928 research outputs found

    Development of sampling efficiency and internal noise in motion detection and discrimination in school-aged children

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    AbstractThe aim of this study was to use an equivalent noise paradigm to investigate the development and maturation of motion perception, and how the underlying limitations of sampling efficiency and internal noise effect motion detection and direction discrimination in school-aged children (5–14years) and adults. Contrast energy thresholds of a 2c/deg sinusoidal grating drifting at 1.0 or 6.0Hz were measured as a function of added dynamic noise in three tasks: detection of a drifting grating; detection of the sum of two oppositely drifting gratings and direction discrimination of oppositely drifting gratings. Compared to the ideal observer, in both children and adults, the performance for all tasks was limited by reduced sampling efficiency and internal noise. However, the thresholds for discrimination of motion direction and detection of moving gratings show very different developmental profiles. Motion direction discrimination continues to improve after the age of 14years due to an increase in sampling efficiency that differs with speed. Motion detection and summation were already mature at the age of 5years, and internal noise was the same for all tasks. These findings were confirmed in a 1-year follow-up study on a group of children from the initial study. The results support suggestions that the detection of a moving pattern and discriminating motion direction are processed by different systems that may develop at different rates

    Injection frequency of botulinum toxin A for spastic equinus : a randomized clinical trial

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    AIM: We compared two botulinum toxin A (BoNT-A) injection frequency regimens, 12-monthly versus 4-monthly, for spastic equinus in a randomized clinical trial. The primary outcome measure was passive ankle dorsiflexion. METHOD: Forty-two ambulant children with spastic equinus, secondary to cerebral palsy (23 males and 19 females; mean age 3y 6mo, SD 13mo; GMFCS levels I [n=20], II [n=19], III [n=3]) were randomized to receive either 12-monthly or 4-monthly BoNT-A injections to the calf, over a 26-month period. Twenty-one children had spastic hemiplegia, 21 children had spastic diplegia. A fixed 6U/kg dose of Botox was injected into the gastrocnemius muscle of both limbs in children with diplegia and the gastrocsoleus of the affected limb in children with hemiplegia, under mask anaesthesia. RESULTS: Forty-two children entered the trial with 21 participants randomized to each group. There were three withdrawals and two children received serial casting midway through the trial. There was no significant difference in passive dorsiflexion between 12-monthly and 4-monthly regimens (p=0.41). There were also no significant between group differences on secondary outcome measures. There were no serious adverse events - the rate was 1.2 adverse events per child per year in the 12-monthly group and 2.2 adverse events per child per year in the 4-monthly group. Subgroup analysis revealed a significant difference in passive dorsiflexion between children with hemiplegia and diplegia (p=0.01). INTERPRETATION: There was no significant difference between 12-monthly and 4-monthly injection regimens on passive dorsiflexion or secondary outcome measures. BoNT-A injections for spastic equinus may be recommended on a 12-monthly basis

    Triggers of Breathlessness in Inducible Laryngeal Obstruction and Asthma

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    BackgroundInducible laryngeal obstruction (ILO) is often misdiagnosed as, or may coexist with, asthma. Identifying differences in triggering factors may assist clinicians to differentiate between the two conditions, and could give mechanistic insights.ObjectiveTo identify and compare patient‐reported triggers in ILO and asthma.MethodsThis was a two‐part study. Initially we conducted a retrospective case note review of the triggers of ILO from endoscopically‐confirmed ILO patients to generate a Breathlessness Triggers Survey (BrTS). Triggers were categorised as: scents, environmental factors, temperature, emotions, mechanical factors and daily activities. Secondly, ILO and/or asthma patients completed the BrTS prospectively, rating the likelihood of each item triggering their symptoms using a five‐point Likert scale (strongly disagree to strongly agree). Chi‐square testing was performed to compare responses by cohort.ResultsData from 202 patients with ILO [73% female, mean (SD) age 53(16) years] were included in the case note review. For the prospective study, 38 patients with ILO‐only [63% females, age 57(16) years], 39 patients with asthma‐only [(56% female, age 53(13) years] and 12 patients with both ILO and asthma [83% female, mean age, 57 (14) years)] completed the BrTS. The triggers identified in the case note review were confirmed in the independent sample of patients with ILO and/or asthma and identified several difference in prevalence of the triggers between disease types. Mechanical factors [talking (

    Associations between lifestyle behaviors and quality of life differ based on multiple sclerosis phenotype

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    Multiple sclerosis (MS), a neuroinflammatory disorder, occurs as non-progressive or progressive phenotypes; both forms present with diverse symptoms that may reduce quality of life (QoL). Adherence to healthy lifestyle behaviors has been associated with higher QoL in people with MS; whether these associations differ based on MS phenotype is unknown. Cross-sectional self-reported observational data from 1108 iConquerMS participants were analysed. Associations between lifestyle behaviors and QoL were assessed by linear regression, and phenotype differences via moderation analyses. Diet, wellness, and physical activity, but not vitamin D or omega-3 supplement use, were associated with QoL. Specifically, certain diet types were negatively associated with QoL in relapsing-remitting MS (RRMS), and positively associated in progressive MS (ProgMS). Participation in wellness activities had mixed associations with QoL in RRMS but was not associated in ProgMS. Physical activity was positively associated with QoL in RRMS and ProgMS. Phenotype differences were observed in diet and wellness with physical QoL, and physical activity with most QoL subdomains. Our findings show lifestyle behaviors are associated with QoL and appear to differ based on MS phenotype. Future studies assessing timing, duration, and adherence of adopting lifestyle behaviors may better inform their role in MS management

    A genetic programming based fuzzy regression approach to modelling manufacturing processes

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    Fuzzy regression has demonstrated its ability to model manufacturing processes in which the processes have fuzziness and the number of experimental data sets for modelling them is limited. However, previous studies only yield fuzzy linear regression based process models in which variables or higher order terms are not addressed. In fact, it is widely recognised that behaviours of manufacturing processes do often carry interactions among variables or higher order terms. In this paper, a genetic programming based fuzzy regression GP-FR, is proposed for modelling manufacturing processes. The proposed method uses the general outcome of GP to construct models the structure of which is based on a tree representation, which could carry interaction and higher order terms. Then, a fuzzy linear regression algorithm is used to estimate the contributions and the fuzziness of each branch of the tree, so as to determine the fuzzy parameters of the genetic programming based fuzzy regression model.To evaluate the effectiveness of the proposed method for process modelling, it was applied to the modelling of a solder paste dispensing process. Results were compared with those based on statistical regression and fuzzy linear regression. It was found that the proposed method can achieve better goodness-of-fitness than the other two methods. Also the prediction accuracy of the model developed based on GP-FR is better than those based on the other two methods

    Improved annotation of 3' untranslated regions and complex loci by combination of strand-specific direct RNA sequencing, RNA-seq and ESTs

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    The reference annotations made for a genome sequence provide the framework for all subsequent analyses of the genome. Correct annotation is particularly important when interpreting the results of RNA-seq experiments where short sequence reads are mapped against the genome and assigned to genes according to the annotation. Inconsistencies in annotations between the reference and the experimental system can lead to incorrect interpretation of the effect on RNA expression of an experimental treatment or mutation in the system under study. Until recently, the genome-wide annotation of 3-prime untranslated regions received less attention than coding regions and the delineation of intron/exon boundaries. In this paper, data produced for samples in Human, Chicken and A. thaliana by the novel single-molecule, strand-specific, Direct RNA Sequencing technology from Helicos Biosciences which locates 3-prime polyadenylation sites to within +/- 2 nt, were combined with archival EST and RNA-Seq data. Nine examples are illustrated where this combination of data allowed: (1) gene and 3-prime UTR re-annotation (including extension of one 3-prime UTR by 5.9 kb); (2) disentangling of gene expression in complex regions; (3) clearer interpretation of small RNA expression and (4) identification of novel genes. While the specific examples displayed here may become obsolete as genome sequences and their annotations are refined, the principles laid out in this paper will be of general use both to those annotating genomes and those seeking to interpret existing publically available annotations in the context of their own experimental dataComment: 44 pages, 9 figure

    Predicting the Impact of Climate Change on Threatened Species in UK Waters

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    Global climate change is affecting the distribution of marine species and is thought to represent a threat to biodiversity. Previous studies project expansion of species range for some species and local extinction elsewhere under climate change. Such range shifts raise concern for species whose long-term persistence is already threatened by other human disturbances such as fishing. However, few studies have attempted to assess the effects of future climate change on threatened vertebrate marine species using a multi-model approach. There has also been a recent surge of interest in climate change impacts on protected areas. This study applies three species distribution models and two sets of climate model projections to explore the potential impacts of climate change on marine species by 2050. A set of species in the North Sea, including seven threatened and ten major commercial species were used as a case study. Changes in habitat suitability in selected candidate protected areas around the UK under future climatic scenarios were assessed for these species. Moreover, change in the degree of overlap between commercial and threatened species ranges was calculated as a proxy of the potential threat posed by overfishing through bycatch. The ensemble projections suggest northward shifts in species at an average rate of 27 km per decade, resulting in small average changes in range overlap between threatened and commercially exploited species. Furthermore, the adverse consequences of climate change on the habitat suitability of protected areas were projected to be small. Although the models show large variation in the predicted consequences of climate change, the multi-model approach helps identify the potential risk of increased exposure to human stressors of critically endangered species such as common skate (Dipturus batis) and angelshark (Squatina squatina)

    Integration of Data Mining Classification Techniques and Ensemble Learning for Predicting the Type of Breast Cancer Recurrence

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    Conservative surgery plus radiotherapy is an alternative to radical mastectomy in the early stages of breast cancer, presenting equivalent survival rates. Data mining facilitates to manage the data and provide the useful medical progression and treatment of cancerous conditions as these methods can help to reduce the number of false positive and false negative decisions. Various machine learning techniques can be used to support the doctors in effective and accurate decision making. In this paper, various classifiers have been tested for the prediction of type of breast cancer recurrence and the results show that neural networks outperform others
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