Density Matrix Renormalization Group for Dummies

We describe the Density Matrix Renormalization Group algorithms for time dependent and time independent Hamiltonians. This paper is a brief but comprehensive introduction to the subject for anyone willing to enter in the field or write the program source code from scratch.Comment: 29 pages, 9 figures. Published version. An open source version of the code can be found at http://qti.sns.it/dmrg/phome.htm

Il coinvolgimento drammaturgico e sensoriale dello spettatore negli spettacoli del Teatro del Lemming

Teatro del Lemming Company works since almost thirty years around the dramaturgical and sensorial involvement of the spectator. The first sensorial dramaturgy of Teatro del Lemming is Oedipus. Tragedy of senses for one spectator. The spectacle had its première in 1997. This piece breaks the mirror of the representation: the spectator sinks inside the dramaturgy with all his five senses. The spectator is blindfolded and has the protagonist’s role. He is led to re-experience on his body all landmarks of Oedipus’ myth. Certainly the condition of being blind creates a greater openness of the other senses. After Oedipus, the sensorial and dramaturgical involvement of the audience has become the particular sign of Teatro del Lemming’s theatrical productions

From perfect to fractal transmission in spin chains

Perfect state transfer is possible in modulated spin chains, imperfections however are likely to corrupt the state transfer. We study the robustness of this quantum communication protocol in the presence of disorder both in the exchange couplings between the spins and in the local magnetic field. The degradation of the fidelity can be suitably expressed, as a function of the level of imperfection and the length of the chain, in a scaling form. In addition the time signal of fidelity becomes fractal. We further characterize the state transfer by analyzing the spectral properties of the Hamiltonian of the spin chain.Comment: 8 pages, 10 figures, published versio

From Indication-Based Pricing to Blended Approach: Evidence on the Price and Reimbursement Negotiation in Italy

BackgroundNew indications for existing medicines are increasing over time. In most countries, drug pricing and reimbursement conditions are renegotiated every time a new indication is approved. There is a growing interest in the price negotiation model for new indications, specifically comparing an indication-based versus blended approach. However, little evidence currently exists regarding the complexity of these negotiations and their impact on actual prices. Italy has recently transitioned from an indication-based approach to a blended price model. This study aims to measure the impact of price and reimbursement negotiation of new indications on discounts (i.e. actual prices) and on the negotiation duration, used as a proxy of its complexity.MethodsWe considered new indications approved through a European centralized procedure from January 2013 to March 2022 for which the price and reimbursement status was approved in Italy between January 2015 and March 2022, amounting to 52 new indications. Data on the timeframe of the Italian price and reimbursement process and its phases were obtained from publicly available sources. Discounts for the first indication and their subsequent increases for new indications were estimated by comparing ex-factory prices and tendered prices. To calculate p-values, we employed the Mann-Whitney test, and multiple regression models were utilized to examine correlations between negotiation time and the characteristics of the medicines.ResultsThe mean time to reimbursement was 603 days, in contrast to 583 days for the first launch. Price negotiation took longer for rare diseases, cancer drugs, and in case of therapies with minor added therapeutic value. On average, the additional discount (on top of discounts for prior indications) was 13%, significantly lower than the mean discount for the first indications approved (24.9%). The discounts increment was lower, but negotiation took longer if a Managed Entry Agreement accompanied the final agreement. Additionally, discounts have increased over the years.ConclusionThe negotiation for new indications takes longer than the first one, and provides, on average, an additional discount of 13%. While our findings bear the potential for significant policy implications, they necessitate prudent interpretation due to a limited number of observations. The increasing trend in additional discounts over time applied to all indications in recent negotiations, may suggest a descending trend of value for new indications and a shift from an indication-based pricing approach to a blended model. Otherwise, budget impact considerations might have outweighed a value-based approach in the recent negotiations. If so, two potential options for restoring a value-based approach are returning to an indication-based pricing or giving explicit and higher weight to value within a blended model

Radioguided Parathyroidectomy with Portable Mini Gamma-Camera for the Treatment of Primary Hyperparathyroidism

Background. A proper localisation of pathological parathyroid glands is essential for a minimally invasive approach in the surgical treatment of primary hyperparathyroidism (PHP). The recent introduction of portable mini gamma-cameras (pMGCs) enabled intraoperative scintigraphic scanning. The aim of our study is to evaluate the efficacy of this new method and compare it with the preoperative localisation surveys. Methods. 20 patients were studied; they were evaluated preoperatively by neck ultrasound and Tc-sestaMIBI-scintigraphy and intraoperatively with the pMGC IP Guardian 2. The results obtained from the three evaluations were compared. Results. The pMGC presented a sensitivity of 95%, a specificity of 98.89%, and a diagnostic accuracy of 98.18%, which were higher than those of preoperative ultrasound (sensitivity 55%; specificity 95%; diagnostic accuracy 87%) and scintigraphy with Tc-sestaMIBI (sensitivity 73.68%; specificity 96.05%; diagnostic accuracy 91.58%). Conclusions. The pMGC can be used effectively as an intraoperative method to find the correct location of the pathological parathyroid glands. The pMGC is more reliable than the currently used preoperative and intraoperative localisation techniques

Mapping of Asbestos Cement Roofs and Their Weathering Status Using Hyperspectral Aerial Images

and (ii) the development of a spectral index related to the roof weathering status. Aerial images were collected through the Multispectral Infrared and Visible Imaging Spectrometer (MIVIS) sensor, which acquires data in 102 channels from the visible to the thermal infrared spectral range. An image based supervised classification was performed using the Spectral Angle Mapper (SAM) algorithm. The SAM was trained through a set of pixels selected on roofs of different materials. The map showed an average producer's accuracy (PA) of 86% and a user's accuracy (UA) of 89% for the asbestos cement class. A novel spectral index, the "Index of Surface Deterioration" (ISD), was defined based on measurements collected with a portable spectroradiometer on asbestos cement roofs that were characterized by different weathering statuses. The ISD was then calculated on the MIVIS images, allowing the distinction of two weathering classes (i.e., high and low). The asbestos cement map was handled in a Geographic Information System (GIS) in order to supply the municipalities with the cadastral references of each property having an asbestos cement roof. This tool can be purposed for municipalities as an aid to prioritize asbestos removal, based on roof weathering status

Solid biofuels production from agricultural residues and processing by-products by means of torrefaction treatment: the case of sunflower chain

The high heterogeneity of some residual biomasses makes rather difficult their energy use. Their standardisation is going to be a key aspect to get good quality biofuels from those residues. Torrefaction is an interesting process to improve the physical and chemical properties of lignocellulosic biomasses and to achieve standardisation. In the present study torrefaction has been employed on residues and by-products deriving from sunflower production chain, in particular sunflower stalks, husks and oil press cake. The thermal behaviour of these materials has been studied at first by thermogravimetric analysis in order to identify torrefaction temperatures range. Afterwards, different residence time and torrefaction temperatures have been tested in a bench top torrefaction reactor. Analyses of raw and torrefied materials have been carried out to assess the influence of the treatment. As a consequence of torrefaction, the carbon and ash contents increase while the volatilisation range reduces making the material more stable and standardised. Mass yield, energy yield and energy densification reach values of about 60%, 80% and 1.33 for sunflower stalks and 64%, 85% and 1.33 for sunflower oil press cake respectively. As highlighted by the results, torrefaction is more interesting for sunflower stalks than oil cake and husks due to their different original characteristics. Untreated oil press cake and husks, in fact, already show a good high heating value and, for this reason, their torrefaction should be mild to avoid an excessive ash concentration. On the contrary, for sunflower stalks the treatment is more useful and could be more severe

Efficient and perfect state transfer in quantum chains

We present a communication protocol for chains of permanently coupled qubits which achieves perfect quantum state transfer and which is efficient with respect to the number chains employed in the scheme. The system consists of $M$ uncoupled identical quantum chains. Local control (gates, measurements) is only allowed at the sending/receiving end of the chains. Under a quite general hypothesis on the interaction Hamiltonian of the qubits a theorem is proved which shows that the receiver is able to asymptotically recover the messages by repetitive monitoring of his qubits.Comment: 6 pages, 2 figures; new material adde

Nitrogen status assessment for variable rate fertilization in maize through hyperspectral imagery

This paper presents a method for mapping the nitrogen (N) status in a maize field using hyperspectral remote sensing imagery. An airborne survey was conducted with an AISA Eagle hyperspectral sensor over an experimental farm where maize (Zea mays L.) was grown with two N fertilization levels (0 and 100 kg N ha-1) in four replicates. Leaf and canopy field data were collected during the flight. The nitrogen (N) status has been estimated in this work based on the Nitrogen Nutrition Index (NNI) defined as the ratio between the leaf actual N concentration (%Na) of the crop and the minimum N content required for the maximum biomass production (critical N concentration (%Nc)) calculated through the dry mass at the time of the flight (Wflight). The inputs required to calculate the NNI (i.e. %Na and Wflight) have been estimated through regression analyses between field data and remotely sensed vegetation indices. MCARI/MTVI2 (Modified Chlorophyll Absorption Ratio Index / Modified Triangular Vegetation Index 2) showed the best performances in estimating the %Na (R2 = 0.59) and MTVI2 in estimating the Wflight (R2 = 0.80). The %Na and the Wflight were then mapped and used to compute the NNI map over the entire field. The NNI map agreed with the NNI estimated using field data through traditional destructive measurements (R2 = 0.70) confirming the potential of using remotely sensed indices to assess the crop N condition. Finally, a method to derive a pixel based variable rate N fertilization map was proposed as the difference between the actual N content and the optimal N content. We think that the proposed operational methodology is promising for precision farming since it represents an innovative attempt to derive from an aerial hyperspectral image a variable rate N fertilization map based on the actual crop N status.JRC.H.4-Monitoring Agricultural Resource