Karma and other stories & essays,

"Editor's note" signed: Albert Mordell.

Book of monsters,

Name and address on front pastedown.

Wolbachia pipientis in Australian spiders

Wolbachia pipientis is an endosymbiotic bacterium common to arthropods and filarial nematodes. This study presents the first survey and characterization of Wolbachia pipientis that infect spiders. All spiders were collected from Queensland, Australia during 2002-2003 and screened for Wolbachia infection using PCR approaches. The Wolbachia strains present in the spiders are diverse, paraphyletic, and for the most part closely related to strains that infect insects. We have also identified several spider Wolbachia strains that form a lineage outside the currently recognized six main Wolbachia supergroups (A-F). Incongruence between spider and Wolbachia phylogenies indicates a history of horizontal transmission of the bacterium in these host taxa. Like other arthropods, spiders are capable of harboring multiple Wolbachia strains.

Attentional bias toward fear-related stimuli: An investigation with nonselected children and adults and children with anxiety disorders

Research investigating anxiety-related attentional bias for emotional information in anxious and nonanxious children has been equivocal with regard to whether a bias for fear-related stimuli is unique to anxious children or is common to children in general. Moreover, recent cognitive theories have proposed that an attentional bias for objectively threatening stimuli may be common to all individuals, with this effect enhanced in anxious individuals. The current study investigated whether an attentional bias toward fear-related pictures could be found in nonselected children (n = 105) and adults (n = 47) and whether a sample of clinically anxious children (n = 23) displayed an attentional bias for fear-related pictures over and above that expected for nonselected children. Participants completed a dot-probe task that employed fear-related, neutral, and pleasant pictures. As expected, both adults and children showed a stronger attentional bias toward fear-related pictures than toward pleasant pictures. Consistent with some findings in the childhood domain, the extent of the attentional bias toward fear-related pictures did not differ significantly between anxious children and nonselected children. However, compared with nonselected children, anxious children showed a stronger attentional bias overall toward affective picture stimuli. (C) 2004 Elsevier Inc. All rights reserved.

Snakes and cats in the flower bed: Fast detection is not specific to pictures of fear-relevant animals

The observation that snakes and spiders are found faster among flowers and mushrooms than vice versa and that this search advantage is independent of set size supports the notion that fear-relevant stimuli are processed preferentially in a dedicated fear module. Experiment I replicated the faster identification of snakes and spiders but also found a set size effect in a blocked, but not in a mixed-trial, sequence. Experiment 2 failed to find faster identification of snake and spider deviants relative to other animals among flowers and mushrooms and provided evidence for a search advantage for pictures of animals, irrespective of their fear relevance. These findings suggest that results from the present visual search task cannot support the notion of preferential processing of fear relevance.

Idiopathic necrotizing dermatitis: Current management

Objectives: To identify and demonstrate necrotizing dermatitis in infancy; an uncommon, puzzling syndrome, in which anecdotal reporting and personal experience indicates that one third of cases may require skin grafting. Much informed discussion about the pathogenesis of this distressing syndrome centres on the role of spider envenomation; and in particular on the speculative role of the Australian White-tailed spider, Lampona cylindrata. Methods: We present here six cases of necrotizing dermatitis treated surgically at the Royal Children's Hospital and Mater Children's Hospital in Brisbane over the period from 1991 to 1999. Clinical history, surgical details and pathological investigations were reviewed in each case. Microbiological investigation of necrotic ulcers included standard aerobic and anaerobic culture. Result: Nocardia and Staphylococcus were cultured in two cases, but no positive bites were witnessed and no spiders were identified by either the children or their parents. All cases were treated with silver sulphadiazine creme. Two of the infants required general anaesthesia, excision debridement and split skin grafting. The White-tailed spider, Lampona cylindrata, does not occur in Queensland, but Lampona murina does; neither species has necrotizing components in its venom. Circumstantial evidence is consistent with this syndrome being due to invertebrate envenomation, possibly following arachnid bites. Conclusion: In our experience there is insufficient evidence to impute a specific genus as the cause, at this stage of scientific knowledge. If the offending creature is a spider, we calculate that the syndrome of necrotizing dermatitis occurs in less than 1 in 5000 spider bites.

Attentional bias to pictures of fear-relevant animals in a dot probe task

Attentional bias to fear-relevant animals was assessed in 69 participants not preselected on self-reported anxiety with the use of a dot probe task showing pictures of snakes, spiders, mushrooms, and flowers. Probes that replaced the fear-relevant stimuli (snakes and spiders) were found faster than probes that replaced the non-fear-relevant stimuli, indicating an attentional bias in the entire sample. The bias was not correlated with self-reported state or trait anxiety or with general fearfulness. Participants reporting higher levels of spider fear showed an enhanced bias to spiders, but the bias remained significant in low scorers. The bias to snake pictures was not related to snake fear and was significant in high and low scorers. These results indicate preferential processing of fear-relevant stimuli in an unselected sample.

The medical zoologist - Ronald Vernon Southcott

Dr Ronald Vernon Southcott (1918–1998) was amongst the greatest of the Australian doctor-naturalists. His toxinological contributions included the description and naming of the box-jellyfish, Chironex fleckeri, the first definitive study (1950–1957) of the toxinology, taxonomy and biology of Australian scorpions; and the first observations in Australia of the introduced fiddleback spider, Loxosceles. His research into the medical effects of toxic fungi, poisonous plants and Australian insects was extensive. He was a founding member of the International Society on Toxinology and served on the Toxicon Editorial Board for more than 30 years. He also made extensive contributions to acarology, and to the taxonomy of mites, specifically the sub-families and genera of the Erythraeoidea. This prodigious output was achieved by one who, with the exception of war service (1942–1946), almost never travelled outside South Australia, was almost entirely self-funded and worked from his home laboratory. With Dr. P.D. Scott and C.J. Glover, he was also the authority on the fish of South Australia. Dr. Southcott was also a medical epidemiologist and senior medical administrator (1949–1978) with the Australian Commonwealth Department of Veterans’ Affairs. He served for 30 years as an Honorary Consultant in Toxicology to the Adelaide Children's Hospital. As a zoologist and botanist of astounding breadth, he worked indefatigably in a voluntary capacity for the South Australian Museum, of which he was Museum Board Chairman from 1974 to 1982. In the pantheon of the great doctor-naturalists who have worked in Australia, he stands with Robert Brown and Thomas Lane Bancroft.

Of snakes and flowers: Does preferential detection of pictures of fear-relevant animals in visual search reflect on fear-relevance?

Previous research in visual search indicates that animal fear-relevant deviants, snakes/spiders, are found faster among non fear-relevant backgrounds, flowers/mushrooms, than vice versa. Moreover, deviant absence was indicated faster among snakes/spiders and detection time for flower/mushroom deviants, but not for snake/spider deviants, increased in larger arrays. The current research indicates that the latter 2 results do not reflect on fear-relevance, but are found only with flower/mushroom controls. These findings may reflect on factors such as background homogeneity, deviant homogeneity, or background-deviant similarity. The current research removes contradictions between previous studies that used animal and social fear-relevant stimuli and indicates that apparent search advantages for fear-relevant deviants seem likely to reflect on delayed attentional disengagement from fear-relevance on control trials.

Choroidal osteoma: evidence of progression and decalcification over 20 years

Choroidal osteoma is a rare, benign, ossifying tumour of the choroid of unknown aetiology. In contrast to other types of intraocular ossification, choroidal osteoma is found typically in young healthy females in the second or third decades of life with no history of systemic or ocular disease. Choroidal osteoma is a deep, pale yellow lesion with distinct geographic borders at the juxtapapillary or macular region, with branching 'spider' vessels on the surface of the tumour. These features should help differentiate choroidal osteoma from other types of intraocular tumour and the diagnosis can be confirmed with ultrasonography and computerised tomography. Here we report an initially unilateral case of choroidal osteoma, which decalcified over 20 years but during the same period the fellow eye also developed a choroidal osteoma to become a bilateral case. Despite the benign nature of the tumour, vision may be compromised by gradual atrophy of the overlying retina, serous retinal detachment, accumulation of sub-retinal fluid and sub-retinal haemorrhage associated with choroidal neovascularisation. Frequent examinations are recommended for patients with choroidal osteoma, for early detection of a subretinal neovascular membrane and potential treatment with laser photocoagulation.

Binding of small molecules to DNA junctions

Previous results in our laboratory suggest that the (CG) 4 segments whether present in a right-handed or a left-handed conformation form distinctive junctions with adjacent random sequences. These junctions and their associated sequences have unique structural and thermodynamic properties that may be recognized by DNA-binding molecules. This study probes these sequences by using the following small ligands: actinomycin D, 1,4-bis(((di(aminoethyl)amino)ethyl)amino)anthracene-9,10-dione, ametantrone, and tris(phenanthroline)ruthenium (II). These ligands may recognize the distinctive features associated to the (CG)4 segment and its junctions and thus interact preferentially near these sequences. Restriction enzyme inhibition assays were used to determine whether or not binding interactions took place, and to approximate locations of these interactions. These binding studies are first carried out using two small synthetic oligomers BZ-III and BZ-IV. The (5meCG)4 segment present in BZ-III adopts the Z-conformation in the presence of 50 m M Co(NH3)63+. In BZ-IV, the unmethylated (CG)4 segment changes to a non-B conformation in the presence of 50 m M Co(NH3)63+. BZ-IV, containing the (CG)4 segment, was inserted into a clone plasmid then digested with the restriction enzyme Hinf I to produce a larger fragment that contains the (CG)4 segment. The results obtained on the small oligomers and on the larger fragment for restriction enzyme Mbo I indicate that 1,4-bis(((di(aminoethyl)amino)ethyl)amino)anthracene-9,10-dione binds more efficiently at or near the (CG)4 segment. Restriction enzymes EcoRV, Sac I and Not I with cleavage sites upstream and downstream of the (CG)4 insert were used to further localize binding interactions in the vicinity of the (CG)4 insert. RNA polymerase activity was studied in a plasmid which contained the (CG)4 insert downstream from the promoter sites of SP6 and T7 RNA polymerases. Activities of these two polymerases were studied in the presence of each one of the ligands used throughout the study. Only actinomycin D and spider, which bind at or near the (CG)4 segment, alter the activities of SP6 and T7 RNA polymerases. Surprisingly, enhancement of polymerase activity was observed in the presence of very low concentrations of actinomycin D. These results suggest that the conformational features of (CG) segments may serve in regulatory functions of DNA. ^

Mixed spatial and nonspatial problems in location based services

With hundreds of millions of users reporting locations and embracing mobile technologies, Location Based Services (LBSs) are raising new challenges. In this dissertation, we address three emerging problems in location services, where geolocation data plays a central role. First, to handle the unprecedented growth of generated geolocation data, existing location services rely on geospatial database systems. However, their inability to leverage combined geographical and textual information in analytical queries (e.g. spatial similarity joins) remains an open problem. To address this, we introduce SpsJoin, a framework for computing spatial set-similarity joins. SpsJoin handles combined similarity queries that involve textual and spatial constraints simultaneously. LBSs use this system to tackle different types of problems, such as deduplication, geolocation enhancement and record linkage. We define the spatial set-similarity join problem in a general case and propose an algorithm for its efficient computation. Our solution utilizes parallel computing with MapReduce to handle scalability issues in large geospatial databases. Second, applications that use geolocation data are seldom concerned with ensuring the privacy of participating users. To motivate participation and address privacy concerns, we propose iSafe, a privacy preserving algorithm for computing safety snapshots of co-located mobile devices as well as geosocial network users. iSafe combines geolocation data extracted from crime datasets and geosocial networks such as Yelp. In order to enhance iSafe's ability to compute safety recommendations, even when crime information is incomplete or sparse, we need to identify relationships between Yelp venues and crime indices at their locations. To achieve this, we use SpsJoin on two datasets (Yelp venues and geolocated businesses) to find venues that have not been reviewed and to further compute the crime indices of their locations. Our results show a statistically significant dependence between location crime indices and Yelp features. Third, review centered LBSs (e.g., Yelp) are increasingly becoming targets of malicious campaigns that aim to bias the public image of represented businesses. Although Yelp actively attempts to detect and filter fraudulent reviews, our experiments showed that Yelp is still vulnerable. Fraudulent LBS information also impacts the ability of iSafe to provide correct safety values. We take steps toward addressing this problem by proposing SpiDeR, an algorithm that takes advantage of the richness of information available in Yelp to detect abnormal review patterns. We propose a fake venue detection solution that applies SpsJoin on Yelp and U.S. housing datasets. We validate the proposed solutions using ground truth data extracted by our experiments and reviews filtered by Yelp.

Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

Fatores de virulência, resistência ao estresse osmótico e susceptibilidade de isolados de Candida tropicalis oriundos de ambiente costeiro do nordeste brasileiro

Several studies have been developed regarding health risks associated with the recreational use of beaches contaminated with domestic sewage. These wastes contain various microorganisms, including Candida tropicalis, etiologic agent of both superficial infections such as systemic, as well as indicator of fecal contamination for the environment. In this context, the objective of this study was to characterize C. tropicalis isolates from the sandy beach of Ponta Negra, Natal, Rio Grande do Norte, Brazil, regarding the expression of in vitro virulence factors, adaptation to osmotic stress and susceptibility to antifungal drugs. We analyzed 62 environmental isolates of C. tropicalis and observed a great variation between them for the various virulence factors evaluated. In general, environmental isolates were more adherent to CEBH than C. tropicalis ATCC13803 reference strain, besides the fact they were also highly biofilm producers. In relation to morphogenesis, most isolates presented wrinkled phenotype in Spider medium (34 isolates, 54.8 %). When assessing enzyme activity, most isolates had higher proteinase production than C. tropicalis ATCC13803 reference strain. In addition, 35 isolates (56.4 %) had high hemolytic activity (hemolysis index > 55). With regard to C. tropicalis resistance to osmotic stress, 85.4% of the isolates were able to grow in a liquid medium containing 15% sodium chloride, corroborating to high survival capacity described for this yeast at marine environment. Finally, with regard to sensitivity to antifungal drugs, it was observed high resistance to the azoles tested, with the occurrence of the "Low-high" phenomenon and similar effect to the paradoxical growth which occurs to the echinocandins. For the three azoles tested we verified that 15 strains were resistant (24.2 %). Some strains were also resistant to amphotericin B (14 isolates, 22.6 %), while all of them were sensitive for the echinocandins tested. Therefore, our results demonstrate that C. tropicalis isolated from the sand of northeast of Brazil can fully express virulence attributes and showed a high persistence capacity on the coastal environment, in addition of being significantly resistant to most applied antifungals in current clinical practice. This constitutes a potential health risk to visitors of this environment, especially immunocompromised individuals and those with extreme age range.

Polymer Process Partitioning: Extruding Plastic Pipe

When plastic pipe is solidified, it proceeds through a long cooling chamber. Inside this chamber, inside the hollow extrudate, the plastic is molten, and this inner surface solidifies last. Sag, the flow due to the self-weight of the molten plastic, then happens in this cooling chamber, and sometimes, thickened regions (called knuckles) arise in the lower quadrants, especially of large diameter thickwalled pipes. To compensate for sag, engineers normally shift the die centerpiece downward. This thesis focuses on the consequences of this decentering. Specifically, when the molten polymer is viscoelastic, as is normally the case, a downward lateral force is exerted on the mandrel. Die eccentricity also affects the downstream axial force on the mandrel. These forces govern how rigidly the mandrel must be attached (normally, on a spider die). We attack this flow problem in eccentric cylindrical coordinates, using the Oldroyd 8-constant constitutive model framework. Specifically, we revise the method of Jones (1964), called polymer process partitioning. We estimate both axial and lateral forces. We develop a corresponding map to help plastics engineers predict the extrudate shape, including extrudate knuckles. From the mass balance over the postdie region, we then predict the shape of the extrudate entering the cooling chamber. We further include expressions for the stresses in the extruded polymer melt. We include detailed dimensional worked examples to show process engineers how to use our results to design pipe dies, and especially to suppress extrudate knuckling.