1,188 research outputs found

    An Exploratory Study of Forces and Frictions affecting Large-Scale Model-Driven Development

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    In this paper, we investigate model-driven engineering, reporting on an exploratory case-study conducted at a large automotive company. The study consisted of interviews with 20 engineers and managers working in different roles. We found that, in the context of a large organization, contextual forces dominate the cognitive issues of using model-driven technology. The four forces we identified that are likely independent of the particular abstractions chosen as the basis of software development are the need for diffing in software product lines, the needs for problem-specific languages and types, the need for live modeling in exploratory activities, and the need for point-to-point traceability between artifacts. We also identified triggers of accidental complexity, which we refer to as points of friction introduced by languages and tools. Examples of the friction points identified are insufficient support for model diffing, point-to-point traceability, and model changes at runtime.Comment: To appear in proceedings of MODELS 2012, LNCS Springe

    The Strengths of Phenolic Ketimines and Their Methyl Ethers as Bases

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    The ionization constants of the monohydroxy-diphenyl ketimines and their methyl ethers are calculated from measurements of the hydrogen ion concentration of aqueous solutions of their hydrochlorides through the use of the quinhydrone electrode. This data has been collected as a part of the information expected to throw light on the varied stability toward hydrolysis shown by different ketimines

    Decisions at the Brink: Locomotor Experience Affects Infants’ Use of Social Information on an Adjustable Drop-off

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    How do infants decide what to do at the brink of a precipice? Infants could use two sources of information to guide their actions: perceptual information generated by their own exploratory activity and social information offered by their caregivers. The current study investigated the role of locomotor experience in using social information—both encouragement and discouragement—for descending drop-offs. Mothers of 30 infants (experienced 12-month-old crawlers, novice 12-month-old walkers, and experienced 18-month-old walkers) encouraged and discouraged descent on a gradation of dropoffs (safe “steps” and risky “cliffs”). Novice walkers descended more frequently than experienced crawlers and walkers and fell while attempting to walk over impossibly high cliffs. All infants showed evidence of integrating perceptual and social information, but locomotor experience affected infants’ use of social messages, especially on risky dropoffs. Experienced crawlers and walkers selectively deferred to social information when perceptual information is ambiguous. In contrast, novice walkers took mothers’ advice inconsistently and only at extreme drop-offs

    Functional Properties of Subretinal Transplants in Rabbit

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    The ties that bind: Cradling in Tajikistan

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    A traditional childrearing practice—“gahvora” cradling—in Tajikistan and other parts of Central Asia purportedly restricts movement of infants’ body and limbs. However, the practice has been documented only informally in anecdotal reports. Thus, this study had two research questions: (1) To what extent are infants’ movements restricted in the gahvora? (2) How is time in the gahvora distributed over a 24-hour day in infants from 1–24 months of age? To answer these questions, we video-recorded 146 mothers cradling their infants and interviewed them using 24-hour time diaries to determine the distribution of time infants spent in the gahvora within a day and across age. Infants’ movements were indeed severely restricted. Although mothers showed striking uniformity in how they restricted infants’ movements, they showed large individual differences in amount and distribution of daily use. Machine learning algorithms yielded three patterns of use: day and nighttime cradling, mostly nighttime cradling, and mostly daytime cradling, suggesting multiple functions of the cradling practice. Across age, time in the gahvora decreased, yet 20% of 12- to 24-montholds spent more than 15 hours bound in the gahvora. We discuss the challenges and benefits of cultural research, and how the discovery of new phenomena may defy Western assumptions about childrearing and development. Future work will determine whether the extent and timing of restriction impacts infants’ physical and psychological development

    Ultrastructural Circuitry in Retinal Cell Transplants to Rat Retina

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    The development of five transplants of fetal retinal tissue to adult rat eyes was examined with the electron microscope. The transplants were of 9 to 10 weeks total age after conception in four cases and 20 weeks in one case. They were at stage E15 when transplanted. Transplants developed in both the epiretinal and subretinal spaces

    Oral health in relation to all-cause mortality: the IPC cohort study

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    We evaluated the association between oral health and mortality. The study population comprised 76,188 subjects aged 16–89 years at recruitment. The mean follow-up time was 3.4 ± 2.4 years. Subjects with a personal medical history of cancer or cardiovascular disease and death by casualty were excluded from the analysis. A full-mouth clinical examination was performed in order to assess dental plaque, dental calculus and gingival inflammation. The number of teeth and functional masticatory units 10 missing teeth and functional masticatory units 10 missing teeth (HR = 2.31, [95% CI: 1.40–3.82]) and functional masticatory units <5 (HR = 2.40 [95% CI 1.55–3.73]). Moreover, when ≥3 oral diseases were cumulated in the model, the risk increased for all-cause mortality (HR = 3.39, [95% CI: 2.51–5.42]), all-cancer mortality (HR = 3.59, [95% CI: 1.23–10.05]) and non-cardiovascular and non-cancer mortality (HR = 4.71, [95% CI: 1.74–12.7]). The present study indicates a postive linear association between oral health and mortality

    Designing and implementing a communications strategy: lessons learnt from HIV and Sexual and Reproductive Health Research Programme Consortia.

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    In recent years there has been increasing recognition of the importance of strategic research communication. Health research organisations need to be able to communicate their research effectively to increase the probability that the findings influence policy and practice, and benefit those in greatest need. Many research funders are making communications a requirement of research funding. This paper reflects on the experience in developing and implementing communications strategies of several Research Programme Consortia funded by the Department for International Development.Different research topics will require different communications approaches in order to be effective. This is reflected in the diversity of strategies employed by different research programmes. Strategic research communications designed to influence policy and practice require different skills and expertise from those required for carrying out research and writing it up for publication in academic journals. Therefore researchers involved in communicating research should be supported in this work. One of the ways in which research programme consortia have sought to do this is through convening workshops to develop the communications skills of researchers from partner organisations. These have proven invaluable. Another way of providing ongoing support to those involved in communicating research is through a Communications Community of Practice. Where this has been used it has proven a good way to support researchers both with ideas and resources, but also a strong sense of belonging to a community that shares a common concern with communication. Developing strong partnerships with research users, other research organisations, knowledge intermediaries and other stakeholders is vital for effective communication.Embracing the challenges and opportunities presented by communicating research to influence policy practice is vital if research is to have maximum possible impact, and demonstrate its worth at a time when funding for health and development activities is at risk. Sharing lessons learnt in this process between research programmes is important to support this work

    Density Functional Study of Cubic to Rhombohedral Transition in α\alpha-AlF3_3

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    Under heating, α\alpha-AlF3_3 undergoes a structural phase transition from rhombohedral to cubic at temperature TT around 730 K. The density functional method is used to examine the TT=0 energy surface in the structural parameter space, and finds the minimum in good agreement with the observed rhombohedral structure. The energy surface and electronic wave-functions at the minimum are then used to calculate properties including density of states, Γ\Gamma-point phonon modes, and the dielectric function. The dipole formed at each fluorine ion in the low temperature phase is also calculated, and is used in a classical electrostatic picture to examine possible antiferroelectric aspects of this phase transition.Comment: A 6-page manuscript with 4 figures and 4 table
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