117 research outputs found

    MathLex: A Web-Based Mathematical Entry System

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    Mathematical formulas are easy to convey in handwritten media, but how should they be represented in electronic format? Unfortunately, mathematical content has not been as well-implemented on the Web as images and video. There are two sides to this problem: display and input. The former has been solved in multiple ways by representing formulas as images, MathML, or LaTeX (via MathJax). Representing math input is much more difficult and is the subject of this thesis. The goal is to enable users to enter complex formulas. Unfortunately, existing languages either are too complex for an average user (difficult to learn and/or read), only work in a particular environment (they have system and browser compatibility issues), or lack certain math concepts. Some do not even retain mathematical meaning. This thesis presents MathLex, an intuitive, easy-to-type, unambiguous, mathematically faithful input language and processing system intended for representing math input (and potentially display) on the web. It aims to mimic handwritten math as much as possible while maintaining semantic meaning

    The Fuzziness in Molecular, Supramolecular, and Systems Chemistry

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    Fuzzy Logic is a good model for the human ability to compute words. It is based on the theory of fuzzy set. A fuzzy set is different from a classical set because it breaks the Law of the Excluded Middle. In fact, an item may belong to a fuzzy set and its complement at the same time and with the same or different degree of membership. The degree of membership of an item in a fuzzy set can be any real number included between 0 and 1. This property enables us to deal with all those statements of which truths are a matter of degree. Fuzzy logic plays a relevant role in the field of Artificial Intelligence because it enables decision-making in complex situations, where there are many intertwined variables involved. Traditionally, fuzzy logic is implemented through software on a computer or, even better, through analog electronic circuits. Recently, the idea of using molecules and chemical reactions to process fuzzy logic has been promoted. In fact, the molecular word is fuzzy in its essence. The overlapping of quantum states, on the one hand, and the conformational heterogeneity of large molecules, on the other, enable context-specific functions to emerge in response to changing environmental conditions. Moreover, analog input–output relationships, involving not only electrical but also other physical and chemical variables can be exploited to build fuzzy logic systems. The development of “fuzzy chemical systems” is tracing a new path in the field of artificial intelligence. This new path shows that artificially intelligent systems can be implemented not only through software and electronic circuits but also through solutions of properly chosen chemical compounds. The design of chemical artificial intelligent systems and chemical robots promises to have a significant impact on science, medicine, economy, security, and wellbeing. Therefore, it is my great pleasure to announce a Special Issue of Molecules entitled “The Fuzziness in Molecular, Supramolecular, and Systems Chemistry.” All researchers who experience the Fuzziness of the molecular world or use Fuzzy logic to understand Chemical Complex Systems will be interested in this book

    Development of biofluid biomarkers for Huntington’s disease

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    Though no treatments can currently prevent onset or slow progression of Huntington’s disease (HD), many huntingtin-lowering drug candidates targeting the root cause of HD are in the development pipeline. This brings much hope that disease-modifying treatments for HD will be a reality. However, success of potential candidates may be hindered by a lack of sensitive tools to measure biological efficacy over short intervals. Decades of attempts to develop robust biofluid biomarkers of HD progression has yielded little success or replication of results. Cerebrospinal fluid (CSF), fluid that bathes the brain and is enriched for brain-specific proteins, is a plausible target for uncovering neuropathologically relevant markers of HD. However, a lack of standardisation of collection protocols, biological rationale and technological sensitivity has hampered the progress of CSF biomarkers within the field of HD. At the core of this thesis lies the HD-CSF study – a single-site CSF collection study, with a standardised protocol designed to generate high-quality CSF and blood with matched clinical and phenotypic data. It is the first CSF collection prospectively designed for longitudinal sampling and having matching MRI data. Mutant huntingtin protein (mHTT) can be quantified in CSF and has been identified as having high potential as a biomarker of HD progression. Further, the interpretation of drug-induced lowering of mHTT in the CNS relies upon elucidation of the natural history of CSF mHTT in HD gene carriers. Neurofilament light (NfL) has emerged as a promising marker of neuronal damage that can be measured in CSF and blood. This thesis includes the first reports of blood NfL in HD, head to head comparison of NfL and mHTT, and assessment of longitudinal alterations in mHTT and NfL, in addition to proposed biomarkers of specific pathogenic pathways. The work in this thesis will have significant implications for the use of NfL and mHTT as pharmacodynamic markers of HD

    Sox10 regulates enteric neural crest cell migration in the developing gut

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    Concurrent Sessions 1: 1.3 - Organs to organisms: Models of Human Diseases: abstract no. 1417th ISDB 2013 cum 72nd Annual Meeting of the Society for Developmental Biology, VII Latin American Society of Developmental Biology Meeting and XI Congreso de la Sociedad Mexicana de Biologia del Desarrollo. The Conference's web site is located at http://www.inb.unam.mx/isdb/Sox10 is a HMG-domain containing transcription factor which plays important roles in neural crest cell survival and differentiation. Mutations of Sox10 have been identified in patients with Waardenburg-Hirschsprung syndrome, who suffer from deafness, pigmentation defects and intestinal aganglionosis. Enteric neural crest cells (ENCCs) with Sox10 mutation undergo premature differentiation and fail to colonize the distal hindgut. It is unclear, however, whether Sox10 plays a role in the migration of ENCCs. To visualize the migration behaviour of mutant ENCCs, we generated a Sox10NGFP mouse model where EGFP is fused to the N-terminal domain of Sox10. Using time-lapse imaging, we found that ENCCs in Sox10NGFP/+ mutants displays lower migration speed and altered trajectories compared to normal controls. This behaviour was cell-autonomous, as shown by organotypic grafting of Sox10NGFP/+ gut segments onto control guts and vice versa. ENCCs encounter different extracellular matrix (ECM) molecules along the developing gut. We performed gut explant culture on various ECM and found that Sox10NGFP/+ ENCCs tend to form aggregates, particularly on fibronectin. Time-lapse imaging of single cells in gut explant culture indicated that the tightly-packed Sox10 mutant cells failed to exhibit contact inhibition of locomotion. We determined the expression of adhesion molecule families by qPCR analysis, and found integrin expression unaffected while L1-cam and selected cadherins were altered, suggesting that Sox10 mutation affects cell adhesion properties of ENCCs. Our findings identify a de novo role of Sox10 in regulating the migration behaviour of ENCCs, which has important implications for the treatment of Hirschsprung disease.postprin

    Engineering data compendium. Human perception and performance. User's guide

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    The concept underlying the Engineering Data Compendium was the product of a research and development program (Integrated Perceptual Information for Designers project) aimed at facilitating the application of basic research findings in human performance to the design and military crew systems. The principal objective was to develop a workable strategy for: (1) identifying and distilling information of potential value to system design from the existing research literature, and (2) presenting this technical information in a way that would aid its accessibility, interpretability, and applicability by systems designers. The present four volumes of the Engineering Data Compendium represent the first implementation of this strategy. This is the first volume, the User's Guide, containing a description of the program and instructions for its use

    Complex genetic approaches to neurodegenerative diseases.

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    Neurodegenerative diseases are fatal disorders in which disease pathogenesis results in the progressive degeneration of the central and/or the peripheral nervous systems. These diseases currently affect -2% of the population but are expected to increase in prevalence as average life expectancy increases. The majority of these diseases have a complex genetic basis. The work presented in this thesis aimed to investigate the genetic basis of two neurodegenerative diseases, amyotrophic lateral sclerosis (ALS) and the human prion diseases kuru and sporadic Creutzfeldt-Jakob disease (sCJD), using novel complex genetic approaches. ALS is a fatal neurodegenerative disease in which motor neurons are seen to degenerate. It is a complex disease with 10% of individuals having a family history and the remaining 90% of non-familial cases having some genetic component. The gene DYNC1H1 is involved in retrograde axonal transport and is a good candidate for ALS. In this thesis the genetic architecture of DYNC1H1 was elucidated and a mutation screen of exons 8, 13 and 14 was undertaken in familial forms of ALS and other motor neuron diseases. No mutations were found. A linkage disequilibrium (LD) based association study was conducted using two tagging single nucleotide polymorphisms (tSNPs) which were identified as sufficient to represent genetic variation across DYNC1HI. These tSNPs were tested for an association with sporadic ALS (SALS) in 261 cases and 225 matched controls but no association was identified. Kuru is a devastating epidemic prion disease which affected a highly geographically restricted area of the Papua New Guinea highlands, predominantly affected adult women and children. Its incidence has steadily declined since the cessation of its route of transmission, endocannibalism, in the late 1950's. Kuru imposed strong balancing selection on codon 129 of the prion gene (PRNP). Analysis of kuru-exposed and unexposed populations showed significant deviations from Hardy-Weinberg equilibrium (HWE) consistent with the known protective effect of codon 129 heterozygosity. Signatures of selection were investigated in the surviving populations, such as deviations from HWE and an increasing cline in codon 129 valine allele frequency, which covaried with disease exposure. A novel PRNP G127V polymorphism was detected which, while common in the area of highest kuru incidence, was absent from kuru patients and unexposed population groups. Genealogical analysis revealed that the heterozygous PRNP G127V genotype confers strong prion disease resistance, which has been selected by the kuru epidemic. Finally, PRNP copy number was investigated as a possible genetic mechanism for susceptibility to kuru and sCJD. No conclusive copy number changes were identified
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