Belfast Without Sight: Exploring Geographies of Blindness

In this paper (he transformed spaces of visually impaired and blind people is explored through a detailed analysis of interview transcripts with twenty seven visually impaired people living in or around Belfast. Data were collected using a structured open-ended interview and were analysed within NUD-IST, a qualitative data analysis package. Analysis revealed that visually impaired people become spatially confused (e.g. lost or disorientated) for two primary reasons. "Self-produced" confusion is spatial confusion caused by the misperception/miscognition of a route (e.g. miscounting intersections). "Situational" confusion is spatial confusion caused by a permanent or temporary localised occurrences such as road works, vehicles parked on pavements, and street furniture. Both types of spatial confusion were found to induce feelings of fear and anxiety, leading to a loss of selfconfidence, embarrassment and frustration, which in turn led to less independent travel and exploration, and constrained patterns of spatial behaviour. Respondents detailed a number of strategies for coping with spatial confusion. In addition, they assessed methods to make Belfast more navigable including environmental modifications and orientation and mobility aid

Pollen dimorphism and dioecy in Vitis aestivalis

Problems of low production and sterile pollen in varieties of Vitis vinifera may be tracable to their ancestral relations with dioecious wild grapes.Like V. riparia, the wild summer grape V. aestivalis has dimorphic male and female flowers; but unlike V. riparia it also has dimorphic pollen grains with the pollen from the female flower being significantly smaller.It seems fairly certain that V. aestivalis is truly dioecious

The Effect of Spatial Tasks on Visually Impaired Peoples' Wayfinding Abilities

Thirty-eight people with visual impairments learned a 483-meter novel route through a university campus in four groups: verbalization, modeling, pointing, and control. The performance of all four groups improved with greater experience of the route, but the modeling group improved more than did the control group

Space Telescope Imaging Spectrograph slitless observations of Small Magellanic Cloud Planetary Nebulae: a study on morphology, emission line intensity, and evolution

A sample of 27 Planetary Nebulae (PNs) in the Small Magellanic Clouds (SMC) have been observed with the Hubble Space Telescope Imaging Spectrograph (HST/STIS) to determine their morphology, size, and the spatial variation of the ratios of bright emission lines. The morphologies of SMC PNs are similar to those of LMC and Galactic PNs. However, only a third of the resolved SMC PNs are asymmetric, compared to half in the LMC. The low metallicity environment of the SMC seems to discourage the onset of bipolarity in PNs. We measured the line intensity, average surface brightness (SB), and photometric radius of each nebula in halpha, hbeta, [O III] lambda4959 and 5007, [NII] 6548 and 6584, [S II] lambda6716 and 5731, He I 6678, and [OI] 6300 and 6363. We show that the surface brightness to radius relationship is the same as in LMC PNs, indicating its possible use as a distance scale indicator for Galactic PNs. We determine the electron densities and the ionized masses of the nebulae where the [S II] lines were measured accurately, and we find that the SMC PNs are denser than the LMC PNs by a factor of 1.5. The average ionized mass of the SMC PNs is 0.3 Msun. We also found that the median [O III]/hbeta intensity ratio in the SMC is about half than the corresponding LMC median. We use Cloudy to model the dependence of the [O III]/hbeta ratio on the oxygen abundance. Our models encompass very well the average observed physical quantities. We suggest that the SMC PNs are principally cooled by the carbon lines, making it hard to study their excitation based on the optical lines at our disposal.Comment: Accepted for publication in the Astrophysical Journal, 30 pages, 13 figures, 6 tables. For high resolution version of Figs 1 to 6, see http://archive.stsci.edu/hst/mcpn/home.htm

The Gemini Deep Deep Survey: II. Metals in Star-Forming Galaxies at Redshift 1.3<z<2

The goal of the Gemini Deep Deep Survey (GDDS) is to study an unbiased sample of K<20.6 galaxies in the redshift range 0.8<z<2.0. Here we determine the statistical properties of the heavy element enrichment in the interstellar medium (ISM) of a subsample of 13 galaxies with 1.34<z<1.97 and UV absolute magnitude M_2000 < -19.65. The sample contains 38% of the total number of identified galaxies in the first two fields of the survey with z>1.3. The selected objects have colors typical of irregular and Sbc galaxies. Strong [OII] emission indicates high star formation activity in the HII regions (SFR~13-106 M_sun/yr). The high S/N composite spectrum shows strong ISM MgII and FeII absorption, together with weak MnII and MgI lines. The FeII column density, derived using the curve of growth analysis, is logN_FeII = 15.54^{+0.23}_{-0.13}. This is considerably larger than typical values found in damped Ly-alpha systems (DLAs) along QSO sight lines, where only 10 out of 87 (~11%) have logN_FeII > 15.2. High FeII column densities are observed in the z=2.72 Lyman break galaxy cB58 (logN_FeII ~ 15.25) and in gamma-ray burst host galaxies (logN_FeII ~ 14.8-15.9). Given our measured FeII column density and assuming a moderate iron dust depletion (delta_Fe ~ 1 dex), we derive an optical dust extinction A_V ~ 0.6. If the HI column density is log N(HI)<21.7 (as in 98% of DLAs), then the mean metallicity is Z/Z_sun > 0.2. The high completeness of the GDDS sample implies that these results are typical of star-forming galaxies in the 1<z<2 redshift range, an epoch which has heretofore been particularly challenging for observational programs.Comment: ApJ in press, corrected HI column density estimat

Complex Mg II absorption in the outer disk of M61

The increasing availability of high quality spectra of QSO absorption line systems at resolutions of only a few km/s is expected to facilitate the translation of the kinematics of components comprising the lines into the spatial distribution of gas around an absorbing galaxy. In this Letter, we present Hubble Space Telescope (HST) spectra of Q1219+047, a QSO whose sightline passes 21 h-1 kpc from the center of M61, through the outer regions of an extended H I disk. We detect complex Mg II absorption, spanning a velocity range of approximately 300 km/s, and strong C IV absorption; these are the first UV observations of a QSO absorption line system arising in the outskirts of a disk of a nearby galaxy at low inclination. Our observations are at odds with models of galaxies in which absorbing clouds co-rotate with a galaxy's disk, because M61's low inclination should give rise to only a few Mg II components spread over a small velocity range in such a model. Hence our results throw doubt on whether absorption line profiles can be used to infer the spatial distribution of gas around absorbing galaxies.Comment: Accepted by Astrophysical Journal Letters. AASTeX style, includes two Postscript figures. Paper can also be obtained from http://www.roe.ac.uk/#researc