bluuebunny/crossref_metadata_2025 huggingface dataset:
Fault Diagnosis of Distributed Parameter Systems Modeled by Linear Parabolic Partial Differential Equations With State Faults
Authors: Ferdowsi Hasan , Jagannathan S.
Published: July 2017

In this paper, the problem of fault diagnosis in distributed parameter systems (DPS) is investigated. The behavior of DPS is best described by partial differential equation (PDE) models. In contrast to transforming the DPS into a finite set of ordinary differential equations (ODE) prior to the design of control or fault detection schemes by using significant approximations, thus reducing the accuracy and reliability of the overall system, in this paper, the PDE representation of the system is directly utilized to construct a fault detection observer. A fault is detected by comparing the detection residual, which is the difference between measured and estimated outputs, with a predefined detection threshold. Once the fault is detected, an adaptive approximator is activated to learn the fault function. The estimated fault parameters are then compared with their failure thresholds to provide an estimate of the remaining useful life of the system. The scheme is verified in simulations on a heat system which is described by parabolic PDEs.
Tribological Performance of MoS2-Filled Microtextured Cutting Tools During Dry Sliding Test
Authors: Gajrani Kishor Kumar , Sankar Mamilla Ravi , Dixit Uday Shanker
Published: July 2017

Strict environmental laws enforced on manufacturing industries resulted in the development of alternative techniques to reduce or eliminate the use of lubricants during sliding contact as well as machining. Tribology plays a very important role for tool life in machining. To improve the life of cutting tool, cutting fluids are used. However, cutting fluids only penetrate into the region of sliding contact. In this study, the effect of surface texturing on plasma nitrided high-speed steel (HSS) pins during dry sliding test is investigated for understanding the performance of textured HSS tools in machining. Microtextures were fabricated using Vickers hardness tester on the surface of HSS pins. Tribological tests of molybdenum disulphide (MoS2) filled as well as unfilled microtextured HSS with area density of textures varying from 2% to 14% were performed with the aid of pin-on-disk tribometer against an abrasive sheet. Friction and wear performance were assessed in terms of the pin surface temperature, coefficient of friction (COF), wear, weight loss of the pin and wear rate. Worn-out test surfaces were observed under scanning electron microscope to understand the wear mechanism. The best results were obtained with MoS2-filled microtextures having 10% texture area density. Tool–chip interface temperature, cutting force, feed force, and centerline average (CLA) surface roughness were also assessed during machining test with 10% area density of textured cutting tools.
Wear Behavior of Rotary Lip Seal Operating in a Magnetorheological Fluid Under Magnetic Field Conditions
Authors: Zhang Peng , Lee Kwang-Hee , Lee Chul-Hee
Published: July 2017

A magnetorheological fluid (MRF) is one of many smart materials that can be changed their rheological properties. The stiffness and damping characteristics of MRF can be changed when a magnetic field is applied. This technology has been successfully employed in various low and high volume applications, such as dampers, clutches, and active bearings, which are already in the market or are approaching production. As a result, the sealing performance of MRF has become increasingly important. In this study, the wear properties of seals with MRFs were evaluated by a rotary-type lip seal wear tester. The test was performed with and without a magnetic field. The leakage time was monitored during the tests in typical engine oil conditions. The results showed that the wear resistance of the seal with MRF was decreased under the magnetic field.
Mechanoresponsive stem cells to target cancer metastases through biophysical cues
Authors: Liu Linan , Zhang Shirley X. , Liao Wenbin , Farhoodi Henry P. , Wong Chi W. , Chen Claire C. , Ségaliny Aude I. , Chacko Jenu V. , Nguyen Lily P. , Lu Mengrou , Polovin George , Pone Egest J. , Downing Timothy L. , Lawson Devon A. , Digman Michelle A. , Zhao Weian
Published: July 2017

Targeting the mechano-niche of the tumor microenvironment is a strategy to interrogate, detect, and treat cancer.
Charting the “unknown unknowns” of cancer progression
Authors: Goodarzi Hani
Published: July 2017

Integrated computational and experimental strategies reveal previously unknown regulatory programs underlying metastatic disease.
Hold your nose to get lean
Authors: Morris Jill K.
Published: July 2017

Decreased olfactory function is associated with lean phenotype, improved peripheral metabolism, and increased energy expenditure during a high-fat diet.
Prevention of Ophthalmia Neonatorum Caused by
Neisseria gonorrhoeae
Using a Fatty Acid-Based Formulation
Authors: Churchward Colin P. , Alany Raid G. , Kirk Ruth S. , Walker Anthony J. , Snyder Lori A. S.
Published: July 2017

Ophthalmia neonatorum, also called neonatal conjunctivitis, acquired during delivery can occur in the first 28 days of life. Commonly caused by the bacterial pathogen
Neisseria gonorrhoeae
, infection can lead to corneal scarring, perforation of the eye, and blindness. One approach that can be taken to prevent the disease is the use of an ophthalmic prophylaxis, which kills the bacteria on the surface of the eye shortly after birth. Current prophylaxes are based on antibiotic ointments. However,
N. gonorrhoeae
is resistant to many antibiotics and alternative treatments must be developed before the condition becomes untreatable. This study focused on developing a fatty acid-based prophylaxis. For this, 37 fatty acids or fatty acid derivatives were screened
in vitro
for fast antigonococcal activity. Seven candidates were identified as bactericidal at 1 mM. These seven were subjected to irritation testing using three separate methods: the bovine corneal opacity and permeability (BCOP) test; the hen’s egg test—chorioallantoic membrane (HET-CAM); and the red blood cell (RBC) lysis assay. The candidates were also tested in artificial tear fluid to determine whether they were effective in this environment. Four of the candidates remained effective. Among these, two lead candidates, monocaprin and myristoleic acid, displayed the best potential as active compounds in the development of a fatty acid-based prophylaxis for prevention of ophthalmia neonatorum.
Structural and
In Vivo
Studies on Trehalose-6-Phosphate Synthase from Pathogenic Fungi Provide Insights into Its Catalytic Mechanism, Biological Necessity, and Potential for Novel Antifungal Drug Design
Authors: Miao Yi , Tenor Jennifer L. , Toffaletti Dena L. , Maskarinec Stacey A. , Liu Jiuyu , Lee Richard E. , Perfect John R. , Brennan Richard G.
Published: July 2017

The disaccharide trehalose is critical to the survival of pathogenic fungi in their human host. Trehalose-6-phosphate synthase (Tps1) catalyzes the first step of trehalose biosynthesis in fungi. Here, we report the first structures of eukaryotic Tps1s in complex with substrates or substrate analogues. The overall structures of Tps1 from
Candida albicans
and
Aspergillus fumigatus
are essentially identical and reveal N- and C-terminal Rossmann fold domains that form the glucose-6-phosphate and UDP-glucose substrate binding sites, respectively. These Tps1 structures with substrates or substrate analogues reveal key residues involved in recognition and catalysis. Disruption of these key residues severely impaired Tps1 enzymatic activity. Subsequent cellular analyses also highlight the enzymatic function of Tps1 in thermotolerance, yeast-hypha transition, and biofilm development. These results suggest that Tps1 enzymatic functionality is essential for the fungal stress response and virulence. Furthermore, structures of Tps1 in complex with the nonhydrolyzable inhibitor, validoxylamine A, visualize the transition state and support an internal return-like catalytic mechanism that is generalizable to other GT-B-fold retaining glycosyltransferases. Collectively, our results depict key Tps1-substrate interactions, unveil the enzymatic mechanism of these fungal proteins, and pave the way for high-throughput inhibitor screening buttressed and guided by the current structures and those of high-affinity ligand-Tps1 complexes.

IMPORTANCE
Invasive fungal diseases have emerged as major threats, resulting in more than 1.5 million deaths annually worldwide. This epidemic has been further complicated by increasing resistance to all major classes of antifungal drugs in the clinic. Trehalose biosynthesis is essential for the fungal stress response and virulence. Critically, this biosynthetic pathway is absent in mammals, and thus, the two enzymes that carry out trehalose biosynthesis, namely, trehalose-6-phosphate synthase (Tps1) and trehalose-6-phosphate phosphatase (Tps2), are prominent targets for antifungal intervention. Here, we report the first eukaryotic Tps1 structures from the pathogenic fungi
Candida albicans
and
Aspergillus fumigatus
in complex with substrates, substrate analogues, and inhibitors. These structures reveal key protein-substrate interactions, providing atomic-level scaffolds for structure-guided drug design of novel antifungals that target Tps1.
Bacterial Signaling Nucleotides Inhibit Yeast Cell Growth by Impacting Mitochondrial and Other Specifically Eukaryotic Functions
Authors: Hesketh Andy , Vergnano Marta , Wan Chris , Oliver Stephen G.
Published: July 2017

We have engineered
Saccharomyces cerevisiae
to inducibly synthesize the prokaryotic signaling nucleotides cyclic di-GMP (cdiGMP), cdiAMP, and ppGpp in order to characterize the range of effects these nucleotides exert on eukaryotic cell function during bacterial pathogenesis. Synthetic genetic array (SGA) and transcriptome analyses indicated that, while these compounds elicit some common reactions in yeast, there are also complex and distinctive responses to each of the three nucleotides. All three are capable of inhibiting eukaryotic cell growth, with the guanine nucleotides exhibiting stronger effects than cdiAMP. Mutations compromising mitochondrial function and chromatin remodeling show negative epistatic interactions with all three nucleotides. In contrast, certain mutations that cause defects in chromatin modification and ribosomal protein function show positive epistasis, alleviating growth inhibition by at least two of the three nucleotides. Uniquely, cdiGMP is lethal both to cells growing by respiration on acetate and to obligately fermentative petite mutants. cdiGMP is also synthetically lethal with the ribonucleotide reductase (RNR) inhibitor hydroxyurea. Heterologous expression of the human ppGpp hydrolase Mesh1p prevented the accumulation of ppGpp in the engineered yeast and restored cell growth. Extensive
in vivo
interactions between bacterial signaling molecules and eukaryotic gene function occur, resulting in outcomes ranging from growth inhibition to death. cdiGMP functions through a mechanism that must be compensated by unhindered RNR activity or by functionally competent mitochondria. Mesh1p may be required for abrogating the damaging effects of ppGpp in human cells subjected to bacterial infection.

IMPORTANCE
During infections, pathogenic bacteria can release nucleotides into the cells of their eukaryotic hosts. These nucleotides are recognized as signals that contribute to the initiation of defensive immune responses that help the infected cells recover. Despite the importance of this process, the broader impact of bacterial nucleotides on the functioning of eukaryotic cells remains poorly defined. To address this, we genetically modified cells of the eukaryote
Saccharomyces cerevisiae
(baker’s yeast) to produce three of these molecules (cdiAMP, cdiGMP, and ppGpp) and used the engineered strains as model systems to characterize the effects of the molecules on the cells. In addition to demonstrating that the nucleotides are each capable of adversely affecting yeast cell function and growth, we also identified the cellular functions important for mitigating the damage caused, suggesting possible modes of action. This study expands our understanding of the molecular interactions that can take place between bacterial and eukaryotic cells.
Positive Autoregulation of an Acyl-Homoserine Lactone Quorum-Sensing Circuit Synchronizes the Population Response
Authors: Scholz Rebecca L. , Greenberg E. Peter
Published: July 2017

Many proteobacteria utilize acyl-homoserine lactone quorum-sensing signals. At low population densities, cells produce a basal level of signal, and when sufficient signal has accumulated in the surrounding environment, it binds to its receptor, and quorum-sensing-dependent genes can be activated. A common characteristic of acyl-homoserine lactone quorum sensing is that signal production is positively autoregulated. We have examined the role of positive signal autoregulation in
Pseudomonas aeruginosa
. We compared population responses and individual cell responses in populations of wild-type
P. aeruginosa
to responses in a strain with the signal synthase gene controlled by an arabinose-inducible promoter so that signal was produced at a constant rate per cell regardless of cell population density. At a population level, responses of the wild type and the engineered strain were indistinguishable, but the responses of individual cells in a population of the wild type showed greater synchrony than the responses of the engineered strain. Although sufficient signal is required to activate expression of quorum-sensing-regulated genes, it is not sufficient for activation of certain genes, the late genes, and their expression is delayed until other conditions are met. We found that late gene responses were reduced in the engineered strain. We conclude that positive signal autoregulation is not a required element in acyl-homoserine lactone quorum sensing, but it functions to enhance synchrony of the responses of individuals in a population. Synchrony might be advantageous in some situations, whereas a less coordinated quorum-sensing response might allow bet hedging and be advantageous in other situations.

IMPORTANCE
There are many quorum-sensing systems that involve a transcriptional activator, which responds to an acyl-homoserine lactone signal. In all of the examples studied, the gene coding for signal production is positively autoregulated by the signal, and it has even been described as essential for a quorum-sensing response. We have used the opportunistic pathogen
Pseudomonas aeruginosa
as a model to show that positive autoregulation is not required for a robust quorum-sensing response. We also show that positive autoregulation of signal production enhances the synchrony of the response. This information enhances our general understanding of the biological significance of how acyl-homoserine lactone quorum-sensing circuits are arranged.
Can’t see the woods for the trees: exploring the range and connection of tobacco industry argumentation in the 2012 UK standardised packaging consultation
Authors: Lie Jessamina Lih Yan , Fooks Gary , de Vries Nanne K , Heijndijk Suzanne M , Willemsen Marc C
Published: July 2017

Introduction

Transnational tobacco company (TTC) submissions to the 2012 UK standardised packaging consultation are studied to examine TTC argumentation in the context of Better Regulation practices.

Methods

A content analysis was conducted of Philip Morris International and British American Tobacco submissions to the 2012 UK consultation. Industry arguments concerning expected costs and (contested) benefits of the policy were categorised into themes and frames. The inter-relationship between frames through linked arguments was mapped to analyse central arguments using an argumentation network.

Results

173 arguments were identified. Arguments fell into one of five frames: ineffectiveness, negative economic consequences, harm to public health, increased crime or legal ramifications. Arguments highlighted high costs to a wide range of groups, including government, general public and other businesses. Arguments also questioned the public health benefits of standardised packaging and highlighted the potential benefits to undeserving groups. An increase in illicit trade was the most central argument and linked to the greatest variety of arguments.

Conclusions

In policy-making systems characterised by mandatory impact assessments and public consultations, the wide range of cost (and contested benefits) based arguments highlights the risk of TTCs overloading policy actors and causing delays in policy adoption. Illicit trade related arguments are central to providing a rationale for these arguments, which include the claim that standardised packaging will increase health risks. The strategic importance of illicit trade arguments to industry argumentation in public consultations underlines the risks of relying on industry data relating to the scale of the illicit trade.
Feeding ecology and niche overlap of Lake Ontario offshore forage fish assessed with stable isotopes
Authors: Mumby James A. , Johnson Timothy B. , Stewart Thomas J. , Halfyard Edmund A. , Weidel Brian C. , Walsh Maureen G. , Lantry Jana R. , Fisk Aaron T.
Published: July 2017

The forage fish communities of the Laurentian Great Lakes continue to experience changes that have altered ecosystem structure, yet little is known about how they partition resources. Seasonal, spatial, and body size variation in δ13C and δ15N was used to assess isotopic niche overlap and resource and habitat partitioning among the five common offshore Lake Ontario forage fish species (n = 2037; alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), round goby (Neogobius melanostomus), and deepwater (Myoxocephalus thompsonii) and slimy (Cottus cognatus) sculpins). Round goby had the largest isotopic niche (6.1‰2, standard ellipse area), followed by alewife (3.4‰2), while rainbow smelt, slimy sculpin, and deepwater sculpin had the smallest and similar niche size (1.7‰2–1.8‰2), with only the sculpin species showing significant isotopic niche overlap (>63%). Stable isotopes in alewife, round goby, and rainbow smelt varied with location, season, and size, but did not vary in the sculpin species. Lake Ontario forage fish species have partitioned food and habitat resources, and non-native alewife and round goby have the largest isotopic niche, suggestive of a boarder ecological niche, and may contribute to their current high abundance.
The role of paraoxonase 1 in regulating high-density lipoprotein functionality during aging
Authors: Khalil Abdelouahed , Kamtchueng Simo Olivier , Ikhlef Souade , Berrougui Hicham
Published: July 2017

Pharmacological interventions to increase the concentration of high-density lipoprotein (HDL) have led to disappointing results and have contributed to the emergence of the concept of HDL functionality. The anti-atherogenic activity of HDLs can be explained by their functionality or quality. The capacity of HDLs to maintain cellular cholesterol homeostasis and to transport cholesterol from peripheral cells to the liver for elimination is one of their principal anti-atherogenic activities. However, HDLs possess several other attributes that contribute to their protective effect against cardiovascular diseases. HDL functionality is regulated by various proteins and lipids making up HDL particles. However, several studies investigated the role of paraoxonase 1 (PON1) and suggest a significant role of this protein in the regulation of the functionality of HDLs. Moreover, research on PON1 attracted much interest following several studies indicating that it is involved in cardiovascular protection. However, the mechanisms by which PON1 exerts these effects remain to be elucidated.
Spatially and spectrally resolved ultra-narrowband TE-polarization absorber based on the guide-mode resonance
Authors: Liao Yan-Lin , Zhao Yan , Zhang Xingfang , Zhang Wen , Wang Zhongzhu
Published: July 2017

A spatially and spectrally resolved ultra-narrowband absorber with a dielectric grating and metal substrate has been reported. The absorber shows that the absorption rate is more than 0.99 with the absorption bandwidth less than 1.5 nm at normal incidence for TE polarization (electric field is parallel to grating grooves). The angular width of the absorption is about 0.27[Formula: see text]. The wavelength-angle sensitivity and absorption-angle sensitivity are 13.4 nm per degree and 296.3% per degree, respectively. The simulation results also show the spatially and spectrally resolved ultra-narrowband absorption is originated from the guide-mode resonance. In addition, the wavelength-angle sensitivity can be improved by enlarging the grating period according to the guide-mode resonance mechanism. The proposed absorber has potential applications in optical filters, angle measurement and thermal emitters.
Spherical Simplex Unscented Kalman Filter-Based Jumping and Static Interacting Multiple Model
Authors: Pan Yi , Ye Hui , He Keke
Published: July 2017

A modified interacting multiple model (IMM) method called spherical simplex unscented Kalman filter-based jumping and static IMM (SSUKF-JSIMM) is proposed to solve the problem of nonlinear filtering with unknown continuous system parameter. SSUKF-JSIMM regards the continuous system parameter space as a union of disjoint regions, and each region is assigned to a model. For each model, under the assumption that the parameter belongs to the corresponding region, one sub-filter is used to estimate the parameter and the state when the parameter is presumed to be jumping, and another sub-filter is used to estimate the parameter and the state when the parameter is presumed to be static. Considering that spherical simplex unscented Kalman filter (SSUKF) is more suitable for a real-time system than the unscented Kalman filter (UKF), SSUKFs are adopted as the sub-filters of SSUKF-JSIMM. Results of the two SSUKFs are fused as the estimation output of the model. Experimental results show that SSUKF-JSIMM achieves higher performance than IMM, SIR, and UKF in bearings-only tracking problem.
Characterizing classes of regular languages using prefix codes of bounded synchronization delay
Authors: Diekert Volker , Walter Tobias
Published: July 2017

This paper is motivated by the work of Schützenberger on codes with bounded synchronization delay. He was interested in characterizing those regular languages where groups in the syntactic monoid belong to a variety [Formula: see text]. On the language side he allowed the operations union, intersection, concatenation and modified Kleene-star involving a mapping of a prefix code of bounded synchronization delay to a group [Formula: see text], but no complementation. In our notation, this leads to the language classes [Formula: see text]. Our main result shows that [Formula: see text] coincides with the class of languages having syntactic monoids where all subgroups are in [Formula: see text]. We show that this statement holds for all varieties [Formula: see text] of finite groups, whereas Schützenberger proved this result for varieties [Formula: see text] containing Abelian groups, only. Our method shows the result for all [Formula: see text] simultaneously on finite and infinite words. Furthermore, we introduce the notion of local Rees extension which refers to a restricted type of the classical Rees extension. We give a decomposition of a monoid in terms of its groups and local Rees extensions. This gives a somewhat similar, but simpler decomposition than in the synthesis theorem of Rhodes and Allen. Moreover, we need a singly exponential number of operations, only. Finally, our decomposition yields an answer to a question in a recent paper of Almeida and Klíma about varieties that are closed under Rees extensions.
CHARACTERIZATION OF BRUCITE/TiO2 COMPOSITE PARTICLE MATERIAL PREPARED BY MECHANO-CHEMICAL METHOD
Authors: LIANG YU , DING HAO , XUE QIANG
Published: July 2017

Brucite/TiO2 composite particle was prepared with Titanium dioxide (TiO2), coating on brucite particles’ surfaces by mechano-chemical method. X-ray diffraction (XRD), scanning electron microscope (SEM) and infrared spectra were used to investigate the microstructures, morphologies of the composite and the reaction mechanism. The results show that the ground extent of brucite as well as the mixed particles of brucite and TiO2 should keep at a suitable state. The hiding power and whiteness of the composite particles are 17.24[Formula: see text]g/m2 and 96.88%, respectively, presenting its similarity to TiO2 in pigment properties. TiO2 coats evenly on the surfaces of brucite through surface dehydroxylation reaction during mechano-chemical method.
FRACTURE AND WRINKLE PATTERNS IN METAL FILMS DEPOSITED ON LIQUID MENISCUSES
Authors: ZHANG YONG-JU , YU SEN-JIANG , ZHOU HONG , CAI PING-GEN
Published: July 2017

Liquid meniscuses were prepared by spraying silicone oil drops with different sizes onto clean glass slides. Metal (iron) films with varied thicknesses were then deposited on the liquid meniscuses by direct current magnetron sputtering. The fracture and wrinkle behaviors of the films resulting from residual stresses are investigated in detail. It is found that cracks nucleate and propagate in the film during deposition owing to the thermal expansion of the liquid substrate. Subsequent cooling of the system creates a high compressive stress, resulting in the formation of various wrinkles in the film. The initiation and shape of the cracks are closely related to the film thickness and oil drop size. The wrinkle morphologies are dependent on the stress anisotropy induced by the liquid meniscus and crack edge.
FRACTAL FEATURES OF THE QUANTIZED SCANNING TUNNELING CURRENT AND THE LOCAL DENSITY OF STATES FOR A QUANTUM CORRAL
Authors: TATSUMI YOHHEI , MITSUOKA SHIGENORI , TAMURA AKIRA
Published: July 2017

We found that quantization of the scanning tunneling microscope (STM) current becomes apparent as the size of a quantum corral (QC) decreases and the corral thickness increases. It is shown that STM current images provide the position dependence of the conduction channels and local density of states (LDOS) images provide the spatial distribution of differential conductance channels. We clarified for the first time that there exist fractal structures in the QC size dependence of the [Formula: see text]–[Formula: see text] characteristic and in that of the LDOS. LDOS images also exhibit a fractal structure as a function of bias voltage. These results demonstrate fractal structures in energy space and real space. For an extremely large QC, we found that the [Formula: see text]–[Formula: see text] curve becomes Ohmic and the LDOS converges to a constant corresponding to the bulk two-dimensional density of states.
The Influence of the Substitution of Transition Metals on Pristine C20: A DFT Study
Authors: Paul Debolina , Deb Jyotirmoy , Bhattacharya Barnali , Sarkar Utpal
Published: July 2017

The stabilities and reactivities of two transition metal ([Formula: see text], Zn)-doped structures of C[Formula: see text] fullerene have been investigated by density functional theory approach. We have observed a noticeable structural change in pristine C[Formula: see text] due to the substitution of one of its carbon atom by Cu or Zn atom. From our findings, it is found that the energy gap of C[Formula: see text]Cu and C[Formula: see text]Zn increases with respect to pristine C[Formula: see text], thus making the two doped fullerenes more stable than their pristine counterpart. The reactivity parameters such as chemical hardness, chemical potential and electrophilicity index for these structures are also studied. Interestingly, our calculations reveal that both the doped fullerenes obey the maximum hardness principle and minimum electrophilicity principle. Also, from the electronic absorption spectra analysis, it can be inferred that the maximum absorption peak of the two heteroatom-substituted fullerenes C[Formula: see text]Cu and C[Formula: see text]Zn are shifted towards the longer wavelength region as compared to the pure C[Formula: see text] fullerene, which clearly indicates that a red shift is introduced on account of doping.
Opto-Electronic Properties of Green Synthesized ZnS Nanostructures
Authors: Deb Sujata , Kalita P. K. , Datta P.
Published: July 2017

ZnS nanostructures are synthesized by a wet chemical route using starch as green capping agent under nitrogen environment. The as-prepared nanostructures are characterized structurally, optically and electrically. X-ray diffraction (XRD) spectra confirm that the zinc sulfide (ZnS) nanoparticles have cubic phase (zinc blende). UV–Vis spectrum of the sample clearly shows that the absorption peak exhibits blue shift compared to their bulk counterpart, which confirms the quantum confinement effect of the nanostructures. Its photoluminescence (PL) spectrum shows near band gap emission at 392[Formula: see text]nm and extrinsic emission at 467[Formula: see text]nm. The particle sizes calculated from XRD and UV studies are in fair agreement with high resolution transmission electron microscopy (HRTEM) results. Starch is found to be a noble capping agent in bringing quantum confinement. The synthesis under nitrogen environment has been observed to produce quality products by reducing the oxide traces. Moreover, the I–V characteristics under dark and illumination show that ZnS can be more suitable as photodetector.
ZnTPPS demetalation: Role of polyelectrolytes on aggregation after protonation in acid
Authors: Gaeta Massimiliano , Randazzo Rosalba , Cristaldi Domenico Andrea , D’Urso Alessandro , Purrello Roberto , Fragalà Maria Elena
Published: July 2017

Acid-base properties of tetra-anionic zinc meso-5,10,15,20-tetrakis-(4-sulfonatophenyl)porphyrin (ZnTPPS) in presence of cationic and anionic polyelectrolytes are studied by UV-visible spectroscopy. In fact, spectral modifications related to the out-of-plane deformation of porphyrins after protonation allow for an easy probing of the protonation event that, in presence of a metal derivative, requires a deprotonation step. Interactions with poly-D-glutamate and poly-L-lysine, modulated by system electrostatics and by the presence of an axially-coordinated central metal ion, trigger both protonation occurrences as well as porphyrin self-aggregation. The crucial role of electrostatic interactions experienced by the metalated inner core in strong acid solution, probed by UV-visible spectroscopy, are discussed.
Effect of Aging Time on the Characteristics and Photocatalysis of Zn2+-Doped CTAB@BiOCl
Authors: Yu Yichang , Hu Zhangjun , Li Chengjun , Huang Shoushuang , Chen Zhiwen , Gao Hongwen
Published: July 2017

Zn[Formula: see text]-doped CTAB@BiOCl inorganic–organic composites were prepared by a co-precipitation method with different aging periods. The results show that the aging period has great influence on the structure, morphology and surface area of Zn[Formula: see text]-doped CTAB@BiOCl. The as-synthesized samples tend to form lamellar stacking structure with the increase of the aging time. In addition, the surface area and pore size distribution of samples decrease with the aging period from 0[Formula: see text]h to 48[Formula: see text]h and then increase from 48[Formula: see text]h to 96[Formula: see text]h. Besides, the content of CTAB in these composites increases along with the aging period from 0[Formula: see text]h to 3[Formula: see text]h and then decreases from 3[Formula: see text]h to 96[Formula: see text]h. Their photocatalytic performances were evaluated by the degradation of Reactive Red 3 (X3B) under UV light irradiation. It is found that the photocatalytic performance of composites increases with the prolonging of the aging time, and 100[Formula: see text]mg/L of X3B solution can be almost completely degraded within 16[Formula: see text]min by S[Formula: see text]. Moreover, the possible formation mechanism has been proposed and discussed in detail. The work can provide a new sight for broadening the application of co-precipitation in the preparation of nanomaterials and for in-situ one-step synthesis of inorganic–organic composites.
An algorithm for pairwise comparison of alternatives in multi-criteria problems
Authors: Smerchinskaya Svetlana O. , Yashina Nina P.
Published: July 2017

Difficult decisions and problems arise in almost all areas of human activities. In most tasks, the choice of the best alternatives is produced on the basis of task of numeral estimations of alternatives on the criteria of quality. The article considers the problem of multi-criteria choice with nonuniform scales of criteria. Algorithm for pairwise comparison of alternatives, based on the construction of the criteria preference matrices, containing information on the degree of superiority of one alternative over another, is offered. Transitivity of aggregated relation, built for two criteria, is proved. The results, obtained using the method of additive convolution and the proposed algorithm, are compared.
The upper Permian Cadeby Formation in the Boston Spa area, West Yorkshire, UK
Authors: Tymon Alison M. , Malcolm Barnes J. , Freeman Jeremy W. , Gaussen Terence H. , Holliday Douglas W. , Rayner Alan M. , Tymon Barry G.
Published: July 2017

Undescribed carbonate exposures in the Boston Spa area have been studied in detail in order to give a comprehensive account of the stratigraphy and facies there of the upper Permian (Lopingian Series) Cadeby Formation of the Zechstein Group. The Cadeby Formation was deposited close to the western margin of the Zechstein Basin, in the Yorkshire sub-basin. All the strata in the study area are of shallow water origin, and are thought to have close analogues with modern carbonate sediments in the Arabian/Persian Gulf. The Cadeby Formation comprises the Wetherby Member overlain by the Sprotbrough Member. The contact between the members is here placed at the Hampole Discontinuity, which marks a subaerial erosion surface. The Wetherby Member includes bryozoan patch reefs and was deposited on a marginal carbonate shelf of the Zechstein Basin. The Hampole Beds, which are here placed at the base of the Sprotbrough Member, were deposited during a period of relatively low basin-wide sea-level. They include features that suggest deposition in intertidal and supratidal environments. Influxes of fine clays gave rise to thin mudstones within the Hampole Beds. Particularly around Wetherby, there are also several impersistent mudstones in the strata above the Hampole Beds. These are considered to have been deposited during regression; the associated dolomites have features typical of supratidal conditions, such as fenestrae and microbial laminae, indicative of local temporary emergence. Shallow subtidal dolomites of the Sprotbrough Member above the Hampole Beds include cross-stratification that indicates sandwaves. A lens of clastic material near the top of the formation at Wetherby is interpreted as a flash flood deposit, probably sourced from emergent areas to the west. The upper beds of the Sprotbrough Member show dedolomitization, brecciation and karstic weathering, precursors to the deposition of the terrestrial red clays of the overlying Edlington Formation. Minor post-Permian barite mineralization is found and its distribution is related to underlying structural features.
Sedimentary context and palaeoecology of
Gigantoproductus
shell beds in the Mississippian Eyam Limestone Formation, Derbyshire carbonate platform, central England
Authors: Nolan L. S. P. , Angiolini L. , Jadoul F. , Della Porta G. , Davies S. J. , Banks V. J. , Stephenson M. H. , Leng M. J.
Published: July 2017

A sedimentological study was conducted at two localities exposing the Mississippian Eyam Limestone Formation of the Derbyshire carbonate platform, UK. Ricklow Quarry comprises seven facies with diverse skeletal assemblages, representing deposition on the inner to middle ramp within open marine waters. Once-a-Week Quarry comprises four facies, dominated by crinoidal debris representing deposition on the inner ramp. Both localities expose
Gigantoproductus
shell beds. Palaeoecological analysis of a single shell bed from each locality enabled investigation of the rapid colonization and success of this taxon on the platform. At Ricklow Quarry, on the eastern side of a localized mud mound, both life (>72% of thin and thick-shelled brachiopods in life position) and neighbourhood assemblages are present. A low-moderate diversity community (<1.37 and <0.8 Shannon diversity index) rapidly established over relict Brigantian mud mounds. Shell beds are preluded by intervals of decreased energy that allowed larvae to settle. Once established, the dominance of thick-shelled individuals enabled baffling, potentially providing localized shelter for larvae and nearby individuals. At Once-a-Week Quarry, where no mud mound is present, only thick-shelled
Gigantoproductus
species and a low diversity community (<1.07 Shannon diversity index) exclusively comprising neighbourhood assemblages (37% in life position) is present. The presence of inactive mud mounds at Ricklow Quarry appears to have been the key to the success of
Gigantoproductus
species enabling the onset of stable communities in the shelter provided by the relict mound. Once the first palaeocommunities were established, larvae dispersed and colonized higher energy settings, such as at Once-a-Week Quarry.
Two-Scale Topology Optimization with Microstructures
Authors: Zhu Bo , Skouras Mélina , Chen Desai , Matusik Wojciech
Published: July 2017

In this article, we present a novel two-scale framework to optimize the structure and the material distribution of an object given its functional specifications. Our approach utilizes multi-material microstructures as low-level building blocks of the object. We start by precomputing the material property gamut—the set of bulk material properties that can be achieved with all material microstructures of a given size. We represent the boundary of this material property gamut using a level set field. Next, we propose an efficient and general topology optimization algorithm that simultaneously computes an optimal object topology and spatially varying material properties constrained by the precomputed gamut. Finally, we map the optimal spatially varying material properties onto the microstructures with the corresponding properties to generate a high-resolution printable structure. We demonstrate the efficacy of our framework by designing, optimizing, and fabricating objects in different material property spaces on the level of a trillion voxels, that is, several orders of magnitude higher than what can be achieved with current systems.
How to Characterize Habitable Worlds and Signs of Life
Authors: Kaltenegger Lisa
Published: July 2017

The detection of exoplanets orbiting other stars has revolutionized our view of the cosmos. First results suggest that it is teeming with a fascinating diversity of rocky planets, including those in the habitable zone. Even our closest star, Proxima Centauri, harbors a small planet in its habitable zone, Proxima b. With the next generation of telescopes, we will be able to peer into the atmospheres of rocky planets and get a glimpse into other worlds. Using our own planet and its wide range of biota as a Rosetta stone, we explore how we could detect habitability and signs of life on exoplanets over interstellar distances. Current telescopes are not yet powerful enough to characterize habitable exoplanets, but the next generation of telescopes that is already being built will have the capabilities to characterize close-by habitable worlds. The discussion on what makes a planet a habitat and how to detect signs of life is lively. This review will show the latest results, the challenges of how to identify and characterize such habitable worlds, and how near-future telescopes will revolutionize the field. For the first time in human history, we have developed the technology to detect potential habitable worlds. Finding thousands of exoplanets has taken the field of comparative planetology beyond the Solar System.
Probabilistic Computations for Attention, Eye Movements, and Search
Authors: Eckstein Miguel P.
Published: July 2017

The term visual attention immediately evokes the idea of limited resources, serial processing, or a zoom metaphor. But evidence has slowly accumulated that computations that take into account probabilistic relationships among visual forms and the target contribute to optimizing decisions in biological and artificial organisms, even without considering these limited-capacity processes in covert attention or even foveation. The benefits from such computations can be formalized within the framework of an ideal Bayesian observer and can be related to the classic theory of sensory cue combination in vision science and context-driven approaches to object detection in computer vision. The framework can account for a large range of behavioral findings across distinct experimental paradigms, including visual search, cueing, and scene context. I argue that these forms of probabilistic computations might be fundamental to optimizing decisions in many species and review human experiments trying to identify scene properties that serve as cues to guide eye movements and facilitate search. I conclude by discussing contributions of attention beyond probabilistic computations but argue that the framework's merit is to unify many basic paradigms to study attention under a single theory.
Binocular Mechanisms of 3D Motion Processing
Authors: Cormack Lawrence K. , Czuba Thaddeus B. , Knöll Jonas , Huk Alexander C.
Published: July 2017

The visual system must recover important properties of the external environment if its host is to survive. Because the retinae are effectively two-dimensional but the world is three-dimensional (3D), the patterns of stimulation both within and across the eyes must be used to infer the distal stimulus—the environment—in all three dimensions. Moreover, animals and elements in the environment move, which means the input contains rich temporal information. Here, in addition to reviewing the literature, we discuss how and why prior work has focused on purported isolated systems (e.g., stereopsis) or cues (e.g., horizontal disparity) that do not necessarily map elegantly on to the computations and complex patterns of stimulation that arise when visual systems operate within the real world. We thus also introduce the binoptic flow field (BFF) as a description of the 3D motion information available in realistic environments, which can foster the use of ecologically valid yet well-controlled stimuli. Further, it can help clarify how future studies can more directly focus on the computations and stimulus properties the visual system might use to support perception and behavior in a dynamic 3D world.
Explorations in statistics: the assumption of normality
Authors: Curran-Everett Douglas
Published: July 2017

Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This twelfth installment of Explorations in Statistics explores the assumption of normality, an assumption essential to the meaningful interpretation of a t test. Although the data themselves can be consistent with a normal distribution, they need not be. Instead, it is the theoretical distribution of the sample mean or the theoretical distribution of the difference between sample means that must be roughly normal. The most versatile approach to assess normality is to bootstrap the sample mean, the difference between sample means, or t itself. We can then assess whether the distributions of these bootstrap statistics are consistent with a normal distribution by studying their normal quantile plots. If we suspect that an inference we make from a t test may not be justified—if we suspect that the theoretical distribution of the sample mean or the theoretical distribution of the difference between sample means is not normal—then we can use a permutation method to analyze our data.
Respiratory muscle endurance training reduces the O2 cost of cycling and perceived exertion in obese adolescents
Authors: Salvadego Desy , Sartorio Alessandro , Agosti Fiorenza , Tringali Gabriella , Patrizi Alessandra , Isola Miriam , LoMauro Antonella , Aliverti Andrea , Grassi Bruno
Published: July 2017

In obesity, the increased O2 cost of breathing negatively affects the O2 cost of exercise and exercise tolerance. The purpose of the study was to determine whether, in obese adolescents, the addition of respiratory muscle endurance training (RMET) (isocapnic hyperpnea) to a standard body mass reduction program decreases the O2 cost of exercise and perceived exertion. Nine male obese adolescents [16.0 ± 1.4 yr ( x ± SD), body mass 114.4 ± 22.3 kg] underwent 3 wk of RMET (5 days/week) in addition to a standard body mass reduction program. Eight age- and sex-matched obese adolescents underwent only the standard program (CTRL). Before and after interventions, patients performed on a cycle ergometer: incremental exercise; 12-min exercises at a constant work rate (CWR) of 65% and 120% at the gas exchange threshold (GET) determined before the intervention. Breath-by-breath pulmonary ventilation (V̇e) and O2 uptake (V̇o2), heart rate (HR), and ratings of perceived exertion for dyspnea/respiratory discomfort (RPER) and leg effort (RPEL) were determined. Body mass decreased (by ~3.0 kg) after both RMET ( P = 0.003) and CTRL ( P = 0.002). Peak V̇o2 was not affected by both interventions. Peak work rate was slightly, but significantly ( P = 0.04), greater after RMET but not after CTRL. During CWR < GET, no changes were observed after both interventions. During CWR > GET, the O2 cost of cycling at the end of exercise ( P = 0.02), the slope of V̇o2 vs. time (3–12 min) ( P = 0.01), RPER ( P = 0.01), and RPEL ( P = 0.01) decreased following RMET, but not following CTRL. HR decreased after both RMET ( P = 0.02) and CTRL ( P = 0.03), whereas V̇e did not change. In obese adolescents RMET, superimposed on a standard body mass reduction program, lowered the O2 cost of cycling and perceived exertion during constant heavy-intensity exercise.
Spot urine protein measurements in normotensive pregnancies, pregnancies with isolated proteinuria and preeclampsia
Authors: Kattah Andrea , Milic Natasa , White Wendy , Garovic Vesna
Published: July 2017

We performed a prospective, longitudinal study of pregnant women presenting to their first obstetrics visits to characterize the changes in spot urine protein-to-creatinine (UPCR) and albumin-to-creatinine ratios (UACR) in normotensive pregnancies, as well as identify clinical characteristics associated with isolated proteinuria and preeclampsia. We measured spot urinary albumin, protein, and creatinine at the first prenatal visit, end of the second trimester, and at delivery. In the normotensive pregnancies ( n = 142), we found that from the beginning of pregnancy to delivery, UACR increased by a median [interquartile range (IQR)] of 14.7 mg/g Cr (3.74–51.8) and UPCR by 60 mg/g Cr (30–130) ( P < 0.001 for both changes). Isolated proteinuria (defined as UPCR > 300 mg/g Cr in the absence of hypertension) was identified in 19/142 (13.4%) normotensive pregnancies. Increases in systolic and diastolic blood pressure from early pregnancy to delivery and increases in UACR from early to midpregnancy were associated with isolated proteinuria at delivery. Twelve women developed preeclampsia. Nulliparity, early, and midpregnancy diastolic blood pressures were strongly associated with the development of preeclampsia, but early changes in UACR were not. In conclusion, women who develop isolated proteinuria at delivery have a larger increase in blood pressure than women without proteinuria and have a “microalbuminuric” phase earlier in gestation, unlike women who develop preeclampsia. These findings suggest a different mechanism of urine protein excretion in women with isolated proteinuria as compared with women with preeclampsia, where proteinuria has a more abrupt onset.