105 research outputs found
Analysis of Propane Gas Burner Experiments and FDS Simulations in a Two-Story Residential Structure with HVAC
To further our knowledge of fire dynamics in a residential structure with a heating, venitilation, and air conditioning (HVAC) system, a series of live fire gas burner experiments were conducted and modeling simulations were completed to compare the results. 29 full-scale experiments were conducted in a single story ranch structure on a basement with fire from a single propane fed gas burner. The
structure was instrumented to measure temperatures, oxygen and carbon dioxide concentrations, water vapor concentrations, and gas velocities. In addition to the full-scale experiments, six experiments were selected and modeled for comparison. A numerical simulation program, known as a Fire Dynamics Simulator (FDS) (version 6.7.10), was used to complete the computational fluid dynamics (CFD) calculations. The FDS HVAC submodel was incorporated into the modeled experiments to compare how heat and fire gases transversed the modeled HVAC system as compared to the experimental results. Results from experimental and simulated data showed
that heat and fire gases were transferred through the HVAC system during the experiments. Comparison of simulation data to the experimental data showed that FDS over predicted heat transfer through the HVAC system. However, there was sufficient agreement between data points to support FDS modeling as a more severe set of outcomes in the event of a fire
A Family of microRNAs Encoded by Myosin Genes Governs Myosin Expression and Muscle Performance
SummaryMyosin is the primary regulator of muscle strength and contractility. Here we show that three myosin genes, Myh6, Myh7, and Myh7b, encode related intronic microRNAs (miRNAs), which, in turn, control muscle myosin content, myofiber identity, and muscle performance. Within the adult heart, the Myh6 gene, encoding a fast myosin, coexpresses miR-208a, which regulates the expression of two slow myosins and their intronic miRNAs, Myh7/miR-208b and Myh7b/miR-499, respectively. miR-208b and miR-499 play redundant roles in the specification of muscle fiber identity by activating slow and repressing fast myofiber gene programs. The actions of these miRNAs are mediated in part by a collection of transcriptional repressors of slow myofiber genes. These findings reveal that myosin genes not only encode the major contractile proteins of muscle, but act more broadly to influence muscle function by encoding a network of intronic miRNAs that control muscle gene expression and performance
Damaging variants in FOXI3 cause microtia and craniofacial microsomia
Q1Q1Pacientes con Microtia y MicrosomÃa craneofacialPurpose:
Craniofacial microsomia (CFM) represents a spectrum of craniofacial malformations, ranging from isolated microtia with or without aural atresia to underdevelopment of the mandible, maxilla, orbit, facial soft tissue, and/or facial nerve. The genetic causes of CFM remain largely unknown.
Methods:
We performed genome sequencing and linkage analysis in patients and families with microtia and CFM of unknown genetic etiology. The functional consequences of damaging missense variants were evaluated through expression of wild-type and mutant proteins in vitro.
Results:
We studied a 5-generation kindred with microtia, identifying a missense variant in FOXI3 (p.Arg236Trp) as the cause of disease (logarithm of the odds = 3.33). We subsequently identified 6 individuals from 3 additional kindreds with microtia-CFM spectrum phenotypes harboring damaging variants in FOXI3, a regulator of ectodermal and neural crest development. Missense variants in the nuclear localization sequence were identified in cases with isolated microtia with aural atresia and found to affect subcellular localization of FOXI3. Loss of function variants were found in patients with microtia and mandibular hypoplasia (CFM), suggesting dosage sensitivity of FOXI3.
Conclusion:
Damaging variants in FOXI3 are the second most frequent genetic cause of CFM, causing 1% of all cases, including 13% of familial cases in our cohort.https://orcid.org/0000-0003-3822-7780https://orcid.org/0000-0002-0729-6866Revista Internacional - IndexadaA1N
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