Wolbachia pipientis: intracellular infection and pathogenesis in Drosophila

Wolbachia pipientis is a vertically transmitted, obligate intracellular symbiont of arthropods. The bacterium is best known for its ability to manipulate host reproductive biology where it can induce cytoplasmic incompatibility, parthenogenesis, feminization and male-killing. In addition to the various reproductive phenotypes it generates through interaction with host reproductive tissue it is also known to infect somatic tissues. However, relatively little is known about the consequences of infection of these tissues with the exception that in some hosts Wolbachia acts as a classical mutualist and in others a pathogen, dramatically shortening adult insect lifespan. Manipulation experiments have demonstrated that the severity of Wolbachia-induced effects on the host is determined by a combination of host genotype, Wolbachia strain, host tissue localization, and interaction with the environment. The recent completion of the whole genome sequence of Wolbachia pipientis wMel strain indicates that it is likely to use a type IV secretion system to establish and maintain infection in its host. Moreover, an unusual abundance of genes encoding proteins with eukaryotic-like ankyrin repeat domains suggest a function in the various described phenotypic effects in hosts.

The potential of virulent Wolbachia to modulate disease transmission by insects

A virulent strain of Wolbachia has recently been identified in Drosophila that drastically reduces adult lifespan. It has been proposed that this phenotype might be introduced into insect disease vector populations to reduce pathogen transmission. Here we model the requirements for spread of such an agent and the associated reduction in disease transmission. First, a simulation of mosquito population age structure was used to describe the age distribution of mosquitoes transmitting dengue virus. Second, given varying levels of cytoplasmic incompatibility and fecundity effect, the maximum possible longevity reduction that would allow Wolbachia to invade was obtained. Finally, the two models were combined to estimate the reduction in disease transmission according to different introduction frequencies. With strong CI and limited effect of fecundity, an introduction of Wolbachia with an initial frequency of 0.4 could result in a 60–80% reduction of transmitting mosquitoes. Greater reductions are possible at higher initial release rates.

An everyday nostalgia: Memory and the fictions of belonging

In 1984, George Orwell presented the future as a dystopian vision, where everyday existence was governed and redefined by an oppressive regime. Winston Smith's daily duties at the Ministry of Truth involved the invention, rewriting and erasing of fragments of history as a means of perpetuating contentment, uniformity and control. History, as Orwell described it in the novel 'was a palimpsest, scraped clean and reinscribed exactly as often as was necessary.' More that a quarter of a century after the publication of 1984, Michel Foucault discussed the cinematic representation and misrepresentation of French history and identity in terms of what he called the manipulation of 'popular memory'. In what was tantamount to a diluted version of Orwell's palimpsestic histories, Foucault stated that 'people are not shown what they were, but what they must remember having been.' This paper will investigate notions of memory, identity and the everyday through a discussion of the community of Celebration in Florida. Conceived in the 1990s, Celebration was designed around a fictionalised representation of pre 1940s small town America, using nostalgia for a mythologised past to create a sense of comfort, community and conformity among its residents. Adapting issues raised by Orwell, Foucault and Baudrillard, this paper will discuss the way in which architecture, like film and literature, can participate in what Foucault discussed as the manipulation of popular memory, inducing and exploiting a nostalgia for an everyday past that that never really existed.

Multicomponent reversible reactions inside a porous catalyst pellet

This work deals with a solution method to handle multicomponents reversible reactions occurring inside a porous catalyst pellet. The complexity of this problem arises from the fact that the effective diffusivities and Biot number, which characterizes the external mass transfer, are different for each chemical species. In mathematical terms, this means that each chemical species has its own subspace and, therefore, when the technique of finite integral transform is applied to solve this multicomponent problem, each chemical species is associated with its own integral transform kernel. The analytical solutions obtained for this problem are compact and simple for any further manipulation. Application of this result to the catalytic reforming of C7 hydrocarbon system is shown in this paper.

(FAB12_2_019) National identity at Arakawa & Gins’ Site of Reversible Destiny—Yoro, Japan

This paper examines the manipulation of forms of the traditional Japanese stroll garden at Site of Reversible Destiny, a tourist park designed by the New Yorkbased collaborators Shusaku Arakawa and Madeline Gins. Landscape and its representations are central to the construction of national identity in Japan since the cultural distinctiveness of the Japanese people has been argued to rest on their unique relationship to nature and the country’s idiosyncratic geography. The stroll garden of the larger estates and palaces of the Edo period (1615–1867) developed out of earlier temple gardens and most public parks in contemporary Japan are in the grounds of these historic sites or reproduce their forms.

Spatial Technologies: What use are they to managers of environmental lands?

This paper reviews the potential use of three types of spatial technology to land managers, namely satellite imagery, satellite positioning systems and supporting computer software. Developments in remote sensing and the relative advantages of multispectral and hyperspectral images are discussed. The main challenge to the wider use of remote sensing as a land management tool is seen as uncertainty whether apparent relationships between biophysical variables and spectral reflectance are direct and causal, or artefacts of particular images. Developments in satellite positioning systems are presented in the context of land managers’ need for position estimates in situations where absolute precision may or may not be required. The role of computer software in supporting developments in spatial technology is described. Spatial technologies are seen as having matured beyond empirical applications to the stage where they are useful and reliable land management tools. In addition, computer software has become more user-friendly and this has facilitated data collection and manipulation by semi-expert as well as specialist staff.

Seeing is not (necessarily) believing

We doubt that theory of mind can be sufficiently demonstrated without reliance on verbal tests. Where language is the major tool of social manipulation, an effective theory of mind must use language as an input. We suspect, therefore, that in this context, prelinguistic human and nonhuman minds are more alike than are human pre- and postlinguistic minds.

An investigation of the interrelationship between manipulative therapy-induced hypoalgesia and sympathoexcitation

Objective: To investigate a proposed model in which manipulative therapy produces a treatment-specific initial hypoalgesic and sympathoexcitatory effect by activating a descending pain inhibitory system. The a priori hypothesis tested was that manipulative therapy produces mechanical hypoalgesia and sympatho-excitation beyond that produced by placebo or control. Furthermore, these effects would be correlated, thus supporting the proposed model. Design: A randomized, double-blind, placebo-controlled, repeated-measures study of the initial effect of treatment. Setting: Clinical neurophysiology laboratory. Subjects: Twenty-four subjects (13 women and 11 men; mean age, 49 yr) with chronic lateral epicondylalgia (average duration, 6.2 months). Intervention: Cervical spine lateral glide oscillatory manipulation, placebo and control. Outcome Measures: Pressure pain threshold, thermal pain threshold, pain-free grip strength test, upper limb tension test 2b, skin conductance, pileous and glabrous skin temperature and blood flux. Results: Treatment produced hypoalgesic and sympathoexcitatory changes significantly grater than those of placebo and control (p < .03). Confirmatory factor-analysis modeling, which was performed on the pain-related measures and the indicators of sympathetic nervous system function, demonstrated a significant correlation (r = .82) between the latencies of manipulation-induced hypoalgesia and sympathoexcitation. The Lagrange Multiplier test and Wald test indicated that the two latent factors parsimoniously and appropriately represented their observed variables. Conclusions: Manual therapy produces a treatment-specific initial hypoalgesic and sympathoexcitatory effect beyond that of placebo or control. The strong correlation between hypoalgesic and sympathoexcitatory effects suggests that a central control mechanism might be activated by manipulative therapy.

The effect of imposed and self-selected computer monitor height on posture and gaze angle

Objective: The objectives were to determine the postural consequences of varying computer monitor height and to describe self-selected monitor heights and postures. Design: The design involved experimental manipulation of computer monitor height, description of self-selected heights, and measurement of posture and gaze angles. Background. Disagreement exists with regard to the appropriate height of computer monitors. It is known that users alter both head orientation and gaze angle in response to changes in monitor height; however the relative contribution of atlanto-occipital and cervical flexion to the change in head rotation is unknown. No information is available with regard to self-selected monitor heights. Methods. Twelve students performed a tracking task with the monitor placed at three different heights. The subjects then completed eight trials in which monitor height was first self-selected. Sagittal postural and gaze angle data were determined by digitizing markers defining a two-dimensional three-link model of the trunk, cervical spine and head. Results. The 27 degrees change in monitor height imposed was, on average, accommodated by 18 degrees of head inclination and a 9 degrees change in gaze angle relative to the head. The change in head inclination was achieved by a 6 degrees change in trunk inclination, a 4 degrees change in cervical flexion, and a 7 degrees change in atlanto-occipital flexion. The self-selected height varied depending on the initial monitor height and inclination. Conclusions. Self-selected monitor heights were lower than current 'eye-level' recommendations. Lower monitor heights are likely to reduce both visual and musculoskeletal discomfort. Relevance Musculoskeletal and visual discomfort may be reduced by placing computer monitors lower than currently recommended. (C) 1998 Elsevier Science Ltd. All rights reserved.

Teleportation using coupled oscillator states

We analyze the fidelity of teleportation protocols, as a function of resource entanglement, for three kinds of two-mode oscillator states: states with fixed total photon number, number states entangled at a beam splitter, and the two-mode squeezed vacuum state. We define corresponding teleportation protocols for each case including phase noise to model degraded entanglement of each resource.

Polyinosinic acid and polycationic liposomes attenuate the hepatic clearance of circulating plasmid DNA

DNA that enters the circulation is rapidly cleared both by tissue uptake and by DNase-mediated degradation. In this study, we have examined the uptake of linear plasmid DNA in an isolated perfused liver model and following intra-arterial administration to rats. We found that the DNA was rapidly taken up by the isolated perfused liver without degradation. The single-pass extraction ratio was 0.76 +/- 0.05, the mean transit time was 15.3 +/- 3.6 s, and the volume of distribution was 0.29 +/- 0.07 ml/g. Hepatic uptake was saturable and was inhibited by polyinosinic acid or polycationic liposomes but not by condensation of the DNA with polylysine. When the linear plasmid DNA was administered in vivo, plasma half-life was 3.1 +/- 0.2 min, volume of distribution was 670 +/- 85 ml/kg, and clearance was 32 +/- 4 min. Coadministration of cationic liposomes decreased the volume of distribution to 180 +/- 28 ml/kg as well as the half-life (2.6 +/- 0.2 min). By contrast, polyinosinic acid significantly increased the circulating half-life (7.7 +/- 0.5 min), decreased the volume of distribution (95 +/- 17 ml/kg), and partially inhibited DNA degradation. When administered along with the liposomes and the polyinosinic acid, the distribution of plasmid-derived radioactivity decreased in the liver and increased in most other peripheral tissues. This study shows that pharmacological manipulation of the uptake and degradation of DNA can alter its distribution and clearance in vivo. These results may be useful in optimizing gene delivery procedures for in vivo gene therapy.

Local-global processing in early-onset schizophrenia: Evidence for an impairment in shifting the spatial scale of attention

In this study we report the results of two experiments on visual attention conducted with patients with early-onset schizophrenia. These experiments investigated the effect of irrelevant spatial-scale information upon the processing of relevant spatial-scale information, and the ability to shift the spatial scale of attention, across consecutive trials, between different levels of the hierarchical stimulus. Twelve patients with early-onset schizophrenia and matched controls performed local-global tasks under: (1) directed attention conditions with a consistency manipulation and (2) divided-attention conditions. In the directed-attention paradigm, the early-onset patients exhibited the normal patterns of global advantage and interference, and were not unduly affected by the consistency manipulation. Under divided-attention conditions, however, the early-onset patients exhibited a local-processing deficit. The source of this local processing deficit lay in the prolonged reaction time to local targets, when these had been preceded by a global target, but not when preceded by a local target. These findings suggest an impaired ability to shift the spatial scale of attention from a global to a local spatial scale in early-onset schizophrenia. (C) 2003 Elsevier Science (USA). All rights reserved.

Response selection deficits in melancholic but not nonmelancholic unipolar major depression

One consistent functional imaging finding from patients with major depression has been abnormality of the anterior cingulate cortex (ACC). Hypoperfusion has been most commonly reported, but some studies suggest relative hyperperfusion is associated with response to somatic treatments. Despite these indications of the possible importance of the ACC in depression there have been relatively few cognitive studies ACC function in patients with major depression. The present study employed a series of reaction time (RT) tasks involving selection with melancholic and nonmelancholic depressed patients, as well as age-matched controls. Fifteen patients with unipolar major depression (7 melancholic, 8 nonmelancholic) and 8 healthy age-matched controls performed a series of response selection tasks (choice RT, spatial Stroop, spatial stimulus-response compatibility (SRC), and a combined Stroop + SRC condition). Reaction time and error data were collected. Melancholic patients were significantly slower than controls on all tasks but were slower than nonmelancholic patients only on the Stroop and Stroop + SRC conditions. Nonmelancholic patients did not differ from the control group on any task. The Stroop task seems crucial in differentiating the two depressive groups, they did not differ on the choice RT or SRC tasks. This may reflect differential task demands, the SRC involved symbolic manipulation that might engage the dorsal ACC and dorsolateral prefrontal cortex (DLPFC) to a greater extent than the, primarily inhibitory, Stroop task which may engage the ventral ACC and orbitofrontal cortex (OFC). This might suggest the melancholic group showed a greater ventral ACC-OFC deficit than the nonmelancholic group, while both groups showed similar dorsal ACC-DLPFC deficit.

The initial effects of a Mulligan's mobilization with movement technique on dorsiflexion and pain in subacute ankle sprains

Physiotherapists frequently use manipulative therapy techniques to treat dysfunction and pain resulting from ankle sprain. This study investigated whether a Mulligan's mobilization with movement (MWM) technique improves talocrural dorsiflexion, a major impairment following ankle sprain, and relieves pain in subacute populations. Fourteen subjects with subacute grade II lateral ankle sprains served as their own control in a repeated measures, double-blind randomized controlled trial that measured the initial effects of the MWM treatment on weight bearing dorsiflexion and pressure and thermal pain threshold. The subacute ankle sprain group studied displayed deficits in dorsiflexion and local pressure pain threshold in the symptomatic ankle. Significant improvements in dorsiflexion occurred initially post-MWM (F-(2,F-26) 7.82, P = 0.002), but no significant changes in pressure or thermal pain threshold were observed after the treatment condition. Results indicate that the MWM treatment for ankle dorsiflexion has a mechanical rather than hypoalgesic effect in subacute ankle sprains. The mechanism by which this occurs requires investigation if we are to better understand the role of manipulative therapy in ankle sprain management. (C) 2003 Elsevier Ltd. All rights reserved.