1,045 research outputs found
Service quality: mind the gap!
The characteristics of service can be somewhat slippery and difficult to pin down, not least of all because any given service can only be seen through the eyes of its recipient. This is emphasised by Peters (1985) who stated that ‘customers perceive service in their own unique, idiosyncratic, emotional, irrational, end-of-the-day, and totally human terms.’ Furthermore, and as is noted by Deming (1986) compared to a customer’s reaction to the quality of manufactured goods a customer’s reaction to service quality is immediate. However, service quality, whatever it may be, and however complex a phenomena it might also be, cannot be ignored since service quality can be a key competitive differentiating factor. The SERVQUAL scale or gaps model as it has become known is a common method of measuring service quality. This paper will review the gaps model 25 years on, and make a critical evaluation and assessment of whether the model is still as appropriate in view of the current service environment being dynamic and much changed
Monte Carlo simulation of a two-field effective Hamiltonian of complete wetting
Recent work on the complete wetting transition for three dimensional systems
with short-ranged forces has emphasized the role played by the coupling of
order-parameter fluctuations near the wall and depinning interface. It has been
proposed that an effective two-field Hamiltonian, which predicts a
renormalisation of the wetting parameter, could explain the controversy between
RG analysis of the capillary-wave model and Monte Carlo simulations on the
Ising model. In this letter results of extensive Monte Carlo simulations of the
two-field model are presented. The results are in agreement with prediction of
a renormalized wetting parameter .Comment: To appear in Europhysics Letters. Latex file, 6 pages, 2 figure
Family structure and adolescent delinquency: Examining the influence of parenting and extended family support
Research regarding family structure and delinquency often suggests that adolescents from non-intact homes are associated with more delinquency than adolescents from intact homes. The influence of parenting practices on the above relationship is disputed among researchers. In addition few studies have examined the influence of extended family support. Using data from the National Youth Survey the present study examines parenting practices as a potential mediator between family structure and delinquency. Extended family support is also examined as a potential moderator between single mother families and delinquency. Results suggest that family structure is associated with certain types of delinquency. In addition parental involvement and monitoring may act as mediators between single mother families and certain types of delinquency. Finally, results suggest that extended family support may decrease the association between single mother families and certain types of delinquency and between African American adolescents and certain types of delinquency
Coupled Fluctuations near Critical Wetting
Recent work on the complete wetting transition has emphasized the role played
by the coupling of fluctuations of the order parameter at the wall and at the
depinning fluid interface. Extending this approach to the wetting transition
itself we predict a novel crossover effect associated with the decoupling of
fluctuations as the temperature is lowered towards the transition temperature
T_W. Using this we are able to reanalyse recent Monte-Carlo simulation studies
and extract a value \omega(T_W)=0.8 at T_W=0.9T_C in very good agreement with
long standing theoretical predictions.Comment: 4 pages, LaTex, 1 postscript figur
Closing the gap:how psychological distance influences willingness to engage in risky COVID behavior
Pandemics, and other risk-related contexts, require dynamic changes in behavior as situations develop. Human behavior is influenced by both explicit (cognitive) and implicit (intuitive) factors. In this study, we used psychological distance as a lens to understand what influences our decision-making with regard to risk in the context of COVID-19. This study was based on the rationale that our relational needs are more concrete to us than the risk of the virus. First, we explored the impact of social–psychological distance on participants’ risk perceptions and behavioral willingness. As hypothesized, we found that close social relationships of agents promoted willingness to engage in risky behavior. In the second phase, we tested an intervention designed to increase the concreteness of information about virus transmission as a mechanism to mitigate the bias of social influence. We found that the concreteness intervention resulted in significantly reduced willingness to engage in risky behavior. As such, communications aimed at changing the behavior of citizens during times of increased risk or danger should consider conceptually concrete messaging when communicating complex risk, and hence may provide a valuable tool in promoting health-related behavior
A point mutation in the hair cell nicotinic cholinergic receptor prolongs cochlear inhibition and enhances noise protection
The transduction of sound in the auditory periphery, the cochlea, is inhibited by efferent cholinergic neurons projecting from the brainstem and synapsing directly on mechanosensory hair cells. One fundamental question in auditory neuroscience is what role(s) this feedback plays in our ability to hear. In the present study, we have engineered a genetically modified mouse model in which the magnitude and duration of efferent cholinergic effects are increased, and we assess the consequences of this manipulation on cochlear function. We generated the Chrna9L9′T of knockin mice with a threonine for leucine change (L9′T) at position 9′ of the second transmembrane domain of the α9 nicotinic cholinergic subunit, rendering α9-containing receptors that were hypersensitive to acetylcholine and had slower desensitization kinetics. The Chrna9L9′T allele produced a 3-fold prolongation of efferent synaptic currents in vitro. In vivo, Chrna9L9′T mice had baseline elevation of cochlear thresholds and efferent-mediated inhibition of cochlear responses was dramatically enhanced and lengthened: both effects were reversed by strychnine blockade of the α9α10 hair cell nicotinic receptor. Importantly, relative to their wild-type littermates, Chrna9L9′T/L9′T mice showed less permanent hearing loss following exposure to intense noise. Thus, a point mutation designed to alter α9α10 receptor gating has provided an animal model in which not only is efferent inhibition more powerful, but also one in which sound-induced hearing loss can be restrained, indicating the ability of efferent feedback to ameliorate sound trauma.Fil: Taranda, Julian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Tufts University School of Medicine; Estados UnidosFil: Maison, Stéphane F.. Massachusetts Eye and Ear Infirmary; Estados UnidosFil: Ballestero, Jimena Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Katz, Eleonora. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Savino, Jessica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Vetter, Douglas E.. Tufts University School of Medicine; Estados UnidosFil: Boulter, Jim. University of California at Los Angeles; Estados UnidosFil: Liberman, M. Charles. Massachusetts Eye and Ear Infirmary; Estados UnidosFil: Fuchs, Paul A.. The Johns Hopkins University School of Medicine; Estados UnidosFil: Elgoyhen, Ana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Farmacología; Argentin
Targeted mutation of NOV/CCN3 in mice disrupts joint homeostasis and causes osteoarthritis-like disease
Objective
The matricellular protein NOV/CCN3, is implicated in osteoarthritis (OA) and targeted mutation of NOV in mice (Novdel3) leads to joint abnormalities. This investigation tested whether NOV is required for joint homeostasis and if its disruption causes joint degeneration.
Method
NOV expression in the adult mouse joint was characterized by immunohistochemistry. A detailed comparison of the joints of Novdel3−/− and Novdel3+/+ (wild-type) males and females at 2, 6 and 12 months of age was determined by X-ray, histology and immunohistochemistry.
Results
NOV protein was found in specific cells in articular cartilage, meniscus, synovium and ligament attachment sites in adult knees. Novdel3−/− males exhibited severe OA-like pathology at 12 months (OARSI score 5.0 ± 0.5, P < 0.001), affecting all tissues of the joint: erosion of the articular cartilage, meniscal enlargement, osteophytic outgrowths, ligament degeneration and expansion of fibrocartilage. Subchondral sclerosis and changes in extracellular matrix composition consistent with OA, were also seen. The density of articular cartilage cells in Novdel3+/+ knee joints is maintained at a constant level from 2 to 12 months of age whereas this is not the case in Novdel3−/− mice. Compared with age and sex-matched Novdel3+/+ mice, a significant increase in articular cartilage density was seen in Novdel3−/− males at 2 months, whereas a significant decrease was seen at 6 and 12 months in both Novdel3−/− males and females.
Conclusion
NOV is required for the maintenance of articular cartilage and for joint homeostasis, with disruption of NOV in ageing Novdel3−/− male mice causing OA-like disease
Surface induced disorder in body-centered cubic alloys
We present Monte Carlo simulations of surface induced disordering in a model
of a binary alloy on a bcc lattice which undergoes a first order bulk
transition from the ordered DO3 phase to the disordered A2 phase. The data are
analyzed in terms of an effective interface Hamiltonian for a system with
several order parameters in the framework of the linear renormalization
approach due to Brezin, Halperin and Leibler. We show that the model provides a
good description of the system in the vicinity of the interface. In particular,
we recover the logarithmic divergence of the thickness of the disordered layer
as the bulk transition is approached, we calculate the critical behavior of the
maxima of the layer susceptibilities, and demonstrate that it is in reasonable
agreement with the simulation data. Directly at the (110) surface, the theory
predicts that all order parameters vanish continuously at the surface with a
nonuniversal, but common critical exponent. However, we find different
exponents for the order parameter of the DO3 phase and the order parameter of
the B2 phase. Using the effective interface model, we derive the finite size
scaling function for the surface order parameter and show that the theory
accounts well for the finite size behavior of the DO3 ordering but not for that
of B2 ordering. The situation is even more complicated in the neighborhood of
the (100) surface, due to the presence of an ordering field which couples to
the B2 order.Comment: To appear in Physical Review
Effects of confinement and surface enhancement on superconductivity
Within the Ginzburg-Landau approach a theoretical study is performed of the
effects of confinement on the transition to superconductivity for type-I and
type-II materials with surface enhancement. The superconducting order parameter
is characterized by a negative surface extrapolation length . This leads to
an increase of the critical field and to a surface critical
temperature in zero field, , which exceeds the bulk . When the
sample is {\em mesoscopic} of linear size the surface induces
superconductivity in the interior for .
In analogy with adsorbed fluids, superconductivity in thin films of type-I
materials is akin to {\em capillary condensation} and competes with the
interface delocalization or "wetting" transition. The finite-size scaling
properties of capillary condensation in superconductors are scrutinized in the
limit that the ratio of magnetic penetration depth to superconducting coherence
length, , goes to zero, using analytic
calculations. While standard finite-size scaling holds for the transition in
non-zero magnetic field , an anomalous critical-point shift is found for
H=0. The increase of for H=0 is calculated for mesoscopic films,
cylindrical wires, and spherical grains of type-I and type-II materials.
Surface curvature is shown to induce a significant increase of ,
characterized by a shift inversely proportional to the
radius .Comment: 37 pages, 5 figures, accepted for PR
Next generation of ALDH substrates and their potential to study maturational lineage biology in stem and progenitor cells
High aldehyde dehydrogenase (ALDH) activity is a feature of stem cells from normal and cancerous tissues and a reliable universal marker used to isolate them. There are numerous ALDH isoforms with preferred substrate specificity variably expressed depending on tissue, cell type, and organelle and cell status. On the other hand, a given substrate may be metabolized by several enzyme isoforms. Currently ALDH activity is evidenced by using Aldefluor, a fluorescent substrate likely to be metabolized by numerous ALDH isoforms. Therefore, isolation techniques based on ALDH activity detection select a heterogeneous population of stem or progenitor cells. Despite active research in the field, the precise role(s) of different ALDH isoforms in stem cells remains enigmatic. Understanding the metabolic role of different ALDH isoform in the control of stem cell phenotype and cell fate during development, tissue homeostasis, or repair, as well as carcinogenesis, should open perspectives to significant discoveries in tissue biology. In this perspective, novel ALDH substrates are being developed. Here we describe how new substrates could be instrumental for better isolation of cell population with stemness potential and for defining hierarchy of cell populations in tissue. Finally, we speculate on other potential applications
- …