Impurities in a one-dimensional Bose gas: the flow equation approach

A few years ago, flow equations were introduced as a technique for calculating the ground-state energies of cold Bose gases with and without impurities. In this paper, we extend this approach to compute observables other than the energy. As an example, we calculate the densities, and phase fluctuations of one-dimensional Bose gases with one and two impurities. For a single mobile impurity, we use flow equations to validate the mean-field results obtained upon the Lee-Low-Pines transformation. We show that the mean-field approximation is accurate for all values of the boson-impurity interaction strength as long as the phase coherence length is much larger than the healing length of the condensate. For two static impurities, we calculate impurity-impurity interactions induced by the Bose gas. We find that leading order perturbation theory fails when boson-impurity interactions are stronger than boson-boson interactions. The mean-field approximation reproduces the flow equation results for all values of the boson-impurity interaction strength as long as boson-boson interactions are weak.Comment: Re-submission to SciPost. Major changes are highlighte

A call to action by the italian mesotherapy society on scientific research

: Mesotherapy (local intradermal therapy, LIT) is a technique used to slowly spread drugs in tissues underlying the site of injection to prolong the pharmacological effect with respect to intramuscular injection. Recommendations for proper medical use of this technique have been made for pain medicine and rehabilitation, chronic venous disease, sport medicine, musculoskeletal disorders, several dermatological conditions, skin ageing, and immune-prophylaxis. Although mesotherapy is considered a valid technique, unresolved questions remain, which should be answered to standardize methodology and dosing regimen as well as to define the right indications in clinical practice. New randomized controlled trials are needed to test single products (dose, frequency of administration, efficacy and safety). Even infiltration of substances for dermo-cosmetic purposes must be guided by safety and efficacy tests before being proposed by mesotherapy. In this article, we put forth a preclinical and clinical research plan and a health technology assessment as a call to action by doctors, researchers and scientific societies to aid national health authorities in considering mesotherapy for prevention, treatment and rehabilitation paths

Mesotherapy: From Historical Notes to Scientific Evidence and Future Prospects

Intradermal therapy, known as mesotherapy, is a technique used to inject a drug into the surface layer of the skin. In particular, it involves the use of a short needle to deposit the drug in the dermis. The intradermal microdeposit modulates the drug's kinetics, slowing absorption and prolonging the local mechanism of action. It is successfully applied in the treatment of some forms of localized pain syndromes and other local clinical conditions. It could be suggested when a systemic drug-sparing effect is useful, when other therapies have failed (or cannot be used), and when it can synergize with other pharmacological or nonpharmacological therapies. Despite the lack of randomized clinical trials in some fields of application, a general consensus is also reached in nonpharmacological mechanism of action, the technique execution modalities, the scientific rationale to apply it in some indications, and the usefulness of the informed consent. The Italian Mesotherapy Society proposes this position paper to apply intradermal therapy based on scientific evidence and no longer on personal bias

Forecasting Cryptocurrency Value by Sentiment Analysis: An HPC-Oriented Survey of the State-of-the-Art in the Cloud Era

This chapter surveys the state-of-the-art in forecasting cryptocurrency value by Sentiment Analysis. Key compounding perspectives of current challenges are addressed, including blockchains, data collection, annotation, and filtering, and sentiment analysis metrics using data streams and cloud platforms. We have explored the domain based on this problem-solving metric perspective, i.e., as technical analysis, forecasting, and estimation using a standardized ledger-based technology. The envisioned tools based on forecasting are then suggested, i.e., ranking Initial Coin Offering (ICO) values for incoming cryptocurrencies, trading strategies employing the new Sentiment Analysis metrics, and risk aversion in cryptocurrencies trading through a multi-objective portfolio selection. Our perspective is rationalized on the perspective on elastic demand of computational resources for cloud infrastructures

Technical trading and cryptocurrencies

This paper carries out a comprehensive examination of technical trading rules in cryptocurrency markets, using data from two Bitcoin markets and three other popular cryptocurrencies. We employ almost 15,000 technical trading rules from the main five classes of technical trading rules and find significant predictability and profitability for each class of technical trading rule in each cryptocurrency. We find that the breakeven transaction costs are substantially higher than those typically found in cryptocurrency markets. To safeguard against data-snooping, we implement a number of multiple hypothesis procedures which confirms our findings that technical trading rules do offer significant predictive power and profitability to investors. We also show that the technical trading rules offer substantially higher risk-adjusted returns than the simple buy-and-hold strategy, showing protection against lengthy and severe drawdowns associated with cryptocurrency markets. However there is no predictability for Bitcoin in the out-of-sample period, although predictability remains in other cryptocurrency markets

Recovering critique in an age of datafication

This article starts out from the need for critical work on processes of datafication and their consequences for the constitution of social knowledge and the social world. Current social science work on datafication has been greatly shaped by the theoretical approach of Bruno Latour, as reflected in the work of Actor Network Theory and Science and Technology Studies (ANT/STS). The article asks whether this approach, given its philosophical underpinnings, provides sufficient resources for the critical work that is required in relation to datafication. Drawing on Latour’s own reflections about the flatness of the social, it concludes that it does not, since key questions, in particular about the nature of social order cannot be asked or answered within ANT. In the article’s final section, three approaches from earlier social theory are considered as possible supplements to ANT/STS for a social science serious about addressing the challenges that datafication poses for society

Anschauliches Erzählen – mit und ohne fiktiven Erzähler:Mit einer Modellanalyse von Christian Krachts Roman »Die Toten« (2016)

In diesem Beitrag geht Adrian Brauneis der Frage nach, wie sich sinnliche Unmittelbarkeit in fiktionalen Texten manifestieren lässt und ferner, welche Rolle eine entsprechende Erzählerinstanz hierbei zukommt. Es wird zunächst untersucht und dargelegt, was die literarästhetischen Verfahren sind, die einem literarischen Text zur Anschaulichkeit und Anschaulichkeitssteigerung verhelfen. Die theoretischen Ansätze und Befunde zu dezidiert anschaulichen Erzählweisen werden dabei mittels einer Modellanalyse von Christian Krachts Roman Die Toten untermauert