926 research outputs found

    Static Data Structure Lower Bounds Imply Rigidity

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    We show that static data structure lower bounds in the group (linear) model imply semi-explicit lower bounds on matrix rigidity. In particular, we prove that an explicit lower bound of tω(log2n)t \geq \omega(\log^2 n) on the cell-probe complexity of linear data structures in the group model, even against arbitrarily small linear space (s=(1+ε)n)(s= (1+\varepsilon)n), would already imply a semi-explicit (PNP\bf P^{NP}\rm) construction of rigid matrices with significantly better parameters than the current state of art (Alon, Panigrahy and Yekhanin, 2009). Our results further assert that polynomial (tnδt\geq n^{\delta}) data structure lower bounds against near-optimal space, would imply super-linear circuit lower bounds for log-depth linear circuits (a four-decade open question). In the succinct space regime (s=n+o(n))(s=n+o(n)), we show that any improvement on current cell-probe lower bounds in the linear model would also imply new rigidity bounds. Our results rely on a new connection between the "inner" and "outer" dimensions of a matrix (Paturi and Pudlak, 2006), and on a new reduction from worst-case to average-case rigidity, which is of independent interest

    Novel missense mutation in the bZIP transcription factor, MAF, associated with congenital cataract, developmental delay, seizures and hearing loss (Ayme-Gripp syndrome)

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    Published online: 08 May 2017Background: Cataract is a major cause of severe visual impairment in childhood. The purpose of this study was to determine the genetic cause of syndromic congenital cataract in an Australian mother and son. Method: Fifty-one genes associated with congenital cataract were sequenced in the proband using a custom Ampliseq library on the Ion Torrent Personal Genome Machine (PGM). Reads were aligned against the human genome (hg19) and variants were annotated. Variants were prioritised for validation by Sanger sequencing if they were novel, rare or previously reported to be associated with paediatric cataract and were predicted to be protein changing. Variants were assessed for segregation with the phenotype in the affected mother. Result: A novel likely pathogenic variant was identified in the transactivation domain of the MAF gene (c.176C > G, p.(Pro59Arg)) in the proband and his affected mother., but was absent in 326 unrelated controls and absent from public variant databases. Conclusion: The MAF variant is the likely cause of the congenital cataract, Asperger syndrome, seizures, hearing loss and facial characteristics in the proband, providinga diagnosis of Aymé-Gripp syndrome for the family.Shari Javadiyan, Jamie E. Craig, Shiwani Sharma, Karen M. Lower, Theresa Casey, Eric Haan, Emmanuelle Souzeau and Kathryn P. Burdo

    Socioeconomic Disparities in North Carolina Communities: Issues of Access and Quality of Licensed Child Care.

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    The purpose of the current study was to examine the relationship between child care program quality and the socioeconomic contexts of the communities in which they operate. The sample, which included nearly all licensed child care providers in North Carolina in 2008, resulted in 6882 programs nested within 619 zip codes and 78 counties. The cross-sectional design integrated data from multiple sources. Child care program characteristics, including rated program quality, were acquired from the North Carolina Division of Child Development. Data from the U.S. Census Bureau was used to measure socioeconomic characteristics of communities at the zip code level. Data from the North Carolina State Head Start Collaboration Office, North Carolina Office of School Readiness, and the North Carolina Division of Child Development were incorporated to examine program funding and subsidy levels from various sources. Data from the North Carolina Partnership for Children were used to identify quality enhancement funds at the county level. Multi-level modeling was utilized to examine the nested data structure of child care programs within communities. Child care quality varied across communities and program quality was modestly correlated when programs were in closer proximity. Program level characteristics, as well as community level socioeconomics were both related to differential quality among child care programs, suggesting that access to high quality child care varies across community contexts

    Localization of Native Mms13 to the Magnetosome Chain of Magnetospirillum magneticum AMB-1 Using Immunogold Electron Microscopy, Immunofluorescence Microscopy and Biochemical Analysis

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    Magnetotactic bacteria (MTB) biomineralize intracellular magnetite (Fe3O4 ) crystals surrounded by a magnetosome membrane (MM). The MM contains membrane-specific proteins that control Fe3O4 mineralization in MTB. Previous studies have demonstrated that Mms13 is a critical protein within the MM. Mms13 can be isolated from the MM fraction of Magnetospirillum magneticum AMB-1 and a Mms13 homolog, MamC, has been shown to control the size and shape of magnetite nanocrystals synthesized in-vitro. The objective of this study was to use several independent methods to definitively determine the localization of native Mms13 in M. magneticum AMB-1. Using Mms13-immunogold labeling and transmission electron microscopy (TEM), we found that Mms13 is localized to the magnetosome chain of M. magneticum AMB-1 cells. Mms13 was detected in direct contact with magnetite crystals or within the MM. Immunofluorescence detection of Mms13 in M. magneticum AMB-1 cells by confocal laser scanning microscopy (CLSM) showed Mms13 localization along the length of the magnetosome chain. Proteins contained within the MM were resolved by SDS-PAGE for Western blot analysis and LC-MS/MS (liquid chromatography with tandem mass spectrometry) protein sequencing. Using Anti-Mms13 antibody, a protein band with a molecular mass of ~14 kDa was detected in the MM fraction only. This polypeptide was digested with trypsin, sequenced by LC-MS/MS and identified as magnetosome protein Mms13. Peptides corresponding to the protein’s putative MM domain and catalytic domain were both identified by LC-MS/MS. Our results (Immunogold TEM, Immunofluorescence CLSM, Western blot, LC-MS/MS), combined with results from previous studies, demonstrate that Mms13 and homolog proteins MamC and Mam12, are localized to the magnetosome chain in MTB belonging to the class Alphaproteobacteria. Because of their shared localization in the MM and highly conserved amino acid sequences, it is likely that MamC, Mam12, and Mms13 share similar roles in the biomineralization of Fe3O4 nanocrystals.National Science Foundation, grant number EAR-2038207EAR-1423939Ministerio de Economía y Competitividad, SPAIN and Fondo Europeo de Desarrollo Regional, FEDER grant numbers CGL2010-18274 and CGL2013-4661

    Child care work environments: The relationship with learning environments.

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    Abstract: The study explores the relationship between child care program administration, organizational climate, and global quality. The recently developed Program Administration Scale (PAS

    Electron-impact ionization and excitation of helium to the n=1-4 ionic states

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    We present high-precision (e; 2e) measurements and calculations for the e-He four-body Coulomb breakup problem. Cross-section ratios for ionization and excitation of the first three excited states of He+ relative to the ground state have been measured for incident energies between 112 and 319 eV. Comparing the data with predictions from a state-of-the-art hybrid distorted-wave + convergent R matrix with pseudostates (close coupling) approach shows that treating the projectile-target interaction at least to second order is crucial to obtain reasonable agreement between theory and experiment. Nevertheless, our benchmark studies reveal significant theoretical problems for the symmetric energy-sharing cases, thus indicating the need for further improvement.S. Bellm, J. Lower and K. Bartscha

    Benchmark experiment and theory for near-threshold excitation of helium by electron impact

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    A new experimental technique has been applied to measure absolute scattering cross sections for electron impact excitation of the n ≤ 2, 3 states of helium at near-threshold energies. The experimental results are compared with predictions from recent state-of-the-art theoretical calculations. The calculations are performed using the R-matrix with pseudostates, B-spline R-matrix, and the convergent close-coupling methods. Generally, very good agreement is found between the experiment and the three theorie

    U.S. adolescent and adult women\u27s experiences accessing and using toilets in schools, workplaces, and public spaces: A multi-site focus group study to inform future research in bladder health

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    The World Health Organization recognizes access to clean and safe toilets as crucial for public health. This study explored U.S. adolescent and adult cisgender women\u27s lived experiences accessing toilets in schools, workplaces, and public spaces. As part of the Prevention of Lower Urinary Tract Symptoms (PLUS) Research Consortium, we conducted 44 focus groups with female participants (n = 360; ages 11-93). Focus groups were stratified by age (11-14, 15-17, 18-25, 26-44, 45-64, 65+) and conducted across 7 geographically diverse U.S. sites from July 2017-April 2018. Using a transdisciplinary approach, we conducted conventional qualitative coding informed by our PLUS conceptual framework and used content analysis processes to identify salient themes. Across settings, toilet access was restricted by gatekeepers (i.e., individuals who control access to toilets). In contrast, self-restricting toilet use (deciding not to use the toilet despite biologic need to urinate) was based on internalized norms to prioritize school and job responsibilities over urination. In public spaces, self-restricting use was largely in response to lack of cleanliness. Across the life course, participants perceived gender disparities in the ability to easily access public toilets. Further research is needed to determine if and how these factors impact bladder health across the life course

    Teachers, Families, and Communities Supporting English Language Learners in Inclusive Pre-Kindergartens: An Evaluation of a Professional Development Model

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    The purpose of the Teachers, Families, and Communities Supporting English Language Learners (TFC) project was to implement and evaluate a sustainable model of high-quality professional development focused on improving inclusive pre-kindergarten services for English Language Learners (ELL) and their families. The professional development program consisted of three interactive training sessions and on-site classroom coaching visits. The project evaluation consisted of an assessment of the professional development program (i.e., the training sessions and coaching) and teachers' self-assessments of their beliefs and practices. Results indicate that the professional development program supported pre-kindergarten teachers in their efforts to be responsive to ELL children in their classrooms and with their families. Results also indicate that pre-kindergarten teachers are in need of continued support as they work with linguistically and culturally diverse children and their families. Implications for future professional development focused on English Language Learners are discussed
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