To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Quasars with similar core-compact radio properties can be classified by their differences at optical and infrared frequencies. Their X-ray properties might be expected to be similar if the synchrotron self-Compton mechanism relates their radio and X-ray emission. We have compared the 0.2–3.5 keV mean power-law energy spectral indices, , for 4 quasar classes: 12 Highly Polarized QSOs (HPQs), 19 Flat Radio Spectrum, core-compact, low-polarization, QSOs (FRS QSOs), 24 radio-selected BL Lac objects, and 7 X-ray-selected BL Lac objects.
We present fits of models for the C IV λ 1549, N V λ1240 and Lα lines to observed profile data. Since these lines depend sensitively on the cloud ionization parameter (defined as the ratio of the illuminating flux to the cloud pressure; c.f. Krolik, McKee, and Tarter, 1981) and pressure, their relative strengths constrain the distribution of clouds in quasar broad line regions. We make the following assumptions: That the distribution of clouds around the continuum source is spherical and that the cloud motion relative to the continuum source is radial; that the clouds are in pressure equilibrium with hot intercloud medium (ICM) whose mass flux is conserved; and that the line fluxes emitted by the clouds as a consequence of the continuum illumination is given by “standard” (e.g. Kwan and Krolik, 1981) photoionization models. The cloud mass flux is not assumed to be constant, but is allowed to vary with velocity in order to fit the data. For the purposes of illustration, we have chosen a specific dynamical model: isothermal freefall with TICM = 108K. The cloud column density is assumed to be fixed at 1023cm−2.
We present high resolution (HPBW = 5 arcsec) continuum and molecular-line observations of the circumstellar environment of the emission-line star LkHα 234 made with the Owens Valley Millimeter-Wave Interferometer. These 98 GHz observations have revealed an unresolved continuum source coincident with the star and a 10 000 by 17000 A.U. ridge of enhanced CS(2-1) emission which peaks ∼ 4″ east of the star. The resulting spectral dependence for the radio continuum emission of ν1.5 is most easily interpreted as arising from a partially ionized stellar wind. Attempts are made to describe the properties of the CS emission in terms of a rotating molecular disk which would link LkHα 234 with large scale mass loss activity in the cloud. However, it appears most likely that the CS emission is arising from a dense (n(H2) ∼ 106 cm −3) condensation of gas adjacent to, but not dynamically associated with, the star.
A review of the importance of water maser observations toward young stellar objects (YSOs) is presented. Also, we present recent, differing types of observations of water masers near YSOs. Single antenna observations, taken regularly, characterize the variability of the masers and allow estimates of time and spatial scales. High resolution (∼ 1 mas) multi-epoch observations allow proper motions to be studied. Detailed analysis of such proper motions will allow the placement of the masers in the circumstellar (a disk) or near-stellar environment at the base of the outflow. Radio interferometric techniques are the best method of making estimates of the kinematics of the gas in these regions.
With the advent of new correlators and dedicated arrays, spectral line VLBI is entering its ascendancy as a probe of a variety of interesting astrophysical environments. One of the most interesting environments where spectroscopic VLBI techniques are valuable are the regions directly coincident with forming stars. In these sources, water maser emission is observed when the outflowing jets of material interact with the surrounding medium. Observations of these water masers dramatically reveal the innermost regions of the star formation process at or below the 1-AU scale.
We have found that the water masers clearly trace the jets at these scales. The masers show space motions on the order of 60 to 100 kms−1 and form within a few AU of the exciting protostar. By observing the distributions and motions of the water masers associated with these objects, we may be able to address in greater detail the collimation mechanism of the jets seen in these protostars.
In this brief poster proceeding, we provide a summary image of the water masers associated with SVS13, the driving source for the HH 7-11 objects. We have also mapped the masers associated with IRAS 16293-2422, IRAS 05413-0104, IRAS 4A and IRAS 4B, both in the NGC 1333 star forming region. For further information on these sources, please contact any of the authors directly.
A recent outbreak of Q fever was linked to an intensive goat and sheep dairy farm in Victoria, Australia, 2012-2014. Seventeen employees and one family member were confirmed with Q fever over a 28-month period, including two culture-positive cases. The outbreak investigation and management involved a One Health approach with representation from human, animal, environmental and public health. Seroprevalence in non-pregnant milking goats was 15% [95% confidence interval (CI) 7–27]; active infection was confirmed by positive quantitative PCR on several animal specimens. Genotyping of Coxiella burnetii DNA obtained from goat and human specimens was identical by two typing methods. A number of farming practices probably contributed to the outbreak, with similar precipitating factors to the Netherlands outbreak, 2007-2012. Compared to workers in a high-efficiency particulate arrestance (HEPA) filtered factory, administrative staff in an unfiltered adjoining office and those regularly handling goats and kids had 5·49 (95% CI 1·29–23·4) and 5·65 (95% CI 1·09–29·3) times the risk of infection, respectively; suggesting factory workers were protected from windborne spread of organisms. Reduction in the incidence of human cases was achieved through an intensive human vaccination programme plus environmental and biosecurity interventions. Subsequent non-occupational acquisition of Q fever in the spouse of an employee, indicates that infection remains endemic in the goat herd, and remains a challenge to manage without source control.
Accumulating evidence links childhood adversity to negative health outcomes in adulthood. However, most of the available evidence is retrospective and subject to recall bias. Published reports have sometimes focused on specific childhood exposures (e.g. abuse) and/or specific outcomes (e.g. major depression). Other studies have linked childhood adversity to a large and diverse number of adult risk factors and health outcomes such as cardiovascular disease. To advance this literature, we undertook a broad examination of data from two linked surveys. The goal was to avoid retrospective distortion and to provide a descriptive overview of patterns of association.
A baseline interview for the Canadian National Longitudinal Study of Children and Youth collected information about childhood adversities affecting children aged 0–11 in 1994. The sampling procedures employed in a subsequent study called the National Population Health Survey (NPHS) made it possible to link n = 1977 of these respondents to follow-up data collected later when respondents were between the ages of 14 and 27. Outcomes included major depressive episodes (MDE), some risk factors and educational attainment. Cross-tabulations were used to examine these associations and adjusted estimates were made using the regression models. As the NPHS was a longitudinal study with multiple interviews, for most analyses generalized estimating equations (GEE) were used. As there were multiple exposures and outcomes, a statistical procedure to control the false discovery rate (Benjamini–Hochberg) was employed.
Childhood adversities were consistently associated with a cluster of potentially related outcomes: MDE, psychotropic medication use and smoking. These outcomes may be related to one another since psychotropic medications are used in the treatment of major depression, and smoking is strongly associated with major depression. However, no consistent associations were observed for other outcomes examined: physical inactivity, excessive alcohol consumption, binge drinking or educational attainment.
The conditions found to be the most strongly associated with childhood adversities were a cluster of outcomes that potentially share pathophysiological connections. Although prior literature has suggested that a very large number of adult outcomes, including physical inactivity and alcohol-related outcomes follow childhood adversity, this analysis suggests a degree of specificity with outcomes potentially related to depression. Some of the other reported adverse outcomes (e.g. those related to alcohol use, physical inactivity or more distal outcomes such as obesity and cardiovascular disease) may emerge later in life and in some cases may be secondary to depression, psychotropic medication use and smoking.
ZnO nanowire (NW) arrays were examined with Transmission Electron Microscopy (TEM) in cross-section after preparation by Focused Ion Beam (FIB) milling. This technique revealed that ZnO nanowires grown using a Au catalyzed vapor technique typically have Au particles at the NW tips, and also randomly dispersed across the base crystal growth that joins adjacent NWs. It is shown the adjacent NWs and the combined base growth is one crystal structure which can be used as a back electrical contact making fabrication of vertical array devices possible. However, the base growth displays detrimental features such as embedded Au particles and lattice defects which can affect the electrical output through depletion regions and scattering centers. In an effort to overcome these problems we investigate a growth method that is nucleated through a minor alteration of the a-plane sapphire surface roughness via a weak chemical etch. Observations of various stages of the growth show the growth nucleates as separate nanoislands that grow in c-plane alignment with Sapphire (1-210), and as growth continues these islands meet and form a polycrystalline film. Further growth initiates nanowire growth and the formation of a single crystal base layer and NW structure that can cover several square millimeter’s. This allows high quality arrays that are relatively free from defects to be formed without any metals contamination and ready for further device processing.
Considerable evidence now links childhood adversity to a variety of adult health problems. Unfortunately, almost all of these studies have relied upon retrospective assessment of childhood events, creating a vulnerability to bias. In this study, we sought to examine three associations using data sources that allowed for both prospective and retrospective assessment of childhood events.
Methods. A 1994 national survey of children between the ages of 0 and 11 collected data from a ‘person most knowledgeable’ (usually the mother) about a child. It was possible to link data for n = 1977 of these respondents to data collected from the same people in a subsequent adult study. The latter survey included retrospective reports of childhood adversity. We examined three adult health outcomes in relation to prospectively and retrospectively assessed childhood adversity: major depressive episodes, excessive alcohol consumption and painful conditions.
Results. A strong association between childhood adversities (as assessed by both retrospective and prospective methods) and major depression was identified although the association with retrospective assessment was stronger. Weaker associations were found for painful conditions, but these did not depend on the method of assessment. Associations were not found for excessive alcohol consumption irrespective of the method of assessment.
These findings help to allay concerns that associations between childhood adversities and health outcomes during adulthood are merely artefacts of recall bias. In this study, retrospective and prospective assessment strategies produced similar results.
What does it mean to think “I,” to say “I,” to write “I”? These foundational questions of subjectivity inform Annette von Droste-Hulshoff's literary production to such an extent that one might arguably define her oeuvre in terms of the early German Romantic notion of autopoiesis, the self-reflexive, self-critical self-creation of the subject, das Ich (the I), in and through poesy. Yet in contradistinction to the unitary structure of early Romantic subjectivity, for Droste the self frequently is presented as an object, an object often watched by—and at times watching—the subject, an object that is irreconcilable with the subject. significantly, many of these scenes of objectified self-definition are explicitly presented as aesthetic events, indicating their programmatic status in Droste's poetics, and they recur emblematically throughout her writing.
The following analysis seeks to elucidate Droste's object-driven conception of subjectivity and poetic production through a series of examples. The first section considers the early prose fragment Ledwina (1818/19–26). The second presents brief readings of a selection of her more famous poems and ballads, written between 1840 and 1844: “Das Spiegelbild” (The mirror image), “Im Moose” (In the moss), “Das Fraulein von Rodenschild” (Lady von Rodenschild), “Das erste Gedicht” (The first poem), “Das alte schloss” (The old castle), “Im Grase” (In the grass), “Die todte Lerche” (The dead lark), “Die Taxuswand” (The yew wall), “Die Mergelgrube” (The marl pit) and “Lebt wohl” (Farewell).
Hans Blumenberg's early historical examination of the metaphorology of the shipwreck, Schiffbruch mit Zuschauer (Shipwreck with spectator), lays out the existential import this image held for Western thought from antiquity through to philosophical modernism. For Blumenberg, the metaphor of the ocean voyage assumes a place along-side that of air flight and the Promethean theft of fire as one of the staple concretizations of human arrogance in its attempts to challenge and tame the laws of nature (14–15). The sea voyage in particular encapsulates, according to Blumenberg, a paradigmatic moment of human blasphemy, codified in the attempt to transgress those natural conditions that bind human existence to terra firma, and to venture out into that element that paradigmatically embodies the forces of incalculability, lawlessness, and total lack of orientation: the infinitely vast and wholly unpredictable ocean (10). Blumenberg identifies precisely that liminal space between terra firma and the immeasurable expanse of the ocean as the place that embodies and symbolically invokes this constant human drive toward transgression of its existential limitations. Blumenberg's language points immediately to the relevance this model holds specifically for Faust in part 2 of Goethe's drama: “Daß hier, an der Grenze vom festen Land zum Meer, zwar nicht der Sündenfall, aber doch der Verfehlungsschritt ins Ungemäße und Maßlose zuerst getan wurde, ist von der Anschaulichkeit, die dauerhafte Topoi trägt” (11; The fact that this border between firm land and the sea marks the place where, to be sure, not the fall from grace per se, but the first transgressive step into inexpedience and immoderation was taken, has the vividness that only lasting topoi possess).
Invoking Goethe's name has become fashionable again. With new methods and technologies of reading threatening to render literature virtual and insubstantial, we have the sense that "Goethe's ghosts" - the otherwise neglected voices and traditions that, finding their most trenchant expression in Goethe, inform the Western storehouse of literature - can show us long-forgotten dimensions of literature. Inspired by the distinguished Goethe scholar Jane Brown, whose life's work has called attention to the allegorical modes haunting the mimetic forms that dominate modern literature, the contributors to this volume take a rich variety of approaches to Goethe: cultural studies, history of the book, semiotics, deconstruction, colonial studies, feminism, childhood studies, and eco-criticism. The persistence, omnipresence, and modalities of the "ghosts" they find suggest that more than influence or standards is at issue here. Goethe's work informs current debates on nineteenth-century nationalism, while his Faust increasingly serves to express contemporary culture's anxiety about new technologies. The stubborn reappearance of these revenants testifies to more fundamental issues concerning the status of literature and the task of the reader. As the contributors demonstrate, these questions acquire renewed urgency in writers as diverse as Hegel, Adorno, Benn, Droste-Hülshoff, and Nietzsche. Each of the essays testifies to the enduring salience and presence of Goethe. Contributors: Helmut Ammerlahn, Benjamin Bennett, Richard Block, Dieter Borchmeyer, Franz-Josef Deiters, Richard T. Gray, Martha B. Helfer, Meredith Lee, Clark Muenzer, Andrew Piper, Simon Richter, Jürgen Schroeder, Peter Schwartz, Patricia Simpson, Robert Tobin, David Wellbery, Sabine Wilke. Simon Richter is Professor of German Literature at the University of Pennsylvania. Richard Block is Associate Professor of German at the University of Washington.