Risk knowledge,product knowledge,and brand benefits for purchase intentions: Experiences with air purifiers against city smog in China

The present study is based on the theoretical framework of protective action decision model. This study aims to explain the relationship among the risk knowledge, product knowledge, risk perception, and brand benefits and the consumers’ purchase intentions of a specific air purifier compared with alternative brands. The research context is city smog. Results show that consumers’ risk knowledge and product knowledge significantly affect their purchase of an air purifier brand as well as play a considerable role in predicting their risk perception and in foreseeing their purchase intentions under the influence of the manufacturer's advertising strategies. Furthermore, consumers’ risk perception is a critical psychological factor that has a significantly positive influence on brand's experiential benefits, instead of functional and symbolic benefits. In particular, when comparing with brand's functional and symbolic benefits, the brand's experiential benefits is more attractive to consumers and has a stronger effect on consumers’ air purifier purchase intentions in the context of city smog.     

Parasitism and fitness of invaders: oligochaete Chaetogaster limnaei produces gill damage and increased respiration rates in freshwater Asian clams

Biological interactions between invasive and resident species are perceived as a key factor mediating impacts in invaded ecosystems, although symbiotic interactions have received relatively little attention. To evaluate the association between the invasive clam Corbicula fluminea and its oligochaete symbiont Chaetogaster limnaei, we conducted laboratory assessments of prevalence and intensity of infection, external and internal macroscopic alterations, and histological analyses of the gills of uninfected and infected clams collected from the shores of the Río de la Plata estuary in Argentina. To evaluate potential ramifications of physical alterations on physiological traits and host fitness, we conducted respiration experiments on the same clams. Worm prevalence was higher in smaller than large clams. While no macroscopical alterations were detected, several histopathological changes were observed in the gills of infected clams. Infected clams had significantly higher metabolic rates than uninfected conspecifics and smaller clams had higher metabolic rates than larger conspecifics. Increased host metabolic rates, even at very low infections intensities, were likely a compensatory response to the stress caused by gill damaged inflicted by the oligochaetes. The relationship between C. limnaei and invasive C. fluminea in Río de la Plata best fits as parasitism.

     

Accumulation of acyclic polyols and trehalose as related to growth form and carbohydrate source in the dimorphic fungi Mucor rouxii and Candida albicans

Yeast (Y) and hyphal (H) cells of Mucor rouxii and Candida albicans were cultivated in liquid media containing different carbon nutrient sources (glucose, fructose, ribose), and their free acyclic polyol and trehalose contents determined using capillary gas liquid chromatography (TMS- and OAc-derivatization). Irrespective of growth form and C-source, the fraction of the water-soluble neutral components of the cellular mass of the cultures — highly homogeneous with regard to the respective cell form produced — contained glycerol, ribitol and arabitol, in addition to trehalose. The polyols contributed 0.5–2% to the biomass of M. rouxii and 1.5–6% to that of C. albicans; the values for trehalose ranged from 0.2–11% in the former and 1–3.5% in the latter species. Mucor contained higher amounts of ribitol and arabitol in H cells and larger quantities of trehalose and glycerol in Y cells. In Candida, too, hyphae always exhibited higher ribitol contents, whereas arabitol attained higher levels in yeasts under almost any conditions — regardless of the type of medium (synthetic vs. complex), stage of culture (early vs. late log-phase) and strain used. Glycerol concentration was not correlated with the growth form; trehalose contents tended to be higher in Y cells. Taking into account the facts that C. albicans and certain Mucor species are agents of opportunistic infections and are invasive mainly in the filamentous form, and that the prospective hosts do not accumulate either of these carbohydrates, the possibility is considered of using trehalose- and polyol-metabolizing enzymes as targets for designing antifungal drugs.     

Morphogenesis induction and organogenic nodule differentiation in <Emphasis Type="Italic">Populus euphratica</Emphasis> Oliv. leaf explants

Populus euphratica Oliv. is a deciduous poplar species, occurring mainly in riparian areas of China and Middle Eastern countries, and presenting high tolerance to extreme temperatures and high soil salinity. In this study, an optimized protocol for development and propagation of P. euphratica from leaf explants is reported, based on a morphogenic process that involves organogenic nodule differentiation. Adventitious shoot regeneration of P. euphratica from organogenic nodules of leaf explants was achieved within a range of concentrations of α-naphtalenacetic acid and 6-benzylaminopurine, at a fixed 2:1 ratio. Cambial cells started to divide 5 days after inoculation on culture medium and, after 12 days, several organizing centres were already formed. Non-friable callus tissue, together with organization centres, formed structures that evolved to nodules after about 40 days which were, then, able to regenerate new shoots after 50–60 days. The nodules did not separate from the mother explants and were able to successfully give rise to new adventitious shoots. These were rescued and successfully grown and rooted in different culture media, and fully developed plants were obtained. The regeneration system here described for P. euphratica is innovative, reproducible and data from histological studies of the morphogenic process support the classification of the regenerative structures as organogenic nodules.     

Allantoin in human urine quantified by ultra-performance liquid chromatography-tandem mass spectrometry

Uric acid is a potent antioxidant and scavenger of singlet oxygen and other radicals in humans. Allantoin, the predominant product of free radical-induced oxidation of uric acid, is efficiently excreted in the urine and has potential as a biomarker of oxidative stress. We developed a rapid and specific assay for urinary allantoin using ultra-performance liquid chromatography-tandem mass spectrometry suitable for high-throughput clinical studies. The method required minimal sample preparation and was accurate (mean error = 6%), precise (intra- and interday imprecision <8%), and sensitive (limit of detection = 0.06 pmol). Allantoin levels measured in control samples were comparable to literature values.