Contributions of various transmission paths to speech privacy of open ceiling meeting rooms in open-plan offices

© 2016 Elsevier Ltd. Installing open ceiling meeting rooms inside a large open-plan office provides a solution to increase speech privacy and to reduce speech disturbance in the office. The open ceiling meeting rooms have advantages of low cost construction and flexibility, but have lower speech privacy than that of enclosed rooms due to the open ceiling. Existing research shows that many factors should be taken into account to achieve good speech privacy in open-plan offices and improving only one of these factors may result in little improvement, so it is important to distinguish contributions of different acoustic transmission paths of open ceiling meeting rooms in open-plan offices. This paper proposes an impulse response separation method to quantify contributions of various acoustic paths of open ceiling rooms on speech privacy in open-plan offices. The method is verified with simulations based on the Odeon software and the experiments carried out in 3 different types of rooms. Finally, the proposed method is applied to the Fabpod, a semi enclosed meeting room located in a large indoor office at the Design Research Institute of the RMIT University, to obtain the contributions of different acoustic transmission paths to its speech privacy. The method proposed in this paper and the knowledge obtained are useful for architects to improve the acoustic performance of the next generation Fabpods which are now under design at RMIT University

A low-cost vision based navigation system for small size unmanned aerial vehicle applications

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Active sound radiation control with secondary sources at the edge of the opening

© 2016 Elsevier Ltd Planar virtual sound barriers with secondary sources over the entire opening have been demonstrated an effective way to achieve global control of sound transmission through the opening, but loudspeakers in the middle of the opening affect ventilation, lighting and normal access through it. To avoid the problem, this technical note proposes to implement secondary sources at the edge of a cavity opening and investigates the active sound reduction performance of the system numerically and experimentally. Unlike secondary sources over the entire opening which can achieve sound reduction at any frequency as long as there are sufficient of them, there exists an upper bound of effective frequency for global control when secondary sources are at the edge of the opening; however, local control is always achievable. Preliminary experiments were conducted on an open wooden box and a semi-closed meeting room to support the conclusions

Factors Associated with High Prevalence of Intestinal Protozoan Infections among Patients in Sana'a City, Yemen

Intestinal protozoan diseases in Yemen are a significant health problem with prevalence ranging from 18% to 27%. The present study is a cross-sectional study aimed at determining the factors associated with the high prevalence of intestinal protozoan infections among patients seeking health care in Sana'a City, the capital of Yemen. (0.4%). Multivariate analysis using forward stepwise logistic regression based on intestinal protozoan infections showed that contact with animals (OR = 1.748, 95% CI = 1.168–2.617) and taking bath less than twice a week (OR = 1.820, 95% CI = 1.192–2.779) were significant risk factors of protozoan infections. infections being most common. Statistical analysis indicated that low personal hygiene and contact with animals were important predictors for intestinal protozoan infections. As highlighted in this study, in order to effectively reduce these infections, a multi-sectoral effort is needed. Preventive measures should include good hygienic practices, good animal husbandry practices, heightened provision of educational health programs, health services in all governorates including rural areas. Furthermore, it is also essential to find radical solutions to the recent water crises in Yemen

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Inhibition of protein ubiquitination by paraquat and 1-methyl-4-phenylpyridinium impairs ubiquitin-dependent protein degradation pathways

Intracytoplasmic inclusions of protein aggregates in dopaminergic cells (Lewy bodies) are the pathological hallmark of Parkinson’s disease (PD). Ubiquitin (Ub), alpha [α]-synuclein, p62/sequestosome 1 and oxidized proteins are major components of Lewy bodies. However, the mechanisms involved in the impairment of misfolded/oxidized protein degradation pathways in PD are still unclear. PD is linked to mitochondrial dysfunction and environmental pesticide exposure. In this work, we evaluated the effect of the pesticide paraquat (PQ) and the mitochondrial toxin 1-methyl-4-phenylpyridinium (MPP+) on Ub-dependent protein degradation pathways. No increase in the accumulation of Ub-bound proteins or aggregates was observed in dopaminergic cells (SK-N-SH) treated with PQ or MPP+, or in mice chronically exposed to PQ. PQ decreased Ub protein content, but not its mRNA transcription. Protein synthesis inhibition with cycloheximide depleted Ub levels and potentiated PQ–induced cell death. Inhibition of proteasomal activity by PQ was found to be a late event in cell death progression, and had no effect on either the toxicity of MPP+ or PQ, or the accumulation of oxidized sulfenylated, sulfonylated (DJ-1/PARK7 and peroxiredoxins) and carbonylated proteins induced by PQ. PQ- and MPP+-induced Ub protein depletion prompted the dimerization/inactivation of the Ub-binding protein p62 that regulates the clearance of ubiquitinated proteins by autophagic. We confirmed that PQ and MPP+ impaired autophagy flux, and that the blockage of autophagy by the overexpression of a dominant-negative form of the autophagy protein 5 (dnAtg5) stimulated their toxicity, but there was no additional effect upon inhibition of the proteasome. PQ induced an increase in the accumulation of α-synuclein in dopaminergic cells and membrane associated foci in yeast cells. Our results demonstrate that inhibition of protein ubiquitination by PQ and MPP+ is involved in the dysfunction of Ub-dependent protein degradation pathways

In memory detection of Windows API call hooking technique

API call hooking is a technique that malware researchers use to mine malware's API calls. These API calls is used to represent malware's behavior, for use in malware analysis, classification or detection of samples. In this paper, analysis of current Windows API call hooking techniques is presented where surprisingly, it was found that detection of each technique can be done trivially in memory. This could lead to malware being able to sense the presence of API call hooking techniques and modifying their behavior during runtime. Suggestions for a better API call hooking technique are presented towards the end of the paper

Effect of aerogel incorporation in PCM-containing thermal liner of firefighting garment

Phase change material (PCM) in firefighting garment enhances protection and comfort. Wearing a protective clothing containing PCM, while fighting the fire, is a direct risk to the wearer as most PCMs used are flammable. This article reports a solution by using aerogel. Thermal liner fabric was treated with PCM and/or aerogel and then their thermal properties were analyzed. It has been found that the mean ignition time of PCM-containing thermal liner is around 3.3 s in current case while this value significantly increased to 5.5 s when the combination of aerogel and PCM was used. Moreover, the weight of the liner fabric with aerogel decreased in comparison to PCM-containing liner. Aerogel also slowed down the spreading of flame in PCM-containing fabric. Aerogel-coated liner showed superior heat resistance and the combination of aerogel with PCM increased the thermal resistance of PCM-containing liner

Effect of aerogel incorporation in PCM-containing thermal liner of firefighting garment

Phase change material (PCM) in firefighting garment enhances protection and comfort. Wearing a protective clothing containing PCM, while fighting the fire, is a direct risk to the wearer as most PCMs used are flammable. This article reports a solution by using aerogel. Thermal liner fabric was treated with PCM and/or aerogel and then their thermal properties were analyzed. It has been found that the mean ignition time of PCM-containing thermal liner is around 3.3 s in current case while this value significantly increased to 5.5 s when the combination of aerogel and PCM was used. Moreover, the weight of the liner fabric with aerogel decreased in comparison to PCM-containing liner. Aerogel also slowed down the spreading of flame in PCM-containing fabric. Aerogel-coated liner showed superior heat resistance and the combination of aerogel with PCM increased the thermal resistance of PCM-containing liner

Virtual ceiling systems for open ceiling meeting rooms in open plan offices

Large open plan offices have advantages of low cost construction and flexibility, but they sometimes lack speech privacy and generate sound disturbance when people are talking. Installing small closed meeting rooms inside open plan offices is a good solution to the problem, but the ceiling increases the cost of the meeting rooms due to the requirements of fire safety regulations and extra ventilation and lighting systems. Having the ceiling open or removing the ceiling of the meeting rooms is an option; however, the challenge is the low speech privacy caused by sound wave propagation through the opening. This paper shows an example to analyse relative contributions of different acoustic paths to speech privacy from the opening of an open ceiling meeting room in an open plan office based on the impulse response separation method, and demonstrates a virtual ceiling system in a large open plan office. Preliminary experimental results show the feasibility of the virtual ceiling system and also its limitations. Finally, future research directions for the virtual ceiling systems are discussed