Causal structure of the entanglement renormalization ansatz

We show that the multiscale entanglement renormalization ansatz (MERA) can be reformulated in terms of a causality constraint on discrete quantum dynamics. This causal structure is that of de Sitter space with a flat spacelike boundary, where the volume of a spacetime region corresponds to the number of variational parameters it contains. This result clarifies the nature of the ansatz, and suggests a generalization to quantum field theory. It also constitutes an independent justification of the connection between MERA and hyperbolic geometry which was proposed as a concrete implementation of the AdS-CFT correspondence

New perspectives for the design of sustainable bioprocesses for phosphorus recovery from waste

Phosphate rock has long been used for the production of phosphorus based chemicals. However, considering the depletion of the reservoirs and the decrease of the quality of phosphate rocks, a potential market is now emerging for the recovery of phosphate from waste and its reuse for different applications. Notably, phosphate recovery from wastewater could be included in a circular economy approach. This review focuses on the use of microbial systems for phosphorus accumulation and recovery, by considering the actual range of analytical techniques available for the monitoring of phosphorus accumulating organisms, as well as the actual biochemical and metabolic engineering toolbox available for the optimization of bioprocesses. In this context, knowledge gathered from process, system and synthetic biology could potentially lead to innovative process design

First report of emicizumab use in a female patient with severe hemophilia A.

KEY POINTS : This is the first report of successful use of emicizumab in a female patient with severe hemophilia A

Low rate of subclinical venous thrombosis in patients with haemophilia undergoing major orthopaedic surgery in the absence of pharmacological thromboprophylaxis.

BACKGROUND: Deep venous thrombosis (DVT) is a common postoperative complication in patients undergoing major orthopaedic surgery of the lower limbs, such as total hip or knee replacement (THR, TKR). Routine pharmacological thromboprophylaxis with low-molecular-weight heparin (LMWH) or a direct oral anticoagulant agent is strongly recommended in this setting. THR and TKR as well as ankle arthrodesis are frequently performed in people with haemophilia (PWH) and chronic haemophilic arthropathy. Pharmacological thromboprophylaxis in this population remains controversial. METHODS: We report the results of a single-centre prospective study initiated in 2002 evaluating by systematic Doppler ultrasound the incidence of subclinical DVT in consecutive PWH referred for major orthopaedic surgery and not receiving pharmacological thromboprophylaxis. RESULTS: We included 46 different PWH (39 Haemophilia A, 7 Haemophilia B, 27 severe, 15 moderate and 4 mild forms) undergoing 67 orthopaedic procedures. Most (89.5%) were performed with continuous infusion of clotting factor concentrates. Rehabilitation was usually started on day 1 post-op. No clinical DVT or pulmonary embolism was suspected. In total, there were 5 cases (3 severe, 1 moderate HA and 1 moderate HB) of subclinical DVT which were all distal. Two patients were treated with a short course (10-14 days) of LMWH. The overall incidence of DVT was 7.5%. CONCLUSIONS: These data provide imaging-based evidence that the risk of DVT following major orthopaedic surgery among PWH is low. Identified DVTs were distal and resolved spontaneously in most cases. Systematic pharmacological thromboprophylaxis in this specific population is probably for most patients not required

Individual social capital of entrepreneurs: a multidimensional measurement approach

Social network embeddedness lowers the transaction costs for firms’ entrepreneurs and enables them to obtain access to information and resources at a price below market-costs. We argue that the access to and use of this entrepreneurial social capital entails a complex interplay of structural, relational and mobilization dimensions both at the local and extended level. By grouping types of entrepreneurs based on these multiple dimensions we show the unequal distribution of social capital across entrepreneurial populations and identify distinct social capital configurations to affect specific entrepreneurial outcomes

Radiation transfer model intercomparison (RAMI) exercise

International audienceThe community involved in modeling radiation transfer over terrestrial surfaces designed and implemented the first phase of a radiation transfer model intercomparison (RAMI) exercise. This paper discusses the rationale and motivation for this endeavor, presents the intercomparison protocol as well as the evaluation procedures, and describes the principal results. Participants were asked to simulate the transfer of radiation for a variety of precisely defined terrestrial environments and illumination conditions. These were abstractions of typical terrestrial systems and included both homogeneous and heterogeneous scenes. The differences between the results generated by eight different models, including both one-dimensional and three-dimensional approaches, were then documented and analyzed. RAMI proposed a protocol to quantitatively assess the consequences of the model discrepancies with respect to application, such as those motivating the development of physically based inversion procedures. This first phase of model intercomparison has already proved useful in assessing the ability of the modeling community to generate similar radiation fields despite the large panoply of models that were tested. A detailed analysis of the results also permitted to identify apparent“outliers” and their main deficiencies. Future undertakings in this intercomparison framework must be oriented toward an expansion of RAMI into other and more complex geophysical systems as well as the focusing on actual inverse problems

Radiation transfer model intercomparison (RAMI) exercise

International audienceThe community involved in modeling radiation transfer over terrestrial surfaces designed and implemented the first phase of a radiation transfer model intercomparison (RAMI) exercise. This paper discusses the rationale and motivation for this endeavor, presents the intercomparison protocol as well as the evaluation procedures, and describes the principal results. Participants were asked to simulate the transfer of radiation for a variety of precisely defined terrestrial environments and illumination conditions. These were abstractions of typical terrestrial systems and included both homogeneous and heterogeneous scenes. The differences between the results generated by eight different models, including both one-dimensional and three-dimensional approaches, were then documented and analyzed. RAMI proposed a protocol to quantitatively assess the consequences of the model discrepancies with respect to application, such as those motivating the development of physically based inversion procedures. This first phase of model intercomparison has already proved useful in assessing the ability of the modeling community to generate similar radiation fields despite the large panoply of models that were tested. A detailed analysis of the results also permitted to identify apparent“outliers” and their main deficiencies. Future undertakings in this intercomparison framework must be oriented toward an expansion of RAMI into other and more complex geophysical systems as well as the focusing on actual inverse problems