A cloud-based recommendation service using principle component analysis–scale-invariant feature transform algorithm

Cloud computing delivers resources such as software, data, storage and servers over the Internet; its adaptable infrastructure facilitates on-demand access of computational resources. There are many benefits of cloud computing such as being scalable, paying only for consumption, improving accessibility, limiting investment costs and being environmentally friendly. Thus, many organizations have already started applying this technology to improve organizational efficiency. In this study, we developed a cloud-based book recommendation service that uses a principle component analysis–scale-invariant feature transform (PCA-SIFT) feature detector algorithm to recommend book(s) based on a user-uploaded image of a book or collection of books. The high dimensionality of the image is reduced with the help of a principle component analysis (PCA) pre-processing technique. When the mobile application user takes a picture of a book or a collection of books, the system recognizes the image(s) and recommends similar books. The computational task is performed via the cloud infrastructure. Experimental results show the PCA-SIFT-based cloud recommendation service is promising; additionally, the application responds faster when the pre-processing technique is integrated. The proposed generic cloud-based recommendation system is flexible and highly adaptable to new environments.

     

Do People Really Experience Information Overload While Reading Online Reviews?

Online consumer reviews have become a substantial component of e-commerce and provide online shoppers with abundant information about products. However, previous studies provided mixed results about whether consumers experience information overload from such a vast volume of reviews. Thus, this study investigates how users perceive products depending on various numbers of reviews (from 0 to 3,000 reviews) and different review valences (generally positive, generally negative, and divided). Two crowdsourced studies with 1,783 participants were conducted. The study found no clear evidence to suggest that information overload increases as the number of reviews increases. Instead, the participants relied on a very limited number of reviews in making purchase decisions. In addition, it was observed that the review valence affected how the participants used different information sources from the interface. Based on the results, this article provides a set of interesting implications and design guidelines.     

SVM-based posture identification with a single waist-located triaxial accelerometer

Analysis of human body movement is an important research area, specially for health applications. In order to assess the quality of life of people with mobility problems like Parkinson’s disease o stroke patients, it is crucial to monitor and assess their daily life activities. The main goal of this work is the characterization of basic activities using a single triaxial accelerometer located at the waist. This paper presents a novel postural detection algorithm based in SVM methods which is able to detect and identify Walking, Stand, Sit, Lying, Sit to Stand, Stand to sit, Bending up/down, Lying from Sit and Sit from Lying transitions with a sensitivity of 97% and specificity of 84% with 2884 postures analyzed from 31 healthy volunteers. Parameters and models found have been tested in another dataset from Parkinson’s disease patients, achieving results of 98% of sensitivity and 78% of specificity in postural transitions. The proposed algorithm has been optimized to be easily implemented in real-time system for on-line monitoring applications.     

Effect of welding procedure on the properties of microalloyed steel-welded joints for metal piping

The objective of this work was, in the first step, to compare the mechanical properties and microstructure of the corrosion-resistant steel hydrogen-induced cracking, alloyed with Nb–Ti–Cu–Ni, to those of a normal steel NOR, microalloyed with Nb–V–Ti, characterized through chemical analysis, hardness measurements, metallographic studies and tensile and Charpy-V properties. The preheating temperature was established using Tekken tests at different temperatures, according to the JIS Z 3158 standard. Circumferential welds were carried out on piping manufactured from both steels, designing procedures for the use of coated electrodes on the one hand (shielded metal arc welding, with electrodes from various suppliers) for all passes, and for a first pass using automatic welding with low-CO₂ solid wire on the other (gas–metal arc welding) and the rest with self-shielding tubular wire (flux-cored arc welding, self-shielding). The welds were classified in accordance with the API Code 1104. The results of the metallographic analysis and the mechanical traction, hardness and impact tests of the welded joints revealed the influence of the welding consumables and of the base metal on the properties of the joints. Differences were observed between the properties of the joints welded with consumables of equal specification and different suppliers. From the different combinations tested, optimum values for the welding of these steels were defined.     

Trichothecene genotypes and chemotypes in Fusarium graminearum complex strains isolated from maize fields of northwest Argentina

Members of the Fusarium graminearum species complex (Fg complex) cause Gibberella ear rot in maize from northwest Argentina. The potential of these pathogens to contaminate maize grains with type B trichothecenes is a health risk for both humans and animals. We evaluated the reliability of multiplex PCR assays based on TRI3 and TRI12 genes, and single PCR assays based on TRI7 and TRI13 genes to infer trichothecene chemotypes of 112 strains of Fg complex collected from northwest Argentina, checking trichothecene production by chemical analysis. Single and multiplex PCR assays indicated that strains belonging to F. meridionale (87/112) had a NIV genotype. The remainder strains (25/112), which belonged to F. boothii, had a DON genotype (based on single PCR assays) or 15ADON genotype (based on multiplex PCR assays). No strains tested were incorrectly diagnosed with a DON/NIV genotype. Chemical analysis indicated that the F. meridionale strains were NIV producers only (44/87), major NIV producers with unexpected high DON/NIV ratios (36/87), or unexpected major DON producers with minor NIV production (7/87). Strains with atypical DON/NIV production seem to be new phenotypes under a putative NIV genotype, since PCR assays do not provide evidences of a new trichothecene genotype. DON production and absence of its acetylated forms were shown for strains of F. boothii. The inconsistencies between genetic and chemical data highlight the risk of inferring the trichothecenes potentially contaminating food and feedstuffs based only on PCR assays. This study confirms for the first time that strains of Fg complex from maize of northwest Argentina are DON and NIV producers. In addition, dominance of NIV producers in the Fg complex population isolated from maize is unprecedented in Argentina, and of significant concern to food safety and animal production.     

Favorable response to intravenous methylprednisolone and cyclophosphamide in children with severe neuropsychiatric lupus

OBJECTIVE: To evaluate the effect of intravenous methylprednisolone (IVMP) and cyclophosphamide (IVCy) in children with severe neuropsychiatric (NP) systemic lupus erythematosus (NPSLE). METHODS: We studied 7 consecutive pediatric patients with severe NPSLE. All patients were treated initially with IVMP and IVCy followed by monthly IVCy for at least 3 months, and then every 2 and/or 3 months according to clinical response. Prednisone was given at 1-2 mg/kg during the first month. Laboratory studies included routine laboratory tests, antinuclear antibodies, anti-dsDNA, antiphospholipid antibodies, and complement components C3 and C4. Neurodiagnostic studies included cerebrospinal fluid, magnetic resonance imaging, computed tomography scanning, single photon emission computed tomography and electroencephalography. RESULTS: Three patients had organic brain syndrome with psychosis, 3 had seizures, 1 stroke, 1 cerebral vasculitis, 1 optic neuritis, and 1 transverse myelitis. In 3 of these cases, nervous system involvement was the initial presentation of SLE. Five patients had 2 or more NP manifestations. Most of them were accompanied by general SLE activity. Anticardiolipin antibodies were positive in 3 patients and none was anticoagulated. All patients improved, 6 patients had a complete recovery and 1 patient recovered with minor neurological deficit. All but one improved significantly within the first week of combined IVMP and IVCy. The mean time of follow-up was 37 months (range 8-55). IVCy was well tolerated with minimal side effects. CONCLUSION: Early aggressive treatment with combined IVMP and IVCy followed by monthly IVCy may be an effective therapy for severe NPSLE in children.     

Sample movement optimization for uniform heating in microwave heating ovens

A technique for improving the uniformity of heating patterns of dielectric samples in a multimode cavity is presented based on a strategic movement of the sample inside the microwave applicator. Different optimization algorithms are compared to determine the best microwave irradiation period for each sample position. A new optimization procedure that minimizes electric field variance is also presented and assessed. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.     

Interferon treatment of chronic hepatitis C in human immunodeficiency virus infected patients]

There are no reports to date of entire gene sequences coding for chitinolytic enzymes from entomopathogenic fungi, even though these enzymes act synergistically with proteolytic enzymes to solubilize insect cuticle during the key step of host penetration, having considerable importance in the biological control of some insect pests. This paper reports the complete nucleotide sequence and analysis of the chromosomal and full-length cDNA copies of the regulated gene (chit1) coding one of the chitinases produced by the biocontrol agent Metarhizium anisopliae. Degenerated primers, encompassing conserved regions of other fungal chitinases, were used to amplify a 650-bp DNA fragment, which was used to isolate genomic and cDNA clones from M. anisopliae. Albeit at least two different chitinases are characterized in this fungus, only one chit gene was isolated. The chit1 gene is interrupted by three short typical fungal introns and has a 1,521-bp ORF, which encodes a protein of 423 amino acids with a stretch of 35 amino acid residues displaying characteristics of signal peptide. The deduced sequence of the mature protein predicts a 42-kDa protein with pI of 5.8. Southern analysis of genomic DNA indicates a single copy of chit1 in the M. anisopliae genome.     

Study and modulation of human cortical excitability with transcranial magnetic stimulation

Transcranial magnetic stimulation (TMS) can be applied in different paradigms to obtain a measure of various aspects of cortical excitability. These different TMS paradigms provide information about different neurotransmitter systems, enhance our understanding about the pathophysiology of neuropsychiatric conditions, and in the future may be helpful as a guide for pharmacological interventions. In addition, repetitive TMS (rTMS) modulates cortical excitability beyond the duration of the rTMS trains themselves. Depending on rTMS parameters, a lasting inhibition or facilitation of cortical excitability can be induced. These effects can be demonstrated neurophysiologically or by combining rTMS with neuroimaging techniques. The effects do not remain limited to the cortical area directly targeted by rTMS, but affect a wider neural network transynaptically. Modulation of cortical excitability by rTMS may in the future be useful not only as a research tool but also as a therapeutic intervention in neurology, psychiatry, and neurorehabilitation.