316 research outputs found

    WearCam: A head mounted wireless camera for monitoring gaze attention and for the diagnosis of developmental disorders in young children

    Get PDF
    Autism covers a large spectrum of disorders that affect the individual’s way of interacting socially and is often revealed by the individual’s lack of interest in gazing at human faces. Currently Autism is diagnosed in children no younger than 2 years old. This paper presents a new monitoring device, the WearCam, to help forming a diagnosis of this neurodevelopmental disorder at an earlier age than currently possible. The WearCam consists of a wireless camera located on the forefront of the child. The WearCam collects videos from the viewpoint of the child’s head. Color detection, face detection and gaze detection are run on the data in order to locate the approximate gaze direction of the child and determine where her attention is drawn to (persons, objects, etc.). We report on early tests of the camera within normally developing children. Firstly the technical characteristics of the current prototype of the WearCam will be described. Afterwards the type of data collected with this device with young children will be shown

    Molecular Cloning and Expression Analysis of fushi tarazu Factor 1 in the Brain of Air-Breathing Catfish, Clarias gariepinus

    Get PDF
    BACKGROUND: Fushi tarazu factor 1 (FTZ-F1) encodes an orphan nuclear receptor belonging to the nuclear receptor family 5A (NR5A) which includes adrenal 4-binding protein or steroidogenic factor-1 (Ad4BP/SF-1) and liver receptor homologue 1 (LRH-1) and plays a pivotal role in the regulation of aromatases. METHODOLOGY/PRINCIPAL FINDINGS: Present study was aimed to understand the importance of FTZ-F1 in relation to brain aromatase (cyp19a1b) during development, recrudescence and after human chorionic gonadotropin (hCG) induction. Initially, we cloned FTZ-F1 from the brain of air-breathing catfish, Clarias gariepinus through degenerate primer RT-PCR and RACE. Its sequence analysis revealed high homology with other NR5A1 group members Ad4BP/SF-1 and LRH-1, and also analogous to the spatial expression pattern of the latter. In order to draw functional correlation of cyp19a1b and FTZ-F1, we analyzed the expression pattern of the latter in brain during gonadal ontogeny, which revealed early expression during gonadal differentiation. The tissue distribution both at transcript and protein levels revealed its prominent expression in brain along with liver, kidney and testis. The expression pattern of brain FTZ-F1 during reproductive cycle and after hCG induction, in vivo was analogous to that of cyp19a1b shown in our earlier study indicating its involvement in recrudescence. CONCLUSIONS/SIGNIFICANCE: Based on our previous results on cyp19a1b and the present data, it is plausible to implicate potential roles for brain FTZ-F1 in ovarian differentiation and recrudescence process probably through regulation of cyp19a1b in teleosts. Nevertheless, these interactions would require primary coordinated response from ovarian aromatase and its related transcription factors

    Index finger movement imitation by human neonates: motivation, learning, and left-hand preference

    Get PDF
    Imitation of a fine motor movement, index finger protrusion, was examined in 39 neonates using an ethologically based objective coding system. Results confirmed that imitation of finger movements exists, and infants demonstrated "learning" as imitation developed through an incomplete imitation stage. Neonatal imitation was more frequently left-handed, an early sign of laterality in motivation to be investigated further. The existence of index finger imitation in human neonates indicates that volitional control of individuated finger movements develops much earlier than previously thought. The differential increase of index finger protrusion movements during the imitation periods suggests that this behavior is not an automatic response triggered by general arousal but instead is a true indicator of purposeful neonatal imitation

    Nonlinear Fitness Landscape of a Molecular Pathway

    Get PDF
    Genes are regulated because their expression involves a fitness cost to the organism. The production of proteins by transcription and translation is a well-known cost factor, but the enzymatic activity of the proteins produced can also reduce fitness, depending on the internal state and the environment of the cell. Here, we map the fitness costs of a key metabolic network, the lactose utilization pathway in Escherichia coli. We measure the growth of several regulatory lac operon mutants in different environments inducing expression of the lac genes. We find a strikingly nonlinear fitness landscape, which depends on the production rate and on the activity rate of the lac proteins. A simple fitness model of the lac pathway, based on elementary biophysical processes, predicts the growth rate of all observed strains. The nonlinearity of fitness is explained by a feedback loop: production and activity of the lac proteins reduce growth, but growth also affects the density of these molecules. This nonlinearity has important consequences for molecular function and evolution. It generates a cliff in the fitness landscape, beyond which populations cannot maintain growth. In viable populations, there is an expression barrier of the lac genes, which cannot be exceeded in any stationary growth process. Furthermore, the nonlinearity determines how the fitness of operon mutants depends on the inducer environment. We argue that fitness nonlinearities, expression barriers, and gene–environment interactions are generic features of fitness landscapes for metabolic pathways, and we discuss their implications for the evolution of regulation

    Kinetics of biodegradation of diethylketone by Arthrobacter viscosus

    Get PDF
    The performance of an Arthrobacter viscosus culture to remove diethylketone from aqueous solutions was evaluated. The effect of initial concentration of diethylketone on the growth of the bacteria was evaluated for the range of concentration between 0 and 4.8 g/l, aiming to evaluate a possible toxicological effect. The maximum specific growth rate achieved is 0.221 h-1 at 1.6 g/l of initial diethylketone concentration, suggesting that for higher concentrations an inhibitory effect on the growth occurs. The removal percentages obtained were approximately 88%, for all the initial concentrations tested. The kinetic parameters were estimated using four growth kinetic models for biodegradation of organic compounds available in the literature. The experimental data found is well fitted by the Haldane model (R2 = 1) as compared to Monod model (R2 = 0.99), Powell (R2 = 0.82) and Loung model (R2 = 0.95). The biodegradation of diethylketone using concentrated biomass was studied for an initial diethylketone concentration ranging from 0.8–3.9 g/l in a batch with recirculation mode of operation. The biodegradation rate found followed the pseudo-second order kinetics and the resulting kinetic parameters are reported. The removal percentages obtained were approximately 100%, for all the initial concentrations tested, suggesting that the increment on the biomass concentration allows better results in terms of removal of diethylketone. This study showed that these bacteria are very effective for the removal of diethylketone from aqueous solutions.The authors would like to gratefully acknowledge the financial support of this project by the Fundacao para a Ciencia e Tecnologia (FCT), Ministerio da Ciencia e Tecnologia, Portugal and Fundo Social Europeu (FSE). Cristina Quintelas thanks FCT for a Post-Doc grant

    The relationship between a child's postural stability and manual dexterity

    Get PDF
    The neural systems responsible for postural control are separate from the neural substrates that underpin control of the hand. Nonetheless, postural control and eye-hand coordination are linked functionally. For example, a stable platform is required for precise manual control tasks (e.g. handwriting) and thus such skills often cannot develop until the child is able to sit or stand upright. This raises the question of the strength of the empirical relationship between measures of postural stability and manual motor control. We recorded objective computerised measures of postural stability in stance and manual control in sitting in a sample of school children (n = 278) aged 3–11 years in order to explore the extent to which measures of manual skill could be predicted by measures of postural stability. A strong correlation was found across the whole sample between separate measures of postural stability and manual control taken on different days. Following correction for age, a significant but modest correlation was found. Regression analysis with age correction revealed that postural stability accounted for between 1 and 10 % of the variance in manual performance, dependent on the specific manual task. These data reflect an interdependent functional relationship between manual control and postural stability development. Nevertheless, the relatively small proportion of the explained variance is consistent with the anatomically distinct neural architecture that exists for ‘gross’ and ‘fine’ motor control. These data justify the approach of motor batteries that provide separate assessments of postural stability and manual dexterity and have implications for therapeutic intervention in developmental disorders

    What Affects Social Attention? Social Presence, Eye Contact and Autistic Traits

    Get PDF
    Social understanding is facilitated by effectively attending to other people and the subtle social cues they generate. In order to more fully appreciate the nature of social attention and what drives people to attend to social aspects of the world, one must investigate the factors that influence social attention. This is especially important when attempting to create models of disordered social attention, e.g. a model of social attention in autism. Here we analysed participants' viewing behaviour during one-to-one social interactions with an experimenter. Interactions were conducted either live or via video (social presence manipulation). The participant was asked and then required to answer questions. Experimenter eye-contact was either direct or averted. Additionally, the influence of participant self-reported autistic traits was also investigated. We found that regardless of whether the interaction was conducted live or via a video, participants frequently looked at the experimenter's face, and they did this more often when being asked a question than when answering. Critical differences in social attention between the live and video interactions were also observed. Modifications of experimenter eye contact influenced participants' eye movements in the live interaction only; and increased autistic traits were associated with less looking at the experimenter for video interactions only. We conclude that analysing patterns of eye-movements in response to strictly controlled video stimuli and natural real-world stimuli furthers the field's understanding of the factors that influence social attention

    Antimicrobial peptides of the Cecropin-family show potent antitumor activity against bladder cancer cells

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>This study evaluated the cytotoxic and antiproliferative efficacy of two well-characterized members of the Cecropin-family of antimicrobial peptides against bladder tumor cells and benign fibroblasts.</p> <p>Methods</p> <p>The antiproliferative and cytotoxic potential of the Cecropins A and B was quantified by colorimetric WST-1-, BrdU- and LDH-assays in four bladder cancer cell lines as well as in murine and human fibroblast cell lines. IC<sub>50 </sub>values were assessed by logarithmic extrapolation, representing the concentration at which cell viability was reduced by 50%. Scanning electron microscopy (SEM) was performed to visualize the morphological changes induced by Cecropin A and B in bladder tumor cells and fibroblasts.</p> <p>Results</p> <p>Cecropin A and B inhibit bladder cancer cell proliferation and viability in a dose-dependent fashion. The average IC<sub>50 </sub>values of Cecropin A and B against all bladder cancer cell lines ranged between 73.29 μg/ml and 220.05 μg/ml. In contrast, benign fibroblasts were significantly less or not at all susceptible to Cecropin A and B. Both Cecropins induced an increase in LDH release from bladder tumor cells whereas benign fibroblasts were not affected. SEM demonstrated lethal membrane disruption in bladder cancer cells as opposed to fibroblasts.</p> <p>Conclusion</p> <p>Cecropin A and B exert selective cytotoxic and antiproliferative efficacy in bladder cancer cells while sparing targets of benign murine or human fibroblast origin. Both peptides may offer novel therapeutic strategies for the treatment of bladder cancer with limited cytotoxic effects on benign cells.</p

    Expression profiles for six zebrafish genes during gonadal sex differentiation

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The mechanism of sex determination in zebrafish is largely unknown and neither sex chromosomes nor a sex-determining gene have been identified. This indicates that sex determination in zebrafish is mediated by genetic signals from autosomal genes. The aim of this study was to determine the precise timing of expression of six genes previously suggested to be associated with sex differentiation in zebrafish. The current study investigates the expression of all six genes in the same individual fish with extensive sampling dates during sex determination and -differentiation.</p> <p>Results</p> <p>In the present study, we have used quantitative real-time PCR to investigate the expression of ar, sox9a, dmrt1, fig alpha, cyp19a1a and cyp19a1b during the expected sex determination and gonadal sex differentiation period. The expression of the genes expected to be high in males (ar, sox9a and dmrt1a) and high in females (fig alpha and cyp19a1a) was segregated in two groups with more than 10 times difference in expression levels. All of the investigated genes showed peaks in expression levels during the time of sex determination and gonadal sex differentiation. Expression of all genes was investigated on cDNA from the same fish allowing comparison of the high and low expressers of genes that are expected to be highest expressed in either males or females. There were 78% high or low expressers of all three "male" genes (ar, sox9a and dmrt1) in the investigated period and 81% were high or low expressers of both "female" genes (fig alpha and cyp19a1a). When comparing all five genes with expected sex related expression 56% show expression expected for either male or female. Furthermore, the expression of all genes was investigated in different tissue of adult male and female zebrafish.</p> <p>Conclusion</p> <p>In zebrafish, the first significant peak in gene expression during the investigated period (2–40 dph) was dmrt1 at 10 dph which indicates involvement of this gene in the early gonadal sex differentiation of males.</p

    Training compliance control yields improvements in drawing as a function of beery scores

    Get PDF
    Many children have difficulty producing movements well enough to improve in sensori-motor learning. Previously, we developed a training method that supports active movement generation to allow improvement at a 3D tracing task requiring good compliance control. Here, we tested 7–8 year old children from several 2nd grade classrooms to determine whether 3D tracing performance could be predicted using the Beery VMI. We also examined whether 3D tracing training lead to improvements in drawing. Baseline testing included Beery, a drawing task on a tablet computer, and 3D tracing. We found that baseline performance in 3D tracing and drawing co-varied with the visual perception (VP) component of the Beery. Differences in 3D tracing between children scoring low versus high on the Beery VP replicated differences previously found between children with and without motor impairments, as did post-training performance that eliminated these differences. Drawing improved as a result of training in the 3D tracing task. The training method improved drawing and reduced differences predicted by Beery scores
    corecore