The Two Modes of Visual Processing: Implications for Spatial Orientation

The roles of the focal and ambient visual systems in spatial orientation are discussed. The two modes are defined and compared. The contribution of each system is illustrated through examples such as spatial disorientation/motion sickness, vehicle guidance/night driving, visual narrowing under stress/cortical brain damage, and aircraft instrumentation. Emphasis is placed on the need for testing procedures for the ambient system

Hypothalamic Α 2 -Noradrenergic Receptor System Relation to Dietary, Genetic, and Hormonally Induced Obesity

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73970/1/j.1749-6632.1989.tb53313.x.pd

The impact of component performance on the overall cycle performance of small-scale low temperature organic Rankine cycles

Low temperature organic Rankine cycles offer a promising technology for the generation of power from low temperature heat sources. Small-scale systems (~10kW) are of significant interest, however there is a current lack of commercially viable expanders. For a potential expander to be economically viable for small-scale applications it is reasonable to assume that the same expander must have the ability to be implemented within a number of different ORC applications. It is therefore important to design and optimise the cycle considering the component performance, most notably the expander, both at different thermodynamic conditions, and using alternative organic fluids. This paper demonstrates a novel modelling methodology that combines a previously generated turbine performance map with cycle analysis to establish at what heat source conditions optimal system performance can be achieved using an existing turbine design. The results obtained show that the same turbine can be effectively utilised within a number of different ORC applications by changing the working fluid. By selecting suitable working fluids, this turbine can be used to convert pressurised hot water at temperatures between 360K and 400K, and mass flow rates between 0.45kg/s and 2.7kg/s, into useful power with outputs between 1.5kW and 27kW. This is a significant result since it allows the same turbine to be implemented into a variety of applications, improving the economy of scale. This work has also confirmed the suitability of the candidate turbine for a range of low temperature ORC applications

Asteroseismological Observations of the Central Star of the Planetary Nebula NGC 1501

We report on a global CCD time-series photometric campaign to decode the pulsations of the nucleus of the planetary nebula NGC1501. The star is hot and hydrogen-deficient, similar to the pre-white-dwarf PG 1159 stars. NGC1501 shows pulsational brightness variations of a few percent with periods ranging from 19 to 87 minutes. The variations are very complex, suggesting a pulsation spectrum that requires a long unbroken time series to resolve. Our CCD photometry of the star covers a two-week period in 1991 November, and used a global network of observatories. We obtained nearly continuous coverage over an interval of one week in the middle of the run. We have identified 10 pulsation periods, ranging from 5235 s down to 1154 s. We find strong evidence that the modes are indeed nonradial g-modes. The ratios of the frequencies of the largest-amplitude modes agree with those expected for modes that are trapped by a density discontinuity in the outer layers. We offer a model for the pulsation spectrum that includes a common period spacing of 22.3 s and a rotation period of 1.17 days; the period spacing allows us to assign a seismological mass of 0.55+/-0.03 Msun.Comment: 12 pages, AASTEX, 7 tables, 6 EPS figures, to appear in AJ, 12/96 Corrected version repairs table formatting and adds missing Table

Comparison of Clinical and Epidemiologic Characteristics of Young Febrile Infants with and without SARS-CoV-2 Infection.

OBJECTIVE: To determine features that distinguish febrile young infants with SARS-CoV-2 infection. STUDY DESIGN: Retrospective single-center study included febrile infantsChildren\u27s Medical Center of Northwell Health, New Hyde Park, New York during March 1-April 30 of 2018, 2019, and 2020. Sociodemographic and clinical features were compared between those seen during the 2020 COVID-19 pandemic and previous years, as well as between SARS-CoV-2 infected infants and SARS-CoV-2 uninfected infants (SARS-CoV-2 negative or evaluated during 2018 and 2019). RESULTS: In all, 124 febrile infantsidentified; 38 during the 2-month study period in 2018, 33 in 2019, and 53 in 2020. During 2020, fewer febrile infants had a serious bacterial infection (SBI) or a positive respiratory viral panel (RVP) than in prior years (6% versus 21%, P = .02; 15% versus 53%, p CONCLUSIONS: During the peak of the pandemic, SARS-CoV-2 was the predominant pathogen among febrile infants. Socioeconomic, historical, and laboratory features differed significantly between SARS-CoV-2 infected and uninfected infants. None of the 20 infants with SARS-CoV-2 infection had an identified co-viral or serious bacterial infection

The 69 ms Radio Pulsar Near the Supernova Remnant RCW 103

We report the detection of the radio pulsar counterpart to the 69 ms X-ray pulsar discovered near the supernova remnant RCW 103 (G332.4-0.4). Our detection confirms that the pulsations arise from a rotation-powered neutron star, which we name PSR J1617-5055. The observed barycentric period derivative confirms that the pulsar has a characteristic age of only 8 kyr, the sixth smallest of all known pulsars. The unusual apparent youth of the pulsar and its proximity to a young remnant requires that an association be considered. Although the respective ages and distances are consistent within substantial uncertainties, the large inferred pulsar transverse velocity is difficult to explain given the observed pulsar velocity distribution, the absence of evidence for a pulsar wind nebula, and the symmetry of the remnant. Rather, we argue that the objects are likely superposed on the sky; this is reasonable given the complex area. Without an association, the question of where is the supernova remnant left behind following the birth of PSR J1617-5055 remains open. We also discuss a possible association between PSR J1617-5055 and the gamma-ray source 2CG 333+01. Though an association is energetically plausible, it is unlikely given that EGRET did not detect 2CG 333+01.Comment: 18 pages, 2 encapsulated Postscript figures, uses AAS LaTeX style files. Accepted for publication in The Astrophysical Journal Letter

Identification of the Mass Donor Star's Spectrum in SS 433

We present spectroscopy of the microquasar SS 433 obtained near primary eclipse and disk precessional phase Psi = 0.0, when the accretion disk is expected to be most ``face-on''. The likelihood of observing the spectrum of the mass donor is maximized at this combination of orbital and precessional phases since the donor is in the foreground and above the extended disk believed to be present in the system. The spectra were obtained over four different runs centered on these special phases. The blue spectra show clear evidence of absorption features consistent with a classification of A3-7 I. The behavior of the observed lines indicates an origin in the mass donor. The observed radial velocity variations are in anti-phase to the disk, the absorption lines strengthen at mid-eclipse when the donor star is expected to contribute its maximum percentage of the total flux, and the line widths are consistent with lines created in an A supergiant photosphere. We discuss and cast doubt on the possibility that these lines represent a shell spectrum rather than the mass donor itself. We re-evaluate the mass ratio of the system and derive masses of 10.9 +/- 3.1 Msun and 2.9 +/- 0.7 Msun for the mass donor and compact object plus disk, respectively. We suggest that the compact object is a low mass black hole. In addition, we review the behavior of the observed emission lines from both the disk/wind and high velocity jets.Comment: submitted to ApJ, 24 pages, 7 figure

Whole Earth Telescope observations of the hot helium atmosphere pulsating white dwarf EC 20058-5234

We present the analysis of a total of 177h of high-quality optical time-series photometry of the helium atmosphere pulsating white dwarf (DBV) EC 20058-5234. The bulk of the observations (135h) were obtained during a WET campaign (XCOV15) in July 1997 that featured coordinated observing from 4 southern observatory sites over an 8-day period. The remaining data (42h) were obtained in June 2004 at Mt John Observatory in NZ over a one-week observing period. This work significantly extends the discovery observations of this low-amplitude (few percent) pulsator by increasing the number of detected frequencies from 8 to 18, and employs a simulation procedure to confirm the reality of these frequencies to a high level of significance (1 in 1000). The nature of the observed pulsation spectrum precludes identification of unique pulsation mode properties using any clearly discernable trends. However, we have used a global modelling procedure employing genetic algorithm techniques to identify the n, l values of 8 pulsation modes, and thereby obtain asteroseismic measurements of several model parameters, including the stellar mass (0.55 M_sun) and T_eff (~28200 K). These values are consistent with those derived from published spectral fitting: T_eff ~ 28400 K and log g ~ 7.86. We also present persuasive evidence from apparent rotational mode splitting for two of the modes that indicates this compact object is a relatively rapid rotator with a period of 2h. In direct analogy with the corresponding properties of the hydrogen (DAV) atmosphere pulsators, the stable low-amplitude pulsation behaviour of EC 20058 is entirely consistent with its inferred effective temperature, which indicates it is close to the blue edge of the DBV instability strip. (abridged)Comment: 19 pages, 8 figures, 5 tables, MNRAS accepte

Typical equilibrium state of an embedded quantum system

We consider an arbitrary quantum system coupled non perturbatively to a large arbitrary and fully quantum environment. In [G. Ithier and F. Benaych-Georges, Phys. Rev. A 96, 012108 (2017)] the typicality of the dynamics of such an embedded quantum system was established for several classes of random interactions. In other words, the time evolution of its quantum state does not depend on the microscopic details of the interaction. Focusing at the long time regime, we use this property to calculate analytically a new partition function characterizing the stationary state and involving the overlaps between eigenvectors of a bare and a dressed Hamiltonian. This partition function provides a new thermodynamical ensemble which includes the microcanonical and canonical ensembles as particular cases. We check our predictions with numerical simulations.Comment: 1 figure, 5 pages. This article supersedes the part on the equilibrium state in arXiv:1510.0435