596 research outputs found
The elastic-plastic stability of stanchions bent about two axes
Imperial Users onl
Itâs What Happens on the Front Lines of Civic Education Policy that Matters: Reflections on a Natural Experiment on Youth Turnout in Ontario
In the last decade there has developed a new level of coordination among those working in the fields of citizenship education and political participation. The paper puts this link to an empirical test, using a natural experiment of youth turnout in the 2004 and 2006 federal election to investigate what, if any, effect can be found of Ontarioâs introduction of a compulsory Grade 10 Civics course in 2000. We find that changing the curriculum in itself does not appear to have the desired results, concluding that, in practice, any lasting effect of civic education upon youth political participation rests on the effectiveness of front-line implementation
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Systems and methods for altering visual acuity
Provided are systems operable to effect a temporary change in a modulation transfer function (MTF) of a target imaging system. The systems include a light source operable to produce light for transient propagation onto at least a portion of the target imaging system, a power source in operative communication with the light source and configured to effect the production of light from the light source, and a transmission unit in operative communication with the light source and configured to propagate the produced light onto at least a portion of the target imaging system. The propagated light is configured for absorbance by the portion of the target imaging system; the absorbance causes an increase in temperature and a change in a refractive index profile of at least the portion of the imaging system. The change in refractive index profile produces a temporary change in the MTF of the imaging system.Board of Regents, University of Texas Syste
BlinkDB: queries with bounded errors and bounded response times on very large data
In this paper, we present BlinkDB, a massively parallel, approximate query engine for running interactive SQL queries on large volumes of data. BlinkDB allows users to trade-off query accuracy for response time, enabling interactive queries over massive data by running queries on data samples and presenting results annotated with meaningful error bars. To achieve this, BlinkDB uses two key ideas: (1) an adaptive optimization framework that builds and maintains a set of multi-dimensional stratified samples from original data over time, and (2) a dynamic sample selection strategy that selects an appropriately sized sample based on a query's accuracy or response time requirements. We evaluate BlinkDB against the well-known TPC-H benchmarks and a real-world analytic workload derived from Conviva Inc., a company that manages video distribution over the Internet. Our experiments on a 100 node cluster show that BlinkDB can answer queries on up to 17 TBs of data in less than 2 seconds (over 200 x faster than Hive), within an error of 2-10%.National Science Foundation (U.S.) (CISE Expeditions Award CCF-1139158)United States. Defense Advanced Research Projects Agency (XData Award FA8750-12-2-0331)
Electrocerebral Recovery During the Intracarotid Amobarbital Procedure: Influence of Interval Between Injections
Purpose and Methods : During the intracarotid amobarbital procedure (IAP) at the University of Michigan, continuous scalp EEG monitoring guides the timing for presentation of memory items and postinjection testing. Most of our patients have undergone bilateral injections. The interval between injections varied from 22 to 60 min, depending on the test and recovery time, as well as the time to catheterize the second side. After noting a trend toward prolonged electro-graphic recovery following the second injection, we tested our clinical impression that recovery of the second hemisphere may be influenced by (a) the time between injections and (b) which hemisphere is injected first (epileptogenic or nonepileptogenic). To study these questions, we analyzed EEG recovery data from 48 consecutive IAPs. Approximately half the patients had the epileptogenic side injected first. Results : We found that (a) electrographic recovery after the second injection is prolonged if the interval between bilateral injections is less than 40 minutes and (b) electrographic recovery is more rapid after injection of the epileptogenic hemisphere. Conclusions : We now recommend waiting at least 45 min between injections. The pathophysiology of more prolonged amobarbital effect on the nonepileptogenic hemisphere than on the epileptogenic hemisphere remains unclear.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65275/1/j.1528-1157.1997.tb00067.x.pd
Knowing when you're wrong: Building fast and reliable approximate query processing systems
Modern data analytics applications typically process massive amounts of data on clusters of tens, hundreds, or thousands of machines to support near-real-time decisions.The quantity of data and limitations of disk and memory bandwidth often make it infeasible to deliver answers at interactive speeds. However, it has been widely observed that many applications can tolerate some degree of inaccuracy. This is especially true for exploratory queries on data, where users are satisfied with "close-enough" answers if they can come quickly. A popular technique for speeding up queries at the cost of accuracy is to execute each query on a sample of data, rather than the whole dataset. To ensure that the returned result is not too inaccurate, past work on approximate query processing has used statistical techniques to estimate "error bars" on returned results. However, existing work in the sampling-based approximate query processing (S-AQP) community has not validated whether these techniques actually generate accurate error bars for real query workloads. In fact, we find that error bar estimation often fails on real world production workloads. Fortunately, it is possible to quickly and accurately diagnose the failure of error estimation for a query. In this paper, we show that it is possible to implement a query approximation pipeline that produces approximate answers and reliable error bars at interactive speeds.National Science Foundation (U.S.) (CISE Expeditions Award CCF-1139158)Lawrence Berkeley National Laboratory (Award 7076018)United States. Defense Advanced Research Projects Agency (XData Award FA8750-12-2-0331)Amazon.com (Firm)Google (Firm)SAP CorporationThomas and Stacey Siebel FoundationApple Computer, Inc.Cisco Systems, Inc.Cloudera, Inc.EMC CorporationEricsson, Inc.Facebook (Firm
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Executive function in Williams and Down syndromes
Williams (WS) and Down (DS) syndromes are characterised by roughly opposing ability profiles. Relative verbal strengths and visuospatial difficulties have been reported in those with WS, while expressive language difficulties have been observed in individuals with DS. Few investigations into the executive function (EF) skills of these groups have examined the effect of verbal/visuospatial task type on performance. Analogous verbal and visuospatial measures were administered to these populations within four EF domains: executive-loaded working memory (ELWM), inhibition, fluency and set-shifting. Performance in both groups was compared to that of typically developing (TD) children using regression techniques controlling for potentially influential cognitive/developmental factors. Individuals with WS showed the expected relative visuospatial difficulties, as indicated by poorer performance than TD individuals, on tests of ELWM and fluency. Individuals with DS displayed the expected relative verbal difficulty in the domain of set-shifting. In addition, each population showed pervasive deficits across modality in one domain; ELWM for individuals with DS, and inhibition for individuals with WS. Individuals with WS and DS showed EF difficulties in comparison to a TD group, but, their executive performance was affected by EF task type (verbal/visuospatial) and EF domain in different ways. While the findings indicated that EF in these populations is characterised by a range of specific strengths and weaknesses, it was also suggested that the relative verbal/visuospatial strengths associated with each population do not consistently manifest across EF domains. Lastly, syndrome specificity was indicated by the differences in groupsâ performance patterns
The CBM-opathiesâA Rapidly Expanding Spectrum of Human Inborn Errors of Immunity Caused by Mutations in the CARD11-BCL10-MALT1 Complex
The caspase recruitment domain family member 11 (CARD11 or CARMA1)âB cell CLL/lymphoma 10 (BCL10)âMALT1 paracaspase (MALT1) [CBM] signalosome complex serves as a molecular bridge between cell surface antigen receptor signaling and the activation of the NF-ÎșB, JNK, and mTORC1 signaling axes. This positions the CBM complex as a critical regulator of lymphocyte activation, proliferation, survival, and metabolism. Inborn errors in each of the CBM components have now been linked to a diverse group of human primary immunodeficiency diseases termed âCBM-opathies.â Clinical manifestations range from severe combined immunodeficiency to selective B cell lymphocytosis, atopic disease, and specific humoral defects. This surprisingly broad spectrum of phenotypes underscores the importance of âtuningâ CBM signaling to preserve immune homeostasis. Here, we review the distinct clinical and immunological phenotypes associated with human CBM complex mutations and introduce new avenues for targeted therapeutic intervention
Factors related to work and life satisfaction of veterinary practitioners in Germany
Objectives: Veterinary practitionersâ working situation is both challenging
and changing. They have higher levels of work-related stress and suicide risk
than the general population. The proportion of women is increasing, and in
Germany especially women and employed veterinarians are reported to be less
satisfied than comparable subgroups of the general population. In this study
we identified key factors associated with work and life satisfaction among
veterinary practitioners in Germany. Design: Questionnaire-based cross-
sectional survey. Setting: All veterinary practitioners registered in Germany
in 2016. Participants: There were 2549 respondents, of whom 1930 met the
inclusion criteria for further analysis. They had a median age of 37 and the
majority of respondents were women (79.3 per cent). Almost two-thirds (63.8
per cent) worked as employed veterinarian. Primary outcomes: Importance of
different job characteristics measured in 5-point Likert items, work
satisfaction measured on a 5-point Likert item and life satisfaction measured
in 11-point Likert items. Secondary outcomes: Facets such as satisfaction with
leisure time, family life, health and standard of living, information on
working conditions such as working time, income, as well as year of birth and
other demographic data. Results: A âgood working atmosphereâ was the most
relevant job characteristic for all veterinary practitioners. Work
satisfaction of employed practitioners is closely linked to satisfaction with
their colleagues. This link is less pronounced for self-employed
practitioners. A âreasonable salaryâ was the second and âholidays and leisure
timeâ was the third most important job characteristics for employed
practitioners. A âgood working atmosphereâ and âfamily friendly arrangementsâ
were statistically significantly more important for women than for men, while
a âreasonable salaryâ was more important for men. Conclusions: Our results
indicate strong associations between levels of work satisfaction and various
work-related factors in subgroups of veterinary practitioners in Germany that
reduce life satisfaction. The strength of some associations differs between
men and women, as well as between self-employed and employed veterinarians.
Outgoing students should be better prepared for the challenging working
conditions that they face in veterinary practice. Salary levels should be
improved and the working conditions adapted to the respective subgroups in
order to increase work and life satisfaction
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