Deep analysis of perception through dynamic structures that emerge in cortical activity from self-regulated noise

The statistical properties of the spontaneous background electrocorticogram (ECoG) were modeled, starting with random numbers, constraining the distributions, and identifying characteristic deviations from randomness in ECoG from subjects at rest and during intentional behaviors. The ECoG had been recorded through 8 × 8 arrays of 64 electrodes, from the surfaces of auditory, visual, or somatic cortices of 9 rabbits, and from the inferotemporal cortex of a human subject. Power spectral densities (PSD) in coordinates of log10 power versus log10 frequency of ECoG from subjects at rest usually conformed to noise in power-law distributions in a continuum. PSD of ECoG from active subjects usually deviated from noise in having peaks in log10 power above the power-law line in various frequency bands. The analytic signals from the Hilbert transform after band pass filtering in the beta and gamma ranges revealed beats from interference among distributed frequencies in band pass filtered noise called Rayleigh noise. The beats were displayed as repetitive down spikes in log10 analytic power. Repetition rates were proportional to filter bandwidths for all center frequencies. Resting ECoG often gave histograms of the magnitudes and intervals of down spikes that conformed to noise. Histograms from active ECoG often deviated from noise in Rayleigh distributions of down spike intervals by giving what are called Rice (Mathematical analysis of random noise—and appendixes—technical publications monograph B-1589. Bell Telephone Labs Inc., New York, 1950) distributions. Adding power to noise as signals at single frequencies simulated those deviations. The beats in dynamic theory are deemed essential for perception, by gating beta and gamma bursts at theta rates through enhancement of the cortical signal-to-noise ratio in exceptionally deep down spikes called null spikes

Mucosal atrophy in collagenous colitis: a case report

<p>Abstract</p> <p>Background</p> <p>Mucosal atrophy as a potential cause of impaired colonic compliance has not yet been described as a complication in Collagenous Colitis (CC).</p> <p>Case presentation</p> <p>We present a 51-year-old female patient with a 20-year history of diarrhea and diagnosed with CC ten years prior to her presentation. We reviewed reports from three colonoscopies performed after the diagnosis. Overall 12 biopsies obtained in the last two colonoscopies were re-analyzed by two pathologists blinded to the aim of the study. Besides the typical histological findings of CC, the endoscopic appearance was normal, and no histological signs of atrophy were found during the first colonoscopy. Surprisingly, the second and third colonoscopy revealed a region of advanced segmental mucosal atrophy in the cecum with the mucosal height normalizing toward the transverse colon. This pattern of atrophy was inversely related to the pattern of sub-epithelial collagen deposition, which increased toward the rectum.</p> <p>Conclusion</p> <p>If no chance occurrence, our observation supports the idea that additional factors, probably luminal in nature, may be co-responsible for the mucosal atrophy in this case. Thus, mucosal atrophy in the proximal colon appears to be a new candidate among the growing list of rare complications associated with long standing CC.</p

Eyeblink conditioning in the infant rat: an animal model of learning in developmental neurotoxicology.

Classical conditioning of the eyeblink reflex is a relatively simple procedure for studying associative learning that was first developed for use with human subjects more than half a century ago. The use of this procedure in laboratory animals by psychologists and neuroscientists over the past 30 years has produced a powerful animal model for studying the behavioral and biological mechanisms of learning. As a result, eyeblink conditioning is beginning to be pursued as a very promising model for predicting and understanding human learning and memory disorders. Among the many advantages of this procedure are (a) the fact that it can be carried out in the same manner in both humans and laboratory animals; (b) the many ways in which it permits one to characterize changes in learning at the behavioral level; (c) the readiness with which hypotheses regarding the neurological basis of behavioral disorders can be formulated and tested; (d) the fact that it can be used in the same way across the life-span; and (e) its ability to distinguish, from normative groups, populations suffering from neurological conditions associated with impaired learning and memory, including those produced by exposure to neurotoxicants. In this article, we argue that these properties of eyeblink conditioning make it an excellent model system for studying early impairments of learning and memory in developmental neurotoxicology. We also review progress that has been made in our laboratory in developing a rodent model of infant eyeblink conditioning for this purpose

Foot kinematics in patients with two patterns of pathological plantar hyperkeratosis

Background: The Root paradigm of foot function continues to underpin the majority of clinical foot biomechanics practice and foot orthotic therapy. There are great number of assumptions in this popular paradigm, most of which have not been thoroughly tested. One component supposes that patterns of plantar pressure and associated hyperkeratosis lesions should be associated with distinct rearfoot, mid foot, first metatarsal and hallux kinematic patterns. Our aim was to investigate the extent to which this was true. Methods: Twenty-seven subjects with planter pathological hyperkeratosis were recruited into one of two groups. Group 1 displayed pathological plantar hyperkeratosis only under metatarsal heads 2, 3 and 4 (n = 14). Group 2 displayed pathological plantar hyperkeratosis only under the 1st and 5th metatarsal heads (n = 13). Foot kinematics were measured using reflective markers on the leg, heel, midfoot, first metatarsal and hallux. Results: The kinematic data failed to identify distinct differences between these two groups of subjects, however there were several subtle (generally <3°) differences in kinematic data between these groups. Group 1 displayed a less everted heel, a less abducted heel and a more plantarflexed heel compared to group 2, which is contrary to the Root paradigm. Conclusions: There was some evidence of small differences between planter pathological hyperkeratosis groups. Nevertheless, there was too much similarity between the kinematic data displayed in each group to classify them as distinct foot types as the current clinical paradigm proposes

The relationship between physiological and perceived fall risk in people with multiple sclerosis: implications for assessment and management

Objective: This study evaluated the relationship between physiological and perceived fall risk in people with multiple sclerosis (MS). Design: Secondary analysis of data from prospective cohort studies undertaken in Australia, the United Kingdom, and the United States. Setting: Community. Participants: Ambulatory people with MS (N=416) (age 51.5±12.0 years; 73% female; 62% relapsing-remitting MS; 13.7±9.9 years disease duration). Interventions: Not applicable. Main Outcome Measures: All participants completed measures of physiological (Physiological Profile Assessment [PPA]) and perceived (Falls Efficacy Scale-international [FESi]) fall risk and prospectively recorded falls for 3 months. Results: 155 (37%) of the participants were recurrent fallers (≥2 falls). Mean PPA and FESi scores were high (PPA 2.14±1.87, FESi 34.27±11.18). The PPA and the FESi independently predicted faller classification in logistic regression, which indicated that the odds of being classified as a recurrent faller significantly increased with increasing scores (PPA odds ratio [OR] 1.30 [95% CI 1.17-1.46], FESi OR 1.05 [95% CI 1.03-1.07]). Classification and regression tree analysis divided the sample into four groups based on cutoff values for the PPA: (1) low physiological/low perceived risk (PPA 27.5), (3) high physiological/low perceived risk (PPA >2.83, FESi 35.5). Over 50% of participants had a disparity between perceived and physiological fall risk; most were in group 2. It is possible that physiological risk factors not detected by the PPA may also be influential. Conclusions: This study highlights the importance of considering both physiological and perceived fall risk in MS and the need for further research to explore the complex interrelationships of perceptual and physiological risk factors in this population. This study also supports the importance of developing behavioral and physical interventions that can be tailored to the individual's needs

Increasing prevalence and high incidence of celiac disease in elderly people: A population-based study

<p>Abstract</p> <p>Background</p> <p>Celiac disease may emerge at any age, but little is known of its appearance in elderly people. We evaluated the prevalence of the condition in individuals over 55 years of age, and determined the incidence of biopsy-proven celiac disease (CDb) and celiac disease including seropositive subjects for anti-tissue transglutaminase antibodies (CDb+s).</p> <p>Methods</p> <p>The study based on prevalence figures in 2815 randomly selected subjects who had undergone a clinical examination and serologic screening for celiac disease in 2002. A second screening in the same population was carried out in 2005, comprising now 2216 individuals. Positive tissue transglutaminase antibodies were confirmed with small bowel biopsy.</p> <p>Results</p> <p>Within three years the prevalence of CDb increased from 2.13 to 2.34%, and that of CDb+s from 2.45 to 2.70%. Five new cases were found among patients previously seronegative; two had minor abdominal symptoms and three were asymptomatic. The incidence of celiac disease in 2002–2005 was 0.23%, giving an annual incidence of 0.08% in this population.</p> <p>Conclusion</p> <p>The prevalence of celiac disease was high in elderly people, but the symptoms were subtle. Repeated screening detected five biopsy-proven cases in three years, indicating that the disorder may develop even in the elderly. Increased alertness to the disorder is therefore warranted.</p

Perforated Meckel's diverticulitis complicating active Crohn's ileitis: a case report

<p>Abstract</p> <p>Introduction</p> <p>In Crohn's disease, the extension of active terminal ileitis into a Meckel's diverticulum is possible, but usually has no impact on clinical decision-making. We describe an original surgical approach in a young woman presenting with a combination of perforated Meckel's diverticulitis and active Crohn's ileitis.</p> <p>Case presentation</p> <p>We report the case of a 22-year-old woman with Crohn's disease, who was admitted for abdominal pain, fever and diarrhoea. CT scan demonstrated active inflammation of the terminal ileum, as well as a fluid collection in the right iliac fossa, suggesting intestinal perforation. Laparoscopy was performed and revealed, in addition to extensive ileitis, a 3 × 3 cm abscess in connection with perforated Meckel's diverticulitis. It was therefore possible to avoid ileocaecal resection by only performing Meckel's diverticulectomy; pathological examination of the surgical specimen revealed the presence of transmural inflammation with granulomas and perforation of the diverticulum at its extremity.</p> <p>Conclusion</p> <p>Crohn's disease of the ileum may be responsible for Meckel's diverticulitis and cause perforation which, in this case, proved to be a blessing in disguise and spared the patient an extensive small bowel resection.</p

Sources of scientific creativity: participant observation of a public research institute in Korea

This study aims to find the factors of scientists' creative thoughts by observing directly their laboratories in Korea Research Institute of Chemical Technology (KRICT). The participant observation was performed for 5 months from December 2013 through April 2014, and the research object was the lab which had been selected both as Top KRICT laboratory and Top National R&D Project. For in-depth examination, the target lab was supposed to be observed for a long time, taking part in the lab meetings, interviewing the researchers. From the interview data, Protocol analysis or Verbal data analysis was employed to analyze the recorded data. The research results are as follows. First, as several studies had suggested, the frequent use of analogies was verified as an important source for scientists' creative thoughts, in that those analogies were used for 12 times in 2 lab meetings, which was 6 times per each. Secondly, the frequent appearance of unexpected findings was found, that is, 8 out of 15 experiment findings were unexpected. We found that the scientists pay close attention to the unexpected findings in that 67 out of 88 intra-group interactions were about the unexpected findings, and 21 out of 24 individual reasoningblocks were about the unexpected findings. Finally, we found that the seeds of new knowledge and ideas sprouted and spread through the distributed reasoning process, which is the major characteristic of modern science that is generally conducted by group of scientists. The findings have two theoretical implications. First, it may increase the availability of Ikujiro Nonaka's knowledge-creation model by adding another case study. It may also contribute to balance between supply-side and demand-side perspective of Innovation. System studies by supplementing supply-side perspective