Content Analysis of Scarcity Promotional Messages

Scarcity refers to the limited supply of a commodity, a fundamental concept in economics (Lynn, 2008). Scarcity promotions have been frequently utilized in the marketplace, and their persuasive power has been acknowledged by both practitioners and academics (Gierl & Huettl, 2010). According to the commodity theory (Brock, 1968), a limited availability of goods, services, or opportunities influences consumers‟ perceived scarcity and results in purchase intention by influencing consumer value perceptions (Lynn, 1989)

Average-Case Optimal Approximate Circular String Matching

Approximate string matching is the problem of finding all factors of a text t of length n that are at a distance at most k from a pattern x of length m. Approximate circular string matching is the problem of finding all factors of t that are at a distance at most k from x or from any of its rotations. In this article, we present a new algorithm for approximate circular string matching under the edit distance model with optimal average-case search time O(n(k + log m)/m). Optimal average-case search time can also be achieved by the algorithms for multiple approximate string matching (Fredriksson and Navarro, 2004) using x and its rotations as the set of multiple patterns. Here we reduce the preprocessing time and space requirements compared to that approach

Polyploidy levels of Chinese large-flower chrysanthemum determined by flow cytometry

Flow cytometry was used to determine the ploidy level of 405 Chinese large-flower chrysanthemum (Chrysanthemum morifolium Ramat.) cultivars. Sixty-three cultivars are triploid, 175 cultivars tetraploid, 32 cultivars pentaploid, 46 cultivars hexaploid and 1 cultivar heptaploid. Forty-eight cultivars were then randomly selected for confirmation by chromosome-counting; the results are in agreement with the classification of ploidy level by flow cytometry. Most cultivars are aneuploid. The high percentage of tetraploid and triploid, instead of hexaploid in previous studies, represents the first evidence of low ploidy in large-flower chrysanthemum, which indicated a wider range of ploidy variation in this population. The results also offer further insights to the possible evolution and the regulation of flower size of this large-flower population. Additionally, the combination of flow cytometry and chromosome-counting is proved to be efficient and necessary for large-scale ploidy screening of chrysanthemum.Keywords: Chrysanthemum, ploidy level, flow cytometr

A novel sulfonamide resistance mechanism by two-component flavin-dependent monooxygenase system in sulfonamide-degrading actinobacteria

Sulfonamide-degrading bacteria have been discovered in various environments, suggesting the presence of novel resistance mechanisms via drug inactivation. In this study, Microbacterium sp. CJ77 capable of utilizing various sulfonamides as a sole carbon source was isolated from a composting facility. Genome and proteome analyses revealed that a gene cluster containing a flavin-dependent monooxygenase and a flavin reductase was highly up-regulated in response to sulfonamides. Biochemical analysis showed that the two-component monooxygenase system was key enzymes for the initial cleavage of sulfonamides. Co-expression of the two-component system in Escherichia coli conferred decreased susceptibility to sulfamethoxazole, indicating that the genes encoding drug-inactivating enzymes are potential resistance determinants. Comparative genomic analysis revealed that the gene cluster containing sulfonamide monooxygenase (renamed as sulX) and flavin reductase (sulR) was highly conserved in a genomic island shared among sulfonamide-degrading actinobacteria, all of which also contained sul1-carrying class 1 integrons. These results suggest that the sulfonamide metabolism may have evolved in sulfonamide-resistant bacteria which had already acquired the class 1 integron under sulfonamide selection pressures. Furthermore, the presence of multiple insertion sequence elements and putative composite transposon structures containing the sulX gene cluster indicated potential mobilization. This is the first study to report that sulX responsible for both sulfonamide degradation and resistance is prevalent in sulfonamide-degrading actinobacteria and its genetic signatures indicate horizontal gene transfer of the novel resistance gene

Mobile resistome of human gut and pathogen drives anthropogenic bloom of antibiotic resistance

BACKGROUND:The impact of human activities on the environmental resistome has been documented in many studies, but there remains the controversial question of whether the increased antibiotic resistance observed in anthropogenically impacted environments is just a result of contamination by resistant fecal microbes or is mediated by indigenous environmental organisms. Here, to determine exactly how anthropogenic influences shape the environmental resistome, we resolved the microbiome, resistome, and mobilome of the planktonic microbial communities along a single river, the Han, which spans a gradient of human activities. RESULTS:The bloom of antibiotic resistance genes (ARGs) was evident in the downstream regions and distinct successional dynamics of the river resistome occurred across the spatial continuum. We identified a number of widespread ARG sequences shared between the river, human gut, and pathogenic bacteria. These human-related ARGs were largely associated with mobile genetic elements rather than particular gut taxa and mainly responsible for anthropogenically driven bloom of the downstream river resistome. Furthermore, both sequence- and phenotype-based analyses revealed environmental relatives of clinically important proteobacteria as major carriers of these ARGs. CONCLUSIONS:Our results demonstrate a more nuanced view of the impact of anthropogenic activities on the river resistome: fecal contamination is present and allows the transmission of ARGs to the environmental resistome, but these mobile genes rather than resistant fecal bacteria proliferate in environmental relatives of their original hosts. Video abstract

Revisiting Polymorphic Diversity of Aminoglycoside N-Acetyltransferase AAC(6′)-Ib Based on Bacterial Genomes of Human, Animal, and Environmental Origins

The prevalence of aac(6′)-Ib variants has been demonstrated in numerous epidemiological studies. We revisited the polymorphic diversity of aminoglycoside 6’-N-acetyltransferase gene [aac(6′)-Ib] in the bacterial genome databases based on One Health perspectives. aac(6′)-Ib was searched against bacterial complete and draft genome databases of NCBI. Based on the major polymorphic residues 102, 117, and 179, taxonomy, ecology, and temporal emergence of bacterial isolates harboring variants of aac(6′)-Ib gene were evaluated using whole-genome sequences available in the databases. A total of 3,964 aac(6′)-Ib sequences were found to be present in the genomes of 34 bacterial genera, mostly found in Gammaproteobacteria. Among these, aac(6′)-Ib-cr variant, known to confer fluoroquinolone resistance, were increasingly detected in bacterial genomes and most abundant in the genera Klebsiella and Escherichia, thereby suggesting that these genera were the major reservoirs of the plasmid-mediated quinolone resistance (PMQR) determinant. The proportions of the cr variant were higher in animal and environmental isolates than in human isolates, among which the variant was dominant (>50%) in the genomes of intestinal, rectal, and fecal origins. In addition, our study suggested that the prevalence of the cr variant was associated with the occurrence of a variant with the mutation L117 (IbL). An integrated surveillance system for antimicrobial resistance in human, animal, and environmental sectors, based on whole-genome sequencing, would provide a better insight into the evolution, ecology, and epidemiology of antimicrobial-resistant bacteria

ZnSe/ZnSeTe Superlattice Nanotips

The authors report the growth of ZnSe/ZnSeTe superlattice nanotips on oxidized Si(100) substrate. It was found the nanotips exhibit mixture of cubic zinc-blende and hexagonal wurtzite structures. It was also found that photoluminescence intensities observed from the ZnSe/ZnSeTe superlattice nanotips were much larger than that observed from the homogeneous ZnSeTe nanotips. Furthermore, it was found that activation energies for the ZnSe/ZnSeTe superlattice nanotips with well widths of 16, 20, and 24 nm were 76, 46, and 19 meV, respectively