SUMM4 complex couples insulator function and DNA replication timing control

The asynchronous timing of replication of different chromosome domains is essential for eukaryotic genome stability, but the mechanisms establishing replication timing programs remain incompletely understood. Drosophila SNF2-related factor SUUR imparts under- replication (UR) of late-replicating intercalary heterochromatin (IH) domains in polytene chromosomes1. SUUR negatively regulates DNA replication fork progression across IH; however, its mechanism of action remains obscure2, 3. Here we developed a novel method termed MS-Enabled Rapid protein Complex Identification (MERCI) to isolate a stable stoichiometric native complex SUMM4 that comprises SUUR and a chromatin boundary protein Mod(Mdg4)- 67.24, 5. In vitro, Mod(Mdg4) stimulates the ATPase activity of SUUR, although neither SUUR nor SUMM4 can remodel nucleosomes. Mod(Mdg4)-67.2 and SUUR distribution patterns in vivo partially overlap, and Mod(Mdg4) is required for a normal spatiotemporal distribution of SUUR in chromosomes. SUUR and Mod(Mdg4)-67.2 mediate insulator activities of the gypsy mobile element that disrupt enhancer-promoter interactions and establish euchromatin- heterochromatin barriers in the genome. Furthermore, mutations of SuUR or mod(mdg4) reverse the locus-specific UR. These findings reveal that DNA replication can be delayed by a chromatin barrier and thus, uncover a critical role for architectural proteins in replication timing control. They also provide a biochemical link between ATP-dependent motor factors and the activity of insulators in regulation of gene expression and chromatin partitioning.

Performance of Bimanual Finger Coordination Tasks in Speakers Who Stutter

Stuttering is a neurodevelopmental speech disorder characterized by the symptoms of speech repetition, prolongation, and blocking. Stuttering-related dysfluency can be transiently alleviated by providing an external timing signal such as a metronome or the voice of another person. Therefore, the existence of a core motor timing deficit in stuttering has been speculated. If this is the case, then motoric behaviors other than speech should be disrupted in stuttering. This study examined motoric performance on four complex bimanual tasks in 37 adults who stutter and 31 fluent controls. Two tasks utilized bimanual rotation to examine motor dexterity, and two tasks used the bimanual mirror and parallel tapping movements to examine timing control ability. Video-based analyses were conducted to determine performance accuracy and speed. The results showed that individuals who stutter performed worse than fluent speakers on tapping tasks but not on bimanual rotation tasks. These results suggest stuttering is associated with timing control for general motor behavior.

KINEMATICS OF THE DISTRIBUTION MECHANISM OF THE HYUNDAI ENGINE WITH ADJUSTABLE VALVE OPERATING TIME

Increasing the efficiency of modern internal combustion engines is going in the direction of optimizing the gas distribution phases in order to adjust them to the operating conditions of motor vehicles. Hyundai has announced the development of the first production engine with continuously variable valve operation time – Continuously Variable Valve Duration. (Research purpose) The research purpose is in conducting a kinematic analysis of the gas distribution mechanism with an adjustable valve operating time, identifying the theoretical possibilities of this mechanism in comparison with the information provided in the prospects. (Materials and methods) The methods of kinematic analysis of lever mechanisms were used in the work. (Results and discussion) The analysis of the design of the gas distribution mechanism with an adjustable valve operating time made it possible to choose a suitable structural scheme that is equivalent to the original mechanism. The article presents the most effective method of kinematic analysis of this mechanism and developed on its basis a program for calculating the angles of rotation of the cam and the shaft of the gas distribution mechanism. (Conclusions) An engine with a valve operating time control system allows you to more effectively adjust the cylinder filling depending on the operating conditions due to the variable phase of rotation of the camshaft. The valve timing control system offered by Hyundai should only work with the valve timing control mechanism, since when the cam rotation speed changes, it starts working in the wrong phase that should be at a given time. With a slow rotation of the cam, it lags behind in phase from the shaft of the gas distribution mechanism, and with a fast rotation of the cam, on the contrary, the phase advance of the shaft of the gas distribution mechanism occurs.

Temporal Control of Seed Development in Dicots: Molecular Bases, Ecological Impact and Possible Evolutionary Ramifications

In flowering plants, seeds serve as organs of both propagation and dispersal. The developing seed passes through several consecutive stages, following a conserved general outline. The overall time needed for a seed to develop, however, may vary both within and between plant species, and these temporal developmental properties remain poorly understood. In the present paper, we summarize the existing data for seed development alterations in dicot plants. For genetic mutations, the reported cases were grouped in respect of the key processes distorted in the mutant specimens. Similar phenotypes arising from the environmental influence, either biotic or abiotic, were also considered. Based on these data, we suggest several general trends of timing alterations and how respective mechanisms might add to the ecological plasticity of the families considered. We also propose that the developmental timing alterations may be perceived as an evolutionary substrate for heterochronic events. Given the current lack of plausible models describing timing control in plant seeds, the presented suggestions might provide certain insights for future studies in this field.

Construction and analysis of a three-channel numerical control ring-spinning system for segment colored yarn

At present, there have been a significant number of studies of segment colored yarn, and the majority of these studies have made considerable progress, which has made the types and styles of segment colored yarn more abundant. However, the problem that exists in the segment colored yarn is its relatively few kinds of color, which greatly limits its flexibility and diversity in commercial applications. To address the above problems, a multi-channel computer numerical control (CNC) ring-spinning machine was developed, and a digital spinning mechanism with online regulation of the forming linear density and blending ratio was constructed through the developed three-channel drafting mechanism and its driving and controlling system; the spinning mechanism of segment colored yarn using the time-varying three-channel drafting ratio to the spinning time-varying three-colored fiber blending ratio was established by implementing a coupling algorithm for co-drafting of multi-channel roving; the forming process and algorithm of segment colored yarn, which is used to solve the blending ratio of three colored fibers and the drafting ratio of three-channel roving based on segment color, was constructed through the digital color mixing model and the design of segment color of yarn. According to the above mechanism, three rovings with two color combinations of cyan, magenta, yellow and cyan, magenta, black were used to design and spin segment colored yarns with three, five and seven colors, respectively. By testing and analyzing the linear density, twist, unevenness, surface hairiness and tensile properties of the segment colored yarn, it is proved that the timing control of the three-channel drafting ratio based on CNC ring spinning can achieve the timing control of the blending ratio of the three colored fibers, which is beneficial to the spinning of segment colored yarn with color segment distribution.

Specifics and Vulnerabilities of the Timing Control in Cyber-Physical Systems

Cyber-physical systems integrate powerful computing (real-time embedded system, operating system, applications, and Internet networking) and physical environment (advanced manufacturing cells, medical platforms, energetics aggregates, social and educational control). The reliable functionality depends extremely on the correct timing. Wrong timing because of buried malfunction or external tampering could be critical. The paper is some analysis of the vulnerable timing parameters that influence the precise processing. Expert estimation of the criticality of different timing parameters is given to support fault-tolerant design considering possible failures.

Beat patterns determine inter-hand differences in synchronization error in a bimanual coordination tapping task.

A previous study reported the unique finding that people tap a beat pattern with the right hand earlier than with the left hand or other effectors, in contrast to previous studies that have shown that the hands tap patterns simultaneously without any synchronization errors. We examined whether the inter-hand difference in synchronization error occurred due to handedness or to a specificity of the beat pattern employed in that study. Two experiments manipulated the hand–beat assignments. A comparison between the identical beat to the pacing signal and a beat with a longer interval excluded the handedness hypothesis and demonstrated that beat patterns with relatively shorter intervals were tapped earlier (Experiment 1). These synchronization errors were not local but occurred consistently throughout the beat patterns. Experiment 2 excluded alternative explanations. These results indicate that the apparent inconsistency in previous studies was due to the specificity of the beat patterns, suggesting that a beat pattern with a shorter interval is tapped earlier than beats with longer intervals. Our results are consistent with a model of central timing control in bimanual tapping.