262 research outputs found
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IMPROVING THE ENERGY PERFORMANCE OF RESIDENTIAL CLOTHESDRYERS
Experiments were conducted to evaluate four techniques to improve the energy efficiency of electrically-heated domestic clothes dryers. Reduced air flow rate and heater input led to energy savings around 8%, while recirculation of a portion of the exhaust air back into the clothes dryer reduced energy consumption by approximately 18%. These two measures are attractive because of their low cost. Two modes of using an air-to-air heat exchanger for heat recovery were considered. The first is to preheat the inlet air with heat from the exhaust air, which resulted in 20 to 26% energy savings. The second mode is 100% recirculation of air through the dryer and a heat exchanger and condensation of water from this air in the heat exchanger by using indoor air. as a heat sink. This resulted in 100% heat recovery (i.e., all heat was rejected to indoors) but the energy consumption of the dryer was increased by up to 6%. To maximize energy savings, a clothes dryer with a heat exchanger can be equipped to operate in the preheating mode in the summer and in the recirculation/condensation mode in the winter. The last measure investigated recirculation, through a heat pump (i.e., dehumidifier), also resulted in a 100% heat recovery and, in addition, up to a 33% reduction in dryer energy consumption, but this technique also yielded long drying times
Worm Epidemics in Wireless Adhoc Networks
A dramatic increase in the number of computing devices with wireless
communication capability has resulted in the emergence of a new class of
computer worms which specifically target such devices. The most striking
feature of these worms is that they do not require Internet connectivity for
their propagation but can spread directly from device to device using a
short-range radio communication technology, such as WiFi or Bluetooth. In this
paper, we develop a new model for epidemic spreading of these worms and
investigate their spreading in wireless ad hoc networks via extensive Monte
Carlo simulations. Our studies show that the threshold behaviour and dynamics
of worm epidemics in these networks are greatly affected by a combination of
spatial and temporal correlations which characterize these networks, and are
significantly different from the previously studied epidemics in the Internet
Fine Structure of the Sensilla and Immunolocalisation of Odorant Binding Proteins in the Cerci of the Migratory Locust, Locusta migratoria
Using light and electron microscopy (both scanning and transmission), we observed the presence of sensilla chaetica and hairs on the cerci of the migratory locust, Locusta migratoria L. (Orthoptera: Acrididae). Based on their fine structures, three types of sensilla chaetica were identified: long, medium, and short. Males presented significantly more numbers of medium and short sensilla chaetica than females (p<0.05). The other hairs can also be distinguished as long and short. Sensilla chaetica were mainly located on the distal parts of the cerci, while hairs were mostly found on the proximal parts. Several dendritic branches, enveloped by a dendritic sheath, are present in the lymph cavity of the sensilla chaetica. Long, medium, and short sensilla chaetica contain five, four and three dendrites, respectively. In contrast, no dendritic structure was observed in the cavity of the hairs. By immunocytochemistry experiments only odorant-binding protein 2 from L. migratoria (LmigOBP2) and chemosensory protein class I from the desert locust, Schistocerca gregaria Forsskål (SgreCSPI) strongly stained the outer lymph of sensilla chaetica of the cerci. The other two types of hairs were never labeled. The results indicate that the cerci might be involved in contact chemoreception processes
High JC virus load in tongue carcinomas may be a risk factor for tongue tumorigenesis
The John Cunningham virus (JCV) asymptomatically infects a large proportion (~90%) of the population worldwide but may be activated in immunodeficient patients, resulting in progressive multifocal leukoencephalopathy. Recent reports demonstrated its oncogenic role in malignancies. In this paper, the presence of JCV-targeting T antigen was investigated in tongue carcinoma (TC, n = 39), dysplastic tongue epithelium (DTE, n = 15) and glossitis (n = 15) using real-time polymerase chain reaction (PCR) and in situ PCR and immunohistochemistry, and JCV copies were analyzed with the clinicopathological parameters of TCs. The results demonstrated that glossitis and DTEs had significantly lower copies of JCV (410.5 ± 44.3 and 658.3 ± 53.3 copies/μg DNA respectively) than TCs (981.5 ± 14.0, p
< 0.05). When they were divided into three groups with 0–200 copies/μg DNA (low), 201–1,000 (moderate) and more than 1001 (high), TCs showed 3 (7.6%) in the low group, 21 (53.8%) in the moderate group and 15 (38.4%) in the high group and glossitis showed 11 (73.3%) in the low group, 0 (0%) in the moderate group and 4 (26.6%) in the high group. The DTEs occupied an intermediate position between them (p < 0.001). In situ PCR demonstrated that the nuclei of TC and DTE cells are sporadically T-antigen positive but not in nasal turbinate epithelial cells. Immunohistochemistry for T-antigen protein revealed four positive cases only in TCs. The existence of JCV T-antigen DNA was not associated with the clinicopathological variables of TCs. In conclusion, the presence of JCV may be a risk factor of tongue carcinogenesis
Homogenization Pressure and Temperature Affect Protein Partitioning and Oxidative Stability of Emulsions
The oxidative stability of 10 % fish oil-in-water emulsions was investigated for emulsions prepared under different homogenization conditions. Homogenization was conducted at two different pressures (5 or 22.5 MPa), and at two different temperatures (22 and 72 °C). Milk proteins were used as the emulsifier. Hence, emulsions were prepared with either a combination of α-lactalbumin and β-lactoglobulin or with a combination of sodium caseinate and β-lactoglobulin. Results showed that an increase in pressure increased the oxidative stability of emulsions with caseinate and β-lactoglobulin, whereas it decreased the oxidative stability of emulsions with α-lactalbumin and β-lactoglobulin. For both types of emulsions the partitioning of proteins between the interface and the aqueous phase appeared to be important for the oxidative stability. The effect of pre-heating the aqueous phase with the milk proteins prior to homogenization did not have any clear effect on lipid oxidation in either of the two types of emulsions. (Résumé d'auteur
Proteomics Reveals Novel Drosophila Seminal Fluid Proteins Transferred at Mating
Across diverse taxa, seminal fluid proteins (Sfps) transferred at mating affect the reproductive success of both sexes. Such reproductive proteins often evolve under positive selection between species; because of this rapid divergence, Sfps are hypothesized to play a role in speciation by contributing to reproductive isolation between populations. In Drosophila, individual Sfps have been characterized and are known to alter male sperm competitive ability and female post-mating behavior, but a proteomic-scale view of the transferred Sfps has been missing. Here we describe a novel proteomic method that uses whole-organism isotopic labeling to detect transferred Sfps in mated female D. melanogaster. We identified 63 proteins, which were previously unknown to function in reproduction, and confirmed the transfer of dozens of predicted Sfps. Relative quantification of protein abundance revealed that several of these novel Sfps are abundant in seminal fluid. Positive selection and tandem gene duplication are the prevailing forces of Sfp evolution, and comparative proteomics with additional species revealed lineage-specific changes in seminal fluid content. We also report a proteomic-based gene discovery method that uncovered 19 previously unannotated genes in D. melanogaster. Our results demonstrate an experimental method to identify transferred proteins in any system that is amenable to isotopic labeling, and they underscore the power of combining proteomic and evolutionary analyses to shed light on the complex process of Drosophila reproduction
Structure and function of a broad-specificity chitin deacetylase from <i>Aspergillus nidulans </i>FGSC A4
publishedVersio
Kinetics and Ligand-Binding Preferences of Mycobacterium tuberculosis Thymidylate Synthases, ThyA and ThyX
Mycobacterium tuberculosis kills approximately 2 million people each year and presents an urgent need to identify new targets and new antitubercular drugs. Thymidylate synthase (TS) enzymes from other species offer good targets for drug development and the M. tuberculosis genome contains two putative TS enzymes, a conventional ThyA and a flavin-based ThyX. In M. tuberculosis, both TS enzymes have been implicated as essential for growth, either based on drug-resistance studies or genome-wide mutagenesis screens. To facilitate future small molecule inhibitors against these proteins, a detailed enzymatic characterization was necessary.After cloning, overexpression, and purification, the thymidylate-synthesizing ability of ThyA and ThyX gene products were directly confirmed by HPLC analysis of reaction products and substrate saturation kinetics were established. 5-Fluoro-2'-deoxyuridine 5'-monophosphate (FdUMP) was a potent inhibitor of both ThyA and ThyX, offering important clues to double-targeting strategies. In contrast, the folate-based 1843U89 was a potent inhibitor of ThyA but not ThyX suggesting that it should be possible to find ThyX-specific antifolates. A turnover-dependent kinetic assay, combined with the active-site titration approach of Ackermann and Potter, revealed that both M. tuberculosis enzymes had very low k(cat) values. One possible explanation for the low catalytic activity of M. tuberculosis ThyX is that its true biological substrates remain to be identified. Alternatively, this slow-growing pathogen, with low demands for TMP, may have evolved to down-regulate TS activities by altering the turnover rate of individual enzyme molecules, perhaps to preserve total protein quantities for other purposes. In many organisms, TS is often used as a part of larger complexes of macromolecules that control replication and DNA repair.Thus, the present enzymatic characterization of ThyA and ThyX from M. tuberculosis provides a framework for future development of cell-active inhibitors and the biological roles of these TS enzymes in M. tuberculosis
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