Prenatal diagnosis of mosaic ring chromosome 16 - a rare event with uncertain prognosis

Ring chromosomes are rare cytogenetic findings (prenatal frequency ~ 0.0075%) often associated with an abnormal phenotype, depending of the chromosomal origin, genetic content and the presence of a mosaic. Supernumerary ring chromosome 16 [r(16)] is rarely observed and mosaicism makes the genotype/phenotype correlation difficult. We report a de novo mosaic r(16) detected after prenatal diagnosis in a woman referred for advanced maternal age. Multiplex ligation-dependent probe amplification (MLPA) for aneuploidy testing of chromosomes 13, 18, 21 and X was normal. Karyotype was 47,XX,+r[10]/46,XX[15]. Chromosomal microarray analysis (CMA) on DNA obtained from long-term cultured amniocytes did not detect any alterations. MLPA with a pericentromeric probe kit on an uncultured sample showed a chromosome 16 gain, encompassing 16p11.2 and 16q11.2 regions, including TGFB1I1, AHSP, VPS35 and ORC6 genes, leading to partial characterization of the r(16). Although no phenotype has been correlated with overexpression of these genes, the 16p11.2 region is associated with neurodevelopmental disorders. Nevertheless individuals with microduplication of 16p11.2 and normal development have been described. The lack of a precise definition of genetic content of the r(16) and its mosaic form leads to uncertain prognosis of clinical outcome.N/

Emission factors from residential combustion appliances burning Portuguese biomass fuels

Smoke from residential wood burning has been identified as a major contributor to air pollution, motivating detailed emission measurements under controlled conditions. A series of experiments were performed to compare the emission levels from two types of wood-stoves to those of fireplaces. Eight types of biomass were burned in the laboratory: wood from seven species of trees grown in the Portuguese forest (Pinus pinaster, Eucalyptus globulus, Quercus suber, Acacia longifolia, Quercus faginea, Olea europaea and Quercus ilex rotundifolia) and briquettes produced from forest biomass waste. Average emission factors were in the ranges 27.5–99.2 g CO kg 1, 552–1660 g CO2 kg 1, 0.66– 1.34 g NO kg 1, and 0.82–4.94 g hydrocarbons kg 1 of biomass burned (dry basis). Average particle emission factors varied between 1.12 and 20.06 g kg 1 biomass burned (dry basis), with higher burn rates producing significantly less particle mass per kg wood burned than the low burn rates. Particle mass emission factors from wood-stoves were lower than those from the fireplace. The average emission factors for organic and elemental carbon were in the intervals 0.24–10.1 and 0.18–0.68 g kg 1 biomass burned (dry basis), respectively. The elemental carbon content of particles emitted from the energyefficient ‘‘chimney type’’ logwood stove was substantially higher than in the conventional cast iron stove and fireplace, whereas the opposite was observed for the organic carbon fraction. Pinus pinaster, the only softwood species among all, was the biofuel with the lowest emissions of particles, CO, NO and hydrocarbons

Ash agglomeration and deposition during combustion of poultry litter in a bubbling fluidized-bed combustor

peer-reviewedn this study, we have characterized the ash resulting from fluidized bed combustion of poultry litter as being dominated by a coarse fraction of crystalline ash composed of alkali-Ca-phosphates and a fine fraction of particulate K2SO4 and KCl. Bed agglomeration was found to be coating-induced with two distinct layers present. The inner layer (0.05–0.09 mm thick) was formed due to the reaction of gaseous potassium with the sand (SiO2) surface forming K-silicates with low melting points. Further chemical reaction on the surface of the bed material strengthened the coating forming a molten glassy phase. The outer layer was composed of loosely bound, fine particulate ash originating from the char. Thermodynamic equilibrium calculations showed slag formation in the combustion zone is highly temperature-dependent, with slag formation predicted to increase from 1.8 kg at 600 °C to 7.35 kg at 1000 °C per hour of operation (5.21 kg of ash). Of this slag phase, SiO2 and K2O were the dominant phases, accounting for almost 95%, highlighting the role of K-silicates in initiating bed agglomeration. The remaining 5% was predicted to consist mainly of Al2O3, K2SO4, and Na2O. Deposition downstream in the low-temperature regions was found to occur mostly through the vaporization–condensation mechanism, with equilibrium decreasing significantly with decreasing temperatures. The dominant alkali chloride-containing gas predicted to form in the combustion zone was KCl, which corresponds with the high KCl content in the fine baghouse ash

Axial Concentration Profiles and NO Flue Gas in a Pilot-Scale Bubbling Fluidized Bed Coal Combustor

Atmospheric bubbling fluidized bed coal combustion of a bituminous coal and anthracite with particle diameters in the range 500-4000 ím was investigated in a pilot-plant facility. The experiments were conducted at steady-state conditions using three excess air levels (10, 25, and 50%) and bed temperatures in the 750-900 °C range. Combustion air was staged, with primary air accounting for 100, 80, and 60% of total combustion air. For both types of coal, high NO concentrations were found inside the bed. In general, the NO concentration decreased monotonically along the freeboard and toward the exit flue; however, during combustion with high air staging and low to moderate excess air, a significant additional NO formation occurred near the secondary air injection point. The results show that the bed temperature increase does not affect the NO flue gas concentration significantly. There is a positive correlation between excess air and the NO flue gas concentration. The air staging operation is very effective in lowering the NO flue gas, but there is a limit for the first stage stoichiometry below which the NO flue gas starts rising again. This effect could be related with the coal rank

Classification of the dup 15q13.3 CNV: A National data collection

Introduction: The proximal region 15q11q14 is one of the most unstable regions in the human genome, with six recognizable break points (BP1-BP6). In 15q13.3 there is a recurrent small CNV (BP4-BP5) consisting of a 350-680 Kb duplication, encompassing the CHRNA7 gene, which encodes the alpha 7 subunit of the neuronal nicotinic acetylcholine receptor. Although microdeletions of CHRNA7 are known to cause intellectual disability and neuropsychiatric phenotypes with high penetrance, the patogenicity of CHRNA7 duplications remains unclear. Microduplication 15q13.3 seems to be associated with a phenotypic spectrum of cognitive impairment and neuropsychiatric/neurobehavioral disorders. However, the penetrance of this CNV is considered incomplete since it is present in clinically unaffected individuals in the general population and it is frequently inherited from apparently clinically normal parents. Nonetheless, some pedigree studies have found a history of neuropsychiatric problems among carrier family members. This study aimed at re-evaluating the dup 15q13.3 CNV in national laboratories. Materials and Methods: Our study collected data on 15q13.3 microduplications in eight Portuguese genetics laboratories, among subjects referred for microarray. Results: Here we present a total of seventeen cases with dup 15q13.3. The subjects had somewhat variable phenotypes, with a bias towards developmental delay and autism spectrum disorders. Inheritance was established for eight of the subjects, and the majority originated from the father. We had no access to clinical data on carrier parents. No de novo CNV was found. All laboratories involved classified this variant as of uncertain significance. Discussion/Conclusion: To better determine whether this CNV is benign or pathogenic, careful characterization of patient and control cohorts must be performed, including detailed patient phenotyping, inheritance, clinical evaluation of carrier parents, prevalence in controls, as well as genetic functional studies. We strongly support the creation of a national database for uncertain CNVs in order to clarify the relevance of these recurrent findings, allowing a definitive classification in either pathogenic or benign

A comparative life cycle assessment of centralised and decentralised wood pellets production for residential heating

Recently, wood pellets have become a reliable and clean renewable fuel for residential heating, replacing fossil fuels and reducing greenhouse gas emissions. Wood pellets are normally produced in industrial pellet plants (centralised production), but decentralised small-scale local production also occurs. This study applies Life Cycle Assessment (LCA) to quantify and compare the environmental profile of one centralised and two decentralised alternatives for wood pellet production for residential heating in Portugal: (1) industrial wood pellets production (centralised), (2) wood pellets production at sawmills (decentralised) and (3) wood pellets production at households (decentralised). System boundaries include the stages of forest management, wood pellet production, wood pellet distribution and wood pellet energetic conversion. The impact results show that industrial pellet production ranks as the worst alternative, while pellet production at households has the best environmental profile for all the impact categories under study. However, the environmental impacts of pellet production at the sawmill do not differ greatly from those of the pellet production at households; they are 14 to 16% higher for global warming and fossil resources scarcity and 0.3 to 3% higher for the remaining impact categories. The worst environmental performance of the industrial pellet production alternative is mainly due to high electricity and diesel consumption during wood pellet production and the use of logging residues to generate heat for drying biomass feedstock. A sensitivity analysis was performed to evaluate the influence of changing the distance travelled during the transport of packed pellets to stores and sawdust to households. The results show changes in the environmental performance ranking, highlighting that for short distances, both decentralised alternatives can be more sustainable from an environmental perspective than the centralised alternative, but for larger distances, the pellet production at households should be avoided