Accelerated Microstructure Imaging via Convex Optimization (AMICO) in crossing fibers

Mapping the microstructure properties of the local tissues in the brain is crucial to understand any pathological condition from a biological perspective. Most of the existing techniques to estimate the microstructure of the white matter assume a single axon orientation whereas numerous regions of the brain actually present a fiber-crossing configuration. The purpose of the present study is to extend a recent convex optimization framework to recover microstructure parameters in regions with multiple fibers.

Multidetector-row computed tomography in the preoperative diagnosis of intestinal complications caused by clinically unsuspected ingested dietary foreign bodies: a case series emphasizing the use of volume rendering techniques

Objective The present study was aimed at describing a case series where a preoperative diagnosis of intestinal complications secondary to accidentally ingested dietary foreign bodies was made by multidetector-row computed tomography (MDCT), with emphasis on complementary findings yielded by volume rendering techniques (VRT) and curved multiplanar reconstructions (MPR). Materials and Methods The authors retrospectively assessed five patients with surgically confirmed intestinal complications (perforation and /or obstruction) secondary to unsuspected ingested dietary foreign bodies, consecutively assisted in their institution between 2010 and 2012. Demographic, clinical, laboratory and radiological data were analyzed. VRT and curved MPR were subsequently performed. Results Preoperative diagnosis of intestinal complications was originally performed in all cases. In one case the presence of a foreign body was not initially identified as the causal factor, and the use of complementary techniques facilitated its retrospective identification. In all cases these tools allowed a better depiction of the entire foreign bodies on a single image section, contributing to the assessment of their morphology. Conclusion Although the use of complementary techniques has not had a direct impact on diagnostic performance in most cases of this series, they may provide a better depiction of foreign bodies' morphology on a single image section.

Ontogenetic dietary changes in male South American fur seals Arctocephalus australis in northern and central Patagonia, Argentina.

This study assessed ontogenetic dietary changes in male South American fur seals Arctocephalus australis in northern and central Patagonia (Argentina) using stable isotope ratios (δ15 N and δ13 C) in vibrissae and bones. Sucking pups were characterised by higher δ15 N values and lower δ13 C values than older specimens. Weaning was associated with a marked drop of δ15 N values, both in bone and vibrissae. Such a drop was inconsistent with the consumption of local prey and may reveal movement to distant foraging grounds or physiological changes associated with either fasting or rapid growth. Stable isotope ratios indicated that juveniles fed more pelagically than subadults and adults, but that there were no major differences between the 2 latter age categories. As subadults and adults are rather similar in body mass and are much larger than juveniles, body mass may play a role in the ontogenetic dietary changes reported. Nevertheless, demersal benthic prey were always scarce in the diet of male fur seals, which relied primarily on Argentine shortfin squid and small pelagic fish throughout life, though adults also consumed large amounts of decapod crustaceans available at shallow depths. Vibrissae did not reveal regular oscillations of δ15 N or δ13 C, except in 1 individual. Thus, male fur seals from northern and central Patagonia do not appear to migrate regularly between isotopically distinct areas, although nomadic displacements cannot be ruled out.

Analysis of the tensile modulus of polypropylene composites reinforced with stone groundwood fibers

One of the most relevant properties of composite materials to be considered is stiffness. Fiberglass has been used traditionally as a fibrous reinforcing element when stiff materials are required. However, natural fibers are been exploited as replacements for synthetic fibers to satisfy environmental concerns. Among the different natural fibers, wood fibers show the combination of relatively high aspect ratio, good specific stiffness and strength, low density, low cost, and less variability than other natural fibers of such those from annual crops. In this work, composites from polypropylene and stone groundwood fibers from softwood were prepared and mechanically characterized under tensile loads. The Young’s moduli of the ensuing composites were analyzed and their micromechanics aspects evaluated. The reinforcing effect of stone groundwood fibers was compared to that of conventional reinforcement such fiberglass. The Halpin-Tsai model with the modification proposed by Tsai-Pagano accounted fairly for the behavior of PP composites reinforced with stone groundwood fibers. It was also demonstrated that the aspect ratio of the reinforcement plays a role in the Young’s modulus of injection molded specimens

Research on the suitability of organosolv semi-chemical triticale fibers as reinforcement for recycled hdpe composites

The main objective of this research was to study the feasibility of incorporating organosolv semi-chemical triticale fibers as the reinforcing element in recycled high density polyethylene (HDPE). In the first step, triticale fibers were characterized in terms of chemical composition and compared with other biomass species (wheat, rye, softwood, and hardwood). Then, organosolv semi-chemical triticale fibers were prepared by the ethanolamine process. These fibers were characterized in terms of its yield, kappa number, fiber length/diameter ratio, fines, and viscosity; the obtained results were compared with those of eucalypt kraft pulp. In the second step, the prepared fibers were examined as a reinforcing element for recycled HDPE composites. Coupled and non-coupled HDPE composites were prepared and tested for tensile properties. Results showed that with the addition of the coupling agent maleated polyethylene (MAPE), the tensile properties of composites were significantly improved, as compared to non-coupled samples and the plain matrix. Furthermore, the influence of MAPE on the interfacial shear strength (IFSS) was studied. The contributions of both fibers and matrix to the composite strength were also studied. This was possible by the use of a numerical iterative method based on the Bowyer-Bader and Kelly-Tyson equations

Determination of corn stalk fibers' strength through modeling of the mechanical properties of its composites

Worldwide cultivation of corn is expanding, due in part to the increasing production of bioethanol. In consequence, huge amounts of corn stalks residues are been produced. Instead of incineration, we transformed the corn stalks into a semichemical pulp and successfully applied it as reinforcement in polypropylene composites. PP composites reinforced with 40% wt corn stalk single fibers were prepared, and their mechanical properties were evaluated. Through mechanical properties modeling of the composites, the intrinsic tensile strength of the cellulosic fibers that constitute the corn stalk have been determined

Utilization of non-wood pulp in different fibers products

The correct utilization of non-wood raw material allows reducing tree cutting and reduces emissions of carbon dioxide from burning of non-wood plants on farmers fields. Also it allows increasing economical situation in regions that non-wood plants are grown and where they are converted into pulp and paper. Also it gives positive effect on population pressure of work by addition of working place. In the literature survey included an overview of the historical meaning of non-wood pulp on developing paper production and structure of non-wood pulps. Moreover, anatomical and chemical composition of straw, reed and bamboo were studied more detailed. Also, an overview of the utilization of non-wood pulp in papermaking was made. Especially tissue, tree-free and release papers were reviewed. In the experimental part the goal was to investigate suitability of non-wood pulp like wheat straw pulp and bamboo pulp for different fiber products. Finally release and tree-free paper products were selected for experimental studies. It was discovered that wheat straw, especially screened wheat straw, showed good results for release paper. Also utilization of wheat straw and bamboo pulp in tree-free paper showed good results and suitability of these non-wood pulps for tree-free paper production. Also it was noticed that addition of wheat straw pulp gave positive effect on initial wet strength for release and tree-free paper.

Synthesis and characterization of activated carbon fibers from Kevlar

Kevlar [poly (p-phenilylene terephtalamide)], was used as a precursor in the preparation of activated carbon fibers. For this intention, physical and chemical activations were carried out. Activated fibers were physically prepared from the carbonization of the Kevlar and its later activation with CO2 and steam of water, by the other hand; the chemically activated fibers were obtained by means of the impregnation of the material with phosphoric acid and their later carbonization. Different conditions were used and preliminary analyses of the precursor were taken into account (TGA-DTA / IR). The resulting fibers were characterized by N2 (77K) adsorption, infrared spectroscopy, SEM, and immersion calorimetry. Yields and Burn off were also evaluated. The results shows that if you want to synthesize activated carbon fibers from Kevlar strong conditions respect to the commonly used such as water steam, high phosphoric acid concentrations and methods of impregnation are the ones who allows the development of optimal surface areas and pore volumes.

Biochemical Modification of Thermomechanical Pulp Fibers

The first objective of this study was to find out reliable laboratory methods to predict the effect of enzymes on specific energy consumption and fiber properties of TMP pulp. The second one was to find with interactive software called “Knowledge discovery in databases” enzymes or other additives that can be used in finding a solution to reduce energy consumption of TMP pulp. The chemical composition of wood and enzymes, which have activity on main wood components were presented in the literature part of the work. The results of previous research in energy reduction of TMP process with enzymes were also highlighted. The main principles of knowledge discovery have been included in literature part too. The experimental part of the work contains the methods description in which the standard size chip, crushed chip and fiberized spruce chip (fiberized pulp) were used. Different types of enzymatic treatment with different dosages and time were tested during the experiments and showed. Pectinase, endoglucanase and mixture of enzymes were used for evaluation of method reliability. The fines content and fiber length of pulp was measured and used as evidence of enzymes' effect. The refining method with “Bauer” laboratory disc refiner was evaluated as not highly reliable. It was not able to provide high repeatability of results, because of uncontrolled feeding capacity and refining consistency. The refining method with Valley refiner did not have a lot of variables and showed stable and repeatable results in energy saving. The results of experiments showed that efficient enzymes impregnation is probably the main target with enzymes application for energy saving. During the work the fiberized pulp showed high accessibility to enzymatic treatment and liquid penetration without special impregnating equipment. The reason was that fiberized pulp has larger wood surface area and thereby the contact area between the enzymatic solution and wood is also larger. Standard size chip and crushed chip treatment without special impregnator of enzymatic solution was evaluated as not efficient and did not show visible, repeatable results in energy consumption decrease. Thereby it was concluded that using of fiberized pulp and Valley refiner for measurements of enzymes' effectiveness in SEC decrease is more suitable than normal size chip and crushed chip with “Bauer” refiner. Endoglucanase with 5 kg/t dosage showed about 20% energy consumption decrease. Mixture of enzymes with 1.5 kg/t dosage showed about 15% decrease of energy consumption during the refining. Pectinase at different dosages and treatment times did not show significant effect on energy consumption. Results of knowledge discovery in databases showed the xylanase, cellulase and pectinase blend as most promising for energy reduction in TMP process. Surfactants were determined as effective additives for energy saving with enzymes.

Early nutritional determinants in cardio-metabolic programming – A prospective randomized controlled dietary intervention study

Western societies have been faced with the fact that overweight, impaired glucose regulation and elevated blood pressure are already prevalent in pediatric populations. This will inevitably mean an increase in later manifestations of cardio-metabolic diseases. The dilemma has been suggested to stem from fetal life and it is surmised that the early nutritional environment plays an important role in the process called programming. The aim of the present study was to characterize early nutritional determinants associating with cardio-metabolic risk factors in fetuses, infants and children. Further, the study was designated to establish whether dietary counseling initiated in early pregnancy can modify this cascade. Healthy mother-child pairs (n=256) participating in a dietary intervention study were followed from early pregnancy to childhood. The intervention included detailed dietary counseling by a nutritionist targeting saturated fat intake in excess of recommendations and fiber consumption below recommendations. Cardio-metabolic programming was studied by characterizing the offspring’s cardio-metabolic risk factors such as over-activation of the autonomic nervous system, elevated blood pressure and adverse metabolic status (e.g. serum high split proinsulin concentration). Fetal cardiac sympathovagal activation was measured during labor. Postnatally, children’s blood pressure was measured at six-month and four-year follow-up visits. Further, infants’ metabolic status was assessed by means of growth and serum biomarkers (32-33 split proinsulin, leptin and adiponectin) at the age of six months. This study proved that fetal cardiac sympathovagal activity was positively associated with maternal pre-pregnancy body mass index indicating adverse cardio-metabolic programming in the offspring. Further, a reduced risk of high split proinsulin in infancy and lower blood pressure in childhood were found in those offspring whose mothers’ weight gain and amount and type of fats in the diet during pregnancy were as recommended. Of note, maternal dietary counseling from early pregnancy onwards could ameliorate the offspring’s metabolic status by reducing the risk of high split proinsulin concentration, although it had no effect on the other cardio-metabolic markers in the offspring. At postnatal period breastfeeding proved to entail benefits in cardio-metabolic programming. Finally, the recommended dietary protein and total fat content in the child’s diet were important nutritional determinants reducing blood pressure at the age of four years. The intrauterine and immediate postnatal period comprise a window of opportunity for interventions aiming to reduce the risk of cardio-metabolic disorders and brings the prospect of achieving health benefits over one generation.

Carbohydrate intake in children - associations with dietary intakes, growth, serum lipids,and dental health. The STRIP Project

This study is part of the STRIP study, which is a long-term, randomized controlled trial, designed to decrease the exposure of children in the intervention group (n=540) to known risk factors of atherosclerosis. The main focus of the intervention was the quality of dietary fat. The control group (n=522) did not receive any individualized counselling. Food consumption was evaluated with food records, and blood samples were drawn and growth was measured regularly for all participating children from 13 months to 9 years. A subsample of 66 children participated in a dental health survey. The number of studies on children’s carbohydrate intake, especially fibre intake, is insufficient. The current international recommendations for fibre intake in children are based on average assumptions and data extrapolated from intakes in adults and intake recommendations for adults. Finnish nutrition recommendations lack strict recommendations for dietary fibre in children. Due to fibre’s high bulk volume, excessive dietary fibre is considered to decrease energy density and hence it may have an adverse effect on growth. If fats are reduced from the diet, the low-fat diet may become high in sucrose. Therefore, especially in the STRIP study, it is important to determine the use of fibre and sucrose in children and possible associations with growth and nutrition as well as dental health. The results of the present study indicate that a high fibre intake does not displace energy or disturb growth in children and that children with high fibre intake have better quality of diet than those with low fibre intake. Additionally, dietary fibre intake associated inversely with serum cholesterol concentration. Other carbohydrates also affected serum lipid levels as well, since total carbohydrates, sucrose, and fructose increased serum triglyceride concentration. Total carbohydrate intake reduced HDL cholesterol concentration only in children with apoE3 or apoE4 phenotype. Over the period from the 1970s to the 1990s the dental health of children in Finland has substantially improved despite an increase in sucrose intake. The improvement was thought to be due to improved dental hygiene and the use of fluorine. However, during the past twenty years improvement in dental health has stopped. The present study showed that high long-term sugar intake increases risk of caries in children. High intake of sugar had also negative effects on the diet of children, because it worsens dietary quality by displacing essential nutrients. Furthermore, the quality of dietary fat was worse in children with high sucrose intake. In this study the children’s high sucrose intake was not associated with overweight, but interestingly, it associated inversely with growth.

The use of dietary supplements and medication among Finnish elite athletes

Background: Dietary supplements are widely used among elite athletes but the prevalence of dietary supplement use among Finnish elite athletes is largely not known. The use of asthma medication is common among athletes. In 2009, the World Anti-Doping Agency (WADA) and the International Olympic Committee (IOC) removed the need to document asthma by lung function tests before the use of inhaled β2-agonists. Data about medication use by Paralympic athletes (PA) is limited to a study conducted at the Athens Paralympics. Aims: To investigate the prevalence of the use of self-reported dietary supplements, the use of physician-prescribed medication and the prevalence of physician-diagnosed asthma and allergies among Finnish Olympic athletes (OA). In addition, the differences in the selfreported physician-prescribed medication use were compared between the Finnish Olympic and the Paralympic athletes. Subjects and methods: Two cross-sectional studies were conducted in Finnish Olympic athletes receiving financial support from the Finnish Olympic Committee in 2002 (n=446) and in 2009 (n=372) and in Finnish top-level Paralympic athletes (n= 92) receiving financial support from Finnish Paralympic committee in 2006. The results of the Paralympic study were compared with the results of the Olympic study conducted in 2009. Both Olympic and Paralympic athletes filled in a similar semi-structured questionnaires. Results: Dietary supplements were used by 81% of the athletes in 2002 and by 73% of the athletes in 2009. After adjusting for age-, sex- and type of sport, the odds ratio OR (95% confidence interval, CI) for use of any dietary supplement was significantly less in 2009 as compared with the 2002 situation (OR 0.62; 95% CI 0.43-0.90). Vitamin D was used by 0.7% of the athletes in year 2002 but by 2% in 2009 (ns, p = 0.07). The use of asthma medication increased from 10.4 % in 2002 to 13.7% in 2009 (adjusted OR 1.71; 95% CI 1.08-2.69). For example, fixed combinations of inhaled long-acting β2-agonists (LABA) and inhaled corticosteroids (ICS) were used three times more commonly in 2009 than in 2002 (OR 3.38; 95% CI 1.26-9.12). The use of any physician-prescribed medicines (48.9% vs. 33.3%, adjusted OR 1.99; 95% CI 1.13-3.51), painkilling medicines (adjusted OR 2.61; 95% CI 1.18-5.78), oral antibiotics (adjusted OR 4.10; 95% CI 1.30-12.87) and anti-epileptic medicines (adjusted OR 37.09; 95% CI 5.92-232.31) was more common among the PA than in the OA during the previous seven days. Conclusions: The use of dietary supplements is on the decline among Finnish Olympic athletes. The intake of some essential micronutrients, such as vitamin D, is suprisingly low and this may even cause harm in those well-trained athletes. The use of asthma medication, especially fixed combinations of LABAs and ICS, is clearly increasing among Finnish Olympic athletes. The use of any physician-prescribed medicine, especially those to treat chronic diseases, seems to be more common among the Paralympians than in the Olympic athletes.

The effect of soy dietary supplement and low dose of hormone therapy on main cardiovascular health biomarkers: a randomized controlled trial

PURPOSE: To assess the effects of a soy dietary supplement on the main biomarkers of cardiovascular health in postmenopausal women compared with the effects of low-dose hormone therapy (HT) and placebo.METHODS: Double-blind, randomized and controlled intention-to-treat trial. Sixty healthy postmenopausal women, aged 40-60 years, 4.1 years mean time since menopause were recruited and randomly assigned to 3 groups: a soy dietary supplement group (isoflavone 90mg), a low-dose HT group (estradiol 1 mg plus noretisterone 0.5 mg) and a placebo group. Lipid profile, glucose level, body mass index, blood pressure and abdominal/hip ratio were evaluated in all the participants at baseline and after 16 weeks. Statistical analyses were performed using the χ2 test, Fisher's exact test, Kruskal-Wallis non-parametric test, analysis of variance (ANOVA), paired Student's t-test and Wilcoxon test.RESULTS: After a 16-week intervention period, total cholesterol decreased 11.3% and LDL-cholesterol decreased 18.6% in the HT group, but both did not change in the soy dietary supplement and placebo groups. Values for triglycerides, HDL-cholesterol, glucose level, body mass index, blood pressure and abdominal/hip ratio did not change over time in any of the three groups.CONCLUSION: The use of dietary soy supplement did not show any significant favorable effect on cardiovascular health biomarkers compared with HT. Clinical Trial Registry: The trial is registered at the Brazilian Clinical Trials Registry (Registro Brasileiro de Ensaios Clínicos - ReBEC), number RBR-76mm75.

Family-based dietary intervention in the STRIP study – influences on diet and diet-related attitudes

The focus of this dissertation was to investigate the effects of family-based dietary intervention during childhood and adolescence. The participants comprised of children and parents who participated in a longitudinal, randomised atherosclerosis prevention trial (STRIP study). The intervention families (n=540) took part in a dietary intervention since the child’s age of 8- months. The control group (n=522) did not receive any tailored dietary intervention. The main focus of the intervention was to improve the quality of dietary fat. The diet of children and parents was evaluated by daily food records and dietrelated attitudes by a questionnaire. The dietary intervention influenced, favourably, the dietary fat quality in children and parents. Fat quality improved mainly by the decrease of saturated fat intake. Some minor effects of the intervention were also observed in children’s fruit and vegetable (F&V) consumption although the F&V consumption was very low. The intervention increased parental interest in healthy eating, but there was no difference in interest in natural products or in attitudes towards hedonic eating attitudes between the intervention and control parents. Parents’ interest in healthy eating associated with parents’ and children’s high fruit and vegetable consumption but not with their fat quality ratio. On the other hand, dietary fat quality improved at every level of interest in healthy eating. It seems that the main target of the intervention, the dietary fat quality of the children, was promoted effectively. In the future, more emphasis should be given on increasing unsaturated fat intake and on elevating F&V consumption in children. Children’s diet, especially F&V consumption, associated with diet-related attitudes of the parents. Therefore, co-operation with parents and family-based premises for working should be capitalized upon when promoting healthy eating in children and adolescents.

Individual dietary counselling during and after pregnancy: Impact on diet and body weight

In Finland, maternity and child health clinics play a key role in promoting health in young families. Currently, obesity causes the greatest challenges to clinics. In obese pregnant women, an increased risk for metabolic diseases exist which can affect both the mother and child. The purpose of this thesis was to explore the role of dietary counselling: in Finnish health clinics; in the regulation of dietary intake; and in affecting the body weight of women. The main aim was to test the effect of dietary counselling and probiotic intervention on dietary intake and maternal body weight during and after pregnancy. In addition to dietary counselling, the effect of other factors, such as eating behaviour on dietary intake and body weight control after pregnancy was assessed. Another aim was also to evaluate dietary counselling practices by nurses (n = 327) in Finnish health clinics assessed by a questionnaire. At the beginning of the pregnancy, women (n = 256) enrolled in a dietary intervention study, were randomised into three groups. One group received dietary counselling with probiotics, one had counselling with placebo and the third group was the control group. The control group consisted of women whom did not receive counselling and took placebo. Probiotics and placebo supplements were used until the end of exclusive breastfeeding or six months after pregnancy. Women were followed from early pregnancy up to four years after pregnancy. Follow-up visits took place three times during pregnancy, at one and six months, and one, two and four years after pregnancy. Dietary counselling, provided by a nutritionist, aimed to influence the quality of dietary fat intake. Dietary counselling is important to provide in clinics, as determined by the nurses, and these nurses expressed a want to improve their own nutritional knowledge through education. The nurses had varying knowledge of current dietary recommendations. Dietary counselling for women during and after pregnancy resulted in beneficial changes in dietary intake up to one year after pregnancy and body weight and waist circumference up to four years after pregnancy. Probiotics had a beneficial effect together with dietary counselling on waist circumference until one year after pregnancy, but not throughout the long term, four years after pregnancy. Other factors, such as eating behaviour, associated with dietary intake and body weight control after pregnancy. Specifically, dietary recommendations are reached amongst women whom had high cognitive restraint in their eating behaviour and did not demonstrate uncontrolled eating. Overweight women more frequently emotionally ate compared to normal weight women and women with central adiposity related more frequently to having an uncontrolled eating behaviour than women with normal waist circumference. In addition, being overweight prior to pregnancy and excessive weight gain during pregnancy associated with increased body weight retention after pregnancy. This study showed that individual dietary counselling is useful in influencing dietary intake which adheres to dietary recommendations and this counselling influences, favourably, body weight after pregnancy. Especially, women with the risk for weight retention, such as women who have emotional and uncontrolled eating behaviours, who were overweight prior to pregnancy or those who had excessive weight gain during pregnancy, may benefit from individual dietary counselling. This study underscores the need to develop dietary counselling practices for pregnant women and their follow-up after pregnancy in Finnish health clinics. These practices include increasing the efficacy of the counselling such as collaboration with families, having knowledgable health professionals and having sufficient resources.