bluuebunny/crossref_metadata_2025 huggingface dataset:
Composite Images of Upper Front Teeth—Judgment of Attractiveness and Gender‐Specific Correlation
Authors: Wolfart Stefan , Lawrenz Birger , Schley Jaana‐Sophia , Kern Matthias , Springer Ingo
Published: January 2014

The esthetic appearance of upper front teeth strongly depends on color, shape, size, width‐to‐height ratio, and position of teeth. In the past, these single esthetic aspects had been analyzed separately and not as a whole. Thus, the objective of this current study is to investigate the perception of the esthetics of upper front teeth whose image had been manipulated by composite photoimaging. In order to obtain the six composite images, one for each gender and group (“discontent,” “average,” and “content”), 320 students were photographed. Afterwards, the 6 composite images were rated by 128 independent participants (dentists and laymen), concerning attractiveness and gender. The composite images “average” and “content” were rated significantly more attractive than “discontent” images. The composite images rated as “attractive” were attributed to the female gender by the majority of the participants (61–85%); the “unattractive” images were predominantly (85–75%) related to the male gender. The participants were unable to judge the correct gender yet they assigned attractiveness to be a clearly female attribute. This “bias” can be utilized for the reconstruction upper front teeth, to emphasize the gender of the patient.

Clinical Significance

The presented morphing technique can contribute to further study setups considering dental appearance and attractiveness. In the case of restoring upper front teeth, the parameters tooth shape, size, width‐to‐height ratio, and position of teeth should be individually chosen and can emphasize or dampen the perception of gender.
Molecular mechanisms underlying phosphate sensing, signaling, and adaptation in plants
Authors: Zhang Zhaoliang , Liao Hong , Lucas William J.
Published: January 2014

As an essential plant macronutrient, the low availability of phosphorus (P) in most soils imposes serious limitation on crop production. Plants have evolved complex responsive and adaptive mechanisms for acquisition, remobilization and recycling of phosphate (Pi) to maintain P homeostasis. Spatio‐temporal molecular, physiological, and biochemical Pi deficiency responses developed by plants are the consequence of local and systemic sensing and signaling pathways. Pi deficiency is sensed locally by the root system where hormones serve as important signaling components in terms of developmental reprogramming, leading to changes in root system architecture. Root‐to‐shoot and shoot‐to‐root signals, delivered through the xylem and phloem, respectively, involving Pi itself, hormones, miRNAs, mRNAs, and sucrose, serve to coordinate Pi deficiency responses at the whole‐plant level. A combination of chromatin remodeling, transcriptional and posttranslational events contribute to globally regulating a wide range of Pi deficiency responses. In this review, recent advances are evaluated in terms of progress toward developing a comprehensive understanding of the molecular events underlying control over P homeostasis. Application of this knowledge, in terms of developing crop plants having enhanced attributes for P use efficiency, is discussed from the perspective of agricultural sustainability in the face of diminishing global P supplies.
The FRIENDS Emotional Health Program for Minority Groups at Risk
Authors: Iizuka Cristina A. , Barrett Paula M. , Gillies Robyn , Cook Clayton R. , Miller Debbie
Published: January 2014

BACKGROUND

Despite the existence of evidence‐based interventions for promoting mental health in children, the number of children at risk remains high. One of the reasons is that such interventions are not reaching specific groups at risk such as low socioeconomic status and ethnic minority groups. This study evaluated an adaptation of a school‐based psychosocial program for nonreferred students aged 11 to 12 years attending a multicultural school from a low socioeconomic status area.

METHODS

The FRIENDS Program was adapted for a multicultural population. A quasi‐experimental design was used, involving a pre/post‐test, to evaluate the impact of the intervention on participants' outcomes on the Strengths and Difficulties Questionnaire (SDQ). Participants were divided into 2 categories (“at risk”/“not at risk”) based on their scores in the SDQ at pre‐test. Post‐test data were collected to evaluate the overall effectiveness and acceptability of the program.

RESULTS

Analyses showed significant improvement for the group initially identified as “at risk,” with 30% of the students being no longer at risk after the intervention. Most students rated the intervention as being highly acceptable and useful.

CONCLUSIONS

Adaptations to existing evidence‐based programs for implementation with specific minority groups at risk represents a promising approach to promote emotional health in children.
The Role of Social Support for Promoting Quality of Life Among Persistently Obese Adolescents: Importance of Support in Schools
Authors: Wu Yelena P. , Reiter‐Purtill Jennifer , Zeller Meg H.
Published: January 2014

BACKGROUND

Despite school‐based and other interventions for pediatric obesity, many obese youth of the present generation will persist in their obesity into adolescence and adulthood. Thus, understanding not only how better to tailor weight interventions but how to promote overall adjustment for persistently obese youth is of utmost importance. This study examined the role of perceived social support in predicting later psychosocial status (ie, weight‐related quality of life) for persistently obese adolescents.

METHODS

This study used a longitudinal design whereby persistently obese and nonoverweight comparison youth completed measures at 2 time points approximately 4 years apart.

RESULTS

Obese youth reported lower levels of social support than comparison youth. Among obese youth, classmate and teacher support predicted future weight‐related quality of life.

CONCLUSIONS

Social support, particularly from classmates, is an important predictor for the longitudinal psychosocial functioning of persistently obese youth. High levels of perceived teacher support may signal the presence of other psychosocial difficulties. Implications for school‐based interventions are discussed.
Using Bayesian growth models to reconstruct small‐mammal populations during low‐trapping periods
Authors: Unnsteinsdottir E. R. , Hersteinsson P. , Jonasson J. P. , McAdam B. J.
Published: January 2014

Small‐mammal populations that fluctuate in size often undergo periods of low trappability, which could be an important factor contributing to low‐density estimates based on trapping efforts. Age cohort analysis is commonly used to estimate population parameters of animals that are harvested. The method is based on known age at death that can be used for Bayesian hierarchical growth models. It is interesting to see if similar methods, hitherto conducted on long‐living species, can be used on live‐trapping data on short‐lived and fast‐growing small mammals. Using data from live‐trapping surveys of Apodemus sylvaticus in Iceland, we adjusted growth curves to individual body weights to predict their birth dates. The estimated birth dates were used to estimate population density and recruitment. These were then compared with other data sources. We found out that density estimates, based on numerical methods [modified nodal analysis (MNA)], underestimated population density during the period of low trappability and that recruitment occurred up to 100 days earlier than was observed by capture‐mark‐recapture (CMR) analysis and MNA. This study suggests that cohort analysis can be conducted on short‐lived small mammals during periods when estimates based on CMR or numerical analysis fail because of low sample sizes. Furthermore, it is possible to use body weight of live‐trapped individuals to estimate age. This is important in terms of ethics and conservation as such methods can be conducted without harming or killing the animals. We believe that live‐trapping data obtained during a peak period in population density can be a useful aid when describing population parameters of previous months when low trappability prevents direct measurements.
Living with xeroderma pigmentosum: comprehensive photoprotection for highly photosensitive patients
Authors: Tamura Deborah , DiGiovanna John J. , Khan Sikandar G. , Kraemer Kenneth H.
Published: January 2014

Xeroderma pigmentosum (XP) is a rare autosomal recessive disease of deoxyribonucleic acid (DNA) repair with ultraviolet (UV) radiation sensitivity and a 10 000‐fold increased risk of skin cancer. Symptoms include: freckle‐like pigmentation in sun‐exposed skin before age 2 years, severe burns after minimal sun exposure (50% of patients) and damage to exposed surfaces of the eyes with loss of vision and ocular cancer. About 25% of patients develop a progressive neurodegeneration. The combination of an inherited inability to repair UV‐induced DNA damage and environmental exposure to UV must occur for cutaneous and ocular symptoms to develop. There is no cure for XP, but many of its manifestations may be reduced or prevented through consistent UV protection; thus XP serves as a model for sun protection of patients with marked photosenstivity. Sun protective clothing including hats, sunglasses and face shields, sun screen lotions and avoidance of environmental sources of UV are cornerstones of prevention of skin and eye damage and cancer. Although XP is a serious disease with the potential for limitation of life expectancy, XP patients can live active lives while at the same time avoiding UV.
Productivity Gains and Spillovers from Offshoring
Authors: Michel Bernhard , Rycx François
Published: January 2014

Offshoring is generally believed to be productivity enhancing and this belief is underpinned by economic theory. This paper estimates the impact of materials and business services offshoring on productivity in Belgium over the period 1995–2004. It contributes to the literature: (i) by examining this issue separately for manufacturing and market services industries and (ii) by investigating the possibility of forward and backward spillovers from offshoring, i.e. that productivity gains from offshoring feed through to upstream and downstream industries. Results show that materials offshoring has no effect on productivity, while business services offshoring leads to productivity gains in manufacturing. Furthermore, there is no evidence of either forward or backward spillovers from offshoring.
Glycinergic feedback enhances synaptic gain in the distal retina
Authors: Jiang Zheng , Yang Jinnan , Purpura Lauren A. , Liu Yufei , Ripps Harris , Shen Wen
Published: January 2014

Key points

This study provides experimental evidence that glycinergic interplexiform cells create a centrifugal feedback loop in the vertebrate retina that regulates the transmission of glutamatergic signals between photoreceptors and second‐order neurons.

This mechanism serves to reduce glutamate uptake and enhance glutamate release.

Glycine receptors containing the GlyRα3 subunit are expressed on bipolar cell dendrites, and their activation leads to a depolarizing response in a group of rod‐dominated ON bipolar cells, and hyperpolarizing responses in OFF bipolar cells.

Using strychnine to block endogenous glycine feedback reduces the amplitudes of light‐evoked responses in both ON and OFF bipolar cells, indicating that glycine feedback regulates signal propagation in the distal retina.

Glycinergic feedback provides a neural mechanism that enhances synaptic gain and improves visual sensitivity.

Glycine input originates with interplexiform cells, a group of neurons situated within the inner retina that transmit signals centrifugally to the distal retina. The effect on visual function of this novel mechanism is largely unknown. Using gramicidin‐perforated patch whole cell recordings, intracellular recordings and specific antibody labelling techniques, we examined the effects of the synaptic connections between glycinergic interplexiform cells, photoreceptors and bipolar cells. To confirm that interplexiform cells make centrifugal feedback on bipolar cell dendrites, we recorded the postsynaptic glycine currents from axon‐detached bipolar cells while stimulating presynaptic interplexiform cells. The results show that glycinergic interplexiform cells activate bipolar cell dendrites that express the α3 subunit of the glycine receptor, as well as a subclass of unidentified receptors on photoreceptors. By virtue of their synaptic contacts, glycine centrifugal feedback increases glutamate release from photoreceptors and suppresses the uptake of glutamate by the type 2A excitatory amino acid transporter on photoreceptors. The net effect is a significant increase in synaptic gain between photoreceptors and their second‐order neurons.
The selectivity of rostroventral medulla descending control of spinal sensory inputs shifts postnatally from A fibre to C fibre evoked activity
Authors: Koch Stephanie C. , Fitzgerald Maria
Published: January 2014

Key points

Brainstem descending pathways control the balance of excitation and inhibition in spinal sensory networks. In adult rodents, descending inhibition is targeted to spinal neurons with a strong afferent C fibre input.

Descending inhibitory control matures slowly; the first postnatal weeks are characterized by greater descending facilitation than inhibition.

We report that, in contrast to adults, brainstem descending facilitation of spinal sensory neurons in young rats (postnatal day 21) is targeted to A fibre inputs. The selective inhibition of C fibre inputs observed in adults is absent at postnatal day 21.

In both young and adult rats, descending inhibition or facilitation is correlated with the excitability of individual neurons, as measured by ‘wind‐up’ to repeated C fibre stimulation.

The facilitation of A fibre input in early life is likely to enhance innocuous, tactile sensory inputs to the dorsal horn in the critical early postnatal weeks and thus promote activity‐dependent development of sensory networks.

Brainstem descending control is crucial in maintaining the balance of excitation and inhibition in spinal sensory networks. In the adult, descending inhibition of spinal dorsal horn circuits arising from the brainstem rostroventral medial medulla (RVM) is targeted to neurons with a strong nociceptive C fibre input. Before the fourth postnatal week, the RVM exerts a net facilitation of spinal networks but it is not known if this is targeted to specific dorsal horn neuronal inputs. As the maturation from descending facilitation to inhibition occurs only after C fibre central synaptic maturation is complete, we hypothesized that RVM facilitation in young animals is targeted to A fibre afferent inputs. To test this, the RVM was stimulated while recording dorsal horn neuronal activity in vivo under isoflurane anaesthesia at postnatal day (P) 21 and P40 (adult). Electrical thresholds for A and C fibre evoked activity, spike counts and wind‐up characteristics at baseline and during RVM stimulation (10–100 µA, 10 Hz) were compared. In adults, RVM stimulation selectively increased the threshold for C fibre evoked activity while at P21, it selectively decreased the threshold for A fibre evoked activity and these effects were correlated to the wind‐up characteristics of the neuron. Thus, the postnatal shift in RVM control of dorsal horn circuits is not only directional but also modality specific, from facilitation of A fibre input in the young animal to inhibition of nociceptive C input in the adult, with additional contextual factors. The descending control of spinal sensory networks serves very different functions in young and adult animals.
RGS4 regulates partial agonism of the M2 muscarinic receptor‐activated K+ currents
Authors: Chen I‐Shan , Furutani Kazuharu , Inanobe Atsushi , Kurachi Yoshihisa
Published: January 2014

Key points

Partial agonists produce a smaller response than full agonists even at 100% receptor occupancy.

In G‐protein‐coupled receptor signalling, the submaximal efficacy of partial agonists is determined by the conformational change of the agonist–receptor complex, which reduces effector activation. However, it remains unclear whether the regulator of G‐protein signalling (RGS) proteins contribute to the partial agonism.

By analysing the M2 muscarinic receptor (M2R)‐activated G‐protein‐gated K+ inwardly rectifying (KG) currents in a Xenopus oocyte expression system, pilocarpine acted as a partial agonist in the presence of RGS4, as it did in rat atrial myocytes, while it acted like the full agonist ACh in the absence of RGS4.

Functional couplings within the agonist–M2R complex/G‐protein/RGS4 system controlled the relative efficacy of the agonists.

Our findings help us to understand the molecular components and mechanism underlying the partial agonism of M2R‐mediated physiological responses.

Partial agonists are used clinically to avoid overstimulation of receptor‐mediated signalling, as they produce a submaximal response even at 100% receptor occupancy. The submaximal efficacy of partial agonists is due to conformational change of the agonist–receptor complex, which reduces effector activation. In addition to signalling activators, several regulators help control intracellular signal transductions. However, it remains unclear whether these signalling regulators contribute to partial agonism. Here we show that regulator of G‐protein signalling (RGS) 4 is a determinant for partial agonism of the M2 muscarinic receptor (M2R). In rat atrial myocytes, pilocarpine evoked smaller G‐protein‐gated K+ inwardly rectifying (KG) currents than those evoked by ACh. In a Xenopus oocyte expression system, pilocarpine acted as a partial agonist in the presence of RGS4 as it did in atrial myocytes, while it acted like a full agonist in the absence of RGS4. Functional couplings within the agonist–receptor complex/G‐protein/RGS4 system controlled the efficacy of pilocarpine relative to ACh. The pilocarpine–M2R complex suppressed G‐protein‐mediated activation of KG currents via RGS4. Our results demonstrate that partial agonism of M2R is regulated by the RGS4‐mediated inhibition of G‐protein signalling. This finding helps us to understand the molecular components and mechanism underlying the partial agonism of M2R‐mediated physiological responses.
Group velocity of cylindrical guided waves in anisotropic laminate composites
Authors: Glushkov Evgeny , Glushkova Natalia , Eremin Artem , Lammering Rolf
Published: January 2014

An explicit expression for the group velocity of wave packets, propagating in a laminate anisotropic composite plate in prescribed directions, is proposed. It is based on the cylindrical guided wave asymptotics derived from the path integral representation for wave fields generated in the composites by given localized sources. The expression derived is theoretically confirmed by the comparison with a known representation for the group velocity vector of a plane guided wave. Then it is experimentally validated against laser vibrometer measurements of guided wave packets generated by a piezoelectric wafer active sensor in a composite plate.
Spatial sound field synthesis and upmixing based on the equivalent source method
Authors: Bai Mingsian R. , Hsu Hoshen , Wen Jheng-Ciang
Published: January 2014

Given scarce number of recorded signals, spatial sound field synthesis with an extended sweet spot is a challenging problem in acoustic array signal processing. To address the problem, a synthesis and upmixing approach inspired by the equivalent source method (ESM) is proposed. The synthesis procedure is based on the pressure signals recorded by a microphone array and requires no source model. The array geometry can also be arbitrary. Four upmixing strategies are adopted to enhance the resolution of the reproduced sound field when there are more channels of loudspeakers than the microphones. Multi-channel inverse filtering with regularization is exploited to deal with the ill-posedness in the reconstruction process. The distance between the microphone and loudspeaker arrays is optimized to achieve the best synthesis quality. To validate the proposed system, numerical simulations and subjective listening experiments are performed. The results demonstrated that all upmixing methods improved the quality of reproduced target sound field over the original reproduction. In particular, the underdetermined ESM interpolation method yielded the best spatial sound field synthesis in terms of the reproduction error, timbral quality, and spatial quality.
Three-dimensional localization of transient acoustic sources using an ice-mounted geophone
Authors: Dosso Stan E.
Published: January 2014

This paper presents an approach to three-dimensional (3D) localization of ocean acoustic sources using a single three-component geophone on Arctic sea ice. Source bearing is estimated by maximizing the radial signal power as a function of horizontal look angle, applying seismic polarization filters to suppress shear waves with transverse particle motion. The inherent 180° ambiguity is resolved by requiring outgoing (prograde) particle motion in the radial-vertical plane. Source range and depth estimates and uncertainties are computed by Bayesian inversion of arrival-time differences of the water-borne acoustic wave and ice seismic waves, including the horizontally-polarized shear wave and longitudinal plate wave. The 3D localization is applied to geophone recordings of impulsive sources deployed in the water column at a series of ranges (200 to 1000 m) and bearings (0° to 90°) for three sites in the Lincoln Sea characterized by smooth annual ice, rough/ridged annual ice, and thick multi-year ice. Good bearing estimates are obtained in all cases. Range-depth localization is successful for ranges over which ice seismic arrivals could be reliably detected, approximately 200 m on rough ice, 500 m on smooth ice, and 800 m on multi-year ice. Effects of environmental uncertainty on localization are quantified by marginalizing over unknown environmental parameters.
Frequency-domain model of tonal blade thickness and loading noise
Authors: Mao Yijun , Xu Chen , Qi Datong
Published: January 2014

A tonal thickness noise and loading noise model of rotating blades has been developed as an extension of the exact frequency-domain solutions for rotating monopole and dipole point sources. The present model has two advantages over the previous methods and models for noise prediction. The first is the unified expression for sources in subsonic and supersonic rotation even at rest. The second is that the present model has no limit on the location of the observer and no interpolation error. Two test cases are carried out to validate the present model and emphasize its advantage at the noise prediction for sources in supersonic rotation. Moreover, as a specified application of the present model for the rotating blades whose tip radius is acoustically compact, acoustic energy distribution at different frequencies and in different directions is analyzed. Result shows that the acoustic energy of acoustically compact rotating blades is mainly concentrated at the source frequency while propagating along the axial direction, leaving the rest propagating along the radial direction at the other frequencies.
Heuristic approximations for sound fields produced by spherical waves incident on locally and non-locally reacting planar surfaces
Authors: Li Kai Ming , Tao Hongdan
Published: January 2014

The classic Weyl–van der Pol (WVDP) formula is a well-known asymptotic solution for accurately predicting sound fields above a locally reacting ground surface. However, the form of the WVDP formula is inadequate for predicting sound fields in the vicinity of non-locally reacting surfaces; a correction term is often required in the formula to provide accurate numerical solutions. Even with this correction, there is a singularity in the diffraction wave term when the source is located directly above or below the receiver. This paper explores a heuristic method to remove this singularity and suggests an analytical form comparable to the WVDP formula. This improved formula offers a physically interpretable solution and allows for accurate predictions of the total sound field above locally and non-locally reacting surfaces for all geometrical configurations.
Relationships between preference ratings, sensory profiles, and acoustical measurements in concert halls
Authors: Kuusinen Antti , Pätynen Jukka , Tervo Sakari , Lokki Tapio
Published: January 2014

Preferences of concert hall acoustics are explored with preference mapping. The investigation is performed on previously gathered data from individual vocabulary profiling of nine concert halls and three pieces of symphonic music, namely, excerpts of compositions by Beethoven, Bruckner, and Mozart. Individual preferences are regressed onto a latent three-dimensional sensory space obtained by multiple factor analysis of descriptive sensory data. Overlaying individually estimated preference surfaces onto one another produces preference maps which illustrates both the overall preference of the stimuli as well as differences between individual listeners. A comparison of the maps between music motifs illustrates how each music signal affects the weighting of different acoustical qualities in preference judgments. Differences in preferences between individuals are pronounced in the excerpts of Beethoven and Bruckner, while the responses are more homogeneous for Mozart music motif. Overall, proximity is identified as the main aspect associated with preference, but also loudness, envelopment, and bass are important. A correlation analysis of objective parameters and subjective perceptions substantiates the importance of lateral sound energy for good concert hall acoustics. Particularly, the lateral early energy fraction at high frequencies is found to be associated with the perception of proximity, and hence, also with preference.
Effect of situational, attitudinal and demographic factors on railway vibration annoyance in residential areas
Authors: Peris Eulalia , Woodcock James , Sica Gennaro , Sharp Calum , Moorhouse Andrew T. , Waddington David C.
Published: January 2014

Railway induced vibration is an important source of annoyance among residents living in the vicinity of railways. Annoyance increases with vibration magnitude. However, these correlations between the degree of annoyance and vibration exposure are weak. This suggests that railway vibration induced annoyance is governed by more than just vibration level and therefore other factors may provide information to understand the wide variation in annoyance reactions. Factors coming into play when considering an exposure-response relationship between level of railway vibration and annoyance are presented. The factors investigated were: attitudinal, situational and demographic factors. This was achieved using data from field studies comprised of face-to-face interviews and internal vibration measurements (N = 755). It was found that annoyance scores were strongly influenced by two attitudinal factors: Concern of property damage and expectations about future levels of vibration. Type of residential area and age of the respondent were found to have an important effect on annoyance whereas visibility of the railway and time spent at home showed a significant but small influence. These results indicate that future railway vibration policies and regulations focusing on community impact need to consider additional factors for an optimal assessment of railway effects on residential environments.
Two-dimensional vocal tracts with three-dimensional behavior in the numerical generation of vowels
Authors: Arnela Marc , Guasch Oriol
Published: January 2014

Two-dimensional (2D) numerical simulations of vocal tract acoustics may provide a good balance between the high quality of three-dimensional (3D) finite element approaches and the low computational cost of one-dimensional (1D) techniques. However, 2D models are usually generated by considering the 2D vocal tract as a midsagittal cut of a 3D version, i.e., using the same radius function, wall impedance, glottal flow, and radiation losses as in 3D, which leads to strong discrepancies in the resulting vocal tract transfer functions. In this work, a four step methodology is proposed to match the behavior of 2D simulations with that of 3D vocal tracts with circular cross-sections. First, the 2D vocal tract profile becomes modified to tune the formant locations. Second, the 2D wall impedance is adjusted to fit the formant bandwidths. Third, the 2D glottal flow gets scaled to recover 3D pressure levels. Fourth and last, the 2D radiation model is tuned to match the 3D model following an optimization process. The procedure is tested for vowels /a/, /i/, and /u/ and the obtained results are compared with those of a full 3D simulation, a conventional 2D approach, and a 1D chain matrix model.
Guided by the Dying
Authors: VanHook Annalisa M.
Published: January 2014

A tissue that is destined for destruction directs the formation of its replacement by redeploying an embryonic patterning program.
Statins Inhibit YAP
Authors: Berndt Jason D.
Published: January 2014

Statins limit breast cancer cell migration by inhibiting the transcriptional coactivator YAP.
Molecular Characterization of Multidrug-Resistant Mycobacterium tuberculosis Isolates from China
Authors: Zhao Li-Li , Chen Yan , Liu Hai-Can , Xia Qiang , Wu Xiao-Cui , Sun Qing , Zhao Xiu-Qin , Li Gui-Lian , Liu Zhi-Guang , Wan Kang-Lin
Published: January 2014

To investigate the molecular characterization of multidrug-resistant tuberculosis (MDR-TB) isolates from China and the association of specific mutations conferring drug resistance with strains of different genotypes, we performed spoligotyping and sequenced nine loci (katG,inhA, theoxyR-ahpCintergenic region,rpoB,tlyA,eis,rrs,gyrA, andgyrB) for 128 MDR-TB isolates. Our results showed that 108 isolates (84.4%) were Beijing family strains, 64 (59.3%) of which were identified as modern Beijing strains. Compared with the phenotypic data, the sensitivity and specificity of DNA sequencing were 89.1% and 100.0%, respectively, for isoniazid (INH) resistance, 93.8% and 100.0% for rifampin (RIF) resistance, 60.0% and 99.4% for capreomycin (CAP) resistance, 84.6% and 99.4% for kanamycin (KAN) resistance, and 90.0% and 100.0% for ofloxacin (OFX) resistance. The most prevalent mutations among the MDR-TB isolates werekatG315,inhA15,rpoB531, -526, and -516,rrs1401,eis-10, andgyrA94, -90, and -91. Furthermore, there was no association between specific resistance-conferring mutations and the strain genotype. These findings will be helpful for the establishment of rapid molecular diagnostic methods to be implemented in China.
Repression of Flagella Is a Common Trait in Field Isolates of Salmonella enterica Serovar Dublin and Is Associated with Invasive Human Infections
Authors: Yim Lucía , Sasías Sebastián , Martínez Arací , Betancor Laura , Estevez Verónica , Scavone Paola , Bielli Alejandro , Sirok Alfredo , Chabalgoity José Alejandro
Published: January 2014

The nontyphoidal
Salmonella enterica
serovar Dublin is adapted to cattle but infrequently infects humans, very often resulting in invasive infections with high levels of morbidity and mortality. A
Salmonella
-induced intestinal acute inflammatory response is postulated as a mechanism to prevent bacterial dissemination to systemic sites. In
S. enterica
serovar Typhimurium, flagella contribute to this response by providing motility and FliC-mediated activation of pattern recognition receptors. In this study, we found 4
Salmonella enterica
isolates, with the antigenic formula 9,12:−:−, that, based on
fliC
sequence and multilocus sequence type (MLST) analyses, are aflagellate
S
. Dublin isolates. Interestingly, all were obtained from human bloodstream infections. Thus, we investigated the potential role of flagella in the unusual invasiveness exhibited by
S
. Dublin in humans by analyzing flagellation and proinflammatory properties of a collection of 10
S
. Dublin human clinical isolates. We found that 4 of 7 blood isolates were aflagellate due to significantly reduced levels of
fliC
expression, whereas all 3 isolates from other sources were flagellated. Lack of flagella correlated with a reduced ability of triggering interleukin-8 (IL-8) and CCL20 chemokine expression in human intestinal Caco-2 cells and with reduced early inflammation in the ceca of streptomycin-pretreated C57/BL6 mice. These results indicate that flagella contribute to the host intestinal inflammatory response to
Salmonella
serovar Dublin and suggest that their absence may contribute to its systemic dissemination through dampening of the gut immune response. Analysis of FliC production in a collection of cattle isolates indicated that the aflagellate phenotype is widely distributed in field isolates of
S
. Dublin.
Potent Malaria Transmission-Blocking Antibody Responses Elicited by Plasmodium falciparum Pfs25 Expressed in Escherichia coli after Successful Protein Refolding
Authors: Kumar Rajesh , Angov Evelina , Kumar Nirbhay
Published: January 2014

Production of Pfs25, aPlasmodium falciparumtransmission-blocking vaccine target antigen, in functional conformation with the potential to elicit effective immunogenicity still remains a major challenge. In the current study, codon-harmonized recombinant Pfs25 (CHrPfs25) was expressed inEscherichia coli, and purified protein after simple oxidative refolding steps retained reduction-sensitive conformational epitopes of transmission-blocking monoclonal antibodies. CHrPfs25 formulated in several adjuvants elicited strong immunogenicity in preclinical studies in mice. Antibodies elicited after immunization recognized native Pfs25 on the surface of live gametes ofP. falciparumand demonstrated complete malaria transmission-blocking activity. The transmission-blocking efficacy was 100% even after a 1:128 dilution of sera from immunized mice in the complete Freund's adjuvant and Montanide ISA51 groups and after a 1:16 dilution of sera from mice in the alum group. The blocking was mediated by antibodies; purified IgG at concentrations as low as 31.25 μg/ml exhibited 100% transmission blocking in membrane feeding assays employing two different species of mosquitoes,Anopheles gambiaeandAnopheles stephensi. This study provides the first evidence for successful expression of biologically functional rPfs25 inE. coli. The extremely potent malaria transmission-blocking activity of antibodies elicited by immunization with purified protein provides strong support for further evaluation ofE. coli-derived CHrPfs25 as a malaria transmission-blocking vaccine in human clinical trials.
CD8+T Cells Eliminate Liver-Stage Plasmodium berghei Parasites without Detectable Bystander Effect
Authors: Cockburn Ian A. , Tse Sze-Wah , Zavala Fidel
Published: January 2014

Immunization with attenuatedPlasmodiumsporozoites or viral vectored vaccines can induce protective CD8+T cells that can find and eliminate liver-stage malaria parasites. A key question is whether CD8+T cells must recognize and eliminate each parasite in the liver or whether bystander killing can occur. To test this, we transferred antigen-specific effector CD8+T cells to mice that were then coinfected with twoPlasmodium bergheistrains, only one of which could be recognized directly by the transferred T cells. We found that the noncognate parasites developed normally in these mice, demonstrating that bystander killing of parasites does not occur during the CD8+T cell response to malaria parasites. Rather, elimination of infected parasites is likely mediated by direct recognition of infected hepatocytes by antigen-specific CD8+T cells.
Vibrational signatures of chemical- and density-induced structural changes in simulated amorphous silica
Authors: Grandy Victoria R. , Poduska Kristin M. , Saika-Voivod Ivan
Published: January 2014

Molecular dynamics simulations show that vibrational modes in glassy SiO2 are affected differently by density-induced changes to the structural order compared with those induced by specific cationic substitutions (Al, P, Na). Using standard measures of local and midrange positional order, we find that P disrupts network order in terms of second nearest neighbours, but preserves local order. In contrast, Al decreases local order while maintaining network order. Increased density preserves structural correlations in the network although the length scale shrinks. The complex short-range and long-range structural trends in these modified glasses coincide with changes in distinct regions in the vibrational density of states (VDOS). This suggests that a greater role for VDOS as a tool to link simulation and experiment in amorphous materials.
Mercury and marine birds in Arctic Canada: effects, current trends, and why we should be paying closer attention
Authors: Provencher J.F. , Mallory M.L. , Braune B.M. , Forbes M.R. , Gilchrist H.G.
Published: January 2014

Mercury (Hg) is a naturally occurring trace element that is also a by-product of anthropogenic activities and, in its methylated form, it is a neurotoxin that can have adverse effects on wildlife. The toxicity of Hg for humans, wildlife, and ecosystem health merits monitoring of its concentrations by various sampling means. Marine birds are widely used as indicators of ecosystem health, including biomonitoring of Hg in the Arctic. Since the mid-1970s, Hg concentrations in marine birds have been monitored across the Canadian North. Current Hg burdens in most northern marine bird species are below levels associated with health concerns, but several species have concentrations that are at or near levels associated with impaired reproduction. Arctic marine birds in Canada may be particularly at risk from increasing Hg levels associated with changing climatic conditions and long-term Hg deposition patterns. Research on marine birds should, therefore, continue to focus on spatial and temporal patterns of Hg contamination, assessing levels and biological effects in species that are experiencing high concentrations, and among species that are widely harvested due to the possible implications for human health.
SDC-CNTFET: STEPWISE DOPING CHANNEL DESIGN IN CARBON NANOTUBE FIELD EFFECT TRANSISTORS FOR IMPROVING SHORT CHANNEL EFFECTS IMMUNITY
Authors: JAMALABADI ZAHRA , KESHAVARZI PARVIZ , NADERI ALI
Published: January 2014

A novel carbon nanotube field-effect transistor with stepwise doping profile channel (SDC-CNTFET) is introduced for short-channel effects (SCEs) improvement. In SDC-CNTFET, the channel is divided into five sections of equal length. Impurity concentration was reduced from 0.8 nm-1 to zero from the source side to the drain side of the channel, with stepwise profile. The devices have been simulated by the self-consistent solution of two-dimensional (2D) Poisson–Schrödinger equations, within the nonequilibrium Green's function (NEGF) formalism. We demonstrate that the proposed structure for CNTFETs shows considerable improvement in device performance focusing on leakage current and ON–OFF current ratio. In addition, the investigation of SCEs for the proposed structure shows the improved drain-induced barrier lowering (DIBL) and subthreshold swing (SS). Moreover, we will prove that the proposed structure has acceptable performance at different values of channel impurity concentration in terms of delay and power-delay product (PDP). All these investigations introduce SDC-CNTFET as a more reliable device structure in short-channel regime.
IN QUEST OF A SYSTEMATIC FRAMEWORK FOR UNIFYING AND DEFINING NANOSCIENCE
Authors: TOMALIA DONALD A. , KHANNA SHIV N.
Published: January 2014

This is an invited overview of a lecture presented at the American Physical Society (APS) Meeting, Boston, USA (March 1, 2012). The primary focus of this APS lecture was to trace the historical emergence of Hard and Soft nanoscale superatoms (i.e. nano-element categories) as well as a recent merging of these concepts/entities by chemists/physicists into a unified system and framework for defining nanoscience. The convergence of these quantized, organic/inorganic superatom entities involved the application of traditional "first principles" and their nanoscale "atom mimicry" features as a criteria for evolving a roadmap of quantized nano-elemental categories, nano-compound/assemblies and nano-periodic patterns, etc., much as was observed in traditional chemistry. This simple perspective was used to define a nanoscale taxonomy of hard/soft superatom/nano-element categories, as well as to explain the dependency of a broad range of nano-periodic properties/features on one or more of six Critical Nanoscale Design Parameters (CNDPs) associated with these nano-building blocks, namely: (1) size, (2) shape, (3) surface chemistry, (4) rigidity/flexibility, (5) architecture and (6) elemental composition. Validation and support of this systematic nano-periodic perspective has appeared in many recent publications describing CNDP dependent nano-periodic property patterns/trends, rules and Mendeleev-like nano-periodic tables which may unify and provide first steps toward a "central paradigm" for nanoscience.
SINGLE-SOURCE DILATION-BOUNDED MINIMUM SPANNING TREES
Authors: CHEONG OTFRIED , LEE CHANGRYEOL
Published: January 2014

Given a set S of points in the plane, a geometric network for S is a graph G with vertex set S and straight edges. We consider a broadcasting situation, where one point r ∊ S is a designated source. Given a dilation factor δ, we ask for a geometric network G such that for every point v ∊ S there is a path from r to v in G of length at most δ|rv|, and such that the total edge length is minimized. We show that finding such a network of minimum total edge length is NP-hard, and give an approximation algorithm.
LOWER BOUND FOR CONVEX HULL AREA AND UNIVERSAL COVER PROBLEMS
Authors: KHANDHAWIT TIRASAN , PAGONAKIS DIMITRIOS , SRISWASDI SIRA
Published: January 2014

We provide a technique to obtain a lower bound for the area of the convex hull of a set of points and a rectangle in the plane, and then apply the resulting estimates to improve the lower bound for the convex case of Moser's Worm problem. Specifically, we show that any convex universal cover for unit arcs has an area of at least 0.232239. We also apply our approach to the universal cover problem for closed unit curves.
PROXIMITY DRAWINGS OF HIGH-DEGREE TREES
Authors: HURTADO FERRAN , LIOTTA GIUSEPPE , WOOD DAVID R.
Published: January 2014

A drawing of a given (abstract) tree that is a minimum spanning tree of the vertex set is considered aesthetically pleasing. However, such a drawing can only exist if the tree has maximum degree at most 6. What can be said for trees of higher degree? We approach this question by supposing that a partition or covering of the tree by subtrees of bounded degree is given. Then we show that if the partition or covering satisfies some natural properties, then there is a drawing of the entire tree such that each of the given subtrees is drawn as a minimum spanning tree of its vertex set.
MODELING THE ROLE OF MUTATIONS AND DENSITY INDEPENDENT DISPERSAL IN EVOLUTIONARY RESCUE
Authors: ORNIK MELKIOR
Published: January 2014

Faced with a strong and sudden deterioration of environment, a population encounters two possible options — adapt or perish. In general, it is not known which of those outcomes the environmental changes will lead to. Building on experimental research, we introduce a discrete-space, discrete-time model for environmental rescue based on the influence of population dispersal, as well as, potentially beneficial mutations. Numerical results obtained by the model are shown to correspond well to experimentally obtained data.
STUDY OF THE $\bar{K} N$ SYSTEM AND COUPLED CHANNELS IN A FINITE VOLUME
Authors: MARTÍNEZ TORRES A. , BAYAR M. , JIDO D. , OSET E.
Published: January 2014

We investigate the [Formula: see text] and coupled channels system in a finite volume and study the properties of the Λ(1405) resonance. We calculate the energy levels in a finite volume and solve the inverse problem of determining the resonance position in the infinite volume. We devise the best strategy of analysis to obtain the two poles of the Λ(1405) in the infinite volume case, with sufficient precision to distinguish them.
HIDDEN CHARM MOLECULES IN A FINITE VOLUME
Authors: ALBALADEJO M. , HIDALGO-DUQUE C. , NIEVES J. , OSET E.
Published: January 2014

In the present paper we address the interaction of charmed mesons in hidden charm channels in a finite box. We use the interaction from a recent model based on heavy quark spin symmetry that predicts molecules of hidden charm in the infinite volume. The energy levels in the box are generated within this model, and several methods for the analysis of these levels ("inverse problem") are investigated.
$\Sigma_c {\bar D}$ AND $\Lambda_c {\bar D}$ STATES IN A CHIRAL QUARK MODEL
Authors: WANG W. L. , HUANG F. , ZHANG Z. Y. , ZOU B. S.
Published: January 2014

We report our recent work on a dynamical investigation of the [Formula: see text] and [Formula: see text] states in a chiral quark model. Our results show that the [Formula: see text] interaction is attractive, which consequently results in a [Formula: see text] bound state with the binding energy of about 5-42 MeV, unlike the case of [Formula: see text] state, which has a repulsive interaction and thus is unbound.
STUDY OF INTERFERENCE EFFECTS ON THE Λ(1405) LINE SHAPE MEASURED BY HADES IN p+p COLLISIONS
Authors: FABBIETTI L.
Published: January 2014

In this work we investigate the possible interference effects between the Λ(1405) and the non-resonant final state in p+p reactions at 3.5 GeV beam kinetic energy measured by the HADES collaboration. The two poles nature of the Λ(1405), which is supported by most of the theoretical models, are parametrized within a simplified phenomenological model with Breit-Wigner functions to evaluate the interference effects. The model is adjusted such as to be in accordance with the theoretical prediction for the Λ(1405) in p+p collisions.
TRANSITION FORM FACTORS: A UNIQUE OPPORTUNITY TO CONNECT NON-PERTURBATIVE STRONG INTERACTIONS TO QCD
Authors:   (for the CLAS Collaboration), GOTHE RALF W.
Published: January 2014

Meson-photoproduction measurements and their reaction-amplitude analyses can establish more sensitively, and in some cases in an almost model-independent way, nucleon excitations and non-resonant reaction amplitudes. However, to investigate the strong interaction from explored — where meson-cloud degrees of freedom contribute substantially to the baryon structure — to still unexplored distance scales — where quark degrees of freedom dominate and the transition from dressed to current quarks occurs — we depend on experiments that allow us to measure observables that are probing this evolving non-perturbative QCD regime over its full range. Elastic and transition form factors are uniquely suited to trace this evolution by measuring elastic electron scattering and exclusive single-meson and double-pion electroproduction cross sections off the nucleon. These exclusive measurements will be extended to higher momentum transfers with the energy-upgraded CEBAF beam at JLab to study the quark degrees of freedom, where their strong interaction is responsible for the ground and excited nucleon state formations. After establishing unprecedented high-precision data, the imminent next challenge is a high-quality analysis to extract these relevant electrocoupling parameters for various resonances that then can be compared to state-of-the-art models and QCD-based calculations. Recent results will demonstrate the status of the analysis and of their theoretical descriptions, and an experimental and theoretical outlook will highlight what shall and may be achieved in the new era of the 12-GeV upgraded transition form factor program.