bluuebunny/crossref_metadata_2025 huggingface dataset:
The relationship between the vibration energy of cutting and the wear resistance of the cutting wedge
Authors: Lapshin V P , Khristoforova V V
Published: September 2020

This work is an attempt to assess the impact of tool vibrations during cutting on the stability of the cutting wedge. In this paper, a numerical experiment is conducted to model the wear process of a cutting wedge based on the use of the Volterra operator of the second kind. The article presents the results of modeling the Volterra operator for various variants of vibration cutting processes that differ from each other in the amount of energy of the observed vibration signal. The results of experiments showed that the stability of the cutting wedge decreases with increasing vibration energy of the tool. This is due to the fact that when the vibration dynamics of cutting increases, the actual path traversed by the tool during processing increases, which increases the total work performed when processing a given part.
Method for diagnosing the state of bearings of spindle units by the energy of the vibration signal
Authors: Lapshin V P , Turkin I A , Koba Ya D
Published: September 2020

The work considers improved approach to assessing the serviceability of bearing assemblies of spindle groups of metal-cutting machines. As a basic malfunction, we looking a variant of the defect of the outer ring of the rolling bearing separator. For this task the calculated values of the vibration frequencies were obtained, and a full-scale experiment was conducted with the evaluation of the vibration signal on a large spectrum of frequencies. The results of the experiment showed that it is possible to assess the degree of bearing damage both from the spectrum of signal amplitudes and from the rms value of the vibration signal (RMS). However, studies have shown that the most beneficial, from the point of view of diagnostics, is to consider RMS not for the entire vibration signal, but only in the frequency range corresponding to the diagnosed bearing malfunction.
Selective suppression of amplitudes of frictional oscillations
Authors: Kolesnikov V I , Shapovalov V V , Ozyabkin A L , Shestakov M M , Kornienko R A , Pertseva T D , Petrik A M
Published: September 2020

Maintenance of sanitary codes and standards during operation of railway sorting sta-tions, in particular, standards which concern noise levels, is now the most pressing task. The analysis of noise has been carried out during operation of brake beams of car hump retarders with car wheelsets; the most problem frequency ranges have been revealed. On the basis of mod-elling bench tests with application of techniques of physical and mathematical modelling and tribospectral identification of friction processes we carried out selection of noise-suppressing cladding material which would reduce the level of acoustic noise at interaction of metal surfaces. Results of operational trials have confirmed efficiency of the chosen material in noise reduction.
Improving the efficiency of the path - rolling stock system based on the implementation of anisotropic frictional bonds
Authors: Shapovalov V V , Kolesnikov V I , Kharlamov P V , Kornienko R A , Petrik A M
Published: September 2020

Unlike the materials widely represented in domestic and foreign scientific, technical and reference literature, the article theoretically substantiates the need to take into account in laboratory and bench tests of mechanical systems with friction units the presence and interconnection of dynamic processes occurring in a frictional contact and in a mechanical quasilinear subsystem; ensure identical: parameters of macro- and micro-roughness of contacting surfaces, frequencies and forms of natural vibrations, physical and mechanical properties of tribocontacts, as well as dynamic (integral) characteristics of a natural object and its physical model. The article presents the methods of physical and mathematical modeling and tribospectral identification of friction processes. The features of these methods and an example of dynamic monitoring of a mobile mechanical system using the example of a friction system: “way - rolling stock” are consideredThe first section in your paper.
Find the optimal trajectory of the secondary discrete part to ensure efficient processing of cellulose fiber
Authors: Kuimov D N , Minkin M S
Published: September 2020

This work presents the results of investigation of trajectories of elements implemented by electromechanical converter with discrete secondary part. The efficiency of implementation of various trajectories was evaluated.
Design and technological support for manufacturing a PAA emitter based on a 3D-model using SolidWorks CAD
Authors: Lebedev V A , Kukareko A S , Kukareko V A
Published: September 2020

This article presents a methodology for manufacturing the S-band phased antenna array (PAA) emitter based on a calculated 3D-model, which provides the necessary design and technological requirements. As a method of manufacturing the emitter, the technology of milling processing on a CNC machine was chosen. Verification of milling processes based on the SolidWorks CAM software package was performed.
Alternative dynamic torsion test to evaluate the elastic modulus of polymers
Authors: Piedade Lucas Pereira , Pintão Carlos Alberto Fonzar , Foschini Cesar Renato , Silva Marcos Ribeiro da , Azevedo Neto Nilton Francelosi
Published: September 2020

This work presents an alternative for the determination of the torsion modulus, G, of polymers. These materials may be subjected to shear stresses in some structural applications; thereby, the knowledge of G is of great interest. For this purpose, a mechanical system featuring a simplified torsion pendulum version and a rotational motion sensor (RMS) coupled to it was used to establish an angular position as a function of time. The applied technique is considered non-destructive and makes it possible to obtain G without the Poisson’s ratio through an equation derived from mechanical spectroscopy and material strength. The main goal is to present and validate the employment of this method for polymers. Therefore, circular cross-sectional samples of extruded polytetrafluoroethylene (PTFE) were subjected to torsional stresses, in which a physical and quantitative explanation is given for the frequency and G curves as a function of the prefixed rotational inertia (I), length (L), and diameter (d). Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were also made to ensure the reliability of data. It is possible to establish an L/d ratio, which explains why G converges to a single value when the sample dimensions are different from each other. It was found that G is approximately 350 MPa for an L/d ratio equivalent to 10.64. Such a value is within limits found in the literature, opening the possibility of assessing other polymers.
Insectivorous birds in the Neotropics: Ecological radiations, specialization, and coexistence in species-rich communities
Authors: Sherry Thomas W , Kent Cody M , Sánchez Natalie V , Şekercioğlu Çağan H
Published: September 2020

Insectivorous birds reach their highest diversity in the tropics and represent a striking variety of morphological and behavioral specializations for foraging, yet explanations for these patterns are inadequate because of both our limited understanding of the drivers of ecological diversification within and among clades and of coexistence mechanisms in particular. Here we synthesize recent information on Neotropical insectivorous birds, including their diversity, evolutionary ages and locations of origin, phylogenies, and both competitive and predator–prey species interactions. We propose a novel evolutionary hypothesis for the origin and coexistence of the phenotypic diversity of insectivore foraging morphologies in species-rich communities, based on their extraordinary food-resource specializations. Specifically, we develop the Biotic Challenge Hypothesis to explain the evolution of these specializations, and we provide preliminary evidence in support of this hypothesis based on a synopsis of both Neotropical insectivore specializations by family and arthropod antipredator adaptations by category. We argue that, from the perspective of tropical insectivorous birds, and particularly in the most species-rich, mainland Neotropical communities, the environment is an arthropod desert. Coexistence with all of the other insectivores requires feeding specialization to compete exploitatively and diffusely against evolutionarily diverse species and far less frequently against sister species. The arthropod desert arises primarily because of (1) the tactical diversity of arthropod predators as insectivore competitors and (2) the evolutionary arms races involving arthropod predators with their prey, which render many arthropods inaccessible to most insectivorous predators. Our idea provides an explicit mechanism for pervasive, diffuse tropical interspecific competition, for evolutionary specialization, and for positive feedback on speciation rates at low latitudes, thereby generating new predictions and insights into tropical life histories and the Latitudinal Diversity Gradient. Other recent ideas concerning the coexistence of Neotropical insectivores, including positive species interactions within mixed species flocks, are recognized and evaluated. We discuss ways to test predictions resulting from the new view of communities developed here, including a case study of diet specialization by Costa Rican tyrannid flycatchers. Our synthesis of the origin and nature of Neotropical insectivore communities injects new life into the “zombie” idea that evolution works differently in the species-rich tropics.
Silence is sexy: soundscape complexity alters mate choice in túngara frogs
Authors: Coss Derek A , Hunter Kimberly L , Taylor Ryan C
Published: September 2020

Many animals acoustically communicate in large aggregations, producing biotic soundscapes. In turn, these natural soundscapes can influence the efficacy of animal communication, yet little is known about how variation in soundscape interferes with animals that communicate acoustically. We quantified this variation by analyzing natural soundscapes with the mid-frequency cover index and by measuring the frequency ranges and call rates of the most common acoustically communicating species. We then tested female mate choice in the túngara frog (Physalaemus pustulosus) in varying types of background chorus noise. We broadcast two natural túngara frog calls as a stimulus and altered the densities (duty cycles) of natural calls from conspecifics and heterospecifics to form the different types of chorus noise. During both conspecific and heterospecific chorus noise treatments, females demonstrated similar preferences for advertisement calls at low and mid noise densities but failed to express a preference in the presence of high noise density. Our data also suggest that nights with high densities of chorus noise from conspecifics and heterospecifics are common in some breeding ponds, and on nights with high noise density, the soundscape plays an important role diminishing the accuracy of female decision-making.
Evaluation of Orthogonal Testing Algorithm for Detection of SARS-CoV-2 IgG Antibodies
Authors: Xu Gang , Emanuel Anthony J , Nadig Satish , Mehrotra Shikhar , Caddell Brittany A , Curry Scott R , Nolte Frederick S , Babic Nikolina
Published: September 2020

Background

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody testing is an important tool in assessment of pandemic progress, contact tracing, and identification of recovered coronavirus disease 2019 (COVID-19) patients. We evaluated an orthogonal testing algorithm (OTA) to improve test specificity in these use cases.

Methods

A two-step OTA was applied where individuals who initially tested positive were tested with a second test. The first-line test, detecting IgG antibodies to the viral nucleocapsid protein, was validated in 130 samples and the second-line test, detecting IgG antibodies to the viral spike protein in 148 samples. The OTA was evaluated in 4333 clinical patient specimens. The seropositivity rates relative to the SARS-CoV-2 PCR positivity rates were evaluated from our entire patient population data (n = 5102).

Results

The first-line test resulted in a clinical sensitivity of 96.4% (95% CI; 82.3% to 99.4%), and specificity of 99.0% (95% CI; 94.7% to 99.8%), whereas the second-line test had a sensitivity of 100% (95% CI; 87.1% to 100%) and specificity of 98.4% (95% CI; 94.2% to 99.5%). Using the OTA, 78/98 (80%) of initially positive SARS-CoV-2 IgG results were confirmed with a second-line test, while 11/42 (26%) of previously diagnosed COVID-19 patients had no detectable antibodies as long as 94 days post PCR diagnosis.

Conclusion

Our results show that an OTA can be used to identify patients who require further follow-up due to potential SARS CoV-2 IgG false positive results. In addition, serological testing may not be sufficiently sensitive to reliably detect prior COVID-19 infection.
Ovipositional Behavior of the Egg Parasitoid Gryon pennsylvanicum (Hymenoptera: Scelionidae) on Two Squash Bug Species Anasa tristis (Hemiptera: Coreidae) and Anasa armigera: Effects of Parasitoid Density, Nutrition, and Host Egg Chorion on Parasitism Rates
Authors: Cornelius Mary L , Vinyard Bryan T , Mowery Joseph D , Hu Jing S
Published: September 2020

This study examined the ovipositional behavior of Gryon pennsylvanicum Ashmead (Hymenoptera: Scelionidae) on egg masses of two squash bug species Anasa tristis DeGeer and Anasa armigera Say (Hemiptera: Coreidae) by evaluating how parasitoid density and access to nutrition influenced percent parasitism on egg masses of different sizes in laboratory tests. When three parasitoids were exposed to A. tristis egg masses with only three to five eggs, 72.7% of parasitoids became trapped in the eggs and failed to emerge successfully. These results suggest that competition between larvae within the egg may have reduced the fitness of the surviving parasitoid. Continual access to honey water did not significantly influence parasitism rates on A. armigera egg masses and only increased parasitism on A. tristis egg masses with 20–25 eggs. Overall, parasitism rates were higher on A. armigera egg masses than on A. tristis egg masses, and parasitoids were more likely to emerge successfully from A. armigera eggs than from A. tristis eggs. Parasitoids spent the same amount of time probing eggs of the two species, but they spent significantly more time drilling into A. tristis eggs than A. armigera eggs. Measurements taken using transmission electron microscopy determined that the average combined width of the epicuticle and exocuticle of the egg chorion was significantly greater for A. tristis eggs than for A. armigera eggs. This difference may account for the lower rates of parasitism and parasitoid emergence and for the increased time spent drilling into A. tristis eggs compared with A. armigera eggs.
Multi-alleles predict primary non-response to infliximab therapy in Crohn’s disease
Authors: Zhang Cai-Bin , Tang Jian , Wang Xue-Ding , Lyu Kun-Sheng , Huang Min , Gao Xiang
Published: September 2020

Background

Infliximab (IFX) is the first-line treatment for patients with Crohn’s disease (CD) and is noted for its relatively high cost. The therapeutic efficacy of IFX has noticeable individual differences. Known single-gene polymorphisms (SNPs) are inadequate for predicting non-response to IFX. In this study, we aimed to identify new genetic factors associated with IFX-therapy failure and to predict non-response to IFX by developing a multivariate predictive model.

Methods

In this retrospective study, we collected and analysed the data of Chinese patients with CD who received IFX therapy at one hospital between June 2013 and June 2019. Primary non-response (PNR) and non-durable response (NDR) were evaluated using a simple endoscopic score for CD (SES-CD). A total of 125 SNPs within 44 genes were genotyped. A multivariate logistic-regression model was established to predict non-response to IFX. An area-under-the-receiver-operating-characteristics curve (AUROC) was applied to evaluate the predictive model performance.

Results

Forty-two of 206 (20.4%) patients experienced PNR and 15 of 159 (9.4%) patients experienced NDR. Nine SNPs were associated with PNR (P < 0.05). A PNR predictive model was established, incorporating 2-week high-sensitivity C-reactive protein (hs-CRP), rs61886887, rs61740234, rs357291, rs2269330, and rs111504845, and the AUROC on training and testing data sets were 0.818 (P < 0.001) and 0.888 (P < 0.001), respectively. At week 14, hs-CRP levels ≥ 2.25 mg/L were significantly associated with NDR (AUROC = 0.815, P < 0.001). PNR-associated SNPs were not mutually associated with NDR, suggesting distinct mechanisms between PNR and NDR.

Conclusion

Genetic polymorphisms are significantly associated with response to IFX among Chinese CD patients.
Intracardiac extension of chondroblastic osteosarcoma
Authors: Madison Mackenzie K , Matthews Caleb R , Lee Lawrence S
Published: September 2020

Intravascular tumour extension invading the intracardiac space is rarely seen with osteosarcoma. We present a patient with a history of previously resected pelvic osteosarcoma who was later found to have a local recurrence with continuous intravascular extension from the right femoral vein to the right atrium. Preoperative imaging studies initially described extensive thrombus burden, and a multidisciplinary approach involving open and percutaneous thrombectomy was planned. Intraoperative inspection and pathological analysis revealed unresectable malignant solid tumour rather than thrombus. Though exceedingly rare, the possibility of metastatic tumour must be considered when planning treatment strategies for these patients.
Continuity of Weighted Operators, MuckenhouptApWeights, and Steklov Problem for Orthogonal Polynomials
Authors: Alexis Michel , Aptekarev Alexander , Denisov Sergey
Published: September 2020

We consider weighted operators acting on $L^p({\mathbb{R}}^d)$ and show that they depend continuously on the weight $w\in A_p({\mathbb{R}}^d)$ in the operator topology. Then, we use this result to estimate $L^p_w({\mathbb{T}})$ norm of polynomials orthogonal on the unit circle when the weight $w$ belongs to Muckenhoupt class $A_2({\mathbb{T}})$ and $p>2$. The asymptotics of the polynomial entropy is obtained as an application.
Environmental and Aerosolized Severe Acute Respiratory Syndrome Coronavirus 2 Among Hospitalized Coronavirus Disease 2019 Patients
Authors: Binder Raquel A , Alarja Natalie A , Robie Emily R , Kochek Kara E , Xiu Leshan , Rocha-Melogno Lucas , Abdelgadir Anfal , Goli Sumana V , Farrell Amanda S , Coleman Kristen K , Turner Abigail L , Lautredou Cassandra C , Lednicky John A , Lee Mark J , Polage Christopher R , Simmons Ryan A , Deshusses Marc A , Anderson Benjamin D , Gray Gregory C
Published: September 2020

During April and May 2020, we studied 20 patients hospitalized with coronavirus disease 2019 (COVID-19), their hospital rooms (fomites and aerosols), and their close contacts for molecular and culture evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Among >400 samples, we found molecular evidence of virus in most sample types, especially the nasopharyngeal (NP), saliva, and fecal samples, but the prevalence of molecular positivity among fomites and aerosols was low. The agreement between NP swab and saliva positivity was high (89.5%; κ = 0.79). Two NP swabs collected from patients on days 1 and 7 post–symptom onset had evidence of infectious virus (2 passages over 14 days in Vero E6 cells). In summary, the low molecular prevalence and lack of viable SARS-CoV-2 virus in fomites and air samples implied low nosocomial risk of SARS-CoV-2 transmission through inanimate objects or aerosols.
ATG16L1 negatively regulates RICK/RIP2-mediated innate immune responses
Authors: Honjo Hajime , Watanabe Tomohiro , Arai Yasuyuki , Kamata Ken , Minaga Kosuke , Komeda Yoriaki , Yamashita Kouhei , Kudo Masatoshi
Published: September 2020

Polymorphisms in the autophagy-related protein 16 like 1 (ATG16L1) and nucleotide-binding oligomerization domain 2 (NOD2) genes are associated with Crohn’s disease (CD). Impaired interaction between ATG16L1 and NOD2 underlies CD immunopathogenesis. Although activation of the receptor-interacting serine–threonine kinase (RICK, also known as RIP2), a downstream signaling molecule for NOD2 and multiple toll-like receptors (TLRs), plays a pathogenic role in the development of inflammatory bowel disease, the molecular interaction between ATG16L1 and RICK/RIP2 remains poorly understood. In this study, we examined the physical interaction between ATG16L1 and RICK/RIP2 in human embryonic kidney 293 cells and human monocyte-derived dendritic cells (DCs) expressing excessive and endogenous levels of these proteins, respectively. We established that ATG16L1 binds to RICK/RIP2 kinase domain and negatively regulates TLR2-mediated nuclear factor-kappa B (NF-κB) activation and pro-inflammatory cytokine responses by inhibiting the interaction between TLR2 and RICK/RIP2. Binding of ATG16L1 to RICK/RIP2 suppressed NF-κB activation by down-regulating RICK/RIP2 polyubiquitination. Notably, the percentage of colonic DCs expressing ATG16L1 inversely correlated with IL-6 and TNF-α expression levels in the colon of CD patients. These data suggest that the interaction between ATG16L1 and RICK/RIP2 maintains intestinal homeostasis via the down-regulation of TLR-mediated pro-inflammatory cytokine responses.
The Natural History of Severe Acute Respiratory Syndrome Coronavirus 2–Related Multisystem Inflammatory Syndrome in Children: A Systematic Review
Authors: Aronoff Stephen C , Hall Ashleigh , Del Vecchio Michael T
Published: September 2020

Background

The clinical manifestations and natural history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)–related multisystem inflammatory syndrome in children (MIS-C) are poorly defined. Using a systematic review of individual cases and case series and collating elements of the clinical course, the objective of this study was to provide a detailed clinical description and natural history of MIS-C.

Methods

Case reports and series of MIS-C were recovered from repeated MEDLINE searches, a single EMBASE search, and table of contents reviews of major general medicine and pediatric journals performed between June 3 and July 23, 2020. Fever, evidence of inflammation, and evidence of organ dysfunction were required for inclusion.

Results

MEDLINE and EMBASE searches produced 129 articles, and 10 articles were identified from journal contents or article bibliographies; 16 reports describing 505 children with MIS-C comprise this review. Thirty-two children (14.7%) had negative results for SARS-CoV-2 by nucleic acid and/or antibody testing. The weighted median age was 9 years (6 months to 20 years). Clinical findings included fever (100%), gastrointestinal symptoms (88.0%), rash (59.2%), conjunctivitis (50.0%), cheilitis/ “strawberry tongue” (55.7%), or extremity edema/erythema (47.5%). Median serum C-reactive protein, ferritin, fibrinogen, and D-dimer concentrations were above the normal range. Intravenous gammaglobulin (78.1%) and methylprednisolone/prednisone (57.6%) were the most common therapeutic interventions; immunomodulation was used in 24.3% of cases. Myocardial dysfunction requiring ionotropic support (57.4%) plus extracorporeal membrane oxygenation (5.3%), respiratory distress requiring mechanical ventilation (26.1%), and acute kidney injury (11.9%) were the major complications; anticoagulation was used commonly (54.4%), but thrombotic events occurred rarely (3.5%). Seven (1.4%) children died.

Conclusions

MIS-C following SARS-CoV-2 infection frequently presents with gastrointestinal complaints and/or rash; conjunctivitis, cheilitis, and/or extremity changes also occur frequently. Serious complications occur frequently and respond to aggressive supportive therapy.
Extrauterine adenomyoma located in the inguinal region: a case report of a 44-year-old woman
Authors: Ramphal Winesh , Peters Chloé M L , Alcalá Luthy S M , van Hamont Dennis , Gobardhan Paul D
Published: September 2020

Adenomyomas are benign tumours made of smooth muscle cells, endometrial glands and stroma. An extrauterine location is extremely rare with an unknown pathogenesis. Preoperative diagnosis is challenging and pathologic examination is necessary to confirm the diagnosis. Here we present a case report of a 44-year-old woman with a painful non-reducible mass in the right inguinal region without fever or other alarming symptoms 2 months after a laparoscopic hysterectomy. She was treated with a surgical resection of the mass. Extrauterine adenomyoma is a very uncommon entity. Preoperative workup is challenging, as confirmation of the diagnosis can only be achieved by histopathological analysis following surgical excision.
Digital arts in Latin America: A report on the archival history of intersections in art and technology in Latin America
Authors: Thompson Reynaldo , Mukhopadhyay Tirtha P
Published: September 2020

A pressing problem in archival preservation of information on electronic art, and any possible virtual conservation of such artifacts in Latin America, is the lack of strategic initiatives in the field. Unfortunately, a certain so-called ‘history of digital art’ has not been constructed in the southern continent; neither is any ‘history of digital art in Latin America’ valorized per se in the literature on contemporary art. The creation of databases and sets is inevitable as Latin America transforms into an economic power. Intelligent and user-friendly archival platforms are urgently needed. The potential of a 5G empowered mining for retrieval of dynamic contents in new media arts is immense and would further point to the aesthetic needs of the future.
Pre-supernova activity as a possible explanation of the peculiar properties of Type IIP supernova 2009kf
Authors: Ouchi Ryoma , Maeda Keiichi
Published: September 2020

SN 2009kf is an exceptionally bright Type IIP supernova (SN IIP) discovered by the Pan-STARRS 1 survey. The V-band magnitude in the plateau phase is MV = −18.4 mag, which is much brighter than that for typical SNe IIP. We propose that its unusual properties can be naturally explained if we assume that there was a super-Eddington energy injection into the envelope in the last few years of the evolution before the SN explosion. Using a progenitor model with such a pre-SN energy injection, we can fit the observational data of SN 2009kf with a reasonable explosion energy of Eexp = 2.8 × 1051 erg and 56Ni mass of 0.25 M⊙. Specifically, we injected the energy into the envelope at a constant rate of 3.0 × 1039 erg s−1 in the last 3.0 yr of evolution before the core collapse. We propose that some unusually bright SNe IIP might result from pre-SN energy injection into the envelope.
The detailed structure and the onset of galaxy formation in low-mass gaseous dark matter haloes
Authors: Benitez-Llambay Alejandro , Frenk Carlos
Published: September 2020

We present a model for the formation of the first galaxies before and after the reionization of hydrogen in the early universe. In this model, galaxy formation can only take place in dark matter haloes whose mass exceeds a redshift-dependent critical value, which, before reionization, is equal (in the simplest case) to the mass at which atomic hydrogen cooling becomes effective and, after reionization, is equal to the mass above which gas cannot remain in hydrostatic equilibrium. We define the Halo Occupation Fraction (HOF) as the fraction of haloes that host a luminous galaxy as a function of halo mass. The HOF is established by the interplay between the evolution of the critical mass and the assembly history of haloes and depends on three factors: the minimum halo mass for galaxy formation before reionization, the redshift of reionization, and the intensity of the (evolving) external photoheating rate. Our fiducial model predicts a cutoff in the galaxy mass function at a present-day halo mass, $M_{200} \sim 3\times 10^{8} \, \mathrm{M}_{\odot }$; 100 per cent occupation at $M_{200} \gt 5\times 10^9 \, \mathrm{M}_{\odot }$; and a population of starless gaseous haloes of present-day mass in the range 106 ≲ M200/M⊙ ≲ 5 × 109, in which the gas is in thermal equilibrium with the ultraviolet background radiation and in hydrostatic equilibrium in the gravitational potential of the halo. The transition between HOF = 0 and HOF = 1 reflects the stochastic nature of halo mass growth. We explore how these characteristic masses vary with model assumptions and parameter values. The results of our model are in excellent agreement with cosmological hydrodynamic simulations of galaxy formation.
Reliability of Using the Proposed International Consensus Video Signs of Potential Concussion for National Rugby League Head Impact Events
Authors: Gardner Andrew J
Published: September 2020

BACKGROUND

Consensus on the definition of extant video signs of concussion have recently been proposed by representatives of international sporting codes for global consistency across professional leagues.

OBJECTIVE

To review the reliability of the proposed international consensus video signs of concussion in National Rugby League (NRL) head impact events (HIEs).

METHODS

The video signs of concussion were coded for every HIE during the 2019 NRL season. Coding was conducted blinded to the concussion status. Frequency, sensitivity, specificity, and a receiver operating characteristic curve were calculated.

RESULTS

There were 943 HIEs identified over the 2019 NRL season, of which 106 resulted in a diagnosed concussion. The most frequently observed video sign in concussed athletes was blank/vacant look (54%), which was also the most sensitive video sign (0.54, CI: 0.44-0.63), while the most specific was tonic posturing (0.99, CI: 0.99-1.00). In 43.4% of diagnosed concussions none of the 6 video signs were present. The 6 video signs demonstrated a “fair” ability to discriminate between concussion and nonconcussion HIEs (area under the curve = 0.76).

CONCLUSION

International consensus agreement between collision sports for extant video signs of concussion and the definition of those extant video signs are clinically important. The selection of signs requires rigorous assessment to examine their predictive value across all sports and within individual sports, and to determine further video signs to compliment and improve the identification of possible concussion events within various sports. The current study demonstrated that, for NRL-related HIEs, the diagnostic accuracy of video signs varies.
Pitch, Tone, and Note
Authors: Parkhurst Bryan , Hammel Stephan
Published: September 2020

This chapter recasts the terms “Pitch,” “Tone,” and “Note” as far-reaching historical-materialist categories, with a view to expounding and defending the following ideas: (1) there is an immanent developmental logic to the way that Pitch, Tone, and Note have changed over time; (2) this trajectory of development is open to empirical investigation and to explanation anchored in the concrete features of human practices and institutions and their environing natural and social contexts; and (3) this developmental dynamic has had, and continues to have, appreciable consequences for many aspects and types of “musicking.” After setting up a Marxian framework, we then put these categories to explanatory work in a series of three case studies concerning the development of music’s “forces of production.” The origins of music printing, the evolution of piano manufacture, and the birth of sound synthesis are used to reveal causal linkages between changes in musical practice and trends in capitalist development.
Beneath Improvisation
Authors: Iyer Vijay
Published: September 2020

Improvisation has been construed as Western art music’s Other. This chapter urges music theorists to take the consequences of this configuration seriously. The decision to exclude improvisation as inherently unstable is not neutral, but is bound up with the endemic racism that has characterized social relations in the West and that is being brought to the fore in Black Lives Matter and other recent social and political movements. Traditional music theory is not immune from such institutional racism—its insistence on normative musical behaviors is founded on the (white) phallogocentrism of Western thought. Does the resurgent academic interest in improvisation offer a way out? No, at least not as it is currently studied. Even an apparently impartial approach such as cognitive science is not neutral; perception is colored by race. To get anywhere, this chapter argues, improvisation studies must take difference seriously. Important impetus for a more inclusive critical model comes from such fields as Black studies, Women’s studies, subaltern studies, queer studies, and disability studies.
The Zagros Mountains acting as a natural barrier to gene flow in the Middle East: more evidence from the evolutionary history of spiny-tailed lizards (Uromasticinae:Saara)
Authors: Ghaedi Zeinab , Badri Sahar , Saberi-Pirooz Reihaneh , Vaissi Somaye , Javidkar Mohammad , Ahmadzadeh Faraham
Published: September 2020

We investigated the phylogeographic structure of the genus Saara and studied whether the Zagros Mountain ranges influence the gene flow and dispersal at the landscape scale between the Iranian Saara species, including S. asmussi in the central Iranian plateau and S. loricata in the Mesopotamian lowlands. Phylogenetic analyses clearly show three well-supported species, including S. loricata, S. asmussi and S. hardwickii, that are distinct from Uromastyx species. The S-DIVA and BBM analyses demonstrate that species of Saara originated from an ancestor somewhere in the Iranian Plateau and then dispersed to its current geographical range. Our results indicate that the separation of S. loricata from S. asmussi coincides with the orogenic events of the Zagros Mountains during the Pliocene, and thus it may show a vicariance event. Diversification within populations of S. loricata and S. assmussi are estimated to have occurred during the Pleistocene. The haplotype network indicates one haplogroup for each of the Iranian Saara species. Population genetic analyses shows signals of demographic expansions at the beginning of the Holocene for S. loricata. Our results support the hypothesis that the Zagros Mountains act as a barrier for gene flow and Quaternary climatic oscillations affected intraspecific genetic divergences of S. loricata and S. asmussi.
Survey and Genetic Analysis of Demethylation Inhibitor Fungicide Resistance in Monilinia fructicola From Michigan Orchards
Authors: Lesniak Kimberley E. , Peng Jingyu , Proffer Tyre J. , Outwater Cory A. , Eldred Lauren I. , Rothwell Nikki L. , Sundin George W.
Published: September 2020

Resistance to sterol demethylation inhibitor (DMI) fungicides in Monilinia fructicola, causal agent of brown rot of stone fruit, has been reported in the southeastern and eastern United States and in Brazil. DMI resistance of some M. fructicola isolates, in particular those recovered from the southeastern United States, is associated with a sequence element termed “Mona” that causes overexpression of the cytochrome demethylase target gene MfCYP51. In this study, we conducted statewide surveys of Michigan stone fruit orchards from 2009 to 2011 and in 2019, and we determined the sensitivity to propiconazole of a total of 813 isolates of M. fructicola. A total of 80.7% of Michigan isolates were characterized as resistant to propiconazole by relative growth assays, but the Mona insert was not uniformly detected and was present in some isolates that were not characterized as DMI resistant. Gene expression assays indicated that elevated expression of MfCYP51 was only weakly correlated with DMI resistance in M. fructicola isolates from Michigan, and there was no obvious correlation between the presence of the Mona element and elevated expression of MfCYP51. However, sequence analysis of MfCYP51 from 25 DMI-resistant isolates did not reveal any point mutations that could be correlated with resistance. Amplification and sequencing upstream of MfCYP51 resulted in detection of DNA insertions in a wide range of isolates typed by DMI phenotype and the presence of Mona or other unique sequences. The function of these unique sequences or their presence upstream of MfCYP51 cannot be correlated to a DMI-resistant genotype at this time. Our results indicate that DMI resistance was established in Michigan populations of M. fructicola by 2009 to 2011, and that relative resistance levels have continued to increase to the point that practical resistance is present in most orchards. In addition, the presence of the Mona insert is not a marker for identifying DMI-resistant isolates of M. fructicola in Michigan.
An Online Asynchronous Physical Assessment Lab (OAPAL) for Graduate Nursing Students Using Low-Fidelity Simulation With Peer Feedback
Authors: Webber-Ritchey Kashica J. , Badowski Donna , Gibbons Lisa
Published: September 2020

Physical assessment courses typically include a didactic component and a skills laboratory component. It is a challenge to create laboratory components in fully online nursing courses. This article reports on the use of an online asynchronous physical assessment laboratory using low-fidelity simulation with peer feedback to teach physical assessment skills to postlicensure nursing students in a fully online advanced health assessment course within an RN to MS program. Students found the online asynchronous physical assessment laboratory favorable, relevant, and engaging and believed it advanced their current skills.
Update on antimalarials and systemic lupus erythematosus
Authors: Ruiz-Irastorza Guillermo , Martín-Iglesias Daniel , Soto-Peleteiro Adriana
Published: September 2020

Purpose of review

The purpose of this review is highlighting the most recent evidence on the clinical efficacy and toxicity of antimalarials in systemic lupus erythematosus (SLE).

Recent findings

New data confirm the effects of antimalarials in preventing SLE activity, damage and infections and in decreasing mortality. An important reduction in use of health resources is related to continued antimalarial use. Hydroxychloroquine (HCQ) may prevent preeclampsia in pregnant women with SLE. HCQ ocular toxicity is infrequent and could be associated with blood levels. Gastrointestinal and skin toxicity are underrecognized and could influence adherence. Prolongation of QT interval is extremely unusual with HCQ. Doses of HCQ of 200 mg/day seem to offer a good efficacy/toxicity balance. HCQ protection against herpes zoster and Pneumocystis jirovecii infection has been shown. On the contrary, HCQ prescription by doctors and adherence by patients are both under recommended standards. The recent coronavirus disease 2019 pandemic has resulted in a significant shortage of HCQ in many countries with possible consequences in the correct treatment of lupus patients.

Recent evidence reinforces the central role of HCQ in SLE therapy. The reduction in activity, damage accrual and mortality is consistent across studies, countries and ethnical groups. On the contrary, and despite the well established beneficial effects of prolonged regular HCQ therapy, many SLE patients do never take this drug or it is eventually stopped in the setting of severe flares, pregnancy or presumed toxicity. Every effort must be made to assure the correct prescription of HCQ and not to withdraw the drug unless unequivocal signs of toxicity are present.
Calcinosis: insights from other calcinoses
Authors: Tsakali Sofia Serena , Shanahan Catherine M.
Published: September 2020

Purpose of review

This review examines the current knowledge and recent developments in the field of vascular calcification focusing on the emerging role of senescence and inflammation in driving this disorder and exploring the overlap and relevance of these pathways to calcinosis in rheumatic disease.

Recent findings

Vascular calcification is an age-associated disorder. Recent studies have identified DNA damage, cellular senescence and consequent inflammation as key drivers of vascular smooth muscle cell osteogenic change and mineralization. Similar ageing and inflammatory factors are associated with calcinosis in rheumatic disease and some are targets of experimental drugs currently undergoing clinical trials.

Calcinosis in the vascular system and in rheumatic disease share similarities in terms of biomineralization and cardiovascular outcomes. Although research into the role of senescence and inflammation has recently been advanced in vascular calcification, little is known about the mechanistic role of inflammation in calcinosis in rheumatic disease. This review explores whether lessons from one calcinosis can be transferred and applied to the other to provide further insights and inform treatment strategies.
Augmented Reality-assisted Pedicle Instrumentation
Authors: Urakov Timur M.
Published: September 2020

Study Design.

Laboratory investigation with phantom spine models.

Objectives.

The aim of this study was to demonstrate the ability of Augmented Reality system to track instruments from different companies without major modifications.

Summary of Background Data.

Augmented Reality is an emergent technology with applications in industrial, military, gaming, and medical fields. AR applications in Spine surgery are actively being developed. Features of headpiece ergonomics, digital processing power, intuitive interface, and reliable accuracy are being optimized for successful adaptation of technology into the field. System versatility across various instrumentation sets is important for cost-effectiveness and efficiency in application.

Methods.

In this project, five phantom spine models were instrumented L1-S1 with pedicle screws from five major companies. AR assistance was used for all. Each screwdriver was equipped with a generic 3D printed navigation marker for tracking.

Results.

Every instrumentation set was successfully paired with AR navigation imaging. Sixty pedicle screws were inserted with an average time of 1.6 min/screw. There was an evidence of learning curve with fastest time achieved of 1 min/screw. All five systems had equivocal radiographic outcomes. There were two breached screws (3%).

Conclusion.

Any currently available instrumentation set can readily pair for tracking with Augmented Reality system. Active tracking of the drivers allowed for improved accuracy making AR system very attractive as an adjunct to the current instrumentation techniques.

Level of Evidence: 3
Surgical Outcomes Following Laminectomy With Fusion Versus Laminectomy Alone in Patients With Degenerative Cervical Myelopathy
Authors: Kotter Mark R.N. , Tetreault Lindsay , Badhiwala Jetan H. , Wilson Jefferson R. , Arnold Paul M. , Bartels Ronald , Barbagallo Giuseppe , Kopiar Branko , Fehlings Michael G.
Published: September 2020

Study Design..

Post-hoc analysis of a prospective observational cohort study.

Objective..

To compare clinical outcomes following laminectomy and fusion versus laminectomy alone in an international series of individuals suffering from degenerative cervical myelopathy (DCM).

Summary of Background Data..

Significant controversy exists regarding the role of instrumented fusion in the context of posterior surgical decompression for DCM. A previous study comparing laminectomy and fusion with laminoplasty showed no differences in outcomes between groups after adjusting for preoperative characteristics.

Methods..

Based on the operation they received, 208 of the 757 patients prospectively enrolled in the AO Spine North America or International studies at 26 global sites were included in the present study. Twenty-two patients were treated with laminectomy alone and 186 received a laminectomy with fusion. Patients were evaluated using the modified Japanese Orthopedic Association scale (mJOA), Nurick score, Neck Disability Index, and SF36 quality of life measure. Baseline and surgical characteristics were compared using a t test for continuous variables and a chi-square test for categorical variables. A mixed model analytic approach was used to evaluate differences in outcomes at 24 months between patients undergoing laminectomy and fusion versus laminectomy alone.

Results..

Surgical cohorts were comparable in terms of preoperative patient characteristics. Patients undergoing laminectomy with instrumented fusion had a significantly longer operative duration (P < 0.0001, 231.44 vs. 107.10 min) but a comparable length of hospital stay. In terms of outcomes, patients treated with laminectomy with fusion exhibited clinically meaningful improvements (in functional impairmentΔmJOA = 2.48, ΔNurick = 1.19), whereas those who underwent a laminectomy without fusion did not (ΔmJOA = 0.78; ΔNurick = 0.29). There were significant differences between surgical cohorts in the change in mJOA and Nurick scores from preoperative to 24-months postoperative (mJOA: −1.70, P = 0.0266; Nurick: −0.90, P = 0.0241). The rate of perioperative complications was comparable (P = 0.879).

Conclusion..

Our findings suggest that cervical laminectomy with instrumented fusion is more effective than laminectomy alone at improving functional impairment in patients with DCM. These results warrant confirmation in larger prospective comparative studies.

Level of Evidence: 2
Nurses and Churches Are Essential to Postdisaster Recovery
Authors: Kiser Erin
Published: September 2020

Two nurses, a mother and daughter, each participated in disaster relief efforts after Hurricane Andrew in 1992 and Hurricane Dorian in 2019. In recounting their experiences, both nurses demonstrate the vital contributions nurses can make at the sites of disasters. The invaluable role of churches in contributing to the disaster recovery effort is also described.
Assess the Pulse of Your Morning
Authors: Logan Jennette S.
Published: September 2020

Global pandemics and societal unrest add greater weight to nurses' workloads and personal coping abilities. Appropriate self-care includes assessing one's physical, emotional, and spiritual pulse. Taking needed breaks for rest and inner nourishment is essential.
Outer Retinal Abnormalities in a Patient with Danon Disease
Authors: Hasegawa Ayaka , Noda Kousuke , Fujiya Akio , Hirooka Kiriko , Anzai Toshihisa , Ishida Susumu
Published: September 2020

Purpose:

To report outer retinal abnormalities evaluated using high-resolution imaging modalities in a patient with Danon disease.

Methods:

Case report.

Results:

A 26-year-old woman, diagnosed with Danon disease based on genetic testing, was referred to our department for further evaluation of ocular findings. Her best-corrected VA was 20/20, and color vision was normal. Fundus examination revealed pigmentary changes consisting of mottled depigmentation and pigmentation in the peripheral retina of both eyes. Spectral-domain optical coherence tomography revealed disruptions of the ellipsoid and interdigitation zones, irregularity of the retinal pigment epithelium, and hyperreflectivity of the outer nuclear layer. In addition, an adaptive optics retinal camera demonstrated the ambiguous macular cone mosaic pattern.

Conclusion:

Danon disease is caused by a primary deficiency in lysosomal associated membrane protein 2, an important constituent of the lysosomal membrane that plays a crucial role in the process of autophagy. It is possible that the findings of spectral-domain optical coherence tomography and adaptive optics retinal camera are early changes associated with the accumulation of autophagosomes and/or phagosomes due to lysosomal associated membrane protein 2 dysfunction in the photoreceptors, eventually followed by outer retinal degeneration, such as thinning of both the photoreceptor and retinal pigment epithelium layers at the fovea.