John Septimus Roe and the art of navigation, c. 1815-1830

In this paper, we consider the ways in which practices of drawing and surveying shaped the geographical imagination of British mariners in the tropics. The art of navigation involved a variety of skills, notably sketching and mapping. The history of naval survey and hydrography is often written from the centre, a more‐or‐less halting narrative of science, government and empire in which prominent naval officials hold the stage. Here, we start with a different view ‐ that of the surveyor in the field, or rather on board ship, working with his eyes and his hands to make a record of the voyage. The two views are not mutually exclusive: but the perspectives they give differ in important respects. Our focus in this paper is on a single figure ‐ John Septimus Roe, who later rose to prominence as Surveyor‐General of Western Australia. We are interested here in Roe's more humble early career, as midshipman and master's mate on a number of vessels during and after the Napoleonic Wars, which took him to various sites across the British empire, formal and informal: to the European theatre of war, to North and South America, the Gulf, India, Mauritius, Burma, South‐East Asia and tropical Australia. The images of Rio de Janeiro examined here form part of a corpus which raises much wider questions about the visual culture of navigation and the experience of observation in the early nineteenth century

Linking pain and the body: neural correlates of visually induced analgesia

The visual context of seeing the body can reduce the experience of acute pain, producing a multisensory analgesia. Here we investigated the neural correlates of this “visually induced analgesia” using fMRI. We induced acute pain with an infrared laser while human participants looked either at their stimulated right hand or at another object. Behavioral results confirmed the expected analgesic effect of seeing the body, while fMRI results revealed an associated reduction of laser-induced activity in ipsilateral primary somatosensory cortex (SI) and contralateral operculoinsular cortex during the visual context of seeing the body. We further identified two known cortical networks activated by sensory stimulation: (1) a set of brain areas consistently activated by painful stimuli (the so-called “pain matrix”), and (2) an extensive set of posterior brain areas activated by the visual perception of the body (“visual body network”). Connectivity analyses via psychophysiological interactions revealed that the visual context of seeing the body increased effective connectivity (i.e., functional coupling) between posterior parietal nodes of the visual body network and the purported pain matrix. Increased connectivity with these posterior parietal nodes was seen for several pain-related regions, including somatosensory area SII, anterior and posterior insula, and anterior cingulate cortex. These findings suggest that visually induced analgesia does not involve an overall reduction of the cortical response elicited by laser stimulation, but is consequent to the interplay between the brain's pain network and a posterior network for body perception, resulting in modulation of the experience of pain

The cutaneous 'rabbit' illusion affects human primary sensory cortex somatopically

We used functional magnetic resonance imaging (fMRI) to study neural correlates of a robust somatosensory illusion that can dissociate tactile perception from physical stimulation. Repeated rapid stimulation at the wrist, then near the elbow, can create the illusion of touches at intervening locations along the arm, as if a rabbit hopped along it. We examined brain activity in humans using fMRI, with improved spatial resolution, during this version of the classic cutaneous rabbit illusion. As compared with control stimulation at the same skin sites (but in a different order that did not induce the illusion), illusory sequences activated contralateral primary somatosensory cortex, at a somatotopic location corresponding to the filled-in illusory perception on the forearm. Moreover, the amplitude of this somatosensory activation was comparable to that for veridical stimulation including the intervening position on the arm. The illusion additionally activated areas of premotor and prefrontal cortex. These results provide direct evidence that illusory somatosensory percepts can affect primary somatosensory cortex in a manner that corresponds somatotopically to the illusory percept

The Millennium Galaxy Catalogue: Star counts and the Structure of the Galactic Stellar Halo

We derive a star catalogue generated from the images taken as part of the 37.5 sq. deg Millennium Galaxy Catalogue. These data, alone and together with colours gained from the Sloan Digital Sky Survey Early Data Release, allow the analysis of faint star counts (B(MGC) < 20) at high Galactic latitude (41 < b < 63), as a function of Galactic longitude (239 < l < 353). We focus here on the inner stellar halo, providing robust limits on the amplitude of substructure and on the large-scale flattening. In line with previous results, the thick disk, an old, intermediate-metallicity population, is clearly seen in the colour-magnitude diagram. We find that the Galactic stellar halo within ~10 kpc (the bulk of the stellar mass) is significantly flattened, with an axial ratio of (c/a) =0.56 +/- 0.01, again consistent with previous results. Our analysis using counts-in-cells, angular correlation functions and the Lee 2D statistic, confirms tidal debris from the Sagittarius dwarf but finds little evidence for other substructure in the inner halo, at heliocentric distances of < 5 kpc. This new quantification of the smoothness in coordinate space limits the contribution of recent accretion/disruption to the build-up of the bulk of the stellar halo.Comment: Accepted for publication in MNRAS (figs 16 and 17 degraded here

Remarks on the Zeros of the Associated Legendre Functions with Integral Degree

We present some formulas for the computation of the zeros of the integral-degree associated Legendre functions with respect to the order.Comment: 7 pages, 2 figure

Cannabis use and anxiety: is stress the missing piece of the puzzle?

OBJECTIVE Comorbidity between anxiety and cannabis use is common yet the nature of the association between these conditions is not clear. Four theories were assessed, and a fifth hypothesis tested to determine if the misattribution of stress symptomology plays a role in the association between state-anxiety and cannabis. METHODS Three-hundred-sixteen participants ranging in age from 18 to 71 years completed a short online questionnaire asking about their history of cannabis use and symptoms of stress and anxiety. RESULTS Past and current cannabis users reported higher incidence of lifetime anxiety than participants who had never used cannabis; however, these groups did not differ in state-anxiety, stress, or age of onset of anxiety. State-anxiety and stress were not associated with frequency of cannabis use, but reported use to self-medicate for anxiety was positively associated with all three. Path analyses indicated two different associations between anxiety and cannabis use, pre-existing and high state-anxiety was associated with (i) higher average levels of intoxication and, in turn, acute anxiety responses to cannabis use; (ii) frequency of cannabis use via the mediating effects of stress and self-medication. CONCLUSION None of the theories was fully supported by the findings. However, as cannabis users reporting self-medication for anxiety were found to be self-medicating stress symptomology, there was some support for the stress-misattribution hypothesis. With reported self-medication for anxiety being the strongest predictor of frequency of use, it is suggested that researchers, clinicians, and cannabis users pay greater attention to the overlap between stress and anxiety symptomology and the possible misinterpretation of these related but distinct conditions

Dimension-independent Harnack inequalities for subordinated semigroups

Dimension-independent Harnack inequalities are derived for a class of subordinate semigroups. In particular, for a diffusion satisfying the Bakry-Emery curvature condition, the subordinate semigroup with power $\alpha$ satisfies a dimension-free Harnack inequality provided $\alpha \in(1/2, 1)$, and it satisfies the log-Harnack inequality for all $\alpha \in (0,1).$ Some infinite-dimensional examples are also presented

‘The show must go on!’ Fieldwork, mental health and wellbeing in Geography, Earth and Environmental Sciences

Fieldwork is central to the identity, culture and history of academic Geography, Earth and Environmental Sciences (GEES). However, in this paper we recognise that, for many academic staff, fieldtrips can be a profoundly challenging “ordeal,” ill‐conducive to wellness or effective pedagogic practice. Drawing on research with 39 UK university‐based GEES academics who self‐identify as having a mental health condition, we explore how mental health intersects with spaces and expectations of fieldwork in Higher Education. We particularly focus on their accounts of undertaking undergraduate residential fieldtrips and give voice to these largely undisclosed experiences. Their narratives run counter to normative, romanticised celebrations of fieldwork within GEES disciplines. We particularly highlight recurrent experiences of avoiding fieldwork, fieldwork‐as‐ ordeal, and “coping” with fieldwork, and suggest that commonplace anxieties within the neoliberal academy – about performance, productivity, fitness‐to‐work, self‐presentation, scrutiny and fear‐of‐falling‐behind – are felt particularly intensely during fieldwork. In spite of considerable work to make fieldwork more accessible to students, we find that field‐based teaching is experienced as a focal site of distress, anxiety and ordeal for many GEES academics with common mental health conditions. We conclude with prompts for reflection about how fieldwork could be otherwise