Impaired Communication Between the Motor and Somatosensory Homunculus Is Associated With Poor Manual Dexterity in Autism Spectrum Disorder.

PubMed

Thompson, Abigail; Murphy, Declan; Dell'Acqua, Flavio; Ecker, Christine; McAlonan, Grainne; Howells, Henrietta; Baron-Cohen, Simon; Lai, Meng-Chuan; Lombardo, Michael V

2017-02-01

Fine motor skill impairments are common in autism spectrum disorder (ASD), significantly affecting quality of life. Sensory inputs reaching the primary motor cortex (M1) from the somatosensory cortex (S1) are likely involved in fine motor skill and specifically motor learning. However, the role of these connections has not been directly investigated in humans. This study aimed to investigate, for the first time, the role of the S1-M1 connections in healthy subjects in vivo and whether microstructural alterations are associated with motor impairment in ASD. Sixty right-handed neurotypical adult men aged 18 to 45 years, and 60 right-handed age- and sex-matched subjects diagnosed with ASD underwent fine motor skill assessment and scanning with diffusion tensor imaging (DTI). The streamlines of the hand region connecting S1-M1 of the motor-sensory homunculus were virtually dissected using TrackVis, and diffusion properties were extracted. The face/tongue region connections were used as control tracts. The ASD group displayed lower motor performances and altered DTI measurements of the hand-region connection. Behavioral performance correlated with hand-region DTI measures in both groups, but not with the face/tongue connections, indicating anatomical specificity. There was a left-hemisphere association of motor ability in the control group and an atypical rightward shift in the ASD group. These findings suggest that direct interaction between S1 and M1 may contribute to the human ability to precisely interact with and manipulate the environment. Because electrophysiological evidence indicates that these connections may underpin long-term potentiation in M1, our findings may lead to novel therapeutic treatments for motor skill disorders. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

[The Competence Network for HIV/AIDS. Data, Samples, Facts].

PubMed

Michalik, Claudia; Skaletz-Rorowski, Adriane; Brockmeyer, Norbert H

2016-04-01

With funding for the Competence Networks in Medicine from the Federal Ministry of Education and Research, the Competence Network for HIV/AIDS (KompNet HIV/AIDS) was established as an interdisciplinary research association. Essential working groups were incorporated all over Germany, which are active in clinical and basic HIV/AIDS research. After successful establishment, providing research infrastructure for national and international cooperation in the field of HIV/AIDS was the focus of the network. By bringing together research activities, preconditions are created for improving HIV infection treatment and increasing life expectancy of HIV-infected patients. The members of KompNet HIV/AIDS are HIV experts from university clinics, HIV physicians, patient representatives, as well as national reference centers. As a scientific research basis, the network established an HIV patient cohort. Clinical and sociodemographic data of HIV patients were documented biannually and complemented by serum and DNA-samples collected twice per year. Furthermore, a child cohort was set up. Within the KompNet HIV/AIDS, a research infrastructure for HIV was established for internal, external as well international scientists. Within the HIV cohort a total of 16,500 patients are documented. The associated biobank comprises ~ 56,000 serum samples and ~ 16,000 DNA samples. The child cohort consists of 647 HIV-exposed and 230 infected children. The KompNet HIV/AIDS cohorts became an important partner in several international collaborations. Nevertheless, the maintenance of such infrastructures without public funding is a challenge.

Incidence and risk factors of herpes zoster among hiv-positive patients in the german competence network for HIV/AIDS (KompNet): a cohort study analysis.

PubMed

Jansen, Klaus; Haastert, Burkhard; Michalik, Claudia; Guignard, Adrienne; Esser, Stefan; Dupke, Stephan; Plettenberg, Andreas; Skaletz-Rorowski, Adriane; Brockmeyer, Norbert H

2013-08-10

HIV infection is a risk factor for the development of Herpes zoster (HZ) and its complications. Prior to antiretroviral therapy (ART), HZ incidence in HIV-infected individuals ranged from 2.9-5.1/100 person-years. There is limited evidence for the impact of ART on HZ occurrence among HIV-infected adults. We analysed the incidence of, and risk factors for, HZ in a large cohort of German HIV-positive patients. The study population was taken from the German KompNet cohort, a nationwide multicenter HIV cohort study. The study population was defined by age (≥ 18 years), year of first positive HIV diagnosis, CD4 values ± 6 months from HIV diagnosis (t0), and month of HZ diagnosis. Incidences were estimated using a Poisson distribution, and uni- and multivariate Cox proportional Hazard ratio (HR) regression models were fitted to identify risk factors for developing an initial HZ episode. Independent variables were sex, age at HIV diagnosis, route of HIV transmission, ART status, CD4 count before HZ episode, immunosuppressive medication, and mode of data documentation (retrospective or prospective). HZ incidence in the overall study population was 1.2/100 person-years. In a subset of patients for that we were able to examine risk factors the following was observed: We examined 3,757 individuals whose mean age at t0 was 38 years. Of those individuals, 96% were diagnosed with HIV in 1996 or later, with a mean observation time of 5.8 years. HZ episodes (n = 362) were recorded in 326 patients (8.7%), resulting in annual HZ incidences of 1.7/100 person-years overall, and 1.6/100 person-years for initial HZ cases. The main risk factors associated with an initial HZ episode were: not partaking in ART compared with an ART regimen containing a non-nucleoside reverse-transcriptase inhibitor (HR 0.530, p < 0.001) or a protease inhibitor (HR 0.624, p = 0.004); and lower CD4 count by 100 cells/μl (HR 0.918, p=0.001). HZ incidence was 4-11-fold higher than in non HIV

Numerical modeling of the 1840s major eruption of η Carinae as an explosion

NASA Astrophysics Data System (ADS)

González, Ricardo F.

2018-01-01

In this paper, new two-dimensional hydrodynamical simulations of η Car's nebulae are performed. In the 1840s, the massive star η Car suffered a major eruption that resulted in the formation of a bipolar structure, which is commonly known as the large Homunculus. During this event, η Car expelled into the circumstellar material a total mass of 10 M⊙ and released a total energy of Ek 1050 erg over a very short time (≤5 yr). These kinds of explosive events are frequently called supernova impostors due to their resemblance to a type II supernova, but the stars survive the explosion. In the case of η Car, a brief explosion scenario provides a potential explanation for the behavior of the historical light curve of η Car a few years ( 10 yr) after the nineteenth century outburst. Here, such an alternative scenario of an explosion is assumed (instead of a super-Eddington wind) in order to investigate whether an explosive event is also able to explain the shape and kinematics of the large Homunculus. I show that the numerical simulations presented here indeed resemble some of the observed features of the nebula, such as the present-day double-shell structure of the Homunculus, with a thin outer dense shell and a thicker inner layer, as well as thermal instabilities (Rayleigh-Taylor and Kelvin-Helmholtz) along the dense shell that may lead to the current mottled appearance of the large Homunculus. Nonetheless, the explosion model for the 1840s major eruption of η Car is not able to account for the estimated age of the large Homunculus.

Specific antibodies induced by nasally administered 40-kDa outer membrane protein of Porphyromonas gingivalis inhibits coaggregation activity of P. gingivalis.

PubMed

Namikoshi, Jun; Otake, Shigeo; Maeba, Satomi; Hayakawa, Mitsuo; Abiko, Yoshimitsu; Yamamoto, Masafumi

2003-12-12

In this study, we have assessed the efficacy of the 40-kDa outer membrane protein (40k-OMP) of Porphyromonas gingivalis as a nasal vaccine for the prevention of adult periodontitis. Mice nasally immunized with 40k-OMP and cholera toxin as mucosal adjuvant displayed significant levels of 40k-OMP-specific serum IgG1, IgG2b and IgA as well as mucosal IgA antibodies (Abs) in saliva and nasal secretions. Ab-forming cell (AFC) analysis confirmed the antibody titers by detecting high numbers of 40k-OMP-specific AFCs in spleen, salivary glands and nasal passages. Because 40k-OMP-specific IgG inhibited coaggregation of P. gingivalis vesicles and S. gordonii, it may be an important tool for the prevention of adult periodontitis.

Phylogeny of Anophelinae using mitochondrial protein coding genes

PubMed Central

de Oliveira, Tatiane Marques Porangaba; Bergo, Eduardo S.; Conn, Jan E.; Sant’Ana, Denise Cristina; Nagaki, Sandra Sayuri; Nihei, Silvio; Lamas, Carlos Einicker; González, Christian; Moreira, Caio Cesar; Sallum, Maria Anice Mureb

2017-01-01

Malaria is a vector-borne disease that is a great burden on the poorest and most marginalized communities of the tropical and subtropical world. Approximately 41 species of Anopheline mosquitoes can effectively spread species of Plasmodium parasites that cause human malaria. Proposing a natural classification for the subfamily Anophelinae has been a continuous effort, addressed using both morphology and DNA sequence data. The monophyly of the genus Anopheles, and phylogenetic placement of the genus Bironella, subgenera Kerteszia, Lophopodomyia and Stethomyia within the subfamily Anophelinae, remain in question. To understand the classification of Anophelinae, we inferred the phylogeny of all three genera (Anopheles, Bironella, Chagasia) and major subgenera by analysing the amino acid sequences of the 13 protein coding genes of 150 newly sequenced mitochondrial genomes of Anophelinae and 18 newly sequenced Culex species as outgroup taxa, supplemented with 23 mitogenomes from GenBank. Our analyses generally place genus Bironella within the genus Anopheles, which implies that the latter as it is currently defined is not monophyletic. With some inconsistencies, Bironella was placed within the major clade that includes Anopheles, Cellia, Kerteszia, Lophopodomyia, Nyssorhynchus and Stethomyia, which were found to be monophyletic groups within Anophelinae. Our findings provided robust evidence for elevating the monophyletic groupings Kerteszia, Lophopodomyia, Nyssorhynchus and Stethomyia to genus level; genus Anopheles to include subgenera Anopheles, Baimaia, Cellia and Christya; Anopheles parvus to be placed into a new genus; Nyssorhynchus to be elevated to genus level; the genus Nyssorhynchus to include subgenera Myzorhynchella and Nyssorhynchus; Anopheles atacamensis and Anopheles pictipennis to be transferred from subgenus Nyssorhynchus to subgenus Myzorhynchella; and subgenus Nyssorhynchus to encompass the remaining species of Argyritarsis and Albimanus Sections

Was the nineteenth century giant eruption of Eta Carinae a merger event in a triple system?

NASA Astrophysics Data System (ADS)

Portegies Zwart, S. F.; van den Heuvel, E. P. J.

2016-03-01

We discuss the events that led to the giant eruption of Eta Carinae, and find that the mid-nineteenth century (in 1838-1843) giant mass-loss outburst has the characteristics of being produced by the merger event of a massive close binary, triggered by the gravitational interaction with a massive third companion star, which is the current binary companion in the Eta Carinae system. We come to this conclusion by a combination of theoretical arguments supported by computer simulations using the Astrophysical Multipurpose Software Environment. According to this model the ˜90 M⊙ present primary star of the highly eccentric Eta Carinae binary system is the product of this merger, and its ˜30 M⊙ companion originally was the third star in the system. In our model, the Homunculus nebula was produced by an extremely enhanced stellar wind, energized by tidal energy dissipation prior to the merger, which enormously boosted the radiation-driven wind mass-loss. The current orbital plane is then aligned with the equatorial plane of the Homunculus, and the symmetric lobes are roughly aligned with the argument of periastron of the current Eta Carina binary. The merger itself then occurred in 1838, which resulted in a massive asymmetric outflow in the equatorial plane of the Homunculus. The 1843 outburst can in our model be attributed to the subsequent encounter when the companion star (once the outermost star in the triple system) plunges through the bloated envelope of the merger product, once when it passed periastron again. We predict that the system has an excess space velocity of order 50 km s-1 in the equatorial plane of the Homunculus. Our triple model gives a viable explanation for the high runaway velocities typically observed in LBVs.

A Case Study in Astronomical 3D Printing: The Mysterious η Carinae

NASA Astrophysics Data System (ADS)

Madura, Thomas I.

2017-05-01

Three-dimensional (3D) printing moves beyond interactive 3D graphics and provides an excellent tool for both visual and tactile learners, since 3D printing can now easily communicate complex geometries and full color information. Some limitations of interactive 3D graphics are also alleviated by 3D printable models, including issues of limited software support, portability, accessibility, and sustainability. We describe the motivations, methods, and results of our work on using 3D printing (1) to visualize and understand the η Car Homunculus nebula and central binary system and (2) for astronomy outreach and education, specifically, with visually impaired students. One new result we present is the ability to 3D print full-color models of η Car’s colliding stellar winds. We also demonstrate how 3D printing has helped us communicate our improved understanding of the detailed structure of η Car’s Homunculus nebula and central binary colliding stellar winds, and their links to each other. Attached to this article are full-color 3D printable files of both a red-blue Homunculus model and the η Car colliding stellar winds at orbital phase 1.045. 3D printing could prove to be vital to how astronomer’s reach out and share their work with each other, the public, and new audiences.

Ejecta of Eta Carinae: What We Learn about N-Rich Chemistry

NASA Technical Reports Server (NTRS)

Gull, Theodore

2006-01-01

At least one member of the binary system, Eta Carinae, is in the late stages of CNO-cycle. At least ten solar masses of ejecta make up the Homunculus, a neutral bi-polar shell ejected in the 1840s and the Little Homunculus, an internal, ionized bi-polar shell ejected in the 1890s. HST/STIS and VLTAJVES high dispersion spectroscopy revealed absorptions of multiple elements and diatomic molecules in these shells, some, such as V II and Sr II have not been seen previously in the ISM. The skirt region between the bi-lobes includes the very bright Weigelt blobs, within 0.1 to 0.3" of the central source, and the more distant, unusual Strontium Filament, a neutral emission nebula photoexcited by Balmer continuum, but shielded by Fe II from Lyman radiation. The 600+ emission lines are due to metals usually tied up in dust, but underabundances of C and O prevent precipitation as oxides onto the dust grains. Indications are that Ti/Ni is 100X solar, likely due not to nuclear processing, but the very different photo-excitation environments coupled with N-rich, C-, O-poor chemistry. In the Homunculus, level populations of the molecules indicate 60K gas; the metal absorption lines, 760K; that of the Little Homunculus 6400K during the broad spectroscopic maximum, relaxing to 5000K for the few month long minimum. Lyman radiation, including both continuum and Lyman lines, is trapped across periastron. leading to temporary relaxation of the ejecta. These ejecta are a treasure trove of information on material thrown out of massive stars in the CNO-cycle, well before the helium burning phase. Curiously, spectra of three very recent SWIFT GRBs indicate the presence of warm, photoexcited ejecta in the vicinity of the protoGRBs, but obviously of very different abundances. However, the ejecta of Eta Carinae promise to be a nearby example of massive ejecta, the study of which should lead to increased insight of earlier, very distant massive stars.

Eta Carinae: What We have learned recently with HST/STIS, VLT/UVES and VLTI: What We Might Learn with VLT/VLTI across the 2008/9 Minimum

NASA Technical Reports Server (NTRS)

Gull, Theodore R.

2005-01-01

Eta Carinae, the LBV that we have learned to love and hate, has revealed many clues of its character over the past seven years by studies with HST and VLT. Based upon X-Ray, optical and IR observations, Eta Carinae is convincingly a massive binary system that uniquely has major nebular ejecta that are connected with historical outbursts. We have successhlly followed the stellar and nebular changes over the 5.5 year cycle, especially with STIS and RXTE, and across the spectroscopic minimum in 2003.5 with STIS, CHANDRA, RXTE, FUSE, and VLT/UVES. The HST/STIS high spatial resolution, combined with appropriate spectral resolving powers from 1150 to 10300 A, has revealed much about the Central Source and especially the spatially resolved extended stellar atmosphere and the ejecta, known as the Homunculus. Indeed the neutral, dusty outer Homunculus, ejected in the 1840s, envelops the newly discovered ionized Little Homunculus, ejected in the 1890s. In line of sight, multiple hot clumps, both ionized and neutral, are seen in absorption and provide much information on the physical conditions of these massive ejecta. Against the nebular-scattered starlight, wind and nebular absorptions provide views at different angles from line of sight. The VLT/UVES studies from 2002 through 2004 provided very important time-sampled spectra of both the star as seen directly and as seen by the SE lobe viewing the polar region of the star. The VLTI 2.2 micron measures of the central source are consistent with a prolate spheroid with its axis extending along the axis of the Homunculus. This is consistent with the noticeably larger wind mass and higher terminal velocity along the axis of the Homunculus compared to that measured in line of sight at about 45 degrees from the polar axes. We understand the system to be a massive primary with an O or WR companion in a very highly elliptical orbit. The spectroscopic minimum occurs during periastron, when the greatly extended primary atmosphere and

The Time Evolution of Eta Carinae's Colliding Winds

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Madura, T. I.; Grobe, J. H.; Corcoran, M. F.

2011-01-01

We report new HST/STIS observations that map the high-ionization forbidden line emission in the inner arc second of Eta Car, the first that fully image the extended wind-wind interaction region of the massive colliding wind binary. These observations were obtained after the 2009.0 periastron at orbital phases 0.084, 0.163, and 0.323 of the 5.54-year spectroscopic cycle. We analyze the variations in brightness and morphology of the emission, and find that blue-shifted emission (-400 to -200 km/s is symmetric and elongated along the northeast-southwest axis, while the red-shifted emission (+ 100 to +200 km/s) is asymmetric and extends to the north-northwest. Comparison to synthetic images generated from a 3-D dynamical model strengthens the 3-D orbital orientation found by Madura et al. (2011), with an inclination i = 138 deg, argument of periapsis w = 270 deg, and an orbital axis that is aligned at the same P A on the sky as the symmetry axis of the Homunculus, 312 deg. We discuss the potential that these and future mappings have for constraining the stellar parameters of the companion star and the long-term variability of the system. Plain-Language Abstract: With HST, we resolved the interacting winds of the binary, Eta Carinae. With a 3-D model, we find the binary orbit axis is aligned to the Homunculus axis. This suggests a connection between the binary and Homunculus ejection mechanism.

Dissecting a supernova impostor's circumstellar medium: MUSEing about the SHAPE of η Carinae's outer ejecta

NASA Astrophysics Data System (ADS)

Mehner, A.; Steffen, W.; Groh, J. H.; Vogt, F. P. A.; Baade, D.; Boffin, H. M. J.; Davidson, K.; de Wit, W. J.; Humphreys, R. M.; Martayan, C.; Oudmaijer, R. D.; Rivinius, T.; Selman, F.

2016-11-01

Aims: The role of episodic mass loss is one of the outstanding questions in massive star evolution. The structural inhomogeneities and kinematics of their nebulae are tracers of their mass-loss history. We conduct a three-dimensional morpho-kinematic analysis of the ejecta of η Car outside its famous Homunculus nebula. Methods: We carried out the first large-scale integral field unit observations of η Car in the optical, covering a field of view of 1'× 1' centered on the star. Observations with the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope (VLT) reveal the detailed three-dimensional structure of η Car's outer ejecta. Morpho-kinematic modeling of these ejecta is conducted with the code SHAPE. Results: The largest coherent structure in η Car's outer ejecta can be described as a bent cylinder with roughly the same symmetry axis as the Homunculus nebula. This large outer shell is interacting with the surrounding medium, creating soft X-ray emission. Doppler velocities of up to 3000 km s-1 are observed. We establish the shape and extent of the ghost shell in front of the southern Homunculus lobe and confirm that the NN condensation can best be modeled as a bowshock in the orbital/equatorial plane. Conclusions: The SHAPE modeling of the MUSE observations provides a significant gain in the study of the three-dimensional structure of η Car's outer ejecta. Our SHAPE modeling indicates that the kinematics of the outer ejecta measured with MUSE can be described by a spatially coherent structure, and that this structure also correlates with the extended soft X-ray emission associated with the outer debris field. The ghost shell immediately outside the southern Homunculus lobe hints at a sequence of eruptions within the time frame of the Great Eruption from 1837-1858 or possibly a later shock/reverse shock velocity separation. Our 3D morpho-kinematic modeling and the MUSE observations constitute an invaluable dataset to be confronted with future

Is the Ejecta of ETA Carinae Overabundant or Overexcited

NASA Technical Reports Server (NTRS)

Gull, Theodore; Davidson, Kris; Johansson, Sveneric; Damineli, Augusto; Ishibashi, Kaxunori; Corcoran, Michael; Hartman, Henrick; Viera, Gladys; Nielsen, Krister

2003-01-01

The ejecta of Eta Carinae, revealed by HST/STIS, are in a large range of physical conditions. As Eta Carinae undergoes a 5.52 period, changes occur in nebular emission and nebular absorption. "Warm" neutral regions, partially ionized regions, and fully ionized regions undergo significant changes. Over 2000 emission lines, most of Fe-like elements, have been indentified in the Weigelt blobs B and D. Over 500 emission lines have been indentified in the Strontium Filament. An ionized Little Homunculus is nestled within the neutral-shelled Homunculus. In line of sight, over 500 nebular absorption lines have been identified with up to twenty velocity components. STIS is following changes in many nebular emission and absorption lines as Eta Carinae approaches the minimum, predicted to be in June/July 2003, during the General Assembly. Coordinated observations with HST, CHANDRA, RXTE, FUSE, UVES/VLT, Gemini and other observatories are following this minimum.

Excited Ejecta in Light of Sight from Eta Car

NASA Technical Reports Server (NTRS)

Vieira, G.; Gull, T. R.; Danks, A.

2003-01-01

In the NUV spectrum of Eta Car, we have resolved many narrow absorption lines of neutral and singly-ionized elements with the Space Telescope Imaging Spectrograph. We report for the first time the detection of interstellar vanadium in absorption, and many highly-excited absorption lines of Fe, Cr, Ti, Ni, Co, Mn, and Mg. These elements, normally tied up in dust grains in the ISM, are located within wall of the Homunculus within 20,000 A.U. of Eta Car. Stellar radiation and stellar wind are interacting with the wall. Dust is likely being modified and/or destroyed. Previous Homunculus studies have demonstrated that nitrogen is overabundant and that carbon and oxygen emission lines are weak, or non-existent. Are the large column densities of these heavy elements due to abundance effects, excitation mechanisms, or modified grains? We may gain insight as Eta Car goes through its spectroscopic minimum in the summer of 2003.

Eta Carina: What was the Great Eruption in the 19th Century?

NASA Astrophysics Data System (ADS)

Gull, Theodore; Eta Carina Bunch

2018-01-01

In the 1840’s, Eta Carina brightened to rival Sirius in apparent magnitude only to fade to naked-eye visibility for 5 decades, brightened somewhat in the 1890s and faded again until the 1940’s when it began a progressive brightening that continues. Today Eta Carina is a massive binary (100 Mo and 30 Mo) with a 5.54-year period, immersed in a massive (>40Mo) dusty, bipolar nebula. The radiation and kinetic energy of the 1840s event rivals that of a supernova, but the binary survived. While Eta Carina is suggested to be a supernova imposter, most imposters, seen in nearby galaxies, lead to actual supernova events months to years afterwards, yet the binary, Eta Carina, is still with us 170 years after the outburst.With modern observatories we are gaining much insight on the massive binary--followed by many ground-based telescopes, the fossil wind structures--mapped with HST/STIS, the Little Homunculus--discovered with HST/STIS and Homunculus--now being studied with ALMA. 3D models are able to explain much of the structures, but potentially much material remains hidden in the form of molecules on the far side of the Homunculus in the equatorial skirt region, where Herschel observations indicate the bulk of dust-emitting continuum resides.Was there a third star that became a supernova? Did one of the two stars go through a near supernova experience?This poster will summarize observations and modeling of the current system in hopes that theorists will become interested in providing scenarios and models that led to the ejecta and binary we observe today.

Representation of the Speech Effectors in the Human Motor Cortex: Somatotopy or Overlap?

ERIC Educational Resources Information Center

Takai, Osamu; Brown, Steven; Liotti, Mario

2010-01-01

Somatotopy within the orofacial region of the human motor cortex has been a central concept in interpreting the results of neuroimaging and transcranial magnetic stimulation studies of normal and disordered speech. Yet, somatotopy has been challenged by studies showing overlap among the effectors within the homunculus. In order to address this…

MRI correlates of alien leg-like phenomenon in corticobasal degeneration.

PubMed

Hu, William T; Josephs, Keith A; Ahlskog, J Eric; Shin, Cheolsu; Boeve, Bradley F; Witte, Robert J

2005-07-01

We describe the clinical and neuroradiologic correlates in two patients with the clinical picture of CBD and alien leg phenomena. The MRI brain scan in both had unique focal abnormalities in the corresponding leg area of the homunculus that may be the substrate for the alien limb features. Copyright 2005 Movement Disorder Society.

Measuring Changes in the Distribution, Mass, and Composition of Dust in the Eruptive LBV Eta Carinae

NASA Astrophysics Data System (ADS)

Morris, Patrick

The luminous, massive binary system eta Carinae is both one of the nearest and most unstable objects in a class of evolved massive stars, near the end of its lifetime before expected destruction in a supernova. It experienced a major outburst in 1843, producing the well-known Homunculus nebula, containing some 15 to 40 Msun in warm ( 170 K) and cool (90-110 K) dust and gas, according to mid-infrared ISO spectroscopy. The location of these thermal components has been uncertain due to large apertures. In Cycle 3 we were approved for 10 hours to use the FORCAST imager with long wavelength filters to better locate and estimate the mass in thermal components of this material that may be resolved, constraining it to the interior regions or bipolar lobes of the Homunculus nebula, or in outer ejecta that would support the hypothesis of a major event prior to the 1843 eruption. About 40% of the program is planned for completion in Cycle 4. We are proposing in Cycle 5 to carry out spectroscopy of the dusty Homunculus nebula at two positions and one reference sky position, using the FORCAST grism with all four filters, in order to characterize changes in mass, composition, and grain properties of especially the cool dust containing >80% of the dust mass, and comparing the results to our spatially integrated ISO spectra taken in 1996/1997, and to 8-13.5 micron data of the warm dust obtained with VLTI/MIDI in 2002/2003 by Chesneau et al. (2005) . These changes may result from the ongoing production of dust in the colliding winds of the 5.5 year period eccentric binary system, particularly during periastron which has occurred three times since 1997. The proposed spectroscopy of especially the cool dust cannot be accomplished from the ground.

Eta Carinae: A Box of Puzzles...Some Solved, Others Await

NASA Technical Reports Server (NTRS)

Gull, Theodore

2010-01-01

In the l840's, Eta Carinae brightened to rival Sirius, then faded. Today we see a marginally naked-eye binary with an expanding, very dusty bipolar Homunculus. The energetics of the ejected mass (>l2 to 40 solar masses at 500-700 km/s plus outer bullets/strings up to 3000 km/s} approach that of a supernova. Extragalactic SN surveys detect near-supernovae thought to be like the Great Eruption of the 1840's. Eta Carinae presents an abundance of puzzles: rich in N, but 1/100th the solar C and O abundances; Ti, V, Sr, Sc persist in atomic states.... yet an abundance of molecules and dust exists in the Homunculus. How did molecules and dust form with low C and O? A near supernova occurred in the l840m, yet both binary companions, with total mass > 120 solar masses, survive in a very eccentric orbit. What is the near future of this system: a GRB? a SN? or just two WR stars that ultimately become two SNs? These and other puzzles will be presented

Eta Carinae: Viewed from Multiple Vantage Points

NASA Technical Reports Server (NTRS)

Gull, Theodore

2007-01-01

The central source of Eta Carinae and its ejecta is a massive binary system buried within a massive interacting wind structure which envelops the two stars. However the hot, less massive companion blows a small cavity in the very massive primary wind, plus ionizes a portion of the massive wind just beyond the wind-wind boundary. We gain insight on this complex structure by examining the spatially-resolved Space Telescope Imaging Spectrograph (STIS) spectra of the central source (0.1") with the wind structure which extends out to nearly an arcsecond (2300AU) and the wind-blown boundaries, plus the ejecta of the Little Homunculus. Moreover, the spatially resolved Very Large Telescope/UltraViolet Echelle Spectrograph (VLT/UVES) stellar spectrum (one arcsecond) and spatially sampled spectra across the foreground lobe of the Homunculus provide us vantage points from different angles relative to line of sight. Examples of wind line profiles of Fe II, and the.highly excited [Fe III], [Ne III], [Ar III] and [S III)], plus other lines will be presented.

The dynamics of interaction of reflexive subjects operating with the two-valued versus many-valued logic.

PubMed

Sawa, Koji; Igamberdiev, Abir U

2017-12-01

In this paper we aim to approach a model of interacting subjects with the opposite types of reflexion that belong to the Western (W) and Eastern (E) reflexive modes according to Vladimir Lefebvre (1992). The model represents an expansion of the previously developed model of the Double Homunculus (Sawa and Igamberdiev, 2016) that describes reflexive agents as holding "the image of the self in the image of the self". A dialogue model between the two homunculus agents estimating their own reflexion in the opposite ways (generating the two-valued versus many-valued logic and loosely approximated as belonging to the W and E Lefebvre's types) is evolved. At the same time, the argument also unveils the relationship between a difference equation which is the key notion of the model and an emergence of logic. This can be a powerful tool for describing intercommunication of reflexive agents in the social environment as well as interactions between the entire social systems of different types. Copyright © 2017 Elsevier Ltd. All rights reserved.

3D Modeling of Forbidden Line Emission in the Binary Wind Interaction Region of Eta Carinae

NASA Technical Reports Server (NTRS)

Madura, Thomas; Gull, T. R.; Owocki, S.; Okazaki, A. T.; Russell, C. M. P.

2010-01-01

We present recent work using three-dimensional (3D) Smoothed Particle Hydrodynamics (SPH) simulations to model the high ([Fe III], [Ar III], [Ne III] and [S III]) and low ([Fe II], [Ni II]) ionization forbidden emission lines observed in Eta Carinae using the HST/STIS. These structures are interpreted as the time-averaged, outer extensions of the primary wind and the wind-wind interaction region directly excited by the FUV of the hot companion star of this massive binary system. We discuss how analyzing the results of the 3D SPH simulations and synthetic slit spectra and comparing them to the spectra obtained with the HST/STIS helps us determine the absolute orientation of the binary orbit and helps remove the degeneracy inherent to models based solely on the observed RXTE X-ray light curve. A key point of this work is that spatially resolved observations like those with HST/STIS and comparison to 3D models are necessary to determine the alignment or misalignment of the orbital angular momentum axis with the Homunculus, or correspondingly, the alignment of the orbital plane with the Homunculus skirt.

The Strontium Filament within the Homunculus of Eta Carinae

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Hartman, H.; Zethson, T.; Johansson, S.; Ishibashi, K.; Davidson, K.; Fisher, Richard R. (Technical Monitor)

2001-01-01

During a series of HST/STIS observations of Eta Carinae and associated ejecta, we noticed a peculiar emission filament located a few arcseconds north of the central source. While bright in nebular standards, it is submerged in a sea of scattered starlight until moderately high dispersion, long-slit spectroscopy with the STIS (R- 8000) brings the emission lines out. The initial spectrum, centered on 6768A with the STIS G750M grating, led to identification of twenty lines from singly-Ionized species including [Sr II], [Fe II], [Ti II], [Ni II], [Mn II], and [Co II] (Zethson, etal., 2001, AJ 122,322). No Balmer emission is detected from this filament and the Fe II 2507,9 lines, known to be pumped by Lyman alpha radiation in other regions near the central source, are not detected. Followup observations have led to detection of hundreds more emission lines from iron group elements in neutral and singly-ionized states. Thus far all are excited by less than 10 eV. This peculiar nebular emission is thought to be due to very intense stellar radiation, stripped of uv flux shortward of Lyman alpha, bathing a neutral structure. We are systematically identifying the many lines (over 90% identified) and measuring line intensities that will then be modeled to determine excitation mechanisms, temperature and density. Two [Sr II] and two Sr II lines have now been measured. Bautista, etal. (in preparation) have modeled the strontium flux ratios and find that large radiation fluxes and/or high strontium abundances may account for the detected emission. These observations were supported by STIS GTO funding and GO funding through the STScI

Mosquito (Diptera: Culicidae) assemblages associated with Nidularium and Vriesea bromeliads in Serra do Mar, Atlantic Forest, Brazil

PubMed Central

2012-01-01

Background The most substantial and best preserved area of Atlantic Forest is within the biogeographical sub-region of Serra do Mar. The topographic complexity of the region creates a diverse array of microclimates, which can affect species distribution and diversity inside the forest. Given that Atlantic Forest includes highly heterogeneous environments, a diverse and medically important Culicidae assemblage, and possible species co-occurrence, we evaluated mosquito assemblages from bromeliad phytotelmata in Serra do Mar (southeastern Brazil). Methods Larvae and pupae were collected monthly from Nidularium and Vriesea bromeliads between July 2008 and June 2009. Collection sites were divided into landscape categories (lowland, hillslope and hilltop) based on elevation and slope. Correlations between bromeliad mosquito assemblage and environmental variables were assessed using multivariate redundancy analysis. Differences in species diversity between bromeliads within each category of elevation were explored using the Renyi diversity index. Univariate binary logistic regression analyses were used to assess species co-occurrence. Results A total of 2,024 mosquitoes belonging to 22 species were collected. Landscape categories (pseudo-F value = 1.89, p = 0.04), bromeliad water volume (pseudo-F = 2.99, p = 0.03) and bromeliad fullness (Pseudo-F = 4.47, p < 0.01) influenced mosquito assemblage structure. Renyi diversity index show that lowland possesses the highest diversity indices. The presence of An. homunculus was associated with Cx. ocellatus and the presence of An. cruzii was associated with Cx. neglectus, Cx. inimitabilis fuscatus and Cx. worontzowi. Anopheles cruzii and An. homunculus were taken from the same bromeliad, however, the co-occurrence between those two species was not statistically significant. Conclusions One of the main findings of our study was that differences in species among mosquito assemblages were influenced by landscape characteristics. The

Mosquito (Diptera: Culicidae) assemblages associated with Nidularium and Vriesea bromeliads in Serra do Mar, Atlantic Forest, Brazil.

PubMed

Marques, Tatiani C; Bourke, Brian P; Laporta, Gabriel Z; Sallum, Maria Anice Mureb

2012-02-16

The most substantial and best preserved area of Atlantic Forest is within the biogeographical sub-region of Serra do Mar. The topographic complexity of the region creates a diverse array of microclimates, which can affect species distribution and diversity inside the forest. Given that Atlantic Forest includes highly heterogeneous environments, a diverse and medically important Culicidae assemblage, and possible species co-occurrence, we evaluated mosquito assemblages from bromeliad phytotelmata in Serra do Mar (southeastern Brazil). Larvae and pupae were collected monthly from Nidularium and Vriesea bromeliads between July 2008 and June 2009. Collection sites were divided into landscape categories (lowland, hillslope and hilltop) based on elevation and slope. Correlations between bromeliad mosquito assemblage and environmental variables were assessed using multivariate redundancy analysis. Differences in species diversity between bromeliads within each category of elevation were explored using the Renyi diversity index. Univariate binary logistic regression analyses were used to assess species co-occurrence. A total of 2,024 mosquitoes belonging to 22 species were collected. Landscape categories (pseudo-F value = 1.89, p = 0.04), bromeliad water volume (pseudo-F = 2.99, p = 0.03) and bromeliad fullness (Pseudo-F = 4.47, p < 0.01) influenced mosquito assemblage structure. Renyi diversity index show that lowland possesses the highest diversity indices. The presence of An. homunculus was associated with Cx. ocellatus and the presence of An. cruzii was associated with Cx. neglectus, Cx. inimitabilis fuscatus and Cx. worontzowi. Anopheles cruzii and An. homunculus were taken from the same bromeliad, however, the co-occurrence between those two species was not statistically significant. One of the main findings of our study was that differences in species among mosquito assemblages were influenced by landscape characteristics. The bromeliad factor that influenced

CRISPR/Cas9-Mediated Insertion of loxP Sites in the Mouse Dock7 Gene Provides an Effective Alternative to Use of Targeted Embryonic Stem Cells.

PubMed

Bishop, Kathleen A; Harrington, Anne; Kouranova, Evguenia; Weinstein, Edward J; Rosen, Clifford J; Cui, Xiaoxia; Liaw, Lucy

2016-07-07

Targeted gene mutation in the mouse is a primary strategy to understand gene function and relation to phenotype. The Knockout Mouse Project (KOMP) had an initial goal to develop a public resource of mouse embryonic stem (ES) cell clones that carry null mutations in all genes. Indeed, many useful novel mouse models have been generated from publically accessible targeted mouse ES cell lines. However, there are limitations, including incorrect targeting or cassette structure, and difficulties with germline transmission of the allele from chimeric mice. In our experience, using a small sample of targeted ES cell clones, we were successful ∼50% of the time in generating germline transmission of a correctly targeted allele. With the advent of CRISPR/Cas9 as a mouse genome modification tool, we assessed the efficiency of creating a conditional targeted allele in one gene, dedicator of cytokinesis 7 (Dock7), for which we were unsuccessful in generating a null allele using a KOMP targeted ES cell clone. The strategy was to insert loxP sites to flank either exons 3 and 4, or exons 3 through 7. By coinjecting Cas9 mRNA, validated sgRNAs, and oligonucleotide donors into fertilized eggs from C57BL/6J mice, we obtained a variety of alleles, including mice homozygous for the null alleles mediated by nonhomologous end joining, alleles with one of the two desired loxP sites, and correctly targeted alleles with both loxP sites. We also found frequent mutations in the inserted loxP sequence, which is partly attributable to the heterogeneity in the original oligonucleotide preparation. Copyright © 2016 Bishop et al.

The 3D Structure of Eta Carinae's Nebula: A Definitive Picture from High-Dispersion Near-IR Spectra

NASA Technical Reports Server (NTRS)

Smith, N.

2006-01-01

High resolution long-slit spectra obtained with the Phoenix spectrograph on Gemini South provide our most accurate probe of the 3D structure of the Homunculus Nebula around Eta Carinae. Emission from molecular hydrogen at 2.122 microns traces a very thin outer skin, which contains the vast majority of the more than 10 solar masses of material in the nebula. This emission, in turn, yields our first definitive picture of the exact shape of the nebula, plus the latitude dependence of the mass-loss rate, speed, kinetic energy, shell thickness, and other properties associated with Eta Car's 19th century explosion. This will be critical for testing any models for the outburst mechanism. A preliminary analysis suggests that explosion from a critically rotating star was the dominant mechanism that gave rise to both the bipolar shape of the nebula and the production of its equatorial disk. [Fe II] emission in the near IR traces a geometrically thicker but less massive shell found on the inner surface of the H2 skin --- this is either a reverse shock that decelerates Eta Car's wind or a warm PDR. [Fe Ill emission also clarifies the structure of an inner "Little Homunculus" seen previously in HST/STlS spectra. Comparing these two tracers of cool molecular gas and warm partially-ionized gas resolves some significant confusion about the complex structure noted in previous studies.

Eta Car: The Good, the Bad and the Ugly of Nebular and Stellar Confusion

NASA Technical Reports Server (NTRS)

Gull, T.R.; Sonneborn, G.; Jensen, A.G.; Nielsen, K.E.; Vieira Kover, G.; Hillier, D.J.

2008-01-01

Observations in the far-UV provide a unique opportunity to investigate the very massive star Eta Car and its hot binary companion, Eta Car B. Eta Car was observed with FUSE over a large portion of the 5.54 year spectroscopic period before and after the 2003.5 minimum. The observed spectrum is defined by strong stellar wind signatures, primarily from Eta Car A, complicated by the strong absorptions of the ejecta surrounding Eta Car plus interstellar absorption. The Homunculus and Little Homunculus are massive bipolar ejecta historically associable with LBV outbursts in the 1840s and the 1890s and are linked to absorptions at -513 and -146 km/s, respectively. The FUSE spectra are confused by the extended nebulosity and thermal drifting of the FUSE co-pointed instruments. Interpretation is further complicated by two B-stars sufficiently close to h Car to be included most of the time in the large FUSE aperture. Followup observations partially succeeded in obtaining spectra of at least one of these B-stars through the smaller apertures, allowing potential separation of the B-star contributions and h Car. A complete analysis of all available spectra is currently underway. Our ultimate goals are to directly detect the hot secondary star if possible with FUSE and to identify the absorption contributions to the overall spectrum especially of the stellar members and the massive ejecta.

Constraining the Properties of the Eta Carinae System via 3-D SPH Models of Space-Based Observations: The Absolute Orientation of the Binary Orbit

NASA Technical Reports Server (NTRS)

Madura, Thomas I.; Gull, Theodore R.; Owocki, Stanley P.; Okazaki, Atsuo T.; Russell, Christopher M. P.

2011-01-01

The extremely massive (> 90 Stellar Mass) and luminous (= 5 x 10(exp 6) Stellar Luminosity) star Eta Carinae, with its spectacular bipolar "Homunculus" nebula, comprises one of the most remarkable and intensely observed stellar systems in the Galaxy. However, many of its underlying physical parameters remain unknown. Multiwavelength variations observed to occur every 5.54 years are interpreted as being due to the collision of a massive wind from the primary star with the fast, less dense wind of a hot companion star in a highly elliptical (e approx. 0.9) orbit. Using three-dimensional (3-D) Smoothed Particle Hydrodynamics (SPH) simulations of the binary wind-wind collision, together with radiative transfer codes, we compute synthetic spectral images of [Fe III] emission line structures and compare them to existing Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) observations. We are thus able, for the first time, to tightly constrain the absolute orientation of the binary orbit on the sky. An orbit with an inclination of approx. 40deg, an argument of periapsis omega approx. 255deg, and a projected orbital axis with a position angle of approx. 312deg east of north provides the best fit to the observations, implying that the orbital axis is closely aligned in 3-D space with the Homunculus symmetry axis, and that the companion star orbits clockwise on the sky relative to the primary.

Bottom-Up Influences on Voluntary Task Switching: The Elusive Homunculus Escapes

ERIC Educational Resources Information Center

Yeung, Nick

2010-01-01

Voluntary action can be studied by giving participants free choice over which task to perform in response to each presented stimulus. In such experiments, performance costs are observed when participants choose to switch tasks from the previous trial. It has been proposed that these costs primarily index the time-consuming operation of top-down…

Constraining the Properties of the Eta Carinae System via 3-D SPH Models of Space-Based Observations: The Absolute Orientation of the Binary Orbit

NASA Technical Reports Server (NTRS)

Madura, Thomas I.; Gull, Theodore R.; Owocki, Stanley P.; Okazaki, Atsuo T.; Russell, Christopher M. P.

2010-01-01

The extremely massive (> 90 Solar Mass) and luminous (= 5 x 10(exp 6) Solar Luminosity) star Eta Carinae, with its spectacular bipolar "Homunculus" nebula, comprises one of the most remarkable and intensely observed stellar systems in the galaxy. However, many of its underlying physical parameters remain a mystery. Multiwavelength variations observed to occur every 5.54 years are interpreted as being due to the collision of a massive wind from the primary star with the fast, less dense wind of a hot companion star in a highly elliptical (e approx. 0.9) orbit. Using three-dimensional (3-D) Smoothed Particle Hydrodynamics (SPH) simulations of the binary wind-wind collision in Eta Car, together with radiative transfer codes, we compute synthetic spectral images of [Fe III] emission line structures and compare them to existing Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) observations. We are thus able, for the first time, to constrain the absolute orientation of the binary orbit on the sky. An orbit with an inclination of i approx. 40deg, an argument of periapsis omega approx. 255deg, and a projected orbital axis with a position angle of approx. 312deg east of north provides the best fit to the observations, implying that the orbital axis is closely aligned in 3-1) space with the Homunculus symmetry axis, and that the companion star orbits clockwise on the sky relative to the primary.

Women's clitoris, vagina and cervix mapped on the sensory cortex: fMRI evidence

PubMed Central

Komisaruk, Barry R.; Wise, Nan; Frangos, Eleni; Liu, Wen-Ching; Allen, Kachina; Brody, Stuart

2011-01-01

Introduction The projection of vagina, uterine cervix, and nipple to the sensory cortex in humans has not been reported. Aims To map the sensory cortical fields of the clitoris, vagina, cervix and nipple, toward an elucidation of the neural systems underlying sexual response. Methods Using functional Magnetic Resonance Imaging (fMRI) we mapped sensory cortical responses to clitoral, vaginal, cervical, and nipple self-stimulation. For points of reference on the homunculus, we also mapped responses to the thumb and great toe (hallux) stimulation. Main Outcome Measures fMRI of brain regions activated by the various sensory stimuli. Results Clitoral, vaginal, and cervical self-stimulation activate differentiable sensory cortical regions, all clustered in the medial cortex (medial paracentral lobule). Nipple self-stimulation activated the genital sensory cortex (as well as the thoracic) region of the homuncular map. Conclusion The genital sensory cortex, identified in the classical Penfield homunculus based on electrical stimulation of the brain only in men, was confirmed for the first time in the literature by the present study in women, applying clitoral, vaginal, and cervical self-stimulation, and observing their regional brain responses using fMRI. Vaginal, clitoral, and cervical regions of activation were differentiable, consistent with innervation by different afferent nerves and different behavioral correlates. Activation of the genital sensory cortex by nipple self-stimulation was unexpected, but suggests a neurological basis for women’s reports of its erotogenic quality. PMID:21797981

The ``Ghost Shell'': Discovery of the Forward Shock from Colliding Winds about Eta Carinae

NASA Astrophysics Data System (ADS)

Dorland, B. N.; Currie, D. G.; Kaufer, A.; Bacciotti, F.

2003-01-01

We report on the newly discovered ``Ghost Shell'' around eta Carinae. We have detected a high-velocity ( ~ - 850 km /s), spatially extended, narrow emission feature lying in front of the southeast lobe of eta Carinae's homunculus. This feature has the speed of a high-velocity shock but the spectrum of a low-velocity shock. We propose that the Ghost Shell is the forward shock between the fast stellar wind of the great eruption of 1842 and the older, slow, massive wind. This discovery is described in more detail in Currie, Dorland, & Kaufer (2002).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prieto, J. L.; Knapp, G. R.; Rest, A.

We present follow-up optical imaging and spectroscopy of one of the light echoes of η Carinae's nineteenth century Great Eruption discovered by Rest et al. By obtaining images and spectra at the same light echo position between 2011 and 2014, we follow the evolution of the Great Eruption on a 3 yr timescale. We find remarkable changes in the photometric and spectroscopic evolution of the echo light. The i-band light curve shows a decline of ∼0.9 mag in ∼1 yr after the peak observed in early 2011 and a flattening at later times. The spectra show a pure-absorption early G-type stellar spectrummore » at peak, but a few months after peak the lines of the Ca II triplet develop strong P-Cygni profiles and we see the appearance of [Ca II] 7291, 7324 doublet in emission. These emission features and their evolution in time resemble those observed in the spectra of some Type IIn supernovae and supernova impostors. Most surprisingly, starting ∼300 days after peak brightness, the spectra show strong molecular transitions of CN at ≳ 6800 Å. The appearance of these CN features can be explained if the ejecta are strongly nitrogen enhanced, as is observed in modern spectroscopic studies of the bipolar Homunculus nebula. Given the spectroscopic evolution of the light echo, velocities of the main features, and detection of strong CN, we are likely seeing ejecta that contributes directly to the Homunculus nebula.« less

MUSEing about the SHAPE of eta Car's outer ejecta

NASA Astrophysics Data System (ADS)

Mehner, A.; Steffen, W.; Groh, J.; Vogt, F. P. A.; Baade, D.; Boffin, H. M. J.; de Wit, W. J.; Oudmaijer, R. D.; Rivinius, T.; Selman, F.

2017-11-01

The role of episodic mass loss in evolved massive stars is one of the outstanding questions in stellar evolution theory. Integral field spectroscopy of nebulae around massive stars provide information on their recent mass-loss history. η Car is one of the most massive evolved stars and is surrounded by a complex circumstellar environment. We have conducted a three-dimensional morpho-kinematic analysis of η Car's ejecta outside its famous Homunculus nebula. SHAPE modelling of VLT MUSE data establish unequivocally the spatial cohesion of the outer ejecta and the correlation of ejecta with the soft X-ray emission.

Why do primordial germ cells migrate through an embryo and what does it mean for biological evolution?

PubMed

Olovnikov, A M

2013-10-01

An explanation of the role of primordial germ cell (PGC) migration during embryogenesis is proposed. According to the hypothesis, various PGCs during their migrations through an early embryo are contacting with anlagen of organs and acquiring nonidentical organ specificities. An individual PGC gets such an organ specificity, which corresponds to specificity of the first anlage with which this PGC has the first contact. As a result, the cellular descendants of PGCs (oocytes or spermatocytes) will express nonidentical organ-specific receptors, hence becoming functionally heterogeneous. Therefore, each clone of germ cells becomes capable of recognizing specifically the molecular signals that correspond only to "its" organ of the body. Such signals are produced by the body's organ when it functions in an extreme mode. Signals from the "exercising" organ of the body are delivered to the gonad only via the brain retransmitter, which is composed of neurons grouped as virtual organs of a homunculus. Homunculi are so-called somatotopic maps of the skeletomotor and other parts of the body represented in the brain. Signals, as complexes of regulatory RNAs and proteins, are transported from the "exercising" organ of the body to the corresponding virtual organ of the homunculus where they are processed and then forwarded to the gonad. The organ-specific signal will be selectively recognized by certain gametocytes according to their organ specificity, and then it will initiate the directed epimutation in the gametocyte genome. The nonrandomness of the gene order in chromosomes, that is the synteny and genetic map, is controlled by the so-called creatron that consolidates the soma and germline into a united system, providing the possibility of evolutionary responses of an organism to environmental influences.

Latitude-Dependent Effects in the Stellar Wind of Eta Carinae

NASA Technical Reports Server (NTRS)

Smith, Nathan; Davidson, Kris; Gull, Theodore R.; Ishibashi, Kazunori; Hillier, D. John

2002-01-01

The Homunculus reflection nebula around eta Carinae provides the rare opportunity to observe the spectrum of a star from more than one direction. In the case of eta Car, the nebula's geometry is known well enough to infer how wind profiles vary with latitude. We present STIS spectra of several positions in the Homunculus, showing directly that eta Car has an aspherical and axisymmetric stellar wind. P Cygni absorption in Balmer lines depends on latitude, with relatively high velocities and strong absorption near the polar axis. Stronger absorption at high latitudes is surprising, and it suggests higher mass flux toward the poles, perhaps resulting from equatorial gravity darkening on a rotating star. Reflected profiles of He I lines are more puzzling, and offer clues to eta Car's wind geometry and ionization structure. During eta Car's high-excitation state in March 2000, the wind had a fast, dense polar wind, with higher ionization at low latitudes. Older STIS data obtained since 1998 reveal that this global stellar-wind geometry changes during eta Car's 5.5 year cycle, and may suggest that this star s spectroscopic events are shell ejections. Whether or not a companion star triggers these outbursts remains ambiguous. The most dramatic changes in the wind occur at low latitudes, while the dense polar wind remains relatively undisturbed during an event. The apparent stability of the polar wind also supports the inferred bipolar geometry. The wind geometry and its variability have critical implications for understanding the 5.5 year cycle and long-term variability, but do not provide a clear alternative to the binary hypothesis for generating eta Car s X-rays.

Elemental and Molecular Relative Abundances in the Ejecta of Eta Carinae

NASA Technical Reports Server (NTRS)

Kober, G. V.; Gull, T. R.; Nielsen, K.; Bruhweiler, F.; Verner, K.; Stahl, O.; Weis, K.; Bomans, D.

2006-01-01

We are measuring relative elemental abundances for the ejecta in the line of sight from Eta Carinae using high dispersion spectroscopy with the HST/STIS and the VLT/UVES. While multiple velocity components have been identified, we focus on the -513 and -146 km/s components originating from the Homunculus and the Little Homunculus. Complicating factors are the complex nebular structures in the immediate vicinity of the bright, massive star: the very bright emission structures, Weigelt blobs B, C and D, the broad, clumpy structures of the extended wind apparently not photoionized by Eta Car B, and general scattered starlight from the extended wind and the dusty core of the circumstellar material. We have used the 3050 to 3160A region of overlap between STIS and UVES to intercompare equivalent widths of absorption lines to estimate the 'contributing factor', namely the amount of light originating from the star compared to nebular structures. While the extracted STIS spectra are from 0.1" wide aperture, the UVES spectra are limited by the 1" seeing conditions. Curiously we find that the scattering contribution in the UVES spectra changes with time, apparently with orbital phase of the 5.54-year period. This indicates that the dust may be modified by changes in the central source with phase. The noticeable drop in scattered light appears to occur about 1.7 years (phase 0.35) after the spectroscopic minimum. Relative abundances of iron peak elements and some molecules will be estimated. Observations in this study were accomplished with HST through STSci and with VLT through ESO and funded under STIS GTO resources.

3D Printing Meets Astrophysics: A New Way to Visualize and Communicate Science

NASA Astrophysics Data System (ADS)

Madura, Thomas Ignatius; Steffen, Wolfgang; Clementel, Nicola; Gull, Theodore R.

2015-08-01

3D printing has the potential to improve the astronomy community’s ability to visualize, understand, interpret, and communicate important scientific results. I summarize recent efforts to use 3D printing to understand in detail the 3D structure of a complex astrophysical system, the supermassive binary star Eta Carinae and its surrounding bipolar ‘Homunculus’ nebula. Using mapping observations of molecular hydrogen line emission obtained with the ESO Very Large Telescope, we obtained a full 3D model of the Homunculus, allowing us to 3D print, for the first time, a detailed replica of a nebula (Steffen et al. 2014, MNRAS, 442, 3316). I also present 3D prints of output from supercomputer simulations of the colliding stellar winds in the highly eccentric binary located near the center of the Homunculus (Madura et al. 2015, arXiv:1503.00716). These 3D prints, the first of their kind, reveal previously unknown ‘finger-like’ structures at orbital phases shortly after periastron (when the two stars are closest to each other) that protrude outward from the spiral wind-wind collision region. The results of both efforts have received significant media attention in recent months, including two NASA press releases (http://www.nasa.gov/content/goddard/astronomers-bring-the-third-dimension-to-a-doomed-stars-outburst/ and http://www.nasa.gov/content/goddard/nasa-observatories-take-an-unprecedented-look-into-superstar-eta-carinae/), demonstrating the potential of using 3D printing for astronomy outreach and education. Perhaps more importantly, 3D printing makes it possible to bring the wonders of astronomy to new, often neglected, audiences, i.e. the blind and visually impaired.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abraham, Zulema; Beaklini, Pedro P. B.; Falceta-Gonçalves, Diego, E-mail: zulema.abraham@iag.usp.br

We report observations of η Carinae obtained with ALMA in the continuum of 100, 230, 280, and 660 GHz in 2012 November, with a resolution that varied from 2.''88 to 0.''45 for the lower and higher frequencies, respectively. The source is not resolved, even at the highest frequency; its spectrum is characteristic of thermal bremsstrahlung of a compact source, but different from the spectrum of optically thin wind. The recombination lines H42α, He42α, H40α, He40α, H50β, H28α, He28α, H21α, and He21α were also detected, and their intensities reveal non-local thermodynamic equilibrium effects. We found that the line profiles could onlymore » be fit by an expanding shell of dense and ionized gas, which produces a slow shock in the surroundings of η Carinae. Combined with fittings to the continuum, we were able to constrain the shell size, radius, density, temperature, and velocity. The detection of the He recombination lines is compatible with the high-temperature gas and requires a high-energy ionizing photon flux, which must be provided by the companion star. The mass-loss rate and wind velocity, necessary to explain the formation of the shell, are compatible with an luminous blue variable eruption. The position, velocity, and physical parameters of the shell coincide with those of the Weigelt blobs. The dynamics found for the expanding shell correspond to matter ejected by η Carinae in 1941 in an event similar to that which formed the Little Homunculus; for that reason, we called the new ejecta the 'Baby Homunculus'.« less

Physiology and immunology of the cholinergic antiinflammatory pathway

PubMed Central

Tracey, Kevin J.

2007-01-01

Cytokine production by the immune system contributes importantly to both health and disease. The nervous system, via an inflammatory reflex of the vagus nerve, can inhibit cytokine release and thereby prevent tissue injury and death. The efferent neural signaling pathway is termed the cholinergic antiinflammatory pathway. Cholinergic agonists inhibit cytokine synthesis and protect against cytokine-mediated diseases. Stimulation of the vagus nerve prevents the damaging effects of cytokine release in experimental sepsis, endotoxemia, ischemia/reperfusion injury, hemorrhagic shock, arthritis, and other inflammatory syndromes. Herein is a review of this physiological, functional anatomical mechanism for neurological regulation of cytokine-dependent disease that begins to define an immunological homunculus. PMID:17273548

HST update - Science amid setbacks

NASA Astrophysics Data System (ADS)

Fienberg, Richard T.

1991-09-01

Recent data obtained from the Hubble Space Telescope (HST) are presented that indicate that the mission of the beleagered telescope has reached a turning point. Among these observations is a spectrogram revealing the complex dynamic structure of the Beta Pictoris's gas disk, the Lyman-alpha lines from clouds of cool hydrogen atoms in the Milky Way, the UV spectrum of Chi Lupi, the images of Eta Carinae and the Homunculus nebula ejected by the star during the 1843 outburst, and the structure of energetic jets from active galactic nuclei. The paper discusses corrective measures planned by the NASA and Hubble project astronomers to restore the observatory to near-perfect health.

The perceptual homunculus: the perception of the relative proportions of the human body.

PubMed

Linkenauger, Sally A; Wong, Hong Yu; Geuss, Michael; Stefanucci, Jeanine K; McCulloch, Kathleen C; Bülthoff, Heinrich H; Mohler, Betty J; Proffitt, Dennis R

2015-02-01

Given that observing one's body is ubiquitous in experience, it is natural to assume that people accurately perceive the relative sizes of their body parts. This assumption is mistaken. In a series of studies, we show that there are dramatic systematic distortions in the perception of bodily proportions, as assessed by visual estimation tasks, where participants were asked to compare the lengths of two body parts. These distortions are not evident when participants estimate the extent of a body part relative to a noncorporeal object or when asked to estimate noncorporal objects that are the same length as their body parts. Our results reveal a radical asymmetry in the perception of corporeal and noncorporeal relative size estimates. Our findings also suggest that people visually perceive the relative size of their body parts as a function of each part's relative tactile sensitivity and physical size.

Scandium and Chromium in the Strontium Filament in the Homunculus of eta Carinae

NASA Technical Reports Server (NTRS)

Gull, T.R.; Melendez, M.; Baustista, M.A.; Ballance, C.; Hartman, H.; Lodders, K.; Martinez, M.

2008-01-01

We continue a systematic study of chemical abundances of the Strontium Filament found in the ejecta of eta Carinae. To this end we interpret the emission spectrum of Sc II and Cr II using multilevel non-LTE models of these systems. Since the atomic data for these ions was previously unavailable, we carry out ab initio calculations of radiative transition rates and electron impact excitation rate coefficients. The observed spectrum is emitted from a mostly neutral region with electron density of the order of 10(exp 7) cm (exp -3) and a temperature between 6000 and 7000 K. These conditions are consistent with our previous diagnostics from [Ni II], [Ti II], amd [Sr II]. The observed spectrum indicates an abundance of Sc relative Ni that more than 40 times the solar values, while the Cr/Ni abundance ratio is roughly solar. Various scenarios of depletion and dust destruction are suggested to explain such abnormal abundances.

Constraining the Absolute Orientation of eta Carinae's Binary Orbit: A 3-D Dynamical Model for the Broad [Fe III] Emission

NASA Technical Reports Server (NTRS)

Madura, T. I.; Gull, T. R.; Owocki, S. P.; Groh, J. H.; Okazaki, A. T.; Russell, C. M. P.

2011-01-01

We present a three-dimensional (3-D) dynamical model for the broad [Fe III] emission observed in Eta Carinae using the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS). This model is based on full 3-D Smoothed Particle Hydrodynamics (SPH) simulations of Eta Car's binary colliding winds. Radiative transfer codes are used to generate synthetic spectro-images of [Fe III] emission line structures at various observed orbital phases and STIS slit position angles (PAs). Through a parameter study that varies the orbital inclination i, the PA(theta) that the orbital plane projection of the line-of-sight makes with the apastron side of the semi-major axis, and the PA on the sky of the orbital axis, we are able, for the first time, to tightly constrain the absolute 3-D orientation of the binary orbit. To simultaneously reproduce the blue-shifted emission arcs observed at orbital phase 0.976, STIS slit PA = +38deg, and the temporal variations in emission seen at negative slit PAs, the binary needs to have an i approx. = 130deg to 145deg, Theta approx. = -15deg to +30deg, and an orbital axis projected on the sky at a P A approx. = 302deg to 327deg east of north. This represents a system with an orbital axis that is closely aligned with the inferred polar axis of the Homunculus nebula, in 3-D. The companion star, Eta(sub B), thus orbits clockwise on the sky and is on the observer's side of the system at apastron. This orientation has important implications for theories for the formation of the Homunculus and helps lay the groundwork for orbital modeling to determine the stellar masses.

Benefit of the doubt: a new view of the role of the prefrontal cortex in executive functioning and decision making

PubMed Central

Asp, Erik; Manzel, Kenneth; Koestner, Bryan; Denburg, Natalie L.; Tranel, Daniel

2013-01-01

The False Tagging Theory (FTT) is a neuroanatomical model of belief and doubt processes that proposes a single, unique function for the prefrontal cortex. Here, we review evidence pertaining to the FTT, the implications of the FTT regarding fractionation of the prefrontal cortex, and the potential benefits of the FTT for new neuroanatomical conceptualizations of executive functions. The FTT provides a parsimonious account that may help overcome theoretical problems with prefrontal cortex mediated executive control such as the homunculus critique. Control in the FTT is examined via the “heuristics and biases” psychological framework for human judgment. The evidence indicates that prefrontal cortex mediated doubting is at the core of executive functioning and may explain some biases of intuitive judgments. PMID:23745103

Molecules and Dust in the Humunculus: Ejecta of Eta Carinae

NASA Technical Reports Server (NTRS)

Gull, T.

2007-01-01

In the 18401s, Eta Carinae ejected massive amounts of nitrogen-rich, carbon- and oxygen-poor material which we see as the hourglass-shaped Homunculus. With the Hubble Space Telescope Imaging Spectrograph, we detected multiple shells in line of sight, the most massive and intriguing being at -513 km/s. Numerous lines of Fe I, Fe II, Ni II, Cr II, Sc II, Sr II, Ti II, V II, etc are identified as well as nearly a thousand H2 lines. The metals have energy level populations consistent with 760K and excited by photons < 8.5eV. We have now identified CH, CH+, OH, and NH at the same velocity, but at 60K, suggesting stratification in the outer ejecta. Analysis of the interior, photoionized emission hourglass structure, known as the Little Homunculus, indicates He, N overabundances and C, 0 underabundances (approximately 1/80 solar). A skirt of neutral and partially ionized gas lies between the lobes of the hourglasses. A portion is seen as the Strontium Filament, a metal- ionized, neutral hydrogen structure. Relative abundances of TiNi are 1/80 solar, CrNi are 1/20 solar. This complex of ejecta appears to have been ejected by a massive star(s) at the end of the hydrogen-burning phase when convection led to overproduction of nitrogen at the expense of carbon and oxygen. Given the underabundances of carbon and oxygen, the chemistry of this system is quite different to the normal ISM, leading to a nitrogen- dominated chemistry. What little C and 0 that is formed is immediately taken up by SiO and Al0 molecules leading to a very different gas/dust ratio than the normal ISM. Dust in this ejecta is abundance, but known to be very grey in character. Observations with HST/STIS and VLT/UVES will be presented along with simple physical models and CLOUD modeling. Insight by the participants will be solicited.

Susceptibility of Peruvian mosquitoes to eastern equine encephalitis virus.

PubMed

Turell, M J; O'Guinn, M L; Dohm, D; Zyzak, M; Watts, D; Fernandez, R; Calampa, C; Klein, T A; Jones, J W

2008-07-01

Mosquitoes were collected in the Amazon Basin, near Iquitos, Peru, and used in experimental studies to evaluate their susceptibility to strains of eastern equine encephalitis virus (EEEV) that were isolated from mosquitoes captured within 20 km of Iquitos. When fed on hamsters or chickens with a viremia of 4105 plaque-forming units (PFU) of EEEV/ml, Culex pedroi Sirivanakarn and Belkin, Aedesfulvus (Wiedemann), Psorophora albigenu (Peryassu), and Psorophoraferox (Von Humboldt) were susceptible to infection, whereas none of the Aedes serratus (Theobald), Culex vomerifer Komp, Culex gnomatos Sallum, Huchings, and Ferreira, Culex portesi Senevet and Abonnenc, or Culex coronator Dyar and Knab became infected, even though they fed on the same viremic blood sources. When these mosquito species fed on animals with viremias of approximately 10(8) PFU/ml, Cx. pedroi, Ae.II (Brazil-Peru) and a lineage III (Argentina-Panama) isolate of EEEV. This study, combined with the repeated isolation of strains of EEEV from Cx. pedroi captured in the Amazon Basin region of Peru, suggests that Cx. pedroi may be the primary enzootic vector of EEEV in this region.

Efficient mouse genome engineering by CRISPR-EZ technology.

PubMed

Modzelewski, Andrew J; Chen, Sean; Willis, Brandon J; Lloyd, K C Kent; Wood, Joshua A; He, Lin

2018-06-01

CRISPR/Cas9 technology has transformed mouse genome editing with unprecedented precision, efficiency, and ease; however, the current practice of microinjecting CRISPR reagents into pronuclear-stage embryos remains rate-limiting. We thus developed CRISPR ribonucleoprotein (RNP) electroporation of zygotes (CRISPR-EZ), an electroporation-based technology that outperforms pronuclear and cytoplasmic microinjection in efficiency, simplicity, cost, and throughput. In C57BL/6J and C57BL/6N mouse strains, CRISPR-EZ achieves 100% delivery of Cas9/single-guide RNA (sgRNA) RNPs, facilitating indel mutations (insertions or deletions), exon deletions, point mutations, and small insertions. In a side-by-side comparison in the high-throughput KnockOut Mouse Project (KOMP) pipeline, CRISPR-EZ consistently outperformed microinjection. Here, we provide an optimized protocol covering sgRNA synthesis, embryo collection, RNP electroporation, mouse generation, and genotyping strategies. Using CRISPR-EZ, a graduate-level researcher with basic embryo-manipulation skills can obtain genetically modified mice in 6 weeks. Altogether, CRISPR-EZ is a simple, economic, efficient, and high-throughput technology that is potentially applicable to other mammalian species.

Still Clever after All These Years: Searching for the Homunculus in Explicitly Cued Task Switching

ERIC Educational Resources Information Center

Logan, Gordon D.; Schneider, Darryl W.; Bundesen, Claus

2007-01-01

Many researchers interpret switch costs in the explicit task-cuing procedure as reflecting endogenous task-set reconfiguration. G. D. Logan and C. Bundesen (2003) challenged this interpretation empirically and theoretically. They argued that many experiments confounded cue encoding benefits with switch costs and they showed that unconfounded…

Representation of the speech effectors in the human motor cortex: somatotopy or overlap?

PubMed

Takai, Osamu; Brown, Steven; Liotti, Mario

2010-04-01

Somatotopy within the orofacial region of the human motor cortex has been a central concept in interpreting the results of neuroimaging and transcranial magnetic stimulation studies of normal and disordered speech. Yet, somatotopy has been challenged by studies showing overlap among the effectors within the homunculus. In order to address this dichotomy, we performed four voxel-based meta-analyses of 54 functional neuroimaging studies of non-speech tasks involving respiration, lip movement, tongue movement, and swallowing, respectively. While the centers of mass of the clusters supported the classic homuncular view of the motor cortex, there was significant variability in the locations of the activation-coordinates among studies, resulting in an overlapping arrangement. This "somatotopy with overlap" might reflect the intrinsic functional interconnectedness of the oral effectors for speech production.

Eta Carinae: A Demanding Mistress

NASA Technical Reports Server (NTRS)

Gull, Theodore

2012-01-01

In the 1840's a southern star, Eta Argus, brightened to rival Sirius for nearly a decade, then faded. Today, we see the Homunculus, an hourglass figure with tutu, a dusty shell exceeding 12 solar masses expanding outward at 500 km/s. Many observers have systematically studied the massive binary total shrouded by interacting winds and its ejecta. More recently 3-D wind-wind collision models have begun to explain the extended structures resolved by Hubble Space Telescope. Now Herschel Space Observatory infrared scans are revealing wind interaction emissions and complex molecules left over from the dust that formed out of gas originally overabundant in nitrogen and greatly-depleted in oxygen and carbon. Many questions remain to be answered: What is the dust that formed in the 1840s event? What are the end states of the two massive companions ... SN, GRB, Hypernova? and When

Ecological characterisation and infection of Anophelines (Diptera: Culicidae) of the Atlantic Forest in the southeast of Brazil over a 10 year period: has the behaviour of the autochthonous malaria vector changed?

PubMed

Buery, Julyana Cerqueira; Rezende, Helder Ricas; Natal, Licia; Silva, Leonardo Santana da; Menezes, Regiane Maria Tironi de; Fux, Blima; Malafronte, Rosely Dos Santos; Falqueto, Aloisio; Cerutti Junior, Crispim

2018-02-01

BACKGROUND In southeastern Brazil, autochthonous cases of malaria can be found near Atlantic Forest fragments. Because the transmission cycle has not been completely clarified, the behaviour of the possible vectors in those regions must be observed. A study concerning the entomological aspects and natural infection of anophelines (Diptera: Culicidae) captured in the municipalities of the mountainous region of Espírito Santo state was performed in 2004 and 2005. Similarly, between 2014 and 2015, 12 monthly collections were performed at the same area of the study mentioned above. METHODS Center for Disease Control (CDC) light traps with CO2 were set in open areas, at the edge and inside of the forest (canopy and ground), whereas Shannon traps were set on the edge. FINDINGS A total of 1,414 anophelines were collected from 13 species. Anopheles (Kerteszia) cruzii Dyar and Knab remained the most frequently captured species in the CDC traps set in the forest canopy, as well as being the vector with the highest prevalence of Plasmodium vivax/simium infection, according to molecular polymerase chain reaction techniques. CONCLUSIONS P. vivax/simium was found only in abdomens of the mosquitoes of the subgenus Nyssorhynchus, weakening the hypothesis that this subgenus also plays a role in malaria transmission in this specific region.

Causal Neuro-immune Relationships at Patients with Chronic Pyelonephritis and Cholecystitis. Correlations between Parameters EEG, HRV and White Blood Cell Count.

PubMed

Kul'chyns'kyi, Andriy B; Kyjenko, Valeriy M; Zukow, Walery; Popovych, Igor L

2017-01-01

We aim to analyze in bounds KJ Tracey's immunological homunculus conception the relationships between parameters of electroencephalogram (EEG) and heart rate variability (HRV), on the one hand, and the parameters of bhite blood cell count, on the other hand. In basal conditions in 23 men, patients with chronic pyelonephritis and cholecystitis in remission, recorded EEG ("NeuroCom Standard", KhAI Medica, Ukraine) and HRV ("Cardiolab+VSR", KhAI Medica, Ukraine). In portion of blood counted up white blood cell count. Revealed that canonical correlation between constellation EEG and HRV parameters form with blood level of leukocytes 0.92 (p<10-5), with relative content in white blood cell count stubnuclear neutrophiles 0.93 (p<10-5), segmentonucleary neutrophiles 0.89 (p<10-3), eosinophiles 0.87 (p=0.003), lymphocytes 0.77 (p<10-3) and with monocytes 0.75 (p=0.003). Parameters of white blood cell count significantly modulated by electrical activity some structures of central and autonomic nervous systems.

[The motor organization of cerebral cortex and the role of the mirror neuron system. Clinical impact for rehabilitation].

PubMed

Sallés, Laia; Gironès, Xavier; Lafuente, José Vicente

2015-01-06

The basic characteristics of Penfield homunculus (somatotopy and unique representation) have been questioned. The existence of a defined anatomo-functional organization within different segments of the same region is controversial. The presence of multiple motor representations in the primary motor area and in the parietal lobe interconnected by parieto-frontal circuits, which are widely overlapped, form a complex organization. Both features support the recovery of functions after brain injury. Regarding the movement organization, it is possible to yield a relevant impact through the understanding of actions and intentions of others, which is mediated by the activation of mirror-neuron systems. The implementation of cognitive functions (observation, image of the action and imitation) from the acute treatment phase allows the activation of motor representations without having to perform the action and it plays an important role in learning motor patterns. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

On the homogeneity and heterogeneity of cortical thickness profiles in Homo sapiens sapiens.

PubMed

Koten, Jan Willem; Schüppen, André; Morozova, Maria; Lehofer, Agnes; Koschutnig, Karl; Wood, Guilherme

2017-12-20

Cortical thickness has been investigated since the beginning of the 20th century, but we do not know how similar the cortical thickness profiles among humans are. In this study, the local similarity of cortical thickness profiles was investigated using sliding window methods. Here, we show that approximately 5% of the cortical thickness profiles are similarly expressed among humans while 45% of the cortical thickness profiles show a high level of heterogeneity. Therefore, heterogeneity is the rule, not the exception. Cortical thickness profiles of somatosensory homunculi and the anterior insula are consistent among humans, while the cortical thickness profiles of the motor homunculus are more variable. Cortical thickness profiles of homunculi that code for muscle position and skin stimulation are highly similar among humans despite large differences in sex, education, and age. This finding suggests that the structure of these cortices remains well preserved over a lifetime. Our observations possibly relativize opinions on cortical plasticity.

Eta Carinae in the Context of the Most Massive Stars

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Damineli, Augusto

2009-01-01

Eta Car, with its historical outbursts, visible ejecta and massive, variable winds, continues to challenge both observers and modelers. In just the past five years over 100 papers have been published on this fascinating object. We now know it to be a massive binary system with a 5.54-year period. In January 2009, Car underwent one of its periodic low-states, associated with periastron passage of the two massive stars. This event was monitored by an intensive multi-wavelength campaign ranging from -rays to radio. A large amount of data was collected to test a number of evolving models including 3-D models of the massive interacting winds. August 2009 was an excellent time for observers and theorists to come together and review the accumulated studies, as have occurred in four meetings since 1998 devoted to Eta Car. Indeed, Car behaved both predictably and unpredictably during this most recent periastron, spurring timely discussions. Coincidently, WR140 also passed through periastron in early 2009. It, too, is a intensively studied massive interacting binary. Comparison of its properties, as well as the properties of other massive stars, with those of Eta Car is very instructive. These well-known examples of evolved massive binary systems provide many clues as to the fate of the most massive stars. What are the effects of the interacting winds, of individual stellar rotation, and of the circumstellar material on what we see as hypernovae/supernovae? We hope to learn. Topics discussed in this 1.5 day Joint Discussion were: Car: the 2009.0 event: Monitoring campaigns in X-rays, optical, radio, interferometry WR140 and HD5980: similarities and differences to Car LBVs and Eta Carinae: What is the relationship? Massive binary systems, wind interactions and 3-D modeling Shapes of the Homunculus & Little Homunculus: what do we learn about mass ejection? Massive stars: the connection to supernovae, hypernovae and gamma ray bursters Where do we go from here? (future

Eta Carinae: Orientation of The Orbital Plane

NASA Technical Reports Server (NTRS)

Gull, T. R.; Nielsen, K. E.; Ivarsson, S.; Corcoran, M. F.; Verner, E.; Hillier, J. D.

2006-01-01

Evidence continues to build that Eta Carinae is a massive binary system with a hidden hot companion in a highly elliptical orbit. We present imaging and spectroscopic evidence that provide clues to the orientation of the orbital plane. The circumstellar ejecta, known as the Homunculus and Little Homunculus, are hourglass-shaped structures, one encapsulated within the other, tilted at about 45 degrees from the sky plane. A disk region lies between the bipolar lobes. Based upon their velocities and proper motions, Weigelt blobs B, C and D, very bright emission clumps 0.1 to 0.3" Northwest from Eta Carinae, lie in the disk. UV flux from the hot companion, Eta Car B, photoexcites the Weigelt blobs. Other clumps form a complete chain around the star, but are not significantly photoexcited. The strontium filament, a 'neutral' emission structure, lies in the same general direction as the Weigelt blobs and exhibits peculiar properties indicative that much mid-UV, but no hydrogen-ionizing radiation impinges on this structure. It is shielded by singly-ionized iron. P Cygni absorptions in Fe I I lines, seen directly in line of sight from Eta Carinae, are absent in the stellar light scattered by the Weigelt blobs. Rather than a strong absorption extending to -600 km/s, a low velocity absorption feature extends from -40 to -150 km/s. No absorbing Fe II exists between Eta Carinae and Weigelt D, but the outer reaches of the wind are intercepted in line of sight from Weigelt D to the observer. This indicates that the UV radiation is constrained by the dominating wind of Eta Car A to a small cavity carved out by the weaker wind of Eta Car B. Since the high excitation nebular lines are seen in the Weigelt blobs at most phases, the cavity, and hence the major axis of the highly elliptical orbit, must lie in the general direction of the Weigelt blobs. The evidence is compelling that the orbital major axis of Eta Carinae is projected at -45 degrees position angle on the sky. Moreover

Species Composition and Distribution of Adult Anopheles (Diptera: Culicidae) in Panama

PubMed Central

LOAIZA, J. R.; BERMINGHAM, E.; SCOTT, M. E.; ROVIRA, J. R.; CONN, J. E.

2010-01-01

Anopheles (Diptera: Culicidae) species composition and distribution were studied using human landing catch data over a 35-yr period in Panama. Mosquitoes were collected from 77 sites during 228 field trips carried out by members of the National Malaria Eradication Service. Fourteen Anopheles species were identified. The highest average human biting rates were recorded from Anopheles (Nyssorhynchus) albimanus (Wiedemann) (9.8 bites/person/night) and Anopheles (Anopheles) punctimacula (Dyar and Knab) (6.2 bites/person/night). These two species were also the most common, present in 99.1 and 74.9%, respectively, of the sites. Anopheles (Nyssorhynchus) aquasalis (Curry) was encountered mostly in the indigenous Kuna Yala Comarca along the eastern Atlantic coast, where malaria case history and average human biting rate (9.3 bites/person/night) suggest a local role in malaria transmission. An. albimanus, An. punctimacula, and Anopheles (Anopheles) vestitipennis (Dyar and Knab) were more abundant during the rainy season (May–December), whereas An. aquasalis was more abundant in the dry season (January–April). Other vector species collected in this study were Anopheles (Kerteszia) neivai (Howard, Dyar, and Knab) and Anopheles (Anopheles) pseudopunctipennis s.l. (Theobald). High diversity of Anopheles species and six confirmed malaria vectors in endemic areas of Panama emphasize the need for more detailed studies to better understand malaria transmission dynamics. PMID:18826025

Spatial and temporal patterns of imported malaria cases and local transmission in Trinidad.

PubMed

Chadee, D D; Kitron, U

1999-10-01

Over a 30-year period (1968-1997) 213 malaria cases in Trinidad were investigated by the Trinidad and Tobago Ministry of Health. Using a global positional system and a geographic information system, we mapped the precise location of all reported malaria cases, and associated them with breeding habitats of anopheline vectors. The majority of the cases (138, 63%) were individual imported cases around the big port cities. Plasmodium falciparum was the most common parasite, and Africa the most common source of imported cases. Two clusters of cases occurred: an introduced P. vivax outbreak associated with Anopheles aquasalis in 1990-1991, and an autochtonous focus of P. malariae associated with An. bellator and An. homunculus in 1994-1995. Application of a space-time statistic showed a significant clustering of P. malariae cases, and, to a lesser extent of P. vivax cases, but not of P. falciparum cases. Based on potential for occurrence of local transmission, we are developing risk maps to determine surveillance priorities, outbreak potential, and necessary degree and spatial range of control activities following case detections.

Signs of η Carinae Outburst in Artifacts of Ancient Bolivia

NASA Astrophysics Data System (ADS)

Teames, Sallie

Recent HST and X-ray photos of η Carinae reveal the bipolar gaseous lobes--the Homunculus Nebula--created by the star's "Great Eruption of 1843." From debris gases on the outskirts beyond the two gaseous lobes, astrophysicists surmise an earlier outburst. The 1999 Chandra X-ray photo of the horseshoe-shaped outer nebula surrounding the bipolar lobes indicates an earlier outburst occurring over a thousand years ago. Because η Carinae is so far south, it is entirely possible that the outburst would not have been seen by the Chinese and other observers in the northern hemisphere. Researchers are looking for possible recordings by early southern hemisphere observers. Pre-Incan artifacts excavated in Bolivia may provide an answer. In the script and artwork carvings on a monolith stone statue, an artifact of the Tiahuanacan culture, are signs possibly depicting the earlier outburst of η Carinae--the recordings of a star that suddenly brightened in their night sky. Two small stones from the same era and also found on the south shore of Lake Titicaca may also show depictions related to this brightening.

Causal Neuro-immune Relationships at Patients with Chronic Pyelonephritis and Cholecystitis. Correlations between Parameters EEG, HRV and White Blood Cell Count

PubMed Central

Kul’chyns’kyi, Andriy B; Kyjenko, Valeriy M; Zukow, Walery; Popovych, Igor L

2017-01-01

Abstract We aim to analyze in bounds KJ Tracey’s immunological homunculus conception the relationships between parameters of electroencephalogram (EEG) and heart rate variability (HRV), on the one hand, and the parameters of bhite blood cell count, on the other hand. Methods In basal conditions in 23 men, patients with chronic pyelonephritis and cholecystitis in remission, recorded EEG (“NeuroCom Standard”, KhAI Medica, Ukraine) and HRV (“Cardiolab+VSR”, KhAI Medica, Ukraine). In portion of blood counted up white blood cell count. Results Revealed that canonical correlation between constellation EEG and HRV parameters form with blood level of leukocytes 0.92 (p<10-5), with relative content in white blood cell count stubnuclear neutrophiles 0.93 (p<10-5), segmentonucleary neutrophiles 0.89 (p<10-3), eosinophiles 0.87 (p=0.003), lymphocytes 0.77 (p<10-3) and with monocytes 0.75 (p=0.003). Conclusion Parameters of white blood cell count significantly modulated by electrical activity some structures of central and autonomic nervous systems. PMID:28730179

The cortical sensory representation of genitalia in women and men: a systematic review

PubMed Central

Cazala, Fadwa; Vienney, Nicolas; Stoléru, Serge

2015-01-01

Background Although genital sensations are an essential aspect of sexual behavior, the cortical somatosensory representation of genitalia in women and men remain poorly known and contradictory results have been reported. Objective To conduct a systematic review of studies based on electrophysiological and functional neuroimaging studies, with the aim to identify insights brought by modern methods since the early descriptions of the sensory homunculus in the primary somatosensory cortex (SI). Results The review supports the interpretation that there are two distinct representations of genital sensations in SI, one on the medial surface and the other on the lateral surface. In addition, the review suggests that the secondary somatosensory cortex and the posterior insula support a representation of the affective aspects of genital sensation. Conclusion In view of the erogenous character of sensations originating in the genitalia, future studies on this topic should systematically assess qualitatively as well as quantitatively the sexually stimulating and/or sexually pleasurable characteristics of sensations felt by subjects in response to experimental stimuli. PMID:25766001

Vector competence of Peruvian mosquitoes (Diptera: Culicidae) for epizootic and enzootic strains of Venezuelan equine encephalomyelitis virus.

PubMed

Turell, M J; Jones, J W; Sardelis, M R; Dohm, D J; Coleman, R E; Watts, D M; Fernandez, R; Calampa, C; Klein, T A

2000-11-01

Mosquitoes collected in the Amazon Basin, near Iquitos, Peru, were evaluated for their susceptibility to epizootic (IAB and IC) and enzootic (ID and IE) strains of Venezuelan equine encephalomyelitis (VEE) virus. After feeding on hamsters with a viremia of approximately 10(8) plaque-forming units of virus per milliliter, Culex (Melanoconion) gnomatus Sallum, Huchings, & Ferreira, Culex (Melanoconion) vomerifer Komp, and Aedes fulvus (Wiedemann) were highly susceptible to infection with all four subtypes of VEE virus (infection rates > or = 87%). Likewise, Psorophora albigenu (Peryassu) and a combination of Mansonia indubitans Dyar & Shannon and Mansonia titillans (Walker) were moderately susceptible to all four strains of VEE virus (infection rates > or = 50%). Although Psorophora cingulata (Fabricius) and Coquillettidia venezuelensis (Theobald) were susceptible to infection with each of the VEE strains, these two species were not efficient transmitters of any of the VEE strains, even after intrathoracic inoculation, indicating the presence of a salivary gland barrier in these species. In contrast to the other species tested, both Culex (Melanoconion) pedroi Sirivanakarn & Belkin and Culex (Culex) coronator Dyar & Knab were nearly refractory to each of the strains of VEE virus tested. Although many of the mosquito species found in this region were competent laboratory vectors of VEE virus, additional studies on biting behavior, mosquito population densities, and vertebrate reservoir hosts of VEE virus are needed to incriminate the principal vector species.

BRITE-Constellation reveals evidence for pulsations in the enigmatic binary η Carinae

NASA Astrophysics Data System (ADS)

Richardson, Noel D.; Pablo, Herbert; Sterken, Christiaan; Pigulski, Andrzej; Koenigsberger, Gloria; Moffat, Anthony F. J.; Madura, Thomas I.; Hamaguchi, Kenji; Corcoran, Michael F.; Damineli, Augusto; Gull, Theodore R.; Hillier, D. John; Weigelt, Gerd; Handler, Gerald; Popowicz, Adam; Wade, Gregg A.; Weiss, Werner W.; Zwintz, Konstanze

2018-04-01

η Car is a massive, eccentric binary with a rich observational history. We obtained the first high-cadence, high-precision light curves with the BRITE-Constellation nanosatellites over 6 months in 2016 and 6 months in 2017. The light curve is contaminated by several sources including the Homunculus nebula and neighbouring stars, including the eclipsing binary CPD -59°2628. However, we found two coherent oscillations in the light curve. These may represent pulsations that are not yet understood but we postulate that they are related to tidally excited oscillations of η Car's primary star, and would be similar to those detected in lower mass eccentric binaries. In particular, one frequency was previously detected by van Genderen et al. and Sterken et al. through the time period of 1974-1995 through timing measurements of photometric maxima. Thus, this frequency seems to have been detected for nearly four decades, indicating that it has been stable in frequency over this time span. These pulsations could help provide the first direct constraints on the fundamental parameters of the primary star if confirmed and refined with future observations.

Taurodontism, variations in tooth number, and misshapened crowns in Wnt10a null mice and human kindreds

PubMed Central

Yang, Jie; Wang, Shih-Kai; Choi, Murim; Reid, Bryan M; Hu, Yuanyuan; Lee, Yuan-Ling; Herzog, Curtis R; Kim-Berman, Hera; Lee, Moses; Benke, Paul J; Kent Lloyd, K C; Simmer, James P; Hu, Jan C-C

2015-01-01

WNT10A is a signaling molecule involved in tooth development, and WNT10A defects are associated with tooth agenesis. We characterized Wnt10a null mice generated by the knockout mouse project (KOMP) and six families with WNT10A mutations, including a novel p.Arg104Cys defect, in the absence of EDA,EDAR, or EDARADD variations. Wnt10a null mice exhibited supernumerary mandibular fourth molars, and smaller molars with abnormal cusp patterning and root taurodontism. Wnt10a−/− incisors showed distinctive apical–lingual wedge-shaped defects. These findings spurred us to closely examine the dental phenotypes of our WNT10A families. WNT10A heterozygotes exhibited molar root taurodontism and mild tooth agenesis (with incomplete penetrance) in their permanent dentitions. Individuals with two defective WNT10A alleles showed severe tooth agenesis and had fewer cusps on their molars. The misshapened molar crowns and roots were consistent with the Wnt10a null phenotype and were not previously associated with WNT10A defects. The missing teeth contrasted with the presence of supplemental teeth in the Wnt10a null mice and demonstrated mammalian species differences in the roles of Wnt signaling in early tooth development. We conclude that molar crown and root dysmorphologies are caused by WNT10A defects and that the severity of the tooth agenesis correlates with the number of defective WNT10A alleles. PMID:25629078

Arap1 Deficiency Causes Photoreceptor Degeneration in Mice.

PubMed

Moshiri, Ala; Humpal, Devin; Leonard, Brian C; Imai, Denise M; Tham, Addy; Bower, Lynette; Clary, Dave; Glaser, Thomas M; Lloyd, K C Kent; Murphy, Christopher J

2017-03-01

Small guanosine triphosphatase (GTPase) ADP-ribosylation factors (Arfs) regulate membrane traffic and actin reorganization under the control of GTPase-activating proteins (GAPs). Arap1 is an Arf-directed GAP that inhibits the trafficking of epidermal growth factor receptor (EGFR) to the early endosome, but the diversity of its functions is incompletely understood. The aim of this study was to determine the role of Arap1 in the mammalian retina. Genetically engineered Arap1 knockout mice were screened for ocular abnormalities in the National Institutes of Health Knockout Mouse Production and Phenotyping (KOMP2) Project. Arap1 knockout and wild-type eyes were imaged using optical coherence tomography and fundus photography, and analyzed by immunohistochemistry. Arap1-/- mice develop a normal appearing retina, but undergo photoreceptor degeneration starting at 4 weeks postnatal age. The fundus appearance of mutants is notable for pigmentary changes, optic nerve pallor, vascular attenuation, and outer retinal thinning, reminiscent of retinitis pigmentosa in humans. Immunohistochemical studies suggest the cell death is predominantly in the outer nuclear layer. Functional evaluation of the retina by electroretinography reveals amplitudes are reduced. Arap1 is detected most notably in Müller glia, and not in photoreceptors, implicating a role for Müller glia in photoreceptor survival. Arap1 is necessary for normal photoreceptor survival in mice, and may be a novel gene relevant to human retinal degenerative processes, although its mechanism is unknown. Further studies in this mouse model of retinal degeneration will give insights into the cellular functions and signaling pathways in which Arap1 participates.

Mapping multisensory parietal face and body areas in humans.

PubMed

Huang, Ruey-Song; Chen, Ching-fu; Tran, Alyssa T; Holstein, Katie L; Sereno, Martin I

2012-10-30

Detection and avoidance of impending obstacles is crucial to preventing head and body injuries in daily life. To safely avoid obstacles, locations of objects approaching the body surface are usually detected via the visual system and then used by the motor system to guide defensive movements. Mediating between visual input and motor output, the posterior parietal cortex plays an important role in integrating multisensory information in peripersonal space. We used functional MRI to map parietal areas that see and feel multisensory stimuli near or on the face and body. Tactile experiments using full-body air-puff stimulation suits revealed somatotopic areas of the face and multiple body parts forming a higher-level homunculus in the superior posterior parietal cortex. Visual experiments using wide-field looming stimuli revealed retinotopic maps that overlap with the parietal face and body areas in the postcentral sulcus at the most anterior border of the dorsal visual pathway. Starting at the parietal face area and moving medially and posteriorly into the lower-body areas, the median of visual polar-angle representations in these somatotopic areas gradually shifts from near the horizontal meridian into the lower visual field. These results suggest the parietal face and body areas fuse multisensory information in peripersonal space to guard an individual from head to toe.

Imaging with HST the Time Evolution of Eta Carinae's Colliding Winds

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Madura, Thomas I.; Groh, Jose H.; Corcoran, Michael F.

2011-01-01

We report new HST/STIS observations that map the high-ionization forbidden line emission in the inner arcsecond of Eta Car, the first that fully image the extended wind-wind interaction region of the massive colliding wind binary. These observations were obtained after the 2009.0 periastron at orbital phases 0.084, 0.163, and 0.323 of the 5.54-year spectroscopic cycle. We analyze the variations in brightness and morphology of the emission, and find that blue-shifted emission (-400 to -200 km/s is symmetric and elongated along the northeast-southwest axis, while the red-shifted emission (+ 100 to +200 km/s) is asymmetric and extends to the north-northwest. Comparison to synthetic images generated from a 3-D dynamical model strengthens the 3-D orbital orientation found by Madura et al. (2011), with an inclination i approx. 138deg, argument of periapsis omega approx. 270deg, and an orbital axis that is aligned at the same PA on the sky as the symmetry axis of the Homunculus, 312deg. We discuss the potential that these and future mappings have for constraining the stellar parameters of the companion star and the long-term variability of the system.

Blacked-out spaces: Freud, censorship and the re-territorialization of mind.

PubMed

Galison, Peter

2012-06-01

Freud's analogies were legion: hydraulic pipes, military recruitment, magic writing pads. These and some three hundred others took features of the mind and bound them to far-off scenes--the id only very partially resembles an uncontrollable horse, as Freud took pains to note. But there was one relation between psychic and public act that Freud did not delimit in this way: censorship, the process that checked memories and dreams on their way to the conscious. (Freud dubbed the relation between internal and external censorship a 'parallel' rather than a limited analogy.) At first, Freud likened this suppression to the blacking out of texts at the Russian frontier. During the First World War, he suffered, and spoke of suffering under, Viennese postal and newspaper censorship--Freud was forced to leave his envelopes unsealed, and to recode or delete content. Over and over, he registered the power of both internal and public censorship in shared form: distortion, anticipatory deletion, softenings, even revision to hide suppression. Political censorship left its mark as the conflict reshaped his view of the psyche into a society on a war footing, with homunculus-like border guards sifting messages as they made their way--or did not--across a topography of mind.

Hubble Space Telescope imaging of Eta Carinae

NASA Technical Reports Server (NTRS)

Hester, J. J.; Westphal, James A.; Light, Robert M.; Currie, Douglas G.; Groth, Edward J.

1991-01-01

New high spatial resolution observations of the material around Eta Carinae, obtained with the Hubble Space Telescope Wide Field/Planetary Camera, are presented. The star Eta Carinae is one of the most massive and luminous stars in the Galaxy, and has been episodically expelling significant quantities of gas over the last few centuries. The morphology of the bright central nebulosity (the homunculus) indicates that it is a thin shell with very well defined edges, and is clumpy on 0.2 arcsec (about 10 to the 16th cm) scales. An extension to the northeast of the star (NN/NS using Walborn's 1976 nomenclature) appears to be a stellar jet and its associated bow shock. The bow shock is notable for an intriguing series of parallel linear features across its face. The S ridge and the W arc appear to be part of a 'cap' of emission located to the SW and behind the star. Together, the NE jet and the SW cap suggest that the symmetry axis for the system runs NE-SW rather than SE-NW, as previously supposed. Overall, the data indicate that the material around the star may represent an oblate shell with polar blowouts, rather than a bipolar flow.

The body, its emotions, the self, and consciousness.

PubMed

Boyd, Graham W

2012-01-01

This article proposes a means for better understanding the self and consciousness. Data indicate that the basic "emotional brain" continually computes potential survival risk against reward to rank consequent "emotion scores" for all sensory inputs. These scores compete to yield winner-takes-all outcomes that determine the choice of attention or action. This mechanism prevails regardless of whether the competing options gain their emotion scores through a rational or an intuitive pathway. There is no need to postulate any homunculus or inner self in control of such choice; indeed, our belief in a first-person self in overall control is wrong. The self is a passive construct arising from each individual's social development, where language acquisition vastly heightens communication and awareness not only outwardly, but also inwardly, as if to a controlling "inner I." However, when society comes to hold the maturing being accountable for his or her actions, the brain must respond, and it does so in the only way it can, by deeming that this passive, inner self-construct act as if it were the active self in charge. Consciousness emerges when the language-based output of the higher brain is referred for ownership to this artificial self-construct.

Spatial Distribution and Kinematics of the Molecular Material Associated with eta Carinae

NASA Astrophysics Data System (ADS)

Loinard, Laurent; Kamiński, Tomasz; Serra, Paolo; Menten, Karl M.; Zapata, Luis A.; Rodríguez, Luis F.

2016-12-01

Single-dish submillimeter observations have recently revealed the existence of a substantial, chemically peculiar molecular gas component located in the innermost circumstellar environment of the very massive luminous blue variable star, η Carinae. Here, we present 5″-resolution interferometric observations of the 1\\to 0 rotational transition of hydrogen cyanide (HCN) toward this star obtained with the Australia Telescope Compact Array. The emission is concentrated in the central few arcseconds around η Carinae and shows a clear 150 km s-1 velocity gradient running from west-north-west (blue) to east-south-east (red). Given the extent, location, and kinematics of this molecular material, we associate it with the complex of dusty arcs and knots seen in mid-infrared emission near the center of the Homunculus nebula. Indeed, the shielding provided by this dust could help explain how molecules survive in the presence of the intense UV radiation field produced by η Carinae. The dust located in the central few arcseconds around η Carinae and the molecular component described here most likely formed in situ and out of material expelled by the massive interacting binary system. Thus, η Carinae offers us a rare glimpse of the processes that lead to the formation of dust and molecules around massive stars, which are relevant to the interpretation of dust and molecule detections at high redshifts.

Explaining the features of the Bipolar Nebulae of η-Carinae through gas dynamical simulations

NASA Astrophysics Data System (ADS)

de Gouveia dal Pino, E. M.; Gonzalez, R. F.; Raga, A. C.; Velezquez, P. F.

2005-09-01

Employing an alternative scenario to previous interacting stellar wind models that is supported both by theoretical and observational evidence, we let a nonspherical outburst wind (with a latitudinal velocity dependence that matches the observations of the large Homunculus) interact with a preeruptive slow wind also with a toroidal density distribution but with a much smaller equator-to-polar density contrast than that assumed in previous models. A second eruptive wind with spherical shape is ejected about 50 years after the first outburst and causes the development of the little internal nebula. We find that as a result of an appropriate combination of the parameters that control the degree of asymmetry of the interacting winds, the model is able to produce not only the structure and kinematics of both Homunculi but also the high-velocity components of the equatorial ejecta. These latter arise from the impact between the nonspherical outburst and the preoutburst winds in the equatorial plane (see Figs. 1 and 2 in Gonzalez, de Gouveia Dal Pino, Raga & Velazquez 2004a). Our model predicts that most of the features of the bipolar winds of eta-Carinae and the source ejection mechanism are directly linked to the central star only, therefore without requiring to invoke the secondary wind of the companion star to explain, e.g., the equatorial ejecta (Gonzalez, de Gouveia Dal Pino, Raga & Velazquez 2004b).

Observations of a Windy Star

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2017-06-01

Hubble view of the Homunculus Nebula surrounding Eta Carinae [NASA Hubble Space Telescope/Jon Morse (University of Colorado)]The incredibly luminous massive star Eta Carinae has long posed a challenge for astronomers to model. New observations are now in so were our models correct?Dramatic TargetThe massive evolved star Eta Carinae, located 7,500 light-years away in the constellation Carina, is the most luminous star in the Milky Way. Eta Carinae has a quite a reputation for drama: it has been very unstable in the past, exhibiting repeated eruptions that have created the spectacular Homunculus Nebula surrounding it. Its present-day wind has the highest mass-loss rate of any hot star weve observed.Picture of Stellar WindTop panel: February 2017 observations of Eta Carinae in continuum (left) and H-alpha. Middle panel: the normalized radial profile for H-alpha and continuum emission. Bottom panel: the full width at half maximum for H-alpha and continuum emission of Eta Carinae. The H-alpha is about 2.5 to 3 milliarcseconds wider than the continuum. [Adapted from Wu et al. 2017]In our goal to understand the late evolutionary phases of very massive stars, weve developed radiative-transfer models to explain the behavior of Eta Carinae. One of the most well-known models, developed by John Hillier and collaborators in 2001, describes Eta Carinaes mass loss via stellar winds. With the right observations, this model is testable, since it predicts observable locations for different types of emission. In particular, one prediction of the Hillier et al. model is that the dense, ionized winds surrounding the star should emit in H-alpha at distances between 6 and 60 AU, with a peak around 20 AU.This nicely testable hypothesis is rendered less convenient by the fact that its hard to get resolved images of Eta Carinaes H-alpha emission. Its distance from us and the fact that its shrouded in the complex nebula it created have thus far prevented us from resolving the H

Subcortical barrelette-like and barreloid-like structures in the prosimian galago (Otolemur garnetti)

PubMed Central

Sawyer, Eva Kille; Liao, Chia-Chi; Qi, Hui-Xin; Balaram, Pooja; Matrov, Denis; Kaas, Jon H.

2015-01-01

Galagos are prosimian primates that resemble ancestral primates more than most other extant primates. As in many other mammals, the facial vibrissae of galagos are distributed across the upper and lower jaws and above the eye. In rats and mice, the mystacial macrovibrissae are represented throughout the ascending trigeminal pathways as arrays of cytoarchitecturally distinct modules, with each module having a nearly one-to-one relationship with a specific facial whisker. The macrovibrissal representations are termed barrelettes in the trigeminal somatosensory brainstem, barreloids in the ventroposterior medial subnucleus of the thalamus, and barrels in primary somatosensory cortex. Despite the presence of facial whiskers in all nonhuman primates, barrel-like structures have not been reported in primates. By staining for cytochrome oxidase, Nissl, and vesicular glutamate transporter proteins, we show a distinct array of barrelette-like and barreloid-like modules in the principal sensory nucleus, the spinal trigeminal nucleus, and the ventroposterior medial subnucleus of the galago, Otolemur garnetti. Labeled terminals of primary sensory neurons in the brainstem and cell bodies of thalamocortically projecting neurons demonstrate that barrelette-like and barreloid-like modules are located in areas of these somatosensory nuclei that are topographically consistent with their role in facial touch. Serendipitously, the plane of section that best displays the barreloid-like modules reveals a remarkably distinct homunculus-like patterning which, we believe, is one of the clearest somatotopic maps of an entire body surface yet found. PMID:26038561

Interferometric observations of η Carinae with VINCI/VLTI

NASA Astrophysics Data System (ADS)

Kervella, P.

2007-03-01

Context: The bright star η Carinae is the most massive and luminous star in our region of the Milky Way. Though it has been extensively studied using many different techniques, its physical nature and the mechanism that led to the creation of the Homunculus nebula are still debated. Aims: We aimed at resolving the central engine of the η Carinae complex in the near-infrared on angular scales of a few milliarcseconds. Methods: We used the VINCI instrument of the VLTI to recombine coherently the light from two telescopes in the K band. Results: We report a total of 142 visibility measurements of η Car, part of which were analyzed by Van Boekel et al. (2003, A&A, 410, L37). These observations were carried out on projected baselines ranging from 8 to 112 m in length, using either two 0.35 m siderostats or two 8-m Unit Telescopes. These observations cover the November 2001-January 2004 period. Conclusions: .The reported visibility data are in satisfactory agreement with the recent results obtained with AMBER/VLTI by Weigelt et al. (2006), asuming that the flux of η Car encircled within 70 mas reaches 56% of the total flux within 1400 mas, in the K band. We also confirm that the squared visibility curve of η Car as a function of spatial frequency follows closely an exponential model. Table 1 is only available in electronic form at http://www.aanda.org

A disrupted molecular torus around Eta Carinae as seen in 12CO with ALMA

NASA Astrophysics Data System (ADS)

Smith, Nathan; Ginsburg, Adam; Bally, John

2018-03-01

We present Atacama Large Millimeter Array (ALMA) observations of 12CO 2-1 emission from circumstellar material around the massive star Eta Carinae (η Car). These observations reveal new structural details about the cool equatorial torus located ˜4000 au from the star. The CO torus is not a complete azimuthal loop, but rather, is missing its near side, which appears to have been cleared away. The missing material matches the direction of apastron in the eccentric binary system, making it likely that η Car's companion played an important role in disrupting portions of the torus soon after ejection. Molecular gas seen in ALMA data aligns well with the cool dust around η Car previously observed in mid-infrared (IR) maps, whereas hot dust resides at the inner surface of the molecular torus. The CO also coincides with the spatial and velocity structure of near-IR H2 emission. Together, these suggest that the CO torus seen by ALMA is actually the pinched waist of the Homunculus polar lobes, which glows brightly because it is close to the star and warmer than the poles. The near side of the torus appears to be a blowout, associated with fragmented equatorial ejecta. We discuss implications for the origin of various features north-west of the star. CO emission from the main torus implies a total gas mass in the range of 0.2-1 M⊙ (possibly up to 5 M⊙ or more, although with questionable assumptions). Deeper observations are needed to constrain CO emission from the cool polar lobes.

Eta Carinae's Change of State: The End Game

NASA Astrophysics Data System (ADS)

Davidson, Kris

2017-08-01

Eta Car is the only giant-eruption survivor that can be observed well. Hence it is genuinely unique for testing instability theories which are crucial for very massive stars. Fortuitously, a rapid change of state began about 1998. This represents an unexpected stage in the recovery following the Great Eruption (supernova impostor event) seen 170 years ago. Now there are reasons to think that the change of state is nearly complete. HST/STIS has been the main source of information on this phenomenon, and is the only instrument that can show the final (or nearly final) state. Therefore we propose to complete this record in Cy 25. The archival value is very high, because similar observations will later be impossible; the star is changing irreversibly. HST is needed, because UV is essential and because all ground-based spectroscopy of eta Car is heavily contaminated by emission lines formed about 0.3 arcsec away. For this object each HST orbit produces many high-quality spectra. The same data apply to other problems, e.g. exotic emission processes in the ejecta, bipolar structures, and the nature of the companion star.We propose STIS observations: (1) A final update of the central star's wind spectrum at selected NUV-to-red wavelengths. (2) Brief UV spectroscopy with the MAMA echelle. This will be the only such data obtained at a time when the companion star is near apoastron. (3) Special sampling of the Homunculus ejecta-nebula using STIS/CCD with long exposure times. This was done once before, in 2000, and major changes have occurred since then.

Group-level variations in motor representation areas of thenar and anterior tibial muscles: Navigated Transcranial Magnetic Stimulation Study.

PubMed

Niskanen, Eini; Julkunen, Petro; Säisänen, Laura; Vanninen, Ritva; Karjalainen, Pasi; Könönen, Mervi

2010-08-01

Navigated transcranial magnetic stimulation (TMS) can be used to stimulate functional cortical areas at precise anatomical location to induce measurable responses. The stimulation has commonly been focused on anatomically predefined motor areas: TMS of that area elicits a measurable muscle response, the motor evoked potential. In clinical pathologies, however, the well-known homunculus somatotopy theory may not be straightforward, and the representation area of the muscle is not fixed. Traditionally, the anatomical locations of TMS stimulations have not been reported at the group level in standard space. This study describes a methodology for group-level analysis by investigating the normal representation areas of thenar and anterior tibial muscle in the primary motor cortex. The optimal representation area for these muscles was mapped in 59 healthy right-handed subjects using navigated TMS. The coordinates of the optimal stimulation sites were then normalized into standard space to determine the representation areas of these muscles at the group-level in healthy subjects. Furthermore, 95% confidence interval ellipsoids were fitted into the optimal stimulation site clusters to define the variation between subjects in optimal stimulation sites. The variation was found to be highest in the anteroposterior direction along the superior margin of the precentral gyrus. These results provide important normative information for clinical studies assessing changes in the functional cortical areas because of plasticity of the brain. Furthermore, it is proposed that the presented methodology to study TMS locations at the group level on standard space will be a suitable tool for research purposes in population studies. 2010 Wiley-Liss, Inc.

CRITICAL DIFFERENCES AND CLUES IN ETA CAR'S 2009 EVENT ,

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehner, Andrea; Davidson, Kris; Humphreys, Roberta M.

2011-10-20

We monitored Eta Carinae with the Hubble Space Telescope WFPC2 and Gemini GMOS throughout the 2009 spectroscopic event, which was expected to differ from its predecessor in 2003. Here we report major observed differences between events and their implications. Some of these results were quite unexpected. (1) The UV brightness minimum was much deeper in 2009. This suggests that physical conditions in the early stages of an event depend on different parameters than the 'normal' inter-event wind. Extra mass ejection from the primary star is one possible cause. (2) The expected He II {lambda}4687 brightness maximum was followed several weeksmore » later by another. We explain why this fact and the timing of the {lambda}4687 maxima strongly support a 'shock breakup' hypothesis for X-ray and {lambda}4687 behavior as proposed 5-10 years ago. (3) We observed a polar view of the star via light reflected by dust in the Homunculus nebula. Surprisingly, at that location, the variations of emission-line brightness and Doppler velocities closely resembled a direct view of the star, which should not have been true for any phenomena related to the orbit. This result casts very serious doubt on all the proposed velocity interpretations that depend on the secondary star's orbital motion. (4) Latitude-dependent variations of H I, He I, and Fe II features reveal aspects of wind behavior during the event. In addition, we discuss implications of the observations for several crucial unsolved problems.« less

Promises and pitfalls of a Pannexin1 transgenic mouse line.

PubMed

Hanstein, Regina; Negoro, Hiromitsu; Patel, Naman K; Charollais, Anne; Meda, Paolo; Spray, David C; Suadicani, Sylvia O; Scemes, Eliana

2013-01-01

Gene targeting strategies have become a powerful technology for elucidating mammalian gene function. The recently generated knockout (KO)-first strategy produces a KO at the RNA processing level and also allows for the generation of conditional KO alleles by combining FLP/FRT and Cre/loxP systems, thereby providing high flexibility in gene manipulation. However, this multipurpose KO-first cassette might produce hypomorphic rather than complete KOs if the RNA processing module is bypassed. Moreover, the generation of a conditional phenotype is also dependent on specific activity of Cre recombinase. Here, we report the use of an efficient molecular biological approach to test pannexin1 (Panx1) mRNA expression in global and conditional Panx1 KO mice derived from the KO-first mouse line, Panx1(tm1a(KOMP)Wtsi). Using qRT-PCR, we demonstrate that tissues from wild-type (WT) mice show a range of Panx1 mRNA expression levels, with highest expression in trigeminal ganglia, bladder and spleen. Unexpectedly, we found that in mice homozygous for the KO-first allele, Panx1 mRNA expression is not abolished but reduced by 70% compared to that of WT tissues. Thus, Panx1 KO-first mice present a hypomorphic phenotype. Crosses of Panx1 KO-first with FLP deleter mice generated Panx1(f/f) mice. Further crosses of the latter mice with mGFAP-Cre or NFH-Cre mice were used to generate astrocyte- and neuron-specific Panx1 deletions, respectively. A high incidence of ectopic Cre expression was found in offspring of both types of conditional Panx1 KO mice. Our study demonstrates that Panx1 expression levels in the global and conditional Panx1 KO mice derived from KO-first mouse lines must be carefully characterized to ensure modulation of Panx1 gene expression. The precise quantitation of Panx1 expression and its relation to function is expected to provide a foundation for future efforts aimed at deciphering the role of Panx1 under physiological and pathological conditions.

Oldest known cranium of a juvenile New World monkey (Early Miocene, Patagonia, Argentina): implications for the taxonomy and the molar eruption pattern of early platyrrhines.

PubMed

Perry, Jonathan M G; Kay, Richard F; Vizcaíno, Sergio F; Bargo, M Susana

2014-09-01

A juvenile cranium of Homunculus patagonicus Ameghino, 1891a from the late Early Miocene of Santa Cruz Province (Argentina) provides the first evidence of developing cranial anatomy for any fossil platyrrhine. The specimen preserves the rostral part of the cranium with deciduous and permanent alveoli and teeth. The dental eruption sequence in the new specimen and a reassessment of eruption patterns in living and fossil platyrrhines suggest that the ancestral platyrrhine pattern of tooth replacement was for the permanent incisors to erupt before M(1), not an accelerated molar eruption (before the incisors) as recently proposed. Two genera and species of Santacrucian monkeys are now generally recognized: H. patagonicus Ameghino, 1891a and Killikaike blakei Tejedor et al., 2006. Taxonomic allocation of Santacrucian monkeys to these species encounters two obstacles: 1) the (now lost) holotype and a recently proposed neotype of H. patagonicus are mandibles from different localities and different geologic members of the Santa Cruz Formation, separated by approximately 0.7 million years, whereas the holotype of K. blakei is a rostral part of a cranium without a mandible; 2) no Santacrucian monkey with associated cranium and mandible has ever been found. Bearing in mind these uncertainties, our examination of the new specimen as well as other cranial specimens of Santacrucian monkeys establishes the overall dental and cranial similarity between the holotype of Killikaike blakei, adult cranial material previously referred to H. patagonicus, and the new juvenile specimen. This leads us to conclude that Killikaike blakei is a junior subjective synonym of H. patagonicus. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Spatially-resolved Interacting Winds of Eta Carinae: Implications on the Orbit Orientation

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Nielsen, K.E.; Corcoran, M.; Hamaguchi, K.; Madura, T.; Russell, C.; Hillier, D.J.; Owocki. S.; Okazaki, A.T.

2010-01-01

Medium-dispersion long slit spectra, recorded by HST/STIS (R=8000, Theta=0.l"), resolve the extended wind-wind interaction region of the massive binary, Eta Carinae. During the high state, extending for about five years of the 5.54-year binary period, lines of [N II], [Fe III], [S III], [Ar III] and [Ne III] extend outwards to 0.4" with a velocity range of -500 to +200 km/s. By comparison, lines of [Fe II] and [Ni II] extend to 0.7" with a velocity range of -500 to +500 km/s. During the high state, driven by the lesser wind of Eta Car B and photo-ionized by the FUV of Eta Car B, the high excitation lines originate in or near the outer ballistic portions of the wind-wind interaction region. The lower excitation lines ([Fe II] and [Ni II D originate from the boundary regions of the dominating wind of Eta Car A. As the binary system has an eccentricity exceeding 0.9, the two stars approach quite close across the periastron, estimated to be within 1 to 2 AU. As a result, Eta Car B moves into the primary wind structure, cutting off the FUV supporting the ionization of the high state lines. Forbidden emission lines of the doubly-ionized species disappear, He II 4686 drops along with the collapse of the X-ray flux. This behavior is understood through the 3-D models of A. Okazaki and of E. R. Parkin and Pittard. Discussion will address the orbit orientation relative to the geometry of the Homunculus, ejected by Eta Carinae in the 1840s.

The Spatially-resolved Interacting Winds of Eta Carinae: Implications on the Orbit Orientation

NASA Astrophysics Data System (ADS)

Gull, Theodore R.; Nielsen, K. E.; Corcoran, M.; Hamaguchi, K.; Madura, T.; Russell, C.; Hillier, D. J.; Owocki, S.; Okazaki, A. T.

2010-01-01

Medium-dispersion long slit spectra, recorded by HST/STIS (R=8000, Theta=0.1"), resolve the extended wind-wind interaction region of the massive binary, Eta Carinae. During the high state, extending for about five years of the 5.54-year binary period, lines of [N II], [Fe III], [S III], [Ar III] and [Ne III] extend outwards to 0.4" with a velocity range of -500 to +200 km/s. By comparison, lines of [Fe II] and [Ni II] extend to 0.7" with a velocity range of -500 to +500 km/s. During the high state, driven by the lesser wind of Eta Car B and photo-ionized by the FUV of Eta Car B, the high excitation lines originate in or near the outer ballistic portions of the wind-wind interaction region. The lower excitation lines ([Fe II] and [Ni II]) originate from the boundary regions of the dominating wind of Eta Car A. As the binary system has an eccentricity exceeding 0.9, the two stars approach quite close across the periastron, estimated to be within 1 to 2 AU. As a result, Eta Car B moves into the primary wind structure, cutting off the FUV supporting the ionization of the high state lines. Forbidden emission lines of the doubly-ionized species disappear, He II 4686 drops along with the collapse of the X-ray flux. This behavior is understood through the 3-D models of A. Okazaki and of E. R. Parkin and Pittard. Discussion will address the orbit orientation relative to the geometry of the Homunculus, ejected by Eta Carinae in the 1840s.

The Persistent Eruption of UGC 2773-OT: finally, a decade-long extragalactic Eta Carinae analogue

NASA Astrophysics Data System (ADS)

Smith, Nathan; Andrews, Jennifer E.; Mauerhan, Jon C.; Zheng, WeiKang; Filippenko, Alexei V.; Graham, Melissa L.; Milne, Peter

2016-02-01

While supernova (SN) impostors resemble the Great Eruption of η Carinae in the sense that their spectra show narrow H lines and they have typical peak absolute magnitudes of -13 to -14 mag, most extragalactic events observed so far are quite different from η Car in duration. Their bright phases typically last for ˜100 d or less, rather than persisting for several years. The transient object UGC 2773-OT (discovered in 2009) had a similar peak absolute magnitude to other SN impostors, but with a gradual 5-yr pre-discovery rise. In the ˜6 yr since discovery, it has faded very slowly (0.26 mag yr-1). Overall, we suggest that its decade-long eruption is so far the best-known analogue of η Car's 19th century eruption. We discuss extensive spectroscopy of the ongoing eruption. The spectra show interesting changes in velocity and line shape that we discuss in detail, including an asymmetric Hα emission line that we show is consistent with the ejection of a bipolar nebula that could be very much like the Homunculus of η Car. Moreover, changes in the line width, line profile, blue excess emission resembling that of Type IIn SNe, and the intensity of Hα suggest the presence of strong circumstellar interaction in the eruption at late times. This supports the hypothesis that the extended plateau of η Car's eruption may have been powered by shock interaction as well. One interesting difference compared to η Car, however, is that UGC 2773-OT so far does not exhibit the repeated brief spikes in luminosity that have been associated with binary periastron events.

Disruption of Functional Organization Within the Primary Motor Cortex in Children With Autism

PubMed Central

Nebel, Mary Beth; Joel, Suresh E.; Muschelli, John; Barber, Anita D.; Caffo, Brian S.; Pekar, James J.; Mostofsky, Stewart H.

2013-01-01

Accumulating evidence suggests that motor impairments are prevalent in autism spectrum disorder (ASD), relate to the social and communicative deficits at the core of the diagnosis and may reflect abnormal connectivity within brain networks underlying motor control and learning. Parcellation of resting-state functional connectivity data using spectral clustering approaches has been shown to be an effective means of visualizing functional organization within the brain but has most commonly been applied to explorations of normal brain function. This article presents a parcellation of a key area of the motor network, the primary motor cortex (M1), a key area of the motor control network, in adults, typically developing (TD) children and children with ASD and introduces methods for selecting the number of parcels, matching parcels across groups and testing group differences. The parcellation is based solely on patterns of connectivity between individual M1 voxels and all voxels outside of M1, and within all groups, a gross dorsomedial to ventrolateral organization emerged within M1 which was left–right symmetric. Although this gross organizational scheme was present in both groups of children, statistically significant group differences in the size and segregation of M1 parcels within regions of the motor homunculus corresponding to the upper and lower limbs were observed. Qualitative comparison of the M1 parcellation for children with ASD with that of younger and older TD children suggests that these organizational differences, with a lack of differentiation between lower limb/trunk regions and upper limb/hand regions, may be due, at least in part, to a delay in functional specialization within the motor cortex. PMID:23118015

Malaria in Brazil: what happens outside the Amazonian endemic region.

PubMed

de Pina-Costa, Anielle; Brasil, Patrícia; Di Santi, Sílvia Maria; de Araujo, Mariana Pereira; Suárez-Mutis, Martha Cecilia; Santelli, Ana Carolina Faria e Silva; Oliveira-Ferreira, Joseli; Lourenço-de-Oliveira, Ricardo; Daniel-Ribeiro, Cláudio Tadeu

2014-08-01

to be very close to) P. vivax and, in a less extent, by Plasmodium malariae and it is transmitted by the bromeliad mosquito Anopheles (Kerteszia) cruzii. This paper deals mainly with the two profiles of malaria found outside the Amazon: the imported and ensuing introduced cases and the autochthonous cases. We also provide an update regarding the situation in Brazil and the Brazilian endemic Amazon.

Plasmodium falciparum in the southeastern Atlantic forest: a challenge to the bromeliad-malaria paradigm?

PubMed

Laporta, Gabriel Zorello; Burattini, Marcelo Nascimento; Levy, Debora; Fukuya, Linah Akemi; de Oliveira, Tatiane Marques Porangaba; Maselli, Luciana Morganti Ferreira; Conn, Jan Evelyn; Massad, Eduardo; Bydlowski, Sergio Paulo; Sallum, Maria Anice Mureb

2015-04-25

Recently an unexpectedly high prevalence of Plasmodium falciparum was found in asymptomatic blood donors living in the southeastern Brazilian Atlantic forest. The bromeliad-malaria paradigm assumes that transmission of Plasmodium vivax and Plasmodium malariae involves species of the subgenus Kerteszia of Anopheles and only a few cases of P. vivax malaria are reported annually in this region. The expectations of this paradigm are a low prevalence of P. vivax and a null prevalence of P. falciparum. Therefore, the aim of this study was to verify if P. falciparum is actively circulating in the southeastern Brazilian Atlantic forest remains. In this study, anophelines were collected with Shannon and CDC-light traps in seven distinct Atlantic forest landscapes over a 4-month period. Field-collected Anopheles mosquitoes were tested by real-time PCR assay in pools of ten, and then each mosquito from every positive pool, separately for P. falciparum and P. vivax. Genomic DNA of P. falciparum or P. vivax from positive anophelines was then amplified by traditional PCR for sequencing of the 18S ribosomal DNA to confirm Plasmodium species. Binomial probabilities were calculated to identify non-random results of the P. falciparum-infected anopheline findings. The overall proportion of anophelines naturally infected with P. falciparum was 4.4% (21/480) and only 0.8% (4/480) with P. vivax. All of the infected mosquitoes were found in intermixed natural and human-modified environments and most were Anopheles cruzii (22/25 = 88%, 18 P. falciparum plus 4 P. vivax). Plasmodium falciparum was confirmed by sequencing in 76% (16/21) of positive mosquitoes, whereas P. vivax was confirmed in only 25% (1/4). Binomial probabilities suggest that P. falciparum actively circulates throughout the region and that there may be a threshold of the forested over human-modified environment ratio upon which the proportion of P. falciparum-infected anophelines increases significantly. These results

Malaria in Brazil: what happens outside the Amazonian endemic region

PubMed Central

de Pina-Costa, Anielle; Brasil, Patrícia; Santi, Sílvia Maria Di; de Araujo, Mariana Pereira; Suárez-Mutis, Martha Cecilia; Santelli, Ana Carolina Faria e Silva; Oliveira-Ferreira, Joseli; Lourenço-de-Oliveira, Ricardo; Daniel-Ribeiro, Cláudio Tadeu

2014-01-01

(or to be very close to) P. vivax and, in a less extent, by Plasmodium malariae and it is transmitted by the bromeliad mosquito Anopheles (Kerteszia) cruzii. This paper deals mainly with the two profiles of malaria found outside the Amazon: the imported and ensuing introduced cases and the autochthonous cases. We also provide an update regarding the situation in Brazil and the Brazilian endemic Amazon. PMID:25185003

Multiwavelength observations of NaSt1 (WR 122): equatorial mass loss and X-rays from an interacting Wolf-Rayet binary

NASA Astrophysics Data System (ADS)

Mauerhan, Jon; Smith, Nathan; Van Dyk, Schuyler D.; Morzinski, Katie M.; Close, Laird M.; Hinz, Philip M.; Males, Jared R.; Rodigas, Timothy J.

2015-07-01

NaSt1 (aka Wolf-Rayet 122) is a peculiar emission-line star embedded in an extended nebula of [N II] emission with a compact dusty core. The object was previously characterized as a Wolf-Rayet (WR) star cloaked in an opaque nebula of CNO-processed material, perhaps analogous to η Car and its Homunculus nebula, albeit with a hotter central source. To discern the morphology of the [N II] nebula we performed narrow-band imaging using the Hubble Space Telescope and Wide-field Camera 3. The images reveal that the nebula has a disc-like geometry tilted ≈12° from edge-on, composed of a bright central ellipsoid surrounded by a larger clumpy ring. Ground-based spectroscopy reveals radial velocity structure (±10 km s-1) near the outer portions of the nebula's major axis, which is likely to be the imprint of outflowing gas. Near-infrared adaptive-optics imaging with Magellan AO has resolved a compact ellipsoid of Ks-band emission aligned with the larger [N II] nebula, which we suspect is the result of scattered He I line emission (λ2.06 μm). Observations with the Chandra X-ray Observatory have revealed an X-ray point source at the core of the nebula that is heavily absorbed at energies <1 keV and has properties consistent with WR stars and colliding-wind binaries. We suggest that NaSt1 is a WR binary embedded in an equatorial outflow that formed as the result of non-conservative mass transfer. NaSt1 thus appears to be a rare and important example of a stripped-envelope WR forming through binary interaction, caught in the brief Roche lobe overflow phase.

Reconstructing the past outburst history of Eta Carinae from WFPC2 proper motions

NASA Astrophysics Data System (ADS)

Smith, Nathan

2016-10-01

The HST archive contains multiple epochs of WFPC2 images of the nebula around Eta Carinae taken over a 15-year timespan, although only the earliest few years of data have been analyzed and published. The fact that all these images were taken with the same instrument, with the same pixel sampling and field distortion, makes them an invaluable resource for accurately measuring the expanding ejecta. The goal of a previously accepted AR proposal was to analyze the full set of appropriate continuum-filter HST images to place precise constraints on the avereage ejection date of the Homunculus Nebula; this analysis is now complete (Smith et al 2016) and the nebula appears to have been ejected in the second half of 1847. Here we propose to continue this project by constraining the motion of the more extended and much older Outer Ejecta around Eta Carinae. Older material outside the main bipolar nebula traces previous major outbursts of the star with no recorded historical observations. We propose an ambitious reduction and analysis of the complete WFPC2 imaging dataset of Eta Car. These data can reconstruct its violent mass-loss history over the past thousand years. We have already started this by analyzing two epochs of ACS F658N images, and astonishingly, these data suggested two previous eruptions in the 13th and 15th centuries assuming ballistic motion. WFPC2 images will extend the baseline by 10 yr, and critically, more than 2 epochs allow us to measure any deceleration in the ejecta. We will also analyze Doppler shifts in ground-based spectra in order to reconstruct the 3D geometry of past mass ejection. This AR proposal will fund the final year of a PhD thesis.

New whole-body sensory-motor gradients revealed using phase-locked analysis and verified using multivoxel pattern analysis and functional connectivity.

PubMed

Zeharia, Noa; Hertz, Uri; Flash, Tamar; Amedi, Amir

2015-02-18

Topographic organization is one of the main principles of organization in the human brain. Specifically, whole-brain topographic mapping using spectral analysis is responsible for one of the greatest advances in vision research. Thus, it is intriguing that although topography is a key feature also in the motor system, whole-body somatosensory-motor mapping using spectral analysis has not been conducted in humans outside M1/SMA. Here, using this method, we were able to map a homunculus in the globus pallidus, a key target area for deep brain stimulation, which has not been mapped noninvasively or in healthy subjects. The analysis clarifies contradictory and partial results regarding somatotopy in the caudal-cingulate zone and rostral-cingulate zone in the medial wall and in the putamen. Most of the results were confirmed at the single-subject level and were found to be compatible with results from animal studies. Using multivoxel pattern analysis, we could predict movements of individual body parts in these homunculi, thus confirming that they contain somatotopic information. Using functional connectivity, we demonstrate interhemispheric functional somatotopic connectivity of these homunculi, such that the somatotopy in one hemisphere could have been found given the connectivity pattern of the corresponding regions of interest in the other hemisphere. When inspecting the somatotopic and nonsomatotopic connectivity patterns, a similarity index indicated that the pattern of connected and nonconnected regions of interest across different homunculi is similar for different body parts and hemispheres. The results show that topographical gradients are even more widespread than previously assumed in the somatosensory-motor system. Spectral analysis can thus potentially serve as a gold standard for defining somatosensory-motor system areas for basic research and clinical applications. Copyright © 2015 the authors 0270-6474/15/352845-15$15.00/0.

Rotation and Mass Loss

NASA Astrophysics Data System (ADS)

Owocki, S.

2008-06-01

Stellar rotation can play an important role in structuring and enhancing the mass loss from massive stars. Initial 1D models focussed on the expected centrifugal enhancement of the line-driven mass flux from the equator of a rotating star, but the review here emphasizes that the loss of centrifugal support away from the stellar surface actually limits the steady mass flux to just the point-star CAK value, with models near critical rotation characterized by a slow, subcritical acceleration. Recent suggestions that such slow outflows might have high enough density to explain disks in Be or B[e] stars are examined in the context of 2D simulations of the ``Wind Compressed Disk'' (WCD) paradigm, together with a review of the tendency for poleward components of the line-driving force to inhibit WCD formation. When one accounts for equatorial gravity darkening, the net tendency is in fact for the relatively bright regions at higher latitude to drive a faster, denser ``bipolar'' outflow. I discuss the potential relevance for the bipolar form of nebulae from LBV stars like η Carinae, but emphasize that, since the large mass loss associated with the eruption of eta Carinae's Homunculus would heavily saturate line-driving, explaining its bipolar form requires development of analogous models for continuum-driven mass loss. I conclude with a discussion of how radiation seems inherently ill-suited to supporting or driving a geometrically thin, but optically thick disk or disk outflow. The disks inferred in Be and B[e] stars may instead be centrifugally ejected, with radiation inducing an ablation flow from the disk surface, and thus perhaps playing a greater role in destroying (rather than creating) an orbiting, circumstellar disk.

Eta Carinae: An Astrophysical Laboratory to Study Conditions During the Transition Between a Pseudo-Supernova and a Supernova

NASA Astrophysics Data System (ADS)

McKinnon, Darren; Gull, T. R.; Madura, T.

2014-01-01

A major puzzle in the studies of supernovae is the pseudo-supernova, or the near-supernovae state. It has been found to precede, in timespans ranging from months to years, a number of recently-detected distant supernovae. One explanation of these systems is that a member of a massive binary underwent a near-supernova event shortly before the actual supernova phenomenon. Luckily, we have a nearby massive binary, Eta Carinae, that provides an astrophysical laboratory of a near-analog. The massive, highly-eccentric, colliding-wind binary star system survived a non-terminal stellar explosion in the 1800's, leaving behind the incredible bipolar, 10"x20" Homunculus nebula. Today, the interaction of the binary stellar winds 1") is resolvable by the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST). Using HST/STIS, several three-dimensional (3D) data cubes (2D spatial, 1D velocity) have been obtained at selected phases during Eta Carinae's 5.54-year orbital cycle. The data cubes were collected by mapping the central 1-2" at 0.05" intervals with a 52"x0.1" aperture. Selected forbidden lines, that form in the colliding wind regions, provide information on electron density of the shocked regions, the ionization by the hot secondary companion of the primary wind and how these regions change with orbital phase. By applying various analysis techniques to these data cubes, we can compare and measure temporal changes due to the interactions between the two massive winds. The observations, when compared to current 3D hydrodynamic models, provide insight on Eta Carinae's recent mass-loss history, important for determining the current and future states of this likely nearby supernova progenitor.

Imaging Shock Fronts in the Outer Ejecta of Eta Carinae

NASA Astrophysics Data System (ADS)

Smith, Nathan

2017-08-01

Although Eta Car has been imaged many times with HST to monitor the central star and the bright Homunculus Nebula, we propose the first WFC3 imaging of Eta Car to study the more extended Outer Ejecta from previous eruptions. WFC3 has two key filters that have not been used before to image Eta Car, which will provide critical physical information about its eruptive history: (1) F280N with WFC3/UVIS will produce the first Mg II 2800 image of Eta Car, the sharpest image of its complex Outer Ejecta, and will unambiguously trace shock fronts, and (2) F126N with WFC3/IR will sample [Fe II] 12567 arising in the densest post-shock gas. Eta Car is surrounded by a bright, soft X-ray shell seen in Chandra images, which arises from the fastest 1840s ejecta overtaking slower older material. Our recent proper motion measurements show that the outer knots were ejected in two outbursts several hundred years before the 1840s eruption, and spectroscopy of light echoes has recently revealed extremely fast ejecta during the 1840s that indicate an explosive event. Were those previous eruptions explosive as well? If so, were they as energetic, did they also have such fast ejecta, and did they have the same geometry? The structure and excitation of the Outer Ejecta hold unique clues for reconstructing Eta Car's violent mass loss history. The locations of shock fronts in circumstellar material provide critical information, because they identify past discontinuities in the mass loss. This is one of the only ways to investigate the long term (i.e. centuries) evolution and duty cycle of eruptive mass loss in the most massive stars.

The use of transcranial magnetic stimulation to evaluate cortical excitability of lower limb musculature: Challenges and opportunities.

PubMed

Kesar, Trisha M; Stinear, James W; Wolf, Steven L

2018-05-05

Neuroplasticity is a fundamental yet relatively unexplored process that can impact rehabilitation of lower extremity (LE) movements. Transcranial magnetic stimulation (TMS) has gained widespread application as a non-invasive brain stimulation technique for evaluating neuroplasticity of the corticospinal pathway. However, a majority of TMS studies have been performed on hand muscles, with a paucity of TMS investigations focused on LE muscles. This perspective review paper proposes that there are unique methodological challenges associated with using TMS to evaluate corticospinal excitability of lower limb muscles. The challenges include: (1) the deeper location of the LE motor homunculus; (2) difficulty with targeting individual LE muscles during TMS; and (3) differences in corticospinal circuity controlling upper and lower limb muscles. We encourage future investigations that modify traditional methodological approaches to help address these challenges. Systematic TMS investigations are needed to determine the extent of overlap in corticomotor maps for different LE muscles. A simple, yet informative methodological solution involves simultaneous recordings from multiple LE muscles, which will provide the added benefit of observing how other relevant muscles co-vary in their responses during targeted TMS assessment directed toward a specific muscle. Furthermore, conventionally used TMS methods (e.g., determination of hot spot location and motor threshold) may need to be modified for TMS studies involving LE muscles. Additional investigations are necessary to determine the influence of testing posture as well as activation state of adjacent and distant LE muscles on TMS-elicited responses. An understanding of these challenges and solutions specific to LE TMS will improve the ability of neurorehabilitation clinicians to interpret TMS literature, and forge novel future directions for neuroscience research focused on elucidating neuroplasticity processes underlying

Depicting the inner and outer nose: the representation of the nose and the nasal mucosa on the human primary somatosensory cortex (SI).

PubMed

Gastl, Mareike; Brünner, Yvonne F; Wiesmann, Martin; Freiherr, Jessica

2014-09-01

The nose is important not only for breathing, filtering air, and perceiving olfactory stimuli. Although the face and hands have been mapped, the representation of the internal and external surface of the nose on the primary somatosensory cortex (SI) is still poorly understood. To fill this gap functional magnetic resonance imaging (fMRI) was used to localize the nose and the nasal mucosa in the Brodman areas (BAs) 3b, 1, and 2 of the human postcentral gyrus (PG). Tactile stimulation during fMRI was applied via a customized pneumatically driven device to six stimulation sites: the alar wing of the nose, the lateral nasal mucosa, and the hand (serving as a reference area) on the left and right side of the body. Individual representations could be discriminated for the left and right hand, for the left nasal mucosa and left alar wing of the nose in BA 3b and BA 1 by comparing mean activation maxima and Euclidean distances. Right-sided nasal conditions and conditions in BA 2 could further be separated by different Euclidean distances. Regarding the alar wing of the nose, the results concurred with the classic sensory homunculus proposed by Penfield and colleagues. The nasal mucosa was not only determined an individual and bilateral representation, its position on the somatosensory cortex is also situated closer to the caudal end of the PG compared to that of the alar wing of the nose and the hand. As SI is commonly activated during the perception of odors, these findings underscore the importance of the knowledge of the representation of the nasal mucosa on the primary somatosensory cortex, especially for interpretation of results of functional imaging studies about the sense of smell. Copyright © 2014 Wiley Periodicals, Inc.

Evolution, immunity and the emergence of brain superautoantigens

PubMed Central

Nataf, Serge

2017-01-01

While some autoimmune disorders remain extremely rare, others largely predominate the epidemiology of human autoimmunity. Notably, these include psoriasis, diabetes, vitiligo, thyroiditis, rheumatoid arthritis and multiple sclerosis. Thus, despite the quasi-infinite number of "self" antigens that could theoretically trigger autoimmune responses, only a limited set of antigens, referred here as superautoantigens, induce pathogenic adaptive responses. Several lines of evidence reviewed in this paper indicate that, irrespective of the targeted organ (e.g. thyroid, pancreas, joints, brain or skin), a significant proportion of superautoantigens are highly expressed in the synaptic compartment of the central nervous system (CNS). Such an observation applies notably for GAD65, AchR, ribonucleoproteins, heat shock proteins, collagen IV, laminin, tyrosine hydroxylase and the acetylcholinesterase domain of thyroglobulin. It is also argued that cognitive alterations have been described in a number of autoimmune disorders, including psoriasis, rheumatoid arthritis, lupus, Crohn's disease and autoimmune thyroiditis. Finally, the present paper points out that a great majority of the "incidental" autoimmune conditions notably triggered by neoplasms, vaccinations or microbial infections are targeting the synaptic or myelin compartments. On this basis, the concept of an immunological homunculus, proposed by Irun Cohen more than 25 years ago, is extended here in a model where physiological autoimmunity against brain superautoantigens confers both: i) a crucial evolutionary-determined advantage via cognition-promoting autoimmunity; and ii) a major evolutionary-determined vulnerability, leading to the emergence of autoimmune disorders in Homo sapiens. Moreover, in this theoretical framework, the so called co-development/co-evolution model, both the development (at the scale of an individual) and evolution (at the scale of species) of the antibody and T-cell repertoires are coupled to

Glacier Changes in the Nanga Parbat Region, NW Himalaya: A longitudinal study over 160 years (1856-2016)

NASA Astrophysics Data System (ADS)

Nüsser, Marcus; Schmidt, Susanne

2017-04-01

Against the background of the prominent Himalayan glacier debate of the past decade, global concerns were raised about the severe consequences of detected and expected changes in the South Asian cryosphere. Due to the lack of historical glaciological data in the Himalayan region, studies of glacier changes over long time periods are rare. The present study seeks to analyze and quantify glacier changes in the Nanga Parbat region between 1856 and 2016. Due to the steep topography and great vertical span, the debris-covered glaciers of the mountain massif are largely fed by avalanches of different size. This impact of snow and ice re-distribution by avalanches is often neglected in glacier mass-balances. Therefore, an integrated approach was used to investigate the glacier changes and the impact of avalanches. This approach includes (1) a re-photographic survey with images from several expeditions between 1934 and 2010, (2) mapping during own field surveys between 1992 and 2010, as well as (3) the analyses of remote sensing data (Corona, QuickBird, KompSat, Landsat, etc. and DEM) and (4) historical topographic maps. The re-photographic survey allows for direct comparisons and illustrates glacier changes over a span of seventy years. Changes of glacier lengths were quantified by using remote sensing data and the topographic map of 1934. In order to calculate glacier surface changes, a digital elevation model (DEM) with a spatial resolution of 30 x 30 m2 was derived from the digitized contour lines of the topographic map from 1934 and compared to SRTM-DEM (30 x 30 m2) and ALOS-DSM. Based on remote sensing time-series, avalanche deposits on glaciers were mapped in order to identify their magnitude and frequencies. To calculate the potential glacier catchment, area of steep rock walls and the ratio between accumulation and ablation zones were calculated for each glacier basin. Our field based investigations show that the glaciers in the Rupal Valley are characterized by

Mapping and Modeling the Extended Winds of the Massive Interacting Binary, Eta Carinae

NASA Technical Reports Server (NTRS)

Gull, Ted

2010-01-01

The combination HST/STIS high spatial and moderate spectral resolutions have revealed the massive interacting wind structure of Eta Carinae by forbidden lines of singly and doubly ionized elements. Throughout the 5.54-year period, lines of Fe++, Ne++, Ar++, S++ and N+ reveal the interacting wind structures, near critical electron densities of 10(exp 5) to 3 x 10(exp 7)cu cm, photoionized by the hot secondary, Eta Car B, Lines of Fe+ and Ni+ trace the denser (>10(exp 7)cu cm. less-ionized (< 8 eV) primary wind of Eta Car A as it wraps around the interacting binary stars. For 5 years of the 5.54 year period, the FUV radiation from Eta Car B escapes the orbital region, ionizing the boundaries of the expanding wind structures. But for three to six months, Eta Car B plunges into the primary wind approaching to within 1 to 2 AU, leading to cutoff of FUV and X-ray fluxes. The interacting wind structure, resolved out to 0.8", drops io ionization and then rebuilds as Eta Car B emerges from the primary wind envelope. Solid Particle Hydrodynamical(SPH) models have been developed extending out to 2000 AU and adapted to include FUV radiation effects of the winds. In turn, synthetic spectroimages of selected forbidden lines have been constructed and compared to the spectroimages recorded by the HST/STIS throughout 1998.0 to 2004.3, extending across the 1998 and 2003.5 minima. By this method, we show that the orbital axis of the binary system must bc within 15 degrees of the Homunculus axis of symmetry and that periastron occurs with Eta Car B passing on the far side of Eta Car B. This result ties the current binary orbit with the bipolar ejection with intervening skirt and leads to implications that the binary system influenced the mass ejection of the l840s and the lesser ejection of the 1890s.

DISCOVERY OF PRECURSOR LUMINOUS BLUE VARIABLE OUTBURSTS IN TWO RECENT OPTICAL TRANSIENTS: THE FITFULLY VARIABLE MISSING LINKS UGC 2773-OT AND SN 2009ip

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Nathan; Miller, Adam; Li Weidong

2010-04-15

We present progenitor-star detections, light curves, and optical spectra of supernova (SN) 2009ip and the 2009 optical transient in UGC 2773 (U2773-OT), which were not genuine SNe. Precursor variability in the decade before outburst indicates that both of the progenitor stars were luminous blue variables (LBVs). Their pre-outburst light curves resemble the S Doradus phases that preceded giant eruptions of the prototypical LBVs {eta} Carinae and SN 1954J (V12 in NGC 2403), with intermediate progenitor luminosities. Hubble Space Telescope detections a decade before discovery indicate that the SN 2009ip and U2773-OT progenitors were supergiants with likely initial masses of 50-80more » M {sub sun} and {approx}>20 M {sub sun}, respectively. Both outbursts had spectra befitting known LBVs, although in different physical states. SN 2009ip exhibited a hot LBV spectrum with characteristic speeds of 550 km s{sup -1}, plus evidence for faster material up to 5000 km s{sup -1}, resembling the slow Homunculus and fast blast wave of {eta} Carinae. In contrast, U2773-OT shows a forest of narrow absorption and emission lines comparable to that of S Dor in its cool state, plus [Ca II] emission and an infrared excess indicative of dust, similar to SN 2008S and the 2008 optical transient in NGC 300 (N300-OT). The [Ca II] emission is probably tied to a dusty pre-outburst environment, and is not a distinguishing property of the outburst mechanism. The LBV nature of SN 2009ip and U2773-OT may provide a critical link between historical LBV eruptions, while U2773-OT may provide a link between LBVs and the unusual dust-obscured transients SN 2008S and N300-OT. Future searches will uncover more examples of precursor LBV variability of this kind, providing key clues that may help unravel the instability driving LBV eruptions in massive stars.« less

Quantifying the three-dimensional facial morphology of the laboratory rat with a focus on the vibrissae

PubMed Central

2018-01-01

The morphology of an animal’s face will have large effects on the sensory information it can acquire. Here we quantify the arrangement of cranial sensory structures of the rat, with special emphasis on the mystacial vibrissae (whiskers). Nearly all mammals have vibrissae, which are generally arranged in rows and columns across the face. The vibrissae serve a wide variety of important behavioral functions, including navigation, climbing, wake following, anemotaxis, and social interactions. To date, however, there are few studies that compare the morphology of vibrissal arrays across species, or that describe the arrangement of the vibrissae relative to other facial sensory structures. The few studies that do exist have exploited the whiskers’ grid-like arrangement to quantify array morphology in terms of row and column identity. However, relying on whisker identity poses a challenge for comparative research because different species have different numbers and arrangements of whiskers. The present work introduces an approach to quantify vibrissal array morphology regardless of the number of rows and columns, and to quantify the array’s location relative to other sensory structures. We use the three-dimensional locations of the whisker basepoints as fundamental parameters to generate equations describing the length, curvature, and orientation of each whisker. Results show that in the rat, whisker length varies exponentially across the array, and that a hard limit on intrinsic curvature constrains the whisker height-to-length ratio. Whiskers are oriented to “fan out” approximately equally in dorsal-ventral and rostral-caudal directions. Quantifying positions of the other sensory structures relative to the whisker basepoints shows remarkable alignment to the somatosensory cortical homunculus, an alignment that would not occur for other choices of coordinate systems (e.g., centered on the midpoint of the eyes). We anticipate that the quantification of facial

The origins of metamodality in visual object area LO: Bodily topographical biases and increased functional connectivity to S1

PubMed Central

Tal, Zohar; Geva, Ran; Amedi, Amir

2016-01-01

Recent evidence from blind participants suggests that visual areas are task-oriented and sensory modality input independent rather than sensory-specific to vision. Specifically, visual areas are thought to retain their functional selectivity when using non-visual inputs (touch or sound) even without having any visual experience. However, this theory is still controversial since it is not clear whether this also characterizes the sighted brain, and whether the reported results in the sighted reflect basic fundamental a-modal processes or are an epiphenomenon to a large extent. In the current study, we addressed these questions using a series of fMRI experiments aimed to explore visual cortex responses to passive touch on various body parts and the coupling between the parietal and visual cortices as manifested by functional connectivity. We show that passive touch robustly activated the object selective parts of the lateral–occipital (LO) cortex while deactivating almost all other occipital–retinotopic-areas. Furthermore, passive touch responses in the visual cortex were specific to hand and upper trunk stimulations. Psychophysiological interaction (PPI) analysis suggests that LO is functionally connected to the hand area in the primary somatosensory homunculus (S1), during hand and shoulder stimulations but not to any of the other body parts. We suggest that LO is a fundamental hub that serves as a node between visual-object selective areas and S1 hand representation, probably due to the critical evolutionary role of touch in object recognition and manipulation. These results might also point to a more general principle suggesting that recruitment or deactivation of the visual cortex by other sensory input depends on the ecological relevance of the information conveyed by this input to the task/computations carried out by each area or network. This is likely to rely on the unique and differential pattern of connectivity for each visual area with the rest of the

The wind-wind collision hole in eta Car

NASA Astrophysics Data System (ADS)

Damineli, A.; Teodoro, M.; Richardson, N. D.; Gull, T. R.; Corcoran, M. F.; Hamaguchi, K.; Groh, J. H.; Weigelt, G.; Hillier, D. J.; Russell, C.; Moffat, A.; Pollard, K. R.; Madura, T. I.

2017-11-01

Eta Carinae is one of the most massive observable binaries. Yet determination of its orbital and physical parameters is hampered by obscuring winds. However the effects of the strong, colliding winds changes with phase due to the high orbital eccentricity. We wanted to improve measures of the orbital parameters and to determine the mechanisms that produce the relatively brief, phase-locked minimum as detected throughout the electromagnetic spectrum. We conducted intense monitoring of the He ii λ4686 line in η Carinae for 10 months in the year 2014, gathering ~300 high S/N spectra with ground- and space-based telescopes. We also used published spectra at the FOS4 SE polar region of the Homunculus, which views the minimum from a different direction. We used a model in which the He ii λ4686 emission is produced by two mechanisms: a) one linked to the intensity of the wind-wind collision which occurs along the whole orbit and is proportional to the inverse square of the separation between the companion stars; and b) the other produced by the `bore hole' effect which occurs at phases across the periastron passage. The opacity (computed from 3D SPH simulations) as convolved with the emission reproduces the behavior of equivalent widths both for direct and reflected light. Our main results are: a) a demonstration that the He ii λ4686 light curve is exquisitely repeatable from cycle to cycle, contrary to previous claims for large changes; b) an accurate determination of the longitude of periastron, indicating that the secondary star is `behind' the primary at periastron, a dispute extended over the past decade; c) a determination of the time of periastron passage, at ~4 days after the onset of the deep light curve minimum; and d) show that the minimum is simultaneous for observers at different lines of sight, indicating that it is not caused by an eclipse of the secondary star, but rather by the immersion of the wind-wind collision interior to the inner wind of the

Biggest Star in Our Galaxy Sits within a Rugby-Ball Shaped Cocoon

NASA Astrophysics Data System (ADS)

2003-11-01

VLT Interferometer Gives Insight Into the Shape of Eta Carinae Summary Ever since 1841, when the until then inconspicuous southern star Eta Carinae underwent a spectacular outburst, astronomers have wondered what exactly is going on in this unstable giant star. However, due to its considerable distance - 7,500 light-years - details of the star itself were beyond observation. This star is known to be surrounded by the Homunculus Nebula , two mushroom-shaped clouds ejected by the star, each of which is hundreds of times larger than our solar system. Now, for the first time, infrared interferometry with the VINCI instrument on ESO's Very Large Telescope Interferometer (VLTI) enabled an international team of astronomers [1] to zoom-in on the inner part of its stellar wind. For Roy van Boekel , leader of the team, these results indicate that " the wind of Eta Carinae turns out to be extremely elongated and the star itself is highly unstable because of its fast rotation." PR Photo 32a/03 : The Immediate Surroundings of Eta Carinae (NAOS-CONICA/YEPUN). PR Photo 32b/03 : The Highly Unstable Star Eta Carinae (Artist's Impression) A monster in the southern sky ESO PR Photo 32a/03 ESO PR Photo 32a/03 [Preview - JPEG: 549 x 400 pix - 60k [Normal - JPEG: 1098 x 800 pix - 566k] Caption : The image to the left in PR Photo 32a/03 shows the mushroom-shaped clouds, known as the Homunculus Nebula , that surround the massive star Eta Carinae (Credit: NASA/ESA HST). To the right is an image obtained with the VLT NACO adaptive-optics camera that reveals the structure of the star's immediate surroundings. The central region displays a complex morphology of luminous objects. Eta Carinae , the most luminous star known in our Galaxy, is by all standards a real monster: it is 100 times more massive than our Sun and 5 million times as luminous. This star has now entered the final stage of its life and is highly unstable. It undergoes giant outbursts from time to time; one of the most recent

The Strings of Eta Carina: The HST/STIS Spectra and [Ca II

NASA Technical Reports Server (NTRS)

Melendez, M. B.; Gull, T. R.; Bautista, M. A.; Badnell, N. R.

2006-01-01

Long linear, filamentary ejecta, are found to move at very high velocity external to the Homunculus, the circumstellar hourglass-shaped ejecta surrounding Eta Carinae. The origin of the strings is a puzzle. As an example, the Weigelt Blobs have N at 10X solar and C, O at 0.01X solar abundance, along with He/H significantly enhanced. This abundance pattern is evidence for extreme CNO-processing. Similarly, the Strontium Filament has Ti/Ni at 100X solar, presumably due to the lack of oxygen to form Ti-oxide precipitates onto dust grains. We have obtained 2-D spectra with the HST/STIS of the Strontium Filament and a portion of a string. These deep spectral exposures, at moderate dispersion, span much of the near red spectral region from 5000 to 9000A. We have identified twelve emission lines in these spectra with proper velocities and spatial structure of this string and obtained line ratios for [Ca II] (7293/7325A) and [Fe Ill (7157/8619A) which are useful for determining physical conditions in this nebulosity. In an attempt to use the [Ca II] ratio to determine the physical parameters, and ultimately the abundances in the strings, we have constructed a statistical equilibrium model for Ca II , including radiative and collisional rates. These results incorporate our newly calculated atomic data for levels n = 3,4,5 and 6 configurations of Ca II. The aim is to compute the [Ca II] line ratios and use them as a diagnostic of the physical parameters. Using the [Fe II] ratio we find that for Te=10,000 K, the electron density is Ne approx.10(exp 6)/cu cm. We plan to use the [Ca II] ratio to confirm this result. Then, we will extend the use of this multilevel model Ca II atom to study the physical conditions of the Strontium filament where eight lines of Ca II, both allowed and forbidden, had been identified. With the physical conditions determined, we will be able to derive reliable estimates for the gas phase abundances in the strings.

Neotropics provide insights into the emergence of New World monkeys: New dental evidence from the late Oligocene of Peruvian Amazonia.

PubMed

Marivaux, Laurent; Adnet, Sylvain; Altamirano-Sierra, Ali J; Boivin, Myriam; Pujos, François; Ramdarshan, Anusha; Salas-Gismondi, Rodolfo; Tejada-Lara, Julia V; Antoine, Pierre-Olivier

2016-08-01

Recent field efforts in Peruvian Amazonia (Contamana area, Loreto Department) have resulted in the discovery of a late Oligocene (ca. 26.5 Ma; Chambira Formation) fossil primate-bearing locality (CTA-61). In this paper, we analyze the primate material consisting of two isolated upper molars, the peculiar morphology of which allows us to describe a new medium-sized platyrrhine monkey: Canaanimico amazonensis gen. et sp. nov. In addition to the recent discovery of Perupithecus ucayaliensis, a primitive anthropoid taxon of African affinities from the alleged latest Eocene Santa Rosa locality (Peruvian Amazonia), the discovery of Canaanimico adds to the evidence that primates were well-established in the Amazonian Basin during the Paleogene. Our phylogenetic results based on dental evidence show that none of the early Miocene Patagonian taxa (Homunculus, Carlocebus, Soriacebus, Mazzonicebus, Dolichocebus, Tremacebus, and Chilecebus), the late Oligocene Bolivian Branisella, or the Peruvian Canaanimico, is nested within a crown platyrrhine clade. All these early taxa are closely related and considered here as stem Platyrrhini. Canaanimico is nested within the Patagonian Soriacebinae, and closely related to Soriacebus, thereby extending back the soriacebine lineage to 26.5 Ma. Given the limited dental evidence, it is difficult to assess if Canaanimico was engaged in a form of pitheciine-like seed predation as is observed in Soriacebus and Mazzonicebus, but dental microwear patterns recorded on one upper molar indicate that Canaanimico was possibly a fruit and hard-object eater. If Panamacebus, a recently discovered stem cebine from the early Miocene of Panama, indicates that the crown platyrrhine radiation was already well underway by the earliest Miocene, Canaanimico indicates in turn that the "homunculid" radiation (as a part of the stem radiation) was well underway by the late Oligocene. These new data suggest that the stem radiation likely occurred in the Neotropics

Representational Similarity of Body Parts in Human Occipitotemporal Cortex.

PubMed

Bracci, Stefania; Caramazza, Alfonso; Peelen, Marius V

2015-09-23

Regions in human lateral and ventral occipitotemporal cortices (OTC) respond selectively to pictures of the human body and its parts. What are the organizational principles underlying body part responses in these regions? Here we used representational similarity analysis (RSA) of fMRI data to test multiple possible organizational principles: shape similarity, physical proximity, cortical homunculus proximity, and semantic similarity. Participants viewed pictures of whole persons, chairs, and eight body parts (hands, arms, legs, feet, chests, waists, upper faces, and lower faces). The similarity of multivoxel activity patterns for all body part pairs was established in whole person-selective OTC regions. The resulting neural similarity matrices were then compared with similarity matrices capturing the hypothesized organizational principles. Results showed that the semantic similarity model best captured the neural similarity of body parts in lateral and ventral OTC, which followed an organization in three clusters: (1) body parts used as action effectors (hands, feet, arms, and legs), (2) noneffector body parts (chests and waists), and (3) face parts (upper and lower faces). Whole-brain RSA revealed, in addition to OTC, regions in parietal and frontal cortex in which neural similarity was related to semantic similarity. In contrast, neural similarity in occipital cortex was best predicted by shape similarity models. We suggest that the semantic organization of body parts in high-level visual cortex relates to the different functions associated with the three body part clusters, reflecting the unique processing and connectivity demands associated with the different types of information (e.g., action, social) different body parts (e.g., limbs, faces) convey. Significance statement: While the organization of body part representations in motor and somatosensory cortices has been well characterized, the principles underlying body part representations in visual cortex

Effects of the LBV Primary's Mass-loss Rate on the 3D Hydrodynamics of eta Carinae's Colliding Winds

NASA Technical Reports Server (NTRS)

Madura, Thomas I.; Gull, Theodore R.; Cocoran, M.; Okazaki, A.; Owocki, S.; Russell, C.; Hamaguchi, K.; Clementel, N; Groh, J.; Hillier, D. J.

2013-01-01

At the heart of eta Carinae's spectacular "Homunculus" nebula lies an extremely luminous (L(sub Total) greater than approximately 5 × 10(exp 6) solar luminosity) colliding wind binary with a highly eccentric (e approximately 0.9), 5.54-year orbit (Figure 1). The primary of the system, a Luminous Blue Variable (LBV), is our closest (D approximately 2.3 kpc) and best example of a pre-hypernova or pre-gamma ray burst environment. The remarkably consistent and periodic RXTE X-ray light curve surprisingly showed a major change during the system's last periastron in 2009, with the X-ray minimum being approximately 50% shorter than the minima of the previous two cycles1. Between 1998 and 2011, the strengths of various broad stellar wind emission lines (e.g. Halpha, Fe II) in line-of-sight (l.o.s.) also decreased by factors of 1.5 - 3 relative to the continuum2. The current interpretation for these changes is that they are due to a gradual factor of 2 - 4 drop in the primary's mass-loss rate over the last approximately 15 years1, 2. However, while a secular change is seen for a direct view of the central source, little to no change is seen in profiles at high stellar latitudes or reflected off of the dense, circumbinary material known as the "Weigelt blobs"2, 3. Moreover, model spectra generated with CMFGEN predict that a factor of 2 - 4 drop in the primary's mass-loss rate should lead to huge changes in the observed spectrum, which thus far have not been seen. Here we present results from large- (plus or minus 1620 AU) and small- (plus or minus 162 AU) domain, full 3D smoothed particle hydrodynamics (SPH) simulations of eta Car's massive binary colliding winds for three different primary-star mass-loss rates (2.4, 4.8, and 8.5 × 10(exp -4) solar mass/yr). The goal is to investigate how the mass-loss rate affects the 3D geometry and dynamics of eta Car's optically-thick wind and spatially-extended wind-wind collision (WWC) regions, both of which are known sources of

On the Nature of the Prototype Luminous Blue Variable Ag Carinae. I. Fundamental Parameters During Visual Minimum Phases and Changes in the Bolometric Luminosity During the S-Dor Cycle

NASA Astrophysics Data System (ADS)

Groh, J. H.; Hillier, D. J.; Damineli, A.; Whitelock, P. A.; Marang, F.; Rossi, C.

2009-06-01

We present a detailed spectroscopic analysis of the luminous blue variable (LBV) AG Carinae (AG Car) during the last two visual minimum phases of its S-Dor cycle (1985-1990 and 2000-2003). The analysis reveals an overabundance of He, N, and Na, and a depletion of H, C, and O, on the surface of the AG Car, indicating the presence of a CNO-processed material. Furthermore, the ratio N/O is higher on the stellar surface than in the nebula. We found that the minimum phases of AG Car are not equal to each other, since we derived a noticeable difference between the maximum effective temperature achieved during 1985-1990 (22, 800 K) and 2000-2001 (17,000 K). Significant differences between the wind parameters in these two epochs were also noticed. While the wind terminal velocity was 300 km s-1 in 1985-1990, it was as low as 105 km s-1 in 2001. The mass-loss rate, however, was lower from 1985-1990 (1.5 × 10-5 M sun yr-1) than from 2000-2001 (3.7 × 10-5 M sun yr-1). We found that the wind of AG Car is significantly clumped (f sime 0.10-0.25) and that clumps must be formed deep in the wind. We derived a bolometric luminosity of 1.5 × 106 L sun during both minimum phases which, contrary to the common assumption, decreases to 1.0 × 106 L sun as the star moves toward the maximum flux in the V band. Assuming that the decrease in the bolometric luminosity of AG Car is due to the energy used to expand the outer layers of the star, we found that the expanding layers contain roughly 0.6-2 M sun. Such an amount of mass is an order of magnitude lower than the nebular mass around AG Car, but is comparable to the nebular mass found around lower-luminosity LBVs and to that of the Little Homunculus of Eta Car. If such a large amount of mass is indeed involved in the S Dor-type variability, we speculate that such instability could be a failed Giant Eruption, with several solar masses never becoming unbound from the star. Based on observations made with the 1.6 m telescope at the

Preview of a Forthcoming Supernova

NASA Image and Video Library

2017-12-08

continued to vary in brightness ever since, and while it is once again visible to the naked eye on a dark night, it has never again come close to its peak of 1843. NASA's Hubble Telescope captured an image of Eta Carinae. This image consists of ultraviolet and visible light images from the High Resolution Channel of Hubble's Advanced Camera for Surveys. The field of view is approximately 30 arcseconds across. The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star. Although 19th century astronomers did not have telescopes powerful enough to see the 1843 outburst in detail, its effects can be studied today. The huge clouds of matter thrown out a century and a half ago, known as the Homunculus Nebula, have been a regular target for Hubble since its launch in 1990. This image, taken with the Advanced Camera for Surveys High Resolution Channel, is the most detailed yet, and shows how the material from the star was not thrown out in a uniform manner, but forms a huge dumbbell shape. Eta Carinae is not only interesting because of its past, but also because of its future. It is one of the closest stars to Earth that is likely to explode in a supernova in the relatively near future (though in astronomical timescales the "near future" could still be a million years away). When it does, expect an impressive view from Earth, far brighter still than its last outburst: SN 2006gy, the brightest supernova ever observed, came from a star of the same type, though from a galaxy over 200 million light-years away. Credit: ESA/NASA More information: www.spacetelescope.org/images/potw1208a/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific

A Great Moment for Astronomy

NASA Astrophysics Data System (ADS)

1998-05-01

extremely efficiently. 4. Fine Structure of the Butterfly Nebula This beautiful colour picture is a composite of three exposures through broad-band blue, green and red filters, lasting a total of 25 minutes. It shows the great complexity of this planetary nebula. It also demonstrates the exceptional efficiency with which features of faint surface brightness can be recorded with the VLT . Strong radiation from a dying star in a binary system at the centre impacts on the surrounding material that has been thrown out earlier from the system. 5) High-velocity Ejecta in Eta Carinae This fine picture was obtained during an exposure lasting only 10 seconds. It shows fine structures around this very active object in a detail never before achieved with any ground-based telescope . In the lower insert, a short exposure of the central Homunculus Nebula (seeing 0.38 arcsec) provides a clear view of the three-dimensional structure of this bipolar object. 6. The Dust Band in Centaurus A An amazing amount of faint details is shown in this high-resolution exposure (0.49 arcsec) of the central dust band in the nearby, southern galaxy Centaurus A, obtained through a broad-band red filter and lasting only 10 seconds. The VLT Unit Telescopes will be able to image many other galaxies in similar detail. 7. The Energetic Jet in Messier 87 The First Light took place during the night of May 25 - 26, 1998. Following a short interval of reasonable observing conditions, less optimal atmospheric conditions were encountered. The present photo, a three-colour composite (ultraviolet, blue, green) of the central region of the giant elliptical galaxy Messier 87 in the Virgo Cluster, was obtained during this night. 8. Total Optical Control The 8.2-m main and the 1.1-m secondary mirrors of the VLT Unit Telescopes are completely computer-controlled by means of an Active Optics system. In this way, the shape of the mirror can be optimized very quickly for a given observational purpose. This sequence of 9 images

Giant Eyes for the VLT Interferometer

NASA Astrophysics Data System (ADS)

2001-11-01

.04 mas (6 data sets), respectively. The diameter of Zeta Geminorum has been measured before by three different interferometers. Its diameter is expected to vary between about 1.5 mas and 1.8 mas within ten days. On the date the VLTI data was taken, its phase was close to the foreseen maximum diameter. Beta Doradus has never been measured before. * The red giant Psi Phoenicis was measured on two nights (16 data sets) with the UTs for three different positions in the sky, hence with three different projected baselines. Some weeks earlier it had been measured on four nights with the 40-cm test siderostats (8 data sets) on a shorter 16-m baseline. The star was well resolved already in the previous measurements, but the addition of the data recently obtained with the UTs is of fundamental importance because with their longer baseline and larger light-gathering power, it now becomes possible to obtain visibility measurements beyond the first null, cf. PR Photo 30e/01 . Such measurements in the future will enable astronomers to measure fine details such as limb-darkening and deviations from spherical symmetry. The preliminary diameter value for this star is 8.21 ± 0.02 mas. * The enigmatic object Eta Carinae is a luminous blue variable, a supermassive star, which underwent a massive outburst in the 1840's. This outburst was responsible for the creation of the surrounding Homunculus Nebula . The central object is not well understood, but is likely to have a complex structure and therefore the first interferometric measurement with the VLTI is of great importance. Fringes with a low contrast (amplitude of about 20%) were detected, indicating that the central object is resolved on a scale of a few milliarcseconds. More observations will be obtained to further investigate this peculiar object.