Clostridium botulinum causes infant botulism by colonising the intestines and producing botulinum neurotoxin in situ. Previous reports have linked infant botulism cases to C. botulinum spores in household dust, yet the baseline incidence of C. botulinum spores in residential households is currently unknown. Vacuum cleaner dust from 963 households in 13 major Canadian cities was tested for C. botulinum using a novel real-time PCR assay directed against all known subtypes of the botulinum neurotoxin gene. None of the samples tested positive for C. botulinum. Analysis of a random subset of samples by MALDI Biotyper revealed that the most common anaerobic bacterial isolates were of the genus Clostridium and the most common species recovered overall was Clostridium perfringens. Dust that was spiked with C. botulinum spores of each toxin type successfully produced positive real-time PCR reactions. These control experiments indicate that this is a viable method for the detection of C. botulinum spores in household dust. We make several recommendations for future work that may help discover a common environmental source of C. botulinum spores that could lead to effective preventative measures for this rare but deadly childhood disease.

Artificial illumination is a fundamental human need. Burning wood and other materials usually in hearths and fireplaces extended daylight hours, whilst the use of flammable substances in torches offered light on the move. It is increasingly understood that pottery played a role in light production. In this study, we focus on ceramic oval bowls, made and used primarily by hunter-gatherer-fishers of the circum-Baltic over a c. 2000 year period beginning in the mid-6th millennium cal bc. Oval bowls commonly occur alongside larger (cooking) vessels. Their function as ‘oil lamps’ for illumination has been proposed on many occasions but only limited direct evidence has been secured to test this functional association. This study presents the results of molecular and isotopic analysis of preserved organic residues obtained from 115 oval bowls from 25 archaeological sites representing a wide range of environmental settings. Our findings confirm that the oval bowls of the circum-Baltic were used primarily for burning fats and oils, predominantly for the purposes of illumination. The fats derive from the tissues of marine, freshwater, and terrestrial organisms. Bulk isotope data of charred surface deposits show a consistently different pattern of use when oval bowls are compared to other pottery vessels within the same assemblage. It is suggested that hunter-gatherer-fishers around the 55th parallel commonly deployed material culture for artificial light production but the evidence is restricted to times and places where more durable technologies were employed, including the circum-Baltic.

The inaugural data from the first systematic program of sea-ice observations in Kotzebue Sound, Alaska, in 2018 coincided with the first winter in living memory when the Sound was not choked with ice. The following winter of 2018–19 was even warmer and characterized by even less ice. Here we discuss the mass balance of landfast ice near Kotzebue (Qikiqtaġruk) during these two anomalously warm winters. We use in situ observations and a 1-D thermodynamic model to address three research questions developed in partnership with an Indigenous Advisory Council. In doing so, we improve our understanding of connections between landfast ice mass balance, marine mammals and subsistence hunting. Specifically, we show: (i) ice growth stopped unusually early due to strong vertical ocean heat flux, which also likely contributed to early start to bearded seal hunting; (ii) unusually thin ice contributed to widespread surface flooding. The associated snow ice formation partly offset the reduced ice growth, but the flooding likely had a negative impact on ringed seal habitat; (iii) sea ice near Kotzebue during the winters of 2017–18 and 2018–19 was likely the thinnest since at least 1945, driven by a combination of warm air temperatures and a persistent ocean heat flux.

The first demonstration of laser action in ruby was made in 1960 by T. H. Maiman of Hughes Research Laboratories, USA. Many laboratories worldwide began the search for lasers using different materials, operating at different wavelengths. In the UK, academia, industry and the central laboratories took up the challenge from the earliest days to develop these systems for a broad range of applications. This historical review looks at the contribution the UK has made to the advancement of the technology, the development of systems and components and their exploitation over the last 60 years.

Primates are one of the most threatened groups of mammals. Understanding their patterns of population occurrence and abundance, especially in response to threats, is critical for informing conservation action. The crested black macaque Macaca nigra is the only Critically Endangered species of Sulawesi's seven endemic macaques. Little is known about its distribution or its response to deforestation and hunting. We conducted a camera-trap survey across the entire species range using an occupancy-based analytical approach to (1) establish the first range-wide baseline of occurrence, (2) investigate how environmental and anthropogenic factors influence occurrence, (3) identify priority conservation subpopulations, and (4) test the efficacy of the sampling and analytical protocol for temporal monitoring of M. nigra using occupancy as the state variable. From 9,753 camera-trap days, M. nigra was detected on 473 days at 77 of the 111 camera locations. Species occupancy was 0.66 and highest inside protected areas and closed canopy forest. We identified eight distinct subpopulations, based on distribution and forest fragment size. To inform future monitoring, we used a power analysis to determine if our effort would allow us to detect inter-annual occupancy declines of 10%, and found that 90 camera locations surveyed for 3 months (8,100 camera days) across three consecutive seasons is the effort required to detect such change with 80% certainty. Our study underscores the importance of well-managed protected areas and intact forests for the long-term survival of the crested black macaque, and tests the effectiveness of camera traps to monitor primates at the landscape scale.

Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.

Slave traders forced more than 1.65 million captive Africans aboard illegal transatlantic slave ships during the nineteenth century. This article focuses on the final phase of this brutal traffic, between 1850 and 1866. It argues that slave traders sustained their illicit industry, in large part, by strategically coordinating their financial arrangements against a rising tide of international suppression. One key tactic was for slave trade investors in the United States, Cuba, Africa, and Iberia to lower the risks of interdiction by joining forces and co-financing voyages. Another was to combine with an international cast of merchants and bankers, who helped them launder slave trade capital and transmit it to their distant allies. This capital was concealed within broader currents of global commerce, which was, in turn, spurred by the growth of free trade in the nineteenth century. These myriad alliances and capital flows undergirded the trade until its final extinction in the 1860s.

An imperfect competition model of the U.S. milk market is developed for analyzing the impacts of dairy policy deregulation. Estimated degree-of-competition parameters indicate that the U.S. milk market has become more competitive over time. The usefulness of the model is demonstrated by showing the relative differences of dynamic simulation results of the imperfect competition model with the results of a conventional exogenous fluid differential model.

Approximately half of the variation in wellbeing measures overlaps with variation in personality traits. Studies of non-human primate pedigrees and human twins suggest that this is due to common genetic influences. We tested whether personality polygenic scores for the NEO Five-Factor Inventory (NEO-FFI) domains and for item response theory (IRT) derived extraversion and neuroticism scores predict variance in wellbeing measures. Polygenic scores were based on published genome-wide association (GWA) results in over 17,000 individuals for the NEO-FFI and in over 63,000 for the IRT extraversion and neuroticism traits. The NEO-FFI polygenic scores were used to predict life satisfaction in 7 cohorts, positive affect in 12 cohorts, and general wellbeing in 1 cohort (maximal N = 46,508). Meta-analysis of these results showed no significant association between NEO-FFI personality polygenic scores and the wellbeing measures. IRT extraversion and neuroticism polygenic scores were used to predict life satisfaction and positive affect in almost 37,000 individuals from UK Biobank. Significant positive associations (effect sizes <0.05%) were observed between the extraversion polygenic score and wellbeing measures, and a negative association was observed between the polygenic neuroticism score and life satisfaction. Furthermore, using GWA data, genetic correlations of -0.49 and -0.55 were estimated between neuroticism with life satisfaction and positive affect, respectively. The moderate genetic correlation between neuroticism and wellbeing is in line with twin research showing that genetic influences on wellbeing are also shared with other independent personality domains.

Etched slices of the cuticle of the Silurian trilobite Homalonotus rhinotropis Angelin, 1854, from two localities in Skåne, southern Sweden, have been examined with the scanning electron microscope. The two major subdivisions of the cuticle are a “prismatic” (originally laminated) outer layer, about 20-30 μm thick, and a principal layer, 200-300 μm thick, which may be foliated or roughly laminated. The original finely-laminated aspect of the outer layer may sometimes be seen as a continuous layer, but is more frequently detected as “shaped inclusions” set in a prismatic background. These “shaped inclusions” are considered to have been produced by accumulation of minerals around the apices of 3-6 μm perpendicular canals early in calcification and preferentially preserved because of subtle differences from the products of later stages of the process. It is possible that calcification started before ecdysis. The difficulties involved in ascertaining the original structure of the principal layer are outlined, and possible reasons for differences in its preservation from the outer layer are proposed.

We compare the preservation (taphonomic grade) and age of Chione (bivalve) and foraminifera from modern siliciclastic tidal flat sediments of Bahia la Choya, Sonora, Mexico (northern Gulf of California). Disarticulated shells of Chione collected from the sediment-water interface of Choya Bay exhibit a substantial range in taphonomic grade and age, several hundred years to ∼80–125 ka based on Accelerator Mass Spectrometer 14C dates and D-Alloisoleucine/L-Isoleucine values. There is not, however, a one-to-one correspondence between age and taphonomic alteration of Chione: old (or young) valves may be highly altered or they may be relatively pristine. In contrast to Chione, most foraminiferal tests at Choya Bay are quite pristine, which suggests a quite young age, but tests are surprisingly old (up to ∼2,000 calendar years based on Accelerator Mass Spectrometer 14C dates).

We suggest that following seasonal pulses in reproduction, some foraminiferal tests are rapidly incorporated into a subsurface shell layer by “Conveyor Belt” deposit feeders and preserved there, while the rest of the reproductive pulse rapidly dissolves. Ultimately, some of these buried tests, along with Chione, are transported back to the surface by biological activity and storms. The much greater range of taphonomic grades and ages among Chione shells suggests that they, unlike foraminifera, are sufficiently large and preservable (low surface/volume ratio and chemical reactivity) to undergo many cycles of degradation, burial, and exhumation before complete destruction. The age of foraminiferal tests indicates that time-averaging of microfossil assemblages at Choya Bay is much more insidious than would be expected considering the relatively pristine state of the tests alone.

Based on our studies, the lower limit of temporal resolution of shallow shelf microfossil assemblages appears to be ∼1000 years. We caution, however, that each depositional setting (taphofacies) should be evaluated on a case-by-case basis before gross generalizations are made. Indeed, the discrepancy between age and taphonomic grade of fossil assemblages at Choya Bay suggests that neither hardpart size or taphonomic grade are infallible indicators of test preservability or likely temporal resolution of the host assemblage, and that the dynamics of hardpart input and loss must also be evaluated.

We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first- and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI.

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.

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.