bluuebunny/crossref_metadata_2025 huggingface dataset:
Insight into the interface between Fe3O4 (001) surface and water overlayers through multiscale molecular dynamics simulations
Authors: Liu Hongsheng , Bianchetti Enrico , Siani Paulo , Di Valentin Cristiana
Published: March 2020

In this work, we investigate the Fe3O4 (001) surface/water interface by combining several theoretical approaches, ranging from a hybrid functional method (HSE06) to density-functional tight-binding (DFTB) to molecular mechanics (MM). First, we assess the accuracy of the DFTB method to correctly reproduce HSE06 results on structural details and energetics and available experimental data for adsorption of isolated water, dimers, and trimers up to a water monolayer. Second, we build two possible configurations of a second and a third overlayer and perform molecular dynamics simulations with DFTB, monitoring the water orientation, the H-bond network, and the ordered water structure formation. To make our models more realistic, we then build a 12 nm-thick water multilayer on top of the Fe3O4 (001) surface slab model, which we investigate through MM-molecular dynamics (MD). The water layer structuring, revealed by the analysis of the atomic positions from a long MM-MD run for this large MM model, extends up to about 6–7 Å and nicely compares with that observed for a water trilayer model. However, MM and DFTB MD simulations show some discrepancy due to the poor description of the Fe⋯OH2 distance in MM that calls for further work in the parameterization of the model.
Theoretical calculations of the mean escape depth of secondary electron emission from compound semiconductor materials
Authors: Hussain A. , Yang L. H. , Zou Y. B. , Mao S. F. , Da B. , Li H. M. , Ding Z. J.
Published: March 2020

We have performed a systematic Monte Carlo simulation of primary and secondary electron trajectories to predicate the mean escape depth of secondary electron emission for six compound semiconductors, i.e., TiN, VN, GaAs, InAs, InSb, and PbS. Mott's cross section is used for the description of electron elastic scattering in the simulation model, and the full-Penn's dielectric function approach is adopted for the modeling of electron inelastic scattering, where the energy loss function obtained with the optical data is contributed from phonon excitation, interband transition of the loosely bound valance electrons, and inner-shell electron excitations. We have calculated the excitation depth distribution function, emission depth distribution function, and their combining effect in probability depth distribution function at different primary energies for the excited and emitted secondary electrons in these materials. The calculation leads to the primary energy dependence of mean escape depth whose values are found in the range of 0.4–1.4 nm for these materials.
Benchmarking of a distributed-memory, high-order discontinuous finite element flow solver on a shared-memory parallel architecture
Authors: Ali Amjad , Farooq Hamayun , Shahzadi Gullnaz , Umar Muhammad , Syed Khalid Saifullah
Published: March 2020

High-order numerical schemes implemented on high-performance parallel computers are of special interest for contemporary numerical simulations, especially in computational fluid dynamics. In this study, first, a high-order parallel flow solver is presented for some test cases of aerodynamic simulations. The flow solver is based on a discontinuous Galerkin finite element method on arbitrary grids with different orders of polynomial approximation for solving the compressible flow model. Second, the distributed-memory parallel implementation of the flow solver is benchmarked on a shared-memory multicore system. A distributed-memory parallel application can be executed on shared-memory architectures by assuming that each of the parallel processes assumes separate memory address space, although all are present in a common memory bank. This approach can offer an effective measure to address several issues related to limited resources, especially for uninterrupted electric supply. The scalability of the parallel application is analyzed by varying the problem workload per process for the test cases. For some test cases in the present study, over 90% parallel efficiency per process is also observed. The performance of the distributed-memory program on the shared-memory architecture establishes suitability and robustness of the approach for small to medium scale problems, at least.
Building blocks are synthesized on demand during the yeast cell cycle
Authors: Campbell Kate , Westholm Jakub , Kasvandik Sergo , Di Bartolomeo Francesca , Mormino Maurizio , Nielsen Jens
Published: March 2020

For cells to replicate, a sufficient supply of biosynthetic precursors is needed, necessitating the concerted action of metabolism and protein synthesis during progressive phases of cell division. A global understanding of which biosynthetic processes are involved and how they are temporally regulated during replication is, however, currently lacking. Here, quantitative multiomics analysis is used to generate a holistic view of the eukaryal cell cycle, using the budding yeast
Saccharomyces cerevisiae
. Protein synthesis and central carbon pathways such as glycolysis and amino acid metabolism are shown to synchronize their respective abundance profiles with division, with pathway-specific changes in metabolite abundance also being reflected by a relative increase in mitochondrial volume, as shown by quantitative fluorescence microscopy. These results show biosynthetic precursor production to be temporally regulated to meet phase-specific demands of eukaryal cell division.
Climate change perception by adolescents: reflections on sustainable lifestyle, local impacts and optimism bias (Percepción del cambio climático en adolescentes. Reflexiones sobre los estilos de vida sostenibles, el impacto local y el sesgo optimista)
Authors: Barros Hellen , Pinheiro José
Published: March 2020

The intensification of climate change (CC) is influenced by human actions, adding relevance to psychological studies about the matter. This study investigated the perception of CC by adolescents and its possible relationship to sustainable lifestyle indicators (SLIs). A multi-method exploratory approach to this subject was divided into two stages: a questionnaire applied to 484 students and subsequent focus groups with some of those students. The results revealed that: causes and consequences of CC were by far the most mentioned constituents of its definition; participants were able to describe local implications of CC; and focus groups offered an opportunity for deepening and strengthening their responses to the questionnaire. A spatial optimism bias was identified: adolescents expressed more concern about the world situation as compared to that of their own city. The study indicates possible pathways towards the engagement of adolescents in climate change mitigation, as in the case of environmental care practices and connectedness to nature, significantly associated with aspects of CC perception.
Anomalous thickness-dependent electrical conductivity in van der Waals layered transition metal halide, Nb3Cl8
Authors: Yoon Jiho , Lesne Edouard , Sklarek Kornelia , Sheckelton John , Pasco Chris , Parkin Stuart S P , McQueen Tyrel M , Ali Mazhar N
Published: March 2020

Understanding the electronic transport properties of layered, van der Waals transition metal halides (TMHs) and chalcogenides is a highly active research topic today. Of particular interest is the evolution of those properties with changing thickness as the 2D limit is approached. Here, we present the electrical conductivity of exfoliated single crystals of the TMH, cluster magnet, Nb3Cl8, over a wide range of thicknesses both with and without hexagonal boron nitride (hBN) encapsulation. The conductivity is found to increase by more than three orders of magnitude when the thickness is decreased from 280 µm to 5 nm, at 300 K. At low temperatures and below ∼50 nm, the conductance becomes thickness independent, implying surface conduction is dominating. Temperature dependent conductivity measurements indicate Nb3Cl8 is an insulator, however, the effective activation energy decreases from a bulk value of 310 meV to 140 meV by 5 nm. X-ray photoelectron spectroscopy (XPS) shows mild surface oxidation in devices without hBN capping, however, no significant difference in transport is observed when compared to the capped devices, implying the thickness dependent transport behavior is intrinsic to the material. A conduction mechanism comprised of a higher conductivity surface channel in parallel with a lower conductivity interlayer channel is discussed.
New techniques for a measurement of the electron’s electric dipole moment
Authors: Ho C J , Devlin J A , Rabey I M , Yzombard P , Lim J , Wright S C , Fitch N J , Hinds E A , Tarbutt M R , Sauer B E
Published: March 2020

The electric dipole moment of the electron (eEDM) can be measured with high precision using heavy polar molecules. In this paper, we report on a series of new techniques that have improved the statistical sensitivity of the YbF eEDM experiment. We increase the number of molecules participating in the experiment by an order of magnitude using a carefully designed optical pumping scheme. We also increase the detection efficiency of these molecules by another order of magnitude using an optical cycling scheme. In addition, we show how to destabilise dark states and reduce backgrounds that otherwise limit the efficiency of these techniques. Together, these improvements allow us to demonstrate a statistical sensitivity of 1.8 × 10−28 e cm after one day of measurement, which is 1.2 times the shot-noise limit. The techniques presented here are applicable to other high-precision measurements using molecules.
Photocurrent improvement of an ultra-thin silicon solar cell using the localized surface plasmonic effect of clustering nanoparticles
Authors: Sobhani F , Heidarzadeh H , Bahador H
Published: March 2020

The cluster-shaped plasmonic nanostructures are used to manage the incident light inside an ultra-thin silicon solar cell. Here we simulate spherical, conical, pyramidal, and cylindrical nanoparticles in a form of a cluster at the rear side of a thin silicon cell, using the finite difference time domain (FDTD) method. By calculating the optical absorption and hence the photocurrent, it is shown that the clustering of nanoparticles significantly improves them. The photocurrent enhancement is the result of the plasmonic effects of clustering the nanoparticles. For comparison, first a cell with a single nanoparticle at the rear side is evaluated. Then four smaller nanoparticles are put around it to make a cluster. The photocurrents of 20.478 mA/cm2, 23.186 mA/cm2, 21.427 mA/cm2, and 21.243 mA/cm2 are obtained for the cells using clustering conical, spherical, pyramidal, cylindrical NPs at the backside, respectively. These values are 13.987 mA/cm2, 16.901 mA/cm2, 16.507 mA/cm2, 17.926 mA/cm2 for the cell with one conical, spherical, pyramidal, cylindrical NPs at the backside, respectively. Therefore, clustering can significantly improve the photocurrents. Finally, the distribution of the electric field and the generation rate for the proposed structures are calculated.
High-performance midwavelength infrared detectors based on InAsSb nBn design*
Authors: Zhang Xuan , Jia Qing-Xuan , Sun Ju , Jiang Dong-Wei , Wang Guo-Wei , Xu Ying-Qiang , Niu Zhi-Chuan
Published: March 2020

we report nBn photodetectors based on InAs0.91Sb0.09 with a 100% cut-off wavelength of 4.75 μm at 300 K. The band of an nBn detector is similar to that of a standard pin detector, but there is special wide bandgap AlAs0.08Sb0.92 barrier layer in the nBn detector, in which the depletion region of nBn detector exists. The nBn design has many advantages, such as low dark current and high quantum efficiency, because the nBn design can suppress the generation–recombination (GR) current that is the main composition of standard pin detector dark current. The constant slope of the Arrhenius plot of J
0–1/T indicates the absence of the generation–recombination dark current. We fabricate an nBn detector with a quantum efficiency (QE) maximum of ∼ 60% under −0.2-V bias voltage. The InAsSb nBn detectors may be a competitive candidate for midwavelength infrared detector.
Implications of non-linearities between cumulative CO2 emissions and CO2-induced warming for assessing the remaining carbon budget
Authors: Nicholls Z R J , Gieseke R , Lewis J , Nauels A , Meinshausen M
Published: March 2020

To determine the remaining carbon budget, a new framework was introduced in the Intergovernmental Panel on Climate Change’s Special Report on Global Warming of 1.5 °C (SR1.5). We refer to this as a ‘segmented’ framework because it considers the various components of the carbon budget derivation independently from one another. Whilst implementing this segmented framework, in SR1.5 the assumption was that there is a strictly linear relationship between cumulative CO2 emissions and CO2-induced warming i.e. the TCRE is constant and can be applied to a range of emissions scenarios. Here we test whether such an approach is able to replicate results from model simulations that take the climate system’s internal feedbacks and non-linearities into account. Within our modelling framework, following the SR1.5’s choices leads to smaller carbon budgets than using simulations with interacting climate components. For 1.5 °C and 2 °C warming targets, the differences are 50 GtCO2 (or 10%) and 260 GtCO2 (or 17%), respectively. However, by relaxing the assumption of strict linearity, we find that this difference can be reduced to around 0 GtCO2 for 1.5 °C of warming and 80 GtCO2 (or 5%) for 2.0 °C of warming (for middle of the range estimates of the carbon cycle and warming response to anthropogenic emissions). We propose an updated implementation of the segmented framework that allows for the consideration of non-linearities between cumulative CO2 emissions and CO2-induced warming.
SBA-15 synthesis from sodium silicate prepared with sand and sodium hydroxide
Authors: Lázaro A L , Rodríguez-Valadez Francisco J , López J J Machorro , Espejel-Ayala F
Published: March 2020

In the industry, sodium carbonate is used to prepare sodium silicate; however, this process generates great volumes of CO2. In this work, sodium hydroxide has been proposed to prepare sodium silicate using natural sand. Two experimental variables were considered, sodium hydroxide concentration and temperature to prepare sodium silicate. Results show the formation of sodium silicate with a NaOH:sand ratio = 1.1 at 550 °C. Moreover, an economical revision was achieved to compare costs of sodium silicate with sodium hydroxide and sodium carbonate. The use of sodium hydroxide permits to decrease CO2 emissions generated in the decomposition of sodium carbonate. Additionally, the sodium silicate prepared herein was used to synthesize a zeolite type material, SBA-15. SBA-15 obtained has similar characteristics than the commercial mesoporous material. The use of sodium silicate prepared with non-pure sand for preparing mesoporous materials is an economical and friendly environmental alternative.
Optical trapping and orientation-resolved spectroscopy of europium-doped nanorods
Authors: Kumar Aashutosh , Kim Jeongmo , Lahlil Khalid , Julie Gwénaëlle , Nic Chormaic Síle , Kim Jongwook , Gacoin Thierry , Fick Jochen
Published: March 2020

Europium-doped NaYF4 nanorods with a high aspect ratio are optically trapped using a single fibre tip optical tweezers. Three distinct trapping positions of the nanorods are observed: in contact with the fibre tip, close to the tip and 5 µm from the tip end. The direction and polarisation-dependent Eu3 +  photoluminescence is investigated by recording the emission parallel and perpendicular to the nanorod long axis through the trapping fibre and the microscope objective, respectively. These spectroscopic measurements permit an unambiguous determination of the nanorod orientation.
Fracture behavior in battery materials
Authors: Li Ping , Zhao Yibo , Shen Yongxing , Bo Shou-Hang
Published: March 2020

The fracture of battery materials is one of the main causes of battery degradation. This issue is further amplified in emerging solid-state batteries, where the more robust interface between the liquid electrolyte and solid electrode in conventional batteries is replaced by a brittle solid–solid interface. In this review, we summarize the observed fracture behavior in battery materials, the origin of fracture initiation and propagation, as well as the factors that affect the fracture processes of battery materials. Both experimental and modeling analyses are presented. Finally, future developments regarding the quantification of fracture, the interplay of chemo-mechanical factors, and battery lifespan design are discussed along with a proposed theoretical framework, in analogy to fatigue damage, to better understand battery material fracture upon extended cycling.
4. The Second World War
Authors: Ledwidge Frank
Published: March 2020

‘The Second World War: air operations in the West’ considers the air capabilities of the main actors of the Second World War including the Polish air force, the German Luftwaffe, the Soviet air force, Britain’s Royal Air Force, and the US Army Air Corps. It discusses the strategies employed by the different forces during the various stages of the war, including securing the control of the air during the Battle of Britain in 1940, which demonstrated that a defensive air campaign could have strategic and political effect. The improving technology throughout the war is discussed along with role of air power at sea, and the results and controversy of the bombing war in Europe.
3. Paramilitarism
Authors: Mulholland Marc
Published: March 2020

The culture of paramilitarism in Ireland was undiminished by the world wars. The Ulster Volunteer Force became a founding myth for Northern Ireland with the annual Orange parades being a quasi-formal institution of the state. After the 1916 Rebellion, the Irish Volunteers evolved into the Irish Republican Army (IRA). ‘Paramilitarism’ discusses the resurgence of both loyalism and republicanism in the 1960s and the rationale behind the violence on both sides. It describes how paramilitarism became consolidated as a ‘way of life’; the 1976 Peace People marches; the IRA ‘Long War’ strategy; the hunger strikes; the impact of the Anglo-Irish Agreement; the rise of Sinn Féin; and the peace process from the paramilitary perspective.
Systems Biology: A Very Short Introduction
Authors: Voit Eberhard O.
Published: March 2020

Systems biology came about as growing numbers of scientists and engineers from different fields created experimental methods and algorithms that supported the analysis of very large quantities of biological data. Systems Biology: A Very Short IntroductionÂ outlines the exciting processes and possibilities in this new field. It describes how modern biology enabled us to learn how intricately the expression of every gene is controlled, how signalling systems keep organisms running smoothly, how complicated even the simplest cells are, and how computational methods may help us understand these complex systems of life. It explores what this field is about, why it is needed, and how it will affect our understanding of life, particularly in the areas of personalized medicine, drug development, food and energy production, and sustainable stewardship of our environments.
3. The —omics revolution
Authors: Voit Eberhard O.
Published: March 2020

In the past, experiments were time consuming and expensive, and data were therefore often scarce. The so-called —omics revolution has changed this situation to a point where we often have so many data that we cannot make sense of them and need to resort to sophisticated computing methods. ‘The —omics revolution’ explains how this shift has changed how we perform experiments and think about science. The —omics revolution—with fields of study such as genomics and proteomics—has not only generated huge datasets, it has turned the tried-and-true scientific method on its head. The central position of a strong hypothesis has all but vanished, and the new mindset is exploratory data analysis.
7. The lawless pursuit of biological systems
Authors: Voit Eberhard O.
Published: March 2020

The laws of physics are a prerequisite for us to make reliable predictions regarding our surroundings. By extension, making reliable predictions in biology requires laws of biology. The problem is that such laws are almost non-existent, because biological systems are hugely complex and diverse. As a consequence, it is difficult to make true statements covering all organisms on Earth—or even large classes of organisms. This difficulty translates directly into the challenge of identifying rules that govern biological systems. What would such biological rules or laws even look like? ‘The lawless pursuit of biological systems’ considers the future of systems biology and discusses how it might evolve as it matures as a field of investigation.
6. Intersectionality and ‘implicit’ or ‘unconscious’ bias
Authors: Rattansi Ali
Published: March 2020

Race, class, and gender were often referred to as the ‘holy trinity’ of sociological analysis in the 1980s, because it was becoming clear that racial inequalities needed to be considered in relation to both class and gender. This mantra has led to a whole new field of research—‘intersectionality’ studies—which now includes within its research framework an understanding that age, disability, and citizenship also have differential impacts on majority and minority communities and individuals. ‘Intersectionality and “implicit” or “unconscious” bias’ provides examples of everyday racism and racial harassment and explains how research evidence shows that diversity training is highly ineffective as a tool for combating racial prejudice.
TwisTranscripT: stochastic simulation of the transcription-supercoiling coupling
Authors: El Houdaigui Bilal , Meyer Sam
Published: March 2020

Transcription and DNA supercoiling are involved in a complex, dynamical and non-linear coupling that results from the basal interaction between DNA and RNA polymerase. We present the first software to simulate this coupling, applicable to a wide range of bacterial organisms. TwisTranscripT allows quantifying its contribution in global transcriptional regulation, and provides a mechanistic basis for the widely observed, evolutionarily conserved and currently unexplained co-regulation of adjacent operons that might play an important role in genome evolution.

Availability and implementation

TwisTranscripT is freely available at https://github.com/sammeyer2017/TwisTranscripT. It is implemented in Python3 and supported on MacOS X, Linux and Windows.
Fine-mapping within eQTL credible intervals by expression CROP-seq
Authors: Pan Yidan , Tian Ruoyu , Lee Ciaran , Bao Gang , Gibson Greg
Published: March 2020

The majority of genome-wide association study (GWAS)-identified SNPs are located in noncoding regions of genes and are likely to influence disease risk and phenotypes by affecting gene expression. Since credible intervals responsible for genome-wide associations typically consist of ≥100 variants with similar statistical support, experimental methods are needed to fine map causal variants. We report here a moderate-throughput approach to identifying regulatory GWAS variants, expression CROP-seq, which consists of multiplex CRISPR-Cas9 genome editing combined with single-cell RNAseq to measure perturbation in transcript abundance. Mutations were induced in the HL60/S4 myeloid cell line nearby 57 SNPs in three genes, two of which, rs2251039 and rs35675666, significantly altered CISD1 and PARK7 expression, respectively, with strong replication and validation in single-cell clones. The sites overlap with chromatin accessibility peaks and define causal variants for inflammatory bowel disease at the two loci. This relatively inexpensive approach should be scalable for broad surveys and is also implementable for the fine mapping of individual genes.
Simulation of the Clinical and Pathological Manifestations of Coronavirus Disease 2019 (COVID-19) in a Golden Syrian Hamster Model: Implications for Disease Pathogenesis and Transmissibility
Authors: Chan Jasper Fuk-Woo , Zhang Anna Jinxia , Yuan Shuofeng , Poon Vincent Kwok-Man , Chan Chris Chung-Sing , Lee Andrew Chak-Yiu , Chan Wan-Mui , Fan Zhimeng , Tsoi Hoi-Wah , Wen Lei , Liang Ronghui , Cao Jianli , Chen Yanxia , Tang Kaiming , Luo Cuiting , Cai Jian-Piao , Kok Kin-Hang , Chu Hin , Chan Kwok-Hung , Sridhar Siddharth , Chen Zhiwei , Chen Honglin , To Kelvin Kai-Wang , Yuen Kwok-Yung
Published: March 2020

Background

A physiological small-animal model that resembles COVID-19 with low mortality is lacking.

Methods

Molecular docking on the binding between angiotensin-converting enzyme 2 (ACE2) of common laboratory mammals and the receptor-binding domain of the surface spike protein of SARS-CoV-2 suggested that the golden Syrian hamster is an option. Virus challenge, contact transmission, and passive immunoprophylaxis studies were performed. Serial organ tissues and blood were harvested for histopathology, viral load and titer, chemokine/cytokine level, and neutralizing antibody titer.

Results

The Syrian hamster could be consistently infected by SARS-CoV-2. Maximal clinical signs of rapid breathing, weight loss, histopathological changes from the initial exudative phase of diffuse alveolar damage with extensive apoptosis to the later proliferative phase of tissue repair, airway and intestinal involvement with viral nucleocapsid protein expression, high lung viral load, and spleen and lymphoid atrophy associated with marked chemokine/cytokine activation were observed within the first week of virus challenge. The mean lung virus titer was between 105 and 107 TCID50/g. Challenged index hamsters consistently infected naive contact hamsters housed within the same cages, resulting in similar pathology but not weight loss. All infected hamsters recovered and developed mean serum neutralizing antibody titers ≥1:427 14 days postchallenge. Immunoprophylaxis with early convalescent serum achieved significant decrease in lung viral load but not in lung pathology. No consistent nonsynonymous adaptive mutation of the spike was found in viruses isolated from the infected hamsters.

Conclusions

Besides satisfying Koch’s postulates, this readily available hamster model is an important tool for studying transmission, pathogenesis, treatment, and vaccination against SARS-CoV-2.
Do athletes play by different rules? Obstructive coronary artery disease in asymptomatic competitive Masters athletes: a case series
Authors: McKinney James , Moulson Nathaniel , Morrison Barbara N , Phulka Jobanjit S , Yeung Phillip , Isserow Saul , Wood David A
Published: March 2020

Background

Both the age and number of endurance Masters athletes is increasing; this coincides with increasing cardiovascular risk. The vast majority of sports-related sudden cardiac deaths (SCDs) occur among athletes >35 years of age. Coronary artery disease (CAD) is the most common cause of SCD amongst Masters athletes.

Case summary

In our prospective screening trial, six asymptomatic Masters athletes with ischaemia on electrocardiogram exercise stress testing had their coronary anatomy defined either by cardiac computed tomography or coronary angiography. Three patients underwent coronary angiography, with fractional flow reserve (FFR) testing performed when indicated. Subsequent percutaneous revascularization was performed in one patient after a shared-decision making process involving the patient and the referring cardiologist. All six athletes identified with obstructive CAD were male. The mean age and Framingham risk score was 61.8 years (±9.5) and 22.7% (±6.1), respectively. The mean metabolic equivalent of task achieved was 14.4 (±3.8). All athletes were treated with optimal medical therapy as clinically indicated. No cardiac events occured in 4.3 years of follow-up.

Discussion

Guidelines recommend revascularization of Masters athletes to alleviate the ischaemic substrate despite a paucity of evidence that revascularization will translate into a reduction in myocardial infarct or sudden cardiac arrest/death. Herein, although a limited study population, we demonstrate a lack of clinical events after 4.3 years of follow-up whether or not revascularization was performed. A prospective multicentre registry for asymptomatic Masters athletes with documented obstructive CAD is needed to help establish the role of revascularization in this population.
The hidden skills of the cryoballoon: occlusion of cardiac perforation in a patient with persistent left superior vena cava—a case report
Authors: El Hamriti Mustapha , Bergau Leonard , Sommer Philipp , Sohns Christian
Published: March 2020

Background

Cardiac tamponade is one of the most serious complications when performing cardiac interventions. Although most of the patients can be treated effectively using pericardiocentesis, urgent surgery can be necessary in case of continuous bleeding and patients’ haemodynamic impairment.

Case summary

With this unique clinical case report we describe an acute endovascular occlusion of a cardiac perforation utilizing the inflated 28 mm cryoballon at the transseptal puncture site close to the superior part of the coronary sinus ostium in a patient with persistent left superior vena cava (PLSVC) and severe post-procedural tamponade. Prior to this maneuver, 1200 mL of haemorrhagic effusion has been aspirated. Forty-five minutes after cryoballoon-guided occlusion we deflated the balloon and no additional blood could be aspirated over the following 20 minutes.

Discussion

Cryoballon-guided occlusion of the perforation site saved the patient from immediate cardiac surgery and resulted in stable haemodynamic conditions. This bailout approach was transferred from coronary interventions where occlusion of a perforated vessel using balloon devices is a common technique to achieve acute hemostasis.
Evaluation of the MC-Media Pad® Rapid Aerobic Count Device for the Enumeration of Total Aerobic Counts in a Variety of Foods: Collaborative Study, First Action Official MethodSM 2019.02
Authors: Bastin Benjamin , Klass Nicole , Crowley Erin , Agin James , Lindhardt Charlotte , Chollet Renaud
Published: March 2020

Background

The MC-Media Pad® Rapid Aerobic Count (RAC) is a ready-to-use culture device combining a test pad coated with medium and water absorption polymers that are designed for the rapid quantification of total aerobic bacteria in food products.

Objective

The MC-Media Pad RAC was compared to the U.S. Department of Agriculture Food Safety and Inspection Service Microbiology Laboratory Guidebook, Chapter 3.02: Quantitative Analysis of Bacteria in Foods as Sanitary Indicators for raw ground pork and the Standard Methods for the Examination of Dairy Products, Chapter 6: Microbial Count Methods for yogurt drink.

Method

The candidate method was evaluated against the reference methods using a paired study design in a multi-collaborator study, following the current AOAC INTERNATIONAL Official Methods of AnalysisSM Appendix J guidelines. Three target contamination levels (low, medium, and high) were evaluated. MC-Media Pad RAC devices were enumerated after 24 and 48 h of incubation.

Results

Plate counts obtained by both methods were log10-transformed and the difference of means (including 95% confidence intervals), repeatability SD, and reproducibility SD were determined for each contamination level. All 95% confidence intervals for mean difference fell easily within ±0.10, the performance requirement being ±0.5.

Conclusion

The MC-Media Pad RAC (for both 24 and 48 h) and both reference methods for each contamination level were therefore shown to be equivalent, with 97.5% confidence.

Highlights

The new method offers a convenient alternative to the reference methods for detection of aerobic plate count in food products, yielding reliable and comparable results in 24 or 48 h compared to 48 h for the reference methods.
The prevalence of femoroacetabular impingement anatomy in Division 1 aquatic athletes who tread water
Authors: Langner Joanna L , Black Marianne S , MacKay James W , Hall Kimberly E , Safran Marc R , Kogan Feliks , Gold Garry E
Published: March 2020

Femoroacetabular impingement (FAI) is a disorder that causes hip pain and disability in young patients, particularly athletes. Increased stress on the hip during development has been associated with increased risk of cam morphology. The specific forces involved are unclear, but may be due to continued rotational motion, like the eggbeater kick. The goal of this prospective cohort study was to use magnetic resonance imaging (MRI) to identify the prevalence of FAI anatomy in athletes who tread water and compare it to the literature on other sports. With university IRB approval, 20 Division 1 water polo players and synchronized swimmers (15 female, 5 male), ages 18–23 years (mean age 20.7 ± 1.4), completed the 33-item International Hip Outcome Tool and underwent non-contrast MRI scans of both hips using a 3 Tesla scanner. Recruitment was based on sport, with both symptomatic and asymptomatic individuals included. Cam and pincer morphology were identified. The Wilcoxon Signed-Rank/Rank Sum tests were used to assess outcomes. Seventy per cent (14/20) of subjects reported pain in their hips yet only 15% (3/20) sought clinical evaluation. Cam morphology was present in 67.5% (27/40) of hips, while 22.5% (9/40) demonstrated pincer morphology. The prevalence of cam morphology in water polo players and synchronized swimmers is greater than that reported for the general population and at a similar level as some other sports. From a clinical perspective, acknowledgment of the high prevalence of cam morphology in water polo players and synchronized swimmers should be considered when these athletes present with hip pain.
Potato Psyllid (Hemiptera: Triozidae) Behavior on Three Potato Genotypes With Tolerance to ‘Candidatus Liberibacter solanacearum’
Authors: Fife Austin N , Cruzado Karin , Rashed Arash , Novy Richard G , Wenninger Erik J
Published: March 2020

The potato/tomato psyllid Bactericera cockerelli (Šulc) transmits ‘Candidatus Liberibacter solanacearum’ (Lso) (also known as ‘Candidatus Liberibacter psyllaurous’), the bacterium associated with zebra chip disease (ZC) in potato. When disease incidence is high, ZC causes large economic losses through reductions in potato yield and tuber quality. No commercial potato variety has been found totally resistant to the pathogen. We evaluated host acceptance behaviors using no-choice assays on three breeding clones derived from Solanum chacoense Bitter with putative tolerance to Lso and/or ZC as part of an effort to determine whether the disease tolerance observed in those breeding clones was related to effects on psyllid settling behavior. We also counted the number of eggs laid and nymphs hatched on the different genotypes to observe any differences in reproduction. The potato variety ‘Russet Burbank’ was used as a susceptible control. Probing frequency and female walking duration were greater on Russet Burbank than the other genotypes. Oviposition did not differ among genotypes. However, female psyllids on two of the Lso-tolerant genotypes displayed reduced fertility 18–24 d after confinement with a male, relative to females on Russet Burbank. These results suggest that although the germplasms display minor abiotic activity on psyllid fertility, tolerance to Lso may be more strongly linked with plant tolerance to the pathogen rather than effects on host acceptance behaviors.
Immune regulation of islet homeostasis and adaptation
Authors: Guo Jinglong , Fu Wenxian
Published: March 2020

The islet of Langerhans produces endocrine hormones to regulate glucose homeostasis. The normal function of the islet relies on the homeostatic regulations of cellular composition and cell–cell interactions within the islet microenvironment. Immune cells populate the islet during embryonic development and participate in islet organogenesis and function. In obesity, a low-grade inflammation manifests in multiple organs, including pancreatic islets. Obesity-associated islet inflammation is evident in both animal models and humans, characterized by the accumulation of immune cells and elevated production of inflammatory cytokines/chemokines and metabolic mediators. Myeloid lineage cells (monocytes and macrophages) are the dominant types of immune cells in islet inflammation during the development of obesity and type 2 diabetes mellitus (T2DM). In this review, we will discuss the role of the immune system in islet homeostasis and inflammation and summarize recent findings of the cellular and molecular factors that alter islet microenvironment and β cell function in obesity and T2DM.
Robotic approach to treat Median Arcuate Ligament syndrome: a case report
Authors: Bustos Roberto , Papamichail Michail , Mangano Alberto , Valle Valentina , Giulianotti Pier Cristoforo
Published: March 2020

The Median Arcuate Ligament (MAL) syndrome is the symptomatic compression of the celiac trunk by the MAL and other ganglionic periaortic tissue. Despite its rarity, this condition is significant from a clinical, diagnostic and management standpoint and it is usually a diagnosis of exclusion. A 61-year-old female with history of intermittent postprandial epigastric pain was diagnosed with MAL syndrome during CT scan imaging (no other causes of pain were identified). Patient successfully underwent robotic MAL release with symptoms improvement after surgery. The robotic approach is feasible and may allow a very precise and delicate dissection with release of the MAL.
The integration of heterogeneous information from diverse disciplines regarding persons and goods
Authors: Aram Bethany , López Fernández Aurelio , Muñiz Amian Daniel
Published: March 2020

This article presents a relational database capable of integrating data from a variety of types of written sources as well as material remains. In response to historical research questions, information from such diverse sources as documentary, bioanthropological, isotopic, and DNA analyses has been assessed, homogenized, and situated in time and space. Multidisciplinary ontologies offer complementary and integrated perspectives regarding persons and goods. While responding to specific research questions about the impact of globalization on the isthmus of Panama during the sixteenth and seventeenth centuries, the data model and user interface promote the ongoing interrogation of diverse information about complex, changing societies. To this end, the application designed makes it possible to search, consult, and download data that researchers have contributed from anywhere in the world.
Animal Models in Psychiatry
Authors: McCarty Richard
Published: March 2020

Darwin made a compelling case that studies of animals could provide insights into the behavior of humans. Early studies by Pavlov and Harlow paved the way for further developments of animal models of psychiatric disorders. Seligman and Maier’s learned helplessness model continues to be employed in laboratory studies of stress and depression. It has become clear that no single animal model can possibly reproduce all of the critical facets of a mental disorder in humans. However, animal models do provide an essential element in attempts to understand the mechanisms that underlie mental disorders and to reveal molecular targets for the development of new drug therapies. Concerns have been raised about the reproducibility of laboratory experiments with inbred strains of laboratory mice and rats. Any animal model should be evaluated based upon a battery of behavioral tests and the parameters of stressful stimulation employed in experiments should be chosen with care.
Session 4: What to Do When Things Aren’t Getting Done: Breaking Down Tasks and Problem-Solving
Authors: Sprich Susan E. , Safren Steven A.
Published: March 2020

Problem-solving skills and how to deal with large projects are the focus of this chapter. This session contains information about how to manage overwhelming tasks, those that remain on the task list for many days or weeks without getting completed. Information is provided regarding how to use structured problem-solving to arrive at a solution to a problem. Additionally, the chapter contains information about how to break down large tasks into smaller, more manageable chunks to increase the likelihood of task completion.
Session 5: How to Organize Everything
Authors: Sprich Susan E. , Safren Steven A.
Published: March 2020

This chapter contains information on how to develop effective organizational systems. Information is presented on how to assess the organizational needs of schoolwork, a backpack, a locker, and materials needed for projects. The question of how to transport items to and from school is addressed. Also, the chapter includes a discussion of how to develop systems for other items that might be problematic, including papers, electronic files, clothing, sports equipment, and other items.
Session 7: Optimize the Setting
Authors: Sprich Susan E. , Safren Steven A.
Published: March 2020

This chapter focuses on how to identify environmental distractions when trying to focus on important tasks like homework and how to modify the environment accordingly. There is information presented about the importance of keeping track of important objects (e.g., backpack, phone) and how to set up systems for this. Finally, the chapter contains a discussion of how to use reminders to help with staying on task.
Session 14: Parent Coaching Session 2: Between Adolescent Sessions 7–9
Authors: Sprich Susan E. , Safren Steven A.
Published: March 2020

This chapter describes the second optional parent coaching session. The primary goal of this session is to review parent goals and progress toward those goals. The therapist can also discuss how the contingency management system is working and the status of the school accommodations, if any are in place. The session concludes with helping the parents identify areas for continued improvement and developing a game plan to address the areas for continued improvement.
Functional Competencies
Authors: Corey David M. , Zelig Mark
Published: March 2020

In this chapter, the authors discuss the functional competencies required to conduct psychological evaluations of police candidates and officers, including “occupational competence,” which includes knowledge about the essential functions of police officers, their working conditions and chain of command, and the psychological demands and stressors of police work. The authors provide guidance on how to self-assess for competency, as well as for bias, that, in relation to a particular referral, may preclude a competent assessment. Included are an explanation of how contemporary challenges in policing may shape the criterion standard for assessing psychological suitability and fitness and a brief summary of six interdisciplinary professional practice standards and guidelines documents—from the United States and Canada—that are especially pertinent to evaluations of police suitability and fitness.
Preparation for the Evaluation
Authors: Corey David M. , Zelig Mark
Published: March 2020

In this chapter, the authors review three categories of information psychologists need to obtain before conducting suitability and fitness evaluation: (1) the employer’s foundation for the referral (i.e., whether the employer has demonstrated the legal threshold for mandating the evaluation), (2) the relevant job demands and working conditions of the examinee’s position, and (3) the criterion standard for determining whether the examinee is psychologically suitable or fit for duty. The chapter includes guidance for gathering this necessary information and how to use it to optimize the quality and utility of the evaluation. Also addressed are two other issues that have implications for the evaluation and must be determined in advance: the examinee’s access to the report and records, and the presence of third parties during the evaluation.
The Goodman Oral Board Course
Authors: Levi Allan D.
Published: March 2020

This chapter describes the purpose and format of the Goodman Oral Board certification course. The course includes plenary sessions and breakout sessions, and these are discussed in the chapter. The learning objectives of the course are also outlined. Achievement of the American Board of Neurological Surgery certification, a key milestone on the path to a career in neurosurgery in the United States, is no easy feat, as those of us who have already been through the process well know. It represents the culmination of years of education and training in mastery of a knowledge base that is the foundation on which neurosurgeons rely as they provide the best care for patients throughout their careers.
Thoughts on Techniques in Answering Oral Board Questions
Authors: Levi Allan D.
Published: March 2020

This chapter describes the ABNS examination process and provides techniques for responding to the examiner’s questions. The chapter analyzes the best approach to case-based questions and focuses on the areas of content and style of the examinee’s response. How one can improve in each of these areas are important and pitfalls are also addressed. Discussion of how to prepare your case defense from submission to examination day is also described. How to prepare for the defense of indications and complications and whether to cite references are also discussed. The chapter concludes with do’s and don’ts on exam day.
Neurology
Authors: O’Phelan Kristine
Published: March 2020

The purpose of the Oral Board Examination is to determine a candidate’s competency in neurosurgical disorders, as well as in neurological disorders which may mimic neurosurgical conditions. Clearly, this goal of the examination process must be kept in the back of an examinee’s mind during questioning. It is not uncommon for a candidate to be presented imaging studies that clearly appear surgical; however, after carefully listening to the history and relevant neurological findings, it will become apparent that the imaging does not explain the patient’s symptoms. When this occurs, start by trying to localize the lesion within the neuraxis—brain, brainstem, spinal cord, peripheral nerve, neuromuscular junction, or the muscle itself. Clues such as hyporeflexia or hyperreflexia and distribution or absence of sensory symptoms are key. Then develop a differential diagnosis of neurological conditions that may present in these areas—vascular, demyelinating, inflammatory, axonal loss, and neuromuscular blockade.

Some of the common neurological ailments that the oral board examinee needs to be well aware of include amyotrophic lateral sclerosis, multiple sclerosis, Guillain-Barré syndrome, and Parsonage-Turner syndrome (brachial plexitis), some of which are covered either in this chapter or in other relevant chapters.