Effect of training on the ability of dual-task coordination

Within the framework of the working memory model proposed by A. Baddeley and G. Hitch, a dual-task paradigm has been suggested to evaluate the capacity to perform simultaneously two concurrent tasks. This capacity is assumed to reflect the functioning of the central executive component, which appears to be impaired in patients with dysexecutive syndrome. The present study extends the investigation of an index ("mu"), which is supposed to indicate the capacity of coordination of concurrent auditory digit span and tracking tasks, by testing the influence of training on the performance in the dual task. The presentation of the same digit sequence lists or always-different lists did not differently affect the performance. The span length affected the mu values. The improved performance in the tasks under the dual condition closely resembled the improvement in the single-task performance. So, although training improved performance in the single and dual conditions, especially for the tracking component, the mu values remained stable throughout the sessions when the single tasks were performed first. Conversely, training improved the capacity of dual-task coordination throughout the sessions when dual task was performed first, addressing the issue of the contribution of the within-session practice to the mu index.

Reproductive ability of pubertal male and female rats

Ten Fisher rats 50 to 55 days of age made up the pubertal group, and ten rats 90 to 95 days of age served as the controls. The testicular and epididymal weights and volumes of the pubertal males were lower than those of the controls (P<0.001). There was also a difference in relative epididymal weight (P<0.001). The sperm of pubertal males was morphologically abnormal in 58.2% of cases, as opposed to only 3.8% in the controls (P<0.001). The mean number of spermatozoa in the control group was 11.9 × 10(6)/ml and their viability was 99.6%, while these values could not be determined for pubertal rats. Serum testosterone was higher in the pubertal animals than in the controls (2.52 ± 1.46 vs 0.92 ± 0.34 nM, P<0.01). The ovaries of control females were heavier than those of pubertal females (P<0.001) but there was no difference in their relative weights. Serum estradiol was similar in both groups (75.5 ± 12.8 vs 81.8 ± 14.7 nM, P>0.05). At the beginning of gestation, the pubertal dams weighed less than the controls (P<0.001) but following uterectomy the body weights were equal. Pubertal dams delivered fewer pups than the controls (8.1 ± 2.5 vs 10.4 ± 1.3, P<0.05). There was no difference in the body weights of their offspring or in the weights of their placentas. The results suggest that, in contrast to their female counterparts, pubertal male rats are not fully mature and have not reached complete reproductive capacity at 50-55 days of age.

Novel word learning ability in chronic post-stroke aphasia : variability and modality effects

Novel word learning has been rarely studied in people with aphasia (PWA), although it can provide a relatively pure measure of their learning potential, and thereby contribute to the development of effective aphasia treatment methods. The main aim of the present thesis was to explore the capacity of PWA for associative learning of word–referent pairings and cognitive-linguistic factors related to it. More specifically, the thesis examined learning and long-term maintenance of the learned pairings, the role of lexical-semantic abilities in learning as well as acquisition of phonological versus semantic information in associative novel word learning. Furthermore, the effect of modality on associative novel word learning and the neural underpinnings of successful learning were explored. The learning experiments utilized the Ancient Farming Equipment (AFE) paradigm that employs drawings of unfamiliar referents and their unfamiliar names. Case studies of Finnishand English-speaking people with chronic aphasia (n = 6) were conducted in the investigation. The learning results of PWA were compared to those of healthy control participants, and active production of the novel words and their semantic definitions was used as learning outcome measures. PWA learned novel word–novel referent pairings, but the variation between individuals was very wide, from more modest outcomes (Studies I–II) up to levels on a par with healthy individuals (Studies III–IV). In incidental learning of semantic definitions, none of the PWA reached the performance level of the healthy control participants. Some PWA maintained part of the learning outcomes up to months post-training, and one individual showed full maintenance of the novel words at six months post-training (Study IV). Intact lexical-semantic processing skills promoted learning in PWA (Studies I–II) but poor phonological short-term memory capacities did not rule out novel word learning. In two PWA with successful learning and long-term maintenance of novel word–novel referent pairings, learning relied on orthographic input while auditory input led to significantly inferior learning outcomes (Studies III–IV). In one of these individuals, this previously undetected modalityspecific learning ability was successfully translated into training with familiar but inaccessible everyday words (Study IV). Functional magnetic resonance imaging revealed that this individual had a disconnected dorsal speech processing pathway in the left hemisphere, but a right-hemispheric neural network mediated successful novel word learning via reading. Finally, the results of Study III suggested that the cognitive-linguistic profile may not always predict the optimal learning channel for an individual with aphasia. Small-scale learning probes seem therefore useful in revealing functional learning channels in post-stroke aphasia.

Human monocytes tolerant to LPS retain the ability to phagocytose bacteria and generate reactive oxygen species

Tolerance to lipopolysaccharide (LPS) occurs when animals or cells exposed to LPS become hyporesponsive to a subsequent challenge with LPS. This mechanism is believed to be involved in the down-regulation of cellular responses observed in septic patients. The aim of this investigation was to evaluate LPS-induced monocyte tolerance of healthy volunteers using whole blood. The detection of intracellular IL-6, bacterial phagocytosis and reactive oxygen species (ROS) was determined by flow cytometry, using anti-IL-6-PE, heat-killed Staphylococcus aureus stained with propidium iodide and 2',7'-dichlorofluorescein diacetate, respectively. Monocytes were gated in whole blood by combining FSC and SSC parameters and CD14-positive staining. The exposure to increasing LPS concentrations resulted in lower intracellular concentration of IL-6 in monocytes after challenge. A similar effect was observed with challenge with MALP-2 (a Toll-like receptor (TLR)2/6 agonist) and killed Pseudomonas aeruginosa and S. aureus, but not with flagellin (a TLR5 agonist). LPS conditioning with 15 ng/mL resulted in a 40% reduction of IL-6 in monocytes. In contrast, phagocytosis of P. aeruginosa and S. aureus and induced ROS generation were preserved or increased in tolerant cells. The phenomenon of tolerance involves a complex regulation in which the production of IL-6 was diminished, whereas the bacterial phagocytosis and production of ROS was preserved. Decreased production of proinflammatory cytokines and preserved or increased production of ROS may be an adaptation to control the deleterious effects of inflammation while preserving antimicrobial activity.

Stability and predictive ability of beta

The purpose of this paper is to examine the stability and predictive abilities of the beta coefficients of individual equities in the Finnish stock market. As beta is widely used in several areas of finance, including risk management, asset pricing and performance evaluation among others, it is important to understand its characteristics and find out whether its estimates can be trusted and utilized.

Rheology of spreadable goat cheese made with autochthonous lactic cultures differing in their ability to produce exopolysaccharides

The aim of this study was to compare the rheology of spreadable cheeses elaborated with autochthonous lactic starter cultures without the addition of exopolysaccharide-producing strain in the same starter with exopolysaccharide-producing strain. From a rheological standpoint, both samples were characterized as weak viscoelastic gels and pseudoplastic products. It was concluded that cheese made with exopolysaccharide-producing strain showed smaller G', G", and η* values over the range of frequencies studied and smaller critic stress values than the cheese without exopolysaccharide-producing strain. The results obtained indicate that cheeses without exopolysaccharide-producing strain need to be added with any texture enhancer product.

Ability of a Lactobacillus rhamnosus strain cultured in milk whey based medium to bind aflatoxin B1

This study aimed to compare Lactobacillus rhamnosus growth in MRS (de Man, Rogosa and Sharpe) broth and a culture medium containing milk whey (MMW) and to evaluate aflatoxin B1 (AFB1) adsorption capacity by bacterial cells produced in both culture media. L. rhamnosus cells were cultivated in MRS broth and MMW (37 °C, 24 hours), and bacterial cell concentration was determined spectrophotometrically at 600 nm. AFB1 (1 µg/ml) adsorption assays were conducted using 1 x 10(10) non-viable L. rhamnosus cells (121 °C, 15 minutes) at pHs 3.0 and 6.0 and contact time of 60 minutes. AFB1 quantification was performed by High Performance Liquid Chromatography. Bacterial cell concentration in MMW was higher (9.84 log CFU/ml) than that in MRS broth (9.63 log CFU/ml). There were no significant differences between AFB1 binding results at the same pH value (3.0 or 6.0) for the cells cultivated in MRS broth (46.0% and 35.8%, respectively) and in MMW (43.7% and 25.8%, respectively), showing that MMW can adequately replace the MRS broth. Therefore, it can be concluded that the use of L. rhamnosus cells cultivated in MMW offers advantages such as reduction in large scale production costs, improvement of environmental sustainability, and being a practicable alternative for decontamination of food products susceptible to aflatoxin contamination.

Lean Product Management – Enhancing Product Managers' Ability to Create Value

The purpose of this master’s thesis was to study the opportunity to apply Lean practices to product management function which happens in an office environment. Since product management plays an important role in the company’s success story, it’s important to have it functioning as effectively as possible. The goal was to find those Lean tools and methods that fit the best to the needs of product management. The research was conducted as a qualitative action research which comprises a comprehensive literature review and a single case study. Theoretical information about Lean Thinking and product management was collected from articles, literature and Internet sources. Moreover, empirical data was collected by conducting interviews in the Case Company’s product management department in order to gain an in-depth understanding of product management’s problematics. The results indicate that most of the product management challenges could be overcome by applying Lean practises. Based on the usability rate, which has been discussed in the empirical part of this study, the most suitable Lean practises for product management function are: value stream mapping, Kanban and KPIs.

Is there a difference in artistic ability between learning -disabled students and "regular-class" students?

Research and practice regarding LO students usually has focussed upon defining and supplementing deficiencies rather than seeking unique talents and capability patterns for learning and expression. This study examined nine dimensions that may constitute artistic or creative talent and compared LDs with "regular-class" students, pair-wise and as groups, for levels and distributions of the dimensions. For 14 LO and 9 "regular-class" elementary-school subjects, both genders, data were taken by direct observation, from a standardized test and assessments by two practicing artists. Assessments by artists were in concord. LOs improved more in "Composition". No other significant class, age or gender-related differences were found.

The effectiveness of a multisensory writing program in improving cursive writing ability in children with sensorimotor difficulties

It is estimated that five to ten percent of children experience sensory motor difficulties that result in various learnlng disabilitiies , among them. inabllity to output Information on paper in the appropriate manner (Ayres ,1985). The relationship between sensorimotorabillty and handwriting is well documented in the literature (Freeman,1917; Townsend , 1951; Nlkola-Ll sa, 1987). While much of the literature is inconclusive, there are findings to suggest that muitisensory handwriting programmes are an effective approach to improvlng writing abIlity in these chlldren. For a number of years, Occupational Therapists have been involved in the remediation of handwriting utllizing , amongst other approaches . multisensory programmes. While subjective assessments of effectiveness have been extremerly positive. scientIfic evaluation has been minimal . If further intervention in this area is to occur, it Is essential that the profession be able to justify the existence of such programmes . The purpose of this study was to examine what effects a multlsensory writing prog~am would have on the curslve writing ability of chlldren with sensorimotor dlfficulties. A single case with multiple baselines across be havlours design was used , with the behavlours being cursive writing abilIty of fIve distInct letter groups. The fIve groups were taught in random order, one group every two weeks , In a one-hour session. Repeated measurements of writing speed and qualIty for each letter group were made. This design was repeated over three other cases . Results of the study yielded statistical signifi cance in trend changes In specIfic letter groups for all of the chlldren following interventlon. One child achieved statistical significance In the overall change In quality , while none of the children achieved overall statistical significance In speed score changes . Teacher reports and an assessment of written language prior to and following the program suggest that Intervention may have had a positive effect on self-confidence in written output, and on the maturlty of written expression in some of the cases . Further research in this field is needed to validate the continual use of multisensory writing programmes by Occupational Theraplsts worklng with this specific population and to provide some directlon with regards to the Integration of multlsensory writing programmes within the regular academic remedial programme .

The effects of teaching a mathematics problem solving strategy on the problem solving ability of grade nine students

Forty grade 9 students were selected from a small rural board in southern Ontario. The students were in two classes and were treated as two groups. The treatment group received instruction in the Logical Numerical Problem Solving Strategy every day for 37 minutes over a 6 week period. The control group received instruction in problem solving without this strategy over the same time period. Then the control group received the treat~ent and the treatment group received the instruction without the strategy. Quite a large variance was found in the problem solving ability of students in grade 9. It was also found that the growth of the problem solving ability achievement of students could be measured using growth strands based upon the results of the pilot study. The analysis of the results of the study using t-tests and a MANOVA demonstrated that the teaching of the strategy did not significaritly (at p s 0.05) increase the problem solving achievement of the students. However, there was an encouraging trend seen in the data.

Verbal ability, previous practice and load on short-term memory as determiners of differences in a complex learning task: an experimental study

Traditional psychometric theory and practice classify people according to broad ability dimensions but do not examine how these mental processes occur. Hunt and Lansman (1975) proposed a 'distributed memory' model of cognitive processes with emphasis on how to describe individual differences based on the assumption that each individual possesses the same components. It is in the quality of these components ~hat individual differences arise. Carroll (1974) expands Hunt's model to include a production system (after Newell and Simon, 1973) and a response system. He developed a framework of factor analytic (FA) factors for : the purpose of describing how individual differences may arise from them. This scheme is to be used in the analysis of psychometric tes ts . Recent advances in the field of information processing are examined and include. 1) Hunt's development of differences between subjects designated as high or low verbal , 2) Miller's pursuit of the magic number seven, plus or minus two, 3) Ferguson's examination of transfer and abilities and, 4) Brown's discoveries concerning strategy teaching and retardates . In order to examine possible sources of individual differences arising from cognitive tasks, traditional psychometric tests were searched for a suitable perceptual task which could be varied slightly and administered to gauge learning effects produced by controlling independent variables. It also had to be suitable for analysis using Carroll's f ramework . The Coding Task (a symbol substitution test) found i n the Performance Scale of the WISe was chosen. Two experiments were devised to test the following hypotheses. 1) High verbals should be able to complete significantly more items on the Symbol Substitution Task than low verbals (Hunt, Lansman, 1975). 2) Having previous practice on a task, where strategies involved in the task may be identified, increases the amount of output on a similar task (Carroll, 1974). J) There should be a sUbstantial decrease in the amount of output as the load on STM is increased (Miller, 1956) . 4) Repeated measures should produce an increase in output over trials and where individual differences in previously acquired abilities are involved, these should differentiate individuals over trials (Ferguson, 1956). S) Teaching slow learners a rehearsal strategy would improve their learning such that their learning would resemble that of normals on the ,:same task. (Brown, 1974). In the first experiment 60 subjects were d.ivided·into high and low verbal, further divided randomly into a practice group and nonpractice group. Five subjects in each group were assigned randomly to work on a five, seven and nine digit code throughout the experiment. The practice group was given three trials of two minutes each on the practice code (designed to eliminate transfer effects due to symbol similarity) and then three trials of two minutes each on the actual SST task . The nonpractice group was given three trials of two minutes each on the same actual SST task . Results were analyzed using a four-way analysis of variance . In the second experiment 18 slow learners were divided randomly into two groups. one group receiving a planned strategy practioe, the other receiving random practice. Both groups worked on the actual code to be used later in the actual task. Within each group subjects were randomly assigned to work on a five, seven or nine digit code throughout. Both practice and actual tests consisted on three trials of two minutes each. Results were analyzed using a three-way analysis of variance . It was found in t he first experiment that 1) high or low verbal ability by itself did not produce significantly different results. However, when in interaction with the other independent variables, a difference in performance was noted . 2) The previous practice variable was significant over all segments of the experiment. Those who received previo.us practice were able to score significantly higher than those without it. J) Increasing the size of the load on STM severely restricts performance. 4) The effect of repeated trials proved to be beneficial. Generally, gains were made on each successive trial within each group. S) In the second experiment, slow learners who were allowed to practice randomly performed better on the actual task than subjeots who were taught the code by means of a planned strategy. Upon analysis using the Carroll scheme, individual differences were noted in the ability to develop strategies of storing, searching and retrieving items from STM, and in adopting necessary rehearsals for retention in STM. While these strategies may benef it some it was found that for others they may be harmful . Temporal aspects and perceptual speed were also found to be sources of variance within individuals . Generally it was found that the largest single factor i nfluencing learning on this task was the repeated measures . What e~ables gains to be made, varies with individuals . There are environmental factors, specific abilities, strategy development, previous learning, amount of load on STM , perceptual and temporal parameters which influence learning and these have serious implications for educational programs .

Comparison of classification ability of hyperball algorithms to neural network and k-nearest neighbour algorithms

The main focus of this thesis is to evaluate and compare Hyperbalilearning algorithm (HBL) to other learning algorithms. In this work HBL is compared to feed forward artificial neural networks using back propagation learning, K-nearest neighbor and 103 algorithms. In order to evaluate the similarity of these algorithms, we carried out three experiments using nine benchmark data sets from UCI machine learning repository. The first experiment compares HBL to other algorithms when sample size of dataset is changing. The second experiment compares HBL to other algorithms when dimensionality of data changes. The last experiment compares HBL to other algorithms according to the level of agreement to data target values. Our observations in general showed, considering classification accuracy as a measure, HBL is performing as good as most ANn variants. Additionally, we also deduced that HBL.:s classification accuracy outperforms 103's and K-nearest neighbour's for the selected data sets.