Do logarithmic proximity measures outperform plain ones in graph clustering?

We consider a number of graph kernels and proximity measures including commute time kernel, regularized Laplacian kernel, heat kernel, exponential diffusion kernel (also called "communicability"), etc., and the corresponding distances as applied to clustering nodes in random graphs and several well-known datasets. The model of generating random graphs involves edge probabilities for the pairs of nodes that belong to the same class or different predefined classes of nodes. It turns out that in most cases, logarithmic measures (i.e., measures resulting after taking logarithm of the proximities) perform better while distinguishing underlying classes than the "plain" measures. A comparison in terms of reject curves of inter-class and intra-class distances confirms this conclusion. A similar conclusion can be made for several well-known datasets. A possible origin of this effect is that most kernels have a multiplicative nature, while the nature of distances used in cluster algorithms is an additive one (cf. the triangle inequality). The logarithmic transformation is a tool to transform the first nature to the second one. Moreover, some distances corresponding to the logarithmic measures possess a meaningful cutpoint additivity property. In our experiments, the leader is usually the logarithmic Communicability measure. However, we indicate some more complicated cases in which other measures, typically, Communicability and plain Walk, can be the winners.Comment: 11 pages, 5 tables, 9 figures. Accepted for publication in the Proceedings of 6th International Conference on Network Analysis, May 26-28, 2016, Nizhny Novgorod, Russi

The relationship between the antibiotic consumption in hospitals and the community and the selection of methicillin-resistant Staphylococcus aureus

International audienc

HYDROBIA ULVAE: A DEPOSIT-FEEDER FOR CLEANING LIVING HARD-SHELLED FORAMINIFERA

International audienceThis study proposes a new method for fast and inexpensive extraction of a large number of living foraminifera for laboratory cultures. The method is a significant improvement over current extraction methods, which are highly time-consuming. Several treatments were designed to test the method. Sediment bearing foraminifera from Brouage Mudflat (Atlantic coast of France) was washed through a 50-µm sieve and distributed in glass Petri dishes with 20, 40 and 80 specimens of Hydrobia ulvae, a common gastropod from European intertidal mudflats. As a control experiment, one dish was treated similarly but maintained without Hydrobia. After two days, most of the sediment in the Hydrobia treatments was compacted into small cylindrical gastropod feces and the tests of living benthic foraminifera (Ammonia tepida and Haynesina germanica) were clean and easily visible. Additional experiments showed that the foraminifera were not ingested by Hydrobia ulvae, and could be picked quickly and easily

Capillary origami: spontaneous wrapping of a droplet with an elastic sheet

The interaction between elasticity and capillarity is used to produce three dimensional structures, through the wrapping of a liquid droplet by a planar sheet. The final encapsulated 3D shape is controlled by tayloring the initial geometry of the flat membrane. A 2D model shows the evolution of open sheets to closed structures and predicts a critical length scale below which encapsulation cannot occur, which is verified experimentally. This {\it elastocapillary length} is found to depend on the thickness as $h^{3/2}$, a scaling favorable to miniaturization which suggests a new way of mass production of 3D micro- or nano-scale objects.Comment: 5 pages, 5 figure

Effect of plant traits and substrate moisture on the thermal performance of different plant species in vertical greenery systems

This study evaluated the effects of plant traits and substrate moisture on the thermal performance of four herbs and four shrubs, which are the most commonly used species in vertical greenery systems (VGSs), in humid subtropical Hong Kong over a one-year period. The canopy temperature reduction on sunny days was significantly correlated with canopy coverage and leaf area index (LAI), but not with daily evapotranspiration (ET). This indicated that the shading effect of VGSs, which is related to canopy coverage and LAI, was more prominent than ET cooling. The lack of significant correlation between substrate moisture, ET and canopy temperature indicated that substrate moisture and ET did not significantly enhance the canopy cooling of VGSs. Substrate moisture notably cooled the substrate on sunny days, and warmed the substrate on rainy days, which significantly affected substrate thermal behavior, but had less effect on canopy air temperature. The use of VGSs with eight common plant species on building envelopes reduced steady-state heat conduction by 18.7–39.8%, with Ficus elastica (rubber fig) causing the greatest canopy cooling

The role of extracellular matrix elasticity and composition in regulating the nucleus pulposus cell phenotype in the intervertebral disc: a narrative review.

Intervertebral disc (IVD) disorders are a major contributor to disability and societal health care costs. Nucleus pulposus (NP) cells of the IVD exhibit changes in both phenotype and morphology with aging-related IVD degeneration that may impact the onset and progression of IVD pathology. Studies have demonstrated that immature NP cell interactions with their extracellular matrix (ECM) may be key regulators of cellular phenotype, metabolism and morphology. The objective of this article is to review our recent experience with studies of NP cell-ECM interactions that reveal how ECM cues can be manipulated to promote an immature NP cell phenotype and morphology. Findings demonstrate the importance of a soft (<700 Pa), laminin-containing ECM in regulating healthy, immature NP cells. Knowledge of NP cell-ECM interactions can be used for development of tissue engineering or cell delivery strategies to treat IVD-related disorders

Evaluation of the first automated thyroglobulin assay

The aim of this study was to investigate technical and analytical performance of the first automated thyroglobulin (Tg) assay (DPC-Immulite(R); Diagnostic Products Corporation, Los Angeles, USA). In imprecision studies using several human serum pools ranging from 21 to 58 replicates, a coefficient of variation of 9.0 % was obtained at a mean Tg concentration of 0.84 ng/ml and of 6.1 % at a Tg concentration of 62.1 ng/ml. In a method comparison with a non-automated assay (BRAHMS LUMItest Tg(R), BRAHMS, Berlin, Germany) using 383 sera of 303 patients with thyroid carcinoma, regression analysis according to Passing and Bablock yielded in the following equation: Immulite Tg=1.6 x BRAHMS Tg - 0.1 ng/ml (Pearson's r=0.979). Sera obtained from 59 patients with thyroid carcinoma enabled comparative follow-up studies; in all cases qualitative agreement was found with regard to increase or decrease of serum Tg; in eight cases, however, Tg was detected with the Immulite assay but not with the BRAHMS assay. Further follow-up proved the presence of thyroid tissue in these patients. From these and further methodological data (dilution linearity, interference studies, carry-over study, high-dose hook properties, and short report time) it is concluded that the DPC-Immulite Tg assay meets the requirements of routine diagnostic use

Photocrosslinkable laminin-functionalized polyethylene glycol hydrogel for intervertebral disc regeneration

Intervertebral disc (IVD) disorders and age-related degeneration are believed to contribute to lower back pain. There is significant interest in cell-based strategies for regenerating the nucleus pulposus (NP) region of the disc; however, few scaffolds have been evaluated for their ability to promote or maintain an immature NP cell phenotype. Previous studies have shown that NP cell-laminin interactions promote cell adhesion and biosynthesis, which suggests a laminin-functionalized biomaterial may be useful for promoting or maintaining the NP cell phenotype. Here, a photocrosslinkable poly(ethylene glycol)-laminin 111 (PEG-LM111) hydrogel was developed. The mechanical properties of PEG-LM111 hydrogel could be tuned within the range of dynamic shear moduli values previously reported for human NP. When primary immature porcine NP cells were seeded onto PEG-LM111 hydrogels of varying stiffnesses, LM111-presenting hydrogels were found to promote cell clustering and increased levels of sGAG production as compared to stiffer LM111-presenting and PEG-only gels. When cells were encapsulated in 3-D gels, hydrogel formulation was found to influence NP cell metabolism and expression of proposed NP phenotypic markers, with higher expression of N-cadherin and cytokeratin 8 observed for cells cultured in softer (<1 kPa) PEG-LM111 hydrogels. Overall, these findings suggest that soft, LM111-functionalized hydrogels may promote or maintain the expression of specific markers characteristic of an immature NP cell phenotype. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Wideband feeding method for full-wave dipole

© 2017 IEEE. This paper introduces a wide-band feeding method for full-wave dipole antennas. A full-wave dipole is designed to cover the band from 698 MHz to 960 MHz for cellular base station applications. Its matching circuit consists of a laddertype filter design and a quasi-quarter-wavelength resistance transformer. The proposed matching circuit can provide balanced feeding as a balun and has a compact size. The matching circuit is designed and optimized using a circuit theory model and then physically realized using microstrip lines based on full-wave simulation. The simulated reflection coefficient |S11| is < -15 dB across the entire target band, exhibiting a bandwidth of 32%

Environmental factors and mortality risks associated influenza

BACKGROUND AND AIMS: The subtropical and tropical regions exhibit a distinct seasonality of influenza incidence from the temperate regions, and the mechanism behind it remains unclear. Environmental factors have been related to the transmission and survival of influenza viruses but no studies have ever explored the role of environmental factors on regulating severity of influenza infection. METHODS: We applied a Poisson regression model to the mortality data of two Asian metropolitan cities located at the subtropical zone, Guangzhou and Hong Kong. Interaction between …postprin