Predation by the sea urchin Strongylocentrotus droebachiensis on capsular egg masses of the whelk Buccinum undatum

We evaluated sea urchin Strongylocentrotus droebachiensis predation on egg masses of the whelk Buccinum undatum. The urchin actively grazes on the egg masses, even as they are being deposited on the bottom. Whelks preferentially lay their egg masses on vertical areas where urchin densities are 4-fold less than on flat areas. This strategy is advantageous, as experimental trials showed that the loss in the mass of capsules was 4 fewer on walls than on flat areas. Nevertheless, a high proportion of egg masses on walls show damage from predation. Urchins provided with egg masses in the laboratory, ingested the capsules at a steady rate over a 9-d period (5 urchins ingested 2.8 g.d-1). Urchins provided agar discs that included a preferred alga and whelk capsule walls ingested the discs at a rate that was half that observed for discs that only included the alga. Discs that included the preferred alga and capsule contents were eaten at the same rate as discs that only included the alga. Thus, capsule walls, but not the capsule contents, provide a defence against urchin predation. Laying aggregate egg masses likely provides only a limited advantage, as the attachment surface does not increase with the number of egg masses deposited together, so the risk of detachment increases. Consideration of the interactions between urchins and whelks is important in managing the fisheries of the two species. Copyright © Marine Biological Association of the United Kingdom 2008.published_or_final_versio

Effect of vitamin K2 on postural sway in older people who fall:a randomized controlled trial

OBJECTIVES: Vitamin K is thought to be involved in both bone health and maintenance of neuromuscular function. We tested the effect of vitamin K2 supplementation on postural sway, falls, healthcare costs, and indices of physical function in older people at risk of falls.DESIGN: Parallel-group double-blind randomized placebo-controlled trial.SETTING: Fourteen primary care practices in Scotland, UK.PARTICIPANTS: A total of 95 community-dwelling participants aged 65 and older with at least two falls, or one injurious fall, in the previous year.INTERVENTION: Once/day placebo, 200 μg or 400 μg of oral vitamin K2 for 1 year.MEASUREMENTS: The primary outcome was anteroposterior sway measured using sway plates at 12 months, adjusted for baseline. Secondary outcomes included the Short Physical Performance Battery, Berg Balance Scale, Timed Up &amp; Go Test, quality of life, health and social care costs, falls, and adverse events.RESULTS: Mean participant age was 75 (standard deviation [SD] = 7) years. Overall, 58 of 95 (61%) were female; 77 of 95 (81%) attended the 12-month visit. No significant effect of either vitamin K2 dose was seen on the primary outcome of anteroposterior sway (200 μg vs placebo: -.19 cm [95% confidence interval [CI] -.68 to .30; P = .44]; 400 μg vs placebo: .17 cm [95% CI -.33 to .66; P = .50]; or 400 μg vs 200 μg: .36 cm [95% CI -.11 to .83; P = .14]). Adjusted falls rates were similar in each group. No significant treatment effects were seen for other measures of sway or secondary outcomes. Costs were higher in both vitamin K2 arms than in the placebo arm.CONCLUSION: Oral vitamin K2 supplementation did not improve postural sway or physical function in older people at risk of falls.</p

Multifactorial Aspects of Adiponectin in Non- Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) is a significant worldwide health issue strongly associated with obesity and metabolic syndrome. It underscores the critical role of adiponectin, a significant adipokine, in the disease's intricate progression. NAFLD's complexity stems from its interplay with factors like obesity, diabetes, and metabolic syndrome, with reduced adiponectin levels commonly observed in NAFLD patients, influenced by age, gender, lipid profiles, and insulin resistance. Adiponectin's versatility in mitigating insulin resistance, inflammation, and liver fibrosis makes it a focal point in NAFLD research, while recent studies introduce spexin, a neuropeptide, as a potential correlate, adding to the understanding of metabolic disorders. To tailor treatment approaches, recognizing the factors affecting adiponectin levels, such as genetics, lifestyle, and comorbidities, is crucial. Lifestyle changes and specific medications offer promise in improving NAFLD outcomes by modulating adiponectin. The article underscores adiponectin's central role in the complex NAFLD landscape and the need for further research to fully grasp its mechanisms and therapeutic potential in managing this prevalent liver disease, emphasizing the importance of rebalancing adipokines and enhancing metabolic health

Study of alkaline hydrothermal activation of belite cements by thermal analysis

The effect of alkaline hydrothermal activation of class-C fly ash belite cement was studied using thermal analysis (TG/DTG) by determining the increase in the combined water during a period of hydration of 180 days. The results were compared with those obtained for a belite cement hydrothermally activated in water. The two belite cements were fabricated via the hydrothermal-calcination route of class-C fly ash in 1 M NaOH solution (FABC-2-N) or demineralised water (FABC-2-W). From the results, the effect of the alkaline hydrothermal activation of belite cement (FABC-2-N) was clearly differentiated, mainly at early ages of hydration, for which the increase in the combined water was markedly higher than that of the belite cement that was hydrothermally activated in water. Important direct quantitative correlations were obtained among physicochemical parameters, such as the combined water, the BET surface area, the volume of nano-pores, and macro structural engineering properties such as the compressive mechanical strength

Out of Amazonia: Late Holocene Climate Change and the Tupi-Guarani Trans-Continental Expansion

This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this recordThe late Holocene expansion of the Tupi-Guarani languages from southern Amazonia to SE South America constitutes one of the largest expansions of any linguistic family in the world, spanning ~ 4000 km between latitudes 0°S and 35°S at about 2500 yr B.P. However, the underlying reasons for this expansion are a matter of debate. Here, we compare continental-scale paleoecological, paleoclimate, and archaeological datasets, to examine the role of climate change in facilitating the expansion of this forest-farming culture. Because this expansion lies within the path of the South American Low-Level Jet, the key mechanism for moisture transport across lowland South America, we were able to explore the relationship between climate change, forest expansion, and the Tupi-Guarani. Our data synthesis shows broad synchrony between late Holocene increasing precipitation and southerly expansion of both tropical forest and Guarani archaeological sites – the southernmost branch of the Tupi-Guarani. We conclude that climate change likely facilitated expansion of the Guarani forest-farming culture by increasing the area of forested landscape that they could exploit, showing a prime example of ecological opportunism.The ideas and themes developed in this paper stem from a European Research Council project ‘Pre-Columbian Amazon-Scale Transformations’ (ERC-CoG 616179) to JI. The University of Reading’s ‘Centre for Past Climate Change’ funded a writing workshop for this paper. RS was funded by an NERC ‘Scenario’ DTP PhD award. JGS was funded by a CAPES PhD scholarship (Ministry of Education, Brazil). JFC and MLC received postdoctoral funding from the University of Reading and the Arts and Humanities Research Council, respectively

Targeting of MuLV Gag to the plasma membrane is mediated by PI(4,5)P2 and PhosphatidylSerine

Oral presentationInternational audienceMembrane targeting by the modern human immunodeficiency viruses is dependent on the plasma membrane-located phospholipid PI(4,5)P2. In order to determine if evolutionarily distant retroviruses are targeted by a similar mechanism, we generated mutant Gag constructs in the matrix (MA) domain of the Murine Leukemia Virus (MuLV) and examined their binding to membrane models and phenotypes in cell culture. Mutations in the MA polybasic region altered Gag localization, membrane binding and virion production. In addition, we show that MA binds with good affinity to all the phosphatidylinositol phosphates but displays a strong specificity for PI(4,5)P2 only if enhanced by phophatidylserine. Virus production was strongly impaired by PI(4,5)P2 depletion under 5ptaseIV overexpression. Our results suggest that the N-terminal polybasic region of MA is essential for Gag targeting to the plasma membrane and Gag cellular trafficking. The binding of the MA domain to PI(4,5)P2 appears to be a conserved feature among retroviruses, despite the fact that the MuLV-MA domain is structurally different from that of HIV-1 and -2 and lacks a readily identifiable PI(4,5)P2 binding cleft

Kank Is an EB1 Interacting Protein that Localises to Muscle-Tendon Attachment Sites in Drosophila

Little is known about how microtubules are regulated in different cell types during development. EB1 plays a central role in the regulation of microtubule plus ends. It directly binds to microtubule plus ends and recruits proteins which regulate microtubule dynamics and behaviour. We report the identification of Kank, the sole Drosophila orthologue of human Kank proteins, as an EB1 interactor that predominantly localises to embryonic attachment sites between muscle and tendon cells. Human Kank1 was identified as a tumour suppressor and has documented roles in actin regulation and cell polarity in cultured mammalian cells. We found that Drosophila Kank binds EB1 directly and this interaction is essential for Kank localisation to microtubule plus ends in cultured cells. Kank protein is expressed throughout fly development and increases during embryogenesis. In late embryos, it accumulates to sites of attachment between muscle and epidermal cells. A kank deletion mutant was generated. We found that the mutant is viable and fertile without noticeable defects. Further analysis showed that Kank is dispensable for muscle function in larvae. This is in sharp contrast to C. elegans in which the Kank orthologue VAB-19 is required for development by stabilising attachment structures between muscle and epidermal cells