Chromatic discrimination measures in mature observers depend on the response window

Our past anecdotal evidence prompted that a longer response window (RW) in the Trivector test (Cambridge Colour Test) improved mature observers’ estimates of chromatic discrimination. Here, we systematically explored whether RW variation affects chromatic discrimination thresholds measured by the length of Protan, Deutan and Tritan vectors. We employed the Trivector test with three RWs: 3 s, 5 s, and 8 s. Data of 30 healthy normal trichromats were stratified as age groups: ‘young’ (20–29 years), ‘middle-aged’ (31–48 years), and ‘mature’ (57–64 years). We found that for the ‘young’ and ‘middle-aged’, the thresholds were comparable at all tested RWs. However, the RW effect was apparent for the ‘mature’ observers: their Protan and Tritan thresholds decreased at 8-s RW compared to 3-s RW; moreover, their Tritan threshold decreased at 5-s RW compared to 3-s RW. Elevated discrimination thresholds at shorter RWs imply that for accurate performance, older observers require longer stimulus exposure and are indicative of ageing effects manifested by an increase in critical processing duration. Acknowledging low numbers in our ‘middle-aged’ and ‘mature’ samples, we consider our study as pilot. Nonetheless, our findings encourage us to advocate a RW extension in the Trivector protocol for testing mature observers, to ensure veridical measures of their chromatic discrimination by disentangling these from other ageing effects—slowing down of both motor responses and visual processing

Salmonella isolated from crocodiles and other reptiles during the period 1985-1994 in South Africa

Over a 10-year period, 173 isolates of Salmonella were obtained during routine isolation from reptiles. Of the 173 isolates, 92 different Salmonella serovars were identified. Of them, 61 (66%) belonged to subspecies I, nine to subspecies II and 21 to subspecies Ill (lIla and lllb), and one to subspecies IV. The majority of isolates were from farmed Nile crocodiles (145), three from wild-caught African dwarf crocodiles, 11 from captive snakes, 13 from lizards and one from a tortoise. The isolates from the tortoise and lizards were subspecies I isolates (Zaire and Tsevie, respectively). Of the snakes, nine isolates were S.lll. The serovars isolated most often from the crocodiles were of subspecies I (32 serovars). Eight were from subspecies II, seven from subspecies Ill and one from subspecies IV. The most frequently identified serovars were Typhimurium (seven), Tsevie (six), Duval (six), Schwerin (six), Tinda (six), and Tallahassee (six). On two commercial crocodile breeding farms that had experienced ongoing problems for about two years, many isolates of Salmonella were made. Some of these serovars were isolated more than once, and also months apart. No single Salmonella serovar predominated, nor did a single pathological condition. These salmonellas were predominantly of subspecies I.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Reintegrating informal settlements into the Greater Cairo Region of Egypt through the regional highway network

This study analyses informal settlements and the regional highway network in the Greater Cairo Region of Egypt to propose alternatives to reduce regional spatial fragmentation that may lead to spatial segregation. Findings indicate that the street structure of informal settlements provides a configuration that supports social interaction for their residents. While the regional highway network can act to physically disconnect the wider region by isolating or splitting neighbourhoods, some highways can act as an integrator. Analysis at the urban scale can identify points in the settlements’ street networks where they can be connected to the regional transport network, which could have an impact on regional consolidation

The use of a single complement fixation test technique in bovine brucellosis, Johne's disease, dourine, equine piroplasmosis and Q fever serology

The same techniques may be used in the complement fixation test (CFT) for the serological diagnosis of bovine brucellosis, Johne's disease (paratuberculosis), dourine, equine piroplasmosis and Q fever (caused by Coxiella burnetii). The reproducibility of results is excellent, falling for the most part within the twofold range and never exceeding the fourfold range. Agreement with other laboratories is excellent (i.e. within twofold) in the case of brucellosis and equine piroplasmosis antibody titres. A good correlation between the occurrence of the disease and serological reactions is found on circumstantial evidence in the cases of dourine, Johne's disease and Q fever. A standard unitage system is used to report the antibody titres found in all the tests. To simplify laboratory protocols, laboratories required to employ the CFT for the diagnosis of these diseases are advised to use a single proven technique in all the tests. Problems experienced with transient false-positive Johne's disease antibody titres in cattle following on tuberculin (bovine and avian) testing make it advisable to take specimens for the Johne's disease test prior to performing the tuberculin tests.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Elevated vitreous body glial fibrillary acidic protein in retinal diseases

Purpose: Increased expression of glial fibrillary acidic protein (GFAP) is a characteristic of gliotic activation (Müller cells and astrocytes) in the retina. This study assessed vitreous body GFAP levels in various forms of retinal pathology. Methods: This prospective study included 82 patients who underwent vitrectomy (46 retinal detachments (RDs), 13 macular hole (MHs), 15 epiretinal glioses (EGs), 8 organ donors). An established enzyme–linked immunosorbent assay (ELISA, SMI26) was used for quantification of GFAP. Results: The highest concentration of vitreous body GFAP in organ donors was 20 pg/mL and it was used as the cutoff. A significant proportion of patients suffering from RD (65 %) to EG (53 %) had vitreous body GFAP levels above this cutoff when compared to organ donors (0 %, p < 0.0001, p = 0.0194, respectively, Fisher’s exact test) and MH (8 %, p < 0.0001, p = 0.0157, respectively). In RD and EG, vitreous body GFAP levels were correlated with axial length (R = 0.69, R = 0.52, p < 0.05 for both). Conclusions: The data suggest that human vitreous body GFAP is a protein biomarker for glial activation in response to retinal pathologies. Vitreous body GFAP levels may be of interest as a surrogate outcome for experimental treatment strategies in translational studies

Technique for the collection of clear urine from the Nile crocodile (Crocodylus niloticus)

Urine samples can be a very useful diagnostic tool for the evaluation of animal health. In this article, a simple technique to collect urine from the Nile crocodile (Crocodylus niloticus) was described, based on a similar unpublished technique developed for the American alligator (Alligator mississippiensis) using a canine urinary catheter. With this technique, it was possible to collect relatively clean urine samples from Nile crocodiles of different sizes using canine urinary catheters or small diameter stomach tubes. Based on the gross anatomical features of the cloaca of the Nile crocodile, it was confirmed that urine accumulates in a chamber consisting of the urodeum and coprodeum. Faecal material is stored temporarily in the very short rectum, which is separated from the urinary chamber by the rectocoprodeal sphincter.The Norwegian Council for Higher Education’s Program for Development, Research and Educationhttp://www.jsava.co.zamn201

Remembering Marikana: Public art intervention and the right to the city in Cape Town

This article investigates the role played by cultural initiatives in urban struggles in South Africa, and the emergence of public art to assert the right to the city. I explore how artistic– activist interventions engage an understanding of social justice and the right to the city in provocative visual and performance art. I demonstrate how such interventions reflect Lefebvre’s conceptualisation of the city as a space to be inhabited in an active process, which critically includes its re-imagination. The paper focuses on creative interventions in Cape Town that confronted the city’s genteel public space with the second and third anniversary of the shooting of 34 striking miners at Marikana on August 16 2012. I argue that bringing the commemoration of the massacre into the public urban space – where post-apartheid Cape Town exhibits its claim to cosmopolitanism – challenges the politics of space in South Africa. I asked, how these cultural initiatives articulate claims through reimagining the city how they engage with the intertwined politics of culture and class followed by both the city and the nation–state, and how the artistic practices contest urban citizenship in contemporary South Africa