18 research outputs found

    Hidden Markov model finds behavioral patterns of users working with a headmouse driven writing tool

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    We studied user behaviors when the cursor is directed by a head in a simple control task. We used an intelligent writing tool called Dasher. Hidden Markov models (HMMs) were applied to separate behavioral patterns. We found that a similar It is argued that the recognition of general application specific behavioral patterns should he of help for adaptive human-computer interfaces

    A possible rheological model of gum candies

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    An appropriate rheological model can be used in production of good quality gum candy required by consumers. For this purpose Creep-Recovery Test (CRT) curves were recorded with a Stable Micro System TA.XT-2 precision texture analyser with 75 mm diameter cylinder probe on gum candies purchased from the local market. The deformation speed was 0.2 mm s−1, the creeping- and recovering time was 60 s, while the loading force was set to 1 N, 2 N, 5 N, 7 N, and 10 N. The two-element Kelvin-Voigt-model, a three-element model, and the four-element Burgers-model were fitted on the recorded creep data, and then the parameters of the models were evaluated. The best fitting from the used models was given by the Burgers model

    Blood–Brain Barrier Dysfunction in L-Ornithine Induced Acute Pancreatitis in Rats and the Direct Effect of L-Ornithine on Cultured Brain Endothelial Cells

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    BACKGROUND: In severe acute pancreatitis (AP) the CNS is affected manifesting in neurological symptoms. Earlier research from our laboratory showed blood–brain barrier (BBB) permeability elevation in a taurocholate-induced AP model. Here we aimed to further explore BBB changes in AP using a different, non-invasive in vivo model induced by l-ornithine. Our goal was also to identify whether l-ornithine, a cationic amino acid, has a direct effect on brain endothelial cells in vitro contributing to the observed BBB changes. METHODS: AP was induced in rats by the intraperitoneal administration of l-ornithine-HCl. Vessel permeability and the gene expression of the primary transporter of l-ornithine, cationic amino acid transporter-1 (Cat-1) in the brain cortex, pancreas, liver and lung were determined. Ultrastructural changes were followed by transmission electron microscopy. The direct effect of l-ornithine was tested on primary rat brain endothelial cells and a triple co-culture model of the BBB. Viability and barrier integrity, including permeability and TEER, nitrogen monoxide (NO) and reactive oxygen species (ROS) production and NF-κB translocation were measured. Fluorescent staining for claudin-5, occludin, ZO-1, β-catenin, cell adhesion molecules Icam-1 and Vcam-1 and mitochondria was performed. Cell surface charge was measured by laser Doppler velocimetry. RESULTS: In the l-ornithine-induced AP model vessel permeability for fluorescein and Cat-1 expression levels were elevated in the brain cortex and pancreas. On the ultrastructural level surface glycocalyx and mitochondrial damage, tight junction and basal membrane alterations, and glial edema were observed. l-ornithine decreased cell impedance and elevated the BBB model permeability in vitro. Discontinuity in the surface glycocalyx labeling and immunostaining of junctional proteins, cytoplasmic redistribution of ZO-1 and β-catenin, and elevation of Vcam-1 expression were measured. ROS production was increased and mitochondrial network was damaged without NF-κB, NO production or mitochondrial membrane potential alterations. Similar ultrastructural changes were seen in l-ornithine treated brain endothelial cells as in vivo. The basal negative zeta potential of brain endothelial cells became more positive after l-ornithine treatment. CONCLUSION: We demonstrated BBB damage in the l-ornithine-induced rat AP model suggesting a general, AP model independent effect. l-ornithine induced oxidative stress, decreased barrier integrity and altered BBB morphology in a culture BBB model. These data suggest a direct effect of the cationic l-ornithine on brain endothelium. Endothelial surface glycocalyx injury was revealed both in vivo and in vitro, as an additional novel component of the BBB-related pathological changes in AP. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12987-022-00308-0

    Display activity and seasonality of faecal sexual steroids in male great bustard ( Otis tarda L.)

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    The non-invasive faecal sampling and RIA was used to measure faecal equivalents of testosterone (T), dehydroepiandrosterone (DHEA), oestradiol-17β (E2) and progesterone (P4) in juvenile and adult great bustard males. Possible connections of diurnal and seasonal changes of sexual steroid levels and display activity were studied. Correlations were found between sexual steroid equivalent levels of faeces and display activity and agonistic behaviour in the different phases of annual cycle of adult males. In early display period increasing levels of androgens were measured, during main display period very high androgen dominance was observable against E2 and P4. During postnuptial moult strong T decrease and DHEA and P4 increase were detected. Elevation of E2 was measured during wintering. In juveniles level of DHEA was higher than level of T suggesting its importance in immature males. Decrease of T was detected between reproductive period and postnuptial moult and DHEA between reproduction and wintering, accompanying with E2 elevation. The inhibiting effect of inclement weather on gonad functions also was detected in our study. We suppose that the unexpected cold weather with strong wind depressed the levels of androgens both in juveniles and adults and the increase of faecal E2 was also detected

    Influence of composition and storage conditions on chocolate hardness and heat resistance

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    The EU Chocolate Directive 2000/36/EC allows the use of the vegetable fats CBEs and CBIs up to a maximum of 5% in chocolate. Manufacturers and users must know how this has an influence on the properties of chocolate. The objective of the work reported here was to find out by systematic investigations, which effect CBEs/CBIs have on the quality parameters, hardness and heat resistance of chocolate. The influence on the hardness was tested also under extreme practical storage conditions. The quality monitoring was performed up to one year. For the determination of the heat resistance the penetrometric method was used in the temperature range 25–32 °C measuring the maximum loading force, occurring during the penetration of a cylindrical probe of 2 mm diameter with 4 mm penetration. The correlation between the average maximum loading force, relevant to the hardness of chocolate, and the temperature can be described by a linear regression at 95% confidence level. Statistical analyses (correlation analysis, residual analysis, Durban-Watson statistic) showed that it is possible to define the heat resistance of solid chocolate in the temperature range of 25–32 °C by the slope and the ordinate intercept of the regression line of the loading force vs. temperature for given parameters (composition, storage, experimental layout, etc.). For the determination of the hardness of the chocolate also the penetrometric method was used to measure the maximum loading force occurring during the penetration of a needle probe with 2 mm deformation. The hardness of the chocolate samples determined with the penetrometric method and statistical analysis (One-Way, Two-Way Analysis of Variance, Dunnett’s comparisons) is significantly dependent on the composition and storage conditions, where the storage conditions are the dominant factor. The results show that the differences in hardness between the chocolate samples with CBE/CBI and those without CBE/CBI, both stored in the cellar (cold storage), are marginal. After one week of storage the sample with CBI has nearly the same hardness as the standard sample with CB, whereas the sample with CBE was slightly softer. The differences are slightly clearer for the northern storage room (moderate temperature) and for the southern room (warm temperature). After a definite storage time the hardness of all samples increased and was in the case of the southern storage room (warm temperature) up to twice as high. The quality monitoring up to one year showed that the reason for this increase in hardness is not a special storage time but the increasing temperatures with the beginning of the warm season and the cyclic change of the temperature during day and night. So an explanation for this unexpected increase in hardness can be a thermocyclic hardening of the chocolate samples under these storage conditions

    Inter-Procedural Static Slicing Using Advanced Caching Algorithm *

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    Since the notion of program slicing was introduced in the early 80's, the area has seen a continuous evolution. While the more recent approach of dynamic slicing gained significant interest, static slicing has also been widely studied. Original methods used dataflow analysis techniques, later different approaches using multi-graphs were formed. Although these improved algorithms offer the capability to slice real-world applications, their usability is still heavily confined by their resource intensive characteristics. In this paper an advanced caching algorithm intended to decrease average complexity of SDGbased static slicing is proposed. Caching different formal parameter set-ups of a procedure might imply significant speed growth since re-computing dependences between formal input and output parameters is avoidable

    Effect of testosterone loading on the kinetic of faecal testosterone excretion in mallards

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    Intestinal passage time of coloured fodder and testosterone turnover were examined by faecal steroid analysis in mallards in the reproductive and postrefractory period. In the latter, the discharge of coloured fodder began 36 minutes after ingestion in males, and 56 minutes in females. During reproduction the discharge began 93 minutes and 112 minutes after ingestion in males and females, respectively. Total passage time was similar in the reproductive and postrefractory period in both sexes. After intraperitoneal testosterone injection, faecal samples were collected for 8 hours and testosterone levels were measured using RIA. In the postrefractory period, 1-2 hours after testosterone loading a strong increase of faecal testosterone content developed in males, meanwhile a slighter testosterone peak appeared in females. During reproduction testosterone excretion began 1.5-2 hours after injection in both sexes but in females its increase was smaller. The duration of response to testosterone loading was 5 hours in both periods and both sexes. Intensive excretion after T loading appeared earlier in males than in females, but total passage time finished at the same time: 5 hours after loading. The character of testosterone excretion was corresponding to the passage of fodder-chimus-faeces in the reproductive and postrefractory period in both sexes
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