400 research outputs found
Prenatal Exposure to Tetrachloroethylene-Contaminated Drinking Water and the Risk of Congenital Anomalies: A Retrospective Cohort Study
BACKGROUND: Prior animal and human studies of prenatal exposure to solvents including tetrachloroethylene (PCE) have shown increases in the risk of certain congenital anomalies among exposed offspring. OBJECTIVES: This retrospective cohort study examined whether PCE contamination of public drinking water supplies in Massachusetts influenced the occurrence of congenital anomalies among children whose mothers were exposed around the time of conception. METHODS: The study included 1,658 children whose mothers were exposed to PCE-contaminated drinking water and a comparable group of 2,999 children of unexposed mothers. Mothers completed a self-administered questionnaire to gather information on all of their prior births, including the presence of anomalies, residential histories and confounding variables. PCE exposure was estimated using EPANET water distribution system modeling software that incorporated a fate and transport model. RESULTS: Children whose mothers had high exposure levels around the time of conception had an increased risk of congenital anomalies. The adjusted odds ratio of all anomalies combined among children with prenatal exposure in the uppermost quartile was 1.5 (95% CI: 0.9, 2.5). No meaningful increases in the risk were seen for lower exposure levels. Increases were also observed in the risk of neural tube defects (OR: 3.5, 95% CI: 0.8, 14.0) and oral clefts (OR 3.2, 95% CI: 0.7, 15.0) among offspring with any prenatal exposure. CONCLUSION: The results of this study suggest that the risk of certain congenital anomalies is increased among the offspring of women who were exposed to PCE-contaminated drinking water around the time of conception. Because these results are limited by the small number of children with congenital anomalies that were based on maternal reports, a follow-up investigation should be conducted with a larger number of affected children who are identified by independent records.National Institute of Environmental Health (5 P42 ES007381); National Institutes of Healt
Limitations of Boulder Detection in Shallow Water Habitats Using High-Resolution Sidescan Sonar Images
Stones and boulders in shallow waters (0â10 m water depth) form complex geo-habitats,
serving as a hardground for many benthic species, and are important contributors to coastal
biodiversity and high benthic production. This study focuses on limitations in stone and boulder
detection using high-resolution sidescan sonar images in shallow water environments of the
southwestern Baltic Sea. Observations were carried out using sidescan sonars operating with
frequencies from 450 kHz up to 1 MHz to identify individual stones and boulders within different levels
of resolution. In addition, sidescan sonar images were generated using varying survey directions for
an assessment of range effects. The comparison of images of different resolutions reveals considerable
discrepancies in the numbers of detectable stones and boulders, and in their distribution patterns.
Results on the detection of individual stones and boulders at approximately 0.04 m/pixel resolution
were compared to common discretizations: it was shown that image resolutions of 0.2 m/pixel may
underestimate available hard-ground settlement space by up to 42%. If methodological constraints
are known and considered, detailed information about individual stones and boulders, and potential
settlement space for marine organisms, can be derived
Structure and antagonism of the receptor complex mediated by human TSLP in allergy and asthma
The pro-inflammatory cytokine thymic stromal lymphopoietin (TSLP) is pivotal to the pathophysiology of widespread allergic diseases mediated by type 2 helper T cell (Th2) responses, including asthma and atopic dermatitis. The emergence of human TSLP as a clinical target against asthma calls for maximally harnessing its therapeutic potential via structural and mechanistic considerations. Here we employ an integrative experimental approach focusing on productive and antagonized TSLP complexes and free cytokine. We reveal how cognate receptor TSLPR allosterically activates TSLP to potentiate the recruitment of the shared interleukin 7 receptor a-chain (IL-7Ra) by leveraging the flexibility, conformational heterogeneity and electrostatics of the cytokine. We further show that the monoclonal antibody Tezepelumab partly exploits these principles to neutralize TSLP activity. Finally, we introduce a fusion protein comprising a tandem of the TSLPR and IL-7Ra extracellular domains, which harnesses the mechanistic intricacies of the TSLP-driven receptor complex to manifest high antagonistic potency
Dynamics of Stone Habitats in Coastal Waters of the Southwestern Baltic Sea (Hohwacht Bay)
Cobbles and boulders on the seaïŹoor are of high ecological value in their function as
habitats for a variety of benthic species, contributing to biodiversity and productivity in marine
environments. We investigate the origin, physical shape, and structure of habitat-forming cobbles
and boulders and reïŹect on their dynamics in coastal environments of the southwestern Baltic
Sea. Stone habitats are not limited to lag deposits and cannot be sufïŹciently described as static
environments, as different dynamic processes lead to changes within the physical habitat structure
and create new habitats in spatially disparate areas. Dynamic processes such as (a) ongoing exposure
of cobbles and boulders from glacial till, (b) continuous overturning of cobbles, and (c) the migration
of cobbles need to be considered. A distinction between allochthonous and autochthonous habitats is
suggested. The genesis of sediment types indicates that stone habitats are restricted to their source
(glacial till), but hydrodynamic processes induce a redistribution of individual cobbles, leading to
the development of new coastal habitats. Thus, coastal stone habitats need to be regarded as dynamic
and are changing on a large bandwidth of timescales. In general, wave-induced processes changing
the physical structure of these habitats do not occur separately but rather act simultaneously, leading
to a dynamic type of habitat
XMM-Newton Observations of a Complete Sample of Optically Selected Type 2 Seyfert Galaxies
(abridged)The majority of Active Galactic Nuclei (AGN) suffer from
significant obscuration by surrounding dust and gas. X-ray surveys in the 2-10
keV band will miss the most heavily-obscured AGN in which the absorbing column
density exceeds cm (the Compton-thick AGN). It is therefore
vital to know the fraction of AGN that are missed in such X-rays surveys and to
determine if these AGN represent some distinct population in terms of the
fundamental properties of AGN and/or their host galaxies. In this paper we
present the analysis of \textit{XMM-Newton} X-ray data for a complete sample of
17 low-redshift Type 2 Seyfert galaxies chosen from the Sloan Digital Sky
Survey based solely on the high observed flux of the [OIII]5007
emission-line. This line is formed in the Narrow Line Region hundreds of
parsecs away from the central engine. Thus, unlike the X-ray emission, it is
not affected by obscuration due to the torus surrounding the black hole. It
therefore provides a useful isotropic indicator of the AGN luminosity. As
additional indicators of the intrinsic AGN luminosity, we use the Spitzer Space
Telescope to measure the luminosities of the mid-infrared continuum and the
[OIV]25.89m narrow emission-line. We then use the ratio of the 2-10 keV
X-ray luminosity to the [OIII], [OIV], and mid-infrared luminosities to assess
the amount of X-ray obscuration and to distinguish between Compton-thick and
Compton-thin objects. We find that the majority of the sources suffer
significant amounts of obscuration: the observed 2-10 keV emission is depressed
by more than an order-of-magnitude in 11 of the 17 cases (as expected for
Compton-thick sources).Comment: accepted for publication to ApJ; 48 pages, 15 figure
Prize papers as new sources for maritime historical research: The circulation of knowledge on the sea
The Prize Papers Collection, preserved at the National Archives (Kew, England), contains documents captured from enemy ships by the British Navy during the War of Spanish Succession (1702-1714). Those Papers relating to Southern Netherlandish ships and sailors have been previously unexplored, and offer new perspectives on the early modern maritime history of the North Sea area. Historical research and transcription of these sources, and in particular sailorsâ correspondence, allow us to examine two ways in which the sea was considered as a resource: this concerns the use of fish as an on-board food source and commodity, as well as the knowledge of ways in which the sea itself served as a resource, in terms of navigational strategies offered by currents, climatic conditions, and sea routes.
A series of selected case studies allow us to look at direct strategies of resource use from the perspective of the sea itself, and from the transient vantage point of the ship and its sailors. This reveals how certain privateering strategies and navigational tactics were enabled by the circulation of expert knowledge within a shared socio-cultural environment formed by maritime communities in the closely related ports of Ostend and Dunkirk.
By means of letters, cargo lists, and lists of victuals, research on the use of fish as a resource reveals how types of sea fish such as herring, âmudfishâ and codfish were either caught and used as a shipboard food source, or transported in order to serve as commodities. This was the case for oysters from Le Croisicq, or salted fish such as Mediterranean anchovy or North Sea herring. The provenance of the sources bearing witness to such cargo shows that fish as commodities were deemed valuable enough to warrant the Southern Netherlandish shipsâ hijacking by the rival British Navy or the Guernsey-Jersey privateers.
From shipboard correspondence on the use of the sea and its climatic conditions as a resource for navigational strategies, it is clear such specialist knowledge circulated primarily among privateers, who used this to their advantage in order to hijack and ransom rival ships and captains. Specific instructions probably circulated in both oral and written form, showing joint operations between Ostend and Dunkirk privateers towards areas such as the Dogger Bank or the Scottish seas. The considerable social mobility of sailor communities between both ports of Ostend and Dunkirk would have facilitated such exchanges and their required communication. Those communities apt at using navigational knowledge and making use of specific sea routes often sailed with smaller vessels such as snauw or dogger ships, which could also be involved in fishing. This implies fishing communities from Ostend, who would have had good knowledge of the sea as a strategic and navigational resource through their fishing experience, may have turned to privateering as a lucrative pursuit during wartime. On the North Sea coast, Dunkirk served as a main base for such privateering, although many crews comprised Ostend sailors and captains as well.
The research project on 18th century Southern Netherlandish Prize Papers forms a new line of historical research within the VLIZ (Flanders Marine Institute), initiated with support of the COST Oceans Past Platform and in collaboration with The National Archives (Kew). It opens up research into previously unknown sources on Southern Netherlandish Maritime history, and has wide research potential to link up with e.g. research on transnational economical networks, socio-cultural conditions of sailors, and strategies of commerce and privateering under early 18th century wartime conditions. It aims to be a collaborative project constructing research partnerships within a wider network
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