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An Experimental Investigation of Detonation Corner-Turning Using High Resolution Radiography
We have performed experiments investigating detonation corner turning over a range of high-explosives including LX-17, Composition B, LX-04 and Tritonal. The primary diagnostic utilized here was a new high-resolution x-ray system that was capable of recording a time sequence of the detonation process as it negotiated the corner of interest and propagated. For LX-17 our data detail the formation of a significant dead-zone. Although the detonation eventually turned the corner in LX-17, the dead zone persisted to late times and evidence exists that it never was consumed by either detonation or fast combustion processes. In LX-17 the detonations ability to corner-turn increases as the density is reduced. Furthermore, lowering the density decreases the size of the dead-zone and alters its shape. The other high-explosives investigated were able to turn the corner immediately with no indication of any dead-zone formation
Exiles in British sociology
We have all seen them, foreheads wrinkled like a ploughed field, pastel-shaded check summer shirts worn in winter, desks festooned with yellowed index cards covered in hieroglyphics, books like yours only in plainer covers and read more carefully, filthy cigarettes, an accent growing thicker with age. But we have all seen them too, the luxuriant thatch at seventy, the jacket and tie, the tidy desk, the London club and the house in the country, the pipe, the disdain for small talk made all the more intimidating by an English acquired somewhere between grammar school and Oxford. Self-contained in a way only the uprooted can be, mysterious because you never knew what questions to ask them, emissaries from worlds they have lost and you have never known: the Polish gentry, the central European peasantry, Jewish merchants, German workers and, most puzzling of all, the continental European middle class
Reinventing grounded theory: some questions about theory, ground and discovery
Grounded theory’s popularity persists after three decades of broad-ranging critique. In this article three problematic notions are discussed—‘theory,’ ‘ground’ and ‘discovery’—which linger in the continuing use and development of grounded theory procedures. It is argued that far from providing the epistemic security promised by grounded theory, these notions—embodied in continuing reinventions of grounded theory—constrain and distort qualitative inquiry, and that what is contrived is not in fact theory in any meaningful sense, that ‘ground’ is a misnomer when talking about interpretation and that what ultimately materializes following grounded theory procedures is less like discovery and more akin to invention. The procedures admittedly provide signposts for qualitative inquirers, but educational researchers should be wary, for the significance of interpretation, narrative and reflection can be undermined in the procedures of grounded theory
Voluntary organizations and society–military relations in contemporary Russia
The 2014 crisis in Ukraine has refocused attention on Russia as a European security actor. Despite showing renewed military capability, compared to the post-Soviet period, Russian society–military relations have remained the same. This relationship (between society and the security organs) provides the key context for assessing security. Analysis of everyday militarization and the role of voluntary organizations (such as DOSAAF [Dobrovol'noe obshchestvo sodeistviya armii, aviatsii i flotu] and Nashi [Molodezhnoe demokraticheskoe antifashistskoe dvizheni]) in supporting the military can provide an important insight into Russian behaviour as a security actor. These organizations generate a pro-military outlook and at the same time provide training and activities, thus contributing to military effectiveness by developing the competency of young people prior to military service as well as increasing public knowledge of military affairs. However, strong support for the military, a lack of independent information, and an absence of a shared vision on how society–military relations should be developed and also represent political challenges in terms of everyday militarization. This dynamic is important for understanding both Russia's security posture and wider security implications for Europe
Consistency and precision of cancer reporting in a multiwave national panel survey
Abstract
Background
Many epidemiological studies rely on self-reported information, the accuracy of which is critical for unbiased estimates of population health. Previously, accuracy has been analyzed by comparing self-reports to other sources, such as cancer registries. Cancer is believed to be a well-reported condition. This paper uses novel panel data to test the consistency of cancer reports for respondents with repeated self-reports.
Methods
Data come from 978 adults who reported having been diagnosed with cancer in at least one of four waves of the Panel Study of Income Dynamics, 1999-2005. Consistency of cancer occurrence reports and precision of timing of onset were studied as a function of individual and cancer-related characteristics using logistic and ordered logistic models.
Results
Almost 30% of respondents gave inconsistent cancer reports, meaning they said they never had cancer after having said they did have cancer in a previous interview; 50% reported the year of diagnosis with a discrepancy of two or more years. More recent cancers were reported with a higher consistency and timing precision; cervical cancer was reported more inaccurately than other cancer types. Demographic and socio-economic factors were only weak predictors of reporting quality.
Conclusions
Results suggest that retrospective reports of cancer contain significant measurement error. The errors, however, are fairly random across different social groups, meaning that the results based on the data are not systematically biased by socio-economic factors. Even for health events as salient as cancer, researchers should exercise caution about the presumed accuracy of self-reports, especially if the timing of diagnosis is an important covariate.http://deepblue.lib.umich.edu/bitstream/2027.42/112656/1/12963_2010_Article_108.pd
Psychiatric sequelae of low birth weight at 6 years of age
The study examined the association between low birth weight (LBW) (≤2,500 g) and attention deficit hyperactivity disorder (ADHD) in two socioeconomically disparate populations. LBW and normal birth weight (NBW) children from the 1983 to 1985 newborn lists of an urban and a suburban hospital in Southeast Michigan were randomly selected. A total of 823 children, 473 LBW and 350 NBW, participated. Data were gathered in 1990 to 1992, when the children were 6 to 7 years of age. The National Institute of Mental Health Diagnostic Interview Schedule for children—Parent version (DISC-P) was used to elicit information on DSM-III-R diagnoses of simple phobia, overanxious, separation anxiety, oppositional defiant, and ADHD. Teachers' ratings of behavior problems were obtained. LBW was associated with ADHD but not with childhood anxiety disorders or oppositional defiant disorder. The association was stronger in the urban than in the suburban population. Data from teachers' ratings revealed an association between LBW and attention problems. The prognostic significance of the observed psychopathology at 6 years of age requires follow-up assessment as the children mature.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44584/1/10802_2005_Article_BF01441637.pd
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