroluminescence based on n-ZnO/n-GaN isotype heterojunction with low threshold voltage
Authors: Li Songzhan , Fang Guojia , Long Hao , Mo Xiaoming , Huang Huihui , Dong Binzhong , Zhao Xingzhong
Published: May 2010

Ultraviolet light-emitting diodes based on simple n-ZnO/n-GaN isotype heterojunction have been fabricated using a radio frequency magnetron sputtering system. Ultraviolet emission peaking around ∼368 nm with a full-width at half maximum of ∼7 nm was observed at room temperature when the devices were under sufficient forward bias. With the presence of an i-MgO layer inserted between the ZnO and GaN layers, the ultraviolet emission intensity and output power have been much enhanced, while the threshold voltage drops down to 2.5 V. The electroluminescence mechanisms in these devices were discussed in terms of the band diagrams of the heterojunctions.
A combined theoretical and experimental investigation on the transient photovoltage in organic photovoltaic cells
Authors: Yao Yao , Sun Xiaoyu , Ding Baofu , Li De-Li , Hou Xiaoyuan , Wu Chang-Qin
Published: May 2010

We present a time-dependent device model, describing the dynamical processes of both exciton induced by light illumination and charge carriers created from the exciton dissociation, to calculate the transient photovoltage (TPV) in single-layer organic photovoltaic cells. With reasonable parameters for the specific ITO (indium tin oxide)/CuPc (copper phthalocyanine)/Al (aluminum) structure, we could obtain the TPV well fitted with previous experimental observation by adjusting only the intensity of input laser pulse. Further, we saw a saturation of this TPV by changing the intensity of laser pulse from the calculation, which has been confirmed by the experimental measurement on ITO/NPB [N,N-bis(l-naphthyl)-N,N-diphenyl-1,l-biphentl-4,4-diamine]/Al structure. The saturated TPV value is found to be sensitive to the mobility of minority carriers, which might be useful in the estimation of mobilities.
Removal of near-interface traps at SiO2/4H–SiC (0001) interfaces by phosphorus incorporation
Authors: Okamoto Dai , Yano Hiroshi , Hatayama Tomoaki , Fuyuki Takashi
Published: May 2010

Effective removal of near-interface traps (NITs) in SiO2/4H–SiC (0001) structures through phosphorus incorporation is demonstrated in this paper. Low-temperature capacitance-voltage and thermal dielectric relaxation current measurements were employed to investigate NITs in oxides prepared by dry oxidation, NO annealing, and POCl3 annealing. Both the measurements revealed that the density of electrons trapped in NITs in POCl3-annealed oxide is smaller than that in dry and NO-annealed oxides. The drastic elimination of NITs lowers the interface state density and increases the channel mobility in 4H–SiC metal-oxide-semiconductor field-effect transistors.
Spectroscopy of neutral and charged exciton states in single CdSe/ZnS nanocrystals
Authors: Louyer Y. , Biadala L. , Tamarat Ph. , Lounis B.
Published: May 2010

We report a low temperature spectroscopic study of the lowest-energy exciton states in single CdSe/ZnS colloidal nanocrystals (NCs). In their neutral charge state, the zero-phonon lines of the lowest two levels of the band-edge exciton fine structure are directly observed in the photoluminescence (PL) spectrum. The attribution of these lines is confirmed by polarization-resolved studies of the PL spectrum and decay. We also identified the emission from charged NCs which displays a single zero-phonon line ∼17 meV redshifted with respect to the neutral NC emission lines. This bright trion state has a lifetime which ranges from 1.5 to 4.5 ns.
Conduction and transmission analysis in gold nanolayers embedded in zinc oxide for flexible electronics
Authors: Sivaramakrishnan K. , Alford T. L.
Published: May 2010

Gold-embedded zinc oxide structures are obtained in which the conduction mechanism changes from conduction through the oxide and activated tunneling between discontinuous metal islands to metallic conduction through a near-continuous layer, with increase in gold thickness. These structures can show resistivity as low as 5.2×10−5 Ω cm. Optical transmission is elucidated in terms of gold’s absorption due to interband electronic transitions, and free carrier absorption losses combined with limitation of the mean free path in discontinuous nanoparticles. The structures show transmittance, photopic averaged transmittance, and Haacke figure of merit values of 93%, 84%, and 15.1×10−3 Ω−1, respectively.
Doubly Pyridazine-bridged Dicobalt(II) and Dinickel(II) Side-by-side Complexes of Variously Substituted Conjugated Bis-bidentate Ligands
Authors: Price Jason R. , Lan Yanhua , Moubaraki Boujemaa , Murray Keith S. , Brooker Sally
Published: May 2010

A family of six acyclic bis-bidentate Schiff base ligands, Lx (prepared by condensation of 3,6-diformylpyridazine with a range of anilines: 2,4-dimethylaniline Lo,p-Me; 3,5-dichloroaniline Lm,m-Cl; 3,5-difluoroaniline Lm,m-F; p-toluidine Lp-Me; 4-aminophenol Lp-OH; 2,4,6-trimethylaniline Lo,o,p-Me), was complexed, 1:1, with cobalt(ii) or nickel(ii) perchlorate or tetrafluoroborate in refluxing dry acetonitrile. A family of dinuclear, doubly pyridazine-bridged complexes, M2II(Lx)2(solvent)n(ClO4)4 and [Ni2(Lo,o,p-Me)2(2H2O)4](BF4)4, resulted. An X-ray crystal structure determination on [Co2II(Lo,o,p)2(H2O)2(MeCN)2](ClO4)4·MeCN confirmed that it has the expected side-by-side architecture with axial solvent molecules completing the octahedral coordination sphere of the two cobalt(ii) ions. Magnetic analysis showed that the pyridazine bridges mediate weak-to-medium antiferromagnetic interactions between the metal ions. Specifically, for the cobalt(ii) complexes J was in the range –12 to –6 cm–1, while for the nickel(ii) complexes J was in the range –22 to –17 cm–1. There is no clear cut correlation of J values with electron-donating or -attracting properties of ligand substituent peripheral groups, although it is noted that the smallest J occurs in both the NiNi and CoCo families for the ligand Lo,o,p-Me.
A New Class of Hydroxy-Substituted Squaraine Rotaxane
Authors: Fu Na , Gassensmith Jeremiah J. , Smith Bradley D.
Published: May 2010

A templated macrocyclization reaction was used to permanently encapsulate a highly fluorescent hydroxy-substituted squaraine dye inside a tetralactam macrocycle. The free squaraine dye is quite rigid due to internal hydrogen bonding and its photophysical properties hardly change upon encapsulation. A combination of X-ray and NMR data show that the surrounding tetralactam macrocycle adopts an unusually rigid chair conformation and does not undergo rapid pirouetting. Because of its large size and conformational rigidity, the macrocycle creates anisotropic NMR shielding zones that extend over the N,N-dibutylamino groups at each end of the squaraine thread. This shielding anisotropy allows hindered aryl-N rotation to be observed by NMR spectroscopy and provides direct experimental evidence that quinoid-like resonance structures are major contributors to the bis(N,N-dialkylaminophenyl)squaraine resonance hybrid.
Synthesis and Phytotoxicity of Structural Analogues of Thaxtomin Natural Products
Authors: Molesworth Peter P. , Gardiner Michael G. , Jones Roderick C. , Smith Jason A. , Tegg Robert S. , Wilson Calum
Published: May 2010

Structural analogues of the phytotoxic thaxtomin natural products have been synthesized by building upon a piperazinedione core and from l-phenylalanine. The compounds were evaluated for their phytotoxic activity against Arabidopsis thaliana seedlings and some of the key features for activity have been identified.
Tuning Second-Order Non-linear (NLO) Optical Response of Organoimido-Substituted Hexamolybdates through Halogens: Quantum Design of Novel Organic-Inorganic Hybrid NLO Materials
Authors: Janjua Muhammad Ramzan Saeed Ashraf , Su Zhong-Min , Guan Wei , Liu Chun-Guang , Yan Li-Kai , Song Ping , Maheen Gull
Published: May 2010

The second-order non-linear optical (NLO) response of organoimido-substituted hexamolybdates has been tuned from 218.61 × 10–30 to 490.10 × 10–30 esu. The dipole polarizabilities and second-order nonlinear optical (NLO) properties of organoimido derivatives of hexamolybdates have been investigated by using the time-dependent density functional response theory (TDDFT). The electron withdrawing ability of F (fluorine) has played an important role in tuning the second-order NLO response in this class of organic-inorganic hybrid compounds; particularly system 6 [Mo6O18(NC16H8F2(CF3)2I)]2– with the static second-order polarizability (βvec
) computed to be 490.10 × 10–30 esu. Thus, our studied systems have the feasibility to be excellent tuneable second-order NLO materials. The analysis of the major contributions to the βvec
value suggests that the charge transfer (CT) from POM to organic ligand (D-A) along the z-axis has been enhanced with addition of F atoms at the end phenyl ring which directs head (POM) to tail (fluorinated ring) charge transfer. The computed βvec
values have been tuned by incorporation of different halogen atoms at the end phenyl ring of organoimido segment. Furthermore, substitution of two trifluoromethyl (–CF3) groups sideways along with iodine (I) at the terminus of end phenyl ring in the organoimido ligand has a striking influence on tuning the optical non-linearity, as CT from POM to the organoimido ligand was significantly increased. These systematic small changes in molecular composition by substitution of different halogen groups leads to a tuning the NLO response; the so-called ‘ripple effect’ catches this point nicely. Thus, the present investigation provides thought provoking insight into the tuneable NLO properties of organoimido-substituted hexamolybdates.
Network synchronization landscape reveals compensatory structures, quantization, and the positive effect of negative interactions
Authors: Nishikawa Takashi , Motter Adilson E.
Published: May 2010

Synchronization, in which individual dynamical units keep in pace with each other in a decentralized fashion, depends both on the dynamical units and on the properties of the interaction network. Yet, the role played by the network has resisted comprehensive characterization within the prevailing paradigm that interactions facilitating pairwise synchronization also facilitate collective synchronization. Here we challenge this paradigm and show that networks with best complete synchronization, least coupling cost, and maximum dynamical robustness, have arbitrary complexity but
quantized
total interaction strength, which constrains the allowed number of connections. It stems from this characterization that
negative
interactions as well as link
removals
can be used to systematically improve and optimize synchronization properties in both directed and undirected networks. These results extend the recently discovered compensatory perturbations in metabolic networks to the realm of oscillator networks and demonstrate why “less can be more” in network synchronization.
Exploiting the determinants of stochastic gene expression in
Saccharomyces cerevisiae
for genome-wide prediction of expression noise
Authors: Li Jingjing , Min Renqiang , Vizeacoumar Franco J. , Jin Ke , Xin Xiaofeng , Zhang Zhaolei
Published: May 2010

Gene regulation is a process with many steps allowing for stochastic biochemical reactions, which leads to expression noise—i.e., the cell-to-cell stochastic fluctuation in protein abundance. Such expression noise can give rise to drastically diverse phenotypes, even within isogenic cell populations. Although numerous biophysical approaches had been proposed to model the origin and propagation of expression noise in biological networks, these models essentially characterize the innate stochastic dynamics in gene regulation in a mechanistic way. In this work, by investigating expression noise in the context of yeast cellular networks, we place the biophysical formulism onto solid genetic ground. At the sequence level, we show that extremely noisy genes are highly conserved in their coding sequences. At the level of cellular networks where natural selection is manifested by the topological constraints, we show that genes with varying expression noise are modularly organized in the protein interaction network and are positioned orderly in the gene regulatory network. We demonstrate that these topological constraints are highly predictive of stochastic gene expression, with which we were able to confidently predict stochastic expression for more than 2,000 yeast genes whose expression noise was previously not known. We validated the predictions by high-content cell imaging. Our approach makes feasible genome-wide prediction of stochastic gene expression, and such predictability in turn suggests that expression noise is an evolvable genetic trait.
Strong synaptic transmission impact by copy number variations in schizophrenia
Authors: Glessner Joseph T. , Reilly Muredach P. , Kim Cecilia E. , Takahashi Nagahide , Albano Anthony , Hou Cuiping , Bradfield Jonathan P. , Zhang Haitao , Sleiman Patrick M. A. , Flory James H. , Imielinski Marcin , Frackelton Edward C. , Chiavacci Rosetta , Thomas Kelly A. , Garris Maria , Otieno Frederick G. , Davidson Michael , Weiser Mark , Reichenberg Abraham , Davis Kenneth L. , Friedman Joseph I. , Cappola Thomas P. , Margulies Kenneth B. , Rader Daniel J. , Grant Struan F. A. , Buxbaum Joseph D. , Gur Raquel E. , Hakonarson Hakon
Published: May 2010

Schizophrenia is a psychiatric disorder with onset in late adolescence and unclear etiology characterized by both positive and negative symptoms, as well as cognitive deficits. To identify copy number variations (CNVs) that increase the risk of schizophrenia, we performed a whole-genome CNV analysis on a cohort of 977 schizophrenia cases and 2,000 healthy adults of European ancestry who were genotyped with 1.7 million probes. Positive findings were evaluated in an independent cohort of 758 schizophrenia cases and 1,485 controls. The Gene Ontology synaptic transmission family of genes was notably enriched for CNVs in the cases (
P
= 1.5 × 10
−7
). Among these,
CACNA1B
and
DOC2A
, both calcium-signaling genes responsible for neuronal excitation, were deleted in 16 cases and duplicated in 10 cases, respectively. In addition,
RET
and
RIT2
, both ras-related genes important for neural crest development, were significantly affected by CNVs.
RET
deletion was exclusive to seven cases, and
RIT2
deletions were overrepresented common variant CNVs in the schizophrenia cases. Our results suggest that novel variations involving the processes of synaptic transmission contribute to the genetic susceptibility of schizophrenia.
Popular education and social change in Latin America
Authors: Jara Oscar H.
Published: May 2010

This article identifies the shortcomings of the dominant approach to education around the globe today, which does not lead to equitable development. Latin American thinkers point to an alternative perspective based on solidarity, inclusion and humanity. Such a perspective puts social change at the heart of education and is evident in what is known as Popular Education. Jara defines and analyses these complex terms, and provides an historical overview of the development of popular education in Latin America since 1960. He notes the key factors: popular education is ‘substantively political’, and it is underpinned by a liberating pedagogy which is possible in both formal as well as informal education, and which builds people's capacities to question their reality and existing ideologies, and to learn and unlearn continuously.
Scorpion in Combination with Gypsum: Novel Antidiabetic Activities in Streptozotocin‐Induced Diabetic Mice by Up‐Regulating Pancreatic PPARγ and PDX‐1 Expressions
Authors: Xie Weidong , Zhao Yunan , Gu Dayong , Du Lijun , Cai Guoping , Zhang Yaou
Published: May 2010

The management of diabetes without any side effects remains a challenge in medicine. In this study, antidiabetic activity and the mechanism of action of scorpion combined with gypsum (SG) were investigated. Streptozotocin‐induced diabetic mice were orally administrated with scorpion (200 mg kg−1 per day) in combination with gypsum (200 mg kg−1 per day) for 5 weeks. SG treatment resulted in decreased body weight, blood glucose and lipid levels, and increased serum and pancreatic insulin levels in diabetic mice. Furthermore, SG significantly increased the number and volume of beta cells in the Islets of Langerhans and promoted peroxisome proliferator‐activated receptor gamma and pancreatic duodenal homeobox 1 expressions in pancreatic tissues. However, scorpion or gypsum alone had no significant effect in this animal model. Metformin showed a slight or moderate effect in this diabetic model, but this effect was weak compared with that of SG. Taken together, SG showed a new antidiabetic effect in streptozotocin‐induced diabetic mice. This effect may possibly be involved in enhancing beta‐cell regeneration and promoting insulin secretion by targeting PPARγ and PDX‐1. Moreover, this new effect of SG offers a promising step toward the treatment of diabetic patients with beta‐cell failure as a complementary and alternative medicine.
Normal typicality and von Neumann’s quantum ergodic theorem
Authors: Goldstein Sheldon , Lebowitz Joel L. , Mastrodonato Christian , Tumulka Roderich , Zanghì Nino
Published: May 2010

We discuss the content and significance of John von Neumann’s quantum ergodic theorem (QET) of 1929, a strong result arising from the mere mathematical structure of quantum mechanics. The QET is a precise formulation of what we call normal typicality, i.e. the statement that, for typical large systems, every initial wave function
ψ
0
from an energy shell is ‘normal’: it evolves in such a way that |
ψ

t

〉〈
ψ

t

| is, for most
t
, macroscopically equivalent to the micro-canonical density matrix. The QET has been mostly forgotten after it was criticized as a dynamically vacuous statement in several papers in the 1950s. However, we point out that this criticism does not apply to the actual QET, a correct statement of which does not appear in these papers, but to a different (indeed weaker) statement. Furthermore, we formulate a stronger statement of normal typicality, based on the observation that the bound on the deviations from the average specified by von Neumann is unnecessarily coarse and a much tighter (and more relevant) bound actually follows from his proof.
The split ring resonator
Authors: Llewellyn Smith Stefan G. , Davis Anthony M. J.
Published: May 2010

We obtain band diagrams for a two-dimensional periodic structure consisting of an infinite square array of infinitely thin concentric circles (split rings) with narrow gaps. Our approach exploits the narrowness of the gaps and yields algebraic equations relating the frequency to the Bloch wavenumber and geometric properties of the array. Further asymptotic analysis indicates that the gravest mode has a frequency that scales in an inverse logarithmic fashion with the size of the gap and that exhibits anomalous dispersion. Near the origin of the Brillouin zone this ‘acoustic’ mode is dispersionless. Numerical solution of the eigenvalue problem in the single-gap case confirms these conclusions. The two lowest modes of the split ring can be interpreted as a splitting of the gravest propagating Rayleigh mode.
Expression of two Listeria monocytogenes antigens (P60 and LLO) in Lactococcus lactis and examination for use as live vaccine vectors
Authors: Bahey-El-Din Mohammed , Casey Pat G. , Griffin Brendan T. , Gahan Cormac G. M.
Published: May 2010

Listeria monocytogenesis a food-borne intracellular pathogen that mainly infects pregnant and immunocompromised individuals. The pore-forming haemolysin listeriolysin O (LLO), the main virulence factor ofListeria monocytogenes, allows bacteria to escape from the harsh environment of the phagosome to the cytoplasm of the infected cell. This leads to processing of bacterial antigens predominantly through the cytosolic MHC class I presentation pathway. We previously engineered the food-grade bacteriumLactococcus lactisto express LLO and demonstrated an LLO-specific CD8+response upon immunization of mice with the engineeredL. lactisvaccine strains. In the present work, we examined the immune response and protective efficacy of anL. lactisstrain co-expressing LLO and a truncated form of the listerial P60 antigen (tP60). Oral immunization revealed no significant protection against listeriosis withL. lactisexpressing LLO, tP60 or the combined LLO/tP60. In contrast, intraperitoneal vaccination induced an LLO-specific CD8+immune response with LLO-expressingL. lactisbut no significant improvement in protection was observed following vaccination with the combined LLO/tP60 expressingL. lactisstrain. This may be due to the low level of tP60 expression in the LLO/tP60 strain. These results demonstrate the necessity for improved oral vaccination strategies using LLO-expressingL. lactisvaccine vectors.
Difficulties in using 1,3-β-d-glucan as the screening test for the early diagnosis of invasive fungal infections in patients with haematological malignancies – high frequency of false-positive results and their analysis
Authors: Racil Zdenek , Kocmanova Iva , Lengerova Martina , Weinbergerova Barbora , Buresova Lucie , Toskova Martina , Winterova Jana , Timilsina Shira , Rodriguez Isa , Mayer Jiri
Published: May 2010

We have evaluated the contribution of the 1,3-β-d-glucan (BG) assay for the screening of invasive fungal infections (IFIs) in patients with haematological malignancies. Serum samples from patients at risk of IFI were collected twice a week and retrospectively tested using the BG assay. BG screening was performed on 1143 samples from 91 patients during 104 anticancer treatment cycles. Proven and probable cases of IFI occurred in 9 (8.7 %) treatment cycles. Depending on the criterion of positivity used (1× >60 pg ml−1, 1× >80 pg ml−1, 2× >60 pg ml−1 or 2× >80 pg ml−1) the sensitivity and specificity were 89, 89, 67 and 44 %, and 20, 48, 33 and 56 %, respectively. Although the test was marked as positive in 82, 68, 54 and 45 % of all the treatment cycles, in the majority of cases, these positivities were probably false. The major limit of the BG test was an extremely low positive predictive value (10 to 12 %). We have analysed mucositis, candida colonization, bacteraemia, use of antimicrobials, erythrocyte and thrombocyte filtered blood products, collecting tubes or sampling via venous catheters. Even though no factor is a major source of BG, it could at least partially influence BG assay performance. Thus, BG detection has a limited usefulness as a screening method for IFIs in patients with haematological malignancies.
Pulmonary tuberculosis due to Mycobacterium microti: a study of six recent cases in France
Authors: Panteix G. , Gutierrez M. C. , Boschiroli M. L. , Rouviere M. , Plaidy A. , Pressac D. , Porcheret H. , Chyderiotis G. , Ponsada M. , Van Oortegem K. , Salloum S. , Cabuzel S. , Bañuls A. L. , Van de Perre P. , Godreuil S.
Published: May 2010

Human tuberculosis caused by Mycobacterium microti is rare, but its prevalence and clinical significance may have been underestimated. To the best of our knowledge, 21 cases have been reported in the literature in the last decade. We report six recent pulmonary cases caused by M. microti over a period of 5 years detected in French clinical mycobacteriology laboratories of the hospital network. Our data confirm the potential of M. microti to cause clinical illness in immunocompetent patients. M. microti grew slowly from specimens, delaying the final microbiological diagnosis. Therefore, patients with tuberculosis caused by M. microti could benefit from the use of rapid diagnostic molecular techniques directly on clinical samples. From a review of the literature and this study, a classical antituberculous therapy seems effective in treating patients with M. microti disease.
Stenotrophomonas maltophilia flagellin induces a compartmentalized innate immune response in mouse lung
Authors: Zgair Ayaid Khadem , Chhibber Sanjay
Published: May 2010

Intranasal (i.n.) instillation of different amounts of purifiedStenotrophomonas maltophiliaflagellin preparation (1, 5 and 15 μg) in BALB/c mice stimulated a transient innate immune response in the lungs. This was characterized by infiltration of different kinds of leukocytes (neutrophils, monocytes and lymphocytes), production of various inflammatory mediators (tumour necrosis factor alpha, interleukin 1 beta, interleukin 10, nitric oxide, myeloperoxidase and malondialdehyde) and activated alveolar macrophages (AMs). The proinflammatory cytokine production resulted in accumulation of activated neutrophils and macrophages and their products following immunostimulation with flagellin. The activation of AMs by flagellin was non-specific as AMs obtained from flagellin-treated animals, even after 4 h of exposure, were found to engulf and killS. maltophiliaandStaphylococcus aureusefficiently compared to macrophages obtained from control animals. i.n. instillation of 5 μg flagellin resulted in the generation of an effective innate immunity compared to other flagellin doses. Our data provide strong evidence thatS. maltophiliaflagellin stimulates innate immunity in mouse lung.
Chromatin and sequence features that define the fine and gross structure of genomic methylation patterns
Authors: Edwards John R. , O'Donnell Anne H. , Rollins Robert A. , Peckham Heather E. , Lee Clarence , Milekic Maria H. , Chanrion Benjamin , Fu Yutao , Su Tao , Hibshoosh Hanina , Gingrich Jay A. , Haghighi Fatemeh , Nutter Robert , Bestor Timothy H.
Published: May 2010

Abnormalities of genomic methylation patterns are lethal or cause disease, but the cues that normally designate CpG dinucleotides for methylation are poorly understood. We have developed a new method of methylation profiling that has single-CpG resolution and can address the methylation status of repeated sequences. We have used this method to determine the methylation status of >275 million CpG sites in human and mouse DNA from breast and brain tissues. Methylation density at most sequences was found to increase linearly with CpG density and to fall sharply at very high CpG densities, but transposons remained densely methylated even at higher CpG densities. The presence of histone H2A.Z and histone H3 di- or trimethylated at lysine 4 correlated strongly with unmethylated DNA and occurred primarily at promoter regions. We conclude that methylation is the default state of most CpG dinucleotides in the mammalian genome and that a combination of local dinucleotide frequencies, the interaction of repeated sequences, and the presence or absence of histone variants or modifications shields a population of CpG sites (most of which are in and around promoters) from DNA methyltransferases that lack intrinsic sequence specificity.
High-throughput sequencing reveals extensive variation in human-specific L1 content in individual human genomes
Authors: Ewing Adam D. , Kazazian Haig H.
Published: May 2010

Using high-throughput sequencing, we devised a technique to determine the insertion sites of virtually all members of the human-specific L1 retrotransposon family in any human genome. Using diagnostic nucleotides, we were able to locate the approximately 800 L1Hs copies corresponding specifically to the pre-Ta, Ta-0, and Ta-1 L1Hs subfamilies, with over 90% of sequenced reads corresponding to human-specific elements. We find that any two individual genomes differ at an average of 285 sites with respect to L1 insertion presence or absence. In total, we assayed 25 individuals, 15 of which are unrelated, at 1139 sites, including 772 shared with the reference genome and 367 nonreference L1 insertions. We show that L1Hs profiles recapitulate genetic ancestry, and determine the chromosomal distribution of these elements. Using these data, we estimate that the rate of L1 retrotransposition in humans is between 1/95 and 1/270 births, and the number of dimorphic L1 elements in the human population with gene frequencies greater than 0.05 is between 3000 and 10,000.
Disruption ofptLPD1orptLPD2, Genes That Encode Isoforms of the Plastidial Lipoamide Dehydrogenase, Confers Arsenate Hypersensitivity in Arabidopsis
Authors: Chen Weihua , Chi Yingjun , Taylor Nicolas L. , Lambers Hans , Finnegan Patrick M.
Published: May 2010

Arsenic is a ubiquitous environmental poison that inhibits root elongation and seed germination to a variable extent depending on the plant species. To understand the molecular mechanisms of arsenic resistance, a genetic screen was developed to isolate arsenate overly sensitive (aos) mutants from an activation-tagged Arabidopsis (Arabidopsis thaliana) population. Three aos mutants were isolated, and the phenotype of each was demonstrated to be due to an identical disruption of plastidial LIPOAMIDE DEHYDROGENASE1 (ptLPD1), a gene that encodes one of the two E3 isoforms found in the plastidial pyruvate dehydrogenase complex. In the presence of arsenate, ptlpd1-1 plants exhibited reduced root and shoot growth and enhanced anthocyanin accumulation compared with wild-type plants. The ptlpd1-1 plants accumulated the same amount of arsenic as wild-type plants, indicating that the aos phenotype was not due to increased arsenate in the tissues but to an increase in the innate sensitivity to the poison. Interestingly, a ptlpd1-4 knockdown allele produced a partial aos phenotype. Two loss-of-function alleles of ptLPD2 in Arabidopsis also caused elevated arsenate sensitivity, but the sensitivity was less pronounced than for the ptlpd1 mutants. Moreover, both the ptlpd1 and ptlpd2 mutants were more sensitive to arsenite than wild-type plants, and the LPD activity in isolated chloroplasts from wild-type plants was sensitive to arsenite but not arsenate. These findings show that the ptLPD isoforms are critical in vivo determinants of arsenite-mediated arsenic sensitivity in Arabidopsis and possible strategic targets for increasing arsenic tolerance.
The Maize Mixed-Linkage (1→3),(1→4)-β-d-Glucan Polysaccharide Is Synthesized at the Golgi Membrane
Authors: Carpita Nicholas C. , McCann Maureen C.
Published: May 2010

With the exception of cellulose and callose, the cell wall polysaccharides are synthesized in Golgi membranes, packaged into vesicles, and exported to the plasma membrane where they are integrated into the microfibrillar structure. Consistent with this paradigm, several published reports have shown that the maize (Zea mays) mixed-linkage (1→3),(1→4)-β-d-glucan, a polysaccharide that among angiosperms is unique to the grasses and related Poales species, is synthesized in vitro with isolated maize coleoptile Golgi membranes and the nucleotide-sugar substrate, UDP-glucose. However, a recent study reported the inability to detect the β-glucan immunocytochemically at the Golgi, resulting in a hypothesis that the mixed-linkage β-glucan oligomers may be initiated at the Golgi but are polymerized at the plasma membrane surface. Here, we demonstrate that (1→3),(1→4)-β-d-glucans are detected immunocytochemically at the Golgi of the developing maize coleoptiles. Further, when maize seedlings at the third-leaf stage were pulse labeled with [14C]O2 and Golgi membranes were isolated from elongating cells at the base of the developing leaves, (1→3),(1→4)-β-d-glucans of an average molecular mass of 250 kD and higher were detected in isolated Golgi membranes. When the pulse was followed by a chase period, the labeled polysaccharides of the Golgi membrane diminished with subsequent transfer to the cell wall. (1→3),(1→4)-β-d-Glucans of at least 250 kD were isolated from cell walls, but much larger aggregates were also detected, indicating a potential for intermolecular interactions with glucuronoarabinoxylans or intermolecular grafting in muro.
Bs1, a New Chimeric Gene Formed by Retrotransposon-Mediated Exon Shuffling in Maize
Authors: Elrouby Nabil , Bureau Thomas E.
Published: May 2010

Transposons are major components of all eukaryotic genomes. Although traditionally regarded as causes of detrimental mutations, recent evidence suggests that transposons may play a role in host gene diversification and evolution. For example, host gene transduction by retroelements has been suggested to be both common and to have the potential to create new chimeric genes by the shuffling of existing sequences. We have previously shown that the maize (Zea mays subsp. mays) retrotransposon Bs1 has transduced sequences from three different host genes. Here, we provide evidence that these transduction events led to the generation of a chimeric new gene that is both transcribed and translated. Expression of Bs1 is tightly controlled and occurs during a narrow developmental window in early ear development. Although all Bs1-associated transduction events took place before Zea speciation, a full uninterrupted open reading frame encoding the BS1 protein may have arisen in domesticated maize or in the diverse populations of its progenitor Z. mays subsp. parviglumis. We discuss potential functions based on domain conservation and evidence for functional constraints between the transduced sequences and their host gene counterparts.
Structural stability and optical properties of nanocrystalline zirconia
Authors: Manna Sujit , Ghoshal Tandra , Deb A. K. , De S. K.
Published: May 2010

Nanoparticles of the cubic phase of zirconia (ZrO2) of size range 4.5–8.7 nm have been synthesized by alkaline hydrolysis of a zirconium salt followed by solvothermal reaction. Subsequently, the room-temperature stability of cubic ZrO2nanoparticles has been explored with the goal of understanding how crystal structure tends to transform into a structure of higher symmetry with decreasing crystallite size. The room-temperature-stable cubic phase in nanosized ZrO2has been observed to transform into the monoclinic phase at 873 K. The crystalline phases of ZrO2nanocrystals have been determined quantitatively by Rietveld refinement. Lattice constant and internal strain increase with decreasing particle size. Growth kinetics studies have established that cubic nanocrystals are more stable at smaller crystallite sizes. UV–visible absorption spectra show an absorption peak at 275 nm which indicates a lowering of the band gap energy. Photoluminescence spectra of zirconia nanoparticles show an emission peak at 305 nm at room temperature. The modification of the optical properties is explained on the basis of oxygen vacancies present within the samples.
phenix.model_vs_data: a high-level tool for the calculation of crystallographic model and data statistics
Authors: Afonine Pavel V. , Grosse-Kunstleve Ralf W. , Chen Vincent B. , Headd Jeffrey J. , Moriarty Nigel W. , Richardson Jane S. , Richardson David C. , Urzhumtsev Alexandre , Zwart Peter H. , Adams Paul D.
Published: May 2010

phenix.model_vs_datais a high-level command-line tool for the computation of crystallographic model and data statistics, and the evaluation of the fit of the model to data. Analysis of all Protein Data Bank structures that have experimental data available shows that in most cases the reported statistics, in particularRfactors, can be reproduced within a few percentage points. However, there are a number of outliers where the recomputedRvalues are significantly different from those originally reported. The reasons for these discrepancies are discussed.
Linking habitat characteristics with juvenile density to quantify Salmo salar and Salmo trutta smolt production in the river Sävarån, Sweden
Authors: MOLIN J. , KAGERVALL A. , RIVINOJA P. K.
Published: May 2010

Abstract  Habitat mapping along 85 km of river was related to juvenile (15 years of electric fishing) and smolt (3 years of screw‐trapping) abundance data to estimate salmon, Salmo salar L., and sea trout, Salmo trutta L., smolt production in the River Sävarån, northern Sweden. Spawning site selection by radio‐tagged salmon (n = 12) and sea trout (n = 4) was also assessed. Fifty‐one hectares of potential spawning and nursery habitat was found in the main stem river, representing 25% of the total river area. These areas were estimated to yield 1300–7580 salmon and 630–3540 sea trout smolts based on juvenile densities, equating with 3 years of screw‐trap data (2990–5080 salmon and 680–2520 trout smolts, respectively). A hypothetical maximum production of about 19 900 salmon smolts was predicted for the river at a density of 40, 0+ salmon 100 m−2. Tracking adults during the spawning period identified optimal and potential reproductive areas.
Turbidity Hampers Mate Choice in a Pipefish
Authors: Sundin Josefin , Berglund Anders , Rosenqvist Gunilla
Published: May 2010

European coastal waters have in recent years become more turbid as algal growth has increased, probably due to eutrophication, global warming and changes in fish communities. Turbidity reduces visibility, and such changes may in turn affect animal behaviour as well as evolutionary processes that are dependent on visual stimuli. In this study we experimentally manipulated water visibility and olfactory cues to investigate mate choice using the sex role‐reversed broad‐nosed pipefish Syngnathus typhle as our study organism. We show that males spent significantly longer time assessing females when they had access to full visual cues, compared to when visibility was reduced. Presence or absence of olfactory cues from females did not affect mate choice, suggesting that the possible use of smell could not make up for a reduction in visibility. This implies that mate choice is environmentally dependent and that an increased turbidity may affect processes of sexual selection through an impaired possibility for visually based mate choice.
Effect of thick DLC coating on fatigue behaviour of magnesium alloy in laboratory air and demineralised water
Authors: UEMATSU Y. , TOKAJI K. , TAKEKAWA H.
Published: May 2010

Rotating bending fatigue tests have been performed using Diamond‐like carbon (DLC) coated specimens of a wrought magnesium alloy, AZ80A, in laboratory air and demineralised water and the effect of DLC coating on fatigue and corrosion fatigue behaviour was studied. Three film thicknesses of 3.5 μm, 13 μm, and 25 μm (two‐layer film) were evaluated and particular attention was paid to the role of thick DLC coating. In laboratory air, the fatigue strengths of the DLC‐coated specimens were higher than that of the substrate specimen and increased with increasing film thickness. This was because hard DLC coating with good adhesion suppressed the crack initiation due to cracking of inclusions or cyclic slip deformation on the substrate surface. In demineralised water, the fatigue strength of the 3.5‐μm DLC‐coated specimen was the same as that of the substrate specimen due to the penetration of the water through pre‐existing film defects, while the 13‐μm and 25‐μm DLC‐coated specimens showed increased corrosion fatigue strength with increasing film thickness and also exhibited nearly the same fatigue strength as in laboratory air except for a few premature failed specimens, indicating a potential of thick DLC coating or two‐layer coating for complete improvement of corrosion fatigue strength in aqueous environments.
Deficiency in the amino aldehyde dehydrogenase encoded by GmAMADH2, the homologue of rice Os2AP, enhances 2‐acetyl‐1‐pyrroline biosynthesis in soybeans (Glycine max L.)
Authors: Arikit Siwaret , Yoshihashi Tadashi , Wanchana Samart , Uyen Tran T. , Huong Nguyen T. T. , Wongpornchai Sugunya , Vanavichit Apichart
Published: May 2010

2‐Acetyl‐1‐pyrroline (2AP), the volatile compound that provides the ‘popcorn‐like’ aroma in a large variety of cereal and food products, is widely found in nature. Deficiency in amino aldehyde dehydrogenase (AMADH) was previously shown to be the likely cause of 2AP biosynthesis in rice (Oryza sativa L.). In this study, the validity of this mechanism was investigated in soybeans (Glycine max L.). An assay of AMADH activity in soybeans revealed that the aromatic soybean, which contains 2AP, also lacked AMADH enzyme activity. Two genes, GmAMADH1 and GmAMADH2, which are homologous to the rice Os2AP gene that encodes AMADH, were characterized. The transcription level of GmAMADH2 was lower in aromatic varieties than in nonaromatic varieties, whereas the expression of GmAMADH1 did not differ. A double nucleotide (TT) deletion was found in exon 10 of GmAMADH2 in all aromatic varieties. This variation caused a frame‐shift mutation and a premature stop codon. Suppression of GmAMADH2 by introduction of a GmAMADH2‐RNAi construct into the calli of the two nonaromatic wild‐type varieties inhibited the synthesis of AMADH and induced the biosynthesis of 2AP. These results suggest that deficiency in the GmAMADH2 product, AMADH, plays a similar role in soybean as in rice, which is to promote 2AP biosynthesis. This phenomenon might be a conserved mechanism among plant species.
Body weight and beauty: the changing face of the ideal female body weight
Authors: Bonafini B. A. , Pozzilli P.
Published: May 2010

By observing the art of different eras, as well as the more recent existence of the media, it is obvious that there have been dramatic changes in what is considered a beautiful body. The ideal of female beauty has shifted from a symbol of fertility to one of mathematically calculated proportions. It has taken the form of an image responding to men's sexual desires. Nowadays there seems to be a tendency towards the destruction of the feminine, as androgynous fashion and appearance dominate our culture. The metamorphosis of the ideal woman follows the shifting role of women in society from mother and mistress to a career‐orientated individual. Her depiction by artists across the centuries reveals this change in role and appearance that should be interpreted within the social and historical context of each era with its own theories of what constituted the ideal female body weight.
Does Tort Law Reform Help or Hurt Consumers?*
Authors: KING STEPHEN P.
Published: May 2010

Legal limits on insurance damage claims have been introduced in Australia, the United States and other jurisdictions. In this article, I construct a simple competitive model to analyse the effect of tort law reforms on consumers. The model shows that reforms to limit non‐economic losses make consumers unambiguously worse off ex ante. Although insurance premiums fall and these reductions are passed on to consumers in full, this gain is more than offset by the increased risk that consumers are forced to bear. In contrast, reforms for income‐related (i.e. economic) losses lead to ambiguous outcomes. The potential benefits from limits to economic loss arise due to the inability of insurers to price discriminate on the basis of income or expected loss. Because of this, there is an implicit cross subsidy from low‐ to high‐income consumers that is embedded in the insurance premium and relevant product price. Tort law reforms partially unwind this cross subsidy. The results presented in this article show that tort law reforms may achieve their stated goal, such as lowering monetary prices, but can still make consumers worse off by introducing an uninsurable risk. There is also an important difference between reforms that limit claims for economic and non‐economic losses. Insurance for economic loss will generally include an implicit cross subsidy and, as a consequence, reforms can alter the ex ante utility for different groups of consumers in different ways.