Negative Phase Research Articles

Consequence of head-on collision of ion acoustic waves in unmagnetized plasmas having generalized (r, q) distributed electrons and positrons

To explore the effect of the head-on collision (such as phase shifts, collisional processes, and production of solitons) of ion-acoustic waves (IAWs), a collisionless unmagnetized electron-positron-ion (e-p-i) plasma is considered. The electrons and positrons follow the generalized () distribution. To do this, using the extended Poincaré-Lighthill-Kuo (ePLK) approach, the two-sided Korteweg-de Vries (KdV) equations and phase shifts are derived. The main aim of this study is to investigate the consequence of spectral indices and on both the negative and positive phase changes following an IAW-to-IAW collision. It is found that for the effects of the spectral indices of electrons and positrons both positive and negative phase shifts after head-on collisions are modified. The compressive (only hump-shaped) as well as rarefactive (both hump and dip-shaped) solitons become produced for the effect of spectral indices. The results obtained in the study may be helpful to understand the collision processes as well as the consequence of the head-on collision of IAWs in electron-positron-ion plasmas in the ionosphere, auroral acceleration regions, solar wind, Saturn rings, active galactic nuclei, polar cup of fast rotating neutron stars, semiconductor plasmas, and intense laser fields as well as in laboratory experiment.

Climate influence on compound solar and wind droughts in Australia

Solar photovoltaic and wind power are central to Australia’s renewable energy future, implying an energy sector vulnerable to weather and climate variability. Alignment of weather systems and the influence of large-scale climate modes of variability risks widespread reductions in solar and wind resources, and could induce grid-wide impacts. We therefore systematically analyse the relationship between compound solar radiation and wind speed droughts with weather systems and climate modes of variability over multiple time scales. We find that compound solar and wind droughts occur most frequently in winter, affecting at least five significant energy-producing regions simultaneously on 10% of days. The associated weather systems vary by season and by drought type, although widespread cloud cover and anticyclonic circulation patterns are common features. Indices of major climate modes are not strong predictors of grid-wide droughts, and are typically within one standard deviation of the mean during seasons with the most widespread events. However, the spatial imprints of the teleconnections display strong regional variations, with drought frequencies varying by more than ten days per season between positive and negative phases of climate modes in some regions. The spatial variability of these teleconnection patterns suggests that droughts in one region may be offset by increased resource in another. Our work highlights the opportunity for minimising the impact of energy production variability by utilising weather and climate intelligence. Exploiting the spatial variability associated with daily weather systems and the seasonal influence of climate modes could help build a more climate-resilient renewables-dominated energy system.

BIOM-40. THERABIOME-GBM: THERAPEUTIC OUTCOMES RELATED TO GUT MICROBIOME IN GLIOBLASTOMA (GBM) PATIENTS RECEIVING CHEMO-RADIATION: A PROSPECTIVE OBSERVATIONAL STUDY

Abstract PURPOSE A major barrier to improving outcomes in glioblastoma multiforme (GBM) is overcoming a heavily immunosuppressed tumor and systemic environment, as demonstrated by several negative phase III randomized studies of nivolumab in both newly diagnosed and recurrent GBM. In several mouse avatar and human studies across several tumor cohorts including in a humanized microbiome GBM model, re-establishing a new gut microbiome (GM) via fecal transplantation led to tumor responses to PD-1/PD-L1 inhibition. A recent scoping review confirmed a paucity of GM clinical data of a uniform GBM cohort with adequate longitudinal GM sample collection. We are conducting a single-center prospective observational study to establish the feasibility of collecting stool samples throughout the time course of GBM treatment and upon recurrence, and to understand the gut microbiome dynamics of newly diagnosed IDH-wild type (WT) GBM patients. METHODS Patients with newly diagnosed unifocal IDH-1 R132H WT WHO grade 4 GBM, ECOG 0-2, at least 70% tumor resected with plan to receive temozolomide-radiation (TMZ-RT) and adjuvant TMZ +/- Tumor Treating Fields are eligible. Stool samples will be collected prior to TMZ-RT, 4 weeks after TMZ-RT, after adjuvant TMZ, and upon recurrence. The primary endpoint is feasibility, defined as stool sample obtained pre-RT, post-RT (pre-adjuvant TMZ), and at time of recurrence in ≥ 70% of enrolled participants, 75% of target sample size enrolled within 2 years, and stool sample volume and quality sufficient for analysis in ≥ 75% of collected samples. Secondary endpoints include progression-free survival (PFS) in pre-defined GM subgroups, GM taxonomy and diversity in late vs. early progressors, and GM differences in patients with and without post-RT necrosis. Age, sex, race, concurrent medication, corticosteroid use, and diet will be carefully accounted for. Patient reported outcomes using EORTC-QLQ-BN20 and QLQ-C30 will be collected at baseline, 3-, 6-, 9-, and 12-months.

Dynamical linkages between Arctic Oscillations and winter precipitation patterns over the Indian Region

Winter precipitation over the Indian region is mainly beneficial for the maintenance of the glaciers in the mountainous region and associated atmospheric conditions benefit various sectors, including agriculture, water resources, power generation, and tourism, among others. Hence, understanding the variability and teleconnections of winter precipitation is indispensable. The present study focuses on the understanding of dynamical linkages between the Arctic Oscillations (AO) and winter precipitation variability over the Indian region using reanalysis and observational datasets. The analysis reveals the dipole pattern in the precipitation between the western Himalayas and the central Indian region, which is mainly linked with the positive (negative) phase of the AO. The positive (negative) phase of the AO is mainly associated to the Rossby wave with wavenumber 2 and dominated by the quasi-barotropic Euro-Atlantic and Siberian High (Ural-Siberian high and high over Northwest Pacific) which is accompanied by the wave train pattern across Europe through subtropical north Africa and west Asia. The wave train pattern abets the strengthening (weakening and southward movement) of the middle east jet stream and induces anticyclonic (cyclonic) circulation over the Arabian Sea in a positive (negative) regime of the AO. The precipitation dipole between the western Himalayan region and central India is primarily due to the moisture transport from an outflow of anticyclonic (cyclonic) circulation positioned over the north Arabian Sea which is allied with the positive (negative) phase of the AO and associated atmospheric dynamics.

Rapid appearance of negative emotion during oral fentanyl self-administration in male and female rats.

Opioid use disorder has become an epidemic in the United States, fuelled by the widespread availability of fentanyl, which produces rapid and intense euphoria followed by severe withdrawal and emotional distress. We developed a new preclinical model of fentanyl seeking in outbred male and female rats using volitional oral self-administration (SA) that can be readily applied in labs without intravascular access. Using a traditional two-lever operant procedure, rats learned to take oral fentanyl vigorously, escalated intake across sessions, and readily reinstated responding to conditioned cues after extinction. Oral SA also revealed individual and sex differences that are essential to studying substance use risk propensity. During a behavioural economics task, rats displayed inelastic demand curves and maintained stable intake across a wide range of fentanyl concentrations. Oral SA was also neatly patterned, with distinct 'loading' and 'maintenance' phases of responding within each session. Using our software DeepSqueak, we analysed ultrasonic vocalizations (USVs), which are innate expressions of current emotional state in rats. Rats produced 50 kHz USVs during loading then shifted quickly to 22 kHz calls despite ongoing maintenance of oral fentanyl taking, reflecting a transition to negative reinforcement. Using fibre photometry, we found that the lateral habenula differentially processed drug cues and drug consumption depending on affective state, with potentiated modulation by drug cues and consumption during the negative affective maintenance phase. Together, these results indicate a rapid progression from positive to negative reinforcement occurs even within an active drug taking session, revealing a within-session opponent process.

Potential causes of megapluvials in the Yangtze–Huaihe River valley over the last millennium

The potential causes of megapluvials over Yangtze–Huaihe River valley (YHRV) during the last millennium were investigated using the Community Earth System Model-Last Millennium Ensemble (CESM-LME) simulation data and multiple proxy data (i.e., reconstruction and paleoclimate assimilation data). Herein, we first depicted the spatial hydroclimatic pattern over the Northern Hemisphere when megapluvials occurred in the YHRV during the last millennium. The proxy and simulation data both showed that megapluvials in YHRV were accompanied by extensive decadal drought in western Asia and northwestern India, also located in mid to low latitudes. Then, by diagnosing the dynamic processes, we found that the baroclinic structure over western Asia and northwestern India caused anomalous geopotential heights, and hence triggered the negative phase of the Circumglobal Teleconnection (CGT). The eastwards wave train at mid-latitudes disturbed by the CGT mode, triggered lower-level northerlies and upper-level southerlies over the northern part of the YHRV and, as a consequence, led to anomalous strong convection near the YHRV. Together with abundant water vapour from the Pacific Northwest, there was a synergistic effect on megapluvial events over the YHRV. Finally, we analysed the linkage of surface temperature in western Asia and northwestern India and megapluvials in the YHRV. Land surface heating over western Asia and northwestern India may largely stimulate the formation of a negative CGT mode through local feedback of air–land interactions and, as a result, affect precipitation anomalies downstream, such as in the YHRV. It is therefore necessary to consider anomalous high surface temperatures in western Asia and northwestern India as important predictors for interdecadal severe floods in the YHRV.

Marine heatwaves intensification, expansion and departure into the permanent state over the Tropical Indian Ocean: A regional earth system model assessment

This study employed a regional earth system model, namely ROM over the CORDEX-SA domain, to investigate the future changes in the Marine heatwaves (MHWs) with respect to the historical baseline period (1976–2005) in the three time-slices, explicitly, near future (NRF; 2010–2039), middle future (MDF;2040–2069), and far future (FRF; 2070–2099) under two emission scenarios, Representative Concentration Pathway (RCP4.5 and RCP8.5). For the historical period, ROM showed a reasonable agreement with observed MHWs metrics and their trends and outperformed the forcing General Circulation Model and Multi-Model Ensemble of CMIP5 models. The future MHWs are expected to increase in intensity and duration. The continuous lengthening of MHWs duration leads to a permanent MHW state condition with strong spatial variability in its appearance. The first permanent MHW will emerge in both RCPs, while the absolute permanent MHW state is mainly visible in RCP8.5. The genesis and augmentation in the MHWs intensity is associated with local air-sea fluxes, however, in the long term, the increase in the mean SST in the future led to the rise of MHWs activity. The diagnosis of El Niño Southern Oscillation teleconnection and Indian Ocean Dipole on the MHWs is investigated. During the El Niño regime, not only did the proportion of the Tropical Indian Ocean experiencing MHWs increase but also an increase in the intensity is evident. IOD controls the MHWs metrics in the proximity of the western box and eastern box during its positive and negative phases.

PSVI-25 A Phytogenic Additive Improves Immune Responses of Growing Beef Cattle on Grazing System

Abstract Our objective was to evaluate the effect of a phytogenic additive in protein supplement for grazing Nellore young bulls on serum protein profile. One hundred and fourteen animals (iBW, n = 114; 273 ± 4.46 kg) were allocated for 152 days in six pastures of Brachiaria brizantha cv. Marandu (̴7 ha each), and randomly distributed in six treatments with or without additives on protein supplement (30% crude protein). Treatments were: 1) Negative Control (CON), with no additive; 2) Positive Control, with 15 ppm of Monensin (MON); 3) Digestarom (DSM Nutritional Products) at 0.2 g· animal-1· /day-1 (D0.2); 4) Digestarom at 0.4 g· animal-1· /day-1 (D0.4); 5) Digestarom at 0.6 g· animal-1· /day-1 (D0.6) and 6) Digestarom at 0.8 g· animal-1· /day-1 (D0.8). Supplement was offered ad libitum. Additives dosages were adjusted weekly to achieve the targeted dose/animal. Blood samples were collected in the last day and analyzed for positive acute phase proteins (increases with the inflammation response), haptoglobin (HAP) and glycoprotein (GLY); negative acute phase protein (decreases with the inflammation), transferrin (TRA); and Immunoglobulins A and G. Data were analyzed using SAS PROC GLIMMIX. Significance of 5% was adopted. Contrasts of use of Monensin, use of Digestarom, type of additive, and linear and quadratic effects of Digestarom were evaluated. Compared with MON, Digestarom decreased (P < 0.05) HAP (124 vs. 76.2 mg/dL) and GLY (1,361 vs. 85.6 mg/dL). TRA increased (P < 0.05) with Digestarom (310 and 307 mg/dL for D0.6 and D0.8, vs. 204 and 177 mg/dL for CON and MON). Digestarom increased (P < 0.05) immunoglobulins A (193, 218 and 225 mg/dL for D0.4, D0.6 and D0.8) and G (1.5 g/dL for D0.4, D0.6 and D0.8) compared with CON (IgA 146 mg/dL and IgG 0.9 g/dL) and MON (IgA 93 mg/dL and IgG 0.3 g/dL). Digestarom levels also showed a quadratic effect on TRA (including 165 and 245 mg/dL for D0.2 and D0.4) and on IgA and IgG (including 124 mg/dL and 0.8 g/dL for D0.2). Overall serum protein responses of the animals receiving Digestarom (reduced haptoglobin and glycoprotein, and graeter transferrin, IgA and IgG) demonstrates that these animals had improved immune responses and could be better able to respond to infectious and stress challenges.

Bubble cloud characteristics and ablation efficiency in dual-frequency intrinsic threshold histotripsy

Histotripsy is a non-thermal focused ultrasound ablation method that destroys tissue through the generation and activity of acoustic cavitation bubble clouds. Intrinsic threshold histotripsy uses single-cycle pulses to generate bubble clouds when the dominant negative pressure phase exceeds an intrinsic threshold of ∼25–30 MPa. The ablation efficiency is dependent upon the size and density of bubbles within the bubble cloud. This work investigates the effects of dual-frequency pulsing schemes on the bubble cloud behavior and ablation efficiency in intrinsic threshold histotripsy. A modular 500 kHz:3 MHz histotripsy transducer treated agarose phantoms using dual-frequency histotripsy pulses with a 1:1 pressure ratio from 500 kHz and 3 MHz frequency elements and varying arrival times for the 3 MHz pulse relative to the arrival of the 500 kHz pulse (−100 ns, 0 ns, and +100 ns). High-speed optical imaging captured cavitation effects to characterize bubble cloud and individual bubble dynamics. The effects of dual-frequency pulsing on lesion formation and ablation efficiency were also investigated in red blood cell (RBC) phantoms. Results showed that the single bubble and bubble cloud size for dual-frequency cases were intermediate to published results for the component single-frequencies of 500 kHz and 3 MHz. Additionally, bubble cloud size and dynamics were shown to be altered by the arrival time of the 3 MHz pulse with respect to the 500 kHz pulse, with more uniform cloud expansion and collapse observed for early (−100 ns) arrival. Finally, RBC phantom experiments showed that dual-frequency exposures were capable of generating precise lesions with smaller areas and higher ablation efficiencies than previously published results for 500 kHz or 3 MHz. Overall, results demonstrate dual-frequency histotripsy’s ability to modulate bubble cloud size and dynamics can be leveraged to produce precise lesions at higher ablation efficiencies than previously observed for single-frequency pulsing.

In Phase 2 and Phase 3 Trials, Broadening the Definition of Acute Vaso-Occlusive Pain to Include at Least One Episode of Pain Requiring Nsaids, Opioids, or Both Treatments at Home within 30 Days of a Physician Visit

Introduction:Despite the high incidence of acute painful events in children and adults with SCD, there is a lack of consensus on the acute pain definition in controlled clinical trials. To address this limitation, we elected to have three definitions of acute vaso-occlusive pain based on the setting for the pain location: inpatient, outpatient, ED, or at home. Based on the results of the SPRING Trial, the primary stroke prevention trial in children with SCD conducted in Nigeria (The Lancet Haematol. 2022 Jan 1;9(1):e26-37), and the PISCES study (Annals of internal medicine. 2008 Jan 15;148(2):94-101), most acute pain events in low-middle and high-income countries occur at home. We tested the hypothesis that the majority of negative phase 2 and phase 3-controlled trials for SCD failed to consider acute pain events in all four settings. Methods: To identify the relevant Phase II and III trials with acute pain as an outcome, we conducted a literature review using the website clinicaltrials.gov with the following key terms: “Sickle Cell Disease,” and “Vaso-occlusive.”. Studies that were not Phase II or Phase III were excluded from our search. We identified Phase 2 or 3 SCD pain trials published between 2015 and 2023. Inclusion criteria: definitions in the clinicaltrials.gov trial page, protocol, or method section. An inclusive, consensus definition for vaso-occlusive pain was chosen from the SPRING Trial. This definition was compared to the acute vaso-occlusive pain definitions of both SCD Phase 2 and 3 trials, with vaso-occlusive pain as a primary or secondary outcome. Based on the SPRING Trial and the results of the PISCES study, we elected to have three definitions of acute vaso-occlusive pain: 1. inpatient uncomplicated pain that excludes a concomitant diagnosis of acute chest syndrome; 2. Pain that required either an inpatient or outpatient visit and opioid treatment; and 3. An acute pain event at home requiring NSAIDs, opioids, or both. Only uncomplicated pain events were included to avoid double counting participants who developed acute chest syndrome or strokes that may have preceded the vaso-occlusive pain event. Results: We identified 35 articles based on our criteria. Our study sample included 3 clinical trials that led to the FDA approval for therapy to prevent acute vaso-occlusive pain events (FDA-approved therapy trials). Among these 35 trials, 32 clinical trials did not provide any evidence of the therapeutic benefits of the experimental agent (negative controlled trials). The three randomized controlled trials that led to FDA approval for therapy to prevent acute pain were: Hydroxyurea, L-Glutamine, and Crizanlizumab. Hospitalization for pain was included in all three FDA-approved therapy trials and 34.4% (11/32) of negative controlled trials. The ED visits in the pain definition were included in all 3 FDA-approved therapy trials and 28.1% (9/32) of negative controlled trials. Outpatient visits in the pain definition were included in all 3 FDA-approved therapy trials and 21.9% (7/32) of negative controlled trials. Home pain episodes were included in none of the FDA-approved therapy trials and 9.4% (3/32) of negative controlled trials. Finally, 43.8% (14/32) negative controlled trials were excluded as they failed to define vaso-occlusive pain in their methods or definition section and 15.6% (5/32) negative controlled trials did not have a publication. Conclusion: Most controlled trials designed to evaluate the efficacy of new treatment did not include the setting where pain occurs most frequently, at home. For future therapeutic trials designed to address whether a new therapy decreases the incidence rate of acute pain, we recommend an assessment of pain in all 4 four settings (Hospitalization, ED, Outpatient, and Home).

Variability of Arctic Sea ice age and its relationship with atmospheric circulation patterns

Since at least the 1990s, global warming has caused the decline of multi-year ice (MYI) in the Arctic, which has made the Arctic Ocean more susceptible to the effects of climate change and weather processes. In this study, an analysis of the variations in Arctic sea ice age was carried out based on the results of an Empirical Orthogonal Function (EOF) analysis. Variations in three time periods were investigated. The first period (1984-1995) is characterized by high sea ice age, with antiphase variation processes in the eastern and western parts of the Arctic Ocean. The second period (1996-2012) represents a rapid reduction in ice age, characterized by a gradual replacement of MYI in the Arctic Ocean with seasonal sea ice, resulting in a decreased extent of MYI. The third period (2013-2022) is characterized by low sea ice age, with ice age being in a significantly negative phase. Furthermore, trend-like changes were weak during this period. During the first period, the spatial distribution and significant variations in ice age were driven by cyclonic wind anomalies associated with the Arctic Oscillation (AO) atmospheric pressure modes. The cyclonic wind fields in winter and anticyclonic wind fields in summer collectively influenced the sea ice. This led to a decrease/increase in ice age in the eastern/western Arctic, and antiphase variations were apparent. During the second study period, winter ice age variations were driven by cyclonic wind anomalies associated with the AO atmospheric pressure modes, leading to ice divergence and a decrease in ice age. In summer, both thermodynamic (Arctic warming) and dynamic (DA) mechanisms play a role in modulating the changes of sea ice age, while Arctic warming is the primary driver. The DA generated anomalous wind patterns, characterized by the Beaufort Gyre and Transpolar Drift, which resulted in the outflow of MYI from the Arctic under the influence of meridional winds. During the third study period, the influence of AO/DA and air temperature on sea ice age changes is greatly weakened.

Relative and Absolute Sea Level Change Variability in The Palabuhanratu Bay Waters

SLR could affect the waters of Palabuhanratu Bay, which are exposed to the Indian Ocean. Sea levels are rising due to RSL and ASL changes. RSL has increased by 22.86 mm/year based on tidal data for 2013–2022. In contrast, ASL has increased by 4.48 mm/year based on satellite altimetry data for 1992–2022. The research uses the linear regression method to get the SLR value. According to earlier studies, dynamic change elements connected to alterations in the atmosphere and ocean circulation are typically considered when analyzing sea level variations. This work explores sea-level variations, including dynamic and static changes impacted by geological processes like deformation. Dynamic change factors, such as climate anomalies, ENSO, and IOD, affect these changes. Regarding RSL changes, ENSO has a more decisive influence than IOD, and vice versa for ASL changes. In the La Nina phenomenon and negative IOD phase, RSL and ASL trend changes are enhanced, whereas they are lowered in the El Nino and positive IOD phases. These waters’ sea-level variations are only slightly impacted by local processes, such as VLM. It has a more decisive influence on RSL changes than ASL.

Alpha transcranial alternating current stimulation modulates auditory perception

BackgroundStudies using transcranial alternating current stimulation (tACS), a type of non-invasive brain stimulation, have demonstrated a relationship between the positive versus negative phase of both alpha and delta/theta oscillations with variable near-threshold auditory perception. These findings have not been directly compared before. Furthermore, as perception was better in the positive versus negative phase of two different frequencies, it is unclear whether changes in polarity (independent of a specific frequency) could also modulate auditory perception. ObjectiveWe investigated whether auditory perception depends on the phase of alpha, delta/theta, or polarity alone. MethodsWe stimulated participants with alpha, delta, and positive and negative direct current (DC) over temporal and central scalp sites while they identified near-threshold tones-in-noise. A Sham condition without tACS served as a control condition. A repeated-measures analysis of variance was used to assess differences in proportions of hits between conditions and polarities. Permutation-based circular-logistic regressions were used to assess the relationship between circular-predictors and single-trial behavioral responses. An exploratory analysis compared the full circular-logistic regression model to the intercept-only model. ResultsOverall, there were a greater proportion of hits in the Alpha condition in comparison to Delta, DC, and Sham conditions. We also found an interaction between polarity and stimulation condition; post-hoc analyses revealed a greater proportion of hits in the positive versus negative phase of Alpha tACS. In contrast, no significant differences were found in the Delta, DC, or Sham conditions. The permutation-based circular-logistic regressions did not reveal a statistically significant difference between the obtained RMS of the sine and cosine coefficients and the mean of the surrogate distribution for any of the conditions. However, our exploratory analysis revealed that circular-predictors explained the behavioral data significantly better than an intercept-only model for the Alpha condition, and not the other three conditions. ConclusionThese findings suggest that alpha tACS, and not delta nor polarity alone, modulates auditory perception.

ОТКЛИК ТЕМПЕРАТУРЫ ВОЗДУХА НА ПОВТОРЯЕМОСТЬ БЛОКИРОВАНИЯ В АТЛАНТИКО-ЕВРОАЗИАТСКОМ СЕКТОРЕ В ОСЕННЕ-ЗИМНИЙ ПЕРИОД

The changes in the response of air temperature to the variations in the instantaneous blocking frequency (IBF) (GHGS > 0) between the periods 1979-1999 and 2000-2020 are studied. Blocking patterns, which are the spatial distributions of the coefficients of correlation between the IBF and the 1000 hPa temperature field, are used as the main characteristic. The blocking frequency is calculated in ten longitudinal sectors in the eastern direction from the west of the North Atlantic region to the eastern borders of Siberia and the Pacific Ocean. It is found that blocking patterns moved northward over the Atlantic region (November, December, and February), the Ural region and Siberia (November, January, and February) in 2000-2020. In addition, they were characterized by more pronounced areas of negative correlations over Eurasia and North America as compared to 1979-1999. Along with the pronounced correlation pattern of the Atlantic region, the patterns of the Ural region and Western Siberia (U-WS) proved to be the most significant. It is assumed that the IBF variability over the U-WS sector is an important indicator of the development of the most significant blocking processes over Eurasia in terms of the temperature regime anomalies. The influence of U-WS blockings was the least noticeable in 2000-2020 for December and in 1979-1999 for January, when the response of the temperature field to the blocking changes was similar to the response of the negative phase of the North Atlantic Oscillation.

Изучение принципов построения широкополосной колебательной СВЧ системы на примере резонатора Фабри-Перо

In telecommunications and radar systems of the centimeter and millimeter wave ranges, span klystrons are widely used as medium and high power amplifiers. The use of high-quality resonators makes it possible to realize high efficiency and amplification factors. However, typical designs of 2 - 4 resonator klystrons have a bandwidth of 0.1 - 0.5 % due to the need to use resonators with a high Q – factor. The well-known method of expanding the amplified frequency band in the centimeter range up to 7 – 12 % and in the millimeter range up to 1 - 2 % consists in tuning the frequency of the intermediate klystron resonators by several percent of the central amplification frequency. But in this case, it is required to use 10 - 12 resonators. The authors of the work discovered that when a millimeter range electromagnetic wave is reflected from an electrodynamics system in the form of a metal film on the surface of a semiconductor layer, the input resistance phase-frequency characteristic of this system consists of a chain of frequency intervals with turnings from a positive phase-frequency characteristic to a negative one and vice versa. The possibility of constructing a phase shifter with a negative phase frequency response based on this phenomenon is demonstrated and its application for expanding the resonant frequency band is considered on the example of the Fabry - Perot interferometer model. This resonator contains a phase shifter in the form of a semiconductor layer F with a thickness DF, a conductivity σF, a relative dielectric eF and a magnetic mF permeability. The outer surface of the layer F contains a metal mirror, and the inner surface is adjacent to the layer W. The layer W which has the thickness of DW, eW, mW forms the internal space of the resonator. The external environment I with mI and eI. adjoins the layer W. A plane electromagnetic wave propagates in I media so that it excites the resonator at a wavelength of l0. The use of a phase shifter makes it possible to increase the resonant wavelength band Δl/l0 by 2 - 4 times and with an electromagnetic field amplification coefficient |G(l)| in the W layer by 10 - 20 times (the value of Dl/l0 corresponds to 0.707 max |G(l0)|). An increase of σF leads to an amplitude-frequency characteristic transforming of the field gain function G(l0) from two maxima to one maximum form with a transition through a flat top. In this case max |G(l0)| decreases and Dl/l0 increases. For the case, when the function |G(l)| has a flat top, an increase in the wave resistance ρW of the layer W with a corresponding decrease in sF and optimal values of DW leads to an increase in |G(l0)|. When this occurs, Dl/l0 becomes lower.

Stimulus-Induced Theta-Band LFP Oscillations Format Neuronal Representations of Social Chemosignals in the Mouse Accessory Olfactory Bulb.

Social communication is crucial for the survival of many species. In most vertebrates, a dedicated chemosensory system, the vomeronasal system (VNS), evolved to process ethologically relevant chemosensory cues. The first central processing stage of the VNS is the accessory olfactory bulb (AOB), which sends information to downstream brain regions via AOB mitral cells (AMCs). Recent studies provided important insights about the functional properties of AMCs, but little is known about the principles that govern their coordinated activity. Here, we recorded local field potentials (LFPs) and single-unit activity in the AOB of adult male and female mice during presentation of natural stimuli. Our recordings reveal prominent LFP theta-band oscillatory episodes with a characteristic spatial pattern across the AOB. Throughout an experiment, the AOB network shows varying degrees of similarity to this pattern, in a manner that depends on the sensory stimulus. Analysis of LFP signal polarity and single-unit activity indicates that oscillatory episodes are generated locally within the AOB, likely representing a reciprocal interaction between AMCs and granule cells. Notably, spike times of many AMCs are constrained to the negative LFP oscillation phase in a manner that can drastically affect integration by downstream processing stages. Based on these observations, we propose that LFP oscillations may gate, bind, and organize outgoing signals from individual AOB neurons to downstream processing stages. Our findings suggest that, as in other neuronal systems and brain regions, population-level oscillations play a key role in organizing and enhancing transmission of socially relevant chemosensory information.SIGNIFICANCE STATEMENT The accessory olfactory bulb (AOB) is the first central stage of the vomeronasal system, a chemosensory system dedicated to processing cues from other organisms. Information from the AOB is conveyed to other brain regions via activity of its principal neurons, AOB mitral cells (AMCs). Here, we show that socially relevant sensory stimulation of the mouse vomeronasal system leads not only to changes in AMC activity, but also to distinct theta-band (∼5 Hz) oscillatory episodes in the local field potential. Notably AMCs favor the negative phase of these oscillatory events. Our findings suggest a novel mechanism for the temporal coordination of distributed patterns of neuronal activity, which can serve to efficiently activate downstream processing stages.

Relationship between the Silk Road and Circumglobal Teleconnection Patterns on the Interannual and Interdecadal Timescales

The Silk Road pattern (SRP) and circumglobal teleconnection pattern (CGT) are two well-known teleconnection patterns, representing the summer circulation variations of the Northern Hemisphere mid-latitudes, which have different definitions but are often regarded as one teleconnection pattern. In view of the distinct features of the SRP/CGT on the interannual (IA) and interdecadal (ID) timescales, the present study investigates the linkages and differences between the SRP and CGT on the two timescales, respectively. On the IA timescale, both the SRP and CGT feature a similar circumglobal wave train structure with strong and significant centers over Eurasia but show clear independence. Specifically, the SRP and CGT illustrate largely the mid-/high-latitude-related and tropics-related parts of the Northern Hemisphere upper tropospheric circulation variations, respectively. Also, the CGT shows a stronger connection to the Indian summer monsoon (ISM) heating and El Niño–Southern Oscillation than the SRP, which makes the CGT more like a tropical forcing-driven atmospheric mode and the SRP more like an internal atmospheric mode. The linkages and differences between them are associated with their asymmetrical relationship during their positive and negative phases, which are attributed mainly to the asymmetrical impact of the ISM heating/cooling on the Eurasian circulations. On the ID timescale, the SRP and CGT are characterized by a coherent two-wave train structure over Eurasia and feature a similar teleconnection pattern over Eurasia, which is associated with the Pacific Decadal Oscillation and Atlantic Multidecadal Oscillation. The present findings on their linkages and differences are helpful in understanding the variability and prediction of the SRP and CGT.

Late Pleistocene–Holocene multi-decadal patterns of extreme floods in NW Iberia: The Duero River palaeoflood record

Extreme floods are anticipated to become more frequent in a future warmer climate. However, the long-term alterations in flood patterns across different regions of Europe remain unclear. In this study, we present a 15,000-year record of extreme floods in the Duero River, located in the southwestern Atlantic region. We analysed slackwater flood sediments, quantified the discharge and timing of individual flood beds over millennial time scales, and identified their potential climate influences. The composite record includes at least 62 floods grouped into ten flood-rich periods (with an average duration of 230 years). A high-frequency phase of moderate-magnitude floods (>10 events) occurred at ∼11.6–11.5 ka, following a period of reduced flood activity during the Younger Dryas. Similar clusters of Early Holocene floods (10.8–10.3 ka, 9.5 ka) coincided with or preceded meltwater pulses from the North Atlantic. The absence of palaeoflood records with discharges exceeding 6100 m3/s during the Mid-Holocene suggests a decline in winter hydro-meteorological extremes. High flood magnitudes were recorded during transition periods toward cooler and wetter conditions at 4.4, 2.3, 0.5, and 0.11 ka with discharges ranging from 7600 to 10,000 m3/s. These periods were interpreted as indicative of a southward shift in cyclone tracks in Europe driven by negative phases of the North Atlantic Oscillation (NAO). Conversely, flood magnitudes decreased during past warmer climate conditions (1.7 ka, 0.9 ka, and the present), although flood frequency remained high. The current decline in flood frequency reflects an increase in flood regulation due to dams, but it is also consistent with the prevailing positive trend in the NAO observed over the last 40 years.

Extracorporeal Shock Wave Therapy for the Treatment of Musculoskeletal Pain: A Narrative Review.

Extracorporeal shock waves have been used for pain treatment for various sub-acute and chronic musculoskeletal (MSK) problems since 2000. The aim of this article is to update information on the role of extracorporeal shock wave therapy (ESWT) in the treatment of various pathologies that cause MSK pain. Given that in the last two years, articles of interest (including systematic reviews and meta-analyses) have been published on less known indications, such as low back pain, nerve entrapments, osteoarthritis and bone vascular diseases, a literature search was conducted in PubMed, the Cochrane Database, EMBASE, CINAHL and PEDro, with the aim of developing a narrative review of the current literature on this topic. The purposes of the review were to review possible new mechanisms of action, update the level of evidence for known indications and assess possible new indications that have emerged in recent years. Although extracorporeal shock waves have mechanical effects, their main mechanism of action is biological, through a phenomenon called mechanotransduction. There is solid evidence that supports their use to improve pain in many MSK pathologies, such as different tendinopathies (epicondylar, trochanteric, patellar, Achilles or calcific shoulder), plantar fasciitis, axial pain (myofascial, lumbar or coccygodynia), osteoarthritis and bone lesions (delayed union, osteonecrosis of the femoral head, Kienbock's disease, bone marrow edema syndrome of the hip, pubis osteitis or carpal tunnel syndrome). Of the clinical indications mentioned in this review, five have a level of evidence of 1+, eight have a level of evidence of 1-, one indication has a level of evidence of 2- and two indications have a level of evidence of 3. The current literature shows that ESWT is a safe treatment, with hardly any adverse effects reported. Furthermore, it can be used alone or in conjunction with other physical therapies such as eccentric strengthening exercises or static stretching, which can enhance its therapeutic effect.

The 10‐ to 30‐Day Intraseasonal Weather Process Associated With Wintertime PM2.5 Pollution in Eastern China

AbstractSevere PM2.5 pollution strikes winter eastern China, while its physical process associated with the atmospheric evolution from several days to weeks is not clear. This study uses weather types as intermediate agents between large‐scale atmospheric circulation and regional air pollution, to explore the whole circulation evolutionary chain related to wintertime PM2.5 pollution in eastern China. We extract objectively 6 weather types (WTs) for wintertime surface synoptic patterns in eastern China and analyze quantitatively the impacts of WTs on PM2.5 pollution. Then the preferred transitions between WTs are explored to explain potential weather process. We find a most frequently recurring circulation evolution corresponding to Mongolia high pressure that stretches southward to eastern China, referred as the WTs transition of YSH− > BLH− > MH, with PM2.5 increased in North China and dissipated as the high pressure moves southward. Further to establish intraseasonal connections between large‐scale circulation and regional synoptic patterns, several leading evolutionary chains are discovered among tropical Madden‐Julian Oscillation (MJO), extratropical teleconnections, and WTs of eastern China at an extended period. The positive or negative phase of teleconnections can indicate the WTs change 4–10 days in advance, while MJO further extends that indicative effect to 10–15 days. The intraseasonal oscillations of teleconnections such as conventional Eurasia, Scandinavia, Arctic Oscillation, Polar/Eurasia, Western Pacific and East Atlantic are associated with the transition of YSH− > BLH− > MH, and MJO may act as a precursor of teleconnection phases to extend effectively the prediction time for surface weather conditions and air pollution in eastern China.