Peer-to-peer mobility innovations: their adoption, use, and associated emissions impacts

The private ownership and use of cars has negative environmental, social, and economic impacts. Peer-to-peer (P2P) mobility innovations challenge the relationship between private ownership and use of cars and could contribute to a more sustainable mobility system. The research conducted for this PhD explored the adoption and diffusion of P2P mobility innovations and the potential impacts on CO₂ emissions in the UK. P2P ride sharing and P2P car sharing were used as two case study P2P mobility innovations. First, adopter characteristics and the ways in which adopters perceive the attributes of P2P mobility innovations were explored through a survey of 600 adopters and non-adopters. Second, seven in-depth focus groups were conducted with each of the adopter groups identified in the first research chapter. Third, the current emissions impacts of P2P mobility innovations were quantified for each identified type of adopter, and the potential emission reductions under different future scenarios were explored. Results from the surveys revealed that there are heterogenous groups of adopters of each innovation. These groups differ from each other and from the mainstream population in their sociodemographic and personality characteristics, how they use P2P mobility innovations, and how they perceive the attributes of P2P mobility innovations. Identifying these distinct groups establishes differences in the market potential for P2P mobility innovations. Results from the focus groups revealed that each group differed in how they regard and place importance on the mechanisms of building trust (peer-reputation and reviews, inter-personal relationships, and validation checks), and the targets of trust (trust in peers, trust in the platform, and trust in the product). Users of P2P car sharing placed more importance on trust in the platform, whereas users of P2P ride sharing placed more importance on trust in other people. Trust is vital to the diffusion of P2P mobility innovations and understanding how the identified adopter groups perceive and value trust differently has implications for diffusion strategies. Results from the emissions quantifications revealed that for some adopter groups (commuters using P2P ride sharing), the largest emissions reductions come from using P2P mobility innovations instead of private car use, whereas for other groups (peer-users of P2P car sharing) the largest emissions reductions arise due to forgone vehicle purchases. Results from the future scenario exploration revealed potential emissions reductions of four to seven times larger than current estimates in a high-trust and high-institutional-support future. The scenario analysis contributes to knowledge about how to maximise the largest potential emissions reductions for different adopter groups. This thesis contributes novel empirical insights into the adopters of P2P mobility innovations. The diffusion potential of P2P mobility innovations is examined and the importance of understanding the diversity of adopters, and their unique contexts, motivations, and perceptions is illustrated. The value of these insights to maximise the potential emissions reductions of P2P mobility are highlighted, and recommendations to platforms and for policy are provided to this end

Chronic Periodontitis Genome-wide Association Study in the Hispanic Community Health Study / Study of Latinos

Chronic periodontitis (CP) has a genetic component, particularly its severe forms. Evidence from genome-wide association studies (GWASs) has highlighted several potential novel loci. Here, the authors report the first GWAS of CP among a large community-based sample of Hispanics/Latinos. The authors interrogated a quantitative trait of CP (mean interproximal clinical attachment level determined by full-mouth periodontal examinations) among 10,935 adult participants (mean age: 45 y, range: 18 to 76 y) from the Hispanic Community Health Study / Study of Latinos. Genotyping was done with a custom Illumina Omni2.5M array, and imputation to approximately 20 million single-nucleotide polymorphisms was based on the 1000 Genomes Project phase 1 reference panel. Analyses were based on linear mixed models adjusting for sex, age, study design features, ancestry, and kinship and employed a conventional P < 5 × 10−8 statistical significance threshold. The authors identified a genome-wide significant association signal in the 1q42.2 locus (TSNAX-DISC1 noncoding RNA, lead single-nucleotide polymorphism: rs149133391, minor allele [C] frequency = 0.01, P = 7.9 × 10−9) and 4 more loci with suggestive evidence of association (P < 5 × 10−6): 1q22 (rs13373934), 5p15.33 (rs186066047), 6p22.3 (rs10456847), and 11p15.1 (rs75715012). We tested these loci for replication in independent samples of European-American (n = 4,402) and African-American (n = 908) participants of the Atherosclerosis Risk in Communities study. There was no replication among the European Americans; however, the TSNAX-DISC1 locus replicated in the African-American sample (rs149133391, minor allele frequency = 0.02, P = 9.1 × 10−3), while the 1q22 locus was directionally concordant and nominally significant (rs13373934, P = 4.0 × 10−2). This discovery GWAS of interproximal clinical attachment level—a measure of lifetime periodontal tissue destruction—was conducted in a large, community-based sample of Hispanic/Latinos. It identified a genome-wide significant locus that was independently replicated in an African-American population. Identifying this genetic marker offers direction for interrogation in subsequent genomic and experimental studies of CP

Potential climate benefits of digital consumer innovations

Digitalization has opened up a wealth of new goods and services with strong consumer appeal alongside potential emission-reduction benefits. Examples range from shared, on-demand electric mobility and peer-to-peer trading of electricity, food, and cars to grid-responsive smart appliances and heating systems. In this review, we identify an illustrative sample of 33 digital consumer innovations that challenge emission-intensive mainstream consumption practices in mobility, food, homes, and energy domains. Across these domains, digital innovations offer consumers a range of potentially appealing attributes from control, choice, and convenience to independence, interconnectedness, and integration with systems. We then compile quantitative estimates of change in activity, energy, or emissions as a result of consumers adopting digital innovations. This novel synthesis of the evidence base shows clear but variable potential emission-reduction benefits of digital consumer innovations. However, a small number of studies show emission increases from specific innovations as a result of induced demand or substitution effects that need careful management by public policy. We also consider how concurrent adoption of digital consumer innovations across mobility, food, homes, and energy domains can cause broader disruptive impacts on regulatory frameworks, norms, and infrastructures. We conclude by arguing for the importance of public policy in steering the digitalization of consumer goods and services toward low-carbon outcomes

Factors influencing epiphytic moss and lichen distribution within Killarney National Park

The niches of epiphytes are widely studied and have been shown to be complex involving interspecific competition, succession and predation. This study is unique in that it applies the niche concept to moss and lichen distributions within Killarney National Park, Kerry, Ireland. We studied 75 trees between three pristine ancient woodlands and measured a range of physical and biological factors to ascertain influences on epiphyte cover. The species of tree was found as the principal determinant in community structure as it bioengineers conditions such as light, temperature and humidity that the epiphytes are reliant upon. Furthermore, the bark character and trunk circumference were important. Zonation of the epiphytes was apparent with both aspect and height on the trunk. Typically, moss dominated over lichen within a niche that was relatively sheltered. Lichen tolerated drier and lighter niches often being further up the trunk on sun facing aspects. Ultimately, there was succession up the tree mediated through competition. This study highlights the complexity and interrelatedness between biotic and abiotic factors in a relatively unstudied geographical and biological area. Understanding agents behind a population's distribution enables manipulation for conservation or sustainable exploitation

Are low carbon innovations appealing? A typology of functional, symbolic, private and public attributes

Attributes are central to understanding the consumer appeal of low carbon innovations. In this paper we provide a comprehensive understanding of the wide ranging attributes of low carbon innovations. We use a two-by-two dimensional typology which identifies four discrete domains of attribute: private functional, public functional, private symbolic, and public symbolic. Using structured elicitation with over 65 people we examine perceived attributes of 12 consumer innovations in mobility, food, homes and energy. We find that low carbon innovations are relatively unappealing against the private functional and symbolic attributes valued by potential mainstream consumers. This includes features such as money saving, time saving, ease of access, ease of use, trust, and private identity. They are, however, highly appealing against many public functional and symbolic attributes including a range of social and environmental benefits. Food innovations in particular have high social appeal where they support local businesses, protect and build communities around food and build community spirit. Home innovations such as smart appliances and smart lighting are highly appealing because they are novel yet also fit within current social norms. Low carbon innovations based on the sharing economy model offer unique sources of added value related to the creation of social institutions and localised networks. It is important that low carbon innovations are positioned within the marketplace so as to emphasise unique sources of added value within the public domain rather than compete directly with established incumbents whose business models are largely built on volume, scale and costs

Genome-wide association study of dental caries in the Hispanic Communities Health Study/Study of Latinos (HCHS/SOL)

Dental caries is the most common chronic disease worldwide, and exhibits profound disparities in the USA with racial and ethnic minorities experiencing disproportionate disease burden. Though heritable, the specific genes influencing risk of dental caries remain largely unknown. Therefore, we performed genome-wide association scans (GWASs) for dental caries in a population-based cohort of 12 000 Hispanic/Latino participants aged 18–74 years from the HCHS/SOL. Intra-oral examinations were used to generate two common indices of dental caries experience which were tested for association with 27.7 M genotyped or imputed single-nucleotide polymorphisms separately in the six ancestry groups. A mixed-models approach was used, which adjusted for age, sex, recruitment site, five principal components of ancestry and additional features of the sampling design. Meta-analyses were used to combine GWAS results across ancestry groups. Heritability estimates ranged from 20–53% in the six ancestry groups. The most significant association observed via meta-analysis for both phenotypes was in the region of the NAMPT gene (rs190395159; P-value = 6 × 10−10), which is involved in many biological processes including periodontal healing. Another significant association was observed for rs72626594 (P-value = 3 × 10−8) downstream of BMP7, a tooth development gene. Other associations were observed in genes lacking known or plausible roles in dental caries. In conclusion, this was the largest GWAS of dental caries, to date and was the first to target Hispanic/Latino populations. Understanding the factors influencing dental caries susceptibility may lead to improvements in prediction, prevention and disease management, which may ultimately reduce the disparities in oral health across racial, ethnic and socioeconomic strata

A Powerful Statistical Framework for Generalization Testing in GWAS, with Application to the HCHS/SOL

In GWAS, “generalization” is the replication of genotype-phenotype association in a population with different ancestry than the population in which it was first identified. The standard for reporting findings from a GWAS requires a two-stage design, in which discovered associations are replicated in an independent follow-up study. Current practices for declaring generalizations rely on testing associations while controlling the Family Wise Error Rate (FWER) in the discovery study, then separately controlling error measures in the follow-up study. While this approach limits false generalizations, we show that it does not guarantee control over the FWER or False Discovery Rate (FDR) of the generalization null hypotheses. In addition, it fails to leverage the two-stage design to increase power for detecting generalized associations. We develop a formal statistical framework for quantifying the evidence of generalization that accounts for the (in)consistency between the directions of associations in the discovery and follow-up studies. We develop the directional generalization FWER (FWERg) and FDR (FDRg) controlling r-values, which are used to declare associations as generalized. This framework extends to generalization testing when applied to a published list of SNP-trait associations. We show that our framework accommodates various SNP selection rules for generalization testing based on p-values in the discovery study, and still control FWERg or FDRg. A key finding is that it is often beneficial to use a more lenient p-value threshold then the genome-wide significance threshold. For instance, in a GWAS of Total Cholesterol (TC) in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), when testing all SNPs with p-values\u3c 5 × 10−8 (15 genomic regions) for generalization in a large GWAS of whites, we generalized SNPs from 15 regions. But when testing all SNPs with p-values\u3c 6.6×10−5 (89 regions), we generalized SNPs from 27 regions

GWAS Identifies New Loci for Painful Temporomandibular Disorder: Hispanic Community Health Study/Study of Latinos

Temporomandibular disorder (TMD) is a musculoskeletal condition characterized by pain and reduced function in the temporomandibular joint and/or associated masticatory musculature. Prevalence in the United States is 5% and twice as high among women as men. We conducted a discovery genome-wide association study (GWAS) of TMD in 10,153 participants (769 cases, 9,384 controls) of the US Hispanic Community Health Study/Study of Latinos (HCHS/SOL). The most promising single-nucleotide polymorphisms (SNPs) were tested in meta-analysis of 4 independent cohorts. One replication cohort was from the United States, and the others were from Germany, Finland, and Brazil, totaling 1,911 TMD cases and 6,903 controls. A locus near the sarcoglycan alpha (SGCA), rs4794106, was suggestive in the discovery analysis (P = 2.6 × 106) and replicated (i.e., 1-tailed P = 0.016) in the Brazilian cohort. In the discovery cohort, sex-stratified analysis identified 2 additional genome-wide significant loci in females. One lying upstream of the relaxin/insulin-like family peptide receptor 2 (RXP2) (chromosome 13, rs60249166, odds ratio [OR] = 0.65, P = 3.6 × 10−8) was replicated among females in the meta-analysis (1-tailed P = 0.052). The other (chromosome 17, rs1531554, OR = 0.68, P = 2.9 × 10−8) was replicated among females (1-tailed P = 0.002), as well as replicated in meta-analysis of both sexes (1-tailed P = 0.021). A novel locus at genome-wide level of significance (rs73460075, OR = 0.56, P = 3.8 × 10−8) in the intron of the dystrophin gene DMD (X chromosome), and a suggestive locus on chromosome 7 (rs73271865, P = 2.9 × 10−7) upstream of the Sp4 Transcription Factor (SP4) gene were identified in the discovery cohort, but neither of these was replicated. The SGCA gene encodes SGCA, which is involved in the cellular structure of muscle fibers and, along with DMD, forms part of the dystrophin-glycoprotein complex. Functional annotation suggested that several of these variants reside in loci that regulate processes relevant to TMD pathobiologic processes

Large-scale pharmacogenomic study of sulfonylureas and the QT, JT and QRS intervals: CHARGE Pharmacogenomics Working Group

Sulfonylureas, a commonly used class of medication used to treat type 2 diabetes, have been associated with an increased risk of cardiovascular disease. Their effects on QT interval duration and related electrocardiographic phenotypes are potential mechanisms for this adverse effect. In 11 ethnically diverse cohorts that included 71 857 European, African-American and Hispanic/Latino ancestry individuals with repeated measures of medication use and electrocardiogram (ECG) measurements, we conducted a pharmacogenomic genome-wide association study of sulfonylurea use and three ECG phenotypes: QT, JT and QRS intervals. In ancestry-specific meta-analyses, eight novel pharmacogenomic loci met the threshold for genome-wide significance (P&lt;5 × 10−8), and a pharmacokinetic variant in CYP2C9 (rs1057910) that has been associated with sulfonylurea-related treatment effects and other adverse drug reactions in previous studies was replicated. Additional research is needed to replicate the novel findings and to understand their biological basis

A powerful statistical framework for generalization testing in GWAS, with application to the HCHS/SOL

In genome-wide association studies (GWAS), “generalization” is the replication of genotype-phenotype association in a population with different ancestry than the population in which it was first identified. Current practices for declaring generalizations rely on testing associations while controlling the family-wise error rate (FWER) in the discovery study, then separately controlling error measures in the follow-up study. This approach does not guarantee control over the FWER or false discovery rate (FDR) of the generalization null hypotheses. It also fails to leverage the two-stage design to increase power for detecting generalized associations. We provide a formal statistical framework for quantifying the evidence of generalization that accounts for the (in)consistency between the directions of associations in the discovery and follow-up studies. We develop the directional generalization FWER (FWERg) and FDR (FDRg) controlling r-values, which are used to declare associations as generalized. This framework extends to generalization testing when applied to a published list of Single Nucleotide Polymorphism-(SNP)-trait associations. Our methods control FWERg or FDRg under various SNP selection rules based on P-values in the discovery study. We find that it is often beneficial to use a more lenient P-value threshold than the genome-wide significance threshold. In a GWAS of total cholesterol in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), when testing all SNPs with P-values &lt; 5 × 10-8 (15 genomic regions) for generalization in a large GWAS of whites, we generalized SNPs from 15 regions. But when testing all SNPs with P-values &lt; 6.6 × 10-5 (89 regions), we generalized SNPs from 27 regions