Sequential Shift Research Articles

Transient Notch Activation Converts Pluripotent Stem Cell-Derived Cardiomyocytes Towards a Purkinje Fiber Fate.

Cardiac Purkinje fibers form the most distal part of the ventricular conduction system. They coordinate contraction and play a key role in ventricular arrhythmias. While many cardiac cell types can be generated from human pluripotent stem cells, methods to generate Purkinje fiber cells remain limited, hampering our understanding of Purkinje fiber biology and conduction system defects. To identify signaling pathways involved in Purkinje fiber formation, we analyzed single cell data from murine embryonic hearts and compared Purkinje fiber cells to trabecular cardiomyocytes. This identified several genes, processes, and signaling pathways putatively involved in cardiac conduction, including Notch signaling. We next tested whether Notch activation could convert human pluripotent stem cell-derived cardiomyocytes to Purkinje fiber cells. Following Notch activation, cardiomyocytes adopted an elongated morphology and displayed altered electrophysiological properties including increases in conduction velocity, spike slope, and action potential duration, all characteristic features of Purkinje fiber cells. RNA-sequencing demonstrated that Notch-activated cardiomyocytes undergo a sequential transcriptome shift, which included upregulation of key Purkinje fiber marker genes involved in fast conduction such as SCN5A, HCN4 and ID2, and downregulation of genes involved in contractile maturation. Correspondingly, we demonstrate that Notch-induced cardiomyocytes have decreased contractile force in bioengineered tissues compared to control cardiomyocytes. We next modified existing in silico models of human pluripotent stem cell-derived cardiomyocytes using our transcriptomic data and modeled the effect of several anti-arrhythmogenic drugs on action potential and calcium transient waveforms. Our models predicted that Purkinje fiber cells respond more strongly to dofetilide and amiodarone, while cardiomyocytes are more sensitive to treatment with nifedipine. We validated these findings in vitro , demonstrating that our new cell-specific in vitro model can be utilized to better understand human Purkinje fiber physiology and its relevance to disease.

Assessment of Fallopian Tube Epithelium Features Derived from Induced Pluripotent Stem Cells of Both Fallopian Tube and Skin Origins.

Fallopian tube epithelial cells (FTECs) play a significant role in the development of high-grade serous ovarian cancer (HGSOC), but their utilization in in vitro experiments presents challenges. To address these limitations, induced pluripotent stem cells (iPSCs) have been employed as a potential solution, driven by the hypothesis that orthologous iPSCs may offer superior differentiation capabilities compared with their non-orthologous counterparts. Our objective was to generate iPSCs from FTECs, referred to as FTEC-iPSCs, and compare their differentiation potential with iPSCs derived from skin keratinocytes (NHEK). By introducing a four-factor Sendai virus transduction system, we successfully derived iPSCs from FTECs. To assess the differentiation capacity of iPSCs, we utilized embryoid body formation, revealing positive immunohistochemical staining for markers representing the three germ layers. In vivo tumorigenesis evaluation further validated the pluripotency of iPSCs, as evidenced by the formation of tumors in immunodeficient mice, with histological analysis confirming the presence of tissues from all three germ layers. Quantitative polymerase chain reaction (qPCR) analysis illuminated a sequential shift in gene expression, encompassing pluripotent, mesodermal, and intermediate mesoderm-related genes, during the iPSC differentiation process into FTECs. Notably, the introduction of WNT3A following intermediate mesoderm differentiation steered the cells toward a FTEC phenotype, supported by the expression of FTEC-related markers and the formation of tubule-like structures. In specific culture conditions, the expression of FTEC-related genes was comparable in FTECs derived from FTEC-iPSCs compared with those derived from NHEK-iPSCs. To conclude, our study successfully generated iPSCs from FTECs, demonstrating their capacity for FTEC differentiation. Furthermore, iPSCs originating from orthologous cell sources exhibited comparable differentiation capabilities. These findings hold promise for using iPSCs in modeling and investigating diseases associated with these specific cell types.

Changes in the immune cell landscape in the infarcted mouse heart

Abstract Background Myocardial Infarction (MI) and Ischemic Heart Failure represent the leading causes of death globally. Myocardial remodeling after MI is accompanied and driven by a strong immune response with an accumulation of several, partially opposing immune cell types. The temporal and spatial dynamics of this cardiac specific immune cell infiltration, however, have not been systematically evaluated. Purpose We characterized the dynamics of the immune cell repertoire in murine hearts following myocardial infarction by multi-color flow cytometry using a novel 12-marker panel allowing us to characterize major principal leukocyte lineages with a total of 10 distinct leukocyte populations. In parallel, we studied the immune response after MI in secondary lymph organs such as heart´s draining lymph nodes and the spleen. In addition, we performed transcriptional analysis of the healthy and infarcted hearts by bulk RNA at selected time points. Methods Permanent ligation of the left descending coronary artery (LAD), ischemic/reperfusion injury (I/R) and sham surgery was performed on C57BL6/J, 10 weeks old male mice. Leukocytes dynamics and T cell responses were screened in infarcted and remote areas of the heart, as well as in blood, spleen, and heat´s draining lymph nodes after 1, 3, 7, 14 and 28 days by multi-color flow cytometry. Also, immune activation and exhaustion transcription analysis by bulk RNA of healthy and infarcted hearts was performed at day 3,7 and 28 days after MI. Results We describe a sequential shift in the resident heart leukocyte population, a change in T cell activation states and identified potential new targets such as NK and γ/δ T cells. While macrophages area the most frequent leukocytes under steady state, making up to 75% of the total relative leukocyte population, at day 28 Lymphocytes represent 50%, among which B cells represent the most of them, followed by T helper cells. At early stages, CD4+ T cells secret pro inflammatory cytokines in the heart and in the heart´s draining lymph nodes, however, as stable scar in the heart is formed at day 7 immunomodulatory cytokines secretion such as IL-10 was observed. This is consistent with the build-up of a relevant adaptive immune response involving antigen presenting DCs and effector T and B cells in the healing heart. Conclusions Our findings contribute to identify novel cellular and transcriptional targets in the fight against ischemic heart failure.

The crystalline structure transition and hydrogen bonds shift determining enhanced enzymatic digestibility of cellulose treated by ultrasonication

Global energy issue raised the necessity to develop second-generation biofuels, and biorefinery of cellulosic biomass becomes a promising solution. Various pretreatments were used to overcome the cellulose nature of recalcitrance and improve the enzymatic digestibility, but the lack of mechanism understanding hindered the development of efficient and cost-effective technologies of cellulose utilization. Using structure-based analysis, we demonstrate that the improved hydrolysis efficiency caused by ultrasonication was ascribed to the changed cellulose properties rather than the increased dissolubility. Further, isothermal titration calorimetry (ITC) analysis suggested that enzymatic digestion of cellulose is an entropically favored reaction driven by hydrophobic forces other than an enthalpically favored reaction. The changes in cellulose properties and thermodynamic paramenters due to ultrasonication accounted for the improved accessibility. Ultrasonication-treated cellulose showed porous, rough and disordered morphology, accompanying with the loss of crystalline structure. Despite the unaffected unit cell structure, ultrasonication expanded the crystalline lattice by increasing grain sizes and average cross-sectional area, resulting in the transformation from cellulose I to cellulose II, with the decreased crystallinity, better hydrophilicity and increased enzymatic bioaccessibility. Furthermore, FTIR combined with two-dimensional correlation spectroscopy (2D-CoS) verified that the sequential shift of hydroxyl group and intramolecular/intermolecular hydrogen bonds, the functional groups governing cellulose crystal structure and stability, accounted for the ultrasonication-induced transition of cellulose crystalline structure. This study provides a comprehensive picture of cellulose structure and property response caused by mechanistic treatments and will open up avenues to develop novel pretreatments for efficient utilization.

Direct Access to 9/6‐Fused Cycles via Sequential Hydride Shift Mediated Double C(sp3)−H Bond Functionalization

AbstractWe have developed a sequential hydride shift process involving a [1,8]‐hydride shift. When cinnamylidene malonates having a biphenyl core were treated with 30 mol% Yb(OTf)3 and 10 mol% iPr2NEt, the desired sequential [1,8]‐[1,5]‐hydride shift process proceeded smoothly to afford synthetically challenging nine‐membered carbocycle‐fused piperidine derivatives in good chemical yields (up to 77%). Notably, the desired nine‐membered carbocycles could not be obtained by a single [1,8]‐hydride shift/cyclization process, suggesting that the employment of the sequential system is crucial to achieving the reaction.magnified image

First-principles analysis of novel Mg-based group II-VI materials for advanced optoelectronics devices

Here, in this work, the structural, electronic, optical, and transport properties of Magnesium-based group II-VI materials are studied by employing the density functional theory calculations. The WC-GGA and EV-GGA generalized gradient approximations were employed to compute the structure parameters along with the electronic nature of the ternary-type materials. Our calculations confirmed the materials to be indirect band-type semiconductors with a bandgap value of 1.17 ​eV, and 0.51 ​eV, for the MgCdO2 and MgCdS2 materials respectively. Since Sulfur has a larger atomic radius than Oxygen, the bandgap value declines in going from MgCdO2 to MgCdS2 material. The computed total density of states for these materials displayed a sequential shift with increasing energy. The linear optical parameters like the real and imaginary parts of the dielectric function, the energy loss function, the absorption coefficient, the reflectivity, and the refractive index values are calculated and analyzed in detail. Moreover, the thermoelectric properties were also computed, and the results are presented in depth, suggesting all these materials to be efficient for thermoelectric device applications.

Sequential Doppler-Shift-Based Optimal Localization and Synchronization With TOA

Doppler shift is an important measurement for localization and synchronization (LAS), and is available in various practical systems. Existing studies on LAS techniques in a time-division broadcast LAS system (TDBS) only use sequential time-of-arrival (TOA) measurements from the broadcast signals. In this article, we develop a new optimal LAS method in the TDBS, namely, LAS-SDT, by taking advantage of the sequential Doppler shift and TOA measurements. It achieves higher accuracy compared with the conventional TOA-only method for user devices (UDs) with motion and clock drift. Another two variant methods, LAS-SDT-v for the case with UD velocity aiding and LAS-SDT-k for the case with UD clock drift aiding, are developed. We derive the Cramér–Rao lower bound (CRLB) for these different cases. We show analytically that the accuracies of the estimated UD position, clock offset, velocity, and clock drift are all significantly higher than those of the conventional LAS method using TOAs only. Numerical results corroborate the theoretical analysis and show the optimal estimation performance of the LAS-SDT.

Intensive mothering in the time of coronavirus

AbstractWe investigated experiences of mothers of school‐age children in Central New York during a time of remote education due to COVID‐19. We extend the concept of intensive mothering, characterized by the expectation that mothers are constantly available to meet their children's needs, and examine mothers’ intersectional identities related to their experience of remote education. Mothers working from home often went back and forth between work and school in what we refer to as a simultaneous shift. Essential workers were engaged in a sequential shift, engaging with children's schoolwork after work and trading off with partners. Mothers took on multiple roles during the pandemic which led to role strain. In extreme cases, multiple roles could be impossible to fill, leading to a situation of role conflict where the demands of one role made it impossible to meet the needs of another role. Mothers of children of color experienced more negative interactions with schools than White mothers. Mothers of children with disabilities spent extended time on remote schooling. A limitation of our study is that we only interviewed people in Central New York and cannot generalize the results of our research to a larger population. Another limitation to our approach was that we have little information on how fathers experienced work and overseeing children's schoolwork. Future research should examine how mothering may have changed after children returned to school.

Low Power Linear Feedback Shift Register Using DY-CML

A Linear Feedback Shift Register (LFSR) is a sequential shift register that cycles through a succession of binary values in a pseudo-random way using combinational logic. Pseudo-noise sequences, whitening sequences, and fast digital counters are some of the applications of LFSR. The design of a 4-bit LFSR employing CMOS, MOS Current-Mode Logic (MCML), and Dynamic Current-Mode Logic (DY-CML) approaches are shown in this paper. MCML has low power consumption and better performance. The disadvantage of MCML approach is that it has more static power dissipation due to the constant current source. In order to solve the issues of MCML approach, the DY-CML with a dynamic current source is used to design the LFSR. All designs are simulated using the Mentor graphics tool, which uses 90nm technology. This paper also includes a comparison of LFSR’s in terms of power, delay, and transistor count.

Fast aberration compensation based on sequential shift and differential–integral based algorithm in digital holographic microscopy

Digital holographic microscopy is a high-precision, high-resolution quantitative detection method, however, aberration compensation significantly increases the data processing time. We herein propose a method based on sequential shift and a differential–integral algorithm to compensate for fast phase aberrations. The proposed method obtains the phase derivative of the real sample phase information through holograms at different positions and then reconstructs the aberration-free phase result through integration. The compensation avoids complex phase polynomial fitting calculations or optimization iterations, achieves extremely fast aberration compensation, and can theoretically eliminate various low and high-order aberrations, including extremely complex aberrations. We experimentally validate the effectiveness and high speed of the proposed method by imaging paramecium samples.

Circularly polarized sequentially rotated antenna array for dual‐band WLAN applications

This article presents a dual-band circularly polarized (CP) 2 × 2 sequentially rotated (SR) antenna array with four slot antennas, a wideband sequential-phase shifter (SPS), and reflected plane for wireless local area network (WLAN) operations. By designing the four slot antennas for dual-band CP operations, the wideband SPS including four outputs with a sequential phase shift of 90° for improving bandwidth, and a conductor-backed reflected plane for enhancing antenna gain, a high-gain and dual-band CP SR antenna array can be realized. The measured impedance bandwidth for return loss of 10 dB is 93.81% (2.36-6.5 GHz). Both measured CP bandwidths for axial ratio of 3 dB are 22.64% (2.35-2.95 GHz) and 49.16% (4.5-6.77 GHz), which can cover all the WLAN bands. Maximum antenna gains are 12.32, 9.91, and 11.66 dBic in the range of 2.4 to 2.484, 5.15 to 5.35, and 5.725 to 5.875 GHz, respectively.

Instance-Level Relative Saliency Ranking With Graph Reasoning.

Conventional salient object detection models cannot differentiate the importance of different salient objects. Recently, two works have been proposed to detect saliency ranking by assigning different degrees of saliency to different objects. However, one of these models cannot differentiate object instances and the other focuses more on sequential attention shift order inference. In this paper, we investigate a practical problem setting that requires simultaneously segment salient instances and infer their relative saliency rank order. We present a novel unified model as the first end-to-end solution, where an improved Mask R-CNN is first used to segment salient instances and a saliency ranking branch is then added to infer the relative saliency. For relative saliency ranking, we build a new graph reasoning module by combining four graphs to incorporate the instance interaction relation, local contrast, global contrast, and a high-level semantic prior, respectively. A novel loss function is also proposed to effectively train the saliency ranking branch. Besides, a new dataset and an evaluation metric are proposed for this task, aiming at pushing forward this field of research. Finally, experimental results demonstrate that our proposed model is more effective than previous methods. We also show an example of its practical usage on adaptive image retargeting.

Multiscale spatial variability in epibiont assemblage structure associated with stipes of kelp Laminaria hyperborea in the northeast Atlantic

Foundation species elevate local biodiversity and underpin critical ecological processes and functions. Kelp species are distributed along ~25% of the world’s coastlines, where they serve as foundation species in intertidal and subtidal habitats. As well as ameliorating environmental conditions and producing organic matter, they provide biogenic habitat for a vast array of associated organisms. Here, we investigated patterns of diversity and structure in assemblages associated with the stipe of the kelp Laminaria hyperborea in the NE Atlantic. Stipes were sampled at 4 study regions (with 3 sites nested within each region) in the UK, spanning ~9° of latitude. Stipe-associated communities were highly diverse (134 species) and abundant (16-4532 ind. stipe-1), with no obvious sequential shift in diversity or overall trends in abundance/biomass of assemblages with latitude. However, we observed high degrees of variability between sites from the same region and individuals within sites, indicating that processes working across smaller spatial scales were more important than those at regional scales. While we observed high between-site variability in assemblage structure, regional differences were also evident. Most notably, sites within our southernmost region (southern England) were largely devoid of amphipods that dominated all other regions. This study highlights the important role of L. hyperborea in elevating biodiversity at local to regional scales through a facilitative interaction. Moreover, given that L. hyperborea forests may be increasingly impacted by ocean warming, changes in coastal water quality and proposed exploitation, our study serves as an important benchmark against which to detect future changes.

Clariant preserves profitability in first nine months of 2020 despite difficult economic environment: 3Q 2020

Here, in this work, the structural, electronic, optical, and transport properties of Magnesium-based group II-VI materials are studied by employing the density functional theory calculations. The WC-GGA and EV-GGA generalized gradient approximations were employed to compute the structure parameters along with the electronic nature of the ternary-type materials. Our calculations confirmed the materials to be indirect band-type semiconductors with a bandgap value of 1.17 ​eV, and 0.51 ​eV, for the MgCdO2 and MgCdS2 materials respectively. Since Sulfur has a larger atomic radius than Oxygen, the bandgap value declines in going from MgCdO2 to MgCdS2 material. The computed total density of states for these materials displayed a sequential shift with increasing energy. The linear optical parameters like the real and imaginary parts of the dielectric function, the energy loss function, the absorption coefficient, the reflectivity, and the refractive index values are calculated and analyzed in detail. Moreover, the thermoelectric properties were also computed, and the results are presented in depth, suggesting all these materials to be efficient for thermoelectric device applications.

Multiple drivers of the COVID-19 spread: The roles of climate, international mobility, and region-specific conditions.

Following its initial appearance in December 2019, coronavirus disease 2019 (COVID-19) quickly spread around the globe. Here, we evaluated the role of climate (temperature and precipitation), region-specific COVID-19 susceptibility (BCG vaccination factors, malaria incidence, and percentage of the population aged over 65 years), and human mobility (relative amounts of international visitors) in shaping the geographical patterns of COVID-19 case numbers across 1,020 countries/regions, and examined the sequential shift that occurred from December 2019 to June 30, 2020 in multiple drivers of the cumulative number of COVID-19 cases. Our regression model adequately explains the cumulative COVID-19 case numbers (per 1 million population). As the COVID-19 spread progressed, the explanatory power (R2) of the model increased, reaching > 70% in April 2020. Climate, host mobility, and host susceptibility to COVID-19 largely explained the variance among COVID-19 case numbers across locations; the relative importance of host mobility and that of host susceptibility to COVID-19 were both greater than that of climate. Notably, the relative importance of these factors changed over time; the number of days from outbreak onset drove COVID-19 spread in the early stage, then human mobility accelerated the pandemic, and lastly climate (temperature) propelled the phase following disease expansion. Our findings demonstrate that the COVID-19 pandemic is deterministically driven by climate suitability, cross-border human mobility, and region-specific COVID-19 susceptibility. The identification of these multiple drivers of the COVID-19 outbreak trajectory, based on mapping the spread of COVID-19, will contribute to a better understanding of the COVID-19 disease transmission risk and inform long-term preventative measures against this disease.

Application of modified cellular automata Markov chain model: forecasting land use pattern in Lebanon

This article modifies the use of the Cellular Automata Markov Chain Model to predict future land use pattern in Lebanon, and compares it to the current developed model. LandSat images of years 2000, 2009 and 2018 are used to generate land use maps within the geographic information system. Current developed model was generated by integrating Population density data with land use classification maps to decompose the built-up development to three sub-classes: High, Medium and Low-density built-up land uses. Simulations of future land use pattern over the year 2018 based on these two prediction models reveal that the Modified Cellular Automata Markov Chain Modelling technique is more accurate than the Extended Markov Chain model. Spatial effects of built-up densities are validated in this study. Consequently, the extension of the Cellular Automata Markov Chain Model represents an innovative tool for regional and urban planning to forecast potential locative distribution of old and new urban agglomeration. The sequential shift of the urban areas among different density classes in addition to the interactions of urban agglomerations should be employed as a guiding tool for decision-makers and planners during the phase of developing new population and economic strategies, new urban Masterplan and during the process of enacting/developing new land-use policies. In the final part of the study, a simulation of land use pattern for the year 2036 is generated using TerrSet v.18 software and an analysis of the outcome for the forecasted map is discussed.

Toward High-Performance Wideband GNSS Antennas-Design Tradeoffs and Development of Wideband Feed Network Structure

Many Global Positioning System (GPS) services have been recently introduced that extend over a wide frequency range from 1.16 to 1.61 GHz. For reception, either a wideband or multiband receiver is required, which is typically challenging to design as it requires a wideband feed network and a wideband circularly polarized antenna. Here, we investigate a high-performance Global Navigation Satellite Systems (GNSS) patch antenna fed by a wideband feed network to provide circular polarization (CP) over the whole bandwidth. The feed of the developed CP patch antenna requires 0°, 90°, 180°, and 270° sequential phase shift; an improved feed network with ±8° phase imbalance is designed to be used in the circularly polarized antenna. The manufactured antenna demonstrated a return loss better than 10 dB, axial ratio <; 1.7 dB, and RHCP gain >4.8 dB over the entire GNSS band. The developed antenna was connected to a GNSS receiver which tracked up to 28 satellites and the C/N0 of the received GNSS signals was better than 50 dB. Such a high-performance antenna design targets precise localization market.

Compact Heat Integrated Reactor System of Steam Reformer, Shift Reactor and Combustor for Hydrogen Production from Ethanol

A compact heat integrated reactor system (CHIRS) of a steam reformer, a water gas shift reactor, and a combustor were designed for stationary hydrogen production from ethanol. Different reactor integration concepts were firstly studied using Aspen Plus. The sequential steam reformer and shift reactor (SRSR) was considered as a conventional system. The efficiency of the SRSR could be improved by more than 12% by splitting water addition to the shift reactor (SRSR-WS). Two compact heat integrated reactor systems (CHIRS) were proposed and simulated by using COMSOL Multiphysics software. Although the overall efficiency of the CHIRS was quite a bit lower than the SRSR-WS, the compact systems were properly designed for portable use. CHIRS (I) design, combining the reactors in a radial direction, was large in reactor volume and provided poor temperature control. As a result, the ethanol steam reforming and water gas shift reactions were suppressed, leading to lower hydrogen selectivity. On the other hand, CHIRS (II) design, combining the process in a vertical direction, provided better temperature control. The reactions performed efficiently, resulting in higher hydrogen selectivity. Therefore, the high performance CHIRS (II) design is recommended as a suitable stationary system for hydrogen production from ethanol.

Circularly Polarized Planar Antenna Array Using Linear Polarized Microstrip Antenna with Beamforming for SAR Applications

Circular polarization is so important for satellite and SAR applications. Therefore, a relatively large planar array of 10 × 10 building blocks is proposed to get a high gain and to have the possibility of beamforming for such applications. The individual antenna element used in this array is a linear U-slotted microstrip patch. This allows for simplicity, lightweight and low cost. At first, a subarray of these microstrip antennas is constructed and analyzed to become a building block for the large array. This subarray is formed of four U-slotted microstrip antenna elements arranged in a cross form with 90° sequential rotation in orientation in space, and 90° sequential phase shift between adjacent microstrip elements. The distance between the centers of two opposite microstrip elements is selected to be 0.53λ0. A linear array is formed of ten of these subarrays and analyzed to become one row or one column in the final planar array. The distance between subarray centers is kept to be 0.53λ0, which implies a new arrangement technique using the superposition of elements of the adjacent subarrays. The phase and amplitude relations of this linear array are developed for beamforming using the particle swarm optimization algorithm. Finally, the planar array is formed and simulated. It also implies using the superposition theorem to get the final array form. This planar array has proved to produce a cosecant-squared radiation pattern in the φ = 0° plane normal to the array plane, and a flat-topped pattern in the other perpendicular plane of φ = 90°. This type of array is very suitable for SAR side looking applications.

VARIABILITY AND INTERRELATION OF THE BASIC CLIMATE INDICES FOR THE NORTH PACIFIC: TRENDS, CLIMATE SHIFTS, SPECTRA, CORRELATIONS

The study is continuing, which first results were published in 2019 [Khen et al., 2019]. The main patterns of long-term variability are considered for selected climate indices in the North Pacific and links between them are identified on the common methodological basis. The following indices are analyzed: AO (Arctic Oscillation), PDO (Pacific Decadal Oscillation), Nino 3.4 (index of El-Nino — South Oscillation), ALPI (Aleutian Low Pressure index), NPI (North Pacific index), PNA (Pacific/North American index), SHI (Siberian High index), and WP (West Pacific index). Their time-series are provided on websites of the world climate centers, with exception of the Siberian High index that was calculated from the reanalysis data on the sea level pressure provided by the USA National Center for Environmental Prediction (NCEP) — National Center for Atmospheric Research (NCAR) for 1950–2018. Data were analysed using standard statistical methods. Regime shifts are detected using Rodionov’s method of sequential regime shift detection including the regime shift index (RSI) and tools of automatic detection of the regime shifts with improved performance at the ends of time series. Variations of all indices since the middle 20th century correspond to warming that is not monotonous but combines phases of quick transition from one climatic regime to another — climate shifts and periods of relatively stable state between them. The most important climate shifts happened in 1977 and 1989 and they were noted for majority of the considered indices. Values of the indices heightened in the former shift and slightly lowered in the latter one, except of NPI that had opposite changes. PDO, WP and NPI had another positive shift in the recent years (2015–2017) that allows to assume transition to a new climate regime which will be warmer than the previous one in the last two decades. Long-term periodicity coincided with the 19-year cycle of lunar declination is revealed for PDO, ALPI, NPI and PNA; its spectral power amplifies considerably after removing of high-frequency variability by running 5-year averaging of the time series. Nino 3.4 showed a prominent 11-year cycle, possibly associated with the solar activity. SHI, AO and WP changed with periods about two decades: the main frequency is 26 years for SHI, 20 years for AO, and 17 years for WP, but the peaks of spectral power for the two latter indices is low, i.e. non-periodic oscillations dominate for them. Secondary peaks of spectral power are much lower than the main ones, they correspond to cycles of 7–8 years for AO and PDO, 11 years for WP, and 15 years for SHI. The indices of the North Pacific quartette (PDO, ALPI, NPI and PNA) are closely related between each other with high correlation coefficients (0.67–0.96). The Nino 3.4 index is also linked with them, but with lower correlation (0.45–0.56). SHI has statistically significant relationship with AO only, and WP correlates with Nino 3.4. Contribution of the large-scale climate processes to environmental variability in the Far-Eastern Seas of Russia and the Northwestern Pacific will be considered in the next issue.