Clock Research Articles

611 Mild cognitive impairment is associated with subclinical left ventricular dysfunction as assessed by global longitudinal strain in hypertensive patients

Abstract Aims Left ventricular global longitudinal strain (GLS) detects subtle systolic abnormalities in various cardiovascular conditions, which represent significant risk factors for cognitive impairment and stroke. Specifically, GLS has emerged as a more precise myocardial function measure than left ventricular ejection fraction (LVEF). This study investigated the relationship of GLS with mild cognitive impairment (MCI) in hypertensive patients. Methods and results From February 2020 to October 2021 were enrolled hypertensive patients without atrial fibrillation and/or cerebrovascular and/or neurodegenerative diseases. Complete demographic, clinical characteristics, laboratory analyses, conventional echocardiographic parameters were collected. Finally, MCI was defined by accurate the Quick Mild Cognitive Impairment (QMCI) Screen corrected for age and education. This score explores spatial and temporal orientation, registration, delayed recall, clock design, logical memory, and verbal fluency in a brief time (5 min—score 0–100); a compliance questionnaire (Morisky medication adherence scale); a questionnaire on nutritional status (MNA). 81 hypertensive patients [66 ± 7.27 years; 9 (11%) female] were included in the study. Concerning echocardiographic evaluation, LVEF was 50.47 ± 9.95% and mean GLS was −16.00 ± 3.66. Mean QMCI corrected for age and education was 56.45 ± 9.37, and MCI was detected in 21 patients (26%). When comparing the patients with MCI (QMCItot <49.4) and without MCI (QMCItot >49.4), a statistically significant difference of GLS values was detected (no MCI: −16.52 ± 3.66 vs. MCI: −14.18 ± 3.23; P = 0.032); on the other hand, the two groups did not differ in LVEF (no MCI: 50.58 ± 9.70 vs. MCI: 48.86 ± 11.93; P = 0.864). Furthermore, excluding patients with FE ≥ 45% from the analysis, a statistically significant linear regression was observed between QMCI (corrected for age and education) and the GLS (P = 0.014) (Figure 1). Conclusions Compromised GLS, but not LV EF, is related to MCI in hypertensive patients who are free of clinical dementia, stroke, and neurodegenerative disease. Moreover, our study demonstrates for the first time the existence of a significant association between the QMCI and GLS; consequently, GLS could be an additional parameter in clinical practice for early recognition of MCI. However, studies on a larger population will be needed to confirm this association.

Loss of Timeless Underlies an Evolutionary Transition within the Circadian Clock.

Most organisms possess time-keeping devices called circadian clocks. At the molecular level, circadian clocks consist of transcription–translation feedback loops (TTFLs). Although some components of the negative TTFL are conserved across the animals, important differences exist between typical models, such as mouse and the fruit fly. In Drosophila, the key components are PERIOD (PER) and TIMELESS (TIM-d) proteins, whereas the mammalian clock relies on PER and CRYPTOCHROME (CRY-m). Importantly, how the clock has maintained functionality during evolutionary transitions between different states remains elusive. Therefore, we systematically described the circadian clock gene setup in major bilaterian lineages and identified marked lineage-specific differences in their clock constitution. Then we performed a thorough functional analysis of the linden bug Pyrrhocoris apterus, an insect species comprising features characteristic of both the Drosophila and the mammalian clocks. Unexpectedly, the knockout of timeless-d, a gene essential for the clock ticking in Drosophila, did not compromise rhythmicity in P. apterus, it only accelerated its pace. Furthermore, silencing timeless-m, the ancestral timeless type ubiquitously present across animals, resulted in a mild gradual loss of rhythmicity, supporting its possible participation in the linden bug clock, which is consistent with timeless-m role suggested by research on mammalian models. The dispensability of timeless-d in P. apterus allows drawing a scenario in which the clock has remained functional at each step of transition from an ancestral state to the TIM-d-independent PER + CRY-m system operating in extant vertebrates, including humans.

Modeling and solving the endpoint cutting problem

AbstractThe material cutting process consists of two NP‐hard problems: first, it is necessary to find the optimal cutting pattern to minimize the waste area. Second, it is necessary to find the cutting sequence over the plate to extract the pieces in the shortest possible time. The structure of the cutting path problem can vary according to the technology used in the process. In industries where material can be considered a commodity, the cutting path is decisive due to the need to operate economically and efficiently. These types of minimization demand exact models that use nonconventional formulation techniques in search of computational efficiency and for heuristic processes to be specialized so that a good solution is guaranteed. In this paper, three different approaches were proposed. First, a novel and accurate formulation was presented based on a network flow structure. Second, a reactive GRASP algorithm with solution filtering was designed, using seven operators executed under two randomly selected local search philosophies. Finally, four warm‐start variants were designed hybridizing the GRASP algorithm subprocedures with the exact model. The approaches are compared through benchmarking; for this, a set of instances composed of cutting patterns taken from the solution of classical instances of the two‐dimensional cutting problem was created and made available. The obtained results show that all three approaches solve the problem successfully. Additionally, the computing time is analyzed, illustrating the pros and cons of each approach. Given the cutting path, including the quality of the pieces is left as a future work proposal.

A proof-of-concept model of compact and high-performance 87Sr optical lattice clock for space

A compact and robust design of an optical lattice clock with high stability and accuracy is needed for the implementation of optical clocks operating on the space station. Here, we present the proof-of-concept model of a 87Sr optical lattice clock for space constructed at the National Time Service Center. The design is different from that of a laboratorial optical clock in that it focuses on the aspects of compactness and robustness, such as the modular design, compact components, low power consumption, and all-fiber links. The physics package is placed on an aluminum alloy rack with dimensions of 40 × 55 × 28 cm3. As far as we know, this is the most compact physics package of the Sr optical clock reported. The time interleaved self-comparison frequency instability is determined to be 2.6 × 10−15/τ.

PENERAPAN SIX SIGMA DALAM MEMINIMASI CACAT PRODUK SOUVENIR PADA HOME INDUSTRI MATA KAYU ART

Mata Kayu Art is a center for selling unique souvenirs and furniture, its superior products made of pine wood are placards, sitting clocks, wall clocks, and so on. Home Industry Mata Kayu Art was established in mid-2018, which is located on Jl. Karya, district. Panam, Pekanbaru City. The purpose of this study is to identify the number of defective products and measure the level of sigma and determine the factors that cause defective products so that they can provide suggestions for improvements to the company by redesigning SOPs to reduce defects or defects. The method used is the Six Sigma method, with the steps of Define, Measure, Analyze, Improve, and Control (DMAIC). Based on the calculation results that in the souvenir production process two types of defects become Critical to Quality (CTQ), namely broken and cracked, while souvenir products that often experience defects are Plaque products, Key Chain products, and Sitting Clock products which are then obtained Defect values. per Million Opportunity (DPMO) obtained for Broken defects is 11029 and for Cracked defects is 3676 while the sigma value obtained for Broken defects is 3.79 and for Cracked defects is 4.18. The company strives to be able to implement six sigma with the Define, Measure, Analyze, Improve, and Control (DMAIC) stages to improve quality with the hope that there will be no defects or zero defects.
 Keywords: Defect; DMAIC; DPMO; Six Sigma. 

Design of a Digital Clock Application Using the Atmega 8535 Microcontroller Based Alarm

Seeing the reality that is happening in schools where alarms are needed as a sign or information about the start of lessons, breaks, ends of lessons until coming home from school. This is often done manually. This research was conducted to replace the manual tool with automatic equipment through the design of a digital clock using a Real Time Clock IC that uses an ATMega 8535 microcontroller as the controller of the entire circuit. In this system, a buzzer is used as an alarm and a seven segment as a time display. The time that is the reference in the digital clock is set at the beginning of the use of this digital clock into the RTC IC via a push button so that the microcontroller will retrieve the time data at a certain memory address. Based on the test results, starting from the time set, alarm set, the selection of the alarm sound until the activation of the alarm sound can be controlled by the microcontroller. Overall this system can function as designed.

HAL-ASOS Accelerator Model: Evolutive Elasticity by Design

To address the integration of software threads and hardware accelerators into the Linux Operating System (OS) programming models, an accelerator architecture is proposed, based on micro-programmable hardware system calls, which fully export these resources into the Linux OS user-space through a design-specific virtual file system. The proposed HAL-ASOS accelerator model is split into a user-defined Hardware Task and a parameterizable Hardware Kernel with three differentiated transfer channels, aiming to explore distinct BUS technology interfaces and promote the accelerator to a first-class computing unit. This paper focuses on the Hardware Kernel and mainly its microcode control unit, which will leverage the elasticity to naturally evolve with Linux OS through key differentiating capabilities of field programmable gate arrays (FPGAs) when compared to the state of the art. To comply with the evolutive nature of Linux OS, or any Hardware Task incremental features, the proposed model generates page-faults signaling runtime errors that are handled at the kernel level as part of the virtual file system runtime. To evaluate the accelerator model’s programmability and its performance, a client-side application based on the AES 128-bit algorithm was implemented. Experiments demonstrate a flexible design approach in terms of hardware and software reconfiguration and significant performance increases consistent with rising processing demands or clock design frequencies.

Pseudospectral implementations of long-range corrected density functional theory.

We have implemented pseudospectral density-functional theory (DFT) with long-range corrected DFT functionals (PS-LRC) in quantum mechanics package Jaguar, and applied it in the calculations of geometry optimizations, dimmer interaction energies, polarizabilities and first-order hyperpolarizabilities, harmonic vibrational frequencies, S1 and T1 excitation energies, singlet-triplet gaps, charge transfer numbers, oscillator strengths, reaction barrier heights, electron-transfer couplings, and charge-transfer excitation energies. From our accuracy benchmark analysis, PS grids, PS dealiasing functions, PS atomic corrections, PS multigrid strategy, PS length scales, and PS cutoff scheme perform well in PS DFT with LRC density functionals with very small and ignorable deviations when compared to the conventional spectral (CS) method. The timing benchmark study of S1 excitation energy calculations of fullerenes (Cn , n up to 540) demonstrates that PS-LRC achieves 1.4-8.4-fold speedups in SCF, 22-32-fold speedups in Tamm-Dancoff approximation, and 6-15-fold speedups in total wall clock time with an average error 0.004 eV of excitation energies compared to the CS method.

A Parallel Processing Approach to Dynamic Simulation of Ethylbenzene Process

Parallel computing has been developed for many years in chemical process simulation. However, existing research on parallel computing in dynamic simulation cannot take full advantage of computer performance. More and more applications of data-driven methods and increasing complexity in chemical processes need faster dynamic simulators. In this research, we discuss the upper limit of speed-up for dynamic simulation of the chemical process. Then we design a parallel program considering the process model solving sequence and rewrite the General dynamic simulation & optimization system (DSO) with two levels of parallelism, multithreading parallelism and vectorized parallelism. The dependency between subtasks and the characteristic of the hottest subroutines are analyzed. Finally, the accelerating effect of the parallel simulator is tested based on a 500 kt·a−1 ethylbenzene process simulation. A 5-hour process simulation shows that the highest speed-up ratio to the original program is 261%, and the simulation finished in 70.98 s wall clock time.

PELATIHAN CNC ROUTER UNTUK BUMDES DESA HEUBEULISUK

Heubeulisuk Village is a village located in Argapuran District, Majalengka Regency. Similar to other villages, this village has a Village Owned Enterprise (BUMDes). One of the activities of the BUMDes is the production of wooden wall clocks and several other crafts made of acrylic material.
 Wood Size craftsmen until now only use a simple cutting saw to make the craft and acrylic using a hand drill. The chainsaws facilitated by the local village government are not as sophisticated as imagined.
 With the BUMDes CNC Router machine, it is able to increase the amount of production and minimize the production time required. In this service program scheme, training on the use of CNC Routers for BUMDes Heubeulisuk will be carried out starting assembling, preparing cutting/chiseling tools, making CAD models, CNC controllers to execution/feeding of workpieces.

Perancangan produk fungsional berbahan limbah kayu sisa produksi tempat air kemasan gelas

The initial idea of this research is to exploit the abundance of wood waste material in the form of coins which have almost the same size and thickness. This waste comes from the rest of the production of glass bottled water. One way to achieve this goal is by using horizontal and vertical lamination techniques with the addition of a turning process with the aim of being able to form and produce functions. Another goal is to apply the waste coin arrangement as a functional and decorative product design material. The design of this product with waste is used as a model for empowering the creative industry of the local crafts-producing community where glass mineral water is located in Sambeng Village, Kasiman District, Bojonegoro Regency, East Java. The design method used is the Design Thinking method. The output produced is in the form of functional and decorative product designs, such as stools, wall clocks, frames, candle holders, egg holders, menu boards, and placemats.

Quantum simulations of SARS-CoV-2 main protease Mpro enable high-quality scoring of diverse ligands.

The COVID-19 pandemic has led to unprecedented efforts to identify drugs that can reduce its associated morbidity/mortality rate. Computational chemistry approaches hold the potential for triaging potential candidates far more quickly than their experimental counterparts. These methods have been widely used to search for small molecules that can inhibit critical proteins involved in the SARS-CoV-2 replication cycle. An important target is the SARS-CoV-2 main protease Mpro, an enzyme that cleaves the viral polyproteins into individual proteins required for viral replication and transcription. Unfortunately, standard computational screening methods face difficulties in ranking diverse ligands to a receptor due to disparate ligand scaffolds and varying charge states. Here, we describe full density functional quantum mechanical (DFT) simulations of Mpro in complex with various ligands to obtain absolute ligand binding energies. Our calculations are enabled by a new cloud-native parallel DFT implementation running on computational resources from Amazon Web Services (AWS). The results we obtain are promising: the approach is quite capable of scoring a very diverse set of existing drug compounds for their affinities to M pro and suggest the DFT approach is potentially more broadly applicable to repurpose screening against this target. In addition, each DFT simulation required only ~ 1 h (wall clock time) per ligand. The fast turnaround time raises the practical possibility of a broad application of large-scale quantum mechanics in the drug discovery pipeline at stages where ligand diversity is essential.Electronic supplementary materialThe online version of this article (10.1007/s10822-021-00412-7) contains supplementary material, which is available to authorized users.

Impact of foliar insecticide sprays on Melanaphis sacchari (Hemiptera: Aphididae) and natural enemy populations in grain sorghum

The sugarcane aphid, Melanaphis sacchari is an important pest of grain sorghum (Sorghum bicolor) in the United States. Current M. sacchari management programs aim to control M. sacchari with insecticides while minimizing impacts on natural enemies that contribute to biological control of aphid populations. As a result, balancing both insecticide efficacy on the target pest and preservation of biological control agents remains an important step toward sustainable management of M. sacchari in grain sorghum. To document tradeoffs between M. sacchari control and non-target impacts, we evaluated three common aphicides (afidopyropen, flupyradifurone, and sulfoxaflor) for M. sacchari control and natural enemy safety. Treatments were paired with surfactants when recommended. Insect abundance was measured before and after foliar insecticide application using randomized complete clock design small plot studies during the 2019 and 2020 field seasons. All plots were harvested at maturity to document the relationship between in-season aphid abundance and grain yield. In this two year study, the average aphid abundance three days after insecticide application was lower in some but not all insecticidal treatments when compared to the untreated control, suggesting some insecticides had limited aphid suppression capabilities. Mean cumulative aphid days were lower in all treated plots compared to the untreated control with the exception of Sefina (afidopyropen). Twenty-eight days after foliar insecticide application, there were no differences in total natural enemy abundance in any of the treatments including the untreated control, suggesting that while M. sacchari populations were reduced by foliar insecticide treatments, the insecticides did not have clear adverse effects to natural enemy populations.

Highly efficient implementation of the analytical gradients of pseudospectral time-dependent density functional theory.

The accuracy and efficiency of time-dependent density functional theory (TDDFT) excited state gradient calculations using the pseudospectral method are presented. TDDFT excited state geometry optimizations of the G2 test set molecules, the organic fluorophores with large Stokes shifts, and the Pt-complexes show that the pseudospectral method gives average errors of 0.01-0.1 kcal/mol for the TDDFT excited state energy, 0.02-0.06pm for the bond length, and 0.02-0.12° for the bond angle when compared to the results from conventional TDDFT. TDDFT gradient calculations of fullerenes (Cn, n up to 540) with the B3LYP functional and 6-31G** basis set show that the pseudospectral method provides 8- to 14-fold speedups in the total wall clock time over the conventional methods. The pseudospectral TDDFT gradient calculations with a diffuse basis set give higher speedups than the calculations for the same basis set without diffuse functions included.

Efficient Probabilistic K-NN Computation in Uncertain Sensor Networks

Uncertain data management has recently attracted much research interest in the networking community and database community, as in many emerging applications, e.g., sensor data monitoring, location-based services and vehicle tracking, where data are inherently uncertain due to measurement errors, update delays etc. The probabilistic k nearest neighbor (k-PNN) query returns k objects with the highest probability of being the k-th nearest neighbor from a given query point Q. However, compared to the traditional k-NN over precise data, the computation cost of k-PNN is rather expensive due to the costly numerical integration or Monte-Carlo approach it adopts, which raises a challenge in answering k-PNN in very large uncertain sensor networks. To address this challenge, we propose an efficient strategy for processing k-PNN queries. Specifically, we introduce two effective pruning methods, spatial pruning and probabilistic pruning, to speed up the query procedure by reducing the search space. The spatial pruning is based on the bounding region of the k-th nearest neighbor, while the probabilistic pruning is based on the lower and upper probability bounds of each k-NN candidate object after spatial pruning. Extensive experiments have been implemented to demonstrate the efficiency and effectiveness of our proposed method under various settings, in terms of both wall clock time and the number of candidate objects to be evaluated.

A Comparative Study of Block Incomplete Sparse Approximate Inverses Preconditioning on Tesla K20 and V100 GPUs

Incomplete Sparse Approximate Inverses (ISAI) has shown some advantages over sparse triangular solves on GPUs when it is used for the incomplete LU based preconditioner. In this paper, we extend the single GPU method for Block–ISAI to multiple GPUs algorithm by coupling Block–Jacobi preconditioner, and introduce the detailed implementation in the open source numerical package PETSc. In the experiments, two representative cases are performed and a comparative study of Block–ISAI on up to four GPUs are conducted on two major generations of NVIDIA’s GPUs (Tesla K20 and Tesla V100). Block–Jacobi preconditioning with Block–ISAI (BJPB-ISAI) shows an advantage over the level-scheduling based triangular solves from the cuSPARSE library for the cases, and the overhead of setting up Block–ISAI and the total wall clock times of GMRES is greatly reduced using Tesla V100 GPUs compared to Tesla K20 GPUs.

Pelatihan Rancang Bangun Jam Sholat Otomatis Sumber Daya Solar Cell pada Pemuda Muhammadiyah Cabang Pahlawan Perjuangan dan Pulo Brayan Darat

Through the service that will be carried out, namely by conducting training activities on the design of automatic clocks with solar panel resources using additional tools in the form of Arduino Uno, in order to be a solution amid the increasing population of unemployment in the city of Medan. Various Arduino Uno boards use different ± different types of Atmega depending on the specifications, for example the Arduino Uno uses the ATmega328 while the more sophisticated Arduino Mega 2560 uses the ATmega2560. The use of solar panel energy will be designed in the form of an LCD Prayer Timer and Adhan Alarm method with a 200WP solar cell resource using the Arduino Uno programming system. Therefore, the Muhammadiyah Youth Leaders of the Heroes of the Struggle Branch and Pulo Brayan Darat are expected to be foster partners in improving these very useful design skills, so that they can serve as examples to young people around in improving the economic level of skilled and creative organizations.

Efficient solution of block Toeplitz systems with multiple right-hand sides arising from a periodic boundary element formulation

Block Toeplitz matrices are a special class of matrices that exhibit reduced memory requirements and a reduced complexity of matrix-vector multiplications. We herein present an efficient computational approach to solve a sequence of block Toeplitz systems arising from a block Toeplitz system with multiple right-hand sides. Two different numerical schemes are implemented for the solution of the sequence of block Toeplitz systems based on global and block variants of the generalized minimal residual (GMRES) method. The performance of the schemes is assessed in terms of the wall clock time of the iterative solution process, the number of multiplications with the block Toeplitz system matrix and the peak memory usage. To demonstrate the method, two numerical examples are presented. In the first case study, aeroacoustic prediction of an airfoil in turbulent flow is examined, which requires multiple solutions of the wall pressure field beneath the turbulent boundary layer. The fluctuating pressure on the surface of the airfoil is synthesized in terms of uncorrelated wall plane waves, whereby each realization of the wall pressure field is an input to the acoustic solver based on the boundary element method (BEM). The total acoustic response from the airfoil in turbulent flow is then obtained from an ensemble average for the number of realizations considered. The number of realizations to yield a converged solution for the wall pressure field leads to a sequence of block Toeplitz systems. The second case study examines the nonlinear eigenvalue analysis of a sonic crystal barrier composed of locally resonant C-shaped sound-hard scatterers. The periodicity of the sound barrier leads to a block Toeplitz system matrix whereas the nonlinear eigenvalue problem requires the solution of sequences of linear systems. The combined technique to solve the sequences of block Toeplitz systems using the proposed variants of the GMRES is shown to yield a computationally efficient approach for flow noise prediction and nonlinear eigenvalue analysis.

The Utrecht Finite Volume Ice-Sheet Model: UFEMISM (version 1.0)

Abstract. Improving our confidence in future projections of sea-level rise requires models that can simulate ice-sheet evolution both in the future and in the geological past. A physically accurate treatment of large changes in ice-sheet geometry requires a proper treatment of processes near the margin, like grounding line dynamics, which in turn requires a high spatial resolution in that specific region, so that small-scale topographical features are resolved. This leads to a demand for computationally efficient models, where such a high resolution can be feasibly applied in simulations of 105–107 years in duration. Here, we present and evaluate a new ice-sheet model that solves the hybrid SIA–SSA approximation of the stress balance, including a heuristic rule for the grounding-line flux. This is done on a dynamic adaptive mesh which is adapted to the modelled ice-sheet geometry during a simulation. Mesh resolution can be configured to be fine only at specified areas, such as the calving front or the grounding line, as well as specified point locations such as ice-core drill sites. This strongly reduces the number of grid points where the equations need to be solved, increasing the computational efficiency. A high resolution allows the model to resolve small geometrical features, such as outlet glaciers and sub-shelf pinning points, which can significantly affect large-scale ice-sheet dynamics. We show that the model reproduces the analytical solutions or model intercomparison benchmarks for a number of schematic ice-sheet configurations, indicating that the numerical approach is valid. Because of the unstructured triangular mesh, the number of vertices increases less rapidly with resolution than in a square-grid model, greatly reducing the required computation time for high resolutions. A simulation of all four continental ice sheets during an entire 120 kyr glacial cycle, with a 4 km resolution near the grounding line, is expected to take 100–200 wall clock hours on a 16-core system (1600–3200 core hours), implying that this model can be feasibly used for high-resolution palaeo-ice-sheet simulations.

Design and operation of a transportable 87Rb atomic fountain clock.

A transportable fountain clock with high reliability is important for high-precision time-frequency measurements. Because of its relatively small cold atoms' collision frequency shift and ease of attaining high quantum state preparation efficiency, the rubidium atomic fountain clock has an indicated higher stability and reliability. This paper reports the design and operation of a transportable rubidium atomic fountain clock developed by the Shanghai Institute of Optical and Fine Mechanics, Chinese Academy of Science. After being transported more than 1000 km from Shanghai to the Changping Campus of the National Institute of Metrology, China, the optical platform and other hardware of the fountain clock did not need to be adjusted. The rubidium fountain clock maintained a stability of 4.0 × 10-13τ1/2, reaching 5.0 × 10-16 at 300 000s. After transportation, the rubidium fountain clock and a cesium fountain clock (NIM5) were operated together against the reference frequency of a hydrogen maser. In three separate operating periods, over a total of nearly three months, the average frequency repeatability of the rubidium fountain was less than 3.8 × 10-15.