bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-driven soft imaging in liquid by means of photothermal excitation
Authors: Paoletti P. , Basso M. , Pini V. , Tiribilli B. , Vassalli M.
Published: December 2011

The use of a laser to induce oscillations of an atomic force microscopy cantilever provides a way to excite the dynamics of the system in a very controlled manner. This excitation scheme has been used to obtain reliable self-sustained oscillations, in air and in liquid environments, and to implement an additional control loop leading to a soft, low-interaction, working mode. The dynamics of the oscillating cantilever has been characterized, both theoretically and experimentally, and the effectiveness of the approach has been verified on a test sample.
Controlled spontaneous emission in plasmonic whispering gallery antennas
Authors: Vesseur Ernst Jan R. , Polman Albert
Published: December 2011

We present a plasmonic whispering gallery nanoantenna doped with an ATTO680 dye that shows cavity-modified spontaneous emission. The plasmonic ring antenna consists of a circular groove cavity in a single-crystal Au surface that sustains resonances with different azimuthal and radial mode order. We observe spectral reshaping of the dye emission that can be tuned over a broad band by varying the cavity resonance conditions.
The dynamical process of the phase transition from VO2(M) to VO2(R)
Authors: Qu B. Y. , He H. Y. , Pan B. C.
Published: December 2011

The dynamical process of the metal-insulator transition, from VO2(M) to VO2(R), is studied in the framework of the dynamics theory. It is found that the thermal exciting of the Raman-active Ag mode with frequency of 212.7 cm-1 in the VO2(M) lattice drives the compound to be the VO2(R) lattice. The intermediate structures during the phase transition are revealed, from which we find that when the distortion of the atomic network away from its initial network in the M phase exceeds 60%, the system becomes metallic. At the moment, the monoclinic symmetry of the crystal remains still, but more V ions are dimerized. This strongly suggests that the dimerization of the V ions in the compound plays a critical role in the transition from the M phase to the R phase.
Effects of matching conditions in effective-mass theory: Quantum wells, transmission, and metal-induced gap states
Authors: Harrison Walter A.
Published: December 2011

Kroemer and Zhu have shown that the traditional matching of wavefunctions between regions of different effective mass (matching ψ and (1/m*)∂ψ/∂x) is not correct, but that one should match (1/√m*)ψ and (1/√m*)∂ψ/∂x. It has not been clear how serious the error is in using the traditional formula. We apply the two sets of conditions to the calculation of quantum-well states, to the transmission of an interface, and to the formation of metal-induced gap states (MIGS). We find that the predicted effects due to mass difference by the traditional formula are not even qualitatively correct in the first two cases and very much underestimated for the shifts in Schottky-barrier height due to MIGS. The MIGS shifts however always remain very small.
A polarization independent liquid crystal phase modulation adopting surface pinning effect of polymer dispersed liquid crystals
Authors: Lin Yi-Hsin , Tsou Yu-Shih
Published: December 2011

A polarization-independent liquid crystal (LC) phase modulation using the surface pinning effect of polymer dispersed liquid crystals (SP-PDLC) is demonstrated. In the bulk region of the SP-PDLC, the orientations of LC directors are randomly dispersed; thus, any polarization of incident light experiences the same averaged refractive index. In the regions near glass substrates, the LC droplets are pinned. The orientations of top and bottom droplets are orthogonal. Two eigen-polarizations of an incident light experience the same phase shift. As a result, the SP-PDLC is polarization independent. Polarizer-free microlens arrays of SP-PDLC are also demonstrated. The SP-PDLC has potential for application in spatial light modulators, laser beam steering, and electrically tunable microprisms.
Unintentional doping induced splitting of G peak in bilayer graphene
Authors: Lin S. S. , Chen B. G. , Pan C. T. , Hu S. , Tian P. , Tong L. M.
Published: December 2011

Raman characterizations show the G peak of an unintentional doped single crystal bilayer graphene (BLG) splits into two peaks: S and AS peaks. From the relative shift between S and AS peaks, the doping concentration is estimated to be from 8.8 × 1012 cm−2 to 2 × 1013 cm−2, as in the same order of that in monolayer graphene prepared under the same condition. The dopants distribute relatively homogeneously in a 0.7 mm× 0.3 mm large BLG judged through the G peak splitting. The 2D peak of heavy doped BLG can only be deconvoluted into three peaks, corresponding to 2D1B, 2D1A, and 2D2A peaks.
Two-dimensional plasmonic nanosurface for photovoltaics
Authors: Polemi Alessia , Shuford Kevin L.
Published: December 2011

In this paper, we investigate a two-dimensional corrugated plasmonic nanosurface for efficient light trapping in a photovoltaic cell. Inspired by a well-known one-dimensional grating nanosurface, the present configuration is composed of two perpendicular gratings in the metal film that intersect to yield cross-shaped nanoelements. The surface corrugation is then covered by a silicon film. An additional degree of freedom can be introduced into the design by interrupting the grid in both directions. We show that this extra spacing between the array elements can be used to tune the absorption properties of the nanosurface. By including the effect of the solar spectrum, we demonstrate how this two-dimensional configuration is more efficient than its one-dimensional counterpart in terms of the actual short circuit photocurrent density. Finally, we propose possible extensions of this structure design, which can further enhance the solar cell performance.
Sensitivity field for nonautonomous molecular rotors
Authors: Akimov A. V. , Sinitsyn N. A.
Published: December 2011

We propose a numerical approach to quantify the control of a nonautonomous molecular rotor motion. Unlike straightforward molecular dynamics simulations in an explicitly time-dependent framework, our method is based on the theory of geometric phases. This theory allows us to define a sensitivity field (SF) in control parameter space that characterizes average motion of a molecule induced by a cyclic perturbation. We show that the SF can be obtained using only equilibrium free energy sampling techniques. A density plot of the SF quantifies response of a molecule to an arbitrary cyclic adiabatic evolution of parameters. For demonstration, we numerically find the SFs for two surface mounted molecular rotor molecules that can be driven, in practice, by strong time-dependent electric fields of a STM tip.
Characterization of damage-induced magnetization for 304 austenitic stainless steel
Authors: Li Hongmei , Chen Zhenmao , Li Yong
Published: December 2011

Experimental and analytical studies are carried out on features of damages-induced magnetization (natural magnetization) of the 304 austenitic stainless steel. Various tensile plastic deformations are introduced into test pieces with different initial discontinuities. The surface strain distributions and natural magnetic fields are measured during and after the tensile testings. The magnetization distributions inside the material are reconstructed from the measured natural magnetic field signals through inverse analysis. From the experimental and numerical results, it is clarified that at first, the magnetization direction of the material depends on the load direction and damage distribution and the distribution pattern of magnetization reflects the existence of concentrative damages. Second, the relationship between the intensity of damage-induced magnetization and the maximum plastic strain follows a simple formula proposed in this paper. Third, the magnetization intensity is correlated with the volume fraction of the martensitic phase. Finally, the theory of minimum energy is applicable to qualitatively explain the mechanism of the damage-induced magnetization for the 304 austenitic stainless steel.
Spin injection from two-dimensional electron and hole gases in resonant tunneling diodes
Authors: Galvão Gobato Y. , Galeti H. V. A. , dos Santos L. F. , López-Richard V. , Cesar D. F. , Marques G. E. , Brasil M. J. S. P. , Orlita M. , Kunc J. , Maude D. K. , Henini M. , Airey R. J.
Published: December 2011

We have investigated the polarized-resolved photoluminescence from the contact layers and the quantum-well in an n-type GaAs/GaAlAs resonant tunneling diode for magnetic fields up to 19 T. The optical emission from the GaAs contact layers comprises the recombination from highly spin-polarized two-dimensional electron and hole gases with free tunneling carriers. Both the energy position and intensity of this indirect recombination are voltage-dependent and show remarkably abrupt variations near scattering-assisted tunneling resonances. Our results show that these two dimensional gases act as spin-polarized sources for carriers tunneling through the well in resonant tunneling diodes.
Anomalous optical switching and thermal hysteresis behaviors of VO2 films on glass substrate
Authors: Li Jian , Dho Joonghoe
Published: December 2011

In order to study the optical switching of vanadium dioxide (VO2) and its thermal hysteresis behavior, we fabricated VO2 films on glass substrates at various oxygen pressures. Only the VO2 films made at 5–10 mTorr displayed x-ray diffraction peaks and metal-insulator transition. Upon heating and cooling, remarkably, these samples exhibited significant optical switching behaviors with a clockwise thermal hysteresis in the infrared range of >850 nm or with a counterclockwise thermal hysteresis in the near visible range of 650–850 nm. The temperature dependence of optical absorption was explained by the O2p-V3d splitting depending on the structural transition of VO2.
Effects of thermal gradients on the intensity of vortices generated in a cylindrical annulus
Authors: Navarro M. C. , Herrero H.
Published: December 2011

This paper shows the influence of horizontal and vertical temperature gradients on the intensity of vertical vortices, qualitatively similar to dust devils, generated by a convective instability in a cylindrical annulus non-homogeneously heated. The behavior of the vortices formed is studied, showing that the increase of the temperature gradients intensifies the strength of the vortical structures developed and vice versa, small horizontal and vertical temperature gradients lead to weaker vortices or even make them disappear. Consequently, the intensity of the vortices can be controlled thermally by cooling or heating adequately the bottom boundary.
Low-field mobility in ultrathin silicon nanowire junctionless transistors
Authors: Sorée Bart , Magnus Wim , Vandenberghe William
Published: December 2011

We theoretically investigate the phonon, surface roughness and ionized impurity limited low-field mobility of ultrathin silicon n-type nanowire junctionless transistors in the long channel approximation with wire radii ranging from 2 to 5 nm, as function of gate voltage. We show that surface roughness scattering is negligible as long as the wire radius is not too small and ionized impurity scattering is the dominant scattering mechanism. We also show that there exists an optimal radius where the ionized impurity limited mobility exhibits a maximum.
Contact effects in high performance fully printed p-channel organic thin film transistors
Authors: Valletta A. , Daami A. , Benwadih M. , Coppard R. , Fortunato G. , Rapisarda M. , Torricelli F. , Mariucci L.
Published: December 2011

Contact effects have been investigated in fully printed p-channel organic thin film transistors with field effect mobility up to 2 cm2/Vs. Electrical characteristics of the organic thin film transistors, with channel length <200 μm, are seriously influenced by contact effects with an anomalous increase of the contact resistance for increasing source-drain voltage. Assuming that contact effects are negligible in long channel transistors and using gradual channel approximation, we evaluated the current-voltage characteristics of the injection contact, showing that I-V characteristics can be modeled as a reverse biased Schottky diode, including barrier lowering induced by the Schottky effect.
A small dasyurid predator (Sminthopsis virginiae) rapidly learns to avoid a toxic invader
Authors: Webb Jonathan K. , Pearson David , Shine Richard
Published: December 2011

Context Invasive species are a leading cause of extinctions, yet predicting their ecological impacts poses a formidable challenge for conservation biologists. When native predators are naïve to invaders, they may lack appropriate behaviours to deal with the invader. In northern Australia, the invasion of the highly toxic cane toad (Rhinella marina) has caused serious population declines of reptilian and mammalian predators that are ill equipped to deal with toad toxins. Cane toads recently invaded the Kimberley region of Western Australia, where they potentially threaten several species of small dasyurid predators. Aims We investigated whether red-cheeked dunnarts (Sminthopsis virginiae) attack cane toads, and if so, whether individuals subsequently learn to avoid toads as prey. Methods We quantified feeding and learning behaviours in toad-naïve red-cheeked dunnarts from the north Kimberley in Western Australia. Key results All toad-naïve dunnarts attacked toads during their first encounter. Most dunnarts bit the toad on the snout, killed it by biting the cranium, and consumed the toad snout-first, thereby initially avoiding the toad’s parotoid glands. Most dunnarts partially consumed toads before discarding them, and only one animal showed visible signs of toad poisoning. All dunnarts rapidly learnt to avoid toads as prey after one or two encounters. Predators rejected toads as prey for the duration of the study (22 days), suggesting long-term retention of the knowledge that toads are noxious. Conclusions Our results show that red-cheeked dunnarts rapidly learn to avoid cane toads as prey. Implications Our study was limited by small sample sizes, but our results suggest that small dasyurids can adapt to the cane toad invasion via taste aversion learning.
Estimating and indexing feral cat population abundances using camera traps
Authors: Bengsen Andrew , Butler John , Masters Pip
Published: December 2011

Context The ability to monitor changes in population abundance is critical to the success of pest animal management and research programs. Feral cats (Felis catus) are an important pest animal, but current monitoring techniques have limited sensitivity or are limited in use to particular circumstances or habitats. Recent advances in camera-trapping methods provide the potential to identify individual feral cats, and to use this information to estimate population abundances using capture–mark–recapture (CMR) methods. Aims Here, we use a manipulative study to test whether camera-trapping and CMR methods can be used to estimate feral cat abundances. Methods We established a grid of infrared cameras and lure stations over three pastoral properties on Kangaroo Island, Australia, for 15 days. We then reduced the population abundance with an intensive trapping program and repeated the camera survey. We estimated population abundances using robust design CMR models, and converted abundance estimates to densities using home-range data from GPS tracking. We also calculated relative abundance indices from the same data. Key results The CMR methods produced credible estimates of the change in population abundance, with useful confidence intervals, showing a statistically identifiable population decline from at least 0.7 cats km–2 before trapping down to 0.4 cats km–2 after trapping. The indexing method also showed a statistically identifiable decrease in abundance. Conclusions Camera-trapping and CMR methods can provide a useful method for monitoring changes in the absolute abundance of feral cat populations. Camera-trap data may also be used to produce indices of relative abundance when the assumptions of CMR models cannot be met. Implications These methods are widely applicable. The ability to reliably estimate feral cat abundances allows for more effective management than is generally available.
Niche specialization of terrestrial archaeal ammonia oxidizers
Authors: Gubry-Rangin Cécile , Hai Brigitte , Quince Christopher , Engel Marion , Thomson Bruce C. , James Phillip , Schloter Michael , Griffiths Robert I. , Prosser James I. , Nicol Graeme W.
Published: December 2011

Soil pH is a major determinant of microbial ecosystem processes and potentially a major driver of evolution, adaptation, and diversity of ammonia oxidizers, which control soil nitrification. Archaea are major components of soil microbial communities and contribute significantly to ammonia oxidation in some soils. To determine whether pH drives evolutionary adaptation and community structure of soil archaeal ammonia oxidizers, sequences of
amoA
, a key functional gene of ammonia oxidation, were examined in soils at global, regional, and local scales. Globally distributed database sequences clustered into 18 well-supported phylogenetic lineages that dominated specific soil pH ranges classified as acidic (pH <5), acido-neutral (5≤ pH <7), or alkalinophilic (pH ≥7). To determine whether patterns were reproduced at regional and local scales,
amoA
gene fragments were amplified from DNA extracted from 47 soils in the United Kingdom (pH 3.5–8.7), including a pH-gradient formed by seven soils at a single site (pH 4.5–7.5). High-throughput sequencing and analysis of
amoA
gene fragments identified an additional, previously undiscovered phylogenetic lineage and revealed similar pH-associated distribution patterns at global, regional, and local scales, which were most evident for the five most abundant clusters. Archaeal
amoA
abundance and diversity increased with soil pH, which was the only physicochemical characteristic measured that significantly influenced community structure. These results suggest evolution based on specific adaptations to soil pH and niche specialization, resulting in a global distribution of archaeal lineages that have important consequences for soil ecosystem function and nitrogen cycling.
Structural analysis of the core COMPASS family of histone H3K4 methylases from yeast to human
Authors: Takahashi Yoh-hei , Westfield Gerwin H. , Oleskie Austin N. , Trievel Raymond C. , Shilatifard Ali , Skiniotis Georgios
Published: December 2011

Histone H3 lysine 4 (H3K4) methylation is catalyzed by the highly evolutionarily conserved multiprotein complex known as Set1/COMPASS or MLL/COMPASS-like complexes from yeast to human, respectively. Here we have reconstituted fully functional yeast Set1/COMPASS and human MLL/COMPASS-like complex in vitro and have identified the minimum subunit composition required for histone H3K4 methylation. These subunits include the methyltransferase C-terminal SET domain of Set1/MLL, Cps60/Ash2L, Cps50/RbBP5, Cps30/WDR5, and Cps25/Dpy30, which are all common components of the COMPASS family from yeast to human. Three-dimensional (3D) cryo-EM reconstructions of the core yeast complex, combined with immunolabeling and two-dimensional (2D) EM analysis of the individual subcomplexes reveal a Y-shaped architecture with Cps50 and Cps30 localizing on the top two adjacent lobes and Cps60-Cps25 forming the base at the bottom. EM analysis of the human complex reveals a striking similarity to its yeast counterpart, suggesting a common subunit organization. The SET domain of Set1 is located at the juncture of Cps50, Cps30, and the Cps60-Cps25 module, lining the walls of a central channel that may act as the platform for catalysis and regulative processing of various degrees of H3K4 methylation. This structural arrangement suggested that COMPASS family members function as exo-methylases, which we have confirmed by in vitro and in vivo studies.
Protein conformational dynamics in the mechanism of HIV-1 protease catalysis
Authors: Torbeev Vladimir Yu. , Raghuraman H. , Hamelberg Donald , Tonelli Marco , Westler William M. , Perozo Eduardo , Kent Stephen B. H.
Published: December 2011

We have used chemical protein synthesis and advanced physical methods to probe dynamics-function correlations for the HIV-1 protease, an enzyme that has received considerable attention as a target for the treatment of AIDS. Chemical synthesis was used to prepare a series of unique analogues of the HIV-1 protease in which the flexibility of the “flap” structures (residues 37–61 in each monomer of the homodimeric protein molecule) was systematically varied. These analogue enzymes were further studied by X-ray crystallography, NMR relaxation, and pulse-EPR methods, in conjunction with molecular dynamics simulations. We show that conformational isomerization in the flaps is correlated with structural reorganization of residues in the active site, and that it is preorganization of the active site that is a rate-limiting factor in catalysis.
Crystal structure of the mucosa-associated lymphoid tissue lymphoma translocation 1 (MALT1) paracaspase region
Authors: Yu Jong W. , Jeffrey Philip D. , Ha Jun Yong , Yang Xiaolu , Shi Yigong
Published: December 2011

The mucosa-associated lymphoid tissue lymphoma translocation 1 (MALT1) paracaspase, a key component of the Carma1/Bcl10/MALT1 signalosome, is critical for NF-κB signaling in multiple contexts. MALT1 is thought to function as a scaffold and protease to promote signaling; however, the biochemical and structural basis of paracaspase action remains largely unknown. Here we report the 1.75-Å resolution crystal structure of the MALT1 paracaspase region, which contains the paracaspase domain and an ensuing Ig-like domain. The paracaspase and the Ig domains appear as a single folding unit and interact with each other through extensive van der Waals contacts and hydrogen bonds. The paracaspase domain adopts a fold that is nearly identical to that of classic caspases and homodimerizes similarly to form an active protease. Unlike caspases, the active and mature form of the paracaspase domain remains a single uncleaved polypeptide and specifically recognizes the bound peptide inhibitor Val-Arg-Pro-Arg. In particular, the carboxyl-terminal amino acid Arg of the inhibitor is coordinated by three highly conserved acidic residues. This structure serves as an important framework for deciphering the function and mechanism of paracaspases exemplified by MALT1.
Coupling mammalian cell surface display with somatic hypermutation for the discovery and maturation of human antibodies
Authors: Bowers Peter M. , Horlick Robert A. , Neben Tamlyn Y. , Toobian Rachelle M. , Tomlinson Geoffrey L. , Dalton Jennifer L. , Jones Heather A. , Chen Andy , Altobell Laurence , Zhang Xue , Macomber John L. , Krapf Irina P. , Wu Betty F. , McConnell Audrey , Chau Betty , Holland Trevin , Berkebile Ashley D. , Neben Steven S. , Boyle William J. , King David J.
Published: December 2011

A novel approach has been developed for the isolation and maturation of human antibodies that replicates key features of the adaptive immune system by coupling in vitro somatic hypermutation (SHM) with mammalian cell display. SHM is dependent on the action of the B cell specific enzyme, activation-induced cytidine deaminase (AID), and can be replicated in non-B cells through expression of recombinant AID. A library of human antibodies, based on germline V-gene segments with recombined human

regions was used to isolate low-affinity antibodies to human β nerve growth factor (hβNGF). These antibodies, initially naïve to SHM, were subjected to AID-directed SHM in vitro and selected using the same mammalian cell display system, as illustrated by the maturation of one of the antibodies to low pM
K
D
. This approach overcomes many of the previous limitations of mammalian cell display, enabling direct selection and maturation of antibodies as full-length, glycosylated IgGs.
Whole-exome sequencing of neoplastic cysts of the pancreas reveals recurrent mutations in components of ubiquitin-dependent pathways
Authors: Wu Jian , Jiao Yuchen , Dal Molin Marco , Maitra Anirban , de Wilde Roeland F. , Wood Laura D. , Eshleman James R. , Goggins Michael G. , Wolfgang Christopher L. , Canto Marcia I. , Schulick Richard D. , Edil Barish H. , Choti Michael A. , Adsay Volkan , Klimstra David S. , Offerhaus G. Johan A. , Klein Alison P. , Kopelovich Levy , Carter Hannah , Karchin Rachel , Allen Peter J. , Schmidt C. Max , Naito Yoshiki , Diaz Luis A. , Kinzler Kenneth W. , Papadopoulos Nickolas , Hruban Ralph H. , Vogelstein Bert
Published: December 2011

More than 2% of adults harbor a pancreatic cyst, a subset of which progresses to invasive lesions with lethal consequences. To assess the genomic landscapes of neoplastic cysts of the pancreas, we determined the exomic sequences of DNA from the neoplastic epithelium of eight surgically resected cysts of each of the major neoplastic cyst types: serous cystadenomas (SCAs), intraductal papillary mucinous neoplasms (IPMNs), mucinous cystic neoplasms (MCNs), and solid pseudopapillary neoplasms (SPNs). SPNs are low-grade malignancies, and IPMNs and MCNs, but not SCAs, have the capacity to progress to cancer. We found that SCAs, IPMNs, MCNs, and SPNs contained 10 ± 4.6, 27 ± 12, 16 ± 7.6, and 2.9 ± 2.1 somatic mutations per tumor, respectively. Among the mutations identified, E3 ubiquitin ligase components were of particular note. Four of the eight SCAs contained mutations of the von Hippel–Lindau gene (VHL), a key component of theVHLubiquitin ligase complex that has previously been associated with renal cell carcinomas, SCAs, and other neoplasms. Six of the eight IPMNs and three of the eight MCNs harbored mutations ofRNF43, a gene coding for a protein with intrinsic E3 ubiquitin ligase activity that has not previously been found to be genetically altered in any human cancer. The preponderance of inactivating mutations inRNF43unequivocally establish it as a suppressor of both IPMNs and MCNs. SPNs contained remarkably few genetic alterations but always contained mutations ofCTNNB1, previously demonstrated to inhibit degradation of the encoded protein (β-catenin) by E3 ubiquitin ligases. These results highlight the essential role of ubiquitin ligases in these neoplasms and have important implications for the diagnosis and treatment of patients with cystic tumors.
Personal and family perfectionism of Taiwanese college students: Relationships with depression, self‐esteem, achievement motivation, and academic grades
Authors: Wang Kenneth T.
Published: December 2011

An increasing number of perfectionism studies have been conducted across different countries outside of the Western framework. Using an international egalitarian approach that adopts indigenous frameworks and concepts from the cultural context of the population studied is imperative. This study examines different groups of perfectionists with a sample of 348 Taiwanese college students, emphasizing the collectivistic culture. In particular, this is a follow‐up study to further explore characteristics of a group with low standards/high discrepancy—a feeling that they are not good enough despite having low standards—found in a previous study with Taiwanese students. More specifically, this study investigates whether the source of the high discrepancy scores among this group is related to having higher perfectionistic standards from their family. Perfectionism was examined not only from a personal/individualistic perspective, but also from a familistic dimension to reflect Taiwanese collectivistic cultural values. Results partially supported the hypotheses—this group reported having higher family discrepancy, but not family standards, than nonperfectionists. However, this group of participants reported lower academic grades, which implies the possibility of their discrepancy being associated with poorer performance. Four cluster groups—adaptive perfectionists, maladaptive perfectionists, nonperfectionists, and those with low standards/high discrepancy—were compared on their levels of depression, self‐esteem, achievement motivation, and academic grades. Maladaptive perfectionists reported the highest depression level, while adaptive perfectionists reported the highest self‐esteem. Results also show that aspects of personal perfectionism and family perfectionism related to self‐esteem differently among this sample. Findings and implications are discussed with consideration of the collectivistic cultural context in Taiwan.
Lack of association of the ACE genotype with the muscle strength response to resistance training
Authors: Gentil Paulo , Lima Ricardo M. , Pereira Rinaldo Wellerson , Mourot Julia , Leite Tailce Kaley , Bottaro Martim
Published: December 2011

Introduction: Previous studies have attempted to link the insertion/deletion (I/D) polymorphism in the angiotensin‐converting enzyme (ACE) gene with the variability in muscle strength responses to resistance training (RT); however, the literature is inconclusive. The purpose of the present study was to investigate the association between the ACE I/D genotype and muscle strength response to a RT program in young men.

Methods: 124 men (22±2.6 years; 174.8±6.5cm; 71.5±13.8 kg) without resistance training experience were tested before and after 11 weeks of five whole‐body RT exercises (bench press, seated row, knee extension, knee flexion and sit ups). The bench press 1RM test was used to assess upper‐body muscle strength and the isokinetic knee extensor peak torque (PT) was used as a measure of lower‐body strength.

Results: At baseline, there were no differences among ACE genotype for 1RM load (54±11.7 kg for II, 58.5±8.9 kg for ID and 52.3±12.2 kg for DD) or knee extensor peak torque (PT) (220.1±36.8 N·m for II, 209.4 ±44.4 N·m for ID and 199.7±32.4 N·m for DD). Moreover, ACE genotype was not associated with lower‐body (7.1±10.5%, 15.7±10.4% and 14.1±22.7% for II, ID and DD, respectively) or upper‐body strength gains (16.2±8.9%, 14.5±11.3% and 21.9±17.1% for II, ID and DD, respectively) in response to RT.

Conclusion: The ACE I/D genotype was not associated with the muscle strength responses to RT.
Evaluation of mean power spectral frequency of EMG signal during 100 metre crawl
Authors: Stirn Igor , Jarm Tomaz , Kapus Venceslav Peter , Strojnik Vojko
Published: December 2011

The aim of our study was to compare mean frequency (MNF) decrease in some upper body muscles during a 100‐metre all‐out crawl by using two different normalization methods: firstly, when MNF at the end of swimming (MNFSend) was normalized with respect to its initial value at the beginning and expressed with a fatigue index (FI) labelled FIstart, and secondly when MNFmin was used to calculate FImin. MNFmin presented the lowest MNF obtained during isometric contractions until exhaustion executed on land after swimming for each of three observed muscles – triceps brachii (TB), latissimus dorsi (LD) and pectoralis major (PM). Eleven experienced swimmers participated in the study and surface electromyography (EMG) signals from TB, the upper and lower parts of LD (LD1 and LD2 respectively) and the upper and lower parts of PM (PM1 and PM2 respectively) were recorded during both swimming and isometric contractions. Results showed no differences in FIstart; however, when FImin values were compared differences between the muscles were found (P<0.05). The triceps brachii (TB) and the upper part of the latissimus dorsi muscles (LD1) showed the lowest FImin (40.0±15.7 and 40.7±24.4 respectively), which implied that MNFSend obtained from these muscles most closely approached their respective MNFmin values during swimming. This might suggest that these muscles fatigued more than other observed muscles. The use of a different type of muscle contraction for calculating FImin (isometric versus dynamic) might represent a drawback to our study, but this approach could be acceptable when between‐muscle comparisons are made.
Thermal conductivity of aluminium nitride thin films prepared by reactive magnetron sputtering
Authors: Duquenne C , Besland M-P , Tessier P Y , Gautron E , Scudeller Y , Averty D
Published: December 2011

The relationship between thermal conductivity and microstructures of aluminium nitride films is reported. Films were deposited on silicon substrates by magnetron sputtering of a pure Al target in nitrogen argon plasma at low temperatures (<300 °C) with thickness ranging from 150 to 3500 nm. Balanced and unbalanced magnetron configurations were used for different nitrogen contents in the gas phase. Various microstructures were thus created and their thermal conductivity was measured with the transient hot strip technique. Depending on the crystalline structure of the films, the bulk thermal conductivity of the AlN films at room temperature varied between 2 and 170 W m−1 K−1. Unbalanced magnetron allowed achieving highly dense (0 0 2) oriented AlN films with a grain size in the 100 nm range, a low oxygen content close to 0.5 at% and a resulting bulk thermal conductivity as high as 170 W m−1 K−1. Such a crystalline quality resulted from the ion energy involved in the growth process. In contrast, balanced magnetron led to weakly textured AlN films containing 5 at% oxygen with a grain size in the 30 nm range and a resulting thermal conductivity ranging from 2 to 100 W m−1 K−1 depending on the microstructure. Otherwise, the thermal boundary resistance between AlN films deposited by unbalanced magnetron and the silicon substrate was found to be as low as 1.0 × 10−8 K m2 W−1. Such a value was in good agreement with the thickness of the interfacial amorphous layer determined in the 2 nm range by high resolution transmission electron microscopy.
Long noncoding RNA-mediated anti-apoptotic activity in murine erythroid terminal differentiation
Authors: Hu Wenqian , Yuan Bingbing , Flygare Johan , Lodish Harvey F.
Published: December 2011

Long noncoding RNAs (lncRNAs) are differentially expressed under both normal and pathological conditions, implying that they may play important biological functions. Here we examined the expression of lncRNAs during erythropoiesis and identified an erythroid-specific lncRNA with anti-apoptotic activity. Inhibition of this lncRNA blocks erythroid differentiation and promotes apoptosis. Conversely, ectopic expression of this lncRNA can inhibit apoptosis in mouse erythroid cells. This lncRNA represses expression of Pycard, a proapoptotic gene, explaining in part the inhibition of programmed cell death. These findings reveal a novel layer of regulation of cell differentiation and apoptosis by a lncRNA.
Randomised clinical trial: the effectiveness of Lactobacillus reuteri ATCC 55730 rectal enema in children with active distal ulcerative colitis
Authors: Oliva S. , Di Nardo G. , Ferrari F. , Mallardo S. , Rossi P. , Patrizi G. , Cucchiara S. , Stronati L.
Published: December 2011

Background  Intestinal microbiota manipulation, one of the pathogenetic components of inflammatory bowel disease (IBD), has become an attractive therapy for ulcerative colitis (UC).

Aim  To assess in children with active distal UC the effectiveness of Lactobacillus (L) reuteri ATCC 55730 enema on inflammation and cytokine expression of rectal mucosa.

Methods  A total of 40 patients (median age: 7.2 years range 6–18) with mild to moderate UC were enrolled in a prospective, randomised, placebo‐controlled study. They received an enema solution containing 1010 CFU of L. reuteri ATCC 55730 or placebo for 8 weeks, in addition to oral mesalazine. Clinical endoscopic and histological scores as well as rectal mucosal expression levels of IL‐10, IL‐1β, TNFα and IL‐8 were evaluated at the beginning and at the end of the trial.

Results  Thirty‐one patients accomplished the trial (17 males, median age 13 year, range 7–18). Mayo score (including clinical and endoscopic features) decreased significantly in the L. reuteri group (3.2 ± 1.3 vs. 8.6 ± 0.8, P < 0.01) compared with placebo (7.1 ± 1.1 vs. 8.7 ± 0.7, NS); furthermore, histological score significantly decrease only in the L. reuteri group (0.6 ± 0.5 vs. 4.5 ± 0.6, P < 0.01) (placebo: 2.9 ± 0.8 vs. 4.6 ± 0.6, NS). At the post‐trial evaluation of cytokine mucosal expression levels, IL‐10 significantly increased (P < 0.01) whereas IL‐1β, TNFα and IL‐8 significantly decreased (P < 0.01) only in the L. reuteri group.

Conclusions  In children with active distal ulcerative colitis, rectal infusion of L. reuteri is effective in improving mucosal inflammation and changing mucosal expression levels of some cytokines involved in the mechanisms of inflammatory bowel disease.
Transglutaminase 2 expression is enhanced synergistically by interferon-γ and tumour necrosis factor-α in human small intestine
Authors: Bayardo M , Punzi F , Bondar C , Chopita N , Chirdo F
Published: December 2011

Transglutaminase 2 (TG2) is expressed ubiquitously, has multiple physiological functions and has also been associated with inflammatory diseases, neurodegenerative disorders, autoimmunity and cancer. In particular, TG2 is expressed in small intestine mucosa where it is up-regulated in active coeliac disease (CD). The aim of this work was to investigate the induction of TG2 expression by proinflammatory cytokines [interleukin (IL)-1, IL-6, tumour necrosis factor (TNF)-α, interferon (IFN)-γ and IL-15] and the signalling pathways involved, in human epithelial and monocytic cells and in intestinal tissue from controls and untreated CD patients. Here we report that IFN-γ was the most potent inducer of TG2 expression in the small intestinal mucosa and in four [Caco-2, HT-29, Calu-6 and human acute monocytic leukaemia cell line (THP-1)] of five cell lines tested. The combination of TNF-α and IFN-γ produced a strong synergistic effect. The use of selective inhibitors of signalling pathways revealed that induction of TG2 by IFN-γ was mediated by phosphoinositide 3-kinase (PI3K), while c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) were required for TNF-α activation. Quantitative polymerase chain reaction (PCR), flow cytometry and Western blot analysis showed that TG2 expression was blocked completely when stimulation by either TNF-α or IFN-γ was performed in the presence of nuclear factor (NF)-κB inhibitors (sulphasalazine and BAY-117082). TG2 was up-regulated substantially by TNF-α and IFN-γ in intestinal mucosa in untreated CD compared with controls. This study shows that IFN-γ, a dominant cytokine in intestinal mucosa in active CD, is the most potent inducer of TG2, and synergism with TNF-α may contribute to exacerbate the pathogenic mechanism of CD. Selective inhibition of signalling pathways may be of therapeutic benefit.
Chemical composition, rumen degradability and crude protein fractionation of some commercial and improved cowpea (Vigna unguiculata L. Walp) haulm varieties
Authors: Anele U. Y. , Südekum K.‐H. , Arigbede O. M. , Lüttgenau H. , Oni A. O. , Bolaji O. J. , Galyean M. L.
Published: December 2011

Seasonal chemical composition, in sacco organic matter (OM) and crude protein (CP) degradabilities and CP fractions of haulms of three improved (ITA2, ITA6 and ITA8) and three commercial (Oloyin, Peu and Sokoto) cowpea varieties harvested in wet and dry seasons were evaluated in a 2 × 2 factorial arrangement of treatments. Effective degradation of OM and CP was estimated at assumed outflow rates of 2 and 4% h−1. Commercial haulms (all the other parts of the cowpea minus the grains) had greater (P < 0·001) CP than improved varieties, whereas neutral detergent fibre and acid detergent fibre were greater (P < 0·001) in improved vs. commercial haulms. Interactions between variety group (improved vs. commercial) and season were observed for CP (P = 0·002), lignin (P = 0·003) and hemicellulose (P = 0·030) contents of the haulms. Similarly, a group × season interaction was observed for effective degradation of OM at an outflow rate of 2%. The proportion of substrate degraded in the samples harvested in the wet season was generally less (P < 0·001) than in the dry season. Effective degradability values of OM at the assumed passage rates were greater (P < 0·001) for improved vs. commercial cowpea haulms. Interactions between group and season were observed for all but one of the CP fractions. Seasonal differences in the quality of haulms showed that attention must be given to handling of haulms to minimize the amount of leaves lost during the wet season.
The effect of training administered to working mothers on maternal anxiety levels and breastfeeding habits
Authors: Çiftçi Esra K , Arikan Duygu
Published: December 2011

Aim and objective.  This study was conducted to determine the effect of training administered to working mothers and its duration on maternal anxiety levels and breastfeeding habits.

Background.  Within the scope of Health for All in the 21st Century project, a goal was set to increase the rate of infants fed exclusively by breastfeeding during the first six months of life to 80% by the year 2015.

Design.  A randomised design with repeated measures.

Methods.  During collection of pretest data, a Personal Information Form, a Questionnaire Form and a State Trait Anxiety Inventory were administered to the mothers in the experimental and control groups. Five home visits were conducted starting two weeks before the date when mothers returned to work and ending when the infants became six months old. Breastfeeding techniques were taught to these mothers. Data were subjected to Proc MEAN, FREQ, anova and GENMOD procedures.

Results.  The rate of natural feeding (breastfeeding exclusively) among trained mothers was greater than untrained mothers. The frequency of breastfeeding affects maternal anxiety levels; the anxiety level of mothers decreased with increasing frequency of breastfeeding.

Conclusion.  Educating working mothers about breastfeeding reduces their anxiety levels and influences positively their breastfeeding habits.

Relevance to clinical practice.  With the support of health‐care staff to increase awareness and knowledge on the value and sufficiency of breast milk, the rate and period of natural feeding increased significantly among working mothers.
Modelling photosynthetic responses to temperature of grapevine (Vitis vinifera cv. Semillon) leaves on vines grown in a hot climate
Authors: GREER DENNIS H. , WEEDON MARK M.
Published: December 2011

Field measurements of photosynthesis of Vitis vinifera cv. Semillon leaves in relation to a hot climate, and responses to photon flux densities (PFDs) and internal CO2 concentrations (ci) at leaf temperatures from 20 to 40 °C were undertaken. Average rates of photosynthesis measured in situ decreased with increasing temperature and were 60% inhibited at 45 °C compared with 25 °C. This reduction in photosynthesis was attributed to 15–30% stomatal closure. Light response curves at different temperatures revealed light‐saturated photosynthesis optimal at 30 °C but also PFDs saturating photosynthesis increased from 550 to 1200 µmol (photons) m−2 s−1 as temperatures increased. Photosynthesis under saturating CO2 concentrations was optimal at 36 °C while maximum rates of ribulose 1,5‐bisphosphate (RuBP) carboxylation (Vcmax) and potential maximum electron transport rates (Jmax) were also optimal at 39 and 36 °C, respectively. Furthermore, the high temperature‐induced reduction in photosynthesis at ambient CO2 was largely eliminated. The chloroplast CO2 concentration at the transition from RuBP regeneration to RuBP carboxylation‐limited assimilation increased steeply with an increase in leaf temperature. Semillon assimilation in situ was limited by RuBP regeneration below 30 °C and above limited by RuBP carboxylation, suggesting high temperatures are detrimental to carbon fixation in this species.
Tectono‐sedimentary evolution of the ‘Numidian Formation’ and Lateral Facies (southern branch of the western Tethys): constraints for central‐western Mediterranean geodynamics
Authors: Guerrera Francesco , Martín‐Algarra Agustín , Martín‐Martín Manuel
Published: December 2011

Terra Nova, 24, 34–41, 2012

The origin of the Numidian Formation (latest Oligocene to middle Miocene), characterized by ultra‐mature quartzose arenites with abundant well‐rounded frosted quartz grains, remains controversial. This formation, sedimented in the external domain of the Maghrebian Flysch Basin, displays three characteristic stratigraphic members with marked longitudinal (proximal–distal) and transverse (along‐chain) variations with palaeogeographical importance. The origin of the Numidian supply is related to the outward tectogenetic propagation when a forebulge evolved in the African foreland, leading to the erosion of African cratonic areas rich in quartzose arenites (Nubian Sandstone‐like). The ages of the Numidian Formation checked by Betic, Maghrebian and Southern Apennine data suggest a timing for the accretionary orogenic wedge, earlier in the Betic‐Rifian Arc (after middle Burdigalian), later in the Algerian‐Tunisian Tell (after late Burdigalian) and afterwards in Sicily and the Southern Apennines (after Langhian). A geodynamic evolutionary model for the central‐western Mediterranean is proposed.
Leptoglossus occidentalis and Diplodia pinea: a new insect‐fungus association in Mediterranean forests
Authors: Luchi N. , Mancini V. , Feducci M. , Santini A. , Capretti P.
Published: December 2011

Leptoglossus occidentalis, an insect native to North America, was inadvertently introduced into Italy about 1999. The insect damages the cones of conifer trees, especially Pinus pinea (Italian Stone pine). Pinus pinea is also affected by Diplodia pinea, a fungus native to Italy, which is becoming an increasing threat because pine trees are becoming more susceptible to it as a consequence of global warming. Because the insect and the fungus both have the pine cones as a common habitat, a possible interaction between them has been postulated. The aim of this study was to ascertain whether L. occidentalis and D. pinea interact on P. pinea cones. The interaction was studied using real‐time PCR on a group of naturally infected insects collected from a forest, and a group raised in the laboratory and artificially inoculated with D. pinea conidia. Molecular analysis showed that D. pinea DNA occurred on both naturally infected and inoculated insects, but with significant differences between the two groups. The rapid and sensitive molecular technique made it possible to detect D. pinea DNA on the bodies of the insects, and to show that the native D. pinea occurred on the exotic insect.
Targeting gaseous molecules to protect against cerebral ischaemic injury: Mechanisms and prospects
Authors: Zhou Jun , Wu Peng‐Fei , Wang Fang , Chen Jian‐Guo
Published: December 2011

Ischaemic brain injury is a leading cause of death and disability in many countries. However, the pathological mechanisms underlying ischaemic brain injury, including oxidative stress, calcium overload, excitotoxicity and neuronal apoptosis, are perplexing and this makes it difficult to find effective novel drugs for the treatment of the condition.

Recently, gaseous molecules such as nitric oxide (NO), carbon monoxide (CO), hydrogen sulphide (H2S) and hydrogen (H2) have attracted considerable interest because of their physiological and pathophysiological roles in various body systems. Emerging evidence indicates that gaseous molecules are involved in the pathological processes of ischaemic brain damage.

In the present review, we summarize evidence regarding the involvement of gaseous molecules in ischaemic brain injury and discuss the therapeutic potential of targeting gaseous molecules.

Collectively, the available data suggest that the application of these biological gas molecules and their pharmacological regulators may be a potential therapeutic approach for the treatment of ischaemic brain injury.