A Note on Derivation of Minimal set of Compatibility Classes for Covering

This paper briefly describes the concept of compatibility relation defined on a finite set  and thereby, that of maximal compatibility classes. For a given compatibility relation defined on , not all the maximal compatibles are needed to ensure covering  for . A technique to derive a minimal set of maximal compatibility classes which covers  is proposed and some results obtained. Keywords: Compatibility relation, Maximal compatibility classes, Minimal covering

An empirical survey of the perceived benefits of executing BIM and sustainability practices in the built environment

PurposeThe increasing urbanization of the built environment has bolstered the need to promote green Building Information Modeling (BIM) initiative in new construction projects and the rehabilitation of old premises. This study aims to explore and examine the key benefits of the implementation of BIM and sustainability practices in the built environment.Design/methodology/approachThe study gathered the worldwide perceptions of 220 survey participants from 21 countries which were analyzed using descriptive and inferential analytical methods. The identified individual benefits of green BIM were further categorized into their underlying clusters using factor analysis.FindingsThe key benefits are related to enhancing project efficiency and productivity, ensuring real-time sustainable design and multi-design alternatives, facilitating the selection of sustainable materials and components, together with reducing material wastage and project’s environmental impact, among others. The study analyzed and compared the perceptions of the diverse groups of the respondents as well.Practical implicationsEffective blueprints and insightful recommendations for enhancing the various stakeholders’ capacities to implement green BIM in their construction projects were put forward to achieve the aim of sustainable smart urbanization.Originality/valueThe study identified salient benefits of the adoption of BIM and sustainability practices. The proper integration of these concepts and the execution of the recommended useful strategies by construction stakeholders, policymakers and local authorities will enable the built environment to reap the gains of its implementation

Concomitant Impediments to the implementation of Smart Sustainable Practices in the Built Environment

The paper examines the major barriers to the application of smart tools to enhance the implementation of sustainability practices in the built environment. The study collated 38 types of impediments from a comprehensive desktop review of the literature, and the data collected were further subjected to expert review via the use of empirical questionnaire surveys. The perceptions of 220 professional respondents from 21 countries were collated via the surveys for statistical analysis and classification purposes. The study findings revealed the significant impediments as related to inadequate knowledge and skills, the current market structure and inherent resistance to change in the built environment, and organizational challenges, among others. A comparative analysis of the perceptions of the diverse groups of survey participants was conducted and discussed. The adoption of the survey findings is envisaged to help the built environment in minimizing the impact of these barriers and can serve as a policy instrument and useful guidelines for government agencies, stakeholders, and others towards ensuring BIM can be used to deliver the full potential of sustainability practices in the construction industry. The study has provided effective practical strategies and recommendations for enhancing the implementation of smart sustainability practices in the built environment

Perceived benefits of and barriers to Building Information Modelling (BIM) implementation in construction: The case of Hong Kong

BIM has experienced an increasing appeal in its adoption and implementation in the built environment worldwide in recent years. The current research study aims to identify and assess the perceived benefits of and barriers to BIM implementation in the Hong Kong construction industry. The study adopted a quantitative research design using a structured empirical questionnaire survey. Also, a comparative analysis of the perceptions of the respondents’ groupings was conducted. The major barriers to BIM adoption are related to the inherent resistance to change by construction stakeholders, inadequate organizational support and structure to execute BIM, and lack of BIM industry standards in Hong Kong. Meanwhile, the key benefits include better cost estimation and control, efficient construction planning and management, and improvement in design and project quality. Practical and insightful recommendations were suggested for policymakers, local authorities, construction firms, and other key stakeholders to increase the uptake of BIM in construction projects as well as to aid them in the quest for full adoption of BIM in the built environment. The practical implications of the research findings were also presented and discussed

Long Range Hops and the Pair Annihilation Reaction A+A->0: Renormalization Group and Simulation

A simple example of a non-equilibrium system for which fluctuations are important is a system of particles which diffuse and may annihilate in pairs on contact. The renormalization group can be used to calculate the time dependence of the density of particles, and provides both an exact value for the exponent governing the decay of particles and an epsilon-expansion for the amplitude of this power law. When the diffusion is anomalous, as when the particles perform Levy flights, the critical dimension depends continuously on the control parameter for the Levy distribution. The epsilon-expansion can then become an expansion in a small parameter. We present a renormalization group calculation and compare these results with those of a simulation.Comment: As-published version; two significant errors fixed, two references adde

Global trends of hand and wrist trauma: A systematic analysis of fracture and digit amputation using the Global Burden of Disease 2017 Study

Background: As global rates of mortality decrease, rates of non-fatal injury have increased, particularly in low Socio-demographic Index (SDI) nations. We hypothesised this global pattern of non-fatal injury would be demonstrated in regard to bony hand and wrist trauma over the 27-year study period. Methods: The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 was used to estimate prevalence, age-standardised incidence and years lived with disability for hand trauma in 195 countries from 1990 to 2017. Individual injuries included hand and wrist fractures, thumb amputations and non-thumb digit amputations. Results: The global incidence of hand trauma has only modestly decreased since 1990. In 2017, t

Physical activity attenuates the influence of FTO variants on obesity risk: A meta-analysis of 218,166 adults and 19,268 children

Background: The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n = 218,166) and nine studies of children and adolescents (n = 19,268). Methods and Findings: All studies identified to have data on the FTO rs9939609 variant (or any proxy [r2>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTO×PA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A-) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20-1.26), but PA attenuated this effect (pinteraction= 0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio = 1.22/allele, 95% CI 1.19-1.25) than in the inactive group (odds ratio = 1.30/allele, 95% CI 1.24-1.36). No such interaction was found in children and adolescents. Concl

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Wet-cold preservation of West African yam (Dioscorea spp.) pollen

Hermetic cold storage without previous drying (wet–cold storage) was experimented for the preservation of yam pollen grains. Pollens collected from white yam D. rotundata and a wild relative, D. praehensilis, were stored at -80, -20, 5, and 150C in sealed packs for 2 years. Pollen samples were drawn for in vitro germination tests after 100 and 700 days, and hand pollination was conducted after 365 and 730 days in storage. Pollen germination responses were not significantly different among the two species. Though pollen maintained germination capacity at all the storage temperature regimes, there was a significant loss in the viability of pollen stored at 5 and 15 _C after 100 days of storage. After 700 days in storage, pollens stored at 5 and 150C had lost germination capacity while there were no significant differences in the germination of fresh pollen and pollen frozen at -80 and -200C. Hand pollination with pollen of D. rotundata frozen at -800C for 365 days gave 69.5% fruit set and 50% fruit set after 730 days in storage. From these results, the wet–freeze procedure appears promising to execute the establishment of pollen gene banks for yam breeding and for conservation of haploid gene pool of yams in base collections. A pollen storage protocol based on the procedure is recommended