bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistical features of rapidly rotating decaying turbulence: Enstrophy and energy spectra and coherent structures
Authors: Sharma Manohar K. , Kumar Abhishek , Verma Mahendra K. , Chakraborty Sagar
Published: April 2018

In this paper, we investigate the properties of rapidly rotating decaying turbulence using numerical simulations and phenomenological modeling. We find that as the turbulent flow evolves in time, the Rossby number decreases to ∼10−3, and the flow becomes quasi-two-dimensional with strong coherent columnar structures arising due to the inverse cascade of energy. We establish that a major fraction of energy is confined in Fourier modes (±1, 0, 0) and (0, ±1, 0) that correspond to the largest columnar structure in the flow. For wavenumbers (k) greater than the enstrophy dissipation wavenumber (kd), our phenomenological arguments and numerical study show that the enstrophy flux and spectrum of a horizontal cross section perpendicular to the axis of rotation are given by ϵω⁡exp(−C(k/kd)2) and Cϵω2/3k−1⁡exp(−C(k/kd)2), respectively; for this 2D flow, ϵω is the enstrophy dissipation rate, and C is a constant. Using these results, we propose a new form for the energy spectrum of rapidly rotating decaying turbulence: E(k)=Cϵω2/3k−3⁡exp(−C(k/kd)2). This model of the energy spectrum is based on wavenumber-dependent enstrophy flux, and it deviates significantly from power law energy spectrum reported earlier.
Effect of wetting on nucleation and growth of D2 in confinement
Authors: Zepeda-Ruiz L. A. , Sadigh B. , Shin S. J. , Kozioziemski B. J. , Chernov A. A.
Published: April 2018

We have performed a computational study to determine how the wetting of liquid deuterium to the walls of the material influences nucleation. We present the development of a pair-wise interatomic potential that includes zero-point motion of molecular deuterium. Deuterium is used in this study because of its importance to inertial confinement fusion and the potential to generate a superfluid state if the solidification can be suppressed. Our simulations show that wetting dominates undercooling compared to the pore geometries. We observe a transition from heterogeneous nucleation at the confining wall to homogeneous nucleation at the bulk of the liquid (and intermediate cases) as the interaction with the confining wall changes from perfect wetting to non-wetting. When nucleation is heterogeneous, the temperature needed for solidification changes by 4 K with decreasing deuterium-wall interaction, but it remains independent (and equal to the one from bulk samples) when homogeneous nucleation dominates. We find that growth and quality of the resulting microstructure also depends on the magnitude of liquid deuterium–wall interaction strength.
Effective diffusion coefficient including the Marangoni effect
Authors: Kitahata Hiroyuki , Yoshinaga Natsuhiko
Published: April 2018

Surface-active molecules supplied from a particle fixed at the water surface create a spatial gradient of the molecule concentration, resulting in Marangoni convection. Convective flow transports the molecules far from the particle, enhancing diffusion. We analytically derive the effective diffusion coefficient associated with the Marangoni convection rolls. The resulting estimated effective diffusion coefficient is consistent with our numerical results and the apparent diffusion coefficient measured in experiments.
Electrostatic odd symmetric eigenmode in inhomogeneous Bernstein-Greene-Kruskal equilibrium
Authors: Woo M.-H. , Dokgo K. , Yoon Peter H. , Lee D.-Y. , Choi Cheong R.
Published: April 2018

A self-consistent electrostatic odd-symmetric eigenmode (OEM) is analytically found in a solitary type Bernstein-Greene-Kruskal (BGK) equilibrium. The frequency of the OEM is order of the electron bounce frequency and it is spatially odd-symmetric with the scale comparable to that of the solitary BGK equilibrium structure. Such an OEM is consistent with the recent observation from particle-in-cell simulation of the solitary wave [Dokgo et al., Phys. Plasmas 23, 092107 (2016)]. The mode can be driven unstable by trapped electrons within the hole structure of the solitary wave. Such a low frequency, pure electron mode, which may possibly interact resonantly with the ion acoustic mode, provides a possible damping mechanism of the BGK equilibrium.
Dissociation dynamics of 3- and 4-nitrotoluene radical cations: Coherently driven C–NO2 bond homolysis
Authors: Ampadu Boateng Derrick , Gutsev Gennady L. , Jena Puru , Tibbetts Katharine Moore
Published: April 2018

Monosubstituted nitrotoluenes serve as important model compounds for nitroaromatic energetic molecules such as trinitrotoluene. This work investigates the ultrafast nuclear dynamics of 3- and 4-nitrotoluene radical cations using femtosecond pump-probe measurements and the results of density functional theory calculations. Strong-field adiabatic ionization of 3- and 4-nitrotoluene using 1500 nm, 18 fs pulses produces radical cations in the ground electronic state with distinct coherent vibrational excitations. In both nitrotoluene isomers, a one-photon excitation with the probe pulse results in NO2 loss to form C7H7+, which exhibits out-of-phase oscillations in yield with the parent molecular ion. The oscillations in 4-nitrotoluene with a period of 470 fs are attributed to the torsional motion of the NO2 group based on theoretical results showing that the dominant relaxation pathway in 4-nitrotoluene radical cations involves the rotation of the NO2 group away from the planar geometry. The distinctly faster oscillation period of 216 fs in 3-nitrotoluene is attributed to an in-plane bending motion of the NO2 and CH3 moieties based on analysis of the normal modes. These results demonstrate that coherent nuclear motions determine the probability of C–NO2 homolysis in the nitrotoluene radical cations upon optical excitation within several hundred femtoseconds of the initial ionization event.
On channel interactions in nested Hall thrusters
Authors: Cusson S. E. , Georgin M. P. , Dragnea H. C. , Dale E. T. , Dhaliwal V. , Boyd I. D. , Gallimore A. D.
Published: April 2018

Nested Hall thrusters use multiple, concentric discharge channels to increase thrust density. They have shown enhanced performance in multi-channel operation relative to the superposition of individual channels. The X2, a two-channel nested Hall thruster, was used to investigate the mechanism behind this improved performance. It is shown that the local pressure near the thruster exit plane is an order of magnitude higher in two-channel operation. This is due to the increased neutral flow inherent to the multi-channel operation. Due to the proximity of the discharge channels in nested Hall thrusters, these local pressure effects are shown to be responsible for the enhanced production of thrust during multi-channel operation via two mechanisms. The first mechanism is the reduction of the divergence angle due to an upstream shift of the acceleration region. The displacement of the acceleration region was detected using laser induced fluorescence measurements of the ion velocity profile. Analysis of the change in beam divergence indicates that, at an operating condition of 150 V and 30 A, this effect increases the thrust by 8.7 ± 1.2 mN. The second mechanism is neutral ingestion from the adjacent channel resulting in a 2.0 + 0/−0.2 mN increase in thrust. Combined, these mechanisms are shown to explain, within uncertainty, the 17 ± 6.2 mN improvement in thrust during dual channel operation of the X2.
Study of perovskite heterostructures shows how crystal geometry intricately responds to strain
Authors: Liebendorfer Adam
Published: April 2018

An in-depth analysis of lanthanum vanadate using X-ray diffraction and scanning transmission electron microscopy has revealed the changes in the thin film’s geometry induced by epitaxial strain.
Combination of reversible resistive and ferroelectric switching demonstrated in HfO2
Authors: Wolverton Mark
Published: April 2018

Experimenters demonstrate ferroelectric-resistive-ferroelectric behavior within a single capacitor stack.
Thousands of tons of mercury are trapped in permafrost
Authors: Miller Johanna L.
Published: April 2018

As Earth’s frozen soils thaw, they’ll have a significant effect on the global mercury cycle.
Lab experiments mimic the origin and growth of astrophysical magnetic fields
Authors: Berkowitz Rachel
Published: April 2018

A turbulent, laser-generated plasma can amplify magnetic fields to cosmic scales.
Nuclear weapons dangers and policy options
Authors: Fetter Steve , Garwin Richard L. , von Hippel Frank
Published: April 2018

With the end of the Cold War, most physicists turned their attention away from the nuclear threat. It is now time for us to reengage in the debate over how to reduce the dangers from nuclear weapons.
Objectively measured physical activity, body composition and physical fitness: Cross‐sectional associations in 9‐ to 15‐year‐old children
Authors: Joensuu Laura , Syväoja Heidi , Kallio Jouni , Kulmala Janne , Kujala Urho M. , Tammelin Tuija H.
Published: April 2018

The aim of this study was to examine and quantify the cross‐sectional associations of body composition (BC), physical activity (PA) and sedentary time (ST) with physical fitness (PF) in children and adolescents. A sample of 594 Finnish students (56% girls), aged 9–15 (12.4 ± 1.3 years) were selected for a study performed in 2013. The measurements of the Move! monitoring system for physical functional capacity were used to measure cardiorespiratory and musculoskeletal fitness and fundamental movement skills. Moderate‐to‐vigorous PA (MVPA) and ST were measured objectively with an accelerometer and BC by a bioelectrical impedance analysis. Fat mass index (FMI) and fat‐free mass index (FFMI) were calculated to represent height‐adjusted BC. Associations were explored with a linear regression model. In general, FMI had statistically significant negative associations, while FFMI and MVPA had positive associations with PF. No statistically significant associations were observed between ST and PF. In general, FMI had the strongest association with PF, although some variation occurred with sex and PF component. However, associations were practically relevant only in 20‐m shuttle run, push‐up, curl‐up and 5‐leaps test. For example, approximately 5 kg increase in fat mass in 155 cm tall children was estimated to correspond to  8 laps in 20‐m shuttle run. Similar increase in fat‐free mass corresponded to +4 and +6 laps, and 10 min increase in daily MVPA +3 and +2 laps in 20‐m shuttle run, in boys and girls, respectively. Understanding these associations is necessary when interpreting children's PF and designing interventions.
Uhrf1 regulates germinal center B cell expansion and affinity maturation to control viral infection
Authors: Chen Chao , Zhai Sulan , Zhang Le , Chen Jingjing , Long Xuehui , Qin Jun , Li Jianhua , Huo Ran , Wang Xiaoming
Published: April 2018

The production of high-affinity antibody is essential for pathogen clearance. Antibody affinity is increased through germinal center (GC) affinity maturation, which relies on BCR somatic hypermutation (SHM) followed by antigen-based selection. GC B cell proliferation is essentially involved in these processes; it provides enough templates for SHM and also serves as a critical mechanism of positive selection. In this study, we show that expression of epigenetic regulator ubiquitin-like with PHD and RING finger domains 1 (Uhrf1) was markedly up-regulated by c-Myc–AP4 in GC B cells, and it was required for GC response. Uhrf1 regulates cell proliferation–associated genes including cdkn1a, slfn1, and slfn2 by DNA methylation, and its deficiency inhibited the GC B cell cycle at G1-S phase. Subsequently, GC B cell SHM and affinity maturation were impaired, and Uhrf1 GC B knockout mice were unable to control chronic virus infection. Collectively, our data suggest that Uhrf1 regulates GC B cell proliferation and affinity maturation, and its expression in GC B cells is required for virus clearance.
The Influence Analysis of the Rainfall Meteorological Conditions on the Operation of the Balloon Borne Radar in Plateau
Authors: Li Qiong , Geng Fangzhi
Published: April 2018

Based on the characteristics of complex terrain and different seasons’ weather in Qinghai Tibet Plateau, through statistic the daily rainfall that from 2002 to 2012, nearly 11 years, by Bomi meteorological station, Bomi area rainfall forecast model is established, and which can provide the basis forecasting for dangerous weather warning system on the balloon borne radar in the next step, to protect the balloon borne radar equipment’s safety work and combat effectiveness.
B-cell receptor reconstruction from single-cell RNA-seq with VDJPuzzle
Authors: Rizzetto Simone , Koppstein David N P , Samir Jerome , Singh Mandeep , Reed Joanne H , Cai Curtis H , Lloyd Andrew R , Eltahla Auda A , Goodnow Christopher C , Luciani Fabio
Published: April 2018

Motivation

The B-cell receptor (BCR) performs essential functions for the adaptive immune system including recognition of pathogen-derived antigens. The vast repertoire and adaptive variation of BCR sequences due to V(D)J recombination and somatic hypermutation necessitates single-cell characterization of BCR sequences. Single-cell RNA sequencing presents the opportunity for simultaneous capture of paired BCR heavy and light chains and the transcriptomic signature.

Results

We developed VDJPuzzle, a novel bioinformatic tool that reconstructs productive, full-length B-cell receptor sequences of both heavy and light chains and extract somatic mutations on the VDJ region. VDJPuzzle successfully reconstructed BCRs from 100% (n=117) human and 96.5% (n=200) murine B cells. The reconstructed BCRs were successfully validated with single-cell Sanger sequencing.

Availability and implementation

VDJPuzzle is available at https://bitbucket.org/kirbyvisp/vdjpuzzle2.

Supplementary information

Supplementary data are available at Bioinformatics online.
Sox17 is essential for proper formation of the marginal zone of extraembryonic endoderm adjacent to a developing mouse placental disk†
Authors: Igarashi Hitomi , Uemura Mami , Hiramatsu Ryuji , Hiramatsu Ryuto , Segami Saki , Pattarapanawan Montri , Hirate Yoshikazu , Yoshimura Yuki , Hashimoto Haruo , Higashiyama Hiroki , Sumitomo Hiroyuki , Kurohmaru Masamichi , Saijoh Yukio , Suemizu Hiroshi , Kanai-Azuma Masami , Kanai Yoshiakira
Published: April 2018

In mouse conceptus, two yolk-sac membranes, the parietal endoderm (PE) and visceral endoderm (VE), are involved in protecting and nourishing early-somite-stage embryos prior to the establishment of placental circulation. Both PE and VE membranes are tightly anchored to the marginal edge of the developing placental disk, in which the extraembryonic endoderm (marginal zone endoderm: ME) shows the typical flat epithelial morphology intermediate between those of PE and VE in vivo. However, the molecular characteristics and functions of the ME in mouse placentation remain unclear. Here, we show that SOX17, not SOX7, is continuously expressed in the ME cells, whereas both SOX17 and SOX7 are coexpressed in PE cells, by at least 10.5 days postconception. The Sox17-null conceptus, but not the Sox7-null one, showed the ectopic appearance of squamous VE-like epithelial cells in the presumptive ME region, together with reduced cell density and aberrant morphology of PE cells. Such aberrant ME formation in the Sox17-null extraembryonic endoderm was not rescued by the chimeric embryo replaced with the wild-type gut endoderm by the injection of wild-type ES cells into the Sox17-null blastocyst, suggesting the cell autonomous defects in the extraembryonic endoderm of Sox17-null concepti. These findings provide direct evidence of the crucial roles of SOX17 in proper formation and maintenance of the ME region, highlighting a novel entry point to understand the in vivo VE-to-PE transition in the marginal edge of developing placenta.
Abelian Varieties as Automorphism Groups of Smooth Projective Varieties
Authors: Lombardo Davide , Maffei Andrea
Published: April 2018

We determine which complex abelian varieties can be realized as the automorphism group of a smooth projective variety.
Training to Teach Science: Experimental Evidence from Argentina
Authors: Albornoz Facundo , Anauati María Victoria , Furman Melina , Luzuriaga Mariana , Podestá María Eugenia , Taylor Inés
Published: April 2018

This paper evaluates the learning impact of different teacher training methods using a randomized controlled trial implemented in 70 state schools in Buenos Aires, Argentina. A control group receiving standard teacher training was compared with two alternative treatment arms: providing a structured curriculum unit or receiving both the unit and weekly coaching. Following a 12-week intervention, there are substantial learning gains for students whose teachers were trained using structured curriculum units, as well as for those whose teachers received coaching (between 55 percent and 64 percent of a standard deviation more than those students in the control group). Coaching teachers does not appear to be cost-effective, as the unit cost per 0.1 standard deviation is more than twice the cost of using only the structured curriculum unit. However, additional coaching is particularly beneficial for inexperienced teachers with less than two years of teaching science. Coaching teachers also showed specific gains for girls, who both learned and declared to enjoy science lessons more. High-performing students especially benefited from both interventions, with students from coached teachers performing particularly well in harder questions. Using structured curriculum units and providing coaching also affected teacher perceptions: teachers expressed that they enjoyed teaching science more and taught more hours of science, and that their students developed more skills. Results from a follow-up survey suggest persistent change in teacher practice, with the vast majority reporting using the structured curriculum unit one year after the intervention.
Blood Flow Restriction Training in Rehabilitation Following Anterior Cruciate Ligament Reconstructive Surgery: A Review
Authors: Hughes Luke , Rosenblatt Ben , Paton Bruce , Patterson Stephen David
Published: April 2018

Anterior cruciate ligament (ACL) rupture is a highly prevalent orthopedic injury, resulting in substantial skeletal muscle atrophy because of changes in muscle protein balance and satellite cell abundance. Neural activation problems also contribute to strength loss, impacting upon a patients’ physical function and rehabilitative capacity. Heavy loads typically required for muscle hypertrophy and strength adaptations are contraindicated because of graft strain and concomitant cartilage, meniscal, and bone pathologies associated with ACL reconstruction. Strength of the quadriceps is a fundamental component for the ability to reduce shearing and torsional strains on the ACL with ground contact, and forms a critical component of ACL rehabilitation. Given the dangers of early postoperative heavy-loading, low-load blood flow restriction (BFR) training may provide an alternative rehabilitation tool for practitioners. Passive BFR can attenuate early muscle atrophy and strength loss, and may be more effective with the addition of novel, complementary therapies such as neuromuscular electrical stimulation. Upon ambulation, aerobic, and resistance exercise with BFR can stimulate muscle hypertrophy and strength adaptations and resolve activation problems. This may occur through increasing muscle protein synthesis and satellite cell proliferation, decreasing muscle protein breakdown and improving muscle activation by altered recruitment patterns. Thus, BFR training may provide an effective rehabilitation tool that does not place heavy loads and force through the tibiofemoral joint. This may reduce the risk of damaging the graft, cartilage, meniscus, or other intra-articular structures, providing thorough screening before use is followed by correct, evidence-informed application.
The Role of Blood Flow Restriction Training to Mitigate Sarcopenia, Dynapenia, and Enhance Clinical Recovery
Authors: Hackney Kyle J. , Brown LTC William J. , Stone Kara A. , Tennent David J.
Published: April 2018

Aging is associated with progressive losses of muscle mass (sarcopenia) and strength (dynapenia) leading to reduced functional capacity. Traditional aerobic and resistance exercises are commonly recommended to enhance health and mitigate aging-related performance concerns. Recently, blood flow restriction (BFR) exercise has gained scientific merit as a hybrid aerobic and resistance exercise intervention that may be suitable for application in older adults and following musculoskeletal injury to both mitigate and treat the resulting sarcopenia or dynapenia. Muscle hypertrophy ranging from <1% to 2.6% per week and muscle strength gain ranging from <1% to 5.9% per week have been reported following BFR exercise training when combined with various methods (walking, body weight, elastic bands, and traditional weight training). Further, given the projected increase in orthopedic surgeries in the aging population, the anabolic potential of BFR exercise methodology has gained additional interest the area of clinical rehabilitation following musculoskeletal insult. In particular, older adults recovering from various medical procedures may benefit from BFR exercise in order to regain muscular strength and size during recovery to avoid any additional complications from anabolic resistance, weakness, or disuse. Although care should be taken when selecting BFR exercises over traditional therapy interventions, there is evidence BFR exercise is a suitable intervention to mitigate sarcopenia and dynapenia and enhance muscle strength and mass recovery following various clinical conditions. Further, as BFR exercise provides an additional intervention to improve functional capacity by increasing muscle strength, mass and endurance, it’s utility in mitigating sarcopenia and dynapenia in at risk individuals (ie, frail elderly, postoperative) is becoming more apparent.
Moulages: Art and History of Medicine
Authors: Nocito Ana L. , Berra Hector H.
Published: April 2018

The aim of this article is to introduce the museum we have at the Pathology Department, School of Medicine of the National University of Rosario, Argentina. The origin dates from to 1922 when Dermatology Professor Dr. Enrique P. Fidanza bought moulages at L'Hôpital Saint-Louis in Paris for the purpose of teaching. The collection included around 100 moulages and was worth approximately 1000 dollars. These pieces were exhibited at the Dermatology Department for many years and later moved to the Pathology Department where some pieces started being repaired, whereas others have deteriorated. The collection is composed of 100 moulages done by a French craftsman by the name of Niclet and 258 made by Argentine craftsmen including Alba Ramirez and G. Rouzaut, among others. The pieces are classified according to different dermatological diseases such as: the different stages of syphilis, lupus, benign and malignant neoplasm, infectious diseases, etc.
Making Sense of Hypertension Guidelines
Authors: DeWald Tracy , Granger Bradi , Bowers Margaret
Published: April 2018

Hypertension is a leading risk factor for heart disease, stroke, kidney failure, and diabetes and is a predisposing risk factor for most cardiovascular chronic illnesses. The risk for major cardiovascular events drops significantly when guideline-based blood pressure targets are achieved. Several different societies and organizations have released guidelines during the past 6 years, and significant clinical trial data have been recently released. Here, we summarize existing guidelines and recent pertinent clinical trial data to assist practitioners in identifying optimal treatment strategies for the successful management of hypertension.
The Importance of Heart Rate in Heart Failure and Reduced Ejection Fraction
Authors: Prasun Marilyn A. , Albert Nancy M.
Published: April 2018

Background:

Heart failure with reduced ejection fraction (HFrEF) is a progressive, chronic, and burdensome cardiovascular condition. It is associated with limiting symptoms, such as dyspnea and fatigue; a decline in functional capacity; and premature mortality and hospitalization. In heart failure (HF) management, heart rate is commonly assessed yet frequently overlooked as a modifiable risk factor and a predictor of mortality. An elevated heart rate increases myocardial demand and decreases diastolic filling time. Hospitalized patients with HFrEF who have a heart rate greater than 70 beats per minute at discharge were found to have lower survival rates.

Purpose:

The aims of this study were to review the association between heart rate and clinical outcome in patients with HF and discuss the contribution of heart rate to HFrEF pathophysiology. Medications currently used to modulate heart rate in patients with HF are also reviewed.

Conclusions:

In patients with HFrEF, an elevated heart rate contributes to HF progression, and it is both a prognostic and modifiable risk factor. Medications such as an evidence-based β-blockers, digoxin, and ivabradine are recommended for modulation of heart rate in patients with HFrEF.

Clinical Implications:

Nurses play a pivotal role in managing HFrEF and must understand current evidence of the pathophysiology of elevated heart rate, risks, and management strategies. Early recognition of elevated heart rate and application of guideline-directed pharmacologic treatment for patients with HFrEF and an elevated heart rate remains key to improving patient outcomes.
Genetic Polymorphisms Associated With Constipation and Anticholinergic Symptoms in Patients Receiving Clozapine
Authors: Solismaa Anssi , Kampman Olli , Lyytikäinen Leo-Pekka , Seppälä Niko , Viikki Merja , Mononen Nina , Lehtimäki Terho , Leinonen Esa
Published: April 2018

Background

Clozapine impairs gastrointestinal motility owing to its anticholinergic and antiserotonergic properties. This commonly leads to constipation and potentially to more severe complications such as bowel obstruction and ischemia. The aim of this study was to determine whether genetic variations in the genes encoding muscarinic and serotonergic receptors (CHRM2, CHRM3, HTR2, HTR3, HTR4, and HTR7) explain the variations in incidence of constipation and anticholinergic symptoms during clozapine treatment. Genes associated with opiate-induced constipation were also included in this analysis (TPH1, OPRM1, ABCB1, and COMT).

Procedures

Blood samples from 176 clozapine-treated, Finnish, white patients with schizophrenia were genotyped. Constipation and anticholinergic symptoms were rated using the Liverpool University Neuroleptic Side Effect Rating Scale self-report questionnaire. In total, 192 single-nucleotide polymorphisms (SNPs) were detected and grouped to formulate a weighted genetic-risk score (GRS).

Results

No significant associations between individual SNPs or GRSs and constipation or laxative use were observed. A GRS of 19 SNPs in CHRM2, CHRM3, HTR3C, HTR7, ABCB1, OPRM1, and TPH1 was associated with anticholinergic symptoms in a generalized linear univariate model, with body mass index, clozapine monotherapy, and GRS as explaining variables (permuted P = 0.014). Generalized linear univariate model analysis performed on the opiate-induced constipation–associated SNPs and a single CHRM3 SNP revealed an association between anticholinergic symptoms and a score of 8 SNPs (adjusted P = 0.038, permuted P = 0.002).

Conclusions

Two GRSs are able to predict the risk of anticholinergic symptoms in patients receiving clozapine and possibly an increased risk of gastrointestinal hypomotility.
A Comprehensive Onboarding and Orientation Plan for Neurocritical Care Advanced Practice Providers
Authors: Langley Tamra M. , Dority Jeremy , Fraser Justin F. , Hatton Kevin W.
Published: April 2018

Background: As the role of advanced practice providers (APPs) expands to include increasingly complex patient care within the intensive care unit, the educational needs of these providers must also be expanded. An onboarding process was designed for APPs in the neurocritical care service line. Methods: Onboarding for new APPs revolved around 5 specific areas: candidate selection, proctor assignment, 3-phased orientation process, remediation, and mentorship. To ensure effective training for APPs, using the most time-conscious approach, the backbone of the process is a structured curriculum. This was developed and integrated within the standard orientation and onboarding process. The curriculum design incorporated measurable learning goals, objective assessments of phased goal achievements, and opportunities for remediation. Results: The neurocritical care service implemented an onboarding process in 2014. Four APPs (3 nurse practitioners and 1 physician assistant) were employed by the department before the implementation of the orientation program. The length of employment ranged from 1 to 4 years. Lack of clinical knowledge and/or sufficient training was cited as reasons for departure from the position in 2 of the 4 APPs, as either self-expression or peer evaluation. Since implementation of this program, 12 APPs have completed the program, of which 10 remain within the division, creating an 83% retention rate. Discussion: The onboarding process, including a 3-phased, structured orientation plan for neurocritical care, has increased APP retention since its implementation. The educational model, along with proctoring and mentorship, has improved clinical knowledge and increased nurse practitioner retention. A larger-scale study would help to support the validity of this onboarding process.
“Immune” Thrombocytopenia as Key Feature of a Novel ADA2 Deficiency Variant: Implication on Differential Diagnostics of ITP in Children
Authors: Sundin Mikael , Marits Per , Nierkens Stefan , Kolios Antonios G.A. , Nilsson Jakob
Published: April 2018

Thrombocytopenia presenting during early childhood is most commonly diagnosed as immune/idiopathic thrombocytopenic purpura (ITP), where the antibody-mediated destruction of thrombocytes is often transient. If treatment is indicated, the majority of patients respond to immune-modulation by intravenous immunoglobulin G infusion or systemic corticosteroids. Differential diagnoses to childhood ITP includes thrombocytopenia due to infections, drugs, rheumatologic conditions, immune dysregulation, and inherited bone marrow failures, for example, congenital amegakaryocytic thrombocytopenia. Isolated thrombocytopenia in an otherwise healthy appearing child that recurs after therapy and/or persists suggest a differential diagnosis rather than ITP. We present a case of symptomatic thrombocytopenia in a 2-year-old girl associated with adenosine deaminase deficiency.
A Case of Ataxia-telangiectasia Presented With Hemophagocytic Syndrome
Authors: Celiksoy Mehmet H. , Ozyavuz Cubuk Pelin , Guner Sukru N. , Yildiran Alisan
Published: April 2018

Ataxia-telangiectasia (A-T) is a multisystem disease caused by a genetic defect located on the long arm of chromosome 11 (11p22-23). The gene defect results in the loss of A-T–mutated protein, subsequently leading to unrepaired DNA fractures and defects in the signal transduction pathway. As a result, characteristic findings arise, including recurrent sinopulmonary infections, hypersensitivity against ionized radiation with the tendency to develop cancer related to progressive cerebellar ataxia, pathognomonic oculocutaneous telangiectasias, varying degrees of humoral and cellular immunodeficiency, and infertility. This case report presents a 3-year-old male patient with A-T who developed hemophagocytic syndrome. To the best of our knowledge, no such case has been previously reported.
Hepatitis-associated Aplastic Anemia Treated Successfully With Antithymocyte Globulin
Authors: Ji Hongyan , Chen Li , Sun Xiaojun , Li Xiuli , Chen Wei , Zhao Ping , Wang Yulin
Published: April 2018

Hepatitis-associated aplastic anemia (HAAA) is a variant of acquired aplastic anemia in which bone marrow failure follows the development of an acute episode of seronegative hepatitis. HAAA occurs most frequently in male children and is lethal if left untreated. Antilymphocyte globulin, antithymocyte globulin, and allogeneic bone marrow transplantation have been used in the treatment of this disease. In this work, we report the case of a 3-year-old boy with HAAA treated successfully with immunosuppressive therapy.
Predictive Histologic Factors in Carcinosarcomas of the Uterus: A Multi-institutional Study
Authors: Abdulfatah Eman , Lordello Leonardo , Khurram Muhammad , Van de Vijver Koen , Alosh Baraa , Bandyopadhyay Sudeshna , Oliva Esther , Ali-Fehmi Rouba
Published: April 2018

Uterine carcinosarcomas are rare aggressive biphasic neoplasms. Because of its rarity, limited data are available on potential prognostic parameters. While several studies support that carcinomatous components predict outcomes, others do not. In this study, we evaluated the clinical and histopathologic features of 196 uterine carcinosarcomas to identify potential prognostic factors. Patients’ ages ranged from 34 to 95 yr (median, 68 yr). Seventy-three (38%) patients experienced tumor recurrence during follow-up. Tumors ≥5 cm, outer half myometrial invasion, lymphovascular invasion, lymph node metastasis, advanced stage (International Federation of Gynecology and Obstetrics stages III–IV), sarcomatous component on recurrence, sarcoma dominance, and positive cytology were significantly associated with shorter disease-free interval (P<0.05). In addition, serous histology and rhabdomyoblastic differentiation was significantly associated with worse 3-yr overall survival. Our data supports that both carcinomatous and sarcomatous components play a role in tumor progression and survival of uterine carcinosarcoma patients, suggesting their equal importance in guiding management decisions.
Radiation-associated Angiosarcoma Mimicking Fallopian Tube High-grade Serous Carcinoma in a Woman With De Novo Li-Fraumeni Syndrome
Authors: Crafton Sarah M. , Senter-Jamieson Leigha , Chen James L. , Copeland Larry J. , Suarez Adrian A.
Published: April 2018

We present a case study of a woman with history of rectal adenocarcinoma, and a new diagnosis of radiation-associated angiosarcoma mimicking fallopian tube high-grade serous carcinoma who was subsequently found to have de novo Li-Fraumeni syndrome. Our objective is to highlight angiosarcoma as a potential pitfall in the diagnosis of high-grade serous carcinoma.
Electronic Health Records in Simulation Education
Authors: Wilbanks Bryan A. , Watts Penni I. , Epps Chad A.
Published: April 2018

Summary Statement

During the last decade, the use of electronic health records (EHRs) in clinical settings has risen sharply. Many clinical education programs have not incorporated the use of electronic documentation into their curriculum. It is important to incorporate technologies that will be used in real-world settings into educational clinical simulations to better prepare students for clinical practice and promote patient safety. Electronic documentation can be harder to teach to students because it requires a more in-depth orientation on how to use the electronic documentation system and because health care organizations often give students limited or no access to the documentation system. This review will include a discussion on the benefits and disadvantages of using educational EHRs, barriers and facilitators to implementing educational EHRs, and best practices for incorporating educational EHRs into current educational curriculums.
Double trouble: modelling the impact of low risk perception and high-risk sexual behaviour on chlamydia transmission
Authors: van Wees Daphne A. , den Daas Chantal , Kretzschmar Mirjam E. E. , Heijne Janneke C. M.
Published: April 2018

Risk perception plays an important role in testing behaviour for sexually transmitted infections, but is rarely included in mathematical models exploring the impact of testing. We explored the impact of incorporating sexual behaviour (SB), risk perception (RP) and differential testing uptake in SB–RP groups on prevalence, using chlamydia as an example. We developed a pair model with a susceptible–infected–susceptible structure representing heterosexuals aged 16–26 years. The effect of testing on chlamydia prevalence was compared between a model with only SB (SB model) and a model with SB and RP (SB–RP model). In the SB–RP model, a scenario without differential testing uptake in SB–RP groups was compared to scenarios with differential testing uptake in SB–RP groups. Introducing testing into the SB–RP model resulted in a slightly smaller reduction in chlamydia prevalence (−38.0%) as compared to the SB model (−40.4%). In the SB–RP model, the scenario without differential testing uptake in SB–RP groups overestimated the reduction in chlamydia prevalence (with 4.8%), especially in the group with high SB and low RP (19.8%). We conclude that mathematical models incorporating RP and differential testing uptake in SB–RP groups improve the impact assessment of testing and treatment on chlamydia prevalence.
Theoretical investigation of Banert cascade reaction
Authors: Bhattacharyya S. , Hatua K.
Published: April 2018

Computational inside of Banert cascade reaction for triazole formation is studied with B3LYP/6-31G(d,p) level of theory. The reaction proceeds mainly by SN2 initial chloride displacement rather than SN2′-type attack. Furthermore, according to the rate of reaction calculation, SN2 displacement is much faster than SN2′ displacement in the order of 8. The [3,3]-sigmatropic rearrangement for the conversion of propargyl azide into triazafulvene has been proved as the rate-determining step having highest activation energy parameter. Solvent effect on total course of reaction has been found negligible. Furthermore, effects of different density functional theory functionals and functional groups on activation energies of [3,3]-sigmatropic rearrangement of propargyl azide were also studied. BHHLYP,
ω
B97XD, M062X and BMK calculated Δ
G
‡
are consistent with B3LYP.
Influence of high altitude on the burning behaviour of typical combustibles and the related responses of smoke detectors in compartments
Authors: Tu Ran , Zeng Yi , Fang Jun , Zhang Yong-Ming
Published: April 2018

The effect of altitude on typical combustible burning and related smoke detector response signals was investigated by comparison experiments at altitudes of 40 m and 3650 m based on EN54 standard tests. Point-type light scattering photoelectric smoke detectors and ionization smoke detectors were used for four kinds of EN54 fire tests, including two kinds of smouldering fires with wood (test fire no. 2 in EN54 standard or TF2) and cotton (TF3), and two kinds of flaming fires with polyurethane (TF4) and
n
-heptane (TF5). First, the influence of altitude or ambient pressure on mass loss for smouldering combustion (TF2 or TF3) was insignificant, while a significant decrease in the mass burning rate was found for flaming tests (TF4 and TF5) as reported in our previous studies. Second, for photoelectric smoke detectors in flaming fire tests, the effect of altitude was similar to that of the burning rate, whereas for the ionization smoke detectors, the response signal at high altitudes was shown to be ‘enhanced’ by the detection principle of the ionization chamber, leading to an even larger value than at normal altitude for smouldering conditions. Third, to provide a reference for smoke detector design in high-altitude areas, the differences between signal speed in rising and peak values at two locations are discussed. Also, relationship between ion chamber signals and smoke optical densities are presented by utilization of an ionization smoke detector and smoke concentration meter. Moreover, a hierarchical diagram is illustrated to provide a better understanding of the effects of altitude on combustible burning behaviour and the mechanisms of detector response.
Frequency dependence shapes the adaptive landscape of imperfect Batesian mimicry
Authors: Finkbeiner Susan D. , Salazar Patricio A. , Nogales Sofía , Rush Cassidi E. , Briscoe Adriana D. , Hill Ryan I. , Kronforst Marcus R. , Willmott Keith R. , Mullen Sean P.
Published: April 2018

Despite more than a century of biological research on the evolution and maintenance of mimetic signals, the relative frequencies of models and mimics necessary to establish and maintain Batesian mimicry in natural populations remain understudied. Here we investigate the frequency-dependent dynamics of imperfect Batesian mimicry, using predation experiments involving artificial butterfly models. We use two geographically distinct populations ofAdelphabutterflies that vary in their relative frequencies of a putatively defended model (Adelpha iphiclus) and Batesian mimic (Adelpha serpa). We found that in Costa Rica, where both species share similar abundances, Batesian mimicry breaks down, and predators more readily attack artificial butterfly models of the presumed mimic,A. serpa. By contrast, in Ecuador, whereA. iphiclus(model) is significantly more abundant thanA. serpa(mimic), both species are equally protected from predation. Our results provide compelling experimental evidence that imperfect Batesian mimicry is frequency-dependent on the relative abundance of models and mimics in natural populations, and contribute to the growing body of evidence that complex dynamics, such as seasonality or the availability of alternative prey, influence the evolution of mimetic traits.
The role of ecological factors in shaping bat cone opsin evolution
Authors: Gutierrez Eduardo de A. , Schott Ryan K. , Preston Matthew W. , Loureiro Lívia O. , Lim Burton K. , Chang Belinda S. W.
Published: April 2018

Bats represent one of the largest and most striking nocturnal mammalian radiations, exhibiting many visual system specializations for performance in light-limited environments. Despite representing the greatest ecological diversity and species richness in Chiroptera, Neotropical lineages have been undersampled in molecular studies, limiting the potential for identifying signatures of selection on visual genes associated with differences in bat ecology. Here, we investigated how diverse ecological pressures mediate long-term shifts in selection upon long-wavelength (Lws) and short-wavelength (Sws1) opsins, photosensitive cone pigments that form the basis of colour vision in most mammals, including bats. We used codon-based likelihood clade models to test whether ecological variables associated with reliance on visual information (e.g. echolocation ability and diet) or exposure to varying light environments (e.g. roosting behaviour and foraging habitat) mediated shifts in evolutionary rates in bat cone opsin genes. Using additional cone opsin sequences from newly sequenced eye transcriptomes of six Neotropical bat species, we found significant evidence for different ecological pressures influencing the evolution of the cone opsins. WhileLwsis evolving under significantly lower constraint in highly specialized high-duty cycle echolocating lineages, which have enhanced sonar ability to detect and track targets, variation inSws1constraint was significantly associated with foraging habitat, exhibiting elevated rates of evolution in species that forage among vegetation. This suggests that increased reliance on echolocation as well as the spectral environment experienced by foraging bats may differentially influence the evolution of different cone opsins. Our study demonstrates that different ecological variables may underlie contrasting evolutionary patterns in bat visual opsins, and highlights the suitability of clade models for testing ecological hypotheses of visual evolution.
Computer simulations show that Neanderthal facial morphology represents adaptation to cold and high energy demands, but not heavy biting
Authors: Wroe Stephen , Parr William C. H. , Ledogar Justin A. , Bourke Jason , Evans Samuel P. , Fiorenza Luca , Benazzi Stefano , Hublin Jean-Jacques , Stringer Chris , Kullmer Ottmar , Curry Michael , Rae Todd C. , Yokley Todd R.
Published: April 2018

Three adaptive hypotheses have been forwarded to explain the distinctive Neanderthal face: (i) an improved ability to accommodate high anterior bite forces, (ii) more effective conditioning of cold and/or dry air and, (iii) adaptation to facilitate greater ventilatory demands. We test these hypotheses using three-dimensional models of Neanderthals, modern humans, and a close outgroup (Homo heidelbergensis), applying finite-element analysis (FEA) and computational fluid dynamics (CFD). This is the most comprehensive application of either approach applied to date and the first to include both. FEA reveals few differences betweenH. heidelbergensis, modern humans, and Neanderthals in their capacities to sustain high anterior tooth loadings. CFD shows that the nasal cavities of Neanderthals and especially modern humans condition air more efficiently than does that ofH. heidelbergensis, suggesting that both evolved to better withstand cold and/or dry climates than less derivedHomo. We further find that Neanderthals could move considerably more air through the nasal pathway than couldH. heidelbergensisor modern humans, consistent with the propositions that, relative to our outgroupHomo, Neanderthal facial morphology evolved to reflect improved capacities to better condition cold, dry air, and, to move greater air volumes in response to higher energetic requirements.
Distinguishing cells from empty droplets in droplet-based single-cell RNA sequencing data
Authors: Lun Aaron T. L. , Riesenfeld Samantha , Andrews Tallulah ,   The Phuong Dao, Gomes Tomas ,   participants in the 1st Human Cell Atlas Jamboree, Marioni John C.
Published: April 2018

Droplet-based single-cell RNA sequencing protocols have dramatically increased the throughput and efficiency of single-cell transcriptomics studies. A key computational challenge when processing these data is to distinguish libraries for real cells from empty droplets. Existing methods for cell calling set a minimum threshold on the total unique molecular identifier (UMI) count for each library, which indiscriminately discards cell libraries with low UMI counts. Here, we describe a new statistical method for calling cells from droplet-based data, based on detecting significant deviations from the expression profile of the ambient solution. Using simulations, we demonstrate that our method has greater power than existing approaches for detecting cell libraries with low UMI counts, while controlling the false discovery rate among detected cells. We also apply our method to real data, where we show that the use of our method results in the retention of distinct cell types that would otherwise have been discarded.