Analysis and inactivation of vha55, the gene encoding the vacuolar ATPase B-subunit in Drosophila melanogaster reveals a larval lethal phenotype.

Vacuolar ATPases play major roles in endomembrane and plasma membrane proton transport in eukaryotes. A Drosophila melanogaster cDNA encoding vha55, the 55-kDa vacuolar ATPase (V-ATPase) regulatory B-subunit, was characterized and mapped to 87C2-4 on chromosome 3R. A fly line was identified that carried a single lethal P-element insertion within the coding portion of gene, and its LacZ reporter gene revealed elevated expression in Malpighian tubules, rectum, antennal palps, and oviduct, regions where V-ATPases are believed to play a plasma membrane, rather than an endomembrane, role. The P-element vha55 insertion was shown to be allelic to a known lethal complementation group l(3)SzA (= l(3)87Ca) at 87C, for which many alleles have been described previously. Deletions of the locus have been shown to be larval lethal, whereas point mutations show a range of phenotypes from subvital to embryonic lethal, implying that severe alleles confer a partial dominant negative phenotype. The P-element null allele of vha55 was shown also to suppress ectopic sex combs in Polycomb males, suggesting that transcriptional silencing may be modulated by genes other than those with known homeotic or DNA binding functions

Performance of Different Experimental Absorber Designs in Absorption Heat Pump Cycle Technologies: A Review

The absorber is a major component of absorption cycle systems, and its performance directly impacts the overall size and energy supplies of these devices. Absorption cooling and heating cycles have different absorber design requirements: in absorption cooling systems, the absorber works close to ambient temperature, therefore, the mass transfer is the most important phenomenon in order to reduce the generator size; on the other hand, in heat transformer absorption systems, is important to recover the heat delivered by exothermic reactions produced in the absorber. In this paper a review of the main experimental results of different absorber designs reported in absorption heat pump cycles is presented

Improving sustainable office building operation by using historical data and linear models to predict energy usage

Offices and retail outlets represent the most intensive energy consumers in the non-residential building sector and have been estimated to account for more than 50% of a building's energy usage. Accurate predictions of office building energy usage can provide potential energy savings and significantly enhance the efficient energy management of office buildings. This paper proposes a method that applies multiple linear regression (MLR) and artificial neural network (ANN) models to predict energy consumption based on weather conditions and occupancy; thus, enabling a comparison of the use of these two types of modelling methods. In this study, four models of office sites at research institutions in different New Zealand regions were developed to investigate the ability of simple models to reduce margins of error in energy auditing projects. The models were developed based on the monthly average outside temperature and the number of full-time employees (FTEs). A comparison of the actual and predicted energy usage revealed that the models can predict energy usage within an acceptable error range. The results also demonstrated that each building should be investigated as an individual unit