bluuebunny/crossref_metadata_2025 huggingface dataset:
Comment on “Diffusion by a random velocity field” [Phys. Fluids 13, 22 (1970)]
Authors: Saad Tony , Sutherland James C.
Published: November 2016

This comment aims at addressing a mass conservation issue in a paper published in the physics of fluids. The paper [R. H. Kraichnan, “Diffusion by a random velocity field,” Phys. Fluids 13(1), 22 (1970)] introduces a novel method to generate synthetic isotropic turbulence for computational purposes. The method has been used in the literature to generate inlet boundary conditions and to model aeroacoustic noise as well as for validation and verification purposes. However, the technique uses a continuous formulation to derive the mass conservation constraint. In this comment, we argue that the continuous constraint is invalid on a discrete grid and provide an alternative derivation using the discrete divergence. In addition, we present an analysis to quantify the impact of a pressure projection on the kinetic energy of a non-solenoidal velocity field.
Structural and thermoelectric properties of SiGe/Al multilayer systems during metal induced crystallization
Authors: Lindorf M. , Rohrmann H. , Span G. , Raoux S. , Jordan-Sweet J. , Albrecht M.
Published: November 2016

While the process of metal induced crystallization (MIC) is widely used in the fabrication of thin film electronic devices, its application to the field of thermoelectrics is fairly new. Especially, its implementation in the field of the classic thermoelectric material SiGe could lead to a low cost approach by combining the benefits of low thermal budget, self-doping, and thin film and sputter deposition compatibility. In this work, samples consisting of SiGe/Al multilayers deposited on aluminum oxide based substrates have been prepared. Special emphasis was put on the ratio of Al to SiGe and the resulting changes in transport properties during annealing. On one hand, a certain amount of Al is needed to ensure a complete MIC process for the SiGe, but on the other hand, an excess of Al results in a metallic system with low thermoelectric efficiency. In-situ characterization during annealing of the samples was carried out via x-ray diffraction, electrical resistivity, and Seebeck measurements.
Gate tunneling current and quantum capacitance in metal-oxide-semiconductor devices with graphene gate electrodes
Authors: An Yanbin , Shekhawat Aniruddh , Behnam Ashkan , Pop Eric , Ural Ant
Published: November 2016

Metal-oxide-semiconductor (MOS) devices with graphene as the metal gate electrode, silicon dioxide with thicknesses ranging from 5 to 20 nm as the dielectric, and p-type silicon as the semiconductor are fabricated and characterized. It is found that Fowler-Nordheim (F-N) tunneling dominates the gate tunneling current in these devices for oxide thicknesses of 10 nm and larger, whereas for devices with 5 nm oxide, direct tunneling starts to play a role in determining the total gate current. Furthermore, the temperature dependences of the F-N tunneling current for the 10 nm devices are characterized in the temperature range 77–300 K. The F-N coefficients and the effective tunneling barrier height are extracted as a function of temperature. It is found that the effective barrier height decreases with increasing temperature, which is in agreement with the results previously reported for conventional MOS devices with polysilicon or metal gate electrodes. In addition, high frequency capacitance-voltage measurements of these MOS devices are performed, which depict a local capacitance minimum under accumulation for thin oxides. By analyzing the data using numerical calculations based on the modified density of states of graphene in the presence of charged impurities, it is shown that this local minimum is due to the contribution of the quantum capacitance of graphene. Finally, the workfunction of the graphene gate electrode is extracted by determining the flat-band voltage as a function of oxide thickness. These results show that graphene is a promising candidate as the gate electrode in metal-oxide-semiconductor devices.
The thermodynamical instability induced by pressure ionization in fluid helium
Authors: Li Qiong , Liu Hai-Feng , Zhang Gong-Mu , Zhao Yan-Hong , Lu Guo , Tian Ming-Feng , Song Hai-Feng
Published: November 2016

A systematic study of pressure ionization is carried out in the chemical picture by the example of fluid helium. By comparing the variants of the chemical model, it is demonstrated that the behavior of pressure ionization depends on the construction of the free energy function. In the chemical model with the Coulomb free energy described by the Padé interpolation formula, thermodynamical instability induced by pressure ionization is found to be manifested by a discontinuous drop or a continuous fall and rise along the pressure-density curve as well as the pressure-temperature curve, which is very much like the first order liquid-liquid phase transition of fluid hydrogen from the first principles simulations. In contrast, in the variant chemical model with the Coulomb free energy term empirically weakened, no thermodynamical instability is induced when pressure ionization occurs, and the resulting equation of state achieves a good agreement with the first principles simulations of fluid helium.
Drop-on-demand inkjet-based cell printing with 30-μm nozzle diameter for cell-level accuracy
Authors: Kim Young Kwon , Park Ju An , Yoon Woong Hee , Kim Joonwon , Jung Sungjune
Published: November 2016

We present drop-on-demand inkjet-based mammalian cell printing with a 30-μm nozzle diameter for cell-level accuracy. High-speed imaging techniques have been used to analyze the go-and-stop movement of cells inside the nozzle under a pulsed pressure generated by a piezo-actuator and the jet formation after ejection. Patterning of an array of 20 × 20 dots on a glass substrate reveals that each printed drop contains 1.30 cells on average at the cell concentration of 5.0 × 106 cells ml−1 for the very small nozzle, whereas larger nozzles with the diameter of 50 and 80 μm deliver 2.57 and 2.88 cells per drop, respectively. The effects of the size and concentration of printed cells on the number of cells have also been investigated. Furthermore, the effect of the nozzle diameter on printed cells has been evaluated through an examination of viability, proliferation, and morphology of cells by using a live/dead assay kit, CCK-8 assay, and cellular morphology imaging, respectively. We believe that the 30-μm inkjet nozzle can be used for precise cell deposition without any damages to the printed mammalian cells.
A sub-1-volt analog metal oxide memristive-based synaptic device with large conductance change for energy-efficient spike-based computing systems
Authors: Hsieh Cheng-Chih , Roy Anupam , Chang Yao-Feng , Shahrjerdi Davood , Banerjee Sanjay K.
Published: November 2016

Nanoscale metal oxide memristors have potential in the development of brain-inspired computing systems that are scalable and efficient. In such systems, memristors represent the native electronic analogues of the biological synapses. In this work, we show cerium oxide based bilayer memristors that are forming-free, low-voltage (∼|0.8 V|), energy-efficient (full on/off switching at ∼8 pJ with 20 ns pulses, intermediate states switching at ∼fJ), and reliable. Furthermore, pulse measurements reveal the analog nature of the memristive device; that is, it can directly be programmed to intermediate resistance states. Leveraging this finding, we demonstrate spike-timing-dependent plasticity, a spike-based Hebbian learning rule. In those experiments, the memristor exhibits a marked change in the normalized synaptic strength (>30 times), when the pre- and post-synaptic neural spikes overlap. This demonstration is an important step towards the physical construction of high density and high connectivity neural networks.
A Derivation of the Gibbs Equation and the Determination of Change in Gibbs Entropy from Calorimetry
Authors: Evans Denis J. , Searles Debra J. , Williams Stephen R.
Published: November 2016

In this paper, we give a succinct derivation of the fundamental equation of classical equilibrium thermodynamics, namely the Gibbs equation. This derivation builds on our equilibrium relaxation theorem for systems in contact with a heat reservoir. We reinforce the comments made over a century ago, pointing out that Clausius’ strict inequality for a system of interest is within Clausius’ set of definitions, logically undefined. Using a specific definition of temperature that we have recently introduced and which is valid for both reversible and irreversible processes, we can define a property that we call the change in calorimetric entropy for these processes. We then demonstrate the instantaneous equivalence of the change in calorimetric entropy, which is defined using heat transfer and our definition of temperature, and the change in Gibbs entropy, which is defined in terms of the full N-particle phase space distribution function. The result shows that the change in Gibbs entropy can be expressed in terms of physical quantities.
Muscle fibre types in the reduced forelimb and enlarged hindlimb of the quokka (Setonix brachyurus, Macropodidae)
Authors: Casinos A. , Milne N. , Jouffroy F. K. , Médina M. F.
Published: November 2016

The quokka (Setonyx brachyurus) is restricted to two offshore islands and small isolates on the mainland of south-western Australia. It displays a tendency to saltatorial locomotion and moves at speed by bipedal hopping, although it also uses its forelimbs at low speed. Its bipedal adaptation involves enlarged hind limbs, with elongated feet. The fibre type distribution of the elbow and knee extensors, and the ankle plantar flexors, in comparison with two eutherians, the quadrupedal rhesus monkey, as a locomotor generalist, and the jerboa, a small eutherian hopping species morphologically similar to the quokka, were studied. The quokka’s forelimb showed the same characteristics as that of the jerboa, lacking the fatigue-resistant Type I fibres that are used to sustain posture. As in the jerboa, the gastrocnemius lateralis was the muscle head with the highest proportion of fast twitch fibres. Muscular fibre pattern is not identical in the quokka and the jerboa hindlimb, but it appears that both species have similar anatomical adaptations to saltatorial locomotion. Differences in muscle fibre proportions could be due to several factors including, resting posture, body size and the propensity for elastic energy storage, the burrowing behaviour of the jerboa, but also to phylogenetic constraints where the adaptation to hop on the hindlimbs is a shared behaviour of the Macropodoidea (jerboas are the only Dipodidae to have elongated hindlimbs).
Data-driven parameterization of the generalized Langevin equation
Authors: Lei Huan , Baker Nathan A. , Li Xiantao
Published: November 2016

Significance

The generalized Langevin equation (GLE) provides a precise description of coarse-grained variable dynamics in reduced dimension models. However, computation of the memory kernel poses a major challenge to the practical use of the GLE. This paper presents a data-driven approach to compute the memory kernel, relying on a hierarchy of parameterized rational approximations in terms of the Laplace transform, which can be expanded to arbitrarily high order as necessary. This parameterization makes it convenient to represent the GLE via an extended stochastic model where the memory term is eliminated by properly introducing auxiliary variables. The present method is well-suited for constructing reduced models for nonequilibrium properties of complex systems such as biomolecules, chemical reaction networks, and climate simulations.
Permissive roles of cytokines interleukin-7 and Flt3 ligand in mouse B-cell lineage commitment
Authors: von Muenchow Lilly , Alberti-Servera Llucia , Klein Fabian , Capoferri Giuseppina , Finke Daniela , Ceredig Rhodri , Rolink Antonius , Tsapogas Panagiotis
Published: November 2016

Significance

The generation of different blood lineages is regulated by hematopoietic cytokines, either in an instructive or in a permissive manner. The cytokines Interleukin-7 and fms-like tyrosine kinase-3 (Flt3) ligand are required for B-cell development but their precise mode of action remains controversial. Our study has addressed the role of these cytokines in B-cell commitment by analyzing the progenitor stage where B-cell commitment occurs in mice overexpressing one of the two cytokines in the absence of the other. Our results demonstrate a permissive role for both cytokines in B-cell commitment. Interleukin-7 promotes survival of progenitors instead of up-regulation of B-cell commitment factors early B-cell factor 1 (Ebf1) and paired box 5 (Pax5), as previously hypothesized, whereas Flt3 ligand facilitates progenitor expansion by inducing their proliferation.
Framework for making better predictions by directly estimating variables’ predictivity
Authors: Lo Adeline , Chernoff Herman , Zheng Tian , Lo Shaw-Hwa
Published: November 2016

Significance

Good prediction, especially in the context of big data, is important. Common approaches to prediction include using a significance-based criterion for evaluating variables to use in models and evaluating variables and models simultaneously for prediction using cross-validation or independent test data. The first approach can lead to choosing less-predictive variables, because significance does not imply predictivity. The second approach can be improved through considering a variable’s predictivity as a parameter to be estimated. The literature currently lacks measures that do this. We suggest a measure that evaluates variables’ abilities to predict, the

I

-score. The

I

-score is effective in differentiating between noisy and predictive variables in big data and can be related to a lower bound for the correct prediction rate.
Formation and characterisation of zirconium-based conversion coating on steel
Authors: Mi D. , Yang C.
Published: November 2016

Zirconium-based conversion coating (ZrCC) was successfully prepared on the samples of cold-rolled steel from the solution of H2ZrF6 and HNO3 at controlled pH. Its surface morphology was analysed by the 3D optical microscope and scanning electron microscope. Its chemical composition and structure were investigated by energy-dispersive X-ray spectroscopy, X-ray diffraction analysis and X-ray photoelectron spectroscopy. The open-circuit potential measurement was used to study the coating formation process, and the electrochemical impedance spectroscopy test was employed to analyze the behaviors of the coatings prepared at different deposition time. According to the analysis results, the deposition mechanism of ZrCC on steel was proposed, and the chemical schematic diagram was also designed. The corrosion resistance performance of ZrCC with cathodic electrodeposition primers was also evaluated by salt spray exposure of 1000 h.
Historical Diets of Forage Fish and Juvenile Pacific Salmon in the Strait of Georgia, 1966–1968
Authors: Osgood Geoffrey J. , Kennedy Laura A. , Holden Jessica J. , Hertz Eric , McKinnell Skip , Juanes Francis
Published: November 2016

The Strait of Georgia, British Columbia, provides important feeding and rearing habitat for forage fish, such as Pacific Herring Clupea pallasii and Eulachon Thaleichthys pacificus as well as all species of North American Pacific salmon Oncorhynchus spp. during their juvenile out-migration. In recent decades, this region has undergone large-scale physical and biological changes. Pacific Herring and Pacific salmon populations have experienced dramatic population fluctuations, while Eulachon have failed to recover from precipitous declines in the 1990s. Archival records of stomach content data from the 1960s, collected primarily from juvenile Pacific salmon, Pacific Herring, and Eulachon, allowed us to investigate diet variability in these species 60 years ago. Consistent with contemporary reports, we found that all species except Eulachon had generalist diets. In contrast to recent studies finding that Pacific Herring are the most important fish prey, Eulachon were the most frequently consumed fish, occurring in 28% of all piscivorous fish stomachs. This suggests that Pacific Herring are an important component of some Pacific salmon diets now, but only because lipid-rich Eulachon are no longer available. Chinook Salmon O. tshawytscha and Coho Salmon O. kisutch had the most similar diets, in part because of their greater piscivory. Species, length, and month and year of capture showed some explanatory power in differentiating the diets of the fish, although they explained less than 10% of total diet variation. Historical data, such as those presented here, offer a unique opportunity to investigate temporal differences in foraging ecology, informing management on how changes in the Strait of Georgia ecosystem may impact the trophic interactions between species.

Received September 30, 2015; accepted July 5, 2016
NK cells converge lytic granules to promote cytotoxicity and prevent bystander killing
Authors: Hsu Hsiang-Ting , Mace Emily M. , Carisey Alexandre F. , Viswanath Dixita I. , Christakou Athanasia E. , Wiklund Martin , Önfelt Björn , Orange Jordan S.
Published: November 2016

Natural killer (NK) cell activation triggers sequential cellular events leading to destruction of diseased cells. We previously identified lytic granule convergence, a dynein- and integrin signal–dependent movement of lysosome-related organelles to the microtubule-organizing center, as an early step in the cell biological process underlying NK cell cytotoxicity. Why lytic granules converge during NK cell cytotoxicity, however, remains unclear. We experimentally controlled the availability of human ligands to regulate NK cell signaling and promote granule convergence with either directed or nondirected degranulation. By the use of acoustic trap microscopy, we generated specific effector–target cell arrangements to define the impact of the two modes of degranulation. NK cells with converged granules had greater targeted and less nonspecific “bystander” killing. Additionally, NK cells in which dynein was inhibited or integrin blocked under physiological conditions demonstrated increased nondirected degranulation and bystander killing. Thus, NK cells converge lytic granules and thereby improve the efficiency of targeted killing and prevent collateral damage to neighboring healthy cells.
Influence of Temperature on Development and Reproduction of Ditylenchus weischeri and D. dipsaci on Yellow Pea
Authors: Hajihassani Abolfazl , Tenuta Mario , Gulden Robert H.
Published: November 2016

The ability of the recently described stem nematode of creeping thistle (Cirsium arvense L.), Ditylenchus weischeri, to develop on and parasitize yellow pea (Pisum sativum L.) is uncertain. The current study examined nematode life-stage progression and generation time on yellow pea as affected by temperature with the related pest, D. dipsaci, used as a positive control. Relationships for body length of the two nematode species and life stage were unaffected by rearing on plant hosts compared with carrot disks. Then plant-reared J4 individuals of both nematode species were used to determine the effect of temperature (17, 22, and 27°C) on life-stage progression and minimum generation time with yellow pea. At 17 and 22°C, D. weischeri J4 individuals progressed to only the adult stage whereas, at 27°C, the minimum generation time from J4 to J4 was 30 days or 720 growing degree-days. The minimum generation time for D. dipsaci was 24, 18, and 22 days or 336, 342, and 528 growing degree-days at 17, 22, and 27°C, respectively. The results indicate that development of D. weischeri is temperature dependent and reproduction is unlikely on yellow pea in the Canadian Prairies, where mean daily air temperatures of 27°C are rare and not sustained.
Rallying the Troops
Authors: Brødsgaard Anne , Helth Theresa , Andersen Bente Lund , Petersen Mette
Published: November 2016

Background:

Research concludes that there is a need for educational programs for grandmothers, as well as networking opportunities; educational programs for other extended family members have long been sought by parents, relatives, and nurses in neonatal intensive care unit.

Purpose:

To describe the effect of having premature infants' extended families participating in family-centered care (FCC) groups in the neonatal intensive care unit. An intervention based on dialogue, including topics as own reactions, general knowledge about the premature infants, parenthood, and how the extended families can support the new families during hospitalization and after discharge.

Methods:

A qualitative content analysis of 2 focus group interviews involving 16 purposefully sampled extended family members, who had participated in 1½ hours of FCC group interventions.

Findings:

The overall theme was: Accepting the individuality of the infant and providing the family with realistic expectations for the future. This theme emerged during the analysis of 4 categories: knowledge sharing, same basis for understanding, access to the immediate family, and competent supporting role. The interrelationship between the categories also emerged, surprisingly, during the analysis.

Implications for Practice:

Extended family members should be recognized as an essential part of the new family's life from the time of the premature infant's admission to neonatal intensive care unit. Family-centered care group interventions should be integrated into ward practice and policy.

Implications for Research:

The study reinforces the need for further research, utilizing both qualitative and quantitative methods, into age and ethnicity aspects of FCC group interventions. There is also a need to compare the new parents' perceived level of stress and support from the FCC group intervention in relation to participating and nonparticipating extended families.
Understanding Negative Predictive Value of Diagnostic Tests Used in Clinical Practice
Authors: Umberger Reba A. , Hatfield Linda A. , Speck Patricia M.
Published: November 2016

Nurses review, evaluate, and use diagnostic test results on a routine basis. However, the skills necessary to evaluate a particular test using statistical outcome measures is often lacking. The purpose of this article is to examine and interpret the underlying principles for use of the statistical outcomes of diagnostic screening tests (sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values, with a discussion about use of SpPIn [Specificity, Positive test = rule in], and SnNOut [Sensitivity, Negative test = rule out]) in advanced nursing clinical practice. The authors focus on NPVs because test results with high NPV are useful to practitioners when considering unnecessary, costly, and possibly risky treatments, whether using clinical assessment tool, test, or procedure or using polymerase chain reaction analysis of DNA test results. In this article, the authors emphasize the use of NPV in treatment decisions by providing examples from critical care, neonatal, and advanced forensic nursing, which become a framework for assessing decisions in the clinical arena. This commentary stresses the importance of the NPV of tests in preventing, detecting, and ruling out disease, where PPV may not be relevant for that purpose. Negative predictive value percentages inform treatment decisions when the provider understands the biology, chemistry, and foundation for testing methods used in clinical practices. The art of diagnosis, confirmed in a test’s high NPV (meaning the patient probably does not have the disease when the test is negative), reassures provider treatment stewardship to do no harm.
The Effect of Topical Use of Petroselinum Crispum (Parsley) Versus That of Hydroquinone Cream on Reduction of Epidermal Melasma
Authors: Khosravan Shahla , Alami Ali , Mohammadzadeh-Moghadam Hossein , Ramezani Vahide
Published: November 2016

Melasma disfigures the skin and thus influences people's self-image and self-concept. Therefore, melasma influences emotional and psychosocial health in addition to physical health. This clinical trial was performed to assess the effect of the topical use of Petroselinum crispum (parsley) on reduction of the severity of epidermal melasma.
CYSTOID MACULAR EDEMA AND CYSTOID MACULAR DEGENERATION AS A RESULT OF MULTIPLE PATHOGENIC FACTORS IN THE SETTING OF CENTRAL SEROUS CHORIORETINOPATHY
Authors: Astroz Polina , Balaratnasingam Chandrakumar , Yannuzzi Lawrence A.
Published: November 2016

Purpose:

To report the pathogenic factors that account for cystoid macular edema and cystoid macular degeneration in chronic central serous chorioretinopathy (CSC).

Methods:

The clinical course and multimodal imaging findings, including fundus color photography, fundus autofluorescence, spectral-domain optical coherence tomography, and fluorescein angiography, of one eye with cystoid macular edema due to chronic CSC was documented.

Results:

A 44-year old woman with a history of chronic CSC presented with progressive visual decline in the right eye. Best-corrected visual acuity was 20/40. Funduscopic examination revealed diffuse retinal pigment epithelial changes and macular edema. Fluorescein angiography demonstrated perifoveal microaneurysms and leakage in a petaloid configuration. Spectral-domain optical coherence tomography demonstrated cysts at the level of the inner nuclear layer, an epiretinal membrane, vitreomacular traction, and an attenuated retinal pigment epithelial band. Central subfield thickness was 486 μm. Three intravitreal injections of aflibercept were administered over 16 weeks following which there was resolution of leakage, release of vitreomacular traction, and resolution of microaneurysms. Central subfield thickness reduced to 379 μm, but persistent intraretinal cysts were observed. There was subjective improvement in visual symptoms, but Snellen acuity remained at 20/40.

Conclusion:

Intraretinal cystic changes in chronic CSC may be the result of multifactorial pathogenic factors and may represent the coexistence of cystoid macular edema and cystoid macular degeneration. Anti–vascular endothelial growth factor may play an important role in the treatment of cystoid macular edema caused by CSC.
Lean Six Sigma to Reduce Intensive Care Unit Length of Stay and Costs in Prolonged Mechanical Ventilation
Authors: Trzeciak Stephen , Mercincavage Michael , Angelini Cory , Cogliano William , Damuth Emily , Roberts Brian W. , Zanotti Sergio , Mazzarelli Anthony J.
Published: November 2016

Objective:

Patients with prolonged mechanical ventilation (PMV) represent important “outliers” of hospital length of stay (LOS) and costs (∼$26 billion annually in the United States). We tested the hypothesis that a Lean Six Sigma (LSS) approach for process improvement could reduce hospital LOS and the associated costs of care for patients with PMV.

Design:

Before-and-after cohort study.

Setting:

Multidisciplinary intensive care unit (ICU) in an academic medical center.

Patients:

Adult patients admitted to the ICU and treated with PMV, as defined by diagnosis-related group (DRG).

Methods:

We implemented a clinical redesign intervention based on LSS principles. We identified eight distinct processes in preparing patients with PMV for post-acute care. Our clinical redesign included reengineering daily patient care rounds (“Lean ICU rounds”) to reduce variation and waste in these processes. We compared hospital LOS and direct cost per case in patients with PMV before (2013) and after (2014) our LSS intervention.

Results:

Among 259 patients with PMV (131 preintervention; 128 postintervention), median hospital LOS decreased by 24% during the intervention period (29 vs. 22 days, p < .001). Accordingly, median hospital direct cost per case decreased by 27% ($66,335 vs. $48,370, p < .001).

Conclusion:

We found that a LSS-based clinical redesign reduced hospital LOS and the costs of care for patients with PMV.
Noninvasive markers of liver fibrosis: on-treatment changes of serum markers predict the outcome of antifibrotic therapy
Authors: Tanwar Sudeep , Trembling Paul M. , Hogan Brian J. , Srivastava Ankur , Parkes Julie , Harris Scott , Grant Paul , Nastouli Eleni , Ocker Mathias , Wehr Klaus , Herold Christoph , Neureiter Daniel , Schuppan Detlef , Rosenberg William M.
Published: November 2016

Aim

The utility of noninvasive serum markers to longitudinally monitor liver fibrosis is not established.

Methods

A total of 70 patients with chronic hepatitis C who had previously failed antiviral therapy were randomized to receive pegylated interferon with or without silymarin for 24 months. Enhanced Liver Fibrosis (ELF) tests (hyularonic acid, terminal peptide of procollagen III, tissue inhibitor of matrix metaloproteinase-1) were performed on patient sera obtained before, during and at the end of the study (0, 12, 24 months) and liver histology obtained before and at the end of the study.

Results

At 24 months, absolute changes in Ishak fibrosis stage and ELF ranged from −4 to +4 and from −2.41 to +2.68, respectively. Absolute changes in ELF at 12 months were significantly associated with changes in both ELF and histology at 24 months. A model combining both baseline ELF and change of ELF at 12 months could predict the 24-month ELF (R
2=0.609, P<1×10–11), a decrease in ELF at 24 months [area under the curve (AUC): 0.80–0.85] and an increase in ELF at 24 months (AUC: 0.81–0.85). Furthermore, a model combining both baseline histologic stage and ELF together with the change of ELF at 12 months could predict 24-month histology (R
2=0.601, P<1×10–11, AUC: 0.88–0.92), histologic fibrosis regression (AUC: 0.81–0.84) and progression (AUC: 0.86–0.91).

Conclusion

Our observations suggest that a change in the serum marker ELF predicts changes in liver fibrosis over a longer period. These data support the use of ELF as a surrogate marker of liver fibrosis evolution in monitoring antifibrotic treatments, thus permitting ‘response-guided’ therapy by the early identification of patients who will benefit from prolonged treatment.
Milk fat biomarkers and cardiometabolic disease
Authors: Risérus Ulf , Marklund Matti
Published: November 2016

Purpose of review

Dairy is a major food group with potential impact on cardiometabolic health. Self-reported dairy intake has limitations that can partly be avoided by using biomarkers. This review aims to summarize the evidence of odd-chain saturated fatty acids (OCFAs), that is, pentadecanoic acid (C15 : 0) and heptadecanoic acid (17 : 0), as biomarkers of dairy fat intake. In addition, the associations of OCFA biomarkers with cardiometabolic disease will be overviewed.

Recent findings

Adipose tissue 15 : 0 is the preferred biomarker but also circulating 15 : 0, and to a weaker extent 17 : 0, reflects both habitual and changes in dairy intake. Whereas results from studies assessing cardiovascular outcomes are inconsistent, OCFA biomarkers are overall associated with lower diabetes risk. Residual confounding should however be considered until interventional data and mechanisms are available. Although OCFA biomarkers mainly reflect dairy fat intake, recently proposed endogenous synthesis and metabolism do motivate further research.

Taking into account the study population diet and limitations of OCFA biomarkers, both adipose and circulating levels of 15 : 0, in particular, are useful for estimating total dairy fat intake. OCFA biomarkers are overall not linked to cardiovascular disease risk, but a possible beneficial role of dairy foods in diabetes prevention warrant further study.
NASPGHAN Clinical Practice Guideline for the Diagnosis and Treatment of Nonalcoholic Fatty Liver Disease in Children
Authors: Vos Miriam B. , Abrams Stephanie H. , Barlow Sarah E. , Caprio Sonia , Daniels Stephen R. , Kohli Rohit , Mouzaki Marialena , Sathya Pushpa , Schwimmer Jeffrey B. , Sundaram Shikha S. , Xanthakos Stavra A.
Published: November 2016

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent chronic liver disease that occurs in the setting of insulin resistance and increased adiposity. It has rapidly evolved into the most common liver disease seen in the pediatric population and is a management challenge for general pediatric practitioners, subspecialists, and for health systems. In this guideline, the expert committee on NAFLD reviewed and summarized the available literature, formulating recommendations to guide screening and clinical care of children with NAFLD.
Essential Content for Discharge Instructions in Pediatric Emergency Care
Authors: Curran Janet A. , Murphy Andrea , Burns Emma , Plint Amy , Taljaard Monica , MacPhee Shannon , Fitzpatrick Eleanor , Bishop Andrea , Chorney Jill , Bourque Megan
Published: November 2016

Objective

The aim of this study was to identify the 5 most essential discharge instruction content elements that should be communicated to all caregivers of children who present to the emergency department (ED) with asthma, vomiting/diarrhea, abdominal pain, fever, minor head injury, or bronchiolitis.

Methods

A discharge information content list was developed for each illness presentation following a review of the literature. Using a modified Delphi technique, 6 lists were distributed to a panel of experts from EDs across Canada using a secure online survey tool with the goal of achieving the 5 most essential discharge instruction elements.

Results

A total of 37 emergency clinicians completed all 4 rounds of the Delphi. Consensus for the final 30 content items ranged from 51.4% to 100%. Items pertaining to diarrhea/vomiting, abdominal pain, fever, and bronchiolitis obtained relatively high levels of consensus for all top 5 items. The majority of items (n = 19 [63.3%]) that reached consensus across the illness presentations were associated with instructions intended to educate caregivers on instances when they should return to the ED department.

Conclusions

Findings from this study provide a better understanding of what should be communicated to caregivers of children who present to the ED with a number of different illness presentations. Results from this study suggest that health care providers agree on the importance of providing information to caregivers regarding when to return to the ED with their child. Reaching consensus among all experts in this study provides insight into the difficulty of standardizing discharge communication in the absence of widely accepted guidelines.
Repeated evolution of viviparity in phrynosomatid lizards constrained interspecific diversification in some life-history traits
Authors: Zúñiga-Vega J. Jaime , Fuentes-G. Jesualdo A. , Ossip-Drahos Alison G. , Martins Emília P.
Published: November 2016

In vertebrates, viviparity has evolved independently multiple times, apparently increasing morphological diversification and speciation rates as a consequence. We tested whether the evolution of viviparity has also increased diversification of life-history traits by estimating evolutionary rates of lizards from the North American family Phrynosomatidae. Using modern phylogenetic comparative methods, we compared these rates between oviparous and viviparous species, and found no support for this hypothesis. Instead, we found higher evolutionary rates for oviparous species in some life-history traits. Our results suggest that the evolution of viviparity may have constrained rather than facilitated evolution of life histories.
Terrain following and applications:Caenorhabditis elegansswims along the floor using a bump and undulate strategy
Authors: Yuan Jinzhou , Ko Hungtang , Raizen David M. , Bau Haim H.
Published: November 2016

Nematodes such asCaenorhabditis elegansare heavier than water. When submerged in water, they settle to the bottom surface. Observations reveal that the animals do not lie flat on the bottom surface, but remain substantially suspended above the surface through continuous collisions with the surface, while maintaining their swimming gaits. Consequently, the swimming animals follow the bottom surface topography. When the bottom surface is inclined, the animals swim up or down along the incline. As the magnitude of the gravitational force can be easily estimated, this behaviour provides a convenient means to estimate the animal's propulsive thrust. The animals' tendency to follow the surface topography provides a means to control the swimmers' trajectories and direction of motion, which we demonstrate with a saw tooth-like ratchet that biases the animals to swim in a selected direction. The animals can also serve as surface topography probes since their residence time as a function of position provides information on surface features. Finally, we take advantage of surface following to construct a simple motility-based sorter that can sort animals based on genotype and state of health.
The distinct fate of smooth and roughMycobacterium abscessusvariants inside macrophages
Authors: Roux Anne-Laure , Viljoen Albertus , Bah Aïcha , Simeone Roxane , Bernut Audrey , Laencina Laura , Deramaudt Therese , Rottman Martin , Gaillard Jean-Louis , Majlessi Laleh , Brosch Roland , Girard-Misguich Fabienne , Vergne Isabelle , de Chastellier Chantal , Kremer Laurent , Herrmann Jean-Louis
Published: November 2016

Mycobacterium abscessusis a pathogenic, rapidly growing mycobacterium responsible for pulmonary and cutaneous infections in immunocompetent patients and in patients with Mendelian disorders, such as cystic fibrosis (CF).Mycobacterium abscessusis known to transition from a smooth (S) morphotype with cell surface-associated glycopeptidolipids (GPL) to a rough (R) morphotype lacking GPL. Herein, we show thatM. abscessusS and R variants are able to grow inside macrophages and are present in morphologically distinct phagosomes. The S forms are found mostly as single bacteria within phagosomes characterized by a tightly apposed phagosomal membrane and the presence of an electron translucent zone (ETZ) surrounding the bacilli. By contrast, infection with the R form leads to phagosomes often containing more than two bacilli, surrounded by a loose phagosomal membrane and lacking the ETZ. In contrast to the R variant, the S variant is capable of restricting intraphagosomal acidification and induces less apoptosis and autophagy. Importantly, the membrane of phagosomes enclosing the S forms showed signs of alteration, such as breaks or partial degradation. Although not frequently encountered, these events suggest that the S form is capable of provoking phagosome–cytosol communication. In conclusion,M. abscessusS exhibits traits inside macrophages that are reminiscent of slow-growing mycobacterial species.
Tumour-suppressor microRNAs regulate ovarian cancer cell physical properties and invasive behaviour
Authors: Chan Clara K. , Pan Yinghong , Nyberg Kendra , Marra Marco A. , Lim Emilia L. , Jones Steven J. M. , Maar Dianna , Gibb Ewan A. , Gunaratne Preethi H. , Robertson A. Gordon , Rowat Amy C.
Published: November 2016

The activities of pathways that regulate malignant transformation can be influenced by microRNAs (miRs). Recently, we showed that increased expression of five tumour-suppressor miRs, miR-508-3p, miR-508-5p, miR-509-3p, miR-509-5p and miR-130b-3p, correlate with improved clinical outcomes in human ovarian cancer patients, and that miR-509-3p attenuates invasion of ovarian cancer cell lines. Here, we investigate the mechanism underlying this reduced invasive potential by assessing the impact of these five miRs on the physical properties of cells. Human ovarian cancer cells (HEYA8, OVCAR8) that are transfected with miR mimics representing these five miRs exhibit decreased invasion through collagen matrices, increased cell size and reduced deformability as measured by microfiltration and microfluidic assays. To understand the molecular basis of altered invasion and deformability induced by these miRs, we use predicted and validated mRNA targets that encode structural and signalling proteins that regulate cell mechanical properties. Combined with analysis of gene transcripts by real-time PCR and image analysis of F-actin in single cells, our results suggest that these tumour-suppressor miRs may alter cell physical properties by regulating the actin cytoskeleton. Our findings provide biophysical insights into how tumour-suppressor miRs can regulate the invasive behaviour of ovarian cancer cells, and identify potential therapeutic targets that may be implicated in ovarian cancer progression.
Cycle and flow trusses in directed networks
Authors: Takaguchi Taro , Yoshida Yuichi
Published: November 2016

When we represent real-world systems as networks, the directions of links often convey valuable information. Finding module structures that respect link directions is one of the most important tasks for analysing directed networks. Although many notions of a directed module have been proposed, no consensus has been reached. This lack of consensus results partly because there might exist distinct types of modules in a single directed network, whereas most previous studies focused on an independent criterion for modules. To address this issue, we propose a generic notion of the so-called truss structures in directed networks. Our definition of truss is able to extract two distinct types of trusses, named the cycle truss and the flow truss, from a unified framework. By applying the method for finding trusses to empirical networks obtained from a wide range of research fields, we find that most real networks contain both cycle and flow trusses. In addition, the abundance of (and the overlap between) the two types of trusses may be useful to characterize module structures in a wide variety of empirical networks. Our findings shed light on the importance of simultaneously considering different types of modules in directed networks.
The role of cell replacement in benthic–pelagic coupling by suspension feeders
Authors: Kahn Amanda S. , Leys Sally P.
Published: November 2016

Benthic–pelagic coupling through suspension feeders and their detrital pathways is integral to carbon transport in oceans. In food-poor ecosystems however, a novel mechanism of carbon recycling has been proposed that involves direct uptake of dissolved carbon by suspension feeders followed by shedding of cells as particulate carbon. We studied cell replacement rates in a range of cold-water sponge species to determine how universal this mechanism might be. We show that cell replacement rates of feeding epithelia in explants vary from 30 hours up to 7 days, and change during different seasons and life-history stages. We also found that feeding epithelia are not replaced through direct replication but instead arise from a population of stem cells that differentiate and integrate into epithelial tissues. Our results reveal a surprising amount of complexity in the control of cell processes in sponges, with cell turnover depending on environmental conditions and using stem cells as rate-limiting mechanisms. Our results also suggest that for species in cold water with high particulate organic matter, cell turnover is not the mechanism delivering carbon flux to surrounding communities.
Matrix basis for plane and modal waves in a Timoshenko beam
Authors: Claeyssen Julio Cesar Ruiz , Tolfo Daniela de Rosso , Tonetto Leticia
Published: November 2016

Plane waves and modal waves of the Timoshenko beam model are characterized in closed form by introducing robust matrix basis that behave according to the nature of frequency and wave or modal numbers. These new characterizations are given in terms of a finite number of coupling matrices and closed form generating scalar functions. Through Liouville’s technique, these latter are well behaved at critical or static situations. Eigenanalysis is formulated for exponential and modal waves. Modal waves are superposition of four plane waves, but there are plane waves that cannot be modal waves. Reflected and transmitted waves at an interface point are formulated in matrix terms, regardless of having a conservative or a dissipative situation. The matrix representation of modal waves is used in a crack problem for determining the reflected and transmitted matrices. Their euclidean norms are seen to be dominated by certain components at low and high frequencies. The matrix basis technique is also used with a non-local Timoshenko model and with the wave interaction with a boundary. The matrix basis allows to characterize reflected and transmitted waves in spectral and non-spectral form.
Eliminating incident subtraction in diffraction tomography
Authors: Huthwaite P.
Published: November 2016

Diffraction tomography is a powerful algorithm for producing high-resolution quantitative reconstructions across a wide range of applications. A major drawback of the method is that it operates on the scattered field, which cannot generally be directly measured, but must instead be calculated by subtracting the incident field, i.e. the equivalent field with no scatterer present. Unfortunately, often the incident field is not measurable and hence must be estimated, causing errors. This paper highlights an important, but not widely recognized, result: for particular widely used formulations of the algorithm, the subtraction of the incident field is unnecessary, and the algorithm can actually be applied directly to measured signals. The theory behind this is derived, showing that the incident field will vanish under far-field conditions, and the result is demonstrated in practice. Tests with subsampled arrays show that aliasing artefacts can appear, but can be removed with a filter at the expense of resolution. The incident field also has no effect for a variety of array configurations tested. Finally, the performance in the presence of both correlated and uncorrelated errors is confirmed, in all cases demonstrating that the incident field has a negligible effect on the final reconstruction.
Mechanics of advection of suspended particles in turbulent flow
Authors: Ali Sk Zeeshan , Dey Subhasish
Published: November 2016

In this paper, we explore the mechanics and the turbulent structure of two-phase (fluid–solid particle) flow system, for the first time, by considering the dynamic equilibrium coupled with suspended solid particle concentration, fluid flow and energetics of the two-phase flow system. The continuity, momentum and turbulent kinetic energy (TKE) equations of the fluid and the solid phases are treated separately to derive a generalized relationship of the two-phase flow system aided by suitable closure relationships. The results obtained from the numerical solution of resulting equations show that the particle concentration and the TKE diminish with an increase in the Rouse number, while the horizontal velocity component increases. On the other hand, the TKE flux, diffusion and production rates increase with an increase in the Rouse number, while the TKE dissipation rate decreases. In the vicinity of the reference level (that is, the hypothetical level from which the particles come in suspension), the Kolmogorov number increases with an increase in the Rouse number. However, as the vertical distance increases, this behaviour becomes reverse. A close observation of the turbulent length scales reveals that the Prandtl's mixing length decreases with an increase in the Rouse number, but the Taylor microscale and the Kolmogorov length scale increase.