168 research outputs found
Influence of Rat Strain and Arthritogen on Actions of Gold Drugs in Adjuvant-Induced Polyarthritis
The article examines the effects of aurothiomalate (ATM) and auranofin (AF) on adjuvant-induced polyarthritis and serum gold levels in three different strains of rats
The Influence of Prednisolone (PRED) and Methotrexate (MTX) on the Cell and Connective Tissue Content of Subcutaneously Implanted Polyurethane Sponges in Rats
Findings indicate that prednislone and methotrexate have profound effects on the cellular events of acute and chronic inflammation, and influence the synthesis or degradation of connective tissue macromolecules at certain stages of the inflammatory process
Architektury kognitywne, czyli jak zbudować sztuczny umysł
Architektury kognitywne (AK) są próbą stworzenia modeli komputerowych
integrujących wiedzę o działaniu umysłu. Ich zadaniem jest implementacja konkretnych
schematów działania funkcji poznawczych umożliwiająca testowanie tych funkcji na
szerokiej gamie zagadnień. Wiele architektur kognitywnych opracowano w celu
symulacji procesu komunikacji pomiędzy człowiekiem i złożonymi maszynami (HCI,
Human-Computer Interfaces), symulowania czasów reakcji oraz różnych
psychofizycznych zależności. Można to do pewnego stopnia osiągnąć budując modele
układu poznawczego na poziomie symbolicznym, z wiedzą w postaci reguł logicznych.
Istnieją też projekty, które próbują powiązać procesy poznawcze z aktywacją modułów
reprezentujących konkretne obszary mózgu, zgodnie z obserwacjami w eksperymentach
z funkcjonalnym rezonansem magnetycznym (fMRI). Dużą grupę stanowią architektury
oparte na podejściu logicznym, które mają na celu symulację wyższych czynności
poznawczych, przede wszystkim procesów myślenia i rozumowania. Niektóre z
projektów rozwoju architektur poznawczych skupiają większe grupy badawcze
działające od wielu dziesięcioleci.
Ogólnie architektury kognitywne podzielić można na 3 duże grupy: architektury
symboliczne (oparte na funkcjonalnym rozumieniu procesów poznawczych);
architektury emergentne, oparte na modelach koneksjonistycznych; oraz architektury
hybrydowe, wykorzystujące zarówno modele neuronowe jak i reguły symboliczne. W
ostatnich latach znacznie wzrosło zainteresowanie architekturami inspirowanymi przez
neurobiologię (BICA, Brain Inspired Cognitive Architectures). Jak sklasyfikować różne
architektury, jakie wyzwania należy przed nimi postawić, jak oceniać postępy w ich
rozwoju, czego nam brakuje do stworzenia pełnego modelu umysłu? Krytyczny przegląd
istniejących architektur kognitywnych, ich ograniczeń i możliwości pozwala na
sformułowanie ogólnych wniosków dotyczących kierunków ich rozwoju czego nam brakuje do stworzenia pełnego modelu umysłu? Krytyczny przegląd
istniejących architektur kognitywnych, ich ograniczeń i możliwości pozwala na
sformułowanie ogólnych wniosków dotyczących kierunków ich rozwoju oraz
wysunięcie własnych propozycji budowy nowej architektury
Correlations of behavioral deficits with brain pathology assessed through longitudinal MRI and histopathology in the R6/1 mouse model of huntington's disease
Huntington's disease (HD) is caused by the expansion of a CAG repeat in the huntingtin (HTT) gene. The R6 mouse models of HD express a mutant version of exon 1 HTT and typically develop motor and cognitive impairments, a widespread huntingtin (HTT) aggregate pathology and brain atrophy. Unlike the more commonly used R6/2 mouse line, R6/1 mice have fewer CAG repeats and, subsequently, a less rapid pathological decline. Compared to the R6/2 line, fewer descriptions of the progressive pathologies exhibited by R6/1 mice exist. The association between the molecular and cellular neuropathology with brain atrophy, and with the development of behavioral phenotypes remains poorly understood in many models of HD. In attempt to link these factors in the R6/1 mouse line, we have performed detailed assessments of behavior and of regional brain abnormalities determined through longitudinal, in vivo magnetic resonance imaging (MRI), as well as an end-stage, ex vivo MRI study and histological assessment. We found progressive decline in both motor and non-motor related behavioral tasks in R6/1 mice, first evident at 11 weeks of age. Regional brain volumes were generally unaffected at 9 weeks, but by 17 weeks there was significant grey matter atrophy. This age-related brain volume loss was validated using a more precise, semi-automated Tensor Based morphometry assessment. As well as these clear progressive phenotypes, mutant HTT (mHTT) protein, the hallmark of HD molecular pathology, was widely distributed throughout the R6/1 brain and was accompanied by neuronal loss. Despite these seemingly concomitant, robust pathological phenotypes, there appeared to be little correlation between the three main outcome measures: behavioral performance, MRI-detected brain atrophy and histopathology. In conclusion, R6/1 mice exhibit many features of HD, but the underlying mechanisms driving these clear behavioral disturbances and the brain volume loss, still remain unclear. © 2013 Rattray et al
The effectiveness and cost-evaluation of manual therapy and physical therapy in patients with sub-acute and chronic non specific neck pain. Rationale and design of a Randomized Controlled Trial (RCT)
Contains fulltext :
88910.pdf (publisher's version ) (Open Access)BACKGROUND: Manual Therapy applied to patients with non specific neck pain has been investigated several times. In the Netherlands, manual therapy as applied according to the Utrecht School of Manual Therapy (MTU) has not been the subject of a randomized controlled trial. MTU differs in diagnoses and treatment from other forms of manual therapy. METHODS/DESIGN: This is a single blind randomized controlled trial in patients with sub-acute and chronic non specific neck pain. Patients with neck complaints existing for two weeks (minimum) till one year (maximum) will participate in the trial. 180 participants will be recruited in thirteen primary health care centres in the Netherlands.The experimental group will be treated with MTU during a six week period. The control group will be treated with physical therapy (standard care, mainly active exercise therapy), also for a period of six weeks.Primary outcomes are Global Perceived Effect (GPE) and functional status (Neck Disability Index (NDI-DV)). Secondary outcomes are neck pain (Numeric Rating Scale (NRS)), Eurocol, costs and quality of life (SF36). DISCUSSION: This paper presents details on the rationale of MTU, design, methods and operational aspects of the trial. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00713843
Towards neuro-inspired symbolic models of cognition: linking neural dynamics to behaviors through asynchronous communications
A computational architecture modeling the relation between perception and action is proposed. Basic brain processes representing synaptic plasticity are first abstracted through asynchronous communication protocols and implemented as virtual microcircuits. These are used in turn to build mesoscale circuits embodying parallel cognitive processes. Encoding these circuits into symbolic expressions gives finally rise to neuro-inspired programs that are compiled into pseudo-code to be interpreted by a virtual machine. Quantitative evaluation measures are given by the modification of synapse weights over time. This approach is illustrated by models of simple forms of behaviors exhibiting cognition up to the third level of animal awareness. As a potential benefit, symbolic models of emergent psychological mechanisms could lead to the discovery of the learning processes involved in the development of cognition. The executable specifications of an experimental platform allowing for the reproduction of simulated experiments are given in “Appendix”
Biodistribution of 64 Cu in Inflamed Rats Following Administration of Two Anti-Inflammatory Copper Complexes
64Cu was administered in two anti-inflammatory formulations to normal rats and to rats with 2 forms of local inflammation, namely (a) an acute paw oedema (elicited with carrageenan) or (b) a chronic granulomatous response to an implanted irritant (Mycobacterium tuberculosis in a polyurethane sponge). The copper formulations used were (i) a slow release one consisting of Cu(II) salicylate applied dermally with ethanol/DMSO and (ii) short acting hydrophilic complex (Cu(I)Cu(II)-penicillamine)5- given subcutaneously. Three types of changes in copper biodistribution with these forms of inflammation were discerned based on determination of 64Cu and copper content in the following organs: inflammatory locus (foot or sponge implant), kidney, liver, spleen, adrenals, brain, blood, thymus, heart, and skin (site of application). The most evident changes were in the kidneys, liver, spleen, adrenals, thymus and serum from animals with chronic granulomatous inflammation. In contrast, a short term acute inflammatory stress (carrageenan paw oedema) had little effect. While copper D-penicillamine (applied subcutaneously) appeared to move as a bolus through the animals, the results with the percutaneous copper salicylate formulation are consistent with it providing a slow release source of copper(II). Exogenous 64Cu from both formulations was sequestered at inflammatory sites (relative to serum). This may partly explain how applied copper complexes can be anti-inflammatory
Bayesian uncertainty analysis for complex systems biology models: emulation, global parameter searches and evaluation of gene functions
- …