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The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural–geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status.
Communicating a pension product well is as important as optimising the financial value. In a recent study, we showed that up to 80% of the value of a pension lump sum could be lost if customer communication failed. In this paper, we extend the simple customer interaction of the earlier contribution to the more challenging lifetime annuity case. Using a simple mobile phone device, the pension customer can select the life-long optimal investment strategy within minutes. The financial risk trade-off is presented as a trade-off between the pension paid and the number of years the life-long annuity is guaranteed. The pension payment decreases when investment security increases. The necessary underlying mathematical financial hedging theory is included in the study.
In vitro maintenance of helminth parasites enables a variety of molecular, pharmaceutical and immunological analyses. Currently, the nutritional and environmental in vitro requirements of the equine ascarid parasite, Parascaris spp., have not been determined. Additionally, an objective method for assessing viability of Parascaris spp. intestinal stages does not exist. The purpose of this study was to ascertain the in vitro requirements of intestinal stages of Parascaris spp., and to develop a viability assessment method. A total of 1045 worms were maintained in a total of 212 cultures. Worms obtained from naturally infected foals at necropsy were immediately placed in culture flasks containing 200 mL of culture media. A variety of media types, nutrient supplementation and environmental conditions were examined. A motility-based scoring system was used to assess worm viability. Worms maintained in Roswell Park Memorial Institute-1640 had significantly better viability than any other media (P < 0.0001) and all media types supplemented with any of the nutrients examined (P < 0.0001). The use of a platform rocker also significantly improved viability (P = 0.0305). This is the first study to examine the requirements for maintaining Parascaris spp. intestinal stages in vitro and to evaluate their viability based on movement using an objective scoring system.
The growth of gut anaerobic fungi is usually determined in batch culture by gravimetric measurements of dry-matter (DM) loss, or by quantification of fermentation end-products (Lowe et al., 1987). These techniques involve destructive sampling of the cultures and require many replicate cultures in time-course experiments. Moreover, techniques using DM loss are only able to measure the end-point of degradation of substrate and cannot follow the growth over the entire fermentation period. Using a pressure transducer, Theodorou et al. (1994) developed a simple and sensitive gas production procedure to determine the fermentation kinetics of ruminant foods. This procedure can also be used to follow the growth of anaerobic fungi on soluble and particulate substrate in batch cultures Theodorou et al. (1995).
Size, or its commonly used proxy live weight, is a necessary input when calculating the energy requirements of an animal. It is also a major factor in determining the intake capacity of an animal. The sole use of live weight as a determinant of size incorporates the implicit assumption that body fat and body protein mass are equivalent for the purposes of calculating energy requirements and intake capacity. Recent evidence indicates that this is not so in either case (Birnie et al., 2000; Friggens et al., 1998). The use of live weight may be acceptable where it can be reasonably assumed that there is a stable relationship between body fat and protein. However, when making breed or parity comparisons there is no reason to assume a stable relationship between body fat and protein. Meaningful comparisons can be made if live weights can be adjusted for differences in body fat content. In the applied context this means adjusting to a standard body condition score. This study provided the opportunity to examine the relationships between condition score and live weight in three breeds across three parities.
Berseem clover (Trifolium alexandrinum L.) is an important forage legume and is the primary winter forage crop in Pakistan. There are significant gaps in yield potential among varieties of berseem clover, as well as yields obtained at research stations and on-farm. To address this problem a survey of farmers was undertaken in the districts of Kasur and Okara, Punjab, Pakistan to determine the level of knowledge and understanding of berseem forage cultivation and seed production. The study comprised 44% smallholder (<3 ha), 26% medium (3–5 ha) and 30% large farmers (>5 ha) with average age of 42 years. Most farmers had little or no knowledge of the role of seed quality, inoculation with rhizobium, pollination, fertiliser use, irrigation management and the importance of forage nutritional value in improving livestock productivity. Most farmers (56%) had received no input from the government or private sector to improve forage production, relying instead on traditional knowledge. Knowledge of the importance of land preparation (95%), sowing rate (98%) and insect and pest management (75%) was higher than seed selection and fertilisation. Adoption of improved varieties (3%) and production technologies (14%) was low due to various constraints including ignorance, high cost of inputs, lack of availability of inputs in the market and a perceived high level of financial risk. Almost 100% of the respondents agreed that seed of improved varieties was a pre-requisite for higher forage and seed production as well as essential to start village-based forage seed enterprises.
The postpartum period is well-known risk period for the first onset of autoimmune thyroid disorders (AITDs) as well as first onset of psychiatric disorders. These two disorders are some of the most prevalent medical conditions postpartum, often misdiagnosed and disabling if left untreated. Our study was designed to explore the possible bidirectional association between AITDs and psychiatric disorders during the postpartum period.
A population-based cohort study through linkage of Danish national registers, which comprised 312 779 women who gave birth to their first child during 1997–2010. We conducted Poisson regression analysis to estimate the incidence rate ratio (IRR) of psychiatric disorders among women with first-onset AITDs, the IRR of AITDs among women with first-onset psychiatric disorders as well as the overlap between these disorders using a comorbidity index.
Women with first-onset AITDs postpartum were more likely to have first-onset psychiatric disorders than women who did not have postpartum AITDs (IRR = 1.88, 95% confidence interval (CI): 1.25–2.81). Women with first-onset postpartum psychiatric disorders had a higher risk of AITDs than women with no psychiatric disorders (IRR = 2.16, 95% CI: 1.45–3.20). The comorbidity index 2 years after delivery was 2.26 (95% CI: 1.61–2.90), indicating a comorbidity between first-onset AITDs and psychiatric disorders.
First-onset AITDs and psychiatric disorders co-occur in the postpartum period, which has relevance to further studies on the etiologies of these disorders and why childbirth in particular triggers the onset.
The spread of African swine fever virus (ASFV) threatens to reach further parts of Europe. In countries with a large swine production, an outbreak of ASF may result in devastating economic consequences for the swine industry. Simulation models can assist decision makers setting up contingency plans. This creates a need for estimation of parameters. This study presents a new analysis of a previously published study. A full likelihood framework is presented including the impact of model assumptions on the estimated transmission parameters. As animals were only tested every other day, an interpretation was introduced to cover the weighted infectiousness on unobserved days for the individual animals (WIU). Based on our model and the set of assumptions, the within- and between-pen transmission parameters were estimated to βw = 1·05 (95% CI 0·62–1·72), βb = 0·46 (95% CI 0·17–1·00), respectively, and the WIU = 1·00 (95% CI 0–1). Furthermore, we simulated the spread of ASFV within a pig house using a modified SEIR-model to establish the time from infection of one animal until ASFV is detected in the herd. Based on a chosen detection limit of 2·55% equivalent to 10 dead pigs out of 360, the disease would be detected 13–19 days after introduction.
The surveillance of Clostridium difficile (CD) in Denmark consists of laboratory based data from Departments of Clinical Microbiology (DCMs) sent to the National Registry of Enteric Pathogens (NREP). We validated a new surveillance system for CD based on the Danish Microbiology Database (MiBa). MiBa automatically collects microbiological test results from all Danish DCMs. We built an algorithm to identify positive test results for CD recorded in MiBa. A CD case was defined as a person with a positive culture for CD or PCR detection of toxin A and/or B and/or binary toxin. We compared CD cases identified through the MiBa-based surveillance with those reported to NREP and locally in five DCMs representing different Danish regions. During 2010–2014, NREP reported 13 896 CD cases, and the MiBa-based surveillance 21 252 CD cases. There was a 99·9% concordance between the local datasets and the MiBa-based surveillance. Surveillance based on MiBa was superior to the current surveillance system, and the findings show that the number of CD cases in Denmark hitherto has been under-reported. There were only minor differences between local data and the MiBa-based surveillance, showing the completeness and validity of CD data in MiBa. This nationwide electronic system can greatly strengthen surveillance and research in various applications.
Adverse psychosocial working environments characterized by job strain (the combination of high demands and low control at work) are associated with an increased risk of depressive symptoms among employees, but evidence on clinically diagnosed depression is scarce. We examined job strain as a risk factor for clinical depression.
We identified published cohort studies from a systematic literature search in PubMed and PsycNET and obtained 14 cohort studies with unpublished individual-level data from the Individual-Participant-Data Meta-analysis in Working Populations (IPD-Work) Consortium. Summary estimates of the association were obtained using random-effects models. Individual-level data analyses were based on a pre-published study protocol.
We included six published studies with a total of 27 461 individuals and 914 incident cases of clinical depression. From unpublished datasets we included 120 221 individuals and 982 first episodes of hospital-treated clinical depression. Job strain was associated with an increased risk of clinical depression in both published [relative risk (RR) = 1.77, 95% confidence interval (CI) 1.47–2.13] and unpublished datasets (RR = 1.27, 95% CI 1.04–1.55). Further individual participant analyses showed a similar association across sociodemographic subgroups and after excluding individuals with baseline somatic disease. The association was unchanged when excluding individuals with baseline depressive symptoms (RR = 1.25, 95% CI 0.94–1.65), but attenuated on adjustment for a continuous depressive symptoms score (RR = 1.03, 95% CI 0.81–1.32).
Job strain may precipitate clinical depression among employees. Future intervention studies should test whether job strain is a modifiable risk factor for depression.
Late-summer subglacial water pressures have been measured in a dense array of boreholes in the ablation area of Haut Glacier d’Arolla, Switzerland. Interpolated surfaces of minimum diurnal water pressure and diurnal water-pressure variation suggest the presence of a subglacial channel within a more widespread, distributed drainage system. The channel flows along the centre of a variable pressure axis (VPA), some tens of metres wide, that is characterized by low minimum diurnal water pressures (frequently atmospheric) and high diurnal water-pressure variations. These characteristics are transitional over a lateral distance of c. 70 m to higher and more stable subglacial water pressures in the adjacent distributed system. Water-pressure variations recorded in boreholes located close to the centre of the VPA reflect the delivery of surface-derived meltwater to the glacier bed and result in a diurnally reversing, transverse hydraulic gradient that drives water out from the channel into the distributed system during the afternoon and back to the channel overnight. Subglacial observations suggest that such flow occurs through a vertically confined sediment layer. Borehole turbidity records indicate that the resulting diurnal water flows are responsible for the mobilization and transport of fine debris in suspension. Analysis of the propagation velocity and amplitude attenuation cf the diurnal pressure waves suggests that the hydraulic conductivity of the sediment layer decreases exponentially with distance from the channel, falling from c. 10−4 m s−1 at the channel boundary to c. 10−7 m s−1 70 m away. These apparent hydraulic conductivities are consistent with Darcian flow through clean sand and typical glacial till, respectively.
We suggest that fine material is systematically flushed from basal sediments located adjacent to large, melt-season drainage channels beneath warm-based glaciers. This process may have important implications for patterns of glacier erosion, hydro-chemistry and dynamics.
Psychosocial therapy after deliberate self-harm might be associated with reduced risk of specific causes of death.
In this matched cohort study, we included patients, who after an episode of deliberate self-harm received psychosocial therapy at a Suicide Prevention Clinic in Denmark between 1992 and 2010. We used propensity score matching in a 1:3 ratio to select a comparison group from 59 046 individuals who received standard care. National Danish registers supplied data on specific causes of death over a 20-year follow-up period.
At the end of follow-up, 391 (6.9%) of 5678 patients in the psychosocial therapy group had died, compared with 1736 (10.2%) of 17 034 patients in the matched comparison group. Lower odds ratios of dying by mental or behavioural disorders [0.54, 95% confidence interval (CI) 0.37–0.79], alcohol-related causes (0.63, 95% CI 0.50–0.80) and other diseases and medical conditions (0.61, 95% CI 0.49–0.77) were noted in the psychosocial therapy group. Also, we found a reduced risk of dying by suicide as well as other external causes, however, not by neoplasms and circulatory system diseases. Numbers needed to treat were 212.9 (95% CI 139.5–448.4) for mental or behavioural disorders as a cause of death, 111.1 (95% CI 79.2–210.5) for alcohol-related causes and 96.8 (95% CI 69.1–161.8) for other diseases and medical conditions.
Our findings indicate that psychosocial therapy after deliberate self-harm might reduce long-term risk of death from select medical conditions and external causes. These promising results should be tested in a randomized design.
Chemical and isotopic analyses have been made of pigment samples from two separate rock art sites in Argentina. The purpose of the study has been to establish the feasibility of extracting carbonaceous material from the samples which will permit reliable radiocarbon dates for the time of painting. The two sites, Catamarca and Rio Negro, present quite different problems. Most of the paper is concerned with Catamarca, and here we have shown that the paint pigments contain very little or no organic binder; but they do contain calcium oxalate derived from local cacti, and calcium carbonate derived probably from local plant ash. We describe a method to purify carbon extracted from the calcium oxalate, and present the dates obtained on both components. We show that, though rare, natural deposits containing both calcium oxalate and calcite do occur, but that they are very distinct in both 13C and 14C compositions; and we argue that they are very unlikely to contaminate the pigments to such an extent that the 14C dates are altered. For the Rio Negro site we show that the ground for the paint pigments contains carbon derived from fires burnt inside the cave, and discuss how analytical methods provide information to develop a strategy for extracting material, from both ground and pigment, for more reliable dating.
The higher spatial resolution and sensitivity of ISO allowed several extragalactic surveys to be extended to greater depth than obtained with IRAS. With the extended wavelength range deep surveys were performed for the first time at wavelengths up to ~ 200 μm. They favour galaxy models with strong evolution. With ISO's new capabilities the spectral energy distributions of larger samples of ULIRGs in the local universe and those of quasars and radio galaxies were determined. These data are applicable as templates to the more distant universe. Foreground components from zodiacal light and cirrus to the intracluster dust emission were studied in connection with their separation from the extragalactic background radiation.
Mutants of Bacillus subtilis can be developed to overproduce Val in vitro. It was hypothesized that addition of Bacillus subtilis mutants to pig diets can be a strategy to supply the animal with Val. The objective was to investigate the effect of Bacillus subtilis mutants on growth performance and blood amino acid (AA) concentrations when fed to piglets. Experiment 1 included 18 pigs (15.0±1.1 kg) fed one of three diets containing either 0.63 or 0.69 standardized ileal digestible (SID) Val : Lys, or 0.63 SID Val : Lys supplemented with a Bacillus subtilis mutant (mutant 1). Blood samples were obtained 0.5 h before feeding and at 1, 2, 3, 4, 5 and 6 h after feeding and analyzed for AAs. In Experiment 2, 80 piglets (9.1±1.1 kg) were fed one of four diets containing 0.63 or 0.67 SID Val : Lys, or 0.63 SID Val : Lys supplemented with another Bacillus subtilis mutant (mutant 2) or its parent wild type. Average daily feed intake, daily weight gain and feed conversion ratio were measured on days 7, 14 and 21. On day 17, blood samples were taken and analyzed for AAs. On days 24 to 26, six pigs from each dietary treatment were fitted with a permanent jugular vein catheter, and blood samples were taken for AA analysis 0.5 h before feeding and at 1, 2, 3, 4, 5 and 6 h after feeding. In experiment 1, Bacillus subtilis mutant 1 tended (P<0.10) to increase the plasma levels of Val at 2 and 3 h post-feeding, but this was not confirmed in Experiment 2. In Experiment 2, Bacillus subtilis mutant 2 and the wild type did not result in a growth performance different from the negative and positive controls. In conclusion, results obtained with the mutant strains of Bacillus subtilis were not better than results obtained with the wild-type strain, and for both strains, the results were not different than the negative control.
The relationship of the chain ladder method to mathematical statistics has long been debated in actuarial science. During the 1990s it became clear that the originally deterministic chain ladder can be seen as an autoregressive time series or as a multiplicative Poisson model. This paper draws on recent research and concludes that chain ladder can be seen as a structured histogram. This gives a direct link between classical aggregate methods and continuous granular methods. When the histogram is replaced by a smooth counterpart, we have a continuous chain ladder model. Re-inventing classical chain ladder via double chain ladder and its extensions introduces statistically solid approaches of combining paid and incurred data with direct link to granular data approaches. This paper goes through some of the extensions of double chain ladder and introduces new approaches to incorporating and modelling incurred data.
A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
Surveys with ISO (Kessler et al 1996), in particular with the CAM (Cesarsky et al 1996) and PHOT (Lemke et al 1996) instruments, will greatly extend our understanding of extra-galactic populations and their cosmological evolution. The main advantages that ISO surveys have over e.g IRAS are increased sensitivity/depth and wavelength coverage. Within the Guaranteed and Open Time programmes there are many field surveys which will efficiently map the limits in these parameters. In this talk I will briefly overview those surveys before concentrating in more detail on one survey in particular, the ISO survey of the Hubble Deep Field (HDF), to illustrate the kind of results that can be expected.
For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.
General introduction of rocky intertidal and salt marsh systems
The land–sea margin encompasses a variety of hard and soft-bottom habitats where organisms are exposed to a dynamic range of aquatic and atmospheric conditions dependent on a rhythm set by the tides. In this chapter, we focus on rocky intertidal and salt marsh ecosystems, which have been extensively studied on many continents. Both rocky shore and salt marsh communities exhibit strong and consistent patterns of intertidal zonation over relatively compressed spatial scales, making them excellent systems for understanding the context-dependency of species interactions. Hard-bottomed rocky intertidal communities are dominated by marine macroalgae and sessile marine invertebrates extending their reach to the furthest edge of the influence of sea spray, while soft-bottomed salt marsh communities are anchored by terrestrial plants with adaptations or tolerance to inundation by salty and brackish waters. Rocky shore communities may be battered by the full force of large ocean waves or gently lapped with seawater on more protected shorelines. In contrast, salt marshes are restricted to quiet waters where sediment accretion by plants is the main mechanism for habitat creation. Both communities may experience very large tidal excursions or only minimal ones, depending on the local dynamics of the tides, with corresponding consequences for the spatial extent of these communities across the shoreline. The steep environmental gradients and distinctive biological zonation patterns that characterize both rocky shore and salt marsh ecosystems (Fig. 7.1) have provided ecologists with accessible and highly tractable ecosystems for investigating the role of bottom-up and top-down factors along environmental gradients.
Bottom-up and top-down interactions in rocky intertidal systems
Introduction to rocky intertidal systems
Rocky intertidal communities have been the subject of intensive study world-wide, especially at temperate latitudes. The typically broad tidal range and relatively moderate atmospheric conditions create a wide zone of intertidal habitat that is generally hospitable to rocky intertidal species, while also readily accessible to investigators for hours at a time during periods of low tide and calm sea state.