28 results on '"G. Florin"'
Search Results
2. Microbial Lipid Alternatives to Plant Lipids
- Author
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A Daniel, Jones, Kyria L, Boundy-Mills, G Florin, Barla, Sandeep, Kumar, Bryan, Ubanwa, and Venkatesh, Balan
- Subjects
Bacteria ,Lipidomics ,Fungi ,Microalgae ,Plants ,Lipid Metabolism ,Lipids ,Chemistry Techniques, Analytical - Abstract
Lipids are in high demand in food production, nutritional supplements, detergents, lubricants, and biofuels. Different oil seeds produced from plants are conventionally extracted to yield lipids. With increasing population and reduced availability of cultivable land, conventional methods of producing lipids alone will not satisfy increasing demand. Lipids produced using different microbial sources are considered as sustainable alternative to plant derived lipids. Various microorganisms belonging to the genera of algae, bacteria, yeast, fungi, or marine-derived microorganisms such as thraustochytrids possess the ability to accumulate lipids in their cells. A variety of microbial production technologies are being used to cultivate these organisms under specific conditions using agricultural residues as carbon source to be cost competitive with plant derived lipids. Microbial oils, also known as single cell oils, have many advantages when compared with plant derived lipids, such as shorter life cycle, less labor required, season and climate independence, no use of arable land and ease of scale-up. In this chapter we compare the lipids derived from plants and different microorganisms. We also highlight various analytical techniques that are being used to characterize the lipids produced in oleaginous organisms and their applications in various processes.
- Published
- 2019
3. Microbial Lipid Alternatives to Plant Lipids
- Author
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G Florin Barla, Bryan Ubanwa, Sandeep Kumar, Venkatesh Balan, A. Daniel Jones, and Kyria Boundy-Mills
- Subjects
0301 basic medicine ,education.field_of_study ,biology ,business.industry ,Microorganism ,010401 analytical chemistry ,Population ,biology.organism_classification ,01 natural sciences ,Yeast ,0104 chemical sciences ,03 medical and health sciences ,030104 developmental biology ,Algae ,Agriculture ,Biofuel ,Food processing ,lipids (amino acids, peptides, and proteins) ,Food science ,education ,business ,Bacteria - Abstract
Lipids are in high demand in food production, nutritional supplements, detergents, lubricants, and biofuels. Different oil seeds produced from plants are conventionally extracted to yield lipids. With increasing population and reduced availability of cultivable land, conventional methods of producing lipids alone will not satisfy increasing demand. Lipids produced using different microbial sources are considered as sustainable alternative to plant derived lipids. Various microorganisms belonging to the genera of algae, bacteria, yeast, fungi, or marine-derived microorganisms such as thraustochytrids possess the ability to accumulate lipids in their cells. A variety of microbial production technologies are being used to cultivate these organisms under specific conditions using agricultural residues as carbon source to be cost competitive with plant derived lipids. Microbial oils, also known as single cell oils, have many advantages when compared with plant derived lipids, such as shorter life cycle, less labor required, season and climate independence, no use of arable land and ease of scale-up. In this chapter we compare the lipids derived from plants and different microorganisms. We also highlight various analytical techniques that are being used to characterize the lipids produced in oleaginous organisms and their applications in various processes.
- Published
- 2019
4. MINI IRENE - Deployable Heat Shield for Suborbital Flight Test
- Author
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Roberto Gardi, Paolo Vernillo, Alberto Fedele, Giuseppe Pezzella, Raffaele Savino, Pasquale Dell’Aversana, Luciano Gramiccia, Giovanni D’Aniello, Renato Aurigemma, Nicola Cimminiello, Francesco Punzo, G. Florin, Rafael Molina, R. Gardi, P. Vernillo, A. Fedele, G. Pezzella, R. Savino, P. Dell’Aversana, L. Gramiccia, G. D’aniello, R. Aurigemma, N. Cimminiello, F. Punzo, G. Florin, R. Molina, Gardi, R., Vernillo, P., Fedele, A., Pezzella, G., Savino, R., Dell’Aversana, P., Gramiccia, L., D’Aniello, G., Aurigemma, R., Cimminiello, N., Punzo, F., Florin, G., Molina, R., Gardi, Roberto, Vernillo, Paolo, Fedele, Alberto, Pezzella, Giuseppe, Savino, Raffaele, Dell’Aversana, Pasquale, Gramiccia, Luciano, D’Aniello, Giovanni, Aurigemma, Renato, Cimminiello, Nicola, Punzo, Francesco, and Molina, Rafael
- Abstract
MINI Irene is the Flight Demonstrator of IRENE, a new-concept capsule with a variable geometry, originally conceived by ASI to widen the range of available platforms to retrieve payloads and/or data from low Earth orbit. This paper, after a short introduction of the patented IRENE deployable heat shield concept and benefits, shows the ongoing activities that will lead to the sub-orbital flight. The description is focused on the structural activities, both numerical and experimental), and on the avionic systems.
- Published
- 2017
5. The Odin satellite - II. Radiometer data processing and calibration
- Author
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Åke Hjalmarson, Alain Lecacheux, Steve Torchinsky, Urban Frisk, A. O. H. Olofsson, G. Florin, Michael Olberg, Philippe Baron, David Teyssier, Bengt Larsson, Kevin Volk, Aa. Sandqvist, Donal P. Murtagh, Laurent Pagani, Per Bergman, G. Olofsson, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Ingénieurs, Techniciens et Administratifs, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Physique des plasmas, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), and Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Physics ,Data processing ,Radiometer ,Astronomy and Astrophysics ,telescopes ,techniques : spectroscopic ,[SDU]Sciences of the Universe [physics] ,Space and Planetary Science ,Calibration ,Satellite ,submillimeter ,Fixed frequency ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,space vehicles : instruments ,Remote sensing - Abstract
The radiometer on-board the Odin satellite comprises four different sub-mm receivers covering the 486 - 581 GHz frequency range and one fixed frequency 119 GHz receiver. Two auto-correlators and one acousto-optical spectrometer serve as backends. This article gives an overview over the processing of the data delivered by these instruments and discusses calibration issues.
- Published
- 2003
6. The Odin satellite
- Author
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U. Frisk, M. Hagström, J. Ala-Laurinaho, S. Andersson, J.-C. Berges, J.-P. Chabaud, M. Dahlgren, A. Emrich, H.-G. Florén, G. Florin, M. Fredrixon, T. Gaier, R. Haas, T. Hirvonen, Å. Hjalmarsson, B. Jakobsson, P. Jukkala, P. S. Kildal, E. Kollberg, J. Lassing, A. Lecacheux, P. Lehikoinen, A. Lehto, J. Mallat, C. Marty, D. Michet, J. Narbonne, M. Nexon, M. Olberg, A. O. H. Olofsson, G. Olofsson, A. Origné, M. Petersson, P. Piironen, R. Pons, D. Pouliquen, I. Ristorcelli, C. Rosolen, G. Rouaix, A. V. Räisänen, G. Serra, F. Sjöberg, L. Stenmark, S. Torchinsky, J. Tuovinen, C. Ullberg, E. Vinterhav, N. Wadefalk, H. Zirath, P. Zimmermann, R. Zimmermann, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique des plasmas, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris
- Subjects
Physics ,Heterodyne ,Radiometer ,Astronomy and Astrophysics ,law.invention ,Telescope ,[SDU]Sciences of the Universe [physics] ,Space and Planetary Science ,law ,Extremely high frequency ,Calibration ,Satellite ,Millimeter ,Spectral resolution ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] ,Remote sensing - Abstract
The Sub-millimetre and Millimetre Radiometer (SMR) is the main instrument on the Swedish, Canadian, Finnish and French spacecraft Odin. It consists of a 1.1 metre diameter telescope with four tuneable heterodyne receivers covering the ranges 486-504 GHz and 541-581 GHz, and one fixed at 118.75 GHz together with backends that provide spectral resolution from 150 kHz to 1 MHz. This Letter describes the Odin radiometer, its operation and performance with the data processing and calibration described in Paper II.
- Published
- 2003
7. The Rate of Organ and Tissue Donation After Brain Death: Causes of Donation Failure in a Romanian University City
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R. Neagu, M. Blaj, C. Craus, I. Grigoras, O. Chelarescu, and G. Florin
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Brain Death ,medicine.medical_specialty ,Pediatrics ,Tissue and Organ Procurement ,Urban Population ,Declaration ,Brain stem death ,Tissue Donation ,Cause of Death ,medicine ,Humans ,Organ donation ,Retrospective Studies ,Cause of death ,Transplantation ,Informed Consent ,Romania ,business.industry ,Patient Selection ,Sudden cardiac arrest ,medicine.disease ,Death, Sudden, Cardiac ,Spain ,Virus Diseases ,Donation ,Emergency medicine ,Tissue and Organ Harvesting ,Surgery ,medicine.symptom ,business - Abstract
Aim To evaluate the rate of organ donation after brain death in 2 tertiary care medical centers of a Romanian city, the reasons for donation exclusion (donors or organs), and identification of potential strategies for improvement. Material and Methods The study retrospectively evaluated potential organ donors with brain death (BD) who were identified between January 2006 and June 2009 in an university city of Romania. The potential donors were considered patients with severe intracranial pathology and clinical signs of brain death who were reported to the regional transplant team. The BD declaration was completed according to the Law of Transplant Procurement and Management in Romania: clinical signs of brain stem death, apnea test, and flat EEG, criteria that must be fulfilled twice at a 6 hour interval. According to Romanian law, family consent is mandatory for organ harvesting. Results The study included 35 potential donors, of whom 22 had a declaration of BD. Failure of potential donors to be declared BD was caused by positive viral serology (n = 7), improvement in clinical status (n = 2), sudden cardiac arrest (n = 2), and refusal of physician in charge (n = 2). Among the 22 with a BD declaration, organ harvesting was performed in only 12 cases due to family refusal (n = 10). In 4 cases the planned organ harvesting was aborted owing to unexpected intraoperative findings. Discussion Factors that generate the low rate of organ procurement include local organizational particularities, a high rate of viral infections, poor education, (both of lay persons and of medical personnel), restrictive criteria for BD declaration and the mandatory need for family approval. Conclusion The rate of donation in this university city of Romania is still low. Several strategies have been identified to improve the rate: better identification of potential donors, better management, and education of the public and of health care personnel.
- Published
- 2010
8. Presumed consent for organ donation: is Romania prepared for it?
- Author
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M. Blaj, C. Condac, I. Grigoras, G. Florin, and C. Cartes
- Subjects
medicine.medical_specialty ,Legislation, Medical ,Tissue and Organ Procurement ,media_common.quotation_subject ,Public debate ,Legislation ,Public opinion ,Denial ,medicine ,Humans ,Ethics, Medical ,Organ donation ,Mass Media ,media_common ,Transplantation ,Internet ,Organizations ,business.industry ,Romania ,Politics ,Legislature ,Public relations ,Altruism ,Surgery ,Donation ,Perception ,business ,Presumed Consent - Abstract
Introduction. In November 2007, a legislative initiative regarding the presumed consent for organ donation was proposed for parliamentary debate in Romania and was followed by public debate. The study aimed to asses public opinions expressed in the Romanian media. Materials and Methods. An Internet search was made. The pro and con reasons, the affiliation of parts involved in the debate and suggested future direction of action were identified. Results. The Internet search had 8572 results. The parts involved in the pro and con debate consisted of governmental structures, physicians, ethicists, politicians, media, religious authorities, nongovernmental associations, and lay persons. The main pros were the low rate of organ donation and the long waiting lists, enhancement of organ procurement, avoidance of wasting valuable organs, avoiding responsibility, and the stress imposed to the family in giving the donation consent, humanitarian purposes (saving lives), going along with the scientific progress, and less bureaucracy. The main cons were an unethical issue, violation of human rights, denial of brain death, unethical advantage of public ignorance, unethical use of underprivileged people, little results in terms of organ procurement, but huge negative effects on public opinion, public mistrust in transplant programs and impossibility of refusal identification due to particularities of the Romanian medical system. Conclusion. The con opinions prevailed. For the moment, Romania seems to be unprepared to accept presumed consent. A future change in public perception regarding organ transplantation may modify the terms of a public debate.
- Published
- 2010
9. A new way to design causally and totally ordered multicast protocols
- Author
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G. Florin C. Toinard
- Subjects
Protocol Independent Multicast ,Multicast ,business.industry ,Computer science ,Distributed computing ,Distance Vector Multicast Routing Protocol ,Broadcasting ,Source-specific multicast ,Multicast address ,General Earth and Planetary Sciences ,Xcast ,Unicast ,business ,General Environmental Science ,Computer network - Abstract
Multicast protocols must often provide a given property on the order in which messages are delivered. This delivery order may be consistent with local dependences between messages or with causal dependences. A local delivery is defined according to the emitting order observed at the same process source. A causal delivery is defined according to the causal relations observed between different emitting events. If an arbitrary delivery order is applied (when there are no particular dependences) the multicast is said to be totally ordered. In this paper we study totally and causally ordered multicast protocols i.e. multicast protocols that guarantee a total order conforming with the causal dependences. We propose a new method that begins to build a total order to obtain a causal and total multicast, when all current methods propose to build first a causal order then a total order (developed using the services of this causal layer).This new approach results from a formal study of ordering properties. In the first main result we show that a broadcast that guarantees a local and total order also provides a causal broadcast. Then we show that a multicast protocol that guarantees a local and a total order with additional constraints is also a causal and total multicast. This result makes no assumption about structure of overlapping groups. We finally develop the scheme of a multicast protocol using a centralized server of order. This solution is efficient in terms of messages and delay for a small number of sites. It allows all types of messages (unicast, multicast, broadcast) to mix while getting a causal and total ordering.
- Published
- 1992
10. Generalization of queueing network product form solutions to stochastic Petri nets
- Author
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S. Natkin and G. Florin
- Subjects
Strongly connected component ,Queueing theory ,Markov chain ,Computer science ,Stochastic process ,Distributed computing ,Stochastic Petri net ,Probability distribution ,Gordon–Newell theorem ,Petri net ,Topology ,Queue ,Software - Abstract
A new solution is given for the steady-state probability computation of closed synchronized queuing networks. A closed synchronized queuing network is a particular Markov stochastic Petri net (a bounded and monovaluated Petri net with a strongly connected reachability graph and constant firing rates independent of markings). It is shown that the steady-state probability distribution can be expressed using matrix products. The results generalize the Gordon-Newell theorem. The solution is similar to the Gordon-Newell product form using matrix and vectors instead of scalars. A prototype solver developed from this result is presented. >
- Published
- 1991
11. Matrix product form solution for closed synchronized queuing networks
- Author
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G. Florin and S. Natkin
- Subjects
Discrete mathematics ,Matrix (mathematics) ,Strongly connected component ,Markov chain ,Computer science ,Stochastic Petri net ,Probability distribution ,Petri net ,Product-form solution ,Topology ,Matrix multiplication - Abstract
A new solution is presented for the steady-state probability computing of closed synchronized queuing networks. A closed synchronized queuing network is a particular Markov stochastic Petri net (bounded and monovaluated Petri net with a strongly connected reachability graph and constant firing rates independent of markings). The authors show that the steady-state probability distribution can be expressed using matrix products. The results generalize the Gordon-Newell theorem. The solution is similar to the Gordon-Newell product form solution using a matrix and vectors instead of scalars. A prototype solver developed from the preceding result is presented. >
- Published
- 2003
12. Recursive distributed programming schemes
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R. Gomez, G. Florin, and I. Lavallee
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Concurrency control ,Theoretical computer science ,Iterative method ,Computer science ,Distributed algorithm ,Distributed computing ,Message passing ,Distributed concurrency control ,Distributed object ,Failure semantics ,Flooding (computer networking) - Abstract
Distributed recursive waves, a distributed programming scheme based on a procedure that calls n (or none) concurrent executions of itself, is defined. Three kinds of recursive waves (sequential, based on a tree, based on a flooding) and the example of a distributed recursive termination, respectively, are presented. Distributed recursive programming provides a natural style for writing distributed algorithms. It does not support the overhead drawback of the centralized computer recursivity. Solutions to distributed problems using the message passing wave approach or the distributed iteration scheme can also be expressed in the distributed recursive approach with the same message complexity. >
- Published
- 2002
13. Probabilistic validation using worst event driven and importance sampling simulation
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S. Natkin, N. Bennacer, and G. Florin
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symbols.namesake ,Computer science ,Stochastic process ,Stochastic Petri net ,Probabilistic logic ,symbols ,Markov process ,Petri net ,Discrete event simulation ,Algorithm ,Importance sampling ,Event (probability theory) ,Reliability engineering - Abstract
Probabilistic validation is an approach for the validation of highly dependable and complex systems. It relies on a partial analysis on a system model and tries to prove that the failed event occurrences has a sufficiently low probability. We define a probabilistic validation method using worst event driven and an importance sampling simulation. The system which must be validated is modeled by a stochastic Petri net. An efficient simulation of the net must be able to sample complex and improbable trajectories which eventually reach critical markings. Two problems have to be solved. The sequence of transition firings which may lead to critical markings must be characterized ad the Petri net level. The second problem is to sample these sequences and to build an accurate estimate of the incorrect behavior probability. We discuss several simulation algorithms in the Markovian and non-Markovian cases. We show the effectiveness of these techniques on the validation of several examples. >
- Published
- 2002
14. A statistical clock synchronization algorithm for anisotropic networks
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S. Natkin, G. Florin, and D. Couvet
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Offset (computer science) ,Computer science ,Vector clock ,Clock drift ,Isotropy ,Matrix clock ,Discrete event simulation ,Anisotropy ,Algorithm ,Clock synchronization - Abstract
A method to estimate the value of remote clocks in distributed systems is proposed. The method is able to deal with isotropic and anisotropic networks and includes a way to detect performance failures on single exchanges. It uses a statistical approach to estimate the relative drift of clocks and a round trip clock reading protocol to compute the offset. A good precision can be attained and maintained without exchanging too many specific extra messages. Numerical results obtained from a discrete event simulation are presented. >
- Published
- 2002
15. A new way to design causally and totally ordered multicast protocols
- Author
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Toinard, G. Florin C., primary
- Published
- 1992
- Full Text
- View/download PDF
16. RDPS: A Software Package for the Validation and Evaluation of Dependable Computer Systems
- Author
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P. Lone, S. Natkin, G. Florin, and J.M. Toudic
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Theoretical computer science ,Computer science ,business.industry ,Reachability ,Distributed computing ,Stochastic Petri net ,Dependability ,The Internet ,Petri net ,Software package ,business ,Random variable ,Astrophysics::Galaxy Astrophysics - Abstract
This paper presents the software tool RDPS. The first application of RDPS is the validation of synchronized systems modelled by Petri nets. Petri nets are described using a programming language (DEOL). RDPS computes the invariants of the net, generates the reachability graph, and analyzes several properties of the graph. The second application is the evaluation of performance or dependability parameters using stochastic Petri net theory. The user can define various random variables associated with the performance or dependability parameters of a system. RDPS computes steady state or transient moments of these variables. The paper presents an example of a practical dependability study of a complex fault-tolerant system.
- Published
- 1986
17. One-place unbounded stochastic petri nets: Ergodic criteria and steady-state solutions
- Author
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G. Florin and S. Natkin
- Subjects
Discrete mathematics ,Markov chain ,Stochastic process ,Ergodicity ,Markov process ,Petri net ,symbols.namesake ,Hardware and Architecture ,symbols ,Stochastic Petri net ,Ergodic theory ,Algorithm ,Software ,Information Systems ,Mathematics ,Incidence (geometry) - Abstract
This paper presents the analysis of Markov stochastic Petri nets having one unbounded place. These nets represent queues the arrival and departure of customers of which can be grouped and depend on a finite homogeneous Markov process. In the first section we give a formal definition of these nets, called C-Q nets (complex-queue nets), and we state some qualitative properties of such nets (particularly we state that the reachability graph is composed by an infinite sequence of isomorphic subgraphs). In the second section we give a complete classification of ergodic properties of C-Q nets. The Markov process associated with the marking are transient, null recurrent, and positive recurrent, according to the sign of the scalar quantity C"1, N"m"a"x (where C"1 is the incidence vector of the unbounded place p"1, N"m"a"x is the maximal expected firing rate of transitions of the net). The third section is devoted to the computation of the steady-state probabilities of C-Q nets. Because the generator of the marking process is a quasi-birth-and-death matrix, we recall the results for such processes (matrix geometric solution). We present the solution based on the generalized eigenvalues. The particular structure of the generator associated to a C-Q net induces a third method to compute the steady-state probabilities that are more efficient for grouped arrival and departure.
- Published
- 1986
18. Necessary and sufficient ergodicity condition for open synchronized queueing networks
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G. Florin and S. Natkin
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Queueing theory ,Markov chain ,Computer science ,Stochastic modelling ,Distributed computing ,Ergodicity ,Markov process ,Petri net ,Topology ,Computer Science::Performance ,symbols.namesake ,Layered queueing network ,Stochastic Petri net ,symbols ,Queue ,Software - Abstract
A necessary and sufficient ergodicity condition for complex open queueing systems is given. The queueing networks considered belong to a particular class of unbounded Markov stochastic Petri nets. These systems can include synchronization features like fork and join arrivals and departures, and feedback between behavior of different queues. Grouped and correlated arrivals and departures are also allowed. An example and a proof of the ergodicity results are presented. >
- Published
- 1989
19. Processing of oilseeds using fluidbed technology
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G. Florin and H. R. Bartesch
- Subjects
Process (engineering) ,Computer science ,business.industry ,General Chemical Engineering ,Organic Chemistry ,business ,Investment (macroeconomics) ,Manufacturing engineering ,Biotechnology - Abstract
The introduction of fluidbed technology in processing soybeans is discussed. Particular emphasis is given to energy and investment savings which are most significant with the newly developed EW-dehulling-conditioning process.
- Published
- 1983
20. Microgravity Effect on Pancreatic Islets.
- Author
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Zeger L, Barasa P, Han Y, Hellgren J, Redwan IN, Reiche ME, Florin G, Christoffersson G, and Kozlova EN
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- Animals, Mice, Insulin-Secreting Cells cytology, Insulin-Secreting Cells metabolism, Printing, Three-Dimensional, Cell Proliferation, Weightlessness, Islets of Langerhans cytology, Islets of Langerhans metabolism
- Abstract
We previously demonstrated that boundary cap neural crest stem cells (BCs) induce the proliferation of beta-cells in vitro, increase survival of pancreatic islets (PIs) in vivo after transplantation, and themselves strongly increase their proliferation capacity after exposure to space conditions. Therefore, we asked if space conditions can induce the proliferation of beta-cells when PIs are alone or together with BCs in free-floating or 3D-printed form. During the MASER 15 sounding rocket experiment, half of the cells were exposed to 6 min of microgravity (µg), whereas another group of cells were kept in 1 g conditions in a centrifuge onboard. The proliferation marker EdU was added to the cells just before the rocket reached µg conditions. The morphological assessment revealed that PIs successfully survived and strongly proliferated, particularly in the free-floating condition, though the fusion of PIs hampered statistical analysis. Proliferation of beta-cells was displayed in 3D-printed islets two weeks after µg exposure, suggesting that the effects of µg may be delayed. Thus, PIs in 3D-printed scaffolds did not fuse, and this preparation is more suitable than free-floating specimens for morphological analysis in µg studies. PIs maintained their increased proliferation capacity for weeks after µg exposure, an effect that may not appear directly, but can emerge after a delay.
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- 2024
- Full Text
- View/download PDF
21. Effects of microgravity on neural crest stem cells.
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Han Y, Barasa P, Zeger L, Salomonsson SB, Zanotti F, Egli M, Zavan B, Trentini M, Florin G, Vaerneus A, Aldskogius H, Fredriksson R, and Kozlova EN
- Abstract
Exposure to microgravity (μg) results in a range of systemic changes in the organism, but may also have beneficial cellular effects. In a previous study we detected increased proliferation capacity and upregulation of genes related to proliferation and survival in boundary cap neural crest stem cells (BC) after MASER14 sounding rocket flight compared to ground-based controls. However, whether these changes were due to μg or hypergravity was not clarified. In the current MASER15 experiment BCs were exposed simultaneously to μg and 1 g conditions provided by an onboard centrifuge. BCs exposed to μg displayed a markedly increased proliferation capacity compared to 1 g on board controls, and genetic analysis of BCs harvested 5 h after flight revealed an upregulation, specifically in μg-exposed BCs, of Zfp462 transcription factor, a key regulator of cell pluripotency and neuronal fate. This was associated with alterations in exosome microRNA content between μg and 1 g exposed MASER15 specimens. Since the specimens from MASER14 were obtained for analysis with 1 week's delay, we examined whether gene expression and exosome content were different compared to the current MASER15 experiments, in which specimens were harvested 5 h after flight. The overall pattern of gene expression was different and Zfp462 expression was down-regulated in MASER14 BC μg compared to directly harvested specimens (MASER15). MicroRNA exosome content was markedly altered in medium harvested with delay compared to directly collected samples. In conclusion, our analysis indicates that even short exposure to μg alters gene expression, leading to increased BC capacity for proliferation and survival, lasting for a long time after μg exposure. With delayed harvest of specimens, a situation which may occur due to special post-flight circumstances, the exosome microRNA content is modified compared to fast specimen harvest, and the direct effects from μg exposure may be partially attenuated, whereas other effects can last for a long time after return to ground conditions., Competing Interests: GF and AV were employed by Swedish Space Corporation. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Han, Barasa, Zeger, Salomonsson, Zanotti, Egli, Zavan, Trentini, Florin, Vaerneus, Aldskogius, Fredriksson and Kozlova.)
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- 2024
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22. Molecular genetic analysis of neural stem cells after space flight and simulated microgravity on earth.
- Author
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Han Y, Zeger L, Tripathi R, Egli M, Ille F, Lockowandt C, Florin G, Atic E, Redwan IN, Fredriksson R, and Kozlova EN
- Subjects
- Animals, Mice, Mice, Transgenic, Tissue Engineering, Gene Expression Regulation, Neural Stem Cells metabolism, Space Flight, Tissue Scaffolds chemistry, Weightlessness, Weightlessness Simulation
- Abstract
Understanding how stem cells adapt to space flight conditions is fundamental for human space missions and extraterrestrial settlement. We analyzed gene expression in boundary cap neural crest stem cells (BCs), which are attractive for regenerative medicine by their ability to promote proliferation and survival of cocultured and co-implanted cells. BCs were launched to space (space exposed cells) (SEC), onboard sounding rocket MASER 14 as free-floating neurospheres or in a bioprinted scaffold. For comparison, BCs were placed in a random positioning machine (RPM) to simulate microgravity on earth (RPM cells) or were cultured under control conditions in the laboratory. Using next-generation RNA sequencing and data post-processing, we discovered that SEC upregulated genes related to proliferation and survival, whereas RPM cells upregulated genes associated with differentiation and inflammation. Thus, (i) space flight provides unique conditions with distinctly different effects on the properties of BC compared to earth controls, and (ii) the space flight exposure induces postflight properties that reinforce the utility of BC for regenerative medicine and tissue engineering., (© 2021 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals LLC.)
- Published
- 2021
- Full Text
- View/download PDF
23. Preliminary Results of an Astri/UWM EGNSS Receiver Antenna Calibration Facility.
- Author
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Dawidowicz K, Rapiński J, Śmieja M, Wielgosz P, Kwaśniak D, Jarmołowski W, Grzegory T, Tomaszewski D, Janicka J, Gołaszewski P, Wolak B, Baryła R, Krzan G, Stępniak K, Florin-Catalin G, and Brzostowski K
- Abstract
In 2019, the University of Warmia and Mazury in Olsztyn, in cooperation with Astri Polska, started a European Space Agency (ESA) project. The purpose of the project is the development and implementation of a field calibration procedure for a multi-frequency and multi-system global navigation satellite system (GNSS). The methodology and algorithms proposed in the project are inspired by the "Hannover" concept of absolute field receiver antenna calibration; however, some innovations are introduced. In our approach, the antenna rotation point is close to the nominal mean phase center (MPC) of the antenna, although it does not coincide with it. Additionally, a National Marine Electronics Association local time zone (NMEA ZDA) message is used to synchronize the robot with the GNSS time. We also propose some modifications in robot arm movement scenarios. Our first test results demonstrate consistent performance for the calibration strategy and calibration procedure. For the global positioning system (GPS) L1 frequency, the calibration results show good agreement with the IGS-type mean values. For high satellite elevations (20°-90°), the differences do not exceed 1.5 mm. For low elevation angles (0°-20°), the consistency of the results is worse and the differences exceed a 3 mm level in some cases.
- Published
- 2021
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24. Microbial Lipid Alternatives to Plant Lipids.
- Author
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Jones AD, Boundy-Mills KL, Barla GF, Kumar S, Ubanwa B, and Balan V
- Subjects
- Bacteria metabolism, Chemistry Techniques, Analytical methods, Fungi metabolism, Lipid Metabolism, Lipidomics methods, Microalgae chemistry, Microalgae metabolism, Plants metabolism, Bacteria chemistry, Fungi chemistry, Lipids chemistry, Plants chemistry
- Abstract
Lipids are in high demand in food production, nutritional supplements, detergents, lubricants, and biofuels. Different oil seeds produced from plants are conventionally extracted to yield lipids. With increasing population and reduced availability of cultivable land, conventional methods of producing lipids alone will not satisfy increasing demand. Lipids produced using different microbial sources are considered as sustainable alternative to plant derived lipids. Various microorganisms belonging to the genera of algae, bacteria, yeast, fungi, or marine-derived microorganisms such as thraustochytrids possess the ability to accumulate lipids in their cells. A variety of microbial production technologies are being used to cultivate these organisms under specific conditions using agricultural residues as carbon source to be cost competitive with plant derived lipids. Microbial oils, also known as single cell oils, have many advantages when compared with plant derived lipids, such as shorter life cycle, less labor required, season and climate independence, no use of arable land and ease of scale-up. In this chapter we compare the lipids derived from plants and different microorganisms. We also highlight various analytical techniques that are being used to characterize the lipids produced in oleaginous organisms and their applications in various processes.
- Published
- 2019
- Full Text
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25. Efficient siRNA delivery system using carboxilated single-wall carbon nanotubes in cancer treatment.
- Author
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Neagoe IB, Braicu C, Matea C, Bele C, Florin G, Gabriel K, Veronica C, and Irimie A
- Subjects
- Cell Survival genetics, Drug Delivery Systems, Hep G2 Cells, Humans, Nanotubes, Carbon ultrastructure, Neoplasms pathology, Tumor Necrosis Factor-alpha genetics, Tumor Necrosis Factor-alpha metabolism, Tumor Suppressor Protein p53 biosynthesis, Tumor Suppressor Protein p53 genetics, Tumor Suppressor Protein p53 metabolism, Vascular Endothelial Growth Factors genetics, Vascular Endothelial Growth Factors metabolism, Gene Silencing, Nanotubes, Carbon chemistry, Neoplasms genetics, Neoplasms therapy, RNA, Small Interfering administration & dosage, RNA, Small Interfering genetics, Transfection methods
- Abstract
Several functionalized carbon nanotubes have been designed and tested for the purpose of nucleic acid delivery. In this study, the capacity of SWNTC-COOH for siRNA deliverey were investigated delivery in parallel with an efficient commercial system. Hep2G cells were reverse-transfected with 50 nM siRNA (p53 siRNA, TNF-alphasiRNA, VEGFsiRNA) using the siPORT NeoFX (Ambion) transfection agent in paralel with SWNTC-COOH, functionalised with siRNA. The highest level of gene inhibition was observed in the cases treated with p53 siRNA gene; in the case of transfection with siPort, the NeoFX value was 33.8%, while in the case of SWNTC-COOH as delivery system for p53 siRNA was 37.5%. The gene silencing capacity for VEGF was 53.7%, respectively for TNF-alpha 56.7% for siPORT NeoFX delivery systems versus 47.7% (VEGF) and 46.5% (TNF-alpha) for SWNTC-COOH delivery system. SWNTC-COOH we have been showed to have to be an efficient carrier system. The results from the inhibition of gene expresion for both transfection systems were confirmed at protein level. Overall, the lowest mRNA expression was confirmed at protein level, especially in the case of p53 siRNA and TNF-alpha siRNA transfection. Less efficient reduction protein expressions were observed in the case of VEGF siRNA, for both transfection systems at 24 h; only at 48 h, there was a statistically significant reduction of VEGF protein expression. SWCNT-COOH determined an efficient delivery of siRNA. SWNTC-COOH, combined with suitable tumor markers like p53 siRNA, TNFalpha siRNA or VEGF siRNA can be used for the efficient delivery of siRNA.
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- 2012
- Full Text
- View/download PDF
26. Presumed consent for organ donation: is Romania prepared for it?
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Grigoras I, Condac C, Cartes C, Blaj M, and Florin G
- Subjects
- Altruism, Ethics, Medical, Humans, Internet, Legislation, Medical, Mass Media, Organizations, Perception, Politics, Romania, Presumed Consent legislation & jurisprudence, Tissue and Organ Procurement legislation & jurisprudence
- Abstract
Introduction: In November 2007, a legislative initiative regarding the presumed consent for organ donation was proposed for parliamentary debate in Romania and was followed by public debate. The study aimed to asses public opinions expressed in the Romanian media., Materials and Methods: An Internet search was made. The pro and con reasons, the affiliation of parts involved in the debate and suggested future direction of action were identified., Results: The Internet search had 8572 results. The parts involved in the pro and con debate consisted of governmental structures, physicians, ethicists, politicians, media, religious authorities, nongovernmental associations, and lay persons. The main pros were the low rate of organ donation and the long waiting lists, enhancement of organ procurement, avoidance of wasting valuable organs, avoiding responsibility, and the stress imposed to the family in giving the donation consent, humanitarian purposes (saving lives), going along with the scientific progress, and less bureaucracy. The main cons were an unethical issue, violation of human rights, denial of brain death, unethical advantage of public ignorance, unethical use of underprivileged people, little results in terms of organ procurement, but huge negative effects on public opinion, public mistrust in transplant programs and impossibility of refusal identification due to particularities of the Romanian medical system., Conclusion: The con opinions prevailed. For the moment, Romania seems to be unprepared to accept presumed consent. A future change in public perception regarding organ transplantation may modify the terms of a public debate.
- Published
- 2010
- Full Text
- View/download PDF
27. The rate of organ and tissue donation after brain death: causes of donation failure in a Romanian university city.
- Author
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Grigoraş I, Blaj M, Florin G, Chelarescu O, Craus C, and Neagu R
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- Cause of Death, Death, Sudden, Cardiac, Humans, Informed Consent statistics & numerical data, Patient Selection, Retrospective Studies, Romania, Spain, Tissue and Organ Harvesting methods, Urban Population statistics & numerical data, Virus Diseases epidemiology, Brain Death, Tissue and Organ Procurement statistics & numerical data
- Abstract
Aim: To evaluate the rate of organ donation after brain death in 2 tertiary care medical centers of a Romanian city, the reasons for donation exclusion (donors or organs), and identification of potential strategies for improvement., Material and Methods: The study retrospectively evaluated potential organ donors with brain death (BD) who were identified between January 2006 and June 2009 in an university city of Romania. The potential donors were considered patients with severe intracranial pathology and clinical signs of brain death who were reported to the regional transplant team. The BD declaration was completed according to the Law of Transplant Procurement and Management in Romania: clinical signs of brain stem death, apnea test, and flat EEG, criteria that must be fulfilled twice at a 6 hour interval. According to Romanian law, family consent is mandatory for organ harvesting., Results: The study included 35 potential donors, of whom 22 had a declaration of BD. Failure of potential donors to be declared BD was caused by positive viral serology (n = 7), improvement in clinical status (n = 2), sudden cardiac arrest (n = 2), and refusal of physician in charge (n = 2). Among the 22 with a BD declaration, organ harvesting was performed in only 12 cases due to family refusal (n = 10). In 4 cases the planned organ harvesting was aborted owing to unexpected intraoperative findings., Discussion: Factors that generate the low rate of organ procurement include local organizational particularities, a high rate of viral infections, poor education, (both of lay persons and of medical personnel), restrictive criteria for BD declaration and the mandatory need for family approval., Conclusion: The rate of donation in this university city of Romania is still low. Several strategies have been identified to improve the rate: better identification of potential donors, better management, and education of the public and of health care personnel.
- Published
- 2010
- Full Text
- View/download PDF
28. Functional improvement between brain death declaration and organ harvesting.
- Author
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Grigoras I, Blaj M, Chelarescu O, Craus C, and Florin G
- Subjects
- Acid-Base Equilibrium, Blood Coagulation, Brain Death legislation & jurisprudence, Brain Injuries, Cardiovascular System physiopathology, Cause of Death, Graft Survival, Humans, Kidney Function Tests, Liver Function Tests, Romania, Time Factors, Tissue and Organ Harvesting standards, Tissue and Organ Procurement methods, Tissue and Organ Procurement statistics & numerical data, Brain Death physiopathology, Tissue and Organ Harvesting methods
- Abstract
Introduction: The quality of harvested organs is crucial for graft survival and for posttransplant evolution. This study sought to investigate the evolution of the functional status of brain death (BD) patients during the period between declaration and organ harvesting (BD duration)., Materials and Methods: The study included all BD patients who underwent organ harvesting between January 2006 and June 2009. We compared the functional status regarding hemodynamics, respiration, kidney and liver function, coagulation, water, electrolytes, and acid-base balance evaluated at the moment of BD declaration (P1) and just before organ harvesting (P2). The results of the comparison were expressed as improvement, stable, or aggravation. We calculated mean values of the functional parameters in P1 and P2 and the statistical significance of the differences., Results: Twelve BD patients were included in the study. The time interval between P1 and P2 was 16.08 +/- 8.54 hours (range, 6-32). The number of patients with vasopressor support was 9/12 at P1 and 0/12 at P2, oxygenation disturbances 1/12 in P1 and 0/12 in P2, renal dysfunction 9/12 in P1 and 2/12 in P2, liver dysfunction 7/12 in P1 and 1/12 in P2, coagulopathy 4/12 in P1 and 0/12 in P2, hypernatremia 8/12 in P1 and 3/12 in P2, and metabolic acidosis 9/12 in P1 and 1/12 in P2. The overall assessment showed improvement in all patients. The most statistically significant improvement was registered in the cardiovascular, respiratory, renal, liver, and acid-base status (P < .05)., Conclusion: With early, aggressive, protocolized donor management, functional improvement may be achieved during BD duration.
- Published
- 2010
- Full Text
- View/download PDF
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