bluuebunny/crossref_metadata_2025 huggingface dataset:
Implantation of leadless pacing systems in patients early after tricuspid valve surgery: A feasible option
Authors: Theis Cathrin , Huber Carola , Kaesemann Philipp , Kaiser Bastian , Heinrich Hannah , Albert Marc , Nagib Ragi , Franke Ulrich F. W. , Bekeredjian Raffi
Published: September 2020

Background

After tricuspid valve (TV) surgery due to tricuspid regurgitation (TR), patients needing a permanent pacemaker often receive an epicardial lead implantation. This may result in delayed recovery from open‐chest surgery and increased postoperative risk. Leadless pacemaker (LPM) implantation may represent a valuable option.

Methods and Results

A total of 14 consecutive patients underwent LPM implantation (Micra Transcatheter Pacing System, Medtronic, Minneapolis, MN) early after TV surgery. The pacing indication in those patients was atrial fibrillation with a slow atrio‐ventricular (AV) conduction or atrial fibrillation and a concomitant AV block III. Three patients already had a pacemaker prior to surgery, which was explanted during TV repair. Three patients received a valve replacement with a bioprosthesis, while the remaining eight patients received a TV repair. All procedural data and device measurements during and after LPM implantation were recorded. Transthoracic echocardiography was performed prior and post LPM implantation, showing no changes in TV or bioprosthesis performance. The device measurements were within an adequate range: threshold: 0.83 ± 0.34 V @ 0.24 ± 0 ms, impedance: 480 ± 58.88 ohm, and R‐wave: 10.10 ± 3.60 mV. LPM implantation was successful in all patients with a mean procedural time of 32 ± 11.8 minutes, fluoroscopy time of 3.71 ± 3.15 minutes, and dose‐area product of 536.67 ± 811.26 cGy/m2.

Conclusions

Implantation of an LPM early after TV surgery is a feasible option. LPM implantation does not affect TV or bioprosthesis performance in transthoracic echocardiography.
The genome of Cleistogenes songorica provides a blueprint for functional dissection of dimorphic flower differentiation and drought adaptability
Authors: Zhang Jiyu , Wu Fan , Yan Qi , John Ulrik P , Cao Mingshu , Xu Pan , Zhang Zhengshe , Ma Tiantian , Zong Xifang , Li Jie , Liu Ruijuan , Zhang Yufei , Zhao Yufeng , Kanzana Gisele , Lv Yanyan , Nan Zhibiao , Spangenberg German , Wang Yanrong
Published: September 2020

Cleistogenes songorica (2n = 4x = 40) is a desert grass with a unique dimorphic flowering mechanism and an ability to survive extreme drought. Little is known about the genetics underlying drought tolerance and its reproductive adaptability. Here, we sequenced and assembled a high‐quality chromosome‐level C. songorica genome (contig N50 = 21.28 Mb). Complete assemblies of all telomeres, and of ten chromosomes were derived. C. songorica underwent a recent tetraploidization (~19 million years ago) and four major chromosomal rearrangements. Expanded genes were significantly enriched in fatty acid elongation, phenylpropanoid biosynthesis, starch and sucrose metabolism, and circadian rhythm pathways. By comparative transcriptomic analysis we found that conserved drought tolerance related genes were expanded. Transcription of CsMYB genes was associated with differential development of chasmogamous and cleistogamous flowers, as well as drought tolerance. Furthermore, we found that regulation modules encompassing miRNA, transcription factors and target genes are involved in dimorphic flower development, validated by overexpression of CsAP2_9 and its targeted miR172 in rice. Our findings enable further understanding of the mechanisms of drought tolerance and flowering in C. songorica, and provide new insights into the adaptability of native grass species in evolution, along with potential resources for trait improvement in agronomically important species.
Cutaneous granulomas as the presenting manifestation of Griscelli syndrome type 2
Authors: Gotesman Ryan , Ramien Michele , Armour Christine M. , Pham‐Huy Anne , Kirshen Carly
Published: September 2020

Griscelli syndrome type 2 is a rare autosomal recessive disorder characterized by hypopigmentation, silvery hair, and immunological dysfunction with no primary neurological impairment. We report an 18‐month‐old girl with Griscelli syndrome type 2 who presented to the dermatology department for cutaneous granulomas that developed following live‐attenuated vaccination. Two compound heterozygous variants in the RAB27A gene were subsequently identified. She developed hemophagocytic lymphohistiocytosis, the key immunological concern, at age 5 years.
Genotype and clinical outcomes in children with congenital adrenal hyperplasia
Authors: Yoon Ju Young , Cheon Chong Kun
Published: September 2020

Background

The study aimed to delineate the genotypic features and endocrine / metabolic profiles in patients with 21‐hydroxylase deficiency.

Methods

Subjects were diagnosed with 21‐hydroxylase deficiency by direct Sanger sequencing or multiple ligation‐dependent probe amplification analysis and followed up in Pusan National University Children's Hospital from July 2008 to April 2019. The genotype, phenotype, and endocrine and metabolic profiles in children and young adults with congenital adrenal hyperplasia were investigated.

Results

Of a total of 33 patients, 16 (48.5%) were males. Median age was 7.4 years (range, 0.1–23.8 years). Thirty (90.9%) had salt‐wasting phenotypes. Eleven (33.3%) initially presented with abnormality in a neonatal screening test without other symptoms. Among the 17 girls, seven received genital surgery. Sixty‐five alleles from the 33 patients were evaluated. The distribution of CYP21A2 gene mutations revealed an intron 2 splice site (c.293‐13A>G or c.293‐13C>G) mutation as the most common one (22, 33.8%), followed by c.518T>A (10, 15.4%) and a large deletion / conversion (7, 10.8%), in order. One novel mutation was detected, c.332del(p.G111fs). Among the 27 patients aged >2 years, fifteen (55.6%) were obese / overweight, and ten (37.0%) needed growth hormone therapy due to short stature. Among the seven subjects aged >2 years and having high‐risk genotype, five had impaired fasting glucose, three had precocious puberty, and four used growth hormone. A greater proportion of the high current corticosteroid dose group had impaired fasting glucose than in the low‐dose group (64.3 vs 23.1%, P = 0.031).

Conclusions

Early monitoring of endocrine and metabolic complications from childhood might benefit patients with congenital adrenal hyperplasia.
Revegetation to slow buckthorn reinvasion: strengths and limits of evaluating management techniques retrospectively
Authors: Wragg Peter D. , Schuster Michael J. , Roth Alexander M. , Bockenstedt Paul , Frelich Lee E. , Reich Peter B.
Published: September 2020

Understanding the long‐term success of ecosystem restoration following invasive plant removal is challenging. Long‐term experiments are costly and slow to yield results, while management decisions must often be made immediately. Alternatively, retrospective studies can leverage contrasting historical management strategies to provide insight into long‐term vegetation responses. We used a retrospective approach to evaluate how management techniques and site characteristics affected re‐establishment of an invasive shrub, Rhamnus cathartica (common buckthorn), in midwestern North America. Following removal, buckthorn re‐establishes rapidly from resprouts and seeds, so follow‐up control is required but often lacking. We hypothesized that revegetating using native herbaceous seed after removing buckthorn increases herbaceous cover that competitively suppresses buckthorn regeneration, to a degree. We surveyed 46 management units at 24 sites. Revegetated units had higher herbaceous cover, lower buckthorn cover, and half the ratio of buckthorn:herbaceous cover compared with unseeded units. These effects, although considerable on average, were detected against a background of high variance. Seeding increased herbaceous cover and reduced buckthorn relative abundance more strongly on less acidic, more clayey soils and where follow‐up herbicide was not applied. Additional variability in revegetation impacts may have arisen from buckthorn resprouts having a head‐start on planted seeds. Only one site had both seeded and unseeded management units. This lack of blocking—a common challenge in retrospective studies—reduced statistical power. This investigation illustrates how retrospective studies can offer relatively inexpensive first assessments of long‐term effects of management techniques; for more rigorous inference, researchers can partner with managers to conduct long‐term experiments.
Recent Advances in Probabilistic Dose–Response Assessment to Inform Risk‐Based Decision Making
Authors: Chiu Weihsueh A. , Paoli Greg M.
Published: September 2020

Paradoxically, risk assessments for the majority of chemicals lack any quantitative characterization as to the likelihood, incidence, or severity of the risks involved. The relatively few cases where “risk” is truly quantified are based on either epidemiologic data or extrapolation of experimental animal cancer bioassay data. The paucity of chemicals and health endpoints for which such data are available severely limits the ability of decisionmakers to account for the impacts of chemical exposures on human health. The development by the World Health Organization International Programme on Chemical Safety (WHO/IPCS) in 2014 of a comprehensive framework for probabilistic dose–response assessment has opened the door to a myriad of potential advances to better support decision making. Building on the pioneering work of Evans, Hattis, and Slob from the 1990s, the WHO/IPCS framework provides both a firm conceptual foundation as well as practical implementation tools to simultaneously assess uncertainty, variability, and severity of effect as a function of exposure. Moreover, such approaches do not depend on the availability of epidemiologic data, nor are they limited to cancer endpoints. Recent work has demonstrated the broad feasibility of such approaches in order to estimate the functional relationship between exposure level and the incidence or severity of health effects. While challenges remain, such as better characterization of the relationship between endpoints observed in experimental animal or in vitro studies and human health effects, the WHO/IPCS framework provides a strong basis for expanding the breadth of risk management decision contexts supported by chemical risk assessment.
The regularity of the multiple higher‐order poles solitons of the NLS equation
Authors: Zhang Yongshuai , Tao Xiangxing , Yao Tengteng , He Jingsong
Published: September 2020

Based on the inverse scattering method, the formulae of one higher‐order pole solitons and multiple higher‐order poles solitons of the nonlinear Schrödinger equation (NLS) equation are obtained. Their denominators are expressed as , where is a matrix frequently constructed for solving the Riemann‐Hilbert problem, and the asterisk denotes complex conjugate. We take two methods for proving is invertible. The first one shows matrix is equivalent to a self‐adjoint Hankel matrix , proving . The second one considers the block‐matrix form of , proving . In addition, we prove that the dimension of is equivalent to the sum of the orders of pole points of the transmission coefficient and its diagonal entries compose a set of basis.
Working Time Accounts and Turnover*
Authors: Launov Andrey
Published: September 2020

Working time accounts are essentially bookkeeping tools that allow firms to smooth their demand for hours employed. Descriptive literature suggests that working time accounts can reduce layoffs and inhibit increases in unemployment during recessions. In a model of optimal labor demand, I show that working time accounts do not necessarily guarantee fewer layoffs at the firm level. Layoffs can fall or rise depending on whether a firm meets an economic downturn with a surplus or a deficit of hours, and on how productive the firm is. On aggregate and in expected terms, however, working time accounts reduce job destruction.
‘You have to call the right name' – Operation Joshua meets Cosmology and Catholicism at Lake Chambri in Papua New Guinea
Authors: Falck Christiane
Published: September 2020

In the Sepik, names feature centrally in political and religious contexts. Esoteric knowledge about totemic names enables Nyaura men to achieve status and power and can set them in contact with spirits. A recently arrived Pentecostal/evangelical movement—Operation Joshua—claims to have found the true name of God, whom it presents as being radically different to the beings people's ancestors have known. At Lake Chambri, however, the Nyaura (West Iatmul) community Timbunmeli had accommodated Catholicism to their culture long before Operation Joshua came to their village. While Operation Joshua demonizes Nyaura spirits, the Catholic community understands God to be an ancestral being for whom different clans know different names. Taking a political ontology perspective, I analyze the encounter of Operation Joshua and Nyaura Catholicism in Timbunmeli in relation to cosmo‐ontological politics pursued by ambitious Nyaura men and different denominations. I suggest that denominational pluralism creates ontological pluralism in Timbunmeli, where different actors engage different truth claims concerning the being and reality of central Christian figures in their world‐making practices.
‘Not anymore, not yet’: Australian–Hungarians rediscover the ‘old‐new’ Hungary
Authors: Petra Andits
Published: September 2020

This article examines the return visits of Australian‐Hungarians to their homeland after 1989 and the different types of homecoming experiences after an extended period of separation. The focus of the paper is returnees’ perceptions of changes to Hungary or lack thereof. I analyse the distinction between the ‘desired/nostalgic past’, which Hungarian returnees nurtured during the decades of separation and expected to rediscover upon return, and the ‘disdained past’ of the Communist dictatorship, which they had fled and hoped never to encounter again. The findings demonstrate that people interpret both past and present in relation to hopes, expectations and disappointments situated within particular nationalist imaginaries, political projects and ideological prisms. This allows us to analyse the nexus between local, national and diasporic belonging through post‐socialist identities, orientations toward democracy and understandings of ‘nation’.
Changes in antimicrobial resistance patterns of ocular surface bacteria isolated from horses in the UK: An eight‐year surveillance study (2012‐2019)
Authors: Chalder Ria H. , Knott Tim , Rushton James O. , Nikolic‐Pollard Danica
Published: September 2020

Purpose

To identify temporal changes in antimicrobial resistance of ocular surface bacteria isolated from clinically symptomatic equine eyes in the South West of the UK.

Study design

Retrospective.

Methods

Clinical and laboratory records of horses treated for suspected bacterial ocular surface disease (ulcerative and non‐ulcerative) at a single facility between January 2011 and December 2019 were reviewed. Cases were included if they underwent ocular surface sampling, aerobic bacterial culture, and antimicrobial susceptibility testing. Cases were split into two time periods based on when sampling occurred: “early” (2012‐2015) and “late” (2016‐2019) to enable identification of temporal trends in resistance to chloramphenicol, gentamicin, fusidic acid, neomycin, cloxacillin, ofloxacin, and polymyxin B.

Results

A total of 125 samples from 110 horses were included in analyses. Culture‐positive isolates were identified in 76/110 (60.8%) samples. Principal isolates includedStaphylococcispp. (n = 45; 64.3%),Streptococci spp. (n = 14; 20%), andEnterobacter spp. (n = 11; 15.7%). There was a significant increase in resistance to chloramphenicol over time (P = .007) and a decrease in resistance to ofloxacin that approached significance (P = .059). Chloramphenicol (100%) and gentamicin (85.7%) had the highest overall in‐vitro efficacy during the early and late periods, respectively. There was no significant difference in the type of bacteria isolated across the two time periods.

Conclusions

These results suggest a potential increase in resistance to chloramphenicol among bacteria isolated from the ocular surface of horses in the South West UK, reinforcing the value of surveillance to guide the empirical use of antimicrobials.
Automated RBC Exchange has a greater effect on whole blood viscosity than manual whole blood exchange in adult patients with sickle cell disease
Authors: Ait Abdallah Nassim , Connes Philippe , Di Liberto Gaetana , Offredo Lucile , Beaumont Jean Louis , Menouche Dehbia , Debbache Karima , Jebali Amna , Habibi Anoosha , Pirenne France , Galacteros Frédéric , Ranque Brigitte , Bartolucci Pablo
Published: September 2020

Background

Blood transfusion is the cornerstone treatment to reduce the clinical severity of sickle cell disease (SCD), but we need to maintain the haematocrit (Hct) within an acceptable range to avoid a deleterious increase in blood viscosity. The aim of this study was to compare the effects of manual versus automated red blood cell (RBC) Exchange on haematological parameters and blood viscosity.

Study design and methods

This prospective, single‐centre, open nonrandomized observational study included forty‐three sickle cell patients: 12 had automated RBC Exchange and 31 manual RBC Exchange. Samples were collected in EDTA tubes just before and within one hour after the end of the RBC Exchange to measure the haematological parameters and blood viscosity.

Results

Both automated and manual RBC Exchange decreased haemoglobin S levels and leucocyte and platelet counts, but the decrease was greater for automated RBC Exchange. Manual RBC Exchange caused a significant rise in haematocrit and haemoglobin levels and did not change blood viscosity. In contrast, automated RBC Exchange decreased blood viscosity without any significant change in haematocrit and only a very slight increase in haemoglobin levels. The change in blood viscosity correlated with the modifications of haematocrit and haemoglobin levels, irrespective of the RBC Exchange procedure. When adjusted for the volume of RBC Exchange, the magnitude of change in each biological parameter was not different between the two procedures.

Conclusion

Our study demonstrates that the automated RBC Exchange provided greater haematological and haemorheological benefits than manual RBC Exchange, mainly because of the higher volume exchanged, suggesting that automated RBC Exchange should be favoured over manual RBC Exchange when possible and indicated.
Cryopreserved platelets and their suitability in being re‐suspended in additive solution
Authors: McLean Colin , McMillan Loraine , Petrik Juraj , Fraser Alasdair R. , Morrison Alex
Published: September 2020

Background

Cryopreserved platelets are generally produced and stored in plasma. With the advent of additive solutions being routinely used it would be prudent to examine producing and storing these units in a platelet additive solution (SSP+).

Study design and methods

Platelet concentrates were prepared from twenty overnight held whole blood units with 10 being re‐suspended in 100% plasma and 10 in approximately 70% SSP + and 30% plasma. All had 6% v/v DMSO added prior to storage at −80°C. On thawing plasma stored platelets were re‐constituted in fresh plasma with additive prepared platelets being subsequently suspended in 100% SSP+. Sample analysis was assessed pre cryopreservation, post thaw and 4 h.

Results

We noted a significant increase in our annexin V levels along with a decrease in GP1bα Von Willebrand binding sites post thaw. The platelets ability to change shape was also significantly reduced as observed with our HSR and ESC values. However, despite this there was still sufficient material within the platelet to allow them to be viable as observed with our thromboelasticity results which, were still observed to be within normal parameters post thaw We also observed an increase in Extracellular vesicles post thaw, suggesting platelet damage which was supported by the reduction in platelet counts. Although there were still sufficient numbers to meet the minimum requirements of the UK guidelines.
Gone, but haven't forgotten: insights on plasmapheresis donation from lapsed donors
Authors: Thorpe Rachel , Nguyen Lilly , Masser Barbara M. , Van Dyke Nina , Davison Tanya E.
Published: September 2020

Background and Objectives

Blood Collection Agencies in several countries have implemented strategies to increase the number of plasmapheresis collections. Despite this, a sizable minority of plasma donors lapse from donation each year, with little research conducted on this topic. An understanding of the plasma donation experience from the perspective of lapsed donors, insights into why they stopped donating and their views on returning to donate may provide opportunities to intervene to increase the retention and reactivation of plasma donors.

Materials and Methods

A qualitative approach was used in this study, with 17 lapsed plasma donors (no plasma donation for at least 13 months) interviewed. A purposive recruitment strategy was used to obtain a sample with diversity in gender (47% men), age (M = 36·2 years, SD = 13·6) and donation experience (M = 9·2 years, SD = 9·6). Semi‐structured, narrative interviews were conducted, with participants describing their plasma donation careers chronologically from first donation to most recent.

Results

The majority of participants described at least some aspect of the plasma donation procedure as unpleasant. However, adverse experiences were only attributed to lapsing in a minority of cases, with other participants reporting significant life events, perceived ineligibility and concerns about the safety of the procedure as the reason why they lapsed.

Conclusion

It is common for lapsed plasma donors to intend to donate again in the future. Recommendations are given for strategies to address barriers to returning, noting the potential role of tailored education and support.
Effect of waste activated sludge pretreatment methods to mitigate Gordonia foaming potential in anaerobic digestion
Authors: Garg Aparna , Stensel H. David , Bucher Bob , Sukapanpotharam Pardi , Winkler Mari K. H.
Published: September 2020

In this study, waste activated sludge obtained from two full‐scale treatment plants with foaming issues was pretreated with acid/alkali treatment, acid‐phase fermentation, thermal treatment, ultrasonic treatment and metal salt treatment to investigate their effect on foam mitigation. Waste activated sludge was characterized for foaming index prior and after each pretreatment method. Among all pretreatment methods investigated, acid/alkali treatment and acid phase fermentation showed highest reduction of 53% in foaming and in inactivation of Gordonia amarae filaments. Pretreatment methods that resulted in sharp decrease in the foaming index concurred with higher amounts of dead foam formers as confirmed using live/dead staining and the PMA‐qPCR technique. Pretreating with iron(III)chloride gave good foaming reductions with 54% decrease in foaming potential at a concentration of 260 mg/L but did not result in a decline of foam formers as confirmed by live/dead staining. Ultrasonic treatment did not prove effective in lowering the foaming index or killing the G. amarae filaments.
Curing of Glass Fiber/Epoxy Resin Composites Using Multiwalled Carbon Nanotubes Buckypaper as a Resistive Element
Authors: Rojas J. A. , Ribeiro B. , Rezende M. C.
Published: September 2020

Glass fiber/epoxy resin composites (GF/EP) were prepared using one and three multiwalled carbon nanotube buckypapers (BPs) as a resistive element. Compared to the conventional hot compression molding process that demanded 4200 W to fabricate the GF/EP laminate, the proposed curing process consumed only 63 W, representing a saving power of 98.5%. The thermal distribution of the BP and their composites were recorded using an infrared thermometer. Differential scanning calorimetry (DSC) curves have not shown a residual cure, suggesting the curing process using the BP as a resistive element was effective. The cross section views of the laminates were analyzed by scanning electron microscopy (SEM), and the mechanical characterizations were performed by impulse excitation technique (IET), compression shear test (CST), and interlaminar shear strength (ILSS). The results demonstrated that the BP composites showed a good consolidation between the prepregs layers, and presented no significant variations in the mechanical tests compared to the traditional hot compression molding process. Nevertheless, dynamic mechanical analyses (DMA) showed a slight decrease in the BP composites’ storage moduli compared to GF/EP laminate.
Effect of Dynamic Chemical Etching on the Pore Structure, Permeability, and Mechanical Properties of Ti-Nb-Zr Scaffolds for Medical Applications
Authors: Sheremetyev V. , Dubinskiy S. , Iqbal M. A. , Lukashevich K. , Prokoshkin S. , Brailovski V.
Published: September 2020

Improving the post-processing of metallic porous tissue scaffolds is an essential step to create a new generation of superelastic implants for the replacement of damaged bone tissue. In this study, the dynamic chemical etching technique is applied to improve the permeability and to optimize the porous structure of Ti-Nb-Zr scaffolds fabricated by the powder metallurgy-based space holder technique. The etched scaffolds are characterized in terms of their porous structure geometry, permeability, and mechanical properties. It is shown that an increase in porosity from 49% to 54% during the etching is mainly due to an increase in the number of 100 to 800 μm-diameter pores, from 30% to 50% of them measuring from 100 to 300 μm in size. These changes in the porous structure lead to a significant increase of its permeability, i.e., from (0.1–15) × 10−11 m2 before etching to (44–91) × 10−11 m2, after etching; these permeability ranges corresponding to those of bone tissues. Furthermore, the etched scaffolds show systematically higher yield compressive stresses as compared to the as-sintered scaffolds of equivalent porosities. Finally, the highly permeable etched Ti-Nb-Zr scaffolds with a porosity varying from 40% to 60% exhibit an apparent Young’s modulus ranging from 8.6 to 1.9 GPa and an ultimate compressive strength from 650 to 190 MPa, which can be considered as a promising balance of properties for the potential use of these scaffolds as bone implants.
Effect of Process Parameters on Wavy Interfacial Morphology During Magnetic Pulse Welding
Authors: Zhang Shunyi , Lueg-Althoff Joern , Hahn Marlon , Tekkaya A. Erman , Kinsey Brad
Published: September 2020

Magnetic pulse welding (MPW) is a solid-state welding process that bonds similar and dissimilar metals using a high velocity collision. In this paper, effects of impact velocity, target tube thickness, and mandrel inclusion on the interfacial morphology were investigated through the welding of tubular parts, Al6060T4 (flyer) to Cu-ETP (target), by electromagnetic compression. The hypothesis tested in this research is that a “well-supported target,” i.e., either a thick target or the support of a mandrel, allows for vortices to be created at the interface during MPW provided that the impact velocity is sufficient. The mandrel used in the experiments was polyurethane with a Shore hardness of 92A, which was pre-stressed via a washer and nut. The impact velocity was measured via photon Doppler velocimetry (PDV) and used for the setup of numerical simulations. A 2D axisymmetric numerical model was implemented in LS-DYNA to predict the interfacial morphology. Thermal analyses in the numerical model were used to predict the local melting locations and compared with experimental observations. Both experimental and numerical results showed that the interfacial wavelength increased with an increase in the impact velocity and target thickness. Similarly, a thin target with mandrel support also caused an increase in the wavelength. Vortices were only generated with appropriate impact velocities and well-supported targets, i.e., again either a thick target or the support of a mandrel.
Syngas Generation From Landfills Derived Torrefied Refuse Fuel Using a Downdraft Gasifier
Authors: Laohalidanond Krongkaew , Kerdsuwan Somrat , Burra Kiran Raj Goud , Li Jinhu , Gupta Ashwani K.
Published: September 2020

Landfill reclamation is a good solution to utilize the wasted land occupied by municipal solid waste dumpsites or landfill sites. This also offers a good means to recover valuable materials and form environmentally benign green refuse-derived fuel (RDF) for use in power production. However, due to the heterogenous composition of the wastes, it is crucial to homogenize and upgrade the waste hydrocarbon fuel properties. Torrefaction is a thermochemical process that utilizes low temperature and inert environment to drive off the moisture and volatile fractions present in wastes to form valuable fuel. This upgraded RDF from reclaimed landfills offer high energy density and favorable hydrophobicity for use as a fuel feedstock in gasification to produce syngas for power generation. The objectives of this study are to first upgrading the reclaimed landfill wastes to RDF using torrefaction followed by its conversion to form clean syngas in a downdraft gasifier. This study examines the effect of air ratio on syngas heating value and cold gas efficiency. A comparison is made on the syngas produced from gasification using reclaimed landfill wastes and torrefied RDF. Experiments were conducted using a 10 kg/h lab-scale downdraft gasifier. The air ratios examined were 0.22, 0.27, and 0.32. The results showed an optimum air ratio of 0.27 operated with a gasifier using torrefied RDF. The results showed improved syngas quality, in terms of syngas composition, lower heating value, and cold gas efficiency. The lower heating value of 4.22 MJ/Nm3 and the cold gas efficiency of 65.84% were achieved. The results showed that landfill mining can provide ultimate solution to get rid of dumped wastes from landfills using torrefaction for high-quality fuel followed by the recovery of green and clean syngas energy using gasification.
Introductory guide to backgrounds in XPS spectra and their impact on determining peak intensities
Authors: Engelhard Mark H. , Baer Donald R. , Herrera-Gomez Alberto , Sherwood Peter M. A.
Published: September 2020

Photoelectron and Auger peaks are central to most of the important uses of x-ray photoelectron spectroscopy (XPS), and thus, they receive the most attention in many types of analysis. Quantitative chemical analysis using XPS requires the assessment of the intensities of the photoemission peaks of the elements detected. Determination of peak intensities requires separation of the photoelectron peak signals from the background on which the peaks rest. For the determination of peak area intensities, the background is subtracted from overall signal intensity. The spectral background is also critical when peak fitting is used to determine intensities of overlapping peaks, and the model of background used in this process can impact the results. In addition to the impact on quantitative analysis, information about the depth distribution of elements in the near surface region can often be obtained by visual inspection of the background and quantified using appropriate modeling. This introductory guide provides some basic information about backgrounds in the XPS analysis, describes the types of background models that are commonly used, suggests some of their strengths and weaknesses, and provides examples of their use and misuse. Although the fundamental nature of some components of the background signals in XPS is not understood, indicating that none of the models in use are fully correct and the area is subject to active research, appropriate good practices have been established for most routine analysis. The guide describes good practices, identifies errors that frequently appear in the literature, and uses examples to demonstrate the impacts of background selections on determinations of peak intensities.
PhysPort Use and Growth: Supporting Physics Teaching with Research-based Resources Since 2011
Authors: McKagan Sarah B. , Strubbe Linda E. , Barbato Lyle J. , Mason Bruce A. , Madsen Adrian M. , Sayre Eleanor C.
Published: September 2020

PhysPort (www.physport.org) has become the go-to place for physics educators to learn to apply research-­based teaching and assessment in their classrooms. Usage (defined as the total number of visits) has doubled every two years since the site was released in 2011, and 20% of all U.S. physics faculty and 7% of U.S. high school physics teachers are now verified educators on PhysPort. The lead author conceived of PhysPort in 2007 after meeting many physics instructors interested in incorporating results of physics education research (PER) in their classrooms but with no idea where to start. At the time, most PER results were only available in research journals, which required instructors’ time and effort to find articles and read them, and there was no central place to learn about results and implications for classroom practice. Throughout its development, PhysPort has been based on user research: PhysPort staff interview physics instructors about their needs, design the site based on those needs, and conduct usability testing to see how they meet those needs. PhysPort is a joint product of the American Association of Physics Teachers (AAPT) and Kansas State University (K-State), with contributions from many universities, funded by the National Science Foundation (NSF), and a library within the ComPADRE.org digital library. The site (originally called the PER User’s Guide) was first funded by an NSF grant in 2009 and released in November 2011. This article presents an overview of resources on PhysPort, discussion of research and development of the site, and data on the continuing growth of site usage.
The New Definitions of the Mole and Kilogram: How and Why These SI Units Took their New Status
Authors: Gal Jean-François
Published: September 2020

Important changes were recently made to the International System of Units. The readers involved in chemistry and physics, either teachers or advanced students, should be aware of the new definitions of the kilogram, the mole, and more generally of the changes in International System of Units (SI, “Système International”) recently approved at the 26th General Conference of Weights and Measures (26ème Conférence Générale des Poids et Mesures, Versailles, 13-16 November 2018). The general methodology for introducing the changes, along with the historical context, was recently described. The resolutions adopted during this conference, written in parallel in English and French, redefine the four fundamental SI units: kilogram (kg), ampere (A), kelvin (K), and mole (mol). The historical definition of kg followed the 1st General Conference of Weights and Measurements in 1889, and was based on a physical object (Fig. 1), as had been the meter until 1960.
How Perception of Being Recognized or Not Recognized by Instructors as a “Physics Person” Impacts Male and Female Students’ Self-Efficacy and Performance
Authors: Li Yangqiuting , Whitcomb Kyle , Singh Chandralekha
Published: September 2020

Physics has historically been portrayed as a field for brilliant men. Many prior studies have focused on the reasons for women’s underrepresentation in physics and related disciplines from different perspectives and strategies to improve the learning environments so that all students can excel in physics courses. Due to societal stereotypes, women often have significantly lower physics self-efficacy than men even when they perform similarly, and many shy away from physics-related majors and careers. Moreover, being recognized by the instructor as a student who can excel in physics can be valuable for all students in physics courses. However, it is particularly important for underrepresented students, including women and ethnic and racial minorities, partly due to the societal stereotypes associated with who can excel in physics and lack of role models.
Modeling ICBM Trajectories Around a Rotating Globe with Systems Tool Kit
Authors: Blanco Philip
Published: September 2020

In the April 2018 issue of TPT, Joseph Amato presented an analysis of intercontinental ballistic missile (ICBM) trajectories as applied to recent test launches from North Korea. Using properties of their elliptical paths, he derived relationships between launch velocity, elevation angle, and maximum range. However, this approach cannot include the effects of Earth’s rotation, even though they should be significant for ICBM speeds ≈ 6 km/s and flight times ≈ 25 min. Here I use the aerospace industry software Systems Tool Kit (STK), freely available for school use, to model ICBM paths launched from various locations on a spinning globe. The results illustrate the effects of a rotating Earth on ballistic motion, while demonstrating STK’s utility as a simulation tool for educators and students.
Bouncing Balls and Geometric Progressions
Authors: De Luca R. , Di Mauro M. , Naddeo A.
Published: September 2020

Observing the bouncing of a marble on a table is a rather common experience. The tic-tac sound of the rigid ball, nevertheless, carries quite a pleasant surprise. In fact, by measuring the total time of bouncing Δt, the coefficient of restitution can be estimated. As is well known, in an inelastic collision the kinetic energy is not conserved, and therefore the speed decreases. The speeds vi and vf, before and after the collision occurs, respectively, are related as follows: νf=ενi,(1) where ε < 1. By measuring the initial height h0 from which the marble is released, we find that ε=T−2h0gT+2h0g,(2) where g is the acceleration due to gravity and T is the total time from initial release until the ball stops bouncing.
Real-time visualization of electrical circuit schematics: An augmented reality experiment setup to foster representational knowledge in introductory physics education
Authors: Lauer Luisa , Peschel Markus , Malone Sarah , Altmeyer Kristin , Brünken Roland , Javaheri Hamraz , Amiraslanov Orkhan , Grünerbl Agnes , Lukowicz Paul
Published: September 2020

Empirical research has shown that augmented reality (AR) has the potential to promote learning in different contexts. In particular, this has been shown for AR-supported physics experiments, where virtual elements (e.g., measurement data) were integrated into the learners’ visual reality in real time: compared to traditional experimentation, AR reduced cognitive load and promoted conceptual learning. Drawing upon previous work from this column, we present an AR-supported experiment on simple electrical circuits that allows for real-time visualization including highlighting of electrical circuit schematics using either smartglasses or tablet computers. The experiment addresses students in introductory physics education and holds potential to provide visual assistance for complex electrical circuits in secondary or higher physics education.
COVID-19 can affect the heart
Authors: Topol Eric J.
Published: September 2020

COVID-19 has a spectrum of potential heart manifestations with diverse mechanisms
Planktonic and Biofilm Activity of Eravacycline against Staphylococci Isolated from Periprosthetic Joint Infections
Authors: Zhuchenko Georg , Schmidt-Malan Suzannah , Patel Robin
Published: September 2020

MIC and minimum biofilm bactericidal concentration (MBBC) values of eravacycline against 185 staphylococci from periprosthetic joint infections were determined.
Staphylococcus aureus
had MICs of ≤0.25 μg/ml. MICs for methicillin-susceptible and -resistant
Staphylococcus epidermidis
were ≤1 and ≤2 μg/ml, respectively.
S. aureus
and
S. epidermidis
MBBC
50
and MBBC
90
values were 8 and 16 μg/ml for each, showing poor anti-staphylococcal biofilm activity using the method studied.
Favipiravir and the Need for Early Ambulatory Treatment of SARS-CoV-2 Infection (COVID-19)
Authors: McCullough Peter A.
Published: September 2020

It is becoming increasingly clear that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), like most human viral infections, will require multiple drugs in combination to treat COVID-19 illness. In this issue of the Journal, Doi and colleagues describe successful treatment of patients with early COVID-19 with favipiravir, an oral polymerase inhibitor, to rapidly and substantially clear SARS-CoV-2 from nasal secretions irrespective if it was started relatively early or later within the first week of infection.
Extracellular Vesicle Biogenesis and Functions in Gram-Positive Bacteria
Authors: Briaud Paul , Carroll Ronan K.
Published: September 2020

Extracellular vesicles (EVs) are membrane-derived lipid bilayers secreted by bacteria and eukaryotic cells. Bacterial membrane vesicles were discovered over 60 years ago and have been extensively studied in Gram-negative bacteria. During their production, EVs are loaded with proteins, nucleic acids, and various compounds that are subsequently released into the environment. Depending on the packaged cargo, EVs have a broad spectrum of action and are involved in pathogenesis, antibiotic resistance, nutrient uptake, and nucleic acid transfer.
Summary of Novel Bacterial Isolates Derived from Human Clinical Specimens and Nomenclature Revisions Published in 2018 and 2019
Authors: Munson Erik , Carroll Karen C.
Published: September 2020

Knowledge of novel prokaryotic taxon discovery and nomenclature revisions is of importance to clinical microbiology laboratory practice, infectious disease epidemiology, and studies of microbial pathogenesis. Relative to bacterial isolates derived from human clinical specimens, we present an in-depth summary of novel taxonomic designations and revisions to prokaryotic taxonomy that were published in 2018 and 2019. Included are several changes pertinent to former designations of or within
Propionibacterium
spp.
Complete Genome Sequences of
Lactobacillus
Strains C25 and P38, Isolated from Chicken Cecum
Authors: Hassan Hosni M. , Mendoza Mary , Rezvani Morvarid , Koci Matthew D. , Dickey Allison N. , Scholl Elizabeth H.
Published: September 2020

We report the complete circular genome sequences of
Lactobacillus crispatus
strain C25, its plasmid, and
Lactobacillus animalis
strain P38; both strains were isolated from the cecum of 4-week-old chickens. These isolates represent potential probiotic strains for poultry.
pSETT4, an Improved φC31-Based Integrative Vector System for
Actinoplanes
sp. SE50/110
Authors: Schaffert Lena , Jacob Lucas , Schneiker-Bekel Susanne , Persicke Marcus , März Camilla , Rückert Christian , Pühler Alfred , Kalinowski Jörn
Published: September 2020

The pSETT4 vector integrates into the
Actinoplanes
sp. SE50/110 chromosome via the bacteriophage φC31 integrase and allows cloning of a gene of interest by Golden Gate assembly (BsaI). T4 terminators surround the expression cassette to isolate the transcriptional unit and to prevent antisense transcription. The system can be used in other
Actinomycetales
by exchanging the promoter.
Coding-Complete Genome Sequences of Three SARS-CoV-2 Strains from Bangladesh
Authors: Akter Shahina , Banu Tanjina Akhtar , Goswami Barna , Osman Eshrar , Uzzaman Mohammad Samir , Habib M. Ahashan , Jahan Iffat , Mahmud Abu Sayeed Mohammad , Sarker M. Murshed Hasan , Hossain M. Saddam , Shamsuzzaman A. K. Mohammad , Nafisa Tasnim , Molla M. Maruf Ahmed , Yeasmin Mahmuda , Ghosh Asish Kumar , Al Din Sheikh M. Selim , Ray Utpal Chandra , Sajib Salek Ahmed , Hossain Maqsud , Khan M. Salim
Published: September 2020

We report the sequencing of three severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) genomes from Bangladesh. We have identified a unique mutation (NSP2_V480I) in one of the sequenced genomes (isolate hCoV-19/Bangladesh/BCSIR-NILMRC-006/2020) compared to the sequences available in the Global Initiative on Sharing All Influenza Data (GISAID) database. The data from this analysis will contribute to advancing our understanding of the epidemiology of SARS-CoV-2 in Bangladesh as well as worldwide at the molecular level and will identify potential new targets for interventions.
Genome Sequences of Two Microcystis aeruginosa (
Chroococcales
,
Cyanobacteria
) Strains from Florida (United States) with Disparate Toxigenic Potentials
Authors: Lefler Forrest W. , Barbosa Maximiliano , Berthold David E. , Laughinghouse H. Dail
Published: September 2020

Here, we report the draft genomes of two
Microcystis aeruginosa
strains, i.e.,
M. aeruginosa
BLCC-F108, which was isolated from a toxic bloom in eutrophic waters in Lake Okeechobee (Florida, USA), and
M. aeruginosa
BLCC-F158, which was isolated from mesotrophic waters in Lake Tohopekaliga (Florida, USA). Genomic analyses show disparate toxin potentials for these two strains.
Complete Genome Sequences for
Pseudomonas
sp. Strains 29A and 43A
Authors: Baltrus David A. , Clark Meara , Humphrey Parris T. , Whiteman Noah K.
Published: September 2020

Pseudomonas
sp. strains 29A and 43A were originally isolated from the phyllosphere of individual plants of
Cardamine cordifolia
(Brassicaceae). Here, we report complete genome sequences for these two closely related strains, assembled using a hybrid approach combining Illumina paired-end reads and longer reads sequenced on an Oxford Nanopore MinION flow cell.
Complete Chloroplast Genome Sequence of a Black Spruce (Picea mariana) from Eastern Canada
Authors: Lo Theodora , Coombe Lauren , Lin Diana , Warren René L. , Kirk Heather , Pandoh Pawan , Zhao Yongjun , Moore Richard A. , Mungall Andrew J. , Ritland Carol , Bousquet Jean , Jones Steven J. M. , Bohlmann Joerg , Thomson Ashley , Birol Inanc
Published: September 2020

Here, we present the chloroplast genome sequence of black spruce (
Picea mariana
), a conifer widely distributed throughout North American boreal forests. This complete and annotated chloroplast sequence is 123,961 bp long and will contribute to future studies on the genetic basis of evolutionary change in spruce and adaptation in conifers.
Complete Genome Sequence of Ceftriaxone-Resistant Neisseria gonorrhoeae SS3160, Isolated in Tokyo, Japan
Authors: Miyake Hirofumi , Mitobe Morika , Kubota Hiroaki , Takano Hiroki , Yokoyama Keiko , Sadamasu Kenji
Published: September 2020

We report the complete genome sequence of ceftriaxone-resistant
Neisseria gonorrhoeae
SS3160, harboring the mosaic
penA
-60.001 allele. This Japanese isolate has a unique sequence type (ST), ST13429, which was determined by multilocus sequence typing from the chromosome sequence (2,214,955 bp). It carries two plasmids, pConjugative (39,057 bp) and pCryptic (4,207 bp).
Draft Genome Sequence of Brucella ceti Isolated in the Western Pacific Ocean
Authors: Ueno Yuichi , Kumagai Masahiko , Kanamori Hiroyuki , Yanagisawa Makio , Kino Sayuri , Shigeno Satoru , Osaki Makoto , Takamatsu Daisuke , Katsuda Ken , Maruyama Tadashi , Ohishi Kazue
Published: September 2020

In 2018,
Brucella ceti
was isolated from a bottlenose dolphin from the western Pacific Ocean. Here, we report a draft genome sequence of the isolate BD1442 of sequence type 27, which is the only sequence type known to have been isolated from human clinical cases.