bluuebunny/crossref_metadata_2025 huggingface dataset:
Vector‐valued generalized Ornstein–Uhlenbeck processes: Properties and parameter estimation
Authors: Voutilainen Marko , Viitasaari Lauri , Ilmonen Pauliina , Torres Soledad , Tudor Ciprian
Published: July 2021

Generalizations of the Ornstein–Uhlenbeck process defined through Langevin equations, such as fractional Ornstein–Uhlenbeck processes, have recently received a lot of attention. However, most of the literature focuses on the one‐dimensional case with Gaussian noise. In particular, estimation of the unknown parameter is widely studied under Gaussian stationary increment noise. In this article, we consider estimation of the unknown model parameter in the multidimensional version of the Langevin equation, where the parameter is a matrix and the noise is a general, not necessarily Gaussian, vector‐valued process with stationary increments. Based on algebraic Riccati equations, we construct an estimator for the parameter matrix. Moreover, we prove the consistency of the estimator and derive its limiting distribution under natural assumptions. In addition, to motivate our work, we prove that the Langevin equation characterizes essentially all multidimensional stationary processes.
Characterization of the novel HLA allele, HLA‐DRB1*08:76
Authors: Lin Feng‐Qiu , Zhang Xu , Li Xiao‐Feng , Li Jian‐Ping
Published: July 2021

HLA‐DRB1*08:76 is a novel allele differing by a single nucleotide from the HLA‐DRB1*08:03:02 allele.
Prognostic significance of high circulating sHLA‐G in ovarian carcinoma
Authors: Babay Wafa , Boujelbene Nadia , Ben Yahia Hamza , Bortolotti Daria , Zemni Ines , Ouzari Hadda‐Imene , Chelbi Hanene , Mezlini Amel , Rizzo Roberta , Zidi Inès
Published: July 2021

HLA‐G is a non‐classical major histocompatibility complex class Ib molecule. Its expression has been described in various cancer types, including ovarian cancer. HLA‐G molecule has been implicated in immune escape and in progression of ovarian tumor cells. Our goal was to assess if total soluble (s)HLA‐G molecules or HLA‐G5 and sHLA‐G1 isoforms could be considered as circulating ovarian tumor biomarkers, we measured the concentration of these molecules in ovarian carcinoma patients stratified according with their clinicopathological parameters. sHLA‐G, sHLA‐G1 and HLA‐G5 concentrations were dosed in plasma samples by sandwich‐ELISA. The sHLA‐G dimerization was analyzed after immunoprecipitation and SDS‐PAGE migration. Total sHLA‐G and sHLA‐G1 levels were significantly represented in plasma of ovarian carcinoma patients compared to healthy controls. sHLA‐G1 isoform concentration was highly represented in ovarian carcinoma compared to HLA‐G5 isoforms. Additionally, high sHLA‐G molecules have been found in aged patients, as well as in patients with advanced stages, and those with metastatic lymph nodes and those with distant metastasis. Elsewhere, sHLA‐G monomers were highly represented in ovarian carcinoma patients compared to controls. sHLA‐G plasmatic protein was highly represented in ovarian carcinoma. In effect, HLA‐G might be considered as a new checkpoint molecule that could be used to assess progression and recurrence of the disease, thus placing it as a potential biomarker for advanced and complicated ovarian carcinoma.
Understanding and predicting the spatio‐temporal spread of COVID‐19 via integrating diffusive graph embedding and compartmental models
Authors: Zhang Tong , Li Jing
Published: July 2021

In order to find useful intervention strategies for the novel coronavirus (COVID‐19), it is vital to understand how the disease spreads. In this study, we address the modeling of COVID‐19 spread across space and time, which facilitates understanding of the pandemic. We propose a hybrid data‐driven learning approach to capture the mobility‐related spreading mechanism of infectious diseases, utilizing multi‐sourced mobility and attributed data. This study develops a visual analytic approach that identifies and depicts the strength of the transmission pathways of COVID‐19 between areal units by integrating data‐driven deep learning and compartmental epidemic models, thereby engaging stakeholders (e.g., public health officials, managers from transportation agencies) to make informed intervention decisions and enable public messaging. A case study in the state of Colorado, USA was performed to demonstrate the applicability of the proposed transmission modeling approach in understanding the spatio‐temporal spread of COVID‐19 at the neighborhood level. Transmission path maps are presented and analyzed, demonstrating their utility in evaluating the effects of mitigation measures. In addition, integrated embeddings also support daily prediction of infected cases and role analysis of each area unit during the transmission of the virus.
From consistency to flexibility: A simplified database schema for the management of CityJSON 3D city models
Authors: Nys Gilles‐Antoine , Billen Roland
Published: July 2021

The use of 3D city models is now common practice; many large cities have their own digital model. Resilient and sustainable management of these models is necessary in many cases, where an application could evolve over its lifecycle. The complexity of generic modeling standardization is often a limitation for a light and user‐friendly usage and further developments. This article aims to propose an alternative, providing a simplified database schema implemented in document‐oriented storage. Thanks to the use of the NoSQL store, the focus is on flexibility of the data schemas and thus its clarification. In order to aim attention at the compactness in web development, CityJSON has been chosen for the encoding of the 3D city models. Finally, a full‐stack application (persistent storage, consistent edition, and visualization of 3D city models) has been developed to handle the simplified schema and illustrates its capabilities in two practical use cases.
Characterization of C‐26 aminotransferase, indispensable for steroidal glycoalkaloid biosynthesis
Authors: Nakayasu Masaru , Umemoto Naoyuki , Akiyama Ryota , Ohyama Kiyoshi , Lee Hyoung J. , Miyachi Haruka , Watanabe Bunta , Muranaka Toshiya , Saito Kazuki , Sugimoto Yukihiro , Mizutani Masaharu
Published: July 2021

Steroidal glycoalkaloids (SGAs) are toxic specialized metabolites found in members of the Solanaceae, such as Solanum tuberosum (potato) and Solanum lycopersicum (tomato). The major potato SGAs are α‐solanine and α‐chaconine, which are biosynthesized from cholesterol. Previously, we have characterized two cytochrome P450 monooxygenases and a 2‐oxoglutarate‐dependent dioxygenase that function in hydroxylation at the C‐22, C‐26 and C‐16α positions, but the aminotransferase responsible for the introduction of a nitrogen moiety into the steroidal skeleton remains uncharacterized. Here, we show that PGA4 encoding a putative γ‐aminobutyrate aminotransferase is involved in SGA biosynthesis in potatoes. The PGA4 transcript was expressed at high levels in tuber sprouts, in which SGAs are abundant. Silencing the PGA4 gene decreased potato SGA levels and instead caused the accumulation of furostanol saponins. Analysis of the tomato PGA4 ortholog, GAME12, essentially provided the same results. Recombinant PGA4 protein exhibited catalysis of transamination at the C‐26 position of 22‐hydroxy‐26‐oxocholesterol using γ‐aminobutyric acid as an amino donor. Solanum stipuloideum (PI 498120), a tuber‐bearing wild potato species lacking SGA, was found to have a defective PGA4 gene expressing the truncated transcripts, and transformation of PI 498120 with functional PGA4 resulted in the complementation of SGA production. These findings indicate that PGA4 is a key enzyme for transamination in SGA biosynthesis. The disruption of PGA4 function by genome editing will be a viable approach for accumulating valuable steroidal saponins in SGA‐free potatoes.
Risk of transfusion‐transmitted Babesia microti in Canada
Authors: O'Brien Sheila F. , Drews Steven J. , Yi Qi‐Long , Bloch Evan M. , Ogden Nicholas H. , Koffi Jules K. , Lindsay Leslie Robbin , Gregoire Yves , Delage Gilles
Published: July 2021

Background

Babesia microti has gained a foothold in Canada as tick vectors become established in broader geographic areas. B. microti infection is associated with mild or no symptoms in healthy individuals but is transfusion‐transmissible and can be fatal in immunocompromised individuals. This is the first estimate of clinically significant transfusion‐transmitted babesiosis (TTB) risk in Canada.

Study design and methods

The proportion of B. microti‐antibody (AB)/nucleic acid amplification test (NAT)‐positive whole blood donations was estimated at 5.5% of the proportion of the general population with reported Lyme Disease (also tick‐borne) based on US data. Monte Carlo simulation estimated the number and proportion of infectious red cell units for three scenarios: base, localized incidence (risk in Manitoba only), and donor study informed (prevalence from donor data). The model simulated 1,029,800 donations repeated 100,000 times for each.

Results

In the base scenario 0.5 (0.01, 1.75), B. microti‐NAT‐positive donations would be expected per year, with 0.08 (0, 0.38) recipients suffering clinically significant TTB (1 every 12.5 years). In the localized incidence scenario, there were 0.21(0, 0.7) B. microti‐NAT‐positive donations, with 0.04 (0, 0.14) recipient infections (about 1 every 25 years). In the donor study informed scenario, there were 4.6 (0.3, 15.8) B. microti‐NAT‐positive donations expected, and 0.81 (0.05, 3.14) clinically significant TTB cases per year.

Discussion

The likelihood of clinically relevant TTB is low. Testing would have very little utility in Canada at this time. Ongoing pathogen surveillance in tick vectors is important as B. microti prevalence appears to be slowly increasing in Canada.
Hybrid natural orifice transluminal endoscopy surgery (NOTES) to perform bilateral ovariectomy in mares
Authors: Velloso Alvarez A. , Boone Lindsey , Horzmann Katharine , Hanson R. Reid
Published: July 2021

Objectives

To combine laparoscopic techniques with natural orifice transluminal endoscopic surgery (hybrid NOTES) to minimize number and enlargement of paralumbar laparoscopic portals for bilateral ovariectomy in standing, sedated mares.

Study design

Case series.

Animals

Six horses.

Materials and Methods

Six mares with palpably normal ovaries were restrained in stocks, sedated, and had caudal epidural anesthesia performed. A 7.5 MHz ultrasound probe was used transvaginally to select placement of vaginotomy. An attempt was made to remove both ovaries with 70 cm esophageal forceps through the vaginotomy, while visualized and transected via ipsilateral paralumbar fossa laparoscopic portals. Surgical time, intraoperative, and postoperative complications were recorded. Vaginoscopy was performed at days 0, 3, 7, and 14 postoperatively. After 14 days, mares were euthanized and necropsied.

Results

Hybrid NOTES allowed successful bilateral ovariectomy in all six mares, with a mean surgical time of 70 ± 25 min. In two mares, one ovary was dislodged from the forceps during vaginotomy extraction. Abdominal retrieval of the ovary was successful with reapplication of forceps or a surgeon's hand via vaginotomy. At necropsy, five mares had no adhesions within the abdominal cavity or at the vaginotomy site. One mare in which hand retrieval of the ovary was necessary, developed an adhesion between the bladder and the vaginotomy.

Conclusions

This technique appears to offer a safe alternative for bilateral ovariectomy with minimal postoperative complications.

Clinical Significance

Decreased number and size of paralumbar laparoscopic incisions could decrease complications associated with exteriorization of ovaries through the flank.
Can Social Mobility Alleviate Anxiety? An Empirical Analysis Based on the CGSS
Authors: Han Junhui
Published: July 2021

With the aggravation of social competition, more and more people fall into anxiety, depression and even suicide. How to alleviate individual anxiety and then avoid the spread of social anxiety? Academic circles have been very concerned about the impact of social mobility on individual political attitude, psychology and behavior. Can social mobility alleviate individual anxiety? What is the underlying mechanism? Based on 17192 samples in 2010, 2012, 2013 and 2015 from Chinese General Social Survey (CGSS), the paper attempts to study the impact of social mobility on individual anxiety and the mediating effect of Self assessment on family economic status . The ordered probit regression model showed that the increase of positive mobility distance can alleviate individual anxiety to a certain extent, whether it is intra or inter-generational social mobility. Meamwhile, the higher the score of subjective class identification, the lower the degree of anxiety. The results also showed that self assessment on family economic status has a significant mediating effect on the relationship among social mobility and individual anxiety.
Mathematical modeling and analysis of Covid-19 infection spreads in India with restricted optimal treatment on disease incidence
Authors: Pal Debkumar , Ghosh D , Santra P K , Mahapatra G S
Published: July 2021

This paper presents the current situation and how to minimize its effect in India through a mathematical model of infectious Coronavirus disease (COVID-19). This model consists of six compartments to population classes consisting of susceptible, exposed, home quarantined, government quarantined, infected individuals in treatment, and recovered class. The basic reproduction number is calculated, and the stabilities of the proposed model at the disease-free equilibrium and endemic equilibrium are observed. The next crucial treatment control of the Covid-19 epidemic model is presented in India's situation. An objective function is considered by incorporating the optimal infected individuals and the cost of necessary treatment. Finally, optimal control is achieved that minimizes our anticipated objective function. Numerical observations are presented utilizing MATLAB software to demonstrate the consistency of present-day representation from a realistic standpoint.
Multiple Bifurcations and Complex Responses of Nonlinear Time-Delay Oscillators
Authors: Mao Xiaochen , Lei Fuchen , Li Xingyong , Ding Weijie , Shi Tiantian
Published: July 2021

In this paper, the dynamical properties of multiple van der Pol-Duffing oscillators with time delays are studied. The amplitude death and bifurcation curves in the parameter plane are determined by using the space decomposition method. Different patterns of bifurcated solutions are given on the basis of the symmetric bifurcation theory. The properties of bifurcated solutions are shown by using the norm forms on the center manifold. The interactions of bifurcations are discussed and their dynamical behaviors are shown. An electronic circuit platform is implemented by means of nonlinear circuit and time delay circuit. The revealed behaviors of the circuit reach an agreement with the obtained results. It is shown that the nonlinearity and time delays have great effects on the system performance and can induce interesting and abundant dynamic features.
Uncertainty Quantification of Differential Algebraic Equations Using Polynomial Chaos
Authors: Saha Premjit , Singh Tarunraj , Dargush Gary
Published: July 2021

The focus of this paper is on the use of polynomial chaos (PC) for developing surrogate models for differential algebraic equations (DAEs) with time-invariant uncertainties. Intrusive and nonintrusive approaches to synthesize PC surrogate models are presented including the use of Lagrange interpolation polynomials as basis functions. Unlike ordinary differential equations (ODEs), if the algebraic constraints are a function of the stochastic variable, some initial conditions of the DAEs are also random. A benchmark RLC circuit which is used as a benchmark for linear models is used to illustrate the development of a PC-based surrogate model. A nonlinear example of a simple pendulum also serves as a benchmark to illustrate the potential of the proposed approach. Statistics of the results of the PC models are validated using Monte Carlo (MC) simulations in addition to estimating the evolving probably density functions (PDFs) of the states of the pendulum.
An Advanced Antislip Control Algorithm for Locomotives Under Complex Friction Conditions
Authors: Yang Yunfan , Ling Liang , Zhang Tao , Wang Kaiyun , Zhai Wanming
Published: July 2021

The locomotive wheelsets configured with high-power AC traction motors are very prone to slip under poor friction conditions, which usually impair traction/braking efficiency. To avoid the adverse consequence caused by the conspicuous slipping behaviors of wheels, the antislip control modules are consequently equipped on high-power locomotives. This paper presents an advanced antislip control algorithm for heavy-haul locomotives traveling by complex wheel/rail friction conditions. The proposed antislip control model is implemented in a three-dimensional (3D) heavy-haul train-track coupled dynamics model, in which the real-time estimation of wheel/rail adhesion conditions and relevant optimization adjustment of control threshold values are considered. The wheel/rail dynamic interactions of the heavy-haul locomotive under traction/braking conditions and multifarious friction conditions are investigated. The control effects of the antislip controllers with changeable and constant threshold values are compared. It is shown that the traction/braking loads and friction conditions have a significant effect on wheel/rail interactions. The optimal traction/braking efficiency can be realized by adopting the antislip controller with alterable threshold values.
Implicit Co-Simulation and Solver-Coupling: Efficient Calculation of Interface-Jacobian and Coupling Sensitivities/Gradients
Authors: Kraft J. , Klimmek S. , Meyer T. , Schweizer B.
Published: July 2021

We consider implicit co-simulation and solver-coupling methods, where different subsystems are coupled in time domain in a weak sense. Within such weak coupling approaches, a macro-time grid (communication-time grid) is introduced. Between the macro-time points, the subsystems are integrated independently. The subsystems only exchange information at the macro-time points. To describe the connection between the subsystems, coupling variables have to be defined. For many implicit co-simulation and solver-coupling approaches, an interface-Jacobian (i.e., coupling sensitivities, coupling gradients) is required. The interface-Jacobian describes how certain subsystem state variables at the interface depend on the coupling variables. Concretely, the interface-Jacobian contains partial derivatives of the state variables of the coupling bodies with respect to the coupling variables. Usually, these partial derivatives are calculated numerically by means of a finite difference approach. A calculation of the coupling gradients based on finite differences may entail problems with respect to the proper choice of the perturbation parameters and may therefore cause problems due to ill-conditioning. A second drawback is that additional subsystem integrations with perturbed coupling variables have to be carried out. In this paper, analytical approximation formulas for the interface-Jacobian are derived, which may be used alternatively to numerically calculated gradients based on finite differences. Applying these approximation formulas, numerical problems with ill-conditioning can be circumvented. Moreover, efficiency of the implementation may be increased, since parallel simulations with perturbed coupling variables can be omitted. The derived approximation formulas converge to the exact gradients for small macro-step sizes.
Partners of patients with sleep apnoea/hypopnoea syndrome: effect of CPAP treatment on sleep quality and quality of life
Authors: McArdle N , Kingshott R , Engleman H M , Mackay T W , Douglas N J
Published: July 2021

BACKGROUND

The sleep apnoea/hypopnoea syndrome (SAHS) causes snoring, apnoeas, and restlessness during sleep which partners frequently complain about. A study was undertaken to determine the impact on partners of SAHS and of treatment of the patient with continuous positive airway pressure (CPAP).

METHODS

Forty nine partners and patients with SAHS booked for CPAP treatment completed in house and validated questionnaires (Pittsburgh sleep quality index, Short Form 36 self-reported health status) before the patient started treatment. Twenty three couples in whom the index SAHS patient had no driving problems were recruited to a randomised crossover trial with 1 month limbs of CPAP and placebo capsule. At the end of each limb the partners' sleep was monitored by home polysomnography (PSG) and questionnaires were completed.

RESULTS

Before treatment partners frequently reported moderate to severe disturbance from patient snoring/apnoeas/restlessness and had poor sleep quality and self-reported health status. In the crossover study (22 completed) the partners' objective sleep quality did not differ between CPAP and placebo, but they reported benefit from treatment of the patients with CPAP in subjective sleep quality (p=0.05) and disturbance to sleep (p=0.03). The reported change in partners' sleep quality between pre-study and following CPAP treatment correlated positively with CPAP use (r=0.5, p=0.01).

CONCLUSIONS

Partners of patients with SAHS have poor sleep quality and self-reported health status but only subjective sleep quality benefits from treatment of the patient with CPAP.
Decreased bronchodilating effect of salbutamol in relieving methacholine induced moderate to severe bronchoconstriction during high dose treatment with long acting β2agonists
Authors: van der Woude H J , Winter T H , Aalbers R
Published: July 2021

BACKGROUND

In vitro the long acting β2agonist salmeterol can, in contrast to formoterol, behave as a partial agonist and become a partial antagonist to other β2agonists. To study this in vivo, the bronchodilating effect of salbutamol was measured during methacholine induced moderate to severe bronchoconstriction in patients receiving maintenance treatment with high dose long acting β2agonists.

METHODS

A randomised double blind crossover study was performed in 19 asthmatic patients with mean forced expiratory volume in one second (FEV1) of 88.4% predicted and median concentration of methacholine provoking a fall in FEV1of 20% or more (PC20) of 0.62 mg/ml at entry. One hour after the last dose of 2 weeks of treatment with formoterol (24 μg twice daily by Turbuhaler), salmeterol (100 μg twice daily by Diskhaler), or placebo a methacholine provocation test was performed and continued until there was at least a 30% decrease in FEV1. Salbutamol (50 μg) was administered immediately thereafter, followed by ipratropium bromide (40 μg) after a further 30 minutes. Lung function was monitored for 1 hour after provocation.

RESULTS

There was a significant bronchodilating and bronchoprotective effect after 2 weeks of active treatment. The dose of methacholine needed to provoke a fall in FEV1of ⩾30% was higher after pretreatment with formoterol (2.48 mg) than with salmeterol (1.58 mg) or placebo (0.74 mg). The difference between formoterol and salmeterol was statistically significant: 0.7 doubling dose steps (95% CI 0.1 to 1.2, p=0.016). The immediate bronchodilating effect of subsequently administered salbutamol was significantly impaired after pretreatment with both drugs (p<0.0003 for both). Three minutes after inhaling salbutamol the increase in FEV1relative to the pre-methacholine baseline was 15.8%, 7.3%, and 5.5% for placebo, formoterol and salmeterol, respectively (equivalent to increases of 26%, 14%, and 12%, respectively, from the lowest FEV1after methacholine). At 30 minutes significant differences remained, but 1 hour after completing the methacholine challenge FEV1had returned to baseline values in all three treatment groups.

CONCLUSION

Formoterol has a greater intrinsic activity than salmeterol as a bronchoprotective agent, indicating that salmeterol is a partial agonist compared with formoterol in contracted human airways in vivo. Irrespective of this, prior long term treatment with both long acting β2agonists reduced the bronchodilating effect of an additional single dose of salbutamol equally, indicating that the development of tolerance or high receptor occupancy overshadowed any possible partial antagonistic activity of salmeterol. Patients on regular treatment with long acting β2agonists should be made aware that an additional single dose of a short acting β2agonist may become less effective.
Effect of gas cooking on lung function in adolescents: modifying role of sex and immunoglobulin E
Authors: Corbo G M , Forastiere F , Agabiti N , Dell'Orco V , Pistelli R , Aebischer M L , Valente S , Perucci C A
Published: July 2021

BACKGROUND

A study was undertaken to investigate the effect of gas cooking on the lung function of adolescents while considering serum IgE level as a possible effect modifier.

METHOD

The cross sectional study was performed in 702 subjects aged 11–13 years from primary and secondary schools in Civitavecchia and Viterbo ( Latium region in Central Italy), categorised according to how often they were in the kitchen while the mother cooked (never, sometimes, often). Data were collected by questionnaire and lung function was measured by spirometric tests. Bronchial hyperresponsiveness was evaluated by the methacholine test, atopic status by a skin prick test, and a blood sample was collected to determine serum IgE levels. The results were analysed separately for boys and girls. Multiple regression analysis was performed, taking functional parameters (FEV1, FEV1/FVC, FEF25–75, FEF50, FEF75) as the dependent variables and age, height, parental smoking, and father's education as independent variables.

RESULTS

There was no association between time spent in the kitchen and lung function level in boys, but a reduction in lung function was detected in girls which was statistically significant for FEF75(sometimes –10.3%, often –11.1%). After stratifying boys and girls into four groups on the basis of the IgE serum level (below and above the median value of IgE), the reduction in lung function was significant in girls with a high IgE value whereas no significant deleterious effects were evident in girls with a low IgE value or in boys with either a low or high IgE. The results remained substantially unchanged after excluding girls with a response to methacholine below the concentration of 4 mg/ml, asthmatic patients, and those with positive skin prick tests.

CONCLUSION

Gas cooking has a harmful effect on the lung function of girls with a high serum level of IgE. We do not know whether serum IgE, a marker of allergic susceptibility, is a simple indicator that an inflammatory process is in progress or whether it is involved in the pathogenesis of injury leading to bronchial obstruction.
Induced sputum cell profiles in lung transplant recipients with or without chronic rejection: correlation with lung function
Authors: Beeh K M , Kornmann O , Lill J , Buhl R
Published: July 2021

BACKGROUND

Sputum induction is a non-invasive procedure for measuring inflammatory processes of the lower respiratory tract. The aim of this study was to establish sputum cell counts and differentials in patients after lung transplantation (LTx), with or without chronic transplant rejection.

METHODS

Sputum induction was performed in 41 LTx patients (25 single LTx (sLTx), 16 double LTx (dLTx) and 15 healthy non-smoking volunteers. Sputum was processed according to standard protocols. Total cell count was calculated as mean (SE) cells × 106/ml sputum and cell differential (%) was evaluated after staining. Cellular profiles were correlated with lung function.

RESULTS

Total sputum cell counts were increased in sLTx (9 (1.9) cells × 106/ml, p=0.01) and dLTx patients (7.2 (1.5) × 106/ml, p=0.01) compared with healthy controls (2.6 (0.6) × 106/ml). There was also a marked sputum neutrophilia in both patient groups (59 (6)% and 62 (6)%, respectively, p<0.001vcontrols). Moreover, in both sLTx and dLTx patients with chronic transplant rejection there was an increased number of sputum neutrophils compared with patients with normal graft function (p<0.05 both comparisons), and neutrophils were inversely correlated with lung function (forced expiratory volume in one second (FEV1) % predicted): sLTx,r=–0.61, p=0.001; dLTx,r=–0.75, p=0.001, respectively). Sputum lymphocytes and eosinophils were similar in both groups. No relevant side effects occurred during sputum induction.

CONCLUSIONS

Sputum induction is a safe and non-invasive tool for monitoring lower respiratory tract inflammation in LTx patients. Both sLTx and dLTx patients with chronic rejection had increased sputum neutrophils compared with patients with normal transplant function. These data support findings of other authors highlighting a possible role for neutrophils in the pathogenesis of chronic transplant rejection.
Cardiovascular side effects of inhaled salbutamol in hypoxic asthmatic patients
Authors: Burggraaf J , Westendorp R G J , Veen J C C M in‘t , Schoemaker R C , Sterk P J , Cohen A F , Blauw G J
Published: July 2021

BACKGROUND

Beta-2 adrenoceptor agonists have been associated with sudden death in asthma patients but the cause and underlying mechanism are unclear. Animal experiments indicate that the combination of hypoxia and β2 agonists may result in detrimental cardiovascular effects. A study was undertaken to investigate the effect of hypoxia on the systemic vascular effects of salbutamol in patients with asthma who are hypoxic by assessing forearm blood flow (FBF) as a measure of peripheral vasodilatation.

METHODS

Eight men with mild asthma underwent the following treatments: normoxia + placebo (NP), normoxia + salbutamol (NS), hypoxia + placebo (HP), and hypoxia + salbutamol (HS). The period of mask breathing started at t=0 minutes, lasted for 60 minutes, and at 30 minutes 800 μg salbutamol was inhaled. The experiment was completed 30 minutes after the inhalation (t=60 minutes). For the hypoxia treatment the Spo2 level was 82%. Differences between treatments were sought using factorial ANOVA on percentage change from the pretreatment value.

RESULTS

There were no significant differences in blood pressure and potassium levels between the treatments. After 60 minutes the increase in FBF was 13% (95% CI –12 to 39) more for HP treatment than for NP, 21% (95% CI –5 to 46) more for NS than for NP, and 32% (95% CI 7 to 58) more for HS than for HP (p=0.016). The inhalation of salbutamol during hypoxia resulted in a significant increase in FBF of 45% (95% CI 20 to 71) compared with NP (p=0.001).

CONCLUSION

Patients with asthma who are hypoxic and inhale β2 agonists have serious systemic vascular side effects which may be an additional explanation for the association between asthma treatment and sudden death.
Smoking cessation: integrating recent advances into clinical practice
Authors: Coleman T
Published: July 2021

Smoking remains a prevalent habit with serious consequences for public health. There are now effective treatments for nicotine addiction and, in the UK, specialist services for the treatment of smoking cessation are becoming available in all areas. This paper reviews the role of treatments for nicotine addiction in the management of smoking cessation. Recommendations are made for the judicious use of these therapies and also for the rational use of the new UK smoking cessation services.
Intramural neurofibroma of the trachea treated by multiple stents
Authors: Cranshaw J H , Morgan C , Knowles G , Nicholson A G , Goldstraw P
Published: July 2021

The case history is presented of a patient in whom an intramural tracheal neurofibroma developed, causing severe airway stenosis. The patient was treated with multiple stents over a period of 5 years because of progression of the disease and associated airflow limitation. Clinicians should be aware of this rare complication of neurofibromatosis.
Spectroscopic analysis of the gaseous argon scintillation with a wavelength sensitive particle detector
Authors: Santorelli R. , Garcia E. Sanchez , Abia P. Garcia , González-Díaz D. , Manzano R. Lopez , Morales J. J. Martinez , Pesudo V. , Romero L.
Published: July 2021

We performed a time-resolved spectroscopic study of the VUV/UV scintillation of gaseous argon as a function of pressure and electric field, by means of a wavelength sensitive detector operated with different radioactive sources. Our work conveys new evidence of distinctive features of the argon light which are in contrast with the general assumption that, for particle detection purposes, the scintillation can be considered to be largely monochromatic at 128 nm (second continuum). The wavelength and time-resolved analysis of the photon emission reveal that the dominant component of the argon scintillation during the first tens of ns is in the range [160, 325] nm. This light is consistent with the third continuum emission from highly charged argon ions/molecules. This component of the scintillation is field-independent up to 25 V/cm/bar and shows a very mild dependence with pressure in the range [1, 16] bar. The dynamics of the second continuum emission is dominated by the excimer formation time, whose variation as a function of pressure has been measured. Additionally, the time and pressure-dependent features of electron-ion recombination, in the second continuum band, have been measured. This study opens new paths toward a novel particle identification technique based on the spectral information of the noble-elements scintillation light.
Thermoelectric properties of the (an-)isotropic QGP in magnetic fields
Authors: Zhang He-Xia , Kang Jin-Wen , Zhang Ben-Wei
Published: July 2021

The Seebeck effect and the Nernst effect, which reflect the appearance of electric fields along x-axis and along y-axis ($$E_{x}$$

E
x

and $$E_{y}$$

E
y

), respectively, induced by the thermal gradient along x-axis, are studied in the QGP at an external magnetic field along z-axis. We calculate the associated Seebeck coefficient ($$S_{xx}$$

S

xx

) and Nernst signal (N) using the relativistic Boltzmann equation under the relaxation time approximation. In an isotropic QGP, the influences of magnetic field (B) and quark chemical potential ($$\mu _{q}$$

μ
q

) on these thermoelectric transport coefficients are investigated. In the presence (absence) of weak magnetic field, we find $$S_{xx}$$

S

xx

for a fixed $$\mu _{q}$$

μ
q

is negative (positive) in sign, indicating that the dominant carriers for converting heat gradient to electric field are negatively (positively) charged quarks. The absolute value of $$S_{xx}$$

S

xx

decreases with increasing temperature. Unlike $$S_{xx}$$

S

xx

, the sign of N is independent of charge carrier type, and its thermal behavior displays a peak structure. In the presence of strong magnetic field, due to the Landau quantization of transverse motion of (anti-)quarks perpendicular to magnetic field, only the longitudinal Seebeck coefficient ($$S_{zz}$$

S

zz

) exists. Our results show that the value of $$S_{zz}$$

S

zz

at a fixed $$\mu _{q}$$

μ
q

in the lowest Landau level (LLL) approximation always remains positive. Within the effect of high Landau levels, $$S_{zz}$$

S

zz

exhibits a thermal structure similar to that in the LLL approximation. As the Landau level increases further, $$S_{zz}$$

S

zz

decreases and even its sign changes from positive to negative. The computations of these thermoelectric transport coefficients are also extended to a medium with momentum-anisotropy induced by initial spatial expansion as well as strong magnetic field.
How to discover QCD Instantons at the LHC
Authors: Amoroso Simone , Kar Deepak , Schott Matthias
Published: July 2021

The Standard Model of particle physics predicts the existence of quantum tunnelling processes across topological inequivalent vacua, commonly known as Instantons. In Quantum Chromodynamics, these Instantons play a fundamental role in explaining much of the theory long-distance behaviour. However, they have not yet been observed experimentally. Their direct observation would mark a breakthrough in modern particle physics, shedding light on our fundamental understanding of the non perturbative dynamics in the Standard Model. Recently, new calculations for QCD Instanton processes in proton–proton collisions became public, suggesting sizeable cross sections as well as possible experimental signatures at the LHC. In this work, we explore possible analysis strategies for the LHC experiments to discover small-size QCD Instanton induced processes. Moreover, we derive a first limit on the Instanton production cross section using published data of Minimum Bias processes at $$\sqrt{s}=$$

s

=

13 TeV at the LHC.
A machine learning algorithm for sorting online comments via topic modeling
Authors: Zhu Junzhe , Wickes Elizabeth , Gallagher John R.
Published: July 2021

This article uses a machine learning algorithm to demonstrate a proof-of-concept case for moderating and managing online comments as a form of content moderation, which is an emerging area of interest for technical and professional communication (TPC) researchers. The algorithm sorts comments by topical similarity to a reference comment/article rather than display comments by linear time and popularity. This approach has the practical benefit of enabling TPC researchers to reconceptualize content display systems in dynamic ways.
Towards Enhanced System Efficiency while Mitigating Row Hammer
Authors: Goswami Kaustav , Banerjee Dip Sankar , Das Shirshendu
Published: July 2021

In recent years, DRAM-based main memories have become susceptible to the Row Hammer (RH) problem, which causes bits to flip in a row without accessing them directly. Frequent activation of a row, called an
aggressor row
, causes its adjacent rows’ (
victim
) bits to flip. The state-of-the-art solution is to refresh the victim rows explicitly to prevent bit flipping. There have been several proposals made to detect RH attacks. These include both probabilistic as well as deterministic counter-based methods. The technique of handling RH attacks, however, remains the same. In this work, we propose an efficient technique for handling the RH problem. We show that the mechanism is agnostic of the detection mechanism. Our RH handling technique omits the necessity of refreshing the victim rows. Instead, we use a small non-volatile Spin-Transfer Torque Magnetic Random Access Memory (STTRAM) that ensures no unnecessary refreshes of the victim rows on the DRAM device and thus allowing more time for normal applications in the same DRAM device. Our model relies on the migration of the aggressor rows. This accounts for removing blocking of the DRAM operations due to the refreshing of victim rows incurred in the previous solution. After extensive evaluation, we found that, compared to the conventional RH mitigation techniques, our model minimizes the blocking time of the memory that is imposed due to explicit refreshing by an average of 80.72% in the worst-case scenario and provides energy savings of about 15.82% on average, across different types of RH-based workloads. A lookup table is necessary to pinpoint the location of a particular row, which, when combined with the STTMRAM, limits the storage overhead to 0.39% of a 2 GB DRAM. Our proposed model prevents repeated refreshing of the same victim rows in different refreshing windows on the DRAM device and leads to an efficient RH handling technique.
All-gather Algorithms Resilient to Imbalanced Process Arrival Patterns
Authors: Proficz Jerzy
Published: July 2021

Two novel algorithms for the all-gather operation resilient to imbalanced process arrival patterns (PATs) are presented. The first one, Background Disseminated Ring (BDR), is based on the regular parallel ring algorithm often supplied in MPI implementations and exploits an auxiliary background thread for early data exchange from faster processes to accelerate the performed all-gather operation. The other algorithm, Background Sorted Linear synchronized tree with Broadcast (BSLB), is built upon the already existing PAP-aware gather algorithm, that is, Background Sorted Linear Synchronized tree (BSLS), followed by a regular broadcast distributing gathered data to all participating processes. The background of the imbalanced PAP subject is described, along with the PAP monitoring and evaluation topics. An experimental evaluation of the algorithms based on a proposed mini-benchmark is presented. The mini-benchmark was performed over 2,000 times in a typical HPC cluster architecture with homogeneous compute nodes. The obtained results are analyzed according to different PATs, data sizes, and process numbers, showing that the proposed optimization works well for various configurations, is scalable, and can significantly reduce the all-gather elapsed times, in our case, up to factor 1.9 or 47% in comparison with the best state-of-the-art solution.
SLO-Aware Inference Scheduler for Heterogeneous Processors in Edge Platforms
Authors: Seo Wonik , Cha Sanghoon , Kim Yeonjae , Huh Jaehyuk , Park Jongse
Published: July 2021

With the proliferation of applications with machine learning (ML), the importance of edge platforms has been growing to process streaming sensor, data locally without resorting to remote servers. Such edge platforms are commonly equipped with heterogeneous computing processors such as GPU, DSP, and other accelerators, but their computational and energy budget are severely constrained compared to the data center servers. However, as an edge platform must perform the processing of multiple machine learning models concurrently for multimodal sensor data, its scheduling problem poses a new challenge to map heterogeneous machine learning computation to heterogeneous computing processors. Furthermore, processing of each input must provide a certain level of bounded response latency, making the scheduling decision critical for the edge platform. This article proposes a set of new heterogeneity-aware ML inference scheduling policies for edge platforms. Based on the regularity of computation in common ML tasks, the scheduler uses the pre-profiled behavior of each ML model and routes requests to the most appropriate processors. It also aims to satisfy the service-level objective (SLO) requirement while reducing the energy consumption for each request. For such SLO supports, the challenge of ML computation on GPUs and DSP is its inflexible preemption capability. To avoid the delay caused by a long task, the proposed scheduler decomposes a large ML task to sub-tasks by its layer in the DNN model.
PICO
Authors: Jung Tina , Ritter Fabian , Hack Sebastian
Published: July 2021

Memory safety violations such as buffer overflows are a threat to security to this day. A common solution to ensure memory safety for C is code instrumentation. However, this often causes high execution-time overhead and is therefore rarely used in production.

Static analyses can reduce this overhead by proving some memory accesses in bounds at compile time. In practice, however, static analyses may fail to verify in-bounds accesses due to over-approximation. Therefore, it is important to additionally optimize the checks that reside in the program.

In this article, we present PICO, an approach to eliminate
and
replace in-bounds checks. PICO exactly captures the spatial memory safety of accesses using Presburger formulas to either verify them statically or substitute existing checks with more efficient ones. Thereby, PICO can generate checks of which each covers multiple accesses and place them at infrequently executed locations.

We evaluate our LLVM-based PICO prototype with the well-known SoftBound instrumentation on SPEC benchmarks commonly used in related work. PICO reduces the execution-time overhead introduced by SoftBound by 36% on average (and the code-size overhead by 24%). Our evaluation shows that the impact of substituting checks dominates that of removing provably redundant checks.
Configurable Multi-directional Systolic Array Architecture for Convolutional Neural Networks
Authors: Xu Rui , Ma Sheng , Wang Yaohua , Chen Xinhai , Guo Yang
Published: July 2021

The systolic array architecture is one of the most popular choices for convolutional neural network hardware accelerators. The biggest advantage of the systolic array architecture is its simple and efficient design principle. Without complicated control and dataflow, hardware accelerators with the systolic array can calculate traditional convolution very efficiently. However, this advantage also brings new challenges to the systolic array. When computing special types of convolution, such as the small-scale convolution or depthwise convolution, the
processing element (PE)
utilization rate of the array decreases sharply. The main reason is that the simple architecture design limits the flexibility of the systolic array.

In this article, we design a
configurable multi-directional systolic array (CMSA)
to address these issues. First, we added a data path to the systolic array. It allows users to split the systolic array through configuration to speed up the calculation of small-scale convolution. Second, we redesigned the PE unit so that the array has multiple data transmission modes and dataflow strategies. This allows users to switch the dataflow of the PE array to speed up the calculation of depthwise convolution. In addition, unlike other works, we only make a few changes and modifications to the existing systolic array architecture. It avoids additional hardware overheads and can be easily deployed in application scenarios that require small systolic arrays such as mobile terminals. Based on our evaluation, CMSA can increase the PE utilization rate by up to 1.6 times compared to the typical systolic array when running the last layers of ResNet-18. When running depthwise convolution in MobileNet, CMSA can increase the utilization rate by up to 14.8 times. At the same time, CMSA and the traditional systolic arrays are similar in area and energy consumption.
Gem5-X
Authors: Qureshi Yasir Mahmood , Simon William Andrew , Zapater Marina , Olcoz Katzalin , Atienza David
Published: July 2021

The increasing adoption of smart systems in our daily life has led to the development of new applications with varying performance and energy constraints, and suitable computing architectures need to be developed for these new applications. In this article, we present gem5-X, a system-level simulation framework, based on gem-5, for architectural exploration of heterogeneous many-core systems. To demonstrate the capabilities of gem5-X, real-time video analytics is used as a case-study. It is composed of two kernels, namely, video encoding and image classification using convolutional neural networks (CNNs). First, we explore through gem5-X the benefits of latest 3D high bandwidth memory (HBM2) in different architectural configurations. Then, using a two-step exploration methodology, we develop a new optimized clustered-heterogeneous architecture with HBM2 in gem5-X for video analytics application. In this proposed clustered-heterogeneous architecture, ARMv8 in-order cluster with in-cache computing engine executes the video encoding kernel, giving 20% performance and 54% energy benefits compared to baseline ARM in-order and Out-of-Order systems, respectively. Furthermore, thanks to gem5-X, we conclude that ARM Out-of-Order clusters with HBM2 are the best choice to run visual recognition using CNNs, as they outperform DDR4-based system by up to 30% both in terms of performance and energy savings.