Mathematical modeling of electro-rotation spectra of small particles in liquid solutions: Application to human erythrocyte aggregates

Electro-rotation can be used to determine the dielectric properties of cells, as well as to observe dynamic changes in both dielectric and morphological properties. Suspended biological cells and particles respond to alternating-field polarization by moving, deforming or rotating. While in linearly polarized alternating fields the particles are oriented along their axis of highest polarizability, in circularly polarized fields the axis of lowest polarizability aligns perpendicular to the plane of field rotation. Ellipsoidal models for cells are frequently applied, which include, beside sphere-shaped cells, also the limiting cases of rods and disks. Human erythrocyte cells, due to their particular shape, hardly resemble an ellipsoid. The additional effect of rouleaux formation with different numbers of aggregations suggests a model of circular cylinders of variable length. In the present study, the induced dipole moment of short cylinders was calculated and applied to rouleaux of human erythrocytes, which move freely in a suspending conductive medium under the effect of a rotating external field. Electro-rotation torque spectra are calculated for such aggregations of different length. Both the maximum rotation speeds and the peak frequencies of the torque are found to depend clearly on the size of the rouleaux. While the rotation speed grows with rouleaux length, the field frequency nup is lowest for the largest cell aggregations where the torque shows a maximum.

Normative data for the Brazilian population in the Boston Diagnostic Aphasia Examination: influence of schooling

In Neurolinguistics, the use of diagnostic tests developed in other countries can create difficulties in the interpretation of results due to cultural, demographic and linguistic differences. In a country such as Brazil, with great social contrasts, schooling exerts a powerful influence on the abilities of normal individuals. The objective of the present study was to identify the influence of schooling on the performance of normal Brazilian individuals in the Boston Diagnostic Aphasia Examination (BDAE), in order to obtain reference values for the Brazilian population. We studied 107 normal subjects ranging in age from 15 to 84 years (mean ± SD = 47.2 ± 17.6 years), with educational level ranging from 1 to 24 years (9.9 ± 4.8 years). Subjects were compared for scores obtained in the 28 subtests of the BDAE after being divided into groups according to age (15 to 30, N = 24, 31 to 50, N = 33 and 51 years or more, N = 50) and education (1 to 4, N = 26, 5 to 8, N = 17 and 9 years or more, N = 61). Subjects with 4 years or less of education performed poorer in Word Discrimination, Visual Confrontation Naming, Reading of Sentences and Paragraphs, and Primer-Level Dictation (P < 0.05). When breakdown by schooling was 8 years or less, subjects performed poorer in all subtests (P < 0.05), except Responsive Naming, Word Recognition and Word-Picture Matching. The elderly performed poorer (P < 0.05) in Complex Ideational Material, Visual Confrontation Naming, Comprehension of Oral Spelling, Written Confrontation Naming, and Sentences to Dictation. We present the reference values for the cut-off scores according to educational level.

Purinergic signalling: past, present and future

The discovery of non-adrenergic, non-cholinergic neurotransmission in the gut and bladder in the early 1960's is described as well as the identification of adenosine 5'-triphosphate (ATP) as a transmitter in these nerves in the early 1970's. The concept of purinergic cotransmission was formulated in 1976 and it is now recognized that ATP is a cotransmitter in all nerves in the peripheral and central nervous systems. Two families of receptors to purines were recognized in 1978, P1 (adenosine) receptors and P2 receptors sensitive to ATP and adenosine diphosphate (ADP). Cloning of these receptors in the early 1990's was a turning point in the acceptance of the purinergic signalling hypothesis and there are currently 4 subtypes of P1 receptors, 7 subtypes of P2X ion channel receptors and 8 subtypes of G protein-coupled receptors. Both short-term purinergic signalling in neurotransmission, neuromodulation and neurosecretion and long-term (trophic) purinergic signalling of cell proliferation, differentiation, motility, death in development and regeneration are recognized. There is now much known about the mechanisms underlying ATP release and extracellular breakdown by ecto-nucleotidases. The recent emphasis on purinergic neuropathology is discussed, including changes in purinergic cotransmission in development and ageing and in bladder diseases and hypertension. The involvement of neuron-glial cell interactions in various diseases of the central nervous system, including neuropathic pain, trauma and ischemia, neurodegenerative diseases, neuropsychiatric disorders and epilepsy are also considered.

The inhibitory role of sympathetic nervous system in the Ca2+-dependent proteolysis of skeletal muscle

Mammalian cells contain several proteolytic systems to carry out the degradative processes and complex regulatory mechanisms to prevent excessive protein breakdown. Among these systems, the Ca2+-activated proteolytic system involves the cysteine proteases denoted calpains, and their inhibitor, calpastatin. Despite the rapid progress in molecular research on calpains and calpastatin, the physiological role and regulatory mechanisms of these proteins remain obscure. Interest in the adrenergic effect on Ca2+-dependent proteolysis has been stimulated by the finding that the administration of β2-agonists induces muscle hypertrophy and prevents the loss of muscle mass in a variety of pathologic conditions in which calpains are activated. This review summarizes evidence indicating that the sympathetic nervous system produces anabolic, protein-sparing effects on skeletal muscle protein metabolism. Studies are reviewed, which indicate that epinephrine secreted by the adrenal medulla and norepinephrine released from adrenergic terminals have inhibitory effects on Ca2+-dependent protein degradation, mainly in oxidative muscles, by increasing calpastatin levels. Evidence is also presented that this antiproteolytic effect, which occurs under both basal conditions and in stress situations, seems to be mediated by β2- and β3-adrenoceptors and cAMP-dependent pathways. The understanding of the precise mechanisms by which catecholamines promote muscle anabolic effects may have therapeutic value for the treatment of muscle-wasting conditions and may enhance muscle growth in farm species for economic and nutritional purposes.

Rescuing axons from degeneration does not affect retinal ganglion cell death

After a traumatic injury to the central nervous system, the distal stumps of axons undergo Wallerian degeneration (WD), an event that comprises cytoskeleton and myelin breakdown, astrocytic gliosis, and overexpression of proteins that inhibit axonal regrowth. By contrast, injured neuronal cell bodies show features characteristic of attempts to initiate the regenerative process of elongating their axons. The main molecular event that leads to WD is an increase in the intracellular calcium concentration, which activates calpains, calcium-dependent proteases that degrade cytoskeleton proteins. The aim of our study was to investigate whether preventing axonal degeneration would impact the survival of retinal ganglion cells (RGCs) after crushing the optic nerve. We observed that male Wistar rats (weighing 200-400 g; n=18) treated with an exogenous calpain inhibitor (20 mM) administered via direct application of the inhibitor embedded within the copolymer resin Evlax immediately following optic nerve crush showed a delay in the onset of WD. This delayed onset was characterized by a decrease in the number of degenerated fibers (P<0.05) and an increase in the number of preserved fibers (P<0.05) 4 days after injury. Additionally, most preserved fibers showed a normal G-ratio. These results indicated that calpain inhibition prevented the degeneration of optic nerve fibers, rescuing axons from the process of axonal degeneration. However, analysis of retinal ganglion cell survival demonstrated no difference between the calpain inhibitor- and vehicle-treated groups, suggesting that although the calpain inhibitor prevented axonal degeneration, it had no effect on RGC survival after optic nerve damage.

Effect of sugar and water contents on non-expanded cassava flour extrudates

The effects of sucrose and water contents on cassava flour processed by extrusion at varied concentrations of sucrose (0-20% w/w) and water (28-42% w/w) were studied by applying response surface methodology. The extrusion of the mixtures was performed in a twin screw extruder fitted to a torque rheometer. The specific mechanical energy (SME) dissipated inside a conical twin-screw extruder was measured. Water absorption index (WAI), water solubility index (WSI) and paste viscosity readings (cold viscosity (CV), peak viscosity (PV), breakdown (BD) and set back (SB)) during a gelatinization-retrogradation cycle measured in a Rapid Visco Analyzer were determined on non-directly extruded products. The results indicated that SME and WSI decreased as a function of water and sucrose contents. WAI and pasting properties were influenced by water content. A non antiplasticizing effect of the sucrose content was observed on pasting properties, suggesting that sucrose did not reduce the availability of water available for gelatinizing cassava flour during the extrusion process. The nature of the optimum point was characterized as a saddle point for WAI, WSI, PV and BD, whereas SME showed a maximum and CV and SB a minimum. The results indicated to be valuable for the production of non-expanded cassava flour extrudates with desirable functional properties for specific end users.

Volatile profile and physical, chemical, and biochemical changes in fresh cut watermelon during storage

Existing data about the aroma of fresh-cut watermelon and the metabolic changes that occur with minimal processing are scarce. Given the close relationship that exists between aroma, texture, and quality characteristics, it is necessary to investigate the changes in the volatile profile and texture of watermelon, a fruit extensively sold in supermarket chains throughout Brazil. The objective of this work was to analyze the volatile profile using solid phase microextraction (SPME) as well as texture changes in fresh-cut watermelon stored at 5 °C for ten days. Chromatography associated with sensory analysis (sniffing) led us to conclude that 9-carbon (C9) alcohols and aldehydes are the major responsible for the flavor and aroma of minimally processed watermelon stored at 5 ± 1 °C/90 ± 5% RH for ten days, and also that the aroma diminishes in intensity with storage, but it does not affect the final quality of the product. It was noted that the amount of drained liquid, soluble pectin, and weight loss increased during storage concurrently with a reduction in firmness and a structural breakdown of the cells. Pectin methyl esterase activity remained constant and polygalacturonase activity was not detected.

Project Charter, Scope, and Time Management In the Movie Industry

This thesis explores how the project charter development, project scope management, and project time management are executed in a Finnish movie production. The deviations and analogies between a case movie production and best practices suggested in PMBOK are presented. Empirical material from the case is gathered with two semi-structured interviews with a producer and a line producer. The interview data is categorized according to PMBOK knowledge areas. The analysis is complemented with movie industry specific norms found in popular movie production guides. The described and observed methods are linked together and the relationship between them is discussed. The project charter development, which is referred as a green light process in the movie industry, is mostly analogous between all areas. The deviations are in the level of formality. The green lighting in the case movie was accomplished without bureaucratic reports described in movie production guides. The empirical material shows that project management conventions and movie industry employ similar methods especially in scope management. Project management practices introduce a work breakdown structure (WBS) method, and movie production accomplishes the same task by developing a shooting script. Time management of the case movie deviates on most parts from the methods suggested in PMBOK. The major deviation is resource management. PMBOK suggests creating a resource breakdown structure. The case movie production accomplished this through budgeting process. Furthermore the popular movie production guides also disregard resource management as sovereign process. However the activity listing is quite analogous between the case movie and PMBOK. The final key observation is that although there is a broad set of effective and detailed movie industry specific methods, a comprehensive methodology that would cover the whole production process, such as Prince2 or Scrum, seems to be missing from the movie industry.

Characterization and nutritional value of precooked products of kiwicha grains (Amaranthus caudatus)

AbstractKiwicha has significant nutritional characteristics. It is commonly used as a puffed product, but there is little research on the lamination process. In this paper, the physical, functional properties, chemical composition and acceptability of the precooked kiwicha grains were studied. Puffed (PK) and laminated kiwicha (LK) were made. Puffed amaranth (CPA) was used as a commercial reference standard. The raw grain (RG) showed a higher bulk density (0.85 g/ml) than in PK (0.18 g/ml) and LK (0.38 g/ml). Both products had a good expansion. The yellow index decreased in PK (50.92) and LK (45.87) respect to RG (65.64). The largest was CPA (58.54). In all the products, the precooking increased the index of absorption, solubility and swelling power. Also, they showed major pasting temperature, low peak viscosity and breakdown viscosity. In both formulated products, the content of total, soluble and insoluble dietary fibre decreased during the precooking process. The content of protein was optimal (between 14.57-14.59 g/100g). PK had high acceptability (5.84), preference (84.48%), purchase (38.79%) and consumption (43.96%) intention. The lowest was CPA. This work demonstrates that it’s feasible to make precooked products with good quality characteristics, chemical composition and acceptability for the development of new products.

Project charter, scope, and time management in the movie industry

This thesis explores how the project charter development, project scope management, and project time management are executed in a Finnish movie production. The deviations and analogies between a case movie production and best practices suggested in PMBOK are presented. Empirical material from the case is gathered with two semi-structured interviews with a producer and a line producer. The interview data is categorized according to PMBOK knowledge areas. The analysis is complemented with movie industry specific norms found in popular movie production guides. The described and observed methods are linked together and the relationship between them is discussed. The project charter development, which is referred as a green light process in the movie industry, is mostly analogous between all areas. The deviations are in the level of formality. The green lighting in the case movie was accomplished without bureaucratic reports described in movie production guides. The empirical material shows that project management conventions and movie industry employ similar methods especially in scope management. Project management practices introduce a work breakdown structure (WBS) method, and movie production accomplishes the same task by developing a shooting script. Time management of the case movie deviates on most parts from the methods suggested in PMBOK. The major deviation is resource management. PMBOK suggests creating a resource breakdown structure. The case movie production accomplished this through budgeting process. Furthermore the popular movie production guides also disregard resource management as sovereign process. However the activity listing is quite analogous between the case movie and PMBOK. The final key observation is that although there is a broad set of effective and detailed movie industry specific methods, a comprehensive methodology that would cover the whole production process, such as Prince2 or Scrum, seems to be missing from the movie industry.

Kosteuden vaikutus tehotransistorin estojännitteeseen

Tämän työn tavoitteena on vastata hypoteesiin jonka mukaan kosteus aiheuttaisi IGBT:n estojännitteen aleneman ja siitä seuraavan taajuusmuuttajan vikaantumisen. Työssä tarkastellaan erään ABB Drivesin käyttämän IGBT-moduulin estojännitteen käyttäytymistä kosteudelle altistamisen jälkeen. Työn teoriaosuudessa kerrotaan taajuusmuuttajasta sekä IGBT:n rakenteesta ja käyttäytymisestä erilaisissa tilanteissa. Estojännitettä tutkitaan käyräseuraajan avulla, kun IGBT on altistettu kosteudelle. Tutkimuksessa toteutettiin yhteensä kolme erilaista olosuhdesimulaatiota. Tutkittavissa IGBT-moduuleissa havaittiin vähäistä estojännitteen alenemaa sekä vuotovirran kasvua. Estojännitteen aleneman todetti-in olevan riittämätön vikaannuttaakseen taajuusmuuttajan. Estojännite säilyi korkeampana kuin valmistajan datalehdessä ilmoittama maksimiarvo. Tutkimuksen johtopäätöksenä on ettei kosteus ole aiheuttanut taajuusmuuttajan vikaantumista. Työn lopussa esitellään tapoja joilla taajuusmuuttajan kokemia olosuhteita voitaisiin seurata jatkossa tarkemmin.

Työn osituksen kehittäminen kustannusten kirjaamisen ja seurannan tarkentamiseksi projekteissa

Työn päätavoite on selvittää kohdeyrityksen projektien tehtävien jakoon ja työn jäsentämiseen käytettävän työn osituksen rakenteen ongelmat projektikustannusten kirjaamisessa. Tämän lisäksi tavoitellaan kustannusläpi-näkyvyyden kasvua, mittaamisen helpottumista ja kustannusarvioinnin tarkentumista antamalla kehitys-ehdotuksia rakenteen tarkentamiseksi ja yksinkertaistamiseksi. Työ on laadullista ja toiminnallista tapaus-tutkimusta. Teoriaosuuden aineistona on tieteellisiä artikkeleita, kirjoja, lehtiä ja muita aiheeseen liittyviä julkaisuja. Empiirinen osa koostuu yrityksen sisäisistä haastatteluista sekä esikuva-analyysihaastatteluista. Kehitysehdotusten analysointiin ja valintaan käytetään GAP–analyysiä ja toteutettavuustarkastelua. Työn keskeisimpänä tuloksena on neljä kehitysehdotusta, jotka pohjautuvat teorioiden suosituksiin työn osituksen rakenteen sisällöstä. Tällä työllä pyritään myös tuomaan esille kehitystarvetta yrityksessä ja antamaan suunta sekä alkusysäys kehitysprosessille kohti toimivampaa projektien kustannusseurantaa.

Moving lipids : ceramides, glycosphingolipids and the glycolipid transfer protein

Lipid movement in cells occurs by a variety of methods. Lipids diffuse freely along the lateral plane of a membrane and can translocate between the lipid leaflets, either spontaneously or with the help of enzymes. Lipid translocation between the different cellular compartments predominantly takes place through vesicular transport. Specialized lipid transport proteins (LTPs) have also emerged as important players in lipid movement, as well as other cellular processes. In this thesis we have studied the glycolipid transport protein (GLTP), a protein that transports glycosphingolipids (GSLs). While the in vitro properties of GLTP have been well characterized, its cell biological role remains elusive. By altering GSL and GLTP levels in cells, we have extracted clues towards the protein's function. Based on the results presented in this thesis and in previous works, we hypothesize that GLTP is involved in the GSL homeostasis in cells. GLTP most likely functions as a transporter or sensor of newly synthesized glucosylceramide (GlcCer), at or near the site of GlcCer synthesis. GLTP also seems to be involved in the synthesis of globotriacylceramide, perhaps in a manner that is similar to that of the fourphosphate adaptor protein 2, another GlcCer-transporting LTP. Additionally, we have developed and studied a novel method of introducing ceramides to cells, using a solvent-free approach. Ceramides are important lipids that are implicated in several cellular functions. Their role as proapoptotic molecules is particularly evident. Ceramides form stable bilayer structures when complexed with cholesterol phosphocholine (CholPC), a large-headgroup sterol. By adding ceramide/CholPC complexes to the growth medium, various chain length ceramides were successfully delivered to cells in culture. The uptake rate was dependent on the chain length of the ceramide, where shorter lipids were internalized more quickly. The rate of uptake also determined how the cells metabolised the ceramides. Faster uptake favored conversion of ceramide to GlcCer, whereas slower delivery resulted mainly in breakdown of the lipid.

Home schooling in view of John Calvin : a study in education and communion of saints /

This study explores the tension that has emerged around the rise of home schooling in a faith-community strongly committed to establishing and maintaining day schools in the tradition of John Calvin. It aims to identify and understand factors that contributed to this tension and to find ways to bridge, diffuse, reduce, or eliminate it. In line with Calvin, personal convictions, and the nature of the community, the study takes a Christian epistemological and axiological stance. Its premise is that the integrity of the commvmity is more important than the manner in which its children are taught. The study reviews relevant literature and several interviews. It considers both secular and Christian literature to understand communities, community breakdown, and community restoration. It also examines literature about the significance of home, school, and community relationships; the attraction of Reformed day schools; and the appeal of home schooling. Interviews were conducted with 4 home schooling couples and 2 focus groups. One focus group included local school representatives, and the other home schoolers and school representatives from an area with reputedly less tension on the issue. Interviews were designed for participants to give their perspectives on reasons for home schooling, the existing tension, and ways to resolve the issues. The study identifies the rise of home schooling in this particular context as the initial issue and the community's deficiency to properly deal with it as the chief cause for the rising tensions. However, I argue that, within the norms the community firmly believes in, home schooling need not jeopardize its integrity. I call for personal, social, and spiritual renewal to restore the covenant community in gratitude to God.

The role of cyclic nucleotides in modulation of crayfish neuromuscular junctions by a neuropeptide /

DF2, a heptapeptide, is a member of the family of FMRFamide-like peptides and has been shown to increase the amount of transmitter released at neuromuscular junctions of the crayfish, Procambarus clarkit Recent evidence has shown that protein kinase C (PKC), calcium/calmodulin-dependent protein kinase II (CaMKII) and the cAMPdependent protein kinase (PKA) play a role in the neuromodulatory pathway of DF2. The involvement of these kinases led to the prediction that a G-protein-coupled receptor (GPCR) is activated by DF2 due to the role that each kinase plays in traditional GPCR pathways seen in other organisms and in other cells. G-proteins can also act on an enzyme that generates cyclic guanosine monophosphate (cGMP) which mediates its effects through a cGMP-dependent protein kinase (PKG). This thesis addresses the question of whether or not DF2's effects on synaptic transmission in crayfish are mediated by the cyclic nucleotides cAMP and cGMP. The effects of DF2 on synaptic transmission were examined using deep abdominal extensor muscles of the crayfish Procambarus clarkii. An identified motor neuron was stimulated, and excitatory post-synaptic potentials (EPSPs) were recorded in abdominal extensor muscle LI . A number of activators and inhibitors were used to determine whether or not cAMP, PKA, cGMP and PKG mediate the effect of this peptide. Chemicals that are known to activate PKA (Sp-cAMPS) and/or PKG (8-pCPTcGMP) mimic and potentiate DF2's effect by increasing EPSP amplitude. Inhibitors of either PKA (Rp-cAMPS) or PKG (Rp-8-pCPT-cGMPS) block a portion of the increase in EPSP amplitude induced by the peptide. When both kinase inhibitors are applied simultaneously, the entire effect of DF2 on EPSPs is blocked. The PKG inhibitor blocks the effects of a PKG activator but does not alter the effect of a PKA activator on EPSP amplitude. Thus, the PKG inhibitor appears to be relatively specific for PKG. A trend in the data suggests that the PKA inhibitor blocks a portion of the response elicited by the PKG activator. Thus, the PKA inhibitor may be less specific for PKA. Phosphodiesterase inhibitors, which are known to inhibit the breakdown of cAMP (IBMX) and/or cGMP (mdBAMQ), potentiate the effect of the peptide. These results support the hypothesis that cAMP and cGMP, acting through their respective protein kinase enzymes, mediate the ability of DFi to increase transmitter output.