Emergence of time-horizon invariant correlation structure in financial returns by subtraction of the market mode

We investigate the emergence of a structure in the correlation matrix of assets' returns as the time-horizon over which returns are computed increases from the minutes to the daily scale. We analyze data from different stock markets (New York, Paris, London, Milano) and with different methods. Result crucially depends on whether the data is restricted to the ``internal'' dynamics of the market, where the ``center of mass'' motion (the market mode) is removed or not. If the market mode is not removed, we find that the structure emerges, as the time-horizon increases, from splitting a single large cluster. In NYSE we find that when the market mode is removed, the structure of correlation at the daily scale is already well defined at the 5 minutes time-horizon, and this structure accounts for 80 % of the classification of stocks in economic sectors. Similar results, though less sharp, are found for the other markets. We also find that the structure of correlations in the overnight returns is markedly different from that of intraday activity.Comment: 12 pages, 17 figure

The SIDE dual VIS-NIR fiber fed spectrograph for the 10.4 m Gran Telescopio Canarias

SIDE (Super Ifu Deployable Experiment) is proposed as second-generation, common-user instrument for the GTC. It will be a low and intermediate resolution fiber fed spectrograph, highly efficient in multi-object and 3D spectroscopy. The low resolution part (R = 1500, 4000) is called Dual VIS-NIR because it will observe in the VIS and NIR bands (0.4 ~V 1.7 microns) simultaneously. Because of the large number of fibers, a set of ~10 identical spectrographs is needed, each with a mirror collimator, a dichroic and two refractive cameras. The cameras are optimized for 0.4 - 0.95 microns (VIS) and 0.95 - 1.7 microns (NIR) respectively.Comment: To appear in "Advanced Optical and Mechanical Technologies in Telescopes and Instrumentation" SPIE conference Proc. 7018, Marseille, 23-28 June 200

NICMOS Imaging of the Nuclei of Arp 220

We report high resolution imaging of the ultraluminous infrared galaxy Arp 220 at 1.1, 1.6, and 2.22 microns with NICMOS on the HST. The diffraction-limited images at 0.1--0.2 arcsecond resolution clearly resolve both nuclei of the merging galaxy system and reveal for the first time a number of luminous star clusters in the circumnuclear envelope. The morphologies of both nuclei are strongly affected by dust obscuration, even at 2.2 microns : the primary nucleus (west) presents a crescent shape, concave to the south and the secondary (eastern) nucleus is bifurcated by a dust lane with the southern component being very reddened. In the western nucleus, the morphology of the 2.2 micron emission is most likely the result of obscuration by an opaque disk embedded within the nuclear star cluster. The morphology of the central starburst-cluster in the western nucleus is consistent with either a circumnuclear ring of star formation or a spherical cluster with the bottom half obscured by the embedded dust disk. Comparison of cm-wave radio continuum maps with the near-infrared images suggests that the radio nuclei lie in the dust disk on the west and near the highly reddened southern component of the eastern complex. The radio nuclei are separated by 0.98 arcseconds (corresponding to 364 pc at 77 Mpc) and the half-widths of the infrared nuclei are approximately 0.2-0.5 arcseconds. At least 8, unresolved infrared sources -- probably globular clusters -- are also seen in the circumnuclear envelope at radii 2-7 arcseconds . Their near-infrared colors do not significantly constrain their ages.Comment: LaTex, 15 pages with 1 gif figure and 5 postscript figures. ApJL accepte

Using Water Chemistry Data to Assess Stormwater Pathways in Lowland Watersheds

2012 S.C. Water Resources Conference - Exploring Opportunities for Collaborative Water Research, Policy and Managemen

The Role of Landscape Connectivity in Planning and Implementing Conservation and Restoration Priorities. Issues in Ecology

Landscape connectivity, the extent to which a landscape facilitates the movements of organisms and their genes, faces critical threats from both fragmentation and habitat loss. Many conservation efforts focus on protecting and enhancing connectivity to offset the impacts of habitat loss and fragmentation on biodiversity conservation, and to increase the resilience of reserve networks to potential threats associated with climate change. Loss of connectivity can reduce the size and quality of available habitat, impede and disrupt movement (including dispersal) to new habitats, and affect seasonal migration patterns. These changes can lead, in turn, to detrimental effects for populations and species, including decreased carrying capacity, population declines, loss of genetic variation, and ultimately species extinction. Measuring and mapping connectivity is facilitated by a growing number of quantitative approaches that can integrate large amounts of information about organisms’ life histories, habitat quality, and other features essential to evaluating connectivity for a given population or species. However, identifying effective approaches for maintaining and restoring connectivity poses several challenges, and our understanding of how connectivity should be designed to mitigate the impacts of climate change is, as yet, in its infancy. Scientists and managers must confront and overcome several challenges inherent in evaluating and planning for connectivity, including: •characterizing the biology of focal species; •understanding the strengths and the limitations of the models used to evaluate connectivity; •considering spatial and temporal extent in connectivity planning; •using caution in extrapolating results outside of observed conditions; •considering non-linear relationships that can complicate assumed or expected ecological responses; •accounting and planning for anthropogenic change in the landscape; •using well-defined goals and objectives to drive the selection of methods used for evaluating and planning for connectivity; •and communicating to the general public in clear and meaningful language the importance of connectivity to improve awareness and strengthen policies for ensuring conservation. Several aspects of connectivity science deserve additional attention in order to improve the effectiveness of design and implementation. Research on species persistence, behavioral ecology, and community structure is needed to reduce the uncertainty associated with connectivity models. Evaluating and testing connectivity responses to climate change will be critical to achieving conservation goals in the face of the rapid changes that will confront many communities and ecosystems. All of these potential areas of advancement will fall short of conservation goals if we do not effectively incorporate human activities into connectivity planning. While this Issue identifies substantial uncertainties in mapping connectivity and evaluating resilience to climate change, it is also clear that integrating human and natural landscape conservation planning to enhance habitat connectivity is essential for biodiversity conservation

Investigating word affect features and fusion of probabilistic predictions incorporating uncertainty in AVEC 2017

© 2017 Association for Computing Machinery. Predicting emotion intensity and severity of depression are both challenging and important problems within the broader field of affective computing. As part of the AVEC 2017, we developed a number of systems to accomplish these tasks. In particular, word affect features, which derive human affect ratings (e.g. arousal and valence) from transcripts, were investigated for predicting depression severity and liking, showing great promise. A simple system based on the word affect features achieved an RMSE of 6.02 on the test set, yielding a relative improvement of 13.6% over the baseline. For the emotion prediction sub-challenge, we investigated multimodal fusion, which incorporated a measure of uncertainty associated with each prediction within an Output-Associative fusion framework for arousal and valence prediction, whilst liking prediction systems mainly focused on text-based features. Our best emotion prediction systems provided significant relative improvements over the baseline on the test set of 39.5%, 17.6%, and 29.3% for arousal, valence, and liking. Of particular note is that consistent improvements were observed when incorporating prediction uncertainty across various system configurations for predicting arousal and valence, suggesting the importance of taking into consideration prediction uncertainty for fusion and more broadly the advantages of probabilistic predictions

The Keck Low-Resolution Imaging Spectrometer

The Low Resolution Imaging Spectrometer (LRIS) for the Cassegrain focus of the Keck 10-m telescope on Mauna Kea is described. It has an imaging mode so it can also be used for taking direct images. The field of view in both spectrographic and imaging modes is 6 by 7.8 arcmin. It can be used with both conventional slits and custom-punched slit masks. The optical quality of the spectrograph is good enough to take full advantage of the excellent imaging properties of the telescope itself. The detector is a cooled back-illuminated Tektronics Inc. 2048 X 2048 CCD which gives a sampling rate of 4.685 pixels per arcsec. In the spectrographic mode the spectrograph has a maximum efficiency at the peak of the grating blaze of 32%-34% for the two lowest resolution gratings and 28% for the 1200 g mm^(-1) grating. This efficiency includes the detector but not the telescope or the atmosphere

ESI, a new Keck Observatory echellette spectrograph and imager

The Echellette Spectrograph and Imager (ESI) is a multipurpose instrument which has been delivered by the Instrument Development Laboratory of Lick Observatory for use at the Cassegrain focus of the Keck II telescope. ESI saw first light on August 29, 1999. ESI is a multi-mode instrument that enables the observer to seamlessly switch between three modes during an observation. The three modes of ESI are: An R=13,000-echellette mode; Low-dispersion prismatic mode; Direct imaging mode. ESI contains a unique flexure compensation system which reduces the small instrument flexure to negligible proportions. Long-exposure images on the sky show FWHM spot diameters of 34 microns (0.34") averaged over the entire field of view. These are the best non-AO images taken in the visible at Keck Observatory to date. Maximum efficiencies are measured to be 28% for the echellette mode and greater than 41% for low-dispersion prismatic mode including atmospheric, telescope and detector losses. In this paper we describe the instrument and its development. We also discuss the performance-testing and some observational results.Comment: 10 pages, 14 figures, 8tables, accepted for publication in PASP, 15 April 200

A peptide mimic of the chemotaxis inhibitory protein of Staphylococcus aureus: towards the development of novel anti-inflammatory compounds

Complement factor C5a is one of the most powerful pro-inflammatory agents involved in recruitment of leukocytes, activation of phagocytes and other inflammatory responses. C5a triggers inflammatory responses by binding to its G-protein-coupled C5a-receptor (C5aR). Excessive or erroneous activation of the C5aR has been implicated in numerous inflammatory diseases. The C5aR is therefore a key target in the development of specific anti-inflammatory compounds. A very potent natural inhibitor of the C5aR is the 121-residue chemotaxis inhibitory protein of Staphylococcus aureus (CHIPS). Although CHIPS effectively blocks C5aR activation by binding tightly to its extra-cellular N terminus, it is not suitable as a potential anti-inflammatory drug due to its immunogenic properties. As a first step in the development of an improved CHIPS mimic, we designed and synthesized a substantially shorter 50-residue adapted peptide, designated CHOPS. This peptide included all residues important for receptor binding as based on the recent structure of CHIPS in complex with the C5aR N terminus. Using isothermal titration calorimetry we demonstrate that CHOPS has micromolar affinity for a model peptide comprising residues 7–28 of the C5aR N terminus including two O-sulfated tyrosine residues at positions 11 and 14. CD and NMR spectroscopy showed that CHOPS is unstructured free in solution. Upon addition of the doubly sulfated model peptide, however, the NMR and CD spectra reveal the formation of structural elements in CHOPS reminiscent of native CHIPS