Brain potentials implicate temporal lobe abnormalities in criminal psychopaths.

Psychopathy is associated with abnormalities in attention and orienting. However, few studies have examined the neural systems underlying these processes. To address this issue, the authors recorded event-related potentials (ERPs) while 80 incarcerated men, classified as psychopathic or nonpsychopathic via the Hare Psychopathy Checklist-Revised (R. D. Hare, 1991, 2003), completed an auditory oddball task. Consistent with hypotheses, processing of targets elicited larger frontocentral negativities (N550) in psychopaths than in nonpsychopaths. Psychopaths also showed an enlarged N2 and reduced P3 during target detection. Similar ERP modulations have been reported in patients with amygdala and temporal lobe damage. The data are interpreted as supporting the hypothesis that psychopathy may be related to dysfunction of the paralimbic system--a system that includes parts of the temporal and frontal lobes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Circuit/device modeling at the quantum level

Quantum mechanical (QM) effects, which manifest when the device dimensions are comparable to the de Broglie wavelength, are becoming common physical phenomena in the current micro-/nano-meter technology era. While most novel devices take advantage of QM effects to achieve fast switching speed, miniature size, and extremely small power consumption, the mainstream CMOS devices (with the exception of EEPROMs) are generally suffering in performance from these effects. Solutions to minimize the adverse effects caused by QM while keeping the downscaling trend (technology feasibility aside) are being sought in the research community and industry-wide. This paper presents a perspective view of modeling approaches to quantum mechanical effects in solid-state devices at the device and circuit simulation levels. Specifically, the macroscopic modeling of silicon devices to include QM corrections in the classical transport framework is discussed. Both device and circuit models will be provided. On the quantum devices, such as the single electron junctions and transistors, the emphasis is placed on the principle of logic circuit operation     

Developing Supplier Capabilities: Market and Non-market Approaches

We explore the ways that component suppliers in a traditional US manufacturing region (Cleveland) have responded to their customers' demands for improved quality, cost, and delivery. We find that a surprising number (almost a third) have not responded by attempting systematic improvements in their production capabilities. However, two-thirds of suppliers have worked to improve their capabilities in these areas, adopting such policies as just-in-time and total quality management. Although many of the policies are inspired by Japanese management practices, the method of transfer makes far more use of market mechanisms (such as purchase of consulting services and hiring of employees who have experience implementing such practices), than in Japan. We examine the advantages and disadvantages of such market-based diffusion mechanisms.     

p-channel quantum-well heterostructure MI3SFET

A p-channel heterostructure MISFET-like device based on a quantum well with an underlying impurity layer is discussed. The device is based on an AlGaAs/GaAs heterostructure with a recessed-gate geometry and uses Zn-diffused refractory-metal contacts. The 4100 cm²/V-s hole mobility obtained in this inverted-interface structure at 77 K is comparable to that achieved in normal-interface AlGaAs/GaAs heterostructures. Transconductance and K-factor values as high as 52 mS/mm and 140 mS/V-mm, respectively, are obtained at 77 K in p-channel FETs with 2.0-μm gate lengths and 6.0-μm source-drain spacings, representing state-of-the-art values for p-HFETs at similar dimensions     

Peripheral-type benzodiazepine receptors in diagnostic subtypes of schizophrenic patients

Infantile Mediterranean visceral leishmaniasis (IVL) and anthroponotic cutaneous leishmaniasis (ACL) have long been known to exist in the western and southeastern Turkey, respectively. To further study these and other related diseases, a recombinant antigen (rK39) specific to VL was used in an ELISA for serodiagnosis of selected patients and for screening dog reservoir populations in several endemic sites. Among 24 confirmed VL cases from western Turkey, the rK39 ELISA proved to be more sensitive than a combination of cultivation and microscopy of bone marrow aspirates. The specificity of rK39 for leishmaniasis was demonstrated by its lack of cross-reactivity with sera from other human diseases in the same sites. Interestingly, six of the 83 parasitologically proven ACL cases from southeast Turkey were also rK39 positive. The end point titers of the positive VL and CL cases vary from 10(-2) to 10(-5) and from 10(-2) to 10(-3), respectively. The rK39 ELISA was also used to screen 494 apparently healthy dogs from Urfa in southeast Turkey, Manisa/Alasehir near the Aegean Sea, and Karabuk near the Black Sea. Eighteen rK39-positive cases (3.6%), all from the latter two areas, were found to have varying endpoint titers (10(-2)-10(-4)). The high titers predicted increased severity and frequency of the clinical symptoms (i.e., lymphadenopathy, depilation, skin lesion, weight loss and/or death), which were manifested subsequently in 16 of these 18 cases. In addition, more positive canine cases were diagnosed by the rK39 ELISA preclinically than the procedures to detect parasites postsymptomatically in the lymph node aspirates. The use of the rK39 ELISA as a sensitive tool makes it possible to demonstrate coendemicity of canine and human VL, as expected in the case of IVL. The results also point to the possible presence of additional VL types in western Turkey and cutanovisceral type in the southeast part of this country.     

A method for evaluating dynamic functional network connectivity and task-modulation: application to schizophrenia

Objective

In this paper, we develop a dynamic functional network connectivity (FNC) analysis approach using correlations between windowed time-courses of different brain networks (components) estimated via spatial independent component analysis (sICA). We apply the developed method to fMRI data to evaluate it and to study task-modulation of functional connections.

Materials and methods

We study the theoretical basis of the approach, perform a simulation analysis and apply it to fMRI data from schizophrenia patients (SP) and healthy controls (HC). Analyses on the fMRI data include: (a) group sICA to determine regions of significant task-related activity, (b) static and dynamic FNC analysis among these networks by using maximal lagged-correlation and time–frequency analysis, and (c) HC–SP group differences in functional network connections and in task-modulation of these connections.

Results

This new approach enables an assessment of task-modulation of connectivity and identifies meaningful inter-component linkages and differences between the two study groups during performance of an auditory oddball task (AOT). The static FNC results revealed that connectivities involving medial visual–frontal, medial temporal–medial visual, parietal–medial temporal, parietal–medial visual and medial temporal–anterior temporal were significantly greater in HC, whereas only the right lateral fronto-parietal (RLFP)–orbitofrontal connection was significantly greater in SP. The dynamic FNC revealed that task-modulation of motor–frontal, RLFP–medial temporal and posterior default mode (pDM)–parietal connections were significantly greater in SP, and task modulation of orbitofrontal–pDM and medial temporal–frontal connections were significantly greater in HC (all P < 0.05).

Conclusion

The task-modulation of dynamic FNC provided findings and differences between the two groups that are consistent with the existing hypothesis that schizophrenia patients show less segregated motor, sensory, cognitive functions and less segregated default mode network activity when engaged with a task. Dynamic FNC, based on sICA, provided additional results which are different than, but complementary to, those of static FNC. For example, it revealed dynamic changes in default mode network connectivities with other regions which were significantly different in schizophrenia in terms of task-modulation, findings which were not possible to discover by static FNC.     

A new approach to analyzing residence time and mixing in a co-rotating twin screw extruder

A series of experiments was conducted to determine what correlations exist between an experimental parameter, percent drag flow, and other parameters such as head, tail and mean residence time. Experimentation was carried out on two polymer systems, a model system of near-Newtonian fluid and a viscoelastic system of polyisoprene with several additives. To aid in the residence time analysis, data from three literature sources were cited and replotted. A family of residence time curves for a partially filled system can be combined into one curve by plotting the number of screw revolutions carrying the tracer to the extruder exit versus the percent drag flow. This method of plotting the data for each screw configuration estimates the mean residence time for any throughput and screw speed once a few data points are taken. In all four sets of experiments, the number of screw revolutions carrying the tracer to the exit decreases with increasing percent drag flow. The filled volume of the extruder was calculated from residence time data to show that percent drag flow is linearly related to extruder filled volume. When percent drag flow increased in the viscoelastic system the following results were recorded: fraction of polymer residence time spent in conveying elements increased, fraction of residence time spent in mixing elements decreased, polymer Mooney viscosity increased, number and weight average molecular weights increased and polydispersivity increased.