We analyse near-infrared Hubble Space Telescope (HST)/Near-Infrared Camera and Multi-Object Spectrometer F110W (J) and F160W (H) band photometry of a sample of 27 i′-drop candidate z≃ 6 galaxies in ...the central region of the HST/Advanced Camera for Surveys Ultra Deep Field. The infrared colours of the 20 objects not affected by near neighbours are consistent with a high-redshift interpretation. This suggests that the low-redshift contamination of this i′-drop sample is smaller than that observed at brighter magnitudes, where values of 10–40 per cent have been reported. The J–H colours are consistent with a slope flat in fν(fλ∝λ−2), as would be expected for an unreddened starburst. However, there is evidence for a marginally bluer spectral slope (fλ∝λ−2.2), which is perhaps indicative of an extremely young starburst (∼10 Myr old) or a top heavy initial mass function and little dust. The low levels of contamination, median photometric redshift of z∼ 6.0 and blue spectral slope, inferred using the near-infrared data, support the validity of the assumptions in our earlier work in estimating the star formation rates, and that the majority of the i-drop candidates galaxies lie at z∼ 6.
Background: Hypertension is an important risk factor for cardiovascular disease; however, limited findings are available on its detection and management in rural Australia.
Aim: To assess the ...prevalence, awareness and treatment of hypertension in a rural South‐East Australian population.
Methods: Three cross‐sectional surveys in Limestone Coast, Corangamite Shire and Wimmera regions during 2004–2006 using a random population sample (n = 3320, participation rate 49%) aged 25–74 years. Blood pressure was measured by trained nurses. Information on history of hypertension and medication was obtained by questionnaires. Hypertension was defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg and/or on antihypertensive drug treatment.
Results: Overall, one‐third of participants had hypertension; of these, two‐thirds, 54% (95% confidence interval (CI) 47–60) of men and 71% (95% CI 65–77) of women, were aware of their condition. Half of the participants with hypertension were treated and nearly half of these were controlled. Both treatment and control were more common in women (60%, 95% CI 54–67 and 55%, 95% CI 47–64) compared with men (42%, 95% CI 36–49 and 35%, 95% CI 26–44). Monotherapy was used by 55% (95% CI 48–61) of treated hypertensives. Angiotensin‐converting enzyme inhibitors were the most frequently used class of antihypertensive drugs in men, whereas angiotensin‐converting enzyme inhibitors, angiotensin receptor antagonists and diuretics were all widely used among women.
Conclusion: This study emphasizes suboptimal detection and treatment of hypertension, especially in men, in rural Australia.
Osteoporotic fractures are less prevalent in African Americans than in caucasians, possibly because of differences in bone structural strength. Bone structural adaptation can be attributed to changes ...in load, crudely measured as lean and fat mass throughout life. The purpose of this analysis was to describe the associations of leg lean mass, total body fat mass, and hours walked per week with femoral bone mineral density (BMD) and bone geometry in a cross-sectional sample of 1,748 men of African descent between the ages of 40 and 79 years. BMD, section modulus (Z), cross-sectional area (CSA), and subperiosteal width were measured from dual energy X-ray absortiometry (DXA) scans using the hip structural analysis (HSA) program. Multiple linear regression models explained 35% to 48% of the variance in bending (Z) and axial (CSA) strength at the femoral neck and shaft. Independent of all covariates including total body fat mass, one standard deviation increase in leg lean mass was significantly associated with a 5% to 8% higher Z, CSA, and BMD (P < 0.010) at the neck and shaft. The number of hours walked per week was not a strong or consistent independent predictor of bone geometry or BMD. We have shown that weight is the strongest independent predictor of femur BMD and geometric strength although the effect appears to be mediated by lean mass since leg lean mass fraction and total body fat mass fraction had significant and opposing effects at the narrow neck and shaft in this group of middle aged and elderly men.
Inappropriate thrombus formation within blood vessels is the leading cause of mortality in the industrialized world. Factor Xa (FXa) is a trypsin-like serine protease that plays a key role in the ...blood coagulation cascade and represents an attractive target for anticoagulant drug development. From a high-throughput in vitro mass screen of our chemical library, we identified 4-5-(2R,6S)-2, 6-dimethyltetrahydro-1(2H)-pyridinylpentyl-2-phenyl-2H-1, 4-benzoxazin-3(4H)-one (1a) as an inhibitor of FXa with an IC(50) of 27 microM. Through a combination of SAR studies and molecular modeling, we synthesized 3-(4-5-(2R,6S)-2, 6-dimethyltetrahydro-1(2H)-pyridinylpentyl-3-oxo-3,4-dihydro-2H- 1,4-benzoxazin-2-yl)-1-benzenecarboximidamide (1n) which was a potent FXa inhibitor with an IC(50) of 3 nM. This compound exhibited high selectivity for FXa over other related serine proteases and was efficacious when dosed intravenously in rabbit and dog antithrombotic models.
The near-infrared spectrograph (NIRSpec) on the James Webb Space Telescope (JWST) offers the first opportunity to use integral-field spectroscopy from space at near-infrared wavelengths. More ...specifically, NIRSpec's integral-field unit can obtain spectra covering the wavelength range 0.6−5.3 µm for a contiguous 3.1 × 3.2 sky area at spectral resolutions of R ≈ 100, 1000, and 2700. In this paper we describe the optical and mechanical design of the NIRSpec integral-field spectroscopy mode, together with its expected performance. We also discuss a few recommended observing strategies, some of which are driven by the fact that NIRSpec is a multipurpose instrument with a number of different observing modes, which are discussed in companion papers. We briefly discuss the data processing steps required to produce wavelength-and flux-calibrated data cubes that contain the spatial and spectral information. Lastly, we mention a few scientific topics that are bound to benefit from this highly innovative capability offered by JWST/NIRSpec.
In this paper, the third and final of a series, we present complete K-band imaging and some complementary I-band imaging of the filtered 6C* sample. We find no systematic differences between the K–z ...relation of 6C* radio galaxies and those from complete samples, so the near-infrared properties of luminous radio galaxies are not obviously biased by the additional 6C* radio selection criteria (steep spectral index and small angular size). The 6C*K–z data significantly improve delineation of the K–z relation for radio galaxies at high redshift (z>2). Accounting for non-stellar contamination, and for correlations between radio luminosity and stellar mass, we find little support for previous claims that the underlying scatter in the stellar luminosity of radio galaxies increases significantly at z>2. In a particular spatially flat universe with a cosmological constant (ΩM = 0.3 and ΩΛ = 0.7), the most luminous radio sources appear to be associated with galaxies with a luminosity distribution with a high mean (≈5 L*), and a low dispersion (σ∼0.5 mag) which formed their stars at epochs corresponding to z≳2.5. This result is in line with recent submillimetre studies of high-redshift radio galaxies and the inferred ages of extremely red objects from faint radio samples.
Driving Patterns and Medical Conditions in Older Women Forrest, Kimberly Y.-Z.; Bunker, Clareann H.; Songer, Thomas J. ...
Journal of the American Geriatrics Society (JAGS),
October 1997, Letnik:
45, Številka:
10
Journal Article
Recenzirano
OBJECTIVES: To describe driving patterns (e.g., driving frequency) in older women drivers and to evaluate the impact of medical conditions and comorbidity on driving patterns.
DESIGN: Cross‐sectional ...examination of the association between medical conditions and driving patterns.
SETTING: Population‐based cohort from the Pittsburgh Center of the Study of Osteoporotic Fractures (SOF).
PARTICIPANTS: A total of 1768 women aged 71 years or older.
MAIN MEASUREMENTS: Driving information was obtained through a driving questionnaire, including driving status, weekly mileage, longest trip in the past year, etc. Data for demographics, lifestyle behavior, and medical conditions were collected through the SOF study.
RESULTS: Among the participants, 1103 (62.3%) were current drivers, 337 (19.1%) had stopped driving, and 329 (18.6%) had never driven in their lifetime. The proportion reporting driving cessation and decline in driving amount increased with age. The prevalence of most medical conditions was higher among former drivers than in current or never drivers. Even after controlling for age and other demographic variables, fractures, heart disease, diabetes, self‐ reported poor vision or hearing, as well as comorbidity were found to be associated independently with decreased driving amount, including driving cessation, decline in mileage, and avoiding long trips.
CONCLUSION: Both individual medical conditions and comorbidity influence driving patterns in older drivers. Because it is common for older people to have several medical conditions simultaneously, comorbidity might be a more comprehensive measure of medical impact on driving.
Spatially resolved spectroscopic data from the CIRPASS integral field unit (IFU) on Gemini are used to measure the gravitational lensing of the four-image quasar Q2237+0305 on different size scales. ...A method for measuring the substructure present in the lens using observations at multiple wavelengths is demonstrated to be very effective and independent of many of the degeneracies inherent in previous methods. The magnification ratios of the QSO's narrow-line region (NLR) and broad-line region (BLR) are measured and found to disagree with each other and with the published radio and mid-infrared magnification ratios. The disagreement between the BLR ratios and the radio/mid-infrared ratios is interpreted as the result of microlensing by stars in the lens galaxy of the BLR. This implies that the mid-infrared emission region is larger than the BLR and that the BLR is ~0.1 pc in size. We find a small difference between the shape of the H beta line in image A and that in the other images. We consider this difference too small and symmetric to be strong evidence for rotation or large- scale infall in the H beta emission region. The disagreement between the radio/mid- infrared ratios and the NLR ratios is interpreted as a signature of substructure on a larger scale, possibly the missing small-scale structure predicted by the standard cold dark matter (CDM) model. Extensive lensing simulations are performed to obtain a lower limit on the amount of substructure that is required to cause this discrepancy as a function of its mass and the radial profile of the host lens. The substructure surface density is degenerate with the radial profile of the host lens, but if the expectations of the CDM model are taken into account, certain radial profiles and substructure surface densities can be ruled out. A substructure mass scale as large as 10 super(8) M sub(o) is strongly disfavored, while 10 super(4) M sub(o) is too small if the radio and mid-infrared emission regions have the expected sizes of approx10 pc. The standard elliptical isothermal lens mass profile is not compatible with a substructure surface density of capital sigma sub(sub) < 280 M sub(o) pc super(-2), at the 95% confidence level. This is 4%-7% of the galaxy's surface density (depending on which image position is used to evaluate this). The required substructure surface density at the required mass scale is high in comparison with the present expectations within the CDM model. Lens mass profiles that are flatter than isothermal-where the surface density in dark matter is higher at the image positions-are compatible with smaller quantities of substructure.
We measure the ages, stellar masses, and star formation histories of z∼ 6 galaxies, observed within 1 Gyr of the big bang. We use imaging from the Hubble Space Telescope (HST) and the Spitzer Space ...Telescope from the public ‘Great Observatories Origins Deep Survey’ (GOODS), coupled with ground-based near-infrared imaging, to measure their spectral energy distributions (SEDs) from 0.8–5 μm, spanning the rest-frame ultraviolet (UV) and optical. From our sample of ≈50 ‘i′-drop’ Lyman-break star-forming galaxies in GOODS-South with z′AB < 27, we focus on ≈30 with reliable photometric or spectroscopic redshifts. Half of these are confused with foreground sources at Spitzer resolution, but from the 16 with clean photometry we find that a surprisingly large fraction (40 per cent) have evidence for substantial Balmer/4000-Å spectral breaks. This indicates the presence of old underlying stellar populations that dominate the stellar masses. For these objects, we find ages of ∼200–700 Myr, implying formation redshifts of 7 ≤zf≤ 18, and large stellar masses in the range ∼1–3 × 1010 M⊙. Analysis of seven i′-drops that are undetected at 3.6 μm indicates that these are younger, considerably less massive systems. We calculate that emission line contamination should not severely affect our photometry or derived results. Using SED fits out to 8 μm, we find little evidence for substantial intrinsic dust reddening in our sources. We use our individual galaxy results to obtain an estimate of the global stellar mass density at z∼ 6. Correcting for incompleteness in our sample, we find the z∼ 6 comoving stellar mass density to be 2.5 × 106 M⊙ Mpc−3. This is a lower limit, as post-starburst and dust-obscured objects, and also galaxies below our selection thresholds, are not accounted for. From our results, we are able to explore the star formation histories of our selected galaxies, and we suggest that the past global star formation rate may have been much higher than that observed at the z∼ 6 epoch. The associated UV flux we infer at z > 7 could have played a major role in reionizing the Universe.
We present the results of optical spectroscopy of two flux-density-limited samples of radio sources selected at frequencies of 38 and 151 MHz in the same region around the North Ecliptic Cap, the ...8C-NEC and 7C-iii samples respectively. Both samples are selected at flux density levels ≈20 times fainter than samples based on the 3C catalogue. They are amongst the first low-frequency selected samples with no spectral or angular size selection for which almost complete redshift information has been obtained, and contain many of the lowest-luminosity z>2 radio galaxies so far discovered. They will therefore provide a valuable resource for understanding the cosmic evolution of radio sources and their hosts and environments. The 151-MHz 7C-iii sample is selected to have S151=0.5 Jy and is the more spectroscopically complete; out of 54 radio sources fairly reliable redshifts have been obtained for 44 objects. The 8C sample has a flux limit of S38=1.3 Jy and contains 58 sources of which 46 have fairly reliable redshifts. We discuss possible biases in the observed redshift distribution, and some interesting individual objects, including a number of cases of probable gravitational lensing. Using the 8C-NEC and 7C-iii samples in conjunction, we form the first sample selected on low-frequency flux in the rest-frame of the source, rather than the usual selection on flux density in the observed frame. This allows us to remove the bias associated with an increasing rest-frame selection frequency with redshift. We investigate the difference this selection makes to correlations of radio source properties with redshift and luminosity by comparing the results from traditional flux-density selection with our new method. We show in particular that flux-density-based selection leads to an overestimate of the steepness of the correlation of radio source size with redshift.
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