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Sample records for spitzer finds hidden

  1. Finding an apprenticeship: The hidden curriculum and its social consequences

    Directory of Open Access Journals (Sweden)

    Gaele eGoastellec

    2015-09-01

    Full Text Available In Switzerland, the majority of students are oriented towards professional training after compulsory schooling. At this stage, one of the biggest challenges for them is to find an apprenticeship position. Matching supply and demand is a complex process that not only excludes some students from having direct access to professional training but also forces them to make early choices regarding their future sector of employment. So, how does one find an apprenticeship? And what do the students’ descriptions of their search for apprenticeships reveal about the institutional determinants of social inequalities at play in the system?Based on 29 interviews conducted in 2014 with 23 apprentices and 6 recruiters in the Canton of Vaud, this article interrogates how the dimensions of educational and social trajectories combine to affect access to apprenticeships and are accentuated by recruiters using a hidden curriculum during the recruitment process. A hidden curriculum consists of knowledge and skills not taught by the educational institution but which appear decisive in obtaining an apprenticeship. By analysing the contrasting experiences of students in their search for an apprenticeship, we identify four types of trajectories that explain different types of school-to-apprenticeship transitions. We show how these determinants are reinforced by the hidden curriculum of recruitment based on the soft skills of feeling, autonomy, anticipation and reflexivity that are assessed in the context of recruitment interactions. The discussion section debates how the criteria that appear to be used to identify the right apprentice tend to (reproduce inequalities between students. This not only depends on their academic results but also on their social and cultural skills, their ability to anticipate their choices and, more widely, their ability to be a subject in their recruitment search. The Subject is neither the individual, nor the self, but the work through

  2. Finding Hidden Location Patterns of Two Competitive Supermarkets in Thailand

    Science.gov (United States)

    Khumsri, Jinattaporn; Fujihara, Akihiro

    There are two famous supermarkets in Thailand: Big C and Lotus. They are the highest competitive supermarkets whose hold the most market share by lots of promotions and also gather all convenience services including banking, restaurant, and others. In recent years, they gradually expand their stores and they take a similar strategy to determine where to locate a store. It is important for them to consider store allocation to obtain new customers efficiently. To consider this, we gather geographical locations of these supermarkets from Twitter using Twitter API. We gathered tweets having these supermarket names and geotags for seven months. To extract hidden location patterns from gathered data, we introduce location motif which is a directed subgraph whose edges are linked to every pair of the shortest-distance opponent node. We investigate every possible configuration of location motif when they have a small number of nodes and find that the configuration increases exponentially. We also visualize location motifs generated from gathered data on the map of Thailand and count the frequency of observed location motifs. As a result, we find that even if the possible location motifs exponentially increase as the number of nodes grows, limited location motifs can be observed. Using location motif, we successfully find an evidence of biased store allocation in reality.

  3. FINDING η CAR ANALOGS IN NEARBY GALAXIES USING SPITZER. I. CANDIDATE SELECTION

    International Nuclear Information System (INIS)

    Khan, Rubab; Stanek, K. Z.; Kochanek, C. S.

    2013-01-01

    The late-stage evolution of the most massive stars such as η Carinae is controlled by the effects of mass loss, which may be dominated by poorly understood eruptive mass ejections. Understanding this population is challenging because no true analogs of η Car have been clearly identified in the Milky Way or other galaxies. We utilize Spitzer IRAC images of seven nearby (∼ 10 5 L ☉ in the IRAC bands (3.6 to 8.0 μm) and are not known to be background sources. Based on our estimates for the expected number of background sources, we expect that follow-up observations will show that most of these candidates are not dust enshrouded massive stars, with an expectation of only 6 ± 6 surviving candidates. Since we would detect true analogs of η Car for roughly 200 years post-eruption, this implies that the rate of eruptions like η Car is less than the core-collapse supernova rate. It is possible, however, that every M > 40 M ☉ star undergoes such eruptions given our initial results. In Paper II we will characterize the candidates through further analysis and follow-up observations, and there is no barrier to increasing the galaxy sample by an order of magnitude. The primary limitation of the present search is that Spitzer's resolution limits us to the shorter wavelength IRAC bands. With the James Webb Space Telescope, such surveys can be carried out at the far more optimal wavelengths of 10-30 μm, allowing identification of η Car analogs for millennia rather than centuries post-eruption.

  4. The Query Complexity of Finding a Hidden Permutation

    DEFF Research Database (Denmark)

    Afshani, Peyman; Afrawal, Manindra; Benjamin, Doerr

    2012-01-01

    We study the query complexity of determining a hidden permutation. More specifically, we study the problem of learning a secret (z) consisting of a binary string z of length n and a permutation of [n]. The secret must be unveiled by asking queries x01n , and for each query asked, we are returned ...... applications in many other query complexity problems.......We study the query complexity of determining a hidden permutation. More specifically, we study the problem of learning a secret (z) consisting of a binary string z of length n and a permutation of [n]. The secret must be unveiled by asking queries x01n , and for each query asked, we are returned...... the score fz(x) defined as fz(x):=maxi[0n]ji:z(j)=x(j); i.e., the length of the longest common prefix of x and z with respect to . The goal is to minimize the number of queries asked. Our main result are matching upper and lower bounds for this problem, both for deterministic and randomized query schemes...

  5. Spitzer Spies Spectacular Sombrero

    Science.gov (United States)

    2005-01-01

    [figure removed for brevity, see original site] Figure 1 [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2 NASA's Spitzer Space Telescope set its infrared eyes on one of the most famous objects in the sky, Messier 104, also called the Sombrero galaxy. In this striking infrared picture, Spitzer sees an exciting new view of a galaxy that in visible light has been likened to a 'sombrero,' but here looks more like a 'bulls-eye.' Recent observations using Spitzer's infrared array camera uncovered the bright, smooth ring of dust circling the galaxy, seen in red. In visible light, because this galaxy is seen nearly edge-on, only the near rim of dust can be clearly seen in silhouette. Spitzer's full view shows the disk is warped, which is often the result of a gravitational encounter with another galaxy, and clumpy areas spotted in the far edges of the ring indicate young star-forming regions. Spitzer's infrared view of the starlight from this galaxy, seen in blue, can pierce through obscuring murky dust that dominates in visible light. As a result, the full extent of the bulge of stars and an otherwise hidden disk of stars within the dust ring are easily seen. The Sombrero galaxy is located some 28 million light years away. Viewed from Earth, it is just six degrees south of its equatorial plane. Spitzer detected infrared emission not only from the ring, but from the center of the galaxy too, where there is a huge black hole, believed to be a billion times more massive than our Sun. This picture is composed of four images taken at 3.6 (blue), 4.5 (green), 5.8 (orange), and 8.0 (red) microns. The contribution from starlight (measured at 3.6 microns) has been subtracted from the 5.8 and 8-micron images to enhance the visibility of the dust features. In figure 1, the new picture of Messier 104 combines a recent infrared observation from NASA's Spitzer Space Telescope with a well-known visible light image from the

  6. Gene finding with a hidden Markov model of genome structure and evolution

    DEFF Research Database (Denmark)

    Pedersen, Jakob Skou; Hein, Jotun

    2003-01-01

    the model are linear in alignment length and genome number. The model is applied to the problem of gene finding. The benefit of modelling sequence evolution is demonstrated both in a range of simulations and on a set of orthologous human/mouse gene pairs. AVAILABILITY: Free availability over the Internet...... annotation. The modelling of evolution by the existing comparative gene finders leaves room for improvement. Results: A probabilistic model of both genome structure and evolution is designed. This type of model is called an Evolutionary Hidden Markov Model (EHMM), being composed of an HMM and a set of region...

  7. Sneaking a peek: pigeons use peripheral vision (not mirrors) to find hidden food.

    Science.gov (United States)

    Ünver, Emre; Garland, Alexis; Tabrik, Sepideh; Güntürkün, Onur

    2017-07-01

    A small number of species are capable of recognizing themselves in the mirror when tested with the mark-and-mirror test. This ability is often seen as evidence of self-recognition and possibly even self-awareness. Strangely, a number of species, for example monkeys, pigs and dogs, are unable to pass the mark test but can locate rewarding objects by using the reflective properties of a mirror. Thus, these species seem to understand how a visual reflection functions but cannot apply it to their own image. We tested this discrepancy in pigeons-a species that does not spontaneously pass the mark test. Indeed, we discovered that pigeons can successfully find a hidden food reward using only the reflection, suggesting that pigeons can also use and potentially understand the reflective properties of mirrors, even in the absence of self-recognition. However, tested under monocular conditions, the pigeons approached and attempted to walk through the mirror rather than approach the physical food, displaying similar behavior to patients with mirror agnosia. These findings clearly show that pigeons do not use the reflection of mirrors to locate reward, but actually see the food peripherally with their near-panoramic vision. A re-evaluation of our current understanding of mirror-mediated behavior might be necessary-especially taking more fully into account species differences in visual field. This study suggests that use of reflections in a mirrored surface as a tool may be less widespread than currently thought.

  8. African elephants can use human pointing cues to find hidden food.

    Science.gov (United States)

    Smet, Anna F; Byrne, Richard W

    2013-10-21

    How animals gain information from attending to the behavior of others has been widely studied, driven partly by the importance of referential pointing in human cognitive development [1-4], but species differences in reading human social cues remain unexplained. One explanation is that this capacity evolved during domestication [5, 6], but it may be that only those animals able to interpret human-like social cues were successfully domesticated. Elephants are a critical taxon for this question: despite their longstanding use by humans, they have never been domesticated [7]. Here we show that a group of 11 captive African elephants, seven of them significantly as individuals, could interpret human pointing to find hidden food. We suggest that success was not due to prior training or extensive learning opportunities. Elephants successfully interpreted pointing when the experimenter's proximity to the hiding place was varied and when the ostensive pointing gesture was visually subtle, suggesting that they understood the experimenter's communicative intent. The elephant's native ability in interpreting social cues may have contributed to its long history of effective use by man. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. How to Find a Hidden World at the Large Hadron Collider

    CERN Document Server

    Wells, James D.

    2008-01-01

    I discuss how the Large Hadron Collider era should broaden our view of particle physics research, and apply this thinking to the case of Hidden Worlds. I focus on one of the simplest representative cases of a Hidden World, and detail the rich implications it has for LHC physics, including universal suppression of Higgs boson production, trans-TeV heavy Higgs boson signatures, heavy-to-light Higgs boson decays, weakly coupled exotic gauge bosons, and Higgs boson decays to four fermions via light exotic gauge bosons. Some signatures may be accessible in the very early stages of collider operation, whereas others motivate a later high-lumonosity upgrade.

  10. Spitzer Digs Up Galactic Fossil

    Science.gov (United States)

    2004-01-01

    [figure removed for brevity, see original site] Figure 1 [figure removed for brevity, see original site] Figure 2 This false-color image taken by NASA's Spitzer Space Telescope shows a globular cluster previously hidden in the dusty plane of our Milky Way galaxy. Globular clusters are compact bundles of old stars that date back to the birth of our galaxy, 13 or so billion years ago. Astronomers use these galactic 'fossils' as tools for studying the age and formation of the Milky Way. Most clusters orbit around the center of the galaxy well above its dust-enshrouded disc, or plane, while making brief, repeated passes through the plane that each last about a million years. Spitzer, with infrared eyes that can see into the dusty galactic plane, first spotted the newfound cluster during its current pass. A visible-light image (inset of Figure 1) shows only a dark patch of sky. The red streak behind the core of the cluster is a dust cloud, which may indicate the cluster's interaction with the Milky Way. Alternatively, this cloud may lie coincidentally along Spitzer's line of sight. Follow-up observations with the University of Wyoming Infrared Observatory helped set the distance of the new cluster at about 9,000 light-years from Earth - closer than most clusters - and set the mass at the equivalent of 300,000 Suns. The cluster's apparent size, as viewed from Earth, is comparable to a grain of rice held at arm's length. It is located in the constellation Aquila. Astronomers believe that this cluster may be one of the last in our galaxy to be uncovered. This image composite was taken on April 21, 2004, by Spitzer's infrared array camera. It is composed of images obtained at four wavelengths: 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange) and 8 microns (red). Galactic Fossil Found Behind Curtain of Dust In Figure 2, the image mosaic shows the same patch of sky in various wavelengths of light. While the visible-light image (left) shows a dark sky speckled

  11. Spitzer Telemetry Processing System

    Science.gov (United States)

    Stanboli, Alice; Martinez, Elmain M.; McAuley, James M.

    2013-01-01

    The Spitzer Telemetry Processing System (SirtfTlmProc) was designed to address objectives of JPL's Multi-mission Image Processing Lab (MIPL) in processing spacecraft telemetry and distributing the resulting data to the science community. To minimize costs and maximize operability, the software design focused on automated error recovery, performance, and information management. The system processes telemetry from the Spitzer spacecraft and delivers Level 0 products to the Spitzer Science Center. SirtfTlmProc is a unique system with automated error notification and recovery, with a real-time continuous service that can go quiescent after periods of inactivity. The software can process 2 GB of telemetry and deliver Level 0 science products to the end user in four hours. It provides analysis tools so the operator can manage the system and troubleshoot problems. It automates telemetry processing in order to reduce staffing costs.

  12. Exoplanet Characterization With Spitzer Eclipses

    Science.gov (United States)

    Harrington, Joseph

    attempts about 50 different analyses per observation, permuting different photometry aperture sizes, centering methods, and systematic models to find the best according to the standard deviation of normalized residuals and the Akaike and Bayesian Information Criteria. As a demonstration of its ease of use, two undergraduates have recently led papers based on the pipeline. The team now seeks funds for graduate student Patricio Cubillos, who is already trained and working (e.g., Cubillos et al. 2011). He will lead 1-2 secondary eclipse papers per year, based on our recent output. Three undergraduates will handle routine tasks and produce between them about one paper per year. The PI and a programmer are also supported. Our long-term goal is to produce a statistical sample of exoplanet secondary eclipses at wavelengths inaccessible to facilities other than Spitzer. These measure properties of exoplanetary atmospheres and orbits. Each planet is of significant intrinsic interest. In addition, an aggregate plot of planetary brightness vs. equilibrium temperature shows a significant jump in brightness near 2000 K. We will explore this and other results of aggregation, such as why some hot planets do or do not have thermal inversions, and under what circumstances photochemistry is important. There will be three main products from this grant: 1. Secondary eclipse analyses for 11 planets, including assessment of inversions, abundances, and thermal profiles. 2. Aggregate data analyses related to the brightness jump, which planets have thermal inversions and disequilibrium chemistry, and whether stellar metallicity, surface gravity, etc., affect the emitted fluxes. 3. Statistical enhancements to our open-source code for retrieving atmospheric composition and thermal profiles from eclipse data, using the method of Madhusudhan and Seager.

  13. Finding hidden periodic signals in time series - an application to stock prices

    Science.gov (United States)

    O'Shea, Michael

    2014-03-01

    Data in the form of time series appear in many areas of science. In cases where the periodicity is apparent and the only other contribution to the time series is stochastic in origin, the data can be `folded' to improve signal to noise and this has been done for light curves of variable stars with the folding resulting in a cleaner light curve signal. Stock index prices versus time are classic examples of time series. Repeating patterns have been claimed by many workers and include unusually large returns on small-cap stocks during the month of January, and small returns on the Dow Jones Industrial average (DJIA) in the months June through September compared to the rest of the year. Such observations imply that these prices have a periodic component. We investigate this for the DJIA. If such a component exists it is hidden in a large non-periodic variation and a large stochastic variation. We show how to extract this periodic component and for the first time reveal its yearly (averaged) shape. This periodic component leads directly to the `Sell in May and buy at Halloween' adage. We also drill down and show that this yearly variation emerges from approximately half of the underlying stocks making up the DJIA index.

  14. Spitzer - Hot & Colorful Student Activities

    Science.gov (United States)

    McDonald, D.; Rebull, L. M.; DeWolf, C.; Guastella, P.; Johnson, C. H.; Schaefers, J.; Spuck, T.; McDonald, J. G., III; DeWolf, T.; Brock, S.; Boerma, J.; Bemis, G.; Paulsen, K.; Yueh, N.; Peter, A.; Wassmer, W.; Haber, R.; Scaramucci, A.; Butchart, J.; Holcomb, A.; Karns, B.; Kennedy, S.; Siegel, R.; Weiser, S.

    2009-01-01

    In this poster, we present the results of several activities developed for the general science student to explore infrared light. The first activity involved measuring infrared radiation using an updated version of Newton's experiment of splitting white light and finding IR radiation. The second used Leslie's cube to allow students to observe different radiators, while the third used a modern infrared thermometer to measure and identify IR sources in an enclosed box. The last activity involved students making false-color images from narrow-band filter images from data sets from Spitzer Space Telescope, STScI Digitized Sky Survey and other sources. Using computer programs like Adobe Photoshop and free software such as ds9, Spot and Leopard, poster-like images were created by the students. This research is funded by the Spitzer Science Center (SSC) and the National Optical Astronomy Observatory (NOAO). Please see our companion poster, Johnson et al., on the science aspect of this program, and another poster on the educational aspects, Guastella et al.

  15. Finding cis-regulatory modules in Drosophila using phylogenetic hidden Markov models

    DEFF Research Database (Denmark)

    Wong, Wendy S W; Nielsen, Rasmus

    2007-01-01

    MOTIVATION: Finding the regulatory modules for transcription factors binding is an important step in elucidating the complex molecular mechanisms underlying regulation of gene expression. There are numerous methods available for solving this problem, however, very few of them take advantage of th...

  16. Gene finding with a hidden Markov model of genome structure and evolution

    DEFF Research Database (Denmark)

    Pedersen, Jakob Skou; Hein, Jotun

    2003-01-01

    the model are linear in alignment length and genome number. The model is applied to the problem of gene finding. The benefit of modelling sequence evolution is demonstrated both in a range of simulations and on a set of orthologous human/mouse gene pairs. AVAILABILITY: Free availability over the Internet...

  17. Scheduling Spitzer: The SIRPASS Story

    Science.gov (United States)

    Mittman, David S.; Hawkins, Robert

    2013-01-01

    NASA's Spitzer Space Telescope was launched on August 25, 2003 from Florida's Cape Canaveral Air Force Base. Drifting in a unique Earth-trailing orbit around the Sun, Spitzer sees an optically invisible universe dominated by dust and stars. Since 1997, the Spitzer Integrated Resource Planning and Scheduling System (SIRPASS) has helped produce spacecraft activity plans for the Spitzer Space Telescope. SIRPASS is used by members of the Observatory Planning and Scheduling Team to plan, schedule and sequence the Telescope from data made available to them from the science and engineering community. Because of the volume of data that needs to be scheduled, SIRPASS offers a variety of automated assistants to aid in this task. This paper will describe the functional elements of the SIRPASS software system -- emphasizing the role that automation plays in the system -- and will highlight lessons learned for the software developer from a decade of Spitzer Space Telescope operations experience.

  18. Dermoscopic findings in scalp psoriasis and seborrheic dermatitis; two new signs; signet ring vessel and hidden hair.

    Science.gov (United States)

    Kibar, Melike; Aktan, Şebnem; Bilgin, Muzaffer

    2015-01-01

    Psoriasis and seborrheic dermatitis are both chronic erythemato-squamous dermatoses that can involve the scalp. It may be difficult to differentiate these two diseases when there is isolated scalp involvement. Recently, trichoscopy is commonly used to differentiate noncicatricial alopecias including psoriasis and seborrheic dermatitis that can lead to telogen effluvium (TE). The objective of this study is to evaluate the trichoscopic figures that may help to differentiate scalp psoriasis and seborrheic dermatitis. Thirty one with scalp psoriasis and 112 patients with seborrheic dermatitis were enrolled. Trichoscopic examinations were performed using a videodermatoscope (MoleMax 3(®)). Trichoscopic findings of scalp psoriasis and seborrheic dermatitis were compared with each other, with 100 healthy individuals and with other noncicatricial alopecias including female androgenetic alopecia (FAGA) (n: 138), male androgenetic alopecia (n: 63), FAGA of male pattern (FAGA.M) (n: 5), alopecia areata (39), TE (n: 22) and trichotillomania (n: 4). Atypical red vessels, red dots and globules (RDG), signet ring vessels (SRV), structureless red areas and hidden hairs (HH) were statistically more common in psoriasis while twisted red loops and comma vessels (CV) in seborrheic dermatitis. RDG were considered as the characteristic videodermatoscopic figure for psoriasis and arborizing red lines and CV for seborrheic dermatitis. In comparison with previous reports, our study yielded two new trichoscopic structures supporting the diagnosis of psoriasis; HH and SRV. Besides, according to our study, CV were described for the first time in seborrheic dermatitis and considered to be specific for seborrheic dermatitis. This study confirmed that trichoscopy might be useful in differentiating scalp psoriasis and seborrheic dermatitis from each other and from other noncicatricial alopecia with three trichoscopic structures as HH, SRV and CV.

  19. Dermoscopic findings in scalp psoriasis and seborrheic dermatitis; Two new signs; Signet ring vessel and hidden hair

    Directory of Open Access Journals (Sweden)

    Melike Kibar

    2015-01-01

    Full Text Available Background: Psoriasis and seborrheic dermatitis are both chronic erythemato-squamous dermatoses that can involve the scalp. It may be difficult to differentiate these two diseases when there is isolated scalp involvement. Recently, trichoscopy is commonly used to differentiate noncicatricial alopecias including psoriasis and seborrheic dermatitis that can lead to telogen effluvium (TE. Objectives: The objective of this study is to evaluate the trichoscopic figures that may help to differentiate scalp psoriasis and seborrheic dermatitis. Materials and Methods: Thirty one with scalp psoriasis and 112 patients with seborrheic dermatitis were enrolled. Trichoscopic examinations were performed using a videodermatoscope (MoleMax 3 ® . Trichoscopic findings of scalp psoriasis and seborrheic dermatitis were compared with each other, with 100 healthy individuals and with other noncicatricial alopecias including female androgenetic alopecia (FAGA (n: 138, male androgenetic alopecia (n: 63, FAGA of male pattern (FAGA.M (n: 5, alopecia areata (39, TE (n: 22 and trichotillomania (n: 4. Results: Atypical red vessels, red dots and globules (RDG, signet ring vessels (SRV, structureless red areas and hidden hairs (HH were statistically more common in psoriasis while twisted red loops and comma vessels (CV in seborrheic dermatitis. RDG were considered as the characteristic videodermatoscopic figure for psoriasis and arborizing red lines and CV for seborrheic dermatitis. In comparison with previous reports, our study yielded two new trichoscopic structures supporting the diagnosis of psoriasis; HH and SRV. Besides, according to our study, CV were described for the first time in seborrheic dermatitis and considered to be specific for seborrheic dermatitis. Conclusion: This study confirmed that trichoscopy might be useful in differentiating scalp psoriasis and seborrheic dermatitis from each other and from other noncicatricial alopecia with three trichoscopic

  20. Visual cues given by humans are not sufficient for Asian elephants (Elephas maximus) to find hidden food.

    Science.gov (United States)

    Plotnik, Joshua M; Pokorny, Jennifer J; Keratimanochaya, Titiporn; Webb, Christine; Beronja, Hana F; Hennessy, Alice; Hill, James; Hill, Virginia J; Kiss, Rebecca; Maguire, Caitlin; Melville, Beckett L; Morrison, Violet M B; Seecoomar, Dannah; Singer, Benjamin; Ukehaxhaj, Jehona; Vlahakis, Sophia K; Ylli, Dora; Clayton, Nicola S; Roberts, John; Fure, Emilie L; Duchatelier, Alicia P; Getz, David

    2013-01-01

    Recent research suggests that domesticated species--due to artificial selection by humans for specific, preferred behavioral traits--are better than wild animals at responding to visual cues given by humans about the location of hidden food. \\Although this seems to be supported by studies on a range of domesticated (including dogs, goats and horses) and wild (including wolves and chimpanzees) animals, there is also evidence that exposure to humans positively influences the ability of both wild and domesticated animals to follow these same cues. Here, we test the performance of Asian elephants (Elephas maximus) on an object choice task that provides them with visual-only cues given by humans about the location of hidden food. Captive elephants are interesting candidates for investigating how both domestication and human exposure may impact cue-following as they represent a non-domesticated species with almost constant human interaction. As a group, the elephants (n = 7) in our study were unable to follow pointing, body orientation or a combination of both as honest signals of food location. They were, however, able to follow vocal commands with which they were already familiar in a novel context, suggesting the elephants are able to follow cues if they are sufficiently salient. Although the elephants' inability to follow the visual cues provides partial support for the domestication hypothesis, an alternative explanation is that elephants may rely more heavily on other sensory modalities, specifically olfaction and audition. Further research will be needed to rule out this alternative explanation.

  1. Visual cues given by humans are not sufficient for Asian elephants (Elephas maximus to find hidden food.

    Directory of Open Access Journals (Sweden)

    Joshua M Plotnik

    Full Text Available Recent research suggests that domesticated species--due to artificial selection by humans for specific, preferred behavioral traits--are better than wild animals at responding to visual cues given by humans about the location of hidden food. \\Although this seems to be supported by studies on a range of domesticated (including dogs, goats and horses and wild (including wolves and chimpanzees animals, there is also evidence that exposure to humans positively influences the ability of both wild and domesticated animals to follow these same cues. Here, we test the performance of Asian elephants (Elephas maximus on an object choice task that provides them with visual-only cues given by humans about the location of hidden food. Captive elephants are interesting candidates for investigating how both domestication and human exposure may impact cue-following as they represent a non-domesticated species with almost constant human interaction. As a group, the elephants (n = 7 in our study were unable to follow pointing, body orientation or a combination of both as honest signals of food location. They were, however, able to follow vocal commands with which they were already familiar in a novel context, suggesting the elephants are able to follow cues if they are sufficiently salient. Although the elephants' inability to follow the visual cues provides partial support for the domestication hypothesis, an alternative explanation is that elephants may rely more heavily on other sensory modalities, specifically olfaction and audition. Further research will be needed to rule out this alternative explanation.

  2. Spitzer Reveals Stellar 'Family Tree'

    Science.gov (United States)

    2008-01-01

    [figure removed for brevity, see original site] High resolution poster version Generations of stars can be seen in this new infrared portrait from NASA's Spitzer Space Telescope. In this wispy star-forming region, called W5, the oldest stars can be seen as blue dots in the centers of the two hollow cavities (other blue dots are background and foreground stars not associated with the region). Younger stars line the rims of the cavities, and some can be seen as pink dots at the tips of the elephant-trunk-like pillars. The white knotty areas are where the youngest stars are forming. Red shows heated dust that pervades the region's cavities, while green highlights dense clouds. W5 spans an area of sky equivalent to four full moons and is about 6,500 light-years away in the constellation Cassiopeia. The Spitzer picture was taken over a period of 24 hours. Like other massive star-forming regions, such as Orion and Carina, W5 contains large cavities that were carved out by radiation and winds from the region's most massive stars. According to the theory of triggered star-formation, the carving out of these cavities pushes gas together, causing it to ignite into successive generations of new stars. This image contains some of the best evidence yet for the triggered star-formation theory. Scientists analyzing the photo have been able to show that the ages of the stars become progressively and systematically younger with distance from the center of the cavities. This is a three-color composite showing infrared observations from two Spitzer instruments. Blue represents 3.6-micron light and green shows light of 8 microns, both captured by Spitzer's infrared array camera. Red is 24-micron light detected by Spitzer's multiband imaging photometer.

  3. Hidden charged dark matter

    International Nuclear Information System (INIS)

    Feng, Jonathan L.; Kaplinghat, Manoj; Tu, Huitzu; Yu, Hai-Bo

    2009-01-01

    Can dark matter be stabilized by charge conservation, just as the electron is in the standard model? We examine the possibility that dark matter is hidden, that is, neutral under all standard model gauge interactions, but charged under an exact (\\rm U)(1) gauge symmetry of the hidden sector. Such candidates are predicted in WIMPless models, supersymmetric models in which hidden dark matter has the desired thermal relic density for a wide range of masses. Hidden charged dark matter has many novel properties not shared by neutral dark matter: (1) bound state formation and Sommerfeld-enhanced annihilation after chemical freeze out may reduce its relic density, (2) similar effects greatly enhance dark matter annihilation in protohalos at redshifts of z ∼ 30, (3) Compton scattering off hidden photons delays kinetic decoupling, suppressing small scale structure, and (4) Rutherford scattering makes such dark matter self-interacting and collisional, potentially impacting properties of the Bullet Cluster and the observed morphology of galactic halos. We analyze all of these effects in a WIMPless model in which the hidden sector is a simplified version of the minimal supersymmetric standard model and the dark matter is a hidden sector stau. We find that charged hidden dark matter is viable and consistent with the correct relic density for reasonable model parameters and dark matter masses in the range 1 GeV ∼ X ∼< 10 TeV. At the same time, in the preferred range of parameters, this model predicts cores in the dark matter halos of small galaxies and other halo properties that may be within the reach of future observations. These models therefore provide a viable and well-motivated framework for collisional dark matter with Sommerfeld enhancement, with novel implications for astrophysics and dark matter searches

  4. Spitzer Science Center within an Enterprise Architecture

    Science.gov (United States)

    Handley, T.

    2007-10-01

    The Spitzer Science Center's (SSC) evolutionary development approach, coupled with a flexible, scaleable hardware and software architecture has been key in Spitzer's ability to handle an explosion of data products, evolving data definitions, and changing data quality requirements. Spitzer is generating (depending on the campaign and instrument) about 10 TB of pre-archive data every 14 to 20 days. This generally reduces to between 3 TB and 6 TB of standard products, again depending on the campaign and instrument. This paper will discuss (1) the Spitzer Science Center's responses to evolving data, quality, and processing requirements and (2) how robust or not was the original architecture to allow Spitzer to accommodate on-going change.

  5. Hunting Elusive SPRITEs with Spitzer

    Science.gov (United States)

    Kohler, Susanna

    2017-05-01

    In recent years, astronomers have developed many wide-field imaging surveys in which the same targets are observed again and again. This new form of observing has allowed us to discover optical and radio transients explosive or irregular events with durations ranging from seconds to years. The dynamic infrared sky, however, has remained largely unexplored until now.Infrared ExplorationExample of a transient: SPIRITS 14ajc was visible when imaged by SPIRITS in 2014 (left) but it wasnt there during previous imaging between 2004 and 2008 (right). The bottom frame shows the difference between the two images. [Adapted from Kasliwal et al. 2017]Why hunt for infrared transients? Optical wavelengths dont allow us to observe events that are obscured, such that their own structure or their surroundings hide them from our view. Both supernovae and luminous red novae (associated with stellar mergers) are discoverable as infrared transients, and there may well be new types of transients in infrared that we havent seen before!To explore this uncharted territory, a team of scientists developed SPIRITS, the Spitzer Infrared Intensive Transients Survey. Begun in 2014, SPIRITS is a five-year long survey that uses the Spitzer Space Telescope to conduct a systematic search for mid-infrared transients in nearby galaxies.In a recent publication led by Mansi Kasliwal (Caltech and the Carnegie Institution for Science), the SPIRITS team has now detailed how their survey works and what theyve discovered in its first year.The light curves of SPRITEs (red stars) lie in the mid-infared luminosity gap between novae (orange) and supernovae (blue). [Kasliwal et al. 2017]Mystery TransientsKasliwal and collaborators used Spitzer to monitor 190 nearby galaxies. In SPIRITS first year, they found over 1958 variable stars and 43 infrared transient sources. Of these 43 transients, 21 were known supernovae, 4 were in the luminosity range of novae, and 4 had optical counterparts. The remaining 14 events

  6. Early 2017 observations of TRAPPIST-1 with Spitzer

    Science.gov (United States)

    Delrez, L.; Gillon, M.; Triaud, A. H. M. J.; Demory, B.-O.; de Wit, J.; Ingalls, J. G.; Agol, E.; Bolmont, E.; Burdanov, A.; Burgasser, A. J.; Carey, S. J.; Jehin, E.; Leconte, J.; Lederer, S.; Queloz, D.; Selsis, F.; Van Grootel, V.

    2018-04-01

    The recently detected TRAPPIST-1 planetary system, with its seven planets transiting a nearby ultracool dwarf star, offers the first opportunity to perform comparative exoplanetology of temperate Earth-sized worlds. To further advance our understanding of these planets' compositions, energy budgets, and dynamics, we are carrying out an intensive photometric monitoring campaign of their transits with the Spitzer Space Telescope. In this context, we present 60 new transits of the TRAPPIST-1 planets observed with Spitzer/Infrared Array Camera (IRAC) in 2017 February and March. We combine these observations with previously published Spitzer transit photometry and perform a global analysis of the resulting extensive data set. This analysis refines the transit parameters and provides revised values for the planets' physical parameters, notably their radii, using updated properties for the star. As part of our study, we also measure precise transit timings that will be used in a companion paper to refine the planets' masses and compositions using the transit timing variations method. TRAPPIST-1 shows a very low level of low-frequency variability in the IRAC 4.5-μm band, with a photometric RMS of only 0.11 per cent at a 123-s cadence. We do not detect any evidence of a (quasi-)periodic signal related to stellar rotation. We also analyse the transit light curves individually, to search for possible variations in the transit parameters of each planet due to stellar variability, and find that the Spitzer transits of the planets are mostly immune to the effects of stellar variations. These results are encouraging for forthcoming transmission spectroscopy observations of the TRAPPIST-1 planets with the James Webb Space Telescope.

  7. The Hidden Costs of Offshoring

    DEFF Research Database (Denmark)

    Møller Larsen, Marcus; Manning, Stephan; Pedersen, Torben

    2011-01-01

    experience moderate the relationship between complexity and hidden costs negatively i.e. reduces the cost generating impact of complexity. We develop three hypotheses and test them on comprehensive data from the Offshoring Research Network (ORN). In general, we find support for our hypotheses. A key result......This study seeks to explain hidden costs of offshoring, i.e. unexpected costs resulting from the relocation of business tasks and activities outside the home country. We develop a model that highlights the role of complexity, design orientation and experience in explaining hidden costs...

  8. Does immigrant residential crowding reflect hidden homelessness?

    Directory of Open Access Journals (Sweden)

    Michael Haan

    2011-12-01

    the extent to which heightened levels of residential crowding might reflect “hidden homelessness.” I find mixed evidence to support this link, and, if anything, find some evidence to suggest that the link between residential crowding and hidden homelessness, if one exists, is strongest for the Canadian-born.

  9. SPITZER OBSERVATIONS OF YOUNG RED QUASARS

    International Nuclear Information System (INIS)

    Urrutia, Tanya; Lacy, Mark; Spoon, Henrik; Glikman, Eilat; Petric, Andreea; Schulz, Bernhard

    2012-01-01

    We present mid-infrared spectra and photometry of 13 redshift 0.4 < z < 1 dust reddened quasars obtained with Spitzer IRS and MIPS. We compare properties derived from their infrared spectral energy distributions (intrinsic active galactic nucleus (AGN) luminosity and far-infrared luminosity from star formation) to the host luminosities and morphologies from Hubble Space Telescope imaging, and black hole masses estimated from optical and/or near-infrared spectroscopy. Our results are broadly consistent with models in which most dust reddened quasars are an intermediate phase between a merger-driven starburst triggering a completely obscured AGN, and a normal, unreddened quasar. We find that many of our objects have high accretion rates, close to the Eddington limit. These objects tend to fall below the black hole mass-bulge luminosity relation as defined by local galaxies, whereas most of our low accretion rate objects are slightly above the local relation, as typical for normal quasars at these redshifts. Our observations are therefore most readily interpreted in a scenario in which galaxy stellar mass growth occurs first by about a factor of three in each merger/starburst event, followed sometime later by black hole growth by a similar amount. We do not, however, see any direct evidence for quasar feedback affecting star formation in our objects, for example, in the form of a relationship between accretion rate and star formation. Five of our objects, however, do show evidence for outflows in the [O III]5007 Å emission line profile, suggesting that the quasar activity is driving thermal winds in at least some members of our sample.

  10. Lyman Spitzer: Life, Times, and Science

    Indian Academy of Sciences (India)

    Lyman Spitzer was one of the major figures of twentieth centurytheoretical astrophysics. Over more than fifty years,he kept up sustained research of his own, on problems concerningthe interstellar medium, star formation, and galaxies.In addition he was a major influence on observationalprogrammes, and created a thriving ...

  11. Spitzer Parallax of OGLE-2015-BLG-0966

    DEFF Research Database (Denmark)

    Street, R. A.; Udalski, A.; Calchi Novati, S.

    2016-01-01

    We report the detection of a cold Neptune mplanet = 21 ± 2 M⊕ orbiting a 0.38 M⊙ M dwarf lying 2.5-3.3 kpc toward the Galactic center as part of a campaign combining ground-based and Spitzer observations to measure the Galactic distribution of planets. This is the first time that the complex real...

  12. Lyman Spitzer: Life, Times, and Science

    Indian Academy of Sciences (India)

    College, Cambridge, in the academic year 1935–36. It was com- mon in those days for promising students from the United States to spend some time in England or Europe – the precise opposite of the situation today! Cambridge exposed Spitzer to the most distinguished astrophysi- cist of that time – Arthur Eddington.

  13. Hidden Heroes

    Science.gov (United States)

    Ramchand, Rajeev; Tanielian, Terri; Fisher, Michael P.; Vaughan, Christine Anne; Trail, Thomas E.; Epley, Caroline; Voorhies, Phoenix; Robbins, Michael; Robinson, Eric; Ghosh-Dastidar, Bonnie

    2014-01-01

    Abstract While much has been written about the role of caregiving for the elderly and chronically ill and for children with special needs, little is known about “military caregivers”—the population of those who care for wounded, ill, and injured military personnel and veterans. These caregivers play an essential role in caring for injured or wounded service members and veterans. This enables those for whom they are caring to live better quality lives, and can result in faster and improved rehabilitation and recovery. Yet playing this role can impose a substantial physical, emotional, and financial toll on caregivers. This article distills a longer report, Hidden Heroes: America's Military Caregivers, which describes the results of a study designed to describe the magnitude of military caregiving in the United States today, as well as to identify gaps in the array of programs, policies, and initiatives designed to support military caregivers. Improving military caregivers' well-being and ensuring their continued ability to provide care will require multifaceted approaches to reducing the current burdens caregiving may impose, and bolstering their ability to serve as caregivers more effectively. Given the systematic differences among military caregiver groups, it is also important that tailored approaches meet the unique needs and characteristics of post-9/11 caregivers. PMID:28083343

  14. Probing hidden sector photons through the Higgs window

    Energy Technology Data Exchange (ETDEWEB)

    Ahlers, M. [Oxford Univ. (United Kingdom). Rudolf Peierls Centre for Theoretical Physics; Jaeckel, J. [Durham Univ. (United Kingdom). Inst. for Particle Physics and Phenomenology; Redondo, J.; Ringwald, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2008-07-15

    We investigate the possibility that a (light) hidden sector extra photon receives its mass via spontaneous symmetry breaking of a hidden sector Higgs boson, the so-called hidden-Higgs. The hidden-photon can mix with the ordinary photon via a gauge kinetic mixing term. The hidden-Higgs can couple to the Standard Model Higgs via a renormalizable quartic term - sometimes called the Higgs Portal. We discuss the implications of this light hidden-Higgs in the context of laser polarization and light-shining-through-the-wall experiments as well as cosmological, astrophysical, and non-Newtonian force measurements. For hidden-photons receiving their mass from a hidden-Higgs we find in the small mass regime significantly stronger bounds than the bounds on massive hidden sector photons alone. (orig.)

  15. Hidden loss

    DEFF Research Database (Denmark)

    Kieffer-Kristensen, Rikke; Johansen, Karen Lise Gaardsvig

    2013-01-01

    finding indicates that the children experienced numerous losses, many of which were often suppressed or neglected by the children to protect the ill parents. CONCLUSIONS: The findings indicated that the children seemed to make a special effort to hide their feelings of loss and grief in order to protect...... the ill parent. These findings contribute to a deeper understanding of the traumatic process of parental ABI that some children experience and emphasize the importance of family-centred interventions that include the children....

  16. Spitzer secondary eclipses of Qatar-1b

    Science.gov (United States)

    Garhart, Emily; Deming, Drake; Mandell, Avi; Knutson, Heather; Fortney, Jonathan J.

    2018-02-01

    Aims: Previous secondary eclipse observations of the hot Jupiter Qatar-1b in the Ks band suggest that it may have an unusually high day side temperature, indicative of minimal heat redistribution. There have also been indications that the orbit may be slightly eccentric, possibly forced by another planet in the system. We investigate the day side temperature and orbital eccentricity using secondary eclipse observations with Spitzer. Methods: We observed the secondary eclipse with Spitzer/IRAC in subarray mode, in both 3.6 and 4.5 μm wavelengths. We used pixel-level decorrelation to correct for Spitzer's intra-pixel sensitivity variations and thereby obtain accurate eclipse depths and central phases. Results: Our 3.6 μm eclipse depth is 0.149 ± 0.051% and the 4.5 μm depth is 0.273 ± 0.049%. Fitting a blackbody planet to our data and two recent Ks band eclipse depths indicates a brightness temperature of 1506 ± 71 K. Comparison to model atmospheres for the planet indicates that its degree of longitudinal heat redistribution is intermediate between fully uniform and day-side only. The day side temperature of the planet is unlikely to be as high (1885 K) as indicated by the ground-based eclipses in the Ks band, unless the planet's emergent spectrum deviates strongly from model atmosphere predictions. The average central phase for our Spitzer eclipses is 0.4984 ± 0.0017, yielding e cos ω = -0.0028 ± 0.0027. Our results are consistent with a circular orbit, and we constrain e cos ω much more strongly than has been possible with previous observations. Tables of the lightcurve data are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/610/A55

  17. Efficient Mosaicking of Spitzer Space Telescope Images

    Science.gov (United States)

    Jacob, Joseph; Makovoz, David; Eisenhardt, Peter

    2007-01-01

    A parallel version of the MOPEX software, which generates mosaics of infrared astronomical images acquired by the Spitzer Space Telescope, extends the capabilities of the prior serial version. In the parallel version, both the input image space and the output mosaic space are divided among the available parallel processors. This is the only software that performs the point-source detection and the rejection of spurious imaging effects of cosmic rays required by Spitzer scientists. This software includes components that implement outlier-detection algorithms that can be fine-tuned for a particular set of image data by use of a number of adjustable parameters. This software has been used to construct a mosaic of the Spitzer Infrared Array Camera Shallow Survey, which comprises more than 17,000 exposures in four wavelength bands from 3.6 to 8 m and spans a solid angle of about 9 square degrees. When this software was executed on 32 nodes of the 1,024-processor Cosmos cluster computer at NASA s Jet Propulsion Laboratory, a speedup of 8.3 was achieved over the serial version of MOPEX. The performance is expected to improve dramatically once a true parallel file system is installed on Cosmos.

  18. Detecting hidden particles with MATHUSLA

    Science.gov (United States)

    Evans, Jared A.

    2018-03-01

    A hidden sector containing light long-lived particles provides a well-motivated place to find new physics. The recently proposed MATHUSLA experiment has the potential to be extremely sensitive to light particles originating from rare meson decays in the very long lifetime region. In this work, we illustrate this strength with the specific example of a light scalar mixed with the standard model-like Higgs boson, a model where MATHUSLA can further probe unexplored parameter space from exotic Higgs decays. Design augmentations should be considered in order to maximize the ability of MATHUSLA to discover very light hidden sector particles.

  19. SPIRITS: Uncovering Unusual Infrared Transients with Spitzer

    Energy Technology Data Exchange (ETDEWEB)

    Kasliwal, Mansi M.; Jencson, Jacob E.; Tinyanont, Samaporn; Cao, Yi; Cook, David [Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Bally, John [Center for Astrophysics and Space Astronomy, University of Colorado, 389 UCB, Boulder, CO 80309 (United States); Masci, Frank; Armus, Lee [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Cody, Ann Marie [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Bond, Howard E. [Dept. of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Contreras, Carlos [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Dykhoff, Devin A.; Amodeo, Samuel; Carlon, Robert L.; Cass, Alexander C.; Corgan, David T.; Faella, Joseph [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street, S. E., University of Minnesota, Minneapolis, MN 55455 (United States); Boyer, Martha [NASA Goddard Space Flight Center, MC 665, 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Cantiello, Matteo [Center for Computational Astrophysics, Flatiron Institute, 162 Fifth Avenue, New York, NY 10010 (United States); Fox, Ori D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); and others

    2017-04-20

    We present an ongoing, five-year systematic search for extragalactic infrared transients, dubbed SPIRITS—SPitzer InfraRed Intensive Transients Survey. In the first year, using Spitzer /IRAC, we searched 190 nearby galaxies with cadence baselines of one month and six months. We discovered over 1958 variables and 43 transients. Here, we describe the survey design and highlight 14 unusual infrared transients with no optical counterparts to deep limits, which we refer to as SPRITEs (eSPecially Red Intermediate-luminosity Transient Events). SPRITEs are in the infrared luminosity gap between novae and supernovae, with [4.5] absolute magnitudes between −11 and −14 (Vega-mag) and [3.6]–[4.5] colors between 0.3 mag and 1.6 mag. The photometric evolution of SPRITEs is diverse, ranging from <0.1 mag yr{sup −1} to >7 mag yr{sup −1}. SPRITEs occur in star-forming galaxies. We present an in-depth study of one of them, SPIRITS 14ajc in Messier 83, which shows shock-excited molecular hydrogen emission. This shock may have been triggered by the dynamic decay of a non-hierarchical system of massive stars that led to either the formation of a binary or a protostellar merger.

  20. SPITZER SECONDARY ECLIPSES OF WASP-18b

    International Nuclear Information System (INIS)

    Nymeyer, Sarah; Harrington, Joseph; Hardy, Ryan A.; Stevenson, Kevin B.; Campo, Christopher J.; Blecic, Jasmina; Bowman, William C.; Britt, Christopher B. T.; Cubillos, Patricio; Madhusudhan, Nikku; Collier-Cameron, Andrew; Maxted, Pierre F. L.; Loredo, Thomas J.; Hellier, Coel; Anderson, David R.; Gillon, Michael; Hebb, Leslie; Wheatley, Peter J.; Pollacco, Don

    2011-01-01

    The transiting exoplanet WASP-18b was discovered in 2008 by the Wide Angle Search for Planets project. The Spitzer Exoplanet Target of Opportunity Program observed secondary eclipses of WASP-18b using Spitzer's Infrared Array Camera in the 3.6 μm and 5.8 μm bands on 2008 December 20, and in the 4.5 μm and 8.0 μm bands on 2008 December 24. We report eclipse depths of 0.30% ± 0.02%, 0.39% ± 0.02%, 0.37% ± 0.03%, 0.41% ± 0.02%, and brightness temperatures of 3100 ± 90, 3310 ± 130, 3080 ± 140, and 3120 ± 110 K in order of increasing wavelength. WASP-18b is one of the hottest planets yet discovered—as hot as an M-class star. The planet's pressure-temperature profile most likely features a thermal inversion. The observations also require WASP-18b to have near-zero albedo and almost no redistribution of energy from the day side to the night side of the planet.

  1. Spitzer Photometry of WISE-selected Brown Dwarf and Hyper-luminous Infrared Galaxy Candidates

    Science.gov (United States)

    Griffith, Roger L.; Kirkpatrick, J. Davy; Eisenhardt, Peter R. M.; Gelino, Christopher R.; Cushing, Michael C.; Benford, Dominic; Blain, Andrew; Bridge, Carrie R.; Cohen, Martin; Cutri, Roc M.; Donoso, Emilio; Jarrett, Thomas H.; Lonsdale, Carol; Mace, Gregory; Mainzer, A.; Marsh, Ken; Padgett, Deborah; Petty, Sara; Ressler, Michael E.; Skrutskie, Michael F.; Stanford, Spencer A.; Stern, Daniel; Tsai, Chao-Wei; Wright, Edward L.; Wu, Jingwen; Yan, Lin

    2012-11-01

    We present Spitzer 3.6 and 4.5 μm photometry and positions for a sample of 1510 brown dwarf candidates identified by the Wide-field Infrared Survey Explorer (WISE) all-sky survey. Of these, 166 have been spectroscopically classified as objects with spectral types M(1), L(7), T(146), and Y(12). Sixteen other objects are non-(sub)stellar in nature. The remainder are most likely distant L and T dwarfs lacking spectroscopic verification, other Y dwarf candidates still awaiting follow-up, and assorted other objects whose Spitzer photometry reveals them to be background sources. We present a catalog of Spitzer photometry for all astrophysical sources identified in these fields and use this catalog to identify seven fainter (4.5 μm ~ 17.0 mag) brown dwarf candidates, which are possibly wide-field companions to the original WISE sources. To test this hypothesis, we use a sample of 919 Spitzer observations around WISE-selected high-redshift hyper-luminous infrared galaxy candidates. For this control sample, we find another six brown dwarf candidates, suggesting that the seven companion candidates are not physically associated. In fact, only one of these seven Spitzer brown dwarf candidates has a photometric distance estimate consistent with being a companion to the WISE brown dwarf candidate. Other than this, there is no evidence for any widely separated (>20 AU) ultra-cool binaries. As an adjunct to this paper, we make available a source catalog of ~7.33 × 105 objects detected in all of these Spitzer follow-up fields for use by the astronomical community. The complete catalog includes the Spitzer 3.6 and 4.5 μm photometry, along with positionally matched B and R photometry from USNO-B; J, H, and Ks photometry from Two Micron All-Sky Survey; and W1, W2, W3, and W4 photometry from the WISE all-sky catalog.

  2. Spitzer Photometry of WISE-Selected Brown Dwarf and Hyper-Lumninous Infrared Galaxy Candidates

    Science.gov (United States)

    Griffith, Roger L.; Kirkpatrick, J. Davy; Eisenhardt, Peter R. M.; Gelino, Christopher R.; Cushing, Michael C.; Benford, Dominic; Blain, Andrew; Bridge, Carrie R.; Cohen, Martin; Cutri, Roc M.; hide

    2012-01-01

    We present Spitzer 3.6 and 4.5 micrometer photometry and positions for a sample of 1510 brown dwarf candidates identified by the Wide-field Infrared Survey Explorer (WISE) all-sky survey. Of these, 166 have been spectroscopically classified as objects with spectral types M(1), L(7), T(146), and Y(12). Sixteen other objects are non-(sub)stellar in nature. The remainder are most likely distant L and T dwarfs lacking spectroscopic verification, other Y dwarf candidates still awaiting follow-up, and assorted other objects whose Spitzer photometry reveals them to be background sources. We present a catalog of Spitzer photometry for all astrophysical sources identified in these fields and use this catalog to identify seven fainter (4.5 m to approximately 17.0 mag) brown dwarf candidates, which are possibly wide-field companions to the original WISE sources. To test this hypothesis, we use a sample of 919 Spitzer observations around WISE-selected high-redshift hyper-luminous infrared galaxy candidates. For this control sample, we find another six brown dwarf candidates, suggesting that the seven companion candidates are not physically associated. In fact, only one of these seven Spitzer brown dwarf candidates has a photometric distance estimate consistent with being a companion to the WISE brown dwarf candidate. Other than this, there is no evidence for any widely separated (greater than 20 AU) ultra-cool binaries. As an adjunct to this paper, we make available a source catalog of 7.33 x 10(exp 5) objects detected in all of these Spitzer follow-up fields for use by the astronomical community. The complete catalog includes the Spitzer 3.6 and 4.5 m photometry, along with positionally matched B and R photometry from USNO-B; J, H, and Ks photometry from Two Micron All-Sky Survey; and W1, W2, W3, and W4 photometry from the WISE all-sky catalog.

  3. Partially Hidden Markov Models

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Rissanen, Jorma

    1996-01-01

    Partially Hidden Markov Models (PHMM) are introduced. They differ from the ordinary HMM's in that both the transition probabilities of the hidden states and the output probabilities are conditioned on past observations. As an illustration they are applied to black and white image compression where...

  4. Petro Rents, Political Institutions, and Hidden Wealth

    DEFF Research Database (Denmark)

    Andersen, Jørgen Juel; Johannesen, Niels; Lassen, David Dreyer

    2017-01-01

    Do political institutions limit rent seeking by politicians? We study the transformation of petroleum rents, almost universally under direct government control, into hidden wealth using unique data on bank deposits in offshore financial centers that specialize in secrecy and asset protection. Our...... rulers is diverted to secret accounts. We find very limited evidence that shocks to other types of income not directly controlled by governments affect hidden wealth....

  5. OPEN CLUSTERS IN THE MILKY WAY OUTER DISK: NEWLY DISCOVERED AND UNSTUDIED CLUSTERS IN THE SPITZER GLIMPSE-360, CYG-X, AND SMOG SURVEYS

    International Nuclear Information System (INIS)

    Zasowski, G.; Beaton, R. L.; Hamm, K. K.; Majewski, S. R.; Patterson, R. J.; Babler, B.; Churchwell, E.; Meade, M.; Whitney, B. A.; Benjamin, R. A.; Watson, C.

    2013-01-01

    Open stellar clusters are extremely valuable probes of Galactic structure, star formation, kinematics, and chemical abundance patterns. Near-infrared (NIR) data have enabled the detection of hundreds of clusters hidden from optical surveys, and mid-infrared (MIR) data are poised to offer an even clearer view into the most heavily obscured parts of the Milky Way. We use new MIR images from the Spitzer GLIMPSE-360, Cyg-X, and SMOG surveys to visually identify a large number of open cluster candidates in the outer disk of the Milky Way (65° < l < 265°). Using NIR color-magnitude diagrams, stellar isochrones, and stellar reddening estimates, we derive cluster parameters (metallicity, distance, reddening) for those objects without previous identification and/or parameters in the literature. In total, we present coordinates and sizes of 20 previously unknown open cluster candidates; for 7 of these we also present metallicity, distance, and reddening values. In addition, we provide the first estimates of these values for nine clusters that had been previously cataloged. We compare our cluster sizes and other derived parameters to those in the open cluster catalog of Dias et al. and find strong similarities except for a higher mean reddening for our objects, which signifies our increased detection sensitivity in regions of high extinction. The results of this cluster search and analysis demonstrate the ability of MIR imaging and photometry to augment significantly the current census of open clusters in the Galaxy

  6. The impact of endorsing Spitzer's proposed criteria for PTSD in the forthcoming DSM-V on male and female Veterans.

    Science.gov (United States)

    Miller, Lyndsey N; Chard, Kathleen M; Schumm, Jeremiah A; O'Brien, Carol

    2011-06-01

    This study explored differences between Spitzer's proposed model of posttraumatic stress disorder (PTSD) and the current DSM-IV diagnostic classification scheme in 353 Veterans. The majority of Veterans (89%) diagnosed with PTSD as specified in the DSM-IV also met Spitzer's proposed criteria. Veterans who met both DSM-IV and Spitzer's proposed criteria had significantly higher Clinician Administered PTSD Scale severity scores than Veterans only meeting DSM-IV criteria. Logistic regression indicated that being African American and having no comorbid diagnosis of major depressive disorder or history of a substance use disorder were found to predict those Veterans who met current, but not proposed criteria. These findings have important implications regarding proposed changes to the diagnostic classification criteria for PTSD in the forthcoming DSM-V. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. The impact of Spitzer infrared data on stellar mass estimates - and a revised galaxy stellar mass function at 0 < z < 5

    Science.gov (United States)

    Elsner, F.; Feulner, G.; Hopp, U.

    2008-01-01

    Aims:We estimate stellar masses of galaxies in the high redshift universe with the intention of determining the influence of newly available Spitzer/IRAC infrared data on the analysis. Based on the results, we probe the mass assembly history of the universe. Methods: We use the GOODS-MUSIC catalog, which provides multiband photometry from the U-filter to the 8 μm Spitzer band for almost 15 000 galaxies with either spectroscopic (for ≈7% of the sample) or photometric redshifts, and apply a standard model fitting technique to estimate stellar masses. We than repeat our calculations with fixed photometric redshifts excluding Spitzer photometry and directly compare the outcomes to look for systematic deviations. Finally we use our results to compute stellar mass functions and mass densities up to redshift z = 5. Results: We find that stellar masses tend to be overestimated on average if further constraining Spitzer data are not included into the analysis. Whilst this trend is small up to intermediate redshifts z ⪉ 2.5 and falls within the typical error in mass, the deviation increases strongly for higher redshifts and reaches a maximum of a factor of three at redshift z ≈ 3.5. Thus, up to intermediate redshifts, results for stellar mass density are in good agreement with values taken from literature calculated without additional Spitzer photometry. At higher redshifts, however, we find a systematic trend towards lower mass densities if Spitzer/IRAC data are included.

  8. MEASURING ORGANIC MOLECULAR EMISSION IN DISKS WITH LOW-RESOLUTION SPITZER SPECTROSCOPY

    International Nuclear Information System (INIS)

    Teske, Johanna K.; Najita, Joan R.; Carr, John S.; Pascucci, Ilaria; Apai, Daniel; Henning, Thomas

    2011-01-01

    We explore the extent to which Spitzer Infrared Spectrograph (IRS) spectra taken at low spectral resolution can be used in quantitative studies of organic molecular emission from disks surrounding low-mass young stars. We use Spitzer IRS spectra taken in both the high- and low-resolution modules for the same sources to investigate whether it is possible to define line indices that can measure trends in the strength of the molecular features in low-resolution data. We find that trends in the HCN emission strength seen in the high-resolution data can be recovered in low-resolution data. In examining the factors that influence the HCN emission strength, we find that the low-resolution HCN flux is modestly correlated with stellar accretion rate and X-ray luminosity. Correlations of this kind are perhaps expected based on recent observational and theoretical studies of inner disk atmospheres. Our results demonstrate the potential of using the large number of low-resolution disk spectra that reside in the Spitzer archive to study the factors that influence the strength of molecular emission from disks. Such studies would complement results for the much smaller number of circumstellar disks that have been observed at high resolution with IRS.

  9. Locating Hidden Servers

    National Research Council Canada - National Science Library

    Oeverlier, Lasse; Syverson, Paul F

    2006-01-01

    .... Announced properties include server resistance to distributed DoS. Both the EFF and Reporters Without Borders have issued guides that describe using hidden services via Tor to protect the safety of dissidents as well as to resist censorship...

  10. The hidden universe

    International Nuclear Information System (INIS)

    Disney, M.

    1985-01-01

    Astronomer Disney has followed a somewhat different tack than that of most popular books on cosmology by concentrating on the notion of hidden (as in not directly observable by its own radiation) matter in the universe

  11. Spitzer IRS Observations of FU Orionis Objects

    Science.gov (United States)

    Green, J. D.; Hartmann, L.; Calvet, N.; Watson, D. M.; Ibrahimov, M.; Furlan, E.; Sargent, B.; Forrest, W. J.

    2006-09-01

    We present 5-35 μm spectra, taken with the Infrared Spectrograph (IRS) on the Spitzer Space Telescope, of five FU Orionis objects: FU Ori, V1515 Cyg, V1057 Cyg, BBW 76, and V346 Nor. All but V346 Nor reveal amorphous silicate grains in emission at 10 and 20 μm, and show water-vapor absorption bands at 5.8 and 6.8 μm and SiO or possibly methane absorption at 8 μm. These absorption features closely match these bands in model stellar photospheres-signs of the gaseous photospheres of the inner regions of these objects' accretion disks. The continuum emission at 5-8 μm is also consistent with such disks, and, for FU Orionis and BBW 76, longer wavelength emission may be fit by a model that includes moderate disk flaring. V1057 Cyg and V1515 Cyg have much more emission at longer wavelengths than the others, perhaps evidence of a substantial remnant of their natal, infalling envelopes.

  12. SPITZER INFRARED SPECTROMETER 16 μm OBSERVATIONS OF THE GOODS FIELDS

    International Nuclear Information System (INIS)

    Teplitz, Harry I.; Chary, Ranga; Elbaz, David; Le Floc'h, Emeric; Dickinson, Mark; Bridge, Carrie; Howell, Justin H.; Siana, Brian; Colbert, James; Scarlata, Claudia; Frayer, David T.; Koo, David C.; Phillips, Andrew; Papovich, Casey; Spinrad, Hyron; Stern, Daniel

    2011-01-01

    We present Spitzer 16 μm imaging of the Great Observatories Origins Deep Survey (GOODS) fields. We survey 150 arcmin 2 in each of the two GOODS fields (North and South), to an average 3σ depth of 40 and 65 μJy, respectively. We detect ∼1300 sources in both fields combined. We validate the photometry using the 3-24 μm spectral energy distribution of stars in the fields compared to Spitzer spectroscopic templates. Comparison with ISOCAM and AKARI observations in the same fields shows reasonable agreement, though the uncertainties are large. We provide a catalog of photometry, with sources cross-correlated with available Spitzer, Chandra, and Hubble Space Telescope data. Galaxy number counts show good agreement with previous results from ISOCAM and AKARI with improved uncertainties. We examine the 16-24 μm flux ratio and find that for most sources it lies within the expected locus for starbursts and infrared luminous galaxies. A color cut of S 16 /S 24 >1.4 selects mostly sources which lie at 1.1 -2 sr -1 .

  13. Spitzer and Variable Young Stars: Shining a Spotlight on Circumstellar Disks

    Science.gov (United States)

    Cody, Ann Marie; CSI 2264 Team

    2014-01-01

    Since its launch in 2003, the Spitzer Space Telescope has helped to uncover hundreds of disk bearing young stars in clusters by detecting their infrared excesses. Study of the spectral energy distributions of these objects has shed light on disk evolution, dispersal, and the relationship to planet formation. With the start of the Warm Spitzer Mission, mid-infrared time series observations have opened up a new window into the dynamic nature of these systems. Not only are young stellar objects (YSOs) highly variable, but so are their disks! I will review recent findings on mid-infrared variability in young stars, highlighting the Young Stellar Object Variability project and the joint Spitzer/CoRoT Coordinated Synoptic Investigation of NGC 2264. These efforts have resulted in a comprehensive census and categorization of YSO flux behavior at 0.5 through 4.5 microns, on timescales from hours to months. We now have evidence for multiple simultaneous variability mechanisms, supporting the picture of a highly dynamic star-disk system.

  14. SPITZER IRS SPECTRA OF DEBRIS DISKS IN THE SCORPIUS–CENTAURUS OB ASSOCIATION

    Energy Technology Data Exchange (ETDEWEB)

    Jang-Condell, Hannah [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Chen, Christine H.; Mittal, Tushar; Lisse, Carey M. [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Manoj, P. [Department of Astronomy and Astrophysics, Tata Institute of Fundamental Research, Homi Bhabha Rd., Mumbai 400005 (India); Watson, Dan [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Nesvold, Erika; Kuchner, Marc [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

    2015-08-01

    We analyze spectra obtained with the Spitzer Infrared Spectrograph (IRS) of 110 B-, A-, F-, and G-type stars with optically thin infrared excess in the Scorpius–Centaurus OB association. The ages of these stars range from 11 to 17 Myr. We fit the infrared excesses observed in these sources by Spitzer IRS and the Multiband Imaging Photometer for Spitzer (MIPS) to simple dust models according to Mie theory. We find that nearly all of the objects in our study can be fit by one or two belts of dust. Dust around lower mass stars appears to be closer in than around higher mass stars, particularly for the warm dust component in the two-belt systems, suggesting a mass-dependent evolution of debris disks around young stars. For those objects with stellar companions, all dust distances are consistent with truncation of the debris disk by the binary companion. The gaps between several of the two-belt systems can place limits on the planets that might lie between the belts, potentially constraining the mass and locations of planets that may be forming around these stars.

  15. COLORS OF ELLIPTICALS FROM GALEX TO SPITZER

    International Nuclear Information System (INIS)

    Schombert, James M.

    2016-01-01

    Multi-color photometry is presented for a large sample of local ellipticals selected by morphology and isolation. The sample uses data from the Galaxy Evolution Explorer ( GALEX ), Sloan Digital Sky Survey (SDSS), Two Micron All-Sky Survey (2MASS), and Spitzer to cover the filters NUV , ugri , JHK and 3.6 μ m. Various two-color diagrams, using the half-light aperture defined in the 2MASS J filter, are very coherent from color to color, meaning that galaxies defined to be red in one color are always red in other colors. Comparison to globular cluster colors demonstrates that ellipticals are not composed of a single age, single metallicity (e.g., [Fe/H]) stellar population, but require a multi-metallicity model using a chemical enrichment scenario. Such a model is sufficient to explain two-color diagrams and the color–magnitude relations for all colors using only metallicity as a variable on a solely 12 Gyr stellar population with no evidence of stars younger than 10 Gyr. The [Fe/H] values that match galaxy colors range from −0.5 to +0.4, much higher (and older) than population characteristics deduced from Lick/IDS line-strength system studies, indicating an inconsistency between galaxy colors and line indices values for reasons unknown. The NUV colors have unusual behavior, signaling the rise and fall of the UV upturn with elliptical luminosity. Models with blue horizontal branch tracks can reproduce this behavior, indicating the UV upturn is strictly a metallicity effect.

  16. COLORS OF ELLIPTICALS FROM GALEX TO SPITZER

    Energy Technology Data Exchange (ETDEWEB)

    Schombert, James M., E-mail: jschombe@uoregon.edu [Department of Physics, University of Oregon, Eugene, OR 97403 (United States)

    2016-12-01

    Multi-color photometry is presented for a large sample of local ellipticals selected by morphology and isolation. The sample uses data from the Galaxy Evolution Explorer ( GALEX ), Sloan Digital Sky Survey (SDSS), Two Micron All-Sky Survey (2MASS), and Spitzer to cover the filters NUV , ugri , JHK and 3.6 μ m. Various two-color diagrams, using the half-light aperture defined in the 2MASS J filter, are very coherent from color to color, meaning that galaxies defined to be red in one color are always red in other colors. Comparison to globular cluster colors demonstrates that ellipticals are not composed of a single age, single metallicity (e.g., [Fe/H]) stellar population, but require a multi-metallicity model using a chemical enrichment scenario. Such a model is sufficient to explain two-color diagrams and the color–magnitude relations for all colors using only metallicity as a variable on a solely 12 Gyr stellar population with no evidence of stars younger than 10 Gyr. The [Fe/H] values that match galaxy colors range from −0.5 to +0.4, much higher (and older) than population characteristics deduced from Lick/IDS line-strength system studies, indicating an inconsistency between galaxy colors and line indices values for reasons unknown. The NUV colors have unusual behavior, signaling the rise and fall of the UV upturn with elliptical luminosity. Models with blue horizontal branch tracks can reproduce this behavior, indicating the UV upturn is strictly a metallicity effect.

  17. Seuss's Butter Battle Book: Is There Hidden Harm?

    Science.gov (United States)

    Van Cleaf, David W.; Martin, Rita J.

    1986-01-01

    Examines whether elementary school children relate to the "harmful hidden message" about nuclear war in Dr. Seuss's THE BUTTER BATTLE BOOK. After ascertaining the children's cognitive level, they participated in activities to find hidden meanings in stories, including Seuss's book. Students failed to identify the nuclear war message in…

  18. Search for Hidden Particles

    CERN Multimedia

    Solovev, V

    The SHiP Experiment is a new general-purpose fixed target facility at the SPS to search for hidden particles as predicted by a very large number of recently elaborated models of Hidden Sectors which are capable of accommodating dark matter, neutrino oscillations, and the origin of the full baryon asymmetry in the Universe. Specifically, the experiment is aimed at searching for very weakly interacting long lived particles including Heavy Neutral Leptons - right-handed partners of the active neutrinos; light supersymmetric particles - sgoldstinos, etc.; scalar, axion and vector portals to the hidden sector. The high intensity of the SPS and in particular the large production of charm mesons with the 400 GeV beam allow accessing a wide variety of light long-lived exotic particles of such models and of SUSY. Moreover, the facility is ideally suited to study the interactions of tau neutrinos.

  19. Investigating Space Weather Events Impacting the Spitzer Space Telescope

    Science.gov (United States)

    Cheng, Leo Y.; Hunt, Joseph C. Jr.; Stowers, Kennis; Lowrance, Patrick; Stewart, Andrzej; Travis, Paul

    2014-01-01

    Our understanding of the dynamical process in the space environment has increased dramatically. A relatively new field of study called "Space Weather" has emerged in the last few decades. Fundamental to the study of space weather is an understanding of how space weather events such as solar flares and coronal mass ejections impact spacecraft in varying orbits and distances around the Sun. Specialized space weather satellite monitoring systems operated by the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) allow scientists to predict space weather events affecting critical systems on and orbiting the Earth. However, the Spitzer Space Telescope is in an orbit far outside the areas covered by those space weather monitoring systems. This poses a challenge for the Spitzer's Mission Operations Team in determining whether space weather events affect Spitzer.

  20. SPITZER IRAC PHOTOMETRY FOR TIME SERIES IN CROWDED FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Novati, S. Calchi; Beichman, C. [NASA Exoplanet Science Institute, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Gould, A.; Fausnaugh, M.; Gaudi, B. S.; Pogge, R. W.; Wibking, B.; Zhu, W.; Poleski, R. [Department of Astronomy, Ohio State University, 140 W. 18th Ave., Columbus, OH 43210 (United States); Yee, J. C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Bryden, G.; Henderson, C. B.; Shvartzvald, Y. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Carey, S. [Spitzer, Science Center, MS 220-6, California Institute of Technology, Pasadena, CA (United States); Udalski, A.; Pawlak, M.; Szymański, M. K.; Skowron, J.; Mróz, P.; Kozłowski, S. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Collaboration: Spitzer team; OGLE group; and others

    2015-12-01

    We develop a new photometry algorithm that is optimized for the Infrared Array Camera (IRAC) Spitzer time series in crowded fields and that is particularly adapted to faint or heavily blended targets. We apply this to the 170 targets from the 2015 Spitzer microlensing campaign and present the results of three variants of this algorithm in an online catalog. We present detailed accounts of the application of this algorithm to two difficult cases, one very faint and the other very crowded. Several of Spitzer's instrumental characteristics that drive the specific features of this algorithm are shared by Kepler and WFIRST, implying that these features may prove to be a useful starting point for algorithms designed for microlensing campaigns by these other missions.

  1. The hidden values

    DEFF Research Database (Denmark)

    Rasmussen, Birgitte; Jensen, Karsten Klint

    “The Hidden Values - Transparency in Decision-Making Processes Dealing with Hazardous Activities”. The report seeks to shed light on what is needed to create a transparent framework for political and administrative decisions on the use of GMOs and chemical products. It is our hope that the report...

  2. Evolving the structure of hidden Markov Models

    DEFF Research Database (Denmark)

    won, K. J.; Prugel-Bennett, A.; Krogh, A.

    2006-01-01

    A genetic algorithm (GA) is proposed for finding the structure of hidden Markov Models (HMMs) used for biological sequence analysis. The GA is designed to preserve biologically meaningful building blocks. The search through the space of HMM structures is combined with optimization of the emission...

  3. Massive hidden photons as lukewarm dark matter

    International Nuclear Information System (INIS)

    Redondo, Javier; Postma, Marieke

    2008-11-01

    We study the possibility that a keV-MeV mass hidden photon (HP), i.e. a hidden sector U(1) gauge boson, accounts for the observed amount of dark matter. We focus on the case where the HP interacts with the standard model sector only through kinetic mixing with the photon. The relic abundance is computed including all relevant plasma effects into the photon's self-energy, which leads to a resonant yield almost independent of the HP mass. The HP can decay into three photons. Moreover, if light enough it can be copiously produced in stars. Including bounds from cosmic photon backgrounds and stellar evolution, we find that the hidden photon can only give a subdominant contribution to the dark matter. This negative conclusion may be avoided if another production mechanism besides kinetic mixing is operative. (orig.)

  4. Convergence in distribution for filtering processes associated to Hidden Markov Models with densities

    OpenAIRE

    Kaijser, Thomas

    2013-01-01

    A Hidden Markov Model generates two basic stochastic processes, a Markov chain, which is hidden, and an observation sequence. The filtering process of a Hidden Markov Model is, roughly speaking, the sequence of conditional distributions of the hidden Markov chain that is obtained as new observations are received. It is well-known, that the filtering process itself, is also a Markov chain. A classical, theoretical problem is to find conditions which implies that the distributions of the filter...

  5. FAR-INFRARED PROPERTIES OF SPITZER-SELECTED LUMINOUS STARBURSTS

    International Nuclear Information System (INIS)

    Kovacs, A.; Omont, A.; Fiolet, N.; Beelen, A.; Dole, H.; Lagache, G.; Lonsdale, C.; Polletta, M.; Greve, T. R.; Borys, C.; Dowell, C. D.; Bell, T. A.; Cox, P.; De Breuck, C.; Farrah, D.; Menten, K. M.; Owen, F.

    2010-01-01

    We present SHARC-2 350 μm data on 20 luminous z ∼ 2 starbursts with S 1.2 m m > 2 mJy from the Spitzer-selected samples of Lonsdale et al. and Fiolet et al. All the sources were detected, with S 350 μ m > 25 mJy for 18 of them. With the data, we determine precise dust temperatures and luminosities for these galaxies using both single-temperature fits and models with power-law mass-temperature distributions. We derive appropriate formulae to use when optical depths are non-negligible. Our models provide an excellent fit to the 6 μm-2 mm measurements of local starbursts. We find characteristic single-component temperatures T 1 ≅ 35.5 ± 2.2 K and integrated infrared (IR) luminosities around 10 12.9±0.1 L sun for the SWIRE-selected sources. Molecular gas masses are estimated at ≅4 x 10 10 M sun , assuming κ 850 μ m = 0.15 m 2 kg -1 and a submillimeter-selected galaxy (SMG)-like gas-to-dust mass ratio. The best-fit models imply ∼>2 kpc emission scales. We also note a tight correlation between rest-frame 1.4 GHz radio and IR luminosities confirming star formation as the predominant power source. The far-IR properties of our sample are indistinguishable from the purely submillimeter-selected populations from current surveys. We therefore conclude that our original selection criteria, based on mid-IR colors and 24 μm flux densities, provides an effective means for the study of SMGs at z ∼ 1.5-2.5.

  6. Size and Albedo of Irregular Saturnian Satellites from Spitzer Observations

    NARCIS (Netherlands)

    Mueller, Michael; Grav, T.; Trilling, D.; Stansberry, J.; Sykes, M.

    2008-01-01

    Using MIPS onboard the Spitzer Space Telescope, we observed the thermal emission (24 and, for some targets, 70 um) of eight irregular satellites of Saturn: Albiorix, Siarnaq, Paaliaq, Kiviuq, Ijiraq, Tarvos, Erriapus, and Ymir. We determined the size and albedo of all targets. An analysis of

  7. ExploreNEOs: The Warm Spitzer Near Earth Object Survey

    NARCIS (Netherlands)

    Trilling, D. E.; Hora, J. L.; Mueller, M.; Thomas, C. A.; Harris, A. W.; Hagen, A. R.; Mommert, M.; Benner, L.; Bhattacharya, B.; Bottke, W. F.; Chesley, S.; Delbo, M.; Emery, J. P.; Fazio, G.; Kistler, J. L.; Mainzer, A.; Morbidelli, A.; Penprase, B.; Smith, H. A.; Spahr, T. B.; Stansberry, J. A.

    2012-01-01

    We have observed some 600 near Earth objects (NEOs) at 3.6 and 4.5 microns with the Warm Spitzer Space Telescope. We derive the albedo and diameter for each NEO to characterize global properties of the NEO population, among other goals.

  8. Robert Spitzer and psychiatric classification: technical challenges and ethical dilemmas.

    Science.gov (United States)

    Jacob, K S

    2016-01-01

    Dr Robert Leopold Spitzer (May 22, 1932-December 25, 2015), the architect of modern psychiatric diagnostic criteria and classification, died recently at the age of 83 in Seattle. Under his leadership, the American Psychiatric Association's (APA) Diagnostic and Statistical Manuals (DSM) became the international standard.

  9. SPITZER TRANSITS OF THE SUPER-EARTH GJ1214b AND IMPLICATIONS FOR ITS ATMOSPHERE

    Energy Technology Data Exchange (ETDEWEB)

    Fraine, Jonathan D.; Deming, Drake [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Gillon, Michaeel; Jehin, Emmanueel [Institute d' Astrophysique et de Geophysique, Universite de Liege, Liege (Belgium); Demory, Brice-Olivier; Benneke, Bjoern; Seager, Sara [Department of Earth, Atmospheric and Planetary Sciences, and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Lewis, Nikole K. [Department of Planetary Sciences and Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States); Knutson, Heather [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Desert, Jean-Michel, E-mail: jfraine@astro.umd.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States)

    2013-03-10

    We observed the transiting super-Earth exoplanet GJ1214b using warm Spitzer at 4.5 {mu}m wavelength during a 20 day quasi-continuous sequence in 2011 May. The goals of our long observation were to accurately define the infrared transit radius of this nearby super-Earth, to search for the secondary eclipse, and to search for other transiting planets in the habitable zone of GJ1214. We here report results from the transit monitoring of GJ1214b, including a reanalysis of previous transit observations by Desert et al. In total, we analyze 14 transits of GJ1214b at 4.5 {mu}m, 3 transits at 3.6 {mu}m, and 7 new ground-based transits in the I+z band. Our new Spitzer data by themselves eliminate cloudless solar composition atmospheres for GJ1214b, and methane-rich models from Howe and Burrows. Using our new Spitzer measurements to anchor the observed transit radii of GJ1214b at long wavelengths, and adding new measurements in I+z, we evaluate models from Benneke and Seager and Howe and Burrows using a {chi}{sup 2} analysis. We find that the best-fit model exhibits an increase in transit radius at short wavelengths due to Rayleigh scattering. Pure water atmospheres are also possible. However, a flat line (no atmosphere detected) remains among the best of the statistically acceptable models, and better than pure water atmospheres. We explore the effect of systematic differences among results from different observational groups, and we find that the Howe and Burrows tholin-haze model remains the best fit, even when systematic differences among observers are considered.

  10. Hidden neural networks

    DEFF Research Database (Denmark)

    Krogh, Anders Stærmose; Riis, Søren Kamaric

    1999-01-01

    A general framework for hybrids of hidden Markov models (HMMs) and neural networks (NNs) called hidden neural networks (HNNs) is described. The article begins by reviewing standard HMMs and estimation by conditional maximum likelihood, which is used by the HNN. In the HNN, the usual HMM probability...... parameters are replaced by the outputs of state-specific neural networks. As opposed to many other hybrids, the HNN is normalized globally and therefore has a valid probabilistic interpretation. All parameters in the HNN are estimated simultaneously according to the discriminative conditional maximum...... likelihood criterion. The HNN can be viewed as an undirected probabilistic independence network (a graphical model), where the neural networks provide a compact representation of the clique functions. An evaluation of the HNN on the task of recognizing broad phoneme classes in the TIMIT database shows clear...

  11. Hidden treasures - 50 km points of interests

    Science.gov (United States)

    Lommi, Matias; Kortelainen, Jaana

    2015-04-01

    Tampere is third largest city in Finland and a regional centre. During 70's there occurred several communal mergers. Nowadays this local area has both strong and diversed identity - from wilderness and agricultural fields to high density city living. Outside the city center there are interesting geological points unknown for modern city settlers. There is even a local proverb, "Go abroad to Teisko!". That is the area the Hidden Treasures -student project is focused on. Our school Tammerkoski Upper Secondary School (or Gymnasium) has emphasis on visual arts. We are going to offer our art students scientific and artistic experiences and knowledge about the hidden treasures of Teisko area and involve the Teisko inhabitants into this project. Hidden treasures - Precambrian subduction zone and a volcanism belt with dense bed of gold (Au) and arsenic (As), operating goldmines and quarries of minerals and metamorphic slates. - North of subduction zone a homogenic precambrian magmastone area with quarries, products known as Kuru Grey. - Former ashores of post-glasial Lake Näsijärvi and it's sediments enabled the developing agriculture and sustained settlement. Nowadays these ashores have both scenery and biodiversity values. - Old cattle sheds and dairy buildings made of local granite stones related to cultural stonebuilding inheritance. - Local active community of Kapee, about 100 inhabitants. Students will discover information of these "hidden" phenomena, and rendering this information trough Enviromental Art Method. Final form of this project will be published in several artistic and informative geocaches. These caches are achieved by a GPS-based special Hidden Treasures Cycling Route and by a website guiding people to find these hidden points of interests.

  12. DUST EVOLUTION IN PROTOPLANETARY DISKS AROUND HERBIG Ae/Be STARS-THE SPITZER VIEW

    International Nuclear Information System (INIS)

    Juhasz, A.; Bouwman, J.; Henning, Th.; Acke, B.; Waters, L. B. F. M.; Van den Ancker, M. E.; Meeus, G.; Min, M.; Dominik, C.; Tielens, A. G. G. M.

    2010-01-01

    In this paper, we present mid-infrared spectra of a comprehensive set of Herbig Ae/Be stars observed with the Spitzer Space Telescope. The signal-to-noise ratio of these spectra is very high, ranging between about a hundred and several hundreds. During the analysis of these data we tested the validity of standardized protoplanetary dust models and studied grain growth and crystal formation. On the basis of the analyzed spectra, the major constituents of protoplanetary dust around Herbig Ae/Be stars are amorphous silicates with olivine and pyroxene stoichiometry, crystalline forsterite, and enstatite and silica. No other solid-state features, indicating other abundant dust species, are present in the Spitzer spectra. Deviations of the synthetic spectra from the observations are most likely related to grain shape effects and uncertainties in the iron content of the dust grains. Our analysis revealed that larger grains are more abundant in the disk atmosphere of flatter disks than in that of flared disks, indicating that grain growth and sedimentation decrease the disk flaring. We did not find, however, correlations between the value of crystallinity and any of the investigated system parameters. Our analysis shows that enstatite is more concentrated toward the warm inner disk than forsterite, in contrast to predictions of equilibrium condensation models. None of the three crystal formation mechanisms proposed so far can alone explain all our findings. It is very likely that all three play at least some role in the formation of crystalline silicates.

  13. Analysis of Spitzer-IRS spectra of hyperluminous infrared galaxies

    Science.gov (United States)

    Ruiz, A.; Risaliti, G.; Nardini, E.; Panessa, F.; Carrera, F. J.

    2013-01-01

    Context. Hyperluminous infrared galaxies (HLIRG) are the most luminous persistent objects in the Universe. They exhibit extremely high star formation rates, and most of them seem to harbour an active galactic nucleus (AGN). They are unique laboratories for investigating the most extreme star formation and its connection to super-massive black hole growth. Aims: The relative AGN and starburst (SB) contributions to the total output in these objects is still debated. Our aim is to disentangle the AGN and SB emission of a sample of thirteen HLIRG. Methods: We studied the MIR low-resolution spectra of a sample of thirteen HLIRG obtained with the Infrared Spectrograph on board Spitzer. The 5-8 μm range is an optimal window for detecting AGN activity even in a heavily obscured environment. We performed an SB/AGN decomposition of the continuum using templates, which has been successfully applied for ULIRG in previous works. Results: The MIR spectra of all sources is largely dominated by AGN emission. By converting the 6 μm luminosity into IR luminosity, we found that ~80% of the sample shows an IR output dominated by the AGN emission. However, the SB activity is significant in all sources (mean SB contribution ~30%), showing star formation rates ~300-3000 M⊙ yr-1. With X-ray and MIR data we estimated the dust covering factor (CF) of these HLIRG, finding that a significant fraction presents a CF consistent with unity. Along with the high X-ray absorption shown by these sources, this suggests that large amounts of dust and gas enshroud the nucleus of these HLIRG, as also observed in ULIRG. Conclusions: Our results agree with previous studies of the IR SED of HLIRG using radiative transfer models, and we find strong evidence that all HLIRG harbour an AGN. Moreover, this work provides further support for the idea that AGN and SB are both crucial to understanding the properties of HLIRG. Our study of the CF supports the hypothesis that HLIRG can be divided into two

  14. The Hidden Curriculum

    Directory of Open Access Journals (Sweden)

    Onatra Amparo

    2004-08-01

    Full Text Available This article shows the way hidden curriculum goes farther than just being the conscious and unconscious setting within the formal instruction context. It also shapes students personality and assigns to each individual the role they are supposed to play in society. In this process, interaction with the teacher is crucial since he/she is the one who directly moulds and cultivates the singularity of students according to the specific demands of the social class to which they belong. This phenomenon is well described in research conducted by Jane Anyon (1980 which is referred to in this paper as an example of the influence of the hidden curriculum on school life. Key words: Hidden Curriculum, Unconscious Setting, Teacher’s Role, Singularity, Society Este artículo muestra cómo el currículo oculto va más allá de ser simplemente el escenario consciente e inconsciente en el que se desarrolla la instrucción formal. El currículo oculto define la personalidad del estudiante y asigna a cada uno el papel que se supone debe ocupar en la sociedad. En este proceso, la interacción directa con el docente es decisiva ya que es éste quien directamente moldea y cultiva la singularidad de los estudiantes según las exigencias específicas de la clase social a la que pertenecen. Dicho fenómeno se describe muy bien en la investigación adelantada por Jane Anyon (1980, a la cual se hace referencia en este escrito, como ejemplo de la influencia del currículo oculto en la vida escolar. Palabras claves: Currículo Oculto, Escenario Inconsciente, Rol del Docente, Singularidad, Sociedad

  15. Naturally light hidden photons in LARGE volume string compactifications

    Energy Technology Data Exchange (ETDEWEB)

    Goodsell, M. [LPTHE, Univ. Pierre et Marie Curie, Paris (France); Jaeckel, J. [Inst. for Particle Physics Phenomenology, Univ. Durham (United Kingdom); Redondo, J.; Ringwald, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2009-09-15

    Extra ''hidden'' U(1) gauge factors are a generic feature of string theory that is of particular phenomenological interest. They can kinetically mix with the Standard Model photon and are thereby accessible to a wide variety of astrophysical and cosmological observations and laboratory experiments. In this paper we investigate the masses and the kinetic mixing of hidden U(1)s in LARGE volume compactifications of string theory. We find that in these scenarios the hidden photons can be naturally light and that their kinetic mixing with the ordinary electromagnetic photon can be of a size interesting for near future experiments and observations. (orig.)

  16. Naturally light hidden photons in LARGE volume string compactifications

    International Nuclear Information System (INIS)

    Goodsell, M.; Jaeckel, J.; Redondo, J.; Ringwald, A.

    2009-09-01

    Extra ''hidden'' U(1) gauge factors are a generic feature of string theory that is of particular phenomenological interest. They can kinetically mix with the Standard Model photon and are thereby accessible to a wide variety of astrophysical and cosmological observations and laboratory experiments. In this paper we investigate the masses and the kinetic mixing of hidden U(1)s in LARGE volume compactifications of string theory. We find that in these scenarios the hidden photons can be naturally light and that their kinetic mixing with the ordinary electromagnetic photon can be of a size interesting for near future experiments and observations. (orig.)

  17. SPITZER SPACE TELESCOPE MID-IR LIGHT CURVES OF NEPTUNE

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, John; Rebull, Luisa; Carey, Sean J.; Krick, Jessica; Ingalls, James G.; Lowrance, Patrick; Glaccum, William [Spitzer Science Center (SSC), California Institute of Technology, Pasadena, CA 91125 (United States); Marley, Mark S. [NASA Ames Research Center, Space Sciences and Astrobiology Division, MS245-3, Moffett Field, CA 94035 (United States); Gizis, John E. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Kirkpatrick, J. Davy [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Simon, Amy A. [NASA Goddard Space Flight Center, Solar System Exploration Division (690.0), 8800 Greenbelt Road, Greenbelt, MD 20771 (United States); Wong, Michael H. [University of California, Department of Astronomy, Berkeley CA 94720-3411 (United States)

    2016-11-01

    We have used the Spitzer Space Telescope in 2016 February to obtain high cadence, high signal-to-noise, 17 hr duration light curves of Neptune at 3.6 and 4.5 μ m. The light curve duration was chosen to correspond to the rotation period of Neptune. Both light curves are slowly varying with time, with full amplitudes of 1.1 mag at 3.6 μ m and 0.6 mag at 4.5 μ m. We have also extracted sparsely sampled 18 hr light curves of Neptune at W1 (3.4 μ m) and W2 (4.6 μ m) from the Wide-feld Infrared Survey Explorer ( WISE )/ NEOWISE archive at six epochs in 2010–2015. These light curves all show similar shapes and amplitudes compared to the Spitzer light curves but with considerable variation from epoch to epoch. These amplitudes are much larger than those observed with Kepler / K 2 in the visible (amplitude ∼0.02 mag) or at 845 nm with the Hubble Space Telescope ( HST ) in 2015 and at 763 nm in 2016 (amplitude ∼0.2 mag). We interpret the Spitzer and WISE light curves as arising entirely from reflected solar photons, from higher levels in Neptune’s atmosphere than for K 2. Methane gas is the dominant opacity source in Neptune’s atmosphere, and methane absorption bands are present in the HST 763 and 845 nm, WISE W1, and Spitzer 3.6 μ m filters.

  18. Does Immigrant Residential Crowding Reflect Hidden Homelessness?

    Directory of Open Access Journals (Sweden)

    Michael Haan

    2011-01-01

    Full Text Available Compared to the Canadian-born, immigrants are under-represented among Canada’s homeless population, when their decline in economic wellbeing is considered alongside their relative absence in homeless shelters. One way to explain this oddity, proposed in both academic and popular literature, is that immigrant communities employ unique avoidance strategies, such as within-group co-residence, to help keep co-ethnics off the streets and out of homeless shelters. In this paper I use the 2001 census of Canada to investigate the extent to which heightened levels of residential crowding might reflect “hidden homelessness”. I find mixed evidence to support this link, and, if anything, find some evidence to suggest that the link between residential crowding and hidden homelessness, if one exists, is strongest for the Canadian-born.

  19. Albedo Corrections for High Albedo Near Earth Objects Observed With Spitzer

    Science.gov (United States)

    Gustafsson, Annika; Trilling, David E.; Mommert, Michael; Hora, Joseph L.

    2017-10-01

    Thermal infrared observations are the most effective way to measure asteroid diameter and albedo. Major surveys like NEOWISE and NEOSurvey return a small fraction of objects with albedo values higher than that believed to exist in the near-Earth object (NEO) population. About 10% of Spitzer-observed NEOs have nominal albedo solutions greater than 0.5. There are many possible causes for these unrealistically high albedos, including thermal lightcurves (leading to a mis-estimate of asteroid diameter) or inaccurate absolute visual magnitudes (either from poor photometry or lightcurve effects). We present here the results of a ground-based optical photometric study of 36 high albedo NEOs from NEOSurvey (Trilling et al. 2016) using measurements from the Discovery Channel Telescope. Our findings indicate that uncertainty in the diameter has the most impact on the derived albedo of our targets, while the uncertainty in the H-magnitude and slope parameter have smaller effects. We supply corrected albedos for our target list, as well as a systematic offset dependent on the solar phase angle of the object (Mommert el al. 2017). These corrected albedo values will help constrain the albedo range in the population to better reflect its physical characteristics. This work is based in part on the observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.

  20. The Hidden Gifts of Quiet Kids

    Science.gov (United States)

    Trierweiler, Hannah

    2006-01-01

    The author relates that she was an introvert child. It has always taken her time and energy to find her place in a group. As a grown-up, she still needed quiet time to regroup during a busy day. In this article, the author presents an interview with Marti Olsen Laney, author of "The Hidden Gifts of the Introverted Child." During the interview,…

  1. Cold dark matter from the hidden sector

    Energy Technology Data Exchange (ETDEWEB)

    Arias, Paola [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Pontificia Univ. Catolica de Chile, Santiago (Chile). Facultad de Fisica

    2012-02-15

    Weakly interacting slim particles (WISPs) such as hidden photons (HP) and axion-like particles (ALPs) have been proposed as cold dark matter candidates. They might be produced non-thermally via the misalignment mechanism, similarly to cold axions. In this talk we review the main processes of thermalisation of HP and we compute the parameter space that may survive as cold dark matter population until today. Our findings are quite encouraging for experimental searches in the laboratory in the near future.

  2. Serendipity Observations of Far Infrared Cirrus Emission in the Spitzer Infrared Nearby Galaxies Survey: Analysis of Far-Infrared Correlations

    Science.gov (United States)

    Bot, Caroline; Helou, George; Boulanger, François; Lagache, Guilaine; Miville-Deschenes, Marc-Antoine; Draine, Bruce; Martin, Peter

    2009-04-01

    We present an analysis of far-infrared (FIR) dust emission from diffuse cirrus clouds. This study is based on serendipitous observations at 160 μm at high-galactic latitude with the Multiband Imaging Photometer onboard the Spitzer Space Telescope by the Spitzer Infrared Nearby Galaxies Survey. These observations are complemented with IRIS data at 100 and 60 μm and constitute one of the most sensitive and unbiased samples of FIR observations at a small scale of diffuse interstellar clouds. Outside regions dominated by the cosmic infrared background fluctuations, we observe a substantial scatter in the 160/100 colors from cirrus emission. We compared the 160/100 color variations to 60/100 colors in the same fields and find a trend of decreasing 60/100 with increasing 160/100. This trend cannot be accounted for by current dust models by changing solely the interstellar radiation field. It requires a significant change of dust properties such as grain size distribution or emissivity or a mixing of clouds in different physical conditions along the line of sight. These variations are important as a potential confusing foreground for extragalactic studies. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA.

  3. SPITZER OBSERVATIONS OF WHITE DWARFS: THE MISSING PLANETARY DEBRIS AROUND DZ STARS

    International Nuclear Information System (INIS)

    Xu, S.; Jura, M.

    2012-01-01

    We report a Spitzer/Infrared Array Camera search for infrared excesses around white dwarfs, including 14 newly observed targets and 16 unpublished archived stars. We find a substantial infrared excess around two warm white dwarfs—J220934.84+122336.5 and WD 0843+516, the latter apparently being the hottest white dwarf known to display a close-in dust disk. Extending previous studies, we find that the fraction of white dwarfs with dust disks increases as the star's temperature increases; for stars cooler than 10,000 K, even the most heavily polluted ones do not have ∼1000 K dust. There is tentative evidence that the dust disk occurrence is correlated with the volatility of the accreted material. In the Appendix, we modify a previous analysis to clarify how Poynting-Robertson drag might play an important role in transferring materials from a dust disk into a white dwarf's atmosphere.

  4. Discovering hidden viral piracy.

    Science.gov (United States)

    Kim, Eddo; Kliger, Yossef

    2005-12-01

    Viruses and developers of anti-inflammatory therapies share a common interest in proteins that manipulate the immune response. Large double-stranded DNA viruses acquire host proteins to evade host defense mechanisms. Hence, viral pirated proteins may have a therapeutic potential. Although dozens of viral piracy events have already been identified, we hypothesized that sequence divergence impedes the discovery of many others. We developed a method to assess the number of viral/human homologs and discovered that at least 917 highly diverged homologs are hidden in low-similarity alignment hits that are usually ignored. However, these low-similarity homologs are masked by many false alignment hits. We therefore applied a filtering method to increase the proportion of viral/human homologous proteins. The homologous proteins we found may facilitate functional annotation of viral and human proteins. Furthermore, some of these proteins play a key role in immune modulation and are therefore therapeutic protein candidates.

  5. SPATIAL VARIATIONS OF PAH PROPERTIES IN M17SW REVEALED BY SPITZER /IRS SPECTRAL MAPPING

    Energy Technology Data Exchange (ETDEWEB)

    Yamagishi, M. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Chuo-ku, Sagamihara 252-5210 (Japan); Kaneda, H.; Ishihara, D.; Oyabu, S.; Suzuki, T.; Nishimura, A.; Kohno, M. [Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan); Onaka, T.; Ohashi, S. [Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Nagayama, T.; Matsuo, M. [Graduate School of Science and Engineering, Kagoshima University, 1-21-35 Korimoto, Kagoshima 890-0065 (Japan); Umemoto, T.; Minamidani, T.; Fujita, S. [Nobeyama Radio Observatory, National Astronomical Observatory of Japan (NAOJ), National Institutes of Natural Sciences (NINS), 462-2, Nobeyama, Minamimaki, Minamisaku, Nagano 384-1305 (Japan); Tsuda, Y., E-mail: yamagish@ir.isas.jaxa.jp [Graduate School of Science and Engineering, Meisei University, 2-1-1 Hodokubo, Hino, Tokyo 191-0042 (Japan)

    2016-12-20

    We present Spitzer /IRS mid-infrared spectral maps of the Galactic star-forming region M17 as well as IRSF/SIRIUS Br γ and Nobeyama 45 m/FOREST {sup 13}CO ( J = 1–0) maps. The spectra show prominent features due to polycyclic aromatic hydrocarbons (PAHs) at wavelengths of 6.2, 7.7, 8.6, 11.3, 12.0, 12.7, 13.5, and 14.2  μ m. We find that the PAH emission features are bright in the region between the H ii region traced by Br γ and the molecular cloud traced by {sup 13}CO, supporting that the PAH emission originates mostly from photo-dissociation regions. Based on the spatially resolved Spitzer /IRS maps, we examine spatial variations of the PAH properties in detail. As a result, we find that the interband ratio of PAH 7.7  μ m/PAH 11.3  μ m varies locally near M17SW, but rather independently of the distance from the OB stars in M17, suggesting that the degree of PAH ionization is mainly controlled by local conditions rather than the global UV environments determined by the OB stars in M17. We also find that the interband ratios of the PAH 12.0  μ m, 12.7  μ m, 13.5  μ m, and 14.2  μ m features to the PAH 11.3  μ m feature are high near the M17 center, which suggests structural changes of PAHs through processing due to intense UV radiation, producing abundant edgy irregular PAHs near the M17 center.

  6. THE SPITZER -HETDEX EXPLORATORY LARGE-AREA SURVEY

    International Nuclear Information System (INIS)

    Papovich, C.; Shipley, H. V.; Mehrtens, N.; Lanham, C.; DePoy, D. L.; Kawinwanichakij, L.; Lacy, M.; Ciardullo, R.; Gronwall, C.; Finkelstein, S. L.; Drory, N.; Gebhardt, K.; Hill, G. J.; Jogee, S.; Bassett, R.; Behroozi, P.; Blanc, G. A.; Jong, R. S. de; Gawiser, E.; Hopp, U.

    2016-01-01

    We present post-cryogenic Spitzer imaging at 3.6 and 4.5 μ m with the Infrared Array Camera (IRAC) of the Spitzer /HETDEX Exploratory Large-Area (SHELA) survey. SHELA covers ≈24 deg 2 of the Sloan Digital Sky Survey “Stripe 82” region, and falls within the footprints of the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) and the Dark Energy Survey. The HETDEX blind R ∼ 800 spectroscopy will produce ∼200,000 redshifts from the Ly α emission for galaxies in the range 1.9 <  z  < 3.5, and an additional ∼200,000 redshifts from the [O ii] emission for galaxies at z  < 0.5. When combined with deep ugriz images from the Dark Energy Camera, K -band images from NEWFIRM, and other ancillary data, the IRAC photometry from Spitzer will enable a broad range of scientific studies of the relationship between structure formation, galaxy stellar mass, halo mass, the presence of active galactic nuclei, and environment over a co-moving volume of ∼0.5 Gpc 3 at 1.9 <  z  < 3.5. Here, we discuss the properties of the SHELA IRAC data set, including the data acquisition, reduction, validation, and source catalogs. Our tests show that the images and catalogs are 80% (50%) complete to limiting magnitudes of 22.0 (22.6) AB mag in the detection image, which is constructed from the weighted sum of the IRAC 3.6 and 4.5 μ m images. The catalogs reach limiting sensitivities of 1.1  μ Jy at both 3.6 and 4.5 μ m (1 σ , for R = 2″ circular apertures). As a demonstration of the science, we present IRAC number counts, examples of highly temporally variable sources, and galaxy surface density profiles of rich galaxy clusters. In the spirit of the Spitzer Exploratory programs, we provide all of the images and catalogs as part of the publication.

  7. Measurement of the Transverse Spitzer Resistivity during Collisional Magnetic Reconnection

    International Nuclear Information System (INIS)

    Trintchouk, F.; Yamada, M.; Ji, H.; Kulsrud, R.M.; Carter, T.A.

    2000-01-01

    Measurement of the transverse resistivity was carried out in a reconnecting current sheet where the mean free path for the Coulomb collision is smaller than the thickness of the sheet. In a collisional neutral sheet without a guide field, the transverse resistivity is directly related to the reconnection rate. A remarkable agreement is found between the measured resistivity and the classical value derived by L. Spitzer. In his calculation the transverse resistivity for the electrons is higher than the parallel resistivity by a factor of 1.96. The measured values have verified this theory to within 30% errors

  8. Variational Infinite Hidden Conditional Random Fields

    NARCIS (Netherlands)

    Bousmalis, Konstantinos; Zafeiriou, Stefanos; Morency, Louis-Philippe; Pantic, Maja; Ghahramani, Zoubin

    2015-01-01

    Hidden conditional random fields (HCRFs) are discriminative latent variable models which have been shown to successfully learn the hidden structure of a given classification problem. An Infinite hidden conditional random field is a hidden conditional random field with a countably infinite number of

  9. Managing Hidden Costs of Offshoring

    DEFF Research Database (Denmark)

    Larsen, Marcus M.; Pedersen, Torben

    2014-01-01

    This chapter investigates the concept of the ‘hidden costs’ of offshoring, i.e. unexpected offshoring costs exceeding the initially expected costs. Due to the highly undefined nature of these costs, we position our analysis towards the strategic responses of firms’ realisation of hidden costs. In......-by-doing process, where hidden costs motivate firms and their employees to search for new and better knowledge on how to successfully manage the organisation. We illustrate this thesis based on the case of the LEGO Group........ In this regard, we argue that a major response to the hidden costs of offshoring is the identification and utilisation of strategic mechanisms in the organisational design to eventually achieving system integration in a globally dispersed and disaggregated organisation. This is heavily moderated by a learning...

  10. Spitzer ’s View of the Candidate Cluster and Protocluster Catalog (CCPC)

    Energy Technology Data Exchange (ETDEWEB)

    Franck, J. R.; McGaugh, S. S. [Case Western Reserve University, 10900 Euclid Ave., Cleveland, OH 44106 (United States)

    2017-02-10

    The Candidate Cluster and Protocluster Catalog contains 218 galaxy overdensities composed of more than 2000 galaxies with spectroscopic redshifts spanning the first few Gyr after the Big Bang (2.0 ≤ z < 6.6). We use Spitzer archival data to track the underlying stellar mass of these overdense regions in various temporal cross sections by building rest-frame near-infrared luminosity functions (LFs) across the span of redshifts. This exercise maps the stellar growth of protocluster galaxies, as halos in the densest environments should be the most massive from hierarchical accretion. The characteristic apparent magnitude, m *( z ), is relatively flat from 2.0 ≤ z < 6.6, consistent with a passive evolution of an old stellar population. This trend maps smoothly to lower redshift results of cluster galaxies from other works. We find no difference in the LFs of galaxies in the field versus protoclusters at a given redshift apart from their density.

  11. Hidden Statistics of Schroedinger Equation

    Science.gov (United States)

    Zak, Michail

    2011-01-01

    Work was carried out in determination of the mathematical origin of randomness in quantum mechanics and creating a hidden statistics of Schr dinger equation; i.e., to expose the transitional stochastic process as a "bridge" to the quantum world. The governing equations of hidden statistics would preserve such properties of quantum physics as superposition, entanglement, and direct-product decomposability while allowing one to measure its state variables using classical methods.

  12. A MID-INFRARED IMAGING SURVEY OF SUBMILLIMETER-SELECTED GALAXIES WITH THE SPITZER SPACE TELESCOPE

    International Nuclear Information System (INIS)

    Hainline, Laura J.; Blain, A. W.; Smail, Ian; Frayer, D. T.; Chapman, S. C.; Ivison, R. J.; Alexander, D. M.

    2009-01-01

    We present Spitzer-IRAC and MIPS mid-IR observations of a sample of 73 radio-detected submillimeter-selected galaxies (SMGs) with spectroscopic redshifts, the largest such sample published to date. From our data, we find that IRAC colors of SMGs are much more uniform as compared with rest-frame UV and optical colors, and z>1.5 SMGs tend to be redder in their mid-IR colors than both field galaxies and lower-z SMGs. However, the IRAC colors of the SMGs overlap those of field galaxies sufficiently that color-magnitude and color-color selection criteria suggested in the literature to identify SMG counterparts produce ambiguous counterparts within an 8'' radius in 20%-35% of cases. We use a rest-frame J-H versus H-K color-color diagram and a S 24 /S 8.0 versus S 8.0 /S 4.5 color-color diagram to determine that 13%-19% of our sample are likely to contain active galactic nuclei which dominate their mid-IR emission. We observe in the rest-frame JHK colors of our sample that the rest-frame near-IR emission of SMGs does not resemble that of the compact nuclear starburst observed in local ultraluminous IR galaxies and is consistent with more widely distributed star formation. We take advantage of the fact that many high-z galaxy populations selected at different wavelengths are detected by Spitzer to carry out a brief comparison of mid-IR properties of SMGs to UV-selected high-z galaxies, 24 μm-selected galaxies, and high-z radio galaxies, and find that SMGs have mid-IR fluxes and colors which are consistent with being more massive and more reddened than UV-selected galaxies, while the IRAC colors of SMGs are most similar to powerful high-z radio galaxies.

  13. THE SPITZER INFRARED SPECTROGRAPH DEBRIS DISK CATALOG. II. SILICATE FEATURE ANALYSIS OF UNRESOLVED TARGETS

    Energy Technology Data Exchange (ETDEWEB)

    Mittal, Tushar [Department of Earth and Planetary Science, University of California Berkeley, Berkeley, CA 94720-4767 (United States); Chen, Christine H. [Space Telescope Science Institute, 3700 San Martin Drive Baltimore, MD 21218 (United States); Jang-Condell, Hannah [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States); Manoj, P. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Sargent, Benjamin A. [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Watson, Dan M. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Lisse, Carey M., E-mail: cchen@stsci.edu [Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States)

    2015-01-10

    During the Spitzer Space Telescope cryogenic mission, astronomers obtained Infrared Spectrograph (IRS) observations of hundreds of debris disk candidates that have been compiled in the Spitzer IRS Debris Disk Catalog. We have discovered 10 and/or 20 μm silicate emission features toward 120 targets in the catalog and modeled the IRS spectra of these sources, consistent with MIPS 70 μm observations, assuming that the grains are composed of silicates (olivine, pyroxene, forsterite, and enstatite) and are located either in a continuous disk with power-law size and surface density distributions or thin rings that are well-characterized using two separate dust grain temperatures. For systems better fit by the continuous disk model, we find that (1) the dust size distribution power-law index is consistent with that expected from a collisional cascade, q = 3.5-4.0, with a large number of values outside this range, and (2) the minimum grain size, a {sub min}, increases with stellar luminosity, L {sub *}, but the dependence of a {sub min} on L {sub *} is weaker than expected from radiation pressure alone. In addition, we also find that (3) the crystalline fraction of dust in debris disks evolves as a function of time with a large dispersion in crystalline fractions for stars of any particular stellar age or mass, (4) the disk inner edge is correlated with host star mass, and (5) there exists substantial variation in the properties of coeval disks in Sco-Cen, indicating that the observed variation is probably due to stochasticity and diversity in planet formation.

  14. Size and Albedo of Irregular Saturnian Satellites from Spitzer Observations

    Science.gov (United States)

    Mueller, Michael; Grav, T.; Trilling, D.; Stansberry, J.; Sykes, M.

    2008-09-01

    Using MIPS onboard the Spitzer Space Telescope, we observed the thermal emission (24 and, for some targets, 70 um) of eight irregular satellites of Saturn: Albiorix, Siarnaq, Paaliaq, Kiviuq, Ijiraq, Tarvos, Erriapus, and Ymir. We determined the size and albedo of all targets. An analysis of archived MIPS observations of Phoebe reproduces Cassini results very accurately, thereby validating our method. For all targets, the geometric albedo is found to be low, probably below 10% and clearly below 15%. Irregular satellites are much darker than the large regular satellites. Their albedo is, however, quite similar to that of small bodies in the outer Solar System (such as cometary nuclei, Jupiter Trojans, or TNOs). This is consistent with color measurements as well as dynamical considerations which suggest a common origin of the said populations. There appear to be significant object-to-object albedo differences. Similar albedos found for some members of dynamical clusters support the idea that they may have originated in the breakup of a parent body. For three satellites, thermal data at two wavelengths are available, enabling us to constrain their thermal properties. Sub-solar temperatures are similar to that found from Cassini's Phoebe fly-by. This suggests a rather low thermal inertia, as expected for regolith-covered objects. This work is based on observations made with the Spitzer Space Telescope, which is operated by JPL under a contract with NASA. Support for this work was provided by NASA.

  15. Albedo and Diameter Distributions of Asteroid Families Using the Spitzer Asteroid Catalog

    NARCIS (Netherlands)

    Enga, Marie-Therese; Trilling, D.; Mueller, M.; Wasserman, L.; Sykes, M.; Blaylock, M.; Stansberry, J.; Bhattacharya, B.; Spahr, T.

    2009-01-01

    The Spitzer Asteroid Catalog contains flux measurements of asteroidsserendipitously observed in publicly available Spitzer data. At present,this catalog contains some 10,000 measurements at 24 microns only, andwill ultimately contain 100,000 measurements or more. These measurements, along with with

  16. Multiple asteroid systems : Dimensions and thermal properties from Spitzer Space Telescope and ground-based observations

    NARCIS (Netherlands)

    Marchis, F.; Enriquez, J. E.; Emery, J. P.; Mueller, M.; Baek, M.; Pollock, J.; Assafin, M.; Vieira Martins, R.; Berthier, J.; Vachier, F.; Cruikshank, D. P.; Lim, L. F.; Reichart, D. E.; Ivarsen, K. M.; Haislip, J. B.; LaCluyze, A. P.

    2012-01-01

    We collected mid-IR spectra from 5.2 to 38 μm using the Spitzer Space Telescope Infrared Spectrograph of 28 asteroids representative of all established types of binary groups. Photometric lightcurves were also obtained for 14 of them during the Spitzer observations to provide the context of the

  17. Global Update and Trends of Hidden Hunger, 1995-2011: The Hidden Hunger Index

    Science.gov (United States)

    Stevens, Gretchen A.; Ezzati, Majid; Black, Robert E.; Kraemer, Klaus

    2015-01-01

    Background Deficiencies in essential vitamins and minerals–also termed hidden hunger–are pervasive and hold negative consequences for the cognitive and physical development of children. Methods This analysis evaluates the change in hidden hunger over time in the form of one composite indicator–the Hidden Hunger Index (HHI)–using an unweighted average of prevalence estimates from the Nutrition Impact Model Study for anemia due to iron deficiency, vitamin A deficiency, and stunting (used as a proxy indicator for zinc deficiency). Net changes from 1995–2011 and population weighted regional means for various time periods are measured. Findings Globally, hidden hunger improved (-6.7 net change in HHI) from 1995–2011. Africa was the only region to see a deterioration in hidden hunger (+1.9) over the studied time period; East Asia and the Pacific performed exceptionally well (-13.0), while other regions improved only slightly. Improvements in HHI were mostly due to reductions in zinc and vitamin A deficiencies, while anemia due to iron deficiency persisted and even increased. Interpretation This analysis is critical for informing and tracking the impact of policy and programmatic efforts to reduce micronutrient deficiencies, to advance the global nutrition agenda, and to achieve the Millennium Development Goals (MDGs). However, there remains an unmet need to invest in gathering frequent, nationally representative, high-quality micronutrient data as we renew our efforts to scale up nutrition, and as we enter the post-2015 development agenda. Funding Preparation of this manuscript was funded by Sight and Life. There was no funding involved in the study design, data collection, analysis, or decision to publish. PMID:26673631

  18. Hidden ion population: Revisited

    International Nuclear Information System (INIS)

    Olsen, R.C.; Chappell, C.R.; Gallagher, D.L.; Green, J.L.; Gurnett, D.A.

    1985-01-01

    Satellite potentials in the outer plasmasphere range from near zero to +5 to +10 V. Under such conditions ion measurements may not include the low energy core of the plasma population. In eclipse, the photoelectron current drops to zero, and the spacecraft potential can drop to near zero volts. In regions where the ambient plasma density is below 100 cm -3 , previously unobserved portions of the ambient plasma distribution function can become visible in eclipse. A survey of the data obtained from the retarding ion mass spectrometer (RIMS) on Dynamics Explorer 1 shows that the RIMS detector generally measured the isotropic background in both sunlight and eclipse in the plasma-sphere. Absolute density measurements for the ''hidden'' ion population are obtained for the first time using the plasma wave instrument observations of the upper hybrid resonance. Agreement in total density is found in sunlight and eclipse measurements at densities above 80 cm -3 . In eclipse, agreement is found at densities as low as 20 cm -3 . The isotropic plasma composition is primarily H + , with approx.10% He + , and 0.1 to 1.0% O + . A low energy field-aligned ion population appears in eclipse measurements outside the plasmasphere, which is obscured in sunlight. These field-aligned ions can be interpreted as field-aligned flows with densities of a few particles per cubic centimeter, flowing at 5-20 km/s. The problem in measuring these field-aligned flows in sunlight is the masking of the high energy tail of the field-aligned distribution by the isotropic background. Effective measurement of the core of the magnetospheric plasma distribution awaits satellites with active means of controlling the satellite potential

  19. The Spitzer survey of interstellar clouds in the Gould Belt. III. A multi-wavelength view of Corona Australis

    DEFF Research Database (Denmark)

    Peterson, Dawn E.; Caratti o Garatti, Alessio; Bourke, Tyler L.

    2011-01-01

    retrieved from the literature are also added to the list, and a total of 116 candidate YSOs in CrA are compiled. Based on these YSO candidates, the star formation rate is computed to be 12 M sun Myr-1, similar to that of the Lupus clouds. A clustering analysis was also performed, finding that the main....... Using the Spitzer data, we identify 51 young stellar objects (YSOs) in CrA which include sources in the well-studied Coronet cluster as well as sources distributed throughout the molecular cloud. Twelve of the YSOs discussed are new candidates, one of which is located in the Coronet. Known YSOs...

  20. SHARC-II Mapping of Spitzer c2d Small Clouds and Cores

    Science.gov (United States)

    Wu, Jingwen; Dunham, Michael M.; Evans, Neal J., II; Bourke, Tyler L.; Young, Chadwick H.

    2007-04-01

    We present the results of a submillimeter survey of 53 low-mass dense cores with the Submillimeter High Angular Resolution Camera II (SHARC-II). The survey is a follow-up project to the Spitzer Legacy Program "From Molecular Cores to Planet-Forming Disks," with the purpose of creating a complete data set of nearby low-mass dense cores from the infrared to the millimeter. We present maps of 52 cores at 350 μm and three cores at 450 μm, two of which were observed at both wavelengths. Of these 52 cores, 41 were detected by SHARC-II; 32 contained one submillimeter source, while 9 contained multiple sources. For each submillimeter source detected, we report various source properties including source position, fluxes in various apertures, size, aspect ratio, and position angle. For the 12 cores that were not detected we present upper limits. The sources detected by SHARC-II have, on average, smaller sizes at the 2 σ contours than those derived from longer wavelength bolometer observations. We conclude that this is not caused by a failure to integrate long enough to detect the full extent of the core; instead it arises primarily from the fact that the observations presented in this survey are insensitive to smoothly varying extended emission. We find that SHARC-II observations of low-mass cores are much better suited to distinguishing between starless and protostellar cores than observations at longer wavelengths. Very low luminosity objects, a new class of objects being discovered by the Spitzer Space Telescope in cores previously classified as starless, look very similar at 350 μm to other cores with more luminous protostars.

  1. Spitzer Observations of MAMBO Galaxies: Weeding Out Active Nuclei in Starbursting Protoellipticals

    Science.gov (United States)

    Ivison, R. J.; Greve, T. R.; Serjeant, S.; Bertoldi, F.; Egami, E.; Mortier, A. M. J.; Alonso-Herrero, A.; Barmby, P.; Bei, L.; Dole, H.; Engelbracht, C. W.; Fazio, G. G.; Frayer, D. T.; Gordon, K. D.; Hines, D. C.; Huang, J.-S.; Le Floc'h, E.; Misselt, K. A.; Miyazaki, S.; Morrison, J. E.; Papovich, C.; Pérez-González, P. G.; Rieke, M. J.; Rieke, G. H.; Rigby, J.; Rigopoulou, D.; Smail, I.; Wilson, G.; Willner, S. P.

    2004-09-01

    We present 3.6-24 μm Spitzer observations of an unbiased sample of nine luminous, dusty galaxies selected at 1200 μm by MAMBO on the IRAM 30 m telescope, a population akin to the well-known submillimeter or SCUBA galaxies (hereafter SMGs). Owing to the coarse resolution of submillimeter/millimeter cameras, SMGs have traditionally been difficult to identify at other wavelengths. We compare our multiwavelength catalogs to show that the overlap between 24 and 1200 μm must be close to complete at these flux levels. We find that all (4/4) of the most secure >=4 σ SMGs have >=4 σ counterparts at 1.4 GHz, while the fraction drops to 7/9 using all >=3 σ SMGs. We show that combining mid-infrared (MIR) and marginal (>=3 σ) radio detections provides plausible identifications in the remaining cases, enabling us to identify the complete sample. Accretion onto an obscured central engine is betrayed by the shape of the MIR continuum emission for several sources, confirming Spitzer's potential to weed out active galaxies. We demonstrate the power of an S24μm/S8μm versus S8μm/S4.5μm color-color plot as a diagnostic for this purpose. However, we conclude that the majority (~75%) of SMGs have rest-frame mid/far-IR spectral energy distributions commensurate with obscured starbursts. Sensitive 24 μm observations are clearly a useful route to identify and characterize reliable counterparts to high-redshift far-IR-bright galaxies, complementing what is possible via deep radio imaging.

  2. Stargate of the Hidden Multiverse

    Directory of Open Access Journals (Sweden)

    Alexander Antonov

    2016-02-01

    Full Text Available Concept of Monoverse, which corresponds to the existing broad interpretation of the second postulate of the special theory of relativity, is not consistent with the modern astrophysical reality — existence of the dark matter and the dark energy, the total mass-energy of which is ten times greater than the mass-energy of the visible universe (which has been considered as the entire universe until very recent . This concept does not allow to explain their rather unusual properties — invisibility and lack of baryon content — which would seem to even destroy the very modern understanding of the term ‘matter’. However, all numerous alternative concepts of Multiverses, which have been proposed until today, are unable to explain these properties of the dark matter and dark energy. This article describes a new concept: the concept of the hidden Multiverse and hidden Supermultiverse, which mutual invisibility of parallel universes is explained by the physical reality of imaginary numbers. This concept completely explains the phenomenon of the dark matter and the dark energy. Moreover, it is shown that the dark matter and the dark energy are the experimental evidence for the existence of the hidden Multiverse. Described structure of the hidden Multiverse is fully consistent with the data obtained by the space stations WMAP and Planck. An extremely important property of the hidden Multiverse is an actual possibility of its permeation through stargate located on the Earth.

  3. Teaching Vocabulary By Using Hidden Mysteries Game

    OpenAIRE

    Simamora, Ignasius John; Bunau, Eusabinus; Arifin, Zainal

    2014-01-01

    The researcher tried to find whether teaching vocabulary mastery through Hidden Mysteries Game can improve students' vocabulary mastery. Furthermore, this research was designed in the form of pre-experimental research. The data of this research were obtained by doing Pretest and Post-test assessment. The data analysis indicated that the mean score of the students' pre-test was 55.48 (below passing grade 65.00) while the mean score of the students' post-test was 70 (above passing grade 65.00)....

  4. Uncovering the Hidden Costs of Offshoring

    DEFF Research Database (Denmark)

    Larsen, Marcus M.; Manning, Stephan; Pedersen, Torben

    2013-01-01

    This study investigates estimation errors due to hidden costs—the costs of implementation that are neglected in strategic decision-making processes—in the context of services offshoring. Based on data from the Offshoring Research Network, we find that decision makers are more likely to make cost......-estimation errors given increasing configuration and task complexity in captive offshoring and offshore outsourcing, respectively. Moreover, we show that experience and a strong orientation toward organizational design in the offshoring strategy reduce the cost-estimation errors that follow from complexity. Our...

  5. Genetic Algorithms Principles Towards Hidden Markov Model

    Directory of Open Access Journals (Sweden)

    Nabil M. Hewahi

    2011-10-01

    Full Text Available In this paper we propose a general approach based on Genetic Algorithms (GAs to evolve Hidden Markov Models (HMM. The problem appears when experts assign probability values for HMM, they use only some limited inputs. The assigned probability values might not be accurate to serve in other cases related to the same domain. We introduce an approach based on GAs to find
    out the suitable probability values for the HMM to be mostly correct in more cases than what have been used to assign the probability values.

  6. Unusual Slowly Rotating Brown Dwarfs Discovered through Precision Spitzer Photometry

    Science.gov (United States)

    Heinze, Aren; Metchev, S.

    2014-01-01

    Many brown dwarfs exhibit low-amplitude rotationally modulated variability due to photospheric inhomogeneities caused by condensate clouds in their atmospheres. The Spitzer Space Telescope 'Weather on Other Worlds' (WoW) project has monitored 44 brown dwarfs at unprecedented photometric precision from space. We present one of several important new results from WoW: the discovery of brown dwarfs with unexpectedly slow rotation periods. While most brown dwarfs have periods of 2-12 hours, we have identified two with well-constrained periods of 13±1 and >20 hours, respectively, and 2 others that show more tentative evidence of longer than 20-hour periods. By serving as almost non-rotating standards, these objects will allow more accurate calibration of spectroscopic measurements of brown dwarfs' projected rotational velocities. The existence of such slowly-rotating objects also constrains models of brown dwarf formation and angular momentum evolution.

  7. Polycyclic Aromatic Hydrocarbons and Infrared Astrophysics with Spitzer

    Science.gov (United States)

    Hudgins, Douglas M.; Allamandola, L. J.

    2004-01-01

    Over the past fifteen years, thanks to significant, parallel advancements in observational, experimental, and theoretical techniques, tremendous strides have been made in our understanding of the role that carbon-rich plays in the interstellar medium (ISM). Twenty years ago, the possible existence of an abundant population of large, carbon-rich molecules in the ISM was unthinkable. Today, the unmistakable spectroscopic signatures of polycyclic aromatic hydrocarbons (PAHs) - shockingly large molecules by the standards of traditional interstellar chemistry -are recognized throughout the Universe. In this presentation, we will examine the current state of the interstellar PAH model and explore how this data, in conjunction with the unparalleled observational data provided by the Spitzer Space Telescope, can be used to draw ever-deeper insights into the physical and chemical natures of a wide range of astrophysical environments.

  8. Hidden worlds in quantum physics

    CERN Document Server

    Gouesbet, Gérard

    2014-01-01

    The past decade has witnessed a resurgence in research and interest in the areas of quantum computation and entanglement. This new book addresses the hidden worlds or variables of quantum physics. Author Gérard Gouesbet studied and worked with a former student of Louis de Broglie, a pioneer of quantum physics. His presentation emphasizes the history and philosophical foundations of physics, areas that will interest lay readers as well as professionals and advanced undergraduate and graduate students of quantum physics. The introduction is succeeded by chapters offering background on relevant concepts in classical and quantum mechanics, a brief history of causal theories, and examinations of the double solution, pilot wave, and other hidden-variables theories. Additional topics include proofs of possibility and impossibility, contextuality, non-locality, classification of hidden-variables theories, and stochastic quantum mechanics. The final section discusses how to gain a genuine understanding of quantum mec...

  9. Hidden Crises and Communication: An Interactional Analysis of Hidden Crises

    NARCIS (Netherlands)

    dr. Annette Klarenbeek

    2011-01-01

    In this paper I describe the ways in which the communication discipline can make a hidden crisis transparent. For this purpose I examine the concept of crisis entrepreneurship from a communication point of view. Using discourse analysis, I analyse the discursive practices of crisis entrepreneurs in

  10. Hidden Crises and Communication : An Interactional Analysis of Hidden Crises

    NARCIS (Netherlands)

    dr. Annette Klarenbeek

    2011-01-01

    In this paper I describe the ways in which the communication discipline can make a hidden crisis transparent. For this purpose I examine the concept of crisis entrepreneurship from a communication point of view. Using discourse analysis, I analyse the discursive practices of crisis entrepreneurs in

  11. Needs of the hidden homeless - no longer hidden: a pilot study.

    Science.gov (United States)

    Crawley, J; Kane, D; Atkinson-Plato, L; Hamilton, M; Dobson, K; Watson, J

    2013-07-01

    The purpose of this pilot study was to describe the health, housing and social service needs of the hidden homeless. It has been estimated that 80% of all people experiencing homelessness are hidden homeless, and because they remain 'hidden', resources are not allocated to provide this vulnerable population with support. This was a descriptive, case series research design. Participants were recruited through agency referral and snowball sampling. Research ethics board (REB) approval was granted. Using descriptive statistics, information obtained from participant surveys was analysed using SPSS version 19. Thirty-four participants met the inclusion criteria and ranged from 15 to 69 years. Fifty percent of the participants reported first being homeless between 14 and 18 years of age. Participants had several comorbidities, including mental health challenges, dental and respiratory problems, and sleep disorders. Participants described several challenges with accessing adequate nutrition, and finding adequate transportation and finances, and did not list housing as a priority need. The most frequent barriers to accessing health and social services identified by participants included their personal challenges with addiction, lack of transportation, and the perceived stigma they experienced when they sought help from health and social service agencies. Findings from this study can contribute to the development of best practice guidelines and policies that specifically address the needs of this unique population. Improved allocation of resources and coordination of health and community services are cost-effective, and advance the overall health of the hidden homeless. Copyright © 2013 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  12. The optical spectra of 24 mu m galaxies in the cosmos field. I. Spitzer MIPS bright sources in the zCOSMOS-bright 10k catalog

    NARCIS (Netherlands)

    Caputi, K. I.; Lilly, S. J.; Aussel, H.; Sanders, D.; Frayer, D.; Le Fevre, O.; Renzini, A.; Zamorani, G.; Scodeggio, M.; Contini, T.; Scoville, N.; Carollo, C. M.; Hasinger, G.; Iovino, A.; Le Brun, V.; Le Floc'h, E.; Maier, C.; Mainieri, V.; Mignoli, M.; Salvato, M.; Schiminovich, D.; Silverman, J.; Surace, J.; Tasca, L.; Abbas, U.; Bardelli, S.; Bolzonella, M.; Bongiorno, A.; Bottini, D.; Capak, P.; Cappi, A.; Cassata, P.; Cimatti, A.; Cucciati, O.; de la Torre, S.; de Ravel, L.; Franzetti, P.; Fumana, M.; Garilli, B.; Halliday, C.; Ilbert, O.; Kampczyk, P.; Kartaltepe, J.; Kneib, J. -P.; Knobel, C.; Kovac, K.; Lamareille, F.; Leauthaud, A.; Le Borgne, J. F.; Maccagni, D.; Marinoni, C.; McCracken, H.; Meneux, B.; Oesch, P.; Pello, R.; Perez-Montero, E.; Porciani, C.; Ricciardelli, E.; Scaramella, R.; Scarlata, C.; Tresse, L.; Vergani, D.; Walcher, J.; Zamojski, M.; Zucca, E.

    2008-01-01

    We study zCOSMOS-bright optical spectra for 609 Spitzer MIPS 24 mu m-selected galaxies with S-24 (mu m) > 0: 30 mJy and I <22.5 (AB mag) over 1.5 deg(2) of the COSMOS field. From emission-line diagnostics we find the following: (1) SFRs derived from the observed H alpha lambda 6563 and H beta lambda

  13. LOW FALSE POSITIVE RATE OF KEPLER CANDIDATES ESTIMATED FROM A COMBINATION OF SPITZER AND FOLLOW-UP OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Désert, Jean-Michel; Brown, Timothy M. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Charbonneau, David; Torres, Guillermo; Fressin, François; Ballard, Sarah; Latham, David W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bryson, Stephen T.; Borucki, William J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Knutson, Heather A. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Batalha, Natalie M. [San Jose State University, San Jose, CA 95192 (United States); Deming, Drake [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Ford, Eric B. [University of Florida, Gainesville, FL 32611 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Gilliland, Ronald L. [Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802 (United States); Seager, Sara, E-mail: desert@colorado.edu [Massachusetts Institute of Technology, Cambridge, MA 02159 (United States)

    2015-05-01

    NASA’s Kepler mission has provided several thousand transiting planet candidates during the 4 yr of its nominal mission, yet only a small subset of these candidates have been confirmed as true planets. Therefore, the most fundamental question about these candidates is the fraction of bona fide planets. Estimating the rate of false positives of the overall Kepler sample is necessary to derive the planet occurrence rate. We present the results from two large observational campaigns that were conducted with the Spitzer Space Telescope during the the Kepler mission. These observations are dedicated to estimating the false positive rate (FPR) among the Kepler candidates. We select a sub-sample of 51 candidates, spanning wide ranges in stellar, orbital, and planetary parameter space, and we observe their transits with Spitzer at 4.5 μm. We use these observations to measures the candidate’s transit depths and infrared magnitudes. An authentic planet produces an achromatic transit depth (neglecting the modest effect of limb darkening). Conversely a bandpass-dependent depth alerts us to the potential presence of a blending star that could be the source of the observed eclipse: a false positive scenario. For most of the candidates (85%), the transit depths measured with Kepler are consistent with the transit depths measured with Spitzer as expected for planetary objects, while we find that the most discrepant measurements are due to the presence of unresolved stars that dilute the photometry. The Spitzer constraints on their own yield FPRs between 5% and depending on the Kepler Objects of Interest. By considering the population of the Kepler field stars, and by combining follow-up observations (imaging) when available, we find that the overall FPR of our sample is low. The measured upper limit on the FPR of our sample is 8.8% at a confidence level of 3σ. This observational result, which uses the achromatic property of planetary transit signals that is not investigated

  14. Hidden Markov Model Application to Transfer The Trader Online Forex Brokers

    Directory of Open Access Journals (Sweden)

    Farida Suharleni

    2012-05-01

    Full Text Available Hidden Markov Model is elaboration of Markov chain, which is applicable to cases that can’t directly observe. In this research, Hidden Markov Model is used to know trader’s transition to broker forex online. In Hidden Markov Model, observed state is observable part and hidden state is hidden part. Hidden Markov Model allows modeling system that contains interrelated observed state and hidden state. As observed state in trader’s transition to broker forex online is category 1, category 2, category 3, category 4, category 5 by condition of every broker forex online, whereas as hidden state is broker forex online Marketiva, Masterforex, Instaforex, FBS and Others. First step on application of Hidden Markov Model in this research is making construction model by making a probability of transition matrix (A from every broker forex online. Next step is making a probability of observation matrix (B by making conditional probability of five categories, that is category 1, category 2, category 3, category 4, category 5 by condition of every broker forex online and also need to determine an initial state probability (π from every broker forex online. The last step is using Viterbi algorithm to find hidden state sequences that is broker forex online sequences which is the most possible based on model and observed state that is the five categories. Application of Hidden Markov Model is done by making program with Viterbi algorithm using Delphi 7.0 software with observed state based on simulation data. Example: By the number of observation T = 5 and observed state sequences O = (2,4,3,5,1 is found hidden state sequences which the most possible with observed state O as following : where X1 = FBS, X2 = Masterforex, X3 = Marketiva, X4 = Others, and X5 = Instaforex.

  15. LUMINOSITY FUNCTIONS OF SPITZER-IDENTIFIED PROTOSTARS IN NINE NEARBY MOLECULAR CLOUDS

    International Nuclear Information System (INIS)

    Kryukova, E.; Megeath, S. T.; Allen, T. S.; Gutermuth, R. A.; Pipher, J.; Allen, L. E.; Myers, P. C.; Muzerolle, J.

    2012-01-01

    We identify protostars in Spitzer surveys of nine star-forming (SF) molecular clouds within 1 kpc: Serpens, Perseus, Ophiuchus, Chamaeleon, Lupus, Taurus, Orion, Cep OB3, and Mon R2, which combined host over 700 protostar candidates. These clouds encompass a variety of SF environments, including both low-mass and high-mass SF regions, as well as dense clusters and regions of sparsely distributed star formation. Our diverse cloud sample allows us to compare protostar luminosity functions in these varied environments. We combine near- and mid-infrared photometry from the Two Micron All Sky Survey and Spitzer to create 1-24 μm spectral energy distributions (SEDs). Using protostars from the c2d survey with well-determined bolometric luminosities, we derive a relationship between bolometric luminosity, mid-IR luminosity (integrated from 1-24 μm), and SED slope. Estimations of the bolometric luminosities for protostar candidates are combined to create luminosity functions for each cloud. Contamination due to edge-on disks, reddened Class II sources, and galaxies is estimated and removed from the luminosity functions. We find that luminosity functions for high-mass SF clouds (Orion, Mon R2, and Cep OB3) peak near 1 L ☉ and show a tail extending toward luminosities above 100 L ☉ . The luminosity functions of the low-mass SF clouds (Serpens, Perseus, Ophiuchus, Taurus, Lupus, and Chamaeleon) do not exhibit a common peak, however the combined luminosity function of these regions peaks below 1 L ☉ . Finally, we examine the luminosity functions as a function of the local surface density of young stellar objects. In the Orion molecular clouds, we find a significant difference between the luminosity functions of protostars in regions of high and low stellar density, the former of which is biased toward more luminous sources. This may be the result of primordial mass segregation, although this interpretation is not unique. We compare our luminosity functions to those

  16. LUMINOSITY FUNCTIONS OF SPITZER-IDENTIFIED PROTOSTARS IN NINE NEARBY MOLECULAR CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Kryukova, E.; Megeath, S. T.; Allen, T. S. [Department of Physics and Astronomy, University of Toledo, Toledo, OH (United States); Gutermuth, R. A. [Department of Astronomy, University of Massachusetts, Amherst, MA (United States); Pipher, J. [Department of Physics and Astronomy, University of Rochester, Rochester, NY (United States); Allen, L. E. [National Optical Astronomy Observatories, Tucson, AZ (United States); Myers, P. C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Muzerolle, J. [Space Telescope Science Institute, Baltimore, MD (United States)

    2012-08-15

    We identify protostars in Spitzer surveys of nine star-forming (SF) molecular clouds within 1 kpc: Serpens, Perseus, Ophiuchus, Chamaeleon, Lupus, Taurus, Orion, Cep OB3, and Mon R2, which combined host over 700 protostar candidates. These clouds encompass a variety of SF environments, including both low-mass and high-mass SF regions, as well as dense clusters and regions of sparsely distributed star formation. Our diverse cloud sample allows us to compare protostar luminosity functions in these varied environments. We combine near- and mid-infrared photometry from the Two Micron All Sky Survey and Spitzer to create 1-24 {mu}m spectral energy distributions (SEDs). Using protostars from the c2d survey with well-determined bolometric luminosities, we derive a relationship between bolometric luminosity, mid-IR luminosity (integrated from 1-24 {mu}m), and SED slope. Estimations of the bolometric luminosities for protostar candidates are combined to create luminosity functions for each cloud. Contamination due to edge-on disks, reddened Class II sources, and galaxies is estimated and removed from the luminosity functions. We find that luminosity functions for high-mass SF clouds (Orion, Mon R2, and Cep OB3) peak near 1 L{sub Sun} and show a tail extending toward luminosities above 100 L{sub Sun }. The luminosity functions of the low-mass SF clouds (Serpens, Perseus, Ophiuchus, Taurus, Lupus, and Chamaeleon) do not exhibit a common peak, however the combined luminosity function of these regions peaks below 1 L{sub Sun }. Finally, we examine the luminosity functions as a function of the local surface density of young stellar objects. In the Orion molecular clouds, we find a significant difference between the luminosity functions of protostars in regions of high and low stellar density, the former of which is biased toward more luminous sources. This may be the result of primordial mass segregation, although this interpretation is not unique. We compare our luminosity

  17. Hidden Markov Model for Stock Selection

    Directory of Open Access Journals (Sweden)

    Nguyet Nguyen

    2015-10-01

    Full Text Available The hidden Markov model (HMM is typically used to predict the hidden regimes of observation data. Therefore, this model finds applications in many different areas, such as speech recognition systems, computational molecular biology and financial market predictions. In this paper, we use HMM for stock selection. We first use HMM to make monthly regime predictions for the four macroeconomic variables: inflation (consumer price index (CPI, industrial production index (INDPRO, stock market index (S&P 500 and market volatility (VIX. At the end of each month, we calibrate HMM’s parameters for each of these economic variables and predict its regimes for the next month. We then look back into historical data to find the time periods for which the four variables had similar regimes with the forecasted regimes. Within those similar periods, we analyze all of the S&P 500 stocks to identify which stock characteristics have been well rewarded during the time periods and assign scores and corresponding weights for each of the stock characteristics. A composite score of each stock is calculated based on the scores and weights of its features. Based on this algorithm, we choose the 50 top ranking stocks to buy. We compare the performances of the portfolio with the benchmark index, S&P 500. With an initial investment of $100 in December 1999, over 15 years, in December 2014, our portfolio had an average gain per annum of 14.9% versus 2.3% for the S&P 500.

  18. Sexual Harrassment: A Hidden Problem.

    Science.gov (United States)

    Sandler, Bernice R.; And Others

    1981-01-01

    The hidden but serious problem of sexual harassment of students and employees by college faculty is discussed, some statistics are given, and legal and court opinions outlined. Harassment as a violation of Title IX is analyzed, and implications for institutional action to curb it are outlined. (MSE)

  19. Adaptive Partially Hidden Markov Models

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto; Rasmussen, Tage

    1996-01-01

    Partially Hidden Markov Models (PHMM) have recently been introduced. The transition and emission probabilities are conditioned on the past. In this report, the PHMM is extended with a multiple token version. The different versions of the PHMM are applied to bi-level image coding....

  20. Hidden symmetry of the quantum Calogero-Moser system

    DEFF Research Database (Denmark)

    Kuzentsov, Vadim b

    1996-01-01

    The hidden symmetry of the quantum Calogero-Moser system with an inverse-square potential is algebraically demonstrated making use of Dunkl's operators. We find the underlying algebra explaining the super-integrability phenomenon for this system. Applications to related multi-variable Bessel...... functions are also discussed....

  1. SPITZER OBSERVATIONS OF LONG-TERM INFRARED VARIABILITY AMONG YOUNG STELLAR OBJECTS IN CHAMAELEON I

    Energy Technology Data Exchange (ETDEWEB)

    Flaherty, Kevin M.; Herbst, William [Van Vleck Observatory, Astronomy Department, Wesleyan University, 96 Foss Hill Drive, Middletown, CT 06459 (United States); DeMarchi, Lindsay [Department of Physics and Astronomy, Colgate University, 13 Oak Drive, Hamilton, NY 13346 (United States); Muzerolle, James [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Balog, Zoltan [Max-Planck-Institut fur Astronomie, Konigstuhl 17, D-69117 Heidelberg (Germany); Megeath, S. Thomas [Ritter Astrophysical Research Center, Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States); Furlan, Elise [Infrared Processing and Analysis Center, California Institute of Technology, 770 S. Wilson Avenue, Pasadena, CA 91125 (United States); Gutermuth, Robert [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

    2016-12-10

    Infrared variability is common among young stellar objects, with surveys finding daily to weekly fluctuations of a few tenths of a magnitude. Space-based observations can produce highly sampled infrared light curves, but are often limited to total baselines of about 1 month due to the orientation of the spacecraft. Here we present observations of the Chameleon I cluster, whose low declination makes it observable by the Spitzer Space Telescope over a 200-day period. We observe 30 young stellar objects with a daily cadence to better sample variability on timescales of months. We find that such variability is common, occurring in ∼80% of the detected cluster members. The change in [3.6]–[4.5] color over 200 days for many of the sources falls between that expected for extinction and fluctuations in disk emission. With our high cadence and long baseline we can derive power spectral density curves covering two orders of magnitude in frequency and find significant power at low frequencies, up to the boundaries of our 200-day survey. Such long timescales are difficult to explain with variations driven by the interaction between the disk and stellar magnetic field, which has a dynamical timescale of days to weeks. The most likely explanation is either structural or temperature fluctuations spread throughout the inner ∼0.5 au of the disk, suggesting that the intrinsic dust structure is highly dynamic.

  2. THE LAST GASP OF GAS GIANT PLANET FORMATION: A SPITZER STUDY OF THE 5 Myr OLD CLUSTER NGC 2362

    International Nuclear Information System (INIS)

    Currie, Thayne; Lada, Charles J.; Robitaille, Thomas P.; Irwin, Jonathan; Kenyon, Scott J.; Plavchan, Peter

    2009-01-01

    Expanding upon the Infrared Array Camera (IRAC) survey from Dahm and Hillenbrand, we describe Spitzer IRAC and Multiband Imaging Photometer for Spitzer observations of the populous, 5 Myr old open cluster NGC 2362. We analyze the mid-IR colors of cluster members and compared their spectral energy distributions (SEDs) to star+circumstellar disk models to constrain the disk morphologies and evolutionary states. Early/intermediate-type confirmed/candidate cluster members either have photospheric mid-IR emission or weak, optically thin IR excess emission at λ ≥ 24 μm consistent with debris disks. Few late-type, solar/subsolar-mass stars have primordial disks. The disk population around late-type stars is dominated by disks with inner holes (canonical 'transition disks') and 'homologously depleted' disks. Both types of disks represent an intermediate stage between primordial disks and debris disks. Thus, in agreement with previous results, we find that multiple paths for the primordial-to-debris disk transition exist. Because these 'evolved primordial disks' greatly outnumber primordial disks, our results undermine standard arguments in favor of a ∼ 5 yr timescale for the transition based on data from Taurus-Auriga. Because the typical transition timescale is far longer than 10 5 yr, these data also appear to rule out standard ultraviolet photoevaporation scenarios as the primary mechanism to explain the transition. Combining our data with other Spitzer surveys, we investigate the evolution of debris disks around high/intermediate-mass stars and investigate timescales for giant planet formation. Consistent with Currie et al., the luminosity of 24 μm emission in debris disks due to planet formation peaks at ∼10-20 Myr. If the gas and dust in disks evolve on similar timescales, the formation timescale for gas giant planets surrounding early-type, high/intermediate-mass (∼>1.4 M sun ) stars is likely 1-5 Myr. Most solar/subsolar-mass stars detected by Spitzer

  3. VizieR Online Data Catalog: Spitzer photometric time series of HD 97658 (Van Grootel+, 2014)

    Science.gov (United States)

    Van Grootel, V.; Gillon, M.; Valencia, D.; Madhusudhan, N.; Dragomir, D.; Howe, A. R.; Burrows, A. S.; Demory, B.-O.; Deming, D.; Ehrenreich, D.; Lovis, C.; Mayor, M.; Pepe, F.; Queloz, D.; Scuflaire, R.; Seager, S.; Segransan, D.; Udry, S.

    2017-07-01

    We monitored HD 97658 with Spitzer's IRAC camera on 2013 August 10 from 13:01:00 to 18:27:00 UT, corresponding to a transit window as computed from the MOST transit ephemeris (Dragomir et al. 2013, J/ApJ/772/L2). These Spitzer data were acquired in the context of the Cycle 9 program 90072 (PI: M. Gillon) dedicated to the search for the transits of RV-detected low-mass planets. They consist of 2320 sets of 64 individual subarray images obtained at 4.5 μm with an integration time of 0.08 s. They are available on the Spitzer Heritage Archive database under the form of 2320 Basic Calibrated Data files calibrated by the standard Spitzer reduction pipeline (version S19.1.0). (1 data file).

  4. QCD sum rule study of hidden-charm pentaquarks

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hua-Xing; Cui, Er-Liang [Beihang University, School of Physics and Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beijing (China); Chen, Wei; Steele, T.G. [University of Saskatchewan, Department of Physics and Engineering Physics, Saskatoon, Saskatchewan (Canada); Liu, Xiang [Lanzhou University, School of Physical Science and Technology, Lanzhou (China); Lanzhou University and Institute of Modern Physics of CAS, Research Center for Hadron and CSR Physics, Lanzhou (China); Zhu, Shi-Lin [Peking University, School of Physics and State Key Laboratory of Nuclear Physics and Technology, Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Peking University, Center of High Energy Physics, Beijing (China)

    2016-10-15

    We study the mass spectra of hidden-charm pentaquarks having spin J = (1)/(2)/(3)/(2)/(5)/(2) and quark contents uudc anti c. We systematically construct all the relevant local hidden-charm pentaquark currents, and we select some of them to perform QCD sum rule analyses. We find that the P{sub c}(4380) and P{sub c}(4450) can be identified as hidden-charm pentaquark states composed of an anti-charmed meson and a charmed baryon. Besides them, we also find (a) the lowest-lying hidden-charm pentaquark state of J{sup P} = 1/2{sup -} has the mass 4.33{sup +0.17}{sub -0.13} GeV, while the one of J{sup P} = 1/2{sup +} is significantly higher, that is, around 4.7-4.9 GeV; (b) the lowest-lying hidden-charm pentaquark state of J{sup P} = 3/2{sup -} has the mass 4.37{sup +0.18}{sub -0.13} GeV, consistent with the P{sub c}(4380) of J{sup P} = 3/2{sup -}, while the one of J{sup P} = 3/2{sup +} is also significantly higher, that is, above 4.6 GeV; (c) the hidden-charm pentaquark state of J{sup P} = 5/2{sup -} has a mass around 4.5-4.6 GeV, slightly larger than the P{sub c}(4450) of J{sup P} = 5/2{sup +}. (orig.)

  5. The hidden research paper.

    Science.gov (United States)

    Horton, Richard

    2002-06-05

    To determine whether the views expressed in a research paper are accurate representations of contributors' opinions about the research being reported. Purposive sampling of 10 research articles published in The Lancet; qualitative analysis of answers to 6 questions about the meaning of the study put to contributors who were listed on the byline of these articles. Fifty-four contributors listed on the bylines of the 10 articles were evaluated, and answers to questions were compared between contributors within research groups and against the published research report. A total of 36 (67%) of 54 contributors replied to this survey. Important weaknesses were often admitted on direct questioning but were not included in the published article. Contributors frequently disagreed about the importance of their findings, implications, and directions for future research. I could find no effort to study systematically past evidence relating to the investigators' own findings in either survey responses or the published article. Overall, the diversity of contributor opinion was commonly excluded from the published report. I found that discussion sections were haphazardly organized and did not deal systematically with important questions about the study. A research paper rarely represents the opinions of those scientists whose work it reports. The findings described herein reveal evidence of (self-)censored criticism, obscured meanings, confused assessment of implications, and failures to indicate directions for future research. There is now empirical support for the introduction of structured discussion sections in research papers. Editors might also explore ways to recover the plurality of contributors' opinions.

  6. Planck, Herschel & Spitzer unveil overdense z>2 regions

    Science.gov (United States)

    Dole, Herve; Chary, Ranga-Ram; Chary, Ranga; Frye, Brenda; Martinache, Clement; Guery, David; Le Floc'h, Emeric; Altieri, Bruno; Flores-Cacho, Ines; Giard, Martin; Hurier, Guillaume; Lagache, Guilaine; Montier, Ludovic; Nesvadba, Nicole; Omont, Alain; Pointecouteau, Etienne; Pierini, Daniele; Puget, Jean-Loup; Scott, Douglas; Soucail, Genevieve

    2014-12-01

    At which cosmic epoch did massive galaxy clusters assemble their baryons? How does star formation occur in the most massive, most rapidly collapsing dark-matter-dense environments in the early Universe? To answer these questions, we take the completely novel approach to select the most extreme z>~2 star-forming overdensities seen over the entire sky. This selection nicely complements the other existing selections for high redshift clusters (i.e., by stellar mass, or by total mass like Sunyaev-Zeldovish (SZ) or X-ray selection). We make use of the Planck all-sky submillimetre survey to systematically identify the rarest, most luminous high-redshift sub-mm sources on the sky, either strongly gravitationally lensed galaxies, or the joint FIR/sub-mm emission from multiple intense starbursts. We observed 228 Planck sources with Herschel/SPIRE and discovered that most of them are overdensities of red galaxies with extremely high star formation rates (typically 7.e3 Msun/yr for a structure). Only Spitzer data can allow a better understanding of these promising Planck+Herschel selected sources, as is shown on a first set of IRAC data on 40 targets in GO9: (i) the good angular resolution and sensitivity of IRAC allows a proper determination of the clustered nature of each Herschel/SPIRE source; (ii) IRAC photometry (often associated with J, K) allows a good estimate of the colors and approximate photometric redshift. Note spectroscopic redshifts are available for two cluster candidates, at z=1.7 and z=2.3, confirming their high redshift nature. The successful GO9 observation of 40 fields showed that about half to be >7sigma overdensities of red IRAC sources. These observations were targeting the whole range of Herschel overdensities and significances. We need to go deeper into the Spitzer sample and acquire complete coverage of the most extreme Herschel overdensities (54 new fields). Such a unique sample has legacy value, and this is the last opportunity prior to JWST

  7. The climate of HD 189733b from fourteen transits and eclipses measured by Spitzer

    Energy Technology Data Exchange (ETDEWEB)

    Agol, E.; /Washington U., Seattle, Astron. Dept. /Santa Barbara, KITP /UC, Santa Barbara; Cowan, Nicolas B.; /Washington U., Seattle, Astron. Dept.; Knutson, Heather A.; /UC, Berkeley, Astron. Dept.; Deming, Drake; /NASA, Goddard; Steffen, Jason H.; /Fermilab; Henry, Gregory W.; /Tennessee State U.; Charbonneau, David; /Harvard-Smithsonian Ctr. Astrophys.

    2010-07-01

    We present observations of six transits and six eclipses of the transiting planet system HD 189733 taken with the Spitzer Space Telescope IRAC camera at 8 microns, as well as a re-analysis of previously published data. We use several novel techniques in our data analysis, the most important of which is a new correction for the detector 'ramp' variation with a double-exponential function which performs better and is a better physical model for this detector variation. Our main scientific findings are: (1) an upper limit on the variability of the day-side planet flux of 2.7% (68% confidence); (2) the most precise set of transit times measured for a transiting planet, with an average accuracy of 3 seconds; (3) a lack of transit-timing variations, excluding the presence of second planets in this system above 20% of the mass of Mars in low-order mean-motion resonance at 95% confidence; (4) a confirmation of the planet's phase variation, finding the night side is 64% as bright as the day side, as well as an upper limit on the night-side variability of 17% (68% confidence); (5) a better correction for stellar variability at 8 micron causing the phase function to peak 3.5 hours before secondary eclipse, confirming that the advection and radiation timescales are comparable at the 8 micron photosphere; (6) variation in the depth of transit, which possibly implies variations in the surface brightness of the portion of the star occulted by the planet, posing a fundamental limit on non-simultaneous multi-wavelength transit absorption measurements of planet atmospheres; (7) a measurement of the infrared limb-darkening of the star, which is in good agreement with stellar atmosphere models; (8) an offset in the times of secondary eclipse of 69 seconds, which is mostly accounted for by a 31 second light travel time delay and 33 second delay due to the shift of ingress and egress by the planet hot spot; this confirms that the phase variation is due to an offset hot

  8. Hidden conformal symmetry of extremal black holes

    International Nuclear Information System (INIS)

    Chen Bin; Long Jiang; Zhang Jiaju

    2010-01-01

    We study the hidden conformal symmetry of extremal black holes. We introduce a new set of conformal coordinates to write the SL(2,R) generators. We find that the Laplacian of the scalar field in many extremal black holes, including Kerr(-Newman), Reissner-Nordstrom, warped AdS 3 , and null warped black holes, could be written in terms of the SL(2,R) quadratic Casimir. This suggests that there exist dual conformal field theory (CFT) descriptions of these black holes. From the conformal coordinates, the temperatures of the dual CFTs could be read directly. For the extremal black hole, the Hawking temperature is vanishing. Correspondingly, only the left (right) temperature of the dual CFT is nonvanishing, and the excitations of the other sector are suppressed. In the probe limit, we compute the scattering amplitudes of the scalar off the extremal black holes and find perfect agreement with the CFT prediction.

  9. SERENDIPITY OBSERVATIONS OF FAR INFRARED CIRRUS EMISSION IN THE SPITZER INFRARED NEARBY GALAXIES SURVEY: ANALYSIS OF FAR-INFRARED CORRELATIONS

    International Nuclear Information System (INIS)

    Bot, Caroline; Helou, George; Boulanger, Francois; Lagache, Guilaine; Miville-Deschenes, Marc-Antoine; Draine, Bruce; Martin, Peter

    2009-01-01

    We present an analysis of far-infrared (FIR) dust emission from diffuse cirrus clouds. This study is based on serendipitous observations at 160 μm at high-galactic latitude with the Multiband Imaging Photometer onboard the Spitzer Space Telescope by the Spitzer Infrared Nearby Galaxies Survey. These observations are complemented with IRIS data at 100 and 60 μm and constitute one of the most sensitive and unbiased samples of FIR observations at a small scale of diffuse interstellar clouds. Outside regions dominated by the cosmic infrared background fluctuations, we observe a substantial scatter in the 160/100 colors from cirrus emission. We compared the 160/100 color variations to 60/100 colors in the same fields and find a trend of decreasing 60/100 with increasing 160/100. This trend cannot be accounted for by current dust models by changing solely the interstellar radiation field. It requires a significant change of dust properties such as grain size distribution or emissivity or a mixing of clouds in different physical conditions along the line of sight. These variations are important as a potential confusing foreground for extragalactic studies.

  10. Probing Large-scale Coherence between Spitzer IR and Chandra X-Ray Source-subtracted Cosmic Backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Cappelluti, N.; Urry, M. [Yale Center for Astronomy and Astrophysics, P.O. Box 208120, New Haven, CT 06520 (United States); Arendt, R. [University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Kashlinsky, A. [Observational Cosmology Laboratory, NASA Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Li, Y.; Hasinger, G. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Helgason, K. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States); Natarajan, P. [Max Planck Institute for Astrophysics, Karl-Schwarzschild-Str. 1, D-85748 Garching (Germany); Finoguenov, A. [Max-Planck-Institut für extraterrestrische Physik, Postfach 1312, D-85741, Garching bei München (Germany)

    2017-09-20

    We present new measurements of the large-scale clustering component of the cross-power spectra of the source-subtracted Spitzer -IRAC cosmic infrared background and Chandra -ACIS cosmic X-ray background surface brightness fluctuations Our investigation uses data from the Chandra Deep Field South, Hubble Deep Field North, Extended Groth Strip/AEGIS field, and UDS/SXDF surveys, comprising 1160 Spitzer hours and ∼12 Ms of Chandra data collected over a total area of 0.3 deg{sup 2}. We report the first (>5 σ ) detection of a cross-power signal on large angular scales >20″ between [0.5–2] keV and the 3.6 and 4.5 μ m bands, at ∼5 σ and 6.3 σ significance, respectively. The correlation with harder X-ray bands is marginally significant. Comparing the new observations with existing models for the contribution of the known unmasked source population at z < 7, we find an excess of about an order of magnitude at 5 σ confidence. We discuss possible interpretations for the origin of this excess in terms of the contribution from accreting early black holes (BHs), including both direct collapse BHs and primordial BHs, as well as from scattering in the interstellar medium and intra-halo light.

  11. Probing Large-scale Coherence between Spitzer IR and Chandra X-Ray Source-subtracted Cosmic Backgrounds

    Science.gov (United States)

    Cappelluti, N.; Arendt, R.; Kashlinsky, A.; Li, Y.; Hasinger, G.; Helgason, K.; Urry, M.; Natarajan, P.; Finoguenov, A.

    2017-09-01

    We present new measurements of the large-scale clustering component of the cross-power spectra of the source-subtracted Spitzer-IRAC cosmic infrared background and Chandra-ACIS cosmic X-ray background surface brightness fluctuations Our investigation uses data from the Chandra Deep Field South, Hubble Deep Field North, Extended Groth Strip/AEGIS field, and UDS/SXDF surveys, comprising 1160 Spitzer hours and ˜12 Ms of Chandra data collected over a total area of 0.3 deg2. We report the first (>5σ) detection of a cross-power signal on large angular scales >20″ between [0.5-2] keV and the 3.6 and 4.5 μm bands, at ˜5σ and 6.3σ significance, respectively. The correlation with harder X-ray bands is marginally significant. Comparing the new observations with existing models for the contribution of the known unmasked source population at z < 7, we find an excess of about an order of magnitude at 5σ confidence. We discuss possible interpretations for the origin of this excess in terms of the contribution from accreting early black holes (BHs), including both direct collapse BHs and primordial BHs, as well as from scattering in the interstellar medium and intra-halo light.

  12. A Search to Uncover the Infrared Excess (IRXS) Sources in the Spitzer Enhanced Imaging Products (SEIP) Catalog

    Science.gov (United States)

    Rowe, Jamie Lynn; Duranko, Gary; Gorjian, Varoujan; Lineberger, Howard; Orr, Laura; Adewole, Ayomikun; Bradford, Eric; Douglas, Alea; Kohl, Steven; Larson, Lillia; Lascola, Gus; Orr, Quinton; Scott, Mekai; Walston, Joseph; Wang, Xian

    2018-01-01

    The Spitzer Enhanced Imaging Products catalog (SEIP) is a collection of nearly 42 million point sources obtained by the Spitzer Space Telescope during its 5+ year cryogenic mission. Strasburger et al (2014) isolated sources with a signal-to-noise ratio (SNR) >10 in five infrared (IR) wavelength channels (3.6, 4.5, 5.8, 8 and 24 microns) to begin a search for sources with infrared excess (IRXS). They found 76 objects that were never catalogued before. Based on this success, we intend to dig deeper into the catalog in an attempt to find more IRXS sources, specifically by lowering the SNR on the 3.6, 4.5, and 24 micron channels. The ultimate goal is to use this large sample to seek rare astrophysical sources that are transitional in nature and evolutionarily very important.Our filtering of the database at SNR > 5 yielded 461,000 sources. This was further evaluated and reduced to only the most interesting based on source location on a [3.6]-[4.5] vs [4.5]-[24] color-color diagram. We chose a sample of 985 extreme IRXS sources for further inspection. All of these candidate sources were visually inspected and cross-referenced against known sources in existing databases, resulting in a list of highly reliable IRXS sources.These sources will prove important in the study of galaxy and stellar evolution, and will serve as a starting point for further investigation.

  13. Spitzer identification of potentially active Near-Earth Asteroids

    Science.gov (United States)

    Mommert, Michael; Trilling, David; Hora, Joseph; Smith, Howard; Chesley, Steve; Emery, Josh; Farnocchia, Davide; Fazio, Giovanni; Harris, Alan; Mueller, Migo

    2017-04-01

    The separation between asteroids and comets has become less clear with the discovery of a small group of asteroids that display comet-like activity. While the activity is attributed to different mechanisms, some objects seem to activate close to the Sun. Near-Earth Asteroids (NEAs) come close to the Earth and the Sun, constituting a natural laboratory for the study of thermally induced activity. Two NEA sub-populations are especially suspected of being potentially active: dormant comets and near-Sun asteroids. We propose 12.4 hrs of Spitzer IRAC observations of 3 near-Sun asteroids and one dormant comet (3552) Don Quixote, about which we have already published. Our goals are (1) to search for activity in Don Quixote, which showed CO/CO2 activity during its previous apparition and (2) to search for activity and measure the diameters and albedos of the near-Sun asteroids. In combination with a funded ground-based observing program, our results will provide significant legacy value to the investigation of activity in near-Earth asteroids.

  14. Mach's principle and hidden matter.

    Science.gov (United States)

    von Borzeszkowski, H.-H.; Treder, H.-J.

    1997-04-01

    According to the Einstein-Mayer theory of the Riemanniann space-time with Einstein-Cartan teleparallelism, the local Lorentz invariance is broken by the gravitational field defining Machian reference systems. This breaking of symmetry implies the occurrence of "hidden matter" in the Einstein equations of gravity. The hidden matter is described by the non-Lorentz-invariant energy-momentum tensor. According to this theory, in the universe and in cosmic systems one must except "invisible masses" described by the Poincaré and Einstein-Cartan terms to exist. The torsion field makes the space-time a Machian universe; it is of the same nature as the "weak interacting matter" discussed in astrophysics.

  15. Raising awareness of the hidden curriculum in veterinary medical education: a review and call for research.

    Science.gov (United States)

    Whitcomb, Tiffany L

    2014-01-01

    The hidden curriculum is characterized by information that is tacitly conveyed to and among students about the cultural and moral environment in which they find themselves. Although the hidden curriculum is often defined as a distinct entity, tacit information is conveyed to students throughout all aspects of formal and informal curricula. This unconsciously communicated knowledge has been identified across a wide spectrum of educational environments and is known to have lasting and powerful impacts, both positive and negative. Recently, medical education research on the hidden curriculum of becoming a doctor has come to the forefront as institutions struggle with inconsistencies between formal and hidden curricula that hinder the practice of patient-centered medicine. Similarly, the complex ethical questions that arise during the practice and teaching of veterinary medicine have the potential to cause disagreement between what the institution sets out to teach and what is actually learned. However, the hidden curriculum remains largely unexplored for this field. Because the hidden curriculum is retained effectively by students, elucidating its underlying messages can be a key component of program refinement. A review of recent literature about the hidden curriculum in a variety of fields, including medical education, will be used to explore potential hidden curricula in veterinary medicine and draw attention to the need for further investigation.

  16. On the hidden maxwell superalgebra underlying D = 4 supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Penafiel, D.M. [Departamento de Fisica, Universidad de Concepcion (Chile); DISAT, Politecnico di Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino (Italy); Ravera, L. [DISAT, Politecnico di Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino (Italy)

    2017-09-15

    In this work, we expand the hidden AdS-Lorentz superalgebra underlying D = 4 supergravity, reaching a (hidden) Maxwell superalgebra. The latter can be viewed as an extension involving cosmological constant of the superalgebra underlying D = 4 supergravity in flat spacetime. We write the Maurer-Cartan equations in this context and we find some interesting extensions of the antisymmetric 3-form A{sup (3)} appearing in the Free Differential Algebra in Minkowski space. The structure of Free Differential Algebras is obtained by considering the zero curvature equations. We write the parametrization of A{sup (3)} in terms of 1-forms and we rend the topological features of its extensions manifest. We interestingly find out that the structure of these extensions, and consequently the structure of the corresponding boundary contribution dA{sup (3)}, strongly depends on the form of the extra fermionic generator appearing in the hidden Maxwell superalgebra. The model we develop in this work is defined in an enlarged superspace with respect to the ordinary one, and the extra bosonic and fermionic 1-forms required for the closure of the hidden Maxwell superalgebra must be considered as physical fields in this enlarged superspace. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. THE ATMOSPHERES OF THE HOT-JUPITERS KEPLER-5b AND KEPLER-6b OBSERVED DURING OCCULTATIONS WITH WARM-SPITZER AND KEPLER

    Energy Technology Data Exchange (ETDEWEB)

    Desert, Jean-Michel; Charbonneau, David; Fressin, Francois; Latham, David W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Madhusudhan, Nikku [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Knutson, Heather A. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Deming, Drake [Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Borucki, William J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Brown, Timothy M. [Las Cumbres Observatory Global Telescope, Goleta, CA 93117 (United States); Caldwell, Douglas [SETI Institute, Mountain View, CA 94043 (United States); Ford, Eric B. [Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States); Gilliland, Ronald L. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Marcy, Geoffrey W. [Berkeley Astronomy Department, University of California, Berkeley, CA 94720 (United States); Seager, Sara, E-mail: jdesert@cfa.harvard.edu [Massachusetts Institute of Technology, Cambridge, MA 02159 (United States)

    2011-11-01

    This paper reports the detection and the measurements of occultations of the two transiting hot giant exoplanets Kepler-5b and Kepler-6b by their parent stars. The observations are obtained in the near-infrared with Warm-Spitzer Space Telescope and at optical wavelengths by combining more than a year of Kepler photometry. The investigation consists of constraining the eccentricities of these systems and of obtaining broadband emergent photometric data for individual planets. For both targets, the occultations are detected at the 3{sigma} level at each wavelength with mid-occultation times consistent with circular orbits. The brightness temperatures of these planets are deduced from the infrared observations and reach T{sub Spitzer} = 1930 {+-} 100 K and T{sub Spitzer} = 1660 {+-} 120 K for Kepler-5b and Kepler-6b, respectively. We measure optical geometric albedos A{sub g} in the Kepler bandpass and find A{sub g} = 0.12 {+-} 0.04 for Kepler-5b and A{sub g} = 0.11 {+-} 0.04 for Kepler-6b, leading to upper an limit for the Bond albedo of A{sub B} {<=} 0.17 in both cases. The observations for both planets are best described by models for which most of the incident energy is redistributed on the dayside, with only less than 10% of the absorbed stellar flux redistributed to the nightside of these planets.

  18. SPITZER OBSERVATIONS OF EXTENDED LYMAN-α CLOUDS IN THE SSA22 FIELD

    International Nuclear Information System (INIS)

    Webb, T. M. A.; Gonzalez, M.; Yamada, T.; Huang, J.-S.; Ashby, M. L. N; Matsuda, Y.; Egami, E.; Hayashimo, T.

    2009-01-01

    We present the results of a Spitzer IRAC and MIPS 24 μm study of extended Lyman-α clouds (or Lyman-α Blobs, LABs) within the SSA22 filamentary structure at z = 3.09. We detect 6/26 LABs in all IRAC filters, four of which are also detected at 24 μm, and find good correspondence with the 850 μm measurements of Geach et al. An analysis of the rest-frame ultraviolet, optical, near- and mid-infrared colors reveals that these six systems exhibit signs of nuclear activity (active galactic nucleus (AGN)) and/or extreme star formation. Notably, they have properties that bridge galaxies dominated by star formation (Lyman-break galaxies (LBGs)) and those with AGNs (LBGs classified as QSOs). The LAB systems not detected in all four IRAC bands, on the other hand, are, as a group, consistent with pure star-forming systems, similar to the majority of the LBGs within the filament. These results indicate that the galaxies within LABs do not comprise a homogeneous population, though they are also consistent with scenarios in which the gas halos are ionized through a common mechanism such as galaxy-scale winds driven by the galaxies within them, or gravitational heating of the collapsing cloud itself.

  19. Spitzer Observations of Massive, Red Galaxies at High Redshift

    Science.gov (United States)

    Papovich, C.; Moustakas, L. A.; Dickinson, M.; Le Floc'h, E.; Rieke, G. H.; Daddi, E.; Alexander, D. M.; Bauer, F.; Brandt, W. N.; Dahlen, T.; Egami, E.; Eisenhardt, P.; Elbaz, D.; Ferguson, H. C.; Giavalisco, M.; Lucas, R. A.; Mobasher, B.; Pérez-González, P. G.; Stutz, A.; Rieke, M. J.; Yan, H.

    2006-03-01

    We study massive galaxies at z~1-3.5 using HST optical imaging, ground-based near-IR imaging, and Spitzer observations at 3-24 μm. From Ks-selected galaxies in the ~=130 arcmin2 GOODS-S field, we identify 153 distant red galaxies (DRGs) with (J-Ks)Vega>=2.3. This sample is approximately complete in stellar mass for passively evolving galaxies above 1011 Msolar and z~4-6 mag) starbursts (at zmed~1.7). Very few DRGs (=1011 Msolar have specific star formation rates (SFRs per unit mass) including the reradiated far-IR emission that range from 0.2 to 10 Gyr-1. Based on the X-ray luminosities and rest-frame near-IR colors, roughly one-quarter of the DRGs contain AGNs, implying that the growth of supermassive black holes coincides with the formation of massive galaxies. At 1.5=1011 Msolar have an integrated specific SFR comparable to the global value of all galaxies. In contrast, galaxies at z~0.3-0.75 with M>=1011 Msolar have an integrated specific SFR less than the global value and more than an order of magnitude lower than that for massive DRGs. At zcontract 1407; on observations taken with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS5-26555 and on observations collected at the Kitt Peak National Observatory (KPNO), National Optical Astronomical Observatory (NOAO), which is operated by AURA, Inc., under cooperative agreement with the National Science Foundation. Observations have also been carried out using the Very Large Telescope at the ESO Paranal Observatory under program ID LP168.A-0485.

  20. GALACTIC CEPHEIDS WITH SPITZER. II. SEARCH FOR EXTENDED INFRARED EMISSION

    International Nuclear Information System (INIS)

    Barmby, P.; Marengo, M.; Evans, N. R.; Huelsman, D.; Fazio, G. G.; Bono, G.; Su, K. Y. L.; Welch, D. L.

    2011-01-01

    A deep and detailed examination of 29 classical Cepheids with the Spitzer Space Telescope has revealed three stars with strong nearby extended emission detected in multiple bands which appears to be physically associated with the stars. RS Pup was already known to possess extended infrared emission, while the extended emission around the other two stars (S Mus and δ Cep) is newly discovered in our observations. Four other stars (GH Lup, l Car, T Mon, and X Cyg) show tentative evidence for extended infrared emission. An unusual elongated extended object next to SZ Tau appears to be a background or foreground object in a chance alignment with the Cepheid. The inferred mass-loss rate upper limits for S Mus and δ Cep are in the range from 10 -9 to 10 -8 M sun yr -1 , with the upper limit for RS Pup as high as 10 -6 M sun yr -1 . Mass loss during post-main-sequence evolution has been proposed as a resolution to the discrepancy between pulsational and dynamical masses of Cepheid variable stars: dust in the lost material would make itself known by the presence of an infrared bright nebula or unresolved infrared excess. The observed frequency of infrared circumstellar emission (<24%) and the mass-loss rate we estimate for our sources show that dusty mass loss can only account for part of the Cepheid mass-loss discrepancy. Nevertheless, our direct evidence that mass loss is active during the Cepheid phase is an important confirmation that these processes need to be included in evolutionary and pulsation models of these stars and should be taken into account in the calibration of the Cepheid distance scale.

  1. NEOs in the mid-infrared: from Spitzer to JWST

    Science.gov (United States)

    Mueller, Michael; Thomas, Cristina A.

    2016-10-01

    Near-Earth Objects (NEOs) account for a surprisingly large fraction of the Spitzer observing time devoted to Solar System science. As a community, we should think of ways to repeat that success with JWST. JWST is planning an open Early Release Science Program, with the expected deadline for letters of intent in early 2017. We can't wait for next year's DPS to develop ideas. The time is now!In order to stir up the discussion, we will present ideas for NEO observing programs that are well adapted to JWST's capabilities and limitations, based on our recent PASP paper (Thomas et al., 2016). Obvious measurement objectives would include* size and albedo from thermal continuum (MIRI photometry)* thermal inertia for objects with well-known shape and spin state (MIRI)* taxonomy through reflection spectroscopy and emission spectroscopy in the NIR and MIR; NIR colors for faint objects.In all cases, JWST's sensitivity will allow us to go deeper than currently possible by at least an order of magnitude. Meter-sized NEOs similar to 2009 BD or 2011 MD are easy targets for MIRI spectrophotometry!The following limitations must be kept in mind, however: JWST's large size makes it slow to move. Most problematic for NEOs is probably the resulting 'speed limit': non-sidereal tracking is supported up to a rate of 30 mas/s, NEOs can easily move faster than that (ways to relax this constraint are under discussion). The average slew to a new target is budgeted to take 30 min, effectively ruling out programs many-target programs like ExploreNEOs or NEOSurvey (see D. Trilling's paper). Additionally, JWST will only observe close to quadrature, translating to large solar phase angles for NEO observations; this is familiar from other space-based IR facilities.

  2. Dust Processing in Supernova Remnants: Spitzer MIPS SED and IRS Observations

    Science.gov (United States)

    Hewitt, John W.; Petre, Robert; Katsuda Satoru; Andersen, M.; Rho, J.; Reach, W. T.; Bernard, J. P.

    2011-01-01

    We present Spitzer MIPS SED and IRS observations of 14 Galactic Supernova Remnants previously identified in the GLIMPSE survey. We find evidence for SNR/molecular cloud interaction through detection of [OI] emission, ionic lines, and emission from molecular hydrogen. Through black-body fitting of the MIPS SEDs we find the large grains to be warm, 29-66 K. The dust emission is modeled using the DUSTEM code and a three component dust model composed of populations of big grains, very small grains, and polycyclic aromatic hydrocarbons. We find the dust to be moderately heated, typically by 30-100 times the interstellar radiation field. The source of the radiation is likely hydrogen recombination, where the excitation of hydrogen occurred in the shock front. The ratio of very small grains to big grains is found for most of the molecular interacting SNRs to be higher than that found in the plane of the Milky Way, typically by a factor of 2--3. We suggest that dust shattering is responsible for the relative over-abundance of small grains, in agreement with prediction from dust destruction models. However, two of the SNRs are best fit with a very low abundance of carbon grains to silicate grains and with a very high radiation field. A likely reason for the low abundance of small carbon grains is sputtering. We find evidence for silicate emission at 20 $\\mu$m in their SEDs, indicating that they are young SNRs based on the strong radiation field necessary to reproduce the observed SEDs.

  3. Coding with partially hidden Markov models

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Rissanen, J.

    1995-01-01

    Partially hidden Markov models (PHMM) are introduced. They are a variation of the hidden Markov models (HMM) combining the power of explicit conditioning on past observations and the power of using hidden states. (P)HMM may be combined with arithmetic coding for lossless data compression. A general....... The PHMM structure and the conditions of the convergence proof allows for application of the PHMM to image coding. Relations between the PHMM and hidden Markov models (HMM) are treated. Results of coding bi-level images with the PHMM coding scheme is given. The results indicate that the PHMM can adapt...

  4. SPITZER OBSERVATIONS OF PASSIVE AND STAR-FORMING EARLY-TYPE GALAXIES: AN INFRARED COLOR-COLOR SEQUENCE

    International Nuclear Information System (INIS)

    Temi, Pasquale; Brighenti, Fabrizio; Mathews, William G.

    2009-01-01

    We describe the infrared properties of a large sample of early-type galaxies, comparing data from the Spitzer archive with Ks-band emission from the Two Micron All Sky Survey. While most representations of this data result in correlations with large scatter, we find a remarkably tight relation among colors formed by ratios of luminosities in Spitzer-Multiband Imaging Photometer bands (24, 70, and 160 μm) and the Ks band. Remarkably, this correlation among E and S0 galaxies follows that of nearby normal galaxies of all morphological types. In particular, the tight infrared color-color correlation for S0 galaxies alone follows that of the entire Hubble sequence of normal galaxies, roughly in order of galaxy type from ellipticals to spirals to irregulars. The specific star formation rate (SFR) of S0 galaxies estimated from the 24 μm luminosity increases with decreasing K-band luminosity (or stellar mass) from essentially zero, as with most massive ellipticals, to rates typical of irregular galaxies. Moreover, the luminosities of the many infrared-luminous S0 galaxies can significantly exceed those of the most luminous (presumably post-merger) E galaxies. SFRs in the most infrared-luminous S0 galaxies approach 1-10 solar masses per year. Consistently, with this picture we find that while most early-type galaxies populate an infrared red sequence, about 24% of the objects (mostly S0s) are in an infrared blue cloud together with late-type galaxies. For those early-type galaxies also observed at radio frequencies, we find that the far-infrared luminosities correlate with the mass of neutral and molecular hydrogen, but the scatter is large. This scatter suggests that the star formation may be intermittent or that similar S0 galaxies with cold gaseous disks of nearly equal mass can have varying radial column density distributions that alter the local and global SFRs.

  5. SPITZER SAGE-SMC INFRARED PHOTOMETRY OF MASSIVE STARS IN THE SMALL MAGELLANIC CLOUD

    International Nuclear Information System (INIS)

    Bonanos, A. Z.; Lennon, D. J.; Massa, D. L.

    2010-01-01

    We present a catalog of 5324 massive stars in the Small Magellanic Cloud (SMC), with accurate spectral types compiled from the literature, and a photometric catalog for a subset of 3654 of these stars, with the goal of exploring their infrared properties. The photometric catalog consists of stars with infrared counterparts in the Spitzer SAGE-SMC survey database, for which we present uniform photometry from 0.3to24 μm in the UBVIJHK s +IRAC+MIPS24 bands. We compare the color-magnitude diagrams and color-color diagrams to those of stars in the Large Magellanic Cloud (LMC), finding that the brightest infrared sources in the SMC are also the red supergiants, supergiant B[e] (sgB[e]) stars, luminous blue variables, and Wolf-Rayet stars, with the latter exhibiting less infrared excess, the red supergiants being less dusty and the sgB[e] stars being on average less luminous. Among the objects detected at 24 μm in the SMC are a few very luminous hypergiants, four B-type stars with peculiar, flat spectral energy distributions, and all three known luminous blue variables. We detect a distinct Be star sequence, displaced to the red, and suggest a novel method of confirming Be star candidates photometrically. We find a higher fraction of Oe and Be stars among O and early-B stars in our SMC catalog, respectively, when compared to the LMC catalog, and that the SMC Be stars occur at higher luminosities. We estimate mass-loss rates for the red supergiants, confirming the correlation with luminosity even at the metallicity of the SMC. Finally, we confirm the new class of stars displaying composite A and F type spectra, the sgB[e] nature of 2dFS1804 and find the F0 supergiant 2dFS3528 to be a candidate luminous blue variable with cold dust.

  6. A global analysis of Spitzer and new HARPS data confirms the loneliness and metal-richness of GJ 436 b

    Science.gov (United States)

    Lanotte, A. A.; Gillon, M.; Demory, B.-O.; Fortney, J. J.; Astudillo, N.; Bonfils, X.; Magain, P.; Delfosse, X.; Forveille, T.; Lovis, C.; Mayor, M.; Neves, V.; Pepe, F.; Queloz, D.; Santos, N.; Udry, S.

    2014-12-01

    Context. GJ 436b is one of the few transiting warm Neptunes for which a detailed characterisation of the atmosphere is possible, whereas its non-negligible orbital eccentricity calls for further investigation. Independent analyses of several individual datasets obtained with Spitzer have led to contradicting results attributed to the different techniques used to treat the instrumental effects. Aims: We aim at investigating these previous controversial results and developing our knowledge of the system based on the full Spitzer photometry dataset combined with new Doppler measurements obtained with the HARPS spectrograph. We also want to search for additional planets. Methods: We optimise aperture photometry techniques and the photometric deconvolution algorithm DECPHOT to improve the data reduction of the Spitzer photometry spanning wavelengths from 3-24 μm. Adding the high-precision HARPS radial velocity data, we undertake a Bayesian global analysis of the system considering both instrumental and stellar effects on the flux variation. Results: We present a refined radius estimate of RP = 4.10 ± 0.16 R⊕ , mass MP = 25.4 ± 2.1 M⊕, and eccentricity e = 0.162 ± 0.004 for GJ 436b. Our measured transit depths remain constant in time and wavelength, in disagreement with the results of previous studies. In addition, we find that the post-occultation flare-like structure at 3.6 μm that led to divergent results on the occultation depth measurement is spurious. We obtain occultation depths at 3.6, 5.8, and 8.0 μm that are shallower than in previous works, in particular at 3.6 μm. However, these depths still appear consistent with a metal-rich atmosphere depleted in methane and enhanced in CO/CO2, although perhaps less than previously thought. We could not detect a significant orbital modulation in the 8 μm phase curve. We find no evidence of a potential planetary companion, stellar activity, or a stellar spin-orbit misalignment. Conclusions: Recent theoretical

  7. Extracting Hidden-Photon Dark Matter From an LC-Circuit

    CERN Document Server

    Arias, Paola; Döbrich, Babette; Gamboa, Jorge; Méndez, Fernando

    2015-01-01

    We point out that a cold dark matter condensate made of gauge bosons from an extra hidden U(1) sector - dubbed hidden- photons - can create a small, oscillating electric density current. Thus, they could also be searched for in the recently proposed LC-circuit setup conceived for axion cold dark matter search by Sikivie, Sullivan and Tanner. We estimate the sensitivity of this setup for hidden-photon cold dark matter and we find it could cover a sizable, so far unexplored parameter space.

  8. Extracting hidden-photon dark matter from an LC-circuit

    International Nuclear Information System (INIS)

    Arias, Paola; Arza, Ariel; Gamboa, Jorge; Mendez, Fernando

    2014-11-01

    We point out that a cold dark matter condensate made of gauge bosons from an extra hidden U(1) sector - dubbed hidden-photons - can create a small, oscillating electric density current. Thus, they could also be searched for in the recently proposed LC-circuit setup conceived for axion cold dark matter search by Sikivie, Sullivan and Tanner. We estimate the sensitivity of this setup for hidden-photon cold dark matter and we find it could cover a sizable, so far unexplored parameter space.

  9. Extracting hidden-photon dark matter from an LC-circuit

    International Nuclear Information System (INIS)

    Arias, Paola; Arza, Ariel; Gamboa, Jorge; Mendez, Fernando; Doebrich, Babette

    2015-01-01

    We point out that a cold dark matter condensate made of gauge bosons from an extra hidden U(1) sector - dubbed hidden photons - can create a small, oscillating electric density current. Thus, they could also be searched for in the recently proposed LC-circuit setup conceived for axion cold dark matter search by Sikivie, Sullivan and Tanner. We estimate the sensitivity of this setup for hidden-photon cold dark matter and we find it could cover a sizable, so far unexplored parameter space. (orig.)

  10. Finding Hidden Treasures: Investigations in US Astronomical Plate Archives

    Czech Academy of Sciences Publication Activity Database

    Hudec, René; Hudec, L.

    2013-01-01

    Roč. 53, č. 1 (2013), s. 23-26 ISSN 1210-2709 R&D Projects: GA ČR GA205/08/1207 Institutional support: RVO:67985815 Keywords : astronomical data archives * astronomical photography * astronomical photographic archives Subject RIV: BH - Optics, Masers, Lasers

  11. Parallel MOPEX: Computing Mosaics of Large-Area Spitzer Surveys on a Cluster Computer

    Directory of Open Access Journals (Sweden)

    Joseph C. Jacob

    2007-01-01

    Full Text Available The Spitzer Science Center's MOPEX software is a part of the Spitzer Space Telescope's operational pipeline that enables detection of cosmic ray collisions with the detector array, masking of the corrupted pixels due to these collisions, subsequent mosaicking of image fields, and extraction of point sources to create catalogs of celestial objects. This paper reports on our experiences in parallelizing the parts of MOPEX related to cosmic ray rejection and mosaicking on a 1,024-processor cluster computer at NASA's Jet Propulsion Laboratory. The architecture and performance of the new Parallel MOPEX software are described. This work was done in order to rapidly mosaic the IRAC shallow survey data, covering a region of the sky observed with one of Spitzer's infrared instruments for the study of galaxy clusters, large-scale structure, and brown dwarfs.

  12. Social exclusion, health and hidden homelessness.

    Science.gov (United States)

    Watson, J; Crawley, J; Kane, D

    2016-10-01

    Homelessness and poverty are extreme forms of social exclusion which extend beyond the lack of physical or material needs. The purpose of this study was to explore and expand the concept of social exclusion within the social determinants of health perspective - to understand how the social environment, health behaviours and health status are associated with material and social deprivation. Fundamental qualitative description with tones of focused ethnography. Participants who identified as hidden homeless described their everyday living conditions and how these everyday conditions were impacted and influenced by their social environments, coping/health behaviours and current health status. Research Ethics Board approval was granted and informed consents were obtained from 21 participants prior to the completion of individual interviews. Qualitative content analysis examined the descriptions of men and women experiencing hidden homelessness. Participants described the 'lack of quality social interactions and supports' and their 'daily struggles of street life'. They also shared the 'pain of addiction' and how coping strategies influenced health. Participants were hopeful that their insights would 'better the health of homeless people' by helping shape public policy and funding of community resources that would reduce barriers and improve overall health. Health professionals who understand health behaviours as coping mechanisms for poor quality social environments can provide more comprehensive and holistic care. The findings of this study can be used to support the importance of housing as a key factor in the health and well-being of people experiencing poverty, homelessness and social exclusion; and consequently, reinforces the need for a national housing strategy. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  13. THE SPITZER INFRARED SPECTROGRAPH SURVEY OF T TAURI STARS IN TAURUS

    International Nuclear Information System (INIS)

    Furlan, E.; Luhman, K. L.; Espaillat, C.

    2011-01-01

    We present 161 Spitzer Infrared Spectrograph (IRS) spectra of T Tauri stars and young brown dwarfs in the Taurus star-forming region. All of the targets were selected based on their infrared excess and are therefore surrounded by protoplanetary disks; they form the complete sample of all available IRS spectra of T Tauri stars with infrared excesses in Taurus. We also present the IRS spectra of seven Class 0/I objects in Taurus to complete the sample of available IRS spectra of protostars in Taurus. We use spectral indices that are not significantly affected by extinction to distinguish between envelope- and disk-dominated objects. Together with data from the literature, we construct spectral energy distributions for all objects in our sample. With spectral indices derived from the IRS spectra we infer disk properties such as dust settling and the presence of inner disk holes and gaps. We find a transitional disk frequency, which is based on objects with unusually large 13-31 μm spectral indices indicative of a wall surrounding an inner disk hole, of about 3%, and a frequency of about 20% for objects with unusually large 10 μm features, which could indicate disk gaps. The shape and strength of the 10 μm silicate emission feature suggests weaker 10 μm emission and more processed dust for very low mass objects and brown dwarfs (spectral types M6-M9). These objects also display weaker infrared excess emission from their disks, but do not appear to have more settled disks than their higher-mass counterparts. We find no difference for the spectral indices and properties of the dust between single and multiple systems.

  14. Dust in a Type Ia Supernova Progenitor: Spitzer Spectroscopy of Kepler's Supernova Remnant

    Science.gov (United States)

    Williams, Brian J.; Borkowski, Kazimierz; Reynolds, Stephen P.; Ghavamian, Parviz; Blair, William P.; Long, Knox S.; Sankrit, Ravi

    2012-01-01

    Characterization of the relatively poorly-understood progenitor systems of Type Ia supernovae is of great importance in astrophysics, particularly given the important cosmological role that these supernovae play. Kepler's Supernova Remnant, the result of a Type Ia supernova, shows evidence for an interaction with a dense circumstellar medium (CSM), suggesting a single-degenerate progenitor system. We present 7.5-38 micron IR spectra of the remnant, obtained with the Spitzer Space Telescope, dominated by emission from warm dust. Broad spectral features at 10 and 18 micron, consistent with various silicate particles, are seen throughout. These silicates were likely formed in the stellar outflow from the progenitor system during the AGB stage of evolution, and imply an oxygen-rich chemistry. In addition to silicate dust, a second component, possibly carbonaceous dust, is necessary to account for the short-wavelength IRS and IRAC data. This could imply a mixed chemistry in the atmosphere of the progenitor system. However, non-spherical metallic iron inclusions within silicate grains provide an alternative solution. Models of collisionally-heated dust emission from fast shocks (> 1000 km/s) propagating into the CSM can reproduce the majority of the emission associated with non-radiative filaments, where dust temperatures are approx 80-100 K, but fail to account for the highest temperatures detected, in excess of 150 K. We find that slower shocks (a few hundred km/s) into moderate density material (n(sub o) approx 50-100 / cubic cm) are the only viable source of heating for this hottest dust. We confirm the finding of an overall density gradient, with densities in the north being an order of magnitude greater than those in the south.

  15. A Spitzer search for transits of radial velocity detected super-Earths

    International Nuclear Information System (INIS)

    Kammer, J. A.; Knutson, H. A.; Desert, J.-M.; Howard, A. W.; Laughlin, G. P.; Fortney, J. J.; Deming, D.; Todorov, K. O.; Agol, E.; Burrows, A.; Showman, A. P.; Lewis, N. K.

    2014-01-01

    Unlike hot Jupiters or other gas giants, super-Earths are expected to have a wide variety of compositions, ranging from terrestrial bodies like our own to more gaseous planets like Neptune. Observations of transiting systems, which allow us to directly measure planet masses and radii and constrain atmospheric properties, are key to understanding the compositional diversity of the planets in this mass range. Although Kepler has discovered hundreds of transiting super-Earth candidates over the past 4 yr, the majority of these planets orbit stars that are too far away and too faint to allow for detailed atmospheric characterization and reliable mass estimates. Ground-based transit surveys focus on much brighter stars, but most lack the sensitivity to detect planets in this size range. One way to get around the difficulty of finding these smaller planets in transit is to start by choosing targets that are already known to host super-Earth sized bodies detected using the radial velocity (RV) technique. Here we present results from a Spitzer program to observe six of the most favorable RV-detected super-Earth systems, including HD 1461, HD 7924, HD 156668, HIP 57274, and GJ 876. We find no evidence for transits in any of their 4.5 μm flux light curves, and place limits on the allowed transit depths and corresponding planet radii that rule out even the most dense and iron-rich compositions for these objects. We also observed HD 97658, but the observation window was based on a possible ground-based transit detection that was later ruled out; thus the window did not include the predicted time for the transit detection recently made by the Microvariability and Oscillations of Stars space telescope.

  16. Hidden multiparticle excitation in weakly interacting Bose-Einstein Condensate

    OpenAIRE

    Watabe, Shohei

    2017-01-01

    We investigate multiparticle excitation effect on a collective density excitation as well as a single-particle excitation in a weakly interacting Bose--Einstein condensate (BEC). We find that although the weakly interacting BEC offers weak multiparticle excitation spectrum at low temperatures, this multiparticle excitation effect may not remain hidden, but emerges as bimodality in the density response function through the single-particle excitation. Identification of spectra in the BEC betwee...

  17. Hidden neural networks: application to speech recognition

    DEFF Research Database (Denmark)

    Riis, Søren Kamaric

    1998-01-01

    We evaluate the hidden neural network HMM/NN hybrid on two speech recognition benchmark tasks; (1) task independent isolated word recognition on the Phonebook database, and (2) recognition of broad phoneme classes in continuous speech from the TIMIT database. It is shown how hidden neural networks...

  18. Insight: Exploring Hidden Roles in Collaborative Play

    Directory of Open Access Journals (Sweden)

    Tricia Shi

    2015-06-01

    Full Text Available This paper looks into interaction modes between players in co-located, collaborative games. In particular, hidden traitor games, in which one or more players is secretly working against the group mission, has the effect of increasing paranoia and distrust between players, so this paper looks into the opposite of a hidden traitor – a hidden benefactor. Rather than sabotaging the group mission, the hidden benefactor would help the group achieve the end goal while still having a reason to stay hidden. The paper explores what games with such a role can look like and how the role changes player interactions. Finally, the paper addresses the divide between video game and board game interaction modes; hidden roles are not common within video games, but they are of growing prevalence in board games. This fact, combined with the exploration of hidden benefactors, reveals that hidden roles is a mechanic that video games should develop into in order to match board games’ complexity of player interaction modes.

  19. Hard-bottom succession of subtidal epibenthic communities colonizing hidden and exposed surfaces off northern Chile

    Directory of Open Access Journals (Sweden)

    Aldo S. Pacheco

    2010-03-01

    Full Text Available The biodiversity of hard-bottom substrata comprises species growing on exposed rock and in hidden microhabitats, such as cracks and crevices. This study examines the succession of epibenthic organisms colonizing an artificial substratum with one surface exposed and one surface hidden on a vertical wall off northern Chile. On each sampling date species coverage of three replicate panels on both surfaces was assessed. The hidden surface was dominated in terms of coverage by the bryozoans Membranipora isabelleana and Lagenicella variabilis, while algae were absent. In contrast, the exposed surface was dominated by encrusting red corallines and the red alga Rhodymenia corallina. At the end of the experimental period both surfaces were dominated by colonial suspension feeders, but showed a different community structure and successional pattern. On the exposed surface, competitive exclusion was identified as an important aspect of succession, whereas on the hidden surface this pattern was not observed. These findings have implications for overall biodiversity, because pioneer species that are not able to survive long periods on exposed surfaces become restricted to hidden surfaces, from where they spread laterally. Thus, hidden microhabitats provide refuges for certain species, and may play an important role in the overall succession on rock faces. We conclude that examination of hidden microhabitats is necessary in order to fully understand succession in hard-bottom habitats.

  20. Searching for hidden-charm baryonium signals in QCD sum rules

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hua-Xing; Zhou, Dan [Beihang University, School of Physics, Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beijing (China); Chen, Wei [University of Saskatchewan, Department of Physics and Engineering Physics, Saskatoon, SK (Canada); Liu, Xiang [Lanzhou University, School of Physical Science and Technology, Lanzhou (China); Lanzhou University, Research Center for Hadron and CSR Physics, Institute of Modern Physics of CAS, Lanzhou (China); Zhu, Shi-Lin [Peking University, School of Physics, State Key Laboratory of Nuclear Physics and Technology, Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Peking University, Center of High Energy Physics, Beijing (China)

    2016-11-15

    We give an explicit QCD sum rule investigation for hidden-charm baryonium states with the quark content u anti ud anti dc anti c, spin J = 0/1/2/3, and of both positive and negative parities. We systematically construct the relevant local hidden-charm baryonium interpolating currents, which can actually couple to various structures, including hidden-charm baryonium states, charmonium states plus two pions, and hidden-charm tetraquark states plus one pion, etc. We do not know which structure these currents couple to at the beginning, but after sum rule analyses we can obtain some information. We find some of them can couple to hidden-charm baryonium states, using which we evaluate the masses of the lowest-lying hidden-charm baryonium states with quantum numbers J{sup P} = 2{sup -}/3{sup -}/0{sup +}/1{sup +}/2{sup +} to be around 5.0 GeV. We suggest to search for hidden-charm baryonium states, especially the one of J = 3{sup -}, in the D-wave J/ψππ and P-wave J/ψρ and J/ψω channels in this energy region. (orig.)

  1. Helioscope bounds on hidden sector photons

    International Nuclear Information System (INIS)

    Redondo, J.

    2008-01-01

    The flux of hypothetical ''hidden photons'' from the Sun is computed under the assumption that they interact with normal matter only through kinetic mixing with the ordinary standard model photon. Requiring that the exotic luminosity is smaller than the standard photon luminosity provides limits for the mixing parameter down to χ -14 , depending on the hidden photon mass. Furthermore, it is pointed point out that helioscopes looking for solar axions are also sensitive to hidden photons. The recent results of the CAST collaboration are used to further constrain the mixing parameter χ at low masses (m γ' <1 eV) where the luminosity bound is weaker. In this regime the solar hidden photon ux has a sizable contribution of longitudinally polarized hidden photons of low energy which are invisible for current helioscopes. (orig.)

  2. Hidden scale invariance of metals

    DEFF Research Database (Denmark)

    Hummel, Felix; Kresse, Georg; Dyre, Jeppe C.

    2015-01-01

    Density functional theory (DFT) calculations of 58 liquid elements at their triple point show that most metals exhibit near proportionality between the thermal fluctuations of the virial and the potential energy in the isochoric ensemble. This demonstrates a general “hidden” scale invariance...... of metals making the condensed part of the thermodynamic phase diagram effectively one dimensional with respect to structure and dynamics. DFT computed density scaling exponents, related to the Grüneisen parameter, are in good agreement with experimental values for the 16 elements where reliable data were...... available. Hidden scale invariance is demonstrated in detail for magnesium by showing invariance of structure and dynamics. Computed melting curves of period three metals follow curves with invariance (isomorphs). The experimental structure factor of magnesium is predicted by assuming scale invariant...

  3. A Direct Imaging Survey of Spitzer-detected Debris Disks: Occurrence of Giant Planets in Dusty Systems

    Science.gov (United States)

    Meshkat, Tiffany; Mawet, Dimitri; Bryan, Marta L.; Hinkley, Sasha; Bowler, Brendan P.; Stapelfeldt, Karl R.; Batygin, Konstantin; Padgett, Deborah; Morales, Farisa Y.; Serabyn, Eugene; Christiaens, Valentin; Brandt, Timothy D.; Wahhaj, Zahed

    2017-12-01

    We describe a joint high-contrast imaging survey for planets at the Keck and Very Large Telescope of the last large sample of debris disks identified by the Spitzer Space Telescope. No new substellar companions were discovered in our survey of 30 Spitzer-selected targets. We combine our observations with data from four published surveys to place constraints on the frequency of planets around 130 debris disk single stars, the largest sample to date. For a control sample, we assembled contrast curves from several published surveys targeting 277 stars that do not show infrared excesses. We assumed a double power-law distribution in mass and semimajor axis (SMA) of the form f(m,a)={{Cm}}α {a}β , where we adopted power-law values and logarithmically flat values for the mass and SMA of planets. We find that the frequency of giant planets with masses 5-20 M Jup and separations 10-1000 au around stars with debris disks is 6.27% (68% confidence interval 3.68%-9.76%), compared to 0.73% (68% confidence interval 0.20%-1.80%) for the control sample of stars without disks. These distributions differ at the 88% confidence level, tentatively suggesting distinctness of these samples. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation.

  4. THE SPITZER INFRARED SPECTROGRAPH SURVEY OF PROTOPLANETARY DISKS IN ORION A. I. DISK PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Kim, K. H. [Korea Astronomy and Space Science Institute (KASI), 776, Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Watson, Dan M.; Manoj, P.; Forrest, W. J. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Furlan, Elise [Infrared Processing and Analysis Center, Caltech, 770 S. Wilson Avenue, Pasadena, CA 91125 (United States); Najita, Joan [National Optical Astronomy Observatory, 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Sargent, Benjamin [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Dr., Rochester, NY 14623 (United States); Hernández, Jesús [Centro de Investigaciones de Astronomía, Apdo. Postal 264, Mérida 5101-A (Venezuela, Bolivarian Republic of); Calvet, Nuria [Department of Astronomy, University of Michigan, 830 Dennison Building, 500 Church Street, Ann Arbor, MI 48109 (United States); Adame, Lucía [Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma de Nuevo León, Av. Universidad S/N, San Nicolás de los Garza, Nuevo León, C.P. 66451, México (Mexico); Espaillat, Catherine [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Megeath, S. T. [Ritter Astrophysical Research Center, Department of Physics and Astronomy, University of Toledo, 2801 W. Bancroft St., Toledo, OH 43606 (United States); Muzerolle, James, E-mail: quarkosmos@kasi.re.kr [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); and others

    2016-09-01

    We present our investigation of 319 Class II objects in Orion A observed by Spitzer /IRS. We also present the follow-up observations of 120 of these Class II objects in Orion A from the Infrared Telescope Facility/SpeX. We measure continuum spectral indices, equivalent widths, and integrated fluxes that pertain to disk structure and dust composition from IRS spectra of Class II objects in Orion A. We estimate mass accretion rates using hydrogen recombination lines in the SpeX spectra of our targets. Utilizing these properties, we compare the distributions of the disk and dust properties of Orion A disks with those of Taurus disks with respect to position within Orion A (Orion Nebular Cluster [ONC] and L1641) and with the subgroups by the inferred radial structures, such as transitional disks (TDs) versus radially continuous full disks (FDs). Our main findings are as follows. (1) Inner disks evolve faster than the outer disks. (2) The mass accretion rates of TDs and those of radially continuous FDs are statistically significantly displaced from each other. The median mass accretion rate of radially continuous disks in the ONC and L1641 is not very different from that in Taurus. (3) Less grain processing has occurred in the disks in the ONC compared to those in Taurus, based on analysis of the shape index of the 10 μ m silicate feature ( F {sub 11.3}/ F {sub 9.8}). (4) The 20–31 μ m continuum spectral index tracks the projected distance from the most luminous Trapezium star, θ {sup 1} Ori C. A possible explanation is UV ablation of the outer parts of disks.

  5. Detection of Planetary Emission from the Exoplanet TrES-2 Using Spitzer/IRAC

    Science.gov (United States)

    Donovan, Francis T.; Charbonneau, David; Harrington, Joseph; Madhusudhan, N.; Seager, Sara; Deming, Drake; Knutson, Heather A.

    2010-01-01

    We present here the results of our observations of TrES-2 using the Infrared Array Camera on Spitzer. We monitored this transiting system during two secondary eclipses, when the planetary emission is blocked by the star. The resulting decrease in flux is 0.127% +/- 0.021%, 0.230% +/- 0.024%, 0.199% +/- 0.054%, and 0.359% +/- 0.060% at 3.6 microns, 4.5 microns, 5.8 microns, and 8.0 microns, respectively. We show that three of these flux contrasts are well fit by a blackbody spectrum with T(sub eff) = 1500 K, as well as by a more detailed model spectrum of a planetary atmosphere. The observed planet-to-star flux ratios in all four lRAC channels can be explained by models with and without a thermal inversion in the atmosphere of TrES-2, although with different atmospheric chemistry. Based on the assumption of thermochemical equilibrium, the chemical composition of the inversion model seems more plausible, making it a more favorable scenario. TrES-2 also falls in the category of highly irradiated planets which have been theoretically predicted to exhibit thermal inversions. However, more observations at infrared and visible wavelengths would be needed to confirm a thermal inversion in this system. Furthermore, we find that the times of the secondary eclipses are consistent with previously published times of transit and the expectation from a circular orbit. This implies that TrES-2 most likely has a circular orbit, and thus does not obtain additional thermal energy from tidal dissipation of a non-zero orbital eccentricity, a proposed explanation for the large radius of this planet. Key words: eclipses - infrared: stars - planetary systems - stars: individual (OSC 03549-02811) - techniques: photometric

  6. PHOTOMETRIC MONITORING OF THE COLDEST KNOWN BROWN DWARF WITH THE SPITZER SPACE TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Esplin, T. L.; Luhman, K. L. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Cushing, M. C.; Hardegree-Ullman, K. K.; Trucks, J. L.; Schneider, A. C. [Department of Physics and Astronomy, The University of Toledo, OH 43606 (United States); Burgasser, A. J., E-mail: taran.esplin@psu.edu [Center for Astrophysics and Space Science, University of California San Diego, La Jolla, CA 92093 (United States)

    2016-11-20

    Because WISE J085510.83-071442.5 (hereafter WISE 0855-0714) is the coldest known brown dwarf (∼250 K) and one of the Sun’s closest neighbors (2.2 pc), it offers a unique opportunity to study a planet-like atmosphere in an unexplored regime of temperature. To detect and characterize inhomogeneities in its atmosphere (e.g., patchy clouds, hot spots), we have performed time-series photometric monitoring of WISE 0855-0714 at 3.6 and 4.5 μ m with the Spitzer Space Telescope during two 23 hr periods that were separated by several months. For both bands, we have detected variability with peak-to-peak amplitudes of 4%–5% and 3%–4% in the first and second epochs, respectively. The light curves are semiperiodic in the first epoch for both bands, but they are more irregular in the second epoch. Models of patchy clouds have predicted a large increase in mid-infrared (mid-IR) variability amplitudes (for a given cloud covering fraction) with the appearance of water ice clouds at T {sub eff} < 375 K, so if such clouds are responsible for the variability of WISE 0855-0714, then its small amplitudes of variability indicate a very small deviation in cloud coverage between hemispheres. Alternatively, the similarity in mid-IR variability amplitudes between WISE 0855-0714 and somewhat warmer T and Y dwarfs may suggest that they share a common origin for their variability (i.e., not water clouds). In addition to our variability data, we have examined other constraints on the presence of water ice clouds in the atmosphere of WISE 0855-0714, including the recent mid-IR spectrum from Skemer et al. (2016). We find that robust evidence of such clouds is not yet available.

  7. Asteroid (16) Psyche: Evidence for a silicate regolith from spitzer space telescope spectroscopy

    Science.gov (United States)

    Landsman, Zoe A.; Emery, Joshua P.; Campins, Humberto; Hanuš, Josef; Lim, Lucy F.; Cruikshank, Dale P.

    2018-04-01

    Asteroid (16) Psyche is a unique, metal-rich object belonging to the "M" taxonomic class. It may be a remnant protoplanet that has been stripped of most silicates by a hit-and-run collision. Because Psyche offers insight into the planetary formation process, it is the target of NASA's Psyche mission, set to launch in 2023. In order to constrain Psyche's surface properties, we have carried out a mid-infrared (5-14 μm) spectroscopic study using data collected with the Spitzer Space Telescope's Infrared Spectrograph. Our study includes two observations covering different rotational phases. Using thermophysical modeling, we find that Psyche's surface is smooth and likely has a thermal inertia Γ = 5-25 J/m2/K/s1/2 and bolometric emissivity ɛ = 0.9, although a scenario with ɛ = 0.7 and thermal inertia up to 95 J/m2/K/s1/2 is possible if Psyche is somewhat larger than previously determined. The smooth surface is consistent with the presence of a metallic bedrock, which would be more ductile than silicate bedrock, and thus may not readily form boulders upon impact events. From comparisons with laboratory spectra of silicate and meteorite powders, Psyche's 7-14 μm emissivity spectrum is consistent with the presence of fine-grained (< 75 μm) silicates on Psyche's surface. We conclude that Psyche is likely covered in a fine silicate regolith, which may also contain iron grains, overlying an iron-rich bedrock.

  8. Physical Properties of Asteroid (10302) 1989 ML, a Potential Spacecraft Target, from Spitzer Observations

    NARCIS (Netherlands)

    Mueller, Michael; Harris, A. W.

    2006-01-01

    We report on results from recent Spitzer observations of near-Earth asteroid (10302) 1989 ML, which is among the lowest-ranking objects in terms of the specific momentum Δv required to reach it from Earth. It was originally considered as a target for Hayabusa and is now under consideration as a

  9. THE TAURUS SPITZER SURVEY: NEW CANDIDATE TAURUS MEMBERS SELECTED USING SENSITIVE MID-INFRARED PHOTOMETRY

    International Nuclear Information System (INIS)

    Rebull, L. M.; Padgett, D. L.; McCabe, C.-E.; Noriega-Crespo, A.; Carey, S. J.; Brooke, T.; Hillenbrand, L. A.; Stapelfeldt, K. R.; Angione, J. R.; Huard, T.; Terebey, S.; Audard, M.; Baldovin-Saavedra, C.; Monin, J.-L.; Menard, F.; Bouvier, J.; Fukagawa, M.; Guedel, M.; Knapp, G. R.; Allen, L. E.

    2010-01-01

    We report on the properties of pre-main-sequence objects in the Taurus molecular clouds as observed in seven mid- and far-infrared bands with the Spitzer Space Telescope. There are 215 previously identified members of the Taurus star-forming region in our ∼44 deg 2 map; these members exhibit a range of Spitzer colors that we take to define young stars still surrounded by circumstellar dust (noting that ∼20% of the bona fide Taurus members exhibit no detectable dust excesses). We looked for new objects in the survey field with similar Spitzer properties, aided by extensive optical, X-ray, and ultraviolet imaging, and found 148 new candidate members of Taurus. We have obtained follow-up spectroscopy for about half the candidate sample, thus far confirming 34 new members, three probable new members, and 10 possible new members, an increase of 15%-20% in Taurus members. Of the objects for which we have spectroscopy, seven are now confirmed extragalactic objects, and one is a background Be star. The remaining 93 candidate objects await additional analysis and/or data to be confirmed or rejected as Taurus members. Most of the new members are Class II M stars and are located along the same cloud filaments as the previously identified Taurus members. Among non-members with Spitzer colors similar to young, dusty stars are evolved Be stars, planetary nebulae, carbon stars, galaxies, and active galactic nuclei.

  10. The Accuracy of the Warm Spitzer Near-Earth Object Survey

    NARCIS (Netherlands)

    Harris, Alan W.; Mommert, M.; Hora, J. L.; Mueller, M.; Trilling, D. E.; Bhattacharya, B.; Bottke, W. F.; Chesley, S.; Delbo', M.; Emery, J. P.; Fazio, G. G.; Mainzer, A.; Penprase, B.; Smith, H. A.; Spahr, T. B.; Stansberry, J. A.; Thomas, C. A.

    2010-01-01

    We report on observations of near-Earth objects (NEOs) performed with IRAC as part of our on-going (2009-2011) Warm Spitzer NEO survey ("ExploreNEOs"), the primary aim of which is to provide sizes and albedos of some 700 NEOs. The emphasis of the work described here is an assessment of the overall

  11. Spitzer Observations of OGLE-2015-BLG-1212 Reveal a New Path toward Breaking Strong Microlens Degeneracies

    DEFF Research Database (Denmark)

    Bozza, V.; Shvartzvald, Y.; Udalski, A.

    2016-01-01

    Spitzer microlensing parallax observations of OGLE-2015-BLG-1212 decisively break a degeneracy between planetary and binary solutions that is somewhat ambiguous when only ground-based data are considered. Only eight viable models survive out of an initial set of 32 local minima in the parameter s...

  12. HST and Spitzer point source and dust lane detection in powerful narrow-line radio galaxies

    Science.gov (United States)

    Ramírez, E. A.; Tadhunter, C. N.; Dicken, D.; Rose, M.; Axon, D. J.; Sparks, W.

    2014-10-01

    We present the analysis of infrared HST and Spitzer data for a sample of 13 FRII powerful radio galaxies at 0.03 scale toroidal structure when this is viewed edge-on (Barthel 1989, Antonucci 1993). Our high resolution infrared observations provide new information about the optical extinction, orientation, and direct AGN detection of the inner kpc-scale region of the AGN.

  13. Random walks, Brownian motion, and interacting particle systems: a festschrift in honor of Frank Spitzer

    National Research Council Canada - National Science Library

    Durrett, Richard; Kesten, Harry; Spitzer, Frank

    1991-01-01

    ..., made the transparency used in the printing process. STUDENTS OF FRANK SPITZERSTUDENTS OF FRANK SPITZER 1957 J. W. Lamperti, On the asymptotic behavior of recurrent and almostrecurrent events. 1964 W. W. Whitman, Some strong laws for random walks and Brownian motion. 1965 J. C. Mineka, The existence and uniqueness of positive solutions to the Wien...

  14. Thermal properties of Trans-Neptunian objects and Centaurs from combined Herschel and Spitzer observations

    NARCIS (Netherlands)

    Santos-Sanz, P.; Lellouch, E.; Mommert, M.; Fornasier, S.; Stansberry, J.; Mueller, Th.; Kiss, C.; Vilenius, E.; Mueller, M.; Harris, A. W.; Delsanti, A.; Groussin, O.

    2012-01-01

    We present a study of the thermal properties of about 70 trans-Neptunian objects (TNOs) and Centaurs observed with Herschel Space Observatory [8] (either PACS or PACS and SPIRE) and Spitzer Space Telescope [12] (MIPS). We apply radiometric modeling techniques (NEATM [2]) to the measured fluxes to

  15. Thermal Properties Of Trans-neptunian Objects And Centaurs From Combined Herschel And Spitzer Observations

    NARCIS (Netherlands)

    Lellouch, Emmanuel; Santos-Sanz, P.; Mommert, M.; Fornasier, S.; Stansberry, J.; Müller, T.; Duffard, R.; Ortiz, J.; Kiss, C.; Vilenius, E.; Mueller, M.; Lacerda, P.; Harris, A.; TNOs are Cool Team, [No Value

    2012-01-01

    We present a study of the thermal properties of about 70 trans-Neptunian objects (TNOs) and Centaurs observed with Herschel Space Observatory (either PACS or PACS/SPIRE) and Spitzer (MIPS). The combined wavelength range is 24-160 μm and additionally up to 500 μm for a few targets. We apply

  16. Dust evolution in protoplanetary disks around Herbig Ae/Be stars—the Spitzer view

    NARCIS (Netherlands)

    Juhász, A.; Bouwman, J.; Henning, T.; Acke, B.; van den Ancker, M.E.; Meeus, G.; Dominik, C.; Min, M.; Tielens, A.G.G.M.; Waters, L.B.F.M.

    2010-01-01

    In this paper, we present mid-infrared spectra of a comprehensive set of Herbig Ae/Be stars observed with the Spitzer Space Telescope. The signal-to-noise ratio of these spectra is very high, ranging between about a hundred and several hundreds. During the analysis of these data we tested the

  17. Waters, dust evolution in protoplanetary disks around herbig ae/be stars—the spitzer view

    NARCIS (Netherlands)

    Juhász, A.; Bouwman, J.; Henning, Th.; Acke, B.; Van Den Ancker, M.; Meeus, G.; Dominik, C.; Min, M.|info:eu-repo/dai/nl/277318416; Tielens, A. G. G. M.; Waters, L.B.F.M.

    2010-01-01

    In this paper, we present mid-infrared spectra of a comprehensive set of Herbig Ae/Be stars observed with the Spitzer Space Telescope. The signal-to-noise ratio of these spectra is very high, ranging between about a hundred and several hundreds. During the analysis of these data we tested the

  18. Dust Evolution in Protoplanetary Disks Around Herbig Ae/Be Stars—the Spitzer View

    NARCIS (Netherlands)

    Juhasz, A.; Bouwman, J.; Henning, Th.; Acke, B.; van den Ancker, M. E.; Meeus, G.; Dominik, C.; Min, M.; Tielens, A. G. G. M.; Waters, L. B. F. M.

    2010-01-01

    In this paper, we present mid-infrared spectra of a comprehensive set of Herbig Ae/Be stars observed with the Spitzer Space Telescope. The signal-to-noise ratio of these spectra is very high, ranging between about a hundred and several hundreds. During the analysis of these data we tested the

  19. The Spitzer IRS infrared spectrum and abundances of the planetary nebula IC 2448

    NARCIS (Netherlands)

    Guiles, S.; Bernard-Salas, J.; Pottasch, S. R.; Roellig, T. L.

    2007-01-01

    We present the mid-infrared spectrum of the planetary nebula IC 2448. In order to determine the chemical composition of the nebula, we use the infrared line fluxes from the Spitzer spectrum along with optical line fluxes from the literature and ultraviolet line fluxes from archival IUE spectra. We

  20. Visible photometry of NEOs in support of a Warm Spitzer program

    Science.gov (United States)

    Trilling, David E.; Jones, Sarah; Penprase, Bryan; Emery, Josh; Harris, Alan; Spahr, Tim; Delbo, Marco

    2009-08-01

    Near Earth Objects (NEOs) may act as dynamical and compositional tracers of the history of near-Earth space. However, despite their scientific importance, key characteristics of the NEO population -- such as the size distribution, mix of albedos and mineralogies, and contributions from so-called dead or dormant comets -- remain largely unexplored; some 99% of all presently known NEOs are essentially uncharacterized. We have been awarded 500 hours of Warm Spitzer time to study some 700 NEOs. The Spitzer data will allow us to measure thermal fluxes and, in combination with optical data, derive albedos and diameters for a large fraction of all known NEOs. Remarkably, the primary uncertainty in our Spitzer results will derive from a lack of good optical photometry for our targets. Fortunately, our targets are generally bright, and obtaining good V band measurements of them requires only a modest amount of time on modest aperture telescopes. We propose here for 36 hours of SMARTS 1.3-m time or 54 hours of SMARTS 0.9-m time to obtain visible photometry of the 72 southern moderately bright ``B'' semester targets in our Warm Spitzer program. These program is ideal for queue/service observing because each observation requires only ~30 minutes and our targets are all over the sky.

  1. Bulk Densities of Binary Asteroids from the Warm Spitzer NEO Survey

    NARCIS (Netherlands)

    Kistler, John; Trilling, D. E.; Mueller, M.; Hora, J. L.; Harris, A. W.; Bhattacharya, B.; Bottke, W. F.; Chesley, S.; Emery, J. P.; Fazo, G.; Mainzer, A.; Penprase, B.; Smith, H. A.; Spahr, T. B.; Stansberry, J. A.; Thomas, C. A.

    2010-01-01

    The Warm Spitzer NEO survey, ExploreNEOs, will observe approximately 700 Near Earth Asteroids. Several of these objects are known to be binary asteroid systems. Binary systems are interesting due to the unique opportunity they present for determining the masses and densities of their constituent

  2. A Search for Additional Bodies in the GJ 1132 Planetary System from 21 Ground-based Transits and a 100-hr Spitzer Campaign

    Science.gov (United States)

    Dittmann, Jason A.; Irwin, Jonathan M.; Charbonneau, David; Berta-Thompson, Zachory K.; Newton, Elisabeth R.

    2017-10-01

    We present the results of a search for additional bodies in the GJ 1132 system through two methods: photometric transits and transit timing variations of GJ 1132b. We collected 21 transit observations of GJ 1132b with the MEarth-South array. We obtained 100 near-continuous hours of observations with the Spitzer Space Telescope, including two transits of GJ 1132b and spanning 60% of the orbital phase of the maximum (6.9-day) period at which bodies coplanar with GJ 1132b would transit. We exclude transits of additional Mars-sized bodies, such as a second planet or a moon, with a confidence of 99.7%. We find that the planet-to-star radius ratio inferred from the MEarth and Spitzer light curves are discrepant at the 3.7σ level, which we ascribe to the effects of starspots and faculae. When we combine the mass estimate of the star (obtained from its parallax and apparent K s band magnitude) with the stellar density inferred from our high-cadence Spitzer light curve (assuming zero eccentricity), we measure the stellar radius of GJ 1132 to be {0.2105}-0.0085+0.0102 {R}⊙ , and we refine the radius measurement of GJ 1132b to 1.130+/- 0.056 {R}\\oplus . Combined with HARPS RV measurements, we determine the density of GJ 1132b to be 6.2 ± 2.0 g cm-3. We refine the ephemeris of the system (improving the period determination by an order of magnitude) and find no evidence for transit timing variations, which would be expected if there was a second planet near an orbital resonance with GJ 1132b.

  3. Sterile neutrino, hidden dark matter and their cosmological signatures

    International Nuclear Information System (INIS)

    Das, Subinoy

    2012-01-01

    Though thermal dark matter has been the central idea behind the dark matter candidates, it is highly possible that dark matter of the universe is non-thermal in origin or it might be in thermal contact with some hidden or dark sector but not with standard model. Here we explore the cosmological bounds as well as the signatures on two types of non-thermal dark matter candidates. First we discuss a hidden dark matter with almost no interaction (or very feeble) with standard model particles so that it is not in thermal contact with visible sector but we assume it is thermalized with in a hidden sector due to some interaction. While encompassing the standard cold WIMP scenario, we do not require the freeze-out process to be non-relativistic. Rather, freeze-out may also occur when dark matter particles are semi-relativistic or relativistic. Especially we focus on the warm dark matter scenario in this set up and find the constraints on the warm dark matter mass, cross-section and hidden to visible sector temperature ratio which accounts for the observed dark-matter density, satisfies the Tremaine-Gunn bound on dark-matter phase space density and has a free-streaming length consistent with cosmological constraints on the matter power spectrum. Our method can also be applied to keV sterile neutrino dark matter which is not thermalized with standard model but is thermalized with in a dark sector. The second part of this proceeding focuses on an exotic dark matter candidate which arises from the existence of eV mass sterile neutrino through a late phase transition. Due to existence of a strong scalar force the light sterile states get trapped into stable degenerate micro nuggets. We find that its signature in matter power spectra is close to a warm dark matter candidate.

  4. A survey of hidden-variables theories

    CERN Document Server

    Belinfante, F J

    1973-01-01

    A Survey of Hidden-Variables Theories is a three-part book on the hidden-variable theories, referred in this book as """"theories of the first kind"""". Part I reviews the motives in developing different types of hidden-variables theories. The quest for determinism led to theories of the first kind; the quest for theories that look like causal theories when applied to spatially separated systems that interacted in the past led to theories of the second kind. Parts II and III further describe the theories of the first kind and second kind, respectively. This book is written to make the literat

  5. New Results from Spitzer's Journey Through The Earth's Resonant Ring: 2004-2006

    Science.gov (United States)

    Jayaraman, Sumita; Grogan, K.; Bhattacharya, B.; Reach, W. T.

    2006-09-01

    The Spitzer Space Telescope, in its solar orbit, has been drifting away from the Earth - enabling it to trace a path through the Earth's Resonant Ring, specifically, traverse through the resonant dust cloud that follows the Earth. The dust cloud causes the mid-infrared flux in the sky to be higher in the trailing direction when viewed from the Earth. After launch, Spitzer has slowly entered into the dust cloud and has crossed over the peak dust density of the trailing dust cloud. This causes a change in the trailing/leading asymmetry in the background flux. Eventually the leading flux will be higher as Spitzer views the cloud from the opposite side at the end of the mission. We have designed a zodiacal background monitoring program for the ecliptic and north and south ecliptic poles to obtain absolutely calibrated data in the MIPS total power mode. This program includes observations from 2004 to 2006 and will continue into the next observation cycle. We present new results measuring the change in the zodiacal background radiation at 24 microns in combination with science calibration observation observations from IRAC during this period. Further comparison of the multi-wavelength measurements to models shows the detailed ring structure and the provide estimates of the ring dust density in the Resonant Ring. We would like to thank NASA/JPL for funding this program through the Spitzer GO Cycle. We would also like to thank the Spitzer Science Center for helping us to schedule the individual solar system observations after the MIPS campaign dates are fixed and contributing the IRAC calibration observations.

  6. Hidden costs, value lost: uninsurance in America

    National Research Council Canada - National Science Library

    Committee on the Consequences of Uninsurance; Board on Health Care Services; Institute of Medicine; National Academy of Sciences

    2003-01-01

    Hidden Cost, Value Lost , the fifth of a series of six books on the consequences of uninsurance in the United States, illustrates some of the economic and social losses to the country of maintaining...

  7. The hidden epidemic: confronting sexually transmitted diseases

    National Research Council Canada - National Science Library

    Eng, Thomas R; Butler, William T

    .... In addition, STDs increase the risk of HIV transmission. The Hidden Epidemic examines the scope of sexually transmitted infections in the United States and provides a critical assessment of the nation's response to this public health crisis...

  8. Matriarki dan Hidden Women dalam Syair Damarwulan

    Directory of Open Access Journals (Sweden)

    Dwi Susanto

    2007-12-01

    Full Text Available The story of Damarwulan was a popular story. The reception toward this story was various. Syair, hikayat, legendriya, serat, and performance found at Javanist. Toe Syair of Damarwulan ML 176 appears many characteristics. The reading of this syair discovered much suspicious about the position of Queen of Majapahit, Kenconowungu. This paper explores matriarchal and hidden women into Syair Damarwulan. This paper used feminist perspective to explore matriarchal and hidden women. This paper has concluded that the process of matriarchal was always followed by hidden women. Relation of Queen Kenconowungu­ Menakjinggo and Damarwulan was one of several evidence. The presence of Damarwulan as a hero and image of idol man was the end • of process hidden women

  9. Physical Characterization of Warm Spitzer-observed Near-Earth Objects

    Science.gov (United States)

    Thomas, Cristina A.; Emery, Joshua P.; Trilling, David E.; Delbo, Marco; Hora, Joseph L.; Mueller, Michael

    2014-01-01

    Near-infrared spectroscopy of Near-Earth Objects (NEOs) connects diagnostic spectral features to specific surface mineralogies. The combination of spectroscopy with albedos and diameters derived from thermal infrared observations can increase the scientific return beyond that of the individual datasets. For instance, some taxonomic classes can be separated into distinct compositional groupings with albedo and different mineralogies with similar albedos can be distinguished with spectroscopy. To that end, we have completed a spectroscopic observing campaign to complement the ExploreNEOs Warm Spitzer program that obtained albedos and diameters of nearly 600 NEOs (Trilling et al., 2010). The spectroscopy campaign included visible and near-infrared observations of ExploreNEOs targets from various observatories. Here we present the results of observations using the low-resolution prism mode (approx. 0.7-2.5 microns) of the SpeX instrument on the NASA Infrared Telescope Facility (IRTF). We also include near-infrared observations of Explore-NEOs targets from the MIT-UH-IRTF Joint Campaign for Spectral Reconnaissance. Our dataset includes near-infrared spectra of 187 ExploreNEOs targets (125 observations of 92 objects from our survey and 213 observations of 154 objects from the MIT survey). We identify a taxonomic class for each spectrum and use band parameter analysis to investigate the mineralogies for the S-, Q-, and V-complex objects. Our analysis suggests that for spectra that contain near-infrared data but lack the visible wavelength region, the Bus-DeMeo system misidentifies some S-types as Q-types. We find no correlation between spectral band parameters and ExploreNEOs albedos and diameters. We investigate the correlations of phase angle with band area ratio and near-infrared spectral slope. We find slightly negative Band Area Ratio (BAR) correlations with phase angle for Eros and Ivar, but a positive BAR correlation with phase angle for Ganymed.The results of our

  10. High Energy Colliders and Hidden Sectors

    Science.gov (United States)

    Dror, Asaf Jeff

    This thesis explores two dominant frontiers of theoretical physics, high energy colliders and hidden sectors. The Large Hadron Collider (LHC) is just starting to reach its maximum operational capabilities. However, already with the current data, large classes of models are being put under significant pressure. It is crucial to understand whether the (thus far) null results are a consequence of a lack of solution to the hierarchy problem around the weak scale or requires expanding the search strategy employed at the LHC. It is the duty of the current generation of physicists to design new searches to ensure that no stone is left unturned. To this end, we study the sensitivity of the LHC to the couplings in the Standard Model top sector. We find it can significantly improve the measurements on ZtRtR coupling by a novel search strategy, making use of an implied unitarity violation in such models. Analogously, we show that other couplings in the top sector can also be measured with the same technique. Furthermore, we critically analyze a set of anomalies in the LHC data and how they may appear from consistent UV completions. We also propose a technique to measure lifetimes of new colored particles with non-trivial spin. While the high energy frontier will continue to take data, it is likely the only collider of its kind for the next couple decades. On the other hand, low-energy experiments have a promising future with many new proposed experiments to probe the existence of particles well below the weak scale but with small couplings to the Standard Model. In this work we survey the different possibilities, focusingon the constraints as well as possible new hidden sector dynamics. In particular, we show that vector portals which couple to an anomalous current, e.g., baryon number, are significantly constrained from flavor changing meson decays and rare Z decays. Furthermore, we present a new mechanism for dark matter freezeout which depletes the dark sector through an

  11. Workplace ageism: discovering hidden bias.

    Science.gov (United States)

    Malinen, Sanna; Johnston, Lucy

    2013-01-01

    BACKGROUND/STUDY CONTEXT: Research largely shows no performance differences between older and younger employees, or that older workers even outperform younger employees, yet negative attitudes towards older workers can underpin discrimination. Unfortunately, traditional "explicit" techniques for assessing attitudes (i.e., self-report measures) have serious drawbacks. Therefore, using an approach that is novel to organizational contexts, the authors supplemented explicit with implicit (indirect) measures of attitudes towards older workers, and examined the malleability of both. This research consists of two studies. The authors measured self-report (explicit) attitudes towards older and younger workers with a survey, and implicit attitudes with a reaction-time-based measure of implicit associations. In addition, to test whether attitudes were malleable, the authors measured attitudes before and after a mental imagery intervention, where the authors asked participants in the experimental group to imagine respected and valued older workers from their surroundings. Negative, stable implicit attitudes towards older workers emerged in two studies. Conversely, explicit attitudes showed no age bias and were more susceptible to change intervention, such that attitudes became more positive towards older workers following the experimental manipulation. This research demonstrates the unconscious nature of bias against older workers, and highlights the utility of implicit attitude measures in the context of the workplace. In the current era of aging workforce and skill shortages, implicit measures may be necessary to illuminate hidden workplace ageism.

  12. Detecting hidden sources-STUK/HUT team

    Energy Technology Data Exchange (ETDEWEB)

    Nikkinen, M.; Aarnio, P. [Helsinki Univ. of Technology, Espoo (Finland); Honkamaa, T.; Tiilikainen, H. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland)

    1997-12-31

    The task of the team was to locate and to identify hidden sources in a specified area in Padasjoki Auttoinen village. The team used AB-420 helicopter of the Finnish Frontier Guard. The team had two measuring systems: HPGe system (relative efficiency 18%) and 5`x5` NaI system. The team found two sources in real-time and additional two sources after 24 h analysis time. After the locations and characteristics of the sources were announced it was found out that altogether six sources would have been possible to find using the measured data. The total number of sources was ten. The NaI detector was good at detecting and locating the sources and HPGe was most useful in identification and calculation of the activity estimates. The following development should be made: 1) larger detectors are needed, 2) the software has to be improved. (This has been performed after the exercise) and 3) the navigation must be based on DGPS. visual navigation causes easily gaps between the flight lines and some sources may not be detected. (au).

  13. CSO CO (2–1) and Spitzer IRAC observations of a bipolar outflow in high-mass star-forming region IRAS 22506+5944

    Science.gov (United States)

    Xie, Ze-Qiang; Qiu, Ke-Ping

    2018-02-01

    We present Caltech Submillimeter Observatory CO (2–1) and Spitzer IRAC observations toward IRAS 22506+5944, which is a 104 L ⊙ massive star-forming region. The CO (2–1) maps show an east-west bipolar molecular outflow originating from the 3 mm dust continuum peak. The Spitzer IRAC color-composite image reveals a pair of bow-shaped tips which are prominent in excess 4.5μm emission and are located at the leading fronts of the bipolar outflow, providing compelling evidence for the existence of bow-shocks as the driving agents of the molecular outflow. By comparing our CO (2–1) observations with previously published CO (1–0) data, we find that the CO (2–1)/(1–0) line ratio increases from low (∼5 kms‑1) to moderate (∼8–12 kms‑1) velocities, and then decreases at higher velocities. This is qualitatively consistent with the scenario that the molecular outflow is driven by multiple bow-shocks. We also revisit the position-velocity diagram of the CO (1–0) data, and find two spur structures along the outflow axis, which are further evidence for the presence of multiple jet bowshocks. Finally, power-law fittings to the mass spectrum of the outflow gives power law indexes more consistent with the jet bow-shock model than the wide-angle wind model.

  14. SPARC: MASS MODELS FOR 175 DISK GALAXIES WITH SPITZER PHOTOMETRY AND ACCURATE ROTATION CURVES

    Energy Technology Data Exchange (ETDEWEB)

    Lelli, Federico; McGaugh, Stacy S. [Department of Astronomy, Case Western Reserve University, Cleveland, OH 44106 (United States); Schombert, James M., E-mail: federico.lelli@case.edu [Department of Physics, University of Oregon, Eugene, OR 97403 (United States)

    2016-12-01

    We introduce SPARC ( Spitzer Photometry and Accurate Rotation Curves): a sample of 175 nearby galaxies with new surface photometry at 3.6  μ m and high-quality rotation curves from previous H i/H α studies. SPARC spans a broad range of morphologies (S0 to Irr), luminosities (∼5 dex), and surface brightnesses (∼4 dex). We derive [3.6] surface photometry and study structural relations of stellar and gas disks. We find that both the stellar mass–H i mass relation and the stellar radius–H i radius relation have significant intrinsic scatter, while the H i   mass–radius relation is extremely tight. We build detailed mass models and quantify the ratio of baryonic to observed velocity ( V {sub bar}/ V {sub obs}) for different characteristic radii and values of the stellar mass-to-light ratio (ϒ{sub ⋆}) at [3.6]. Assuming ϒ{sub ⋆} ≃ 0.5 M {sub ⊙}/ L {sub ⊙} (as suggested by stellar population models), we find that (i) the gas fraction linearly correlates with total luminosity; (ii) the transition from star-dominated to gas-dominated galaxies roughly corresponds to the transition from spiral galaxies to dwarf irregulars, in line with density wave theory; and (iii)  V {sub bar}/ V {sub obs} varies with luminosity and surface brightness: high-mass, high-surface-brightness galaxies are nearly maximal, while low-mass, low-surface-brightness galaxies are submaximal. These basic properties are lost for low values of ϒ{sub ⋆} ≃ 0.2 M {sub ⊙}/ L {sub ⊙} as suggested by the DiskMass survey. The mean maximum-disk limit in bright galaxies is ϒ{sub ⋆} ≃ 0.7 M {sub ⊙}/ L {sub ⊙} at [3.6]. The SPARC data are publicly available and represent an ideal test bed for models of galaxy formation.

  15. INFRARED SPECTROSCOPY OF COMET 73P/SCHWASSMANN-WACHMANN 3 USING THE SPITZER SPACE TELESCOPE

    International Nuclear Information System (INIS)

    Sitko, Michael L.; Whitney, Barbara A.; Wolff, Michael J.; Lisse, Carey M.; Kelley, Michael S.; Polomski, Elisha F.; Lynch, David K.; Russell, Ray W.; Kimes, Robin L.; Harker, David E.

    2011-01-01

    We have used the Spitzer Space Telescope Infrared Spectrograph (IRS) to observe the 5-37 μm thermal emission of comet 73P/Schwassmann-Wachmann 3 (SW3), components B and C. We obtained low spectral resolution (R ∼ 100) data over the entire wavelength interval, along with images at 16 and 22 μm. These observations provided an unprecedented opportunity to study nearly pristine material from the surface and what was until recently the interior of an ecliptic comet-the cometary surface having experienced only two prior perihelion passages, and including material that was totally fresh. The spectra were modeled using a variety of mineral types including both amorphous and crystalline components. We find that the degree of silicate crystallinity, ∼35%, is somewhat lower than most other comets with strong emission features, while its abundance of amorphous carbon is higher. Both suggest that SW3 is among the most chemically primitive solar system objects yet studied in detail, and that it formed earlier or farther from the Sun than the bulk of the comets studied so far. The similar dust compositions of the two fragments suggest that these are not mineralogically heterogeneous, but rather uniform throughout their volumes. The best-fit particle size distribution for SW3B has a form dn/da ∼ a -3.5 , close to that expected for dust in collisional equilibrium, while that for SW3C has dn/da ∼ a -4.0 , as seen mostly in active comets with strong directed jets, such as C/1995 O1 Hale-Bopp. The total mass of dust in the comae plus nearby tail, extrapolated from the field of view of the IRS peak-up image arrays, is (3-5) x 10 8 kg for B and (7-9) x 10 8 kg for C. Atomic abundances derived from the spectral models indicate a depletion of O compared to solar photospheric values, despite the inclusion of water ice and gas in the models. Atomic C may be solar or slightly sub-solar, but its abundance is complicated by the potential contribution of spectrally featureless mineral

  16. SPITZER SPECTROSCOPY OF CIRCUMSTELLAR DISKS IN THE 5 Myr OLD UPPER SCORPIUS OB ASSOCIATION

    International Nuclear Information System (INIS)

    Dahm, S. E.; Carpenter, John M.

    2009-01-01

    We present mid-infrared spectra between 5.2 and 38 μm for 26 disk-bearing members of the ∼5 Myr old Upper Scorpius OB association obtained with the Infrared Spectrograph (IRS) onboard the Spitzer Space Telescope. We find clear evidence for changes in the spectral characteristics of dust emission between the early-type (B+A) and late-type (K+M) infrared excess stars. The early-type members exhibit featureless continuum excesses that become apparent redward of ∼8 μm. In contrast, 10 and 20 μm silicate features or polycyclic aromatic hydrocarbon emission are present in all but one of the late-type excess members of Upper Scorpius. The strength of silicate emission among late-type Upper Scorpius members is spectral-type dependent, with the most prominent features being associated with K5-M2-type stars. By fitting the spectral energy distributions (SED) of a representative sample of low-mass stars with accretion disk models, we find that the SEDs are consistent with models having inner disk radii ranging from ∼0.2 to 1.2 AU. Complementary high-resolution (R ∼ 33, 000) optical (λλ4800-9200) spectra for the Upper Scorpius excess stars were examined for signatures of gaseous accretion. Of the 35 infrared excess stars identified in Upper Scorpius, only seven (all late-type) exhibit definitive signatures of accretion. Mass-accretion rates for these stars were estimated to range from 10 -11 to 10 -8.9 M sun yr -1 . Compared to Class II sources in Taurus-Auriga, the disk population in Upper Scorpius exhibits reduced levels of near- and mid-infrared excess emission and an order of magnitude lower mass-accretion rates. These results suggest that the disk structure has changed significantly over the 2-4 Myr in age separating these two stellar populations. The ubiquity of depleted inner disks in the Upper Scorpius excess sample implies that such disks are a common evolutionary pathway that persists for some time.

  17. Electron Energy Distribution in Hotspots of Cygnus A:Filling the Gap with Spitzer Space Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Stawarz, L.; Cheung, C.C.; Harris, D.E.; Ostrowski, M.

    2007-03-06

    Here we present Spitzer Space Telescope imaging of Cyg A with the Infrared Array Camera at 4.5 {micro}m and 8.0 {micro}m, resulting in the detection of the high-energy tails or cut-offs in the synchrotron spectra for all four hotspots of this archetype radio galaxy. When combined with the other data collected (and re-analyzed) from the literature, our observations allow for detailed modeling of the broad-band (radio-to-X-ray) emission for the brightest spots A and D. We confirm that the X-ray flux detected previously from these features is consistent with the synchrotron self-Compton radiation for the magnetic field intensity B {approx} 170 {micro}G in spot A, and B {approx} 270 {micro}G in spot D. We also find that the energy density of the emitting electrons is most likely larger by a factor of a few than the energy density of the hotspots magnetic field. We construct energy spectra of the radiating ultrarelativistic electrons. We find that for both hotspots A and D these spectra are consistent with a broken power-law extending from at least 100MeV up to {approx} 100GeV, and that the spectral break corresponds almost exactly to the proton rest energy of {approx} 1GeV. We argue that the shape of the electron continuum most likely reflects two different regimes of the electron acceleration process taking place at mildly relativistic shocks, rather than resulting from radiative cooling and/or absorption e.ects. In this picture the protons inertia defines the critical energy for the hotspot electrons above which Fermi-type acceleration processes may play a major role, but below which the operating acceleration mechanism has to be of a different type. At energies {approx}> 100 GeV, the electron spectra cut-off/steepen again, most likely as a result of spectral aging due to radiative loss effects. We discuss several implications of the presented analysis for the physics of extragalactic jets.

  18. Electron Energy Distribution in Hotspots of Cygnus A:Filling the Gap with Spitzer Space Telescope

    International Nuclear Information System (INIS)

    Stawarz, L.; Cheung, C.C.; Harris, D.E.; Ostrowski, M.

    2007-01-01

    Here we present Spitzer Space Telescope imaging of Cyg A with the Infrared Array Camera at 4.5 (micro)m and 8.0 (micro)m, resulting in the detection of the high-energy tails or cut-offs in the synchrotron spectra for all four hotspots of this archetype radio galaxy. When combined with the other data collected (and re-analyzed) from the literature, our observations allow for detailed modeling of the broad-band (radio-to-X-ray) emission for the brightest spots A and D. We confirm that the X-ray flux detected previously from these features is consistent with the synchrotron self-Compton radiation for the magnetic field intensity B ∼ 170 (micro)G in spot A, and B ∼ 270 (micro)G in spot D. We also find that the energy density of the emitting electrons is most likely larger by a factor of a few than the energy density of the hotspots magnetic field. We construct energy spectra of the radiating ultrarelativistic electrons. We find that for both hotspots A and D these spectra are consistent with a broken power-law extending from at least 100MeV up to ∼ 100GeV, and that the spectral break corresponds almost exactly to the proton rest energy of ∼ 1GeV. We argue that the shape of the electron continuum most likely reflects two different regimes of the electron acceleration process taking place at mildly relativistic shocks, rather than resulting from radiative cooling and/or absorption e.ects. In this picture the protons inertia defines the critical energy for the hotspot electrons above which Fermi-type acceleration processes may play a major role, but below which the operating acceleration mechanism has to be of a different type. At energies ∼> 100 GeV, the electron spectra cut-off/steepen again, most likely as a result of spectral aging due to radiative loss effects. We discuss several implications of the presented analysis for the physics of extragalactic jets

  19. The CO2 Abundance in Comets C2012 K1 (PanSTARRS), C2012 K5 (LINEAR), and 290P Jager as Measured with Spitzer

    Science.gov (United States)

    McKay, Adam J.; Kelley, Michael S.P.; Cochran, Anita L.; Bodewits, Dennis; DiSanti, Michael A.; Dello Russo, Neil; Lisse, Carey M.

    2015-01-01

    Carbon dioxide is one of the most abundant ices present in comets and is therefore important for understanding cometary composition and activity. We present analysis of observations of CO2 and [O I] emission in three comets to measure the CO2 abundance and evaluate the possibility of employing observations of [O I] emission in comets as a proxy for CO2. We obtained NIR imaging sensitive to CO2 of comets C/2012 K1 (PanSTARRS), C/2012 K5 (LINEAR), and 290P/Jager with the IRAC instrument on Spitzer. We acquired observations of [O I] emission in these comets with the ARCES echelle spectrometer mounted on the 3.5-m telescope at Apache Point Observatory and observations of OH with the Swift observatory (PanSTARRS) and with Keck HIRES (Jager). The CO2/H2O ratios derived from the Spitzer images are 12.6 +/- 1.3% (PanSTARRS), 28.9 +/- 3.6% (LINEAR), and 31.3 +/- 4.2% (Jager). These abundances are derived under the assumption that contamination from CO emission is negligible. The CO2 abundance for PanSTARRS is close to the average abundance measured in comets at similar heliocentric distance to date, while the abundances measured for LINEAR and Jager are significantly larger than the average abundance. From the coma morphology observed in PanSTARRS and the assumed gas expansion velocity, we derive a rotation period for the nucleus of about 9.2 h. Comparison of H2O production rates derived from ARCES and Swift data, as well as other observations, suggest the possibility of sublimation from icy grains in the inner coma. We evaluate the possibility that the [O I] emission can be employed as a proxy for CO2 by comparing CO2/H2O ratios inferred from the [O I] lines to those measured directly by Spitzer. We find that for PanSTARRS we can reproduce the observed CO2 abundance to an accuracy of approximately 20%. For LINEAR and Jager, we were only able to obtain upper limits on the CO2 abundance inferred from the [O I] lines. These upper limits are consistent with the CO2 abundances

  20. 'Hidden messages' emerging from Afrocentric management perspectives

    Directory of Open Access Journals (Sweden)

    H. Van den Heuvel

    2008-12-01

    Full Text Available Purpose: This paper aims to examine how 'African management' discourse has emerged in South Africa. Altogether, it has stimulated debates - sometimes in controversial ways - on 'taboo issues', e.g. relating to 'cultural diversity' and 'ethnicity'. The stimulation of such debates within organisations is probably a more valuable contribution than a static, essentialised 'African identity' that it proclaims. Design/Methodology/Approach: The paper draws on a qualitative research project conducted in South Africa in 2003-2004. Its relevance lies in gaining in-depth insights into ('non-western' local management discourse. It seeks to contribute to the body of knowledge on political and cultural contexts in which South African organizations operate, and how they impact on local management perspectives, and vice versa. Findings: The research findings make clear how and under what circumstances 'African management' discourse has come about in South Africa, and how it could be interpreted. Implications: 'African management' advocates allegedly attempt to revise dominant management thinking and promote 'humane-ness' and participatory decision-making in South African organisations, in search of a contextualised management approach. Amongst others, it has produced new meanings of 'Africanness' and has opened up space for 'hidden messages', resentments and aspirations to become openly articulated. This throws another light on phenomena such as cultural diversity and ethnicity that usually tend to be 'neutralised'. This may turn out to be far healthier for blooming organisational cultures in South Africa than relentlessly hammering on prescribed 'corporate values'. Originality/Value: This paper informs the reader in detail about the emergence and evolvement of 'African management' discourse in South Africa. It is a unique attempt to develop an interpretative viewpoint on this intriguing phenomenon that offers a potentially valuable contribution in reading

  1. New Software for Ensemble Creation in the Spitzer-Space-Telescope Operations Database

    Science.gov (United States)

    Laher, Russ; Rector, John

    2004-01-01

    Some of the computer pipelines used to process digital astronomical images from NASA's Spitzer Space Telescope require multiple input images, in order to generate high-level science and calibration products. The images are grouped into ensembles according to well documented ensemble-creation rules by making explicit associations in the operations Informix database at the Spitzer Science Center (SSC). The advantage of this approach is that a simple database query can retrieve the required ensemble of pipeline input images. New and improved software for ensemble creation has been developed. The new software is much faster than the existing software because it uses pre-compiled database stored-procedures written in Informix SPL (SQL programming language). The new software is also more flexible because the ensemble creation rules are now stored in and read from newly defined database tables. This table-driven approach was implemented so that ensemble rules can be inserted, updated, or deleted without modifying software.

  2. SPITZER PARALLAX OF OGLE-2015-BLG-0966: A COLD NEPTUNE IN THE GALACTIC DISK

    Energy Technology Data Exchange (ETDEWEB)

    Street, R. A.; Bachelet, E. [LCOGT, 6740 Cortona Drive, Suite 102, Goleta, CA 93117 (United States); Udalski, A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Novati, S. Calchi [NASA Exoplanet Science Institute, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Hundertmark, M. P. G.; Jørgensen, U. G. [Niels Bohr Institute and Centre for Star and Planet Formation, University of Copenhagen, Øster Voldgade 5, DK-1350—Copenhagen K (Denmark); Zhu, W.; Gould, A. [Department of Astronomy, Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Yee, J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Tsapras, Y. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg (ZAH), D-69120 Heidelberg (Germany); Bennett, D. P. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Dominik, M. [SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews KY16 9SS (United Kingdom); Andersen, M. I. [Niels Bohr Institute and Dark Cosmology Centre, University of Copenhagen, Juliane Mariesvej 30, DK-2100—Copenhagen Ø (Denmark); Bozza, V. [Dipartimento di Fisica “E.R. Caianiello,” Università di Salerno, Via Giovanni Paolo II 132, I-84084, Fisciano (Italy); Bramich, D. M. [Qatar Environment and Energy Research Institute, Qatar Foundation, P.O. Box 5825, Doha (Qatar); Collaboration: RoboNet Project and MiNDSTEp Consortium; OGLE Project; Spitzer Team; MOA Collaboration; KMTNet Modeling Team; and others

    2016-03-10

    We report the detection of a cold Neptune m{sub planet} = 21 ± 2 M{sub ⊕} orbiting a 0.38 M{sub ⊙} M dwarf lying 2.5–3.3 kpc toward the Galactic center as part of a campaign combining ground-based and Spitzer observations to measure the Galactic distribution of planets. This is the first time that the complex real-time protocols described by Yee et al., which aim to maximize planet sensitivity while maintaining sample integrity, have been carried out in practice. Multiple survey and follow up teams successfully combined their efforts within the framework of these protocols to detect this planet. This is the second planet in the Spitzer Galactic distribution sample. Both are in the near to mid-disk and are clearly not in the Galactic bulge.

  3. Physical Properties of Asteroid (10302) 1989 ML, a Potential Spacecraft Target, from Spitzer Observations

    Science.gov (United States)

    Mueller, Michael; Harris, A. W.

    2006-09-01

    We report on results from recent Spitzer observations of near-Earth asteroid (10302) 1989 ML, which is among the lowest-ranking objects in terms of the specific momentum Δv required to reach it from Earth. It was originally considered as a target for Hayabusa and is now under consideration as a target of the planned ESA mission Don Quijote. Unfortunately, little is known about the physical properties of 1989 ML, in particular its size and albedo are unknown. Its exhibits an X type reflection spectrum, so depending on its albedo, 1989 ML may be an E, M, or P type asteroid. Provisional results from thermal-infrared observations carried out with Spitzer indicate that the albedo of 1989 ML is compatible with an M- or E-type classification. We will discuss our results and their implications for the physical properties and the rotation period of 1989 ML, and its importance as a potential spacecraft target. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.

  4. Detecting targets hidden in random forests

    Science.gov (United States)

    Kouritzin, Michael A.; Luo, Dandan; Newton, Fraser; Wu, Biao

    2009-05-01

    Military tanks, cargo or troop carriers, missile carriers or rocket launchers often hide themselves from detection in the forests. This plagues the detection problem of locating these hidden targets. An electro-optic camera mounted on a surveillance aircraft or unmanned aerial vehicle is used to capture the images of the forests with possible hidden targets, e.g., rocket launchers. We consider random forests of longitudinal and latitudinal correlations. Specifically, foliage coverage is encoded with a binary representation (i.e., foliage or no foliage), and is correlated in adjacent regions. We address the detection problem of camouflaged targets hidden in random forests by building memory into the observations. In particular, we propose an efficient algorithm to generate random forests, ground, and camouflage of hidden targets with two dimensional correlations. The observations are a sequence of snapshots consisting of foliage-obscured ground or target. Theoretically, detection is possible because there are subtle differences in the correlations of the ground and camouflage of the rocket launcher. However, these differences are well beyond human perception. To detect the presence of hidden targets automatically, we develop a Markov representation for these sequences and modify the classical filtering equations to allow the Markov chain observation. Particle filters are used to estimate the position of the targets in combination with a novel random weighting technique. Furthermore, we give positive proof-of-concept simulations.

  5. The SAGE-Spec Spitzer Legacy program: the life-cycle of dust and gas in the Large Magellanic Cloud. Point source classification - III

    Science.gov (United States)

    Jones, O. C.; Woods, P. M.; Kemper, F.; Kraemer, K. E.; Sloan, G. C.; Srinivasan, S.; Oliveira, J. M.; van Loon, J. Th.; Boyer, M. L.; Sargent, B. A.; McDonald, I.; Meixner, M.; Zijlstra, A. A.; Ruffle, P. M. E.; Lagadec, E.; Pauly, T.; Sewiło, M.; Clayton, G. C.; Volk, K.

    2017-09-01

    The Infrared Spectrograph (IRS) on the Spitzer Space Telescope observed nearly 800 point sources in the Large Magellanic Cloud (LMC), taking over 1000 spectra. 197 of these targets were observed as part of the SAGE-Spec Spitzer Legacy program; the remainder are from a variety of different calibration, guaranteed time and open time projects. We classify these point sources into types according to their infrared spectral features, continuum and spectral energy distribution shape, bolometric luminosity, cluster membership and variability information, using a decision-tree classification method. We then refine the classification using supplementary information from the astrophysical literature. We find that our IRS sample is comprised substantially of YSO and H II regions, post-main-sequence low-mass stars: (post-)asymptotic giant branch stars and planetary nebulae and massive stars including several rare evolutionary types. Two supernova remnants, a nova and several background galaxies were also observed. We use these classifications to improve our understanding of the stellar populations in the LMC, study the composition and characteristics of dust species in a variety of LMC objects, and to verify the photometric classification methods used by mid-IR surveys. We discover that some widely used catalogues of objects contain considerable contamination and others are missing sources in our sample.

  6. Enhancing the Legacy of Spitzer and Herschel with the MOSFIRE Deep Evolution Field Survey

    Science.gov (United States)

    Reddy, Naveen

    The next frontier for comprehensive galaxy surveys is the epoch at z~1.5-3.5, the peak of star formation and black hole activity. Despite the new windows that Spitzer and Herschel have opened up into the stellar and dust emission of distant galaxies and AGN during this key epoch, these studies have been limited by the lack of spectroscopic redshifts and the unknown physical conditions (e.g., metallicities, ionization) within the targeted galaxies. To realize the full potential of Spitzer and Herschel, we require a large spectroscopic survey that will: (a) efficiently assemble spectroscopic redshifts for large samples of galaxies at z=1.4-3.8; (b) yield the physical conditions, including the ionization and metallicities of these galaxies; and (c) easily obtain spectroscopic redshifts even for very dusty/confused galaxies. To this end, our team has been allocated a large program of 47 Keck nights with the multi-object near-IR spectrograph MOSFIRE to carry out the MOSFIRE Deep Evolution Field Survey (MOSDEF) in three of the Hubble CANDELS fields. MOSDEF will obtain rest-optical spectra of ~1500 galaxies at redshifts z=1.4-3.8, targeting many of the optical nebular emission lines and continuum features (e.g., [OII], [OIII], H-beta, H-alpha, [NII], [SII], 4000 Angstrom break, Ca H and K, and Mbg) that until now have been inaccessible for large samples of distant galaxies, but which are routinely used to measure the SFRs, dust attenuation, metal and gas content, and ionization and dynamical properties in nearby galaxies. MOSDEF spectroscopy provides a critical supporting role for the analysis of Spitzer and Herschel observations of distant galaxies. With this transformative dataset, we will perform the following analyses. First, we will use Spitzer and Herschel imaging, aided with spectroscopic redshifts from MOSDEF, to construct individual and mean dust SEDs for galaxies at redshifts 1.4formation and destruction processes. Our study will greatly enhance the scientific

  7. Black hole portal into hidden valleys

    International Nuclear Information System (INIS)

    Dubovsky, Sergei; Gorbenko, Victor

    2011-01-01

    Superradiant instability turns rotating astrophysical black holes into unique probes of light axions. We consider what happens when a light axion is coupled to a strongly coupled hidden gauge sector. In this case superradiance results in an adiabatic increase of a hidden sector CP-violating θ parameter in a near horizon region. This may trigger a first order phase transition in the gauge sector. As a result a significant fraction of a black hole mass is released as a cloud of hidden mesons and can be later converted into electromagnetic radiation. This results in a violent electromagnetic burst. The characteristic frequency of such bursts may range from ∼100 eV to ∼100 MeV.

  8. Religious Tolerance in the Hidden Curriculum

    Directory of Open Access Journals (Sweden)

    Kevin Nobel Kurniawan

    2018-03-01

    Full Text Available Religious intolerance is spreading within the Indonesian institution of education. Previous studies have shown that the growth of intolerance is due to the state’s regulation and pedagogical apparatus. In contrast to the previous studies, I argue that the intolerance is related to hidden curriculum applied by the institution of education.  Normatively, the hidden curriculum contains the value of religious tolerance. However, factually, the author found that there are practices of intolerance, through the formal and informal spheres in the school’s structure, within the hidden curriculum. This article applies a qualitative approach with a mixed method research strategy to analyze data collected from students, teachers, and alumnis through field observation, in-depth interview, and survey.

  9. Empowering students with the hidden curriculum.

    Science.gov (United States)

    Neve, Hilary; Collett, Tracey

    2017-11-27

    The hidden curriculum (HC) refers to unscripted, ad hoc learning that occurs outside the formal, taught curriculum and can have a powerful influence on the professional development of students. While this learning may be positive, it may conflict with that taught in the formal curriculum. Medical schools take a range of steps to address these negative effects; however, the existence and nature of the concept tends to be hidden from students. Since 2007, our medical school has incorporated into its small group programme an educational activity exploring the concept of the hidden curriculum. We undertook a qualitative evaluation of our intervention, conducting a thematic analysis of students' wiki reflections about the HC. We also analysed students' responses to a short questionnaire about the educational approach used. The majority of students felt that the HC session was important and relevant. Most appeared able to identify positive and negative HC experiences and consider how these might influence their learning and development, although a few students found the concept of the HC hard to grasp. Revealing and naming the hidden curriculum can make students aware of its existence and understand its potential impact. The hidden curriculum may also be a useful tool for triggering debate about issues such as power, patient centredness, personal resilience and career stereotypes in medicine. Supporting students to think critically about HC experiences may empower them to make active choices about which messages to take on board. The hidden curriculum can have a powerful influence on the professional development of students. © 2017 John Wiley & Sons Ltd and The Association for the Study of Medical Education.

  10. Thermal-Infrared Surveys of Near-Earth Object Diameters and Albedos with Spitzer and IRTF/MIRSI

    Science.gov (United States)

    Mommert, Michael; Trilling, David; Hora, Joseph L.; Chesley, Steven; Emery, Josh; Fazio, Giovanni; Harris, Alan W.; Moskovitz, Nick; Mueller, Michael; Smith, Howard

    2015-08-01

    More than 12000 Near-Earth Objects (NEOs) have been discovered over the past few decades and current discovery surveys find on average 4 new NEOs every night. In comparison to asteroid discovery, the physical characterization of NEOs lags far behind: measured diameters and albedos exist only for roughly 10% of all known NEOs. We describe a current and a future observing program that provide diameter and albedo measurements of a large number of NEOs.In our Spitzer Space Telescope Exploration Science program 'NEOSurvey', we are performing a fast and efficient flux-limited survey in which we measure the diameters and albedos of ~600 NEOs in a total of 710 hrs of observing time. We measure the thermal emission of our targets at 4.5 micron and combine these measurements with optical data in a thermal model. Our diameters and albedos come with highly realistic uncertainties that account for a wide range of potential asteroid properties. Our primary goal is to create a large and uniform catalog of NEO properties, including diameters, albedos, and flux density data. This catalog is publicly accessible and provides the latest results usually within 2 weeks after the observation.Starting in 2016, we will also make use of the refurbished and recommissioned MIRSI mid-infrared imaging camera on NASA's InfraRed Telescope Facility (IRTF) to derive the diameters and albedos of up to 750 NEOs over a period of 3 yrs. MIRSI will be equipped with an optical camera that will allow for simultaneous optical imaging, which will improve our thermal modeling results. With MIRSI, we will focus on newly discovered NEOs that are close to Earth and hence relatively bright.The results from both programs, together with already exisiting diameter and albedo results from the literature, will form the largest database of NEO physical properties available to date. With this data set, we will be able to refine the size distribution of small NEOs and the corresponding impact frequency, and compare the

  11. Searching for hidden sectors in multiparticle production at the LHC

    CERN Document Server

    Sanchis-Lozano, Miguel-Angel; Moreno-Picot, Salvador

    2016-01-01

    We study the impact of a hidden sector beyond the Standard Model, e.g. a Hidden Valley model, on factorial moments and cumulants of multiplicity distributions in multiparticle production with a special emphasis on the prospects for LHC results.

  12. Searching for hidden sector in multiparticle production at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Sanchis-Lozano, Miguel-Angel, E-mail: Miguel.Angel.Sanchis@ific.uv.es [Instituto de Física Corpuscular (IFIC) and Departamento de Física Teórica, University of Valencia–CSIC, 46100 Burjassot (Spain); Sarkisyan-Grinbaum, Edward K., E-mail: sedward@cern.ch [Department of Physics, CERN, 1211 Geneva 23 (Switzerland); Department of Physics, The University of Texas at Arlington, Arlington, TX 76019 (United States); Moreno-Picot, Salvador, E-mail: Salvador.Moreno@uv.es [Departamento de Informática, ETSE, University of Valencia, 46100 Burjassot (Spain)

    2016-03-10

    We study the impact of a hidden sector beyond the Standard Model, e.g. a Hidden Valley model, on factorial moments and cumulants of multiplicity distributions in multiparticle production with a special emphasis on the prospects for LHC results.

  13. EXTRASOLAR STORMS: PRESSURE-DEPENDENT CHANGES IN LIGHT-CURVE PHASE IN BROWN DWARFS FROM SIMULTANEOUS HST AND SPITZER OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hao; Apai, Dániel; Karalidi, Theodora [Department of Astronomy, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Marley, Mark S. [NASA Ames Research Center, Naval Air Station, Moffett Field, Mountain View, CA 94035 (United States); Flateau, Davin [Department of Planetary Sciences, 1629 E. University Blvd., Tucson, AZ 85721 (United States); Showman, Adam P. [Department of Planetary Sciences, University of Arizona, 1629 University Blvd., Tucson, AZ 85721 (United States); Metchev, Stanimir [The University of Western Ontario, Department of Physics and Astronomy, Centre for Planetary Science and Exploration, 1151 Richmond St., London, ON N6A 3K7 (Canada); Buenzli, Esther [Institute for Astronomy, ETH Zürich Wolfgang-Pauli-Str. 27, 8093 Zürich (Switzerland); Radigan, Jacqueline [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Artigau, Étienne [Département de Physique, Université de Montréal, C.P. 6128 Succ. Centre-ville, Montréal, QC H3C 3J7 (Canada); Lowrance, Patrick J. [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Burgasser, Adam J., E-mail: haoyang@email.arizona.edu, E-mail: apai@arizona.edu [Center for Astrophysics and Space Science, University of California, San Diego, La Jolla, CA 92093 (United States)

    2016-07-20

    We present Spitzer /Infrared Array Camera Ch1 and Ch2 monitoring of six brown dwarfs during eight different epochs over the course of 20 months. For four brown dwarfs, we also obtained simulataneous Hubble Space Telescope ( HST )/WFC3 G141 grism spectra during two epochs and derived light curves in five narrowband filters. Probing different pressure levels in the atmospheres, the multiwavelength light curves of our six targets all exhibit variations, and the shape of the light curves evolves over the timescale of a rotation period, ranging from 1.4 to 13 hr. We compare the shapes of the light curves and estimate the phase shifts between the light curves observed at different wavelengths by comparing the phase of the primary Fourier components. We use state-of-the-art atmosphere models to determine the flux contribution of different pressure layers to the observed flux in each filter. We find that the light curves that probe higher pressures are similar and in phase, but are offset and often different from the light curves that probe lower pressures. The phase differences between the two groups of light curves suggest that the modulations seen at lower and higher pressures may be introduced by different cloud layers.

  14. On the mid-infrared variability of candidate eruptive variables (exors): A comparison between Spitzer and WISE data

    Energy Technology Data Exchange (ETDEWEB)

    Antoniucci, S.; Giannini, T.; Li Causi, G.; Lorenzetti, D., E-mail: simone.antoniucci@oa-roma.inaf.it, E-mail: teresa.giannini@oa-roma.inaf.it, E-mail: gianluca.licausi@oa-roma.inaf.it, E-mail: dario.lorenzetti@oa-roma.inaf.it [INAF-Osservatorio Astronomico di Roma, via Frascati 33, I-00040 Monte Porzio (Italy)

    2014-02-10

    Aiming to statistically study the variability in the mid-IR of young stellar objects, we have compared the 3.6, 4.5, and 24 μm Spitzer fluxes of 1478 sources belonging to the C2D (Cores to Disks) legacy program with the WISE fluxes at 3.4, 4.6, and 22 μm. From this comparison, we have selected a robust sample of 34 variable sources. Their variations were classified per spectral Class (according to the widely accepted scheme of Class I/flat/II/III protostars), and per star forming region. On average, the number of variable sources decreases with increasing Class and is definitely higher in Perseus and Ophiuchus than in Chamaeleon and Lupus. According to the paradigm Class ≡ Evolution, the photometric variability can be considered to be a feature more pronounced in less evolved protostars, and, as such, related to accretion processes. Moreover, our statistical findings agree with the current knowledge of star formation activity in different regions. The 34 selected variables were further investigated for similarities with known young eruptive variables, namely the EXors. In particular, we analyzed (1) the shape of the spectral energy distribution, (2) the IR excess over the stellar photosphere, (3) magnitude versus color variations, and (4) output parameters of model fitting. This first systematic search for EXors ends up with 11 bona fide candidates that can be considered as suitable targets for monitoring or future investigations.

  15. Trawling for tor hidden services: Detection, measurement, deanonymization

    OpenAIRE

    Biryukov, Alex; Pustogarov, Ivan; Weinmann, Ralf-Philipp

    2013-01-01

    Tor is the most popular volunteer-based anonymity network consisting of over 3000 volunteer-operated relays. Apart from making connections to servers hard to trace to their origin it can also provide receiver privacy for Internet services through a feature called "hidden services". In this paper we expose flaws both in the design and implementation of Tor's hidden services that allow an attacker to measure the popularity of arbitrary hidden services, take down hidden services and deanonymize ...

  16. Hidden hyperchaos and electronic circuit application in a 5D self-exciting homopolar disc dynamo

    Science.gov (United States)

    Wei, Zhouchao; Moroz, Irene; Sprott, J. C.; Akgul, Akif; Zhang, Wei

    2017-03-01

    We report on the finding of hidden hyperchaos in a 5D extension to a known 3D self-exciting homopolar disc dynamo. The hidden hyperchaos is identified through three positive Lyapunov exponents under the condition that the proposed model has just two stable equilibrium states in certain regions of parameter space. The new 5D hyperchaotic self-exciting homopolar disc dynamo has multiple attractors including point attractors, limit cycles, quasi-periodic dynamics, hidden chaos or hyperchaos, as well as coexisting attractors. We use numerical integrations to create the phase plane trajectories, produce bifurcation diagram, and compute Lyapunov exponents to verify the hidden attractors. Because no unstable equilibria exist in two parameter regions, the system has a multistability and six kinds of complex dynamic behaviors. To the best of our knowledge, this feature has not been previously reported in any other high-dimensional system. Moreover, the 5D hyperchaotic system has been simulated using a specially designed electronic circuit and viewed on an oscilloscope, thereby confirming the results of the numerical integrations. Both Matlab and the oscilloscope outputs produce similar phase portraits. Such implementations in real time represent a new type of hidden attractor with important consequences for engineering applications.

  17. The hidden costs of nudging: Experimental evidence from reminders in fundraising

    DEFF Research Database (Denmark)

    Damgaard, Mette Trier; Gravert, Christina

    a dynamic model of donation and unsubscription behavior with limited attention. We test the model in a second field experiment. The model is estimated structurally to perform a welfare analysis. Not accounting for hidden costs overstates the welfare effects for donors by factor ten and hides potential......We document the hidden costs of a popular nudge and show how these costs distort policy making when neglected. In a field experiment with a charity, we find reminders increasing intended behavior (donations), but also increasing avoidance behavior (unsubscriptions from the mailing list). We develop...

  18. The Influence of Entrepreneurship Subject on Students’ Interest in Entrepreneurship by Hidden Curriculum as Intervening Variable

    Directory of Open Access Journals (Sweden)

    Amin Kuncoro

    2016-06-01

    Full Text Available This research aims to know the influence of entrepreneurship subject on students’ interest in entrepreneurship at Institute of Mathaliul Falah (IPMAFA in Pati by hidden curriculum as intervening variable. The research used WarpsPls analysis to test model directly and directly. Samples of the study were 30 Islamic banking students who got entrepreneurship subject and Islamic community development who did not get the entrepreneurship subject. Findings show that the entrepreneurship subject influences students’ interest in entrepreneurship and the second model test results showed that hidden curriculum is not able to become the intervening variable for students’ interest in entrepreneurship subject on students’ interest in entrepreneurship.

  19. Hidden Costs and Challenges of Servitization

    DEFF Research Database (Denmark)

    Yang, Yifan; Slepniov, Dmitrij

    of these labels, the potential benefits of servitization are often overshadowed by costs associated with it. By using the cases of Chinese and Danish manufacturing firms, this study takes a closer look at possible hidden costs of servitization and contributes to our understanding of servitization performance...

  20. The origin of the hidden supersymmetry

    Czech Academy of Sciences Publication Activity Database

    Jakubský, Vít; Nieto, L.M.; Plyushchay, M. S.

    2010-01-01

    Roč. 692, č. 1 (2010), s. 51-56 ISSN 0370-2693 R&D Projects: GA MŠk LC06002 Institutional research plan: CEZ:AV0Z10480505 Keywords : Hidden supersymmetry * Foldy-Wouthuysen transformation * Aharonov-Bohm effect Subject RIV: BE - Theoretical Physics Impact factor: 5.255, year: 2010

  1. Hidden subsidies in uranium mining and milling

    International Nuclear Information System (INIS)

    Vickery, A.

    1980-01-01

    From the environmental point of view, the regional uranium mining and milling industry imposes a heavy burden on the public. This situation is examined with regard to five hidden subsidies to the industry: lack of stewardship in land management; definition of valuable deposit; air and water contamination; lack of an effective severance tax; the regulatory bureaucracy. Four suggestions are made to improve the situation

  2. Hidden Markov Models for Human Genes

    DEFF Research Database (Denmark)

    Baldi, Pierre; Brunak, Søren; Chauvin, Yves

    1997-01-01

    We analyse the sequential structure of human genomic DNA by hidden Markov models. We apply models of widely different design: conventional left-right constructs and models with a built-in periodic architecture. The models are trained on segments of DNA sequences extracted such that they cover com...

  3. Hidden Markov models for labeled sequences

    DEFF Research Database (Denmark)

    Krogh, Anders Stærmose

    1994-01-01

    A hidden Markov model for labeled observations, called a class HMM, is introduced and a maximum likelihood method is developed for estimating the parameters of the model. Instead of training it to model the statistics of the training sequences it is trained to optimize recognition. It resembles MMI...

  4. Pruning Boltzmann networks and hidden Markov models

    DEFF Research Database (Denmark)

    Pedersen, Morten With; Stork, D.

    1996-01-01

    Boltzmann chains and hidden Markov models (HMMs), we argue that our method can be applied to HMMs as well. We illustrate pruning on Boltzmann zippers, which are equivalent to two HMMs with cross-connection links. We verify that our second-order approximation preserves the rank ordering of weight saliencies...

  5. The Hidden Cost of Buying a Computer.

    Science.gov (United States)

    Johnson, Michael

    1983-01-01

    In order to process data in a computer, application software must be either developed or purchased. Costs for modifications of the software package and maintenance are often hidden. The decision to buy or develop software packages should be based upon factors of time and maintenance. (MLF)

  6. The strength of glass, hidden damage

    NARCIS (Netherlands)

    Veer, F.A.; Rodichev, Y.M.

    2010-01-01

    The strength of float glass is a necessary engineering parameter. Determining this strength is a complex problem. Earlier results have shown that statistically bending test results are not a homogeneous group. To explain this, a theoiy of "hidden damage" is proposed. The essence of this theory is

  7. Time-reversal symmetry breaking hidden order in Sr2(Ir,Rh)O4

    Science.gov (United States)

    Jeong, Jaehong; Sidis, Yvan; Louat, Alex; Brouet, Véronique; Bourges, Philippe

    2017-04-01

    Layered 5d transition iridium oxides, Sr2(Ir,Rh)O4, are described as unconventional Mott insulators with strong spin-orbit coupling. The undoped compound, Sr2IrO4, is a nearly ideal two-dimensional pseudospin-1/2 Heisenberg antiferromagnet, similarly to the insulating parent compound of high-temperature superconducting copper oxides. Using polarized neutron diffraction, we here report a hidden magnetic order in pure and doped Sr2(Ir,Rh)O4, distinct from the usual antiferromagnetic pseudospin ordering. We find that time-reversal symmetry is broken while the lattice translation invariance is preserved in the hidden order phase. The onset temperature matches that of the odd-parity hidden order recently highlighted using optical second-harmonic generation experiments. The novel magnetic order and broken symmetries can be explained by the loop-current model, previously predicted for the copper oxide superconductors.

  8. Constraints on hidden photons from current and future observations of CMB spectral distortions

    Energy Technology Data Exchange (ETDEWEB)

    Kunze, Kerstin E.; Vázquez-Mozo, Miguel Á., E-mail: kkunze@usal.es, E-mail: Miguel.Vazquez-Mozo@cern.ch [Departamento de Física Fundamental and IUFFyM, Universidad de Salamanca, Plaza de la Merced s/n, Salamanca, 37008 Spain (Spain)

    2015-12-01

    A variety of beyond the standard model scenarios contain very light hidden sector U(1) gauge bosons undergoing kinetic mixing with the photon. The resulting oscillation between ordinary and hidden photons leads to spectral distortions of the cosmic microwave background. We update the bounds on the mixing parameter χ{sub 0} and the mass of the hidden photon m{sub γ'} for future experiments measuring CMB spectral distortions, such as PIXIE and PRISM/COrE. For 10{sup −14} eV∼< m{sub γ'}∼< 10{sup −13} eV, we find the kinetic mixing angle χ{sub 0} has to be less than 10{sup −8} at 95% CL. These bounds are more than an order of magnitude stronger than those derived from the COBE/FIRAS data.

  9. Pulling back error to the hidden-node parameter technology: Single-hidden-layer feedforward network without output weight

    OpenAIRE

    Yang, Yimin; Wu, Q. M. Jonathan; Huang, Guangbin; Wang, Yaonan

    2014-01-01

    According to conventional neural network theories, the feature of single-hidden-layer feedforward neural networks(SLFNs) resorts to parameters of the weighted connections and hidden nodes. SLFNs are universal approximators when at least the parameters of the networks including hidden-node parameter and output weight are exist. Unlike above neural network theories, this paper indicates that in order to let SLFNs work as universal approximators, one may simply calculate the hidden node paramete...

  10. Baryon states with hidden charm in the extended local hidden gauge approach

    International Nuclear Information System (INIS)

    Uchino, T.; Oset, E.; Liang, Wei-Hong

    2016-01-01

    The s-wave interaction of anti DΛ c , anti DΣ c , anti D * Λ c , anti D * Σ c and anti DΣ c * , anti D * Σ c * , is studied within a unitary coupled channels scheme with the extended local hidden gauge approach. In addition to the Weinberg-Tomozawa term, several additional diagrams via the pion exchange are also taken into account as box potentials. Furthermore, in order to implement the full coupled channels calculation, some of the box potentials which mix the vector-baryon and pseudoscalar-baryon sectors are extended to construct the effective transition potentials. As a result, we have observed six possible states in several angular momenta. Four of them correspond to two pairs of admixture states, two of anti DΣ c - anti D * Σ c with J = 1/2, and two of anti DΣ c * - anti D * Σ c * with J = 3/2. Moreover, we find a anti D * Σ c resonance which couples to the anti DΛ c channel and one spin degenerated bound state of anti D * Σ c * with J = 1/2,5/2. (orig.)

  11. Baryon states with hidden charm in the extended local hidden gauge approach

    Energy Technology Data Exchange (ETDEWEB)

    Uchino, T.; Oset, E. [Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, Departamento de Fisica Teorica y IFIC, Valencia (Spain); Liang, Wei-Hong [Guangxi Normal University, Department of Physics, Guilin (China)

    2016-03-15

    The s-wave interaction of anti DΛ{sub c}, anti DΣ{sub c}, anti D{sup *}Λ{sub c}, anti D{sup *}Σ{sub c} and anti DΣ{sub c}{sup *}, anti D{sup *}Σ{sub c}{sup *}, is studied within a unitary coupled channels scheme with the extended local hidden gauge approach. In addition to the Weinberg-Tomozawa term, several additional diagrams via the pion exchange are also taken into account as box potentials. Furthermore, in order to implement the full coupled channels calculation, some of the box potentials which mix the vector-baryon and pseudoscalar-baryon sectors are extended to construct the effective transition potentials. As a result, we have observed six possible states in several angular momenta. Four of them correspond to two pairs of admixture states, two of anti DΣ{sub c} - anti D{sup *}Σ{sub c} with J = 1/2, and two of anti DΣ{sub c}{sup *} - anti D{sup *}Σ{sub c}{sup *} with J = 3/2. Moreover, we find a anti D{sup *}Σ{sub c} resonance which couples to the anti DΛ{sub c} channel and one spin degenerated bound state of anti D{sup *}Σ{sub c}{sup *} with J = 1/2,5/2. (orig.)

  12. The X-ray properties of five galactic supernova remnants detected by the Spitzer glimpse survey

    International Nuclear Information System (INIS)

    Pannuti, Thomas G.; Moffitt, William P.; Rho, Jeonghee; Heinke, Craig O.

    2014-01-01

    We present a study of the X-ray properties of five Galactic supernova remnants (SNRs)—Kes 17 (G304.6+0.1), G311.5–0.3, G346.6–0.2, CTB 37A (G348.5+0.1), and G348.5–0.0—that were detected in the infrared by Reach et al. in an analysis of data from the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) that was conducted by the Spitzer Space Telescope. We present and analyze archival ASCA observations of Kes 17, G311.5–0.3, and G346.6–0.2, archival XMM-Newton observations of Kes 17, CTB 37A, and G348.5–0.0, and an archival Chandra observation of CTB 37A. All of the SNRs are clearly detected in the X-ray except possibly G348.5–0.0. Our study reveals that the four detected SNRs all feature center-filled X-ray morphologies and that the observed emission from these sources is thermal in all cases. We argue that these SNRs should be classified as mixed-morphology SNRs (MM SNRs); our study strengthens the correlation between MM SNRs and SNRs interacting with molecular clouds and suggests that the origin of MM SNRs may be due to the interactions between these SNRs and adjacent clouds. Our ASCA analysis of G311.5–0.3 reveals for the first time X-ray emission from this SNR: the X-ray emission is center-filled within the radio and infrared shells and thermal in nature (kT ∼ 0.98 keV), thus motivating its classification as an MM SNR. We find considerable spectral variations in the properties associated with the plasmas of the other X-ray-detected SNRs, such as a possible overabundance of magnesium in the plasma of Kes 17. Our new results also include the first detailed spatially resolved spectroscopic study of CTB 37A using Chandra as well as a spectroscopic study of the discrete X-ray source CXOU J171428.5–383601, which may be a neutron star associated with CTB 37A. Finally, we also estimate such properties as electron density n e , radiative age t rad and swept-up mass M X for each of the four X-ray-detected SNRs. Each of these values

  13. Spitzer/IRS Observations Of Multiple Main-Belt And Binary Near-Earth Asteroids

    Science.gov (United States)

    Enriquez, J. Emilio; Marchis, F.; Emery, J. P.; Im, S.

    2010-10-01

    Since the discovery of Ida's companion in 1993, 195 companions of asteroids have been discovered. To understand the formation process of these interesting bodies, their physical properties such as their bulk density, size, shape, and surface roughness need to be determined. During the Spitzer Cycle-4, we obtained IRS thermal emission spectra (5-42 um) of 23 known binary systems. The majority of asteroids are from the main-belt (16), while the rest are NEOs (7). After extracting the thermal spectra, we used a modified Standard Thermal Model (STM) to calculate their equivalent diameter (from 0.8 km to 237 km), their albedo (from 0.04 for C-type to 0.394 for a V-type) and their beaming factor related to the surface roughness and thermal inertia. We derive their emissivity spectra, which is useful to detect silicate features. Combining these measurements with 3D-models of these multiple asteroid systems obtained by lightcurve inversion, we should be able to derive an accurate estimate of their bulk-density and contrast them with their taxonomic classes. Preliminary studies by Marchis et al. (2008)1, suggested a relationship between bulk density and the taxonomic class of asteroids, which varies from 0.9 g/cc for C-complex to 2.4 g/cc for S-complex asteroids. The National Science Foundation supported this research under award number AAG-0807468. It was conducted with the Spitzer space telescope, which is operated by JPL under a contract with NASA. 1 Marchis et al. , 2008, "Mid-infrared Spectra of Binary Asteroids With Spitzer/IRS", 40th DPS Meeting, Bulletin of the American Astronomical Society, 40, 508

  14. Multiple Asteroid Systems: Dimensions and Thermal Properties from Spitzer Space Telescope and Ground-based Observations

    Science.gov (United States)

    Marchis, F.; Enriquez, J. E.; Emery, J. P.; Mueller, M.; Baek, M.; Pollock, J.; Assafin, M.; Matins, R. Vieira; Berthier, J.; Vachier, F.; hide

    2012-01-01

    We collected mid-IR spectra from 5.2 to 38 microns using the Spitzer Space Telescope Infrared Spectrograph of 28 asteroids representative of all established types of binary groups. Photometric light curves were also obtained for 14 of them during the Spitzer observations to provide the context of the observations and reliable estimates of their absolute magnitudes. The extracted mid-IR spectra were analyzed using a modified standard thermal model (STM) and a thermophysical model (TPM) that takes into account the shape and geometry of the large primary at the time of the Spitzer observation. We derived a reliable estimate of the size, albedo, and beaming factor for each of these asteroids, representing three main taxonomic groups: C, S, and X. For large (volume-equivalent system diameter Deq > 130 km) binary asteroids, the TPM analysis indicates a low thermal inertia (Lambda thermally insulating regolith. The smaller (surface-equivalent system diameter Deff < 17 km) asteroids also show some emission lines of minerals, but they are significantly weaker, consistent with regoliths with coarser grains, than those of the large binary asteroids. The average bulk densities of these multiple asteroids vary from 0.7-1.7 g/cu cm (P-, C-type) to approx. 2 g/cu cm (S-type). The highest density is estimated for the M-type (22) Kalliope (3.2 +/- 0.9 g/cu cm). The spectral energy distributions (SEDs) and emissivity spectra, made available as a supplement document, could help to constrain the surface compositions of these asteroids.

  15. NA62: Hidden Sector Physics

    CERN Document Server

    Cesarotti, Carissa Joyce

    2016-01-01

    Modern experimental physics is often probing for new physics by either finding deviations from predictions on extremely precise measurements, or by looking for a new signal that cannot be explained with existing models. The NA62 experiment at CERN does the former by measuring the ultra-rare decay $K^+ \\rightarrow \\pi^+ \

  16. Observations of V592 Cassiopeiae with the Spitzer Space Telescope - Dust in the Mid-Infrared

    OpenAIRE

    Hoard, D. W.; Kafka, Stella; Wachter, Stefanie; Howell, Steve B.; Brinkworth, Carolyn S.; Ciardi, David R.; Szkody, Paula; Belle, Kunegunda; Froning, Cynthia; van Belle, Gerard

    2008-01-01

    We present the ultraviolet-optical-infrared spectral energy distribution of the low inclination novalike cataclysmic variable (CV) V592 Cassiopeiae, including new mid-infrared observations from 3.5 to 24 μm obtained with the Spitzer Space Telescope. At wavelengths shortward of 8 μm, the spectral energy distribution of V592 Cas is dominated by the steady state accretion disk, but there is flux density in excess of the summed stellar components and accretion disk at longer wavelengths. Reproduc...

  17. Spitzer 3.6 and 5.8 micron Monitoring of the Seyfert 1 NGC 4051

    Science.gov (United States)

    Gorjian, Varoujan; Adkins, J.; Borders, K.; Kelly, S.; Martin, C.; Mendez, B.; Paradis, J.; Perreira, V.; Pittman, P.; Sepulveda, B.; NGC 4051 Monitoring Group

    2009-01-01

    We used the Spitzer Space Telescope Infrared Array Camera (IRAC) to monitor the Seyfert 1 active galactic nucleus NGC 4051. We took data at 3.6 and 5.8 microns every day for 10 days in June 2008. We also observed in the optical at B, V, and R bands starting a month before the IRAC observations with various ground based observatories, though we were unable to achieve daily coverage. We will present the IR and optical light curves and will search for correlated variability that may be evidence of dust reverberation. For the education and public outreach component of this program please see Sepulveda et al.

  18. REPEATABILITY OF SPITZER/IRAC EXOPLANETARY ECLIPSES WITH INDEPENDENT COMPONENT ANALYSIS

    International Nuclear Information System (INIS)

    Morello, G.; Waldmann, I. P.; Tinetti, G.

    2016-01-01

    The research of effective and reliable detrending methods for Spitzer data is of paramount importance for the characterization of exoplanetary atmospheres. To date, the totality of exoplanetary observations in the mid- and far-infrared, at wavelengths >3 μm, have been taken with Spitzer. In some cases, in past years, repeated observations and multiple reanalyses of the same data sets led to discrepant results, raising questions about the accuracy and reproducibility of such measurements. Morello et al. (2014, 2015) proposed a blind-source separation method based on the Independent Component Analysis of pixel time series (pixel-ICA) to analyze InfraRed Array Camera (IRAC) data, obtaining coherent results when applied to repeated transit observations previously debated in the literature. Here we introduce a variant to the pixel-ICA through the use of wavelet transform, wavelet pixel-ICA, which extends its applicability to low-signal-to-noise-ratio cases. We describe the method and discuss the results obtained over 12 eclipses of the exoplanet XO3b observed during the “Warm Spitzer” era in the 4.5 μm band. The final results are reported, in part, also in Ingalls et al. (2016), together with results obtained with other detrending methods, and over 10 synthetic eclipses that were analyzed for the “IRAC Data Challenge 2015.” Our results are consistent within 1σ with the ones reported in Wong et al. (2014) and with most of the results reported in Ingalls et al. (2016), which appeared on arXiv while this paper was under review. Based on many statistical tests discussed in Ingalls et al. (2016), the wavelet pixel-ICA method performs as well as or better than other state-of-art methods recently developed by other teams to analyze Spitzer/IRAC data, and, in particular, it appears to be the most repeatable and the most reliable, while reaching the photon noise limit, at least for the particular data set analyzed. Another strength of the ICA approach is its highest

  19. Minimal spontaneously broken hidden sector and its impact on Higgs boson physics at the CERN Large Hadron Collider

    International Nuclear Information System (INIS)

    Schabinger, Robert; Wells, James D.

    2005-01-01

    Little experimental data bears on the question of whether there is a spontaneously broken hidden sector that has no Standard Model quantum numbers. Here we discuss the prospects of finding evidence for such a hidden sector through renormalizable interactions of the Standard Model Higgs boson with a Higgs boson of the hidden sector. We find that the lightest Higgs boson in this scenario has smaller rates in standard detection channels, and it can have a sizeable invisible final state branching fraction. Details of the hidden sector determine whether the overall width of the lightest state is smaller or larger than the Standard Model width. We compute observable rates, total widths and invisible decay branching fractions within the general framework. We also introduce the 'A-Higgs Model', which corresponds to the limit of a hidden sector Higgs boson weakly mixing with the Standard Model Higgs boson. This model has only one free parameter in addition to the mass of the light Higgs state and it illustrates most of the generic phenomenology issues, thereby enabling it to be a good benchmark theory for collider searches. We end by presenting an analogous supersymmetry model with similar phenomenology, which involves hidden sector Higgs bosons interacting with MSSM Higgs bosons through D-terms

  20. The Hidden Costs of Downsizing

    OpenAIRE

    Heinz, Matthias; Drzensky, Frank

    2013-01-01

    We analyze whether a principal s decision to layoff an agent affects the performance of the surviving agents. To study the impact of the decision in isolation, we conducted an experimental principal-agent game. We find that agents reduce their performance by 37% as a response to the decision. Heterogeneity in principals decisions can largely be explained by different beliefs about how agents react to layoffs.

  1. The Hidden Costs of Control

    OpenAIRE

    Falk, Armin; Kosfeld, Michael

    2005-01-01

    In this paper we analyze the behavioral consequences of control on motivation. We study a simple experimental principal-agent game, where the principal decides whether he controls the agent by implementing a minimum performance requirement before the agent chooses a productive activity. Our main finding is that a principal's decision to control has a negative impact on the agent's motivation. While there is substantial individual heterogeneity among agents, most agents reduce their performanc...

  2. What do dolphins (Tursiops truncatus) understand about hidden objects?

    Science.gov (United States)

    Jaakkola, Kelly; Guarino, Emily; Rodriguez, Mandy; Erb, Linda; Trone, Marie

    2010-01-01

    Object permanence, the ability to mentally represent and reason about objects that have disappeared from view, is a fundamental cognitive skill that has been extensively studied in human infants and terrestrial animals, but not in marine animals. A series of four experiments examined this ability in bottlenose dolphins (Tursiops truncatus). After being trained on a "find the object" game, dolphins were tested on visible and invisible displacement tasks, and transpositions. In Experiments 1 and 2, dolphins succeeded at visible displacements, but not at invisible displacements or transpositions. Experiment 3 showed that they were able to pass an invisible displacement task in which a person's hand rather than a container was used as the displacement device. However, follow-up controls suggested they did so by learning local rules rather than via a true representation of the movement of hidden objects. Experiment 4 demonstrated that the dolphins did not rely on such local rules to pass visible displacement tasks. Thus, like many terrestrial animals, dolphins are able to succeed on visible displacement tasks, but seem unable to succeed on tasks requiring the tracking of hidden objects.

  3. PLANETARY NEBULAE DETECTED IN THE SPITZER SPACE TELESCOPE GLIMPSE II LEGACY SURVEY

    International Nuclear Information System (INIS)

    Zhang Yong; Sun Kwok

    2009-01-01

    We report the result of a search for the infrared counterparts of 37 planetary nebulae (PNs) and PN candidates in the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire II (GLIMPSE II) survey. The photometry and images of these PNs at 3.6, 4.5, 5.8, 8.0, and 24 μm, taken through the Infrared Array Camera (IRAC) and the Multiband Imaging Photometer for Spitzer (MIPS), are presented. Most of these nebulae are very red and compact in the IRAC bands, and are found to be bright and extended in the 24 μm band. The infrared morphology of these objects are compared with Hα images of the Macquarie-AAO-Strasbourg (MASH) and MASH II PNs. The implications for morphological difference in different wavelengths are discussed. The IRAC data allow us to differentiate between PNs and H II regions and be able to reject non-PNs from the optical catalog (e.g., PNG 352.1 - 00.0). Spectral energy distributions are constructed by combing the IRAC and MIPS data with existing near-, mid-, and far-IR photometry measurements. The anomalous colors of some objects allow us to infer the presence of aromatic emission bands. These multi-wavelength data provide useful insights into the nature of different nebular components contributing to the infrared emission of PNs.

  4. Spitzer IRAC mid-infrared photometry of 500-750 brown dwarf

    Energy Technology Data Exchange (ETDEWEB)

    Saumon, Didier [Los Alamos National Laboratory; Leggett, Sandy K [GEMINI OBSERVATORY; Albert, Loic [CFH TELESCOPE; Artigau, Etienne [U OF MONTREAL; Burningham, Ben [HERTFORDSHIRE U; Delfosse, Xavier [OBS. GRENOBLE; Delorme, Philippe [ST. ANDREWS U.; Forveille, Thierry [OBS. GRENOBLE; Lucas, Philip W [HERTFORDSHIRE U; Marley, Mark S [NASA AMES; Pinfield, David J [HERTFORDSHIRE U.; Reyle, Celine [OBS. BESANCON; Smart, Richard L [OSS. ASTRON, TORINO; Warren, Stephen J [IMPERIAL COLLEGE LONDON

    2010-10-26

    Mid-infrared data, including Spitzer warm-IRAC [3.6] and [4.5] photometry, is critical for understanding the cold population of brown dwarfs now being found, objects which have more in common with planets than stars. As effective temperature (T{sub eff}) drops from 800K to 400K, the fraction of flux emitted beyond 3 {mu}m increases rapidly, from about 40% to > 75%. This rapid increase makes a color like H-[4.5] a very sensitive temperature indicator, and it can be combined with a gravity- and metallicity-sensitive color like H-K to constrain all three of these fundamental properties, which in turn gives us mass and age for these slowly cooling objects. Determination of mid-infrared color trends also allows better exploitation of the WISE mission by the community. We use new Spitzer Cycle 6 IRAC photometry, together with published data, to present trends of color with type for L0 to T10 dwarfs. We also use the atmospheric and evolutionary models of Saumon and Marley to investigate the masses and ages of 13 very late-type T dwarfs, which have H-[4.5] > 3.2 and T{sub eff} {approx} 500K to 750K.

  5. SPITZER MICROLENS MEASUREMENT OF A MASSIVE REMNANT IN A WELL-SEPARATED BINARY

    Energy Technology Data Exchange (ETDEWEB)

    Shvartzvald, Y.; Bryden, G.; Henderson, C. B. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Udalski, A. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Gould, A.; Fausnaugh, M.; Gaudi, B. S.; Pogge, R. W.; Wibking, B.; Zhu, W. [Department of Astronomy, Ohio State University, 140 W. 18th Avenue, Columbus, OH 43210 (United States); Han, C. [Department of Physics, Chungbuk National University, Cheongju 361-763 (Korea, Republic of); Bozza, V.; Novati, S. Calchi [Dipartimento di Fisica “E. R. Caianiello,” Università di Salerno, Via Giovanni Paolo II, I-84084 Fisciano (Italy); Friedmann, M. [School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel); Hundertmark, M. [Niels Bohr Institute and Centre for Star and Planet Formation, University of Copenhagen, Øster Voldgade 5, DK-1350 Copenhagen K (Denmark); Beichman, C. [NASA Exoplanet Science Institute, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Carey, S. [Spitzer, Science Center, MS 220-6, California Institute of Technology, Pasadena, CA (United States); Kerr, T.; Varricatt, W. [UKIRT, 660 N. Aohoku Place, University Park, Hilo, HI 96720 (United States); Yee, J. C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Collaboration: and; Spitzer team; OGLE group; KMTNet group; Wise group; RoboNet; MiNDSTEp; and others

    2015-12-01

    We report the detection and mass measurement of a binary lens OGLE-2015-BLG-1285La,b, with the more massive component having M{sub 1} > 1.35 M{sub ⊙} (80% probability). A main-sequence star in this mass range is ruled out by limits on blue light, meaning that a primary in this mass range must be a neutron star (NS) or black hole (BH). The system has a projected separation r{sub ⊥} = 6.1 ± 0.4 AU and lies in the Galactic bulge. These measurements are based on the “microlens parallax” effect, i.e., comparing the microlensing light curve as seen from Spitzer, which lay at 1.25 AU projected from Earth, to the light curves from four ground-based surveys, three in the optical and one in the near-infrared. Future adaptive optics imaging of the companion by 30 m class telescopes will yield a much more accurate measurement of the primary mass. This discovery both opens the path and defines the challenges to detecting and characterizing BHs and NSs in wide binaries, with either dark or luminous companions. In particular, we discuss lessons that can be applied to future Spitzer and Kepler K2 microlensing parallax observations.

  6. Spitzer Observations of Dust Destruction in the Puppis A Supernova Remnant

    Science.gov (United States)

    Arendt, Richard G.; Dweek, Eli; Blair, William P.; Ghavamian, Parviz; Hwang, Una; Long, Knox X.; Petre, Robert; Rho, Jeonghee; Winkler, P. Frank

    2010-01-01

    The interaction of the Puppis A supernova remnant (SNR) with a neighboring molecular cloud provides a unique opportunity to measure the amount of grain destruction in an SNR shock. Spitzer Space Telescope MIPS imaging of the entire SNR at 24, 70, and 160 micrometers shows an extremely good correlation with X-ray emission, indicating that the SNR's IR radiation is dominated by the thermal emission of swept-up interstellar dust, collisionally heated by the hot shocked gas. Spitzer IRS spectral observations targeted both the Bright Eastern Knot (BEK) of the SNR where a small cloud has been engulfed by the supernova blast wave and outlying portions of the associated molecular cloud that are yet to be hit by the shock front. Modeling the spectra from both regions reveals the composition and the grain size distribution of the interstellar dust, both in front of and behind the SNR shock front. The comparison shows that the ubiquitous polycyclic aromatic hydrocarbons of the interstellar medium are destroyed within the BEK, along with nearly 25% of the mass of graphite and silicate dust grains.

  7. A Spitzer Infrared Radius for the Transiting Extrasolar Planet HD 209458 b

    Science.gov (United States)

    Richardson, L. Jeremy; Harrington, Joseph; Seager, Sara; Deming, Drake

    2007-01-01

    We have measured the infrared transit of the extrasolar planet HD 209458 b using the Spitzer Space Telescope. We observed two primary eclipse events (one partial and one complete transit) using the 24 micrometer array of the Multiband Imaging Photometer for Spitzer (MIPS). We analyzed a total of 2392 individual images (10-second integrations) of the planetary system, recorded before, during, and after transit. We perform optimal photometry on the images and use the local zodiacal light as a short-term flux reference. At this long wavelength, the transit curve has a simple box-like shape, allowing robust solutions for the stellar and planetary radii independent of stellar limb darkening, which is negligible at 24 micrometers. We derive a stellar radius of R(sub *) = 1.06 plus or minus 0.07 solar radius, a planetary radius of R(sub p) = 1.26 plus or minus 0.08 R(sub J), and a stellar mass of 1.17 solar mass. Within the errors, our results agree with the measurements at visible wavelengths. The 24 micrometer radius of the planet therefore does not differ significantly compared to the visible result. We point out the potential for deriving extrasolar transiting planet radii to high accuracy using transit photometry at slightly shorter IR wavelengths where greater photometric precision is possible.

  8. VizieR Online Data Catalog: Spitzer observations of Taurus members (Luhman+, 2010)

    Science.gov (United States)

    Luhman, K. L.; Allen, P. R.; Espaillat, C.; Hartmann, L.; Calvet, N.

    2016-03-01

    For our census of the disk population in Taurus, we use images at 3.6, 4.5, 5.8, and 8.0um obtained with Spitzer's Infrared Array Camera (IRAC) and images at 24um obtained with the Multiband Imaging Photometer for Spitzer (MIPS). The cameras produced images with FWHM=1.6"-1.9" from 3.6 to 8.0um and FWHM=5.9" at 24um. The available data were obtained through Guaranteed Time Observations for PID = 6, 36, 37 (G. Fazio), 53 (G. Rieke), 94 (C. Lawrence), 30540 (G. Fazio, J. Houck), and 40302 (J. Houck), Director's Discretionary Time for PID = 462 (L. Rebull), Legacy programs for PID = 139, 173 (N. Evans), and 30816 (D. Padgett), and General Observer programs for PID = 3584 (D. Padgett), 20302 (P. Andre), 20386 (P. Myers), 20762 (J. Swift), 30384 (T. Bourke), 40844 (C. McCabe), and 50584 (D. Padgett). The IRAC and MIPS observations were performed through 180 and 137 Astronomical Observation Requests (AORs), respectively. The characteristics of the resulting images are summarized in Tables 1 and 2. (6 data files).

  9. SPITZER OBSERVATIONS OF DUST DESTRUCTION IN THE PUPPIS A SUPERNOVA REMNANT

    International Nuclear Information System (INIS)

    Arendt, Richard G.; Dwek, Eli; Blair, William P.; Hwang, Una; Ghavamian, Parviz; Long, Knox S.; Petre, Robert; Rho, Jeonghee; Winkler, P. Frank

    2010-01-01

    The interaction of the Puppis A supernova remnant (SNR) with a neighboring molecular cloud provides a unique opportunity to measure the amount of grain destruction in an SNR shock. Spitzer Space Telescope MIPS imaging of the entire SNR at 24, 70, and 160 μm shows an extremely good correlation with X-ray emission, indicating that the SNR's IR radiation is dominated by the thermal emission of swept-up interstellar dust, collisionally heated by the hot shocked gas. Spitzer IRS spectral observations targeted both the Bright Eastern Knot (BEK) of the SNR where a small cloud has been engulfed by the supernova blast wave and outlying portions of the associated molecular cloud that are yet to be hit by the shock front. Modeling the spectra from both regions reveals the composition and the grain size distribution of the interstellar dust, both in front of and behind the SNR shock front. The comparison shows that the ubiquitous polycyclic aromatic hydrocarbons of the interstellar medium are destroyed within the BEK, along with nearly 25% of the mass of graphite and silicate dust grains.

  10. Sensitive Spitzer Photometry of Supermassive Black Holes at the Final Stage of Adolescence

    Science.gov (United States)

    Shemmer, Ohad; Netzer, Hagai; Mor, Rivay; Trakhtenbrot, Benny

    2011-05-01

    We propose to obtain sensitive Spitzer snapshot observations of a unique sample of 35 Sloan Digital Sky Survey quasars at redshift 4.8 for which we obtained reliable, Mg II-based determinations of the supermassive black hole (SMBH) mass and normalized accretion rate (L/L_Edd). These quasars appear to mark the final stage of SMBH `adolescence' in the history of the Universe as their SMBHs are significantly less massive and their L/L_Edd values are significantly higher with respect to their counterparts at lower redshifts. Our observations will provide both 1) deep coverage of the fields around these quasars which will be utilized as crucial priors for our approved Herschel/SPIRE observations of these sources, and 2) coverage of the rest-frame optical SEDs of these fast accreting quasars. The results will maximize our ability to measure the star-formation rate in the host galaxies of these quasars using Herschel. We will thus be able to investigate correlations between SMBH growth and star-forming activity in the early Universe. The Spitzer photometry will also provide invaluable information about the shape of the rest-frame optical continuum in these quasars which will be used to search for extreme disk properties that may be signatures of the remarkably high accretion rates in these sources.

  11. Extended abstract of a hidden agenda

    Energy Technology Data Exchange (ETDEWEB)

    Goguen, J.; Malcolm, G. [Oxford Univ. (United Kingdom)

    1996-12-31

    The initial goal of our hidden research programme was both straightforward and ambitious: give a semantics for software engineering, and in particular for the object paradigm, supporting correctness proofs that are as simple and mechanical as possible. This emphasizes proofs rather than models, and thus suggests an equational approach, rather than one based on higher order logic, denotational semantics, or any kind of model, because equational proofs achieve maximal simplicity and mechanization, and yet are fully expressive. We introduce powerful coinduction techniques for proving behavioral properties of complex systems. We make the no doubt outrageous claim that our hidden approach gives simpler proofs than other formalisms; this is because we exploit algebraic structure that most other approaches discard.

  12. Laser experiments explore the hidden sector

    International Nuclear Information System (INIS)

    Ahlers, M.

    2007-11-01

    Recently, the laser experiments BMV and GammeV, searching for light shining through walls, have published data and calculated new limits on the allowed masses and couplings for axion-like particles. In this note we point out that these experiments can serve to constrain a much wider variety of hidden-sector particles such as, e.g., minicharged particles and hidden-sector photons. The new experiments improve the existing bounds from the older BFRT experiment by a factor of two. Moreover, we use the new PVLAS constraints on a possible rotation and ellipticity of light after it has passed through a strong magnetic field to constrain pure minicharged particle models. For masses -7 times the electron electric charge. This is the best laboratory bound and comparable to bounds inferred from the energy spectrum of the cosmic microwave background. (orig.)

  13. Hidden Costs and the Role of Modularity

    DEFF Research Database (Denmark)

    Larsen, Marcus M.

    2013-01-01

    This paper addresses estimation errors in strategic decision-making processes due to hidden costs. While previous research has investigated the antecedents of hidden costs, this paper investigates performance consequences. Using unique data on 221 offshoring implementations, it is argued...... that the inability to effectively estimate the costs of implementing an activity in a foreign location has a negative impact on the process performance of that activity. Performance is deterred as operations are likely to be disrupted by opportunity costs and managerial responses. However, this relationship...... is mitigated by the degree of modularity in the activity as it reduces the need for costly coordination in offshoring. This paper contributes to research on offshoring and strategic decision-making by emphasizing the importance of organizational design and of estimating the costs of internal organizational...

  14. Quantum mechanics and hidden superconformal symmetry

    Science.gov (United States)

    Bonezzi, R.; Corradini, O.; Latini, E.; Waldron, A.

    2017-12-01

    Solvability of the ubiquitous quantum harmonic oscillator relies on a spectrum generating osp (1 |2 ) superconformal symmetry. We study the problem of constructing all quantum mechanical models with a hidden osp (1 |2 ) symmetry on a given space of states. This problem stems from interacting higher spin models coupled to gravity. In one dimension, we show that the solution to this problem is the Vasiliev-Plyushchay family of quantum mechanical models with hidden superconformal symmetry obtained by viewing the harmonic oscillator as a one dimensional Dirac system, so that Grassmann parity equals wave function parity. These models—both oscillator and particlelike—realize all possible unitary irreducible representations of osp (1 |2 ).

  15. A masking index for quantifying hidden glitches

    OpenAIRE

    Berti-Equille, Laure; Loh, J. M.; Dasu, T.

    2015-01-01

    Data glitches are errors in a dataset. They are complex entities that often span multiple attributes and records. When they co-occur in data, the presence of one type of glitch can hinder the detection of another type of glitch. This phenomenon is called masking. In this paper, we define two important types of masking and propose a novel, statistically rigorous indicator called masking index for quantifying the hidden glitches. We outline four cases of masking: outliers masked by missing valu...

  16. Hidden Costs of Control in Social Groups

    OpenAIRE

    Wiederhold, Simon; Riener, Gerhard

    2012-01-01

    This paper investigates the role of social identity in reactions to control. We propose a simple principal-agent model with control that incorporates the existence of social groups. Our laboratory experiment shows that, in contrast to no-group agents, agents in social groups (i) perform better; (ii) expect less control; (iii) do not reciprocate when facing less control than expected; (iv) decrease their performance substantially when actual control exceeds their expectation. Hidden costs of c...

  17. Completing Quantum Mechanics with Quantized Hidden Variables

    OpenAIRE

    van Enk, S. J.

    2015-01-01

    I explore the possibility that a quantum system S may be described completely by the combination of its standard quantum state $|\\psi\\rangle$ and a (hidden) quantum state $|\\phi\\rangle$ (that lives in the same Hilbert space), such that the outcome of any standard projective measurement on the system S is determined once the two quantum states are specified. I construct an algorithm that retrieves the standard quantum-mechanical probabilities, which depend only on $|\\psi\\rangle$, by assuming t...

  18. Hidden histories: challenges for pedagogy and participation

    OpenAIRE

    Morrice, Linda

    2013-01-01

    Higher Education has become and an increasingly diverse and globalised system in which the binaries between ‘traditional’ and ‘non-traditional’ students, exclusion and inclusion have less resonance and analytical purchase. Drawing on research with refugees Linda will suggest that higher education can be marked simultaneously by belonging and recognition, deficit and exclusion. Complex differences and inequalities remain hidden and unspoken, raising new questions and challenges for pedagogy an...

  19. Hidden Information In Early Visual Processing

    Science.gov (United States)

    Nishihara, H. K.

    1983-05-01

    A definition of scale-specific structure follows from the work of Marr and Poggio on zero-crossings in gaussian-bandpass-filtered images. This paper presents several examples which illustrate the potential value of scale-specific structure for recognition, inspection, and correspondence related tasks. The suitability of the approach for practical systems is discussed, and a recent result suggesting the importance of this "hidden" information to human stereo vision is presented.

  20. Lepton mixing from the hidden sector

    Science.gov (United States)

    Ludl, P. O.; Smirnov, A. Yu.

    2015-10-01

    Experimental results indicate a possible relation between the lepton and quark mixing matrices of the form UPMNS≈VCKM†UX , where UX is a matrix with special structure related to the mechanism of neutrino mass generation. We propose a framework which can realize such a relation. The main ingredients of the framework are the double seesaw mechanism, SO(10) grand unification and a hidden sector of theory. The latter is composed of singlets (fermions and bosons) of the grand unified theory (GUT) symmetry with masses between the GUT and Planck scale. The interactions in this sector obey certain symmetries Ghidden. We explore the conditions under which symmetries Ghidden can produce flavor structures in the visible sector. Here the key elements are the basis-fixing symmetry and mediators which communicate information about properties of the hidden sector to the visible one. The interplay of SO(10) symmetry, basis-fixing symmetry identified as Z2×Z2 and Ghidden can lead to the required form of UX. A different kind of new physics is responsible for generation of the CKM mixing. We present the simplest realizations of the framework which differ by nature of the mediators and by symmetries of the hidden sector.

  1. Genuinely Multipartite Entangled Quantum States with Fully Local Hidden Variable Models and Hidden Multipartite Nonlocality

    Science.gov (United States)

    Bowles, Joseph; Francfort, Jérémie; Fillettaz, Mathieu; Hirsch, Flavien; Brunner, Nicolas

    2016-04-01

    The relation between entanglement and nonlocality is discussed in the case of multipartite quantum systems. We show that, for any number of parties, there exist genuinely multipartite entangled states that admit a fully local hidden variable model, i.e., where all parties are separated. Hence, although these states exhibit the strongest form of multipartite entanglement, they cannot lead to Bell inequality violation considering general nonsequential local measurements. Then, we show that the nonlocality of these states can nevertheless be activated using sequences of local measurements, thus revealing genuine multipartite hidden nonlocality.

  2. DEEP SPITZER 24 μm COSMOS IMAGING. I. THE EVOLUTION OF LUMINOUS DUSTY GALAXIES-CONFRONTING THE MODELS

    International Nuclear Information System (INIS)

    Le Floc'h, Emeric; Ilbert, Olivier; Riguccini, Laurie; Kartaltepe, Jeyhan; Sanders, David; Aussel, Herve; Feruglio, Chiara; Frayer, David T.; Salvato, Mara; Capak, Peter; Scoville, Nick; Arnouts, Stephane; Surace, Jason; Sheth, Kartik; Yan Lin; Rodighiero, Giulia; Heinis, Sebastien; McCracken, Henry Joy; Thompson, David; Koekemoer, Anton

    2009-01-01

    We present the first results obtained from the identification of ∼30,000 sources in the Spitzer/24 μm observations of the COSMOS field at S 24μm ∼> 80 μJy. Using accurate photometric redshifts (σ z ∼ 0.12 at z ∼ 2 for 24 μm sources with i + ∼ 2) contribute only marginally to the cosmic infrared background. Assuming flux-limited selections at optical wavelengths, we also find that the fraction of i + -band sources with 24 μm detection strongly increases up to z ∼ 2 as a consequence of the rapid evolution that star-forming galaxies have undergone with look-back time. Nonetheless, this rising trend shows a clear break at z ∼ 1.3, probably due to k-correction effects implied by the complexity of spectral energy distributions in the mid-infrared. Finally, we compare our results with the predictions from different models of galaxy formation. We note that semianalytical formalisms currently fail to reproduce the redshift distributions observed at 24 μm. Furthermore, the simulated galaxies at S 24μm > 80 μJy exhibit R-K colors much bluer than observed and the predicted K-band fluxes are systematically underestimated at z ∼> 0.5. Unless these discrepancies mainly result from an incorrect treatment of extinction in the models they may reflect an underestimate of the predicted density of high-redshift massive sources with strong ongoing star formation, which would point to more fundamental processes and/or parameters (e.g., initial mass function, critical density to form stars, feedback,...) that are still not fully controlled in the simulations. The most recent backward evolution scenarios reproduce reasonably well the flux/redshift distribution of 24 μm sources up to z ∼ 3, although none of them is able to exactly match our results at all redshifts.

  3. Polycyclic Aromatic Hydrocarbon Emission in Spitzer /IRS Maps. II. A Direct Link between Band Profiles and the Radiation Field Strength

    Energy Technology Data Exchange (ETDEWEB)

    Stock, D. J.; Peeters, E., E-mail: dstock84@gmail.com [Department of Physics and Astronomy, University of Western Ontario, London, ON, N6A 3K7 (Canada)

    2017-03-10

    We decompose the observed 7.7 μ m polycyclic aromatic hydrocarbon (PAH) emission complexes in a large sample of over 7000 mid-infrared spectra of the interstellar medium using spectral cubes observed with the Spitzer /IRS-SL instrument. In order to fit the 7.7 μ m PAH emission complex we invoke four Gaussian components, which are found to be very stable in terms of their peak positions and widths across all of our spectra, and subsequently define a decomposition with fixed parameters, which gives an acceptable fit for all the spectra. We see a strong environmental dependence on the interrelationships between our band fluxes—in the H ii regions all four components are intercorrelated, while in the reflection nebulae (RNs) the inner and outer pairs of bands correlate in the same manner as previously seen for NGC 2023. We show that this effect arises because the maps of RNs are dominated by emission from strongly irradiated photodissociation regions, while the much larger maps of H ii regions are dominated by emission from regions much more distant from the exciting stars, leading to subtly different spectral behavior. Further investigation of this dichotomy reveals that the ratio of two of these components (centered at 7.6 and 7.8 μ m) is linearly related to the UV-field intensity (log G {sub 0}). We find that this relationship does not hold for sources consisting of circumstellar material, which are known to have variable 7.7 μ m spectral profiles.

  4. c2d Spitzer IRS spectra of embedded low-mass young stars : gas-phase emission lines

    NARCIS (Netherlands)

    Lahuis, F.; van Dishoeck, E. F.; Jorgensen, J. K.; Blake, G. A.; Evans, N. J.

    Context. A survey of mid-infrared gas-phase emission lines of H(2), H(2)O and various atoms toward a sample of 43 embedded low-mass young stars in nearby star-forming regions is presented. The sources are selected from the Spitzer "Cores to Disks" (c2d) legacy program. Aims. The environment of

  5. A SPITZER SURVEY OF PROTOPLANETARY DISK DUST IN THE YOUNG SERPENS CLOUD : HOW DO DUST CHARACTERISTICS EVOLVE WITH TIME?

    NARCIS (Netherlands)

    Oliveira, Isa; Pontoppidan, Klaus M.; Merin, Bruno; van Dishoeck, Ewine F.; Lahuis, Fred; Geers, Vincent C.; Jorgensen, Jes K.; Olofsson, Johan; Augereau, Jean-Charles; Brown, Joanna M.

    2010-01-01

    We present Spitzer InfraRed Spectrograph (IRS) mid-infrared (5-35 mu m) spectra of a complete flux-limited sample (>= 3 mJy at 8 mu m) of young stellar object (YSO) candidates selected on the basis of their infrared colors in the Serpens Molecular Cloud. Spectra of 147 sources are presented and

  6. ADAPTIVE LEARNING OF HIDDEN MARKOV MODELS FOR EMOTIONAL SPEECH

    Directory of Open Access Journals (Sweden)

    A. V. Tkachenia

    2014-01-01

    Full Text Available An on-line unsupervised algorithm for estimating the hidden Markov models (HMM parame-ters is presented. The problem of hidden Markov models adaptation to emotional speech is solved. To increase the reliability of estimated HMM parameters, a mechanism of forgetting and updating is proposed. A functional block diagram of the hidden Markov models adaptation algorithm is also provided with obtained results, which improve the efficiency of emotional speech recognition.

  7. Hidden superconformal symmetry: Where does it come from?

    Science.gov (United States)

    Inzunza, Luis; Plyushchay, Mikhail S.

    2018-02-01

    It is known that a single quantum harmonic oscillator is characterized by a hidden spectrum generating superconformal symmetry, but its origin has remained rather obscure. We show how this hidden superconformal symmetry can be derived by applying a nonlocal Foldy-Wouthuysen transformation to three extended systems with fermion degrees of freedom. The associated systems have essentially different nature from the point of view of conventional supersymmetric quantum mechanics, and generate the desired hidden symmetry in three different ways. We also trace out how the hidden superconformal symmetry of the quantum free particle system is produced in the limit of zero frequency.

  8. Discovery of hyperluminous infrared galaxies using Spitzer and SHARC-II

    Science.gov (United States)

    Borys, C.; Barnard, V.; Bian, C.; Blain, A. W.; Brown, M. J. I.; Dey, A.; Dowell, C. D.; Frayer, D. T.; Higdon, J.; Higdon, S.; Jannuzi, B.; Le Floch, E.; Soifer, B. T.; Phillips, T. G.

    2005-01-01

    We have used observations taken as part of the Bootes Spitzer GTO program to pre-select high redshift luminous star-forming galaxy candidates. Subsequent ground-based sub-millimeter imaging with SHARC-II at the Caltech Submillimeter Observatory detected several objects, including one particularly exotic one: An extremely bright infrared galaxy with an apparent luminosity in excess of 1013.5Lsolar. It has a spectral energy distribution similar to that of Arp 220, though appears to be at a much higher redshift. Although lensing is one possible explanation, this object has helped refine the selection method, and hints at a way to pre-select similar objects using mid-IR silicate absorption features.

  9. Observations of Hot-Jupiter occultations combining Spitzer and Kepler photometry

    Directory of Open Access Journals (Sweden)

    Knutson H.

    2011-02-01

    Full Text Available We present the status of an ongoing program which aim at measuring occultations by their parent stars of transiting hot giant exoplanets discovered recently by Kepler. The observations are obtained in the near infrared with WarmSpitzer Space Telescope and at optical wavelengths by combining more than a year of Kepler photometry. The investigation consists of measuring the mid-occultation times and the relative occultation depths in each band-passes. Our measurements of occultations depths in the Kepler bandpass is turned into the determination of the optical geometric albedo Ag in this wavelength domain. The brightness temperatures of these planets are deduced from the infrared observations. We combine the optical and near infrared planetary emergent fluxes to obtain broad band emergent spectra of individual planet. We finally compare these spectra to hot Jupiter atmospheric models in order broadly distinguishing these atmospheres between different classes of models.

  10. Spitzer/JWST Cross Calibration: IRAC Observations of Potential Calibrators for JWST

    Science.gov (United States)

    Carey, Sean J.; Gordon, Karl D.; Lowrance, Patrick; Ingalls, James G.; Glaccum, William J.; Grillmair, Carl J.; E Krick, Jessica; Laine, Seppo J.; Fazio, Giovanni G.; Hora, Joseph L.; Bohlin, Ralph

    2017-06-01

    We present observations at 3.6 and 4.5 microns using IRAC on the Spitzer Space Telescope of a set of main sequence A stars and white dwarfs that are potential calibrators across the JWST instrument suite. The stars range from brightnesses of 4.4 to 15 mag in K band. The calibration observations use a similar redundancy to the observing strategy for the IRAC primary calibrators (Reach et al. 2005) and the photometry is obtained using identical methods and instrumental photometric corrections as those applied to the IRAC primary calibrators (Carey et al. 2009). The resulting photometry is then compared to the predictions based on spectra from the CALSPEC Calibration Database (http://www.stsci.edu/hst/observatory/crds/calspec.html) and the IRAC bandpasses. These observations are part of an ongoing collaboration between IPAC and STScI investigating absolute calibration in the infrared.

  11. Spitzer spectral line mapping of the HH211 outflow

    DEFF Research Database (Denmark)

    Dionatos, Odyssefs; Nisini, Brunella; Cabrit, Sylvie

    2010-01-01

    of emission line diagnostics and an existing grid of molecular shock models. The physical properties of the warm gas are compared against other molecular jet tracers and to the results of a similar study towards the L1448-C outflow. Results: We have detected and mapped the v=0-0 S(0) - S(7) H2 lines and fine...... compared to solar abundances by a factor ~10-50. Conclusions: Spitzer spectral mapping observations reveal for the first time a cool H$_2$ component towards the CO jet of HH211 consistent with the CO material being fully molecular and warm at ~ 300 K. The maps also reveal for the first time the existence...... uncertainties on jet speed and shock conditions are too large for a definite conclusion....

  12. Model-independent indirect detection constraints on hidden sector dark matter

    Science.gov (United States)

    Elor, Gilly; Rodd, Nicholas L.; Slatyer, Tracy R.; Xue, Wei

    2016-06-01

    If dark matter inhabits an expanded ``hidden sector'', annihilations may proceed through sequential decays or multi-body final states. We map out the potential signals and current constraints on such a framework in indirect searches, using a model-independent setup based on multi-step hierarchical cascade decays. While remaining agnostic to the details of the hidden sector model, our framework captures the generic broadening of the spectrum of secondary particles (photons, neutrinos, e+e- and bar p p) relative to the case of direct annihilation to Standard Model particles. We explore how indirect constraints on dark matter annihilation limit the parameter space for such cascade/multi-particle decays. We investigate limits from the cosmic microwave background by Planck, the Fermi measurement of photons from the dwarf galaxies, and positron data from AMS-02. The presence of a hidden sector can change the constraints on the dark matter by up to an order of magnitude in either direction (although the effect can be much smaller). We find that generally the bound from the Fermi dwarfs is most constraining for annihilations to photon-rich final states, while AMS-02 is most constraining for electron and muon final states; however in certain instances the CMB bounds overtake both, due to their approximate independence on the details of the hidden sector cascade. We provide the full set of cascade spectra considered here as publicly available code with examples at http://web.mit.edu/lns/research/CascadeSpectra.html.

  13. Home-Explorer: Ontology-Based Physical Artifact Search and Hidden Object Detection System

    Directory of Open Access Journals (Sweden)

    Bin Guo

    2008-01-01

    Full Text Available A new system named Home-Explorer that searches and finds physical artifacts in a smart indoor environment is proposed. The view on which it is based is artifact-centered and uses sensors attached to the everyday artifacts (called smart objects in the real world. This paper makes two main contributions: First, it addresses, the robustness of the embedded sensors, which is seldom discussed in previous smart artifact research. Because sensors may sometimes be broken or fail to work under certain conditions, smart objects become hidden ones. However, current systems provide no mechanism to detect and manage objects when this problem occurs. Second, there is no common context infrastructure for building smart artifact systems, which makes it difficult for separately developed applications to interact with each other and uneasy for them to share and reuse knowledge. Unlike previous systems, Home-Explorer builds on an ontology-based knowledge infrastructure named Sixth-Sense, which makes it easy for the system to interact with other applications or agents also based on this ontology. The hidden object problem is also reflected in our ontology, which enables Home-Explorer to deal with both smart objects and hidden objects. A set of rules for deducing an object's status or location information and for locating hidden objects are described and evaluated.

  14. Hidden acoustic information revealed by intentional nonlinearity

    Science.gov (United States)

    Dowling, David R.

    2017-11-01

    Acoustic waves are omnipresent in modern life and are well described by the linearized equations of fluid dynamics. Once generated, acoustic waves carry and collect information about their source and the environment through which they propagate, respectively, and this information may be retrieved by analyzing recordings of these waves. Because of this, acoustics is the primary means for observation, surveillance, reconnaissance, and remote sensing in otherwise opaque environments, such as the Earth's oceans and crust, and the interior of the human body. For such information-retrieval tasks, acoustic fields are nearly always interrogated within their recorded frequency range or bandwidth. However, this frequency-range restriction is not general; acoustic fields may also carry (hidden) information at frequencies outside their bandwidth. Although such a claim may seem counter intuitive, hidden acoustic-field information can be revealed by re-introducing a marquee trait of fluid dynamics: nonlinearity. In particular, an intentional quadratic nonlinearity - a form of intra-signal heterodyning - can be used to obtain acoustic field information at frequencies outside a recorded acoustic field's bandwidth. This quadratic nonlinearity enables a variety of acoustic remote sensing applications that were long thought to be impossible. In particular, it allows the detrimental effects of sparse recordings and random scattering to be suppressed when the original acoustic field has sufficient bandwidth. In this presentation, the topic is developed heuristically, with a just brief exposition of the relevant mathematics. Hidden acoustic field information is then revealed from simulated and measured acoustic fields in simple and complicated acoustic environments involving frequencies from a few Hertz to more than 100 kHz, and propagation distances from tens of centimeters to hundreds of kilometers. Sponsored by ONR, NAVSEA, and NSF.

  15. A Spitzer five-band analysis of the Jupiter-sized planet TrES-1

    Energy Technology Data Exchange (ETDEWEB)

    Cubillos, Patricio; Harrington, Joseph; Foster, Andrew S. D.; Lust, Nate B.; Hardy, Ryan A.; Bowman, M. Oliver [Planetary Sciences Group, Department of Physics, University of Central Florida, Orlando, FL 32816-2385 (United States); Madhusudhan, Nikku, E-mail: pcubillos@fulbrightmail.org [Department of Physics and Department of Astronomy, Yale University, New Haven, CT 06511 (United States)

    2014-12-10

    With an equilibrium temperature of 1200 K, TrES-1 is one of the coolest hot Jupiters observed by Spitzer. It was also the first planet discovered by any transit survey and one of the first exoplanets from which thermal emission was directly observed. We analyzed all Spitzer eclipse and transit data for TrES-1 and obtained its eclipse depths and brightness temperatures in the 3.6 μm (0.083% ± 0.024%, 1270 ± 110 K), 4.5 μm (0.094% ± 0.024%, 1126 ± 90 K), 5.8 μm (0.162% ± 0.042%, 1205 ± 130 K), 8.0 μm (0.213% ± 0.042%, 1190 ± 130 K), and 16 μm (0.33% ± 0.12%, 1270 ± 310 K) bands. The eclipse depths can be explained, within 1σ errors, by a standard atmospheric model with solar abundance composition in chemical equilibrium, with or without a thermal inversion. The combined analysis of the transit, eclipse, and radial-velocity ephemerides gives an eccentricity of e=0.033{sub −0.031}{sup +0.015}, consistent with a circular orbit. Since TrES-1's eclipses have low signal-to-noise ratios, we implemented optimal photometry and differential-evolution Markov Chain Monte Carlo (MCMC) algorithms in our Photometry for Orbits, Eclipses, and Transits pipeline. Benefits include higher photometric precision and ∼10 times faster MCMC convergence, with better exploration of the phase space and no manual parameter tuning.

  16. Brown dwarf distances and atmospheres: Spitzer Parallaxes and the Keck/NIRSPEC upgrade

    Science.gov (United States)

    Martin, Emily C.

    2018-01-01

    Advances in infrared technology have been essential towards improving our understanding of the solar neighborhood, revealing a large population of brown dwarfs, which span the mass regime between planets and stars. My thesis combines near-infrared (NIR) spectroscopic and astrometric analysis of nearby low-mass stars and brown dwarfs with instrumentation work to upgrade the NIRSPEC instrument for the Keck II Telescope. I will present results from a program using Spitzer/IRAC data to measure precise locations and distances to 22 of the coldest and closest brown dwarfs. These distances allow us to constrain absolute physical properties, such as mass, radius, and age, of free-floating planetary-mass objects through comparison to atmospheric and evolutionary models. NIR spectroscopy combined with the Spitzer photometry reveals a detailed look into the atmospheres of brown dwarfs and gaseous extrasolar planets. Additionally, I will discuss the improvements we are making to the NIRSPEC instrument at Keck. NIRSPEC is a NIR echelle spectrograph, capable of R~2000 and R~25,000 observations in the 1-5 μm range. As part of the upgrade, I performed detector characterization, optical design of a new slit-viewing camera, mechanical testing, and electronics design. NIRSPEC’s increased efficiency will allow us to obtain moderate- and high-resolution NIR spectra of objects up to a magnitude fainter than the current NIRSPEC design. Finally, I will demonstrate the utility of a NIR laser frequency comb as a high-resolution calibrator. This new technology will revolutionize precision radial velocity measurements in the coming decade.

  17. Spitzer and Chandra Observations of the Deep Impact Encounter with Comet 9P/Tempel 1

    Science.gov (United States)

    Lisse, C. M.; A'Hearn, M. F.; Belton, M. J. S.; Bodewits, D.; Christian, D. J.; VanCleve, J.; Combi, M.; Dennerl, K.; Farnham, T. L.; Fernandez, Y. R.; Groussin, O.; Hoekstra, R.; Makinen, T.; McFadden, L. A.; Meech, K. J.; Schultz, P.; Weaver, H.; Wolk, S.

    2005-12-01

    On July 4, 2005 NASA's discovery mission Deep Impact (hereafter DI) sent a 375 kg impactor into the nucleus of comet 9P/Tempel 1 at 10.2 km/s relative velocity (A'Hearn et al. 2005). In the IR, Spitzer observed the comet in the unique 5-38 μm spectral range provided by the IRS instrument, allowing direct determination of silicaceous dust, PAHs, carbonates, and aluminum and iron oxides/sulfides in the subsurface material. The Spitzer observations contrasted well with the 1-5 μm spectra obtained by the DI High Resolution Instrument's IR spectrometer and ground based measurements at 1-5 um from the Keck and IRTF observatories (Meech et al. 2005), enabling us to obtain full coverage of the comet's IR spectrum from 1.0 to 38 μm. In the x-ray, the DI experiment allowed for a controlled test of the charge exchange (CXE) emission mechanism that drives cometary x-ray emission (Lisse et al. 2001, Kharchenko and Dalgarno 2001, Krasnopolsky et al. 2002) using observations with the Chandra ACIS-S CCD. The Chandra spectra show a fresh amount of neutral material was injected into a finite volume of the extended atmosphere, or coma, of the comet. In the matter of minutes, this new material directly increased the emission measure for the comet by 30 production from other measurements. Additional contemporaneous measurements by the XMM and SWIFT low energy x-ray imagers provided complimentary lightcurve data points, providing a good long term estimate of the comet's gas emission before, during, and after the Deep Impact encounter. Over the longer term, the combined lightcurves showed evidence of multiple natural outbursts of neutral gas emission from the comet.

  18. THE SPITZER INFRARED SPECTROGRAPH DEBRIS DISK CATALOG. I. CONTINUUM ANALYSIS OF UNRESOLVED TARGETS

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Christine H. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Mittal, Tushar [Department of Earth and Planetary Science, University of California Berkeley, Berkeley, CA 94720-4767 (United States); Kuchner, Marc [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States); Forrest, William J.; Watson, Dan M. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Lisse, Carey M. [Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Manoj, P. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005 (India); Sargent, Benjamin A., E-mail: cchen@stsci.edu [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States)

    2014-04-01

    During the Spitzer Space Telescope cryogenic mission, Guaranteed Time Observers, Legacy Teams, and General Observers obtained Infrared Spectrograph (IRS) observations of hundreds of debris disk candidates. We calibrated the spectra of 571 candidates, including 64 new IRAS and Multiband Imaging Photometer for Spitzer (MIPS) debris disks candidates, modeled their stellar photospheres, and produced a catalog of excess spectra for unresolved debris disks. For 499 targets with IRS excess but without strong spectral features (and a subset of 420 targets with additional MIPS 70 μm observations), we modeled the IRS (and MIPS data) assuming that the dust thermal emission was well-described using either a one- or two-temperature blackbody model. We calculated the probability for each model and computed the average probability to select among models. We found that the spectral energy distributions for the majority of objects (∼66%) were better described using a two-temperature model with warm (T {sub gr} ∼ 100-500 K) and cold (T {sub gr} ∼ 50-150 K) dust populations analogous to zodiacal and Kuiper Belt dust, suggesting that planetary systems are common in debris disks and zodiacal dust is common around host stars with ages up to ∼1 Gyr. We found that younger stars generally have disks with larger fractional infrared luminosities and higher grain temperatures and that higher-mass stars have disks with higher grain temperatures. We show that the increasing distance of dust around debris disks is inconsistent with self-stirred disk models, expected if these systems possess planets at 30-150 AU. Finally, we illustrate how observations of debris disks may be used to constrain the radial dependence of material in the minimum mass solar nebula.

  19. A deep Spitzer survey of circumstellar disks in the young double cluster, h and χ Persei

    Energy Technology Data Exchange (ETDEWEB)

    Cloutier, Ryan; Currie, Thayne; Jayawardhana, Ray [University of Toronto, 50 St. George Street, Toronto, ON, M5S 2J7 (Canada); Rieke, George H. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065 (United States); Kenyon, Scott J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02140 (United States); Balog, Zoltan, E-mail: cloutier@cita.utoronto.ca, E-mail: currie@astro.utoronto.ca, E-mail: grieke@as.arizona.edu, E-mail: skenyon@cfa.harvard.edu [Max Planck Institute for Astrophysics, Königstuhl 17, D-69117 Heidelberg (Germany)

    2014-12-01

    We analyze very deep Infrared Array Camera and Multiband Imaging Photometer for Spitzer (MIPS) photometry of ∼12, 500 members of the 14 Myr old Double Cluster, h and χ Persei, building upon our earlier, shallower Spitzer Cycle 1 studies. Numerous likely members show infrared (IR) excesses at 8 μm and 24 μm, indicative of circumstellar dust. The frequency of stars with 8 μm excess is at least 2% for our entire sample, slightly lower (higher) for B/A stars (later type, lower mass stars). Optical spectroscopy also identifies gas in about 2% of systems, but with no clear trend between the presence of dust and gas. Spectral energy distribution modeling of 18 sources with detections at optical wavelengths through MIPS 24 μm reveals a diverse set of disk evolutionary states, including a high fraction of transitional disks, though similar data for all disk-bearing members would provide constraints. Using Monte Carlo simulations, we combine our results with those for other young clusters to study the global evolution of dust/gas disks. For nominal cluster ages, the e-folding times (τ{sub 0}) for the frequency of warm dust and gas are 2.75 Myr and 1.75 Myr, respectively. Assuming a revised set of ages for some clusters, these timescales increase to 5.75 and 3.75 Myr, respectively, implying a significantly longer typical protoplanetary disk lifetime than previously thought. In both cases, the transitional disk duration, averaged over multiple evolutionary pathways, is ≈1 Myr. Finally, 24 μm excess frequencies for 4-6 M {sub ☉} stars appear lower than for 1-2.5 M {sub ☉} stars in other 10-30 Myr old clusters.

  20. Some Cosmological Implications of Hidden Sectors

    CERN Document Server

    Espinosa, J R; No, J M; Quirós, Mariano

    2008-01-01

    We discuss some cosmological implications of extensions of the Standard Model with hidden sector scalars coupled to the Higgs boson. We put special emphasis on the conformal case, in which the electroweak symmetry is broken radiatively with a Higgs mass above the experimental limit. Our refined analysis of the electroweak phase transition in this kind of models strengthens the prediction of a strongly first-order phase transition as required by electroweak baryogenesis. We further study gravitational wave production and the possibility of low-scale inflation as well as a viable dark matter candidate.

  1. Die Beharrlichkeit im Verborgenen Hidden Persistence

    Directory of Open Access Journals (Sweden)

    Paula-Irene Villa

    2003-07-01

    Full Text Available Karin Flaake geht in ihrer psychoanalytischen Interpretation innerfamilialer Konstellationen der Frage nach, wie das Zur-Frau-Werden von jungen Frauen erlebt wird. Dabei kommt den körperliche Wandlungsprozessen der Pubertät und den darin eingelagerten expliziten sowie verborgenen Deutungen des Weiblichen – vor allem des weiblichen Körpers – durch die Eltern eine prominente Rolle zu.Karin Flaake’s psychoanalytical intepretations of family constellations explore how young women experience their coming of age and entering womanhood. Her analysis focuses on the bodily changes which women undergo during puberty and the explicit as well as hidden meanings assigned to them by the parents.

  2. Detecting Structural Breaks using Hidden Markov Models

    DEFF Research Database (Denmark)

    Ntantamis, Christos

    Testing for structural breaks and identifying their location is essential for econometric modeling. In this paper, a Hidden Markov Model (HMM) approach is used in order to perform these tasks. Breaks are defined as the data points where the underlying Markov Chain switches from one state to another....... The estimation of the HMM is conducted using a variant of the Iterative Conditional Expectation-Generalized Mixture (ICE-GEMI) algorithm proposed by Delignon et al. (1997), that permits analysis of the conditional distributions of economic data and allows for different functional forms across regimes...

  3. Hidden Scale Invariance in Condensed Matter

    DEFF Research Database (Denmark)

    Dyre, J. C.

    2014-01-01

    . This means that the phase diagram becomes effectively one-dimensional with regard to several physical properties. Liquids and solids with isomorphs include most or all van der Waals bonded systems and metals, as well as weakly ionic or dipolar systems. On the other hand, systems with directional bonding...... (hydrogen bonds or covalent bonds) or strong Coulomb forces generally do not exhibit hidden scale invariance. The article reviews the theory behind this picture of condensed matter and the evidence for it coming from computer simulations and experiments...

  4. The hidden face of the petroleum

    International Nuclear Information System (INIS)

    Laurent, E.

    2006-02-01

    For the first time, a book reveals what that was hidden to the public opinions: why the petroleum crisis of 1973 what only a manipulation, an arrangement between the OPEC and the petroleum companies, why the data concerning the petroleum reserves are wrong and increased by the producers countries, how Washington used the Saudi petroleum weapon to create the Soviet Union fall, and why from march 2001 maps of the Iraq (where were drawn the future petroleum explorations) were working documents for the vice President Cheney and petroleum managers for the ''secret society''. (A.L.B.)

  5. Hidden Anemias in the Critically Ill.

    Science.gov (United States)

    O'Malley, Patricia

    2017-09-01

    With increasing knowledge of the risks associated with receiving blood transfusions, a new paradigm of bloodless medicine is needed. Principles of bloodless medicine include careful monitoring for obvious and hidden anemias, rapid intervention, minimizing blood losses from laboratory testing and procedures, and careful management of bleeding diatheses. As evidence is revealed and refined, standard treatment of anemia in the intensive care unit will include erythropoietin-stimulating agents, iron, folate, and vitamin B12, which will reduce risks associated with blood transfusions. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Maurice Halbwachs: Official and hidden memory

    Directory of Open Access Journals (Sweden)

    Carretero, Angel

    2008-05-01

    Full Text Available This article tries to show, in general terms, how Maurice Halbwachs has discovered presence and vitality in the collective memorieswhich have been excluded from the socially-institutionalized world. In order to decipher his opaque writing, one should try for a sociology of the depths, for a sociological look that, separating itself from the dominant positivism of the social sciences, manages to penetrate the hidden logic that permanently underlies social life. This article seeks to uncover the nature of a collective memory that respects the vicissitudes of time, as well as its difficult relations both with official memory and with the dominant historical record.

  7. Error statistics of hidden Markov model and hidden Boltzmann model results

    Directory of Open Access Journals (Sweden)

    Newberg Lee A

    2009-07-01

    Full Text Available Abstract Background Hidden Markov models and hidden Boltzmann models are employed in computational biology and a variety of other scientific fields for a variety of analyses of sequential data. Whether the associated algorithms are used to compute an actual probability or, more generally, an odds ratio or some other score, a frequent requirement is that the error statistics of a given score be known. What is the chance that random data would achieve that score or better? What is the chance that a real signal would achieve a given score threshold? Results Here we present a novel general approach to estimating these false positive and true positive rates that is significantly more efficient than are existing general approaches. We validate the technique via an implementation within the HMMER 3.0 package, which scans DNA or protein sequence databases for patterns of interest, using a profile-HMM. Conclusion The new approach is faster than general naïve sampling approaches, and more general than other current approaches. It provides an efficient mechanism by which to estimate error statistics for hidden Markov model and hidden Boltzmann model results.

  8. Hidden Treasure: Successful International Doctoral Students Who Found and Harnessed the Hidden Curriculum

    Science.gov (United States)

    Elliot, Dely Lazarte; Baumfield, Vivienne; Reid, Kate; Makara, Kara A.

    2016-01-01

    This paper draws from an institutionally-funded phenomenological study of international PhD students' academic acculturation, which focuses on the distinctive strengths, challenges, and hidden opportunities facing this cohort within the context of their transition from one academic culture to another. The first section introduces the theoretical…

  9. Global Update and Trends of Hidden Hunger, 1995-2011: The Hidden Hunger Index.

    Directory of Open Access Journals (Sweden)

    Julie C Ruel-Bergeron

    Full Text Available Deficiencies in essential vitamins and minerals-also termed hidden hunger-are pervasive and hold negative consequences for the cognitive and physical development of children.This analysis evaluates the change in hidden hunger over time in the form of one composite indicator-the Hidden Hunger Index (HHI-using an unweighted average of prevalence estimates from the Nutrition Impact Model Study for anemia due to iron deficiency, vitamin A deficiency, and stunting (used as a proxy indicator for zinc deficiency. Net changes from 1995-2011 and population weighted regional means for various time periods are measured.Globally, hidden hunger improved (-6.7 net change in HHI from 1995-2011. Africa was the only region to see a deterioration in hidden hunger (+1.9 over the studied time period; East Asia and the Pacific performed exceptionally well (-13.0, while other regions improved only slightly. Improvements in HHI were mostly due to reductions in zinc and vitamin A deficiencies, while anemia due to iron deficiency persisted and even increased.This analysis is critical for informing and tracking the impact of policy and programmatic efforts to reduce micronutrient deficiencies, to advance the global nutrition agenda, and to achieve the Millennium Development Goals (MDGs. However, there remains an unmet need to invest in gathering frequent, nationally representative, high-quality micronutrient data as we renew our efforts to scale up nutrition, and as we enter the post-2015 development agenda.Preparation of this manuscript was funded by Sight and Life. There was no funding involved in the study design, data collection, analysis, or decision to publish.

  10. Laser experiments explore the hidden sector

    Energy Technology Data Exchange (ETDEWEB)

    Ahlers, M. [Oxford Univ. (United Kingdom). Rudolf Peierls Centre for Theoretical Physics; Gies, H. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik; Jaeckel, J. [Heidelberg Univ. (Germany). Inst. fuer Theoretische Physik]|[Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Redondo, J.; Ringwald, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2007-11-15

    Recently, the laser experiments BMV and GammeV, searching for light shining through walls, have published data and calculated new limits on the allowed masses and couplings for axion-like particles. In this note we point out that these experiments can serve to constrain a much wider variety of hidden-sector particles such as, e.g., minicharged particles and hidden-sector photons. The new experiments improve the existing bounds from the older BFRT experiment by a factor of two. Moreover, we use the new PVLAS constraints on a possible rotation and ellipticity of light after it has passed through a strong magnetic field to constrain pure minicharged particle models. For masses

  11. Black holes, hidden symmetries, and complete integrability.

    Science.gov (United States)

    Frolov, Valeri P; Krtouš, Pavel; Kubizňák, David

    2017-01-01

    The study of higher-dimensional black holes is a subject which has recently attracted vast interest. Perhaps one of the most surprising discoveries is a realization that the properties of higher-dimensional black holes with the spherical horizon topology and described by the Kerr-NUT-(A)dS metrics are very similar to the properties of the well known four-dimensional Kerr metric. This remarkable result stems from the existence of a single object called the principal tensor. In our review we discuss explicit and hidden symmetries of higher-dimensional Kerr-NUT-(A)dS black hole spacetimes. We start with discussion of the Killing and Killing-Yano objects representing explicit and hidden symmetries. We demonstrate that the principal tensor can be used as a "seed object" which generates all these symmetries. It determines the form of the geometry, as well as guarantees its remarkable properties, such as special algebraic type of the spacetime, complete integrability of geodesic motion, and separability of the Hamilton-Jacobi, Klein-Gordon, and Dirac equations. The review also contains a discussion of different applications of the developed formalism and its possible generalizations.

  12. Hidden ion population of the magnetosphere

    International Nuclear Information System (INIS)

    Olsen, R.C.

    1982-01-01

    Particle data from two geosynchronous satellites (Applied Technology Satellite 6 and SCATHA) show a normally hidden ion population appearing when the satellites are in the earth's shadow. Ion and electron data show the spacecraft potential dropping from +10 V in sunlight to +4 and +5 V in eclipse at local midnight, in low-energy (T/sub e/ -2 ), isotropic ion population appears which was invisible in sunlight because of the larger positive spacecraft potential. Higher-energy populations generally cover the tails of the hidden ion populations, so they cannot be inferred from daylight data. The isotropic populations appears only in a few percent of the spacecraft eclipse events, appearing only at times of low Kp (2 or less, preceded by a day with Σ Kp< or =20). A low-energy (T = 1--2 eV) field-aligned population often appears with and without the isotropic population, at slightly higher flux levels. These fluxes are visible in sunlight, but again the distribution functions obtained in eclipse differ from those that would be inferred from daylight data. Measurement of the thermal plasma population on a consistent basis, particularly in the plasma sheet, will require some method of controlling the detector potential with respect to the ambient plamsa

  13. Flavor-singlet hidden charm pentaquark

    Science.gov (United States)

    Irie, Yoya; Oka, Makoto; Yasui, Shigehiro

    2018-02-01

    One type of hidden charm pentaquark Pc s with quark content c c ¯u d s in light-flavor singlet state is studied in the quark model. This state is analogous to the Pc with c c ¯u u d in light-flavor octet, which was observed in LHC in 2015. Considering various combinations of color, spin, and light flavor as internal quantum numbers in Pc s, we investigate the mass ordering of the Pc s's by adopting both the one-gluon exchange interaction and the instanton-induced interaction in the quark model. The most stable configuration of Pc s is identified to be total spin 1 /2 in which the c c ¯ is combined to be color octet and spin 1, while the u d s cluster is in a color octet state. The other color octet configurations, the total spin 1 /2 state with the c c ¯ spin 0, and the state with total spin 3 /2 and c c ¯ spin 1, are found as excited states. We also discuss possible decay modes of these hidden charm pentaquarks.

  14. Monitoring volcano activity through Hidden Markov Model

    Science.gov (United States)

    Cassisi, C.; Montalto, P.; Prestifilippo, M.; Aliotta, M.; Cannata, A.; Patanè, D.

    2013-12-01

    During 2011-2013, Mt. Etna was mainly characterized by cyclic occurrences of lava fountains, totaling to 38 episodes. During this time interval Etna volcano's states (QUIET, PRE-FOUNTAIN, FOUNTAIN, POST-FOUNTAIN), whose automatic recognition is very useful for monitoring purposes, turned out to be strongly related to the trend of RMS (Root Mean Square) of the seismic signal recorded by stations close to the summit area. Since RMS time series behavior is considered to be stochastic, we can try to model the system generating its values, assuming to be a Markov process, by using Hidden Markov models (HMMs). HMMs are a powerful tool in modeling any time-varying series. HMMs analysis seeks to recover the sequence of hidden states from the observed emissions. In our framework, observed emissions are characters generated by the SAX (Symbolic Aggregate approXimation) technique, which maps RMS time series values with discrete literal emissions. The experiments show how it is possible to guess volcano states by means of HMMs and SAX.

  15. Epitope discovery with phylogenetic hidden Markov models.

    LENUS (Irish Health Repository)

    Lacerda, Miguel

    2010-05-01

    Existing methods for the prediction of immunologically active T-cell epitopes are based on the amino acid sequence or structure of pathogen proteins. Additional information regarding the locations of epitopes may be acquired by considering the evolution of viruses in hosts with different immune backgrounds. In particular, immune-dependent evolutionary patterns at sites within or near T-cell epitopes can be used to enhance epitope identification. We have developed a mutation-selection model of T-cell epitope evolution that allows the human leukocyte antigen (HLA) genotype of the host to influence the evolutionary process. This is one of the first examples of the incorporation of environmental parameters into a phylogenetic model and has many other potential applications where the selection pressures exerted on an organism can be related directly to environmental factors. We combine this novel evolutionary model with a hidden Markov model to identify contiguous amino acid positions that appear to evolve under immune pressure in the presence of specific host immune alleles and that therefore represent potential epitopes. This phylogenetic hidden Markov model provides a rigorous probabilistic framework that can be combined with sequence or structural information to improve epitope prediction. As a demonstration, we apply the model to a data set of HIV-1 protein-coding sequences and host HLA genotypes.

  16. SPITZER SECONDARY ECLIPSE DEPTHS WITH MULTIPLE INTRAPIXEL SENSITIVITY CORRECTION METHODS OBSERVATIONS OF WASP-13b, WASP-15b, WASP-16b, WASP-62b, AND HAT-P-22b

    Energy Technology Data Exchange (ETDEWEB)

    Kilpatrick, Brian M.; Tucker, Gregory S. [Department of Physics, Box 1843, Brown University, Providence, RI 02904 (United States); Lewis, Nikole K. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Kataria, Tiffany [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Deming, Drake [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Ingalls, James G.; Krick, Jessica E., E-mail: brian_kilpatrick@brown.edu, E-mail: nlewis@stsci.org, E-mail: tiffany.kataria@jpl.nasa.gov, E-mail: ddeming@astro.umd.edu, E-mail: krick@ipac.caltech.edu [Spitzer Science Center, Infrared Processing and Analysis Center, California Institute of Technology, Mail Code 220-6, Pasadena, CA 91125 (United States)

    2017-01-01

    We measure the 4.5 μ m thermal emission of five transiting hot Jupiters, WASP-13b, WASP-15b, WASP-16b, WASP-62b, and HAT-P-22b using channel 2 of the Infrared Array Camera (IRAC) on the Spitzer Space Telescope . Significant intrapixel sensitivity variations in Spitzer IRAC data require careful correction in order to achieve precision on the order of several hundred parts per million (ppm) for the measurement of exoplanet secondary eclipses. We determine eclipse depths by first correcting the raw data using three independent data reduction methods. The Pixel Gain Map (PMAP), Nearest Neighbors (NNBR), and Pixel Level Decorrelation (PLD) each correct for the intrapixel sensitivity effect in Spitzer photometric time-series observations. The results from each methodology are compared against each other to establish if they reach a statistically equivalent result in every case and to evaluate their ability to minimize uncertainty in the measurement. We find that all three methods produce reliable results. For every planet examined here NNBR and PLD produce results that are in statistical agreement. However, the PMAP method appears to produce results in slight disagreement in cases where the stellar centroid is not kept consistently on the most well characterized area of the detector. We evaluate the ability of each method to reduce the scatter in the residuals as well as in the correlated noise in the corrected data. The NNBR and PLD methods consistently minimize both white and red noise levels and should be considered reliable and consistent. The planets in this study span equilibrium temperatures from 1100 to 2000 K and have brightness temperatures that require either high albedo or efficient recirculation. However, it is possible that other processes such as clouds or disequilibrium chemistry may also be responsible for producing these brightness temperatures.

  17. Resting state brain networks from EEG: Hidden Markov states vs. classical microstates

    OpenAIRE

    Rukat, Tammo; Baker, Adam; Quinn, Andrew; Woolrich, Mark

    2016-01-01

    Functional brain networks exhibit dynamics on the sub-second temporal scale and are often assumed to embody the physiological substrate of cognitive processes. Here we analyse the temporal and spatial dynamics of these states, as measured by EEG, with a hidden Markov model and compare this approach to classical EEG microstate analysis. We find dominating state lifetimes of 100--150\\,ms for both approaches. The state topographies show obvious similarities. However, they also feature distinct s...

  18. Does violence affect the use of contraception? Identifying the hidden factors from rural India

    OpenAIRE

    Nishikant Singh; Sudheer Kumar Shukla

    2017-01-01

    Purpose: The objective of this study is to investigates the relationship between domestic violence and use of contraception among married women in rural India. Data: Third round of National Family Health Survey (NFHS-III). Methodology: Cross tabulation as bivariate analysis and Binary Logistic Regression as multivariate analysis has been employed to fulfill the objective. Findings: The result shows that there are several hidden factors. between physical violence and contraception use. Alterna...

  19. The Influence of Entrepreneurship Subject on Students’ Interest in Entrepreneurship by Hidden Curriculum as Intervening Variable

    OpenAIRE

    Amin Kuncoro; Hutomo Rusdianto

    2016-01-01

    This research aims to know the influence of entrepreneurship subject on students’ interest in entrepreneurship at Institute of Mathaliul Falah (IPMAFA) in Pati by hidden curriculum as intervening variable. The research used WarpsPls analysis to test model directly and directly. Samples of the study were 30 Islamic banking students who got entrepreneurship subject and Islamic community development who did not get the entrepreneurship subject. Findings show that the entrepreneurship subject inf...

  20. Risk from the frontlines of a hidden epidemic sexuality, masculinities ...

    African Journals Online (AJOL)

    Risk from the frontlines of a hidden epidemic sexuality, masculinities and social pressures among men who have sex with men in South Africa: an overview. ... These factors are discussed in this paper with stress put particularly on the hiddenness of the MSM HIV epidemic, and it is concluded that the complex mix of factors ...

  1. Quantum algorithm for identifying hidden polynomial function graphs

    NARCIS (Netherlands)

    T. Decker; J. Draisma (Jan); P. Wocjan

    2008-01-01

    htmlabstractWe consider a natural generalization of an abelian Hidden Subgroup Problem where the subgroups and their cosets correspond to graphs of linear functions over a finite field F with d elements. The hidden functions of the generalized problem are not restricted to be linear but can also be

  2. Quantum algorithm for identifying hidden polynomial function graphs

    NARCIS (Netherlands)

    T. Decker; J. Draisma (Jan); P. Wocjan

    2009-01-01

    htmlabstractWe consider a natural generalization of an abelian Hidden Subgroup Problem where the subgroups and their cosets correspond to graphs of linear functions over a finite field F with d elements. The hidden functions of the generalized problem are not restricted to be linear but can also be

  3. Secret Codes: The Hidden Curriculum of Semantic Web Technologies

    Science.gov (United States)

    Edwards, Richard; Carmichael, Patrick

    2012-01-01

    There is a long tradition in education of examination of the hidden curriculum, those elements which are implicit or tacit to the formal goals of education. This article draws upon that tradition to open up for investigation the hidden curriculum and assumptions about students and knowledge that are embedded in the coding undertaken to facilitate…

  4. Asymptotics for Estimating Equations in Hidden Markov Models

    DEFF Research Database (Denmark)

    Hansen, Jørgen Vinsløv; Jensen, Jens Ledet

    Results on asymptotic normality for the maximum likelihood estimate in hidden Markov models are extended in two directions. The stationarity assumption is relaxed, which allows for a covariate process influencing the hidden Markov process. Furthermore a class of estimating equations is considered...

  5. Optimisation of Hidden Markov Model using Baum–Welch algorithm ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 126; Issue 1. Optimisation of Hidden Markov ... The present work is a part of development of Hidden Markov Model (HMM) based avalanche forecasting system for Pir-Panjal and Great Himalayan mountain ranges of the Himalaya. In this work, HMMs have been ...

  6. Searching for hidden sector in multiparticle production at LHC

    Directory of Open Access Journals (Sweden)

    Miguel-Angel Sanchis-Lozano

    2016-03-01

    Full Text Available We study the impact of a hidden sector beyond the Standard Model, e.g. a Hidden Valley model, on factorial moments and cumulants of multiplicity distributions in multiparticle production with a special emphasis on the prospects for LHC results.

  7. How Classical Conditioning Shapes Placebo Analgesia: Hidden versus Open Conditioning.

    Science.gov (United States)

    Babel, Przemyslaw; Adamczyk, Waclaw; Swider, Karolina; Bajcar, Elzbieta A; Kicman, Pawel; Lisinska, Natalia

    2017-07-22

    To investigate the influence of expectancy of pain intensity, fear of pain (trait), and fear (state) on the effectiveness of hidden and open conditioning to produce placebo analgesia. A total of 90 healthy female volunteers were randomly assigned to three groups (hidden conditioning, open conditioning, and control) that received electrical stimuli preceded by either orange or blue lights. One color was paired with painful stimuli (control stimuli) and the other color was paired with nonpainful stimuli (conditioned stimuli) in both the hidden and open conditioning groups. Only participants in the open conditioning group were informed about this association. In the control group, both color lights were followed by control stimuli. In the testing phase, both colored lights were followed by identical control stimuli. Participants rated pain intensity, expectancy of pain intensity, fear, and fear of pain. A significant analgesic effect was found only in the hidden conditioning group, where no explicit verbal suggestions were provided. Hidden conditioning had an effect on expectancy and fear-participants in the hidden conditioning group expected less pain and experienced less fear in relation to conditioned stimuli. Fear was the only predictor of placebo analgesia in the hidden conditioning group. Neither expectancy of pain intensity nor fear of pain predicted placebo analgesia. Fear seems to be a more important factor than expectancy in producing placebo analgesia induced by hidden conditioning. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

  8. Hidden Curriculum as One of Current Issue of Curriculum

    Science.gov (United States)

    Alsubaie, Merfat Ayesh

    2015-01-01

    There are several issues in the education system, especially in the curriculum field that affect education. Hidden curriculum is one of current controversial curriculum issues. Many hidden curricular issues are the result of assumptions and expectations that are not formally communicated, established, or conveyed within the learning environment.…

  9. A Multiple Hidden Layers Extreme Learning Machine Method and Its Application

    OpenAIRE

    Xiao, Dong; Li, Beijing; Mao, Yachun

    2017-01-01

    Extreme learning machine (ELM) is a rapid learning algorithm of the single-hidden-layer feedforward neural network, which randomly initializes the weights between the input layer and the hidden layer and the bias of hidden layer neurons and finally uses the least-squares method to calculate the weights between the hidden layer and the output layer. This paper proposes a multiple hidden layers ELM (MELM for short) which inherits the characteristics of parameters of the first hidden layer. The ...

  10. Abelian Hidden Sectors at a GeV

    Energy Technology Data Exchange (ETDEWEB)

    Morrissey, David E.; Poland, David; /Harvard U.; Zurek, Kathryn; /Fermilab /Michigan U.

    2009-04-16

    We discuss mechanisms for naturally generating GeV-scale hidden sectors in the context of weak-scale supersymmetry. Such low mass scales can arise when hidden sectors are more weakly coupled to supersymmetry breaking than the visible sector, as happens when supersymmetry breaking is communicated to the visible sector by gauge interactions under which the hidden sector is uncharged, or if the hidden sector is sequestered from gravity-mediated supersymmetry breaking. We study these mechanisms in detail in the context of gauge and gaugino mediation, and present specific models of Abelian GeV-scale hidden sectors. In particular, we discuss kinetic mixing of a U(1){sub x} gauge force with hypercharge, singlets or bi-fundamentals which couple to both sectors, and additional loop effects. Finally, we investigate the possible relevance of such sectors for dark matter phenomenology, as well as for low- and high-energy collider searches.

  11. Mechanism of Pseudogap Detected by Electronic Raman Scattering: Phase Fluctuation or Hidden Order?

    International Nuclear Information System (INIS)

    Hong-Yan, Lu; Yuan, Wan; Xiang-Mei, He; Qiang-Hua, Wang

    2009-01-01

    We study the electronic Raman scattering in the cuprates to distinguish the two possible scenarios of the pseudo-gap normal state. In one scenario, the pseudogap is assumed to be caused by phase fluctuations of the preformed Cooper pairs. We find that pair-breaking peaks appear in both the B 1g and B 2g Raman channels, and they are smeared and tend to shift to the same energy with the increasing strength of phase fluctuations. Thus both channels reflect the same pairing energy scale, irrespectively of the doping level. In another scenario, the pseudogap is assumed to be caused by a hidden order that competes with the superconducting order. As an example, we assume that the hidden order is the d-density-wave (DDW) order. We find analytically and numerically that in the DDW normal state there is no Raman peak in the B 2g channel in a tight-binding model up to the second nearest-neighbor hopping, while the Raman peak in the B 1g channel reflects the energy gap caused by the DDW order. This behavior is in agreement with experiments in the pseudogap normal state. To gain further insights, we also calculate the Raman spectra in the DDW+SC state. We study the doping and temperature dependence of the peak energy in both channels and find a two-gap behavior, which is in agreement with recent Raman experiments. Therefore, our results shed light on the hidden order scenario for the pseudogap

  12. Identifying hidden sexual bridging communities in Chicago.

    Science.gov (United States)

    Youm, Yoosik; Mackesy-Amiti, Mary Ellen; Williams, Chyvette T; Ouellet, Lawrence J

    2009-07-01

    Bridge populations can play a central role in the spread of human immunodeficiency virus (HIV) by providing transmission links between higher and lower prevalence populations. While social network methods are well suited to the study of bridge populations, analyses tend to focus on dyads (i.e., risk between drug and/or sex partners) and ignore bridges between distinct subpopulations. This study takes initial steps toward moving the analysis of sexual network linkages beyond individual and risk group levels to a community level in which Chicago's 77 community areas are examined as subpopulations for the purpose of identifying potential bridging communities. Of particular interest are "hidden" bridging communities; that is, areas with above-average levels of sexual ties with other areas but whose below-average AIDS prevalence may hide their potential importance for HIV prevention. Data for this analysis came from the first wave of recruiting at the Chicago Sexual Acquisition and Transmission of HIV Cooperative Agreement Program site. Between August 2005 through October 2006, respondent-driven sampling was used to recruit users of heroin, cocaine, or methamphetamine, men who have sex with men regardless of drug use, the sex partners of these two groups, and sex partners of the sex partners. In this cross-sectional study of the sexual transmission of HIV, participants completed a network-focused computer-assisted self-administered interview, which included questions about the geographic locations of sexual contacts with up to six recent partners. Bridging scores for each area were determined using a matrix representing Chicago's 77 community areas and were assessed using two measures: non-redundant ties and flow betweenness. Bridging measures and acquired immunodeficiency syndrome (AIDS) case prevalence rates were plotted for each community area on charts representing four conditions: below-average bridging and AIDS prevalence, below-average bridging and above

  13. … To be hidden does not mean to be merely revealed – Part 1 Artistic research on hidden curriculum

    Directory of Open Access Journals (Sweden)

    Annette Krause

    2015-09-01

    Full Text Available This text revisits the long-term project Hidden Curriculum, initiated by Annette Krauss. The project addresses unquestioned routines, hierarchies of knowledge (part 1, and the role of the body in learning processes (part 2 from the perspective of secondary/high school education (in the research on a hidden curriculum. A deeper analysis of educational studies on the phenomenon of ‘hidden curriculum’ in relation to the feminist and critical pedagogies of bell hooks, Paulo Freire, and Jacques Rancière brings forward important insights generated through the artistic research within hidden curriculum. The aim of this text is to address academic canons, corporeality, and investigate everyday norms through revisiting the framework, results, and processes of the collaborative research into hidden curriculum with secondary high school students.

  14. IPHAS A-TYPE STARS WITH MID-INFRARED EXCESSES IN SPITZER SURVEYS

    International Nuclear Information System (INIS)

    Hales, Antonio S.; Barlow, Michael J.; Drew, Janet E.; Unruh, Yvonne C.; Greimel, Robert; Irwin, Michael J.; Gonzalez-Solares, Eduardo

    2009-01-01

    We have identified 17 A-type stars in the Galactic Plane that have mid-infrared (mid-IR) excesses at 8 μm. From observed colors in the (r' - Hα) - (r' - i') plane, we first identified 23,050 early A-type main-sequence (MS) star candidates in the Isaac Newton Photometric H-Alpha Survey (IPHAS) point source database that are located in Spitzer Galactic Legacy Mid-Plane Survey Extraordinaire Galactic plane fields. Imposing the requirement that they be detected in all seven Two Micron All Sky Survey and Infrared Astronomical Satellite bands led to a sample of 2692 candidate A-type stars with fully sampled 0.6 to 8 μm spectral energy distributions (SEDs). Optical classification spectra of 18 of the IPHAS candidate A-type MS stars showed that all but one could be well fitted using MS A-type templates, with the other being an A-type supergiant. Out of the 2692 A-type candidates 17 (0.6%) were found to have 8 μm excesses above the expected photospheric values. Taking into account non-A-Type contamination estimates, the 8 μm excess fraction is adjusted to ∼0.7%. The distances to these sources range from 0.7 to 2.5 kpc. Only 10 out of the 17 excess stars had been covered by Spitzer MIPSGAL survey fields, of which five had detectable excesses at 24 μm. For sources with excesses detected in at least two mid-IR wavelength bands, blackbody fits to the excess SEDs yielded temperatures ranging from 270 to 650 K, and bolometric luminosity ratios L IR /L * from 2.2 x 10 -3 - 1.9 x 10 -2 , with a mean value of 7.9 x 10 -3 (these bolometric luminosities are lower limits as cold dust is not detectable by this survey). Both the presence of mid-IR excesses and the derived bolometric luminosity ratios are consistent with many of these systems being in the planet-building transition phase between the early protoplanetary disk phase and the later debris disk phase.

  15. Hidden expectations within the Danish VET system

    DEFF Research Database (Denmark)

    Hjort-Madsen, Peder

    Researching the pressing retention and dropout problems of the Danish VET system (app. 20 pct. of a year group never achieve an upper secondary education) this paper takes its point of departure in the hypothesis that low performing students are kept in a marginal position (at the risk of dropping...... out) within the VET system, because of hidden expectations related to e.g. individualized responsibility, a certain student behavior (sitting still, participating actively), etc. By approaching the VET system as a cultural context (cultural praxis) the subtle reproductive mechanisms of the VET system...... are shown. With empirical examples from different introductory VET courses, it is shown how the school, the teachers and the students themselves are reproducing poor school performance and student background – being it gendered, ethnical or social – and hereby proving to the students, that school/education...

  16. Nuclear scissors modes and hidden angular momenta

    Energy Technology Data Exchange (ETDEWEB)

    Balbutsev, E. B., E-mail: balbuts@theor.jinr.ru; Molodtsova, I. V. [Joint Institute for Nuclear Research (Russian Federation); Schuck, P. [Université Paris-Sud, Institut de Physique Nucléaire, IN2P3–CNRS (France)

    2017-01-15

    The coupled dynamics of low-lying modes and various giant resonances are studied with the help of the Wigner Function Moments method generalized to take into account spin degrees of freedom and pair correlations simultaneously. The method is based on Time-Dependent Hartree–Fock–Bogoliubov equations. The model of the harmonic oscillator including spin–orbit potential plus quadrupole–quadrupole and spin–spin interactions is considered. New low-lying spin-dependent modes are analyzed. Special attention is paid to the scissors modes. A new source of nuclear magnetism, connected with counter-rotation of spins up and down around the symmetry axis (hidden angular momenta), is discovered. Its inclusion into the theory allows one to improve substantially the agreement with experimental data in the description of energies and transition probabilities of scissors modes.

  17. Improved hidden Markov model for nosocomial infections.

    Science.gov (United States)

    Khader, Karim; Leecaster, Molly; Greene, Tom; Samore, Matthew; Thomas, Alun

    2014-12-01

    We propose a novel hidden Markov model (HMM) for parameter estimation in hospital transmission models, and show that commonly made simplifying assumptions can lead to severe model misspecification and poor parameter estimates. A standard HMM that embodies two commonly made simplifying assumptions, namely a fixed patient count and binomially distributed detections is compared with a new alternative HMM that does not require these simplifying assumptions. Using simulated data, we demonstrate how each of the simplifying assumptions used by the standard model leads to model misspecification, whereas the alternative model results in accurate parameter estimates. © The Authors 2013. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

  18. Exact solution of the hidden Markov processes

    Science.gov (United States)

    Saakian, David B.

    2017-11-01

    We write a master equation for the distributions related to hidden Markov processes (HMPs) and solve it using a functional equation. Thus the solution of HMPs is mapped exactly to the solution of the functional equation. For a general case the latter can be solved only numerically. We derive an exact expression for the entropy of HMPs. Our expression for the entropy is an alternative to the ones given before by the solution of integral equations. The exact solution is possible because actually the model can be considered as a generalized random walk on a one-dimensional strip. While we give the solution for the two second-order matrices, our solution can be easily generalized for the L values of the Markov process and M values of observables: We should be able to solve a system of L functional equations in the space of dimension M -1 .

  19. Hidden fungi, emergent properties: endophytes and microbiomes.

    Science.gov (United States)

    Porras-Alfaro, Andrea; Bayman, Paul

    2011-01-01

    Endophytes are microorganisms that live within plant tissues without causing symptoms of disease. They are important components of plant microbiomes. Endophytes interact with, and overlap in function with, other core microbial groups that colonize plant tissues, e.g., mycorrhizal fungi, pathogens, epiphytes, and saprotrophs. Some fungal endophytes affect plant growth and plant responses to pathogens, herbivores, and environmental change; others produce useful or interesting secondary metabolites. Here, we focus on new techniques and approaches that can provide an integrative understanding of the role of fungal endophytes in the plant microbiome. Clavicipitaceous endophytes of grasses are not considered because they have unique properties distinct from other endophytes. Hidden from view and often overlooked, endophytes are emerging as their diversity, importance for plant growth and survival, and interactions with other organisms are revealed. Copyright © 2011 by Annual Reviews. All rights reserved.

  20. The elliptic genus and Hidden symmetry

    International Nuclear Information System (INIS)

    Jaffe, A.

    2001-01-01

    We study the elliptic genus (a partition function) in certain interacting, twist quantum field theories. Without twists, these theories have N=2 supersymmetry. The twists provide a regularization, and also partially break the supersymmetry. In spite of the regularization, one can establish a homotopy of the elliptic genus in a coupling parameter. Our construction relies on a priori estimates and other methods from constructive quantum field theory; this mathematical underpinning allows us to justify evaluating the elliptic genus at one endpoint of the homotopy. We obtain a version of Witten's proposed formula for the elliptic genus in terms of classical theta functions. As a consequence, the elliptic genus has a hidden SL(2,Z) symmetry characteristic of conformal theory, even though the underlying theory is not conformal. (orig.)

  1. The hidden biology of sponges and ctenophores.

    Science.gov (United States)

    Dunn, Casey W; Leys, Sally P; Haddock, Steven H D

    2015-05-01

    Animal evolution is often presented as a march toward complexity, with different living animal groups each representing grades of organization that arose through the progressive acquisition of complex traits. There are now many reasons to reject this classical hypothesis. Not only is it incompatible with recent phylogenetic analyses, but it is also an artifact of 'hidden biology', that is, blind spots to complex traits in non-model species. A new hypothesis of animal evolution, where many complex traits have been repeatedly gained and lost, is emerging. As we discuss here, key details of this new model hinge on a better understanding of the Porifera and Ctenophora, which have each been hypothesized to be sister to all other animals, but are poorly studied and often misrepresented. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Dynamic portfolio optimization across hidden market regimes

    DEFF Research Database (Denmark)

    Nystrup, Peter; Madsen, Henrik; Lindström, Erik

    2017-01-01

    Regime-based asset allocation has been shown to add value over rebalancing to static weights and, in particular, reduce potential drawdowns by reacting to changes in market conditions. The predominant approach in previous studies has been to specify in advance a static decision rule for changing...... the allocation based on the state of financial markets or the economy. In this article, model predictive control (MPC) is used to dynamically optimize a portfolio based on forecasts of the mean and variance of financial returns from a hidden Markov model with time-varying parameters. There are computational...... advantages to using MPC when estimates of future returns are updated every time a new observation becomes available, since the optimal control actions are reconsidered anyway. MPC outperforms a static decision rule for changing the allocation and realizes both a higher return and a significantly lower risk...

  3. Revealing the Hidden Curriculum in Higher Education

    DEFF Research Database (Denmark)

    Semper, José Víctor Orón; Blasco, Maribel

    2018-01-01

    The so-called ‘hidden curriculum’ (HC) is often presented as a counterproductive element in education, and many scholars argue that it should be eliminated, by being made explicit, in education in general and specifically in higher education (HE). The problem of the HC has not been solved...... by the transition from a teacher-centered education to a student-centered educational model that takes the student’s experience as the starting point of learning. In this article we turn to several philosophers of education (Dewey, Kohlberg, Whitehead, Peters and Knowles) to propose that HC can be made explicit...... this interpersonal relationship can be strengthened despite current challenges in HE....

  4. Revisiting the Phase Curves of WASP-43b: Confronting Re-analyzed Spitzer Data with Cloudy Atmospheres

    DEFF Research Database (Denmark)

    Mendonça, João M.; Malik, Matej; Demory, Brice-Olivier

    2018-01-01

    and have a finite cloud-top pressure. The multi-wavelength phase curves are naturally consistent with our cloudy atmospheres, except for the 4.5 μm phase curve, which requires the presence of enhanced carbon dioxide in the atmosphere of WASP-43b. Multi-phase emission spectra at higher spectral resolution......Recently acquired Hubble and Spitzer phase curves of the short-period hot Jupiter WASP-43b make it an ideal target for confronting theory with data. On the observational front, we re-analyze the 3.6 and 4.5 μm Spitzer phase curves and demonstrate that our improved analysis better removes residual...

  5. CRYSTALLINE SILICATES IN EVOLVED STARS. I. SPITZER/INFRARED SPECTROGRAPH SPECTROSCOPY OF IRAS 16456-3542, 18354-0638, AND 23239+5754

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, B. W.; Zhang, Ke [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Li, Aigen [Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211 (United States); Lisse, C. M., E-mail: bjiang@bnu.edu.cn, E-mail: kzhang@caltech.edu, E-mail: lia@missouri.edu, E-mail: carey.lisse@jhuapl.edu [Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723 (United States)

    2013-03-01

    We report the Spitzer Infrared Spectrograph (IRS) observations of three evolved stars: IRAS 16456-3542, 18354-0638, and 23239+5754. The 9.9-37.2 {mu}m Spitzer/IRS high-resolution spectra of these three sources exhibit rich sets of enstatite-dominated crystalline silicate emission features. IRAS 16456-3542 is extremely rich in crystalline silicates, with >90% of its silicate mass in crystalline form, the highest to date ever reported for crystalline silicate sources.

  6. Electronic hidden solder joint geometry characterization

    Science.gov (United States)

    Hsieh, Sheng-Jen

    2009-05-01

    To reduce the size of electronic equipment, multi-layer printed circuit board structures have become popular in recent years. As a result, the inspection of hidden solder joints between layers of boards has become increasingly difficult. Xray machines have been used for ball grid array (BGA) and hidden solder joint inspection; however, the equipment is costly and the inspection process is time consuming. In this paper, we investigate an active thermography approach to probing solder joint geometry. A set of boards having the same number of solder joints and amount of solder paste (0.061 g) was fabricated. Each solder joint had a different geometry. A semi-automated system was built to heat and then transfer each board to a chamber where an infrared camera was used to scan the board as it was cooling down. Two-thirds of the data set was used for model development and one-third was used for model evaluation. Both artificial neural network (ANN) and binary logistic regression models were constructed. Results suggest that solder joints with more surface area cool much faster than those with less surface area. In addition, both modeling approaches are consistent in predicting solder geometry; ANN had 85% accuracy and the regression model had 80%. This approach can potentially be used to test for cold solder joints prior to BGA assembly, since cold solder joints may have air gaps between the joint and the board and air is a poor heat conductor. Therefore, a cold solder joint may have a slower cooling rate than a normal one.

  7. SPITZER IRS SPECTRA OF LUMINOUS 8 μm SOURCES IN THE LARGE MAGELLANIC CLOUD: TESTING COLOR-BASED CLASSIFICATIONS

    International Nuclear Information System (INIS)

    Buchanan, Catherine L.; Kastner, Joel H.; Hrivnak, Bruce J.; Sahai, Raghvendra

    2009-01-01

    We present archival Spitzer Infrared Spectrograph (IRS) spectra of 19 luminous 8 μm selected sources in the Large Magellanic Cloud (LMC). The object classes derived from these spectra and from an additional 24 spectra in the literature are compared with classifications based on Two Micron All Sky Survey (2MASS)/MSX (J, H, K, and 8 μm) colors in order to test the 'JHK8' (Kastner et al.) classification scheme. The IRS spectra confirm the classifications of 22 of the 31 sources that can be classified under the JHK8 system. The spectroscopic classification of 12 objects that were unclassifiable in the JHK8 scheme allow us to characterize regions of the color-color diagrams that previously lacked spectroscopic verification, enabling refinements to the JHK8 classification system. The results of these new classifications are consistent with previous results concerning the identification of the most infrared-luminous objects in the LMC. In particular, while the IRS spectra reveal several new examples of asymptotic giant branch (AGB) stars with O-rich envelopes, such objects are still far outnumbered by carbon stars (C-rich AGB stars). We show that Spitzer IRAC/MIPS color-color diagrams provide improved discrimination between red supergiants and oxygen-rich and carbon-rich AGB stars relative to those based on 2MASS/MSX colors. These diagrams will enable the most luminous IR sources in Local Group galaxies to be classified with high confidence based on their Spitzer colors. Such characterizations of stellar populations will continue to be possible during Spitzer's warm mission through the use of IRAC [3.6]-[4.5] and 2MASS colors.

  8. Adaptive filtering for hidden node detection and tracking in networks.

    Science.gov (United States)

    Hamilton, Franz; Setzer, Beverly; Chavez, Sergio; Tran, Hien; Lloyd, Alun L

    2017-07-01

    The identification of network connectivity from noisy time series is of great interest in the study of network dynamics. This connectivity estimation problem becomes more complicated when we consider the possibility of hidden nodes within the network. These hidden nodes act as unknown drivers on our network and their presence can lead to the identification of false connections, resulting in incorrect network inference. Detecting the parts of the network they are acting on is thus critical. Here, we propose a novel method for hidden node detection based on an adaptive filtering framework with specific application to neuronal networks. We consider the hidden node as a problem of missing variables when model fitting and show that the estimated system noise covariance provided by the adaptive filter can be used to localize the influence of the hidden nodes and distinguish the effects of different hidden nodes. Additionally, we show that the sequential nature of our algorithm allows for tracking changes in the hidden node influence over time.

  9. Market impact and trading profile of hidden orders in stock markets.

    Science.gov (United States)

    Moro, Esteban; Vicente, Javier; Moyano, Luis G; Gerig, Austin; Farmer, J Doyne; Vaglica, Gabriella; Lillo, Fabrizio; Mantegna, Rosario N

    2009-12-01

    We empirically study the market impact of trading orders. We are specifically interested in large trading orders that are executed incrementally, which we call hidden orders. These are statistically reconstructed based on information about market member codes using data from the Spanish Stock Market and the London Stock Exchange. We find that market impact is strongly concave, approximately increasing as the square root of order size. Furthermore, as a given order is executed, the impact grows in time according to a power law; after the order is finished, it reverts to a level of about 0.5-0.7 of its value at its peak. We observe that hidden orders are executed at a rate that more or less matches trading in the overall market, except for small deviations at the beginning and end of the order.

  10. Does violence affect the use of contraception? Identifying the hidden factors from rural India

    Directory of Open Access Journals (Sweden)

    Nishikant Singh

    2017-01-01

    Full Text Available Purpose: The objective of this study is to investigates the relationship between domestic violence and use of contraception among married women in rural India. Data: Third round of National Family Health Survey (NFHS-III. Methodology: Cross tabulation as bivariate analysis and Binary Logistic Regression as multivariate analysis has been employed to fulfill the objective. Findings: The result shows that there are several hidden factors. between physical violence and contraception use. Alternate explanatory variables are significantly affected the use of contraception. With physical violence which reflects that there is a relationship between physical violence and socioeconomic status such as education, awareness, empowerment of women and subsequently the use of contraception. Originality/value: The paper throws light on the hidden factors which are obstacle in use of contraception with physical violence. Results of this study have potentially important implications for programs aimed at preventing violence and promoting family planning programs.

  11. Chimpanzees modify intentional gestures to coordinate a search for hidden food

    Science.gov (United States)

    Roberts, Anna Ilona; Vick, Sarah-Jane; Roberts, Sam George Bradley; Menzel, Charles R

    2014-01-01

    Humans routinely communicate to coordinate their activities, persisting and elaborating signals to pursue goals that cannot be accomplished individually. Communicative persistence is associated with complex cognitive skills such as intentionality, because interactants modify their communication in response to another's understanding of their meaning. Here we show that two language-trained chimpanzees effectively use intentional gestures to coordinate with an experimentally-naïve human to retrieve hidden food, providing some of the most compelling evidence to date for the role of communicative flexibility in successful coordination in nonhumans. Both chimpanzees (named Panzee and Sherman) increase the rate of non-indicative gestures when the experimenter approaches the location of the hidden food. Panzee also elaborates her gestures in relation to the experimenter's pointing, which enables her to find food more effectively than Sherman. Communicative persistence facilitates effective communication during behavioural coordination and is likely to have been important in shaping language evolution. PMID:24430433

  12. Engineering Algorithms for Finding Patterns in Biological Data

    DEFF Research Database (Denmark)

    Nielsen, Jesper

    2011-01-01

    of the quartet distance between trees. The common denominator is the interest in the design of both theoretically and practically fast algorithms. Related to molecular similarity we show how arranging a set of bitstrings into a tree can significantly speed up searches for bitstrings similar to a query bitstring...... analyze data from an experiment on exosome knockout. The exosome is a complex with a role in RNA degradation. We find that knockout of the exosome stabilize hitherto unknown RNA transcripts upstream active transcription start sites. With respect to Hidden Markov Models we develop two fast algorithms. We...... show that formulating the Hidden Markov Model framework using linear algebra allows one to solve the traditional problems using parallel reduction. This approach increases the total amount of work, but can still lead to significant speed-ups on Hidden Markov Models with a small state space. For Hidden...

  13. Sociocultural Dimension of Hidden Content in a Professional Language Curriculum

    Directory of Open Access Journals (Sweden)

    Ekaterina E. Shishlova

    2017-12-01

    Full Text Available Introduction: studying curriculum as a pedagogical problem has traditionally been reduced to the analysis of its explicit content, set in official educational documents. However, a much less studied hidden content plays a significant role in education. So, what is the role of the hidden curriculum during professional language training? The purpose of the article is to determine the potential impact of hidden curriculum on students’ conceptual worldview. Comparing the worldview presented in textbooks with students’ one has allowed us to estimate the rate of influence of hidden curr iculum. Materials and Methods: the methodological basis of the work is the cultural concept of personalityoriented education. The methodology for studying the role of hidden curriculum includes four stages: at the first stage, the authors set the criteria for selecting textbooks for analysis and do the selection; at the second stage, the authors select sociocultural concepts for analysis; at the third stage, the scheme of analysis is designed and the analysis of textbooks is done; at the fourth stage, the authors identify the potential influence of hidden curriculum on students’ conceptual worldview. Results: the structure of hidden curriculum has been determined and the scheme for analysing its subject component has been developed. The authors have identified a significant influence of hidden curriculum on students’ worldview, which represents the scientific novelty of the article. Discussion and Conclusions: the article gives the definition of a hidden curriculum which is new for Russian pedagogy and presents a methodology for its analysis in EFL textbooks. That analysis is recommended to be conducted when selecting teaching materials both i n languages and other humanities.

  14. Properties of the Irregular Satellite System around Uranus Inferred from K2 , Herschel , and Spitzer Observations

    Energy Technology Data Exchange (ETDEWEB)

    Farkas-Takács, A.; Kiss, Cs.; Pál, A.; Molnár, L.; Szabó, Gy. M.; Hanyecz, O.; Sárneczky, K.; Szabó, R.; Marton, G.; Szakáts, R.; Kiss, L. L. [Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Konkoly Thege Miklós út 15-17, H-1121 Budapest (Hungary); Mommert, M. [Department of Physics and Astronomy, Northern Arizona University, P.O. Box 6010, Flagstaff, AZ 86011 (United States); Müller, T., E-mail: farkas.aniko@csfk.mta.hu [Max-Plank-Institut für extraterrestrsiche Pyhsik, Garching (Germany)

    2017-09-01

    In this paper, we present visible-range light curves of the irregular Uranian satellites Sycorax, Caliban, Prospero, Ferdinand, and Setebos taken with the Kepler Space Telescope over the course of the K2 mission. Thermal emission measurements obtained with the Herschel /PACS and Spitzer /MIPS instruments of Sycorax and Caliban were also analyzed and used to determine size, albedo, and surface characteristics of these bodies. We compare these properties with the rotational and surface characteristics of irregular satellites in other giant planet systems and also with those of main belt and Trojan asteroids and trans-Neptunian objects. Our results indicate that the Uranian irregular satellite system likely went through a more intense collisional evolution than the irregular satellites of Jupiter and Saturn. Surface characteristics of Uranian irregular satellites seem to resemble the Centaurs and trans-Neptunian objects more than irregular satellites around other giant planets, suggesting the existence of a compositional discontinuity in the young solar system inside the orbit of Uranus.

  15. NEWLY IDENTIFIED EXTENDED GREEN OBJECTS (EGOs) FROM THE SPITZER GLIMPSE II SURVEY. I. CATALOG

    International Nuclear Information System (INIS)

    Chen, Xi; Gan, Cong-Gui; Shen, Zhi-Qiang; Ellingsen, Simon P.; Titmarsh, Anita; He, Jin-Hua

    2013-01-01

    We have produced a catalog containing 98 newly identified massive young stellar object (MYSO) candidates associated with ongoing outflows (known as extended green objects, or EGOs). These have been identified from the Spitzer Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE) II data set and our new identifications increase the number of known EGOs to ∼400 in our Galaxy, adding to the ∼300 previously identified EGOs reported by Cyganowski et al. from the GLIMPSE I survey. The high detection rate (∼70%) of 95 GHz class I methanol masers achieved in a survey toward 57 of these new EGOs with the Mopra 22 m radio telescope demonstrates that the new EGOs are associated with outflows. Investigations of the mid-infrared properties and physical associations with other star formation tracers (e.g., infrared dark clouds, class I and II methanol masers, and millimeter Bolocam Galactic Plane Survey sources) reveal that the newly identified EGOs are very similar in nature to those in the sample of Cyganowski et al. All of the observational evidence supports the hypothesis that EGOs correspond to MYSOs at the earliest evolutionary stage, with ongoing outflow activity, and active rapid accretion.

  16. Stellar mass estimation based on IRAC photometry for Spitzer SWIRE-field galaxies

    International Nuclear Information System (INIS)

    Zhu Yinan; Wu Hong; Li Haining; Cao Chen

    2010-01-01

    We analyze the feasibility of estimating the stellar mass of galaxies by mid-infrared luminosities based on a large sample of galaxies cross-identified from Spitzer SWIRE fields and the SDSS spectrographic survey. We derived the formulae to calculate the stellar mass by using IRAC 3.6 μm and 4.5 μm luminosities. The mass-to-luminosity ratios of IRAC 3.6 μm and 4.5 μm luminosities are more sensitive to the star formation history of galaxies than to other factors, such as the intrinsic extinction, metallicity and star formation rate. To remove the effect of star formation history, we used g - r color to recalibrate the formulae and obtain a better result. Researchers must be more careful when estimating the stellar mass of low metallicity galaxies using our formulae. Due to the emission from dust heated by the hottest young stars, luminous infrared galaxies present higher IRAC 4.5 μm luminosities compared to IRAC 3.6 μm luminosities. For most of type-II AGNs, the nuclear activity cannot enhance 3.6 μm and 4.5 μm luminosities compared with normal galaxies. Star formation in our AGN-hosting galaxies is also very weak, almost all of which are early-type galaxies.

  17. VizieR Online Data Catalog: Spitzer h and {chi} Persei candidate members (Cloutier+, 2014)

    Science.gov (United States)

    Cloutier, R.; Currie, T.; Rieke, G. H.; Kenyon, S. J.; Balog, Z.; Jayawardhana, R.

    2017-08-01

    The IRAC (Fazio et al. 2004ApJS..154...39F) observed h and {chi} Persei on October 30, 2008 (AOR IDs 2182740, 21828608, 21828096, 21828864, 21828352, and 2182912). Solar activity was normal to below average. Zodical emission ranged between ~0.02 and 2 MJy/sr from 3.6 um to 8 um. Image processing and photometry were performed separately for the short-exposure and long-exposure frames. The MIPS (Rieke et al. 2004ApJS..154...25R) imaged h and {chi} Persei on 2008 March 15-16, 2008 October 25-26, and 2009 March 26 and 29 as a part of General Observation Programs 40690 and 50664 (PI: Scott Kenyon). To identify and characterize disks surrounding h and {chi} Persei stars, we combine Spitzer data with optical/near-IR data for likely cluster members, updating the list from Currie et al. (2010, J/ApJS/186/191) with a more accurate one of 13956 stars (Table 1). (3 data files).

  18. Context Tree Estimation in Variable Length Hidden Markov Models

    OpenAIRE

    Dumont, Thierry

    2011-01-01

    We address the issue of context tree estimation in variable length hidden Markov models. We propose an estimator of the context tree of the hidden Markov process which needs no prior upper bound on the depth of the context tree. We prove that the estimator is strongly consistent. This uses information-theoretic mixture inequalities in the spirit of Finesso and Lorenzo(Consistent estimation of the order for Markov and hidden Markov chains(1990)) and E.Gassiat and S.Boucheron (Optimal error exp...

  19. Hidden photon dark matter search with large metallic mirror

    International Nuclear Information System (INIS)

    Doebrich, Babette; Lindner, Axel; Daumiller, Kai; Engel, Ralph; Roth, Markus; Kowalski, Marek

    2014-10-01

    If Dark Matter is composed of hidden-sector photons that kinetically mix with photons of the visible sector, then Dark Matter has a tiny oscillating electric field component. Its presence would lead to a small amount of visible radiation being emitted from a conducting surface, with the photon frequency given approximately by the mass of the hidden photon. Here, we report on experimental efforts that have started recently to search for such hidden photon Dark Matter in the (sub-)eV regime with a prototype mirror for the Auger fluorescence detector at the Karlsruhe Institute for Technology.

  20. Hidden Area and Mechanical Nonlinearities in Freestanding Graphene

    Science.gov (United States)

    Nicholl, Ryan J. T.; Lavrik, Nickolay V.; Vlassiouk, Ivan; Srijanto, Bernadeta R.; Bolotin, Kirill I.

    2017-06-01

    We investigated the effect of out-of-plane crumpling on the mechanical response of graphene membranes. In our experiments, stress was applied to graphene membranes using pressurized gas while the strain state was monitored through two complementary techniques: interferometric profilometry and Raman spectroscopy. By comparing the data obtained through these two techniques, we determined the geometric hidden area which quantifies the crumpling strength. While the devices with hidden area ˜0 % obeyed linear mechanics with biaxial stiffness 428 ±10 N /m , specimens with hidden area in the range 0.5%-1.0% were found to obey an anomalous nonlinear Hooke's law with an exponent ˜0.1 .

  1. Suppressing the QCD axion abundance by hidden monopoles

    International Nuclear Information System (INIS)

    Kawasaki, Masahiro

    2015-11-01

    We study the Witten effect of hidden monopoles on the QCD axion dynamics, and show that its abundance as well as isocurvature perturbations can be significantly suppressed if there is a sufficient amount of hidden monopoles. When the hidden monopoles make up a significant fraction of dark matter, the Witten effect suppresses the abundance of axion with the decay constant smaller than 10 12 GeV. The cosmological domain wall problem of the QCD axion can also be avoided, relaxing the upper bound on the decay constant when the Peccei-Quinn symmetry is spontaneously broken after inflation.

  2. Multilayer Neural Networks with Extensively Many Hidden Units

    International Nuclear Information System (INIS)

    Rosen-Zvi, Michal; Engel, Andreas; Kanter, Ido

    2001-01-01

    The information processing abilities of a multilayer neural network with a number of hidden units scaling as the input dimension are studied using statistical mechanics methods. The mapping from the input layer to the hidden units is performed by general symmetric Boolean functions, whereas the hidden layer is connected to the output by either discrete or continuous couplings. Introducing an overlap in the space of Boolean functions as order parameter, the storage capacity is found to scale with the logarithm of the number of implementable Boolean functions. The generalization behavior is smooth for continuous couplings and shows a discontinuous transition to perfect generalization for discrete ones

  3. Alleviating hidden hunger. Approaches that work

    International Nuclear Information System (INIS)

    Kennedy, E.; Mannar, V.; Iyengar, V.

    2003-01-01

    The world has come a long way in understanding the nature, magnitude and range of solutions to micronutrient malnutrition - often called 'hidden hunger'. The most sustainable solutions - that is those that are likely to be maintained in the long term - almost surely will include food-based approaches including diet diversity, food fortification and biofortification. Food fortification and biofortification could be some of the most cost-effective of all public health interventions and thus within the economic reach of even the world's poorest. In order to implement them in a sustainable manner, a combination of technical, operational, economic, behavioural and political factors need to be addressed. In some ways the technological issues are the easiest. Because of attention to research, we now have a variety of ways for both single and multiple micronutrients to reach the target population. We also know what is needed in order to ensure delivery systems. The key factor for continued success in reducing micronutrient malnutrition through fortification is a political commitment at the national and international level and creating effective public-private partnerships at the national level. The payoff for eliminating hidden hunger through nutrient fortification is enormous and few other public health interventions offer such a promising health, nutrition and economic success story. Nuclear and isotopic techniques are valuable tools in helping to meet the multifaceted challenges posed by nutritional disorders affecting the entire human life span (embryonic to elderly). Among the numerous applications available, isotopic techniques are uniquely well suited for targeting and tracking progress in food and nutrition development programmes (See box: How Nutrients are Tracked). These include: use of the stable isotopes of iron (Fe) and zinc (Zn) as a kind of gold standard in studies of their bioavailability from foods; trace element bioavailability and pool sizes for

  4. A "hidden" co-crystal of caffeine and adipic acid.

    Science.gov (United States)

    Bucar, Dejan-Kresimir; Henry, Rodger F; Lou, Xiaochun; Borchardt, Thomas B; Zhang, Geoff G Z

    2007-02-07

    Co-crystal formation between caffeine and adipic acid has been explored over the years without success; utilizing the newly developed co-crystal screening method, we have finally discovered this "hidden" caffeine and adipic acid co-crystal.

  5. New limits on hidden photons from past electron beam dumps

    International Nuclear Information System (INIS)

    Andreas, Sarah; Niebuhr, Carsten; Ringwald, Andreas

    2012-09-01

    Hidden sectors with light extra U(1) gauge bosons, so called hidden photons, have recently attracted some attention because they are a common feature of physics beyond the Standard Model like string theory and SUSY and additionally are phenomenologically of great interest regarding recent astrophysical observations. The hidden photon is already constrained by various laboratory experiments and presently searched for in running as well as upcoming experiments. We summarize the current status of limits on hidden photons from past electron beam dump experiments including two new limits from such experiments at KEK and Orsay that have so far not been considered. All our limits take into account the experimental acceptances obtained from Monte Carlo simulations.

  6. Hidden Neural Networks: A Framework for HMM/NN Hybrids

    DEFF Research Database (Denmark)

    Riis, Søren Kamaric; Krogh, Anders Stærmose

    1997-01-01

    This paper presents a general framework for hybrids of hidden Markov models (HMM) and neural networks (NN). In the new framework called hidden neural networks (HNN) the usual HMM probability parameters are replaced by neural network outputs. To ensure a probabilistic interpretation the HNN is nor...... HMMs on TIMIT continuous speech recognition benchmarks. On the task of recognizing five broad phoneme classes an accuracy of 84% is obtained compared to 76% for a standard HMM. Additionally, we report a preliminary result of 69% accuracy on the TIMIT 39 phoneme task......This paper presents a general framework for hybrids of hidden Markov models (HMM) and neural networks (NN). In the new framework called hidden neural networks (HNN) the usual HMM probability parameters are replaced by neural network outputs. To ensure a probabilistic interpretation the HNN...

  7. New limits on hidden photons from past electron beam dumps

    Energy Technology Data Exchange (ETDEWEB)

    Andreas, Sarah; Niebuhr, Carsten; Ringwald, Andreas

    2012-09-15

    Hidden sectors with light extra U(1) gauge bosons, so called hidden photons, have recently attracted some attention because they are a common feature of physics beyond the Standard Model like string theory and SUSY and additionally are phenomenologically of great interest regarding recent astrophysical observations. The hidden photon is already constrained by various laboratory experiments and presently searched for in running as well as upcoming experiments. We summarize the current status of limits on hidden photons from past electron beam dump experiments including two new limits from such experiments at KEK and Orsay that have so far not been considered. All our limits take into account the experimental acceptances obtained from Monte Carlo simulations.

  8. A Novel Method for Decoding Any High-Order Hidden Markov Model

    Directory of Open Access Journals (Sweden)

    Fei Ye

    2014-01-01

    Full Text Available This paper proposes a novel method for decoding any high-order hidden Markov model. First, the high-order hidden Markov model is transformed into an equivalent first-order hidden Markov model by Hadar’s transformation. Next, the optimal state sequence of the equivalent first-order hidden Markov model is recognized by the existing Viterbi algorithm of the first-order hidden Markov model. Finally, the optimal state sequence of the high-order hidden Markov model is inferred from the optimal state sequence of the equivalent first-order hidden Markov model. This method provides a unified algorithm framework for decoding hidden Markov models including the first-order hidden Markov model and any high-order hidden Markov model.

  9. A two particle hidden sector and the oscillations with photons

    Science.gov (United States)

    Alvarez, Pedro D.; Arias, Paola; Maldonado, Carlos

    2018-01-01

    We present a detailed study of the oscillations and optical properties for vacuum, in a model for the dark sector that contains axion-like particles and hidden photons. We provide bounds for the couplings versus the mass, using current results from ALPS-I and PVLAS. We also discuss the challenges for the detection of models with more than one hidden particle in light shining trough wall-like experiments.

  10. Constraints and hidden symmetry in two-dimensional gravity

    Energy Technology Data Exchange (ETDEWEB)

    Barcelos-Neto, J. (Instituto de Fisica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro 21945-970 (Brazil))

    1994-01-15

    We study the hidden symmetry of Polyakov two-dimensional gravity by means of first-class constraints. These are obtained from the combination of Fourier mode expansions of the usual (second-class) constraints of the theory. We show that, more than the usual SL(2,[ital R]), there is a hidden Virasoro symmetry in the theory. The results of the above analysis are also confirmed from the point of view of a geometrical symplectic treatment.

  11. Hidden charged dark matter and chiral dark radiation

    Science.gov (United States)

    Ko, P.; Nagata, Natsumi; Tang, Yong

    2017-10-01

    In the light of recent possible tensions in the Hubble constant H0 and the structure growth rate σ8 between the Planck and other measurements, we investigate a hidden-charged dark matter (DM) model where DM interacts with hidden chiral fermions, which are charged under the hidden SU(N) and U(1) gauge interactions. The symmetries in this model assure these fermions to be massless. The DM in this model, which is a Dirac fermion and singlet under the hidden SU(N), is also assumed to be charged under the U(1) gauge symmetry, through which it can interact with the chiral fermions. Below the confinement scale of SU(N), the hidden quark condensate spontaneously breaks the U(1) gauge symmetry such that there remains a discrete symmetry, which accounts for the stability of DM. This condensate also breaks a flavor symmetry in this model and Nambu-Goldstone bosons associated with this flavor symmetry appear below the confinement scale. The hidden U(1) gauge boson and hidden quarks/Nambu-Goldstone bosons are components of dark radiation (DR) above/below the confinement scale. These light fields increase the effective number of neutrinos by δNeff ≃ 0.59 above the confinement scale for N = 2, resolving the tension in the measurements of the Hubble constant by Planck and Hubble Space Telescope if the confinement scale is ≲1 eV. DM and DR continuously scatter with each other via the hidden U(1) gauge interaction, which suppresses the matter power spectrum and results in a smaller structure growth rate. The DM sector couples to the Standard Model sector through the exchange of a real singlet scalar mixing with the Higgs boson, which makes it possible to probe our model in DM direct detection experiments. Variants of this model are also discussed, which may offer alternative ways to investigate this scenario.

  12. Hidden Terminal-Aware Contention Resolution with an Optimal Distribution

    OpenAIRE

    Ghadimi, Euhanna; Soldati, Pablo; Österlind, Fredrik; Zhang, Haibo; Johansson, Mikael

    2011-01-01

    Achieving low-power operation in wireless sensor networks with high data load or bursty traffic is challenging. The hidden terminal problem is aggravated with increased amounts of data in which traditional backoff-based contention resolution mechanisms fail or induce high latency and energy costs. We analyze and optimize Strawman, a receiver-initiated contention resolution mechanism that copes with hidden terminals. We propose new techniques to boost the performance of Strawman while keeping ...

  13. Rare Z boson decays to a hidden sector

    Science.gov (United States)

    Blinov, Nikita; Izaguirre, Eder; Shuve, Brian

    2018-01-01

    We demonstrate that rare decays of the Standard Model Z boson can be used to discover and characterize the nature of new hidden-sector particles. We propose new searches for these particles in soft, high-multiplicity leptonic final states at the Large Hadron Collider. The proposed searches are sensitive to low-mass particles produced in Z decays, and we argue that these striking signatures can shed light on the hidden-sector couplings and mechanism for mass generation.

  14. Aluminium Diphosphamethanides: Hidden Frustrated Lewis Pairs.

    Science.gov (United States)

    Styra, Steffen; Radius, Michael; Moos, Eric; Bihlmeier, Angela; Breher, Frank

    2016-07-04

    The synthesis and characterisation of two aluminium diphosphamethanide complexes, [Al(tBu)2 {κ(2) P,P'-Mes*PCHPMes*}] (3) and [Al(C6 F5 )2 {κ(2) P,P'-Mes*PCHPMes*}] (4), and the silylated analogue, Mes*PCHP(SiMe3 )Mes* (5), are reported. The aluminium complexes feature four-membered PCPAl core structures consisting of diphosphaallyl ligands. The silylated phosphine 5 was found to be a valuable precursor for the synthesis of 4 as it cleanly reacts with the diaryl aluminium chloride [(C6 F5 )2 AlCl]2 . The aluminium complex 3 reacts with molecular dihydrogen at room temperature under formation of the acyclic σ(2) λ(3) ,σ(3) λ(3) -diphosphine Mes*PCHP(H)Mes* and the corresponding dialkyl aluminium hydride [tBu2 AlH]3 . Thus, 3 belongs to the family of so-called hidden frustrated Lewis pairs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Natural inflation with hidden scale invariance

    Directory of Open Access Journals (Sweden)

    Neil D. Barrie

    2016-05-01

    Full Text Available We propose a new class of natural inflation models based on a hidden scale invariance. In a very generic Wilsonian effective field theory with an arbitrary number of scalar fields, which exhibits scale invariance via the dilaton, the potential necessarily contains a flat direction in the classical limit. This flat direction is lifted by small quantum corrections and inflation is realised without need for an unnatural fine-tuning. In the conformal limit, the effective potential becomes linear in the inflaton field, yielding to specific predictions for the spectral index and the tensor-to-scalar ratio, being respectively: ns−1≈−0.025(N⋆60−1 and r≈0.0667(N⋆60−1, where N⋆≈30–65 is a number of efolds during observable inflation. This predictions are in reasonable agreement with cosmological measurements. Further improvement of the accuracy of these measurements may turn out to be critical in falsifying our scenario.

  16. Academic mobbing: hidden health hazard at workplace.

    Science.gov (United States)

    Khoo, Sb

    2010-01-01

    Academic mobbing is a non-violent, sophisticated, 'ganging up' behaviour adopted by academicians to "wear and tear" a colleague down emotionally through unjustified accusation, humiliation, general harassment and emotional abuse. These are directed at the target under a veil of lies and justifications so that they are "hidden" to others and difficult to prove. Bullies use mobbing activities to hide their own weaknesses and incompetence. Targets selected are often intelligent, innovative high achievers, with good integrity and principles. Mobbing activities appear trivial and innocuous on its own but the frequency and pattern of their occurrence over long period of time indicates an aggressive manipulation to "eliminate" the target. Mobbing activities typically progress through five stereotypical phases that begins with an unsolved minor conflict between two workers and ultimately escalates into a senseless mobbing whereby the target is stigmatized and victimized to justify the behaviours of the bullies. The result is always physical, mental, social distress or illness and, most often, expulsion of target from the workplace. Organizations are subjected to great financial loss, loss of key workers and a tarnished public image and reputation. Public awareness, education, effective counselling, establishment of anti-bullying policies and legislations at all levels are necessary to curb academic mobbing. General practitioners (GPs) play an important role in supporting patients subjected to mental and physical health injury caused by workplace bullying and mobbing.

  17. Search algorithms, hidden labour and information control

    Directory of Open Access Journals (Sweden)

    Paško Bilić

    2016-06-01

    Full Text Available The paper examines some of the processes of the closely knit relationship between Google’s ideologies of neutrality and objectivity and global market dominance. Neutrality construction comprises an important element sustaining the company’s economic position and is reflected in constant updates, estimates and changes to utility and relevance of search results. Providing a purely technical solution to these issues proves to be increasingly difficult without a human hand in steering algorithmic solutions. Search relevance fluctuates and shifts through continuous tinkering and tweaking of the search algorithm. The company also uses third parties to hire human raters for performing quality assessments of algorithmic updates and adaptations in linguistically and culturally diverse global markets. The adaptation process contradicts the technical foundations of the company and calculations based on the initial Page Rank algorithm. Annual market reports, Google’s Search Quality Rating Guidelines, and reports from media specialising in search engine optimisation business are analysed. The Search Quality Rating Guidelines document provides a rare glimpse into the internal architecture of search algorithms and the notions of utility and relevance which are presented and structured as neutral and objective. Intertwined layers of ideology, hidden labour of human raters, advertising revenues, market dominance and control are discussed throughout the paper.

  18. Hidden Markov Model for Stock Trading

    Directory of Open Access Journals (Sweden)

    Nguyet Nguyen

    2018-03-01

    Full Text Available Hidden Markov model (HMM is a statistical signal prediction model, which has been widely used to predict economic regimes and stock prices. In this paper, we introduce the application of HMM in trading stocks (with S&P 500 index being an example based on the stock price predictions. The procedure starts by using four criteria, including the Akaike information, the Bayesian information, the Hannan Quinn information, and the Bozdogan Consistent Akaike Information, in order to determine an optimal number of states for the HMM. The selected four-state HMM is then used to predict monthly closing prices of the S&P 500 index. For this work, the out-of-sample R OS 2 , and some other error estimators are used to test the HMM predictions against the historical average model. Finally, both the HMM and the historical average model are used to trade the S&P 500. The obtained results clearly prove that the HMM outperforms this traditional method in predicting and trading stocks.

  19. Hidden Heroes: America's Military Caregivers - Executive Summary.

    Science.gov (United States)

    Ramchand, Rajeev; Tanielian, Terri; Fisher, Michael P; Vaughan, Christine Anne; Trail, Thomas E; Epley, Caroline; Voorhies, Phoenix; Robbins, Michael; Robinson, Eric; Ghosh-Dastidar, Bonnie

    2014-01-01

    While much has been written about the role of caregiving for the elderly and chronically ill and for children with special needs, little is known about "military caregivers"-the population of those who care for wounded, ill, and injured military personnel and veterans. These caregivers play an essential role in caring for injured or wounded service members and veterans. This enables those for whom they are caring to live better quality lives, and can result in faster and improved rehabilitation and recovery. Yet playing this role can impose a substantial physical, emotional, and financial toll on caregivers. This article distills a longer report, Hidden Heroes: America's Military Caregivers , which describes the results of a study designed to describe the magnitude of military caregiving in the United States today, as well as to identify gaps in the array of programs, policies, and initiatives designed to support military caregivers. Improving military caregivers' well-being and ensuring their continued ability to provide care will require multifaceted approaches to reducing the current burdens caregiving may impose, and bolstering their ability to serve as caregivers more effectively. Given the systematic differences among military caregiver groups, it is also important that tailored approaches meet the unique needs and characteristics of post-9/11 caregivers.

  20. Dietary phytate, zinc and hidden zinc deficiency.

    Science.gov (United States)

    Sandstead, Harold H; Freeland-Graves, Jeanne H

    2014-10-01

    Epidemiological data suggest at least one in five humans are at risk of zinc deficiency. This is in large part because the phytate in cereals and legumes has not been removed during food preparation. Phytate, a potent indigestible ligand for zinc prevents it's absorption. Without knowledge of the frequency of consumption of foods rich in phytate, and foods rich in bioavailable zinc, the recognition of zinc deficiency early in the illness may be difficult. Plasma zinc is insensitive to early zinc deficiency. Serum ferritin concentration≤20μg/L is a potential indirect biomarker. Early effects of zinc deficiency are chemical, functional and may be "hidden". The clinical problem is illustrated by 2 studies that involved US Mexican-American children, and US premenopausal women. The children were consuming home diets that included traditional foods high in phytate. The premenopausal women were not eating red meat on a regular basis, and their consumption of phytate was mainly from bran breakfast cereals. In both studies the presence of zinc deficiency was proven by functional responses to controlled zinc treatment. In the children lean-mass, reasoning, and immunity were significantly affected. In the women memory, reasoning, and eye-hand coordination were significantly affected. A screening self-administered food frequency questionnaire for office might help caregiver's identify patients at risk of zinc deficiency. Copyright © 2014 Elsevier GmbH. All rights reserved.

  1. Interpretation of non-Markovian stochastic Schroedinger equations as a hidden-variable theory

    International Nuclear Information System (INIS)

    Gambetta, Jay; Wiseman, H.M.

    2003-01-01

    Do diffusive non-Markovian stochastic Schroedinger equations (SSEs) for open quantum systems have a physical interpretation? In a recent paper [Phys. Rev. A 66, 012108 (2002)] we investigated this question using the orthodox interpretation of quantum mechanics. We found that the solution of a non-Markovian SSE represents the state the system would be in at that time if a measurement was performed on the environment at that time, and yielded a particular result. However, the linking of solutions at different times to make a trajectory is, we concluded, a fiction. In this paper we investigate this question using the modal (hidden variable) interpretation of quantum mechanics. We find that the noise function z(t) appearing in the non-Markovian SSE can be interpreted as a hidden variable for the environment. That is, some chosen property (beable) of the environment has a definite value z(t) even in the absence of measurement on the environment. The non-Markovian SSE gives the evolution of the state of the system 'conditioned' on this environment hidden variable. We present the theory for diffusive non-Markovian SSEs that have as their Markovian limit SSEs corresponding to homodyne and heterodyne detection, as well as one which has no Markovian limit

  2. Using the internet to research hidden populations of illicit drug users: a review.

    Science.gov (United States)

    Miller, Peter G; Sønderlund, Anders L

    2010-09-01

    To review the current research of hidden populations of illicit drugs users using web-based methods and discuss major advantages and disadvantages. Systematic review of 16 databases, including PubMed, PsycINFO (EBSCOhost), CSA Sociological Abstracts, Expanded Academic ASAP and Google Scholar. Substances researched were most commonly 'party/club drugs' (such as ecstasy) and cannabis. All of the studies reviewed concluded that the internet is a useful tool for reaching hidden populations, but is likely to impose some bias in samples. Advantages include: access to previously under-researched target groups; speed; international applications; increased ease of data entry; and improved confidentiality for respondents. The major disadvantage is a lack of representativeness of samples. Internet research is successful at accessing hidden populations of illicit drugs users, when appropriately targeted and provides unprecedented opportunities for research across a wide range of topics within the addictions field. Findings are unlikely to be generalisable to the general public, but appropriate for describing target populations.

  3. Constraints on dark matter particles charged under a hidden gauge group from primordial black holes

    International Nuclear Information System (INIS)

    Dai, De-Chang; Stojkovic, Dejan; Freese, Katherine

    2009-01-01

    In order to accommodate increasingly tighter observational constraints on dark matter, several models have been proposed recently in which dark matter particles are charged under some hidden gauge group. Hidden gauge charges are invisible for the standard model particles, hence such scenarios are very difficult to constrain directly. However black holes are sensitive to all gauge charges, whether they belong to the standard model or not. Here, we examine the constraints on the possible values of the dark matter particle mass and hidden gauge charge from the evolution of primordial black holes. We find that the existence of the primordial black holes with reasonable mass is incompatible with dark matter particles whose charge to mass ratio is of the order of one. For dark matter particles whose charge to mass ratio is much less than one, we are able to exclude only heavy dark matter in the mass range of 10 11 GeV–10 16 GeV. Finally, for dark matter particles whose charge to mass ratio is much greater than one, there are no useful limits coming from primordial black holes

  4. Employing open/hidden administration in psychotherapy research: A randomized-controlled trial of expressive writing

    Science.gov (United States)

    Tondorf, Theresa; Kaufmann, Lisa-Katrin; Degel, Alexander; Locher, Cosima; Birkhäuer, Johanna; Gerger, Heike; Ehlert, Ulrike

    2017-01-01

    Psychotherapy has been shown to be effective, but efforts to prove specific effects by placebo-controlled trials have been practically and conceptually hampered. We propose that adopting open/hidden designs from placebo research would offer a possible way to establish specificity in psychotherapy. Therefore, we tested the effects of providing opposing treatment rationales in an online expressive writing intervention on affect in healthy subjects. Results indicate that it was possible to conduct the expressive writing intervention both covertly and openly, but that participants in the hidden administration condition did not fully benefit from the otherwise effective expressive writing intervention in the long-run. Effect sizes between open and hidden administration groups were comparable to pre-post effect sizes of the intervention. While this finding is important for the understanding of psychotherapy's effects per se, it also proves that alternative research approaches to establish specificity are feasible and informative in psychotherapy research. Trial registration: German Clinical Trials Register DRKS00009428 PMID:29176768

  5. Hidden costs: A Study of the Characteristics of the Articles Published in Brazilian Accounting Journals

    Directory of Open Access Journals (Sweden)

    Maicon Manoel Benin

    2016-09-01

    Full Text Available This study analyzes the characteristics of the articles published in Brazilian journals of accounting from 2000-2015 with respect to the topic of hidden costs. Hidden costs occur during an organization's management process, although they are not routinely perceived. They have their origin in internal or external dysfunctions of the organization and represent lapses and missed earnings. The nature of the study is quantitative and bibliometric. The sample was composed of 16 articles on the subject of hidden costs published in Brazilian accounting journals listed by the National Association of Graduate Programs in Accounting (ANPCONT during the period under analysis. Principal findings indicate that only 7 of the 37 journals analyzed published on the subject, for a total of 16 articles . This represents only 0.22% of all articles published in the journals analyzed. It is further noted that only 2 of the 16 articles were published in journals having a Qualis rating higher than B2. Forty-eight (48 different authors participated in the preparation of these studies, with only one author participating in more than one article. With respect to the specific issues addressed, environmental costs are noteworthy, present in 4 of the 16 articles analyzed. The contribution of this study is the identification of the lack of academic development on the subject, given the low number of articles published and the predominance of exploratory research (found in 7 of the studies analyzed.

  6. Stroke: a Hidden Danger of Margin Trading in Stock Markets.

    Science.gov (United States)

    Lin, Shu-Hui; Wang, Chien-Ho; Liu, Tsai-Ching; Chen, Chin-Shyan

    2015-10-01

    Using 10-year population data from 2000 through 2009 in Taiwan, this is the first paper to analyze the relationship between margin trading in stock markets and stroke hospitalizations. The results show that 3 and 6 days after an increase of margin trading in the Taiwan stock markets are associated with greater stoke hospitalizations. In general, a 1 % increase in total margin trading positions is associated with an increment of 2.5 in the total number of stroke hospitalizations, where the mean number of hospital admissions is 233 cases a day. We further examine the effects of margin trading by gender and age groups and find that the effects of margin trading are significant for males and those who are 45-74 years old only. In summary, buying stocks with money you do not have is quite risky, especially if the prices of those stocks fall past a certain level or if there is a sudden and severe drop in the stock market. There is also a hidden danger to one's health from margin trading. A person should be cautious before conducting margin trading, because while it can be quite profitable, danger always lurks just around the corner.

  7. Diurnal modulation signal from dissipative hidden sector dark matter

    Directory of Open Access Journals (Sweden)

    R. Foot

    2015-09-01

    Full Text Available We consider a simple generic dissipative dark matter model: a hidden sector featuring two dark matter particles charged under an unbroken U(1′ interaction. Previous work has shown that such a model has the potential to explain dark matter phenomena on both large and small scales. In this framework, the dark matter halo in spiral galaxies features nontrivial dynamics, with the halo energy loss due to dissipative interactions balanced by a heat source. Ordinary supernovae can potentially supply this heat provided kinetic mixing interaction exists with strength ϵ∼10−9. This type of kinetically mixed dark matter can be probed in direct detection experiments. Importantly, this self-interacting dark matter can be captured within the Earth and shield a dark matter detector from the halo wind, giving rise to a diurnal modulation effect. We estimate the size of this effect for detectors located in the Southern hemisphere, and find that the modulation is large (≳10% for a wide range of parameters.

  8. Eating disorders: a hidden phenomenon in outpatient mental health?

    Science.gov (United States)

    Fursland, Anthea; Watson, Hunna J

    2014-05-01

    Eating disorders are common but underdiagnosed illnesses. Help-seeking for co-occurring issues, such as anxiety and depression, are common. To identify the prevalence of eating problems, using the SCOFF, and eating disorders when screening positive on the SCOFF (i.e., ≥2), among patients seeking help for anxiety and depression at a community-based mental health service. Patients (N = 260) consecutively referred and assessed for anxiety and depression treatment were administered the SCOFF screening questionnaire and a semi-structured standardized diagnostic interview during routine intake. 18.5% (48/260) scored ≥2 on the SCOFF, indicating eating problems. Of these, 41% (19/48) met criteria for an eating disorder. Thus, overall, 7.3% (19/260) of the sample met criteria for a DSM-IV eating disorder. Those scoring ≥2 on the SCOFF were more likely to: be female (p = 0.001), younger (p = 0.003), and have a history of self-harm (p eating disorders are a hidden phenomenon in general outpatient mental health. By using a standardized diagnostic interview to establish diagnosis rather than self- or staff-report, the study builds on limited previous findings. The naturalistic study setting shows that screening for eating disorders can be easily built into routine intake practice, and successfully identifies treatment need. Copyright © 2013 Wiley Periodicals, Inc.

  9. Herbal Weight Loss Pill Overdose: Sibutramine Hidden in Pepper Pill

    Directory of Open Access Journals (Sweden)

    Gul Pamukcu Gunaydin

    2015-01-01

    Full Text Available Supposedly herbal weight loss pills are sold online and are widely used in the world. Some of these products are found to contain sibutramine by FDA and their sale is prohibited. We report a case of a female patient who presented to the emergency department after taking slimming pills. 17-year-old female patient presented to the emergency room with palpitations, dizziness, anxiety, and insomnia. She stated that she had taken 3 pills named La Jiao Shou Shen for slimming purposes during the day. Her vital signs revealed tachycardia. On her physical examination, she was restless, her oropharynx was dry, her pupils were mydriatic, and no other pathological findings were found. Sibutramine intoxication was suspected. She was given 5 mg IV diazepam for restlessness. After supportive therapy and observation in emergency department for 12 hours there were no complications and the patient was discharged home. Some herbal pills that are sold online for weight loss have sibutramine hidden as an active ingredient, and their sale is prohibited for this reason. For people who use herbal weight loss drugs, sibutramine excessive intake should be kept in mind at all times.

  10. Hidden Connectivity in Networks with Vulnerable Classes of Nodes

    Directory of Open Access Journals (Sweden)

    Sebastian M. Krause

    2016-10-01

    Full Text Available In many complex systems representable as networks, nodes can be separated into different classes. Often these classes can be linked to a mutually shared vulnerability. Shared vulnerabilities may be due to a shared eavesdropper or correlated failures. In this paper, we show the impact of shared vulnerabilities on robust connectivity and how the heterogeneity of node classes can be exploited to maintain functionality by utilizing multiple paths. Percolation is the field of statistical physics that is generally used to analyze connectivity in complex networks, but in its existing forms, it cannot treat the heterogeneity of multiple vulnerable classes. To analyze the connectivity under these constraints, we describe each class as a color and develop a “color-avoiding” percolation. We present an analytic theory for random networks and a numerical algorithm for all networks, with which we can determine which nodes are color-avoiding connected and whether the maximal set percolates in the system. We find that the interaction of topology and color distribution implies a rich critical behavior, with critical values and critical exponents depending both on the topology and on the color distribution. Applying our physics-based theory to the Internet, we show how color-avoiding percolation can be used as the basis for new topologically aware secure communication protocols. Beyond applications to cybersecurity, our framework reveals a new layer of hidden structure in a wide range of natural and technological systems.

  11. Analyzing Hidden Semantics in Social Bookmarking of Open Educational Resources

    Science.gov (United States)

    Minguillón, Julià

    Web 2.0 services such as social bookmarking allow users to manage and share the links they find interesting, adding their own tags for describing them. This is especially interesting in the field of open educational resources, as delicious is a simple way to bridge the institutional point of view (i.e. learning object repositories) with the individual one (i.e. personal collections), thus promoting the discovering and sharing of such resources by other users. In this paper we propose a methodology for analyzing such tags in order to discover hidden semantics (i.e. taxonomies and vocabularies) that can be used to improve descriptions of learning objects and make learning object repositories more visible and discoverable. We propose the use of a simple statistical analysis tool such as principal component analysis to discover which tags create clusters that can be semantically interpreted. We will compare the obtained results with a collection of resources related to open educational resources, in order to better understand the real needs of people searching for open educational resources.

  12. EARLY-TYPE GALAXIES WITH TIDAL DEBRIS AND THEIR SCALING RELATIONS IN THE SPITZER SURVEY OF STELLAR STRUCTURE IN GALAXIES (S4G)

    International Nuclear Information System (INIS)

    Kim, Taehyun; Sheth, Kartik; Muñoz-Mateos, Juan-Carlos; Hinz, Joannah L.; Zaritsky, Dennis; Lee, Myung Gyoon; Gadotti, Dimitri A.; Knapen, Johan H.; Schinnerer, Eva; Ho, Luis C.; Madore, Barry F.; Laurikainen, Eija; Salo, Heikki; Athanassoula, E.; Bosma, Albert; De Swardt, Bonita; Comerón, Sébastien; Regan, Michael W.; Menéndez-Delmestre, Karín; De Paz, Armando Gil

    2012-01-01

    Tidal debris around galaxies can yield important clues on their evolution. We have identified tidal debris in 11 early-type galaxies (T ≤ 0) from a sample of 65 early types drawn from the Spitzer Survey of Stellar Structure in Galaxies (S 4 G). The tidal debris includes features such as shells, ripples, and tidal tails. A variety of techniques, including two-dimensional decomposition of galactic structures, were used to quantify the residual tidal features. The tidal debris contributes ∼3%-10% to the total 3.6 μm luminosity of the host galaxy. Structural parameters of the galaxies were estimated using two-dimensional profile fitting. We investigate the locations of galaxies with tidal debris in the fundamental plane and Kormendy relation. We find that galaxies with tidal debris lie within the scatter of early-type galaxies without tidal features. Assuming that the tidal debris is indicative of recent gravitational interaction or merger, this suggests that these galaxies have either undergone minor merging events so that the overall structural properties of the galaxies are not significantly altered, or they have undergone a major merging events but already have experienced sufficient relaxation and phase mixing so that their structural properties become similar to those of the non-interacting early-type galaxies.

  13. The First Simultaneous Microlensing Observations by Two Space Telescopes: Spitzer and Swift Reveal a Brown Dwarf in Event OGLE-2015-BLG-1319

    Science.gov (United States)

    Shvartzvald, Y.; Li, Z.; Udalski, A.; Gould, A.; Sumi, T.; Street, R. A.; Calchi Novati, S.; Hundertmark, M.; Bozza, V.; Beichman, C.; hide

    2016-01-01

    Simultaneous observations of microlensing events from multiple locations allow for the breaking of degeneracies between the physical properties of the lensing system, specifically by exploring different regions of the lens plane and by directly measuring the "microlens parallax". We report the discovery of a 30-65M J brown dwarf orbiting a K dwarf in the microlensing event OGLE-2015-BLG-1319. The system is located at a distance of approximately 5 kpc toward the Galactic Bulge. The event was observed by several ground-based groups as well as by Spitzer and Swift, allowing a measurement of the physical properties. However, the event is still subject to an eight-fold degeneracy, in particular the well-known close-wide degeneracy, and thus the projected separation between the two lens components is either approximately 0.25 au or approximately 45 au. This is the first microlensing event observed by Swift, with the UVOT camera. We study the region of microlensing parameter space to which Swift is sensitive, finding that though Swift could not measure the microlens parallax with respect to ground-based observations for this event, it can be important for other events. Specifically, it is important for detecting nearby brown dwarfs and free-floating planets in high magnification events.

  14. The Spitzer survey of interstellar clouds in the gould belt. VI. The Auriga-California molecular cloud observed with IRAC and MIPS

    Energy Technology Data Exchange (ETDEWEB)

    Broekhoven-Fiene, Hannah; Matthews, Brenda C. [Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8W 3P6 (Canada); Harvey, Paul M. [Astronomy Department, University of Texas at Austin, 1 University Station C1400, Austin, TX 78712-0259 (United States); Gutermuth, Robert A. [Department of Astronomy, University of Massachusetts, Amherst, MA (United States); Huard, Tracy L.; Miller, Jennifer F. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Tothill, Nicholas F. H. [School of Computing, Engineering and Mathematics, University of Western Sydney, Locked Bag 1797, Penrith, NSW 2751 (Australia); Nutter, David [School of Physics and Astronomy, Cardiff University, Queen' s Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Bourke, Tyler L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); DiFrancesco, James [National Research Council Herzberg Astronomy and Astrophysics, Victoria, BC, V9E 2E7 (Canada); Jørgensen, Jes K. [Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-DK-2100 Copenhagen Ø. (Denmark); Allen, Lori E. [National Optical Astronomy Observatories, Tucson, AZ (United States); Chapman, Nicholas L. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Dunham, Michael M. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States); Merín, Bruno [Herschel Science Centre, ESAC-ESA, P.O. Box 78, E-28691 Villanueva de la Cañada, Madrid (Spain); Terebey, Susan [Department of Physics and Astronomy PS315, 5151 State University Drive, California State University at Los Angeles, Los Angeles, CA 90032 (United States); Peterson, Dawn E. [Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States); and others

    2014-05-01

    We present observations of the Auriga-California Molecular Cloud (AMC) at 3.6, 4.5, 5.8, 8.0, 24, 70, and 160 μm observed with the IRAC and MIPS detectors as part of the Spitzer Gould Belt Legacy Survey. The total mapped areas are 2.5 deg{sup 2} with IRAC and 10.47 deg{sup 2} with MIPS. This giant molecular cloud is one of two in the nearby Gould Belt of star-forming regions, the other being the Orion A Molecular Cloud (OMC). We compare source counts, colors, and magnitudes in our observed region to a subset of the SWIRE data that was processed through our pipeline. Using color-magnitude and color-color diagrams, we find evidence for a substantial population of 166 young stellar objects (YSOs) in the cloud, many of which were previously unknown. Most of this population is concentrated around the LkHα 101 cluster and the filament extending from it. We present a quantitative description of the degree of clustering and discuss the relative fraction of YSOs in earlier (Class I and F) and later (Class II) classes compared to other clouds. We perform simple SED modeling of the YSOs with disks to compare the mid-IR properties to disks in other clouds and identify 14 classical transition disk candidates. Although the AMC is similar in mass, size, and distance to the OMC, it is forming about 15-20 times fewer stars.

  15. The Spitzer Survey of Interstellar Clouds in the Gould Belt. VI. The Auriga-California Molecular Cloud Observed with IRAC and MIPS

    Science.gov (United States)

    Broekhoven-Fiene, Hannah; Matthews, Brenda C.; Harvey, Paul M.; Gutermuth, Robert A.; Huard, Tracy L.; Tothill, Nicholas F. H.; Nutter, David; Bourke, Tyler L.; DiFrancesco, James; Jorgensen, Jes K.; hide

    2014-01-01

    We present observations of the Auriga-California Molecular Cloud (AMC) at 3.6, 4.5, 5.8, 8.0, 24, 70 and 160 micrometers observed with the IRAC and MIPS detectors as part of the Spitzer Gould Belt Legacy Survey. The total mapped areas are 2.5 deg(exp 2) with IRAC and 10.47 deg2 with MIPS. This giant molecular cloud is one of two in the nearby Gould Belt of star-forming regions, the other being the Orion A Molecular Cloud (OMC). We compare source counts, colors and magnitudes in our observed region to a subset of the SWIRE data that was processed through our pipeline. Using color-magnitude and color-color diagrams, we find evidence for a substantial population of 166 young stellar objects (YSOs) in the cloud, many of which were previously unknown. Most of this population is concentrated around the LkH(alpha) 101 cluster and the filament extending from it. We present a quantitative description of the degree of clustering and discuss the fraction of YSOs in the region with disks relative to an estimate of the diskless YSO population. Although the AMC is similar in mass, size and distance to the OMC, it is forming about 15 - 20 times fewer stars.

  16. THE UNUSUAL VERTICAL MASS DISTRIBUTION OF NGC 4013 SEEN THROUGH THE SPITZER SURVEY OF STELLAR STRUCTURE IN GALAXIES (S4G)

    International Nuclear Information System (INIS)

    Comeron, Sebastien; Elmegreen, Bruce G.; Knapen, Johan H.; Sheth, Kartik; Munoz-Mateos, Juan-Carlos; Kim, Taehyun; Mizusawa, Trisha; Hinz, Joannah L.; Regan, Michael W.; Gil de Paz, Armando; Menendez-Delmestre, KarIn; Seibert, Mark; Ho, Luis C.; Laurikainen, Eija; Salo, Heikki; Laine, Jarkko; Athanassoula, E.; Bosma, Albert; Buta, Ronald J.; Gadotti, Dimitri A.

    2011-01-01

    NGC 4013 is a nearby Sb edge-on galaxy known for its 'prodigious' H I warp and its 'giant' tidal stream. Previous work on this unusual object shows that it cannot be fitted satisfactorily by a canonical thin+thick disk structure. We have produced a new decomposition of NGC 4013, considering three stellar flattened components (thin+thick disk plus an extra and more extended component) and one gaseous disk. All four components are considered to be gravitationally coupled and isothermal. To do so, we have used the 3.6 μm images from the Spitzer Survey of Stellar Structure in Galaxies. We find evidence for NGC 4013 indeed having a thin and a thick disk and an extra flattened component. This smooth and extended component (scale height z EC ∼ 3 kpc) could be interpreted as a thick disk or as a squashed ellipsoidal halo and contains ∼20% of the total mass of all three stellar components. We argue it is unlikely to be related to the ongoing merger or due to the off-plane stars from a warp in the other two disk components. Instead, we favor a scenario in which the thick disk and the extended component were formed in a two-stage process, in which an initially thick disk has been dynamically heated by a merger soon enough in the galaxy history to have a new thick disk formed within it.

  17. MODELS OF THE η CORVI DEBRIS DISK FROM THE KECK INTERFEROMETER, SPITZER, AND HERSCHEL

    Energy Technology Data Exchange (ETDEWEB)

    Lebreton, J.; Beichman, C.; Millan-Gabet, R. [Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Bryden, G.; Mennesson, B. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., Pasadena, CA 91107 (United States); Defrère, D. [Department of Astronomy, University of Arizona, 993 N. Cherry Avenue, Tucson, AZ, 85721 (United States); Boccaletti, A., E-mail: lebretoj@gmail.com [LESIA, Observatoire de Paris, CNRS, University Pierre et Marie Curie Paris 6 and University Denis Diderot Paris 7, 5 place Jules Janssen, F-92195 Meudon (France)

    2016-02-01

    Debris disks are signposts of analogs to small-body populations of the solar system, often, however, with much higher masses and dust production rates. The disk associated with the nearby star η Crv is especially striking, as it shows strong mid- and far-infrared excesses despite an age of ∼1.4 Gyr. We undertake constructing a consistent model of the system that can explain a diverse collection of spatial and spectral data. We analyze Keck Interferometer Nuller measurements and revisit Spitzer and additional spectrophotometric data, as well as resolved Herschel images, to determine the dust spatial distribution in the inner exozodi and in the outer belt. We model in detail the two-component disk and the dust properties from the sub-AU scale to the outermost regions by fitting simultaneously all measurements against a large parameter space. The properties of the cold belt are consistent with a collisional cascade in a reservoir of ice-free planetesimals at 133 AU. It shows marginal evidence for asymmetries along the major axis. KIN enables us to establish that the warm dust consists of a ring that peaks between 0.2 and 0.8 AU. To reconcile this location with the ∼400 K dust temperature, very high albedo dust must be invoked, and a distribution of forsterite grains starting from micron sizes satisfies this criterion, while providing an excellent fit to the spectrum. We discuss additional constraints from the LBTI and near-infrared spectra, and we present predictions of what James Webb Space Telescope can unveil about this unusual object and whether it can detect unseen planets.

  18. DEEP JHKs AND SPITZER IMAGING OF FOUR ISOLATED MOLECULAR CLOUD CORES

    International Nuclear Information System (INIS)

    Chapman, Nicholas L.; Mundy, Lee G.

    2009-01-01

    We present observations in eight wavebands from 1.25 to 24 μm of four dense cores: L204C-2, L1152, L1155C-2, and L1228. Our goals are to study the young stellar object (YSO) population of these cores and to measure the mid-infrared extinction law. With our combined near-infrared and Spitzer photometry, we classify each source in the cores as, among other things, background stars, galaxies, or embedded YSOs. L1152 contains three YSOs and L1228 has seven, but neither L204C-2 nor L1155C-2 appear to contain any YSOs. We estimate an upper limit of 7 x 10 -5 to 5 x 10 -4 L sun for any undiscovered YSOs in our cores. We also compute the line-of-sight extinction law toward each background star. These measurements are averaged spatially, to create χ 2 maps of the changes in the mid-infrared extinction law throughout our cores, and also in different ranges of extinction. From the χ 2 maps, we identify two small regions in L1152 and L1228 where the outflows in those cores appear to be destroying the larger dust grains, thus altering the extinction law in those regions. On average, however, our extinction law is relatively flat from 3.6 to 24 μm for all ranges of extinction and in all four cores. From 3.6 to 8 μm, this law is consistent with a dust model that includes larger dust grains than the diffuse interstellar medium, which suggests grain growth has occurred in our cores. At 24 μm, our extinction law is two to four times higher than predicted by dust models. However, it is similar to other empirical measurements.

  19. THE LUMINOSITIES OF PROTOSTARS IN THE SPITZER c2d AND GOULD BELT LEGACY CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Dunham, Michael M.; Arce, Hector G. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States); Allen, Lori E. [National Optical Astronomy Observatories, Tucson, AZ (United States); Evans II, Neal J.; Harvey, Paul M. [Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States); Broekhoven-Fiene, Hannah; Matthews, Brenda C. [Herzberg Institute, National Research Council of Canada, 5071 W. Saanich Road, Victoria, BC V9E 2E7 (Canada); Chapman, Nicholas L. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), Department of Physics and Astronomy, 2145 Sheridan Road, Evanston, IL 60208 (United States); Cieza, Lucas A. [Institute for Astronomy, University of Hawaii at Manoa, Honolulu, HI 96822 (United States); Gutermuth, Robert A. [Department of Astronomy, University of Massachusetts, Amherst, MA (United States); Hatchell, Jennifer [Astrophysics Group, Physics, University of Exeter, Exeter EX4 4QL (United Kingdom); Huard, Tracy L.; Miller, Jennifer F. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Kirk, Jason M. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom); Merin, Bruno [Herschel Science Centre, ESAC-ESA, P.O. Box 78, E-28691 Villanueva de la Canada, Madrid (Spain); Peterson, Dawn E. [Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO 80301 (United States); Spezzi, Loredana, E-mail: michael.dunham@yale.edu [European Southern Observatory (ESO), Karl-Schwarzschild-Strasse 2, D-85748 Garching bei Muenchen (Germany)

    2013-04-15

    Motivated by the long-standing 'luminosity problem' in low-mass star formation whereby protostars are underluminous compared to theoretical expectations, we identify 230 protostars in 18 molecular clouds observed by two Spitzer Space Telescope Legacy surveys of nearby star-forming regions. We compile complete spectral energy distributions, calculate L{sub bol} for each source, and study the protostellar luminosity distribution. This distribution extends over three orders of magnitude, from 0.01 L{sub Sun} to 69 L{sub Sun }, and has a mean and median of 4.3 L{sub Sun} and 1.3 L{sub Sun }, respectively. The distributions are very similar for Class 0 and Class I sources except for an excess of low luminosity (L{sub bol} {approx}< 0.5 L{sub Sun }) Class I sources compared to Class 0. 100 out of the 230 protostars (43%) lack any available data in the far-infrared and submillimeter (70 {mu}m <{lambda} < 850 {mu}m) and have L{sub bol} underestimated by factors of 2.5 on average, and up to factors of 8-10 in extreme cases. Correcting these underestimates for each source individually once additional data becomes available will likely increase both the mean and median of the sample by 35%-40%. We discuss and compare our results to several recent theoretical studies of protostellar luminosities and show that our new results do not invalidate the conclusions of any of these studies. As these studies demonstrate that there is more than one plausible accretion scenario that can match observations, future attention is clearly needed. The better statistics provided by our increased data set should aid such future work.

  20. A new look at Spitzer primary transit observations of the exoplanet HD 189733b

    Energy Technology Data Exchange (ETDEWEB)

    Morello, G.; Waldmann, I. P.; Tinetti, G.; Howarth, I. D. [Department of Physics and Astronomy, University College London, Gower Street, WC1E6BT (United Kingdom); Peres, G. [Dipartimento di Fisica, Università degli Studi di Palermo, via Archirafi I-90123, Italy. (Italy); Micela, G., E-mail: giuseppe.morello.11@ucl.ac.uk [Dipartimento di Fisica e Chimica (previously Dipartimento di Fisica), Specola Universitaria, Università degli Studi di Palermo, Piazza del Parlamento 1 I-90123 (Italy)

    2014-05-01

    Blind source separation techniques are used to reanalyze two exoplanetary transit light curves of the exoplanet HD 189733b recorded with the IR camera IRAC on board the Spitzer Space Telescope at 3.6 μm during the 'cold' era. These observations, together with observations at other IR wavelengths, are crucial to characterize the atmosphere of the planet HD 189733b. Previous analyses of the same data sets reported discrepant results, hence the necessity of the reanalyses. The method we used here is based on the Independent Component Analysis (ICA) statistical technique, which ensures a high degree of objectivity. The use of ICA to detrend single photometric observations in a self-consistent way is novel in the literature. The advantage of our reanalyses over previous work is that we do not have to make any assumptions on the structure of the unknown instrumental systematics. Such 'admission of ignorance' may result in larger error bars than reported in the literature, up to a factor 1.6. This is a worthwhile tradeoff for much higher objectivity, necessary for trustworthy claims. Our main results are (1) improved and robust values of orbital and stellar parameters, (2) new measurements of the transit depths at 3.6 μm, (3) consistency between the parameters estimated from the two observations, (4) repeatability of the measurement within the photometric level of ∼2 × 10{sup –4} in the IR, and (5) no evidence of stellar variability at the same photometric level within one year.

  1. SEDS: THE SPITZER EXTENDED DEEP SURVEY. SURVEY DESIGN, PHOTOMETRY, AND DEEP IRAC SOURCE COUNTS

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, M. L. N.; Willner, S. P.; Fazio, G. G.; Huang, J.-S.; Hernquist, L.; Hora, J. L. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Arendt, R. [Observational Cosmology Laboratory, Code 665, Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Barmby, P. [University of Western Ontario, London, ON N6A 3K7 (Canada); Barro, G.; Faber, S.; Guhathakurta, P. [University of California Observatories/Lick Observatory and Department of Astronomy and Astrophysics University of California Santa Cruz, 1156 High St., Santa Cruz, CA 95064 (United States); Bell, E. F. [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States); Bouwens, R. [Leiden Observatory, Leiden University, NL-2300 RA Leiden (Netherlands); Cattaneo, A. [Aix Marseille Universite, CNRS, Laboratoire d' Astrophysique de Marseille, UMR 7326, F-13388, Marseille (France); Croton, D. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218 Hawthorn, VIC 3122 (Australia); Dave, R. [Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States); Dunlop, J. S. [Scottish Universities Physics Alliance, Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh, EH9 3HJ (United Kingdom); Egami, E. [Steward Observatory, University of Arizona, 933 N. Cherry Ave, Tucson, AZ 85721 (United States); Finlator, K. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, CK-2100 Copenhagen O (Denmark); Grogin, N. A., E-mail: mashby@cfa.harvard.edu [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); and others

    2013-05-20

    The Spitzer Extended Deep Survey (SEDS) is a very deep infrared survey within five well-known extragalactic science fields: the UKIDSS Ultra-Deep Survey, the Extended Chandra Deep Field South, COSMOS, the Hubble Deep Field North, and the Extended Groth Strip. SEDS covers a total area of 1.46 deg{sup 2} to a depth of 26 AB mag (3{sigma}) in both of the warm Infrared Array Camera (IRAC) bands at 3.6 and 4.5 {mu}m. Because of its uniform depth of coverage in so many widely-separated fields, SEDS is subject to roughly 25% smaller errors due to cosmic variance than a single-field survey of the same size. SEDS was designed to detect and characterize galaxies from intermediate to high redshifts (z = 2-7) with a built-in means of assessing the impact of cosmic variance on the individual fields. Because the full SEDS depth was accumulated in at least three separate visits to each field, typically with six-month intervals between visits, SEDS also furnishes an opportunity to assess the infrared variability of faint objects. This paper describes the SEDS survey design, processing, and publicly-available data products. Deep IRAC counts for the more than 300,000 galaxies detected by SEDS are consistent with models based on known galaxy populations. Discrete IRAC sources contribute 5.6 {+-} 1.0 and 4.4 {+-} 0.8 nW m{sup -2} sr{sup -1} at 3.6 and 4.5 {mu}m to the diffuse cosmic infrared background (CIB). IRAC sources cannot contribute more than half of the total CIB flux estimated from DIRBE data. Barring an unexpected error in the DIRBE flux estimates, half the CIB flux must therefore come from a diffuse component.

  2. Model-independent indirect detection constraints on hidden sector dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Elor, Gilly; Rodd, Nicholas L.; Slatyer, Tracy R.; Xue, Wei [Center for Theoretical Physics, Massachusetts Institute of Technology,77 Massachusetts Ave, Cambridge, MA 02139 (United States)

    2016-06-10

    If dark matter inhabits an expanded “hidden sector”, annihilations may proceed through sequential decays or multi-body final states. We map out the potential signals and current constraints on such a framework in indirect searches, using a model-independent setup based on multi-step hierarchical cascade decays. While remaining agnostic to the details of the hidden sector model, our framework captures the generic broadening of the spectrum of secondary particles (photons, neutrinos, e{sup +}e{sup −} and p-barp) relative to the case of direct annihilation to Standard Model particles. We explore how indirect constraints on dark matter annihilation limit the parameter space for such cascade/multi-particle decays. We investigate limits from the cosmic microwave background by Planck, the Fermi measurement of photons from the dwarf galaxies, and positron data from AMS-02. The presence of a hidden sector can change the constraints on the dark matter by up to an order of magnitude in either direction (although the effect can be much smaller). We find that generally the bound from the Fermi dwarfs is most constraining for annihilations to photon-rich final states, while AMS-02 is most constraining for electron and muon final states; however in certain instances the CMB bounds overtake both, due to their approximate independence on the details of the hidden sector cascade. We provide the full set of cascade spectra considered here as publicly available code with examples at http://web.mit.edu/lns/research/CascadeSpectra.html.

  3. A single hidden layer feedforward network with only one neuron in the hidden layer can approximate any univariate function

    OpenAIRE

    Guliyev, Namig; Ismailov, Vugar

    2016-01-01

    The possibility of approximating a continuous function on a compact subset of the real line by a feedforward single hidden layer neural network with a sigmoidal activation function has been studied in many papers. Such networks can approximate an arbitrary continuous function provided that an unlimited number of neurons in a hidden layer is permitted. In this paper, we consider constructive approximation on any finite interval of $\\mathbb{R}$ by neural networks with only one neuron in the hid...

  4. THE DIFFERENCES IN THE TORUS GEOMETRY BETWEEN HIDDEN AND NON-HIDDEN BROAD LINE ACTIVE GALACTIC NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, Kohei; Ueda, Yoshihiro [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Packham, Christopher; Lopez-Rodriguez, Enrique; Alsip, Crystal D. [Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States); Almeida, Cristina Ramos; Ramos, Andrés Asensio; González-Martín, Omaira [Instituto de Astrofísica de Canarias, C/Vía Láctea, s/n, E-38205 La Laguna, Tenerife (Spain); Alonso-Herrero, Almudena [Instituto de Física de Cantabria, CSIC-Universidad de Cantabria, E-39005 Santander (Spain); Díaz-Santos, Tanio [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Elitzur, Moshe [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506-0055 (United States); Hönig, Sebastian F. [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Imanishi, Masatoshi [Subaru Telescope, 650 North A’ohoku Place, Hilo, HI 96720 (United States); Levenson, Nancy A. [Gemini Observatory, Southern Operations Center, c/o AURA, Casilla 603, La Serena (Chile); Mason, Rachel E. [Gemini Observatory, Northern Operations Center, 670 N. A’ohoku Place, Hilo, HI 96720 (United States); Perlman, Eric S., E-mail: ichikawa@kusastro.kyoto-u.ac.jp [Department of Physics and Space Sciences, 150 W. University Blvd., Florida Institute of Technology, Melbourne, FL 32901 (United States)

    2015-04-20

    We present results from the fitting of infrared (IR) spectral energy distributions of 21 active galactic nuclei (AGNs) with clumpy torus models. We compiled high spatial resolution (∼0.3–0.7 arcsec) mid-IR (MIR) N-band spectroscopy, Q-band imaging, and nuclear near- and MIR photometry from the literature. Combining these nuclear near- and MIR observations, far-IR photometry, and clumpy torus models enables us to put constraints on the torus properties and geometry. We divide the sample into three types according to the broad line region (BLR) properties: type-1s, type-2s with scattered or hidden broad line region (HBLR) previously observed, and type-2s without any published HBLR signature (NHBLR). Comparing the torus model parameters gives us the first quantitative torus geometrical view for each subgroup. We find that NHBLR AGNs have smaller torus opening angles and larger covering factors than HBLR AGNs. This suggests that the chance to observe scattered (polarized) flux from the BLR in NHBLR could be reduced by the dual effects of (a) less scattering medium due to the reduced scattering volume given the small torus opening angle and (b) the increased torus obscuration between the observer and the scattering region. These effects give a reasonable explanation for the lack of observed HBLR in some type-2 AGNs.

  5. Hydrogeophysical investigations at Hidden Dam, Raymond, California

    Science.gov (United States)

    Minsley, Burke J.; Burton, Bethany L.; Ikard, Scott; Powers, Michael H.

    2011-01-01

    Self-potential and direct current resistivity surveys are carried out at the Hidden Dam site in Raymond, California to assess present-day seepage patterns and better understand the hydrogeologic mechanisms that likely influence seepage. Numerical modeling is utilized in conjunction with the geophysical measurements to predict variably-saturated flow through typical two-dimensional dam cross-sections as a function of reservoir elevation. Several different flow scenarios are investigated based on the known hydrogeology, as well as information about typical subsurface structures gained from the resistivity survey. The flow models are also used to simulate the bulk electrical resistivity in the subsurface under varying saturation conditions, as well as the self-potential response using petrophysical relationships and electrokinetic coupling equations.The self-potential survey consists of 512 measurements on the downstream area of the dam, and corroborates known seepage areas on the northwest side of the dam. Two direct-current resistivity profiles, each approximately 2,500 ft (762 m) long, indicate a broad sediment channel under the northwest side of the dam, which may be a significant seepage pathway through the foundation. A focusing of seepage in low-topography areas downstream of the dam is confirmed from the numerical flow simulations, which is also consistent with past observations. Little evidence of seepage is identified from the self-potential data on the southeast side of the dam, also consistent with historical records, though one possible area of focused seepage is identified near the outlet works. Integration of the geophysical surveys, numerical modeling, and observation well data provides a framework for better understanding seepage at the site through a combined hydrogeophysical approach.

  6. Foundational Forces & Hidden Variables in Technology Commercialization

    Science.gov (United States)

    Barnett, Brandon

    2011-03-01

    The science of physics seems vastly different from the process of technology commercialization. Physics strives to understand our world through the experimental deduction of immutable laws and dependent variables and the resulting macro-scale phenomenon. In comparison, the~goal of business is to make a profit by addressing the needs, preferences, and whims of individuals in a market. It may seem that this environment is too dynamic to identify all the hidden variables and deduct the foundational forces that impact a business's ability to commercialize innovative technologies. One example of a business ``force'' is found in the semiconductor industry. In 1965, Intel co-founder Gordon Moore predicted that the number of transistors incorporated in a chip will approximately double every 24 months. Known as Moore's Law, this prediction has become the guiding principle for the semiconductor industry for the last 40 years. Of course, Moore's Law is not really a law of nature; rather it is the result of efforts by Intel and the entire semiconductor industry. A closer examination suggests that there are foundational principles of business that underlie the macro-scale phenomenon of Moore's Law. Principles of profitability, incentive, and strategic alignment have resulted in a coordinated influx of resources that has driven technologies to market, increasing the profitability of the semiconductor industry and optimizing the fitness of its participants. New innovations in technology are subject to these same principles. So, in addition to traditional market forces, these often unrecognized forces and variables create challenges for new technology commercialization. In this talk, I will draw from ethnographic research, complex adaptive theory, and industry data to suggest a framework with which to think about new technology commercialization. Intel's bio-silicon initiative provides a case study.

  7. How to restore the fiduciary relationship. An interview with Eliot Spitzer. Interview by Louise O'Brien.

    Science.gov (United States)

    Spitzer, Eliot

    2004-05-01

    Eliot Spitzer's investigations into the mutual fund and investment-banking industries have made the New York State attorney general the de facto flag bearer of corporate reform. His exposure of conflicts of interest between investment bankers and research analyst in Wall Street firms led to the $1.4 billion global settlement between regulators and banking houses in 2003. In this interview, Spitzer describes the challenge of protecting public markets from conflicts of interest, paying particular attention to how such conflicts get institutionalized in an industry. "The cases that have gotten me and my fellow regulators most upset are the ones where we've seen senior management being tolerant of rank abuses," he says. "Because then you know that the entire structure is rotten." He also points the finger squarely at boards, maintaining that board members are drawn from pools of company and industry insiders. He cites "a void in values in a lot of boardrooms," holding up executive compensation as a powerful example. "Board compensation committees ... are self-selected and interwoven--it's a rigged marketplace." He continues, "It would be interesting to see what the world would look like if CEO pay packages had to be submitted to shareholder votes." Spitzer suggests that what's really needed is for all business leaders to reinstill throughout their organizations the critical notion of a fiduciary duty--whether it is to the shareholder or to the customer. Using the mutual fund industry as an example, he also contrasts the value of enforcement with that of regulation and articulates an important--and surprisingly limited--role for government in protecting free markets.

  8. The Demographics and Properties of Wide-Orbit, Planetary-Mass Companions from PSF Fitting of Spitzer/IRAC Images

    Science.gov (United States)

    Martinez, Raquel; Kraus, Adam L.

    2017-06-01

    Over the past decade, a growing population of planetary-mass companions ( 100 AU) from their host stars, challenging existing models of both star and planet formation. It is unclear whether these systems represent the low-mass extreme of stellar binary formation or the high-mass and wide-orbit extreme of planet formation theories, as various proposed formation pathways inadequately explain the physical and orbital aspects of these systems. Even so, determining which scenario best reproduces the observed characteristics of the PMCs will come once a statistically robust sample of directly-imaged PMCs are found and studied.We are developing an automated pipeline to search for wide-orbit PMCs to young stars in Spitzer/IRAC images. A Markov Chain Monte Carlo (MCMC) algorithm is the backbone of our novel point spread function (PSF) subtraction routine that efficiently creates and subtracts χ2-minimizing instrumental PSFs, simultaneously measuring astrometry and infrared photometry of these systems across the four IRAC channels (3.6 μm, 4.5 μm, 5.8 μm, and 8 μm). In this work, we present the results of a Spitzer/IRAC archival imaging study of 11 young, low-mass (0.044-0.88 M⊙ K3.5-M7.5) stars known to have faint, low-mass companions in 3 nearby star-forming regions (Chameleon, Taurus, and Upper Scorpius). We characterize the systems found to have low-mass companions with non-zero [I1] - [I4] colors, potentially signifying the presence of a circum(sub?)stellar disk. Plans for future pipeline improvements and paths forward will also be discussed. Once this computational foundation is optimized, the stage is set to quickly scour the nearby star-forming regions already imaged by Spitzer, identify potential candidates for further characterization with ground- or space-based telescopes, and increase the number of widely-separated PMCs known.

  9. Spitzer Observations of Comet 9P/Tempel 1 During Deep Impact : Water and Dust Production and Spatial Distribution

    Science.gov (United States)

    Gicquel, Adeline; Bockelée-Morvan, D.; Kelley, M. S.; Woodward, C. E.

    2009-09-01

    The Deep Impact (DI) spacecraft encountered comet 9P/Tempel 1 on July 4th, 2005 (rh = 1.506 AU). Spectral maps covering 20'' x 67'' (1.85''/pixel) were acquired with the IRS instrument on the Spitzer Space Telescope (ΔSpitzer = 0.72 AU) at different times around the Deep Impact event: twice before impact (TI-41.3hrs and TI-22.9hrs) and twelve times after impact (between TI+0.67hrs and TI+1027hrs). These IRS observations (Lisse et al 2006, Sciences 313, 635) were taken from the Spitzer data archive. We present the interpretation of 5.2-7.6 µm spectra obtained in the second order of the short-wavelength module (SL2). To reduce the contribution of artifacts in the spectra, 5x5 pixel extraction apertures (9.25''x9.25'') were used. On the first stage we studied the water ν2 vibrational band emission at 6.4µm, which is present in most spectra. The water production rate before impact is deduced ( 4.25e27 molecules/sec). In order to study both the amount and origin of the water molecules released after impact, we used extractions centered on the nucleus and along the length of the slit. We analyzed the spatial distribution of water and its time evolution with a time-dependent model which describes the evolution of the water cloud after impact. The underlying continuum in the spectra provides information on the evolution and color temperature of the dust ejecta. The dust mass and dust/gas ratio in the ejecta cloud are derived and compared with other values published in the literature.

  10. The Spitzer search for the transits of HARPS low-mass planets. II. Null results for 19 planets

    Science.gov (United States)

    Gillon, M.; Demory, B.-O.; Lovis, C.; Deming, D.; Ehrenreich, D.; Lo Curto, G.; Mayor, M.; Pepe, F.; Queloz, D.; Seager, S.; Ségransan, D.; Udry, S.

    2017-05-01

    Short-period super-Earths and Neptunes are now known to be very frequent around solar-type stars. Improving our understanding of these mysterious planets requires the detection of a significant sample of objects suitable for detailed characterization. Searching for the transits of the low-mass planets detected by Doppler surveys is a straightforward way to achieve this goal. Indeed, Doppler surveys target the most nearby main-sequence stars, they regularly detect close-in low-mass planets with significant transit probability, and their radial velocity data constrain strongly the ephemeris of possible transits. In this context, we initiated in 2010 an ambitious Spitzer multi-Cycle transit search project that targeted 25 low-mass planets detected by radial velocity, focusing mainly on the shortest-period planets detected by the HARPS spectrograph. We report here null results for 19 targets of the project. For 16 planets out of 19, a transiting configuration is strongly disfavored or firmly rejected by our data for most planetary compositions. We derive a posterior probability of 83% that none of the probed 19 planets transits (for a prior probability of 22%), which still leaves a significant probability of 17% that at least one of them does transit. Globally, our Spitzer project revealed or confirmed transits for three of its 25 targeted planets, and discarded or disfavored the transiting nature of 20 of them. Our light curves demonstrate for Warm Spitzer excellent photometric precisions: for 14 targets out of 19, we were able to reach standard deviations that were better than 50 ppm per 30 min intervals. Combined with its Earth-trailing orbit, which makes it capable of pointing any star in the sky and to monitor it continuously for days, this work confirms Spitzer as an optimal instrument to detect sub-mmag-deep transits on the bright nearby stars targeted by Doppler surveys. The photometric and radial velocity time series used in this work are only available at the

  11. A Multiple Hidden Layers Extreme Learning Machine Method and Its Application

    Directory of Open Access Journals (Sweden)

    Dong Xiao

    2017-01-01

    Full Text Available Extreme learning machine (ELM is a rapid learning algorithm of the single-hidden-layer feedforward neural network, which randomly initializes the weights between the input layer and the hidden layer and the bias of hidden layer neurons and finally uses the least-squares method to calculate the weights between the hidden layer and the output layer. This paper proposes a multiple hidden layers ELM (MELM for short which inherits the characteristics of parameters of the first hidden layer. The parameters of the remaining hidden layers are obtained by introducing a method (make the actual output zero error approach the expected hidden layer output. Based on the MELM algorithm, many experiments on regression and classification show that the MELM can achieve the satisfactory results based on average precision and good generalization performance compared to the two-hidden-layer ELM (TELM, the ELM, and some other multilayer ELM.

  12. Revealing the hidden faults in the SE flank of Mt. Etna using radon in-soil gas measurement.

    Science.gov (United States)

    Johnová, K; Thinová, L; Giammanco, S

    2014-07-01

    Although there are many methods for investigating tectonic structures, many faults remain hidden, and they can endanger the life and property of people living along them. The slopes of volcanoes are covered with such hidden faults, near which strong earthquakes and gas releases can appear. Revealing hidden faults can therefore contribute significantly to the protection of people living in volcanic areas. In the study, seven different techniques were used for making measurements of in-soil radon concentrations in order to search for hidden faults on the SE flank of the Mt. Etna volcano. These reported methods had previously been proved to be useful tools for investigating fault structures. The main aim of the experiment presented here was to evaluate the usability of these methods in the geological conditions of the Mt. Etna region, and to find the best place for continual radon monitoring using a permanent station in the near future. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. COSMIC INFRARED BACKGROUND FLUCTUATIONS IN DEEP SPITZER INFRARED ARRAY CAMERA IMAGES: DATA PROCESSING AND ANALYSIS

    International Nuclear Information System (INIS)

    Arendt, Richard G.; Kashlinsky, A.; Moseley, S. H.; Mather, J.

    2010-01-01

    This paper provides a detailed description of the data reduction and analysis procedures that have been employed in our previous studies of spatial fluctuation of the cosmic infrared background (CIB) using deep Spitzer Infrared Array Camera observations. The self-calibration we apply removes a strong instrumental signal from the fluctuations that would otherwise corrupt the results. The procedures and results for masking bright sources and modeling faint sources down to levels set by the instrumental noise are presented. Various tests are performed to demonstrate that the resulting power spectra of these fields are not dominated by instrumental or procedural effects. These tests indicate that the large-scale (∼>30') fluctuations that remain in the deepest fields are not directly related to the galaxies that are bright enough to be individually detected. We provide the parameterization of these power spectra in terms of separate instrument noise, shot noise, and power-law components. We discuss the relationship between fluctuations measured at different wavelengths and depths, and the relations between constraints on the mean intensity of the CIB and its fluctuation spectrum. Consistent with growing evidence that the ∼1-5 μm mean intensity of the CIB may not be as far above the integrated emission of resolved galaxies as has been reported in some analyses of DIRBE and IRTS observations, our measurements of spatial fluctuations of the CIB intensity indicate the mean emission from the objects producing the fluctuations is quite low (∼>1 nW m -2 sr -1 at 3-5 μm), and thus consistent with current γ-ray absorption constraints. The source of the fluctuations may be high-z Population III objects, or a more local component of very low luminosity objects with clustering properties that differ from the resolved galaxies. Finally, we discuss the prospects of the upcoming space-based surveys to directly measure the epochs inhabited by the populations producing these

  14. Cosmic Infrared Background Fluctuations in Deep Spitzer Infrared Array Camera Images: Data Processing and Analysis

    Science.gov (United States)

    Arendt, Richard G.; Kashlinsky, A.; Moseley, S. H.; Mather, J.

    2010-01-01

    This paper provides a detailed description of the data reduction and analysis procedures that have been employed in our previous studies of spatial fluctuation of the cosmic infrared background (CIB) using deep Spitzer Infrared Array Camera observations. The self-calibration we apply removes a strong instrumental signal from the fluctuations that would otherwise corrupt the results. The procedures and results for masking bright sources and modeling faint sources down to levels set by the instrumental noise are presented. Various tests are performed to demonstrate that the resulting power spectra of these fields are not dominated by instrumental or procedural effects. These tests indicate that the large-scale (gsim30') fluctuations that remain in the deepest fields are not directly related to the galaxies that are bright enough to be individually detected. We provide the parameterization of these power spectra in terms of separate instrument noise, shot noise, and power-law components. We discuss the relationship between fluctuations measured at different wavelengths and depths, and the relations between constraints on the mean intensity of the CIB and its fluctuation spectrum. Consistent with growing evidence that the ~1-5 μm mean intensity of the CIB may not be as far above the integrated emission of resolved galaxies as has been reported in some analyses of DIRBE and IRTS observations, our measurements of spatial fluctuations of the CIB intensity indicate the mean emission from the objects producing the fluctuations is quite low (gsim1 nW m-2 sr-1 at 3-5 μm), and thus consistent with current γ-ray absorption constraints. The source of the fluctuations may be high-z Population III objects, or a more local component of very low luminosity objects with clustering properties that differ from the resolved galaxies. Finally, we discuss the prospects of the upcoming space-based surveys to directly measure the epochs inhabited by the populations producing these source

  15. Theoretical analysis of hidden photon searches in high-precision experiments

    International Nuclear Information System (INIS)

    Beranek, Tobias

    2014-01-01

    -Williams approximation to calculate the signal cross section of the process, which is widely used to design such experimental setups, is investigated. In a next step, the reaction e(A,Z)→e(A,Z)l + l - is analyzed as signal and background process in order to describe existing data obtained by the A1 experiment at MAMI with the aim to give accurate predictions of exclusion limits for the γ' parameter space. Finally, the derived methods are used to find predictions for future experiments, e.g., at MESA or at JLAB, allowing for a comprehensive study of the discovery potential of the complementary experiments. In the last part, a feasibility study for probing the hidden photon model by rare kaon decays is performed. For this purpose, invisible as well as visible decays of the hidden photon are considered within different classes of models. This allows one to find bounds for the parameter space from existing data and to estimate the reach of future experiments.

  16. Hidden multiparticle excitation in a weakly interacting Bose-Einstein condensate

    Science.gov (United States)

    Watabe, Shohei

    2018-03-01

    We investigate multiparticle excitation effect on a collective density excitation as well as a single-particle excitation in a weakly interacting Bose-Einstein condensate (BEC). We find that although the weakly interacting BEC offers weak multiparticle excitation spectrum at low temperatures, this multiparticle excitation effect may not remain hidden, but emerges as bimodality in the density response function through the single-particle excitation. Identification of spectra in the BEC between the single-particle excitation and the density excitation is also assessed at nonzero temperatures, which has been known to be unique nature in the BEC at absolute zero temperature.

  17. Molecular analysis reveals hidden diversity in Zungaro (Siluriformes: Pimelodidade): a genus of giant South American catfish.

    Science.gov (United States)

    Pires, Antonio A; Ramirez, Jorge L; Galetti, Pedro M; Troy, Waldo P; Freitas, Patricia D

    2017-06-01

    The genus Zungaro contains some of the largest catfish in South America. Two valid species are currently recognized: Zungaro jahu, inhabiting the Paraná and Paraguay basins, and Zungaro zungaro, occurring in the Amazonas and Orinoco basins. Analysing Zungaro specimens from the Amazonas, Orinoco, Paraguay and Paraná basins, based on the sequencing of COI and D-loop, we found at least three MOTUs, indicating the existence of hidden diversity within this fish group. Considering the ecological and economic values of this fish, our results are surely welcomed for its conservation, disclosing new findings on its diversity and pointing out the necessity for a detailed taxonomic revision.

  18. Hidden Statistics Approach to Quantum Simulations

    Science.gov (United States)

    Zak, Michail

    2010-01-01

    Recent advances in quantum information theory have inspired an explosion of interest in new quantum algorithms for solving hard computational (quantum and non-quantum) problems. The basic principle of quantum computation is that the quantum properties can be used to represent structure data, and that quantum mechanisms can be devised and built to perform operations with this data. Three basic non-classical properties of quantum mechanics superposition, entanglement, and direct-product decomposability were main reasons for optimism about capabilities of quantum computers that promised simultaneous processing of large massifs of highly correlated data. Unfortunately, these advantages of quantum mechanics came with a high price. One major problem is keeping the components of the computer in a coherent state, as the slightest interaction with the external world would cause the system to decohere. That is why the hardware implementation of a quantum computer is still unsolved. The basic idea of this work is to create a new kind of dynamical system that would preserve the main three properties of quantum physics superposition, entanglement, and direct-product decomposability while allowing one to measure its state variables using classical methods. In other words, such a system would reinforce the advantages and minimize limitations of both quantum and classical aspects. Based upon a concept of hidden statistics, a new kind of dynamical system for simulation of Schroedinger equation is proposed. The system represents a modified Madelung version of Schroedinger equation. It preserves superposition, entanglement, and direct-product decomposability while allowing one to measure its state variables using classical methods. Such an optimal combination of characteristics is a perfect match for simulating quantum systems. The model includes a transitional component of quantum potential (that has been overlooked in previous treatment of the Madelung equation). The role of the

  19. SPITZER ULTRA FAINT SURVEY PROGRAM (SURFS UP). II. IRAC-DETECTED LYMAN-BREAK GALAXIES AT 6 ≲ z ≲ 10 BEHIND STRONG-LENSING CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Kuang-Han; Bradač, Maruša; Hoag, Austin; Cain, Benjamin; Lubin, L. M.; Knight, Robert I. [University of California Davis, 1 Shields Avenue, Davis, CA 95616 (United States); Lemaux, Brian C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Ryan, R. E. Jr.; Brammer, Gabriel B. [Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, F-13388 Marseille (France); Castellano, Marco; Amorin, Ricardo; Fontana, Adriano; Merlin, Emiliano [INAF—Osservatorio Astronomico di Roma Via Frascati 33, I-00040 Monte Porzio Catone (Italy); Schmidt, Kasper B. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Schrabback, Tim [Argelander-Institut für Astronomie, Auf Dem Hügel 71, D-53121 Bonn (Germany); Treu, Tommaso [Department of Physics and Astronomy, UCLA, Los Angeles, CA 90095 (United States); Gonzalez, Anthony H. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Linden, Anja von der, E-mail: khhuang@ucdavis.edu, E-mail: astrokuang@gmail.com [Department of Physics, Stanford University, 382 Via Pueblo Mall, Stanford, CA 94305 (United States)

    2016-01-20

    We study the stellar population properties of the IRAC-detected 6 ≲ z ≲ 10 galaxy candidates from the Spitzer UltRa Faint SUrvey Program. Using the Lyman Break selection technique, we find a total of 17 galaxy candidates at 6 ≲ z ≲ 10 from Hubble Space Telescope images (including the full-depth images from the Hubble Frontier Fields program for MACS 1149 and MACS 0717) that have detections at signal-to-noise ratios  ≥ 3 in at least one of the IRAC 3.6 and 4.5 μm channels. According to the best mass models available for the surveyed galaxy clusters, these IRAC-detected galaxy candidates are magnified by factors of ∼1.2–5.5. Due to the magnification of the foreground galaxy clusters, the rest-frame UV absolute magnitudes M{sub 1600} are between −21.2 and −18.9 mag, while their intrinsic stellar masses are between 2 × 10{sup 8}M{sub ⊙} and 2.9 × 10{sup 9}M{sub ⊙}. We identify two Lyα emitters in our sample from the Keck DEIMOS spectra, one at z{sub Lyα} = 6.76 (in RXJ 1347) and one at z{sub Lyα} = 6.32 (in MACS 0454). We find that 4 out of 17 z ≳ 6 galaxy candidates are favored by z ≲ 1 solutions when IRAC fluxes are included in photometric redshift fitting. We also show that IRAC [3.6]–[4.5] color, when combined with photometric redshift, can be used to identify galaxies which likely have strong nebular emission lines or obscured active galactic nucleus contributions within certain redshift windows.

  20. THE SPITZER SPACE TELESCOPE SURVEY OF THE ORION A AND B MOLECULAR CLOUDS. II. THE SPATIAL DISTRIBUTION AND DEMOGRAPHICS OF DUSTY YOUNG STELLAR OBJECTS

    International Nuclear Information System (INIS)

    Megeath, S. T.; Kryukova, E.; Gutermuth, R.; Muzerolle, J.; Hora, J. L.; Myers, P. C.; Fazio, G. G.; Allen, L. E.; Flaherty, K.; Hartmann, L.; Pipher, J. L.; Stauffer, J.; Young, E. T.

    2016-01-01

    We analyze the spatial distribution of dusty young stellar objects (YSOs) identified in the Spitzer Survey of the Orion Molecular clouds, augmenting these data with Chandra X-ray observations to correct for incompleteness in dense clustered regions. We also devise a scheme to correct for spatially varying incompleteness when X-ray data are not available. The local surface densities of the YSOs range from 1 pc −2 to over 10,000 pc −2 , with protostars tending to be in higher density regions. This range of densities is similar to other surveyed molecular clouds with clusters, but broader than clouds without clusters. By identifying clusters and groups as continuous regions with surface densities ≥10 pc −2 , we find that 59% of the YSOs are in the largest cluster, the Orion Nebula Cluster (ONC), while 13% of the YSOs are found in a distributed population. A lower fraction of protostars in the distributed population is evidence that it is somewhat older than the groups and clusters. An examination of the structural properties of the clusters and groups shows that the peak surface densities of the clusters increase approximately linearly with the number of members. Furthermore, all clusters with more than 70 members exhibit asymmetric and/or highly elongated structures. The ONC becomes azimuthally symmetric in the inner 0.1 pc, suggesting that the cluster is only ∼2 Myr in age. We find that the star formation efficiency (SFE) of the Orion B cloud is unusually low, and that the SFEs of individual groups and clusters are an order of magnitude higher than those of the clouds. Finally, we discuss the relationship between the young low mass stars in the Orion clouds and the Orion OB 1 association, and we determine upper limits to the fraction of disks that may be affected by UV radiation from OB stars or dynamical interactions in dense, clustered regions

  1. AN INFRARED CENSUS OF DUST IN NEARBY GALAXIES WITH SPITZER (DUSTiNGS). II. DISCOVERY OF METAL-POOR DUSTY AGB STARS

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Martha L.; Sonneborn, George [Observational Cosmology Lab, Code 665, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); McQuinn, Kristen B. W.; Gehrz, Robert D.; Skillman, Evan [Minnesota Institute for Astrophysics, School of Physics and Astronomy, 116 Church Street SE, University of Minnesota, Minneapolis, MN 55455 (United States); Barmby, Pauline [Department of Physics and Astronomy, University of Western Ontario, London, ON N6A 3K7 (Canada); Bonanos, Alceste Z. [IAASARS, National Observatory of Athens, GR-15236 Penteli (Greece); Gordon, Karl D.; Meixner, Margaret [STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Groenewegen, M. A. T. [Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussels (Belgium); Lagadec, Eric [Laboratoire Lagrange, UMR7293, Univ. Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d' Azur, F-06300 Nice (France); Lennon, Daniel [ESA-European Space Astronomy Centre, Apdo. de Correo 78, E-28691 Villanueva de la Cañada, Madrid (Spain); Marengo, Massimo [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); McDonald, Iain; Zijlstra, Albert [Jodrell Bank Centre for Astrophysics, Alan Turing Building, University of Manchester, Manchester M13 9PL (United Kingdom); Sloan, G. C. [Astronomy Department, Cornell University, Ithaca, NY 14853-6801 (United States); Van Loon, Jacco Th., E-mail: martha.boyer@nasa.gov [Astrophysics Group, Lennard-Jones Laboratories, Keele University, Staffordshire ST5 5BG (United Kingdom)

    2015-02-10

    The DUSTiNGS survey (DUST in Nearby Galaxies with Spitzer) is a 3.6 and 4.5 μm imaging survey of 50 nearby dwarf galaxies designed to identify dust-producing asymptotic giant branch (AGB) stars and massive stars. Using two epochs, spaced approximately six months apart, we identify a total of 526 dusty variable AGB stars (sometimes called ''extreme'' or x-AGB stars; [3.6]-[4.5] > 0.1 mag). Of these, 111 are in galaxies with [Fe/H] < –1.5 and 12 are in galaxies with [Fe/H] < –2.0, making them the most metal-poor dust-producing AGB stars known. We compare these identifications to those in the literature and find that most are newly discovered large-amplitude variables, with the exception of ≈30 stars in NGC 185 and NGC 147, 1 star in IC 1613, and 1 star in Phoenix. The chemical abundances of the x-AGB variables are unknown, but the low metallicities suggest that they are more likely to be carbon-rich than oxygen-rich and comparisons with existing optical and near-IR photometry confirm that 70 of the x-AGB variables are confirmed or likely carbon stars. We see an increase in the pulsation amplitude with increased dust production, supporting previous studies suggesting that dust production and pulsation are linked. We find no strong evidence linking dust production with metallicity, indicating that dust can form in very metal-poor environments.

  2. OBSERVATIONAL 5-20 μm INTERSTELLAR EXTINCTION CURVES TOWARD STAR-FORMING REGIONS DERIVED FROM SPITZER IRS SPECTRA

    International Nuclear Information System (INIS)

    McClure, M.

    2009-01-01

    Using Spitzer Infrared Spectrograph observations of G0-M4 III stars behind dark clouds, I construct 5-20 μm empirical extinction curves for 0.3 ≤ A K V between ∼3 and 50. For A K K > 1, the curve exhibits lower contrast between the silicate and absorption continuum, develops ice absorption, and lies closer to the Weingartner and Draine R V = 5.5 Case B curve, a result which is consistent with that of Flaherty et al. and Chiar et al. Recently, work using Spitzer Infrared Array Camera data by Chapman et al. independently reaches a similar conclusion that the shape of the extinction curve changes as a function of increasing A K . By calculating the optical depths of the 9.7 μm silicate and 6.0, 6.8, and 15.2 μm ice features, I determine that a process involving ice is responsible for the changing shape of the extinction curve and speculate that this process is a coagulation of ice-mantled grains rather than ice-mantled grains alone.

  3. Revisiting the Phase Curves of WASP-43b: Confronting Re-analyzed Spitzer Data with Cloudy Atmospheres

    Science.gov (United States)

    Mendonça, João M.; Malik, Matej; Demory, Brice-Olivier; Heng, Kevin

    2018-04-01

    Recently acquired Hubble and Spitzer phase curves of the short-period hot Jupiter WASP-43b make it an ideal target for confronting theory with data. On the observational front, we re-analyze the 3.6 and 4.5 μm Spitzer phase curves and demonstrate that our improved analysis better removes residual red noise due to intra-pixel sensitivity, which leads to greater fluxes emanating from the nightside of WASP-43b, thus reducing the tension between theory and data. On the theoretical front, we construct cloud-free and cloudy atmospheres of WASP-43b using our Global Circulation Model (GCM), THOR, which solves the non-hydrostatic Euler equations (compared to GCMs that typically solve the hydrostatic primitive equations). The cloud-free atmosphere produces a reasonable fit to the dayside emission spectrum. The multi-phase emission spectra constrain the cloud deck to be confined to the nightside and have a finite cloud-top pressure. The multi-wavelength phase curves are naturally consistent with our cloudy atmospheres, except for the 4.5 μm phase curve, which requires the presence of enhanced carbon dioxide in the atmosphere of WASP-43b. Multi-phase emission spectra at higher spectral resolution, as may be obtained using the James Webb Space Telescope, and a reflected-light phase curve at visible wavelengths would further constrain the properties of clouds in WASP-43b.

  4. SPITZER AS A MICROLENS PARALLAX SATELLITE: MASS MEASUREMENT FOR THE OGLE-2014-BLG-0124L PLANET AND ITS HOST STAR

    Energy Technology Data Exchange (ETDEWEB)

    Udalski, A.; Skowron, J.; Kozłowski, S.; Poleski, R.; Pietrukowicz, P.; Pietrzyński, G.; Szymański, M. K.; Mróz, P.; Soszyński, I.; Ulaczyk, K.; Wyrzykowski, Ł. [Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa (Poland); Yee, J. C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Gould, A.; Zhu, W.; Pogge, R. W. [Department of Astronomy, Ohio State University, 140 W. 18th Ave., Columbus, OH 43210 (United States); Carey, S. [Spitzer Science Center, MS 220-6, California Institute of Technology, Pasadena, CA (United States); Han, C. [Department of Physics, Chungbuk National University, Cheongju 371-763 (Korea, Republic of); Calchi Novati, S. [NASA Exoplanet Science Institute, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States)

    2015-02-01

    We combine Spitzer and ground-based observations to measure the microlens parallax vector π{sub E}, and thus the mass and distance of OGLE-2014-BLG-0124L, making it the first microlensing planetary system with a space-based parallax measurement. The planet and star have masses of m ∼ 0.5 M {sub jup} and M ∼ 0.7 M {sub ☉} and are separated by a ∼ 3.1 AU in projection. The main source of uncertainty in all of these numbers (approximately 30%, 30%, and 20%) is the relatively poor measurement of the Einstein radius θ{sub E}, rather than uncertainty in π{sub E}, which is measured with 2.5% precision. This compares to 22% based on OGLE data alone, implying that the Spitzer data provide not only a substantial improvement in the precision of the π{sub E} measurement, but also the first independent test of a ground-based π{sub E} measurement.

  5. Spitzer IRS (8-30 micron) Spectra of Basaltic Asteroids 1459 Magnya and 956 Elisa: Mineralogy and Thermal Properties

    Science.gov (United States)

    Lim, Lucy F.; Emery, J. P.; Moskovitz, N. A.

    2009-01-01

    We report preliminary results from Spitzer IRS (Infrared Spectrograph) spectroscopy of 956 Elisa, 1459 Magnya, and other small basaltic asteroids with the Spitzer IRS. Program targets include members of the dynamical family of the unique large differentiated asteroid 4 Vesta ("Vestoids"), several outer-main-belt basaltic asteroids whose orbits exclude them from originating on 4 Vesta, and the basaltic near-Earth asteroid 4055 Magellan. The preliminary thermal model (STM) fit to the 5--35 micron spectrum of 956 Elisa gives a radius of 5.4 +/- 0.3 km and a subsolar- point temperature of 282.2 +/- 0.5 K. This temperature corresponds to eta approximately equals 1.06 +/- 0.02, which is substantially higher than the eta approximately equals 0.756 characteristic of large main-belt asteroids. Unlike 4 Vesta and other large asteroids, therefore, 956 Elisa has significant thermal inertia in its surface layer. The wavelength of the Christiansen feature (emissivity maximum near 9 micron), the positions and shapes of the narrow maxima (10 micron, 11 micron) within the broad 9--14 micron silicate band, and the 19--20 micron minimum are consistent with features found in the laboratory spectra of diogenites and of low-Ca pyroxenes of similar composition (Wo<5, En50-En75).

  6. Online mixted sampling: An application in hidden populations Muestreo mixto online: Una aplicación en poblaciones ocultas Online mixted sampling: An application in hidden populations

    Directory of Open Access Journals (Sweden)

    María Tatiana Gorjup

    2012-04-01

    inmigrante argentino y utilizando como fuentes de información los grupos virtuales.Purpose: The objective of the article is to explore the possibilities offered by new technologies and virtual social networks for the recruitment of sampling units in hidden populations and as a support of the use of mixed methods.Design/methodology: The objective was to identify Argentinean entrepreneurs who start their business in Spain. The observation unit has the characteristics of a hidden population: 1 high geographic dispersion which makes it difficult to localize them; 2 underestimation of the size of Argentinean residents in the official statistics; 3 Argentinean residents in illegal situation; and, 4 in some cases, the factors that led the emigration were negative, making them reluctant to answer. In this context, the researchers used (1 an online virtual sampling and, (2 the traditional snowball sampling. The online virtual sampling was carried out by using a social network (Facebook through which 52 virtual groups of ‘Argentinean living in Spain’ were identified. Subsequently, each member was contacted by an individual message which explained the aim of the research and invited them to participate in the study. Findings: Through the development of this study, it was possible to prove that the use of virtual groups in social networks led to detect observation units that are not registered officially (administrative register, census, etc.. This finding contributed to increase the scope and size of the sample, it favoured the design of the qualitative sample and the triangulation of the results. Therefore, it increased the validity of the hidden population.Originality/value: The article presents an experience of application of virtual sampling and mixed methods in the study of hidden populations. In particular, it analysed Argentinean immigrant entrepreneurs by using virtual groups as a source of information.Purpose: The objective of the article is to explore the possibilities

  7. Multivariate longitudinal data analysis with mixed effects hidden Markov models.

    Science.gov (United States)

    Raffa, Jesse D; Dubin, Joel A

    2015-09-01

    Multiple longitudinal responses are often collected as a means to capture relevant features of the true outcome of interest, which is often hidden and not directly measurable. We outline an approach which models these multivariate longitudinal responses as generated from a hidden disease process. We propose a class of models which uses a hidden Markov model with separate but correlated random effects between multiple longitudinal responses. This approach was motivated by a smoking cessation clinical trial, where a bivariate longitudinal response involving both a continuous and a binomial response was collected for each participant to monitor smoking behavior. A Bayesian method using Markov chain Monte Carlo is used. Comparison of separate univariate response models to the bivariate response models was undertaken. Our methods are demonstrated on the smoking cessation clinical trial dataset, and properties of our approach are examined through extensive simulation studies. © 2015, The International Biometric Society.

  8. Discovering Hidden Controlling Parameters using Data Analytics and Dimensional Analysis

    Science.gov (United States)

    Del Rosario, Zachary; Lee, Minyong; Iaccarino, Gianluca

    2017-11-01

    Dimensional Analysis is a powerful tool, one which takes a priori information and produces important simplifications. However, if this a priori information - the list of relevant parameters - is missing a relevant quantity, then the conclusions from Dimensional Analysis will be incorrect. In this work, we present novel conclusions in Dimensional Analysis, which provide a means to detect this failure mode of missing or hidden parameters. These results are based on a restated form of the Buckingham Pi theorem that reveals a ridge function structure underlying all dimensionless physical laws. We leverage this structure by constructing a hypothesis test based on sufficient dimension reduction, allowing for an experimental data-driven detection of hidden parameters. Both theory and examples will be presented, using classical turbulent pipe flow as the working example. Keywords: experimental techniques, dimensional analysis, lurking variables, hidden parameters, buckingham pi, data analysis. First author supported by the NSF GRFP under Grant Number DGE-114747.

  9. TeraHertz imaging of hidden paint layers on canvas.

    Science.gov (United States)

    Adam, Aurèle J L; Planken, Paul C M; Meloni, Sabrina; Dik, Joris

    2009-03-02

    We show terahertz reflection images of hidden paint layers in a painting on canvas and compare the results with X-ray Radiography and In-frared Reflectography. Our terahertz measurements show strong reflections from both the canvas/paint interface and from the raw umber/lead white interface, indicating sufficient refractive-index contrast. Our results show that X-rays cannot be used to image through the lead white pigment which effectively blocks the X-rays. Although Infrared Reflectography is capable of vaguely observing the hidden paint strokes from the canvas side, we show that only terahertz imaging is capable of providing information on the thickness of the hidden paint layers. Terahertz imaging is thus shown to be a powerful imaging method for art historians, conservators and conservation scientists.

  10. Gauge mediation scenario with hidden sector renormalization in MSSM

    International Nuclear Information System (INIS)

    Arai, Masato; Kawai, Shinsuke; Okada, Nobuchika

    2010-01-01

    We study the hidden sector effects on the mass renormalization of a simplest gauge-mediated supersymmetry breaking scenario. We point out that possible hidden sector contributions render the soft scalar masses smaller, resulting in drastically different sparticle mass spectrum at low energy. In particular, in the 5+5 minimal gauge-mediated supersymmetry breaking with high messenger scale (that is favored by the gravitino cold dark matter scenario), we show that a stau can be the next lightest superparticle for moderate values of hidden sector self-coupling. This provides a very simple theoretical model of long-lived charged next lightest superparticles, which imply distinctive signals in ongoing and upcoming collider experiments.

  11. Applications of hidden symmetries to black hole physics

    International Nuclear Information System (INIS)

    Frolov, Valeri

    2011-01-01

    This work is a brief review of applications of hidden symmetries to black hole physics. Symmetry is one of the most important concepts of the science. In physics and mathematics the symmetry allows one to simplify a problem, and often to make it solvable. According to the Noether theorem symmetries are responsible for conservation laws. Besides evident (explicit) spacetime symmetries, responsible for conservation of energy, momentum, and angular momentum of a system, there also exist what is called hidden symmetries, which are connected with higher order in momentum integrals of motion. A remarkable fact is that black holes in four and higher dimensions always possess a set ('tower') of explicit and hidden symmetries which make the equations of motion of particles and light completely integrable. The paper gives a general review of the recently obtained results. The main focus is on understanding why at all black holes have something (symmetry) to hide.

  12. Next generation sequencing reveals the hidden diversity of zooplankton assemblages.

    Directory of Open Access Journals (Sweden)

    Penelope K Lindeque

    Full Text Available BACKGROUND: Zooplankton play an important role in our oceans, in biogeochemical cycling and providing a food source for commercially important fish larvae. However, difficulties in correctly identifying zooplankton hinder our understanding of their roles in marine ecosystem functioning, and can prevent detection of long term changes in their community structure. The advent of massively parallel next generation sequencing technology allows DNA sequence data to be recovered directly from whole community samples. Here we assess the ability of such sequencing to quantify richness and diversity of a mixed zooplankton assemblage from a productive time series site in the Western English Channel. METHODOLOGY/PRINCIPLE FINDINGS: Plankton net hauls (200 µm were taken at the Western Channel Observatory station L4 in September 2010 and January 2011. These samples were analysed by microscopy and metagenetic analysis of the 18S nuclear small subunit ribosomal RNA gene using the 454 pyrosequencing platform. Following quality control a total of 419,041 sequences were obtained for all samples. The sequences clustered into 205 operational taxonomic units using a 97% similarity cut-off. Allocation of taxonomy by comparison with the National Centre for Biotechnology Information database identified 135 OTUs to species level, 11 to genus level and 1 to order, <2.5% of sequences were classified as unknowns. By comparison a skilled microscopic analyst was able to routinely enumerate only 58 taxonomic groups. CONCLUSIONS: Metagenetics reveals a previously hidden taxonomic richness, especially for Copepoda and hard-to-identify meroplankton such as Bivalvia, Gastropoda and Polychaeta. It also reveals rare species and parasites. We conclude that Next Generation Sequencing of 18S amplicons is a powerful tool for elucidating the true diversity and species richness of zooplankton communities. While this approach allows for broad diversity assessments of plankton it may

  13. Hidden power system inflexibilities imposed by traditional unit commitment formulations

    International Nuclear Information System (INIS)

    Morales-España, Germán; Ramírez-Elizondo, Laura; Hobbs, Benjamin F.

    2017-01-01

    Highlights: • Quality and accuracy of traditional-energy- and power-based UCs are evaluated. • Real-time performance evaluation simulating “perfect” stochastic UCs. • Ideal energy-based stochastic UC formulations impose hidden system inflexibilities. • A deterministic power-based UC may outperform an ideal energy-based stochastic UC. • Power-based UC overcomes flaws of energy-based UC: lower cost and wind curtailment. - Abstract: Approximations made in traditional day-ahead unit commitment model formulations can result in suboptimal or even infeasible schedules for slow-start units and inaccurate predictions of actual costs and wind curtailment. With increasing wind penetration, these errors will become economically more significant. Here, we consider inaccuracies from three approximations: the use of hourly intervals in which energy production from each generator is modeled as being constant; the disregarding of startup and shutdown energy trajectories; and optimization based on expected wind profiles. The results of unit commitment formulations with those assumptions are compared to models that: (1) use a piecewise-linear power profiles of generation, load and wind, instead of the traditional stepwise energy profiles; (2) consider startup/shutdown trajectories; and (3) include many possible wind trajectories in a stochastic framework. The day-ahead hourly schedules of slow-start generators are then evaluated against actual wind and load profiles using a model real-time dispatch and quick-start unit commitment with a 5 min time step. We find that each simplification usually causes expected generation costs to increase by several percentage points, and results in significant understatement of expected wind curtailment and, in some cases, load interruptions. The inclusion of startup and shutdown trajectories often yielded the largest improvements in schedule performance.

  14. Explore the Buffering Effects of Perceived Hidden Inflation on Survival of Mobile Phone Service Providers in Taiwan

    Directory of Open Access Journals (Sweden)

    Sheng-Wen Liu

    2017-04-01

    Full Text Available The purpose of this study is to examine the moderating role of perceived hidden inflation on the relationships between service quality, brand trust and brand loyalty. All data collected from the target population are analyzed through two-step structural equation modeling (SEM and moderated multiple regression (MMR to examine the hypotheses. 1,050 questionnaires are randomly distributed at 21 telecommunication service stores in Taiwan. Findings indicated that service quality has no direct impact on behavioral loyalty but it has a significant indirect impact on behavioral loyalty through brand trust or attitudinal loyalty. Moreover, findings identify perceived hidden inflation as the moderating role in the service quality–brand trust–brand loyalty chain. Besides the need for empirical confirmation of the hypotheses given, finally, there are several practical implications for service marketers and future research directions for scholars.

  15. Performance based analysis of hidden beams in reinforced concrete structures

    Directory of Open Access Journals (Sweden)

    Helou Samir H.

    2014-01-01

    Full Text Available Local and perhaps regional vernacular reinforced concrete building construction leans heavily against designing slabs with imbedded hidden beams for flooring systems in most structures including major edifices. The practice is distinctive in both framed and in shear wall structures. Hidden beams are favoured structural elements due to their many inherent features that characterize them; they save on floor height clearance; they also save on formwork, labour and material cost. Moreover, hidden beams form an acceptable aesthetic appearance that does not hinder efficient interior space partitioning. Such beams have the added advantage of clearing the way for horizontal electromechanical ductwork. However, seismic considerations, in all likelihood, are seldom seriously addressed. The mentioned structural system of shallow beams is adopted in ribbed slabs, waffle slabs and at times with solid slabs. Ribbed slabs and waffle slabs are more prone to hidden beam inclusion due to the added effective height of the concrete section. Due to the presence of a relatively high reinforcement ratio at the joints the sections at such location tend to become less ductile with unreliable contribution to spandrel force resistance. In the following study the structural influence of hidden beams within slabs is investigated. With the primary focus on a performance based analysis of such elements within a structure. This is investigated with due attention to shear wall contribution to the overall behaviour of such structures. Numerical results point in the direction that the function of hidden beams is not as adequate as desired. Therefore it is strongly believed that they are generally superfluous and maybe eliminated altogether. Conversely, shallow beams seem to render the overall seismic capacity of the structure unreliable. Since such an argument is rarely manifested within the linear analysis domain; a pushover analysis exercise is thus mandatory for behaviour

  16. Detect and exploit hidden structure in fatty acid signature data

    Science.gov (United States)

    Budge, Suzanne; Bromaghin, Jeffrey; Thiemann, Gregory

    2017-01-01

    Estimates of predator diet composition are essential to our understanding of their ecology. Although several methods of estimating diet are practiced, methods based on biomarkers have become increasingly common. Quantitative fatty acid signature analysis (QFASA) is a popular method that continues to be refined and extended. Quantitative fatty acid signature analysis is based on differences in the signatures of prey types, often species, which are recognized and designated by investigators. Similarly, predator signatures may be structured by known factors such as sex or age class, and the season or region of sample collection. The recognized structure in signature data inherently influences QFASA results in important and typically beneficial ways. However, predator and prey signatures may contain additional, hidden structure that investigators either choose not to incorporate into an analysis or of which they are unaware, being caused by unknown ecological mechanisms. Hidden structure also influences QFASA results, most often negatively. We developed a new method to explore signature data for hidden structure, called divisive magnetic clustering (DIMAC). Our DIMAC approach is based on the same distance measure used in diet estimation, closely linking methods of data exploration and parameter estimation, and it does not require data transformation or distributional assumptions, as do many multivariate ordination methods in common use. We investigated the potential benefits of the DIMAC method to detect and subsequently exploit hidden structure in signature data using two prey signature libraries with quite different characteristics. We found that the existence of hidden structure in prey signatures can increase the confusion between prey types and thereby reduce the accuracy and precision of QFASA diet estimates. Conversely, the detection and exploitation of hidden structure represent a potential opportunity to improve predator diet estimates and may lead to new

  17. The hidden costs of coastal hazards: Implications for risk assessment and mitigation

    Science.gov (United States)

    Kunreuther, H.; Platt, R.; Baruch, S.; Bernknopf, R.L.; Buckley, M.; Burkett, V.; Conrad, D.; Davidson, T.; Deutsch, K.; Geis, D.; Jannereth, M.; Knap, A.; Lane, H.; Ljung, G.; McCauley, M.; Mileti, D.; Miller, T.; Morrow, B.; Meyers, J.; Pielke, R.; Pratt, A.; Tripp, J.

    2000-01-01

    Society has limited hazard mitigation dollars to invest. Which actions will be most cost effective, considering the true range of impacts and costs incurred? In 1997, the H. John Heinz III Center for Science, Economics and the Environment began a two-year study with a panel of experts to help develop new strategies to identify and reduce the costs of weather-related hazards associated with rapidly increasing coastal development activities.The Hidden Costs of Coastal Hazards presents the panel's findings, offering the first in-depth study that considers the costs of coastal hazards to natural resources, social institutions, business, and the built environment. Using Hurricane Hugo, which struck South Carolina in 1989, as a case study, it provides for the first time information on the full range of economic costs caused by a major coastal hazard event. The book:describes and examines unreported, undocumented, and hidden costs such as losses due to business interruption, reduction in property values, interruption of social services, psychological trauma, damage to natural systems, and othersexamines the concepts of risk and vulnerability, and discusses conventional approaches to risk assessment and the emerging area of vulnerability assessmentrecommends a comprehensive framework for developing and implementing mitigation strategiesdocuments the human impact of Hurricane Hugo and provides insight from those who lived through it.The Hidden Costs of Coastal Hazards takes a structured approach to the problem of coastal hazards, offering a new framework for community-based hazard mitigation along with specific recommendations for implementation. Decisionmakers -- both policymakers and planners -- who are interested in coastal hazard issues will find the book a unique source of new information and insight, as will private-sector decisionmakers including lenders, investors, developers, and insurers of coastal property.

  18. Engineering of Algorithms for Hidden Markov models and Tree Distances

    DEFF Research Database (Denmark)

    Sand, Andreas

    speed up all the classical algorithms for analyses and training of hidden Markov models. And I show how two particularly important algorithms, the forward algorithm and the Viterbi algorithm, can be accelerated through a reformulation of the algorithms and a somewhat more complicated parallelization....... Lastly, I show how hidden Markov models can be trained orders of magnitude faster on a given input by rethinking the forward algorithm such that it can automatically adapt itself to the input. Together, these optimization have enabled us to perform analysis of full genomes in a few minutes and thereby...

  19. Application of Hidden Markov Models in Biomolecular Simulations.

    Science.gov (United States)

    Shukla, Saurabh; Shamsi, Zahra; Moffett, Alexander S; Selvam, Balaji; Shukla, Diwakar

    2017-01-01

    Hidden Markov models (HMMs) provide a framework to analyze large trajectories of biomolecular simulation datasets. HMMs decompose the conformational space of a biological molecule into finite number of states that interconvert among each other with certain rates. HMMs simplify long timescale trajectories for human comprehension, and allow comparison of simulations with experimental data. In this chapter, we provide an overview of building HMMs for analyzing bimolecular simulation datasets. We demonstrate the procedure for building a Hidden Markov model for Met-enkephalin peptide simulation dataset and compare the timescales of the process.

  20. Image Coding using Markov Models with Hidden States

    DEFF Research Database (Denmark)

    Forchhammer, Søren Otto

    1999-01-01

    The Cylinder Partially Hidden Markov Model (CPH-MM) is applied to lossless coding of bi-level images. The original CPH-MM is relaxed for the purpose of coding by not imposing stationarity, but otherwise the model description is the same.......The Cylinder Partially Hidden Markov Model (CPH-MM) is applied to lossless coding of bi-level images. The original CPH-MM is relaxed for the purpose of coding by not imposing stationarity, but otherwise the model description is the same....

  1. Detecting Faults By Use Of Hidden Markov Models

    Science.gov (United States)

    Smyth, Padhraic J.

    1995-01-01

    Frequency of false alarms reduced. Faults in complicated dynamic system (e.g., antenna-aiming system, telecommunication network, or human heart) detected automatically by method of automated, continuous monitoring. Obtains time-series data by sampling multiple sensor outputs at discrete intervals of t and processes data via algorithm determining whether system in normal or faulty state. Algorithm implements, among other things, hidden first-order temporal Markov model of states of system. Mathematical model of dynamics of system not needed. Present method is "prior" method mentioned in "Improved Hidden-Markov-Model Method of Detecting Faults" (NPO-18982).

  2. Solvable models and hidden symmetries in QCD

    International Nuclear Information System (INIS)

    Yepez-Martinez, Tochtli; Hess, P. O.; Szczepaniak, A.; Civitarese, O.; Lerma H., S.

    2010-01-01

    We show that QCD Hamiltonians at low energy exhibit an SU(2) structure, when only few orbital levels are considered. In case many orbital levels are taken into account we also find a semi-analytic solution for the energy levels of the dominant part of the QCD Hamiltonian. The findings are important to propose the structure of phenomenological models.

  3. Mineralogy and Thermal Properties of V-Type Asteroid 956 Elisa: Evidence for Diogenitic Material from the Spitzer IRS (5-35 Micrometers) Spectrum

    Science.gov (United States)

    Lim, Lucy F.; Emery, Joshua P.; Moskovitz, Nicholas A.

    2010-01-01

    We present the thermal infrared (5-35 micrometer) spectrum of 956 Elisa as measured by the Spitzer Infrared Spectrograph ("IRS"; Houck,1.R. et .11. [20041. Astrophys, 1. SuppL 154, 18-24) together with new ground-based lightcurve data and near-IR spectra. From the visible lightcurve photometry, we determine a rotation period of 16.494 +/- 0.001 h, identify the rotational phase of the Spitzer observations, and estimate the visible absolute magnitude (Hv) at that rotational phase to be 12.58 +/- 0.04. From radiometric analysis of the thermal flux spectrum, we find that at the time of observation 956 Elisa had a projected radius of 5.3 +/- 0.4 km with a visible albedo pv = 0.142+/- 0.022, significantly lower than that of the prototype V-type asteroid, 4 Vesta. (This corresponds to a radius of 5.2 +/- 0.4 km at lightcurve mean.) Analysis with the standard thermal model (STM) results in a sub-solar temperature of 292.3 +/- 2.8 K and beaming parameter eta = 1.16 +/- 0.05. Thermophysical modeling places a lower limit of 20 J m(exp -2)K(exp -1)s(exp -1/2) on the thermal inertia of the asteroid's surface layer (if the surface is very smooth) but more likely values fall between 30 and 150 J m(exp -2)K(exp -1)s(exp -1/2) depending on the sense of rotation. The emissivity spectrum, calculated by dividing the measured thermal flux spectrum by the modeled thermal continuum, exhibits mineralogically interpretable spectral features within the 9-12 micrometer reststrahlen band, the 15-16.5 micrometer Si-O-Si stretching region, and the 16-25 micrometer reststrahlen region that are consistent with pyroxene of diogenitic composition: extant diogenitic pyroxenes fall within the narrow compositional range W0(sub 2+/-1)En(sub 74+/-2)Fs(sub 24+/-1). Spectral deconvolution of the 9-12 micrometer reststrahlen features indicates that up to approximately 20% olivine may also be present, suggesting an olivine-diogenite-like mineralogy. The mid-IR spectrum is inconsistent with non

  4. Photoacoustic imaging of hidden dental caries by using a fiber-based probing system

    Science.gov (United States)

    Koyama, Takuya; Kakino, Satoko; Matsuura, Yuji

    2017-04-01

    Photoacoustic method to detect hidden dental caries is proposed. It was found that high frequency ultrasonic waves are generated from hidden carious part when radiating laser light to occlusal surface of model tooth. By making a map of intensity of these high frequency components, photoacoustic images of hidden caries were successfully obtained. A photoacoustic imaging system using a bundle of hollow optical fiber was fabricated for using clinical application, and clear photoacoustic image of hidden caries was also obtained by this system.

  5. Hemolysis, hemorrhage, headache, and hidden abortion: imaging findings in antiphospholipid syndrome

    International Nuclear Information System (INIS)

    Mahnken, A.H.; Brandenburg, V.M.; Haage, P.; Guenther, R.W.; Frank, R.D.

    2003-01-01

    Antiphospholipid antibodies are associated with arterial and venous thromboses, recurrent pregnancy loss, and organ infarction. Any vascular region can be affected. We present a 20-year-old woman suffering from secondary antiphospholipid syndrome with a unique combination of multifocal venous thromboses, pulmonary embolism, spontaneous abortion, and splenic infarction. Diversity of clinical symptoms and diagnostic imaging modalities are discussed with emphasis on cross-sectional imaging. The syndrome should be suspected in patients with thromboses and organ infarctions of otherwise undetermined etiology. (orig.)

  6. Hemolysis, hemorrhage, headache, and hidden abortion: imaging findings in antiphospholipid syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Mahnken, A.H.; Brandenburg, V.M.; Haage, P.; Guenther, R.W. [Dept. of Diagnostic Radiology, Univ. Hospital, Univ. of Technology, Aachen (Germany); Frank, R.D. [Dept. of Nephrology and Immunology, Univ. of Technology, Aachen (Germany)

    2003-12-01

    Antiphospholipid antibodies are associated with arterial and venous thromboses, recurrent pregnancy loss, and organ infarction. Any vascular region can be affected. We present a 20-year-old woman suffering from secondary antiphospholipid syndrome with a unique combination of multifocal venous thromboses, pulmonary embolism, spontaneous abortion, and splenic infarction. Diversity of clinical symptoms and diagnostic imaging modalities are discussed with emphasis on cross-sectional imaging. The syndrome should be suspected in patients with thromboses and organ infarctions of otherwise undetermined etiology. (orig.)

  7. Finding Hidden Chemistry in Ancient Egyptian Artifacts: Pigment Degradation Taught in a Chemical Engineering Course

    Science.gov (United States)

    Gime´nez, Javier

    2015-01-01

    The main objective of this work was to show the application of the study of ancient technology and science on teaching (and learning) chemistry in Chemical Engineering Undergraduate studies. Degradation patterns of pigments used in Ancient Egypt were incorporated in the syllabus of the course entitled "Technological and Scientific…

  8. Hidden diversity in Senegalese bats and associated findings in the systematics of the family Vespertilionidae

    Czech Academy of Sciences Publication Activity Database

    Koubínová, D.; Irwin, N.; Hulva, P.; Koubek, Petr; Zima, Jan

    2013-01-01

    Roč. 10, č. 48 (2013), s. 48 ISSN 1742-9994 R&D Projects: GA AV ČR IAA6093404 Institutional support: RVO:68081766 Keywords : Vespertilionidae * Systematics * Phylogenetics * DNA * Karyotypes * Western Africa Subject RIV: EG - Zoology Impact factor: 2.304, year: 2013 http://www.frontiersinzoology.com/content/10/1/48

  9. Combining Spitzer Parallax and Keck II Adaptive Optics Imaging to Measure the Mass of a Solar-like Star Orbited by a Cold Gaseous Planet Discovered by Microlensing

    Science.gov (United States)

    Beaulieu, J.-P.; Batista, V.; Bennett, D. P.; Marquette, J.-B.; Blackman, J. W.; Cole, A. A.; Coutures, C.; Danielski, C.; Dominis Prester, D.; Donatowicz, J.; Fukui, A.; Koshimoto, N.; Lončarić, K.; Morales, J. C.; Sumi, T.; Suzuki, D.; Henderson, C.; Shvartzvald, Y.; Beichman, C.

    2018-02-01

    To obtain accurate mass measurements for cold planets discovered by microlensing, it is usually necessary to combine light curve modeling with at least two lens mass–distance relations. The physical parameters of the planetary system OGLE-2014-BLG-0124L have been constrained thanks to accurate parallax effect between ground-based and simultaneous space-based Spitzer observations. Here, we resolved the source+lens star from sub-arcsecond blends in H-band using adaptive optics (AO) observations with NIRC2 mounted on Keck II telescope. We identify additional flux, coincident with the source to within 160 mas. We estimate the potential contributions to this blended light (chance-aligned star, additional companion to the lens or to the source) and find that 85% of the NIR flux is due to the lens star at H L = 16.63 ± 0.06 and K L = 16.44 ± 0.06. We combined the parallax constraint and the AO constraint to derive the physical parameters of the system. The lensing system is composed of a mid-late type G main sequence star of M L = 0.9 ± 0.05 M ⊙ located at D L = 3.5 ± 0.2 kpc in the Galactic disk. Taking the mass ratio and projected separation from the original study leads to a planet of M p = 0.65 ± 0.044 M Jupiter at 3.48 ± 0.22 au. Excellent parallax measurements from simultaneous ground-space observations have been obtained on the microlensing event OGLE-2014-BLG-0124, but it is only when they are combined with ∼30 minutes of Keck II AO observations that the physical parameters of the host star are well measured.

  10. SPITZER OBSERVATIONS OF GJ 3470 b: A VERY LOW-DENSITY NEPTUNE-SIZE PLANET ORBITING A METAL-RICH M DWARF

    Energy Technology Data Exchange (ETDEWEB)

    Demory, Brice-Olivier; Seager, Sara [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139 (United States); Torres, Guillermo [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Neves, Vasco; Santos, Nuno [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Rogers, Leslie [Department of Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Gillon, Michaeel [Institut d' Astrophysique et de Geophysique, Universite de Liege, Allee du 6 Aout, 17, Bat. B5C, Liege 1 (Belgium); Horch, Elliott [Department of Physics, 501 Crescent Street, Southern Connecticut State University, New Haven, CT 06515 (United States); Sullivan, Peter [Department of Physics and Kavli Institute for Astrophysics and Space Research, MIT, 77 Massachusetts Avenue, Cambridge, MA 02138 (United States); Bonfils, Xavier; Delfosse, Xavier; Forveille, Thierry [UJF-Grenoble 1/CNRS-INSU, Institut de Planetologie et d' Astrophysique de Grenoble (IPAG) UMR 5274, Grenoble, F-38041 (France); Lovis, Christophe; Mayor, Michel; Udry, Stephane [Observatoire de Geneve, Universite de Geneve, 51 ch. des Maillettes, CH-1290 Versoix (Switzerland); Smalley, Barry, E-mail: demory@mit.edu [Astrophysics Group, Keele University, Staffordshire, ST55BG (United Kingdom)

    2013-05-10

    We present Spitzer/IRAC 4.5 {mu}m transit photometry of GJ 3470 b, a Neptune-size planet orbiting an M1.5 dwarf star with a 3.3 day period recently discovered in the course of the HARPS M-dwarf survey. We refine the stellar parameters by employing purely empirical mass-luminosity and surface brightness relations constrained by our updated value for the mean stellar density, and additional information from new near-infrared spectroscopic observations. We derive a stellar mass of M{sub *}= 0.539{sup +0.047}{sub -0.043} M{sub sun} and a radius of R{sub *}= 0.568{sup +0.037}{sub -0.031} R{sub sun}. We determine the host star of GJ 3470 b to be metal-rich, with a metallicity of [Fe/H] = +0.20 {+-} 0.10 and an effective temperature of T{sub eff} = 3600 {+-} 100 K. The revised stellar parameters yield a planetary radius R{sub p}= 4.83{sub -0.21}{sup +0.22} R{sub Circled-Plus} that is 13% larger than the value previously reported in the literature. We find a planetary mass M{sub p}= 13.9{sup +1.5}{sub -1.4} M{sub Circled-Plus} that translates to a very low planetary density, {rho}{sub p}= 0.72{sup +0.13}{sub -0.12} g cm{sup -3}, which is 33% smaller than the original value. With a mean density half of that of GJ 436 b, GJ 3470 b is an example of a very low-density low-mass planet, similar to Kepler-11 d, Kepler-11 e, and Kepler-18 c, but orbiting a much brighter nearby star that is more conducive to follow-up studies.

  11. LOCAL BENCHMARKS FOR THE EVOLUTION OF MAJOR-MERGER GALAXIES-SPITZER OBSERVATIONS OF A K-BAND SELECTED SAMPLE

    International Nuclear Information System (INIS)

    Xu, C. Kevin; Cheng Yiwen; Lu Nanyao; Mazzarella, Joseph M.; Cutri, Roc; Domingue, Donovan; Huang Jiasheng; Gao Yu; Sun, W.-H.; Surace, Jason

    2010-01-01

    We present Spitzer observations for a sample of close major-merger galaxy pairs (KPAIR sample) selected from cross-matches between the Two Micron All Sky Survey and Sloan Digital Sky Survey Data Release 3. The goals are to study the star formation activity in these galaxies and to set a local bench mark for the cosmic evolution of close major mergers. The Spitzer KPAIR sample (27 pairs, 54 galaxies) includes all spectroscopically confirmed spiral-spiral (S+S) and spiral-elliptical (S+E) pairs in a parent sample that is complete for primaries brighter than K = 12.5 mag, projected separations of 5 h -1 kpc ≤ s ≤ 20 h -1 kpc, and mass ratios ≤2.5. The Spitzer data, consisting of images in seven bands (3.6, 4.5, 5.8, 8, 24, 70, 160 μm), show very diversified IR emission properties. Compared to single spiral galaxies in a control sample, only spiral galaxies in S+S pairs show significantly enhanced specific star formation rate (sSFR = SFR/M), whereas spiral galaxies in S+E pairs do not. Furthermore, the SFR enhancement of spiral galaxies in S+S pairs is highly mass-dependent. Only those with M ∼> 10 10.5 M sun show significant enhancement. Relatively low-mass (M ∼ 10 10 M sun ) spirals in S+S pairs have about the same SFR/M compared to their counterparts in the control sample, while those with 10 11 M sun have on average a ∼3 times higher SFR/M than single spirals. There is evidence for a correlation between the global star formation activities (but not the nuclear activities) of the component galaxies in massive S+S major-merger pairs (the H olmberg effect ) . There is no significant difference in the SFR/M between the primaries and the secondaries, nor between spirals of SEP KPAIR =2.54 x 10 -4 (M sun yr -1 Mpc -3 ).

  12. Bayesian Inference in Hidden Markov Random Fields for Binary Data Defined on Large Lattices

    NARCIS (Netherlands)

    Friel, N.; Pettitt, A.N.; Reeves, R.; Wit, E.

    Hidden Markov random fields represent a complex hierarchical model, where the hidden latent process is an undirected graphical structure. Performing inference for such models is difficult primarily because the likelihood of the hidden states is often unavailable. The main contribution of this

  13. B-graph sampling to estimate the size of a hidden population

    NARCIS (Netherlands)

    Spreen, M.; Bogaerts, S.

    2015-01-01

    Link-tracing designs are often used to estimate the size of hidden populations by utilizing the relational links between their members. A major problem in studies of hidden populations is the lack of a convenient sampling frame. The most frequently applied design in studies of hidden populations is

  14. Optimisation of Hidden Markov Model using Baum–Welch algorithm ...

    Indian Academy of Sciences (India)

    s12040-016-0780-0. Optimisation of Hidden Markov Model using. Baum–Welch algorithm for prediction of maximum and minimum temperature over Indian Himalaya. J C Joshi1,∗. , Tankeshwar Kumar2, Sunita Srivastava2 and Divya Sachdeva1.

  15. Optimisation of Hidden Markov Model using Baum–Welch algorithm

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 126; Issue 1. Optimisation of Hidden Markov Model using Baum–Welch algorithm for prediction of maximum and minimum temperature over Indian Himalaya. J C Joshi Tankeshwar Kumar Sunita Srivastava Divya Sachdeva. Volume 126 Issue 1 February 2017 ...

  16. Hidden Markov Model for quantitative prediction of snowfall

    Indian Academy of Sciences (India)

    A Hidden Markov Model (HMM) has been developed for prediction of quantitative snowfall in Pir-Panjal and Great Himalayan mountain ranges of Indian Himalaya. The model predicts snowfall for two days in advance using daily recorded nine meteorological variables of past 20 winters from 1992–2012. There are six ...

  17. Prediction of Annual Rainfall Pattern Using Hidden Markov Model ...

    African Journals Online (AJOL)

    ADOWIE PERE

    the stochastic processes is an underlying Markov chain, the other stochastic process is an observable stochastic ... Keywords: Markov model, Hidden Markov model, Transition probability, Observation probability, Crop. Production, Annual Rainfall .... with highest value of the forward probability at time. T+1 is taken as ...

  18. K­MEANS CLUSTERING FOR HIDDEN MARKOV MODEL

    NARCIS (Netherlands)

    Perrone, M.P.; Connell, S.D.

    2004-01-01

    An unsupervised k­means clustering algorithm for hidden Markov models is described and applied to the task of generating subclass models for individual handwritten character classes. The algorithm is compared to a related clustering method and shown to give a relative change in the error rate of as

  19. Education as Text: The Varieties of Educational Hiddenness.

    Science.gov (United States)

    Gordon, David

    1988-01-01

    Using the ideas of Paul Ricoeur and Clifford Geertz, this article develops the notion of education as a "text" and analyzes the "hidden curriculum" of that text as it is read by all members of the society. The hypothesis is proposed that education becomes a text about society's myths and sacred beliefs. (TE)

  20. Pair Hidden Markov Model for Named Entity Matching

    NARCIS (Netherlands)

    Nabende, P.; Tiedemann, J.; Nerbonne, J.; Sobh, T.

    2010-01-01

    This paper introduces a pair-Hidden Markov Model (pair-HMM) for the task of evaluating the similarity between bilingual named entities. The pair-HMM is adapted from Mackay and Kondrak [1] who used it on the task of cognate identification and was later adapted by Wieling et al. [5] for Dutch dialect

  1. Psychosocial aspects of PKU: hidden disabilities--a review.

    Science.gov (United States)

    Gentile, J K; Ten Hoedt, A E; Bosch, A M

    2010-01-01

    Phenylketonuria (PKU) is an inborn error of metabolism, and its detrimental effects on neurocognitive functioning have been well studied. Early detection and treatment of PKU prevent the severe consequences of this disorder. However, even early- and well-treated patients experience hidden disabilities, including subtle deficits in executive functioning, mild reductions in mental processing speed, social difficulties, and emotional problems that may remain unnoticed for years. Poor executive function (EF) may impact treatment adherence and may lead to psychosocial deficits that are not always visible. These psychosocial aspects include social difficulties and psychosocial problems, such as forming interpersonal relationships, achieving autonomy, attaining educational goals, and having healthy emotional development. Studies report EF deficits in children and adults with early-treated PKU, which contribute significantly to the hidden disabilities in this population. In adults, hidden disabilities affect job performance and social relationships as a result of residual attention deficits, poor EF (e.g., planning, organizing), and reduced processing speed. An indirect relationship also exists between quality of life and EF impairment. In the absence of overt psychiatric symptoms, low level depressive or anxious symptom may be present. The interaction between the neurocognitive deficits and psychiatric symptoms puts this population of patients at significant risk for experiencing hidden disability. PKU is a disorder in which a less than optimal psychosocial outcome arises from the cumulative impact of relatively mild symptoms. The key to reducing risks associated with PKU is metabolic control throughout life. Copyright 2009 Elsevier Inc. All rights reserved.

  2. Thermoelectric generator hidden in a shirt with a fabric radiator

    NARCIS (Netherlands)

    Leonov, V.; Vullers, R.J.M.; Hoof, C.V.

    2012-01-01

    Integration of thermopiles in garments has been performed in this work in different ways. It is shown that textile has a minor effect on power generation, which enables completely hidden and unobtrusive energy harvester. A one-milliwatt thermoelectric generator is then integrated between two layers

  3. Phase transitions, interfacial fluctuations and hidden symmetries for ...

    Indian Academy of Sciences (India)

    hidden symmetries for fluids near structured walls. A O PARRY1 and J M ... progress in this area paying particular attention to filling transitions pertinent to fluid adsorption near wedges, which have ..... Recent computer simulation studies of the Ising model are in agreement with these predictions [20,21]. From eqs (8) and ...

  4. Hidden conic quadratic representation of some nonconvex quadratic optimization problems

    NARCIS (Netherlands)

    Ben-Tal, A.; den Hertog, D.

    The problem of minimizing a quadratic objective function subject to one or two quadratic constraints is known to have a hidden convexity property, even when the quadratic forms are indefinite. The equivalent convex problem is a semidefinite one, and the equivalence is based on the celebrated

  5. Hidden Markov model-based approach for generation of Pitman ...

    Indian Academy of Sciences (India)

    Speech is one of the most basic means of human communication. ... human beings is carried out with the aid of communication and has facilitated the development ... Hidden Markov model-based approach for generation of PSL symbols. 279. Table 1. PSL basic strokes and English consonants. English consonant.

  6. A Bayesian Infinite Hidden Markov Vector Autoregressive Model

    NARCIS (Netherlands)

    D. Nibbering (Didier); R. Paap (Richard); M. van der Wel (Michel)

    2016-01-01

    textabstractWe propose a Bayesian infinite hidden Markov model to estimate time-varying parameters in a vector autoregressive model. The Markov structure allows for heterogeneity over time while accounting for state-persistence. By modelling the transition distribution as a Dirichlet process mixture

  7. Measurement problem and local hidden variables with entangled photons

    Science.gov (United States)

    Muchowski, Eugen

    2017-12-01

    It is shown that there is no remote action with polarization measurements of photons in singlet state. A model is presented introducing a hidden parameter which determines the polarizer output. This model is able to explain the polarization measurement results with entangled photons. It is not ruled out by Bell's Theorem.

  8. From epistemology to hidden curriculum: Critical vs. 'commercial' pedagogic perspective

    Directory of Open Access Journals (Sweden)

    Marojević Jovana C.

    2016-01-01

    Full Text Available Knowledge or, more precisely, its power is one of central themes in critical pedagogy. Since they are interested in school as the site of social critique, aimed at social transformations, critically oriented pedagogues pay special attention to the relation of knowledge and power or, to simplify it, the function of knowledge in the reproduction of the existing (often oppressive social relations. Not recognizing school as a mere site of social, economic or cultural preservation, they often study epistemology on which modern school is founded (positivistic epistemology and its hidden curriculum who function so that they legitimate social reproductive function of the school in a continuous cycle of self-justification. Since a certain understanding of knowledge and its function reveals the hidden curriculum of a certain educational philosophy, and since this consequently changes school into a site of social transformation or social transmission, viewed from the critical position this is the subject of the analysis of our paper. By final sublimation and contrasting the opposite positivistic and critical positions we conclude that the hidden curriculum of the first is the curriculum of the soliloquies while the curriculum of the second, critical tendency is entirely of a dialogue nature. It is clear that uni-directedness of the hidden curriculum formed according the postulates of positivistic epistemology can contribute only to positivistic transmission and regeneration of the existing social order, while the discursivity of critically oriented school defines the relation towards society as two-way, transformational, active and emancipatory.

  9. A new 'hidden colour hypothesis' in hadron physics

    Indian Academy of Sciences (India)

    A new `hidden colour hypothesis' within the framework of QCD, as an extension of and in keeping with the spirit of the `colour singlet hypothesis' is hereby proposed. As such it should play a role in a consistent description of exotic hadrons, such as diquonia, pentaquarks, dibaryons etc. How these exotic hadrons are ...

  10. Backward causation, hidden variables and the meaning of ...

    Indian Academy of Sciences (India)

    Backward causation, hidden variables and the meaning of completeness. HUW PRICE. Department of Philosophy, Main Quad, A14, University of Sydney, New South Wales 2006, Australia. Abstract. Bell's theorem ... Certainly, this asymmetry seems to have something to do with our 'knowledge asym- metry' — the fact that ...

  11. Recognizing Strokes in Tennis Videos Using Hidden Markov Models

    NARCIS (Netherlands)

    Petkovic, M.; Jonker, Willem; Zivkovic, Z.

    This paper addresses content-based video retrieval with an emphasis on recognizing events in tennis game videos. In particular, we aim at recognizing different classes of tennis strokes using automatic learning capability of Hidden Markov Models. Driven by our domain knowledge, a robust player

  12. A new 'hidden colour hypothesis' in hadron physics

    Indian Academy of Sciences (India)

    Abstract. A new 'hidden colour hypothesis' within the framework of QCD, as an exten- sion of and in keeping with the spirit of the 'colour singlet hypothesis' is hereby proposed. As such it should play a role in a consistent description of exotic hadrons, such as diquonia, pentaquarks, dibaryons etc. How these exotic hadrons ...

  13. Prediction of annual rainfall pattern using Hidden Markov Model ...

    African Journals Online (AJOL)

    A hidden Markov model to predict annual rainfall pattern has been presented in this paper. The model is developed to provide necessary information for the farmers, agronomists, water resource management scientists and policy makers to enable them plan for the uncertainty of annual rainfall. The model classified annual ...

  14. TeraHertz imaging of hidden paint layers on canvas

    NARCIS (Netherlands)

    Adam, A.J.L.; Planken, P.C.M.; Meloni, S.; Dik, J.

    2009-01-01

    We show terahertz reflection images of hidden paint layers in a painting on canvas and compare the results with X-ray Radiography and Infrared Reflectography. Our terahertz measurements show strong reflections from both the canvas/paint interface and from the raw umber/lead white interface,

  15. Zero Hidden Hunger: From Nariño to Colombia

    International Development Research Centre (IDRC) Digital Library (Canada)

    Zero Hidden Hunger: From Nariño to Colombia. Did you know that in Nariño...? • Children under five have twice the nutritional deficiencies in zinc and iron than the rest of the country (ENSIN 2010). • The menus in government meal programmes include yellow potatoes twice a week and white potatoes three times a week.

  16. A hidden bias in a common calorimeter calibration scheme

    International Nuclear Information System (INIS)

    Lincoln, Don; Morrow, Greg; Kasper, Peter

    1994-01-01

    In this paper, a common calorimeter calibration scheme is explored and a hidden bias found. Since this bias mimics a non-linearity in response in the calorimeter, it must be understood and removed from the calibration before true non-linearities are investigated. The effect and its removal are explored and understood through straightforward calculus and algebra. ((orig.))

  17. The incompatibility between local hidden variable theories and the ...

    Indian Academy of Sciences (India)

    validity of the conservation law alone and this coincides with the quantum mechanical correlation function. Thus, any ... local hidden variable theory, is incompatible with the fundamental conservation laws and space-time ...... of physics on the average, and this indeed is the case for conservation of energy– momentum, and ...

  18. Optimal Number of States in Hidden Markov Models and its ...

    African Journals Online (AJOL)

    In this paper, Hidden Markov Model is applied to model human movements as to facilitate an automatic detection of the same. A number of activities were simulated with the help of two persons. The four movements considered are walking, sitting down-getting up, fall while walking and fall while standing. The data is ...

  19. The hidden magnitude of raised blood pressure and elevated blood ...

    African Journals Online (AJOL)

    user

    The hidden magnitude of raised blood pressure and elevated blood glucose in Ethiopia: A call for initiating community based NCDs risk factors screening program. Abebe Bekele1, Terefe Gelibo1, Kassahun Amenu1, Theodros Getachew1, Atkure Defar1, Habtamu Teklie1,. Tefera Taddele1, Girum Taye1, Misrak Getnet1, ...

  20. Evolving the Topology of Hidden Markov Models using Evolutionary Algorithms

    DEFF Research Database (Denmark)

    Thomsen, Réne

    2002-01-01

    Hidden Markov models (HMM) are widely used for speech recognition and have recently gained a lot of attention in the bioinformatics community, because of their ability to capture the information buried in biological sequences. Usually, heuristic algorithms such as Baum-Welch are used to estimate ...

  1. Crisis Entrepreneurs and Hidden Crises : Illustrative Examples of Interactional

    NARCIS (Netherlands)

    Prof. Cees van Woerkum; dr. Annette Klarenbeek

    2012-01-01

    We examine the ways in which a hidden crisis can be exposed from a communication point of view. In which way can organisations create general awareness of a crisis and try to understand the dynamic nature of interactions? With the help of discourse analysis, we have examined the interactional

  2. Beyond the hidden curriculum: The challenging search for authentic ...

    African Journals Online (AJOL)

    Further, the hidden curriculum is hampered by the challenging medical school workload, bad role models, and lack of appropriate evaluation and assessment methods, as well as the lack of consensus in bioethics on the key concept of human dignity. Properly conceived, the dignity of the human person is the ultimate ...

  3. A novel design of hidden web crawler using ontology

    OpenAIRE

    Manvi; Bhatia, Komal Kumar; Dixit, Ashutosh

    2015-01-01

    Deep Web is content hidden behind HTML forms. Since it represents a large portion of the structured, unstructured and dynamic data on the Web, accessing Deep-Web content has been a long challenge for the database community. This paper describes a crawler for accessing Deep-Web using Ontologies. Performance evaluation of the proposed work showed that this new approach has promising results.

  4. Doing School Time: The Hidden Curriculum Goes to Prison

    Science.gov (United States)

    García, José; De Lissovoy, Noah

    2013-01-01

    The hidden curriculum is generally understood as the process by which daily exposure to school expectations and routines transmits norms and values of the dominant society to students. In the present, through the regimentation of thought, control of bodies and movement, and proliferation of punishment, contemporary accountability and testing…

  5. Hidden Markov model-based approach for generation of Pitman ...

    Indian Academy of Sciences (India)

    In this paper, an approach for feature extraction using Mel frequency cep- stral coefficients (MFCC) and classification using hidden Markov models (HMM) for generating strokes comprising consonants and vowels (CV) in the process of production of Pitman shorthand language from spoken English is proposed. The.

  6. Hidden Markov Model for quantitative prediction of snowfall and ...

    Indian Academy of Sciences (India)

    A Hidden Markov Model (HMM) has been developed for prediction of quantitative snowfall in Pir-Panjal and Great Himalayan mountain ranges of Indian Himalaya. The model predicts snowfall for two days in advance using daily recorded nine meteorological variables of past 20 winters from 1992–2012. There are six ...

  7. The incompatibility between local hidden variable theories and the ...

    Indian Academy of Sciences (India)

    I discuss in detail the result that the Bell's inequalities derived in the context of local hidden variable theories for discrete quantized observables can be satisfied only if a fundamental conservation law is violated on the average. This result shows that such theories are physically nonviable, and makes the demarcating criteria ...

  8. Is the Hidden Curriculum a Relevant Issue in Educational Processes

    Directory of Open Access Journals (Sweden)

    Patarroyo Esther

    2004-08-01

    Full Text Available This paper explores some ideas about the hidden curriculum as an amount of ideas and beliefs which are implicit in an indirect way into the scholar life. Those ideas are regarding to gender equality, social status and racial difference, among others. We consider teachers are able to integrate the hidden curriculum as a pedagogical strategy in the classroom. Examples of integration include activities such as observation techniques, role-plays, peer modeling and particularly, the portfolio as a useful tool for reflection which reveals the hidden curriculum. Key words: Hidden Curriculum, Pedagogical Strategy, Portfolio, ELT Processes, Stereotypes Este documento explora algunas ideas acerca del currículo oculto como una suma de ideas y creencias que están implícitos de una forma indirecta dentro de la vida escolar. Estas ideas están relacionadas con la equidad de género, diferencias sociales y raciales, entre otros. Consideramos que es posible para los docentes integrar el currículo como estrategia pedagógica en el aula. Ejemplos de esta integración incluyen técnicas de observación, juegos de roles, modelamiento en parejas y particularmente, el portafolio como herramienta de reflexión que permita hacer evidente el currículo oculto. Palabras claves: Currículo Oculto, Estrategia Pedagógica, Estereotipos, Enseñanza de Inglés, Portafolio

  9. Hidden, Unacknowledged, Acquaintance, and Date Rape: Looking Back, Looking Forward

    Science.gov (United States)

    Koss, Mary P.

    2011-01-01

    In this commentary, the author reflects on two articles that have been among the most highly cited publications in "Psychology of Women Quarterly" ("PWQ") over its first 35 years, "The Hidden Rape Victim: Personality, Attitudinal, and Situational Characteristics" (Koss, 1985) and "Stranger and Acquaintance Rape: Are There Differences in the…

  10. Hidden attractors without equilibrium and adaptive reduced-order ...

    Indian Academy of Sciences (India)

    2017-03-10

    Mar 10, 2017 ... 1Guangxi Colleges and Universities Key Laboratory of Complex System Optimization and Big Data Processing,. Yulin Normal University, Yulin ... it has been found that chaos is useful in many application fields such as engineer- ... and all applications of chaotic systems or hyperchaotic systems with hidden ...

  11. Hidden symmetries of the Principal Chiral Model unveiled

    International Nuclear Information System (INIS)

    Devchand, C.; Schiff, J.

    1996-12-01

    By relating the two-dimensional U(N) Principal Chiral Model to a Simple linear system we obtain a free-field parametrization of solutions. Obvious symmetry transformations on the free-field data give symmetries of the model. In this way all known 'hidden symmetries' and Baecklund transformations, as well as a host of new symmetries, arise. (author). 21 refs

  12. Resources of learning through hidden curriculum: Iranian nursing students’ perspective

    Science.gov (United States)

    Karimi, Zohreh; Ashktorab, Tahereh; Mohammadi, Eesa; Abedi, Heidarali; Zarea, Kourosh

    2015-01-01

    Background: Students tend to internalize and perpetuate the patterns of behavior and the values surrounding them. Review of literature showed that there are several student learning sources through the hidden curriculum, but they have not been identified in nursing yet. Hence, the purpose of this study is explanation of learning resources in the hidden curriculum in the view of baccalaureate nursing students. Materials and Methods: This qualitative study was carried out in 2012 with the participation of 32 baccalaureate nursing students in Nursing and Midwifery College of Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran by purposeful sampling strategies. Data were collected by semi-structured interviews and continued to the level of data saturation and themes’ emergence. Data analysis was performed through inductive content analysis method. Result: “Instructor as the unique learning element,” “various learning resources in the clinical setting,” and “instructive nature of the education environment” were extracted as the main themes, each of which incorporated some categories. Conclusion: Baccalaureate undergraduate nursing students learnt the hidden curriculum by the resources such as instructors, resources existing in the clinical setting, and the university campus. Therefore, more research is recommended for the identification of other resources. In order to promote positive messages and reduce the negative messages of the hidden curricula running at academic and clinical settings, nursing educators and nurses need to learn more about this issue in the nursing profession. PMID:26430684

  13. Multistability and hidden attractors in a relay system with hysteresis

    DEFF Research Database (Denmark)

    Zhusubaliyev, Zhanybai T.; Mosekilde, Erik; Rubanov, Vasily G.

    2015-01-01

    For nonlinear dynamic systems with switching control, the concept of a "hidden attractor" naturally applies to a stable dynamic state that either (1) coexists with the stable switching cycle or (2), if the switching cycle is unstable, has a basin of attraction that does not intersect with the nei...

  14. Book review: Troubling possibility, hidden fires and secret drawers ...

    African Journals Online (AJOL)

    Book review: Troubling possibility, hidden fires and secret drawers: Tiyambe Zeleza's smouldering charcoal. H.F. Ross. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL.

  15. EVALUASI HIDDEN CURRICULUM DI SMP NEGERI BOJA, KABUPATEN KENDAL

    Directory of Open Access Journals (Sweden)

    Neni Lestari

    2015-12-01

    Full Text Available This study aimed to evaluate the implementation and impact of Hidden Curriculum, as well as the determinant factors of success and sustainability in SMPN 2 Boja Kendal. This study was an evaluative research using qualitative approach. The data collected by using observation, interviews, and documentation. Data analyzed by collecting and selecting to be deduce. Validity used triangulation data that combined the result of observation, interviews, and documentation. The results of the study were: 1 The activities of hidden curriculum development at SMPN 2 Boja Kendal, namely: flag ceremony, school environmental management, establishing and enforcing discipline, special religious worship, smiles, greetings and courtesies, exemplary, relationship among students and principal, teachers, and staff, school canteen services. 2 The impact of the hidden curriculum development was the changing of school community’s behavior being better, created clean and beautiful school environment, the improvement of public trust to the school toward their kids’ education. Development of the hidden curriculum could establish students good character and an optimal achievement as well as a good school culture. 3 Internal supporting factors including: qualified human resources, the availability of school facilities, school environment was clean and beautiful. External supporting factors occur in the form of endorsement of the parents, school committees and communities in establishing good and virtuous character for the students.

  16. The SAURON project - XX. The Spitzer [3.6] - [4.5] colour in early-type galaxies : colours, colour gradients and inverted scaling relations

    NARCIS (Netherlands)

    Peletier, Reynier F.; Kutdemir, Elif; van der Wolk, Guido; Falcon-Barroso, Jesus; Bacon, Roland; Bureau, Martin; Cappellari, Michele; Davies, Roger L.; de Zeeuw, P. Tim; Emsellem, Eric; Krajnovic, Davor; Kuntschner, Harald; McDermid, Richard M.; Sarzi, Marc; Scott, Nicholas; Shapiro, Kristen L.; van den Bosch, Remco C. E.; van de Ven, Glenn

    We investigate the [3.6]-[4.5] Spitzer-IRAC colour behaviour of the early-type galaxies of the SAURON survey, a representative sample of 48 nearby ellipticals and lenticulars. We investigate how this colour, which is unaffected by dust extinction, can be used to constrain the stellar populations in

  17. THE ORIGIN OF THE INFRARED EMISSION IN RADIO GALAXIES. II. ANALYSIS OF MID- TO FAR-INFRARED SPITZER OBSERVATIONS OF THE 2JY SAMPLE

    NARCIS (Netherlands)

    Dicken, D.; Tadhunter, C.; Axon, D.; Morganti, R.; Inskip, K. J.; Holt, J.; Delgado, R. Gonzalez; Groves, B.

    2009-01-01

    We present an analysis of deep mid- to far-infrared (MFIR) Spitzer photometric observations of the southern 2Jy sample of powerful radio sources (0.05

  18. "TNOs are Cool" : A survey of the trans-Neptunian region. IX. Thermal properties of Kuiper belt objects and Centaurs from combined Herschel and Spitzer observations

    NARCIS (Netherlands)

    Lellouch, E.; Santos-Sanz, P.; Lacerda, P.; Mommert, M.; Duffard, R.; Ortiz, J. L.; Müller, T. G.; Fornasier, S.; Stansberry, J.; Kiss, Cs.; Vilenius, E.; Mueller, M.; Peixinho, N.; Moreno, R.; Groussin, O.; Delsanti, A.; Harris, A. W.

    2013-01-01

    Aims: The goal of this work is to characterize the ensemble thermal properties of the Centaurs / trans-Neptunian population. Methods: Thermal flux measurements obtained with Herschel/PACS and Spitzer/MIPS provide size, albedo, and beaming factors for 85 objects (13 of which are presented here for

  19. A hidden Ising model for ChIP-chip data analysis

    KAUST Repository

    Mo, Q.

    2010-01-28

    Motivation: Chromatin immunoprecipitation (ChIP) coupled with tiling microarray (chip) experiments have been used in a wide range of biological studies such as identification of transcription factor binding sites and investigation of DNA methylation and histone modification. Hidden Markov models are widely used to model the spatial dependency of ChIP-chip data. However, parameter estimation for these models is typically either heuristic or suboptimal, leading to inconsistencies in their applications. To overcome this limitation and to develop an efficient software, we propose a hidden ferromagnetic Ising model for ChIP-chip data analysis. Results: We have developed a simple, but powerful Bayesian hierarchical model for ChIP-chip data via a hidden Ising model. Metropolis within Gibbs sampling algorithm is used to simulate from the posterior distribution of the model parameters. The proposed model naturally incorporates the spatial dependency of the data, and can be used to analyze data with various genomic resolutions and sample sizes. We illustrate the method using three publicly available datasets and various simulated datasets, and compare it with three closely related methods, namely TileMap HMM, tileHMM and BAC. We find that our method performs as well as TileMap HMM and BAC for the high-resolution data from Affymetrix platform, but significantly outperforms the other three methods for the low-resolution data from Agilent platform. Compared with the BAC method which also involves MCMC simulations, our method is computationally much more efficient. Availability: A software called iChip is freely available at http://www.bioconductor.org/. Contact: moq@mskcc.org. © The Author 2010. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org.

  20. A Polarimetric Search for Hidden Quasars in Three Radio-selected Ultraluminous Infrared Galaxies

    International Nuclear Information System (INIS)

    Tran, H.D.; Brotherton, M.S.; Stanford, S.A.; Breugel, W. van; Dey, A.; Stern, D.; Antonucci, R.

    1999-01-01

    We have carried out a spectropolarimetric search for hidden broad-line quasars in three ultraluminous infrared galaxies (ULIRGs) discovered in the positional correlations between sources detected in deep radio surveys and the IRAS Faint Source Catalog. Only the high-ionization Seyfert 2 galaxy TF J1736+1122 is highly polarized, displaying a broad-line spectrum visible in polarized light. The other two objects, TF J1020+6436 and FF J1614+3234, display spectra dominated by a population of young (A type) stars similar to those of open-quotes E+Aclose quotes galaxies. They are unpolarized, showing no sign of hidden broad-line regions. The presence of young starburst components in all three galaxies indicates that the ULIRG phenomenon encompasses both active galactic nuclei (AGNs) and starburst activity, but the most energetic ULIRGs do not necessarily harbor open-quotes buried quasars.close quotes We find that a luminous infrared galaxy is most likely to host an obscured quasar if it exhibits a high-ionization ([O iii] λ5007/Hβ approx-gt 5) spectrum typical of a 'classic' Seyfert 2 galaxy with little or no Balmer absorption lines, is 'ultraluminous' (L IR approx-gt 10 12 L circle-dot ), and has a 'warm' IR color (f 25 /f 60 approx-gt 0.25). The detection of hidden quasars in this group but not in the low-ionization, starburst-dominated ULIRGs (classified as LINERs or H ii galaxies) may indicate an evolutionary connection, with the latter being found in younger systems. copyright copyright 1999. The American Astronomical Society

  1. A hidden Ising model for ChIP-chip data analysis.

    Science.gov (United States)

    Mo, Qianxing; Liang, Faming

    2010-03-15

    Chromatin immunoprecipitation (ChIP) coupled with tiling microarray (chip) experiments have been used in a wide range of biological studies such as identification of transcription factor binding sites and investigation of DNA methylation and histone modification. Hidden Markov models are widely used to model the spatial dependency of ChIP-chip data. However, parameter estimation for these models is typically either heuristic or suboptimal, leading to inconsistencies in their applications. To overcome this limitation and to develop an efficient software, we propose a hidden ferromagnetic Ising model for ChIP-chip data analysis. We have developed a simple, but powerful Bayesian hierarchical model for ChIP-chip data via a hidden Ising model. Metropolis within Gibbs sampling algorithm is used to simulate from the posterior distribution of the model parameters. The proposed model naturally incorporates the spatial dependency of the data, and can be used to analyze data with various genomic resolutions and sample sizes. We illustrate the method using three publicly available datasets and various simulated datasets, and compare it with three closely related methods, namely TileMap HMM, tileHMM and BAC. We find that our method performs as well as TileMap HMM and BAC for the high-resolution data from Affymetrix platform, but significantly outperforms the other three methods for the low-resolution data from Agilent platform. Compared with the BAC method which also involves MCMC simulations, our method is computationally much more efficient. A software called iChip is freely available at http://www.bioconductor.org/. moq@mskcc.org.

  2. SPITZER EVIDENCE FOR A LATE-HEAVY BOMBARDMENT AND THE FORMATION OF UREILITES IN η CORVI At ∼1 Gyr

    International Nuclear Information System (INIS)

    We have analyzed Spitzer and NASA/IRTF 2-35 μm spectra of the warm, ∼350 K circumstellar dust around the nearby MS star η Corvi (F2V, 1.4 ± 0.3 Gyr). The spectra show clear evidence for warm, water- and carbon-rich dust at ∼3 AU from the central star, in the system's terrestrial habitability zone. Spectral features due to ultra-primitive cometary material were found, in addition to features due to impact produced silica and high-temperature carbonaceous phases. At least 9 × 10 18 kg of 0.1-100 μm warm dust is present in a collisional equilibrium distribution with dn/da ∼ a –3.5 , the equivalent of a 130 km radius Kuiper Belt object (KBO) of 1.0 g cm 3 density and similar to recent estimates of the mass delivered to the Earth at 0.6-0.8 Gyr during the late-heavy bombardment. We conclude that the parent body was a Kuiper Belt body or bodies which captured a large amount of early primitive material in the first megayears of the system's lifetime and preserved it in deep freeze at ∼150 AU. At ∼1.4 Gyr they were prompted by dynamical stirring of their parent Kuiper Belt into spiraling into the inner system, eventually colliding at 5-10 km s –1 with a rocky planetary body of mass ≤M Earth at ∼3 AU, delivering large amounts of water (>0.1% of M Earth'sOceans ) and carbon-rich material. The Spitzer spectrum also closely matches spectra reported for the Ureilite meteorites of the Sudan Almahata Sitta fall in 2008, suggesting that one of the Ureilite parent bodies was a KBO.

  3. Spitzer Infrared Spectrograph Observations of the Galactic Center: Quantifying the Extreme Ultraviolet/Soft X-ray Fluxes

    Science.gov (United States)

    Simpson, Janet P.

    2018-04-01

    It has long been shown that the extreme ultraviolet spectrum of the ionizing stars of H II regions can be estimated by comparing the observed line emission to detailed models. In the Galactic Center (GC), however, previous observations have shown that the ionizing spectral energy distribution (SED) of the local photon field is strange, producing both very low excitation ionized gas (indicative of ionization by late O stars) and also widespread diffuse emission from atoms too highly ionized to be found in normal H II regions. This paper describes the analysis of all GC spectra taken by Spitzer's Infrared Spectrograph and downloaded from the Spitzer Heritage Archive. In it, H II region densities and abundances are described, and serendipitously discovered candidate planetary nebulae, compact shocks, and candidate young stellar objects are tabulated. Models were computed with Cloudy, using SEDs from Starburst99 plus additional X-rays, and compared to the observed mid-infrared forbidden and recombination lines. The ages inferred from the model fits do not agree with recent proposed star formation sequences (star formation in the GC occurring along streams of gas with density enhancements caused by close encounters with the black hole, Sgr A*), with Sgr B1, Sgr C, and the Arches Cluster being all about the same age, around 4.5 Myr old, with similar X-ray requirements. The fits for the Quintuplet Cluster appear to give a younger age, but that could be caused by higher-energy photons from shocks from stellar winds or from a supernova.

  4. Spitzer Evidence for a Late Heavy Bombardment and the Formation of Urelites in {eta}Corvi at Approximately 1 Gyr

    Science.gov (United States)

    Lisse, C. M.; Wyatt, M. C.; Chen, C. H.; Morlok, A.; Watson, D. M.; Manj, P.; Sheehan, P.; Currie, T. M.; Thebault, P.; Sitko, M. L.

    2011-01-01

    We have analyzed Spitzer and NASA/IRTF 2 - 35 micrometer spectra of the warm, 350 K circumstellar dust around the nearby MS star eta Corvi (F2V, 1.4 plus or minus 0.3 Gyr). The spectra show clear evidence for warm, water- and carbon-rich dust at 3 AU from the central star, in the system's Terrestrial Habitability Zone. Spectral features due to ultra-primitive cometary material were found, in addition to features due to impact produced silica and high temperature carbonaceous phases. At least 9 x 10(exp 18) kg of 0.1 - 100 micrometer warm dust is present in a collisional equilibrium distribution with dn/da a(exp -3.5), the equivalent of a 130 km radius KBO of 1.0 grams per cubic centimeter density and similar to recent estimates of the mass delivered to the Earth at 0.6 - 0.8 Gyr during the Late Heavy Bombardment. We conclude that the parent body was a Kuiper-Belt body or bodies which captured a large amount of early primitive material in the first Myrs of the system's lifetime and preserved it in deep freeze at approximately 150 AU. At approximately 1.4 Gyr they were prompted by dynamical stirring of their parent Kuiper Belt into spiraling into the inner system, eventually colliding at 5-10 kilometers per second with a rocky planetary body of mass less than or equal to M(sub Earth at approximately 3 AU, delivering large amounts of water (greater than 0.1 % of M(sub Earth's Oceans)) and carbon-rich material. The Spitzer spectrum also closely matches spectra reported for the Ureilite meteorites of the Sudan Almahata Sitta fall in 2008, suggesting that one of the Ureilite parent bodies was a KBO.

  5. SPITZER EVIDENCE FOR A LATE-HEAVY BOMBARDMENT AND THE FORMATION OF UREILITES IN {eta} CORVI At {approx}1 Gyr

    Energy Technology Data Exchange (ETDEWEB)

    Lisse, C. M. [JHU-APL, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Wyatt, M. C. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge, CB3 0HA (United Kingdom); Chen, C. H. [STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Morlok, A. [Department of Earth and Planetary Sciences, The Open University, Milton-Keynes (United Kingdom); Watson, D. M.; Manoj, P.; Sheehan, P. [Department of Physics and Astronomy, University of Rochester, Rochester, NY (United States); Currie, T. M. [NASA-GSFC, Code 667, Greenbelt, MD 20771 (United States); Thebault, P. [Observatoire de Paris, F-92195 Meudon Principal Cedex (France); Sitko, M. L., E-mail: carey.lisse@jhuapl.edu, E-mail: wyatt@ast.cam.ac.uk, E-mail: cchen@stsci.edu, E-mail: a.morlok@open.ac.uk, E-mail: dmw@pas.rochester.edu, E-mail: manoj@pas.rochester.edu, E-mail: psheeha2@mail.rochester.edu, E-mail: thayne.m.currie@nasa.gov, E-mail: philippe.thebault@obspm.fr, E-mail: sitko@spacescience.org [Space Science Institute, 475 Walnut Street, Suite 205, Boulder, CO 80301 (United States)

    2012-03-10

    We have analyzed Spitzer and NASA/IRTF 2-35 {mu}m spectra of the warm, {approx}350 K circumstellar dust around the nearby MS star {eta} Corvi (F2V, 1.4 {+-} 0.3 Gyr). The spectra show clear evidence for warm, water- and carbon-rich dust at {approx}3 AU from the central star, in the system's terrestrial habitability zone. Spectral features due to ultra-primitive cometary material were found, in addition to features due to impact produced silica and high-temperature carbonaceous phases. At least 9 Multiplication-Sign 10{sup 18} kg of 0.1-100 {mu}m warm dust is present in a collisional equilibrium distribution with dn/da {approx} a{sup -3.5}, the equivalent of a 130 km radius Kuiper Belt object (KBO) of 1.0 g cm{sup 3} density and similar to recent estimates of the mass delivered to the Earth at 0.6-0.8 Gyr during the late-heavy bombardment. We conclude that the parent body was a Kuiper Belt body or bodies which captured a large amount of early primitive material in the first megayears of the system's lifetime and preserved it in deep freeze at {approx}150 AU. At {approx}1.4 Gyr they were prompted by dynamical stirring of their parent Kuiper Belt into spiraling into the inner system, eventually colliding at 5-10 km s{sup -1} with a rocky planetary body of mass {<=}M{sub Earth} at {approx}3 AU, delivering large amounts of water (>0.1% of M{sub Earth'sOceans}) and carbon-rich material. The Spitzer spectrum also closely matches spectra reported for the Ureilite meteorites of the Sudan Almahata Sitta fall in 2008, suggesting that one of the Ureilite parent bodies was a KBO.

  6. THE SPITZER SURVEY OF INTERSTELLAR CLOUDS IN THE GOULD BELT. IV. LUPUS V AND VI OBSERVED WITH IRAC AND MIPS

    International Nuclear Information System (INIS)

    Spezzi, Loredana; Vernazza, Pierre; Merin, Bruno; Allen, Lori E.; Evans, Neal J. II; Harvey, Paul M.; Joergensen, Jes K.; Bourke, Tyler L.; Peterson, Dawn; Cieza, Lucas A.; Dunham, Michael M.; Huard, Tracy L.; Tothill, Nick F. H.

    2011-01-01

    We present Gould's Belt (GB) Spitzer IRAC and MIPS observations of the Lupus V and VI clouds and discuss them in combination with near-infrared (2MASS) data. Our observations complement those obtained for other Lupus clouds within the frame of the Spitzer C ore to Disk(c2d) Legacy Survey. We found 43 young stellar object (YSO) candidates in Lupus V and 45 in Lupus VI, including two transition disks, using the standard c2d/GB selection method. None of these sources was classified as a pre-main-sequence star from previous optical, near-IR, and X-ray surveys. A large majority of these YSO candidates appear to be surrounded by thin disks (Class III; ∼79% in Lupus V and ∼87% in Lupus VI). These Class III abundances differ significantly from those observed for the other Lupus clouds and c2d/GB surveyed star-forming regions, where objects with optically thick disks (Class II) dominate the young population. We investigate various scenarios that can explain this discrepancy. In particular, we show that disk photoevaporation due to nearby OB stars is not responsible for the high fraction of Class III objects. The gas surface densities measured for Lupus V and VI lie below the star formation threshold (A V ∼ 8.6 mag), while this is not the case for other Lupus clouds. Thus, few Myr older age for the YSOs in Lupus V and VI with respect to other Lupus clouds is the most likely explanation of the high fraction of Class III objects in these clouds, while a higher characteristic stellar mass might be a contributing factor. Better constraints on the age and binary fraction of the Lupus clouds might solve the puzzle but require further observations.

  7. A SPITZER MIPS STUDY OF 2.5-2.0 M{sub Sun} STARS IN SCORPIUS-CENTAURUS

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Christine H.; Bitner, Martin [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Pecaut, Mark; Mamajek, Eric E. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 (United States); Su, Kate Y. L., E-mail: cchen@stsci.edu [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2012-09-10

    We have obtained Spitzer Space Telescope Multiband Imaging Photometer for Spitzer (MIPS) 24 {mu}m and 70 {mu}m observations of 215 nearby, Hipparcos B- and A-type common proper-motion single and binary systems in the nearest OB association, Scorpius-Centaurus. Combining our MIPS observations with those of other ScoCen stars in the literature, we estimate 24 {mu}m B+A-type disk fractions of 17/67 (25{sup +6}{sub -5}%), 36/131 (27{sup +4}{sub -4}%), and 23/95 (24{sup +5}{sub -4}%) for Upper Scorpius ({approx}11 Myr), Upper Centaurus Lupus ({approx}15 Myr), and Lower Centaurus Crux ({approx}17 Myr), respectively, somewhat smaller disk fractions than previously obtained for F- and G-type members. We confirm previous IRAS excess detections and present new discoveries of 51 protoplanetary and debris disk systems, with fractional infrared luminosities ranging from L{sub IR}/L{sub *} = 10{sup -6} to 10{sup -2} and grain temperatures ranging from T{sub gr} = 40 to 300 K. In addition, we confirm that the 24 {mu}m and 70 {mu}m excesses (or fractional infrared luminosities) around B+A-type stars are smaller than those measured toward F+G-type stars and hypothesize that the observed disk property dependence on stellar mass may be the result of a higher stellar companion fraction around B- and A-type stars at 10-200 AU. Finally, we note that the majority of the ScoCen 24 {mu}m excess sources also possess 12 {mu}m excess, indicating that Earth-like planets may be forming via collisions in the terrestrial planet zone at {approx}10-100 Myr.

  8. Exciton dynamics reveal aggregates with intermolecular order at hidden interfaces in solution-cast organic semiconducting films.

    Science.gov (United States)

    Wong, Cathy Y; Cotts, Benjamin L; Wu, Hao; Ginsberg, Naomi S

    2015-01-12

    Large-scale organic electronics manufacturing requires solution processing. For small-molecule organic semiconductors, solution processing results in crystalline domains with high charge mobility, but the interfaces between these domains impede charge transport, degrading device performance. Although understanding these interfaces is essential to improve device performance, their intermolecular and electronic structure is unknown: they are smaller than the diffraction limit, are hidden from surface probe techniques, and their nanoscale heterogeneity is not typically resolved using X-ray methods. Here we use transient absorption microscopy to isolate a unique signature of a hidden interface in a TIPS-pentacene thin film, exposing its exciton dynamics and intermolecular structure. Surprisingly, instead of finding an abrupt grain boundary, we reveal that the interface can be composed of nanoscale crystallites interleaved by a web of interfaces that compound decreases in charge mobility. Our novel approach provides critical missing information on interface morphology necessary to correlate solution-processing methods to optimal device performance.

  9. Hidden photons in beam dump experiments and in connection with dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Andreas, Sarah

    2012-12-15

    Hidden sectors with light extra U(1) gauge bosons, so-called hidden photons, recently received much interest as natural feature of beyond standard model scenarios like string theory and SUSY and because of their possible connection to dark matter. This paper presents limits on hidden photons from past electron beam dump experiments including two new limits from experiments at KEK and Orsay. Additionally, various hidden sector models containing both a hidden photon and a dark matter candidate are discussed with respect to their viability and potential signatures in direct detection.

  10. Parsing social network survey data from hidden populations using stochastic context-free grammars.

    Directory of Open Access Journals (Sweden)

    Art F Y Poon

    Full Text Available BACKGROUND: Human populations are structured by social networks, in which individuals tend to form relationships based on shared attributes. Certain attributes that are ambiguous, stigmatized or illegal can create a OhiddenO population, so-called because its members are difficult to identify. Many hidden populations are also at an elevated risk of exposure to infectious diseases. Consequently, public health agencies are presently adopting modern survey techniques that traverse social networks in hidden populations by soliciting individuals to recruit their peers, e.g., respondent-driven sampling (RDS. The concomitant accumulation of network-based epidemiological data, however, is rapidly outpacing the development of computational methods for analysis. Moreover, current analytical models rely on unrealistic assumptions, e.g., that the traversal of social networks can be modeled by a Markov chain rather than a branching process. METHODOLOGY/PRINCIPAL FINDINGS: Here, we develop a new methodology based on stochastic context-free grammars (SCFGs, which are well-suited to modeling tree-like structure of the RDS recruitment process. We apply this methodology to an RDS case study of injection drug users (IDUs in Tijuana, México, a hidden population at high risk of blood-borne and sexually-transmitted infections (i.e., HIV, hepatitis C virus, syphilis. Survey data were encoded as text strings that were parsed using our custom implementation of the inside-outside algorithm in a publicly-available software package (HyPhy, which uses either expectation maximization or direct optimization methods and permits constraints on model parameters for hypothesis testing. We identified significant latent variability in the recruitment process that violates assumptions of Markov chain-based methods for RDS analysis: firstly, IDUs tended to emulate the recruitment behavior of their own recruiter; and secondly, the recruitment of like peers (homophily was dependent on

  11. Study of the discovery potential for hidden photon emission at future electron scattering fixed-target experiments

    Science.gov (United States)

    Beranek, T.; Vanderhaeghen, M.

    2014-03-01

    Recently, electron scattering fixed-target experiments came into focus to search for U(1) extensions of the Standard Model of particle physics at low energies. These extensions are motivated from anomalies in astrophysical observations as well as from deviations from Standard Model predictions, such as the discrepancy between the experimental and theoretical determinations of the anomalous magnetic moment of the muon. In such U(1) extensions, a new, light messenger particle γ', the hidden photon, couples to the hidden sector as well as to the electromagnetic current of the Standard Model by kinetic mixing, which allows for a search for this particle, e.g., in the invariant mass distribution of the process e(A ,Z)→e(A,Z)l+l-. In this process the hidden photon is emitted by bremsstrahlung and decays into a pair of Standard Model leptons. In this work we study the applicability of the Weizsäcker-Williams approximation to calculate the signal cross section of the process, which is widely used to design such experimental setups. Furthermore, we study the influence of the contribution from doubly virtual Compton scattering on experiments performed with proton targets. Based on a previous work, we investigate the discovery potential of future experimental setups at the Jefferson Lab and obtain a projected exclusion limit. We find that doubly virtual Compton scattering causes a 10% effect on the cross section for the kinematics of a planned experiment and therefore does not alter the obtained experimental reach significantly. In addition, we find that the Weizsäcker-Williams approximation can be applied to calculate the underlying cross sections in the kinematic range of most of the present and upcoming experiments, provided that the dependence on the energy and emission angle of the hidden photon is accounted for.

  12. Hidden SUSY from precision gauge unification

    International Nuclear Information System (INIS)

    Krippendorf, Sven; Nilles, Hans Peter

    2013-06-01

    We revisit the implications of naturalness and gauge unification in the MSSM. We find that precision unification of the couplings in connection with a small μ parameter requires a highly compressed gaugino pattern as it is realized in mirage mediation. Due to the small mass difference between gluino and LSP, collider limits on the gluino mass are drastically relaxed. Without further assumptions, the relic density of the LSP is very close to the observed dark matter density due to coannihilation effects.

  13. An impossibility theorem for parameter independent hidden variable theories

    Science.gov (United States)

    Leegwater, Gijs

    2016-05-01

    Recently, Roger Colbeck and Renato Renner (C&R) have claimed that '[n]o extension of quantum theory can have improved predictive power' (Colbeck & Renner, 2011, 2012b). If correct, this is a spectacular impossibility theorem for hidden variable theories, which is more general than the theorems of Bell (1964) and Leggett (2003). Also, C&R have used their claim in attempt to prove that a system's quantum-mechanical wave function is in a one-to-one correspondence with its 'ontic' state (Colbeck & Renner, 2012a). C&R's claim essentially means that in any hidden variable theory that is compatible with quantum-mechanical predictions, probabilities of measurement outcomes are independent of these hidden variables. This makes such variables otiose. On closer inspection, however, the generality and validity of the claim can be contested. First, it is based on an assumption called 'Freedom of Choice'. As the name suggests, this assumption involves the independence of an experimenter's choice of measurement settings. But in the way C&R define this assumption, a no-signalling condition is surreptitiously presupposed, making the assumption less innocent than it sounds. When using this definition, any hidden variable theory violating parameter independence, such as Bohmian Mechanics, is immediately shown to be incompatible with quantum-mechanical predictions. Also, the argument of C&R is hard to follow and their mathematical derivation contains several gaps, some of which cannot be closed in the way they suggest. We shall show that these gaps can be filled. The issue with the 'Freedom of Choice' assumption can be circumvented by explicitly assuming parameter independence. This makes the result less general, but better founded. We then obtain an impossibility theorem for hidden variable theories satisfying parameter independence only. As stated above, such hidden variable theories are impossible in the sense that any supplemental variables have no bearing on outcome probabilities

  14. Speech-To-Text Conversion STT System Using Hidden Markov Model HMM

    Directory of Open Access Journals (Sweden)

    Su Myat Mon

    2015-06-01

    Full Text Available Abstract Speech is an easiest way to communicate with each other. Speech processing is widely used in many applications like security devices household appliances cellular phones ATM machines and computers. The human computer interface has been developed to communicate or interact conveniently for one who is suffering from some kind of disabilities. Speech-to-Text Conversion STT systems have a lot of benefits for the deaf or dumb people and find their applications in our daily lives. In the same way the aim of the system is to convert the input speech signals into the text output for the deaf or dumb students in the educational fields. This paper presents an approach to extract features by using Mel Frequency Cepstral Coefficients MFCC from the speech signals of isolated spoken words. And Hidden Markov Model HMM method is applied to train and test the audio files to get the recognized spoken word. The speech database is created by using MATLAB.Then the original speech signals are preprocessed and these speech samples are extracted to the feature vectors which are used as the observation sequences of the Hidden Markov Model HMM recognizer. The feature vectors are analyzed in the HMM depending on the number of states.

  15. A Hidden Markov Model for Urban-Scale Traffic Estimation Using Floating Car Data.

    Science.gov (United States)

    Wang, Xiaomeng; Peng, Ling; Chi, Tianhe; Li, Mengzhu; Yao, Xiaojing; Shao, Jing

    2015-01-01

    Urban-scale traffic monitoring plays a vital role in reducing traffic congestion. Owing to its low cost and wide coverage, floating car data (FCD) serves as a novel approach to collecting traffic data. However, sparse probe data represents the vast majority of the data available on arterial roads in most urban environments. In order to overcome the problem of data sparseness, this paper proposes a hidden Markov model (HMM)-based traffic estimation model, in which the traffic condition on a road segment is considered as a hidden state that can be estimated according to the conditions of road segments having similar traffic characteristics. An algorithm based on clustering and pattern mining rather than on adjacency relationships is proposed to find clusters with road segments having similar traffic characteristics. A multi-clustering strategy is adopted to achieve a trade-off between clustering accuracy and coverage. Finally, the proposed model is designed and implemented on the basis of a real-time algorithm. Results of experiments based on real FCD confirm the applicability, accuracy, and efficiency of the model. In addition, the results indicate that the model is practicable for traffic estimation on urban arterials and works well even when more than 70% of the probe data are missing.

  16. Hidden markers, open secrets: on naming, race-marking, and race-making in Cuba

    Directory of Open Access Journals (Sweden)

    Michael Zeuske

    2002-07-01

    Full Text Available Focuses on how in Cuba race-marking was interrelated with surname-giving, also after the abolition of slavery. Through researching life histories on the local level in the Cienfuegos region, the author examines names of former slaves, finding that these were after abolition in notarial records often marked with the adjectives s.o.a., or "sin otro apellido" (without other surname, taking into account the Iberian double surname tradition. This, according to him, points to a stigmatization of these black citizens and related to their former status as possession, and is thus a racial marker, only more hidden than the open racial assignations during slavery. He relates these postemancipation surnames of former slaves to the dotation of surnames during slavery, whereby most surnames of slaves were those of the last owner of the slaves. He also discusses differences in name-giving between the notarial records and everyday life. He further indicates that a new racism developed in the Cuban society of the late 19th c. and early 20th c., which was voiced more openly in the realm of culture, and regarding events as incarceration and death, and more hidden within the civil and judicial spheres, where the fiction of a race-blind republic was maintained.

  17. Cervical lymphadenopathy: Unwinding the hidden truth

    Directory of Open Access Journals (Sweden)

    Athira Aruna Ramadas

    2017-01-01

    Full Text Available Lymphadenopathy is a common clinical finding in a patient seeking oral health care. It may be in a localized, limited, or generalized form. Malignancies, infections, autoimmune disorders, iatrogenic, and other miscellaneous conditions are considered as the causes for cervical lymphadenopathy. Unexplained cervical lymphadenopathy is a cause of concern for physician and patient because sometimes it could be the manifestation of an underlying malignancy. However, a methodological approach to lymphadenopathy can disclose the accurate diagnosis causing minimal discomfort for the patient and in a short time. This paper reports the significance of cervical lymph node examination and ensuing investigations, which led to a diagnosis of non-Hodgkins lymphoma.

  18. HMMEditor: a visual editing tool for profile hidden Markov model

    Directory of Open Access Journals (Sweden)

    Cheng Jianlin

    2008-03-01

    Full Text Available Abstract Background Profile Hidden Markov Model (HMM is a powerful statistical model to represent a family of DNA, RNA, and protein sequences. Profile HMM has been widely used in bioinformatics research such as sequence alignment, gene structure prediction, motif identification, protein structure prediction, and biological database search. However, few comprehensive, visual editing tools for profile HMM are publicly available. Results We develop a visual editor for profile Hidden Markov Models (HMMEditor. HMMEditor can visualize the profile HMM architecture, transition probabilities, and emission probabilities. Moreover, it provides functions to edit and save HMM and parameters. Furthermore, HMMEditor allows users to align a sequence against the profile HMM and to visualize the corresponding Viterbi path. Conclusion HMMEditor provides a set of unique functions to visualize and edit a profile HMM. It is a useful tool for biological sequence analysis and modeling. Both HMMEditor software and web service are freely available.

  19. Hidden magnetism in periodically modulated one dimensional dipolar fermions

    Science.gov (United States)

    Fazzini, S.; Montorsi, A.; Roncaglia, M.; Barbiero, L.

    2017-12-01

    The experimental realization of time-dependent ultracold lattice systems has paved the way towards the implementation of new Hubbard-like Hamiltonians. We show that in a one-dimensional two-components lattice dipolar Fermi gas the competition between long range repulsion and correlated hopping induced by periodically modulated on-site interaction allows for the formation of hidden magnetic phases, with degenerate protected edge modes. The magnetism, characterized solely by string-like nonlocal order parameters, manifests in the charge and/or in the spin degrees of freedom. Such behavior is enlighten by employing Luttinger liquid theory and numerical methods. The range of parameters for which hidden magnetism is present can be reached by means of the currently available experimental setups and probes.

  20. Heavy superpartners with less tuning from hidden sector renormalisation

    International Nuclear Information System (INIS)

    Hardy, Edward

    2014-01-01

    In supersymmetric extensions of the Standard Model, superpartner masses consistent with collider bounds typically introduce significant tuning of the electroweak scale. We show that hidden sector renormalisation can greatly reduce such a tuning if the supersymmetry breaking, or mediating, sector runs through a region of strong coupling not far from the weak scale. In the simplest models, only the tuning due to the gaugino masses is improved, and a weak scale gluino mass in the region of 5 TeV may be obtained with an associated tuning of only one part in ten. In models with more complex couplings between the visible and hidden sectors, the tuning with respect to sfermions can also be reduced. We give an example of a model, with low scale gauge mediation and superpartner masses allowed by current LHC bounds, that has an overall tuning of one part in twenty