Russell Thomson

Global conservation outcomes depend on marine protected areas with five key features

In line with global targets agreed under the Convention on Biological Diversity, the number of marine protected areas (MPAs) is increasing rapidly, yet socio-economic benefits generated by MPAs remain difficult to predict and under debate. MPAs often fail to reach their full potential as a consequence of factors such as illegal harvesting, regulations that legally allow detrimental harvesting, or emigration of animals outside boundaries because of continuous habitat or inadequate size of reserve. Here we show that the conservation benefits of 87 MPAs investigated worldwide increase exponentially with the accumulation of five key features: no take, well enforced, old (>10 years), large (>100 km2), and isolated by deep water or sand. Using effective MPAs with four or five key features as an unfished standard, comparisons of underwater survey data from effective MPAs with predictions based on survey data from fished coasts indicate that total fish biomass has declined about two-thirds from historical baselines as a result of fishing. Effective MPAs also had twice as many large (>250 mm total length) fish species per transect, five times more large fish biomass, and fourteen times more shark biomass than fished areas. Most (59%) of the MPAs studied had only one or two key features and were not ecologically distinguishable from fished sites. Our results show that global conservation targets based on area alone will not optimize protection of marine biodiversity. More emphasis is needed on better MPA design, durable management and compliance to ensure that MPAs achieve their desired conservation value.

Integrating abundance and functional traits reveals new global hotspots of fish diversity

Species richness has dominated our view of global biodiversity patterns for centuries. The dominance of this paradigm is reflected in the focus by ecologists and conservation managers on richness and associated occurrence-based measures for understanding drivers of broad-scale diversity patterns and as a biological basis for management. However, this is changing rapidly, as it is now recognized that not only the number of species but the species present, their phenotypes and the number of individuals of each species are critical in determining the nature and strength of the relationships between species diversity and a range of ecological functions (such as biomass production and nutrient cycling). Integrating these measures should provide a more relevant representation of global biodiversity patterns in terms of ecological functions than that provided by simple species counts. Here we provide comparisons of a traditional global biodiversity distribution measure based on richness with metrics that incorporate species abundances and functional traits. We use data from standardized quantitative surveys of 2,473 marine reef fish species at 1,844 sites, spanning 133 degrees of latitude from all ocean basins, to identify new diversity hotspots in some temperate regions and the tropical eastern Pacific Ocean. These relate to high diversity of functional traits amongst individuals in the community (calculated using Rao’s Q), and differ from previously reported patterns in functional diversity and richness for terrestrial animals, which emphasize species-rich tropical regions only. There is a global trend for greater evenness in the number of individuals of each species, across the reef fish species observed at sites (‘community evenness’), at higher latitudes. This contributes to the distribution of functional diversity hotspots and contrasts with well-known latitudinal gradients in richness. Our findings suggest that the contribution of species diversity to a range of ecosystem functions varies over large scales, and imply that in tropical regions, which have higher numbers of species, each species contributes proportionally less to community-level ecological processes on average than species in temperate regions. Metrics of ecological function usefully complement metrics of species diversity in conservation management, including when identifying planning priorities and when tracking changes to biodiversity values.

Pediatric Metabolic Syndrome Predicts Adulthood Metabolic Syndrome, Subclinical Atherosclerosis, and Type 2 Diabetes Mellitus but Is No Better Than Body Mass Index Alone The Bogalusa Heart Study and the Cardiovascular Risk in Young Finns Study

Background— The clinical utility of identifying pediatric metabolic syndrome (MetS) is controversial. This study sought to determine the status of pediatric MetS as a risk factor for adult subclinical atherosclerosis (carotid intima-media thickness [cIMT]) and type 2 diabetes mellitus (T2DM) and compare and contrast this prediction with its individual components. Methods and Results— Using data from the population-based, prospective, observational Bogalusa Heart and Cardiovascular Risk in Young Finns studies, we examined the utility of 4 categorical definitions of youth MetS and their components in predicting adult high cIMT and T2DM among 1781 participants aged 9 to 18 years at baseline (1984 to 1988) who were then examined 14 to 27 years later (2001–2007) when aged 24 to 41 years. Youth with MetS were at 2 to 3 times the risk of having high cIMT and T2DM as adults compared with those free of MetS at youth. Risk estimates with the use of high body mass index were similar to those of MetS phenotypes in predicting adult outcomes. Comparisons of area under the receiver operating characteristic curve and net reclassification index suggested that prediction of adult MetS, high cIMT, and T2DM in adulthood with the use of youth MetS was either equivalent or inferior to classification based on high body mass index or overweight and obesity. Conclusions— Youth with MetS are at increased risk of meaningful adult outcomes; however, the simplicity of screening for high BMI or overweight and obesity in the pediatric setting offers a simpler, equally accurate alternative to identifying youth at risk of developing adult MetS, high cIMT, or T2DM.

Common variants at 12q14 and 12q24 are associated with hippocampal volume

Aging is associated with reductions in hippocampal volume that are accelerated by Alzheimers disease and vascular risk factors. Our genome-wide association study (GWAS) of dementia-free persons (n = 9,232) identified 46 SNPs at four loci with P values of <4.0 × 10−7. In two additional samples (n = 2,318), associations were replicated at 12q14 within MSRB3-WIF1 (discovery and replication; rs17178006; P = 5.3 × 10−11) and at 12q24 near HRK-FBXW8 (rs7294919; P = 2.9 × 10−11). Remaining associations included one SNP at 2q24 within DPP4 (rs6741949; P = 2.9 × 10−7) and nine SNPs at 9p33 within ASTN2 (rs7852872; P = 1.0 × 10−7); along with the chromosome 12 associations, these loci were also associated with hippocampal volume (P < 0.05) in a third younger, more heterogeneous sample (n = 7,794). The SNP in ASTN2 also showed suggestive association with decline in cognition in a largely independent sample (n = 1,563). These associations implicate genes related to apoptosis (HRK), development (WIF1), oxidative stress (MSR3B), ubiquitination (FBXW8) and neuronal migration (ASTN2), as well as enzymes targeted by new diabetes medications (DPP4), indicating new genetic influences on hippocampal size and possibly the risk of cognitive decline and dementia.

Utility of Currently Recommended Pediatric Dyslipidemia Classifications in Predicting Dyslipidemia in Adulthood Evidence From the Childhood Determinants of Adult Health (CDAH) Study, Cardiovascular Risk in Young Finns Study, and Bogalusa Heart Study

Background— New age- and sex-specific lipoprotein cut points developed from National Health and Nutrition Examination Survey (NHANES) data are considered to be a more accurate classification of a high-risk lipoprotein level in adolescents compared with existing cut points established by the National Cholesterol Education Program (NCEP). The aim of this study was to determine which of the NHANES or NCEP adolescent lipoprotein classifications was most effective for predicting abnormal levels in adulthood. Methods and Results— Adolescent and adult measures of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides were collected in 365 Australian, 1185 Finnish, and 273 US subjects participating in 3 population-based prospective cohort studies. Lipoprotein variables in adolescence were classified according to NCEP and NHANES cut points and compared for their ability to predict abnormal levels in adulthood. With the use of diagnostic performance statistics (sensitivity, specificity, positive predictive value, negative predictive value, area under receiver operating characteristic curve) in pooled and cohort-stratified data, the NHANES cut points (compared with NCEP cut points) were more strongly predictive of low high-density lipoprotein cholesterol in adults but less predictive of high total cholesterol, high low-density lipoprotein cholesterol, and high triglyceride levels in adults. We identified heterogeneity in the relative usefulness of each classification between cohorts. Conclusions— The separate use of NHANES cut points for high-density lipoprotein cholesterol and NCEP cut points for total cholesterol, low-density lipoprotein cholesterol, and triglycerides yielded the most accurate classification of adolescents who developed dyslipidemia in adulthood.

The Association of Pediatric Low- and High-Density Lipoprotein Cholesterol Dyslipidemia Classifications and Change in Dyslipidemia Status With Carotid Intima-Media Thickness in Adulthood : Evidence From the Cardiovascular Risk in Young Finns Study, the Bogalusa Heart Study, and the CDAH (Childhood Determinants of Adult Health) Study

OBJECTIVES This study was designed to determine which of the National Cholesterol Education Program or National Health and Nutrition Examination Survey low- and high-density lipoprotein cholesterol classifications of dyslipidemia status in adolescents is most effective at predicting high common carotid artery intima-media thickness (IMT) in adulthood. BACKGROUND Two classifications of pediatric dyslipidemia status have been proposed. No study has assessed which of these is most effective for predicting adolescents who will develop preclinical atherosclerosis in adulthood. METHODS Three population-based, prospective cohort studies collected lipoprotein measurements on 1,711 adolescents age 12 to 18 years who were remeasured as young adults age 29 to 39 years. Lipoproteins in adolescence were classified according to National Cholesterol Education Program and National Health and Nutrition Examination Survey cut points, and high IMT in adulthood was defined as those at or above the age-, sex-, race-, and cohort-specific 90th percentile of IMT. RESULTS Independent of the classification employed, adolescents with dyslipidemia were at significantly increased risk of having high IMT in adulthood (relative risks from 1.6 to 2.5). Differences in predictive capacity between both classifications were minimal. Overweight or obese adolescents with dyslipidemia had increased carotid IMT (males: 0.11 mm; females: 0.08 mm) in adulthood compared with those who did not have both risk factors. Adolescent dyslipidemia status was more strongly associated with high IMT in adulthood than change in dyslipidemia status. CONCLUSIONS Pediatric dyslipidemia classifications perform equally in the prediction of adolescents who are at increased risk of high IMT in young adulthood. Our data suggest that dyslipidemia screening could be limited to overweight or obese adolescents.

Decline in Physical Fitness From Childhood to Adulthood Associated With Increased Obesity and Insulin Resistance in Adults

OBJECTIVE To examine how fitness in both childhood and adulthood is associated with adult obesity and insulin resistance. RESEARCH DESIGN AND METHODS A prospective cohort study set in Australia in 2004–2006 followed up a cohort of 647 adults who had participated in the Australian Schools Health and Fitness Survey in 1985 and who had undergone anthropometry and cardiorespiratory fitness assessment during the survey. Outcome measures were insulin resistance and obesity, defined as a homeostasis model assessment index above the 75th sex-specific percentile and BMI ≥30 kg/m2, respectively. RESULTS Lower levels of child cardiorespiratory fitness were associated with increased odds of adult obesity (adjusted odds ratio [OR] per unit decrease 3.0 [95% CI 1.6–5.6]) and insulin resistance (1.7 [1.1–2.6]). A decline in fitness level between childhood and adulthood was associated with increased obesity (4.5 [2.6–7.7]) and insulin resistance (2.1 [1.5–2.9]) per unit decline. CONCLUSIONS A decline in fitness from childhood to adulthood, and by inference a decline in physical activity, is associated with obesity and insulin resistance in adulthood. Programs aimed at maintaining high childhood physical activity levels into adulthood may have potential for reducing the burden of obesity and type 2 diabetes in adults.

A New Rodent Model to Assess Blood Stage Immunity to the Plasmodium falciparum Antigen Merozoite Surface Protein 119 Reveals a Protective Role for Invasion Inhibitory Antibodies

Antibodies capable of inhibiting the invasion of Plasmodium merozoites into erythrocytes are present in individuals that are clinically immune to the malaria parasite. Those targeting the 19-kD COOH-terminal domain of the major merozoite surface protein (MSP)-119 are a major component of this inhibitory activity. However, it has been difficult to assess the overall relevance of such antibodies to antiparasite immunity. Here we use an allelic replacement approach to generate a rodent malaria parasite (Plasmodium berghei) that expresses a human malaria (Plasmodium falciparum) form of MSP-119. We show that mice made semi-immune to this parasite line generate high levels of merozoite inhibitory antibodies that are specific for P. falciparum MSP-119. Importantly, protection from homologous blood stage challenge in these mice correlated with levels of P. falciparum MSP-119–specific inhibitory antibodies, but not with titres of total MSP-119–specific immunoglobulins. We conclude that merozoite inhibitory antibodies generated in response to infection can play a significant role in suppressing parasitemia in vivo. This study provides a strong impetus for the development of blood stage vaccines designed to generate invasion inhibitory antibodies and offers a new animal model to trial P. falciparum MSP-119 vaccines.

A Comparison of Subjective and Objective Measures of Physical Activity and Fitness in Identifying Associations with Cardiometabolic Risk Factors

PURPOSE To compare the ability of alternative measures of physical activity and fitness to quantify associations with health outcomes. METHODS Associations between a range of subjective and objective physical activity and fitness measures and cardiometabolic risk factors were examined using data from 1,631 Australians aged 26-36 years. Anthropometry, fitness, blood pressure, and fasting blood glucose, insulin, and lipids were measured at study clinics. Participants completed the International Physical Activity Questionnaire (IPAQ) and 7-day pedometer diaries; they also reported sedentary behavior (sitting, television viewing). RESULTS In men and women, associations were strongest for fitness, with those in the highest (vs. lowest) fitness quarter having a 75% to 80% lower prevalence of two or more primary risk factors (waist circumference, high-density lipoprotein cholesterol, and insulin resistance). In men, a 60% to 70% reduced prevalence of two or more risk factors was observed across extreme quarters of IPAQ leisure, IPAQ vigorous, sitting duration, and pedometer measures. Similar reductions in prevalence were observed only across extreme quarters of pedometer activity and television viewing in women. CONCLUSIONS Associations between alternative measures and cardiometabolic risk were relatively independent, suggesting that a range of physical activity and fitness measures may be needed to most accurately quantify associations between physical activity and health.

Cognitive Function, Gait, and Gait Variability in Older People: A Population-Based Study

BACKGROUND Gait impairments are associated with falls and loss of independence. The study of factors associated with poorer gait may assist in developing methods to preserve mobility in older people. The aim of this study was to examine the associations between a range of cognitive functions and gait and gait variability in a population-based sample of older people. METHODS Gait and intra-individual gait variability measures were obtained using the GAITRite walkway in a sample of older people, aged 60-85 years (N = 422), randomly selected from the Tasmanian electoral roll. Raw scores from a cognitive battery were subjected to principal component analyses deriving four summary domains: executive function/attention, processing speed, memory, and visuospatial ability. Multivariable linear regression was used to examine associations between cognitive domains and gait measures adjusting for age, sex, ambulatory activity, medication use, and mood. RESULTS The mean age of the sample was 72.0 years (SD = 7.0), with 238 men (56%). Poorer executive function was independently associated with poorer performance in most absolute gait measures and with greater variability in double support phase and step time. Processing speed was associated with absolute gait measures and double support phase variability. Visuospatial ability was only associated with greater double support phase variability, independently of executive function and processing speed. Memory was not independently associated with any gait measure. CONCLUSIONS In community-dwelling older people, executive function/attention and processing speed were associated with many aspects of gait, whereas visuospatial ability may only play a role in double support phase variability.