1,852 research outputs found
Finite element simulation of a perturbed axial-symmetric whispering-gallery mode and its use for intensity enhancement with a nanoparticle coupled to a microtoroid
We present an optical mode solver for a whispering gallery resonator coupled
to an adjacent arbitrary shaped nano-particle that breaks the axial symmetry of
the resonator. Such a hybrid resonator-nanoparticle is similar to what was
recently used for bio-detection and for field enhancement. We demonstrate our
solver by parametrically studying a toroid-nanoplasmonic device and get the
optimal nano-plasmonic size for maximal enhancement. We investigate cases near
a plasmonic resonance as well as far from a plasmonic resonance. Unlike common
plasmons that typically benefit from working near their resonance, here working
far from plasmonic resonance provides comparable performance. This is because
the plasmonic resonance enhancement is accompanied by cavity quality
degradation through plasmonic absorption.Comment: Supplementary COMSOL script, see
http://www.quantumchaos.de/Media/comsol2013/Supplement_Script_for_Fig.3_Comsol_4.3a.mp
Is a Good Student Also a Happier One? Traditional Measures of School Functioning as Predictors of Students\u27 Well-Being
Academic achievement, behavior, and school connectedness have long been considered central measures for assessing students’ optimal functioning in school. With the growing interest in positive education and its’ inclusion of well-being as a central educational goal, attention has been turned to the extent to which these traditional measures of school functioning are related to students’ well-being. Based on a sample of 314 Israeli middle school students from one school, this study focuses on the relationship between the latter measures of school functioning and students’ well-being, operationalized as life satisfaction, positive and negative affect, hope, and gratitude. Using structural equational modelling, our findings revealed that GPA, teachers’ reports of disruptive behavior, and students’ reports of school connectedness predict students’ well-being, with school connectedness as the strongest predictor of all five well-being measures. This suggests that a sense of connectedness is more crucial to students’ well-being than their academic achievements or behavior in school. Surprisingly, students’ disruptive behavior as reported by teachers was slightly, but significantly, positively associated with life satisfaction, hope and positive affect. Further inquiry into this curious finding revealed that disruptive behavior is related to higher well-being primarily for students of middle range academic attainment (GPA of 64-84) when controlling for connectedness to school. Based on this finding, we suggest that within the school context better behavior among average achievers may be a potential sign of a maladaptive response to being left outside the schools’ radar while disruptive behavior among average achievers may in fact be the more resilient response. Attention is given to this interpretation of the finding as well as to more general implications of the importance of school connectedness for students’ well-being
Conversion-Based Dynamic-Creative-Optimization in Native Advertising
Yahoo Gemini native advertising marketplace serves billions of impressions
daily, to hundreds millions of unique users, and reaches a yearly revenue of
many hundreds of millions USDs. Powering Gemini native models for predicting
advertise (ad) event probabilities, such as conversions and clicks, is OFFSET -
a feature enhanced collaborative-filtering (CF) based event prediction
algorithm. The predicted probabilities are then used in Gemini native auctions
to determine which ads to present for every serving event (impression). Dynamic
creative optimization (DCO) is a recent Gemini native product that was launched
two years ago and is increasingly gaining more attention from advertisers. The
DCO product enables advertisers to issue several assets per each native ad
attribute, creating multiple combinations for each DCO ad. Since different
combinations may appeal to different crowds, it may be beneficial to present
certain combinations more frequently than others to maximize revenue while
keeping advertisers and users satisfied. The initial DCO offer was to optimize
click-through rates (CTR), however as the marketplace shifts more towards
conversion based campaigns, advertisers also ask for a {conversion based
solution. To accommodate this request, we present a post-auction solution,
where DCO ads combinations are favored according to their predicted conversion
rate (CVR). The predictions are provided by an auxiliary OFFSET based
combination CVR prediction model, and used to generate the combination
distributions for DCO ad rendering during serving time. An online evaluation of
this explore-exploit solution, via online bucket A/B testing, serving Gemini
native DCO traffic, showed a 53.5% CVR lift, when compared to a control bucket
serving all combinations uniformly at random.Comment: Accepted to IEEE Big Data 2022 conferenc
Audience Prospecting for Dynamic-Product-Ads in Native Advertising
With yearly revenue exceeding one billion USD, Yahoo Gemini native
advertising marketplace serves more than two billion impressions daily to
hundreds of millions of unique users. One of the fastest growing segments of
Gemini native is dynamic-product-ads (DPA), where major advertisers, such as
Amazon and Walmart, provide catalogs with millions of products for the system
to choose from and present to users. The subject of this work is finding and
expanding the right audience for each DPA ad, which is one of the many
challenges DPA presents. Approaches such as targeting various user groups,
e.g., users who already visited the advertisers' websites (Retargeting), users
that searched for certain products (Search-Prospecting), or users that reside
in preferred locations (Location-Prospecting), have limited audience expansion
capabilities. In this work we present two new approaches for audience expansion
that also maintain predefined performance goals. The Conversion-Prospecting
approach predicts DPA conversion rates based on Gemini native logged data, and
calculates the expected cost-per-action (CPA) for determining users'
eligibility to products and optimizing DPA bids in Gemini native auctions. To
support new advertisers and products, the Trending-Prospecting approach matches
trending products to users by learning their tendency towards products from
advertisers' sites logged events. The tendency scores indicate the popularity
of the product and the similarity of the user to those who have previously
engaged with this product. The two new prospecting approaches were tested
online, serving real Gemini native traffic, demonstrating impressive DPA
delivery and DPA revenue lifts while maintaining most traffic within the
acceptable CPA range (i.e., performance goal). After a successful testing
phase, the proposed approaches are currently in production and serve all Gemini
native traffic.Comment: In Proc. IeeeBigData'2023 (Industry and Government Program
A study of subjective well-being, resilience, and risk of PTSD among Israeli adolescents exposed to terrorism
While many studies have analyzed the role of subjective well-being components in building psychological resilience in times of stress, there is also evidence that certain aspects of well-being may be tied to increased risk of psychological distress in the aftermath of a traumatic event. Based on a sample of 368 Israeli adolescents surveyed before and after a bout of missile attacks on their city, this study investigates (a) the relationship between subjective well-being components (hope, life satisfaction, and positive and negative affect) and PTSD, thereby assessing their role as protective or risk factors, and (b) changes in the latter well-being measures from before to after the attacks, thereby assessing individuals’ ability to “bounce back” to prior levels of well-being. Using structural educational modeling, our study revealed that life satisfaction was the only subjective well-being factor before the attacks to serve as a protective factor against PTSD symptoms. Negative affect and hope before the attacks served as direct risk factors, while positive affect served as an indirect risk factor. There was a significant increase in hope from before to after the missile attacks, with no change in other well-being measures. Implications of these finding are discussed
Transfer of noncoding DNA drives regulatory rewiring in bacteria
Understanding the mechanisms that generate variation is a common pursuit unifying the life sciences. Bacteria represent an especially striking puzzle, because closely related strains possess radically different metabolic and ecological capabilities. Differences in protein repertoire arising from gene transfer are currently considered the primary mechanism underlying phenotypic plasticity in bacteria. Although bacterial coding plasticity has been extensively studied in previous decades, little is known about the role that regulatory plasticity plays in bacterial evolution. Here, we show that bacterial genes can rapidly shift between multiple regulatory modes by acquiring functionally divergent nonhomologous promoter regions. Through analysis of 270,000 regulatory regions across 247 genomes, we demonstrate that regulatory “switching” to nonhomologous alternatives is ubiquitous, occurring across the bacterial domain. Using comparative transcriptomics, we show that at least 16% of the expression divergence between Escherichia coli strains can be explained by this regulatory switching. Further, using an oligonucleotide regulatory library, we establish that switching affects bacterial promoter architecture. We provide evidence that regulatory switching can occur through horizontal regulatory transfer, which allows regulatory regions to move across strains, and even genera, independently from the genes they regulate. Finally, by experimentally characterizing the fitness effect of a regulatory transfer on a pathogenic E. coli strain, we demonstrate that regulatory switching elicits important phenotypic consequences. Taken together, our findings expose previously unappreciated regulatory plasticity in bacteria and provide a gateway for understanding bacterial phenotypic variation and adaptation.National Science Foundation (U.S.) (Grant DEB-0936234
Biological treatment for bullous pemphigoid
BackgroundBullous pemphigoid (BP) is the most common autoimmune subepidermal bullous disease. Topical or systemic corticosteroids are often used as the first-line treatment. However, long-term corticosteroid use may lead to significant side effects. Therefore, various adjuvant immunosuppressant therapies are used as steroid-sparing agents, with accumulating reports of biological treatments for severely recalcitrant BP.ObjectiveTo describe the clinical and immunological features of a series of patients with recalcitrant BP treated with immunobiological therapies. To assess the efficacy and safety of their therapies.MethodsPatients receiving biological treatment for BP from two centers were assessed. Here, we described the clinical, immunopathological, and immunofluorescence findings of adult patients with BP and analyzed the clinical response and adverse events associated with various biological therapies.ResultsWe identified nine eligible patients treated with rituximab (seven), omalizumab (three), or dupilumab (one). The mean age at diagnosis was 60.4 years, the average BP duration before biologic initiation was 1.9 years, and the average previous treatment failure was 2.11 therapies. The mean follow-up period from the first biological treatment to the last visit was 29.3 months. Satisfactory response, defined as clinical improvement, was achieved in 78% (7) of the patients, and total BP clearance was achieved in 55% (5) of the patients at the last follow-up visit. Additional rituximab courses improved the disease outcomes. No adverse events were reported.ConclusionsEfficient and safe novel therapies can be considered in recalcitrant steroid-dependent BP non-responsive to conventional immunosuppressant therapies
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