Página 1 dos resultados de 155 itens digitais encontrados em 0.009 segundos

Corporate real estate strategies - a multinational approach

Ferreira, Pedro Manuel Costa dos Reis
Fonte: NSBE - UNL Publicador: NSBE - UNL
Tipo: Dissertação de Mestrado
Publicado em /01/2010 Português
Relevância na Pesquisa
56.51%
A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics; CRE strategies have proved to contribute to the creation of competitive advantages by integrating corporate value and the organizational culture across multi-locations. CRE strategies also facilitate attracting and retaining best talent. Through a qualitative research method of case study, this paper examines the impact of changes in the CRE strategies of McDonald’s and Hewlett Packard, both companies being multinational firms that represent the two main segments of CRE: retail and offices. Findings indicate that the changed strategies have provided for increased revenue and higher shareholder value in the case of McDonald’s and enhanced space utilization, comfortable working environment and a global design standard for all offices and workstations of HP. The study also analyzes the option of selling and leasing back CRE assets against owning them.

Generation of mice with a 200-kb amyloid precursor protein gene deletion by Cre recombinase-mediated site-specific recombination in embryonic stem cells.

Li, Z W; Stark, G; Götz, J; Rülicke, T; Gschwind, M; Huber, G; Müller, U; Weissmann, C
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 11/06/1996 Português
Relevância na Pesquisa
26.18%
Gene disruptions and deletions of up to 20kb have been generated by homologous recombination with appropriate targeting vectors in murine embryonic stem (ES) cells. Because we could not obtain a deletion of about 200 kb in the mouse amyloid precursor protein gene by the classical technique, we employed strategies involving the insertion of loxP sites upstream and downstream of the region to be deleted by homologous recombination and elicited excision of the loxP-flanked region by introduction of a Cre expression vector into the ES cells. In the first approach, the loxP sequences were inserted in two successive steps and after each step, ES cell clones were isolated and characterized. Deletion of the loxP-flanked sequence was accomplished by introducing the cre gene in a third step. In the second approach, ES cells containing the upstream loxP cassette were electroporated simultaneously with the downstream loxP targeting vector and the Cre expression plasmid. ES cells were obtained that gave rise to chimeric mice capable of germ-line transmission of the deleted amyloid precursor protein allele.

A single vector containing modified cre recombinase and LOX recombination sequences for inducible tissue-specific amplification of gene expression

Kaczmarczyk, Stanislaw J.; Green, Jeffrey E.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 15/06/2001 Português
Relevância na Pesquisa
26.23%
The selective alteration of the genome using Cre recombinase to target the rearrangement of genes flanked by LOX recognition sequences has required the use of two separate genetic constructs in trans, one containing cre and the other containing the gene of interest flanked by LOX sites. We have developed a strategy in which both the cre recombinase gene and LOX recombination sites may be cloned within a single vector in cis. This method uses a modified form of Cre (CREM) that contains alterations to the 5′ region including the introduction of a Kozak consensus sequence and insertion of a functional intron. This system allows for the inducible, tissue-specific activation or inactivation of gene expression in a single vector and can be utilized for the 300-fold amplification of gene expression from a weak promoter. This approach can be applied to targeting strategies for generating genetically altered mice and gene therapy.

Site-directed integration of the cre gene mediated by Cre recombinase using a combination of mutant lox sites

Araki, Kimi; Araki, Masatake; Yamamura, Ken-ichi
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 01/10/2002 Português
Relevância na Pesquisa
26.33%
The Cre-lox system is an important tool for genetic manipulation. To promote integrative reactions, two strategies using mutant lox sites have been developed. One is the left element/right element (LE/RE)-mutant strategy and the other is the cassette exchange strategy using heterospecific lox sites such as lox511 or lox2272. We compared the recombination efficiencies using these mutant lox sites in embryonic stem (ES) cells, and found that the combination of the LE/RE mutant and lox2272 showed high recombination efficiency and stability of the recombined structure. Taking advantage of this stability, we successfully integrated the cre gene into the mutant lox sites by Cre-mediated recombination. Germ line chimeric mice were produced from the cre-integrated ES cell clones, and Cre-expressing mouse lines were established. The inserted cre gene was stably maintained through the generations. This cre knock-in system using the LE/RE-lox2272 combination should be useful for the production of various cre mice for gene targeting or gene trapping.

Different thermostabilities of FLP and Cre recombinases: implications for applied site-specific recombination.

Buchholz, F; Ringrose, L; Angrand, P O; Rossi, F; Stewart, A F
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/11/1996 Português
Relevância na Pesquisa
26.26%
Genomic manipulations using site-specific recombinases rely on their applied characteristics in living systems. To understand their applied properties so that they can be optimally deployed, we compared the recombinases FLP and Cre in two assays. In both Escherichia coli and in vitro, FLP shows a different temperature optimum than Cre. FLP is more thermolabile, having an optimum near 30 degrees C and little detectable activity above 39 degrees C. Cre is optimally efficient at 37 degrees C and above. Consistent with FLP thermolability, recombination in a mammalian cell line mediated by a ligand- regulated FLP-androgen receptor fusion protein is more efficient at 35 degrees C than at higher temperatures. We also document a mutation in a commercially available FLP plasmid (FLP-F70L) which renders this recombinase even more thermolabile. The different temperature optima of FLP, FLP-F70L and Cre influence their strategies of usage. Our results recommend the use of Cre for applications in mice that require efficient recombination. The thermolabilities of FLP and FLP-F70L can be usefully exploited for gain of function and cell culture applications.

Cre Levels Limit Packaging Signal Excision Efficiency in the Cre/loxP Helper-Dependent Adenoviral Vector System

Ng, Philip; Evelegh, Carole; Cummings, Derek; Graham, Frank L.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /05/2002 Português
Relevância na Pesquisa
26.28%
Helper-dependent (HD) adenovirus vectors devoid of all viral coding sequences have a large cloning capacity and provide long-term transgene expression in vivo with negligible toxicity, making them attractive vectors for gene therapy. Currently, the most efficient means of producing HD vectors involves coinfecting 293 cells expressing Cre with the HD vector and a helper virus bearing a packaging signal flanked by loxP sites. Cre-mediated packaging signal excision renders the helper virus genome unpackageable but still able to replicate and provide helper functions for HD vector propagation. Typically, helper virus contamination is ≤1% pre- and ≤0.1% postpurification by CsCl banding. While these contamination levels are low, further reduction is desirable. However, this objective has not been realized since the Cre/loxP system was first developed. This lack of progress is due, at least in part, to our lack of understanding of the origins of the contaminating helper virus, thus rendering its reduction or elimination difficult to achieve. This study was designed to investigate the possible sources of contaminating helper virus persisting during HD vector amplification. The results revealed that Cre is limiting in helper virus-infected Cre-expressing 293 cells...

Cre-lox-regulated conditional RNA interference from transgenes

Ventura, Andrea; Meissner, Alexander; Dillon, Christopher P.; McManus, Michael; Sharp, Phillip A.; Van Parijs, Luk; Jaenisch, Rudolf; Jacks, Tyler
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.18%
We have generated two lentiviral vectors for conditional, Cre-lox-regulated, RNA interference. One vector allows for conditional activation, whereas the other permits conditional inactivation of short hairpin RNA (shRNA) expression. The former is based on a strategy in which the mouse U6 promoter has been modified by including a hybrid between a LoxP site and a TATA box. The ability to efficiently control shRNA expression by using these vectors was shown in cell-based experiments by knocking down p53, nucleophosmin and DNA methyltransferase 1. We also demonstrate the usefulness of this approach to achieve conditional, tissue-specific RNA interference in Cre-expressing transgenic mice. Combined with the growing array of Cre expression strategies, these vectors allow spatial and temporal control of shRNA expression in vivo and should facilitate functional genetic analysis in mammals.

Properties of a Telomerase-Specific Cre/Lox Switch for Transcriptionally Targeted Cancer Gene Therapy1

Bilsland, Alan E.; Fletcher-Monaghan, Aileen; Keith, W. Nicol
Fonte: Neoplasia Press, Inc. Publicador: Neoplasia Press, Inc.
Tipo: Artigo de Revista Científica
Publicado em /11/2005 Português
Relevância na Pesquisa
26.18%
Telomerase expression represents a good target for cancer gene therapy. The promoters of the core telomerase catalytic [human telomerase reverse transcriptase (hTERT)] and RNA [human telomerase RNA (hTR)] subunits show selective activity in cancer cells but not in normal cells. This property can be harnessed to express therapeutic transgenes in a wide range of cancer cells. Unfortunately, weak hTR and hTERT promoter activities in some cancer cells could limit the target cell range. Therefore, strategies to enhance telomerase-specific gene therapy are of interest. We constructed a Cre/Lox reporter switch coupling telomerase promoter specificity with Cytomegalovirus (CMV) promoter activity, which is generally considered to be constitutively high. In this approach, a telomerase-specific vector expressing Cre recombinase directs excisive recombination on a second vector, removing a transcriptional blockade to CMV-dependent luciferase expression. We tested switch activation in cell lines over a wide range of telomerase promoter activities. However, Cre/Lox–dependent luciferase expression was not enhanced relative to expression using hTR or hTERT promoters directly. Cell-specific differences between telomerase and CMV promoter activities and incomplete sigmoid switch activation were limiting factors. Notably...

Cre-lox-Based System for Multiple Gene Deletions and Selectable-Marker Removal in Lactobacillus plantarum▿

Lambert, Jolanda M.; Bongers, Roger S.; Kleerebezem, Michiel
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.31%
The classic strategy to achieve gene deletion variants is based on double-crossover integration of nonreplicating vectors into the genome. In addition, recombination systems such as Cre-lox have been used extensively, mainly for eukaryotic organisms. This study presents the construction of a Cre-lox-based system for multiple gene deletions in Lactobacillus plantarum that could be adapted for use on gram-positive bacteria. First, an effective mutagenesis vector (pNZ5319) was constructed that allows direct cloning of blunt-end PCR products representing homologous recombination target regions. Using this mutagenesis vector, double-crossover gene replacement mutants could be readily selected based on their antibiotic resistance phenotype. In the resulting mutants, the target gene is replaced by a lox66-P32-cat-lox71 cassette, where lox66 and lox71 are mutant variants of loxP and P32-cat is a chloramphenicol resistance cassette. The lox sites serve as recognition sites for the Cre enzyme, a protein that belongs to the integrase family of site-specific recombinases. Thus, transient Cre recombinase expression in double-crossover mutants leads to recombination of the lox66-P32-cat-lox71 cassette into a double-mutant loxP site, called lox72...

Expression of Conditional Cre Recombinase in Epithelial Tissues of Transgenic Mice

Wen, Fang; Cecena, Grace; Munoz-Ritchie, Varinia; Fuchs, Elaine; Chambon, Pierre; Oshima, Robert G.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /02/2003 Português
Relevância na Pesquisa
26.23%
Keratin 18 (K18) expression is a defining characteristic of internal epithelial cells of mammals. Here, we used the K18 gene and an internal ribosome entry site (IRES) to express green fluorescent protein, human placental alkaline phosphatase, and a modified Cre recombinase in an epithelial specific pattern in transgenic mice. The K18-driven alkaline phosphatase was expressed in liver, kidney, uterine endometrium, and other internal epithelia. The enzymatic activity of the Cre recombinase-mutant estrogen receptor fusion protein was dependent on tamoxifen administration and resulted in a mosaic pattern in internal epithelia, including bladder, uterus, liver, and kidney. This conditional Cre activity in internal epithelial organs should be valuable for strategies utilizing Cre for activation of gene expression. This study demonstrates that the tissue-specific, position-independent transcriptional activity of the K18 gene is not compromised by the use of an IRES element for the expression of a second protein from a bicistronic mRNA.

Transposition-Based Method for the Rapid Generation of Gene-Targeting Vectors to Produce Cre/Flp-Modifiable Conditional Knock-Out Mice

Turakainen, Hilkka; Saarimäki-Vire, Jonna; Sinjushina, Natalia; Partanen, Juha; Savilahti, Harri
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 05/02/2009 Português
Relevância na Pesquisa
26.13%
Conditional gene targeting strategies are progressively used to study gene function tissue-specifically and/or at a defined time period. Instrumental to all of these strategies is the generation of targeting vectors, and any methodology that would streamline the procedure would be highly beneficial. We describe a comprehensive transposition-based strategy to produce gene-targeting vectors for the generation of mouse conditional alleles. The system employs a universal cloning vector and two custom-designed mini-Mu transposons. It produces targeting constructions directly from BAC clones, and the alleles generated are modifiable by Cre and Flp recombinases. We demonstrate the applicability of the methodology by modifying two mouse genes, Chd22 and Drapc1. This straightforward strategy should be readily suitable for high-throughput targeting vector production.

The Use of Lentiviral Vectors and Cre/loxP to Investigate the Function of Genes in Complex Behaviors

Heldt, Scott A.; Ressler, Kerry J.
Fonte: Frontiers Research Foundation Publicador: Frontiers Research Foundation
Tipo: Artigo de Revista Científica
Publicado em 30/11/2009 Português
Relevância na Pesquisa
26.23%
The use of conventional knockout technologies has proved valuable for understanding the role of key genes and proteins in development, disease states, and complex behaviors. However, these strategies are limited in that they produce broad changes in gene function throughout the neuroaxis and do little to identify the effects of such changes on neural circuits thought to be involved in distinct functions. Because the molecular functions of genes often depend on the specific neuronal circuit in which they are expressed, restricting gene manipulation to specific brain regions and times may be more useful for understanding gene functions. Conditional gene manipulation strategies offer a powerful alternative. In this report we briefly describe two conditional gene strategies that are increasingly being used to investigate the role of genes in behavior – the Cre/loxP recombination system and lentiviral vectors. Next, we summarize a number of recent experiments which have used these techniques to investigate behavior after spatial and/or temporal and gene manipulation. These conditional gene targeting strategies provide useful tools to study the endogenous mechanisms underlying complex behaviors and to model disease states resulting from aberrant gene expression.

Use of Cre-adenovirus and CAR transgenic mice for efficient deletion of genes in post-thymic T cells

Zha, Yuanyuan; Shah, Ramila; Locke, Frederick; Wong, Austin; Gajewski, Thomas F.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.18%
Conditional gene deletion using lineage-specific transgenic expression of Cre has been useful for defining the role of specific gene products in mice in vivo. However, this technology has had limitations for studies of peripheral T cell biology, since the T-lineage promoters commonly used are active early in thymic development. As such, T cell development can be altered by the resulting genetic alterations, thus limiting the interpretation of the data in post-thymic T cell studies. Thus, new strategies are needed to delete targeted genes directly in peripheral T lymphocytes. The availability of transgenic mice expressing the CAR in the T cell compartment enabled testing of Cre-mediated recombination using an adenoviral vector in naïve peripheral T cells in vitro, even without cellular activation. Using Rosa26R reporter×CAR transgenic mice, we describe conditions by which Cre-mediated deletion of targeted genes can be achieved with primary T cells in vitro. These cells can also be adoptively transferred into defined recipient mice for study in vivo. We use conditional PTEN-deficient mice as proof of concept to confirm the value of this technique for deleting a negative regulator of T cell activation. This technology should be broadly applicable for studies of T cell specific gene deletion to gain understanding of function in the post-thymic T cell compartment.

Site-Specific Recombination Strategies for Engineering Actinomycete Genomes

Herrmann, Simone; Siegl, Theresa; Luzhetska, Marta; Petzke, Lutz; Jilg, Caroline; Welle, Elisabeth; Erb, Annette; Leadlay, Peter F.; Bechthold, Andreas; Luzhetskyy, Andriy
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /03/2012 Português
Relevância na Pesquisa
26.36%
The feasibility of using technologies based on site-specific recombination in actinomycetes was shown several years ago. Despite their huge potential, these technologies mostly have been used for simple marker removal from a chromosome. In this paper, we present different site-specific recombination strategies for genome engineering in several actinomycetes belonging to the genera Streptomyces, Micromonospora, and Saccharothrix. Two different systems based on Cre/loxP and Dre/rox have been utilized for numerous applications. The activity of the Cre recombinase on the heterospecific loxLE and loxRE sites was similar to its activity on wild-type loxP sites. Moreover, an apramycin resistance marker flanked by the loxLERE sites was eliminated from the Streptomyces coelicolor M145 genome at a surprisingly high frequency (80%) compared to other bacteria. A synthetic gene encoding the Dre recombinase was constructed and successfully expressed in actinomycetes. We developed a marker-free expression method based on the combination of phage integration systems and site-specific recombinases. The Cre recombinase has been used in the deletion of huge genomic regions, including the phenalinolactone, monensin, and lipomycin biosynthetic gene clusters from Streptomyces sp. strain Tü6071...

Intersectional Cre Driver Lines Generated Using Split-Intein Mediated Split-Cre Reconstitution

Wang, Ping; Chen, Tianrui; Sakurai, Katsuyasu; Han, Bao-Xia; He, Zhigang; Feng, Guoping; Wang, Fan
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em 06/07/2012 Português
Relevância na Pesquisa
26.34%
Tissue and cell type highly specific Cre drivers are very rare due to the fact that most genes or promoters used to direct Cre expressions are generally expressed in more than one tissues and/or in multiple cell types. We developed a split-intein based split-Cre system for highly efficient Cre-reconstitution through protein splicing. This split-intein-split-Cre system can be used to intersect the expression patterns of two genes or promoters to restrict full-length Cre reconstitution in their overlapping domains. To test this system in vivo, we selected several conserved human enhancers to drive the expression of either Cre-N-intein-N, or intein-C-Cre-C transgene in different brain regions. In all paired CreN/CreC transgenic mice, Cre-dependent reporter was efficiently induced specifically in the intersectional expression domains of two enhancers. This split-intein based method is simpler to implement compared with other strategies for generating highly-restricted intersectional Cre drivers to study complex tissues such as the nervous system.

Pancreas-specific Cre driver lines and considerations for their prudent use

Magnuson, Mark A.; Osipovich, Anna B.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 02/07/2013 Português
Relevância na Pesquisa
26.18%
Cre/LoxP has broad utility for studying the function, development and oncogenic transformation of pancreatic cells in mice. Here we provide an overview of the many different Cre driver lines that are available for such studies. We, discuss how variegated expression, transgene silencing, and recombination in undesired cell types have conspired to limit the performance of these lines sometimes leading to serious experimental concerns. We also discuss. preferred strategies for achieving high fidelity driver lines and remind investigators of the continuing need for caution when interpreting results obtained from any Cre/LoxP-based experiment performed in mice.

Applications of the site-specific recombinase Cre to the study of genomic imprinting

Oh-McGinnis, Rosemary; Jones, Meaghan J.; Lefebvre, Louis
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.18%
The development of gene targeting approaches has had a tremendous impact on the functional analysis of the mouse genome. A specific application of this technique has been the adaptation of the bacteriophage P1 Cre/loxP site-specific recombinase system which allows for the precise recombination between two loxP sites, resulting in deletion or inversion of the intervening sequences. Because of the efficiency of this system, it can be applied to conditional deletions of relatively short coding sequences or regulatory elements but also to more extensive chromosomal rearrangement strategies. Both mechanistic and functional studies of genomic imprinting have benefited from the development of the Cre/loxP technology. Since imprinted genes within large chromosomal regions are regulated by the action of cis-acting sequences known as imprinting centres, chromosomal engineering approaches are particularly well suited to the elucidation of long-range mechanisms controlling the imprinting of autosomal genes. Here we review the applications of the Cre/loxP technology to the study of genomic imprinting, highlight important insights gained from these studies and discuss future directions in the field.

Strategies to construct null and conditional null Trypanosoma brucei mutants using Cre-recombinase and loxP

Kim, Hee-Sook; Li, Zhen; Boothroyd, Catharine; Cross, George A. M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.23%
We describe two gene-knockout (KO) strategies in Trypanosoma brucei using Cre recombinase and loxP sites. Due to the limited number of selection markers for T. brucei, it has been difficult to generate a mutant with two genes knocked out and impractical to simultaneously knockout more than two genes, deterring detailed studies of important cellular mechanisms. The first KO strategy described can overcome the marker problem by allowing continuous re-use of drug-resistance markers. The same KO vector can be used to make a conditional KO system, when a gene of interest is essential for cell viability. As a gene of interest is removed from its original chromosomal locus by the induction of Cre recombinase, deletion is complete and instantaneous. This makes it easier to identify primary effects rather than having secondary effects obscuring phenotypic assessment, as is often the case with RNAi silencing.

Development of a Simple and Efficient System for Excising Selectable Markers in Arabidopsis Using a Minimal Promoter::Cre Fusion Construct

Kim, Hyun-Bi; Cho, Jung-Il; Ryoo, Nayeon; Qu, Shaohong; Wang, Guo-Liang; Jeon, Jong-Seong
Fonte: Korea Society for Molecular and Cellular Biology Publicador: Korea Society for Molecular and Cellular Biology
Tipo: Artigo de Revista Científica
Português
Relevância na Pesquisa
26.23%
The development of rapid and efficient strategies to generate selectable marker-free transgenic plants could help increase the consumer acceptance of genetically modified (GM) plants. To produce marker-free transgenic plants without conditional treatment or the genetic crossing of offspring, we have developed a rapid and convenient DNA excision method mediated by the Cre/loxP recombination system under the control of a -46 minimal CaMV 35S promoter. The results of a transient expression assay showed that -46 minimal promoter::Cre recombinase (-46::Cre) can cause the loxP-specific excision of a selectable marker, thereby connecting the 35S promoter and β-glucuronidase (GUS) reporter gene. Analysis of stable transgenic Arabidopsis plants indicated a positive correlation between loxP-specific DNA excision and GUS expression. PCR and DNA gel-blot analysis further revealed that nine of the 10 tested T1 transgenic lines carried both excised and nonexcised constructs in their genomes. In the subsequent T2 generation plants, over 30% of the individuals for each line were marker-free plants harboring the excised construct only. These results demonstrate that the -46::Cre fusion construct can be efficiently and easily utilized for producing marker-free transgenic plants.

Experimental and numerical study on the evaluation of ventilation efficiency

Monteiro, Joaquim Fernandes
Fonte: Instituto Politécnico do Porto. Instituto Superior de Engenharia do Porto Publicador: Instituto Politécnico do Porto. Instituto Superior de Engenharia do Porto
Tipo: Dissertação de Mestrado
Publicado em //2013 Português
Relevância na Pesquisa
26.23%
Buildings account for 40% of total energy consumption in the European Union. The reduction of energy consumption in the buildings sector constitute an important measure needed to reduce the Union's energy dependency and greenhouse gas emissions. The Portuguese legislation incorporate this principles in order to regulate the energy performance of buildings. This energy performance should be accompanied by good conditions for the occupants of the buildings. According to EN 15251 (2007) the four factors that affect the occupant comfort in the buildings are: Indoor Air Quality (IAQ), thermal comfort, acoustics and lighting. Ventilation directly affects all except the lighting, so it is crucial to understand the performance of it. The ventilation efficiency concept therefore earn significance, because it is an attempt to quantify a parameter that can easily distinguish the different options for air diffusion in the spaces. The two indicators most internationally accepted are the Air Change Efficiency (ACE) and the Contaminant Removal Effectiveness (CRE). Nowadays with the developed of the Computational Fluid Dynamics (CFD) the behaviour of ventilation can be more easily predicted. Thirteen strategies of air diffusion were measured in a test chamber through the application of the tracer gas method...