169 research outputs found

    Assessing Ghanaian Workplace Performance in Multi-Storey Office Buildings.

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    The effects of the work space environment on worker productivity as well as comfort and work space quality have been widely researched into and have gained much importance with the European “Energy Performance of Buildings Directive” of 2001. Within the framework of a study on the ‘Thermal Performance of Multi-Storey Office Buildings”, 195 occupants in such buildings were surveyed before, during, and at the end of a 12 month monitoring period. The objective of the study was to find out how occupants measured their work spaces and to what extent did the work environment affect their day to day activities.  Data loggers were mounted in selected offices to record indoor physical parameters. 4 office buildings in Accra were selected for the study: 3 air-conditioned and 1 naturally ventilated building. The results indicated among others that whiles 2 of the air-conditioned buildings were comfortable, 1 was interestingly uncomfortable together with the naturally ventilated building. Moreover, about 80% of the occupants’ with open plan workstations expressed dissatisfaction about their spaces commenting that they lack privacy whiles those in enclosed offices had positive comments about their spaces. Furthermore, the users ranked air quality, thermal comfort, and fire safety among others in order of importance as features needed for successful operation of multi-storey office buildings. Thermal comfort was ranked to have a higher importance than acoustic comfort but not air quality. In terms of health complaints, general fatigue, neck pains, stiffness of limbs and backache were amongst the frequently experienced problems. The study would inform building operators/managers on the efficient ways of organising work spaces for occupant satisfaction and maximizing productivity. Keywords: Comfort, Occupants, Health, Air quality, Indoor environment

    Indoor Thermal Environment: Occupants Responsiveness in 4 Multi-Storey Office Buildings in Accra, Ghana.

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    The issue of comfort and workplace environment satisfaction within office buildings is fast becoming important and has gain interest by a lot of researchers. Since modern day office building designs (in Ghana) have resorted to the use of extensive glazing which contribute to the adverse indoor climate. This paper presents the results of a study of four multi-storey office buildings in Ghana with regards to occupants’ evaluation of their indoor environmental conditions. The buildings comprise of one naturally ventilated (World Trade Centre) and three mechanically ventilated office blocks (Ridge Towers, Heritage Towers and Premier Towers). Occupants in each building filled in a questionnaire to document their perception regarding indoor environment while some thermal and acoustical parameters were measured. Furthermore, the respondents expressed their feelings on the 7-point ASHRAE thermal sensation scale, to determine their Actual Mean Votes (AMV). Altogether, 195 occupants’ filled the questionnaire. The data and responses were analysed descriptively with MS Excel. The outcomes amongst others showed that in the naturally ventilated office, a good agreement could be seen with adaptive comfort models whiles in the air-conditioned offices, 97.1% of the occupants felt that their offices were cool. Again, only one out of the four office buildings met the standard criteria for lighting which is 500 lux. The sound levels measured also suggested that one building was not comfortable in terms of acoustic comfort. Both lighting and acoustic inefficiency may affect productivity. Attention to user perceptions and behaviour could improve the quality of the indoor environment in office buildings Keywords: Occupants’, Indoor environment, Naturally ventilated, Air-conditioned, Actual Mean Vote

    Chemical penetration enhancers in situ-forming reservoirs for trans-tympanic drug delivery : progress toward improved treatment of Otitis media

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    Thesis (Ph. D.)--Harvard-MIT Division of Health Sciences and Technology, 2008.Includes bibliographical references.Otitis media (OM) is the most common specifically-treated childhood disease in the United States. The widespread use of systemic antibiotics against a disease of such high incidence is believed to be a driving force behind the observed increase in adaptive resistance among pathogenic bacteria in the nasopharynx. Local, sustained delivery of antimicrobial agents to the site of infection allows for higher drug concentrations and optimized release profiles than are permitted by systemic administration. Higher antimicrobial concentrations sustained for longer periods of time also allow for a faster and more complete eradication of OM bacteria (e.g., H. influenzae, S. pneumoniae), and minimize antibiotic exposure to other bacteria and natural flora in the nasopharynx and upper respiratory tract. We have developed in situ-forming hydrogels to serve as sustained release reservoirs for noninvasive trans-tympanic treatment of OM. A hydrogel that includes potentially synergistic chemical penetration enhancer (CPE) combinations and an antimicrobial sufficiently increases antimicrobial flux such that therapeutic levels can traverse the tympanic membrane (TM) within 12 hours, in vitro. We compare excised chinchilla TMs treated with ciprofloxacin (fluoroquinolone antibiotic) alone and with different combinations of sodium lauryl sulfate, limonene, and bupivacaine, with respect to resultant changes in TM electrical resistance and trans-TM ciprofloxacin flux. We also investigate the interactions of CPEs and local anesthetics with respect to both permeability enhancement and changes in nerve block potency and efficacy. Finally, we evaluate our hydrogel formulations in an in vivo chinchilla model of OM, and demonstrate early success in their ability to safely and effectively eradicate middle ear bacteria.by Emmanuel J. Simons.Ph.D

    Characterization of the microbiome associated with in situ earthen materials

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    Background The current increase in public awareness of environmental risks is giving rise to a growth of interest in the microbiological safety of buildings. In particular, microbial proliferation on construction materials can be responsible for the degradation of indoor air quality that can increase health-risk to occupants. Raw earth materials are still widely used throughout the world and, in some cases, are linked to heritage habitats, as in the southwest of France. Moreover, these building materials are currently the subject of renewed interest for ecological and economic reasons. However, the microbial status of earthen materials raises major concerns: could the microbiome associated with such natural materials cause disease in building occupants? Very few analyses have been performed on the microbial communities present on these supports. Characterizing the raw earth material microbiome is also important for a better evaluation and understanding of the susceptibility of such materials to microbial development. This study presents the distribution of in situ bacterial and fungal communities on different raw earth materials used in construction. Various buildings were sampled in France and the microbial communities present were characterized by amplicon high-throughput sequencing (bacterial 16S rRNA gene and fungal ITS1 region). Bacterial culture isolates were identified at the species level by MALDI-TOF mass spectrometry. Results The major fungal and bacterial genera identified were mainly associated with conventional outdoor and indoor environmental communities, and no specific harmful bacterial species were detected on earthen materials. However, contrary to expectations, few human-associated genera were detected in dwellings. We found lower microbial alpha-diversity in earthen material than is usually found in soil, suggesting a loss of diversity during the use of these materials in buildings. Interestingly enough, the main features influencing microbial communities were building history and room use, rather than material composition. Conclusions These results constitute a first in-depth analysis of microbial communities present on earthen materials in situ and may be considered as a first referential to investigate microbial communities on such materials according to environmental conditions and their potential health impact. The bacterial and fungal flora detected were similar to those found in conventional habitats and are thought to be mainly impacted by specific events in the building’s life, such as water damage

    Decreases in adolescent weekly alcohol use in Europe and North America: evidence from 28 countries from 2002 to 2010

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    Background: This study examined trends in adolescent weekly alcohol use between 2002 and 2010 in 28 European and North American countries. Methods: Analyses were based on data from 11-, 13- and 15-year-old adolescents who participated in the Health Behaviour in School-Aged Children (HBSC) study in 2002, 2006 and 2010. Results: Weekly alcohol use declined in 20 of 28 countries and in all geographic regions, from 12.1 to 6.1% in Anglo-Saxon countries, 11.4 to 7.8% in Western Europe, 9.3 to 4.1% in Northern Europe and 16.3 to 9.9% in Southern Europe. Even in Eastern Europe, where a stable trend was observed between 2002 and 2006, weekly alcohol use declined between 2006 and 2010 from 12.3 to 10.1%. The decline was evident in all gender and age subgroups. Conclusions: These consistent trends may be attributable to increased awareness of the harmful effects of alcohol for adolescent development and the implementation of associated prevention efforts, or changes in social norms and conditions. Although the declining trend was remarkably similar across countries, prevalence rates still differed considerably across countrie

    Galectin-4 and sulfatides in apical membrane trafficking in enterocyte-like cells

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    We have previously reported that 1-benzyl-2-acetamido-2-deoxy-α-d-galactopyranoside (GalNAcα-O-bn), an inhibitor of glycosylation, perturbed apical biosynthetic trafficking in polarized HT-29 cells suggesting an involvement of a lectin-based mechanism. Here, we have identified galectin-4 as one of the major components of detergent-resistant membranes (DRMs) isolated from HT-29 5M12 cells. Galectin-4 was also found in post-Golgi carrier vesicles. The functional role of galectin-4 in polarized trafficking in HT-29 5M12 cells was studied by using a retrovirus-mediated RNA interference. In galectin-4–depleted HT-29 5M12 cells apical membrane markers accumulated intracellularly. In contrast, basolateral membrane markers were not affected. Moreover, galectin-4 depletion altered the DRM association characteristics of apical proteins. Sulfatides with long chain-hydroxylated fatty acids, which were also enriched in DRMs, were identified as high-affinity ligands for galectin-4. Together, our data propose that interaction between galectin-4 and sulfatides plays a functional role in the clustering of lipid rafts for apical delivery

    The Maunakea Spectroscopic Explorer Book 2018

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    (Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is intended as a concise reference guide to all aspects of the scientific and technical design of MSE, for the international astronomy and engineering communities, and related agencies. The current version is a status report of MSE's science goals and their practical implementation, following the System Conceptual Design Review, held in January 2018. MSE is a planned 10-m class, wide-field, optical and near-infrared facility, designed to enable transformative science, while filling a critical missing gap in the emerging international network of large-scale astronomical facilities. MSE is completely dedicated to multi-object spectroscopy of samples of between thousands and millions of astrophysical objects. It will lead the world in this arena, due to its unique design capabilities: it will boast a large (11.25 m) aperture and wide (1.52 sq. degree) field of view; it will have the capabilities to observe at a wide range of spectral resolutions, from R2500 to R40,000, with massive multiplexing (4332 spectra per exposure, with all spectral resolutions available at all times), and an on-target observing efficiency of more than 80%. MSE will unveil the composition and dynamics of the faint Universe and is designed to excel at precision studies of faint astrophysical phenomena. It will also provide critical follow-up for multi-wavelength imaging surveys, such as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation Very Large Array.Comment: 5 chapters, 160 pages, 107 figure

    The impact of society on management control systems

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    © 2017 Elsevier Ltd The aim of this study is to investigate whether certain configurations of management controls dominate in certain societies (socio-cultural contexts) and whether the effectiveness of a given archetype of management control systems (MCSs) varies depending on the socio-cultural setting—the society—in which it operates. The study focuses on three socio-cultural groups and the corresponding institutional contexts (an Anglo-Saxon group, a Central European group, and a Northern European group) and three MCS archetypes (delegated bureaucratic control, delegated output control, and programmable output control). We use unique data from a cross-national, interview-based survey encompassing 610 strategic business units from nine countries (seven European countries plus Canada and Australia). The idea that firms tend to adapt MCSs to the socio-cultural context does not gain empirical support in this study. No significant differences in the distribution of MCSs between the three socio-cultural groups are noted. However, we do find that programmable output control has a more positive impact on effectiveness in Anglo-Saxon cultures, while delegated output control has a more positive impact on effectiveness in Northern Europe. Taken together these findings indicate that distinct differences between societies make a particular MCS design more appropriate in a given society, but where such differences are not dramatic (as in the present case), multiple MCS designs can be found in the same society

    Actin Polymerization Controls the Organization of WASH Domains at the Surface of Endosomes

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    Sorting of cargoes in endosomes occurs through their selective enrichment into sorting platforms, where transport intermediates are generated. The WASH complex, which directly binds to lipids, activates the Arp2/3 complex and hence actin polymerization onto such sorting platforms. Here, we analyzed the role of actin polymerization in the physiology of endosomal domains containing WASH using quantitative image analysis. Actin depolymerization is known to enlarge endosomes. Using a novel colocalization method that is insensitive to the heterogeneity of size and shape of endosomes, we further show that preventing the generation of branched actin networks induces endosomal accumulation of the WASH complex. Moreover, we found that actin depolymerization induces a dramatic decrease in the recovery of endosomal WASH after photobleaching. This result suggests a built-in turnover, where the actin network, i.e. the product of the WASH complex, contributes to the dynamic exchange of the WASH complex by promoting its detachment from endosomes. Our experiments also provide evidence for a role of actin polymerization in the lateral compartmentalization of endosomes: several WASH domains exist at the surface of enlarged endosomes, however, the WASH domains coalesce upon actin depolymerization or Arp2/3 depletion. Branched actin networks are thus involved in the regulation of the size of WASH domains. The potential role of this regulation in membrane scission are discussed
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