Dual processes in recognition: Does a focus on measurement operations provide a sufficient foundation?

Current theoretical thinking about dual processes in recognition relies heavily on the measurement operations embodied within the process dissociation procedure. We critically evaluate the ability of this procedure to support this theoretical enterprise. We show that there are alternative processes that would produce a rough invariance in familiarity (a key prediction of the dual-processing approach) and that the process dissociation procedure does not have the power to differentiate between these alternative possibilities. We also show that attempts to relate parameters estimated by the process dissociation procedure to subjective reports (remember-know judgments) cannot differentiate between alternative dual-processing models and that there are problems with some of the historical evidence and with obtaining converging evidence. Our conclusion is that more specific theories incorporating ideas about representation and process are required.

The relationship between radiation-induced chemical processes and transverse relaxation times in polymer gel dosimeters

The effects of ionizing radiation in different compositions of polymer gel dosimeters are investigated using FT-Raman spectroscopy and NMR T-2 relaxation times. The dosimeters are manufactured from different concentrations of comonomers (acrylamide and N,N'-methylene-bis-acrylamide) dispersed in different concentrations of an aqueous gelatin matrix. Results are analysed using a model of fast exchange of magnetization between three proton pools. The fraction of protons in each pool is determined using the known chemical composition of the dosimeter and FT-Raman spectroscopy. Based on these results, the physical and chemical processes in interplay in the dosimeters are examined in view of their effect on the changes in T-2 The precipitation of growing macroradicals and the scavenging of free radicals by gelatin are used to explain the rate of polymerization. The model describes the changes in T-2 as a function of the absorbed dose up to 50 Gy for the different compositions. This is expected to aid the theoretical design of new, more efficient dosimeters, since it was demonstrated that the optimum dosimeter (i.e, with the lowest dose resolution) must have a range of relaxation times which match the range of T-2 values which can be determined with the lowest uncertainty using an MRI scanner.

Developing qualitative career assessment processes

Assessment has been integral to career counseling since the early 1900s. During that time, the greatest amount of attention was focused on quantitative assessment. Thus, there is still very little to guide the development and conduct of qualitative assessment in career counseling. The authors present an overview of qualitative career assessment and its theoretical underpinnings and propose suggestions that could guide the development of qualitative career assessment instruments.

Mental rotation processes in mathematically gifted boys: An fMRI investigation

The functional brain organisation of mathematically gifted adolescents may be different from those of average mathematical ability. In this study we used fMRI to examine the neural circuitry that mediates the performance of mathematically gifted boys and average ability controls while engaged in mental rotation. Eight math gifted male adolescents and five average ability male adolescents were presented 18 control and 18 mental rotation trials in two separate blocks. Participants selected one of four test stimuli to match the target stimulus by pressing one of four fibreoptic buttons. The control task required a simple 'best match' for the target stimulus. EPI scans were acquired on a 3-T MR scanner and a fixed effects statistical analysis (SPM99) was used to identify areas of significant activation in the rotation tasks, for the two groups. The results indicate that during mental rotation both groups activate the parietal lobes bilaterally, though to different levels. Moreover, the math gifted are uniformly bilateral in their pattern of activation, and engage some anterior regions not found in those of average ability. These regions include bilateral prefrontal cortex and the right anterior cingulate, which may serve to heighten concentration, and to optimise the pre-planning of purposeful actions.

Effects of Nasal Continuous Positive Airway Pressure Treatment on Oxidative Stress and Adiponectin Levels in Obese Patients with Obstructive Sleep Apnea

Background: Obesity and obstructive sleep apnea (OSA) are both associated with the prevalence of major cardiovascular illnesses and certain common factors they are considered responsible for, such as stress oxidative increase, sympathetic tonus and resistance to insulin. Objective: The aim of the present study was to compare the effect of continuous positive airway pressure (CPAP) on oxidative stress and adiponectin levels in obese patients with and without OSA. Methods: Twenty-nine obese patients were categorized into 3 groups: group 1: 10 individuals without OSA (apnea-hypopnea index, AHI <= 5) who did not have OSA diagnosed at polysomnography; group 2: 10 patients with moderate to severe OSA (AHI >= 20) who did not use CPAP; group 3: 9 patients with moderate to severe OSA (AHI >= 20) who used CPAP. Results: Group 3 showed significant differences before and after the use of CPAP, in the variables of diminished production of superoxide, and increased nitrite and nitrate synthesis and adiponectin levels. Positive correlations were seen between the AHI and the superoxide production, between the nitrite and nitrate levels and the adiponectin levels, between superoxide production and the HOMA-IR, and between AHI and the HOMA-IR. Negative correlations were found between AHI and the nitrite and nitrate levels, between the superoxide production and that of nitric oxide, between the superoxide production and the adiponectin levels, between AHI and the adiponectin levels, and between the nitrite and nitrate levels and the HOMA-IR. Conclusions: This study demonstrates that the use of CPAP can reverse the increased superoxide production, the diminished serum nitrite, nitrate and plasma adiponectin levels, and the metabolic changes existing in obese patients with OSA. Copyright (C) 2009 S. Karger AG, Basel

Effect of phosphate binders on oxidative stress and inflammation markers in hemodialysis patients

It has been suggested that phosphate binders may reduce the inflammatory state of hemodialysis (HD) patients. However, it is not clear whether it has any effect on oxidative stress. The objective of this study was to evaluate the effect of sevelamer hydrochloride (SH) and calcium acetate (CA) on oxidative stress and inflammation markers in HD patients. Hemodialysis patients were randomly assigned to therapy with SH (n=17) or CA (n=14) for 1 year. Before the initiation of therapy (baseline) and at 12 months, we measured in vitro reactive oxygen species (ROS) production by stimulated and unstimulated polymorphonuclear neutrophils and serum levels of tumor necrosis factor alpha, interleukin-10, C-reactive protein, and albumin. There was a significant reduction of spontaneous ROS production in both groups after 12 months of therapy. There was a significant decrease of Staphylococcus aureus stimulated ROS production in the SH group. There was a significant increase in albumin serum levels only in the SH group. In the SH group, there was also a decrease in the serum levels of tumor necrosis factor alpha and C-reactive protein. Our results suggest that compared with CA treatment, SH may lead to a reduction in oxidative stress and inflammation. Therefore, it is possible that phosphate binders exert pleiotropic effects on oxidative stress and inflammation, which could contribute toward decreasing endothelial injury in patients in HD.

Limiting conditional distributions for birth-death processes

In a recent paper [16], one of us identified all of the quasi-stationary distributions for a non-explosive, evanescent birth-death process for which absorption is certain, and established conditions for the existence of the corresponding limiting conditional distributions. Our purpose is to extend these results in a number of directions. We shall consider separately two cases depending on whether or not the process is evanescent. In the former case we shall relax the condition that absorption is certain. Furthermore, we shall allow for the possibility that the minimal process might be explosive, so that the transition rates alone will not necessarily determine the birth-death process uniquely. Although we shall be concerned mainly with the minimal process, our most general results hold for any birth-death process whose transition probabilities satisfy both the backward and the forward Kolmogorov differential equations.

The effect of emotional and attentional processes on blink startle modulation and on electrodermal responses

Emotional accounts of startle modulation predict that startle is facilitated if elicited during aversive foreground stimuli. Attentional accounts hold that startle is enhanced if startle-eliciting stimulus and foreground stimulus are in the same modality. Visual and acoustic foreground stimuli and acoustic startle probes were employed in aversive differential conditioning and in a stimulus discrimination task. Differential conditioning was evident in electrodermal responses and blink latency shortening in both modalities, but effects on magnitude facilitation were found only for visual stimuli. In the discrimination task, skin conductance responses, blink latency shortening, and blink magnitude facilitation were larger during to-be-attended stimuli regardless of stimulus modality. The present results support the notion that attention and emotion can affect blink startle modulation during foreground stimuli.

Computer technology - A political player in social policy processes

The absence of considerations of technology in policy studies reinforces the popular notion that technology is a neutral tool, Through an analysis of the role played by computers in the policy processes of Australia's Department of Social Security, this paper argues that computers are political players in policy processes, Findings indicate that computers make aspects of the social domain knowable and therefore governable, The use of computers makes previously infeasible policies possible, Computers also operate as bureaucrats and as agents of client surveillance. Increased policy change, reduced discretion and increasingly targeted and complex policies can be attributed to the use of computer technology, If policy processes are to be adequately understood and analysed, then the role of technology in those processes must be considered.

Galectin-3 plays a modulatory role in the life span and activation of murine neutrophils during early Toxoplasma gondii infection

Galectins are beta-galactoside-binding lectins involved in several biological processes and galectin-3 (Gal-3) is related to modulation of immune and inflammatory responses. This study aimed to evaluate the role of Gal-3 in the life span and biological functions of murine neutrophils during in vitro infection by virulent Toxoplasma gondii RH strain. Inflammatory peritoneal neutrophils (N phi) from C57BL/6 wildtype (WT) and Gal-3 knockout (KO) mice were cultured in the presence or absence of parasites and analyzed for phosphatidylserine (PS) exposure and cell death using Annexin-V and propidium iodide staining, and cell viability by MU assay. Cell toxicities determined by lactate dehydrogenase (LDH), degranulation by lysozyme release, and cytokine production were measured in NO culture supernatants. Phorbol myristate acetate (PMA)- or zymosan-dependent reactive oxygen species (ROS) were measured in N phi cultures. Our results demonstrated that Gal-3 is involved in the increase of the viable Not. number and the decrease of PS exposure and cell death following T. gondii infection. We also observed that Gal-3 downmodulates gondii-induced N phi toxicity as well as N phi degranulation regardless of infection. Furthermore, Gal-3 expression by N phi was associated with increased levels of IL-10 in the beginning and decreased levels of TNF-alpha later on, regardless of parasite infection, as well as with decreased levels of IL-6 and increased IL-12 levels, following early parasite infection. Our results also showed that Gal-3 suppresses PMA- but not zymosan-induced ROS generation in N phi following T. gondii infection. In conclusion, Gal-3 plays an important modulatory role by interfering in N phi life span and activation during early T gondii infection. (C) 2009 Elsevier GmbH. All rights reserved.

Ligaments of the Posterior and Lateral Talar Processes: MRI and MR Arthrography of the Ankle and Posterior Subtalar Joint with Anatomic and Histologic Correlation

OBJECTIVE. MRI and combined ankle and posterior subtalar MR arthrography in cadavers were used to evaluate the ligaments of the posterior and lateral talar processes. Subsequent anatomic and histologic correlation was performed. MATERIALS AND METHODS. Ten cadaveric ankles were used. Routine radiography and MRI were initially performed. Ankle and posterior subtalar MR arthrography, followed by anatomic and histologic analysis, was then performed to allow better assessment of the ligaments of the lateral and posterior talar process. RESULTS. In all subjects, MR arthrography provided superior delineation of the articular and periarticular structures, as well as the ligaments. The lateral talocalcaneal and medial talocalcaneal ligaments were best seen in the axial and coronal planes, respectively. The axial plane was best for visualizing the fibulotalocalcaneal ligament, and the sagittal plane was best for evaluating the posterior talocalcaneal ligament. The anterior and posterior talofibular ligaments and the posterior tibiotalar ligament (superficial and deep portions) were best seen in the axial plane. Histologic analysis was correlated to anatomic sectioning and showed the attachment sites of these ligaments. CONCLUSION. Combined ankle and posterior subtalar MR arthrography enhances visualization of the ligaments attaching to the posterior and lateral talar processes, including the posterior, lateral, and medial talocalcaneal and fibulotalocalcaneal ligaments.

Supplementation of Vitamin E, Vitamin C, and Zinc Attenuates Oxidative Stress in Burned Children: A Randomized, Double-Blind, Placebo-Controlled Pilot Study

The aim of this study was to investigate the effect of supplementation of vitamin E, vitamin C, and zinc on the oxidative stress in burned children. In a prospective double-blind placebo-controlled pilot study, 32 patients were randomized as no supplementation (n = 15) or antioxidant supplementation (n = 17) groups. Supplementation consisted of the antioxidant mixture of vitamin C (1.5 times upper intake level), vitamin E (1.35 times upper intake level), and zinc (2.0 times recommended dietary allowance) administered during 7 days starting on the second day of admittance into the hospital. Energy requirement was calculated by the Curreri equation, and protein input was 3.0 g/kg of ideal body mass index (percentile 50 degrees). Total antioxidant capacity of plasma and malondialdehyde were used to monitor oxidative stress. The time of wound healing was evaluated as the main clinical feature. Patients (age 54.2 +/- 48.9 months, 65.6% males), who exhibited 15.5 +/- 6.7% of total burn area, showed no differences in age and sex, when compared with controls. Intake of the administered antioxidants was obviously higher in treated subjects (P = .005), and serum differences were confirmed for vitamin E and C, but not for zinc (P = .180). There was a decrease in lipid peroxidation (malondialdehyde level) (P = .006) and an increase in vitamin E concentrations in the antioxidant supplementation group (P = .016). The time of wound healing was lower in the supplemented group (P < .001). The antioxidant supplementation through vitamin E and C and the mineral zinc apparently enhanced antioxidant protection against oxidative stress and allowed less time for wound healing. (J Burn Care Res 2009;30:859-866)

Folding processes and solitary waves in structural geology

Evolution of localized folding patterns in layered elastic and visco-elastic materials is reviewed in the context of compressed geological systems. The thin strut or plate embedded in a visco-elastic medium is used as an archetypal example to describe localized buckles which, in contrast to those from earlier formulations, appear in the absence of triggering imperfections. Structural and material effects are surveyed and important nonlinear characteristics are identified. A brief review of possible methods of analysis is conducted.