Dinoflagellate contributions to the deep sea

For the first time, sediment trap samples from several depths in the deep sea were analyzed to estimate both the types and amounts of mineral contributed by dinoflagellates to the deep sea sediment flux. Thecal remains of dinoflagellate motile stages were almost entirely restricted to the upper few hundred meters of the water column, supporting the generally accepted explanation of their absence in the fossil record (i.e., theca are composed of cellulosic material which is destroyed before they may be incorporated into bottom sediments). The main contribution to the sediment flux is composed of resting cysts routinely produced in the life cycles of just a few of the more obscure oceanic dinoflagellates, probably species of Scrippsiella or Ensiculifera. The cyst assemblage sedimenting out from plankton at present is overwhelmingly dominated by a few small calcareous types (up to several thousands/m2/day). If not dissolved, these may accumulate in paleontologically significant amounts in bottom sediments to give the most representative fossil record of oceanic dinoflagellates. "Oceanic assemblages" of organic-walled cysts from Recent deep-sea sediments previously described by palynologists probably represent long distance transport from more coastal regions rather than oceanic dinoflagellate production

Conversion of a non-selective adenosine receptor antagonist into A3-selective high affinity fluorescent probes using peptide-based linkers

Advances in fluorescence-based imaging technologies have helped propel the study of real-time biological readouts and analysis across many different areas. In particular the use of fluorescent ligands as chemical tools to study proteins such as G protein-coupled receptors (GPCRs) has received ongoing interest. Methods to improve the efficient chemical synthesis of fluorescent ligands remain of paramount importance to ensure this area of bioanalysis continues to advance. Here we report conversion of the non-selective GPCR adenosine receptor antagonist Xanthine Amine Congener into higher affinity and more receptor subtype-selective fluorescent antagonists. This was achieved through insertion and optimisation of a dipeptide linker between the adenosine receptor pharmacophore and the fluorophore. Fluorescent probe 27 containing BODIPY 630/650 (pKD = 9.12 ± 0.05 [hA3AR]), and BODIPY FL-containing 28 (pKD = 7.96 ± 0.09 [hA3AR]) demonstrated clear, displaceable membrane binding using fluorescent confocal microscopy. From in silico analysis of the docked ligand-receptor complexes of 27, we suggest regions of molecular interaction that could account for the observed selectivity of these peptide-linker based fluorescent conjugates. This general approach of converting a non-selective ligand to a selective biological tool could be applied to other ligands of interest

CXCL17 is an allosteric inhibitor of CXCR4 through a mechanism of action involving glycosaminoglycans

CXCL17 is a chemokine principally expressed by mucosal tissues, where it facilitates chemotaxis of monocytes, dendritic cells, and macrophages and has antimicrobial properties. CXCL17 is also implicated in the pathology of inflammatory disorders and progression of several cancers, and its expression is increased during viral infections of the lung. However, the exact role of CXCL17 in health and disease requires further investigation, and there is a need for confirmed molecular targets mediating CXCL17 functional responses. Using a range of bioluminescence resonance energy transfer (BRET)–based assays, here we demonstrated that CXCL17 inhibited CXCR4-mediated signaling and ligand binding. Moreover, CXCL17 interacted with neuropillin-1, a VEGFR2 coreceptor. In addition, we found that CXCL17 only inhibited CXCR4 ligand binding in intact cells and demonstrated that this effect was mimicked by known glycosaminoglycan binders, surfen and protamine sulfate. Disruption of putative GAG binding domains in CXCL17 prevented CXCR4 binding. This indicated that CXCL17 inhibited CXCR4 by a mechanism of action that potentially required the presence of a glycosaminoglycan-containing accessory protein. Together, our results revealed that CXCL17 is an endogenous inhibitor of CXCR4 and represents the next step in our understanding of the function of CXCL17 and regulation of CXCR4 signaling

The dinoflagellate cyst genera Achomosphaera Evitt 1963 and Spiniferites Mantell 1850 in Pliocene to modern sediments: a summary of round table discussions

Source at https://doi.org/10.1080/01916122.2018.1465739. We present a summary of two round-table discussions held during two subsequent workshops in Montreal (Canada) on 16 April 2014 and Ostend (Belgium) on 8 July 2015. Five species of the genus Achomosphaera Evitt 1963 and 33 of the genus Spiniferites Mantell 1850 emend. Sarjeant 1970 occuring in Pliocene to modern sediments are listed and briefly described along with remarks made by workshop participants. In addition, several holotypes and topotypes are reillustrated. Three species previously assigned to Spiniferites are here considered/accepted as belonging to other genera: Impagidinium inaequalis (Wall and Dale in Wall et al.1973) Londeix et al. 2009, Spiniferites? rubinus (Rossignol 1962 ex Rossignol 1964) Sarjeant 1970, and Thalassiphora balcanica Baltes ̧ 1971. This summary forms the basis for a set of papers that follows, where points raised during the workshops are explored in greater detail

Sulfur isotope evolution in sulfide ores from Western Alps: Assessing the influence of subduction-related metamorphism

Sulfides entering subduction zones can play an important role in the release of sulfur and metals to the mantle wedge and contribute to the formation of volcanic arc-associated ores. Fractionation of stable sulfur isotopes recorded by sulfides during metamorphism can provide evidence of fluid-rock interactions during metamorphism and give insights on sulfur mobilization. A detailed microtextural and geochemical study was performed on mineralized samples from two ocean floor-related sulfide deposits (Servette and Beth-Ghinivert) in high-pressure units of the Italian Western Alps, which underwent different metamorphic evolutions. The combination of microtextural investigations with d34S values from in situ ion probe analyses within individual pyrite and chalcopyrite grains allowed evaluation of the effectiveness of metamorphism in modifying the isotopic record and mobilizing sulfur and metals and have insights on fluid circulation within the slab. Textures and isotopic compositions inherited from the protolith are recorded at Beth-Ghinivert, where limited metamorphic recrystallization is attributed to limited interaction with metamorphic fluids. Isotopic modification by metamorphic processes occurred only at the submillimeter scale at Servette, where local interactions with infiltrating hydrothermal fluid are recorded by metamorphic grains. Notwithstanding the differences recorded by the two deposits, neither underwent intensive isotopic reequilibration or records evidence of intense fluid-rock interaction and S mobilization during metamorphism. Therefore, subducted sulfide deposits dominated by pyrite and chalcopyrite are unlikely to release significant quantities of sulfur to the mantle wedge and to arc magmatism sources at metamorphic grades below the lower eclogite facies

Gender and release from imprisonment: Convict licensing systems in mid to late 19th century England

This paper draws on the research undertaken into the lives and prison experiences of around 650 male and female convicts who were released on licence (an early form of parole) from sentences of long term imprisonment (three years to life) in England in the mid- to late-nineteenth century. Our project confirmed the patterns of offending seen in other studies of female and male offending, namely, that women were committed to periods of long-term imprisonment overwhelmingly for crimes of larceny and sometimes low-level violence (or their criminal backgrounds indicated this type of low-level disorderly behaviour) and only in the minority for crimes of serious interpersonal violence. Similarly, the majority of men were also committed to the convict system for larceny. Yet how male and female offenders were treated by the prison licensing system did differ significantly. The vast majority of all prisoners, male and female, were released early on licence from their prison terms, even those who had committed very serious offences. All licences had several conditions in them and licence-holders were free so long as they met these conditions. Any breach of the above conditions meant that the individual would be returned to prison to serve out the remainder of their sentence.However, a proportion of female offenders were released slightly earlier than their male counterparts, though not directly into the community but on a conditional licence to Female Refuges. Out of the 288 women researched in our project, 200 of them were released in this manner; under further confinement in a refuge. Women stayed in such refuges for on average between six and nine months, before their final release was then approved by the Directors of the Convict Prisons

"Monstrous and indefensible"? Newspaper accounts of sexual assaults on children in nineteenth-century England and Wales

This material has been published in Women's Criminality in Europe, 1600–1914 edited by Edited by Manon van der Heijden, Marion Pluskota, Sanne Muurling, https://doi.org/10.1017/9781108774543. This version is free to view and download for private research and study only. Not for re-distribution or re-use. © 2020 Cambridge University Press.Popular crime reportage of sexual violence has a long history in England. Despite the fact that from the 1830s onwards newspapers and periodicals – and sometimes even law reports – were increasingly liable to skim over the reporting of sexual offences as ‘unfit for publication’, this does not mean that such reportage vanished entirely. Instead, certain linguistic codes and euphemisms were invoked to maintain a respectable discourse. Given the serious problems with gaps in the surviving archival record for modern criminal justice, newspapers remain an essential tool for understanding the history of sexual violence in nineteenth century England and Wales. Using keyword searches in digitized newspaper databases such as the British Newspaper Archive and Welsh Newspapers Database, this chapter examines the continuities and changes in the reporting of sexual violence against children between 1800 and 1900, and explores what these euphemisms and elisions reveal about attitudes to gender and crime in nineteenth-century England and Wales.Peer reviewe

The sedimentary record of dinoflagellate cysts: looking back into the future of phytoplankton blooms

Marine systems are not as well understood as terrestrial systems, and there is still a great need for more primary observations, in the tradition of the old-time naturalists, before newer methods such as molecular genetics and modeling can be fully utilized. The scientific process whereby the smaller, detailed building blocks of observation are ultimately linked towards better understanding natural systems is illustrated from my own career experience, especially with regard to the dinoflagellates and plankton blooms. Some dinoflagellates produce a fossilizable resting stage (cyst) in their life cycle, and dinoflagellate cysts have become one of the most important groups of microfossils used in geological exploration (e.g. oil and gas). This has stimulated both paleontological and biological research producing detailed building blocks of information, currently scattered throughout the respective literature. Here, I attempt to bring together the present day perspective, from biology, with the past, from paleontology, as the most comprehensive basis for future work on the group. This shows the cysts to be the critical link needed for focusing future molecular genetics studies towards a more verifiable view of evolutionary pathways, and it also suggests new integrated methods for studying past, present, and future blooms. The large, rapidly growing field of harmful algal bloom studies is producing many different building blocks, but plankton blooms as episodic phenomena are still poorly understood. This is largely due to the general lack of long-term datasets allowing identification of the changing environmental factors that permit certain species to bloom at unpredictable intervals of time. Cysts in sediments are useful environmental indicators today, e.g. reflecting aspects of climate and pollution, and provide information directly relevant to some dinoflagellate blooms. They therefore may be used for obtaining retrospective information from the sedimentary record on the history of blooms, in turn suggesting information relevant for future blooms and the way we study them.No disponible

From hystrichospheres to dinoflagellate cysts: Scandinavian contributions to Evitt’s pivotal recognition of fossil dinoflagellate cysts

As one of the remaining living links with two early Scandinavian researchers, the author examines their contribution to Bill Evitt’s breakthrough that launched the development of fossil dinoflagellate cysts into palynology. Evitt, in the early 1960s, revealed that many fossil hystrichospheres were in fact dinoflagellate cysts. Trygve Braarud, a Norwegian phytoplankton biologist, and Gunnar Erdtman, a Swedish palynologist, collaborated in 1954 to identify the first examples of living hystrichospheres as dinoflagellate cysts. This and a related study by the Norwegian Erling Nordli provided important evidence for Evitt’s breakthrough in 1961, but the wider palynological literature does not yet reflect the full significance of the Scandinavian work. Copies of correspondence between Braarud and Erdtman reproduced here together with the author’s personal observations help to clarify the extent to which this earlier work influenced the breakthrough. The Scandinavians were not aware at the time of the wider significance of their work for palynology, realized only later through Evitt’s perception. Reexamining this Scandinavian connection now therefore in no way detracts from Evitt’s pivotal role in launching ‘dinos’ into palynology. This example from palynology shows details of how exciting breakthroughs in science often happen, as work in separate but related fields is coalesced into a larger, more significant concept