For behaviour to be purposeful, it is important to monitor the preceding behavioural context, particularly for factors regarding stimulus, response and outcome. The dorsolateral prefrontal cortex ...(DLPFC) appears to play a major role in such a context-dependent, flexible behavioural control system, and this area is likely to have a neuronal mechanism for such retrospective coding, which associates response-outcome with the information and/or neural systems that guided the response. To address this hypothesis, we recorded neuronal activity from the DLPFC of monkeys performing memory- and sensory-guided saccade tasks, each of which had two conditions with reward contingencies. We found that post-response activity of a subset of DLPFC neurons was modulated by three factors relating to earlier events: the direction of the immediately preceding response, its outcome (reward or non-reward) and the information type (memory or sensory) that guided the response. Such neuronal coding should play a role in associating response-outcome with information and/or neural systems used to guide behaviour — that is, ‘retrospective monitoring’ of behavioural context and/or neural systems used for guiding behaviour — thereby contributing to context-dependent, flexible control of behaviours.
Radical addition of aldehydes and masked aldehydes like 1,3-dioxolanes to electron-deficient alkenes was achieved by the use of catalytic amounts of BPO and
N-hydroxyphthalimide (NHPI) as a ...polarity-reversal catalyst under mild conditions. Three-component radical coupling of 1,3-dioxolanes, maleates, and alkenes was performed in the presence of BPO and NHPI under similar conditions.
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Discrete integrable systems are closely related to orthogonal polynomials and
isospectral matrix transformations. In this paper, we use these relationships
to propose a nonautonomous ...time-discretization of the Camassa-Holm (CH) peakon
equation, which describes the motion of peakon waves, which are soliton waves
with sharp peaks. We then validate our time-discretization, and clarify its
asymptotic behavior as the discrete-time goes to infinity. We present numerical
examples to demonstrate that the proposed discrete equation captures peakon
wave motions.
Several lines of evidence have postulated that reduction in the activity of lipoprotein lipase (LPL) is involved in cachexia induction in cancer patients. Recently we have demonstrated that murine ...melanoma B16 has the ability to reduce the LPL activity and thereby induce cachexia symptoms in mice following intraperitoneal inoculation. In order to further investigate the relationship between LPL activity and cachectic syndrome, cachexia models other than melanoma B16 are required. However, there are few animal cachexia models in which LPL activity is involved in the induction of cachectic symptoms. In this study, cachectic symptoms and plasma LPL activity were investigated in mice bearing EL-4 mouse lymphoma. In EL-4 bearing mice the body weight including tumor weight in the abdominal cavity was rather higher than that of normal mice without tumor, whereas weights of carcass wet and gastrocnemius muscle were significantly decreased in EL-4 bearing mice. Elevated blood levels of triglyceride and non-esterified fatty acid were observed in mice bearing EL-4, associated with the impaired plasma LPL activity. Overall, this study indicated that EL-4 lymphoma in mice results in a severe cachexia which is possibly related to impaired LPL activity and also provided a useful cachexia model for understanding the role of LPL in the development of cancer cachexia.
The dorsolateral prefrontal cortex (DLPFC) is involved in visuospatial short‐term (or working) memory. Its cellular basis has been widely examined using the delayed‐response paradigm in nonhuman ...primates. Sustained delay‐period activity in DLPFC neurons with directional difference (i.e. directional delay‐period activity) has been thought to represent visuospatial short‐term (or working) memory. However, little is known about the activity of these neurons during a delay period when the sensory input remains. To address this issue, we examined neuronal activity in the DLPFC while macaque monkeys performed a memory‐guided saccade (MGS) task and a delayed visually guided saccade (VGS) task. The MGS task required a memory‐guided saccade for a remembered target location. The VGS task had the same temporal sequence as the MGS task, but the sensory stimulus remained during the delay period. We found that most of the DLPFC neurons with directional delay‐period activity showed sustained activation during the ‘delay’ period in the VGS task only (‘V‐neurons’, 49%), or in both tasks (‘MV‐neurons’, 46%). Neurons showing directional delay‐period activity in the MGS task only (‘M‐neurons’) were only 5% of the DLPFC neurons with directional delay‐period activity. These findings indicate that most DLPFC neurons that are active during the delay period are also active when the sensory stimulus remains, suggesting that DLPFC neurons driven by mnemonic information are also driven by sensory input. Such sustained representation of information should have potential utility in flexible cognitive controls of behaviour.
A newly developed non-invasive monitor, NICO (Novametrix Medical Systems Inc.), measures cardiac output based on changes in respiratory CO2 concentration caused by a brief period of rebreathing. By ...applying modified form of the CO2 Fick principle, cardiac output is calculated. We determined the accuracy and precision of this technique (RBCO) by comparing it with continuous thermodilution technique (TDCCO) and pulse dye densitometry technique (PDD). The overall difference between RBCO and TDCCO(n = 46) was -0.21 +/- 1.43 (bias +/- 2 SD)l.min-1. On the other hand, the overall difference between RBCO and PDD (n = 53) was -0.1 +/- 2.04 (bias +/- 2 SD)l.min-1. The degree of accuracy of RBCO was thought to be the same as those of TDCCO and PDD. We expect that NICO will be a useful cardiac output monitor in any method of general anesthesia in which PA catheterization is difficult or not indicated.
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