bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis, microwave spectra, x-ray structure, and high-level theoretical calculations for formamidinium formate
Authors: Zhou Zunwu , Aitken R. Alan , Cardinaud Charlotte , Slawin Alexandra M. Z. , Wang Honghao , Daly Adam M. , Palmer Michael H. , Kukolich Stephen G.
Published: March 2019

An efficient synthesis of formamidinium formate is described. The experimental x-ray structure shows both internal and external H-bonding to surrounding molecules. However, in the gas phase, this compound occurs as a doubly hydrogen bonded dimer between formamidine and formic acid. This doubly hydrogen-bonded structure is quite different from the solid state structure. Microwave spectra were measured in the 6-14 GHz range using a pulsed-beam Fourier transform microwave (MW) spectrometer. The two nonequivalent N-atoms exhibit distinct quadrupole coupling. The rotational, centrifugal distortion, and quadrupole coupling constants determined from the spectra have the following values: A = 5880.05(2), B = 2148.7710(2), C = 1575.23473(13), 1.5 χaa (N1) = 1.715(3), 0.5(χbb–χcc) (N1) = −1.333(4), 1.5 χaa (N2) = 0.381(2), 0.25(χbb–χcc) (N2) = −0.0324(2), and DJ = 0.002145(5) MHz. The experimental inertial defect, Δ = −0.243 amu Å2, is consistent with a planar structure. Accurate and precise rotational constants (A, B, and C), obtained from the MW measurements, were closely reproduced, within 1%-2% of the measured values, with the M11 DFT theoretical calculations. Detailed comparison of the measured and calculated A, B, and C rotational constants confirms the planar doubly hydrogen bonded structure. The calculated nitrogen quadrupole coupling strengths of the monomer are quite different from either of the two nitrogen sites of the dimer. The poor agreement between measured and calculated quadrupole coupling strengths shows that the dimer is not locked in the equilibrium structure but is likely undergoing large amplitude vibrational motion of the hydrogen atoms moving between the N and O atoms involved in the hydrogen bonding.
Dynamical coring of Markov state models
Authors: Nagel Daniel , Weber Anna , Lickert Benjamin , Stock Gerhard
Published: March 2019

The accurate definition of suitable metastable conformational states is fundamental for the construction of a Markov state model describing biomolecular dynamics. Following the dimensionality reduction in a molecular dynamics trajectory, these microstates can be generated by a recently proposed density-based geometrical clustering algorithm [F. Sittel and G. Stock, J. Chem. Theory Comput. 12, 2426 (2016)], which by design cuts the resulting clusters at the energy barriers and allows for a data-based identification of all parameters. Nevertheless, projection artifacts due to the inevitable restriction to a low-dimensional space combined with insufficient sampling often leads to a misclassification of sampled points in the transition regions. This typically causes intrastate fluctuations to be mistaken as interstate transitions, which leads to artificially short life times of the metastable states. As a simple but effective remedy, dynamical coring requires that the trajectory spends a minimum time in the new state for the transition to be counted. Adopting molecular dynamics simulations of two well-established biomolecular systems (alanine dipeptide and villin headpiece), dynamical coring is shown to considerably improve the Markovianity of the resulting metastable states, which is demonstrated by Chapman-Kolmogorov tests and increased implied time scales of the Markov model. Providing high structural and temporal resolution, the combination of density-based clustering and dynamical coring is particularly suited to describe the complex structural dynamics of unfolded biomolecules.
Microscale wave breaking in stratified air-water pipe flow
Authors: Vollestad P. , Ayati A. A. , Jensen A.
Published: March 2019

We perform an experimental analysis of two-phase stratified wavy pipe flow, with the aim to detect and quantify the effect of small scale wave breaking. Particle image velocimetry is employed to analyze the velocity fields below individual waves, and a threshold for the vorticity on the leeward side of the crest is used to assess active wave breaking. Keeping the liquid flow rate constant, we analyze five experimental cases with increasing gas flow rates. The cases span the flow map from when first interfacial waves are observed, to the “amplitude saturation” regime, where the rms interface elevation is independent of the gas flow rate. While some wave breaking events are observed also in the wave-growth regime, wave breaking is found to be much more frequent when the gas flow rate is increased into the amplitude saturation regime, and 35%-40% of the waves passing the measurement section are assessed to be in a state of active breaking in this regime. A conditional averaging of the flow field is performed, and the turbulent dissipation rate below breaking and non-breaking waves is estimated. The effect of microscale breaking is observed down to a depth of 10 mm below the water surface. Below the crest of microscale breaking waves, the turbulent dissipation rate is increased by a factor 2.5 to 4 compared with non-breaking waves. This fraction increases with Usg, implying that the breaking events become more energetic as the gas flow rate is increased.
Understanding charge transport in Ir(ppy)3:CBP OLED films
Authors: Sanderson Stephen , Philippa Bronson , Vamvounis George , Burn Paul L. , White Ronald D.
Published: March 2019

Ir(ppy)3:CBP blends have been widely studied as the emissive layer in organic light emitting diodes (OLEDs), yet crucial questions about charge transport within the layer remain unaddressed. Recent molecular dynamics simulations show that the Ir(ppy)3 molecules are not isolated from each other, but at concentrations of as low as 5 wt. % can be part of connected pathways. Such connectivity raises the question of how the iridium(iii) complexes contribute to long-range charge transport in the blend. We implement a kinetic Monte Carlo transport model to probe the guest concentration dependence of charge mobility and show that distinct minima appear at approximately 10 wt. % Ir(ppy)3 due to an increased number of trap states that can include interconnected complexes within the blend film. The depth of the minima is shown to be dependent on the electric field and to vary between electrons and holes due to their different trapping depths arising from the different ionization potentials and electron affinities of the guest and host molecules. Typical guest-host OLEDs use a guest concentration below 10 wt. % to avoid triplet-triplet annihilation, so these results suggest that optimal device performance is achieved when there is significant charge trapping on the iridium(iii) complex guest molecules and minimum interactions of the emissive chromophores that can lead to triplet-triplet annihilation.
Bean’s critical-state model as a consequence of the circuit model of non-linear resistance
Authors: Lin Chungwei
Published: March 2019

Bean’s critical-state model has served as the foundation for computing the heat generated by the time-varying magnetic field or current in type-II superconductors. Two key features of the Bean model are (i) the current density is either zero or at the critical value Jc and (ii) the change in the current distribution begins at the surface. In this work, we apply the circuit model to simulate the process of charging a type-II superconductor. In addition to the self and mutual inductances among the basic units, we introduce a current-dependent longitudinal resistance to describe the critical current density, above which the conductor becomes resistive. By identifying the inductance values, we are able to reproduce the characteristic behavior of the Bean model. Specifically, we consider a superconducting slab and a superconducting wire composed of straight or twisted filaments and recover the established analytical results for these geometries. In terms of the circuit model, the behavior of the Bean model is a consequence of the geometry-specific structure of inductances and the non-linear resistances. Besides offering an intuitive explanation of the Bean model, our circuit-model calculations provide concrete examples to show that they can be used to simulate the complete charging process of multi-filament superconducting wires.
The ultrasensitive anomalous Hall effect induced by interfacial oxygen atoms redistribution
Authors: Peng W. L. , Zhang J. Y. , Luo L. S. , Feng G. N. , Yu G. H.
Published: March 2019

Improved weak magnetic field detection has been achieved by the ultrasensitive linear Anomalous Hall effect (AHE) in MgO/CoFeB/X/Ta/MgO (X: Hf or Gd) multilayers. The Anomalous Hall sensitivity (Sv) has been tuned by effective oxygen migration assisted interfacial oxygen atoms redistribution. For the sample with 0.2 nm Hf insertion, the Anomalous Hall sensitivity (Sv) is 16 182 Ω/T at the as-deposited state, 560% larger than that of the sample with no insertion (2470 Ω/T). However, the value of Sv for the sample with 0.2 nm Gd insertion is only up to 6837 Ω/T. An ultrahigh value of Sv (28 282 Ω/T) is obtained for the sample with 0.2 nm Hf insertion by a further annealing process. Interfacial structural results indicate that different linear AHE behavior originate from various interfacial oxygen atoms distribution states, which can be ascribed to different oxygen migration processes. The strong oxygen affinity capability of metallic Hf leads to the bidirectional interfacial oxygen migration. However, only unidirectional interfacial oxygen migration can be observed in the sample with 0.2 nm Gd insertion. This study will provide an effective way to improve the AHE-based sensors for weak magnetic field detection.
Role of angular bending freedom in regulating thermal transport in polymers
Authors: Subramanyan Harish , Zhang Weiye , He Jixiong , Kim Kyunghoon , Li Xiaobo , Liu Jun
Published: March 2019

Polymers, despite their desirable structural properties, suffer from low thermal conductivity, which restricts their use. Previous studies have indicated that the strong bond-stretching and angular-bending interactions along the chain are believed to have saturated the maximum achievable thermal conductivity in the along-the-chain direction. Contrary to this belief, our results show an improvement in thermal conductivity. By increasing the bond and angle potential, we studied the effect on the thermal conductivity of polyethylene using non-equilibrium molecular dynamics simulations. In comparison to restricting the bond stretching, we found that restricting angular bending freedom plays a crucial role in improving the thermal transport along the chain. We observed significant changes in the morphology of the polyethylene chains when the angle potential was increased. We also found a remarkable increase in the phonon group velocity accompanied by large shifts in the longitudinal acoustic branch of the dispersion curve. These results when coupled with the structural changes strongly support the argument that thermal conductivity can be controlled by restricting the angular bending freedom.
Literature as aesthetic knowledge: implications for curriculum and education
Authors: Cuthbert Alka Sehgal
Published: March 2019

This paper presents an argument for aesthetic knowledge in the arts and more specifically, for an aesthetic model of literature to be central in the curriculum. I argue that there are important distinctions to be made between the everyday experiences unique to us as individuals, and the universality of human experience. In the English Literature curriculum, this important difference is manifested in the status of the text because it is through a triadic engagement between educator, text and pupil that the meanings of experience can be evoked objectively. Through changing cultural and policy contexts in the post‐war period, the text has been marginalised in the curriculum. This has contributed to two detrimental effects. The first is that direct personal responses and experience have been overvalued in the English Literature curriculum. The second is that the idea of objective knowledge in literature has been misconstrued as knowledge of its linguistic substratum. Consequently, an important form of aesthetic knowledge is largely absent in Britain's secondary curriculum. The paper is organized into three sections. Section one describes main shifts in the cultural and policy contexts. Section two provides a brief empirical example of how shifts at the macro‐level have been re‐contextualised within the implied curriculum found in examples of national exams. Section three elucidates the deeper significance of these changes in light of a theoretical discussion of Kantian aesthetics and implications for a social realist approach to knowledge, curriculum and pedagogy derived from Durkheim.
Kinematic effects of repeated turns while running
Authors: Zago Matteo , Esposito Fabio , Bertozzi Filippo , Tritto Bruna , Rampichini Susanna , Galvani Christel , Galli Manuela , Sforza Chiarella
Published: March 2019

In team sports, non‐contact ACL and MCL injuries occur during abrupt changes of direction, like turns or cutting manoeuvres. Fatigue affects dynamic neuromuscular control and increases knee injury risk. This study analysed how lower limb joints and centre‐of‐mass kinematics are affected throughout a high‐intensity running protocol involving repeated 180°‐turns. Twenty young men (18–23 years, BMI: 20.8–24.4 kg m−2) completed a 5‐m shuttle running trial lasting 5 min at an average speed of 75% of their maximum aerobic speed. During the test, cardio‐metabolic parameters were obtained, together with joints and centre‐of‐mass kinematics, using a motion capture system. Kinematic data were compared between the first and the last minute of exercise. Perceived exercise intensity ranged from “hard” to “maximum exertion” and post‐exercise lactate concentration ranged from 5.4 to 15.5 mM. The repetition of 180°‐turns induced a substantial reduction of hip (−60%, p < .001, large effect) and knee flexion (−40%, p = .003, medium‐to‐large effect), and an increase of hip adduction and internal rotation (+25–30%, p < .05, medium‐to‐large effect). Since such movements are factors increasing the likelihood of non‐contact knee injuries, we concluded that the prolonged repetition of turns may expose participants to increased risk of ligament failure. Prevention programmes should include discipline‐specific neuromuscular training especially in late practices.
MACF1 links Rapsyn to microtubule- and actin-binding proteins to maintain neuromuscular synapses
Authors: Oury Julien , Liu Yun , Töpf Ana , Todorovic Slobodanka , Hoedt Esthelle , Preethish-Kumar Veeramani , Neubert Thomas A. , Lin Weichun , Lochmüller Hanns , Burden Steven J.
Published: March 2019

Complex mechanisms are required to form neuromuscular synapses, direct their subsequent maturation, and maintain the synapse throughout life. Transcriptional and post-translational pathways play important roles in synaptic differentiation and direct the accumulation of the neurotransmitter receptors, acetylcholine receptors (AChRs), to the postsynaptic membrane, ensuring for reliable synaptic transmission. Rapsyn, an intracellular peripheral membrane protein that binds AChRs, is essential for synaptic differentiation, but how Rapsyn acts is poorly understood. We screened for proteins that coisolate with AChRs in a Rapsyn-dependent manner and show that microtubule actin cross linking factor 1 (MACF1), a scaffolding protein with binding sites for microtubules (MT) and actin, is concentrated at neuromuscular synapses, where it binds Rapsyn and serves as a synaptic organizer for MT-associated proteins, EB1 and MAP1b, and the actin-associated protein, Vinculin. MACF1 plays an important role in maintaining synaptic differentiation and efficient synaptic transmission in mice, and variants in MACF1 are associated with congenital myasthenia in humans.
KAT8 selectively inhibits antiviral immunity by acetylating IRF3
Authors: Huai Wanwan , Liu Xingguang , Wang Chunmei , Zhang Yunkai , Chen Xi , Chen Xiang , Xu Sheng , Thomas Tim , Li Nan , Cao Xuetao
Published: March 2019

The transcription factor interferon regulatory factor 3 (IRF3) is essential for virus infection–triggered induction of type I interferons (IFN-I) and innate immune responses. IRF3 activity is tightly regulated by conventional posttranslational modifications (PTMs) such as phosphorylation and ubiquitination. Here, we identify an unconventional PTM of IRF3 that directly inhibits its transcriptional activity and attenuates antiviral immune response. We performed an RNA interference screen and found that lysine acetyltransferase 8 (KAT8), which is ubiquitously expressed in immune cells (particularly in macrophages), selectively inhibits RNA and DNA virus–triggered IFN-I production in macrophages and dendritic cells. KAT8 deficiency protects mice from viral challenge by enhancing IFN-I production. Mechanistically, KAT8 directly interacts with IRF3 and mediates IRF3 acetylation at lysine 359 via its MYST domain. KAT8 inhibits IRF3 recruitment to IFN-I gene promoters and decreases the transcriptional activity of IRF3. Our study reveals a critical role for KAT8 and IRF3 lysine acetylation in the suppression of antiviral innate immunity.
SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO
Authors: Nelson J. M. , Palmer Elizabeth T. , Wilkes B. G.
Published: March 2019

In Vol. 15, No. 5, May 20, 1932, in the equation at the foot of page 491, for log 100-p/p read log 100/100-p.
Free quandles and knot quandles are residually finite
Authors: Bardakov Valeriy , Singh Mahender , Singh Manpreet
Published: March 2019

In this note, residual finiteness of quandles is defined and investigated. It is proved that free quandles and knot quandles of tame knots are residually finite and Hopfian. Residual finiteness of quandles arising from residually finite groups (conjugation, core, and Alexander quandles) is established. Further, residual finiteness of automorphism groups of some residually finite quandles is also discussed.
Carleman approximation of maps into Oka manifolds
Authors: Chenoweth Brett
Published: March 2019

In this paper we obtain a Carleman approximation theorem for maps from Stein manifolds to Oka manifolds. More precisely, we show that under suitable complex analytic conditions on a totally real set

M
M

of a Stein manifold

X
X

, every smooth map

X
→
Y

X \rightarrow Y

to an Oka manifold

Y
Y

satisfying the Cauchy-Riemann equations along

M
M

up to order

k
k

can be

C

k

\mathscr {C}^k

-Carleman approximated by holomorphic maps

X
→
Y

X \rightarrow Y

. Moreover, if

K
K

is a compact

O

(
X
)

\mathscr {O}(X)

-convex set such that

K
∪
M

K \cup M

is

O

(
X
)

\mathscr {O}(X)

-convex, then we can

C

k

\mathscr {C}^k

-Carleman approximate maps which satisfy the Cauchy-Riemann equations up to order

k
k

along

M
M

and are holomorphic on a neighbourhood of

K
K

or merely in the interior of

K
K

if the latter set is the closure of a strongly pseudoconvex domain.
An ecological perspective on ‘plant carnivory beyond bogs’: nutritional benefits of prey capture for the Mediterranean carnivorous plant Drosophyllum lusitanicum
Authors: Skates Laura M , Paniw Maria , Cross Adam T , Ojeda Fernando , Dixon Kingsley W , Stevens Jason C , Gebauer Gerhard
Published: March 2019

Background and aims

Little is known about the evolutionary and ecological drivers of carnivory in plants, particularly for those terrestrial species that do not occur in typical swamp or bog habitats. The Mediterranean endemic Drosophyllum lusitanicum (Drosophyllaceae) is one of very few terrestrial carnivorous plant species outside of Australia to occur in seasonally dry, fire-prone habitats, and is thus an ecological rarity. Here we assess the nutritional benefits of prey capture for D. lusitanicum under differing levels of soil fertility in situ.

Methods

We measured the total nitrogen and stable nitrogen and carbon isotope ratios of D. lusitanicum leaves, neighbouring non-carnivorous plant leaves, and groups of insect prey in three populations in southern Spain. We calculated trophic enrichment (ε15N) and estimated the proportion of prey-derived nitrogen (%Nprey) in D. lusitanicum leaves, and related these factors to soil chemistry parameters measured at each site.

Key results

In all three populations studied, D. lusitanicum plants were significantly isotopically enriched compared with neighbouring non-carnivorous plants. We estimated that D. lusitanicum gain ~36 %Nprey at the Puerto de Gáliz site, ~54 %Nprey at the Sierra Carbonera site and ~75 %Nprey at the Montera del Torero site. Enrichment in N isotope (ε15N) differed considerably among sites; however, it was not found to be significantly related to log10(soil N), log10(soil P) or log10(soil K).

Conclusions

Drosophyllum lusitanicum individuals gain a significant nutritional benefit from captured prey in their natural habitat, exhibiting proportions of prey-derived nitrogen that are similar to those recorded for carnivorous plants occurring in more mesic environments. This study adds to the growing body of literature confirming that carnivory is a highly beneficial nutritional strategy not only in mesic habitats but also in seasonally dry environments, and provides insights to inform conservation strategies for D. lusitanicum in situ.
Time-to-event model-assisted designs for dose-finding trials with delayed toxicity
Authors: Lin Ruitao , Yuan Ying
Published: March 2019

Two useful strategies to speed up drug development are to increase the patient accrual rate and use novel adaptive designs. Unfortunately, these two strategies often conflict when the evaluation of the outcome cannot keep pace with the patient accrual rate and thus the interim data cannot be observed in time to make adaptive decisions. A similar logistic difficulty arises when the outcome is late-onset. Based on a novel formulation and approximation of the likelihood of the observed data, we propose a general methodology for model-assisted designs to handle toxicity data that are pending due to fast accrual or late-onset toxicity and facilitate seamless decision making in phase I dose-finding trials. The proposed time-to-event model-assisted designs consider each dose separately and the dose-escalation/de-escalation rules can be tabulated before the trial begins, which greatly simplifies trial conduct in practice compared to that under existing methods. We show that the proposed designs have desirable finite and large-sample properties and yield performance that is comparable to that of more complicated model-based designs. We provide user-friendly software for implementing the designs.
Active Monitoring and Feedback to Improve Blood Culture Fill Volumes and Positivity Across a Large Integrated Health System
Authors: Khare Reeti , Kothari Tarush , Castagnaro Joseph , Hemmings Bryan , Tso May , Juretschko Stefan
Published: March 2019

Background

The sensitivity of blood cultures increases with the volume of blood collected. However, hospitals face challenges in collecting adequate volume, and underfilled blood bottles are ubiquitous.

Methods

Blood bottle fill volumes were measured using an automated monitoring system across multiples sites (10 hospitals, 3 laboratories) within a large suburban/urban health system. Baseline fill volumes were measured for 4 months. A quality improvement program was then implemented over 36 months. Strategies to improve fill volumes included education, standardized data collection, novel and unblinded information cascades, targeted communication, and bottle markings for blood collectors.

Results

A total of 516 201 blood cultures were evaluated over 40 months. In the preimplementation period (January–April 2015), no hospitals collected the recommended 8–10 mL/bottle, and the average system fill volume was 2.3 mL. In the final postimplementation period (January–April 2018), 7 of 10 hospitals achieved ≥8 mL per bottle and the system average increased to 8.6 mL (P < .0001). The positivity rate increased 20%, from 7.39% to 8.85% (P < .001), whereas the contamination rate did not change and remained low. Compared to the preimplementation period, the odds of positive cultures containing potential pathogens increased to 1.18 (95% confidence interval, 1.05–1.32; P = .003).

Conclusions

Here we show that underfilled blood cultures are extremely common but that operational and educational strategies can result in sustained improvements across a complex network of hospitals and laboratories. This leads to increased detection of pathogens, which can have tremendous impact on the management of bloodstream infections and sepsis.
National Outbreak of Pertussis in England, 2011–2012: A Case-control Study Comparing 3-Component and 5-Component Acellular Vaccines With Whole-cell Pertussis Vaccines
Authors: Carvalho Carlos F A , Andrews Nick , Dabrera Gavin , Ribeiro Sonia , Stowe Julia , Ramsay Mary , Amirthalingam Gayatri
Published: March 2019

Background

In England, acellular pertussis (aP) vaccines replaced whole-cell pertussis (wP) vaccine in the primary immunization course in October 2004. Despite sustained high vaccine coverage, 10 454 cases were confirmed in England in 2011–2012, including 1648 (16%) in those aged 10–19 years. These individuals had been primed with either 3-component (aP3) or 5-component (aP5) aP vaccines or wP vaccine due to temporary supply shortages. We aimed to compare protection provided by different pertussis vaccines.

Methods

We conducted a case-control study. Individuals born between 1997 and 2005, fully vaccinated in England, were included. Cases were laboratory confirmed between January 2011 and December 2012. Controls were identified from population vaccination registers, representing 20% of the population. We compared the odds of receiving different types of vaccines in cases and controls, adjusting for year of birth and time since last vaccine received. Odds ratios (ORs) were calculated with 95% confidence intervals (CIs).

Results

We analyzed 403 cases and 581 971 controls with 4 pertussis vaccines recorded. Compared to those who received 3 doses of wP for the primary course, cases had higher odds of receiving 3 doses of aP3 (OR, 3.86 [95% CI, 2.56–5.82]) but no significant association with receipt of 3 doses of aP5 (OR, 0.89 [95% CI, .29–2.73]).

Conclusions

Previous studies have suggested that aP3 and aP5 vaccines provide shorter duration of protection than wP vaccine. Our findings suggest that a primary course with aP3 is associated with increased risk of confirmed pertussis compared with wP. Although follow-up was shorter for aP5 cohorts, their risk did not seem to differ from wP.
DoA-Based Event Localization Using Uniform Concentric Circular Array in the IoT Environment
Authors: Pandey Saurabh K , Zaveri Mukesh A
Published: March 2019

Response and recovery are the two most crucial aspects associated with post disaster management. Both these operations need real-time data and location at which the event occurs. These operations require event-based collection of data at critical times. The events may occur at any place and the data may be needed from either or all of the events for strategic planning and event handling. It is a challenging task to process the events whose locations are uncertain. In this view, there is a need to know the real-time location of events occurring in the surrounding. Moreover, there is a possibility of huge amount of signal processing among the devices deployed in the terrain. In this context, an event localization algorithm is proposed based on the Direction of Arrival estimation technique in the Internet of Things environment. It estimates the location of events by mapping the deployed devices using concentric circular array in the region. Further, the Cramer–Rao bound for the proposed algorithm is derived and compared with the existing schemes for efficacy. The algorithm is implemented on real test bed and presented with comparative evaluation to validate the work.
Imaging in patients with severe mitral annular calcification: insights from a multicentre experience using transatrial balloon-expandable valve replacement
Authors: Praz Fabien , Khalique Omar K , Lee Raymond , Wu Isaac Y , Russell Hyde , Guerrero Mayra , Wang Dee Dee , Veeragandham Ramesh , Islam Ashequl M , Deaton David W , Kaneko Tsuyoshi , Eudailey Kyle W , Akkoc Deniz , Kantor Alex , Wang Catherine , Tang Diane C H , Park Joongheum S , Leung Diana , Nazif Tamim M , Vahl Torsten P , Hahn Rebecca T , Kodali Susheel K , Leon Martin B , Takayama Hiroo , Bapat Vinayak , Borger Michael A , George Isaac
Published: March 2019

Aims

To investigate valve sizing and the haemodynamic relevance of the predicted left ventricular outflow tract (LVOT) in patients with mitral annular calcification (MAC) undergoing transatrial transcatheter valve implantation (THV).

Methods and results

In total, 21 patients undergoing transatrial THV, multiplanar reconstruction (MPR), maximum intensity projection (MIP), and cubic spline interpolation (CSI) were compared for MA sizing during diastole. In addition, predicted neo-LVOT areas were measured in 18 patients and correlated with the post-procedural haemodynamic dimensions. The procedure was successful in all patients (100%). Concomitant aortic valve replacement was performed in eight patients (43%) (AVR group). Sizing using MPR and MIP yielded comparable results in terms of area, perimeter, and diameter, whereas the dimensions obtained with CSI were systematically smaller. The simulated mean systolic neo-LVOT area was 133.4 ± 64.2 mm2 with an anticipated relative LVOT area reduction (neo-LVOT area/LVOT area × 100) of 59.3 ± 14.7%. The systolic relative LVOT area reduction, but not the absolute neo-LVOT area, was found to predict the peak (r = 0.69; P = 0.002) and mean (r = 0.65; P = 0.004) post-operative aortic gradient in the overall population as well as separately in the AVR (peak: r = 0.91; P = 0.002/mean: r = 0.85; P = 0.002) and no-AVR (peak: r = 0.89; P = 0.003/mean: r = 0.72; P = 0.008) groups.

Conclusion

In patients with severe MAC undergoing transatrial transcatheter valve implantation, MPR, and MIP yielded comparable annular dimensions, while values obtained with CSI tended to be systematically smaller. Mitral annular area and the average annular diameter appear to be reliable parameters for valve selection. Simulated relative LVOT reduction was found to predict the post-procedural aortic gradients.
My route to the intimacy of genomes
Authors: Dujon Bernard
Published: March 2019

Being invited by a prestigious journal to write the retrospective of one's life is first a great honor, and then a chore when starting to do it. These feelings did not spare me. But trying to recall my past to the best of my memory, I learned how lucky I was to have been born to a generation that witnessed so many scientific discoveries. There is little in common between the genetic courses I taught recently and those that I received more than 50 years ago. Thinking that a tiny bit of this fantastic evolution might come from my accidental encountering with yeasts is a stunning experience. I wish the same for the new generation.
Islamic Astronomy in Fifteenth-Century Christian Environments: Cardinal Bessarion and His Library
Authors: Bardi Alberto
Published: March 2019

This paper shows how Islamic astronomy played a significant role in the education of one of the most important Christian figures in the history of culture between eastern and western Europe, promoter of a crusade against the Ottoman Turks, namely Cardinal Bessarion (1400/1408–72). While the Byzantine polymath has generally been considered a purist of Ptolemaic astronomy, his interest in Islamic astronomy can be traced back to his youth and persisted throughout his life, as is testified by several sources from his manuscripts collection. It is misleading therefore to consider him a ‘purist’ of Ptolemy. The paper provides a survey of the texts of Islamic astronomy among the manuscripts of Bessarion’s estate. These are compared to Ptolemaic astronomy in order to assess the importance of Islamic astronomy within the framework of Bessarion’s collection. The results shed new light not only on Bessarion’s astronomical interests, but also on the reception of Islamic astronomy in non-Islamicate contexts in the fifteenth century, such as the late Byzantine Empire, Rhodes, Crete, Venice, and European humanism.
Effects of adjuvant radiation therapy on survival for patients with resected primary tracheal carcinoma: an analysis of the National Cancer Database
Authors: Yusuf Mehran , Gaskins Jeremy , Trawick Emma , Tennant Paul , Bumpous Jeffrey , van Berkel Victor , Fox Matthew , Dunlap Neal
Published: March 2019

Objective(s)

To identify predictors for receiving adjuvant radiation therapy (RT) and investigate the impact of adjuvant RT on survival for patients with resected primary tracheal carcinoma (PTC).

Methods

The National Cancer database was queried for patients with PTC diagnosed from 2004 to 2014 undergoing resection. Patients who died within 30 days of resection were excluded to minimize immortal time bias. Kaplan–Meier methods, Cox regression modeling and propensity score weighted (PSW) log-rank tests were considered to assess the relationship between adjuvant RT and overall survival (OS). Logistic regression was performed to identify predictors associated with receiving adjuvant RT.

Results

A total of 549 patients were identified with 300 patients (55%) receiving adjuvant RT. Squamous cell carcinoma (SCC) was the most common histology with 234 patients (43%). Adenoid cystic carcinoma (ACC) was second most frequent with 180 patients (33%). Adjuvant RT was not associated with OS by multivariable Cox analysis or PSW log-rank test (P values > 0.05). Patients with positive surgical margins (odds ratio (OR) 1.80, confidence interval (CI) 1.06–3.07) were more likely to receive adjuvant RT than those with negative surgical margins. Patients with ACC (OR 6.53, CI 3.57–11.95) were more likely to receive adjuvant RT compared with SCC.

Conclusions

Adjuvant RT was not significantly associated with OS for patients with resected PTC in this analysis. Surgical margin status and tumor histology were associated with receiving adjuvant RT. Further investigations including prospective registry studies capturing radiation technique and treatment volumes are needed to better define which patients with resected PTC may benefit from adjuvant RT.
Keck HIRES spectroscopy of SkyMapper commissioning survey candidate extremely metal-poor stars
Authors: Marino A F , Da Costa G S , Casey A R , Asplund M , Bessell M S , Frebel A , Keller S C , Lind K , Mackey A D , Murphy S J , Nordlander T , Norris J E , Schmidt B P , Yong D
Published: March 2019

We present results from the analysis of high-resolution spectra obtained with the Keck HIRES spectrograph for a sample of 17 candidate extremely metal-poor (EMP) stars originally selected from commissioning data obtained with the SkyMapper telescope. Fourteen of the stars have not been observed previously at high dispersion. Three have [Fe/H] ≤ −3.0, while the remainder, with two more metal-rich exceptions, have −3.0 ≤ [Fe/H] ≤ −2.0 dex. Apart from Fe, we also derive abundances for the elements C, N, Na, Mg, Al, Si, Ca, Sc, Ti, Cr, Mn, Co, Ni, and Zn, and for n-capture elements Sr, Ba, and Eu. None of the current sample of stars is found to be carbon-rich. In general, our chemical abundances follow previous trends found in the literature, although we note that two of the most metal-poor stars show very low [Ba/Fe] (∼−1.7) coupled with low [Sr/Ba] (∼−0.3). Such stars are relatively rare in the Galactic halo. One further star, and possibly two others, meet the criteria for classification as a r-I star. This study, together with that of Jacobson et al. (2015), completes the outcomes of the SkyMapper commissioning data survey for EMP stars.
Magnetized interstellar molecular clouds – II. The large-scale structure and dynamics of filamentary molecular clouds
Authors: Li Pak Shing , Klein Richard I
Published: March 2019

We perform ideal magnetohydrodynamics high-resolution adaptive mesh refinement simulations with driven turbulence and self-gravity and find that long filamentary molecular clouds are formed at the converging locations of large-scale turbulence flows and the filaments are bounded by gravity. The magnetic field helps shape and reinforce the long filamentary structures. The main filamentary cloud has a length of ∼4.4 pc. Instead of a monolithic cylindrical structure, the main cloud is shown to be a collection of fibre/web-like substructures similar to filamentary clouds such as L1495. Unless the line-of-sight is close to the mean field direction, the large-scale magnetic field and striations in the simulation are found roughly perpendicular to the long axis of the main cloud, similar to L1495. This provides strong support for a large-scale moderately strong magnetic field surrounding L1495. We find that the projection effect from observations can lead to incorrect interpretations of the true three-dimensional physical shape, size, and velocity structure of the clouds. Helical magnetic field structures found around filamentary clouds that are interpreted from Zeeman observations can be explained by a simple bending of the magnetic field that pierces through the cloud. We demonstrate that two dark clouds form a T-shaped configuration that is strikingly similar to the infrared dark cloud SDC13, leading to the interpretation that SDC13 results from a collision of two long filamentary clouds. We show that a moderately strong magnetic field (${{\cal M}_{\rm A}}\sim 1$) is crucial for maintaining a long and slender filamentary cloud for a long period of time ∼0.5 Myr.
A high binary fraction for the most massive close-in giant planets and brown dwarf desert members
Authors: Fontanive C , Rice K , Bonavita M , Lopez E , Mužić K , Biller B
Published: March 2019

Stellar multiplicity is believed to influence planetary formation and evolution, although the precise nature and extent of this role remain ambiguous. We present a study aimed at testing the role of stellar multiplicity in the formation and/or evolution of the most massive, close-in planetary and substellar companions. Using past and new direct imaging observations, as well as the Gaia DR2 catalogue, we searched for wide binary companions to 38 stars hosting massive giant planets or brown dwarfs (M > 7 MJup) on orbits shorter than ∼1 au. We report the discovery of a new component in the WASP-14 system, and present an independent confirmation of a comoving companion to WASP-18. From a robust Bayesian statistical analysis, we derived a binary fraction of $79.0^{+13.2}_{-14.7}$ per cent between 20 and 10 000 au for our sample, twice as high as for field stars with a 3σ significance. This binary frequency was found to be larger than for lower-mass planets on similar orbits, and we observed a marginally higher binary rate for inner companions with periods shorter than 10 d. These results demonstrate that stellar companions greatly influence the formation and/or evolution of these systems, suggesting that the role played by binary companions becomes more important for higher-mass planets, and that this trend may be enhanced for systems with tighter orbits. Our analysis also revealed a peak in binary separation at 250 au, highlighting a shortfall of close binaries among our sample. This indicates that the mechanisms affecting planet and brown dwarf formation or evolution in binaries must operate from wide separations, although we found that the Kozai–Lidov mechanism is unlikely to be the dominant underlying process. We conclude that binarity plays a crucial role in the existence of very massive short-period giant planets and brown dwarf desert inhabitants, which are almost exclusively observed in multiple systems.
Tobacco Cost of Illness Studies: A Systematic Review
Authors: Makate Marshall , Whetton Steve , Tait Robert J , Dey Tania , Scollo Michelle , Banks Emily , Norman Richard , Pidd Ken , Roche Ann M , Allsop Steven
Published: March 2019

Introduction

To identify studies reporting costs arising from tobacco use and detail their (1) economic approaches, (2) health outcomes, and (3) other cost areas included.

Methods

We searched PubMed, Scopus, Cochrane Library, EconLit, and Google Scholar for studies published between 2008 and April 2018 in English. Eligible articles reported tobacco-related costs and included all tobacco-using populations (multinational, national, subpopulations, and involuntary smokers). All economic approaches that resulted in monetary outcomes were included. We reported USD or converted local currencies to USD. Two health economists extracted and two researchers independently reviewed the data.

Results

From 4083 articles, we reviewed 361 abstracts and examined 79 full-texts, with 63 (1.6%) deemed eligible. There were three multinational, thirty-four national, twenty-one subpopulation or condition(s)-specific analyses, and five evaluating involuntary smoking. The diverse approaches and outcomes precluded integrating costs, but these were substantial in all studies. For instance, about USD 1436 billion in global health expenditures and productivity losses in 2012 and USD 9 billion in lost productivity in China, Brazil, and South Africa in 2012. At the national level, costs ranged from USD 4665 in annual per respondent health expenses (Germany 2006–2008) to USD 289–332.5 billion in medical expenses (United States 1964–2014).

Conclusions

Despite wide variations in the methods used, the identified costs of tobacco are substantial. Studies on tobacco cost-of-illness use diverse methods and hence produce data that are not readily comparable across populations, time, and studies, precluding a consistent evidence-base for action and measurement of progress. Recommendations are made to improve comparability.

Implications

In addition to the health and financial costs to individual smokers, smoking imposes costs on the broader community. Production of comparable estimates of the societal cost of tobacco use is impaired by a plethora of economic models and inconsistently included costs and conditions. These inconsistencies also cause difficulties in comparing relative impacts caused by differing factors. The review systematically documents the post-2007 literature on tobacco cost-of-illness estimations and details conditions and costs included. We hope this will encourage replication of models across settings to provide more consistent data, able to be integrated across populations, over time, and across risk factors.
Presenting Seneca in Print: Elizabethan Translations and Thomas Newton’s Seneca His Tenne Tragedies
Authors: Mayne Emily
Published: March 2019

Seneca His Tenne Tragedies (1581) was the first printed collection of Seneca’s tragedies in English. This article re-examines this publication in the context of early modern production of collected unannotated editions of Seneca’s tragedies on the European mainland, and of the editorial and intellectual interests of its compiler, Thomas Newton. It identifies Newton as something of an early modern ‘print professional’, who was involved in the production of a wide variety of texts, translations, and commendatory poetry, and who used a variety of sophisticated strategies in print to draw attention to and to promote his own capacities and achievements; and it shows how the Tenne Tragedies participates in these practices. Attending to Newton’s activities alongside Jasper Heywood’s translation of Hercules furens reveals significant discontinuities in approach between the Tenne Tragedies and one of its constituent texts. Heywood’s translation first appeared in 1561 in a parallel-text format that was not designed for inclusion in a single-language collection such as the Tenne Tragedies, as one early modern reader’s response to the translation in this later printed context may show. Newton’s presentation of the Tenne Tragedies volume, and his particular attitude towards ‘Seneca’, complicates current critical understanding of the reception and uses of Senecan tragedy in Elizabethan England, and of any ‘project’ of Senecan translation in the period, which may be more an effect of Newton’s editorial proclivities, combined with modern understanding of Seneca as a single author, than reflective of attitudes towards Senecan tragedy in early modern England more generally.
Infernovenator steenae, a new serpentine recumbirostran from the ‘Mazon Creek’ Lagerstätte further clarifies lysorophian origins
Authors: Mann Arjan , Pardo Jason D , Maddin Hillary C
Published: March 2019

The Carboniferous (Pennsylvanian; 309–307 Mya) ‘Mazon Creek’ Lagerstätte produces some of the earliest tetrapod fossils of major Palaeozoic lineages. Previously, the Mazon Creek record of lysorophians was known from a single poorly preserved specimen consisting only of a partial vertebral column. Here we describe a new, virtually complete lysorophian genus and species, Infernovenator steenae gen. & sp. nov. on the basis of a unique combination of characters, including a near complete circumorbital series and the retention of a postfrontal. Parsimony-based phylogenetic analysis placed the new taxon in the family Molgophidae, as sister to Brachydectes newberryi. Those results and the more generalized cranial morphology present in Infernovenator further support a recumbirostran origin of Molgophidae. Co-occurrence of two morphologically and functionally distinct molgophids in the Early Moscovian suggests a rapid and underappreciated diversification of this family in the Early Pennsylvanian.
‘Meiotic genes’ are constitutively expressed in an asexual amoeba and are not necessarily involved in sexual reproduction
Authors: Maciver Sutherland K. , Koutsogiannis Zisis , de Obeso Fernández del Valle Alvaro
Published: March 2019

The amoebae (and many other protists) have traditionally been considered as asexual organisms, but suspicion has been growing that these organisms are cryptically sexual or are at least related to sexual lineages. This contention is mainly based on genome studies in which the presence of ‘meiotic genes’ has been discovered. Using RNA-seq (next-generation shotgun sequencing, identifying and quantifying the RNA species in a sample), we have found that the entire repertoire of meiotic genes is expressed in exponentially growing
Acanthamoeba
and we argue that these so-called meiotic genes are involved in the related process of homologous recombination in this amoeba. We contend that they are only involved in meiosis in other organisms that indulge in sexual reproduction and that homologous recombination is important in asexual protists as a guard against the accumulation of mutations. We also suggest that asexual reproduction is the ancestral state.
Multi-rhythmicity generated by coupling two cellular rhythms
Authors: Yan Jie , Goldbeter Albert
Published: March 2019

The cell cycle and the circadian clock represent two major cellular rhythms, which are coupled because the circadian clock governs the synthesis of several proteins of the network that drives the mammalian cell cycle. Analysis of a detailed model for these coupled cellular rhythms previously showed that the cell cycle can be entrained at the circadian period of 24 h, or at a period of 48 h, depending on the autonomous period of the cell cycle and on the coupling strength. We show by means of numerical simulations that multiple stable periodic regimes, i.e. multi-rhythmicity, may originate from the coupling of the two cellular rhythms. In these conditions, the cell cycle can evolve to any one of two (birhythmicity) or three stable periodic regimes (trirhythmicity). When applied at the right phase, transient perturbations of appropriate duration and magnitude can induce the switch between the different oscillatory states. Such switching is characterized by final state sensitivity, which originates from the complex structure of the attraction basins. By providing a novel instance of multi-rhythmicity in a realistic model for the coupling of two major cellular rhythms, the results throw light on the conditions in which multiple stable periodic regimes may coexist in biological systems.