23 research outputs found
Coronal Fe XIV Emission During the Whole Heliosphere Interval Campaign
Solar Cycle 24 is having a historically long and weak start. Observations of
the Fe XIV corona from the Sacramento Peak site of the National Solar
Observatory show an abnormal pattern of emission compared to observations of
Cycles 21, 22, and 23 from the same instrument. The previous three cycles have
shown a strong, rapid "Rush to the Poles" (previously observed in polar crown
prominences and earlier coronal observations) in the parameter N(t,l,dt)
(average number of Fe XIV emission features per day over dt days at time t and
latitude l). Cycle 24 displays a weak, intermittent, and slow "Rush" that is
apparent only in the northern hemisphere. If the northern Rush persists at its
current rate, evidence from the Rushes in previous cycles indicates that solar
maximum will occur in early 2013 or late 2012, at least in the northern
hemisphere. At lower latitudes, solar maximum previously occurred when the time
maximum of N(t,l,365) reached approximately 20{\deg} latitude. Currently, this
parameter is at or below 30{\deg}and decreasing in latitude. Unfortunately, it
is difficult at this time to calculate the rate of decrease in N(t,l,365).
However, the southern hemisphere could reach 20{\deg} in 2011. Nonetheless,
considering the levels of activity so far, there is a possibility that the
maximum could be indiscernibleComment: 8 pages, 4 figures; Solar Physics Online First, 2011
http://www.springerlink.com/content/b5kl4040k0626647
Tetrahydrofurandiols (THF-diols), Leukotoxindiols (LTX-diols), and Endocrine Disruption in Rats
BACKGROUND: Ground corncob animal bedding and corn food products contain substances that disrupt endocrine function in rats. The disruptors were identified as isomeric mixtures of tetrahydrofurandiols (THF-diols; 9,12-oxy-10,13-dihydroxyoctadecanoic acid and 10,13-oxy-9,12-dihydroxyoctadecanoic acid) and leukotoxindiols (LTX-diols; 9,10-dihydroxy-12-octadecenoic acid and 12,13-dihydroxy-9-octadecenoic acid). The authentic compounds blocked sexual behavior in male rats and estrous cyclicity in female rats at oral doses of 2 ppm. OBJECTIVES: To define the lowest observed adverse effect level (LOAEL) for the THF-diols and LTX-diols in rats, we examined the nature of their interaction (additive or synergistic) and quantified the concentration of THF-diols in rat tissues. METHODS: Adult male and female rats were provided drinking solutions containing various doses of THF-diols and/or LTX-diols, and we evaluated their effects on male sexual behavior and female estrous cyclicity. Tissues were collected for THF-diol determination by gas chromatographyāmass spectrometry. RESULTS: The LOAEL for THF-diols and LTX-diols for blocking estrous cyclicity was 0.5ā1.0 ppm and 0.2ā0.5 ppm, respectively. Higher concentrations (1ā2 ppm) of THF-diols were required to block male sexual behavior. Combination studies with subthreshold doses of 0.05 ppm THF-diols plus 0.05 ppm LTX-diols revealed that their effects on estrous cyclicity were not synergistic. We were unable to detect THF-diols in tissues from rats treated with 10 ppm of the compounds, suggesting that metabolism may be involved. DISCUSSION: THF-diols, LTX-diols, and/or their metabolites likely act additively to disrupt endocrine function in male and female rats at concentrations (0.5ā1 ppm) that are 200-fold lower than those of classical phytoestrogen endocrine disruptors
#DĀ Mesonet: Pre/Post Operations Inspection
Steven Trellis; Aerospace Engineering; [email protected].
Faculty mentor: Elizabeth PillarāLittle; School of Meteorology; [email protected]
Effects of THF-diols on the estrous cycle of adult female Holtzman rats treated with vehicle (controls) or various doses (0
<p><b>Copyright information:</b></p><p>Taken from "Tetrahydrofurandiols (THF-diols), Leukotoxindiols (LTX-diols), and Endocrine Disruption in Rats"</p><p></p><p>Environmental Health Perspectives 2007;115(5):702-708.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1868002.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p>2, 0.5, or 1 ppm) of approximately 1:1 mixture of THF-diol isomers. See āMaterials and Methodsā for details. Of the vehicle controls, 100% (8/8) displayed normal (5ā7 day) cycles, whereas cyclicity was suppressed in the 0.2-ppm (75% normal cycles; 6/8 rats), 0.5-ppm (87.5% normal cycles; 7/8), and 1.0-ppm (22% normal cycles; 2/9 rats) treatment groups. Four rats in the 1.0-ppm group displayed a single estrus smear during the 30-day period
Tetrahydrofurandiols (THF-diols), Leukotoxindiols (LTX-diols), and Endocrine Disruption in Rats-3
<p><b>Copyright information:</b></p><p>Taken from "Tetrahydrofurandiols (THF-diols), Leukotoxindiols (LTX-diols), and Endocrine Disruption in Rats"</p><p></p><p>Environmental Health Perspectives 2007;115(5):702-708.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1868002.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p
Effects of THF-diols on the estrous cycle of adult female Holtzman rats treated with vehicle (controls) or with LTX-diols (0
<p><b>Copyright information:</b></p><p>Taken from "Tetrahydrofurandiols (THF-diols), Leukotoxindiols (LTX-diols), and Endocrine Disruption in Rats"</p><p></p><p>Environmental Health Perspectives 2007;115(5):702-708.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1868002.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p>2, 0.5, or 1.0 ppm; doseāresponse study) or LTX-diols plus THF-diols (0.05 ppm each; combination study) as described in āMaterials and Methods.ā The data for the doseāresponse study are also summarized in . Data for the combination study are summarized in
Tetrahydrofurandiols (THF-diols), Leukotoxindiols (LTX-diols), and Endocrine Disruption in Rats-8
<p><b>Copyright information:</b></p><p>Taken from "Tetrahydrofurandiols (THF-diols), Leukotoxindiols (LTX-diols), and Endocrine Disruption in Rats"</p><p></p><p>Environmental Health Perspectives 2007;115(5):702-708.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1868002.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p
Tetrahydrofurandiols (THF-diols), Leukotoxindiols (LTX-diols), and Endocrine Disruption in Rats-4
<p><b>Copyright information:</b></p><p>Taken from "Tetrahydrofurandiols (THF-diols), Leukotoxindiols (LTX-diols), and Endocrine Disruption in Rats"</p><p></p><p>Environmental Health Perspectives 2007;115(5):702-708.</p><p>Published online 29 Jan 2007</p><p>PMCID:PMC1868002.</p><p>This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original DOI</p