bluuebunny/crossref_metadata_2025 huggingface dataset:
A fictitious domain method for the simulation of thermoelastic deformations in NC‐milling processes
Authors: Byfut A. , Schröder A.
Published: June 2017

This paper presents a (higher‐order) finite element approach for the simulation of heat diffusion and thermoelastic deformations in NC‐milling processes. The inherent continuous material removal in the process of the simulation is taken into account via continuous removal‐dependent refinements of a paraxial hexahedron base‐mesh covering a given workpiece. These refinements rely on isotropic bisections of these hexahedrons along with subdivisions of the latter into tetrahedrons and pyramids in correspondence to a milling surface triangulation obtained from the application of the marching cubes algorithm. The resulting mesh is used for an element‐wise defined characteristic function for the milling‐dependent workpiece within that paraxial hexahedron base‐mesh. Using this characteristic function, a (higher‐order) fictitious domain method is used to compute the heat diffusion and thermoelastic deformations, where the corresponding ansatz spaces are defined for some hexahedron‐based refinement of the base‐mesh. Numerical experiments compared to real physical experiments exhibit the applicability of the proposed approach to predict deviations of the milled workpiece from its designed shape because of thermoelastic deformations in the process.
Glycogen synthase kinase‐3β ablation limits pancreatitis‐induced acinar‐to‐ductal metaplasia
Authors: Ding Li , Liou Geou‐Yarh , Schmitt Daniel M , Storz Peter , Zhang Jin‐San , Billadeau Daniel D
Published: June 2017

Acinar‐to‐ductal metaplasia (ADM) is a reversible epithelial transdifferentiation process that occurs in the pancreas in response to acute inflammation. ADM can rapidly progress towards pre‐malignant pancreatic intraepithelial neoplasia (PanIN) lesions in the presence of mutant KRas and ultimately pancreatic adenocarcinoma (PDAC). In the present work, we elucidate the role and related mechanism of glycogen synthase kinase‐3beta (GSK‐3β) in ADM development using in vitro 3D cultures and genetically engineered mouse models. We show that GSK‐3β promotes TGF‐α‐induced ADM in 3D cultured primary acinar cells, whereas deletion of GSK‐3β attenuates caerulein‐induced ADM formation and PanIN progression in KrasG12D transgenic mice. Furthermore, we demonstrate that GSK‐3β ablation influences ADM formation and PanIN progression by suppressing oncogenic KRas‐driven cell proliferation. Mechanistically, we show that GSK‐3β regulates proliferation by increasing the activation of S6 kinase. Taken together, these results indicate that GSK‐3β participates in early pancreatitis‐induced ADM and thus could be a target for the treatment of chronic pancreatitis and the prevention of PDAC progression. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Poly(lactic acid) composites reinforced with leaf fibers from ornamental variety of hybrid pineapple (Potyra)
Authors: Sena Neto Alfredo R. , Claro Pedro I.C. , Souza Fernanda V.D. , Mattoso Luiz H.C. , Marconcini José M.
Published: June 2017

While there have been many studies of fibers extracted from pineapple leaves as reinforcement in polymer composites, to date, only commercial varieties have been examined. This work aims to investigate the fibers from the leaves of a hybrid pineapple called Potyra as a mechanical reinforcement in a poly(lactic acid) (PLA) matrix. The fibers were pre‐treated in a NaOH solution (1 wt%) and were incorporated into the PLA by a torque rheometer mixer followed by twin‐screw extrusion. Samples of each composition were injected. The molded composites showed increases of tensile strength from 58.8 to 69.6 MPa, of Young's modulus from 1.9 to 3.5 GPa, and of impact resistance from 28 to 44 J/m, and showed an increase of 5°C in the heat deflection temperature (Abstract Figure). The measured tensile strength and Young's modulus values are lower than the theoretical values obtained by micromechanics theory due to the pull‐out of the matrix fiber and due to the orientation of the fibers in the composites. It was concluded that the pineapple hybrid fibers have potential for use as mechanical reinforcement in green composites. POLYM. COMPOS., 39:4050–4057, 2018. © 2017 Society of Plastics Engineers
Toward a versatile toolbox for cucurbit[n]uril‐based supramolecular hydrogel networks through in situ polymerization
Authors: Liu Ji , Soo Yun Tan Cindy , Lan Yang , Scherman Oren A.
Published: June 2017

The success of exploiting cucurbit[n]uril (CB[n])‐based molecular recognition in self‐assembled systems has sparked a tremendous interest in polymer and materials chemistry. In this study, polymerization in the presence of host‐guest complexes is applied as a modular synthetic approach toward a diverse set of CB[8]‐based supramolecular hydrogels with desirable properties, such as mechanical strength, toughness, energy dissipation, self‐healing, and shear‐thinning. A range of vinyl monomers, including acrylamide‐, acrylate‐, and imidazolium‐based hydrophilic monomers, could be easily incorporated as the polymer backbones, leading to a library of CB[8] hydrogel networks. This versatile strategy explores new horizons for the construction of supramolecular hydrogel networks and materials with emergent properties in wearable and self‐healable electronic devices, sensors, and structural biomaterials. © 2017 The Authors. Journal of Polymer Science Part A: Polymer Chemistry Published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3105–3109
A Model for Quantifying Ground‐Ice Volume, Yukon Coast, Western Arctic Canada
Authors: Couture Nicole J. , Pollard Wayne H.
Published: June 2017

A morphological model for estimating ground‐ice contents of various landscape units is presented to address the gap between large‐scale, general studies and small‐scale, site‐specific case histories. The model considers different ground‐ice types and cryostratigraphic relations between ice bodies within a terrain unit. Input parameters needed for the model are described. Derived variables and algorithms used to determine the quantity of each ground‐ice type within a terrain unit are presented. Examples of the application of the model are provided for the Yukon Coastal Plain, northwest Canada. The uncertainties and limiting assumptions of the model are discussed. Copyright © 2017 Natural Resources Canada. Permafrost and Periglacial Processes © 2017 John Wiley & Sons, Ltd.
The In Vitro and In Vivo Biological Activities of the Leaf of Cape Myrtle, Myrsine africana L.
Authors: Gul Hina , Ahmad Mushtaq , Zafar Muhammad , Sheeraz Ahmad Muhammad , Abid Ambreen , Hira Syeda , Shah Imam , Gulfraz Muhammad
Published: June 2017

The cape myrtle, Myrsine africana L., is a widely used medicinal plant, which has not been well investigated. We assessed the in vivo hepatoprotective and in vitro antiproliferative and antioxidant effects of leaf extracts of M. africana chemically profiled using high‐performance liquid chromatography. Three flavonoids were quantified, and gas chromatography–mass spectrometry analysis revealed the presence of common fatty acids. The animal study was conducted on mice treated with CCl4, using three doses each of the methanol and chloroform extract (100, 200 and 300 mg/kg b.w.),with silymarin as a positive control. Hepatoprotective effects were determined by analyzing blood for liver marker and antioxidant enzymes, direct bilirubins and total proteins. The methanol extract (300 mg/kg b.w.) showed the strongest hepatoprotective effects against abnormalities produced by CCl4. The in vivo hepatoprotective effects correlated well with the in vitro antioxidant and antiproliferative activities and with high levels of flavonoids in the extracts. Finally, molecular docking studies of the constituent quercetin were undertaken in silico and several sites of binding to human estrogen receptor (ER) protein, linked with alkaline phosphatase, identified. Copyright © 2017 John Wiley & Sons, Ltd.
Accelerated light protection performance measurement technology validated for dairy milk packaging design
Authors: Stancik Cheryl M. , Conner Denise A. , Jernakoff Peter , Niedenzu Philipp M. , Duncan Susan E. , Bianchi Laurie M. , Johnson Daryan S.
Published: June 2017

We report an accelerated measurement technology for prediction of light protection performance of milk packaging by quantifying the ability of a package to preserve a light‐sensitive nutrient present in milk. This measurement technology consists of a light exposure instrument and a detection approach to track changes to the light‐sensitive nutrient, riboflavin (RF), in a light‐exposed solution sample. The light exposure instrument provided an intense, controlled light exposure and a consistent sample environment for an aqueous RF marker solution. Coupled with the light exposure instrument, two alternative detection approaches were used to determine the RF concentration of light‐exposed marker solutions: an accelerated ex situ (AES) approach by high‐performance liquid chromatography or an accelerated in situ (AIS) approach by ultraviolet–visible spectrometry. The capability of each RF determination method was confirmed using measurement systems analysis, and their statistical equivalency was demonstrated. To explore application of the measurement technology for use in package design, a set of high‐density polyethylene packages incorporating surface‐treated TiO2 pigments was evaluated for light protection performance by AES and AIS. For the same package set, experiments monitoring RF degradation in extended‐shelf‐life milk products under retail dairy storage conditions showed strong correlation with the AIS method (R2 > 0.97). Riboflavin retention increased under both retail and accelerated light exposure conditions for package designs containing greater loadings of surface‐treated TiO2 confirming its light protection efficacy. This research illustrates the utility of the accelerated methods to quantitatively evaluate package designs for light protection performance for nutrient preservation.
A preliminary study of cushion properties of a 3D printed thermoplastic polyurethane Kelvin foam
Authors: Ge Changfeng , Priyadarshini Lakshmi , Cormier Denis , Pan Liao , Tuber Jonathan
Published: June 2017

The cells in conventional packaging foams have random size and orientation, and the energy‐absorbing behaviour of these foams is determined by the collective contribution of different sizes of cells. In contrast to the random nature of stochastic foams, 3D printing technologies allow engineers to design and produce foams having engineered cellular structures. In this study, engineered cellular structures based on the classic Kelvin 1887 model were 3D printed in 30 × 30 × 30 mm thermoplastic polyurethane cubes with a repeating size of 216 unit cells. One hundred consecutive cyclic compression tests were performed to assess the 3D printed foam's resilience and energy absorption characteristics. The stress‐strain curve of the 3D printed thermoplastic polyurethane foam indicated viscoelastic behaviour and a Mullins effect indicative of resilient rubber. A long wave buckling mode was observed during cyclic compression cycles due to the Kelvin structure. The cushion factor computed from the stress‐strain curve was close to that of a metal spring with linear elasticity. The combination of the 3D printed foam's resilience, its much lower density than rubber, and the complete geometric freedom of the engineered cellular structures offer designers the potential to create high‐performance cushion materials tailored for packaging applications.
Implicit treatment of model error using inflated observation‐error covariance
Authors: Gejadze I. , Oubanas H. , Shutyaev V.
Published: June 2017

Data assimilation involving imperfect dynamical models is an important topic in meteorology, oceanography and other geophysical applications. In filtering methods, the model error is compensated for by inflation. In variational data assimilation, authors usually try to estimate it, which means that all uncertainty‐loaded model inputs are included into the control vector. However, this approach suffers from implementation difficulties. In this paper we suggest an alternative method, motivated by the ‘nuisance parameter’ concept known in statistics. This method allows the model error to be treated implicitly by inflating the observation‐error covariance. The equivalency theorem substantiating the method has here been proved. We also consider a case with a biased model error. In the corresponding mixed formulation, the spatially distributed mean error is included into the control vector, whereas the time‐dependent fluctuations around the mean are subjected to the proposed implicit treatment. Numerical experiments for the 1D generalized Burgers' equation illustrate the presented theory. In these experiments the model error related to uncertainty in the advection coefficient has been considered.
Consensus of multi‐agent systems with fixed inner connections
Authors: Feng Yuting , Duan Zhisheng , Ren Wei , Chen Guanrong
Published: June 2017

This paper characterizes a unified consensus region for multi‐agent systems, where there exist fixed physical connections with information exchange. The notions of synchronization region in complex networks and consensus region in multi‐agent systems can be explained under this unified framework. The effect of the coupling terms on the consensus regions in different situations is analyzed specifically. Furthermore, necessary and sufficient conditions for consensus of agents under both distributed state feedback and observer‐based output feedback control are established. On the basis of a parameter‐dependent Lyapunov function, a 2‐step controller design procedure is proposed, which can reduce the conservativeness to some extent in comparison with the conventional direct Lyapunov method. In addition, for the case with disturbance, the robustness of the system is investigated. Finally, some numerical examples are presented to illustrate the theoretical results.
Development and validation of the Workplace Interruptions Measure
Authors: Wilkes Stacy M. , Barber Larissa K. , Rogers Arielle P.
Published: June 2017

In 3 studies, we developed and tested the first comprehensive, self‐report measure of workplace interruptions. The Workplace Interruptions Measure (WIM) is based on a typology of interruptions that included intrusions, distractions, discrepancy detections, and breaks. The four‐factor structure was reduced to a 12‐item measure in Study 1 (N = 317) and confirmed in a diverse sample of employees in Study 2 (N = 160). Study 3 (N = 323) further examined the psychometric properties of the WIM in a sample of university faculty and staff. Studies 2 and 3 demonstrated that both effort‐enhancing interruptions (intrusions, distractions, and discrepancy detections) and recovery‐enhancing interruptions (breaks) were associated with stressors and strains. Distractions, discrepancy detections, and breaks uniquely predicted strain outcomes beyond other workplace stressors (i.e., quantitative workload, interpersonal conflict, and role conflict). We discuss implications of the WIM for the theory and practice of interruptions research.
Writing with Fluid: Structuring Hydrogels with Micrometer Precision by AFM in Combination with Nanofluidics
Authors: Helfricht Nicolas , Mark Andreas , Behr Marina , Bernet Andreas , Schmidt Hans‐Werner , Papastavrou Georg
Published: June 2017

Hydrogels have many applications in biomedical surface modification and tissue engineering. However, the structuring of hydrogels after their formation represents still a major challenge, in particular due to their softness. Here, a novel approach is presented that is based on the combination of atomic force microscopy (AFM) and nanofluidics, also referred to as FluidFM technology. Its applicability is demonstrated for supramolecular hydrogel films that are prepared from low‐molecular weight hydrogelators, such as derivates of 1,3,5‐benzene tricarboxamides (BTAs). BTA films can be dissolved selectively by ejecting alkaline solution through the aperture of a hollow AFM‐cantilever connected to a nanofluidic controller. The AFM‐based force control is essential in preventing mechanical destruction of the hydrogels. The resulting “chemical writing” process is studied in detail and the influence of various parameters, such as applied pressure and time, is validated. It is demonstrated that the achievable structuring precision is primarily limited by diffusion and the aperture dimensions. Recently, various additive techniques have been presented to pattern hydrogels. The here‐presented subtractive approach can not only be applied to structure hydrogels from the large class of reversibly formed gels with superior resolution but would also allow for the selective loading of the hydrogels with active substances or nanoparticles.
Reconfigurable Chiral Self‐Assembly of Peptides through Control of Terminal Charges
Authors: Xie Yanyan , Wang Yuefei , Qi Wei , Huang Renliang , Su Rongxin , He Zhimin
Published: June 2017

Self‐assembly of chiral nanostructures is of considerable interest, since the ability to control the chirality of these structures has direct ramifications in biology and materials science. A new approach to design chiral nanostructures from self‐assembly of N‐(9‐fluorenylmethoxycarbonyl)‐protected phenylalanine‐tryptophan‐lysine tripeptides is reported. The terminal charges can induce helical twisting of the assembled β‐sheets, enabling the formation of well‐defined chiral nanostructures. The degree and direction of twisting in the β‐sheets can be precisely tailored through in situ pH and temperature modulations. This enables the assembly of reconfigurable chiral nanomaterials with easily adjustable size and handedness. These results offer new insight into the mechanism of helical twist formation, which may enable the precise assembly of highly dynamical materials with potential applications in biomedicine, chiroptics, and chiral sensing.
Improved Rayleigh to Compton scattering ratio curves for mass attenuation coefficients determination for X‐ray fluorescence analysis
Authors: Conti C.C. , Anjos M.J. , Salgado C.M.
Published: June 2017

Nondestructive assays are essentials for certain types of sample materials, and, among those, the X‐ray fluorescence technique enables the determinations of stable elements, and there is an increasing effort on the development of equipment to suit the various needs. Nevertheless, a great difficulty on the analysis of unknown materials' composition is to account for self‐absorption of the fluorescence photons that must be considered in the elemental concentration calculation. The correlation between the Rayleigh to Compton scattering ratio to the mass attenuation coefficient has proved to follow a single polynomial function for the first 20 elements of the periodical table with a correlation factor higher than of 0.998 for the sixth order function. The Rayleigh to Compton scattering ratios for pure elements and the 22.16 keV photons, the main energy from an X‐ray tube with silver anode, were determined with the MCNP6 Monte Carlo computer code. Two scattering angles were considered. Reference samples were measured, and the calculated results were compared to the literature values of the mass attenuation coefficient for some known samples and showed to be within 20% for de 90° scattering angle. Only Lucite was slightly above 20%. Curve fit coefficients are also presented for the 7.11‐ and 17.40‐keV photon energies.
A Star‐Shaped Anionic Surfactant: Synthesis, Alkalinity Resistance, Interfacial Tension and Emulsification Properties at the Crude Oil–Water Interface
Authors: Zhang Rui , Cai Youfeng , Wang Jixing , Zhao Zijing , Mao Xu , Peng Zhigang
Published: June 2017

In this research, a star‐shaped surfactant was synthesized through the chlorination reaction, alkylation reaction and sulfonation reaction of triethanolamine, which is composed of three hydrophobic chains and three sulfonate hydrophilic groups. The critical micelle concentration (CMC) of the surfactant was measured by the surface tension method, and the results showed that it had high surface activity with CMC of 5.53 × 10−5 mol/L. The surfactant was superior in surface active properties to the reference surfactants SDBS and DADS‐C12. The interfacial tension (IFT) of the studied crude oil–water system (surfactant concentration 0.1 g/L, NaOH concentration 0.5 g/L, and experimental temperature 50 °C) dropped to 1.1 × 10−4 mN/m, which can fulfil the requirement of surfactants for oil displacement. An aqueous solution of the surfactant and crude oil was emulsified by shaking, which formed a highly stable oil‐in‐water (O/W) emulsion with particle size of 5–20 μm. The oil displacement effect was almost 12%.
Experimental investigation of foam performance in the presence of crude oil
Authors: Pu Wanfen , Pang Shishi , Wang Chongyang
Published: June 2017

The foam performance in the presence of oil plays an important role in foam application in enhancing oil recovery. The present study systematically investigated the effect of oil type, oil content, surfactant type, surfactant concentration, alkane chain length, salinity, and polymer concentration on foam performance in both the absence and presence of oil. The results showed that oil viscosity and oil density as well as oil component all contributed to foam performance in the presence of oil. Within a certain oil content, both light oil and heavy oil had a positive effect on foam, but heavy oil had a higher tendency to stabilize the foam. The order of foam performance by different surfactants was changed by the oil. It is noteworthy that heavy oil is detrimental to sodium dibutyl naphthalene sulfonate (BM) foam. Light oil can improve foam performance while heavy oil can harm foam in some specific cases. Lower salinity, longer alkane chain length, higher surfactant concentration and the presence of a polymer all benefited foam in the presence of crude oil.
Ledgers, Anecdotes and Leadership: Guidelines for Partnering with the New Us President
Authors: Shepura Nathan
Published: June 2017

President Trump's foreign policy remains paradoxical and as yet highly uncertain. European leaders face the challenge of communicating both their interests and values in ways that the new president will welcome. Thus far, practical discussion combined with a personal connection seems the likeliest path to success. Ultimately, the EU has the opportunity not only to partner with the US but to lead the way forward based on the EU's own fundamental commitments and values. Three important areas this could affect are security and defence, climate change policy and global trade.
Patient-Centered Outcomes and Treatment Preferences Regarding Sexual Problems: A Qualitative Study Among Midlife Women
Authors: Thomas Holly N. , Hamm Megan , Hess Rachel , Borrero Sonya , Thurston Rebecca C.
Published: June 2017

Background

Sexual dysfunction is common in midlife women and can have a significant negative impact on quality of life. Although treatments exist, there is little research on which sexual function outcomes and treatments midlife women prefer.

Aim

To better understand the sexual function outcomes that were most important to sexually active women 45 to 60 years old and the types of treatments they would prefer from individual interviews and focus groups.

Methods

Twenty individual interviews and three focus groups (N = 39) were led by a trained facilitator, audio recorded, and transcribed. Two investigators developed a codebook, and the primary investigator coded all data. A second investigator coded five randomly selected interviews to ensure intercoder reliability. Codes relating to outcomes and treatment preferences were examined to identify central themes.

Results

The mean age was 52.8 years (range = 45–59). When asked what they would want a sexual dysfunction treatment to do, women sought solutions to specific sexual problems: low desire, vaginal pain and dryness, and decreased arousal or ability to achieve orgasm. However, when asked about the most important aspect of their sex life, most women indicated emotional outcomes, such as enhanced intimacy with their partner, were most important to them. Most women preferred behavioral over pharmaceutical treatments, citing concerns about side effects. These women felt that behavioral treatments might be better equipped to address physical and psychological aspects of sexual problems.

Clinical implications

This study highlights the importance of considering not only physical but also emotional outcomes when evaluating and treating sexual dysfunction in midlife women. It also emphasizes the importance of developing behavioral treatments in addition to pharmaceutical treatments.

Strengths and Limitations

By using a qualitative approach, this study allowed women the time and space to speak their own words about their experiences with sexuality at midlife. In addition, different racial and ethnic groups and menopausal statuses were represented. Limitations include limited generalizability, as is true for most qualitative research. In addition, although most women did endorse sexual problems, we did not exclude women with no sexual complaints.

Conclusions

Midlife women value physical and emotional outcomes with regard to sexual function. Many midlife women in this sample expressed a preference for behavioral approaches over pharmaceutical approaches for the treatment of sexual dysfunction.
Conceptual design of a 15-TW pulsed-power accelerator for high-energy-density—physics experiments
Authors: Spielman R.B. , Froula D.H. , Brent G. , Campbell E.M. , Reisman D.B. , Savage M.E. , Shoup M.J. , Stygar W.A. , Wisher M.L.
Published: June 2017

We have developed a conceptual design of a 15-TW pulsed-power accelerator based on the linear-transformer-driver (LTD) architecture described by Stygar [W. A. Stygar et al., Phys. Rev. ST Accel. Beams 18, 110401 (2015)]. The driver will allow multiple, high-energy-density experiments per day in a university environment and, at the same time, will enable both fundamental and integrated experiments that are scalable to larger facilities. In this design, many individual energy storage units (bricks), each composed of two capacitors and one switch, directly drive the target load without additional pulse compression. Ten LTD modules in parallel drive the load. Each module consists of 16 LTD cavities connected in series, where each cavity is powered by 22 bricks connected in parallel. This design stores up to 2.75 MJ and delivers up to 15 TW in 100 ns to the constant-impedance, water-insulated radial transmission lines. The transmission lines in turn deliver a peak current as high as 12.5 MA to the physics load. To maximize its experimental value and flexibility, the accelerator is coupled to a modern, multibeam laser facility (four beams with up to 5 kJ in 10 ns and one beam with up to 2.6 kJ in 100 ps or less) that can provide auxiliary heating of the physics load. The lasers also enable advanced diagnostic techniques such as X-ray Thomson scattering and multiframe and three-dimensional radiography. The coupled accelerator-laser facility will be the first of its kind and be capable of conducting unprecedented high-energy-density–physics experiments.
Anatomic measures of upper airway structures in obstructive sleep apnea
Authors: Barrera Jose E. , Pau Candace Y. , Forest Veronique‐Isabelle , Holbrook Andrew B. , Popelka Gerald R.
Published: June 2017

Objective

Determine if anatomic dimensions of airway structures are associated with airway obstruction in obstructive sleep apnea (OSA) patients.

Methods

Twenty‐eight subjects with (n = 14) and without (n = 14) OSA as determined by clinical symptoms and sleep studies; volunteer sample. Skeletal and soft tissue dimensions were measured from radiocephalometry and magnetic resonance imaging. The soft palate thickness, mandibular plane‐hyoid (MP‐H) distance, posterior airway space (PAS) diameters and area, and tongue volume were calculated.

Results

Compared to controls, the OSA group demonstrated a significantly longer MP‐H distance (P = 0.009) and shorter nasal PAS diameter (P = 0.02). The PAS area was smaller (P = 0.002) and tongue volume larger in the OSA group (P = 0.004). The MP‐H distance, PAS measurements, and tongue volume are of clinical relevance in OSA patients.

Conclusions

A long MP‐H distance, and small PAS diameters and area are significant anatomic measures in OSA; however the most substantial parameter found was a large tongue volume.
On the last exit times for spectrally negative Lévy processes
Authors: Li Yingqiu , Yin Chuancun , Zhou Xiaowen
Published: June 2017

Using a new approach, for spectrally negative Lévy processes we find joint Laplace transforms involving the last exit time (from a semiinfinite interval), the value of the process at the last exit time, and the associated occupation time, which generalize some previous results.
Moderate deviation principles for importance sampling estimators of risk measures
Authors: Nyquist Pierre
Published: June 2017

Importance sampling has become an important tool for the computation of extreme quantiles and tail-based risk measures. For estimation of such nonlinear functionals of the underlying distribution, the standard efficiency analysis is not necessarily applicable. In this paper we therefore study importance sampling algorithms by considering moderate deviations of the associated weighted empirical processes. Using a delta method for large deviations, combined with classical large deviation techniques, the moderate deviation principle is obtained for importance sampling estimators of two of the most common risk measures: value at risk and expected shortfall.
A unified approach for drawdown (drawup) of time-homogeneous Markov processes
Authors: Landriault David , Li Bin , Zhang Hongzhong
Published: June 2017

Drawdown (respectively, drawup) of a stochastic process, also referred as the reflected process at its supremum (respectively, infimum), has wide applications in many areas including financial risk management, actuarial mathematics, and statistics. In this paper, for general time-homogeneous Markov processes, we study the joint law of the first passage time of the drawdown (respectively, drawup) process, its overshoot, and the maximum of the underlying process at this first passage time. By using short-time pathwise analysis, under some mild regularity conditions, the joint law of the three drawdown quantities is shown to be the unique solution to an integral equation which is expressed in terms of fundamental two-sided exit quantities of the underlying process. Explicit forms for this joint law are found when the Markov process has only one-sided jumps or is a Lévy process (possibly with two-sided jumps). The proposed methodology provides a unified approach to study various drawdown quantities for the general class of time-homogeneous Markov processes.
Some properties of the cumulative residual entropy of coherent and mixed systems
Authors: Toomaj A. , Sunoj S. M. , Navarro J.
Published: June 2017

Recently, Rao et al. (2004) introduced an alternative measure of uncertainty known as the cumulative residual entropy (CRE). It is based on the survival (reliability) function F̅ instead of the probability density function f used in classical Shannon entropy. In reliability based system design, the performance characteristics of the coherent systems are of great importance. Accordingly, in this paper, we study the CRE for coherent and mixed systems when the component lifetimes are identically distributed. Bounds for the CRE of the system lifetime are obtained. We use these results to propose a measure to study if a system is close to series and parallel systems of the same size. Our results suggest that the CRE can be viewed as an alternative entropy (dispersion) measure to classical Shannon entropy.
Minimising generation of acid whey during Greek yoghurt manufacturing
Authors: Uduwerella Gangani , Chandrapala Jayani , Vasiljevic Todor
Published: June 2017

Greek yoghurt, a popular dairy product, generates large amounts of acid whey as a by-product during manufacturing. Post-processing treatment of this stream presents one of the main concerns for the industry. The objective of this study was to manipulate initial milk total solids content (15, 20 or 23 g/100 g) by addition of milk protein concentrate, thus reducing whey expulsion. Such an adjustment was investigated from the technological standpoint including starter culture performance, chemical and physical properties of manufactured Greek yoghurt and generated acid whey. A comparison was made to commercially available products. Increasing protein content in regular yoghurt reduced the amount of acid whey during whey draining. This protein fortification also enhanced the Lb. bulgaricus growth rate and proteolytic activity. Best structural properties including higher gel strength and lower syneresis were observed in the Greek yoghurt produced with 20 g/100 g initial milk total solid compared to manufactured or commercially available products, while acid whey generation was lowered due to lower drainage requirement.
Characterization of the complete mitochondrial genome ofOrtleppascaris sinensis(Nematoda: Heterocheilidae) and comparative mitogenomic analysis of eighteen Ascaridida nematodes
Authors: Zhao J.H. , Tu G.J. , Wu X.B. , Li C.P.
Published: June 2017

Ortleppascaris sinensis(Nematoda: Ascaridida) is a dominant intestinal nematode of the captive Chinese alligator. However, the epidemiology, molecular ecology and population genetics of this parasite remain largely unexplored. In this study, the complete mitochondrial (mt) genome sequence ofO. sinensiswas first determined using a polymerase chain reaction (PCR)-based primer-walking strategy, and this is also the first sequencing of the complete mitochondrial genome of a member of the genusOrtleppascaris. The circular mitochondrial genome (13,828 bp) ofO. sinensiscontained 12 protein-coding, 22 transfer RNA and 2 ribosomal RNA genes, but lacked the ATP synthetase subunit 8 gene. Finally, phylogenetic analysis of mtDNAs indicated that the genusOrtleppascarisshould be attributed to the family Heterocheilidae. It is necessary to sequence more mtNDAs ofOrtleppascarisnematodes in the future to test and confirm our conclusion. The complete mitochondrial genome sequence ofO. sinensisreported here should contribute to molecular diagnosis, epidemiological investigations and ecological studies ofO. sinensisand other related Ascaridida nematodes.
Rodents, goats and dogs – their potential roles in the transmission of schistosomiasis in China
Authors: VAN DORSSEN CLARE F. , GORDON CATHERINE A. , LI YUESHENG , WILLIAMS GAIL M. , WANG YUANYUAN , LUO ZHENHUA , GOBERT GEOFFREY N. , YOU HONG , MCMANUS DONALD P. , GRAY DARREN J.
Published: June 2017

Schistosomiasis in China has been substantially reduced due to an effective control programme employing various measures including bovine and human chemotherapy, and the removal of bovines from endemic areas. To fulfil elimination targets, it will be necessary to identify other possible reservoir hosts forSchistosoma japonicumand include them in future control efforts. This study determined the infection prevalence ofS. japonicumin rodents (0–9·21%), dogs (0–18·37%) and goats (6·9–46·4%) from the Dongting Lake area of Hunan province, using a combination of traditional coproparasitological techniques (miracidial hatching technique and Kato-Katz thick smear technique) and molecular methods [quantitative real-time PCR (qPCR) and droplet digital PCR (ddPCR)]. We found a much higher prevalence in goats than previously recorded in this setting. Cattle and water buffalo were also examined using the same procedures and all were found to be infected, emphasising the occurrence of active transmission. qPCR and ddPCR were much more sensitive than the coproparasitological procedures with both KK and MHT considerably underestimating the true prevalence in all animals surveyed. The high level ofS. japonicumprevalence in goats indicates that they are likely important reservoirs in schistosomiasis transmission, necessitating their inclusion as targets of control, if the goal of elimination is to be achieved in China.
A new look at the supposed risks of early institutional rearing
Authors: Woodhouse S. , Miah A. , Rutter M.
Published: June 2017

The main focus is on the assessment of the effects of early institutional care and compares three longitudinal studies from Romania, Greece and Hong Kong/China. The findings have been strikingly contrasting. The review asks if the risks are dependent on whether or not the institutional rearing is accompanied by gross pervasive deprivation (as it was in Romania) and investigates the methodological issues to explore the causal influence of the outcomes. Evidence is considered on changing institutional practices and the benefits of doing so. Comparison is made between institutions with major deprivation and those without global deprivation. A small number of studies are discussed that look at direct comparisons between institutional and community care. The empirical and conceptual implications of the findings are discussed.
Lower Bounds on DOP
Authors: Swaszek Peter F. , Hartnett Richard J. , Seals Kelly C.
Published: June 2017

Code phase Global Navigation Satellite System (GNSS) positioning performance is often described by the Geometric or Position Dilution of Precision (GDOP or PDOP), functions of the number of satellites employed in the solution and their geometry. This paper develops lower bounds to both metrics solely as functions of the number of satellites, effectively removing the added complexity caused by their locations in the sky, to allow users to assess how well their receivers are performing with respect to the best possible performance. Such bounds will be useful as receivers sub-select from the plethora of satellites available with multiple GNSS constellations. The bounds are initially developed for one constellation assuming that the satellites are at or above the horizon. Satellite constellations that essentially achieve the bounds are discussed, again with value toward the problem of satellite selection. The bounds are then extended to a non-zero mask angle and to multiple constellations.
Climate and Other Models May Be More Accurate Than Reported
Authors: Willmott Cort , Robeson Scott , Matsuura Kenji
Published: June 2017

Replacing a commonly used statistical measure of average error with an alternative measure would give a more meaningful assessment of model performance.
Growing More with Less Using Cell Phones and Satellite Data
Authors: Hossain Faisal , Biswas Nishan , Ashraf Muhammad , Bhatti Ahmad
Published: June 2017

Researchers from the University of Washington and Pakistan are using 21st century technology to revive farming as a profitable profession in the Indus Valley.
A role for TSPO in mitochondrial Ca2+ homeostasis and redox stress signaling
Authors: Gatliff Jemma , East Daniel A , Singh Aarti , Alvarez Maria Soledad , Frison Michele , Matic Ivana , Ferraina Caterina , Sampson Natalie , Turkheimer Federico , Campanella Michelangelo
Published: June 2017

The 18 kDa translocator protein TSPO localizes on the outer mitochondrial membrane (OMM). Systematically overexpressed at sites of neuroinflammation it is adopted as a biomarker of brain conditions. TSPO inhibits the autophagic removal of mitochondria by limiting PARK2-mediated mitochondrial ubiquitination via a peri-organelle accumulation of reactive oxygen species (ROS). Here we describe that TSPO deregulates mitochondrial Ca2+ signaling leading to a parallel increase in the cytosolic Ca2+ pools that activate the Ca2+-dependent NADPH oxidase (NOX) thereby increasing ROS. The inhibition of mitochondrial Ca2+ uptake by TSPO is a consequence of the phosphorylation of the voltage-dependent anion channel (VDAC1) by the protein kinase A (PKA), which is recruited to the mitochondria, in complex with the Acyl-CoA binding domain containing 3 (ACBD3). Notably, the neurotransmitter glutamate, which contributes neuronal toxicity in age-dependent conditions, triggers this TSPO-dependent mechanism of cell signaling leading to cellular demise. TSPO is therefore proposed as a novel OMM-based pathway to control intracellular Ca2+ dynamics and redox transients in neuronal cytotoxicity.
AQP9-induced cell cycle arrest is associated with RAS activation and improves chemotherapy treatment efficacy in colorectal cancer
Authors: Huang Dandan , Feng Xingzhi , Liu Yiting , Deng Yanhong , Chen Hao , Chen Daici , Fang Lekun , Cai Yue , Liu Huanliang , Wang Lei , Wang Jianping , Yang Zihuan
Published: June 2017

Aquaporin-9 (AQP9) expression is associated with arsenic sensitivity in leukemia cells. However, the role of AQP9 in regulating tumor sensitivity to adjuvant chemotherapy in colorectal cancer (CRC) has not been elucidated. In this study, we demonstrated that AQP9 can serve as an independent predictive marker for adjuvant chemotherapy in CRC. Patients with high AQP9 expression had higher rate of disease-free survival (DFS) than those with low AQP9 expression. Upregulation of AQP9 was associated with enhanced chemosensitivity to 5-fluorouracil (5-FU) both in vitro and in vivo. Overexpression of AQP9 resulted in an increased intracellular level of 5-FU in CRC cells, hence leading to a higher percentage of apoptosis after 5-FU treatment. Moreover, AQP9 is positively associated with RAS activation and other downstream signaling molecules in CRC. AQP9 overexpression resulted in p21 upregulation and induced S-phase arrest. Taken together, AQP9 enhances the cytotoxic response to 5-FU in CRC cells by simultaneously inducing S-phase arrest via activation of RAS signaling and facilitating drug uptake. Our results suggest that AQP9 might be a novel predictor for the benefit of 5-FU-based chemotherapy in CRC. The identification of AQP9-induced tumor sensitivity to 5-FU highlights the role of AQP9 in regulating chemosensitivity in CRC.
MicroRNA-34a dependent regulation of AXL controls the activation of dendritic cells in inflammatory arthritis
Authors: Kurowska-Stolarska Mariola , Alivernini Stefano , Melchor Emma Garcia , Elmesmari Aziza , Tolusso Barbara , Tange Clare , Petricca Luca , Gilchrist Derek S. , Di Sante Gabriele , Keijzer Chantal , Stewart Lynn , Di Mario Clara , Morrison Vicky , Brewer James M. , Porter Duncan , Milling Simon , Baxter Ronald D. , McCarey David , Gremese Elisa , Lemke Greg , Ferraccioli Gianfranco , McSharry Charles , McInnes Iain B.
Published: June 2017

Current treatments for rheumatoid arthritis (RA) do not reverse underlying aberrant immune function. A genetic predisposition to RA, such as HLA-DR4 positivity, indicates that dendritic cells (DC) are of crucial importance to pathogenesis by activating auto-reactive lymphocytes. Here we show that microRNA-34a provides homoeostatic control of CD1c+ DC activation via regulation of tyrosine kinase receptor AXL, an important inhibitory DC auto-regulator. This pathway is aberrant in CD1c+ DCs from patients with RA, with upregulation of miR-34a and lower levels of AXL compared to DC from healthy donors. Production of pro-inflammatory cytokines is reduced by ex vivo gene-silencing of miR-34a. miR-34a-deficient mice are resistant to collagen-induced arthritis and interaction of DCs and T cells from these mice are reduced and do not support the development of Th17 cells in vivo. Our findings therefore show that miR-34a is an epigenetic regulator of DC function that may contribute to RA.
Growth-coupled overproduction is feasible for almost all metabolites in five major production organisms
Authors: von Kamp Axel , Klamt Steffen
Published: June 2017

Computational modelling of metabolic networks has become an established procedure in the metabolic engineering of production strains. One key principle that is frequently used to guide the rational design of microbial cell factories is the stoichiometric coupling of growth and product synthesis, which makes production of the desired compound obligatory for growth. Here we show that the coupling of growth and production is feasible under appropriate conditions for almost all metabolites in genome-scale metabolic models of five major production organisms. These organisms comprise eukaryotes and prokaryotes as well as heterotrophic and photoautotrophic organisms, which shows that growth coupling as a strain design principle has a wide applicability. The feasibility of coupling is proven by calculating appropriate reaction knockouts, which enforce the coupling behaviour. The study presented here is the most comprehensive computational investigation of growth-coupled production so far and its results are of fundamental importance for rational metabolic engineering.
Erratum: The gut microbiota: a major player in the toxicity of environmental pollutants?
Authors: Claus Sandrine P , Guillou Hervé , Ellero-Simatos Sandrine
Published: June 2017

Correction to: npj Biofilms and Microbiomes (2016) 2, 16003; doi: http://dx.doi.org/10.1038/npjbiofilms.2016.3; published online 4 May 2016 In the Supplementary Information File originally published with this Article, the tracked changes were visible within the document. This error has now been corrected in the Supplementary Information that now accompanies the Article.
CIB2 interacts with TMC1 and TMC2 and is essential for mechanotransduction in auditory hair cells
Authors: Giese Arnaud P. J. , Tang Yi-Quan , Sinha Ghanshyam P. , Bowl Michael R. , Goldring Adam C. , Parker Andrew , Freeman Mary J. , Brown Steve D. M. , Riazuddin Saima , Fettiplace Robert , Schafer William R. , Frolenkov Gregory I. , Ahmed Zubair M.
Published: June 2017

Inner ear hair cells detect sound through deflection of stereocilia, the microvilli-like projections that are arranged in rows of graded heights. Calcium and integrin-binding protein 2 is essential for hearing and localizes to stereocilia, but its exact function is unknown. Here, we have characterized two mutant mouse lines, one lacking calcium and integrin-binding protein 2 and one carrying a human deafness-related Cib2 mutation, and show that both are deaf and exhibit no mechanotransduction in auditory hair cells, despite the presence of tip links that gate the mechanotransducer channels. In addition, mechanotransducing shorter row stereocilia overgrow in hair cell bundles of both Cib2 mutants. Furthermore, we report that calcium and integrin-binding protein 2 binds to the components of the hair cell mechanotransduction complex, TMC1 and TMC2, and these interactions are disrupted by deafness-causing Cib2 mutations. We conclude that calcium and integrin-binding protein 2 is required for normal operation of the mechanotransducer channels and is involved in limiting the growth of transducing stereocilia.
Functional and dynamic polymerization of the ALS-linked protein TDP-43 antagonizes its pathologic aggregation
Authors: Afroz Tariq , Hock Eva-Maria , Ernst Patrick , Foglieni Chiara , Jambeau Melanie , Gilhespy Larissa A. B. , Laferriere Florent , Maniecka Zuzanna , Plückthun Andreas , Mittl Peer , Paganetti Paolo , Allain Frédéric H. T. , Polymenidou Magdalini
Published: June 2017

TDP-43 is a primarily nuclear RNA-binding protein, whose abnormal phosphorylation and cytoplasmic aggregation characterizes affected neurons in patients with amyotrophic lateral sclerosis and frontotemporal dementia. Here, we report that physiological nuclear TDP-43 in mouse and human brain forms homo-oligomers that are resistant to cellular stress. Physiological TDP-43 oligomerization is mediated by its N-terminal domain, which can adopt dynamic, solenoid-like structures, as revealed by a 2.1 Å crystal structure in combination with nuclear magnetic resonance spectroscopy and electron microscopy. These head-to-tail TDP-43 oligomers are unique among known RNA-binding proteins and represent the functional form of the protein in vivo, since their destabilization results in loss of alternative splicing regulation of known neuronal RNA targets. Our findings indicate that N-terminal domain-driven oligomerization spatially separates the adjoining highly aggregation-prone, C-terminal low-complexity domains of consecutive TDP-43 monomers, thereby preventing low-complexity domain inter-molecular interactions and antagonizing the formation of pathologic aggregates.