ABSTRACT We report the discovery and analysis of a very strong magnetic field in the rapidly rotating early B-type star HR5907, based on observations obtained as part of the Magnetism in Massive ...Stars (MiMeS) project. We infer a rotation period of 0.508276+0.000015-0.000012d from photometric and Hα EW measurements, making this the shortest period, non-degenerate, magnetic massive star known to date. From the comparison of IUE UV and optical spectroscopy with LTE bruce/kylie models we find a solid-angle integrated, uniform black-body temperature of 17000 ± 1000K, a projected rotational velocity of 290 ± 10kms-1, an equatorial radius of 3.1 ± 0.2R, a stellar mass of 5.5 ± 0.5M, and an inclination angle of the rotation axis to our line-of-sight of 70 ± 10°. Our measurements of the longitudinal magnetic field, which vary between -500 and -2000G, phase coherently with the rotation period and imply a surface dipole field strength of 15.7kG. On the other hand, from fits to mean Least-Squares Deconvolved Stokes V line profiles we infer a dipole field strength of 10.4kG. This disagreement may result from a magnetic configuration more complex than our model, and/or from the non-uniform helium surface abundance distribution. In either case we obtain a magnetic obliquity nearly aligned with the rotation axis (). Our optical spectroscopy also shows weak variability in carbon, silicon and nitrogen lines. The emission variability in hydrogen Balmer and Paschen lines indicates the presence of a dense, highly structured magnetosphere, interpreted as a centrifugally supported, magnetically confined circumstellar disc. PUBLICATION ABSTRACT
Abstract Background The renin-angiotensin system (RAS) is activated in heart failure (HF) and inhibition of RAS is a mainstay therapy for HF. Angiotensin-converting enzyme 2 (ACE2) and its product, ...angiotensin 1–7 (Ang-1–7), are important negative regulators of the RAS. Objectives A comprehensive examination of angiotensin peptide levels and therapeutic effects of recombinant human ACE2 (rhACE2) on peptide metabolism was evaluated in human plasma and explanted heart tissue from patients with HF. Methods Using prospective cohorts with chronic (n = 59) and acute (n = 42) HF, plasma angiotensin analysis was performed using a unique liquid chromatography-mass spectrometry/mass spectroscopy method quantifying circulating and equilibrium levels. Angiotensin II (Ang II) metabolism was examined in human explanted hearts with dilated cardiomyopathy (n = 25). Results The dynamic range of the RAS was large, with equilibrium angiotensin levels being 8- to 10-fold higher compared with circulating angiotensin levels. In chronic HF patients receiving ACE inhibition, plasma Ang II was suppressed and plasma Ang-(1–7) was elevated, whereas acute HF and patients receiving angiotensin receptor blocker had higher plasma Ang II with lower Ang-(1–7) levels. Suppressed Ang-(1–7)/Ang II ratio was associated with worsening HF symptoms and longer hospitalization. Recombinant human ACE2 effectively metabolized Ang-(1–10) and Ang II into Ang-(1–9) and Ang-(1–7), respectively. Myocardial Ang II levels in explanted human hearts with dilated cardiomyopathy were elevated despite ACE inhibition with elevated chymase activity, and Ang II was effectively converted to Ang-(1–7) by rhACE2. Conclusions Plasma angiotensin peptides represent a dynamic network that is altered in HF and in response to rhACE2. An increased plasma Ang-(1–7) level is linked to ACE inhibitor use, whereas acute HF reduced Ang-(1–7) levels and suppressed the Ang-(1–7)/Ang II ratio. Increased chymase activity elevated Ang II levels in failing human hearts. Use of rhACE2 effectively normalized elevated Ang II while increasing Ang-(1–7) and Ang-(1–9) levels.
Samples of deep groundwater, river water and rainwater were collected for δ
18O and δ
2H analyses from an area of ∼22,000
km
2 in the arsenic-affected districts of West Bengal, India, in order to ...examine groundwater recharge. A plot of δ
18O versus δ
2H of groundwater falls subparallel to the constructed local meteoric water line (δ
2H
=
7.2 δ
18O
+
7.7), suggesting a predominance of meteoric recharge with some evaporation. The stable isotopic signature of groundwater from the deeper part of the semiconfined main aquifer is similar to that of shallower groundwater, which suggests that deeper groundwater has been recharged in the present-day climatic regime, mostly from monsoonal rainfall. Groundwater in deeper isolated aquifers falls within the isotopic range observed for the main aquifer. A trend of isotopic depletion of groundwater that extends northward and westward from the Bay of Bengal (the monsoonal moisture source area) indicates a rain-out process following Rayleigh-type distillation. Some recharge may have taken place from the rivers Ganges and Bhagirathi-Hoogly, with minimal inflow from other rivers (Jalangi and Ichamati).
The geochemistry of deposition of the Meade Peak Member of the Phosphoria Formation (MPM) in southeast Idaho, USA, a world-class sedimentary phosphate deposit of Permian age that extends over 300,000
...km
2, is ascertained from its rare earth element (REE) composition. Ratios of REE:Al
2O
3 suggest two sources—seawater and terrigenous debris. The seawater-derived marine fraction identifies bottom water in the Phosphoria Sea as O
2-depleted, denitrifying (suboxic) most of the time, and seldom sulfate-reducing (anoxic). This interpretation is supported by earlier research that showed progressively greater ratios in the marine sediment fraction of Cr:Ni>V:Ni⪢Mo:Ni, relative to their ratios in seawater; for which marine Cr, V, and Mo can have a dominantly O
2–depleted bottom-water source and Ni a photic-zone, largely algal, source. The water chemistry was maintained by a balance between bacterial oxidation of organic matter settling through the water column, determined largely by primary productivity in the photic zone, and the flux of oxidants into the bottom water via advection of seawater from the open ocean.
Samples strongly enriched in carbonate fluorapatite, the dominant REE host mineral, have variable Er/Sm, Tm/Sm, and Yb/Sm ratios. Their distribution may represent greater advection of seawater between the Phosphoria Sea and open ocean during deposition of two ore zones than a center waste and greater upwelling of nutrient-enriched water into the photic zone. However, the mean rate of deposition of marine Ni, a trace nutrient of algae, and PO
4
3−, a limiting nutrient, indicate that primary productivity was probably high throughout the depositional history. An alternative interpretation of the variable enrichments of Er, Tm, and Yb, relative to Sm, is that they may reflect temporally variable carbonate alkalinity of open-ocean seawater in Permian time.
A more strongly negative Ce anomaly for all phosphatic units than the Ce anomaly of modern pelletal phosphate is further indicative of an elevated O
2 concentration in the Permo-Carboniferous open ocean, as proposed by others, in contrast to the depletion of O
2 in the bottom water of the Phosphoria Sea itself.
The oceanographic conditions under which the deposit accumulated were likely similar to conditions under which many sedimentary phosphate deposits have accumulated and to conditions under which many black shales that are commonly phosphate poor have accumulated. A shortcoming of several earlier studies of these deposits has resulted from a failure to examine the marine fraction of elements separate from the terrigenous fraction.
ABSTRACT
Fine‐grained Palaeogene–early Neogene strata of the South Caspian basin, specifically the Oligocene–Lower Miocene Maikop Series, are responsible for the bulk of hydrocarbon generation in the ...region. Despite the magnitude of oil and gas currently attributed to the source interval offshore, geochemical evaluation of 376 outcrop samples from the northern edge of the Kura basin (onshore eastern Azerbaijan) indicates that depositional conditions in these proximal strata along the basin margins were dominantly oxic to mildly suboxic/anoxic throughout three major depositional stages: the Palaeocene–Eocene, Oligocene–early Middle Miocene and late Middle–Late Miocene. Palaeocene–Eocene samples have low average total organic carbon (TOC) values (0.3%), with higher total inorganic carbon (TIC) values (average=2.6%), extremely low sulphur content (0.2%) and relatively high detrital input as indicated by Fe/Al and Ti/Al ratios. C–S–Fe associations, along with relatively lower concentrations of redox‐sensitive trace elements (e.g. V, Ni, Mo, U) indicate dominantly oxic environments of deposition during much of the Palaeocene–Eocene. A pronounced geochemical shift occurred near the Eocene–Oligocene boundary, and continued through the Early Miocene. Specifically, this interval is characterized by a distinct increase in TOC (ranging from 0.1 to 6.3% with an average of 1.5%), C–S–Fe associations that reveal an abrupt relative increase of carbon and sulphur with respect to iron‐dominated Palaeocene–Eocene samples, and higher concentrations of redox‐sensitive trace metals. These changes suggest that a shift away from unrestricted marine conditions and towards more variable salinity conditions occurred coincident with the initial collision of the Arabian plate and partial closure of the Paratethys ocean. Despite periodic basin restriction, the majority of Upper Eocene–Lower Miocene strata in the northern Kura basin record oxic to slightly dysoxic conditions.
We examined the Trail Making Test (TMT) in a sample of 767 participants with prodromal Huntington disease (prodromal HD) and 217 healthy comparisons to determine the contributions of motor, ...psychiatric, and cognitive changes to TMT scores. Eight traditional and derived TMT scores were also evaluated for their ability to differentiate prodromal participants closer to estimated age of diagnosis from those farther away and prodromal individuals from healthy comparisons. Results indicate that motor signs only mildly affected Part A, and psychiatric symptoms did not affect either part. Tests of perceptual processing, visual scanning, and attention were primarily associated with Part A, and executive functioning (response inhibition, set-shifting), processing speed, and working memory were associated with Part B. Additionally, TMT scores differentiated between healthy comparisons and prodromal HD individuals as far as 9-15 years before estimated diagnosis. In participants manifesting prodromal motor signs and psychiatric symptoms, the TMT primarily measures cognition and is able to discriminate between groups based on health status and estimated time to diagnosis.
Among the population of the Foodborne Diseases Active Surveillance Network (FoodNet) surveillance areas ("FoodNet sites") in 1996, children under 12 months of age had the highest incidence of ...sporadic salmonellosis. We conducted a case-control study in 5 FoodNet sites to identify risk factors for sporadic infant salmonellosis. A case patient was a child under 12 months of age with a laboratory-confirmed, nontyphoidal serogroup B or D Salmonella infection. Twenty-two case patients were matched with 39 control subjects by age and either telephone exchange or vital record birth list. In a multivariate analysis, case patients were more likely to have a liquid diet containing no breast milk than a liquid diet containing only breast milk (matched odds ratio, 44.5; P = .04). Case-patients were more likely to reside in a household where a member had diarrhea (matched odds ratio, 13.2; P = .01). To decrease their infants' risk of salmonellosis, mothers should be encouraged to breast-feed their infants. Caretakers of infants should learn about salmonellosis, hand washing, and safe preparation of formula and solid food.
We present results from three weeks' photometric monitoring of the magnetic helium-strong star sigma Ori E using the Microvariability and Oscillations of Stars microsatellite. The star's light curve ...is dominated by twice-per-rotation eclipse-like dimmings arising when magnetospheric clouds transit across and occult the stellar disk. However, no evidence is found for any abrupt centrifugal breakout of plasma from the magnetosphere, either in the residual flux or in the depths of the light minima. Motivated by this finding we compare the observationally inferred magnetospheric mass against that predicted by a breakout analysis. The large discrepancy between the values leads us to argue that centrifugal breakout does not play a significant role in establishing the magnetospheric mass budget of sigma Ori E.
Chemostratigraphic evidence from the Barnett Formation (Texas, USA) elucidates the restricted nature of the depositional environment in the Fort Worth Basin during the early progression of the late ...Paleozoic Ouachita Orogeny. In accord with recent lithostratigraphic and petrographic studies, stratigraphic bulk geochemical analyses reveal that the environment of deposition was anoxic to euxinic, sediment-starved, with relatively high rates of organic matter accumulation. Using an environmental proxy developed from the sediment geochemistry of modern anoxic silled basins, the stratigraphic concentrations of total organic carbon (TOC) and molybdenum (Mo) in the Barnett Formation reveal a high degree of subpycnoclinal water mass restriction and an extended timescale of deep-water renewal of at least 8
×
10
3 years and potentially as long as 2
×
10
4 years.
An integrated assessment of elemental concentrations, the degree of pyritization, and TOC–S–Fe relationships reveals that severe Fe limitation controlled pyrite formation and the large excess of sulfide in the overlying water column. Mineralogical and elemental constraints suggest that, following sulfate reduction, less easily bio-extractable Fe(III) was bio-reduced under methanogenic conditions, consequently liberating Fe(II) which was subsequently incorporated into pore-water-formed dolomite (i.e., organogenic dolomite). The preserved Mo–TOC, TOC–S–Fe, and Fe-bearing mineral relationships collectively indicate that the protracted turnover rate and persistent sediment starvation resulted in a biologically inhospitable environment that limited the microbial consumption rate of organic carbon.
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