Long-distance dispersal in the short-distance dispersing house sparrow (Passer domesticus)

The house sparrow (Passer domesticus) is a small passerine known to be highly sedentary. Throughout a 30-year capture-mark-recapture study, we have obtained occasional reports of recoveries far outside our main metapopulation study system, documenting unusually long dispersal distances. Our records constitute the highest occurrence of long-distance dispersal events recorded for this species in Scandinavia. Such long-distance dispersals radically change the predicted distribution of dispersal distances and connectedness for our study metapopulation. Moreover, it reveals a much greater potential for colonization than formerly recorded for the house sparrow, which is an invasive species across four continents. These rare and occasional long-distance dispersal events are challenging to document but may have important implications for the genetic composition of small and isolated populations and for our understanding of dispersal ecology and evolution.

Taylor Dispersion-Induced Phase Separation for the Efficient Characterisation of Protein Condensate Formation

Biomolecular condensates have emerged as important structures in cellular function and disease, and are thought to form through liquid-liquid phase separation (LLPS). Thorough and efficient in vitro experiments are therefore needed to elucidate the driving forces of protein LLPS and the possibility to modulate it with drugs. Here we present Taylor dispersion-induced phase separation (TDIPS), a method to robustly measure condensation phenomena using a commercially available microfluidic platform. It uses only nanoliters of sample, does not require extrinsic fluorescent labels, and is straightforward to implement. We demonstrate TDIPS by screening the phase behaviour of two proteins that form biomolecular condensates in vivo, PGL-3 and Ddx4. Uniquely accessible to this method, we find an unexpected re-entrant behaviour at very low ionic strength, where LLPS is inhibited for both proteins. TDIPS can also probe the reversibility of assemblies, which was shown for both α-synuclein and for lysozyme, relevant for health and biotechnology, respectively. Finally, we highlight how effective inhibition concentrations and partitioning of LLPS-modifying compounds can be screened highly efficiently.

Calling Structural Variants with Confidence from Short-Read Data in Wild Bird Populations

Comprehensive characterization of structural variation in natural populations has only become feasible in the last decade. To investigate the population genomic nature of structural variation, reproducible and high-confidence structural variation callsets are first required. We created a population-scale reference of the genome-wide landscape of structural variation across 33 Nordic house sparrows (Passer domesticus). To produce a consensus callset across all samples using short-read data, we compare heuristic-based quality filtering and visual curation (Samplot/PlotCritic and Samplot-ML) approaches. We demonstrate that curation of structural variants is important for reducing putative false positives and that the time invested in this step outweighs the potential costs of analyzing short-read-discovered structural variation data sets that include many potential false positives. We find that even a lenient manual curation strategy (e.g. applied by a single curator) can reduce the proportion of putative false positives by up to 80%, thus enriching the proportion of high-confidence variants. Crucially, in applying a lenient manual curation strategy with a single curator, nearly all (>99%) variants rejected as putative false positives were also classified as such by a more stringent curation strategy using three additional curators. Furthermore, variants rejected by manual curation failed to reflect the expected population structure from SNPs, whereas variants passing curation did. Combining heuristic-based quality filtering with rapid manual curation of structural variants in short-read data can therefore become a time- and cost-effective first step for functional and population genomic studies requiring high-confidence structural variation callsets.

The genetic basis of dispersal in a vertebrate metapopulation

Dispersal affects evolutionary processes by changing population size and genetic composition, influencing the viability and persistence of populations. Investigating which mechanisms underlie variation in dispersal phenotypes and whether populations harbour adaptive potential for dispersal is crucial to understanding the eco-evolutionary dynamics of this important trait. Here, we investigate the genetic architecture of dispersal among successfully recruited individuals in an insular metapopulation of house sparrows. We use an extensive long-term individual-based ecological data set and high-density single-nucleotide polymorphism (SNP) genotypes for over 2500 individuals. We conducted a genome-wide association study (GWAS), and found a relationship between dispersal probability and a SNP located near genes known to regulate circadian rhythm, glycogenesis and exercise performance, among other functions. However, this SNP only explained 3.8% of variance, suggesting that dispersal is a polygenic trait. We then used an animal model to estimate heritable genetic variation (σA 2 ), which composes 10% of the total variation in dispersal probability. Finally, we investigated differences in σA 2 across populations occupying ecologically relevant habitat types (farm vs. non-farm) using a genetic groups animal model. We found different adaptive potentials across habitats, with higher mean breeding value, σA 2 , and heritability for the habitat presenting lower dispersal rates, suggesting also different roles of environmental variation. Our results suggest a complex genetic architecture of dispersal and demonstrate that adaptive potential may be environment dependent in key eco-evolutionary traits. The eco-evolutionary implications of such environment dependence and consequent spatial variation are likely to become ever more important with the increased fragmentation and loss of suitable habitats for many natural populations.

Lead exposure is related to higher infection rate with the gapeworm in Norwegian house sparrows (Passer domesticus)

Anthropogenic pollution is identified as an important threat to bird and other wildlife populations. Many metals and toxic elements, along with poly- and perfluoroalkyl substances (PFASs) are known to induce immunomodulation and have previously been linked to increased pathogen prevalence and infectious disease severity. In this study, the house sparrow (Passer domesticus) was investigated at the coast of Helgeland in northern Norway. This population is commonly infected with the parasitic nematode "gapeworm" (Syngamus trachea), with a prevalence of 40-60 % during summer months. Gapeworm induces severe respiratory disease in birds and has been previously demonstrated to decrease survival and reproductive success in wild house sparrows. The aim of this study was to investigate whether a higher exposure to pollution with PFASs, metals and other elements influences gapeworm infection in wild house sparrows. We conducted PFASs and elemental analysis on whole blood from 52 house sparrows from Helgeland, including analyses of highly toxic metals such as lead (Pb), mercury (Hg) and arsenic (As). In addition, we studied gapeworm infection load by counting the parasite eggs in faeces from each individual. We also studied the expression of microRNA 155 (miR155) as a key regulator in the immune system. Elevated blood concentrations of Pb were found to be associated with an increased prevalence of gapeworm infection in the house sparrow. The expression of miR155 in the plasma of the house sparrow was only weakly associated with Pb. In contrast, we found relatively low PFASs concentrations in the house sparrow blood (∑ PFASs 0.00048-354 μg/L) and PFASs were not associated to miR155 nor infection rate. The current study highlights the potential threat posed by Pb as an immunotoxic pollutant in small songbirds.

Multigenerational Fitness Effects of Natural Immigration Indicate Strong Heterosis and Epistatic Breakdown in a Wild Bird Population

AbstractThe fitness of immigrants and their descendants produced within recipient populations fundamentally underpins the genetic and population dynamic consequences of immigration. Immigrants can in principle induce contrasting genetic effects on fitness across generations, reflecting multifaceted additive, dominance, and epistatic effects. Yet full multigenerational and sex-specific fitness effects of regular immigration have not been quantified within naturally structured systems, precluding inference on underlying genetic architectures and population outcomes. We used four decades of song sparrow (Melospiza melodia) life history and pedigree data to quantify fitness of natural immigrants, natives, and their F1, F2, and backcross descendants and test for evidence of nonadditive genetic effects. Values of key fitness components (including adult lifetime reproductive success and zygote survival) of F1 offspring of immigrant-native matings substantially exceeded their parent mean, indicating strong heterosis. Meanwhile, F2 offspring of F1-F1 matings had notably low values, indicating surprisingly strong epistatic breakdown. Furthermore, magnitudes of effects varied among fitness components and differed between female and male descendants. These results demonstrate that strong nonadditive genetic effects on fitness can arise within weakly structured and fragmented populations experiencing frequent natural immigration. Such effects will substantially affect the net degree of effective gene flow and resulting local genetic introgression and adaptation.

Contrasting genomic consequences of anthropogenic reintroduction and natural recolonization in high-arctic wild reindeer

Anthropogenic reintroduction can supplement natural recolonization in reestablishing a species' distribution and abundance. However, both reintroductions and recolonizations can give rise to founder effects that reduce genetic diversity and increase inbreeding, potentially causing the accumulation of genetic load and reduced fitness. Most current populations of the endemic high-arctic Svalbard reindeer (Rangifer tarandus platyrhynchus) originate from recent reintroductions or recolonizations following regional extirpations due to past overharvesting. We investigated and compared the genomic consequences of these two paths to reestablishment using whole-genome shotgun sequencing of 100 Svalbard reindeer across their range. We found little admixture between reintroduced and natural populations. Two reintroduced populations, each founded by 12 individuals around four decades (i.e. 8 reindeer generations) ago, formed two distinct genetic clusters. Compared to the source population, these populations showed only small decreases in genome-wide heterozygosity and increases in inbreeding and lengths of runs of homozygosity. In contrast, the two naturally recolonized populations without admixture possessed much lower heterozygosity, higher inbreeding and longer runs of homozygosity, possibly caused by serial population founder effects and/or fewer or more genetically related founders than in the reintroduction events. Naturally recolonized populations can thus be more vulnerable to the accumulation of genetic load than reintroduced populations. This suggests that in some organisms even small-scale reintroduction programs based on genetically diverse source populations can be more effective than natural recolonization in establishing genetically diverse populations. These findings warrant particular attention in the conservation and management of populations and species threatened by habitat fragmentation and loss.

Spatial variation in the evolutionary potential and constraints of basal metabolic rate and body mass in a wild bird

An organism's energy budget is strongly related to resource consumption, performance, and fitness. Hence, understanding the evolution of key energetic traits, such as basal metabolic rate (BMR), in natural populations is central for understanding life-history evolution and ecological processes. Here we used quantitative genetic analyses to study evolutionary potential of BMR in two insular populations of the house sparrow (Passer domesticus). We obtained measurements of BMR and body mass (M_b ) from 911 house sparrows on the islands of Leka and Vega along the coast of Norway. These two populations were the source populations for translocations to create an additional third, admixed 'common garden' population in 2012. With the use of a novel genetic group animal model concomitant with a genetically determined pedigree, we differentiate genetic and environmental sources of variation, thereby providing insight into the effects of spatial population structure on evolutionary potential. We found that the evolutionary potential of BMR was similar in the two source populations, whereas the Vega population had a somewhat higher evolutionary potential of M_b than the Leka population. BMR was genetically correlated with M_b in both populations, and the conditional evolutionary potential of BMR (independent of body mass) was 41% (Leka) and 53% (Vega) lower than unconditional estimates. Overall, our results show that there is potential for BMR to evolve independently of M_b , but that selection on BMR and/or M_b may have different evolutionary consequences in different populations of the same species.

Photocatalytic-treated asphalt road in Copenhagen for urban NO x removal

Atmospheric nitrogen oxides ( NO x = NO + NO 2 ) are key pollutants and short-lived climate forcers contributing to acid rain, photochemical smog, aerosol formation and climate change. Exposure to nitrogen dioxide ( NO 2 ) emitted mainly from transportation, causes adverse health effects associated with respiratory illnesses and increased mortality even at low concentration. Application of titanium dioxide ( TiO 2 )-based photocatalysis in urban environment is a new air cleaning solution, activated by sunlight and water vapour to produce OH radicals, able to remove NO x and other pollutants from the planetary boundary layer. This study is a large-scale evaluation of NO x removal efficiency at a near-road environment with applied photocatalytic NOxOFF™ technology on an urban road west of Copenhagen, thus supporting local municipality in meeting their clean-air Agenda 2030. The photocatalytic NOxOFF™ granulate containing TiO 2 nanoparticles was applied on an asphalt road in July 2020 and ambient NO x was measured during a six-month monitoring campaign. It is the first NO x monitoring campaign carried out at this road and specific efforts have been devoted to evaluate the reduction in ambient NO x levels with NOxOFF™-treated asphalt. Several methods were used to evaluate the photocatalytic effect, taking into account analysis limitations such as the short reference period prior to application and the highly uncertain measurement period during which SARS-CoV-2 lockdown measures impacted air quality. There was no statistically significant difference in NO x concentrations between the reference period and the photocatalytic active period and NO removal efficiency resulted in - 0.17 (± 1.27). An upper limit removal of 17.5% NO x was estimated using a kinetic tunnel model. While NO 2 comparison with COPERT V street traffic model projection was roughly estimated to decrease by 39% (± 38%), although this estimate is subject to high uncertainty. The observed annual mean NO 2 concentration complies with Frederiksberg clean-air Agenda 2030 and air quality standards.

GRAPHICAL ABSTRACT

A graphical abstract illustrating the air cleaning properties of TiO 2 -based photocatalytic-treated asphalt.

Genetic architecture and heritability of early-life telomere length in a wild passerine

Early-life telomere length (TL) is associated with fitness in a range of organisms. Little is known about the genetic basis of variation in TL in wild animal populations, but to understand the evolutionary and ecological significance of TL it is important to quantify the relative importance of genetic and environmental variation in TL. In this study, we measured TL in 2746 house sparrow nestlings sampled across 20 years and used an animal model to show that there is a small heritable component of early-life TL (h²  = 0.04). Variation in TL among individuals was mainly driven by environmental (annual) variance, but also brood and parental effects. Parent-offspring regressions showed a large maternal inheritance component in TL ( h maternal 2  = 0.44), but no paternal inheritance. We did not find evidence for a negative genetic correlation underlying the observed negative phenotypic correlation between TL and structural body size. Thus, TL may evolve independently of body size and the negative phenotypic correlation is likely to be caused by nongenetic environmental effects. We further used genome-wide association analysis to identify genomic regions associated with TL variation. We identified several putative genes underlying TL variation; these have been inferred to be involved in oxidative stress, cellular growth, skeletal development, cell differentiation and tumorigenesis in other species. Together, our results show that TL has a low heritability and is a polygenic trait strongly affected by environmental conditions in a free-living bird.

Artificial size selection experiment reveals telomere length dynamics and fitness consequences in a wild passerine

Telomere dynamics could underlie life-history trade-offs among growth, size and longevity, but our ability to quantify such processes in natural, unmanipulated populations is limited. We investigated how 4 years of artificial selection for either larger or smaller tarsus length, a proxy for body size, affected early-life telomere length (TL) and several components of fitness in two insular populations of wild house sparrows over a study period of 11 years. The artificial selection was expected to shift the populations away from their optimal body size and increase the phenotypic variance in body size. Artificial selection for larger individuals caused TL to decrease, but there was little evidence that TL increased when selecting for smaller individuals. There was a negative correlation between nestling TL and tarsus length under both selection regimes. Males had longer telomeres than females and there was a negative effect of harsh weather on TL. We then investigated whether changes in TL might underpin fitness effects due to the deviation from the optimal body size. Mortality analyses indicated disruptive selection on TL because both short and long early-life telomeres tended to be associated with the lowest mortality rates. In addition, there was a tendency for a negative association between TL and annual reproductive success, but only in the population where body size was increased experimentally. Our results suggest that natural selection for optimal body size in the wild may be associated with changes in TL during growth, which is known to be linked to longevity in some bird species.

Assessing how routes to diagnosis vary by the age of patients with cancer: a nationwide register-based cohort study in Denmark

BACKGROUND

Older patients with cancer have poorer prognosis compared to younger patients. Moreover, prognosis is related to how cancer is identified, and where in the healthcare system patients present, i.e. routes to diagnosis (RtD). We investigated whether RtD varied by patients' age.

METHODS

This population-based national cohort study used Danish registry data. Patients were categorized into age groups and eight mutually exclusive RtD. We employed multinomial logistic regressions adjusted for sex, region, diagnosis year, cohabitation, education, income, immigration status and comorbidities. Screened and non-screened patients were analysed separately.

RESULTS

The study included 137,876 patients. Both younger and older patients with cancer were less likely to get diagnosed after a cancer patient pathways referral from primary care physician compared to middle-aged patients. Older patients were more likely to get diagnosed via unplanned admission, death certificate only, and outpatient admission compared to younger patients. The patterns were similar across comorbidity levels.

CONCLUSIONS

RtD varied by age groups, and middle-aged patients were the most likely to get diagnosed after cancer patient pathways with referral from primary care. Emphasis should be put on raising clinicians' awareness of cancer being the underlying cause of symptoms in both younger patients and in older patients.

Causes and consequences of variation in early-life telomere length in a bird metapopulation

Environmental conditions during early-life development can have lasting effects shaping individual heterogeneity in fitness and fitness-related traits. The length of telomeres, the DNA sequences protecting chromosome ends, may be affected by early-life conditions, and telomere length (TL) has been associated with individual performance within some wild animal populations. Thus, knowledge of the mechanisms that generate variation in TL, and the relationship between TL and fitness, is important in understanding the role of telomeres in ecology and life-history evolution. Here, we investigate how environmental conditions and morphological traits are associated with early-life blood TL and if TL predicts natal dispersal probability or components of fitness in 2746 wild house sparrow (Passer domesticus) nestlings from two populations sampled across 20 years (1994-2013). We retrieved weather data and we monitored population fluctuations, individual survival, and reproductive output using field observations and genetic pedigrees. We found a negative effect of population density on TL, but only in one of the populations. There was a curvilinear association between TL and the maximum daily North Atlantic Oscillation index during incubation, suggesting that there are optimal weather conditions that result in the longest TL. Dispersers tended to have shorter telomeres than non-dispersers. TL did not predict survival, but we found a tendency for individuals with short telomeres to have higher annual reproductive success. Our study showed how early-life TL is shaped by effects of growth, weather conditions, and population density, supporting that environmental stressors negatively affect TL in wild populations. In addition, shorter telomeres may be associated with a faster pace-of-life, as individuals with higher dispersal rates and annual reproduction tended to have shorter early-life TL.

OP0037 USE OF PRIMARY HEALTHCARE AND RADIOLOGICAL IMAGING PRECEDING A DIAGNOSIS OF RHEUMATOID ARTHRITIS: A DANISH NATIONWIDE COHORT STUDY

Background

Focus on early diagnosis and treatment initiation is key in rheumatoid arthritis (RA) to prevent permanent joint damage and systemic manifestations. Increased use of healthcare services before an RA diagnosis can be seen as a proxy for symptom presentation and the actions taken by healthcare professionals, and thus indicate an opportunity for earlier diagnosis. However, little is known about where and when people use healthcare services before an RA diagnosis.

Objectives

To explore the pattern in use of healthcare services during the 12 months preceding a diagnosis of RA in Denmark.

Methods

We conducted a population-based cohort study using data from Danish national registries. For every patient diagnosed with RA in 2014-2018 we matched ten reference persons from the Danish general population without RA, listed in the same general practice and with same age and sex. Healthcare use was defined as: daytime face to face contacts to general practice, contacts to private practicing physiotherapists.

We estimated the monthly healthcare use for patients with RA and reference persons in the 12 months preceding the diagnosis, and we compared their healthcare use by incidence rate ratios (IRR) for each month, adjusted for sociodemographic characteristics and comorbidity.

Results

7,427 patients with RA and 74,270 reference persons were included in the study. The median age was 62 years (interquartile interval (IQI): 51-71), and 65% were women. Patients with RA had an average of 0.5 contacts per month in general practice from 12 months until six months prior to the diagnosis (Figure 1); this number increased from six months before the diagnosis to an average of one contact in the last month before the diagnosis. Reference persons had an average of 0.4 contacts per months throughout the entire study period. Compared to their references, patients with RA had statistically significantly more contacts during all 12 months before the diagnosis date; IRR increased from 1.25 (95% CI: 1.19-1.30) to 2.63 (2.55-2.71) during the study period.

Patients with RA also had statstistically significantly more contacts to physiotherapists compared to their references throughout the entire study period, and increasing contact rates from eight months before the diagnosis. This was primarily driven by more contacts in women with RA compared to their references.

Conclusion

Patients with RA had more contacts to general practice and physiotherapists in all 12 months preceding the RA diagnosis compared to references and these contact rates increased further the last six to eight months in patients with RA. This indicates symptom presentation for several months before the RA is diagnosed, and it indicates that a window of opportunity exists to expedite referral to specialist care and the diagnosis of RA.

Disclosure of Interests

None declared.

Abstract 11043: Clinical Safety Outcomes in Relation to Lipoprotein(a) Concentration: Insights from the FOURIER Trial

Background: Lipoprotein(a) is believed to play a causal role in atherogenesis. Drugs are in development that directly target Lp(a) and lower levels by >75%. Thus, the safety of low Lp(a) levels is of importance.

Methods: FOURIER randomized 27,564 patients w/ stable ASCVD to evolocumab (EVO) vs placebo on background statin (median f/up 2.2 y); EVO lowered Lp(a) levels by 27%. The relationships between Lp(a) levels, change in Lp(a) and 5 safety outcomes of interest based on prior reports (diabetes [DM], serious bleeding, hemorrhagic stroke, neurocognitive events, malignancy) were examined. Analyses were conducted in the overall population and by treatment arm. Multivariable models included age, sex, race, region, clinical predictors, high-intensity statin, ezetimibe, baseline hs-CRP, “Lp(a)-corrected” LDL-C, and treatment arm.

Results: Lp(a) was assessed in 25,083 participants at baseline (median 37nM, range 5-1451) and 25,686 at week 12. There was no association between baseline or achieved Lp(a) levels and risk of serious bleeding, hemorrhagic stroke, neurocognitive events, or malignancy, even in the 3271 patients with Lp(a) levels ≤6nM. There was an inverse association between baseline Lp(a) levels and prevalent or incident DM [OR 1.09, 95%CI 1.07-1.12, for every 50nM lower Lp(a) below 250nM]. However, absolute change in Lp(a) with EVO was not associated with subsequent DM risk (HR 1.03, 0.91-1.16, per 50nM) and EVO did not increase the risk of DM irrespective of baseline Lp(a) (P int=0.97), even in participants in the top decile of baseline Lp(a) (HR 0.91, 0.51-1.62) in whom EVO reduced Lp(a) by 63nM.

Conclusion: Lp(a) concentration and changes in Lp(a) were not associated with serious bleeding, hemorrhagic stroke, neurocognitive events, or malignancy. Levels were inversely correlated with having DM, but Lp(a) lowering over a median of 2.2 years with EVO did not further increase the risk. These findings provide new insights for ongoing trials of Lp(a)-lowering drugs.

Distribution of natural and anthropogenic radionuclides in sediments from the Vefsnfjord, Norway

Areas in central Norway were heavily contaminated with fallout from the Chernobyl accident in 1986. In this study, we assess ¹³⁷Cs in surface sediments and sediment cores collected in the Vefsnfjord in Nordland county. Concentrations of ¹³⁷Cs in surface sediments ranged from 159 to 191 Bq kg^-1 dry weight (d.w.). Sub-surface peaks of ¹³⁷Cs were observed in all cores, with a maximum concentration of 432 Bq kg^-1 d.w. Given that little is known about the distribution of naturally occurring radionuclides in Norwegian fjords and coastal areas, a better understanding of the total burden of radioactivity is important for the Norwegian fishing and aquaculture industries. Therefore, analyses of the natural radionuclides ⁴⁰K, ²²⁶Ra, ²²⁸Ra and ²¹⁰Pb were included in the study. Analyses of total sulphur (TS), total carbon (TC), total organic carbon (TOC) and grain size distribution have been performed to provide a sedimentologic context for interpreting the radionuclide results.

Fur colour in the Arctic fox: genetic architecture and consequences for fitness

Genome-wide association studies provide good opportunities for studying the genetic basis of adaptive traits in wild populations. Yet, previous studies often failed to identify major effect genes. In this study, we used high-density single nucleotide polymorphism and individual fitness data from a wild non-model species. Using a whole-genome approach, we identified the MC1R gene as the sole causal gene underlying Arctic fox Vulpes lagopus fur colour. Further, we showed the adaptive importance of fur colour genotypes through measures of fitness that link ecological and evolutionary processes. We found a tendency for blue foxes that are heterozygous at the fur colour locus to have higher fitness than homozygous white foxes. The effect of genotype on fitness was independent of winter duration but varied with prey availability, with the strongest effect in years of increasing rodent populations. MC1R is located in a genomic region with high gene density, and we discuss the potential for indirect selection through linkage and pleiotropy. Our study shows that whole-genome analyses can be successfully applied to wild species and identify major effect genes underlying adaptive traits. Furthermore, we show how this approach can be used to identify knowledge gaps in our understanding of interactions between ecology and evolution.

Are immigrants outbred and unrelated? Testing standard assumptions in a wild metapopulation

Immigration into small recipient populations is expected to alleviate inbreeding and increase genetic variation, and hence facilitate population persistence through genetic and/or evolutionary rescue. Such expectations depend on three standard assumptions: that immigrants are outbred, unrelated to existing natives at arrival, and unrelated to each other. These assumptions are rarely explicitly verified, including in key field systems in evolutionary ecology. Yet, they could be violated due to non-random or repeated immigration from adjacent small populations. We combined molecular genetic marker data for 150-160 microsatellite loci with comprehensive pedigree data to test the three assumptions for a song sparrow (Melospiza melodia) population that is a model system for quantifying effects of inbreeding and immigration in the wild. Immigrants were less homozygous than existing natives on average, with mean homozygosity that closely resembled outbred natives. Immigrants can therefore be considered outbred on the focal population scale. Comparisons of homozygosity of real or hypothetical offspring of immigrant-native, native-native and immigrant-immigrant pairings implied that immigrants were typically unrelated to existing natives and to each other. Indeed, immigrants' offspring would be even less homozygous than outbred individuals on the focal population scale. The three standard assumptions of population genetic and evolutionary theory were consequently largely validated. Yet, our analyses revealed some deviations that should be accounted for in future analyses of heterosis and inbreeding depression, implying that the three assumptions should be verified in other systems to probe patterns of non-random or repeated dispersal and facilitate precise and unbiased estimation of key evolutionary parameters.

Geochronology of sediment cores from the Vefsnfjord, Norway

The sedimentary environment is a repository and carrier for a variety of pollutants, and sediment transport from land to coastal areas is an important environmental process. In the present study, we use ²¹⁰Pb/²²⁶Ra and ¹³⁷Cs in sediment cores to assess sediment supply rates at four sites within the Vefsnfjord in Nordland county, Norway. This area was highly affected by fallout from the Chernobyl accident in 1986 and inventories of ¹³⁷Cs in the fjord are much higher than in many other Norwegian fjords. Sedimentation rates between 0.042 and 0.25 g cm^-2 y^-1 (0.060 and 0.38 cm y^-1) were determined using a combination of the Constant Rate of Supply (CRS) and Constant Flux:Constant Sedimentation rate (CF:CS) models. Well-defined ¹³⁷Cs concentration peaks were used as a supplementary tool to the ²¹⁰Pb dating methods.

Spatial structure and dispersal dynamics in a house sparrow metapopulation

The effects of spatial structure on metapopulation dynamics depend upon the interaction between local population dynamics and dispersal, and how this relationship is affected by the geographical isolation and spatial heterogeneity in habitat characteristics. Our aim is to examine how emigration and immigration of house sparrows Passer domesticus in a Norwegian archipelagic metapopulation are affected by key factors predicted by classic metapopulation models to affect dispersal-spatial and temporal variation in population size, inter-island distance, local demography and habitat characteristics. This metapopulation can be divided into two major habitat types: (a) islands closer to the mainland where sparrows breed in colonies on farms, and (b) islands without farms, situated farther away from the mainland where sparrows are exposed to harsher environmental conditions. Dispersal was spatially structured within the metapopulation; there was proportionally and numerically less emigration and immigration involving farm islands, as compared to non-farm islands. Furthermore, emigration and immigration occurred mostly between nearby islands. Moreover, emigration in response to spatial differences in mean population size differed between the habitat types, but populations with large mean received more immigrants in both habitat types. The number of emigrants and immigrants was negatively related to long-term recruit production, which was not the case in non-farm islands. The proportion and number of emigrants was positively related to temporal increases in recruit production on farm islands, however not on non-farm islands. Our results demonstrate that spatial heterogeneity in environmental conditions influences how spatial variation in long-term mean population size, and temporal and spatial variation in recruit production, affects dispersal dynamics. The spatial structure of this metapopulation is therefore best described by a spatially explicit model in which the exchange of individuals within each habitat type is strongly affected by the degree of geographical isolation, population size and recruit production. However, these relationships differed between the two habitat types; non-farm islands showing similarities to a mainland-island model type of structure, whereas farm islands showed features more associated with source-sink or balanced dispersal models. Such differential dispersal dynamics between habitat types are expected to have important consequences for the ecological and evolutionary dynamics within this metapopulation.

Variation in generation time reveals density regulation as an important driver of pace of life in a bird metapopulation

Generation time determines the pace of key demographic and evolutionary processes. Quantified as the weighted mean age at reproduction, it can be studied as a life-history trait that varies within and among populations and may evolve in response to ecological conditions. We combined quantitative genetic analyses with age- and density-dependent models to study generation time variation in a bird metapopulation. Generation time was heritable, and males had longer generation times than females. Individuals with longer generation times had greater lifetime reproductive success but not a higher expected population growth rate. Density regulation acted on recruit production, suggesting that longer generation times should be favoured when populations are closer to carrying capacity. Furthermore, generation times were shorter when populations were growing and longer when populations were closer to equilibrium or declining. These results support classic theory predicting that density regulation is an important driver of the pace of life-history strategies.

Dispersal in a house sparrow metapopulation: An integrative case study of genetic assignment calibrated with ecological data and pedigree information

Dispersal has a crucial role determining ecoevolutionary dynamics through both gene flow and population size regulation. However, to study dispersal and its consequences, one must distinguish immigrants from residents. Dispersers can be identified using telemetry, capture-mark-recapture (CMR) methods, or genetic assignment methods. All of these methods have disadvantages, such as high costs and substantial field efforts needed for telemetry and CMR surveys, and adequate genetic distance required in genetic assignment. In this study, we used genome-wide 200K Single Nucleotide Polymorphism data and two different genetic assignment approaches (GSI_SIM, Bayesian framework; BONE, network-based estimation) to identify the dispersers in a house sparrow (Passer domesticus) metapopulation sampled over 16 years. Our results showed higher assignment accuracy with BONE. Hence, we proceeded to diagnose potential sources of errors in the assignment results from the BONE method due to variation in levels of interpopulation genetic differentiation, intrapopulation genetic variation and sample size. We show that assignment accuracy is high even at low levels of genetic differentiation and that it increases with the proportion of a population that has been sampled. Finally, we highlight that dispersal studies integrating both ecological and genetic data provide robust assessments of the dispersal patterns in natural populations.

OP0159-HPR IMPACT OF NON-PHARMACOLOGICAL INTERVENTIONS TARGETING SLEEP DISTURBANCES OR DISORDERS IN PATIENTS WITH INFLAMMATORY ARTHRITIS: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMISED TRIALS

Background:

Patients with inflammatory arthritis (IA) often present limitations in daily life due to unpredictability, severity and chronicity of the disease, reduced functional ability and health-related quality of life. Moreover, sleep disturbances or disorders have been reported in up to 40-90% of patients with IA [1-3]. Sleep disturbances are further associated with pain, fatigue, mental well-being and disease activity [4]. As chronic us of hypnotic drugs are associated with tolerance and side effects, there is growing interest in non-pharmacological management to improve sleep.

Objectives:

With a systematic review and meta-analysis, our primary objective was to evaluate the evidence of non-pharmacological interventions targeting sleep in patients with IA. Primary outcome was sleep domains, while secondary objectives were based on the core outcome domains for IA trials and harms.

Methods:

Following protocol closure, a systematic search was undertaken in MEDLINE, CENTRAL, PsycINFO, CINAHL, ClinicalTrials.gov, ACR and EULAR in September 2020. Eligible studies were randomised trials with adults with IA and concomitant sleep disturbances or disorders, comparing a non-pharmacological intervention targeting sleep disturbances or disorders to another non-pharmacological intervention, a pharmacological intervention or standard care. Screening of titles, abstracts, and subsequent full text assessment were conducted independently by two reviewers using the Covidence tool. Randomisation, blinding, and adequacy of analyses was assessed using the Cochrane’s RoB tool and the overall quality of evidence was rated using GRADE methodology. Disagreements were resolved at consensus meetings with last authors. Effect sizes for continuous outcomes were based on the standardised mean difference (SMD), combined using standard random-effects meta-analysis (all with 95% CIs).

Results:

Six trials (308 patients) were included in the quantitative synthesis. Two trials included patients with the sleep disorder insomnia and the remaining four trials included patients with sleep disturbances. Sleep domains were measured with Pittsburgh Sleep Quality Index (PSQI) or Insomnia Severity index (ISI). Three trials reported improvement on sleep following foot reflexology, auricular plaster therapy, and exercise. The overall meta-analysis presented in the figure of forest plot for self-reported sleep suggests that non-pharmacological interventions have a potentially large effect size of -0.80 (95% CI, -1.33 to -0.28) on sleep. However, the quality of the evidence was assessed as corresponding to low, given that the body of the evidence was rated down twice, due to serious study limitations and inconsistency.

Conclusion:

Although the effect of non-pharmacological interventions targeting sleep disturbances or the sleep disorder insomnia was statistically highly significant, the implication for clinical practice is questionable because of the overall quality evidence. None of the core outcomes used in contemporary IA trials have indicated clinical benefit in favour of non-pharmacological interventions targeting sleep disturbances or disorders.

In conclusion, more rigorous research on non-pharmacological management of sleep disturbances and disorders is urgently needed, also aimed at specific sleep disorders, in order to fully reveal the clinical utility of these novel treatment options. At this point, non-pharmacological treatment of sleep disturbances or disorders is promising and potentially highly effective, and may have the potential to persistently decrease the symptom burden and increase the quality of life of patients with IA.

References:

[1]Li et al., Psychol Health Med. 2019 Sep;24(8):911-924

[2]Haugeberg et al., Arthritis Res Ther. 2020 Aug 26;22(1):198

[3]Wali et al., J Clin Sleep Med. 2020 Feb 15;16(2):259-265

[4]Løppenthin et al., Clin Rheumatol. 2015 Dec;34(12):2029-39

Disclosure of Interests:

Kristine Marie Latocha: None declared, Katrine Løppenthin: None declared, Safa Al-Bazy: None declared, Tannie Albrechtsen: None declared, Helle Jensen: None declared, Mikkel Østergaard Speakers bureau: Abbvie, Celgene, Eli-Lilly, Janssen, Novartis, Pfizer, Roche, Sanofi and UCB, Consultant of: Abbvie, BMS, Boehringer-Ingelheim, Celgene, Eli-Lilly, Hospira, Janssen, Merck, Novartis, Novo, Orion, Pfizer, Regeneron, Roche, Sandoz, Sanofi and UCB, Grant/research support from: Abbvie, BMS, Merck, Celgene, Novartis, Poul Jennum: None declared, Bente Appel Esbensen: None declared, Robin Christensen: None declared

Microfluidics and the quantification of biomolecular interactions

Microfluidic systems under laminar flow conditions provide in-solution information about species size and binding affinities at very modest sample costs. Flow-induced dispersion analysis directly measures the spread of the analyte profile using Taylor dispersion analysis, whereas microfluidic diffusional sizing quantifies the transfer of analyte from one phase to another. Species of sizes between 0.5 and 1000 nm can be analyzed, and different populations resolved. Both techniques also allow analysis in complex media and medium throughput analysis. These properties make them valuable complements to existing approaches to measure biomolecular interactions.

Size-based characterization of adalimumab and TNF-α interactions using flow induced dispersion analysis: assessment of avidity-stabilized multiple bound species

The understanding and characterization of protein interactions is crucial for elucidation of complicated biomolecular processes as well as for the development of new biopharmaceutical therapies. Often, protein interactions involve multiple binding, avidity, oligomerization, and are dependent on the local environment. Current analytical methodologies are unable to provide a detailed mechanistic characterization considering all these parameters, since they often rely on surface immobilization, cannot measure under biorelevant conditions, or do not feature a structurally-related readout for indicating formation of multiple bound species. In this work, we report the use of flow induced dispersion analysis (FIDA) for in-solution characterization of complex protein interactions under in vivo like conditions. FIDA is an immobilization-free ligand binding methodology employing Taylor dispersion analysis for measuring the hydrodynamic radius (size) of biomolecular complexes. Here, the FIDA technology is utilized for a size-based characterization of the interaction between TNF-α and adalimumab. We report concentration-dependent complex sizes, binding affinities (K_d), kinetics, and higher order stoichiometries, thus providing essential information on the TNF-α–adalimumab binding mechanism. Furthermore, it is shown that the avidity stabilized complexes involving formation of multiple non-covalent bonds are formed on a longer timescale than the primary complexes formed in a simple 1 to 1 binding event.

Low potential for evolutionary rescue from climate change in a tropical fish

Climate change is increasing global temperatures and intensifying the frequency and severity of extreme heat waves. How organisms will cope with these changes depends on their inherent thermal tolerance, acclimation capacity, and ability for evolutionary adaptation. Yet, the potential for adaptation of upper thermal tolerance in vertebrates is largely unknown. We artificially selected offspring from wild-caught zebrafish (Danio rerio) to increase (Up-selected) or decrease (Down-selected) upper thermal tolerance over six generations. Selection to increase upper thermal tolerance was also performed on warm-acclimated fish to test whether plasticity in the form of inducible warm tolerance also evolved. Upper thermal tolerance responded to selection in the predicted directions. However, compared to the control lines, the response was stronger in the Down-selected than in the Up-selected lines in which evolution toward higher upper thermal tolerance was slow (0.04 ± 0.008 °C per generation). Furthermore, the scope for plasticity resulting from warm acclimation decreased in the Up-selected lines. These results suggest the existence of a hard limit in upper thermal tolerance. Considering the rate at which global temperatures are increasing, the observed rates of adaptation and the possible hard limit in upper thermal tolerance suggest a low potential for evolutionary rescue in tropical fish living at the edge of their thermal limits.

Towards functional characterization of excipients for oral solid dosage forms using UV-vis imaging. Liberation, release and dissolution

The purpose of this study was to investigate whole-dosage form UV-vis imaging as a potential tool for functional characterization of excipients used in solid oral dosage forms. To this end, tablets (average mass 260.0 mg, 224.5 mg and 222.1 mg) containing theophylline anhydrate (20 % w/w), 1% (w/w) magnesium stearate, and 79 % (w/w) of either microcrystalline cellulose (MCC, Avicel PH 101) or hydroxypropyl methylcellulose (HPMC, Methocel K15 M or K100 M) were prepared as model systems. Drug liberation from tablets was studied in 0.01 M HCl at 37 °C using a Sirius SDi2 equipped with a USP IV type flow cell comprising a UV-vis imaging detector operating at 255 nm and 520 nm. The effluent from the flow cell was passed through a downstream spectrophotometer, and UV-vis spectra in the wavelength range 200-800 nm were recorded every 2 min. The erosion and swelling behavior of the MCC tablets and HPMC K15 M and K100 M tablets were visualized in real time. The swelling of HPMC K15 M and K100 M containing tablets was assessed quantitatively as changes in tablet diameter measured at 520 nm, and was clearly distinguished from the swelling of the MCC tablets. Namely, an increment of 2.5 mm in diameter was determined for the HPMC tablets while the MCC tablets increased by 0.5-1 mm in diameter. Gel layers of variable thickness were observed only for the HPMC K15 M and K100 M tablets. In addition, a relatively high initial liberation rate of theophylline was found for the MCC tablets as compared to the HPMC tablets. UV-vis imaging revealed features of liberation not revealed by simply measuring drug concentration in the dissolution media or by visual assessment. It may be sufficiently sensitive to be further developed for functional characterization of excipients and provide insights into drug-excipient interactions likely to be useful in formulation development.

Effects and recovery of larvae of the cold-water coral Lophelia pertusa (Desmophyllum pertusum) exposed to suspended bentonite, barite and drill cuttings

Fossil fuel drilling operations create sediment plumes and release waste materials into the ocean. These operations sometimes occur close to sensitive marine ecosystems, such as cold-water corals. While there have been several studies on the effects of energy industry activities on adult corals, there is very little information on potential impacts to their early life history stages. Larval stages of many marine organisms, including cold-water corals use cilia as a means of feeding and swimming, and if these structures become clogged with suspended particulates, the larvae may sink and be lost to the system. The objective of this study was to understand the response of Lophelia pertusa larvae to a different drilling waste components, and assess post-exposure recovery. Larvae of two ages (eight and 21 days) were exposed to a range of concentrations of bentonite, barite and drill cuttings. Larval sensitivity was assessed using the concentration at which 50% of the larvae showed behavioral effects (EC₅₀) or lethal effects (LC₅₀). Larvae showed greatest sensitivity to bentonite, followed by barite and drill cuttings, and also showed age-related responses that differed among the test materials. Post exposure recovery was variable across materials, with larvae exposed to bentonite having the lowest recovery rates. Understanding the vulnerability of early life history stages to human activities can help inform management strategies to preserve reproductive capacity of important marine ecosystems.

In-Solution IgG Titer Determination in Fermentation Broth Using Affibodies and Flow-Induced Dispersion Analysis

Biopharmaceuticals such as protein and peptide-based drugs are often produced by fermentation processes where it is necessary to monitor the amount and quality of the product expressed during fermentation and for release testing of the final drug product. Standard procedures involve surface-based ligand binding technologies such as enzyme-linked immunosorbent assay and biolayer interferometry, or extensive purification using, e.g., preparative chromatography followed by spectrophotometric protein quantification. The multistep nature of these methodologies leads to lengthy protocols and renders real-time process control impractical. Recently, flow-induced dispersion analysis (FIDA) was introduced as a novel in-solution ligand binding technology, requiring only nano/microliter sample volumes. FIDA is based on Taylor dispersion analysis in narrow fused silica capillaries and provides the hydrodynamic radius of the binding ligand and complex in addition to the detailed binding characterization. Here, we demonstrate the use of FIDA for quantification of monoclonal IgG antibodies (rituximab) directly in mammalian cell fermentation broth with only 4 min of analysis time. The FIDA assay utilizes a small anti-IgG affibody, conjugated to a fluorophore, as a selective rituximab binder. The apparent change in the hydrodynamic radius of the affibody, as it interacts with known concentrations of rituximab, is used for generating a binding curve in a blank fermentation medium, and hence determining the dissociation constant and complex size. Finally, the binding curve is utilized for quantifying the rituximab titer concentration in clarified fermentation broth samples.

Electromembrane Extraction Using Sacrificial Electrodes

In this paper, we report the first example of employing a sacrificial electrode in the acceptor solution during electromembrane extraction (EME). The electrode was based on a silver wire with a layer of silver chloride electroplated onto the surface. During EME, the electrode effectively inhibited electrolysis of water in the acceptor compartment, by accepting the charge transfer across the SLM, which enabled the application of 500 μA current without suffering gas formation or pH changes from electrolysis of water. The electroplating strategy was optimized with a design-of-experiments (DOE) methodology that provided optimal conditions of electroplating. With an optimized electrode, 1 cm of the electrode in contact with the acceptor solution inhibited electrolysis of water for approximately 30 min at 500 μA current (redox capacity). Further, the redox capacity of the electrode was found to increase through multiple uses. The advantage of the electrode was demonstrated by extracting polar analytes at high-current conditions in a standard EME system comprising 2-nitrophenyl octyl ether (NPOE) as SLM and 10 mM HCl as sample/acceptor solutions. Application of high current enabled significantly higher recoveries than could otherwise be obtained at 100 μA. Sacrificial electrodes were also tested in μ-EME and were found beneficial by eliminating detrimental bubble formation. Thus, the sacrificial electrodes improved the stability of μ-EME systems. The findings of this paper are important for development of stable and robust systems for EME operated at high voltage/current and for EME performed in narrow channels/tubing where bubble formation is critical.

Towards in vitro in vivo correlation for modified release subcutaneously administered insulins

Therapeutic proteins and peptides are mainly administrated by subcutaneous injection. In vitro release testing of subcutaneous injectables performed using methods that take the structure and environment of the subcutaneous tissue into account may improve predictability of the in vivo behavior and thereby facilitate establishment of in vitro in vivo correlations. The aim of the study was to develop a biopredictive flow-through in vitro release method with a gel-type matrix for subcutaneously administered formulations and to explore the possibility of establishing a level A in vitro in vivo correlation for selected insulin products. A novel gel-based flow-through method with the incorporation of an injection step was used to assess selected commercial insulin formulations with different duration of action (Actrapid®, Mixtard® 30, Insulatard®, Lantus®). The in vitro release method provided the correct rank ordering in relation to the in vivo performance. For the modified release insulins Insulatard® and Lantus®, an in vitro in vivo correlation using non-linear time scaling was established based on the in vitro release data and in vivo subcutaneous absorption data of the ¹²⁵I-labeled insulins taken from literature. Predicted absorption profiles were constructed using the in vitro in vivo correlation and subsequently converted into simulated plasma profiles. The approach taken may be of wider utility in characterizing injectables for subcutaneous administration.

Medication Tracking: Design and Fabrication of a Dry Powder Inhaler with Integrated Acoustic Element by 3D Printing

PURPOSE

Asthma is a prevalent lung disorder that cause heavy burdens globally. Inhalation medicaments can relieve symptoms, improve lung function and, thus, the quality of life. However, it is well-documented that patients often do not get the prescribed dose out of an inhaler and the deposition of drug is suboptimal, due to incorrect handling of the device and wrong inhalation technique. This study aims to design and fabricate an acoustic dry powder inhaler (ADPI) for monitoring inhalation flow and related drug administration in order to evaluate whether the patient receives the complete dose out of the inhaler.

METHODS

The devices were fabricated using 3D printing and the impact of the acoustic element geometry and printing resolution on the acoustic signal was investigated. Commercial Foradil (formoterol fumarate) capsules were used to validate the availability of the ADPI for medication dose tracking. The acoustic signal was analysed with Partial-Least-Squares (PLS) regression.

RESULTS

Indicate that specific acoustic signals could be generated at different air flow rates using a passive acoustic element with specific design features. This acoustic signal could be correlated with the PLS model to the air flow rate. A more distinct sound spectra could be acquired at higher printing resolution. The sound spectra from the ADPI with no capsule, a full capsule and an empty capsule are different which could be used for medication tracking.

CONCLUSIONS

This study shows that it is possible to evaluate the medication quality of inhaled medicaments by monitoring the acoustic signal generated during the inhalation process.

Electromembrane extraction of sodium dodecyl sulfate from highly concentrated solutions

This fundamental work investigated the removal of sodium dodecyl sulfate (SDS) from highly concentrated samples by electromembrane extraction (EME).

Nursing teamwork in the care of older people: A mixed methods study

Healthcare is increasingly complex and requires the ability to adapt to changing demands. Teamwork is essential to delivering high quality care and is central to nursing. The aims of this study were to identify the processes that underpin nursing teamwork and how these affect the care of older people, identify the relationship between perceived teamwork and perceived quality of care, and explore in depth the experience of working in nursing teams. The study was carried out in three older people's wards in a London teaching hospital. Nurses and healthcare assistants completed questionnaires (n = 65) on known dynamics of teamwork (using the Nursing Teamwork Survey) together with ratings of organisational quality (using an adapted AHRQ HSPS scale). A sample (n = 22; 34%) was then interviewed about their perceptions of care, teamwork and how good outcomes are delivered in everyday work. Results showed that many care difficulties were routinely encountered, and confirmed the importance of teamwork (e.g. shared mental models of tasks and team roles and responsibilities, supported by leadership) in adapting to challenges. Perceived quality of teamwork was positively related to perceived quality of care. Work system variability and the external environment influenced teamwork, and confirmed the importance of team adaptive capacity. The CARE model shows the centrality of teamwork in adapting to variable demand and capacity to deliver care processes, and the influence of broader system factors on teamworking.

P2844Novel temperature guided irrigated ablation catheter: reproducibility of procedural efficiencies and acute success to isolate the pulmonary veins from two multicenter, feasibility studies

Background/Introduction

The novel catheter with 6 thermocouples for real-time temperature monitoring during irrigated radiofrequency ablation was designed to potentially enhance safety and effectiveness of the Smart Touch Surround Flow (STSF) catheter by incorporating real-time temperature sensing. A supplementary, novel algorithm was developed to modulate power to maintain target temperature during high power/short duration ablation (90W, 4s).

Purpose

This sub-analysis was performed to examine consistency and reproducibility of the procedural efficiencies and acute success of the novel catheter with optimized temperature control and microelectrodes in treating paroxysmal atrial fibrillation (PAF) across multiple sites from two initial feasibility studies, in standard (QMODE) and high power/short duration (QMODE+) temperature-control ablation modes.

Methods

The QDOT-MICRO (QMODE, NCT02944968; N=42) and QDOT-FAST (QMODE+, NCT03459196; N=52) studies were both prospective, non-randomized multi-center, clinical investigations completed across 6 and 7 centers, respectively, in Europe. Procedural efficiencies and acute success (PVI via entrance block) was examined across sites within the study.

Results

In the QDOT-MICRO study, median procedure time (105–155 min), RF ablation time (27.7–39.5 min), and fluoroscopy times (2.2–8 min) during QMODE ablation were similar across the 6 sites. In QMODE+ ablation, median procedure time, RF ablation time, and fluoroscopy times all fall within (84–134 min), (4.8–9.7 min) and (1.1–9.6 min), respectively, across the 7 sites. Fluid delivery by the study catheter was low in both studies: QDOT-MICRO 547±278mL (mean ± SD); QDOT-FAST 382±299. mL (mean ± SD); which is 39.1 and 57.4% lower, respectively, than reported in the SMART SF trial. Esophageal temperature probe was used in the majority of patients (30/42 for QDOT MICRO and 51/52 for QDOT-FAST). Acute PVI was successful in 100% of patients in both studies with no deaths or unanticipated AEs.

Conclusion(s)

In both feasibility studies, procedural efficiencies were reproducible across study sites in both QMODE and QMODE+, with 100% acute success and good safety outcomes. Efficiencies are likely to improve with further experience. These results need to be confirmed in larger trials.

Acknowledgement/Funding

Both Studies are Company Sponsored Studies funded by Biosense Webster, Inc.

Long-term outcomes after high-dose chemoradiotherapy for non-surgical management of distal rectal cancer

3611

Background: Surgery is standard treatment for rectal cancer, but neoadjuvant chemoradiotherapy (CRT) may result in clinical complete response (cCR) in selected patients, allowing for non-surgical management (NSM). Prospective studies of NSM strategies are sparse however, and long-term data on quality of life (QoL) are limited. We conducted a single-arm phase II trial of high-dose CRT for NSM of distal rectal cancer; we report secondary long-term patient-reported outcomes (PROs), local regrowth and overall survival (OS) in patients managed non-surgically. Methods: Fifty-one patients with resectable, T2 or T3, N0–N1, low adenocarcinoma received 65Gy (IMRT, brachytherapy boost) and oral tegafur-uracil. Patients with cCR 6 weeks after treatment (clinical examination, MRI, biopsy) were referred for observation, and followed closely with clinical examinations, endoscopies, PET-CTs, and PROs for 5 years. Overall colorectal cancer specific QoL and specific symptom scores were compared between timepoints using paired Wilcoxon tests. Local regrowth was estimated using cumulative incidence; overall survival using Kaplan-Meier estimates. Results: Forty patients achieved cCR after treatment; 28 were in follow-up at 24m, 21 at 36m, 18 at 60m. Patients left the trial due to local tumor regrowth (n=12), distant metastases (n=3), new primary cancers (n=6) and loss to follow-up (n=1). Average QoL score did not differ between baseline (median 11.1) and 24m (13.7), 48m (11.1,) or 60m (6.9). See Table for individual scores; only rectal bleeding deteriorated from baseline (significantly worse at 24m). At median follow-up of 5.0 years, local regrowth rate and OS were 31% (95 CI 15%-47%) and 85% (95 CI 75%-97%), respectively. Conclusions: Long term follow-up after NSM of early rectal cancer showed excellent general colorectal cancer QoL and local symptom scores. (NCT00952926). EORTC QLQ – CR 29. Proportion reporting ‘quite a bit’ or ‘very much’ on symptom scales. Clinical trial information: NCT00952926. [Table: see text]

Animal models with group-specific additive genetic variances: extending genetic group models

BACKGROUND

The animal model is a key tool in quantitative genetics and has been used extensively to estimate fundamental parameters, such as additive genetic variance or heritability. An implicit assumption of animal models is that all founder individuals derive from a single population. This assumption is commonly violated, for instance in crossbred livestock or when a meta-population is split into genetically differentiated subpopulations. Ignoring that base populations are genetically heterogeneous and thus split into different 'genetic groups' may lead to biased parameter estimates, especially for additive genetic variance. To avoid such biases, genetic group animal models, which account for the presence of more than one genetic group, have been proposed. Unfortunately, the method to date is only computationally feasible when the breeding values of the groups are allowed to differ in their means, but not in their variances.

RESULTS

We present an extension of the animal model that permits estimation of group-specific additive genetic variances. This is achieved by employing group-specific relatedness matrices for the breeding value components to different genetic groups. We derive these matrices by decomposing the full relatedness matrix via the generalized Cholesky decomposition, and by scaling the respective matrix components for each group. We propose a computationally convenient approximation for the matrix component that encodes for the Mendelian sampling variance, and show that this approximation is not critical. In addition, we explain why segregation variances are often negligible when analyzing the complex polygenic traits that are frequently the focus of evolutionary ecologists and animal breeders. Simulations and an example from an insular meta-population of house sparrows in Norway with three distinct genetic groups illustrate that the method is successful in estimating group-specific additive genetic variances, and that segregation variances are indeed negligible in the empirical example.

CONCLUSIONS

Quantifying differences in additive genetic variance within and among populations is of major biological interest in ecology, evolution, and animal and plant breeding. The proposed method allows to estimate such differences for subpopulations that form a connected set of populations, and may thus also be useful to study temporal or spatial variation of additive genetic variances.

Signs of adaptation to trace metal contamination in a common urban bird

Metals and metalloids at elevated concentrations can be toxic to both humans and wildlife. In particular, lead exposure can act as a stressor to wildlife and cause negative effects on fitness. Any ability to adapt to stress caused by the negative effects of trace metal exposure would be beneficial for species living in contaminated environments. However, mechanisms for responding adaptively to metal contamination are not fully understood in free-living organisms. The Australian populations of the house sparrow (Passer domesticus) provides an excellent opportunity to study potential adaptation to environmental lead contamination because they have a commensal relationship with humans and are distributed broadly across Australian settlements including many long-term mining and smelting communities. To examine the potential for an evolutionary response to long-term lead exposure, we collected genomic SNP data using the house sparrow 200 K SNP array, from 11 localities across the Australian distribution including two mining sites (Broken Hill and Mount Isa, which are two genetically independent populations) that have well-established elevated levels of lead contamination as well as trace metals and metalloids. We contrast these known contaminated locations to other lesser-contaminated environments. Using an ecological association genome scan method to identify genomic differentiation associated with estimates of lead contamination we identified 60 outlier loci across three tests. A total of 39 genes were found to be physically linked (within 20 kbps) of all outliers in the house sparrow reference genome. The linked candidate genes included 12 genes relevant to lead exposure, such as two metal transporters that can transport metals including lead and zinc across cell membranes. These candidate genes provide targets for follow up experiments comparing resilience to lead exposure between populations exposed to varied levels of lead contamination.

Flow-Induced Dispersion Analysis (FIDA) for Protein Quantification and Characterization

Flow-Induced Dispersion Analysis (FIDA) enables characterization and quantification of proteins under native conditions. FIDA is based on measuring the change in size of a ligand as it selectively interacts with the target protein. The unbound ligand has a relatively small apparent hydrodynamic radius (size), which increase in the presence of the analyte due to binding to the analyte. The K_d of the interaction may be obtained in a titration experiment and the measurement of the apparent ligand size in an unknown sample forms the basis for determining the analyte concentration. The apparent molecular size is measured by Taylor dispersion analysis (TDA) in fused silica capillary capillaries. FIDA is a "ligand-binding" assay and has therefore certain features in common with Enzyme-Linked Immunosorbent Assay (ELISA), Surface Plasmon Resonance (SPR), and Biolayer Interferometry (BLI) based techniques. However, FIDA probes a single in-solution binding event and thus makes assay development straightforward, and the absolute size measurement enables built-in assay quality control. Further, as FIDA does not involve surface chemistries, complications related to nonspecific adsorption of analyte and assay components are minimized enabling direct measurement in, e.g., plasma and serum.