26 research outputs found

    Using a new programme (THERCOM) to predict thermal comfort as a base to design energy efficient buildings

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    A strong relationship relates the thermal comfort and the consumption of energy, especially in the hot arid climate where the installation of HVAC systems is unavoidable. In fact, it has been reported that the HVAC systems are responsible for consuming huge amounts of the total energy used by the buildings that can globally reach up to 40% of the total primary energy requirement. The future estimations indicate that the energy consumption is likely to continue growing in the developed economies to exceed that of the developed countries in 2020. Under these situations, it seems that the shift towards more energy efficient buildings is not an option. Because part of any successful environmental design is to understand the potentials of the site, the proposed programme (THERCOM) assists in weighing the indoor and outdoor thermal comfort in different climates in order to provide better understanding of the site environment as well as testing the thermal comfort chances of the initial concepts

    Investigating the behaviour of ASHRAE, Bedford, and Nicol thermal scales when translated into the Arabic language

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    With the global spread of thermal comfort studies, thermal scales are translated into different languages to adapt local context in which the studies are applied. However, translating thermal comfort studies does not maintain the scales' behaviour associated with the original English versions. Behaviour differences include irregular categories' width, asymmetry, and deviation of the middle category centre from the centre of the thermal continuum. These differences have a negative influence on the results of thermal comfort studies and their accuracy. Applying the successive categories method, this paper explores the change in ASHRAE, Bedford, and Nicol scales' behaviour when translated into the Arabic language. The translated scales were integrated into questionnaires distributed among female high school students in Muscat, the capital city of Oman, as part of a larger survey that lasted for a whole year. The findings revealed the deviation of the translated scales from the original assumptions of the English versions. This included categories' irregular widths and asymmetry in addition to the deviation of the centre of the middle categories from the centre of the thermal continuum. Besides, it was found that both ASHRAE and Bedford scales covered different ranges on the thermal continuum, which questions their assumed equivalence. Based on these findings, the accuracy of the thermal comfort analysis is negatively affected. Considering the sensitivity of scales' behaviour to the used phrases, further explorations implementing the terms examined in this study are recommended. Abstract With the global spread of thermal comfort studies, thermal scales are translated into different languages to adapt local context in which the studies are applied. However, translating thermal comfort studies does not maintain the scales' behaviour associated with the original English versions. Behaviour differences include irregular categories' width, asymmetry, and deviation of the middle category centre from the centre of the thermal continuum. These differences have a negative influence on the results of thermal comfort studies and their accuracy. Applying the successive categories method, this paper explores the change in ASHRAE, Bedford, and Nicol scales' behaviour when translated into the Arabic language. The translated scales were integrated into questionnaires distributed among female high school students in Muscat, the capital city of Oman, as part of a larger survey that lasted for a whole year. The findings revealed the deviation of the translated scales from the original assumptions of the English versions. This included categories' irregular widths and asymmetry in addition to the deviation of the centre of the middle categories from the centre of the thermal continuum. Besides, it was found that both ASHRAE and Bedford scales covered different ranges on the thermal continuum, which questions their assumed equivalence. Based on these findings, the accuracy of the thermal comfort analysis is negatively affected. Considering the sensitivity of scales' behaviour to the used phrases, further explorations implementing the terms examined in this study are recommended

    Using a New Programme to Predict Thermal Comfort as a Base to Design Energy Efficient Buildings

    Get PDF
    A strong relationship relates the thermal comfort and the consumption of energy, especially in the hot arid climate where the installation of HVAC systems is unavoidable. In fact, it has been reported that the HVAC systems are responsible for consuming huge amounts of the total energy used by the buildings that can globally reach up to 40% of the total primary energy requirement. The future estimations indicate that the energy consumption is likely to continue growing in the developed economies to exceed that of the developed countries in 2020. Under these situations, it seems that the shift towards more energy efficient buildings is not an option. Because part of any successful environmental design is to understand the potentials of the site, the proposed programme (THERCOM) assists in weighing the indoor and outdoor thermal comfort in different climates in order to provide better understanding of the site environment as well as testing the thermal comfort chances of the initial concepts

    Evaluating assumptions of scales for subjective assessment of thermal environments – Do laypersons perceive them the way, we researchers believe?

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    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

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    Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world. Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231. Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001). Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication

    Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

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    Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

    Effects of covid-induced lockdown on inhabitants’ perception of indoor air quality in naturally ventilated homes

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    The intensified indoor living during the spring 2020 lockdown, with enhanced user awareness of the prevailing conditions in their homes, constituted a natural stress test for the housing design in place today. Surveys conducted during this period have yielded lessons for designing better intervention strategies for the residential sector, taking into account the systematic morphological and economic limitations of the buildings concerned. These considerations should inform the development of policies and strategies for improving environmental quality compatible with lower residential energy consumption and higher quality of life. This study explores the effect of occupant behaviour on home ventilation and the perception of the impact of indoor air quality on user health before and during lockdown. The method deployed consisted in monitoring environmental variables and conducting user surveys before and after restrictions came into force. The findings showed that prior to lockdown, occupants were unaware of or paid little heed to changes in indoor air quality, failed to perceive stuffiness, and, as a rule, reported symptoms or discomfort only at night during the summer months. During lockdown, however, users came to attach greater importance to air quality, and a greater sensitivity to odours and a heightened awareness of CO2 concentration prompted them to ventilate their homes more frequently. In the spring of 2020, occupants also indicated a wider spectrum of indisposition, in particular in connection with sleep patterns

    Travelers&rsquo; Perceptions on Significance of Travel Time Saving Attributes in Travel Behavior: A Case Study in Oman

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    As everyone spends much time traveling, engaged in leisure or work activities, travel time represents one of the largest costs to transportation. The main objective of the study is to investigate travelers&rsquo; perceptions related to value of travel time saving with the help of a questionnaire survey. The survey was conducted online with the help of Google forms. The required data were collected through a self-reported questionnaire that consisted of five parts. A total of 312 useable sample responses were collected. The collected data were analyzed using conventional and statistical methods. In conventional methods, frequency distribution was carried out, and bar and pie charts were prepared. In the statistical methods, the exploratory factor analysis method (EFA) was conducted to extract useful factors affecting the travelers&rsquo; perceptions about travel time saving attitude. The survey results showed that more than 73% of people use a car for transport, which implies that most of them do not like to wait for public transport modes. It means that their travel attitudes are more inclined towards private transport seeking travel time saving. Most people do not like to share space with others while traveling, amounting to 44% of respondents using private cars alone, and placing high importance on flexibility, reliability, and time and cost saving in traveling, which implies that they are more likely to travel alone to save travel time. In addition, most of the respondents use short routes; this propensity is positively related to time and cost saving factors. Similarly, the time and cost savings and car-oriented attitudes are positively associated with the choice of a short route to save travel time. They also believe that the service quality level of transportation facilities affects the travel time saving and its value. This study proposes to improve travel time and cost in Oman
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