bluuebunny/crossref_metadata_2025 huggingface dataset:
Two-Way Coupling Fluid–Structure Interaction Analysis and Tests of Shaft Vibration and Clearance Flow Across Plain Annular Seal
Authors: Miyake Kenjiro , Inoue Tsuyoshi , Watanabe Yusuke
Published: June 2019

Shaft vibration caused by rotor dynamic (RD) fluid force generated by the seal clearance flow has caused several problems. Because such vibration is a coupled phenomenon of clearance flow and shaft vibration, a coupling analysis is essential to solve these problems. In this study, a two-way coupling fluid–structure interaction (FSI) analysis of the seal clearance flow and shaft vibration of a rotor system was conducted and verified through experiments. The rotor system used was a vertical, flexible rotor system with a plain annular seal. In the numerical analysis of the seal clearance flow, the continuity equation and momentum equations, which were averaged across the film thickness, were numerically solved. To suppress the numerical instability, which is unique to the coupling analysis, and improve its numerical stability, a method of successively correcting pressure and shaft acceleration values was adopted so that the continuity equation and rotor equations of motion could be satisfied at every time step. By performing the coupling simulation, the frequency response characteristics of whirling amplitude and leakage flow were investigated. In regard to the stability of the system, the rotational speeds at which self-excited vibration occurs (onset speed of instability: OSI) in its increasing condition and ceases (onset speed of dropdown: OSD) in its decreasing condition were investigated. The coupling analysis results reasonably agree with the experimental results, which demonstrate the validity of the analysis method. In addition, the influence of static eccentricity and whirling amplitude on stability (OSI and OSD) was clarified, which are useful in the design stage of turbomachinery.
Comparison of Ultra-High Rail Pressures and Postinjections for Soot Reduction With Massive Exhaust Gas Recirculation
Authors: Ogren Ryan M. , Kong Song-Charng
Published: June 2019

In this study, the application of ultra-high fuel injection pressure (up to 300 MPa) is compared with that of a post injection strategy for the reduction of soot at medium load conditions with exhaust gas recirculation (EGR) rates greater than 40%. Emissions were predominantly studied at the engine's maximum brake torque speed of 1600 rpm. A 4.5-L, four-cylinder diesel engine with series turbochargers and a high-pressure EGR loop was used for all tests. Results indicate that, ultra-high injection pressures may not have large effects on hydrocarbons (HC) or CO emissions. Small soot reductions were achieved at the expense of increased NOx emissions. Post injections resulted in larger soot reductions for a small increase in NOx while allowing lower fuel pressures to be utilized. The increase in NOx emissions with a post injection was observed to be comparatively less at increased engine speeds. For operation at high EGR, post injections were observed to be more effective at reducing soot than ultra-high injection pressures. Both injection pressure and post injections were observed to have small to negligible effects on engine fuel consumption, leaving EGR and injection timing as the primary efficiency drivers at the conditions studied.
An Experimental Investigation of Properties of Nanofluid and Its Performance on Thermosyphon Cooled by Natural Convection
Authors: Das Sidhartha , Giri Asis , Samanta S. , Kanagaraj S.
Published: June 2019

An attempt is made here to characterize thermal conductivity of water-based Al2O3 nanofluid and then use the same in a circular finned thermosyphon (TPCT) to measure its thermal performance. The concentration of Al2O3 nanofluid is varied within 0.05–0.25% by volume. The thermal conductivity of nanofluid is increased with concentration of Al2O3 nanoparticles as well as with temperature. A maximum of 26.7% enhancement of thermal conductivity is observed at 45 °C for 0.25% concentration by volume of nanofluid in comparison to that of de-ionized (DI) water. Variations of surface tension and contact angle of Al2O3 nanofluid are also compared with DI water. One of the smallest TPCT with different heat inputs (4 W, 8 W, and 12 W) and different inclinations (30 deg, 45 deg, 60 deg, and 90 deg) is tested for different concentration of Al2O3 nanofluid, which will find application in smaller electronic units. It is found that use of nanofluid decreases the wall temperature distribution of TPCT. Thermal resistance of TPCT decreases whenever TPCT is filled with nanofluid and a maximum of 36.4% reduction in thermal resistance is noted for 0.25% volume of nanoparticles at 4 W with an inclination of 60 deg. It is also found that performance of TPCT is higher at 60 deg inclination compared to other inclinations, especially for lower heat input.
Influence of Peak Menstrual Cycle Hormonal Changes on Restoration of Fluid Balance After Induced Dehydration
Authors: Rodriguez-Giustiniani Paola , Galloway Stuart D.R.
Published: June 2019

The present study examined the impact of hormonal differences between late follicular (LF) and midluteal (ML) phases on restoration of fluid balance following dehydration. Ten eumenorrheic female participants were dehydrated by 2% of their body mass through overnight fluid restriction followed by exercise-heat stress. Trials were undertaken during the LF (between Days 10 and 13 of the menstrual cycle) and ML phases (between Days 18 and 23 of the menstrual cycle) with one phase repeated to assess reliability of observations. Following dehydration, participants ingested a volume equivalent to 100% of mass loss of a commercially available sports drink in four equal volumes over 30 min. Mean serum values for steroid hormones during the ML (estradiol [E2]: 92 ± 11 pg/ml, progesterone: 19 ± 4 ng/ml) and LF (estradiol [E2]: 232 ± 64 pg/ml, progesterone: 3 ± 2 ng/ml) were significantly different between phases. Urine tests confirmed no luteinizing hormone surge evident during LF trials. There was no effect of menstrual cycle phase on cumulative urine volume during the 3-hr rehydration period (ML: 630 [197–935] ml, LF: 649 [180–845] ml) with percentage of fluid retained being 47% (33–85)% on ML and 46% (37–89)% on LF (p = .29). There was no association between the progesterone:estradiol ratio and fluid retained in either phase. Net fluid balance, urine osmolality, and thirst intensity were not different between phases. No differences in sodium (ML: −61 [−36 to −131] mmol, LF: −73 [−5 to −118] mmol; p = .45) or potassium (ML: −36 [−11 to −80] mmol, LF: −30 [−19 to −89] mmol; p = .96) balance were observed. Fluid replacement after dehydration does not appear to be affected by normal hormonal fluctuations during the menstrual cycle in eumenorrheic young women.
Basal Serum Cortisol and Testosterone/Cortisol Ratio Are Related to Rate of Na+ Lost During Exercise in Elite Soccer Players
Authors: Castro-Sepulveda Mauricio , Cancino Jorge , Fernández-Verdejo Rodrigo , Pérez-Luco Cristian , Jannas-Vela Sebastian , Ramirez-Campillo Rodrigo , Del Coso Juan , Zbinden-Foncea Hermann
Published: June 2019

During exercise, the human body maintains optimal body temperature through thermoregulatory sweating, which implies the loss of water, sodium (Na+), and other electrolytes. Sweat rate and sweat Na+ concentration show high interindividual variability, even in individuals exercising under similar conditions. Testosterone and cortisol may regulate sweat Na+ loss by modifying the expression/activity of the cystic fibrosis transmembrane conductance regulator. This has not been tested. As a first approximation, the authors aimed to determine whether basal serum concentrations of testosterone or cortisol, or the testosterone/cortisol ratio relate to sweat Na+ loss during exercise. A total of 22 male elite soccer players participated in the study. Testosterone and cortisol were measured in blood samples before exercise (basal). Sweat samples were collected during a training session, and sweat Na+ concentration was determined. The basal serum concentrations of testosterone and cortisol and their ratio were (mean [SD]) 13.6 (3.3) pg/ml, 228.9 (41.4) ng/ml, and 0.06 (0.02), respectively. During exercise, the rate of Na+ loss was related to cortisol (r = .43; p < .05) and to the testosterone/cortisol ratio (r = −.46; p < .01), independently of the sweating rate. The results suggest that cortisol and the testosterone/cortisol ratio may influence Na+ loss during exercise. It is unknown whether this regulation depends on the cystic fibrosis transmembrane conductance regulator.
Dinosaur-age landscapes lurk in Southern Hemisphere
Authors: Voosen Paul
Published: June 2019

Ancient plateaus, armored against erosion by impermeable minerals, hold clues to Earth's deep history.
Taking ‘baby steps’ to human organs in livestock
Authors: Servick Kelly
Published: June 2019

Chimera experiments tackle basic interaction between foreign and host cells.
Tests measure progress of quantum computers
Authors: Cho Adrian
Published: June 2019

Designers propose benchmarks and metrics for not-yet-useful machines.
Dynamic genetic regulation of gene expression during cellular differentiation
Authors: Strober B. J. , Elorbany R. , Rhodes K. , Krishnan N. , Tayeb K. , Battle A. , Gilad Y.
Published: June 2019

Variants affect gene expression over time

Genetic variation drives the spectrum of human phenotypes but in some cases has been linked to pathological conditions. Strober
et al.
set out to explore how genetic diversity regulates gene expression in cell differentiation over time. They examined expression quantitative trait loci (eQTLS)—genetic variants correlated with gene expression—in induced pluripotent stem cell lines from 19 Yoruban individuals at 16 time points during differentiation into cardiomyocytes. They identified hundreds of developmental stage–specific eQTLs. Thus, the impact of genetic variations depends on the developmental context or tissue under observation.

Science
, this issue p.
1287
A single fast radio burst localized to a massive galaxy at cosmological distance
Authors: Bannister K. W. , Deller A. T. , Phillips C. , Macquart J.-P. , Prochaska J. X. , Tejos N. , Ryder S. D. , Sadler E. M. , Shannon R. M. , Simha S. , Day C. K. , McQuinn M. , North-Hickey F. O. , Bhandari S. , Arcus W. R. , Bennert V. N. , Burchett J. , Bouwhuis M. , Dodson R. , Ekers R. D. , Farah W. , Flynn C. , James C. W. , Kerr M. , Lenc E. , Mahony E. K. , O’Meara J. , Osłowski S. , Qiu H. , Treu T. , U V. , Bateman T. J. , Bock D. C.-J. , Bolton R. J. , Brown A. , Bunton J. D. , Chippendale A. P. , Cooray F. R. , Cornwell T. , Gupta N. , Hayman D. B. , Kesteven M. , Koribalski B. S. , MacLeod A. , McClure-Griffiths N. M. , Neuhold S. , Norris R. P. , Pilawa M. A. , Qiao R.-Y. , Reynolds J. , Roxby D. N. , Shimwell T. W. , Voronkov M. A. , Wilson C. D.
Published: June 2019

Pinpointing a single fast radio burst

Fast radio bursts (FRBs) are flashes of radio emission from distant astronomical sources. Two FRBs are known to have repeated, but most last just a few milliseconds and are never seen again. Most telescopes that are sensitive to single FRBs have poor angular resolutions, so the FRB host galaxies remain unknown. Bannister
et al.
used a dedicated observing mode on a radio interferometer to detect and localize the nonrepeating FRB 180924, then followed up with optical telescope observations (see the Perspective by Petroff). They found that the FRB came from a medium-sized galaxy at a cosmological distance. Localizing FRBs will help determine their causes and allow them to be used as cosmological probes.

Science
, this issue p.
565
; see also p.
546
Structure of the Cdc48 segregase in the act of unfolding an authentic substrate
Authors: Cooney Ian , Han Han , Stewart Michael G. , Carson Richard H. , Hansen Daniel T. , Iwasa Janet H. , Price John C. , Hill Christopher P. , Shen Peter S.
Published: June 2019

Protein unfolding, one substrate at a time

Ubiquitin marks proteins for degradation by the proteasome. However, many substrates cannot be directly degraded because they are well folded or are located in cell membranes or in multimeric complexes. These proteins are first unfolded by the Cdc48 adenosine triphosphatase (ATPase), which forms a hexameric assembly that pulls polypeptides through its central pore. Twomey
et al.
determined structures of Cdc48 at an initiation stage of substrate processing. Surprisingly, a ubiquitin molecule in the substrate-linked polyubiquitin chain could be unfolded simply by binding to the Cdc48 complex. A segment of the unfolded ubiquitin inserts into the ATPase ring and initiates substrate unfolding. This explains why Cdc48 can deal with a broad range of substrates—even ones that are folded. Cooney
et al.
report the cryo–electron microscopy structure of Cdc48 in complex with an authentic substrate. In contrast to previously reported Cdc48 structures, an asymmetric spiraling assembly wraps around the extended substrate polypeptide. Thus, Cdc48 uses a hand-over-hand mechanism of translocation, which supports a common mechanism for protein substrate unfolding for AAA+ ATPases.

Science
, this issue p.
eaax1033
, p.
502
Mutation hotspots may not be drug targets
Authors: Carter Hannah
Published: June 2019

Recurrent mutations in tumors can be artifacts of nonrandom mutagenic processes
Activity of Imipenem-Relebactam and Comparator Agents against Genetically Characterized Isolates of Carbapenem-Resistant Enterobacteriaceae
Authors: Canver Matthew C. , Satlin Michael J. , Westblade Lars F. , Kreiswirth Barry N. , Chen Liang , Robertson Amy , Fauntleroy Kathy , La Spina Marisa , Callan Katrina , Jenkins Stephen G.
Published: June 2019

Carbapenem-resistant
Enterobacteriaceae
(CRE) strains are an urgent public health threat. We evaluated the
in vitro
activities of 19 antimicrobial agents, including imipenem-relebactam, against (i) 106 CRE bloodstream isolates that primarily expressed
Klebsiella pneumoniae
carbapenemase (KPC) and (ii) 20 OXA-48-like-expressing CRE isolates. Ninety-five percent of CRE bloodstream isolates were susceptible to imipenem-relebactam.
Secretory Expression Fine-Tuning and Directed Evolution of Diacetylchitobiose Deacetylase by Bacillus subtilis
Authors: Jiang Zhu , Niu Tengfei , Lv Xueqin , Liu Yanfeng , Li Jianghua , Lu Wei , Du Guocheng , Chen Jian , Liu Long
Published: June 2019

We successfully achieved efficient secretory production and improved the catalytic efficiency of diacetylchitobiose deacetylase in
Bacillus subtilis
, and this provides a good foundation for the application of diacetylchitobiose deacetylase in the production of chitosan oligosaccharides and monosaccharides.
Facial swelling and dysphonia during labour: a case of Hamman’s syndrome
Authors: James Rhian Elin , Bhanu Cini , Hapuarachi Sharleen , Leyva Caraballo Erick
Published: June 2019

We present the case of a previously fit and well 30-year-old primiparous woman who developed Hamman’s syndrome during the second stage of labour. This is an unusual and peculiar condition, characterised by spontaneous pneumomediastinum and subcutaneous emphysema. The rarity of the condition means it can easily be misdiagnosed. Its exact aetiology is unknown, but it is believed that extreme Valsalva manoeuvre during prolonged or difficult labours may contribute to its development. Chest X-ray is the first investigation of choice in this presentation, followed by CT scanning. Fortunately, it is usually a benign condition that can be managed conservatively and resolved quickly, with no long-term effects and low risk of recurrence in future pregnancies. We are pleased to say that this case does not differ in this respect. It is, however, important to rule other more serious pathologies that present in a similar way, for example, Boerhaave syndrome, pneumothorax or pulmonary embolism.
Asymptomatic gossypiboma with complete intramural migration and ileoileal fistula
Authors: Singhal Pranav Mohan , Vats Manu , Neogi Sushanto , Agarwal Mehul
Published: June 2019

Retained gossypiboma is a rare and under-reported complication of surgery, which can present in a variety of ways. Thus, a very high index of suspicion is required by the clinician to clinch the diagnosis in a postoperative patient. A 45-year-old woman, who was otherwise asymptomatic, presented to the General Surgery outpatient department (OPD) with a contrast-enhanced CT suggestive of a retained intra-abdominal foreign body from previous surgery. An exploratory laparotomy was planned on elective basis. Intraoperatively, dense inter-bowel adhesions were found in the upper abdomen. After a meticulous adhesiolysis, an ileoileal fistula and an intraluminal surgical sponge were discovered. Resection and anastomosis of the involved ileal segment was done. An asymptomatic patient with a migrated intramural gossypiboma with an ileoileal fistula is an extremely rare occurrence. In these circumstances, it becomes almost impossible for the surgeon to clinch the diagnosis of a gossypiboma in an otherwise asymptomatic patient, without the aid of radiological investigations.
Neonatal parechovirus infection mimicking a surgical abdomen
Authors: Kirkley Megan J , Robinson Christine , Dominguez Samuel R , Messacar Kevin
Published: June 2019

Human parechovirus-3 (PeVA3) infection is a common cause of febrile illness in young infants and the spectrum of clinical presentation is broad. We describe a term infant who presented with marked abdominal distension and anorexia, concerning for an acute surgical abdomen. Evaluation revealed that the infant had PeVA3 infection. This case highlights the importance of recognising severe abdominal distension and discomfort as a clinical presentation associated with PeV and the potential utility of rapid testing for PeV.
Small bowel volvulus versus adhesive small bowel obstruction: a diagnostic dilemma in a 19-year-old woman
Authors: Choy Kay Tai , Brunott Nathan
Published: June 2019

Small bowel volvulus (SBV) is often challenging to diagnose. Research suggests that the clinical presentation of this disease is often very similar to other more common causes of small bowel obstruction (SBO) such as intraabdominal adhesions and no single preoperative diagnostic study is sensitive or specific enough to identify this rare cause of mechanical SBO. This report describes a case of a 19-year-old woman who presented with irretractable vomiting and abdominal pain secondary to SBV. This case is unusual as her history of recurrent adhesive SBO presented a diagnostic dilemma that required a higher degree of clinical suspicion to tease these differential diagnoses apart. She underwent laparoscopy which facilitated successful detorsion and resection of the floppy tongue of jejunum. This report aims to increase the awareness among surgeons.
Atrial septal aneurysm with rare comorbid pulmonary arteriovenous malformation as aetiology for cryptogenic stroke
Authors: Bell Kendall , Abu-Heija Ahmad , Smith Antonio , Nnodim Ijeoma
Published: June 2019

Atrial septal aneurysms have two mechanisms for cardioembolic events. One is the aneurysm itself can act as a nidus for thrombus formation in the left atrium. The aneurysm creates an area of low turbulence leading to haemostasis allowing fibrin-platelet adhesions to form. If the clot is on the left atrial wall, it may be dislodged by oscillations of the septum and travel into the systemic circulation. The second mechanism is via, an often comorbid, interatrial shunt such as a Patent Foramen Ovale or Atrial Septal Defect. We report a unique case where the associated right to left shunt leading to the cryptogenic stroke is a pulmonary arteriovenous malformation.
Sex differences in congenital heart disease in Down syndrome: study data from medical records and questionnaires in a region of Japan
Authors: Takano Takako , Akagi Michio , Takaki Haruyoshi , Inuzuka Ryo , Nogimori Yoshitsugu , Ono Hiroshi , Kaneko Masahide , Hagiwara Norifumi
Published: June 2019

Reports indicate lower Down syndrome (DS) survival among females than among males in Australia, contrasting with female longevity in the general population. Using data on 1310 people with DS (626 females and 684 males) in Japan from five hospitals’ medical records and questionnaires completed by parents of people with DS, we investigated sex differences in congenital heart disease (CHD), which may be related to mortality. The CHD rate was significantly higher for females (354, 57%) than for males (338, 49%; p=0.010). Significantly more females (199, 32%) than males (175, 26%) underwent surgery for CHD (p=0.018).
Prognostic patterns and predictors in epilepsy: a multicentre study (PRO-LONG)
Authors: Beghi Ettore , Beretta Simone , Carone Davide , Zanchi Clara , Bianchi Elisa , Pirovano Marta , Trentini Claudia , Padovano Giada , Colombo Matteo , Cereda Diletta , Scanziani Sofia , Giussani Giorgia , Gasparini Sara , Bogliun Graziella , Ferrarese Carlo
Published: June 2019

Objectives

To describe the long-term prognosis of epilepsy and prognostic patterns in a large cohort of newly diagnosed patients and identify prognostic factors.

Methods

Study participants were 13 Italian epilepsy centres with accessible records dating back to 2005 or earlier, complete data on seizure outcome and treatments, precise epilepsy diagnosis, and follow-up of at least 10 years. Records were examined by trained neurology residents for demographics, seizure characteristics, neurological signs, psychiatric comorbidity, first electroencephalogram (EEG) and MRI/CT, epilepsy type and aetiology, antiepileptic drugs (AEDs), and 1-year, 2-year, 5-year and 10-year seizure remissions. Five predefined prognostic patterns were identified: early remission, late remission, relapsing-remitting course, worsening course and no remission. Prognostic factors were assessed using multinomial logistic regression models.

Results

1006 children and adults were followed for 17 892 person-years (median 16 years; range 10–57). During follow-up, 923 patients (91.7%) experienced 1-year remission. 2-year, 5-year and 10-year remissions were present in 89.5%, 77.1% and 44.4% of cases. 5-year remission was associated with one to two seizures at diagnosis, generalised epilepsy, no psychiatric comorbidity, and treatment with one or two AEDs during follow-up. 10-year remission was associated with one or two AEDs. The most common prognostic pattern was relapsing-remitting (52.2%), followed by early remission (24.5%). 8.3% of cases experienced no remission. Predictors of a relapsing-remitting course were <6 seizures at diagnosis, (presumed) genetic aetiology and no psychiatric comorbidity.

Conclusions

Few seizures at diagnosis, generalised epilepsy and no psychiatric comorbidity predict early or late seizure freedom in epilepsy. Achieving remission at any time after the diagnosis does not exclude further relapses.
Methane emissions, feed intake, and total tract digestibility in lambs fed diets differing in fat content and fibre digestibility
Authors: McGeough E.J. , Passetti L.C.G. , Chung Y.H. , Beauchemin K.A. , McGinn S.M. , Harstad O.M. , Crow G. , McAllister T.A.
Published: June 2019

This study determined enteric methane (CH4) emissions, intake, and apparent total tract digestibility of diets varying in fibre digestibility and fat content. A Latin square design with two levels of fat [2.0% and 6.0% dry matter (DM); low and high] and two levels of fibre digestibility [low fibre digestibility (LFbD) or high fibre digestibility (HFbD)] was used. Higher dry matter intake (DMI) was observed (P < 0.01) for LFbD versus HFbD diets (2.56 vs. 2.14 kg d−1, respectively), with no effect of fat. Fibre, DM, and organic matter digestibility were higher (P < 0.01) for HFbD than LFbD diets. Increasing fat did not affect intake or digestibility of DM or dietary constituents but there was a fibre digestibility × fat content interaction (P < 0.01) for fat digestibility. There was also a fat content × fibre digestibility interaction (P < 0.05) for CH4 (g kg−1 DMI, organic matter intake, neutral detergent fibre intake, and percent gross energy intake), with emissions being higher when fat was added to the HFbD than the LFbD diet. The CH4 emissions per kilogram of neutral detergent fibre (NDF) digested were higher (P < 0.01) for the HFbD than the LFbD diet. Methane emissions were increased by the HFbD diet, but inclusion of fat had a differential impact on CH4 emissions as a proportion of DMI or NDF intake in diets differing in fibre digestibility.
Evidence for spring stopover refuelling in migrating silver-haired bats (Lasionycteris noctivagans)
Authors: Jonasson Kristin A. , Guglielmo Christopher G.
Published: June 2019

Migrating animals must acquire sufficient fuel to sustain migratory movement, but how time is allocated to achieve this can vary greatly. The fuel strategies used by migrating bats are not well understood and have not been investigated during the spring when insectivorous bats face low food abundance. Migrating silver-haired bats (Lasionycteris noctivagans (Le Conte, 1831)) were captured at a stopover site in Long Point, Ontario, Canada, in April and May of 2012–2014. We followed the movements of 40 bats outfitted with radio transmitters using an automated telemetry array and examined the effects of ambient temperature, fat stores, and sex on stopover duration. As seen previously in autumn, most bats departed the evening following capture, but one-third of bats used multiday stopovers. Extended stopover was associated with lower ambient temperature. There was no effect of sex or fat at capture on stopover departure probability. Bats captured closer to dawn had greater fat mass and lean mass than those captured early in the night, a trend indicative of fuel deposition at this site. This is the first study to provide evidence that bats use stopover habitat for refuelling.
A Machine Learning Approach to Characterize the Modulation of the Hippocampal Rhythms Via Optogenetic Stimulation of the Medial Septum
Authors: Park Sang-Eon , Laxpati Nealen G. , Gutekunst Claire-Anne , Connolly Mark J. , Tung Jack , Berglund Ken , Mahmoudi Babak , Gross Robert E.
Published: June 2019

The medial septum (MS) is a potential target for modulating hippocampal activity. However, given the multiple cell types involved, the changes in hippocampal neural activity induced by MS stimulation have not yet been fully characterized. We combined MS optogenetic stimulation with local field potential (LFP) recordings from the hippocampus and leveraged machine learning techniques to explore how activating or inhibiting multiple MS neuronal subpopulations using different optical stimulation parameters affects hippocampal LFP biomarkers. First, of the seven different optogenetic viral vectors used for modulating different neuronal subpopulations, only two induced a substantial change in hippocampal LFP. Second, we found hippocampal low-gamma band to be most effectively modulated by the stimulation. Third, the hippocampal biomarkers were sensitive to the optogenetic virus type and the stimulation frequency, establishing those parameters as the critical ones for the regulation of hippocampal biomarker activity. Last, we built a Gaussian process regression model to describe the relationship between stimulation parameters and activity of the biomarker as well as to identify the optimal parameters for biomarker modulation. This new machine learning approach can further our understanding of the effects of neural stimulation and guide the selection of optimal parameters for neural control.
Quantum image encryption based on phase-shift transform and quantum Haar wavelet packet transform
Authors: Li Hai-Sheng , Li ChunYu , Chen Xiao , Xia HaiYing
Published: June 2019

An algorithm of quantum image encryption based on a normal arbitrary superposition state (NASS) is proposed by using quantum geometric transform, phase-shift transform, and quantum Haar wavelet packet transform (QHWPT) in this paper. Firstly, to scramble an image, we design an implementation circuit of quantum image pixel exchanges along diagonal lines. Next, [Formula: see text] keys randomly distributed between 0 and [Formula: see text] are encoded in the encryption algorithm by using phase-shift transform. The huge key space makes it difficult to attack encrypted images. Then, we store image information in low frequency using QHWPT to improve encryption effect. After that, the encryption algorithms of gray image and color image are simulated by using MATLAB, respectively. Meanwhile, evaluation indexes such as histogram, complexity and correlation of adjacent pixels are analyzed. Simulation experiments show that the proposed algorithm is valid.
First-principles investigation of the vacancy-related properties of Ta2AlC
Authors: Liu Jitao , Meng Zhaocang , Liu Jiajia , Zhu Xiaolu , Wang Canglong , Yang Lei
Published: June 2019

The formation energies and formation volumes of the Ta, Al, and C vacancies in Ta2AlC have been calculated by using first-principles method. The results have shown that the vacancy formation is energetically most favorable for the C atom with formation energy of 1.72 eV. The formation energies of Ta and Al vacancies are 3.44 eV and 3.52 eV, respectively. The electronics properties show that the Ta vacancy has a clear effect on the conductivity of the Ta2AlC. This result indicates that Ta2AlC is a good candidate material for high-temperature and nuclear applications.
Content-based image retrieval based on supervised learning and statistical-based moments
Authors: Singh Vibhav Prakash , Srivastava Rajeev , Pathak Yadunath , Tiwari Shailendra , Kaur Kuldeep
Published: June 2019

Content-based image retrieval (CBIR) system generally retrieves images based on the matching of the query image from all the images of the database. This exhaustive matching and searching slow down the image retrieval process. In this paper, a fast and effective CBIR system is proposed which uses supervised learning-based image management and retrieval techniques. It utilizes machine learning approaches as a prior step for speeding up image retrieval in the large database. For the implementation of this, first, we extract statistical moments and the orthogonal-combination of local binary patterns (OC-LBP)-based computationally light weighted color and texture features. Further, using some ground truth annotation of images, we have trained the multi-class support vector machine (SVM) classifier. This classifier works as a manager and categorizes the remaining images into different libraries. However, at the query time, the same features are extracted and fed to the SVM classifier. SVM detects the class of query and searching is narrowed down to the corresponding library. This supervised model with weighted Euclidean Distance (ED) filters out maximum irrelevant images and speeds up the searching time. This work is evaluated and compared with the conventional model of the CBIR system on two benchmark databases, and it is found that the proposed work is significantly encouraging in terms of retrieval accuracy and response time for the same set of used features.
Ratchet effects of a Brownian particle system with non-Gaussian noise driven by a biharmonic force
Authors: Xu Jinzheng , Luo Xiaoqin
Published: June 2019

The ratchet effect of an overdamped Brownian particle subjected to a spatially symmetric potential driven by a biharmonic temporal force is investigated when a non-Gaussian noise is considered. It is found that the noise intensity and the departure from the Gaussian noise will suppress the ratchet transport effect, while the noise color will strengthen the ratchet transport effect. In the same time, the phase difference mainly changes the direction of the transport. It is also shown that the abundant transport phenomenon is due to the breaking of symmetry for the biharmonic force.
Epileptic Seizure Detection System Based on Multi-Domain Feature and Spike Feature of EEG
Authors: Wu Duanpo , Wang Zimeng , Huang Hong , Wang Guangsheng , Liu Junbiao , Cai Chenyi , Xu Weifeng
Published: June 2019

Epilepsy is caused by sudden abnormal discharges of neurons in the brain. This paper constructs an automatic seizure detection system, which combines the predicting result of multi-domain feature with the predicting result of spike rate feature to detect the occurrence of epileptic seizures. After segmenting EEG data into 5[Formula: see text]s with 80% overlap epochs, the paper extracts time domain features, frequency domain features and hurst exponents (HE) from each epoch and these features are reduced by linear discriminant analysis (LDA) to be input parameters of the random forest (RF) classifier, which provides classification of the EEG epochs concerning the existence of seizures. In parallel, the paper extracts spikes from EEG data with morphological filter and calculates the spike rate to determine whether there is seizure. Then the results obtained by these two methods are merged as the final detection result. The paper shows that the accuracy (AC), sensitivity (SE), specificity (SP) and the false positive ratio based on event (FPRE) obtained by hybrid method are 98.94%, 76.60%, 98.99% and 2.43 times/h, respectively. Finally, the paper applies the seizure detection method to do seizure warning and recording to help the family member to take care of the patients and the doctor to adjust the antiepileptic drugs (AEDs).
Time-Frequency-Domain Copula-Based Granger Causality and Application to Corticomuscular Coupling in Stroke
Authors: She Qingshan , Zheng Hang , Tan Tongcai , Zhang Botao , Fan Yingle , Luo Zhizeng
Published: June 2019

The corticomuscular coupling (CMC) characterization between the motor cortex and muscles during motion control is a valid biomarker of motor system function after stroke, which can improve clinical decision-making. However, traditional CMC analysis is mainly based on the coherence method that can’t determine the coupling direction, whereas Granger Causality (GC) is limited in identifying linear cause–effect relationship. In this paper, a time-frequency domain copula-based GC (copula-GC) method is proposed to assess CMC characteristic. The 32-channel electroencephalogram (EEG) signals over brain scalp and electromyography (EMG) signals from upper limb were recorded during controlling and maintaining steady-state force output for five stroke patients and five healthy controls. Then, the time-frequency copula-GC analysis was applied to evaluate the CMC strength in both directions. Experimental results show that the CMC strength of descending direction is greater than that of ascending direction in the time domain for healthy controls. With the increase of grip strength, the bi-directional CMC strength has an increasing trend. Meanwhile, the bi-directional CMC strength of right hand is larger than that of left hand. In addition, the bi-directional CMC strength of stroke patients is lower than that of healthy controls. In the frequency domain, the strongest CMC is observed at the beta frequency band. Additionally, the CMC strength of descending direction is slightly larger than that of ascending direction in healthy controls, while the CMC strength of descending direction is lower than that of ascending direction in stroke patients. We suggest that the proposed time-frequency domain analysis approach based on copula-GC can effectively detect complex functional coupling between cortical oscillations and muscle activities, and provide a potential quantitative analysis measure for motion control and rehabilitation evaluation.
Numerical local upscaling of elastic geomechanical properties for heterogeneous continua
Authors: Zhang Bo , Deisman Nathan , Khajeh Mehdi , Chalaturnyk Rick , Boisvert Jeff
Published: June 2019

An efficient, numerical local upscaling technique for estimating elastic geomechanical properties in heterogeneous continua is proposed. The upscaled anisotropic elastic properties are solved locally with various boundary conditions and reproduce the anisotropic geomechanical response of fine-scale simulations of sand–shale sequence models with horizontal and inclined shale bedding planes. The algorithm is automated in a parallel program and can be used to determine optimum upscaling ratios in different regions of the reservoir. The successful application of the proposed upscaling method in a field-scale coupled reservoir–geomechanics simulation demonstrates an improvement in overall computational efficiency while maintaining accuracy in the geomechanical response and reservoir performance.
We need to know
Authors: Easley Nia
Published: June 2019

This forum highlights conversations at the intersection of design methods and social studies of technology. By highlighting a diversity of perspectives on design interventions and programs, we aim to forge new connections between HCI design and communication, science and technology studies, and media studies scholarship.
--- Daniela Rosner, Editor
Toward unified guidelines for kiosk accessibility
Authors: Lazar Jonathan , Jordan J. Bern , Vanderheiden Gregg
Published: June 2019

We have had the honor of serving the SIGCHI community as columnists and editors since the fifth issue of
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back in 1995. It has truly been a privilege to find and work with authors to help them find their voices. We hope that the Business column (1995--2011) and the Evaluation and Usability/UX in Practice forum (2011--present) have been useful to you, the readers. We wish the leadership of
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Susan Dray and David Siegel, Editors
An outside-the-box activity to demonstrate how humans and animals turn
Authors: Bye Thomas K. , Carter Kathryn R. , Carrier David R. , Elmer Steven J.
Published: June 2019

Developing hands-on activities that engage and excite K–12 students is critical for stimulating interest in science-based careers. We created an activity for high school students that required them to integrate biology and physics concepts to experience how humans and animals maneuver through their environments (i.e., turning). Understanding how turning works is important because it accounts for up to 50% of daily walking steps and is needed for survival when animals elude predators and capture prey. For this activity, student groups used 2 × 4 lumber, wood screws, and a power drill to build an apparatus that, when connected to the body, altered rotational inertia (object’s resistance to change in angular motion, I = mass × radius2). Students navigated through a slalom course with the apparatus (increased radius and rotational inertia) and without the apparatus (mass-matched control). Times to complete the course were compared between trials to determine the influence of rotational inertia on turning performance. Students compiled their data, graphed their results, and found that increased rotational inertia decreased turning performance. Results were connected to sports, rehabilitation, and dinosaur evolution. This activity was implemented during local, regional, national, and international outreach events and adapted for use in undergraduate courses as well (total impact, 250 students). At the end of the activity, students were able to 1) describe whether their results supported their hypothesis; 2) explain how radius influences rotational inertia and turning performance; and 3) apply results to real-world examples. Students and teachers appreciated this “outside-the-box” activity with an engineering twist and found it entertaining.
Analysis of Hull Girder Ultimate Strength and Residual Strength Based on IACS CSR‐H
Authors: Shi Gui-jie , Gao Da-wei , Zhou Hong
Published: June 2019

In order to express the safety level of hull structures, IACS Common Structure Rules of Bulk Carriers and Oil Tankers (CSR‐H) makes new requirements of hull girder ultimate strength. Compared with original CSR (i.e., CSR‐OT and CSR‐BC), partial safety factors of hull girder ultimate strength in CSR‐H have been partly modified, and new requirements of residual strength have been added in the rules for hull safety after grounded/collided damage. This paper compares the rule requirements of ultimate strength in CSR‐H and CSR‐OT/CSR‐BC and explains the technical background of rule requirements. The hull girder ultimate strength is mainly analyzed by SMITH method in rule requirements due to fast and stable calculation results. This paper also uses nonlinear finite element method (NFEM) to explain the critical influence factors for hull girder ultimate strength implied in the rule requirements. Based on 5 typical Bulk Carriers and 4 typical Oil Tankers, the influence of hull girder ultimate strength and residual strength in CSR‐H has been evaluated for ship building industry. The actual ship evaluation results can be used to instruct the new CSR‐H ship design.
A New Constitutive Relation for Describing the Flow through Porous Media with Unsaturated–Saturated Transition
Authors: Martins-Costa Maria Laura , Cunha da Silva Daniel , Cunha da Silva Michele , Martins Saldanha da Gama Rogério
Published: June 2019

The present work proposes an adequate constitutive relation to treat the process of filling with a fluid porous medium. This relation assures the problem to remain hyperbolic when the porous medium is saturated by the fluid. When the fluid fraction reaches porosity, the proposed constitutive relation increases the porous matrix resistance to more fluid inlet due to an important feature: it is a continuous and differentiable function with first derivative being also an increasing function. This allows assuring that the fluid fraction may exceed the porosity only by a very small value, making the constitutive relation realistic. Some examples compare this new constitutive relation with previous ones, highlighting its advantages.
Multi‐Objective Reentrant Hybrid Flowshop Scheduling with Machines Turning on and off Control Strategy Using Improved Multi‐Verse Optimizer Algorithm
Authors: Geng Kaifeng , Ye Chunming , Cao Lei , Liu Li
Published: June 2019

This paper focuses on the multi‐objective optimization of the reentrant hybrid flowshop scheduling problem (RHFSP) with machines turning on and off control strategy. RHFSP exhibits significance in many industrial applications, but scheduling with both energy consumption consideration and reentrant concept is relatively unexplored at present. In this study, an improved Multi‐Objective Multi‐Verse Optimizer (IMOMVO) algorithm is proposed to optimize the RHFSP with objectives of makespan, maximum tardiness, and idle energy consumption. To solve the proposed model more effectively, a series of improved operations are carried out, including population initialization based on Latin hypercube sampling (LHS), individual position updating based on Lévy flight, and chaotic local search based on logical self‐mapping. In addition, a right‐shift procedure is used to adjust the start time of operations aiming to minimize the idle energy consumption without changing the makespan. Then, Taguchi method is utilized to study the influence of different parameter settings on the scheduling results of the IMOMVO algorithm. Finally, the performance of the proposed IMOMVO algorithm is evaluated by comparing it with MOMVO, MOPSO, MOALO, and NSGA‐II on the same benchmark set. The results show that IMOMVO algorithm can solve the RHFSP with machines turning on and off control strategy effectively, and in terms of convergence and diversity of non‐dominated solutions, IMOMVO is obviously superior to other algorithms. However, the distribution level of the five algorithms has little difference. Meanwhile, by turning on and off the machine properly, the useless energy consumption in the production process can be reduced effectively.
Upper Semicontinuity of Random Attractors for Nonautonomous Stochastic Reversible Selkov System with Multiplicative Noise
Authors: Guo Chunxiao , Guo Yanfeng , Li Xiaohan
Published: June 2019

In this paper, the existence of random attractors for nonautonomous stochastic reversible Selkov system with multiplicative noise has been proved through Ornstein-Uhlenbeck transformation. Furthermore, the upper semicontinuity of random attractors is discussed when the intensity of noise approaches zero. The main difficulty is to prove the asymptotic compactness for establishing the existence of tempered pullback random attractor.
Solution to PSPACE‐Complete Problem Using P Systems with Active Membranes with Time‐Freeness
Authors: Song Bosheng , Kong Yuan
Published: June 2019

P systems with active membranes are powerful parallel natural computing models, which were inspired by cell structure and behavior. Inspired by the parallel processing of biological information and with the idealistic assumption that each rule is completed in exactly one time unit, P systems with active membranes are able to solve computational hard problems in a feasible time. However, an important biological fact in living cells is that the execution time of a biochemical reaction cannot be accurately divided equally and completed in one time unit. In this work, we consider time as an important factor for the computation in P systems with active membranes and investigate the computational efficiency of such P systems. Specifically, we present a time‐free semiuniform solution to the quantified Boolean satisfiability problem (QSAT problem, for short) in the framework of P systems with active membranes, where the solution to such problem is correct, which does not depend on the execution time for the used rules.
Locally Most Powerful Test for the Random Coefficient Autoregressive Model
Authors: Bi Li , Lu Feilong , Yang Kai , Wang Dehui
Published: June 2019

In this article, we study the problem of testing the constancy of the coefficient in a class of stationary first‐order random coefficient autoregressive (RCAR(1)) model. We construct a new test statistic based on the locally most powerful‐type (LMP) test. Under the null hypothesis, we derive the limiting distribution of the proposed test statistic. In the simulation, we compare the power between LMP test and empirical likelihood (EL) test and find that the accuracy of using LMP is 6.7%, 28.8%, and 26.1% higher than that of EL test under normal, student’s t, and symmetric contamination errors, respectively. A real life data is given to illustrate the practical effectiveness of our test.