The utilization of the response surface methodology for the optimization of cultivation medium and growth parameters in the cultivation of the yeast strain S. cerevisiae 3.20 on ethanol

A mutant strain of the yeast Saccharomyces cerevisiae growing on ethanol as single source of carbon and energy was used in optimization experiments at laboratory and micropilot scale, following the surface response methodology. The cultivation medium optimization was performed on the basis of maximization of dry cell weight and the process parameters optimization on the basis of substrate yield maximization

Heterocyst placement strategies to maximize growth of cyanobacterial filaments

Under conditions of limited fixed-nitrogen, some filamentous cyanobacteria develop a regular pattern of heterocyst cells that fix nitrogen for the remaining vegetative cells. We examine three different heterocyst placement strategies by quantitatively modelling filament growth while varying both external fixed-nitrogen and leakage from the filament. We find that there is an optimum heterocyst frequency which maximizes the growth rate of the filament; the optimum frequency decreases as the external fixed-nitrogen concentration increases but increases as the leakage increases. In the presence of leakage, filaments implementing a local heterocyst placement strategy grow significantly faster than filaments implementing random heterocyst placement strategies. With no extracellular fixed-nitrogen, consistent with recent experimental studies of Anabaena sp. PCC 7120, the modelled heterocyst spacing distribution using our local heterocyst placement strategy is qualitatively similar to experimentally observed patterns. As external fixed-nitrogen is increased, the spacing distribution for our local placement strategy retains the same shape while the average spacing between heterocysts continuously increases.Comment: This is an author-created, un-copyedited version of an article accepted for publication in Physical Biology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher-authenticated version will be available onlin

A Processual Approach To Friction in Quadruple Helix Collaborations

R&D collaborations between industry, government, civil society, and research (also known as ‘quadruple helix collaborations’ (QHCs)) have recently gained attention from R&D theorists and practitioners. In aiming to come to grips with their complexity, past models have generally taken a stakeholder-analytical approach based on stakeholder types. Yet stakeholder types are difficult to operationalise. We therefore argue that a processual model is more suited for studying the interaction in QHCs because it eschews matters of titles and identities. We develop such a model in which the QHC is represented as a process of generating four types of value: research value, market value, political value, and societal value. We then apply this processual model in analysing real-life cases of friction in QHCs. Friction is seen, not as an interpersonal clash, but as a discrepancy between two or more value-creation processes that compete for limited resources (some over-performing while others under-performing)

thermodynamic properties of pb3u11o36

Abstract In order to progress in the development of Lead-cooled Fast Reactors, from the safety point of view it is essential to understand the chemical compatibility between liquid lead and uranium oxide. In the present work, entropy and heat capacity of Pb3U11O36, a possible ternary compound coming from fuel-coolant chemical interaction, were determined for the first time. Entropy at 298.15 K was obtained from low temperature heat capacity measurements using the Physical Property Measurement System (PPMS) in the temperature range 2–300 K, while the high temperature heat capacity has been measured by a drop calorimeter from 373 K to 1200 K. The experimental thermodynamic properties were compared with the values computed by means of DFT-GGA simulations, obtaining a very good agreement

Synthesis and characterization of nanocrystalline U1−x_{1-x}Pux_{x}O2(+y)_{2(+y)} mixed oxides

We report here the first synthesis of mixed oxide U$_{1-x}$Pu$_{x}$O$_{2(+y)}$ nanoparticles. The obtained nanopowders were characterized by X-ray diffraction, thermal ionization mass spectrometry, transmission electron microscopy, Raman spectroscopy, and U M$_{4}$ edge high-energy-resolution X-ray absorption near edge structure (HR-XANES). The HR-XANES spectra give evidence for the partial oxidation of U$^{IV}$ to U$^{V}$. This novel route toward the formation of actinide–actinide solid solution opens research opportunities that are not accessible using bulk materials. We give details on the X-ray diffraction study on plutonium oxalate hexahydrate, as a reagent for the synthesis of such nanoparticles

The surgical approach of advanced esophageal cancers

Clinica l-a Chirurgi U.M.F, Iaşi, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Lucrarea este un studiu retrospectiv a neoplasmelor esofagiene internate în Clinica I Chirurgie Iaşi între 2000 - 2009. După trecerea în revistă a datelor generale (sex, vârstă, posibilități de explorare, decizii terapeutice) a celor 71 de cazuri de neoplasme esofagiene internate în ultimii 10 ani, sunt prezentate sintetic cazurile care au beneficiat de abord chirurgical. Sunt expuse elementele care au concurat la luarea unei anumite decizii terapeutice şi analizate evoluția şi complicațiile postoperatorii. Nu au fost incluse în observații tumorile eso-cardiotuberozitare care constituie un subiect al patologiei joncțiunii esogastrice. Procent de rezecabilitate al leziunilor avansate este extrem de redus (24,13%). Dacă în cancerele avansate pentru exereză nu se porneşte pe ideea radicalității oncologice, având în vedere vârsta şi fragilitatea acestor bolnavi considerăm utilă fracționatea gestului chirurgical în două sau trei etape, atitudine care pe seria noastră a redus mortalitatea perioperatorie. În cazurile inoperabile, by-pass-ul este o soluție valoroasă de rezolvare a disfagiei, dar complexitatea intervenției trebuie să pună în balanță beneficiul net al pacientului; de aceea se indică pentru bolnavii bine compensați biologic şi funcțional, de vârste acceptabile.The therapeutical option was adapted to each case so for resectable tumors we apply a multimodal approach in 21 cases, a palliative approach in 12 cases and gastro or jejunostomy in 25 cases.The location of resectable tumors was cervical in 3 cases, mid third of esophagus in 11 cases, inferior third of esophagus in 4 cases and multiple tumor locations in 3 cases. The T.N.M. stages of operated tumors were especially stage III with 14 cases, Stage I one case, Stage II, 2 cases and Stage IV. 4 cases. A R0 resection was realized in 17 cases associated with a two field lymphadenectomy. We perform the operations in one step in 14 cases and in two steps in 7 cases. Considering esophagectomy with esophagoplasty the best palliation for esophageal cancers, we consider very important to adapt the surgical technique to the nutritional and biological status of the patient. So performing the operation in two steps we succeed to improve the survival rate as shown in our group of patients. The post operative mortality is of 4% In case of unresectable esophageal lesion the eso-gastric by-pass represents a good relief of dysphagia. We recommend this palliative attitude in case of patients with a good nutritional and biological status.The authors present a retrospective study of 58 epidermoid esophageal cancers treated in the l st Surgical Clinic U.M.F. Iasi, in the last decade 2000-2009.The eso-cardial tumors are excluded. The resectability of epidermoid esophageal cancers at the moment of the diagnosis was about 24, 13 %.The tumor location was: upper third of esophagus 10 cases, mid esophagus 33 cases, inferior third of esophagus 12 cases, multiple 3 cases.51 cases (87, 9%) were complicated at the moment of the diagnosis: malnutrition 39 cases, bleeding 2 cases, pneumonia 6 cases (aspiration), eso-tracheal fistula 4 cases

Search for Intermediate Mass Magnetic Monopoles and Nuclearites with the SLIM experiment

SLIM is a large area experiment (440 m2) installed at the Chacaltaya cosmic ray laboratory since 2001, and about 100 m2 at Koksil, Himalaya, since 2003. It is devoted to the search for intermediate mass magnetic monopoles (107-1013 GeV/c2) and nuclearites in the cosmic radiation using stacks of CR39 and Makrofol nuclear track detectors. In four years of operation it will reach a sensitivity to a flux of about 10-15 cm-2 s-1 sr-1. We present the results of the calibration of CR39 and Makrofol and the analysis of a first sample of the exposed detector.Comment: Presented at the 22nd ICNTS, Barcelona 200