106 research outputs found
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Dopamine receptor D4 (DRD4) polymorphisms with reduced functional potency intensify atrophy in syndrome-specific sites of frontotemporal dementia.
ObjectiveWe aimed to understand the impact of dopamine receptor D4 (DRD4) polymorphisms on neurodegeneration in patients with dementia. We hypothesized that DRD4dampened-variants with reduced functional potency would be associated with greater atrophy in regions with higher receptor density. Given that DRD4 is concentrated in anterior regions of the limbic and cortical forebrain we anticipated genotype effects in patients with a more rostral pattern of neurodegeneration.Methods337 subjects, including healthy controls, patients with Alzheimer's disease (AD) and frontotemporal dementia (FTD) underwent genotyping, structural MRI, and cognitive/behavioral testing. We conducted whole-brain voxel-based morphometry to examine the relationship between DRD4 genotypes and brain atrophy patterns within and across groups. General linear modeling was used to evaluate relationships between genotype and cognitive/behavioral measures.ResultsDRD4 dampened-variants predicted gray matter atrophy in disease-specific regions of FTD in anterior cingulate, ventromedial prefrontal, orbitofrontal and insular cortices on the right greater than the left. Genotype predicted greater apathy and repetitive motor disturbance in patients with FTD. These results covaried with frontoinsular cortical atrophy. Peak atrophy patterned along regions of neuroanatomic vulnerability in FTD-spectrum disorders. In AD subjects and controls, genotype did not impact gray matter intensity.ConclusionsWe conclude that DRD4 polymorphisms with reduced functional potency exacerbate neuronal injury in sites of higher receptor density, which intersect with syndrome-specific regions undergoing neurodegeneration in FTD
I-SceI-Mediated Double-Strand Break Does Not Increase the Frequency of Homologous Recombination at the Dct Locus in Mouse Embryonic Stem Cells
Targeted induction of double-strand breaks (DSBs) at natural endogenous loci was shown to increase the rate of gene replacement by homologous recombination in mouse embryonic stem cells. The gene encoding dopachrome tautomerase (Dct) is specifically expressed in melanocytes and their precursors. To construct a genetic tool allowing the replacement of Dct gene by any gene of interest, we generated an embryonic stem cell line carrying the recognition site for the yeast I-SceI meganuclease embedded in the Dct genomic segment. The embryonic stem cell line was electroporated with an I-SceI expression plasmid, and a template for the DSB-repair process that carried sequence homologies to the Dct target. The I-SceI meganuclease was indeed able to introduce a DSB at the Dct locus in live embryonic stem cells. However, the level of gene targeting was not improved by the DSB induction, indicating a limited capacity of I-SceI to mediate homologous recombination at the Dct locus. These data suggest that homologous recombination by meganuclease-induced DSB may be locus dependent in mammalian cells
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Chase-and-run between adjacent cell populations promotes directional collective migration
Collective cell migration in morphogenesis and cancer progression often involves the coordination of multiple cell types. How reciprocal interactions between adjacent cell populations lead to new emergent behaviours remains unknown. Here we studied the interaction between neural crest (NC) cells, a highly migratory cell population, and placodal cells, an epithelial tissue that contributes to sensory organs. We found that NC cells chase placodal cells by chemotaxis, and placodal cells run when contacted by NC. Chemotaxis to Sdf1 underlies the chase, and repulsion involving PCP and N-cadherin signalling is responsible for the run. This chase-and-run requires the generation of asymmetric forces, which depend on local inhibition of focal adhesions. The cell interactions described here are essential for correct NC migration and for segregation of placodes in vivo and are likely to represent a general mechanism of coordinated migration
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Anthropogenic intensification of short-duration rainfall extremes
Short- duration (1-3 h) rainfall extremes can cause serious damage to societies through rapidly developing (flash) flooding and are determined by complex, multifaceted processes that are altering as Earth's climate warms. In this Review, we examine evidence from observational, theoretical and modelling studies for the intensification of these rainfall extremes, the drivers and the impact on flash flooding. Both short- duration and long- duration (\textgreater1 day) rainfall extremes are intensifying with warming at a rate consistent with the increase in atmospheric moisture (~7% K-1), while in some regions, increases in short- duration extreme rainfall intensities are stronger than expected from moisture increases alone. These stronger local increases are related to feedbacks in convective clouds, but their exact role is uncertain because of the very small scales involved. Future extreme rainfall intensification is also modulated by changes to temperature stratification and large- scale atmospheric circulation. The latter remains a major source of uncertainty. Intensification of short- duration extremes has likely increased the incidence of flash flooding at local scales and this can further compound with an increase in storm spatial footprint to considerably increase total event rainfall. These findings call for urgent climate change adaptation measures to manage increasing flood risks
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Open source - opens learning: Why open source makes sense for education
This white paper from the r-smart group discusses open source software and it's benefits in education
Religion and violence, Religion and Peace: Essays from the Center for Christian-Jewish Understanding Conference in Auschwitz, Poland, May 1998
Based on papers presented at a 1998 conference held in Auschwitz and sponsored by the Center for Christian-Jewish Understanding at Sacred Heart University, this volume focuses on the role that religion plays in cultivating peace or promoting violence.
Contents: Preface / Joseph H. Ehrenkranz -- Opening remarks / Anthony J. Cernera, Franciszek Cardinal Macharski, Archbishop Jeremiasz -- Part I. The problem of violence -- The problem of religion, violence, and peace: an uneasy trilogy / David L. Coppola -- Blood and hope / Samuel Pisar -- Anger and courage: a reply to Samuel Pisar / Elisabeth Maxwell -- Fundamentalism as a precursor to violence / Martin E. Marty -- Part II. The possibility of peace in Judaism, Christianity, and Islam -- The roots of peace in the Torah / Rene-Samuel Sirat -- The roots of peace in the New Testament / Cahal Brendan Cardinal Daly -- The roots of peace in the Qur\u27an / Amira Shamma Abdin -- Part III. Bridges to greater understanding -- The role of religion in the pursuit of peace / David Rosen -- Pastoral reflections / William Cardinal Keeler -- The great jubilee: a time of remembrance / Georges Cottier.https://digitalcommons.sacredheart.edu/shupress_bks/1007/thumbnail.jp
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