401 research outputs found

    Time-dependent, diffusion-controlled reactions: The influence of boundaries

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    A configurational averaging procedure is presented for the analysis of diffusion-controlled reactions in a medium containing a hard-sphere distribution of spherical sinks. The hierarchy of equations produced from the averaging procedure is truncated assuming low concentration of sinks. The method is shown to reproduce previous results for the decay of an initially uniform distribution of reactant in an unbounded medium and is subsequently applied to determine the reactant flux on the boundary of a semiinfinite domain. In the latter problem, the boundary has a significant effect which cannot be accounted for by the usual rate coefficient

    Joint Attention and Occupations for Children and Families Living with Autism Spectrum Disorder: A Scoping Review

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    Background: Research reports that children living with autism spectrum disorder (ASD) may demonstrate deficits in social, emotional, behavioral, and communication skills, which adversely affect social participation and occupational engagement. Joint attention skills constitute any nonverbal communication that captures the attention of another to create a shared interactional experience. The components of joint attention can be targeted through intervention to promote occupational engagement in childhood co-occupations. Methods: A scoping review process was applied in the current study. Nineteen studies met the inclusion criteria to be analyzed through critical appraisal of topics and use of a matrix. Results: Evidence indicates that joint attention skills can be developed in children living with ASD through targeted teaching interventions. Analysis of the data elucidated emergent themes in the form of commonly used strategies to develop joint attention skills in children living with ASD. Conclusion: Joint attention teaching strategies can be implemented to develop social interaction performance skills in children living with ASD. The benefits of developing joint attention skills in this population directly relate to improved occupational and co-occupational engagement. Joint attention teaching strategies naturally align with occupational therapy techniques and approaches and should be considered as an enhancement to occupational therapy intervention

    Expressive Art to Facilitate the Development of the Occupational Profile: A Scoping Review

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    Background. The American Occupational Therapy Association and the American Medical Association have changed CPT codes to require a completed occupational profile at every evaluation and re-evaluation session for reimbursement as of January 1, 2017. A revitalization of art in occupational therapy has led to a recent increase in the evidence supporting the use of expressive art in practice. The benefits of expressive art can directly enhance the occupational profile required by these changing reimbursement requirements. Methods. A scoping review method was applied in the current study. Out of 347 initial articles, 12 met the inclusion criteria and were analyzed through critical appraisal of topics and use of a matrix. Results. Analysis of the data elucidated emergent themes of expressive art’s positive effects on verbal communication, the client’s therapeutic reflection, the accuracy of information, the clinician’s use of prompting, the therapeutic relationship, and client engagement. Conclusion. Expressive art can strengthen the occupational profile and information-gathering process. The benefits related to using art in occupational therapy may enhance the complexity of the overall evaluation process, as described by newly changing CPT codes. Expressive art techniques can facilitate the development of client-centered goals and individualized intervention planning, creating an overall positive service delivery process

    A New Algorithm for Automatic History Matching

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    History-matching problems, in which reservoir parameters arc to be estimated from well pressure data, are formulated as optimal control problems. The necessary conditions for optimality lead naturally to gradient optimization methods for determining the optimal parameter estimates. The key feature of the approach is that reservoir properties are considered as continuous functions of position rather than as uniform in a certain number of zones. The optimal control approach is illustrated on a hypothetical reservoir and on an actual Saudi Arabian reservoir, both characterized by single-phase flow. A significant saving in computing time over conventional constant-zone gradient optimization methods is demonstrated

    Smart Tourism Destinations: Can the Destination Management Organizations Exploit Benefits of the ICTs? Evidences from a Multiple Case Study

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    Recent developments of ICTs enable new ways to experience tourism and conducted to the concept of smart tourism. The adoption of cutting-edge technologies and its combination with innovative organizational models fosters cooperation, knowledge sharing, and open innovation among service providers in tourism destination. Moreover, it offers innovative services to visitors. In few words, they become smart tourism destinations. In this paper, we report first results of the SMARTCAL project aimed at conceiving a digital platform assisting Destination Management Organizations (DMOs) in providing smart tourism services. A DMO is the organization charged with managing the tourism offer of a collaborative network, made up of service providers acting in a destination. In this paper, we adopted a multiple case studies approach to analyze five Italian DMOs. Our aims were to investigate (1) if, and how, successful DMOs were able to offer smart tourism services to visitors; (2) if the ICTs adoption level was related to the collaboration level among DMO partners. First results highlighted that use of smart technologies was still in an embryonic stage of development, and it did not depend from collaboration levels

    An ultraconserved Hox–Pbx responsive element resides in the coding sequence of Hoxa2 and is active in rhombomere 4

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    The Hoxa2 gene has a fundamental role in vertebrate craniofacial and hindbrain patterning. Segmental control of Hoxa2 expression is crucial to its function and several studies have highlighted transcriptional regulatory elements governing its activity in distinct rhombomeres. Here, we identify a putative Hox–Pbx responsive cis-regulatory sequence, which resides in the coding sequence of Hoxa2 and is an important component of Hoxa2 regulation in rhombomere (r) 4. By using cell transfection and chromatin immunoprecipitation (ChIP) assays, we show that this regulatory sequence is responsive to paralogue group 1 and 2 Hox proteins and to their Pbx co-factors. Importantly, we also show that the Hox–Pbx element cooperates with a previously reported Hoxa2 r4 intronic enhancer and that its integrity is required to drive specific reporter gene expression in r4 upon electroporation in the chick embryo hindbrain. Thus, both intronic as well as exonic regulatory sequences are involved in Hoxa2 segmental regulation in the developing r4. Finally, we found that the Hox–Pbx exonic element is embedded in a larger 205-bp long ultraconserved genomic element (UCE) shared by all vertebrate genomes. In this respect, our data further support the idea that extreme conservation of UCE sequences may be the result of multiple superposed functional and evolutionary constraints

    Mapping of Human Autoantibody Binding Sites on the Calcium-Sensing Receptor

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    Previously, we have demonstrated the presence of anti-calcium-sensing receptor (CaSR) antibodies in patients with autoimmune polyglandular syndrome type 1 (APS1), a disease that is characterized in part by hypoparathyroidism involving hypocalcemia, hyperphosphatemia, and low serum levels of parathyroid hormone. The aim of this study was to define the binding domains on the CaSR of anti-CaSR antibodies found in APS1 patients and in one patient suspected of having autoimmune hypocalciuric hypercalcemia (AHH). A phage-display library of CaSR peptides was constructed and used in biopanning experiments with patient sera. Selectively enriched IgG-binding peptides were identified by DNA sequencing, and subsequently, immunoreactivity to these peptides was confirmed in ELISA. Anti-CaSR antibody binding sites were mapped to amino acid residues 41–69, 114–126, and 171–195 at the N-terminal of the extracellular domain of the receptor. The major autoepitope was localized in the 41–69 amino acid sequence of the CaSR with antibody reactivity demonstrated in 12 of 12 (100%) APS1 patients with anti-CaSR antibodies and in 1 AHH patient with anti-CaSR antibodies. Minor epitopes were located in the 114–126 and 171–195 amino acid domains, with antibody reactivity shown in 5 of 12 (42%) and 4 of 12 (33%) APS1 patients, respectively. The results indicate that epitopes for anti-CaSR antibodies in the AHH patient and in the APS1 patients who were studied are localized in the N-terminal of the extracellular domain of the receptor. The present work has demonstrated the successful use of phage-display technology in the discovery of CaSR-specific epitopes targeted by human anti-CaSR antibodies. © 2010 American Society for Bone and Mineral Research

    Directed Neural Differentiation of Mouse Embryonic Stem Cells Is a Sensitive System for the Identification of Novel Hox Gene Effectors

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    The evolutionarily conserved Hox family of homeodomain transcription factors plays fundamental roles in regulating cell specification along the anterior posterior axis during development of all bilaterian animals by controlling cell fate choices in a highly localized, extracellular signal and cell context dependent manner. Some studies have established downstream target genes in specific systems but their identification is insufficient to explain either the ability of Hox genes to direct homeotic transformations or the breadth of their patterning potential. To begin delineating Hox gene function in neural development we used a mouse ES cell based system that combines efficient neural differentiation with inducible Hoxb1 expression. Gene expression profiling suggested that Hoxb1 acted as both activator and repressor in the short term but predominantly as a repressor in the long run. Activated and repressed genes segregated in distinct processes suggesting that, in the context examined, Hoxb1 blocked differentiation while activating genes related to early developmental processes, wnt and cell surface receptor linked signal transduction and cell-to-cell communication. To further elucidate aspects of Hoxb1 function we used loss and gain of function approaches in the mouse and chick embryos. We show that Hoxb1 acts as an activator to establish the full expression domain of CRABPI and II in rhombomere 4 and as a repressor to restrict expression of Lhx5 and Lhx9. Thus the Hoxb1 patterning activity includes the regulation of the cellular response to retinoic acid and the delay of the expression of genes that commit cells to neural differentiation. The results of this study show that ES neural differentiation and inducible Hox gene expression can be used as a sensitive model system to systematically identify Hox novel target genes, delineate their interactions with signaling pathways in dictating cell fate and define the extent of functional overlap among different Hox genes
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