The vegetalizing factor A member of the evolutionarily highly conserved activin family

AbstractThe mesoderm and endoderm inducing vegetalizing factor was partially sequenced after BrCN cleavage. A sequence which is highly conserved in activin A near the C-terminal end was identified. This shows that the factor belongs to the activin family. The activins are not confined to embryos and gonads, but widely distributed in other tissues like calf kidney and calf liver. Functional aspects are discussed

The clockfront and wavefront model revisited

The currently accepted interpretation of the clock and wavefront model of somitogenesis is that a posteriorly moving molecular gradient sequentially slows the rate of clock oscillations, resulting in a spatial readout of temporal oscillations. However, while molecular components of the clocks and wavefronts have now been identified in the pre-somitic mesoderm (PSM), there is not yet conclusive evidence demonstrating that the observed molecular wavefronts act to slow clock oscillations. Here we present an alternative formulation of the clock and wavefront model in which oscillator coupling, already known to play a key role in oscillator synchronisation, plays a fundamentally important role in the slowing of oscillations along the anterior–posterior (AP) axis. Our model has three parameters which can be determined, in any given species, by the measurement of three quantities: the clock period in the posterior PSM, somite length and the length of the PSM. A travelling wavefront, which slows oscillations along the AP axis, is an emergent feature of the model. Using the model we predict: (a) the distance between moving stripes of gene expression; (b) the number of moving stripes of gene expression and (c) the oscillator period profile along the AP axis. Predictions regarding the stripe data are verified using existing zebrafish data. We simulate a range of experimental perturbations and demonstrate how the model can be used to unambiguously define a reference frame along the AP axis. Comparing data from zebrafish, chick, mouse and snake, we demonstrate that: (a) variation in patterning profiles is accounted for by a single nondimensional parameter; the ratio of coupling strengths; and (b) the period profile along the AP axis is conserved across species. Thus the model is consistent with the idea that, although the genes involved in pattern propagation in the PSM vary, there is a conserved patterning mechanism across species

A mental health-informed, online health promotion programme targeting physical activity and healthy eating for adults aged 60+ years: study protocol for the MovingTogether randomised controlled trial

Background: The COVID-19 pandemic and associated social distancing regulations have led to an increased risk of social isolation and physical inactivity, particularly among older adults. The benefits of physical activity for reducing fall risk and improving mood and mental functioning have been well documented. The aim of this trial is to investigate the effect of the MovingTogether programme on psychological distress (primary outcome) and physical activity, social capital, cognition, concern about falling, loneliness, physical functioning, quality of life and physical activity enjoyment (secondary outcomes). Methods: A randomised controlled trial with a waitlist control will be conducted, recruiting 80 adults aged 60+ years with access to Facebook and a computer or tablet and not currently meeting the aerobic physical activity guidelines. Randomisation will be completed using REDCap. The intervention group (n = 40) will join a private Facebook group where allied health facilitators will provide targeted healthy lifestyle education throughout the 10-week programme with weekly telehealth group calls. Intervention participants will also be provided access to tailored strength and aerobic exercise guidance and an evidence-based eHealth balance exercise programme. Psychological distress and secondary outcomes will be assessed at baseline, 11 weeks (post-intervention) and 16 weeks (1-month follow-up). Linear mixed models will be applied for each outcome measure as per an intention-to-treat approach to determine the between-group differences. Secondary analyses are planned in people with greater adherence and those with higher psychological distress. Discussion: COVID-19 has highlighted the need for scalable, effective and novel methods to improve and protect the health of older adults. The integration of an evidence-based fall prevention programme with a mental health-informed online health promotion programme may help to improve mental and physical health outcomes among older adults. Trial registration: Australian New Zealand Clinical Trials Registry (ANZCTR) ACTRN12621001322820p. Registered on 29 September 2021

Tectonic motion site survey of the National Radio Astronomy Observatory, Green Bank, West Virginia

A geological and geophysical site survey was made of the area around the National Radio Astronomy Observatory (NRAO) to determine whether there are at present local tectonic movements that could introduce significant errors to Very Long Baseline Interferometry (VLBI) geodetic measurements. The site survey consisted of a literature search, photogeologic mapping with Landsat and Skylab photographs, a field reconnaissance, and installation of a seismometer at the NRAO. It is concluded that local tectonic movement will not contribute significantly to VLBI errors. It is recommended that similar site surveys be made of all locations used for VLBI or laser ranging

No evidence for a role of MHC class II genotype in the chemical encoding of heterozygosity and relatedness in Antarctic fur seals

Despite decades of research, surprisingly little is known about the mechanism(s) by which an individual's genotype is encoded in odour. Many studies have focused on the role of the major histocompatibility complex (MHC) owing to its importance for survival and mate choice. However, the salience of MHC-mediated odours compared to chemicals influenced by the rest of the genome remains unclear, especially in wild populations where it is challenging to quantify and control for the effects of the genomic background. We addressed this issue in Antarctic fur seals by analysing skin swabs together with full-length MHC DQB II exon 2 sequences and data from 41 genome-wide distributed microsatellites. We did not find any effects of MHC relatedness on chemical similarity and there was also no relationship between MHC heterozygosity and chemical diversity. However, multilocus heterozygosity showed a significant positive association with chemical diversity, even after controlling for MHC heterozygosity. Our results appear to rule out a dominant role of the MHC in the chemical encoding of genetic information in a wild vertebrate population and highlight the need for genome-wide approaches to elucidate the mechanism(s) and specific genes underlying genotype-odour associations

Investigating harbor porpoise (Phocoena phocoena) population differentiation using RAD-tag genotyping by sequencing

The population status of the harbor porpoise ( Phocoena phocoena ) in the Baltic Sea and adjacent regions is still not fully resolved. Here, we present a pilot study using the double digest restriction-site associated DNA sequencing (ddRAD-seq) genotyping- by -sequencing method on specimens from the Baltic Sea, eastern North Sea, Spain and the Black Sea. From a single Illumina lane and a set of 49 individuals, w e obtained around 6000 SNPs. We used these markers to estimate population structure and differentiation, and identified splits between porpoises from the North Sea and the Baltic, and within regions in the Baltic Sea (between the Belt Sea and the Inner Baltic Sea). The SNP analysis confirms population structure elucidated by previous mtDNA/microsatellite studies. We demonstrate the feasibility of SNP analysis on opportunistically sampled cetacean samples, with varying DNA quality, for population diversity and divergence analysis

Nuclear Charge Radii of Be-7,9,10 and the one-neutron halo nucleus Be-11

Nuclear charge radii of $^{7,9,10,11}$Be have been determined by high-precision laser spectroscopy. On-line measurements were performed with collinear laser spectroscopy in the $2s_{1/2} \to 2p_{1/2}$ transition on a beam of Be$^{+}$ ions. Collinear and anticollinear laser beams were used simultaneously and the absolute frequency determination using a frequency comb yielded an accuracy in the isotope-shift measurements of about 1 MHz. Combination with accurate calculations of the mass-dependent isotope shifts yield nuclear charge radii. The charge radius decreases from $^7$Be to $^{10}$Be and then increases for the halo nucleus $^{11}$Be. When comparing our results with predictions of {\it ab initio} nuclear structure calculations we find good agreement. Additionally, the nuclear magnetic moment of $^7$Be was determined to be $-1.3995(5)\mu_{\rm N}$ and that of $^{11}$Be from a previous $\beta$-NMR measurement was confirmed.Comment: 4 pages, 2 figures calculated mass shift values have been re-evaluated with the latest mass values for the beryllium isotopes and the nuclear polarization contribution for Be-11, published by K. Pachucki et al. ater submission of our manuscript, is also included no