804 research outputs found

    Large-scale discovery and validation of functional elements in the human genome

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    A report on the genomics workshop 'Identification of Functional Elements in Mammalian Genomes', Cold Spring Harbor, New York, 11-13 November 2004

    HAMSTRINGS COACTIVATION IN TRAINED LONG JUMPERS AND UNTRAINED INDIVIDUALS DURING DROP JUMPING

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    The purpose of this study was to examine the EMG activity patterns of the hamstrings during drop jumping from different heights in trained longer jumpers and controls. A group of trained long jumpers and a group of untrained subjects performed maximal drop jumps from 20cm, 40cm and 60 cm on a force platform. The surface EMG activity of the hamstrings was recorded using bipolar electrodes. The ground reaction forces (GRF) and 3-D kinematic data were also recorded. Two-way analysis of variance tests indicated non-significant differences in hamstring EMG amplitude between trained and untrained athletes. However, the long jumpers had significantly higher vertical GRF values and some kinematic differences compared to untrained individuals. The absence of higher hamstrings activity in the long jumpers may have been a contributing factor in their higher performance compared to controls. However, the same result indicates that this increased performance may be accompanied by a possible increased risk of knee joint instability

    EFFECTS OF A 10 WEEK TRAINING PROGRAM ON PHYSICAL CONDITIONING AND INSTEP KICK KINEMATICS IN SOCCER

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    The instep kick is the kick of choice in soccer scoring and passing over medium to long distances. Its success depends on many factors including the strength of the muscles responsible for the actions of the (kicking lower) extremity, the rate of muscle force production, the synchronization and energy transfer between lower extremity segments (Plagenhoef, 1971), the linear approach velocity (Opavsky, 1988) and approach angle (Isokawa and Less, 1988), and the ability of muscle to utilize effectively the stretch/shorten cycle (BOhrle, 1985). Ultimately, on a given kick, the velocity of the kicking foot and the point of (foot) force application on the ball determine the trajectory characteristics of the ball. Other factors such as flexibility and aerobic/anaerobic capacities also determine the ability of players to successfully perform in a game. The purpose of this study was to study the effects of a 10 week training program on selected physical conditioning and instep kick kinematic parameters in soccer

    LLMs Understand Glass-Box Models, Discover Surprises, and Suggest Repairs

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    We show that large language models (LLMs) are remarkably good at working with interpretable models that decompose complex outcomes into univariate graph-represented components. By adopting a hierarchical approach to reasoning, LLMs can provide comprehensive model-level summaries without ever requiring the entire model to fit in context. This approach enables LLMs to apply their extensive background knowledge to automate common tasks in data science such as detecting anomalies that contradict prior knowledge, describing potential reasons for the anomalies, and suggesting repairs that would remove the anomalies. We use multiple examples in healthcare to demonstrate the utility of these new capabilities of LLMs, with particular emphasis on Generalized Additive Models (GAMs). Finally, we present the package TalkToEBM\texttt{TalkToEBM} as an open-source LLM-GAM interface

    A single Hox locus in Drosophila produces functional microRNAs from opposite DNA strands

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    MicroRNAs (miRNAs) are approximately 22-nucleotide RNAs that are processed from characteristic precursor hairpins and pair to sites in messages of protein-coding genes to direct post-transcriptional repression. Here, we report that the miRNA iab-4 locus in the Drosophila Hox cluster is transcribed convergently from both DNA strands, giving rise to two distinct functional miRNAs. Both sense and antisense miRNA products target neighboring Hox genes via highly conserved sites, leading to homeotic transformations when ectopically expressed. We also report sense/antisense miRNAs in mouse and find antisense transcripts close to many miRNAs in both flies and mammals, suggesting that additional sense/antisense pairs exist

    Survey of variation in human transcription factors reveals prevalent DNA binding changes

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    Published in final edited form as: Science. 2016 Mar 25; 351(6280): 1450–1454. Published online 2016 Mar 24. doi: 10.1126/science.aad2257Sequencing of exomes and genomes has revealed abundant genetic variation affecting the coding sequences of human transcription factors (TFs), but the consequences of such variation remain largely unexplored. We developed a computational, structure-based approach to evaluate TF variants for their impact on DNA binding activity and used universal protein-binding microarrays to assay sequence-specific DNA binding activity across 41 reference and 117 variant alleles found in individuals of diverse ancestries and families with Mendelian diseases. We found 77 variants in 28 genes that affect DNA binding affinity or specificity and identified thousands of rare alleles likely to alter the DNA binding activity of human sequence-specific TFs. Our results suggest that most individuals have unique repertoires of TF DNA binding activities, which may contribute to phenotypic variation.National Institutes of Health; NHGRI R01 HG003985; P50 HG004233; A*STAR National Science Scholarship; National Science Foundatio

    Joint profiling of DNA methylation and chromatin architecture in single cells.

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    We report a molecular assay, Methyl-HiC, that can simultaneously capture the chromosome conformation and DNA methylome in a cell. Methyl-HiC reveals coordinated DNA methylation status between distal genomic segments that are in spatial proximity in the nucleus, and delineates heterogeneity of both the chromatin architecture and DNA methylome in a mixed population. It enables simultaneous characterization of cell-type-specific chromatin organization and epigenome in complex tissues

    Conflicting and ambiguous names of overlapping ORFs in the SARS-CoV-2 genome: A homology-based resolution.

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    At least six small alternative-frame open reading frames (ORFs) overlapping well-characterized SARS-CoV-2 genes have been hypothesized to encode accessory proteins. Researchers have used different names for the same ORF or the same name for different ORFs, resulting in erroneous homological and functional inferences. We propose standard names for these ORFs and their shorter isoforms, developed in consultation with the Coronaviridae Study Group of the International Committee on Taxonomy of Viruses. We recommend calling the 39 codon Spike-overlapping ORF ORF2b; the 41, 57, and 22 codon ORF3a-overlapping ORFs ORF3c, ORF3d, and ORF3b; the 33 codon ORF3d isoform ORF3d-2; and the 97 and 73 codon Nucleocapsid-overlapping ORFs ORF9b and ORF9c. Finally, we document conflicting usage of the name ORF3b in 32 studies, and consequent erroneous inferences, stressing the importance of reserving identical names for homologs. We recommend that authors referring to these ORFs provide lengths and coordinates to minimize ambiguity caused by prior usage of alternative names

    Soft X-Ray Tomography Reveals Gradual Chromatin Compaction and Reorganization during Neurogenesis In Vivo

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    SummaryThe realization that nuclear distribution of DNA, RNA, and proteins differs between cell types and developmental stages suggests that nuclear organization serves regulatory functions. Understanding the logic of nuclear architecture and how it contributes to differentiation and cell fate commitment remains challenging. Here, we use soft X-ray tomography (SXT) to image chromatin organization, distribution, and biophysical properties during neurogenesis in vivo. Our analyses reveal that chromatin with similar biophysical properties forms an elaborate connected network throughout the entire nucleus. Although this interconnectivity is present in every developmental stage, differentiation proceeds with concomitant increase in chromatin compaction and re-distribution of condensed chromatin toward the nuclear core. HP1β, but not nucleosome spacing or phasing, regulates chromatin rearrangements because it governs both the compaction of chromatin and its interactions with the nuclear envelope. Our experiments introduce SXT as a powerful imaging technology for nuclear architecture

    Defining functional DNA elements in the human genome

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    With the completion of the human genome sequence, attention turned to identifying and annotating its functional DNA elements. As a complement to genetic and comparative genomics approaches, the Encyclopedia of DNA Elements Project was launched to contribute maps of RNA transcripts, transcriptional regulator binding sites, and chromatin states in many cell types. The resulting genome-wide data reveal sites of biochemical activity with high positional resolution and cell type specificity that facilitate studies of gene regulation and interpretation of noncoding variants associated with human disease. However, the biochemically active regions cover a much larger fraction of the genome than do evolutionarily conserved regions, raising the question of whether nonconserved but biochemically active regions are truly functional. Here, we review the strengths and limitations of biochemical, evolutionary, and genetic approaches for defining functional DNA segments, potential sources for the observed differences in estimated genomic coverage, and the biological implications of these discrepancies. We also analyze the relationship between signal intensity, genomic coverage, and evolutionary conservation. Our results reinforce the principle that each approach provides complementary information and that we need to use combinations of all three to elucidate genome function in human biology and disease
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