9,512 research outputs found
Child support enforcement for teenage fathers: Problems and prospects
The NLSY data indicate that about 7.3 percent of teenage males become fathers and that very few of these fathers live with their children. Father absence and the concurrent increase in female-headed households are closely associated with the impoverishment of children. Most absent teen fathers never come into contact with the child support enforcement program, and the extent to which they financially support their children informally is not well understood. While the income of absent teen fathers is low in the teen years, it increases over time, as does the potential for collecting child support. Nevertheless, men who were absent teen fathers earn less in early adulthood than men who deferred parenting until age twenty or later and teen fathers who lived with their children. Early establishment of paternity and greater standardization in the treatment of adolescent fathers by the child support enforcement program are recommended. Further, the substantial and persistent income deficit experienced by adolescent fathers who live apart from their children raises an interesting dilemma. While children may benefit financially and psychosocially from living with two parents, the lower income of men who were absent teenage fathers may make them poor marital prospects. This raises doubts about the recent recommendations of some scholars that we should bring back the shotgun wedding.
Aperture synthesis for microwave radiometers in space
A technique is described for obtaining passive microwave measurements from space with high spatial resolution for remote sensing applications. The technique involves measuring the product of the signal from pairs of antennas at many different antenna spacings, thereby mapping the correlation function of antenna voltage. The intensity of radiation at the source can be obtained from the Fourier transform of this correlation function. Theory is presented to show how the technique can be applied to large extended sources such as the Earth when observed from space. Details are presented for a system with uniformly spaced measurements
Bridging the gap between social tagging and semantic annotation: E.D. the Entity Describer
Semantic annotation enables the development of efficient computational methods for analyzing and interacting with information, thus maximizing its value. With the already substantial and constantly expanding data generation capacity of the life sciences as well as the concomitant increase in the knowledge distributed in scientific articles, new ways to produce semantic annotations of this information are crucial. While automated techniques certainly facilitate the process, manual annotation remains the gold standard in most domains. In this manuscript, we describe a prototype mass-collaborative semantic annotation system that, by distributing the annotation workload across the broad community of biomedical researchers, may help to produce the volume of meaningful annotations needed by modern biomedical science. We present E.D., the Entity Describer, a mashup of the Connotea social tagging system, an index of semantic web-accessible controlled vocabularies, and a new public RDF database for storing social semantic annotations
Influences on the fraction of hydrophobic and hydrophilic black carbon in the atmosphere
Black carbon (BC) is a short term climate forcer that directly warms the atmosphere, slows convection, and hinders quantification of the effect of greenhouse gases on climate change. The atmospheric lifetime of BC particles with respect to nucleation scavenging in clouds is controlled by their ability to serve as cloud condensation nuclei (CCN). To serve as CCN under typical conditions, hydrophobic BC particles must acquire hygroscopic coatings. However, the quantitative relationship between coatings and hygroscopic properties for ambient BC particles is not known nor is the time scale for hydrophobic-to-hydrophilic conversion. Here we introduce a method for measuring the hygroscopicity of externally and internally mixed BC particles by coupling a single particle soot photometer with a humidified tandem differential mobility analyzer. We test this technique using uncoated and coated laboratory generated model BC compounds and apply it to characterize the hygroscopicity distribution of ambient BC particles. From these data we derive that the observed number fraction of BC that is CCN active at 0.2% supersaturation is generally low in an urban area near sources and that it varies with the trajectory of the airmass. We anticipate that our method can be combined with measures of air parcel physical and photochemical age to provide the first quantitative estimates for characterizing hydrophobic-to-hydrophilic conversion rates in the atmosphere.Peer reviewe
Playing the odds in clinical decision making: lessons from berry aneurysms undetected by magnetic resonance angiography
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Leptonic contribution to the bulk viscosity of nuclear matter
For beta-equilibrated nuclear matter we estimate the contribution to the bulk
viscosity from purely leptonic processes, namely the conversion of electrons to
and from muons. For oscillation frequencies in the kiloHertz range, we find
that this process provides the dominant contribution to the bulk viscosity when
the temperature is well below the critical temperature for superconductivity or
superfluidity of the nuclear matter.Comment: 15 pages, LaTeX, new appendix and general clarifications in response
to referee comment
As-built design specifications of the LANDSAT Imagery Verification and Extraction System (LIVES). Volume 1: Test and appendices
There are no author-identified significant results in this report
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Design as communication: exploring the validity and utility of relating intention to interpretation
This explores the role of intention in interpreting designed artefacts. The relationship between how designers intend products to be interpreted and how they are subsequently interpreted has often been represented as a process of communication. However, such representations are attacked for allegedly implying that designers' intended meanings are somehow ‘contained’ in products and that those meanings are passively received by consumers. Instead, critics argue that consumers actively construct their own meanings as they engage with products, and therefore that designers' intentions are not relevant to this process. In contrast, this article asserts the validity and utility of relating intention to interpretation by exploring the nature of that relationship in design practice and consumer response. Communicative perspectives on design are thereby defended and new avenues of empirical enquiry are proposed
Narrative support for young game designers’ writing
Creating narrative-based computer games is a complex and challenging task. Narrative Threads is a suite of software tools designed to aid young people (aged 11-15) in creating their own narrative-based games as a writing development activity. A participatory design process highlighted the areas where additional support was required, and informed the iterative design of Narrative Threads. The tools are implemented as a plugin to a commercial game creation toolset, and constitute character and object design tools, a branching narrative diagramming tool and an augmented story map view. In this paper, we provide an overview of the design of the tools and describe an evaluation carried out with 14 children over a four-day workshop. The study examined tool usage patterns, and compared games created with Narrative Threads to those created using the standard toolset. The results suggest a number of ways in which dynamic external representations of story elements can support writing activities in narrative-based game creation. Young designers using Narrative Threads wrote more character dialogue, made stronger links between the conversations they wrote and wider game events, and designed more complex characters, compared to those using the standard toolset. In addition to showing how Narrative Threads can support young games designers, the results have broader implications for anyone looking to support storytelling and writing through game creation activities and tools
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