59 research outputs found
PEAK LOWER EXTREMITY NET JOINT MOMENTS AND JOINT ANGLES DURING ISOMETRIC MID-THIGH PULLS VARY WITH BAR POSITION
The purpose of this study was to identify the effect of bar position on the ankle, knee, and hip peak net joint moments (NJM) and associated joint angles during isometric mid-thigh pulls (IMTP). Seven female college lacrosse players performed maximal IMTP at three different bar positions (low: above patella, mid: mid-thigh, high: crease of hip) while motion capture and GRF data were recorded. Inverse dynamics was used to calculate peak ankle, knee, and hip NJM. Joint angles at peak NJM were also extracted. Main effects for bar position existed for hip NJM and hip and knee joint angles. Pair-wise comparisons showed that hip NJM differed significantly between all positions. Strength and sports coaches should consider these results when they use the IMTP to assess and monitor maximal strength as part of their conditioning programs
Effects of intelligence and approximate number system on the non-symbolic division ability in preschoolers
Recently, it has become evident that cognitive abilities such as the approximate number system (ANS), number knowledge, and intelligence affect individualsâ fundamental mathematical ability. However, it is unclear which of these cognitive abilities have the greatest impact on the non-symbolic division ability in preschoolers. Therefore, in the present study, we included 4- to 6-year-old Korean preschoolers without prior formal education of division in order to test their ability to solve non-symbolic division problems, ANS acuity, and intelligence, and to determine the interrelationships among those functions (Nâ=â38). We used the Panamath Dot Comparison Paradigm to measure the ANS acuity, employed non-symbolic division tasks to measure the ability to solve non-symbolic division problems, and measured the intelligence using the Korean version of the WPPSI-IV (Wechsler Preschool Primary Scale of Intelligence-IV). Our results showed that, in all conditions of the non-symbolic division tasks, the 4- to 6-years old children were able to perform better than chance level. Additionally, in a relatively easy condition, the childrenâs performance showed a significant positive correlation with full-scale intelligence quotient (FSIQ) and ANS acuity; however, in a more complex condition, only FSIQ was significantly correlated with their performance. Overall, we found significant relationships between the childrenâs performance in the non-symbolic division tasks and verbal comprehension, fluid reasoning, and processing speed index. Taken together, our findings demonstrate that preschoolers without formal education on the arithmetic problem solving can solve non-symbolic division problems. Moreover, we suggest that both FSIQ and ANS ability play essential roles in childrenâs ability to solve non-symbolic division problems, highlighting the significance of intelligence on childrenâs fundamental mathematical ability
B Lymphocytes of Xeroderma Pigmentosum or Cockayne Syndrome Patients with Inherited Defects in Nucleotide Excision Repair Are Fully Capable of Somatic Hypermutation of Immunoglobulin Genes
Recent experiments have strongly suggested that the process of somatic mutation is linked to transcription initiation. It was postulated that a mutator factor loads onto the RNA polymerase and, during elongation, causes transcriptional arrest that activates DNA repair, thus occasionally causing errors in the DNA sequence. We report the analysis of the role of one of the known DNA repair systems, nucleotide excision repair (NER), in somatic mutation. EpsteinâBarrvirus-transformed B cells from patients with defects in NER (XP-B, XP-D, XP-V, and CS-A) were studied. Their heavy and light chain genes show a high frequency of point mutations in the variable (V), but not in the constant (C) regions. This suggests that these B cells can undergo somatic hypermutation despite significant defects in NER. Thus, it is doubtful that NER is an essential part of the mechanism of somatic hypermutation of Ig genes. As an aside, NER seems also not involved in Ig gene switch recombination
JOINT- AND LOAD-SPECIFIC ASYMMETRIES DURING THREE LOWER EXTREMITY RESISTANCE TRAINING EXERCISES
The purpose of this study was characterize the consistency of limb symmetries at the knee and hip in the front squat, hexagonal barbell deadlift, and Romanian deadlift across three loads (40%, 60%, 80% of front squat one-repetition maximum). Eight female collegiate soccer players performed three repetitions at each aforementioned load and for each exercise while motion capture and ground reaction force data were recorded. Bilateral net joint moments were calculated and used to quantify joint-specific limb symmetry indices (LSI) for each exercise and loading condition. Correlation analyses revealed similarity in LSI at the knee and hip within all exercises and between the front squat and hexagonal barbell deadlift. At the joint level, greater biomechanical similarity between tasks seems to result in greater consistency of interlimb asymmetries
PIRH2-Dependent Dna Damage in Neurons Induced by the G-Quadruplex Ligand Pyridostatin
Noncanonical base pairing between four guanines (G) within single-stranded G-rich sequences leads to formation of Đ° G-quartet. Self-stacking of G-quartets results in a columnar four-stranded DNA structure known as the G-quadruplex (G4 or G4-DNA). In cancer cells, G4-DNA regulates multiple DNA-dependent processes, including transcription, replication, and telomere function. How G4s function in neurons is poorly understood. Here, we performed a genome-wide gene expression analysis (RNA-Seq) to identify genes modulated by a G4-DNA ligand, pyridostatin (PDS), in primary cultured neurons. PDS promotes stabilization of G4 structures, thus allowing us to define genes directly or indirectly responsive to G4 regulation. We found that 901 genes were differentially expressed in neurons treated with PDS out of a total of 18,745 genes with measured expression. Of these, 505 genes were downregulated and 396 genes were upregulated and included gene networks regulating p53 signaling, the immune response, learning and memory, and cellular senescence. Within the p53 network, the E3 ubiquitin ligase Pirh2 (Rchy1), a modulator of DNA damage responses, was upregulated by PDS. Ectopically overexpressing Pirh2 promoted the formation of DNA double-strand breaks, suggesting a new DNA damage mechanism in neurons that is regulated by G4 stabilization. Pirh2 downregulated DDX21, an RNA helicase that unfolds G4-RNA and R-loops. Finally, we demonstrated that Pirh2 increased G4-DNA levels in the neuronal nucleolus. Our data reveal the genes that are responsive to PDS treatment and suggest similar transcriptional regulation by endogenous G4-DNA ligands. They also connect G4-dependent regulation of transcription and DNA damage mechanisms in neuronal cells
Small-molecule G-quadruplex stabilizers reveal a novel pathway of autophagy regulation in neurons
International audienc
The Draft Genome of an Octocoral, Dendronephthya gigantea
Coral reefs composed of stony corals are threatened by global marine environmental changes. However, soft coral communities of octocorallian species, appear more resilient. The genomes of several cnidarians species have been published, including from stony corals, sea anemones, and hydra. To fill the phylogenetic gap for octocoral species of cnidarians, we sequenced the octocoral, Dendronephthya gigantea, a nonsymbiotic soft coral, commonly known as the carnation coral. The D. gigantea genome size is similar to 276 Mb. A high-quality genome assembly was constructed from PacBio long reads (29.85 Gb with 108x coverage) and Illumina short paired-end reads (35.54 Gb with 128x coverage) resulting in the highest N50 value (1.4 Mb) reported thus far among cnidarian genomes. About 12% of the genome is repetitive elements and contained 28,879 predicted protein-coding genes. This gene set is composed of 94% complete BUSCO ortholog benchmark genes, which is the second highest value among the cnidarians, indicating high quality. Based on molecular phylogenetic analysis, octocoral and hexacoral divergence times were estimated at 544 MYA. There is a clear difference in Hox gene composition between these species: unlike hexacorals, the Antp superclass Evx gene was absent in D. gigantea. Here, we present the first genome assembly of a nonsymbiotic octocoral, D. gigantea to aid in the comparative genomic analysis of cnidarians, including stony and soft corals, both symbiotic and nonsymbiotic. The D. gigantea genome may also provide clues to mechanisms of differential coping between the soft and stony corals in response to scenarios of global warming
- âŠ