88 research outputs found
U(N|M) quantum mechanics on Kaehler manifolds
No full textWe study the extended supersymmetric quantum mechanics, with supercharges transforming in the fundamental representation of U(N|M), as realized in certain one-dimensional nonlinear sigma models with Kaehler manifolds as target space. We discuss the symmetry algebra characterizing these models and, using operatorial methods, compute the heat kernel in the limit of short propagation time. These models are relevant for studying the quantum properties of a certain class of higher spin field equations in first quantization
Mode regularization for N = 1, 2 SUSY Sigma model
No full textWorldline N = 1 and N = 2 supersymmetric sigma models in curved background are useful to describe spin one-half and spin one particles coupled to external gravity, respectively. It is well known that worldline path integrals in curved space require regularization: we present here the mode-regularization for these models, finding in particular the corresponding counterterms, both in the case of flat and curved indices for worldline fermions. For N = 1, using curved indices we find a contribution to the counterterm from the fermions that cancels the contribution of the bosons, leading to a vanishing total counterterm and thus preserving the covariance and supersymmetry of the classical action. Conversely in the case of N = 2 supersymmetries we obtain a non-covariant counterterm with both curved and flat indices. This work completes the analysis of the known regularization schemes for N = 1, 2 nonlinear sigma models in one dimension. © 2008 SISSA
Pain management in total knee arthroplasty
No full textPain control is an essential aspect of surgery. Deep knowledge of pain pathophysiology is essential to improve the result of surgery. This paper analyses some of the mechanisms that lead to pain and proposes for each of them a treatment based on specific patterns
Stuck in the Middle: the Psychophysics of Goal Pursuit
No full textThe classic goal-gradient hypothesis posits that motivation increases monotonically with proximity to a goal. However, we show that
motivation is higher when either far or close to a goal, and decreases halfway to a goal. The psychophysics of goal pursuit accounts
for this tendency to get “stuck in the middle.
On Braggarts and Gossips: A Self-Enhancement Account of Word-of-Mouth Generation and Transmission
No full textPast research on word-of-mouth has presented inconsistent evidence as to whether consumers are more inclined to share positive or negative information about products and services. Some findings suggest that consumers are more inclined to engage in positive word-of-mouth, whereas others suggest that consumers are more inclined to engage in negative word-of-mouth. The present research offers a theoretical perspective that provides one means to resolve these seemingly contradictory findings. Specifically, the present work compares the generation of word-of-mouth (i.e., consumers sharing information about their own experiences) to the transmission of word-mouth (i.e., consumers passing-on information about experiences they heard occurred to others). The authors suggest that a basic human motive to self-enhance leads consumers to generate positive word-of-mouth (i.e., share information about their own positive consumption experiences), but transmit negative word-of-mouth (i.e., pass-on information they heard about other’s negative consumption experiences). The authors present evidence for self-enhancement motives playing out in opposite ways at word-of-mouth generation compared to word-of-mouth transmission across four experiments
The pharmacological treatment of neuropathic pain
No full textNeuropathic Pain (NP) as reported by IASP (International Association Study of Pain) is a "Pain arising as a direct consequence of a lesion or disease affecting the somatosensory system". In clinical practice NP is divided in peripheral and central pain and it is characterised by positive and negative symptoms. It is not so easy to plan out an effective therapy for this kind of pain. In this article we try to suggest a method to adapt drugs according to pain mechanisms and somatosensory pathways damages. In this "mechanisms based therapy", drugs and invasive procedures are used according to a complete examination (bedside and instrumental) of the patient's signs and symptoms. We describe characteristics of NP symptoms in order to individualise our therapeutic target and then we list the possible therapeutic drugs for these kinds of symptom
Compensatory Word of Mouth: Advice as a Device to Restore Control
No full textConsumers often give advice by recommending products and services to one another. The
present research explores the idea that advice giving sometimes reflects a self-serving desire to
compensate for a loss of control. Four experiments provide convergent evidence for a
phenomenon we term compensatory word of mouth, whereby consumers’ communications
contain advice fueled by their own need to restore control. Experiment 1 explores the potential
practical relevance of this idea by showing that advertising messages can threaten consumers’
sense of control and increase advice giving in word-of-mouth communications. Experiment 2
uses a different paradigm and further demonstrates that a threat to consumers’ sense of control
increases advice giving. As additional evidence of a compensatory account, Experiment 3 finds
that threatened individuals’ propensity to give advice is attenuated when they are first given an
alternative means to restore a sense of control. Finally, Experiment 4 demonstrates that advice
giving can serve a compensatory function by instilling a greater sense of competence that
enhances consumers’ feelings of control
Vertebral body innervation: Implications for pain
No full textVertebral fractures often cause intractable pain. To define the involvement of vertebral body innervation in pain, we collected specimens from male and female patients during percutaneous kyphoplasty, a procedure used for reconstruction of the vertebral body. Specimens were taken from 31 patients (9 men and 22 women) suffering high-intensity pain before surgery. In total, 1,876 histological preparations were obtained and analysed. Immunohistochemical techniques were used to locate the nerves in the specimens. The nerve fibres were labelled by indirect immunofluorescence with the primary antibody directed against Protein Gene Product 9.5 (PGP 9.5), a pan-neuronal marker; another primary antibody directed against type IV collagen (Col IV) was used to identify vessels and to determine their relationship with vertebral nerve fibres. The mean percentage of samples in which it was possible to identify nerve fibres was 35% in men and 29% in women. The percentages varied depending on the spinal level considered and the sex of the subject, nerve fibres being mostly present around vessels (95%). In conclusion, there is scarce innervation of the vertebral bodies, with a clear prevalence of fibres located around vessels. It seems unlikely that this pattern of vertebral body innervation is involved in vertebral pain or in pain relief following kyphoplasty
On Braggarts and Gossips: Why Consumers Generate Positive but Transmit Negative Word-of-Mouth
No full textPast research has presented conflicting evidence as to whether consumers are more likely to share positive or negative word-of-mouth. We offer a novel theoretical perspective to reconcile this conflict by comparing the generation of word-of-mouth (i.e., consumers sharing information about their own experiences) to the transmission of word-of-mouth (i.e., consumers passing-on information about experiences they heard occurred to others). We suggest that the self-enhancement motive leads consumers to generate positive word-of-mouth, but also to transmit negative word-of-mouth. Evidence for self-enhancement motives playing out in a unique fashion at word-of-mouth generation and transmission is presented across a series of four experiments
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