The mediating role of perceived fairness in consumers’ response to post-purchase ‘out of stock’ in an online grocery context

This study investigates consumer response to a retailer’s substitution policy when facing post-purchase ‘out of stock’ (OOS) in an online grocery shopping context. Substitution policies (timeliness of OOS notification; and substituted product) can have detrimental effects on consumers’ satisfaction with the retailer and behaviour response (whether to accept or reject the substitution). As post-purchased OOS indicates a failure of service, the study focuses its investigation on the mediating effects of perceived fairness (PF) of retailers’ substitution policies on consumers’ response. It is predicted that procedural fairness will have a stronger effect on mitigating consumers’ negative OOS experience than distributive (outcome) fairness. The research will be conducted using three online scenario based experiments

Comparison of Kansei Engineering and AttrakDiff to Evaluate Kitchen Products

Kansei Engineering can be used to create scales to measure perceptions and evaluations of products in a particular context. To what extent do specifically constructed Kansei scales reveal more information about a product than a more generic, prestructured instrument, such as AttrakDiff? This case study identified relevant affective and pragmatic Kansei attributes that influence the purchase of a range hood (cooker hood). 102 customers rated the extent to which each of 10 range hoods possessed these attributes. In addition, AttrakDiff was used to measure hedonic and pragmatic quality perceptions. There was a general high correspondence between AttrakDiff and Kansei. While Kansei provided richer and more specific feedback, it was more resource intensive to carry out

The Intermediate Scale MSSM, the Higgs Mass and F-theory Unification

Even if SUSY is not present at the Electro-Weak scale, string theory suggests its presence at some scale M_{SS} below the string scale M_s to guarantee the absence of tachyons. We explore the possible value of M_{SS} consistent with gauge coupling unification and known sources of SUSY breaking in string theory. Within F-theory SU(5) unification these two requirements fix M_{SS} ~ 5 x 10^{10} GeV at an intermediate scale and a unification scale M_c ~ 3 x 10^{14} GeV. As a direct consequence one also predicts the vanishing of the quartic Higgs SM self-coupling at M_{SS} ~10^{11} GeV. This is tantalizingly consistent with recent LHC hints of a Higgs mass in the region 124-126 GeV. With such a low unification scale M_c ~ 3 x 10^{14} GeV one may worry about too fast proton decay via dimension 6 operators. However in the F-theory GUT context SU(5) is broken to the SM via hypercharge flux. We show that this hypercharge flux deforms the SM fermion wave functions leading to a suppression, avoiding in this way the strong experimental proton decay constraints. In these constructions there is generically an axion with a scale of size f_a ~ M_c/(4\pi)^2 ~ 10^{12} GeV which could solve the strong CP problem and provide for the observed dark matter. The prize to pay for these attractive features is to assume that the hierarchy problem is solved due to anthropic selection in a string landscape.Comment: 48 pages, 8 figures. v3: further minor correction

The association between histamine 2 receptor antagonist use and Clostridium difficile infection: a systematic review and meta-analysis.

Background Clostridium difficile infection (CDI) is a major health problem. Epidemiological evidence suggests that there is an association between acid suppression therapy and development of CDI. Purpose We sought to systematically review the literature that examined the association between histamine 2 receptor antagonists (H2RAs) and CDI. Data source We searched Medline, Current Contents, Embase, ISI Web of Science and Elsevier Scopus from 1990 to 2012 for all analytical studies that examined the association between H2RAs and CDI. Study selection Two authors independently reviewed the studies for eligibility. Data extraction Data about studies characteristics, adjusted effect estimates and quality were extracted. Data synthesis Thirty-five observations from 33 eligible studies that included 201834 participants were analyzed. Studies were performed in 6 countries and nine of them were multicenter. Most studies did not specify the type or duration of H2RAs therapy. The pooled effect estimate was 1.44, 95% CI (1.22–1.7), I2 = 70.5%. This association was consistent across different subgroups (by study design and country) and there was no evidence of publication bias. The pooled effect estimate for high quality studies was 1.39 (1.15–1.68), I2 = 72.3%. Meta-regression analysis of 10 study-level variables did not identify sources of heterogeneity. In a speculative analysis, the number needed to harm (NNH) with H2RAs at 14 days after hospital admission in patients receiving antibiotics or not was 58, 95% CI (37, 115) and 425, 95% CI (267, 848), respectively. For the general population, the NNH at 1 year was 4549, 95% CI (2860, 9097). Conclusion In this rigorous systematic review and meta-analysis, we observed an association between H2RAs and CDI. The absolute risk of CDI associated with H2RAs is highest in hospitalized patients receiving antibiotics

Optimising biocatalyst design for obtaining high transesterification activity by α-chymotrypsin in non-aqueous media

<p>Abstract</p> <p>Background</p> <p>Enzymes are often used in organic solvents for catalyzing organic synthesis. Two enzyme preparations, EPRP (enzyme precipitated and rinsed with n-propanol) and PCMC (protein coated microcrystals) show much higher activities than lyophilized powders in such systems. Both preparations involve precipitation by an organic solvent. The clear understanding of why these preparations show higher catalytic activity than lyophilized powders in organic solvents is not available.</p> <p>Results</p> <p>It was found that EPRPs of α-chymotrypsin prepared by precipitation with <it>n</it>-propanol in the presence of trehalose contained substantial amount of trehalose (even though trehalose alone at these lower concentrations was not precipitated by <it>n</it>-propanol). The presence of trehalose in these EPRPs resulted in much higher transesterification rates (45.2 nmoles mg^-1min^-1) as compared with EPRPs prepared in the absence of trehalose (16.6 nmoles mg^-1min^-1) in octane. Both kinds of EPRPs gave similar initial transesterification rates in acetonitrile. Use of higher concentrations of trehalose (when trehalose alone also precipitates out), resulted in the formation of PCMCs, which showed higher transesterification rates in both octane and acetonitrile. SEM analysis showed the relative sizes of various preparations. Presence of trehalose resulted in EPRPs of smaller sizes.</p> <p>Conclusion</p> <p>The two different forms of enzymes (EPRP and PCMC) known to show higher activity in organic solvents were found to be different only in the way the low molecular weight additive was present along with the protein. Therefore, the enhancement in the transesterification activity in EPRPs prepared in the presence of trehalose was due to: (a) better retention of essential water layer for catalysis due to the presence of the sugar. This effect disappeared where the reaction media was polar as the polar solvent (acetonitrile) is more effective in stripping off the water from the enzyme; (b) reduction in particle size as revealed by SEM. In the case of PCMC, the enhancement in the initial rates was due to an increase in the surface area of the biocatalyst since protein is coated over the core material (trehalose or salt).</p> <p>It is hoped that the insight gained in this work would help in a better understanding for designing high activity biocatalyst preparation of non-aqueous media.</p

Direct cooling of the catheter tip increases safety for CMR-guided electrophysiological procedures

<p>Abstract</p> <p>Background</p> <p>One of the safety concerns when performing electrophysiological (EP) procedures under magnetic resonance (MR) guidance is the risk of passive tissue heating due to the EP catheter being exposed to the radiofrequency (RF) field of the RF transmitting body coil. Ablation procedures that use catheters with irrigated tips are well established therapeutic options for the treatment of cardiac arrhythmias and when used in a modified mode might offer an additional system for suppressing passive catheter heating.</p> <p>Methods</p> <p>A two-step approach was chosen. Firstly, tests on passive catheter heating were performed in a 1.5 T Avanto system (Siemens Healthcare Sector, Erlangen, Germany) using a ASTM Phantom in order to determine a possible maximum temperature rise. Secondly, a phantom was designed for simulation of the interface between blood and the vascular wall. The MR-RF induced temperature rise was simulated by catheter tip heating via a standard ablation generator. Power levels from 1 to 6 W were selected. Ablation duration was 120 s with no tip irrigation during the first 60 s and irrigation at rates from 2 ml/min to 35 ml/min for the remaining 60 s (Biotronik Qiona Pump, Berlin, Germany). The temperature was measured with fluoroscopic sensors (Luxtron, Santa Barbara, CA, USA) at a distance of 0 mm, 2 mm, 4 mm, and 6 mm from the catheter tip.</p> <p>Results</p> <p>A maximum temperature rise of 22.4°C at the catheter tip was documented in the MR scanner. This temperature rise is equivalent to the heating effect of an ablator's power output of 6 W at a contact force of the weight of 90 g (0.883 N). The catheter tip irrigation was able to limit the temperature rise to less than 2°C for the majority of examined power levels, and for all examined power levels the residual temperature rise was less than 8°C.</p> <p>Conclusion</p> <p>Up to a maximum of 22.4°C, the temperature rise at the tissue surface can be entirely suppressed by using the catheter's own irrigation system. The irrigated tip system can be used to increase MR safety of EP catheters by suppressing the effects of unwanted passive catheter heating due to RF exposure from the MR scanner.</p

Organ transplantation from deceased donors with vaccine-induced thrombosis and thrombocytopenia

Vaccine-induced thrombosis and thrombocytopenia (VITT) may follow immunisation with the ChAdOx1 nCoV-19 vaccine against SARS-CoV-2. Autoantibodies to platelet factor 4 (PF4) may mediate VITT through antibody-dependent platelet activation, though the underlying etiology is uncertain. Anti-PF4 antibodies are also seen in heparin-induced thrombocytopenia, though most cases of VITT do not have prior heparin exposure. More than 20 million people in the United Kingdom (UK) have received the ChAdOx1 nCoV-19 vaccine

The rph1 Gene Is a Common Contributor to the Evolution of Phosphine Resistance in Independent Field Isolates of Rhyzopertha Dominica

Phosphine is the only economically viable fumigant for routine control of insect pests of stored food products, but its continued use is now threatened by the world-wide emergence of high-level resistance in key pest species. Phosphine has a unique mode of action relative to well-characterised contact pesticides. Similarly, the selective pressures that lead to resistance against field sprays differ dramatically from those encountered during fumigation. The consequences of these differences have not been investigated adequately. We determine the genetic basis of phosphine resistance in Rhyzopertha dominica strains collected from New South Wales and South Australia and compare this with resistance in a previously characterised strain from Queensland. The resistance levels range from 225 and 100 times the baseline response of a sensitive reference strain. Moreover, molecular and phenotypic data indicate that high-level resistance was derived independently in each of the three widely separated geographical regions. Despite the independent origins, resistance was due to two interacting genes in each instance. Furthermore, complementation analysis reveals that all three strains contain an incompletely recessive resistance allele of the autosomal rph1 resistance gene. This is particularly noteworthy as a resistance allele at rph1 was previously proposed to be a necessary first step in the evolution of high-level resistance. Despite the capacity of phosphine to disrupt a wide range of enzymes and biological processes, it is remarkable that the initial step in the selection of resistance is so similar in isolated outbreaks