Proceedings of the Fifth Annual Meeting, held at Ottawa, Canada, December 28, 29 and 30, 1892

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Proceedings of the Fifth Summer Meeting, held at Madison, August 15 and 16, 1893

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Bilingualism Is Associated with a Delayed Onset of Dementia but Not with a Lower Risk of Developing it: a Systematic Review with Meta-Analyses.

Some studies have linked bilingualism with a later onset of dementia, Alzheimer's disease (AD), and mild cognitive impairment (MCI). Not all studies have observed such relationships, however. Differences in study outcomes may be due to methodological limitations and the presence of confounding factors within studies such as immigration status and level of education. We conducted the first systematic review with meta-analysis combining cross-sectional studies to explore if bilingualism might delay symptom onset and diagnosis of dementia, AD, and MCI. Primary outcomes included the age of symptom onset, the age at diagnosis of MCI or dementia, and the risk of developing MCI or dementia. A secondary outcome included the degree of disease severity at dementia diagnosis. There was no difference in the age of MCI diagnosis between monolinguals and bilinguals [mean difference: 3.2; 95% confidence intervals (CI): -3.4, 9.7]. Bilinguals vs. monolinguals reported experiencing AD symptoms 4.7 years (95% CI: 3.3, 6.1) later. Bilinguals vs. monolinguals were diagnosed with dementia 3.3 years (95% CI: 1.7, 4.9) later. Here, 95% prediction intervals showed a large dispersion of effect sizes (-1.9 to 8.5). We investigated this dispersion with a subgroup meta-analysis comparing studies that had recruited participants with dementia to studies that had recruited participants with AD on the age of dementia and AD diagnosis between mono- and bilinguals. Results showed that bilinguals vs. monolinguals were 1.9 years (95% CI: -0.9, 4.7) and 4.2 (95% CI: 2.0, 6.4) older than monolinguals at the time of dementia and AD diagnosis, respectively. The mean difference between the two subgroups was not significant. There was no significant risk reduction (odds ratio: 0.89; 95% CI: 0.68-1.16) in developing dementia among bilinguals vs. monolinguals. Also, there was no significant difference (Hedges' g = 0.05; 95% CI: -0.13, 0.24) in disease severity at dementia diagnosis between bilinguals and monolinguals, despite bilinguals being significantly older. The majority of studies had adjusted for level of education suggesting that education might not have played a role in the observed delay in dementia among bilinguals vs. monolinguals. Although findings indicated that bilingualism was on average related to a delayed onset of dementia, the magnitude of this relationship varied across different settings. This variation may be due to unexplained heterogeneity and different sources of bias in the included studies. Registration: PROSPERO CRD42015019100

Integrated control of musk thistle using an introduced weevil (1993)

Reviewed October 1, 1993

Clustering based active learning for evolving data streams

Data labeling is an expensive and time-consuming task. Choosing which labels to use is increasingly becoming important. In the active learning setting, a classifier is trained by asking for labels for only a small fraction of all instances. While many works exist that deal with this issue in non-streaming scenarios, few works exist in the data stream setting. In this paper we propose a new active learning approach for evolving data streams based on a pre-clustering step, for selecting the most informative instances for labeling. We consider a batch incremental setting: when a new batch arrives, first we cluster the examples, and then, we select the best instances to train the learner. The clustering approach allows to cover the whole data space avoiding to oversample examples from only few areas. We compare our method w.r.t. state of the art active learning strategies over real datasets. The results highlight the improvement in performance of our proposal. Experiments on parameter sensitivity are also reported

Modeling Micro-Porous Surfaces for Secondary Electron Emission Control to Suppress Multipactor

This work seeks to understand how the topography of a surface can be engineered to control secondary electron emission (SEE) for multipactor suppression. Two unique, semi-empirical models for the secondary electron yield (SEY) of a micro-porous surface are derived and compared. The first model is based on a two-dimensional (2D) pore geometry. The second model is based on a three-dimensional (3D) pore geometry. The SEY of both models is shown to depend on two categories of surface parameters: chemistry and topography. An important parameter in these models is the probability of electron emissions to escape the surface pores. This probability is shown by both models to depend exclusively on the aspect ratio of the pore (the ratio of the pore height to the pore diameter). The increased accuracy of the 3D model (compared to the 2D model) results in lower electron escape probabilities with the greatest reductions occurring for aspect ratios less than two. In order to validate these models, a variety of micro-porous gold surfaces were designed and fabricated using photolithography and electroplating processes. The use of an additive metal-deposition process (instead of the more commonly used subtractive metal-etch process) provided geometrically ideal pores which were necessary to accurately assess the 2D and 3D models. Comparison of the experimentally measured SEY data with model predictions from both the 2D and 3D models illustrates the improved accuracy of the 3D model. For a micro-porous gold surface consisting of pores with aspect ratios of two and a 50% pore density, the 3D model predicts that the maximum total SEY will be one. This provides optimal engineered surface design objectives to pursue for multipactor suppression using gold surfaces

European Corn Borer, Ostrinia nubilalis (Hbn.) Populations in Field Corn, Zea mays (L.) in the North Central United States

A long-range study of the annual changes in corn borer populations in the North Central States was started in Minnesota, Iowa, Kansas and Nebraska in 1955 and in Missouri and Ohio in 1956. This investigation was a phase of a broader Regional Project, NC-20, entitled Factors Influencing Corn Borer Populations and was undertaken to measure by standardized procedures the seasonal changes in abundance of the European corn borer, Ostrinia nubilalis (Hbn.), under cropping procedures in different locations within, the North Central States. Much valuable information has been accumulated on the abundance and effects of various physical and biotic factors on corn borer populations. Results obtained from 1955 through 1959 are summarized in a regional publication (Chiang et al. 1961). The present compilation and summary is offered as a companion bulletin containing data for the years 1960 through 1964. Although the primary purpose of the present bulletin is to present results for the 1960 to 1964 period, it seemed pertinent to include statements of comparison with the preceding 5-year\u27s work and to analyze in a rather gross way certain aspects of the population changes for the entire 10-year period. Studies of this nature are long-time projects requiring many years of work in order to evaluate population fluctuations and factors influencing them. Hence the examination of the recent 5-year period becomes more meaningful when compared with the previous 5-year period or when considered as a single 10-year period

Analysis of frame-compatible subsampling structures for efficient 3DTV broadcast

The evolution of the television market is led by 3DTV technology, and this tendency can accelerate during the next years according to expert forecasts. However, 3DTV delivery by broadcast networks is not currently developed enough, and acts as a bottleneck for the complete deployment of the technology. Thus, increasing interest is dedicated to ste-reo 3DTV formats compatible with current HDTV video equipment and infrastructure, as they may greatly encourage 3D acceptance. In this paper, different subsampling schemes for HDTV compatible transmission of both progressive and interlaced stereo 3DTV are studied and compared. The frequency characteristics and preserved frequency content of each scheme are analyzed, and a simple interpolation filter is specially designed. Finally, the advantages and disadvantages of the different schemes and filters are evaluated through quality testing on several progressive and interlaced video sequences

Sex differences in risk-based decision making in adolescents with conduct disorder

Altered decision making processes and excessive risk-seeking behaviours are key features of conduct disorder (CD). Previous studies have provided compelling evidence of abnormally increased preference for risky options, higher sensitivity to rewards, as well as blunted responsiveness to aversive outcomes in adolescents with CD. However, most studies published to date have focused on males only; thus, it is not known whether females with CD show similar alterations in decision making. The current study investigated potential sex differences in decision making and risk-seeking behaviours in adolescents with CD. Forty-nine adolescents with CD (23 females) and 51 control subjects (27 females), aged 11-18 years, performed a computerised task assessing decision making under risk—the Risky Choice Task. Participants made a series of decisions between two gamble options that varied in terms of their expected values and probability of gains and losses. This enabled the participants’ risk preferences to be determined. Taking the sample as a whole, adolescents with CD exhibited increased risk-seeking behaviours compared to healthy controls. However, we found a trend towards a sex-by-group interaction, suggesting that these effects may vary by sex. Follow-up analyses showed that males with CD made significantly more risky choices than their typically developing counterparts, while females with CD did not differ from typically developing females in their risk-seeking behaviours. Our results provide preliminary evidence that sex may moderate the relationship between CD and alterations in risk attitudes and reward processing, indicating that there may be sex differences in the developmental pathways and neuropsychological deficits that lead to CD