340 research outputs found
Reports of injury risks and reasons for choice of sleep environments for infants and toddlers
OBJECTIVE: Compare mothers\u27 reports of injuries for infants and toddlers sleeping with crib-bumpers/mesh-liners/no-barriers and reasons for these sleep environment choices.
METHODS: A cross-sectional survey of mothers subscribing to a parenting magazine and using crib bumpers (n = 224), mesh liners (n = 262), and no barriers (n = 842). Analyses of four possible injuries (face-covered, climb-out/fall, slat-entrapment, hit-head) including multivariate logistic regression adjusted for missing data/demographics and Chi squared analyses of reasons for mothers\u27 choices.
RESULTS: Maternal reports of finding infants/toddlers with face covered had 3.5 times higher adjusted odds (aOR) for crib bumper versus mesh liner use. Breathing difficulties and wedgings were reported for infants/toddlers using crib bumpers but not mesh liners. Climb-outs/falls showed no significant difference in aORs for crib bumpers versus no-barriers and mesh liners versus no barriers. Reports of slat-entrapment were less likely for mothers using crib bumpers and mesh liners than using no barrier (aOR = .28 and .32). Reports of hit-heads were less likely for crib bumpers vs no barrier (aOR = .38) with no significant difference between mesh liners versus no barrier use. Mothers using crib bumpers and mesh liners felt their choice prevented slat-entrapment (89%, 91%); 93.5% of crib bumper users felt their choice prevented hit-heads. Significantly more mesh liner than crib bumper users chose them because There is no suffocation risk (64.1% vs. 40.6%), while 83.6% of no-barrier users chose them because I was concerned about suffocation risk.
CONCLUSIONS FOR PRACTICE: Mothers appeared to be more concerned about preventing minor risks than suffocation. Understanding reasons for mothers\u27 use of barriers/no-barriers is important in tailoring counseling for mothers with infants/toddlers
Short-wavelength out-of-band EUV emission from Sn laser-produced plasma
We present the results of spectroscopic measurements in the extreme
ultraviolet (EUV) regime (7-17 nm) of molten tin microdroplets illuminated by a
high-intensity 3-J, 60-ns Nd:YAG laser pulse. The strong 13.5 nm emission from
this laser-produced plasma is of relevance for next-generation nanolithography
machines. Here, we focus on the shorter wavelength features between 7 and 12 nm
which have so far remained poorly investigated despite their diagnostic
relevance. Using flexible atomic code calculations and local thermodynamic
equilibrium arguments, we show that the line features in this region of the
spectrum can be explained by transitions from high-lying configurations within
the Sn-Sn ions. The dominant transitions for all ions but
Sn are found to be electric-dipole transitions towards the =4 ground
state from the core-excited configuration in which a 4 electron is promoted
to the 5 sub-shell. Our results resolve some long-standing spectroscopic
issues and provide reliable charge state identification for Sn laser-produced
plasma, which could be employed as a useful tool for diagnostic purposes.Comment: 11 pages, 4 figure
Respiratie bij vogels: een functioneel-anatomische benadering
The mechanism of avian respiration is still controversial. It is fundamentally different from respiration in mammals. Although during in-and expiration a continuous caudocranial airflow is present within the tertiary bronchi and the air capillaries of the avian lung, the air flow within the entire respiratory system is still equivocal. Several patterns explaining the air flow during in-and expiration have been proposed during the past century. Moreover, various anatomical structures and aerodynamic mechanisms have recently been described in an attempt to explain the proposed mechanisms of respiration. This manuscript gives an overview of the anatomy of the avian respiratory system and the hypotheses concerning the physiology of avian respiration
Ferric citrate and ferric EDTA but not ferrous sulfate drive amphiregulin-mediated activation of the MAP kinase ERK in gut epithelial cancer cells.
Ferric chelates may be used as oral iron supplements or phosphate binders but both ferric citrate and ferric EDTA have been shown to promote tumor burden in murine models of colon cancer. Here we studied their effects on cancer cell growth, at typical supplemental iron levels encountered in the gastrointestinal tract (0.01-0.2 mM). Caco-2 and/or Hutu-80 cells were exposed to these forms of chelated iron or to ferrous sulfate and outcomes were assessed using cell proliferation assays, proteome profiler arrays, western blot, and ELISA. Ferric EDTA and ferric citrate increased cellular levels of the onco-protein amphiregulin and its receptor (EGFr) which in turn stimulated the activation of the MAP kinase ERK. Simultaneously, the expression of the negative Wnt regulator, DKK-1, increased suggesting that cell proliferation through the Wnt pathway may be less pronounced in the presence of ferric EDTA and ferric citrate, unlike for ferrous sulfate. Moreover, ferrous sulfate did not increase levels of cellular amphiregulin or EGFr. We conclude that specific iron compounds affect cell signaling differently and some may increase the risk of colon cancer advancement in an amphiregulin-dependent fashion. Further scrutiny of safe oral iron use is merited
Differential Effects of Iron Chelates vs. Iron Salts on Induction of Pro-Oncogenic Amphiregulin and Pro-Inflammatory COX-2 in Human Intestinal Adenocarcinoma Cell Lines
We previously showed that two iron compounds that are orally ingested by humans, namely ferric EDTA and ferric citrate, can induce an oncogenic growth factor (amphiregulin) in human intestinal epithelial adenocarcinoma cell lines. Here, we further screened these iron compounds, plus four other iron chelates and six iron salts (i.e., 12 oral iron compounds in total), for their effects on biomarkers of cancer and inflammation. Ferric pyrophosphate and ferric EDTA were the main inducers of amphiregulin and its receptor monomer, IGFr1. Moreover, at the maximum iron concentrations investigated (500 \ub5M), the highest levels of amphiregulin were induced by the six iron chelates, while four of these also increased IGfr1. In addition, we observed that ferric pyrophosphate promoted signaling via the JAK/STAT pathway by up-regulating the cytokine receptor subunit IFN-Îłr1 and IL-6. For pro-inflammatory cyclooxygenase-2 (COX-2), ferric pyrophosphate but not ferric EDTA elevated intracellular levels. This, however, did not drive the other biomarkers based on COX-2 inhibition studies and was probably downstream of IL-6. We conclude that of all oral iron compounds, iron chelates may particularly elevate intracellular amphiregulin. Ferric pyrophosphate additionally induced COX-2, probably because of the high IL-6 induction that was observed with this compound
A new perspective on GCRT J1745-3009
Two WSRT observations were performed and five archival VLA data were reduced
in order to redetect the enigmatic radio transient GCRT J1745-3009. The source
was not redetected. We were, however, able to extract important new information
from the discovery dataset. Our reanalysis excludes models that predict
symmetric bursts, but the transient white dwarf pulsar is favoured. Although we
now have more contraints on the properties of this source, we are still unsure
about its basic model.Comment: 11 pages, 5 figure
The LOFAR Transients Pipeline
Current and future astronomical survey facilities provide a remarkably rich
opportunity for transient astronomy, combining unprecedented fields of view
with high sensitivity and the ability to access previously unexplored
wavelength regimes. This is particularly true of LOFAR, a
recently-commissioned, low-frequency radio interferometer, based in the
Netherlands and with stations across Europe. The identification of and response
to transients is one of LOFAR's key science goals. However, the large data
volumes which LOFAR produces, combined with the scientific requirement for
rapid response, make automation essential. To support this, we have developed
the LOFAR Transients Pipeline, or TraP. The TraP ingests multi-frequency image
data from LOFAR or other instruments and searches it for transients and
variables, providing automatic alerts of significant detections and populating
a lightcurve database for further analysis by astronomers. Here, we discuss the
scientific goals of the TraP and how it has been designed to meet them. We
describe its implementation, including both the algorithms adopted to maximize
performance as well as the development methodology used to ensure it is robust
and reliable, particularly in the presence of artefacts typical of radio
astronomy imaging. Finally, we report on a series of tests of the pipeline
carried out using simulated LOFAR observations with a known population of
transients.Comment: 30 pages, 11 figures; Accepted for publication in Astronomy &
Computing; Code at https://github.com/transientskp/tk
EUV spectroscopy of Sn5+-Sn(10+)ions in an electron beam ion trap and laser-produced plasmas
Emission spectra from multiply-charged Sn5+ –Sn10+ions are recorded from an electron beam ion trap (EBIT) and from laser-produced plasma (LPP) in the extreme ultraviolet range relevant for nanolithographic applications. Features in the wavelength regime between 12.6 and 20.8 nm are studied. Using the Cowan code, emission line features of the charge-state-resolved Sn ion spectra obtained from the EBIT are identified. Emission features from tin LPP either from a liquid micro-droplet or planar solid target are subsequently identified and assigned to specific charge states using the EBIT data. For the planar solid tin target, the 4d–5p transitions of Sn8+ –Sn10+ions are shown to dominate the long-wavelength part of the measured spectrum and transitions of type 4d–4f + 4p–4d are visible in absorption. For the droplet target case, a clear increase in the charge state distribution with increasing laser intensity is observed. This qualitatively demonstrates the potential of using long-wavelength out-of-band emission features to probe the charge states contributing to the strong unresolved transition array at 13.5 nm relevant for nanolithography
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