Testing mechanisms of Bergmann’s rule: Phenotypic decline but no genetic change in body size in three posserine bird populations

Bergmann’s rule predicts a decrease in body size with increasing temperature and has much empirical support. Surprisingly, we know very little about whether “Bergmann size clines” are due to a genetic response or are a consequence of phenotypic plasticity. Here, we use data on body size (mass and tarsus length) from three long-term (1979–2008) study populations of great tits (Parus major) that experienced a temperature increase to examine mechanisms behind Bergmann’s rule. We show that adult body mass decreased over the study period in all populations and that tarsus length increased in one population. Both body mass and tarsus length were heritable and under weak positive directional selection, predicting an increase, rather than a decrease, in body mass. There was no support for microevolutionary change, and thus the observed declines in body mass were likely a result of phenotypic plasticity. Interestingly, this plasticity was not in direct response to temperature changes but seemed to be due to changes in prey dynamics. Our results caution against interpreting recent phenotypic body size declines as adaptive evolutionary responses to temperature changes and highlight the importance of considering alternative environmental factors when testing size clines.

Effect of nickel in solid solution on hydrogen transport kinetics in low alloy steels

The use of low alloy steels (LAS) in H2S-containing environments in the oil and gas industry is governed by the ISO standard 15156-2 (NACE MR0175-2). One requirement, which has been disputed over the years, is that the nickel (Ni) content shall not exceed 1 wt%. This work investigated the effect of Ni in solid solution on hydrogen diffusion, solubility, and trapping in ferritic/pearlitic research-grade LAS with nominal Ni contents from 0 to 3 wt%. Hydrogen permeability experiments were carried out in a Devanathan-Stachurski setup at 15, 45 and 70 °C. The effective diffusion coefficients, calculated by the tlag method, decreased with increasing Ni content. The sub-surface hydrogen concentration in lattice and trap sites increased with increasing Ni content. There was no difference between the first and subsequent hydrogen permeation transients, suggesting that Ni in solid solution forms reversible traps. The effect of Ni in refining the microstructure may be superimposed on the effect of Ni in solid solution, and should be investigated in future work

In Vitro Evaluation of Therapeutic Laser Treatment on Equine Tendon Fibroblasts

Previous investigations have failed to show benefits of low level laser therapy (LLLT) for tendon healing in horses, contrary to reports in other species. We hypothesized that delivery of LLLT at manufacturer-recommended energy fluence through equine cadaver skin to equine tendon-derived fibroblasts in vitro would increase cell proliferation, metabolic activity and migration. Fibroblasts from grossly normal front superficial digital flexor tendons of four horses euthanatized for reasons unrelated to the study were cultured in monolayer. Cells were treated through one of three equine cadaver skin samples (light, medium, or dark colored) at manufacturer-recommended energy fluence. Untreated cells served as controls. At 24 hours after treatment, cell proliferation was determined via manual cell counts and cellular metabolic rate was assessed via resazurin sodium salt reduction assay. Cell migration was determined by scratch assay and by transwell migration assay. Data was analyzed by repeated measures ANOVA with p<0.05 considered significant. There was no difference between groups in cell numbers (p=0.2497), cell viability (p=0.4326), in fraction of reduced resazurin salt (p=0.2613), in number of cells migrating along a chemotactical gradient (p=0.4914), or for scratch width (p=0.6685) and scratch scores (p=0.5129). No beneficial effects of LLLT were found for tendon healing in horses under the study conditions

Comparative support for the expensive tissue hypothesis: Big brains are correlated with smaller gut and greater parental investment in Lake Tanganyika cichlids

This is the final version of the article. Available from the publisher via the DOI in this record.The brain is one of the most energetically expensive organs in the vertebrate body. Consequently, the energetic requirements of encephalization are suggested to impose considerable constraints on brain size evolution. Three main hypotheses concerning how energetic constraints might affect brain evolution predict covariation between brain investment and (1) investment into other costly tissues, (2) overall metabolic rate, and (3) reproductive investment. To date, these hypotheses have mainly been tested in homeothermic animals and the existing data are inconclusive. However, there are good reasons to believe that energetic limitations might play a role in large-scale patterns of brain size evolution also in ectothermic vertebrates. Here, we test these hypotheses in a group of ectothermic vertebrates, the Lake Tanganyika cichlid fishes. After controlling for the effect of shared ancestry and confounding ecological variables, we find a negative association between brain size and gut size. Furthermore, we find that the evolution of a larger brain is accompanied by increased reproductive investment into egg size and parental care. Our results indicate that the energetic costs of encephalization may be an important general factor involved in the evolution of brain size also in ectothermic vertebrates.The authors thank the staff of the Department of Fisheries of the Ministry of Agriculture and Cooperatives at Mpulungu, Zambia, for their cooperation during fieldwork, especially for collecting fishes from the deeper levels. They also thank H. Tanaka for collecting fish samples for us. This study was funded through the student exchange support program (scholarship for long-term study abroad) from the Japanese Student Services Organization (JASSO) to MT, the Zoologiska foundation to MT and AK, a Davis Expedition Fund grant, Helge Axelsson Johnson grant, and a Stiftelsen Hierta-Retzius stipendiefond grant to AH, the Austrian Science Fund (J 3304-B24) to AK, and a Swedish Research Council grant to NK. The authors have no conflict of interest to declare

Population trends of waders on their boreal and arctic breeding grounds in northern Europe

Waders form a conspicuous part of the bird fauna in boreal and arctic areas, where they inhabit forests, wetlands, mires and tundra. These are important breeding areas for a large set of wader species, and may be particularly vulnerable to climate change. However, large-scale and systematic monitoring data from the breeding grounds of boreal and arctic waders are largely lacking. We present population trends for 22 wader species breeding in the boreal and arctic parts of Fennoscandia (Norway, Sweden and Finland) between 2006 and 2018. The trends are based on 9,713 surveys of 1,505 unique routes (6–8 km), each surveyed in at least two years, evenly distributed over an area of ~1 million km2. The trends were significantly negative for three species: Red-necked Phalarope Phalaropus lobatus (–7.9% year-1), Broad-billed Sandpiper Calidris falcinellus (–5.4% year-1), and Whimbrel Numenius phaeopus (–1.3% year-1). The trends were significantly positive for three species: Oystercatcher Haematopus ostralegus (+4.9% year-1), Dunlin Calidris a. alpina (+4.2% year-1) and Wood Sandpiper Tringa glareola (+0.8% year-1). For the remaining species, we found no statistically significant trends. On average, as shown by a multi-species indicator, there was no general change in numbers over time. On 1,539 routes with at least one survey, wader species richness as well as total number of wader pairs increased significantly with increasing latitude. Species population trend was not correlated with breeding latitude, but population trends of long-distance migrants tended to be more negative than those of medium-distance migrants. The recent fortunes of waders breeding in northern Fennoscandia have been more buoyant than those in other parts of Europe, but the trends for some species are worrying. © 2019, International Wader Study Group. All rights reserved.Peer reviewe

A Nordic survey of CT doses in hybrid PET/CT and SPECT/CT examinations

Background Computed tomography (CT) scans are routinely performed in positron emission tomography (PET) and single photon emission computed tomography (SPECT) examinations globally, yet few surveys have been conducted to gather national diagnostic reference level (NDRL) data for CT radiation doses in positron emission tomography/computed tomography (PET/CT) and single photon emission computed tomography/computed tomography (SPECT/CT). In this first Nordic-wide study of CT doses in hybrid imaging, Nordic NDRL CT doses are suggested for PET/CT and SPECT/CT examinations specific to the clinical purpose of CT, and the scope for optimisation is evaluated. Data on hybrid imaging CT exposures and clinical purpose of CT were gathered for 5 PET/CT and 8 SPECT/CT examinations via designed booklet. For each included dataset for a given facility and scanner type, the computed tomography dose index by volume (CTDIvol) and dose length product (DLP) was interpolated for a 75-kg person (referred to as CTDIvol,75kg and DLP75kg). Suggested NDRL (75th percentile) and achievable doses (50th percentile) were determined for CTDIvol,75kg and DLP75kg according to clinical purpose of CT. Differences in maximum and minimum doses (derived for a 75-kg patient) between facilities were also calculated for each examination and clinical purpose. Results Data were processed from 83 scanners from 43 facilities. Data were sufficient to suggest Nordic NDRL CT doses for the following: PET/CT oncology (localisation/characterisation, 15 systems); infection/inflammation (localisation/characterisation, 13 systems); brain (attenuation correction (AC) only, 11 systems); cardiac PET/CT and SPECT/CT (AC only, 30 systems); SPECT/CT lung (localisation/characterisation, 12 systems); bone (localisation/characterisation, 30 systems); and parathyroid (localisation/characterisation, 13 systems). Great variations in dose were seen for all aforementioned examinations. Greatest differences in DLP75kg for each examination, specific to clinical purpose, were as follows: SPECT/CT lung AC only (27.4); PET/CT and SPECT/CT cardiac AC only (19.6); infection/inflammation AC only (18.1); PET/CT brain localisation/characterisation (16.8); SPECT/CT bone localisation/characterisation (10.0); PET/CT oncology AC only (9.0); and SPECT/CT parathyroid localisation/characterisation (7.8). Conclusions Suggested Nordic NDRL CT doses are presented according to clinical purpose of CT for PET/CT oncology, infection/inflammation, brain, PET/CT and SPECT/CT cardiac, and SPECT/CT lung, bone, and parathyroid. The large variation in doses suggests great scope for optimisation in all 8 examinations.Peer reviewe

Social networks strongly predict the gut microbiota of wild mice

The mammalian gut teems with microbes, yet how hosts acquire these symbionts remains poorly understood. Research in primates suggests that microbes can be picked up via social contact, but the role of social interactions in non-group-living species remains underexplored. Here, we use a passive tracking system to collect high resolution spatiotemporal activity data from wild mice (Apodemus sylvaticus). Social network analysis revealed social association strength to be the strongest predictor of microbiota similarity among individuals, controlling for factors including spatial proximity and kinship, which had far smaller or nonsignificant effects. This social effect was limited to interactions involving males (male-male and male-female), implicating sex-dependent behaviours as driving processes. Social network position also predicted microbiota richness, with well-connected individuals having the most diverse microbiotas. Overall, these findings suggest social contact provides a key transmission pathway for gut symbionts even in relatively asocial mammals, that strongly shapes the adult gut microbiota. This work underlines the potential for individuals to pick up beneficial symbionts as well as pathogens from social interactions.Peer reviewe

Therapeutic affordances of online support group use in women with endometriosis

Background: The Internet has provided women living with endometriosis new opportunities to seek support online. Online support groups may provide a range of therapeutic affordances which may benefit these women. Objective: To examine the presence of therapeutic affordances as perceived by women who use endometriosis online support groups. Methods: Sixty-nine women (aged 19 to 50 years; Mean = 34.2; 65.2% UK; 21.7% USA) participated in an online interview exploring online support group use. Participants had been using online support groups on average 2 years and 4 months (Range = 1 month to 14 years, 9 months). Responses were analysed using inductive thematic analysis. Results: The analysis revealed 4 therapeutic affordances related to online support group use; i) “connection” i.e. the ability to connect in order to support each other, exchange advice, and to try to overcome feelings of loneliness; ii) “exploration” i.e. the ability to look for information, learn and bolster their knowledge; iii) “narration” i.e. the ability to share their experiences, as well as read about the experiences of others; and iv) “self-presentation” i.e. the ability to manage how they present themselves online. The associated outcomes of use were predominantly positive, such as reassurance and improved coping. However, a number of negative aspects were revealed including: concerns about the accuracy of information, arguments between members, over-reliance on the group, becoming upset by negative experiences or good news items and confidentiality of personal information. Conclusions: Our findings support the SCENA model (Self-presentation, Connection, Exploration, Narration and Adaptation) proposed by Merolli et al., (2014) and reveal a range of positive aspects that may benefit members, particularly in relation to reassurance and coping. However, negative aspects need to be addressed in order to maximise the potential benefit of support groups. Some of these can be addressed relatively easily through making privacy policies clearer, including health professionals to moderate content and structuring forums to encourage the sharing of positive stories