378 research outputs found
Exotic glass types and the intensity of recycling in the northwest Quarter of Gerasa (Jerash, Jordan)
Major and trace elements are presented for 149 glass fragments ranging in date from the Roman to Early Islamic periods (1st – mid-8th centuries CE), excavated during the Danish-German Jerash Northwest Quarter Project's fieldwork between 2011 and 2016. The results confirm a clear dominance of Levantine glass types, but also reveal 12 glasses of Egyptian and Mesopotamian compositions recovered from two houses destroyed by the major earthquake which hit parts of the Levant in January 749 CE. These closed and undisturbed contexts from the final phase of occupation reveal the presence of relatively more pristine Levantine as well as imported material that is less visible in earlier contexts in the Gerasa assemblage, where the recycling indexes are high and chemical signatures of any exotic glass were largely lost due to remelting and their dilution by the overwhelming quantities of glass produced in the Levantine region. This emphasizes that imported glass may frequently be underestimated or even invisible in glass compositional studies, depending on the archaeological context sampled and the approach taken to artifact quantification.
Levantine glass was attributed to Roman, Late Roman (Jalame) and Byzantine/Early Islamic (Apollonia) productions based primarily on MnO, Al_{2}O_{3} and Na_{2}O concentrations, which offered an advantage over previous approaches. While colorants in weakly colored glass indicate recycled material, their concentrations are sensitive to context, with higher concentrations in the early periods when the use of intentionally colored glass was more frequent. We have therefore developed the concept of the intensity of recycling, which was estimated using components modified during prolonged melting, such as K_{2}O, P_{2}O_{5} and Cl. A pronounced enrichment in CaO, also dependent upon the intensity of recycling, may affect the assignment to compositional groups and should be taken into consideration in future. Recycling in Gerasa appears to have been more intensive than was the case for cities closer to the primary production centers on the Mediterranean coast, consistent with the view that the dependency on recycling increases further away from the source of the primary material. In contrast, the cities in the coastal plain could readily exploit the marine transportation network, which appears to have played a major role in the distribution of raw glass
Characterizing the pre-clinical phase of inflammatory bowel disease
Understanding the biological changes that precede a diagnosis of inflammatory bowel disease (IBD) could facilitate pre-emptive interventions, including risk factor modification, but this pre-clinical phase of disease remains poorly characterized. Using measurements from 17 hematological and biochemical parameters taken up to 10 years before diagnosis in over 20,000 IBD patients and population controls, we address this at massive scale. We observe widespread significant changes in multiple biochemical and hematological parameters that occur up to 8 years before diagnosis of Crohn's disease (CD) and up to 3 years before diagnosis of ulcerative colitis. These changes far exceed previous expectations regarding the length of this pre-diagnostic phase, revealing an opportunity for earlier intervention, especially in CD. In summary, using a nationwide, case-control dataset-obtained from the Danish registers-we provide a comprehensive characterization of the hematological and biochemical changes that occur in the pre-clinical phase of IBD.</p
Deuterium toward the WD0621-376 sight line: Results from the Far Ultraviolet Spectroscopic Explorer (FUSE) Mission
Far Ultraviolet Spectroscopic Explorer observations are presented for
WD0621-376, a DA white dwarf star in the local interstellar medium (LISM) at a
distance of about 78 pc. The data have a signal-to-noise ratio of about 20-40
per 20 km/s resolution element and cover the wavelength range 905-1187 \AA.
LISM absorption is detected in the lines of D I, C II, C II*, C III, N I, N II,
N III, O I, Ar I, and Fe II. This sight line is partially ionized, with an
ionized nitrogen fraction of > 0.23. We determine the ratio (2). Assuming a standard interstellar
oxygen abundance, we derive . Using the
value of N(H I) derived from EUVE data gives a similar D/H ratio. The D I/N I
ratio is (2).Comment: accepted for publication in the ApJ
Herschel observations of interstellar chloronium. II - Detections toward G29.96-0.02, W49N, W51, and W3(OH), and determinations of the ortho-to-para and Cl/Cl isotopic ratios
We report additional detections of the chloronium molecular ion, HCl,
toward four bright submillimeter continuum sources: G29.96, W49N, W51, and
W3(OH). With the use of the HIFI instrument on the Herschel Space Observatory,
we observed the transition of ortho-HCl at 781.627
GHz in absorption toward all four sources. Much of the detected absorption
arises in diffuse foreground clouds that are unassociated with the background
continuum sources and in which our best estimates of the ratio lie in the range .
These chloronium abundances relative to atomic hydrogen can exceed the
predictions of current astrochemical models by up to a factor of 5. Toward
W49N, we have also detected the transition of
ortho-HCl at 780.053 GHz and the transition of
para-HCl at 485.418 GHz. These observations imply column density ratios that are consistent with the
solar system Cl/Cl isotopic ratio of 3.1, and chloronium
ortho-to-para ratios consistent with 3, the ratio of spin statistical weights.Comment: 31 pages, including 7 figures. Accepted for publication in the Ap
Copper-based metalwork in Roman to early Islamic Jerash (Jordan): Insights into production and recycling through alloy compositions and lead isotopes
Metallographic, chemical and lead isotopic analyses of copper-based artefacts recovered from the Northwest Quarter in Jerash (ancient Gerasa) in Jordan provide new information on the civic life and material culture from a key urban site in the Roman Empire's eastern provinces. The samples span the city's occupation from its flourishing under Roman rule into the Byzantine and early Islamic periods. We examined 49 copper-based artefacts using reflected light microscopy and micro-X-ray fluorescence. A subset of these artefacts was analysed by electron microprobe spectroscopy for major and minor elements at higher spatial resolution, and by multi-collector inductively coupled plasma mass spectrometry for lead isotopes. Results imply that binary bronze dominated the Roman period, (leaded) brass characterised the Byzantine period, while tin-containing alloys were prevalent during the Islamic period. Lead isotopes suggest that during the Roman and Byzantine periods some of the metal in Jerash came from European and/or Mediterranean sources, while copper used during the Islamic period may have been sourced more locally from Timna. The changes in alloy types and lead isotopes suggest that recycling of metals took place in Jerash possibly as early as the Roman period and more frequent from the Byzantine period onwards
Dust in the Ionized Medium of the Galaxy: GHRS Measurements of Al III and S III
We present interstellar absorption line measurements of the ions S III and Al
III towards six stars using archival Goddard High Resolution Spectrograph data.
The ions Al III and S III trace heavily depleted and non-depleted elements,
respectively, in ionized gas. We use the photoionization code CLOUDY to derive
the ionization correction relating N(Al III)/N(S III) to the gas-phase
abundance [Al/S]_i in the ionized gas. For spectral types considered here, the
corrections are small and independent of the assumed ionization parameter.
Using the results of these photoionization models, we find [Al/S]_i = -1.0 in
the ionized gas towards three disk stars. These values of [Al/S]_i (=[Al/H]_i)
imply that Al-bearing grains are present in the ionized nebulae around these
stars. If the WIM of the Galaxy is photoionized by OB stars, our data for two
halo stars imply [Al/S]_i = -0.4 to -0.5 in the WIM and thus the presence of
dust grains containing Al in this important phase of the ISM. While
photoionization appears to be the most likely origin of the ionization for Al
III and S III, we cannot rule out confusion from the presence of hot,
collisionally ionized gas along two sightlines. We find that [Al/S]_i in the
ionized gas along the six sightlines is anti-correlated with the electron
density and average sightline neutral density. The degree of grain destruction
in the ionized medium of the Galaxy is not much higher than in the warm neutral
medium. The existence of grains in the ionized regions studied here has
important implications for the thermal balance of these regions. (Abstract
Abridged)Comment: 30 pages including 8 embedded tables and 8 embedded figures. Accepted
for publication in the Astrophysical Journa
Testicular Sperm Sampling by Subcapsular Orchiectomy in Klinefelter Patients: A New Simplified Treatment Approach
ObjectiveTo evaluate subcapsular orchiectomy as a method to retrieve spermatozoa from minute testicular foci in men with Klinefelter syndrome (KS).MethodsFourteen men with KS were consecutively recruited to unilateral subcapsular orchiectomy. Testicular tissue was dissected mechanically and enzymatically to identify possible sperm. Previous testosterone replacement therapy was interrupted for 10 months (range: 9-12 months) to minimize a possible effect on the spermatogenesis. Two men with high estrogen/testosterone ratios were treated with aromatase inhibitor (letrozol, 2.5 mg/d for 3 months) before operation.ResultsTesticular sperm were detected in 5 of 14 KS men giving an overall success rate of 36%. The success rate was 50% (5 of 10 men) after exclusion of the 4 men previous treated with androgen substitution. So far, 3 (21%) clinical pregnancies and 2 live births or ongoing pregnancies (14%) have been obtained. Testicular sperm could not be detected in the 2 men treated with aromatase inhibitor before operation. The maximum operative time was 20 minutes, and none had surgical complications such as pain, fever, or hematomas. The mean testosterone level, measured 1-4 months after orchiectomy, decreased to 72% (7.9 ± 2.4 nmol/L) of the preoperative level.ConclusionSubcapsular orchiectomy appears to be easy and quick compared with conventional microtesticular sperm extraction. However, in this pilot study, it has not been possible to demonstrate pregnancy and live birth rates as high as that reported with microtesticular sperm extraction, and further studies are needed before the procedure should be used routinely for sperm retrieval in patients with KS
Hyperglycaemia normalises insulin action on glucose metabolism but not the impaired activation of AKT and glycogen synthase in the skeletal muscle of patients with type 2 diabetes
Current and emerging techniques for contaminant mapping and data visualization at DNAPL sites
What is the Total Deuterium Abundance in the Local Galactic Disk?
Analyses of spectra obtained with the Far Ultraviolet Spectroscopic Explorer
(FUSE) satellite, together with spectra from the Copernicus and IMAPS
instruments, reveal an unexplained very wide range in the observed
deuterium/hydrogen (D/H) ratios for interstellar gas in the Galactic disk
beyond the Local Bubble. We argue that spatial variations in the depletion of
deuterium onto dust grains can explain these local variations in the observed
gas-phase D/H ratios. We present a variable deuterium depletion model that
naturally explains the constant measured values of D/H inside the Local Bubble,
the wide range of gas-phase D/H ratios observed in the intermediate regime (log
N(H I} = 19.2-20.7), and the low gas-phase D/H ratios observed at larger
hydrogen column densities. We consider empirical tests of the deuterium
depletion hypothesis: (i) correlations of gas-phase D/H ratios with depletions
of the refractory metals iron and silicon, and (ii) correlation with the
molecular hydrogen rotational temperature. Both of these tests are consistent
with deuterium depletion from the gas phase in cold, not recently shocked,
regions of the ISM, and high gas-phase D/H ratios in gas that has been shocked
or otherwise heated recently. We argue that the most representative value for
the total (gas plus dust) D/H ratio within 1 kpc of the Sun is >=23.1 +/- 2.4
(1 sigma) parts per million (ppm). This ratio constrains Galactic chemical
evolution models to have a very small deuterium astration factor, the ratio of
primordial to total (D/H) ratio in the local region of the Galactic disk, which
we estimate to be f_d <= 1.19 +/-0.16 (1 sigma) or <= 1.12 +/- 0.14 (1 sigma)
depending on the adopted light element nuclear reaction rates.Comment: 19 pages, 9 figure
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