Formal Calibration Methodology for CFD Model Development to Support the Operation of Energy Efficient Buildings

Computational Fluid Dynamics (CFD) is a robust tool for modeling interactions within and between fluids and solids. CFD can help understand and predict phenomena that are difficult to test experimentally leading to cleaner, healthier, and better controlled internal environments. In this research a CFD model of the internal environment of an office space will be developed. The CFD model will then be calibrated using real data taken from a well-positioned wireless sensor network and weather station. The work focuses on developing systematically calibrated CFD models for controlled environments that include clean rooms, health environments, pharmaceutical storage rooms and information and communication technology locations, utilizing wireless sensor networks. The calibrated CFD model will be used to optimize the positions of the physical sensors for the control of energy efficient internal environments by building operators. This could result in significant energy and economic savings and lead to more accurately controlled internal environments

A narrative review to credible computational fluid dynamics models of naturally ventilated built environments

This narrative review describes the capabilities of computational fluid dynamics (CFD) to support the scientific analysis of fluid flows inside buildings, focusing on natural ventilation. The challenges posed by CFD, such as mesh generation, boundary conditions specification, choice of turbulence or radiation models and the ability to estimate the accuracy of results are explored. For the first time, this work provides a summary of verification and validation studies relating to CFD models of different built environments, and detailed validation studies of naturally ventilated spaces. This review summarises the most common guidelines and conclusions drawn from literature relating to CFD modelling of indoor environments that are naturally ventilated. The work demonstrates current practices in CFD simulation of naturally ventilated indoor environments, highlighting the importance of quality assured validation data to support the credibility of models. The review shows that, despite the presence of best practice guidelines for verification and validation of computational models, the grid verification was infrequently reported in the literature when presenting CFD results of indoor environmental conditions. Moreover, a third of reviewed validation studies were only qualitative and lacked specific validation criteria. Credible CFD analysis of natural ventilation strategies in buildings requires the ability to interpret strongly variable field measurements when specifying boundary conditions, other computational parameters and validating model results. This research provides a background and general guidelines for researchers who are commencing work in the field of CFD simulation of indoor environments for flow problems relating to natural ventilation

The Agrobacterium-mediated transformation of common wheat (Triticum aestivum L.) and triticale (x Triticosecale Wittmack): role of the binary vector system and selection cassettes

The influence of two binary vector systems, pGreen and pCAMBIA, on the Agrobacterium-mediated transformation ability of wheat and triticale was studied. Both vectors carried selection cassettes with bar or nptII driven by different promoters. Two cultivars of wheat, Kontesa and Torka, and one cultivar of triticale, Wanad, were tested. The transformation rates for the wheat cultivars ranged from 0.00 to 3.58% and from 0.00 to 6.79% for triticale. The best values for wheat were 3.58% for Kontesa and 3.14% for Torka, and these were obtained after transformation with the pGreen vector carrying the nptII selection gene under the control of 35S promoter. In the case of the bar selection system, the best transformation rates were, respectively, 1.46 and 1.79%. Such rates were obtained when the 35S::bar cassette was carried by the pCAMBIA vector; they were significantly lower with the pGreen vector. The triticale cultivar Wanad had its highest transformation rate after transformation with nptII driven by 35S in pCAMBIA. The bar selection system for the same triticale cultivar was better when the gene was driven by nos and the selection cassette was carried by pGreen. The integration of the transgenes was confirmed with at least three pairs of specific starters amplifying the fragments of nptII, bar, or gus. The expression of selection genes, measured by reverse transcriptase polymerase chain reaction (RT-PCR) in relation to the actin gene, was low, ranging from 0.00 to 0.63 for nptII and from 0.00 to 0.33 for bar. The highest relative transcript accumulation was observed for nptII driven by 35S and expressed in Kontesa that had been transformed with pGreen

Recombinant plants provide a new approach to the production of bacterial polysaccharide for vaccines

Bacterial polysaccharides have numerous clinical or industrial uses. Recombinant plants could offer the possibility of producing bacterial polysaccharides on a large scale and free of contaminating bacterial toxins and antigens. We investigated the feasibility of this proposal by cloning and expressing the gene for the type 3 synthase (cps3S) of Streptococcus pneumoniae in Nicotinia tabacum, using the pCambia2301 vector and Agrobacterium tumefaciens-mediated gene transfer. In planta the recombinant synthase polymerised plant-derived UDP-glucose and UDP-glucuronic acid to form type 3 polysaccharide. Expression of the cps3S gene was detected by RT-PCR and production of the pneumococcal polysaccharide was detected in tobacco leaf extracts by double immunodiffusion, Western blotting and high-voltage paper electrophoresis. Because it is used a component of anti-pneumococcal vaccines, the immunogenicity of the plant-derived type 3 polysaccharide was tested. Mice immunised with extracts from recombinant plants were protected from challenge with a lethal dose of pneumococci in a model of pneumonia and the immunised mice had significantly elevated levels of serum anti-pneumococcal polysaccharide antibodies. This study provides the proof of the principle that bacterial polysaccharide can be successfully synthesised in plants and that these recombinant polysaccharides could be used as vaccines to protect against life-threatening infections

HAP2(GCS1)-Dependent Gamete Fusion Requires a Positively Charged Carboxy-Terminal Domain

HAP2(GCS1) is a deeply conserved sperm protein that is essential for gamete fusion. Here we use complementation assays to define major functional regions of the Arabidopsis thaliana ortholog using HAP2(GCS1) variants with modifications to regions amino(N) and carboxy(C) to its single transmembrane domain. These quantitative in vivo complementation studies show that the N-terminal region tolerates exchange with a closely related sequence, but not with a more distantly related plant sequence. In contrast, a distantly related C-terminus is functional in Arabidopsis, indicating that the primary sequence of the C-terminus is not critical. However, mutations that neutralized the charge of the C-terminus impair HAP2(GCS1)-dependent gamete fusion. Our results provide data identifying the essential functional features of this highly conserved sperm fusion protein. They suggest that the N-terminus functions by interacting with female gamete-expressed proteins and that the positively charged C-terminus may function through electrostatic interactions with the sperm plasma membrane

Rapid in vivo analysis of synthetic promoters for plant pathogen phytosensing

<p>Abstract</p> <p>Background</p> <p>We aimed to engineer transgenic plants for the purpose of early detection of plant pathogen infection, which was accomplished by employing synthetic pathogen inducible promoters fused to reporter genes for altered phenotypes in response to the pathogen infection. Toward this end, a number of synthetic promoters consisting of inducible regulatory elements fused to a red fluorescent protein (RFP) reporter were constructed for use in phytosensing.</p> <p>Results</p> <p>For rapid analysis, an <it>Agrobacterium</it>-mediated transient expression assay was evaluated, then utilized to assess the inducibility of each synthetic promoter construct <it>in vivo</it>. Tobacco (<it>Nicotiana tabacum </it>cv. Xanthi) leaves were infiltrated with <it>Agrobacterium </it>harboring the individual synthetic promoter-reporter constructs. The infiltrated tobacco leaves were re-infiltrated with biotic (bacterial pathogens) or abiotic (plant defense signal molecules salicylic acid, ethylene and methyl jasmonate) agents 24 and 48 hours after initial agroinfiltration, followed by RFP measurements at relevant time points after treatment. These analyses indicated that the synthetic promoter constructs were capable of conferring the inducibility of the RFP reporter in response to appropriate phytohormones and bacterial pathogens, accordingly.</p> <p>Conclusions</p> <p>These observations demonstrate that the <it>Agrobacterium</it>-mediated transient expression is an efficient method for <it>in vivo </it>assays of promoter constructs in less than one week. Our results provide the opportunity to gain further insights into the versatility of the expression system as a potential tool for high-throughput <it>in planta </it>expression screening prior to generating stably transgenic plants for pathogen phytosensing. This system could also be utilized for temporary phytosensing; e.g., not requiring stably transgenic plants.</p

A new approach to ticagrelor-based de-escalation of antiplatelet therapy after acute coronary syndrome. A rationale for a randomized, double-blind, placebo-controlled, investigator-initiated, multicenter clinical study

© 2021 Via Medica. This article is available in open access under Creative Common Attribution-Non-Commercial-No Derivatives 4.0 International (CC BY-NC-ND 4.0) license. https://creativecommons.org/licenses/by/4.0/The risk of ischemic events gradually decreases after acute coronary syndrome (ACS), reaching a stable level after 1 month, while the risk of bleeding remains steady during the whole period of dual antiplatelet treatment (DAPT). Several de-escalation strategies of antiplatelet treatment aiming to enhance safety of DAPT without depriving it of its efficacy have been evaluated so far. We hypothesized that reduction of the ticagrelor maintenance dose 1 month after ACS and its continuation until 12 months after ACS may improve adherence to antiplatelet treatment due to better tolerability compared with the standard dose of ticagrelor. Moreover, improved safety of treatment and preserved anti-ischemic benefit may also be expected with additional acetylsalicylic acid (ASA) withdrawal. To evaluate these hypotheses, we designed the Evaluating Safety and Efficacy of Two Ticagrelor-based De-escalation Antiplatelet Strategies in Acute Coronary Syndrome — a randomized clinical trial (ELECTRA-SIRIO 2), to assess the influence of ticagrelor dose reduction with or without continuation of ASA versus DAPT with standard dose ticagrelor in reducing clinically relevant bleeding and main-taining anti-ischemic efficacy in ACS patients. The study was designed as a phase III, randomized, multicenter, double-blind, investigator-initiated clinical study with a 12-month follow-up.Peer reviewedFinal Published versio

Metabolic Engineering of Potato Carotenoid Content through Tuber-Specific Overexpression of a Bacterial Mini-Pathway

BACKGROUND: Since the creation of “Golden Rice”, biofortification of plant-derived foods is a promising strategy for the alleviation of nutritional deficiencies. Potato is the most important staple food for mankind after the cereals rice, wheat and maize, and is extremely poor in provitamin A carotenoids. METHODOLOGY: We transformed potato with a mini-pathway of bacterial origin, driving the synthesis of beta-carotene (Provitamin A) from geranylgeranyl diphosphate. Three genes, encoding phytoene synthase (CrtB), phytoene desaturase (CrtI) and lycopene beta-cyclase (CrtY) from Erwinia, under tuber-specific or constitutive promoter control, were used. 86 independent transgenic lines, containing six different promoter/gene combinations, were produced and analyzed. Extensive regulatory effects on the expression of endogenous genes for carotenoid biosynthesis are observed in transgenic lines. Constitutive expression of the CrtY and/or CrtI genes interferes with the establishment of transgenosis and with the accumulation of leaf carotenoids. Expression of all three genes, under tuber-specific promoter control, results in tubers with a deep yellow (“golden”) phenotype without any adverse leaf phenotypes. In these tubers, carotenoids increase approx. 20-fold, to 114 mcg/g dry weight and beta-carotene 3600-fold, to 47 mcg/g dry weight. CONCLUSIONS: This is the highest carotenoid and beta-carotene content reported for biofortified potato as well as for any of the four major staple foods (the next best event being “Golden Rice 2”, with 31 mcg/g dry weight beta-carotene). Assuming a beta-carotene to retinol conversion of 6∶1, this is sufficient to provide 50% of the Recommended Daily Allowance of Vitamin A with 250 gms (fresh weight) of “golden” potatoes