Photoelectric observations of Krzeminski's star, the companion of Cen X-3

Centaurus X-3 was the first discovered X-ray source whose intensity is pulsed and eclipsed. Though the X-ray properties of the Cen X-3 system have been intensively studied, the optical properties remained unstudied until Krzeminski's identification of the optical counterpart of Cen X-3. Observations of the X-ray eclipse duration, pulsation frequency variation, and pulse arrival time variation have been used to place limits on the nature of the system and to predict the nature of the optical companion and X-ray sources. An observational determination is presented of the several system parameters based on a preliminary interpretation of the light curve of Krzeminski's star

Flow detectors having mechanical oscillators, and use thereof in flow characterization systems

An improved system (100), resonator flow detector (102) and method for characterizing a fluid sample that includes o injecting a fluid sample into a mobile phase of a flow characterization system (106), and detecting a property of the fluid sample > or of a component thereof with a flow detector (102) comprising a mechanical resonator (120), preferably one that is operated at a frequency less than about 1 MHz, such as tuning fork resonator

Contextual modulation of primary visual cortex by auditory signals

Early visual cortex receives non-feedforward input from lateral and top-down connections (Muckli & Petro 2013 Curr. Opin. Neurobiol. 23, 195–201. (doi:10.1016/j.conb.2013.01.020)), including long-range projections from auditory areas. Early visual cortex can code for high-level auditory information, with neural patterns representing natural sound stimulation (Vetter et al. 2014 Curr. Biol. 24, 1256–1262. (doi:10.1016/j.cub.2014.04.020)). We discuss a number of questions arising from these findings. What is the adaptive function of bimodal representations in visual cortex? What type of information projects from auditory to visual cortex? What are the anatomical constraints of auditory information in V1, for example, periphery versus fovea, superficial versus deep cortical layers? Is there a putative neural mechanism we can infer from human neuroimaging data and recent theoretical accounts of cortex? We also present data showing we can read out high-level auditory information from the activation patterns of early visual cortex even when visual cortex receives simple visual stimulation, suggesting independent channels for visual and auditory signals in V1. We speculate which cellular mechanisms allow V1 to be contextually modulated by auditory input to facilitate perception, cognition and behaviour. Beyond cortical feedback that facilitates perception, we argue that there is also feedback serving counterfactual processing during imagery, dreaming and mind wandering, which is not relevant for immediate perception but for behaviour and cognition over a longer time frame. This article is part of the themed issue ‘Auditory and visual scene analysis’

Backwards is the way forward: feedback in the cortical hierarchy predicts the expected future

Clark offers a powerful description of the brain as a prediction machine, which offers progress on two distinct levels. First, on an abstract conceptual level, it provides a unifying framework for perception, action, and cognition (including subdivisions such as attention, expectation, and imagination). Second, hierarchical prediction offers progress on a concrete descriptive level for testing and constraining conceptual elements and mechanisms of predictive coding models (estimation of predictions, prediction errors, and internal models)

A spectroscopic study of LMC X-4

The orbital radial velocity semi-amplitude of the binary star system LMC X-4 primary was determined to be 37.9 + or - 2.4 km/s from measurements of the hydrogen absorption lines. The semi-amplitude of the He I and He II absorption lines are consistent with this, namely 44.9 + or - 5.0 and 37.3 + or - 5.3 km/s. The phase and shape of the radial velocity curves of the three ions are consistent with a circular orbit and an ephemeris based upon X-ray measurements of the neutron star, with the exception that the He II absorption line radial velocity curve has detectable shape distortion. Measurements of the He II LAMBOA 4686 emission line velocity are consistent with a phase shifted sine wave of semi-amplitude 535 km/s, a square wave of semi-amplitude 407 km/s, or high order harmonic fits. The spectral type was found to be 08.5 IV-V during X-ray eclipse. Variations to types as early as 07 occur, but not as a function or orbital phase. Absorption line peculiarities were noted on 6 of 58 spectra

Decoding face categories in diagnostic subregions of primary visual cortex

Higher visual areas in the occipitotemporal cortex contain discrete regions for face processing, but it remains unclear if V1 is modulated by top-down influences during face discrimination, and if this is widespread throughout V1 or localized to retinotopic regions processing task-relevant facial features. Employing functional magnetic resonance imaging (fMRI), we mapped the cortical representation of two feature locations that modulate higher visual areas during categorical judgements – the eyes and mouth. Subjects were presented with happy and fearful faces, and we measured the fMRI signal of V1 regions processing the eyes and mouth whilst subjects engaged in gender and expression categorization tasks. In a univariate analysis, we used a region-of-interest-based general linear model approach to reveal changes in activation within these regions as a function of task. We then trained a linear pattern classifier to classify facial expression or gender on the basis of V1 data from ‘eye’ and ‘mouth’ regions, and from the remaining non-diagnostic V1 region. Using multivariate techniques, we show that V1 activity discriminates face categories both in local ‘diagnostic’ and widespread ‘non-diagnostic’ cortical subregions. This indicates that V1 might receive the processed outcome of complex facial feature analysis from other cortical (i.e. fusiform face area, occipital face area) or subcortical areas (amygdala)

An investigation of the energy balance of solar active regions using the ACRIM irradiance data

The correlation between the irradiance (as measured by the Active Cavity Radiometer Irradiance Monitor and the Earth Radiation Budget) as corrected for sunspot flux deficit (which is responsible for most of the variance of the uncorrected signal) and both the 205 nm flux (as measured by Nimbus 7) and a photometric facular index is discussed. The computer program which simulates two-dimensional convection in a compressible, stratified medium is described. Equipment which was acquired to perform high precision, white-light observations of sunspot areas, and procedures were tested. Analysis of observations of large scale convective heat inhomogeneities which were obtained in May 1985 was begun

How Mental Healthcare Professionals Navigate Telehealth: Extensions of Communication Privacy Management and Electronic Propinquity Theories

Remote mental healthcare has become a new normal, yet there is limited research on how mental healthcare professionals create safe, secure virtual environments for patients while in separate physical locations. Computer-mediated communication theories are well-suited for exploring, and even improving, this critical endeavor. We do this by elaborating communication privacy management (CPM) theory to recognize the boundary coordination involved in contemporary videoconferencing, as exemplified in telehealth interactions. Furthermore, we expand the theory of electronic propinquity (TEP) to appreciate the role of medium-related digital skills in shaping online propinquity. Interviews with 20 mental healthcare professionals reveal that boundary coordination in telemental healthcare takes place in both the shared virtual space and separate physical spaces. Moreover, boundaries are more fluid, or elastic, than CPM allows. We also find that participants generally felt very close to their clients over telehealth, although the digital skills of clients sometimes disrupted care. In addition to these theoretical findings, this research yields practical insights into privacy boundary coordination strategies for telehealth for mental healthcare providers

How Mental Healthcare Professionals Navigate Telehealth: Extensions of Communication Privacy Management and Electronic Propinquity Theories

Remote mental healthcare has become a new normal, yet there is limited research on how mental healthcare professionals create safe, secure virtual environments for patients while in separate physical locations. Computer-mediated communication theories are well-suited for exploring, and even improving, this critical endeavor. We do this by elaborating communication privacy management (CPM) theory to recognize the boundary coordination involved in contemporary videoconferencing, as exemplified in telehealth interactions. Furthermore, we expand the theory of electronic propinquity (TEP) to appreciate the role of medium-related digital skills in shaping online propinquity. Interviews with 20 mental healthcare professionals reveal that boundary coordination in telemental healthcare takes place in both the shared virtual space and separate physical spaces. Moreover, boundaries are more fluid, or elastic, than CPM allows. We also find that participants generally felt very close to their clients over telehealth, although the digital skills of clients sometimes disrupted care. In addition to these theoretical findings, this research yields practical insights into privacy boundary coordination strategies for telehealth for mental healthcare providers

Basin and Crater Ejecta Contributions to the South Pole-Aitken Basin (SPA) Regolith; Positive Implications for Robotic Surface Samples

The ability of impacts of all sizes to laterally transport ejected material across the lunar surface is well-documented both in lunar samples [1-4] and in remote sensing data [5-7]. The need to quantify the amount of lateral transport has lead to several models to estimate the scale of this effect. Such models have been used to assess the origin of components at the Apollo sites [8-10] or to predict what might be sampled by robotic landers [11-13]. Here we continue to examine the regolith inside the South Pole-Aitken Basin (SPA) and specifically assess the contribution to the SPA regolith by smaller craters within the basin. Specifically we asses the effects of four larger craters within SPA, Bose, Bhabha, Stoney, and Bellinsgauzen all located within the mafic enhancement in the center of SPA (Figure 1). The region around these craters is of interest as it is a possible landing and sample return site for the proposed Moon-Rise mission [14-17]. Additionally, understanding the provenance of components in the SPA regolith is important for interpreting remotely sensed data of the basin interior [18-20]