Research and investigative analysis using Kron's method of analyzing redundant structures

Response characteristics, frequency, and mode shape of Saturn SA-DI vehicle - analysis of redundant structure

Tactile experience induces c-fos expression in rat barrel cortex

Understanding gene expression that is responsive to sensory stimulation is central to elucidate molecular mechanisms underlying neuronal plasticity. In this study we demonstrate two new methods of stimulating whiskers that provide major sensory input to rat neocortex. In the first paradigm, animals were placed on the top of a cylinder and their vibrissae were brushed by hand, In the second paradigm, animals were placed for a brief period or time into a new, wired cage resulting in vibrissae stimulation when they explored the new environment. Both approaches induced c-Fos expression in barrel cortex corresponding to the stimulated vibrissae, especially in layer IV. Layers II/III and V/VI also showed c-Fos induction, but there were no detectable changes in layer VIb. The majority of c-Fos-expressing cells are probably not inhibitory neurons, because they do not show parvalbumin staining. Both paradigms, in contrast to the previous methods, are simple to use and do not require anesthesia, restraint of animals, or elaborate experimental setups

Forensic Engineering of Advanced Polymeric Materials. Part 1 –Degradation Studies of Polylactide Blends with Atactic Poly[(R,S)-3-hydroxybutyrate] in Paraffin

The degradation of the advanced polymeric materials: blends of polylactide with poly[(R,S)-3-hydroxybutyrate] was studied in paraffin (an ingredient used in cosmetics) and compared with the degradation of pure poly[(R,S)-3-hydroxybutyrate]. The interaction between the polymeric materials studied and the paraffin was monitored during the degradation experiments, and the effects of this interaction were reported. Gel permeation chromatography, atomic force microscopy, electrospray mass spectrometry, nuclear magnetic resonance, differential scanning calorimetry and thermal gravimetric analysis revealed that degradation of the investigated materials occurs in the presence of paraffin. In the blends, poly[(R,S)-3-hydroxybutyrate] content was found to extend the disintegration time, and for the blends with good miscibility, reduced the degradation rate in the first step of degradation

Examination of the cut-off scores determined by the Ages and Stages Questionnaire in a population-based sample of 6 month-old Norwegian infants

<p>Abstract</p> <p>Background</p> <p>Few population-based samples have previously published performance on the Ages and Stages Questionnaire (ASQ), a recommended screening tool to detect infant developmental delay. The aim of the study was to investigate performance on the ASQ in a population-based sample of 6-month-old infants.</p> <p>Methods</p> <p>In this population-based questionnaire study from Oslo, Norway, the 30 item ASQ 6 month Questionnaire (N = 1053) were included, however without the pictograms, and compared to the Norwegian reference sample (N.ref) (N = 169) and to US cut-off values. Exclusion criteria were maternal non-Scandinavian ethnicity, infant age < 5.0 or > 7.0 months (corrected age), twins, and birth weight < 2.5 kg. Cut-off = 2.5 percentile (equivalent to mean minus 2 standard deviations). Pearson's Chi square and Mann-Whitney U were used to compare items and areas, respectively, with N.ref.</p> <p>Results</p> <p>The reported ASQ scores were lower on all but one of the 10 significantly different items, and in all areas except Personal social, compared to the N.ref sample. The estimated cut-off values for suspected developmental delay (Communication 25, Gross motor 15, Fine motor 18, Problem solving 25 and Personal social 20) were lower than the recommended American (US) values in all areas, and lower than the Norwegian values in two areas. Scores indicating need for further assessment were reached by 13.8% or 20.5% of the infants (missing items scored according to the US or the Norwegian manual), and by 33.8% or 30.3% of the infants using the recommended US or the Norwegian cut-off values, in this population-based sample. The Fine motor area demonstrated a large variability depending on the different cut-off and scoring possibilities. Both among the items excluding pictograms and the items that do not have pictograms, approximately every third item differed significantly compared to the N.ref sample.</p> <p>Conclusion</p> <p>The psychomotor developmental scores were lower than in the reference samples in this study of ASQ 6 month Questionnaire; to our knowledge the first study to be both representative and comparatively large. Approximately every third child with birth weight above 2.5 kg, received scores suggesting further assessment using recommended ASQ cut-off scores.</p

Prediction studies of environment-friendly biodegradable polymeric packaging based on PLA. Influence of specimens’ thickness on the hydrolytic degradation profile

Application of new biodegradable polymer packaging based on polylactide (PLA), susceptible to organic recycling, can help in the waste reduction in landfills. In this paper, the results of the study on abiotic degradation of PLA and its blend containing 15 mol% of poly[(R,S)-3-hydroxybutyrate], as a model for the first step of organic recycling were presented. The samples used for this study have different shapes and thicknesses: rigid films and cuboid-bars. Particular emphasis was placed on determining the pattern of degradation products released into the medium. Originally, the results of present study revealed that the application of electrospray ionization mass spectrometry supported by high performance liquid chromatography allowed envisaging the differences in the degradation products pattern released from the studied PLA-based samples differing in thickness. The significant differences in degradation products pattern were predominately observed in the first steps of incubation process and are caused by an autocatalytic effect, which occurs mainly during degradation of the large size PLA samples. Although, the thickness of PLA-based packaging changes the degradation product patterns, however this does not increase the total amounts of acids released to the medium. Thus, it may be concluded that thickness should not affect significantly organic recycling of the packaging

Maternal mental health predicts risk of developmental problems at 3 years of age: follow up of a community based trial

<p>Abstract</p> <p>Background</p> <p>Undetected and untreated developmental problems can have a significant economic and social impact on society. Intervention to ameliorate potential developmental problems requires early identification of children at risk of future learning and behaviour difficulties. The objective of this study was to estimate the prevalence of risk for developmental problems among preschool children born to medically low risk women and identify factors that influence outcomes.</p> <p>Methods</p> <p>Mothers who had participated in a prenatal trial were followed up three years post partum to answer a telephone questionnaire. Questions were related to child health and development, child care, medical care, mother's lifestyle, well-being, and parenting style. The main outcome measure was risk for developmental problems using the Parents' Evaluation of Developmental Status (PEDS).</p> <p>Results</p> <p>Of 791 children, 11% were screened by the PEDS to be at high risk for developmental problems at age three. Of these, 43% had previously been referred for assessment. Children most likely to have been referred were those born preterm. Risk factors for delay included: male gender, history of ear infections, a low income environment, and a mother with poor emotional health and a history of abuse. A child with these risk factors was predicted to have a 53% chance of screening at high risk for developmental problems. This predicted probability was reduced to 19% if the child had a mother with good emotional health and no history of abuse.</p> <p>Conclusion</p> <p>Over 10% of children were identified as high risk for developmental problems by the screening, and more than half of those had not received a specialist referral. Risk factors for problems included prenatal and perinatal maternal and child factors. Assessment of maternal health and effective screening of child development may increase detection of children at high risk who would benefit from early intervention.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN64070727</p