bluuebunny/crossref_metadata_2025 huggingface dataset:
Effectiveness of non-opioid pharmacological adjuncts for adult surgical patients: an umbrella review protocol
Authors: Husser Travis , Marcom Jason , Mark Jordan , Buonora John , Benham Brian
Published: March 2019

Objective:

The objective of this review is to determine the effectiveness of non-opioid pharmacological adjuncts for decreasing perioperative morphine equivalents and acute postoperative pain scores in adult surgical patients.

Introduction:

Opioids are commonly administered during anesthesia to dull the senses, relieve pain and induce sleep. However, there are significant adverse effects associated with intraoperative opioid use. Anesthesia providers can impact the current opioid epidemic by administering non-opioid-centric anesthetic medications. A large-scale evidence-based review is needed to inform a standardized non-opioid pain treatment strategy in the perioperative period.

Inclusion criteria:

This review will consider studies of adults 19 years or older who are undergoing surgical procedures and receiving non-opioid oral or intravenous perioperative analgesic medications administered by the anesthesia team. Studies that include patients who receive non-opioid medication as a local infiltrate by the surgical team will be excluded, as will studies with patients who receive regional or neuraxial opioid-sparing techniques. Only systematic reviews and meta-analyses published in English after 2007 will be considered.

Methods:

MEDLINE, CINAHL and Embase will be searched, as well as two trial registers and two sources of unpublished reviews. Titles and abstracts will be screened to identify potentially relevant papers. Retrieval of full-text studies, assessment of methodological quality and data extraction will be performed independently by two reviewers. Meta-analyses will be performed if possible, and a Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Summary of Findings presented.

Systematic review registration number:

PROSPERO CRD42019135852
Effectiveness and safety of perioperative enteral feeding in patients with burn injuries: a systematic review protocol
Authors: Cork Michelle , McArthur Alexa , Douglas Helen , Wood Fiona
Published: March 2019

Objective:

The objective of this review is to determine whether perioperative enteral feeding improves outcomes in patients with burns.

Introduction:

Literature has identified many positive benefits of nutrition support for patients with burn injuries, including preservation of lean body mass, improved wound healing, reduced gastrointestinal permeability and enhanced immunity. Fasting for surgery can undermine the nutritional care of these patients by causing nutrient deficits. It may also negatively affect patient well-being and insulin resistance. Perioperative fasting is intended to protect patients from regurgitation and pulmonary aspiration. This research aims to investigate whether perioperative feeding impacts outcomes in patients with burn injuries.

Inclusion criteria:

This systematic review will consider studies whose participants have a burn injury. The intervention is perioperative enteral feeding (either intragastric or post-pyloric). Patients who received perioperative feeding will be compared with patients who had enteral nutrition withheld during the perioperative period. A number of outcome measures will be investigated, including mortality, length of stay, wound infection, wound healing rate and aspiration pneumonia.

Methods:

The key databases searched will be PubMed, CINAHL, Embase, Web of Science and Cochrane Central Register of Controlled Trials and Scopus. Only studies published in English will be considered. There will be no date limits. Full texts of selected studies will be retrieved and assessed against inclusion criteria. Studies that do not meet the inclusion criteria will be excluded, with reasons provided. Data synthesis will be pooled in a statistical meta-analysis. Subgroup analysis will be conducted where possible. Where statistical pooling is not possible, the findings will be presented in narrative form.

Systematic review registration number:

PROSPERO CRD42018119034
Reduced computational modelling of Kölliker‐Fuse contributions to breathing patterns in Rett syndrome
Authors: Wittman Samuel , Abdala Ana Paula , Rubin Jonathan E.
Published: March 2019

Key points

Reduced computational models are used to test effects of loss of inhibition to the Kölliker‐Fuse nucleus (KFn).

Three reduced computational models that simulate eupnoeic and vagotomized respiratory rhythms are considered.

All models exhibit the emergence of respiratory perturbations associated with Rett syndrome as inhibition to the KFn is diminished.

Simulations suggest that application of 5‐HT1A agonists can mitigate the respiratory pathology.

The three models can be distinguished and tested based on their predictions about connections and dynamics within the respiratory circuit and about effects of perturbations on certain respiratory neuron populations.

Rett syndrome (RTT) is a developmental disorder that can lead to respiratory disturbances featuring prolonged apnoeas of variable durations. Determining the mechanisms underlying these effects at the level of respiratory neural circuits would have significant implications for treatment efforts and would also enhance our understanding of respiratory rhythm generation and control. While experimental studies have suggested possible factors contributing to the respiratory patterns of RTT, we take a novel computational approach to the investigation of RTT, which allows for direct manipulation of selected system parameters and testing of specific hypotheses. Specifically, we present three reduced computational models, developed using an established framework, all of which successfully simulate respiratory outputs across eupnoeic and vagotomized conditions. All three models show that loss of inhibition to the Kölliker‐Fuse nucleus reproduces the key respiratory alterations associated with RTT and, as suggested experimentally, that effects of 5‐HT1A agonists on the respiratory neural circuit suffice to alleviate this respiratory pathology. Each of the models makes distinct predictions regarding the neuronal populations and interactions underlying these effects, suggesting natural directions for future experimental testing.
Weight-Free Multi-Objective Predictive Cruise Control of Autonomous Vehicles in Integrated Perturbation Analysis and Sequential Quadratic Programming Optimization Framework
Authors: He Defeng , Shi Yujie , Song Xiulan
Published: March 2019

Adaptive cruise control of autonomous vehicles can be posed as a multi-objective optimization problem where several conflicting criteria, e.g., fuel economy, tracking capability, ride comfort, and safety, need to be satisfied simultaneously. In order to reconcile these conflicting criteria, this paper presents a novel multi-objective predictive cruise control (MOPCC) approach in the feasible perturbation-based real-time iterative optimization framework. The longitudinal dynamics of vehicles are described as nonlinear car-tracking models. The new cost function for MOPCC is defined as the distance of the criteria vector to the vector of separately minimized criteria (i.e., a utopia point of the criteria). The weight-free MOPCC is then obtained by solving a constrained nonlinear optimal control problem in receding horizon fashion. Due to the difficulty in solving the optimization problem, the integrated perturbation analysis and sequential quadratic programming (InPA-SQP) is employed to compute the cruise controller. The merit of the proposed MOPCC is that it can systematically handle different cruise scenarios regardless of the weights of the predictive cruise control (PCC) criteria. Several driving cases are used to demonstrate the effectiveness and benefits of the proposed approach via comparing to weighted PCC approaches.
A Real-Time Stability Indicator for Micromilling: An Experimental Validation
Authors: Kushwaha Shashwat , Gorissen Benjamin , Qian Jun , Reynaerts Dominiek
Published: March 2019

In contrast to the well-established stability prediction tools, a robust real-time stability indicator is proposed for micromilling process, and it opens the possibility of online chatter avoidance based on successful detection. In this paper, a robust and easy-to-compute stability indicator is presented. This approach exploits the virtue of a stable milling process—the displacement of the vibrating tool repeats with a period of tooth passing. It has been observed that the standard deviation of the tool displacement sampled at once per tooth passing frequency is indicative of chatter, where a low standard deviation coincides with stable cutting. An increase in standard deviation is the direct consequence of an increase in asynchronous motion of the tool, coinciding with chatter. As it is also well known, this asynchronous vibration of the tool results in distinct marks on the workpiece surface. This paper presents the experimental validation of this real-time stability indicator. The ease of implementation makes the presented stability indicator a strong candidate for applications in chatter avoidance based on detection. The results are also verified against the standard stability prediction method.
Multi-channel adaptive dereverberation robust to abrupt change of target speaker position
Authors: Xiang Teng , Lu Jing , Chen Kai
Published: March 2019

Adaptive algorithm based on multi-channel linear prediction (MCLP) is an effective dereverberation method. However, the abrupt change of the target speech source position makes it difficult to guarantee both the fast convergence speed and the optimal steady-state behavior. In this letter, the recursive-least-squares (RLS)-based and Kalman-filter-based adaptive MCLP method for speech dereverberation are investigated. Based on the relative weighted change of the adaptive filter coefficients, a time-varying forgetting factor for the RLS algorithm and a re-initialization mechanism for the Kalman filter are proposed to make the algorithm robust to the abrupt change of the target speaker positions. The advantages of the proposed scheme are demonstrated in the experiments.
Comparison of effects on subjective intelligibility and quality of speech in babble for two algorithms: A deep recurrent neural network and spectral subtraction
Authors: Keshavarzi Mahmoud , Goehring Tobias , Turner Richard E. , Moore Brian C. J.
Published: March 2019

The effects on speech intelligibility and sound quality of two noise-reduction algorithms were compared: a deep recurrent neural network (RNN) and spectral subtraction (SS). The RNN was trained using sentences spoken by a large number of talkers with a variety of accents, presented in babble. Different talkers were used for testing. Participants with mild-to-moderate hearing loss were tested. Stimuli were given frequency-dependent linear amplification to compensate for the individual hearing losses. A paired-comparison procedure was used to compare all possible combinations of three conditions. The conditions were: speech in babble with no processing (NP) or processed using the RNN or SS. In each trial, the same sentence was played twice using two different conditions. The participants indicated which one was better and by how much in terms of speech intelligibility and (in separate blocks) sound quality. Processing using the RNN was significantly preferred over NP and over SS processing for both subjective intelligibility and sound quality, although the magnitude of the preferences was small. SS processing was not significantly preferred over NP for either subjective intelligibility or sound quality. Objective computational measures of speech intelligibility predicted better intelligibility for RNN than for SS or NP.
Influence of Plant Species, Tissue Type, and Temperature on the Capacity of Shiga-Toxigenic
Escherichia coli
To Colonize, Grow, and Be Internalized by Plants
Authors: Merget Bernhard , Forbes Ken J. , Brennan Fiona , McAteer Sean , Shepherd Tom , Strachan Norval J. C. , Holden Nicola J.
Published: March 2019

Fresh produce is an important vehicle for STEC transmission, and experimental evidence shows that STEC can colonize plants as secondary hosts, but differences in the capacity to colonize occur between different plant species and tissues. Therefore, an understanding of the impact that these plant factors have on the ability of STEC to grow and establish is required for food safety considerations and risk assessment. Here, we determined whether growth and the ability of STEC to form biofilms in plant extracts could be related to specific plant metabolites or could predict the ability of the bacteria to colonize living plants. Growth rates for sprouted seeds (alfalfa and fenugreek) but not those for leafy vegetables (lettuce and spinach) exhibited a positive relationship between plant extracts and living plants. Therefore, the detailed variations at the level of the bacterial isolate, plant species, and tissue type all need to be considered in risk assessment.
Biofilm-Constructing Variants of Paraburkholderia phytofirmans PsJN Outcompete the Wild-Type Form in Free-Living and Static Conditions but Not
In Planta
Authors: Rondeau Marine , Esmaeel Qassim , Crouzet Jérôme , Blin Pauline , Gosselin Isabelle , Sarazin Catherine , Pernes Miguel , Beaugrand Johnny , Wisniewski-Dyé Florence , Vial Ludovic , Faure Denis , Clément Christophe , Ait Barka Essaïd , Jacquard Cédric , Sanchez Lisa
Published: March 2019

Paraburkholderia phytofirmans
strain PsJN is a well-studied plant-associated bacterium known to induce resistance against biotic and abiotic stresses. In this work, we described the spontaneous appearance of mucoid variants in PsJN from static cultures. We showed that the conversion from the wild-type (WT) form to variants (V) correlates with an overproduction of EPS, an enhanced ability to form biofilm
in vitro
and
in planta
, and a reduced swimming motility. Our results revealed also that these phenotypes are in part associated with spontaneous mutations in an iron-sulfur cluster. Overall, the data provided here allow a better understanding of the adaptive mechanisms likely developed by
P. phytofirmans
PsJN in a heterogeneous environment.
A Klebsiella pneumoniae Regulatory Mutant Has Reduced Capsule Expression but Retains Hypermucoviscosity
Authors: Walker Kimberly A. , Miner Taryn A. , Palacios Michelle , Trzilova Dominika , Frederick Daniel R. , Broberg Christopher A. , Sepúlveda Victoria E. , Quinn Joshua D. , Miller Virginia L.
Published: March 2019

Klebsiella pneumoniae
continues to be a substantial public health threat due to its ability to cause health care-associated and community-acquired infections combined with its ability to acquire antibiotic resistance. Novel therapeutics are needed to combat this pathogen, and a greater understanding of its virulence factors is required for the development of new drugs. A key virulence factor for
K. pneumoniae
is the capsule, and community-acquired hypervirulent strains produce a capsule that causes hypermucoidy. We report here a novel capsule regulator, RmpC, and provide evidence that capsule production and the hypermucoviscosity phenotype are distinct processes. Infection studies showing that this and other capsule regulator mutants have a range of phenotypes indicate that additional virulence factors are in their regulons. These results shed new light on the mechanisms controlling capsule production and introduce targets that may prove useful for the development of novel therapeutics for the treatment of this increasingly problematic pathogen.
Mitogen-Activated Protein Kinase Cross-Talk Interaction Modulates the Production of Melanins in Aspergillus fumigatus
Authors: Manfiolli Adriana Oliveira , Siqueira Filipe Silva , dos Reis Thaila Fernanda , Van Dijck Patrick , Schrevens Sanne , Hoefgen Sandra , Föge Martin , Straßburger Maria , de Assis Leandro José , Heinekamp Thorsten , Rocha Marina Campos , Janevska Slavica , Brakhage Axel A. , Malavazi Iran , Goldman Gustavo H. , Valiante Vito
Published: March 2019

Aspergillus fumigatus
is the most important airborne human pathogenic fungus, causing thousands of deaths per year. Its lethality is due to late and often inaccurate diagnosis and the lack of efficient therapeutics. The failure of efficient prophylaxis and therapy is based on the ability of this pathogen to activate numerous salvage pathways that are capable of overcoming the different drug-derived stresses. A major role in the protection of
A. fumigatus
is played by melanins. Melanins are cell wall-associated macromolecules classified as virulence determinants. The understanding of the various signaling pathways acting in this organism can be used to elucidate the mechanism beyond melanin production and help to identify ideal drug targets.
Antibodies to Peptides in Semiconserved Domains of RIFINs and STEVORs Correlate with Malaria Exposure
Authors: Zhou Albert E. , Berry Andrea A. , Bailey Jason A. , Pike Andrew , Dara Antoine , Agrawal Sonia , Stucke Emily M. , Ouattara Amed , Coulibaly Drissa , Lyke Kirsten E. , Laurens Matthew B. , Adams Matthew , Takala-Harrison Shannon , Pablo Jozelyn , Jasinskas Algis , Nakajima Rie , Niangaly Amadou , Kouriba Bourema , Kone Abdoulaye K. , Rowe J. Alexandra , Doumbo Ogobara K. , Thera Mahamadou A. , Patel Jigar J. , Tan John C. , Felgner Philip L. , Plowe Christopher V. , Travassos Mark A.
Published: March 2019

Malaria, an infectious disease caused by the parasite
Plasmodium falciparum
, causes nearly 435,000 deaths annually worldwide. RIFINs and STEVORs are two variant surface antigen families that are involved in malaria pathogenesis and immune evasion. Recent work has shown that a lack of humoral immunity to these proteins is associated with severe malaria vulnerability in Malian children. This is the first study to have compared serologic responses of children and adults to RIFINs and STEVORs in settings of malaria endemicity and to examine such serologic responses before and after a clinical malaria episode. Using microarrays, we determined that the semiconserved domains in these two parasite variant surface antigen families harbor peptides whose seroreactivity reflects malaria exposure. A similar approach has the potential to illuminate the role of variant surface antigens in the development of natural immunity to clinical malaria. Potential vaccines for severe malaria should include consideration of peptides within the semiconserved domains of RIFINs and STEVORs.
Age-related gait standards for healthy children and young people: the GOS-ICH paediatric gait centiles
Authors: Alderson Lucy M. , Joksaite Sandra X , Kemp Jennifer , Main Eleanor , Watson Tim , Platt Frances M , Cortina-Borja Mario
Published: March 2019

Objective

To develop paediatric gait standards in healthy children and young people.

Methods

This observational study aims to address the lack of population standards for gait measurements in children. Analysing gait in children affected by neurological or musculoskeletal conditions is an important component of paediatric assessment but is often confounded by developmental changes. The standards presented here do not require clinician expertise to interpret and offer an alternative to developmental tables of normalised gait data. Healthy children aged 1–19 years were recruited from community settings in London and Hertfordshire, UK. The GAITRite walkway was used to record measurements for each child for velocity, cadence, step length, base of support and stance, single and double support (as percentage of gait cycle). We fitted generalised linear additive models for location, scale and shape (gamlss).

Results

We constructed percentile charts for seven gait variables measured on 624 (321 males) contemporary healthy children using a gamlss package in R. A clinical application of gait standards was explored.

Conclusion

Age-related, gender-specific standards for seven gait variables were developed and are presented here. They have a familiar format and can be used clinically to aid diagnoses and to monitor change over time for both medical therapy and natural history of the condition. The clinical example demonstrates the potential of the Great Ormond Street Institute of Child Health Paediatric Gait Centiles to enable meaningful interpretation of change in an individual’s performance and describes characteristic features of gait from a specific population throughout childhood.
Exogenous influences on intraocular pressure
Authors: Kim Yong Woo , Park Ki Ho
Published: March 2019

Intraocular pressure (IOP), the pressure within the eyeball, is a function mainly of the production and elimination of aqueous humour. Balanced IOP helps to maintain the eyeball contour, allowing proper refraction of light in the anterior segment of the eye. Increases in IOP can cause injury to the ocular structure, typically the optic nerve head and retinal ganglion cells. IOP increase, additionally, is a risk factor for glaucoma progression. However, it is not unusual that glaucoma worsens despite well-managed IOP; indeed, glaucoma can develop and progress even within the normal IOP range. IOP measured once during daytime office hours might not provide sufficient information for effective glaucoma management. In fact, IOP is not a fixed value but rather changes over time: it fluctuates with the intrinsic circadian rhythm and can also change in various lifestyle-related situations (eg, with body posture, during exercise, while holding breath and according to dietary habits). It is therefore worth exploring the various factors that can affect IOP and glaucoma risk. In this review, the various exogenous influences on IOP in the literature are investigated.
Release of silicone oil and the off-label use of syringes in ophthalmology
Authors: Melo Gustavo Barreto , Emerson Geoffrey Guy , Dias Jr Celso Souza , Morais Fábio Barreto , Lima Filho Acacio de Souza , Ota Shoko , Farah Michel Eid , Rodrigues Eduardo Büchele , Maia Maurício , Belfort Jr Rubens
Published: March 2019

Background/aims

To assess silicone oil (SO) release by different brands of syringes used for intravitreal injection under different handling conditions.

Methods

Eight syringes were analysed: from the USA, Terumo 0.5 mL, Becton-Dickinson (BD) Tuberculin 1 mL, BD Luer-lok 1 mL, BD Ultra-Fine 0.3 mL and Exel Insulin 0.3 mL; from Germany, Braun Omnifix-F 1 mL and Braun Injekt-F 1 mL and from Spain, BD Plastipak 1 mL. The impact of air, priming the plunger, agitation by flicking and fluid temperature on SO release were assessed by light microscopy. Fourier transform infrared spectroscopy (FTIR) was performed to identify the molecular compound in each syringe.

Results

Five hundred and sixty syringes were analysed. Terumo 0.5 mL and BD Ultra-Fine 0.3 mL released more SO than all others. BD Luer-lok 1 mL, BD Plastipak and Braun Omnifix-F 1 mL released little SO; BD Tuberculin 1 mL, Exel 0.3 mL and Braun Injekt-F 1 mL released the least SO. Priming the syringe and different temperatures did not significantly affect SO release. Agitation by flicking caused a significantly higher proportion of samples to have SO droplets and an increased number of oil droplets. Air had an additive effect on the release of oil in the agitation groups. FTIR identified polysiloxane in all syringes but Injekt-F.

Conclusion

Syringes commonly used for intravitreal injections frequently release SO droplets, especially when agitated by flicking. To avoid unnecessary ocular risks, syringes should not be agitated before intravitreal injection. It is desirable that syringes be manufactured specifically for ophthalmic use.
Prevalence and progression of aortic root dilatation in highly trained young athletes
Authors: Gati Sabiha , Malhotra Aneil , Sedgwick Catherine , Papamichael Nikolaos , Dhutia Harshil , Sharma Rajan , Child Anne H , Papadakis Michael , Sharma Sanjay
Published: March 2019

Objectives

Aortic root dilatation is reported in young athletes; however, it is unclear whether such remodelling is physiological or, whether it represents a potential aortopathy. This observational study investigated the prevalence and progression of aortic root dilatation in young athletes competing at regional or national level.

Methods

Between 2003 and 2015, 3781 athletes aged 19±5.9 years (63.3% male) underwent echocardiography as part of a cardiac screening programme to identify athletes with structural abnormalities. Athletes trained for an average of 16.7 hours per week. Aortic diameter was measured at the level of sinuses of Valsalva. Results were compared with 806 controls. Athletes with an enlarged aortic diameter were followed up for 5±1.5 years.

Results

Athletes revealed a larger mean aortic diameter compared with controls (28.3±4.1 vs 27.8±4.1 mm; p=0.01). The 99th percentile value for aortic diameter in the athlete cohort was defined as the upper limit and was 40 mm in males and 38 mm in females. The aortic diameter measured >40 mm in five male (0.17%) (40–43 mm) and >38 mm in six female (0.4%) (39–41 mm) athletes. During follow-up, none of the athletes with an enlarged aortic diameter showed progressive aortic enlargement compared with the first assessment (40.6±0.9 vs 40.5±0.7 mm in males; (p=0.111) and 38.3±0.6 vs 38.0±0.7 mm in females; (p=0.275)).

Conclusions

A small minority (0.3%) of athletes reveal an enlarged aortic diameter. Medium-term follow-up does not reveal progressive enlargement of the aortic diameter indicative of aortopathy. Longer surveillance studies are necessary to elucidate the precise significance of an enlarged aortic diameter in athletes.
Anti-adipogenesis and antioxidative defense status of a crude extract of ‘Kalasin 2’ peanut sprouts in 3T3-L1 mouse adipocytes
Authors: Boonsong Tantip , Pakwan Siriporn , Chawnawa Wanida
Published: March 2019

The aim of this study was to investigate the effects of extracts from germinated (GPE) and non-germinated peanuts (NGPE) on adipogenesis and oxidative status in normal and oxidative-stress-induced 3T3-L1 mouse adipocytes. The treated cells were analysed for cell growth, lipid accumulation, levels of intracellular reactive oxygen species (ROS), and the expression levels of mRNAs and proteins related to adipogenesis and antioxidative defense systems. The results indicated that an extract from peanuts made 9 days after germination (9GPE) reduced lipid contents and mRNA expression of adipogenesis-related genes to a greater extent than an extract from peanuts made 1-day after germination (1GPE) or from NGPE, respectively. In oxidative-stress-induced adipocytes, 9GPE decreased ROS levels, lipid content, and the protein expression of peroxisome-proliferator-activated receptor gamma, and also increased the protein expression of antioxidants. These results illustrate the anti-adipogenic capacity and oxidative status improvement achievable with GPE, and that it could be used as a putative therapeutic agent in the prevention of and (or) treatment of obesity and diseases associated with oxidative stress.
Reproducing micro X-ray computed tomography (microXCT) observations of air–water distribution in porous media using revised pore-morphology method
Authors: Liu Xin , Zhou Annan , Li Jie , Feng Shijin
Published: March 2019

This study presents a novel and simple morphology approach to generate two-dimensional air–water distribution in porous media considering Or and Tuller’s cavitation mechanism (published in 2002). The connectedness condition for the nonwetting phase is replaced by the Laplace equation. An algorithm is developed to detect the ruptured water spaces that are incorrectly formed in the throat by the morphology approach, but cannot exist in a real thermodynamic equilibrium system. The distributions of soil moisture, water retention curve, and air–liquid interface area at different saturations predicted by this method are in a good quantitative agreement with the experimental observations on glass beads and Ottawa sand from micro X-raycomputed tomography (microXCT). Compared to Lu et al.’s Monte Carlo lattice-gas approach (published in 2010), another computational method to generate the soil moisture distribution, the proposed approach provides better results with significantly less computational power.
Unsteady free convective heat transfer in third-grade fluid flow from an isothermal vertical plate: A thermodynamic analysis
Authors: Hiremath Ashwini , Reddy G. Janardhana , Kumar Mahesh , Bég O. Anwar
Published: March 2019

The current study investigates theoretically and numerically the entropy generation in time-dependent free-convective third-grade viscoelastic fluid convection flow from a vertical plate. The nondimensional conservation equations for mass, momentum and energy are solved using a Crank–Nicolson finite difference method with suitable boundary conditions. Expressions for known values of flow-variables coefficients are also derived for the wall heat transfer and skin friction and numerically evaluated. The effect of Grashof number, Prandtl number, group parameter (product of dimensionless temperature difference and Brinkman number) and third-grade parameter on entropy heat generation is analyzed and shown graphically. Bejan line distributions are also presented for the influence of several control parameters. The computations reveal that with increasing third-grade parameter, the entropy generation decreases and Bejan number increases. Also, the comparison graph shows that contour lines for third-grade fluid vary considerably from the Newtonian fluid. The study is relevant to non-Newtonian thermal materials processing systems.
COMPRESSIVE STRENGTH OF FRACTAL-TEXTURED FOAMED CONCRETE
Authors: CHEN Y. , XU Y. F.
Published: March 2019

Foamed concrete possesses characteristics such as high strength-to-weight ratio and low density, and widely used to reduce dead loads on the structure and foundation, contributes to energy conservation, and lowers the labor cost during construction. In this paper, the objective is to propose prediction relation for the compressive strength of foamed concrete by fractal theory. A theoretical relation was derived for the compressive strength relating to porosity based on the fractal model for foamed concrete. The proposed relation stands out compared to empirical model since it employs easily measurable parameter, the fractal dimension of porous structure in foamed concrete. The fractal dimension of porous structure can be calculated from the scaling law of the compressive strength of foamed concrete. The fractal model for porous structure serves as a simple and effective tool for predicting the compressive strength of foamed concrete because of its ease in application. The prediction relation of the compressive strength developed in this paper is found to match well with the measured strength.
EXACT TRAVELING-WAVE SOLUTIONS FOR ONE-DIMENSIONAL MODIFIED KORTEWEG–DE VRIES EQUATION DEFINED ON CANTOR SETS
Authors: GAO FENG , YANG XIAO-JUN , JU YANG
Published: March 2019

The one-dimensional modified Korteweg–de Vries equation defined on a Cantor set involving the local fractional derivative is investigated in this paper. With the aid of the fractal traveling-wave transformation technology, the nondifferentiable traveling-wave solutions for the problem are discussed in detail. The obtained results are accurate and efficient for describing the fractal water wave in mathematical physics.
A UNIFIED FRACTAL MODEL FOR PERMEABILITY COEFFICIENT OF UNSATURATED SOIL
Authors: TAO GAOLIANG , WU XIAOKANG , XIAO HENGLIN , CHEN QINGSHENG , CAI JIANCHAO
Published: March 2019

Due to the significant challenges in the measurements, evaluation of permeability coefficient for unsaturated soil is of immense importance for investigating the seepage and hydro-mechanical coupling problems of unsaturated soil. However, the predictions of existing typical models reveal significance divergence for permeability coefficient of unsaturated soils even under identical conditions. In particular, the existing models are greatly restricted in their practical application due to their complexity in the form of integral expressions that require significant computational effort. Here, a simplified unified model is presented to estimate the relative permeability coefficient. First, a fractal-form of soil–water characteristic curve (SWCC) is derived from fractal theory. Then, on the basis of the proposed SWCC models, the classical models (i.e. Childs and Collis-George (CCG) model, Burdine model, Mualem model and Tao and Kong model, respectively) for evaluating the permeability coefficient of unsaturated soil are converted to be presented in fractal forms. It is interestingly found that the fractal forms of these models are enormously similar. Based on these observations, a simplified unified fractal model for the relative permeability coefficient of unsaturated soil is proposed, where only two parameters (i.e. fractal dimension and air-entry value) are included, thereby significantly reducing the computational efforts. The detailed procedure for determining model parameters is elaborated. The accuracy of this model is verified by comparing its predictions with the experimental data for over 12 types of unsaturated soils. The results highlight that, compared with existing models, the proposed model would be much more efficiently used for estimating the relative permeability coefficient of unsaturated soils, thereby facilitating its application for investigating the associated seepage and hydro-mechanical coupling problems in practice.
FRACTAL CHARACTERISTICS OF NANOSCALE PORES IN SHALE AND ITS IMPLICATIONS ON METHANE ADSORPTION CAPACITY
Authors: LIU YU , ZHU YANMING , WANG YANG , CHEN SHANGBIN
Published: March 2019

Pore structure in shale controls the gas storage mechanism and gas transport behaviors. Since nanoscale pores in shale matrix have fractal characteristics, fractal theory can be used to study its structure. In addition, fractal method has its own advantages to investigate nanopores in shale, especially for the heterogeneity and irregularity of nanopores in shale. In this work, fractal features of nanoscale pores and the implication on methane adsorption capacity of shale were investigated by employing low pressure nitrogen adsorption, scanning electron microscopy (SEM), and methane adsorption experiments. Frenkel–Halsey–Hill (FHH) model was also used to calculate the fractal parameters of nanoscale pores in shale. The results showed that nanoscale pores in 12 shale samples have obvious fractal features. All the fractal curves of these shale samples can be divided into two segments, which are cut off by [Formula: see text], and the fractal dimensions of these two segments vary from 2.48 to 2.92 [Formula: see text] and 2.42 to 2.80 [Formula: see text], respectively. Based on SEM images, it is found that self-similarity of organic pore systems in shales refers to two aspects. One is that relatively large-scale and small-scale pores have similar formation properties and types, which are of elliptical shape with rough surface. The other is that some small-scale pores are formed by rough surface of relatively large pores. The results also demonstrate that methane adsorption capacity of shale samples increase with increasing total organic carbon (TOC) contents. This is mainly because organic matter is rich in pores and has relatively large fractal dimension values. Larger fractal dimensions indicate rougher pore surfaces and could form more small-scale organic pores. These organic pores would provide more space for methane adsorption.
A NUMERICAL STUDY ON THE UNDERWATER APPARENT CONTACT ANGLE OF OIL DROPLETS ON MICROSTRUCTURE SURFACE
Authors: CHOE HYONCHOL , KIM SONGHAK , O CHOLHUAN , ZONG JISONG , SONG WONCHOL
Published: March 2019

In this study, the apparent contact angles of oil droplets on the rough surfaces in water were numerically studied using the Volume of Fluid (VOF) model. The results showed that the roughness of the surface affected the wettability. By increasing the roughness of the surface, the oleophilicity of the oleophilic surface and the oleophobicity of the oleophobic surface could be increased. Furthermore, the applicability and limitations of the prediction of the underwater apparent contact angle of the oil droplet by the contact angle model were investigated by 3D numerical simulations. It suggests that Wenzel model can accurately predict the underwater apparent contact angle of oil droplets on all the oleophilic, neutral and oleophobic surfaces, and Cassie model can only be applied to the oleophobic surface and Cassie–Baxter model can only be applied to the oleophilic surface.
Cournot Equilibrium Uniqueness: At 0 Discontinuous Industry Revenue and Decreasing Price Flexibility
Authors: Von Mouche Pierre , Sato Takashi
Published: March 2019

We consider the equilibrium uniqueness problem for a large class of Cournot oligopolies with convex cost functions and a proper price function [Formula: see text] with decreasing price flexibility. This class allows for (at [Formula: see text]) discontinuous industry revenue and in particular for [Formula: see text]. The paper illustrates in an exemplary way the Selten–Szidarovszky technique based on virtual backward reply functions. An algorithm for the calculation of the unique equilibrium is provided.
Curvature properties of anisotropic scale invariant metrics
Authors: Shaikh Absos Ali , Srivastava Sudhir Kumar , Chakraborty Dhyanesh
Published: March 2019

The objective of this paper is to study the curvature restricted geometric properties of anisotropic nonrelativistic scale invariant metrics, namely, Lifshitz and Schrödinger spacetime metrics. It is found that the Lifshitz spacetime metric admits two important pseudosymmetric type curvature conditions [Formula: see text] and [Formula: see text]. Also, it is [Formula: see text]-quasi Einstein and generalized Roter type manifold. Finally, Lifshitz spacetime is compared with Schrödinger spacetime.
Almost-automorphisms of trees, cloning systems and finiteness properties
Authors: Skipper Rachel , Zaremsky Matthew C. B.
Published: March 2019

We prove that the group of almost-automorphisms of the infinite rooted regular [Formula: see text]-ary tree [Formula: see text] arises naturally as the Thompson-like group of a so-called [Formula: see text]-ary cloning system. A similar phenomenon occurs for any Röver–Nekrashevych group [Formula: see text], for [Formula: see text] a self-similar group. We use this framework to expand on work of Belk and Matucci, who proved that the Röver group, using the Grigorchuk group for [Formula: see text], is of type [Formula: see text]. Namely, we find some natural conditions on subgroups of [Formula: see text] to ensure that [Formula: see text] is of type [Formula: see text] and, in particular, we prove this for all [Formula: see text] in the infinite family of Šunić groups. We also prove that if [Formula: see text] is itself of type [Formula: see text], then so is [Formula: see text], and that every finitely generated virtually free group is self-similar, so in particular every finitely generated virtually free group [Formula: see text] yields a type [Formula: see text] Röver–Nekrashevych group [Formula: see text].
Group approximation in Cayley topology and coarse geometry Part I: Coarse embeddings of amenable groups
Authors: Mimura Masato , Sako Hiroki
Published: March 2019

The objective of this series is to study metric geometric properties of (coarse) disjoint unions of amenable Cayley graphs. We employ the Cayley topology and observe connections between large scale structure of metric spaces and group properties of Cayley accumulation points. In Part I, we prove that a disjoint union has property A of Yu if and only if all groups appearing as Cayley accumulation points in the space of marked groups are amenable. As an application, we construct two disjoint unions of finite special linear groups (and unimodular linear groups) with respect to two systems of generators that look similar such that one has property A and the other does not admit (fibered) coarse embeddings into any Banach space with nontrivial type (for instance, any uniformly convex Banach space).
Spectroscopic analysis and temperature-dependent dielectric properties of bulk Ni–Zn ceramics
Authors: Yadav Anand , Choudhary Pankaj , Saxena P. , Rai V. N. , Mishra A.
Published: March 2019

In the present work, series of Zn ion-doped Ni[Formula: see text]ZnxFe2O4([Formula: see text]) ceramics were prepared by the double sintered solid-state reaction route to find out the influence of Zn[Formula: see text] ions on the crystal structure, lattice structure and dielectric behavior of parent NiFe2O4. X-ray diffraction (XRD) study favors that all the prepared compounds belong to the cubic spinel structure. Lattice parameters found to have increasing value with increased Zn[Formula: see text] ion substitution. The Raman scattering measurement discerns optical-active modes with blue shift as the doping increases. The dielectric constant ([Formula: see text] and dielectric tangent loss (tan [Formula: see text] decrease with an increase in frequency and at higher frequency, both become constant. Dielectric parameters observe nonlinear behavior with increasing Zn[Formula: see text] ion substitution. Room temperature dielectric constant of 10% Zn ion-doped NiFe2O4[Ni[Formula: see text]Zn[Formula: see text]Fe2O4] is much higher as compared to other prepared ceramics. The room temperature ac conductivity is found to increase with increase in frequency and temperature-dependent ac conductivity increases with increase in temperature.
CEO Turnover, Information Uncertainty, and Debt Contracting
Authors: Deng Saiying , Intintoli Vincent J. , Zhang Andrew
Published: March 2019

CEO turnovers are important corporate events that can lead to significant changes within the firm. We find that CEO departures are associated with a subsequent increase in bank loan financing. The negative effect that CEO departures have on borrowing costs is largely driven by forced CEO turnovers. Following such departures, firms pay higher loan spreads, see an increase in covenants, and are more likely to be subject to collateral requirements, when compared to matched non-turnover and voluntary turnover firms. Evidence suggests that asset substitution and changes in accounting information quality help to explain the observed worsened terms following forced dismissals. On the other hand, more traditional voluntary departures are unrelated to changes in price and non-price loan terms.
Fluctuations for differences of linear eigenvalue statistics for sample covariance matrices
Authors: Cipolloni Giorgio , Erdős László
Published: March 2019

We prove a central limit theorem for the difference of linear eigenvalue statistics of a sample covariance matrix [Formula: see text] and its minor [Formula: see text]. We find that the fluctuation of this difference is much smaller than those of the individual linear statistics, as a consequence of the strong correlation between the eigenvalues of [Formula: see text] and [Formula: see text]. Our result identifies the fluctuation of the spatial derivative of the approximate Gaussian field in the recent paper by Dumitru and Paquette. Unlike in a similar result for Wigner matrices, for sample covariance matrices, the fluctuation may entirely vanish.
Role of Water for Life
Authors: Nordén Bengt
Published: March 2019

The behavior of benzoic acid in polyethylene inspired me to reflect on why water is a unique molecule that all living organisms depend upon. From properties of DNA in aqueous solution a seemingly counter-intuitive conjecture emerges: water is needed for the creation of certain dry low-dielectric nm-size environments where hydrogen bonding exerts strong recognition power. Such environments seem to be functionally crucial, and their interactions with other hydrophobic environments, or with hydrophobic agents that modulate the chemical potential of water, can cause structural transformations via ‘hydrophobic catalysis’. Possibly combined with an excluded volume osmosis effect (EVO), hydrophobic catalysis may have important biological roles, e.g., in genetic recombination. Hydrophobic agents are found to strongly accelerate spontaneous DNA strand exchange as well as certain other DNA rearrangement reactions. It is hypothesized that hydrophobic catalysis be involved in gene recognition and gene recombination mediated by bacterial RecA (one of the oldest proteins we know of) as well as in sexual recombination in higher organisms, by Rad51. Hydrophobically catalyzed unstacking fluctuations of DNA bases can favor elongated conformations, such as the recently proposed [Formula: see text]-DNA, with potential regulatory roles. That living cells can survive as dormant spores, with very low water content and in principle as such travel far in space is reflected upon: a random walk model with solar photon pressure as driving force indicates our life on earth could not have originated outside our galaxy but possibly from many solar systems within it — at some place, though, where there was plenty of liquid water.
Microbiological Safety of Dried Spices
Authors: Gurtler Joshua B. , Keller Susanne E.
Published: March 2019

Spices in the desiccated state provide an environment that allows the survival of many foodborne pathogens. Currently, the incidence of pathogen-positive spices imported into the United States is 1.9 times higher than for any other imported food. Correspondingly, imported spices have been associated with numerous foodborne outbreaks and multiple product recalls. Despite the association with recalls and outbreaks, the actual pathogen populations in spices, when found, are frequently extremely small. In addition to pathogenic bacterial species, toxigenic molds have been frequently recovered from spices, and aflatoxins have been found in as many as 58% of the spices sampled. The presence of toxigenic molds is especially problematic to the immunocompromised or those on immunosuppressive therapy and has been linked to gut aspergillosis. Numerous detection methods, including both traditional and advanced DNA regimes, are being tested to optimize recovery of pathogens from spices. Further, a number of new inactivation intervention methods to decontaminate spices are examined and discussed.
Emulsion Formation by Homogenization: Current Understanding and Future Perspectives
Authors: Håkansson Andreas
Published: March 2019

Emulsion formation by homogenization is commonly used in food production and research to increase product stability and to design colloidal structures. High-energy methods such as high-pressure homogenizers and rotor–stator mixers are the two most common techniques. However, to what extent does the research community understand the emulsion formation taking place in these devices? This contribution attempts to answer this question through critically reviewing the scientific literature, starting with the hydrodynamics of homogenizers and continuing by reviewing drop breakup and coalescence. It is concluded that although research in this field has been ongoing for a century and has provided a substantial amount of empirical correlations and scaling laws, the fundamental understanding is still limited, especially in the case of emulsions with a high-volume fraction of the disperse phase, as seen in many food applications. These limitations in the current understanding are also used to provide future perspectives and suggest directions for further investigation.
Recent Advances in the Application of Metabolomics for Nutrition and Health
Authors: González-Peña Diana , Brennan Lorraine
Published: March 2019

Metabolomics is the study of small molecules called metabolites in biological samples. Application of metabolomics to nutrition research has expanded in recent years, with emerging literature supporting multiple applications. Key examples include applications of metabolomics in the identification and development of objective biomarkers of dietary intake, in developing personalized nutrition strategies, and in large-scale epidemiology studies to understand the link between diet and health. In this review, we provide an overview of the current applications and identify key challenges that need to be addressed for the further development of the field. Successful development of metabolomics for nutrition research has the potential to improve dietary assessment, help deliver personalized nutrition, and enhance our understanding of the link between diet and health.