bluuebunny/crossref_metadata_2025 huggingface dataset:
Forming the inner flange of a rib by pulsed-magnetic field pressure
Authors: Kurlaev N V , Ahmed Soliman M E , Detinov M B
Published: February 2021

Electromagnetic flanging is a hole-protrusion of parts, a potential technology for forming sheet aluminum metal, provides rigidity, allows positioning and fixing. This paper describes the behavior of a workpiece formed by an electromagnetic flanging, in which the initial blank of annealed aluminum alloy D16AM with a circular precut hole is formed into the first part of the inner flanging (as the first operation of manufacturing a part of the rib). The purpose of this article is to assess the ability of electromagnetic shaping to produce flanges for aircraft components and to study the forming process using numerical simulation. Design of electromagnetic flanges with some elementary geometric shapes, the purpose of which is to clarify a few geometric defects encountered and to propose some solutions. The numerical model of this part was developed in the LS-DYNA computing environment. An example of the numerical simulation of electromagnetic forming of the inner flange of a rib with the obtained shape of the workpiece mesh using a clamp is given. To avoid corrugation at the corner of the workpiece, the magnetic force was increased by reducing the area of the coil adjacent to the corner.
Data-driven system identification and optimal control of an active rotor-bearing system
Authors: Babin A
Published: February 2021

Both diagnostics and control in any piece of rotating machinery is getting more and more attention as computational powers allow storage of big data sets, and we are able to perform approximation, feature extraction and classification of big data. Such transfer from traditional diagnostics and control to machine learning and decision making also makes new ways of system identification based on artificial neural network architectures more attractive as they are more flexible in representing non-linear dynamics. Data-driven linear system identification or non-linear system identification based on artificial neural networks when coupled with optimal control obtained using either traditional or machine learning approaches result in a powerful tool for rotor-bearing system modeling and control that allows using identified model for predictive analysis as well. In the present paper such approach is presented for a rotor system on two journal fluid-film bearings, one of the bearings is equipped with a set of two actuators for feeding pressure control that allows adjustments of rotor position in the bearing. Such adjustments are aimed at decreasing power loss due to friction, so the system is more energy efficient. The presented approach of system identification and modeling can be applied to any similar rotor system.
Welded joint permissible defects influence on the resource of a vertical steel tank under low-cycle loading
Authors: Petrovskaya M V , Konygin S B , Kosareva E A , Kats N G , Levi A A
Published: February 2021

This paper is devoted to the VST determining the residual life issues by the shell welds low-cycle fatigue criterion with permissible defects, taking into account a typical stress concentrator, which has not been fully studied. The fatigue tests results analysis for materials made of low-alloy steel, taking into account welded joints, is given. The Ansys software package has built a model and calculated the stress-strain a vertical steel tank lower belt state for storing oil and oil products VST 20000 with a branch pipe. It is shown that the VST design most dangerous point is in the branch pipe upper part. The maximum stresses and stress amplitudes were obtained in the stub pipe zone and the wornom seam. The cycles to failure performed calculations number showed that the lower VST belt without welded joints wall area withstands 2.4 times more loading cycles than the area with a welded seam and 9.3 times more than the dangerous point in the nozzle stub area.
From technologies to algorithms through the prism of algorithm analysis
Authors: Galkina A I , Grishan I A
Published: February 2021

In anticipation of the predicted transition from the technology economy to the algorithm economy the article is devoted to the analysis of algorithms as an object of intellectual activity of universities registered for the period from 2010 to the present. The selection of information about algorithms and their statistical processing is carried out automatically by the collector_stat program developed by the authors of the article. This article is based on the results of the National Supercomputer Forum (NSCF-2019) and the materials of the joint Fund for electronic resources “Science and education”.
Technological process automation of drinking water deodoration using the methods of machine learning
Authors: Ponomarev S B , Isakov V G , Gorohov M M , Ponomarev D S
Published: February 2021

The study presents an analysis and the possibility of applying machine learning methods to automate the technological process of drinking water deodorization. One of the most actual and popular machine learning methods today is the use of artificial neural networks. Possible neural network structures, activation functions and the number of neural connections were described. The relevance of the introduction of these methods into the system of water management is described.
Hardware implementation of the coding algorithm based on FPGA
Authors: Ibraimov M K , Tynymbayev S T , Park Jongtae , Zhexebay D M , Alimova M A
Published: February 2021

In this article, the efficient implementation multiplier of polynomials irreducible polynomials modulo for cryptographic encryption and decryption using FPGA is presented. For this, the Nexys 4 board based on the Artix-7 Field Programmable Gate Array (FPGA) from Xilinx was chosen. Verilog HDL is used to describe the circuit for reducing a number modulo. The results of a timing simulation of the device are presented in the form of time diagrams for a given 8-bit number, confirming the correct operation of the device. The developed encryption algorithm on the basis of non-positional polynomial notations is intended for software, hardware, and also software and hardware implementation. The main hardware-implemented device in non-positional algorithm of the cryptographic transformation is a device for the multiplication of polynomials irreducible polynomials modulo, which produces routine calculations on data encryption. These mathematical operations are computationally intensive and fundamental arithmetic operations, which are intensively used in many fields such as cryptography, number theory, and finite field arithmetic.
Fuzzy model for assessing the organizational effect of an intelligent process control system
Authors: Smirnov V A , Milova V M , Smirnova M S , Matelenok I V , Zhilnikova N A
Published: February 2021

The article considers the problem of assessing the organizational effect of the functioning of an intelligent decision support system for controlling complex technical systems at the level of a technological control system. The level of organization of activity is used as an indicator of the organizational effect of an intellectual system. To obtain the numerical values of individual indicators of organizational effects, a system of mathematical models is presented that takes into account the specifics of the subject area. Aggregation of heterogeneous indicators to obtain generalized and complex indicators, which are measured on different scales and have a different range of values, is based on a fuzzy classification of parameter values and a fuzzy inference model using the Takagi-Sugeno algorithm. The obtained quantitative assessment of the organizational effect is complemented by a qualitative assessment containing a linguistic description of the level of organization of activities and the degree of expert’s confidence in the result. The considered system of mathematical models for calculating the indicators of the organizational effect can be supplemented depending on the goals, the degree of detail and the depth of analysis and used in the analysis of the effectiveness of existing and future decision support systems and automated information systems at all stages of the life cycle.
Modeling and analysis of fractal growth patterns from the material point
Authors: Teplov A A
Published: February 2021

The growth of fractals from a material point is modeled using single-phase and multi-phase algorithms for linear fractals and polygonal fractal forms. The connection of fractal growth processes with the phenomena of formation in nature is considered. A method for analyzing growth processes and their characteristics is proposed. The growth laws of fractals metric characteristics and their transformation when changing the growth algorithm are revealed. The growth path of fractal points and the distribution of the slope angles of their elements are analyzed. The influence of stochastic fluctuations in the length of fractal elements on the process of its growth is modeled. It is shown that the algorithms and methods used for analyzing growth processes have a great potential for modernization and adaptation to a wide range of tasks.
Modification of the ant colony algorithm for multiversion software application development
Authors: Saramud M V , Kovalev I V , Kovalev D I , Voroshilova A A
Published: February 2021

The article discusses a modification of the ant colony algorithm, which is used to solve the problem of forming the composition of multiversion software with a dynamic architecture. The algorithm was tested for a specific composition of multiversion modules. The graphical dependencies that characterize the changes in the parameters of the cost and reliability of the multiversion software complex with the specified resource constraints are presented.
Control system for nonlinear dynamic processes in a buck converter
Authors: Andriyanov A I
Published: February 2021

The paper deals with a control system for nonlinear dynamic processes in a buck converter based on the target-oriented control and belonging to the class of discrete automatic control systems. The main task of the proposed system is to stabilize the desired dynamic mode, which provides a minimum amplitude of output voltage fluctuation. The author proposes a hardware-software calculation method of the fixed point coordinates in the desired periodic mode, when the average values of state variables are determined by hardware using low-frequency filters, and the fluctuation amplitude of the output physical quantity in the desired dynamic mode is estimated on the basis of analytical expressions. Computer simulation of the proposed system is performed and its efficiency is shown. The proposed approach to estimating the coordinates of the fixed point of the desired mode in real time can be applied to a wide class of DC/DC converters.
Investigation of wear behavior of carbide based coated rolling roll materials under dry and lubricated conditions
Authors: Korkmaz Seyma , Pehlivanoglu Mert , Orak Abdulkadir , Cetin M Huseyin
Published: February 2021

In this study, the effect of TiCN and WC-Co coatings on the tribological performance of spheroidal graphite cast iron materials was investigated by wear tests under dry and lubricated conditions. The mechanical and physical effects of the coating processes were analysed by microhardness measurements and visual methods (SEM, EDX, XRD). The tribological effect of WC-Co and TiCN coated specimens were investigated by ball-on-plate wear tests carried out under dry and boron oil emulsion (5% concentration) conditions at 50 N load and 60 rpm sliding speed parameters. The friction coefficient and wear volume results were obtained to investigate the effect of the coating process and boron oil emulsion on friction and wear behaviour. The wear mechanisms were determined with SEM images obtained from the worn surfaces and surfaces analysed elementally with EDX images. Additionally, surface morphology was examined with surface roughness measurements and 2D–3D topography images. According to the microhardness measurement results, it was observed that the spheroidal graphite cast iron with 290 HV hardness reached 1559 HV with TiCN coating and 1440 HV with WC-Co coating. According to the wear test results, it was determined that TiCN and WC-Co coatings decreased the friction coefficient by 32.51% and 12.80%, respectively. When the effect of boron oil usage compared to dry environmental conditions, it was concluded that the friction coefficient and wear volume decreased by a maximum of 54.80% and 53.70%, respectively. Additionally, the roughness values decreased in the experiments where the boron oil emulsion was used. However, although the TiCN coating improved the surface quality, the WC coating negatively affected the surface quality. Surface form images obtained with 2D and 3D topography also support the alteration in roughness values.
Hints of dark bosons spotted in ytterbium isotopes
Authors: Jarman Sam
Published: February 2021

Conflicting results on the existence of a hypothetical dark-matter particle have been announced by two separate teams studying the atomic spectra of isotopes of ytterbium and calcium.
Telescope proposed to monitor Betelgeuse dimming
Authors: Gater Will
Published: February 2021

An international team of astronomers has proposed a telescope to monitor the bright star Betelgeuse to provide clues about the cause of its sudden drop in brightness.
Making a difference where it matters
Authors: Wade Jess
Published: February 2021

With COVID-19 further exposing educational divides, Jess Wade says the importance of physics teachers has never been more critical
Integrating and valuing the ‘extracurricular’
Authors: Jackson Penny
Published: February 2021

In response to the statement from the Institute of Physics (IOP) entitled “Diversity and inclusion: a collective enterprise”
New, old and inbetween
Authors: Hare Helen , Atkin Keith , Jones Francis
Published: February 2021

In response to Niki Bell’s Forum article “Putting new physics on the syllabus” (August 2020), in which she suggests adding modern physics discoveries to the education system; and Andy French’s response to Bell’s article, in the Feedback letter “Missing maths”
Life or something like it?
Authors: Lloyd Bob
Published: February 2021

In response to Keith Cooper’s Frontiers article “Signatures of life found in the clouds of Venus” (October 2020), which revealed that astronomers have discovered phosphine in the atmosphere of Venus.
Flights of fancy
Authors: Hill John
Published: February 2021

In response to the Frontiers article “Protons could be lighter than thought” (October p5), in which Isabelle Dumé explored new measurements of the proton–electron mass ratio.
Physics challenges for green aviation
Authors: Tillotson Brian
Published: February 2021

Commercial air travel has changed a lot since the first aeroplane took passengers around a century ago. Brian Tillotson explores the future challenges to make aviation greener
The hunt for another Earth: a love story
Authors: Gardner Kate
Published: February 2021

Massachusetts Institute of Technology (MIT) planetary scientist Sara Seager’s memoir is a love story, where love comes in multiple forms: romantic love, parental love, friendship, plus love of nature, of the universe and of maths. The Smallest Lights in the Universe: a Memoir opens with Seager recounting a particularly bad day six months after the death of her husband.
Ask me anything: Michelle Simmons
Authors: Durrani Matin
Published: February 2021

Michelle Simmons is director of the Centre of Excellence for Quantum Computation and Communication Technology at the University of New South Wales, Australia. A pioneer in atomic-scale silicon devices, she has built the world’s smallest transistor, the narrowest conducting wires, 3D atomic electronics and the first two-qubit silicon gate. In 2018 Simmons was named Australian of the Year.
A matter of evidence
Authors: Atkinson Gary A
Published: February 2021

“This experimental evidence does not match our theoretical prediction. We shall admit its failures and attempt a new theory with neither shame nor pride.” That’s how good science should work.
Frequency-resolved photon correlations in cavity optomechanics
Authors: Schmidt M K , Esteban R , Giedke G , Aizpurua J , González-Tudela A
Published: February 2021

Frequency-resolved photon correlations have proven to be a useful resource to unveil nonlinearities hidden in standard observables such as the spectrum or the standard (color-blind) photon correlations. In this manuscript, we analyze the frequency-resolved correlations of the photons being emitted from an optomechanical system where light is nonlinearly coupled to the quantized motion of a mechanical mode of a resonator, but where the quantum nonlinear response is typically hard to evidence. We present and unravel a rich landscape of frequency-resolved correlations, and discuss how the time-delayed correlations can reveal information about the dynamics of the system. We also study the dependence of correlations on relevant parameters such as the single-photon coupling strength, the filtering linewidth, or the thermal noise in the environment. This enriched understanding of the system can trigger new experiments to probe nonlinear phenomena in optomechanics, and provide insights into dynamics of generic nonlinear systems.
Reinforcement learning in discrete action space applied to inverse defect design
Authors: Loeffler Troy D , Banik Suvo , Patra Tarak K , Sternberg Michael , Sankaranarayanan Subramanian K R S
Published: February 2021

Reinforcement learning (RL) algorithms that include Monte Carlo Tree Search (MCTS) have found tremendous success in computer games such as Go, Shiga and Chess. Such learning algorithms have demonstrated super-human capabilities in navigating through an exhaustive discrete action search space. Motivated by their success in computer games, we demonstrate that RL can be applied to inverse materials design problems. We deploy RL for a representative case of the optimal atomic scale inverse design of extended defects via rearrangement of chalcogen (e.g. S) vacancies in 2D transition metal dichalcogenides (e.g. MoS2). These defect rearrangements and their dynamics are important from the perspective of tunable phase transition in 2D materials i.e. 2H (semi-conducting) to 1T (metallic) in MoS2. We demonstrate the ability of MCTS interfaced with a reactive molecular dynamics simulator to efficiently sample the defect phase space and perform inverse design—starting from randomly distributed S vacancies, the optimal defect rearrangement of defects corresponds a line defect of S vacancies. We compare MCTS performance with evolutionary optimization i.e. genetic algorithms and show that MCTS converges to a better optimal solution (lower objective) and in fewer evaluations compared to GA. We also comprehensively evaluate and discuss the effect of MCTS hyperparameters on the convergence to solution. Overall, our study demonstrates the effectives of using RL approaches that operate in discrete action space for inverse defect design problems.
Optimal flapping wing shape and kinematics are different for different flight velocities: an analysis on local relative wind
Authors: Kumaresan Allwyn , Ganapathy Subramanian L R
Published: February 2021

Different species of insects and birds fly differently. Their wing forms and wing motion are different. Understanding the purpose of this difference will lead to successful development of flapping wing vehicles for different purposes. This paper discusses the influence of one of the important factors which affects the aerodynamic performance of a flapping wing: the local instantaneous relative wind. Its distribution along the span of a flapping wing has been analyzed for the practical flight range of advance ratios ranging from 0 to 1.5 and stroke plane orientations ranging from 0 to 90°. In this domain, the variation of spanwise distributions of magnitude and direction of relative wind are presented separately for downstroke and upstroke of a flapping cycle. Accordingly, qualitative suggestions are given for wing planform design, orientation and twist of the wing, and actuation of wing for effective utilization of the relative wind and obtaining the necessary force distributions for different flight phases. The formulation presented will be helpful for experimenting flapping wings in hovering and forward flight; especially for setting the wing twist for a required angle of attack distribution and designing the flapping kinematics in upstroke and downstroke.
Contrarian effects and echo chamber formation in opinion dynamics
Authors: Ferraz de Arruda Henrique , Benatti Alexandre , Nascimento Silva Filipi , Comin César Henrique , da Fontoura Costa Luciano
Published: February 2021

The relationship between the topology of a network and specific types of dynamics unfolding in networks constitutes a subject of substantial interest. One type of dynamics that has attracted increasing attention because of its several potential implications is opinion formation. A phenomenon of particular importance, known to take place in opinion formation, is echo chambers’ appearance. In the present work, we approach this phenomenon, while emphasizing the influence of contrarian opinions in a multi-opinion scenario. To define the contrarian opinion, we considered theunderdogeffect, which is the eventual tendency of people to support the less popular option. We also considered an adaptation of the Sznajd dynamics with the possibility of friendship rewiring, performed on several network models. We analyze the relationship between topology and opinion dynamics by considering two measurements: opinion diversity and network modularity. Two specific situations have been addressed: (i) the agents can reconnect only with others sharing the same opinion; and (ii) same as in the previous case, but with the agents reconnecting only within a limited neighborhood. This choice can be justified because, in general, friendship is a transitive property along with subsequent neighborhoods (e.g., two friends of a person tend to know each other). As the main results, we found that the underdog effect, if strong enough, can balance the agents’ opinions. On the other hand, this effect decreases the possibilities of echo chamber formation. We also found that the restricted reconnection case reduced the chances of echo chamber formation and led to smaller echo chambers.
Varieties of elementary abelian Lie algebras and degrees of modules
Authors: Chang Hao , Farnsteiner Rolf
Published: February 2021

Let(g,[p])(\mathfrak {g},[p])be a restricted Lie algebra over an algebraically closed fieldkkof characteristicp≥3p\!\ge \!3. Motivated by the behavior of geometric invariants of the so-called(g,[p])(\mathfrak {g},[p])-modules of constantjj-rank (j∈{1,…,p−1}j \in \{1,\ldots ,p\!-\!1\}), we study the projective varietyE(2,g)\mathbb {E}(2,\mathfrak {g})of two-dimensional elementary abelian subalgebras. Ifp≥5p\!\ge \!5, then the topological spaceE(2,g/C(g))\mathbb {E}(2,\mathfrak {g}/C(\mathfrak {g})), associated to the factor algebra ofg\mathfrak {g}by its centerC(g)C(\mathfrak {g}), is shown to be connected. We give applications concerning categories of(g,[p])(\mathfrak {g},[p])-modules of constantjj-rank and certain invariants, calledjj-degrees.
The effect of remote ischaemic preconditioning on postoperative cardiac and inflammatory biomarkers in pancreatic surgery: a randomized controlled trial
Authors: van Zeggeren L , Visser R A , Vernooij L M , Dijkstra I M , Bosma M , Molenaar Q , van Santvoort H C , Noordzij P G
Published: February 2021

Background

Cardiac and inflammatory biomarkers have been associated with adverse outcome after major abdominal surgery. This study investigated the effect of remote ischaemic preconditioning (RIPC) on perioperative concentrations of high-sensitive cardiac troponin (hs-cTn) T and interleukin (IL) 6.

Methods

Adult patients scheduled for elective pancreatic surgery between March 2017 and February 2019 were randomized to either three cycles of upper-limb ischaemia and reperfusion (each 5 min) or a sham procedure before surgery. The primary endpoint was the maximum postoperative hs-cTnT concentration within 48 h after surgery. Secondary endpoints were postoperative myocardial injury (PMI), defined as an absolute increase of hs-cTnT of at least 14 ng/l above baseline concentration, maximum concentration of IL-6 within 48 h after surgery and postoperative complications within 30 days of surgery.

Results

Of 99 eligible patients, 46 underwent RIPC and 46 a sham procedure. RIPC did not reduce the maximum hs-cTnT concentration after surgery (12.6 ng/l RIPC, 16.6 ng/l controls, P = 0.225), nor did it lessen the incidence of PMI (15/45 RIPC, 18/45 controls, P = 0.375). The maximum postoperative IL-6 concentration was 265 pg/ml after RIPC versus 385 pg/ml in controls (P = 0.108). Postoperative complications occurred in 23 RIPC and 24 control patients respectively.

Conclusions

Remote ischaemic preconditioning did not reduce the maximum postoperative hs-cTnT concentration. Postoperative myocardial injury, IL-6 concentrations and postoperative complications were similar between RIPC patients and controls.

Trial registration

Clinicaltrials.gov identifier NCT03460938.
Vitamin C Deficiency in Inflammatory Bowel Disease: The Forgotten Micronutrient
Authors: Dunleavy Katie A , Ungaro Ryan C , Manning Laura , Gold Stephanie , Novak Joshua , Colombel Jean-Frederic
Published: February 2021

Background

Micronutrient deficiencies are common in patients with inflammatory bowel disease (IBD). To date, the literature has focused on vitamin D, vitamin B12, and iron deficiencies.

Methods

We report a case series of 20 patients with IBD and vitamin C deficiency treated at a single tertiary care center.

Results

Sixteen (80%) patients had symptoms of clinical scurvy, including arthralgia, dry brittle hair, pigmented rash, gingivitis, easy bruising, and/or brittle nails. Eighteen patients underwent a nutritional assessment, 10 (56%) patients reported complete avoidance of fruits and vegetables, and 3 (17%) reported reduced intake of fruits and vegetables.

Conclusions

Vitamin C deficiency should be considered in IBD patients, particularly those with reduced fruit/vegetable intake, as it can lead to significant signs and symptoms.
Fecal Incontinence in Inflammatory Bowel Disease
Authors: Kamal Natasha , Motwani Kiran , Wellington Jennifer , Wong Uni , Cross Raymond K
Published: February 2021

Background

Fecal incontinence (FI) is frequently reported in inflammatory bowel disease (IBD).

Methods

We retrospectively reviewed data from the Study of a Prospective Adult Research Cohort with IBD registry.

Results

Three hundred forty-seven patients had Crohn disease and 145 had ulcerative colitis. 14.2% of patients reported FI. FI was associated with active disease. FI was not associated with disease location, phenotype, or perianal involvement. Greater than 50 years of age or 15 years of disease increased the odds of FI and remission decreased the odds of FI.

Conclusions

Further research into the mechanism of FI in IBD is needed.
A new approach to the treatment of advanced heart failure: a case report
Authors: Robles-Mezcua Ainhoa , Villaescusa-Catalán José Manuel , Melero-Tejedor José María , García-Pinilla José Manuel
Published: February 2021

Background

Autonomic imbalance characterized by sympathetic predominance and decreased parasympathetic transmission is a classic feature of heart failure (HF) with reduced left ventricular ejection fraction, leading to disease progression, exercise intolerance, ventricular remodelling, arrhythmias, and premature death. The underlying mechanisms to these processes are not yet fully understood, but the current treatments influence this dysregulation, towards an inhibition of sympathetic hyperactivation. New therapies, such as the stimulation of carotid baroreceptors, enhance this inhibition to restore autonomic balance and to be able to cope with these mechanisms.

Case summary

We report the case of a 76-year-old male with advanced HF at an advanced stage, refractory to optimal treatment, and included in a programme of ambulatory infusions of Levosimendan as compassionate treatment. The patient presented with multiple episodes of decompensated HF secondary to ventricular arrhythmias. A multidisciplinary team decided to implant a baroreceptor stimulator device (Barostim Neo) in order to improve HF symptoms and quality of life, as well as trying to decrease the burden of arrhythmias. The procedure was performed with no complications and good therapeutic response, resulting in a significant reduction of arrhythmias.

Discussion

Treatment with a baroreceptor stimulating device is presented as a safe and effective option in our patients with advanced HF refractory to conventional treatment, to improve their quality of life and reduce symptoms; in addition to appearing as a promising option in those with arrhythmic events, which are difficult to control with usual treatments and procedures.
Case series of late lead dislodgement of Medtronic SelectSecure 3830 pacing leads in growing paediatric patients
Authors: Ng Li Yen , Gallagher Sarah , Walsh Kevin P
Published: February 2021

Background 

The SelectSecure lumenless 3830 pacing lead is often considered to be the pacing lead of choice for transvenous pacing in children because of its small diameter, lead strength, and reliable long-term sensing and pacing characteristics. One of the potential long-term pitfalls of a sturdy pacing lead is relative retraction with growth in children resulting in late lead dislodgement.

Case summary 

We report two cases of late SelectSecure 3830 lead dislodgement at 11.8 years (Case 1) and 8.8 years (Case 2), respectively, post the initial implantation. Case 1 was diagnosed with congenital complete heart block (CHB) at 9 months old when he presented with unconfirmed diphtheria infection. Case 2 was diagnosed with CHB at 14 weeks of age with positive maternal anti-Ro antibodies. Both patients underwent implantation of a transvenous permanent pacemaker implantation with Medtronic SelectSecure 3830 lead due to symptomatic bradycardia. Apart from a pulse generator change at 8.5 years (Case 1) and 7 years (Case 2), respectively, post-implant due to normal battery depletion, both patients are well in the interim.

Discussion 

As part of the pacemaker follow-up for rapidly growing children, we recommend more frequent surveillance of lead ‘tautness’ by chest radiography especially in children with CHB with no underlying heart rhythm.
The proficiency of the original host species determines community-level plasmid dynamics
Authors: Kottara Anastasia , Hall James P J , Brockhurst Michael A
Published: February 2021

Plasmids are common in natural bacterial communities, facilitating bacterial evolution via horizontal gene transfer. Bacterial species vary in their proficiency to host plasmids: whereas plasmids are stably maintained in some species regardless of selection for plasmid-encoded genes, in other species, even beneficial plasmids are rapidly lost. It is, however, unclear how this variation in host proficiency affects plasmid persistence in communities. Here, we test this using multispecies bacterial soil communities comprising species varying in their proficiency to host a large conjugative mercury resistance plasmid, pQBR103. The plasmid reached higher community-level abundance where beneficial and when introduced to the community in a more proficient host species. Proficient plasmid host species were also better able to disseminate the plasmid to a wider diversity of host species. These findings suggest that the dynamics of plasmids in natural bacterial communities depend not only upon the plasmid's attributes and the selective environment but also upon the proficiency of their host species.
Interaction of implant infection-related commensal bacteria with mesenchymal stem cells: a comparison between Cutibacterium acnes and Staphylococcus aureus
Authors: El-Mahdy Taghrid S , Mongaret Céline , Varin-Simon Jennifer , Lamret Fabien , Vernet-Garnier Véronique , Rammal Hassan , Mauprivez Cedric , Kerdjoudj Halima , Gangloff Sophie C , Reffuveille Fany
Published: February 2021

Staphylococcus aureus and Cutibacterium acnes are involved in several tissue infections and can encounter mesenchymal stem cells (MSCs) during their role in tissue regenerative process. C. acnes and S. aureus internalization by three types of MSCs derived from bone marrow, dental pulp and Wharton's jelly; and bacterial biofilm production were compared. Internalization rates ranged between 1.7–6.3% and 0.8–2.7% for C. acnes and S. aureus, respectively. While C. acnes strains exhibited limited cytotoxic effect on MSCs, S. aureus were more virulent with marked effect starting after only 3 h of interaction. Both bacteria were able to produce biofilms with respectively aggregated and monolayered structures for C. acnes and S. aureus. The increase in C. acnes capacity to develop biofilm following MSCs’ internalization was not linked to the significant increase in number of live bacteria, except for bone marrow-MSCs/C. acnes CIP 53.117 with 79% live bacteria compared to the 36% before internalization. On the other hand, internalization of S. aureus had no impact on its ability to form biofilms composed mainly of living bacteria. The present study underlined the complexity of MSCs-bacteria cross-interaction and brought insights into understanding the MSCs behavior in response to bacterial infection in tissue regeneration context.
The association between studying in health promoting schools and adolescent smoking and alcohol consumption in Lithuania
Authors: Maceinaitė Rūta , Šurkienė Genė , Žandaras Žymantas , Stukas Rimantas
Published: February 2021

The concept of the Health Promoting School (HPS) encourages a holistic approach to promoting health in schools, instead of a more traditional education on health. The aim of this paper was to determine the association between studying in a HPS and smoking and alcohol consumption among adolescents. A cross-sectional study of 3574 adolescents from 44 HPS and 66 non-HPSs was conducted. The association between studying in a HPS and smoking and alcohol consumption among adolescents was analysed using logistic regression models. Pearson’s χ2 test was used to determine the differences between HPS and non-HPS students’ sociodemographic characteristics, and the difference in distribution of students who smoked and consumed alcohol at various rates across different groups. Studying in a HPS setting was not significantly associated with adolescent smoking or attempts to smoke. Compared to HPS students, non-HPS students had a significantly higher chance of attempting to consume alcohol and consumed alcohol once a month or more frequently. In comparing the distribution of HPS and non-HPS students according to the frequency of smoking and alcohol consumption across various groups of respondents, it was determined that some factors were associated with frequency of smoking and alcohol consumption among adolescents. The results of the study showed that studying in a HPS was associated with a reduction in both smoking and alcohol consumption, and therefore it is advisable to further develop the HPS network. However, both the individual and educational characteristics of adolescents must be taken into account when planning prevention measures.
Simultaneous Quantitation of Seven Phenethylamine-Type Drugs in Forensic Blood and Urine Samples by UHPLC–MS-MS
Authors: Yang Chu-An , Liu Hsiu-Chuan , Liu Ray H , Lin Dong-Liang , Wu Shu-Pao
Published: February 2021

Abuse of new psychoactive substances (NPS) has become a health and social issue of global concern. p-Methoxyamphetamine (PMA)/p-methoxymethamphetamine (PMMA) with fluoro- or chloro-derivatives of amphetamine and methamphetamine were among the most common drugs found in specimens from fatal cases in Taiwan during the January 2011 to December 2018 period. A liquid–liquid extraction sample preparation protocol with highly sensitive ultra-high performance liquid chromatography–tandem mass spectrometry approach was developed for the simultaneous analysis of seven phenethylamine-type drugs—PMA, PMMA, p-methoxyethylamphetamine, 4-fluoroamphetamine (4-FA), 4-fluoromethamphetamine (4-FMA), 4-chloroamphetamine (4-CA) and 4-chloromethamphetamine (4-CMA)—in postmortem blood and urine specimens. Separation by liquid chromatography was performed by Agilent Zorbax SB-Aq column. Tandem mass spectrometry was operated in Agilent Jet Stream Technology electrospray ionization in positive-ion multiple reaction monitoring mode. An analytical methodology was evaluated using drug-free blood and urine after fortification with 100–2,000 ng/mL of the seven target analytes. Average extraction recoveries were >80%; slightly higher ion suppression was observed for PMA and 4-CA; intra-/inter-day precision (% coefficient of variation) and accuracy were in the ranges of 0.52–12.3% and 85–110%, respectively. Limit of detection and lower limit of quantitation for these seven analytes were both in the 0.5–5 ng/mL range. Interference and carryover were not significant. This relatively simple methodology was found effective and reliable for routine identification and quantitation of these seven analytes in postmortem and antemortem blood and urine specimens received in 2018. Analytical data obtained from these actual cases indicated the following: (i) compared to findings reported during the 2007–2011 period, the use of substituted phenethylamine-type drugs decreased in 2018; (ii) ketamine and 7-aminonimetazepam (the main metabolite of nimetazepam) were the most common co-ingested substances in specimens containing PMA/PMMA, 4-FA/4-FMA, or 4-CA/4-CMA; and (iii) in drug fatalities, the concentration of PMA was significantly higher than the concentration of PMMA in both urine and blood, while the reverse was true in urine specimens from antemortem cases.
Disparities in Cardiovascular Disease Risk Among Hispanic Breast Cancer Survivors in a Population-Based Cohort
Authors: Hu Qingqing , Chang Chun-Pin , Rowe Kerry , Snyder John , Deshmukh Vikrant , Newman Michael , Fraser Alison , Smith Ken , Gren Lisa H , Porucznik Christina , Stanford Joseph B , Gaffney David , Henry N Lynn , Lopez Ivette , Hashibe Mia
Published: February 2021

Background

Breast cancer is the leading cause of cancer death among Hispanic women. The aim of our study was to estimate cardiovascular disease (CVD) risk among Hispanic and non-Hispanic White (NHW) breast cancer survivors compared with their respective general population cohorts.

Methods

Cohorts of 17 469 breast cancer survivors (1774 Hispanic and 15 695 NHW) in the Utah Cancer Registry diagnosed between 1997 and 2016, and 65 866 women (6209 Hispanic and 59 657 NHW) from the general population in the Utah Population Database were identified. Cox proportional hazards models were used to estimate hazard ratios (HRs) for CVD.

Results

The risk of diseases of the circulatory system was higher in Hispanic than NHW breast cancer survivors 1-5 years after cancer diagnosis, in comparison with their respective general population cohorts (HRHispanic = 1.94, 99% confidence interval [CI] = 1.49 to 2.53; HNHW = 1.38, 99% CI = 1.33 to 1.43; 2-sided Pheterogeneity = .01, respectively). Increased risks were observed for both Hispanic and NHW breast cancer survivors for diseases of the heart and the veins and lymphatics, compared with the general population cohorts. More than 5 years after cancer diagnosis, elevated risk of diseases of the veins and lymphatics persisted in both ethnicities. The CVD risk due to chemotherapy and hormone therapy was higher in Hispanic than NHW breast cancer survivors but did not differ for distant stage, higher baseline comorbidities, or baseline smoking.

Conclusions

We observed a risk difference for diseases of the circulatory system between Hispanic and NHW breast cancer survivors compared with their respective general population cohorts but only within the first 5 years of cancer diagnosis.
Evaluating psychiatrists’ attitudes and expectations about pharmacists’ role in psychiatry in Jordan
Authors: Abdel-Qader Derar H , Al Jomaa Esraa E , Silverthorne Jennifer , Shnaigat Walid , Hamadi Salim , Al Meslamani Ahmad Z
Published: February 2021

Objectives

Evaluating Jordanian pharmacists’ roles in psychiatry from psychiatrists perspective.

Methods

An electronic survey was sent to 100 psychiatrists registered in the Jordanian Psychiatrists Association. Statistical analysis included descriptive statistics and multivariate logistic regression.

Key findings

A total of 80 psychiatrists completed the survey (response rate 80%). Most psychiatrists thought that pharmacists are unable to give individuals with mental illness enough time to discuss their medications (62/80, 77.6%) and to monitor psychotropic medications (PM) efficacy (50/80, 62.6%). Around half of respondents thought that, in the future, pharmacists would not be able to suggest PM for patients (42/80, 52.6%), nor changes in PM dosages (37/80, 46.3%). Most psychiatrists emphasized the importance of psychiatric courses to improve pharmacists’ role.

Conclusion

Although psychiatrists were generally not satisfied with the current role of pharmacists, they had positive expectations about pharmacists’ competency to do certain activities and to assist them in designing drug therapy plans.
Synergistic adaptations: freezing tolerance is associated with desiccation tolerance and activation of violaxanthin de-epoxidase in wintergreen ferns
Authors: Holmlund Helen I
Published: February 2021

This article comments on:

Fernández-Marín B, Arzac MI, López-Pozo M, Laza JM, Roach T, Stegner M, Neuner G, García-Plazaola JI. 2021. Frozen in the dark: interplay of night-time activity of xanthophyll cycle, xylem attributes, and desiccation tolerance in fern resistance to winter. Journal of Experimental Botany 72, 3168–3184.
Characteristics and Outcomes Among Hospitalized COVID-19-Positive Patients in a Nonurban Environment
Authors: Lennon Robert P , Demetriou Theodore J , Khalid M Fahad , Van Scoy Lauren Jodi , Miller Erin L , Dong Huamei , Zgierska Aleksandra E
Published: February 2021

Introduction

Virtually all hospitalized coronavirus disease-2019 (COVID-19) outcome data come from urban environments. The extent to which these findings are generalizable to other settings is unknown. Coronavirus disease-2019 data from large, urban settings may be particularly difficult to apply in military medicine, where practice environments are often semi-urban, rural, or austere. The purpose of this study is compare presenting characteristics and outcomes of U.S. patients with COVID-19 in a nonurban setting to similar patients in an urban setting.

Materials and Methods

This is a retrospective case series of adults with laboratory-confirmed COVID-19 infection who were admitted to Hershey Medical Center (HMC), a 548-bed tertiary academic medical center in central Pennsylvania serving semi-urban and rural populations, from March 23, 2020, to April 20, 2020 (the first month of COVID-19 admissions at HMC). Patients and outcomes of this cohort were compared to published data on a cohort of similar patients from the New York City (NYC) area.

Results

The cohorts had similar age, gender, comorbidities, need for intensive care or mechanical ventilation, and most vital sign and laboratory studies. The NYC’s cohort had shorter hospital stays (4.1 versus 7.2 days, P < .001) but more African American patients (23% versus 12%, P = .02) and higher prevalence of abnormal alanine (>60U/L; 39.0% versus 5.9%, P < .001) and aspartate (>40U/L; 58.4% versus 42.4%, P = .012) aminotransferase, oxygen saturation <90% (20.4% versus 7.2%, P = .004), and mortality (21% versus 1.4%, P < .001).

Conclusions

Hospitalists in nonurban environments would be prudent to use caution when considering the generalizability of results from dissimilar regions. Further investigation is needed to explore the possibility of reproducible causative systemic elements that may help improve COVID-19-related outcomes. Broader reports of these relationships across many settings will offer military medical planners greater ability to consider outcomes most relevant to their unique settings when considering COVID-19 planning.
Dark energy survey year 1 results: Constraining baryonic physics in the Universe
Authors: Huang Hung-Jin , Eifler Tim , Mandelbaum Rachel , Bernstein Gary M , Chen Anqi , Choi Ami , García-Bellido Juan , Huterer Dragan , Krause Elisabeth , Rozo Eduardo , Singh Sukhdeep , Bridle Sarah , DeRose Joseph , Elvin-Poole Jack , Fang Xiao , Friedrich Oliver , Gatti Marco , Gaztanaga Enrique , Gruen Daniel , Hartley Will , Hoyle Ben , Jarvis Mike , MacCrann Niall , Miranda Vivian , Rau Markus , Prat Judit , Sánchez Carles , Samuroff Simon , Troxel Michael , Zuntz Joe , Abbott Tim , Aguena Michel , Annis James , Avila Santiago , Becker Matthew , Bertin Emmanuel , Brooks David , Burke David , Carnero Rosell Aurelio , Carrasco Kind Matias , Carretero Jorge , Castander Francisco Javier , da Costa Luiz , De Vicente Juan , Dietrich Jörg , Doel Peter , Everett Spencer , Flaugher Brenna , Fosalba Pablo , Frieman Josh , Gruendl Robert , Gutierrez Gaston , Hinton Samuel , Honscheid Klaus , James David , Kuehn Kyler , Lahav Ofer , Lima Marcos , Maia Marcio , Marshall Jennifer , Menanteau Felipe , Miquel Ramon , Paz-Chinchón Francisco , Malagón Andrés Plazas , Romer Kathy , Roodman Aaron , Sanchez Eusebio , Scarpine Vic , Serrano Santiago , Sevilla Ignacio , Smith Mathew , Soares-Santos Marcelle , Suchyta Eric , Swanson Molly , Tarle Gregory , Thomas Diehl H , Weller Jochen ,   The DES Collaboration
Published: February 2021

Measurements of large-scale structure are interpreted using theoretical predictions for the matter distribution, including potential impacts of baryonic physics. We constrain the feedback strength of baryons jointly with cosmology using weak lensing and galaxy clustering observables (3 × 2pt) of Dark Energy Survey (DES) Year 1 data in combination with external information from baryon acoustic oscillations (BAO) and Planck cosmic microwave background polarization. Our baryon modelling is informed by a set of hydrodynamical simulations that span a variety of baryon scenarios; we span this space via a Principal Component (PC) analysis of the summary statistics extracted from these simulations. We show that at the level of DES Y1 constraining power, one PC is sufficient to describe the variation of baryonic effects in the observables, and the first PC amplitude (Q1) generally reflects the strength of baryon feedback. With the upper limit of Q1 prior being bound by the Illustris feedback scenarios, we reach $\sim 20{{\ \rm per\ cent}}$ improvement in the constraint of $S_8=\sigma _8(\Omega _{\rm m}/0.3)^{0.5}=0.788^{+0.018}_{-0.021}$ compared to the original DES 3 × 2pt analysis. This gain is driven by the inclusion of small-scale cosmic shear information down to 2.5 arcmin, which was excluded in previous DES analyses that did not model baryonic physics. We obtain $S_8=0.781^{+0.014}_{-0.015}$ for the combined DES Y1+Planck EE+BAO analysis with a non-informative Q1 prior. In terms of the baryon constraints, we measure $Q_1=1.14^{+2.20}_{-2.80}$ for DES Y1 only and $Q_1=1.42^{+1.63}_{-1.48}$ for DESY1+Planck EE+BAO, allowing us to exclude one of the most extreme AGN feedback hydrodynamical scenario at more than 2σ.