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21.
A review of Garfield??s journal impact factor and its specific implementation as the Thomson Reuters impact factor reveals several weaknesses in this commonly-used indicator of journal standing. Key limitations include the mismatch between citing and cited documents, the deceptive display of three decimals that belies the real precision, and the absence of confidence intervals. These are minor issues that are easily amended and should be corrected, but more substantive improvements are needed. There are indications that the scientific community seeks and needs better certification of journal procedures to improve the quality of published science. Comprehensive certification of editorial and review procedures could help ensure adequate procedures to detect duplicate and fraudulent submissions.  相似文献   
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In this paper, we propose a novel formulation extending convolutional neural networks (CNN) to arbitrary two-dimensional manifolds using orthogonal basis functions called Zernike polynomials. In many areas, geometric features play a key role in understanding scientific trends and phenomena, where accurate numerical quantification of geometric features is critical. Recently, CNNs have demonstrated a substantial improvement in extracting and codifying geometric features. However, the progress is mostly centred around computer vision and its applications where an inherent grid-like data representation is naturally present. In contrast, many geometry processing problems deal with curved surfaces and the application of CNNs is not trivial due to the lack of canonical grid-like representation, the absence of globally consistent orientation and the incompatible local discretizations. In this paper, we show that the Zernike polynomials allow rigourous yet practical mathematical generalization of CNNs to arbitrary surfaces. We prove that the convolution of two functions can be represented as a simple dot product between Zernike coefficients and the rotation of a convolution kernel is essentially a set of 2 × 2 rotation matrices applied to the coefficients. The key contribution of this work is in such a computationally efficient but rigorous generalization of the major CNN building blocks.  相似文献   
24.
Under the National Ambient Air Quality Standard (NAAQS) for airborne lead, measurements are conducted by means of a high-volume total suspended particulate matter (Hi-Vol TSP) sampler. In the decade between 1973 and 1983, there were 12 publications that explored the sampling characteristics and effectiveness of the Hi-Vol TSP, yet there persists uncertainty regarding its performance. This article presents an overview of the existing literature on the performance of the Hi-Vol TSP, and identifies the reported sampler effectiveness with respect to four factors: particle size (reported effectiveness of 7%–100%), wind speed (?36% to 100%), sampler orientation (7%–100%), and operational state (107%–140%). Effectiveness of the Hi-Vol TSP was evaluated with a solid, polydisperse aerosol in a controlled wind tunnel setting. Isokinetic samplers were deployed alongside the Hi-Vol TSP to investigate three wind speeds (2, 8, and 24 km h?1), three sampler orientations (0°, 45°, 90°), and two operational states (on, off) for aerosols with aerodynamic diameters from 5 to 35 µm. Results indicate that particle diameter was the largest determining factor of effectiveness followed by wind speed. Orientation of the sampler did not have a significant effect at 2 and 8 km h?1 but did at 24 km h?1. In a passive state, the Hi-Vol TSP was collected between 1% and 7% of available aerosol depending on particle size and wind speed. Results of this research do not invalidate results of previous studies but rather contribute to our overall understanding of the Hi-Vol TSP's size-selective performance. While results generally agreed with previous studies, the Hi-Vol TSP was found to exhibit less dependence on these four factors than previously reported.

© 2017 American Association for Aerosol Research  相似文献   
25.
The Food System     
Shelley Jordon describes her artwork as celebrating “the power and the beauty of domestic spaces and objects…culled from daily life.” Food is among the most basic of daily human needs, yet what is most basic often gets overlooked. Alpenrose, her image of a breakfast table, brings this human need to the fore, as authors Ka-meshwari Pothukucki and Jerome L. Kaufman argue that food systems need a place among the concerns of planners.

The artist, who is an associate professor of art at Oregon State University, resides in Portland, Oregon. Her works can be found in galleries and private collections throughout the West Coast.

Planning lays claim to being comprehensive, future-oriented, and public-interest driven, and of wanting to enhance the livability of communities. It is concerned with community systems—such as land use, housing, transportation, the environment, and the econ-omy—and their interconnections. The food system, however, is notable by its absence from most planning practice, research, and education. We present evidence for the limited presence of the food system in planning's list of concerns by scanning leading journals, texts, and classic writings, and by reporting on a survey of 22 U.S. city planning agencies. We analyze this low level of attention and discuss reasons and ideas for planning involvement to strengthen community food systems.1  相似文献   
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Uropathogenic E. coli (UPEC) employ the mannose‐binding adhesin FimH to colonize the bladder epithelium during urinary tract infection (UTI). Previously reported FimH antagonists exhibit good potency and efficacy, but low bioavailability and a short half‐life in vivo. In a rational design strategy, we obtained an X‐ray structure of lead mannosides and then designed mannosides with improved drug‐like properties. We show that cyclizing the carboxamide onto the biphenyl B‐ring aglycone of biphenyl mannosides into a fused heterocyclic ring, generates new biaryl mannosides such as isoquinolone 22 (2‐methyl‐4‐(1‐oxo‐1,2‐dihydroisoquinolin‐7‐yl)phenyl α‐d ‐mannopyranoside) with enhanced potency and in vivo efficacy resulting from increased oral bioavailability. N‐Substitution of the isoquinolone aglycone with various functionalities produced a new potent subseries of FimH antagonists. All analogues of the subseries have higher FimH binding affinity than unsubstituted lead 22 , as determined by thermal shift differential scanning fluorimetry assay. Mannosides with pyridyl substitution on the isoquinolone group inhibit bacteria‐mediated hemagglutination and prevent biofilm formation by UPEC with single‐digit nanomolar potency, which is unprecedented for any FimH antagonists or any other antivirulence compounds reported to date.  相似文献   
28.
Mitochondrial dysfunctions are implicated in several pathologies, such as metabolic, cardiovascular, respiratory, and neurological diseases, as well as in cancer and aging. These metabolic alterations are usually assessed in human or murine samples by mitochondrial respiratory chain enzymatic assays, by measuring the oxygen consumption of intact mitochondria isolated from tissues, or from cells obtained after physical or enzymatic disruption of the tissues. However, these methodologies do not maintain tissue multicellular organization and cell-cell interactions, known to influence mitochondrial metabolism. Here, we develop an optimal model to measure mitochondrial oxygen consumption in heart and lung tissue samples using the XF24 Extracellular Flux Analyzer (Seahorse) and discuss the advantages and limitations of this technological approach. Our results demonstrate that tissue organization, as well as mitochondrial ultrastructure and respiratory function, are preserved in heart and lung tissues freshly processed or after overnight conservation at 4 °C. Using this method, we confirmed the repeatedly reported obesity-associated mitochondrial dysfunction in the heart and extended it to the lungs. We set up and validated a new strategy to optimally assess mitochondrial function in murine tissues. As such, this method is of great potential interest for monitoring mitochondrial function in cohort samples.  相似文献   
29.
In many reinforced composite manufacturing processes it is necessary to compact the fiber materials to obtain the desired fiber/resin ratio in the finished part. Detailed knowledge of applied surface force versus material fiber volume is particularly important in processes such as pultrusion, resin transfer molding, and compression molding. The force required to compact a stack of reinforcing material is strongly dependent on the type of fiber used and its material form. Complicated interactions are possible, particularly when mixtures of unidirectional, oriented cloth and random fiber mats are used. This paper will present results of an experimental and analytical investigation of the response of various dry reinforcing materials subjected to compressive forces applied normal to their principle plane. Experiments were conducted by applying up to 8.6 MPa normal force to thick stacks of E-glass, graphite cloth, mat and unidirectional material and combinations of two different fiber orientation. Pressure versus fiber volume data were generated for both individual materials and various combinations. Experimental results were compared to analytical predictions. Data showed that the force versus deformation is very strongly dependent on the details of the fiber form or forms being used. There is structural relaxation during fiber compression. Relaxation is very related to fiber orientation, span length, and fiber breakage during compaction. Relaxation behavior decreases with fiber alignment. Random mats and 0/90 cloth show much more relaxation than unidirectional fibers. Data of relaxation is very well fitted with a Maxwell-Wiechert viscoelastic model.  相似文献   
30.
Direct probing of the conductivity distribution in organic materials is motivated by the need to obtain a deeper understanding of carrier behavior in organic thin-film transistors (OTFT), organic electro-luminescent devices, organic photoconductors, and organic biosensors. Here we used a near-field scanning microwave microscope to visualize conductivity profiles in OTFT channel. Applying this technique to pentacene field-effect transistors has revealed changes of the conductivity distribution in the channel arising from the development and exhaustion of an accumulated charge region. The electric field profiles, the complementary image of conductivity profiles, which are visualized by using an optical second harmonic generation method, support the results. We anticipate that direct observation by this microwave method will find wide application in measurement of carrier conductivity in organic and nonorganic materials.  相似文献   
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