A study of the inter-bouton exchange of synaptic vesicles at central synapses.

Neurotransmitter release at central synapses is sustained by the synaptic vesicle cycle. It has been assumed that vesicle replenishment operates autonomously at individual presynaptic terminals. In this study the classical model of a compartmentalized synaptic vesicle cycle was tested by using a novel combination of FRAP (fluorescence recovery after photobleaching) and CLEM (correlative light and electron microscopy) in cultured hippocampal neurons. The stability of vesicle clusters labelled with fluorescent styryl dye at individual synapses were assessed by photobleaching using a confocal laser microscope and monitoring fluorescence recovery over time. The observed fluorescence recovery which was abolished by inhibitors of vesicular transport, suggested that synaptic vesicles recycled at sites outside the bleach region were transported along axons into bleached synapses. These newly-imported vesicles could undergo exocytosis upon stimulation, demonstrating that they formed part of the functional recycling pool. The spatial organization of imported vesicles in presynaptic boutons was examined using CLEM and FM dye photoconversion techniques. Imported vesicles were distributed throughout the native vesicle cluster, indicating that they become morphologically integrated into the synapse. The ability of imported vesicles to mix well with native vesicles highlights the dynamic nature of vesicle clusters at resting synapses. The departure of fluorescent packets from boutons into axons was observed by time- lapse microscopy. Ultrastructural analysis confirmed the mature state of donor synapses and showed these mobile packets to be loose aggregates of synaptic vesicles. Mobile vesicle clusters were comprised of vesicles from both the recycling and resting pools of the synapse, thus demonstrating no preference for mobility of any one vesicle population

Adverse obstetric and perinatal outcomes following treatment of adolescent and young adult cancer: A population-based cohort study

Objective - To investigate obstetric and perinatal outcomes among female survivors of adolescent and young adult (AYA) cancers and their offspring. Methods - Using multivariate analysis of statewide linked data, outcomes of all first completed pregnancies (n = 1894) in female survivors of AYA cancer diagnosed in Western Australia during the period 1982–2007 were compared with those among females with no cancer history. Comparison pregnancies were matched by maternal age-group, parity and year of delivery. Results - Compared with the non-cancer group, female survivors of AYA cancer had an increased risk of threatened abortion (adjusted relative risk 2.09, 95% confidence interval 1.51–2.74), gestational diabetes (2.65, 2.08–3.57), pre-eclampsia (1.32, 1.04–1.87), post-partum hemorrhage (2.83, 1.92–4.67), cesarean delivery (2.62, 2.22–3.04), and maternal postpartum hospitalization>5 days (3.01, 1.72–5.58), but no excess risk of threatened preterm delivery, antepartum hemorrhage, premature rupture of membranes, failure of labor to progress or retained placenta. Their offspring had an increased risk of premature birth (<37 weeks: 1.68, 1.21–2.08), low birth weight (<2500 g: 1.51, 1.23–2.12), fetal growth restriction (3.27, 2.45–4.56), and neonatal distress indicated by low Apgar score (<7) at 1 minute (2.83, 2.28–3.56), need for resuscitation (1.66, 1.27–2.19) or special care nursery admission (1.44, 1.13–1.78). Congenital abnormalities and perinatal deaths (intrauterine or ≤7 days of birth) were not increased among offspring of survivors. Conclusion - Female survivors of AYA cancer have moderate excess risks of adverse obstetric and perinatal outcomes arising from subsequent pregnancies that may require additional surveillance or intervention

Learning and digital inclusion: the ELAMP project

The Electronic Learning and Mobility Project (ELAMP) was a nationally funded project by the Department for Children, Schools and Families, which ran from 2004 to 2010. The main aim of ELAMP was to improve the education of Traveller children, particularly highly mobile learners. ELAMP focussed upon the use of mobile technology and distance learning to support, enhance and extend young Travellers’ educational and vocational opportunities. This article will reflect upon the learning and technological experiences and opportunities that the ELAMP project provided for Traveller children, young people and their families. In doing so it will critically consider the value of information technology in working with Traveller communities and advancing their educational opportunities. Reviewing ELAMP work will also demonstrate how the use of mobile technology can improve educational outcomes and Traveller families’ digital inclusion. Now that the project has ended, this article will question why we are not using what we learnt from ELAMP to move forward

Spiral cracks in drying precipitates

We investigate the formation of spiral crack patterns during the desiccation of thin layers of precipitates in contact with a substrate. This symmetry-breaking fracturing mode is found to arise naturally not from torsion forces, but from a propagating stress front induced by the fold-up of the fragments. We model their formation mechanism using a coarse-grain model for fragmentation and successfully reproduce the spiral cracks. Fittings of experimental and simulation data show that the spirals are logarithmic, corresponding to constant deviation from a circular crack path. Theoretical aspects of the logarithmic spirals are discussed. In particular we show that this occurs generally when the crack speed is proportional to the propagating speed of stress front.Comment: 4 pages, 5 figures, RevTe

Of Time, Renewal, and Scholarship: Volume 11 (2021) Wrapped

This editorial discusses the articles published and the activities undertaken by The Comics Grid: Journal of Comics Scholarship during 2021, and calls for research system-wide cultural changes and wider contextual awareness in order to make scholarly communication fairer and up to the challenges of our time

National Survey of Sea Lice (Lepeophtheirus salmonis Krøyer and Caligus elongatus Nordmann) on Fish Farms in Ireland – 2019

Farmed stocks of Atlantic salmon in Ireland are inspected on 14 occasions throughout the year to monitor sea lice levels as part of a national programme. Sea lice are a naturally occurring parasite found on marine fish, including salmonids. They are small ecto-parasitic copepod crustaceans and there are approximately 559 species. The objectives of the National Sea Lice Monitoring Programme are: To provide an objective measurement of infestation levels on farms. To investigate the nature of infestations. To provide management information to drive the implementation of control and management strategies. To facilitate further development and refinement of this strategy. The sea lice control and management strategy has five principal components: Separation of generations. Annual fallowing of sites. Early harvest of two-sea-winter fish. Targeted treatment regimes, including synchronous treatments. Agreed husbandry practices

Pay progression in routinised service sector work: navigating the internal labour market in a fast food multinational company

The United Kingdom's widespread use of low‐skill, low‐paid employment has been well documented. It has been argued internal labour markets (ILMs) benefit such workers, affording them with opportunities for progression. Relatively little is known, however, about the impact of ILMs on entry level workers undertaking routinised service sector work. Drawing on qualitative data, this article explores the prospects on offer in a market leading, fast food multinational company. Potential enabling features include on‐the‐job training, a transparent and integrated pay structure and a professed culture of progression. Occupational movements to positions above the low‐pay threshold are, however, relatively rare. We conjecture this contradiction is the result of the business context in which the firm operates. The findings suggest that in sectors where price leadership strategies dominate, escape from low pay is likely to be exceptional, even within large organisations featuring some of the classic characteristics of ‘pure’ or strong ILMs

Can quantum fractal fluctuations be observed in an atom-optics kicked rotor experiment?

We investigate the parametric fluctuations in the quantum survival probability of an open version of the delta-kicked rotor model in the deep quantum regime. Spectral arguments [Guarneri I and Terraneo M 2001 Phys. Rev. E vol. 65 015203(R)] predict the existence of parametric fractal fluctuations owing to the strong dynamical localisation of the eigenstates of the kicked rotor. We discuss the possibility of observing such dynamically-induced fractality in the quantum survival probability as a function of the kicking period for the atom-optics realisation of the kicked rotor. The influence of the atoms' initial momentum distribution is studied as well as the dependence of the expected fractal dimension on finite-size effects of the experiment, such as finite detection windows and short measurement times. Our results show that clear signatures of fractality could be observed in experiments with cold atoms subjected to periodically flashed optical lattices, which offer an excellent control on interaction times and the initial atomic ensemble.Comment: 18 pp, 7 figs., 1 tabl

Paleo-denudation rates suggest variations in runoff drove aggradation during last glacial cycle, Crete, Greece

Fluvial aggradation and incision are often linked to Quaternary climate cycles, but it usually remains unclear whether variations in runoff or sediment supply or both drive channel response to climate variability. Here we quantify sediment supply with paleo-denudation rates and provide geochronological constraints on aggradation and incision from the Sfakia and Elafonisi alluvial-fan sequences in Crete, Greece. We report seven optically stimulated luminescence and ten radiocarbon ages, eight 10Be and eight 36Cl denudation rates from modern channel and terrace sediments. For five samples, 10Be and 36Cl were measured on the same sample by measuring 10Be on chert and 36Cl on calcite. Results indicate relatively steady denudation rates throughout the past 80 kyr, but the aggradation and incision history indicates a link with climate shifts. At the Elafonisi fan, we identify four periods of aggradation coinciding with Marine Isotope Stages (MIS) 2, 4, 5a/b, and likely 6, and three periods of incision coinciding with MIS 1, 3, and likely 5e. At the Sfakia fan, rapid aggradation occurred during MIS 2 and 4, followed by incision during MIS 1. Nearby climate and vegetation records show that MIS 2, 4, and 6 stadials were characterized by cold and dry climates with sparse vegetation, whereas forest cover and more humid conditions prevailed during MIS 1, 3, and 5. Our data thus suggest that past changes in climate had little effect on landscape-wide denudation rates but exerted a strong control on the aggradation–incision behaviour of alluvial channels on Crete. During glacial stages, we attribute aggradation to hillslope sediment release promoted by reduced vegetation cover and decreased runoff; conversely, incision occurred during relatively warm and wet stages due to increased runoff. In this landscape, past hydroclimate variations outcompeted changes in sediment supply as the primary driver of alluvial deposition and incision