Thermal comfort and energy performance of public rental housing under typical and near-extreme weather conditions in Hong Kong

© 2017 Elsevier B.V. Building performance evaluation is crucial for sustainable urban developments. In high-density cities, occupants suffer from poor living conditions due to building overheating, especially during increasingly frequent near-extreme summer conditions caused by climate change. To represent this situation, the summer reference year weather data was employed for building simulations using DesignBuilder. This study aims to evaluate the thermal comfort and energy consumption of four typical public rental housing (PRH) building types in Hong Kong. For free-running flats, results show generally higher air temperatures in the oldest PRH type (Slab) with a compact linear building form and the most sensitive response to outdoor temperature changes for another older PRH type (Trident) with a Y-shaped design, possibly owing to its high wall conductivity. Occupants in all building types experience a ???10% increase in the proportion of discomfort hours when compared to results for typical summer conditions, but overheating is the most severe in Slab type PRH. Following an initial assessment of the cooling energy usage, a simple sensitivity test was conducted to explore the potential energy savings by various passive design strategies, including shading and reducing the exposed cooled space. A cross-shaped building form also appears to be more energy efficient. These findings, complemented by further parametric analyses, may prove useful when designing buildings for climate change

A comparative study on the indoor thermal comfort and energy consumption of typical public rental housing types under near-extreme summer conditions in Hong Kong

© 2017 The Authors. Published by Elsevier Ltd. Residents of the dense urban environment in Hong Kong suffer from poor living conditions due to building overheating, especially during near-extreme summer conditions. In this study, the thermal comfort and energy performance of typical public rental housing (PRH) building types were simulated using DesignBuilder. Results show that the oldest Slab type PRH, which has a compact building form, has the highest indoor air temperature, yet the lowest cooling energy demand. On the other hand, the Trident type PRH, with the largest external wall U-value, performs the worst overall and is the most responsive to outdoor temperature changes

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

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

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

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to &lt;90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], &gt;300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of &lt;15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P&lt;0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P&lt;0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

Building porosity for better urban ventilation in high-density cities - A computational parametric study

10.1016/j.buildenv.2011.10.023BUILDING AND ENVIRONMENT50176-18

Policies and technicalities providing natural ventilation to domestic spaces for high-density tropical living in Hong Kong

10.1080/00038628.2011.641716ARCHITECTURAL SCIENCE REVIEW55161-7

Post-earthquake housing recovery with traditional construction: A preliminary review

Post-disaster reconstruction requires not only an immediate response but also long-term consideration of the recovery of local livelihoods, sustainability of technology transfer, and respect for sociocultural norms. A top-down approach for post-disaster reconstruction, usually relying on external resources and standardized prototypes, might strongly hinder the recovery process. To enhance community resilience, the use of traditional knowledge in post-disaster reconstruction is highlighted in the Sendai Framework. This study specifically focuses on traditional construction. A systematic literature review is conducted on post-earthquake housing recovery with traditional construction, and a hierarchical analysis framework helps categorize the review results at strategic, managerial, and operational levels. Drawn from the review, a classification of traditional construction systems is proposed, corresponding to their varied seismic performance. The results indicate the possibility of strengthening traditional construction with seismic engineering and its successful implementation into reconstruction. Specifically, it includes timber-reinforced masonry, wattle and daub, timber frame construction, reinforced rammed earth, and reinforced adobe. However, we also find that the sustainable practice of traditional construction remains problematic, and the replication of participatory reconstruction is difficult. This preliminary review serves to bridge the discipline of vernacular architecture and disaster management and establish a solid common ground for further argumentation

Large-eddy simulations of ventilation for thermal comfort - A parametric study of generic urban configurations with perpendicular approaching winds

10.1016/j.uclim.2017.04.007URBAN CLIMATE20202-22