Multipartite entanglement detection for hypergraph states

We study the entanglement properties of quantum hypergraph states of $n$ qubits, focusing on multipartite entanglement. We compute multipartite entanglement for hypergraph states with a single hyperedge of maximum cardinality, for hypergraph states endowed with all possible hyperedges of cardinality equal to $n-1$ and for those hypergraph states with all possible hyperedges of cardinality greater than or equal to $n-1$. We then find a lower bound to the multipartite entanglement of a generic quantum hypergraph state. We finally apply the multipartite entanglement results to the construction of entanglement witness operators, able to detect genuine multipartite entanglement in the neighbourhood of a given hypergraph state. We first build entanglement witnesses of the projective type, then propose a class of witnesses based on the stabilizer formalism, hence called stabilizer witnesses, able to reduce the experimental effort from an exponential to a linear growth in the number of local measurement settings with the number of qubits

Sulla strada della demolizione e ricostruzione: il quartiere di Sant’Ermete a Pisa

Recenti contributi della letteratura urbanistico-architettonica evidenziano la scarsa qualità progettuale degli spazi urbani contemporanei e la conseguente necessità di promuovere una rinnovata cultura del disegno urbano. Tale ricerca dovrebbe orientarsi su sentieri esplorativi volti alla codifica di nuovi linguaggi compositivi, espressioni di una dimensione ‘estetica’ contemporanea, esito di un complesso sistema relazionale in divenire tra le varie componenti insediative strutturali (economiche, socio-culturali ed ecologiche), produttrice di luoghi urbani di qualità. A tal fine vengono anche promosse nuove pratiche di trasformazione urbana basate su radicali operazioni di demolizione con ricostruzione di alcune parti di città particolarmente critiche. Il tema della demolizione e ricostruzione di alcuni brani di città non è, tuttavia, privo di elementi di problematicità, tra cui le difficoltà connesse alla delocalizzazione della comunità locale, gli elevati costi economici e impegni di tempo necessari, la dubbia qualità dei disegni urbani che si vanno a sostituire ai vecchi tessuti. L’esperienza qui presentata, riguardante una complessa operazione, attualmente in corso, di demolizione con ricostruzione di un’area di edilizia economica e popolare situata nel quartiere di Sant’Ermete a Pisa, rappresenta un compendio esemplare degli elementi di forza e di debolezza presenti in questo tipo di operazioni.Recent studies in urban and architectural literature highlight the low design quality of contemporary urban spaces and the resulting need to promote a new culture of urban design. Such a research should follow exploration paths pointed at codifying new compositional languages, expressions of a contemporary ‘aesthetic’ dimension as outcome of the complex and changing spatial relations among the various structural components of settlement (economic, socio-cultural and ecological), and able to produce quality urban spaces. To this end, new urban transformation practices are also being promoted, based on extreme demolition and reconstruction processes of city areas with remarkable problems. The topic of demolition and reconstruction of city parts, however, is not lacking critical elements: among them, the dislocation of local communities, the high economic and time costs, the uncertain quality of the new urban designs replacing the old fabrics. The experience here presented, regarding a complex operation, presently underway, of demolition and reconstruction of a council housing area in the urban district of Sant’Ermete, Pisa, represents a model summary of the strength and weakness elements of this kind of operations

Candida freyschussii: an oleaginous yeast producing lipids from glycerol

A surplus of glycerol is obtained from biodiesel manufacturing and represents a waste product whose applications are lacking. Thus, the use of glycerol as substrate for fermentation processes yielding valuable products is very attractive. In this study, the utilization of glycerol as a growth substrate for the cultivation of oleaginous yeasts was explored with the aim to produce microbial oils. Forty strains of environmental non-conventional yeasts belonging to 19 different species were screened for the ability to grow on glycerol and produce intracellular lipids in a medium containing an excess of this carbon source (C:N = 48:1). Three strains, belonging to the species Candida freyschussii, Pichia farinosa, and Saccharomyces spencerorum, depleted 40 g/L glycerol within 120 h and produced intracellular lipids. C. freyschussii yielded the highest amounts, lipids accounting for the 33 % of biomass on dry basis. 1H-NMR analysis revealed that the lipid extract did not contain detectable free fatty acids and was composed mostly of triacylglycerols. Lipid composition, determined by GC-MS analysis, was similar to plant oils, and may be optimal feedstock for biodiesel production, being dominated by monounsaturated C16 and C18. As in other oleaginous yeasts, lipid production by C. freyschussii sp. increased with the increase of the C:N ratio of the medium, but growth was inhibited at glycerol concentrations higher than 40 g/L. As a result, lipid production was the highest with 40 g/L glycerol, yielding 4.7 g/L lipids, with a mean volumetric productivity of 0.15 g/L/h. In order to prevent growth inhibition over 40 g/L glycerol and extend the lipogenic phase, different fed-batch strategies were tried. The best performing processes took advantage from the feeding with concentrated media exhibiting the same C:N ratio of the basal medium, leading to very productive high cell density cultures. With the continuous feeding of 20X-concentrated medium, 29 g/L lipids (i.e. the 32 % of biomass) were obtained in 100 h of cultivation, with a mean volumetric productivity of 0.30 g/L/h. The values herein reported are among the highest yield and productivity values ever obtained for fermentative processes exploiting oleaginous fungi to produce lipids from glycerol. Therefore, C. freyschussii could be considered as an interesting microorganism to convert glycerol into microbial oils for biofuel industr

Getting Lipids for Biodiesel Production from Oleaginous Fungi

Biomass-based biofuel production represents a pivotal approach to face high energy prices and potential depletion of crude oils reservoirs, to reduce greenhouse gas emissions, and to enhance a sustainable economy (Zinoviev et al., 2010). Microbial lipids can represent a valuable alternative feedstock for biodiesel production, and a potential solution for a bio-based economy.Nowadays, the production of biodiesel is based mostly on plant oils, even though animal fats, and algal oils can also be used. In particular, soybean, rapeseed, and palm oils are adopted as the major feedstock for biodiesel production. They are produced on agricultural land, opening the debate on the impact of the expansion of bioenergy crop cultures, which displace land from food production. Furthermore, their price restricts the large-scale development of biodiesel to some extent. In order to meet the increasing demand of biodiesel production, other oil sources have been explored. Recently, the development of processes to produce single cell oil (SCO) by using heterotrophic oleaginous microorganisms has triggered significant attention (Azocar et al., 2010). These organisms accumulate lipids, mostly consisting of triacylglycerols (TAG), that form the storage fraction of the cell. The occurrence of TAG as reserve compounds is widespread among all eukaryotic organisms such as fungi, plants and animals, whereas it has only rarely been described in bacteria (Meng et al., 2009). In fact, bacteria generally accumulate polyhydroxyalkanoates as storage compound and only few bacterial species, belonging to the actinobacterial genera Mycobacterium, Streptomyces, Rhodococcus and Nocardia produce relevant amounts of lipids (Alvarez & Steinbuchel, 2002).Among heterotrophic microorgansisms, oleaginous fungi, including both molds and yeasts, are increasingly been reported as good TAG producers. This chapter will focus on current knowledge advances in their metabolism, physiology, and in the result achieved in strain improvement, process engineering and raw material exploitation

Acute respiratory distress syndrome in an uromastyx (uromastyx acanthinura nigriventris, 1820)

This article describes a case of acute respiratory distress syndrome (ARDS) in a 3-year-old Uromastyx acanthinura gravinensis. The lizard was presented to the veterinary hospital with an 8-day history of respiratory distress. After the initial physical examination, the patient was treated for the respiratory condition for three weeks and subsequently discharged. The bearded dragon died two weeks following release from the veterinary hospital, after an episode of acute dyspnea. Acute respiratory syndrome was diagnosed following histological examination of submitted tissue samples. The authors believe the condition was caused by possible environmental exposure to volatile organic compounds