Application of artificial neural networks in the geographical identification of coffee samples

The recognition of the characteristics of coffee associated with a given agricultural system and aimed at adding value and attending the consumers’ demands stimulates the production of types of coffee properly described. The objective of this study was to explore and to explain the physicochemical characteristics and sensory attributes of the coffee grown in Parana State (Southern Brazil) based on an integrated approach of the terrior and the application of artificial neural network. Physicochemical variables of green coffee beans and roasted coffee beans were determined, as well as sensory attributes of the beverage. One hundred and seventy-two coffee samples were analyzed for moisture, proteins, chlorogenic acids, tannins, total acidity, total lipids, caffeine, total and reducing sugars and minerals. These properties were tabulated and presented to artificial neural network multilayer perceptron to be identified as the region and the city of planting. The artificial neural network classified correctly and tested 100% of the samples grown by region. For the database containing information by city, the automatic mode of the software Statistica 9.0 was used. The neural network showed 99% accuracy in training and 100% accuracy in the stage of testing and validation.     

Improved understanding of metal ion reservoirs within barrier-metal systems

Within integrated circuits there are many instances where low current density lines feed directly (without a via) into a single line of much higher current density, for example with clock or power supply distribution. This work demonstrates and discusses increased lifetime with increasing numbers of current feed lines in a barrier metal interconnect system. The low current density feed lines (branches) act as reservoirs or sources of additional Al and Cu ions, which can re-fill portions of voids and/or slow void growth in the high current density line (trunk). It is discussed that any area of metal at a lower current density might be considered a reservoir or source of metal ions for higher current density regions, and can effectively extend the lifetime of the higher current density region. Narrow lines may get more benefit than wide lines. Increasing reservoir size will increase lifetime, within limits.     

Choosing communication portfolios to accomplish tasks: The effects of individual differences

The myriad of information communication technologies (ICTs) available today has changed the way students choose and use them. Specifically, individuals are increasingly relying on a mix of ICTs for communication to accomplish tasks. Yet, past studies on ICT use has largely assumed that people use a single ICT per task. We attempt to address this gap by focusing on the influence of individual differences on the choice of communication portfolio (a mix of ICTs) to accomplish learning tasks in school-based settings. Specifically, we focus on two dimensions of individual differences: learning styles and individuals’ perceptions. Results suggest that individual differences do have effects on the choice of communication portfolios to accomplish tasks. In particular, we found that students who preferred to learn by hearing tended to choose the complex communication portfolio to accomplish their tasks. Interestingly, our results also indicate that students preferred to use the simple communication portfolio when communication partners were perceived to be unavailable.     

High efficiency high-speed photodetection in a monolithically integratable InGaAs/InP MQW laser structure at 1.5 mu m

Time-resolved photocurrent measurements in a reverse biased InGaAs/InP ridge waveguide multiquantum well pin laser structure at 1.54 mu m are reported. The pulse response of this monolithically integratable detector is approximately 150 ps FWHM with an internal quantum efficiency of approximately 100% at reverse bias voltages of approximately 5 V.<>     

AbiQ, an abortive infection mechanism from Lactococcus lactis

Lactococcus lactis W-37 is highly resistant to phage infection. The cryptic plasmids from this strain were coelectroporated, along with the shuttle vector pSA3, into the plasmid-free host L. lactis LM0230. In addition to pSA3, erythromycin- and phage-resistant isolates carried pSRQ900, an 11-kb plasmid from L. lactis W-37. This plasmid made the host bacteria highly resistant (efficiency of plaquing <10(-8)) to c2- and 936-like phages. pSRQ900 did not confer any resistance to phages of the P335 species. Adsorption, cell survival, and endonucleolytic activity assays showed that pSRQ900 encodes an abortive infection mechanism. The phage resistance mechanism is limited to a 2.2-kb EcoRV/BclI fragment. Sequence analysis of this fragment revealed a complete open reading frame (abiQ), which encodes a putative protein of 183 amino acids. A frameshift mutation within abiQ completely abolished the resistant phenotype. The predicted peptide has a high content of positively charged residues (pI = 10.5) and is, in all likelihood, a cytosolic protein. AbiQ has no homology to known or deduced proteins in the databases. DNA replication assays showed that phage c21 (c2-like) and phage p2 (936-like) can still replicate in cells harboring AbiQ. However, phage DNA accumulated in its concatenated form in the infected AbiQ+ cells, whereas the AbiQ- cells contained processed (mature) phage DNA in addition to the concatenated form. The production of the major capsid protein of phage c21 was not hindered in the cells harboring AbiQ.     

Physico-chemistry and cytotoxicity of ceramics

General cytotoxicity was assayed for ceramic (Al₂O₃, ZrO₂/Y₂O₃, AIN, B₄C, BN, SiC, Si₃N₄, TiB₄, TiC, TiN) diamond and graphite powders, using 3T3 Balb/c permanent cell lines. Neutral red test was carried out in order to establish cell viability. Further investigations were undertaken on human differentiated cells (human umbilical venous endothelial cells): cell behaviour (MTT assay, total cell protein content) and differentiation (immunofluorescence) were studied. In both cases, no cytotoxic effect has been noticed. All the impurities contained at low concentration in these powders do not seem to present any effect. The correlation which has been previously observed between cytotoxicity-cell culture response and blood haemolysis for polymers has not been established here for ceramic powders. We conclude that all the ceramic powders tested here and therefore the corresponding bulk ceramics or ceramic coatings do not induce any cytotoxic effect.     

Spectral-domain phase microscopy with improved sensitivity using two-dimensional detector arrays

In this work we demonstrate the use of two-dimensional detectors to improve the signal-to-noise ratio (SNR) and sensitivity in spectral-domain phase microscopy for subnanometer accuracy measurements. We show that an increase in SNR can be obtained, from 82 dB to 105 dB, using 150 pixel lines of a low-cost CCD camera as compared to a single line, to compute an averaged axial scan. In optimal mechanical conditions, phase stability as small as 92 μrad, corresponding to 6 pm displacement accuracy, could be obtained. We also experimentally demonstrate the benefit of spatial-averaging in terms of the reduction of signal fading due to an axially moving sample. The applications of the improved system are illustrated by imaging live cells in culture.     

Reproducing stone monument photosynthetic-based colonization under laboratory conditions

In order to understand the biodeterioration process occurring on stone monuments, we analyzed the microbial communities involved in these processes and studied their ability to colonize stones under controlled laboratory experiments. In this study, a natural green biofilm from a limestone monument was cultivated, inoculated on stone probes of the same lithotype and incubated in a laboratory chamber. This incubation system, which exposes stone samples to intermittently sprinkling water, allowed the development of photosynthetic biofilms similar to those occurring on stone monuments. Denaturing gradient gel electrophoresis (DGGE) analysis was used to evaluate the major microbial components of the laboratory biofilms. Cyanobacteria, green microalgae, bacteria and fungi were identified by DNA-based molecular analysis targeting the 16S and 18S ribosomal RNA genes. The natural green biofilm was mainly composed by the Chlorophyta Chlorella, Stichococcus, and Trebouxia, and by Cyanobacteria belonging to the genera Leptolyngbya and Pleurocapsa. A number of bacteria belonging to Alphaproteobacteria, Bacteroidetes and Verrucomicrobia were identified, as well as fungi from the Ascomycota. The laboratory colonization experiment on stone probes showed a colonization pattern similar to that occurring on stone monuments. The methodology described in this paper allowed to reproduce a colonization equivalent to the natural biodeteriorating process.     

Development of a Sensitive Microarray Platform for the Ranking of Galectin Inhibitors: Identification of a Selective Galectin‐3 Inhibitor

Glycan microarrays are useful tools for lectin glycan profiling. The use of a glycan microarray based on evanescent‐field fluorescence detection was herein further extended to the screening of lectin inhibitors in competitive experiments. The efficacy of this approach was tested with 2/3′‐mono‐ and 2,3′‐diaromatic type II lactosamine derivatives and galectins as targets and was validated by comparison with fluorescence anisotropy proposed as an orthogonal protein interaction measurement technique. We showed that subtle differences in the architecture of the inhibitor could be sensed that pointed out the preference of galectin‐3 for 2′‐arylamido derivatives over ureas, thioureas, and amines and that of galectin‐7 for derivatives bearing an α substituent at the anomeric position of glucosamine. We eventually identified a diaromatic oxazoline as a highly specific inhibitor of galectin‐3 versus galectin‐1 and galectin‐7.