340 resultados para ATS


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Strontium isotope ratios from multiple plates of two barnacle fragments from Site 1103 (Ocean Drilling Program Leg 178) provide maximum age estimates for the oldest glacial sedimentary package drilled. Three moderately preserved barnacle fragments from 262.63 meters below seafloor (mbsf) yielded a mean best-fit age of 7.4 Ma. A single, well-preserved fragment from the same horizon yielded a best-fit age of 12.2 Ma. Two moderately preserved fragments from 262.98 mbsf yielded a mean best-fit age of 7.8 Ma. The calculated mean strontium ages of 7.8 and 7.4 Ma agree well with the diatom estimates of 8.68 to 5.89 Ma for the underlying sediments.

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Continuous sediment color records with a resolution of one measurement per millimeter were generated for Site 1098 (Palmer Deep, Antarctic Peninsula) from digital images of the core surfaces to test if the laminated intervals at this site will allow for analysis of high-frequency climate variability in the Circum-Antarctic. Long-term variation in color values correlates with gamma-ray attenuation bulk density. Darker colors are found in laminated intervals with lower bulk density, high biogenic silica, and high total organic carbon content. Darker color values result from the addition of dark laminae to background sediments that show little variation in color. The thicknesses of dark and light laminae were measured in the top 25 meters composite depth to determine the temporal resolution of the laminae. The alternation between dark, biogenic-rich laminae and background sediment essentially represents an annual cycle, but the sediment is not consistently varved. The modal thickness of light laminae is close to the long-term average annual accumulation rate, and results indicate that approximately half of the dark/light couplets in distinctly laminated intervals represent a single year. Missing biogenic laminae are interpreted to represent reduced primary productivity during cold years with delayed breakup of the sea-ice cover.

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Magnetic field strength and magnetic susceptibility were logged with the geological high-resolution magnetic tool (GHMT) at three of the holes drilled during Ocean Drilling Program Leg 178 to the west of the Antarctic Peninsula. Polarity stratigraphies derived from the GHMT logs bear close resemblance to the polarities determined from core paleomagnetism at two of the holes and were used for magnetostratigraphic dating, especially in intervals where no core was recovered. Polarity is determined in the following way. First, the susceptibility log is used to determine the induced magnetization of the sediment. Then the background field, the field of the metal drill pipe, and the field anomaly of the sediment's induced magnetization are removed from the measured total field to leave the downhole anomaly of the sediment's remanent magnetization. The sign (positive or negative) of this anomaly gave a good polarity stratigraphy for Holes 1095B and 1096C, which are located in sediment drifts. A further step, correlation analysis, is based on the fact that in an interval of normal polarity sediment the remanent anomaly will correlate with the induced anomaly, whereas in reversed polarity sediment they will anticorrelate. The magnetite-rich, fine-grained sediments found in the two holes drilled into the sediment drift have a ratio of remanent to induced magnetization (the Koenigsberger ratio) of ~1. In contrast, the coarser-grained diamict sediments on the shelf have a Koenigsberger ratio of ~0.2, and extracting the remanent part of the downhole anomaly is much more difficult. By the comparison of core and log results, we can assess the viability of the GHMT polarities in detail, what proportion of the overprint in the cores is imparted by the coring process, and whether any paleointensity information is extractable from the GHMT logs.

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Detailed study of four Holocene sediment intervals from Ocean Drilling Program Site 1098 (Palmer Deep, Antarctic Peninsula) reveals that in situ dissolution of calcareous foraminifers in the core repository has significantly altered and in some cases eliminated calcareous foraminifers. Despite dissolution, the foraminifer and supporting diatom data show that the most open-ocean and reduced sea-ice conditions occurred in the early Holocene. The influence of Circumpolar Deep Water was greatest during the early Holocene but continued to be important throughout the Holocene. An increase in sea-ice proximal diatoms at 3500 cal. BP documents an expansion in the amount of persistent sea ice. The inferred increase in sea ice corresponds with an overall increase in magnetic susceptibility values. Benthic foraminifers are present in all samples from the Palmer Deep, including the middle Holocene pervasively laminated sediments with low magnetic susceptibility values. The consistent presence of mobile epifaunal benthic foraminifers in the laminated sediments demonstrates that the laminations do not represent anoxic conditions. The uniform composition of the agglutinated foraminifer fauna throughout the late Holocene suggests that the Palmer Deep did not experience bottom-water-mass changes associated with the alternating deposition of bioturbated or laminated sediments.

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BACKGROUND Arrhythmias in cardiac amyloidosis (CA) result in significant comorbidity and mortality but have not been well characterized. OBJECTIVE The purpose of this study was to define intracardiac conduction, atrial arrhythmia substrate, and ablation outcomes in a group of advanced CA patients referred for electrophysiologic study. METHODS Electrophysiologic study with or without catheter ablation was performed in 18 CA patients. Findings and catheter ablation outcomes were compared to age- and gender-matched non-CA patients undergoing catheter ablation of persistent atrial fibrillation (AF). RESULTS Supraventricular tachycardias were seen in all 18 CA patients (1 AV nodal reentrant tachycardia, 17 persistent atrial tachycardia [AT]/AF). The HV interval was prolonged (>55 ms) in all CA patients, including 6 with normal QRS duration (≤100 ms). Thirteen supraventricular tachycardia ablations were performed in 11 patients. Of these, 7 underwent left atrial (LA) mapping and ablation for persistent AT/AF. Compared to non-CA age-matched comparator AF patients, CA patients had more extensive areas of low-voltage areas LA (63% ± 22% vs 34% ± 22%, P = .009) and a greater number of inducible ATs (3.3 ± 1.9 ATs vs 0.2 ± 0.4 ATs, P <.001). The recurrence rate for AT/AF 1 year after ablation was greater in CA patients (83% vs 25%), and the hazard ratio for postablation AT/AF recurrence in CA patients was 5.4 (95% confidence interval 1.9-35.5, P = .007). CONCLUSION In this group of patients with advanced CA and atrial arrhythmias, there was extensive conduction system disease and LA endocardial voltage abnormality. Catheter ablation persistent AT/AF in advanced CA was associated with a high recurrence rate and appears to have a limited role in control of these arrhythmias.

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Haṛajabanutʻiwn -- Epiphaniou Peri metrōn kai stathmōn = Epipʻanu Haghags chʻaputsʻ ew kshṛotsʻ -- Anania Shirakunoy hamaroghi Haghags kshṛotsʻn ew chʻapʻutsʻ -- Movsisi Khorenatsʻwoy Haghags asparisakan chʻapʻu -- Haghags ěntʻatsʻitsʻ aregakan ew hamaroy chʻapʻutsʻ ěst krkin ōrinakatsʻ Shirakatsʻwoyn -- Batsʻatrutʻiwn chʻapʻuts ew kshṛotsʻ nakhneatsʻ -- Ard i chʻapʻkʻ ew kshiṛkʻ Gaghghiatsʻwotsʻ -- Aṛandzin dasakargutʻiwn kshṛotsʻ ew chʻapʻutsʻ handerdz tachkakan baṛiwkʻ.

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Introduction aux tomes III et IV (fonds Et́ats du duche d́e Bourgogne) par Joseph Garnier. Dijon, Imp. Bernigaud et Privat, 1959" (lvi p.) inserted at beginning of t.3.

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Objective - To investigate whether artificial tears and cold compress alone or in combination provide a treatment benefit and whether they were as effective as or could enhance topical antiallergic medication. Design - Randomized, masked clinical trial. Participants - Eighteen subjects (mean age, 29.5±11.0 years) allergic to grass pollen. Intervention - Controlled exposure to grass pollen using an environmental chamber to stimulate an ocular allergic reaction followed by application of artificial tears (ATs), 5 minutes of cold compress (CC), ATs combined with CC, or no treatment applied at each separate visit in random order. A subset of 11 subjects also had epinastine hydrochloride (EH) applied alone and combined with CC in random order or instillation of a volume-matched saline control. Main Outcome Measures - Bulbar conjunctival hyperemia, ocular surface temperature, and ocular symptoms repeated before and every 10 minutes after treatment for 1 hour. Results - Bulbar conjunctival hyperemia and ocular symptoms decreased and temperature recovered to baseline faster with nonpharmaceutical treatments compared with no treatment (P?ATs or EH lowered the antigen-raised ocular surface temperature to less than the pre-exposure baseline. Artificial tear instillation alone or CC combined with ATs or EH significantly reduced the temperature (P?ATs or EH had a similar cooling effect (P?>?0.05). At all measurement intervals, symptoms were reduced for both EH and EH combined with CC than CC or ATs alone or in combination (P?ATs or EH.