A period of calm in Scottish seas: a comprehensive study of ΔR values for the northern British Isles coast and the consequent implications for archaeology and oceanography

The Marine Radiocarbon Reservoir Effect (MRE) is a 14C age offset between contemporaneous marine- and terrestrially-derived carbon. In Northern Hemisphere surface waters it is of the order of 400 years but temporal and spatial deviations, known as ΔR, occur. This study provides a comprehensive dataset of 21 ΔR and MRE values for the east coast of Scotland and 21 recalculated values for the west coast of Scotland and Ireland, for the period c. 3500 BC to 1450 AD. They are presented as mean, site-specific ΔR and MRE values, together with their associated uncertainties, calculated as standard errors for predicted values. The ΔR values range from -320 ± 35 to +150 ± 28 14C years and show no spatial or temporal trends. The MRE values range from 59 ± 40 to 531 ± 26, show an almost identical distribution pattern to the ΔR values and again show no spatial or temporal trends. Results show that ΔR values calculated for a single site using statistically indistinguishable groups of terrestrial and marine radiocarbon age measurements can produce variability of up to 225 14C years. ΔR is an important factor in the accurate calibration of samples containing marine-derived carbon for archaeological interpretation but is often also used as an indicator of changes in 14C specific activity of the oceans, and therefore a proxy for changes in ocean circulation and/or climate. Using the methods outlined in this paper, it is apparent that ΔR values for the northern part of the British Isles have been relatively stable, within our ability to quantify non-random variation in the data. The fact that significant climatic shifts have been recorded during this time, yet these are not visible in the ΔR data, presents a cautionary tale regarding the use of ΔR to infer large-scale oceanographic or climatic changes. Upon the exclusion of 5 outliers from the 42 values, the remaining ΔR values are statistically indistinguishable from one another and range from -142 ± 61 to +40 ± 47 14C years. 34 of these values are from Scottish archaeological sites and can be combined to produce a mean value for Scotland of -47 ± 52 14C years for the period 3500 BC to 1450 AD, to be used only in the absence of site- and period-specific data

Is the cultural transmission of irrelevant tool actions in adult humans (homo sapiens) best explained as the result of an evolved conformist bias?

BACKGROUND: Recent studies of social learning have revealed that adult humans are "over-imitators" who frequently reproduce a model's causally irrelevant tool actions to the detriment of task efficiency. At present our knowledge of adult over-imitation is limited to the fact that adults do over-imitate, we know very little about the causes of this behavior. The current study aimed to provide novel insights into adult over-imitation by extending a paradigm recently used with human children to explore social aspects of over-imitation. In the child study observers saw two models demonstrate a tool-use task using the same inefficient approach, or two models demonstrate different approaches to the task (one inefficient and one efficient). The manipulation of social influence came in the testing phase where the observer completed the task in the presence of either an inefficient model or an efficient model. METHODOLOGY/PRINCIPAL FINDINGS: We adapted the paradigm used in the child study to provide the first systematic exploration of factors which may lead to adult over-imitation including: 1) the presence of the model(s) during testing, 2) the presence of a competing efficient task demonstration, 3) the presence of a majority displaying the inefficient approach, and 4) the 'removal' of the experimental context during task completion. We show that the adult participants only over-imitated in conditions where the inefficient strategy was the majority approach witnessed. This tendency towards over-imitation was almost entirely eliminated when the participants interacted with the task when they believed the experiment to be complete. CONCLUSIONS: Our results suggest that adult over-imitation is best explained as a result of an evolved 'conformist bias' argued to be crucial to the transmission of human cultural behavior and one which may be unique in the animal kingdom

Population genetics of the farmland sawfly Dolerus aeneus (Hymenoptera, Symphyta)

Over the last 50 years populations of certain farmland birds have undergone severe declines over the same timescale that agriculture has intensified. The larvae of grassland sawflies (Hymenoptera, Symphyta) are a key component of the fledgling diet and it is thought that agri-intensification has reduced the numbers of these insects to such an extent that the populations of bird species dependent on them are limited. Sawfly populations may be more than usually susceptible to disturbance because firstly, their adult stages are poor dispersers and secondly, some species possess Complementary Sex Determination (CSD), a mechanism which can produce sterile males under inbreeding conditions. This study has produced a sawfly transcriptomic library through the use of 454 pyrosequencing, the first genetic resource for any farmland sawfly. From this library, a set of 13 polymorphic microsatellite markers were isolated for use in the common farmland sawfly Dolerus aeneus. Using these markers, three Scottish populations of D. aeneus, a species common to all six UK sites sampled in this study, exhibited similar levels of genetic diversity and low levels of genetic differentiation. However, evidence of inbreeding was detected in each of the three populations. In addition, potential diploid males were detected in D. aeneus using microsatellite markers, a primary indication that CSD may be operating in this species. The population genetic analysis in the current study suggests that fragmentation of suitable sawfly habitat as a result of agricultural intensification has not yet acted to isolate D. aeneus populations, although some genetic effects (inbreeding and low diversity compared with non-threatened hymenopterans) are apparent. In addition, diploid males have been detected which may have compromised fertility. This study will be of interest to research groups working on the genetics of the Hymenoptera and on the conservation and management of sawflies and the bird species dependent on them.EThOS - Electronic Theses Online ServiceGame and Wildlife Conservation TrustBiotechnology and Biological Sciences Research CouncilGBUnited Kingdo

Sex allocation theory reveals a hidden cost of neonicotinoid exposure in a parasitoid wasp

P.R.W. was funded by the University of Stirling, C.V.B. and S.M.G. were funded by Nuffield Research Placements and N.C., J.G. and D.M.S. were funded by NERC (NE/J024481/1).Sex allocation theory has proved to be one the most successful theories in evolutionary ecology. However, its role in more applied aspects of ecology has been limited. Here we show how sex allocation theory helps uncover an otherwise hidden cost of neonicotinoid exposure in the parasitoid wasp Nasonia vitripennis. Female N. vitripennis allocate the sex of their offspring in line with Local Mate Competition (LMC) theory. Neonicotinoids are an economically important class of insecticides, but their deployment remains controversial, with evidence linking them to the decline of beneficial species. We demonstrate for the first time to our knowledge, that neonicotinoids disrupt the crucial reproductive behaviour of facultative sex allocation at sub-lethal, field-relevant doses in N. vitripennis. The quantitative predictions we can make from LMC theory show that females exposed to neonicotinoids are less able to allocate sex optimally and that this failure imposes a significant fitness cost. Our work highlights that understanding the ecological consequences of neonicotinoid deployment requires not just measures of mortality or even fecundity reduction among non-target species, but also measures that capture broader fitness costs, in this case offspring sex allocation. Our work also highlights new avenues for exploring how females obtain information when allocating sex under LMC.Publisher PDFPeer reviewe

Pathology of chronic achilles-tendon injuries in athletes

Overuse tendon conditions have traditionally been considered to result from an inflammatory process and were treated as such. Microscopic examination of abnormal Achilles-tendon tissues, however, reveals a non-inflammatory degenerative process. The histopathology found in surgical specimens in patients with chronic overuse Achilles tendinopathy and those with Achilles-tendon rupture are reviewed. Seminal studies suggest that so-called tendinitis is a rare condition that might occur occasionally in the Achilles tendon in association with a primary tendinosis. These data have clinical implications and require a review of the traditional classification of pathologies seen in tendon conditions, The authors recommend that nomenclature be based on histopathological findings rather than traditional hypothesis. <br /

Validating the demethylating effects of 5-aza-2'-deoxycytidine in insects requires a whole-genome approach (A reply to Ellers et al.)

This work was initiated as part of Natural Environment Research Council grant NE/J024481/1.We previously demonstrated that treatment with the demethylating agent 5-aza-2′-deoxycytidine (5-azadC) alters the offspring sex ratios produced by females of the parasitoid wasp Nasonia vitripennis (Cook et al. 2015). Females allocate offspring sex ratio in line with Local Mate Competition theory, producing more or less female-biased sex ratios as the number of other females laying eggs on a patch varies, thereby reducing competition amongst their sons for mates. Interestingly, treatment with 5-aza-dC did not ablate the facultative sex allocation response. Instead, sex ratios became less female-biased, a shift in the direction of the optimum sex ratio for paternally-inherited alleles according to genomic conflict theory. This was the first (albeit indirect) experimental evidence for genomic conflict over sex allocation. Ellers et al. (2019) have since assayed the effects of 5-aza-dC on DNA methylation in ten Nasonia genes, finding no evidence of demethylation in these 10 genes, from which they conclude that 5-aza-dC has no demethylating capability in Nasonia vitripennis. Quantifying the efficacy of 5-aza-dC in terms of demethylation is indeed crucial to in-depth interpretation of studies using 5-aza-dC to link phenotypes to epigenetic regulation. Here, we outline the mode of action of 5-aza-dC and demonstrate that determining the efficacy of 5-aza-dC in insect systems requires a whole-genome approach.PostprintPeer reviewe

International Olympic Committee Consensus Statement: Molecular Basis of Connective Tissue and Muscle Injuries in Sport

Tendon and ligament injures cause significant loss of performance in sport and decreased functional capacity in the workplace. Many of these injures remain difficult to treat, and many individuals have long-term pain and discomfort. Animal studies of growth factor and cell-based therapies have shown promising results, but these treatments also can be misused to enhance athletic performance. The International Olympic Committee (IOC) now has high-level scientific advisors who can advise the IOC as to the use and abuse of these technologies

Inducing cold-sensitivity in the frigophilic fly Drosophila montana by RNAi

The work was supported by CNPq (Fellowship to FMV) and a NERC Studentship to DJP.Cold acclimation is a critical physiological adaptation for coping with seasonal cold. By increasing their cold tolerance individuals can remain active for longer at the onset of winter and can recover more quickly from a cold shock. In insects, despite many physiological studies, little is known about the genetic basis of cold acclimation. Recently, transcriptomic analyses in Drosophila virilis and D.montana revealed candidate genes for cold acclimation by identifying genes upregulated during exposure to cold. Here, we test the role of myo-inositol-1-phosphate synthase (Inos), in cold tolerance in D. montana using an RNAi approach. D. montana has a circumpolar distribution and overwinters as an adult in northern latitudes with extreme cold. We assessed cold tolerance of dsRNA knock-down flies using two metrics: chill-coma recovery time (CCRT) and mortality rate after cold acclimation. Injection of dsRNAInos did not alter CCRT,either overall or in interaction with the cold treatment, however it did induced cold specific mortality, with high levels of mortality observed in injected flies acclimated at 5°C but not at 19°C. Overall, injection with dsRNAInos induced a temperature sensitive mortality rate of over 60% in this normally cold-tolerant species. qPCRanalysis confirmed that dsRNA injection successfully reduced gene expression of Inos. Thus, our results demonstrate the involvement of Inos in increasing cold tolerance in D. montana. The potential mechanisms involved by which Inos increases cold tolerance are also discussed.Publisher PDFPeer reviewe