title: Dependence of the IBEX Ribbon Geometry on Pitch-Angle Scattering outside the Heliopause

authors: Zirnstein, E. J.

subjects: Science & Technology

abstract: Interstellar Boundary Explorer (IBEX) observations of the “ribbon” of enhanced energetic neutral atom (ENA) fluxes show that it is a persistent feature that approximately forms a circle in the sky, likely formed from secondary ENAs whose source lies outside the heliopause. The IBEX ribbonʼsgeometry(radius and center) depends on ENA energy and is believed to be influenced by the draping of the ISMF and the latitudinal structure of the SW. In this study, we demonstrate that the ribbonʼs geometry also depends on the pitch-angle scattering rate of ions outside the heliopause, which we simulate under strong and weak-scattering limits. The ribbon radius in the weak-scattering model is ∼4° larger than IBEX observations at most energies, and the strong-scattering model produces radii statistically consistent with IBEX at 1.1–2.7 keV. The simulated ribbon center is shifted between ∼2° and 5° along the B–V plane away from the IBEX center for the weak and strong limits, respectively, suggesting that the pristine ISMF far from the heliosphere is shifted ∼2°–5° away from our simulated ISMF toward the VLISM inflow direction. However, the magnitude needs to be decreased from ∼3to2μG for the weak-scattering model to be consistent with the IBEX ribbon radius, which seems unlikely. We also f ind that the presence of interstellar He does not significantly affect the ribbon in the strong-scattering limit but yields weaker agreement with data in the weak limit. Our results slightly favor the strong-scattering limit for the ribbonʼs origin.

text: Dependence of the IBEX Ribbon Geometry on Pitch-Angle Scattering outside the Heliopause Interstellar Boundary Explorer (IBEX) observations of the “ribbon” of enhanced energetic neutral atom (ENA) fluxes show that it is a persistent feature that approximately forms a circle in the sky, likely formed from secondary ENAs whose source lies outside the heliopause. The IBEX ribbonʼsgeometry(radius and center) depends on ENA energy and is believed to be influenced by the draping of the ISMF and the latitudinal structure of the SW. In this study, we demonstrate that the ribbonʼs geometry also depends on the pitch-angle scattering rate of ions outside the heliopause, which we simulate under strong and weak-scattering limits. The ribbon radius in the weak-scattering model is ∼4° larger than IBEX observations at most energies, and the strong-scattering model produces radii statistically consistent with IBEX at 1.1–2.7 keV. The simulated ribbon center is shifted between ∼2° and 5° along the B–V plane away from the IBEX center for the weak and strong limits, respectively, suggesting that the pristine ISMF far from the heliosphere is shifted ∼2°–5° away from our simulated ISMF toward the VLISM inflow direction. However, the magnitude needs to be decreased from ∼3to2μG for the weak-scattering model to be consistent with the IBEX ribbon radius, which seems unlikely. We also f ind that the presence of interstellar He does not significantly affect the ribbon in the strong-scattering limit but yields weaker agreement with data in the weak limit. Our results slightly favor the strong-scattering limit for the ribbonʼs origin.

year: 2021-02-01

title: Selective attention in dairy cattle

authors: Blackmore, Tania Louise

subjects: Social Sciences

abstract: In a replication of Reynolds (1961), two cows learned to discriminate between compound stimuli in a forced choice procedure where pushing through a one-way gate marked with a red cross (S+) gave access to food. Pushing through a one-way gate marked with a yellow triangle (S−) gave no access to food. To investigate whether shape or colour was controlling behaviour, probe tests varied either the shape or the colour of the stimuli (e.g., a red vs. a yellow cross, and a red cross vs. a red triangle). Results suggested control by colour rather than shape, as the gate marked with the red stimulus was chosen more than the gate marked with the yellow stimulus regardless of stimulus shape, and when two shapes of the same colour (either red or yellow) were presented, cows chose both equally. Further probe tests with painted red, white, and yellow stimuli showed that the cows had learned to avoid yellow rather than to approach red, suggesting discriminative behaviour was controlled by the colour of the negative stimulus and not by either aspect of the positive stimulus. It is not clear why the negative stimulus was more salient, but it may reflect a tendency for cows to learn to avoid farm handling practices which involve mainly negative stimuli.

text: Selective attention in dairy cattle In a replication of Reynolds (1961), two cows learned to discriminate between compound stimuli in a forced choice procedure where pushing through a one-way gate marked with a red cross (S+) gave access to food. Pushing through a one-way gate marked with a yellow triangle (S−) gave no access to food. To investigate whether shape or colour was controlling behaviour, probe tests varied either the shape or the colour of the stimuli (e.g., a red vs. a yellow cross, and a red cross vs. a red triangle). Results suggested control by colour rather than shape, as the gate marked with the red stimulus was chosen more than the gate marked with the yellow stimulus regardless of stimulus shape, and when two shapes of the same colour (either red or yellow) were presented, cows chose both equally. Further probe tests with painted red, white, and yellow stimuli showed that the cows had learned to avoid yellow rather than to approach red, suggesting discriminative behaviour was controlled by the colour of the negative stimulus and not by either aspect of the positive stimulus. It is not clear why the negative stimulus was more salient, but it may reflect a tendency for cows to learn to avoid farm handling practices which involve mainly negative stimuli.

year: 2016

title: A proposed hauora Māori clinical guide for psychologists: Using the hui process and meihana model in clinical assessment and formulation

authors: Pitama, Suzanne G.

subjects: Māori

abstract: This paper documents a joint initiative of clinical practice educators from four tertiary institutions and their engagement in the design and development of a proposed Hauora Māori Clinical Guide for Psychologists, which outlines how to apply the Hui Process and Meihana Model to applied psychology. It describes the ability for this proposed Hauora Maori Clinical Guide for Psychologists to assist clinicians, professional psychology training programmes and institutions in meeting the expectations of the Health Practitioners Act and The New Zealand Psychologists Board’s (NZPB) Standards and Procedures document. It presents how this proposed guide can support the implementation of clinical and cultural competence and the Code of Ethics for Psychologists Working in New Zealand. It also provides an opportunity for the psychology profession to demonstrate responsivity to Te Tiriti o Waitangi obligations.

text: A proposed hauora Māori clinical guide for psychologists: Using the hui process and meihana model in clinical assessment and formulation This paper documents a joint initiative of clinical practice educators from four tertiary institutions and their engagement in the design and development of a proposed Hauora Māori Clinical Guide for Psychologists, which outlines how to apply the Hui Process and Meihana Model to applied psychology. It describes the ability for this proposed Hauora Maori Clinical Guide for Psychologists to assist clinicians, professional psychology training programmes and institutions in meeting the expectations of the Health Practitioners Act and The New Zealand Psychologists Board’s (NZPB) Standards and Procedures document. It presents how this proposed guide can support the implementation of clinical and cultural competence and the Code of Ethics for Psychologists Working in New Zealand. It also provides an opportunity for the psychology profession to demonstrate responsivity to Te Tiriti o Waitangi obligations.

year: 2017