bluuebunny/crossref_metadata_2025 huggingface dataset:
The lowest Reynolds number of vortex-induced vibrations
Authors: Kou Jiaqing , Zhang Weiwei , Liu Yilang , Li Xintao
Published: April 2017

It is well known that the occurrence of vortex-induced vibration (VIV) at a subcritical Reynolds number, which is lower than 47, is induced by fluid-structure interaction. However, for the free flow, this phenomenon disappears at a Reynolds number about 20. The current study provides an explanation to the disappearance of the VIV by capturing the evolution of the purely fluid modes at Reynolds numbers between 12 and 55. To ensure accurate mode extraction, the dynamic mode decomposition technique is utilized. Results show that the stable von Kármán vortex shedding mode exists in a subcritical flow regime but becomes less distinct as the Reynolds number decreases. When the Reynolds number is lower than 18, this mode nearly vanishes, characterizing the lower boundary of fluid-structure instability.
Reduction of interface state density in SiC (0001) MOS structures by post-oxidation Ar annealing at high temperature
Authors: Kobayashi Takuma , Suda Jun , Kimoto Tsunenobu
Published: April 2017

We found that post-oxidation Ar annealing at high temperature is effective in reducing the interface state density (Dit) near the conduction band edge (EC) of SiC (0001) MOS structures. The Dit reduction effect is comparable to that of nitridation process (annealing in nitric oxide (NO)) which has been a standard in SiC MOS technologies, without introducing any foreign atoms into the interface/oxide. The generation of fast interface states, which have been pointed out as a problem of nitridation process, is suppressed in the case of Ar annealing. In the proposed method, the final Dit values are mainly determined by the Ar annealing temperature rather than the initial oxidation temperature. The Dit values are not sensitive to the cooling speed, which means that rapid cooling is not necessary in the proposed method.
Coherent radiation at the fundamental frequency by a Smith-Purcell free-electron laser with dielectric substrate
Authors: Li D. , Wang Y. , Nakajima M. , Tani M. , Hashida M. , Asakawa M. R. , Wei Y. , Miyamoto S.
Published: April 2017

This letter reports an approach to realize coherent radiation at the fundamental frequency of the wave that is resonant with the electron beam in a Smith-Purcell (SP) free-electron laser (FEL). We found that a two-dimensional grating structure equipped with a dielectric substrate could provide an electromagnetic mode which shows the property of a surface wave in the vacuum region where the beam-wave interaction occurs, and operates as a radiative wave in the dielectric region. Thus, an electron beam holding medium energy resonant with the mode could radiate at the fundamental frequency, which is different from the typical Smith-Purcell free-electron laser that radiates only at harmonics of the resonant frequency.
Surface functionalized carbon nanotube with polyvinylidene fluoride: Preparation, characterization, current-voltage and ferroelectric hysteresis behaviour of polymer nanocomposite films
Authors: Das Amit Kumar , Bhowmik Rabindranath , Meikap Ajit Kumar
Published: April 2017

A comparative study of current-voltage characteristics and ferroelectric properties of polyvinylidene fluoride (PVDF) based nanocomposite films with pure multiwall carbon nanotubes (MWCNTs) and surface functionalized MWCNTs by different type of functionalize groups (-COOH, -OH, -NH2) as filler, was reported. The flexible nanocomposite films based on PVDF and surface modified MWCNTs were fabricated via solution casting method. The current voltage characteristics suggests that –COOH and –OH functionalize MWCNT loading PVDF films are semiconducting in nature whereas raw MWCNT and –NH2 functionalize MWNCT loading PVDF films are comparatively conducting in nature. Experimental data of current density-electric field were fitted with different existing theoretical models. It is observed that just by changing the functionalization group the electrical conductivity of the composite films significantly changes which is discernible from the current-voltage characteristic. From ferroelectric study the energy density of –COOH, -OH loaded PVDF films are doubled and tripled compare to the pure PVDF film. This work may provide a rout for using different functionalize MWCNTs into polymer matrix to enhance either the energy density or conducting nature of polymer nanocomposite.
Complex permittivity analysis revisited: Microwave spectroscopy of organic semiconductors with resonant cavity
Authors: Choi Wookjin , Tsutsui Yusuke , Sakurai Tsuneaki , Seki Shu
Published: April 2017

The complex permittivity analysis of microwave dielectric loss spectroscopy has been revisited to deduce the intrinsic values of the mobility of charge carriers injected at the interface between an organic semiconductor and a gate insulator. A perturbation model with a simple parabolic function for frequency-dependent microwave resonance in the cavity enables us to experimentally determine the real and imaginary parts of the permittivity change caused by the injected charge carriers based on the Drude–Zener model, leading to the simultaneous assessment of the intrinsic charge-carrier mobility, the averaged trap depth/density, and the ratio of free-trapped charge carriers. The present frequency-dependent precise analysis of complex permittivity provides rapid and non-destructive screening of the total landscape of the charge-carrier transport at interfaces.
Role of surface and subsurface processes in scaling N2O emissions along riverine networks
Authors: Marzadri Alessandra , Dee Martha M. , Tonina Daniele , Bellin Alberto , Tank Jennifer L.
Published: April 2017

Significance

We show thatN2Oemissions from riverine systems depend on river and stream size and that the primary source ofN2Oproduction shifts from the hyporheic and benthic zones in streams to the benthic and water column in rivers. This analysis also reveals the primary scaling factors governing riverineN2Oemissions. Finally, it provides a predictive tool to quantifyN2Oemissions from any riverine environment worldwide, among biomes, land-use types, and climatic conditions, using readily available reach-scale biogeochemical measurements and hydromorphological data.
Oncogene KRAS activates fatty acid synthase, resulting in specific ERK and lipid signatures associated with lung adenocarcinoma
Authors: Gouw Arvin M. , Eberlin Livia S. , Margulis Katherine , Sullivan Delaney K. , Toal Georgia G. , Tong Ling , Zare Richard N. , Felsher Dean W.
Published: April 2017

Significance

We studied lung tumors induced by oncogene KRAS gene mutation using transgenic mice and human lung specimens. Gene expression analyses show that KRAS induces fatty acid synthase (FASN), promoting lipogenesis. Through desorption electrospray ionization MS imaging, we found specific lipid modifications in KRAS lung adenocarcinoma. Nanoimmunoassay identified specific KRAS-associated phosphoprotein signatures. We showed that KRAS activates the ERK2 protein, whereas non-KRAS lung adenocarcinoma shows elevated ERK1. We inhibited FASN by a small molecule, cerulenin, and this inhibition blocked cellular proliferation of KRAS-driven lung cancer cells. FASN inhibitors may, thus, present promising therapeutic agents for the treatment of KRAS-associated lung adenocarcinoma.
SAGA complex mediates the transcriptional up-regulation of antiviral RNA silencing
Authors: Andika Ida Bagus , Jamal Atif , Kondo Hideki , Suzuki Nobuhiro
Published: April 2017

Significance

RNAi-mediated antiviral defense is well conserved in eukaryotic organisms. Although several RNAi key genes are transcriptionally up-regulated upon virus infection in many hosts, little is known about their induction mechanism. Here, we developed a screening method for identification of the genes mediating robust transcriptional up-regulation upon infection by RNA viruses of the dicer-like 2 (
dcl2
) gene of an ascomycetous phytopathogen, chestnut blight fungus. We show that two enzymatic activities of histone acetyltransferase and histone deubiquitinase of the universally conserved SAGA (Spt–Ada–Gcn5 acetyltransferase) complex differentially regulate the transcriptional induction of two main antiviral RNA silencing components,
dcl2
and argonaute-like 2 (
agl2
). A virus-specific pattern requirement of AGL2 and DCL2 as positive feedback players for this transcriptional induction is also noted.
Malate-dependent Fe accumulation is a critical checkpoint in the root developmental response to low phosphate
Authors: Mora-Macías Javier , Ojeda-Rivera Jonathan Odilón , Gutiérrez-Alanís Dolores , Yong-Villalobos Lenin , Oropeza-Aburto Araceli , Raya-González Javier , Jiménez-Domínguez Gabriel , Chávez-Calvillo Gabriela , Rellán-Álvarez Rubén , Herrera-Estrella Luis
Published: April 2017

Significance

Phosphate (Pi) deficiency constrains plant development and productivity in both natural and agricultural ecosystems. An interaction among Pi and Fe availability controls the developmental program that allows the
Arabidopsis
root system to more effectively explore the topsoil where Pi accumulates. Analysis of mutants unable to establish root architecture responses to low Pi allowed the identification of mutant alleles of
STOP1
(a transcription factor) and
ALMT1
(a malate transporter), two genes previously reported to play a role in the malate-mediated tolerance to toxic levels of aluminum. We show that these genes underlie a malate-exudation–dependent mechanism of Fe relocation in the root apical meristem that is essential for reprogramming root growth under low-Pi conditions.
Aggregation landscapes of Huntingtin exon 1 protein fragments and the critical repeat length for the onset of Huntington’s disease
Authors: Chen Mingchen , Wolynes Peter G.
Published: April 2017

Significance

Formation of inclusion bodies is the pathological hallmark of Huntington’s disease. Huntingtin exon 1-encoded protein fragments aggregate in inclusion bodies, causing disease onset in a length-dependent manner. Using energy landscape theory, the critical length for disease onset is predicted to be between 30 and 40.
Time course of overt attentional shifts in mental arithmetic: Evidence from gaze metrics
Authors: Masson Nicolas , Letesson Clément , Pesenti Mauro
Published: April 2017

Processing numbers induces shifts of spatial attention in probe detection tasks, with small numbers orienting attention to the left and large numbers to the right side of space. This has been interpreted as supporting the concept of a mental number line with number magnitudes ranging from left to right, from small to large numbers. Recently, the investigation of this spatial-numerical link has been extended to mental arithmetic with the hypothesis that solving addition or subtraction problems might induce attentional displacements, rightward or leftward, respectively. At the neurofunctional level, the activations elicited by the solving of additions have been shown to resemble those induced by rightward eye movements. However, the possible behavioural counterpart of these activations has not yet been observed. Here, we investigated overt attentional shifts with a target detection task primed by addition and subtraction problems (2-digit ± 1-digit operands) in participants whose gaze orientation was recorded during the presentation of the problems and while calculating. No evidence of early overt attentional shifts was observed while participants were hearing the first operand, the operator or the second operand, but they shifted their gaze towards the right during the solving step of addition problems. These results show that gaze shifts related to arithmetic problem solving are elicited during the solving procedure and suggest that their functional role is to access, from the first operand, the representation of the result.
Atlantic Sturgeon Use of the Penobscot River and Marine Movements within and beyond the Gulf of Maine
Authors: Altenritter Megan N. , Zydlewski Gayle Barbin , Kinnison Michael T. , Wippelhauser Gail S.
Published: April 2017

Atlantic Sturgeon Acipenser oxyrinchus oxyrinchus were recently listed as threatened in the Gulf of Maine and endangered in the rest of their U.S. range. Continued research priorities include long-term population monitoring, identifying the species’ spawning and nursery grounds, and determining its use of estuaries and marine coastal waters. Although recent and ongoing research is filling in knowledge gaps, the Atlantic Sturgeon's life history and its severely depleted populations make this a challenging species to fully characterize. Our goal was to compile data collected over 7 years from fish captured in the Penobscot River estuary, Maine, to inform management decision making. Atlantic Sturgeon were captured (n = 199), recaptured (n = 16), and passively telemetered (n = 32 that were analyzed here) from 2006 to 2013. Captured individuals were predominantly subadults, and data from telemetry indicated repeated use of a 5-km reach of the mesohaline portion of the estuary. Subadults predictably emigrated from the river each fall (mean date ± SD, August 31 ± 43.5 d) and immigrated back each spring to early summer (May 15 ± 27.8 d), with most individuals (>95% [31 of 32]) returning one or more years after tagging. Marine detections of these subadults were common (81.25% [26 of 32]) and spanned the geographic extent of both the threatened and endangered U.S. distinct population segments and into international waters, e.g., from the Hudson River, New York, to Minas Basin, Nova Scotia. However, they were more typically detected by receivers in the Gulf of Maine; 77% (20 of 26) were only detected in the Gulf of Maine when not in the river. These data indicate that, based on the temporal and spatial predictability of habitat use, the estuary of the Penobscot River is important for subadult Atlantic Sturgeon of the Gulf of Maine. The wider movement patterns emphasize the need for conservation and management across regions and international boundaries.
Identification and Characterization of Nursery Areas of Red Mullet Mullus barbatus in the Central Tyrrhenian Sea
Authors: Criscoli Alessandro , Carpentieri Paolo , Colloca Francesco , Belluscio Andrea , Ardizzone Giandomenico
Published: April 2017

Red Mullet Mullus barbatus is an important target of fishing activities in the central Tyrrhenian Sea, so it is essential to identify its critical habitats in order to manage this resource efficiently. Our research specifically focused on the identification and characterization of nursery areas. The use of spatial interpolation techniques enabled us to identify five nurseries that were highly persistent through time. Moreover, the estimate of juvenile density confirmed the strong aggregation effect of these nursery grounds, as a great portion of young individuals were concentrated in a relatively small surface of the study area. The environmental characterization of these areas showed that juveniles were mainly distributed on bottoms with a relatively high percentage of sand (>70%; P < 0.05). Shannon biodiversity index analysis indicated that the southern nurseries reached the highest values of habitat quality (P < 0.0001). Multivariate analysis showed that nursery grounds were divided into three main groups, and analysis of spatial dynamics showed that two different strategies characterized Red Mullet juveniles when density changes over time. In particular, in some areas young individuals selected habitats in a density-dependent way following the basin model scheme, while in other zones they selected habitats in a density-independent way according to the proportional density model. Results also showed that juveniles followed the proportional density model strategy into nursery areas with the highest Shannon biodiversity index values.
Preprotein mature domains contain translocase targeting signals that are essential for secretion
Authors: Chatzi Katerina E. , Sardis Marios Frantzeskos , Tsirigotaki Alexandra , Koukaki Marina , Šoštarić Nikolina , Konijnenberg Albert , Sobott Frank , Kalodimos Charalampos G. , Karamanou Spyridoula , Economou Anastassios
Published: April 2017

Secretory proteins are only temporary cytoplasmic residents. They are typically synthesized as preproteins, carrying signal peptides N-terminally fused to their mature domains. In bacteria secretion largely occurs posttranslationally through the membrane-embedded SecA-SecYEG translocase. Upon crossing the plasma membrane, signal peptides are cleaved off and mature domains reach their destinations and fold. Targeting to the translocase is mediated by signal peptides. The role of mature domains in targeting and secretion is unclear. We now reveal that mature domains harbor their own independent targeting signals (mature domain targeting signals [MTSs]). These are multiple, degenerate, interchangeable, linear or 3D hydrophobic stretches that become available because of the unstructured states of targeting-competent preproteins. Their receptor site on the cytoplasmic face of the SecYEG-bound SecA is also of hydrophobic nature and is located adjacent to the signal peptide cleft. Both the preprotein MTSs and their receptor site on SecA are essential for protein secretion. Evidently, mature domains have their own previously unsuspected distinct roles in preprotein targeting and secretion.
Separable quotients in 𝐶_{𝑐}(𝑋), 𝐶_{𝑝}(𝑋), and their duals
Authors: Ka̧kol Jerzy , Saxon Stephen
Published: April 2017

The quotient problem has a positive solution for the weak and strong duals of

C

c

(
X
)

C_{c}\left ( X\right )

(

X
X

an infinite Tichonov space), for Banach spaces

C

c

(
X
)

C_{c}\left ( X\right )

, and even for barrelled

C

c

(
X
)

C_{c}\left ( X\right )

, but not for barrelled spaces in general. The solution is unknown for general

C

c

(
X
)

C_{c}\left ( X\right )

. A locally convex space is properly separable if it has a proper dense

ℵ

0

\aleph _{0}

-dimensional subspace. For

C

c

(
X
)

C_{c}\left ( X\right )

quotients, properly separable coincides with infinite-dimensional separable.

C

c

(
X
)

C_{c}\left ( X\right )

has a properly separable algebra quotient if

X
X

has a compact denumerable set. Relaxing compact to closed, we obtain the converse as well; likewise for

C

p

(
X
)

C_{p}\left ( X\right )

. And the weak dual of

C

p

(
X
)

C_{p}\left ( X\right )

, which always has an

ℵ

0

\aleph _{0}

-dimensional quotient, has no properly separable quotient when

X
X

is a P-space of a certain special form

X
=

X
κ

X=X_\kappa
Link diagrams with low Turaev genus
Authors: Kim Seungwon
Published: April 2017

We classify link diagrams with Turaev genus one and two in terms of an alternating tangle structure of the link diagram. The proof involves surgery along simple loops on the Turaev surface, called cutting loops, which have corresponding cutting arcs that are visible on the planar link diagram. These also provide new obstructions for a link diagram on a surface to come from the Turaev surface algorithm. We also show that inadequate Turaev genus one links are almost-alternating.
On the classification of prolongations up to Engel homotopy
Authors: del Pino Álvaro
Published: April 2017

In (Casals, Pérez, del Pino, and Presas, preprint) it was shown that Engel structures satisfy an existence

h
h

–principle, and the question of whether a full

h
h

–principle holds was left open. In this note we address the classification problem, up to Engel deformation, of Cartan and Lorentz prolongations. We show that it reduces to their formal data as soon as the turning number is large enough.

Somewhat separately, we study the homotopy type of the space of Cartan prolongations, describing completely its connected components in the overtwisted case.
Lefschetz classes on projective varieties
Authors: Huh June , Wang Botong
Published: April 2017

The Lefschetz algebra

L
∗

(
X
)

L^*(X)

of a smooth complex projective variety

X
X

is the subalgebra of the cohomology algebra of

X
X

generated by divisor classes. We construct smooth complex projective varieties whose Lefschetz algebras do not satisfy analogues of the hard Lefschetz theorem and Poincaré duality.
On a special case of Watkins’ conjecture
Authors: Kazalicki Matija , Kohen Daniel
Published: April 2017

Watkins’ conjecture asserts that for a rational elliptic curve

E
E

the degree of the modular parametrization is divisible by

2
r

2^r

, where

r
r

is the rank of

E
E

. In this paper, we prove that if the modular degree is odd, then

E
E

has rank zero. Moreover, we prove that the conjecture holds for all rank two rational elliptic curves of prime conductor and positive discriminant.
A remark on the product property for the generalized Möbius function
Authors: Jarnicki Marek , Pflug Peter
Published: April 2017

We discuss an example related to the product property for the generalized Möbius function.
Generation of Siegel modular function fields of even level
Authors: Yoon Dong Sung
Published: April 2017

For positive integers

g
g

and

N
N

, let

F

N

(
g
)

\mathcal {F}_N^{(g)}

be the field of meromorphic Siegel modular functions of genus

g
g

and level

N
N

whose Fourier coefficients belong to the

N
N

th cyclotomic field. We construct explicit generators of

F

N

(
g
)

\mathcal {F}_N^{(g)}

over

F

1

(
g
)

\mathcal {F}_1^{(g)}

by making use of a quotient of theta constants, when

g
≥
2

g\geq 2

and

N
N

is even.
A Bayesian group sparse multi-task regression model for imaging genetics
Authors: Greenlaw Keelin , Szefer Elena , Graham Jinko , Lesperance Mary , Nathoo Farouk S ,   Alzheimer’s Disease Neuroimaging Initiative
Published: April 2017

Motivation

Recent advances in technology for brain imaging and high-throughput genotyping have motivated studies examining the influence of genetic variation on brain structure. Wang et al. have developed an approach for the analysis of imaging genomic studies using penalized multi-task regression with regularization based on a novel group l2,1-norm penalty which encourages structured sparsity at both the gene level and SNP level. While incorporating a number of useful features, the proposed method only furnishes a point estimate of the regression coefficients; techniques for conducting statistical inference are not provided. A new Bayesian method is proposed here to overcome this limitation.

Results

We develop a Bayesian hierarchical modeling formulation where the posterior mode corresponds to the estimator proposed by Wang et al. and an approach that allows for full posterior inference including the construction of interval estimates for the regression parameters. We show that the proposed hierarchical model can be expressed as a three-level Gaussian scale mixture and this representation facilitates the use of a Gibbs sampling algorithm for posterior simulation. Simulation studies demonstrate that the interval estimates obtained using our approach achieve adequate coverage probabilities that outperform those obtained from the nonparametric bootstrap. Our proposed methodology is applied to the analysis of neuroimaging and genetic data collected as part of the Alzheimer’s Disease Neuroimaging Initiative (ADNI), and this analysis of the ADNI cohort demonstrates clearly the value added of incorporating interval estimation beyond only point estimation when relating SNPs to brain imaging endophenotypes.

Availability and Implementation

Software and sample data is available as an R package ‘bgsmtr’ that can be downloaded from The Comprehensive R Archive Network (CRAN).

Supplementary information

Supplementary data are available at Bioinformatics online.
EigenTHREADER: analogous protein fold recognition by efficient contact map threading
Authors: Buchan Daniel W A , Jones David T
Published: April 2017

Motivation

Protein fold recognition when appropriate, evolutionarily-related, structural templates can be identified is often trivial and may even be viewed as a solved problem. However in cases where no homologous structural templates can be detected, fold recognition is a notoriously difficult problem (Moult et al., 2014). Here we present EigenTHREADER, a novel fold recognition method capable of identifying folds where no homologous structures can be identified. EigenTHREADER takes a query amino acid sequence, generates a map of intra-residue contacts, and then searches a library of contact maps of known structures. To allow the contact maps to be compared, we use eigenvector decomposition to resolve the principal eigenvectors these can then be aligned using standard dynamic programming algorithms. The approach is similar to the Al-Eigen approach of Di Lena et al. (2010), but with improvements made both to speed and accuracy. With this search strategy, EigenTHREADER does not depend directly on sequence homology between the target protein and entries in the fold library to generate models. This in turn enables EigenTHREADER to correctly identify analogous folds where little or no sequence homology information is.

Results

EigenTHREADER outperforms well-established fold recognition methods such as pGenTHREADER and HHSearch in terms of True Positive Rate in the difficult task of analogous fold recognition. This should allow template-based modelling to be extended to many new protein families that were previously intractable to homology based fold recognition methods.

Availability and implementation

All code used to generate these results and the computational protocol can be downloaded from https://github.com/DanBuchan/eigen_scripts. EigenTHREADER, the benchmark code and the data this paper is based on can be downloaded from: http://bioinfadmin.cs.ucl.ac.uk/downloads/eigenTHREADER/.
Regulation of hematopoiesis and immune responses by long non-coding RNAs
Authors: Seo Wooseok , Taniuchi Ichiro
Published: April 2017

Since the first draft of the human genome sequence was released in 2001, unprecedentedly rapid progress has been made in whole genome-wide approaches by utilizing next-generation-sequencing technologies. The last decade alone has generated enormous data in the forms of exome sequencing, transcriptomes, transcription factor occupancy, genomic variation profiling and epigenetic modifications. One of the most striking realizations from sequencing studies has been the discovery and characterization of non-coding RNAs (ncRNAs). Although the extent to which ncRNAs are functional in vivo is still a controversial topic, there is at least a consensus that some ncRNAs are functional and that they play various roles in biology. Among the several kinds of ncRNAs, long ncRNAs (lncRNAs) in particular have received more attention because they have a larger potential to act as multifunctional regulators. Not surprisingly, researchers in the field of immunology have started to examine ncRNAs as new regulatory mechanisms. In this review, we will summarize some lncRNAs that have been reported to function in the immune system and then argue that there is still a long way to go before we can achieve a complete understanding of lncRNAs.
Theoretical study of an LAE–C iv absorption pair at z = 5.7
Authors: García L. A. , Tescari E. , Ryan-Weber E. V. , Wyithe J. S. B.
Published: April 2017

We present a theoretical model to predict the properties of an observed z = 5.72 Lyman α emitter galaxy–C iv absorption pair separated by 1384 comoving kpc h−1. We use the separation of the pair and an outflow velocity/time travelling argument to demonstrate that the observed galaxy cannot be the source of metals for the C iv absorber. We find a plausible explanation for the metal enrichment in the context of our simulations: a dwarf galaxy with M⋆ = 1.87 × 109 M⊙ located 119 comoving kpc h−1 away with a wind velocity of ∼100 km s−1 launched at z ∼ 7. Such a dwarf (MUV = −20.5) is fainter than the detection limit of the observed example. In a general analysis of galaxy–C iv absorbers, we find galaxies with − 20.5 <MUV < −18.8 are responsible for the observed metal signatures. In addition, we find no correlation between the mass of the closest galaxy to the absorber and the distance between them, but a weak anti-correlation between the strength of the absorption and the separation of galaxy–absorber pairs.
Machine learning challenges and impact: an interview with Thomas Dietterich
Authors: Zhou Zhi-Hua
Published: April 2017

Machine learning is the driving force of the hot artificial intelligence (AI) wave. In an interview with NSR, Prof. Thomas Dietterich, the distinguished professor emeritus of computer science at Oregon State University in the USA, the former president of Association of Advancement of Artificial Intelligence (AAAI, the most prestigious association in the field of artificial intelligence) and the founding president of the International Machine Learning Society, talked about exciting recent advances and technical challenges of machine learning, as well as its big impact on the world.
Fear of Falling in People With Multiple Sclerosis: Which Clinical Characteristics Are Important?
Authors: Khalil Hanan , Al-Shorman Alham , El-Salem Khalid , Abdo Nour , Alghwiri Alia A. , Aburub Aseel , Shalabi Sarah , Al-Mustafa Firas
Published: April 2017

Background. Fear of falling (FOF) is an important risk indicator for health-related outcomes and quality of life in patients with multiple sclerosis (MS). However, factors associated with FOF in MS are not well investigated.

Objectives. This study was done to explore predictors of FOF in this population.

Methods. Seventy relapsing remitting patients with MS were evaluated. Fear of falling was assessed using the Fall Efficacy Scale–International (FES-I). Motor outcomes included: 30-second chair stand test (30s-CST), Berg Balance Scale (BBS), 10-Meter Walk Test (10MWT), and 6-Minute Walk Test (6MWT). Cognitive status was determined using the Montréal Cognitive Assessment (MOCA) and Symbol Digit Modalities Test (SDMT). Affective factors including depression, fatigue, and sleep were also assessed using the Beck Depression Inventory (BDI), Modified Fatigue Impact Scale (MFIS), and Pittsburgh Sleep Quality Index (PSQI), respectively.

Results. Fear of falling was significantly correlated with all motor and affective measures used. However, a stepwise regression found that only BBS from motor measures, MOCA from cognitive measures, and sleep disorders from affective factors were significantly predictive of the FOF.

Conclusions. Fear of falling in patients with MS is multifactorial and includes motor and nonmotor factors. Thus, therapies that aim to reduce risk of falling in this population should address motor functions, cognitive abilities, and sleep quality.
Current Controversies in Prenatal Diagnosis 2: For Those Women Screened by NIPT Using Cell-Free DNA, Maternal Serum Markers Are Obsolete
Authors: Yaron Yuval , Hyett Jon , Langlois Sylvie
Published: April 2017

(Abstracted from Prenat Diagn 2016;36:1167–1171)

Clinical prenatal care includes prenatal testing for fetal birth defects, traditionally including screening with maternal serum biochemical marker(s) to detect open neural tube defects, Down syndrome, or trisomy 18. Recent advances have led to the development of noninvasive prenatal testing using cell-free DNA (cfDNA) derived from the placenta and circulating in maternal blood.
The Hidden Value of Narrative Comments for Assessment: A Quantitative Reliability Analysis of Qualitative Data
Authors: Ginsburg Shiphra , van der Vleuten Cees P.M. , Eva Kevin W.
Published: April 2017

Purpose

In-training evaluation reports (ITERs) are ubiquitous in internal medicine (IM) residency. Written comments can provide a rich data source, yet are often overlooked. This study determined the reliability of using variable amounts of commentary to discriminate between residents.

Method

ITER comments from two cohorts of PGY-1s in IM at the University of Toronto (graduating 2010 and 2011; n = 46–48) were put into sets containing 15 to 16 residents. Parallel sets were created: one with comments from the full year and one with comments from only the first three assessments. Each set was rank-ordered by four internists external to the program between April 2014 and May 2015 (n = 24). Generalizability analyses and a decision study were performed.

Results

For the full year of comments, reliability coefficients averaged across four rankers were G = 0.85 and G = 0.91 for the two cohorts. For a single ranker, G = 0.60 and G = 0.73. Using only the first three assessments, reliabilities remained high at G = 0.66 and G = 0.60 for a single ranker. In a decision study, if two internists ranked the first three assessments, reliability would be G = 0.80 and G = 0.75 for the two cohorts.

Conclusions

Using written comments to discriminate between residents can be extremely reliable even after only several reports are collected. This suggests a way to identify residents early on who may require attention. These findings contribute evidence to support the validity argument for using qualitative data for assessment.
Role of Computed Tomography in the Classification of Pediatric Pelvic Fractures—Revisited
Authors: Bent Melissa A. , Hennrikus William L. , Latorre Johan E. , Armstrong Douglas G. , Shaw Brian , Jones Kerwyn C. , Segal Lee S.
Published: April 2017

Objectives:

To determine the need for computerized tomography (CT) scans in the assessment of pediatric pelvic fractures.

Design:

Retrospective Chart Review.

Setting:

Level-1 Pediatric Trauma Center.

Patients/Participants:

Thirty pediatric trauma patients with pelvic fractures who have obtained both a radiograph and CT scan.

Main Outcome Measurements:

Fleiss Kappa coefficient to compare interreliability.

Results:

The average age of the patients was 7 years (range 1–13 years). Seventeen were males and 13 were females. The Torode and Zieg classification included 3 type I, 6 type II, 13 type III, and 8 type IV. The Kappa value for interobserver agreement comparing radiographs was 0.453, and for CT was 0.42. Three patients (10%) were treated with a spica cast, and none required surgery for their pelvic fracture. Four patients (11%) demonstrated liver, spleen, or kidney injuries on CT. Out of those 4, 1 had indications for laparotomy and drain placement, 1 died secondary to shock, and 2 were treated conservatively.

Conclusions:

The results of this study demonstrated that plain radiographs alone can be used to classify and manage most pediatric fractures, confirming Silber previous findings. Furthermore, we recommend the specific instances of Schreck and Haasz et al in which CT scans should be used, sparing the general pediatric population unnecessary radiation. Such cases include patients with an abnormal abdominal or pelvic examination, complex fracture patterns, displacement greater than 1 cm, femur deformities, hematuria, Glasgow Coma Scale <13, hemodynamic instability, an aspartate aminotransferase > 200 U/L, an Hct < 30%, or an abnormal chest x-ray.
Pheochromocytoma Crisis in the ICU: A French Multicenter Cohort Study With Emphasis on Rescue Extracorporeal Membrane Oxygenation
Authors: Sauneuf Bertrand , Chudeau Nicolas , Champigneulle Benoit , Bouffard Claire , Antona Marion , Pichon Nicolas , Marrache David , Sonneville Romain , Marchalot Antoine , Welsch Camille , Kimmoun Antoine , Bouchet Bruno , Messai Elmi , Ricome Sylvie , Grimaldi David , Chelly Jonathan , Hanouz Jean-Luc , Mercat Alain , Terzi Nicolas
Published: April 2017

Objectives:

To describe the characteristics, management, and outcome of patients admitted to ICUs for pheochromocytoma crisis.

Design:

A 16-year multicenter retrospective study.

Setting:

Fifteen university and nonuniversity ICUs in France.

Patients:

Patients admitted in ICU for pheochromocytoma crisis.

Interventions:

None.

Measurement and Main Results:

We included 34 patients with a median age of 46 years (40–54 yr); 65% were males. At admission, the median Sequential Organ Failure Assessment score was 8 (4–12) and median Simplified Acute Physiology Score II 49.5 (27–70). The left ventricular ejection fraction was consistently decreased with a median value of 30% (15–40%). Mechanical ventilation was required in 23 patients, mainly because of congestive heart failure. Vasoactive drugs were used in 23 patients (68%) and renal replacement therapy in eight patients (24%). Extracorporeal membrane oxygenation was used as a rescue therapy in 14 patients (41%). Pheochromocytoma was diagnosed by CT in 33 of 34 patients. When assayed, urinary metanephrine and catecholamine levels were consistently elevated. Five patients underwent urgent surgery, including two during extracorporeal membrane oxygenation. Overall ICU mortality was 24% (8/34), and overall 90-day mortality was 27% (9/34). Crude 90-day mortality was not significantly different between patients managed with versus without extracorporeal membrane oxygenation (22% vs 30%) (p = 0.7) despite higher severity scores at admission in the extracorporeal membrane oxygenation group.

Conclusions:

Mortality is high in pheochromocytoma crisis. Routinely considering this diagnosis and performing abdominal CT in patients with unexplained cardiogenic shock may allow an earlier diagnosis. Extracorporeal membrane oxygenation and adrenalectomy should be considered as a therapeutic in most severe cases.
Detection of Pulmonary Embolism During Cardiac Arrest—Ultrasonographic Findings Should Be Interpreted With Caution*
Authors: Aagaard Rasmus , Caap Philip , Hansson Nicolaj C. , Bøtker Morten T. , Granfeldt Asger , Løfgren Bo
Published: April 2017

Objectives:

The aim of this study was to test the hypothesis that the right ventricle is more dilated during resuscitation from cardiac arrest caused by pulmonary embolism, compared with hypoxia and primary arrhythmia.

Design:

Twenty-four pigs were anesthetized and cardiac arrest was induced using three different methods. Pigs were resuscitated after 7 minutes of untreated cardiac arrest. Ultrasonographic images were obtained and the right ventricular diameter was measured.

Setting:

University hospital animal laboratory.

Subjects:

Female crossbred Landrace/Yorkshire/Duroc pigs (27–32 kg).

Interventions:

Pigs were randomly assigned to cardiac arrest induced by pulmonary embolism, hypoxia, or primary arrhythmia.

Measurements and Main Results:

There was no difference at baseline. During induction of cardiac arrest, the right ventricle dilated in all groups (p < 0.01 for all). The primary endpoint was right ventricle diameter at the third rhythm analysis: 32 mm (95% CI, 29–36) for pulmonary embolism which was significantly larger than both hypoxia: 23 mm (95% CI, 20–27) and primary arrhythmia: 25 mm (95% CI, 22–28)—the absolute difference was 7–9 mm. Physicians with basic training in focused cardiac ultrasonography were able to detect a difference in right ventricle diameter of approximately 10 mm with a sensitivity of 79% (95% CI, 64–94) and a specificity of 68% (95% CI, 56–80).

Conclusions:

The right ventricle was more dilated during resuscitation when cardiac arrest was caused by pulmonary embolism compared with hypoxia and primary arrhythmia. However, the right ventricle was dilated, irrespective of the cause of arrest, and diagnostic accuracy by physicians with basic training in focused cardiac ultrasonography was modest. These findings challenge the paradigm that right ventricular dilatation on ultrasound during cardiopulmonary resuscitation is particularly associated with pulmonary embolism.
Plaque-Like Myofibroblastic Tumor: Report of 4 Cases
Authors: Moulonguet Isabelle , Biaggi Annonciade , Eschard Catherine , Durlach Anne , Stock Nathalie , Delanoé Philippe , Coussirat-Voreaux Marie-France , Fraitag Sylvie
Published: April 2017

Plaque-like myofibroblastic tumor of infancy was first characterized in 2007 by Clarke et al. In the first 2 cases described, large plaque-like tumors presented in the first 3 months of life exhibited microscopic features consistent with dermatofibroma but with immunohistochemical features of myofibroblastic lineage. In 2013, Marqueling et al reported 3 additional cases, 2 of which presented in early childhood, prompting the authors to recommend that the name of this condition be shortened to plaque-like myofibroblastic tumor. We present here 4 additional cases to better characterize clinical and histopathological features of this newly recognized entity. This benign lesion is of myofibroblastic lineage and demonstrates features consistent with multiple clustered dermatofibroma.
CLINICAL PRESENTATION, MICROBIOLOGIC PROFILE AND FACTORS PREDICTING OUTCOMES IN BACILLUS ENDOPHTHALMITIS
Authors: Dave Vivek P. , Pathengay Avinash , Budhiraja Ina , Sharma Savitri , Pappuru Rajeev R. , Tyagi Mudit , Narayanan Raja , Jalali Subhadra , Chhablani Jay , Das Taraprasad
Published: April 2017

Purpose:

To describe the clinical presentation, microbiologic profile, and factors predicting outcomes in Bacillus endophthalmitis.

Methods:

Retrospective interventional case series. Eighty-six patients with culture-proven Bacillus endophthalmitis, from January 2001 to December 2015, underwent vitrectomy/vitreous biopsy and intravitreal antibiotic with or without steroid as appropriate. The undiluted vitreous biopsy was subjected to microbiologic evaluation. The duration of symptoms, presenting visual acuity, organisms isolated, influence of intravitreal dexamethasone with intravitreal antibiotics, and type of initial intervention were examined for any clinical and statistical correlation in terms of odds ratio with the final visual outcome.

Results:

Trauma was the commonest etiology (n = 75; 87.2%). Mixed infection with other bacteria was seen in 11 patients. All Bacillus species were sensitive to gentamicin followed by ciprofloxacin (n = 85; 98.83%) and vancomycin (n = 81; 94.18%). Odds in favor of a favorable visual outcome were seen with clinical treatment within 48 hours of the symptoms (OR 25.47, 95% CI 2.45–254.16, P = 0.006), better presenting vision (OR 31.21, 95% CI 2.96–323.64, P = 0.004), and absence of polymicrobial infection (OR 18.03, 95% CI 0.9–344.4, P = 0.05). Only 20% of all treated patients regained ambulatory vision, and one fifth of all of them developed phthisis.

Conclusion:

Patients diagnosed with Bacillus endophthalmitis merit aggressive vitreous intervention guided by the culture-sensitivity report. Despite early and appropriate treat ment, the outcomes are generally poor.
SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY FINDINGS IN MACULA-INVOLVING CYTOMEGALOVIRUS RETINITIS
Authors: Gupta Mrinali P. , Patel Sarju , Orlin Anton , Marlow Elizabeth , Chee Ru-Ik , Nadelmann Jennifer , Chan R.V.Paul , D'Amico Donald J. , Kiss Szilard
Published: April 2017

Purpose:

To evaluate the microstructural features of cytomegalovirus (CMV) retinitis by spectral domain optical coherence tomography (OCT).

Methods:

Subjects were patients with macula-involving CMV retinitis with OCT imaging. The leading edge of retinitis in the macula was identified based on fundus imaging, and OCT findings were longitudinally evaluated in three areas: within the area of active retinitis, at the leading edge of retinitis, and just beyond the leading edge of retinitis.

Results:

Optical coherence tomography imaging of macular CMV retinitis identified vitreous cells in 10 eyes (100%), posterior vitreous detachment in four eyes (40%), broad-based vitreomacular traction in one eye (10%), epiretinal membrane in eight eyes (80%), and lamellar hole–associated epiretinal proliferation associated with an atrophic hole in one eye (10%). Retinal architectural disruption, disruption of inner retinal layers, disruption of the external limiting membrane, and ellipsoid zone abnormalities were noted within the area of retinitis in all eyes and decreased in frequency and severity at and beyond the leading edge of retinitis, although all 10 eyes (100%) exhibited one of these abnormalities, especially outer retinal microabnormalities, beyond the leading edge of retinitis.

Conclusion:

Microstructural abnormalities were frequently noted on OCT of CMV retinitis, including within the retina beyond the leading edge of retinitis identified by corresponding fundus imaging. Outer retinal abnormalities were noted more frequently than inner retinal abnormalities beyond the leading edge of retinitis. These findings provide insight into the effects of CMV retinitis on retinal microstructure and potentially on vision and highlight the potential utility of OCT for monitoring microprogression of macula-involving CMV retinitis.
Disparities in Standard of Care Treatment and Associated Survival Decrement in Patients With Locally Advanced Cervical Cancer
Authors: Robin Tyler P. , Amini Arya , Schefter Tracey E. , Behbakht Kian , Fisher Christine M.
Published: April 2017

(Abstracted from Gynecol Oncol 2016;143:319–325)

Brachytherapy has been shown to increase survival in patients with cervical cancer when added to external beam radiation. Standard of care (SOC) treatment for locally advanced cervical cancer includes concurrent chemotherapy with external beam radiation therapy (EBRT) plus brachytherapy.
Association Between the Birth of an Infant With Major Congenital Anomalies and Subsequent Risk of Mortality in Their Mothers
Authors: Cohen Eyal , Horváth-Puhó Erzsébet , Ray Joel G. , Pedersen Lars , Adler Nancy , Ording Anne Gulbech , Wise Paul H. , Milstein Arnold , Sørensen Henrik Toft
Published: April 2017

(Abstracted from JAMA 2016;316(23):2515–2524)

Medical science is advancing. Consequently, the survival rate of children born with genetic congenital anomalies has improved.
Neonatal Abstinence Syndrome
Authors: McQueen Karen , Murphy-Oikonen Jodie
Published: April 2017

(Abstracted from N Engl J Med 2016;375:2468–2479)

Neonatal abstinence syndrome (NAS) is a postnatal opioid withdrawal syndrome occurring in 55% to 94% of newborns whose mothers were addicted to or treated with opioids while pregnant. A lack of clarity and consistency regarding the definition, measurement, and management of the syndrome still exists.
New Human Immunodeficiency Virus Diagnosis Independently Associated With Rectal Gonorrhea and Chlamydia in Men Who Have Sex With Men
Authors: Barbee Lindley A. , Khosropour Christine M. , Dombrowksi Julia C. , Golden Matthew R.
Published: April 2017

Background

Rectal sexually transmitted infections (STI) have been associated with human immunodeficiency virus (HIV) diagnosis, but inferring a causal association requires disentangling them from receptive anal intercourse (RAI).

Methods

We conducted a stratified case-control study by frequency matching 4 controls to each case within year using clinical data from men who have sex with men (MSM) attending the Seattle STD Clinic 2001 to 2014. Cases were MSM with a new HIV diagnosis and negative HIV test at 12 months or less. Controls were HIV-negative MSM. All included men had rectal STI testing, tested negative for syphilis, and had complete sexual behavior data. We categorized men by RAI: (1) none; (2) condoms for all RAI; (3) condomless RAI only with HIV-negative partners; and (4) condomless RAI with HIV-positive or unknown-status partners. We created 3 logistic regression models: (1) 3 univariate models of concurrent rectal gonorrhea, rectal chlamydia, and rectal STI in 12 months or less with new HIV diagnosis; (2) those 3 infections, plus age, race, year, number of sexual partners in 2 months or less, and methamphetamine use; and (3) model 2 with RAI categories. We calculated the population attributable risk of rectal STI on HIV diagnoses.

Results

Among 176 cases and 704 controls, rectal gonorrhea, chlamydia and rectal STI in 12 months or less were associated with HIV diagnosis. The magnitude of these associations attenuated in the second model, but persisted in model 3 (gonorrhea: adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.3–3.8; chlamydia: aOR, 2.5; 95% CI, 1.5–4.3; prior STI: aOR, 3.0; 95% CI, 1.5–6.2). One in 7 HIV diagnoses can be attributed to rectal STI.

Conclusions

Rectal STI are independently associated with HIV acquisition. These findings support the hypothesis that rectal STI play a biologically mediated causal role in HIV acquisition and support screening/treatment of STI for HIV prevention.