3,162 research outputs found

    Dynamical analysis of the interaction between object location and hand use in a midline crossing task in children with trisomy 21

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    Objective: The aim of the study was to analyze the influence of spatial constraints on the hand use in children with trisomy 21. Methods: Participants were 31 children with trisomy (13.35 ± 2.78 years old, 18 girls) (T21) and 38 children with typical development (8.62±.79 years old, 22 girls) (TD), with similar APGAR scores at birth (1 mn and 5 mn), but with significantly different mental age in Goodenough test. Children grasped seven colored Styrofoam balls in a semi-circumference arraying; in a pseudorandom condition (R) and in a scaling condition (increasing sequence [IS]- from left to right hemispace; decreasing sequence [DS]- from right to left hemispace). Results: In the R, TD displayed a significantly greater frequency of midline crossing than T21, as in the DS; but not in the IS condition. T21 showed significantly larger hysteresis in the left hemispace, as well as in the midline location, but not in the right hemispace. In R, IS and DS, no significant differences were observed between TD and T21 in the frequency of left-hand use. Conclusion: Spatial constraints highly determined T21 hand-use, as clearly expressed in the pattern of midline crossing and of hysteresis. In T21, the scaling procedure permitted the detection of patterns of interaction among spatial and intrinsic constraints, that the traditional R procedure would not. This perceptual-motor pattern of behavior should be considered as criteria in the planning of perceptual-motor intervention for children with T21. We propose the “task constraints attunement hypothesis”, suggesting that T21 children (and, probably others with developmental problems) reveal more left-handedness and less asymmetry because they are compelled to use the hand in accordance with spatial constraints.info:eu-repo/semantics/publishedVersio

    Molecular Diagnostics in the Mycosphaerella Leaf Spot Disease Complex of Banana and for Radopholus similis

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    Mycosphaerella leaf spots and nematodes threaten banana cultivation worldwide. The Mycosphaerella disease complex involves three related ascomycetous fungi: Mycosphaerella fijiensis, M. musicola and M. eumusae. The exact distribution of these three species and their disease epidemiology remain unclear, since their symptoms and life cycles are rather similar. Diagnosing these diseases and the respective causal agents is based on the presence of host symptoms and fungal fruiting structures, but is time consuming and not conducive to preventive management. In the present study, we developed rapid and robust species-specific diagnostic tools to detect and quantify M. fijiensis, M. musicola and M. eumusae. Conventional species-specific PCR primers were developed based on the actin gene that detected as little as 100, 1 and 10 pg/µl DNA from, respectively, M. fijiensis, M. musicola and M. eumusae. Furthermore, TaqMan real-time quantitative PCR assays that were developed based on the ß-tubulin gene detected quantities as low as 1 pg/µl DNA of each species from pure cultures and 1.6 pg/µl DNA/mg of M. fijiensis from dry leaf tissue. The efficacy of the tests was validated using naturally infected banana leaves. Similar technology has been used to develop a quantitative PCR assay for the banana burrowing nematode, Radopholus similis, which is currently being validate

    Revisiting the microtubule based quantum models of mind: tubulin bound GTP cannot pump microtubule coherence or provide energy for alpha <-> beta computation in stable microtubules

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    The current paper investigates the biological models of stable brain microtubules as quantum or classical computers whose function is based on electron hopping associated with kinking of the tubulin dimer. Hameroff (1998a, 1998b, 2003a, 2003b), Tuszynski et al. (1998), Hagan et al. (2000), Mershin et al. (1999); Mershin (2003) suppose that the energy needed could be somehow delivered via guanosine diphosphate (GDP) exchange for guanosine triphosphate (GTP) or via cycles of tubulin bound GTP hydrolysis. Here is presented biological and structural data from electron diffraction studies performed by Lowe et al. (2001) and computer simulation with MDL ® Chime Version 2.6 SP4, explaining and visualizing the inconsistency of the proposed tubulin bit (qubit) GTP energized alpha <-> beta computation and/or tubulin bound GTP pumped coherence in stable microtubules

    Identifying patients at risk for augmented renal clearance in the ICU : limitations and challenges

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    Augmented renal clearance (ARC) is an important determinant of antibiotic exposure in critically ill patients, and identifying patients at risk is therefore an important goal. There is a growing body of evidence that a younger patient with a low to moderate degree of organ dysfunction typically is at risk of ARC and therefore decreased exposure to renally eliminated antibiotics. Mechanisms potentially involved, such as increased cardiac output, have, however, not been identified as appropriate surrogate markers, and the search for suitable alternatives to readily identify patients with ARC continues

    Experimental and modeling study of the autoignition of 1-hexene/iso-octane mixtures at low temperatures

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    Autoignition delay times have been measured in a rapid compression machine at Lille at temperatures after compression from 630 to 840 K, pressures from 8 to 14 bar, \Phi = 1 and for a iso octane/1 hexene mixture containing 82% iso-octane and 18% 1 hexene. Results have shown that this mixture is strongly more reactive than pure iso-octane, but less reactive than pure 1 hexene. It exhibits a classical low temperature behaviour, with the appearance of cool flame and a negative temperature coefficient region. The composition of the reactive mixture obtained after the cool flame has also been determined. A detailed kinetic model has been obtained by using the system EXGAS, developed in Nancy for the automatic generation of kinetic mechanisms, and an acceptable agreement with the experimental results has been obtained both for autoignition delay times and for the distribution of products. A flow rate analysis reveals that the crossed reactions between species coming from both reactants (like H-abstractions or combinations) are negligible in the main flow consumption of the studied hydrocarbons. The ways of formation of the main primary products observed and the most sensitive rate constants have been identified

    The Experience of Traumatic Stress among Urban Firefighters

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    Findings provide evidence that it is possible for emergency responders to become ‘locked into’ a regular cycle of trauma exposure that includes rapid returns to operationally ready status (i.e. being made available for another turnout immediately, or soon after returning from a previous emergency situation). Without the opportunity to interrupt the emotional reaction of an earlier traumatic response, a downward spiral of inescapable stress response may be instigated and with ongoing exposure. This paper details evidence suggesting the existence of a relationship between the work tasks of the fire fighters and a propensity for certain physiological responses and stress reactions noted during on-the-job research. Sensitivity to such processes may be gradually built up among emergency responders as their career progresses. The work suggests that in addition to instances of critical incident stress, that could be expected among emergency workers, the turn-out mechanism used actually pre-disposes the fire fighters to ongoing traumatic responses

    Validacija i procjena mjerne nesigurnosti u mikrobiologiji hrane: razlika između kvantitativnih i kvalitativnih metoda

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    The aim of this research is to describe quality control procedures, procedures for validation and measurement uncertainty (MU) determination as an important element of quality assurance in food microbiology laboratory for qualitative and quantitative type of analysis. Accreditation is conducted according to the standard ISO 17025:2007. General requirements for the competence of testing and calibration laboratories, which guarantees the compliance with standard operating procedures and the technical competence of the staff involved in the tests, recently are widely introduced in food microbiology laboratories in Croatia. In addition to quality manual introduction, and a lot of general documents, some of the most demanding procedures in routine microbiology laboratories are measurement uncertainty (MU) procedures and validation experiment design establishment. Those procedures are not standardized yet even at international level, and they require practical microbiological knowledge, altogether with statistical competence. Differences between validation experiments design for quantitative and qualitative food microbiology analysis are discussed in this research, and practical solutions are shortly described. MU for quantitative determinations is more demanding issue than qualitative MU calculation. MU calculations are based on external proficiency testing data and internal validation data. In this paper, practical schematic descriptions for both procedures are shown.Cilj ovog rada je opisati postupke kontrole kvalitete te postupke validacije i određivanja mjerne nesigurnosti koji su važan element u osiguranju kvalitete rada laboratorija za mikrobiologiju namirnica, za kvalitativne kao i za kvantitativne metode određivanja. Akreditacija prema normi HRN EN ISO/ IEC 17025:2007. Opći zahtjevi za osposobljenost ispitnih i umjernih laboratorija, koja jamči poštivanje standardnih operativnih postupaka i tehničku kompetentnost osoblja koje je uključeno u provođenje ovakvih ispitivanja, u posljednje vrijeme se na velika vrata uvodi u sve veći broj laboratorija za mikrobiologiju hrane u Hrvatskoj. Osim izrade priručnika kvalitete, te niza opće dokumentacije, jedna od najzahtjevnijih zadaća za rutinske mikrobiološke laboratorije prema zahtjevu HRN EN ISO/IEC 17025:2007 je izrada postupaka validacije i mjerne nesigurnosti (MU) ispitnih metoda. Ti postupci nisu još uvijek standardizirani ni na međunarodnoj razini, stoga je potrebno mnogo praktičnog mikrobiološkog znanja, ali i statističkih kompetencija za uspostavu ovih postupaka. Postoji razlika između provjere valjanosti kvantitativnih i kvalitativnih mikrobioloških metoda analize hrane i u ovom radu su one obrađene te opisana njihova praktična rješenja. Određivanje mjerne nesigurnosti kod kvantitativnih analiza zahtjevnije je nego kod kvalitativnih analiza. Kod kvantitativnih mikrobioloških metoda za proračun MU koriste se pojmovi ponovljivost (r) i reproducibilnost (R) upravo iz validacijskih postupaka. Kod kvalitativnih mikrobioloških analiza uobičajene mjere r i R su neprimjenjive. Analiza se temelji na vjerojatnosti pronalaženja istog rezultata u identičnom test materijalu (uzorku) unutar i između laboratorija. Dakle, izračun MU temelji se na podacima interkalibracije i internim provjerama valjanosti podataka. U ovom radu prikazan je shematski prikaz za oba postupaka određivanja
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