bluuebunny/crossref_metadata_2025 huggingface dataset:
Management of difficult-to-treatClostridioides difficilein a patient with chronic osteomyelitis
Authors: Sullivan Mikaela Highland , Boggiano Victoria Lynn , Smith Kelly Lacy
Published: March 2020

A 61-year-old male patient being treated with intravenous antibiotics for left foot osteomyelitis presented to the hospital septic, with several days of worsening abdominal pain, bloating and watery bowel movements. Investigation revealed that the patient had severe, treatment-resistantClostridioides difficilecolitis. He was initially treated with oral vancomycin and intravenous metronidazole, which was switched to oral fidaxomicin. After no improvement in the patient’s symptoms, he was treated with two faecal microbiota transplants. He was offered a third faecal microbiota transplant but declined. The patient was placed back on oral fidaxomicin and saw ultimate resolution of his symptoms. This case provides an example of a treatment pathway for refractoryC. difficileinfection.
Complete ejection of a ring sequestrum 8 years after external fixation of the tibia
Authors: Timmer Isabella Regina , Emmink Benjamin Lucas , Leenen Loek Petrus Hendrikus , Govaert Geertje Anna Maria
Published: March 2020

On the day of scheduled debridement for a persistent pin tract infection, a 23-year old man presented himself carrying a small bony ring sequestrum that had spontaneously ejected from his tibial wound 1 week earlier. Eight years prior to presentation, he was treated for an open crural fracture which was stabilised with an external fixator. Revision of the operation notes revealed that the placement of this external fixator was performed without predrilling.
Acute infrarenal aortic occlusion
Authors: Barsanti-Innes Brianna , Roche-Nagle Graham
Published: March 2020

Acute aortic occlusion (AAO) is an uncommon but potentially devastating vascular emergency with reported perioperative mortality rates of up to 75%. We present the case of AAO in a 69-year-old woman who was transferred to our institution after presenting with sudden onset bilateral acute limb ischaemia. Imaging showed a completely obstructed aortoiliac segment with renal infarcts. She was treated successfully with aortoiliac over the wire thrombectomy.
Prevalence and causes of vision loss in sub-Saharan Africa in 2015: magnitude, temporal trends and projections
Authors: Naidoo Kovin , Kempen John H , Gichuhi Stephen , Braithwaite Tasanee , Casson Robert J , Cicinelli Maria Vittoria , Das Aditi , Flaxman Seth R , Jonas Jost B , Keeffe Jill Elizabeth , Leasher Janet , Limburg Hans , Pesudovs Konrad , Resnikoff Serge , Silvester Alexander J , Tahhan Nina , Taylor Hugh R , Wong Tien Y , Bourne Rupert R A
Published: March 2020

Background

This study aimed to assess the prevalence and causes of vision loss in sub-Saharan Africa (SSA) in 2015, compared with prior years, and to estimate expected values for 2020.

Methods

A systematic review and meta-analysis assessed the prevalence of blindness (presenting distance visual acuity <3/60 in the better eye), moderate and severe vision impairment (MSVI; presenting distance visual acuity <6/18 but ≥3/60) and mild vision impairment (MVI; presenting distance visual acuity <6/12 and ≥6/18), and also near vision impairment (<N6 or N8 in the presence of ≥6/12 best-corrected distance visual acuity) in SSA for 1990, 2010, 2015 and 2020.

In SSA, age-standardised prevalence of blindness, MSVI and MVI in 2015 were 1.03% (80% uncertainty interval (UI) 0.39–1.81), 3.64% (80% UI 1.71–5.94) and 2.94% (80% UI 1.05–5.34), respectively, for male and 1.08% (80% UI 0.40–1.93), 3.84% (80% UI 1.72–6.37) and 3.06% (80% UI 1.07–5.61) for females, constituting a significant decrease since 2010 for both genders. There were an estimated 4.28 million blind individuals and 17.36 million individuals with MSVI; 101.08 million individuals were estimated to have near vision loss due to presbyopia. Cataract was the most common cause of blindness (40.1%), whereas undercorrected refractive error (URE) (48.5%) was the most common cause of MSVI. Sub-Saharan West Africa had the highest proportion of blindness compared with the other SSA subregions.

Conclusions

Cataract and URE, two of the major causes of blindness and vision impairment, are reversible with treatment and thus promising targets to alleviate vision impairment in SSA.
Emergency first responder management of combat injuries to the torso in the military, remote and austere settings
Authors: Sandhu Amritpal , Claireaux H A , Downes G , Grundy N , Naumann D N
Published: March 2020

Traumatic injuries to the torso account for almost a quarter of all injuries seen in combat and are typically secondary to blast or gunshot wounds. Injuries due to road traffic collisions or violence are also relatively common during humanitarian and disaster relief efforts. There may also be multiple injured patients in these settings, and surgical care may be limited by a lack of facilities and resources in such a non-permissive environment. The first responder in these scenarios should be prepared to manage patients with severe injuries to the torso. We aim to describe the management of these injuries in the military and austere environment, within the scope of practice of a level 5 registered prehospital practitioner.
Cohort profile: the Brain and Mind CentreOptymisecohort: tracking multidimensional outcomes in young people presenting for mental healthcare
Authors: Carpenter Joanne S , Iorfino Frank , Cross Shane , Nichles Alissa , Zmicerevska Natalia , Crouse Jacob J , Palmer Jake R , Whitton Alexis E , White Django , Naismith Sharon L , Guastella Adam J , Hermens Daniel F , Scott Jan , Scott Elizabeth M , Hickie Ian B
Published: March 2020

Purpose

The Brain and Mind Centre (BMC)Optymisecohort assesses multiple clinical and functional domains longitudinally in young people presenting for mental health care and treatment. Longitudinal tracking of this cohort will allow investigation of the relationships between multiple outcome domains across the course of care. Subsets ofOptymisehave completed detailed neuropsychological and neurobiological assessments, permitting investigation of associations between these measures and longitudinal course.

Participants

Young people (aged 12–30) presenting to clinics coordinated by the BMC were recruited to a research register (n=6743) progressively between June 2008 and July 2018. To date, 2767 individuals have been included inOptymisebased on the availability of at least one detailed clinical assessment.

Measures

Trained researchers use a clinical research proforma to extract key data from clinical files to detail social and occupational functioning, clinical presentation, self-harm and suicidal thoughts and behaviours, alcohol and other substance use, physical health comorbidities, personal and family history of mental illness, and treatment utilisation at the following time points: baseline, 3, 6, 12, 24, 36, 48, and 60 months, and time last seen.

Findings to date

There is moderate to substantial agreement between raters for data collected via the proforma. While wide variations in individual illness course are clear, social and occupational outcomes suggest that the majority of cohort members show no improvement in functioning over time. Differential rates of longitudinal transition are reported between early and late stages of illness, with a number of baseline factors associated with these transitions. Furthermore, there are longitudinal associations between prior suicide attempts and inferior clinical and functional outcomes.

Future plans

Future reports will detail the longitudinal course of each outcome domain and examine multidirectional relationships between these domains both cross-sectionally and longitudinally, and explore in subsets the associations between detailed neurobiological measures and clinical, social and functional outcomes.
Association of prestroke medicine use and health outcomes after ischaemic stroke in Sweden: a registry-based cohort study
Authors: Ingrid Lekander , von Euler Mia , Sunnerhagen Katharina S
Published: March 2020

Objective

The objective was to investigate if there is a relationship between preischaemic stroke medicine use and health outcomes after stroke.

Setting

This registry-based study covered Swedish stroke care, both primary and secondary care, including approximately 60% of the Swedish stroke cases from seven Swedish regions.

Participants

The Sveus research database was used, including 35 913 patients (33 943 with full information on confounding factors) with an ischaemic stroke (International Classification of Diseases, 10th Revision (ICD-10) I63*) between 2009 and 2011 registered both in the regions’ patient administrative systems and in the Swedish Stroke Register. Patients with haemorrhagic stroke (ICD-10 I61*) were excluded.

Primary outcome

The primary outcome was the association, expressed in ORs, of prestroke medicine use (oral anticoagulants, statins, antihypertensives, antidepressants, non-steroidal anti-inflammatory drugs (NSAIDs) and antidiabetic drugs) and health outcomes 1 and 2 years poststroke (survival, activities of daily living dependency and modified Rankin Scale (mRS) 0–2), adjusted for patient characteristics and stroke severity at stroke onset.

Results

The multivariate analysis indicated that patients on drugs for hypertension, diabetes, oral anticoagulants and antidepressants prestroke had worse odds for health outcomes in both survival (OR 0.65, 95% CI 0.60 to 0.69; OR 0.77, 95% CI 0.71 to 0.83; OR 0.72, 95% CI 0.66 to 0.80; OR 0.91, 95% CI 0.84 to 0.98, respectively, for survival at 2 years) and functional outcome (OR 0.82, 95% CI 0.75 to 0.89; OR 0.61, 95% CI 0.55 to 0.68; OR 0.83, 95% CI 0.72 to 0.95; OR 0.58, 95% CI 0.52 to 0.65, respectively, for mRS 0–2 at 1 year), whereas patients on statins and NSAIDS had significantly better odds for survival (OR 1.16, 95% CI 1.08 to 1.25 and OR 1.12, 95% CI 1.00 to 1.25 for 1-year survival, respectively), compared with patients without these treatments prior to stroke.

Conclusions

The results indicated that there are differences in health outcomes between patients who had different common prestroke treatments, patients on drugs for hypertension, diabetes, oral anticoagulants and antidepressants had worse health outcomes, whereas patients on statins and NSAIDS had significantly better survival, compared with patients without these treatments prior to stroke.
Evaluating the influence of data collector training for predictive risk of death models: an observational study
Authors: Rajamani Arvind , Huang Stephen , Subramaniam Ashwin , Thomson Michele , Luo Jinghang , Simpson Andrew , McLean Anthony , Aneman Anders , Madapusi Thodur Vinodh , Lakshmanan Ramanathan , Flynn Gordon , Poojara Latesh , Gatward Jonathan , Pusapati Raju , Howard Adam , Odlum Debbie
Published: March 2020

Background

Severity-of-illness scoring systems are widely used for quality assurance and research. Although validated by trained data collectors, there is little data on the accuracy of real-world data collection practices.

Objective

To evaluate the influence of formal data collection training on the accuracy of scoring system data in intensive care units (ICUs).

Study design and methods

Quality assurance audit conducted using survey methodology principles. Between June and December 2018, an electronic document with details of three fictitious ICU patients was emailed to staff from 19 Australian ICUs who voluntarily submitted data on a web-based data entry form. Their entries were used to generate severity-of-illness scores and risks of death (RoDs) for four scoring systems. The primary outcome was the variation of severity-of-illness scores and RoDs from a reference standard.

Results

50/83 staff (60.3%) submitted data. Using Bayesian multilevel analysis, severity-of-illness scores and RoDs were found to be significantly higher for untrained staff. The mean (95% high-density interval) overestimation in RoD due to training effect for patients 1, 2 and 3, respectively, were 0.24 (0.16, 0.31), 0.19 (0.09, 0.29) and 0.24 (0.1, 0.38) respectively (Bayesian factor >300, decisive evidence). Both groups (trained and untrained) had wide coefficients of variation up to 38.1%, indicating wide variability. Untrained staff made more errors in interpreting scoring system definitions.

Interpretation

In a fictitious patient dataset, data collection staff without formal training significantly overestimated the severity-of-illness scores and RoDs compared with trained staff. Both groups exhibited wide variability. Strategies to improve practice may include providing adequate training for all data collection staff, refresher training for previously trained staff and auditing the raw data submitted by individual ICUs. The results of this simulated study need revalidation on real patients.
HBV vaccination and HBV infection induces HBV-specific natural killer cell memory
Authors: Wijaya Ratna S , Read Scott A , Truong Naomi R , Han Shuanglin , Chen Dishen , Shahidipour Haleh , Fewings Nicole L , Schibeci Stephen , Azardaryany Mahmoud K , Parnell Grant P , Booth David , van der Poorten David , Lin Rita , George Jacob , Douglas Mark W , Ahlenstiel Golo
Published: March 2020

Objective

Vaccination against hepatitis B virus (HBV) confers protection from subsequent infection through immunological memory that is traditionally considered the domain of the adaptive immune system. This view has been challenged following the identification of antigen-specific memory natural killer cells (mNKs) in mice and non-human primates. While the presence of mNKs has been suggested in humans based on the expansion of NK cells following pathogen exposure, evidence regarding antigen-specificity is lacking. Here, we demonstrate the existence of HBV-specific mNKs in humans after vaccination and in chronic HBV infection.

Design

NK cell responses were evaluated by flow cytometry and ELISA following challenge with HBV antigens in HBV vaccinated, non-vaccinated and chronic HBV-infected individuals.

Results

NK cells from vaccinated subjects demonstrated higher cytotoxic and proliferative responses against autologous hepatitis B surface antigen (HBsAg)-pulsed monocyte-derived dendritic cells (moDCs) compared with unvaccinated subjects. Moreover, NK cell lysis of HBsAg-pulsed moDCs was significantly higher than that of hepatitis B core antigen (HBcAg)-pulsed moDCs (non-vaccine antigen) or tumour necrosis factor α-activated moDCs in a NKG2D-dependent manner. The mNKs response was mediated by CD56dim NK cells coexpressing CD57, CD69 and KLRG1. Further, mNKs from chronic hepatitis B patients exhibited greater degranulation against HBcAg-pulsed moDCs compared with unvaccinated or vaccinated patients. Notably, mNK activity was negatively correlated with HBV DNA levels.

Conclusions

Our data support the presence of a mature mNKs following HBV antigen exposure either through vaccination or infection. Harnessing these antigen specific, functionally active mNKs provides an opportunity to develop novel treatments targeting HBV in chronic infection.
Technological moral enhancement or traditional moral progress? Why not both?
Authors: Fabiano Joao
Published: March 2020

A new argument has been made against moral enhancement by authors who are otherwise in favour of human enhancement. Additionally, they share the same evolutionary toolkit for analysing human traits as well as the belief that our current morality is unfit to deal with modern problems, such as climate change and nuclear proliferation. The argument is put forward by Buchanan and Powell and states that other paths to moral progress are enough to deal with these problems. Given the likely costs and risks involved with developing moral enhancement, this argument implies moral enhancement is an unpromising enterprise. After mentioning proposed solutions to such modern problems, I will argue that moral enhancement would help implement any of them. I will then detail Buchanan and Powell’s new argument disfavouring moral enhancement and argue that it makes too bold assumptions about the efficacy of traditional moral progress. For instance, it overlooks how that progress was to achieve even in relatively successful cases such as the abolition of slavery. Traditional moral progress is likely to require assistance from non-traditional means in order to face new challenges.
Selective embolization of the mastoid emissary vein for pulsatile tinnitus treatment: when is it indicated?
Authors: Eliezer Michael , Freitas Rafael Kiyuze , Fantoni Matteo , Guedon Alexis , Houdart Emmanuel
Published: March 2020

Background

Venous pulsatile tinnitus (PT) can be caused by the perception of blood flow through the mastoid emissary vein (MEV). However, the causal relationship of this anomaly has not been established as selective occlusion of this vein has never been performed. The aim of this study was to report on a small series of patients suspected of having PT caused by an MEV, who underwent MEV embolization as treatment for PT, and to identify the correct indications for this procedure.

Methods

This was a single center retrospective study (CNIL 2215065) including six patients with isolated disabling PT treated by embolization of the MEV, recruited between December 2017 and August 2019. Patient charts were systematically reviewed. All patients underwent non-contrast temporal bone CT and MRI.

Results

Mean age of the patients (five women, one male) was 56.3 years (range 40–71 years). Two patients presented with venous PT and four had neutral PT. The MEV was in direct contact with the mastoid air cells on temporal bone CT in all patients. Based on clinical examination, two patients presented with venous PT while four patients had neutral PT. In all cases of venous PT, selective embolization of the MEV caused the tinnitus to disappear, suggesting technical success. In contrast, embolization of the MEV had no effect in patients with neutral PT.

Conclusions

We demonstrated that MEV could be a source of venous PT. Embolization of the MEV was effective only in cases of clinical venous PT.
Raman and AFM-IR chemical imaging of stratum corneum model membranes
Authors: Paz Ramos Adrian , Gooris Gert , Bouwstra Joke , Molinari Michael , Lafleur Michel
Published: March 2020

Stratum corneum (SC), the outermost layer of the epidermis, is the primary barrier to percutaneous absorption. The diffusion of substances through the skin occurs through the SC lipid fraction, which is essentially constituted of an equimolar mixture of ceramides, free fatty acids, and cholesterol. The lipid constituents of SC are mainly forming continuous multilamellar membranes in the solid/crystalline state. However, recent findings suggest the presence of a highly disordered (liquid) phase formed by the unsaturated C18 chain of ceramide EOS, surrounded by a highly ordered lipid environment. The aim of the present work was to study the lipid spatial distribution of model SC membranes composed of ceramide EOS, ceramide NS, a mixture of free fatty acids, and cholesterol, using Raman microspectroscopy and AFM-IR spectroscopy techniques. The enhanced spatial resolution at the tens of nanometers scale of the AFM-IR technique revealed that the lipid matrix is overall homogeneous, with the presence of small, slightly enriched, and depleted regions in a lipid component. No liquid domains of ceramide EOS were observed at this scale, a result that is consistent with the model proposing that the oleate nanodrops are concentrated in the central layer of the three-layer organization of the SC membranes forming the long periodicity phase. In addition, both Raman microspectroscopy and AFM-IR techniques confirmed the fluid nature of the unsaturated chain of ceramide EOS while the rest of the lipid matrix was found highly ordered.
The age of the Tseax volcanic eruption, British Columbia, Canada
Authors: Williams-Jones Glyn , Barendregt René W. , Russell James K. , Le Moigne Yannick , Enkin Randolph J. , Gallo Rose
Published: March 2020

A recent volcanic eruption occurred at Tseax volcano that formed a series of tephra cones in northwestern British Columbia, Canada. The explosive to effusive eruption also formed a 32 km long sequence of Fe-rich Mg-poor basanite–trachybasalt lavas covering ∼40 km2. Oral histories of the Nisg_a’a Nation report that the eruption may have caused as many as 2000 fatalities. The actual eruption date and question of whether there was one or multiple eruptive episodes in the 14th and 18th centuries are, as of yet, unresolved. New radiocarbon dating of wood charcoal from immediately beneath vent-proximal tephra deposits and complementary age information suggest an eruption in 1675–1778 CE (95.4% probability) was responsible for the formation of the tephra cone. New paleomagnetic and geochemical data from the tephra cone and lava flows suggest there is, in fact, no statistically significant difference in time between the explosive and effusive deposits and that they formed during a single eruptive episode.
Experimental investigation of a ground-coupled heat exchanger combined with an air conditioner for southern India
Authors: Damodharan Arunkumar , Murugan Ramu , Abuthakeer Syath
Published: March 2020

Increasing the energy ratio of an air conditioner that has a cooled air condenser is a difficult problem, particularly in areas where the temperature and humidity are very high. The efficiency of air conditioners based on standard vapor compression technology can be enhanced by combining active cooling technologies with less energy-intensive inactive cooling technologies. In this study, the cooling performance of combined cooling systems has been experimentally explored. Using four different modes of a hybrid ground-coupled heat exchanger (GCHE), an analysis was carried out to enhance the energy ratio of the active cooling system connected to the GCHE. This was achieved by using the fact that the GCHE outlet air temperature is lower than the ambient temperature and can directly supply space heating or cooling to the condenser tubes of conventional air conditioners. It was observed that with the use of a GCHE for the condenser tubes, the energy consumption of a traditional window air conditioner was reduced by 16.18%.
Isolating the Odderon in central production in high energy pA and AA collisions
Authors: McNulty R. , Khoze V. A. , Martin A. D. , Ryskin M. G.
Published: March 2020

We study the rapidity dependence of the central exclusive production cross sections of C-even mesons inpAandAAcollisions, whereAis a heavy ion. We observe qualitatively different behaviour of the contributions arising from$$\gamma $$γ-Odderon and Pomeron–Pomeron fusion mechanisms. This can be used to extract the Odderon signal from the events of$$f_2$$f2mesons exclusively produced in the forward region. Estimates, obtained using expected values of the Odderon cross section, indicate that the$$\gamma $$γ-Odderon contribution may exceed by a few times the Pomeron-induced background in Pb–Pb collisions. Moreover, the Odderon effect can be clearly seen in terms of the asymmetry inpAandAAcollisions with the beam and target reversed. It is particularly interesting to note that the asymmetry for$$\gamma $$γ-Odderon fusion reaches its maximum value close to 1 in the forward direction, whereas the asymmetry for the Pomeron–Pomeron fusion contribution is small. The role of additional interactions of the$$f_2$$f2meson with nucleons in the heavy ion, and also the contributions from secondary Reggeons, are estimated. The photon–Odderon contribution has a large normalisation uncertainty but the enhanced cross-section in the forward region combined with a large asymmetry increases the chance of experimentally detecting the Odderon.
Dyslexia Diagnosis by EEG Temporal and Spectral Descriptors: An Anomaly Detection Approach
Authors: Ortiz Andrés , Martinez-Murcia Francisco J. , Luque Juan L. , Giménez Almudena , Morales-Ortega Roberto , Ortega Julio
Published: March 2020

Diagnosis of learning difficulties is a challenging goal. There are huge number of factors involved in the evaluation procedure that present high variance among the population with the same difficulty. Diagnosis is usually performed by scoring subjects according to results obtained in different neuropsychological (performance-based) tests specifically designed to this end. One of the most frequent disorders is developmental dyslexia (DD), a specific difficulty in the acquisition of reading skills not related to mental age or inadequate schooling. Its prevalence is estimated between 5% and 12% of the population. Traditional tests for DD diagnosis aim to measure different behavioral variables involved in the reading process. In this paper, we propose a diagnostic method not based on behavioral variables but on involuntary neurophysiological responses to different auditory stimuli. The experiments performed use electroencephalography (EEG) signals to analyze the temporal behavior and the spectral content of the signal acquired from each electrode to extract relevant (temporal and spectral) features. Moreover, the relationship of the features extracted among electrodes allows to infer a connectivity-like model showing brain areas that process auditory stimuli in a synchronized way. Then an anomaly detection system based on the reconstruction residuals of an autoencoder using these features has been proposed. Hence, classification is performed by the proposed system based on the differences in the resulting connectivity models that have demonstrated to be a useful tool for differential diagnosis of DD as well as a method to step towards gaining a better knowledge of the brain processes involved in DD. The results corroborate that nonspeech stimulus modulated at specific frequencies related to the sampling processes developed in the brain to capture rhymes, syllables and phonemes produces effects in specific frequency bands that differentiate between controls and DD subjects. The proposed method showed relatively high sensitivity above 0.6, and up to 0.9 in some of the experiments.
How can we reach consensus? The answer from the micro-configurations of a 2-D Ising model
Authors: Wang Peng , Ai Hui , Huo Jie , Pan Feng-Chun , Wang Xu-Ming
Published: March 2020

We study opinion formation by uncovering the relevant aspects hiding in the distribution of micro-configurations in a 2-D Ising model. The external field denotes the external influence such as guiding viewpoint, and temperature represents randomness of the agents. The full-positive configuration or the full-negative configuration means consensus. We find that the probability of the full-positive configuration and the full-negative configuration can reach [Formula: see text] (which implies the equal splitting of a group) if the interaction is strong enough and the system is free from external field; the probability of the full-positive configuration can reach 1 (which means consensus) if the positive external field is strong enough under condition of given interaction and temperature. These phenomena are regarded as the reversing mechanism of the full-negative configuration induced by the external field — an opinion reversal. The equal splitting and consensus can be broken down as temperature rises. We discuss the dependence of interaction strength [Formula: see text] (with which the equal splitting occurs) on temperature [Formula: see text], the dependence of external field strength [Formula: see text] (with which the consensus occurs) on interaction strength [Formula: see text] at a certain temperature, as well as the scaling relations responsible for the probability of the full-negative configuration varying with temperature under different conditions. The findings provide us with a good description to understand opinion formation.
Review of video compression techniques based on fractal transform function and swarm intelligence
Authors: Pandit Shraddha , Shukla Piyush Kumar , Tiwari Akhilesh , Shukla Prashant Kumar , Maheshwari Manish , Dubey Rachana
Published: March 2020

Data processing with multiple domains is an important concept in any platform; it deals with multimedia and textual information. Where textual data processing focuses on a structured or unstructured way of data processing which computes in less time with no compression over the data, multimedia data are processing deals with a processing requirement algorithm where compression is needed. This involve processing of video and their frames and compression in short forms such that the fast processing of storage as well as the access can be performed. There are different ways of performing compression, such as fractal compression, wavelet transform, compressive sensing, contractive transformation and other ways. One way of performing such a compression is working with the high frequency component of multimedia data. One of the most recent topics is fractal transformation which follows the block symmetry and archives high compression ratio. Yet, there are limitations such as working with speed and its cost while performing proper encoding and decoding using fractal compression. Swarm optimization and other related algorithms make it usable along with fractal compression function. In this paper, we review multiple algorithms in the field of fractal-based video compression and swarm intelligence for problems of optimization.
Catalytic etching of {100}-oriented diamond coating with Ni and Cu nanoparticles under hydrogen
Authors: Cui Naiyuan , Wang Fei , Guo Lei
Published: March 2020

Nanopores formed in insulating solid state membrane is of great importance in many fields such as detection of DNA/RNA molecules in their internal environment, probing and manipulating biopolymers. Here, we present an effective and convenient method to form nanopores in diamond etched by self-assembled Ni or Cu nanoparticles in hydrogen atmosphere. With our method, homogeneous nanopores with lateral size in the range of [Formula: see text]–[Formula: see text] were created without using Reactive Ion Etching (RIE) process. In this work, the etching pits of Ni and Cu etched diamond were investigated, respectively. A novel step-like pattern of etching pits was observed on diamond etched by Ni. In order to study the etching process and figure out the etching mechanism of diamond, Scanning Electron Microscopy (SEM) was used to observe the etching morphology. Atomic Force Microscopy (AFM) and Laser Scanning Confocal Microscope (LSCM) were used to visualize the image of diamond etching pits and investigate the step-like pattern. A fixed step height was observed in each pit. Based on these observations and findings, a hypothesis is proposed, which can help to provide a new controllable etching method.
A triple-channel incremental zoom-ADC for 3-DoF MEMS digital gyroscopes
Authors: Lv Risheng , Chen Weiping , Fu Qiang , Yin Liang , Zhang Yufeng , Liu Xiaowei
Published: March 2020

This paper presents a multiplexed analog-to-digital converter (ADC) consisting mainly of high-precision sampling holders (S/H) and an incremental zoom ADC. Flip-around design is employed in S/H modules for power economy and noise suppression. Based on efficient coordination between S/H and multiplexers, synchronous sampling is available in the whole triple-channel ADC to maintain phase accordance. The core converter employed a hybrid architecture of successive approximation register (SAR) and Sigma-Delta [Formula: see text], which constitutes an energy-efficient zoom ADC. Final conversion result is a combination of the two steps. Both the SAR and [Formula: see text] modulation share a third-order loop filter to compromise between systematic stability and input range. On-chip digital logic include capacitor array controlling and dynamic-element-matching (DEM) technique. Manufactured in a standard [Formula: see text]m CMOS technology, the whole chip occupies an area of 2.7 mm2. Experimental results show a maximum signal-to-noise ratio (SNR) of 100.2 dB, with a power consumption of 2.1 mW from a 5 V supply.
Finite-time synchronization for fractional-order memristor-based neural networks with discontinuous activations and multiple delays
Authors: Ding Dawei , You Ziruo , Hu Yongbing , Yang Zongli , Ding Lianghui
Published: March 2020

This paper addresses the finite-time synchronization problem for fractional-order memristor-based neural networks (FMNNs) with discontinuous activations, in which multiple delays are considered. Firstly, on the basis of set-valued mapping as well as differential inclusions theory, the synchronization issue of drive-response systems is considered as the stabilization of the error system. Then, the state feedback controllers, which contain both discontinuous part and time-delayed part, are designed to analyze the finite-time synchronization of the concerned network model. Making use of the stability theorem of fractional-order systems with multiple time delays, some fractional derivative inequalities and comparison theorem, several sufficient criteria are established for confirming that the synchronization error of the concerned system can reach zero within a limited time. Additionally, the settling time can be optimized by adjusting controller parameter. Finally, the effectiveness of synchronization strategies is validated through the simulation results.
A double cantilever beam incorporating cohesive crack modeling for superconductors
Authors: Wang K. F. , Wang Y. Q. , Wang B. L. , Zheng L.
Published: March 2020

In this paper, a double cantilever beam (DCB) specimen incorporating cohesive crack is developed for superconductors which have potential applications in high temperature superconducting cables in space solar power station. The cohesive interface is introduced along the crack front of the DCB model under electromagnetic force. The load-separation relation (i.e. the crack opening displacement) is used as the fracture mechanics parameter and the corresponding curves during fracture process are obtained and verified by the finite element numerical method. Results show that the presence of tensile electromagnetic force makes crack propagate easily. Superconductors with small cracks have good adaptability to the oscillation of magnetic fields while that with large cracks are easier to fracture during the descent of the magnetic field. In addition, the ductility ratio of the cohesive interface can significantly increase the fracture strength. The length of fracture zone decreases as the crack length increases.
Broadband gradient phase discontinuity all-dielectric metasurface
Authors: Liu Yahong , Li Meize , Song Kun , Jing Yuhao , Guo Jiale , Hai Qingyu , Zhao Xiaopeng
Published: March 2020

In recent years, metasurfaces have widely been studied due to their ability to offer a spatially varying phase response, low losses, ultrathin size, and easy fabrication. In this paper, a gradient phase discontinuity all-dielectric metasurface consisting of arrays of silicon cube resonator is designed. By adjusting the dimension of the silicon cube resonator, a [Formula: see text] transmission phase covered from [Formula: see text] to [Formula: see text] with [Formula: see text] phase intervals is realized in a frequency from 9.7 GHz to 11.8 GHz. We demonstrate the all-dielectric metasurface can produce the anomalous refraction, vortex beams, and wave-focusing in the microwave and infrared band, respectively. It can be expected that the proposed metasurfaces can find wide applications in communication, designing integrated optical devices, and focusing lenses.
Rank-One Chaos in a Periodically Kicked Three-Species Food Chain with Time-Delay
Authors: Yang Ping , Fang Juan , Dai Yunxian , Lin Yiping
Published: March 2020

This paper is devoted to studying the problem of rank-one strange attractor in a three-species food chain with time-delay. The conditions for the existence of positive equilibrium and Hopf bifurcation are presented. By using the theory of rank-one maps formulated by Wang and Young in 2001, and then developed by us to the time-delayed system, the conditions for the system having rank-one strange attractor are obtained under periodically kicked system. Numerical simulations are presented to demonstrate the analytic results.
Synergetics and Acoustic Emission Approach for Crazing Nonlinear Dynamical Systems
Authors: Gao Guodong , Xing Yongming
Published: March 2020

This paper reports that synergetics are used to analyze the crazing evolution. On this basis, chaotic effect is explored. The chaos equation is established and verified. The theoretical derivation are consistent with the experimental results. We design a special specimen with a special loading mode, the transient monitoring function of acoustic emission (AE) technology is used to track and detect the crazing inside the PMMA in real time, and the experiments show that synergetics can explain the crazing properties of polymer. Importantly, the mathematical explanation is also given. The AE analysis, synergetics, and craze photo reached a conclusion that the crazing has chaotic behavior. After analyzing the AE events and crazing at different stress levels, the accuracy of synergetic approach for crazing is verified. By studying the course of AE events and crazing, the self-organization effect is proposed. The research results will provide data support for the application of PMMA in ship, aircraft, and precision instruments.
The Long-Term Periodic Patterns of Global Rabies Epidemics Among Animals: A Modeling Analysis
Authors: Musa Salihu Sabiu , Zhao Shi , He Daihai , Liu Chao
Published: March 2020

Rabies remains a serious threat to public health in Asia, Africa and some parts of Europe with a case fatality rate of 95%. We adopted wavelet analysis to study the long-term recurrence of global rabies outbreaks and found that a 3- to 4-year periodicity has existed since 2005. Furthermore, a simple compartmental model is developed and analyzed to study the transmission dynamics, and to show the existence of the observed periodicity as well as the endemic feature of rabies among animals. Our findings indicate the existence of the oscillation patterns (recurrence), and the epidemic is at its peak since 2018.
Multiple asymptotics of kinetic equations with internal states
Authors: Perthame Benoit , Sun Weiran , Tang Min , Yasuda Shugo
Published: March 2020

The run and tumble process is well established in order to describe the movement of bacteria in response to a chemical stimulus. However, the relation between the tumbling rate and the internal state of bacteria is poorly understood. This study aims at deriving macroscopic models as limits of the mesoscopic kinetic equation in different regimes. In particular, we are interested in the roles of the stiffness of the response and the adaptation time in the kinetic equation. Depending on the asymptotics chosen both the standard Keller–Segel equation and the flux-limited Keller–Segel (FLKS) equation can appear. An interesting mathematical issue arises with a new type of equilibrium equation leading to solution with singularities.
Global radial renormalized solution to a producer–scrounger model with singular sensitivities
Authors: Cao Xinru
Published: March 2020

This paper is concerned with the parabolic system [Formula: see text] in a bounded ball [Formula: see text] ([Formula: see text]) with [Formula: see text]. Where [Formula: see text] and [Formula: see text]. It is shown that for arbitrarily radially symmetric initial data [Formula: see text], which are nonnegative and suitably regular, the corresponding Neumann initial-boundary problem admits a global renormalized solution, which is moreover smooth in [Formula: see text].
A general cell–fluid Navier–Stokes model with inclusion of chemotaxis
Authors: Qiao Yangyang , Evje Steinar
Published: March 2020

The main purpose of this work is to explore a general cell–fluid model which is based on a mixture theory formulation that accounts for the interplay between oxytactically (chemotaxis toward gradient in oxygen) moving bacteria cells in water and the buoyance forces caused by the difference in density between cells and fluid. The model involves two mass balance and two general momentum balance equations, respectively, for the cell and fluid phase, combined with a convection–diffusion–reaction equation for oxygen. In particular, the momentum balance equations include interaction terms which describe the cell–fluid drag force effect. Hence, the model is an extension of the classical Navier–Stokes equation in two different ways: (i) inclusion of two phases (cell and fluid) instead of one; (ii) inclusion of a chemotactic transport mechanism. The model can be understood as a natural generalization of the much studied chemotaxis-Stokes model explored by [I. Tuval, L. Cisneros, C. Dombrowski, C. W. Wolgemuth, J. O. Kessler and R. E. Goldstein, Bacterial swimming and oxygen transport near contact lines, Proc. Natl. Acad. Sci. USA 102 (2005) 2277–2282]. First, we explore the model for parameters in a range which ensures that it lies close to the previously studied chemotaxis-Stokes model (essentially very low cell volume fraction). Main observations are (i) formation of sinking finger-shaped plumes and (ii) convergence to plumes that possibly can be stationary (i.e. persist over time). The general cell–fluid model provides new insight into the role played by the cell–fluid interaction term which controls the competition between gravity segregation and chemotaxis effect on the formation of cell plumes. Second, we explore cases with large cell volume fraction (far beyond the regime captured by the chemotaxis-Stokes model), which gives rise to rich pattern-formation behavior. The general cell–fluid model opens for exploring a hierarchy of different “submodels”. Hence, it seems to be an interesting model for further investigations of various, general cell–fluid spatio-temporal evolution dynamics, both from an experimental and mathematical point of view.
Pseudofinite difference fields and counting dimensions
Authors: Zou Tingxiang
Published: March 2020

We study a family of ultraproducts of finite fields with the Frobenius automorphism in this paper. Their theories have the strict order property and TP2. But the coarse pseudofinite dimension of the definable sets is definable and integer-valued. Moreover, we also discuss the possible connection between coarse dimension and transformal transcendence degree in these difference fields.
Minimum norm interpolation in the ℓ1(ℕ) space
Authors: Cheng Raymond , Xu Yuesheng
Published: March 2020

We consider the minimum norm interpolation problem in the [Formula: see text] space, aiming at constructing a sparse interpolation solution. The original problem is reformulated in the pre-dual space, thereby inducing a norm in a related finite-dimensional Euclidean space. The dual problem is then transformed into a linear programming problem, which can be solved by existing methods. With that done, the original interpolation problem is reduced by solving an elementary finite-dimensional linear algebra equation. A specific example is presented to illustrate the proposed method, in which a sparse solution in the [Formula: see text] space is compared to the dense solution in the [Formula: see text] space. This example shows that a solution of the minimum norm interpolation problem in the [Formula: see text] space is indeed sparse, while that of the minimum norm interpolation problem in the [Formula: see text] space is not.
Enhancing the Nonlinear Optical Properties of Lithium Tetraborate Glass Using Rare Earth Elements and Silver Nanoparticles
Authors: Vallejo M. A. , Romero-Servin S. , Alvarez Moisés I. Casillas , Angel Janet A. Elias , Gomez-Solis C. , Álvarez-Valtierra Leonardo , Sosa M. A.
Published: March 2020

In recent years, nonlinear optics field is in constant growth, particularly on the characterization and study of optical properties of glass compounds. In this sense, the plasmonic effect caused by silver nanoparticles (SNP) on the nonlinear optical (NLO) properties of different materials was studied. Furthermore, we report the experimental absorption spectra, the emission spectra, Z-scan measurements in both closed and open apertures and scanning transmission electron microscopy (STEM) to show the morphology of the matrices and the nucleation of SNP. Moreover, some NLO parameters were calculated, such as the NL refraction index and NL coefficient absorption of lithium tetraborate (Li2B4O7) glass activated with rare earths (Dy3+ and Yb3+), as well as study of the effect of different concentrations of SNP. From the results obtained, it has been ascertained that the plasmon resonance caused by the presence of SNP enhances the NL refraction index value, as well as most of its linear optical properties in the matrix of Li2B4O7.
Role of Acetaldehyde on Synthesizing Large Surface Area Porous g-C3N4Nanosheets with Enhanced Photocatalytic Performance by Using Acetaldehyde–Melamine
Authors: Cheng Xiangxiang , Xu Xiaojuan , Wang Hongliang , Cai He , Jia Lan , Wang Xiaona , Ding Yong , Han Yu , Fan Xiaoxing
Published: March 2020

Large specific surface area porous g-C3N4nanosheets were prepared by utilizing acetaldehyde-mediated melamine. The synthetic processes adopted two-step thermal treatments which are in N2and then in an air atmosphere. The introduced acetaldehyde made melamine condensation incompletely and generated body defects in g-C3N4when heated in N2. Further heating in air realized pores formation at sites of body defects, thus increase the specific surface area of g-C3N4. Notably, the introduction of acetaldehyde is beneficial to generate high concentration defects, which are active sites for thermal oxidative etching, and increase the yield of g-C3N4by inhibiting the sublimation of melamine. The photocatalytic performance of obtained g-C3N4was evaluated by the degradation of 2-propanol under visible light irradiation ([Formula: see text][Formula: see text]nm). The porous g-C3N4exhibits excellent photocatalytic performance than bulk g-C3N4. The addition of trace acetaldehyde significantly increased the specific surface area and enhanced photocatalytic activity, providing a new idea for the development of simple, low-cost and high active g-C3N4photocatalyst.
Stability and bifurcation analysis for a delayed viral infection model with full logistic proliferation
Authors: Geng Yan , Xu Jinhu
Published: March 2020

In this paper, we study a delayed viral infection model with cellular infection and full logistic proliferations for both healthy and infected cells. The global asymptotic stabilities of the equilibria are studied by constructing Lyapunov functionals. Moreover, we investigated the existence of Hopf bifurcation at the infected equilibrium by regarding the possible combination of the two delays as bifurcation parameters. The results show that time delays may destabilize the infected equilibrium and lead to Hopf bifurcation. Finally, numerical simulations are carried out to illustrate the main results and explore the dynamics including Hopf bifurcation and stability switches.
Dynamics of a diffusive predator–prey system with ratio-dependent functional response and time delay
Authors: Jiang Xin , Zhang Ran , She Zhikun
Published: March 2020

In this paper, we investigate the qualitative behaviors of a predator–prey system with ratio-dependent function. The system accommodates the diffusion effect to model the migration of individuals and the time delay induced by reproduction. We start with some basic properties of the system. Then the sufficient condition independent of time delay and diffusion effect for global asymptotical stability of the boundary equilibrium is obtained by using the comparison principle. Afterwards, based on the LaSalle’s invariance principle and Lyapunov functional, we investigate the global attractiveness of the positive equilibrium, arriving at its global asymptotical stability. Further, Hopf bifurcation induced by time delay around the positive equilibrium is explored. Finally, numerical examples are listed to verify the corresponding analytical results.
On a special case of Wilf’s conjecture
Authors: Angjelkoska Violeta , Dimovski Donco
Published: March 2020

Let [Formula: see text] be a numerical semigroup with embedding dimension [Formula: see text], minimal set of generators [Formula: see text], Frobenius number [Formula: see text], multiplicity [Formula: see text] and genus [Formula: see text]. In this paper, we prove that Wilfs conjecture i.e. the inequality [Formula: see text] holds for [Formula: see text] when [Formula: see text] is a basis for [Formula: see text]