931 research outputs found
The Dynamics of Store Hour Changes and Consumption Behavior: Results of a Longitudinal Study of Consumer Attitudes toward Saturday Shopping in Germany
Americans who travel internationally are often shocked to discover retail outlets closed during weekend and evening hours in cities such as Paris, Rome and Berlin. Fortunately, based on the implicit assumption that demand clearly exists, retailers at various locations throughout the globe have increased their hours of operation. While political debate regarding a variety of issues (costs, the rights of labor, religion, etc.) often rages, there has been an implicit assumption that latent demand for longer hours of operation exists. Our study investigates through a longitudinal examination consumer perceptions of Saturday shopping in a country where such an activity was previously restricted. Specifically, we study perceptions of Saturday shopping among a sample of German college students who were raised with limited Saturday shopping hours. Data were gathered in 1996 – the year German legislation allowed expanded hours for retailers – and again in 1999, and comparisons are made. Strong differences are found between consumer attitudes towards Saturday shopping at the time of expansion and three years later, indicating the need for differentiating retail strategies in Germany and in other parts of the world that may soon be providing similar expanded retail access.Agribusiness,
Mosaics of canopy openness induced by tropical cyclones in lowland rain forests with contrasting management histories in northeastern Australia
Tropical Cyclone 'Rona' crossed the coast of the Daintree lowlands of northeastern Australia in 1999. This study reports on its impact on forest canopy openness at six lowland rain forest sites with contrasting management histories (old-growth, selectively logged and regrowth). Percentage canopy openness was calculated from individual hemispherical photographs taken from marked points below the forest canopy at nine plots per site 3±4 mo before the cyclone, and at the same points a month afterwards. Before the cyclone, when nine sites were visited, canopy openness in old-growth and logged sites was similar, but significantly higher in regrowth forest. After the cyclone, all six revisited sites showed an increase in canopy openness, but the increase was very patchy amongst plots and sites and varied from insignificant to severe. The most severely impacted site was an old-growth one, the least impacted a logged one. Although proneness to impact was apparently related to forest management history (old-growth being the most impacted), underlying local topography may have had an equally strong influence in this case. It was concluded that the likelihood of severe impact may be determined at the landscape-scale by the interaction of anthropogenic with meteorological, physiographic and biotic factors. In the long term, such interactions may caution against pursuing forest management in cyclone-prone areas
Investigating the Portrayal and Influence of Sustainability Claims in an Environmental Advertising Context
The ability of consumer judges to identify sustainable messages in environmental advertising and the effect of these messages is explored. A content analysis provides insight into these judges’ perceptions of the depth of environmental advertising messages. An experiment investigates the influence of sustainable messages and includes collection of cognitive response data to evaluate the cognitive dimension of sustainability messages. Content analysis results suggest that sustainability messages may influence how environmental advertisements are perceived. These findings are supported by the cognitive response data, which shows cognitive differences across advertisements, and the experimental manipulation that suggests sustainable ads may be more involving to consumers
A subduction origin for komatites and cratonic lithospheric mantle
We present a model in which the generation of komatiites in Archaean subduction zones produced depleted mantle residues that eventually formed the highly depleted portions of the Kaapvaal lithospheric mantle. The envisioned melting process is similar to that which has formed boninites in Phanerozoic subduction zones such as the Izu-Bonin-Mariana arc. The primary differences between the Archaean and Phanerozoic melting regimes are higher mean melting temperatures (1450 versus 1350 °C) and higher mean melting pressures (2.5 versus 1.5 GPa) for the komatiites. The komatiites from the Komati Formation in the Barberton greenstone belt are mafic enough to have produced the depletion seen in most Kaapvaal granular peridotite xenoliths. However, the most highly depleted Kaapvaal xenoliths require an even more Mg-rich magma than the Komati komatiites (Kk). Samples of boninite mantle residues from the fore-arc of the Marianas subduction zone are nearly as depleted as the Kaapvaal cratonic mantle, indicating that buoyant, craton-like mantle is being produced today. We speculate that production rates of cratonic mantle were greater in the Archaean due to the greater depth of melting for komatiites (relative to boninites) and greater worldwide arc length. The high production rates and high buoyancy of the komatiite mantle residues gave rise to the rapid growth and stabilization of the Kaapvaal craton in the Archaean
Multiple effects of silymarin on the hepatitis C virus lifecycle
Silymarin, an extract from milk thistle (Silybum marianum), and its purified flavonolignans have been recently shown to inhibit hepatitis C virus (HCV) infection, both in vitro and in vivo. In the current study, we further characterized silymarin's antiviral actions. Silymarin had antiviral effects against hepatitis C virus cell culture (HCVcc) infection that included inhibition of virus entry, RNA and protein expression, and infectious virus production. Silymarin did not block HCVcc binding to cells but inhibited the entry of several viral pseudoparticles (pp), and fusion of HCVpp with liposomes. Silymarin but not silibinin inhibited genotype 2a NS5B RNA-dependent RNA polymerase (RdRp) activity at concentrations 5 to 10 times higher than required for anti-HCVcc effects. Furthermore, silymarin had inefficient activity on the genotype 1b BK and four 1b RDRPs derived from HCV-infected patients. Moreover, silymarin did not inhibit HCV replication in five independent genotype 1a, 1b, and 2a replicon cell lines that did not produce infectious virus. Silymarin inhibited microsomal triglyceride transfer protein activity, apolipoprotein B secretion, and infectious virion production into culture supernatants. Silymarin also blocked cell-to-cell spread of virus. CONCLUSION: Although inhibition of in vitro NS5B polymerase activity is demonstrable, the mechanisms of silymarin's antiviral action appear to include blocking of virus entry and transmission, possibly by targeting the host cell
Coordinated regulation of transcription by CcpA and the \u3ci\u3eStaphylococcus aureus\u3c/i\u3e twocomponent system HptRS
The success of Staphylococcus aureus as a pathogen is due in part to its ability to adapt to changing environmental conditions using signal transduction pathways, such as metaboliteresponsive regulators and two-component systems. S. aureus has a two-component system encoded by the gene pair sav0224 (hptS) and sav0223 (hptR) that regulate the hexose phosphate transport (uhpT) system in response to extracellular glucose-6-phosphate. Glycolytic intermediates such as glucose-6-phosphate are important carbon sources that also modulate the activity of the global metabolite-responsive transcriptional regulator CcpA. Because uhpT has a putative CcpA binding site in its promoter and it is regulated by HptR, it was hypothesized the regulons of CcpA and HptR might intersect. To determine if the regulatory domains of CcpA and HptRS overlap, ccpA was deleted in strains SA564 and SA564- ΔhptRS and growth, metabolic, proteomic, and transcriptional differences were assessed. As expected, CcpA represses hptS and hptR in a glucose dependent manner; however, upon CcpA derepression, the HptRS system functions as a transcriptional activator of metabolic genes within the CcpA regulon. Importantly, inactivation of ccpA and hptRS altered sensitivity to fosfomycin and ampicillin in the absence of exogenous glucose-6-phosphate, indicating that both CcpA and HptRS modulate antibiotic susceptibility
Structures of the Hepaci-, Pegi-, and Pestiviruses envelope proteins suggest a novel membrane fusion mechanism
Enveloped viruses encode specialised glycoproteins that mediate fusion of viral and host membranes. Discovery and understanding of the molecular mechanisms of fusion have been achieved through structural analyses of glycoproteins from many different viruses, and yet the fusion mechanisms of some viral genera remain unknown. We have employed systematic genome annotation and AlphaFold modelling to predict the structures of the E1E2 glycoproteins from 60 viral species in the Hepacivirus, Pegivirus, and Pestivirus genera. While the predicted structure of E2 varied widely, E1 exhibited a very consistent fold across genera, despite little or no similarity at the sequence level. Critically, the structure of E1 is unlike any other known viral glycoprotein. This suggests that the Hepaci-, Pegi-, and Pestiviruses may possess a common and novel membrane fusion mechanism. Comparison of E1E2 models from various species reveals recurrent features that are likely to be mechanistically important and sheds light on the evolution of membrane fusion in these viral genera. These findings provide new fundamental understanding of viral membrane fusion and are relevant to structure-guided vaccinology
Quantum Optics and Photonics
Contains table of contents for Part II, table of contents for Section 1 and reports on six research projects.U.S. Air Force - Electronic Systems Division Contract F19628-92-K-0013U.S. Navy - Office of Naval Research Grant N0014-91-J-1808Ballistic Missile Defense Organization Grant NG0921-94-C-0101MIT Plasma Fusion Cente
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Identification of rare-disease genes using blood transcriptome sequencing and large control cohorts.
It is estimated that 350 million individuals worldwide suffer from rare diseases, which are predominantly caused by mutation in a single gene1. The current molecular diagnostic rate is estimated at 50%, with whole-exome sequencing (WES) among the most successful approaches2-5. For patients in whom WES is uninformative, RNA sequencing (RNA-seq) has shown diagnostic utility in specific tissues and diseases6-8. This includes muscle biopsies from patients with undiagnosed rare muscle disorders6,9, and cultured fibroblasts from patients with mitochondrial disorders7. However, for many individuals, biopsies are not performed for clinical care, and tissues are difficult to access. We sought to assess the utility of RNA-seq from blood as a diagnostic tool for rare diseases of different pathophysiologies. We generated whole-blood RNA-seq from 94 individuals with undiagnosed rare diseases spanning 16 diverse disease categories. We developed a robust approach to compare data from these individuals with large sets of RNA-seq data for controls (n = 1,594 unrelated controls and n = 49 family members) and demonstrated the impacts of expression, splicing, gene and variant filtering strategies on disease gene identification. Across our cohort, we observed that RNA-seq yields a 7.5% diagnostic rate, and an additional 16.7% with improved candidate gene resolution
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