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Stars close to the main sequence, if they rotate rapidly enough, show magnetic activity in the form of spots, active regions, and strong chromospheres. With the exception of the hybrid stars, stars cooler and more luminous than the so-called Linsky-Haisch dividing line, in contrast, are not known to have any of these phenomena. In fact, it is not clear such stars, even though rotating and convective, show any magnetic phenomena at all. We discuss (1) photometry used to search for spots in the hybrid stars, which we have not found, and (2) evidence for chromospheric variation in K supergiants that takes the form of enhanced winds, but which may be analogous to the activity of stars closer to the main sequence.
Studies have criticized the low level of agreement between the various methods of personality disorder (PD) assessment. This is an important issue for research and clinical purposes.
Seven hundred and forty-two participants in the Hopkins Epidemiology of Personality Disorders Study (HEPS) were assessed on two occasions using the Personality Disorder Schedule (PDS) and the International Personality Disorder Examination (IPDE). The concordance between the two diagnostic methods for all DSM-IV PDs was assessed using standard methods and also two item response analytic approaches designed to take account of measurement error: a latent trait-based approach and a generalized estimating equations (GEE)-based approach, with post-hoc adjustment.
Raw criteria counts, using the intraclass correlation coefficient (ICC), κ and odds ratio (OR), showed poor concordance. The more refined statistical methods showed a moderate to moderately high level of concordance between the methods for most PDs studied. Overall, the PDS produced lower prevalences of traits but higher precision of measurement than the IPDE. Specific criteria within each PD showed varying endorsement thresholds and precision for ascertaining the disorder.
Concordance in the raw measurement of the individual PD criteria between the two clinical methods is lacking. However, based on two statistical methods that adjust for differential endorsement thresholds and measurement error in the assessments, we deduce that the PD constructs themselves can be measured with a moderate degree of confidence regardless of the clinical approach used. This may suggest that the individual criteria for each PD are, in and of themselves, less specific for diagnosis, but as a group the criteria for each PD usefully identify specific PD constructs.
We report on the further development of an ion source for producing intense, continuous beams of large positive and negative cluster ions comprised of high temperature materials. This device, the Smoke-Ion Source, is the result of combining inert gas condensation methods with techniques for injecting electrons directly into expanding jets. We demonstrate the capability of this ion source to generate strong beams of cluster ions comprised of materials including metals, semiconductors, and metal oxide ceramics.
As the 7th brightest star and the most luminous star in the solar neighborhood, Rigel (β Orionis) is a very intriguing object. This blue supergiant (B8 Iab; V-mag = +0.05–0.18-mag; B–V = -0.03), at a distance (from Hipparcos) of ~240±35 pc has a 〈MV〉 = -6.7 mag. The following physical properties were determined via spectroscopic, photometric, and interferometric studies: L/L⊙ ≈ 66,000 K; Teff ≈ 12,000 K; M/M⊙ ≈ 17±3; R/R⊙ ≈ 70; τ ≈ 3–10 Myr. Interestingly Rigel has similar physical properties with the 12th mag blue supergiant progenitor of SN 1987A: Sanduleak -69° 202a. Thus Rigel (along with its co-asterism Betelgeuse) are likely to be the nearest progenitors of a Type II supernova. Such a nearby explosion would be V ≈ -11th mag (similar to a quarter moon).
Global and regional targets to reduce the rate of biodiversity loss bring with them the need to measure the state of nature and how it is changing. A number of different biodiversity indicators have been developed in response and here we consider bird population indicators in Europe. Birds are often used as surrogates for other elements of biodiversity because they are so well known and well studied, and not for their unique intrinsic value as environmental indicators. Yet, in certain situations and at particular scales, trends in bird populations correlate with those of other taxa making them a valuable biodiversity indicator with appropriate caveats. In this paper, we look at two case studies, in the UK and Europe as a whole, where headline bird indicators, that is, summary statistics based on bird population trends, have been developed and used to inform and assist policy makers. Wild bird indicators have been adopted by many European countries and by the European Union as indicators of biodiversity and of sustainable development. In the discussion, we review the strengths and weaknesses of using bird populations in this way, and look forward to how this work might be developed and expanded.
The primary objective of this work is to determine the detailed characteristics of
the flow features induced in a boundary layer by suction through laminar flow control
(LFC) perforations. An additional goal is to validate a predictive method for
generic LFC suction surfaces and to apply this technique to typical flight condition
configurations. Fundamental insights into the flow physics of LFC suction surfaces
are obtained from a unique series of high-resolution three-component laser Doppler
velocimetry (LDV) flow field measurements. The flow fields induced by isolated
super-scale perforations under low-speed conditions are mapped and found to be
strongly three-dimensional and profoundly different from the idealized concept of
continuously distributed suction. Over a range of sub- and super-critical suction flow
rates a variety of suction-dependent complex flow features are identified, including a
pair of contra-rotating streamwise vortices, multiple co-rotating streamwise vortices,
spanwise variations of the mean flow and inherently unstable boundary layer profiles.
The measurements reveal that suction-induced transition commences with an
instability of these attached vortices, resulting in the development of a pair of turbulent
wedges downstream of the perforation. A finite-volume Navier–Stokes method
is validated by simulating a variety of low-speed experiments and comparisons are
made between the LDV measurements and the predicted flow field. The computational technique
reproduces all of the observed flow features, although it slightly
under-predicts their magnitude and extent. By analysing the predicted flow fields the
mechanism for the formation of the trailing vortex pair is established. Earlier flow
visualization experiments, which exhibited vortex shedding, are also simulated by
solving the time-dependent governing equations and it is found that the principal unsteady
flow features are captured. Despite the challenge posed to the computational
method by the diverse range of flow phenomena induced by discrete suction, the
predictions provide good agreement with the measurements and observations. The
computational tool is subsequently applied to predict the flow fields of single and
multiple rows of actual-scale micro-perforations under low-speed and typical transonic
flight conditions. A range of suction-induced flow features are predicted and a
variety of distinct flow modes are identified. The low-speed critical suction limits are
also measured and a design criterion, based on the sucked streamtube characteristics,
is established. The basis of this critical suction criterion is also validated for transonic
Associations between affective disorders, anxiety disorders, and substance use disorders were examined in epidemiological studies conducted in Germany, Switzerland, Puerto Rico, and the mainland US. There was a remarkable degree of similarity across studies in the magnitude and type of specific disorders associated with the affective disorders. Comorbidity with affective disorders was greater for the anxiety disorders than for substance misuse. Panic disorder was the subtype of anxiety that was most highly comorbid with depression. Social phobia was the specific phobic type with the strongest association with the affective disorders. The magnitude of associations between substance misuse and affective disorders generally was quite low and less consistent across sites. No major differences were found in the patterns of comorbidity by gender or age group, affective subtype or prevalence period. The onset of anxiety disorders generally preceded that of depression, whereas alcohol misuse was equally likely to pre- or post-date the onset of affective disorders. Finally, comorbidity was associated with an elevation in treatment ratesacross all sites, confirming Berkson's paradox on an international level.
Ground granulated blast-furnace slag was reacted in 5 M (pH 14.7) and 1.5 M (pH 14.2) NaOH solutions at a water/slag ratio of ∼0.4, and characterized by unconfined compressive strength testing, scanning electron microscopy, energy dispersive spectroscopy, and x-ray diffraction. The reacted material consisted of a dense layered matrix interspersed with unreacted glass particles and regions of reaction products with higher porosity. CSH(I) and (C, M)4AH13 were identified by x-ray diffraction. The C-S-H (calcium silicate hydrate) phase is proposed to consist mainly of structurally imperfect layers of tobermorite, interleaved with layers of (C, M)4AH13. Other cations, most significantly Na+, are incorporated into the structure. Use of the highly concentrated solution (5 M) produced a higher degree of reaction and, consequently, higher compressive strength (38 MPa after 28 days for 5 M solution vs 21 MPa for 1.5 M).
Weed competition in soybeans [Glycine max (L.) Merr. ‘Clark 63′] with planted stands of velvetleaf (Abutilon theophrasti Medic.), prickly sida (Sida spinosa L.), and Venice mallow (Hibiscus trionum L.) is reported. Weeds were planted 0, 10, 20, 30, and 40 days after soybeans and competed until soybeans matured. Soybean seed yields were reduced 720, 250, and 230 kg/ha by velvetleaf, Venice mallow, and prickly sida, respectively. Weeds that emerged with soybeans reduced yields 1,010 kg/ha. Weeds planted 10 days later reduced yields 480 kg/ha, but weeds planted 20 to 40 days after soybeans did not significantly reduced yield. Soybean yields were reduced regardless of weed placement in or between soybean rows. Weed competition reduced numbers of soybean pods per plant more than other soybean-yield components.
Competition studies were conducted with soybeans Glycine max. (L.) Merr. ‘Clark 63’ and Venice mallow (Hibiscus trionum L.). One Venice mallow per 7.5 cm of soybean row reduced soybean seed yield 632 kg/ha after 85 days competition. Thirty to 40-cm weed bands in and between soybean rows reduced yields 270 to 651 kg/ha with 35 to 40 days of competition. A natural stand of 215 Venice mallow plants per square meter reduced soybean yield 454 kg/ha after 30 days of competition, and competition up to 110 days reduced yield as much as 1490 kg/ha. Weed competition affected the number of pods per soybean plant more than any other seed-yield component, and soybean height was reduced. Soybean yields were reduced more when soil moisture was abundant early in the growing season and limited in late summer than when moisture was limited early in the growing season and above average until soybeans matured.
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