Mie and bragg plasmons in subwavelength silver semi-shells

2D arrays of silver semi-shells of 100 and 200 nm diameter display complex reflection and transmission spectra in the visible and near-IR. Here these spectral features are deconstructed and it is demonstrated that they result from the coupling of incident light into a delocalized Bragg plasmon, and the latter's induction of localized Mie plasmons in the arrays. These phenomena permit the excitation of transverse dipolar plasmon resonances in the semi-shells despite an ostensibly unfavorable orientation with respect to normally incident light. The resulting spectral feature in the mid-visible is strong and tunable. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA

EXCITATION CONDITIONS IN THE MULTI-COMPONENT SUBMILLIMETER GALAXY SMM J00266+1708

We present multiline CO observations of the complex submillimeter galaxy SMMJ00266+1708. Using the Zpectrometer on the Green Bank Telescope, we provide the first precise spectroscopic measurement of its redshift (z = 2.742). Based on followup CO(1–0), CO(3–2), and CO(5–4) mapping, SMMJ00266+1708 appears to have two distinct components separated by ∼ 500 kms−1 that are nearly coincident along our line of sight. The two components show hints of different kinematics, with the blue-shifted component dispersion-dominated and the red-shifted component showing a clear velocity gradient. CO line ratios differ slightly between the two components, indicating that the physical conditions in their molecular gas may not be alike. We tentatively infer that SMMJ00266+1708 is an on going merger with a mass ratio of (7.8±4.0)/ sin2(i), with its overall size and surface brightness closely resembling that of other merging systems. We perform large velocity gradient modeling of the CO emission from both components and find that each component’s properties are consistent with a single phase of molecular gas (i.e., a single temperatures and density); additional multi-phase modelling of the red-shifted component, although motivated by a CO(1–0) size larger than the CO(3–2) size, is inconclusive. SMMJ00266+1708 provides evidence of early stage mergers within the submillimeter galaxy population. Continuum observations of J00266 at the ∼ 1′′ resolution of our observations could not have distinguished between the two components due to their separation (0.′′73 ± 0.′′06), illustrating that the additional velocity information provided by spectral line studies is important for addressing the prevalence of unresolved galaxy pairs in low-resolution submillimeter surveys

Excitation Conditions in the Multi-component Submillimeter Galaxy SMM J00266+1708

We present multiline CO observations of the complex submillimeter galaxy SMM J00266+1708. Using the Zpectrometer on the Green Bank Telescope, we provide the first precise spectroscopic measurement of its redshift (z=2.742). Based on followup CO(1-0), CO(3-2), and CO(5-4) mapping, SMM J00266+1708 appears to have two distinct components separated by ~500 km/s that are nearly coincident along our line of sight. The two components show hints of different kinematics, with the blue-shifted component dispersion-dominated and the red-shifted component showing a clear velocity gradient. CO line ratios differ slightly between the two components, indicating that the physical conditions in their molecular gas may not be alike. We tentatively infer that SMM J00266+1708 is an ongoing merger with a mass ratio of (7.8+/-4.0)/sin^2(i), with its overall size and surface brightness closely resembling that of other merging systems. We perform large velocity gradient modeling of the CO emission from both components and find that each component's properties are consistent with a single phase of molecular gas (i.e., a single temperatures and density); additional multi-phase modeling of the red-shifted component, although motivated by a CO(1-0) size larger than the CO(3-2) size, is inconclusive. SMM J00266+1708 provides evidence of early stage mergers within the submillimeter galaxy population. Continuum observations of J00266 at the ~1" resolution of our observations could not have distinguished between the two components due to their separation (0.73" +/- 0.06"), illustrating that the additional velocity information provided by spectral line studies is important for addressing the prevalence of unresolved galaxy pairs in low-resolution submillimeter surveys

Greater than the parts: a review of the information decomposition approach to causal emergence.

Emergence is a profound subject that straddles many scientific disciplines, including the formation of galaxies and how consciousness arises from the collective activity of neurons. Despite the broad interest that exists on this concept, the study of emergence has suffered from a lack of formalisms that could be used to guide discussions and advance theories. Here, we summarize, elaborate on, and extend a recent formal theory of causal emergence based on information decomposition, which is quantifiable and amenable to empirical testing. This theory relates emergence with information about a system's temporal evolution that cannot be obtained from the parts of the system separately. This article provides an accessible but rigorous introduction to the framework, discussing the merits of the approach in various scenarios of interest. We also discuss several interpretation issues and potential misunderstandings, while highlighting the distinctive benefits of this formalism. This article is part of the theme issue 'Emergent phenomena in complex physical and socio-technical systems: from cells to societies'

Spectrally and temporally resolved estimation of neural signal diversity

Quantifying the complexity of neural activity has provided fundamental insights into cognition, consciousness, and clinical conditions. However, the most widely used approach to estimate the complexity of neural dynamics, Lempel-Ziv complexity (LZ), has fundamental limitations that substantially restrict its domain of applicability. In this article we leverage the information-theoretic foundations of LZ to overcome these limitations by introducing a complexity estimator based on state-space models — which we dub Complexity via State-space Entropy Rate (CSER). While having a performance equivalent to LZ in discriminating states of consciousness, CSER boasts two crucial advantages: 1) CSER offers a principled decomposition into spectral components, which allows us to rigorously investigate the relationship between complexity and spectral power; and 2) CSER provides a temporal resolution two orders of magnitude better than LZ, which allows complexity analyses of e.g. event-locked neural signals. As a proof of principle, we use MEG, EEG and ECoG datasets of humans and monkeys to show that CSER identifies the gamma band as the main driver of complexity changes across states of consciousness; and reveals early entropy increases that precede the standard ERP in an auditory mismatch negativity paradigm by approximately 20ms. Overall, by overcoming the main limitations of LZ and substantially extending its range of applicability, CSER opens the door to novel investigations on the fine-grained spectral and temporal structure of the signal complexity associated with cognitive processes and conscious states

Mutant p53 cancers reprogram macrophages to tumor supporting macrophages via exosomal miR-1246

TP53 mutants (mutp53) are involved in the pathogenesis of most human cancers. Specific mutp53 proteins gain oncogenic functions (GOFs) distinct from the tumor suppressor activity of the wild-type protein. Tumor-associated macrophages (TAMs), a hallmark of solid tumors, are typically correlated with poor prognosis. Here, we report a non-cell-autonomous mechanism, whereby human mutp53 cancer cells reprogram macrophages to a tumor supportive and anti-inflammatory state. The colon cancer cells harboring GOF mutp53 selectively shed miR-1246-enriched exosomes. Uptake of these exosomes by neighboring macrophages triggers their miR-1246-dependent reprogramming into a cancerpromoting state. Mutp53-reprogammed TAMs favor anti-inflammatory immunosuppression with increased activity of TGF-β. These findings, associated with poor survival in colon cancer patients, strongly support a microenvironmental GOF role for mutp53 in actively engaging the immune system to promote cancer progression and metastasis

Empirical Evidence on the Use of Credit Scoring for Predicting Insurance Losses with Psycho-social and Biochemical Explanations

An important development in personal lines of insurance in the United States is the use of credit history data for insurance risk classification to predict losses. This research presents the results of collaboration with industry conducted by a university at the request of its state legislature. The purpose was to see the viability and validity of the use of credit scoring to predict insurance losses given its controversial nature and criticism as redundant of other predictive variables currently used. Working with industry and government, this study analyzed more than 175,000 policyholders’ information for the relationship between credit score and claims. Credit scores were significantly related to incurred losses, evidencing both statistical and practical significance. We investigate whether the revealed relationship between credit score and incurred losses was explainable by overlap with existing underwriting variables or whether the credit score adds new information about losses not contained in existing underwriting variables. The results show that credit scores contain significant information not already incorporated into other traditional rating variables (e.g., age, sex, driving history). We discuss how sensation seeking and self-control theory provide a partial explanation of why credit scoring works (the psycho-social perspective). This article also presents an overview of biological and chemical correlates of risk taking that helps explain why knowing risk-taking behavior in one realm (e.g., risky financial behavior and poor credit history) transits to predicting risk-taking behavior in other realms (e.g., automobile insurance incurred losses). Additional research is needed to advance new nontraditional loss prediction variables from social media consumer information to using information provided by technological advances. The evolving and dynamic nature of the insurance marketplace makes it imperative that professionals continue to evolve predictive variables and for academics to assist with understanding the whys of the relationships through theory development.IC2 Institut

Autonomous vehicle decision-making: Should we be bio-inspired?

© Springer International Publishing AG 2017. On our crowded roads, drivers must compete for space but cooperate to avoid occupying the same space at the same time. Decision-making is strategic and requires mutual understanding of other’s choices. Fully autonomous vehicles (AVs) will need risk management software to make these types strategic decisions without human arbitration. Accidents will occur, and what constitutes rational and ‘safe’ decisions will be scrutinized by the legal system. It is far from clear how AV-Human and AV-AV interactions should be managed. Game Theory provides a framework for analyzing mutual ‘games’ with 2 or more players. It assumes that players mutually optimize their outcomes according to Nash equilibria (NE), but do humans follow Nash equilibria in Human-Human interactions? We implemented simple two-player competitive games to see whether people played rationally according to Nash equilibria. On each of 100 trials, each player was instructed to maximise their reward by pressing one of three buttons labelled “4”, “6”, and “12”, without knowing the other players choice. If players pressed different buttons, they received a reward of 4, 6, or 12 points accordingly. If players pressed the same button, the reward was reduced depending on the game type. Results showed that players did not follow NE, but played a probabilistic game that included the “4” button, even though pressing this button is always suboptimal. We suggest that this may be an evolutionary strategy, but it clearly shows that people do not follow the ‘rational’ Nash strategy. It seems that AV-human interactions will be probabilistic. In AV-AV interactions, software may be playing itself, and may also require probabilistic optimal evolutionary-type strategies. We doubt that the full implications of autonomous decision-making have been fully worked out. Whether probabilistic decisions will tolerated legally and actuarially is doubtful. One way to avoid them would be to allow regulated AV-AV communications, and force software decisions to be deterministic according to some protocol. However, AV-Human interactions seem likely to remain problematic

No imminent quantum supremacy by boson sampling

It is predicted that quantum computers will dramatically outperform their conventional counterparts. However, large-scale universal quantum computers are yet to be built. Boson sampling is a rudimentary quantum algorithm tailored to the platform of photons in linear optics, which has sparked interest as a rapid way to demonstrate this quantum supremacy. Photon statistics are governed by intractable matrix functions known as permanents, which suggests that sampling from the distribution obtained by injecting photons into a linear-optical network could be solved more quickly by a photonic experiment than by a classical computer. The contrast between the apparently awesome challenge faced by any classical sampling algorithm and the apparently near-term experimental resources required for a large boson sampling experiment has raised expectations that quantum supremacy by boson sampling is on the horizon. Here we present classical boson sampling algorithms and theoretical analyses of prospects for scaling boson sampling experiments, showing that near-term quantum supremacy via boson sampling is unlikely. While the largest boson sampling experiments reported so far are with 5 photons, our classical algorithm, based on Metropolised independence sampling (MIS), allowed the boson sampling problem to be solved for 30 photons with standard computing hardware. We argue that the impact of experimental photon losses means that demonstrating quantum supremacy by boson sampling would require a step change in technology.Comment: 25 pages, 9 figures. Comments welcom

Socioeconomic factors from midlife predict mobility limitation and depressed mood three decades later; findings from the AGES-Reykjavik Study.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.Taking into account our rapidly ageing population, older people are of particular interest in studying health inequalities. Most studies of older persons only include measures of current socioeconomic status (SES) and do not take into account data from earlier stages of life. In addition, only classic SES measures are used, while alternative measures, such as car ownership and house ownership, might equally well predict health. The present study aims to examine the effect of midlife socioeconomic factors on mobility limitation and depressed mood three decades later.Data were from 4,809 men and women aged 33-65 years who participated in the Reykjavik Study (1967-1992) and who were re-examined in old age in the Age, Gene/Environment Susceptibility (AGES) -Reykjavik Study (2002-2006).Education and occupation predicted mobility limitation and depressed mood. Independently, home and car ownership and the availability of housing features predicted mobility limitation. Shortages of food in childhood and lack of a car in midlife predicted depressed mood.Socioeconomic factors from midlife and from childhood affect mobility limitation and depressed mood in old age. Prevention of health problems in old age should begin as early as midlife.NIH/N01-AG-12100 NIA Intramural Research Program Hjartavernd (the Icelandic Heart Association) Althingi (the Icelandic Parliament