bluuebunny/crossref_metadata_2025 huggingface dataset:
Safety and compatibility of smart device heart rhythm monitoring in patients with cardiovascular implantable electronic devices
Authors: Abudan Anas A. , Isath Ameesh , Ryan James D. , Henrich Mark J. , Dugan Jennifer L. , Attia Zachi I. , Ladewig Dorothy J. , Dillon John J. , Friedman Paul A.
Published: June 2019

Introduction

Emerging medical technology has allowed for monitoring of heart rhythm abnormalities using smartphone compatible devices. The safety and utility of such devices have not been established in patients with cardiac implantable electronic devices (CIEDs). We sought to assess the safety and compatibility of the Food and Drug Administration‐approved AliveCor Kardia device in patients with CIEDs.

Methods and Results

We prospectively recruited patients with CIED for a Kardia recording during their routine device interrogation. A recording was obtained in paced and nonpaced states. Adverse clinical events were noted at the time of recording. Electrograms (EGMs) from the cardiac device were obtained at the time of recording to assess for any electromagnetic interference (EMI) introduced by Kardia. Recordings were analyzed for quality and given a score of 3 (interpretable rhythm, no noise), 2 (interpretable rhythm, significant noise) or 1 (uninterpretable). A total of 251 patients were recruited (59% with a pacemaker and 41% with ICD). There were no adverse clinical events noted at the time of recording and no changes to CIED settings. Review of all EGMs revealed no EMI introduced by Kardia. Recordings were correctly interpreted in 90% of paced recordings (183 had a score of 3, 43 of 2, and 25 of 1) and 94.7% of nonpaced recordings (147 of 3, 15 of 2, and 9 of 1).

Conclusion

The AliveCor Kardia device has an excellent safety profile when used in conjunction with most CIEDs. The quality of recordings was preserved in this population. The device, therefore, can be considered for heart rhythm monitoring in patients with CIEDs.
Catheter ablation of atrial fibrillation in patients with heart failure with reduced ejection fraction: Real world experience from six European centers
Authors: Providência Rui , de Asmundis Carlo , Chun Julian , Chierchia Gianbattista , Defaye Pascal , Anselme Frédéric , Creta Antonio , Lambiase Pier D. , Schmidt Boris , Chen Shaojie , Hunter Ross J. , Combes Stephane , Honarbakhsh Shohreh , Combes Nicolas , Sousa Maria Joao , Jebberi Zeynab , Albenque Jean‐Paul , Boveda Serge
Published: June 2019

Introduction

Catheter ablation of atrial fibrillation (AF) has been recently shown to have an impact on the outcome of patients with heart failure and reduced LV ejection fraction (LVEF). We aimed to assess patients with reduced LVEF referred to catheter ablation of AF, and the efficacy and safety of this procedure compared with healthier patients.

Methods

2083 consecutive procedures of catheter ablation of AF in six centers were divided into two groups on the basis of LVEF (≤ vs >35%) and comparisons were performed regarding procedural safety and efficacy.

Results

Only 51 (2.4%) of patients had low LVEF. Complication rate was comparable: 8.0% vs 6.9% (P = .760). Low LVEF patients are more frequently in persistent AF at the time of the procedure, have a higher degree of left atrial dilation, and higher CHA2DS2VASc score. The rate of atrial arrhythmia relapse post‐blanking period in the first 12 months was higher in the low LVEF group: 58.0% vs 37.6% (P < .001). During a median follow‐up of 14 months (IQR 5‐24), after adjusting for all baseline differences, AF duration, paroxysmal AF, CHA2DS2VASc score, BMI, and indexed LA volume were independent predictors of relapse. LVEF and LVEF ≤ 35% were not identified as predictors of relapse.

Conclusions

Patients with reduced LVEF account for only a minority of patients undergoing catheter ablation of AF. However, ablation appears to be as safe as for the general population, and albeit the efficacy seems lower, this appears to be driven by other comorbidities or features, which are more frequent in this population.
Impact of coronary artery disease and revascularization on recurrence of atrial fibrillation after catheter ablation: Importance of ischemia in managing atrial fibrillation
Authors: Hiraya Daigo , Sato Akira , Hoshi Tomoya , Watabe Hiroaki , Yoshida Kentaro , Komatsu Yuki , Sekiguchi Yukio , Nogami Akihiko , Ieda Masaki , Aonuma Kazutaka
Published: June 2019

Introduction

There are few studies analyzing the association between the presence of coronary artery disease (CAD) and recurrence of atrial fibrillation (AF). This study evaluated the clinical impact of concomitant CAD and coronary revascularization on the recurrence of AF after catheter ablation.

Methods and Results

From April 2008 to December 2015, 700 consecutive patients were treated with pulmonary vein isolation for AF as the initial procedure. Of those, 681 patients who simultaneously underwent coronary angiography were investigated. Patients with at least one coronary stenosis (≥70%) were classified as having obstructive CAD. Of 681 patients, 90 patients had CAD and 42 patients underwent percutaneous coronary intervention (PCI) for lesions with perfusion abnormalities on single‐photon emission tomography. The recurrence of AF was significantly more frequent in patients with CAD (56%) than in those without CAD (39%) (P = .0011). On multivariable analysis, the predictors of AF recurrence were persistent or long‐standing persistent AF [hazard ratio (HR): 1.36; 95% confidence interval (CI): 1.04‐1.77; P = .023], left atrial diameter (HR: 1.04; 95% CI: 1.02‐1.06; P < .0001), and concomitant CAD (HR: 1.45; 95% CI: 1.05‐1.97; P = .024). The recurrence of AF in patients with PCI (38%) was significantly lower than in those without PCI (72%) (P = .0006), and E/E′ significantly improved in patients with PCI (71%) than in those without PCI (42%; P = .001). Performing PCI for concomitant CAD significantly reduced AF recurrence (HR: 0.39; 95% CI: 0.20‐0.72; P = .002).

Conclusion

Patients with CAD had a significantly higher rate of AF recurrence than those without CAD. Coronary revascularization may reduce the recurrence of AF with improvement of left ventricular diastolic function.
Aging three‐spined sticklebacksGasterosteus aculeatus: comparison of estimates from three structures
Authors: Yurtseva Anastasia , Noreikiene Kristina , Lajus Dmitry , Li Zitong , Alapassi Tarja , Ivanova Tatiana , Ivanov Mikhail , Golovin Pavel , Vesala Sami , Merilä Juha
Published: June 2019

In order to assess the accuracy and reliability of age estimates from calcified structures in the three‐spined sticklebackGasterosteus aculeatus, we evaluated intra and inter‐reader repeatability from three structures: otoliths, gill covers and pelvic spines). Average age estimates were also compared between the structures. The overall intra‐reader repeatability of age estimates were highest for otoliths (69%), lowest for gill covers (53%) and intermediate for spine cross‐sections (63%). Although four of the seven readers had the highest intra‐reader repeatability score for spine cross‐sections, the inter‐reader variance in this structure was much higher than in others. Otoliths were the easiest in terms of their pre‐analysis treatment and exchange of materials (as digital images) between readers. In addition, otoliths are more well‐studied compared with the other structures with respect to their development through ontogenesis; hence, age estimates based on otoliths should be the most reliable. Therefore, our recommendation is that whenever possible, analysis of otoliths should be the preferred approach for agingG. aculeatus.
Babassu almonds oil extracted with alternative pressurized green solvents, its triacylglycerol prediction and β‐sitosterol composition
Authors: de Oliveira Naila A. , dos Santos Garcia Alessandra B. , Mazalli Mônica R. , Fukumasu Heidge , de Oliveira Alessandra L.
Published: June 2019

The behavior of two process variables in the oil extraction from babassu almonds (percentage of solvent volume [SV], and the contact time between solvent and the matrix in each batch [St]) was evaluated. In the statistical evaluation, SV was a significant variable in the process that used ethanol as solvent. Conversely, when the solvent was isopropanol, the significant variable was St. The response surface analysis (RSA) indicated that high St, regardless of the solvent amount, results in high yields. The highest yields were 55.34% when isopropanol was the solvent and 53.12% for ethanol. These values represent 92.4 and 88.7% of the oil content in the seeds, respectively. The fatty acid profile, rich in lauric, myristic, oleic, and palmitic acids, was the same regardless of the solvent and operational conditions used. The extract obtained using pressurized isopropanol presented the highest concentration of β‐sitosterol when 3 min was used as St with 66% of SV. When pressurized ethanol was the solvent, the highest concentration of β‐sitosterol was obtained at 2 min of St and 80% of SV. As a function of fatty acid composition, the main triacylglycerols present in babassu oil were COL, LOL, LOM, LOP, and MOP regardless of solvent.

Practical applications

Babassu almond is rich in potassium, phosphorous, magnesium, calcium, and zinc, which are elemental minerals for human health. Being considered oleaginous, it is equally of great importance for cosmetic, pharmaceutical, and food industries. Babassu oil is rich in phytosterols (among them β‐sitosterol) and it is rich in essential fatty acids such as lauric, myristic, oleic, and palmitic acids, which have clinical effects in the treatment of skin ulcers and burns.
Reply to Including Palliative Care in the Assessment of Accountable Care Organizations for End‐of‐Life Care
Authors: Kim Hyosin , Bishop Christine E. , Keating Nancy L. , Hodgkin Dominic , Perloff Jennifer N.
Published: June 2019

This letter comments on the letter by Kwak et al.
Factors influencing the practice of new graduate nurses: A focused ethnography of acute care settings
Authors: Charette Martin , Goudreau Johanne , Bourbonnais Anne
Published: June 2019

Aim

To explore the influence of an acute care setting on competency deployment of new graduate nurses (NGNs) from a competency‐based undergraduate programme.

Background

In the last 15 years, nursing education has shifted to competency‐based education (CBE). Few studies have focused on how NGNs from these reformed programmes use the competencies they have developed. To be paradigmatically coherent with the nature of a competence, studies should also examine how context influences nursing practice and competency deployment.

Design

A focused ethnography of three acute care units from one academic hospital in Canada.

Methods

Purposive and snowball sampling strategies were used to recruit 19 participants: NGNs (n = 4), nurse preceptors (n = 2), clinical nurse specialists (n = 9) and nurse managers (n = 4). Data were collected through individual interviews, focus groups, observation and documentation. Data were analysed according to Roper and Shapira (Ethnography in nursing research. Thousand Oaks, CA: Sage Publications, 2000) ethnographic nursing analysis framework.

Results

Organisational and individual factors were identified as influencing NGNs’ competency deployment. Organisational factors are orientation, stability, workload and the scientific culture of the unit. Personal factors have been linked to groups of professionals: for NGNs, personality and clinical placements during their initial education; for nurses working with NGNs, to be role models, to promote integration and to denounce bullying; and for other health professionals, to recognise nursing expertise.

Conclusion

One way to smooth the transition from academic to clinical settings for NGNs is by offering transition or orientation programmes that will provide them with stability and a reduced workload, allowing them to progressively deploy their competencies.

Relevance to clinical practice

Organisational and individual factors influence how new graduate nurses deploy their competencies. Clinical educators and nurse managers can help new nurses by acting on these factors.

This study conforms to the COREQ Research Reporting Guidelines for qualitative studies.
Two‐month breathing‐based walking improves anxiety, depression, dyspnoea and quality of life in chronic obstructive pulmonary disease: A randomised controlled study
Authors: Lin Feng‐Lien , Yeh Mei‐Ling , Lai Yeur‐Hur , Lin Kuan‐Chia , Yu Chong‐Jen , Chang Jung‐San
Published: June 2019

Aims and objectives

To examine the effects of the two‐month breathing‐based walking intervention and its follow‐up on anxiety, depression, dyspnoea and quality of life in patients with chronic obstructive pulmonary disease.

Background

Mind–body‐related exercises improve bio‐psychological symptoms and quality of life in chronic diseases, but these improvements are not proven for chronic obstructive pulmonary disease.

Design

This was a randomised controlled study and applied the Consolidated Standards of Reporting Trials (CONSORT) statement.

Methods

Outpatients diagnosed with chronic obstructive pulmonary disease were recruited from a medical centre in Taiwan and randomly assigned to two groups. The walking group (n = 42) received breathing, meditation and walking for two months, and the control group (n = 42) did not. Data from the outcomes of anxiety, depression, dyspnoea and quality of life were collected at baseline and in Month 1, Month 2 and Month 3. Clinical trial registration was done (ClinicalTrials.gov.: NCT03388489).

Findings

The results showed significant changes in anxiety, depression, dyspnoea and quality of life in the walking group across three months, compared to those in the control group and at baseline.

Conclusion

This breathing‐based walking intervention is promising to achieve bio‐psychological well‐being for patients with chronic obstructive pulmonary disease.

Relevance to clinical practice

This breathing‐based walking, as a mind–body exercise, could serve as an evidence‐based nursing care that contributes to improving anxiety, depression, dyspnoea and quality of life in stable chronic obstructive pulmonary disease outpatients. The feasibility and acceptability of the breathing‐based walking were met the requirement of the chronic obstructive pulmonary disease outpatients, which could be considered as home‐based exercise.
Do Portfolio Manager Contracts Contract Portfolio Management?
Authors: LEE JUNG HOON , TRZCINKA CHARLES , VENKATESAN SHYAM
Published: June 2019

Most mutual fund managers have performance‐based contracts. Our theory predicts that mutual fund managers with asymmetric contracts and mid‐year performance close to their announced benchmark increase their portfolio risk in the second part of the year. As predicted by our theory, performance deviation from the benchmark decreases risk‐shifting only for managers with performance contracts. Deviation from the benchmark dominates incentives from the flow‐performance relation, suggesting that risk‐shifting is motivated more by management contracts than by a tournament to capture flows.
Firm networks, borders, and regional economic integration
Authors: Brown W. Mark , Dar‐Brodeur Afshan , Tweedle Jesse
Published: June 2019

Borders reduce interprovincial trade relative to intraprovincial trade. Using trade and firm ownership microdata over a 9‐year period (2004–2012), we show firm ownership networks, like trade flows, diminish with distance and borders and that the estimated effect of provincial borders on trade may fall by almost 75% after accounting for firm networks. This suggests the weaker presence of firm networks across borders has a significant, although statistically imprecise, effect on interprovincial trade. These findings reinforce the view that understanding border effects require not only the identification of barriers to trade but also barriers to investment across borders.
Validation of a recommended practice for assessing “characterizing flavor” to meet requirements of the EU Tobacco Product Directive (2014/40/EU)
Authors: Chambers Edgar , Paschke Thilo
Published: June 2019

This publication describes a sensory assessment recommended to fulfill the regulatory requirement for Article 6(2) of the EU Tobacco Products Directive 2014/40/EU, related to whether specific cigarettes have “characterizing flavor,” which is no longer allowed in the European Union (EU) when that “characterizing flavor” results from the use of an additive or combination of additives. It describes (a) background and protocol development, (b) a proposed protocol, (c) studies to evaluate the protocol, (d) the final recommended protocol, and (e) testing results for eight priority additives that the Scientific Committee on Health, Environmental, and Emerging Risks deemed likely to provide nontobacco characterizing flavor in tobacco products. The final protocol screens assessors for sensory acuity, trains them to understand products with/without characterizing flavor, screens out assessors unable to perform the task successfully, determines which cigarette products may have a characterizing flavor, and then what, if any, characterizing flavor is present. The methodology using smell tests as suggested by regulatory staff and other authors was able to identify the positive controls included in the test and a test product containing menthol as having “characterizing flavor.”

Practical Application

“Characterizing flavor” in cigarettes is a sensory phenomenon. Implementation of the recommended protocol for determining “characterizing flavor” in cigarettes, whether premade or “roll your own” is needed to make an objective determination for regulatory needs. This recommended protocol is reliable as determined by various studies and can meet the needs in a reliable manner by various groups.
The influence of high‐dose systemic zoledronate administration on osseointegration of implants with different surface topography
Authors: Hou Michaela , Lee Ryan S. B. , Du Zhibin , Hamlet Stephen M. , Vaquette Cedryck , Ivanovski Sašo
Published: June 2019

Aim

To evaluate the influence of systemic zoledronate administration on the osseointegration of titanium implants with different surface topography in rat maxillae.

Methods

Twenty Sprague‐Dawley rats were divided into two groups—test (bisphosphonate) and control (healthy). Bisphosphonate administration began three weeks prior to implant placement, and the animals received zoledronate (66 μg/kg) three times per week. Forty endosseous implants with a moderately rough (20 implants) or a turned surface (20 implants) were immediately placed bilaterally into extraction sockets of maxillary first molars. Animals were sacrificed after 14 and 28 days of healing, and en bloc specimens were harvested for histological and histomorphometric analysis. Osseointegration was quantified by measuring the percentage of bone‐to‐implant contact.

Results

Bone‐to‐implant contact (BIC) (mean ± SD) values of moderately rough and turned implants at day 14 in test group were 17.62 ± 6.68 and 10.69 ± 1.48, respectively, while in the control group, they were 46.36 ± 5.08 and 33.29 ± 8.89, respectively. At day 28, BIC values of moderately rough and turned implants in the test group were 25.94 ± 7.87 and 7.83 ± 4.30, respectively, while in the control group, they were 72.99 ± 6.60 and 47.62 ± 18.19, respectively. Statistically significant higher BIC values were measured on moderately rough implants compared to turned implants at 28 days, and the control group compared to the test group for both implant surfaces. Histological observations for the control and the test groups demonstrated initial bone formation around moderately rough implants not only on the surface of the parent bone, as was the case with the turned surfaced implants, but also along the implant surface itself.

Conclusions

Systemic zoledronate administration negatively influences osseointegration. Osseointegration was enhanced adjacent to moderately rough compared to turned implants in both the presence and absence of systemic zoledronate administration. Therefore, topographical surface modification may partially offset the negative impact of zoledronate administration.
Hepatitis E virus prevalence in Flemish blood donors
Authors: Vercouter Ann‐Sofie , Van Houtte Freya , Verhoye Lieven , González Fraile Isabel , Blanco Lydia , Compernolle Veerle , Meuleman Philip
Published: June 2019

Transmission of hepatitis E virus (HEV) through transfusion of blood components has already been reported in several European countries. Here, we assessed the HEV prevalence in Flemish blood donors. This study is of importance in order to assess the risk of HEV transmission through blood transfusion. We analysed 38 137 blood donation samples that were collected by the Red Cross Flanders during the period May‐June 2015. All samples were screened for the presence of HEV RNA and a selection for HEV‐specific IgM/IgG. After pooling per 6, 11 pools reacted positive during RNA screening. Reactive pools were deconstructed, and individual samples were retested. After deconstruction, seven samples were confirmed as HEV RNA positive. Serological screening of the confirmed RNA‐positive samples showed that six out of these seven samples were HEV IgM positive, of which three donors were also IgG positive. Serological screening was also performed on the samples that constituted the four initially HEV RNA reactive pools where RNA positivity was not confirmed on the individual level. In three pools, we found indirect evidence of recent HEV exposure. Within 356 randomly selected samples, 31 donations were HEV IgG positive. Here we show that at least 1:5448 of blood donations in Flanders may originate from donors that are actively infected with HEV. Upon transfusion, these donations may pose a major threat towards patients at risk. Finally, a serological analysis showed that the anti‐HEV IgG prevalence in Flemish blood donors is 8.71%.
A Parsimonious Model of Divine Simplicity
Authors: Crisp Oliver D.
Published: June 2019

Many recent treatments of divine simplicity have been highly critical of traditional accounts of the doctrine. Critics have challenged whether the doctrine is coherent and whether it can be squared with a robust theology of the triune God. Yet the theological tradition is largely persuaded that the doctrine of divine simplicity is not only coherent and true, but also that the doctrine of divine simplicity is needed for an account of the Trinity that does not fall into the trap of tritheism. In addition, both Roman Catholic and Protestant traditions include conciliar and confessional support for the doctrine, and allow for more than one way of accounting for the doctrine. This essay offers a constructive account that seeks to avoid some of the most significant concerns raised in the recent theological and philosophical literature. It depends in important respects upon work being done in analytic theology on the use of models in theology, adopted (with suitable amendments) from the philosophy of science. After giving some dogmatic context, three versions of divine simplicity are laid out. Then, a parsimonious version of the doctrine is set forth and considered as a potentially fruitful model, which may have theological utility. The essay ends with some remarks about the way in which this new model of the doctrine may have value in ecumenical theology.
Detecting Financial Collapse and Ballooning Sovereign Risk
Authors: Phillips Peter C. B. , Shi Shuping
Published: June 2019

This paper proposes a new model for capturing discontinuities in the underlying financial environment that can lead to abrupt falls, but not necessarily sustained monotonic falls, in asset prices. This notion of price dynamics is consistent with existing understanding of market crashes, which allows for a mix of market responses that are not universally negative. The model may be interpreted as a martingale composed with a randomized drift process that is designed to capture various asymmetric drivers of market sentiment. In particular, the model is capable of generating realistic patterns of price meltdowns and bond yield inflations that constitute major market reversals while not necessarily being always monotonic in form. The recursive and moving window methods developed in Phillips, Shi and Yu (2015a,b; PSY), which were designed to detect exuberance in financial and economic data, are shown to have detective capacity for such meltdowns and expansions. This characteristic of the PSY tests has been noted in earlier empirical studies by the present authors and other researchers but no analytic reasoning has yet been given to explain why methods intended to capture the expansionary phase of a bubble may also detect abrupt and broadly sustained collapses. The model and asymptotic theory developed in the present paper together explain this property of the PSY procedures. The methods are applied to analyse S&P 500 stock prices and sovereign risk in European Union countries over 2001–16 using government bond yields and credit default swap (CDS) premia. A pseudo real‐time empirical analysis of these data shows the effectiveness of the monitoring strategy in capturing key events and turning points in market risk assessment.
Trichodysplasia spinulosa in a child: Identification of trichodysplasia spinulosa‐associated polyomavirus in skin, serum, and urine
Authors: Chamseddin Bahir H. , Tran Bao Anh Patrick D. , Lee Eunice E. , Pastrana Diana V. , Buck Christopher B. , Wang Richard C. , Kirkorian Anna Yasmine
Published: June 2019

A 6‐year‐old girl with a history of chronic immunosuppression following small bowel and colon transplantation for tufting enteropathy presented with a diffuse, facial‐predominant eruption composed of pink‐to‐skin‐colored papules with central white dystrophic spicules. Histology from a punch biopsy and polymerase chain reaction (PCR) from plucked spicules confirmed a diagnosis of trichodysplasia spinulosa (TS). Additional molecular studies identified several strains of the trichodysplasia spinulosa–associated polyomavirus infecting multiple tissues of the patient, confirming the systemic nature of trichodysplasia spinulosa infections.
Smokeless tobacco: Why does it need special attention?
Authors: Siddiqi Kamran , Mishu Masuma P.
Published: June 2019

See related Commentary
Paul Romer: Ideas, Nonrivalry, and Endogenous Growth
Authors: Jones Charles I.
Published: June 2019

In 2018, Paul Romer and William Nordhaus shared the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel. Romer was recognized “for integrating technological innovations into long‐run macroeconomic analysis”. This article reviews his prize‐winning contributions. Romer, together with others, rejuvenated the field of economic growth. He developed the theory of endogenous technological change, in which the search for new ideas by profit‐maximizing entrepreneurs and researchers is at the heart of economic growth. Underlying this theory, he pinpointed that the nonrivalry of ideas is ultimately responsible for the rise in living standards over time.
A reliable in vitro approach to assess the stability of acetabular implants using digital image correlation
Authors: Morosato F. , Traina F. , Cristofolini L.
Published: June 2019

The main cause of failure of the hip acetabular component is aseptic loosening. Preclinical test methods currently used to assess the stability of hip acetabular implants rely on crude simplifications. Normally, either one component of motion or bone strains are measured. We developed a test method to measure implant 3D translations and rotations and bone strains using digital image correlation. Hemipelvises were aligned and potted to allow consistent testing. A force was applied in the direction of the load peak during level walking. The force was applied in 100‐cycle packages, each load package being 20% larger than the previous one. A digital image correlation system allowed measuring the cup‐bone relative 3D displacements (permanent migrations and inducible micromotions) and the strain distribution in the periacetabular bone. To assess the test repeatability, the protocol was applied to six composite hemipelvises implanted with very stable cups. To assess the suitability of the method to detect mobilisation, six loose implants were tested. The method was repeatable: the interspecimen variability was 16 μm for the bone/cup relative translations, 0.04° for the rotations. The method was capable of tracking extremely loose implants (translations up to 4.5 mm; rotations up to 30°). The strain distribution in the bone was measured, showing the areas of highest strain. We have shown that it is possible to measure the 3D relative translations and rotations of an acetabular cup inside the pelvis and simultaneously to measure the full‐field strain distribution in the bone surface. This will allow better preclinical testing of the stability of acetabular implants.
On the length and depth of finite groups
Authors: Burness Timothy C. , Liebeck Martin W. , Shalev Aner
Published: June 2019

An unrefinable chain of a finite group is a chain of subgroups , where each is a maximal subgroup of . The length (respectively, depth) of is the maximal (respectively, minimal) length of such a chain. We studied the depth of finite simple groups in a previous paper, which included a classification of the simple groups of depth 3. Here, we go much further by determining the finite groups of depth 3 and 4. We also obtain several new results on the lengths of finite groups. For example, we classify the simple groups of length at most 9, which extends earlier work of Janko and Harada from the 1960s, and we use this to describe the structure of arbitrary finite groups of small length. We also present a number‐theoretic result of Heath‐Brown, which implies that there are infinitely many non‐abelian simple groups of length at most 9.

Finally, we study the chain difference of (namely the length minus the depth). We obtain results on groups with chain differences 1 and 2, including a complete classification of the simple groups with chain difference 2, extending earlier work of Brewster et al. We also derive a best possible lower bound on the chain ratio (the length divided by the depth) of simple groups, which yields an explicit linear bound on the length of in terms of the chain difference of , where is the soluble radical of .
Cognitive performance is associated with cerebral oxygenation and peripheral oxygen saturation, but not plasma catecholamines, during graded normobaric hypoxia
Authors: Williams Thomas B. , Corbett Jo , McMorris Terry , Young John S. , Dicks Matt , Ando Soichi , Thelwell Richard C. , Tipton Michael J. , Costello Joseph T.
Published: June 2019

New Findings

What is the central question of this study?

What are the mechanisms responsible for the decline in cognitive performance following exposure to acute normobaric hypoxia?

What are the main findings and their importance?

We found that (1) performance of a complex central executive task (n‐back) was reduced at 0.12; (2) there was a strong correlation between performance of the n‐back task and reductions in and cerebral oxygenation; and (3) plasma adrenaline, noradrenaline, cortisol and copeptin were not correlated with cognitive performance.

It is well established that hypoxia impairs cognitive function; however, the physiological mechanisms responsible for these effects have received relatively little attention. This study examined the effects of graded reductions in fraction of inspired oxygen () on oxygen saturation (), cerebral oxygenation, cardiorespiratory variables, activity of the sympathoadrenal system (adrenaline, noradrenaline) and hypothalamic–pituitary–adrenal axis (cortisol, copeptin), and cognitive performance. Twelve healthy males [mean (SD), age: 22 (4) years, height: 178 (5) cm, mass: 75 (9) kg, FEV1/FVC ratio: 85 (5)%] completed a four‐task battery of cognitive tests to examine inhibition, selective attention (Eriksen flanker), executive function (n‐back) and simple and choice reaction time (Deary–Liewald). Tests were completed before and following 60 min of exposure to 0.2093, 0.17, 0.145 and 0.12. Following 60 min of exposure, response accuracy in the n‐back task was significantly reduced in 0.12 compared to baseline [82 (9) vs. 93 (5)%; P < 0.001] and compared to all other conditions at the same time point [ 0.2093: 92 (3)%; 0.17: 91 (6)%; 0.145: 85 (10)%; 12: 82 (9)%; all P < 0.05]. The performance of the other tasks was maintained. Δaccuracy and Δreaction time of the n‐back task was correlated with both Δ [r(9) = 0.66, P < 0.001 and r(9) = −0.36, P = 0.037, respectively] and Δcerebral oxygenation [r(7) = 0.55, P < 0.001 and r(7) = −0.38, P = 0.045, respectively]. Plasma adrenaline, noradrenaline, cortisol and copeptin were not significantly elevated in any condition or correlated with any of the tests of cognitive performance. These findings suggest that reductions in peripheral oxygen saturation and cerebral oxygenation, and not increased activity of the sympathoadrenal system and hypothalamic–pituitary–adrenal axis, as previously speculated, are responsible for a decrease in cognitive performance during normobaric hypoxia.
Decentralized Passivity-Based Control With a Generalized Energy Storage Function for Robust Biped Locomotion
Authors: Yeatman Mark , Lv Ge , Gregg Robert D.
Published: June 2019

This paper details a decentralized passivity-based control (PBC) to improve the robustness of biped locomotion in the presence of gait-generating external torques and parametric errors in the biped model. Previous work demonstrated a passive output for biped systems based on a generalized energy that, when directly used for feedback control, increases the basin of attraction and convergence rate of the biped to a stable limit cycle. This paper extends the concept with a theoretical framework to address both uncertainty in the biped model and a lack of sensing hardware, by allowing the designer to neglect arbitrary states and parameters in the system. This framework also allows the control to be implemented on wearable devices, such as a lower limb exoskeleton or powered prosthesis, without needing a model of the user's dynamics. Simulations on a six-link biped model demonstrate that the proposed control scheme increases the convergence rate of the biped to a walking gait and improves the robustness to perturbations and to changes in ground slope.
Mean Stress Effect on Fatigue Properties of Type 316 Stainless Steel in Pressurized Water Reactors Primary Water Environment
Authors: Kamaya Masayuki
Published: June 2019

The mean stress effect on the fatigue life of type 316 stainless steel was investigated in simulated pressurized water reactor (PWR) primary water and air at 325 °C. The tests in air environment have revealed that the fatigue life was increased with application of the positive mean stress for the same stress amplitude because the strain range was decreased by hardening of material caused by increased maximum peak stress. On the other hand, it has been shown that the fatigue life obtained in simulated PWR primary water was decreased compared with that obtained in air environment even without the mean stress. In this study, type 316 stainless steel specimens were subjected to the fatigue test with and without application of the positive mean stress in high-temperature air and PWR water environments. First, the mean stress effect was discussed for high-temperature air environment. Then, the change in fatigue life in the PWR water environment was evaluated. It was revealed that the change in the fatigue life due to application of the mean stress in the PWR water environment could be explained in the same way as for the air environment. No additional factor was induced by applying the mean stress in the PWR water environment.
In-Vessel Retention of PHWRs: Experiments at Prototypic Temperatures
Authors: Prasad Sumit V. , Kulkarni P. P. , Yadav D. C. , Verma P. K. , Nayak A. K.
Published: June 2019

In pressurized heavy water reactors (PHWRs), multiple failures of engineered safety features may cause a failure of core cooling eventually leading to core collapse. The failed fuel and fuel channels relocate to the bottom of the calandria vessel (CV) and form a terminal debris bed, which generates decay heat. With time, the moderator evaporates and the terminal debris bed ultimately melts and forms a molten pool of corium. If corium breaches the CV and enters the calandria vault, large amounts of hydrogen and other fission gases may be generated due to molten core concrete interaction, which may pressurize the containment leading to containment failure. In addition, the passive catalytic recombiner devices may be incapable of managing such large amounts of hydrogen. Hence, in-vessel retention of corium is the only option to the avert progression of the accident. The heat removal capability of the CV needs to be demonstrated in order to attain the goal of in-vessel retention, to contain the corium during severe accidents. A lot of numerical analysis of heat removal capability of the CV has been done. However, experimental demonstration of in-vessel retention has been rarely presented in the literature, especially for PHWRs. In this paper, in-vessel retention at prototypic temperatures has been presented. Experiments have been carried out in scaled CVs. Different corium simulants have been used at elevated temperatures and corium coolability has been demonstrated.
Involute Curve Roller Trace Design and Optimization in Multipass Conventional Spinning Based on the Forming Clearance Compensation
Authors: Li Zixuan , Shu Xuedao
Published: June 2019

In industrial production, the roller trace design is still based on the trial-and-error method that is more like an art than science. In this paper, we establish the mathematical model of the involute curve roller trace and adopted the forming clearance compensation in the attaching-mandrel process. The backward pass roller trace is optimized to avoid the roller interference due to blank springback. The spinning simulation model of seven forming passes is set up and verified by the experiments with superalloy GH3030. The wall thickness, the strain distribution, and the tool forces are analyzed. The results show that the forming clearance compensation can greatly shorten the forming time and enhance the production efficiency and saving energy. The metal accumulates at the edge of the blank, and the maximum thinning zone appeared near the edge and is prone to crack. In the straightening pass, the tool forces of both the roller and the mandrel are larger than those in the other passes.
A Multiscale Homogenization Approach for Architectured Knitted Textiles
Authors: Liu D. , Koric S. , Kontsos A.
Published: June 2019

As a type of architectured material, knitted textiles exhibit global mechanical behavior which is affected by their microstructure defined at the scale at which yarns are arranged topologically given the type of textile manufactured. To relate local geometrical, interfacial, material, kinematic and kinetic properties to global mechanical behavior, a first-order, two-scale homogenization scheme was developed and applied in this investigation. In this approach, the equivalent stress at the far field and the consistent material stiffness are explicitly derived from the microstructure. In addition, the macrofield is linked to the microstructural properties by a user subroutine which can compute stresses and stiffness in a looped finite element (FE) code. This multiscale homogenization scheme is computationally efficient and capable of predicting the mechanical behavior at the macroscopic level while accounting directly for the deformation-induced evolution of the underlying microstructure.
First distribution record of the tomato red spider mite Tetranychus evansi (Acari: Tetranychidae) in mainland China
Authors: Tian Lu , Jin Peng-Yu , Sun Chang-Ping , Hong Xiao-Yue
Published: June 2019

The tomato red spider mite, Tetranychus evansi, is an important invasive pest of solanaceous plants worldwide. China is a potentially suitable region for T. evansi but there was no official record of its distribution. In this study, we reported five new records of T. evansi from eggplant, tomato and cucumber in southern and southwest China. The invasion of T. evansi constitutes a new threat to solanaceous crops in mainland China.
General audio tagging with ensembling convolutional neural networks and statistical features
Authors: Xu Kele , Zhu Boqing , Kong Qiuqiang , Mi Haibo , Ding Bo , Wang Dezhi , Wang Huaimin
Published: June 2019

Audio tagging aims to infer descriptive labels from audio clips and it is challenging due to the limited size of data and noisy labels. The solution to the tagging task is described in this paper. The main contributions include the following: an ensemble learning framework is applied to ensemble statistical features and the outputs from the deep classifiers, with the goal to utilize complementary information. Moreover, a sample re-weight strategy is employed to address the noisy label problem within the framework. The approach achieves a mean average precision of 0.958, outperforming the baseline system with a large margin.
Optimizing Companion Cats: Feline Agility, Biopower, and Possibilities of Interspecies Care in Sport
Authors: Bunyak Garrett
Published: June 2019

The increasingly popular sport of feline agility animates human and feline bodies through the construction of rules, obstacles, technologies, and norms. Feline agility, then, involves the management and control of the lives and bodies of both species to meet the expectations of agility competition. In extending Michel Foucault’s concept of biopower to analyze interspecies sport, the current paper suggests two prominent governing organizations of feline agility, International Cat Agility Tournaments (ICAT) and Cat Fanciers Association (CFA), construct human and feline subjects based on a binary construction of a human, capable of acting responsibly, and a feline that lacks a capacity for responsibility. Consequently, humans are constructed as “agility citizens” and are responsibilized to perform the training, enhancement, and optimization of human and feline lives and bodies in the image of normative lifestyle and health dictates pursued principally through acts of consumption. Within narratives of “agility citizenship,” the human subject is positioned to control the feline subject, obscuring and negating feline agency and resistance. Donna Haraway’s concept of “response-ability” is suggested as one avenue to promote interspecies flourishing in sport.
Close-range remote sensing of Saturn’s rings during Cassini’s ring-grazing orbits and Grand Finale
Authors: Tiscareno Matthew S. , Nicholson Philip D. , Cuzzi Jeffrey N. , Spilker Linda J. , Murray Carl D. , Hedman Matthew M. , Colwell Joshua E. , Burns Joseph A. , Brooks Shawn M. , Clark Roger N. , Cooper Nicholas J. , Deau Estelle , Ferrari Cecile , Filacchione Gianrico , Jerousek Richard G. , Le Mouélic Stéphane , Morishima Ryuji , Pilorz Stu , Rodriguez Sébastien , Showalter Mark R. , Badman Sarah V. , Baker Emily J. , Buratti Bonnie J. , Baines Kevin H. , Sotin Christophe
Published: June 2019

Cassini's last look at Saturn's rings

During the final stages of the Cassini mission, the spacecraft flew between the planet and its rings, providing a new view on this spectacular system (see the Perspective by Ida). Setting the scene, Spilker reviews the numerous discoveries made using Cassini during the 13 years it spent orbiting Saturn. Iess
et al.
measured the gravitational pull on Cassini, separating the contributions from the planet and the rings. This allowed them to determine the interior structure of Saturn and the mass of its rings. Buratti
et al.
present observations of five small moons located in and around the rings. The moons each have distinctive shapes and compositions, owing to accretion of ring material. Tiscareno
et al.
observed the rings directly at close range, finding complex features sculpted by the gravitational interactions between moons and ring particles. Together, these results show that Saturn's rings are substantially younger than the planet itself and constrain models of their origin.

Science
, this issue p.
1046
, p.
eaat2965
, p.
eaat2349
, p.
eaau1017
; see also p.
1028
Femtosecond x-ray diffraction reveals a liquid–liquid phase transition in phase-change materials
Authors: Zalden Peter , Quirin Florian , Schumacher Mathias , Siegel Jan , Wei Shuai , Koc Azize , Nicoul Matthieu , Trigo Mariano , Andreasson Pererik , Enquist Henrik , Shu Michael J. , Pardini Tommaso , Chollet Matthieu , Zhu Diling , Lemke Henrik , Ronneberger Ider , Larsson Jörgen , Lindenberg Aaron M. , Fischer Henry E. , Hau-Riege Stefan , Reis David A. , Mazzarello Riccardo , Wuttig Matthias , Sokolowski-Tinten Klaus
Published: June 2019

Structural switch for fast switching

Phase-change materials are important for computer memory. They can quickly switch from glassy to crystalline using a thermal pulse and then lock in that structure for a long time at lower temperature. Zalden
et al.
probed the underlying atomic structure of two phase-change materials during this switching using ultrafast x-rays and simulations (see the Perspective by Rao
et al.
). A liquid-liquid phase transition in both materials allowed fast switching at high temperatures. The lower-temperature glass locks in the structure, allowing for long-term memory storage.

Science
, this issue p.
1062
; see also p.
1032
Response to Comment on “Global pattern of nest predation is disrupted by climate change in shorebirds”
Authors: Kubelka Vojtěch , Šálek Miroslav , Tomkovich Pavel , Végvári Zsolt , Freckleton Robert P. , Székely Tamás
Published: June 2019

Bulla
et al
. dispute our main conclusion that the global pattern of nest predation is disrupted in shorebirds. We disagree with Bulla
et al
.’s conclusions and contest the robustness of their outcomes. We reaffirm our results that provide clear evidence that nest predation has increased significantly in shorebirds, especially in the Arctic.
Science fiction: Fictitious experiments in patents
Authors: Freilich Janet , Ouellette Lisa Larrimore
Published: June 2019

Prophetic examples may unnecessarily distort understanding
Observation of a Majorana zero mode in a topologically protected edge channel
Authors: Jäck Berthold , Xie Yonglong , Li Jian , Jeon Sangjun , Bernevig B. Andrei , Yazdani Ali
Published: June 2019

Majorana on a hinge

One of the early proposals for the physical implementation of Majorana zero modes (MZMs) centered on inducing superconductivity in a topological insulator (TI) by placing it in contact with a superconductor. Jäck
et al.
used scanning tunneling spectroscopy to observe MZMs in a similar heterostructure. In their devices, the TI is a hexagonal bismuth island placed on top of a layer of superconducting niobium. The bismuth island had topological boundary hinge states on every other edge of the hexagon. Placing a cluster of iron atoms on the hinge generated a zero-bias peak characteristic of MZMs at the interface between the cluster and the hinge state.

Science
, this issue p.
1255