Interleukin-12 is required for control of the growth of attenuated aromatic-compound-dependent salmonellae in BALB/c mice: role of gamma interferon and macrophage activation

The attenuated S. typhimurium SL3261 (aroA) strain causes mild infections in BALB/c mice. We were able to exacerbate the disease by administering anti-interleukin-12 (IL-12) antibodies, resulting in bacterial counts in the spleens and livers of anti-IL-12-treated mice that were 10- to 100-fold higher than the ones normally observed in premortem mice; yet the animals showed only mild signs of illness. Nevertheless, they eventually died of a slow, progressive disease. Mice infected with salmonellae become hypersusceptible to endotoxin. We found that IL-12 neutralization prevented the death of infected mice following subcutaneous injection of lipopolysaccharide. Granulomatous lesions developed in the spleens and livers of control animals, as opposed to a widespread infiltration of mononuclear cells seen in the organs of anti-IL-12-treated mice. In the latter (heavily infected), salmonellae were seen within mononuclear cells, indicating an impairment of the bactericidal or bacteriostatic ability of the phagocytes in the absence of biologically active IL-12. Gamma interferon (IFN-gamma) levels were reduced in the sera and tissue homogenates from anti-IL-12-treated mice compared to those in control animals. Furthermore, fluorescence-activated cell sorter analysis on spleen cells showed that IL-12 neutralization impaired the upregulation of I-Ad/I-Ed antigens on macrophages from infected mice. Inducible nitric oxide synthase and IFN-gamma mRNA production was down-regulated in anti-IL-12-treated mice, which also showed an increased production of IL-10 mRNA and a decrease in nitric oxide synthase activity in the tissues. Administration of recombinant IFN-gamma to anti-IL-12-treated mice was able to restore host resistance, granuloma formation, and expression of major histocompatibility complex class II antigens in F4/80(+) and CD11b+ spleen cells.     

Inheritance Of Resistance To Mammalian Herbivores and Of Plant Defensive Chemistry In A <Emphasis Type="Italic">Eucalyptus</Emphasis> Species

Hybridization in plants provides an opportunity to investigate the patterns of inheritance of hybrid resistance to herbivores, and of the plant mechanisms conferring this resistance such as plant secondary metabolites. We investigated how inter-race differences in resistance of Eucalyptus globulus to a generalist mammalian herbivore, Trichosurus vulpecula, are inherited in their F₁ hybrids. We assessed browsing damage of three-year-old trees in a common environment field trial on four hybrid types of known progeny. The progency were artificial intra-race crosses and reciprocal inter-race F₁ hybrids of two geographically distinct populations (races) of E. globulus; north-eastern Tasmania and south-eastern Tasmania. Populations of trees from north-eastern Tasmania are relatively susceptible to browsing by T. vulpecula, while populations from south-eastern Tasmania are more resistant. We assessed the preferences of these trees in a series of paired feeding trials with captive animals to test the field trial results and also investigated the patterns of inheritance of plant secondary metabolites. Our results demonstrated that the phenotypic expression of resistance of the inter-race F₁ hybrids supported the additive pattern of inheritance, as these hybrids were intermediate in resistance compared to the pure parental hybrids. The expression of plant secondary metabolites in the F₁ hybrids varied among groups of individual compounds. The most common pattern supported was dominance towards one of the parental types. Together, condensed tannins and essential oils appeared to explain the observed patterns of resistance among the four hybrid types. While both chemical groups were inherited in a dominant manner in the inter-race F₁ hybrids, the direction of dominance was opposite. Their combined concentration, however, was inherited in an additive manner, consistent with the phenotypic differences in browsing.     

Longitudinal associations between hostility in adolescents' family relationships and friendships and hostility in their romantic relationships.

This study examined longitudinal predictors of hostility in adolescents' romantic relationships. The sample included 110 adolescents and their parents from 72 families. Observational measures of parents' marital hostility and parent-child hostility and self-reports of hostility in close friendships were collected when adolescents ranged from 14 to 16 years old. Three years later, when they were 17 to 19 years old, adolescents reported on the hostility in their romantic relationships. Results indicated that hostility in parents' marital relationships and in adolescents' friendships accounted for independent variance in hostility in adolescents' later romantic relationships. Results highlight the importance of both family relationships and friendships for predicting hostility in adolescents' romantic relationships over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Retrospective mapping of burnt areas in Central Siberia using a modification of the normalised difference water index

The boreal forest contains almost half the total carbon pool of world forest ecosystems, and so has a very significant role in global biogeochemical cycles. The flux of greenhouse gases in and out of these forests is influenced strongly by disturbances such as diseases, logging and predominantly fire. It is important to quantify these disturbances to enable the modelling of major greenhouse gases. However, because of the remoteness and vastness of the boreal forest, little data is available on the type, extent, frequency and severity of these disturbances in Siberia. For burnt areas, two of the more responsive wavelengths are the short wave infra-red (SWIR) and the near infra-red (NIR). These produce a vegetation index, the normalised difference SWIR (NDSWIR) capable of detecting retrospective disturbances. Here we combine the NDSWIR from MODIS imagery acquired in the summer of 2003 with thermal anomaly data from 1992 to 2003 to detect and date areas which burnt at some point between 1992 and 2003. The semi-automated method is called SWIR and Thermal ANomalies for Detecting Disturbances (STANDD) and is complemented by an Normalised Difference Vegetation Index (NDVI) differencing method using MODIS 2002 and 2003 imagery to ensure reliable detection of area burnt in the year of image acquisition (i.e. 2003). The area of this study covers approximately 3 million km² stretching from Lake Baikal in the south to the Laptev Sea in the north, above the Arctic Circle. Landsat ETM+ images were used to validate the shape and areal extent of the burnt areas resulting in an 81% overall accuracy with a kappa coefficient of agreement of 0.63.     

Coalescence of levitated polystyrene microspheres

The slow, laser-induced coalescence of two conjoined, polystyrene spheres levitated in a quadrupole ion trap is investigated by monitoring optical morphology dependent resonances (MDRs) appearing in the fluorescence emission spectrum. The heated bisphere is driven by surface tension to become a single, larger sphere with a volume equal to the combined volumes of the two initial spheres. In the final stage of the structural transformation the particle is a prolate spheroid whose dimensions are ascertained by analyzing frequency shifts of the non-degenerate azimuthal MDRs. The relaxation time for the deformed viscous sphere is used to estimate the polystyrene viscosity and temperature. The study highlights the feasibility of using a temperature-controlled quadrupole ion trap to investigate the coalescence dynamics of viscous microstructures free from the perturbative effects of any solvent or substrate.     

Rhetoric and the recovered memory debate.

Examines arguments about repression and dissociation in recent writings on the debate about the veracity of recovered memories of childhood abuse. Using the contributions of rhetorical psychology, discursive psychology, and conversational studies of argumentation, the authors studied the deployment of repression and dissociation by supporters of recovered memory, the refutations of skeptics, and the means by which arguments and counter-arguments were presented as factual. Supporters situate repression and dissociation within a long tradition of scholarly inquiry and draw on clients' personal accounts. Skeptics deny the existence of scientific evidence for the concept of repression. They suggest that dissociation, while a plausible phenomenon, cannot justifiably explain recovered memories. The implications for stasis and change within the recovered memory debate are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using artificial neural networks to develop prediction models for sensory-instrumental relationships; an overview

The possibility of using neural networks for modelling instrumental-sensory relationships is investigated. The advantages and disadvantages of using artificial neural networks (ANNs) are considered and compared with those of the multivariate linear methods of principal components regression (PCR) and partial least squares regression (PLS). In particular the problem of modelling nonlinear relationships is considered. It is concluded that ANNs cannot replace PCR and PLS for linear relationships but do offer potential for modelling nonlinear relationships.     

Impact of Statistical Multiplexing on Voice Quality in Cellular Networks

This paper examines the quality of transmission of voice over cellular, packet-switched networks. The medium access mechanism in the uplink is simulated under various statistical multiplexing scenarios in order to assess the effect of front-end clipping on voice quality. Moreover, the simulation is implemented in a real-time demonstration platform utilized to acquire subjective indicators of voice quality by performing Mean Opinion Score (MOS) tests. Results from the MOS tests are reported, and an analysis of the obtained speech samples is presented. Finally, the results are summarized and potential further directions for the simulation tool and the speech models are discussed.     

Relearning face-name associations in early Alzheimer's disease.

Preliminary evidence for the effectiveness of cognitive rehabilitation interventions based on errorless learning principles in early-stage Alzheimer's disease (AD) was provided by Clare et al. (1999, 2000, 2001). The present study extends these findings in a controlled trial. Twelve participants meeting criteria for probable AD, with Mini-Mental State Examination scores of 18 or above, were trained in face-name associations using an effortless learning paradigm. Training produced a significant group improvement in recall of trained, but not control, items. Gains were largely maintained 6 months later, in the absence of practice. There were differences in individual response to intervention. Results did not differ according to medication status, and the intervention had no adverse effects on self-reported well-being, but participants who were more aware of their memory difficulties achieved better outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)