bluuebunny/crossref_metadata_2025 huggingface dataset:
Dose Efficiency of Quarter-Millimeter Photon-Counting Computed Tomography
Authors: Pourmorteza Amir , Symons Rolf , Henning André , Ulzheimer Stefan , Bluemke David A.
Published: March 2018

Purpose

The aim of this study was to assess the clinical feasibility, image quality, and radiation dose implications of 0.25-mm imaging mode in a cohort of humans, achieved by dividing the photon-counting detector (PCD) size in half compared with standard-resolution photon-counting computed tomography (CT) (0.5 mm).

Methods

In this technical feasibility study, a whole-body prototype PCD-CT scanner was studied in the 0.25 mm detector mode (measured at isocenter). A high-resolution PCD-CT protocol was first tested in phantom and canine studies in terms of image noise and spatial resolution. Then, 8 human subjects (mean age, 58 ± 8 years; 2 men) underwent axial PCD 0.25-mm scans of the brain, the thorax, and at the level of the upper left kidney. Filtered backprojection reconstruction was performed with a sharp kernel (B70) for standard-resolution and high-resolution data at 0.5-mm isotropic image voxel. High-resolution data, in addition, were reconstructed with an ultrasharp kernel (U70) at 0.25-mm isotropic voxels.

Results

Image reconstructions from the PCD 0.25-mm detector system led to an improvement in resolution from 9 to 18 line pairs/cm in a line pair phantom. Modulation transfer function improved from 9.5 to 15.8 line pairs/cm at 10% modulation transfer function. When fully exploiting this improvement, image noise increased by 75% compared with dose-matched 0.5-mm slice PCD standard-resolution acquisition. However, when comparing with standard-resolution data at same in-plane resolution and slice thickness, the PCD 0.25-mm detector mode showed 19% less image noise in phantom, animal, and human scans.

Conclusion

High-resolution photon-counting CT in humans showed improved image quality in terms of spatial resolution and image noise compared with standard-resolution photon-counting.
Treatment of Depression With Duloxetine in Mitochondrial Encephalopathy, Lactic Acidosis, and Stroke-Like Episodes
Authors: Cozart Brittany , Diaz Vera Jesus , Denham James D. , Whiting William L.
Published: March 2018

The mitochondrial cytopathies are a heterogeneous group of diseases characterized by heteroplasmic maternal transmission and selective dysfunction of tissues and organs highly dependent on aerobic respiration (eg, skeletal muscle, cardiac muscle, and brain). Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) is a specific subtype of mitochondrial cytopathy that is commonly associated with mood disturbances in individuals who survive until adulthood. Because of the altered cellular metabolism inherent in MELAS, it is often difficult to determine drug dosing, drug choice, and treatment response in patients with this rare disease. Historically, management of these patients focused on symptomatic relief and supplementation of compounds thought to optimize aerobic respiration (specifically, enzyme Co-Q10). We report a case in which an adult patient with MELAS and comorbid major depressive disorder demonstrated excellent response to the selective serotonin-norepinephrine reuptake inhibitor medication duloxetine.
Walter Kohn. 9 March 1923—19 April 2016
Authors: Hohenberg Pierre C. , Langer James S.
Published: March 2018

Walter Kohn, a giant of theoretical physics, died at his home in Santa Barbara, California, on 19 April 2016, at the age of 93. Walter's life epitomized both the hardships and the wondrous achievements of physicists in the twentieth century. He escaped from Nazi-occupied Austria on one of the last children's rescue trains (the
Kindertransport
) and during World War II spent 18 months confined in internment camps in England and Canada. He learned only after the War that both of his parents had perished in Auschwitz. After earning physics degrees at the University of Toronto and at Harvard University, he rapidly emerged as a leader in bringing quantum theory to bear on problems in the electron theory of solids. Walter's devotion to basic scientific principles led to the density functional theory of electrons in solids and in chemical molecules in the 1960s. Thirty years later, once the vast importance of this theory had become clear, he was awarded a Nobel Prize in Chemistry for this discovery. In his later years Walter turned much of his attention to institution building and public affairs. He was the founding director of the Institute for Theoretical Physics at the University of California, Santa Barbara. He was deeply committed to the control of nuclear weapons, the development of renewable clean energy and the free exchange of knowledge among scientists throughout the world.
Genetic defects in SAPK signalling, chromatin regulation, vesicle transport and CoA-related lipid metabolism are rescued by rapamycin in fission yeast
Authors: Sajiki Kenichi , Tahara Yuria , Villar-Briones Alejandro , Pluskal Tomáš , Teruya Takayuki , Mori Ayaka , Hatanaka Mitsuko , Ebe Masahiro , Nakamura Takahiro , Aoki Keita , Nakaseko Yukinobu , Yanagida Mitsuhiro
Published: March 2018

Rapamycin inhibits TOR (target of rapamycin) kinase, and is being used clinically to treat various diseases ranging from cancers to fibrodysplasia ossificans progressiva. To understand rapamycin mechanisms of action more comprehensively, 1014 temperature-sensitive (ts) fission yeast (
Schizosaccharomyces pombe
) mutants were screened in order to isolate strains in which the ts phenotype was rescued by rapamycin. Rapamycin-rescued 45 strains, among which 12 genes responsible for temperature sensitivity were identified. These genes are involved in stress-activated protein kinase (SAPK) signalling, chromatin regulation, vesicle transport, and CoA- and mevalonate-related lipid metabolism. Subsequent metabolome analyses revealed that rapamycin upregulated stress-responsive metabolites, while it downregulated purine biosynthesis intermediates and nucleotide derivatives. Rapamycin alleviated abnormalities in cell growth and cell division caused by
sty1
mutants (Δ
sty1
) of SAPK. Notably, in Δ
sty1
, rapamycin reduced greater than 75% of overproduced metabolites (greater than 2× WT), like purine biosynthesis intermediates and nucleotide derivatives, to WT levels. This suggests that these compounds may be the points at which the SAPK/TOR balance regulates continuous cell proliferation. Rapamycin might be therapeutically useful for specific defects of these gene functions.
Norm compliance affects perceptual decisions through modulation of a starting point bias
Authors: Toelch Ulf , Panizza Folco , Heekeren Hauke R.
Published: March 2018

Adaptive decisions in social contexts depend on both perceptual information and social expectations or norms. These are potentially in conflict when certain choices are beneficial for an individual, but societal rules mandate a different course of action. To resolve such a conflict, the reliability of information has to be balanced against potentially deleterious effects of non-compliance such as ostracism. In this study, we systematically investigated how interactions between perceptual and social influences affect decision-relevant cognitive processes. In a direction-of-motion discrimination task, participants received perceptual information alongside information on other players' choices. In addition, we created conflict scenarios where players’ choices affected other participants' monetary rewards dependent on whether their choices were in line or against the opinion of the other players. Importantly, we altered the strength of this manipulation in two separate experiments by contrasting motivations of either preventing harm or providing a benefit to others. Behavioural analyses and computational models of perceptual decisions showed that participants successfully integrated perceptual with social information. Participants' reliance on social information was effectively modulated in conflict situations. Critically, these effects were augmented when the strength of social norms was increased, indexing conditions under which social norms effectively influence decisions. These results inform theories of social influence by providing an account of how higher order goals like social norm compliance affect perceptual decisions.
Landslides and dam damage resulting from the Jiuzhaigou earthquake (8 August 2017), Sichuan, China
Authors: Zhao Bo , Wang Yun-sheng , Luo Yong-hong , Li Jia , Zhang Xin , Shen Tong
Published: March 2018

At 21.19 on 8 August 2017, an Ms 7.0 earthquake struck the Jiuzhaigou scenic spot in northwestern Sichuan Province, China. The Jiuzhaigou earthquake is a strike-slip earthquake with a focal depth of 20 km at 33.20° N and 103.82° E, and was caused by two concealed faults. According to emergency investigations and remote sensing interpretations, the Jiuzhaigou earthquake triggered 1780 landslides, damaged one dam (Nuorilang Waterfall) and broke one dam (Huohua Lake). The landslides mainly occurred in the Rize Valley and Shuzheng Valley and in Jiuzhai Paradise. The landslides involved hanging wall and back-slope effects, and the slope angle, slope aspect, seismic faults and valley trend were obviously related to the occurrence of the landslides. Specifically, most of the landslides were shallow landslides, rockfalls and rock avalanches and were small in scale. The failure modes of landslides mainly include wedge rock mass failure, residual deposit failure, relaxed rock mass failure and weathered rock mass failure. The initial low stability of the dam coupled with the topographic effect, back-slope effect and excess pore water pressure led to damage to the Nuorilang Waterfall dam.
Taphonomy ofIsisfordia duncanispecimens from the Lower Cretaceous (upper Albian) portion of the Winton Formation, Isisford, central-west Queensland
Authors: Syme Caitlin E. , Salisbury Steven W.
Published: March 2018

Taphonomic analysis of fossil material can benefit from including the results of actualistic decay experiments. This is crucial in determining the autochthony or allochthony of fossils of juvenile and adultIsisfordia duncani, a basal eusuchian from the Lower Cretaceous (upper Albian) distal-fluvial-deltaic lower Winton Formation near Isisford. The taphonomic characteristics of theI. duncanifossils were documented using a combination of traditional taphonomic analysis alongside already published actualistic decay data from juvenileCrocodylus porosuscarcasses. We found that theI. duncaniholotype, paratypes and referred specimens show little signs of weathering and no signs of abrasion. Disarticulated skeletal elements are often found in close proximity to the rest of the otherwise articulated skeleton. The isolated and disarticulated skeletal elements identified, commonly cranial, maxillary and mandibular elements, are typical of lag deposits. The holotype QM F36211 and paratype QM F34642 were classified as autochthonous, and the remainingI. duncaniparatypes and referred specimens are parautochthonous. We propose thatI. duncaniinhabited upper and lower delta plains near the Eromanga Sea in life. Their carcasses were buried in sediment-laden floodwaters in delta plain overbank and distributary channel deposits. Future studies should refer toI. duncanias a brackish water tolerant species.
Preparation of chitosan/MCM-41-PAA nanocomposites and the adsorption behaviour of Hg(II) ions
Authors: Fu Yong , Huang Yue , Hu Jianshe
Published: March 2018

A novel functional hybrid mesoporous composite material (CMP) based on chitosan and MCM-41-PAA was reported and its application as an excellent adsorbent for Hg(II) ions was also investigated. Innovatively, MCM-41-PAA was prepared by using diatomite and polyacrylic acid (PAA) with integrated polymer–silica hybrid frameworks, and then CMP was fabricated by introducing MCM-41-PAA to chitosan using glutaraldehyde as a cross-linking agent. The structure and morphology of CMP were characterized by X-ray diffraction, Fourier transform infrared spectra, thermogravimetric analysis, scanning electron microscopy and Brunauer–Emmett–Teller measurements. The results showed that the CMP possessed multifunctional groups such as –OH, –COOH and –NH
2
with large specific surface area. Adsorption behaviour of Hg(II) ions onto CMP was fitted better by the pseudo-second-order kinetic model and the Langmuir model when the initial Hg(II) concentration, pH, adsorption temperature and time were 200 mg l
−1
, 4, 298 K and 120 min, respectively, as the optimum conditions. The corresponding maximum adsorption capacity could reach 164 mg g
−1
. According to the thermodynamic parameters determined such as free energy, enthalpy and entropy, the adsorption process of Hg(II) ions was spontaneous endothermic adsorption.
Modelling cointegration and Granger causality network to detect long-term equilibrium and diffusion paths in the financial system
Authors: Gao Xiangyun , Huang Shupei , Sun Xiaoqi , Hao Xiaoqing , An Feng
Published: March 2018

Microscopic factors are the basis of macroscopic phenomena. We proposed a network analysis paradigm to study the macroscopic financial system from a microstructure perspective. We built the cointegration network model and the Granger causality network model based on econometrics and complex network theory and chose stock price time series of the real estate industry and its upstream and downstream industries as empirical sample data. Then, we analysed the cointegration network for understanding the steady long-term equilibrium relationships and analysed the Granger causality network for identifying the diffusion paths of the potential risks in the system. The results showed that the influence from a few key stocks can spread conveniently in the system. The cointegration network and Granger causality network are helpful to detect the diffusion path between the industries. We can also identify and intervene in the transmission medium to curb risk diffusion.
Trophic specialization drives morphological evolution in sea snakes
Authors: Sherratt Emma , Rasmussen Arne R. , Sanders Kate L.
Published: March 2018

Viviparous sea snakes are the most rapidly speciating reptiles known, yet the ecological factors underlying this radiation are poorly understood. Here, we reconstructed dated trees for 75% of sea snake species and quantified body shape (forebody relative to hindbody girth), maximum body length and trophic diversity to examine how dietary specialization has influenced morphological diversification in this rapid radiation. We show that sea snake body shape and size are strongly correlated with the proportion of burrowing prey in the diet. Specialist predators of burrowing eels have convergently evolved a ‘microcephalic’ morphotype with dramatically reduced forebody relative to hindbody girth and intermediate body length. By comparison, snakes that predominantly feed on burrowing gobies are generally short-bodied and small-headed, but there is no evidence of convergent evolution. The eel specialists also exhibit faster rates of size and shape evolution compared to all other sea snakes, including those that feed on gobies. Our results suggest that trophic specialization to particular burrowing prey (eels) has invoked strong selective pressures that manifest as predictable and rapid morphological changes. Further studies are needed to examine the genetic and developmental mechanisms underlying these dramatic morphological changes and assess their role in sea snake speciation.
Localization in semi-infinite herringbone waveguides
Authors: Haslinger S. G. , Jones I. S. , Movchan N. V. , Movchan A. B.
Published: March 2018

The paper includes novel results for the scattering and localization of a time-harmonic flexural wave by a semi-infinite herringbone waveguide of rigid pins embedded within an elastic Kirchhoff plate. The analytical model takes into account the orientation and spacing of the constituent parts of the herringbone system, and incorporates dipole approximations for the case of closely spaced pins. Illustrative examples are provided, together with the predictive theoretical analysis of the localized waveforms.
Nonlinear dynamics of a dispersive anisotropic Kuramoto–Sivashinsky equation in two space dimensions
Authors: Tomlin R. J. , Kalogirou A. , Papageorgiou D. T.
Published: March 2018

A Kuramoto–Sivashinsky equation in two space dimensions arising in thin film flows is considered on doubly periodic domains. In the absence of dispersive effects, this anisotropic equation admits chaotic solutions for sufficiently large length scales with fully two-dimensional profiles; the one-dimensional dynamics observed for thin domains are structurally unstable as the transverse length increases. We find that, independent of the domain size, the characteristic length scale of the profiles in the streamwise direction is about 10 space units, with that in the transverse direction being approximately three times larger. Numerical computations in the chaotic regime provide an estimate for the radius of the absorbing ball in

L

2

in terms of the length scales, from which we conclude that the system possesses a finite energy density. We show the property of equipartition of energy among the low Fourier modes, and report the disappearance of the inertial range when solution profiles are two-dimensional. Consideration of the high-frequency modes allows us to compute an estimate for the analytic extensibility of solutions in

C

2

. We also examine the addition of a physically derived third-order dispersion to the problem; this has a destabilizing effect, in the sense of reducing analyticity and increasing amplitude of solutions. However, sufficiently large dispersion may regularize the spatio-temporal chaos to travelling waves. We focus on dispersion where chaotic dynamics persist, and study its effect on the interfacial structures, absorbing ball and properties of the power spectrum.
DC dynamic pull-in instability of a dielectric elastomer balloon: an energy-based approach
Authors: Sharma Atul Kumar , Arora Nitesh , Joglekar M. M.
Published: March 2018

This paper reports an energy-based method for the dynamic pull-in instability analysis of a spherical dielectric elastomer (DE) balloon subjected to a quasi-statically applied inflation pressure and a Heaviside step voltage across the balloon wall. The proposed technique relies on establishing the energy balance at the point of maximum stretch in an oscillation cycle, followed by the imposition of an instability condition for extracting the threshold parameters. The material models of the Ogden family are employed for describing the hyperelasticity of the balloon. The accuracy of the critical dynamic pull-in parameters is established by examining the saddle-node bifurcation in the transient response of the balloon obtained by integrating numerically the equation of motion, derived using the Euler–Lagrange equation. The parametric study brings out the effect of inflation pressure on the onset of the pull-in instability in the DE balloon. A quantitative comparison between the static and dynamic pull-in parameters at four different levels of the inflation pressure is presented. The results indicate that the dynamic pull-in instability gets triggered at electric fields that are lower than those corresponding to the static instability. The results of the present investigation can find potential use in the design and development of the balloon actuators subjected to transient loading. The method developed is versatile and can be used in the dynamic instability analysis of other conservative systems of interest.
Social enforcement depending on the stage of colony growth in an ant
Authors: Shimoji Hiroyuki , Kikuchi Tomonori , Ohnishi Hitoshi , Kikuta Noritsugu , Tsuji Kazuki
Published: March 2018

Altruism is a paradox in Darwinian evolution. Policing is an important mechanism of the evolution and maintenance of altruism. A recently developed dynamic game model incorporating colony demography and inclusive fitness predicts that, in hymenopteran social insects, policing behaviour enforcing reproductive altruism in group members depends strongly on the colony growth stage, with strong policing as the colony develops and a relaxation of policing during the reproductive phase. Here, we report clear evidence supporting this prediction. In the antDiacammasp., reproduction by workers was suppressed by worker policing when the colony was small, whereas in large, mature colonies worker policing was relaxed and worker-produced males emerged. Conditional expression of traits can provide strong empirical evidence for natural selection theory if the expression pattern is precisely predicted by the theory, and our results illustrate the importance of intracolony population dynamics in the evolution of social systems.
Artificial light at night shifts daily activity patterns but not the internal clock in the great tit (
Parus major
)
Authors: Spoelstra Kamiel , Verhagen Irene , Meijer Davy , Visser Marcel E.
Published: March 2018

Artificial light at night has shown a dramatic increase over the last decades and continues to increase. Light at night can have strong effects on the behaviour and physiology of species, which includes changes in the daily timing of activity; a clear example is the advance in dawn song onset in songbirds by low levels of light at night. Although such effects are often referred to as changes in circadian timing, i.e. changes to the internal clock, two alternative mechanisms are possible. First, light at night can change the timing of clock controlled activity, without any change to the clock itself; e.g. by a change in the phase relation between the circadian clock and expression of activity. Second, changes in daily activity can be a direct response to light (‘masking’), without any involvement of the circadian system. Here, we studied whether the advance in onset of activity by dim light at night in great tits (
Parus major
) is indeed attributable to a phase shift of the internal clock. We entrained birds to a normal light/dark (LD) cycle with bright light during daytime and darkness at night, and to a comparable (LDim) schedule with dim light at night. The dim light at night strongly advanced the onset of activity of the birds. After at least six days in LD or LDim, we kept birds in constant darkness (DD) by leaving off all lights so birds would revert to their endogenous, circadian system controlled timing of activity. We found that the timing of onset in DD was not dependent on whether the birds were kept at LD or LDim before the measurement. Thus, the advance of activity under light at night is caused by a direct effect of light rather than a phase shift of the internal clock. This demonstrates that birds are capable of changing their daily activity to low levels of light at night directly, without the need to alter their internal clock.
To eat or not to eat: ontogeny of hypothalamic feeding controls and a role for leptin in modulating life-history transition in amphibian tadpoles
Authors: Bender Melissa Cui , Hu Caroline , Pelletier Chris , Denver Robert J.
Published: March 2018

Many animal life histories entail changing feeding ecology, but the molecular bases for these transitions are poorly understood. The amphibian tadpole is typically a growth and dispersal life-history stage. Tadpoles are primarily herbivorous, and they capitalize on growth opportunities to reach a minimum body size to initiate metamorphosis. During metamorphic climax, feeding declines, at which time the gastrointestinal (GI) tract remodels to accommodate the carnivorous diet of the adult frog. Here we show that anorexigenic hypothalamic feeding controls are absent in the tadpole, but develop during metamorphosis concurrent with the production of the satiety signal leptin. Before metamorphosis there is a large increase inleptinmRNA in fat tissue. Leptin receptor mRNA increased during metamorphosis in the preoptic area/hypothalamus, the key brain region involved with the control of food intake and metabolism. This corresponded with an increase in functional leptin receptor, as evidenced by induction ofsocs3mRNA and phosphorylated STAT3 immunoreactivity, and suppression of feeding behaviour after injection of recombinant frog leptin. Furthermore, we found that immunoneutralization of leptin in tadpoles at metamorphic climax caused them to resume feeding. The absence of negative regulation of food intake in the tadpole allows the animal to maximize growth prior to metamorphosis. Maturation of leptin-responsive neural circuits suppresses feeding during metamorphosis to facilitate remodelling of the GI tract.
Concede or clash? Solitary sharks competing for food assess rivals to decide
Authors: Brena Pierpaolo F. , Mourier Johann , Planes Serge , Clua Eric E.
Published: March 2018

To adapt to their environment, organisms can either directly interact with their surroundings or use social information (i.e. information provided by neighbouring individuals). Social information relates to the external features of surrounding peers, and little is known about its use by solitary species. Here, we investigated the use of social cues in a solitary marine predator by creating artificial aggregations of free-ranging sicklefin lemon sharks (
Negaprion acutidens
). Using a novel monitoring protocol, we analysed both dominance interactions and tolerance associations between sharks competing for food in relation with the number, the morphology and the behaviour of rivals. Sharks produced more agonistic displays and spent more time around the bait as competitors were more abundant. Moreover, the morphological attributes of competitors had very limited influence on the structure of shark social interactions. Instead, sharks appeared to establish tolerance relationships with competitors according to their individual behaviour. Furthermore, the more two sharks were observed together at a given study site, the fewer agonistic interactions they exchanged. We discuss these findings as evidence of the use of social cues in a non-gregarious predatory species and suggest directions for future research.
Specific adaptation to strong competitors can offset the negative effects of population size reductions
Authors: Zhao Xin-Feng , Buckling Angus , Zhang Quan-Guo , Hesse Elze
Published: March 2018

Competition plays a crucial role in determining adaptation of species, yet we know little as to how adaptation is affected by the strength of competition. On the one hand, strong competition typically results in population size reductions, which can hamper adaptation owing to a shortage of beneficial mutations; on the other hand, specificity of adaptation to competitors may offset the negative evolutionary consequences of such population size effects. Here, we investigate how competition strength affects population fitness in the bacterium
Pseudomonas fluorescens
. Our results demonstrate that strong competition constrains adaptation of focal populations, which can be partially explained by population size reductions. However, fitness assays also reveal specific adaptation of focal populations to particular competitors varying in competitive ability. Additionally, this specific adaptation can offset the negative effects of competitor-mediated population size reductions under strong competition. Our study, therefore, highlights the importance of opposing effects of strong competition on species adaptation, which may lead to different outcomes of colonization under intense and relaxed competitive environments in the context of population dispersal.
Indirect evolution of social fitness inequalities and facultative social exploitation
Authors: Nair Ramith R. , Fiegna Francesca , Velicer Gregory J.
Published: March 2018

Microbial genotypes with similarly high proficiency at a cooperative behaviour in genetically pure groups often exhibit fitness inequalities caused by social interaction in mixed groups. Winning competitors in this scenario have been referred to as ‘cheaters’ in some studies. Such interaction-specific fitness inequalities, as well as social exploitation (in which interaction between genotypes increases absolute fitness), might evolve due to selection for competitiveness at the focal behaviour or might arise non-adaptively due to pleiotropy, hitchhiking or genetic drift. The bacterium
Myxococcus xanthus
sporulates during cooperative development of multicellular fruiting bodies. Using
M. xanthus
lineages that underwent experimental evolution in allopatry without selection on sporulation, we demonstrate that interaction-specific fitness inequalities and facultative social exploitation during development readily evolved indirectly among descendant lineages. Fitness inequalities between evolved genotypes were not caused by divergence in developmental speed, as faster-developing strains were not over-represented among competition winners. In competitions between ancestors and several evolved strains, all evolved genotypes produced more spores than the ancestors, including losers of evolved-versus-evolved competitions, indicating that adaptation in non-developmental contexts pleiotropically increased competitiveness for spore production. Overall, our results suggest that fitness inequalities caused by social interaction during cooperative processes may often evolve non-adaptively in natural populations.
Does observability affect prosociality?
Authors: Bradley Alex , Lawrence Claire , Ferguson Eamonn
Published: March 2018

The observation of behaviour is a key theoretical parameter underlying a number of models of prosociality. However, the empirical findings showing the effect of observability on prosociality are mixed. In this meta-analysis, we explore the boundary conditions that may account for this variability, by exploring key theoretical and methodological moderators of this link. We identified 117 papers yielding 134 study level effects (totaln= 788 164) and found a small but statistically significant, positive association between observability and prosociality (r= 0.141, 95% confidence interval = 0.106, 0.175). Moderator analysis showed that observability produced stronger effects on prosociality: (i) in the presence of passive observers (i.e. people whose role was to only observe participants) versus perceptions of being watched, (ii) when participants’ decisions were consequential (versus non-consequential), (iii) when the studies were performed in the laboratory (as opposed to in the field/online), (iv) when the studies used repeated measures (instead of single games), and (v) when the studies involved social dilemmas (instead of bargaining games). These effects show the conditions under which observability effects on prosociality will be maximally observed. We describe the theoretical and practical significance of these results.
Do detour tasks provide accurate assays of inhibitory control?
Authors: van Horik Jayden O. , Langley Ellis J. G. , Whiteside Mark A. , Laker Philippa R. , Beardsworth Christine E. , Madden Joah R.
Published: March 2018

Transparent Cylinder and Barrier tasks are used to purportedly assess inhibitory control in a variety of animals. However, we suspect that performances on these detour tasks are influenced by non-cognitive traits, which may result in inaccurate assays of inhibitory control. We therefore reared pheasants under standardized conditions and presented each bird with two sets of similar tasks commonly used to measure inhibitory control. We recorded the number of times subjects incorrectly attempted to access a reward through transparent barriers, and their latencies to solve each task. Such measures are commonly used to infer the differential expression of inhibitory control. We found little evidence that their performances were consistent across the two different Putative Inhibitory Control Tasks (PICTs). Improvements in performance across trials showed that pheasants learned the affordances of each specific task. Critically, prior experience of transparent tasks, either Barrier or Cylinder, also improved subsequent inhibitory control performance on a novel task, suggesting that they also learned the general properties of transparent obstacles. Individual measures of persistence, assayed in a third task, were positively related to their frequency of incorrect attempts to solve the transparent inhibitory control tasks. Neophobia, Sex and Body Condition had no influence on individual performance. Contrary to previous studies of primates, pheasants with poor performance on PICTs had a wider dietary breadth assayed using a free-choice task. Our results demonstrate that in systems or taxa where prior experience and differences in development cannot be accounted for, individual differences in performance on commonly used detour-dependent PICTS may reveal more about an individual's prior experience of transparent objects, or their motivation to acquire food, than providing a reliable measure of their inhibitory control.
Genome-wide patterns of local adaptation inDrosophila melanogaster: adding intra European variability to the map
Authors: Mateo Lidia , Rech Gabriel E. , González Josefa
Published: March 2018

Signatures of spatially varying selection have been investigated both at the genomic and transcriptomic level in several organisms. InDrosophila melanogaster, the majority of these studies have analyzed North American and Australian populations, leading to the identification of several loci and traits under selection. However, populations in these two continents showed evidence of admixture that likely contributed to the observed population differentiation patterns. Thus, disentangling demography from selection is challenging when analyzing these populations. European populations could be a suitable system to identify loci under spatially varying selection provided that no recent admixture from African populations would have occurred. In this work, we individually sequence the genome of 42 European strains collected in populations from contrasting environments: Stockholm (Sweden), and Castellana Grotte, (Southern Italy). We found low levels of population structure and no evidence of recent African admixture in these two populations. We thus look for patterns of spatially varying selection affecting individual genes and gene sets. Besides single nucleotide polymorphisms, we also investigate the role of transposable elements in local adaptation. We concluded that European populations are a good dataset to identify loci under spatially varying selection. The analysis of the two populations sequenced in this work in the context of all the availableD. melanogasterdata allowed us to pinpoint genes and biological processes relevant for local adaptation. Identifying and analyzing populations with low levels of population structure and admixture should help to disentangle selective from non-selective forces underlying patterns of population differentiation in other species as well.
Tasman-PCR: A genetic diagnostic assay for Tasmanian devil facial tumour diseases
Authors: Kwon Young Mi , Stammnitz Maximilian R. , Wang Jinhong , Knowles Graeme W. , Pye Ruth J. , Hamede Rodrigo , Murchison Elizabeth P.
Published: March 2018

Tasmanian devils have spawned two transmissible cancer clones, known as devil facial tumour 1 (DFT1) and devil facial tumour 2 (DFT2). DFT1 and DFT2 are transmitted between animals by the transfer of allogeneic contagious cancer cells by biting, and both cause facial tumours. DFT1 and DFT2 tumours are grossly indistinguishable, but can be differentiated using histopathology, cytogenetics or genotyping of polymorphic markers. However, standard diagnostic methods require specialist skills and equipment and entail long processing times. Here, we describe Tasman-PCR: a simple PCR-based diagnostic assay that distinguishes DFT1 and DFT2 by amplification of DNA spanning tumour-specific interchromosomal translocations. We demonstrate the high sensitivity and specificity of this assay by testing DNA from 557 tumours and 818 normal devils. A temporal-spatial screen confirmed the reported geographic ranges of DFT1 and DFT2 and did not provide evidence of additional DFT clones. DFT2 affects disproportionately more males than females, and devils can be co-infected with DFT1 and DFT2. Overall, we present a PCR-based assay that delivers rapid, accurate and high-throughput diagnosis of DFT1 and DFT2. This tool provides an additional resource for devil disease management and may assist with ongoing conservation efforts.
A synthetic microbial consortium to detect and kill Vibrio cholerae
Authors: Cescato Margaux , Dumas Leila , Gerlin Leo , Grandjean Marie , Hebra Teo , Poulalier-Delavelle Margaux , Thibert Anna , Vivier Maxant , Zanoni Paul , Bordes Florence , Enjalbert Brice , Escudie Marie-Pierre , Faure Regis , Henras Anthony , Heux Stephanie , Louis Yoann , Millard Pierre , Montanier Cedric , Romeo Yves
Published: March 2018

Vibrio cholerae is nowadays still problematic in several countries which are exposed to recurrent disease outbreaks. The current disease detection and treatment methods are efficient so this approach focused on the prevention of the disease. Indeed, current solutions are not efficient enough to deal with this situation. As V. cholerae which infects more than a million people each year is usually found in water, a synthetic microbial consortium was designed to detect and kill efficiently the bacteria in water. This work shows that Vibrio harveyi, a non-pathogenic strain to human, can be an efficient detector of V. cholerae. Moreover, it proves that Pichia pastoris, a yeast, can efficiently produce a novel antimicrobial peptide coming from the crocodile Crocodylus siamensis (i.e D-NY15) and that this peptide has a killing action towards V. cholerae. This study also shows that a communication between a prokaryote (Vibrio harveyi) and an eukaryote (Pichia pastoris) may be possible.
An analysis of current state of the art software on nanopore metagenomic data
Authors: Pendleton Samantha C
Published: March 2018

Context

Our insight into DNA is controlled through a process called sequencing. Until recently, it was only possible to sequence DNA into short strings called “reads”. Nanopore is a new sequencing technology to produce significantly longer reads. Using nanopore sequencing, a single molecule of DNA can be sequenced without the need for time consuming PCR amplification (polymerase chain reaction is a technique used in molecular biology to amplify a single copy or a few copies of a segment of DNA across several orders of magnitude).

Aims

Metagenomics is the study of genetic material recovered from environmental samples. A research team from IBERS (Institute of Biological, Environmental & Rural Sciences) at Aberystwyth University have sampled metagenomes from a coal mine in South Wales using the Nanopore MinION and given initial taxonomic (classification of organisms) summaries of the contents of the microbial community.

Methods

Using various new software aimed for metagenomic data, we are interested to discover how well current bioinformatics software works with the data-set. We will conduct analysis and research into how well these new state of the art software works with this new long read data and try out some recent new developments for such analysis.

Results

Most of the software we used worked very well: we gained understanding of the ACGT count and quality of the data. However some software for bioinformatics don’t seem to work with nanopore data. Furthermore, we can conclude that low quality nanopore data may actually be quite average.
The changing landscape of VREfm in Victoria, Australia: a State-wide genomic snapshot
Authors: Lee Robyn S. , da Silva Anders Gonçalves , Baines Sarah L. , Strachan Janet , Ballard Susan , Carter Glen P. , Kwong Jason C. , Schultz Mark , Bulach Dieter , Seemann Torsten , Stinear Timothy P. , Howden Benjamin P.
Published: March 2018

Vancomycin-resistantEnterococcus faecium(VREfm) represent a major source of nosocomial infection worldwide. In Australia, thevanBgenotype is dominant; however there has been a recent increase in the predominantly plasmid-encodedvanAgenotype, prompting investigation into the genomic epidemiology of VREfm in this context.

Materials and Methods

A cross-sectional study of VREfm in Victoria, Australia (Nov.10th- Dec.9th, 2015). A total of 321 VREfm isolates (from 286 patients) were collected and whole-genome sequenced with Illumina NextSeq. Single nucleotide polymorphisms (SNPs) were used to assess relatedness. Multi-locus sequence types (STs), and genes associated with resistance and virulence were identified. ThevanA-harbouring plasmid from an isolate from each ST was assembled using long-read data.

Results

vanA-VREfm comprised 17.8% of isolates. ST203, ST80 and apstS(-) clade, ST1421, predominated (30.5%, 30.5% and 37.2% ofvanA-VREfm, respectively). MostvanB-VREfm were ST796 (77.7%).vanA-VREfm isolates were closely-related within hospitals vs. between them (core SNPs 10 [interquartile range 1-357] vs. 356 [179-416] respectively), suggesting discrete introductions ofvanA-VREfm, with subsequent intra-hospital transmission. In contrast,vanB-VREfm had similar core SNP distributions within vs. between hospitals, due to widespread dissemination of ST796. Overall,vanA-harbouring plasmids differed across STs, and with exception of ST78 and ST796, Tn1546transposons also varied.

Conclusions

vanA-VREfm in Victoria is associated with multiple STs, and is not solely mediated by a single shared plasmid/Tn1546transposon; clonal transmission appears to play an important role, predominantly within, rather than between, hospitals. In contrast,vanB-VREfm appears to be well-established and widespread across Victorian healthcare institutions.
Asymmetrically Positioned Flagellar Control Units Regulate Human Sperm Rotation
Authors: Miller Melissa R. , Kenny Samuel J , Mannowetz Nadja , Mansell Steven A. , Wojcik Michal , Mendoza Sarah , Zucker Robert S. , Xu Ke , Lishko Polina V.
Published: March 2018

The ability of sperm to fertilize an egg is controlled by ion channels, one of which is the pH-dependent calcium channel of sperm CatSper. For CatSper to be fully activated, the cytoplasmic pH must be alkaline, which is accomplished by either proton transporters, or a faster mechanism, such as the voltage-gated proton channel Hv1. To ensure effective regulation, these channels and regulatory proteins must be tightly compartmentalized. Here, we characterize human sperm nanodomains that are comprised of Hv1, CatSper and regulatory protein ABHD2. Super-resolution microscopy revealed that Hv1 forms asymmetrically positioned bilaterally distributed longitudinal lines that span the entire length of the sperm tail. Such a distribution provides a direct structural basis for the selective activation of CatSper, and subsequent flagellar rotation along the long axis that, together with hyperactivated motility, enhances sperm fertility. Indeed, Hv1 inhibition leads to a decrease in sperm rotation. Thus, sperm ion channels are organized in distinct regulatory nanodomains that control hyperactivated motility and rotation.
Characterizing Genetic Circuit Components in E. coli towards a Campylobacter jejuni Biosensor
Authors: Brzozowska Natalia , Gourlay Jane , O’Sullivan Ailish , Buchanan Frazer , Hannah Ross , Stewart Alison , Taylor Hannah , Docea Reuben , McLay Greig , Giuliano Ambra , Provan James , Baker Katherine , Abioye Jumai , Reboud Julien , Colloms Sean
Published: March 2018

Campylobacter jejuni is responsible for most cases of bacterial gastroenteritis (food poisoning) in the United Kingdom. The most common routes of transmission are by contact with raw poultry. Current detection systems for the pathogen are time-consuming, expensive or inaccessible for everyday users. In this article we propose a cheaper and faster system for detection of C. jejuni using a synthetic biology approach. We aimed to detect C. jejuni by the presence of xylulose, an uncommon bacterial capsular saccharide. We characterized two sugar-based regulatory systems that displayed potential to act as tools for detection of xylulose. Using a two-plasmid reporter system in Escherichia coli, we investigated the regulatory protein component (MtlR) of the mannitol operon from Pseudomonas fluorescens. Our findings suggest that the promoter of mtlE is activated by MtlR in the presence of a variety of sugar inducer molecules, and may exhibit cross-activity with a native regulator of E. coli. Additionally, we engineered the L-arabinose transcriptional activator (AraC) of E. coli for altered ligand specificity. We performed site-specific saturation mutagenesis to generate AraC variants with altered effector specificity, with an aim to generate a mutant activated by xylulose. We characterized several mutant AraC variants which have lost the ability to respond specifically to the native L-arabinose effector. We promote this technique as a powerful tool for future iGEM teams to create regulatory circuits activated by novel small molecule ligands.
Effect of visual cues in addition to moderate auditory cues on temporal coordination: A comparative study in humans and chimpanzees
Authors: Yu Lira , Tomonaga Masaki
Published: March 2018

Our previous studies reported that chimpanzees share an ability to produce spontaneous temporal coordination with humans (Yu & Tomonaga, 2015; 2016). However, it remains unclear how visual cues of an interacting partner’s movement influence on the emergence of tempo convergence. The current study conducted a comparative study in humans and chimpanzees under the same experimental setup as that used in Yu & Tomonaga (2016). Three conditions, including baseline, paired-invisible and paired-visible, were prepared. In the baseline condition, the participants produced the repetitive tapping movement alone. In contrast, in the other two paired conditions, the participants in a pair produced the tapping movement concurrently while facing a conspecific partner. However, in the paired-invisible condition, a visual barrier was placed in between the participants to control visual cues of an interacting partner’s movement. Moderate auditory cues, corresponding to each participant’s tapping movement, were presented throughout the conditions. Results showed that there are significant changes on the tapping tempo between baseline and the paired-invisible condition, whereas there are little changes between paired-invisible and paired-visible condition in both species. The current stepwise analysis across three conditions demonstrates that auditory cues were more influential than additive visual cues of an interacting partner’s movement on the tempo convergence in humans and chimpanzees.
The action of a cosmetic hair treatment on follicle function
Authors: Turner Graham A. , Paterson Sarah E. , Baines Fiona L. , Mayes Andrew E. , Reilly David M. , Hudson Nicole M. , Dadd Tony , Majumdar Amitabha , Kapoor Renu , Gu Jiayin , Bhalla Nitesh , Xu Fei
Published: March 2018

OBJECTIVE

Human hair changes with age: fibre diameter and density decrease, hair growth slows and shedding increases. This series of controlled studies examined the effect on hair growth parameters of a new leave-on hair treatment (LOT) formulated with DynagenTM(containing hydrolysed yeast protein) and zinc salts.

METHODS

Hair growth data were collected from healthy women aged 18–65 years. The LOT’s effect on hair growth was measured in a randomized double-blind study and in hair samples; its effect on follicle-cell proliferation was assessed by quantifying Ki67 expression in scalp biopsies. The LOT’s effect on plucking force was determined in anex vivomodel. Dynagen’s effect on the expression of the tight-junction marker claudin-1 was analysed in cultured follicles. The effect on protease activity of zinc salts used in the LOT was examinedin vitro.

RESULTS

Hair growth rate decreased with increasing subject age. The LOT significantly increased hair growth rate, fibre diameter, bundle cross-sectional area, Ki67 expression and the plucking force required to remove hair. Dynagen significantly increased claudin-1 expression in cultured follicles. Protease activity was reduced by zinc salts.

CONCLUSION

The Dynagen-based LOT increases hair-fibre diameter, strengthens the follicular root structure and increases hair growth rate.